[Mesa-dev] [PATCH 2/2] intel/isl: Add bounds-checking assertions for the format_info table

[Lionel Landwerlin]

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

On 06/06/18 18:17, Jason Ekstrand wrote:
> We follow the same convention as isl_format_get_layout in having two
> assertions to ensure that only valid formats are passed in.  We also
> check against the array size of the table because some valid formats
> such as CCS formats will may be past the end of the table.  This fixes
> some potential out-of-bounds array access even in valid cases.
>
> Cc: mesa-stable at lists.freedesktop.org
> ---
>   src/intel/isl/isl_format.c | 24 ++++++++++++++++--------
>   1 file changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/src/intel/isl/isl_format.c b/src/intel/isl/isl_format.c
> index 52997cf2ebb..968f981cdee 100644
> --- a/src/intel/isl/isl_format.c
> +++ b/src/intel/isl/isl_format.c
> @@ -374,11 +374,19 @@ format_gen(const struct gen_device_info *devinfo)
>      return devinfo->gen * 10 + (devinfo->is_g4x || devinfo->is_haswell) * 5;
>   }
>   
> +static bool
> +format_info_exists(enum isl_format format)
> +{
> +   assert(format != ISL_FORMAT_UNSUPPORTED);
> +   assert(format < ISL_NUM_FORMATS);
> +   return format < ARRAY_SIZE(format_info) && format_info[format].exists;
> +}
> +
>   bool
>   isl_format_supports_rendering(const struct gen_device_info *devinfo,
>                                 enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      return format_gen(devinfo) >= format_info[format].render_target;
> @@ -388,7 +396,7 @@ bool
>   isl_format_supports_alpha_blending(const struct gen_device_info *devinfo,
>                                      enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      return format_gen(devinfo) >= format_info[format].alpha_blend;
> @@ -398,7 +406,7 @@ bool
>   isl_format_supports_sampling(const struct gen_device_info *devinfo,
>                                enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      if (devinfo->is_baytrail) {
> @@ -431,7 +439,7 @@ bool
>   isl_format_supports_filtering(const struct gen_device_info *devinfo,
>                                 enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      if (devinfo->is_baytrail) {
> @@ -464,7 +472,7 @@ bool
>   isl_format_supports_vertex_fetch(const struct gen_device_info *devinfo,
>                                    enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      /* For vertex fetch, Bay Trail supports the same set of formats as Haswell
> @@ -483,7 +491,7 @@ bool
>   isl_format_supports_typed_writes(const struct gen_device_info *devinfo,
>                                    enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      return format_gen(devinfo) >= format_info[format].typed_write;
> @@ -504,7 +512,7 @@ bool
>   isl_format_supports_typed_reads(const struct gen_device_info *devinfo,
>                                   enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      return format_gen(devinfo) >= format_info[format].typed_read;
> @@ -542,7 +550,7 @@ bool
>   isl_format_supports_ccs_e(const struct gen_device_info *devinfo,
>                             enum isl_format format)
>   {
> -   if (!format_info[format].exists)
> +   if (!format_info_exists(format))
>         return false;
>   
>      /* For simplicity, only report that a format supports CCS_E if blorp can