FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.9452/9872 is trying to acquire lock:
ffffffff8e0d15c0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x61/0x80 kernel/printk/printk.c:1897

but task is already holding lock:
ffff8880b863a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
ffff8880b863a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:638
       raw_spin_rq_lock kernel/sched/sched.h:1546 [inline]
       task_rq_lock+0xcf/0x490 kernel/sched/core.c:738
       cgroup_move_task+0x81/0x2a0 kernel/sched/psi.c:1170
       css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:951
       cgroup_post_fork+0x201/0x9d0 kernel/cgroup/cgroup.c:6913
       copy_process+0x602d/0x76a0 kernel/fork.c:2425
       kernel_clone+0xfc/0x930 kernel/fork.c:2609
       user_mode_thread+0xc8/0x110 kernel/fork.c:2685
       rest_init+0x23/0x2b0 init/main.c:722
       start_kernel+0x3f3/0x4e0 init/main.c:1111
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x148

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0xb7/0x1870 kernel/sched/core.c:4181
       __wake_up_common+0x132/0x1f0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:125 [inline]
       __wake_up+0x31/0x60 kernel/sched/wait.c:146
       tty_port_default_wakeup+0x47/0x60 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x761/0xcb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0x9e/0x270 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0xf5/0x1d0 drivers/tty/serial/8250/8250_core.c:82
       __handle_irq_event_percpu+0x233/0x920 kernel/irq/handle.c:203
       handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
       handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
       handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:310 [inline]
       __common_interrupt+0xcd/0x2f0 arch/x86/kernel/irq.c:325
       common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       is_anon_ns fs/mount.h:178 [inline]
       __prepend_path fs/d_path.c:122 [inline]
       prepend_path+0xaea/0xfb0 fs/d_path.c:172
       d_absolute_path+0xfe/0x1a0 fs/d_path.c:234
       tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
       tomoyo_realpath_from_path+0x355/0x6e0 security/tomoyo/realpath.c:271
       tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
       tomoyo_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771
       tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
       security_file_open+0x84/0x1e0 security/security.c:3183
       do_dentry_open+0x596/0x1530 fs/open.c:942
       vfs_open+0x82/0x3f0 fs/open.c:1097
       do_open fs/namei.c:3975 [inline]
       path_openat+0x1de4/0x2cb0 fs/namei.c:4134
       do_filp_open+0x20b/0x470 fs/namei.c:4161
       do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
       do_sys_open fs/open.c:1452 [inline]
       __do_sys_openat fs/open.c:1468 [inline]
       __se_sys_openat fs/open.c:1463 [inline]
       __x64_sys_openat+0x174/0x210 fs/open.c:1463
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:124 [inline]
       __wake_up+0x1c/0x60 kernel/sched/wait.c:146
       tty_port_default_wakeup+0x47/0x60 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x761/0xcb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0x9e/0x270 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0xf5/0x1d0 drivers/tty/serial/8250/8250_core.c:82
       __handle_irq_event_percpu+0x233/0x920 kernel/irq/handle.c:203
       handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
       handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
       handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:310 [inline]
       __common_interrupt+0xcd/0x2f0 arch/x86/kernel/irq.c:325
       common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
       _raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
       uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline]
       uart_port_unlock_deref drivers/tty/serial/serial_core.c:88 [inline]
       uart_write+0x2a4/0xb30 drivers/tty/serial/serial_core.c:634
       process_output_block drivers/tty/n_tty.c:561 [inline]
       n_tty_write+0x41b/0x11e0 drivers/tty/n_tty.c:2377
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write.constprop.0+0x503/0x9b0 drivers/tty/tty_io.c:1081
       tty_write drivers/tty/tty_io.c:1102 [inline]
       redirected_tty_write drivers/tty/tty_io.c:1125 [inline]
       redirected_tty_write+0xd4/0x150 drivers/tty/tty_io.c:1105
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x7d0/0x11d0 fs/read_write.c:686
       ksys_write+0x12a/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x181/0x1890 drivers/tty/serial/8250/8250_port.c:3301
       console_emit_next_record kernel/printk/printk.c:3111 [inline]
       console_flush_all+0x801/0xc60 kernel/printk/printk.c:3199
       __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
       vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
       _printk+0xc7/0x100 kernel/printk/printk.c:2448
       register_console+0xc2d/0x11b0 kernel/printk/printk.c:4099
       univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:511
       console_init+0x14f/0x680 kernel/printk/printk.c:4298
       start_kernel+0x29f/0x4e0 init/main.c:1048
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x148

