x86: fix early panic with boot option "nosmp"
Impact: fix boot crash with numcpus=0 on certain systems
Fix early exception in __get_smp_config with nosmp.
Bail out early when there is no MP table.
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index f98f4e1..0f4c1fd 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -604,6 +604,9 @@
printk(KERN_INFO "Using ACPI for processor (LAPIC) "
"configuration information\n");
+ if (!mpf)
+ return;
+
printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
mpf->mpf_specification);
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)