[PATCH net-next v2 3/7] net: bridge: mcast: fix memcpy with u64_stats

David Yang posted 7 patches 2 weeks ago
[PATCH net-next v2 3/7] net: bridge: mcast: fix memcpy with u64_stats
Posted by David Yang 2 weeks ago
On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. memcpy() should not be considered tear-free.
Use u64_stats_reads() instead.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 net/bridge/br_multicast.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index d55a4ab87837..0f8e15b4fa60 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -5201,7 +5201,7 @@ void br_multicast_get_stats(const struct net_bridge *br,
 
 		do {
 			start = u64_stats_fetch_begin(&cpu_stats->syncp);
-			memcpy(&temp, &cpu_stats->mstats, sizeof(temp));
+			u64_stats_reads(&temp, &cpu_stats->mstats, sizeof(temp));
 		} while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
 
 		mcast_stats_add_dir(tdst.igmp_v1queries, temp.igmp_v1queries);
-- 
2.51.0