1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __ASM_PREEMPT_H #define __ASM_PREEMPT_H #include <asm/rmwcc.h> #include <asm/percpu.h> #include <linux/thread_info.h> DECLARE_PER_CPU(int, __preempt_count); /* We use the MSB mostly because its available */ #define PREEMPT_NEED_RESCHED 0x80000000 /* * We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such * that a decrement hitting 0 means we can and should reschedule. */ #define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED) /* * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users * that think a non-zero value indicates we cannot preempt. */ static __always_inline int preempt_count(void) { return raw_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED; } static __always_inline void preempt_count_set(int pc) { int old, new; do { old = raw_cpu_read_4(__preempt_count); new = (old & PREEMPT_NEED_RESCHED) | (pc & ~PREEMPT_NEED_RESCHED); } while (raw_cpu_cmpxchg_4(__preempt_count, old, new) != old); } /* * must be macros to avoid header recursion hell */ #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ per_cpu(__preempt_count, (cpu)) = PREEMPT_DISABLED; \ } while (0) /* * We fold the NEED_RESCHED bit into the preempt count such that * preempt_enable() can decrement and test for needing to reschedule with a * single instruction. * * We invert the actual bit, so that when the decrement hits 0 we know we both * need to resched (the bit is cleared) and can resched (no preempt count). */ static __always_inline void set_preempt_need_resched(void) { raw_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED); } static __always_inline void clear_preempt_need_resched(void) { raw_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED); } static __always_inline bool test_preempt_need_resched(void) { return !(raw_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED); } /* * The various preempt_count add/sub methods */ static __always_inline void __preempt_count_add(int val) { raw_cpu_add_4(__preempt_count, val); } static __always_inline void __preempt_count_sub(int val) { raw_cpu_add_4(__preempt_count, -val); } /* * Because we keep PREEMPT_NEED_RESCHED set when we do _not_ need to reschedule * a decrement which hits zero means we have no preempt_count and should * reschedule. */ static __always_inline bool __preempt_count_dec_and_test(void) { return GEN_UNARY_RMWcc("decl", __preempt_count, e, __percpu_arg([var])); } /* * Returns true when we need to resched and can (barring IRQ state). */ static __always_inline bool should_resched(int preempt_offset) { return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset); } #ifdef CONFIG_PREEMPTION extern asmlinkage void preempt_schedule_thunk(void); # define __preempt_schedule() \ asm volatile ("call preempt_schedule_thunk" : ASM_CALL_CONSTRAINT) extern asmlinkage void preempt_schedule(void); extern asmlinkage void preempt_schedule_notrace_thunk(void); # define __preempt_schedule_notrace() \ asm volatile ("call preempt_schedule_notrace_thunk" : ASM_CALL_CONSTRAINT) extern asmlinkage void preempt_schedule_notrace(void); #endif #endif /* __ASM_PREEMPT_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_BLOCKGROUP_LOCK_H #define _LINUX_BLOCKGROUP_LOCK_H /* * Per-blockgroup locking for ext2 and ext3. * * Simple hashed spinlocking. */ #include <linux/spinlock.h> #include <linux/cache.h> #ifdef CONFIG_SMP #define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32)) #else #define NR_BG_LOCKS 1 #endif struct bgl_lock { spinlock_t lock; } ____cacheline_aligned_in_smp; struct blockgroup_lock { struct bgl_lock locks[NR_BG_LOCKS]; }; static inline void bgl_lock_init(struct blockgroup_lock *bgl) { int i; for (i = 0; i < NR_BG_LOCKS; i++) spin_lock_init(&bgl->locks[i].lock); } static inline spinlock_t * bgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group) { return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock; } #endif
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 /* SPDX-License-Identifier: GPL-2.0 */ #include <linux/fs.h> #include <linux/buffer_head.h> #include <linux/exportfs.h> #include <linux/iso_fs.h> #include <asm/unaligned.h> enum isofs_file_format { isofs_file_normal = 0, isofs_file_sparse = 1, isofs_file_compressed = 2, }; /* * iso fs inode data in memory */ struct iso_inode_info { unsigned long i_iget5_block; unsigned long i_iget5_offset; unsigned int i_first_extent; unsigned char i_file_format; unsigned char i_format_parm[3]; unsigned long i_next_section_block; unsigned long i_next_section_offset; off_t i_section_size; struct inode vfs_inode; }; /* * iso9660 super-block data in memory */ struct isofs_sb_info { unsigned long s_ninodes; unsigned long s_nzones; unsigned long s_firstdatazone; unsigned long s_log_zone_size; unsigned long s_max_size; int s_rock_offset; /* offset of SUSP fields within SU area */ s32 s_sbsector; unsigned char s_joliet_level; unsigned char s_mapping; unsigned char s_check; unsigned char s_session; unsigned int s_high_sierra:1; unsigned int s_rock:2; unsigned int s_cruft:1; /* Broken disks with high byte of length * containing junk */ unsigned int s_nocompress:1; unsigned int s_hide:1; unsigned int s_showassoc:1; unsigned int s_overriderockperm:1; unsigned int s_uid_set:1; unsigned int s_gid_set:1; umode_t s_fmode; umode_t s_dmode; kgid_t s_gid; kuid_t s_uid; struct nls_table *s_nls_iocharset; /* Native language support table */ }; #define ISOFS_INVALID_MODE ((umode_t) -1) static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb) { return sb->s_fs_info; } static inline struct iso_inode_info *ISOFS_I(struct inode *inode) { return container_of(inode, struct iso_inode_info, vfs_inode); } static inline int isonum_711(u8 *p) { return *p; } static inline int isonum_712(s8 *p) { return *p; } static inline unsigned int isonum_721(u8 *p) { return get_unaligned_le16(p); } static inline unsigned int isonum_722(u8 *p) { return get_unaligned_be16(p); } static inline unsigned int isonum_723(u8 *p) { /* Ignore bigendian datum due to broken mastering programs */ return get_unaligned_le16(p); } static inline unsigned int isonum_731(u8 *p) { return get_unaligned_le32(p); } static inline unsigned int isonum_732(u8 *p) { return get_unaligned_be32(p); } static inline unsigned int isonum_733(u8 *p) { /* Ignore bigendian datum due to broken mastering programs */ return get_unaligned_le32(p); } extern int iso_date(u8 *, int); struct inode; /* To make gcc happy */ extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated); extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *); extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *); int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *); int get_acorn_filename(struct iso_directory_record *, char *, struct inode *); extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags); extern struct buffer_head *isofs_bread(struct inode *, sector_t); extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long); struct inode *__isofs_iget(struct super_block *sb, unsigned long block, unsigned long offset, int relocated); static inline struct inode *isofs_iget(struct super_block *sb, unsigned long block, unsigned long offset) { return __isofs_iget(sb, block, offset, 0); } static inline struct inode *isofs_iget_reloc(struct super_block *sb, unsigned long block, unsigned long offset) { return __isofs_iget(sb, block, offset, 1); } /* Because the inode number is no longer relevant to finding the * underlying meta-data for an inode, we are free to choose a more * convenient 32-bit number as the inode number. The inode numbering * scheme was recommended by Sergey Vlasov and Eric Lammerts. */ static inline unsigned long isofs_get_ino(unsigned long block, unsigned long offset, unsigned long bufbits) { return (block << (bufbits - 5)) | (offset >> 5); } /* Every directory can have many redundant directory entries scattered * throughout the directory tree. First there is the directory entry * with the name of the directory stored in the parent directory. * Then, there is the "." directory entry stored in the directory * itself. Finally, there are possibly many ".." directory entries * stored in all the subdirectories. * * In order for the NFS get_parent() method to work and for the * general consistency of the dcache, we need to make sure the * "i_iget5_block" and "i_iget5_offset" all point to exactly one of * the many redundant entries for each directory. We normalize the * block and offset by always making them point to the "." directory. * * Notice that we do not use the entry for the directory with the name * that is located in the parent directory. Even though choosing this * first directory is more natural, it is much easier to find the "." * entry in the NFS get_parent() method because it is implicitly * encoded in the "extent + ext_attr_length" fields of _all_ the * redundant entries for the directory. Thus, it can always be * reached regardless of which directory entry you have in hand. * * This works because the "." entry is simply the first directory * record when you start reading the file that holds all the directory * records, and this file starts at "extent + ext_attr_length" blocks. * Because the "." entry is always the first entry listed in the * directories file, the normalized "offset" value is always 0. * * You should pass the directory entry in "de". On return, "block" * and "offset" will hold normalized values. Only directories are * affected making it safe to call even for non-directory file * types. */ static inline void isofs_normalize_block_and_offset(struct iso_directory_record* de, unsigned long *block, unsigned long *offset) { /* Only directories are normalized. */ if (de->flags[0] & 2) { *offset = 0; *block = (unsigned long)isonum_733(de->extent) + (unsigned long)isonum_711(de->ext_attr_length); } } extern const struct inode_operations isofs_dir_inode_operations; extern const struct file_operations isofs_dir_operations; extern const struct address_space_operations isofs_symlink_aops; extern const struct export_operations isofs_export_ops;
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 /* * linux/include/video/vga.h -- standard VGA chipset interaction * * Copyright 1999 Jeff Garzik <jgarzik@pobox.com> * * Copyright history from vga16fb.c: * Copyright 1999 Ben Pfaff and Petr Vandrovec * Based on VGA info at http://www.osdever.net/FreeVGA/home.htm * Based on VESA framebuffer (c) 1998 Gerd Knorr * * This file is subject to the terms and conditions of the GNU General * Public License. See the file COPYING in the main directory of this * archive for more details. * */ #ifndef __linux_video_vga_h__ #define __linux_video_vga_h__ #include <linux/types.h> #include <linux/io.h> #include <asm/vga.h> #include <asm/byteorder.h> /* Some of the code below is taken from SVGAlib. The original, unmodified copyright notice for that code is below. */ /* VGAlib version 1.2 - (c) 1993 Tommy Frandsen */ /* */ /* This library is free software; you can redistribute it and/or */ /* modify it without any restrictions. This library is distributed */ /* in the hope that it will be useful, but without any warranty. */ /* Multi-chipset support Copyright 1993 Harm Hanemaayer */ /* partially copyrighted (C) 1993 by Hartmut Schirmer */ /* VGA data register ports */ #define VGA_CRT_DC 0x3D5 /* CRT Controller Data Register - color emulation */ #define VGA_CRT_DM 0x3B5 /* CRT Controller Data Register - mono emulation */ #define VGA_ATT_R 0x3C1 /* Attribute Controller Data Read Register */ #define VGA_ATT_W 0x3C0 /* Attribute Controller Data Write Register */ #define VGA_GFX_D 0x3CF /* Graphics Controller Data Register */ #define VGA_SEQ_D 0x3C5 /* Sequencer Data Register */ #define VGA_MIS_R 0x3CC /* Misc Output Read Register */ #define VGA_MIS_W 0x3C2 /* Misc Output Write Register */ #define VGA_FTC_R 0x3CA /* Feature Control Read Register */ #define VGA_IS1_RC 0x3DA /* Input Status Register 1 - color emulation */ #define VGA_IS1_RM 0x3BA /* Input Status Register 1 - mono emulation */ #define VGA_PEL_D 0x3C9 /* PEL Data Register */ #define VGA_PEL_MSK 0x3C6 /* PEL mask register */ /* EGA-specific registers */ #define EGA_GFX_E0 0x3CC /* Graphics enable processor 0 */ #define EGA_GFX_E1 0x3CA /* Graphics enable processor 1 */ /* VGA index register ports */ #define VGA_CRT_IC 0x3D4 /* CRT Controller Index - color emulation */ #define VGA_CRT_IM 0x3B4 /* CRT Controller Index - mono emulation */ #define VGA_ATT_IW 0x3C0 /* Attribute Controller Index & Data Write Register */ #define VGA_GFX_I 0x3CE /* Graphics Controller Index */ #define VGA_SEQ_I 0x3C4 /* Sequencer Index */ #define VGA_PEL_IW 0x3C8 /* PEL Write Index */ #define VGA_PEL_IR 0x3C7 /* PEL Read Index */ /* standard VGA indexes max counts */ #define VGA_CRT_C 0x19 /* Number of CRT Controller Registers */ #define VGA_ATT_C 0x15 /* Number of Attribute Controller Registers */ #define VGA_GFX_C 0x09 /* Number of Graphics Controller Registers */ #define VGA_SEQ_C 0x05 /* Number of Sequencer Registers */ #define VGA_MIS_C 0x01 /* Number of Misc Output Register */ /* VGA misc register bit masks */ #define VGA_MIS_COLOR 0x01 #define VGA_MIS_ENB_MEM_ACCESS 0x02 #define VGA_MIS_DCLK_28322_720 0x04 #define VGA_MIS_ENB_PLL_LOAD (0x04 | 0x08) #define VGA_MIS_SEL_HIGH_PAGE 0x20 /* VGA CRT controller register indices */ #define VGA_CRTC_H_TOTAL 0 #define VGA_CRTC_H_DISP 1 #define VGA_CRTC_H_BLANK_START 2 #define VGA_CRTC_H_BLANK_END 3 #define VGA_CRTC_H_SYNC_START 4 #define VGA_CRTC_H_SYNC_END 5 #define VGA_CRTC_V_TOTAL 6 #define VGA_CRTC_OVERFLOW 7 #define VGA_CRTC_PRESET_ROW 8 #define VGA_CRTC_MAX_SCAN 9 #define VGA_CRTC_CURSOR_START 0x0A #define VGA_CRTC_CURSOR_END 0x0B #define VGA_CRTC_START_HI 0x0C #define VGA_CRTC_START_LO 0x0D #define VGA_CRTC_CURSOR_HI 0x0E #define VGA_CRTC_CURSOR_LO 0x0F #define VGA_CRTC_V_SYNC_START 0x10 #define VGA_CRTC_V_SYNC_END 0x11 #define VGA_CRTC_V_DISP_END 0x12 #define VGA_CRTC_OFFSET 0x13 #define VGA_CRTC_UNDERLINE 0x14 #define VGA_CRTC_V_BLANK_START 0x15 #define VGA_CRTC_V_BLANK_END 0x16 #define VGA_CRTC_MODE 0x17 #define VGA_CRTC_LINE_COMPARE 0x18 #define VGA_CRTC_REGS VGA_CRT_C /* VGA CRT controller bit masks */ #define VGA_CR11_LOCK_CR0_CR7 0x80 /* lock writes to CR0 - CR7 */ #define VGA_CR17_H_V_SIGNALS_ENABLED 0x80 /* VGA attribute controller register indices */ #define VGA_ATC_PALETTE0 0x00 #define VGA_ATC_PALETTE1 0x01 #define VGA_ATC_PALETTE2 0x02 #define VGA_ATC_PALETTE3 0x03 #define VGA_ATC_PALETTE4 0x04 #define VGA_ATC_PALETTE5 0x05 #define VGA_ATC_PALETTE6 0x06 #define VGA_ATC_PALETTE7 0x07 #define VGA_ATC_PALETTE8 0x08 #define VGA_ATC_PALETTE9 0x09 #define VGA_ATC_PALETTEA 0x0A #define VGA_ATC_PALETTEB 0x0B #define VGA_ATC_PALETTEC 0x0C #define VGA_ATC_PALETTED 0x0D #define VGA_ATC_PALETTEE 0x0E #define VGA_ATC_PALETTEF 0x0F #define VGA_ATC_MODE 0x10 #define VGA_ATC_OVERSCAN 0x11 #define VGA_ATC_PLANE_ENABLE 0x12 #define VGA_ATC_PEL 0x13 #define VGA_ATC_COLOR_PAGE 0x14 #define VGA_AR_ENABLE_DISPLAY 0x20 /* VGA sequencer register indices */ #define VGA_SEQ_RESET 0x00 #define VGA_SEQ_CLOCK_MODE 0x01 #define VGA_SEQ_PLANE_WRITE 0x02 #define VGA_SEQ_CHARACTER_MAP 0x03 #define VGA_SEQ_MEMORY_MODE 0x04 /* VGA sequencer register bit masks */ #define VGA_SR01_CHAR_CLK_8DOTS 0x01 /* bit 0: character clocks 8 dots wide are generated */ #define VGA_SR01_SCREEN_OFF 0x20 /* bit 5: Screen is off */ #define VGA_SR02_ALL_PLANES 0x0F /* bits 3-0: enable access to all planes */ #define VGA_SR04_EXT_MEM 0x02 /* bit 1: allows complete mem access to 256K */ #define VGA_SR04_SEQ_MODE 0x04 /* bit 2: directs system to use a sequential addressing mode */ #define VGA_SR04_CHN_4M 0x08 /* bit 3: selects modulo 4 addressing for CPU access to display memory */ /* VGA graphics controller register indices */ #define VGA_GFX_SR_VALUE 0x00 #define VGA_GFX_SR_ENABLE 0x01 #define VGA_GFX_COMPARE_VALUE 0x02 #define VGA_GFX_DATA_ROTATE 0x03 #define VGA_GFX_PLANE_READ 0x04 #define VGA_GFX_MODE 0x05 #define VGA_GFX_MISC 0x06 #define VGA_GFX_COMPARE_MASK 0x07 #define VGA_GFX_BIT_MASK 0x08 /* VGA graphics controller bit masks */ #define VGA_GR06_GRAPHICS_MODE 0x01 /* macro for composing an 8-bit VGA register index and value * into a single 16-bit quantity */ #define VGA_OUT16VAL(v, r) (((v) << 8) | (r)) /* decide whether we should enable the faster 16-bit VGA register writes */ #ifdef __LITTLE_ENDIAN #define VGA_OUTW_WRITE #endif /* VGA State Save and Restore */ #define VGA_SAVE_FONT0 1 /* save/restore plane 2 fonts */ #define VGA_SAVE_FONT1 2 /* save/restore plane 3 fonts */ #define VGA_SAVE_TEXT 4 /* save/restore plane 0/1 fonts */ #define VGA_SAVE_FONTS 7 /* save/restore all fonts */ #define VGA_SAVE_MODE 8 /* save/restore video mode */ #define VGA_SAVE_CMAP 16 /* save/restore color map/DAC */ struct vgastate { void __iomem *vgabase; /* mmio base, if supported */ unsigned long membase; /* VGA window base, 0 for default - 0xA000 */ __u32 memsize; /* VGA window size, 0 for default 64K */ __u32 flags; /* what state[s] to save (see VGA_SAVE_*) */ __u32 depth; /* current fb depth, not important */ __u32 num_attr; /* number of att registers, 0 for default */ __u32 num_crtc; /* number of crt registers, 0 for default */ __u32 num_gfx; /* number of gfx registers, 0 for default */ __u32 num_seq; /* number of seq registers, 0 for default */ void *vidstate; }; extern int save_vga(struct vgastate *state); extern int restore_vga(struct vgastate *state); /* * generic VGA port read/write */ static inline unsigned char vga_io_r (unsigned short port) { return inb_p(port); } static inline void vga_io_w (unsigned short port, unsigned char val) { outb_p(val, port); } static inline void vga_io_w_fast (unsigned short port, unsigned char reg, unsigned char val) { outw(VGA_OUT16VAL (val, reg), port); } static inline unsigned char vga_mm_r (void __iomem *regbase, unsigned short port) { return readb (regbase + port); } static inline void vga_mm_w (void __iomem *regbase, unsigned short port, unsigned char val) { writeb (val, regbase + port); } static inline void vga_mm_w_fast (void __iomem *regbase, unsigned short port, unsigned char reg, unsigned char val) { writew (VGA_OUT16VAL (val, reg), regbase + port); } static inline unsigned char vga_r (void __iomem *regbase, unsigned short port) { if (regbase) return vga_mm_r (regbase, port); else return vga_io_r (port); } static inline void vga_w (void __iomem *regbase, unsigned short port, unsigned char val) { if (regbase) vga_mm_w (regbase, port, val); else vga_io_w (port, val); } static inline void vga_w_fast (void __iomem *regbase, unsigned short port, unsigned char reg, unsigned char val) { if (regbase) vga_mm_w_fast (regbase, port, reg, val); else vga_io_w_fast (port, reg, val); } /* * VGA CRTC register read/write */ static inline unsigned char vga_rcrt (void __iomem *regbase, unsigned char reg) { vga_w (regbase, VGA_CRT_IC, reg); return vga_r (regbase, VGA_CRT_DC); } static inline void vga_wcrt (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_w_fast (regbase, VGA_CRT_IC, reg, val); #else vga_w (regbase, VGA_CRT_IC, reg); vga_w (regbase, VGA_CRT_DC, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_io_rcrt (unsigned char reg) { vga_io_w (VGA_CRT_IC, reg); return vga_io_r (VGA_CRT_DC); } static inline void vga_io_wcrt (unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_io_w_fast (VGA_CRT_IC, reg, val); #else vga_io_w (VGA_CRT_IC, reg); vga_io_w (VGA_CRT_DC, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_mm_rcrt (void __iomem *regbase, unsigned char reg) { vga_mm_w (regbase, VGA_CRT_IC, reg); return vga_mm_r (regbase, VGA_CRT_DC); } static inline void vga_mm_wcrt (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_mm_w_fast (regbase, VGA_CRT_IC, reg, val); #else vga_mm_w (regbase, VGA_CRT_IC, reg); vga_mm_w (regbase, VGA_CRT_DC, val); #endif /* VGA_OUTW_WRITE */ } /* * VGA sequencer register read/write */ static inline unsigned char vga_rseq (void __iomem *regbase, unsigned char reg) { vga_w (regbase, VGA_SEQ_I, reg); return vga_r (regbase, VGA_SEQ_D); } static inline void vga_wseq (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_w_fast (regbase, VGA_SEQ_I, reg, val); #else vga_w (regbase, VGA_SEQ_I, reg); vga_w (regbase, VGA_SEQ_D, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_io_rseq (unsigned char reg) { vga_io_w (VGA_SEQ_I, reg); return vga_io_r (VGA_SEQ_D); } static inline void vga_io_wseq (unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_io_w_fast (VGA_SEQ_I, reg, val); #else vga_io_w (VGA_SEQ_I, reg); vga_io_w (VGA_SEQ_D, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_mm_rseq (void __iomem *regbase, unsigned char reg) { vga_mm_w (regbase, VGA_SEQ_I, reg); return vga_mm_r (regbase, VGA_SEQ_D); } static inline void vga_mm_wseq (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_mm_w_fast (regbase, VGA_SEQ_I, reg, val); #else vga_mm_w (regbase, VGA_SEQ_I, reg); vga_mm_w (regbase, VGA_SEQ_D, val); #endif /* VGA_OUTW_WRITE */ } /* * VGA graphics controller register read/write */ static inline unsigned char vga_rgfx (void __iomem *regbase, unsigned char reg) { vga_w (regbase, VGA_GFX_I, reg); return vga_r (regbase, VGA_GFX_D); } static inline void vga_wgfx (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_w_fast (regbase, VGA_GFX_I, reg, val); #else vga_w (regbase, VGA_GFX_I, reg); vga_w (regbase, VGA_GFX_D, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_io_rgfx (unsigned char reg) { vga_io_w (VGA_GFX_I, reg); return vga_io_r (VGA_GFX_D); } static inline void vga_io_wgfx (unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_io_w_fast (VGA_GFX_I, reg, val); #else vga_io_w (VGA_GFX_I, reg); vga_io_w (VGA_GFX_D, val); #endif /* VGA_OUTW_WRITE */ } static inline unsigned char vga_mm_rgfx (void __iomem *regbase, unsigned char reg) { vga_mm_w (regbase, VGA_GFX_I, reg); return vga_mm_r (regbase, VGA_GFX_D); } static inline void vga_mm_wgfx (void __iomem *regbase, unsigned char reg, unsigned char val) { #ifdef VGA_OUTW_WRITE vga_mm_w_fast (regbase, VGA_GFX_I, reg, val); #else vga_mm_w (regbase, VGA_GFX_I, reg); vga_mm_w (regbase, VGA_GFX_D, val); #endif /* VGA_OUTW_WRITE */ } /* * VGA attribute controller register read/write */ static inline unsigned char vga_rattr (void __iomem *regbase, unsigned char reg) { vga_w (regbase, VGA_ATT_IW, reg); return vga_r (regbase, VGA_ATT_R); } static inline void vga_wattr (void __iomem *regbase, unsigned char reg, unsigned char val) { vga_w (regbase, VGA_ATT_IW, reg); vga_w (regbase, VGA_ATT_W, val); } static inline unsigned char vga_io_rattr (unsigned char reg) { vga_io_w (VGA_ATT_IW, reg); return vga_io_r (VGA_ATT_R); } static inline void vga_io_wattr (unsigned char reg, unsigned char val) { vga_io_w (VGA_ATT_IW, reg); vga_io_w (VGA_ATT_W, val); } static inline unsigned char vga_mm_rattr (void __iomem *regbase, unsigned char reg) { vga_mm_w (regbase, VGA_ATT_IW, reg); return vga_mm_r (regbase, VGA_ATT_R); } static inline void vga_mm_wattr (void __iomem *regbase, unsigned char reg, unsigned char val) { vga_mm_w (regbase, VGA_ATT_IW, reg); vga_mm_w (regbase, VGA_ATT_W, val); } #endif /* __linux_video_vga_h__ */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 /* SPDX-License-Identifier: GPL-2.0-or-later */ /* Integer base 2 logarithm calculation * * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #ifndef _LINUX_LOG2_H #define _LINUX_LOG2_H #include <linux/types.h> #include <linux/bitops.h> /* * non-constant log of base 2 calculators * - the arch may override these in asm/bitops.h if they can be implemented * more efficiently than using fls() and fls64() * - the arch is not required to handle n==0 if implementing the fallback */ #ifndef CONFIG_ARCH_HAS_ILOG2_U32 static inline __attribute__((const)) int __ilog2_u32(u32 n) { return fls(n) - 1; } #endif #ifndef CONFIG_ARCH_HAS_ILOG2_U64 static inline __attribute__((const)) int __ilog2_u64(u64 n) { return fls64(n) - 1; } #endif /** * is_power_of_2() - check if a value is a power of two * @n: the value to check * * Determine whether some value is a power of two, where zero is * *not* considered a power of two. * Return: true if @n is a power of 2, otherwise false. */ static inline __attribute__((const)) bool is_power_of_2(unsigned long n) { return (n != 0 && ((n & (n - 1)) == 0)); } /** * __roundup_pow_of_two() - round up to nearest power of two * @n: value to round up */ static inline __attribute__((const)) unsigned long __roundup_pow_of_two(unsigned long n) { return 1UL << fls_long(n - 1); } /** * __rounddown_pow_of_two() - round down to nearest power of two * @n: value to round down */ static inline __attribute__((const)) unsigned long __rounddown_pow_of_two(unsigned long n) { return 1UL << (fls_long(n) - 1); } /** * const_ilog2 - log base 2 of 32-bit or a 64-bit constant unsigned value * @n: parameter * * Use this where sparse expects a true constant expression, e.g. for array * indices. */ #define const_ilog2(n) \ ( \ __builtin_constant_p(n) ? ( \ (n) < 2 ? 0 : \ (n) & (1ULL << 63) ? 63 : \ (n) & (1ULL << 62) ? 62 : \ (n) & (1ULL << 61) ? 61 : \ (n) & (1ULL << 60) ? 60 : \ (n) & (1ULL << 59) ? 59 : \ (n) & (1ULL << 58) ? 58 : \ (n) & (1ULL << 57) ? 57 : \ (n) & (1ULL << 56) ? 56 : \ (n) & (1ULL << 55) ? 55 : \ (n) & (1ULL << 54) ? 54 : \ (n) & (1ULL << 53) ? 53 : \ (n) & (1ULL << 52) ? 52 : \ (n) & (1ULL << 51) ? 51 : \ (n) & (1ULL << 50) ? 50 : \ (n) & (1ULL << 49) ? 49 : \ (n) & (1ULL << 48) ? 48 : \ (n) & (1ULL << 47) ? 47 : \ (n) & (1ULL << 46) ? 46 : \ (n) & (1ULL << 45) ? 45 : \ (n) & (1ULL << 44) ? 44 : \ (n) & (1ULL << 43) ? 43 : \ (n) & (1ULL << 42) ? 42 : \ (n) & (1ULL << 41) ? 41 : \ (n) & (1ULL << 40) ? 40 : \ (n) & (1ULL << 39) ? 39 : \ (n) & (1ULL << 38) ? 38 : \ (n) & (1ULL << 37) ? 37 : \ (n) & (1ULL << 36) ? 36 : \ (n) & (1ULL << 35) ? 35 : \ (n) & (1ULL << 34) ? 34 : \ (n) & (1ULL << 33) ? 33 : \ (n) & (1ULL << 32) ? 32 : \ (n) & (1ULL << 31) ? 31 : \ (n) & (1ULL << 30) ? 30 : \ (n) & (1ULL << 29) ? 29 : \ (n) & (1ULL << 28) ? 28 : \ (n) & (1ULL << 27) ? 27 : \ (n) & (1ULL << 26) ? 26 : \ (n) & (1ULL << 25) ? 25 : \ (n) & (1ULL << 24) ? 24 : \ (n) & (1ULL << 23) ? 23 : \ (n) & (1ULL << 22) ? 22 : \ (n) & (1ULL << 21) ? 21 : \ (n) & (1ULL << 20) ? 20 : \ (n) & (1ULL << 19) ? 19 : \ (n) & (1ULL << 18) ? 18 : \ (n) & (1ULL << 17) ? 17 : \ (n) & (1ULL << 16) ? 16 : \ (n) & (1ULL << 15) ? 15 : \ (n) & (1ULL << 14) ? 14 : \ (n) & (1ULL << 13) ? 13 : \ (n) & (1ULL << 12) ? 12 : \ (n) & (1ULL << 11) ? 11 : \ (n) & (1ULL << 10) ? 10 : \ (n) & (1ULL << 9) ? 9 : \ (n) & (1ULL << 8) ? 8 : \ (n) & (1ULL << 7) ? 7 : \ (n) & (1ULL << 6) ? 6 : \ (n) & (1ULL << 5) ? 5 : \ (n) & (1ULL << 4) ? 4 : \ (n) & (1ULL << 3) ? 3 : \ (n) & (1ULL << 2) ? 2 : \ 1) : \ -1) /** * ilog2 - log base 2 of 32-bit or a 64-bit unsigned value * @n: parameter * * constant-capable log of base 2 calculation * - this can be used to initialise global variables from constant data, hence * the massive ternary operator construction * * selects the appropriately-sized optimised version depending on sizeof(n) */ #define ilog2(n) \ ( \ __builtin_constant_p(n) ? \ const_ilog2(n) : \ (sizeof(n) <= 4) ? \ __ilog2_u32(n) : \ __ilog2_u64(n) \ ) /** * roundup_pow_of_two - round the given value up to nearest power of two * @n: parameter * * round the given value up to the nearest power of two * - the result is undefined when n == 0 * - this can be used to initialise global variables from constant data */ #define roundup_pow_of_two(n) \ ( \ __builtin_constant_p(n) ? ( \ ((n) == 1) ? 1 : \ (1UL << (ilog2((n) - 1) + 1)) \ ) : \ __roundup_pow_of_two(n) \ ) /** * rounddown_pow_of_two - round the given value down to nearest power of two * @n: parameter * * round the given value down to the nearest power of two * - the result is undefined when n == 0 * - this can be used to initialise global variables from constant data */ #define rounddown_pow_of_two(n) \ ( \ __builtin_constant_p(n) ? ( \ (1UL << ilog2(n))) : \ __rounddown_pow_of_two(n) \ ) static inline __attribute_const__ int __order_base_2(unsigned long n) { return n > 1 ? ilog2(n - 1) + 1 : 0; } /** * order_base_2 - calculate the (rounded up) base 2 order of the argument * @n: parameter * * The first few values calculated by this routine: * ob2(0) = 0 * ob2(1) = 0 * ob2(2) = 1 * ob2(3) = 2 * ob2(4) = 2 * ob2(5) = 3 * ... and so on. */ #define order_base_2(n) \ ( \ __builtin_constant_p(n) ? ( \ ((n) == 0 || (n) == 1) ? 0 : \ ilog2((n) - 1) + 1) : \ __order_base_2(n) \ ) static inline __attribute__((const)) int __bits_per(unsigned long n) { if (n < 2) return 1; if (is_power_of_2(n)) return order_base_2(n) + 1; return order_base_2(n); } /** * bits_per - calculate the number of bits required for the argument * @n: parameter * * This is constant-capable and can be used for compile time * initializations, e.g bitfields. * * The first few values calculated by this routine: * bf(0) = 1 * bf(1) = 1 * bf(2) = 2 * bf(3) = 2 * bf(4) = 3 * ... and so on. */ #define bits_per(n) \ ( \ __builtin_constant_p(n) ? ( \ ((n) == 0 || (n) == 1) \ ? 1 : ilog2(n) + 1 \ ) : \ __bits_per(n) \ ) #endif /* _LINUX_LOG2_H */
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3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 // SPDX-License-Identifier: GPL-2.0-only /* * mm/mmap.c * * Written by obz. * * Address space accounting code <alan@lxorguk.ukuu.org.uk> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/slab.h> #include <linux/backing-dev.h> #include <linux/mm.h> #include <linux/vmacache.h> #include <linux/shm.h> #include <linux/mman.h> #include <linux/pagemap.h> #include <linux/swap.h> #include <linux/syscalls.h> #include <linux/capability.h> #include <linux/init.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/personality.h> #include <linux/security.h> #include <linux/hugetlb.h> #include <linux/shmem_fs.h> #include <linux/profile.h> #include <linux/export.h> #include <linux/mount.h> #include <linux/mempolicy.h> #include <linux/rmap.h> #include <linux/mmu_notifier.h> #include <linux/mmdebug.h> #include <linux/perf_event.h> #include <linux/audit.h> #include <linux/khugepaged.h> #include <linux/uprobes.h> #include <linux/rbtree_augmented.h> #include <linux/notifier.h> #include <linux/memory.h> #include <linux/printk.h> #include <linux/userfaultfd_k.h> #include <linux/moduleparam.h> #include <linux/pkeys.h> #include <linux/oom.h> #include <linux/sched/mm.h> #include <linux/uaccess.h> #include <asm/cacheflush.h> #include <asm/tlb.h> #include <asm/mmu_context.h> #define CREATE_TRACE_POINTS #include <trace/events/mmap.h> #include "internal.h" #ifndef arch_mmap_check #define arch_mmap_check(addr, len, flags) (0) #endif #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS const int mmap_rnd_bits_min = CONFIG_ARCH_MMAP_RND_BITS_MIN; const int mmap_rnd_bits_max = CONFIG_ARCH_MMAP_RND_BITS_MAX; int mmap_rnd_bits __read_mostly = CONFIG_ARCH_MMAP_RND_BITS; #endif #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS const int mmap_rnd_compat_bits_min = CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MIN; const int mmap_rnd_compat_bits_max = CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX; int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS; #endif static bool ignore_rlimit_data; core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644); static void unmap_region(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, unsigned long start, unsigned long end); /* description of effects of mapping type and prot in current implementation. * this is due to the limited x86 page protection hardware. The expected * behavior is in parens: * * map_type prot * PROT_NONE PROT_READ PROT_WRITE PROT_EXEC * MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes * w: (no) no w: (no) no w: (yes) yes w: (no) no * x: (no) no x: (no) yes x: (no) yes x: (yes) yes * * MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes * w: (no) no w: (no) no w: (copy) copy w: (no) no * x: (no) no x: (no) yes x: (no) yes x: (yes) yes */ pgprot_t protection_map[16] __ro_after_init = { __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 }; #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT static inline pgprot_t arch_filter_pgprot(pgprot_t prot) { return prot; } #endif pgprot_t vm_get_page_prot(unsigned long vm_flags) { pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | pgprot_val(arch_vm_get_page_prot(vm_flags))); return arch_filter_pgprot(ret); } EXPORT_SYMBOL(vm_get_page_prot); static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags) { return pgprot_modify(oldprot, vm_get_page_prot(vm_flags)); } /* Update vma->vm_page_prot to reflect vma->vm_flags. */ void vma_set_page_prot(struct vm_area_struct *vma) { unsigned long vm_flags = vma->vm_flags; pgprot_t vm_page_prot; vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, vm_flags); if (vma_wants_writenotify(vma, vm_page_prot)) { vm_flags &= ~VM_SHARED; vm_page_prot = vm_pgprot_modify(vm_page_prot, vm_flags); } /* remove_protection_ptes reads vma->vm_page_prot without mmap_lock */ WRITE_ONCE(vma->vm_page_prot, vm_page_prot); } /* * Requires inode->i_mapping->i_mmap_rwsem */ static void __remove_shared_vm_struct(struct vm_area_struct *vma, struct file *file, struct address_space *mapping) { if (vma->vm_flags & VM_DENYWRITE) allow_write_access(file); if (vma->vm_flags & VM_SHARED) mapping_unmap_writable(mapping); flush_dcache_mmap_lock(mapping); vma_interval_tree_remove(vma, &mapping->i_mmap); flush_dcache_mmap_unlock(mapping); } /* * Unlink a file-based vm structure from its interval tree, to hide * vma from rmap and vmtruncate before freeing its page tables. */ void unlink_file_vma(struct vm_area_struct *vma) { struct file *file = vma->vm_file; if (file) { struct address_space *mapping = file->f_mapping; i_mmap_lock_write(mapping); __remove_shared_vm_struct(vma, file, mapping); i_mmap_unlock_write(mapping); } } /* * Close a vm structure and free it, returning the next. */ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) { struct vm_area_struct *next = vma->vm_next; might_sleep(); if (vma->vm_ops && vma->vm_ops->close) vma->vm_ops->close(vma); if (vma->vm_file) fput(vma->vm_file); mpol_put(vma_policy(vma)); vm_area_free(vma); return next; } static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags, struct list_head *uf); SYSCALL_DEFINE1(brk, unsigned long, brk) { unsigned long retval; unsigned long newbrk, oldbrk, origbrk; struct mm_struct *mm = current->mm; struct vm_area_struct *next; unsigned long min_brk; bool populate; bool downgraded = false; LIST_HEAD(uf); if (mmap_write_lock_killable(mm)) return -EINTR; origbrk = mm->brk; #ifdef CONFIG_COMPAT_BRK /* * CONFIG_COMPAT_BRK can still be overridden by setting * randomize_va_space to 2, which will still cause mm->start_brk * to be arbitrarily shifted */ if (current->brk_randomized) min_brk = mm->start_brk; else min_brk = mm->end_data; #else min_brk = mm->start_brk; #endif if (brk < min_brk) goto out; /* * Check against rlimit here. If this check is done later after the test * of oldbrk with newbrk then it can escape the test and let the data * segment grow beyond its set limit the in case where the limit is * not page aligned -Ram Gupta */ if (check_data_rlimit(rlimit(RLIMIT_DATA), brk, mm->start_brk, mm->end_data, mm->start_data)) goto out; newbrk = PAGE_ALIGN(brk); oldbrk = PAGE_ALIGN(mm->brk); if (oldbrk == newbrk) { mm->brk = brk; goto success; } /* * Always allow shrinking brk. * __do_munmap() may downgrade mmap_lock to read. */ if (brk <= mm->brk) { int ret; /* * mm->brk must to be protected by write mmap_lock so update it * before downgrading mmap_lock. When __do_munmap() fails, * mm->brk will be restored from origbrk. */ mm->brk = brk; ret = __do_munmap(mm, newbrk, oldbrk-newbrk, &uf, true); if (ret < 0) { mm->brk = origbrk; goto out; } else if (ret == 1) { downgraded = true; } goto success; } /* Check against existing mmap mappings. */ next = find_vma(mm, oldbrk); if (next && newbrk + PAGE_SIZE > vm_start_gap(next)) goto out; /* Ok, looks good - let it rip. */ if (do_brk_flags(oldbrk, newbrk-oldbrk, 0, &uf) < 0) goto out; mm->brk = brk; success: populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0; if (downgraded) mmap_read_unlock(mm); else mmap_write_unlock(mm); userfaultfd_unmap_complete(mm, &uf); if (populate) mm_populate(oldbrk, newbrk - oldbrk); return brk; out: retval = origbrk; mmap_write_unlock(mm); return retval; } static inline unsigned long vma_compute_gap(struct vm_area_struct *vma) { unsigned long gap, prev_end; /* * Note: in the rare case of a VM_GROWSDOWN above a VM_GROWSUP, we * allow two stack_guard_gaps between them here, and when choosing * an unmapped area; whereas when expanding we only require one. * That's a little inconsistent, but keeps the code here simpler. */ gap = vm_start_gap(vma); if (vma->vm_prev) { prev_end = vm_end_gap(vma->vm_prev); if (gap > prev_end) gap -= prev_end; else gap = 0; } return gap; } #ifdef CONFIG_DEBUG_VM_RB static unsigned long vma_compute_subtree_gap(struct vm_area_struct *vma) { unsigned long max = vma_compute_gap(vma), subtree_gap; if (vma->vm_rb.rb_left) { subtree_gap = rb_entry(vma->vm_rb.rb_left, struct vm_area_struct, vm_rb)->rb_subtree_gap; if (subtree_gap > max) max = subtree_gap; } if (vma->vm_rb.rb_right) { subtree_gap = rb_entry(vma->vm_rb.rb_right, struct vm_area_struct, vm_rb)->rb_subtree_gap; if (subtree_gap > max) max = subtree_gap; } return max; } static int browse_rb(struct mm_struct *mm) { struct rb_root *root = &mm->mm_rb; int i = 0, j, bug = 0; struct rb_node *nd, *pn = NULL; unsigned long prev = 0, pend = 0; for (nd = rb_first(root); nd; nd = rb_next(nd)) { struct vm_area_struct *vma; vma = rb_entry(nd, struct vm_area_struct, vm_rb); if (vma->vm_start < prev) { pr_emerg("vm_start %lx < prev %lx\n", vma->vm_start, prev); bug = 1; } if (vma->vm_start < pend) { pr_emerg("vm_start %lx < pend %lx\n", vma->vm_start, pend); bug = 1; } if (vma->vm_start > vma->vm_end) { pr_emerg("vm_start %lx > vm_end %lx\n", vma->vm_start, vma->vm_end); bug = 1; } spin_lock(&mm->page_table_lock); if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) { pr_emerg("free gap %lx, correct %lx\n", vma->rb_subtree_gap, vma_compute_subtree_gap(vma)); bug = 1; } spin_unlock(&mm->page_table_lock); i++; pn = nd; prev = vma->vm_start; pend = vma->vm_end; } j = 0; for (nd = pn; nd; nd = rb_prev(nd)) j++; if (i != j) { pr_emerg("backwards %d, forwards %d\n", j, i); bug = 1; } return bug ? -1 : i; } static void validate_mm_rb(struct rb_root *root, struct vm_area_struct *ignore) { struct rb_node *nd; for (nd = rb_first(root); nd; nd = rb_next(nd)) { struct vm_area_struct *vma; vma = rb_entry(nd, struct vm_area_struct, vm_rb); VM_BUG_ON_VMA(vma != ignore && vma->rb_subtree_gap != vma_compute_subtree_gap(vma), vma); } } static void validate_mm(struct mm_struct *mm) { int bug = 0; int i = 0; unsigned long highest_address = 0; struct vm_area_struct *vma = mm->mmap; while (vma) { struct anon_vma *anon_vma = vma->anon_vma; struct anon_vma_chain *avc; if (anon_vma) { anon_vma_lock_read(anon_vma); list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_verify(avc); anon_vma_unlock_read(anon_vma); } highest_address = vm_end_gap(vma); vma = vma->vm_next; i++; } if (i != mm->map_count) { pr_emerg("map_count %d vm_next %d\n", mm->map_count, i); bug = 1; } if (highest_address != mm->highest_vm_end) { pr_emerg("mm->highest_vm_end %lx, found %lx\n", mm->highest_vm_end, highest_address); bug = 1; } i = browse_rb(mm); if (i != mm->map_count) { if (i != -1) pr_emerg("map_count %d rb %d\n", mm->map_count, i); bug = 1; } VM_BUG_ON_MM(bug, mm); } #else #define validate_mm_rb(root, ignore) do { } while (0) #define validate_mm(mm) do { } while (0) #endif RB_DECLARE_CALLBACKS_MAX(static, vma_gap_callbacks, struct vm_area_struct, vm_rb, unsigned long, rb_subtree_gap, vma_compute_gap) /* * Update augmented rbtree rb_subtree_gap values after vma->vm_start or * vma->vm_prev->vm_end values changed, without modifying the vma's position * in the rbtree. */ static void vma_gap_update(struct vm_area_struct *vma) { /* * As it turns out, RB_DECLARE_CALLBACKS_MAX() already created * a callback function that does exactly what we want. */ vma_gap_callbacks_propagate(&vma->vm_rb, NULL); } static inline void vma_rb_insert(struct vm_area_struct *vma, struct rb_root *root) { /* All rb_subtree_gap values must be consistent prior to insertion */ validate_mm_rb(root, NULL); rb_insert_augmented(&vma->vm_rb, root, &vma_gap_callbacks); } static void __vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root) { /* * Note rb_erase_augmented is a fairly large inline function, * so make sure we instantiate it only once with our desired * augmented rbtree callbacks. */ rb_erase_augmented(&vma->vm_rb, root, &vma_gap_callbacks); } static __always_inline void vma_rb_erase_ignore(struct vm_area_struct *vma, struct rb_root *root, struct vm_area_struct *ignore) { /* * All rb_subtree_gap values must be consistent prior to erase, * with the possible exception of * * a. the "next" vma being erased if next->vm_start was reduced in * __vma_adjust() -> __vma_unlink() * b. the vma being erased in detach_vmas_to_be_unmapped() -> * vma_rb_erase() */ validate_mm_rb(root, ignore); __vma_rb_erase(vma, root); } static __always_inline void vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root) { vma_rb_erase_ignore(vma, root, vma); } /* * vma has some anon_vma assigned, and is already inserted on that * anon_vma's interval trees. * * Before updating the vma's vm_start / vm_end / vm_pgoff fields, the * vma must be removed from the anon_vma's interval trees using * anon_vma_interval_tree_pre_update_vma(). * * After the update, the vma will be reinserted using * anon_vma_interval_tree_post_update_vma(). * * The entire update must be protected by exclusive mmap_lock and by * the root anon_vma's mutex. */ static inline void anon_vma_interval_tree_pre_update_vma(struct vm_area_struct *vma) { struct anon_vma_chain *avc; list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_remove(avc, &avc->anon_vma->rb_root); } static inline void anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma) { struct