From: Nam Cao <namcao@linutronix.de>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
naveen@kernel.org, anil.s.keshavamurthy@intel.com,
davem@davemloft.net, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, john.ogness@linutronix.de
Subject: Re: kprobe on local function
Date: Wed, 29 Jan 2025 13:41:25 +0700 [thread overview]
Message-ID: <20250129063916.07WPgeQD@linutronix.de> (raw)
In-Reply-To: <20250125011655.449075f32f50de6fa7ff20b8@kernel.org>
On Sat, Jan 25, 2025 at 01:16:55AM +0900, Masami Hiramatsu wrote:
> Now what you could know is that the kernel does not call the
> "rt_mutex_slowunlock" symbol and it may call another copied symbol. That's
> a good to know right?
>
> Note that this in-kernel kretprobe API is a low-layer API, so that user is
> responsible for controlling it carefully. This kretprobe API itself does NOT
> know which copy of the optimized symbols are used.
> (there could be inlined instance too)
>
> If you need to know how many copies are generated or inlined, you need to
> use the debuginfo as "perf probe" tool does, which can not handled by the
> kernel itself because it is too big to be loaded. That is why I made the
> "perf probe" as an external tool.
Got it, thanks so much for the information!
Best regards,
Nam
prev parent reply other threads:[~2025-01-29 6:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-22 7:59 kprobe on local function Nam Cao
2025-01-22 22:29 ` Steven Rostedt
2025-01-23 1:48 ` Masami Hiramatsu
2025-01-23 2:42 ` Nam Cao
2025-01-23 2:48 ` Steven Rostedt
2025-01-24 16:16 ` Masami Hiramatsu
2025-01-29 6:41 ` Nam Cao [this message]
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