From: Jiri Olsa <jolsa@redhat.com>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Peter Zijlstra <peterz@infradead.org>,
lkml <linux-kernel@vger.kernel.org>,
"bibo,mao" <bibo.mao@intel.com>,
"Ziqian SUN (Zamir)" <zsun@redhat.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] kretprobe: Prevent triggering kretprobe from within kprobe_flush_task
Date: Thu, 16 Apr 2020 11:13:20 +0200 [thread overview]
Message-ID: <20200416091320.GA322899@krava> (raw)
In-Reply-To: <20200416105506.904b7847a1b621b75463076d@kernel.org>
On Thu, Apr 16, 2020 at 10:55:06AM +0900, Masami Hiramatsu wrote:
SNIP
> > trampoline_handler
> > kretprobe_hash_lock(current, &head, &flags); <--- deadlock
> >
> > Adding kprobe_busy_begin/end helpers that mark code with fake
> > probe installed to prevent triggering of another kprobe within
> > this code.
> >
> > Using these helpers in kprobe_flush_task, so the probe recursion
> > protection check is hit and the probe is never set to prevent
> > above lockup.
> >
> > Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
>
> Thanks Jiri and Ziqian!
>
> Looks good to me.
>
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
>
> BTW, this is a kind of bugfix. So should it add a Fixes tag?
>
> Fixes: ef53d9c5e4da ('kprobes: improve kretprobe scalability with hashed locking')
> Cc: stable@vger.kernel.org
ah right, do you want me to repost with those?
thanks,
jirka
next prev parent reply other threads:[~2020-04-16 9:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 16:46 [RFC] kretprobe: Prevent triggering kretprobe from within kprobe_flush_task Jiri Olsa
2020-04-09 9:02 ` Naveen N. Rao
2020-04-09 18:43 ` Jiri Olsa
2020-04-09 12:38 ` Masami Hiramatsu
2020-04-09 12:52 ` Jiri Olsa
2020-04-09 14:16 ` Masami Hiramatsu
2020-04-09 13:16 ` Naveen N. Rao
2020-04-09 14:26 ` Masami Hiramatsu
2020-04-09 14:41 ` Masami Hiramatsu
2020-04-09 18:44 ` Jiri Olsa
2020-04-09 20:13 ` Jiri Olsa
2020-04-10 0:31 ` Masami Hiramatsu
2020-04-14 16:03 ` Jiri Olsa
2020-04-15 9:05 ` [PATCH] " Jiri Olsa
2020-04-16 1:55 ` Masami Hiramatsu
2020-04-16 9:13 ` Jiri Olsa [this message]
2020-04-16 13:42 ` Masami Hiramatsu
2020-04-16 14:31 ` [PATCHv2] " Jiri Olsa
2020-04-17 7:38 ` Masami Hiramatsu
2020-04-28 21:36 ` Jiri Olsa
2020-05-01 2:01 ` Masami Hiramatsu
2020-05-07 10:15 ` Jiri Olsa
2020-04-10 1:31 ` [RFC] " Ziqian SUN (Zamir)
2020-04-14 16:03 ` Jiri Olsa
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