[RFC tracing 3/4] selftests/ftrace: add test coverage for filter predicates

[Alan Maguire]

add tests verifying filter predicates work for 1/2/4/8/16 byte values
and strings; use predicates at event and subsystem level.

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
 .../selftests/ftrace/test.d/event/filter.tc   | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 tools/testing/selftests/ftrace/test.d/event/filter.tc

diff --git a/tools/testing/selftests/ftrace/test.d/event/filter.tc b/tools/testing/selftests/ftrace/test.d/event/filter.tc
new file mode 100644
index 000000000000..396383519f84
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/event/filter.tc
@@ -0,0 +1,62 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event tracing - enable filter predicates
+# requires: set_event events/sched
+# flags:
+
+do_reset() {
+    echo 0 > ${event}/enable
+    echo 0 > ${event}/filter
+    clear_trace
+}
+
+fail() { #msg
+    echo $1
+    exit_fail
+}
+
+# verify filter predicates at trace event/subsys level for
+# - string (prev_comm)
+# - 1-byte value (common_flags)
+# - 2-byte value (common_type)
+# - 4-byte value (next_pid)
+# - 8-byte value (prev_state)
+
+for event in events/sched/sched_switch events/sched
+do
+    for filter in	"prev_comm == 'ping'"	\
+	    		"common_flags != 0"	\
+			"common_type >= 0"	\
+	    		"next_pid > 0"		\
+			"prev_state != 0"
+    do
+        echo "$filter" > ${event}/filter
+        echo 1 > ${event}/enable
+        yield
+        count=`grep sched_switch trace|wc -l`
+        if [ $count -lt 1 ]; then
+            fail "at least one $event should be recorded for '$filter'"
+        fi
+        do_reset
+    done
+done
+
+# verify '==', '!=' filter predicates for 16-byte array at event/subsys
+# level
+
+LOCALHOST="-6 ::1"
+for event in events/fib6/fib6_table_lookup events/fib6 ; do
+    for filter in "dst == 0x00000000000000000000000000000001" \
+	          "src != 0x00000000000000000000000000000001"
+    do
+	echo "$filter" > ${event}/filter
+	echo 1 > ${event}/enable
+	yield
+	count=`grep fib6_table_lookup trace|wc -l`
+        if [ $count -lt 1 ]; then
+            fail "at least one $event should be recorded for '$filter'"
+        fi
+        do_reset
+    done
+done
+exit 0
-- 
2.31.1