anon_vma_chain *avc; list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root); } static int find_vma_links(struct mm_struct *mm, unsigned long addr, unsigned long end, struct vm_area_struct **pprev, struct rb_node ***rb_link, struct rb_node **rb_parent) { struct rb_node **__rb_link, *__rb_parent, *rb_prev; __rb_link = &mm->mm_rb.rb_node; rb_prev = __rb_parent = NULL; while (*__rb_link) { struct vm_area_struct *vma_tmp; __rb_parent = *__rb_link; vma_tmp = rb_entry(__rb_parent, struct vm_area_struct, vm_rb); if (vma_tmp->vm_end > addr) { /* Fail if an existing vma overlaps the area */ if (vma_tmp->vm_start < end) return -ENOMEM; __rb_link = &__rb_parent->rb_left; } else { rb_prev = __rb_parent; __rb_link = &__rb_parent->rb_right; } } *pprev = NULL; if (rb_prev) *pprev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); *rb_link = __rb_link; *rb_parent = __rb_parent; return 0; } /* * vma_next() - Get the next VMA. * @mm: The mm_struct. * @vma: The current vma. * * If @vma is NULL, return the first vma in the mm. * * Returns: The next VMA after @vma. */ static inline struct vm_area_struct *vma_next(struct mm_struct *mm, struct vm_area_struct *vma) { if (!vma) return mm->mmap; return vma->vm_next; } /* * munmap_vma_range() - munmap VMAs that overlap a range. * @mm: The mm struct * @start: The start of the range. * @len: The length of the range. * @pprev: pointer to the pointer that will be set to previous vm_area_struct * @rb_link: the rb_node * @rb_parent: the parent rb_node * * Find all the vm_area_struct that overlap from @start to * @end and munmap them. Set @pprev to the previous vm_area_struct. * * Returns: -ENOMEM on munmap failure or 0 on success. */ static inline int munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, struct vm_area_struct **pprev, struct rb_node ***link, struct rb_node **parent, struct list_head *uf) { while (find_vma_links(mm, start, start + len, pprev, link, parent)) if (do_munmap(mm, start, len, uf)) return -ENOMEM; return 0; } static unsigned long count_vma_pages_range(struct mm_struct *mm, unsigned long addr, unsigned long end) { unsigned long nr_pages = 0; struct vm_area_struct *vma; /* Find first overlaping mapping */ vma = find_vma_intersection(mm, addr, end); if (!vma) return 0; nr_pages = (min(end, vma->vm_end) - max(addr, vma->vm_start)) >> PAGE_SHIFT; /* Iterate over the rest of the overlaps */ for (vma = vma->vm_next; vma; vma = vma->vm_next) { unsigned long overlap_len; if (vma->vm_start > end) break; overlap_len = min(end, vma->vm_end) - vma->vm_start; nr_pages += overlap_len >> PAGE_SHIFT; } return nr_pages; } void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma, struct rb_node **rb_link, struct rb_node *rb_parent) { /* Update tracking information for the gap following the new vma. */ if (vma->vm_next) vma_gap_update(vma->vm_next); else mm->highest_vm_end = vm_end_gap(vma); /* * vma->vm_prev wasn't known when we followed the rbtree to find the * correct insertion point for that vma. As a result, we could not * update the vma vm_rb parents rb_subtree_gap values on the way down. * So, we first insert the vma with a zero rb_subtree_gap value * (to be consistent with what we did on the way down), and then * immediately update the gap to the correct value. Finally we * rebalance the rbtree after all augmented values have been set. */ rb_link_node(&vma->vm_rb, rb_parent, rb_link); vma->rb_subtree_gap = 0; vma_gap_update(vma); vma_rb_insert(vma, &mm->mm_rb); } static void __vma_link_file(struct vm_area_struct *vma) { struct file *file; file = vma->vm_file; if (file) { struct address_space *mapping = file->f_mapping; if (vma->vm_flags & VM_DENYWRITE) put_write_access(file_inode(file)); if (vma->vm_flags & VM_SHARED) mapping_allow_writable(mapping); flush_dcache_mmap_lock(mapping); vma_interval_tree_insert(vma, &mapping->i_mmap); flush_dcache_mmap_unlock(mapping); } } static void __vma_link(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, struct rb_node **rb_link, struct rb_node *rb_parent) { __vma_link_list(mm, vma, prev); __vma_link_rb(mm, vma, rb_link, rb_parent); } static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, struct rb_node **rb_link, struct rb_node *rb_parent) { struct address_space *mapping = NULL; if (vma->vm_file) { mapping = vma->vm_file->f_mapping; i_mmap_lock_write(mapping); } __vma_link(mm, vma, prev, rb_link, rb_parent); __vma_link_file(vma); if (mapping) i_mmap_unlock_write(mapping); mm->map_count++; validate_mm(mm); } /* * Helper for vma_adjust() in the split_vma insert case: insert a vma into the * mm's list and rbtree. It has already been inserted into the interval tree. */ static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma) { struct vm_area_struct *prev; struct rb_node **rb_link, *rb_parent; if (find_vma_links(mm, vma->vm_start, vma->vm_end, &prev, &rb_link, &rb_parent)) BUG(); __vma_link(mm, vma, prev, rb_link, rb_parent); mm->map_count++; } static __always_inline void __vma_unlink(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *ignore) { vma_rb_erase_ignore(vma, &mm->mm_rb, ignore); __vma_unlink_list(mm, vma); /* Kill the cache */ vmacache_invalidate(mm); } /* * We cannot adjust vm_start, vm_end, vm_pgoff fields of a vma that * is already present in an i_mmap tree without adjusting the tree. * The following helper function should be used when such adjustments * are necessary. The "insert" vma (if any) is to be inserted * before we drop the necessary locks. */ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert, struct vm_area_struct *expand) { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *next = vma->vm_next, *orig_vma = vma; struct address_space *mapping = NULL; struct rb_root_cached *root = NULL; struct anon_vma *anon_vma = NULL; struct file *file = vma->vm_file; bool start_changed = false, end_changed = false; long adjust_next = 0; int remove_next = 0; if (next && !insert) { struct vm_area_struct *exporter = NULL, *importer = NULL; if (end >= next->vm_end) { /* * vma expands, overlapping all the next, and * perhaps the one after too (mprotect case 6). * The only other cases that gets here are * case 1, case 7 and case 8. */ if (next == expand) { /* * The only case where we don't expand "vma" * and we expand "next" instead is case 8. */ VM_WARN_ON(end != next->vm_end); /* * remove_next == 3 means we're * removing "vma" and that to do so we * swapped "vma" and "next". */ remove_next = 3; VM_WARN_ON(file != next->vm_file); swap(vma, next); } else { VM_WARN_ON(expand != vma); /* * case 1, 6, 7, remove_next == 2 is case 6, * remove_next == 1 is case 1 or 7. */ remove_next = 1 + (end > next->vm_end); VM_WARN_ON(remove_next == 2 && end != next->vm_next->vm_end); /* trim end to next, for case 6 first pass */ end = next->vm_end; } exporter = next; importer = vma; /* * If next doesn't have anon_vma, import from vma after * next, if the vma overlaps with it. */ if (remove_next == 2 && !next->anon_vma) exporter = next->vm_next; } else if (end > next->vm_start) { /* * vma expands, overlapping part of the next: * mprotect case 5 shifting the boundary up. */ adjust_next = (end - next->vm_start); exporter = next; importer = vma; VM_WARN_ON(expand != importer); } else if (end < vma->vm_end) { /* * vma shrinks, and !insert tells it's not * split_vma inserting another: so it must be * mprotect case 4 shifting the boundary down. */ adjust_next = -(vma->vm_end - end); exporter = vma; importer = next; VM_WARN_ON(expand != importer); } /* * Easily overlooked: when mprotect shifts the boundary, * make sure the expanding vma has anon_vma set if the * shrinking vma had, to cover any anon pages imported. */ if (exporter && exporter->anon_vma && !importer->anon_vma) { int error; importer->anon_vma = exporter->anon_vma; error = anon_vma_clone(importer, exporter); if (error) return error; } } again: vma_adjust_trans_huge(orig_vma, start, end, adjust_next); if (file) { mapping = file->f_mapping; root = &mapping->i_mmap; uprobe_munmap(vma, vma->vm_start, vma->vm_end); if (adjust_next) uprobe_munmap(next, next->vm_start, next->vm_end); i_mmap_lock_write(mapping); if (insert) { /* * Put into interval tree now, so instantiated pages * are visible to arm/parisc __flush_dcache_page * throughout; but we cannot insert into address * space until vma start or end is updated. */ __vma_link_file(insert); } } anon_vma = vma->anon_vma; if (!anon_vma && adjust_next) anon_vma = next->anon_vma; if (anon_vma) { VM_WARN_ON(adjust_next && next->anon_vma && anon_vma != next->anon_vma); anon_vma_lock_write(anon_vma); anon_vma_interval_tree_pre_update_vma(vma); if (adjust_next) anon_vma_interval_tree_pre_update_vma(next); } if (file) { flush_dcache_mmap_lock(mapping); vma_interval_tree_remove(vma, root); if (adjust_next) vma_interval_tree_remove(next, root); } if (start != vma->vm_start) { vma->vm_start = start; start_changed = true; } if (end != vma->vm_end) { vma->vm_end = end; end_changed = true; } vma->vm_pgoff = pgoff; if (adjust_next) { next->vm_start += adjust_next; next->vm_pgoff += adjust_next >> PAGE_SHIFT; } if (file) { if (adjust_next) vma_interval_tree_insert(next, root); vma_interval_tree_insert(vma, root); flush_dcache_mmap_unlock(mapping); } if (remove_next) { /* * vma_merge has merged next into vma, and needs * us to remove next before dropping the locks. */ if (remove_next != 3) __vma_unlink(mm, next, next); else /* * vma is not before next if they've been * swapped. * * pre-swap() next->vm_start was reduced so * tell validate_mm_rb to ignore pre-swap() * "next" (which is stored in post-swap() * "vma"). */ __vma_unlink(mm, next, vma); if (file) __remove_shared_vm_struct(next, file, mapping); } else if (insert) { /* * split_vma has split insert from vma, and needs * us to insert it before dropping the locks * (it may either follow vma or precede it). */ __insert_vm_struct(mm, insert); } else { if (start_changed) vma_gap_update(vma); if (end_changed) { if (!next) mm->highest_vm_end = vm_end_gap(vma); else if (!adjust_next) vma_gap_update(next); } } if (anon_vma) { anon_vma_interval_tree_post_update_vma(vma); if (adjust_next) anon_vma_interval_tree_post_update_vma(next); anon_vma_unlock_write(anon_vma); } if (file) { i_mmap_unlock_write(mapping); uprobe_mmap(vma); if (adjust_next) uprobe_mmap(next); } if (remove_next) { if (file) { uprobe_munmap(next, next->vm_start, next->vm_end); fput(file); } if (next->anon_vma) anon_vma_merge(vma, next); mm->map_count--; mpol_put(vma_policy(next)); vm_area_free(next); /* * In mprotect's case 6 (see comments on vma_merge), * we must remove another next too. It would clutter * up the code too much to do both in one go. */ if (remove_next != 3) { /* * If "next" was removed and vma->vm_end was * expanded (up) over it, in turn * "next->vm_prev->vm_end" changed and the * "vma->vm_next" gap must be updated. */ next = vma->vm_next; } else { /* * For the scope of the comment "next" and * "vma" considered pre-swap(): if "vma" was * removed, next->vm_start was expanded (down) * over it and the "next" gap must be updated. * Because of the swap() the post-swap() "vma" * actually points to pre-swap() "next" * (post-swap() "next" as opposed is now a * dangling pointer). */ next = vma; } if (remove_next == 2) { remove_next = 1; end = next->vm_end; goto again; } else if (next) vma_gap_update(next); else { /* * If remove_next == 2 we obviously can't * reach this path. * * If remove_next == 3 we can't reach this * path because pre-swap() next is always not * NULL. pre-swap() "next" is not being * removed and its next->vm_end is not altered * (and furthermore "end" already matches * next->vm_end in remove_next == 3). * * We reach this only in the remove_next == 1 * case if the "next" vma that was removed was * the highest vma of the mm. However in such * case next->vm_end == "end" and the extended * "vma" has vma->vm_end == next->vm_end so * mm->highest_vm_end doesn't need any update * in remove_next == 1 case. */ VM_WARN_ON(mm->highest_vm_end != vm_end_gap(vma)); } } if (insert && file) uprobe_mmap(insert); validate_mm(mm); return 0; } /* * If the vma has a ->close operation then the driver probably needs to release * per-vma resources, so we don't attempt to merge those. */ static inline int is_mergeable_vma(struct vm_area_struct *vma, struct file *file, unsigned long vm_flags, struct vm_userfaultfd_ctx vm_userfaultfd_ctx) { /* * VM_SOFTDIRTY should not prevent from VMA merging, if we * match the flags but dirty bit -- the caller should mark * merged VMA as dirty. If dirty bit won't be excluded from * comparison, we increase pressure on the memory system forcing * the kernel to generate new VMAs when old one could be * extended instead. */ if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY) return 0; if (vma->vm_file != file) return 0; if (vma->vm_ops && vma->vm_ops->close) return 0; if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx)) return 0; return 1; } static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1, struct anon_vma *anon_vma2, struct vm_area_struct *vma) { /* * The list_is_singular() test is to avoid merging VMA cloned from * parents. This can improve scalability caused by anon_vma lock. */ if ((!anon_vma1 || !anon_vma2) && (!vma || list_is_singular(&vma->anon_vma_chain))) return 1; return anon_vma1 == anon_vma2; } /* * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff) * in front of (at a lower virtual address and file offset than) the vma. * * We cannot merge two vmas if they have differently assigned (non-NULL) * anon_vmas, nor if same anon_vma is assigned but offsets incompatible. * * We don't check here for the merged mmap wrapping around the end of pagecache * indices (16TB on ia32) because do_mmap() does not permit mmap's which * wrap, nor mmaps which cover the final page at index -1UL. */ static int can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags, struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx) { if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) && is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) { if (vma->vm_pgoff == vm_pgoff) return 1; } return 0; } /* * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff) * beyond (at a higher virtual address and file offset than) the vma. * * We cannot merge two vmas if they have differently assigned (non-NULL) * anon_vmas, nor if same anon_vma is assigned but offsets incompatible. */ static int can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags, struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx) { if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) && is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) { pgoff_t vm_pglen; vm_pglen = vma_pages(vma); if (vma->vm_pgoff + vm_pglen == vm_pgoff) return 1; } return 0; } /* * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out * whether that can be merged with its predecessor or its successor. * Or both (it neatly fills a hole). * * In most cases - when called for mmap, brk or mremap - [addr,end) is * certain not to be mapped by the time vma_merge is called; but when * called for mprotect, it is certain to be already mapped (either at * an offset within prev, or at the start of next), and the flags of * this area are about to be changed to vm_flags - and the no-change * case has already been eliminated. * * The following mprotect cases have to be considered, where AAAA is * the area passed down from mprotect_fixup, never extending beyond one * vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after: * * AAAA AAAA AAAA * PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN * cannot merge might become might become * PPNNNNNNNNNN PPPPPPPPPPNN * mmap, brk or case 4 below case 5 below * mremap move: * AAAA AAAA * PPPP NNNN PPPPNNNNXXXX * might become might become * PPPPPPPPPPPP 1 or PPPPPPPPPPPP 6 or * PPPPPPPPNNNN 2 or PPPPPPPPXXXX 7 or * PPPPNNNNNNNN 3 PPPPXXXXXXXX 8 * * It is important for case 8 that the vma NNNN overlapping the * region AAAA is never going to extended over XXXX. Instead XXXX must * be extended in region AAAA and NNNN must be removed. This way in * all cases where vma_merge succeeds, the moment vma_adjust drops the * rmap_locks, the properties of the merged vma will be already * correct for the whole merged range. Some of those properties like * vm_page_prot/vm_flags may be accessed by rmap_walks and they must * be correct for the whole merged range immediately after the * rmap_locks are released. Otherwise if XXXX would be removed and * NNNN would be extended over the XXXX range, remove_migration_ptes * or other rmap walkers (if working on addresses beyond the "end" * parameter) may establish ptes with the wrong permissions of NNNN * instead of the right permissions of XXXX. */ struct vm_area_struct *vma_merge(struct mm_struct *mm, struct vm_area_struct *prev, unsigned long addr, unsigned long end, unsigned long vm_flags, struct anon_vma *anon_vma, struct file *file, pgoff_t pgoff, struct mempolicy *policy, struct vm_userfaultfd_ctx vm_userfaultfd_ctx) { pgoff_t pglen = (end - addr) >> PAGE_SHIFT; struct vm_area_struct *area, *next; int err; /* * We later require that vma->vm_flags == vm_flags, * so this tests vma->vm_flags & VM_SPECIAL, too. */ if (vm_flags & VM_SPECIAL) return NULL; next = vma_next(mm, prev); area = next; if (area && area->vm_end == end) /* cases 6, 7, 8 */ next = next->vm_next; /* verify some invariant that must be enforced by the caller */ VM_WARN_ON(prev && addr <= prev->vm_start); VM_WARN_ON(area && end > area->vm_end); VM_WARN_ON(addr >= end); /* * Can it merge with the predecessor? */ if (prev && prev->vm_end == addr && mpol_equal(vma_policy(prev), policy) && can_vma_merge_after(prev, vm_flags, anon_vma, file, pgoff, vm_userfaultfd_ctx)) { /* * OK, it can. Can we now merge in the successor as well? */ if (next && end == next->vm_start && mpol_equal(policy, vma_policy(next)) && can_vma_merge_before(next, vm_flags, anon_vma, file, pgoff+pglen, vm_userfaultfd_ctx) && is_mergeable_anon_vma(prev->anon_vma, next->anon_vma, NULL)) { /* cases 1, 6 */ err = __vma_adjust(prev, prev->vm_start, next->vm_end, prev->vm_pgoff, NULL, prev); } else /* cases 2, 5, 7 */ err = __vma_adjust(prev, prev->vm_start, end, prev->vm_pgoff, NULL, prev); if (err) return NULL; khugepaged_enter_vma_merge(prev, vm_flags); return prev; } /* * Can this new request be merged in front of next? */ if (next && end == next->vm_start && mpol_equal(policy, vma_policy(next)) && can_vma_merge_before(next, vm_flags, anon_vma, file, pgoff+pglen, vm_userfaultfd_ctx)) { if (prev && addr < prev->vm_end) /* case 4 */ err = __vma_adjust(prev, prev->vm_start, addr, prev->vm_pgoff, NULL, next); else { /* cases 3, 8 */ err = __vma_adjust(area, addr, next->vm_end, next->vm_pgoff - pglen, NULL, next); /* * In case 3 area is already equal to next and * this is a noop, but in case 8 "area" has * been removed and next was expanded over it. */ area = next; } if (err) return NULL; khugepaged_enter_vma_merge(area, vm_flags); return area; } return NULL; } /* * Rough compatibility check to quickly see if it's even worth looking * at sharing an anon_vma. * * They need to have the same vm_file, and the flags can only differ * in things that mprotect may change. * * NOTE! The fact that we share an anon_vma doesn't _have_ to mean that * we can merge the two vma's. For example, we refuse to merge a vma if * there is a vm_ops->close() function, because that indicates that the * driver is doing some kind of reference counting. But that doesn't * really matter for the anon_vma sharing case. */ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *b) { return a->vm_end == b->vm_start && mpol_equal(vma_policy(a), vma_policy(b)) && a->vm_file == b->vm_file && !((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS | VM_SOFTDIRTY)) && b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); } /* * Do some basic sanity checking to see if we can re-use the anon_vma * from 'old'. The 'a'/'b' vma's are in VM order - one of them will be * the same as 'old', the other will be the new one that is trying * to share the anon_vma. * * NOTE! This runs with mm_sem held for reading, so it is possible that * the anon_vma of 'old' is concurrently in the process of being set up * by another page fault trying to merge _that_. But that's ok: if it * is being set up, that automatically means that it will be a singleton * acceptable for merging, so we can do all of this optimistically. But * we do that READ_ONCE() to make sure that we never re-load the pointer. * * IOW: that the "list_is_singular()" test on the anon_vma_chain only * matters for the 'stable anon_vma' case (ie the thing we want to avoid * is to return an anon_vma that is "complex" due to having gone through * a fork). * * We also make sure that the two vma's are compatible (adjacent, * and with the same memory policies). That's all stable, even with just * a read lock on the mm_sem. */ static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_area_struct *a, struct vm_area_struct *b) { if (anon_vma_compatible(a, b)) { struct anon_vma *anon_vma = READ_ONCE(old->anon_vma); if (anon_vma && list_is_singular(&old->anon_vma_chain)) return anon_vma; } return NULL; } /* * find_mergeable_anon_vma is used by anon_vma_prepare, to check * neighbouring vmas for a suitable anon_vma, before it goes off * to allocate a new anon_vma. It checks because a repetitive * sequence of mprotects and faults may otherwise lead to distinct * anon_vmas being allocated, preventing vma merge in subsequent * mprotect. */ struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) { struct anon_vma *anon_vma = NULL; /* Try next first. */ if (vma->vm_next) { anon_vma = reusable_anon_vma(vma->vm_next, vma, vma->vm_next); if (anon_vma) return anon_vma; } /* Try prev next. */ if (vma->vm_prev) anon_vma = reusable_anon_vma(vma->vm_prev, vma->vm_prev, vma); /* * We might reach here with anon_vma == NULL if we can't find * any reusable anon_vma. * There's no absolute need to look only at touching neighbours: * we could search further afield for "compatible" anon_vmas. * But it would probably just be a waste of time searching, * or lead to too many vmas hanging off the same anon_vma. * We're trying to allow mprotect remerging later on, * not trying to minimize memory used for anon_vmas. */ return anon_vma; } /* * If a hint addr is less than mmap_min_addr change hint to be as * low as possible but still greater than mmap_min_addr */ static inline unsigned long round_hint_to_min(unsigned long hint) { hint &= PAGE_MASK; if (((void *)hint != NULL) && (hint < mmap_min_addr)) return PAGE_ALIGN(mmap_min_addr); return hint; } static inline int mlock_future_check(struct mm_struct *mm, unsigned long flags, unsigned long len) { unsigned long locked, lock_limit; /* mlock MCL_FUTURE? */ if (flags & VM_LOCKED) { locked = len >> PAGE_SHIFT; locked += mm->locked_vm; lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; if (locked > lock_limit && !capable(CAP_IPC_LOCK)) return -EAGAIN; } return 0; } static inline u64 file_mmap_size_max(struct file *file, struct inode *inode) { if (S_ISREG(inode->i_mode)) return MAX_LFS_FILESIZE; if (S_ISBLK(inode->i_mode)) return MAX_LFS_FILESIZE; if (S_ISSOCK(inode->i_mode)) return MAX_LFS_FILESIZE; /* Special "we do even unsigned file positions" case */ if (file->f_mode & FMODE_UNSIGNED_OFFSET) return 0; /* Yes, random drivers might want more. But I'm tired of buggy drivers */ return ULONG_MAX; } static inline bool file_mmap_ok(struct file *file, struct inode *inode, unsigned long pgoff, unsigned long len) { u64 maxsize = file_mmap_size_max(file, inode); if (maxsize && len > maxsize) return false; maxsize -= len; if (pgoff > maxsize >> PAGE_SHIFT) return false; return true; } /* * The caller must write-lock current->mm->mmap_lock. */ unsigned long do_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long pgoff, unsigned long *populate, struct list_head *uf) { struct mm_struct *mm = current->mm; vm_flags_t vm_flags; int pkey = 0; *populate = 0; if (!len) return -EINVAL; /* * Does the application expect PROT_READ to imply PROT_EXEC? * * (the exception is when the underlying filesystem is noexec * mounted, in which case we dont add PROT_EXEC.) */ if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) if (!(file && path_noexec(&file->f_path))) prot |= PROT_EXEC; /* force arch specific MAP_FIXED handling in get_unmapped_area */ if (flags & MAP_FIXED_NOREPLACE) flags |= MAP_FIXED; if (!(flags & MAP_FIXED)) addr = round_hint_to_min(addr); /* Careful about overflows.. */ len = PAGE_ALIGN(len); if (!len) return -ENOMEM; /* offset overflow? */ if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) return -EOVERFLOW; /* Too many mappings? */ if (mm->map_count > sysctl_max_map_count) return -ENOMEM; /* Obtain the address to map to. we verify (or select) it and ensure * that it represents a valid section of the address space. */ addr = get_unmapped_area(file, addr, len, pgoff, flags); if (IS_ERR_VALUE(addr)) return addr; if (flags & MAP_FIXED_NOREPLACE) { struct vm_area_struct *vma = find_vma(mm, addr); if (vma && vma->vm_start < addr + len) return -EEXIST; } if (prot == PROT_EXEC) { pkey = execute_only_pkey(mm); if (pkey < 0) pkey = 0; } /* Do simple checking here so the lower-level routines won't have * to. we assume access permissions have been handled by the open * of the memory object, so we don't do any here. */ vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; if (flags & MAP_LOCKED) if (!can_do_mlock()) return -EPERM; if (mlock_future_check(mm, vm_flags, len)) return -EAGAIN; if (file) { struct inode *inode = file_inode(file); unsigned long flags_mask; if (!file_mmap_ok(file, inode, pgoff, len)) return -EOVERFLOW; flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags; switch (flags & MAP_TYPE) { case MAP_SHARED: /* * Force use of MAP_SHARED_VALIDATE with non-legacy * flags. E.g. MAP_SYNC is dangerous to use with * MAP_SHARED as you don't know which consistency model * you will get. We silently ignore unsupported flags * with MAP_SHARED to preserve backward compatibility. */ flags &= LEGACY_MAP_MASK; fallthrough; case MAP_SHARED_VALIDATE: if (flags & ~flags_mask) return -EOPNOTSUPP; if (prot & PROT_WRITE) { if (!(file->f_mode & FMODE_WRITE)) return -EACCES; if (IS_SWAPFILE(file->f_mapping->host)) return -ETXTBSY; } /* * Make sure we don't allow writing to an append-only * file.. */ if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE)) return -EACCES; /* * Make sure there are no mandatory locks on the file. */ if (locks_verify_locked(file)) return -EAGAIN; vm_flags |= VM_SHARED | VM_MAYSHARE; if (!(file->f_mode & FMODE_WRITE)) vm_flags &= ~(VM_MAYWRITE | VM_SHARED); fallthrough; case MAP_PRIVATE: if (!(file->f_mode & FMODE_READ)) return -EACCES; if (path_noexec(&file->f_path)) { if (vm_flags & VM_EXEC) return -EPERM; vm_flags &= ~VM_MAYEXEC; } if (!file->f_op->mmap) return -ENODEV; if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP)) return -EINVAL; break; default: return -EINVAL; } } else { switch (flags & MAP_TYPE) { case MAP_SHARED: if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP)) return -EINVAL; /* * Ignore pgoff. */ pgoff = 0; vm_flags |= VM_SHARED | VM_MAYSHARE; break; case MAP_PRIVATE: /* * Set pgoff according to addr for anon_vma. */ pgoff = addr >> PAGE_SHIFT; break; default: return -EINVAL; } } /* * Set 'VM_NORESERVE' if we should not account for the * memory use of this mapping. */ if (flags & MAP_NORESERVE) { /* We honor MAP_NORESERVE if allowed to overcommit */ if (sysctl_overcommit_memory != OVERCOMMIT_NEVER) vm_flags |= VM_NORESERVE; /* hugetlb applies strict overcommit unless MAP_NORESERVE */ if (file && is_file_hugepages(file)) vm_flags |= VM_NORESERVE; } addr = mmap_region(file, addr, len, vm_flags, pgoff, uf); if (!IS_ERR_VALUE(addr) && ((vm_flags & VM_LOCKED) || (flags & (MAP_POPULATE | MAP_NONBLOCK)) == MAP_POPULATE)) *populate = len; return addr; } unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, unsigned long pgoff) { struct file *file = NULL; unsigned long retval; if (!(flags & MAP_ANONYMOUS)) { audit_mmap_fd(fd, flags); file = fget(fd); if (!file) return -EBADF; if (is_file_hugepages(file)) { len = ALIGN(len, huge_page_size(hstate_file(file))); } else if (unlikely(flags & MAP_HUGETLB)) { retval = -EINVAL; goto out_fput; } } else if (flags & MAP_HUGETLB) { struct user_struct *user = NULL; struct hstate *hs; hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK); if (!hs) return -EINVAL; len = ALIGN(len, huge_page_size(hs)); /* * VM_NORESERVE is used because the reservations will be * taken when vm_ops->mmap() is called * A dummy user value is used because we are not locking * memory so no accounting is necessary */ file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE, &user, HUGETLB_ANONHUGE_INODE, (flags >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK); if (IS_ERR(file)) return PTR_ERR(file); } flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: if (file) fput(file); return retval; } SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags, unsigned long, fd, unsigned long, pgoff) { return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); } #ifdef __ARCH_WANT_SYS_OLD_MMAP struct mmap_arg_struct { unsigned long addr; unsigned long len; unsigned long prot; unsigned long flags; unsigned long fd; unsigned long offset; }; SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) { struct mmap_arg_struct a; if (copy_from_user(&a, arg, sizeof(a))) return -EFAULT; if (offset_in_page(a.offset)) return -EINVAL; return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT); } #endif /* __ARCH_WANT_SYS_OLD_MMAP */ /* * Some shared mappings will want the pages marked read-only * to track write events. If so, we'll downgrade vm_page_prot * to the private version (using protection_map[] without the * VM_SHARED bit). */ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot) { vm_flags_t vm_flags = vma->vm_flags; const struct vm_operations_struct *vm_ops = vma->vm_ops; /* If it was private or non-writable, the write bit is already clear */ if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED))) return 0; /* The backer wishes to know when pages are first written to? */ if (vm_ops && (vm_ops->page_mkwrite || vm_ops->pfn_mkwrite)) return 1; /* The open routine did something to the protections that pgprot_modify * won't preserve? */ if (pgprot_val(vm_page_prot) != pgprot_val(vm_pgprot_modify(vm_page_prot, vm_flags))) return 0; /* Do we need to track softdirty? */ if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY)) return 1; /* Specialty mapping? */ if (vm_flags & VM_PFNMAP) return 0; /* Can the mapping track the dirty pages? */ return vma->vm_file && vma->vm_file->f_mapping && mapping_can_writeback(vma->vm_file->f_mapping); } /* * We account for memory if it's a private writeable mapping, * not hugepages and VM_NORESERVE wasn't set. */ static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags) { /* * hugetlb has its own accounting separate from the core VM * VM_HUGETLB may not be set yet so we cannot check for that flag. */ if (file && is_file_hugepages(file)) return 0; return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE; } unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long len, vm_flags_t vm_flags, unsigned long pgoff, struct list_head *uf) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev, *merge; int error; struct rb_node **rb_link, *rb_parent; unsigned long charged = 0; /* Check against address space limit. */ if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) { unsigned long nr_pages; /* * MAP_FIXED may remove pages of mappings that intersects with * requested mapping. Account for the pages it would unmap. */ nr_pages = count_vma_pages_range(mm, addr, addr + len); if (!may_expand_vm(mm, vm_flags, (len >> PAGE_SHIFT) - nr_pages)) return -ENOMEM; } /* Clear old maps, set up prev, rb_link, rb_parent, and uf */ if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf)) return -ENOMEM; /* * Private writable mapping: check memory availability */ if (accountable_mapping(file, vm_flags)) { charged = len >> PAGE_SHIFT; if (security_vm_enough_memory_mm(mm, charged)) return -ENOMEM; vm_flags |= VM_ACCOUNT; } /* * Can we just expand an old mapping? */ vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX); if (vma) goto out; /* * Determine the object being mapped and call the appropriate * specific mapper. the address has already been validated, but * not unmapped, but the maps are removed from the list. */ vma = vm_area_alloc(mm); if (!vma) { error = -ENOMEM; goto unacct_error; } vma->vm_start = addr; vma->vm_end = addr + len; vma->vm_flags = vm_flags; vma->vm_page_prot = vm_get_page_prot(vm_flags); vma->vm_pgoff = pgoff; if (file) { if (vm_flags & VM_DENYWRITE) { error = deny_write_access(file); if (error) goto free_vma; } if (vm_flags & VM_SHARED) { error = mapping_map_writable(file->f_mapping); if (error) goto allow_write_and_free_vma; } /* ->mmap() can change vma->vm_file, but must guarantee that * vma_link() below can deny write-access if VM_DENYWRITE is set * and map writably if VM_SHARED is set. This usually means the * new file must not have been exposed to user-space, yet. */ vma->vm_file = get_file(file); error = call_mmap(file, vma); if (error) goto unmap_and_free_vma; /* Can addr have changed?? * * Answer: Yes, several device drivers can do it in their * f_op->mmap method. -DaveM * Bug: If addr is changed, prev, rb_link, rb_parent should * be updated for vma_link() */ WARN_ON_ONCE(addr != vma->vm_start); addr = vma->vm_start; /* If vm_flags changed after call_mmap(), we should try merge vma again * as we may succeed this time. */ if (unlikely(vm_flags != vma->vm_flags && prev)) { merge = vma_merge(mm, prev, vma->vm_start, vma->vm_end, vma->vm_flags, NULL, vma->vm_file, vma->vm_pgoff, NULL, NULL_VM_UFFD_CTX); if (merge) { /* ->mmap() can change vma->vm_file and fput the original file. So * fput the vma->vm_file here or we would add an extra fput for file * and cause general protection fault ultimately. */ fput(vma->vm_file); vm_area_free(vma); vma = merge; /* Update vm_flags to pick up the change. */ vm_flags = vma->vm_flags; goto unmap_writable; } } vm_flags = vma->vm_flags; } else if (vm_flags & VM_SHARED) { error = shmem_zero_setup(vma); if (error) goto free_vma; } else { vma_set_anonymous(vma); } /* Allow architectures to sanity-check the vm_flags */ if (!arch_validate_flags(vma->vm_flags)) { error = -EINVAL; if (file) goto unmap_and_free_vma; else goto free_vma; } vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ if (file) { unmap_writable: if (vm_flags & VM_SHARED) mapping_unmap_writable(file->f_mapping); if (vm_flags & VM_DENYWRITE) allow_write_access(file); } file = vma->vm_file; out: perf_event_mmap(vma); vm_stat_account(mm, vm_flags, len >> PAGE_SHIFT); if (vm_flags & VM_LOCKED) { if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) || is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) vma->vm_flags &= VM_LOCKED_CLEAR_MASK; else mm->locked_vm += (len >> PAGE_SHIFT); } if (file) uprobe_mmap(vma); /* * New (or expanded) vma always get soft dirty status. * Otherwise user-space soft-dirty page tracker won't * be able to distinguish situation when vma area unmapped, * then new mapped in-place (which must be aimed as * a completely new data area). */ vma->vm_flags |= VM_SOFTDIRTY; vma_set_page_prot(vma); return addr; unmap_and_free_vma: vma->vm_file = NULL; fput(file); /* Undo any partial mapping done by a device driver. */ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); charged = 0; if (vm_flags & VM_SHARED) mapping_unmap_writable(file->f_mapping); allow_write_and_free_vma: if (vm_flags & VM_DENYWRITE) allow_write_access(file); free_vma: vm_area_free(vma); unacct_error: if (charged) vm_unacct_memory(charged); return error; } static unsigned long unmapped_area(struct vm_unmapped_area_info *info) { /* * We implement the search by looking for an rbtree node that * immediately follows a suitable gap. That is, * - gap_start = vma->vm_prev->vm_end <= info->high_limit - length; * - gap_end = vma->vm_start >= info->low_limit + length; * - gap_end - gap_start >= length */ struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long length, low_limit, high_limit, gap_start, gap_end; /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; if (length < info->length) return -ENOMEM; /* Adjust search limits by the desired length */ if (info->high_limit < length) return -ENOMEM; high_limit = info->high_limit - length; if (info->low_limit > high_limit) return -ENOMEM; low_limit = info->low_limit + length; /* Check if rbtree root looks promising */ if (RB_EMPTY_ROOT(&mm->mm_rb)) goto check_highest; vma = rb_entry(mm->mm_rb.rb_node, struct vm_area_struct, vm_rb); if (vma->rb_subtree_gap < length) goto check_highest; while (true) { /* Visit left subtree if it looks promising */ gap_end = vm_start_gap(vma); if (gap_end >= low_limit && vma->vm_rb.rb_left) { struct vm_area_struct *left = rb_entry(vma->vm_rb.rb_left, struct vm_area_struct, vm_rb); if (left->rb_subtree_gap >= length) { vma = left; continue; } } gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; check_current: /* Check if current node has a suitable gap */ if (gap_start > high_limit) return -ENOMEM; if (gap_end >= low_limit && gap_end > gap_start && gap_end - gap_start >= length) goto found; /* Visit right subtree if it looks promising */ if (vma->vm_rb.rb_right) { struct vm_area_struct *right = rb_entry(vma->vm_rb.rb_right, struct vm_area_struct, vm_rb); if (right->rb_subtree_gap >= length) { vma = right; continue; } } /* Go back up the rbtree to find next candidate node */ while (true) { struct rb_node *prev = &vma->vm_rb; if (!rb_parent(prev)) goto check_highest; vma = rb_entry(rb_parent(prev), struct vm_area_struct, vm_rb); if (prev == vma->vm_rb.rb_left) { gap_start = vm_end_gap(vma->vm_prev); gap_end = vm_start_gap(vma); goto check_current; } } } check_highest: /* Check highest gap, which does not precede any rbtree node */ gap_start = mm->highest_vm_end; gap_end = ULONG_MAX; /* Only for VM_BUG_ON below */ if (gap_start > high_limit) return -ENOMEM; found: /* We found a suitable gap. Clip it with the original low_limit. */ if (gap_start < info->low_limit) gap_start = info->low_limit; /* Adjust gap address to the desired alignment */ gap_start += (info->align_offset - gap_start) & info->align_mask; VM_BUG_ON(gap_start + info->length > info->high_limit); VM_BUG_ON(gap_start + info->length > gap_end); return gap_start; } static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long length, low_limit, high_limit, gap_start, gap_end; /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; if (length < info->length) return -ENOMEM; /* * Adjust search limits by the desired length. * See implementation comment at top of unmapped_area(). */ gap_end = info->high_limit; if (gap_end < length) return -ENOMEM; high_limit = gap_end - length; if (info->low_limit > high_limit) return -ENOMEM; low_limit = info->low_limit + length; /* Check highest gap, which does not precede any rbtree node */ gap_start = mm->highest_vm_end; if (gap_start <= high_limit) goto found_highest; /* Check if rbtree root looks promising */ if (RB_EMPTY_ROOT(&mm->mm_rb)) return -ENOMEM; vma = rb_entry(mm->mm_rb.rb_node, struct vm_area_struct, vm_rb); if (vma->rb_subtree_gap < length) return -ENOMEM; while (true) { /* Visit right subtree if it looks promising */ gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; if (gap_start <= high_limit && vma->vm_rb.rb_right) { struct vm_area_struct *right = rb_entry(vma->vm_rb.rb_right, struct vm_area_struct, vm_rb); if (right->rb_subtree_gap >= length) { vma = right; continue; } } check_current: /* Check if current node has a suitable gap */ gap_end = vm_start_gap(vma); if (gap_end < low_limit) return -ENOMEM; if (gap_start <= high_limit && gap_end > gap_start && gap_end - gap_start >= length) goto found; /* Visit left subtree if it looks promising */ if (vma->vm_rb.rb_left) { struct vm_area_struct *left = rb_entry(vma->vm_rb.rb_left, struct vm_area_struct, vm_rb); if (left->rb_subtree_gap >= length) { vma = left; continue; } } /* Go back up the rbtree to find next candidate node */ while (true) { struct rb_node *prev = &vma->vm_rb; if (!rb_parent(prev)) return -ENOMEM; vma = rb_entry(rb_parent(prev), struct vm_area_struct, vm_rb); if (prev == vma->vm_rb.rb_right) { gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; goto check_current; } } } found: /* We found a suitable gap. Clip it with the original high_limit. */ if (gap_end > info->high_limit) gap_end = info->high_limit; found_highest: /* Compute highest gap address at the desired alignment */ gap_end -= info->length; gap_end -= (gap_end - info->align_offset) & info->align_mask; VM_BUG_ON(gap_end < info->low_limit); VM_BUG_ON(gap_end < gap_start); return gap_end; } /* * Search for an unmapped address range. * * We are looking for a range that: * - does not intersect with any VMA; * - is contained within the [low_limit, high_limit) interval; * - is at least the desired size. * - satisfies (begin_addr & align_mask) == (align_offset & align_mask) */ unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info) { unsigned long addr; if (info->flags & VM_UNMAPPED_AREA_TOPDOWN) addr = unmapped_area_topdown(info); else addr = unmapped_area(info); trace_vm_unmapped_area(addr, info); return addr; } #ifndef arch_get_mmap_end #define arch_get_mmap_end(addr) (TASK_SIZE) #endif #ifndef arch_get_mmap_base #define arch_get_mmap_base(addr, base) (base) #endif /* Get an address range which is currently unmapped. * For shmat() with addr=0. * * Ugly calling convention alert: * Return value with the low bits set means error value, * ie * if (ret & ~PAGE_MASK) * error = ret; * * This function "knows" that -ENOMEM has the bits set. */ #ifndef HAVE_ARCH_UNMAPPED_AREA unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; struct vm_unmapped_area_info info; const unsigned long mmap_end = arch_get_mmap_end(addr); if (len > mmap_end - mmap_min_addr) return -ENOMEM; if (flags & MAP_FIXED) return addr; if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma_prev(mm, addr, &prev); if (mmap_end - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma)) && (!prev || addr >= vm_end_gap(prev))) return addr; } info.flags = 0; info.length = len; info.low_limit = mm->mmap_base; info.high_limit = mmap_end; info.align_mask = 0; info.align_offset = 0; return vm_unmapped_area(&info); } #endif /* * This mmap-allocator allocates new areas top-down from below the * stack's low limit (the base): */ #ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct vm_area_struct *vma, *prev; struct mm_struct *mm = current->mm; struct vm_unmapped_area_info info; const unsigned long mmap_end = arch_get_mmap_end(addr); /* requested length too big for entire address space */ if (len > mmap_end - mmap_min_addr) return -ENOMEM; if (flags & MAP_FIXED) return addr; /* requesting a specific address */ if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma_prev(mm, addr, &prev); if (mmap_end - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma)) && (!prev || addr >= vm_end_gap(prev))) return addr; } info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = max(PAGE_SIZE, mmap_min_addr); info.high_limit = arch_get_mmap_base(addr, mm->mmap_base); info.align_mask = 0; info.align_offset = 0; addr = vm_unmapped_area(&info); /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario * can happen with large stack limits and large mmap() * allocations. */ if (offset_in_page(addr)) { VM_BUG_ON(addr != -ENOMEM); info.flags = 0; info.low_limit = TASK_UNMAPPED_BASE; info.high_limit = mmap_end; addr = vm_unmapped_area(&info); } return addr; } #endif unsigned long get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { unsigned long (*get_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); unsigned long error = arch_mmap_check(addr, len, flags); if (error) return error; /* Careful about overflows.. */ if (len > TASK_SIZE) return -ENOMEM; get_area = current->mm->get_unmapped_area; if (file) { if (file->f_op->get_unmapped_area) get_area = file->f_op->get_unmapped_area; } else if (flags & MAP_SHARED) { /* * mmap_region() will call shmem_zero_setup() to create a file, * so use shmem's get_unmapped_area in case it can be huge. * do_mmap() will clear pgoff, so match alignment. */ pgoff = 0; get_area = shmem_get_unmapped_area; } addr = get_area(file, addr, len, pgoff, flags); if (IS_ERR_VALUE(addr)) return addr; if (addr > TASK_SIZE - len) return -ENOMEM; if (offset_in_page(addr)) return -EINVAL; error = security_mmap_addr(addr); return error ? error : addr; } EXPORT_SYMBOL(get_unmapped_area); /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) { struct rb_node *rb_node; struct vm_area_struct *vma; /* Check the cache first. */ vma = vmacache_find(mm, addr); if (likely(vma)) return vma; rb_node = mm->mm_rb.rb_node; while (rb_node) { struct vm_area_struct *tmp; tmp = rb_entry(rb_node, struct vm_area_struct, vm_rb); if (tmp->vm_end > addr) { vma = tmp; if (tmp->vm_start <= addr) break; rb_node = rb_node->rb_left; } else rb_node = rb_node->rb_right; } if (vma) vmacache_update(addr, vma); return vma; } EXPORT_SYMBOL(find_vma); /* * Same as find_vma, but also return a pointer to the previous VMA in *pprev. */ struct vm_area_struct * find_vma_prev(struct mm_struct *mm, unsigned long addr, struct vm_area_struct **pprev) { struct vm_area_struct *vma; vma = find_vma(mm, addr); if (vma) { *pprev = vma->vm_prev; } else { struct rb_node *rb_node = rb_last(&mm->mm_rb); *pprev = rb_node ? rb_entry(rb_node, struct vm_area_struct, vm_rb) : NULL; } return vma; } /* * Verify that the stack growth is acceptable and * update accounting. This is shared with both the * grow-up and grow-down cases. */ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, unsigned long grow) { struct mm_struct *mm = vma->vm_mm; unsigned long new_start; /* address space limit tests */ if (!may_expand_vm(mm, vma->vm_flags, grow)) return -ENOMEM; /* Stack limit test */ if (size > rlimit(RLIMIT_STACK)) return -ENOMEM; /* mlock limit tests */ if (vma->vm_flags & VM_LOCKED) { unsigned long locked; unsigned long limit; locked = mm->locked_vm + grow; limit = rlimit(RLIMIT_MEMLOCK); limit >>= PAGE_SHIFT; if (locked > limit && !capable(CAP_IPC_LOCK)) return -ENOMEM; } /* Check to ensure the stack will not grow into a hugetlb-only region */ new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start : vma->vm_end - size; if (is_hugepage_only_range(vma->vm_mm, new_start, size)) return -EFAULT; /* * Overcommit.. This must be the final test, as it will * update security statistics. */ if (security_vm_enough_memory_mm(mm, grow)) return -ENOMEM; return 0; } #if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64) /* * PA-RISC uses this for its stack; IA64 for its Register Backing Store. * vma is the last one with address > vma->vm_end. Have to extend vma. */ int expand_upwards(struct vm_area_struct *vma, unsigned long address) { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *next; unsigned long gap_addr; int error = 0; if (!