selftests/ftrace: Add more tests for removing of function probes

Al Viro discovered a bug in the removing of function probes where if it had
a '*' at the beginning, it would fail to find any matches. That is, because
it reset the glob search string to the the initial string with a "MATCH_END"
type, instead of skipping the wildcard "*" it included it, where it would
not match any functions because "*" was being treated as a normal character
and not a wildcard one.

Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc

@@ -128,6 +128,43 @@ if check_set_ftrace_filter "$FUNC1" "$FUNC2" ; then
     fail "Expected $FUNC1 and $FUNC2"
 fi
 
+test_actual() { # Compares $TMPDIR/expected with set_ftrace_filter
+    cat set_ftrace_filter | grep -v '#' | cut -d' ' -f1 | cut -d':' -f1 | sort -u > $TMPDIR/actual
+    DIFF=`diff $TMPDIR/actual $TMPDIR/expected`
+    test -z "$DIFF"
+}
+
+# Set traceoff trigger for all fuctions with "lock" in their name
+cat available_filter_functions | cut -d' ' -f1 |  grep 'lock' | sort -u > $TMPDIR/expected
+echo '*lock*:traceoff' > set_ftrace_filter
+test_actual
+
+# now remove all with 'try' in it, and end with lock
+grep -v 'try.*lock$' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!*try*lock:traceoff' >> set_ftrace_filter
+test_actual
+
+# remove all that start with "m" and end with "lock"
+grep -v '^m.*lock$' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!m*lock:traceoff' >> set_ftrace_filter
+test_actual
+
+# remove all that start with "c" and have "unlock"
+grep -v '^c.*unlock' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!c*unlock*:traceoff' >> set_ftrace_filter
+test_actual
+
+# clear all the rest
+> $TMPDIR/expected
+echo '!*:traceoff' >> set_ftrace_filter
+test_actual
+
+rm $TMPDIR/expected
+rm $TMPDIR/actual
+
 do_reset
 
 exit 0