From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Milos Vyletel <milos@redhat.com>,
Prarit Bhargava <prarit@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/8] stop_machine: cpu_stopper_thread() must check done != NULL
Date: Tue, 17 Nov 2015 18:53:09 +0100 [thread overview]
Message-ID: <20151117175309.GA16154@redhat.com> (raw)
In-Reply-To: <20151116185221.GK18894@mtj.duckdns.org>
On 11/16, Tejun Heo wrote:
>
> On Sun, Nov 15, 2015 at 08:33:11PM +0100, Oleg Nesterov wrote:
> > stop_one_cpu_nowait(fn) will crash the kernel if the callback returns
> > nonzero, work->done == NULL in this case.
> >
> > This needs more cleanups, cpu_stop_signal_done() is called right after
> > we check done != NULL and it does the same check.
> >
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
>
> Acked-by: Tejun Heo <tj@kernel.org>
Thanks!
> cc stable?
Yes, I was going to add -stable initially. And perhaps this makes sense
anyway, the patch is really trivial.
OTOH I have checked the history, none of cpu_stop_signal_done's callbacks
ever returned non-zero, so I decided to not spam -stable.
Oleg.
next prev parent reply other threads:[~2015-11-17 16:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-15 19:32 [PATCH 0/8] stop_machine: stop_one_cpu_nowait() fix, misc cleanups Oleg Nesterov
2015-11-15 19:33 ` [PATCH 1/8] stop_machine: cpu_stopper_thread() must check done != NULL Oleg Nesterov
2015-11-16 18:52 ` Tejun Heo
2015-11-17 17:53 ` Oleg Nesterov [this message]
2015-11-23 16:21 ` [tip:sched/core] stop_machine: Fix possible cpu_stopper_thread() crash tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 2/8] stop_machine: don't disable preemption in stop_two_cpus() Oleg Nesterov
2015-11-23 16:21 ` [tip:sched/core] stop_machine: Don' t " tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 3/8] stop_machine: make cpu_stop_queue_work() and stop_one_cpu_nowait() return bool Oleg Nesterov
2015-11-17 17:05 ` [PATCH v2 " Oleg Nesterov
2015-11-17 18:05 ` Peter Zijlstra
2015-11-23 16:22 ` [tip:sched/core] stop_machine: Make " tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 4/8] stop_machine: change stop_one_cpu() to rely on cpu_stop_queue_work() Oleg Nesterov
2015-11-23 16:22 ` [tip:sched/core] stop_machine: Change " tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 5/8] stop_machine: change __stop_cpus() " Oleg Nesterov
2015-11-23 16:22 ` [tip:sched/core] stop_machine: Change " tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 6/8] stop_machine: kill cpu_stop_done->executed Oleg Nesterov
2015-11-23 16:23 ` [tip:sched/core] stop_machine: Kill cpu_stop_done->executed tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 7/8] stop_machine: shift the done != NULL check from cpu_stop_signal_done() to callers Oleg Nesterov
2015-11-23 16:23 ` [tip:sched/core] stop_machine: Shift the 'done != NULL' " tip-bot for Oleg Nesterov
2015-11-15 19:33 ` [PATCH 8/8] stop_machine: cleanup the usage of preemption counter in cpu_stopper_thread() Oleg Nesterov
2015-11-16 19:10 ` Tejun Heo
2015-11-23 16:23 ` [tip:sched/core] stop_machine: Clean up the usage of the " tip-bot for Oleg Nesterov
2015-11-16 9:43 ` [PATCH 0/8] stop_machine: stop_one_cpu_nowait() fix, misc cleanups Peter Zijlstra
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