From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 971B91F5AE for ; Wed, 29 Jul 2020 09:01:15 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id A486C3857C5F; Wed, 29 Jul 2020 09:01:14 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A486C3857C5F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1596013274; bh=Xcn3dDL39UqS1RqgX6a1WsEC0T7jlAy/rKBBvxX5QWc=; h=To:Subject:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=UeJzZmYQMMwfEGtjlyNTw6Nqdj/w89FXx3l9UfKe6LlJOrB9gEIQrlNxGfJEQI/Uz eWUTc6f+Mnb2iG3DkmGiXru/Bwckt1rTHqRC7Hy260x7g8g/nzCltqhG4dPZc0L+nh 72H+r8f9bYGKuxVnicYo09SmCks7mfTmq6/syNuo= Received: from us-smtp-delivery-74.mimecast.com (us-smtp-delivery-74.mimecast.com [216.205.24.74]) by sourceware.org (Postfix) with ESMTP id A68743858D35 for ; Wed, 29 Jul 2020 09:01:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A68743858D35 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-13-lR_w6Vw8Pi-wEtu-X27pug-1; Wed, 29 Jul 2020 05:01:10 -0400 X-MC-Unique: lR_w6Vw8Pi-wEtu-X27pug-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 646AD80572E; Wed, 29 Jul 2020 09:01:09 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-113-29.ams2.redhat.com [10.36.113.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 170F17191F; Wed, 29 Jul 2020 09:01:04 +0000 (UTC) To: Szabolcs Nagy Subject: Re: [PATCH] aarch64: update NEWS about branch protection References: <20200729080850.26078-1-szabolcs.nagy@arm.com> <87bljyspte.fsf@oldenburg2.str.redhat.com> <20200729084930.GS7127@arm.com> Date: Wed, 29 Jul 2020 11:01:03 +0200 In-Reply-To: <20200729084930.GS7127@arm.com> (Szabolcs Nagy's message of "Wed, 29 Jul 2020 09:49:31 +0100") Message-ID: <87lfj2r8z4.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (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-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: , From: Florian Weimer via Libc-alpha Reply-To: Florian Weimer Cc: Jakub Jelinek , libc-alpha@sourceware.org, jeremy.linton@arm.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" * Szabolcs Nagy: > The 07/29/2020 10:11, Florian Weimer wrote: >> * Szabolcs Nagy: >> >> > diff --git a/NEWS b/NEWS >> > index 1ef4a0a7a4..0e6ad5edc4 100644 >> > --- a/NEWS >> > +++ b/NEWS >> > @@ -70,7 +70,9 @@ Major new features: >> > >> > * AArch64 now supports standard branch protection security hardening >> > in glibc when it is built with a GCC that is configured with >> > - --enable-standard-branch-protection. This includes branch target >> > + --enable-standard-branch-protection (or if -mbranch-protection=standard >> > + flag is passed when building both GCC target libraries and glibc, >> > + in either case a custom GCC is needed). This includes branch target >> > identification (BTI) and pointer authentication for return addresses >> > (PAC-RET). They require armv8.5-a and armv8.3-a architecture >> > extensions respectively for the protection to be effective, >> >> Please clarify if you need to pass the flags in CFLAGS or CC for glibc. >> Thanks. > > cflags is enough, but it is hard to tell what > the glibc build system does with the various > cflags. > > if i simply override CFLAGS i get > # error "glibc cannot be compiled without optimization" Okay, I trust you that CFLAGS is enough. Are there any ELF notes I should watch out for? My RM delegation has already expired, so I cannot approve your patch. Thanks, Florian