From: H. Peter Anvin <hpa@linux.intel.com>
Date: Tue, 13 Jul 2010 21:57:50 +0000 (-0700)
Subject: x86, alternatives: BUG on encountering an invalid CPU feature number
X-Git-Tag: v2.6.36-rc1~510^2
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=3b770a2128423a687e6e9c57184a584fb4ba4c77;p=net-next-2.6.git

x86, alternatives: BUG on encountering an invalid CPU feature number

Make the alternatives-patching code BUG on encountering an invalid CPU
feature number.  Should have done this a long time ago.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Yinghai Lu <yinhai@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <tip-df378ccfc4dd04e263426ad805516915874774aa@git.kernel.org>
---

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 70237732a6c..f65ab8b014c 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -214,6 +214,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 		u8 *instr = a->instr;
 		BUG_ON(a->replacementlen > a->instrlen);
 		BUG_ON(a->instrlen > sizeof(insnbuf));
+		BUG_ON(a->cpuid >= NCAPINTS*32);
 		if (!boot_cpu_has(a->cpuid))
 			continue;
 #ifdef CONFIG_X86_64