diff options
| author | Takashi Iwai <tiwai@suse.de> | 2016-01-31 10:32:37 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-17 12:30:59 -0800 |
| commit | 195988d298fc4c2af1162a960fd7772c311dc747 (patch) | |
| tree | 63cdfc5af79e1418342ce1bf3d41f36e0c290d92 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | f7fd4634b65c517321f1e7f30f5632d77b4208b4 (diff) | |
ALSA: pcm: Fix potential deadlock in OSS emulation
commit b248371628aad599a48540962f6b85a21a8a0c3f upstream.
There are potential deadlocks in PCM OSS emulation code while
accessing read/write and mmap concurrently. This comes from the
infamous mmap_sem usage in copy_from/to_user(). Namely,
snd_pcm_oss_write() ->
&runtime->oss.params_lock ->
copy_to_user() ->
&mm->mmap_sem
mmap() ->
&mm->mmap_sem ->
snd_pcm_oss_mmap() ->
&runtime->oss.params_lock
Since we can't avoid taking params_lock from mmap code path, use
trylock variant and aborts with -EAGAIN as a workaround of this AB/BA
deadlock.
BugLink: http://lkml.kernel.org/r/CACT4Y+bVrBKDG0G2_AcUgUQa+X91VKTeS4v+wN7BSHwHtqn3kQ@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions