5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Ribalda ribalda@chromium.org
[ Upstream commit 24147897507cd3a7d63745d1518a638bf4132238 ]
Lets fix a race between mutex_is_lock() and mutex_lock().
<-mutex is not locked if (!mutex_is_locked(&ictx->lock)) { unlock = true; <- mutex is locked externaly mutex_lock(&ictx->lock); }
Let's use mutex_trylock() that does mutex_is_lock() and mutex_lock() atomically.
Fix the following cocci warning: drivers/media/rc/imon.c:1167:1-7: preceding lock on line 1153
Fixes: 23ef710e1a6c ("[media] imon: add conditional locking in change_protocol") Signed-off-by: Ricardo Ribalda ribalda@chromium.org Signed-off-by: Sean Young sean@mess.org Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/rc/imon.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index d8401ef9b0a79..38f6dd12d8706 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -1117,10 +1117,7 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 *rc_proto)
memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet));
- if (!mutex_is_locked(&ictx->lock)) { - unlock = true; - mutex_lock(&ictx->lock); - } + unlock = mutex_trylock(&ictx->lock);
retval = send_packet(ictx); if (retval)