From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id A870DB6FBE for ; Thu, 9 Jun 2011 02:39:42 +1000 (EST) Date: Wed, 8 Jun 2011 18:36:53 +0200 From: Oleg Nesterov To: Eric Paris Subject: Re: [PATCH -v2] Audit: push audit success and retcode into arch ptrace.h Message-ID: <20110608163653.GA9592@redhat.com> References: <20110603220451.23134.47368.stgit@paris.rdu.redhat.com> <20110607171952.GA25729@redhat.com> <1307472796.2052.12.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1307472796.2052.12.camel@localhost.localdomain> Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, heiko.carstens@de.ibm.com, paulus@samba.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-s390@vger.kernel.org, richard@nod.at, x86@kernel.org, mingo@redhat.com, fenghua.yu@intel.com, user-mode-linux-devel@lists.sourceforge.net, microblaze-uclinux@itee.uq.edu.au, jdike@addtoit.com, viro@zeniv.linux.org.uk, tglx@linutronix.de, monstr@monstr.eu, tony.luck@intel.com, linux-kernel@vger.kernel.org, ralf@linux-mips.org, lethal@linux-sh.org, schwidefsky@de.ibm.com, linux390@de.ibm.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 06/07, Eric Paris wrote: > > On Tue, 2011-06-07 at 19:19 +0200, Oleg Nesterov wrote: > > > > With or without this patch, can't we call audit_syscall_exit() twice > > if there is something else in _TIF_WORK_SYSCALL_EXIT mask apart from > > SYSCALL_AUDIT ? First time it is called from asm, then from > > syscall_trace_leave(), no? > > > > For example. The task has TIF_SYSCALL_AUDIT and nothing else, it does > > system_call->auditsys->system_call_fastpath. What if it gets, say, > > TIF_SYSCALL_TRACE before ret_from_sys_call? > > No harm is done calling twice. The first call will do the real work and > cleanup. It will set a flag in the audit data that the work has been > done (in_syscall == 0) thus the second call will then not do any real > work and won't have anything to clean up. Hmm... and I assume context->previous != NULL is not possible on x86_64. OK, thanks. And I guess, all CONFIG_AUDITSYSCALL code in entry.S is only needed to microoptimize the case when TIF_SYSCALL_AUDIT is the only reason for the slow path. I wonder if it really makes the measureble difference... Oleg.