Use mach_override to intercept all newly registered malloc zones.

Use mach_override to intercept all newly registered malloc zones.

mach_override is required for two reasons:
  1) There is no signal emitted when a new malloc zone is registered.
  Intercepting all malloc zones without mach_override requires polling, and the
  interception will not happen immediately at registration.
  2) Polling requires Chrome to call malloc_get_all_zones, which is not thread
  safe and has undefined behavior if a zone is registered or deregistered during
  container traversal.

BUG=693237

[erikchen, 2017-02-27 00:16:20]

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

[erikchen, 2017-02-27 00:16:29]

Description was changed from

==========
Use mach_override to intercept all newly registered malloc zones.

mach_override is required for two reasons:
  1) There is no signal emitted when a new malloc zone is registered.
  Intercepting all malloc zones without mach_override requires polling, and the
  interception will not happen immediately at registration.
  2) Polling requires Chrome to call malloc_get_all_zones, which is not thread
  safe and has undefined behavior is a zone is registered or deregistered during
  container traversal.

BUG=693237
==========

to

==========
Use mach_override to intercept all newly registered malloc zones.

mach_override is required for two reasons:
  1) There is no signal emitted when a new malloc zone is registered.
  Intercepting all malloc zones without mach_override requires polling, and the
  interception will not happen immediately at registration.
  2) Polling requires Chrome to call malloc_get_all_zones, which is not thread
  safe and has undefined behavior if a zone is registered or deregistered during
  container traversal.

BUG=693237
==========

[commit-bot: I haz the power, 2017-02-27 00:16:34]

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, 2017-02-27 01:56:43]

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

[commit-bot: I haz the power, 2017-02-27 01:56:44]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-02-27 19:27:04]

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

[erikchen, 2017-02-27 19:27:44]

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

[commit-bot: I haz the power, 2017-02-27 19:27:54]

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, 2017-02-27 20:34:02]

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

[commit-bot: I haz the power, 2017-02-27 20:34:03]

Dry run: Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[erikchen, 2017-02-27 20:57:43]

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

[commit-bot: I haz the power, 2017-02-27 20:58:24]

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, 2017-02-27 21:54:39]

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

[commit-bot: I haz the power, 2017-02-27 21:54:40]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-02-28 01:43:31]

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

[commit-bot: I haz the power, 2017-02-28 01:44:20]

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

[erikchen, 2017-02-28 02:25:34]

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

[commit-bot: I haz the power, 2017-02-28 02:26:02]

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, 2017-02-28 05:24:12]

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

[commit-bot: I haz the power, 2017-02-28 05:24:13]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-01 00:36:04]

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

[commit-bot: I haz the power, 2017-03-01 00:36:54]

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, 2017-03-01 01:05:04]

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

[commit-bot: I haz the power, 2017-03-01 01:05:05]

Dry run: Try jobs failed on following builders:
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[erikchen, 2017-03-01 01:14:28]

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

[commit-bot: I haz the power, 2017-03-01 01:15:10]

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, 2017-03-01 02:35:02]

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

[commit-bot: I haz the power, 2017-03-01 02:35:03]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-01 03:02:22]

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

[commit-bot: I haz the power, 2017-03-01 03:03:43]

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

[erikchen, 2017-03-01 03:07:24]

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

[commit-bot: I haz the power, 2017-03-01 03:08:22]

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, 2017-03-01 04:17:18]

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

[commit-bot: I haz the power, 2017-03-01 04:17:19]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-01 18:35:58]

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

[commit-bot: I haz the power, 2017-03-01 18:36:27]

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, 2017-03-01 19:36:54]

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

[commit-bot: I haz the power, 2017-03-01 19:36:55]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-01 20:27:05]

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

[commit-bot: I haz the power, 2017-03-01 20:27:45]

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, 2017-03-01 21:41:47]

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

[commit-bot: I haz the power, 2017-03-01 21:41:48]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-01 22:09:39]

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

[commit-bot: I haz the power, 2017-03-01 22:10:10]

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, 2017-03-01 23:22:25]

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

[commit-bot: I haz the power, 2017-03-01 23:22:26]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2017-03-02 01:23:56]

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

[commit-bot: I haz the power, 2017-03-02 01:25:00]

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, 2017-03-02 01:35:14]

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

[commit-bot: I haz the power, 2017-03-02 01:35:16]

Dry run: Try jobs failed on following builders:
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-simulator-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator-xco...)
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[erikchen, 2017-03-02 01:59:20]

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

[commit-bot: I haz the power, 2017-03-02 02:00:39]

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, 2017-03-02 05:51:43]

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

[commit-bot: I haz the power, 2017-03-02 05:51:44]

Dry run: Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[erikchen, 2017-03-02 18:04:35]

erikchen@chromium.org changed reviewers:
+ mark@chromium.org, primiano@chromium.org

[erikchen, 2017-03-02 18:04:36]

primiano, mark: Please review.

[Mark Mentovai, 2017-03-02 18:31:34]

NAK. No more mach_override. We need to stop writing over program text. I think
we’re only using it in CFBundleBlocker now, and we should get rid of that as
soon as we can too.

[erikchen, 2017-03-02 18:32:24]

On 2017/03/02 18:31:34, Mark Mentovai wrote:
> NAK. No more mach_override. We need to stop writing over program text. I think
> we’re only using it in CFBundleBlocker now, and we should get rid of that as
> soon as we can too.

Perhaps you could discuss and look at alternatives with myself and rsesek@? 

https://bugs.chromium.org/p/chromium/issues/detail?id=693237#c9