[PATCH v2] drm/amdgpu: Fix format character cut-off issues in amdgpu_vcn_early_init()

[Lazar, Lijo]

On 3/21/2024 10:29 AM, Srinivasan Shanmugam wrote:
> Reducing the size of ucode_prefix to 25 in the amdgpu_vcn_early_init
> function. This would ensure that the total number of characters being
> written into fw_name does not exceed its size of 40.
> 
> Fixes the below with gcc W=1:
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c: In function ‘amdgpu_vcn_early_init’:
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:102:66: warning: ‘snprintf’ output may be truncated before the last format character [-Wformat-truncation=]
>   102 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s.bin", ucode_prefix);
>       |                                                                  ^
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:102:17: note: ‘snprintf’ output between 12 and 41 bytes into a destination of size 40
>   102 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s.bin", ucode_prefix);
>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:102:66: warning: ‘snprintf’ output may be truncated before the last format character [-Wformat-truncation=]
>   102 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s.bin", ucode_prefix);
>       |                                                                  ^
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:102:17: note: ‘snprintf’ output between 12 and 41 bytes into a destination of size 40
>   102 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s.bin", ucode_prefix);
>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:105:73: warning: ‘.bin’ directive output may be truncated writing 4 bytes into a region of size between 2 and 31 [-Wformat-truncation=]
>   105 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_%d.bin", ucode_prefix, i);
>       |                                                                         ^~~~
> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c:105:25: note: ‘snprintf’ output between 14 and 43 bytes into a destination of size 40
>   105 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_%d.bin", ucode_prefix, i);
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Christian König <christian.koenig at amd.com>
> Suggested-by: Lijo Lazar <lijo.lazar at amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>

Reviewed-by: Lijo Lazar <lijo.lazar at amd.com>

Thanks,
Lijo

> ---
> v2:
>    - Reduced ucode_prefix instead of changing fw_name (Lijo)
>    - updated commit message
> 
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> index 9c514a606a2f..bb85772b1374 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> @@ -93,7 +93,7 @@ static void amdgpu_vcn_idle_work_handler(struct work_struct *work);
>  
>  int amdgpu_vcn_early_init(struct amdgpu_device *adev)
>  {
> -	char ucode_prefix[30];
> +	char ucode_prefix[25];
>  	char fw_name[40];
>  	int r, i;
>