tree 2cf5b2bb5c7c4b7859483b44c66e104886796fbb
parent 9555830f4eb434a2dbb3ac4bcb58fa7ce361d2c4
author Sean Risser <srisser@google.com> 1559062228 -0400
committer Sean Risser <srisser@google.com> 1559156274 +0000

Fix buffer overflow on Mac

For OpenGL on Mac, Swiftshader renders directly to the IOSurface given
to us by the OS. This surface is not necessarily vertically padded so
its height is a multiple of 2. Since we render 4 pixels at a time in a
quad, the bottom 2 pixels may not be written to legal memory if the
height of the target surface is an odd number.

This change prevents Swiftshader from rendering quads on Mac if doing so
would overflow the buffer.

Bug: chromium:944796
Bug: angleproject:2764

Change-Id: I08bec895980b42f99b8a4434969edcaf7d331284
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/32030
Presubmit-Ready: Sean Risser <srisser@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Sean Risser <srisser@google.com>