option from the mount to silence this warning.
=======================================================
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.0.0-next-20221006 #1 Not tainted
------------------------------------------------------
syz-executor.3/10309 is trying to acquire lock:
ffffffff853fac98 ((console_sem).lock){....}-{2:2}, at: down_trylock+0xe/0x70
but task is already holding lock:
ffff8880092a7020 (&ctx->lock){....}-{2:2}, at: __perf_event_task_sched_out+0x53b/0x18d0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ctx->lock){....}-{2:2}:
_raw_spin_lock+0x2a/0x40
__perf_event_task_sched_out+0x53b/0x18d0
__schedule+0xedd/0x2470
preempt_schedule_common+0x45/0xc0
__cond_resched+0x17/0x30
__mutex_lock+0xa3/0x14d0
__do_sys_perf_event_open+0x1eec/0x32c0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #2 (&rq->__lock){-.-.}-{2:2}:
_raw_spin_lock_nested+0x30/0x40
raw_spin_rq_lock_nested+0x1e/0x30
task_fork_fair+0x63/0x4d0
sched_cgroup_fork+0x3d0/0x540
copy_process+0x4183/0x6e20
kernel_clone+0xe7/0x890
user_mode_thread+0xad/0xf0
rest_init+0x24/0x250
arch_call_rest_init+0xf/0x14
start_kernel+0x4c6/0x4eb
secondary_startup_64_no_verify+0xe0/0xeb
-> #1 (&p->pi_lock){-.-.}-{2:2}:
_raw_spin_lock_irqsave+0x39/0x60
try_to_wake_up+0xab/0x1930
up+0x75/0xb0
__up_console_sem+0x6e/0x80
console_unlock+0x46a/0x590
do_con_write+0xc05/0x1d50
con_write+0x21/0x40
n_tty_write+0x4d4/0xfe0
file_tty_write.constprop.0+0x455/0x8a0
vfs_write+0x9c3/0xd90
ksys_write+0x127/0x250
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #0 ((console_sem).lock){....}-{2:2}:
__lock_acquire+0x2a02/0x5e70
lock_acquire+0x1a2/0x530
_raw_spin_lock_irqsave+0x39/0x60
down_trylock+0xe/0x70
__down_trylock_console_sem+0x3b/0xd0
vprintk_emit+0x16b/0x560
vprintk+0x84/0xa0
_printk+0xba/0xf1
report_bug.cold+0x72/0xab
handle_bug+0x3c/0x70
exc_invalid_op+0x14/0x50
asm_exc_invalid_op+0x16/0x20
group_sched_out.part.0+0x2c7/0x460
ctx_sched_out+0x8f1/0xc10
__perf_event_task_sched_out+0x6d0/0x18d0
__schedule+0xedd/0x2470
preempt_schedule_common+0x45/0xc0
__cond_resched+0x17/0x30
__mutex_lock+0xa3/0x14d0
__do_sys_perf_event_open+0x1eec/0x32c0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
other info that might help us debug this:
Chain exists of:
(console_sem).lock --> &rq->__lock --> &ctx->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ctx->lock);
lock(&rq->__lock);
lock(&ctx->lock);
lock((console_sem).lock);
*** DEADLOCK ***
2 locks held by syz-executor.3/10309:
#0: ffff88806cf37e98 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x1cf/0x2470
#1: ffff8880092a7020 (&ctx->lock){....}-{2:2}, at: __perf_event_task_sched_out+0x53b/0x18d0
stack backtrace:
CPU: 1 PID: 10309 Comm: syz-executor.3 Not tainted 6.0.0-next-20221006 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0x8b/0xb3
check_noncircular+0x263/0x2e0
__lock_acquire+0x2a02/0x5e70
lock_acquire+0x1a2/0x530
_raw_spin_lock_irqsave+0x39/0x60
down_trylock+0xe/0x70
__down_trylock_console_sem+0x3b/0xd0
vprintk_emit+0x16b/0x560
vprintk+0x84/0xa0
_printk+0xba/0xf1
report_bug.cold+0x72/0xab
handle_bug+0x3c/0x70
exc_invalid_op+0x14/0x50
asm_exc_invalid_op+0x16/0x20
RIP: 0010:group_sched_out.part.0+0x2c7/0x460
