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Re: __kbrobes?
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Jun Koi <junkoi2004 at gmail dot com>
- Cc: SystemTAP <systemtap at sources dot redhat dot com>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Jim Keniston <jkenisto at us dot ibm dot com>
- Date: Wed, 30 Jul 2008 11:15:05 -0400
- Subject: Re: __kbrobes?
- References: <fdaac4d50807300359m329b6ff1k6ec2e2b1c56aab24@mail.gmail.com>
Hi Jun,
Jun Koi wrote:
> Hi,
>
> I found some functions use __kprobes as directive (like text_poke()).
> Closer look points out that it is used to collect them into a section
> ".kprobes.text". What do we have to do with that? Is that because we
> dont want to probe those areas?
The __kprobes means that those functions are invoked from kprobe itself.
And kprobes doesn't accept to probe at the addresses in ".kprobes.text"
sectoin for preventing recursive-call of kprobes.
>
> If so, why do we want to protect text_poke() against kprobes?
Indeed. text_poke() seems not to be invoked from kprobes probing
functions. It is used only for disarming/arming breakpoints from
registering/disabling kprobes.
Thank you,
>
> Many thanks,
> Jun
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com