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 /* SPDX-License-Identifier: GPL-2.0 */ /* File: linux/posix_acl.h (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org> */ #ifndef __LINUX_POSIX_ACL_H #define __LINUX_POSIX_ACL_H #include <linux/bug.h> #include <linux/slab.h> #include <linux/rcupdate.h> #include <linux/refcount.h> #include <uapi/linux/posix_acl.h> struct posix_acl_entry { short e_tag; unsigned short e_perm; union { kuid_t e_uid; kgid_t e_gid; }; }; struct posix_acl { refcount_t a_refcount; struct rcu_head a_rcu; unsigned int a_count; struct posix_acl_entry a_entries[]; }; #define FOREACH_ACL_ENTRY(pa, acl, pe) \ for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++) /* * Duplicate an ACL handle. */ static inline struct posix_acl * posix_acl_dup(struct posix_acl *acl) { if (acl) refcount_inc(&acl->a_refcount); return acl; } /* * Free an ACL handle. */ static inline void posix_acl_release(struct posix_acl *acl) { if (acl && refcount_dec_and_test(&acl->a_refcount)) kfree_rcu(acl, a_rcu); } /* posix_acl.c */ extern void posix_acl_init(struct posix_acl *, int); extern struct posix_acl *posix_acl_alloc(int, gfp_t); extern int posix_acl_valid(struct user_namespace *, const struct posix_acl *); extern int posix_acl_permission(struct inode *, const struct posix_acl *, int); extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t); extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *); extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *); extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t); extern struct posix_acl *get_posix_acl(struct inode *, int); extern int set_posix_acl(struct inode *, int, struct posix_acl *); #ifdef CONFIG_FS_POSIX_ACL extern int posix_acl_chmod(struct inode *, umode_t); extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **, struct posix_acl **); extern int posix_acl_update_mode(struct inode *, umode_t *, struct posix_acl **); extern int simple_set_acl(struct inode *, struct posix_acl *, int); extern int simple_acl_create(struct inode *, struct inode *); struct posix_acl *get_cached_acl(struct inode *inode, int type); struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type); void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl); void forget_cached_acl(struct inode *inode, int type); void forget_all_cached_acls(struct inode *inode); static inline void cache_no_acl(struct inode *inode) { inode->i_acl = NULL; inode->i_default_acl = NULL; } #else static inline int posix_acl_chmod(struct inode *inode, umode_t mode) { return 0; } #define simple_set_acl NULL static inline int simple_acl_create(struct inode *dir, struct inode *inode) { return 0; } static inline void cache_no_acl(struct inode *inode) { } static inline int posix_acl_create(struct inode *inode, umode_t *mode, struct posix_acl **default_acl, struct posix_acl **acl) { *default_acl = *acl = NULL; return 0; } static inline void forget_all_cached_acls(struct inode *inode) { } #endif /* CONFIG_FS_POSIX_ACL */ struct posix_acl *get_acl(struct inode *inode, int type); #endif /* __LINUX_POSIX_ACL_H */
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1393 1394 1395 // SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/open.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/string.h> #include <linux/mm.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/fsnotify.h> #include <linux/module.h> #include <linux/tty.h> #include <linux/namei.h> #include <linux/backing-dev.h> #include <linux/capability.h> #include <linux/securebits.h> #include <linux/security.h> #include <linux/mount.h> #include <linux/fcntl.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/fs.h> #include <linux/personality.h> #include <linux/pagemap.h> #include <linux/syscalls.h> #include <linux/rcupdate.h> #include <linux/audit.h> #include <linux/falloc.h> #include <linux/fs_struct.h> #include <linux/ima.h> #include <linux/dnotify.h> #include <linux/compat.h> #include "internal.h" int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, struct file *filp) { int ret; struct iattr newattrs; /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ if (length < 0) return -EINVAL; newattrs.ia_size = length; newattrs.ia_valid = ATTR_SIZE | time_attrs; if (filp) { newattrs.ia_file = filp; newattrs.ia_valid |= ATTR_FILE; } /* Remove suid, sgid, and file capabilities on truncate too */ ret = dentry_needs_remove_privs(dentry); if (ret < 0) return ret; if (ret) newattrs.ia_valid |= ret | ATTR_FORCE; inode_lock(dentry->d_inode); /* Note any delegations or leases have already been broken: */ ret = notify_change(dentry, &newattrs, NULL); inode_unlock(dentry->d_inode); return ret; } long vfs_truncate(const struct path *path, loff_t length) { struct inode *inode; long error; inode = path->dentry->d_inode; /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ if (S_ISDIR(inode->i_mode)) return -EISDIR; if (!S_ISREG(inode->i_mode)) return -EINVAL; error = mnt_want_write(path->mnt); if (error) goto out; error = inode_permission(inode, MAY_WRITE); if (error) goto mnt_drop_write_and_out; error = -EPERM; if (IS_APPEND(inode)) goto mnt_drop_write_and_out; error = get_write_access(inode); if (error) goto mnt_drop_write_and_out; /* * Make sure that there are no leases. get_write_access() protects * against the truncate racing with a lease-granting setlease(). */ error = break_lease(inode, O_WRONLY); if (error) goto put_write_and_out; error = locks_verify_truncate(inode, NULL, length); if (!error) error = security_path_truncate(path); if (!error) error = do_truncate(path->dentry, length, 0, NULL); put_write_and_out: put_write_access(inode); mnt_drop_write_and_out: mnt_drop_write(path->mnt); out: return error; } EXPORT_SYMBOL_GPL(vfs_truncate); long do_sys_truncate(const char __user *pathname, loff_t length) { unsigned int lookup_flags = LOOKUP_FOLLOW; struct path path; int error; if (length < 0) /* sorry, but loff_t says... */ return -EINVAL; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (!error) { error = vfs_truncate(&path, length); path_put(&path); } if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } return error; } SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) { return do_sys_truncate(path, length); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) { return do_sys_truncate(path, length); } #endif long do_sys_ftruncate(unsigned int fd, loff_t length, int small) { struct inode *inode; struct dentry *dentry; struct fd f; int error; error = -EINVAL; if (length < 0) goto out; error = -EBADF; f = fdget(fd); if (!f.file) goto out; /* explicitly opened as large or we are on 64-bit box */ if (f.file->f_flags & O_LARGEFILE) small = 0; dentry = f.file->f_path.dentry; inode = dentry->d_inode; error = -EINVAL; if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) goto out_putf; error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) goto out_putf; error = -EPERM; /* Check IS_APPEND on real upper inode */ if (IS_APPEND(file_inode(f.file))) goto out_putf; sb_start_write(inode->i_sb); error = locks_verify_truncate(inode, f.file, length); if (!error) error = security_path_truncate(&f.file->f_path); if (!error) error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file); sb_end_write(inode->i_sb); out_putf: fdput(f); out: return error; } SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) { return do_sys_ftruncate(fd, length, 1); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) { return do_sys_ftruncate(fd, length, 1); } #endif /* LFS versions of truncate are only needed on 32 bit machines */ #if BITS_PER_LONG == 32 SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) { return do_sys_truncate(path, length); } SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) { return do_sys_ftruncate(fd, length, 0); } #endif /* BITS_PER_LONG == 32 */ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); long ret; if (offset < 0 || len <= 0) return -EINVAL; /* Return error if mode is not supported */ if (mode & ~FALLOC_FL_SUPPORTED_MASK) return -EOPNOTSUPP; /* Punch hole and zero range are mutually exclusive */ if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) return -EOPNOTSUPP; /* Punch hole must have keep size set */ if ((mode & FALLOC_FL_PUNCH_HOLE) && !(mode & FALLOC_FL_KEEP_SIZE)) return -EOPNOTSUPP; /* Collapse range should only be used exclusively. */ if ((mode & FALLOC_FL_COLLAPSE_RANGE) && (mode & ~FALLOC_FL_COLLAPSE_RANGE)) return -EINVAL; /* Insert range should only be used exclusively. */ if ((mode & FALLOC_FL_INSERT_RANGE) && (mode & ~FALLOC_FL_INSERT_RANGE)) return -EINVAL; /* Unshare range should only be used with allocate mode. */ if ((mode & FALLOC_FL_UNSHARE_RANGE) && (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) return -EINVAL; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; /* * We can only allow pure fallocate on append only files */ if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) return -EPERM; if (IS_IMMUTABLE(inode)) return -EPERM; /* * We cannot allow any fallocate operation on an active swapfile */ if (IS_SWAPFILE(inode)) return -ETXTBSY; /* * Revalidate the write permissions, in case security policy has * changed since the files were opened. */ ret = security_file_permission(file, MAY_WRITE); if (ret) return ret; if (S_ISFIFO(inode->i_mode)) return -ESPIPE; if (S_ISDIR(inode->i_mode)) return -EISDIR; if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) return -ENODEV; /* Check for wrap through zero too */ if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) return -EFBIG; if (!file->f_op->fallocate) return -EOPNOTSUPP; file_start_write(file); ret = file->f_op->fallocate(file, mode, offset, len); /* * Create inotify and fanotify events. * * To keep the logic simple always create events if fallocate succeeds. * This implies that events are even created if the file size remains * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. */ if (ret == 0) fsnotify_modify(file); file_end_write(file); return ret; } EXPORT_SYMBOL_GPL(vfs_fallocate); int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len) { struct fd f = fdget(fd); int error = -EBADF; if (f.file) { error = vfs_fallocate(f.file, mode, offset, len); fdput(f); } return error; } SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) { return ksys_fallocate(fd, mode, offset, len); } /* * access() needs to use the real uid/gid, not the effective uid/gid. * We do this by temporarily clearing all FS-related capabilities and * switching the fsuid/fsgid around to the real ones. */ static const struct cred *access_override_creds(void) { const struct cred *old_cred; struct cred *override_cred; override_cred = prepare_creds(); if (!override_cred) return NULL; override_cred->fsuid = override_cred->uid; override_cred->fsgid = override_cred->gid; if (!issecure(SECURE_NO_SETUID_FIXUP)) { /* Clear the capabilities if we switch to a non-root user */ kuid_t root_uid = make_kuid(override_cred->user_ns, 0); if (!uid_eq(override_cred->uid, root_uid)) cap_clear(override_cred->cap_effective); else override_cred->cap_effective = override_cred->cap_permitted; } /* * The new set of credentials can *only* be used in * task-synchronous circumstances, and does not need * RCU freeing, unless somebody then takes a separate * reference to it. * * NOTE! This is _only_ true because this credential * is used purely for override_creds() that installs * it as the subjective cred. Other threads will be * accessing ->real_cred, not the subjective cred. * * If somebody _does_ make a copy of this (using the * 'get_current_cred()' function), that will clear the * non_rcu field, because now that other user may be * expecting RCU freeing. But normal thread-synchronous * cred accesses will keep things non-RCY. */ override_cred->non_rcu = 1; old_cred = override_creds(override_cred); /* override_cred() gets its own ref */ put_cred(override_cred); return old_cred; } static long do_faccessat(int dfd, const char __user *filename, int mode, int flags) { struct path path; struct inode *inode; int res; unsigned int lookup_flags = LOOKUP_FOLLOW; const struct cred *old_cred = NULL; if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ return -EINVAL; if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) return -EINVAL; if (flags & AT_SYMLINK_NOFOLLOW) lookup_flags &= ~LOOKUP_FOLLOW; if (flags & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; if (!(flags & AT_EACCESS)) { old_cred = access_override_creds(); if (!old_cred) return -ENOMEM; } retry: res = user_path_at(dfd, filename, lookup_flags, &path); if (res) goto out; inode = d_backing_inode(path.dentry); if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { /* * MAY_EXEC on regular files is denied if the fs is mounted * with the "noexec" flag. */ res = -EACCES; if (path_noexec(&path)) goto out_path_release; } res = inode_permission(inode, mode | MAY_ACCESS); /* SuS v2 requires we report a read only fs too */ if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) goto out_path_release; /* * This is a rare case where using __mnt_is_readonly() * is OK without a mnt_want/drop_write() pair. Since * no actual write to the fs is performed here, we do * not need to telegraph to that to anyone. * * By doing this, we accept that this access is * inherently racy and know that the fs may change * state before we even see this result. */ if (__mnt_is_readonly(path.mnt)) res = -EROFS; out_path_release: path_put(&path); if (retry_estale(res, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: if (old_cred) revert_creds(old_cred); return res; } SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) { return do_faccessat(dfd, filename, mode, 0); } SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode, int, flags) { return do_faccessat(dfd, filename, mode, flags); } SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) { return do_faccessat(AT_FDCWD, filename, mode, 0); } SYSCALL_DEFINE1(chdir, const char __user *, filename) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; retry: error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); if (error) goto out; error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; set_fs_pwd(current->fs, &path); dput_and_out: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; } SYSCALL_DEFINE1(fchdir, unsigned int, fd) { struct fd f = fdget_raw(fd); int error; error = -EBADF; if (!f.file) goto out; error = -ENOTDIR; if (!d_can_lookup(f.file->f_path.dentry)) goto out_putf; error = inode_permission(file_inode(f.file), MAY_EXEC | MAY_CHDIR); if (!error) set_fs_pwd(current->fs, &f.file->f_path); out_putf: fdput(f); out: return error; } SYSCALL_DEFINE1(chroot, const char __user *, filename) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; retry: error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); if (error) goto out; error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; error = -EPERM; if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) goto dput_and_out; error = security_path_chroot(&path); if (error) goto dput_and_out; set_fs_root(current->fs, &path); error = 0; dput_and_out: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; } int chmod_common(const struct path *path, umode_t mode) { struct inode *inode = path->dentry->d_inode; struct inode *delegated_inode = NULL; struct iattr newattrs; int error; error = mnt_want_write(path->mnt); if (error) return error; retry_deleg: inode_lock(inode); error = security_path_chmod(path, mode); if (error) goto out_unlock; newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; error = notify_change(path->dentry, &newattrs, &delegated_inode); out_unlock: inode_unlock(inode); if (delegated_inode) { error = break_deleg_wait(&delegated_inode); if (!error) goto retry_deleg; } mnt_drop_write(path->mnt); return error; } int vfs_fchmod(struct file *file, umode_t mode) { audit_file(file); return chmod_common(&file->f_path, mode); } SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) { struct fd f = fdget(fd); int err = -EBADF; if (f.file) { err = vfs_fchmod(f.file, mode); fdput(f); } return err; } static int do_fchmodat(int dfd, const char __user *filename, umode_t mode) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (!error) { error = chmod_common(&path, mode); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } } return error; } SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) { return do_fchmodat(dfd, filename, mode); } SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) { return do_fchmodat(AT_FDCWD, filename, mode); } int chown_common(const struct path *path, uid_t user, gid_t group) { struct inode *inode = path->dentry->d_inode; struct inode *delegated_inode = NULL; int error; struct iattr newattrs; kuid_t uid; kgid_t gid; uid = make_kuid(current_user_ns(), user); gid = make_kgid(current_user_ns(), group); retry_deleg: newattrs.ia_valid = ATTR_CTIME; if (user != (uid_t) -1) { if (!uid_valid(uid)) return -EINVAL; newattrs.ia_valid |= ATTR_UID; newattrs.ia_uid = uid; } if (group != (gid_t) -1) { if (!gid_valid(gid)) return -EINVAL; newattrs.ia_valid |= ATTR_GID; newattrs.ia_gid = gid; } if (!S_ISDIR(inode->i_mode)) newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; inode_lock(inode); error = security_path_chown(path, uid, gid); if (!error) error = notify_change(path->dentry, &newattrs, &delegated_inode); inode_unlock(inode); if (delegated_inode) { error = break_deleg_wait(&delegated_inode); if (!error) goto retry_deleg; } return error; } int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, int flag) { struct path path; int error = -EINVAL; int lookup_flags; if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) goto out; lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; if (flag & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (error) goto out; error = mnt_want_write(path.mnt); if (error) goto out_release; error = chown_common(&path, user, group); mnt_drop_write(path.mnt); out_release: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; } SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, gid_t, group, int, flag) { return do_fchownat(dfd, filename, user, group, flag); } SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { return do_fchownat(AT_FDCWD, filename, user, group, 0); } SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) { return do_fchownat(AT_FDCWD, filename, user, group, AT_SYMLINK_NOFOLLOW); } int vfs_fchown(struct file *file, uid_t user, gid_t group) { int error; error = mnt_want_write_file(file); if (error) return error; audit_file(file); error = chown_common(&file->f_path, user, group); mnt_drop_write_file(file); return error; } int ksys_fchown(unsigned int fd, uid_t user, gid_t group) { struct fd f = fdget(fd); int error = -EBADF; if (f.file) { error = vfs_fchown(f.file, user, group); fdput(f); } return error; } SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) { return ksys_fchown(fd, user, group); } static int do_dentry_open(struct file *f, struct inode *inode, int (*open)(struct inode *, struct file *)) { static const struct file_operations empty_fops = {}; int error; path_get(&f->f_path); f->f_inode = inode; f->f_mapping = inode->i_mapping; f->f_wb_err = filemap_sample_wb_err(f->f_mapping); f->f_sb_err = file_sample_sb_err(f); if (unlikely(f->f_flags & O_PATH)) { f->f_mode = FMODE_PATH | FMODE_OPENED; f->f_op = &empty_fops; return 0; } if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { error = get_write_access(inode); if (unlikely(error)) goto cleanup_file; error = __mnt_want_write(f->f_path.mnt); if (unlikely(error)) { put_write_access(inode); goto cleanup_file; } f->f_mode |= FMODE_WRITER; } /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) f->f_mode |= FMODE_ATOMIC_POS; f->f_op = fops_get(inode->i_fop); if (WARN_ON(!f->f_op)) { error = -ENODEV; goto cleanup_all; } error = security_file_open(f); if (error) goto cleanup_all; error = break_lease(locks_inode(f), f->f_flags); if (error) goto cleanup_all; /* normally all 3 are set; ->open() can clear them if needed */ f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; if (!open) open = f->f_op->open; if (open) { error = open(inode, f); if (error) goto cleanup_all; } f->f_mode |= FMODE_OPENED; if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) i_readcount_inc(inode); if ((f->f_mode & FMODE_READ) && likely(f->f_op->read || f->f_op->read_iter)) f->f_mode |= FMODE_CAN_READ; if ((f->f_mode & FMODE_WRITE) && likely(f->f_op->write || f->f_op->write_iter)) f->f_mode |= FMODE_CAN_WRITE; f->f_write_hint = WRITE_LIFE_NOT_SET; f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); /* NB: we're sure to have correct a_ops only after f_op->open */ if (f->f_flags & O_DIRECT) { if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) return -EINVAL; } /* * XXX: Huge page cache doesn't support writing yet. Drop all page * cache for this file before processing writes. */ if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping)) truncate_pagecache(inode, 0); return 0; cleanup_all: if (WARN_ON_ONCE(error > 0)) error = -EINVAL; fops_put(f->f_op); if (f->f_mode & FMODE_WRITER) { put_write_access(inode); __mnt_drop_write(f->f_path.mnt); } cleanup_file: path_put(&f->f_path); f->f_path.mnt = NULL; f->f_path.dentry = NULL; f->f_inode = NULL; return error; } /** * finish_open - finish opening a file * @file: file pointer * @dentry: pointer to dentry * @open: open callback * @opened: state of open * * This can be used to finish opening a file passed to i_op->atomic_open(). * * If the open callback is set to NULL, then the standard f_op->open() * filesystem callback is substituted. * * NB: the dentry reference is _not_ consumed. If, for example, the dentry is * the return value of d_splice_alias(), then the caller needs to perform dput() * on it after finish_open(). * * Returns zero on success or -errno if the open failed. */ int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *)) { BUG_ON(file->f_mode & FMODE_OPENED); /* once it's opened, it's opened */ file->f_path.dentry = dentry; return do_dentry_open(file, d_backing_inode(dentry), open); } EXPORT_SYMBOL(finish_open); /** * finish_no_open - finish ->atomic_open() without opening the file * * @file: file pointer * @dentry: dentry or NULL (as returned from ->lookup()) * * This can be used to set the result of a successful lookup in ->atomic_open(). * * NB: unlike finish_open() this function does consume the dentry reference and * the caller need not dput() it. * * Returns "0" which must be the return value of ->atomic_open() after having * called this function. */ int finish_no_open(struct file *file, struct dentry *dentry) { file->f_path.dentry = dentry; return 0; } EXPORT_SYMBOL(finish_no_open); char *file_path(struct file *filp, char *buf, int buflen) { return d_path(&filp->f_path, buf, buflen); } EXPORT_SYMBOL(file_path); /** * vfs_open - open the file at the given path * @path: path to open * @file: newly allocated file with f_flag initialized * @cred: credentials to use */ int vfs_open(const struct path *path, struct file *file) { file->f_path = *path; return do_dentry_open(file, d_backing_inode(path->dentry), NULL); } struct file *dentry_open(const struct path *path, int flags, const struct cred *cred) { int error; struct file *f; validate_creds(cred); /* We must always pass in a valid mount pointer. */ BUG_ON(!path->mnt); f = alloc_empty_file(flags, cred); if (!IS_ERR(f)) { error = vfs_open(path, f); if (error) { fput(f); f = ERR_PTR(error); } } return f; } EXPORT_SYMBOL(dentry_open); struct file *open_with_fake_path(const struct path *path, int flags, struct inode *inode, const struct cred *cred) { struct file *f = alloc_empty_file_noaccount(flags, cred); if (!IS_ERR(f)) { int error; f->f_path = *path; error = do_dentry_open(f, inode, NULL); if (error) { fput(f); f = ERR_PTR(error); } } return f; } EXPORT_SYMBOL(open_with_fake_path); #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE)) #define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC) inline struct open_how build_open_how(int flags, umode_t mode) { struct open_how how = { .flags = flags & VALID_OPEN_FLAGS, .mode = mode & S_IALLUGO, }; /* O_PATH beats everything else. */ if (how.flags & O_PATH) how.flags &= O_PATH_FLAGS; /* Modes should only be set for create-like flags. */ if (!WILL_CREATE(how.flags)) how.mode = 0; return how; } inline int build_open_flags(const struct open_how *how, struct open_flags *op) { u64 flags = how->flags; u64 strip = FMODE_NONOTIFY | O_CLOEXEC; int lookup_flags = 0; int acc_mode = ACC_MODE(flags); BUILD_BUG_ON_MSG(upper_32_bits(VALID_OPEN_FLAGS), "struct open_flags doesn't yet handle flags > 32 bits"); /* * Strip flags that either shouldn't be set by userspace like * FMODE_NONOTIFY or that aren't relevant in determining struct * open_flags like O_CLOEXEC. */ flags &= ~strip; /* * Older syscalls implicitly clear all of the invalid flags or argument * values before calling build_open_flags(), but openat2(2) checks all * of its arguments. */ if (flags & ~VALID_OPEN_FLAGS) return -EINVAL; if (how->resolve & ~VALID_RESOLVE_FLAGS) return -EINVAL; /* Scoping flags are mutually exclusive. */ if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT)) return -EINVAL; /* Deal with the mode. */ if (WILL_CREATE(flags)) { if (how->mode & ~S_IALLUGO) return -EINVAL; op->mode = how->mode | S_IFREG; } else { if (how->mode != 0) return -EINVAL; op->mode = 0; } /* * In order to ensure programs get explicit errors when trying to use * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we * have to require userspace to explicitly set it. */ if (flags & __O_TMPFILE) { if ((flags & O_TMPFILE_MASK) != O_TMPFILE) return -EINVAL; if (!(acc_mode & MAY_WRITE)) return -EINVAL; } if (flags & O_PATH) { /* O_PATH only permits certain other flags to be set. */ if (flags & ~O_PATH_FLAGS) return -EINVAL; acc_mode = 0; } /* * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only * check for O_DSYNC if the need any syncing at all we enforce it's * always set instead of having to deal with possibly weird behaviour * for malicious applications setting only __O_SYNC. */ if (flags & __O_SYNC) flags |= O_DSYNC; op->open_flag = flags; /* O_TRUNC implies we need access checks for write permissions */ if (flags & O_TRUNC) acc_mode |= MAY_WRITE; /* Allow the LSM permission hook to distinguish append access from general write access. */ if (flags & O_APPEND) acc_mode |= MAY_APPEND; op->acc_mode = acc_mode; op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; if (flags & O_CREAT) { op->intent |= LOOKUP_CREATE; if (flags & O_EXCL) { op->intent |= LOOKUP_EXCL; flags |= O_NOFOLLOW; } } if (flags & O_DIRECTORY) lookup_flags |= LOOKUP_DIRECTORY; if (!(flags & O_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; if (how->resolve & RESOLVE_NO_XDEV) lookup_flags |= LOOKUP_NO_XDEV; if (how->resolve & RESOLVE_NO_MAGICLINKS) lookup_flags |= LOOKUP_NO_MAGICLINKS; if (how->resolve & RESOLVE_NO_SYMLINKS) lookup_flags |= LOOKUP_NO_SYMLINKS; if (how->resolve & RESOLVE_BENEATH) lookup_flags |= LOOKUP_BENEATH; if (how->resolve & RESOLVE_IN_ROOT) lookup_flags |= LOOKUP_IN_ROOT; op->lookup_flags = lookup_flags; return 0; } /** * file_open_name - open file and return file pointer * * @name: struct filename containing path to open * @flags: open flags as per the open(2) second argument * @mode: mode for the new file if O_CREAT is set, else ignored * * This is the helper to open a file from kernelspace if you really * have to. But in generally you should not do this, so please move * along, nothing to see here.. */ struct file *file_open_name(struct filename *name, int flags, umode_t mode) { struct open_flags op; struct open_how how = build_open_how(flags, mode); int err = build_open_flags(&how, &op); if (err) return ERR_PTR(err); return do_filp_open(AT_FDCWD, name, &op); } /** * filp_open - open file and return file pointer * * @filename: path to open * @flags: open flags as per the open(2) second argument * @mode: mode for the new file if O_CREAT is set, else ignored * * This is the helper to open a file from kernelspace if you really * have to. But in generally you should not do this, so please move * along, nothing to see here.. */ struct file *filp_open(const char *filename, int flags, umode_t mode) { struct filename *name = getname_kernel(filename); struct file *file = ERR_CAST(name); if (!IS_ERR(name)) { file = file_open_name(name, flags, mode); putname(name); } return file; } EXPORT_SYMBOL(filp_open); struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, const char *filename, int flags, umode_t mode) { struct open_flags op; struct open_how how = build_open_how(flags, mode); int err = build_open_flags(&how, &op); if (err) return ERR_PTR(err); return do_file_open_root(dentry, mnt, filename, &op); } EXPORT_SYMBOL(file_open_root); static long do_sys_openat2(int dfd, const char __user *filename, struct open_how *how) { struct open_flags op; int fd = build_open_flags(how, &op); struct filename *tmp; if (fd) return fd; tmp = getname(filename); if (IS_ERR(tmp)) return PTR_ERR(tmp); fd = get_unused_fd_flags(how->flags); if (fd >= 0) { struct file *f = do_filp_open(dfd, tmp, &op); if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); } else { fsnotify_open(f); fd_install(fd, f); } } putname(tmp); return fd; } long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) { struct open_how how = build_open_how(flags, mode); return do_sys_openat2(dfd, filename, &how); } SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) { if (force_o_largefile()) flags |= O_LARGEFILE; return do_sys_open(AT_FDCWD, filename, flags, mode); } SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) { if (force_o_largefile()) flags |= O_LARGEFILE; return do_sys_open(dfd, filename, flags, mode); } SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename, struct open_how __user *, how, size_t, usize) { int err; struct open_how tmp; BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0); BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST); if (unlikely(usize < OPEN_HOW_SIZE_VER0)) return -EINVAL; err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize); if (err) return err; /* O_LARGEFILE is only allowed for non-O_PATH. */ if (!