From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tiejun Chen Subject: [RFC][PATCH 1/2] kvm: x86: mmu: return zero if s > e in rsvd_bits() Date: Fri, 14 Nov 2014 17:31:27 +0800 Message-ID: <1415957488-27490-1-git-send-email-tiejun.chen@intel.com> Cc: kvm@vger.kernel.org To: pbonzini@redhat.com Return-path: Received: from mga11.intel.com ([192.55.52.93]:27734 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754643AbaKNJgg (ORCPT ); Fri, 14 Nov 2014 04:36:36 -0500 Sender: kvm-owner@vger.kernel.org List-ID: In some real scenarios 'start' may not be less than 'end' like maxphyaddr = 52. Signed-off-by: Tiejun Chen --- arch/x86/kvm/mmu.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index bde8ee7..0e98b5e 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -58,6 +58,8 @@ static inline u64 rsvd_bits(int s, int e) { + if (unlikely(s > e)) + return 0; return ((1ULL << (e - s + 1)) - 1) << s; } -- 1.9.1