tree 164de7f767968a9b52bde073f0286a6a8445f016
parent b6e95c39dd91f654f0a345f17b3196f56adf4891
author Julius Werner <jwerner@chromium.org> 1379121706 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> 1379388129 +0000

libpayload: dma_malloc: Prevent warm reboot problems and add debugging

Since the DMA memory is allocated by Coreboot (outside of the payload's
linker script), it won't get zeroed upon loading like the heap.
Therefore, a warm reboot that doesn't reset memory may leave stale
malloc cookies lying around and misinterpret them as memory that is
still in use on the next boot. After several boots this may fill up the
whole DMA memory and lead to OOM conditions.

Therefore, this patch explicitly wipes the first cookie in
init_dma_memory() to prevent that from happening. It also expands the
existing memory allocator debugging code to cover the DMA parts, which
was very helpful in identifying this particular problem.

BUG=chrome-os-partner:21969
TEST=None

Change-Id: I6e2083c286ff8ec865b22dd922c39c456944b451
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/169455
Reviewed-by: Stefan Reinauer <reinauer@google.com>