Re: [PATCH] cxgb3: Convert from atomic_t to refcount_t on l2t_entry->refcnt

refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.

Signed-off-by: Xiyu Yang <redacted>
Signed-off-by: Xin Tan <redacted>
---
 drivers/net/ethernet/chelsio/cxgb3/l2t.c | 15 ++++++++-------
 drivers/net/ethernet/chelsio/cxgb3/l2t.h | 10 +++++++---
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb3/l2t.c b/drivers/net/ethernet/chelsio/cxgb3/l2t.c
index 9749d1239f58..0f2a47bc20d8 100644
--- a/drivers/net/ethernet/chelsio/cxgb3/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/l2t.c

@@ -225,10 +225,11 @@ static struct l2t_entry *alloc_l2e(struct l2t_data *d)
 
 	/* there's definitely a free entry */
 	for (e = d->rover, end = &d->l2tab[d->nentries]; e != end; ++e)
-		if (atomic_read(&e->refcnt) == 0)
+		if (refcount_read(&e->refcnt) == 0)