From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: Regression from efi: call get_event_log before ExitBootServices Date: Wed, 7 Mar 2018 12:16:23 +0100 Message-ID: <185d1c06-c379-ee7d-496b-2f4e49f8c9a3@redhat.com> References: <01000161fc0b4755-df0621f4-ab5d-479a-b425-adf98427a308-000000@email.amazonses.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Thiebaud Weksteen , jeremy@jcline.org Cc: Javier Martinez Canillas , Jarkko Sakkinen , linux-efi@vger.kernel.org, linux-integrity@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org List-Id: tpmdd-devel@lists.sourceforge.net Hi, On 07-03-18 09:41, Thiebaud Weksteen wrote: > Hi, > > Thanks for testing and sending this report! This patch relies heavily on > the functions exposed by the firmware. My first guess would be that some of > these may not be implemented correctly by the manufacturer. > > Could you share more information on this specific device? I've the same device as Jeremy, but I just tried a 4.16-rc3 kernel and I'm not seeing this problem, BIOS settings all default (I loaded the BIOS defaults to make sure). > Do you have any link to the manufacturer website (I found [1] but it is > based on an ARM CPU)? > Do you have the option to update your firmware? Is a copy of the firmware > available from the manufacturer? This is a really cheap Windows tablet which was given away for free in the Netherlands with some home-schooling language courses, or something similar. Both mine and Jeremy tablets come from a website in the Netherlands where people can buy/sell used goods. Most relevant for this discussion I guess is that this device is based on a Bay Trail Z3735G SoC, on which according to the internets: https://embedded.communities.intel.com/thread/7868 The TPM 2.0 it contains is implemented as part of the TXE firmware. Since I cannot reproduce I'm thinking that maybe Jeremy actually has some log messages in the TPM log, where as mine is empty. Is there a way to make sure some messages are in there? Regards, Hans > On your side, I assume no error message got displayed on the screen when > booting. Would you be able to try to boot in an UEFI shell [2] and execute > the command "dh -v"? > > Thanks, > Thiebaud > > [1] https://www.gp-electronic.nl/product/7inchtablet > [2] > https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface#UEFI_Shell > > On Tue, Mar 6, 2018 at 5:00 PM Jeremy Cline wrote: > >> Hi folks, > >> Commit 33b6d03469b2 ("efi: call get_event_log before ExitBootServices") >> causes my GP-electronic T701 tablet to hang when booting. Reverting the >> patch series or hiding the TPM in the BIOS fixes the problem. > >> I've never fiddled with TPMs before so I'm not sure what what debugging >> information to provide. It's got an Atom Z3735G and the UEFI firmware is >> InsydeH20 version BYT70A.YNCHENG.WIN.007. > > >> Regards, >> Jeremy