(tmp.flags & O_PATH) && force_o_largefile()) tmp.flags |= O_LARGEFILE; return do_sys_openat2(dfd, filename, &tmp); } #ifdef CONFIG_COMPAT /* * Exactly like sys_open(), except that it doesn't set the * O_LARGEFILE flag. */ COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) { return do_sys_open(AT_FDCWD, filename, flags, mode); } /* * Exactly like sys_openat(), except that it doesn't set the * O_LARGEFILE flag. */ COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) { return do_sys_open(dfd, filename, flags, mode); } #endif #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) { int flags = O_CREAT | O_WRONLY | O_TRUNC; if (force_o_largefile()) flags |= O_LARGEFILE; return do_sys_open(AT_FDCWD, pathname, flags, mode); } #endif /* * "id" is the POSIX thread ID. We use the * files pointer for this.. */ int filp_close(struct file *filp, fl_owner_t id) { int retval = 0; if (!file_count(filp)) { printk(KERN_ERR "VFS: Close: file count is 0\n"); return 0; } if (filp->f_op->flush) retval = filp->f_op->flush(filp, id); if (likely(!(filp->f_mode & FMODE_PATH))) { dnotify_flush(filp, id); locks_remove_posix(filp, id); } fput(filp); return retval; } EXPORT_SYMBOL(filp_close); /* * Careful here! We test whether the file pointer is NULL before * releasing the fd. This ensures that one clone task can't release * an fd while another clone is opening it. */ SYSCALL_DEFINE1(close, unsigned int, fd) { int retval = __close_fd(current->files, fd); /* can't restart close syscall because file table entry was cleared */ if (unlikely(retval == -ERESTARTSYS || retval == -ERESTARTNOINTR || retval == -ERESTARTNOHAND || retval == -ERESTART_RESTARTBLOCK)) retval = -EINTR; return retval; } /** * close_range() - Close all file descriptors in a given range. * * @fd: starting file descriptor to close * @max_fd: last file descriptor to close * @flags: reserved for future extensions * * This closes a range of file descriptors. All file descriptors * from @fd up to and including @max_fd are closed. * Currently, errors to close a given file descriptor are ignored. */ SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd, unsigned int, flags) { return __close_range(fd, max_fd, flags); } /* * This routine simulates a hangup on the tty, to arrange that users * are given clean terminals at login time. */ SYSCALL_DEFINE0(vhangup) { if (capable(CAP_SYS_TTY_CONFIG)) { tty_vhangup_self(); return 0; } return -EPERM; } /* * Called when an inode is about to be open. * We use this to disallow opening large files on 32bit systems if * the caller didn't specify O_LARGEFILE. On 64bit systems we force * on this flag in sys_open. */ int generic_file_open(struct inode * inode, struct file * filp) { if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) return -EOVERFLOW; return 0; } EXPORT_SYMBOL(generic_file_open); /* * This is used by subsystems that don't want seekable * file descriptors. The function is not supposed to ever fail, the only * reason it returns an 'int' and not 'void' is so that it can be plugged * directly into file_operations structure. */ int nonseekable_open(struct inode *inode, struct file *filp) { filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); return 0; } EXPORT_SYMBOL(nonseekable_open); /* * stream_open is used by subsystems that want stream-like file descriptors. * Such file descriptors are not seekable and don't have notion of position * (file.f_pos is always 0 and ppos passed to .read()/.write() is always NULL). * Contrary to file descriptors of other regular files, .read() and .write() * can run simultaneously. * * stream_open never fails and is marked to return int so that it could be * directly used as file_operations.open . */ int stream_open(struct inode *inode, struct file *filp) { filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS); filp->f_mode |= FMODE_STREAM; return 0; } EXPORT_SYMBOL(stream_open);
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 // SPDX-License-Identifier: GPL-2.0 /* * Functions related to io context handling */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/slab.h> #include <linux/sched/task.h> #include "blk.h" /* * For io context allocations */ static struct kmem_cache *iocontext_cachep; /** * get_io_context - increment reference count to io_context * @ioc: io_context to get * * Increment reference count to @ioc. */ void get_io_context(struct io_context *ioc) { BUG_ON(atomic_long_read(&ioc->refcount) <= 0); atomic_long_inc(&ioc->refcount); } static void icq_free_icq_rcu(struct rcu_head *head) { struct io_cq *icq = container_of(head, struct io_cq, __rcu_head); kmem_cache_free(icq->__rcu_icq_cache, icq); } /* * Exit an icq. Called with ioc locked for blk-mq, and with both ioc * and queue locked for legacy. */ static void ioc_exit_icq(struct io_cq *icq) { struct elevator_type *et = icq->q->elevator->type; if (icq->flags & ICQ_EXITED) return; if (et->ops.exit_icq) et->ops.exit_icq(icq); icq->flags |= ICQ_EXITED; } /* * Release an icq. Called with ioc locked for blk-mq, and with both ioc * and queue locked for legacy. */ static void ioc_destroy_icq(struct io_cq *icq) { struct io_context *ioc = icq->ioc; struct request_queue *q = icq->q; struct elevator_type *et = q->elevator->type; lockdep_assert_held(&ioc->lock); radix_tree_delete(&ioc->icq_tree, icq->q->id); hlist_del_init(&icq->ioc_node); list_del_init(&icq->q_node); /* * Both setting lookup hint to and clearing it from @icq are done * under queue_lock. If it's not pointing to @icq now, it never * will. Hint assignment itself can race safely. */ if (rcu_access_pointer(ioc->icq_hint) == icq) rcu_assign_pointer(ioc->icq_hint, NULL); ioc_exit_icq(icq); /* * @icq->q might have gone away by the time RCU callback runs * making it impossible to determine icq_cache. Record it in @icq. */ icq->__rcu_icq_cache = et->icq_cache; icq->flags |= ICQ_DESTROYED; call_rcu(&icq->__rcu_head, icq_free_icq_rcu); } /* * Slow path for ioc release in put_io_context(). Performs double-lock * dancing to unlink all icq's and then frees ioc. */ static void ioc_release_fn(struct work_struct *work) { struct io_context *ioc = container_of(work, struct io_context, release_work); spin_lock_irq(&ioc->lock); while (!hlist_empty(&ioc->icq_list)) { struct io_cq *icq = hlist_entry(ioc->icq_list.first, struct io_cq, ioc_node); struct request_queue *q = icq->q; if (spin_trylock(&q->queue_lock)) { ioc_destroy_icq(icq); spin_unlock(&q->queue_lock); } else { /* Make sure q and icq cannot be freed. */ rcu_read_lock(); /* Re-acquire the locks in the correct order. */ spin_unlock(&ioc->lock); spin_lock(&q->queue_lock); spin_lock(&ioc->lock); /* * The icq may have been destroyed when the ioc lock * was released. */ if (!(icq->flags & ICQ_DESTROYED)) ioc_destroy_icq(icq); spin_unlock(&q->queue_lock); rcu_read_unlock(); } } spin_unlock_irq(&ioc->lock); kmem_cache_free(iocontext_cachep, ioc); } /** * put_io_context - put a reference of io_context * @ioc: io_context to put * * Decrement reference count of @ioc and release it if the count reaches * zero. */ void put_io_context(struct io_context *ioc) { unsigned long flags; bool free_ioc = false; if (ioc == NULL) return; BUG_ON(atomic_long_read(&ioc->refcount) <= 0); /* * Releasing ioc requires reverse order double locking and we may * already be holding a queue_lock. Do it asynchronously from wq. */ if (atomic_long_dec_and_test(&ioc->refcount)) { spin_lock_irqsave(&ioc->lock, flags); if (!hlist_empty(&ioc->icq_list)) queue_work(system_power_efficient_wq, &ioc->release_work); else free_ioc = true; spin_unlock_irqrestore(&ioc->lock, flags); } if (free_ioc) kmem_cache_free(iocontext_cachep, ioc); } /** * put_io_context_active - put active reference on ioc * @ioc: ioc of interest * * Undo get_io_context_active(). If active reference reaches zero after * put, @ioc can never issue further IOs and ioscheds are notified. */ void put_io_context_active(struct io_context *ioc) { struct io_cq *icq; if (!atomic_dec_and_test(&ioc->active_ref)) { put_io_context(ioc); return; } spin_lock_irq(&ioc->lock); hlist_for_each_entry(icq, &ioc->icq_list, ioc_node) { if (icq->flags & ICQ_EXITED) continue; ioc_exit_icq(icq); } spin_unlock_irq(&ioc->lock); put_io_context(ioc); } /* Called by the exiting task */ void exit_io_context(struct task_struct *task) { struct io_context *ioc; task_lock(task); ioc = task->io_context; task->io_context = NULL; task_unlock(task); atomic_dec(&ioc->nr_tasks); put_io_context_active(ioc); } static void __ioc_clear_queue(struct list_head *icq_list) { unsigned long flags; rcu_read_lock(); while (!list_empty(icq_list)) { struct io_cq *icq = list_entry(icq_list->next, struct io_cq, q_node); struct io_context *ioc = icq->ioc; spin_lock_irqsave(&ioc->lock, flags); if (icq->flags & ICQ_DESTROYED) { spin_unlock_irqrestore(&ioc->lock, flags); continue; } ioc_destroy_icq(icq); spin_unlock_irqrestore(&ioc->lock, flags); } rcu_read_unlock(); } /** * ioc_clear_queue - break any ioc association with the specified queue * @q: request_queue being cleared * * Walk @q->icq_list and exit all io_cq's. */ void ioc_clear_queue(struct request_queue *q) { LIST_HEAD(icq_list); spin_lock_irq(&q->queue_lock); list_splice_init(&q->icq_list, &icq_list); spin_unlock_irq(&q->queue_lock); __ioc_clear_queue(&icq_list); } int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node) { struct io_context *ioc; int ret; ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO, node); if (unlikely(!ioc)) return -ENOMEM; /* initialize */ atomic_long_set(&ioc->refcount, 1); atomic_set(&ioc->nr_tasks, 1); atomic_set(&ioc->active_ref, 1); spin_lock_init(&ioc->lock); INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC); INIT_HLIST_HEAD(&ioc->icq_list); INIT_WORK(&ioc->release_work, ioc_release_fn); /* * Try to install. ioc shouldn't be installed if someone else * already did or @task, which isn't %current, is exiting. Note * that we need to allow ioc creation on exiting %current as exit * path may issue IOs from e.g. exit_files(). The exit path is * responsible for not issuing IO after exit_io_context(). */ task_lock(task); if (!task->io_context && (task == current || !(task->flags & PF_EXITING))) task->io_context = ioc; else kmem_cache_free(iocontext_cachep, ioc); ret = task->io_context ? 0 : -EBUSY; task_unlock(task); return ret; } /** * get_task_io_context - get io_context of a task * @task: task of interest * @gfp_flags: allocation flags, used if allocation is necessary * @node: allocation node, used if allocation is necessary * * Return io_context of @task. If it doesn't exist, it is created with * @gfp_flags and @node. The returned io_context has its reference count * incremented. * * This function always goes through task_lock() and it's better to use * %current->io_context + get_io_context() for %current. */ struct io_context *get_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node) { struct io_context *ioc; might_sleep_if(gfpflags_allow_blocking(gfp_flags)); do { task_lock(task); ioc = task->io_context; if (likely(ioc)) { get_io_context(ioc); task_unlock(task); return ioc; } task_unlock(task); } while (!create_task_io_context(task, gfp_flags, node)); return NULL; } /** * ioc_lookup_icq - lookup io_cq from ioc * @ioc: the associated io_context * @q: the associated request_queue * * Look up io_cq associated with @ioc - @q pair from @ioc. Must be called * with @q->queue_lock held. */ struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q) { struct io_cq *icq; lockdep_assert_held(&q->queue_lock); /* * icq's are indexed from @ioc using radix tree and hint pointer, * both of which are protected with RCU. All removals are done * holding both q and ioc locks, and we're holding q lock - if we * find a icq which points to us, it's guaranteed to be valid. */ rcu_read_lock(); icq = rcu_dereference(ioc->icq_hint); if (icq && icq->q == q) goto out; icq = radix_tree_lookup(&ioc->icq_tree, q->id); if (icq && icq->q == q) rcu_assign_pointer(ioc->icq_hint, icq); /* allowed to race */ else icq = NULL; out: rcu_read_unlock(); return icq; } EXPORT_SYMBOL(ioc_lookup_icq); /** * ioc_create_icq - create and link io_cq * @ioc: io_context of interest * @q: request_queue of interest * @gfp_mask: allocation mask * * Make sure io_cq linking @ioc and @q exists. If icq doesn't exist, they * will be created using @gfp_mask. * * The caller is responsible for ensuring @ioc won't go away and @q is * alive and will stay alive until this function returns. */ struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, gfp_t gfp_mask) { struct elevator_type *et = q->elevator->type; struct io_cq *icq; /* allocate stuff */ icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO, q->node); if (!icq) return NULL; if (radix_tree_maybe_preload(gfp_mask) < 0) { kmem_cache_free(et->icq_cache, icq); return NULL; } icq->ioc = ioc; icq->q = q; INIT_LIST_HEAD(&icq->q_node); INIT_HLIST_NODE(&icq->ioc_node); /* lock both q and ioc and try to link @icq */ spin_lock_irq(&q->queue_lock); spin_lock(&ioc->lock); if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) { hlist_add_head(&icq->ioc_node, &ioc->icq_list); list_add(&icq->q_node, &q->icq_list); if (et->ops.init_icq) et->ops.init_icq(icq); } else { kmem_cache_free(et->icq_cache, icq); icq = ioc_lookup_icq(ioc, q); if (!icq) printk(KERN_ERR "cfq: icq link failed!\n"); } spin_unlock(&ioc->lock); spin_unlock_irq(&q->queue_lock); radix_tree_preload_end(); return icq; } static int __init blk_ioc_init(void) { iocontext_cachep = kmem_cache_create("blkdev_ioc", sizeof(struct io_context), 0, SLAB_PANIC, NULL); return 0; } subsys_initcall(blk_ioc_init);
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 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _DELAYED_CALL_H #define _DELAYED_CALL_H /* * Poor man's closures; I wish we could've done them sanely polymorphic, * but... */ struct delayed_call { void (*fn)(void *); void *arg; }; #define DEFINE_DELAYED_CALL(name) struct delayed_call name = {NULL, NULL} /* I really wish we had closures with sane typechecking... */ static inline void set_delayed_call(struct delayed_call *call, void (*fn)(void *), void *arg) { call->fn = fn; call->arg = arg; } static inline void do_delayed_call(struct delayed_call *call) { if (call->fn) call->fn(call->arg); } static inline void clear_delayed_call(struct delayed_call *call) { call->fn = NULL; } #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 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_LOCAL_H #define _ASM_X86_LOCAL_H #include <linux/percpu.h> #include <linux/atomic.h> #include <asm/asm.h> typedef struct { atomic_long_t a; } local_t; #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } #define local_read(l) atomic_long_read(&(l)->a) #define local_set(l, i) atomic_long_set(&(l)->a, (i)) static inline void local_inc(local_t *l) { asm volatile(_ASM_INC "%0" : "+m" (l->a.counter)); } static inline void local_dec(local_t *l) { asm volatile(_ASM_DEC "%0" : "+m" (l->a.counter)); } static inline void local_add(long i, local_t *l) { asm volatile(_ASM_ADD "%1,%0" : "+m" (l->a.counter) : "ir" (i)); } static inline void local_sub(long i, local_t *l) { asm volatile(_ASM_SUB "%1,%0" : "+m" (l->a.counter) : "ir" (i)); } /** * local_sub_and_test - subtract value from variable and test result * @i: integer value to subtract * @l: pointer to type local_t * * Atomically subtracts @i from @l and returns * true if the result is zero, or false for all * other cases. */ static inline bool local_sub_and_test(long i, local_t *l) { return GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, e, "er", i); } /** * local_dec_and_test - decrement and test * @l: pointer to type local_t * * Atomically decrements @l by 1 and * returns true if the result is 0, or false for all other * cases. */ static inline bool local_dec_and_test(local_t *l) { return GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, e); } /** * local_inc_and_test - increment and test * @l: pointer to type local_t * * Atomically increments @l by 1 * and returns true if the result is zero, or false for all * other cases. */ static inline bool local_inc_and_test(local_t *l) { return GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, e); } /** * local_add_negative - add and test if negative * @i: integer value to add * @l: pointer to type local_t * * Atomically adds @i to @l and returns true * if the result is negative, or false when * result is greater than or equal to zero. */ static inline bool local_add_negative(long i, local_t *l) { return GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, s, "er", i); } /** * local_add_return - add and return * @i: integer value to add * @l: pointer to type local_t * * Atomically adds @i to @l and returns @i + @l */ static inline long local_add_return(long i, local_t *l) { long __i = i; asm volatile(_ASM_XADD "%0, %1;" : "+r" (i), "+m" (l->a.counter) : : "memory"); return i + __i; } static inline long local_sub_return(long i, local_t *l) { return local_add_return(-i, l); } #define local_inc_return(l) (local_add_return(1, l)) #define local_dec_return(l) (local_sub_return(1, l)) #define local_cmpxchg(l, o, n) \ (cmpxchg_local(&((l)->a.counter), (o), (n))) /* Always has a lock prefix */ #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) /** * local_add_unless - add unless the number is a given value * @l: pointer of type local_t * @a: the amount to add to l... * @u: ...unless l is equal to u. * * Atomically adds @a to @l, so long as it was not @u. * Returns non-zero if @l was not @u, and zero otherwise. */ #define local_add_unless(l, a, u) \ ({ \ long c, old; \ c = local_read((l)); \ for (;;) { \ if (unlikely(c == (u))) \ break; \ old = local_cmpxchg((l), c, c + (a)); \ if (likely(old == c)) \ break; \ c = old; \ } \ c != (u); \ }) #define local_inc_not_zero(l) local_add_unless((l), 1, 0) /* On x86_32, these are no better than the atomic variants. * On x86-64 these are better than the atomic variants on SMP kernels * because they dont use a lock prefix. */ #define __local_inc(l) local_inc(l) #define __local_dec(l) local_dec(l) #define __local_add(i, l) local_add((i), (l)) #define __local_sub(i, l) local_sub((i), (l)) #endif /* _ASM_X86_LOCAL_H */
1 1 1 1 1 1 1 1 1 1 1 1 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 // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2016 Facebook * Copyright (C) 2013-2014 Jens Axboe */ #include <linux/sched.h> #include <linux/random.h> #include <linux/sbitmap.h> #include <linux/seq_file.h> /* * See if we have deferred clears that we can batch move */ static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index) { unsigned long mask, val; bool ret = false; unsigned long flags; spin_lock_irqsave(&sb->map[index].swap_lock, flags); if (!sb->map[index].cleared) goto out_unlock; /* * First get a stable cleared mask, setting the old mask to 0. */ mask = xchg(&sb->map[index].cleared, 0); /* * Now clear the masked bits in our free word */ do { val = sb->map[index].word; } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val); ret = true; out_unlock: spin_unlock_irqrestore(&sb->map[index].swap_lock, flags); return ret; } int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, gfp_t flags, int node) { unsigned int bits_per_word; unsigned int i; if (shift < 0) { shift = ilog2(BITS_PER_LONG); /* * If the bitmap is small, shrink the number of bits per word so * we spread over a few cachelines, at least. If less than 4 * bits, just forget about it, it's not going to work optimally * anyway. */ if (depth >= 4) { while ((4U << shift) > depth) shift--; } } bits_per_word = 1U << shift; if (bits_per_word > BITS_PER_LONG) return -EINVAL; sb->shift = shift; sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); if (depth == 0) { sb->map = NULL; return 0; } sb->map = kcalloc_node(sb->map_nr, sizeof(*sb->map), flags, node); if (!sb->map) return -ENOMEM; for (i = 0; i < sb->map_nr; i++) { sb->map[i].depth = min(depth, bits_per_word); depth -= sb->map[i].depth; spin_lock_init(&sb->map[i].swap_lock); } return 0; } EXPORT_SYMBOL_GPL(sbitmap_init_node); void sbitmap_resize(struct sbitmap *sb, unsigned int depth) { unsigned int bits_per_word = 1U << sb->shift; unsigned int i; for (i = 0; i < sb->map_nr; i++) sbitmap_deferred_clear(sb, i); sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); for (i = 0; i < sb->map_nr; i++) { sb->map[i].depth = min(depth, bits_per_word); depth -= sb->map[i].depth; } } EXPORT_SYMBOL_GPL(sbitmap_resize); static int __sbitmap_get_word(unsigned long *word, unsigned long depth, unsigned int hint, bool wrap) { unsigned int orig_hint = hint; int nr; while (1) { nr = find_next_zero_bit(word, depth, hint); if (unlikely(nr >= depth)) { /* * We started with an offset, and we didn't reset the * offset to 0 in a failure case, so start from 0 to * exhaust the map. */ if (orig_hint && hint && wrap) { hint = orig_hint = 0; continue; } return -1; } if (!test_and_set_bit_lock(nr, word)) break; hint = nr + 1; if (hint >= depth - 1) hint = 0; } return nr; } static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, unsigned int alloc_hint, bool round_robin) { int nr; do { nr = __sbitmap_get_word(&sb->map[index].word, sb->map[index].depth, alloc_hint, !round_robin); if (nr != -1) break; if (!sbitmap_deferred_clear(sb, index)) break; } while (1); return nr; } int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin) { unsigned int i, index; int nr = -1; index = SB_NR_TO_INDEX(sb, alloc_hint); /* * Unless we're doing round robin tag allocation, just use the * alloc_hint to find the right word index. No point in looping * twice in find_next_zero_bit() for that case. */ if (round_robin) alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); else alloc_hint = 0; for (i = 0; i < sb->map_nr; i++) { nr = sbitmap_find_bit_in_index(sb, index, alloc_hint, round_robin); if (nr != -1) { nr += index << sb->shift; break; } /* Jump to next index. */ alloc_hint = 0; if (++index >= sb->map_nr) index = 0; } return nr; } EXPORT_SYMBOL_GPL(sbitmap_get); int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, unsigned long shallow_depth) { unsigned int i, index; int nr = -1; index = SB_NR_TO_INDEX(sb, alloc_hint); for (i = 0; i < sb->map_nr; i++) { again: nr = __sbitmap_get_word(&sb->map[index].word, min(sb->map[index].depth, shallow_depth), SB_NR_TO_BIT(sb, alloc_hint), true); if (nr != -1) { nr += index << sb->shift; break; } if (sbitmap_deferred_clear(sb, index)) goto again; /* Jump to next index. */ index++; alloc_hint = index << sb->shift; if (index >= sb->map_nr) { index = 0; alloc_hint = 0; } } return nr; } EXPORT_SYMBOL_GPL(sbitmap_get_shallow); bool sbitmap_any_bit_set(const struct sbitmap *sb) { unsigned int i; for (i = 0; i < sb->map_nr; i++) { if (sb->map[i].word & ~sb->map[i].cleared) return true; } return false; } EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) { unsigned int i, weight = 0; for (i = 0; i < sb->map_nr; i++) { const struct sbitmap_word *word = &sb->map[i]; if (set) weight += bitmap_weight(&word->word, word->depth); else weight += bitmap_weight(&word->cleared, word->depth); } return weight; } static unsigned int sbitmap_weight(const struct sbitmap *sb) { return __sbitmap_weight(sb, true); } static unsigned int sbitmap_cleared(const struct sbitmap *sb) { return __sbitmap_weight(sb, false); } void sbitmap_show(struct sbitmap *sb, struct seq_file *m) { seq_printf(m, "depth=%u\n", sb->depth); seq_printf(m, "busy=%u\n", sbitmap_weight(sb) - sbitmap_cleared(sb)); seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb)); seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); seq_printf(m, "map_nr=%u\n", sb->map_nr); } EXPORT_SYMBOL_GPL(sbitmap_show); static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) { if ((offset & 0xf) == 0) { if (offset != 0) seq_putc(m, '\n'); seq_printf(m, "%08x:", offset); } if ((offset & 0x1) == 0) seq_putc(m, ' '); seq_printf(m, "%02x", byte); } void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) { u8 byte = 0; unsigned int byte_bits = 0; unsigned int offset = 0; int i; for (i = 0; i < sb->map_nr; i++) { unsigned long word = READ_ONCE(sb->map[i].word); unsigned long cleared = READ_ONCE(sb->map[i].cleared); unsigned int word_bits = READ_ONCE(sb->map[i].depth); word &= ~cleared; while (word_bits > 0) { unsigned int bits = min(8 - byte_bits, word_bits); byte |= (word & (BIT(bits) - 1)) << byte_bits; byte_bits += bits; if (byte_bits == 8) { emit_byte(m, offset, byte); byte = 0; byte_bits = 0; offset++; } word >>= bits; word_bits -= bits; } } if (byte_bits) { emit_byte(m, offset, byte); offset++; } if (offset) seq_putc(m, '\n'); } EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, unsigned int depth) { unsigned int wake_batch; unsigned int shallow_depth; /* * For each batch, we wake up one queue. We need to make sure that our * batch size is small enough that the full depth of the bitmap, * potentially limited by a shallow depth, is enough to wake up all of * the queues. * * Each full word of the bitmap has bits_per_word bits, and there might * be a partial word. There are depth / bits_per_word full words and * depth % bits_per_word bits left over. In bitwise arithmetic: * * bits_per_word = 1 << shift * depth / bits_per_word = depth >> shift * depth % bits_per_word = depth & ((1 << shift) - 1) * * Each word can be limited to sbq->min_shallow_depth bits. */ shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth); depth = ((depth >> sbq->sb.shift) * shallow_depth + min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth)); wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1, SBQ_WAKE_BATCH); return wake_batch; } int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, int shift, bool round_robin, gfp_t flags, int node) { int ret; int i; ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node); if (ret) return ret; sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); if (!sbq->alloc_hint) { sbitmap_free(&sbq->sb); return -ENOMEM; } if (depth && !round_robin) { for_each_possible_cpu(i) *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; } sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); atomic_set(&sbq->ws_active, 0); sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { free_percpu(sbq->alloc_hint); sbitmap_free(&sbq->sb); return -ENOMEM; } for (i = 0; i < SBQ_WAIT_QUEUES; i++) { init_waitqueue_head(&sbq->ws[i].wait); atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch); } sbq->round_robin = round_robin; return 0; } EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, unsigned int depth) { unsigned int wake_batch = sbq_calc_wake_batch(sbq, depth); int i; if (sbq->wake_batch != wake_batch) { WRITE_ONCE(sbq->wake_batch, wake_batch); /* * Pairs with the memory barrier in sbitmap_queue_wake_up() * to ensure that the batch size is updated before the wait * counts. */ smp_mb(); for (i = 0; i < SBQ_WAIT_QUEUES; i++) atomic_set(&sbq->ws[i].wait_cnt, 1); } } void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) { sbitmap_queue_update_wake_batch(sbq, depth); sbitmap_resize(&sbq->sb, depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_resize); int __sbitmap_queue_get(struct sbitmap_queue *sbq) { unsigned int hint, depth; int nr; hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); if (unlikely(hint >= depth)) { hint = depth ? prandom_u32() % depth : 0; this_cpu_write(*sbq->alloc_hint, hint); } nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin); if (nr == -1) { /* If the map is full, a hint won't do us much good. */ this_cpu_write(*sbq->alloc_hint, 0); } else if (nr == hint || unlikely(sbq->round_robin)) { /* Only update the hint if we used it. */ hint = nr + 1; if (hint >= depth - 1) hint = 0; this_cpu_write(*sbq->alloc_hint, hint); } return nr; } EXPORT_SYMBOL_GPL(__sbitmap_queue_get); int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, unsigned int shallow_depth) { unsigned int hint, depth; int nr; WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); if (unlikely(hint >= depth)) { hint = depth ? prandom_u32() % depth : 0; this_cpu_write(*sbq->alloc_hint, hint); } nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth); if (nr == -1) { /* If the map is full, a hint won't do us much good. */ this_cpu_write(*sbq->alloc_hint, 0); } else if (nr == hint || unlikely(sbq->round_robin)) { /* Only update the hint if we used it. */ hint = nr + 1; if (hint >= depth - 1) hint = 0; this_cpu_write(*sbq->alloc_hint, hint); } return nr; } EXPORT_SYMBOL_GPL(__sbitmap_queue_get_shallow); void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq, unsigned int min_shallow_depth) { sbq->min_shallow_depth = min_shallow_depth; sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth); static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) { int i, wake_index; if (!atomic_read(&sbq->ws_active)) return NULL; wake_index = atomic_read(&sbq->wake_index); for (i = 0; i < SBQ_WAIT_QUEUES; i++) { struct sbq_wait_state *ws = &sbq->ws[wake_index]; if (waitqueue_active(&ws->wait)) { if (wake_index != atomic_read(&sbq->wake_index)) atomic_set(&sbq->wake_index, wake_index); return ws; } wake_index = sbq_index_inc(wake_index); } return NULL; } static bool __sbq_wake_up(struct sbitmap_queue *sbq) { struct sbq_wait_state *ws; unsigned int wake_batch; int wait_cnt; ws = sbq_wake_ptr(sbq); if (!ws) return false; wait_cnt = atomic_dec_return(&ws->wait_cnt); if (wait_cnt <= 0) { int ret; wake_batch = READ_ONCE(sbq->wake_batch); /* * Pairs with the memory barrier in sbitmap_queue_resize() to * ensure that we see the batch size update before the wait * count is reset. */ smp_mb__before_atomic(); /* * For concurrent callers of this, the one that failed the * atomic_cmpxhcg() race should call this function again * to wakeup a new batch on a different 'ws'. */ ret = atomic_cmpxchg(&ws->wait_cnt, wait_cnt, wake_batch); if (ret == wait_cnt) { sbq_index_atomic_inc(&sbq->wake_index); wake_up_nr(&ws->wait, wake_batch); return false; } return true; } return false; } void sbitmap_queue_wake_up(struct sbitmap_queue *sbq) { while (__sbq_wake_up(sbq)) ; } EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up); void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, unsigned int cpu) { /* * Once the clear bit is set, the bit may be allocated out. * * Orders READ/WRITE on the asssociated instance(such as request * of blk_mq) by this bit for avoiding race with re-allocation, * and its pair is the memory barrier implied in __sbitmap_get_word. * * One invariant is that the clear bit has to be zero when the bit * is in use. */ smp_mb__before_atomic(); sbitmap_deferred_clear_bit(&sbq->sb, nr); /* * Pairs with the memory barrier in set_current_state() to ensure the * proper ordering of clear_bit_unlock()/waitqueue_active() in the waker * and test_and_set_bit_lock()/prepare_to_wait()/finish_wait() in the * waiter. See the comment on waitqueue_active(). */ smp_mb__after_atomic(); sbitmap_queue_wake_up(sbq); if (likely(!sbq->round_robin && nr < sbq->sb.depth)) *per_cpu_ptr(sbq->alloc_hint, cpu) = nr; } EXPORT_SYMBOL_GPL(sbitmap_queue_clear); void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) { int i, wake_index; /* * Pairs with the memory barrier in set_current_state() like in * sbitmap_queue_wake_up(). */ smp_mb(); wake_index = atomic_read(&sbq->wake_index); for (i = 0; i < SBQ_WAIT_QUEUES; i++) { struct sbq_wait_state *ws = &sbq->ws[wake_index]; if (waitqueue_active(&ws->wait)) wake_up(&ws->wait); wake_index = sbq_index_inc(wake_index); } } EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all); void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) { bool first; int i; sbitmap_show(&sbq->sb, m); seq_puts(m, "alloc_hint={"); first = true; for_each_possible_cpu(i) { if (!first) seq_puts(m, ", "); first = false; seq_printf(m, "%u", *per_cpu_ptr(sbq->alloc_hint, i)); } seq_puts(m, "}\n"); seq_printf(m, "wake_batch=%u\n", sbq->wake_batch); seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index)); seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active)); seq_puts(m, "ws={\n"); for (i = 0; i < SBQ_WAIT_QUEUES; i++) { struct sbq_wait_state *ws = &sbq->ws[i]; seq_printf(m, "\t{.wait_cnt=%d, .wait=%s},\n", atomic_read(&ws->wait_cnt), waitqueue_active(&ws->wait) ? "active" : "inactive"); } seq_puts(m, "}\n"); seq_printf(m, "round_robin=%d\n", sbq->round_robin); seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_show); void sbitmap_add_wait_queue(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait) { if (!sbq_wait->sbq) { sbq_wait->sbq = sbq; atomic_inc(&sbq->ws_active); add_wait_queue(&ws->wait, &sbq_wait->wait); } } EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue); void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait) { list_del_init(&sbq_wait->wait.entry); if (sbq_wait->sbq) { atomic_dec(&sbq_wait->sbq->ws_active); sbq_wait->sbq = NULL; } } EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue); void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait, int state) { if (!sbq_wait->sbq) { atomic_inc(&sbq->ws_active); sbq_wait->sbq = sbq; } prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state); } EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait); void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait) { finish_wait(&ws->wait, &sbq_wait->wait); if (sbq_wait->sbq) { atomic_dec(&sbq->ws_active); sbq_wait->sbq = NULL; } } EXPORT_SYMBOL_GPL(sbitmap_finish_wait);
