Messages in this thread | | | Subject | Re: 5.3 boot regression caused by 5.3 TPM changes | From | Hans de Goede <> | Date | Wed, 7 Aug 2019 23:55:26 +0200 |
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Hi,
On 05-08-19 18:01, Ard Biesheuvel wrote: > On Sun, 4 Aug 2019 at 19:12, Hans de Goede <hdegoede@redhat.com> wrote: >> >> Hi, >> >> On 04-08-19 17:33, Ard Biesheuvel wrote: >>> Hi Hans, >>> >>> On Sun, 4 Aug 2019 at 13:00, Hans de Goede <hdegoede@redhat.com> wrote: >>>> >>>> Hi All, >>>> >>>> While testing 5.3-rc2 on an Irbis TW90 Intel Cherry Trail based >>>> tablet I noticed that it does not boot on this device. >>>> >>>> A git bisect points to commit 166a2809d65b ("tpm: Don't duplicate >>>> events from the final event log in the TCG2 log") >>>> >>>> And I can confirm that reverting just that single commit makes >>>> the TW90 boot again. >>>> >>>> This machine uses AptIO firmware with base component versions >>>> of: UEFI 2.4 PI 1.3. I've tried to reproduce the problem on >>>> a Teclast X80 Pro which is also CHT based and also uses AptIO >>>> firmware with the same base components. But it does not reproduce >>>> there. Neither does the problem reproduce on a CHT tablet using >>>> InsideH20 based firmware. >>>> >>>> Note that these devices have a software/firmware TPM-2.0 >>>> implementation, they do not have an actual TPM chip. >>>> >>>> Comparing TPM firmware setting between the 2 AptIO based >>>> tablets the settings are identical, but the troublesome >>>> TW90 does have some more setting then the X80, it has >>>> the following settings which are not shown on the X80: >>>> >>>> Active PCR banks: SHA-1 (read only) >>>> Available PCR banks: SHA-1,SHA256 (read only) >>>> TPM2.0 UEFI SPEC version: TCG_2 (other possible setting: TCG_1_2 >>>> Physical Presence SPEC ver: 1.2 (other possible setting: 1.3) >>>> >>>> I have the feeling that at least the first 2 indicate that >>>> the previous win10 installation has actually used the >>>> TPM, where as on the X80 the TPM is uninitialized. >>>> Note this is just a hunch I could be completely wrong. >>>> >>>> I would be happy to run any commands to try and debug this >>>> or to build a kernel with some patches to gather more info. >>>> >>>> Note any kernel patches to printk some debug stuff need >>>> to be based on 5.3 with 166a2809d65b reverted, without that >>>> reverted the device will not boot, and thus I cannot collect >>>> logs without it reverted. >>>> >>> >>> Are you booting a 64-bit kernel on 32-bit firmware? >> >> Yes you are right, I must say that this is somewhat surprising >> most Cherry Trail devices do use 64 bit firmware (where as Bay Trail >> typically uses 32 bit). But I just checked efibootmgr output and it >> says it is booting: \EFI\FEDORA\SHIMIA32.EFI so yeah 32 bit firmware. >> >> Recent Fedora releases take care of this so seamlessly I did not >> even realize... >> > > OK, so we'll have to find out how this patch affects 64-bit code > running on 32-bit firmware. The only EFI call in that patch is > get_config_table(), which is not actually a EFI boot service call but > a EFI stub helper that parses the config table array in the EFI system > table.
Ok, the problem indeed is the new get_efi_config_table() helper, it does not make any calls, but it does interpret some structs which have different sized members depending on if the firmware is 32 or 64 bit.
I've prepared a patch fixing this which I will send out after this mail.
Regards,
Hans
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