======================================================== WARNING: possible irq lock inversion dependency detected 5.19.0-rc6-syzkaller-00026-g5a29232d870d #0 Not tainted -------------------------------------------------------- syz-executor376/3611 just changed the state of lock: ffff88814a1b3148 (&timer->lock){..-.}-{2:2}, at: snd_timer_interrupt+0x211/0x1400 sound/core/timer.c:856 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (tasklist_lock){.+.+}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &timer->lock --> &new->fa_lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&timer->lock); lock(&new->fa_lock); lock(&timer->lock); *** DEADLOCK *** 1 lock held by syz-executor376/3611: #0: ffffc900001e0be0 ((&priv->tlist)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] #0: ffffc900001e0be0 ((&priv->tlist)){+.-.}-{0:0}, at: call_timer_fn+0xbb/0x210 kernel/time/timer.c:1464 the shortest dependencies between 2nd lock and 1st lock: -> (tasklist_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x224/0x9d0 kernel/exit.c:1508 kernel_wait+0xe4/0x230 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb4/0x220 kernel/umh.c:166 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 SOFTIRQ-ON-R at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x224/0x9d0 kernel/exit.c:1508 kernel_wait+0xe4/0x230 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb4/0x220 kernel/umh.c:166 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 INITIAL USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:326 copy_process+0x2414/0x3fa0 kernel/fork.c:2374 kernel_clone+0x22f/0x7a0 kernel/fork.c:2655 user_mode_thread+0x12d/0x190 kernel/fork.c:2724 rest_init+0x21/0x270 init/main.c:691 start_kernel+0x0/0x55b init/main.c:882 start_kernel+0x4ac/0x55b init/main.c:1137 secondary_startup_64_no_verify+0xcf/0xdb INITIAL READ USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x224/0x9d0 kernel/exit.c:1508 kernel_wait+0xe4/0x230 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb4/0x220 kernel/umh.c:166 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 send_sigio+0xbe/0x300 fs/fcntl.c:791 kill_fasync_rcu fs/fcntl.c:1002 [inline] kill_fasync+0x1e4/0x430 fs/fcntl.c:1016 snd_timer_user_ccallback+0x370/0x540 sound/core/timer.c:1386 snd_timer_notify1+0x1ad/0x350 sound/core/timer.c:516 snd_timer_stop1+0x7eb/0x950 sound/core/timer.c:657 snd_timer_stop sound/core/timer.c:710 [inline] snd_timer_close_locked+0x213/0x8e0 sound/core/timer.c:408 snd_timer_close sound/core/timer.c:463 [inline] snd_timer_user_tselect sound/core/timer.c:1762 [inline] __snd_timer_user_ioctl+0x360/0x54c0 sound/core/timer.c:2096 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> (&f->f_owner.lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:326 f_modown+0x38/0x340 fs/fcntl.c:90 __f_setown fs/fcntl.c:109 [inline] f_setown+0x113/0x1a0 fs/fcntl.c:137 do_fcntl+0x128/0x1370 fs/fcntl.c:376 __do_sys_fcntl fs/fcntl.c:453 [inline] __se_sys_fcntl+0xd5/0x1b0 fs/fcntl.c:438 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 INITIAL READ USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xd9/0x120 kernel/locking/spinlock.c:236 send_sigio+0x2f/0x300 fs/fcntl.c:777 kill_fasync_rcu fs/fcntl.c:1002 [inline] kill_fasync+0x1e4/0x430 fs/fcntl.c:1016 snd_timer_user_ccallback+0x370/0x540 sound/core/timer.c:1386 snd_timer_notify1+0x1ad/0x350 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_user_start sound/core/timer.c:1984 [inline] __snd_timer_user_ioctl+0xae7/0x54c0 sound/core/timer.c:2107 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 } ... key at: [] __alloc_file.__key+0x0/0x10 ... acquired at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xd9/0x120 kernel/locking/spinlock.c:236 send_sigio+0x2f/0x300 fs/fcntl.c:777 kill_fasync_rcu fs/fcntl.c:1002 [inline] kill_fasync+0x1e4/0x430 fs/fcntl.c:1016 snd_timer_user_ccallback+0x370/0x540 sound/core/timer.c:1386 snd_timer_notify1+0x1ad/0x350 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_user_start sound/core/timer.c:1984 [inline] __snd_timer_user_ioctl+0xae7/0x54c0 sound/core/timer.c:2107 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> (&new->fa_lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:326 fasync_remove_entry+0xff/0x1d0 fs/fcntl.c:872 __fput+0x6cd/0x820 fs/file_table.c:314 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x52d/0x1eb0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 INITIAL READ USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xd9/0x120 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:995 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1016 snd_timer_user_ccallback+0x370/0x540 sound/core/timer.c:1386 snd_timer_notify1+0x1ad/0x350 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_user_start sound/core/timer.c:1984 [inline] __snd_timer_user_ioctl+0xae7/0x54c0 sound/core/timer.c:2107 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 } ... key at: [] fasync_insert_entry.