Re: [PATCH 06/12] s390: ctcm: fix ctcm_new_device error return code

[Martin Schwidefsky <schwidefsky@de.ibm.com>]

On Mon,  8 Apr 2019 23:26:19 +0200
Arnd Bergmann <arnd@arndb.de> wrote:

> clang points out that the return code from this function is
> undefined for one of the error paths:
> 
> ../drivers/s390/net/ctcm_main.c:1595:7: warning: variable 'result' is used uninitialized whenever 'if' condition is true
>       [-Wsometimes-uninitialized]
>                 if (priv->channel[direction] == NULL) {
>                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/s390/net/ctcm_main.c:1638:9: note: uninitialized use occurs here
>         return result;
>                ^~~~~~
> ../drivers/s390/net/ctcm_main.c:1595:3: note: remove the 'if' if its condition is always false
>                 if (priv->channel[direction] == NULL) {
>                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/s390/net/ctcm_main.c:1539:12: note: initialize the variable 'result' to silence this warning
>         int result;
>                   ^
> 
> Make it return -ENODEV here, as in the related failure cases.
> gcc has a known bug in underreporting some of these warnings
> when it has already eliminated the assignment of the return code
> based on some earlier optimization step.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Added to our internal tree for Julian to pick up.

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.