From: Eric Dumazet <edumazet@google.com>
Date: Tue, 7 Jan 2025 14:47:01 +0000 (+0000)
Subject: net: hsr: remove synchronize_rcu() from hsr_add_port()
X-Git-Tag: v6.12.63~76
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57364f7d6d921f6a991d936c5fd6638eb71f3225;p=thirdparty%2Fkernel%2Fstable.git

net: hsr: remove synchronize_rcu() from hsr_add_port()

[ Upstream commit a3b3d2dc389568a77d0e25da17203e3616218e93 ]

A synchronize_rcu() was added by mistake in commit
c5a759117210 ("net/hsr: Use list_head (and rcu) instead
of array for slave devices.")

RCU does not mandate to observe a grace period after
list_add_tail_rcu().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250107144701.503884-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: 30296ac76426 ("net: dsa: xrs700x: reject unsupported HSR configurations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
index 01762525c9456..9ac7cf0835118 100644
--- a/net/hsr/hsr_slave.c
+++ b/net/hsr/hsr_slave.c
@@ -210,7 +210,6 @@ int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 	}
 
 	list_add_tail_rcu(&port->port_list, &hsr->ports);
-	synchronize_rcu();
 
 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 	netdev_update_features(master->dev);