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 30E66C433E0 for ; Thu, 4 Jun 2020 00:14:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08CBF2067B for ; Thu, 4 Jun 2020 00:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591229643; bh=wJt/E3KOzAbfjnU6Afr8qP51B0SkXgeMthZGOmvjbFk=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=H1coTPlwGZ9tXXJ7e9l7e2/w6EH/hFVTKgd0TmJr5Qrp5DymV2KcSU2H4RI2NGApj vZpWUmgEM7+yQrqEUgDbHVXQTCYbCRkrymio+Cvd6V4+R8MR8yKtmY0/h3z0sRyR+w LxWnoSudC84yAOSawJeRb331XNAbzUyoM3xgnbjw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726363AbgFDAN7 (ORCPT ); Wed, 3 Jun 2020 20:13:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbgFDAN7 (ORCPT ); Wed, 3 Jun 2020 20:13:59 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 704EDC08C5C0 for ; Wed, 3 Jun 2020 17:13:57 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id 9so5014787ljc.8 for ; Wed, 03 Jun 2020 17:13:57 -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=rWe2Q0RVzrp4gR0EET85HSpI5Y5evJHsyhPkQ14mL0k=; b=bt0TGPg3m1SCTLBdHymXFLfl3E3L3r+udH7rn8D+EBhHjSsJezRKQc5I44quK2Ep95 n7O9rGE+x0OuzzxK9JDFKVEZNlNil/zWzB2OtsPvSkq3h3Byx+1A/PbyAJD8T+ACtvtF KVePdWwwaM3XuFRkXqkGtRQjsVdhDo42Nx8Z8= 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=rWe2Q0RVzrp4gR0EET85HSpI5Y5evJHsyhPkQ14mL0k=; b=dpYFUvVOZ6i6sormjEfGyMub2aFCncsxBanIsQV7gdGgpcUpGjgC+IVwhkdcw0aXS6 Ra2G7HjdMgMUbsDN3lu6GWb4kZszWDzCqgN+mSzBKHZy2CjWYztxfFZEo0dVchH2rCDb 8YXf8s8oyrocFtI0CribaUbh3Hljw2r1GnkfQtVDl7SA2HK7t8fNlTnuG2z8OJXLFjDr y1pzTuf+ummKPT+htqOHE3O4IXIaQGn0Sr2tRourFoVczsOaBQcYtBDxbdHQpo6gYOe4 PCU31FHd0n7z1C6h9wRovsHM77zHBndIaUgd7Qu9EVpZk3k/WvZShN1Vl9g1EwGPuriF eFWQ== X-Gm-Message-State: AOAM532EX6RV7rey9Pqt1DRmKvpE6v4yvmkGjCqBkJwJuMT7+aaQW9Vk Oy2cKrggXboE1HJqB1LD20+6QDMHvUw= X-Google-Smtp-Source: ABdhPJxXa9Qk7TRUxTwZ/s38UMCBnlHvqdVeoS9h2NQwuGoobBvFH051QJZzr54DUD4orE7szbKJbA== X-Received: by 2002:a2e:a17a:: with SMTP id u26mr742539ljl.235.1591229635022; Wed, 03 Jun 2020 17:13:55 -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 v23sm210583ljg.122.2020.06.03.17.13.52 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 03 Jun 2020 17:13:52 -0700 (PDT) Received: by mail-lj1-f169.google.com with SMTP id z9so5000213ljh.13 for ; Wed, 03 Jun 2020 17:13:52 -0700 (PDT) X-Received: by 2002:a2e:7e0a:: with SMTP id z10mr790807ljc.314.1591229631853; Wed, 03 Jun 2020 17:13:51 -0700 (PDT) MIME-Version: 1.0 References: <20200602204219.186620-1-christian.brauner@ubuntu.com> <20200602233355.zdwcfow3ff4o2dol@wittgenstein> <20200603232410.i3opsbmepv5ktsjq@wittgenstein> In-Reply-To: <20200603232410.i3opsbmepv5ktsjq@wittgenstein> From: Linus Torvalds Date: Wed, 3 Jun 2020 17:13:36 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v5 0/3] close_range() To: Christian Brauner Cc: Linux Kernel Mailing List , Kyle Evans , Victor Stinner , Al Viro , linux-fsdevel , Linux API , Florian Weimer , Jann Horn , Oleg Nesterov , Arnd Bergmann , Shuah Khan , David Howells , "Dmitry V. Levin" Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jun 3, 2020 at 4:24 PM Christian Brauner wrote: > > Ok, here's what I have. Does the below look somewhat sane? Probably. Needs lots of testing. But this one looks wrong: > +int __close_range(unsigned fd, unsigned max_fd, unsigned int flags) > { > + if ((max_fd + 1) >= cur_max) > + max_unshare_fds = fd; A normal value for "close everything starting at X" would have a max_fd value of ~0. So "max_fd+1" would overflow to 0, and then this would never trigger. Other than that it looks what what I imagine my feverdreams were about. Linus