From 33d331859a2c35134c18ad2ab37d2e529d76816e Mon Sep 17 00:00:00 2001 From: Andres Gomez Date: Fri, 18 Jan 2019 18:33:10 +0200 Subject: [PATCH 21/22] glsl/linker: simplify xfb_offset vs xfb_stride overflow check Current implementation uses a complicated calculation which relies in an implicit conversion to check the integral part of 2 division results. However, the calculation actually checks that the xfb_offset is smaller or a multiplier of the xfb_stride. For example, while this is expected to fail, it actually succeeds: " ... layout(xfb_buffer = 2, xfb_stride = 12) out block3 { layout(xfb_offset = 0) vec3 c; layout(xfb_offset = 12) vec3 d; // ERROR, requires stride of 24 }; ... " Fixes: 2fab85aaea5 ("glsl: add xfb_stride link time validation") Cc: Timothy Arceri Signed-off-by: Andres Gomez Reviewed-by: Timothy Arceri (cherry picked from commit 422882e78f2cf0ab69ff4a58f3c9465fcb5fef0d) --- src/compiler/glsl/link_varyings.cpp | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp index 8aa5ba098c8..56fff60e07a 100644 --- a/src/compiler/glsl/link_varyings.cpp +++ b/src/compiler/glsl/link_varyings.cpp @@ -1178,8 +1178,7 @@ tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog, return false; } - if ((this->offset / 4) / info->Buffers[buffer].Stride != - (xfb_offset - 1) / info->Buffers[buffer].Stride) { + if (xfb_offset > info->Buffers[buffer].Stride) { linker_error(prog, "xfb_offset (%d) overflows xfb_stride (%d) for " "buffer (%d)", xfb_offset * 4, info->Buffers[buffer].Stride * 4, buffer); -- 2.21.0