On 21 June 2018 at 10:03, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Hi,
>
> On 21-06-18 09:57, Ard Biesheuvel wrote:
>>
>> On 21 June 2018 at 09:42, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>>>
>>> Commit 79832f0b5f71 ("efi/libstub/tpm: Initialize pointer variables to
>>> zero
>>> for mixed mode") fixes a problem with the tpm code on mixed mode (64 bit
>>> kernel on 32 bit UEFI), where 64-bit pointer variables are not fully
>>> initialized by the 32-bit EFI code.
>>>
>>> A simlar problem applies to the efi_physical_addr_t variables which
>>> are written by the get_event_log EFI call. Even though
>>> efi_physical_addr_t
>>> is 64 bit everywhere it seems that some 32 bit UEFI implementations only
>>> fill in the lower 32 bits when passed a pointer to an efi_physical_addr_t
>>> to fill.
>>>
>>> This commit initializes these to 0 to, to ensure the upper 32 bits are
>>> 0 in mixed mode. This fixes recent kernels sometimes hanging during
>>> early boot on mixed mode UEFI systems.
>>>
>>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>>> ---
>>> Changes in v2:
>>> -Change commit message to reflect that efi_physical_addr_t is 64 bit
>>> everywhere and some firmwares only filling the lower 32 bits is
>>> somewhat
>>> unexpected
>>
>>
>> Thanks Hans
>>
>> Queued in efi/next
>
>
> Thanks,
>
> I just realized I forgot to add a "Cc: stable@xxxxxxxxxxxxxxx", the problem
> of some BYT machines not booting about 50% of the times was introduced
> in 4.17.
>
> Given that this is a bugfix for this, it would be good to get this added to
> 4.18-rc# and 4.17.x
>
Fair enough. I will send it to Ingo as a fix instead.
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