loop5: detected capacity change from 0 to 31
Call Trace:
======================================================
WARNING: possible circular locking dependency detected
5.17.0-rc8-next-20220318 #1 Not tainted
------------------------------------------------------
syz-executor.3/22581 is trying to acquire lock:
ffffffff851f5518 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0xe/0x60
but task is already holding lock:
ffff88800d9d8820 (&ctx->lock){-.-.}-{2:2}, at: __perf_install_in_context+0x12d/0x310
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ctx->lock){-.-.}-{2:2}:
_raw_spin_lock+0x2a/0x40
__perf_event_task_sched_out+0x519/0x1950
__schedule+0xebf/0x21a0
schedule+0xd2/0x1f0
exit_to_user_mode_prepare+0x114/0x1a0
syscall_exit_to_user_mode+0x19/0x50
do_syscall_64+0x48/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (&rq->__lock){-.-.}-{2:2}:
_raw_spin_lock_nested+0x30/0x40
raw_spin_rq_lock_nested+0x1e/0x30
task_fork_fair+0x63/0x4d0
sched_cgroup_fork+0x343/0x490
copy_process+0x4272/0x6d10
kernel_clone+0xe7/0xa60
kernel_thread+0xb5/0xf0
rest_init+0x24/0x3d0
start_kernel+0x489/0x4aa
secondary_startup_64_no_verify+0xd5/0xdb
-> #1 (&p->pi_lock){-.-.}-{2:2}:
_raw_spin_lock_irqsave+0x39/0x50
try_to_wake_up+0xa5/0x1060
up+0x75/0xb0
__up_console_sem+0x6e/0x80
console_unlock+0x603/0xd40
vprintk_emit+0x1b4/0x550
vprintk+0x80/0x90
_printk+0xba/0xed
kauditd_hold_skb.cold+0x3f/0x4e
kauditd_send_queue+0x22b/0x290
kauditd_thread+0x762/0xba0
kthread+0x2f0/0x3a0
ret_from_fork+0x22/0x30
-> #0 ((console_sem).lock){-.-.}-{2:2}:
__lock_acquire+0x2c2f/0x6120
lock_acquire+0x1a2/0x4d0
_raw_spin_lock_irqsave+0x39/0x50
down_trylock+0xe/0x60
__down_trylock_console_sem+0x3b/0xd0
vprintk_emit+0x162/0x550
vprintk+0x80/0x90
_printk+0xba/0xed
show_trace_log_lvl+0x57/0x2bb
ex_handler_msr+0x311/0x3a0
fixup_exception+0x307/0xff0
exc_general_protection+0xf6/0x2d0
asm_exc_general_protection+0x1e/0x30
x86_pmu_enable_all+0x132/0x3c0
x86_pmu_enable+0x580/0xd90
ctx_resched+0x2b0/0x390
__perf_install_in_context+0x285/0x310
remote_function+0x125/0x1b0
generic_exec_single+0x203/0x300
smp_call_function_single+0x189/0x460
task_function_call+0xe5/0x170
perf_install_in_context+0x2cb/0x550
__do_sys_perf_event_open+0x1bf0/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(console_sem).lock --> &rq->__lock --> &ctx->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ctx->lock);
lock(&rq->__lock);
lock(&ctx->lock);
lock((console_sem).lock);
*** DEADLOCK ***
4 locks held by syz-executor.3/22581:
#0: ffff88803f1f78a0 (&sig->exec_update_lock){++++}-{3:3}, at: __do_sys_perf_event_open+0x1023/0x3040
#1: ffff88800d9d88b0 (&ctx->mutex){+.+.}-{3:3}, at: __do_sys_perf_event_open+0x17cd/0x3040
#2: ffff88806ce3f220 (&cpuctx_lock){-.-.}-{2:2}, at: __perf_install_in_context+0xf4/0x310
#3: ffff88800d9d8820 (&ctx->lock){-.-.}-{2:2}, at: __perf_install_in_context+0x12d/0x310
stack backtrace:
CPU: 0 PID: 22581 Comm: syz-executor.3 Not tainted 5.17.0-rc8-next-20220318 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x8b/0xb3
check_noncircular+0x25f/0x2e0
__lock_acquire+0x2c2f/0x6120
lock_acquire+0x1a2/0x4d0
_raw_spin_lock_irqsave+0x39/0x50
down_trylock+0xe/0x60
__down_trylock_console_sem+0x3b/0xd0
vprintk_emit+0x162/0x550
vprintk+0x80/0x90
_printk+0xba/0xed
show_trace_log_lvl+0x57/0x2bb
ex_handler_msr+0x311/0x3a0
fixup_exception+0x307/0xff0
exc_general_protection+0xf6/0x2d0
asm_exc_general_protection+0x1e/0x30
RIP: 0010:x86_pmu_enable_all+0x132/0x3c0
Code: f7 d7 49 21 c7 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 64 02 00 00 48 8b 9b 70 01 00 00 4c 89 fa 44 89 f8 48 c1 ea 20 89 d9 <0f> 30 0f 1f 44 00 00 e8 a2 73 42 00 e8 9d 73 42 00 8b 1d 83 c1 8b
RSP: 0018:ffff888041707968 EFLAGS: 00010012
