This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
Re: can kprobes be modular?
- From: Jim Keniston <jkenisto at us dot ibm dot com>
- To: Roland McGrath <roland at redhat dot com>
- Cc: SystemTAP <systemtap at sources dot redhat dot com>
- Date: 27 Feb 2007 10:44:20 -0800
- Subject: Re: can kprobes be modular?
- Organization:
- References: <20070227021039.7CEFB180067@magilla.sf.frob.com>
On Mon, 2007-02-26 at 18:10, Roland McGrath wrote:
> I was reading over some things, and it occurred to me that kprobes ought to
> be a loadable kernel module. I don't have any special motivation for this.
> It just seems like an unclean situation that it can't be a module now.
> Perhaps many kernels will want to build it in anyway, but I can't see why
> it isn't a module. It's not very big, but neither are many other things
> that are used much more often and are built as modules.
>
> The #ifdef CONFIG_KPROBES sections in e.g. arch/i386/kernel/traps.c look to
> me like things that ought to be enabled unconditionally, so kprobes or any
> other module could use them. Things like register_page_fault_notifier
> ought to just be enabled and exported by default.
>
> Thoughts?
Well, there's at least one call to kprobes from deep in the kernel:
finish_task_switch() calls kprobe_flush_task().
There may be other gotchas. As far as I know, nobody has investigated
the idea for quite a while.
Jim
>
>
> Thanks,
> Roland