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From: Abhishek Sagar <sagar.abhishek@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 0/4] ftrace: prevent ftrace modifications while being kprobe'd
Date: Sat, 21 Jun 2008 23:47:15 +0530	[thread overview]
Message-ID: <485D45AB.3000405@gmail.com> (raw)

Hi Steven/Ingo,

These patches address the problem of kprobe registration interfering with
dynamic ftrace. A kprobe registered on an mcount call-site can modify that
address multiple times during its duration of probing. At the same time,
ftrace may simultaneously modify these locations. This could be fatal
especially if ftrace modifies the call-site during a kprobe registration
on it (between arch_prepare_kprobe and arch_arm_kprobe in __register_kprobe
to be more precise). So as a "fix", I've disabled any updates on the mcount
call-site while it's being kprobe'd.

--
Regards,
Abhishek Sagar

             reply	other threads:[~2008-06-21 18:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-21 18:17 Abhishek Sagar [this message]
2008-06-23 20:15 ` [PATCH 0/4] ftrace: prevent ftrace modifications while being kprobe'd Ingo Molnar
2008-06-24  3:29   ` Abhishek Sagar
2008-06-26 12:33     ` Ingo Molnar
2008-06-26 17:21       ` Abhishek Sagar
2008-07-03 12:49         ` Ingo Molnar

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