[PATCH] arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks

[Will Deacon]

On Tue, 13 Oct 2020 22:24:30 -0700, Peter Collingbourne wrote:
> It doesn't make sense to issue prctl(PR_PAC_RESET_KEYS) on a
> compat task because the 32-bit instruction set does not offer PAuth
> instructions. For consistency with other 64-bit only prctls such as
> {SET,GET}_TAGGED_ADDR_CTRL, reject the prctl on compat tasks.
> 
> Although this is a userspace-visible change, maybe it isn't too late
> to make this change given that the hardware isn't available yet and
> it's very unlikely that anyone has 32-bit software that actually
> depends on this succeeding.

Applied to arm64 (for-next/core), thanks!

[1/1] arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks
      https://git.kernel.org/arm64/c/de7ae1c57273

Please check my changes if you get a chance.

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
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