Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756235Ab3HZIXV (ORCPT ); Mon, 26 Aug 2013 04:23:21 -0400 Received: from mx-out.ocsa-data.net ([194.36.166.37]:54703 "EHLO mx-out.ocsa-data.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755699Ab3HZIXT (ORCPT ); Mon, 26 Aug 2013 04:23:19 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Mon, 26 Aug 2013 10:23:12 +0200 From: Yann Droneaud To: Paolo Bonzini Cc: Alexander Graf , Gleb Natapov , Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Paolo Bonzini Subject: Re: [PATCH 2/2] ppc: kvm: use =?UTF-8?Q?anon=5Finode=5Fgetfd=28?= =?UTF-8?Q?=29=20with=20O=5FCLOEXEC=20flag?= Organization: OPTEYA In-Reply-To: <521B0622.9090208@redhat.com> References: <3557EF65-4327-4DAE-999A-B0EE13C433F5@suse.de> <521B0622.9090208@redhat.com> Message-ID: <156342996ba92cb5f49519b0c2e9d6ac@meuh.org> User-Agent: Roundcube Webmail/0.9.2 X-abuse-contact: abuse@ocsa-data.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 43 Le 26.08.2013 09:39, Paolo Bonzini a écrit : > Il 25/08/2013 17:04, Alexander Graf ha scritto: >> On 24.08.2013, at 21:14, Yann Droneaud wrote: >> >>> >>> This patch set O_CLOEXEC flag on all file descriptors created >>> with anon_inode_getfd() to not leak file descriptors across exec(). >>> >>> Signed-off-by: Yann Droneaud >>> Link: >>> http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com >> >> Reviewed-by: Alexander Graf >> >> Would it make sense to simply inherit the O_CLOEXEC flag from the >> parent kvm fd instead? That would give user space the power to keep >> fds across exec() if it wants to. > > Does it make sense to use non-O_CLOEXEC file descriptors with KVM at > all? Besides fork() not being supported by KVM, as described in > Documentation/virtual/kvm/api.txt, the VMAs of the parent process go > away as soon as you exec(). I'm not sure how you can use the inherited > file descriptor in a sensible way after exec(). > Sounds a lot like InfiniBand subsystem behavor: IB file descriptors are of no use accross exec() since memory mappings tied to those fds won't be available in the new process: https://lkml.org/lkml/2013/7/8/380 http://mid.gmane.org/f58540dc64fec1ac0e496dfcd3cc1af7@meuh.org Regards. -- Yann Droneaud OPTEYA -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/