Re: [PATCH] ArmPkg/ArmMmuLib ARM: disregard high memory when setting permissions

[Leif Lindholm <leif.lindholm@linaro.org>]

On Mon, Jan 07, 2019 at 07:56:49AM +0100, Ard Biesheuvel wrote:
> Ignore calls to ArmSetMemoryAttributes () when the region described
> is outside of the 32-bit addressable range. This memory is not
> mapped in the first place, and the current code does not deal with
> the high bits correctly, resulting in hangs.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

> ---
>  ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
> index 3b3b20aa9b78..bffab83d4fd0 100644
> --- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
> +++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
> @@ -744,6 +744,10 @@ ArmSetMemoryAttributes (
>    UINT64        ChunkLength;
>    BOOLEAN       FlushTlbs;
>  
> +  if (BaseAddress > (UINT64)MAX_ADDRESS - Length + 1) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
>    if (Length == 0) {
>      return EFI_SUCCESS;
>    }
> -- 
> 2.20.1
>