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tcp: ipv4: Pass lockdep expression to RCU lists

PATCH In review Amol Grover 2 participants 3 messages Feb 21, 2020

Subsystems (2)
Networking TCP
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Amol Grover

author
#0 lore raw

PATCH 1/1 tcp: ipv4: Pass lockdep expression to RCU lists

md5sig->head maybe traversed using hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of socket lock.

Hence, add corresponding lockdep expression to silence false-positive warnings, and harden RCU lists.

Signed-off-by Amol Grover <[email protected]>
---
 net/ipv4/tcp_ipv4.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
net/ipv4/tcp_ipv4.c +4 -2
index 1c7326e04f9b..6519429f32cd 100644
@@ -1000,7 +1000,8 @@ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk,
 	if (!md5sig)
 		return NULL;
 
-	hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+	hlist_for_each_entry_rcu(key, &md5sig->head, node,
+				 lockdep_sock_is_held(sk)) {
 		if (key->family != family)
 			continue;
 

@@ -1043,7 +1044,8 @@ static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk,
 	if (family == AF_INET6)
 		size = sizeof(struct in6_addr);
 #endif
-	hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+	hlist_for_each_entry_rcu(key, &md5sig->head, node,
+				 lockdep_sock_is_held(sk)) {
 		if (key->family != family)
 			continue;
 		if (!memcmp(&key->addr, addr, size) &&
Signature · 6 lines
2.24.1

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#1 lore raw

netdev was not CC:'d on this patch, please resend with that fixed.

Thank you.