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 3F1303858D1E for ; Fri, 11 Feb 2022 14:57:04 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3F1303858D1E Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-153-e1AIAhxLOd-Zem6at4cITQ-1; Fri, 11 Feb 2022 09:57:00 -0500 X-MC-Unique: e1AIAhxLOd-Zem6at4cITQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3795856AC5; Fri, 11 Feb 2022 14:56:59 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.205]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2C26E5B280; Fri, 11 Feb 2022 14:56:58 +0000 (UTC) From: Florian Weimer To: "H.J. Lu" Cc: Adhemerval Zanella , Szabolcs Nagy , GNU C Library Subject: Re: [PATCH v2 5/5] Linux: Consolidate auxiliary vector parsing References: <151c5398adbbe538a275ea5ac77705b0abd0d748.1643886336.git.fweimer@redhat.com> <20220211123110.GB2692478@arm.com> <0dea5e89-25fb-3e17-8142-878482f171dd@linaro.org> <20220211132419.GC2692478@arm.com> <4d632b0d-191e-064b-d316-7614173561b7@linaro.org> Date: Fri, 11 Feb 2022 15:56:56 +0100 In-Reply-To: (H. J. Lu's message of "Fri, 11 Feb 2022 06:42:48 -0800") Message-ID: <871r09v4cn.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 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.1 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: Fri, 11 Feb 2022 14:57:05 -0000 * H. J. Lu: > I ran into a similar problem on my CET branch. In my case, it is memcmp. > I added a new header file, , to define functions which can be safely > used during ld.so startup: > > https://gitlab.com/x86-glibc/glibc/-/commit/2bfa258b114e556ab0be68d6465b5e4fa5504e2e I think we would need something using assembler-level redirects because we need to change where the compiler-generated calls go. We probably need an adjustment to sysdeps/generic/symbol-hacks.h, and teach the stack protector controls to affect the symbol redirects (I think the requirements around TCB initialization are identical). Thanks, Florian