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From: Ingo Molnar <mingo@kernel.org>
To: Tejun Heo <tj@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	Ingo Molnar <mingo@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	yrl.pp-manager.tt@hitachi.com
Subject: Re: [PATCH -tip ] [BUGFIX] kprobes: Fix a double lock bug of kprobe_mutex
Date: Fri, 19 Apr 2013 09:22:50 +0200	[thread overview]
Message-ID: <20130419072250.GA20897@gmail.com> (raw)
In-Reply-To: <20130418181709.GE9897@mtj.dyndns.org>


* Tejun Heo <tj@kernel.org> wrote:

> On Thu, Apr 18, 2013 at 06:33:18PM +0900, Masami Hiramatsu wrote:
> > Fix a double locking bug caused when debug.kprobe-optimization=0.
> > While the proc_kprobes_optimization_handler locks kprobe_mutex,
> > wait_for_kprobe_optimizer locks it again and that causes a double lock.
> > To fix the bug, this introduces different mutex for protecting
> > sysctl parameter and locks it in proc_kprobes_optimization_handler.
> > Of course, since we need to lock kprobe_mutex when touching kprobes
> > resources, that is done in *optimize_all_kprobes().
> > 
> > This bug was from ad72b3bea744b4db01c89af0f86f3e8920d354df
> > 
> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: Tejun Heo <tj@kernel.org>
> > Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> > Cc: "David S. Miller" <davem@davemloft.net>
> 
> Oops,
> 
> Acked-by: Tejun Heo <tj@kernel.org>

Since you pushed the original commit, mind pushing this fix to Linus too?

Thanks,

	Ingo

  reply	other threads:[~2013-04-19  7:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-18  9:33 [PATCH -tip ] [BUGFIX] kprobes: Fix a double lock bug of kprobe_mutex Masami Hiramatsu
2013-04-18 15:49 ` Ananth N Mavinakayanahalli
2013-04-18 18:17 ` Tejun Heo
2013-04-19  7:22   ` Ingo Molnar [this message]
2013-04-19  7:25     ` Ingo Molnar

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