[RFC][PATCH 0/4 v4] ftrace/kprobes: Setting up ftrace for kprobes

[Steven Rostedt <rostedt@goodmis.org>]

I'm only posting patches that changed from v3. Those changes include:

Saving the flags after MCOUNT_RESTORE_FRAME (suggested by Masami)
I decided to restore flags from the pt_regs, such that a kprobe
could change the flags register.

I added the offset fix for function parent pointer (pointed out by
 Alexander van Heukelum).

I fixed the i386 version of "save regs" to restore flags correctly
(as pointed out by Masami Hiramatsu).

I also added two new patches.

1) I removed the double check to function_trace_stop variable that
   the function graph tracer was doing (it tested it in the function
   tracer trampoline, and again in the function graph trampoline).

2) I added internal recursion protection, that I found kprobes was
  triggering. This was long overdue anyway.

Masami,

Could you give your reviewed by tags for the first two patches, at least.

Thanks,

-- Steve

Steven Rostedt (4):
      ftrace/x86: Add separate function to save regs
      ftrace/x86: Add save_regs for i386 function calls
      ftrace/x86: Remove function_trace_stop check from graph caller
      ftrace/x86_64: Add recursion protection inside mcount caller

----
 arch/x86/include/asm/ftrace.h |   47 +++++++++-------
 arch/x86/kernel/entry_32.S    |   93 ++++++++++++++++++++++++++++--
 arch/x86/kernel/entry_64.S    |  125 ++++++++++++++++++++++++++++++++++++-----
 arch/x86/kernel/ftrace.c      |   80 ++++++++++++++++++++++++--
 include/linux/ftrace.h        |  109 ++++++++++++++++++++++++++++++++---
 kernel/trace/ftrace.c         |   91 +++++++++++++++++++++++++++---
 6 files changed, 485 insertions(+), 60 deletions(-)