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| author | Takashi Iwai <tiwai@suse.de> | 2019-04-15 09:03:01 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2019-04-15 12:04:31 +0200 |
| commit | b5fd12d6c0fc64c2c2b5ae095e63824083d27151 (patch) | |
| tree | 647c1b3d5b8f48e06e19ec148105438f3a6790c8 /sound/core | |
| parent | 46f5710f0b8829882faea735149d86250db5d0e5 (diff) | |
| download | blackbird-op-linux-b5fd12d6c0fc64c2c2b5ae095e63824083d27151.tar.gz blackbird-op-linux-b5fd12d6c0fc64c2c2b5ae095e63824083d27151.zip | |
ALSA: seq: Correct unlock sequence at snd_seq_client_ioctl_unlock()
The doubly unlock sequence at snd_seq_client_ioctl_unlock() is tricky.
I took a direct unref call since I thought it would avoid
misunderstanding, but rather this seems more confusing. Let's use
snd_seq_client_unlock() consistently even if they look strange to be
called twice, and add more comments for avoiding reader's confusion.
Fixes: 6b580f523172 ("ALSA: seq: Protect racy pool manipulation from OSS sequencer")
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/seq/seq_clientmgr.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 3acd80e718f2..c0227a672442 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -191,6 +191,7 @@ bool snd_seq_client_ioctl_lock(int clientid) if (!client) return false; mutex_lock(&client->ioctl_mutex); + /* The client isn't unrefed here; see snd_seq_client_ioctl_unlock() */ return true; } EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock); @@ -204,7 +205,11 @@ void snd_seq_client_ioctl_unlock(int clientid) if (WARN_ON(!client)) return; mutex_unlock(&client->ioctl_mutex); - snd_use_lock_free(&client->use_lock); + /* The doubly unrefs below are intentional; the first one releases the + * leftover from snd_seq_client_ioctl_lock() above, and the second one + * is for releasing snd_seq_client_use_ptr() in this function + */ + snd_seq_client_unlock(client); snd_seq_client_unlock(client); } EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock); |
