Bug 10994

Summary:	utrace-free task_finder
Product:	systemtap	Reporter:	Frank Ch. Eigler <fche>
Component:	runtime	Assignee:	David Smith <dsmith>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	P2
Version:	unspecified
Target Milestone:	---
Host:		Target:
Build:		Last reconfirmed:
Bug Depends on:	13146
Bug Blocks:

Description Frank Ch. Eigler 2009-11-20 19:52:21 UTC

With recent kernel tracepoints for mmap/process tracking, as used
by the perf tool, we may be able to use a non-utrace backend for
the task_finder.  That in turn could enable utrace-free user-space
<sdt.h> probing, using the kprobe or similar non-utrace backend.

Comment 1 David Smith 2011-12-01 16:20:08 UTC

As of commit c0f710f991 (which merged the dsmith/task_finder2 branch into the master branch), there is a non-utrace backend for the task_finder for kernels without utrace.

A kernel must support specific tracepoints (CONFIG_TRACEPOINTS) for this to work:

- sched_process_fork
- sched_process_exit
- sys_enter
- sys_exit

and one of the following:

- the not quite upstream 'sched_process_exec' tracepoint; or
- the ftrace_set_filter() function (which depends on CONFIG_FTRACE)