1 2 2 2 2 2 2 2 2 2 2 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 // SPDX-License-Identifier: GPL-2.0-only /* * This implements the various checks for CONFIG_HARDENED_USERCOPY*, * which are designed to protect kernel memory from needless exposure * and overwrite under many unintended conditions. This code is based * on PAX_USERCOPY, which is: * * Copyright (C) 2001-2016 PaX Team, Bradley Spengler, Open Source * Security Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/mm.h> #include <linux/highmem.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/sched/task.h> #include <linux/sched/task_stack.h> #include <linux/thread_info.h> #include <linux/atomic.h> #include <linux/jump_label.h> #include <asm/sections.h> /* * Checks if a given pointer and length is contained by the current * stack frame (if possible). * * Returns: * NOT_STACK: not at all on the stack * GOOD_FRAME: fully within a valid stack frame * GOOD_STACK: fully on the stack (when can't do frame-checking) * BAD_STACK: error condition (invalid stack position or bad stack frame) */ static noinline int check_stack_object(const void *obj, unsigned long len) { const void * const stack = task_stack_page(current); const void * const stackend = stack + THREAD_SIZE; int ret; /* Object is not on the stack at all. */ if (obj + len <= stack || stackend <= obj) return NOT_STACK; /* * Reject: object partially overlaps the stack (passing the * check above means at least one end is within the stack, * so if this check fails, the other end is outside the stack). */ if (obj < stack || stackend < obj + len) return BAD_STACK; /* Check if object is safely within a valid frame. */ ret = arch_within_stack_frames(stack, stackend, obj, len); if (ret) return ret; return GOOD_STACK; } /* * If these functions are reached, then CONFIG_HARDENED_USERCOPY has found * an unexpected state during a copy_from_user() or copy_to_user() call. * There are several checks being performed on the buffer by the * __check_object_size() function. Normal stack buffer usage should never * trip the checks, and kernel text addressing will always trip the check. * For cache objects, it is checking that only the whitelisted range of * bytes for a given cache is being accessed (via the cache's usersize and * useroffset fields). To adjust a cache whitelist, use the usercopy-aware * kmem_cache_create_usercopy() function to create the cache (and * carefully audit the whitelist range). */ void usercopy_warn(const char *name, const char *detail, bool to_user, unsigned long offset, unsigned long len) { WARN_ONCE(1, "Bad or missing usercopy whitelist? Kernel memory %s attempt detected %s %s%s%s%s (offset %lu, size %lu)!\n", to_user ? "exposure" : "overwrite", to_user ? "from" : "to", name ? : "unknown?!", detail ? " '" : "", detail ? : "", detail ? "'" : "", offset, len); } void __noreturn usercopy_abort(const char *name, const char *detail, bool to_user, unsigned long offset, unsigned long len) { pr_emerg("Kernel memory %s attempt detected %s %s%s%s%s (offset %lu, size %lu)!\n", to_user ? "exposure" : "overwrite", to_user ? "from" : "to", name ? : "unknown?!", detail ? " '" : "", detail ? : "", detail ? "'" : "", offset, len); /* * For greater effect, it would be nice to do do_group_exit(), * but BUG() actually hooks all the lock-breaking and per-arch * Oops code, so that is used here instead. */ BUG(); } /* Returns true if any portion of [ptr,ptr+n) over laps with [low,high). */ static bool overlaps(const unsigned long ptr, unsigned long n, unsigned long low, unsigned long high) { const unsigned long check_low = ptr; unsigned long check_high = check_low + n; /* Does not overlap if entirely above or entirely below. */ if (check_low >= high || check_high <= low) return false; return true; } /* Is this address range in the kernel text area? */ static inline void check_kernel_text_object(const unsigned long ptr, unsigned long n, bool to_user) { unsigned long textlow = (unsigned long)_stext; unsigned long texthigh = (unsigned long)_etext; unsigned long textlow_linear, texthigh_linear; if (overlaps(ptr, n, textlow, texthigh)) usercopy_abort("kernel text", NULL, to_user, ptr - textlow, n); /* * Some architectures have virtual memory mappings with a secondary * mapping of the kernel text, i.e. there is more than one virtual * kernel address that points to the kernel image. It is usually * when there is a separate linear physical memory mapping, in that * __pa() is not just the reverse of __va(). This can be detected * and checked: */ textlow_linear = (unsigned long)lm_alias(textlow); /* No different mapping: we're done. */ if (textlow_linear == textlow) return; /* Check the secondary mapping... */ texthigh_linear = (unsigned long)lm_alias(texthigh); if (overlaps(ptr, n, textlow_linear, texthigh_linear)) usercopy_abort("linear kernel text", NULL, to_user, ptr - textlow_linear, n); } static inline void check_bogus_address(const unsigned long ptr, unsigned long n, bool to_user) { /* Reject if object wraps past end of memory. */ if (ptr + (n - 1) < ptr) usercopy_abort("wrapped address", NULL, to_user, 0, ptr + n); /* Reject if NULL or ZERO-allocation. */ if (ZERO_OR_NULL_PTR(ptr)) usercopy_abort("null address", NULL, to_user, ptr, n); } /* Checks for allocs that are marked in some way as spanning multiple pages. */ static inline void check_page_span(const void *ptr, unsigned long n, struct page *page, bool to_user) { #ifdef CONFIG_HARDENED_USERCOPY_PAGESPAN const void *end = ptr + n - 1; struct page *endpage; bool is_reserved, is_cma; /* * Sometimes the kernel data regions are not marked Reserved (see * check below). And sometimes [_sdata,_edata) does not cover * rodata and/or bss, so check each range explicitly. */ /* Allow reads of kernel rodata region (if not marked as Reserved). */ if (ptr >= (const void *)__start_rodata && end <= (const void *)__end_rodata) { if (!to_user) usercopy_abort("rodata", NULL, to_user, 0, n); return; } /* Allow kernel data region (if not marked as Reserved). */ if (ptr >= (const void *)_sdata && end <= (const void *)_edata) return; /* Allow kernel bss region (if not marked as Reserved). */ if (ptr >= (const void *)__bss_start && end <= (const void *)__bss_stop) return; /* Is the object wholly within one base page? */ if (likely(((unsigned long)ptr & (unsigned long)PAGE_MASK) == ((unsigned long)end & (unsigned long)PAGE_MASK))) return; /* Allow if fully inside the same compound (__GFP_COMP) page. */ endpage = virt_to_head_page(end); if (likely(endpage == page)) return; /* * Reject if range is entirely either Reserved (i.e. special or * device memory), or CMA. Otherwise, reject since the object spans * several independently allocated pages. */ is_reserved = PageReserved(page); is_cma = is_migrate_cma_page(page); if (!is_reserved && !is_cma) usercopy_abort("spans multiple pages", NULL, to_user, 0, n); for (ptr += PAGE_SIZE; ptr <= end; ptr += PAGE_SIZE) { page = virt_to_head_page(ptr); if (is_reserved && !PageReserved(page)) usercopy_abort("spans Reserved and non-Reserved pages", NULL, to_user, 0, n); if (is_cma && !is_migrate_cma_page(page)) usercopy_abort("spans CMA and non-CMA pages", NULL, to_user, 0, n); } #endif } static inline void check_heap_object(const void *ptr, unsigned long n, bool to_user) { struct page *page; if (!virt_addr_valid(ptr)) return; /* * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the * highmem page or fallback to virt_to_page(). The following * is effectively a highmem-aware virt_to_head_page(). */ page = compound_head(kmap_to_page((void *)ptr)); if (PageSlab(page)) { /* Check slab allocator for flags and size. */ __check_heap_object(ptr, n, page, to_user); } else { /* Verify object does not incorrectly span multiple pages. */ check_page_span(ptr, n, page, to_user); } } static DEFINE_STATIC_KEY_FALSE_RO(bypass_usercopy_checks); /* * Validates that the given object is: * - not bogus address * - fully contained by stack (or stack frame, when available) * - fully within SLAB object (or object whitelist area, when available) * - not in kernel text */ void __check_object_size(const void *ptr, unsigned long n, bool to_user) { if (static_branch_unlikely(&bypass_usercopy_checks)) return; /* Skip all tests if size is zero. */ if (!n) return; /* Check for invalid addresses. */ check_bogus_address((const unsigned long)ptr, n, to_user); /* Check for bad stack object. */ switch (check_stack_object(ptr, n)) { case NOT_STACK: /* Object is not touching the current process stack. */ break; case GOOD_FRAME: case GOOD_STACK: /* * Object is either in the correct frame (when it * is possible to check) or just generally on the * process stack (when frame checking not available). */ return; default: usercopy_abort("process stack", NULL, to_user, 0, n); } /* Check for bad heap object. */ check_heap_object(ptr, n, to_user); /* Check for object in kernel to avoid text exposure. */ check_kernel_text_object((const unsigned long)ptr, n, to_user); } EXPORT_SYMBOL(__check_object_size); static bool enable_checks __initdata = true; static int __init parse_hardened_usercopy(char *str) { return strtobool(str, &enable_checks); } __setup("hardened_usercopy=", parse_hardened_usercopy); static int __init set_hardened_usercopy(void) { if (enable_checks == false) static_branch_enable(&bypass_usercopy_checks); return 1; } late_initcall(set_hardened_usercopy);
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 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 // SPDX-License-Identifier: GPL-2.0-or-later /* Provide a way to create a superblock configuration context within the kernel * that allows a superblock to be set up prior to mounting. * * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/fs_context.h> #include <linux/fs_parser.h> #include <linux/fs.h> #include <linux/mount.h> #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/magic.h> #include <linux/security.h> #include <linux/mnt_namespace.h> #include <linux/pid_namespace.h> #include <linux/user_namespace.h> #include <net/net_namespace.h> #include <asm/sections.h> #include "mount.h" #include "internal.h" enum legacy_fs_param { LEGACY_FS_UNSET_PARAMS, LEGACY_FS_MONOLITHIC_PARAMS, LEGACY_FS_INDIVIDUAL_PARAMS, }; struct legacy_fs_context { char *legacy_data; /* Data page for legacy filesystems */ size_t data_size; enum legacy_fs_param param_type; }; static int legacy_init_fs_context(struct fs_context *fc); static const struct constant_table common_set_sb_flag[] = { { "dirsync", SB_DIRSYNC }, { "lazytime", SB_LAZYTIME }, { "mand", SB_MANDLOCK }, { "ro", SB_RDONLY }, { "sync", SB_SYNCHRONOUS }, { }, }; static const struct constant_table common_clear_sb_flag[] = { { "async", SB_SYNCHRONOUS }, { "nolazytime", SB_LAZYTIME }, { "nomand", SB_MANDLOCK }, { "rw", SB_RDONLY }, { }, }; /* * Check for a common mount option that manipulates s_flags. */ static int vfs_parse_sb_flag(struct fs_context *fc, const char *key) { unsigned int token; token = lookup_constant(common_set_sb_flag, key, 0); if (token) { fc->sb_flags |= token; fc->sb_flags_mask |= token; return 0; } token = lookup_constant(common_clear_sb_flag, key, 0); if (token) { fc->sb_flags &= ~token; fc->sb_flags_mask |= token; return 0; } return -ENOPARAM; } /** * vfs_parse_fs_param - Add a single parameter to a superblock config * @fc: The filesystem context to modify * @param: The parameter * * A single mount option in string form is applied to the filesystem context * being set up. Certain standard options (for example "ro") are translated * into flag bits without going to the filesystem. The active security module * is allowed to observe and poach options. Any other options are passed over * to the filesystem to parse. * * This may be called multiple times for a context. * * Returns 0 on success and a negative error code on failure. In the event of * failure, supplementary error information may have been set. */ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param) { int ret; if (!param->key) return invalf(fc, "Unnamed parameter\n"); ret = vfs_parse_sb_flag(fc, param->key); if (ret != -ENOPARAM) return ret; ret = security_fs_context_parse_param(fc, param); if (ret != -ENOPARAM) /* Param belongs to the LSM or is disallowed by the LSM; so * don't pass to the FS. */ return ret; if (fc->ops->parse_param) { ret = fc->ops->parse_param(fc, param); if (ret != -ENOPARAM) return ret; } /* If the filesystem doesn't take any arguments, give it the * default handling of source. */ if (strcmp(param->key, "source") == 0) { if (param->type != fs_value_is_string) return invalf(fc, "VFS: Non-string source"); if (fc->source) return invalf(fc, "VFS: Multiple sources"); fc->source = param->string; param->string = NULL; return 0; } return invalf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name, param->key); } EXPORT_SYMBOL(vfs_parse_fs_param); /** * vfs_parse_fs_string - Convenience function to just parse a string. */ int vfs_parse_fs_string(struct fs_context *fc, const char *key, const char *value, size_t v_size) { int ret; struct fs_parameter param = { .key = key, .type = fs_value_is_flag, .size = v_size, }; if (value) { param.string = kmemdup_nul(value, v_size, GFP_KERNEL); if (!param.string) return -ENOMEM; param.type = fs_value_is_string; } ret = vfs_parse_fs_param(fc, &param); kfree(param.string); return ret; } EXPORT_SYMBOL(vfs_parse_fs_string); /** * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data * @ctx: The superblock configuration to fill in. * @data: The data to parse * * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be * called from the ->monolithic_mount_data() fs_context operation. * * Returns 0 on success or the error returned by the ->parse_option() fs_context * operation on failure. */ int generic_parse_monolithic(struct fs_context *fc, void *data) { char *options = data, *key; int ret = 0; if (!options) return 0; ret = security_sb_eat_lsm_opts(options, &fc->security); if (ret) return ret; while ((key = strsep(&options, ",")) != NULL) { if (*key) { size_t v_len = 0; char *value = strchr(key, '='); if (value) { if (value == key) continue; *value++ = 0; v_len = strlen(value); } ret = vfs_parse_fs_string(fc, key, value, v_len); if (ret < 0) break; } } return ret; } EXPORT_SYMBOL(generic_parse_monolithic); /** * alloc_fs_context - Create a filesystem context. * @fs_type: The filesystem type. * @reference: The dentry from which this one derives (or NULL) * @sb_flags: Filesystem/superblock flags (SB_*) * @sb_flags_mask: Applicable members of @sb_flags * @purpose: The purpose that this configuration shall be used for. * * Open a filesystem and create a mount context. The mount context is * initialised with the supplied flags and, if a submount/automount from * another superblock (referred to by @reference) is supplied, may have * parameters such as namespaces copied across from that superblock. */ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type, struct dentry *reference, unsigned int sb_flags, unsigned int sb_flags_mask, enum fs_context_purpose purpose) { int (*init_fs_context)(struct fs_context *); struct fs_context *fc; int ret = -ENOMEM; fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL); if (!fc) return ERR_PTR(-ENOMEM); fc->purpose = purpose; fc->sb_flags = sb_flags; fc->sb_flags_mask = sb_flags_mask; fc->fs_type = get_filesystem(fs_type); fc->cred = get_current_cred(); fc->net_ns = get_net(current->nsproxy->net_ns); fc->log.prefix = fs_type->name; mutex_init(&fc->uapi_mutex); switch (purpose) { case FS_CONTEXT_FOR_MOUNT: fc->user_ns = get_user_ns(fc->cred->user_ns); break; case FS_CONTEXT_FOR_SUBMOUNT: fc->user_ns = get_user_ns(reference->d_sb->s_user_ns); break; case FS_CONTEXT_FOR_RECONFIGURE: atomic_inc(&reference->d_sb->s_active); fc->user_ns = get_user_ns(reference->d_sb->s_user_ns); fc->root = dget(reference); break; } /* TODO: Make all filesystems support this unconditionally */ init_fs_context = fc->fs_type->init_fs_context; if (!init_fs_context) init_fs_context = legacy_init_fs_context; ret = init_fs_context(fc); if (ret < 0) goto err_fc; fc->need_free = true; return fc; err_fc: put_fs_context(fc); return ERR_PTR(ret); } struct fs_context *fs_context_for_mount(struct file_system_type *fs_type, unsigned int sb_flags) { return alloc_fs_context(fs_type, NULL, sb_flags, 0, FS_CONTEXT_FOR_MOUNT); } EXPORT_SYMBOL(fs_context_for_mount); struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, unsigned int sb_flags, unsigned int sb_flags_mask) { return alloc_fs_context(dentry->d_sb->s_type, dentry, sb_flags, sb_flags_mask, FS_CONTEXT_FOR_RECONFIGURE); } EXPORT_SYMBOL(fs_context_for_reconfigure); struct fs_context *fs_context_for_submount(struct file_system_type *type, struct dentry *reference) { return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT); } EXPORT_SYMBOL(fs_context_for_submount); void fc_drop_locked(struct fs_context *fc) { struct super_block *sb = fc->root->d_sb; dput(fc->root); fc->root = NULL; deactivate_locked_super(sb); } static void legacy_fs_context_free(struct fs_context *fc); /** * vfs_dup_fc_config: Duplicate a filesystem context. * @src_fc: The context to copy. */ struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc) { struct fs_context *fc; int ret; if (!src_fc->ops->dup) return ERR_PTR(-EOPNOTSUPP); fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL); if (!fc) return ERR_PTR(-ENOMEM); mutex_init(&fc->uapi_mutex); fc->fs_private = NULL; fc->s_fs_info = NULL; fc->source = NULL; fc->security = NULL; get_filesystem(fc->fs_type); get_net(fc->net_ns); get_user_ns(fc->user_ns); get_cred(fc->cred); if (fc->log.log) refcount_inc(&fc->log.log->usage); /* Can't call put until we've called ->dup */ ret = fc->ops->dup(fc, src_fc); if (ret < 0) goto err_fc; ret = security_fs_context_dup(fc, src_fc); if (ret < 0) goto err_fc; return fc; err_fc: put_fs_context(fc); return ERR_PTR(ret); } EXPORT_SYMBOL(vfs_dup_fs_context); /** * logfc - Log a message to a filesystem context * @fc: The filesystem context to log to. * @fmt: The format of the buffer. */ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...) { va_list va; struct va_format vaf = {.fmt = fmt, .va = &va}; va_start(va, fmt); if (!log) { switch (level) { case 'w': printk(KERN_WARNING "%s%s%pV\n", prefix ? prefix : "", prefix ? ": " : "", &vaf); break; case 'e': printk(KERN_ERR "%s%s%pV\n", prefix ? prefix : "", prefix ? ": " : "", &vaf); break; default: printk(KERN_NOTICE "%s%s%pV\n", prefix ? prefix : "", prefix ? ": " : "", &vaf); break; } } else { unsigned int logsize = ARRAY_SIZE(log->buffer); u8 index; char *q = kasprintf(GFP_KERNEL, "%c %s%s%pV\n", level, prefix ? prefix : "", prefix ? ": " : "", &vaf); index = log->head & (logsize - 1); BUILD_BUG_ON(sizeof(log->head) != sizeof(u8) || sizeof(log->tail) != sizeof(u8)); if ((u8)(log->head - log->tail) == logsize) { /* The buffer is full, discard the oldest message */ if (log->need_free & (1 << index)) kfree(log->buffer[index]); log->tail++; } log->buffer[index] = q ? q : "OOM: Can't store error string"; if (q) log->need_free |= 1 << index; else log->need_free &= ~(1 << index); log->head++; } va_end(va); } EXPORT_SYMBOL(logfc); /* * Free a logging structure. */ static void put_fc_log(struct fs_context *fc) { struct fc_log *log = fc->log.log; int i; if (log) { if (refcount_dec_and_test(&log->usage)) { fc->log.log = NULL; for (i = 0; i <= 7; i++) if (log->need_free & (1 << i)) kfree(log->buffer[i]); kfree(log); } } } /** * put_fs_context - Dispose of a superblock configuration context. * @fc: The context to dispose of. */ void put_fs_context(struct fs_context *fc) { struct super_block *sb; if (fc->root) { sb = fc->root->d_sb; dput(fc->root); fc->root = NULL; deactivate_super(sb); } if (fc->need_free && fc->ops && fc->ops->free) fc->ops->free(fc); security_free_mnt_opts(&fc->security); put_net(fc->net_ns); put_user_ns(fc->user_ns); put_cred(fc->cred); put_fc_log(fc); put_filesystem(fc->fs_type); kfree(fc->source); kfree(fc); } EXPORT_SYMBOL(put_fs_context); /* * Free the config for a filesystem that doesn't support fs_context. */ static void legacy_fs_context_free(struct fs_context *fc) { struct legacy_fs_context *ctx = fc->fs_private; if (ctx) { if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) kfree(ctx->legacy_data); kfree(ctx); } } /* * Duplicate a legacy config. */ static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) { struct legacy_fs_context *ctx; struct legacy_fs_context *src_ctx = src_fc->fs_private; ctx = kmemdup(src_ctx, sizeof(*src_ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) { ctx->legacy_data = kmemdup(src_ctx->legacy_data, src_ctx->data_size, GFP_KERNEL); if (!ctx->legacy_data) { kfree(ctx); return -ENOMEM; } } fc->fs_private = ctx; return 0; } /* * Add a parameter to a legacy config. We build up a comma-separated list of * options. */ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct legacy_fs_context *ctx = fc->fs_private; unsigned int size = ctx->data_size; size_t len = 0; if (strcmp(param->key, "source") == 0) { if (param->type != fs_value_is_string) return invalf(fc, "VFS: Legacy: Non-string source"); if (fc->source) return invalf(fc, "VFS: Legacy: Multiple sources"); fc->source = param->string; param->string = NULL; return 0; } if (ctx->param_type == LEGACY_FS_MONOLITHIC_PARAMS) return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options"); switch (param->type) { case fs_value_is_string: len = 1 + param->size; fallthrough; case fs_value_is_flag: len += strlen(param->key); break; default: return invalf(fc, "VFS: Legacy: Parameter type for '%s' not supported", param->key); } if (len > PAGE_SIZE - 2 - size) return invalf(fc, "VFS: Legacy: Cumulative options too large"); if (strchr(param->key, ',') || (param->type == fs_value_is_string && memchr(param->string, ',', param->size))) return invalf(fc, "VFS: Legacy: Option '%s' contained comma", param->key); if (!ctx->legacy_data) { ctx->legacy_data = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!ctx->legacy_data) return -ENOMEM; } ctx->legacy_data[size++] = ','; len = strlen(param->key); memcpy(ctx->legacy_data + size, param->key, len); size += len; if (param->type == fs_value_is_string) { ctx->legacy_data[size++] = '='; memcpy(ctx->legacy_data + size, param->string, param->size); size += param->size; } ctx->legacy_data[size] = '\0'; ctx->data_size = size; ctx->param_type = LEGACY_FS_INDIVIDUAL_PARAMS; return 0; } /* * Add monolithic mount data. */ static int legacy_parse_monolithic(struct fs_context *fc, void *data) { struct legacy_fs_context *ctx = fc->fs_private; if (ctx->param_type != LEGACY_FS_UNSET_PARAMS) { pr_warn("VFS: Can't mix monolithic and individual options\n"); return -EINVAL; } ctx->legacy_data = data; ctx->param_type = LEGACY_FS_MONOLITHIC_PARAMS; if (!ctx->legacy_data) return 0; if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA) return 0; return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security); } /* * Get a mountable root with the legacy mount command. */ static int legacy_get_tree(struct fs_context *fc) { struct legacy_fs_context *ctx = fc->fs_private; struct super_block *sb; struct dentry *root; root = fc->fs_type->mount(fc->fs_type, fc->sb_flags, fc->source, ctx->legacy_data); if (IS_ERR(root)) return PTR_ERR(root); sb = root->d_sb; BUG_ON(!sb); fc->root = root; return 0; } /* * Handle remount. */ static int legacy_reconfigure(struct fs_context *fc) { struct legacy_fs_context *ctx = fc->fs_private; struct super_block *sb = fc->root->d_sb; if (!sb->s_op->remount_fs) return 0; return sb->s_op->remount_fs(sb, &fc->sb_flags, ctx ? ctx->legacy_data : NULL); } const struct fs_context_operations legacy_fs_context_ops = { .free = legacy_fs_context_free, .dup = legacy_fs_context_dup, .parse_param = legacy_parse_param, .parse_monolithic = legacy_parse_monolithic, .get_tree = legacy_get_tree, .reconfigure = legacy_reconfigure, }; /* * Initialise a legacy context for a filesystem that doesn't support * fs_context. */ static int legacy_init_fs_context(struct fs_context *fc) { fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL); if (!fc->fs_private) return -ENOMEM; fc->ops = &legacy_fs_context_ops; return 0; } int parse_monolithic_mount_data(struct fs_context *fc, void *data) { int (*monolithic_mount_data)(struct fs_context *, void *); monolithic_mount_data = fc->ops->parse_monolithic; if (!monolithic_mount_data) monolithic_mount_data = generic_parse_monolithic; return monolithic_mount_data(fc, data); } /* * Clean up a context after performing an action on it and put it into a state * from where it can be used to reconfigure a superblock. * * Note that here we do only the parts that can't fail; the rest is in * finish_clean_context() below and in between those fs_context is marked * FS_CONTEXT_AWAITING_RECONF. The reason for splitup is that after * successful mount or remount we need to report success to userland. * Trying to do full reinit (for the sake of possible subsequent remount) * and failing to allocate memory would've put us into a nasty situation. * So here we only discard the old state and reinitialization is left * until we actually try to reconfigure. */ void vfs_clean_context(struct fs_context *fc) { if (fc->need_free && fc->ops && fc->ops->free) fc->ops->free(fc); fc->need_free = false; fc->fs_private = NULL; fc->s_fs_info = NULL; fc->sb_flags = 0; security_free_mnt_opts(&fc->security); kfree(fc->source); fc->source = NULL; fc->purpose = FS_CONTEXT_FOR_RECONFIGURE; fc->phase = FS_CONTEXT_AWAITING_RECONF; } int finish_clean_context(struct fs_context *fc) { int error; if (fc->phase != FS_CONTEXT_AWAITING_RECONF) return 0; if (fc->fs_type->init_fs_context) error = fc->fs_type->init_fs_context(fc); else error = legacy_init_fs_context(fc); if (unlikely(error)) { fc->phase = FS_CONTEXT_FAILED; return error; } fc->need_free = true; fc->phase = FS_CONTEXT_RECONF_PARAMS; return 0; }
