Re: [PATCH 3/3] ArmPkg/OpteeLib: Map shared communication buffer non-executable

["Leif Lindholm" <quic_llindhol@quicinc.com>]

On Mon, Jun 26, 2023 at 10:36:44 +0200, Ard Biesheuvel wrote:
> The OP-TEE secure OS exposes a non-secure memory region for
> communication between the secure OS itself and any clients in the
> non-secure firmware. This memory is writable by non-secure and is not
> used for code only data, and so it should be mapped non-executable.
> 
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

This looks straightforward enough (and an important safety
improvement), but adding Sumit on cc as original author.

>From my side, for the series:
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>

> ---
>  ArmPkg/Library/OpteeLib/Optee.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/ArmPkg/Library/OpteeLib/Optee.c b/ArmPkg/Library/OpteeLib/Optee.c
> index 46464f17ef06653e..3acf172b68a2d34c 100644
> --- a/ArmPkg/Library/OpteeLib/Optee.c
> +++ b/ArmPkg/Library/OpteeLib/Optee.c
> @@ -86,7 +86,12 @@ OpteeSharedMemoryRemap (
>      return EFI_BUFFER_TOO_SMALL;
>    }
>  
> -  Status = ArmSetMemoryAttributes (PhysicalAddress, Size, EFI_MEMORY_WB, 0);
> +  Status = ArmSetMemoryAttributes (
> +             PhysicalAddress,
> +             Size,
> +             EFI_MEMORY_WB | EFI_MEMORY_XP,
> +             0
> +             );
>    if (EFI_ERROR (Status)) {
>      return Status;
>    }
> -- 
> 2.39.2
>