* INFO: rcu detected stall in __snd_pcm_lib_xfer (2)
@ 2018-04-06 7:08 syzbot
2018-04-06 12:52 ` Takashi Iwai
2018-04-10 1:39 ` syzbot
0 siblings, 2 replies; 4+ messages in thread
From: syzbot @ 2018-04-06 7:08 UTC (permalink / raw)
To: alsa-devel, linux-kernel, o-takashi, perex, syzkaller-bugs, tiwai
Hello,
syzbot hit the following crash on upstream commit
e02d37bf55a9a36f22427fd6dd733fe104d817b6 (Thu Apr 5 17:42:07 2018 +0000)
Merge tag 'sound-4.17-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=7e3f31a52646f939c052
So far this crash happened 43 times on upstream.
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5148264345108480
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-4805825610197092128
compiler: gcc (GCC) 8.0.1 20180301 (experimental)
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.
INFO: rcu_sched self-detected stall on CPU
1-...!: (124999 ticks this GP) idle=522/1/4611686018427387906
softirq=65432/65432 fqs=169
(t=125000 jiffies g=35384 c=35383 q=537)
rcu_sched kthread starved for 124294 jiffies! g35384 c35383 f0x0
RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
RCU grace-period kthread stack dump:
rcu_sched R running task 23768 9 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2848 [inline]
__schedule+0x807/0x1e40 kernel/sched/core.c:3490
schedule+0xef/0x430 kernel/sched/core.c:3549
schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
kthread+0x345/0x410 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
NMI backtrace for cpu 1
CPU: 1 PID: 15299 Comm: syz-executor3 Not tainted 4.16.0+ #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b9/0x29f lib/dump_stack.c:53
nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
print_cpu_stall kernel/rcu/tree.c:1525 [inline]
check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
__rcu_pending kernel/rcu/tree.c:3356 [inline]
rcu_pending kernel/rcu/tree.c:3401 [inline]
rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
update_process_times+0x2d/0x70 kernel/time/timer.c:1636
tick_sched_handle+0xa0/0x180 kernel/time/tick-sched.c:171
tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
__run_hrtimer kernel/time/hrtimer.c:1337 [inline]
__hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
</IRQ>
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:793 [inline]
RIP: 0010:snd_pcm_stream_unlock_irq+0xb7/0xf0 sound/core/pcm_native.c:166
RSP: 0018:ffff8801c3f27560 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900038d5000
RDX: 0000000000040000 RSI: ffffffff859ca760 RDI: ffffffff88b172b8
RBP: ffff8801c3f27568 R08: ffff8801abf86af8 R09: 0000000000000006
R10: ffff8801abf86280 R11: 0000000000000000 R12: 0000000000000004
R13: 00000000ffffffe0 R14: ffff8801d7d9e1c0 R15: ffff8801ceac6940
__snd_pcm_lib_xfer+0x739/0x1d10 sound/core/pcm_lib.c:2246
snd_pcm_oss_write3+0xe9/0x220 sound/core/oss/pcm_oss.c:1236
io_playback_transfer+0x274/0x310 sound/core/oss/io.c:47
snd_pcm_plug_write_transfer+0x36c/0x470 sound/core/oss/pcm_plugin.c:619
snd_pcm_oss_write2+0x25c/0x460 sound/core/oss/pcm_oss.c:1365
snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1415 [inline]
snd_pcm_oss_write+0x764/0xa20 sound/core/oss/pcm_oss.c:2774
__vfs_write+0x10b/0x880 fs/read_write.c:485
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0xf9/0x250 fs/read_write.c:598
SYSC_write fs/read_write.c:610 [inline]
SyS_write+0x24/0x30 fs/read_write.c:607
do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4552d9
RSP: 002b:00007f1568de6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1568de76d4 RCX: 00000000004552d9
RDX: 0000000000000060 RSI: 0000000020000000 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006c0 R14: 00000000006fd2a0 R15: 0000000000000000
---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzkaller@googlegroups.com.
syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: INFO: rcu detected stall in __snd_pcm_lib_xfer (2)
2018-04-06 7:08 INFO: rcu detected stall in __snd_pcm_lib_xfer (2) syzbot
@ 2018-04-06 12:52 ` Takashi Iwai
2018-04-06 13:21 ` Dmitry Vyukov
2018-04-10 1:39 ` syzbot
1 sibling, 1 reply; 4+ messages in thread
From: Takashi Iwai @ 2018-04-06 12:52 UTC (permalink / raw)
To: syzbot; +Cc: alsa-devel, syzkaller-bugs, perex, o-takashi, linux-kernel
On Fri, 06 Apr 2018 09:08:01 +0200,
syzbot wrote:
>
> Hello,
>
> syzbot hit the following crash on upstream commit
> e02d37bf55a9a36f22427fd6dd733fe104d817b6 (Thu Apr 5 17:42:07 2018 +0000)
> Merge tag 'sound-4.17-rc1' of
> git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
> syzbot dashboard link:
> https://syzkaller.appspot.com/bug?extid=7e3f31a52646f939c052
>
> So far this crash happened 43 times on upstream.
> Unfortunately, I don't have any reproducer for this crash yet.
> Raw console output:
> https://syzkaller.appspot.com/x/log.txt?id=5148264345108480
> Kernel config:
> https://syzkaller.appspot.com/x/.config?id=-4805825610197092128
> compiler: gcc (GCC) 8.0.1 20180301 (experimental)
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com
> It will help syzbot understand when the bug is fixed. See footer for
> details.
> If you forward the report, please keep this part and the footer.
>
> INFO: rcu_sched self-detected stall on CPU
> 1-...!: (124999 ticks this GP) idle=522/1/4611686018427387906
> softirq=65432/65432 fqs=169
> (t=125000 jiffies g=35384 c=35383 q=537)
> rcu_sched kthread starved for 124294 jiffies! g35384 c35383 f0x0
> RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
> RCU grace-period kthread stack dump:
> rcu_sched R running task 23768 9 2 0x80000000
> Call Trace:
> context_switch kernel/sched/core.c:2848 [inline]
> __schedule+0x807/0x1e40 kernel/sched/core.c:3490
> schedule+0xef/0x430 kernel/sched/core.c:3549
> schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
> rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
> kthread+0x345/0x410 kernel/kthread.c:238
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
> NMI backtrace for cpu 1
> CPU: 1 PID: 15299 Comm: syz-executor3 Not tainted 4.16.0+ #2
> Hardware name: Google Google Compute Engine/Google Compute Engine,
> BIOS Google 01/01/2011
> Call Trace:
> <IRQ>
> __dump_stack lib/dump_stack.c:17 [inline]
> dump_stack+0x1b9/0x29f lib/dump_stack.c:53
> nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
> nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
> trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
> rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
> print_cpu_stall kernel/rcu/tree.c:1525 [inline]
> check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
> __rcu_pending kernel/rcu/tree.c:3356 [inline]
> rcu_pending kernel/rcu/tree.c:3401 [inline]
> rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
> update_process_times+0x2d/0x70 kernel/time/timer.c:1636
> tick_sched_handle+0xa0/0x180 kernel/time/tick-sched.c:171
> tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
> __run_hrtimer kernel/time/hrtimer.c:1337 [inline]
> __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
> hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
> smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
> </IRQ>
> RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:793 [inline]
> RIP: 0010:snd_pcm_stream_unlock_irq+0xb7/0xf0 sound/core/pcm_native.c:166
> RSP: 0018:ffff8801c3f27560 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900038d5000
> RDX: 0000000000040000 RSI: ffffffff859ca760 RDI: ffffffff88b172b8
> RBP: ffff8801c3f27568 R08: ffff8801abf86af8 R09: 0000000000000006
> R10: ffff8801abf86280 R11: 0000000000000000 R12: 0000000000000004
> R13: 00000000ffffffe0 R14: ffff8801d7d9e1c0 R15: ffff8801ceac6940
> __snd_pcm_lib_xfer+0x739/0x1d10 sound/core/pcm_lib.c:2246
> snd_pcm_oss_write3+0xe9/0x220 sound/core/oss/pcm_oss.c:1236
> io_playback_transfer+0x274/0x310 sound/core/oss/io.c:47
> snd_pcm_plug_write_transfer+0x36c/0x470 sound/core/oss/pcm_plugin.c:619
> snd_pcm_oss_write2+0x25c/0x460 sound/core/oss/pcm_oss.c:1365
> snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1415 [inline]
> snd_pcm_oss_write+0x764/0xa20 sound/core/oss/pcm_oss.c:2774
> __vfs_write+0x10b/0x880 fs/read_write.c:485
> vfs_write+0x1f8/0x560 fs/read_write.c:549
> ksys_write+0xf9/0x250 fs/read_write.c:598
> SYSC_write fs/read_write.c:610 [inline]
> SyS_write+0x24/0x30 fs/read_write.c:607
> do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
> entry_SYSCALL_64_after_hwframe+0x42/0xb7
> RIP: 0033:0x4552d9
> RSP: 002b:00007f1568de6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 00007f1568de76d4 RCX: 00000000004552d9
> RDX: 0000000000000060 RSI: 0000000020000000 RDI: 0000000000000013
> RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
> R13: 00000000000006c0 R14: 00000000006fd2a0 R15: 0000000000000000
Hmm, a problem that appears like the issue we've already fixed strikes
back. Maybe because of the recent my code change for further
hardening of PCM OSS.
