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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 E5534C433E0 for ; Thu, 9 Jul 2020 11:01:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF9932074B for ; Thu, 9 Jul 2020 11:01:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="j/UBLJYf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726914AbgGILBN (ORCPT ); Thu, 9 Jul 2020 07:01:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726302AbgGILBM (ORCPT ); Thu, 9 Jul 2020 07:01:12 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EB0BC061A0B for ; Thu, 9 Jul 2020 04:01:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=QzgcO9zT0nQ3JkZsYLfaohKLlobA0w2kWRQELU810mI=; b=j/UBLJYf6Qkcz6KaazMXp8JGO2 cMe3Vu7DUIPLVlDiT2fYpUgaUsoF4SvFsopWQTHrOCASIOqVs04PlUr/BGyVsQCcBNAnaBKjPkdsS MDXT2PhqYFIyg57W2e3VwkoBO6jrm9CL3kIxTwMTUoLbTfWHVZFfGYinWEBOSY+NWi8bchuQawDDx 00cmTzT3gXieLqbCxWfz4WgeJuiQj1VvN/0CF8t6LtLMC4zr0BZIlZjqfa/JkvkJqpJ2WXE/voXWD fllAVhkf5yABzpJy4LrE25A8KDy371F47cr/g+JY2evbT1yi4XSFSGCaQN4f6Z4QxrCOOE/QyXF9L kzxu0ojw==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jtUIe-0003Fl-1B; Thu, 09 Jul 2020 11:01:08 +0000 Date: Thu, 9 Jul 2020 12:01:07 +0100 From: Christoph Hellwig To: Will Deacon Cc: sanggil2.kim@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: kernel: Add module symbols _text, _etext. Message-ID: <20200709110107.GA12046@infradead.org> References: <1594283025-4166-1-git-send-email-sanggil2.kim@samsung.com> <20200709094950.GA28361@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200709094950.GA28361@willie-the-truck> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 09, 2020 at 10:49:51AM +0100, Will Deacon wrote: > On Thu, Jul 09, 2020 at 05:23:45PM +0900, sanggil2.kim@samsung.com wrote: > > From: Sanggil Kim > > > > We have a solution to protect kernel code section(autually from _text to > > _etext) by not MMU. In order to do this, we have to know the addresses > > of _text and _etext at runtime. > > Interesting! Can you post patches so that we can implement this solution > upstream? Without an in-tree user, we won't be exporting these symbols. And even with that I'm pretty sure the code doing the 'protection' should be built-in and not modular..