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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 11E94C2BA16 for ; Fri, 3 Apr 2020 20:59:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB2DA206F5 for ; Fri, 3 Apr 2020 20:59:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585947570; bh=IC6F06iWYBrCuu+GEo9Doyj2eWJtaWfT1eP1IYhiCok=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=0fLL+sH/Ka+33k7RQ+pcA7wOzfq+iCqiud3EjGAu9EAHu/D7+ypBA6yWVNZNm1qJL bLYavDo5YIjxbMALZ0qcpkbfsHGzARWyELQfEN1IcGPrzGSFfMmcJiV8oSDw6S1ZR5 caJEjj1iMxYyEef5U7LdLz4dNl++xmpvJBYa9b7M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728563AbgDCU7a (ORCPT ); Fri, 3 Apr 2020 16:59:30 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:41867 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727842AbgDCU73 (ORCPT ); Fri, 3 Apr 2020 16:59:29 -0400 Received: by mail-lf1-f65.google.com with SMTP id z23so6950213lfh.8 for ; Fri, 03 Apr 2020 13:59:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1CPxyFZxPc0YcfVvPFYxLsM93XxYFQGYmYW5SAM+S+8=; b=PwTMldcFXCyjXBv90GqkWmt5NnXcBLXrRaGeI063rXMArUMJ8dlr+c5UyGSB4Quc9t BgTDfblec08zcfAN5Izm0O6uJWxWcktbZckqqwVwUBAH/xDWG52bD6nh8dEVYqKHDV3i UXOdzpEza/hEDwO9OzlWJHZkEgL2qyxw5qTT4= 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=1CPxyFZxPc0YcfVvPFYxLsM93XxYFQGYmYW5SAM+S+8=; b=mhMabswsXsbAblfZRyAOot9jVfX+jaKIJdZd8zHbHLvfD2CefmBGqujk2OjTlWHbG0 QqqfASH7dDgonzxiP4zc7thSA0sF9V/AOD+E+3ksgd/8aFPRuEaemHJfms9dBzbfP3Pt sYUMZC5hJQLhIkVXUGgisBfSl0bvooN49ueELUP8eGljLiqe2kwG4NWy8ACvFg0Ph+mV zsysjQRLzYWagrlghjlyJtXiHa/XC7gQ5AQbHRTgfTQXqhNtC1unC9DSOoJ32wx61vdE h5l20s86ISYuOsmROUIoaK7Hh1Ox7GKCHrIdKsQnsGr+kfWzFUuMWlKlS3hsxBABsY+5 aXLQ== X-Gm-Message-State: AGi0Pubi7OHXQyHeuJmhkI9Y+P+twEuHaJUpCnGuxJ/8zySxkEgNpT1d siknZ4S59QXmwtNpdM860TgpkqS8SOg= X-Google-Smtp-Source: APiQypKcsOnVUe5yThB8Qz4jC0LhRYfYB4vyYD1Ix+SQVuM1Ja0ZfHHnh0AdaODcCjCe2pXf0hP3Aw== X-Received: by 2002:ac2:4c9a:: with SMTP id d26mr5283981lfl.112.1585947566383; Fri, 03 Apr 2020 13:59:26 -0700 (PDT) Received: from mail-lj1-f169.google.com (mail-lj1-f169.google.com. [209.85.208.169]) by smtp.gmail.com with ESMTPSA id k4sm6461112lfo.47.2020.04.03.13.59.24 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 03 Apr 2020 13:59:25 -0700 (PDT) Received: by mail-lj1-f169.google.com with SMTP id f20so8434398ljm.0 for ; Fri, 03 Apr 2020 13:59:24 -0700 (PDT) X-Received: by 2002:a2e:8911:: with SMTP id d17mr6047340lji.16.1585947564510; Fri, 03 Apr 2020 13:59:24 -0700 (PDT) MIME-Version: 1.0 References: <87blobnq02.fsf@x220.int.ebiederm.org> <87lfnda3w3.fsf@x220.int.ebiederm.org> <328f5ad3-f8b3-09b9-f2f7-b6dae0137542@redhat.com> In-Reply-To: <328f5ad3-f8b3-09b9-f2f7-b6dae0137542@redhat.com> From: Linus Torvalds Date: Fri, 3 Apr 2020 13:59:08 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] Please pull proc and exec work for 5.7-rc1 To: Waiman Long Cc: "Eric W. Biederman" , Ingo Molnar , Will Deacon , Bernd Edlinger , Linux Kernel Mailing List , Alexey Gladkov Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 3, 2020 at 1:41 PM Waiman Long wrote: > > Another alternative is to add new functions like down_read_unfair() that > perform unfair read locking for its callers. That will require less code > change, but the calling functions have to make the right choice. I'd prefer the static choice model - and I'd hide this in some "task_cred_read_lock()" function anyway rather than have the users do "mutex_lock_killable(&task->signal->cred_guard_mutex)" like they do now. How nasty would it be to add the "upgrade" op? I took a quick look, but that just made me go "Waiman would know" ;) Linus