From: Chuhong Yuan <hslester96@gmail.com>
Date: Tue, 6 Aug 2019 10:58:46 +0800
Subject: cxgb4: smt: Add lock for atomic_dec_and_test
Patch-mainline: v5.4-rc1
Git-commit: 4a8937b83892cb69524291cae6cdabad4a8be033
References: bsc#1064802 bsc#1066129
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 <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/chelsio/cxgb4/smt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/chelsio/cxgb4/smt.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/smt.c
@@ -98,11 +98,9 @@ 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);
}
/**
@@ -112,8 +110,10 @@ static void t4_smte_free(struct smt_entr
*/
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);