Re: [PATCH] MdeModulePkg/PciHostBridge: Update Mem and PMem Limit Checks

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Thu, 23 Apr 2020 at 12:43, Wasim Khan <wasim.khan@nxp.com> wrote:
>
> With Address Translation Support, it is possible and
> also correct that Mem and Pmem Limit cross the 4GB boundary.
> Update the checks so that Mem/PMem Limit should not cross 4GB
> from the Mem/PMem Base address.
>
> Signed-off-by: Wasim Khan <wasim.khan@nxp.com>
> ---
>  MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> index d304fae..9cf7e98 100644
> --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> @@ -117,8 +117,8 @@ CreateRootBridge (
>    // Make sure Mem and MemAbove4G apertures are valid
>    //
>    if (RESOURCE_VALID (&Bridge->Mem)) {
> -    ASSERT (Bridge->Mem.Limit < SIZE_4GB);
> -    if (Bridge->Mem.Limit >= SIZE_4GB) {
> +    ASSERT (Bridge->Mem.Limit < (Bridge->Mem.Base + SIZE_4GB));
> +    if (Bridge->Mem.Limit >= (Bridge->Mem.Base + SIZE_4GB)) {
>        return NULL;
>      }
>    }
> @@ -129,8 +129,8 @@ CreateRootBridge (
>      }
>    }
>    if (RESOURCE_VALID (&Bridge->PMem)) {
> -    ASSERT (Bridge->PMem.Limit < SIZE_4GB);
> -    if (Bridge->PMem.Limit >= SIZE_4GB) {
> +    ASSERT (Bridge->PMem.Limit < (Bridge->PMem.Base + SIZE_4GB));
> +    if (Bridge->PMem.Limit >= (Bridge->PMem.Base + SIZE_4GB)) {
>        return NULL;
>      }
>    }
> --
> 2.7.4
>

This is not the right fix.

The translation offset should be taken into account for these checks