x86: avoid early crash in disable_local_APIC()

E.g. when called due to an early panic.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 0f830e4..d19aa3a 100644 (file)
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -895,6 +895,10 @@ void disable_local_APIC(void)
 {
        unsigned int value;
 
+       /* APIC hasn't been mapped yet */
+       if (!apic_phys)
+               return;
+
        clear_local_APIC();
 
        /*