[Mesa-dev] [PATCH] Gallium: fix buffer overflow

[Keith Whitwell]

This looks good to me -- Jose?

Keith

On Thu, 2011-06-30 at 03:33 +0100, Micael Dias wrote:
> ---
>  src/gallium/auxiliary/draw/draw_llvm.c |   12 ++++++++++++
>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
> index 56c26f5..19134f3 100644
> --- a/src/gallium/auxiliary/draw/draw_llvm.c
> +++ b/src/gallium/auxiliary/draw/draw_llvm.c
> @@ -1163,6 +1163,7 @@ draw_llvm_generate(struct draw_llvm *llvm, struct draw_llvm_variant *variant)
>     struct lp_build_loop_state lp_loop;
>     const int max_vertices = 4;
>     LLVMValueRef outputs[PIPE_MAX_SHADER_OUTPUTS][NUM_CHANNELS];
> +   LLVMValueRef fetch_max;
>     void *code;
>     struct lp_build_sampler_soa *sampler = 0;
>     LLVMValueRef ret, ret_ptr;
> @@ -1234,6 +1235,10 @@ draw_llvm_generate(struct draw_llvm *llvm, struct draw_llvm_variant *variant)
>        draw_llvm_variant_key_samplers(&variant->key),
>        context_ptr);
>  
> +   fetch_max = LLVMBuildSub(builder, count,
> +                            lp_build_const_int32(gallivm, 1),
> +                            "fetch_max");
> +
>  #if DEBUG_STORE
>     lp_build_printf(builder, "start = %d, end = %d, step = %d\n",
>                     start, end, step);
> @@ -1257,6 +1262,13 @@ draw_llvm_generate(struct draw_llvm *llvm, struct draw_llvm_variant *variant)
>              builder,
>              lp_loop.counter,
>              lp_build_const_int32(gallivm, i), "");
> +         LLVMValueRef fetch_ptr;
> +
> +         /* make sure we're not out of bounds which can happen
> +          * if fetch_count % 4 != 0, because on the last iteration
> +          * a few of the 4 vertex fetches will be out of bounds */
> +         true_index = lp_build_min(&bld, true_index, fetch_max);
> +         
>           for (j = 0; j < draw->pt.nr_vertex_elements; ++j) {
>              struct pipe_vertex_element *velem = &draw->pt.vertex_element[j];
>              LLVMValueRef vb_index = lp_build_const_int32(gallivm, velem->vertex_buffer_index);