x86: disable IRQs before doing anything on nmi_shootdown_cpus()

Impact: make nmi_shootdown_cpus() callable from preemptible context

We need to know on which CPU we are running on, and we don't want to be
preempted while doing this.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 17a41e055565..c3cd512484e5 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -577,6 +577,7 @@ static struct notifier_block crash_nmi_nb = {
 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 {
         unsigned long msecs;
+        local_irq_disable();
 
         /* Make a note of crashing cpu. Will be used in NMI callback.*/
         crashing_cpu = safe_smp_processor_id();