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author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-06-14 14:41:18 +0200 |
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committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-06-26 20:58:47 +0200 |
commit | 83ee87a31dc43a5fd6dee3562c146033c3a4cb39 (patch) | |
tree | 3c8070786261f4994209328901bda6b183077e3c /drivers/media | |
parent | V4L/DVB (8022): saa7134: fix race between opening and closing the device (diff) | |
download | linux-83ee87a31dc43a5fd6dee3562c146033c3a4cb39.tar.xz linux-83ee87a31dc43a5fd6dee3562c146033c3a4cb39.zip |
V4L/DVB (8026): Avoids an OOPS if dev struct can't be successfully recovered
On some alsa versions, it seems that snd_pcm_substream_chip(substream)
is returning a NULL pointer. This causes an OOPS, as reported by:
https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.24/+bug/212271
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/212960
This patch avoids the OOPS by not letting and open() succeed.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media')
-rw-r--r-- | drivers/media/video/cx88/cx88-alsa.c | 6 | ||||
-rw-r--r-- | drivers/media/video/em28xx/em28xx-audio.c | 6 | ||||
-rw-r--r-- | drivers/media/video/saa7134/saa7134-alsa.c | 8 |
3 files changed, 19 insertions, 1 deletions
diff --git a/drivers/media/video/cx88/cx88-alsa.c b/drivers/media/video/cx88/cx88-alsa.c index e976fc6bef7c..80c8883e54b5 100644 --- a/drivers/media/video/cx88/cx88-alsa.c +++ b/drivers/media/video/cx88/cx88-alsa.c @@ -332,6 +332,12 @@ static int snd_cx88_pcm_open(struct snd_pcm_substream *substream) struct snd_pcm_runtime *runtime = substream->runtime; int err; + if (!chip) { + printk(KERN_ERR "BUG: cx88 can't find device struct." + " Can't proceed with open\n"); + return -ENODEV; + } + err = snd_pcm_hw_constraint_pow2(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS); if (err < 0) goto _error; diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c index 343dff0f8a04..3c006103c1eb 100644 --- a/drivers/media/video/em28xx/em28xx-audio.c +++ b/drivers/media/video/em28xx/em28xx-audio.c @@ -268,6 +268,12 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream) dprintk("opening device and trying to acquire exclusive lock\n"); + if (!dev) { + printk(KERN_ERR "BUG: em28xx can't find device struct." + " Can't proceed with open\n"); + return -ENODEV; + } + /* Sets volume, mute, etc */ dev->mute = 0; diff --git a/drivers/media/video/saa7134/saa7134-alsa.c b/drivers/media/video/saa7134/saa7134-alsa.c index ba3082422a01..f118de6e3672 100644 --- a/drivers/media/video/saa7134/saa7134-alsa.c +++ b/drivers/media/video/saa7134/saa7134-alsa.c @@ -613,9 +613,15 @@ static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream) struct snd_pcm_runtime *runtime = substream->runtime; snd_card_saa7134_pcm_t *pcm; snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream); - struct saa7134_dev *dev = saa7134->dev; + struct saa7134_dev *dev; int amux, err; + if (!saa7134) { + printk(KERN_ERR "BUG: saa7134 can't find device struct." + " Can't proceed with open\n"); + return -ENODEV; + } + dev = saa7134->dev; mutex_lock(&dev->dmasound.lock); dev->dmasound.read_count = 0; |