[RFC PATCH 0/5] tracing: Unifying dynamic event interface

[Masami Hiramatsu <mhiramat@kernel.org>]

Hi,

This is an RFC series of unifying dynamic event interface on ftrace.
Currently ftrace has 3 dynamic event interfaces, kprobes, uprobes
and synthetic. This series unifies kprobes and uprobes event
interface on "dynamic_events". This enables us to add new dynamic
events easily on same interface, e.g. function events.
The older interfaces are left on the tracefs for backward
compatibility at this moment.

dynamic_events syntax has no different from kprobe_events and
uprobe_events. You can use same syntax for dynamic_events interface.

I think we can integrate synthetic events to this dynamic_events
interface but it will requires new syntax. e.g.

echo "s:<event-name> <args>" >> dynamic_events

If it is OK, I'll add it in next version.

BTW, since this dynamic_events interface derived from *probe_events,
it inherits "all clear when truncate file open" behavior. But if you
think this is too aggressive, I can drop it. (even in that case,
kprobe_events/uprobe_events behavior is not changed)

I also introduced a widely used way to erase entries in other
interfaces of ftrace, that is '!'. So you can now use '!event-name'
or '!group/event' to erase an entry in dynamic_events.
(Wait... it has to be '!p:event' as others do??)

Any thought?

Thank you,

---

Masami Hiramatsu (5):
      tracing/uprobes: Add busy check when cleanup all uprobes
      tracing: Add a unified dynamic event framework
      tracing/kprobes: Use dyn_event framework for kprobe events
      tracing/uprobes: Use dyn_event framework for uprobe events
      tracing: Add generic event-name based remove event method


 Documentation/trace/kprobetrace.rst  |    3 +
 Documentation/trace/uprobetracer.rst |    4 +
 kernel/trace/Kconfig                 |    4 +
 kernel/trace/Makefile                |    1 
 kernel/trace/trace.c                 |    4 +
 kernel/trace/trace_dynevent.c        |  183 +++++++++++++++++++++++++++++++++
 kernel/trace/trace_dynevent.h        |   89 ++++++++++++++++
 kernel/trace/trace_kprobe.c          |  191 +++++++++++++++++++++++-----------
 kernel/trace/trace_uprobe.c          |  175 +++++++++++++++++++++++--------
 9 files changed, 547 insertions(+), 107 deletions(-)
 create mode 100644 kernel/trace/trace_dynevent.c
 create mode 100644 kernel/trace/trace_dynevent.h

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>