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From: Dmitry Vyukov <dvyukov@google.com>
To: Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	alsa-devel@alsa-project.org, LKML <linux-kernel@vger.kernel.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Subject: sound: another deadlock in snd_seq_pool_done
Date: Sat, 4 Mar 2017 17:31:21 +0100	[thread overview]
Message-ID: <CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com> (raw)

Hello,

The following program creates processes deadlocked in snd_seq_pool_done:

https://gist.githubusercontent.com/dvyukov/97efc9cb6d63b1b2c7b737b82cc8b0d6/raw/3546b133ae0b2d3e1190ae7c1f4e240ce7ce132e/gistfile1.txt

After few seconds I get:

# ps afxu | grep a.out
root      8660  2.0  0.0      0     0 pts/0    Zl   16:27   0:00
[a.out] <defunct>

# kill -9 8660

# cat /proc/8660/status
Name: a.out
State: Z (zombie)
Tgid: 8660
Ngid: 0
Pid: 8660
PPid: 1
TracerPid: 0
Uid: 0 0 0 0
Gid: 0 0 0 0
FDSize: 0
Groups: 0
NStgid: 8660
NSpid: 8660
NSpgid: 8660
NSsid: 2971
Threads: 2
SigQ: 1/3304
SigPnd: 0000000000000000
ShdPnd: 0000000000000100
SigBlk: 0000000000000000
SigIgn: 0000000180000000
SigCgt: 0000000000000440
CapInh: 0000000000000000
CapPrm: 0000003fffffffff
CapEff: 0000003fffffffff
CapBnd: 0000003fffffffff
CapAmb: 0000000000000000
NoNewPrivs: 0
Seccomp: 0
Cpus_allowed: f
Cpus_allowed_list: 0-3
Mems_allowed: 00000000,00000001
Mems_allowed_list: 0
voluntary_ctxt_switches: 12
nonvoluntary_ctxt_switches: 0

# cat /proc/8660/task/*/stack
[<ffffffff835406db>] snd_seq_pool_done+0x31b/0x620
sound/core/seq/seq_memory.c:436
[<ffffffff8353a11e>] snd_seq_ioctl_set_client_pool+0x1ae/0x600
sound/core/seq/seq_clientmgr.c:1836
[<ffffffff835382ba>] snd_seq_ioctl+0x2da/0x4d0
sound/core/seq/seq_clientmgr.c:2130
[<ffffffff81aced2f>] vfs_ioctl fs/ioctl.c:45 [inline]
[<ffffffff81aced2f>] do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:685
[<ffffffff81ad038f>] SYSC_ioctl fs/ioctl.c:700 [inline]
[<ffffffff81ad038f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
[<ffffffff8457dc41>] entry_SYSCALL_64_fastpath+0x1f/0xc2

             reply	other threads:[~2017-03-04 16:32 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-04 16:31 Dmitry Vyukov [this message]
2017-03-10  9:19 ` sound: another deadlock in snd_seq_pool_done Dmitry Vyukov
2017-03-20  7:17   ` Takashi Iwai
2017-03-20  7:17     ` Takashi Iwai
2017-03-20  9:01     ` Dmitry Vyukov
2017-03-20  9:01       ` Dmitry Vyukov
2017-03-21 12:23 ` Takashi Iwai
2017-03-21 12:23   ` Takashi Iwai
2017-03-21 12:48   ` Dmitry Vyukov
2017-03-21 12:48     ` Dmitry Vyukov
2017-03-21 13:02     ` Takashi Iwai
2017-03-21 13:02       ` Takashi Iwai

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