[all-commits] [llvm/llvm-project] 69faae: [ARM][libcxxabi] Add PACBTI-M support to libcxxabi

[Ties Stuij via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 69faae2376c1a5beccdfbf103346354c68f3570c
      https://github.com/llvm/llvm-project/commit/69faae2376c1a5beccdfbf103346354c68f3570c
  Author: Ties Stuij <ties.stuij at arm.com>
  Date:   2021-12-10 (Fri, 10 Dec 2021)

  Changed paths:
    M libcxxabi/src/cxa_exception.cpp

  Log Message:
  -----------
  [ARM][libcxxabi] Add PACBTI-M support to libcxxabi

This change consists of just adding 'BTI' to the prologue of Arm assembly
functions, which is just the one: __cxa_end_cleanup

This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:

https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension

The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:

https://developer.arm.com/documentation/ddi0553/latest

The following people contributed to this patch:

- Mikhail Maltsev

Reviewed By: lenary, danielkiss

Differential Revision: https://reviews.llvm.org/D112432