[Mesa-dev] [PATCH 3/7] i965: Add a safety check for emitting blits.

[Eric Anholt]

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.
---
 src/mesa/drivers/dri/i965/intel_blit.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/intel_blit.c b/src/mesa/drivers/dri/i965/intel_blit.c
index 13cc777..9162b1f 100644
--- 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);
 
-- 
1.8.5.1