Re: [PATCH 1/2] bnxt_en: Use refcount_t for refcount
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2019-07-31 16:06:02
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On Wed, Jul 31, 2019 at 8:22 AM Chuhong Yuan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
refcount_t is better for reference counters since its implementation can prevent overflows. So convert atomic_t ref counters to refcount_t. Signed-off-by: Chuhong Yuan <redacted> --- drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c | 8 ++++---- drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-)diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c index fc77caf0a076..eb7ed34639e2 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c@@ -49,7 +49,7 @@ static int bnxt_register_dev(struct bnxt_en_dev *edev, int ulp_id, return -ENOMEM; } - atomic_set(&ulp->ref_count, 0); + refcount_set(&ulp->ref_count, 0);
One feature of refcount_t is that it warns on refcount_inc from 0 to detect possible use-after_free. It appears that that can trigger here?
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ulp->handle = handle; rcu_assign_pointer(ulp->ulp_ops, ulp_ops);@@ -246,12 +246,12 @@ static int bnxt_send_msg(struct bnxt_en_dev *edev, int ulp_id, static void bnxt_ulp_get(struct bnxt_ulp *ulp) { - atomic_inc(&ulp->ref_count); + refcount_inc(&ulp->ref_count); }