The root cause of this problem is that the order in which errata and cpu features are evaluated and enabled is reversed. On ThunderX boxes that have erratum 27456 enable, KPTI needs to be turned off to prevent I-cache clobbering. But due to the reversed order, the callback to enable KPTI is registered before the kernel determines that KPTI should be off. And when the CPUs are onlined the callback is executed, resulting in *both* KPTI and the erratum being enabled which results in all sorts of weird and inconsistent issues.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1857074 Title: Cavium ThunderX CN88XX Panic : Unknown reason To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857074/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
