can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb

commit 7da11ba5c5 upstream.

Prior to echoing a successfully transmitted CAN frame (by calling
can_get_echo_skb()), CAN drivers have to put the CAN frame (by calling
can_put_echo_skb() in the transmit function). These put and get function
take an index as parameter, which is used to identify the CAN frame.

A driver calling can_get_echo_skb() with a index not pointing to a skb
is a BUG, so add an appropriate error message.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This commit is contained in:
Marc Kleine-Budde 2018-10-31 14:15:13 +01:00 • committed by Ben Hutchings
commit bf0faabcab