Commit 604e3548 authored Mar 22, 2019 by Steven Rostedt (VMware)

selftests/ftrace: Select an existing function in kprobe_eventname test

Running the ftrace selftests on the latest kernel caused the
kprobe_eventname test to fail. It was due to the test that searches for
a function with at "dot" in the name and adding a probe to that.
Unfortunately, for this test, it picked:

 optimize_nops.isra.2.cold.4

Which happens to be marked as "__init", which means it no longer exists
in the kernel! (kallsyms keeps those function names around for tracing
purposes)

As only functions that still exist are in the
available_filter_functions file, as they are removed when the functions
are freed at boot or module exit, have the test search for a function
with ".isra." in the name as well as being in the
available_filter_functions (if the file exists).

Link: http://lkml.kernel.org/r/20190322150923.1b58eca5@gandalf.local.home



Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent d59fae6f

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

+15 −1

Original line number	Diff line number	Diff line
		@@ -24,7 +24,21 @@ test -d events/kprobes2/event2 \|\| exit_failure

		:;: "Add an event on dot function without name" ;:

		FUNC=`grep -m 10 " [tT] .\.isra\..$" /proc/kallsyms \| tail -n 1 \| cut -f 3 -d " "`
		find_dot_func() {
		if [ ! -f available_filter_functions ]; then
		grep -m 10 " [tT] .\.isra\..$" /proc/kallsyms \| tail -n 1 \| cut -f 3 -d " "
		return;
		fi

		grep " [tT] .\.isra\.." /proc/kallsyms \| cut -f 3 -d " " \| while read f; do
		if grep -s $f available_filter_functions; then
		echo $f
		break
		fi
		done
		}

		FUNC=`find_dot_func \| tail -n 1`
		[ "x" != "x$FUNC" ] \|\| exit_unresolved
		echo "p $FUNC" > kprobe_events
		EVENT=`grep $FUNC kprobe_events \| cut -f 1 -d " " \| cut -f 2 -d:`