From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48A721CAAF for ; Sun, 12 May 2024 10:43:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715510608; cv=none; b=hL10Bk8A5WXsTAhWoEnr5XYqjvFZdbqnU2xAXONtJQe8KmgYqM4emh/bcuGsVGqeBzFT+Tgo8y2apmtdM4zzPv9U6hklvfnQAJwr9Q3gpuFH8oehrqf5P4uo/9k7qqhiHuurpfeEUkDnirDObPr2TiEBBXcBrcyOmaUzI6uUkcU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715510608; c=relaxed/simple; bh=0rdr5+9oRPkVDvU6kbrzwQtN/Z+LPqctRKzqAJ8FT6w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=khBrVenHodJnlEI1R9/ICKCteQR66KldH54yF1Y5tcpWkDv3NXtdANnmG9NZ2uwFcfiGZ9N+TDQ95JuQPWGQj5MQ/QpL/t86Al+ZzkFbc8iqZzn4QE1+zh56hFMHyh5ztWVdPOwCbybiefTcsaSOpMSjs+5T8OPrb4SzKTIa/oI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=MTmTlvW2; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MTmTlvW2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715510606; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=oxrgodSSTuZswJnNY6k+AyI3wOxNGvPqyHgv829oWBs=; b=MTmTlvW2txlpc8nQCGdMXtpYUsEiRTbAXx3m1ZLDX+Nbowdjd6+JhsmMLvzgFRiJ3Wl48u MwGehcJ6CZzs0p77p1OtIZQUoCjdeS64/WKhS9Tf5mBn+ZMSKyLaXCulNMTxmqk0vswsZC +gFgQV5WjWy4ygIZpMJc2+WHOVC3b4M= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-303-ckBUExiOMliF3DcwR5UIXw-1; Sun, 12 May 2024 06:43:22 -0400 X-MC-Unique: ckBUExiOMliF3DcwR5UIXw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CE33F8030A4; Sun, 12 May 2024 10:43:21 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.31]) by smtp.corp.redhat.com (Postfix) with SMTP id 0DEA7492BC6; Sun, 12 May 2024 10:43:18 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sun, 12 May 2024 12:41:55 +0200 (CEST) Date: Sun, 12 May 2024 12:41:52 +0200 From: Oleg Nesterov To: "Paul E. McKenney" Cc: "Uladzislau Rezki (Sony)" , RCU , Neeraj upadhyay , Boqun Feng , Hillf Danton , Joel Fernandes , LKML , Oleksiy Avramchenko , Frederic Weisbecker , Peter Zijlstra Subject: Re: [PATCH 25/48] rcu: Mark writes to rcu_sync ->gp_count field Message-ID: <20240512104151.GA7541@redhat.com> References: <20240507093530.3043-1-urezki@gmail.com> <20240507093530.3043-26-urezki@gmail.com> <4c9e89b5-c981-4809-8bc2-247563ce04e9@paulmck-laptop> <20240510131849.GB24764@redhat.com> <20240510135057.GC24764@redhat.com> <474ae55c-fe9e-4668-8f9b-23f819c76d10@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <474ae55c-fe9e-4668-8f9b-23f819c76d10@paulmck-laptop> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Sorry for another delay... On 05/10, Paul E. McKenney wrote: > > On Fri, May 10, 2024 at 03:50:57PM +0200, Oleg Nesterov wrote: > > > > I can only find the strnstr(buf, "rcu") checks in skip_report(), > > but they only cover the KCSAN_REPORT_VALUE_CHANGE_ONLY case... > > Huh, new one on me! When I run KCSAN, I set CONFIG_KCSAN_STRICT=y, > which implies CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n, which should > prevent skip_report() from even being invoked. > > Which suggests that in the rest of the kernel, including "rcu_" > in your function name gets you stricter KCSAN checking. ;-) Yes. And that is why I was very confused. I misinterpreted the "stricter data-race rules used in RCU code" as if there must be more "rcu-only" hacks in the kernel/kcsan/ code which I can't find ;) Oleg.