======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------------------- udevd/4513 just changed the state of lock: ffff888029af7910 (&group->lock #2){..-.}-{2:2} , at: _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 but this lock took another, SOFTIRQ-unsafe lock in the past: (&timer->lock ){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock( &timer->lock); local_irq_disable(); lock( &group->lock#2 ); lock( &timer->lock); lock( &group->lock#2 ); *** DEADLOCK *** 3 locks held by udevd/4513: #0: ffff88807d19a420 (sb_writers #6){.+.+}-{0:0} , at: do_unlinkat+0x1d3/0x750 fs/namei.c:4385 #1: ffff888023ccdeb0 (&type->i_mutex_dir_key #5/1 ){+.+.}-{3:3} , at: inode_lock_nested include/linux/fs.h:828 [inline] , at: do_unlinkat+0x288/0x750 fs/namei.c:4389 #2: ffffffff8e11e410 (tomoyo_ss ){.+.+}-{0:0} , at: srcu_lock_acquire include/linux/srcu.h:116 [inline] , at: srcu_read_lock include/linux/srcu.h:215 [inline] , at: tomoyo_read_lock security/tomoyo/common.h:1108 [inline] , at: tomoyo_path_perm+0x25f/0x450 security/tomoyo/file.c:821 the shortest dependencies between 2nd lock and 1st lock: -> (&timer->lock ){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:561 [inline] snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 snd_timer_close+0x8b/0xf0 sound/core/timer.c:464 snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302 queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126 snd_seq_queue_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:543 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:285 seq_free_client1 sound/core/seq/seq_clientmgr.c:278 [inline] seq_free_client+0x74/0x170 sound/core/seq/seq_clientmgr.c:306 snd_seq_release+0x50/0xe0 sound/core/seq/seq_clientmgr.c:387 __fput+0x270/0xb80 fs/file_table.c:422 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 SOFTIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:561 [inline] snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 snd_timer_close+0x8b/0xf0 sound/core/timer.c:464 snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302 queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126 snd_seq_queue_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:543 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:285 seq_free_client1 sound/core/seq/seq_clientmgr.c:278 [inline] seq_free_client+0x74/0x170 sound/core/seq/seq_clientmgr.c:306 snd_seq_release+0x50/0xe0 sound/core/seq/seq_clientmgr.c:387 __fput+0x270/0xb80 fs/file_table.c:422 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:561 [inline] snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 snd_timer_close+0x8b/0xf0 sound/core/timer.c:464 snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302 queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126 snd_seq_queue_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:543 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:285 seq_free_client1 sound/core/seq/seq_clientmgr.c:278 [inline] seq_free_client+0x74/0x170 sound/core/seq/seq_clientmgr.c:306 snd_seq_release+0x50/0xe0 sound/core/seq/seq_clientmgr.c:387 __fput+0x270/0xb80 fs/file_table.c:422 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 } ... key at: [] __key.6+0x0/0x40 ... acquired at: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline] snd_timer_notify+0x111/0x3e0 sound/core/timer.c:1040 snd_pcm_timer_notify sound/core/pcm_native.c:622 [inline] snd_pcm_post_start+0x272/0x350 sound/core/pcm_native.c:1459 snd_pcm_action_single+0x10a/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 __snd_pcm_lib_xfer+0x175b/0x1ea0 sound/core/pcm_lib.c:2301 snd_pcm_oss_read3+0x18e/0x2d0 sound/core/oss/pcm_oss.c:1281 snd_pcm_oss_read2+0x309/0x3d0 sound/core/oss/pcm_oss.c:1492 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1520 [inline] snd_pcm_oss_read+0x46e/0x760 sound/core/oss/pcm_oss.c:2773 do_loop_readv_writev fs/read_write.c:761 [inline] do_loop_readv_writev fs/read_write.c:749 [inline] vfs_readv+0x6a2/0x870 fs/read_write.c:934 do_readv+0x137/0x370 fs/read_write.c:994 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 -> (&group->lock#2){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 unwind_next_frame+0x168/0x23a0 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x1f9/0x440 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x19d/0x720 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x450 