From 336afe7d7a8e066e1286bb93791d5c3d96ccc317 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 5 Jan 2018 18:43:32 -0800 Subject: [PATCH] glsl/linker: Safely generate mask of possible locations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- src/compiler/glsl/linker.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) 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,