======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------------------- syz-executor.1/6388 just changed the state of lock: ffff88802a041910 (&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 *** 4 locks held by syz-executor.1/6388: #0: ffff888015ee2420 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0x12f/0x260 fs/read_write.c:643 #1: ffff8880607cf260 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] #1: ffff8880607cf260 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: shmem_file_write_iter+0x8c/0x140 mm/shmem.c:2916 #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: filemap_get_entry+0xd5/0x470 mm/filemap.c:1813 #3: ffffc90000a08cb0 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x5b0 kernel/time/timer.c:1789 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_delete+0x45/0x60 sound/core/seq/seq_queue.c:188 snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526 delete_seq_queue.isra.0+0xc8/0x150 sound/core/seq/oss/seq_oss_init.c:371 odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144 __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_delete+0x45/0x60 sound/core/seq/seq_queue.c:188 snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526 delete_seq_queue.isra.0+0xc8/0x150 sound/core/seq/oss/seq_oss_init.c:371 odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144 __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_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_stop+0x197/0x1f0 sound/core/pcm_native.c:1520 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_stop sound/core/pcm_native.c:1543 [inline] snd_pcm_drop+0x165/0x2b0 sound/core/pcm_native.c:2208 snd_pcm_kernel_ioctl+0x22d/0x2d0 sound/core/pcm_native.c:3444 snd_pcm_oss_sync+0x227/0x7f0 sound/core/oss/pcm_oss.c:1734 snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575 __fput+0x270/0xb80 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa7d/0x2be0 kernel/exit.c:878 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027 get_signal+0x2390/0x2760 kernel/signal.c:2907 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:212 do_syscall_64+0xe2/0x260 arch/x86/entry/common.c:89 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_stop+0x197/0x1f0 sound/core/pcm_native.c:1520 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_stop sound/core/pcm_native.c:1543 [inline] snd_pcm_drop+0x165/0x2b0 sound/core/pcm_native.c:2208 snd_pcm_kernel_ioctl+0x22d/0x2d0 sound/core/pcm_native.c:3444 snd_pcm_oss_sync+0x227/0x7f0 sound/core/oss/pcm_oss.c:1734 snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575 __fput+0x270/0xb80 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa7d/0x2be0 kernel/exit.c:878 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027 get_signal+0x2390/0x2760 kernel/signal.c:2907 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:212 do_syscall_64+0xe2/0x260 arch/x86/entry/common.c:89 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 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __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 lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] filemap_get_entry+0xdb/0x470 mm/filemap.c:1813 shmem_get_folio_gfp+0x369/0x13e0 mm/shmem.c:1988 shmem_get_folio mm/shmem.c:2166 [inline] shmem_write_begin+0x15a/0x370 mm/shmem.c:2750 generic_perform_write+0x272/0x620 mm/filemap.c:3930 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2926 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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_make_ready+0xe6/0x1b0 sound/core/oss/pcm_oss.c:1164 snd_pcm_oss_sync+0x1d7/0x7f0 sound/core/oss/pcm_oss.c:1730 snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575 __fput+0x270/0xb80 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa7d/0x2be0 kernel/exit.c:878 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027 get_signal+0x2390/0x2760 kernel/signal.c:2907 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:212 do_syscall_64+0xe2/0x260 arch/x86/entry/common.c:89 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 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __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 lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] filemap_get_entry+0xdb/0x470 mm/filemap.c:1813 shmem_get_folio_gfp+0x369/0x13e0 mm/shmem.c:1988 shmem_get_folio mm/shmem.c:2166 [inline] shmem_write_begin+0x15a/0x370 mm/shmem.c:2750 generic_perform_write+0x272/0x620 mm/filemap.c:3930 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2926 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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: 1 PID: 6388 Comm: syz-executor.1 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 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __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:lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 Code: c1 05 ea 37 97 7e 83 f8 01 0f 85 c8 02 00 00 9c 58 f6 c4 02 0f 85 b3 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000426f868 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200084df0f RCX: 0000000041e6004b RDX: 0000000000000001 RSI: ffffffff8b0cba40 RDI: ffffffff8b6e88a0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff27b4e30 R10: ffffffff93da7187 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d7b08e0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] filemap_get_entry+0xdb/0x470 mm/filemap.c:1813 shmem_get_folio_gfp+0x369/0x13e0 mm/shmem.c:1988 shmem_get_folio mm/shmem.c:2166 [inline] shmem_write_begin+0x15a/0x370 mm/shmem.c:2750 generic_perform_write+0x272/0x620 mm/filemap.c:3930 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2926 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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: 0033:0x7f136ac7cbaf Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48 RSP: 002b:00007f136ba67e80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007f136ac7cbaf RDX: 00000000013bd7ef RSI: 00007f1360a00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000550e R10: 0000000020000302 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f136ba67f80 R14: 00007f136ba67f40 R15: 00007f1360a00000 ---------------- Code disassembly (best guess): 0: c1 05 ea 37 97 7e 83 roll $0x83,0x7e9737ea(%rip) # 0x7e9737f1 7: f8 clc 8: 01 0f add %ecx,(%rdi) a: 85 c8 test %ecx,%eax c: 02 00 add (%rax),%al e: 00 9c 58 f6 c4 02 0f add %bl,0xf02c4f6(%rax,%rbx,2) 15: 85 b3 02 00 00 48 test %esi,0x48000002(%rbx) 1b: 85 ed test %ebp,%ebp 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c3 add %rax,%rbx <-- trapping instruction 2d: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 34: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3b: 00 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24