INFO: task syz-executor.4:25809 blocked for more than 143 seconds. Not tainted 5.19.0-rc4-syzkaller-00187-g089866061428 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28408 pid:25809 ppid: 3654 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5146 [inline] __schedule+0xa00/0x4b50 kernel/sched/core.c:6458 schedule+0xd2/0x1f0 kernel/sched/core.c:6530 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747 misc_open+0x5f/0x4a0 drivers/char/misc.c:107 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4a1/0x11f0 fs/open.c:848 do_open fs/namei.c:3520 [inline] path_openat+0x1c71/0x2910 fs/namei.c:3653 do_filp_open+0x1aa/0x400 fs/namei.c:3680 do_sys_openat2+0x16d/0x4c0 fs/open.c:1278 do_sys_open fs/open.c:1294 [inline] __do_sys_openat fs/open.c:1310 [inline] __se_sys_openat fs/open.c:1305 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1305 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f702e689109 RSP: 002b:00007f702f8b3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f702e79bf60 RCX: 00007f702e689109 RDX: 0000000000000042 RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 00007f702e6e305d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f702eccfb1f R14: 00007f702f8b3300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/u4:1/11: 6 locks held by kworker/1:0/22: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc900001c7da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888020d9d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888020d9d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff888041181190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff888041181190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff8880449c7118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff8880449c7118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 1 lock held by khungtaskd/28: #0: ffffffff8bd86660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491 2 locks held by acpid/2961: #0: ffff888016818158 (&joydev->mutex){+.+.}-{3:3}, at: joydev_close_device drivers/input/joydev.c:220 [inline] #0: ffff888016818158 (&joydev->mutex){+.+.}-{3:3}, at: joydev_release+0x187/0x290 drivers/input/joydev.c:252 #1: ffff8880449c52c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_close_device+0x42/0x1f0 drivers/input/input.c:726 2 locks held by getty/3287: #0: ffff88807faf0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d162e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xe50/0x13c0 drivers/tty/n_tty.c:2124 7 locks held by kworker/1:6/3684: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90003b3fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888147a95190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888147a95190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff888042672190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff888042672190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff8880449c0118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff8880449c0118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 #6: ffff8880449c52c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_register_handle+0x6d/0x510 drivers/input/input.c:2544 7 locks held by kworker/1:12/7023: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc9000444fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff8880209ed190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff8880209ed190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff8880771d5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff8880771d5190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff8880284a5118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff8880284a5118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffff88807c5f5a20 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #5: ffff88807c5f5a20 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #6: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 6 locks held by kworker/1:15/11164: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90009bdfda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888147b3d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888147b3d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff88807e253190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff88807e253190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff888079d0f118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff888079d0f118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 7 locks held by kworker/0:2/10300: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90009bafda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888147a55190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888147a55190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff88807818e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff88807818e190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff88807d4eb118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff88807d4eb118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffff88801c315a20 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #5: ffff88801c315a20 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #6: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 2 locks held by kworker/u4:7/16930: 7 locks held by kworker/1:20/21284: #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011a65d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc9000427fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888147b2d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888147b2d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4690 drivers/usb/core/hub.c:5691 #3: ffff888042997190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff888042997190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #4: ffff88807818c118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff88807818c118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #5: ffff888032d65a20 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #5: ffff888032d65a20 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x530 drivers/base/dd.c:964 #6: ffffffff8ceafca8 (input_mutex){+.+.}-{3:3}, at: input_register_device.cold+0x34/0x304 drivers/input/input.c:2378 2 locks held by syz-executor.3/25806: #0: ffffffff8c82f708 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x5f/0x4a0 drivers/char/misc.c:107 #1: ffffffff8bc536e8 (system_transition_mutex){+.+.}-{3:3}, at: snapshot_open+0x3b/0x2a0 kernel/power/user.c:54 1 lock held by syz-executor.4/25809: #0: ffffffff8c82f708 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x5f/0x4a0 drivers/char/misc.c:107 1 lock held by syz-executor.1/25818: #0: ffffffff8c82f708 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x5f/0x4a0 drivers/char/misc.c:107 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 5.19.0-rc4-syzkaller-00187-g089866061428 #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+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:369 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3600 Comm: syz-fuzzer Not tainted 5.19.0-rc4-syzkaller-00187-g089866061428 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3722 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3742 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3797 [inline] RIP: 0010:__lock_acquire+0x168a/0x5660 kernel/locking/lockdep.c:5053 Code: ed 60 78 56 90 48 89 5c 24 10 0f 84 a6 03 00 00 48 8d 14 ed 60 78 56 90 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 7e 2f 00 00 48 8b 1c ed 60 78 56 90 48 85 db 74 58 48 83 eb RSP: 0018:ffffc9000311fb00 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff90572680 RCX: ffffffff815e058e RDX: 1ffffffff20ae4d0 RSI: 0000000000000008 RDI: ffffffff9067f900 RBP: 00000000000015c4 R08: 0000000000000000 R09: ffffffff9067f907 R10: fffffbfff20cff20 R11: 0000000000000001 R12: ffff88802684c560 R13: ffff88802684bb00 R14: 0000000000000001 R15: 3df1592f76153240 FS: 000000c000030090(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555789a1680 CR3: 0000000072817000 CR4: 00000000003506e0 Call Trace: lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 debug_object_free lib/debugobjects.c:834 [inline] debug_object_free+0x56/0x350 lib/debugobjects.c:822 destroy_hrtimer_on_stack kernel/time/hrtimer.c:452 [inline] hrtimer_nanosleep+0x22b/0x4a0 kernel/time/hrtimer.c:2112 __do_sys_nanosleep kernel/time/hrtimer.c:2131 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:2118 [inline] __x64_sys_nanosleep+0x1dc/0x260 kernel/time/hrtimer.c:2118 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x46631d Code: 8b 44 24 20 b9 40 42 0f 00 f7 f1 48 89 04 24 b8 e8 03 00 00 f7 e2 48 89 44 24 08 48 89 e7 be 00 00 00 00 b8 23 00 00 00 0f 05 <48> 8b 6c 24 10 48 83 c4 18 c3 cc cc cc cc cc cc cc cc cc cc cc cc RSP: 002b:000000c00003ff10 EFLAGS: 00000202 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000002710 RCX: 000000000046631d RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000c00003ff10 RBP: 000000c00003ff20 R08: 0000000000000be1 R09: 00007ffec2175080 R10: 00007ffec2175090 R11: 0000000000000202 R12: 000000c00003ff10 R13: 000000c015029000 R14: 000000c0000004e0 R15: 00007fcfed7a6075 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 78 56 js 0x58 2: 90 nop 3: 48 89 5c 24 10 mov %rbx,0x10(%rsp) 8: 0f 84 a6 03 00 00 je 0x3b4 e: 48 8d 14 ed 60 78 56 lea -0x6fa987a0(,%rbp,8),%rdx 15: 90 16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1d: fc ff df 20: 48 c1 ea 03 shr $0x3,%rdx 24: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 28: 0f 85 7e 2f 00 00 jne 0x2fac <-- trapping instruction 2e: 48 8b 1c ed 60 78 56 mov -0x6fa987a0(,%rbp,8),%rbx 35: 90 36: 48 85 db test %rbx,%rbx 39: 74 58 je 0x93 3b: 48 rex.W 3c: 83 .byte 0x83 3d: eb .byte 0xeb