2020-05-27 10:30:17

by Nathan Chancellor

Subject: [PATCH] net/mlx5e: Don't use err uninitialized in mlx5e_attach_decap

Clang warns:

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3712:6: warning:
variable 'err' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
if (IS_ERR(d->pkt_reformat)) {
^~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3718:6: note:
uninitialized use occurs here
if (err)
^~~
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3712:2: note: remove the
'if' if its condition is always true
if (IS_ERR(d->pkt_reformat)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3670:9: note: initialize
the variable 'err' to silence this warning
int err;
^
= 0
1 warning generated.

It is not wrong, err is only ever initialized in if statements but this
one is not in one. Initialize err to 0 to fix this.

Fixes: 14e6b038afa0 ("net/mlx5e: Add support for hw decapsulation of MPLS over UDP")
Link: https://github.com/ClangBuiltLinux/linux/issues/1037
Signed-off-by: Nathan Chancellor <[email protected]>
---
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index fdb7d2686c35..6d0d4896fe0c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -3667,7 +3667,7 @@ static int mlx5e_attach_decap(struct mlx5e_priv *priv,
struct mlx5e_decap_entry *d;
struct mlx5e_decap_key key;
uintptr_t hash_key;
- int err;
+ int err = 0;

parse_attr = attr->parse_attr;
if (sizeof(parse_attr->eth) > MLX5_CAP_ESW(priv->mdev, max_encap_header_size)) {

base-commit: d3d9065ad99d0d8d732c950cc0a37a7883cd0c60
--
2.27.0.rc0

2020-05-27 19:13:03

by Saeed Mahameed

Subject: Re: [PATCH] net/mlx5e: Don't use err uninitialized in mlx5e_attach_decap

On Wed, 2020-05-27 at 00:50 -0700, Nathan Chancellor wrote:
> Clang warns:
>
> drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3712:6: warning:
> variable 'err' is used uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
> if (IS_ERR(d->pkt_reformat)) {
> ^~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3718:6: note:
> uninitialized use occurs here
> if (err)
> ^~~
> drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3712:2: note: remove
> the
> 'if' if its condition is always true
> if (IS_ERR(d->pkt_reformat)) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:3670:9: note:
> initialize
> the variable 'err' to silence this warning
> int err;
> ^
> = 0
> 1 warning generated.
>
> It is not wrong, err is only ever initialized in if statements but
> this
> one is not in one. Initialize err to 0 to fix this.
>
> Fixes: 14e6b038afa0 ("net/mlx5e: Add support for hw decapsulation of
> MPLS over UDP")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1037
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---

Applied to net-next-mlx5, will send shortly to net-next

Thanks,
Saeed.