tcmalloc: add a guard page in front of metadata allocations

Based on original CL:
- https://codereview.chromium.org/8570023

  Add a guard page in front of metadata allocations.

  BUG=104752
  Committed:
  http://src.chromium.org/viewvc/chrome?view=rev&revision=112260

Code has been modified to create the guard page inside MetaDataAlloc,
once per 8MB chunk.

BUG=724399,b:70905156

Change-Id: I527fbfe5e258cc052e205d01bfe2dd30e21b9f13
Reviewed-on: https://chromium-review.googlesource.com/c/1130794
Reviewed-by: Will Harris <wfh@chromium.org>
Commit-Queue: Gabriel Marin <gmx@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#595983}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 22d691ec9f38a77c7ecbee9363c7f44663824baf
4 files changed
tree: d03abacb336ecff53a56d5c765189f689d755edc
  1. src/