can: dump stack on protocol bugs

The rework of the kernel hlist implementation "hlist: drop the node parameter
from iterators" (b67bfe0d42cac56c512dd5da4b1b347a23f4b70a) created some
fallout in the form of non matching comments and obsolete code.

Additionally to the cleanup this patch adds a WARN() statement to catch the
caller of the wrong filter removal request.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 7 deletions

diff --git a/net/can/af_can.c b/net/can/af_can.c
index 8bacf281b3ee..c4e50852c9f4 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -546,16 +546,13 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
         }
 
         /*
-         * Check for bugs in CAN protocol implementations:
-         * If no matching list item was found, the list cursor variable next
-         * will be NULL, while r will point to the last item of the list.
+         * Check for bugs in CAN protocol implementations using af_can.c:
+         * 'r' will be NULL if no matching list item was found for removal.
          */
 
         if (!r) {
-                pr_err("BUG: receive list entry not found for "
-                       "dev %s, id %03X, mask %03X\n",
-                       DNAME(dev), can_id, mask);
-                r = NULL;
+                WARN(1, "BUG: receive list entry not found for dev %s, "
+                     "id %03X, mask %03X\n", DNAME(dev), can_id, mask);
                 goto out;
         }