From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 5B1C6384F01A for ; Wed, 25 May 2022 12:24:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 5B1C6384F01A Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-624-mV0rL42EP-emfLKTi2cmYg-1; Wed, 25 May 2022 08:24:46 -0400 X-MC-Unique: mV0rL42EP-emfLKTi2cmYg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AFAD81C01B24; Wed, 25 May 2022 12:24:45 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.94]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 105F840CF8EF; Wed, 25 May 2022 12:24:43 +0000 (UTC) From: Florian Weimer To: Christian Brauner Cc: Adhemerval Zanella , libc-alpha@sourceware.org, Alexey Izbyshev , Carlos O'Donell , Andrei Vagin Subject: Re: [PATCH v4 0/3] Linux: Fix posix_spawn when user with time namespaces References: <20220510191155.1998575-1-adhemerval.zanella@linaro.org> <877d6tb3hl.fsf@oldenburg.str.redhat.com> <20220511092119.ke4zlm2dkazasmva@wittgenstein> Date: Wed, 25 May 2022 14:24:42 +0200 In-Reply-To: <20220511092119.ke4zlm2dkazasmva@wittgenstein> (Christian Brauner's message of "Wed, 11 May 2022 11:21:19 +0200") Message-ID: <87h75dyf3p.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 May 2022 12:24:48 -0000 * Christian Brauner: > On Tue, May 10, 2022 at 09:18:46PM +0200, Florian Weimer wrote: >> * Adhemerval Zanella: >> >> > The patchset adds some support to tests the fallback code to >> > use only use CLONE_VFORK. It uses unshare directly because >> > it simpler than add container support. >> > >> > Adhemerval Zanella (3): >> > linux: Add CLONE_NEWTIME from Linux 5.6 to bits/sched.h >> > support: Add support_enter_time_namespace >> > linux: Add fallback for clone failure on posix_spawn (BZ #29115) >> >> Christan, how likely is it that we'd get another time namespace variant >> that would only become effective after execve (when the DSO is remapped >> anyway)? > > Not unlikely if it helps you avoid a lot of complexity. I will need some > time to track down Andrei and others to discuss though. Any progress with that? (I hope I guessed the right Andrei.) Breaking vfork is really a bit of a hassle for us, and the workaround code is quite non-trivial and will have to implemented across many projects (not just glibc). An unshare request that takes effect on execve only would really help. Thanks, Florian