tree be435c048dd5866524c4aaa7edc86e7893e38fde
parent a6211468563129997e9f57fcbac179565e8a8610
author John Brawn <john.brawn@arm.com> 1723112409 +0100
committer Copybara-Service <copybara-worker@google.com> 1723112765 -0700

[libunwind] Fix problems caused by combining BTI and GCS (#102322)

The libunwind assembly files need adjustment in order to work correctly
when both BTI and GCS are both enabled (which will be the case when
using -mbranch-protection=standard):
* __libunwind_Registers_arm64_jumpto can't use br to jump to the return
location, instead we need to use gcspush then ret.
* Because we indirectly call __libunwind_Registers_arm64_jumpto it needs
to start with bti jc.
 * We need to set the GCS GNU property bit when it's enabled.

---------

Co-authored-by: Daniel Kiss <daniel.kristof.kiss@gmail.com>
GitOrigin-RevId: 39529107b46032ef0875ac5b809ab5b60cd15a40