can: statistics: add missing atomic access in hot path

Commit 80b5f90 ("can: statistics: use atomic access in hot path")
fixed a KCSAN issue in can_receive() but missed to convert the 'matches'
variable used in can_rcv_filter().

Fixes: 80b5f90 ("can: statistics: use atomic access in hot path")
Signed-off-by: Oliver Hartkopp <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: hartkopp

net/can/af_can.c

@@ -469,7 +469,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
 
 	rcv->can_id = can_id;
 	rcv->mask = mask;
-	rcv->matches = 0;
+	atomic_long_set(&rcv->matches, 0);
 	rcv->func = func;
 	rcv->data = data;
 	rcv->ident = ident;
@@ -573,7 +573,7 @@ EXPORT_SYMBOL(can_rx_unregister);
 static inline void deliver(struct sk_buff *skb, struct receiver *rcv)
 {
 	rcv->func(skb, rcv->data);
-	rcv->matches++;
+	atomic_long_inc(&rcv->matches);
 }
 
 static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb)

net/can/af_can.h

@@ -52,7 +52,7 @@ struct receiver {
 	struct hlist_node list;
 	canid_t can_id;
 	canid_t mask;
-	unsigned long matches;
+	atomic_long_t matches;
 	void (*func)(struct sk_buff *skb, void *data);
 	void *data;
 	char *ident;

net/can/proc.c

@@ -196,7 +196,8 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
 
 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
-				r->func, r->data, r->matches, r->ident);
+			   r->func, r->data, atomic_long_read(&r->matches),
+			   r->ident);
 	}
 }