Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757616AbYA1KEP (ORCPT ); Mon, 28 Jan 2008 05:04:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752550AbYA1KEA (ORCPT ); Mon, 28 Jan 2008 05:04:00 -0500 Received: from sacred.ru ([62.205.161.221]:36546 "EHLO sacred.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543AbYA1KD7 (ORCPT ); Mon, 28 Jan 2008 05:03:59 -0500 Message-ID: <479DA711.3080301@openvz.org> Date: Mon, 28 Jan 2008 12:57:37 +0300 From: Pavel Emelyanov User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: Andrew Morton , Vinay Sridhar CC: linux-kernel@vger.kernel.org, libc-alpha@sourceware.org, drepper@redhat.com, wli@holomorphy.com, sripathik@in.ibm.com, "Eric W. Biederman" Subject: Re: [RFC] Per-thread getrusage References: <1200558425.5992.17.camel@srivinay.in.ibm.com> <20080127215242.b873c341.akpm@linux-foundation.org> <479D88C7.5030101@openvz.org> <20080128011010.d162d336.akpm@linux-foundation.org> <479DA289.7090403@openvz.org> <20080128014534.17630ddd.akpm@linux-foundation.org> In-Reply-To: <20080128014534.17630ddd.akpm@linux-foundation.org> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (sacred.ru [62.205.161.221]); Mon, 28 Jan 2008 12:57:21 +0300 (MSK) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1852 Lines: 45 Andrew Morton wrote: > On Mon, 28 Jan 2008 12:38:17 +0300 Pavel Emelyanov wrote: > >>> If the code was using find_task_by_vpid() then OK (I guess). But it is >> Yup, find_task_by_vpid() will find the proper (i.e. in your namespace) task. >> >>> looking the tids up in the init_pid_ns. Which I assume means that if it's >>> in a new namespace and is looking up a sibling thread it will simply fail? >> If it looks in the init_pid_ns, then it can either fail or obtain a task >> from different namespace. The find_task_by_pid_ns() was intended to be used >> in proc mainly, to get tasks from the namespace pointed by the super-block >> being explored. >> >> Please excuse my lamentable ignorance, but which code does such things with >> init_pid_ns? I followed the 'per-thread rusage' thread and didn't find any. > > From: Vinay Sridhar > To: linux-kernel@vger.kernel.org, libc-alpha@sourceware.org > Cc: drepper@redhat.com, wli@holomorphy.com, akpm@linux-foundation.org, sripathik@in.ibm.com > Subject: [RFC] Per-thread getrusage Ouch. Thanks, I've missed that and looked just at the Roland's patch :( > ... > +asmlinkage long sys_thread_getrusage(int tid, struct rusage __user *ru) > +{ > + struct task_struct *tsk; > + tsk = find_task_by_pid(tid); > + return getrusage(tsk, RUSAGE_THREAD, ru); > +} Well, the find_task_by_pid() is really wrong here. Besides (just in case this system call is going to be developed further), the tsk == NULL case is not checked inside the getrusage and may OOPS even if the proper namespace is used. Thanks, Pavel -- 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/