__key+0x0/0x20 ... acquired at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xd9/0x120 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:995 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1016 snd_timer_user_ccallback+0x370/0x540 sound/core/timer.c:1386 snd_timer_notify1+0x1ad/0x350 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_user_start sound/core/timer.c:1984 [inline] __snd_timer_user_ioctl+0xae7/0x54c0 sound/core/timer.c:2107 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> (&timer->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 snd_timer_interrupt+0x211/0x1400 sound/core/timer.c:856 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x76a/0x980 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x382/0x793 kernel/softirq.c:571 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 rcu_lockdep_current_cpu_online+0xe4/0x120 kernel/rcu/tree.c:1193 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_sched_held+0x74/0x130 kernel/rcu/update.c:123 trace_kmem_cache_free+0x2d/0xd0 include/trace/events/kmem.h:138 kmem_cache_free+0x47/0x270 mm/slub.c:3552 file_free fs/file_table.c:56 [inline] __fput+0x5da/0x820 fs/file_table.c:335 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x52d/0x1eb0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 INITIAL USE at: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 snd_timer_stop1+0x5c/0x950 sound/core/timer.c:626 snd_timer_stop sound/core/timer.c:710 [inline] snd_timer_user_start sound/core/timer.c:1981 [inline] __snd_timer_user_ioctl+0x267/0x54c0 sound/core/timer.c:2107 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 } ... key at: [] snd_timer_new.__key+0x0/0x20 ... acquired at: mark_lock+0x21c/0x350 kernel/locking/lockdep.c:4632 __lock_acquire+0xb81/0x1f80 kernel/locking/lockdep.c:5007 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 snd_timer_interrupt+0x211/0x1400 sound/core/timer.c:856 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x76a/0x980 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x382/0x793 kernel/softirq.c:571 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 rcu_lockdep_current_cpu_online+0xe4/0x120 kernel/rcu/tree.c:1193 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_sched_held+0x74/0x130 kernel/rcu/update.c:123 trace_kmem_cache_free+0x2d/0xd0 include/trace/events/kmem.h:138 kmem_cache_free+0x47/0x270 mm/slub.c:3552 file_free fs/file_table.c:56 [inline] __fput+0x5da/0x820 fs/file_table.c:335 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x52d/0x1eb0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 stack backtrace: CPU: 1 PID: 3611 Comm: syz-executor376 Not tainted 5.19.0-rc6-syzkaller-00026-g5a29232d870d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_irq_inversion_bug+0x58c/0x6f0 kernel/locking/lockdep.c:4040 mark_lock_irq+0x9d2/0xf00 kernel/locking/lockdep.c:4203 mark_lock+0x21c/0x350 kernel/locking/lockdep.c:4632 __lock_acquire+0xb81/0x1f80 kernel/locking/lockdep.c:5007 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 snd_timer_interrupt+0x211/0x1400 sound/core/timer.c:856 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x76a/0x980 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x382/0x793 kernel/softirq.c:571 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:rcu_lockdep_current_cpu_online+0xe4/0x120 Code: 00 74 08 48 89 df e8 5b 72 69 00 4c 23 3b 75 1a 48 c7 c7 c0 3a b2 8c be 04 00 00 00 e8 e5 73 69 00 83 3d fe 6e 41 0b 00 74 11 01 65 ff 0d 3b a3 91 7e 74 0a 5b 41 5e 41 5f c3 31 c0 eb ed e8 RSP: 0018:ffffc90002fefbc0 EFLAGS: 00000202 RAX: 1ffffffff1964656 RBX: ffffffff8cb232b0 RCX: 0000000080000001 RDX: ffffffff8ae2d740 RSI: ffffffff8ae998a0 RDI: ffff8880b9b3aa20 RBP: ffffc90002fefc78 R08: dffffc0000000000 R09: fffffbfff1c073ee R10: fffffbfff1c073ee R11: 1ffffffff1c073ed R12: ffff888020f7c898 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000002 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_sched_held+0x74/0x130 kernel/rcu/update.c:123 trace_kmem_cache_free+0x2d/0xd0 include/trace/events/kmem.h:138 kmem_cache_free+0x47/0x270 mm/slub.c:3552 file_free fs/file_table.c:56 [inline] __fput+0x5da/0x820 fs/file_table.c:335 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x52d/0x1eb0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f6a2e531c89 Code: Unable to access opcode bytes at RIP 0x7f6a2e531c5f. RSP: 002b:00007ffddf5a4688 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6a2e5a6330 RCX: 00007f6a2e531c89 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000246 R12: 00007f6a2e5a6330 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 ---------------- Code disassembly (best guess): 0: 00 74 08 48 add %dh,0x48(%rax,%rcx,1) 4: 89 df mov %ebx,%edi 6: e8 5b 72 69 00 callq 0x697266 b: 4c 23 3b and (%rbx),%r15 e: 75 1a jne 0x2a 10: 48 c7 c7 c0 3a b2 8c mov $0xffffffff8cb23ac0,%rdi 17: be 04 00 00 00 mov $0x4,%esi 1c: e8 e5 73 69 00 callq 0x697406 21: 83 3d fe 6e 41 0b 00 cmpl $0x0,0xb416efe(%rip) # 0xb416f26 28: 74 11 je 0x3b * 2a: b0 01 mov $0x1,%al <-- trapping instruction 2c: 65 ff 0d 3b a3 91 7e decl %gs:0x7e91a33b(%rip) # 0x7e91a36e 33: 74 0a je 0x3f 35: 5b pop %rbx 36: 41 5e pop %r14 38: 41 5f pop %r15 3a: c3 retq 3b: 31 c0 xor %eax,%eax 3d: eb ed jmp 0x2c 3f: e8 .byte 0xe8