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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 7F29BECE563 for ; Mon, 17 Sep 2018 15:49:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C7C720883 for ; Mon, 17 Sep 2018 15:49:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C7C720883 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728563AbeIQVRg (ORCPT ); Mon, 17 Sep 2018 17:17:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48992 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727691AbeIQVRf (ORCPT ); Mon, 17 Sep 2018 17:17:35 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0281C5F7AC; Mon, 17 Sep 2018 15:49:41 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.34.27.30]) by smtp.corp.redhat.com (Postfix) with SMTP id 9B74F7EB8F; Mon, 17 Sep 2018 15:49:39 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 17 Sep 2018 17:49:40 +0200 (CEST) Date: Mon, 17 Sep 2018 17:49:38 +0200 From: Oleg Nesterov To: "Eric W. Biederman" Cc: Jeff Layton , viro@zeniv.linux.org.uk, berrange@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 1/3] exec: Move unshare_files down to avoid locks being dropped on exec. Message-ID: <20180917154938.GC25173@redhat.com> References: <20180914105310.6454-1-jlayton@kernel.org> <87a7ohs5ow.fsf@xmission.com> <874leps5n9.fsf_-_@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <874leps5n9.fsf_-_@xmission.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 17 Sep 2018 15:49:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/16, Eric W. Biederman wrote: > > @@ -1291,6 +1292,12 @@ int flush_old_exec(struct linux_binprm * bprm) > flush_thread(); > current->personality &= ~bprm->per_clear; > > + retval = unshare_files(&displaced); I was going to sugget basically the same changes, please feel free to add my reviewed-by to 1-3. Just for record. If we should really worry about unshare_files() failure after de_thread() (imo we shouldn't), we can do another change: __do_execve_file: unshare_fd(CLONE_FILES, &bprm->unshared_copy); ... flush_old_exec: de_thread(); if (bprm->unshared_copy) { // now that we killed sub-threads recheck if (current->files->count > 1) { put_files_struct(current->files); current->files = bprm->unshared_copy; } else { put_files_struct(bprm->unshared_copy); } } but again, I think your series is fine. Oleg.