From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
A new file was added to the tracing directory that will allow a user to
place a PID into it and the task associated to that PID will not have its
events traced. If the event-fork option is enabled, then neither will the
children of that task have its events traced.
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
.../ftrace/test.d/event/event-no-pid.tc | 125 ++++++++++++++++++
1 file changed, 125 insertions(+)
create mode 100644 tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
diff --git a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
new file mode 100644
index 000000000000..f0f366f18d0c
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc
@@ -0,0 +1,125 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event tracing - restricts events based on pid notrace filtering
+# flags: instance
+
+do_reset() {
+ echo > set_event
+ echo > set_event_pid
+ echo > set_event_notrace_pid
+ echo 0 > options/event-fork
+ echo 0 > events/enable
+ clear_trace
+ echo 1 > tracing_on
+}
+
+fail() { #msg
+ cat trace
+ do_reset
+ echo $1
+ exit_fail
+}
+
+count_pid() {
+ pid=$@
+ cat trace | grep -v '^#' | sed -e 's/[^-]*-\([0-9]*\).*/\1/' | grep $pid | wc -l
+}
+
+count_no_pid() {
+ pid=$1
+ cat trace | grep -v '^#' | sed -e 's/[^-]*-\([0-9]*\).*/\1/' | grep -v $pid | wc -l
+}
+
+enable_system() {
+ system=$1
+
+ if [ -d events/$system ]; then
+ echo 1 > events/$system/enable
+ fi
+}
+
+enable_events() {
+ echo 0 > tracing_on
+ # Enable common groups of events, as all events can allow for
+ # events to be traced via scheduling that we don't care to test.
+ enable_system syscalls
+ enable_system rcu
+ enable_system block
+ enable_system exceptions
+ enable_system irq
+ enable_system net
+ enable_system power
+ enable_system signal
+ enable_system sock
+ enable_system timer
+ enable_system thermal
+ echo 1 > tracing_on
+}
+
+if [ ! -f set_event -o ! -d events/sched ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f set_event_pid -o ! -f set_event_notrace_pid ]; then
+ echo "event pid notrace filtering is not supported"
+ exit_unsupported
+fi
+
+echo 0 > options/event-fork
+
+do_reset
+
+read mypid rest < /proc/self/stat
+
+echo $mypid > set_event_notrace_pid
+grep -q $mypid set_event_notrace_pid
+
+enable_events
+
+yield
+
+echo 0 > tracing_on
+
+cnt=`count_pid $mypid`
+if [ $cnt -ne 0 ]; then
+ fail "Filtered out task has events"
+fi
+
+cnt=`count_no_pid $mypid`
+if [ $cnt -eq 0 ]; then
+ fail "No other events were recorded"
+fi
+
+do_reset
+
+echo $mypid > set_event_notrace_pid
+echo 1 > options/event-fork
+
+enable_events
+
+yield &
+child=$!
+echo "child = $child"
+wait $child
+
+echo 0 > tracing_on
+
+cnt=`count_pid $mypid`
+if [ $cnt -ne 0 ]; then
+ fail "Filtered out task has events"
+fi
+
+cnt=`count_pid $child`
+if [ $cnt -ne 0 ]; then
+ fail "Child of filtered out taskhas events"
+fi
+
+cnt=`count_no_pid $mypid`
+if [ $cnt -eq 0 ]; then
+ fail "No other events were recorded"
+fi
+
+do_reset
+
+exit 0
--
2.25.1
