FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-00239-gc6d64479d609 #0 Not tainted ------------------------------------------------------ syz.5.757/8774 is trying to acquire lock: ffffffff8e8154c0 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline] ffffffff8e8154c0 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline] ffffffff8e8154c0 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline] ffffffff8e8154c0 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3157 but task is already holding lock: ffff8880b873ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 raw_spin_rq_lock kernel/sched/sched.h:1506 [inline] task_rq_lock+0xc6/0x360 kernel/sched/core.c:700 cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161 css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x256/0x880 kernel/cgroup/cgroup.c:6688 copy_process+0x39e9/0x3d50 kernel/fork.c:2600 kernel_clone+0x223/0x880 kernel/fork.c:2786 user_mode_thread+0x132/0x1a0 kernel/fork.c:2864 rest_init+0x23/0x300 init/main.c:712 start_kernel+0x47f/0x500 init/main.c:1105 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #3 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xbe/0x14b0 kernel/sched/core.c:4165 __wake_up_common kernel/sched/wait.c:89 [inline] __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1821 serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1929 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1949 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:213 ma_pivots lib/maple_tree.c:655 [inline] mas_next_slot+0x104/0xea0 lib/maple_tree.c:4678 mas_find+0x950/0xbb0 lib/maple_tree.c:6059 vma_next include/linux/mm.h:1007 [inline] validate_mm+0x104/0x550 mm/vma.c:534 __split_vma+0xabd/0xc50 mm/vma.c:430 split_vma mm/vma.c:459 [inline] vma_modify+0x153a/0x1a80 mm/vma.c:1437 vma_modify_flags+0x3a5/0x430 mm/vma.c:1455 mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:664 do_mprotect_pkey+0x8d7/0xd70 mm/mprotect.c:838 __do_sys_mprotect mm/mprotect.c:859 [inline] __se_sys_mprotect mm/mprotect.c:856 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:856 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&tty->write_wait){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __wake_up_common_lock+0x25/0x1e0 kernel/sched/wait.c:105 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1821 serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1929 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1949 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:782 [inline] uart_write+0x3e4/0xa40 drivers/tty/serial/serial_core.c:636 process_output_block drivers/tty/n_tty.c:574 [inline] n_tty_write+0xd62/0x1230 drivers/tty/n_tty.c:2389 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write+0x546/0x9b0 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:711 [inline] serial8250_console_write+0x1a7/0x1ed0 drivers/tty/serial/8250/8250_port.c:3352 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x86b/0xeb0 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 register_console+0xbf5/0xfd0 kernel/printk/printk.c:4069 univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513 console_init+0x1b8/0x6f0 kernel/printk/printk.c:4262 start_kernel+0x2d8/0x500 init/main.c:1040 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 console_lock_spinning_enable kernel/printk/printk.c:1905 [inline] console_emit_next_record kernel/printk/printk.c:3086 [inline] console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 fail_dump lib/fault-inject.c:46 [inline] should_fail_ex+0x391/0x4e0 lib/fault-inject.c:154 strncpy_from_user+0x36/0x260 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306 bpf_prog_c1796171ffc7efef+0x3e/0x40 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2359 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2266/0x4bd0 kernel/sched/core.c:6690 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7015 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 lock_release+0x658/0xa30 kernel/locking/lockdep.c:5850 lock_vma_under_rcu+0x5fd/0x790 do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x17b/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 other info that might help us debug this: Chain exists of: console_owner --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(console_owner); *** DEADLOCK *** 5 locks held by syz.5.757/8774: #0: ffff88805fa2b148 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:704 [inline] #0: ffff88805fa2b148 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x34b/0x790 mm/memory.c:6243 #1: ffff8880b873ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #2: