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authorTakashi Iwai <tiwai@suse.de>2016-05-10 16:07:40 +0200
committerTakashi Iwai <tiwai@suse.de>2016-05-10 17:05:16 +0200
commit8d879be882ba5a8bd4c2bc39bd2c336392564e13 (patch)
tree14d5315cd45c1cc60fa04cc8435cadaec5f25d9a /sound/core/pcm_lib.c
parent62f00e40b0718ebd8bd54fc7a9e89e873524d495 (diff)
ALSA: pcm: Bail out when chmap is already present
When snd_pcm_add_chmap_ctls() is called to the PCM stream to which a chmap has been already assigned, it returns as an error due to the conflicting snd_ctl_add() result. However, this also clears the already assigned chmap_kctl field via pcm_chmap_ctl_private_free(), and becomes inconsistent in the later operation. This patch adds the check of the conflicting chmap kctl before actually trying to allocate / assign. The check failure is treated as a kernel warning, as the double call of snd_pcm_add_chmap_ctls() is basically a driver bug and having the stack trace would help developers to figure out the bad code path. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/pcm_lib.c')
-rw-r--r--sound/core/pcm_lib.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 0aca39762ed0..bb1261591a1f 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -2595,6 +2595,8 @@ int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
};
int err;
+ if (WARN_ON(pcm->streams[stream].chmap_kctl))
+ return -EBUSY;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;