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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 C523DC433E2 for ; Fri, 17 Jul 2020 00:20:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A34DA204EC for ; Fri, 17 Jul 2020 00:20:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="f+wrzPk6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726143AbgGQAUF (ORCPT ); Thu, 16 Jul 2020 20:20:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbgGQAUE (ORCPT ); Thu, 16 Jul 2020 20:20:04 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 606F2C061755; Thu, 16 Jul 2020 17:20:04 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id p205so8343637iod.8; Thu, 16 Jul 2020 17:20:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2FerGNFZKniOyRFjaMMBJDlV2XPDBsl8JaLwC0gfi7o=; b=f+wrzPk6yzAFgWypM0ttm/bz88d9IaZzRis5kK0Eg82y3tF0dYe+k5a4N/iohJ+icy fEthlTkf5JQC8a7kxhlUo4255wTDwmqU6lgIMBKiZ9gr4Z2xnWvSV2ERS6YkpEmAdL8I dHDO752UplWksHQed6DBxtBpHktstX55MpMHNGhY/cp+J5vzeLeHCnMvKklU5fS0jt18 nPp49+DQKOwQZkz46FVTUGy7h/umw2sj/fjz+agmH43PwHR69CcuAq3sntZ9P2CWgUaX D2XGBWyL3c0BBsyUmhDo/AyYb2Q+jNNwFSpSCOLPTVK7tB4lTPGrkReUPqbMh9SBoUaA /14w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2FerGNFZKniOyRFjaMMBJDlV2XPDBsl8JaLwC0gfi7o=; b=XQ3kwtS8jZAZ9pok03lggWMwcWaC3CszDocQCo9lAeQ3bQRKJ6F3bveNNjM2TR1r5y +jVx1tPd1dSeYKoMKw/c+2ZB4hlM8uQqw3ATnbP5p2ta0sclTWRMyacbnpiV4XFs+F9k wRWFr7E3q+QIHnW9I8YzwEdRfz93Bw2LBS1K903fj4BW0F0HE8TA/MhWnWLmYUZfXSWY lel5sjVZ7CPpEWls5U3WrdNxWcmO+8TA0OJpDrAenSSGLPWcZGoN+6WE7UNe7RBfWH3K XY5wk7T/nPhoZYJjoSlLFbETRZI3FNQgzpKk3hMHJP2Lw1BIpryCMbcPjv8J5AmJdszn GQnA== X-Gm-Message-State: AOAM530ABMdvo4iIMkApIfd4C+vhIZYYao6aXEHi0ZNr8gJRGLShRvDF kgG+76kXh+N/wsU2/Z+BWYojKpN8hGIDySXO9vI= X-Google-Smtp-Source: ABdhPJzJta5CGSAocN1NwUPeSiy2NdfZZdS1injlrEqZEkECIvwcAMeclHWbF2u2vMwrP7iKeAvo69aMuoNmmRi2bfQ= X-Received: by 2002:a5d:9c0e:: with SMTP id 14mr7033701ioe.109.1594945203608; Thu, 16 Jul 2020 17:20:03 -0700 (PDT) MIME-Version: 1.0 References: <20200712131003.23271-1-madhuparnabhowmik10@gmail.com> <20200712131003.23271-2-madhuparnabhowmik10@gmail.com> <20200712160856.GW9247@paulmck-ThinkPad-P72> In-Reply-To: From: Dexuan-Linux Cui Date: Thu, 16 Jul 2020 17:19:52 -0700 Message-ID: Subject: Re: [PATCH 2/2] kvm: mmu: page_track: Fix RCU list API usage To: Naresh Kamboju Cc: madhuparnabhowmik10@gmail.com, "Paul E. McKenney" , Josh Triplett , Joel Fernandes , Paolo Bonzini , rcu@vger.kernel.org, open list , X86 ML , kvm list , frextrite@gmail.com, lkft-triage@lists.linaro.org, Dexuan Cui , juhlee@microsoft.com Content-Type: text/plain; charset="UTF-8" Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On Thu, Jul 16, 2020 at 7:47 AM Naresh Kamboju wrote: > > On Sun, 12 Jul 2020 at 21:39, Paul E. McKenney wrote: > > > > On Sun, Jul 12, 2020 at 06:40:03PM +0530, madhuparnabhowmik10@gmail.com wrote: > > > From: Madhuparna Bhowmik > > > > > > Use hlist_for_each_entry_srcu() instead of hlist_for_each_entry_rcu() > > > as it also checkes if the right lock is held. > > > Using hlist_for_each_entry_rcu() with a condition argument will not > > > report the cases where a SRCU protected list is traversed using > > > rcu_read_lock(). Hence, use hlist_for_each_entry_srcu(). > > > > > > Signed-off-by: Madhuparna Bhowmik > > > > I queued both for testing and review, thank you! > > > > In particular, this one needs an ack by the maintainer. > > > > Thanx, Paul > > > > > arch/x86/kvm/mmu/page_track.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c > > > index a7bcde34d1f2..a9cd17625950 100644 > > > --- a/arch/x86/kvm/mmu/page_track.c > > > +++ b/arch/x86/kvm/mmu/page_track.c > > > @@ -229,7 +229,8 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > > > return; > > > > > > idx = srcu_read_lock(&head->track_srcu); > > > - hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) > > > + hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > > > + srcu_read_lock_held(&head->track_srcu)) > > x86 build failed on linux -next 20200716. > > arch/x86/kvm/mmu/page_track.c: In function 'kvm_page_track_write': > include/linux/rculist.h:727:30: error: left-hand operand of comma > expression has no effect [-Werror=unused-value] > for (__list_check_srcu(cond), \ > ^ > arch/x86/kvm/mmu/page_track.c:232:2: note: in expansion of macro > 'hlist_for_each_entry_srcu' > hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > ^~~~~~~~~~~~~~~~~~~~~~~~~ > arch/x86/kvm/mmu/page_track.c: In function 'kvm_page_track_flush_slot': > include/linux/rculist.h:727:30: error: left-hand operand of comma > expression has no effect [-Werror=unused-value] > for (__list_check_srcu(cond), \ > ^ > arch/x86/kvm/mmu/page_track.c:258:2: note: in expansion of macro > 'hlist_for_each_entry_srcu' > hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, > ^~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > make[3]: *** [arch/x86/kvm/mmu/page_track.o] Error 1 > > build link, > https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-next/DISTRO=lkft,MACHINE=intel-corei7-64,label=docker-lkft/815/consoleText > > -- > Linaro LKFT > https://lkft.linaro.org Hi, we're seeing the same building failure with the latest linux-next tree. Thanks, Dexuan