[PATCH v3 0/8] Implement assembly cortex-M PACBTI functionality

Hi all,

This patch series modifies hand-written assembly files for Arm targets,
conditionally enabling branch target identification as well as address
return signature and verification based on Armv8.1-M Pointer
Authentication [1] using ACLE feature test macros at compile-time [2].

The incorportaion of PACBTI functionality in function prologues/
epilogues is dictated by the arguments passed to the
`-mbranch-protection' flag at the time of Newlib compilation.

Regression tested on arm-none-eabi with and without MVE extension and
for Newlib and Newlib-nano.

[1]
<https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension>
[2] <https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros>

Regards,
Victor

Victor Do Nascimento (8):
  newlib: libc: define M-profile PACBTI-enablement macros
  newlib: libc: strcmp M-profile PACBTI-enablement
  newlib: libc: strlen M-profile PACBTI-enablement
  newlib: libc: memchr M-profile PACBTI-enablement
  newlib: libc: memcpy M-profile PACBTI-enablement
  newlib: libc: setjmp/longjmp M-profile PACBTI-enablement
  newlib: libc: aeabi_memmove M-profile PACBTI-enablement
  newlib: libc: aeabi_memset M-profile PACBTI-enablement

 .../libc/machine/arm/aeabi_memmove-thumb2.S   |  15 +-
 newlib/libc/machine/arm/aeabi_memset-thumb2.S |  12 +-
 newlib/libc/machine/arm/arm_asm.h             | 130 ++++++++++++++++++
 newlib/libc/machine/arm/memchr.S              |  34 ++++-
 newlib/libc/machine/arm/memcpy-armv7m.S       |  35 +++--
 newlib/libc/machine/arm/setjmp.S              |  33 ++++-
 newlib/libc/machine/arm/strcmp-arm-tiny.S     |   8 +-
 newlib/libc/machine/arm/strcmp-armv7.S        |  42 ++++--
 newlib/libc/machine/arm/strcmp-armv7m.S       |  24 ++--
 newlib/libc/machine/arm/strlen-armv7.S        |  16 ++-
 newlib/libc/machine/arm/strlen-thumb2-Os.S    |  14 +-
 11 files changed, 301 insertions(+), 62 deletions(-)

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2.36.1