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From: Kees Cook <keescook@chromium.org>
To: Joel Fernandes <joel@joelfernandes.org>
Cc: "Zhengyejian (Zetta)" <zhengyejian1@huawei.com>,
	rostedt@goodmis.org, ccross@android.com,
	linux-kernel@vger.kernel.org,
	Zhangjinhao <zhangjinhao2@huawei.com>
Subject: Re: [BUG] I found a bug when try to enable record_ftrace
Date: Wed, 9 Jun 2021 11:12:22 -0700	[thread overview]
Message-ID: <202106091110.F13B8B6@keescook> (raw)
In-Reply-To: <YL/CHEbw5L2Selfm@google.com>

On Tue, Jun 08, 2021 at 03:16:44PM -0400, Joel Fernandes wrote:
> On Wed, Jun 02, 2021 at 10:43:29AM -0700, Kees Cook wrote:
> > 
> > On Wed, Jun 02, 2021 at 03:42:23PM +0800, Zhengyejian (Zetta) wrote:
> > > Hello,
> > > 
> > > There may be a deadlock caused by ftrace recursion when try to enable
> > > record_ftrace.
> > 
> > Hi,
> > 
> > Thanks for the report. Joel, is this something you can take a look at?
> 
> Kees,
> 
> Sorry for late reply. Right now I am dealing with a production-stop bug and
> would not likely get time. Plus I feel a bit less motivated, because the
> ftrace in pstore the way it stands now is unusable due to perf issues anyway
> (I wonder if anyone uses it at all now). I would rather someone who has time
> to work on this try to revive: https://lkml.org/lkml/2020/9/2/1075 . Should
> we just delete pstore function tracing till then?

If no one is using it, then yes, let's rip it out. Zetta, are you using
pstore ftrace?

-Kees

-- 
Kees Cook

  reply	other threads:[~2021-06-09 18:12 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-02  7:42 [BUG] I found a bug when try to enable record_ftrace Zhengyejian (Zetta)
2021-06-02 13:52 ` Steven Rostedt
2021-06-02 17:43 ` Kees Cook
2021-06-08 19:16   ` Joel Fernandes
2021-06-09 18:12     ` Kees Cook [this message]
2021-06-10 17:26 ` Steven Rostedt

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