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Date: Wed, 6 Nov 2013 12:50:04 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
        Ananth N Mavinakayanahalli <ananth@in.ibm.com>, x86@kernel.org,
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        Andrew Morton <akpm@linux-foundation.org>,
        Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH -tip v2 3/3] [BUGFIX] kprobes: Prohibit probing on
 func_ptr_is_kernel_text
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* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2013/11/06 15:07), Ingo Molnar wrote:
> > 
> > * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> > 
> >>>> [...] I hope to build the list when the kernel build time if 
> >>>> possible... Would you have any idea to classify some annotated(but no 
> >>>> side-effect) functions?
> >>>
> >>> The macro magic I can think of would need to change the syntax of the 
> >>> function definition - for example that is how the SYSCALL_DEFINE*() 
> >>> macros work.
> >>
> >> Would you mean something like the below macro? :)
> >>
> >> NOKPROBE_SYMBOL(int, func_ptr_is_kernel_text)(void *ptr)
> > 
> > I think this is rather ugly and harder to maintain. The whole _point_ of 
> > such annotations is to make them 'easy on the eyes', to make it easy to 
> > skip a 'noinline', 'noprobe' or 'notrace' tag.
> > 
> > Using something like NOKPROBE_SYMBOL() makes the whole construct ugly and 
> > attention seeking.
> 
> Hmm, by the way how about Steven's idea? A macro like EXPORT_SYMBOL? At 
> least for kprobes_blacklist, which is defined/maintained in kprobes.c 
> for some symbols(*), that is useful for updating it because we can put 
> it near the function definition.

Dunno, it feels a bit fragile to me.

Thanks,

	Ingo