If there is a reproducer, I'd take a deeper look, but currently I
couldn't see the obvious cause, and all reproducers in the past seem
working. So if you get any reproducer, please let me know.
There are a couple of pending small fixes that might cure this, and
I'm going to submit & merge before 4.17-rc1, in anyway.
thanks,
Takashi
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: INFO: rcu detected stall in __snd_pcm_lib_xfer (2)
2018-04-06 12:52 ` Takashi Iwai
@ 2018-04-06 13:21 ` Dmitry Vyukov
0 siblings, 0 replies; 4+ messages in thread
From: Dmitry Vyukov @ 2018-04-06 13:21 UTC (permalink / raw)
To: Takashi Iwai
Cc: syzbot, alsa-devel, syzkaller-bugs, Jaroslav Kysela,
Takashi Sakamoto, LKML
On Fri, Apr 6, 2018 at 2:52 PM, Takashi Iwai <tiwai@suse.de> wrote:
> On Fri, 06 Apr 2018 09:08:01 +0200,
> syzbot wrote:
>>
>> Hello,
>>
>> syzbot hit the following crash on upstream commit
>> e02d37bf55a9a36f22427fd6dd733fe104d817b6 (Thu Apr 5 17:42:07 2018 +0000)
>> Merge tag 'sound-4.17-rc1' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
>> syzbot dashboard link:
>> https://syzkaller.appspot.com/bug?extid=7e3f31a52646f939c052
>>
>> So far this crash happened 43 times on upstream.
>> Unfortunately, I don't have any reproducer for this crash yet.
>> Raw console output:
>> https://syzkaller.appspot.com/x/log.txt?id=5148264345108480
>> Kernel config:
>> https://syzkaller.appspot.com/x/.config?id=-4805825610197092128
>> compiler: gcc (GCC) 8.0.1 20180301 (experimental)
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com
>> It will help syzbot understand when the bug is fixed. See footer for
>> details.
>> If you forward the report, please keep this part and the footer.
