tracing: Add kprobe-based event tracer

Add kprobes-based event tracer on ftrace.

This tracer is similar to the events tracer which is based on Tracepoint
infrastructure. Instead of Tracepoint, this tracer is based on kprobes
(kprobe and kretprobe). It probes anywhere where kprobes can probe(this
 means, all functions body except for __kprobes functions).

Similar to the events tracer, this tracer doesn't need to be activated
via current_tracer, instead of that, just set probe points via
/sys/kernel/debug/tracing/kprobe_events. And you can set filters on each
probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter.

This tracer supports following probe arguments for each probe.

  %REG  : Fetch register REG
  sN    : Fetch Nth entry of stack (N >= 0)
  sa    : Fetch stack address.
  @ADDR : Fetch memory at ADDR (ADDR should be in kernel)
  @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
  aN    : Fetch function argument. (N >= 0)
  rv    : Fetch return value.
  ra    : Fetch return address.
  +|-offs(FETCHARG) : fetch memory at FETCHARG +|- offs address.

See Documentation/trace/kprobetrace.txt in the next patch for details.

Changes from v13:
 - Support 'sa' for stack address.
 - Use call->data instead of container_of() macro.

[[email protected]: Fixed conflict against latest tracing/core]

Signed-off-by: Masami Hiramatsu <[email protected]>
Acked-by: Ananth N Mavinakayanahalli <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Frank Ch. Eigler <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Jim Keniston <[email protected]>
Cc: K.Prasad <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Przemysław Pawełczyk <[email protected]>
Cc: Roland McGrath <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Vegard Nossum <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>

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