RAX: 0000000000530000 RBX: 00000000c0010200 RCX: 00000000c0010200
RDX: 0000000000000004 RSI: ffffffff8100dd36 RDI: ffff88804167d738
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff8100dd25 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88806ce21c20 R14: ffff88806ce21e20 R15: 0000000400530000
x86_pmu_enable+0x580/0xd90
ctx_resched+0x2b0/0x390
__perf_install_in_context+0x285/0x310
remote_function+0x125/0x1b0
generic_exec_single+0x203/0x300
smp_call_function_single+0x189/0x460
task_function_call+0xe5/0x170
perf_install_in_context+0x2cb/0x550
__do_sys_perf_event_open+0x1bf0/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd978370b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
loop6: detected capacity change from 0 to 512
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
x86_pmu_enable+0x580/0xd90
CPU: 1 PID: 22600 Comm: syz-executor.4 Not tainted 5.17.0-rc8-next-20220318 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
ctx_resched+0x2b0/0x390
Call Trace:
__perf_install_in_context+0x285/0x310
dump_stack_lvl+0x8b/0xb3
should_fail.cold+0x5/0xa
remote_function+0x125/0x1b0
should_failslab+0x5/0x10
kmem_cache_alloc+0x5b/0x480
generic_exec_single+0x203/0x300
security_file_alloc+0x34/0x170
smp_call_function_single+0x189/0x460
__alloc_file+0xb6/0x240
alloc_empty_file+0x6d/0x170
alloc_file+0x59/0x590
alloc_file_pseudo+0x16a/0x250
task_function_call+0xe5/0x170
anon_inode_getfile+0xb0/0x1e0
__do_sys_perf_event_open+0xfb7/0x3040
perf_install_in_context+0x2cb/0x550
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3f34685b19
__do_sys_perf_event_open+0x1bf0/0x3040
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3f31bfb188 EFLAGS: 00000246
ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f3f34798f60 RCX: 00007f3f34685b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
do_syscall_64+0x3b/0x90
RBP: 00007f3f31bfb1d0 R08: 0000000000000000 R09: 0000000000000000
entry_SYSCALL_64_after_hwframe+0x44/0xae
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000002
RIP: 0033:0x7fd978370b19
R13: 00007ffdedca87df R14: 00007f3f31bfb300 R15: 0000000000022000
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
CPU: 1 PID: 22704 Comm: syz-executor.4 Not tainted 5.17.0-rc8-next-20220318 #1
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
Call Trace:
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
dump_stack_lvl+0x8b/0xb3
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
should_fail.cold+0x5/0xa
Call Trace:
should_failslab+0x5/0x10
kmem_cache_alloc+0x5b/0x480
x86_pmu_stop+0x149/0x330
security_file_alloc+0x34/0x170
x86_pmu_del+0x1be/0x610
__alloc_file+0xb6/0x240
event_sched_out+0x2ed/0xaf0
alloc_empty_file+0x6d/0x170
group_sched_out.part.0+0x115/0x360
alloc_file+0x59/0x590
ctx_sched_out+0x7db/0xa90
alloc_file_pseudo+0x16a/0x250
__perf_event_task_sched_out+0x6ae/0x1950
anon_inode_getfile+0xb0/0x1e0
__do_sys_perf_event_open+0xfb7/0x3040
__schedule+0xebf/0x21a0
do_syscall_64+0x3b/0x90
preempt_schedule_common+0x45/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
__cond_resched+0x13/0x20
RIP: 0033:0x7f3f34685b19
__mutex_lock+0xa3/0x1480
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3f31bfb188 EFLAGS: 00000246
ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f3f34798f60 RCX: 00007f3f34685b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007f3f31bfb1d0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffdedca87df R14: 00007f3f31bfb300 R15: 0000000000022000
__do_sys_perf_event_open+0x1d13/0x3040
loop1: detected capacity change from 0 to 512
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd978370b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
EXT4-fs warning (device loop5): __ext4_fill_super:4450: metadata_csum and uninit_bg are redundant flags; please run fsck.
