process return probes not available with inode-based uprobes

[Frank Ch. Eigler]

agentzh <agentzh@gmail.com> writes:

> I'm trying systemtap 1.8 (from yum) and 2.0-14916 (from git) on Fedora
> 17 and I'm getting the following error when trying to specify a
> user-space function return probe:
> [...] 
> process("nginx").function("ngx_http_lua_process_args_option").return {...}
> semantic error: process return probes not available with inode-based uprobes

kernel folks are working toward restoring this functionality we are
used to from the utrace+uprobes days.  I don't remember seeing any
patches posted to LKML yet, which suggests having to wait till
linux-3.7 or longer.

OTOH, with more systemtap-side work, we may be able to approximate 
it with http://sourceware.org/PR10056, http://sourceware.org/PR4413.


- FChE