From: Frederic Weisbecker <frederic@kernel.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
Oleg Nesterov <oleg@redhat.com>,
Pengfei Xu <pengfei.xu@intel.com>,
Boqun Feng <boqun.feng@gmail.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
rcu@vger.kernel.org
Subject: Re: [PATCH 0/3] rcu-tasks: Fix race against exiting pid_ns
Date: Fri, 2 Dec 2022 23:55:34 +0100 [thread overview]
Message-ID: <20221202225534.GB1754872@lothringen> (raw)
In-Reply-To: <20221129144834.GW4001@paulmck-ThinkPad-P17-Gen-1>
On Tue, Nov 29, 2022 at 06:48:34AM -0800, Paul E. McKenney wrote:
> On Tue, Nov 29, 2022 at 10:55:00AM +0100, Frederic Weisbecker wrote:
> > On Mon, Nov 28, 2022 at 04:22:40PM -0800, Paul E. McKenney wrote:
> > > On Fri, Nov 25, 2022 at 02:54:57PM +0100, Frederic Weisbecker wrote:
> > > > Pengfei Xu has reported a deadlock involving calls to unshare(),
> > > > perf_event_open() and clone3() calls. It requires CAP_SYS_ADMIN
> > > > to reproduce (at least I don't see a way for a non privilege process to
> > > > reproduce).
> > > >
> > > > See this thread for details: https://lore.kernel.org/all/Y3sOgrOmMQqPMItu@xpf.sh.intel.com/
> > > > And this document for the collaborative analysis with Boqun, Paul and Neeraj:
> > > > https://docs.google.com/document/d/1hJxgiZ5TMZ4YJkdJPLAkRvq7sYQ-A7svgA8no6i-v8k
> > > >
> > > > The two first patches are small improvements. The fix is in the last patch.
> > > >
> > > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> > > > rcu/dev
> > > >
> > > > HEAD: 45ef5a0a4be4e0db9eadcc86e8f346d34c62e744
> > >
> > > Hearing no objections, queued for further review and testing.
> > >
> > > And thank you very much! That race between synchronize_rcu_tasks() and
> > > zap_pid_ns_processes() certainly was more than a bit on the non-trivial
> > > side. Good show!!!
> >
> > Thanks!
> >
> > Also please replace the last patch with the following to fix
> > a !CONFIG_RCU_TASKS issue:
>
> Like this? ;-)
>
> a0c355bbdfee ("squash! rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()")
You got it! :)
prev parent reply other threads:[~2022-12-02 22:55 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-25 13:54 [PATCH 0/3] rcu-tasks: Fix race against exiting pid_ns Frederic Weisbecker
2022-11-25 13:54 ` [PATCH 1/3] rcu-tasks: Improve comments explaining tasks_rcu_exit_srcu purpose Frederic Weisbecker
2022-11-25 13:54 ` [PATCH 2/3] rcu-tasks: Remove preemption disablement around srcu_read_[un]lock() calls Frederic Weisbecker
2022-11-25 13:55 ` [PATCH 3/3] rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() Frederic Weisbecker
2022-11-30 18:37 ` Eric W. Biederman
2022-12-02 19:51 ` Paul E. McKenney
2022-12-02 22:54 ` Frederic Weisbecker
2022-12-02 23:28 ` Eric W. Biederman
2022-12-04 0:03 ` Frederic Weisbecker
2022-12-06 16:49 ` Oleg Nesterov
2022-12-07 14:34 ` Paul E. McKenney
2022-12-07 20:01 ` Frederic Weisbecker
2022-12-07 20:39 ` Oleg Nesterov
2022-12-09 20:26 ` Frederic Weisbecker
2022-11-29 0:22 ` [PATCH 0/3] rcu-tasks: Fix race against exiting pid_ns Paul E. McKenney
2022-11-29 9:55 ` Frederic Weisbecker
2022-11-29 14:48 ` Paul E. McKenney
2022-12-02 22:55 ` Frederic Weisbecker [this message]
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