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3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 // SPDX-License-Identifier: GPL-2.0+ /* * Base port operations for 8250/16550-type serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * Split from 8250_core.c, Copyright (C) 2001 Russell King. * * A note about mapbase / membase * * mapbase is the physical address of the IO port. * membase is an 'ioremapped' cookie. */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/gpio/consumer.h> #include <linux/sysrq.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/tty.h> #include <linux/ratelimit.h> #include <linux/tty_flip.h> #include <linux/serial.h> #include <linux/serial_8250.h> #include <linux/nmi.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/pm_runtime.h> #include <linux/ktime.h> #include <asm/io.h> #include <asm/irq.h> #include "8250.h" /* Nuvoton NPCM timeout register */ #define UART_NPCM_TOR 7 #define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */ /* * Debugging. */ #if 0 #define DEBUG_AUTOCONF(fmt...) printk(fmt) #else #define DEBUG_AUTOCONF(fmt...) do { } while (0) #endif #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) /* * Here we define the default xmit fifo size used for each type of UART. */ static const struct serial8250_config uart_config[] = { [PORT_UNKNOWN] = { .name = "unknown", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_8250] = { .name = "8250", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16450] = { .name = "16450", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550] = { .name = "16550", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550A] = { .name = "16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_CIRRUS] = { .name = "Cirrus", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16650] = { .name = "ST16650", .fifo_size = 1, .tx_loadsz = 1, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16650V2] = { .name = "ST16650V2", .fifo_size = 32, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_00, .rxtrig_bytes = {8, 16, 24, 28}, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16750] = { .name = "TI16750", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR7_64BYTE, .rxtrig_bytes = {1, 16, 32, 56}, .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE, }, [PORT_STARTECH] = { .name = "Startech", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16C950] = { .name = "16C950/954", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01, .rxtrig_bytes = {16, 32, 112, 120}, /* UART_CAP_EFR breaks billionon CF bluetooth card. */ .flags = UART_CAP_FIFO | UART_CAP_SLEEP, }, [PORT_16654] = { .name = "ST16654", .fifo_size = 64, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_10, .rxtrig_bytes = {8, 16, 56, 60}, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16850] = { .name = "XR16850", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_RSA] = { .name = "RSA", .fifo_size = 2048, .tx_loadsz = 2048, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11, .flags = UART_CAP_FIFO, }, [PORT_NS16550A] = { .name = "NS16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_NATSEMI, }, [PORT_XSCALE] = { .name = "XScale", .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE, }, [PORT_OCTEON] = { .name = "OCTEON", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO, }, [PORT_AR7] = { .name = "AR7", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00, .flags = UART_CAP_FIFO /* | UART_CAP_AFE */, }, [PORT_U6_16550A] = { .name = "U6_16550A", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_TEGRA] = { .name = "Tegra", .fifo_size = 32, .tx_loadsz = 8, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO | UART_CAP_RTOIE, }, [PORT_XR17D15X] = { .name = "XR17D15X", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_XR17V35X] = { .name = "XR17V35X", .fifo_size = 256, .tx_loadsz = 256, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 | UART_FCR_T_TRIG_11, .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_LPC3220] = { .name = "LPC3220", .fifo_size = 64, .tx_loadsz = 32, .fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00, .flags = UART_CAP_FIFO, }, [PORT_BRCM_TRUMANAGE] = { .name = "TruManage", .fifo_size = 1, .tx_loadsz = 1024, .flags = UART_CAP_HFIFO, }, [PORT_8250_CIR] = { .name = "CIR port" }, [PORT_ALTR_16550_F32] = { .name = "Altera 16550 FIFO32", .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 8, 16, 30}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_ALTR_16550_F64] = { .name = "Altera 16550 FIFO64", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 16, 32, 62}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_ALTR_16550_F128] = { .name = "Altera 16550 FIFO128", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 32, 64, 126}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, /* * tx_loadsz is set to 63-bytes instead of 64-bytes to implement * workaround of errata A-008006 which states that tx_loadsz should * be configured less than Maximum supported fifo bytes. */ [PORT_16550A_FSL64] = { .name = "16550A_FSL64", .fifo_size = 64, .tx_loadsz = 63, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR7_64BYTE, .flags = UART_CAP_FIFO, }, [PORT_RT2880] = { .name = "Palmchip BK-3103", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_DA830] = { .name = "TI DA8xx/66AK2x", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_MTK_BTIF] = { .name = "MediaTek BTIF", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, .flags = UART_CAP_FIFO, }, [PORT_NPCM] = { .name = "Nuvoton 16550", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_SUNIX] = { .name = "Sunix", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 32, 64, 112}, .flags = UART_CAP_FIFO | UART_CAP_SLEEP, }, }; /* Uart divisor latch read */ static int default_serial_dl_read(struct uart_8250_port *up) { /* Assign these in pieces to truncate any bits above 7. */ unsigned char dll = serial_in(up, UART_DLL); unsigned char dlm = serial_in(up, UART_DLM); return dll | dlm << 8; } /* Uart divisor latch write */ static void default_serial_dl_write(struct uart_8250_port *up, int value) { serial_out(up, UART_DLL, value & 0xff); serial_out(up, UART_DLM, value >> 8 & 0xff); } #ifdef CONFIG_SERIAL_8250_RT288X /* Au1x00/RT288x UART hardware has a weird register layout */ static const s8 au_io_in_map[8] = { 0, /* UART_RX */ 2, /* UART_IER */ 3, /* UART_IIR */ 5, /* UART_LCR */ 6, /* UART_MCR */ 7, /* UART_LSR */ 8, /* UART_MSR */ -1, /* UART_SCR (unmapped) */ }; static const s8 au_io_out_map[8] = { 1, /* UART_TX */ 2, /* UART_IER */ 4, /* UART_FCR */ 5, /* UART_LCR */ 6, /* UART_MCR */ -1, /* UART_LSR (unmapped) */ -1, /* UART_MSR (unmapped) */ -1, /* UART_SCR (unmapped) */ }; unsigned int au_serial_in(struct uart_port *p, int offset) { if (offset >= ARRAY_SIZE(au_io_in_map)) return UINT_MAX; offset = au_io_in_map[offset]; if (offset < 0) return UINT_MAX; return __raw_readl(p->membase + (offset << p->regshift)); } void au_serial_out(struct uart_port *p, int offset, int value) { if (offset >= ARRAY_SIZE(au_io_out_map)) return; offset = au_io_out_map[offset]; if (offset < 0) return; __raw_writel(value, p->membase + (offset << p->regshift)); } /* Au1x00 haven't got a standard divisor latch */ static int au_serial_dl_read(struct uart_8250_port *up) { return __raw_readl(up->port.membase + 0x28); } static void au_serial_dl_write(struct uart_8250_port *up, int value) { __raw_writel(value, up->port.membase + 0x28); } #endif static unsigned int hub6_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; outb(p->hub6 - 1 + offset, p->iobase); return inb(p->iobase + 1); } static void hub6_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; outb(p->hub6 - 1 + offset, p->iobase); outb(value, p->iobase + 1); } static unsigned int mem_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readb(p->membase + offset); } static void mem_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writeb(value, p->membase + offset); } static void mem16_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writew(value, p->membase + offset); } static unsigned int mem16_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readw(p->membase + offset); } static void mem32_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writel(value, p->membase + offset); } static unsigned int mem32_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readl(p->membase + offset); } static void mem32be_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; iowrite32be(value, p->membase + offset); } static unsigned int mem32be_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return ioread32be(p->membase + offset); } static unsigned int io_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return inb(p->iobase + offset); } static void io_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; outb(value, p->iobase + offset); } static int serial8250_default_handle_irq(struct uart_port *port); static void set_io_from_upio(struct uart_port *p) { struct uart_8250_port *up = up_to_u8250p(p); up->dl_read = default_serial_dl_read; up->dl_write = default_serial_dl_write; switch (p->iotype) { case UPIO_HUB6: p->serial_in = hub6_serial_in; p->serial_out = hub6_serial_out; break; case UPIO_MEM: p->serial_in = mem_serial_in; p->serial_out = mem_serial_out; break; case UPIO_MEM16: p->serial_in = mem16_serial_in; p->serial_out = mem16_serial_out; break; case UPIO_MEM32: p->serial_in = mem32_serial_in; p->serial_out = mem32_serial_out; break; case UPIO_MEM32BE: p->serial_in = mem32be_serial_in; p->serial_out = mem32be_serial_out; break; #ifdef CONFIG_SERIAL_8250_RT288X case UPIO_AU: p->serial_in = au_serial_in; p->serial_out = au_serial_out; up->dl_read = au_serial_dl_read; up->dl_write = au_serial_dl_write; break; #endif default: p->serial_in = io_serial_in; p->serial_out = io_serial_out; break; } /* Remember loaded iotype */ up->cur_iotype = p->iotype; p->handle_irq = serial8250_default_handle_irq; } static void serial_port_out_sync(struct uart_port *p, int offset, int value) { switch (p->iotype) { case UPIO_MEM: case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: p->serial_out(p, offset, value); p->serial_in(p, UART_LCR); /* safe, no side-effects */ break; default: p->serial_out(p, offset, value); } } /* * For the 16C950 */ static void serial_icr_write(struct uart_8250_port *up, int offset, int value) { serial_out(up, UART_SCR, offset); serial_out(up, UART_ICR, value); } static unsigned int serial_icr_read(struct uart_8250_port *up, int offset) { unsigned int value; serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD); serial_out(up, UART_SCR, offset); value = serial_in(up, UART_ICR); serial_icr_write(up, UART_ACR, up->acr); return value; } /* * FIFO support. */ static void serial8250_clear_fifos(struct uart_8250_port *p) { if (p->capabilities & UART_CAP_FIFO) { serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_out(p, UART_FCR, 0); } } static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t); static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t); void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p) { serial8250_clear_fifos(p); serial_out(p, UART_FCR, p->fcr); } EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos); void serial8250_rpm_get(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_get_sync(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_get); void serial8250_rpm_put(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_mark_last_busy(p->port.dev); pm_runtime_put_autosuspend(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_put); /** * serial8250_em485_init() - put uart_8250_port into rs485 emulating * @p: uart_8250_port port instance * * The function is used to start rs485 software emulating on the * &struct uart_8250_port* @p. Namely, RTS is switched before/after * transmission. The function is idempotent, so it is safe to call it * multiple times. * * The caller MUST enable interrupt on empty shift register before * calling serial8250_em485_init(). This interrupt is not a part of * 8250 standard, but implementation defined. * * The function is supposed to be called from .rs485_config callback * or from any other callback protected with p->port.lock spinlock. * * See also serial8250_em485_destroy() * * Return 0 - success, -errno - otherwise */ static int serial8250_em485_init(struct uart_8250_port *p) { if (p->em485) return 0; p->em485 = kmalloc(sizeof(struct uart_8250_em485), GFP_ATOMIC); if (!p->em485) return -ENOMEM; hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); p->em485->stop_tx_timer.function = &serial8250_em485_handle_stop_tx; p->em485->start_tx_timer.function = &serial8250_em485_handle_start_tx; p->em485->port = p; p->em485->active_timer = NULL; p->em485->tx_stopped = true; p->rs485_stop_tx(p); return 0; } /** * serial8250_em485_destroy() - put uart_8250_port into normal state * @p: uart_8250_port port instance * * The function is used to stop rs485 software emulating on the * &struct uart_8250_port* @p. The function is idempotent, so it is safe to * call it multiple times. * * The function is supposed to be called from .rs485_config callback * or from any other callback protected with p->port.lock spinlock. * * See also serial8250_em485_init() */ void serial8250_em485_destroy(struct uart_8250_port *p) { if (!p->em485) return; hrtimer_cancel(&p->em485->start_tx_timer); hrtimer_cancel(&p->em485->stop_tx_timer); kfree(p->em485); p->em485 = NULL; } EXPORT_SYMBOL_GPL(serial8250_em485_destroy); /** * serial8250_em485_config() - generic ->rs485_config() callback * @port: uart port * @rs485: rs485 settings * * Generic callback usable by 8250 uart drivers to activate rs485 settings * if the uart is incapable of driving RTS as a Transmit Enable signal in * hardware, relying on software emulation instead. */ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485) { struct uart_8250_port *up = up_to_u8250p(port); /* pick sane settings if the user hasn't */ if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) == !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { rs485->flags |= SER_RS485_RTS_ON_SEND; rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; } /* clamp the delays to [0, 100ms] */ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U); rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U); memset(rs485->padding, 0, sizeof(rs485->padding)); port->rs485 = *rs485; gpiod_set_value(port->rs485_term_gpio, rs485->flags & SER_RS485_TERMINATE_BUS); /* * Both serial8250_em485_init() and serial8250_em485_destroy() * are idempotent. */ if (rs485->flags & SER_RS485_ENABLED) { int ret = serial8250_em485_init(up); if (ret) { rs485->flags &= ~SER_RS485_ENABLED; port->rs485.flags &= ~SER_RS485_ENABLED; } return ret; } serial8250_em485_destroy(up); return 0; } EXPORT_SYMBOL_GPL(serial8250_em485_config); /* * These two wrappers ensure that enable_runtime_pm_tx() can be called more than * once and disable_runtime_pm_tx() will still disable RPM because the fifo is * empty and the HW can idle again. */ void serial8250_rpm_get_tx(struct uart_8250_port *p) { unsigned char rpm_active; if (!(p->capabilities & UART_CAP_RPM)) return; rpm_active = xchg(&p->rpm_tx_active, 1); if (rpm_active) return; pm_runtime_get_sync(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx); void serial8250_rpm_put_tx(struct uart_8250_port *p) { unsigned char rpm_active; if (!(p->capabilities & UART_CAP_RPM)) return; rpm_active = xchg(&p->rpm_tx_active, 0); if (!rpm_active) return; pm_runtime_mark_last_busy(p->port.dev); pm_runtime_put_autosuspend(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_put_tx); /* * IER sleep support. UARTs which have EFRs need the "extended * capability" bit enabled. Note that on XR16C850s, we need to * reset LCR to write to IER. */ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) { unsigned char lcr = 0, efr = 0; serial8250_rpm_get(p); if (p->capabilities & UART_CAP_SLEEP) { if (p->capabilities & UART_CAP_EFR) { lcr = serial_in(p, UART_LCR); efr = serial_in(p, UART_EFR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, UART_EFR_ECB); serial_out(p, UART_LCR, 0); } serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); if (p->capabilities & UART_CAP_EFR) { serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, efr); serial_out(p, UART_LCR, lcr); } } serial8250_rpm_put(p); } #ifdef CONFIG_SERIAL_8250_RSA /* * Attempts to turn on the RSA FIFO. Returns zero on failure. * We set the port uart clock rate if we succeed. */ static int __enable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; mode = serial_in(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; if (!result) { serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO); mode = serial_in(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16; return result; } static void enable_rsa(struct uart_8250_port *up) { if (up->port.type == PORT_RSA) { if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); __enable_rsa(up); spin_unlock_irq(&up->port.lock); } if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_out(up, UART_RSA_FRR, 0); } } /* * Attempts to turn off the RSA FIFO. Returns zero on failure. * It is unknown why interrupts were disabled in here. However, * the caller is expected to preserve this behaviour by grabbing * the spinlock before calling this function. */ static void disable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; if (up->port.type == PORT_RSA && up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); mode = serial_in(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); if (!result) { serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO); mode = serial_in(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; spin_unlock_irq(&up->port.lock); } } #endif /* CONFIG_SERIAL_8250_RSA */ /* * This is a quickie test to see how big the FIFO is. * It doesn't work at all the time, more's the pity. */ static int size_fifo(struct uart_8250_port *up) { unsigned char old_fcr, old_mcr, old_lcr; unsigned short old_dl; int count; old_lcr = serial_in(up, UART_LCR); serial_out(up, UART_LCR, 0); old_fcr = serial_in(up, UART_FCR); old_mcr = serial8250_in_MCR(up); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial8250_out_MCR(up, UART_MCR_LOOP); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); old_dl = serial_dl_read(up); serial_dl_write(up, 0x0001); serial_out(up, UART_LCR, 0x03); for (count = 0; count < 256; count++) serial_out(up, UART_TX, count); mdelay(20);/* FIXME - schedule_timeout */ for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) && (count < 256); count++) serial_in(up, UART_RX); serial_out(up, UART_FCR, old_fcr); serial8250_out_MCR(up, old_mcr); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); serial_dl_write(up, old_dl); serial_out(up, UART_LCR, old_lcr); return count; } /* * Read UART ID using the divisor method - set DLL and DLM to zero * and the revision will be in DLL and device type in DLM. We * preserve the device state across this. */ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p) { unsigned char old_lcr; unsigned int id, old_dl; old_lcr = serial_in(p, UART_LCR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A); old_dl = serial_dl_read(p); serial_dl_write(p, 0); id = serial_dl_read(p); serial_dl_write(p, old_dl); serial_out(p, UART_LCR, old_lcr); return id; } /* * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's. * When this function is called we know it is at least a StarTech * 16650 V2, but it might be one of several StarTech UARTs, or one of * its clones. (We treat the broken original StarTech 16650 V1 as a * 16550, and why not? Startech doesn't seem to even acknowledge its * existence.) * * What evil have men's minds wrought... */ static void autoconfig_has_efr(struct uart_8250_port *up) { unsigned int id1, id2, id3, rev; /* * Everything with an EFR has SLEEP */ up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; /* * First we check to see if it's an Oxford Semiconductor UART. * * If we have to do this here because some non-National * Semiconductor clone chips lock up if you try writing to the * LSR register (which serial_icr_read does) */ /* * Check for Oxford Semiconductor 16C950. * * EFR [4] must be set else this test fails. * * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca) * claims that it's needed for 952 dual UART's (which are not * recommended for new designs). */ up->acr = 0; serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, UART_EFR_ECB); serial_out(up, UART_LCR, 0x00); id1 = serial_icr_read(up, UART_ID1); id2 = serial_icr_read(up, UART_ID2); id3 = serial_icr_read(up, UART_ID3); rev = serial_icr_read(up, UART_REV); DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev); if (id1 == 0x16 && id2 == 0xC9 && (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) { up->port.type = PORT_16C950; /* * Enable work around for the Oxford Semiconductor 952 rev B * chip which causes it to seriously miscalculate baud rates * when DLL is 0. */ if (id3 == 0x52 && rev == 0x01) up->bugs |= UART_BUG_QUOT; return; } /* * We check for a XR16C850 by setting DLL and DLM to 0, and then * reading back DLL and DLM. The chip type depends on the DLM * value read back: * 0x10 - XR16C850 and the DLL contains the chip revision. * 0x12 - XR16C2850. * 0x14 - XR16C854. */ id1 = autoconfig_read_divisor_id(up); DEBUG_AUTOCONF("850id=%04x ", id1); id2 = id1 >> 8; if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) { up->port.type = PORT_16850; return; } /* * It wasn't an XR16C850. * * We distinguish between the '654 and the '650 by counting * how many bytes are in the FIFO. I'm using this for now, * since that's the technique that was sent to me in the * serial driver update, but I'm not convinced this works. * I've had problems doing this in the past. -TYT */ if (size_fifo(up) == 64) up->port.type = PORT_16654; else up->port.type = PORT_16650V2; } /* * We detected a chip without a FIFO. Only two fall into * this category - the original 8250 and the 16450. The * 16450 has a scratch register (accessible with LCR=0) */ static void autoconfig_8250(struct uart_8250_port *up) { unsigned char scratch, status1, status2; up->port.type = PORT_8250; scratch = serial_in(up, UART_SCR); serial_out(up, UART_SCR, 0xa5); status1 = serial_in(up, UART_SCR); serial_out(up, UART_SCR, 0x5a); status2 = serial_in(up, UART_SCR); serial_out(up, UART_SCR, scratch); if (status1 == 0xa5 && status2 == 0x5a) up->port.type = PORT_16450; } static int broken_efr(struct uart_8250_port *up) { /* * Exar ST16C2550 "A2" devices incorrectly detect as * having an EFR, and report an ID of 0x0201. See * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html */ if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16) return 1; return 0; } /* * We know that the chip has FIFOs. Does it have an EFR? The * EFR is located in the same register position as the IIR and * we know the top two bits of the IIR are currently set. The * EFR should contain zero. Try to read the EFR. */ static void autoconfig_16550a(struct uart_8250_port *up) { unsigned char status1, status2; unsigned int iersave; up->port.type = PORT_16550A; up->capabilities |= UART_CAP_FIFO; if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS)) return; /* * Check for presence of the EFR when DLAB is set. * Only ST16C650V1 UARTs pass this test. */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); if (serial_in(up, UART_EFR) == 0) { serial_out(up, UART_EFR, 0xA8); if (serial_in(up, UART_EFR) != 0) { DEBUG_AUTOCONF("EFRv1 "); up->port.type = PORT_16650; up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; } else { serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status1 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, 0); serial_out(up, UART_LCR, 0); if (status1 == 7) up->port.type = PORT_16550A_FSL64; else DEBUG_AUTOCONF("Motorola 8xxx DUART "); } serial_out(up, UART_EFR, 0); return; } /* * Maybe it requires 0xbf to be written to the LCR. * (other ST16C650V2 UARTs, TI16C752A, etc) */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) { DEBUG_AUTOCONF("EFRv2 "); autoconfig_has_efr(up); return; } /* * Check for a National Semiconductor SuperIO chip. * Attempt to switch to bank 2, read the value of the LOOP bit * from EXCR1. Switch back to bank 0, change it in MCR. Then * switch back to bank 2, read it from EXCR1 again and check * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2 */ serial_out(up, UART_LCR, 0); status1 = serial8250_in_MCR(up); serial_out(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ if (!((status2 ^ status1) & UART_MCR_LOOP)) { serial_out(up, UART_LCR, 0); serial8250_out_MCR(up, status1 ^ UART_MCR_LOOP); serial_out(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ serial_out(up, UART_LCR, 0); serial8250_out_MCR(up, status1); if ((status2 ^ status1) & UART_MCR_LOOP) { unsigned short quot; serial_out(up, UART_LCR, 0xE0); quot = serial_dl_read(up); quot <<= 3; if (ns16550a_goto_highspeed(up)) serial_dl_write(up, quot); serial_out(up, UART_LCR, 0); up->port.uartclk = 921600*16; up->port.type = PORT_NS16550A; up->capabilities |= UART_NATSEMI; return; } } /* * No EFR. Try to detect a TI16750, which only sets bit 5 of * the IIR when 64 byte FIFO mode is enabled when DLAB is set. * Try setting it with and without DLAB set. Cheap clones * set bit 5 without DLAB set. */ serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status1 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status2 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(up, UART_LCR, 0); DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2); if (status1 == 6 && status2 == 7) { up->port.type = PORT_16750; up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP; return; } /* * Try writing and reading the UART_IER_UUE bit (b6). * If it works, this is probably one of the Xscale platform's * internal UARTs. * We're going to explicitly set the UUE bit to 0 before * trying to write and read a 1 just to make sure it's not * already a 1 and maybe locked there before we even start start. */ iersave = serial_in(up, UART_IER); serial_out(up, UART_IER, iersave & ~UART_IER_UUE); if (!(serial_in(up, UART_IER) & UART_IER_UUE)) { /* * OK it's in a known zero state, try writing and reading * without disturbing the current state of the other bits. */ serial_out(up, UART_IER, iersave | UART_IER_UUE); if (serial_in(up, UART_IER) & UART_IER_UUE) { /* * It's an Xscale. * We'll leave the UART_IER_UUE bit set to 1 (enabled). */ DEBUG_AUTOCONF("Xscale "); up->port.type = PORT_XSCALE; up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE; return; } } else { /* * If we got here we couldn't force the IER_UUE bit to 0. * Log it and continue. */ DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 "); } serial_out(up, UART_IER, iersave); /* * We distinguish between 16550A and U6 16550A by counting * how many bytes are in the FIFO. */ if (up->port.type == PORT_16550A && size_fifo(up) == 64) { up->port.type = PORT_U6_16550A; up->capabilities |= UART_CAP_AFE; } } /* * This routine is called by rs_init() to initialize a specific serial * port. It determines what type of UART chip this serial port is * using: 8250, 16450, 16550, 16550A. The important question is * whether or not this UART is a 16550A or not, since this will * determine whether or not we can use its FIFO features or not. */ static void autoconfig(struct uart_8250_port *up) { unsigned char status1, scratch, scratch2, scratch3; unsigned char save_lcr, save_mcr; struct uart_port *port = &up->port; unsigned long flags; unsigned int old_capabilities; if (!port->iobase && !port->mapbase && !port->membase) return; DEBUG_AUTOCONF("%s: autoconf (0x%04lx, 0x%p): ", port->name, port->iobase, port->membase); /* * We really do need global IRQs disabled here - we're going to * be frobbing the chips IRQ enable register to see if it exists. */ spin_lock_irqsave(&port->lock, flags); up->capabilities = 0; up->bugs = 0; if (!(port->flags & UPF_BUGGY_UART)) { /* * Do a simple existence test first; if we fail this, * there's no point trying anything else. * * 0x80 is used as a nonsense port to prevent against * false positives due to ISA bus float. The * assumption is that 0x80 is a non-existent port; * which should be safe since include/asm/io.h also * makes this assumption. * * Note: this is safe as long as MCR bit 4 is clear * and the device is in "PC" mode. */ scratch = serial_in(up, UART_IER); serial_out(up, UART_IER, 0); #ifdef __i386__ outb(0xff, 0x080); #endif /* * Mask out IER[7:4] bits for test as some UARTs (e.g. TL * 16C754B) allow only to modify them if an EFR bit is set. */ scratch2 = serial_in(up, UART_IER) & 0x0f; serial_out(up, UART_IER, 0x0F); #ifdef __i386__ outb(0, 0x080); #endif scratch3 = serial_in(up, UART_IER) & 0x0f; serial_out(up, UART_IER, scratch); if (scratch2 != 0 || scratch3 != 0x0F) { /* * We failed; there's nothing here */ spin_unlock_irqrestore(&port->lock, flags); DEBUG_AUTOCONF("IER test failed (%02x, %02x) ", scratch2, scratch3); goto out; } } save_mcr = serial8250_in_MCR(up); save_lcr = serial_in(up, UART_LCR); /* * Check to see if a UART is really there. Certain broken * internal modems based on the Rockwell chipset fail this * test, because they apparently don't implement the loopback * test mode. So this test is skipped on the COM 1 through * COM 4 ports. This *should* be safe, since no board * manufacturer would be stupid enough to design a board * that conflicts with COM 1-4 --- we hope! */ if (!