2020-02-19 10:01:54

by Amol Grover

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

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 <[email protected]>
---
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

2020-02-19 18:56:19

by David Miller

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

From: Amol Grover <[email protected]>
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 <[email protected]>
> ---
> Resend:
> - Remove failed delivery recipients

Applied.