Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754495AbXKEV5A (ORCPT ); Mon, 5 Nov 2007 16:57:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752045AbXKEV4w (ORCPT ); Mon, 5 Nov 2007 16:56:52 -0500 Received: from wine.ocn.ne.jp ([122.1.235.145]:51327 "EHLO smtp.wine.ocn.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751887AbXKEV4v (ORCPT ); Mon, 5 Nov 2007 16:56:51 -0500 To: pavel@ucw.cz, torvalds@linux-foundation.org Cc: darwish.07@gmail.com, casey@schaufler-ca.com, akpm@linux-foundation.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, viro@ftp.linux.org.uk Subject: Re: [PATCH] Smackv10: Smack rules grammar + their stateful parser From: Tetsuo Handa References: <472B8DAF.9080706@schaufler-ca.com> <20071103164303.GA26707@ubuntu> <20071104122848.GC3921@ucw.cz> <20071105094007.GA19367@ubuntu> In-Reply-To: Message-Id: <200711060656.ADF87510.tJLVFOHOFSOFMQ@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.50 PL2] X-Accept-Language: ja,en Date: Tue, 6 Nov 2007 06:56:43 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1168 Lines: 25 Linus Torvalds wrote: > I personally think string parsers are *much* better than the alternatives > (which basically boil down to nasty binary interfaces) Me too. > Binary structures and ioctl's are *much* worse. They are totally > undebuggable with generic tools (think "echo" or "strace"), and they are a > total nightmare to parse across architectures and pointer sizes. Not only pointer sizes bugs, but also checking pointer address costs. For binary policy, we have to examine ->next pointer is valid or not. We can't blindly use address supplied from userland. I have encountered mismatch of kernel version and AppArmor's policy parser version when I just updated only kernel. As a result, the segmentation faults rushed toward me. From this experience, TOMOYO still uses string parser in the kernel. If a parser doesn't consume much stack (i.e. call functions recursively), I think it is no problem. Thanks. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/