Re: [PATCH] [v3] kasan: avoid -Wmaybe-uninitialized warning

From: Andrey Ryabinin
Date: Tue Jul 25 2017 - 11:29:09 EST


On 07/25/2017 06:27 PM, Arnd Bergmann wrote:
> gcc-7 produces this warning:
>
> mm/kasan/report.c: In function 'kasan_report':
> mm/kasan/report.c:351:3: error: 'info.first_bad_addr' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> print_shadow_for_address(info->first_bad_addr);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> mm/kasan/report.c:360:27: note: 'info.first_bad_addr' was declared here
>
> The code seems fine as we only print info.first_bad_addr when there is a shadow,
> and we always initialize it in that case, but this is relatively hard
> for gcc to figure out after the latest rework. Adding an intialization
> to the most likely value together with the other struct members
> shuts up that warning.
>
> Fixes: b235b9808664 ("kasan: unify report headers")
> Link: https://patchwork.kernel.org/patch/9641417/
> Suggested-by: Alexander Potapenko <glider@xxxxxxxxxx>
> Suggested-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---

Acked-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>