Re: [PATCH] staging: vchiq_arm: mark vchiq_platform_init() static

[Greg Kroah-Hartman]

On Tue, May 16, 2023 at 10:25:55PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> This function has no callers from other files, and the declaration
> was removed a while ago, causing a W=1 warning:
> 
> drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:465:5: error: no previous prototype for 'vchiq_platform_init'
> 
> Marking it static solves this problem but introduces a new warning
> since gcc determines that 'g_fragments_base' is never initialized
> in some kernel configurations:
> 
> In file included from include/linux/string.h:254,
>                  from include/linux/bitmap.h:11,
>                  from include/linux/cpumask.h:12,
>                  from include/linux/mm_types_task.h:14,
>                  from include/linux/mm_types.h:5,
>                  from include/linux/buildid.h:5,
>                  from include/linux/module.h:14,
>                  from drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:8:
> In function 'memcpy_to_page',
>     inlined from 'free_pagelist' at drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:433:4:
> include/linux/fortify-string.h:57:33: error: argument 2 null where non-null expected [-Werror=nonnull]
> include/linux/highmem.h:427:9: note: in expansion of macro 'memcpy'
>   427 |         memcpy(to + offset, from, len);
>       |         ^~~~~~
> 
> Add a NULL pointer check for this in addition to the static annotation
> to avoid both.
> 
> Fixes: 89cc4218f640 ("staging: vchiq_arm: drop unnecessary declarations")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Nice, thanks for finally fixing this up, it's been a low-grade annoyance
for a very long time.

greg k-h