From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E0A4C4320A for ; Mon, 9 Aug 2021 17:06:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D78860C51 for ; Mon, 9 Aug 2021 17:06:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233853AbhHIRGU (ORCPT ); Mon, 9 Aug 2021 13:06:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229877AbhHIRGS (ORCPT ); Mon, 9 Aug 2021 13:06:18 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 28E8FC0613D3 for ; Mon, 9 Aug 2021 10:05:57 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id gz13-20020a17090b0ecdb0290178c0e0ce8bso443570pjb.1 for ; Mon, 09 Aug 2021 10:05:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=N7MkMqODLMj3T1NXlpOTDzU2vHrNeFZAgg8Mo4BnxXs=; b=iy704fzF1WuCsB5tcbjR5QKsPL5hnZbfbqDjSUv26AmmK3U/Cj6l40QO2XS5/nmLn/ 9UGYJ/rkqg5vfjA98pwFWK00HWvBsrVlTBQiR65UYgqvQVFvsqdFKZQZLjkTuExlTABE KJbsozSvF1dSjr425fOHT4GqpgkKXm/Eidpsm38eYaJZe5L4HOpXfPzS604gMQXKPk6H qW/P69tl1K4QM6HQGQi4vlKjyfQnC+nAVXNxPyi7YSHyRKbvhDiH77tW1CMpyHXbNde2 zKA6rrSsdVpgkN3CHqYttXeXxfzirGKs1yMR0LOg9QF1lEn8+GjvtEeQA2XSm75Nmfgq peWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=N7MkMqODLMj3T1NXlpOTDzU2vHrNeFZAgg8Mo4BnxXs=; b=d+O+0GjtFMWsk719ceoKmreoCIAci9FE+ytqn4ukAT1MLYcgypPLhixyxp6p9YLgoh Tht21l684kxJ4X15XfvyQIOCb+bjd30qnACr5D1sneXSvmWop0oj5sbdlwIzJ0j3GwWg byElQxZ/QqDF7j/qaLutvqGw+9GqNtLm+6GhiJXMxlJxdnINjVuEfh8SHAyg2cO8uAOb d3A+hqSaWPe03Q/5vrvJqdcu5iraUPG2vOlCAOGEyb2RiIUgJ1reXq/9zCZGdP84uU5r //cZxfesyXjmTWTN79K3wNMfPkEG0mkBkH/Xa2tnm8sol03QgeB8nxeY0DxZ6BNDfKYl j44A== X-Gm-Message-State: AOAM531p05OKhXGvcW9wcJBL7FWlidnDJoR2U17Tf+3In+ha24vVaD3C HD7zg9yeVjbwrRqTavmXvm8vZQ== X-Google-Smtp-Source: ABdhPJyKqEllVhCXTU2xATl7Pge82E/AWpZaqZpmLpH5NGgCRl654KTZF6HN2xqA5KEsvfIcQkSe/w== X-Received: by 2002:a63:4c0e:: with SMTP id z14mr251057pga.427.1628528756567; Mon, 09 Aug 2021 10:05:56 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id a8sm24541915pgd.50.2021.08.09.10.05.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Aug 2021 10:05:55 -0700 (PDT) Date: Mon, 9 Aug 2021 17:05:51 +0000 From: Sean Christopherson To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kernel test robot Subject: Re: [PATCH] KVM: x86: remove dead initialization Message-ID: References: <20210809110120.3237065-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210809110120.3237065-1-pbonzini@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 09, 2021, Paolo Bonzini wrote: > hv_vcpu is initialized again a dozen lines below, so remove the > initializer. Eewwww. It's not just dead code, it's code that could potentially lead to dereferncing a NULL pointer and/or a stale pointer. The second initialization of the local hv_vcpu happens after a conditional call to kvm_hv_vcpu_init(). Maybe update the changelog to clarify why the second initialization absolutely must be kept? For the code: Reviewed-by: Sean Christopherson > Reported-by: kernel test robot > Signed-off-by: Paolo Bonzini > --- > arch/x86/kvm/hyperv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index e9582db29a99..2da21e45da99 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -1968,7 +1968,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool > void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu) > { > struct kvm_cpuid_entry2 *entry; > - struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); > + struct kvm_vcpu_hv *hv_vcpu; > > entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0); > if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) { > -- > 2.27.0 >