From: Roger Luethi <rl@hellgate.ch>
To: Marc Ballarin <Ballarin.Marc@gmx.de>
Cc: rob@landley.net, linux-kernel@vger.kernel.org
Subject: Re: Interesting race condition...
Date: Fri, 30 Jul 2004 10:38:15 +0200 [thread overview]
Message-ID: <20040730083815.GA16881@k3.hellgate.ch> (raw)
In-Reply-To: <20040730102726.57519859.Ballarin.Marc@gmx.de>
On Fri, 30 Jul 2004 10:27:26 +0200, Marc Ballarin wrote:
> > --- linux-2.6.8-rc2-bk1/fs/proc/base.c.orig 2004-07-30 01:43:23.535967505 +0200
> > +++ linux-2.6.8-rc2-bk1/fs/proc/base.c 2004-07-30 01:43:27.428303752 +0200
> > @@ -329,6 +329,8 @@ static int proc_pid_cmdline(struct task_
> > struct mm_struct *mm = get_task_mm(task);
> > if (!mm)
> > goto out;
> > + if (!mm->arg_end)
> > + goto out; /* Shh! No looking before we're done */
> >
> > len = mm->arg_end - mm->arg_start;
> >
>
> Yes, this seems to fix it. First I replaced "goto out" with a printk, and
> the printks matched the occurence of the bug.
> However, I got multiple printks per bug (between 2 and 7). Is that
> supposed to happen?
Every time we proceed through proc_pid_cmdline with mm->arg_end == 0 is a
bug. AFAICT anyway. Whether you see an "occurence of the bug" depends on
how you measure it. Of course you are wecome to add more printks following
the code path to see how and when it propagates to where you are catching
it.
Roger
next prev parent reply other threads:[~2004-07-30 8:38 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-23 3:04 Interesting race condition Rob Landley
2004-07-23 7:33 ` Barry K. Nathan
2004-07-23 7:56 ` Hugo Mills
2004-07-24 8:13 ` Rob Landley
2004-07-24 13:40 ` Marc Ballarin
2004-07-26 16:04 ` David Weinehall
2004-07-26 17:20 ` Marc Ballarin
2004-07-23 10:01 ` P. Benie
2004-07-24 8:17 ` Rob Landley
2004-07-24 9:08 ` P. Benie
2004-07-27 20:40 ` Bill Davidsen
2004-07-28 8:00 ` Paul Jackson
2004-08-04 20:03 ` Robert White
2004-08-04 20:42 ` Roger Luethi
2004-07-28 8:05 ` Paul Jackson
2004-07-28 11:54 ` Marc Ballarin
2004-07-28 16:46 ` Rob Landley
2004-07-28 16:42 ` Rob Landley
2004-07-28 17:08 ` Tristan Wibberley
2004-07-29 23:56 ` Roger Luethi
2004-07-30 0:18 ` Jesper Juhl
2004-07-30 0:22 ` Jesper Juhl
2004-07-30 8:27 ` Marc Ballarin
2004-07-30 8:38 ` Roger Luethi [this message]
2004-08-20 10:15 ` Lee Revell
2004-08-20 12:51 ` Marc Ballarin
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