tracing: [4.12] Allow function tracing to start earlier in boot up

I've had people ask about moving tracing up further in the boot process. This patch series looks at function tracing only. It allows for tracing (and function filtering) to be moved right after memory is initialized. To have it happen before memory initialization would require a bit more work with allocating the ring buffer. But this is a start.

I placed a hook into free_reserved_area() which is used by all archs to free the init memory. Having it pass the range being freed to ftrace lets ftrace clean up any function that is registered such that it doesn't try to modify code that no longer exists.

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: 2b87965a1e6b6051435315d3f04627a5dbad979c

Steven Rostedt (VMware) (7):
tracing: Split tracing initialization into two for early initialization
ftrace: Move ftrace_init() to right after memory initialization
tracing: Postpone tracer start-up tests till the system is more robust
ftrace: Have function tracing start in early boot up
ftrace: Allow for function tracing to record init functions on boot up
tracing: Move trace_handle_return() out of line
ftrace/x86: Do no run CPU sync when there is only one CPU online

----

 arch/x86/kernel/ftrace.c       |  8 +++-
 include/linux/ftrace.h         |  7 ++++
 include/linux/init.h           |  4 +-
 include/linux/trace_events.h   | 11 +----
 init/main.c                    |  9 +++--
 kernel/trace/ftrace.c          | 44 ++++++++++++++++++++
 kernel/trace/trace.c           | 92 +++++++++++++++++++++++++++++++++++++++++-
 kernel/trace/trace.h           |  2 +
 kernel/trace/trace_functions.c |  3 +-
 mm/page_alloc.c                |  4 ++
 scripts/recordmcount.c         |  1 +
 scripts/recordmcount.pl        |  1 +
 12 files changed, 168 insertions(+), 18 deletions(-)