From: Ingo Molnar <mingo@kernel.org>
Date: Mon, 7 May 2012 17:19:56 +0000 (+0200)
Subject: x86/apic: Fix UP boot crash
X-Git-Tag: v2.6.39-400.9.0~543^2~9^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=56262b29ee04572a264ed5faf3e1068a8abbdca8;p=users%2Fjedix%2Flinux-maple.git

x86/apic: Fix UP boot crash

Commit 31b3c9d72340 ("xen/x86: Implement x86_apic_ops") implemented
this:

... without considering that on UP the function pointer might be NULL.

Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/n/tip-3pfty0ml4yp62phbkchichh0@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 45ac94480260..0cc341d34d93 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1022,7 +1022,8 @@ void __init setup_arch(char **cmdline_p)
 	init_cpu_to_node();
 
 	init_apic_mappings();
-	x86_io_apic_ops.init();
+	if (x86_io_apic_ops.init)
+		x86_io_apic_ops.init();
 
 	kvm_guest_init();