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From:   Chuang Wang <nashuiliang@gmail.com>
Cc:     Chuang Wang <nashuiliang@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Michael Braun <michael-dev@fami-braun.de>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net v2] net: macvlan: Use built-in RCU list checking
Date:   Fri, 11 Nov 2022 09:41:30 +0800
Message-Id: <20221111014131.693854-1-nashuiliang@gmail.com>
MIME-Version: 1.0
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Precedence: bulk

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to hlist_for_each_entry_rcu() to silence false
lockdep warning when CONFIG_PROVE_RCU_LIST is enabled.

Execute as follow:

 ip link add link eth0 type macvlan mode source macaddr add <MAC-ADDR>

The rtnl_lock is held when macvlan_hash_lookup_source() or
macvlan_fill_info_macaddr() are called in the non-RCU read side section.
So, pass lockdep_rtnl_is_held() to silence false lockdep warning.

Fixes: 79cf79abce71 ("macvlan: add source mode")
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
---
v1 -> v2:
- fix the patch Subject, add a Fixed tag

v0 -> v1:
- fix typo

 drivers/net/macvlan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 578897aaada0..b8cc55b2d721 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -141,7 +141,7 @@ static struct macvlan_source_entry *macvlan_hash_lookup_source(
 	u32 idx = macvlan_eth_hash(addr);
 	struct hlist_head *h = &vlan->port->vlan_source_hash[idx];
 
-	hlist_for_each_entry_rcu(entry, h, hlist) {
+	hlist_for_each_entry_rcu(entry, h, hlist, lockdep_rtnl_is_held()) {
 		if (ether_addr_equal_64bits(entry->addr, addr) &&
 		    entry->vlan == vlan)
 			return entry;
@@ -1647,7 +1647,7 @@ static int macvlan_fill_info_macaddr(struct sk_buff *skb,
 	struct hlist_head *h = &vlan->port->vlan_source_hash[i];
 	struct macvlan_source_entry *entry;
 
-	hlist_for_each_entry_rcu(entry, h, hlist) {
+	hlist_for_each_entry_rcu(entry, h, hlist, lockdep_rtnl_is_held()) {
 		if (entry->vlan != vlan)
 			continue;
 		if (nla_put(skb, IFLA_MACVLAN_MACADDR, ETH_ALEN, entry->addr))
-- 
2.37.2