selftests/ftrace: Improve kprobe testcase to check log data

Improve kprobe testcase to check the log data correctness
and ensure the event definition is corrctly including
argument definition.
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/kprobe_args.tc

@@ -5,10 +5,14 @@
 [ -f kprobe_events ] || exit_unsupported # this is configurable
 
 echo 'p:testprobe _do_fork $stack $stack0 +0($stack)' > kprobe_events
-grep testprobe kprobe_events
+grep testprobe kprobe_events | grep -q 'arg1=\$stack arg2=\$stack0 arg3=+0(\$stack)'
 test -d events/kprobes/testprobe
+
 echo 1 > events/kprobes/testprobe/enable
 ( echo "forked")
+grep testprobe trace | grep '_do_fork' | \
+  grep -q 'arg1=0x[[:xdigit:]]* arg2=0x[[:xdigit:]]* arg3=0x[[:xdigit:]]*$'
+
 echo 0 > events/kprobes/testprobe/enable
 echo "-:testprobe" >> kprobe_events
 clear_trace