(vma->vm_flags & VM_GROWSUP)) return -EFAULT; /* Guard against exceeding limits of the address space. */ address &= PAGE_MASK; if (address >= (TASK_SIZE & PAGE_MASK)) return -ENOMEM; address += PAGE_SIZE; /* Enforce stack_guard_gap */ gap_addr = address + stack_guard_gap; /* Guard against overflow */ if (gap_addr < address || gap_addr > TASK_SIZE) gap_addr = TASK_SIZE; next = vma->vm_next; if (next && next->vm_start < gap_addr && vma_is_accessible(next)) { if (!(next->vm_flags & VM_GROWSUP)) return -ENOMEM; /* Check that both stack segments have the same anon_vma? */ } /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) return -ENOMEM; /* * vma->vm_start/vm_end cannot change under us because the caller * is required to hold the mmap_lock in read mode. We need the * anon_vma lock to serialize against concurrent expand_stacks. */ anon_vma_lock_write(vma->anon_vma); /* Somebody else might have raced and expanded it already */ if (address > vma->vm_end) { unsigned long size, grow; size = address - vma->vm_start; grow = (address - vma->vm_end) >> PAGE_SHIFT; error = -ENOMEM; if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) { error = acct_stack_growth(vma, size, grow); if (!error) { /* * vma_gap_update() doesn't support concurrent * updates, but we only hold a shared mmap_lock * lock here, so we need to protect against * concurrent vma expansions. * anon_vma_lock_write() doesn't help here, as * we don't guarantee that all growable vmas * in a mm share the same root anon vma. * So, we reuse mm->page_table_lock to guard * against concurrent vma expansions. */ spin_lock(&mm->page_table_lock); if (vma->vm_flags & VM_LOCKED) mm->locked_vm += grow; vm_stat_account(mm, vma->vm_flags, grow); anon_vma_interval_tree_pre_update_vma(vma); vma->vm_end = address; anon_vma_interval_tree_post_update_vma(vma); if (vma->vm_next) vma_gap_update(vma->vm_next); else mm->highest_vm_end = vm_end_gap(vma); spin_unlock(&mm->page_table_lock); perf_event_mmap(vma); } } } anon_vma_unlock_write(vma->anon_vma); khugepaged_enter_vma_merge(vma, vma->vm_flags); validate_mm(mm); return error; } #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ /* * vma is the first one with address < vma->vm_start. Have to extend vma. */ int expand_downwards(struct vm_area_struct *vma, unsigned long address) { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *prev; int error = 0; address &= PAGE_MASK; if (address < mmap_min_addr) return -EPERM; /* Enforce stack_guard_gap */ prev = vma->vm_prev; /* Check that both stack segments have the same anon_vma? */ if (prev && !(prev->vm_flags & VM_GROWSDOWN) && vma_is_accessible(prev)) { if (address - prev->vm_end < stack_guard_gap) return -ENOMEM; } /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) return -ENOMEM; /* * vma->vm_start/vm_end cannot change under us because the caller * is required to hold the mmap_lock in read mode. We need the * anon_vma lock to serialize against concurrent expand_stacks. */ anon_vma_lock_write(vma->anon_vma); /* Somebody else might have raced and expanded it already */ if (address < vma->vm_start) { unsigned long size, grow; size = vma->vm_end - address; grow = (vma->vm_start - address) >> PAGE_SHIFT; error = -ENOMEM; if (grow <= vma->vm_pgoff) { error = acct_stack_growth(vma, size, grow); if (!error) { /* * vma_gap_update() doesn't support concurrent * updates, but we only hold a shared mmap_lock * lock here, so we need to protect against * concurrent vma expansions. * anon_vma_lock_write() doesn't help here, as * we don't guarantee that all growable vmas * in a mm share the same root anon vma. * So, we reuse mm->page_table_lock to guard * against concurrent vma expansions. */ spin_lock(&mm->page_table_lock); if (vma->vm_flags & VM_LOCKED) mm->locked_vm += grow; vm_stat_account(mm, vma->vm_flags, grow); anon_vma_interval_tree_pre_update_vma(vma); vma->vm_start = address; vma->vm_pgoff -= grow; anon_vma_interval_tree_post_update_vma(vma); vma_gap_update(vma); spin_unlock(&mm->page_table_lock); perf_event_mmap(vma); } } } anon_vma_unlock_write(vma->anon_vma); khugepaged_enter_vma_merge(vma, vma->vm_flags); validate_mm(mm); return error; } /* enforced gap between the expanding stack and other mappings. */ unsigned long stack_guard_gap = 256UL<<PAGE_SHIFT; static int __init cmdline_parse_stack_guard_gap(char *p) { unsigned long val; char *endptr; val = simple_strtoul(p, &endptr, 10); if (!*endptr) stack_guard_gap = val << PAGE_SHIFT; return 0; } __setup("stack_guard_gap=", cmdline_parse_stack_guard_gap); #ifdef CONFIG_STACK_GROWSUP int expand_stack(struct vm_area_struct *vma, unsigned long address) { return expand_upwards(vma, address); } struct vm_area_struct * find_extend_vma(struct mm_struct *mm, unsigned long addr) { struct vm_area_struct *vma, *prev; addr &= PAGE_MASK; vma = find_vma_prev(mm, addr, &prev); if (vma && (vma->vm_start <= addr)) return vma; /* don't alter vm_end if the coredump is running */ if (!prev || expand_stack(prev, addr)) return NULL; if (prev->vm_flags & VM_LOCKED) populate_vma_page_range(prev, addr, prev->vm_end, NULL); return prev; } #else int expand_stack(struct vm_area_struct *vma, unsigned long address) { return expand_downwards(vma, address); } struct vm_area_struct * find_extend_vma(struct mm_struct *mm, unsigned long addr) { struct vm_area_struct *vma; unsigned long start; addr &= PAGE_MASK; vma = find_vma(mm, addr); if (!vma) return NULL; if (vma->vm_start <= addr) return vma; if (!(vma->vm_flags & VM_GROWSDOWN)) return NULL; start = vma->vm_start; if (expand_stack(vma, addr)) return NULL; if (vma->vm_flags & VM_LOCKED) populate_vma_page_range(vma, addr, start, NULL); return vma; } #endif EXPORT_SYMBOL_GPL(find_extend_vma); /* * Ok - we have the memory areas we should free on the vma list, * so release them, and do the vma updates. * * Called with the mm semaphore held. */ static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma) { unsigned long nr_accounted = 0; /* Update high watermark before we lower total_vm */ update_hiwater_vm(mm); do { long nrpages = vma_pages(vma); if (vma->vm_flags & VM_ACCOUNT) nr_accounted += nrpages; vm_stat_account(mm, vma->vm_flags, -nrpages); vma = remove_vma(vma); } while (vma); vm_unacct_memory(nr_accounted); validate_mm(mm); } /* * Get rid of page table information in the indicated region. * * Called with the mm semaphore held. */ static void unmap_region(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, unsigned long start, unsigned long end) { struct vm_area_struct *next = vma_next(mm, prev); struct mmu_gather tlb; lru_add_drain(); tlb_gather_mmu(&tlb, mm, start, end); update_hiwater_rss(mm); unmap_vmas(&tlb, vma, start, end); free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS, next ? next->vm_start : USER_PGTABLES_CEILING); tlb_finish_mmu(&tlb, start, end); } /* * Create a list of vma's touched by the unmap, removing them from the mm's * vma list as we go.. */ static bool detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, unsigned long end) { struct vm_area_struct **insertion_point; struct vm_area_struct *tail_vma = NULL; insertion_point = (prev ? &prev->vm_next : &mm->mmap); vma->vm_prev = NULL; do { vma_rb_erase(vma, &mm->mm_rb); mm->map_count--; tail_vma = vma; vma = vma->vm_next; } while (vma && vma->vm_start < end); *insertion_point = vma; if (vma) { vma->vm_prev = prev; vma_gap_update(vma); } else mm->highest_vm_end = prev ? vm_end_gap(prev) : 0; tail_vma->vm_next = NULL; /* Kill the cache */ vmacache_invalidate(mm); /* * Do not downgrade mmap_lock if we are next to VM_GROWSDOWN or * VM_GROWSUP VMA. Such VMAs can change their size under * down_read(mmap_lock) and collide with the VMA we are about to unmap. */ if (vma && (vma->vm_flags & VM_GROWSDOWN)) return false; if (prev && (prev->vm_flags & VM_GROWSUP)) return false; return true; } /* * __split_vma() bypasses sysctl_max_map_count checking. We use this where it * has already been checked or doesn't make sense to fail. */ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, int new_below) { struct vm_area_struct *new; int err; if (vma->vm_ops && vma->vm_ops->split) { err = vma->vm_ops->split(vma, addr); if (err) return err; } new = vm_area_dup(vma); if (!new) return -ENOMEM; if (new_below) new->vm_end = addr; else { new->vm_start = addr; new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT); } err = vma_dup_policy(vma, new); if (err) goto out_free_vma; err = anon_vma_clone(new, vma); if (err) goto out_free_mpol; if (new->vm_file) get_file(new->vm_file); if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); if (new_below) err = vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff + ((addr - new->vm_start) >> PAGE_SHIFT), new); else err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new); /* Success. */ if (!err) return 0; /* Clean everything up if vma_adjust failed. */ if (new->vm_ops && new->vm_ops->close) new->vm_ops->close(new); if (new->vm_file) fput(new->vm_file); unlink_anon_vmas(new); out_free_mpol: mpol_put(vma_policy(new)); out_free_vma: vm_area_free(new); return err; } /* * Split a vma into two pieces at address 'addr', a new vma is allocated * either for the first part or the tail. */ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, int new_below) { if (mm->map_count >= sysctl_max_map_count) return -ENOMEM; return __split_vma(mm, vma, addr, new_below); } /* Munmap is split into 2 main parts -- this part which finds * what needs doing, and the areas themselves, which do the * work. This now handles partial unmappings. * Jeremy Fitzhardinge <jeremy@goop.org> */ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf, bool downgrade) { unsigned long end; struct vm_area_struct *vma, *prev, *last; if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start) return -EINVAL; len = PAGE_ALIGN(len); end = start + len; if (len == 0) return -EINVAL; /* * arch_unmap() might do unmaps itself. It must be called * and finish any rbtree manipulation before this code * runs and also starts to manipulate the rbtree. */ arch_unmap(mm, start, end); /* Find the first overlapping VMA */ vma = find_vma(mm, start); if (!vma) return 0; prev = vma->vm_prev; /* we have start < vma->vm_end */ /* if it doesn't overlap, we have nothing.. */ if (vma->vm_start >= end) return 0; /* * If we need to split any vma, do it now to save pain later. * * Note: mremap's move_vma VM_ACCOUNT handling assumes a partially * unmapped vm_area_struct will remain in use: so lower split_vma * places tmp vma above, and higher split_vma places tmp vma below. */ if (start > vma->vm_start) { int error; /* * Make sure that map_count on return from munmap() will * not exceed its limit; but let map_count go just above * its limit temporarily, to help free resources as expected. */ if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count) return -ENOMEM; error = __split_vma(mm, vma, start, 0); if (error) return error; prev = vma; } /* Does it split the last one? */ last = find_vma(mm, end); if (last && end > last->vm_start) { int error = __split_vma(mm, last, end, 1); if (error) return error; } vma = vma_next(mm, prev); if (unlikely(uf)) { /* * If userfaultfd_unmap_prep returns an error the vmas * will remain splitted, but userland will get a * highly unexpected error anyway. This is no * different than the case where the first of the two * __split_vma fails, but we don't undo the first * split, despite we could. This is unlikely enough * failure that it's not worth optimizing it for. */ int error = userfaultfd_unmap_prep(vma, start, end, uf); if (error) return error; } /* * unlock any mlock()ed ranges before detaching vmas */ if (mm->locked_vm) { struct vm_area_struct *tmp = vma; while (tmp && tmp->vm_start < end) { if (tmp->vm_flags & VM_LOCKED) { mm->locked_vm -= vma_pages(tmp); munlock_vma_pages_all(tmp); } tmp = tmp->vm_next; } } /* Detach vmas from rbtree */ if (!detach_vmas_to_be_unmapped(mm, vma, prev, end)) downgrade = false; if (downgrade) mmap_write_downgrade(mm); unmap_region(mm, vma, prev, start, end); /* Fix up all other VM information */ remove_vma_list(mm, vma); return downgrade ? 1 : 0; } int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) { return __do_munmap(mm, start, len, uf, false); } static int __vm_munmap(unsigned long start, size_t len, bool downgrade) { int ret; struct mm_struct *mm = current->mm; LIST_HEAD(uf); if (mmap_write_lock_killable(mm)) return -EINTR; ret = __do_munmap(mm, start, len, &uf, downgrade); /* * Returning 1 indicates mmap_lock is downgraded. * But 1 is not legal return value of vm_munmap() and munmap(), reset * it to 0 before return. */ if (ret == 1) { mmap_read_unlock(mm); ret = 0; } else mmap_write_unlock(mm); userfaultfd_unmap_complete(mm, &uf); return ret; } int vm_munmap(unsigned long start, size_t len) { return __vm_munmap(start, len, false); } EXPORT_SYMBOL(vm_munmap); SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) { addr = untagged_addr(addr); profile_munmap(addr); return __vm_munmap(addr, len, true); } /* * Emulation of deprecated remap_file_pages() syscall. */ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, unsigned long, prot, unsigned long, pgoff, unsigned long, flags) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long populate = 0; unsigned long ret = -EINVAL; struct file *file; pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.rst.\n", current->comm, current->pid); if (prot) return ret; start = start & PAGE_MASK; size = size & PAGE_MASK; if (start + size <= start) return ret; /* Does pgoff wrap? */ if (pgoff + (size >> PAGE_SHIFT) < pgoff) return ret; if (mmap_write_lock_killable(mm)) return -EINTR; vma = find_vma(mm, start); if (!vma || !(vma->vm_flags & VM_SHARED)) goto out; if (start < vma->vm_start) goto out; if (start + size > vma->vm_end) { struct vm_area_struct *next; for (next = vma->vm_next; next; next = next->vm_next) { /* hole between vmas ? */ if (next->vm_start != next->vm_prev->vm_end) goto out; if (next->vm_file != vma->vm_file) goto out; if (next->vm_flags != vma->vm_flags) goto out; if (start + size <= next->vm_end) break; } if (!next) goto out; } prot |= vma->vm_flags & VM_READ ? PROT_READ : 0; prot |= vma->vm_flags & VM_WRITE ? PROT_WRITE : 0; prot |= vma->vm_flags & VM_EXEC ? PROT_EXEC : 0; flags &= MAP_NONBLOCK; flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE; if (vma->vm_flags & VM_LOCKED) { struct vm_area_struct *tmp; flags |= MAP_LOCKED; /* drop PG_Mlocked flag for over-mapped range */ for (tmp = vma; tmp->vm_start >= start + size; tmp = tmp->vm_next) { /* * Split pmd and munlock page on the border * of the range. */ vma_adjust_trans_huge(tmp, start, start + size, 0); munlock_vma_pages_range(tmp, max(tmp->vm_start, start), min(tmp->vm_end, start + size)); } } file = get_file(vma->vm_file); ret = do_mmap(vma->vm_file, start, size, prot, flags, pgoff, &populate, NULL); fput(file); out: mmap_write_unlock(mm); if (populate) mm_populate(ret, populate); if (!IS_ERR_VALUE(ret)) ret = 0; return ret; } /* * this is really a simplified "do_mmap". it only handles * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long flags, struct list_head *uf) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; struct rb_node **rb_link, *rb_parent; pgoff_t pgoff = addr >> PAGE_SHIFT; int error; unsigned long mapped_addr; /* Until we need other flags, refuse anything except VM_EXEC. */ if ((flags & (~VM_EXEC)) != 0) return -EINVAL; flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; mapped_addr = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED); if (IS_ERR_VALUE(mapped_addr)) return mapped_addr; error = mlock_future_check(mm, mm->def_flags, len); if (error) return error; /* Clear old maps, set up prev, rb_link, rb_parent, and uf */ if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf)) return -ENOMEM; /* Check against address space limits *after* clearing old maps... */ if (!may_expand_vm(mm, flags, len >> PAGE_SHIFT)) return -ENOMEM; if (mm->map_count > sysctl_max_map_count) return -ENOMEM; if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT)) return -ENOMEM; /* Can we just expand an old private anonymous mapping? */ vma = vma_merge(mm, prev, addr, addr + len, flags, NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX); if (vma) goto out; /* * create a vma struct for an anonymous mapping */ vma = vm_area_alloc(mm); if (!vma) { vm_unacct_memory(len >> PAGE_SHIFT); return -ENOMEM; } vma_set_anonymous(vma); vma->vm_start = addr; vma->vm_end = addr + len; vma->vm_pgoff = pgoff; vma->vm_flags = flags; vma->vm_page_prot = vm_get_page_prot(flags); vma_link(mm, vma, prev, rb_link, rb_parent); out: perf_event_mmap(vma); mm->total_vm += len >> PAGE_SHIFT; mm->data_vm += len >> PAGE_SHIFT; if (flags & VM_LOCKED) mm->locked_vm += (len >> PAGE_SHIFT); vma->vm_flags |= VM_SOFTDIRTY; return 0; } int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags) { struct mm_struct *mm = current->mm; unsigned long len; int ret; bool populate; LIST_HEAD(uf); len = PAGE_ALIGN(request); if (len < request) return -ENOMEM; if (!len) return 0; if (mmap_write_lock_killable(mm)) return -EINTR; ret = do_brk_flags(addr, len, flags, &uf); populate = ((mm->def_flags & VM_LOCKED) != 0); mmap_write_unlock(mm); userfaultfd_unmap_complete(mm, &uf); if (populate && !ret) mm_populate(addr, len); return ret; } EXPORT_SYMBOL(vm_brk_flags); int vm_brk(unsigned long addr, unsigned long len) { return vm_brk_flags(addr, len, 0); } EXPORT_SYMBOL(vm_brk); /* Release all mmaps. */ void exit_mmap(struct mm_struct *mm) { struct mmu_gather tlb; struct vm_area_struct *vma; unsigned long nr_accounted = 0; /* mm's last user has gone, and its about to be pulled down */ mmu_notifier_release(mm); if (unlikely(mm_is_oom_victim(mm))) { /* * Manually reap the mm to free as much memory as possible. * Then, as the oom reaper does, set MMF_OOM_SKIP to disregard * this mm from further consideration. Taking mm->mmap_lock for * write after setting MMF_OOM_SKIP will guarantee that the oom * reaper will not run on this mm again after mmap_lock is * dropped. * * Nothing can be holding mm->mmap_lock here and the above call * to mmu_notifier_release(mm) ensures mmu notifier callbacks in * __oom_reap_task_mm() will not block. * * This needs to be done before calling munlock_vma_pages_all(), * which clears VM_LOCKED, otherwise the oom reaper cannot * reliably test it. */ (void)__oom_reap_task_mm(mm); set_bit(MMF_OOM_SKIP, &mm->flags); mmap_write_lock(mm); mmap_write_unlock(mm); } if (mm->locked_vm) { vma = mm->mmap; while (vma) { if (vma->vm_flags & VM_LOCKED) munlock_vma_pages_all(vma); vma = vma->vm_next; } } arch_exit_mmap(mm); vma = mm->mmap; if (!vma) /* Can happen if dup_mmap() received an OOM */ return; lru_add_drain(); flush_cache_mm(mm); tlb_gather_mmu(&tlb, mm, 0, -1); /* update_hiwater_rss(mm) here? but nobody should be looking */ /* Use -1 here to ensure all VMAs in the mm are unmapped */ unmap_vmas(&tlb, vma, 0, -1); free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING); tlb_finish_mmu(&tlb, 0, -1); /* * Walk the list again, actually closing and freeing it, * with preemption enabled, without holding any MM locks. */ while (vma) { if (vma->vm_flags & VM_ACCOUNT) nr_accounted += vma_pages(vma); vma = remove_vma(vma); cond_resched(); } vm_unacct_memory(nr_accounted); } /* Insert vm structure into process list sorted by address * and into the inode's i_mmap tree. If vm_file is non-NULL * then i_mmap_rwsem is taken here. */ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma) { struct vm_area_struct *prev; struct rb_node **rb_link, *rb_parent; if (find_vma_links(mm, vma->vm_start, vma->vm_end, &prev, &rb_link, &rb_parent)) return -ENOMEM; if ((vma->vm_flags & VM_ACCOUNT) && security_vm_enough_memory_mm(mm, vma_pages(vma))) return -ENOMEM; /* * The vm_pgoff of a purely anonymous vma should be irrelevant * until its first write fault, when page's anon_vma and index * are set. But now set the vm_pgoff it will almost certainly * end up with (unless mremap moves it elsewhere before that * first wfault), so /proc/pid/maps tells a consistent story. * * By setting it to reflect the virtual start address of the * vma, merges and splits can happen in a seamless way, just * using the existing file pgoff checks and manipulations. * Similarly in do_mmap and in do_brk_flags. */ if (vma_is_anonymous(vma)) { BUG_ON(vma->anon_vma); vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT; } vma_link(mm, vma, prev, rb_link, rb_parent); return 0; } /* * Copy the vma structure to a new location in the same mm, * prior to moving page table entries, to effect an mremap move. */ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, unsigned long addr, unsigned long len, pgoff_t pgoff, bool *need_rmap_locks) { struct vm_area_struct *vma = *vmap; unsigned long vma_start = vma->vm_start; struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *new_vma, *prev; struct rb_node **rb_link, *rb_parent; bool faulted_in_anon_vma = true; /* * If anonymous vma has not yet been faulted, update new pgoff * to match new location, to increase its chance of merging. */ if (unlikely(vma_is_anonymous(vma) && !vma->anon_vma)) { pgoff = addr >> PAGE_SHIFT; faulted_in_anon_vma = false; } if (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent)) return NULL; /* should never get here */ new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags, vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), vma->vm_userfaultfd_ctx); if (new_vma) { /* * Source vma may have been merged into new_vma */ if (unlikely(vma_start >= new_vma->vm_start && vma_start < new_vma->vm_end)) { /* * The only way we can get a vma_merge with * self during an mremap is if the vma hasn't * been faulted in yet and we were allowed to * reset the dst vma->vm_pgoff to the * destination address of the mremap to allow * the merge to happen. mremap must change the * vm_pgoff linearity between src and dst vmas * (in turn preventing a vma_merge) to be * safe. It is only safe to keep the vm_pgoff * linear if there are no pages mapped yet. */ VM_BUG_ON_VMA(faulted_in_anon_vma, new_vma); *vmap = vma = new_vma; } *need_rmap_locks = (new_vma->vm_pgoff <= vma->vm_pgoff); } else { new_vma = vm_area_dup(vma); if (!new_vma) goto out; new_vma->vm_start = addr; new_vma->vm_end = addr + len; new_vma->vm_pgoff = pgoff; if (vma_dup_policy(vma, new_vma)) goto out_free_vma; if (anon_vma_clone(new_vma, vma)) goto out_free_mempol; if (new_vma->vm_file) get_file(new_vma->vm_file); if (new_vma->vm_ops && new_vma->vm_ops->open) new_vma->vm_ops->open(new_vma); vma_link(mm, new_vma, prev, rb_link, rb_parent); *need_rmap_locks = false; } return new_vma; out_free_mempol: mpol_put(vma_policy(new_vma)); out_free_vma: vm_area_free(new_vma); out: return NULL; } /* * Return true if the calling process may expand its vm space by the passed * number of pages */ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages) { if (mm->total_vm + npages > rlimit(RLIMIT_AS) >> PAGE_SHIFT) return false; if (is_data_mapping(flags) && mm->data_vm + npages > rlimit(RLIMIT_DATA) >> PAGE_SHIFT) { /* Workaround for Valgrind */ if (rlimit(RLIMIT_DATA) == 0 && mm->data_vm + npages <= rlimit_max(RLIMIT_DATA) >> PAGE_SHIFT) return true; pr_warn_once("%s (%d): VmData %lu exceed data ulimit %lu. Update limits%s.\n", current->comm, current->pid, (mm->data_vm + npages) << PAGE_SHIFT, rlimit(RLIMIT_DATA), ignore_rlimit_data ? "" : " or use boot option ignore_rlimit_data"); if (!ignore_rlimit_data) return false; } return true; } void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages) { mm->total_vm += npages; if (is_exec_mapping(flags)) mm->exec_vm += npages; else if (is_stack_mapping(flags)) mm->stack_vm += npages; else if (is_data_mapping(flags)) mm->data_vm += npages; } static vm_fault_t special_mapping_fault(struct vm_fault *vmf); /* * Having a close hook prevents vma merging regardless of flags. */ static void special_mapping_close(struct vm_area_struct *vma) { } static const char *special_mapping_name(struct vm_area_struct *vma) { return ((struct vm_special_mapping *)vma->vm_private_data)->name; } static int special_mapping_mremap(struct vm_area_struct *new_vma) { struct vm_special_mapping *sm = new_vma->vm_private_data; if (WARN_ON_ONCE(current->mm != new_vma->vm_mm)) return -EFAULT; if (sm->mremap) return sm->mremap(sm, new_vma); return 0; } static const struct vm_operations_struct special_mapping_vmops = { .close = special_mapping_close, .fault = special_mapping_fault, .mremap = special_mapping_mremap, .name = special_mapping_name, /* vDSO code relies that VVAR can't be accessed remotely */ .access = NULL, }; static const struct vm_operations_struct legacy_special_mapping_vmops = { .close = special_mapping_close, .fault = special_mapping_fault, }; static vm_fault_t special_mapping_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; pgoff_t pgoff; struct page **pages; if (vma->vm_ops == &legacy_special_mapping_vmops) { pages = vma->vm_private_data; } else { struct vm_special_mapping *sm = vma->vm_private_data; if (sm->fault) return sm->fault(sm, vmf->vma, vmf); pages = sm->pages; } for (pgoff = vmf->pgoff; pgoff && *pages; ++pages) pgoff--; if (*pages) { struct page *page = *pages; get_page(page); vmf->page = page; return 0; } return VM_FAULT_SIGBUS; } static struct vm_area_struct *__install_special_mapping( struct mm_struct *mm, unsigned long addr, unsigned long len, unsigned long vm_flags, void *priv, const struct vm_operations_struct *ops) { int ret; struct vm_area_struct *vma; vma = vm_area_alloc(mm); if (unlikely(vma == NULL)) return ERR_PTR(-ENOMEM); vma->vm_start = addr; vma->vm_end = addr + len; vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); vma->vm_ops = ops; vma->vm_private_data = priv; ret = insert_vm_struct(mm, vma); if (ret) goto out; vm_stat_account(mm, vma->vm_flags, len >> PAGE_SHIFT); perf_event_mmap(vma); return vma; out: vm_area_free(vma); return ERR_PTR(ret); } bool vma_is_special_mapping(const struct vm_area_struct *vma, const struct vm_special_mapping *sm) { return vma->vm_private_data == sm && (vma->vm_ops == &special_mapping_vmops || vma->vm_ops == &legacy_special_mapping_vmops); } /* * Called with mm->mmap_lock held for writing. * Insert a new vma covering the given region, with the given flags. * Its pages are supplied by the given array of struct page *. * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated. * The region past the last page supplied will always produce SIGBUS. * The array pointer and the pages it points to are assumed to stay alive * for as long as this mapping might exist. */ struct vm_area_struct *_install_special_mapping( struct mm_struct *mm, unsigned long addr, unsigned long len, unsigned long vm_flags, const struct vm_special_mapping *spec) { return __install_special_mapping(mm, addr, len, vm_flags, (void *)spec, &special_mapping_vmops); } int install_special_mapping(struct mm_struct *mm, unsigned long addr, unsigned long len, unsigned long vm_flags, struct page **pages) { struct vm_area_struct *vma = __install_special_mapping( mm, addr, len, vm_flags, (void *)pages, &legacy_special_mapping_vmops); return PTR_ERR_OR_ZERO(vma); } static DEFINE_MUTEX(mm_all_locks_mutex); static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) { if (!test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) { /* * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. */ down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_lock); /* * We can safely modify head.next after taking the * anon_vma->root->rwsem. If some other vma in this mm shares * the same anon_vma we won't take it again. * * No need of atomic instructions here, head.next * can't change from under us thanks to the * anon_vma->root->rwsem. */ if (__test_and_set_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) BUG(); } } static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) { if (!test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) { /* * AS_MM_ALL_LOCKS can't change from under us because * we hold the mm_all_locks_mutex. * * Operations on ->flags have to be atomic because * even if AS_MM_ALL_LOCKS is stable thanks to the * mm_all_locks_mutex, there may be other cpus * changing other bitflags in parallel to us. */ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_lock); } } /* * This operation locks against the VM for all pte/vma/mm related * operations that could ever happen on a certain mm. This includes * vmtruncate, try_to_unmap, and all page faults. * * The caller must take the mmap_lock in write mode before calling * mm_take_all_locks(). The caller isn't allowed to release the * mmap_lock until mm_drop_all_locks() returns. * * mmap_lock in write mode is required in order to block all operations * that could modify pagetables and free pages without need of * altering the vma layout. It's also needed in write mode to avoid new * anon_vmas to be associated with existing vmas. * * A single task can't take more than one mm_take_all_locks() in a row * or it would deadlock. * * The LSB in anon_vma->rb_root.rb_node and the AS_MM_ALL_LOCKS bitflag in * mapping->flags avoid to take the same lock twice, if more than one * vma in this mm is backed by the same anon_vma or address_space. * * We take locks in following order, accordingly to comment at beginning * of mm/rmap.c: * - all hugetlbfs_i_mmap_rwsem_key locks (aka mapping->i_mmap_rwsem for * hugetlb mapping); * - all i_mmap_rwsem locks; * - all anon_vma->rwseml * * We can take all locks within these types randomly because the VM code * doesn't nest them and we protected from parallel mm_take_all_locks() by * mm_all_locks_mutex. * * mm_take_all_locks() and mm_drop_all_locks are expensive operations * that may have to take thousand of locks. * * mm_take_all_locks() can fail if it's interrupted by signals. */ int mm_take_all_locks(struct mm_struct *mm) { struct vm_area_struct *vma; struct anon_vma_chain *avc; BUG_ON(mmap_read_trylock(mm)); mutex_lock(&mm_all_locks_mutex); for (vma = mm->mmap; vma; vma = vma->vm_next) { if (signal_pending(current)) goto out_unlock; if (vma->vm_file && vma->vm_file->f_mapping && is_vm_hugetlb_page(vma)) vm_lock_mapping(mm, vma->vm_file->f_mapping); } for (vma = mm->mmap; vma; vma = vma->vm_next) { if (signal_pending(current)) goto out_unlock; if (vma->vm_file && vma->vm_file->f_mapping && !is_vm_hugetlb_page(vma)) vm_lock_mapping(mm, vma->vm_file->f_mapping); } for (vma = mm->mmap; vma; vma = vma->vm_next) { if (signal_pending(current)) goto out_unlock; if (vma->anon_vma) list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) vm_lock_anon_vma(mm, avc->anon_vma); } return 0; out_unlock: mm_drop_all_locks(mm); return -EINTR; } static void vm_unlock_anon_vma(struct anon_vma *anon_vma) { if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) { /* * The LSB of head.next can't change to 0 from under * us because we hold the mm_all_locks_mutex. * * We must however clear the bitflag before unlocking * the vma so the users using the anon_vma->rb_root will * never see our bitflag. * * No need of atomic instructions here, head.next * can't change from under us until we release the * anon_vma->root->rwsem. */ if (!__test_and_clear_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) BUG(); anon_vma_unlock_write(anon_vma); } } static void vm_unlock_mapping(struct address_space *mapping) { if (test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) { /* * AS_MM_ALL_LOCKS can't change to 0 from under us * because we hold the mm_all_locks_mutex. */ i_mmap_unlock_write(mapping); if (!test_and_clear_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); } } /* * The mmap_lock cannot be released by the caller until * mm_drop_all_locks() returns. */ void mm_drop_all_locks(struct mm_struct *mm) { struct vm_area_struct *vma; struct anon_vma_chain *avc; BUG_ON(mmap_read_trylock(mm)); BUG_ON(!mutex_is_locked(&mm_all_locks_mutex)); for (vma = mm->mmap; vma; vma = vma->vm_next) { if (vma->anon_vma) list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) vm_unlock_anon_vma(avc->anon_vma); if (vma->vm_file && vma->vm_file->f_mapping) vm_unlock_mapping(vma->vm_file->f_mapping); } mutex_unlock(&mm_all_locks_mutex); } /* * initialise the percpu counter for VM */ void __init mmap_init(void) { int ret; ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); VM_BUG_ON(ret); } /* * Initialise sysctl_user_reserve_kbytes. * * This is intended to prevent a user from starting a single memory hogging * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER * mode. * * The default value is min(3% of free memory, 128MB) * 128MB is enough to recover with sshd/login, bash, and top/kill. */ static int init_user_reserve(void) { unsigned long free_kbytes; free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); return 0; } subsys_initcall(init_user_reserve); /* * Initialise sysctl_admin_reserve_kbytes. * * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin * to log in and kill a memory hogging process. * * Systems with more than 256MB will reserve 8MB, enough to recover * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will * only reserve 3% of free pages by default. */ static int init_admin_reserve(void) { unsigned long free_kbytes; free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); return 0; } subsys_initcall(init_admin_reserve); /* * Reinititalise user and admin reserves if memory is added or removed. * * The default user reserve max is 128MB, and the default max for the * admin reserve is 8MB. These are usually, but not always, enough to * enable recovery from a memory hogging process using login/sshd, a shell, * and tools like top. It may make sense to increase or even disable the * reserve depending on the existence of swap or variations in the recovery * tools. So, the admin may have changed them. * * If memory is added and the reserves have been eliminated or increased above * the default max, then we'll trust the admin. * * If memory is removed and there isn't enough free memory, then we * need to reset the reserves. * * Otherwise keep the reserve set by the admin. */ static int reserve_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) { unsigned long tmp, free_kbytes; switch (action) { case MEM_ONLINE: /* Default max is 128MB. Leave alone if modified by operator. */ tmp = sysctl_user_reserve_kbytes; if (0 < tmp && tmp < (1UL << 17)) init_user_reserve(); /* Default max is 8MB. Leave alone if modified by operator. */ tmp = sysctl_admin_reserve_kbytes; if (0 < tmp && tmp < (1UL << 13)) init_admin_reserve(); break; case MEM_OFFLINE: free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); if (sysctl_user_reserve_kbytes > free_kbytes) { init_user_reserve(); pr_info("vm.user_reserve_kbytes reset to %lu\n", sysctl_user_reserve_kbytes); } if (sysctl_admin_reserve_kbytes > free_kbytes) { init_admin_reserve(); pr_info("vm.admin_reserve_kbytes reset to %lu\n", sysctl_admin_reserve_kbytes); } break; default: break; } return NOTIFY_OK; } static struct notifier_block reserve_mem_nb = { .notifier_call = reserve_mem_notifier, }; static int __meminit init_reserve_notifier(void) { if (register_hotmemory_notifier(&reserve_mem_nb)) pr_err("Failed registering memory add/remove notifier for admin reserve\n"); return 0; } subsys_initcall(init_reserve_notifier);