security/tomoyo/file.c:822 tomoyo_path_unlink+0x92/0xe0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x100/0x170 security/security.c:1851 do_unlinkat+0x55b/0x750 fs/namei.c:4399 __do_sys_unlink fs/namei.c:4450 [inline] __se_sys_unlink fs/namei.c:4448 [inline] __x64_sys_unlink+0xc7/0x110 fs/namei.c:4448 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] snd_pcm_group_lock_irq sound/core/pcm_native.c:97 [inline] snd_pcm_stream_lock_irq sound/core/pcm_native.c:136 [inline] class_pcm_stream_lock_irq_constructor include/sound/pcm.h:666 [inline] snd_pcm_hw_params+0x151/0x1a30 sound/core/pcm_native.c:740 snd_pcm_kernel_ioctl+0x147/0x2d0 sound/core/pcm_native.c:3434 snd_pcm_oss_change_params_locked+0x146c/0x3aa0 sound/core/oss/pcm_oss.c:965 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1105 [inline] snd_pcm_oss_get_active_substream+0x168/0x1d0 sound/core/oss/pcm_oss.c:1122 snd_pcm_oss_get_formats+0x7e/0x330 sound/core/oss/pcm_oss.c:1843 snd_pcm_oss_set_format sound/core/oss/pcm_oss.c:1883 [inline] snd_pcm_oss_ioctl+0x2ef7/0x37a0 sound/core/oss/pcm_oss.c:2648 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 } ... key at: [] __key.5+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4567 [inline] __lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 unwind_next_frame+0x168/0x23a0 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x1f9/0x440 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x19d/0x720 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x450 security/tomoyo/file.c:822 tomoyo_path_unlink+0x92/0xe0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x100/0x170 security/security.c:1851 do_unlinkat+0x55b/0x750 fs/namei.c:4399 __do_sys_unlink fs/namei.c:4450 [inline] __se_sys_unlink fs/namei.c:4448 [inline] __x64_sys_unlink+0xc7/0x110 fs/namei.c:4448 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 stack backtrace: CPU: 0 PID: 4513 Comm: udevd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_irq_inversion_bug.part.0+0x3e9/0x5a0 kernel/locking/lockdep.c:4080 print_irq_inversion_bug kernel/locking/lockdep.c:4033 [inline] check_usage_forwards kernel/locking/lockdep.c:4111 [inline] mark_lock_irq kernel/locking/lockdep.c:4243 [inline] mark_lock+0x574/0xc60 kernel/locking/lockdep.c:4678 mark_usage kernel/locking/lockdep.c:4567 [inline] __lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x168/0x23a0 arch/x86/kernel/unwind_orc.c:494 Code: 50 00 66 45 85 e4 0f 85 d9 02 00 00 e8 91 60 50 00 4c 8d 7b 35 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 dd 0b 00 00 48 b8 00 00 RSP: 0018:ffffc9000346f5d8 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffffc9000346f658 RCX: 1ffffffff28d0b54 RDX: 1ffff9200068ded1 RSI: ffffffff813c981f RDI: ffff88807b53b2c0 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000000 R13: ffffffff8178d3a0 R14: ffffc9000346f718 R15: ffffc9000346f68d arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x1f9/0x440 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x19d/0x720 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x450 security/tomoyo/file.c:822 tomoyo_path_unlink+0x92/0xe0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x100/0x170 security/security.c:1851 do_unlinkat+0x55b/0x750 fs/namei.c:4399 __do_sys_unlink fs/namei.c:4450 [inline] __se_sys_unlink fs/namei.c:4448 [inline] __x64_sys_unlink+0xc7/0x110 fs/namei.c:4448 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f87ff38dda7 Code: f0 ff ff 73 01 c3 48 8b 0d 7e 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe0bc8f3d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007ffe0bc8f9f8 RCX: 00007f87ff38dda7 RDX: 00007ffe0bc8f3fb RSI: 0000557d05b344cd RDI: 00007ffe0bc8f3e8 RBP: 0000557d2b811ee0 R08: 0000000000000000 R09: 00007ffe0bc8ed58 R10: 0000000000000010 R11: 0000000000000206 R12: 0000000000000119 R13: 00007ffe0bc8f3e8 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 50 push %rax 1: 00 66 45 add %ah,0x45(%rsi) 4: 85 e4 test %esp,%esp 6: 0f 85 d9 02 00 00 jne 0x2e5 c: e8 91 60 50 00 call 0x5060a2 11: 4c 8d 7b 35 lea 0x35(%rbx),%r15 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 4c 89 fa mov %r15,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax * 2a: 4c 89 fa mov %r15,%rdx <-- trapping instruction 2d: 83 e2 07 and $0x7,%edx 30: 38 d0 cmp %dl,%al 32: 7f 08 jg 0x3c 34: 84 c0 test %al,%al 36: 0f 85 dd 0b 00 00 jne 0xc19 3c: 48 rex.W 3d: b8 .byte 0xb8