===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.14.0-rc6-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.4/25083 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff8880262906a8 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1012 [inline] ffff8880262906a8 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync+0x13b/0x430 fs/fcntl.c:1033 and this task is already holding: ffff8881477ad948 (&timer->lock){....}-{2:2}, at: snd_timer_start1+0x5b/0x640 sound/core/timer.c:541 which would create a new lock dependency: (&timer->lock){....}-{2:2} -> (&new->fa_lock){.+.+}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (&group->lock){..-.}-{2:2} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __do_softirq+0x372/0x783 kernel/softirq.c:558 do_softirq+0x14a/0x210 kernel/softirq.c:459 __local_bh_enable_ip+0x184/0x1c0 kernel/softirq.c:383 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x35f/0x3f0 net/batman-adv/network-coding.c:467 batadv_nc_worker+0x2da/0x5b0 net/batman-adv/network-coding.c:716 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 to a SOFTIRQ-irq-unsafe lock: (&new->fa_lock){.+.+}-{2:2} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 sock_wake_async+0x133/0x150 net/socket.c:1354 rcu_read_unlock include/linux/rcupdate.h:716 [inline] sk_wake_async+0x12e/0x200 include/net/sock.h:2328 tcp_rcv_state_process+0x1052/0x2410 net/ipv4/tcp_input.c:6437 tcp_v4_do_rcv+0x5b3/0x880 net/ipv4/tcp_ipv4.c:1716 sk_backlog_rcv include/net/sock.h:1023 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2655 release_sock+0x5d/0x1c0 net/core/sock.c:3179 inet_wait_for_connect net/ipv4/af_inet.c:597 [inline] __inet_stream_connect+0x5e2/0xe50 net/ipv4/af_inet.c:689 tcp_sendmsg_fastopen net/ipv4/tcp.c:1190 [inline] tcp_sendmsg_locked+0x3bb1/0x4230 net/ipv4/tcp.c:1232 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1461 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] __sys_sendto+0x541/0x720 net/socket.c:2019 __do_sys_sendto net/socket.c:2031 [inline] __se_sys_sendto net/socket.c:2027 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &group->lock --> &timer->lock --> &new->fa_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&new->fa_lock); local_irq_disable(); lock(&group->lock); lock(&timer->lock); lock(&group->lock); *** DEADLOCK *** 3 locks held by syz-executor.4/25083: #0: ffff88803297ad68 (&tu->ioctl_lock){+.+.}-{3:3}, at: snd_timer_user_ioctl+0x4d/0x80 sound/core/timer.c:2128 #1: ffff8881477ad948 (&timer->lock){....}-{2:2}, at: snd_timer_start1+0x5b/0x640 sound/core/timer.c:541 #2: ffffffff8c717ec0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&group->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __do_softirq+0x372/0x783 kernel/softirq.c:558 do_softirq+0x14a/0x210 kernel/softirq.c:459 __local_bh_enable_ip+0x184/0x1c0 kernel/softirq.c:383 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x35f/0x3f0 net/batman-adv/network-coding.c:467 batadv_nc_worker+0x2da/0x5b0 net/batman-adv/network-coding.c:716 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [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] snd_pcm_hw_params+0xca/0x1740 sound/core/pcm_native.c:681 snd_pcm_oss_change_params_locked+0x245a/0x4390 sound/core/oss/pcm_oss.c:947 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1091 [inline] snd_pcm_oss_make_ready sound/core/oss/pcm_oss.c:1150 [inline] snd_pcm_oss_sync+0x37c/0xee0 sound/core/oss/pcm_oss.c:1717 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] snd_pcm_group_init.__key+0x0/0x40 -> (&timer->lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_notify+0x105/0x3e0 sound/core/timer.c:1087 snd_pcm_timer_notify sound/core/pcm_native.c:590 [inline] snd_pcm_post_stop sound/core/pcm_native.c:1448 [inline] snd_pcm_action_single sound/core/pcm_native.c:1224 [inline] snd_pcm_action sound/core/pcm_native.c:1305 [inline] snd_pcm_stop+0x3b8/0x4c0 sound/core/pcm_native.c:1471 snd_pcm_drop+0x16d/0x290 sound/core/pcm_native.c:2150 snd_pcm_oss_sync+0x4f4/0xee0 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] snd_timer_new.