Re: [PATCH 0/2] kprobe: Fix: add symbols to kprobe blacklist

From: Steven Rostedt
Date: Fri Jul 14 2017 - 14:28:05 EST


On Fri, 14 Jul 2017 10:58:33 -0400
Francis Deslauriers <francis.deslauriers@xxxxxxxxxxxx> wrote:


> Kretprobe on ftrace_ops_assist_func and another function:
> Those crashes are triggered when hooking a kretprobe on the
> ftrace_ops_assist_func symbol and some other functions to make the this first
> function reacheable. From my understanding, ftrace_ops_assist_func is the
> function called directly when the kprobe is hit. Thus it should be marked
> with NOKPROBE_SYMBOL.
>

Hmm, I'm wondering if I should just make an ftrace section, and black
list the entire thing. Also that section could be used to not allow
ftrace to use it either. I've been wanting to start letting ftrace
trace the tracing code, and perf for that matter. It would be nice to
be able to debug things like that.

I would like to also make sections that can be enabled or disabled in
groups. To group things like the tracing facility and perf and have
them by default not be traced, but then set a flag that says "sure go
ahead and trace them". This shouldn't be too hard to do.

Hmm, I'll add this as another topic to have for the Linux Plumbers
tracing track, as well as the kernel tracing topic.

-- Steve