File is empty when reading contents of /sys/class/misc/tpm0/devices/pcrs

[RSacramento]

This problem is observed randomly on a system that previously had the contents of the file present. It happens on a system running tboot, and qemu-kVM. As stated, during initial deployment and boot up, the file contains the PCR values (tpm) however, after some time, the file becomes empty. The only solution is to reboot the system.

I am using tboot 1.7, Ubuntu 12.04.2 LTS kernel 3.5.0-36-generic on a Romley platform x86_64 with qemu-1.0.0, libvirt 1.0.2.

Further investigation reveals (dmesg output), the error points to the tpm_tis timing out.

[ 18.012502] tpm_tis 00:0a: 1.2 TPM (device-id 0x0, rev-id 78)
[335872.663975] tpm_tis 00:0a: Operation Timed out
[335872.735917] tpm_tis 00:0a: tpm_transmit: tpm_recv: error -5
[598356.471981] tpm_tis 00:0a: tpm_transmit: tpm_send: error -5
[598412.438490] tpm_tis 00:0a: tpm_transmit: tpm_send: error -5
[598412.440376] tpm_tis 00:0a: tpm_transmit: tpm_send: error -5
[598412.442055] tpm_tis 00:0a: tpm_transmit: tpm_send: error -5
[2130096.482415] tpm_tis 00:0a: tpm_transmit: tpm_send: error -5

tpm_selftest shows that it is failing with an I/O error.

# tpm_selftest -l debugTspi_Context_Create success
Tspi_Context_Connect success
Tspi_Context_GetTpmObject success
Tspi_TPM_SelfTestFull failed: 0x00001087 - layer=tddl, code=0087 (135), I/O error
Tspi_Context_FreeMemory success
Tspi_Context_Close success

# tpm_takeownership -l debug -z -yTspi_Context_Create success
Tspi_Context_Connect success
Tspi_Context_GetTpmObject success
Tspi_GetPolicyObject success
Tspi_Policy_SetSecret success
Tspi_Context_CreateObject success
Tspi_GetPolicyObject success
Tspi_Policy_SetSecret success
Tspi_TPM_TakeOwnership failed: 0x00001087 - layer=tddl, code=0087 (135), I/O error
Tspi_Context_CloseObject success
Tspi_Context_FreeMemory success
Tspi_Context_Close success

On most occassions, this file contains the PCR values of the tpm.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1227378/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Paul White (paulw2u)]

Ubuntu 12.04 (precise) reached end-of-life on April 28, 2017.

With no response to comment #1 after almost 10 years and with the
Ubuntu release out of support for over six years I'm closing this
bugs report as 'Invalid'.