Re: [PATCH v2 10/17] linux-user/aarch64: Implement PR_MTE_TCF and PR_MTE_TAG

[Peter Maydell]

On Fri, 5 Jun 2020 at 05:17, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> These prctl fields are required for the function of MTE.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

This API doesn't seem to be in the upstream kernel yet, right?

> +                    /*
> +                     * Write PR_MTE_TCF to SCTLR_EL1[TCF0].
> +                     * Note that the syscall values are consistent with hw.
> +                     */
> +                    env->cp15.sctlr_el[1] =
> +                        deposit64(env->cp15.sctlr_el[1], 38, 2,
> +                                  arg2 >> TARGET_PR_MTE_TCF_SHIFT);

This actually will be per-thread since each linux-user thread has
its own CPU. You probably need to do something to make it be
inherited across clone and fork, though (assuming those are
the required semantics).

thanks
-- PMM