[SyzyAsan] Fix overflow error in ShadowWalker for 4GB 32-bit processes.

[SyzyAsan] Fix overflow error in ShadowWalker for 4GB 32-bit processes.

BUG=https://github.com/google/syzygy/issues/51

Committed: https://github.com/google/syzygy/commit/c86c6caeaef9014e707d12215c3b55fecb874043

[chrisha, 2016-09-29 14:12:10]

PTAL?

https://codereview.chromium.org/2379023002/diff/20001/syzygy/agent/asan/shado...
File syzygy/agent/asan/shadow.cc (left):

https://codereview.chromium.org/2379023002/diff/20001/syzygy/agent/asan/shado...
syzygy/agent/asan/shadow.cc:1158: sizeof(memory_info));
Doing this at every step is quite wasteful. I've rewritten the loop to first
look for valid ranges, and then iterate over each valid range in isolation.
Minimizes the number of VirtualQuery calls that need to be made.

[chrisha, 2016-09-29 14:12:17]

The CQ bit was checked by chrisha@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-29 14:12:27]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-29 14:45:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-29 14:45:14]

Dry run: This issue passed the CQ dry run.

[Sébastien Marchand, 2016-09-29 14:53:09]

sebmarchand@chromium.org changed reviewers:
+ sebmarchand@chromium.org

[Sébastien Marchand, 2016-09-29 14:53:09]

lgtm

[chrisha, 2016-09-29 15:06:55]

The CQ bit was checked by chrisha@chromium.org

[commit-bot: I haz the power, 2016-09-29 15:07:03]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-29 15:07:21]

Description was changed from

==========
[SyzyAsan] Fix overflow error in ShadowWalker for 4GB 32-bit processes.

BUG=https://github.com/google/syzygy/issues/51
==========

to

==========
[SyzyAsan] Fix overflow error in ShadowWalker for 4GB 32-bit processes.

BUG=https://github.com/google/syzygy/issues/51

Committed:
https://github.com/google/syzygy/commit/c86c6caeaef9014e707d12215c3b55fecb874043
==========

[commit-bot: I haz the power, 2016-09-29 15:07:22]

Committed patchset #2 (id:20001) as
https://github.com/google/syzygy/commit/c86c6caeaef9014e707d12215c3b55fecb874043