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
       console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1897
       console_emit_next_record kernel/printk/printk.c:3105 [inline]
       console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3199
       __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
       vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
       _printk+0xc7/0x100 kernel/printk/printk.c:2448
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174
       strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:214 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:309 [inline]
       bpf_probe_read_compat_str+0xe8/0x180 kernel/trace/bpf_trace.c:305
       bpf_prog_d8259690ea4df48b+0x41/0x47
       bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
       __bpf_prog_run include/linux/filter.h:721 [inline]
       bpf_prog_run include/linux/filter.h:728 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
       bpf_trace_run4+0x24f/0x5b0 kernel/trace/bpf_trace.c:2118
       __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220
       __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220
       __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
       trace_sched_switch include/trace/events/sched.h:220 [inline]
       __schedule+0x183b/0x5de0 kernel/sched/core.c:6926
       preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
       irqentry_exit+0x36/0x90 kernel/entry/common.c:211
       asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
       task_nice_ioclass include/linux/ioprio.h:41 [inline]
       __get_task_ioprio include/linux/ioprio.h:71 [inline]
       get_current_ioprio include/linux/ioprio.h:84 [inline]
       init_sync_kiocb include/linux/fs.h:2596 [inline]
       seq_read+0x262/0x570 fs/seq_file.c:158
       pde_read fs/proc/inode.c:308 [inline]
       proc_reg_read+0x23d/0x330 fs/proc/inode.c:320
       do_loop_readv_writev fs/read_write.c:847 [inline]
       do_loop_readv_writev fs/read_write.c:835 [inline]
       vfs_readv+0x5c1/0x8b0 fs/read_write.c:1020
       do_preadv+0x1a6/0x270 fs/read_write.c:1132
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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 ***

4 locks held by syz.4.9452/9872:
 #0: ffff8880b863a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
 #0: ffff8880b863a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
 #1: ffffffff8e1c43a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #1: ffffffff8e1c43a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #1: ffffffff8e1c43a0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline]
 #1: ffffffff8e1c43a0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d5/0x5b0 kernel/trace/bpf_trace.c:2118
 #2: ffffffff8e1b1a00 (console_lock){+.+.}-{0:0}, at: _printk+0xc7/0x100 kernel/printk/printk.c:2448
 #3: ffffffff8e1b1a70 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #3: ffffffff8e1b1a70 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:335 [inline]
 #3: ffffffff8e1b1a70 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
 #3: ffffffff8e1b1a70 (console_srcu){....}-{0:0}, at: console_flush_all+0x158/0xc60 kernel/printk/printk.c:3176

