[src/trunk]: src/sys/arch/x86/x86 PR/52266: Before access MSR[APICBASE], need...

[nonaka <nonaka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aa9eb3a3bf2e
branches:  trunk
changeset: 355096:aa9eb3a3bf2e
user:      nonaka <nonaka%NetBSD.org@localhost>
date:      Thu Jul 13 00:44:14 2017 +0000

description:
PR/52266: Before access MSR[APICBASE], need to check if APIC is present.

diffstat:

 sys/arch/x86/x86/lapic.c |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (28 lines):

diff -r 9d0e05d4247f -r aa9eb3a3bf2e sys/arch/x86/x86/lapic.c
--- a/sys/arch/x86/x86/lapic.c  Wed Jul 12 19:06:16 2017 +0000
+++ b/sys/arch/x86/x86/lapic.c  Thu Jul 13 00:44:14 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: lapic.c,v 1.59 2017/07/08 14:35:33 nonaka Exp $        */
+/*     $NetBSD: lapic.c,v 1.60 2017/07/13 00:44:14 nonaka Exp $        */
 
 /*-
  * Copyright (c) 2000, 2008 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: lapic.c,v 1.59 2017/07/08 14:35:33 nonaka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: lapic.c,v 1.60 2017/07/13 00:44:14 nonaka Exp $");
 
 #include "acpica.h"
 #include "ioapic.h"
@@ -237,7 +237,8 @@
 {
        uint64_t msr;
 
-       if (rdmsr_safe(MSR_APICBASE, &msr) == EFAULT)
+       if (!ISSET(cpu_feature[0], CPUID_APIC) ||
+           rdmsr_safe(MSR_APICBASE, &msr) == EFAULT)
                return false;
        return (msr & (APICBASE_EN | APICBASE_EXTD)) ==
            (APICBASE_EN | APICBASE_EXTD);