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author | Marc Kleine-Budde <mkl@pengutronix.de> | 2023-09-28 21:58:23 +0200 |
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committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2023-10-05 21:32:12 +0200 |
commit | fe5c9940dfd8ba0c73672dddb30acd1b7a11d4c7 (patch) | |
tree | fe21ccae0d37b3d013d0df82a26d75f4508a0f97 /drivers/net/can | |
parent | 3b9333493b5fa69f2dce8eb96bbef32df1b65c4a (diff) | |
download | lwn-fe5c9940dfd8ba0c73672dddb30acd1b7a11d4c7.tar.gz lwn-fe5c9940dfd8ba0c73672dddb30acd1b7a11d4c7.zip |
can: dev: can_restart(): don't crash kernel if carrier is OK
During testing, I triggered a can_restart() with the netif carrier
being OK [1]. The BUG_ON, which checks if the carrier is OK, results
in a fatal kernel crash. This is neither helpful for debugging nor for
a production system.
[1] The root cause is a race condition in can_restart() which will be
fixed in the next patch.
Do not crash the kernel, issue an error message instead, and continue
restarting the CAN device anyway.
Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-1-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r-- | drivers/net/can/dev/dev.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index 7f9334a8af50..a5bbdfa9a269 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -132,7 +132,8 @@ static void can_restart(struct net_device *dev) struct can_frame *cf; int err; - BUG_ON(netif_carrier_ok(dev)); + if (netif_carrier_ok(dev)) + netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n"); /* No synchronization needed because the device is bus-off and * no messages can come in or go out. |