Module: Mesa Branch: master Commit: d7430d942f6c7950a92367aeb13b80cf76ccad78 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=d7430d942f6c7950a92367aeb13b80cf76ccad78
Author: Eric Anholt <[email protected]> Date: Mon Aug 3 17:55:14 2009 -0700 i965: Assert that the offset in the VBO is below the VBO size. This avoids sending a bad buffer address to the GPU due to programmer error, and is permitted by the ARB_vbo spec. Note that we still have the opportunity to dereference past the end of the GPU, because we aren't clipping to a correct _MaxElement, but that appears to be harder than it should be. This gets us the 90% solution. Bug #19911. --- src/mesa/drivers/dri/i965/brw_draw_upload.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c index 55ec953..760b22f 100644 --- a/src/mesa/drivers/dri/i965/brw_draw_upload.c +++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c @@ -396,6 +396,20 @@ static void brw_prepare_vertices(struct brw_context *brw) dri_bo_reference(input->bo); input->offset = (unsigned long)input->glarray->Ptr; input->stride = input->glarray->StrideB; + + /* This is a common place to reach if the user mistakenly supplies + * a pointer in place of a VBO offset. If we just let it go through, + * we may end up dereferencing a pointer beyond the bounds of the + * GTT. We would hope that the VBO's max_index would save us, but + * Mesa appears to hand us min/max values not clipped to the + * array object's _MaxElement, and _MaxElement frequently appears + * to be wrong anyway. + * + * The VBO spec allows application termination in this case, and it's + * probably a service to the poor programmer to do so rather than + * trying to just not render. + */ + assert(input->offset < input->bo->size); } else { if (input->bo != NULL) { /* Already-uploaded vertex data is present from a previous _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
