Re: [edk2-devel] [PATCH v4] ArmVirt: Allow memory attributes protocol to be disabled

["Laszlo Ersek" <lersek@redhat.com>]

On 12/12/23 11:42, Ard Biesheuvel wrote:
> On Tue, 12 Dec 2023 at 11:08, Gerd Hoffmann <kraxel@redhat.com> wrote:
>>
>> On Tue, Dec 12, 2023 at 09:36:00AM +0100, Ard Biesheuvel wrote:
>>> From: Ard Biesheuvel <ardb@kernel.org>
>>>
>>> Shim's PE loader uses the EFI memory attributes protocol in a way that
>>> results in an immediate crash when invoking the loaded image, unless the
>>> base and size of its executable segment are both aligned to 4k.
>>>
>>> If this is not the case, it will strip the memory allocation of its
>>> executable permissions, but fail to add them back for the executable
>>> region, resulting in non-executable code. Unfortunately, the PE loader
>>> does not even bother invoking the protocol in this case (as it notices
>>> the misalignment), making it very hard for system firmware to work
>>> around this by attempting to infer the intent of the caller.
>>>
>>> So let's introduce a QEMU command line option to indicate that the
>>> protocol should not be exposed at all, and a PCD to set the default for
>>> this option when it is omitted.
>>>
>>>   -fw_cfg opt/org.tianocore/UninstallMemAttrProtocol,string=y
>>
>> Tested-by: Gerd Hoffmann <kraxel@redhat.com>
>> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
>>
> 
> Thanks all - I've queued this up now.
> 

If it hasn't been merged yet, add:

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

thanks
Laszlo



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