[PATCH RFC 2/6] arm64: Kprobes with single stepping support

Steven Rostedt rostedt at goodmis.org
Tue Nov 12 11:59:35 EST 2013


On Tue, 12 Nov 2013 16:25:26 +0530
Sandeepa Prabhu <sandeepa.prabhu at linaro.org> wrote:


> >
> > BTW, I'm currently trying a general housecleaning of __kprobes
> > annotations. It may also have impact on your patch.
> > https://lkml.org/lkml/2013/11/8/187
> Hmm, we can help testing your patchset on arm64 platforms. Also have
> many doubts on the changes you are working [blacklisting probes etc]
> 
> Basically I had tried placing kprobe on memcpy() and the model hung
> (insmod never returned back!). Fast-model I have does not have option
> of any debug so no clue what happened!.
> memcpy() is low-level call being used internally within kprobes, so
> probably we cannot handle probe on that routine, but then how to make
> sure all such API are rejected by kprobe sub-system ?

Working on ports of ftrace, I found that many of the functions in lib/
are used by several locations that just can't be traced, due to how
low level they are. I just simply blacklisted the entire lib/
directory (See the top of lib/Makefile)

I wonder if there's an easy way to blacklist entire directories from
being used by kprobes too. Or at least do it by a file per file basis.

-- Steve



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