ubuntu-kernel-tests

  1. Bug #2051184
  2. Comment #2

Comment 2 for bug 2051184

Revision history for this message
Manuel Diewald (diewald) wrote :

From LP: #2052632

log_check/kernel_tainted tests will fail on AmpereOne based machines like c3a-standard-4 for focal:linux 5.4.0-168.186 and newer.

The warning was introduced with upstream commit

f41cab7a4653 arm64: Add AMPERE1 to the Spectre-BHB affected list

that came with upstream stable release v5.4.253 as part of Ubuntu-5.4.0-168.186: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2038652

Looking at the code, this warning will always be issued on AMPERE1 based machines but Spectre-BHB mitigation should be guaranteed regardless. The warning is issued because there is no case for loop iteration count 11 necessary for AMPERE1 CPUs in spectre_bhb_enable_mitigation().