1 1 1 1 1 1 1 1 1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_PAGEMAP_H #define _LINUX_PAGEMAP_H /* * Copyright 1995 Linus Torvalds */ #include <linux/mm.h> #include <linux/fs.h> #include <linux/list.h> #include <linux/highmem.h> #include <linux/compiler.h> #include <linux/uaccess.h> #include <linux/gfp.h> #include <linux/bitops.h> #include <linux/hardirq.h> /* for in_interrupt() */ #include <linux/hugetlb_inline.h> struct pagevec; /* * Bits in mapping->flags. */ enum mapping_flags { AS_EIO = 0, /* IO error on async write */ AS_ENOSPC = 1, /* ENOSPC on async write */ AS_MM_ALL_LOCKS = 2, /* under mm_take_all_locks() */ AS_UNEVICTABLE = 3, /* e.g., ramdisk, SHM_LOCK */ AS_EXITING = 4, /* final truncate in progress */ /* writeback related tags are not used */ AS_NO_WRITEBACK_TAGS = 5, AS_THP_SUPPORT = 6, /* THPs supported */ }; /** * mapping_set_error - record a writeback error in the address_space * @mapping: the mapping in which an error should be set * @error: the error to set in the mapping * * When writeback fails in some way, we must record that error so that * userspace can be informed when fsync and the like are called. We endeavor * to report errors on any file that was open at the time of the error. Some * internal callers also need to know when writeback errors have occurred. * * When a writeback error occurs, most filesystems will want to call * mapping_set_error to record the error in the mapping so that it can be * reported when the application calls fsync(2). */ static inline void mapping_set_error(struct address_space *mapping, int error) { if (likely(!error)) return; /* Record in wb_err for checkers using errseq_t based tracking */ __filemap_set_wb_err(mapping, error); /* Record it in superblock */ if (mapping->host) errseq_set(&mapping->host->i_sb->s_wb_err, error); /* Record it in flags for now, for legacy callers */ if (error == -ENOSPC) set_bit(AS_ENOSPC, &mapping->flags); else set_bit(AS_EIO, &mapping->flags); } static inline void mapping_set_unevictable(struct address_space *mapping) { set_bit(AS_UNEVICTABLE, &mapping->flags); } static inline void mapping_clear_unevictable(struct address_space *mapping) { clear_bit(AS_UNEVICTABLE, &mapping->flags); } static inline bool mapping_unevictable(struct address_space *mapping) { return mapping && test_bit(AS_UNEVICTABLE, &mapping->flags); } static inline void mapping_set_exiting(struct address_space *mapping) { set_bit(AS_EXITING, &mapping->flags); } static inline int mapping_exiting(struct address_space *mapping) { return test_bit(AS_EXITING, &mapping->flags); } static inline void mapping_set_no_writeback_tags(struct address_space *mapping) { set_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags); } static inline int mapping_use_writeback_tags(struct address_space *mapping) { return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags); } static inline gfp_t mapping_gfp_mask(struct address_space * mapping) { return mapping->gfp_mask; } /* Restricts the given gfp_mask to what the mapping allows. */ static inline gfp_t mapping_gfp_constraint(struct address_space *mapping, gfp_t gfp_mask) { return mapping_gfp_mask(mapping) & gfp_mask; } /* * This is non-atomic. Only to be used before the mapping is activated. * Probably needs a barrier... */ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) { m->gfp_mask = mask; } static inline bool mapping_thp_support(struct address_space *mapping) { return test_bit(AS_THP_SUPPORT, &mapping->flags); } static inline int filemap_nr_thps(struct address_space *mapping) { #ifdef CONFIG_READ_ONLY_THP_FOR_FS return atomic_read(&mapping->nr_thps); #else return 0; #endif } static inline void filemap_nr_thps_inc(struct address_space *mapping) { #ifdef CONFIG_READ_ONLY_THP_FOR_FS if (!mapping_thp_support(mapping)) atomic_inc(&mapping->nr_thps); #else WARN_ON_ONCE(1); #endif } static inline void filemap_nr_thps_dec(struct address_space *mapping) { #ifdef CONFIG_READ_ONLY_THP_FOR_FS if (!mapping_thp_support(mapping)) atomic_dec(&mapping->nr_thps); #else WARN_ON_ONCE(1); #endif } void release_pages(struct page **pages, int nr); /* * speculatively take a reference to a page. * If the page is free (_refcount == 0), then _refcount is untouched, and 0 * is returned. Otherwise, _refcount is incremented by 1 and 1 is returned. * * This function must be called inside the same rcu_read_lock() section as has * been used to lookup the page in the pagecache radix-tree (or page table): * this allows allocators to use a synchronize_rcu() to stabilize _refcount. * * Unless an RCU grace period has passed, the count of all pages coming out * of the allocator must be considered unstable. page_count may return higher * than expected, and put_page must be able to do the right thing when the * page has been finished with, no matter what it is subsequently allocated * for (because put_page is what is used here to drop an invalid speculative * reference). * * This is the interesting part of the lockless pagecache (and lockless * get_user_pages) locking protocol, where the lookup-side (eg. find_get_page) * has the following pattern: * 1. find page in radix tree * 2. conditionally increment refcount * 3. check the page is still in pagecache (if no, goto 1) * * Remove-side that cares about stability of _refcount (eg. reclaim) has the * following (with the i_pages lock held): * A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg) * B. remove page from pagecache * C. free the page * * There are 2 critical interleavings that matter: * - 2 runs before A: in this case, A sees elevated refcount and bails out * - A runs before 2: in this case, 2 sees zero refcount and retries; * subsequently, B will complete and 1 will find no page, causing the * lookup to return NULL. * * It is possible that between 1 and 2, the page is removed then the exact same * page is inserted into the same position in pagecache. That's OK: the * old find_get_page using a lock could equally have run before or after * such a re-insertion, depending on order that locks are granted. * * Lookups racing against pagecache insertion isn't a big problem: either 1 * will find the page or it will not. Likewise, the old find_get_page could run * either before the insertion or afterwards, depending on timing. */ static inline int __page_cache_add_speculative(struct page *page, int count) { #ifdef CONFIG_TINY_RCU # ifdef CONFIG_PREEMPT_COUNT VM_BUG_ON(!in_atomic() && !irqs_disabled()); # endif /* * Preempt must be disabled here - we rely on rcu_read_lock doing * this for us. * * Pagecache won't be truncated from interrupt context, so if we have * found a page in the radix tree here, we have pinned its refcount by * disabling preempt, and hence no need for the "speculative get" that * SMP requires. */ VM_BUG_ON_PAGE(page_count(page) == 0, page); page_ref_add(page, count); #else if (unlikely(!page_ref_add_unless(page, count, 0))) { /* * Either the page has been freed, or will be freed. * In either case, retry here and the caller should * do the right thing (see comments above). */ return 0; } #endif VM_BUG_ON_PAGE(PageTail(page), page); return 1; } static inline int page_cache_get_speculative(struct page *page) { return __page_cache_add_speculative(page, 1); } static inline int page_cache_add_speculative(struct page *page, int count) { return __page_cache_add_speculative(page, count); } /** * attach_page_private - Attach private data to a page. * @page: Page to attach data to. * @data: Data to attach to page. * * Attaching private data to a page increments the page's reference count. * The data must be detached before the page will be freed. */ static inline void attach_page_private(struct page *page, void *data) { get_page(page); set_page_private(page, (unsigned long)data); SetPagePrivate(page); } /** * detach_page_private - Detach private data from a page. * @page: Page to detach data from. * * Removes the data that was previously attached to the page and decrements * the refcount on the page. * * Return: Data that was attached to the page. */ static inline void *detach_page_private(struct page *page) { void *data = (void *)page_private(page); if (!PagePrivate(page)) return NULL; ClearPagePrivate(page); set_page_private(page, 0); put_page(page); return data; } #ifdef CONFIG_NUMA extern struct page *__page_cache_alloc(gfp_t gfp); #else static inline struct page *__page_cache_alloc(gfp_t gfp) { return alloc_pages(gfp, 0); } #endif static inline struct page *page_cache_alloc(struct address_space *x) { return __page_cache_alloc(mapping_gfp_mask(x)); } static inline gfp_t readahead_gfp_mask(struct address_space *x) { return mapping_gfp_mask(x) | __GFP_NORETRY | __GFP_NOWARN; } typedef int filler_t(void *, struct page *); pgoff_t page_cache_next_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan); pgoff_t page_cache_prev_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan); #define FGP_ACCESSED 0x00000001 #define FGP_LOCK 0x00000002 #define FGP_CREAT 0x00000004 #define FGP_WRITE 0x00000008 #define FGP_NOFS 0x00000010 #define FGP_NOWAIT 0x00000020 #define FGP_FOR_MMAP 0x00000040 #define FGP_HEAD 0x00000080 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, int fgp_flags, gfp_t cache_gfp_mask); /** * find_get_page - find and get a page reference * @mapping: the address_space to search * @offset: the page index * * Looks up the page cache slot at @mapping & @offset. If there is a * page cache page, it is returned with an increased refcount. * * Otherwise, %NULL is returned. */ static inline struct page *find_get_page(struct address_space *mapping, pgoff_t offset) { return pagecache_get_page(mapping, offset, 0, 0); } static inline struct page *find_get_page_flags(struct address_space *mapping, pgoff_t offset, int fgp_flags) { return pagecache_get_page(mapping, offset, fgp_flags, 0); } /** * find_lock_page - locate, pin and lock a pagecache page * @mapping: the address_space to search * @index: the page index * * Looks up the page cache entry at @mapping & @index. If there is a * page cache page, it is returned locked and with an increased * refcount. * * Context: May sleep. * Return: A struct page or %NULL if there is no page in the cache for this * index. */ static inline struct page *find_lock_page(struct address_space *mapping, pgoff_t index) { return pagecache_get_page(mapping, index, FGP_LOCK, 0); } /** * find_lock_head - Locate, pin and lock a pagecache page. * @mapping: The address_space to search. * @index: The page index. * * Looks up the page cache entry at @mapping & @index. If there is a * page cache page, its head page is returned locked and with an increased * refcount. * * Context: May sleep. * Return: A struct page which is !PageTail, or %NULL if there is no page * in the cache for this index. */ static inline struct page *find_lock_head(struct address_space *mapping, pgoff_t index) { return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0); } /** * find_or_create_page - locate or add a pagecache page * @mapping: the page's address_space * @index: the page's index into the mapping * @gfp_mask: page allocation mode * * Looks up the page cache slot at @mapping & @offset. If there is a * page cache page, it is returned locked and with an increased * refcount. * * If the page is not present, a new page is allocated using @gfp_mask * and added to the page cache and the VM's LRU list. The page is * returned locked and with an increased refcount. * * On memory exhaustion, %NULL is returned. * * find_or_create_page() may sleep, even if @gfp_flags specifies an * atomic allocation! */ static inline struct page *find_or_create_page(struct address_space *mapping, pgoff_t index, gfp_t gfp_mask) { return pagecache_get_page(mapping, index, FGP_LOCK|FGP_ACCESSED|FGP_CREAT, gfp_mask); } /** * grab_cache_page_nowait - returns locked page at given index in given cache * @mapping: target address_space * @index: the page index * * Same as grab_cache_page(), but do not wait if the page is unavailable. * This is intended for speculative data generators, where the data can * be regenerated if the page couldn't be grabbed. This routine should * be safe to call while holding the lock for another page. * * Clear __GFP_FS when allocating the page to avoid recursion into the fs * and deadlock against the caller's locked page. */ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, pgoff_t index) { return pagecache_get_page(mapping, index, FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT, mapping_gfp_mask(mapping)); } /* Does this page contain this index? */ static inline bool thp_contains(struct page *head, pgoff_t index) { /* HugeTLBfs indexes the page cache in units of hpage_size */ if (PageHuge(head)) return head->index == index; return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL)); } /* * Given the page we found in the page cache, return the page corresponding * to this index in the file */ static inline struct page *find_subpage(struct page *head, pgoff_t index) { /* HugeTLBfs wants the head page regardless */ if (PageHuge(head)) return head; return head + (index & (thp_nr_pages(head) - 1)); } unsigned find_get_entries(struct address_space *mapping, pgoff_t start, unsigned int nr_entries, struct page **entries, pgoff_t *indices); unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, pgoff_t end, unsigned int nr_pages, struct page **pages); static inline unsigned find_get_pages(struct address_space *mapping, pgoff_t *start, unsigned int nr_pages, struct page **pages) { return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages, pages); } unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start, unsigned int nr_pages, struct page **pages); unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, pgoff_t end, xa_mark_t tag, unsigned int nr_pages, struct page **pages); static inline unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index, xa_mark_t tag, unsigned int nr_pages, struct page **pages) { return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag, nr_pages, pages); } struct page *grab_cache_page_write_begin(struct address_space *mapping, pgoff_t index, unsigned flags); /* * Returns locked page at given index in given cache, creating it if needed. */ static inline struct page *grab_cache_page(struct address_space *mapping, pgoff_t index) { return find_or_create_page(mapping, index, mapping_gfp_mask(mapping)); } extern struct page * read_cache_page(struct address_space *mapping, pgoff_t index, filler_t *filler, void *data); extern struct page * read_cache_page_gfp(struct address_space *mapping, pgoff_t index, gfp_t gfp_mask); extern int read_cache_pages(struct address_space *mapping, struct list_head *pages, filler_t *filler, void *data); static inline struct page *read_mapping_page(struct address_space *mapping, pgoff_t index, void *data) { return read_cache_page(mapping, index, NULL, data); } /* * Get index of the page within radix-tree (but not for hugetlb pages). * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE) */ static inline pgoff_t page_to_index(struct page *page) { pgoff_t pgoff; if (likely(!PageTransTail(page))) return page->index; /* * We don't initialize ->index for tail pages: calculate based on * head page */ pgoff = compound_head(page)->index; pgoff += page - compound_head(page); return pgoff; } extern pgoff_t hugetlb_basepage_index(struct page *page); /* * Get the offset in PAGE_SIZE (even for hugetlb pages). * (TODO: hugetlb pages should have ->index in PAGE_SIZE) */ static inline pgoff_t page_to_pgoff(struct page *page) { if (unlikely(PageHuge(page))) return hugetlb_basepage_index(page); return page_to_index(page); } /* * Return byte-offset into filesystem object for page. */ static inline loff_t page_offset(struct page *page) { return ((loff_t)page->index) << PAGE_SHIFT; } static inline loff_t page_file_offset(struct page *page) { return ((loff_t)page_index(page)) << PAGE_SHIFT; } extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma, unsigned long address); static inline pgoff_t linear_page_index(struct vm_area_struct *vma, unsigned long address) { pgoff_t pgoff; if (unlikely(is_vm_hugetlb_page(vma))) return linear_hugepage_index(vma, address); pgoff = (address - vma->vm_start) >> PAGE_SHIFT; pgoff += vma->vm_pgoff; return pgoff; } struct wait_page_key { struct page *page; int bit_nr; int page_match; }; struct wait_page_queue { struct page *page; int bit_nr; wait_queue_entry_t wait; }; static inline bool wake_page_match(struct wait_page_queue *wait_page, struct wait_page_key *key) { if (wait_page->page != key->page) return false; key->page_match = 1; if (wait_page->bit_nr != key->bit_nr) return false; return true; } extern void __lock_page(struct page *page); extern int __lock_page_killable(struct page *page); extern int __lock_page_async(struct page *page, struct wait_page_queue *wait); extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags); extern void unlock_page(struct page *page); /* * Return true if the page was successfully locked */ static inline int trylock_page(struct page *page) { page = compound_head(page); return (likely(!test_and_set_bit_lock(PG_locked, &page->flags))); } /* * lock_page may only be called if we have the page's inode pinned. */ static inline void lock_page(struct page *page) { might_sleep(); if (!trylock_page(page)) __lock_page(page); } /* * lock_page_killable is like lock_page but can be interrupted by fatal * signals. It returns 0 if it locked the page and -EINTR if it was * killed while waiting. */ static inline int lock_page_killable(struct page *page) { might_sleep(); if (!trylock_page(page)) return __lock_page_killable(page); return 0; } /* * lock_page_async - Lock the page, unless this would block. If the page * is already locked, then queue a callback when the page becomes unlocked. * This callback can then retry the operation. * * Returns 0 if the page is locked successfully, or -EIOCBQUEUED if the page * was already locked and the callback defined in 'wait' was queued. */ static inline int lock_page_async(struct page *page, struct wait_page_queue *wait) { if (!trylock_page(page)) return __lock_page_async(page, wait); return 0; } /* * lock_page_or_retry - Lock the page, unless this would block and the * caller indicated that it can handle a retry. * * Return value and mmap_lock implications depend on flags; see * __lock_page_or_retry(). */ static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags) { might_sleep(); return trylock_page(page) || __lock_page_or_retry(page, mm, flags); } /* * This is exported only for wait_on_page_locked/wait_on_page_writeback, etc., * and should not be used directly. */ extern void wait_on_page_bit(struct page *page, int bit_nr); extern int wait_on_page_bit_killable(struct page *page, int bit_nr); /* * Wait for a page to be unlocked. * * This must be called with the caller "holding" the page, * ie with increased "page->count" so that the page won't * go away during the wait.. */ static inline void wait_on_page_locked(struct page *page) { if (PageLocked(page)) wait_on_page_bit(compound_head(page), PG_locked); } static inline int wait_on_page_locked_killable(struct page *page) { if (!PageLocked(page)) return 0; return wait_on_page_bit_killable(compound_head(page), PG_locked); } extern void put_and_wait_on_page_locked(struct page *page); void wait_on_page_writeback(struct page *page); extern void end_page_writeback(struct page *page); void wait_for_stable_page(struct page *page); void page_endio(struct page *page, bool is_write, int err); /* * Add an arbitrary waiter to a page's wait queue */ extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter); /* * Fault everything in given userspace address range in. */ static inline int fault_in_pages_writeable(char __user *uaddr, int size) { char __user *end = uaddr + size - 1; if (unlikely(size == 0)) return 0; if (unlikely(uaddr > end)) return -EFAULT; /* * Writing zeroes into userspace here is OK, because we know that if * the zero gets there, we'll be overwriting it. */ do { if (unlikely(__put_user(0, uaddr) != 0)) return -EFAULT; uaddr += PAGE_SIZE; } while (uaddr <= end); /* Check whether the range spilled into the next page. */ if (((unsigned long)uaddr & PAGE_MASK) == ((unsigned long)end & PAGE_MASK)) return __put_user(0, end); return 0; } static inline int fault_in_pages_readable(const char __user *uaddr, int size) { volatile char c; const char __user *end = uaddr + size - 1; if (unlikely(size == 0)) return 0; if (unlikely(uaddr > end)) return -EFAULT; do { if (unlikely(__get_user(c, uaddr) != 0)) return -EFAULT; uaddr += PAGE_SIZE; } while (uaddr <= end); /* Check whether the range spilled into the next page. */ if (((unsigned long)uaddr & PAGE_MASK) == ((unsigned long)end & PAGE_MASK)) { return __get_user(c, end); } (void)c; return 0; } int add_to_page_cache_locked(struct page *page, struct address_space *mapping, pgoff_t index, gfp_t gfp_mask); int add_to_page_cache_lru(struct page *page, struct address_space *mapping, pgoff_t index, gfp_t gfp_mask); extern void delete_from_page_cache(struct page *page); extern void __delete_from_page_cache(struct page *page, void *shadow); int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask); void delete_from_page_cache_batch(struct address_space *mapping, struct pagevec *pvec); /* * Like add_to_page_cache_locked, but used to add newly allocated pages: * the page is new, so we can just run __SetPageLocked() against it. */ static inline int add_to_page_cache(struct page *page, struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask) { int error; __SetPageLocked(page); error = add_to_page_cache_locked(page, mapping, offset, gfp_mask); if (unlikely(error)) __ClearPageLocked(page); return error; } /** * struct readahead_control - Describes a readahead request. * * A readahead request is for consecutive pages. Filesystems which * implement the ->readahead method should call readahead_page() or * readahead_page_batch() in a loop and attempt to start I/O against * each page in the request. * * Most of the fields in this struct are private and should be accessed * by the functions below. * * @file: The file, used primarily by network filesystems for authentication. * May be NULL if invoked internally by the filesystem. * @mapping: Readahead this filesystem object. */ struct readahead_control { struct file *file; struct address_space *mapping; /* private: use the readahead_* accessors instead */ pgoff_t _index; unsigned int _nr_pages; unsigned int _batch_count; }; #define DEFINE_READAHEAD(rac, f, m, i) \ struct readahead_control rac = { \ .file = f, \ .mapping = m, \ ._index = i, \ } #define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE) void page_cache_ra_unbounded(struct readahead_control *, unsigned long nr_to_read, unsigned long lookahead_count); void page_cache_sync_ra(struct readahead_control *, struct file_ra_state *, unsigned long req_count); void page_cache_async_ra(struct readahead_control *, struct file_ra_state *, struct page *, unsigned long req_count); /** * page_cache_sync_readahead - generic file readahead * @mapping: address_space which holds the pagecache and I/O vectors * @ra: file_ra_state which holds the readahead state * @file: Used by the filesystem for authentication. * @index: Index of first page to be read. * @req_count: Total number of pages being read by the caller. * * page_cache_sync_readahead() should be called when a cache miss happened: * it will submit the read. The readahead logic may decide to piggyback more * pages onto the read request if access patterns suggest it will improve * performance. */ static inline void page_cache_sync_readahead(struct address_space *mapping, struct file_ra_state *ra, struct file *file, pgoff_t index, unsigned long req_count) { DEFINE_READAHEAD(ractl, file, mapping, index); page_cache_sync_ra(&ractl, ra, req_count); } /** * page_cache_async_readahead - file readahead for marked pages * @mapping: address_space which holds the pagecache and I/O vectors * @ra: file_ra_state which holds the readahead state * @file: Used by the filesystem for authentication. * @page: The page at @index which triggered the readahead call. * @index: Index of first page to be read. * @req_count: Total number of pages being read by the caller. * * page_cache_async_readahead() should be called when a page is used which * is marked as PageReadahead; this is a marker to suggest that the application * has used up enough of the readahead window that we should start pulling in * more pages. */ static inline void page_cache_async_readahead(struct address_space *mapping, struct file_ra_state *ra, struct file *file, struct page *page, pgoff_t index, unsigned long req_count) { DEFINE_READAHEAD(ractl, file, mapping, index); page_cache_async_ra(&ractl, ra, page, req_count); } /** * readahead_page - Get the next page to read. * @rac: The current readahead request. * * Context: The page is locked and has an elevated refcount. The caller * should decreases the refcount once the page has been submitted for I/O * and unlock the page once all I/O to that page has completed. * Return: A pointer to the next page, or %NULL if we are done. */ static inline struct page *readahead_page(struct readahead_control *rac) { struct page *page; BUG_ON(rac->_batch_count > rac->_nr_pages); rac->_nr_pages -= rac->_batch_count; rac->_index += rac->_batch_count; if (!rac->_nr_pages) { rac->_batch_count = 0; return NULL; } page = xa_load(&rac->mapping->i_pages, rac->_index); VM_BUG_ON_PAGE(!PageLocked(page), page); rac->_batch_count = thp_nr_pages(page); return page; } static inline unsigned int __readahead_batch(struct readahead_control *rac, struct page **array, unsigned int array_sz) { unsigned int i = 0; XA_STATE(xas, &rac->mapping->i_pages, 0); struct page *page; BUG_ON(rac->_batch_count > rac->_nr_pages); rac->_nr_pages -= rac->_batch_count; rac->_index += rac->_batch_count; rac->_batch_count = 0; xas_set(&xas, rac->_index); rcu_read_lock(); xas_for_each(&xas, page, rac->_index + rac->_nr_pages - 1) { if (xas_retry(&xas, page)) continue; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageTail(page), page); array[i++] = page; rac->_batch_count += thp_nr_pages(page); /* * The page cache isn't using multi-index entries yet, * so the xas cursor needs to be manually moved to the * next index. This can be removed once the page cache * is converted. */ if (PageHead(page)) xas_set(&xas, rac->_index + rac->_batch_count); if (i == array_sz) break; } rcu_read_unlock(); return i; } /** * readahead_page_batch - Get a batch of pages to read. * @rac: The current readahead request. * @array: An array of pointers to struct page. * * Context: The pages are locked and have an elevated refcount. The caller * should decreases the refcount once the page has been submitted for I/O * and unlock the page once all I/O to that page has completed. * Return: The number of pages placed in the array. 0 indicates the request * is complete. */ #define readahead_page_batch(rac, array) \ __readahead_batch(rac, array, ARRAY_SIZE(array)) /** * readahead_pos - The byte offset into the file of this readahead request. * @rac: The readahead request. */ static inline loff_t readahead_pos(struct readahead_control *rac) { return (loff_t)rac->_index * PAGE_SIZE; } /** * readahead_length - The number of bytes in this readahead request. * @rac: The readahead request. */ static inline loff_t readahead_length(struct readahead_control *rac) { return (loff_t)rac->_nr_pages * PAGE_SIZE; } /** * readahead_index - The index of the first page in this readahead request. * @rac: The readahead request. */ static inline pgoff_t readahead_index(struct readahead_control *rac) { return rac->_index; } /** * readahead_count - The number of pages in this readahead request. * @rac: The readahead request. */ static inline unsigned int readahead_count(struct readahead_control *rac) { return rac->_nr_pages; } static inline unsigned long dir_pages(struct inode *inode) { return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; } /** * page_mkwrite_check_truncate - check if page was truncated * @page: the page to check * @inode: the inode to check the page against * * Returns the number of bytes in the page up to EOF, * or -EFAULT if the page was truncated. */ static inline int page_mkwrite_check_truncate(struct page *page, struct inode *inode) { loff_t size = i_size_read(inode); pgoff_t index = size >> PAGE_SHIFT; int offset = offset_in_page(size); if (page->mapping != inode->i_mapping) return -EFAULT; /* page is wholly inside EOF */ if (page->index < index) return PAGE_SIZE; /* page is wholly past EOF */ if (page->index > index || !offset) return -EFAULT; /* page is partially inside EOF */ return offset; } /** * i_blocks_per_page - How many blocks fit in this page. * @inode: The inode which contains the blocks. * @page: The page (head page if the page is a THP). * * If the block size is larger than the size of this page, return zero. * * Context: The caller should hold a refcount on the page to prevent it * from being split. * Return: The number of filesystem blocks covered by this page. */ static inline unsigned int i_blocks_per_page(struct inode *inode, struct page *page) { return thp_size(page) >> inode->i_blkbits; } #endif /* _LINUX_PAGEMAP_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_TIMERQUEUE_H #define _LINUX_TIMERQUEUE_H #include <linux/rbtree.h> #include <linux/ktime.h> struct timerqueue_node { struct rb_node node; ktime_t expires; }; struct timerqueue_head { struct rb_root_cached rb_root; }; extern bool timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node); extern bool timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node); extern struct timerqueue_node *timerqueue_iterate_next( struct timerqueue_node *node); /** * timerqueue_getnext - Returns the timer with the earliest expiration time * * @head: head of timerqueue * * Returns a pointer to the timer node that has the earliest expiration time. */ static inline struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head) { struct rb_node *leftmost = rb_first_cached(&head->rb_root); return rb_entry(leftmost, struct timerqueue_node, node); } static inline void timerqueue_init(struct timerqueue_node *node) { RB_CLEAR_NODE(&node->node); } static inline bool timerqueue_node_queued(struct timerqueue_node *node) { return !RB_EMPTY_NODE(&node->node); } static inline bool timerqueue_node_expires(struct timerqueue_node *node) { return node->expires; } static inline void timerqueue_init_head(struct timerqueue_head *head) { head->rb_root = RB_ROOT_CACHED; } #endif /* _LINUX_TIMERQUEUE_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_IO_H #define _ASM_X86_IO_H /* * This file contains the definitions for the x86 IO instructions * inb/inw/inl/outb/outw/outl and the "string versions" of the same * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing" * versions of the single-IO instructions (inb_p/inw_p/..). * * This file is not meant to be obfuscating: it's just complicated * to (a) handle it all in a way that makes gcc able to optimize it * as well as possible and (b) trying to avoid writing the same thing * over and over again with slight variations and possibly making a * mistake somewhere. */ /* * Thanks to James van Artsdalen for a better timing-fix than * the two short jumps: using outb's to a nonexistent port seems * to guarantee better timings even on fast machines. * * On the other hand, I'd like to be sure of a non-existent port: * I feel a bit unsafe about using 0x80 (should be safe, though) * * Linus */ /* * Bit simplified and optimized by Jan Hubicka * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999. * * isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added, * isa_read[wl] and isa_write[wl] fixed * - Arnaldo Carvalho de Melo <acme@conectiva.com.br> */ #define ARCH_HAS_IOREMAP_WC #define ARCH_HAS_IOREMAP_WT #include <linux/string.h> #include <linux/compiler.h> #include <asm/page.h> #include <asm/early_ioremap.h> #include <asm/pgtable_types.h> #define build_mmio_read(name, size, type, reg, barrier) \ static inline type name(const volatile void __iomem *addr) \ { type ret; asm volatile("mov" size " %1,%0":reg (ret) \ :"m" (*(volatile type __force *)addr) barrier); return ret; } #define build_mmio_write(name, size, type, reg, barrier) \ static inline void name(type val, volatile void __iomem *addr) \ { asm volatile("mov" size " %0,%1": :reg (val), \ "m" (*(volatile type __force *)addr) barrier); } build_mmio_read(readb, "b", unsigned char, "=q", :"memory") build_mmio_read(readw, "w", unsigned short, "=r", :"memory") build_mmio_read(readl, "l", unsigned int, "=r", :"memory") build_mmio_read(__readb, "b", unsigned char, "=q", ) build_mmio_read(__readw, "w", unsigned short, "=r", ) build_mmio_read(__readl, "l", unsigned int, "=r", ) build_mmio_write(writeb, "b", unsigned char, "q", :"memory") build_mmio_write(writew, "w", unsigned short, "r", :"memory") build_mmio_write(writel, "l", unsigned int, "r", :"memory") build_mmio_write(__writeb, "b", unsigned char, "q", ) build_mmio_write(__writew, "w", unsigned short, "r", ) build_mmio_write(__writel, "l", unsigned int, "r", ) #define readb readb #define readw readw #define readl readl #define readb_relaxed(a) __readb(a) #define readw_relaxed(a) __readw(a) #define readl_relaxed(a) __readl(a) #define __raw_readb __readb #define __raw_readw __readw #define __raw_readl __readl #define writeb writeb #define writew writew #define writel writel #define writeb_relaxed(v, a) __writeb(v, a) #define writew_relaxed(v, a) __writew(v, a) #define writel_relaxed(v, a) __writel(v, a) #define __raw_writeb __writeb #define __raw_writew __writew #define __raw_writel __writel #ifdef CONFIG_X86_64 build_mmio_read(readq, "q", u64, "=r", :"memory") build_mmio_read(__readq, "q", u64, "=r", ) build_mmio_write(writeq, "q", u64, "r", :"memory") build_mmio_write(__writeq, "q", u64, "r", ) #define readq_relaxed(a) __readq(a) #define writeq_relaxed(v, a) __writeq(v, a) #define __raw_readq __readq #define __raw_writeq __writeq /* Let people know that we have them */ #define readq readq #define writeq writeq #endif #define ARCH_HAS_VALID_PHYS_ADDR_RANGE extern int valid_phys_addr_range(phys_addr_t addr, size_t size); extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size); /** * virt_to_phys - map virtual addresses to physical * @address: address to remap * * The returned physical address is the physical (CPU) mapping for * the memory address given. It is only valid to use this function on * addresses directly mapped or allocated via kmalloc. * * This function does not give bus mappings for DMA transfers. In * almost all conceivable cases a device driver should not be using * this function */ static inline phys_addr_t virt_to_phys(volatile void *address) { return __pa(address); } #define virt_to_phys virt_to_phys /** * phys_to_virt - map physical address to virtual * @address: address to remap * * The returned virtual address is a current CPU mapping for * the memory address given. It is only valid to use this function on * addresses that have a kernel mapping * * This function does not handle bus mappings for DMA transfers. In * almost all conceivable cases a device driver should not be using * this function */ static inline void *phys_to_virt(phys_addr_t address) { return __va(address); } #define phys_to_virt phys_to_virt /* * Change "struct page" to physical address. */ #define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT) /* * ISA I/O bus memory addresses are 1:1 with the physical address. * However, we truncate the address to unsigned int to avoid undesirable * promitions in legacy drivers. */ static inline unsigned int isa_virt_to_bus(volatile void *address) { return (unsigned int)virt_to_phys(address); } #define isa_bus_to_virt phys_to_virt /* * However PCI ones are not necessarily 1:1 and therefore these interfaces * are forbidden in portable PCI drivers. * * Allow them on x86 for legacy drivers, though. */ #define virt_to_bus virt_to_phys #define bus_to_virt phys_to_virt /* * The default ioremap() behavior is non-cached; if you need something * else, you probably want one of the following. */ extern void __iomem *ioremap_uc(resource_size_t offset, unsigned long size); #define ioremap_uc ioremap_uc extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size); #define ioremap_cache ioremap_cache extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, unsigned long prot_val); #define ioremap_prot ioremap_prot extern void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size); #define ioremap_encrypted ioremap_encrypted /** * ioremap - map bus memory into CPU space * @offset: bus address of the memory * @size: size of the resource to map * * ioremap performs a platform specific sequence of operations to * make bus memory CPU accessible via the readb/readw/readl/writeb/ * writew/writel functions and the other mmio helpers. The returned * address is not guaranteed to be usable directly as a virtual * address. * * If the area you are trying to map is a PCI BAR you should have a * look at pci_iomap(). */ void __iomem *ioremap(resource_size_t offset, unsigned long size); #define ioremap ioremap extern void iounmap(volatile void __iomem *addr); #define iounmap iounmap extern void set_iounmap_nonlazy(void); #ifdef __KERNEL__ void memcpy_fromio(void *, const volatile void __iomem *, size_t); void memcpy_toio(volatile void __iomem *, const void *, size_t); void memset_io(volatile void __iomem *, int, size_t); #define memcpy_fromio memcpy_fromio #define memcpy_toio memcpy_toio #define memset_io memset_io #include <asm-generic/iomap.h> /* * ISA space is 'always mapped' on a typical x86 system, no need to * explicitly ioremap() it. The fact that the ISA IO space is mapped * to PAGE_OFFSET is pure coincidence - it does not mean ISA values * are physical addresses. The following constant pointer can be * used as the IO-area pointer (it can be iounmapped as well, so the * analogy with PCI is quite large): */ #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET)) #endif /* __KERNEL__ */ extern void native_io_delay(void); extern int io_delay_type; extern void io_delay_init(void); #if defined(CONFIG_PARAVIRT) #include <asm/paravirt.h> #else static inline void slow_down_io(void) { native_io_delay(); #ifdef REALLY_SLOW_IO native_io_delay(); native_io_delay(); native_io_delay(); #endif } #endif #ifdef CONFIG_AMD_MEM_ENCRYPT #include <linux/jump_label.h> extern struct static_key_false sev_enable_key; static inline bool sev_key_active(void) { return static_branch_unlikely(&sev_enable_key); } #else /* !CONFIG_AMD_MEM_ENCRYPT */ static inline bool sev_key_active(void) { return false; } #endif /* CONFIG_AMD_MEM_ENCRYPT */ #define BUILDIO(bwl, bw, type) \ static inline void out##bwl(unsigned type value, int port) \ { \ asm volatile("out" #bwl " %" #bw "0, %w1" \ : : "a"(value), "Nd"(port)); \ } \ \ static inline unsigned type in##bwl(int port) \ { \ unsigned type value; \ asm volatile("in" #bwl " %w1, %" #bw "0" \ : "=a"(value) : "Nd"(port)); \ return value; \ } \ \ static inline void out##bwl##_p(unsigned type value, int port) \ { \ out##bwl(value, port); \ slow_down_io(); \ } \ \ static inline unsigned type in##bwl##_p(int port) \ { \ unsigned type value = in##bwl(port); \ slow_down_io(); \ return value; \ } \ \ static inline void outs##bwl(int port, const void *addr, unsigned long count) \ { \ if (sev_key_active()) { \ unsigned type *value = (unsigned type *)addr; \ while (count) { \ out##bwl(*value, port); \ value++; \ count--; \ } \ } else { \ asm volatile("rep; outs" #bwl \ : "+S"(addr), "+c"(count) \ : "d"(port) : "memory"); \ } \ } \ \ static inline void ins##bwl(int port, void *addr, unsigned long count) \ { \ if (sev_key_active()) { \ unsigned type *value = (unsigned type *)addr; \ while (count) { \ *value = in##bwl(port); \ value++; \ count--; \ } \ } else { \ asm volatile("rep; ins" #bwl \ : "+D"(addr), "+c"(count) \ : "d"(port) : "memory"); \ } \ } BUILDIO(b, b, char) BUILDIO(w, w, short) BUILDIO(l, , int) #define inb inb #define inw inw #define inl inl #define inb_p inb_p #define inw_p inw_p #define inl_p inl_p #define insb insb #define insw insw #define insl insl #define outb outb #define outw outw #define outl outl #define outb_p outb_p #define outw_p outw_p #define outl_p outl_p #define outsb outsb #define outsw outsw #define outsl outsl extern void *xlate_dev_mem_ptr(phys_addr_t phys); extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr); #define xlate_dev_mem_ptr xlate_dev_mem_ptr #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr extern int ioremap_change_attr(unsigned long vaddr, unsigned long size, enum page_cache_mode pcm); extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size); #define ioremap_wc ioremap_wc extern void __iomem *ioremap_wt(resource_size_t offset, unsigned long size); #define ioremap_wt ioremap_wt extern bool is_early_ioremap_ptep(pte_t *ptep); #define IO_SPACE_LIMIT 0xffff #include <asm-generic/io.h> #undef PCI_IOBASE #ifdef CONFIG_MTRR extern int __must_check arch_phys_wc_index(int handle); #define arch_phys_wc_index arch_phys_wc_index extern int __must_check arch_phys_wc_add(unsigned long base, unsigned long size); extern void arch_phys_wc_del(int handle); #define arch_phys_wc_add arch_phys_wc_add #endif #ifdef CONFIG_X86_PAT extern int arch_io_reserve_memtype_wc(resource_size_t start, resource_size_t size); extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size); #define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc #endif extern bool arch_memremap_can_ram_remap(resource_size_t offset, unsigned long size, unsigned long flags); #define arch_memremap_can_ram_remap arch_memremap_can_ram_remap extern bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size); /** * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units * @dst: destination, in MMIO space (must be 512-bit aligned) * @src: source * @count: number of 512 bits quantities to submit * * Submit data from kernel space to MMIO space, in units of 512 bits at a * time. Order of access is not guaranteed, nor is a memory barrier * performed afterwards. * * Warning: Do not use this helper unless your driver has checked that the CPU * instruction is supported on the platform. */ static inline void iosubmit_cmds512(void __iomem *dst, const void *src, size_t count) { const u8 *from = src; const u8 *end = from + count * 64; while (from < end) { movdir64b(dst, from); from += 64; } } #endif /* _ASM_X86_IO_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 /* SPDX-License-Identifier: GPL-2.0 */ /* linux/net/inet/arp.h */ #ifndef _ARP_H #define _ARP_H #include <linux/if_arp.h> #include <linux/hash.h> #include <net/neighbour.h> extern struct neigh_table arp_tbl; static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd) { u32 key = *(const u32 *)pkey; u32 val = key ^ hash32_ptr(dev); return val * hash_rnd[0]; } #ifdef CONFIG_INET static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key) { if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) key = INADDR_ANY; return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev); } #else static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key) { return NULL; } #endif static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key) { struct neighbour *n; rcu_read_lock_bh(); n = __ipv4_neigh_lookup_noref(dev, key); if (n && !refcount_inc_not_zero(&n->refcnt)) n = NULL; rcu_read_unlock_bh(); return n; } static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key) { struct neighbour *n; rcu_read_lock_bh(); n = __ipv4_neigh_lookup_noref(dev, key); if (n) { unsigned long now = jiffies; /* avoid dirtying neighbour */ if (READ_ONCE(n->confirmed) != now) WRITE_ONCE(n->confirmed, now); } rcu_read_unlock_bh(); } void arp_init(void); int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg); void arp_send(int type, int ptype, __be32 dest_ip, struct net_device *dev, __be32 src_ip, const unsigned char *dest_hw, const unsigned char *src_hw, const unsigned char *th); int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir); void arp_ifdown(struct net_device *dev); struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, struct net_device *dev, __be32 src_ip, const unsigned char *dest_hw, const unsigned char *src_hw, const unsigned char *target_hw); void arp_xmit(struct sk_buff *skb); #endif /* _ARP_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef RQ_QOS_H #define RQ_QOS_H #include <linux/kernel.h> #include <linux/blkdev.h> #include <linux/blk_types.h> #include <linux/atomic.h> #include <linux/wait.h> #include <linux/blk-mq.h> #include "blk-mq-debugfs.h" struct blk_mq_debugfs_attr; enum rq_qos_id { RQ_QOS_WBT, RQ_QOS_LATENCY, RQ_QOS_COST, }; struct rq_wait { wait_queue_head_t wait; atomic_t inflight; }; struct rq_qos { struct rq_qos_ops *ops; struct request_queue *q; enum rq_qos_id id; struct rq_qos *next; #ifdef CONFIG_BLK_DEBUG_FS struct dentry *debugfs_dir; #endif }; struct rq_qos_ops { void (*throttle)(struct rq_qos *, struct bio *); void (*track)(struct rq_qos *, struct request *, struct bio *); void (*merge)(struct rq_qos *, struct request *, struct bio *); void (*issue)(struct rq_qos *, struct request *); void (*requeue)(struct rq_qos *, struct request *); void (*done)(struct rq_qos *, struct request *); void (*done_bio)(struct rq_qos *, struct bio *); void (*cleanup)(struct rq_qos *, struct bio *); void (*queue_depth_changed)(struct rq_qos *); void (*exit)(struct rq_qos *); const struct blk_mq_debugfs_attr *debugfs_attrs; }; struct rq_depth { unsigned int max_depth; int scale_step; bool scaled_max; unsigned int queue_depth; unsigned int default_depth; }; static inline struct rq_qos *rq_qos_id(struct request_queue *q, enum rq_qos_id id) { struct rq_qos *rqos; for (rqos = q->rq_qos; rqos; rqos = rqos->next) { if (rqos->id == id) break; } return rqos; } static inline struct rq_qos *wbt_rq_qos(struct request_queue *q) { return rq_qos_id(q, RQ_QOS_WBT); } static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q) { return rq_qos_id(q, RQ_QOS_LATENCY); } static inline const char *rq_qos_id_to_name(enum rq_qos_id id) { switch (id) { case RQ_QOS_WBT: return "wbt"; case RQ_QOS_LATENCY: return "latency"; case RQ_QOS_COST: return "cost"; } return "unknown"; } static inline void rq_wait_init(struct rq_wait *rq_wait) { atomic_set(&rq_wait->inflight, 0); init_waitqueue_head(&rq_wait->wait); } static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos) { /* * No IO can be in-flight when adding rqos, so freeze queue, which * is fine since we only support rq_qos for blk-mq queue. * * Reuse ->queue_lock for protecting against other concurrent * rq_qos adding/deleting */ blk_mq_freeze_queue(q); spin_lock_irq(&q->queue_lock); rqos->next = q->rq_qos; q->rq_qos = rqos; spin_unlock_irq(&q->queue_lock); blk_mq_unfreeze_queue(q); if (rqos->ops->debugfs_attrs) blk_mq_debugfs_register_rqos(rqos); } static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) { struct rq_qos **cur; /* * See comment in rq_qos_add() about freezing queue & using * ->queue_lock. */ blk_mq_freeze_queue(q); spin_lock_irq(&q->queue_lock); for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { if (*cur == rqos) { *cur = rqos->next; break; } } spin_unlock_irq(&q->queue_lock); blk_mq_unfreeze_queue(q); blk_mq_debugfs_unregister_rqos(rqos); } typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); void rq_qos_wait(struct rq_wait *rqw, void *private_data, acquire_inflight_cb_t *acquire_inflight_cb, cleanup_cb_t *cleanup_cb); bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); bool rq_depth_scale_up(struct rq_depth *rqd); bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); bool rq_depth_calc_max_depth(struct rq_depth *rqd); void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); void __rq_qos_done(struct rq_qos *rqos, struct request *rq); void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); void __rq_qos_queue_depth_changed(struct rq_qos *rqos); static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) { if (q->rq_qos) __rq_qos_cleanup(q->rq_qos, bio); } static inline void rq_qos_done(struct request_queue *q, struct request *rq) { if (q->rq_qos) __rq_qos_done(q->rq_qos, rq); } static inline void rq_qos_issue(struct request_queue *q, struct request *rq) { if (q->rq_qos) __rq_qos_issue(q->rq_qos, rq); } static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) { if (q->rq_qos) __rq_qos_requeue(q->rq_qos, rq); } static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio) { if (q->rq_qos) __rq_qos_done_bio(q->rq_qos, bio); } static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) { /* * BIO_TRACKED lets controllers know that a bio went through the * normal rq_qos path. */ bio_set_flag(bio, BIO_TRACKED); if (q->rq_qos) __rq_qos_throttle(q->rq_qos, bio); } static inline void rq_qos_track(struct request_queue *q, struct request *rq, struct bio *bio) { if (q->rq_qos) __rq_qos_track(q->rq_qos, rq, bio); } static inline void rq_qos_merge(struct request_queue *q, struct request *rq, struct bio *bio) { if (q->rq_qos) __rq_qos_merge(q->rq_qos, rq, bio); } static inline void rq_qos_queue_depth_changed(struct request_queue *q) { if (q->rq_qos) __rq_qos_queue_depth_changed(q->rq_qos); } void rq_qos_exit(struct request_queue *); #endif
