diff mbox

[dpdk-dev] net/mlx5: fix an uninitialised variable

Message ID 4b9e3b9e3328d43d5766a39391695e704298d04f.1491470160.git.nelio.laranjeiro@6wind.com (mailing list archive)
State Accepted, archived
Delegated to: Ferruh Yigit
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Nélio Laranjeiro April 6, 2017, 9:16 a.m. UTC 
  Since patch "mbuf: structure reorganization" the compiler complains

 .../drivers/net/mlx5/mlx5_rxtx.c: In function ‘mlx5_rx_burst’:
 .../drivers/net/mlx5/mlx5_rxtx.c:2082:17: error: ‘len’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]

len is not initialised as it will be at the first segment of a received
packet, but it remains hard for the compiler to determine it.

Fixes: 9964b965ad69 ("net/mlx5: re-add Rx scatter support")

Cc: stable@dpdk.org
Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Thomas Monjalon April 6, 2017, 11:06 a.m. UTC | #1 
2017-04-06 11:16, Nelio Laranjeiro:
> Since patch "mbuf: structure reorganization" the compiler complains
> 
>  .../drivers/net/mlx5/mlx5_rxtx.c: In function ‘mlx5_rx_burst’:
>  .../drivers/net/mlx5/mlx5_rxtx.c:2082:17: error: ‘len’ may be used
> uninitialized in this function [-Werror=maybe-uninitialized]
> 
> len is not initialised as it will be at the first segment of a received
> packet, but it remains hard for the compiler to determine it.
> 
> Fixes: 9964b965ad69 ("net/mlx5: re-add Rx scatter support")
> 
> Cc: stable@dpdk.org
> Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
> Acked-by: Olivier Matz <olivier.matz@6wind.com>

Applied, thanks

It is important to note that we see this error only after the mbuf rework
of 17.05, only with GCC, and only when debug is enabled.
diff mbox

Patch

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 06b699a..fae9d27 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -1972,7 +1972,7 @@  mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		&(*rxq->cqes)[rxq->cq_ci & cqe_cnt];
 	unsigned int i = 0;
 	unsigned int rq_ci = rxq->rq_ci << sges_n;
-	int len; /* keep its value across iterations. */
+	int len = 0; /* keep its value across iterations. */
 
 	while (pkts_n) {
 		unsigned int idx = rq_ci & wqe_cnt;