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Date: Thu, 5 Jan 2023 09:11:27 +0100
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Alexander Graf <agraf@csgraf.de>
Cc: Ard Biesheuvel <ardb@kernel.org>,
	dann frazier <dann.frazier@canonical.com>, devel@edk2.groups.io,
	Leif Lindholm <quic_llindhol@quicinc.com>
Subject: Re: [edk2-devel] [PATCH v3 03/16] ArmVirtPkg: make EFI_LOADER_DATA non-executable
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  Hi,

> To clarify, I mean something like the patch below, but with an additional
> callback notification similar to the Emu one in LoadImage(), so that we can
> make sure we only enable the quirk when we load a known-bad grub binary.
> That way we still force distros to ship fixed versions of their code, but
> enable old code to continue running.

> +  /* TODO: Only run this as part of a notify callback in ImageLoad() when
> we
> +           load a grub binary with a known-broken hash */
> +  BOOLEAN is_broken_grub = TRUE;
> +  if (is_broken_grub) {
> +    RealAllocatePages = gBS->AllocatePages;
> +    gBS->AllocatePages = AllocatePagesForceLoaderCode;
> +  }

You left out the hard part, which is the list of hashes.  And I suspect
you underestimate the number of broken grub binaries in the wild ...

take care,
  Gerd