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2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 // SPDX-License-Identifier: GPL-2.0+ /* * linux/fs/jbd2/transaction.c * * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 * * Copyright 1998 Red Hat corp --- All Rights Reserved * * Generic filesystem transaction handling code; part of the ext2fs * journaling system. * * This file manages transactions (compound commits managed by the * journaling code) and handles (individual atomic operations by the * filesystem). */ #include <linux/time.h> #include <linux/fs.h> #include <linux/jbd2.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/timer.h> #include <linux/mm.h> #include <linux/highmem.h> #include <linux/hrtimer.h> #include <linux/backing-dev.h> #include <linux/bug.h> #include <linux/module.h> #include <linux/sched/mm.h> #include <trace/events/jbd2.h> static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); static void __jbd2_journal_unfile_buffer(struct journal_head *jh); static struct kmem_cache *transaction_cache; int __init jbd2_journal_init_transaction_cache(void) { J_ASSERT(!transaction_cache); transaction_cache = kmem_cache_create("jbd2_transaction_s", sizeof(transaction_t), 0, SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY, NULL); if (!transaction_cache) { pr_emerg("JBD2: failed to create transaction cache\n"); return -ENOMEM; } return 0; } void jbd2_journal_destroy_transaction_cache(void) { kmem_cache_destroy(transaction_cache); transaction_cache = NULL; } void jbd2_journal_free_transaction(transaction_t *transaction) { if (unlikely(ZERO_OR_NULL_PTR(transaction))) return; kmem_cache_free(transaction_cache, transaction); } /* * Base amount of descriptor blocks we reserve for each transaction. */ static int jbd2_descriptor_blocks_per_trans(journal_t *journal) { int tag_space = journal->j_blocksize - sizeof(journal_header_t); int tags_per_block; /* Subtract UUID */ tag_space -= 16; if (jbd2_journal_has_csum_v2or3(journal)) tag_space -= sizeof(struct jbd2_journal_block_tail); /* Commit code leaves a slack space of 16 bytes at the end of block */ tags_per_block = (tag_space - 16) / journal_tag_bytes(journal); /* * Revoke descriptors are accounted separately so we need to reserve * space for commit block and normal transaction descriptor blocks. */ return 1 + DIV_ROUND_UP(journal->j_max_transaction_buffers, tags_per_block); } /* * jbd2_get_transaction: obtain a new transaction_t object. * * Simply initialise a new transaction. Initialize it in * RUNNING state and add it to the current journal (which should not * have an existing running transaction: we only make a new transaction * once we have started to commit the old one). * * Preconditions: * The journal MUST be locked. We don't perform atomic mallocs on the * new transaction and we can't block without protecting against other * processes trying to touch the journal while it is in transition. * */ static void jbd2_get_transaction(journal_t *journal, transaction_t *transaction) { transaction->t_journal = journal; transaction->t_state = T_RUNNING; transaction->t_start_time = ktime_get(); transaction->t_tid = journal->j_transaction_sequence++; transaction->t_expires = jiffies + journal->j_commit_interval; spin_lock_init(&transaction->t_handle_lock); atomic_set(&transaction->t_updates, 0); atomic_set(&transaction->t_outstanding_credits, jbd2_descriptor_blocks_per_trans(journal) + atomic_read(&journal->j_reserved_credits)); atomic_set(&transaction->t_outstanding_revokes, 0); atomic_set(&transaction->t_handle_count, 0); INIT_LIST_HEAD(&transaction->t_inode_list); INIT_LIST_HEAD(&transaction->t_private_list); /* Set up the commit timer for the new transaction. */ journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); add_timer(&journal->j_commit_timer); J_ASSERT(journal->j_running_transaction == NULL); journal->j_running_transaction = transaction; transaction->t_max_wait = 0; transaction->t_start = jiffies; transaction->t_requested = 0; } /* * Handle management. * * A handle_t is an object which represents a single atomic update to a * filesystem, and which tracks all of the modifications which form part * of that one update. */ /* * Update transaction's maximum wait time, if debugging is enabled. * * In order for t_max_wait to be reliable, it must be protected by a * lock. But doing so will mean that start_this_handle() can not be * run in parallel on SMP systems, which limits our scalability. So * unless debugging is enabled, we no longer update t_max_wait, which * means that maximum wait time reported by the jbd2_run_stats * tracepoint will always be zero. */ static inline void update_t_max_wait(transaction_t *transaction, unsigned long ts) { #ifdef CONFIG_JBD2_DEBUG if (jbd2_journal_enable_debug && time_after(transaction->t_start, ts)) { ts = jbd2_time_diff(ts, transaction->t_start); spin_lock(&transaction->t_handle_lock); if (ts > transaction->t_max_wait) transaction->t_max_wait = ts; spin_unlock(&transaction->t_handle_lock); } #endif } /* * Wait until running transaction passes to T_FLUSH state and new transaction * can thus be started. Also starts the commit if needed. The function expects * running transaction to exist and releases j_state_lock. */ static void wait_transaction_locked(journal_t *journal) __releases(journal->j_state_lock) { DEFINE_WAIT(wait); int need_to_start; tid_t tid = journal->j_running_transaction->t_tid; prepare_to_wait(&journal->j_wait_transaction_locked, &wait, TASK_UNINTERRUPTIBLE); need_to_start = !tid_geq(journal->j_commit_request, tid); read_unlock(&journal->j_state_lock); if (need_to_start) jbd2_log_start_commit(journal, tid); jbd2_might_wait_for_commit(journal); schedule(); finish_wait(&journal->j_wait_transaction_locked, &wait); } /* * Wait until running transaction transitions from T_SWITCH to T_FLUSH * state and new transaction can thus be started. The function releases * j_state_lock. */ static void wait_transaction_switching(journal_t *journal) __releases(journal->j_state_lock) { DEFINE_WAIT(wait); if (WARN_ON(!journal->j_running_transaction || journal->j_running_transaction->t_state != T_SWITCH)) { read_unlock(&journal->j_state_lock); return; } prepare_to_wait(&journal->j_wait_transaction_locked, &wait, TASK_UNINTERRUPTIBLE); read_unlock(&journal->j_state_lock); /* * We don't call jbd2_might_wait_for_commit() here as there's no * waiting for outstanding handles happening anymore in T_SWITCH state * and handling of reserved handles actually relies on that for * correctness. */ schedule(); finish_wait(&journal->j_wait_transaction_locked, &wait); } static void sub_reserved_credits(journal_t *journal, int blocks) { atomic_sub(blocks, &journal->j_reserved_credits); wake_up(&journal->j_wait_reserved); } /* * Wait until we can add credits for handle to the running transaction. Called * with j_state_lock held for reading. Returns 0 if handle joined the running * transaction. Returns 1 if we had to wait, j_state_lock is dropped, and * caller must retry. */ static int add_transaction_credits(journal_t *journal, int blocks, int rsv_blocks) { transaction_t *t = journal->j_running_transaction; int needed; int total = blocks + rsv_blocks; /* * If the current transaction is locked down for commit, wait * for the lock to be released. */ if (t->t_state != T_RUNNING) { WARN_ON_ONCE(t->t_state >= T_FLUSH); wait_transaction_locked(journal); return 1; } /* * If there is not enough space left in the log to write all * potential buffers requested by this operation, we need to * stall pending a log checkpoint to free some more log space. */ needed = atomic_add_return(total, &t->t_outstanding_credits); if (needed > journal->j_max_transaction_buffers) { /* * If the current transaction is already too large, * then start to commit it: we can then go back and * attach this handle to a new transaction. */ atomic_sub(total, &t->t_outstanding_credits); /* * Is the number of reserved credits in the current transaction too * big to fit this handle? Wait until reserved credits are freed. */ if (atomic_read(&journal->j_reserved_credits) + total > journal->j_max_transaction_buffers) { read_unlock(&journal->j_state_lock); jbd2_might_wait_for_commit(journal); wait_event(journal->j_wait_reserved, atomic_read(&journal->j_reserved_credits) + total <= journal->j_max_transaction_buffers); return 1; } wait_transaction_locked(journal); return 1; } /* * The commit code assumes that it can get enough log space * without forcing a checkpoint. This is *critical* for * correctness: a checkpoint of a buffer which is also * associated with a committing transaction creates a deadlock, * so commit simply cannot force through checkpoints. * * We must therefore ensure the necessary space in the journal * *before* starting to dirty potentially checkpointed buffers * in the new transaction. */ if (jbd2_log_space_left(journal) < journal->j_max_transaction_buffers) { atomic_sub(total, &t->t_outstanding_credits); read_unlock(&journal->j_state_lock); jbd2_might_wait_for_commit(journal); write_lock(&journal->j_state_lock); if (jbd2_log_space_left(journal) < journal->j_max_transaction_buffers) __jbd2_log_wait_for_space(journal); write_unlock(&journal->j_state_lock); return 1; } /* No reservation? We are done... */ if (!rsv_blocks) return 0; needed = atomic_add_return(rsv_blocks, &journal->j_reserved_credits); /* We allow at most half of a transaction to be reserved */ if (needed > journal->j_max_transaction_buffers / 2) { sub_reserved_credits(journal, rsv_blocks); atomic_sub(total, &t->t_outstanding_credits); read_unlock(&journal->j_state_lock); jbd2_might_wait_for_commit(journal); wait_event(journal->j_wait_reserved, atomic_read(&journal->j_reserved_credits) + rsv_blocks <= journal->j_max_transaction_buffers / 2); return 1; } return 0; } /* * start_this_handle: Given a handle, deal with any locking or stalling * needed to make sure that there is enough journal space for the handle * to begin. Attach the handle to a transaction and set up the * transaction's buffer credits. */ static int start_this_handle(journal_t *journal, handle_t *handle, gfp_t gfp_mask) { transaction_t *transaction, *new_transaction = NULL; int blocks = handle->h_total_credits; int rsv_blocks = 0; unsigned long ts = jiffies; if (handle->h_rsv_handle) rsv_blocks = handle->h_rsv_handle->h_total_credits; /* * Limit the number of reserved credits to 1/2 of maximum transaction * size and limit the number of total credits to not exceed maximum * transaction size per operation. */ if ((rsv_blocks > journal->j_max_transaction_buffers / 2) || (rsv_blocks + blocks > journal->j_max_transaction_buffers)) { printk(KERN_ERR "JBD2: %s wants too many credits " "credits:%d rsv_credits:%d max:%d\n", current->comm, blocks, rsv_blocks, journal->j_max_transaction_buffers); WARN_ON(1); return -ENOSPC; } alloc_transaction: /* * This check is racy but it is just an optimization of allocating new * transaction early if there are high chances we'll need it. If we * guess wrong, we'll retry or free unused transaction. */ if (!data_race(journal->j_running_transaction)) { /* * If __GFP_FS is not present, then we may be being called from * inside the fs writeback layer, so we MUST NOT fail. */ if ((gfp_mask & __GFP_FS) == 0) gfp_mask |= __GFP_NOFAIL; new_transaction = kmem_cache_zalloc(transaction_cache, gfp_mask); if (!new_transaction) return -ENOMEM; } jbd_debug(3, "New handle %p going live.\n", handle); /* * We need to hold j_state_lock until t_updates has been incremented, * for proper journal barrier handling */ repeat: read_lock(&journal->j_state_lock); BUG_ON(journal->j_flags & JBD2_UNMOUNT); if (is_journal_aborted(journal) || (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { read_unlock(&journal->j_state_lock); jbd2_journal_free_transaction(new_transaction); return -EROFS; } /* * Wait on the journal's transaction barrier if necessary. Specifically * we allow reserved handles to proceed because otherwise commit could * deadlock on page writeback not being able to complete. */ if (!handle->h_reserved && journal->j_barrier_count) { read_unlock(&journal->j_state_lock); wait_event(journal->j_wait_transaction_locked, journal->j_barrier_count == 0); goto repeat; } if (!journal->j_running_transaction) { read_unlock(&journal->j_state_lock); if (!new_transaction) goto alloc_transaction; write_lock(&journal->j_state_lock); if (!journal->j_running_transaction && (handle->h_reserved || !journal->j_barrier_count)) { jbd2_get_transaction(journal, new_transaction); new_transaction = NULL; } write_unlock(&journal->j_state_lock); goto repeat; } transaction = journal->j_running_transaction; if (!handle->h_reserved) { /* We may have dropped j_state_lock - restart in that case */ if (add_transaction_credits(journal, blocks, rsv_blocks)) goto repeat; } else { /* * We have handle reserved so we are allowed to join T_LOCKED * transaction and we don't have to check for transaction size * and journal space. But we still have to wait while running * transaction is being switched to a committing one as it * won't wait for any handles anymore. */ if (transaction->t_state == T_SWITCH) { wait_transaction_switching(journal); goto repeat; } sub_reserved_credits(journal, blocks); handle->h_reserved = 0; } /* OK, account for the buffers that this operation expects to * use and add the handle to the running transaction. */ update_t_max_wait(transaction, ts); handle->h_transaction = transaction; handle->h_requested_credits = blocks; handle->h_revoke_credits_requested = handle->h_revoke_credits; handle->h_start_jiffies = jiffies; atomic_inc(&transaction->t_updates); atomic_inc(&transaction->t_handle_count); jbd_debug(4, "Handle %p given %d credits (total %d, free %lu)\n", handle, blocks, atomic_read(&transaction->t_outstanding_credits), jbd2_log_space_left(journal)); read_unlock(&journal->j_state_lock); current->journal_info = handle; rwsem_acquire_read(&journal->j_trans_commit_map, 0, 0, _THIS_IP_); jbd2_journal_free_transaction(new_transaction); /* * Ensure that no allocations done while the transaction is open are * going to recurse back to the fs layer. */ handle->saved_alloc_context = memalloc_nofs_save(); return 0; } /* Allocate a new handle. This should probably be in a slab... */ static handle_t *new_handle(int nblocks) { handle_t *handle = jbd2_alloc_handle(GFP_NOFS); if (!handle) return NULL; handle->h_total_credits = nblocks; handle->h_ref = 1; return handle; } handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, int revoke_records, gfp_t gfp_mask, unsigned int type, unsigned int line_no) { handle_t *handle = journal_current_handle(); int err; if (!journal) return ERR_PTR(-EROFS); if (handle) { J_ASSERT(handle->h_transaction->t_journal == journal); handle->h_ref++; return handle; } nblocks += DIV_ROUND_UP(revoke_records, journal->j_revoke_records_per_block); handle = new_handle(nblocks); if (!handle) return ERR_PTR(-ENOMEM); if (rsv_blocks) { handle_t *rsv_handle; rsv_handle = new_handle(rsv_blocks); if (!rsv_handle) { jbd2_free_handle(handle); return ERR_PTR(-ENOMEM); } rsv_handle->h_reserved = 1; rsv_handle->h_journal = journal; handle->h_rsv_handle = rsv_handle; } handle->h_revoke_credits = revoke_records; err = start_this_handle(journal, handle, gfp_mask); if (err < 0) { if (handle->h_rsv_handle) jbd2_free_handle(handle->h_rsv_handle); jbd2_free_handle(handle); return ERR_PTR(err); } handle->h_type = type; handle->h_line_no = line_no; trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, handle->h_transaction->t_tid, type, line_no, nblocks); return handle; } EXPORT_SYMBOL(jbd2__journal_start); /** * jbd2_journal_start() - Obtain a new handle. * @journal: Journal to start transaction on. * @nblocks: number of block buffer we might modify * * We make sure that the transaction can guarantee at least nblocks of * modified buffers in the log. We block until the log can guarantee * that much space. Additionally, if rsv_blocks > 0, we also create another * handle with rsv_blocks reserved blocks in the journal. This handle is * stored in h_rsv_handle. It is not attached to any particular transaction * and thus doesn't block transaction commit. If the caller uses this reserved * handle, it has to set h_rsv_handle to NULL as otherwise jbd2_journal_stop() * on the parent handle will dispose the reserved one. Reserved handle has to * be converted to a normal handle using jbd2_journal_start_reserved() before * it can be used. * * Return a pointer to a newly allocated handle, or an ERR_PTR() value * on failure. */ handle_t *jbd2_journal_start(journal_t *journal, int nblocks) { return jbd2__journal_start(journal, nblocks, 0, 0, GFP_NOFS, 0, 0); } EXPORT_SYMBOL(jbd2_journal_start); static void __jbd2_journal_unreserve_handle(handle_t *handle, transaction_t *t) { journal_t *journal = handle->h_journal; WARN_ON(!handle->h_reserved); sub_reserved_credits(journal, handle->h_total_credits); if (t) atomic_sub(handle->h_total_credits, &t->t_outstanding_credits); } void jbd2_journal_free_reserved(handle_t *handle) { journal_t *journal = handle->h_journal; /* Get j_state_lock to pin running transaction if it exists */ read_lock(&journal->j_state_lock); __jbd2_journal_unreserve_handle(handle, journal->j_running_transaction); read_unlock(&journal->j_state_lock); jbd2_free_handle(handle); } EXPORT_SYMBOL(jbd2_journal_free_reserved); /** * jbd2_journal_start_reserved() - start reserved handle * @handle: handle to start * @type: for handle statistics * @line_no: for handle statistics * * Start handle that has been previously reserved with jbd2_journal_reserve(). * This attaches @handle to the running transaction (or creates one if there's * not transaction running). Unlike jbd2_journal_start() this function cannot * block on journal commit, checkpointing, or similar stuff. It can block on * memory allocation or frozen journal though. * * Return 0 on success, non-zero on error - handle is freed in that case. */ int jbd2_journal_start_reserved(handle_t *handle, unsigned int type, unsigned int line_no) { journal_t *journal = handle->h_journal; int ret = -EIO; if (WARN_ON(!handle->h_reserved)) { /* Someone passed in normal handle? Just stop it. */ jbd2_journal_stop(handle); return ret; } /* * Usefulness of mixing of reserved and unreserved handles is * questionable. So far nobody seems to need it so just error out. */ if (WARN_ON(current->journal_info)) { jbd2_journal_free_reserved(handle); return ret; } handle->h_journal = NULL; /* * GFP_NOFS is here because callers are likely from writeback or * similarly constrained call sites */ ret = start_this_handle(journal, handle, GFP_NOFS); if (ret < 0) { handle->h_journal = journal; jbd2_journal_free_reserved(handle); return ret; } handle->h_type = type; handle->h_line_no = line_no; trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, handle->h_transaction->t_tid, type, line_no, handle->h_total_credits); return 0; } EXPORT_SYMBOL(jbd2_journal_start_reserved); /** * jbd2_journal_extend() - extend buffer credits. * @handle: handle to 'extend' * @nblocks: nr blocks to try to extend by. * @revoke_records: number of revoke records to try to extend by. * * Some transactions, such as large extends and truncates, can be done * atomically all at once or in several stages. The operation requests * a credit for a number of buffer modifications in advance, but can * extend its credit if it needs more. * * jbd2_journal_extend tries to give the running handle more buffer credits. * It does not guarantee that allocation - this is a best-effort only. * The calling process MUST be able to deal cleanly with a failure to * extend here. * * Return 0 on success, non-zero on failure. * * return code < 0 implies an error * return code > 0 implies normal transaction-full status. */ int jbd2_journal_extend(handle_t *handle, int nblocks, int revoke_records) { transaction_t *transaction = handle->h_transaction; journal_t *journal; int result; int wanted; if (is_handle_aborted(handle)) return -EROFS; journal = transaction->t_journal; result = 1; read_lock(&journal->j_state_lock); /* Don't extend a locked-down transaction! */ if (transaction->t_state != T_RUNNING) { jbd_debug(3, "denied handle %p %d blocks: " "transaction not running\n", handle, nblocks); goto error_out; } nblocks += DIV_ROUND_UP( handle->h_revoke_credits_requested + revoke_records, journal->j_revoke_records_per_block) - DIV_ROUND_UP( handle->h_revoke_credits_requested, journal->j_revoke_records_per_block); spin_lock(&transaction->t_handle_lock); wanted = atomic_add_return(nblocks, &transaction->t_outstanding_credits); if (wanted > journal->j_max_transaction_buffers) { jbd_debug(3, "denied handle %p %d blocks: " "transaction too large\n", handle, nblocks); atomic_sub(nblocks, &transaction->t_outstanding_credits); goto unlock; } trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev, transaction->t_tid, handle->h_type, handle->h_line_no, handle->h_total_credits, nblocks); handle->h_total_credits += nblocks; handle->h_requested_credits += nblocks; handle->h_revoke_credits += revoke_records; handle->h_revoke_credits_requested += revoke_records; result = 0; jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); unlock: spin_unlock(&transaction->t_handle_lock); error_out: read_unlock(&journal->j_state_lock); return result; } static void stop_this_handle(handle_t *handle) { transaction_t *transaction = handle->h_transaction; journal_t *journal = transaction->t_journal; int revokes; J_ASSERT(journal_current_handle() == handle); J_ASSERT(atomic_read(&transaction->t_updates) > 0); current->journal_info = NULL; /* * Subtract necessary revoke descriptor blocks from handle credits. We * take care to account only for revoke descriptor blocks the * transaction will really need as large sequences of transactions with * small numbers of revokes are relatively common. */ revokes = handle->h_revoke_credits_requested - handle->h_revoke_credits; if (revokes) { int t_revokes, revoke_descriptors; int rr_per_blk = journal->j_revoke_records_per_block; WARN_ON_ONCE(DIV_ROUND_UP(revokes, rr_per_blk) > handle->h_total_credits); t_revokes = atomic_add_return(revokes, &transaction->t_outstanding_revokes); revoke_descriptors = DIV_ROUND_UP(t_revokes, rr_per_blk) - DIV_ROUND_UP(t_revokes - revokes, rr_per_blk); handle->h_total_credits -= revoke_descriptors; } atomic_sub(handle->h_total_credits, &transaction->t_outstanding_credits); if (handle->h_rsv_handle) __jbd2_journal_unreserve_handle(handle->h_rsv_handle, transaction); if (atomic_dec_and_test(&transaction->t_updates)) wake_up(&journal->j_wait_updates); rwsem_release(&journal->j_trans_commit_map, _THIS_IP_); /* * Scope of the GFP_NOFS context is over here and so we can restore the * original alloc context. */ memalloc_nofs_restore(handle->saved_alloc_context); } /** * jbd2__journal_restart() - restart a handle . * @handle: handle to restart * @nblocks: nr credits requested * @revoke_records: number of revoke record credits requested * @gfp_mask: memory allocation flags (for start_this_handle) * * Restart a handle for a multi-transaction filesystem * operation. * * If the jbd2_journal_extend() call above fails to grant new buffer credits * to a running handle, a call to jbd2_journal_restart will commit the * handle's transaction so far and reattach the handle to a new * transaction capable of guaranteeing the requested number of * credits. We preserve reserved handle if there's any attached to the * passed in handle. */ int jbd2__journal_restart(handle_t *handle, int nblocks, int revoke_records, gfp_t gfp_mask) { transaction_t *transaction = handle->h_transaction; journal_t *journal; tid_t tid; int need_to_start; int ret; /* If we've had an abort of any type, don't even think about * actually doing the restart! */ if (is_handle_aborted(handle)) return 0; journal = transaction->t_journal; tid = transaction->t_tid; /* * First unlink the handle from its current transaction, and start the * commit on that. */ jbd_debug(2, "restarting handle %p\n", handle); stop_this_handle(handle); handle->h_transaction = NULL; /* * TODO: If we use READ_ONCE / WRITE_ONCE for j_commit_request we can * get rid of pointless j_state_lock traffic like this. */ read_lock(&journal->j_state_lock); need_to_start = !tid_geq(journal->j_commit_request, tid); read_unlock(&journal->j_state_lock); if (need_to_start) jbd2_log_start_commit(journal, tid); handle->h_total_credits = nblocks + DIV_ROUND_UP(revoke_records, journal->j_revoke_records_per_block); handle->h_revoke_credits = revoke_records; ret = start_this_handle(journal, handle, gfp_mask); trace_jbd2_handle_restart(journal->j_fs_dev->bd_dev, ret ? 0 : handle->h_transaction->t_tid, handle->h_type, handle->h_line_no, handle->h_total_credits); return ret; } EXPORT_SYMBOL(jbd2__journal_restart); int jbd2_journal_restart(handle_t *handle, int nblocks) { return jbd2__journal_restart(handle, nblocks, 0, GFP_NOFS); } EXPORT_SYMBOL(jbd2_journal_restart); /** * jbd2_journal_lock_updates () - establish a transaction barrier. * @journal: Journal to establish a barrier on. * * This locks out any further updates from being started, and blocks * until all existing updates have completed, returning only once the * journal is in a quiescent state with no updates running. * * The journal lock should not be held on entry. */ void jbd2_journal_lock_updates(journal_t *journal) { DEFINE_WAIT(wait); jbd2_might_wait_for_commit(journal); write_lock(&journal->j_state_lock); ++journal->j_barrier_count; /* Wait until there are no reserved handles */ if (atomic_read(&journal->j_reserved_credits)) { write_unlock(&journal->j_state_lock); wait_event(journal->j_wait_reserved, atomic_read(&journal->j_reserved_credits) == 0); write_lock(&journal->j_state_lock); } /* Wait until there are no running updates */ while (1) { transaction_t *transaction = journal->j_running_transaction; if (!transaction) break; spin_lock(&transaction->t_handle_lock); prepare_to_wait(&journal->j_wait_updates, &wait, TASK_UNINTERRUPTIBLE); if (!atomic_read(&transaction->t_updates)) { spin_unlock(&transaction->t_handle_lock); finish_wait(&journal->j_wait_updates, &wait); break; } spin_unlock(&transaction->t_handle_lock); write_unlock(&journal->j_state_lock); schedule(); finish_wait(&journal->j_wait_updates, &wait); write_lock(&journal->j_state_lock); } write_unlock(&journal->j_state_lock); /* * We have now established a barrier against other normal updates, but * we also need to barrier against other jbd2_journal_lock_updates() calls * to make sure that we serialise special journal-locked operations * too. */ mutex_lock(&journal->j_barrier); } /** * jbd2_journal_unlock_updates () - release barrier * @journal: Journal to release the barrier on. * * Release a transaction barrier obtained with jbd2_journal_lock_updates(). * * Should be called without the journal lock held. */ void jbd2_journal_unlock_updates (journal_t *journal) { J_ASSERT(journal->j_barrier_count != 0); mutex_unlock(&journal->j_barrier); write_lock(&journal->j_state_lock); --journal->j_barrier_count; write_unlock(&journal->j_state_lock); wake_up(&journal->j_wait_transaction_locked); } static void warn_dirty_buffer(struct buffer_head *bh) { printk(KERN_WARNING "JBD2: Spotted dirty metadata buffer (dev = %pg, blocknr = %llu). " "There's a risk of filesystem corruption in case of system " "crash.\n", bh->b_bdev, (unsigned long long)bh->b_blocknr); } /* Call t_frozen trigger and copy buffer data into jh->b_frozen_data. */ static void jbd2_freeze_jh_data(struct journal_head *jh) { struct page *page; int offset; char *source; struct buffer_head *bh = jh2bh(jh); J_EXPECT_JH(jh, buffer_uptodate(bh), "Possible IO failure.\n"); page = bh->b_page; offset = offset_in_page(bh->b_data); source = kmap_atomic(page); /* Fire data frozen trigger just before we copy the data */ jbd2_buffer_frozen_trigger(jh, source + offset, jh->b_triggers); memcpy(jh->b_frozen_data, source + offset, bh->b_size); kunmap_atomic(source); /* * Now that the frozen data is saved off, we need to store any matching * triggers. */ jh->b_frozen_triggers = jh->b_triggers; } /* * If the buffer is already part of the current transaction, then there * is nothing we need to do. If it is already part of a prior * transaction which we are still committing to disk, then we need to * make sure that we do not overwrite the old copy: we do copy-out to * preserve the copy going to disk. We also account the buffer against * the handle's metadata buffer credits (unless the buffer is already * part of the transaction, that is). * */ static int do_get_write_access(handle_t *handle, struct journal_head *jh, int force_copy) { struct buffer_head *bh; transaction_t *transaction = handle->h_transaction; journal_t *journal; int error; char *frozen_buffer = NULL; unsigned long start_lock, time_lock; journal = transaction->t_journal; jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy); JBUFFER_TRACE(jh, "entry"); repeat: bh = jh2bh(jh); /* @@@ Need to check for errors here at some point. */ start_lock = jiffies; lock_buffer(bh); spin_lock(&jh->b_state_lock); /* If it takes too long to lock the buffer, trace it */ time_lock = jbd2_time_diff(start_lock, jiffies); if (time_lock > HZ/10) trace_jbd2_lock_buffer_stall(bh->b_bdev->bd_dev, jiffies_to_msecs(time_lock)); /* We now hold the buffer lock so it is safe to query the buffer * state. Is the buffer dirty? * * If so, there are two possibilities. The buffer may be * non-journaled, and undergoing a quite legitimate writeback. * Otherwise, it is journaled, and we don't expect dirty buffers * in that state (the buffers should be marked JBD_Dirty * instead.) So either the IO is being done under our own * control and this is a bug, or it's a third party IO such as * dump(8) (which may leave the buffer scheduled for read --- * ie. locked but not dirty) or tune2fs (which may actually have * the buffer dirtied, ugh.) */ if (buffer_dirty(bh)) { /* * First question: is this buffer already part of the current * transaction or the existing committing transaction? */ if (jh->b_transaction) { J_ASSERT_JH(jh, jh->b_transaction == transaction || jh->b_transaction == journal->j_committing_transaction); if (jh->b_next_transaction) J_ASSERT_JH(jh, jh->b_next_transaction == transaction); warn_dirty_buffer(bh); } /* * In any case we need to clean the dirty flag and we must * do it under the buffer lock to be sure we don't race * with running write-out. */ JBUFFER_TRACE(jh, "Journalling dirty buffer"); clear_buffer_dirty(bh); set_buffer_jbddirty(bh); } unlock_buffer(bh); error = -EROFS; if (is_handle_aborted(handle)) { spin_unlock(&jh->b_state_lock); goto out; } error = 0; /* * The buffer is already part of this transaction if b_transaction or * b_next_transaction points to it */ if (jh->b_transaction == transaction || jh->b_next_transaction == transaction) goto done; /* * this is the first time this transaction is touching this buffer, * reset the modified flag */ jh->b_modified = 0; /* * If the buffer is not journaled right now, we need to make sure it * doesn't get written to disk before the caller actually commits the * new data */ if (!jh->b_transaction) { JBUFFER_TRACE(jh, "no transaction"); J_ASSERT_JH(jh, !jh->b_next_transaction); JBUFFER_TRACE(jh, "file as BJ_Reserved"); /* * Make sure all stores to jh (b_modified, b_frozen_data) are * visible before attaching it to the running transaction. * Paired with barrier in jbd2_write_access_granted() */ smp_wmb(); spin_lock(&journal->j_list_lock); __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); spin_unlock(&journal->j_list_lock); goto done; } /* * If there is already a copy-out version of this buffer, then we don't * need to make another one */ if (jh->b_frozen_data) { JBUFFER_TRACE(jh, "has frozen data"); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); goto attach_next; } JBUFFER_TRACE(jh, "owned by older transaction"); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); J_ASSERT_JH(jh, jh->b_transaction == journal->j_committing_transaction); /* * There is one case we have to be very careful about. If the * committing transaction is currently writing this buffer out to disk * and has NOT made a copy-out, then we cannot modify the buffer * contents at all right now. The essence of copy-out is that it is * the extra copy, not the primary copy, which gets journaled. If the * primary copy is already going to disk then we cannot do copy-out * here. */ if (buffer_shadow(bh)) { JBUFFER_TRACE(jh, "on shadow: sleep"); spin_unlock(&jh->b_state_lock); wait_on_bit_io(&bh->b_state, BH_Shadow, TASK_UNINTERRUPTIBLE); goto repeat; } /* * Only do the copy if the currently-owning transaction still needs it. * If buffer isn't on BJ_Metadata list, the committing transaction is * past that stage (here we use the fact that BH_Shadow is set under * bh_state lock together with refiling to BJ_Shadow list and at this * point we know the buffer doesn't have BH_Shadow set). * * Subtle point, though: if this is a get_undo_access, then we will be * relying on the frozen_data to contain the new value of the * committed_data record after the transaction, so we HAVE to force the * frozen_data copy in that case. */ if (jh->b_jlist == BJ_Metadata || force_copy) { JBUFFER_TRACE(jh, "generate frozen data"); if (!frozen_buffer) { JBUFFER_TRACE(jh, "allocate memory for buffer"); spin_unlock(&jh->b_state_lock); frozen_buffer = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS | __GFP_NOFAIL); goto repeat; } jh->b_frozen_data = frozen_buffer; frozen_buffer = NULL; jbd2_freeze_jh_data(jh); } attach_next: /* * Make sure all stores to jh (b_modified, b_frozen_data) are visible * before attaching it to the running transaction. Paired with barrier * in jbd2_write_access_granted() */ smp_wmb(); jh->b_next_transaction = transaction; done: spin_unlock(&jh->b_state_lock); /* * If we are about to journal a buffer, then any revoke pending on it is * no longer valid */ jbd2_journal_cancel_revoke(handle, jh); out: if (unlikely(frozen_buffer)) /* It's usually NULL */ jbd2_free(frozen_buffer, bh->b_size); JBUFFER_TRACE(jh, "exit"); return error; } /* Fast check whether buffer is already attached to the required transaction */ static bool jbd2_write_access_granted(handle_t *handle, struct buffer_head *bh, bool undo) { struct journal_head *jh; bool ret = false; /* Dirty buffers require special handling... */ if (buffer_dirty(bh)) return false; /* * RCU protects us from dereferencing freed pages. So the checks we do * are guaranteed not to oops. However the jh slab object can get freed * & reallocated while we work with it. So we have to be careful. When * we see jh attached to the running transaction, we know it must stay * so until the transaction is committed. Thus jh won't be freed and * will be attached to the same bh while we run. However it can * happen jh gets freed, reallocated, and attached to the transaction * just after we get pointer to it from bh. So we have to be careful * and recheck jh still belongs to our bh before we return success. */ rcu_read_lock(); if (!buffer_jbd(bh)) goto out; /* This should be bh2jh() but that doesn't work with inline functions */ jh = READ_ONCE(bh->b_private); if (!jh) goto out; /* For undo access buffer must have data copied */ if (undo && !jh->b_committed_data) goto out; if (READ_ONCE(jh->b_transaction) != handle->h_transaction && READ_ONCE(jh->b_next_transaction) != handle->h_transaction) goto out; /* * There are two reasons for the barrier here: * 1) Make sure to fetch b_bh after we did previous checks so that we * detect when jh went through free, realloc, attach to transaction * while we were checking. Paired with implicit barrier in that path. * 2) So that access to bh done after jbd2_write_access_granted() * doesn't get reordered and see inconsistent state of concurrent * do_get_write_access(). */ smp_mb(); if (unlikely(jh->b_bh != bh)) goto out; ret = true; out: rcu_read_unlock(); return ret; } /** * jbd2_journal_get_write_access() - notify intent to modify a buffer * for metadata (not data) update. * @handle: transaction to add buffer modifications to * @bh: bh to be used for metadata writes * * Returns: error code or 0 on success. * * In full data journalling mode the buffer may be of type BJ_AsyncData, * because we're ``write()ing`` a buffer which is also part of a shared mapping. */ int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) { struct journal_head *jh; int rc; if (is_handle_aborted(handle)) return -EROFS; if (jbd2_write_access_granted(handle, bh, false)) return 0; jh = jbd2_journal_add_journal_head(bh); /* We do not want to get caught playing with fields which the * log thread also manipulates. Make sure that the buffer * completes