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

[Umang Jain]

Hi

On 5/17/23 1:55 AM, 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>

Reviewed-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>

> ---
>   drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> index 90a3958d1f29..aa2313f3bcab 100644
> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> @@ -415,7 +415,7 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
>   	pagelistinfo->scatterlist_mapped = 0;
>   
>   	/* Deal with any partial cache lines (fragments) */
> -	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
> +	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS && g_fragments_base) {
>   		char *fragments = g_fragments_base +
>   			(pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
>   			g_fragments_size;
> @@ -462,7 +462,7 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
>   	cleanup_pagelistinfo(instance, pagelistinfo);
>   }
>   
> -int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
> +static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct vchiq_drvdata *drvdata = platform_get_drvdata(pdev);