From: Ian Romanick Date: Sat, 6 Jan 2018 02:43:32 +0000 (-0800) Subject: glsl/linker: Safely generate mask of possible locations X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=336afe7d7a8e066e1286bb93791d5c3d96ccc317;p=mesa.git glsl/linker: Safely generate mask of possible locations If MaxAttribs were ever raised to 32, undefined behavior would occur. We had already gone to the effort (albeit incorrectly) handle this in one case, so fix them all. CID: 1369628 Signed-off-by: Ian Romanick Reviewed-by: Alejandro Piñeiro --- diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp index d1f10eeecd8..86ef5831b75 100644 --- a/src/compiler/glsl/linker.cpp +++ b/src/compiler/glsl/linker.cpp @@ -2552,6 +2552,8 @@ find_available_slots(unsigned used_mask, unsigned needed_count) } +#define SAFE_MASK_FROM_INDEX(i) (((i) >= 32) ? ~0 : ((1 << (i)) - 1)) + /** * Assign locations for either VS inputs or FS outputs * @@ -2582,8 +2584,7 @@ assign_attribute_or_color_locations(void *mem_ctx, /* Mark invalid locations as being used. */ - unsigned used_locations = (max_index >= 32) - ? 0 : ~((1 << max_index) - 1); + unsigned used_locations = ~SAFE_MASK_FROM_INDEX(max_index); unsigned double_storage_locations = 0; assert((target_index == MESA_SHADER_VERTEX) @@ -2936,7 +2937,7 @@ assign_attribute_or_color_locations(void *mem_ctx, if (target_index == MESA_SHADER_VERTEX) { unsigned total_attribs_size = - _mesa_bitcount(used_locations & ((1 << max_index) - 1)) + + _mesa_bitcount(used_locations & SAFE_MASK_FROM_INDEX(max_index)) + _mesa_bitcount(double_storage_locations); if (total_attribs_size > max_index) { linker_error(prog, @@ -3000,7 +3001,7 @@ assign_attribute_or_color_locations(void *mem_ctx, */ if (target_index == MESA_SHADER_VERTEX) { unsigned total_attribs_size = - _mesa_bitcount(used_locations & ((1 << max_index) - 1)) + + _mesa_bitcount(used_locations & SAFE_MASK_FROM_INDEX(max_index)) + _mesa_bitcount(double_storage_locations); if (total_attribs_size > max_index) { linker_error(prog,