From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754077Ab2AWUxi (ORCPT ); Mon, 23 Jan 2012 15:53:38 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:38518 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753255Ab2AWUxd (ORCPT ); Mon, 23 Jan 2012 15:53:33 -0500 Date: Tue, 24 Jan 2012 00:53:28 +0400 From: Cyrill Gorcunov To: Kees Cook Cc: linux-kernel@vger.kernel.org, Andrew Morton , Pavel Emelyanov , Serge Hallyn , KAMEZAWA Hiroyuki , Tejun Heo , Andrew Vagin , "Eric W. Biederman" , Alexey Dobriyan , Vasiliy Kulikov Subject: Re: [patch 3/4] c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat Message-ID: <20120123205328.GM1907@moon> References: <20120123142036.025893883@openvz.org> <20120123142436.336126707@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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 Mon, Jan 23, 2012 at 12:42:28PM -0800, Kees Cook wrote: > On Mon, Jan 23, 2012 at 6:20 AM, Cyrill Gorcunov wrote: > > We would like to have an ability to restore command line > > arguments and envirion pointers so the task being restored > > would print appropriate values in /proc/pid/cmdline and > > /proc/pid/envirion. The exit_code is needed to restore > > zombie tasks. > > > > Signed-off-by: Cyrill Gorcunov > > Cc: Pavel Emelyanov > > Cc: Serge Hallyn > > Cc: Kees Cook > > Cc: KAMEZAWA Hiroyuki > > Cc: Alexey Dobriyan > > Cc: Tejun Heo > > Cc: Andrew Vagin > > Cc: Vasiliy Kulikov > > Cc: Alexey Dobriyan > > Cc: "Eric W. Biederman" > > --- > >  fs/proc/array.c |   10 ++++++++-- > >  1 file changed, 8 insertions(+), 2 deletions(-) > > > > Index: linux-2.6.git/fs/proc/array.c > > =================================================================== > > --- linux-2.6.git.orig/fs/proc/array.c > > +++ linux-2.6.git/fs/proc/array.c > > @@ -464,7 +464,8 @@ static int do_task_stat(struct seq_file > > > >        seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \ > >  %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \ > > -%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu\n", > > +%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu \ > > +%lu %lu %lu %lu %d\n", > >                pid_nr_ns(pid, ns), > >                tcomm, > >                state, > > @@ -514,7 +515,12 @@ static int do_task_stat(struct seq_file > >                cputime_to_clock_t(cgtime), > >                (mm && permitted) ? mm->start_data : 0, > >                (mm && permitted) ? mm->end_data : 0, > > -               (mm && permitted) ? mm->start_brk : 0); > > +               (mm && permitted) ? mm->start_brk : 0, > > +               (mm && permitted) ? mm->arg_start : 0, > > +               (mm && permitted) ? mm->arg_end : 0, > > +               (mm && permitted) ? mm->env_start : 0, > > +               (mm && permitted) ? mm->env_end : 0, > > +               task->exit_code); > >        if (mm) > >                mmput(mm); > >        return 0; > > You're not exposing auxv here? In your testing, what situations ended > up using auxv after initial startup? Or is your intention to be able > to freeze a process potentially before libc has examined auxv? > auxv already available via /proc/pid/auxv so I thought it would be redundant to put it into different place. Or you meant something else? In testing I simply read auxv values from /proc/pid/auxv and restore them back via prctl at restore time. (prctl patch is in this series but it's slightly buggy so I post correct version later). And intention is simply dump this vector at checkpoint time and restore when needed. Cyrill