On 05/11/2021 08:55, Andrea Corallo via Gcc-patches wrote:
Hi all, this patch enables Branch Target Identification Armv8.1-M Mechanism [1]. This is achieved by moving and generalizing the Aarch64 "bti" pass so it can be used also by the Arm backend. The pass iterates through the instructions and adds the necessary BTI instructions at the beginning of every function and at every landing pads targeted by indirect jumps. Regressioned and arm-linux-gnu aarch64-linux-gnu bootstraped. Best Regards Andrea [1] <https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension>
I think this patch needs splitting into two parts. The first part is simply the restructuring of the existing aarch64 code (and function renaming - mostly aarch64 -> aarch) the second adds the new arm code. The first patch is essentially a nop but takes care of all the uninteresting changes that are needed to enable part two.
R.
