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From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	Sandeepa Prabhu <sandeepa.prabhu@linaro.org>,
	x86@kernel.org, lkml <linux-kernel@vger.kernel.org>,
	"Steven Rostedt (Red Hat)" <rostedt@goodmis.org>,
	systemtap@sourceware.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: Re: Re: [PATCH -tip v4 0/6] kprobes: introduce NOKPROBE_SYMBOL() and fixes crash bugs
Date: Fri, 13 Dec 2013 15:06:06 +0900	[thread overview]
Message-ID: <52AAA3CE.9010301@hitachi.com> (raw)
In-Reply-To: <52AA9C55.1000103@hitachi.com>

(2013/12/13 14:34), Masami Hiramatsu wrote:
>> Lets assume we allow a probe to be inserted in the single-step path. 
>> Such a probe will be an INT3 instruction and if it hits we get a 
>> recursive INT3 invocation. In that case the INT3 handler should simply
>> restore the original instruction and _leave it so_. There's no 
>> single-stepping needed - the probe is confused and must be discarded.
> 
> But how can we restore the protected kernel text?
> If we use text_poke, we also need to prohibit probing on the text_poke
> and functions called in the text_poke too. That just shifts the annotated
> area to the text_poke. :(

BTW, currently we mark the text_poke as nokprobe_symbol, but it should be
removed. We don't call it from kprobes int3/debug handlers.

The patches which removes __kprobes in this series are only for kprobe
related files (arch/x86/kernel/kprobes/* or kernel/kprobes.c.) I think
we should do it for other parts.
Is it better to do that on this series?

Thank you,

-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com



  reply	other threads:[~2013-12-13  6:06 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-04  1:28 [PATCH -tip v4 0/6] kprobes: introduce NOKPROBE_SYMBOL() and fixes crash bugs Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 1/6] kprobes: Prohibit probing on .entry.text code Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 2/6] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 3/6] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 4/6] [BUGFIX] x86: Prohibit probing on native_set_debugreg Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 5/6] [BUGFIX] x86: Prohibit probing on thunk functions and restore Masami Hiramatsu
2013-12-04  1:28 ` [PATCH -tip v4 6/6] [RFC] kprobes/x86: Call exception handlers directly from do_int3/do_debug Masami Hiramatsu
2013-12-04  2:39   ` Steven Rostedt
2013-12-11 13:31     ` Jiri Kosina
2013-12-12  4:40       ` Masami Hiramatsu
2013-12-12  9:59         ` Jiri Kosina
2013-12-12 10:31           ` Masami Hiramatsu
2013-12-04  2:54 ` [PATCH -tip v4 0/6] kprobes: introduce NOKPROBE_SYMBOL() and fixes crash bugs Sandeepa Prabhu
2013-12-04  7:39   ` Masami Hiramatsu
2013-12-04  8:46     ` Sandeepa Prabhu
2013-12-04 23:32       ` Masami Hiramatsu
2013-12-04  8:45 ` Ingo Molnar
2013-12-04 23:27   ` Masami Hiramatsu
2013-12-05 10:21     ` Ingo Molnar
2013-12-06  2:34       ` Masami Hiramatsu
2013-12-10 15:28         ` Ingo Molnar
2013-12-11  2:12           ` Masami Hiramatsu
2013-12-11 13:34             ` Ingo Molnar
2013-12-12  6:02               ` Masami Hiramatsu
2013-12-12 14:03                 ` Ingo Molnar
2013-12-12 20:42                   ` Josh Stone
2013-12-13  5:34                   ` Masami Hiramatsu
2013-12-13  6:06                     ` Masami Hiramatsu [this message]
2013-12-16 10:53                     ` Masami Hiramatsu
2013-12-05 13:08     ` Sandeepa Prabhu
2013-12-06  6:23       ` Masami Hiramatsu
2013-12-06  6:54         ` Sandeepa Prabhu
2013-12-06 23:25           ` Masami Hiramatsu
2013-12-05 14:49     ` Frank Ch. Eigler
2013-12-06  6:12       ` Masami Hiramatsu
2013-12-06 19:07         ` Frank Ch. Eigler
2013-12-06 23:19           ` Masami Hiramatsu
2013-12-07  1:32             ` Frank Ch. Eigler
2013-12-07  2:34               ` Masami Hiramatsu

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