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