linux-kernel - Re: [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-prev] [day] [month] [year] [list]

Message-ID: <50b2bf9b-d4c3-e469-1ef9-3d58b44f4de8@redhat.com>
Date:   Mon, 18 May 2020 12:52:47 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linmiaohe <linmiaohe@...wei.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:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH v2] KVM: VMX: replace "fall through" with "return" to
 indicate different case

On 19/02/20 03:45, linmiaohe wrote:
> 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:
> 

Queued, thanks.

Paolo