EXT4-fs (loop5): VFS: Found ext4 filesystem with unknown checksum algorithm.
EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
EXT4-fs (loop1): ext4_check_descriptors: Block bitmap for group 0 not in group (block 0)!
EXT4-fs (loop1): group descriptors corrupted!
Call Trace:
x86_pmu_enable+0x580/0xd90
__perf_event_task_sched_in+0x5e4/0x770
finish_task_switch.isra.0+0x45c/0x870
__schedule+0x890/0x21a0
preempt_schedule_common+0x45/0xc0
__cond_resched+0x13/0x20
__mutex_lock+0xa3/0x1480
__do_sys_perf_event_open+0x1d13/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd978370b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
Call Trace:
x86_pmu_stop+0x149/0x330
x86_pmu_del+0x1be/0x610
event_sched_out+0x2ed/0xaf0
group_sched_out.part.0+0x115/0x360
ctx_sched_out+0x7db/0xa90
__perf_event_task_sched_out+0x6ae/0x1950
__schedule+0xebf/0x21a0
preempt_schedule_common+0x45/0xc0
__cond_resched+0x13/0x20
__mutex_lock+0xa3/0x1480
__do_sys_perf_event_open+0x1d13/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd978370b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
Call Trace:
x86_pmu_enable+0x580/0xd90
__perf_event_task_sched_in+0x5e4/0x770
finish_task_switch.isra.0+0x45c/0x870
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
__schedule+0x890/0x21a0
CPU: 1 PID: 22723 Comm: syz-executor.4 Not tainted 5.17.0-rc8-next-20220318 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x8b/0xb3
should_fail.cold+0x5/0xa
preempt_schedule_common+0x45/0xc0
_copy_to_user+0x2a/0x140
__cond_resched+0x13/0x20
simple_read_from_buffer+0xcc/0x160
__mutex_lock+0xa3/0x1480
proc_fail_nth_read+0x194/0x220
vfs_read+0x1f0/0x5e0
ksys_read+0x12d/0x250
__do_sys_perf_event_open+0x1d13/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3f3463869c
Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48
do_syscall_64+0x3b/0x90
RSP: 002b:00007f3f31bfb170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
entry_SYSCALL_64_after_hwframe+0x44/0xae
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f3f3463869c
RIP: 0033:0x7fd978370b19
RDX: 000000000000000f RSI: 00007f3f31bfb1e0 RDI: 0000000000000003
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RBP: 00007f3f31bfb1d0 R08: 0000000000000000 R09: 0000000000000000
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000002
ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
R13: 00007ffdedca87df R14: 00007f3f31bfb300 R15: 0000000000022000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
Call Trace:
x86_pmu_stop+0x149/0x330
x86_pmu_del+0x1be/0x610
event_sched_out+0x2ed/0xaf0
group_sched_out.part.0+0x115/0x360
ctx_sched_out+0x7db/0xa90
__perf_event_task_sched_out+0x6ae/0x1950
__schedule+0xebf/0x21a0
preempt_schedule_common+0x45/0xc0
__cond_resched+0x13/0x20
__mutex_lock+0xa3/0x1480
__do_sys_perf_event_open+0x1d13/0x3040
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd978370b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9758e6188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd978483f60 RCX: 00007fd978370b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100
RBP: 00007fd9783caf6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8bd67b0f R14: 00007fd9758e6300 R15: 0000000000022000
EXT4-fs (loop6): mounted filesystem without journal. Quota mode: none.
----------------
Code disassembly (best guess):
0: f7 d7 not %edi
2: 49 21 c7 and %rax,%r15
5: 48 89 f8 mov %rdi,%rax
8: 48 c1 e8 03 shr $0x3,%rax
c: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
11: 0f 85 64 02 00 00 jne 0x27b
17: 48 8b 9b 70 01 00 00 mov 0x170(%rbx),%rbx
1e: 4c 89 fa mov %r15,%rdx
21: 44 89 f8 mov %r15d,%eax
24: 48 c1 ea 20 shr $0x20,%rdx
28: 89 d9 mov %ebx,%ecx
* 2a: 0f 30 wrmsr <-- trapping instruction
2c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
31: e8 a2 73 42 00 callq 0x4273d8
36: e8 9d 73 42 00 callq 0x4273d8
3b: 8b .byte 0x8b
3c: 1d .byte 0x1d
3d: 83 c1 8b add $0xffffff8b,%ecx