On Wed, 16 Aug 2023 19:40:07 +0100, Mark Brown wrote:
> When the value of ZT is set via ptrace we don't disable traps for SME.
> This means that when a the task has never used SME before then the value
> set via ptrace will never be seen by the target task since it will
> trigger a SME access trap which will flush the register state.
>
> Disable SME traps when setting ZT, this means we also need to allocate
> storage for SVE if it is not already allocated, for the benefit of
> streaming SVE.
>
> [...]
Applied to arm64 (for-next/fixes), thanks!
[1/1] arm64/ptrace: Ensure that the task sees ZT writes on first use
https://git.kernel.org/arm64/c/2f43f549cd0b
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Catalin