Re: [PATCH v3 10/21] linux-user: Fix guest_addr_valid vs reserved_va

[Peter Maydell]

On Fri, 15 Jan 2021 at 22:47, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> We must always use GUEST_ADDR_MAX, because even 32-bit hosts can
> use -R <reserved_va> to restrict the memory address of the guest.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  include/exec/cpu_ldst.h | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h
> index 4e6ef3d542..e62f4fba00 100644
> --- a/include/exec/cpu_ldst.h
> +++ b/include/exec/cpu_ldst.h
> @@ -72,11 +72,10 @@ typedef uint64_t abi_ptr;
>  /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */
>  #define g2h(x) ((void *)((uintptr_t)(abi_ptr)(x) + guest_base))
>
> -#if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS
> -#define guest_addr_valid(x) (1)
> -#else
> -#define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)
> -#endif
> +static inline bool guest_addr_valid(abi_ulong x)
> +{
> +    return x <= GUEST_ADDR_MAX;
> +}

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Looking back at patch 9 -- if we always check against
GUEST_ADDR_MAX here, should we also do that for h2g_valid(),
or are the two uses different ?
(The v2->v3 changes list for patch 9 suggests we may have
had this discussion previously, but I forget the details...)

thanks
-- PMM