selftests/ftrace: Add ftrace cpumask testcase

Add a testcase for tracing_cpumask with function tracer.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

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

+#!/bin/sh
+# SPDX-License-Identifier: GPL2.0
+# description: ftrace - function trace with cpumask
+
+if ! which nproc ; then
+  nproc() {
+    ls -d /sys/devices/system/cpu/cpu[0-9]* | wc -l
+  }
+fi
+
+NP=`nproc`
+
+if [ $NP -eq 1 ] ;then
+  echo "We can not test cpumask on UP environment"
+  exit_unresolved
+fi
+
+ORIG_CPUMASK=`cat tracing_cpumask`
+
+do_reset() {
+  echo $ORIG_CPUMASK > tracing_cpumask
+}
+
+echo 0 > tracing_on
+echo > trace
+: "Bitmask only record on CPU1"
+echo 2 > tracing_cpumask
+MASK=0x`cat tracing_cpumask`
+test `printf "%d" $MASK` -eq 2 || do_reset
+
+echo function > current_tracer
+echo 1 > tracing_on
+(echo "forked")
+echo 0 > tracing_on
+
+: "Check CPU1 events are recorded"
+grep -q -e "\[001\]" trace || do_reset
+
+: "There should be No other cpu events"
+! grep -qv -e "\[001\]" -e "^#" trace || do_reset
+
+do_reset