>>
>> INFO: rcu_sched self-detected stall on CPU
>> 1-...!: (124999 ticks this GP) idle=522/1/4611686018427387906
>> softirq=65432/65432 fqs=169
>> (t=125000 jiffies g=35384 c=35383 q=537)
>> rcu_sched kthread starved for 124294 jiffies! g35384 c35383 f0x0
>> RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
>> RCU grace-period kthread stack dump:
>> rcu_sched R running task 23768 9 2 0x80000000
>> Call Trace:
>> context_switch kernel/sched/core.c:2848 [inline]
>> __schedule+0x807/0x1e40 kernel/sched/core.c:3490
>> schedule+0xef/0x430 kernel/sched/core.c:3549
>> schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
>> rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
>> kthread+0x345/0x410 kernel/kthread.c:238
>> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
>> NMI backtrace for cpu 1
>> CPU: 1 PID: 15299 Comm: syz-executor3 Not tainted 4.16.0+ #2
>> Hardware name: Google Google Compute Engine/Google Compute Engine,
>> BIOS Google 01/01/2011
>> Call Trace:
>> <IRQ>
>> __dump_stack lib/dump_stack.c:17 [inline]
>> dump_stack+0x1b9/0x29f lib/dump_stack.c:53
>> nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
>> nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
>> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
>> trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
>> rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
>> print_cpu_stall kernel/rcu/tree.c:1525 [inline]
>> check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
>> __rcu_pending kernel/rcu/tree.c:3356 [inline]
>> rcu_pending kernel/rcu/tree.c:3401 [inline]
>> rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
>> update_process_times+0x2d/0x70 kernel/time/timer.c:1636
>> tick_sched_handle+0xa0/0x180 kernel/time/tick-sched.c:171
>> tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
>> __run_hrtimer kernel/time/hrtimer.c:1337 [inline]
>> __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
>> hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
>> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
>> smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
>> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
>> </IRQ>
>> RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:793 [inline]
>> RIP: 0010:snd_pcm_stream_unlock_irq+0xb7/0xf0 sound/core/pcm_native.c:166
>> RSP: 0018:ffff8801c3f27560 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
>> RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900038d5000
>> RDX: 0000000000040000 RSI: ffffffff859ca760 RDI: ffffffff88b172b8
>> RBP: ffff8801c3f27568 R08: ffff8801abf86af8 R09: 0000000000000006
>> R10: ffff8801abf86280 R11: 0000000000000000 R12: 0000000000000004
>> R13: 00000000ffffffe0 R14: ffff8801d7d9e1c0 R15: ffff8801ceac6940
>> __snd_pcm_lib_xfer+0x739/0x1d10 sound/core/pcm_lib.c:2246
>> snd_pcm_oss_write3+0xe9/0x220 sound/core/oss/pcm_oss.c:1236
>> io_playback_transfer+0x274/0x310 sound/core/oss/io.c:47
>> snd_pcm_plug_write_transfer+0x36c/0x470 sound/core/oss/pcm_plugin.c:619
>> snd_pcm_oss_write2+0x25c/0x460 sound/core/oss/pcm_oss.c:1365
>> snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1415 [inline]
>> snd_pcm_oss_write+0x764/0xa20 sound/core/oss/pcm_oss.c:2774
>> __vfs_write+0x10b/0x880 fs/read_write.c:485
>> vfs_write+0x1f8/0x560 fs/read_write.c:549
>> ksys_write+0xf9/0x250 fs/read_write.c:598
>> SYSC_write fs/read_write.c:610 [inline]
>> SyS_write+0x24/0x30 fs/read_write.c:607
>> do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
>> entry_SYSCALL_64_after_hwframe+0x42/0xb7
>> RIP: 0033:0x4552d9
>> RSP: 002b:00007f1568de6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
>> RAX: ffffffffffffffda RBX: 00007f1568de76d4 RCX: 00000000004552d9
>> RDX: 0000000000000060 RSI: 0000000020000000 RDI: 0000000000000013
>> RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
>> R13: 00000000000006c0 R14: 00000000006fd2a0 R15: 0000000000000000
>
> Hmm, a problem that appears like the issue we've already fixed strikes
> back. Maybe because of the recent my code change for further
> hardening of PCM OSS.
>
> If there is a reproducer, I'd take a deeper look, but currently I
> couldn't see the obvious cause, and all reproducers in the past seem
> working. So if you get any reproducer, please let me know.
>
> There are a couple of pending small fixes that might cure this, and
> I'm going to submit & merge before 4.17-rc1, in anyway.
Hi Takashi,
syzbot will notify when/if a reproducer is available.
