selftests/ftrace: Add kprobe profile testcase

Add a testcase for testing kprobe_profile interface
which provides per-kprobe event hit/misshit counts.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

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

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Kprobe dynamic event - adding and removing
+
+[ -f kprobe_events ] || exit_unsupported # this is configurable
+
+! grep -q 'myevent' kprobe_profile
+echo p:myevent _do_fork > kprobe_events
+grep -q 'myevent[[:space:]]*0[[:space:]]*0$' kprobe_profile
+echo 1 > events/kprobes/myevent/enable
+( echo "forked" )
+grep -q 'myevent[[:space:]]*[[:digit:]]*[[:space:]]*0$' kprobe_profile
+echo 0 > events/kprobes/myevent/enable
+echo > kprobe_events
+! grep -q 'myevent' kprobe_profile