x86/topology: Handle CPUID bogosity gracefully
authorThomas Gleixner <tglx@linutronix.de>
Fri, 6 May 2016 18:48:16 +0000 (20:48 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Sat, 7 May 2016 08:06:55 +0000 (10:06 +0200)
commit56402d63eefe22179f7311a51ff2094731420406
tree0466e2d9dc3205256269aff0bebf137669aa5f3f
parent07837831047fb72856d1f61a726a4094397facd8
x86/topology: Handle CPUID bogosity gracefully

Joseph reported that a XEN guest dies with a division by 0 in the package
topology setup code. This happens if cpu_info.x86_max_cores is zero.

Handle that case and emit a warning. This does not fix the underlying XEN bug,
but makes the code more robust.

Reported-and-tested-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1605062046270.3540@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/smpboot.c