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 6A420C433DF for ; Thu, 4 Jun 2020 00:21:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 419C520772 for ; Thu, 4 Jun 2020 00:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591230077; bh=wJt/E3KOzAbfjnU6Afr8qP51B0SkXgeMthZGOmvjbFk=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=WVGOv/G2TKIH1hx048sh7LV5OGm8Pby8zdFFh3Y33ed7X6PfM/HNCI8AAj2npUuVz wRlfBlQupuaUi/pC2DjiegxRscSuNUVHGteZ+h4XjmuVoEykan+VFjkbB0jtpnWFyu ZDpHQT8ScwOyKfQFkwkS2xZhs94/sARqs2GCsoR8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726385AbgFDAVQ (ORCPT ); Wed, 3 Jun 2020 20:21:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725946AbgFDAVQ (ORCPT ); Wed, 3 Jun 2020 20:21:16 -0400 Received: from mail-ed1-x544.google.com (mail-ed1-x544.google.com [IPv6:2a00:1450:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36C5CC08C5C0 for ; Wed, 3 Jun 2020 17:21:15 -0700 (PDT) Received: by mail-ed1-x544.google.com with SMTP id w7so3247819edt.1 for ; Wed, 03 Jun 2020 17:21:15 -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=r9AKBeUMBrgl4HM9bfPFrigzPJpaeiWNJ5gic/QPPQ+0US53TYH/c89duhHwaUkjJD PlcMmeDQ8Mqz+OQVQaDxrJXjOfKs/s/BQSaQVCGhXvEDErPSZymj+1885ysmhyZqcR5q ul5XOYzrhrYDTb39sQ9sd13Fx0KhSrfQCGbBlJmZIUNvd0HjzgjaGU1e4zTwTUy6u7BB wAcb3aP17N6fLbhclAAqX46beHKH3CCfvg3Kn2b2EUWohF4Y7zljVqG6rDBfxJ2SxC8M L4eAtdoErrbdE9gtLB4k57FyLQUqQypdFF/mr8y9W5XE3jISzDJ1TfDK5nZ1rThpYZFL WY7Q== X-Gm-Message-State: AOAM531qlZLeWQD4YcxYr1hz2VIU4xI4bOOXUMRrKhvRrFWpJyRY0qRY rJuLMcE5pbVgr2nuNx8DEzHjd6N5d/I= X-Google-Smtp-Source: ABdhPJzksin3PkN75zeKyhMNo33PMeVgncI/v29uyWwQpWCB0Q8FKfZoZn2k0kqz8VUH4VVRhgxsLg== X-Received: by 2002:a05:6402:19a9:: with SMTP id o9mr1813808edz.205.1591230073343; Wed, 03 Jun 2020 17:21:13 -0700 (PDT) Received: from mail-wr1-f50.google.com (mail-wr1-f50.google.com. [209.85.221.50]) by smtp.gmail.com with ESMTPSA id k9sm652110edl.83.2020.06.03.17.21.13 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 03 Jun 2020 17:21:13 -0700 (PDT) Received: by mail-wr1-f50.google.com with SMTP id x13so4205598wrv.4 for ; Wed, 03 Jun 2020 17:21:13 -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-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@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