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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 506D6C433DF for ; Sun, 24 May 2020 08:11:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28AC92073B for ; Sun, 24 May 2020 08:11:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bOftp8Lu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728502AbgEXILh (ORCPT ); Sun, 24 May 2020 04:11:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726331AbgEXILe (ORCPT ); Sun, 24 May 2020 04:11:34 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8B95C061A0E for ; Sun, 24 May 2020 01:11:32 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id t8so4974661pju.3 for ; Sun, 24 May 2020 01:11:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3HmigCjALU51rYyyBGLBKoAkAQrHtdUuG74Co9AoT2k=; b=bOftp8LuT45vtlcgLJtjpOry5/pv7Z9eYAW/kDJ4hv9mL1zH6kBeG9rGtJO/SUkxKD AhjB9/hQYWO2IvXPAYBQveWvNSMAV7Bi9GyK1m3yDD8ZY11At5npkesASAhZRT5EyiAi 2ZwJwciZQSZM3eastyOWAcDaCExSo1HNsXVpgDfakIz1I0hnBc3jXebsZnvqj2FINutY 6un9yGg+cRgpaQOhel7BuhW3f0DmtTJHBaOAca1Rs0jhlVQ1Kkwa65ZozwBS4Y/f8iyb nLw11kV+l7FTvOV2lr/HLGPwbUF/HgpexqTQMqFBQbpMFXMaqeZTemVIVg2ks1U1RLrl hbLQ== 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:user-agent; bh=3HmigCjALU51rYyyBGLBKoAkAQrHtdUuG74Co9AoT2k=; b=oybLdZtG72QGdh0B6K0yFkWKDm1abTMuhtVuE3JDo999tiEaDcJ3ZhPPrZeCc7NW41 kqhiTWI0kpwHyHxROA1gAA6j9kKuvRTO0NJ/OMQ+9jzxnWyOLna57swBrOHXdbb1x+XD xWzcx6fX6AN45fk/VBQAWnjSd3GPB0iuISXVQFQXah4mNQCCV6krp1mJmKMsA8EgcJG9 cPAmvNJocga+fi1zXdO7qL179FyTaIMFf9DuX3hYoT+A094cDqJozwr5iEUw9yoNFZV+ AkMt/QB1dnxtJirke2q9wObmd79pE+UxmIdBOSSXxRmGk+RM7Vb4/KPf4Bay3IYSmDCR HeQA== X-Gm-Message-State: AOAM5316TwkFP6qxeRkNQACKsYQkzbCtM2rMaqcp/MtJIqsuK5UogV34 1kHxhNtjmcU9MQQT8dJozjE= X-Google-Smtp-Source: ABdhPJxZfKElYBNI4glOcgWKrPyJxs5PiTsJpx+QFxqGsjUJty7CXioEENo2hycw40fd49jQga2ajg== X-Received: by 2002:a17:90a:8989:: with SMTP id v9mr14838930pjn.180.1590307892183; Sun, 24 May 2020 01:11:32 -0700 (PDT) Received: from workstation-LAP.localdomain ([103.87.57.241]) by smtp.gmail.com with ESMTPSA id p190sm10520227pfp.207.2020.05.24.01.11.23 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 24 May 2020 01:11:31 -0700 (PDT) Date: Sun, 24 May 2020 13:41:17 +0530 From: Amol Grover To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , James Morris , Thomas Gleixner , Jann Horn , David Howells , Shakeel Butt , "Eric W . Biederman" , Andrew Morton , Paul Moore , Eric Paris Cc: linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, linux-audit@redhat.com, Joel Fernandes , Madhuparna Bhowmik , "Paul E . McKenney" Subject: Re: [PATCH 1/3 RESEND] sched: Remove __rcu annotation from cred pointer Message-ID: <20200524081117.GA29@workstation-LAP.localdomain> References: <20200402055640.6677-1-frextrite@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200402055640.6677-1-frextrite@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 02, 2020 at 11:26:38AM +0530, Amol Grover wrote: > task_struct::cred (subjective credentials) is *always* used > task-synchronously, hence, does not require RCU semantics. > > task_struct::real_cred (objective credentials) can be used in > RCU context and its __rcu annotation is retained. > > However, task_struct::cred and task_struct::real_cred *may* > point to the same object, hence, the object pointed to by > task_struct::cred *may* have RCU delayed freeing. > > Suggested-by: Jann Horn > Co-developed-by: Joel Fernandes (Google) > Signed-off-by: Joel Fernandes (Google) > Signed-off-by: Amol Grover Hello everyone, Could you please go through patches 1/3 and 2/3 and if deemed OK, give your acks. I sent the original patch in beginning of February (~4 months back) and resent the patches again in beginning of April due to lack of traffic. Paul Moore was kind enough to ack twice - the 3/3 and its resend patch. However these 2 patches still remain. I'd really appreciate if someone reviewed them. Thanks Amol