[igt-dev] [PATCH i-g-t v3] lib/igt_fb: fix the plane_size array for yuv formats

[Petri Latvala]

On Wed, Dec 08, 2021 at 04:40:40PM -0800, Abhinav Kumar wrote:
> clear_yuv_buffer() checks the size of the plane_size[] to
> make sure its greater than the number of planes to avoid
> overflows.
> 
> The plane_size[] is fixed to two currently.
> 
> However some of the formats like YV12 indeed have more than
> 2 planes in the format_desc[] hence this incorrectly failing
> this check.
> 
> Increase the size of the plane_size[] to match the correct
> max number of planes.
> 
> changes in v3:
> 	- use drm_format->num_planes to create the plane_size
> 	- add assert checks for num of planes before memset
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> ---
>  lib/igt_fb.c | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/igt_fb.c b/lib/igt_fb.c
> index 92a0170..1530b96 100644
> --- a/lib/igt_fb.c
> +++ b/lib/igt_fb.c
> @@ -1007,7 +1007,8 @@ static void memset64(uint64_t *s, uint64_t c, size_t n)
>  static void clear_yuv_buffer(struct igt_fb *fb)
>  {
>  	bool full_range = fb->color_range == IGT_COLOR_YCBCR_FULL_RANGE;
> -	size_t plane_size[2];
> +	int num_planes = lookup_drm_format(fb->drm_format)->num_planes;
> +	size_t plane_size[num_planes];
>  	void *ptr;
>  
>  	igt_assert(igt_format_is_yuv(fb->drm_format));
> @@ -1015,7 +1016,8 @@ static void clear_yuv_buffer(struct igt_fb *fb)
>  	for (int i = 0; i < lookup_drm_format(fb->drm_format)->num_planes; i++) {

Since we have num_planes grabbed to a variable, might as well replace
this lookup call with it too.


>  		unsigned int tile_width, tile_height;
>  
> -		igt_assert_lt(i, ARRAY_SIZE(plane_size));
> +		igt_assert_lt(i, num_planes);
> +
>  		igt_get_fb_tile_size(fb->fd, fb->modifier, fb->plane_bpp[i],
>  				     &tile_width, &tile_height);
>  		plane_size[i] = fb->strides[i] *
> @@ -1082,6 +1084,21 @@ static void clear_yuv_buffer(struct igt_fb *fb)
>  			 full_range ? 0x800000008000ULL : 0x800010008000ULL,
>  			 plane_size[0] / sizeof(uint64_t));
>  		break;
> +	case DRM_FORMAT_YUV420:
> +	case DRM_FORMAT_YUV422:
> +	case DRM_FORMAT_YVU420:
> +	case DRM_FORMAT_YVU422:
> +		igt_assert(ARRAY_SIZE(plane_size) == 3);
> +		memset(ptr + fb->offsets[0],
> +		       full_range ? 0x00 : 0x10,
> +		       plane_size[0]);
> +		memset(ptr + fb->offsets[1],
> +		       0x80,
> +		       plane_size[1]);
> +		memset(ptr + fb->offsets[2],
> +		       0x80,
> +		       plane_size[2]);
> +		break;


I have no clue what the correct numbers should be here. =(


-- 
Petri Latvala