tracing/selftest: Add selftests to test trace_marker histogram triggers

Add a couple of tests that test the trace_marker histogram triggers.
One does a straight histogram test, the other will create a synthetic event
and test the latency between two different writes (using filters to
differentiate between them).
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-hist.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: trace_marker trigger - test histogram trigger
+# flags: instance
+
+do_reset() {
+    reset_trigger
+    echo > set_event
+    clear_trace
+}
+
+fail() { #msg
+    do_reset
+    echo $1
+    exit_fail
+}
+
+if [ ! -f set_event ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+if [ ! -d events/ftrace/print ]; then
+    echo "event trace_marker is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f events/ftrace/print/trigger ]; then
+    echo "event trigger is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f events/ftrace/print/hist ]; then
+    echo "hist trigger is not supported"
+    exit_unsupported
+fi
+
+do_reset
+
+echo "Test histogram trace_marker tigger"
+
+echo 'hist:keys=common_pid' > events/ftrace/print/trigger
+for i in `seq 1 10` ; do echo "hello" > trace_marker; done
+grep 'hitcount: *10$' events/ftrace/print/hist > /dev/null || \
+    fail "hist trigger did not trigger correct times on trace_marker"
+
+do_reset
+
+exit 0

tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: trace_marker trigger - test histogram with synthetic event
+# flags:
+
+do_reset() {
+    reset_trigger
+    echo > set_event
+    echo > synthetic_events
+    clear_trace
+}
+
+fail() { #msg
+    do_reset
+    echo $1
+    exit_fail
+}
+
+if [ ! -f set_event ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+    echo "synthetic events not supported"
+    exit_unsupported
+fi
+
+if [ ! -d events/ftrace/print ]; then
+    echo "event trace_marker is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f events/ftrace/print/trigger ]; then
+    echo "event trigger is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f events/ftrace/print/hist ]; then
+    echo "hist trigger is not supported"
+    exit_unsupported
+fi
+
+do_reset
+
+echo "Test histogram trace_marker to trace_marker latency histogram trigger"
+
+echo 'latency u64 lat' > synthetic_events
+echo 'hist:keys=common_pid:ts0=common_timestamp.usecs if buf == "start"' > events/ftrace/print/trigger
+echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(ftrace.print).latency($lat) if buf == "end"' >> events/ftrace/print/trigger
+echo 'hist:keys=common_pid,lat:sort=lat' > events/synthetic/latency/trigger
+echo -n "start" > trace_marker
+echo -n "end" > trace_marker
+
+cnt=`grep 'hitcount: *1$' events/ftrace/print/hist | wc -l`
+
+if [ $cnt -ne 2 ]; then
+    fail "hist trace_marker trigger did not trigger correctly"
+fi
+
+grep 'hitcount: *1$' events/synthetic/latency/hist > /dev/null || \
+    fail "hist trigger did not trigger "
+
+do_reset
+
+exit 0