[SRU][Xenial][Yakkety][PATCH 0/1] UBUNTU: SAUCE: (no-up) x86/topology: Handle CPUID bogosity gracefully

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1573231

== Xenial and Yakkety Justification ==
Multiple users have reported a Kernel Panic on EC2 After Upgrading from 14.04 to 16.04.
After a bisect it was found that commit 8ae10f463b introduced this bug.  

The panic is due to a a divide error. The divide error happens because XEN is supplying bogus 
data in the CPUID.

Thomas Gleixner created a patch to solve this bug.  The patch is in the x86 tree and has
been submitted for inclusion in mainline.

This patch is marked as SAUCE and (no-up) because it has not landed in mainline as 
of yet.  However, it is being submitted for inclusin in Ubunte due to the critical
nature of the bug.



== Fix ==
https://lkml.org/lkml/2016/5/7/49:

Commit-ID:  56402d63eefe22179f7311a51ff2094731420406
Gitweb:     http://git.kernel.org/tip/56402d63eefe22179f7311a51ff2094731420406
Author:     Thomas Gleixner <tglx at linutronix.de>
AuthorDate: Fri, 6 May 2016 20:48:16 +0200
Committer:  Thomas Gleixner <tglx at linutronix.de>
CommitDate: Sat, 7 May 2016 10:06:55 +0200

x86/topology: Handle CPUID bogosity gracefully



== Test Case ==
A test kernel was built with this patch and tested by multiple AWS users.
It was reported that the test kernel resolved the bug.


Thomas Gleixner (1):
  x86/topology: Handle CPUID bogosity gracefully

 arch/x86/kernel/smpboot.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.7.4