[Mesa-dev] [PATCH] swr: Align swr_context allocation to SIMD alignment.

Bruce Cherniak bruce.cherniak at intel.com
Wed Apr 12 23:43:25 UTC 2017


The context now contains SIMD vectors which must be aligned (specifically
samplePositions in the rastState in the derived state).  Failure to align
can result in segv crash on unaligned memory access in vector
instructions.

---
 src/gallium/drivers/swr/swr_context.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/swr/swr_context.cpp b/src/gallium/drivers/swr/swr_context.cpp
index 8c5a269..6f46d66 100644
--- a/src/gallium/drivers/swr/swr_context.cpp
+++ b/src/gallium/drivers/swr/swr_context.cpp
@@ -386,7 +386,7 @@ swr_destroy(struct pipe_context *pipe)
    if (screen->pipe == pipe)
       screen->pipe = NULL;
 
-   FREE(ctx);
+   AlignedFree(ctx);
 }
 
 
@@ -452,7 +452,10 @@ swr_UpdateStatsFE(HANDLE hPrivateContext, const SWR_STATS_FE *pStats)
 struct pipe_context *
 swr_create_context(struct pipe_screen *p_screen, void *priv, unsigned flags)
 {
-   struct swr_context *ctx = CALLOC_STRUCT(swr_context);
+   struct swr_context *ctx = (struct swr_context *)
+      AlignedMalloc(sizeof(struct swr_context), KNOB_SIMD_BYTES);
+   memset(ctx, 0, sizeof(struct swr_context));
+
    ctx->blendJIT =
       new std::unordered_map<BLEND_COMPILE_STATE, PFN_BLEND_JIT_FUNC>;
 
-- 
2.7.4



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