any outstanding IO before proceeding. */ rc = do_get_write_access(handle, jh, 0); jbd2_journal_put_journal_head(jh); return rc; } /* * When the user wants to journal a newly created buffer_head * (ie. getblk() returned a new buffer and we are going to populate it * manually rather than reading off disk), then we need to keep the * buffer_head locked until it has been completely filled with new * data. In this case, we should be able to make the assertion that * the bh is not already part of an existing transaction. * * The buffer should already be locked by the caller by this point. * There is no lock ranking violation: it was a newly created, * unlocked buffer beforehand. */ /** * jbd2_journal_get_create_access () - notify intent to use newly created bh * @handle: transaction to new buffer to * @bh: new buffer. * * Call this if you create a new bh. */ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; journal_t *journal; struct journal_head *jh = jbd2_journal_add_journal_head(bh); int err; jbd_debug(5, "journal_head %p\n", jh); err = -EROFS; if (is_handle_aborted(handle)) goto out; journal = transaction->t_journal; err = 0; JBUFFER_TRACE(jh, "entry"); /* * The buffer may already belong to this transaction due to pre-zeroing * in the filesystem's new_block code. It may also be on the previous, * committing transaction's lists, but it HAS to be in Forget state in * that case: the transaction must have deleted the buffer for it to be * reused here. */ spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, (jh->b_transaction == transaction || jh->b_transaction == NULL || (jh->b_transaction == journal->j_committing_transaction && jh->b_jlist == BJ_Forget))); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); if (jh->b_transaction == NULL) { /* * Previous jbd2_journal_forget() could have left the buffer * with jbddirty bit set because it was being committed. When * the commit finished, we've filed the buffer for * checkpointing and marked it dirty. Now we are reallocating * the buffer so the transaction freeing it must have * committed and so it's safe to clear the dirty bit. */ clear_buffer_dirty(jh2bh(jh)); /* first access by this transaction */ jh->b_modified = 0; JBUFFER_TRACE(jh, "file as BJ_Reserved"); spin_lock(&journal->j_list_lock); __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); spin_unlock(&journal->j_list_lock); } else if (jh->b_transaction == journal->j_committing_transaction) { /* first access by this transaction */ jh->b_modified = 0; JBUFFER_TRACE(jh, "set next transaction"); spin_lock(&journal->j_list_lock); jh->b_next_transaction = transaction; spin_unlock(&journal->j_list_lock); } spin_unlock(&jh->b_state_lock); /* * akpm: I added this. ext3_alloc_branch can pick up new indirect * blocks which contain freed but then revoked metadata. We need * to cancel the revoke in case we end up freeing it yet again * and the reallocating as data - this would cause a second revoke, * which hits an assertion error. */ JBUFFER_TRACE(jh, "cancelling revoke"); jbd2_journal_cancel_revoke(handle, jh); out: jbd2_journal_put_journal_head(jh); return err; } /** * jbd2_journal_get_undo_access() - Notify intent to modify metadata with * non-rewindable consequences * @handle: transaction * @bh: buffer to undo * * Sometimes there is a need to distinguish between metadata which has * been committed to disk and that which has not. The ext3fs code uses * this for freeing and allocating space, we have to make sure that we * do not reuse freed space until the deallocation has been committed, * since if we overwrote that space we would make the delete * un-rewindable in case of a crash. * * To deal with that, jbd2_journal_get_undo_access requests write access to a * buffer for parts of non-rewindable operations such as delete * operations on the bitmaps. The journaling code must keep a copy of * the buffer's contents prior to the undo_access call until such time * as we know that the buffer has definitely been committed to disk. * * We never need to know which transaction the committed data is part * of, buffers touched here are guaranteed to be dirtied later and so * will be committed to a new transaction in due course, at which point * we can discard the old committed data pointer. * * Returns error number or 0 on success. */ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) { int err; struct journal_head *jh; char *committed_data = NULL; if (is_handle_aborted(handle)) return -EROFS; if (jbd2_write_access_granted(handle, bh, true)) return 0; jh = jbd2_journal_add_journal_head(bh); JBUFFER_TRACE(jh, "entry"); /* * Do this first --- it can drop the journal lock, so we want to * make sure that obtaining the committed_data is done * atomically wrt. completion of any outstanding commits. */ err = do_get_write_access(handle, jh, 1); if (err) goto out; repeat: if (!jh->b_committed_data) committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS|__GFP_NOFAIL); spin_lock(&jh->b_state_lock); if (!jh->b_committed_data) { /* Copy out the current buffer contents into the * preserved, committed copy. */ JBUFFER_TRACE(jh, "generate b_committed data"); if (!committed_data) { spin_unlock(&jh->b_state_lock); goto repeat; } jh->b_committed_data = committed_data; committed_data = NULL; memcpy(jh->b_committed_data, bh->b_data, bh->b_size); } spin_unlock(&jh->b_state_lock); out: jbd2_journal_put_journal_head(jh); if (unlikely(committed_data)) jbd2_free(committed_data, bh->b_size); return err; } /** * jbd2_journal_set_triggers() - Add triggers for commit writeout * @bh: buffer to trigger on * @type: struct jbd2_buffer_trigger_type containing the trigger(s). * * Set any triggers on this journal_head. This is always safe, because * triggers for a committing buffer will be saved off, and triggers for * a running transaction will match the buffer in that transaction. * * Call with NULL to clear the triggers. */ void jbd2_journal_set_triggers(struct buffer_head *bh, struct jbd2_buffer_trigger_type *type) { struct journal_head *jh = jbd2_journal_grab_journal_head(bh); if (WARN_ON(!jh)) return; jh->b_triggers = type; jbd2_journal_put_journal_head(jh); } void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, struct jbd2_buffer_trigger_type *triggers) { struct buffer_head *bh = jh2bh(jh); if (!triggers || !triggers->t_frozen) return; triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); } void jbd2_buffer_abort_trigger(struct journal_head *jh, struct jbd2_buffer_trigger_type *triggers) { if (!triggers || !triggers->t_abort) return; triggers->t_abort(triggers, jh2bh(jh)); } /** * jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata * @handle: transaction to add buffer to. * @bh: buffer to mark * * mark dirty metadata which needs to be journaled as part of the current * transaction. * * The buffer must have previously had jbd2_journal_get_write_access() * called so that it has a valid journal_head attached to the buffer * head. * * The buffer is placed on the transaction's metadata list and is marked * as belonging to the transaction. * * Returns error number or 0 on success. * * Special care needs to be taken if the buffer already belongs to the * current committing transaction (in which case we should have frozen * data present for that commit). In that case, we don't relink the * buffer: that only gets done when the old transaction finally * completes its commit. */ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; journal_t *journal; struct journal_head *jh; int ret = 0; if (is_handle_aborted(handle)) return -EROFS; if (!buffer_jbd(bh)) return -EUCLEAN; /* * We don't grab jh reference here since the buffer must be part * of the running transaction. */ jh = bh2jh(bh); jbd_debug(5, "journal_head %p\n", jh); JBUFFER_TRACE(jh, "entry"); /* * This and the following assertions are unreliable since we may see jh * in inconsistent state unless we grab bh_state lock. But this is * crucial to catch bugs so let's do a reliable check until the * lockless handling is fully proven. */ if (data_race(jh->b_transaction != transaction && jh->b_next_transaction != transaction)) { spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, jh->b_transaction == transaction || jh->b_next_transaction == transaction); spin_unlock(&jh->b_state_lock); } if (jh->b_modified == 1) { /* If it's in our transaction it must be in BJ_Metadata list. */ if (data_race(jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata)) { spin_lock(&jh->b_state_lock); if (jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata) pr_err("JBD2: assertion failure: h_type=%u " "h_line_no=%u block_no=%llu jlist=%u\n", handle->h_type, handle->h_line_no, (unsigned long long) bh->b_blocknr, jh->b_jlist); J_ASSERT_JH(jh, jh->b_transaction != transaction || jh->b_jlist == BJ_Metadata); spin_unlock(&jh->b_state_lock); } goto out; } journal = transaction->t_journal; spin_lock(&jh->b_state_lock); if (jh->b_modified == 0) { /* * This buffer's got modified and becoming part * of the transaction. This needs to be done * once a transaction -bzzz */ if (WARN_ON_ONCE(jbd2_handle_buffer_credits(handle) <= 0)) { ret = -ENOSPC; goto out_unlock_bh; } jh->b_modified = 1; handle->h_total_credits--; } /* * fastpath, to avoid expensive locking. If this buffer is already * on the running transaction's metadata list there is nothing to do. * Nobody can take it off again because there is a handle open. * I _think_ we're OK here with SMP barriers - a mistaken decision will * result in this test being false, so we go in and take the locks. */ if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { JBUFFER_TRACE(jh, "fastpath"); if (unlikely(jh->b_transaction != journal->j_running_transaction)) { printk(KERN_ERR "JBD2: %s: " "jh->b_transaction (%llu, %p, %u) != " "journal->j_running_transaction (%p, %u)\n", journal->j_devname, (unsigned long long) bh->b_blocknr, jh->b_transaction, jh->b_transaction ? jh->b_transaction->t_tid : 0, journal->j_running_transaction, journal->j_running_transaction ? journal->j_running_transaction->t_tid : 0); ret = -EINVAL; } goto out_unlock_bh; } set_buffer_jbddirty(bh); /* * Metadata already on the current transaction list doesn't * need to be filed. Metadata on another transaction's list must * be committing, and will be refiled once the commit completes: * leave it alone for now. */ if (jh->b_transaction != transaction) { JBUFFER_TRACE(jh, "already on other transaction"); if (unlikely(((jh->b_transaction != journal->j_committing_transaction)) || (jh->b_next_transaction != transaction))) { printk(KERN_ERR "jbd2_journal_dirty_metadata: %s: " "bad jh for block %llu: " "transaction (%p, %u), " "jh->b_transaction (%p, %u), " "jh->b_next_transaction (%p, %u), jlist %u\n", journal->j_devname, (unsigned long long) bh->b_blocknr, transaction, transaction->t_tid, jh->b_transaction, jh->b_transaction ? jh->b_transaction->t_tid : 0, jh->b_next_transaction, jh->b_next_transaction ? jh->b_next_transaction->t_tid : 0, jh->b_jlist); WARN_ON(1); ret = -EINVAL; } /* And this case is illegal: we can't reuse another * transaction's data buffer, ever. */ goto out_unlock_bh; } /* That test should have eliminated the following case: */ J_ASSERT_JH(jh, jh->b_frozen_data == NULL); JBUFFER_TRACE(jh, "file as BJ_Metadata"); spin_lock(&journal->j_list_lock); __jbd2_journal_file_buffer(jh, transaction, BJ_Metadata); spin_unlock(&journal->j_list_lock); out_unlock_bh: spin_unlock(&jh->b_state_lock); out: JBUFFER_TRACE(jh, "exit"); return ret; } /** * jbd2_journal_forget() - bforget() for potentially-journaled buffers. * @handle: transaction handle * @bh: bh to 'forget' * * We can only do the bforget if there are no commits pending against the * buffer. If the buffer is dirty in the current running transaction we * can safely unlink it. * * bh may not be a journalled buffer at all - it may be a non-JBD * buffer which came off the hashtable. Check for this. * * Decrements bh->b_count by one. * * Allow this call even if the handle has aborted --- it may be part of * the caller's cleanup after an abort. */ int jbd2_journal_forget(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; journal_t *journal; struct journal_head *jh; int drop_reserve = 0; int err = 0; int was_modified = 0; if (is_handle_aborted(handle)) return -EROFS; journal = transaction->t_journal; BUFFER_TRACE(bh, "entry"); jh = jbd2_journal_grab_journal_head(bh); if (!jh) { __bforget(bh); return 0; } spin_lock(&jh->b_state_lock); /* Critical error: attempting to delete a bitmap buffer, maybe? * Don't do any jbd operations, and return an error. */ if (!J_EXPECT_JH(jh, !jh->b_committed_data, "inconsistent data on disk")) { err = -EIO; goto drop; } /* keep track of whether or not this transaction modified us */ was_modified = jh->b_modified; /* * The buffer's going from the transaction, we must drop * all references -bzzz */ jh->b_modified = 0; if (jh->b_transaction == transaction) { J_ASSERT_JH(jh, !jh->b_frozen_data); /* If we are forgetting a buffer which is already part * of this transaction, then we can just drop it from * the transaction immediately. */ clear_buffer_dirty(bh); clear_buffer_jbddirty(bh); JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); /* * we only want to drop a reference if this transaction * modified the buffer */ if (was_modified) drop_reserve = 1; /* * We are no longer going to journal this buffer. * However, the commit of this transaction is still * important to the buffer: the delete that we are now * processing might obsolete an old log entry, so by * committing, we can satisfy the buffer's checkpoint. * * So, if we have a checkpoint on the buffer, we should * now refile the buffer on our BJ_Forget list so that * we know to remove the checkpoint after we commit. */ spin_lock(&journal->j_list_lock); if (jh->b_cp_transaction) { __jbd2_journal_temp_unlink_buffer(jh); __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); } else { __jbd2_journal_unfile_buffer(jh); jbd2_journal_put_journal_head(jh); } spin_unlock(&journal->j_list_lock); } else if (jh->b_transaction) { J_ASSERT_JH(jh, (jh->b_transaction == journal->j_committing_transaction)); /* However, if the buffer is still owned by a prior * (committing) transaction, we can't drop it yet... */ JBUFFER_TRACE(jh, "belongs to older transaction"); /* ... but we CAN drop it from the new transaction through * marking the buffer as freed and set j_next_transaction to * the new transaction, so that not only the commit code * knows it should clear dirty bits when it is done with the * buffer, but also the buffer can be checkpointed only * after the new transaction commits. */ set_buffer_freed(bh); if (!jh->b_next_transaction) { spin_lock(&journal->j_list_lock); jh->b_next_transaction = transaction; spin_unlock(&journal->j_list_lock); } else { J_ASSERT(jh->b_next_transaction == transaction); /* * only drop a reference if this transaction modified * the buffer */ if (was_modified) drop_reserve = 1; } } else { /* * Finally, if the buffer is not belongs to any * transaction, we can just drop it now if it has no * checkpoint. */ spin_lock(&journal->j_list_lock); if (!jh->b_cp_transaction) { JBUFFER_TRACE(jh, "belongs to none transaction"); spin_unlock(&journal->j_list_lock); goto drop; } /* * Otherwise, if the buffer has been written to disk, * it is safe to remove the checkpoint and drop it. */ if (!buffer_dirty(bh)) { __jbd2_journal_remove_checkpoint(jh); spin_unlock(&journal->j_list_lock); goto drop; } /* * The buffer is still not written to disk, we should * attach this buffer to current transaction so that the * buffer can be checkpointed only after the current * transaction commits. */ clear_buffer_dirty(bh); __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); spin_unlock(&journal->j_list_lock); } drop: __brelse(bh); spin_unlock(&jh->b_state_lock); jbd2_journal_put_journal_head(jh); if (drop_reserve) { /* no need to reserve log space for this block -bzzz */ handle->h_total_credits++; } return err; } /** * jbd2_journal_stop() - complete a transaction * @handle: transaction to complete. * * All done for a particular handle. * * There is not much action needed here. We just return any remaining * buffer credits to the transaction and remove the handle. The only * complication is that we need to start a commit operation if the * filesystem is marked for synchronous update. * * jbd2_journal_stop itself will not usually return an error, but it may * do so in unusual circumstances. In particular, expect it to * return -EIO if a jbd2_journal_abort has been executed since the * transaction began. */ int jbd2_journal_stop(handle_t *handle) { transaction_t *transaction = handle->h_transaction; journal_t *journal; int err = 0, wait_for_commit = 0; tid_t tid; pid_t pid; if (--handle->h_ref > 0) { jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, handle->h_ref); if (is_handle_aborted(handle)) return -EIO; return 0; } if (!transaction) { /* * Handle is already detached from the transaction so there is * nothing to do other than free the handle. */ memalloc_nofs_restore(handle->saved_alloc_context); goto free_and_exit; } journal = transaction->t_journal; tid = transaction->t_tid; if (is_handle_aborted(handle)) err = -EIO; jbd_debug(4, "Handle %p going down\n", handle); trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev, tid, handle->h_type, handle->h_line_no, jiffies - handle->h_start_jiffies, handle->h_sync, handle->h_requested_credits, (handle->h_requested_credits - handle->h_total_credits)); /* * Implement synchronous transaction batching. If the handle * was synchronous, don't force a commit immediately. Let's * yield and let another thread piggyback onto this * transaction. Keep doing that while new threads continue to * arrive. It doesn't cost much - we're about to run a commit * and sleep on IO anyway. Speeds up many-threaded, many-dir * operations by 30x or more... * * We try and optimize the sleep time against what the * underlying disk can do, instead of having a static sleep * time. This is useful for the case where our storage is so * fast that it is more optimal to go ahead and force a flush * and wait for the transaction to be committed than it is to * wait for an arbitrary amount of time for new writers to * join the transaction. We achieve this by measuring how * long it takes to commit a transaction, and compare it with * how long this transaction has been running, and if run time * < commit time then we sleep for the delta and commit. This * greatly helps super fast disks that would see slowdowns as * more threads started doing fsyncs. * * But don't do this if this process was the most recent one * to perform a synchronous write. We do this to detect the * case where a single process is doing a stream of sync * writes. No point in waiting for joiners in that case. * * Setting max_batch_time to 0 disables this completely. */ pid = current->pid; if (handle->h_sync && journal->j_last_sync_writer != pid && journal->j_max_batch_time) { u64 commit_time, trans_time; journal->j_last_sync_writer = pid; read_lock(&journal->j_state_lock); commit_time = journal->j_average_commit_time; read_unlock(&journal->j_state_lock); trans_time = ktime_to_ns(ktime_sub(ktime_get(), transaction->t_start_time)); commit_time = max_t(u64, commit_time, 1000*journal->j_min_batch_time); commit_time = min_t(u64, commit_time, 1000*journal->j_max_batch_time); if (trans_time < commit_time) { ktime_t expires = ktime_add_ns(ktime_get(), commit_time); set_current_state(TASK_UNINTERRUPTIBLE); schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); } } if (handle->h_sync) transaction->t_synchronous_commit = 1; /* * If the handle is marked SYNC, we need to set another commit * going! We also want to force a commit if the transaction is too * old now. */ if (handle->h_sync || time_after_eq(jiffies, transaction->t_expires)) { /* Do this even for aborted journals: an abort still * completes the commit thread, it just doesn't write * anything to disk. */ jbd_debug(2, "transaction too old, requesting commit for " "handle %p\n", handle); /* This is non-blocking */ jbd2_log_start_commit(journal, tid); /* * Special case: JBD2_SYNC synchronous updates require us * to wait for the commit to complete. */ if (handle->h_sync && !(current->flags & PF_MEMALLOC)) wait_for_commit = 1; } /* * Once stop_this_handle() drops t_updates, the transaction could start * committing on us and eventually disappear. So we must not * dereference transaction pointer again after calling * stop_this_handle(). */ stop_this_handle(handle); if (wait_for_commit) err = jbd2_log_wait_commit(journal, tid); free_and_exit: if (handle->h_rsv_handle) jbd2_free_handle(handle->h_rsv_handle); jbd2_free_handle(handle); return err; } /* * * List management code snippets: various functions for manipulating the * transaction buffer lists. * */ /* * Append a buffer to a transaction list, given the transaction's list head * pointer. * * j_list_lock is held. * * jh->b_state_lock is held. */ static inline void __blist_add_buffer(struct journal_head **list, struct journal_head *jh) { if (!*list) { jh->b_tnext = jh->b_tprev = jh; *list = jh; } else { /* Insert at the tail of the list to preserve order */ struct journal_head *first = *list, *last = first->b_tprev; jh->b_tprev = last; jh->b_tnext = first; last->b_tnext = first->b_tprev = jh; } } /* * Remove a buffer from a transaction list, given the transaction's list * head pointer. * * Called with j_list_lock held, and the journal may not be locked. * * jh->b_state_lock is held. */ static inline void __blist_del_buffer(struct journal_head **list, struct journal_head *jh) { if (*list == jh) { *list = jh->b_tnext; if (*list == jh) *list = NULL; } jh->b_tprev->b_tnext = jh->b_tnext; jh->b_tnext->b_tprev = jh->b_tprev; } /* * Remove a buffer from the appropriate transaction list. * * Note that this function can *change* the value of * bh->b_transaction->t_buffers, t_forget, t_shadow_list, t_log_list or * t_reserved_list. If the caller is holding onto a copy of one of these * pointers, it could go bad. Generally the caller needs to re-read the * pointer from the transaction_t. * * Called under j_list_lock. */ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) { struct journal_head **list = NULL; transaction_t *transaction; struct buffer_head *bh = jh2bh(jh); lockdep_assert_held(&jh->b_state_lock); transaction = jh->b_transaction; if (transaction) assert_spin_locked(&transaction->t_journal->j_list_lock); J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); if (jh->b_jlist != BJ_None) J_ASSERT_JH(jh, transaction != NULL); switch (jh->b_jlist) { case BJ_None: return; case BJ_Metadata: transaction->t_nr_buffers--; J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); list = &transaction->t_buffers; break; case BJ_Forget: list = &transaction->t_forget; break; case BJ_Shadow: list = &transaction->t_shadow_list; break; case BJ_Reserved: list = &transaction->t_reserved_list; break; } __blist_del_buffer(list, jh); jh->b_jlist = BJ_None; if (transaction && is_journal_aborted(transaction->t_journal)) clear_buffer_jbddirty(bh); else if (test_clear_buffer_jbddirty(bh)) mark_buffer_dirty(bh); /* Expose it to the VM */ } /* * Remove buffer from all transactions. The caller is responsible for dropping * the jh reference that belonged to the transaction. * * Called with bh_state lock and j_list_lock */ static void __jbd2_journal_unfile_buffer(struct journal_head *jh) { J_ASSERT_JH(jh, jh->b_transaction != NULL); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); __jbd2_journal_temp_unlink_buffer(jh); jh->b_transaction = NULL; } void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) { struct buffer_head *bh = jh2bh(jh); /* Get reference so that buffer cannot be freed before we unlock it */ get_bh(bh); spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); __jbd2_journal_unfile_buffer(jh); spin_unlock(&journal->j_list_lock); spin_unlock(&jh->b_state_lock); jbd2_journal_put_journal_head(jh); __brelse(bh); } /* * Called from jbd2_journal_try_to_free_buffers(). * * Called under jh->b_state_lock */ static void __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) { struct journal_head *jh; jh = bh2jh(bh); if (buffer_locked(bh) || buffer_dirty(bh)) goto out; if (jh->b_next_transaction != NULL || jh->b_transaction != NULL) goto out; spin_lock(&journal->j_list_lock); if (jh->b_cp_transaction != NULL) { /* written-back checkpointed metadata buffer */ JBUFFER_TRACE(jh, "remove from checkpoint list"); __jbd2_journal_remove_checkpoint(jh); } spin_unlock(&journal->j_list_lock); out: return; } /** * jbd2_journal_try_to_free_buffers() - try to free page buffers. * @journal: journal for operation * @page: to try and free * * For all the buffers on this page, * if they are fully written out ordered data, move them onto BUF_CLEAN * so try_to_free_buffers() can reap them. * * This function returns non-zero if we wish try_to_free_buffers() * to be called. We do this if the page is releasable by try_to_free_buffers(). * We also do it if the page has locked or dirty buffers and the caller wants * us to perform sync or async writeout. * * This complicates JBD locking somewhat. We aren't protected by the * BKL here. We wish to remove the buffer from its committing or * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. * * This may *change* the value of transaction_t->t_datalist, so anyone * who looks at t_datalist needs to lock against this function. * * Even worse, someone may be doing a jbd2_journal_dirty_data on this * buffer. So we need to lock against that. jbd2_journal_dirty_data() * will come out of the lock with the buffer dirty, which makes it * ineligible for release here. * * Who else is affected by this? hmm... Really the only contender * is do_get_write_access() - it could be looking at the buffer while * journal_try_to_free_buffer() is changing its state. But that * cannot happen because we never reallocate freed data as metadata * while the data is part of a transaction. Yes? * * Return 0 on failure, 1 on success */ int jbd2_journal_try_to_free_buffers(journal_t *journal, struct page *page) { struct buffer_head *head; struct buffer_head *bh; bool has_write_io_error = false; int ret = 0; J_ASSERT(PageLocked(page)); head = page_buffers(page); bh = head; do { struct journal_head *jh; /* * We take our own ref against the journal_head here to avoid * having to add tons of locking around each instance of * jbd2_journal_put_journal_head(). */ jh = jbd2_journal_grab_journal_head(bh); if (!jh) continue; spin_lock(&jh->b_state_lock); __journal_try_to_free_buffer(journal, bh); spin_unlock(&jh->b_state_lock); jbd2_journal_put_journal_head(jh); if (buffer_jbd(bh)) goto busy; /* * If we free a metadata buffer which has been failed to * write out, the jbd2 checkpoint procedure will not detect * this failure and may lead to filesystem inconsistency * after cleanup journal tail. */ if (buffer_write_io_error(bh)) { pr_err("JBD2: Error while async write back metadata bh %llu.", (unsigned long long)bh->b_blocknr); has_write_io_error = true; } } while ((bh = bh->b_this_page) != head); ret = try_to_free_buffers(page); busy: if (has_write_io_error) jbd2_journal_abort(journal, -EIO); return ret; } /* * This buffer is no longer needed. If it is on an older transaction's * checkpoint list we need to record it on this transaction's forget list * to pin this buffer (and hence its checkpointing transaction) down until * this transaction commits. If the buffer isn't on a checkpoint list, we * release it. * Returns non-zero if JBD no longer has an interest in the buffer. * * Called under j_list_lock. * * Called under jh->b_state_lock. */ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) { int may_free = 1; struct buffer_head *bh = jh2bh(jh); if (jh->b_cp_transaction) { JBUFFER_TRACE(jh, "on running+cp transaction"); __jbd2_journal_temp_unlink_buffer(jh); /* * We don't want to write the buffer anymore, clear the * bit so that we don't confuse checks in * __journal_file_buffer */ clear_buffer_dirty(bh); __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); may_free = 0; } else { JBUFFER_TRACE(jh, "on running transaction"); __jbd2_journal_unfile_buffer(jh); jbd2_journal_put_journal_head(jh); } return may_free; } /* * jbd2_journal_invalidatepage * * This code is tricky. It has a number of cases to deal with. * * There are two invariants which this code relies on: * * i_size must be updated on disk before we start calling invalidatepage on the * data. * * This is done in ext3 by defining an ext3_setattr method which * updates i_size before truncate gets going. By maintaining this * invariant, we can be sure that it is safe to throw away any buffers * attached to the current transaction: once the transaction commits, * we know that the data will not be needed. * * Note however that we can *not* throw away data belonging to the * previous, committing transaction! * * Any disk blocks which *are* part of the previous, committing * transaction (and which therefore cannot be discarded immediately) are * not going to be reused in the new running transaction * * The bitmap committed_data images guarantee this: any block which is * allocated in one transaction and removed in the next will be marked * as in-use in the committed_data bitmap, so cannot be reused until * the next transaction to delete the block commits. This means that * leaving committing buffers dirty is quite safe: the disk blocks * cannot be reallocated to a different file and so buffer aliasing is * not possible. * * * The above applies mainly to ordered data mode. In writeback mode we * don't make guarantees about the order in which data hits disk --- in * particular we don't guarantee that new dirty data is flushed before * transaction commit --- so it is always safe just to discard data * immediately in that mode. --sct */ /* * The journal_unmap_buffer helper function returns zero if the buffer * concerned remains pinned as an anonymous buffer belonging to an older * transaction. * * We're outside-transaction here. Either or both of j_running_transaction * and j_committing_transaction may be NULL. */ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, int partial_page) { transaction_t *transaction; struct journal_head *jh; int may_free = 1; BUFFER_TRACE(bh, "entry"); /* * It is safe to proceed here without the j_list_lock because the * buffers cannot be stolen by try_to_free_buffers as long as we are * holding the page lock. --sct */ jh = jbd2_journal_grab_journal_head(bh); if (!jh) goto zap_buffer_unlocked; /* OK, we have data buffer in journaled mode */ write_lock(&journal->j_state_lock); spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); /* * We cannot remove the buffer from checkpoint lists until the * transaction adding inode to orphan list (let's call it T) * is committed. Otherwise if the transaction changing the * buffer would be cleaned from the journal before T is * committed, a crash will cause that the correct contents of * the buffer will be lost. On the other hand we have to * clear the buffer dirty bit at latest at the moment when the * transaction marking the buffer as freed in the filesystem * structures is committed because from that moment on the * block can be reallocated and used by a different page. * Since the block hasn't been freed yet but the inode has * already been added to orphan list, it is safe for us to add * the buffer to BJ_Forget list of the newest transaction. * * Also we have to clear buffer_mapped flag of a truncated buffer * because the buffer_head may be attached to the page straddling * i_size (can happen only when blocksize < pagesize) and thus the * buffer_head can be reused when the file is extended again. So we end * up keeping around invalidated buffers attached to transactions' * BJ_Forget list just to stop checkpointing code from cleaning up * the transaction this buffer was modified in. */ transaction = jh->b_transaction; if (transaction == NULL) { /* First case: not on any transaction. If it * has no checkpoint link, then we can zap it: * it's a writeback-mode buffer so we don't care * if it hits disk safely. */ if (!jh->b_cp_transaction) { JBUFFER_TRACE(jh, "not on any transaction: zap"); goto zap_buffer; } if (!buffer_dirty(bh)) { /* bdflush has written it. We can drop it now */ __jbd2_journal_remove_checkpoint(jh); goto zap_buffer; } /* OK, it must be in the journal but still not * written fully to disk: it's metadata or * journaled data... */ if (journal->j_running_transaction) { /* ... and once the current transaction has * committed, the buffer won't be needed any * longer. */ JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); may_free = __dispose_buffer(jh, journal->j_running_transaction); goto zap_buffer; } else { /* There is no currently-running transaction. So the * orphan record which we wrote for this file must have * passed into commit. We must attach this buffer to * the committing transaction, if it exists. */ if (journal->j_committing_transaction) { JBUFFER_TRACE(jh, "give to committing trans"); may_free = __dispose_buffer(jh, journal->j_committing_transaction); goto zap_buffer; } else { /* The orphan record's transaction has * committed. We can cleanse this buffer */ clear_buffer_jbddirty(bh); __jbd2_journal_remove_checkpoint(jh); goto zap_buffer; } } } else if (transaction == journal->j_committing_transaction) { JBUFFER_TRACE(jh, "on committing transaction"); /* * The buffer is committing, we simply cannot touch * it. If the page is straddling i_size we have to wait * for commit and try again. */ if (partial_page) { spin_unlock(&journal->j_list_lock); spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); jbd2_journal_put_journal_head(jh); return -EBUSY; } /* * OK, buffer won't be reachable after truncate. We just clear * b_modified to not confuse transaction credit accounting, and * set j_next_transaction to the running transaction (if there * is one) and mark buffer as freed so that commit code knows * it should clear dirty bits when it is done with the buffer. */ set_buffer_freed(bh); if (journal->j_running_transaction && buffer_jbddirty(bh)) jh->b_next_transaction = journal->j_running_transaction; jh->b_modified = 0; spin_unlock(&journal->j_list_lock); spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); jbd2_journal_put_journal_head(jh); return 0; } else { /* Good, the buffer belongs to the running transaction. * We are writing our own transaction's data, not any * previous one's, so it is safe to throw it away * (remember that we expect the filesystem to have set * i_size already for this truncate so recovery will not * expose the disk blocks we are discarding here.) */ J_ASSERT_JH(jh, transaction == journal->j_running_transaction); JBUFFER_TRACE(jh, "on running transaction"); may_free = __dispose_buffer(jh, transaction); } zap_buffer: /* * This is tricky. Although the buffer is truncated, it may be reused * if blocksize < pagesize and it is attached to the page straddling * EOF. Since the buffer might have been added to BJ_Forget list of the * running transaction, journal_get_write_access() won't clear * b_modified and credit accounting gets confused. So clear b_modified * here. */ jh->b_modified = 0; spin_unlock(&journal->j_list_lock); spin_unlock(&jh->b_state_lock); write_unlock(&journal->j_state_lock); jbd2_journal_put_journal_head(jh); zap_buffer_unlocked: clear_buffer_dirty(bh); J_ASSERT_BH(bh, !buffer_jbddirty(bh)); clear_buffer_mapped(bh); clear_buffer_req(bh); clear_buffer_new(bh); clear_buffer_delay(bh); clear_buffer_unwritten(bh); bh->b_bdev = NULL; return may_free; } /** * jbd2_journal_invalidatepage() * @journal: journal to use for flush... * @page: page to flush * @offset: start of the range to invalidate * @length: length of the range to invalidate * * Reap page buffers containing data after in the specified range in page. * Can return -EBUSY if buffers are part of the committing transaction and * the page is straddling i_size. Caller then has to wait for current commit * and try again. */ int jbd2_journal_invalidatepage(journal_t *journal, struct page *page, unsigned int offset, unsigned int length) { struct buffer_head *head, *bh, *next; unsigned int stop = offset + length; unsigned int curr_off = 0; int partial_page = (offset || length < PAGE_SIZE); int may_free = 1; int ret = 0; if (!PageLocked(page)) BUG(); if (!page_has_buffers(page)) return 0; BUG_ON(stop > PAGE_SIZE || stop < length); /* We will potentially be playing with lists other than just the * data lists (especially for journaled data mode), so be * cautious in our locking. */ head = bh = page_buffers(page); do { unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; if (next_off > stop) return 0; if (offset <= curr_off) { /* This block is wholly outside the truncation point */ lock_buffer(bh); ret = journal_unmap_buffer(journal, bh, partial_page); unlock_buffer(bh); if (ret < 0) return ret; may_free &= ret; } curr_off = next_off; bh = next; } while (bh != head); if (!partial_page) { if (may_free && try_to_free_buffers(page)) J_ASSERT(!page_has_buffers(page)); } return 0; } /* * File a buffer on the given transaction list. */ void __jbd2_journal_file_buffer(struct journal_head *jh, transaction_t *transaction, int jlist) { struct journal_head **list = NULL; int was_dirty = 0; struct buffer_head *bh = jh2bh(jh); lockdep_assert_held(&jh->b_state_lock); assert_spin_locked(&transaction->t_journal->j_list_lock); J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); J_ASSERT_JH(jh, jh->b_transaction == transaction || jh->b_transaction == NULL); if (jh->b_transaction && jh->b_jlist == jlist) return; if (jlist == BJ_Metadata || jlist == BJ_Reserved || jlist == BJ_Shadow || jlist == BJ_Forget) { /* * For metadata buffers, we track dirty bit in buffer_jbddirty * instead of buffer_dirty. We should not see a dirty bit set * here because we clear it in do_get_write_access but e.g. * tune2fs can modify the sb and set the dirty bit at any time * so we try to gracefully handle that. */ if (buffer_dirty(bh)) warn_dirty_buffer(bh); if (test_clear_buffer_dirty(bh) || test_clear_buffer_jbddirty(bh)) was_dirty = 1; } if (jh->b_transaction) __jbd2_journal_temp_unlink_buffer(jh); else jbd2_journal_grab_journal_head(bh); jh->b_transaction = transaction; switch (jlist) { case BJ_None: J_ASSERT_JH(jh, !jh->b_committed_data); J_ASSERT_JH(jh, !jh->b_frozen_data); return; case BJ_Metadata: transaction->t_nr_buffers++; list = &transaction->t_buffers; break; case BJ_Forget: list = &transaction->t_forget; break; case BJ_Shadow: list = &transaction->t_shadow_list; break; case BJ_Reserved: list = &transaction->t_reserved_list; break; } __blist_add_buffer(list, jh); jh->b_jlist = jlist; if (was_dirty) set_buffer_jbddirty(bh); } void jbd2_journal_file_buffer(struct journal_head *jh, transaction_t *transaction, int jlist) { spin_lock(&jh->b_state_lock); spin_lock(&transaction->t_journal->j_list_lock); __jbd2_journal_file_buffer(jh, transaction, jlist); spin_unlock(&transaction->t_journal->j_list_lock); spin_unlock(&jh->b_state_lock); } /* * Remove a buffer from its current buffer list in preparation for * dropping it from its current transaction entirely. If the buffer has * already started to be used by a subsequent transaction, refile the * buffer on that transaction's metadata list. * * Called under j_list_lock * Called under jh->b_state_lock * * When this function returns true, there's no next transaction to refile to * and the caller has to drop jh reference through * jbd2_journal_put_journal_head(). */ bool __jbd2_journal_refile_buffer(struct journal_head *jh) { int was_dirty, jlist; struct buffer_head *bh = jh2bh(jh); lockdep_assert_held(&jh->b_state_lock); if (jh->b_transaction) assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); /* If the buffer is now unused, just drop it. */ if (jh->b_next_transaction == NULL) { __jbd2_journal_unfile_buffer(jh); return true; } /* * It has been modified by a later transaction: add it to the new * transaction's metadata list. */ was_dirty = test_clear_buffer_jbddirty(bh); __jbd2_journal_temp_unlink_buffer(jh); /* * b_transaction must be set, otherwise the new b_transaction won't * be holding jh reference */ J_ASSERT_JH(jh, jh->b_transaction != NULL); /* * We set b_transaction here because b_next_transaction will inherit * our jh reference and thus __jbd2_journal_file_buffer() must not * take a new one. */ WRITE_ONCE(jh->b_transaction, jh->b_next_transaction); WRITE_ONCE(jh->b_next_transaction, NULL); if (buffer_freed(bh)) jlist = BJ_Forget; else if (jh->b_modified) jlist = BJ_Metadata; else jlist = BJ_Reserved; __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); if (was_dirty) set_buffer_jbddirty(bh); return false; } /* * __jbd2_journal_refile_buffer() with necessary locking added. We take our * bh reference so that we can safely unlock bh. * * The jh and bh may be freed by this call. */ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) { bool drop; spin_lock(&jh->b_state_lock); spin_lock(&journal->j_list_lock); drop = __jbd2_journal_refile_buffer(jh); spin_unlock(&jh->b_state_lock); spin_unlock(&journal->j_list_lock); if (drop) jbd2_journal_put_journal_head(jh); } /* * File inode in the inode list of the handle's transaction */ static int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode, unsigned long flags, loff_t start_byte, loff_t end_byte) { transaction_t *transaction = handle->h_transaction; journal_t *journal; if (is_handle_aborted(handle)) return -EROFS; journal = transaction->t_journal; jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, transaction->t_tid); spin_lock(&journal->j_list_lock); jinode->i_flags |= flags; if (jinode->i_dirty_end) { jinode->i_dirty_start = min(jinode->i_dirty_start, start_byte); jinode->i_dirty_end = max(jinode->i_dirty_end, end_byte); } else { jinode->i_dirty_start = start_byte; jinode->i_dirty_end = end_byte; } /* Is inode already attached where we need it? */ if (jinode->i_transaction == transaction || jinode->i_next_transaction == transaction) goto done; /* * We only ever set this variable to 1 so the test is safe. Since * t_need_data_flush is likely to be set, we do the test to save some * cacheline bouncing */ if (!transaction->t_need_data_flush) transaction->t_need_data_flush = 1; /* On some different transaction's list - should be * the committing one */ if (jinode->i_transaction) { J_ASSERT(jinode->i_next_transaction == NULL); J_ASSERT(jinode->i_transaction == journal->j_committing_transaction); jinode->i_next_transaction = transaction; goto done; } /* Not on any transaction list... */ J_ASSERT(!jinode->i_next_transaction); jinode->i_transaction = transaction; list_add(&jinode->i_list, &transaction->t_inode_list); done: spin_unlock(&journal->j_list_lock); return 0; } int jbd2_journal_inode_ranged_write(handle_t *handle, struct jbd2_inode *jinode, loff_t start_byte, loff_t length) { return jbd2_journal_file_inode(handle, jinode, JI_WRITE_DATA | JI_WAIT_DATA, start_byte, start_byte + length - 1); } int jbd2_journal_inode_ranged_wait(handle_t *handle, struct jbd2_inode *jinode, loff_t start_byte, loff_t length) { return jbd2_journal_file_inode(handle, jinode, JI_WAIT_DATA, start_byte, start_byte + length - 1); } /* * File truncate and transaction commit interact with each other in a * non-trivial way. If a transaction writing data block A is * committing, we cannot discard the data by truncate until we have * written them. Otherwise if we crashed after the transaction with * write has committed but before the transaction with truncate has * committed, we could see stale data in block A. This function is a * helper to solve this problem. It starts writeout of the truncated * part in case it is in the committing transaction. * * Filesystem code must call this function when inode is journaled in * ordered mode before truncation happens and after the inode has been * placed on orphan list with the new inode size. The second condition * avoids the race that someone writes new data and we start * committing the transaction after this function has been called but * before a transaction for truncate is started (and furthermore it * allows us to optimize the case where the addition to orphan list * happens in the same transaction as write --- we don't have to write * any data in such case). */ int jbd2_journal_begin_ordered_truncate(journal_t *journal, struct jbd2_inode *jinode, loff_t new_size) { transaction_t *inode_trans, *commit_trans; int ret = 0; /* This is a quick check to avoid locking if not necessary */ if (!jinode->i_transaction) goto out; /* Locks are here just to force reading of recent values, it is * enough that the transaction was not committing before we started * a transaction adding the inode to orphan list */ read_lock(&journal->j_state_lock); commit_trans = journal->j_committing_transaction; read_unlock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); inode_trans = jinode->i_transaction; spin_unlock(&journal->j_list_lock); if (inode_trans == commit_trans) { ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, new_size, LLONG_MAX); if (ret) jbd2_journal_abort(journal, ret); } out: return ret; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 /* SPDX-License-Identifier: GPL-2.0 OR MIT */ #ifndef __LINUX_OVERFLOW_H #define __LINUX_OVERFLOW_H #include <linux/compiler.h> #include <linux/limits.h> /* * In the fallback code below, we need to compute the minimum and * maximum values representable in a given type. These macros may also * be useful elsewhere, so we provide them outside the * COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block. * * It would seem more obvious to do something like * * #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0) * #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0) * * Unfortunately, the middle expressions, strictly speaking, have * undefined behaviour, and at least some versions of gcc warn about * the type_max expression (but not if -fsanitize=undefined is in * effect; in that case, the warning is deferred to runtime...). * * The slightly excessive casting in type_min is to make sure the * macros also produce sensible values for the exotic type _Bool. [The * overflow checkers only almost work for _Bool, but that's * a-feature-not-a-bug, since people shouldn't be doing arithmetic on * _Bools. Besides, the gcc builtins don't allow _Bool* as third * argument.] * * Idea stolen from * https://mail-index.netbsd.org/tech-misc/2007/02/05/0000.html - * credit to Christian Biere. */ #define is_signed_type(type) (((type)(-1)) < (type)1) #define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type))) #define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T))) #define type_min(T) ((T)((T)-type_max(T)-(T)1)) /* * Avoids triggering -Wtype-limits compilation warning, * while using unsigned data types to check a < 0. */ #define is_non_negative(a) ((a) > 0 || (a) == 0) #define is_negative(a) (!