Re: [PATCH 08/11] target/arm: Enforce PAN semantics in get_S1prot

[Peter Maydell]

On Tue, 3 Dec 2019 at 22:53, Richard Henderson
<address@hidden> wrote:
>
> If we have a PAN-enforcing mmu_idx, set prot == 0 if user_rw != 0.
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  target/arm/internals.h | 13 +++++++++++++
>  target/arm/helper.c    |  3 +++
>  2 files changed, 16 insertions(+)
>
> diff --git a/target/arm/internals.h b/target/arm/internals.h
> index 2408953031..ab3b436379 100644
> --- a/target/arm/internals.h
> +++ b/target/arm/internals.h
> @@ -893,6 +893,19 @@ static inline bool regime_is_secure(CPUARMState *env, 
> ARMMMUIdx mmu_idx)
>      }
>  }
>
> +static inline bool regime_is_pan(CPUARMState *env, ARMMMUIdx mmu_idx)
> +{
> +    switch (mmu_idx) {
> +    case ARMMMUIdx_Stage1_E1_PAN:
> +    case ARMMMUIdx_EL10_1_PAN:
> +    case ARMMMUIdx_EL20_2_PAN:
> +    case ARMMMUIdx_SE1_PAN:
> +        return true;
> +    default:
> +        return false;
> +    }
> +}
> +
>  /* Return the FSR value for a debug exception (watchpoint, hardware
>   * breakpoint or BKPT insn) targeting the specified exception level.
>   */
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 6c65dd799e..a1dbafb9b2 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -9444,6 +9444,9 @@ static int get_S1prot(CPUARMState *env, ARMMMUIdx 
> mmu_idx, bool is_aa64,
>      if (is_user) {
>          prot_rw = user_rw;
>      } else {
> +        if (user_rw && regime_is_pan(env, mmu_idx)) {
> +            return 0;
> +        }
>          prot_rw = simple_ap_to_rw_prot_is_user(ap, false);
>      }
>
> --
> 2.17.1
>
Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM