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| author | Ricardo Cerqueira <v4l@cerqueira.org> | 2008-02-13 22:41:15 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-02-18 12:18:08 -0300 |
| commit | baff6cdd3328e7b35c4e155d79105621812bceec (patch) | |
| tree | ab034bb13f4c37f9d874b46b6f8d855ead19fb06 | |
| parent | 40ae91a758df916d7a5640fb2de20537ef7849fd (diff) | |
| download | linux-3.10-baff6cdd3328e7b35c4e155d79105621812bceec.tar.gz linux-3.10-baff6cdd3328e7b35c4e155d79105621812bceec.tar.bz2 linux-3.10-baff6cdd3328e7b35c4e155d79105621812bceec.zip | |
V4L/DVB (7201): cx88-mpeg: Fix race condition in variable access
There was a possible race condition in the increment/decrement of
the active device references counter.
Thanks to Trent Piepho (xyzzy@speakeasy.org) for bringing it up.
Signed-off-by: Ricardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
| -rw-r--r-- | drivers/media/video/cx88/cx88-mpeg.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/media/video/cx88/cx88-mpeg.c b/drivers/media/video/cx88/cx88-mpeg.c index f12733d6bf7..e357f415db0 100644 --- a/drivers/media/video/cx88/cx88-mpeg.c +++ b/drivers/media/video/cx88/cx88-mpeg.c @@ -615,8 +615,8 @@ static int cx8802_request_acquire(struct cx8802_driver *drv) if (drv->advise_acquire) { - core->active_ref++; mutex_lock(&drv->core->lock); + core->active_ref++; if (core->active_type_id == CX88_BOARD_NONE) { core->active_type_id = drv->type_id; drv->advise_acquire(drv); @@ -634,14 +634,14 @@ static int cx8802_request_release(struct cx8802_driver *drv) { struct cx88_core *core = drv->core; + mutex_lock(&drv->core->lock); if (drv->advise_release && --core->active_ref == 0) { - mutex_lock(&drv->core->lock); drv->advise_release(drv); core->active_type_id = CX88_BOARD_NONE; - mutex_unlock(&drv->core->lock); mpeg_dbg(1,"%s() Post release GPIO=%x\n", __FUNCTION__, cx_read(MO_GP0_IO)); } + mutex_unlock(&drv->core->lock); return 0; } |