i965: Add a safety check for emitting blits.

With all of the flipping and pitch twiddling and miptree layout involved
in our blits, there are lots of ways for us to scribble outside of a
buffer.  Put in a check that we're not about to do so.

This catches a bug that glamor was running into.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

diff --git a/src/mesa/drivers/dri/i965/intel_blit.c b/src/mesa/drivers/dri/i965/intel_blit.c
index 13cc77792e479d5ef361145a9b042c3484f83ce5..9162b1fc336077d42f0c511614760e039e8efc1e 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_blit.c
+++ b/src/mesa/drivers/dri/i965/intel_blit.c
@@ -391,6 +391,10 @@ intelEmitCopyBlit(struct brw_context *brw,
 
    assert(dst_x < dst_x2);
    assert(dst_y < dst_y2);
+   assert(src_offset + (src_y + h - 1) * abs(src_pitch) +
+          (w * cpp) <= src_buffer->size);
+   assert(dst_offset + (dst_y + h - 1) * abs(dst_pitch) +
+          (w * cpp) <= dst_buffer->size);
 
    BEGIN_BATCH_BLT_TILED(8, dst_y_tiled, src_y_tiled);