[PATCH RESEND] net: hsr: Pass lockdep expression to RCU lists

[PATCH RESEND] net: hsr: Pass lockdep expression to RCU lists

[Amol Grover]

node_db is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of hsr->list_lock.

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

Signed-off-by: Amol Grover <frextrite@gmail.com>
---
Resend:
- Remove failed delivery recipients

 net/hsr/hsr_framereg.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
index 27dc65d7de67..cc8fcfd3918d 100644
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -156,7 +156,8 @@ static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
 		new_node->seq_out[i] = seq_out;
 
 	spin_lock_bh(&hsr->list_lock);
-	list_for_each_entry_rcu(node, node_db, mac_list) {
+	list_for_each_entry_rcu(node, node_db, mac_list,
+				lockdep_is_held(&hsr->list_lock)) {
 		if (ether_addr_equal(node->macaddress_A, addr))
 			goto out;
 		if (ether_addr_equal(node->macaddress_B, addr))
-- 
2.24.1

Re: [PATCH RESEND] net: hsr: Pass lockdep expression to RCU lists

[David Miller]

From: Amol Grover <frextrite@gmail.com>
Date: Wed, 19 Feb 2020 15:30:11 +0530

> node_db is traversed using list_for_each_entry_rcu
> outside an RCU read-side critical section but under the protection
> of hsr->list_lock.
> 
> Hence, add corresponding lockdep expression to silence false-positive
> warnings, and harden RCU lists.
> 
> Signed-off-by: Amol Grover <frextrite@gmail.com>
> ---
> Resend:
> - Remove failed delivery recipients

Applied.