[RFC PATCH] Fix segmentation fault of listing kprocess.create

[Wenji Huang]

Hi,

Sorry for a little annoying thread. ^-^
> Please ignore the previous patch, the root cause is the 
> following section
> tapsets.cxx: dwarf_derived_probe::saveargs
> 
>          /* trick from visit_target_symbol_context */
>          target_symbol *tsym = new target_symbol;
>          token *t = new token;
>          tsym->tok = t;
>          tsym->base_name = "$";
>          tsym->base_name += arg_name;
> 
> The empty token is created, I will fix it soon. 
> Also any suggestion is welcome!
> 
Take a deep look. Seems we will try to access the variables in
return probe. It's fully supported or not? Guess not.

If not, the function should return early once has_return is true.
If yes, we will hypothesize accessing the argument. And the
source_loc of t has to be q.base_loc since no real one.

Regards,
Wenji