GitLab

This is a reland of e77256b1 now that
crrev.com/00fb4b7e landed fixing the lock-up
issue we previously saw.

Original change's description:
> [cfi-icall] Use ProtectedMemory for localtime ptrs
>
> Control Flow Integrity [1] indirect call (cfi-icall) checking can not
> verify that dynamically resolved function pointers call their intended
> function. Instead we place the LibcFunctions pointers in
> ProtectedMemory, a wrapper for keeping variables in read-only memory
> except for when they are initialized.  After setting the pointers in
> protected memory we can use the UnsanitizedCfiCall wrapper to disable
> cfi-icall checking when calling them since we know they can not be
> tampered with.
>
> [1] https://www.chromium.org/developers/testing/control-flow-integrity
>
> Bug: 771365
> Change-Id: Ib74faff066e1107293b67d11f2a1a054bbff08b5
> Reviewed-on: https://chromium-review.googlesource.com/769853
> Reviewed-by: Chris Palmer <palmer@chromium.org>
> Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
> Reviewed-by: Peter Collingbourne <pcc@chromium.org>
> Commit-Queue: Peter Collingbourne <pcc@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#517152}

Bug: 771365
Change-Id: Iaba5de8e37332878cd0b85c9dbdafc08e2d9a6ba
Reviewed-on: https://chromium-review.googlesource.com/782739Reviewed-by: Chris Palmer <palmer@chromium.org>
Reviewed-by: Peter Collingbourne <pcc@chromium.org>
Commit-Queue: Peter Collingbourne <pcc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518373}