From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Venkat Subbiah <venkat.mlist@gmail.com>, linux-rt-users@vger.kernel.org
Subject: Re: Enabling function trace on call during module init
Date: Fri, 11 Oct 2013 12:15:31 +0200 [thread overview]
Message-ID: <20131011101531.GD6983@linutronix.de> (raw)
In-Reply-To: <20130907204811.5d52a6b1@gandalf.local.home>
* Steven Rostedt | 2013-09-07 20:48:11 [-0400]:
>You wont be able to trace any function that is annotated with "__init",
>or even "__exit". That's because the init section does not have a
>standard way of cleaning them up (for boot, modules are different, but
>are still affected by it).
Is this even required / wanted? Usually the module just hooks itself
into subsystem like pci_register_driver() and is usually not
interresting. The interresting part starts from ->probe() (I think) and
this is captured, right?
>As ftrace modifies code, and it modifies locations of functions, it can
>not safely modify code that suddenly disappeared without it knowing it,
>otherwise you may end up with broken NIC cards.
Hmmm. This sounds like you know what you are talking about :)
>-- Steve
Sebastian
next prev parent reply other threads:[~2013-10-11 10:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-07 3:55 Enabling function trace on call during module init Venkat Subbiah
2013-09-08 0:48 ` Steven Rostedt
2013-09-14 3:59 ` Venkat Subbiah
2013-10-11 10:15 ` Sebastian Andrzej Siewior [this message]
2013-10-11 12:35 ` Steven Rostedt
2013-10-11 13:02 ` Sebastian Andrzej Siewior
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