stack backtrace:
CPU: 1 UID: 0 PID: 9872 Comm: syz.4.9452 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
 console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1897
 console_emit_next_record kernel/printk/printk.c:3105 [inline]
 console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3199
 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
 console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
 vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
 _printk+0xc7/0x100 kernel/printk/printk.c:2448
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:214 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:309 [inline]
 bpf_probe_read_compat_str+0xe8/0x180 kernel/trace/bpf_trace.c:305
 bpf_prog_d8259690ea4df48b+0x41/0x47
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run4+0x24f/0x5b0 kernel/trace/bpf_trace.c:2118
 __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220
 __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x183b/0x5de0 kernel/sched/core.c:6926
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:task_nice_ioclass include/linux/ioprio.h:41 [inline]
RIP: 0010:__get_task_ioprio include/linux/ioprio.h:71 [inline]
RIP: 0010:get_current_ioprio include/linux/ioprio.h:84 [inline]
RIP: 0010:init_sync_kiocb include/linux/fs.h:2596 [inline]
RIP: 0010:seq_read+0x262/0x570 fs/seq_file.c:158
Code: 00 00 00 fc ff df 89 54 24 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 eb 02 00 00 <45> 8b a4 24 4c 04 00 00 bf 05 00 00 00 44 89 e6 e8 b9 ec 78 ff 41
RSP: 0018:ffffc90003f8faf8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 1ffff920007f1f61 RCX: ffffc90003f8feb0
RDX: 0000000000000000 RSI: ffffffff8242d3a7 RDI: ffff88803c8dcd4c
RBP: ffffc90003f8feb0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88803c8dc900
R13: ffff888065ed8c40 R14: 00000000000000fa R15: 0000000000000000
 pde_read fs/proc/inode.c:308 [inline]
 proc_reg_read+0x23d/0x330 fs/proc/inode.c:320
 do_loop_readv_writev fs/read_write.c:847 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_readv+0x5c1/0x8b0 fs/read_write.c:1020
 do_preadv+0x1a6/0x270 fs/read_write.c:1132
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5de318eec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5de3f5b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f5de33e6180 RCX: 00007f5de318eec9
RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007f5de3f5b090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000185 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5de33e6218 R14: 00007f5de33e6180 R15: 00007ffc518f9888
 </TASK>
CPU: 1 UID: 0 PID: 9872 Comm: syz.4.9452 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x512/0x640 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:214 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:309 [inline]
 bpf_probe_read_compat_str+0xe8/0x180 kernel/trace/bpf_trace.c:305
 bpf_prog_d8259690ea4df48b+0x41/0x47
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run4+0x24f/0x5b0 kernel/trace/bpf_trace.c:2118
 __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220
 __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x183b/0x5de0 kernel/sched/core.c:6926
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:task_nice_ioclass include/linux/ioprio.h:41 [inline]
RIP: 0010:__get_task_ioprio include/linux/ioprio.h:71 [inline]
RIP: 0010:get_current_ioprio include/linux/ioprio.h:84 [inline]
RIP: 0010:init_sync_kiocb include/linux/fs.h:2596 [inline]
RIP: 0010:seq_read+0x262/0x570 fs/seq_file.c:158
Code: 00 00 00 fc ff df 89 54 24 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 eb 02 00 00 <45> 8b a4 24 4c 04 00 00 bf 05 00 00 00 44 89 e6 e8 b9 ec 78 ff 41
RSP: 0018:ffffc90003f8faf8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 1ffff920007f1f61 RCX: ffffc90003f8feb0
RDX: 0000000000000000 RSI: ffffffff8242d3a7 RDI: ffff88803c8dcd4c
RBP: ffffc90003f8feb0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88803c8dc900
R13: ffff888065ed8c40 R14: 00000000000000fa R15: 0000000000000000
 pde_read fs/proc/inode.c:308 [inline]
 proc_reg_read+0x23d/0x330 fs/proc/inode.c:320
 do_loop_readv_writev fs/read_write.c:847 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_readv+0x5c1/0x8b0 fs/read_write.c:1020
 do_preadv+0x1a6/0x270 fs/read_write.c:1132
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5de318eec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5de3f5b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f5de33e6180 RCX: 00007f5de318eec9
RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007f5de3f5b090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000185 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5de33e6218 R14: 00007f5de33e6180 R15: 00007ffc518f9888
 </TASK>
----------------
Code disassembly (best guess), 5 bytes skipped:
   0:	df 89 54 24 0c 48    	fisttps 0x480c2454(%rcx)
   6:	89 fa                	mov    %edi,%edx
   8:	48 c1 ea 03          	shr    $0x3,%rdx
   c:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
  10:	48 89 f8             	mov    %rdi,%rax
  13:	83 e0 07             	and    $0x7,%eax
  16:	83 c0 03             	add    $0x3,%eax
  19:	38 d0                	cmp    %dl,%al
  1b:	7c 08                	jl     0x25
  1d:	84 d2                	test   %dl,%dl
  1f:	0f 85 eb 02 00 00    	jne    0x310
* 25:	45 8b a4 24 4c 04 00 	mov    0x44c(%r12),%r12d <-- trapping instruction
  2c:	00
  2d:	bf 05 00 00 00       	mov    $0x5,%edi
  32:	44 89 e6             	mov    %r12d,%esi
  35:	e8 b9 ec 78 ff       	call   0xff78ecf3
  3a:	41                   	rex.B