tracing/kprobes: Add selftest scripts testing kprobe-tracer as startup test

Add two selftest scripts which tests kprobe-tracer as the startup
selftest does.
These test cases are testing that the kprobe_event can accept a
kprobe event with $stack related arguments and a kretprobe event
with $retval argument.

Link: http://lkml.kernel.org/p/20141008040307.13415.45145.stgit@kbuild-f20.novalocalSigned-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args.tc

+#!/bin/sh
+# description: Kprobe dynamic event with arguments
+
+[ -f kprobe_events ] || exit_unsupported # this is configurable
+
+echo 0 > events/enable
+echo > kprobe_events
+echo 'p:testprobe do_fork $stack $stack0 +0($stack)' > kprobe_events
+grep testprobe kprobe_events
+test -d events/kprobes/testprobe
+echo 1 > events/kprobes/testprobe/enable
+( echo "forked")
+echo 0 > events/kprobes/testprobe/enable
+echo "-:testprobe" >> kprobe_events
+test -d events/kprobes/testprobe && exit 1 || exit 0
+

tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_args.tc

+#!/bin/sh
+# description: Kretprobe dynamic event with arguments
+
+[ -f kprobe_events ] || exit_unsupported # this is configurable
+
+echo 0 > events/enable
+echo > kprobe_events
+echo 'r:testprobe2 do_fork $retval' > kprobe_events
+grep testprobe2 kprobe_events
+test -d events/kprobes/testprobe2
+echo 1 > events/kprobes/testprobe2/enable
+( echo "forked")
+echo 0 > events/kprobes/testprobe2/enable
+echo '-:testprobe2' >> kprobe_events
+test -d events/kprobes/testprobe2 && exit 1 || exit 0