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-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS,URIBL_BLOCKED shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 3E2FC1F463 for ; Thu, 12 Dec 2019 12:46:53 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:references:date:in-reply-to :message-id:mime-version:content-type:content-transfer-encoding; q=dns; s=default; b=VhMbz2tX4wzg/eFj4C+aqV5UibAAijswa4Dl0tOe5F6 1FidKVqA1v6Iu0SXyVZyXxlbUVkiYXWHAnVeFnQbbfGxU5xtDPdUWzuiFKQ99KfY 3VuT8AZOEgy/958s5nQAOckK3u59Qo5gj4boLGHtdbyvRxi1ttQsc+pKmyU2z/zo = DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:references:date:in-reply-to :message-id:mime-version:content-type:content-transfer-encoding; s=default; bh=+T+ercUbiY0BBozvXo1ObPrSh9k=; b=J/KcsqbQW5NkTLw+Z eO6F/98nAm6dZd/i7yifqIa/U8qrPd57f6RYfBi5qXSwTACAM81xCu7up57W0EB6 TbIYb4YFfPpQE8WA4q3b1AjD0qTX1+0kEVXfeDMuCELmWJLivoRltEDaf0EcHczD HcKl98djfWscRfBmg0adO90lkY= Received: (qmail 127343 invoked by alias); 12 Dec 2019 12:46:51 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 127335 invoked by uid 89); 12 Dec 2019 12:46:50 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: us-smtp-delivery-1.mimecast.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576154808; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sRQg7aGc8A0/hv7kD4V/9kbEw3ABDjavvpDNCdrN+t0=; b=J6pz0Fr8YOiXt6/lT/fvGDNdQJubqUno2dzuGmCpck7n+74ulTdeX4HXwCx3is0o03FfI6 i2aIaCrLP0viFncZOu4JWADnij41mLzMvunup3xBgQAjvEo5E4ICn+6UdFok8+25Okzs4D CWKeSfClydcU7VNuYCOdNQuYPlI6DnY= From: Florian Weimer To: "H.J. Lu" Cc: libc-alpha@sourceware.org Subject: Re: [PATCH 0/4] i386: Finish CET support References: <20191210204710.4832-1-hjl.tools@gmail.com> Date: Thu, 12 Dec 2019 13:46:44 +0100 In-Reply-To: <20191210204710.4832-1-hjl.tools@gmail.com> (H. J. Lu's message of "Tue, 10 Dec 2019 12:47:06 -0800") Message-ID: <878snhhft7.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable * H. J. Lu: > This patch set finishes CET support on i386: > > 1. getcontext, setcontext and swapcontext are updated not to preserve > EAX, ECX and EDX. Since they are caller-saved, caller will reload them > after getcontext, setcontext and swapcontext calls if needed. The extra > scratch registers are used to enable CET. > 2. Add missing _CET_ENDBR to i386 assembly files. > 3. Enable CET support in i386 ucontext functions. > > Tested on i386 CET/non-CET machines. Has the kernel ABI been finalized? I wonder if we should add IFUNC resolvers which set a flag, and check that flag at the start of (some of) these functions, so that they cannot be used as ROP gadgets in programs that do not reference them. Thanks, Florian