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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 3DF4D3858D3C for ; Tue, 3 May 2022 20:17:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3DF4D3858D3C Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-627-J-UnBO39N2GlcLdrc4mx2w-1; Tue, 03 May 2022 16:16:38 -0400 X-MC-Unique: J-UnBO39N2GlcLdrc4mx2w-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5E05B8041AF; Tue, 3 May 2022 20:16:37 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.113]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 85DF0550849; Tue, 3 May 2022 20:16:36 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella via Libc-alpha Subject: Re: [PATCH 1/5] Linux: Implement a useful version of _startup_fatal References: <7a6a51b346a81484046ba392a9854a88568a92aa.1651518694.git.fweimer@redhat.com> <87ilqn4spx.fsf@oldenburg.str.redhat.com> <877d734qne.fsf@oldenburg.str.redhat.com> <87bkwfxkhg.fsf@oldenburg.str.redhat.com> <87levifvwm.fsf@oldenburg.str.redhat.com> <87h766ftx0.fsf@oldenburg.str.redhat.com> <87czguftaw.fsf@oldenburg.str.redhat.com> <7d39fd76-9802-03ca-0a24-bff8223eb53e@linaro.org> Date: Tue, 03 May 2022 22:16:34 +0200 In-Reply-To: <7d39fd76-9802-03ca-0a24-bff8223eb53e@linaro.org> (Adhemerval Zanella via Libc-alpha's message of "Tue, 3 May 2022 14:01:42 -0300") Message-ID: <8735hqe5i5.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 2.85 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Tue, 03 May 2022 20:17:20 -0000 * Adhemerval Zanella via Libc-alpha: > On 03/05/2022 13:57, Florian Weimer via Libc-alpha wrote: >> * H. J. Lu: >>=20 >>> On Tue, May 3, 2022 at 9:44 AM Florian Weimer wrot= e: >>>> >>>> * H. J. Lu: >>>> >>>>> On Tue, May 3, 2022 at 9:01 AM Florian Weimer wr= ote: >>>>>> >>>>>> * H. J. Lu: >>>>>> >>>>>>> The startup codes can't use cancellation before it is ready. Do we= need to >>>>>>> check SHARED in this case? >>>>>> >>>>>> I think __libc_fatal shouldn't be a cancellation point. That's not >>>>>> really related to SHARED. >>>>> >>>>> Should we define _startup_fatal unconditionally and always define >>>>> I386_USE_SYSENTER as 0 for i386 so that _startup_fatal can be >>>>> used safely during startup? >>>> >>>> Hmm. Isn't that what my patch does? >>>> >>> >>> Your patch still checks BUILD_PIE_DEFAULT and SHARED. >>=20 >> Ah, I see, thanks. You are right, the i386 version should define >> I386_USE_SYSENTER unconditionally. Will fix. > > I think you might want to check ia64 as well, since it uses a TCB variabl= e > to call the syscall in some cases. =E2=80=9Cmight want to check=E2=80=9C isn't a phrase I would use in the con= text with ia64, but yes, I can add a startup.h file for it, too. Thanks for the suggestion. Florian