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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 54507C34022 for ; Mon, 17 Feb 2020 20:12:52 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C22512070B for ; Mon, 17 Feb 2020 20:12:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fupp+Cin" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C22512070B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48LwC45RHGzDqg4 for ; Tue, 18 Feb 2020 07:12:48 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=207.211.31.81; helo=us-smtp-delivery-1.mimecast.com; envelope-from=joe.lawrence@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Fupp+Cin; dkim-atps=neutral Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48Lw980wm3zDqfb for ; Tue, 18 Feb 2020 07:11:05 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581970261; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=e8odtFTZCYiWfmn+20f/hTkWgD4uOk5mH7eoCP8r1tc=; b=Fupp+Cin2QWXro1bzJe9DN3e7FtGXbqoeDyzQDFeXi83/T0vGpdnJdnfhKsbZODGo6Un0v 7osV9gLxhxZSPHMhlrJSJlmuE/lMCHBpLMSzj2vYIbsj9q/97oZtjRZjL0L1xAVGlgrMYQ Wii1dAeqUhKgyfGZojdymzczo88cDtY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-185-QL9U2nwNMBqo1SfuBfCZkQ-1; Mon, 17 Feb 2020 11:08:58 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1B17318A8C80 for ; Mon, 17 Feb 2020 16:08:57 +0000 (UTC) Received: from redhat.com (dhcp-17-119.bos.redhat.com [10.18.17.119]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0DE7E60BE1; Mon, 17 Feb 2020 16:08:53 +0000 (UTC) Date: Mon, 17 Feb 2020 11:08:52 -0500 From: Joe Lawrence To: linuxppc-dev@lists.ozlabs.org Subject: vdso function descriptors (VDS64_HAS_DESCRIPTORS)? Message-ID: <20200217160852.GA9557@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: QL9U2nwNMBqo1SfuBfCZkQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" I was wondering if there was history behind VDS64_HAS_DESCRIPTORS and in what cases would one want to turn them on? (Note, I'm assuming they are an implementation of Function Descriptors. [1]) arch/powerpc/include/asm/vdso.h unsets the macro: /* Define if 64 bits VDSO has procedure descriptors */ #undef VDS64_HAS_DESCRIPTORS so I don't believe they are ever used by default -- in this case V_FUNCTION_BEGIN doesn't add to the .opd section with .name, .TOC base, etc. Manually setting VDS64_HAS_DESCRIPTORS results in a vdso64.so in which binutils tools like readelf properly report functions with symbol type FUNC instead of NOTYPE. Are there pieces of the build/etc toolchain unprepared for function descriptors? I'm just trying to figure out why the code defaults to unsetting them. Thanks, -- Joe [1] http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#FUNC-DE= S