[PATCH v2] macvtap: rcu_dereference outside read-lock section

From: Denis Efremov
Date: Sun Aug 12 2012 - 02:23:36 EST


rcu_dereference occurs in update section. Replacement by
rcu_dereference_protected in order to prevent lockdep
complaint.

Found by Linux Driver Verification project (linuxtesting.org)

Signed-off-by: Denis Efremov <yefremov.denis@xxxxxxxxx>
---
drivers/net/macvtap.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 0737bd4..0f0f9ce 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -94,7 +94,8 @@ static int get_slot(struct macvlan_dev *vlan, struct macvtap_queue *q)
int i;

for (i = 0; i < MAX_MACVTAP_QUEUES; i++) {
- if (rcu_dereference(vlan->taps[i]) == q)
+ if (rcu_dereference_protected(vlan->taps[i],
+ lockdep_is_held(&macvtap_lock)) == q)
return i;
}

--
1.7.7

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