__key+0x0/0x40 ... acquired at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_notify+0x105/0x3e0 sound/core/timer.c:1087 snd_pcm_timer_notify sound/core/pcm_native.c:590 [inline] snd_pcm_post_stop sound/core/pcm_native.c:1448 [inline] snd_pcm_action_single sound/core/pcm_native.c:1224 [inline] snd_pcm_action sound/core/pcm_native.c:1305 [inline] snd_pcm_stop+0x3b8/0x4c0 sound/core/pcm_native.c:1471 snd_pcm_drop+0x16d/0x290 sound/core/pcm_native.c:2150 snd_pcm_oss_sync+0x4f4/0xee0 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (&new->fa_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 sock_wake_async+0x133/0x150 net/socket.c:1354 rcu_read_unlock include/linux/rcupdate.h:716 [inline] sk_wake_async+0x12e/0x200 include/net/sock.h:2328 tcp_rcv_state_process+0x1052/0x2410 net/ipv4/tcp_input.c:6437 tcp_v4_do_rcv+0x5b3/0x880 net/ipv4/tcp_ipv4.c:1716 sk_backlog_rcv include/net/sock.h:1023 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2655 release_sock+0x5d/0x1c0 net/core/sock.c:3179 inet_wait_for_connect net/ipv4/af_inet.c:597 [inline] __inet_stream_connect+0x5e2/0xe50 net/ipv4/af_inet.c:689 tcp_sendmsg_fastopen net/ipv4/tcp.c:1190 [inline] tcp_sendmsg_locked+0x3bb1/0x4230 net/ipv4/tcp.c:1232 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1461 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] __sys_sendto+0x541/0x720 net/socket.c:2019 __do_sys_sendto net/socket.c:2031 [inline] __se_sys_sendto net/socket.c:2027 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae SOFTIRQ-ON-R at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 sock_wake_async+0x133/0x150 net/socket.c:1354 rcu_read_unlock include/linux/rcupdate.h:716 [inline] sk_wake_async+0x12e/0x200 include/net/sock.h:2328 tcp_rcv_state_process+0x1052/0x2410 net/ipv4/tcp_input.c:6437 tcp_v4_do_rcv+0x5b3/0x880 net/ipv4/tcp_ipv4.c:1716 sk_backlog_rcv include/net/sock.h:1023 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2655 release_sock+0x5d/0x1c0 net/core/sock.c:3179 inet_wait_for_connect net/ipv4/af_inet.c:597 [inline] __inet_stream_connect+0x5e2/0xe50 net/ipv4/af_inet.c:689 tcp_sendmsg_fastopen net/ipv4/tcp.c:1190 [inline] tcp_sendmsg_locked+0x3bb1/0x4230 net/ipv4/tcp.c:1232 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1461 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] __sys_sendto+0x541/0x720 net/socket.c:2019 __do_sys_sendto net/socket.c:2031 [inline] __se_sys_sendto net/socket.c:2027 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:311 fasync_remove_entry+0xff/0x1d0 fs/fcntl.c:890 __fput+0x65b/0x7b0 fs/file_table.c:277 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 sock_wake_async+0x133/0x150 net/socket.c:1354 rcu_read_unlock include/linux/rcupdate.h:716 [inline] sk_wake_async+0x12e/0x200 include/net/sock.h:2328 tcp_rcv_state_process+0x1052/0x2410 net/ipv4/tcp_input.c:6437 tcp_v4_do_rcv+0x5b3/0x880 net/ipv4/tcp_ipv4.c:1716 sk_backlog_rcv include/net/sock.h:1023 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2655 release_sock+0x5d/0x1c0 net/core/sock.c:3179 inet_wait_for_connect net/ipv4/af_inet.c:597 [inline] __inet_stream_connect+0x5e2/0xe50 net/ipv4/af_inet.c:689 tcp_sendmsg_fastopen net/ipv4/tcp.c:1190 [inline] tcp_sendmsg_locked+0x3bb1/0x4230 net/ipv4/tcp.c:1232 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1461 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] __sys_sendto+0x541/0x720 net/socket.c:2019 __do_sys_sendto net/socket.c:2031 [inline] __se_sys_sendto net/socket.c:2027 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] fasync_insert_entry.__key+0x0/0x40 ... acquired at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae stack backtrace: CPU: 0 PID: 25083 Comm: syz-executor.4 Not tainted 5.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 print_bad_irq_dependency kernel/locking/lockdep.c:2565 [inline] check_irq_usage kernel/locking/lockdep.c:2804 [inline] check_prev_add kernel/locking/lockdep.c:3055 [inline] check_prevs_add+0x4eaa/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 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:00007fc358c11188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 00000000000054a0 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffd61e40d7f R14: 00007fc358c11300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W