[Mesa-dev] [PATCH] intel: Fix size of temporary etc1 buffer

[Chad Versace]

Adding Tapani to the CC list. Removing Oliver.

On 09/20/2012 09:55 PM, Chad Versace wrote:
> Fixes valgrind errors in piglit test
> oes_compressed_etc1_rgb8_texture-miptree: an invalid write in
> _mesa_store_compressed_store_texsubimage() at line 4406 and invalid reads
> in texcompress_etc_tmp.h:etc1_parse_block().
> 
> The calculation of the size of the temporary etc1 buffer allocated by
> intel_miptree_map_etc1() was incorrect. Sometimes the allocated buffer was
> too small, sometimes too large.  This patch corrects the size to that
> expected by _mesa_store_compressed_store_texsubimage().
> 
> Note: This is candidate for the 9.0 branch.
> CC: Oliver McFadden <oliver.mcfadden at linux.intel.com>
> Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
> ---
>  src/mesa/drivers/dri/intel/intel_mipmap_tree.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> index 556a82f..c2266a4 100644
> --- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> +++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> @@ -1273,6 +1273,14 @@ intel_miptree_map_etc1(struct intel_context *intel,
>                         unsigned int level,
>                         unsigned int slice)
>  {
> +   const int block_width = 4; /*in pixels*/
> +   const int block_height = 4; /*in pixels*/
> +   const int block_size = 8; /*in bytes*/
> +
> +   /* Size of a row of blocks, in bytes. */
> +   const int row_size = block_size * ALIGN(map->w, block_width) / block_width;
> +   const int num_rows = ALIGN(map->h, block_height) / block_height;
> +
>     /* For justification of these invariants,
>      * see intel_mipmap_tree:wraps_etc1.
>      */
> @@ -1292,9 +1300,8 @@ intel_miptree_map_etc1(struct intel_context *intel,
>     assert(map->x == 0);
>     assert(map->y == 0);
>  
> -   /* Each ETC1 block contains 4x4 pixels in 8 bytes. */
> -   map->stride = 2 * map->w;
> -   map->buffer = map->ptr = malloc(map->stride * map->h);
> +   map->stride = row_size;
> +   map->buffer = map->ptr = malloc(row_size * num_rows);
>  }
>  
>  static void
>