Re: [PATCH V4] arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption

From: Will Deacon
Date: Fri Jan 06 2023 - 12:51:27 EST


On Mon, 2 Jan 2023 11:46:51 +0530, Anshuman Khandual wrote:
> If a Cortex-A715 cpu sees a page mapping permissions change from executable
> to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers, on the
> next instruction abort caused by permission fault.
>
> Only user-space does executable to non-executable permission transition via
> mprotect() system call which calls ptep_modify_prot_start() and ptep_modify
> _prot_commit() helpers, while changing the page mapping. The platform code
> can override these helpers via __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION.
>
> [...]

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

[1/1] arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption
https://git.kernel.org/arm64/c/5db568e748f6

Cheers,
--
Will

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