(port->flags & UPF_SKIP_TEST)) { serial8250_out_MCR(up, UART_MCR_LOOP | 0x0A); status1 = serial_in(up, UART_MSR) & 0xF0; serial8250_out_MCR(up, save_mcr); if (status1 != 0x90) { spin_unlock_irqrestore(&port->lock, flags); DEBUG_AUTOCONF("LOOP test failed (%02x) ", status1); goto out; } } /* * We're pretty sure there's a port here. Lets find out what * type of port it is. The IIR top two bits allows us to find * out if it's 8250 or 16450, 16550, 16550A or later. This * determines what we test for next. * * We also initialise the EFR (if any) to zero for later. The * EFR occupies the same register location as the FCR and IIR. */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, 0); serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); /* Assign this as it is to truncate any bits above 7. */ scratch = serial_in(up, UART_IIR); switch (scratch >> 6) { case 0: autoconfig_8250(up); break; case 1: port->type = PORT_UNKNOWN; break; case 2: port->type = PORT_16550; break; case 3: autoconfig_16550a(up); break; } #ifdef CONFIG_SERIAL_8250_RSA /* * Only probe for RSA ports if we got the region. */ if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA && __enable_rsa(up)) port->type = PORT_RSA; #endif serial_out(up, UART_LCR, save_lcr); port->fifosize = uart_config[up->port.type].fifo_size; old_capabilities = up->capabilities; up->capabilities = uart_config[port->type].flags; up->tx_loadsz = uart_config[port->type].tx_loadsz; if (port->type == PORT_UNKNOWN) goto out_lock; /* * Reset the UART. */ #ifdef CONFIG_SERIAL_8250_RSA if (port->type == PORT_RSA) serial_out(up, UART_RSA_FRR, 0); #endif serial8250_out_MCR(up, save_mcr); serial8250_clear_fifos(up); serial_in(up, UART_RX); if (up->capabilities & UART_CAP_UUE) serial_out(up, UART_IER, UART_IER_UUE); else serial_out(up, UART_IER, 0); out_lock: spin_unlock_irqrestore(&port->lock, flags); /* * Check if the device is a Fintek F81216A */ if (port->type == PORT_16550A && port->iotype == UPIO_PORT) fintek_8250_probe(up); if (up->capabilities != old_capabilities) { dev_warn(port->dev, "detected caps %08x should be %08x\n", old_capabilities, up->capabilities); } out: DEBUG_AUTOCONF("iir=%d ", scratch); DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name); } static void autoconfig_irq(struct uart_8250_port *up) { struct uart_port *port = &up->port; unsigned char save_mcr, save_ier; unsigned char save_ICP = 0; unsigned int ICP = 0; unsigned long irqs; int irq; if (port->flags & UPF_FOURPORT) { ICP = (port->iobase & 0xfe0) | 0x1f; save_ICP = inb_p(ICP); outb_p(0x80, ICP); inb_p(ICP); } if (uart_console(port)) console_lock(); /* forget possible initially masked and pending IRQ */ probe_irq_off(probe_irq_on()); save_mcr = serial8250_in_MCR(up); save_ier = serial_in(up, UART_IER); serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2); irqs = probe_irq_on(); serial8250_out_MCR(up, 0); udelay(10); if (port->flags & UPF_FOURPORT) { serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); } else { serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2); } serial_out(up, UART_IER, 0x0f); /* enable all intrs */ serial_in(up, UART_LSR); serial_in(up, UART_RX); serial_in(up, UART_IIR); serial_in(up, UART_MSR); serial_out(up, UART_TX, 0xFF); udelay(20); irq = probe_irq_off(irqs); serial8250_out_MCR(up, save_mcr); serial_out(up, UART_IER, save_ier); if (port->flags & UPF_FOURPORT) outb_p(save_ICP, ICP); if (uart_console(port)) console_unlock(); port->irq = (irq > 0) ? irq : 0; } static void serial8250_stop_rx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; serial_port_out(port, UART_IER, up->ier); serial8250_rpm_put(up); } /** * serial8250_em485_stop_tx() - generic ->rs485_stop_tx() callback * @p: uart 8250 port * * Generic callback usable by 8250 uart drivers to stop rs485 transmission. */ void serial8250_em485_stop_tx(struct uart_8250_port *p) { unsigned char mcr = serial8250_in_MCR(p); if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND) mcr |= UART_MCR_RTS; else mcr &= ~UART_MCR_RTS; serial8250_out_MCR(p, mcr); /* * Empty the RX FIFO, we are not interested in anything * received during the half-duplex transmission. * Enable previously disabled RX interrupts. */ if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) { serial8250_clear_and_reinit_fifos(p); p->ier |= UART_IER_RLSI | UART_IER_RDI; serial_port_out(&p->port, UART_IER, p->ier); } } EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx); static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) { struct uart_8250_em485 *em485; struct uart_8250_port *p; unsigned long flags; em485 = container_of(t, struct uart_8250_em485, stop_tx_timer); p = em485->port; serial8250_rpm_get(p); spin_lock_irqsave(&p->port.lock, flags); if (em485->active_timer == &em485->stop_tx_timer) { p->rs485_stop_tx(p); em485->active_timer = NULL; em485->tx_stopped = true; } spin_unlock_irqrestore(&p->port.lock, flags); serial8250_rpm_put(p); return HRTIMER_NORESTART; } static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec) { long sec = msec / 1000; long nsec = (msec % 1000) * 1000000; ktime_t t = ktime_set(sec, nsec); hrtimer_start(hrt, t, HRTIMER_MODE_REL); } static void __stop_tx_rs485(struct uart_8250_port *p) { struct uart_8250_em485 *em485 = p->em485; /* * rs485_stop_tx() is going to set RTS according to config * AND flush RX FIFO if required. */ if (p->port.rs485.delay_rts_after_send > 0) { em485->active_timer = &em485->stop_tx_timer; start_hrtimer_ms(&em485->stop_tx_timer, p->port.rs485.delay_rts_after_send); } else { p->rs485_stop_tx(p); em485->active_timer = NULL; em485->tx_stopped = true; } } static inline void __do_stop_tx(struct uart_8250_port *p) { if (serial8250_clear_THRI(p)) serial8250_rpm_put_tx(p); } static inline void __stop_tx(struct uart_8250_port *p) { struct uart_8250_em485 *em485 = p->em485; if (em485) { unsigned char lsr = serial_in(p, UART_LSR); /* * To provide required timeing and allow FIFO transfer, * __stop_tx_rs485() must be called only when both FIFO and * shift register are empty. It is for device driver to enable * interrupt on TEMT. */ if ((lsr & BOTH_EMPTY) != BOTH_EMPTY) return; __stop_tx_rs485(p); } __do_stop_tx(p); } static void serial8250_stop_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); __stop_tx(up); /* * We really want to stop the transmitter from sending. */ if (port->type == PORT_16C950) { up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } serial8250_rpm_put(up); } static inline void __start_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); if (up->dma && !up->dma->tx_dma(up)) return; if (serial8250_set_THRI(up)) { if (up->bugs & UART_BUG_TXEN) { unsigned char lsr; lsr = serial_in(up, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; if (lsr & UART_LSR_THRE) serial8250_tx_chars(up); } } /* * Re-enable the transmitter if we disabled it. */ if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) { up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } } /** * serial8250_em485_start_tx() - generic ->rs485_start_tx() callback * @up: uart 8250 port * * Generic callback usable by 8250 uart drivers to start rs485 transmission. * Assumes that setting the RTS bit in the MCR register means RTS is high. * (Some chips use inverse semantics.) Further assumes that reception is * stoppable by disabling the UART_IER_RDI interrupt. (Some chips set the * UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.) */ void serial8250_em485_start_tx(struct uart_8250_port *up) { unsigned char mcr = serial8250_in_MCR(up); if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) serial8250_stop_rx(&up->port); if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND) mcr |= UART_MCR_RTS; else mcr &= ~UART_MCR_RTS; serial8250_out_MCR(up, mcr); } EXPORT_SYMBOL_GPL(serial8250_em485_start_tx); static inline void start_tx_rs485(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct uart_8250_em485 *em485 = up->em485; em485->active_timer = NULL; if (em485->tx_stopped) { em485->tx_stopped = false; up->rs485_start_tx(up); if (up->port.rs485.delay_rts_before_send > 0) { em485->active_timer = &em485->start_tx_timer; start_hrtimer_ms(&em485->start_tx_timer, up->port.rs485.delay_rts_before_send); return; } } __start_tx(port); } static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t) { struct uart_8250_em485 *em485; struct uart_8250_port *p; unsigned long flags; em485 = container_of(t, struct uart_8250_em485, start_tx_timer); p = em485->port; spin_lock_irqsave(&p->port.lock, flags); if (em485->active_timer == &em485->start_tx_timer) { __start_tx(&p->port); em485->active_timer = NULL; } spin_unlock_irqrestore(&p->port.lock, flags); return HRTIMER_NORESTART; } static void serial8250_start_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct uart_8250_em485 *em485 = up->em485; serial8250_rpm_get_tx(up); if (em485 && em485->active_timer == &em485->start_tx_timer) return; if (em485) start_tx_rs485(port); else __start_tx(port); } static void serial8250_throttle(struct uart_port *port) { port->throttle(port); } static void serial8250_unthrottle(struct uart_port *port) { port->unthrottle(port); } static void serial8250_disable_ms(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); /* no MSR capabilities */ if (up->bugs & UART_BUG_NOMSR) return; mctrl_gpio_disable_ms(up->gpios); up->ier &= ~UART_IER_MSI; serial_port_out(port, UART_IER, up->ier); } static void serial8250_enable_ms(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); /* no MSR capabilities */ if (up->bugs & UART_BUG_NOMSR) return; mctrl_gpio_enable_ms(up->gpios); up->ier |= UART_IER_MSI; serial8250_rpm_get(up); serial_port_out(port, UART_IER, up->ier); serial8250_rpm_put(up); } void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; unsigned char ch; char flag = TTY_NORMAL; if (likely(lsr & UART_LSR_DR)) ch = serial_in(up, UART_RX); else /* * Intel 82571 has a Serial Over Lan device that will * set UART_LSR_BI without setting UART_LSR_DR when * it receives a break. To avoid reading from the * receive buffer without UART_LSR_DR bit set, we * just force the read character to be 0 */ ch = 0; port->icount.rx++; lsr |= up->lsr_saved_flags; up->lsr_saved_flags = 0; if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) { if (lsr & UART_LSR_BI) { lsr &= ~(UART_LSR_FE | UART_LSR_PE); port->icount.brk++; /* * We do the SysRQ and SAK checking * here because otherwise the break * may get masked by ignore_status_mask * or read_status_mask. */ if (uart_handle_break(port)) return; } else if (lsr & UART_LSR_PE) port->icount.parity++; else if (lsr & UART_LSR_FE) port->icount.frame++; if (lsr & UART_LSR_OE) port->icount.overrun++; /* * Mask off conditions which should be ignored. */ lsr &= port->read_status_mask; if (lsr & UART_LSR_BI) { dev_dbg(port->dev, "handling break\n"); flag = TTY_BREAK; } else if (lsr & UART_LSR_PE) flag = TTY_PARITY; else if (lsr & UART_LSR_FE) flag = TTY_FRAME; } if (uart_prepare_sysrq_char(port, ch)) return; uart_insert_char(port, lsr, UART_LSR_OE, ch, flag); } EXPORT_SYMBOL_GPL(serial8250_read_char); /* * serial8250_rx_chars: processes according to the passed in LSR * value, and returns the remaining LSR bits not handled * by this Rx routine. */ unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; int max_count = 256; do { serial8250_read_char(up, lsr); if (--max_count == 0) break; lsr = serial_in(up, UART_LSR); } while (lsr & (UART_LSR_DR | UART_LSR_BI)); tty_flip_buffer_push(&port->state->port); return lsr; } EXPORT_SYMBOL_GPL(serial8250_rx_chars); void serial8250_tx_chars(struct uart_8250_port *up) { struct uart_port *port = &up->port; struct circ_buf *xmit = &port->state->xmit; int count; if (port->x_char) { serial_out(up, UART_TX, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (uart_tx_stopped(port)) { serial8250_stop_tx(port); return; } if (uart_circ_empty(xmit)) { __stop_tx(up); return; } count = up->tx_loadsz; do { serial_out(up, UART_TX, xmit->buf[xmit->tail]); if (up->bugs & UART_BUG_TXRACE) { /* * The Aspeed BMC virtual UARTs have a bug where data * may get stuck in the BMC's Tx FIFO from bursts of * writes on the APB interface. * * Delay back-to-back writes by a read cycle to avoid * stalling the VUART. Read a register that won't have * side-effects and discard the result. */ serial_in(up, UART_SCR); } xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (uart_circ_empty(xmit)) break; if ((up->capabilities & UART_CAP_HFIFO) && (serial_in(up, UART_LSR) & BOTH_EMPTY) != BOTH_EMPTY) break; /* The BCM2835 MINI UART THRE bit is really a not-full bit. */ if ((up->capabilities & UART_CAP_MINI) && !(serial_in(up, UART_LSR) & UART_LSR_THRE)) break; } while (--count > 0); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); /* * With RPM enabled, we have to wait until the FIFO is empty before the * HW can go idle. So we get here once again with empty FIFO and disable * the interrupt and RPM in __stop_tx() */ if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM)) __stop_tx(up); } EXPORT_SYMBOL_GPL(serial8250_tx_chars); /* Caller holds uart port lock */ unsigned int serial8250_modem_status(struct uart_8250_port *up) { struct uart_port *port = &up->port; unsigned int status = serial_in(up, UART_MSR); status |= up->msr_saved_flags; up->msr_saved_flags = 0; if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI && port->state != NULL) { if (status & UART_MSR_TERI) port->icount.rng++; if (status & UART_MSR_DDSR) port->icount.dsr++; if (status & UART_MSR_DDCD) uart_handle_dcd_change(port, status & UART_MSR_DCD); if (status & UART_MSR_DCTS) uart_handle_cts_change(port, status & UART_MSR_CTS); wake_up_interruptible(&port->state->port.delta_msr_wait); } return status; } EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); fallthrough; case UART_IIR_RLSI: return true; } return up->dma->rx_dma(up); } /* * This handles the interrupt from one port. */ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) { unsigned char status; unsigned long flags; struct uart_8250_port *up = up_to_u8250p(port); bool skip_rx = false; if (iir & UART_IIR_NO_INT) return 0; spin_lock_irqsave(&port->lock, flags); status = serial_port_in(port, UART_LSR); /* * If port is stopped and there are no error conditions in the * FIFO, then don't drain the FIFO, as this may lead to TTY buffer * overflow. Not servicing, RX FIFO would trigger auto HW flow * control when FIFO occupancy reaches preset threshold, thus * halting RX. This only works when auto HW flow control is * available. */ if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) && (port->status & (UPSTAT_AUTOCTS | UPSTAT_AUTORTS)) && !(port->read_status_mask & UART_LSR_DR)) skip_rx = true; if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) { if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); } serial8250_modem_status(up); if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE) && (up->ier & UART_IER_THRI)) serial8250_tx_chars(up); uart_unlock_and_check_sysrq(port, flags); return 1; } EXPORT_SYMBOL_GPL(serial8250_handle_irq); static int serial8250_default_handle_irq(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int iir; int ret; serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); serial8250_rpm_put(up); return ret; } /* * Newer 16550 compatible parts such as the SC16C650 & Altera 16550 Soft IP * have a programmable TX threshold that triggers the THRE interrupt in * the IIR register. In this case, the THRE interrupt indicates the FIFO * has space available. Load it up with tx_loadsz bytes. */ static int serial8250_tx_threshold_handle_irq(struct uart_port *port) { unsigned long flags; unsigned int iir = serial_port_in(port, UART_IIR); /* TX Threshold IRQ triggered so load up FIFO */ if ((iir & UART_IIR_ID) == UART_IIR_THRI) { struct uart_8250_port *up = up_to_u8250p(port); spin_lock_irqsave(&port->lock, flags); serial8250_tx_chars(up); spin_unlock_irqrestore(&port->lock, flags); } iir = serial_port_in(port, UART_IIR); return serial8250_handle_irq(port, iir); } static unsigned int serial8250_tx_empty(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; unsigned int lsr; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); lsr = serial_port_in(port, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; } unsigned int serial8250_do_get_mctrl(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int status; unsigned int val; serial8250_rpm_get(up); status = serial8250_modem_status(up); serial8250_rpm_put(up); val = serial8250_MSR_to_TIOCM(status); if (up->gpios) return mctrl_gpio_get(up->gpios, &val); return val; } EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl); static unsigned int serial8250_get_mctrl(struct uart_port *port) { if (port->get_mctrl) return port->get_mctrl(port); return serial8250_do_get_mctrl(port); } void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char mcr; if (port->rs485.flags & SER_RS485_ENABLED) { if (serial8250_in_MCR(up) & UART_MCR_RTS) mctrl |= TIOCM_RTS; else mctrl &= ~TIOCM_RTS; } mcr = serial8250_TIOCM_to_MCR(mctrl); mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr; serial8250_out_MCR(up, mcr); } EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl); static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { if (port->set_mctrl) port->set_mctrl(port, mctrl); else serial8250_do_set_mctrl(port, mctrl); } static void serial8250_break_ctl(struct uart_port *port, int break_state) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; else up->lcr &= ~UART_LCR_SBC; serial_port_out(port, UART_LCR, up->lcr); spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); } /* * Wait for transmitter & holding register to empty */ static void wait_for_xmitr(struct uart_8250_port *up, int bits) { unsigned int status, tmout = 10000; /* Wait up to 10ms for the character(s) to be sent. */ for (;;) { status = serial_in(up, UART_LSR); up->lsr_saved_flags |= status & LSR_SAVE_FLAGS; if ((status & bits) == bits) break; if (--tmout == 0) break; udelay(1); touch_nmi_watchdog(); } /* Wait up to 1s for flow control if necessary */ if (up->port.flags & UPF_CONS_FLOW) { for (tmout = 1000000; tmout; tmout--) { unsigned int msr = serial_in(up, UART_MSR); up->msr_saved_flags |= msr & MSR_SAVE_FLAGS; if (msr & UART_MSR_CTS) break; udelay(1); touch_nmi_watchdog(); } } } #ifdef CONFIG_CONSOLE_POLL /* * Console polling routines for writing and reading from the uart while * in an interrupt or debug context. */ static int serial8250_get_poll_char(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char lsr; int status; serial8250_rpm_get(up); lsr = serial_port_in(port, UART_LSR); if (!(lsr & UART_LSR_DR)) { status = NO_POLL_CHAR; goto out; } status = serial_port_in(port, UART_RX); out: serial8250_rpm_put(up); return status; } static void serial8250_put_poll_char(struct uart_port *port, unsigned char c) { unsigned int ier; struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); /* * First save the IER then disable the interrupts */ ier = serial_port_in(port, UART_IER); if (up->capabilities & UART_CAP_UUE) serial_port_out(port, UART_IER, UART_IER_UUE); else serial_port_out(port, UART_IER, 0); wait_for_xmitr(up, BOTH_EMPTY); /* * Send the character out. */ serial_port_out(port, UART_TX, c); /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); serial_port_out(port, UART_IER, ier); serial8250_rpm_put(up); } #endif /* CONFIG_CONSOLE_POLL */ int serial8250_do_startup(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; unsigned char lsr, iir; int retval; if (!port->fifosize) port->fifosize = uart_config[port->type].fifo_size; if (!up->tx_loadsz) up->tx_loadsz = uart_config[port->type].tx_loadsz; if (!up->capabilities) up->capabilities = uart_config[port->type].flags; up->mcr = 0; if (port->iotype != up->cur_iotype) set_io_from_upio(port); serial8250_rpm_get(up); if (port->type == PORT_16C950) { /* Wake up and initialize UART */ up->acr = 0; serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); serial_port_out(port, UART_EFR, UART_EFR_ECB); serial_port_out(port, UART_IER, 0); serial_port_out(port, UART_LCR, 0); serial_icr_write(up, UART_CSR, 0); /* Reset the UART */ serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); serial_port_out(port, UART_EFR, UART_EFR_ECB); serial_port_out(port, UART_LCR, 0); } if (port->type == PORT_DA830) { /* Reset the port */ serial_port_out(port, UART_IER, 0); serial_port_out(port, UART_DA830_PWREMU_MGMT, 0); mdelay(10); /* Enable Tx, Rx and free run mode */ serial_port_out(port, UART_DA830_PWREMU_MGMT, UART_DA830_PWREMU_MGMT_UTRST | UART_DA830_PWREMU_MGMT_URRST | UART_DA830_PWREMU_MGMT_FREE); } if (port->type == PORT_NPCM) { /* * Nuvoton calls the scratch register 'UART_TOR' (timeout * register). Enable it, and set TIOC (timeout interrupt * comparator) to be 0x20 for correct operation. */ serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20); } #ifdef CONFIG_SERIAL_8250_RSA /* * If this is an RSA port, see if we can kick it up to the * higher speed clock. */ enable_rsa(up); #endif /* * Clear the FIFO buffers and disable them. * (they will be reenabled in set_termios()) */ serial8250_clear_fifos(up); /* * Clear the interrupt registers. */ serial_port_in(port, UART_LSR); serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); /* * At this point, there's no way the LSR could still be 0xff; * if it is, then bail out, because there's likely no UART * here. */ if (!(port->flags & UPF_BUGGY_UART) && (serial_port_in(port, UART_LSR) == 0xff)) { dev_info_ratelimited(port->dev, "LSR safety check engaged!\n"); retval = -ENODEV; goto out; } /* * For a XR16C850, we need to set the trigger levels */ if (port->type == PORT_16850) { unsigned char fctr; serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX); serial_port_out(port, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX); serial_port_out(port, UART_TRG, UART_TRG_96); serial_port_out(port, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX); serial_port_out(port, UART_TRG, UART_TRG_96); serial_port_out(port, UART_LCR, 0); } /* * For the Altera 16550 variants, set TX threshold trigger level. */ if (((port->type == PORT_ALTR_16550_F32) || (port->type == PORT_ALTR_16550_F64) || (port->type == PORT_ALTR_16550_F128)) && (port->fifosize > 1)) { /* Bounds checking of TX threshold (valid 0 to fifosize-2) */ if ((up->tx_loadsz < 2) || (up->tx_loadsz > port->fifosize)) { dev_err(port->dev, "TX FIFO Threshold errors, skipping\n"); } else { serial_port_out(port, UART_ALTR_AFR, UART_ALTR_EN_TXFIFO_LW); serial_port_out(port, UART_ALTR_TX_LOW, port->fifosize - up->tx_loadsz); port->handle_irq = serial8250_tx_threshold_handle_irq; } } /* Check if we need to have shared IRQs */ if (port->irq && (up->port.flags & UPF_SHARE_IRQ)) up->port.irqflags |= IRQF_SHARED; if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) { unsigned char iir1; if (port->irqflags & IRQF_SHARED) disable_irq_nosync(port->irq); /* * Test for UARTs that do not reassert THRE when the * transmitter is idle and the interrupt has already * been cleared. Real 16550s should always reassert * this interrupt whenever the transmitter is idle and * the interrupt is enabled. Delays are necessary to * allow register changes to become visible. */ spin_lock_irqsave(&port->lock, flags); wait_for_xmitr(up, UART_LSR_THRE); serial_port_out_sync(port, UART_IER, UART_IER_THRI); udelay(1); /* allow THRE to set */ iir1 = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); serial_port_out_sync(port, UART_IER, UART_IER_THRI); udelay(1); /* allow a working UART time to re-assert THRE */ iir = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); spin_unlock_irqrestore(&port->lock, flags); if (port->irqflags & IRQF_SHARED) enable_irq(port->irq); /* * If the interrupt is not reasserted, or we otherwise * don't trust the iir, setup a timer to kick the UART * on a regular basis. */ if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) || up->port.flags & UPF_BUG_THRE) { up->bugs |= UART_BUG_THRE; } } retval = up->ops->setup_irq(up); if (retval) goto out; /* * Now, initialize the UART */ serial_port_out(port, UART_LCR, UART_LCR_WLEN8); spin_lock_irqsave(&port->lock, flags); if (up->port.flags & UPF_FOURPORT) { if (!up->port.irq) up->port.mctrl |= TIOCM_OUT1; } else /* * Most PC uarts need OUT2 raised to enable interrupts. */ if (port->irq) up->port.mctrl |= TIOCM_OUT2; serial8250_set_mctrl(port, port->mctrl); /* * Serial over Lan (SoL) hack: * Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be * used for Serial Over Lan. Those chips take a longer time than a * normal serial device to signalize that a transmission data was * queued. Due to that, the above test generally fails. One solution * would be to delay the reading of iir. However, this is not * reliable, since the timeout is variable. So, let's just don't * test if we receive TX irq. This way, we'll never enable * UART_BUG_TXEN. */ if (up->port.quirks & UPQ_NO_TXEN_TEST) goto dont_test_tx_en; /* * Do a quick test to see if we receive an interrupt when we enable * the TX irq. */ serial_port_out(port, UART_IER, UART_IER_THRI); lsr = serial_port_in(port, UART_LSR); iir = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { if (!(up->bugs & UART_BUG_TXEN)) { up->bugs |= UART_BUG_TXEN; dev_dbg(port->dev, "enabling bad tx status workarounds\n"); } } else { up->bugs &= ~UART_BUG_TXEN; } dont_test_tx_en: spin_unlock_irqrestore(&port->lock, flags); /* * Clear the interrupt registers again for luck, and clear the * saved flags to avoid getting false values from polling * routines or the previous session. */ serial_port_in(port, UART_LSR); serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); up->lsr_saved_flags = 0; up->msr_saved_flags = 0; /* * Request DMA channels for both RX and TX. */ if (up->dma) { const char *msg = NULL; if (uart_console(port)) msg = "forbid DMA for kernel console"; else if (serial8250_request_dma(up)) msg = "failed to request DMA"; if (msg) { dev_warn_ratelimited(port->dev, "%s\n", msg); up->dma = NULL; } } /* * Set the IER shadow for rx interrupts but defer actual interrupt * enable until after the FIFOs are enabled; otherwise, an already- * active sender can swamp the interrupt handler with "too much work". */ up->ier = UART_IER_RLSI | UART_IER_RDI; if (port->flags & UPF_FOURPORT) { unsigned int icp; /* * Enable interrupts on the AST Fourport board */ icp = (port->iobase & 0xfe0) | 0x01f; outb_p(0x80, icp); inb_p(icp); } retval = 0; out: serial8250_rpm_put(up); return retval; } EXPORT_SYMBOL_GPL(serial8250_do_startup); static int serial8250_startup(struct uart_port *port) { if (port->startup) return port->startup(port); return serial8250_do_startup(port); } void serial8250_do_shutdown(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; serial8250_rpm_get(up); /* * Disable interrupts from this port */ spin_lock_irqsave(&port->lock, flags); up->ier = 0; serial_port_out(port, UART_IER, 0); spin_unlock_irqrestore(&port->lock, flags); synchronize_irq(port->irq); if (up->dma) serial8250_release_dma(up); spin_lock_irqsave(&port->lock, flags); if (port->flags & UPF_FOURPORT) { /* reset interrupts on the AST Fourport board */ inb((port->iobase & 0xfe0) | 0x1f); port->mctrl |= TIOCM_OUT1; } else port->mctrl &= ~TIOCM_OUT2; serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); /* * Disable break condition and FIFOs */ serial_port_out(port, UART_LCR, serial_port_in(port, UART_LCR) & ~UART_LCR_SBC); serial8250_clear_fifos(up); #ifdef CONFIG_SERIAL_8250_RSA /* * Reset the RSA board back to 115kbps compat mode. */ disable_rsa(up); #endif /* * Read data port to reset things, and then unlink from * the IRQ chain. */ serial_port_in(port, UART_RX); serial8250_rpm_put(up); up->ops->release_irq(up); } EXPORT_SYMBOL_GPL(serial8250_do_shutdown); static void serial8250_shutdown(struct uart_port *port) { if (port->shutdown) port->shutdown(port); else serial8250_do_shutdown(port); } /* Nuvoton NPCM UARTs have a custom divisor calculation */ static unsigned int npcm_get_divisor(struct uart_8250_port *up, unsigned int baud) { struct uart_port *port = &up->port; return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; } static unsigned int serial8250_do_get_divisor(struct uart_port *port, unsigned int baud, unsigned int *frac) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int quot; /* * Handle magic divisors for baud rates above baud_base on * SMSC SuperIO chips. * */ if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/4)) quot = 0x8001; else if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/8)) quot = 0x8002; else if (up->port.type == PORT_NPCM) quot = npcm_get_divisor(up, baud); else quot = uart_get_divisor(port, baud); /* * Oxford Semi 952 rev B workaround */ if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0) quot++; return quot; } static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud, unsigned int *frac) { if (port->get_divisor) return port->get_divisor(port, baud, frac); return serial8250_do_get_divisor(port, baud, frac); } static unsigned char serial8250_compute_lcr(struct uart_8250_port *up, tcflag_t c_cflag) { unsigned char cval; switch (c_cflag & CSIZE) { case CS5: cval = UART_LCR_WLEN5; break; case CS6: cval = UART_LCR_WLEN6; break; case CS7: cval = UART_LCR_WLEN7; break; default: case CS8: cval = UART_LCR_WLEN8; break; } if (c_cflag & CSTOPB) cval |= UART_LCR_STOP; if (c_cflag & PARENB) { cval |= UART_LCR_PARITY; if (up->bugs & UART_BUG_PARITY) up->fifo_bug = true; } if (!