From 4a8937b83892cb69524291cae6cdabad4a8be033 Mon Sep 17 00:00:00 2001 From: Chuhong Yuan Date: Tue, 6 Aug 2019 10:58:46 +0800 Subject: [PATCH] cxgb4: smt: Add lock for atomic_dec_and_test The atomic_dec_and_test() is not safe because it is outside of locks. Move the locks of t4_smte_free() to its caller, cxgb4_smt_release() to protect the atomic decrement. Fixes: 3bdb376e6944 ("cxgb4: introduce SMT ops to prepare for SMAC rewrite support") Signed-off-by: Chuhong Yuan Signed-off-by: David S. Miller --- drivers/net/ethernet/chelsio/cxgb4/smt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/smt.c b/drivers/net/ethernet/chelsio/cxgb4/smt.c index eaf1fb7..d6e84c8 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/smt.c +++ b/drivers/net/ethernet/chelsio/cxgb4/smt.c @@ -97,11 +97,9 @@ found_reuse: static void t4_smte_free(struct smt_entry *e) { - spin_lock_bh(&e->lock); if (atomic_read(&e->refcnt) == 0) { /* hasn't been recycled */ e->state = SMT_STATE_UNUSED; } - spin_unlock_bh(&e->lock); } /** @@ -111,8 +109,10 @@ static void t4_smte_free(struct smt_entry *e) */ void cxgb4_smt_release(struct smt_entry *e) { + spin_lock_bh(&e->lock); if (atomic_dec_and_test(&e->refcnt)) t4_smte_free(e); + spin_unlock_bh(&e->lock); } EXPORT_SYMBOL(cxgb4_smt_release); -- 2.7.4