From: Cyrill Gorcunov <gorcunov@openvz.org>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Sasha Levin <levinsasha928@gmail.com>,
khlebnikov@openvz.org, xemul@parallels.com,
Dave Jones <davej@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: c/r: broken locking when executing map_files
Date: Sat, 5 May 2012 22:53:06 +0400 [thread overview]
Message-ID: <20120505185306.GB28746@moon> (raw)
In-Reply-To: <20120505182051.GA16029@albatros>
On Sat, May 05, 2012 at 10:20:51PM +0400, Vasiliy Kulikov wrote:
...
> > ---
> > fs/proc/base.c | 8 +++-----
> > 1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > Index: linux-2.6.git/fs/proc/base.c
> > ===================================================================
> > --- linux-2.6.git.orig/fs/proc/base.c
> > +++ linux-2.6.git/fs/proc/base.c
> > @@ -2226,16 +2226,16 @@ static struct dentry *proc_map_files_loo
> > goto out;
> >
> > result = ERR_PTR(-EACCES);
> > - if (lock_trace(task))
> > + if (!ptrace_may_access(task, PTRACE_MODE_READ))
>
> Probably it will be better to change mutex_lock_killable() to
> mutex_lock_killable_nested() inside of lock_trace() instead of this change?
> It would keep the race-free check.
Yup, if I'm not missing something SINGLE_DEPTH_NESTING should do the trick
for us. I'll test and report.
Cyrill
next prev parent reply other threads:[~2012-05-05 18:53 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-02 17:23 c/r: broken locking when executing map_files Sasha Levin
2012-05-02 17:27 ` Cyrill Gorcunov
2012-05-03 17:31 ` Cyrill Gorcunov
2012-05-05 18:20 ` Vasiliy Kulikov
2012-05-05 18:53 ` Cyrill Gorcunov [this message]
2012-05-05 19:32 ` Cyrill Gorcunov
2012-05-06 20:21 ` Vasiliy Kulikov
2012-05-06 20:49 ` Cyrill Gorcunov
2012-05-11 17:56 ` Vasiliy Kulikov
2012-05-11 18:18 ` Cyrill Gorcunov
2012-05-02 17:34 ` Pavel Emelyanov
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