selftests/ftrace: Add a testcase for kprobe event naming

Add a testcase for kprobe event naming. This testcase checks whether the
kprobe events can automatically ganerate its event name on normal
function and dot-suffixed function.  Also it checks whether the kprobe
events can correctly define new event with given event name and group
name.

Link: http://lkml.kernel.org/r/61ae96fd1fcd14ee652c8b6525c218b8661bb0d2.1499453040.git.naveen.n.rao@linux.vnet.ibm.comSigned-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[Updated tests to use vfs_read and symbols with '.isra.',
added check for kprobe_events and a command to clear it on exit,
various additional checks and tests]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

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

+#!/bin/sh
+# description: Kprobe event auto/manual naming
+
+[ -f kprobe_events ] || exit_unsupported # this is configurable
+
+disable_events
+echo > kprobe_events
+
+:;: "Add an event on function without name" ;:
+
+FUNC=`grep " [tT] .*vfs_read$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
+[ "x" != "x$FUNC" ] || exit_unresolved
+echo "p $FUNC" > kprobe_events
+PROBE_NAME=`echo $FUNC | tr ".:" "_"`
+test -d events/kprobes/p_${PROBE_NAME}_0 || exit_failure
+
+:;: "Add an event on function with new name" ;:
+
+echo "p:event1 $FUNC" > kprobe_events
+test -d events/kprobes/event1 || exit_failure
+
+:;: "Add an event on function with new name and group" ;:
+
+echo "p:kprobes2/event2 $FUNC" > kprobe_events
+test -d events/kprobes2/event2 || exit_failure
+
+:;: "Add an event on dot function without name" ;:
+
+FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
+[ "x" != "x$FUNC" ] || exit_unresolved
+echo "p $FUNC" > kprobe_events
+EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`
+[ "x" != "x$EVENT" ] || exit_failure
+test -d events/$EVENT || exit_failure
+
+echo > kprobe_events