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Reviewed-by: Tim Rowley <<a href="mailto:timothy.o.rowley@intel.com" class="">timothy.o.rowley@intel.com</a>>
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<div class="">On Jun 15, 2017, at 11:24 AM, Bruce Cherniak <<a href="mailto:bruce.cherniak@intel.com" class="">bruce.cherniak@intel.com</a>> wrote:</div>
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<div class="">The swr driver uses vertex_buffer->stride to determine the number<br class="">
of elements in a VBO. A recent change to the state-tracker made it<br class="">
possible for VBO's with stride=0. This resulted in a divide by zero<br class="">
crash in the driver. The solution is to use the pre-calculated vertex<br class="">
element stream_pitch in this case.<br class="">
<br class="">
This patch fixes the crash in a number of piglit and VTK tests introduced<br class="">
by 17f776c27be266f2.<br class="">
<br class="">
There are several VTK tests that still crash and need proper handling of<br class="">
vertex_buffer_index. This will come in a follow-on patch.<br class="">
<br class="">
v2: Correctly update all parameters for VBO constants (stride = 0).<br class="">
Also fixes the remaining crashes/regressions that v1 did<br class="">
not address, without touching vertex_buffer_index.<br class="">
---<br class="">
src/gallium/drivers/swr/swr_state.cpp | 25 ++++++++++++++++++-------<br class="">
1 file changed, 18 insertions(+), 7 deletions(-)<br class="">
<br class="">
diff --git a/src/gallium/drivers/swr/swr_state.cpp b/src/gallium/drivers/swr/swr_state.cpp<br class="">
index 08549e51a1..316872581d 100644<br class="">
--- a/src/gallium/drivers/swr/swr_state.cpp<br class="">
+++ b/src/gallium/drivers/swr/swr_state.cpp<br class="">
@@ -1247,13 +1247,24 @@ swr_update_derived(struct pipe_context *pipe,<br class="">
<br class="">
pitch = vb->stride;<br class="">
if (!vb->is_user_buffer) {<br class="">
- /* VBO<br class="">
- * size is based on buffer->width0 rather than info.max_index<br class="">
- * to prevent having to validate VBO on each draw */<br class="">
- size = vb->buffer.resource->width0;<br class="">
- elems = size / pitch;<br class="">
- partial_inbounds = size % pitch;<br class="">
- min_vertex_index = 0;<br class="">
+ /* VBO */<br class="">
+ if (!pitch) {<br class="">
+ /* If pitch=0 (ie vb->stride), buffer contains a single<br class="">
+ * constant attribute. Use the stream_pitch which was<br class="">
+ * calculated during creation of vertex_elements_state for the<br class="">
+ * size of the attribute. */<br class="">
+ size = ctx->velems->stream_pitch[i];<br class="">
+ elems = 1;<br class="">
+ partial_inbounds = 0;<br class="">
+ min_vertex_index = 0;<br class="">
+ } else {<br class="">
+ /* size is based on buffer->width0 rather than info.max_index<br class="">
+ * to prevent having to validate VBO on each draw. */<br class="">
+ size = vb->buffer.resource->width0;<br class="">
+ elems = size / pitch;<br class="">
+ partial_inbounds = size % pitch;<br class="">
+ min_vertex_index = 0;<br class="">
+ }<br class="">
<br class="">
p_data = swr_resource_data(vb->buffer.resource) + vb->buffer_offset;<br class="">
} else {<br class="">
-- <br class="">
2.11.0<br class="">
<br class="">
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https://lists.freedesktop.org/mailman/listinfo/mesa-dev<br class="">
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