On Tue, Nov 14, 2023 at 11:22:16PM +0000, Edgecombe, Rick P wrote:

On Tue, 2023-11-14 at 20:05 +0000, Mark Brown wrote:

quoted

+config ARCH_HAS_USER_SHADOW_STACK
+       bool
+       help
+         The architecture has hardware support for userspace shadow
call
+          stacks (eg, x86 CET, arm64 GCS, RISC-V Zisslpcfi).

I feel like normally a patch like this should come with the second
feature that gets enabled. (i.e. arm or riscv). Especially since the
comment lists currently unsupported features. I think something like
this got nixed by an x86 maintainer earlier, but that was before these
other features were getting pushed.

I don't have a strong objection to having it ahead of the other
features though and it is nice to remove X86 defines out of core code.

Given that the GCS patches are on the list and relatively
uncontroversial it does seem reasonable to carry this - I'm only able to
test this in the context of having both serieses applied!