(is_non_negative(a))) /* * Allows for effectively applying __must_check to a macro so we can have * both the type-agnostic benefits of the macros while also being able to * enforce that the return value is, in fact, checked. */ static inline bool __must_check __must_check_overflow(bool overflow) { return unlikely(overflow); } #ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW /* * For simplicity and code hygiene, the fallback code below insists on * a, b and *d having the same type (similar to the min() and max() * macros), whereas gcc's type-generic overflow checkers accept * different types. Hence we don't just make check_add_overflow an * alias for __builtin_add_overflow, but add type checks similar to * below. */ #define check_add_overflow(a, b, d) __must_check_overflow(({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ __builtin_add_overflow(__a, __b, __d); \ })) #define check_sub_overflow(a, b, d) __must_check_overflow(({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ __builtin_sub_overflow(__a, __b, __d); \ })) #define check_mul_overflow(a, b, d) __must_check_overflow(({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ __builtin_mul_overflow(__a, __b, __d); \ })) #else /* Checking for unsigned overflow is relatively easy without causing UB. */ #define __unsigned_add_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = __a + __b; \ *__d < __a; \ }) #define __unsigned_sub_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = __a - __b; \ __a < __b; \ }) /* * If one of a or b is a compile-time constant, this avoids a division. */ #define __unsigned_mul_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = __a * __b; \ __builtin_constant_p(__b) ? \ __b > 0 && __a > type_max(typeof(__a)) / __b : \ __a > 0 && __b > type_max(typeof(__b)) / __a; \ }) /* * For signed types, detecting overflow is much harder, especially if * we want to avoid UB. But the interface of these macros is such that * we must provide a result in *d, and in fact we must produce the * result promised by gcc's builtins, which is simply the possibly * wrapped-around value. Fortunately, we can just formally do the * operations in the widest relevant unsigned type (u64) and then * truncate the result - gcc is smart enough to generate the same code * with and without the (u64) casts. */ /* * Adding two signed integers can overflow only if they have the same * sign, and overflow has happened iff the result has the opposite * sign. */ #define __signed_add_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = (u64)__a + (u64)__b; \ (((~(__a ^ __b)) & (*__d ^ __a)) \ & type_min(typeof(__a))) != 0; \ }) /* * Subtraction is similar, except that overflow can now happen only * when the signs are opposite. In this case, overflow has happened if * the result has the opposite sign of a. */ #define __signed_sub_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = (u64)__a - (u64)__b; \ ((((__a ^ __b)) & (*__d ^ __a)) \ & type_min(typeof(__a))) != 0; \ }) /* * Signed multiplication is rather hard. gcc always follows C99, so * division is truncated towards 0. This means that we can write the * overflow check like this: * * (a > 0 && (b > MAX/a || b < MIN/a)) || * (a < -1 && (b > MIN/a || b < MAX/a) || * (a == -1 && b == MIN) * * The redundant casts of -1 are to silence an annoying -Wtype-limits * (included in -Wextra) warning: When the type is u8 or u16, the * __b_c_e in check_mul_overflow obviously selects * __unsigned_mul_overflow, but unfortunately gcc still parses this * code and warns about the limited range of __b. */ #define __signed_mul_overflow(a, b, d) ({ \ typeof(a) __a = (a); \ typeof(b) __b = (b); \ typeof(d) __d = (d); \ typeof(a) __tmax = type_max(typeof(a)); \ typeof(a) __tmin = type_min(typeof(a)); \ (void) (&__a == &__b); \ (void) (&__a == __d); \ *__d = (u64)__a * (u64)__b; \ (__b > 0 && (__a > __tmax/__b || __a < __tmin/__b)) || \ (__b < (typeof(__b))-1 && (__a > __tmin/__b || __a < __tmax/__b)) || \ (__b == (typeof(__b))-1 && __a == __tmin); \ }) #define check_add_overflow(a, b, d) __must_check_overflow( \ __builtin_choose_expr(is_signed_type(typeof(a)), \ __signed_add_overflow(a, b, d), \ __unsigned_add_overflow(a, b, d))) #define check_sub_overflow(a, b, d) __must_check_overflow( \ __builtin_choose_expr(is_signed_type(typeof(a)), \ __signed_sub_overflow(a, b, d), \ __unsigned_sub_overflow(a, b, d))) #define check_mul_overflow(a, b, d) __must_check_overflow( \ __builtin_choose_expr(is_signed_type(typeof(a)), \ __signed_mul_overflow(a, b, d), \ __unsigned_mul_overflow(a, b, d))) #endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */ /** check_shl_overflow() - Calculate a left-shifted value and check overflow * * @a: Value to be shifted * @s: How many bits left to shift * @d: Pointer to where to store the result * * Computes *@d = (@a << @s) * * Returns true if '*d' cannot hold the result or when 'a << s' doesn't * make sense. Example conditions: * - 'a << s' causes bits to be lost when stored in *d. * - 's' is garbage (e.g. negative) or so large that the result of * 'a << s' is guaranteed to be 0. * - 'a' is negative. * - 'a << s' sets the sign bit, if any, in '*d'. * * '*d' will hold the results of the attempted shift, but is not * considered "safe for use" if false is returned. */ #define check_shl_overflow(a, s, d) __must_check_overflow(({ \ typeof(a) _a = a; \ typeof(s) _s = s; \ typeof(d) _d = d; \ u64 _a_full = _a; \ unsigned int _to_shift = \ is_non_negative(_s) && _s < 8 * sizeof(*d) ? _s : 0; \ *_d = (_a_full << _to_shift); \ (_to_shift != _s || is_negative(*_d) || is_negative(_a) || \ (*_d >> _to_shift) != _a); \ })) /** * array_size() - Calculate size of 2-dimensional array. * * @a: dimension one * @b: dimension two * * Calculates size of 2-dimensional array: @a * @b. * * Returns: number of bytes needed to represent the array or SIZE_MAX on * overflow. */ static inline __must_check size_t array_size(size_t a, size_t b) { size_t bytes; if (check_mul_overflow(a, b, &bytes)) return SIZE_MAX; return bytes; } /** * array3_size() - Calculate size of 3-dimensional array. * * @a: dimension one * @b: dimension two * @c: dimension three * * Calculates size of 3-dimensional array: @a * @b * @c. * * Returns: number of bytes needed to represent the array or SIZE_MAX on * overflow. */ static inline __must_check size_t array3_size(size_t a, size_t b, size_t c) { size_t bytes; if (check_mul_overflow(a, b, &bytes)) return SIZE_MAX; if (check_mul_overflow(bytes, c, &bytes)) return SIZE_MAX; return bytes; } /* * Compute a*b+c, returning SIZE_MAX on overflow. Internal helper for * struct_size() below. */ static inline __must_check size_t __ab_c_size(size_t a, size_t b, size_t c) { size_t bytes; if (check_mul_overflow(a, b, &bytes)) return SIZE_MAX; if (check_add_overflow(bytes, c, &bytes)) return SIZE_MAX; return bytes; } /** * struct_size() - Calculate size of structure with trailing array. * @p: Pointer to the structure. * @member: Name of the array member. * @count: Number of elements in the array. * * Calculates size of memory needed for structure @p followed by an * array of @count number of @member elements. * * Return: number of bytes needed or SIZE_MAX on overflow. */ #define struct_size(p, member, count) \ __ab_c_size(count, \ sizeof(*(p)->member) + __must_be_array((p)->member),\ sizeof(*(p))) /** * flex_array_size() - Calculate size of a flexible array member * within an enclosing structure. * * @p: Pointer to the structure. * @member: Name of the flexible array member. * @count: Number of elements in the array. * * Calculates size of a flexible array of @count number of @member * elements, at the end of structure @p. * * Return: number of bytes needed or SIZE_MAX on overflow. */ #define flex_array_size(p, member, count) \ array_size(count, \ sizeof(*(p)->member) + __must_be_array((p)->member)) #endif /* __LINUX_OVERFLOW_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 /* SPDX-License-Identifier: GPL-2.0-or-later */ /* * include/linux/eventpoll.h ( Efficient event polling implementation ) * Copyright (C) 2001,...,2006 Davide Libenzi * * Davide Libenzi <davidel@xmailserver.org> */ #ifndef _LINUX_EVENTPOLL_H #define _LINUX_EVENTPOLL_H #include <uapi/linux/eventpoll.h> #include <uapi/linux/kcmp.h> /* Forward declarations to avoid compiler errors */ struct file; #ifdef CONFIG_EPOLL #ifdef CONFIG_KCMP struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, unsigned long toff); #endif /* Used to initialize the epoll bits inside the "struct file" */ static inline void eventpoll_init_file(struct file *file) { INIT_LIST_HEAD(&file->f_ep_links); INIT_LIST_HEAD(&file->f_tfile_llink); } /* Used to release the epoll bits inside the "struct file" */ void eventpoll_release_file(struct file *file); /* * This is called from inside fs/file_table.c:__fput() to unlink files * from the eventpoll interface. We need to have this facility to cleanup * correctly files that are closed without being removed from the eventpoll * interface. */ static inline void eventpoll_release(struct file *file) { /* * Fast check to avoid the get/release of the semaphore. Since * we're doing this outside the semaphore lock, it might return * false negatives, but we don't care. It'll help in 99.99% of cases * to avoid the semaphore lock. False positives simply cannot happen * because the file in on the way to be removed and nobody ( but * eventpoll ) has still a reference to this file. */ if (likely(list_empty(&file->f_ep_links))) return; /* * The file is being closed while it is still linked to an epoll * descriptor. We need to handle this by correctly unlinking it * from its containers. */ eventpoll_release_file(file); } int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds, bool nonblock); /* Tells if the epoll_ctl(2) operation needs an event copy from userspace */ static inline int ep_op_has_event(int op) { return op != EPOLL_CTL_DEL; } #else static inline void eventpoll_init_file(struct file *file) {} static inline void eventpoll_release(struct file *file) {} #endif #endif /* #ifndef _LINUX_EVENTPOLL_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _XFRM_HASH_H #define _XFRM_HASH_H #include <linux/xfrm.h> #include <linux/socket.h> #include <linux/jhash.h> static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr) { return ntohl(addr->a4); } static inline unsigned int __xfrm6_addr_hash(const xfrm_address_t *addr) { return jhash2((__force u32 *)addr->a6, 4, 0); } static inline unsigned int __xfrm4_daddr_saddr_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr) { u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4; return ntohl((__force __be32)sum); } static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr) { return __xfrm6_addr_hash(daddr) ^ __xfrm6_addr_hash(saddr); } static inline u32 __bits2mask32(__u8 bits) { u32 mask32 = 0xffffffff; if (bits == 0) mask32 = 0; else if (bits < 32) mask32 <<= (32 - bits); return mask32; } static inline unsigned int __xfrm4_dpref_spref_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr, __u8 dbits, __u8 sbits) { return jhash_2words(ntohl(daddr->a4) & __bits2mask32(dbits), ntohl(saddr->a4) & __bits2mask32(sbits), 0); } static inline unsigned int __xfrm6_pref_hash(const xfrm_address_t *addr, __u8 prefixlen) { unsigned int pdw; unsigned int pbi; u32 initval = 0; pdw = prefixlen >> 5; /* num of whole u32 in prefix */ pbi = prefixlen & 0x1f; /* num of bits in incomplete u32 in prefix */ if (pbi) { __be32 mask; mask = htonl((0xffffffff) << (32 - pbi)); initval = (__force u32)(addr->a6[pdw] & mask); } return jhash2((__force u32 *)addr->a6, pdw, initval); } static inline unsigned int __xfrm6_dpref_spref_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr, __u8 dbits, __u8 sbits) { return __xfrm6_pref_hash(daddr, dbits) ^ __xfrm6_pref_hash(saddr, sbits); } static inline unsigned int __xfrm_dst_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr, u32 reqid, unsigned short family, unsigned int hmask) { unsigned int h = family ^ reqid; switch (family) { case AF_INET: h ^= __xfrm4_daddr_saddr_hash(daddr, saddr); break; case AF_INET6: h ^= __xfrm6_daddr_saddr_hash(daddr, saddr); break; } return (h ^ (h >> 16)) & hmask; } static inline unsigned int __xfrm_src_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr, unsigned short family, unsigned int hmask) { unsigned int h = family; switch (family) { case AF_INET: h ^= __xfrm4_daddr_saddr_hash(daddr, saddr); break; case AF_INET6: h ^= __xfrm6_daddr_saddr_hash(daddr, saddr); break; } return (h ^ (h >> 16)) & hmask; } static inline unsigned int __xfrm_spi_hash(const xfrm_address_t *daddr, __be32 spi, u8 proto, unsigned short family, unsigned int hmask) { unsigned int h = (__force u32)spi ^ proto; switch (family) { case AF_INET: h ^= __xfrm4_addr_hash(daddr); break; case AF_INET6: h ^= __xfrm6_addr_hash(daddr); break; } return (h ^ (h >> 10) ^ (h >> 20)) & hmask; } static inline unsigned int __idx_hash(u32 index, unsigned int hmask) { return (index ^ (index >> 8)) & hmask; } static inline unsigned int __sel_hash(const struct xfrm_selector *sel, unsigned short family, unsigned int hmask, u8 dbits, u8 sbits) { const xfrm_address_t *daddr = &sel->daddr; const xfrm_address_t *saddr = &sel->saddr; unsigned int h = 0; switch (family) { case AF_INET: if (sel->prefixlen_d < dbits || sel->prefixlen_s < sbits) return hmask + 1; h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits); break; case AF_INET6: if (sel->prefixlen_d < dbits || sel->prefixlen_s < sbits) return hmask + 1; h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits); break; } h ^= (h >> 16); return h & hmask; } static inline unsigned int __addr_hash(const xfrm_address_t *daddr, const xfrm_address_t *saddr, unsigned short family, unsigned int hmask, u8 dbits, u8 sbits) { unsigned int h = 0; switch (family) { case AF_INET: h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits); break; case AF_INET6: h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits); break; } h ^= (h >> 16); return h & hmask; } struct hlist_head *xfrm_hash_alloc(unsigned int sz); void xfrm_hash_free(struct hlist_head *n, unsigned int sz); #endif /* _XFRM_HASH_H */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_KERNEL_H #define _LINUX_KERNEL_H #include <stdarg.h> #include <linux/limits.h> #include <linux/linkage.h> #include <linux/stddef.h> #include <linux/types.h> #include <linux/compiler.h> #include <linux/bitops.h> #include <linux/log2.h> #include <linux/minmax.h> #include <linux/typecheck.h> #include <linux/printk.h> #include <linux/build_bug.h> #include <asm/byteorder.h> #include <asm/div64.h> #include <uapi/linux/kernel.h> #define STACK_MAGIC 0xdeadbeef /** * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value * @x: value to repeat * * NOTE: @x is not checked for > 0xff; larger values produce odd results. */ #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) /* @a is a power of 2 value */ #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) #define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) #define PTR_ALIGN_DOWN(p, a) ((typeof(p))ALIGN_DOWN((unsigned long)(p), (a))) #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) /* generic data direction definitions */ #define READ 0 #define WRITE 1 /** * ARRAY_SIZE - get the number of elements in array @arr * @arr: array to be sized */ #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) #define u64_to_user_ptr(x) ( \ { \ typecheck(u64, (x)); \ (void __user *)(uintptr_t)(x); \ } \ ) /* * This looks more complex than it should be. But we need to * get the type for the ~ right in round_down (it needs to be * as wide as the result!), and we want to evaluate the macro * arguments just once each. */ #define __round_mask(x, y) ((__typeof__(x))((y)-1)) /** * round_up - round up to next specified power of 2 * @x: the value to round * @y: multiple to round up to (must be a power of 2) * * Rounds @x up to next multiple of @y (which must be a power of 2). * To perform arbitrary rounding up, use roundup() below. */ #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) /** * round_down - round down to next specified power of 2 * @x: the value to round * @y: multiple to round down to (must be a power of 2) * * Rounds @x down to next multiple of @y (which must be a power of 2). * To perform arbitrary rounding down, use rounddown() below. */ #define round_down(x, y) ((x) & ~__round_mask(x, y)) #define typeof_member(T, m) typeof(((T*)0)->m) #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP #define DIV_ROUND_DOWN_ULL(ll, d) \ ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; }) #define DIV_ROUND_UP_ULL(ll, d) \ DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d)) #if BITS_PER_LONG == 32 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) #else # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) #endif /** * roundup - round up to the next specified multiple * @x: the value to up * @y: multiple to round up to * * Rounds @x up to next multiple of @y. If @y will always be a power * of 2, consider using the faster round_up(). */ #define roundup(x, y) ( \ { \ typeof(y) __y = y; \ (((x) + (__y - 1)) / __y) * __y; \ } \ ) /** * rounddown - round down to next specified multiple * @x: the value to round * @y: multiple to round down to * * Rounds @x down to next multiple of @y. If @y will always be a power * of 2, consider using the faster round_down(). */ #define rounddown(x, y) ( \ { \ typeof(x) __x = (x); \ __x - (__x % (y)); \ } \ ) /* * Divide positive or negative dividend by positive or negative divisor * and round to closest integer. Result is undefined for negative * divisors if the dividend variable type is unsigned and for negative * dividends if the divisor variable type is unsigned. */ #define DIV_ROUND_CLOSEST(x, divisor)( \ { \ typeof(x) __x = x; \ typeof(divisor) __d = divisor; \ (((typeof(x))-1) > 0 || \ ((typeof(divisor))-1) > 0 || \ (((__x) > 0) == ((__d) > 0))) ? \ (((__x) + ((__d) / 2)) / (__d)) : \ (((__x) - ((__d) / 2)) / (__d)); \ } \ ) /* * Same as above but for u64 dividends. divisor must be a 32-bit * number. */ #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ { \ typeof(divisor) __d = divisor; \ unsigned long long _tmp = (x) + (__d) / 2; \ do_div(_tmp, __d); \ _tmp; \ } \ ) /* * Multiplies an integer by a fraction, while avoiding unnecessary * overflow or loss of precision. */ #define mult_frac(x, numer, denom)( \ { \ typeof(x) quot = (x) / (denom); \ typeof(x) rem = (x) % (denom); \ (quot * (numer)) + ((rem * (numer)) / (denom)); \ } \ ) #define _RET_IP_ (unsigned long)__builtin_return_address(0) #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) #define sector_div(a, b) do_div(a, b) /** * upper_32_bits - return bits 32-63 of a number * @n: the number we're accessing * * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress * the "right shift count >= width of type" warning when that quantity is * 32-bits. */ #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) /** * lower_32_bits - return bits 0-31 of a number * @n: the number we're accessing */ #define lower_32_bits(n) ((u32)((n) & 0xffffffff)) struct completion; struct pt_regs; struct user; #ifdef CONFIG_PREEMPT_VOLUNTARY extern int _cond_resched(void); # define might_resched() _cond_resched() #else # define might_resched() do { } while (0) #endif #ifdef CONFIG_DEBUG_ATOMIC_SLEEP extern void ___might_sleep(const char *file, int line, int preempt_offset); extern void __might_sleep(const char *file, int line, int preempt_offset); extern void __cant_sleep(const char *file, int line, int preempt_offset); /** * might_sleep - annotation for functions that can sleep * * this macro will print a stack trace if it is executed in an atomic * context (spinlock, irq-handler, ...). Additional sections where blocking is * not allowed can be annotated with non_block_start() and non_block_end() * pairs. * * This is a useful debugging help to be able to catch problems early and not * be bitten later when the calling function happens to sleep when it is not * supposed to. */ # define might_sleep() \ do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) /** * cant_sleep - annotation for functions that cannot sleep * * this macro will print a stack trace if it is executed with preemption enabled */ # define cant_sleep() \ do { __cant_sleep(__FILE__, __LINE__, 0); } while (0) # define sched_annotate_sleep() (current->task_state_change = 0) /** * non_block_start - annotate the start of section where sleeping is prohibited * * This is on behalf of the oom reaper, specifically when it is calling the mmu * notifiers. The problem is that if the notifier were to block on, for example, * mutex_lock() and if the process which holds that mutex were to perform a * sleeping memory allocation, the oom reaper is now blocked on completion of * that memory allocation. Other blocking calls like wait_event() pose similar * issues. */ # define non_block_start() (current->non_block_count++) /** * non_block_end - annotate the end of section where sleeping is prohibited * * Closes a section opened by non_block_start(). */ # define non_block_end() WARN_ON(current->non_block_count-- == 0) #else static inline void ___might_sleep(const char *file, int line, int preempt_offset) { } static inline void __might_sleep(const char *file, int line, int preempt_offset) { } # define might_sleep() do { might_resched(); } while (0) # define cant_sleep() do { } while (0) # define sched_annotate_sleep() do { } while (0) # define non_block_start() do { } while (0) # define non_block_end() do { } while (0) #endif #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) #ifndef CONFIG_PREEMPT_RT # define cant_migrate() cant_sleep() #else /* Placeholder for now */ # define cant_migrate() do { } while (0) #endif /** * abs - return absolute value of an argument * @x: the value. If it is unsigned type, it is converted to signed type first. * char is treated as if it was signed (regardless of whether it really is) * but the macro's return type is preserved as char. * * Return: an absolute value of x. */ #define abs(x) __abs_choose_expr(x, long long, \ __abs_choose_expr(x, long, \ __abs_choose_expr(x, int, \ __abs_choose_expr(x, short, \ __abs_choose_expr(x, char, \ __builtin_choose_expr( \ __builtin_types_compatible_p(typeof(x), char), \ (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ ((void)0))))))) #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ __builtin_types_compatible_p(typeof(x), signed type) || \ __builtin_types_compatible_p(typeof(x), unsigned type), \ ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) /** * reciprocal_scale - "scale" a value into range [0, ep_ro) * @val: value * @ep_ro: right open interval endpoint * * Perform a "reciprocal multiplication" in order to "scale" a value into * range [0, @ep_ro), where the upper interval endpoint is right-open. * This is useful, e.g. for accessing a index of an array containing * @ep_ro elements, for example. Think of it as sort of modulus, only that * the result isn't that of modulo. ;) Note that if initial input is a * small value, then result will return 0. * * Return: a result based on @val in interval [0, @ep_ro). */ static inline u32 reciprocal_scale(u32 val, u32 ep_ro) { return (u32)(((u64) val * ep_ro) >> 32); } #if defined(CONFIG_MMU) && \ (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) #define might_fault() __might_fault(__FILE__, __LINE__) void __might_fault(const char *file, int line); #else static inline void might_fault(void) { } #endif extern struct atomic_notifier_head panic_notifier_list; extern long (*panic_blink)(int state); __printf(1, 2) void panic(const char *fmt, ...) __noreturn __cold; void nmi_panic(struct pt_regs *regs, const char *msg); extern void oops_enter(void); extern void oops_exit(void); extern bool oops_may_print(void); void do_exit(long error_code) __noreturn; void complete_and_exit(struct completion *, long) __noreturn; /* Internal, do not use. */ int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); int __must_check _kstrtol(const char *s, unsigned int base, long *res); int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); int __must_check kstrtoll(const char *s, unsigned int base, long long *res); /** * kstrtoul - convert a string to an unsigned long * @s: The start of the string. The string must be null-terminated, and may also * include a single newline before its terminating null. The first character * may also be a plus sign, but not a minus sign. * @base: The number base to use. The maximum supported base is 16. If base is * given as 0, then the base of the string is automatically detected with the * conventional semantics - If it begins with 0x the number will be parsed as a * hexadecimal (case insensitive), if it otherwise begins with 0, it will be * parsed as an octal number. Otherwise it will be parsed as a decimal. * @res: Where to write the result of the conversion on success. * * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtoul(). Return code must be checked. */ static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) { /* * We want to shortcut function call, but * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. */ if (sizeof(unsigned long) == sizeof(unsigned long long) && __alignof__(unsigned long) == __alignof__(unsigned long long)) return kstrtoull(s, base, (unsigned long long *)res); else return _kstrtoul(s, base, res); } /** * kstrtol - convert a string to a long * @s: The start of the string. The string must be null-terminated, and may also * include a single newline before its terminating null. The first character * may also be a plus sign or a minus sign. * @base: The number base to use. The maximum supported base is 16. If base is * given as 0, then the base of the string is automatically detected with the * conventional semantics - If it begins with 0x the number will be parsed as a * hexadecimal (case insensitive), if it otherwise begins with 0, it will be * parsed as an octal number. Otherwise it will be parsed as a decimal. * @res: Where to write the result of the conversion on success. * * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtol(). Return code must be checked. */ static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) { /* * We want to shortcut function call, but * __builtin_types_compatible_p(long, long long) = 0. */ if (sizeof(long) == sizeof(long long) && __alignof__(long) == __alignof__(long long)) return kstrtoll(s, base, (long long *)res); else return _kstrtol(s, base, res); } int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); int __must_check kstrtoint(const char *s, unsigned int base, int *res); static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) { return kstrtoull(s, base, res); } static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) { return kstrtoll(s, base, res); } static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) { return kstrtouint(s, base, res); } static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) { return kstrtoint(s, base, res); } int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); int __must_check kstrtobool(const char *s, bool *res); int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) { return kstrtoull_from_user(s, count, base, res); } static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) { return kstrtoll_from_user(s, count, base, res); } static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) { return kstrtouint_from_user(s, count, base, res); } static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) { return kstrtoint_from_user(s, count, base, res); } /* * Use kstrto<foo> instead. * * NOTE: simple_strto<foo> does not check for the range overflow and, * depending on the input, may give interesting results. * * Use these functions if and only if you cannot use kstrto<foo>, because * the conversion ends on the first non-digit character, which may be far * beyond the supported range. It might be useful to parse the strings like * 10x50 or 12:21 without altering original string or temporary buffer in use. * Keep in mind above caveat. */ extern unsigned long simple_strtoul(const char *,char **,unsigned int); extern long simple_strtol(const char *,char **,unsigned int); extern unsigned long long simple_strtoull(const char *,char **,unsigned int); extern long long simple_strtoll(const char *,char **,unsigned int); extern int num_to_str(char *buf, int size, unsigned long long num, unsigned int width); /* lib/printf utilities */ extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); extern __printf(3, 4) int snprintf(char *buf, size_t size, const char *fmt, ...); extern __printf(3, 0) int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); extern __printf(3, 4) int scnprintf(char *buf, size_t size, const char *fmt, ...); extern __printf(3, 0) int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); extern __printf(2, 3) __malloc char *kasprintf(gfp_t gfp, const char *fmt, ...); extern __printf(2, 0) __malloc char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); extern __printf(2, 0) const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); extern __scanf(2, 3) int sscanf(const char *, const char *, ...); extern __scanf(2, 0) int vsscanf(const char *, const char *, va_list); extern int get_option(char **str, int *pint); extern char *get_options(const char *str, int nints, int *ints); extern unsigned long long memparse(const char *ptr, char **retptr); extern bool parse_option_str(const char *str, const char *option); extern char *next_arg(char *args, char **param, char **val); extern int core_kernel_text(unsigned long addr); extern int init_kernel_text(unsigned long addr); extern int core_kernel_data(unsigned long addr); extern int __kernel_text_address(unsigned long addr); extern int kernel_text_address(unsigned long addr); extern int func_ptr_is_kernel_text(void *ptr); u64 int_pow(u64 base, unsigned int exp); unsigned long int_sqrt(unsigned long); #if BITS_PER_LONG < 64 u32 int_sqrt64(u64 x); #else static inline u32 int_sqrt64(u64 x) { return (u32)int_sqrt(x); } #endif #ifdef CONFIG_SMP extern unsigned int sysctl_oops_all_cpu_backtrace; #else #define sysctl_oops_all_cpu_backtrace 0 #endif /* CONFIG_SMP */ extern void bust_spinlocks(int yes); extern int panic_timeout; extern unsigned long panic_print; extern int panic_on_oops; extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; extern int panic_on_warn; extern unsigned long panic_on_taint; extern bool panic_on_taint_nousertaint; extern int sysctl_panic_on_rcu_stall; extern int sysctl_panic_on_stackoverflow; extern bool crash_kexec_post_notifiers; /* * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It * holds a CPU number which is executing panic() currently. A value of * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). */ extern atomic_t panic_cpu; #define PANIC_CPU_INVALID -1 /* * Only to be used by arch init code. If the user over-wrote the default * CONFIG_PANIC_TIMEOUT, honor it. */ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) { if (panic_timeout == arch_default_timeout) panic_timeout = timeout; } extern const char *print_tainted(void); enum lockdep_ok { LOCKDEP_STILL_OK, LOCKDEP_NOW_UNRELIABLE }; extern void add_taint(unsigned flag, enum lockdep_ok); extern int test_taint(unsigned flag); extern unsigned long get_taint(void); extern int root_mountflags; extern bool early_boot_irqs_disabled; /* * Values used for system_state. Ordering of the states must not be changed * as code checks for <, <=, >, >= STATE. */ extern enum system_states { SYSTEM_BOOTING, SYSTEM_SCHEDULING, SYSTEM_RUNNING, SYSTEM_HALT, SYSTEM_POWER_OFF, SYSTEM_RESTART, SYSTEM_SUSPEND, } system_state; /* This cannot be an enum because some may be used in assembly source. */ #define TAINT_PROPRIETARY_MODULE 0 #define TAINT_FORCED_MODULE 1 #define TAINT_CPU_OUT_OF_SPEC 2 #define TAINT_FORCED_RMMOD 3 #define TAINT_MACHINE_CHECK 4 #define TAINT_BAD_PAGE 5 #define TAINT_USER 6 #define TAINT_DIE 7 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 #define TAINT_WARN 9 #define TAINT_CRAP 10 #define TAINT_FIRMWARE_WORKAROUND 11 #define TAINT_OOT_MODULE 12 #define TAINT_UNSIGNED_MODULE 13 #define TAINT_SOFTLOCKUP 14 #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 #define TAINT_RANDSTRUCT 17 #define TAINT_FLAGS_COUNT 18 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { char c_true; /* character printed when tainted */ char c_false; /* character printed when not tainted */ bool module; /* also show as a per-module taint flag */ }; extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; extern const char hex_asc[]; #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] static inline char *hex_byte_pack(char *buf, u8 byte) { *buf++ = hex_asc_hi(byte); *buf++ = hex_asc_lo(byte); return buf; } extern const char hex_asc_upper[]; #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] static inline char *hex_byte_pack_upper(char *buf, u8 byte) { *buf++ = hex_asc_upper_hi(byte); *buf++ = hex_asc_upper_lo(byte); return buf; } extern int hex_to_bin(char ch); extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); extern char *bin2hex(char *dst, const void *src, size_t count); bool mac_pton(const char *s, u8 *mac); /* * General tracing related utility functions - trace_printk(), * tracing_on/tracing_off and tracing_start()/tracing_stop * * Use tracing_on/tracing_off when you want to quickly turn on or off * tracing. It simply enables or disables the recording of the trace events. * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on * file, which gives a means for the kernel and userspace to interact. * Place a tracing_off() in the kernel where you want tracing to end. * From user space, examine the trace, and then echo 1 > tracing_on * to continue tracing. * * tracing_stop/tracing_start has slightly more overhead. It is used * by things like suspend to ram where disabling the recording of the * trace is not enough, but tracing must actually stop because things * like calling smp_processor_id() may crash the system. * * Most likely, you want to use tracing_on/tracing_off. */ enum ftrace_dump_mode { DUMP_NONE, DUMP_ALL, DUMP_ORIG, }; #ifdef CONFIG_TRACING void tracing_on(void); void tracing_off(void); int tracing_is_on(void); void tracing_snapshot(void); void tracing_snapshot_alloc(void); extern void tracing_start(void); extern void tracing_stop(void); static inline __printf(1, 2) void ____trace_printk_check_format(const char *fmt, ...) { } #define __trace_printk_check_format(fmt, args...) \ do { \ if (0) \ ____trace_printk_check_format(fmt, ##args); \ } while (0) /** * trace_printk - printf formatting in the ftrace buffer * @fmt: the printf format for printing * * Note: __trace_printk is an internal function for trace_printk() and * the @ip is passed in via the trace_printk() macro. * * This function allows a kernel developer to debug fast path sections * that printk is not appropriate for. By scattering in various * printk like tracing in the code, a developer can quickly see * where problems are occurring. * * This is intended as a debugging tool for the developer only. * Please refrain from leaving trace_printks scattered around in * your code. (Extra memory is used for special buffers that are * allocated when trace_printk() is used.) * * A little optimization trick is done here. If there's only one * argument, there's no need to scan the string for printf formats. * The trace_puts() will suffice. But how can we take advantage of * using trace_puts() when trace_printk() has only one argument? * By stringifying the args and checking the size we can tell * whether or not there are args. __stringify((__VA_ARGS__)) will * turn into "()\0" with a size of 3 when there are no args, anything * else will be bigger. All we need to do is define a string to this, * and then take its size and compare to 3. If it's bigger, use * do_trace_printk() otherwise, optimize it to trace_puts(). Then just * let gcc optimize the rest. */ #define trace_printk(fmt, ...) \ do { \ char _______STR[] = __stringify((__VA_ARGS__)); \ if (sizeof(_______STR) > 3) \ do_trace_printk(fmt, ##__VA_ARGS__); \ else \ trace_puts(fmt); \ } while (0) #define do_trace_printk(fmt, args...) \ do { \ static const char *trace_printk_fmt __used \ __section("__trace_printk_fmt") = \ __builtin_constant_p(fmt) ? fmt : NULL; \ \ __trace_printk_check_format(fmt, ##args); \ \ if (__builtin_constant_p(fmt)) \ __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ else \ __trace_printk(_THIS_IP_, fmt, ##args); \ } while (0) extern __printf(2, 3) int __trace_bprintk(unsigned long ip, const char *fmt, ...); extern __printf(2, 3) int __trace_printk(unsigned long ip, const char *fmt, ...); /** * trace_puts - write a string into the ftrace buffer * @str: the string to record * * Note: __trace_bputs is an internal function for trace_puts and * the @ip is passed in via the trace_puts macro. * * This is similar to trace_printk() but is made for those really fast * paths that a developer wants the least amount of "Heisenbug" effects, * where the processing of the print format is still too much. * * This function allows a kernel developer to debug fast path sections * that printk is not appropriate for. By scattering in various * printk like tracing in the code, a developer can quickly see * where problems are occurring. * * This is intended as a debugging tool for the developer only. * Please refrain from leaving trace_puts scattered around in * your code. (Extra memory is used for special buffers that are * allocated when trace_puts() is used.) * * Returns: 0 if nothing was written, positive # if string was. * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) */ #define trace_puts(str) ({ \ static const char *trace_printk_fmt __used \ __section("__trace_printk_fmt") = \ __builtin_constant_p(str) ? str : NULL; \ \ if (__builtin_constant_p(str)) \ __trace_bputs(_THIS_IP_, trace_printk_fmt); \ else \ __trace_puts(_THIS_IP_, str, strlen(str)); \ }) extern int __trace_bputs(unsigned long ip, const char *str); extern int __trace_puts(unsigned long ip, const char *str, int size); extern void trace_dump_stack(int skip); /* * The double __builtin_constant_p is because gcc will give us an error * if we try to allocate the static variable to fmt if it is not a * constant. Even with the outer if statement. */ #define ftrace_vprintk(fmt, vargs) \ do { \ if (__builtin_constant_p(fmt)) { \ static const char *trace_printk_fmt __used \ __section("__trace_printk_fmt") = \ __builtin_constant_p(fmt) ? fmt : NULL; \ \ __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ } else \ __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ } while (0) extern __printf(2, 0) int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); extern __printf(2, 0) int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); #else static inline void tracing_start(void) { } static inline void tracing_stop(void) { } static inline void trace_dump_stack(int skip) { } static inline void tracing_on(void) { } static inline void tracing_off(void) { } static inline int tracing_is_on(void) { return 0; } static inline void tracing_snapshot(void) { } static inline void tracing_snapshot_alloc(void) { } static inline __printf(1, 2) int trace_printk(const char *fmt, ...) { return 0; } static __printf(1, 0) inline int ftrace_vprintk(const char *fmt, va_list ap) { return 0; } static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #endif /* CONFIG_TRACING */ /* This counts to 12. Any more, it will return 13th argument. */ #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) #define __CONCAT(a, b) a ## b #define CONCATENATE(a, b) __CONCAT(a, b) /** * container_of - cast a member of a structure out to the containing structure * @ptr: the pointer to the member. * @type: the type of the container struct this is embedded in. * @member: the name of the member within the struct. * */ #define container_of(ptr, type, member) ({ \ void *__mptr = (void *)(ptr); \ BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ !__same_type(*(ptr), void), \ "pointer type mismatch in container_of()"); \ ((type *)(__mptr - offsetof(type, member))); }) /** * container_of_safe - cast a member of a structure out to the containing structure * @ptr: the pointer to the member. * @type: the type of the container struct this is embedded in. * @member: the name of the member within the struct. * * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. */ #define container_of_safe(ptr, type, member) ({ \ void *__mptr = (void *)(ptr); \ BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ !__same_type(*(ptr), void), \ "pointer type mismatch in container_of()"); \ IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ ((type *)(__mptr - offsetof(type, member))); }) /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ #ifdef CONFIG_FTRACE_MCOUNT_RECORD # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD #endif /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ #define VERIFY_OCTAL_PERMISSIONS(perms) \ (BUILD_BUG_ON_ZERO((perms) < 0) + \ BUILD_BUG_ON_ZERO((perms) > 0777) + \ /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ /* USER_WRITABLE >= GROUP_WRITABLE */ \ BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ /* OTHER_WRITABLE? Generally considered a bad idea. */ \ BUILD_BUG_ON_ZERO((perms) & 2) + \ (perms)) #endif
