From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754843Ab1FHTWX (ORCPT ); Wed, 8 Jun 2011 15:22:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28846 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753952Ab1FHTWU (ORCPT ); Wed, 8 Jun 2011 15:22:20 -0400 Date: Wed, 8 Jun 2011 21:19:10 +0200 From: Oleg Nesterov To: Eric Paris Cc: linux-kernel@vger.kernel.org, tony.luck@intel.com, fenghua.yu@intel.com, monstr@monstr.eu, ralf@linux-mips.org, benh@kernel.crashing.org, paulus@samba.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, linux390@de.ibm.com, lethal@linux-sh.org, davem@davemloft.net, jdike@addtoit.com, richard@nod.at, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, linux-ia64@vger.kernel.org, microblaze-uclinux@itee.uq.edu.au, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Subject: Re: [PATCH -v2] Audit: push audit success and retcode into arch ptrace.h Message-ID: <20110608191910.GA18698@redhat.com> References: <20110603220451.23134.47368.stgit@paris.rdu.redhat.com> <20110607171952.GA25729@redhat.com> <1307472796.2052.12.camel@localhost.localdomain> <20110608163653.GA9592@redhat.com> <1307556823.2577.5.camel@localhost.localdomain> <20110608183720.GA16883@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110608183720.GA16883@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/08, Oleg Nesterov wrote: > > OK. Thanks a lot Eric for your explanations. Yes. but may I ask another one? Shouldn't copy_process()->audit_alloc(tsk) path do clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT) if it doesn't set tsk->audit_context? I can be easily wrong, but afaics otherwise the child can run with TIF_SYSCALL_AUDIT bit copied from parent's thread_info by dup_task_struct()->setup_thread_stack() and without ->audit_context, right? For what? Any other reason why audit_syscall_entry() checks context != NULL? IOW. Any reason the patch below is wrong? I am just curious, thanks. Oleg. --- x/kernel/auditsc.c +++ x/kernel/auditsc.c @@ -885,6 +885,8 @@ int audit_alloc(struct task_struct *tsk) if (likely(!audit_ever_enabled)) return 0; /* Return if not auditing. */ + clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + state = audit_filter_task(tsk, &key); if (likely(state == AUDIT_DISABLED)) return 0; @@ -1591,9 +1593,7 @@ void audit_syscall_entry(int arch, int m struct audit_context *context = tsk->audit_context; enum audit_state state; - if (unlikely(!context)) - return; - + BUG_ON(!context); /* * This happens only on certain architectures that make system * calls in kernel_thread via the entry.S interface, instead of