linux-kernel - Re: Regression from efi: call get_event

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Date:   Tue, 13 Mar 2018 13:43:19 +0000
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Jeremy Cline <jeremy@...ine.org>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        Thiebaud Weksteen <tweek@...gle.com>,
        Javier Martinez Canillas <javierm@...hat.com>,
        Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
        linux-efi@...r.kernel.org, linux-integrity@...r.kernel.org,
        tpmdd-devel@...ts.sourceforge.net,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Regression from efi: call get_event_log before ExitBootServices

On 13 March 2018 at 13:41, Jeremy Cline <jeremy@...ine.org> wrote:
> On 03/13/2018 03:59 AM, Ard Biesheuvel wrote:
>> On 13 March 2018 at 07:47, Hans de Goede <hdegoede@...hat.com> wrote:
>>> Hi,
>>>
>>>
>>> On 12-03-18 20:55, Thiebaud Weksteen wrote:
>>>>
>> ...
>>>>
>>>> Hans, you said you configured the tablet to use the 32-bit version of grub
>>>> instead
>>>> of 64. Why's that?
>>>
>>>
>>> Because this tablet, like (almost?) all Bay Trail hardware has a 32 bit
>>> UEFI,
>>> even though the processor is 64 bit capable (AFAIK 64 bit Windows drivers
>>> were
>>> not ready in time so all Bay Trail devices shipped with a 32 bit Windows).
>>>
>>> So this is running a 32 bit grub which boots a 64 bit kernel.
>>>
>>>> Jeremy, could you confirm if you are building the kernel in 64bit mode? Is
>>>> your Android install working? (that is, what happens if you boot
>>>> Boot0000)?
>>>
>>>
>>> AFAIK the kernel on Jeremy's tablet (which I initially installed) is 64 bit.
>>>
>>> Could the problem perhaps be that the new code for the TPM event-log is
>>> missing some handling to deal with running on a 32 bit firmware? I know the
>>> rest of the kernel has special code to deal with this.
>>>
>>
>> That is a very good point, and I missed that this is a 64-bit kernel
>> running on 32-bit UEFI.
>>
>> The TPM code does use efi_call_proto() directly, and now I am thinking
>> it is perhaps the allocate_pages() call that simply only initializes
>> the low 32-bits of log_tbl.
>>
>> Jeremy, could you please try initializing tcg2_protocol and log_tbl to
>> NULL at the start of the function?
>>
>
> That was it, it boots when those are initialized to NULL.
>

Thanks for confirming. I'll send out a patch.