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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50EA6C433EF for ; Wed, 11 May 2022 18:35:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346339AbiEKSfN (ORCPT ); Wed, 11 May 2022 14:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230328AbiEKSfK (ORCPT ); Wed, 11 May 2022 14:35:10 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2D41F2016C7 for ; Wed, 11 May 2022 11:35:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652294107; 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: in-reply-to:in-reply-to:references:references; bh=ZMtErVFfS/m2VnbDfTyVmDkgaJUK2RAuBSLDTdhHZhI=; b=PRvPloiXo+y6VOleFW9q+YoNpyQwf4YDX0Z23QUyTNUAwCEJkKEhcMRlyHLfja2nbOst4H WPOXTjizpl500MWNt1IMLQkCW7DXUWPV6iT2vVwzjQq5UFAmLSyEr7aemuVdJTa0TGDIu7 ujsjjVtc7xrJPp13d38yXtf4GIk0a4I= 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-301-YbUa_GYzN36BexPqS0BPww-1; Wed, 11 May 2022 14:35:05 -0400 X-MC-Unique: YbUa_GYzN36BexPqS0BPww-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 3FC01803D45; Wed, 11 May 2022 18:35:05 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0694D54F403; Wed, 11 May 2022 18:35:03 +0000 (UTC) From: Florian Weimer To: Andy Lutomirski Cc: x86@kernel.org, LKML , Kees Cook Subject: Re: [PATCH] x86/vsyscall: Remove CONFIG_LEGACY_VSYSCALL_EMULATE References: <898932fe61db6a9d61bc2458fa2f6049f1ca9f5c.1652290558.git.luto@kernel.org> Date: Wed, 11 May 2022 20:35:02 +0200 In-Reply-To: <898932fe61db6a9d61bc2458fa2f6049f1ca9f5c.1652290558.git.luto@kernel.org> (Andy Lutomirski's message of "Wed, 11 May 2022 10:38:53 -0700") Message-ID: <87o803dijt.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski: > CONFIG_LEGACY_VSYSCALL_EMULATE is, as far as I know, only needed for the > combined use of exotic and outdated debugging mechanisms with outdated > binaries. At this point, no one should be using it. We would like to > implement dynamic switching of vsyscalls, but this is much more > complicated to support in EMULATE mode than XONLY mode. > > So let's force all the distros off of EMULATE mode. If anyone actually > needs it, they can set vsyscall=emulate, and we can then get away with > refusing to support newer security models if that option is set. > > Cc: x86@kernel.org > Cc: Kees Cook > Cc: Florian Weimer > Signed-off-by: Andy Lutomirski Sounds a good idea to me. Acked-by: Florian Weimer Regarding the mechanics, is it customary to remove the actual code (the EMULATE enum constant) in later commits? Thanks, Florian