ffffffff8e939f20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8e939f20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e939f20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2315 [inline] #2: ffffffff8e939f20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2359 #3: ffffffff8e815520 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2432 #4: ffffffff8e815130 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline] #4: ffffffff8e815130 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline] #4: ffffffff8e815130 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline] #4: ffffffff8e815130 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3157 stack backtrace: CPU: 1 UID: 0 PID: 8774 Comm: syz.5.757 Not tainted 6.12.0-syzkaller-00239-gc6d64479d609 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 console_lock_spinning_enable kernel/printk/printk.c:1905 [inline] console_emit_next_record kernel/printk/printk.c:3086 [inline] console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 fail_dump lib/fault-inject.c:46 [inline] should_fail_ex+0x391/0x4e0 lib/fault-inject.c:154 strncpy_from_user+0x36/0x260 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306 bpf_prog_c1796171ffc7efef+0x3e/0x40 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2359 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2266/0x4bd0 kernel/sched/core.c:6690 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7015 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5850 Code: 3c 3b 00 74 08 4c 89 f7 e8 d5 2f 8b 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0000:ffffc90002e7fc80 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920005cffa2 RCX: ffffc90002e7fd03 RDX: 1ffff920005cffa0 RSI: ffffffff8c0add80 RDI: ffffffff8c604600 RBP: ffffc90002e7fdb0 R08: ffffffff942a28a7 R09: 1ffffffff2854514 R10: dffffc0000000000 R11: fffffbfff2854515 R12: 1ffff920005cff9c R13: 0000000000000246 R14: ffffc90002e7fd10 R15: dffffc0000000000 lock_vma_under_rcu+0x5fd/0x790 do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x17b/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f83aa5618e0 Code: Unable to access opcode bytes at 0x7f83aa5618b6. RSP: 002b:00007f83ab291be8 EFLAGS: 00010216 RAX: 0000000020000000 RBX: 6666666666666667 RCX: 0000000000000000 RDX: 00000000000003ff RSI: 0000000020000000 RDI: 00007f83ab291c10 RBP: 00007f83ab291c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000000 R11: 000000000004a000 R12: 0000000000000001 R13: 0000000000000001 R14: 00007f83aa735f80 R15: 00007fffba4fff28 CPU: 1 UID: 0 PID: 8774 Comm: syz.5.757 Not tainted 6.12.0-syzkaller-00239-gc6d64479d609 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:53 [inline] should_fail_ex+0x3b0/0x4e0 lib/fault-inject.c:154 strncpy_from_user+0x36/0x260 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306 bpf_prog_c1796171ffc7efef+0x3e/0x40 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2359 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2266/0x4bd0 kernel/sched/core.c:6690 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7015 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5850 Code: 3c 3b 00 74 08 4c 89 f7 e8 d5 2f 8b 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0000:ffffc90002e7fc80 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920005cffa2 RCX: ffffc90002e7fd03 RDX: 1ffff920005cffa0 RSI: ffffffff8c0add80 RDI: ffffffff8c604600 RBP: ffffc90002e7fdb0 R08: ffffffff942a28a7 R09: 1ffffffff2854514 R10: dffffc0000000000 R11: fffffbfff2854515 R12: 1ffff920005cff9c R13: 0000000000000246 R14: ffffc90002e7fd10 R15: dffffc0000000000 lock_vma_under_rcu+0x5fd/0x790 do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x17b/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f83aa5618e0 Code: Unable to access opcode bytes at 0x7f83aa5618b6. RSP: 002b:00007f83ab291be8 EFLAGS: 00010216 RAX: 0000000020000000 RBX: 6666666666666667 RCX: 0000000000000000 RDX: 00000000000003ff RSI: 0000000020000000 RDI: 00007f83ab291c10 RBP: 00007f83ab291c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000000 R11: 000000000004a000 R12: 0000000000000001 R13: 0000000000000001 R14: 00007f83aa735f80 R15: 00007fffba4fff28 ---------------- Code disassembly (best guess): 0: 3c 3b cmp $0x3b,%al 2: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1) 6: 89 f7 mov %esi,%edi 8: e8 d5 2f 8b 00 call 0x8b2fe2 d: f6 84 24 91 00 00 00 testb $0x2,0x91(%rsp) 14: 02 15: 75 77 jne 0x8e 17: 41 f7 c5 00 02 00 00 test $0x200,%r13d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 27 00 00 00 movq $0x0,(%r15,%r12,1) <-- trapping instruction 31: 00 32: 4b c7 44 27 08 00 00 movq $0x0,0x8(%r15,%r12,1) 39: 00 00 3b: 65 gs 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 04 25 add $0x25,%al