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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 620FCC43381 for ; Sat, 30 Mar 2019 16:39:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31793218D0 for ; Sat, 30 Mar 2019 16:39:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=brauner.io header.i=@brauner.io header.b="SBAbLJ+y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730755AbfC3QjB (ORCPT ); Sat, 30 Mar 2019 12:39:01 -0400 Received: from mail-ed1-f65.google.com ([209.85.208.65]:45902 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730395AbfC3Qi7 (ORCPT ); Sat, 30 Mar 2019 12:38:59 -0400 Received: by mail-ed1-f65.google.com with SMTP id m16so4560071edd.12 for ; Sat, 30 Mar 2019 09:38:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brauner.io; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=jjm0qai9ZYPiT6TdWCxaI36M0QNMMCcOH+KsLm1g4yk=; b=SBAbLJ+yrT3ryIK8UHLD8e8YOy5e0RUB5qoIpTlBgTCKRnKhaWgXL1opeOGSFccP1+ Rr+c5AGBH96NUOy+P5hPzupqRZwaBGNsPgk6Gemwv1DeT7woLhWA0211e0SyjGBunmkv B/LcHtd96AYr1f6m06qZau9xqoc45UoeqNJXrGWSc4cGFsNZCOLtdIVSHTMqNo0IlWLf MZrBcH6oFRTw2XgEA0Icu5Kp7f+v88CaXuKK4rKNvr2wI8hFiasqtIW6OIJaKD2t/MNd VqkMLvPNkrTb7JhylLzuHWXb9zFFQOLaqfYkH3FewhL0ID/zUpmTScMvrauYoZ5BznXB L2Tg== 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=jjm0qai9ZYPiT6TdWCxaI36M0QNMMCcOH+KsLm1g4yk=; b=Ex/11anN9l2ozGn/BCiR8tIQ1Ihx7bm/hPQCCpdOzwpPdPVhQ5c3XOrY+seqK3feOf LBcovnYleojLcKKshJzgTk5289hhvvNa8JawIcPYnPy5sO/lDdbGAgbDjcsOU24Ib7Qk c0nm7nMVcfxZoW+6UQ9NY/rfjzFjMh0IDZNZO+H+oHiRYiWadyCkgFRQxqDGG4uIVF03 Kr1kGlameHqAIYyLItZUC9bn1yaP7M/O3FqXg759ponAfCYt9JHeiiNlIrDgWfWq44lZ 9efHSLZo/66Og53bSa6LWmzcoohFeFQHSsWiOTb4kz5w8VFOpBalWjoOPbdzBv//AVN4 wnxA== X-Gm-Message-State: APjAAAW4zqa529xhdGJ18gvxO/x4gZ/O/2y5dwHdCq3q8wx6Fj+3EjUu Tu5x3VV6HaUke2dmXHJonqgYFqR69Pc= X-Google-Smtp-Source: APXvYqwjwbGrlXkFfHKuLi9tVi+NPei06uIdq8rzwFfzs86tuXCrs4S8TxJXuTGg+WQUNI0MlV81qw== X-Received: by 2002:a50:97d0:: with SMTP id f16mr34880013edb.287.1553963937408; Sat, 30 Mar 2019 09:38:57 -0700 (PDT) Received: from brauner.io ([2a02:8109:b6bf:d24a:b136:35b0:7c8c:280a]) by smtp.gmail.com with ESMTPSA id z35sm1613912edd.81.2019.03.30.09.38.56 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Sat, 30 Mar 2019 09:38:56 -0700 (PDT) Date: Sat, 30 Mar 2019 17:38:55 +0100 From: Christian Brauner To: Daniel Colascione Cc: Linus Torvalds , Jann Horn , Andrew Lutomirski , David Howells , "Serge E. Hallyn" , Linux API , Linux List Kernel Mailing , Arnd Bergmann , "Eric W. Biederman" , Konstantin Khlebnikov , Kees Cook , Alexey Dobriyan , Thomas Gleixner , Michael Kerrisk-manpages , Jonathan Kowalski , "Dmitry V. Levin" , Andrew Morton , Oleg Nesterov , Nagarathnam Muthusamy , Aleksa Sarai , Al Viro , Joel Fernandes Subject: Re: [PATCH v2 0/5] pid: add pidfd_open() Message-ID: <20190330163854.t67m2h6m3hmshqtg@brauner.io> References: <20190329155425.26059-1-christian@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 30, 2019 at 09:34:02AM -0700, Daniel Colascione wrote: > On Sat, Mar 30, 2019 at 9:24 AM Linus Torvalds > wrote: > > > > On Sat, Mar 30, 2019 at 9:19 AM Christian Brauner wrote: > > > > > > From pure API perspective that's all I care about: independence of procfs. > > > Once we have pidfd_open() we can cleanly signal threads etc. > > > > But "independence from procfs" means that you damn well don't then do > > "oh, now I have a pidfd, I want to turn it into a /proc fd and then > > munge around there". > > > > So I'm literally saying that it had better really *be* independent > > from /proc. It is the standalone version, but it's most definitely > > also the version that doesn't then give you secret access to /proc. > > Just to be clear, I'm not proposing granting secret access to procfs, > and as far as I can see, nobody else is either. We've been talking > about making it easier to avoid races when you happen to want a pidfd > and a procfs fd that point to the same process, not granting access > that you didn't have before. If you'd rather not connect procfs and > pidfds, we can take this functionality off the table. This is dead! Nothing like this will make it through this tree. I have no intention of endangering pidfd_send_signal(). Christian From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Brauner Subject: Re: [PATCH v2 0/5] pid: add pidfd_open() Date: Sat, 30 Mar 2019 17:38:55 +0100 Message-ID: <20190330163854.t67m2h6m3hmshqtg@brauner.io> References: <20190329155425.26059-1-christian@brauner.io> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Daniel Colascione Cc: Linus Torvalds , Jann Horn , Andrew Lutomirski , David Howells , "Serge E. Hallyn" , Linux API , Linux List Kernel Mailing , Arnd Bergmann , "Eric W. Biederman" , Konstantin Khlebnikov , Kees Cook , Alexey Dobriyan , Thomas Gleixner , Michael Kerrisk-manpages , Jonathan Kowalski , "Dmitry V. Levin" , Andrew Morton , Oleg Nesterov , Nagarathnam List-Id: linux-api@vger.kernel.org On Sat, Mar 30, 2019 at 09:34:02AM -0700, Daniel Colascione wrote: > On Sat, Mar 30, 2019 at 9:24 AM Linus Torvalds > wrote: > > > > On Sat, Mar 30, 2019 at 9:19 AM Christian Brauner wrote: > > > > > > From pure API perspective that's all I care about: independence of procfs. > > > Once we have pidfd_open() we can cleanly signal threads etc. > > > > But "independence from procfs" means that you damn well don't then do > > "oh, now I have a pidfd, I want to turn it into a /proc fd and then > > munge around there". > > > > So I'm literally saying that it had better really *be* independent > > from /proc. It is the standalone version, but it's most definitely > > also the version that doesn't then give you secret access to /proc. > > Just to be clear, I'm not proposing granting secret access to procfs, > and as far as I can see, nobody else is either. We've been talking > about making it easier to avoid races when you happen to want a pidfd > and a procfs fd that point to the same process, not granting access > that you didn't have before. If you'd rather not connect procfs and > pidfds, we can take this functionality off the table. This is dead! Nothing like this will make it through this tree. I have no intention of endangering pidfd_send_signal(). Christian