From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752380AbbJTLQ6 (ORCPT ); Tue, 20 Oct 2015 07:16:58 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:45330 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751299AbbJTLQx (ORCPT ); Tue, 20 Oct 2015 07:16:53 -0400 X-AuditID: cbfec7f5-f794b6d000001495-ce-562622a27a96 Date: Tue, 20 Oct 2015 13:16:33 +0200 (CEST) From: Paul Osmialowski X-X-Sender: p.osmialowsk@AMDC1262.digital.local To: Andy Lutomirski Cc: Jonathan Corbet , Arnd Bergmann , Andrew Morton , Petr Mladek , Greg Kroah-Hartman , Daniel Mack , Kay Sievers , Joe Perches , Tejun Heo , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" , Linux API , Marcin Niesluchowski , Karol Lewandowski , Bartlomiej Zolnierkiewicz , Shuah Khan , Paul Osmialowski Subject: Re: [RFC v3 8/9] kmsg: add predefined _PID, _TID, _COMM keywords to kmsg* log dict In-reply-to: Message-id: References: <1445259503-18158-1-git-send-email-p.osmialowsk@samsung.com> <1445259503-18158-9-git-send-email-p.osmialowsk@samsung.com> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPIsWRmVeSWpSXmKPExsVy+t/xq7qLlNTCDK70mlnMWb+GzeLvpGPs FhtnrGe1eHKgndGi6e8rFovmxevZLGbff8xi0fhpLrPF5Q3n2Cw2f+9gs1jYtoTF4vKuOWwW q9c2sFocOvuDxWLCmwPMFgv/b2aymPrlA4vFr+VHGR2EPO6/+cvi8fvXJEaPTas62TxOzPjN 4rF/7hp2j8V9k1k9tvTfZff4suoas0ffllWMHmcWHGH3+LxJzuPjek+P7buXswTwRnHZpKTm ZJalFunbJXBlHG89yVbQzlWxaudU9gbGS+xdjJwcEgImEu8bFrNA2GISF+6tZ+ti5OIQEljK KHGncQMjhPOMUeLSpZPMXYwcHCwCOhK7byaANLAJGErc/H+YEaJZX+Lnr4dgQ0UENCVeTpnP AtLLLHCHVeLdlDVgRcICsRJ3m/6ygdicAsESPbfngNm8Ah4Se5Z0sUAsO8co8fPpI2aQhKiA rsShf3+gigQlfky+B3Yqs4ClRM+ZFUwTGAVmIUnNQpJawMi0ilE0tTS5oDgpPddIrzgxt7g0 L10vOT93EyMkGr/uYFx6zOoQowAHoxIPr0aMapgQa2JZcWXuIUYJDmYlEd42AbUwId6UxMqq 1KL8+KLSnNTiQ4zSHCxK4rwzd70PERJITyxJzU5NLUgtgskycXBKNTAunG8afuZ+gEX9lVZD xsmOXt/VD4X2n5t/dsu30n2Wy/f6zp1qccEl/a1GQtJVhQ2tmj+E/R0/C1xv0ag47nZ2/9li rgNyRy6onVlrMrnE6pTymcZTwb3nTZgYU44Xiaazc6hnf/jcfO1EiqLE6mspPxfYcIX9iP8h FNJov/es5bymI63yF64psRRnJBpqMRcVJwIALDL/0sICAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andy, On Mon, 19 Oct 2015, Andy Lutomirski wrote: > On Mon, Oct 19, 2015 at 5:58 AM, Paul Osmialowski > wrote: >> From: Marcin Niesluchowski >> >> kmsg* devices write operation wrote no dict along with message >> Due to usage of kmsg devices in userspace dict has been added >> identifying pid, tid and comm of writing process. > > Does this affect even the normal /dev/kmsg? Yes. > >> -static int kmsg_sys_write(int minor, int level, const char *fmt, ...) >> +static size_t set_kmsg_dict(char *buf) >> +{ >> + size_t len; >> + >> + len = sprintf(buf, "_PID=%d", task_tgid_nr(current)) + 1; >> + len += sprintf(buf + len, "_TID=%d", task_pid_nr(current)) + 1; >> + memcpy(buf + len, "_COMM=", 6); >> + len += 6; >> + get_task_comm(buf + len, current); >> + while (buf[len] != '\0') >> + len++; > > len += strlen(buf); ? > > Is it obvious for some reason that this doesn't overflow buf? > KMSG_DICT_MAX_LEN sets architecture-intepentent max size. > Why is task_pid_nr acceptable here? Isn't this intended for use in namespaces? > task_tgid_nr - process id (pid as seen in userspace), task_pid_nr - thread id Thanks, Paul