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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 9C409C433ED for ; Sat, 17 Apr 2021 03:46:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 786B3611AB for ; Sat, 17 Apr 2021 03:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235589AbhDQDqq (ORCPT ); Fri, 16 Apr 2021 23:46:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235569AbhDQDqn (ORCPT ); Fri, 16 Apr 2021 23:46:43 -0400 Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D03F3C061574; Fri, 16 Apr 2021 20:46:17 -0700 (PDT) Received: by mail-lf1-x131.google.com with SMTP id r128so20822339lff.4; Fri, 16 Apr 2021 20:46:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3UKS3by2sRC26TiZQut2iFygOIbUq4FQcjO23uuSGpw=; b=cls8otFlkhE4SEaa1P7uPvIpmnhty0IKil4+wO18Wb3HP4JSIk5kxDkvEJPnRKy7pB 9KdbfHzVU5I0rFzdaJqhBf7e0PnxMWBWfgqJh2xPoiUc5/SAw2gHCJNra+LZjlVAfCeL a4+W2wzqYvfXX7Zp/Ff0I/d+z4w+FxvQlsQUoxKwG5KnPPoyTM7zgjCF10UJ39Rx8/uV ey9G35g+PS6VGEISAscESGPXcBZhmP/0+KEROh5cNRfsvvqt61Kx0gnS5f/L4/CH1Nmv cW1v2fLv4KlGGxBiLxwup/YCD/uyHAGlNnsGoYkzh+ob/lBXlJ2rSgcHgNLCObjuM/Id PtRQ== 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=3UKS3by2sRC26TiZQut2iFygOIbUq4FQcjO23uuSGpw=; b=prNf8QLgsi19uECxgw0WEZh1kmfAC4fT9aHUiugXdzYN50fnmzHsNXXHIzbAlzV3yw p1SWYI1FJz426NylV8WOmLibYcxM3XAAlptRFtRz0EkSW2IgNqDQOQD5DcF+1OWRibGO Rsut6Va57mRa3jyA+FhdmW4fk5bSyMxB2CiUQfx4OLZU+Z/MEWb8ssqbO2jPitTYwtF/ 1y3kB2p4N0ymeo0zFCBDvGSG52INo0VeOYp4gw4+R6tlu6Dab4VYPOyMO22JlKECWlHx SNVaBY+AxFDX28x1+mBdXEEFm5i6sD9vGjxLxFkoj+Y0nTvTg9yz2Z5ZtEjIGylDoNCc dKTA== X-Gm-Message-State: AOAM531of0oTmfMHLcUumotnZpubiLut7JEqzWM1pMiOnz4p7aDvQe16 mQsHFR+7cFvu5ys8jkFohpsJoZtwPvWJPksl6KWhqHK3 X-Google-Smtp-Source: ABdhPJylmVjCb+XDl1LDXBqn+2vSU7ZrEApcRGAMpVxUiEJ09xoj8yJS6fxQQ5/1vZx+2J4dW8xmok9ZUIvph85cKVs= X-Received: by 2002:a05:6512:21a5:: with SMTP id c5mr5199445lft.534.1618631176390; Fri, 16 Apr 2021 20:46:16 -0700 (PDT) MIME-Version: 1.0 References: <20210417033224.8063-1-alexei.starovoitov@gmail.com> <20210417033224.8063-12-alexei.starovoitov@gmail.com> In-Reply-To: From: Alexei Starovoitov Date: Fri, 16 Apr 2021 20:46:05 -0700 Message-ID: Subject: Re: [PATCH bpf-next 11/15] bpf: Add bpf_sys_close() helper. To: Al Viro Cc: "David S. Miller" , Daniel Borkmann , Andrii Nakryiko , Network Development , bpf , Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Apr 16, 2021 at 8:42 PM Al Viro wrote: > > On Fri, Apr 16, 2021 at 08:32:20PM -0700, Alexei Starovoitov wrote: > > From: Alexei Starovoitov > > > > Add bpf_sys_close() helper to be used by the syscall/loader program to close > > intermediate FDs and other cleanup. > > Conditional NAK. In a lot of contexts close_fd() is very much unsafe. > In particular, anything that might call it between fdget() and fdput() > is Right Fucking Out(tm). > In which contexts can that thing be executed? user context only. It's not for all of bpf _obviously_.