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When * requesting an interrupt without specifying a IRQF_TRIGGER, the * setting should be assumed to be "as already configured", which * may be as per machine or firmware initialisation. */ #define IRQF_TRIGGER_NONE 0x00000000 #define IRQF_TRIGGER_RISING 0x00000001 #define IRQF_TRIGGER_FALLING 0x00000002 #define IRQF_TRIGGER_HIGH 0x00000004 #define IRQF_TRIGGER_LOW 0x00000008 #define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING) #define IRQF_TRIGGER_PROBE 0x00000010 /* * These flags used only by the kernel as part of the * irq handling routines. * * IRQF_SHARED - allow sharing the irq among several devices * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur * IRQF_TIMER - Flag to mark this interrupt as timer interrupt * IRQF_PERCPU - Interrupt is per cpu * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is * registered first in a shared interrupt is considered for * performance reasons) * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished. * Used by threaded interrupts which need to keep the * irq line disabled until the threaded handler has been run. * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend. Does not guarantee * that this interrupt will wake the system from a suspended * state. See Documentation/power/suspend-and-interrupts.rst * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set * IRQF_NO_THREAD - Interrupt cannot be threaded * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device * resume time. * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this * interrupt handler after suspending interrupts. For system * wakeup devices users need to implement wakeup detection in * their interrupt handlers. */ #define IRQF_SHARED 0x00000080 #define IRQF_PROBE_SHARED 0x00000100 #define __IRQF_TIMER 0x00000200 #define IRQF_PERCPU 0x00000400 #define IRQF_NOBALANCING 0x00000800 #define IRQF_IRQPOLL 0x00001000 #define IRQF_ONESHOT 0x00002000 #define IRQF_NO_SUSPEND 0x00004000 #define IRQF_FORCE_RESUME 0x00008000 #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 #define IRQF_COND_SUSPEND 0x00040000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) /* * These values can be returned by request_any_context_irq() and * describe the context the interrupt will be run in. * * IRQC_IS_HARDIRQ - interrupt runs in hardirq context * IRQC_IS_NESTED - interrupt runs in a nested threaded context */ enum { IRQC_IS_HARDIRQ = 0, IRQC_IS_NESTED, }; typedef irqreturn_t (*irq_handler_t)(int, void *); /** * struct irqaction - per interrupt action descriptor * @handler: interrupt handler function * @name: name of the device * @dev_id: cookie to identify the device * @percpu_dev_id: cookie to identify the device * @next: pointer to the next irqaction for shared interrupts * @irq: interrupt number * @flags: flags (see IRQF_* above) * @thread_fn: interrupt handler function for threaded interrupts * @thread: thread pointer for threaded interrupts * @secondary: pointer to secondary irqaction (force threading) * @thread_flags: flags related to @thread * @thread_mask: bitmask for keeping track of @thread activity * @dir: pointer to the proc/irq/NN/name entry */ struct irqaction { irq_handler_t handler; void *dev_id; void __percpu *percpu_dev_id; struct irqaction *next; irq_handler_t thread_fn; struct task_struct *thread; struct irqaction *secondary; unsigned int irq; unsigned int flags; unsigned long thread_flags; unsigned long thread_mask; const char *name; struct proc_dir_entry *dir; } ____cacheline_internodealigned_in_smp; extern irqreturn_t no_action(int cpl, void *dev_id); /* * If a (PCI) device interrupt is not connected we set dev->irq to * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we * can distingiush that case from other error returns. * * 0x80000000 is guaranteed to be outside the available range of interrupts * and easy to distinguish from other possible incorrect values. */ #define IRQ_NOTCONNECTED (1U << 31) extern int __must_check request_threaded_irq(unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long flags, const char *name, void *dev); /** * request_irq - Add a handler for an interrupt line * @irq: The interrupt line to allocate * @handler: Function to be called when the IRQ occurs. * Primary handler for threaded interrupts * If NULL, the default primary handler is installed * @flags: Handling flags * @name: Name of the device generating this interrupt * @dev: A cookie passed to the handler function * * This call allocates an interrupt and establishes a handler; see * the documentation for request_threaded_irq() for details. */ static inline int __must_check request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev) { return request_threaded_irq(irq, handler, NULL, flags, name, dev); } extern int __must_check request_any_context_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev_id); extern int __must_check __request_percpu_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *devname, void __percpu *percpu_dev_id); extern int __must_check request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev); static inline int __must_check request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id) { return __request_percpu_irq(irq, handler, 0, devname, percpu_dev_id); } extern int __must_check request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *dev); extern const void *free_irq(unsigned int, void *); extern void free_percpu_irq(unsigned int, void __percpu *); extern const void *free_nmi(unsigned int irq, void *dev_id); extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id); struct device; extern int __must_check devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long irqflags, const char *devname, void *dev_id); static inline int __must_check devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags, devname, dev_id); } extern int __must_check devm_request_any_context_irq(struct device *dev, unsigned int irq, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id); extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id); /* * On lockdep we dont want to enable hardirqs in hardirq * context. Use local_irq_enable_in_hardirq() to annotate * kernel code that has to do this nevertheless (pretty much * the only valid case is for old/broken hardware that is * insanely slow). * * NOTE: in theory this might break fragile code that relies * on hardirq delivery - in practice we dont seem to have such * places left. So the only effect should be slightly increased * irqs-off latencies. */ #ifdef CONFIG_LOCKDEP # define local_irq_enable_in_hardirq() do { } while (0) #else # define local_irq_enable_in_hardirq() local_irq_enable() #endif extern void disable_irq_nosync(unsigned int irq); extern bool disable_hardirq(unsigned int irq); extern void disable_irq(unsigned int irq); extern void disable_percpu_irq(unsigned int irq); extern void enable_irq(unsigned int irq); extern void enable_percpu_irq(unsigned int irq, unsigned int type); extern bool irq_percpu_is_enabled(unsigned int irq); extern void irq_wake_thread(unsigned int irq, void *dev_id); extern void disable_nmi_nosync(unsigned int irq); extern void disable_percpu_nmi(unsigned int irq); extern void enable_nmi(unsigned int irq); extern void enable_percpu_nmi(unsigned int irq, unsigned int type); extern int prepare_percpu_nmi(unsigned int irq); extern void teardown_percpu_nmi(unsigned int irq); extern int irq_inject_interrupt(unsigned int irq); /* The following three functions are for the core kernel use only. */ extern void suspend_device_irqs(void); extern void resume_device_irqs(void); extern void rearm_wake_irq(unsigned int irq); /** * struct irq_affinity_notify - context for notification of IRQ affinity changes * @irq: Interrupt to which notification applies * @kref: Reference count, for internal use * @work: Work item, for internal use * @notify: Function to be called on change. This will be * called in process context. * @release: Function to be called on release. This will be * called in process context. Once registered, the * structure must only be freed when this function is * called or later. */ struct irq_affinity_notify { unsigned int irq; struct kref kref; struct work_struct work; void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask); void (*release)(struct kref *ref); }; #define IRQ_AFFINITY_MAX_SETS 4 /** * struct irq_affinity - Description for automatic irq affinity assignements * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of * the MSI(-X) vector space * @post_vectors: Don't apply affinity to @post_vectors at end of * the MSI(-X) vector space * @nr_sets: The number of interrupt sets for which affinity * spreading is required * @set_size: Array holding the size of each interrupt set * @calc_sets: Callback for calculating the number and size * of interrupt sets * @priv: Private data for usage by @calc_sets, usually a * pointer to driver/device specific data. */ struct irq_affinity { unsigned int pre_vectors; unsigned int post_vectors; unsigned int nr_sets; unsigned int set_size[IRQ_AFFINITY_MAX_SETS]; void (*calc_sets)(struct irq_affinity *, unsigned int nvecs); void *priv; }; /** * struct irq_affinity_desc - Interrupt affinity descriptor * @mask: cpumask to hold the affinity assignment * @is_managed: 1 if the interrupt is managed internally */ struct irq_affinity_desc { struct cpumask mask; unsigned int is_managed : 1; }; #if defined(CONFIG_SMP) extern cpumask_var_t irq_default_affinity; /* Internal implementation. Use the helpers below */ extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask, bool force); /** * irq_set_affinity - Set the irq affinity of a given irq * @irq: Interrupt to set affinity * @cpumask: cpumask * * Fails if cpumask does not contain an online CPU */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) { return __irq_set_affinity(irq, cpumask, false); } /** * irq_force_affinity - Force the irq affinity of a given irq * @irq: Interrupt to set affinity * @cpumask: cpumask * * Same as irq_set_affinity, but without checking the mask against * online cpus. * * Solely for low level cpu hotplug code, where we need to make per * cpu interrupts affine before the cpu becomes online. */ static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) { return __irq_set_affinity(irq, cpumask, true); } extern int irq_can_set_affinity(unsigned int irq); extern int irq_select_affinity(unsigned int irq); extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); extern int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); struct irq_affinity_desc * irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd); unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, const struct irq_affinity *affd); #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) { return -EINVAL; } static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) { return 0; } static inline int irq_can_set_affinity(unsigned int irq) { return 0; } static inline int irq_select_affinity(unsigned int irq) { return 0; } static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) { return -EINVAL; } static inline int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) { return 0; } static inline struct irq_affinity_desc * irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd) { return NULL; } static inline unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, const struct irq_affinity *affd) { return maxvec; } #endif /* CONFIG_SMP */ /* * Special lockdep variants of irq disabling/enabling. * These should be used for locking constructs that * know that a particular irq context which is disabled, * and which is the only irq-context user of a lock, * that it's safe to take the lock in the irq-disabled * section without disabling hardirqs. * * On !CONFIG_LOCKDEP they are equivalent to the normal * irq disable/enable methods. */ static inline void disable_irq_nosync_lockdep(unsigned int irq) { disable_irq_nosync(irq); #ifdef CONFIG_LOCKDEP local_irq_disable(); #endif } static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags) { disable_irq_nosync(irq); #ifdef CONFIG_LOCKDEP local_irq_save(*flags); #endif } static inline void disable_irq_lockdep(unsigned int irq) { disable_irq(irq); #ifdef CONFIG_LOCKDEP local_irq_disable(); #endif } static inline void enable_irq_lockdep(unsigned int irq) { #ifdef CONFIG_LOCKDEP local_irq_enable(); #endif enable_irq(irq); } static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags) { #ifdef CONFIG_LOCKDEP local_irq_restore(*flags); #endif enable_irq(irq); } /* IRQ wakeup (PM) control: */ extern int irq_set_irq_wake(unsigned int irq, unsigned int on); static inline int enable_irq_wake(unsigned int irq) { return irq_set_irq_wake(irq, 1); } static inline int disable_irq_wake(unsigned int irq) { return irq_set_irq_wake(irq, 0); } /* * irq_get_irqchip_state/irq_set_irqchip_state specific flags */ enum irqchip_irq_state { IRQCHIP_STATE_PENDING, /* Is interrupt pending? */ IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */ IRQCHIP_STATE_MASKED, /* Is interrupt masked? */ IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */ }; extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, bool *state); extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, bool state); #ifdef CONFIG_IRQ_FORCED_THREADING # ifdef CONFIG_PREEMPT_RT # define force_irqthreads (true) # else extern bool force_irqthreads; # endif #else #define force_irqthreads (0) #endif #ifndef local_softirq_pending #ifndef local_softirq_pending_ref #define local_softirq_pending_ref irq_stat.__softirq_pending #endif #define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref)) #define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x))) #define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x))) #endif /* local_softirq_pending */ /* Some architectures might implement lazy enabling/disabling of * interrupts. In some cases, such as stop_machine, we might want * to ensure that after a local_irq_disable(), interrupts have * really been disabled in hardware. Such architectures need to * implement the following hook. */ #ifndef hard_irq_disable #define hard_irq_disable() do { } while(0) #endif /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high frequency threaded job scheduling. For almost all the purposes tasklets are more than enough. F.e. all serial device BHs et al. should be converted to tasklets, not to softirqs. */ enum { HI_SOFTIRQ=0, TIMER_SOFTIRQ, NET_TX_SOFTIRQ, NET_RX_SOFTIRQ, BLOCK_SOFTIRQ, IRQ_POLL_SOFTIRQ, TASKLET_SOFTIRQ, SCHED_SOFTIRQ, HRTIMER_SOFTIRQ, RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */ NR_SOFTIRQS }; #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ)) /* map softirq index to softirq name. update 'softirq_to_name' in * kernel/softirq.c when adding a new softirq. */ extern const char * const softirq_to_name[NR_SOFTIRQS]; /* softirq mask and active fields moved to irq_cpustat_t in * asm/hardirq.h to get better cache usage. KAO */ struct softirq_action { void (*action)(struct softirq_action *); }; asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); #ifdef __ARCH_HAS_DO_SOFTIRQ void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void) { __do_softirq(); } #endif extern void open_softirq(int nr, void (*action)(struct softirq_action *)); extern void softirq_init(void); extern void __raise_softirq_irqoff(unsigned int nr); extern void raise_softirq_irqoff(unsigned int nr); extern void raise_softirq(unsigned int nr); DECLARE_PER_CPU(struct task_struct *, ksoftirqd); static inline struct task_struct *this_cpu_ksoftirqd(void) { return this_cpu_read(ksoftirqd); } /* Tasklets --- multithreaded analogue of BHs. This API is deprecated. Please consider using threaded IRQs instead: https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de Main feature differing them of generic softirqs: tasklet is running only on one CPU simultaneously. Main feature differing them of BHs: different tasklets may be run simultaneously on different CPUs. Properties: * If tasklet_schedule() is called, then tasklet is guaranteed to be executed on some cpu at least once after this. * If the tasklet is already scheduled, but its execution is still not started, it will be executed only once. * If this tasklet is already running on another CPU (or schedule is called from tasklet itself), it is rescheduled for later. * Tasklet is strictly serialized wrt itself, but not wrt another tasklets. If client needs some intertask synchronization, he makes it with spinlocks. */ struct tasklet_struct { struct tasklet_struct *next; unsigned long state; atomic_t count; bool use_callback; union { void (*func)(unsigned long data); void (*callback)(struct tasklet_struct *t); }; unsigned long data; }; #define DECLARE_TASKLET(name, _callback) \ struct tasklet_struct name = { \ .count = ATOMIC_INIT(0), \ .callback = _callback, \ .use_callback = true, \ } #define DECLARE_TASKLET_DISABLED(name, _callback) \ struct tasklet_struct name = { \ .count = ATOMIC_INIT(1), \ .callback = _callback, \ .use_callback = true, \ } #define from_tasklet(var, callback_tasklet, tasklet_fieldname) \ container_of(callback_tasklet, typeof(*var), tasklet_fieldname) #define DECLARE_TASKLET_OLD(name, _func) \ struct tasklet_struct name = { \ .count = ATOMIC_INIT(0), \ .func = _func, \ } #define DECLARE_TASKLET_DISABLED_OLD(name, _func) \ struct tasklet_struct name = { \ .count = ATOMIC_INIT(1), \ .func = _func, \ } enum { TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */ TASKLET_STATE_RUN /* Tasklet is running (SMP only) */ }; #ifdef CONFIG_SMP static inline int tasklet_trylock(struct tasklet_struct *t) { return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state); } static inline void tasklet_unlock(struct tasklet_struct *t) { smp_mb__before_atomic(); clear_bit(TASKLET_STATE_RUN, &(t)->state); } static inline void tasklet_unlock_wait(struct tasklet_struct *t) { while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); } } #else #define tasklet_trylock(t) 1 #define tasklet_unlock_wait(t) do { } while (0) #define tasklet_unlock(t) do { } while (0) #endif extern void __tasklet_schedule(struct tasklet_struct *t); static inline void tasklet_schedule(struct tasklet_struct *t) { if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) __tasklet_schedule(t); } extern void __tasklet_hi_schedule(struct tasklet_struct *t); static inline void tasklet_hi_schedule(struct tasklet_struct *t) { if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) __tasklet_hi_schedule(t); } static inline void tasklet_disable_nosync(struct tasklet_struct *t) { atomic_inc(&t->count); smp_mb__after_atomic(); } static inline void tasklet_disable(struct tasklet_struct *t) { tasklet_disable_nosync(t); tasklet_unlock_wait(t); smp_mb(); } static inline void tasklet_enable(struct tasklet_struct *t) { smp_mb__before_atomic(); atomic_dec(&t->count); } extern void tasklet_kill(struct tasklet_struct *t); extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu); extern void tasklet_init(struct tasklet_struct *t, void (*func)(unsigned long), unsigned long data); extern void tasklet_setup(struct tasklet_struct *t, void (*callback)(struct tasklet_struct *)); /* * Autoprobing for irqs: * * probe_irq_on() and probe_irq_off() provide robust primitives * for accurate IRQ probing during kernel initialization. They are * reasonably simple to use, are not "fooled" by spurious interrupts, * and, unlike other attempts at IRQ probing, they do not get hung on * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards). * * For reasonably foolproof probing, use them as follows: * * 1. clear and/or mask the device's internal interrupt. * 2. sti(); * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs * 4. enable the device and cause it to trigger an interrupt. * 5. wait for the device to interrupt, using non-intrusive polling or a delay. * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple * 7. service the device to clear its pending interrupt. * 8. loop again if paranoia is required. * * probe_irq_on() returns a mask of allocated irq's. * * probe_irq_off() takes the mask as a parameter, * and returns the irq number which occurred, * or zero if none occurred, or a negative irq number * if more than one irq occurred. */ #if !defined(CONFIG_GENERIC_IRQ_PROBE) static inline unsigned long probe_irq_on(void) { return 0; } static inline int probe_irq_off(unsigned long val) { return 0; } static inline unsigned int probe_irq_mask(unsigned long val) { return 0; } #else extern unsigned long probe_irq_on(void); /* returns 0 on failure */ extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */ extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */ #endif #ifdef CONFIG_PROC_FS /* Initialize /proc/irq/ */ extern void init_irq_proc(void); #else static inline void init_irq_proc(void) { } #endif #ifdef CONFIG_IRQ_TIMINGS void irq_timings_enable(void); void irq_timings_disable(void); u64 irq_timings_next_event(u64 now); #endif struct seq_file; int show_interrupts(struct seq_file *p, void *v); int arch_show_interrupts(struct seq_file *p, int prec); extern int early_irq_init(void); extern int arch_probe_nr_irqs(void); extern int arch_early_irq_init(void); /* * We want to know which function is an entrypoint of a hardirq or a softirq. */ #ifndef __irq_entry # define __irq_entry __section(".irqentry.text") #endif #define __softirq_entry __section(".softirqentry.text") #endif
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_SWAP_H #define _LINUX_SWAP_H #include <linux/spinlock.h> #include <linux/linkage.h> #include <linux/mmzone.h> #include <linux/list.h> #include <linux/memcontrol.h> #include <linux/sched.h> #include <linux/node.h> #include <linux/fs.h> #include <linux/atomic.h> #include <linux/page-flags.h> #include <asm/page.h> struct notifier_block; struct bio; struct pagevec; #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ #define SWAP_FLAG_PRIO_MASK 0x7fff #define SWAP_FLAG_PRIO_SHIFT 0 #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ SWAP_FLAG_DISCARD_PAGES) #define SWAP_BATCH 64 static inline int current_is_kswapd(void) { return current->flags & PF_KSWAPD; } /* * MAX_SWAPFILES defines the maximum number of swaptypes: things which can * be swapped to. The swap type and the offset into that swap type are * encoded into pte's and into pgoff_t's in the swapcache. Using five bits * for the type means that the maximum number of swapcache pages is 27 bits * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs * the type/offset into the pte as 5/27 as well. */ #define MAX_SWAPFILES_SHIFT 5 /* * Use some of the swap files numbers for other purposes. This * is a convenient way to hook into the VM to trigger special * actions on faults. */ /* * Unaddressable device memory support. See include/linux/hmm.h and * Documentation/vm/hmm.rst. Short description is we need struct pages for * device memory that is unaddressable (inaccessible) by CPU, so that we can * migrate part of a process memory to device memory. * * When a page is migrated from CPU to device, we set the CPU page table entry * to a special SWP_DEVICE_* entry. */ #ifdef CONFIG_DEVICE_PRIVATE #define SWP_DEVICE_NUM 2 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) #else #define SWP_DEVICE_NUM 0 #endif /* * NUMA node memory migration support */ #ifdef CONFIG_MIGRATION #define SWP_MIGRATION_NUM 2 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) #else #define SWP_MIGRATION_NUM 0 #endif /* * Handling of hardware poisoned pages with memory corruption. */ #ifdef CONFIG_MEMORY_FAILURE #define SWP_HWPOISON_NUM 1 #define SWP_HWPOISON MAX_SWAPFILES #else #define SWP_HWPOISON_NUM 0 #endif #define MAX_SWAPFILES \ ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) /* * Magic header for a swap area. The first part of the union is * what the swap magic looks like for the old (limited to 128MB) * swap area format, the second part of the union adds - in the * old reserved area - some extra information. Note that the first * kilobyte is reserved for boot loader or disk label stuff... * * Having the magic at the end of the PAGE_SIZE makes detecting swap * areas somewhat tricky on machines that support multiple page sizes. * For 2.5 we'll probably want to move the magic to just beyond the * bootbits... */ union swap_header { struct { char reserved[PAGE_SIZE - 10]; char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ } magic; struct { char bootbits[1024]; /* Space for disklabel etc. */ __u32 version; __u32 last_page; __u32 nr_badpages; unsigned char sws_uuid[16]; unsigned char sws_volume[16]; __u32 padding[117]; __u32 badpages[1]; } info; }; /* * current->reclaim_state points to one of these when a task is running * memory reclaim */ struct reclaim_state { unsigned long reclaimed_slab; }; #ifdef __KERNEL__ struct address_space; struct sysinfo; struct writeback_control; struct zone; /* * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of * disk blocks. A list of swap extents maps the entire swapfile. (Where the * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart * from setup, they're handled identically. * * We always assume that blocks are of size PAGE_SIZE. */ struct swap_extent { struct rb_node rb_node; pgoff_t start_page; pgoff_t nr_pages; sector_t start_block; }; /* * Max bad pages in the new format.. */ #define MAX_SWAP_BADPAGES \ ((offsetof(union swap_header, magic.magic) - \ offsetof(union swap_header, info.badpages)) / sizeof(int)) enum { SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ SWP_BLKDEV = (1 << 6), /* its a block device */ SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ SWP_VALID = (1 << 13), /* swap is valid to be operated on? */ /* add others here before... */ SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ }; #define SWAP_CLUSTER_MAX 32UL #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX /* Bit flag in swap_map */ #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ /* Special value in first swap_map */ #define SWAP_MAP_MAX 0x3e /* Max count */ #define SWAP_MAP_BAD 0x3f /* Note page is bad */ #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ /* Special value in each swap_map continuation */ #define SWAP_CONT_MAX 0x7f /* Max count */ /* * We use this to track usage of a cluster. A cluster is a block of swap disk * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All * free clusters are organized into a list. We fetch an entry from the list to * get a free cluster. * * The data field stores next cluster if the cluster is free or cluster usage * counter otherwise. The flags field determines if a cluster is free. This is * protected by swap_info_struct.lock. */ struct swap_cluster_info { spinlock_t lock; /* * Protect swap_cluster_info fields * and swap_info_struct->swap_map * elements correspond to the swap * cluster */ unsigned int data:24; unsigned int flags:8; }; #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ /* * We assign a cluster to each CPU, so each CPU can allocate swap entry from * its own cluster and swapout sequentially. The purpose is to optimize swapout * throughput. */ struct percpu_cluster { struct swap_cluster_info index; /* Current cluster index */ unsigned int next; /* Likely next allocation offset */ }; struct swap_cluster_list { struct swap_cluster_info head; struct swap_cluster_info tail; }; /* * The in-memory structure used to track swap areas. */ struct swap_info_struct { unsigned long flags; /* SWP_USED etc: see above */ signed short prio; /* swap priority of this type */ struct plist_node list; /* entry in swap_active_head */ signed char type; /* strange name for an index */ unsigned int max; /* extent of the swap_map */ unsigned char *swap_map; /* vmalloc'ed array of usage counts */ struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ struct swap_cluster_list free_clusters; /* free clusters list */ unsigned int lowest_bit; /* index of first free in swap_map */ unsigned int highest_bit; /* index of last free in swap_map */ unsigned int pages; /* total of usable pages of swap */ unsigned int inuse_pages; /* number of those currently in use */ unsigned int cluster_next; /* likely index for next allocation */ unsigned int cluster_nr; /* countdown to next cluster search */ unsigned int __percpu *cluster_next_cpu; /*percpu index for next allocation */ struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ struct rb_root swap_extent_root;/* root of the swap extent rbtree */ struct block_device *bdev; /* swap device or bdev of swap file */ struct file *swap_file; /* seldom referenced */ unsigned int old_block_size; /* seldom referenced */ #ifdef CONFIG_FRONTSWAP unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ atomic_t frontswap_pages; /* frontswap pages in-use counter */ #endif spinlock_t lock; /* * protect map scan related fields like * swap_map, lowest_bit, highest_bit, * inuse_pages, cluster_next, * cluster_nr, lowest_alloc, * highest_alloc, free/discard cluster * list. other fields are only changed * at swapon/swapoff, so are protected * by swap_lock. changing flags need * hold this lock and swap_lock. If * both locks need hold, hold swap_lock * first. */ spinlock_t cont_lock; /* * protect swap count continuation page * list. */ struct work_struct discard_work; /* discard worker */ struct swap_cluster_list discard_clusters; /* discard clusters list */ struct plist_node avail_lists[]; /* * entries in swap_avail_heads, one * entry per node. * Must be last as the number of the * array is nr_node_ids, which is not * a fixed value so have to allocate * dynamically. * And it has to be an array so that * plist_for_each_* can work. */ }; #ifdef CONFIG_64BIT #define SWAP_RA_ORDER_CEILING 5 #else /* Avoid stack overflow, because we need to save part of page table */ #define SWAP_RA_ORDER_CEILING 3 #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) #endif struct vma_swap_readahead { unsigned short win; unsigned short offset; unsigned short nr_pte; #ifdef CONFIG_64BIT pte_t *ptes; #else pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; #endif }; /* linux/mm/workingset.c */ void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg); void workingset_refault(struct page *page, void *shadow); void workingset_activation(struct page *page); /* Only track the nodes of mappings with shadow entries */ void workingset_update_node(struct xa_node *node); #define mapping_set_update(xas, mapping) do { \ if (!dax_mapping(mapping) && !shmem_mapping(mapping)) \ xas_set_update(xas, workingset_update_node); \ } while (0) /* linux/mm/page_alloc.c */ extern unsigned long totalreserve_pages; extern unsigned long nr_free_buffer_pages(void); /* Definition of global_zone_page_state not available yet */ #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) /* linux/mm/swap.c */ extern void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages); extern void lru_note_cost_page(struct page *); extern void lru_cache_add(struct page *); extern void lru_add_page_tail(struct page *page, struct page *page_tail, struct lruvec *lruvec, struct list_head *head); extern void mark_page_accessed(struct page *); extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_cpu_zone(struct zone *zone); extern void lru_add_drain_all(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_file_page(struct page *page); extern void deactivate_page(struct page *page); extern void mark_page_lazyfree(struct page *page); extern void swap_setup(void); extern void lru_cache_add_inactive_or_unevictable(struct page *page, struct vm_area_struct *vma); /* linux/mm/vmscan.c */ extern unsigned long zone_reclaimable_pages(struct zone *zone); extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *mask); extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, unsigned long nr_pages, gfp_t gfp_mask, bool may_swap); extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, gfp_t gfp_mask, bool noswap, pg_data_t *pgdat, unsigned long *nr_scanned); extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; extern int remove_mapping(struct address_space *mapping, struct page *page); extern unsigned long reclaim_pages(struct list_head *page_list); #ifdef CONFIG_NUMA extern int node_reclaim_mode; extern int sysctl_min_unmapped_ratio; extern int sysctl_min_slab_ratio; #else #define node_reclaim_mode 0 #endif extern void check_move_unevictable_pages(struct pagevec *pvec); extern int kswapd_run(int nid); extern void kswapd_stop(int nid); #ifdef CONFIG_SWAP #include <linux/blk_types.h> /* for bio_end_io_t */ /* linux/mm/page_io.c */ extern int swap_readpage(struct page *page, bool do_poll); extern int swap_writepage(struct page *page, struct writeback_control *wbc); extern void end_swap_bio_write(struct bio *bio); extern int __swap_writepage(struct page *page, struct writeback_control *wbc, bio_end_io_t end_write_func); extern int swap_set_page_dirty(struct page *page); int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, unsigned long nr_pages, sector_t start_block); int generic_swapfile_activate(struct swap_info_struct *, struct file *, sector_t *); /* linux/mm/swap_state.c */ /* One swap address space for each 64M swap space */ #define SWAP_ADDRESS_SPACE_SHIFT 14 #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) extern struct address_space *swapper_spaces[]; #define swap_address_space(entry) \ (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ >> SWAP_ADDRESS_SPACE_SHIFT]) extern unsigned long total_swapcache_pages(void); extern void show_swap_cache_info(void); extern int add_to_swap(struct page *page); extern void *get_shadow_from_swap_cache(swp_entry_t entry); extern int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp, void **shadowp); extern void __delete_from_swap_cache(struct page *page, swp_entry_t entry, void *shadow); extern void delete_from_swap_cache(struct page *); extern void clear_shadow_from_swap_cache(int type, unsigned long begin, unsigned long end); extern void free_page_and_swap_cache(struct page *); extern void free_pages_and_swap_cache(struct page **, int); extern struct page *lookup_swap_cache(swp_entry_t entry, struct vm_area_struct *vma, unsigned long addr); struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index); extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, struct vm_area_struct *vma, unsigned long addr, bool do_poll); extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, struct vm_area_struct *vma, unsigned long addr, bool *new_page_allocated); extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, struct vm_fault *vmf); extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, struct vm_fault *vmf); /* linux/mm/swapfile.c */ extern atomic_long_t nr_swap_pages; extern long total_swap_pages; extern atomic_t nr_rotate_swap; extern bool has_usable_swap(void); /* Swap 50% full? Release swapcache more aggressively.. */ static inline bool vm_swap_full(void) { return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; } static inline long get_nr_swap_pages(void) { return atomic_long_read(&nr_swap_pages); } extern void si_swapinfo(struct sysinfo *); extern swp_entry_t get_swap_page(struct page *page); extern void put_swap_page(struct page *page, swp_entry_t entry); extern swp_entry_t get_swap_page_of_type(int); extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); extern int add_swap_count_continuation(swp_entry_t, gfp_t); extern void swap_shmem_alloc(swp_entry_t); extern int swap_duplicate(swp_entry_t); extern int swapcache_prepare(swp_entry_t); extern void swap_free(swp_entry_t); extern void swapcache_free_entries(swp_entry_t *entries, int n); extern int free_swap_and_cache(swp_entry_t); int swap_type_of(dev_t device, sector_t offset); int find_first_swap(dev_t *device); extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); extern int page_swapcount(struct page *); extern int __swap_count(swp_entry_t entry); extern int __swp_swapcount(swp_entry_t entry); extern int swp_swapcount(swp_entry_t entry); extern struct swap_info_struct *page_swap_info(struct page *); extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); extern bool reuse_swap_page(struct page *, int *); extern int try_to_free_swap(struct page *); struct backing_dev_info; extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); extern void exit_swap_address_space(unsigned int type); extern struct swap_info_struct *get_swap_device(swp_entry_t entry); sector_t swap_page_sector(struct page *page); static inline void put_swap_device(struct swap_info_struct *si) { rcu_read_unlock(); } #else /* CONFIG_SWAP */ static inline int swap_readpage(struct page *page, bool do_poll) { return 0; } static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) { return NULL; } #define swap_address_space(entry) (NULL) #define get_nr_swap_pages() 0L #define total_swap_pages 0L #define total_swapcache_pages() 0UL #define vm_swap_full() 0 #define si_swapinfo(val) \ do { (val)->freeswap = (val)->totalswap = 0; } while (0) /* only sparc can not include linux/pagemap.h in this file * so leave put_page and release_pages undeclared... */ #define free_page_and_swap_cache(page) \ put_page(page) #define free_pages_and_swap_cache(pages, nr) \ release_pages((pages), (nr)); static inline void show_swap_cache_info(void) { } #define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) #define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) { return 0; } static inline void swap_shmem_alloc(swp_entry_t swp) { } static inline int swap_duplicate(swp_entry_t swp) { return 0; } static inline void swap_free(swp_entry_t swp) { } static inline void put_swap_page(struct page *page, swp_entry_t swp) { } static inline struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, struct vm_fault *vmf) { return NULL; } static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, struct vm_fault *vmf) { return NULL; } static inline int swap_writepage(struct page *p, struct writeback_control *wbc) { return 0; } static inline struct page *lookup_swap_cache(swp_entry_t swp, struct vm_area_struct *vma, unsigned long addr) { ret