Re: [PATCH net-next] net/mlx5: Fix use of uninitialized variable in bridge.c

On Tue, Sep 14, 2021 at 03:12:47PM +0300, Leon Romanovsky wrote:

From: Leon Romanovsky <leonro@nvidia.com>

Rewrite the code to fix the following compilation warnings that were
discovered once Linus enabled -Werror flag.

drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:157:11: error:
variable 'err' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
        else if (mlx5_esw_bridge_dev_same_hw(rep, esw))
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:164:9: note:
uninitialized use occurs here
        return err;
               ^~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:157:7: note:
remove the 'if' if its condition is always true
        else if (mlx5_esw_bridge_dev_same_hw(rep, esw))
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:140:9: note:
initialize the variable 'err' to silence this warning
        int err;
               ^
                = 0
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:262:7: error:
variable 'err' is used uninitialized whenever switch case is taken
[-Werror,-Wsometimes-uninitialized]
        case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS:
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:276:9: note:
uninitialized use occurs here
        return err;
               ^~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:257:7: error:
variable 'err' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
                if (attr->u.brport_flags.mask & ~(BR_LEARNING |
BR_FLOOD | BR_MCAST_FLOOD)) {

^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:276:9: note:
uninitialized use occurs here
        return err;
               ^~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:257:3: note:
remove the 'if' if its condition is always true
                if (attr->u.brport_flags.mask & ~(BR_LEARNING |
BR_FLOOD | BR_MCAST_FLOOD)) {

^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c:247:9: note:
initialize the variable 'err' to silence this warning
        int err;
               ^
                = 0
3 errors generated.

Fixes: ff9b7521468b ("net/mlx5: Bridge, support LAG")
Reported-by: Naresh Kamboju <redacted>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 .../mellanox/mlx5/core/en/rep/bridge.c        | 36 +++++++++++--------
 1 file changed, 22 insertions(+), 14 deletions(-)

Vlad pointed to me that similar patch was already accepted.
https://patchwork.kernel.org/project/netdevbpf/patch/20210907212420.28529-2-saeed@kernel.org/

Can we please expedite the fix to Linus so our other branches (RDMA e.t.c)
that are based on pure -rcX from Linus will be compilation error free? 

Thanks