(c_cflag & PARODD)) cval |= UART_LCR_EPAR; #ifdef CMSPAR if (c_cflag & CMSPAR) cval |= UART_LCR_SPAR; #endif return cval; } void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud, unsigned int quot, unsigned int quot_frac) { struct uart_8250_port *up = up_to_u8250p(port); /* Workaround to enable 115200 baud on OMAP1510 internal ports */ if (is_omap1510_8250(up)) { if (baud == 115200) { quot = 1; serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1); } else serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0); } /* * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2, * otherwise just set DLAB */ if (up->capabilities & UART_NATSEMI) serial_port_out(port, UART_LCR, 0xe0); else serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB); serial_dl_write(up, quot); } EXPORT_SYMBOL_GPL(serial8250_do_set_divisor); static void serial8250_set_divisor(struct uart_port *port, unsigned int baud, unsigned int quot, unsigned int quot_frac) { if (port->set_divisor) port->set_divisor(port, baud, quot, quot_frac); else serial8250_do_set_divisor(port, baud, quot, quot_frac); } static unsigned int serial8250_get_baud_rate(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { unsigned int tolerance = port->uartclk / 100; unsigned int min; unsigned int max; /* * Handle magic divisors for baud rates above baud_base on SMSC * Super I/O chips. Enable custom rates of clk/4 and clk/8, but * disable divisor values beyond 32767, which are unavailable. */ if (port->flags & UPF_MAGIC_MULTIPLIER) { min = port->uartclk / 16 / UART_DIV_MAX >> 1; max = (port->uartclk + tolerance) / 4; } else { min = port->uartclk / 16 / UART_DIV_MAX; max = (port->uartclk + tolerance) / 16; } /* * Ask the core to calculate the divisor for us. * Allow 1% tolerance at the upper limit so uart clks marginally * slower than nominal still match standard baud rates without * causing transmission errors. */ return uart_get_baud_rate(port, termios, old, min, max); } /* * Note in order to avoid the tty port mutex deadlock don't use the next method * within the uart port callbacks. Primarily it's supposed to be utilized to * handle a sudden reference clock rate change. */ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int baud, quot, frac = 0; struct ktermios *termios; unsigned long flags; mutex_lock(&port->state->port.mutex); if (port->uartclk == uartclk) goto out_lock; port->uartclk = uartclk; if (!tty_port_initialized(&port->state->port)) goto out_lock; termios = &port->state->port.tty->termios; baud = serial8250_get_baud_rate(port, termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); uart_update_timeout(port, termios->c_cflag, baud); serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); out_lock: mutex_unlock(&port->state->port.mutex); } EXPORT_SYMBOL_GPL(serial8250_update_uartclk); void serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char cval; unsigned long flags; unsigned int baud, quot, frac = 0; if (up->capabilities & UART_CAP_MINI) { termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR); if ((termios->c_cflag & CSIZE) == CS5 || (termios->c_cflag & CSIZE) == CS6) termios->c_cflag = (termios->c_cflag & ~CSIZE) | CS7; } cval = serial8250_compute_lcr(up, termios->c_cflag); baud = serial8250_get_baud_rate(port, termios, old); quot = serial8250_get_divisor(port, baud, &frac); /* * Ok, we're now changing the port state. Do it with * interrupts disabled. */ serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); up->lcr = cval; /* Save computed LCR */ if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) { /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */ if ((baud < 2400 && !up->dma) || up->fifo_bug) { up->fcr &= ~UART_FCR_TRIGGER_MASK; up->fcr |= UART_FCR_TRIGGER_1; } } /* * MCR-based auto flow control. When AFE is enabled, RTS will be * deasserted when the receive FIFO contains more characters than * the trigger, or the MCR RTS bit is cleared. */ if (up->capabilities & UART_CAP_AFE) { up->mcr &= ~UART_MCR_AFE; if (termios->c_cflag & CRTSCTS) up->mcr |= UART_MCR_AFE; } /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; if (termios->c_iflag & INPCK) port->read_status_mask |= UART_LSR_FE | UART_LSR_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= UART_LSR_BI; /* * Characteres to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= UART_LSR_BI; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART_LSR_OE; } /* * ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= UART_LSR_DR; /* * CTS flow control flag and modem status interrupts */ up->ier &= ~UART_IER_MSI; if (!(up->bugs & UART_BUG_NOMSR) && UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; if (up->capabilities & UART_CAP_UUE) up->ier |= UART_IER_UUE; if (up->capabilities & UART_CAP_RTOIE) up->ier |= UART_IER_RTOIE; serial_port_out(port, UART_IER, up->ier); if (up->capabilities & UART_CAP_EFR) { unsigned char efr = 0; /* * TI16C752/Startech hardware flow control. FIXME: * - TI16C752 requires control thresholds to be set. * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled. */ if (termios->c_cflag & CRTSCTS) efr |= UART_EFR_CTS; serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); if (port->flags & UPF_EXAR_EFR) serial_port_out(port, UART_XR_EFR, efr); else serial_port_out(port, UART_EFR, efr); } serial8250_set_divisor(port, baud, quot, frac); /* * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR * is written without DLAB set, this mode will be disabled. */ if (port->type == PORT_16750) serial_port_out(port, UART_FCR, up->fcr); serial_port_out(port, UART_LCR, up->lcr); /* reset DLAB */ if (port->type != PORT_16750) { /* emulated UARTs (Lucent Venus 167x) need two steps */ if (up->fcr & UART_FCR_ENABLE_FIFO) serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO); serial_port_out(port, UART_FCR, up->fcr); /* set fcr */ } serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); } EXPORT_SYMBOL(serial8250_do_set_termios); static void serial8250_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { if (port->set_termios) port->set_termios(port, termios, old); else serial8250_do_set_termios(port, termios, old); } void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios) { if (termios->c_line == N_PPS) { port->flags |= UPF_HARDPPS_CD; spin_lock_irq(&port->lock); serial8250_enable_ms(port); spin_unlock_irq(&port->lock); } else { port->flags &= ~UPF_HARDPPS_CD; if (!UART_ENABLE_MS(port, termios->c_cflag)) { spin_lock_irq(&port->lock); serial8250_disable_ms(port); spin_unlock_irq(&port->lock); } } } EXPORT_SYMBOL_GPL(serial8250_do_set_ldisc); static void serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios) { if (port->set_ldisc) port->set_ldisc(port, termios); else serial8250_do_set_ldisc(port, termios); } void serial8250_do_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct uart_8250_port *p = up_to_u8250p(port); serial8250_set_sleep(p, state != 0); } EXPORT_SYMBOL(serial8250_do_pm); static void serial8250_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { if (port->pm) port->pm(port, state, oldstate); else serial8250_do_pm(port, state, oldstate); } static unsigned int serial8250_port_size(struct uart_8250_port *pt) { if (pt->port.mapsize) return pt->port.mapsize; if (pt->port.iotype == UPIO_AU) { if (pt->port.type == PORT_RT2880) return 0x100; return 0x1000; } if (is_omap1_8250(pt)) return 0x16 << pt->port.regshift; return 8 << pt->port.regshift; } /* * Resource handling. */ static int serial8250_request_std_resource(struct uart_8250_port *up) { unsigned int size = serial8250_port_size(up); struct uart_port *port = &up->port; int ret = 0; switch (port->iotype) { case UPIO_AU: case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; if (!request_mem_region(port->mapbase, size, "serial")) { ret = -EBUSY; break; } if (port->flags & UPF_IOREMAP) { port->membase = ioremap(port->mapbase, size); if (!port->membase) { release_mem_region(port->mapbase, size); ret = -ENOMEM; } } break; case UPIO_HUB6: case UPIO_PORT: if (!request_region(port->iobase, size, "serial")) ret = -EBUSY; break; } return ret; } static void serial8250_release_std_resource(struct uart_8250_port *up) { unsigned int size = serial8250_port_size(up); struct uart_port *port = &up->port; switch (port->iotype) { case UPIO_AU: case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } release_mem_region(port->mapbase, size); break; case UPIO_HUB6: case UPIO_PORT: release_region(port->iobase, size); break; } } static void serial8250_release_port(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_release_std_resource(up); } static int serial8250_request_port(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); return serial8250_request_std_resource(up); } static int fcr_get_rxtrig_bytes(struct uart_8250_port *up) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; unsigned char bytes; bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)]; return bytes ? bytes : -EOPNOTSUPP; } static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; int i; if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)]) return -EOPNOTSUPP; for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) { if (bytes < conf_type->rxtrig_bytes[i]) /* Use the nearest lower value */ return (--i) << UART_FCR_R_TRIG_SHIFT; } return UART_FCR_R_TRIG_11; } static int do_get_rxtrig(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = state->uart_port; struct uart_8250_port *up = up_to_u8250p(uport); if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1) return -EINVAL; return fcr_get_rxtrig_bytes(up); } static int do_serial8250_get_rxtrig(struct tty_port *port) { int rxtrig_bytes; mutex_lock(&port->mutex); rxtrig_bytes = do_get_rxtrig(port); mutex_unlock(&port->mutex); return rxtrig_bytes; } static ssize_t rx_trig_bytes_show(struct device *dev, struct device_attribute *attr, char *buf) { struct tty_port *port = dev_get_drvdata(dev); int rxtrig_bytes; rxtrig_bytes = do_serial8250_get_rxtrig(port); if (rxtrig_bytes < 0) return rxtrig_bytes; return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes); } static int do_set_rxtrig(struct tty_port *port, unsigned char bytes) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = state->uart_port; struct uart_8250_port *up = up_to_u8250p(uport); int rxtrig; if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 || up->fifo_bug) return -EINVAL; rxtrig = bytes_to_fcr_rxtrig(up, bytes); if (rxtrig < 0) return rxtrig; serial8250_clear_fifos(up); up->fcr &= ~UART_FCR_TRIGGER_MASK; up->fcr |= (unsigned char)rxtrig; serial_out(up, UART_FCR, up->fcr); return 0; } static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes) { int ret; mutex_lock(&port->mutex); ret = do_set_rxtrig(port, bytes); mutex_unlock(&port->mutex); return ret; } static ssize_t rx_trig_bytes_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct tty_port *port = dev_get_drvdata(dev); unsigned char bytes; int ret; if (!count) return -EINVAL; ret = kstrtou8(buf, 10, &bytes); if (ret < 0) return ret; ret = do_serial8250_set_rxtrig(port, bytes); if (ret < 0) return ret; return count; } static DEVICE_ATTR_RW(rx_trig_bytes); static struct attribute *serial8250_dev_attrs[] = { &dev_attr_rx_trig_bytes.attr, NULL }; static struct attribute_group serial8250_dev_attr_group = { .attrs = serial8250_dev_attrs, }; static void register_dev_spec_attr_grp(struct uart_8250_port *up) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; if (conf_type->rxtrig_bytes[0]) up->port.attr_group = &serial8250_dev_attr_group; } static void serial8250_config_port(struct uart_port *port, int flags) { struct uart_8250_port *up = up_to_u8250p(port); int ret; /* * Find the region that we can probe for. This in turn * tells us whether we can probe for the type of port. */ ret = serial8250_request_std_resource(up); if (ret < 0) return; if (port->iotype != up->cur_iotype) set_io_from_upio(port); if (flags & UART_CONFIG_TYPE) autoconfig(up); if (port->rs485.flags & SER_RS485_ENABLED) port->rs485_config(port, &port->rs485); /* if access method is AU, it is a 16550 with a quirk */ if (port->type == PORT_16550A && port->iotype == UPIO_AU) up->bugs |= UART_BUG_NOMSR; /* HW bugs may trigger IRQ while IIR == NO_INT */ if (port->type == PORT_TEGRA) up->bugs |= UART_BUG_NOMSR; if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ) autoconfig_irq(up); if (port->type == PORT_UNKNOWN) serial8250_release_std_resource(up); register_dev_spec_attr_grp(up); up->fcr = uart_config[up->port.type].fcr; } static int serial8250_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->irq >= nr_irqs || ser->irq < 0 || ser->baud_base < 9600 || ser->type < PORT_UNKNOWN || ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS || ser->type == PORT_STARTECH) return -EINVAL; return 0; } static const char *serial8250_type(struct uart_port *port) { int type = port->type; if (type >= ARRAY_SIZE(uart_config)) type = 0; return uart_config[type].name; } static const struct uart_ops serial8250_pops = { .tx_empty = serial8250_tx_empty, .set_mctrl = serial8250_set_mctrl, .get_mctrl = serial8250_get_mctrl, .stop_tx = serial8250_stop_tx, .start_tx = serial8250_start_tx, .throttle = serial8250_throttle, .unthrottle = serial8250_unthrottle, .stop_rx = serial8250_stop_rx, .enable_ms = serial8250_enable_ms, .break_ctl = serial8250_break_ctl, .startup = serial8250_startup, .shutdown = serial8250_shutdown, .set_termios = serial8250_set_termios, .set_ldisc = serial8250_set_ldisc, .pm = serial8250_pm, .type = serial8250_type, .release_port = serial8250_release_port, .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = serial8250_get_poll_char, .poll_put_char = serial8250_put_poll_char, #endif }; void serial8250_init_port(struct uart_8250_port *up) { struct uart_port *port = &up->port; spin_lock_init(&port->lock); port->ops = &serial8250_pops; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); up->cur_iotype = 0xFF; } EXPORT_SYMBOL_GPL(serial8250_init_port); void serial8250_set_defaults(struct uart_8250_port *up) { struct uart_port *port = &up->port; if (up->port.flags & UPF_FIXED_TYPE) { unsigned int type = up->port.type; if (!up->port.fifosize) up->port.fifosize = uart_config[type].fifo_size; if (!up->tx_loadsz) up->tx_loadsz = uart_config[type].tx_loadsz; if (!up->capabilities) up->capabilities = uart_config[type].flags; } set_io_from_upio(port); /* default dma handlers */ if (up->dma) { if (!up->dma->tx_dma) up->dma->tx_dma = serial8250_tx_dma; if (!up->dma->rx_dma) up->dma->rx_dma = serial8250_rx_dma; } } EXPORT_SYMBOL_GPL(serial8250_set_defaults); #ifdef CONFIG_SERIAL_8250_CONSOLE static void serial8250_console_putchar(struct uart_port *port, int ch) { struct uart_8250_port *up = up_to_u8250p(port); wait_for_xmitr(up, UART_LSR_THRE); serial_port_out(port, UART_TX, ch); } /* * Restore serial console when h/w power-off detected */ static void serial8250_console_restore(struct uart_8250_port *up) { struct uart_port *port = &up->port; struct ktermios termios; unsigned int baud, quot, frac = 0; termios.c_cflag = port->cons->cflag; if (port->state->port.tty && termios.c_cflag == 0) termios.c_cflag = port->state->port.tty->termios.c_cflag; baud = serial8250_get_baud_rate(port, &termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); } /* * Print a string to the serial port trying not to disturb * any possible real use of the port... * * The console_lock must be held when we get here. * * Doing runtime PM is really a bad idea for the kernel console. * Thus, we assume the function is called when device is powered up. */ void serial8250_console_write(struct uart_8250_port *up, const char *s, unsigned int count) { struct uart_8250_em485 *em485 = up->em485; struct uart_port *port = &up->port; unsigned long flags; unsigned int ier; int locked = 1; touch_nmi_watchdog(); if (oops_in_progress) locked = spin_trylock_irqsave(&port->lock, flags); else spin_lock_irqsave(&port->lock, flags); /* * First save the IER then disable the interrupts */ ier = serial_port_in(port, UART_IER); if (up->capabilities & UART_CAP_UUE) serial_port_out(port, UART_IER, UART_IER_UUE); else serial_port_out(port, UART_IER, 0); /* check scratch reg to see if port powered off during system sleep */ if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) { serial8250_console_restore(up); up->canary = 0; } if (em485) { if (em485->tx_stopped) up->rs485_start_tx(up); mdelay(port->rs485.delay_rts_before_send); } uart_console_write(port, s, count, serial8250_console_putchar); /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); if (em485) { mdelay(port->rs485.delay_rts_after_send); if (em485->tx_stopped) up->rs485_stop_tx(up); } serial_port_out(port, UART_IER, ier); /* * The receive handling will happen properly because the * receive ready bit will still be set; it is not cleared * on read. However, modem control will not, we must * call it if we have saved something in the saved flags * while processing with interrupts off. */ if (up->msr_saved_flags) serial8250_modem_status(up); if (locked) spin_unlock_irqrestore(&port->lock, flags); } static unsigned int probe_baud(struct uart_port *port) { unsigned char lcr, dll, dlm; unsigned int quot; lcr = serial_port_in(port, UART_LCR); serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB); dll = serial_port_in(port, UART_DLL); dlm = serial_port_in(port, UART_DLM); serial_port_out(port, UART_LCR, lcr); quot = (dlm << 8) | dll; return (port->uartclk / 16) / quot; } int serial8250_console_setup(struct uart_port *port, char *options, bool probe) { int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int ret; if (!port->iobase && !port->membase) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else if (probe) baud = probe_baud(port); ret = uart_set_options(port, port->cons, baud, parity, bits, flow); if (ret) return ret; if (port->dev) pm_runtime_get_sync(port->dev); return 0; } int serial8250_console_exit(struct uart_port *port) { if (port->dev) pm_runtime_put_sync(port->dev); return 0; } #endif /* CONFIG_SERIAL_8250_CONSOLE */ MODULE_LICENSE("GPL");
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 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_RMAP_H #define _LINUX_RMAP_H /* * Declarations for Reverse Mapping functions in mm/rmap.c */ #include <linux/list.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/rwsem.h> #include <linux/memcontrol.h> #include <linux/highmem.h> /* * The anon_vma heads a list of private "related" vmas, to scan if * an anonymous page pointing to this anon_vma needs to be unmapped: * the vmas on the list will be related by forking, or by splitting. * * Since vmas come and go as they are split and merged (particularly * in mprotect), the mapping field of an anonymous page cannot point * directly to a vma: instead it points to an anon_vma, on whose list * the related vmas can be easily linked or unlinked. * * After unlinking the last vma on the list, we must garbage collect * the anon_vma object itself: we're guaranteed no page can be * pointing to this anon_vma once its vma list is empty. */ struct anon_vma { struct anon_vma *root; /* Root of this anon_vma tree */ struct rw_semaphore rwsem; /* W: modification, R: walking the list */ /* * The refcount is taken on an anon_vma when there is no * guarantee that the vma of page tables will exist for * the duration of the operation. A caller that takes * the reference is responsible for clearing up the * anon_vma if they are the last user on release */ atomic_t refcount; /* * Count of child anon_vmas and VMAs which points to this anon_vma. * * This counter is used for making decision about reusing anon_vma * instead of forking new one. See comments in function anon_vma_clone. */ unsigned degree; struct anon_vma *parent; /* Parent of this anon_vma */ /* * NOTE: the LSB of the rb_root.rb_node is set by * mm_take_all_locks() _after_ taking the above lock. So the * rb_root must only be read/written after taking the above lock * to be sure to see a valid next pointer. The LSB bit itself * is serialized by a system wide lock only visible to * mm_take_all_locks() (mm_all_locks_mutex). */ /* Interval tree of private "related" vmas */ struct rb_root_cached rb_root; }; /* * The copy-on-write semantics of fork mean that an anon_vma * can become associated with multiple processes. Furthermore, * each child process will have its own anon_vma, where new * pages for that process are instantiated. * * This structure allows us to find the anon_vmas associated * with a VMA, or the VMAs associated with an anon_vma. * The "same_vma" list contains the anon_vma_chains linking * all the anon_vmas associated with this VMA. * The "rb" field indexes on an interval tree the anon_vma_chains * which link all the VMAs associated with this anon_vma. */ struct anon_vma_chain { struct vm_area_struct *vma; struct anon_vma *anon_vma; struct list_head same_vma; /* locked by mmap_lock & page_table_lock */ struct rb_node rb; /* locked by anon_vma->rwsem */ unsigned long rb_subtree_last; #ifdef CONFIG_DEBUG_VM_RB unsigned long cached_vma_start, cached_vma_last; #endif }; enum ttu_flags { TTU_MIGRATION = 0x1, /* migration mode */ TTU_MUNLOCK = 0x2, /* munlock mode */ TTU_SPLIT_HUGE_PMD = 0x4, /* split huge PMD if any */ TTU_IGNORE_MLOCK = 0x8, /* ignore mlock */ TTU_SYNC = 0x10, /* avoid racy checks with PVMW_SYNC */ TTU_IGNORE_HWPOISON = 0x20, /* corrupted page is recoverable */ TTU_BATCH_FLUSH = 0x40, /* Batch TLB flushes where possible * and caller guarantees they will * do a final flush if necessary */ TTU_RMAP_LOCKED = 0x80, /* do not grab rmap lock: * caller holds it */ TTU_SPLIT_FREEZE = 0x100, /* freeze pte under splitting thp */ }; #ifdef CONFIG_MMU static inline void get_anon_vma(struct anon_vma *anon_vma) { atomic_inc(&anon_vma->refcount); } void __put_anon_vma(struct anon_vma *anon_vma); static inline void put_anon_vma(struct anon_vma *anon_vma) { if (atomic_dec_and_test(&anon_vma->refcount)) __put_anon_vma(anon_vma); } static inline void anon_vma_lock_write(struct anon_vma *anon_vma) { down_write(&anon_vma->root->rwsem); } static inline void anon_vma_unlock_write(struct anon_vma *anon_vma) { up_write(&anon_vma->root->rwsem); } static inline void anon_vma_lock_read(struct anon_vma *anon_vma) { down_read(&anon_vma->root->rwsem); } static inline void anon_vma_unlock_read(struct anon_vma *anon_vma) { up_read(&anon_vma->root->rwsem); } /* * anon_vma helper functions. */ void anon_vma_init(void); /* create anon_vma_cachep */ int __anon_vma_prepare(struct vm_area_struct *); void unlink_anon_vmas(struct vm_area_struct *); int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *); int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *); static inline int anon_vma_prepare(struct vm_area_struct *vma) { if (likely(vma->anon_vma)) return 0; return __anon_vma_prepare(vma); } static inline void anon_vma_merge(struct vm_area_struct *vma, struct vm_area_struct *next) { VM_BUG_ON_VMA(vma->anon_vma != next->anon_vma, vma); unlink_anon_vmas(next); } struct anon_vma *page_get_anon_vma(struct page *page); /* bitflags for do_page_add_anon_rmap() */ #define RMAP_EXCLUSIVE 0x01 #define RMAP_COMPOUND 0x02 /* * rmap interfaces called when adding or removing pte of page */ void page_move_anon_rmap(struct page *, struct vm_area_struct *); void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long, bool); void do_page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long, int); void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long, bool); void page_add_file_rmap(struct page *, bool); void page_remove_rmap(struct page *, bool); void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); static inline void page_dup_rmap(struct page *page, bool compound) { atomic_inc(compound ? compound_mapcount_ptr(page) : &page->_mapcount); } /* * Called from mm/vmscan.c to handle paging out */ int page_referenced(struct page *, int is_locked, struct mem_cgroup *memcg, unsigned long *vm_flags); bool try_to_unmap(struct page *, enum ttu_flags flags); /* Avoid racy checks */ #define PVMW_SYNC (1 << 0) /* Look for migarion entries rather than present PTEs */ #define PVMW_MIGRATION (1 << 1) struct page_vma_mapped_walk { struct page *page; struct vm_area_struct *vma; unsigned long address; pmd_t *pmd; pte_t *pte; spinlock_t *ptl; unsigned int flags; }; static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw) { /* HugeTLB pte is set to the relevant page table entry without pte_mapped. */ if (pvmw->pte && !PageHuge(pvmw->page)) pte_unmap(pvmw->pte); if (pvmw->ptl) spin_unlock(pvmw->ptl); } bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw); /* * Used by swapoff to help locate where page is expected in vma. */ unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); /* * Cleans the PTEs of shared mappings. * (and since clean PTEs should also be readonly, write protects them too) * * returns the number of cleaned PTEs. */ int page_mkclean(struct page *); /* * called in munlock()/munmap() path to check for other vmas holding * the page mlocked. */ void try_to_munlock(struct page *); void remove_migration_ptes(struct page *old, struct page *new, bool locked); /* * Called by memory-failure.c to kill processes. */ struct anon_vma *page_lock_anon_vma_read(struct page *page); void page_unlock_anon_vma_read(struct anon_vma *anon_vma); int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma); /* * rmap_walk_control: To control rmap traversing for specific needs * * arg: passed to rmap_one() and invalid_vma() * rmap_one: executed on each vma where page is mapped * done: for checking traversing termination condition * anon_lock: for getting anon_lock by optimized way rather than default * invalid_vma: for skipping uninterested vma */ struct rmap_walk_control { void *arg; /* * Return false if page table scanning in rmap_walk should be stopped. * Otherwise, return true. */ bool (*rmap_one)(struct page *page, struct vm_area_struct *vma, unsigned long addr, void *arg); int (*done)(struct page *page); struct anon_vma *(*anon_lock)(struct page *page); bool (*invalid_vma)(struct vm_area_struct *vma, void *arg); }; void rmap_walk(struct page *page, struct rmap_walk_control *rwc); void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc); #else /* !CONFIG_MMU */ #define anon_vma_init() do {} while (0) #define anon_vma_prepare(vma) (0) #define anon_vma_link(vma) do {} while (0) static inline int page_referenced(struct page *page, int is_locked, struct mem_cgroup *memcg, unsigned long *vm_flags) { *vm_flags = 0; return 0; } #define try_to_unmap(page, refs) false static inline int page_mkclean(struct page *page) { return 0; } #endif /* CONFIG_MMU */ #endif /* _LINUX_RMAP_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 /* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef _LINUX_IO_URING_H #define _LINUX_IO_URING_H #include <linux/sched.h> #include <linux/xarray.h> struct io_identity { struct files_struct *files; struct mm_struct *mm; #ifdef CONFIG_BLK_CGROUP struct cgroup_subsys_state *blkcg_css; #endif const struct cred *creds; struct nsproxy *nsproxy; struct fs_struct *fs; unsigned long fsize; #ifdef CONFIG_AUDIT kuid_t loginuid; unsigned int sessionid; #endif refcount_t count; }; struct io_uring_task { /* submission side */ struct xarray xa; struct wait_queue_head wait; struct file *last; struct percpu_counter inflight; struct io_identity __identity; struct io_identity *identity; atomic_t in_idle; bool sqpoll; }; #if defined(CONFIG_IO_URING) struct sock *io_uring_get_socket(struct file *file); void __io_uring_task_cancel(void); void __io_uring_files_cancel(struct files_struct *files); void __io_uring_free(struct task_struct *tsk); static inline void io_uring_task_cancel(void) { if (current->io_uring && !xa_empty(&current->io_uring->xa)) __io_uring_task_cancel(); } static inline void io_uring_files_cancel(struct files_struct *files) { if (current->io_uring && !xa_empty(&current->io_uring->xa)) __io_uring_files_cancel(files); } static inline void io_uring_free(struct task_struct *tsk) { if (tsk->io_uring) __io_uring_free(tsk); } #else static inline struct sock *io_uring_get_socket(struct file *file) { return NULL; } static inline void io_uring_task_cancel(void) { } static inline void io_uring_files_cancel(struct files_struct *files) { } static inline void io_uring_free(struct task_struct *tsk) { } #endif #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 /* SPDX-License-Identifier: GPL-2.0 */ /* Based on net/wireless/trace.h */ #undef TRACE_SYSTEM #define TRACE_SYSTEM cfg802154 #if !defined(__RDEV_CFG802154_OPS_TRACE) || defined(TRACE_HEADER_MULTI_READ) #define __RDEV_CFG802154_OPS_TRACE #include <linux/tracepoint.h> #include <net/cfg802154.h> #define MAXNAME 32 #define WPAN_PHY_ENTRY __array(char, wpan_phy_name, MAXNAME) #define WPAN_PHY_ASSIGN strlcpy(__entry->wpan_phy_name, \ wpan_phy_name(wpan_phy), \ MAXNAME) #define WPAN_PHY_PR_FMT "%s" #define WPAN_PHY_PR_ARG __entry->wpan_phy_name #define WPAN_DEV_ENTRY __field(u32, identifier) #define WPAN_DEV_ASSIGN (__entry->identifier) = (!IS_ERR_OR_NULL(wpan_dev) \ ? wpan_dev->identifier : 0) #define WPAN_DEV_PR_FMT "wpan_dev(%u)" #define WPAN_DEV_PR_ARG (__entry->identifier) #define WPAN_CCA_ENTRY __field(enum nl802154_cca_modes, cca_mode) \ __field(enum nl802154_cca_opts, cca_opt) #define WPAN_CCA_ASSIGN \ do { \ (__entry->cca_mode) = cca->mode; \ (__entry->cca_opt) = cca->opt; \ } while (0) #define WPAN_CCA_PR_FMT "cca_mode: %d, cca_opt: %d" #define WPAN_CCA_PR_ARG __entry->cca_mode, __entry->cca_opt #define BOOL_TO_STR(bo) (bo) ? "true" : "false" /************************************************************* * rdev->ops traces * *************************************************************/ DECLARE_EVENT_CLASS(wpan_phy_only_evt, TP_PROTO(struct wpan_phy *wpan_phy), TP_ARGS(wpan_phy), TP_STRUCT__entry( WPAN_PHY_ENTRY ), TP_fast_assign( WPAN_PHY_ASSIGN; ), TP_printk(WPAN_PHY_PR_FMT, WPAN_PHY_PR_ARG) ); DEFINE_EVENT(wpan_phy_only_evt, 802154_rdev_suspend, TP_PROTO(struct wpan_phy *wpan_phy), TP_ARGS(wpan_phy) ); DEFINE_EVENT(wpan_phy_only_evt, 802154_rdev_resume, TP_PROTO(struct wpan_phy *wpan_phy), TP_ARGS(wpan_phy) ); TRACE_EVENT(802154_rdev_add_virtual_intf, TP_PROTO(struct wpan_phy *wpan_phy, char *name, enum nl802154_iftype type, __le64 extended_addr), TP_ARGS(wpan_phy, name, type, extended_addr), TP_STRUCT__entry( WPAN_PHY_ENTRY __string(vir_intf_name, name ? name : "<noname>") __field(enum nl802154_iftype, type) __field(__le64, extended_addr) ), TP_fast_assign( WPAN_PHY_ASSIGN; __assign_str(vir_intf_name, name ? name : "<noname>"); __entry->type = type; __entry->extended_addr = extended_addr; ), TP_printk(WPAN_PHY_PR_FMT ", virtual intf name: %s, type: %d, extended addr: 0x%llx", WPAN_PHY_PR_ARG, __get_str(vir_intf_name), __entry->type, __le64_to_cpu(__entry->extended_addr)) ); TRACE_EVENT(802154_rdev_del_virtual_intf, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev), TP_ARGS(wpan_phy, wpan_dev), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT, WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG) ); TRACE_EVENT(802154_rdev_set_channel, TP_PROTO(struct wpan_phy *wpan_phy, u8 page, u8 channel), TP_ARGS(wpan_phy, page, channel), TP_STRUCT__entry( WPAN_PHY_ENTRY __field(u8, page) __field(u8, channel) ), TP_fast_assign( WPAN_PHY_ASSIGN; __entry->page = page; __entry->channel = channel; ), TP_printk(WPAN_PHY_PR_FMT ", page: %d, channel: %d", WPAN_PHY_PR_ARG, __entry->page, __entry->channel) ); TRACE_EVENT(802154_rdev_set_tx_power, TP_PROTO(struct wpan_phy *wpan_phy, s32 power), TP_ARGS(wpan_phy, power), TP_STRUCT__entry( WPAN_PHY_ENTRY __field(s32, power) ), TP_fast_assign( WPAN_PHY_ASSIGN; __entry->power = power; ), TP_printk(WPAN_PHY_PR_FMT ", mbm: %d", WPAN_PHY_PR_ARG, __entry->power) ); TRACE_EVENT(802154_rdev_set_cca_mode, TP_PROTO(struct wpan_phy *wpan_phy, const struct wpan_phy_cca *cca), TP_ARGS(wpan_phy, cca), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_CCA_ENTRY ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_CCA_ASSIGN; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_CCA_PR_FMT, WPAN_PHY_PR_ARG, WPAN_CCA_PR_ARG) ); TRACE_EVENT(802154_rdev_set_cca_ed_level, TP_PROTO(struct wpan_phy *wpan_phy, s32 ed_level), TP_ARGS(wpan_phy, ed_level), TP_STRUCT__entry( WPAN_PHY_ENTRY __field(s32, ed_level) ), TP_fast_assign( WPAN_PHY_ASSIGN; __entry->ed_level = ed_level; ), TP_printk(WPAN_PHY_PR_FMT ", ed level: %d", WPAN_PHY_PR_ARG, __entry->ed_level) ); DECLARE_EVENT_CLASS(802154_le16_template, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, __le16 le16arg), TP_ARGS(wpan_phy, wpan_dev, le16arg), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(__le16, le16arg) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->le16arg = le16arg; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", pan id: 0x%04x", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __le16_to_cpu(__entry->le16arg)) ); DEFINE_EVENT(802154_le16_template, 802154_rdev_set_pan_id, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, __le16 le16arg), TP_ARGS(wpan_phy, wpan_dev, le16arg) ); DEFINE_EVENT_PRINT(802154_le16_template, 802154_rdev_set_short_addr, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, __le16 le16arg), TP_ARGS(wpan_phy, wpan_dev, le16arg), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", short addr: 0x%04x", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __le16_to_cpu(__entry->le16arg)) ); TRACE_EVENT(802154_rdev_set_backoff_exponent, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, u8 min_be, u8 max_be), TP_ARGS(wpan_phy, wpan_dev, min_be, max_be), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(u8, min_be) __field(u8, max_be) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->min_be = min_be; __entry->max_be = max_be; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", min be: %d, max be: %d", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __entry->min_be, __entry->max_be) ); TRACE_EVENT(802154_rdev_set_csma_backoffs, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, u8 max_csma_backoffs), TP_ARGS(wpan_phy, wpan_dev, max_csma_backoffs), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(u8, max_csma_backoffs) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->max_csma_backoffs = max_csma_backoffs; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", max csma backoffs: %d", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __entry->max_csma_backoffs) ); TRACE_EVENT(802154_rdev_set_max_frame_retries, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, s8 max_frame_retries), TP_ARGS(wpan_phy, wpan_dev, max_frame_retries), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(s8, max_frame_retries) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->max_frame_retries = max_frame_retries; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", max frame retries: %d", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __entry->max_frame_retries) ); TRACE_EVENT(802154_rdev_set_lbt_mode, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, bool mode), TP_ARGS(wpan_phy, wpan_dev, mode), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(bool, mode) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->mode = mode; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", lbt mode: %s", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, BOOL_TO_STR(__entry->mode)) ); TRACE_EVENT(802154_rdev_set_ackreq_default, TP_PROTO(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, bool ackreq), TP_ARGS(wpan_phy, wpan_dev, ackreq), TP_STRUCT__entry( WPAN_PHY_ENTRY WPAN_DEV_ENTRY __field(bool, ackreq) ), TP_fast_assign( WPAN_PHY_ASSIGN; WPAN_DEV_ASSIGN; __entry->ackreq = ackreq; ), TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", ackreq default: %s", WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, BOOL_TO_STR(__entry->ackreq)) ); TRACE_EVENT(802154_rdev_return_int, TP_PROTO(struct wpan_phy *wpan_phy, int ret), TP_ARGS(wpan_phy, ret), TP_STRUCT__entry( WPAN_PHY_ENTRY __field(int, ret) ), TP_fast_assign( WPAN_PHY_ASSIGN; __entry->ret = ret; ), TP_printk(WPAN_PHY_PR_FMT ", returned: %d", WPAN_PHY_PR_ARG, __entry->ret) ); #endif /* !__RDEV_CFG802154_OPS_TRACE || TRACE_HEADER_MULTI_READ */ #undef TRACE_INCLUDE_PATH #define TRACE_INCLUDE_PATH . #undef TRACE_INCLUDE_FILE #define TRACE_INCLUDE_FILE trace #include <trace/define_trace.h>
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 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __LINUX_COMPLETION_H #define __LINUX_COMPLETION_H /* * (C) Copyright 2001 Linus Torvalds * * Atomic wait-for-completion handler data structures. * See kernel/sched/completion.c for details. */ #include <linux/swait.h> /* * struct completion - structure used to maintain state for a "completion" * * This is the opaque structure used to maintain the state for a "completion". * Completions currently use a FIFO to queue threads that have to wait for * the "completion" event. * * See also: complete(), wait_for_completion() (and friends _timeout, * _interruptible, _interruptible_timeout, and _killable), init_completion(), * reinit_completion(), and macros DECLARE_COMPLETION(), * DECLARE_COMPLETION_ONSTACK(). */ struct completion { unsigned int done; struct swait_queue_head wait; }; #define init_completion_map(x, m) __init_completion(x) #define init_completion(x) __init_completion(x) static inline void complete_acquire(struct completion *x) {} static inline void complete_release(struct completion *x) {} #define COMPLETION_INITIALIZER(work) \ { 0, __SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) } #define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \ (*({ init_completion_map(&(work), &(map)); &(work); })) #define COMPLETION_INITIALIZER_ONSTACK(work) \ (*({ init_completion(&work); &work; })) /** * DECLARE_COMPLETION - declare and initialize a completion structure * @work: identifier for the completion structure * * This macro declares and initializes a completion structure. Generally used * for static declarations. You should use the _ONSTACK variant for automatic * variables. */ #define DECLARE_COMPLETION(work) \ struct completion work = COMPLETION_INITIALIZER(work) /* * Lockdep needs to run a non-constant initializer for on-stack * completions - so we use the _ONSTACK() variant for those that * are on the kernel stack: */ /** * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure * @work: identifier for the completion structure * * This macro declares and initializes a completion structure on the kernel * stack. */ #ifdef CONFIG_LOCKDEP # define DECLARE_COMPLETION_ONSTACK(work) \ struct completion work = COMPLETION_INITIALIZER_ONSTACK(work) # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \ struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) #else # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work) # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work) #endif /** * init_completion - Initialize a dynamically allocated completion * @x: pointer to completion structure that is to be initialized * * This inline function will initialize a dynamically created completion * structure. */ static inline void __init_completion(struct completion *x) { x->done = 0; init_swait_queue_head(&x->wait); } /** * reinit_completion - reinitialize a completion structure * @x: pointer to completion structure that is to be reinitialized * * This inline function should be used to reinitialize a completion structure so it can * be reused. This is especially important after complete_all() is used. */ static inline void reinit_completion(struct completion *x) { x->done = 0; } extern void wait_for_completion(struct completion *); extern void wait_for_completion_io(struct completion *); extern int wait_for_completion_interruptible(struct completion *x); extern int wait_for_completion_killable(struct completion *x); extern unsigned long wait_for_completion_timeout(struct completion *x, unsigned long timeout); extern unsigned long wait_for_completion_io_timeout(struct completion *x, unsigned long timeout); extern long wait_for_completion_interruptible_timeout( struct completion *x, unsigned long timeout); extern long wait_for_completion_killable_timeout( struct completion *x, unsigned long timeout); extern bool try_wait_for_completion(struct completion *x); extern bool completion_done(struct completion *x); extern void complete(struct completion *); extern void complete_all(struct completion *); #endif
1 1 1 1 1 1 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 // SPDX-License-Identifier: GPL-2.0 /* * Implementation of the multi-level security (MLS) policy. * * Author : Stephen Smalley, <sds@tycho.nsa.gov> */ /* * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> * * Support for enhanced MLS infrastructure. * * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. */ /* * Updated: Hewlett-Packard <paul@paul-moore.com> * * Added support to import/export the MLS label from NetLabel * * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 */ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> #include <net/netlabel.h> #include "sidtab.h" #include "mls.h" #include "policydb.h" #include "services.h" /* * Return the length in bytes for the MLS fields of the * security context string representation of `context'. */ int mls_compute_context_len(struct policydb *p, struct context *context) { int i, l, len, head, prev; char *nm; struct ebitmap *e; struct ebitmap_node *node; if (!p->mls_enabled) return 0; len = 1; /* for the beginning ":" */ for (l = 0; l < 2; l++) { int index_sens = context->range.level[l].sens; len += strlen(sym_name(p, SYM_LEVELS, index_sens - 1)); /* categories */ head = -2; prev = -2; e = &context->range.level[l].cat; ebitmap_for_each_positive_bit(e, node, i) { if (i - prev > 1) { /* one or more negative bits are skipped */ if (head != prev) { nm = sym_name(p, SYM_CATS, prev); len += strlen(nm) + 1; } nm = sym_name(p, SYM_CATS, i); len += strlen(nm) + 1; head = i; } prev = i; } if (prev != head) { nm = sym_name(p, SYM_CATS, prev); len += strlen(nm) + 1; } if (l == 0) { if (mls_level_eq(&context->range.level[0], &context->range.level[1])) break; else len++; } } return len; } /* * Write the security context string representation of * the MLS fields of `context' into the string `*scontext'. * Update `*scontext' to point to the end of the MLS fields. */ void mls_sid_to_context(struct policydb *p, struct context *context, char **scontext) { char *scontextp, *nm; int i, l, head, prev; struct ebitmap *e; struct ebitmap_node *node; if (!p->mls_enabled) return; scontextp = *scontext; *scontextp = ':'; scontextp++; for (l = 0; l < 2; l++) { strcpy(scontextp, sym_name(p, SYM_LEVELS, context->range.level[l].sens - 1)); scontextp += strlen(scontextp); /* categories */ head = -2; prev = -2; e = &context->range.level[l].cat; ebitmap_for_each_positive_bit(e, node, i) { if (i - prev > 1) { /* one or more negative bits are skipped */ if (prev != head) { if (prev - head > 1) *scontextp++ = '.'; else *scontextp++ = ','; nm = sym_name(p, SYM_CATS, prev); strcpy(scontextp, nm); scontextp += strlen(nm); } if (prev < 0) *scontextp++ = ':'; else *scontextp++ = ','; nm = sym_name(p, SYM_CATS, i); strcpy(scontextp, nm); scontextp += strlen(nm); head = i; } prev = i; } if (prev != head) { if (prev - head > 1) *scontextp++ = '.'; else *scontextp++ = ','; nm = sym_name(p, SYM_CATS, prev); strcpy(scontextp, nm); scontextp += strlen(nm); } if (l == 0) { if (mls_level_eq(&context->range.level[0], &context->range.level[1])) break; else *scontextp++ = '-'; } } *scontext = scontextp; return; } int mls_level_isvalid(struct policydb *p, struct mls_level *l) { struct level_datum *levdatum; if (!l->sens || l->sens > p->p_levels.nprim) return 0; levdatum = symtab_search(&p->p_levels, sym_name(p, SYM_LEVELS, l->sens - 1)); if (!levdatum) return 0; /* * Return 1 iff all the bits set in l->cat are also be set in * levdatum->level->cat and no bit in l->cat is larger than * p->p_cats.nprim. */ return ebitmap_contains(&levdatum->level->cat, &l->cat, p->p_cats.nprim); } int mls_range_isvalid(struct policydb *p, struct mls_range *r) { return (mls_level_isvalid(p, &r->level[0]) && mls_level_isvalid(p, &r->level[1]) && mls_level_dom(&r->level[1], &r->level[0])); } /* * Return 1 if the MLS fields in the security context * structure `c' are valid. Return 0 otherwise. */ int mls_context_isvalid(struct policydb *p, struct context *c) { struct user_datum *usrdatum; if (!p->mls_enabled) return 1; if (!mls_range_isvalid(p, &c->range)) return 0; if (c->role == OBJECT_R_VAL) return 1; /* * User must be authorized for the MLS range. */ if (!c->user || c->user > p->p_users.nprim) return 0; usrdatum = p->user_val_to_struct[c->user - 1]; if (!mls_range_contains(usrdatum->range, c->range)) return 0; /* user may not be associated with range */ return 1; } /* * Set the MLS fields in the security context structure * `context' based on the string representation in * the string `scontext'. * * This function modifies the string in place, inserting * NULL characters to terminate the MLS fields. * * If a def_sid is provided and no MLS field is present, * copy the MLS field of the associated default context. * Used for upgraded to MLS systems where objects may lack * MLS fields. * * Policy read-lock must be held for sidtab lookup. * */ int mls_context_to_sid(struct policydb *pol, char oldc, char *scontext, struct context *context, struct sidtab *s, u32 def_sid) { char *sensitivity, *cur_cat, *next_cat, *rngptr; struct level_datum *levdatum; struct cat_datum *catdatum, *rngdatum; int l, rc, i; char *rangep[2]; if (!pol->mls_enabled) { /* * With no MLS, only return -EINVAL if there is a MLS field * and it did not come from an xattr. */ if (oldc && def_sid == SECSID_NULL) return -EINVAL; return 0; } /* * No MLS component to the security context, try and map to * default if provided. */ if (!oldc) { struct context *defcon; if (def_sid == SECSID_NULL) return -EINVAL; defcon = sidtab_search(s, def_sid); if (!defcon) return -EINVAL; return mls_context_cpy(context, defcon); } /* * If we're dealing with a range, figure out where the two parts * of the range begin. */ rangep[0] = scontext; rangep[1] = strchr(scontext, '-'); if (rangep[1]) { rangep[1][0] = '\0'; rangep[1]++; } /* For each part of the range: */ for (l = 0; l < 2; l++) { /* Split sensitivity and category set. */ sensitivity = rangep[l]; if (sensitivity == NULL) break; next_cat = strchr(sensitivity, ':'); if (next_cat) *(next_cat++) = '\0'; /* Parse sensitivity. */ levdatum = symtab_search(&pol->p_levels, sensitivity); if (!levdatum) return -EINVAL; context->range.level[l].sens = levdatum->level->sens; /* Extract category set. */ while (next_cat != NULL) { cur_cat = next_cat; next_cat = strchr(next_cat, ','); if (next_cat != NULL) *(next_cat++) = '\0'; /* Separate into range if exists */ rngptr = strchr(cur_cat, '.'); if (rngptr != NULL) { /* Remove '.' */ *rngptr++ = '\0'; } catdatum = symtab_search(&pol->p_cats, cur_cat); if (!catdatum) return -EINVAL; rc = ebitmap_set_bit(&context->range.level[l].cat, catdatum->value - 1, 1); if (rc) return rc; /* If range, set all categories in range */ if (rngptr == NULL) continue; rngdatum = symtab_search(&pol->p_cats, rngptr); if (!rngdatum) return -EINVAL; if (catdatum->value >= rngdatum->value) return -EINVAL; for (i = catdatum->value; i < rngdatum->value; i++) { rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1); if (rc) return rc; } } } /* If we didn't see a '-', the range start is also the range end. */ if (rangep[1] == NULL) { context->range.level[1].sens = context->range.level[0].sens; rc = ebitmap_cpy(&context->range.level[1].cat, &context->range.level[0].cat); if (rc) return rc; } return 0; } /* * Set the MLS fields in the security context structure * `context' based on the string representation in * the string `str'. This function will allocate temporary memory with the * given constraints of gfp_mask. */ int mls_from_string(struct policydb *p, char *str, struct context *context, gfp_t gfp_mask) { char *tmpstr; int rc; if (!p->mls_enabled) return -EINVAL; tmpstr = kstrdup(str, gfp_mask); if (!tmpstr) { rc = -ENOMEM; } else { rc = mls_context_to_sid(p, ':', tmpstr, context, NULL, SECSID_NULL); kfree(tmpstr); } return rc; } /* * Copies the MLS range `range' into `context'. */ int mls_range_set(struct context *context, struct mls_range *range) { int l, rc = 0; /* Copy the MLS range into the context */ for (l = 0; l < 2; l++) { context->range.level[l].sens = range->level[l].sens; rc = ebitmap_cpy(&context->range.level[l].cat, &range->level[l].cat); if (rc) break; } return rc; } int mls_setup_user_range(struct policydb *p, struct context *fromcon, struct user_datum *user, struct context *usercon) { if (p->mls_enabled) { struct mls_level *fromcon_sen = &(fromcon->range.level[0]); struct mls_level *fromcon_clr = &(fromcon->range.level[1]); struct mls_level *user_low = &(user->range.level[0]); struct mls_level *user_clr = &(user->range.level[1]); struct mls_level *user_def = &(user->dfltlevel); struct mls_level *usercon_sen = &(usercon->range.level[0]); struct mls_level *usercon_clr = &(usercon->range.level[1]); /* Honor the user's default level if we can */ if (mls_level_between(user_def, fromcon_sen, fromcon_clr)) *usercon_sen = *user_def; else if (mls_level_between(fromcon_sen, user_def, user_clr)) *usercon_sen = *fromcon_sen; else if (mls_level_between(fromcon_clr, user_low, user_def)) *usercon_sen = *user_low; else return -EINVAL; /* Lower the clearance of available contexts if the clearance of "fromcon" is lower than that of the user's default clearance (but only if the "fromcon" clearance dominates the user's computed sensitivity level) */ if (mls_level_dom(user_clr, fromcon_clr)) *usercon_clr = *fromcon_clr; else if (mls_level_dom(fromcon_clr, user_clr)) *usercon_clr = *user_clr; else return -EINVAL; } return 0; } /* * Convert the MLS fields in the security context * structure `oldc' from the values specified in the * policy `oldp' to the values specified in the policy `newp', * storing the resulting context in `newc'. */ int mls_convert_context(struct policydb *oldp, struct policydb *newp, struct context *oldc, struct context *newc) { struct level_datum *levdatum; struct cat_datum *catdatum; struct ebitmap_node *node; int l, i; if (!oldp->mls_enabled || !newp->mls_enabled) return 0; for (l = 0; l < 2; l++) { char *name = sym_name(oldp, SYM_LEVELS, oldc->range.level[l].sens - 1); levdatum = symtab_search(&newp->p_levels, name); if (!levdatum) return -EINVAL; newc->range.level[l].sens = levdatum->level->sens; ebitmap_for_each_positive_bit(&oldc->range.level[l].cat, node, i) { int rc; catdatum = symtab_search(&newp->p_cats, sym_name(oldp, SYM_CATS, i)); if (!catdatum) return -EINVAL; rc = ebitmap_set_bit(&newc->range.level[l].cat, catdatum->value - 1, 1); if (rc) return rc; } } return 0; } int mls_compute_sid(struct policydb *p, struct context *scontext, struct context *tcontext, u16 tclass, u32 specified, struct context *newcontext, bool sock) { struct range_trans rtr; struct mls_range *r; struct class_datum *cladatum; int default_range = 0; if (!p->mls_enabled) return 0; switch (specified) { case AVTAB_TRANSITION: /* Look for a range transition rule. */ rtr.source_type = scontext->type; rtr.target_type = tcontext->type; rtr.target_class = tclass; r = policydb_rangetr_search(p, &rtr); if (r) return mls_range_set(newcontext, r); if (tclass && tclass <= p->p_classes.nprim) { cladatum = p->class_val_to_struct[tclass - 1]; if (cladatum) default_range = cladatum->default_range; } switch (default_range) { case DEFAULT_SOURCE_LOW: return mls_context_cpy_low(newcontext, scontext); case DEFAULT_SOURCE_HIGH: return mls_context_cpy_high(newcontext, scontext); case DEFAULT_SOURCE_LOW_HIGH: return mls_context_cpy(newcontext, scontext); case DEFAULT_TARGET_LOW: return mls_context_cpy_low(newcontext, tcontext); case DEFAULT_TARGET_HIGH: return mls_context_cpy_high(newcontext, tcontext); case DEFAULT_TARGET_LOW_HIGH: return mls_context_cpy(newcontext, tcontext); case DEFAULT_GLBLUB: return mls_context_glblub(newcontext, scontext, tcontext); } fallthrough; case AVTAB_CHANGE: if ((tclass == p->process_class) || sock) /* Use the process MLS attributes. */ return mls_context_cpy(newcontext, scontext); else /* Use the process effective MLS attributes. */ return mls_context_cpy_low(newcontext, scontext); case AVTAB_MEMBER: /* Use the process effective MLS attributes. */ return mls_context_cpy_low(newcontext, scontext); } return -EINVAL; } #ifdef CONFIG_NETLABEL /** * mls_export_netlbl_lvl - Export the MLS sensitivity levels to NetLabel * @context: the security context * @secattr: the NetLabel security attributes * * Description: * Given the security context copy the low MLS sensitivity level into the * NetLabel MLS sensitivity level field. * */ void mls_export_netlbl_lvl(struct policydb *p, struct context *context, struct netlbl_lsm_secattr *secattr) { if (!p->mls_enabled) return; secattr->attr.mls.lvl = context->range.level[0].sens - 1; secattr->flags |= NETLBL_SECATTR_MLS_LVL; } /** * mls_import_netlbl_lvl - Import the NetLabel MLS sensitivity levels * @context: the security context * @secattr: the NetLabel security attributes * * Description: * Given the security context and the NetLabel security attributes, copy the * NetLabel MLS sensitivity level into the context. * */ void mls_import_netlbl_lvl(struct policydb *p, struct context *context, struct netlbl_lsm_secattr *secattr) { if (!p->mls_enabled) return; context->range.level[0].sens = secattr->attr.mls.lvl + 1; context->range.level[1].sens = context->range.level[0].sens; } /** * mls_export_netlbl_cat - Export the MLS categories to NetLabel * @context: the security context * @secattr: the NetLabel security attributes * * Description: * Given the security context copy the low MLS categories into the NetLabel * MLS category field. Returns zero on success, negative values on failure. * */ int mls_export_netlbl_cat(struct policydb *p, struct context *context, struct netlbl_lsm_secattr *secattr) { int rc; if (!p->mls_enabled) return 0; rc = ebitmap_netlbl_export(&context->range.level[0].cat, &secattr->attr.mls.cat); if (rc == 0 && secattr->attr.mls.cat != NULL) secattr->flags |= NETLBL_SECATTR_MLS_CAT; return rc; } /** * mls_import_netlbl_cat - Import the MLS categories from NetLabel * @context: the security context * @secattr: the NetLabel security attributes * * Description: * Copy the NetLabel security attributes into the SELinux context; since the * NetLabel security attribute only contains a single MLS category use it for * both the low and high categories of the context. Returns zero on success, * negative values on failure. * */ int mls_import_netlbl_cat(struct policydb *p, struct context *context, struct netlbl_lsm_secattr *secattr) { int rc; if (!p->mls_enabled) return 0; rc = ebitmap_netlbl_import(&context->range.level[0].cat, secattr->attr.mls.cat); if (rc) goto import_netlbl_cat_failure; memcpy(&context->range.level[1].cat, &context->range.level[0].cat, sizeof(context->range.level[0].cat)); return 0; import_netlbl_cat_failure: ebitmap_destroy(&context->range.level[0].cat); return rc; } #endif /* CONFIG_NETLABEL */
