net: annotate data-races on txq->xmit_lock_owner

[platform/kernel/linux-rpi.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 7dd7b9f..60cf3cd 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4147,7 +4147,10 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
        if (dev->flags & IFF_UP) {
                int cpu = smp_processor_id(); /* ok because BHs are off */
 
-               if (txq->xmit_lock_owner != cpu) {
+               /* Other cpus might concurrently change txq->xmit_lock_owner
+                * to -1 or to their cpu id, but not to our id.
+                */
+               if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
                        if (dev_xmit_recursion())
                                goto recursion_alert;