Code: 5e 41 5f e9 5b a5 ef ff e8 56 a5 ef ff 65 8b 1d 1b fe ab 7e 31 ff 89 de e8 f6 a1 ef ff 85 db 0f 84 8a 00 00 00 e8 39 a5 ef ff <0f> 0b e9 a5 fe ff ff e8 2d a5 ef ff 48 8d 7d 10 48 b8 00 00 00 00
RSP: 0018:ffff888040627978 EFLAGS: 00010006
RAX: 0000000040000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88800ff95040 RSI: ffffffff815677b7 RDI: 0000000000000005
RBP: ffff8880407d8000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880092a7000
R13: ffff88806cf3d2c0 R14: ffffffff8547cb60 R15: 0000000000000002
ctx_sched_out+0x8f1/0xc10
__perf_event_task_sched_out+0x6d0/0x18d0
__schedule+0xedd/0x2470
preempt_schedule_common+0x45/0xc0
__cond_resched+0x17/0x30
__mutex_lock+0xa3/0x14d0
__do_sys_perf_event_open+0x1eec/0x32c0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f705aa25b19
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:00007f7057f9b188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f705ab38f60 RCX: 00007f705aa25b19
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f705aa7ff6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8cd5587f R14: 00007f7057f9b300 R15: 0000000000022000
WARNING: CPU: 1 PID: 10309 at kernel/events/core.c:2309 group_sched_out.part.0+0x2c7/0x460
Modules linked in:
CPU: 1 PID: 10309 Comm: syz-executor.3 Not tainted 6.0.0-next-20221006 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:group_sched_out.part.0+0x2c7/0x460
Code: 5e 41 5f e9 5b a5 ef ff e8 56 a5 ef ff 65 8b 1d 1b fe ab 7e 31 ff 89 de e8 f6 a1 ef ff 85 db 0f 84 8a 00 00 00 e8 39 a5 ef ff <0f> 0b e9 a5 fe ff ff e8 2d a5 ef ff 48 8d 7d 10 48 b8 00 00 00 00
RSP: 0018:ffff888040627978 EFLAGS: 00010006
RAX: 0000000040000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88800ff95040 RSI: ffffffff815677b7 RDI: 0000000000000005
RBP: ffff8880407d8000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880092a7000
R13: ffff88806cf3d2c0 R14: ffffffff8547cb60 R15: 0000000000000002
FS: 00007f7057f9b700(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001d40 CR3: 000000003137e000 CR4: 0000000000350ee0
Call Trace:
ctx_sched_out+0x8f1/0xc10
__perf_event_task_sched_out+0x6d0/0x18d0
__schedule+0xedd/0x2470
preempt_schedule_common+0x45/0xc0
__cond_resched+0x17/0x30
__mutex_lock+0xa3/0x14d0
__do_sys_perf_event_open+0x1eec/0x32c0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f705aa25b19
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:00007f7057f9b188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f705ab38f60 RCX: 00007f705aa25b19
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f705aa7ff6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc8cd5587f R14: 00007f7057f9b300 R15: 0000000000022000
irq event stamp: 1946
hardirqs last enabled at (1945): [] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (1946): [] __schedule+0x1225/0x2470
softirqs last enabled at (1934): [] __irq_exit_rcu+0x11b/0x180
softirqs last disabled at (1921): [] __irq_exit_rcu+0x11b/0x180
---[ end trace 0000000000000000 ]---
hrtimer: interrupt took 14918 ns
loop2: detected capacity change from 0 to 264192
audit: type=1400 audit(1665131002.152:9): avc: denied { write } for pid=10323 comm="syz-executor.0" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=perf_event permissive=1