selftests: ftrace: Add a testcase for function filter glob match

Add function filter glob matching test case.
This checks whether the kernel supports glob matching
(front match, end match, middle match, side match,
character class and '?').

Here is the test result.
  -----
  ./ftracetest test.d/ftrace/func-filter-glob.tc
  === Ftrace unit tests ===
  [1] ftrace - function glob filters	[PASS]

  # of passed:  1
  # of failed:  0
  # of unresolved:  0
  # of untested:  0
  # of unsupported:  0
  # of xfailed:  0
  # of undefined(test bug):  0
  -----

Link: http://lkml.kernel.org/r/147928407589.22982.16364174511117104303.stgit@devbox

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

tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc

@@ -0,0 +1,49 @@
+#!/bin/sh
+# description: ftrace - function glob filters
+
+# Make sure that function glob matching filter works.
+
+if ! grep -q function available_tracers; then
+    echo "no function tracer configured"
+    exit_unsupported
+fi
+
+disable_tracing
+clear_trace
+
+# filter by ?, schedule is always good
+if ! echo "sch?dule" > set_ftrace_filter; then
+    # test for powerpc 64
+    if ! echo ".sch?dule" > set_ftrace_filter; then
+	fail "can not enable schedule filter"
+    fi
+    cat set_ftrace_filter | grep '^.schedule$'
+else
+    cat set_ftrace_filter | grep '^schedule$'
+fi
+
+ftrace_filter_check() { # glob grep
+  echo "$1" > set_ftrace_filter
+  cut -f1 -d" " set_ftrace_filter > $TMPDIR/actual
+  cut -f1 -d" " available_filter_functions | grep "$2" > $TMPDIR/expected
+  DIFF=`diff $TMPDIR/actual $TMPDIR/expected`
+  test -z "$DIFF"
+}
+
+# filter by *, front match
+ftrace_filter_check '*schedule' '^.*schedule$'
+
+# filter by *, middle match
+ftrace_filter_check '*schedule*' '^.*schedule.*$'
+
+# filter by *, end match
+ftrace_filter_check 'schedule*' '^schedule.*$'
+
+# filter by *, both side match
+ftrace_filter_check 'sch*ule' '^sch.*ule$'
+
+# filter by char class.
+ftrace_filter_check '[Ss]y[Ss]_*' '^[Ss]y[Ss]_.*$'
+
+echo > set_ftrace_filter
+enable_tracing