[XEN] Fix kexec crash.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/crash.c b/xen/arch/x86/crash.c
index a5b0aeedf10f4cf52f708372b7a24216fe18e341..933846d1cdeb0387e938e32e7ab79922923414db 100644 (file)
--- a/xen/arch/x86/crash.c
+++ b/xen/arch/x86/crash.c
@@ -58,9 +58,9 @@ static int crash_nmi_callback(struct cpu_user_regs *regs, int cpu)
 static void smp_send_nmi_allbutself(void)
 {
     cpumask_t allbutself = cpu_online_map;
-
     cpu_clear(smp_processor_id(), allbutself);
-    send_IPI_mask(allbutself, APIC_DM_NMI);
+    if ( !cpus_empty(allbutself) )
+        send_IPI_mask(allbutself, APIC_DM_NMI);
 }
 
 static void nmi_shootdown_cpus(void)