From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 02/18] KVM: Fix overflow bug in overflow detection code Date: Thu, 26 Apr 2007 12:22:02 +0300 Message-ID: <11775793382198-git-send-email-avi@qumranet.com> References: <11775793382353-git-send-email-avi@qumranet.com> Cc: linux-kernel@vger.kernel.org, Eric Sesterhenn / Snakebyte , Avi Kivity To: kvm-devel@lists.sourceforge.net Return-path: In-Reply-To: <11775793382353-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Eric Sesterhenn / Snakebyte The expression sp - 6 < sp where sp is a u16 is undefined in C since 'sp - 6' is promoted to int, and signed overflow is undefined in C. gcc 4.2 actually warns about it. Replace with a simpler test. Signed-off-by: Eric Sesterhenn Signed-off-by: Avi Kivity --- drivers/kvm/vmx.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 61a6116..8c0115b 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1182,7 +1182,7 @@ static void inject_rmode_irq(struct kvm_vcpu *vcpu, int irq) u16 sp = vmcs_readl(GUEST_RSP); u32 ss_limit = vmcs_read32(GUEST_SS_LIMIT); - if (sp > ss_limit || sp - 6 > sp) { + if (sp > ss_limit || sp < 6 ) { vcpu_printf(vcpu, "%s: #SS, rsp 0x%lx ss 0x%lx limit 0x%x\n", __FUNCTION__, vmcs_readl(GUEST_RSP), -- 1.5.0.6