Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752386AbaDZRmq (ORCPT ); Sat, 26 Apr 2014 13:42:46 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:35795 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752000AbaDZRmp (ORCPT ); Sat, 26 Apr 2014 13:42:45 -0400 Date: Sat, 26 Apr 2014 18:42:29 +0100 From: Al Viro To: Dmitry Kasatkin Cc: "Eric W. Biederman" , Oleg Nesterov , Dmitry Kasatkin , linux-security-module , John Johansen , Mimi Zohar , James Morris , Linux Kernel Mailing List , kernel-team Subject: Re: Kernel panic at Ubuntu: IMA + Apparmor Message-ID: <20140426174229.GG18016@ZenIV.linux.org.uk> References: <874n1h16le.fsf@x220.int.ebiederm.org> <87iopxxfpp.fsf@x220.int.ebiederm.org> <87lhutt4ph.fsf@x220.int.ebiederm.org> <20140426135616.GE18016@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 26, 2014 at 07:54:47PM +0300, Dmitry Kasatkin wrote: > On 26 April 2014 16:56, Al Viro wrote: > > On Sat, Apr 26, 2014 at 11:58:45AM +0300, Dmitry Kasatkin wrote: > > > >> Conflict with Apparmor means with Ubuntu. > >> > >> But answering to your early question.. > >> IMA does not want permission denied when measuring and re-measuring files. > >> may_open() is doing that job before. > >> > >> We need quickly introduce kernel_read without LSM checks... > > > > *snarl* > > > > What we need quickly is to introduce you to a textbook or two. As the > > matter of fact, in this case even wikipedia might suffice... > > > > Hopefully we have you who were introduced to a textbook or two about relevant > subject and able kindly help us with the solution instead of telling > me this crap... See the discussion of that very topic (required modifications of vfs_read()) upthread. And Eric has a very good point about the usefulness of understanding the basics of IO-related system calls in Unix for anybody who does any kind of development related to keeping track of file contents modifications, etc. It's *not* about some arcane knowledge of VFS internals (which also might come handy when sticking hooks into said internals); it's about being familiar with the semantics of read(2) and related concepts. -- 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/