Re: [PATCH] x86: Add a list for custom page fault handlers.

[Ingo Molnar <mingo@elte.hu>]

* Pekka Paalanen <pq@iki.fi> wrote:

> >  static inline int notify_page_fault(struct pt_regs *regs)
> >  {
> >  #ifdef CONFIG_KPROBES
> > @@ -588,6 +636,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
> >  	if (notify_page_fault(regs))
> >  		return;
> >  
> > +	if (handle_custom_pf(regs, error_code, address))
> > +		return;
> > +
> 
> This is the non-trivial change that I really want to test before 
> submitting again. The call site of the handlers changes, and vmalloc 
> related faults reach the custom handlers. I don't think this would be 
> a problem for mmiotrace, but I don't know enough to be sure. I guess 
> using vmalloc'd memory from a page fault handler would be doomed, 
> anyway, so no point worrying about it, right?

could you please send us a patch for the whole mmiotrace kernel-side 
feature, so that we can have a look at the general structure of this? 
(and the interaction with change_page_attr(), etc.) Even if it's not 
functional (and wont even build/boot) at the moment. Thanks,

	Ingo