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 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_SCATTERLIST_H #define _LINUX_SCATTERLIST_H #include <linux/string.h> #include <linux/types.h> #include <linux/bug.h> #include <linux/mm.h> #include <asm/io.h> struct scatterlist { unsigned long page_link; unsigned int offset; unsigned int length; dma_addr_t dma_address; #ifdef CONFIG_NEED_SG_DMA_LENGTH unsigned int dma_length; #endif }; /* * Since the above length field is an unsigned int, below we define the maximum * length in bytes that can be stored in one scatterlist entry. */ #define SCATTERLIST_MAX_SEGMENT (UINT_MAX & PAGE_MASK) /* * These macros should be used after a dma_map_sg call has been done * to get bus addresses of each of the SG entries and their lengths. * You should only work with the number of sg entries dma_map_sg * returns, or alternatively stop on the first sg_dma_len(sg) which * is 0. */ #define sg_dma_address(sg) ((sg)->dma_address) #ifdef CONFIG_NEED_SG_DMA_LENGTH #define sg_dma_len(sg) ((sg)->dma_length) #else #define sg_dma_len(sg) ((sg)->length) #endif struct sg_table { struct scatterlist *sgl; /* the list */ unsigned int nents; /* number of mapped entries */ unsigned int orig_nents; /* original size of list */ }; /* * Notes on SG table design. * * We use the unsigned long page_link field in the scatterlist struct to place * the page pointer AND encode information about the sg table as well. The two * lower bits are reserved for this information. * * If bit 0 is set, then the page_link contains a pointer to the next sg * table list. Otherwise the next entry is at sg + 1. * * If bit 1 is set, then this sg entry is the last element in a list. * * See sg_next(). * */ #define SG_CHAIN 0x01UL #define SG_END 0x02UL /* * We overload the LSB of the page pointer to indicate whether it's * a valid sg entry, or whether it points to the start of a new scatterlist. * Those low bits are there for everyone! (thanks mason :-) */ #define sg_is_chain(sg) ((sg)->page_link & SG_CHAIN) #define sg_is_last(sg) ((sg)->page_link & SG_END) #define sg_chain_ptr(sg) \ ((struct scatterlist *) ((sg)->page_link & ~(SG_CHAIN | SG_END))) /** * sg_assign_page - Assign a given page to an SG entry * @sg: SG entry * @page: The page * * Description: * Assign page to sg entry. Also see sg_set_page(), the most commonly used * variant. * **/ static inline void sg_assign_page(struct scatterlist *sg, struct page *page) { unsigned long page_link = sg->page_link & (SG_CHAIN | SG_END); /* * In order for the low bit stealing approach to work, pages * must be aligned at a 32-bit boundary as a minimum. */ BUG_ON((unsigned long) page & (SG_CHAIN | SG_END)); #ifdef CONFIG_DEBUG_SG BUG_ON(sg_is_chain(sg)); #endif sg->page_link = page_link | (unsigned long) page; } /** * sg_set_page - Set sg entry to point at given page * @sg: SG entry * @page: The page * @len: Length of data * @offset: Offset into page * * Description: * Use this function to set an sg entry pointing at a page, never assign * the page directly. We encode sg table information in the lower bits * of the page pointer. See sg_page() for looking up the page belonging * to an sg entry. * **/ static inline void sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len, unsigned int offset) { sg_assign_page(sg, page); sg->offset = offset; sg->length = len; } static inline struct page *sg_page(struct scatterlist *sg) { #ifdef CONFIG_DEBUG_SG BUG_ON(sg_is_chain(sg)); #endif return (struct page *)((sg)->page_link & ~(SG_CHAIN | SG_END)); } /** * sg_set_buf - Set sg entry to point at given data * @sg: SG entry * @buf: Data * @buflen: Data length * **/ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) { #ifdef CONFIG_DEBUG_SG BUG_ON(!virt_addr_valid(buf)); #endif sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf)); } /* * Loop over each sg element, following the pointer to a new list if necessary */ #define for_each_sg(sglist, sg, nr, __i) \ for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg)) /* * Loop over each sg element in the given sg_table object. */ #define for_each_sgtable_sg(sgt, sg, i) \ for_each_sg((sgt)->sgl, sg, (sgt)->orig_nents, i) /* * Loop over each sg element in the given *DMA mapped* sg_table object. * Please use sg_dma_address(sg) and sg_dma_len(sg) to extract DMA addresses * of the each element. */ #define for_each_sgtable_dma_sg(sgt, sg, i) \ for_each_sg((sgt)->sgl, sg, (sgt)->nents, i) static inline void __sg_chain(struct scatterlist *chain_sg, struct scatterlist *sgl) { /* * offset and length are unused for chain entry. Clear them. */ chain_sg->offset = 0; chain_sg->length = 0; /* * Set lowest bit to indicate a link pointer, and make sure to clear * the termination bit if it happens to be set. */ chain_sg->page_link = ((unsigned long) sgl | SG_CHAIN) & ~SG_END; } /** * sg_chain - Chain two sglists together * @prv: First scatterlist * @prv_nents: Number of entries in prv * @sgl: Second scatterlist * * Description: * Links @prv@ and @sgl@ together, to form a longer scatterlist. * **/ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, struct scatterlist *sgl) { __sg_chain(&prv[prv_nents - 1], sgl); } /** * sg_mark_end - Mark the end of the scatterlist * @sg: SG entryScatterlist * * Description: * Marks the passed in sg entry as the termination point for the sg * table. A call to sg_next() on this entry will return NULL. * **/ static inline void sg_mark_end(struct scatterlist *sg) { /* * Set termination bit, clear potential chain bit */ sg->page_link |= SG_END; sg->page_link &= ~SG_CHAIN; } /** * sg_unmark_end - Undo setting the end of the scatterlist * @sg: SG entryScatterlist * * Description: * Removes the termination marker from the given entry of the scatterlist. * **/ static inline void sg_unmark_end(struct scatterlist *sg) { sg->page_link &= ~SG_END; } /** * sg_phys - Return physical address of an sg entry * @sg: SG entry * * Description: * This calls page_to_phys() on the page in this sg entry, and adds the * sg offset. The caller must know that it is legal to call page_to_phys() * on the sg page. * **/ static inline dma_addr_t sg_phys(struct scatterlist *sg) { return page_to_phys(sg_page(sg)) + sg->offset; } /** * sg_virt - Return virtual address of an sg entry * @sg: SG entry * * Description: * This calls page_address() on the page in this sg entry, and adds the * sg offset. The caller must know that the sg page has a valid virtual * mapping. * **/ static inline void *sg_virt(struct scatterlist *sg) { return page_address(sg_page(sg)) + sg->offset; } /** * sg_init_marker - Initialize markers in sg table * @sgl: The SG table * @nents: Number of entries in table * **/ static inline void sg_init_marker(struct scatterlist *sgl, unsigned int nents) { sg_mark_end(&sgl[nents - 1]); } int sg_nents(struct scatterlist *sg); int sg_nents_for_len(struct scatterlist *sg, u64 len); struct scatterlist *sg_next(struct scatterlist *); struct scatterlist *sg_last(struct scatterlist *s, unsigned int); void sg_init_table(struct scatterlist *, unsigned int); void sg_init_one(struct scatterlist *, const void *, unsigned int); int sg_split(struct scatterlist *in, const int in_mapped_nents, const off_t skip, const int nb_splits, const size_t *split_sizes, struct scatterlist **out, int *out_mapped_nents, gfp_t gfp_mask); typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t); typedef void (sg_free_fn)(struct scatterlist *, unsigned int); void __sg_free_table(struct sg_table *, unsigned int, unsigned int, sg_free_fn *); void sg_free_table(struct sg_table *); int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *); int sg_alloc_table(struct sg_table *, unsigned int, gfp_t); struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int n_pages, unsigned int offset, unsigned long size, unsigned int max_segment, struct scatterlist *prv, unsigned int left_pages, gfp_t gfp_mask); int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int n_pages, unsigned int offset, unsigned long size, gfp_t gfp_mask); #ifdef CONFIG_SGL_ALLOC struct scatterlist *sgl_alloc_order(unsigned long long length, unsigned int order, bool chainable, gfp_t gfp, unsigned int *nent_p); struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp, unsigned int *nent_p); void sgl_free_n_order(struct scatterlist *sgl, int nents, int order); void sgl_free_order(struct scatterlist *sgl, int order); void sgl_free(struct scatterlist *sgl); #endif /* CONFIG_SGL_ALLOC */ size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen, off_t skip, bool to_buffer); size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, const void *buf, size_t buflen); size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen); size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, const void *buf, size_t buflen, off_t skip); size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen, off_t skip); size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents, size_t buflen, off_t skip); /* * Maximum number of entries that will be allocated in one piece, if * a list larger than this is required then chaining will be utilized. */ #define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist)) /* * The maximum number of SG segments that we will put inside a * scatterlist (unless chaining is used). Should ideally fit inside a * single page, to avoid a higher order allocation. We could define this * to SG_MAX_SINGLE_ALLOC to pack correctly at the highest order. The * minimum value is 32 */ #define SG_CHUNK_SIZE 128 /* * Like SG_CHUNK_SIZE, but for archs that have sg chaining. This limit * is totally arbitrary, a setting of 2048 will get you at least 8mb ios. */ #ifdef CONFIG_ARCH_NO_SG_CHAIN #define SG_MAX_SEGMENTS SG_CHUNK_SIZE #else #define SG_MAX_SEGMENTS 2048 #endif #ifdef CONFIG_SG_POOL void sg_free_table_chained(struct sg_table *table, unsigned nents_first_chunk); int sg_alloc_table_chained(struct sg_table *table, int nents, struct scatterlist *first_chunk, unsigned nents_first_chunk); #endif /* * sg page iterator * * Iterates over sg entries page-by-page. On each successful iteration, you * can call sg_page_iter_page(@piter) to get the current page. * @piter->sg will point to the sg holding this page and @piter->sg_pgoffset to * the page's page offset within the sg. The iteration will stop either when a * maximum number of sg entries was reached or a terminating sg * (sg_last(sg) == true) was reached. */ struct sg_page_iter { struct scatterlist *sg; /* sg holding the page */ unsigned int sg_pgoffset; /* page offset within the sg */ /* these are internal states, keep away */ unsigned int __nents; /* remaining sg entries */ int __pg_advance; /* nr pages to advance at the * next step */ }; /* * sg page iterator for DMA addresses * * This is the same as sg_page_iter however you can call * sg_page_iter_dma_address(@dma_iter) to get the page's DMA * address. sg_page_iter_page() cannot be called on this iterator. */ struct sg_dma_page_iter { struct sg_page_iter base; }; bool __sg_page_iter_next(struct sg_page_iter *piter); bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter); void __sg_page_iter_start(struct sg_page_iter *piter, struct scatterlist *sglist, unsigned int nents, unsigned long pgoffset); /** * sg_page_iter_page - get the current page held by the page iterator * @piter: page iterator holding the page */ static inline struct page *sg_page_iter_page(struct sg_page_iter *piter) { return nth_page(sg_page(piter->sg), piter->sg_pgoffset); } /** * sg_page_iter_dma_address - get the dma address of the current page held by * the page iterator. * @dma_iter: page iterator holding the page */ static inline dma_addr_t sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter) { return sg_dma_address(dma_iter->base.sg) + (dma_iter->base.sg_pgoffset << PAGE_SHIFT); } /** * for_each_sg_page - iterate over the pages of the given sg list * @sglist: sglist to iterate over * @piter: page iterator to hold current page, sg, sg_pgoffset * @nents: maximum number of sg entries to iterate over * @pgoffset: starting page offset (in pages) * * Callers may use sg_page_iter_page() to get each page pointer. * In each loop it operates on PAGE_SIZE unit. */ #define for_each_sg_page(sglist, piter, nents, pgoffset) \ for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \ __sg_page_iter_next(piter);) /** * for_each_sg_dma_page - iterate over the pages of the given sg list * @sglist: sglist to iterate over * @dma_iter: DMA page iterator to hold current page * @dma_nents: maximum number of sg entries to iterate over, this is the value * returned from dma_map_sg * @pgoffset: starting page offset (in pages) * * Callers may use sg_page_iter_dma_address() to get each page's DMA address. * In each loop it operates on PAGE_SIZE unit. */ #define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \ for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \ pgoffset); \ __sg_page_iter_dma_next(dma_iter);) /** * for_each_sgtable_page - iterate over all pages in the sg_table object * @sgt: sg_table object to iterate over * @piter: page iterator to hold current page * @pgoffset: starting page offset (in pages) * * Iterates over the all memory pages in the buffer described by * a scatterlist stored in the given sg_table object. * See also for_each_sg_page(). In each loop it operates on PAGE_SIZE unit. */ #define for_each_sgtable_page(sgt, piter, pgoffset) \ for_each_sg_page((sgt)->sgl, piter, (sgt)->orig_nents, pgoffset) /** * for_each_sgtable_dma_page - iterate over the DMA mapped sg_table object * @sgt: sg_table object to iterate over * @dma_iter: DMA page iterator to hold current page * @pgoffset: starting page offset (in pages) * * Iterates over the all DMA mapped pages in the buffer described by * a scatterlist stored in the given sg_table object. * See also for_each_sg_dma_page(). In each loop it operates on PAGE_SIZE * unit. */ #define for_each_sgtable_dma_page(sgt, dma_iter, pgoffset) \ for_each_sg_dma_page((sgt)->sgl, dma_iter, (sgt)->nents, pgoffset) /* * Mapping sg iterator * * Iterates over sg entries mapping page-by-page. On each successful * iteration, @miter->page points to the mapped page and * @miter->length bytes of data can be accessed at @miter->addr. As * long as an interation is enclosed between start and stop, the user * is free to choose control structure and when to stop. * * @miter->consumed is set to @miter->length on each iteration. It * can be adjusted if the user can't consume all the bytes in one go. * Also, a stopped iteration can be resumed by calling next on it. * This is useful when iteration needs to release all resources and * continue later (e.g. at the next interrupt). */ #define SG_MITER_ATOMIC (1 << 0) /* use kmap_atomic */ #define SG_MITER_TO_SG (1 << 1) /* flush back to phys on unmap */ #define SG_MITER_FROM_SG (1 << 2) /* nop */ struct sg_mapping_iter { /* the following three fields can be accessed directly */ struct page *page; /* currently mapped page */ void *addr; /* pointer to the mapped area */ size_t length; /* length of the mapped area */ size_t consumed; /* number of consumed bytes */ struct sg_page_iter piter; /* page iterator */ /* these are internal states, keep away */ unsigned int __offset; /* offset within page */ unsigned int __remaining; /* remaining bytes on page */ unsigned int __flags; }; void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl, unsigned int nents, unsigned int flags); bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset); bool sg_miter_next(struct sg_mapping_iter *miter); void sg_miter_stop(struct sg_mapping_iter *miter); #endif /* _LINUX_SCATTERLIST_H */
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 /* SPDX-License-Identifier: GPL-2.0 */ /* * Variant of atomic_t specialized for reference counts. * * The interface matches the atomic_t interface (to aid in porting) but only * provides the few functions one should use for reference counting. * * Saturation semantics * ==================== * * refcount_t differs from atomic_t in that the counter saturates at * REFCOUNT_SATURATED and will not move once there. This avoids wrapping the * counter and causing 'spurious' use-after-free issues. In order to avoid the * cost associated with introducing cmpxchg() loops into all of the saturating * operations, we temporarily allow the counter to take on an unchecked value * and then explicitly set it to REFCOUNT_SATURATED on detecting that underflow * or overflow has occurred. Although this is racy when multiple threads * access the refcount concurrently, by placing REFCOUNT_SATURATED roughly * equidistant from 0 and INT_MAX we minimise the scope for error: * * INT_MAX REFCOUNT_SATURATED UINT_MAX * 0 (0x7fff_ffff) (0xc000_0000) (0xffff_ffff) * +--------------------------------+----------------+----------------+ * <---------- bad value! ----------> * * (in a signed view of the world, the "bad value" range corresponds to * a negative counter value). * * As an example, consider a refcount_inc() operation that causes the counter * to overflow: * * int old = atomic_fetch_add_relaxed(r); * // old is INT_MAX, refcount now INT_MIN (0x8000_0000) * if (old < 0) * atomic_set(r, REFCOUNT_SATURATED); * * If another thread also performs a refcount_inc() operation between the two * atomic operations, then the count will continue to edge closer to 0. If it * reaches a value of 1 before /any/ of the threads reset it to the saturated * value, then a concurrent refcount_dec_and_test() may erroneously free the * underlying object. * Linux limits the maximum number of tasks to PID_MAX_LIMIT, which is currently * 0x400000 (and can't easily be raised in the future beyond FUTEX_TID_MASK). * With the current PID limit, if no batched refcounting operations are used and * the attacker can't repeatedly trigger kernel oopses in the middle of refcount * operations, this makes it impossible for a saturated refcount to leave the * saturation range, even if it is possible for multiple uses of the same * refcount to nest in the context of a single task: * * (UINT_MAX+1-REFCOUNT_SATURATED) / PID_MAX_LIMIT = * 0x40000000 / 0x400000 = 0x100 = 256 * * If hundreds of references are added/removed with a single refcounting * operation, it may potentially be possible to leave the saturation range; but * given the precise timing details involved with the round-robin scheduling of * each thread manipulating the refcount and the need to hit the race multiple * times in succession, there doesn't appear to be a practical avenue of attack * even if using refcount_add() operations with larger increments. * * Memory ordering * =============== * * Memory ordering rules are slightly relaxed wrt regular atomic_t functions * and provide only what is strictly required for refcounts. * * The increments are fully relaxed; these will not provide ordering. The * rationale is that whatever is used to obtain the object we're increasing the * reference count on will provide the ordering. For locked data structures, * its the lock acquire, for RCU/lockless data structures its the dependent * load. * * Do note that inc_not_zero() provides a control dependency which will order * future stores against the inc, this ensures we'll never modify the object * if we did not in fact acquire a reference. * * The decrements will provide release order, such that all the prior loads and * stores will be issued before, it also provides a control dependency, which * will order us against the subsequent free(). * * The control dependency is against the load of the cmpxchg (ll/sc) that * succeeded. This means the stores aren't fully ordered, but this is fine * because the 1->0 transition indicates no concurrency. * * Note that the allocator is responsible for ordering things between free() * and alloc(). * * The decrements dec_and_test() and sub_and_test() also provide acquire * ordering on success. * */ #ifndef _LINUX_REFCOUNT_H #define _LINUX_REFCOUNT_H #include <linux/atomic.h> #include <linux/bug.h> #include <linux/compiler.h> #include <linux/limits.h> #include <linux/spinlock_types.h> struct mutex; /** * struct refcount_t - variant of atomic_t specialized for reference counts * @refs: atomic_t counter field * * The counter saturates at REFCOUNT_SATURATED and will not move once * there. This avoids wrapping the counter and causing 'spurious' * use-after-free bugs. */ typedef struct refcount_struct { atomic_t refs; } refcount_t; #define REFCOUNT_INIT(n) { .refs = ATOMIC_INIT(n), } #define REFCOUNT_MAX INT_MAX #define REFCOUNT_SATURATED (INT_MIN / 2) enum refcount_saturation_type { REFCOUNT_ADD_NOT_ZERO_OVF, REFCOUNT_ADD_OVF, REFCOUNT_ADD_UAF, REFCOUNT_SUB_UAF, REFCOUNT_DEC_LEAK, }; void refcount_warn_saturate(refcount_t *r, enum refcount_saturation_type t); /** * refcount_set - set a refcount's value * @r: the refcount * @n: value to which the refcount will be set */ static inline void refcount_set(refcount_t *r, int n) { atomic_set(&r->refs, n); } /** * refcount_read - get a refcount's value * @r: the refcount * * Return: the refcount's value */ static inline unsigned int refcount_read(const refcount_t *r) { return atomic_read(&r->refs); } static inline __must_check bool __refcount_add_not_zero(int i, refcount_t *r, int *oldp) { int old = refcount_read(r); do { if (!old) break; } while (!atomic_try_cmpxchg_relaxed(&r->refs, &old, old + i)); if (oldp) *oldp = old; if (unlikely(old < 0 || old + i < 0)) refcount_warn_saturate(r, REFCOUNT_ADD_NOT_ZERO_OVF); return old; } /** * refcount_add_not_zero - add a value to a refcount unless it is 0 * @i: the value to add to the refcount * @r: the refcount * * Will saturate at REFCOUNT_SATURATED and WARN. * * Provides no memory ordering, it is assumed the caller has guaranteed the * object memory to be stable (RCU, etc.). It does provide a control dependency * and thereby orders future stores. See the comment on top. * * Use of this function is not recommended for the normal reference counting * use case in which references are taken and released one at a time. In these * cases, refcount_inc(), or one of its variants, should instead be used to * increment a reference count. * * Return: false if the passed refcount is 0, true otherwise */ static inline __must_check bool refcount_add_not_zero(int i, refcount_t *r) { return __refcount_add_not_zero(i, r, NULL); } static inline void __refcount_add(int i, refcount_t *r, int *oldp) { int old = atomic_fetch_add_relaxed(i, &r->refs); if (oldp) *oldp = old; if (unlikely(!old)) refcount_warn_saturate(r, REFCOUNT_ADD_UAF); else if (unlikely(old < 0 || old + i < 0)) refcount_warn_saturate(r, REFCOUNT_ADD_OVF); } /** * refcount_add - add a value to a refcount * @i: the value to add to the refcount * @r: the refcount * * Similar to atomic_add(), but will saturate at REFCOUNT_SATURATED and WARN. * * Provides no memory ordering, it is assumed the caller has guaranteed the * object memory to be stable (RCU, etc.). It does provide a control dependency * and thereby orders future stores. See the comment on top. * * Use of this function is not recommended for the normal reference counting * use case in which references are taken and released one at a time. In these * cases, refcount_inc(), or one of its variants, should instead be used to * increment a reference count. */ static inline void refcount_add(int i, refcount_t *r) { __refcount_add(i, r, NULL); } static inline __must_check bool __refcount_inc_not_zero(refcount_t *r, int *oldp) { return __refcount_add_not_zero(1, r, oldp); } /** * refcount_inc_not_zero - increment a refcount unless it is 0 * @r: the refcount to increment * * Similar to atomic_inc_not_zero(), but will saturate at REFCOUNT_SATURATED * and WARN. * * Provides no memory ordering, it is assumed the caller has guaranteed the * object memory to be stable (RCU, etc.). It does provide a control dependency * and thereby orders future stores. See the comment on top. * * Return: true if the increment was successful, false otherwise */ static inline __must_check bool refcount_inc_not_zero(refcount_t *r) { return __refcount_inc_not_zero(r, NULL); } static inline void __refcount_inc(refcount_t *r, int *oldp) { __refcount_add(1, r, oldp); } /** * refcount_inc - increment a refcount * @r: the refcount to increment * * Similar to atomic_inc(), but will saturate at REFCOUNT_SATURATED and WARN. * * Provides no memory ordering, it is assumed the caller already has a * reference on the object. * * Will WARN if the refcount is 0, as this represents a possible use-after-free * condition. */ static inline void refcount_inc(refcount_t *r) { __refcount_inc(r, NULL); } static inline __must_check bool __refcount_sub_and_test(int i, refcount_t *r, int *oldp) { int old = atomic_fetch_sub_release(i, &r->refs); if (oldp) *oldp = old; if (old == i) { smp_acquire__after_ctrl_dep(); return true; } if (unlikely(old < 0 || old - i < 0)) refcount_warn_saturate(r, REFCOUNT_SUB_UAF); return false; } /** * refcount_sub_and_test - subtract from a refcount and test if it is 0 * @i: amount to subtract from the refcount * @r: the refcount * * Similar to atomic_dec_and_test(), but it will WARN, return false and * ultimately leak on underflow and will fail to decrement when saturated * at REFCOUNT_SATURATED. * * Provides release memory ordering, such that prior loads and stores are done * before, and provides an acquire ordering on success such that free() * must come after. * * Use of this function is not recommended for the normal reference counting * use case in which references are taken and released one at a time. In these * cases, refcount_dec(), or one of its variants, should instead be used to * decrement a reference count. * * Return: true if the resulting refcount is 0, false otherwise */ static inline __must_check bool refcount_sub_and_test(int i, refcount_t *r) { return __refcount_sub_and_test(i, r, NULL); } static inline __must_check bool __refcount_dec_and_test(refcount_t *r, int *oldp) { return __refcount_sub_and_test(1, r, oldp); } /** * refcount_dec_and_test - decrement a refcount and test if it is 0 * @r: the refcount * * Similar to atomic_dec_and_test(), it will WARN on underflow and fail to * decrement when saturated at REFCOUNT_SATURATED. * * Provides release memory ordering, such that prior loads and stores are done * before, and provides an acquire ordering on success such that free() * must come after. * * Return: true if the resulting refcount is 0, false otherwise */ static inline __must_check bool refcount_dec_and_test(refcount_t *r) { return __refcount_dec_and_test(r, NULL); } static inline void __refcount_dec(refcount_t *r, int *oldp) { int old = atomic_fetch_sub_release(1, &r->refs); if (oldp) *oldp = old; if (unlikely(old <= 1)) refcount_warn_saturate(r, REFCOUNT_DEC_LEAK); } /** * refcount_dec - decrement a refcount * @r: the refcount * * Similar to atomic_dec(), it will WARN on underflow and fail to decrement * when saturated at REFCOUNT_SATURATED. * * Provides release memory ordering, such that prior loads and stores are done * before. */ static inline void refcount_dec(refcount_t *r) { __refcount_dec(r, NULL); } extern __must_check bool refcount_dec_if_one(refcount_t *r); extern __must_check bool refcount_dec_not_one(refcount_t *r); extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock); extern __must_check bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock); extern __must_check bool refcount_dec_and_lock_irqsave(refcount_t *r, spinlock_t *lock, unsigned long *flags); #endif /* _LINUX_REFCOUNT_H */
2 2 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 #ifdef CONFIG_PREEMPTIRQ_TRACEPOINTS #undef TRACE_SYSTEM #define TRACE_SYSTEM preemptirq #if !defined(_TRACE_PREEMPTIRQ_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_PREEMPTIRQ_H #include <linux/ktime.h> #include <linux/tracepoint.h> #include <linux/string.h> #include <asm/sections.h> DECLARE_EVENT_CLASS(preemptirq_template, TP_PROTO(unsigned long ip, unsigned long parent_ip), TP_ARGS(ip, parent_ip), TP_STRUCT__entry( __field(s32, caller_offs) __field(s32, parent_offs) ), TP_fast_assign( __entry->caller_offs = (s32)(ip - (unsigned long)_stext); __entry->parent_offs = (s32)(parent_ip - (unsigned long)_stext); ), TP_printk("caller=%pS parent=%pS", (void *)((unsigned long)(_stext) + __entry->caller_offs), (void *)((unsigned long)(_stext) + __entry->parent_offs)) ); #ifdef CONFIG_TRACE_IRQFLAGS DEFINE_EVENT(preemptirq_template, irq_disable, TP_PROTO(unsigned long ip, unsigned long parent_ip), TP_ARGS(ip, parent_ip)); DEFINE_EVENT(preemptirq_template, irq_enable, TP_PROTO(unsigned long ip, unsigned long parent_ip), TP_ARGS(ip, parent_ip)); #else #define trace_irq_enable(...) #define trace_irq_disable(...) #define trace_irq_enable_rcuidle(...) #define trace_irq_disable_rcuidle(...) #endif #ifdef CONFIG_TRACE_PREEMPT_TOGGLE DEFINE_EVENT(preemptirq_template, preempt_disable, TP_PROTO(unsigned long ip, unsigned long parent_ip), TP_ARGS(ip, parent_ip)); DEFINE_EVENT(preemptirq_template, preempt_enable, TP_PROTO(unsigned long ip, unsigned long parent_ip), TP_ARGS(ip, parent_ip)); #else #define trace_preempt_enable(...) #define trace_preempt_disable(...) #define trace_preempt_enable_rcuidle(...) #define trace_preempt_disable_rcuidle(...) #endif #endif /* _TRACE_PREEMPTIRQ_H */ #include <trace/define_trace.h> #else /* !CONFIG_PREEMPTIRQ_TRACEPOINTS */ #define trace_irq_enable(...) #define trace_irq_disable(...) #define trace_irq_enable_rcuidle(...) #define trace_irq_disable_rcuidle(...) #define trace_preempt_enable(...) #define trace_preempt_disable(...) #define trace_preempt_enable_rcuidle(...) #define trace_preempt_disable_rcuidle(...) #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 #ifndef _LINUX_SCHED_ISOLATION_H #define _LINUX_SCHED_ISOLATION_H #include <linux/cpumask.h> #include <linux/init.h> #include <linux/tick.h> enum hk_flags { HK_FLAG_TIMER = 1, HK_FLAG_RCU = (1 << 1), HK_FLAG_MISC = (1 << 2), HK_FLAG_SCHED = (1 << 3), HK_FLAG_TICK = (1 << 4), HK_FLAG_DOMAIN = (1 << 5), HK_FLAG_WQ = (1 << 6), HK_FLAG_MANAGED_IRQ = (1 << 7), HK_FLAG_KTHREAD = (1 << 8), }; #ifdef CONFIG_CPU_ISOLATION DECLARE_STATIC_KEY_FALSE(housekeeping_overridden); extern int housekeeping_any_cpu(enum hk_flags flags); extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags); extern bool housekeeping_enabled(enum hk_flags flags); extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags); extern bool housekeeping_test_cpu(int cpu, enum hk_flags flags); extern void __init housekeeping_init(void); #else static inline int housekeeping_any_cpu(enum hk_flags flags) { return smp_processor_id(); } static inline const struct cpumask *housekeeping_cpumask(enum hk_flags flags) { return cpu_possible_mask; } static inline bool housekeeping_enabled(enum hk_flags flags) { return false; } static inline void housekeeping_affine(struct task_struct *t, enum hk_flags flags) { } static inline void housekeeping_init(void) { } #endif /* CONFIG_CPU_ISOLATION */ static inline bool housekeeping_cpu(int cpu, enum hk_flags flags) { #ifdef CONFIG_CPU_ISOLATION if (static_branch_unlikely(&housekeeping_overridden)) return housekeeping_test_cpu(cpu, flags); #endif return true; } #endif /* _LINUX_SCHED_ISOLATION_H */
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 /* SPDX-License-Identifier: GPL-2.0 */ #undef TRACE_SYSTEM #define TRACE_SYSTEM pagemap #if !defined(_TRACE_PAGEMAP_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_PAGEMAP_H #include <linux/tracepoint.h> #include <linux/mm.h> #define PAGEMAP_MAPPED 0x0001u #define PAGEMAP_ANONYMOUS 0x0002u #define PAGEMAP_FILE 0x0004u #define PAGEMAP_SWAPCACHE 0x0008u #define PAGEMAP_SWAPBACKED 0x0010u #define PAGEMAP_MAPPEDDISK 0x0020u #define PAGEMAP_BUFFERS 0x0040u #define trace_pagemap_flags(page) ( \ (PageAnon(page) ? PAGEMAP_ANONYMOUS : PAGEMAP_FILE) | \ (page_mapped(page) ? PAGEMAP_MAPPED : 0) | \ (PageSwapCache(page) ? PAGEMAP_SWAPCACHE : 0) | \ (PageSwapBacked(page) ? PAGEMAP_SWAPBACKED : 0) | \ (PageMappedToDisk(page) ? PAGEMAP_MAPPEDDISK : 0) | \ (page_has_private(page) ? PAGEMAP_BUFFERS : 0) \ ) TRACE_EVENT(mm_lru_insertion, TP_PROTO( struct page *page, int lru ), TP_ARGS(page, lru), TP_STRUCT__entry( __field(struct page *, page ) __field(unsigned long, pfn ) __field(int, lru ) __field(unsigned long, flags ) ), TP_fast_assign( __entry->page = page; __entry->pfn = page_to_pfn(page); __entry->lru = lru; __entry->flags = trace_pagemap_flags(page); ), /* Flag format is based on page-types.c formatting for pagemap */ TP_printk("page=%p pfn=%lu lru=%d flags=%s%s%s%s%s%s", __entry->page, __entry->pfn, __entry->lru, __entry->flags & PAGEMAP_MAPPED ? "M" : " ", __entry->flags & PAGEMAP_ANONYMOUS ? "a" : "f", __entry->flags & PAGEMAP_SWAPCACHE ? "s" : " ", __entry->flags & PAGEMAP_SWAPBACKED ? "b" : " ", __entry->flags & PAGEMAP_MAPPEDDISK ? "d" : " ", __entry->flags & PAGEMAP_BUFFERS ? "B" : " ") ); TRACE_EVENT(mm_lru_activate, TP_PROTO(struct page *page), TP_ARGS(page), TP_STRUCT__entry( __field(struct page *, page ) __field(unsigned long, pfn ) ), TP_fast_assign( __entry->page = page; __entry->pfn = page_to_pfn(page); ), /* Flag format is based on page-types.c formatting for pagemap */ TP_printk("page=%p pfn=%lu", __entry->page, __entry->pfn) ); #endif /* _TRACE_PAGEMAP_H */ /* This part must be outside protection */ #include <trace/define_trace.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_