It happens pretty actively, so if it is cured by any commits, we will
see it stop happening here:
https://syzkaller.appspot.com/bug?extid=7e3f31a52646f939c052
There is also a bunch of similarly looking rcu stalls (also in sound
and started happening all at once):
https://syzkaller.appspot.com/bug?id=f087e17667da6944617675babc90277bc5a7b34e
https://syzkaller.appspot.com/bug?id=55381513d03b0098c2905ae1a48b4cc7c3b25a22
https://syzkaller.appspot.com/bug?id=f9364472bcbd3cb1738f774dd3711668cb402216
With high probability it is something that was just merged upstream.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: INFO: rcu detected stall in __snd_pcm_lib_xfer (2)
2018-04-06 7:08 INFO: rcu detected stall in __snd_pcm_lib_xfer (2) syzbot
2018-04-06 12:52 ` Takashi Iwai
@ 2018-04-10 1:39 ` syzbot
1 sibling, 0 replies; 4+ messages in thread
From: syzbot @ 2018-04-10 1:39 UTC (permalink / raw)
To: alsa-devel-bounces, alsa-devel, dvyukov, linux-kernel, o-takashi,
perex, syzkaller-bugs, tiwai, tiwai
syzbot has found reproducer for the following crash on upstream commit
fd40ffc72e2f74c7db61e400903e7d50a88bc0b0 (Mon Apr 9 18:36:05 2018 +0000)
selinux: fix missing dput() before selinuxfs unmount
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=7e3f31a52646f939c052
So far this crash happened 731 times on upstream.
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5746654556717056
syzkaller reproducer:
https://syzkaller.appspot.com/x/repro.syz?id=5437811310198784
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5066563195502592
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-771321277174894814
compiler: gcc (GCC) 8.0.1 20180301 (experimental)
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed.
INFO: rcu_sched self-detected stall on CPU
0-....: (124999 ticks this GP) idle=1f2/1/4611686018427387906
softirq=10492/10492 fqs=31246
(t=125000 jiffies g=4909 c=4908 q=3)
NMI backtrace for cpu 0
CPU: 0 PID: 4481 Comm: syzkaller419220 Not tainted 4.16.0+ #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
print_cpu_stall kernel/rcu/tree.c:1525 [inline]
check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
__rcu_pending kernel/rcu/tree.c:3356 [inline]
rcu_pending kernel/rcu/tree.c:3401 [inline]
rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
update_process_times+0x2d/0x70 kernel/time/timer.c:1636
tick_sched_handle+0xa0/0x180 kernel/time/tick-sched.c:171
tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
__run_hrtimer kernel/time/hrtimer.c:1337 [inline]
__hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
</IRQ>
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:793 [inline]
RIP: 0010:snd_pcm_stream_unlock_irq+0xb7/0xf0 sound/core/pcm_native.c:166
RSP: 0018:ffff8801ac8a6b60 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8801a89e2700 RBX: 0000000000000000 RCX: 1ffff1003513c5f3
RDX: 0000000000000000 RSI: ffffffff85a14e10 RDI: ffffffff88b17bf8
RBP: ffff8801ac8a6b68 R08: ffff8801a89e2f78 R09: 0000000000000006
R10: ffff8801a89e2700 R11: 0000000000000000 R12: 0000000000000004
R13: 00000000ffffffe0 R14: ffff8801d9a6ac00 R15: ffff8801ceb2f200
__snd_pcm_lib_xfer+0x739/0x1d10 sound/core/pcm_lib.c:2246
snd_pcm_oss_write3+0xe9/0x220 sound/core/oss/pcm_oss.c:1236
snd_pcm_oss_write2+0x34c/0x460 sound/core/oss/pcm_oss.c:1373
snd_pcm_oss_sync1+0x332/0x5a0 sound/core/oss/pcm_oss.c:1606
snd_pcm_oss_sync.isra.29+0x790/0x980 sound/core/oss/pcm_oss.c:1682
snd_pcm_oss_release+0x214/0x290 sound/core/oss/pcm_oss.c:2559
__fput+0x34d/0x890 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e4/0x290 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x1aee/0x2730 kernel/exit.c:865
do_group_exit+0x16f/0x430 kernel/exit.c:968
get_signal+0x886/0x1960 kernel/signal.c:2469
do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x449eb9
RSP: 002b:00007f302d286da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006dcc5c RCX: 0000000000449eb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dcc5c
RBP: 00000000006dcc58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0100000000000000
R13: 7073642f7665642f R14: 646e732f7665642f R15: 0000000000000009
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end of thread, other threads:[~2018-04-10 1:39 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-06 7:08 INFO: rcu detected stall in __snd_pcm_lib_xfer (2) syzbot
2018-04-06 12:52 ` Takashi Iwai
2018-04-06 13:21 ` Dmitry Vyukov
2018-04-10 1:39 ` syzbot
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