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* [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists
@ 2020-02-21 15:21 Amol Grover
  2020-02-21 16:19 ` David Miller
  0 siblings, 1 reply; 5+ messages in thread
From: Amol Grover @ 2020-02-21 15:21 UTC (permalink / raw)
  To: Eric Dumazet, David S . Miller, Alexey Kuznetsov,
	Hideaki YOSHIFUJI, Jakub Kicinski
  Cc: linux-kernel, linux-kernel-mentees, Joel Fernandes,
	Madhuparna Bhowmik, Paul E . McKenney, Amol Grover

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 <frextrite@gmail.com>
---
 net/ipv4/tcp_ipv4.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1c7326e04f9b..6519429f32cd 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -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) &&
-- 
2.24.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists
  2020-02-21 15:21 [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists Amol Grover
@ 2020-02-21 16:19 ` David Miller
  2020-02-21 18:05   ` Amol Grover
  0 siblings, 1 reply; 5+ messages in thread
From: David Miller @ 2020-02-21 16:19 UTC (permalink / raw)
  To: frextrite
  Cc: edumazet, kuznet, yoshfuji, kuba, linux-kernel,
	linux-kernel-mentees, joel, madhuparnabhowmik10, paulmck


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

Thank you.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists
  2020-02-21 16:19 ` David Miller
@ 2020-02-21 18:05   ` Amol Grover
  0 siblings, 0 replies; 5+ messages in thread
From: Amol Grover @ 2020-02-21 18:05 UTC (permalink / raw)
  To: David Miller
  Cc: edumazet, kuznet, yoshfuji, kuba, linux-kernel,
	linux-kernel-mentees, joel, madhuparnabhowmik10, paulmck

On Fri, Feb 21, 2020 at 08:19:58AM -0800, David Miller wrote:
> 
> netdev was not CC:'d on this patch, please resend with that fixed.
> 

Sorry for that. I've resend the patch.

Thanks
Amol

> Thank you.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists
  2020-02-21 17:57 Amol Grover
@ 2020-02-24 21:07 ` David Miller
  0 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2020-02-24 21:07 UTC (permalink / raw)
  To: frextrite
  Cc: edumazet, kuznet, yoshfuji, kuba, linux-kernel,
	linux-kernel-mentees, joel, madhuparnabhowmik10, paulmck, netdev

From: Amol Grover <frextrite@gmail.com>
Date: Fri, 21 Feb 2020 23:27:14 +0530

> 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 <frextrite@gmail.com>

Applied.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists
@ 2020-02-21 17:57 Amol Grover
  2020-02-24 21:07 ` David Miller
  0 siblings, 1 reply; 5+ messages in thread
From: Amol Grover @ 2020-02-21 17:57 UTC (permalink / raw)
  To: Eric Dumazet, David S . Miller, Alexey Kuznetsov,
	Hideaki YOSHIFUJI, Jakub Kicinski
  Cc: linux-kernel, linux-kernel-mentees, Joel Fernandes,
	Madhuparna Bhowmik, Paul E . McKenney, netdev, Amol Grover

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 <frextrite@gmail.com>
---
 net/ipv4/tcp_ipv4.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1c7326e04f9b..6519429f32cd 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -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) &&
-- 
2.24.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-02-24 21:07 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-02-21 15:21 [PATCH] tcp: ipv4: Pass lockdep expression to RCU lists Amol Grover
2020-02-21 16:19 ` David Miller
2020-02-21 18:05   ` Amol Grover
2020-02-21 17:57 Amol Grover
2020-02-24 21:07 ` David Miller

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