On 03/31/20 09:56, Ard Biesheuvel wrote:
> On Mon, 30 Mar 2020 at 20:24, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>>
>> On Mon, 30 Mar 2020 at 20:12, Michael Kelley <mikelley@xxxxxxxxxxxxx> wrote:
>>>
>>> From: Ard Biesheuvel <ardb@xxxxxxxxxx> Sent: Monday, March 30, 2020 12:51 AM
>>>>
>>>> On Mon, 30 Mar 2020 at 09:50, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>>>>>
>>>>> On Mon, 30 Mar 2020 at 09:47, Leif Lindholm <leif@xxxxxxxxxxxx> wrote:
>>>>>>
>>>>>> On Sat, Mar 28, 2020 at 21:58:09 +0100, Ard Biesheuvel wrote:
>>>>>>> Commit 9f9223778ef3 ("efi/libstub/arm: Make efi_entry() an ordinary
>>>>>>> PE/COFF entrypoint") did some code refactoring to get rid of the
>>>>>>> EFI entry point assembler code, and in the process, it got rid of the
>>>>>>> assignment of image_addr to the value of _text. Instead, it switched
>>>>>>> to using the image_base field of the efi_loaded_image struct provided
>>>>>>> by UEFI, which should contain the same value.
>>>>>>>
>>>>>>> However, Michael reports that this is not the case: older GRUB builds
>>>>>>> corrupt this value in some way, and since we can easily switch back to
>>>>>>> referring to _text to discover this value, let's simply do that.
>>>>>>
>>>>>> It is not clear to me how "older GRUB builds" would differ here.
>>>>>> I think more investigation is needed before making that claim.
>>>>>> My suspicion is that some (old) version of non-upstream, shim-enabled
>>>>>> distro-specific build is playing a part.
>>>>>>
>>>>>> So, do we have the option for more detailed investigations, or can we
>>>>>> vague the claim up to say "some GRUB builds seen in the wild, based
>>>>>> on an upstream 2.02" or suchlike?
>>>>>>
>>>>>
>>>>> I've queued a fix that prints a nastygram if the value deviates from
>>>>> the expected one. Let's see if this triggers any reports.
>>>>
>>>> (/me looks at context)
>>>>
>>>> *This* is the fix that prints a nastygram.
>>>
>>> FWIW, I pulled the BOOTAA64.EFI and grubaa64.efi files from CentOS 7.6
>>> and CentOS 8.0 binary packages and tested both in my Hyper-V VM.
>>> Using strings | grep '2\.' to get version info, the CentOS 7.6 grubaa64.efi
>>> shows:
>>>
>>> User-Agent: GRUB 2.02~beta2
>>>
>>> The CentOS 8.0 grubaa64.efi shows:
>>>
>>> User-Agent: GRUB 2.03
>>>
>>> Both versions produce the FIRMWARE BUG warning when using Ard's
>>> latest patch. I'll assume the equivalent RHEL versions are the same.
>>> So we've got official distro releases that show the problem.
>>>
>>> As reported earlier, the BOOTAA64.EFI and grubaa64.efi from a
>>> Debian release (not exactly sure which one) do not produce the
>>> FIRMWARE BUG warning. The grubaa64.efi reports as 2.04-4.
>>>
>>
>> Thanks a lot Michael, that is really helpful.
>
> I could not reproduce the issue with Debian Stretch's
> 2.02~beta3-5+deb9u2, so it does appear to be RedHat's value add that
> is to blame here.
>
> @Laszlo: TL;DR RedHat's GRUB for arm64 appears to clobber the
> image_base field of the efi_loaded_image struct passed to the kernel.
> Could you please recommend a way to report this?
Yes. I seem to recall that you already have an account at
<https://bugzilla.redhat.com/>. Please log in, then go to the following
link:
https://bugzilla.redhat.com/enter_bug.cgi?product=Red%20Hat%20Enterprise%20Linux%208
In the "Component" field, please enter "grub2", then fill in Summary /
Description / etc.
Please be thorough, as if you wanted me to reproduce the issue :)
After filing the bug, please send the BZ link to me (or add me to the
bug's CC list), so I can ping some RH bootloader folks directly.
Thanks!
Laszlo
