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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C892EC433E0 for ; Mon, 3 Aug 2020 19:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 583D0207DF for ; Mon, 3 Aug 2020 19:38:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Zxj6K0Xh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728174AbgHCTi6 (ORCPT ); Mon, 3 Aug 2020 15:38:58 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:55716 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727813AbgHCTi5 (ORCPT ); Mon, 3 Aug 2020 15:38:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596483536; 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=KwaJzAuhKp0eMDKUyFcMapFzk1bqmh48WPQrufCV124=; b=Zxj6K0XhuJdbuSpf0YCx6zwtDxGc0m8ijyP5CBbtiS+0GgsDRERyiRxlSpXZBcueTrg7BP hd7VFDFmuz7pIN6AIwq4aEy27a9IY+DTRVjTYudhOKtLCnDqOEhOV4dTxCW8pQoqlecgF1 TTrbsFUb7m5aGJtQhMzYg4kRmXPnWCE= 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-403-POlseAWyM4uGgMhDrzYE7A-1; Mon, 03 Aug 2020 15:38:54 -0400 X-MC-Unique: POlseAWyM4uGgMhDrzYE7A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EB7B8106B24B; Mon, 3 Aug 2020 19:38:51 +0000 (UTC) Received: from redhat.com (ovpn-112-64.phx2.redhat.com [10.3.112.64]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 985DA69319; Mon, 3 Aug 2020 19:38:41 +0000 (UTC) Received: from fche by redhat.com with local (Exim 4.94) (envelope-from ) id 1k2gI9-0008Bt-GP; Mon, 03 Aug 2020 15:38:37 -0400 Date: Mon, 3 Aug 2020 15:38:37 -0400 From: "Frank Ch. Eigler" To: Joe Lawrence Cc: Kees Cook , Evgenii Shatokhin , Kristen Carlson Accardi , Miroslav Benes , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, arjan@linux.intel.com, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, rick.p.edgecombe@intel.com, live-patching@vger.kernel.org, Josh Poimboeuf , Jessica Yu Subject: Re: [PATCH v4 00/10] Function Granular KASLR Message-ID: <20200803193837.GB30810@redhat.com> References: <20200717170008.5949-1-kristen@linux.intel.com> <202008031043.FE182E9@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: live-patching-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org Hi - > > While this does seem to be the right solution for the extant problem, I > > do want to take a moment and ask if the function sections need to be > > exposed at all? What tools use this information, and do they just want > > to see the bounds of the code region? (i.e. the start/end of all the > > .text* sections) Perhaps .text.* could be excluded from the sysfs > > section list? > [[cc += FChE, see [0] for Evgenii's full mail ]] Thanks! > It looks like debugging tools like systemtap [1], gdb [2] and its > add-symbol-file cmd, etc. peek at the /sys/module//section/ info. > But yeah, it would be preferable if we didn't export a long sysfs > representation if nobody actually needs it. Systemtap needs to know base addresses of loaded text & data sections, in order to perform relocation of probe point PCs and context data addresses. It uses /sys/module/...., kind of under protest, because there seems to exist no MODULE_EXPORT'd API to get at that information some other way. - FChE