x87: fix x87 FPU stack depth check fail issue in TurboFan's exception handler

x87: fix x87 FPU stack depth check fail issue in TurboFan's exception handler

  Unstructured control flow caused by excpetion leads to a wrong x87 FPU stack
  state in TurboFan's exception handler.

  This patch is to reset the x87 FPU stack state when calling the TurboFan's exception
  handler from the CEntryStub.

BUG=

Committed: https://crrev.com/582ea68151b9a6bb31925f69e0bc29499044020e
Cr-Commit-Position: refs/heads/master@{#34109}

[zhengxing.li, 2016-02-18 02:05:03]

zhengxing.li@intel.com changed reviewers:
+ chunyang.dai@intel.com, weiliang.lin@intel.com

[zhengxing.li, 2016-02-18 02:05:04]

PTAL, thanks!

[Weiliang, 2016-02-18 08:51:55]

lgtm

[zhengxing.li, 2016-02-18 08:53:00]

The CQ bit was checked by zhengxing.li@intel.com

[commit-bot: I haz the power, 2016-02-18 08:53:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1702383005/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1702383005/40001

[commit-bot: I haz the power, 2016-02-18 10:36:37]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-02-18 10:37:08]

Description was changed from

==========
x87: fix x87 FPU stack depth check fail issue in TurboFan's exception handler

  Unstructured control flow caused by excpetion leads to a wrong x87 FPU stack
  state in TurboFan's exception handler.

  This patch is to reset the x87 FPU stack state when calling the TurboFan's
exception
  handler from the CEntryStub.

BUG=
==========

to

==========
x87: fix x87 FPU stack depth check fail issue in TurboFan's exception handler

  Unstructured control flow caused by excpetion leads to a wrong x87 FPU stack
  state in TurboFan's exception handler.

  This patch is to reset the x87 FPU stack state when calling the TurboFan's
exception
  handler from the CEntryStub.

BUG=

Committed: https://crrev.com/582ea68151b9a6bb31925f69e0bc29499044020e
Cr-Commit-Position: refs/heads/master@{#34109}
==========

[commit-bot: I haz the power, 2016-02-18 10:37:10]

Patchset 3 (id:??) landed as
https://crrev.com/582ea68151b9a6bb31925f69e0bc29499044020e
Cr-Commit-Position: refs/heads/master@{#34109}