kselftests/ftrace: Detect tracefs mount point

Check event is filtered by set_event_pid and options/event-fork.

Signed-off-by Namhyung Kim <[email protected]>

---
 .../selftests/ftrace/test.d/event/event-pid.tc     | 72 ++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 tools/testing/selftests/ftrace/test.d/event/event-pid.tc

tools/testing/selftests/ftrace/test.d/event/event-pid.tc new file +72 -0

new file mode 100644
index 000000000000..d4ab27b522f8
@@ -0,0 +1,72 @@
+#!/bin/sh
+# description: event tracing - restricts events based on pid
+
+do_reset() {
+    echo > set_event
+    echo > set_event_pid
+    echo 0 > options/event-fork
+    clear_trace
+}
+
+fail() { #msg
+    do_reset
+    echo $1
+    exit $FAIL
+}
+
+yield() {
+    ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1
+}
+
+if [ ! -f set_event -o ! -d events/sched ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f set_event_pid ]; then
+    echo "event pid filtering is not supported"
+    exit_unsupported
+fi
+
+reset_tracer
+do_reset
+
+echo 1 > events/sched/sched_switch/enable
+
+yield
+
+count=`cat trace | grep sched_switch | wc -l`
+if [ $count -eq 0 ]; then
+    fail "sched_switch events are not recorded"
+fi
+
+do_reset
+
+read mypid rest < /proc/self/stat
+
+echo $mypid > set_event_pid
+echo 'sched:sched_switch' > set_event
+
+yield
+
+count=`cat trace | grep sched_switch | grep -v "pid=$mypid" | wc -l`
+if [ $count -ne 0 ]; then
+    fail "sched_switch events from other task are recorded"
+fi
+
+do_reset
+
+echo $mypid > set_event_pid
+echo 1 > options/event-fork
+echo 1 > events/sched/sched_switch/enable
+
+yield
+
+count=`cat trace | grep sched_switch | grep -v "pid=$mypid" | wc -l`
+if [ $count -eq 0 ]; then
+    fail "sched_switch events from other task are not recorded"
+fi
+
+do_reset
+
+exit 0

Quoted 3 lines · Namhyung Kim

Check event is filtered by set_event_pid and options/event-fork.

Signed-off-by Namhyung Kim <[email protected]>

Looks good to me. Steve! Ack if you are good with this patch. I can get this into 4.8-rc1

thanks,
-- Shuah

Currently ftracetest assumes tracing directory is located under $DEBUGFS/tracing. But it's possible to mount tracefs directly without debugfs.

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/testing/selftests/ftrace/ftracetest | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

tools/testing/selftests/ftrace/ftracetest +7 -2

index da48812ab95e..4c6a0bf8ba79 100755
@@ -88,7 +88,12 @@ parse_opts() { # opts
 
 # Parameters
 DEBUGFS_DIR=`grep debugfs /proc/mounts | cut -f2 -d' ' | head -1`
-TRACING_DIR=$DEBUGFS_DIR/tracing
+if [ -z "$DEBUGFS_DIR" ]; then
+    TRACING_DIR=`grep tracefs /proc/mounts | cut -f2 -d' ' | head -1`
+else
+    TRACING_DIR=$DEBUGFS_DIR/tracing
+fi
+
 TOP_DIR=`absdir $0`
 TEST_DIR=$TOP_DIR/test.d
 TEST_CASES=`find_testcases $TEST_DIR`

@@ -102,7 +107,7 @@ parse_opts $*
 [ $DEBUG -ne 0 ] && set -x
 
 # Verify parameters
-if [ -z "$DEBUGFS_DIR" -o ! -d "$TRACING_DIR" ]; then
+if [ -z "$TRACING_DIR" -o ! -d "$TRACING_DIR" ]; then
   errexit "No ftrace directory found"
 fi
 

Quoted 5 lines · Namhyung Kim

Currently ftracetest assumes tracing directory is located under $DEBUGFS/tracing. But it's possible to mount tracefs directly without debugfs.

Signed-off-by Namhyung Kim <[email protected]>

Looks good to me. Steve! Ack if you are good with this patch. I can get this into 4.8-rc1