linux-kernel - Re: [PATCH 0/3][RFC] x86: Catch stray non-kprobe breakpoints

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Date:	Tue, 29 Jan 2008 10:13:21 -0500
From:	Masami Hiramatsu <mhiramat@...hat.com>
To:	Abhishek Sagar <sagar.abhishek@...il.com>
CC:	ananth@...ibm.com, LKML <linux-kernel@...r.kernel.org>,
	jkenisto@...ibm.com, Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH 0/3][RFC] x86: Catch stray non-kprobe breakpoints

Abhishek Sagar wrote:
> Placing a breakpoint on kprobe_handler (say) can loop into a recursive
> trap without allowing the debugger's notifier chain to be invoked. I'm
> assuming that non-kprobe exception notifiers may (or even should) run
> after kprobe's notifier callback (kprobe_exceptions_notify).

In that case, why don't you just reduce the priority of kprobe_exceptions_nb?
Then, the execution path becomes very simple.

int3 (non-kprobe) -> do_int3 -> non-krpobe/debugger

I also like to use a debugger for debugging kprobes. that will help us.

Best Regards,

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@...hat.com

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