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| author | Ricardo Cerqueira <v4l@cerqueira.org> | 2008-02-13 22:41:15 +0000 |
|---|---|---|
| committer | Ricardo Cerqueira <v4l@cerqueira.org> | 2008-02-13 22:41:15 +0000 |
| commit | 6494d36c801e81065cdfe9d1bf2b61b92e66111e (patch) | |
| tree | 22a820291bdfea2e687164d5adf1c13f2e1d73e6 /linux/drivers | |
| parent | 4890c6c64ffcaed9a31fc856b2935f8417f339e7 (diff) | |
| download | mediapointer-dvb-s2-6494d36c801e81065cdfe9d1bf2b61b92e66111e.tar.gz mediapointer-dvb-s2-6494d36c801e81065cdfe9d1bf2b61b92e66111e.tar.bz2 | |
cx88-mpeg: Fix race condition in variable access
From: Ricardo Cerqueira <v4l@cerqueira.org>
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>
Diffstat (limited to 'linux/drivers')
| -rw-r--r-- | linux/drivers/media/video/cx88/cx88-mpeg.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/linux/drivers/media/video/cx88/cx88-mpeg.c b/linux/drivers/media/video/cx88/cx88-mpeg.c index 399c3f1fc..1f641273c 100644 --- a/linux/drivers/media/video/cx88/cx88-mpeg.c +++ b/linux/drivers/media/video/cx88/cx88-mpeg.c @@ -673,8 +673,8 @@ 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); @@ -692,14 +692,14 @@ 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; } |