Re: [PATCH v3 46/66] linux-user: Split out do_prctl and subroutines

[Peter Maydell <peter.maydell@linaro.org>]

On Wed, 18 Aug 2021 at 20:39, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Since the prctl constants are supposed to be generic, supply
> any that are not provided by the host.
>
> Split out subroutines for PR_GET_FP_MODE, PR_SET_FP_MODE,
> PR_GET_VL, PR_SET_VL, PR_RESET_KEYS, PR_SET_TAGGED_ADDR_CTRL,
> PR_GET_TAGGED_ADDR_CTRL.  Return EINVAL for guests that do
> not support these options rather than pass them on to the host.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  linux-user/aarch64/target_syscall.h |  23 -
>  linux-user/mips/target_syscall.h    |   6 -
>  linux-user/mips64/target_syscall.h  |   6 -
>  linux-user/syscall.c                | 644 ++++++++++++++++------------

> +static abi_long do_prctl_get_fp_mode(CPUArchState *env)
> +{
> +#ifdef TARGET_MIPS
> +    abi_long ret = 0;
> +
> +    if (env->CP0_Status & (1 << CP0St_FR)) {
> +        ret |= PR_FP_MODE_FR;
> +    }
> +    if (env->CP0_Config5 & (1 << CP0C5_FRE)) {
> +        ret |= PR_FP_MODE_FRE;
> +    }
> +    return ret;
> +#else
> +    return -TARGET_EINVAL;
> +#endif
> +}

If we're going to refactor the prctl code, I think it would be
better to have architecture-specific prctl handling in
linux-user/$ARCH/prctl.c files rather than lots of target ifdefs
in syscall.c...

thanks
-- PMM