linux-kernel - [PATCH v2] KVM: VMX: replace "fall through" with "return" to indicate different case

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 19 Feb 2020 10:45:48 +0800
From:   linmiaohe <linmiaohe@...wei.com>
To:     <pbonzini@...hat.com>, <rkrcmar@...hat.com>,
        <sean.j.christopherson@...el.com>, <vkuznets@...hat.com>,
        <wanpengli@...cent.com>, <jmattson@...gle.com>, <joro@...tes.org>,
        <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
        <hpa@...or.com>
CC:     <linmiaohe@...wei.com>, <kvm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <x86@...nel.org>
Subject: [PATCH v2] KVM: VMX: replace "fall through" with "return" to indicate different case

From: Miaohe Lin <linmiaohe@...wei.com>

The second "/* fall through */" in rmode_exception() makes code harder to
read. Replace it with "return" to indicate they are different cases, only
the #DB and #BP check vcpu->guest_debug, while others don't care. And this
also improves the readability.

Suggested-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 arch/x86/kvm/vmx/vmx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a13368b2719c..5b8f024f06c2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4492,10 +4492,8 @@ static bool rmode_exception(struct kvm_vcpu *vcpu, int vec)
 			return false;
 		/* fall through */
 	case DB_VECTOR:
-		if (vcpu->guest_debug &
-			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
-			return false;
-		/* fall through */
+		return !(vcpu->guest_debug &
+			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP));
 	case DE_VECTOR:
 	case OF_VECTOR:
 	case BR_VECTOR:
-- 
2.19.1