Add a test to exercize cpu hotplug with the function tracer active to ensure that sensitive functions in idle path are excluded from being traced. This helps catch issues such as the one fixed by commit 4b3338aaa74d ("powerpc/ftrace: Fix stack teardown in ftrace_no_trace").
Signed-off-by: Naveen N Rao naveen@kernel.org --- .../ftrace/test.d/ftrace/func_hotplug.tc | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc
diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc new file mode 100644 index 000000000000..49731a2b5c23 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc @@ -0,0 +1,30 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: ftrace - function trace across cpu hotplug +# requires: function:tracer + +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 cpu hotplug in UP environment" + exit_unresolved +fi + +echo 0 > tracing_on +echo > trace +: "Set CPU1 offline/online with function tracer enabled" +echo function > current_tracer +echo 1 > tracing_on +(echo 0 > /sys/devices/system/cpu/cpu1/online) +(echo "forked"; sleep 1) +(echo 1 > /sys/devices/system/cpu/cpu1/online) +echo 0 > tracing_on + +: "Check CPU1 events are recorded" +grep -q -e "[001]" trace
base-commit: b85ea95d086471afb4ad062012a4d73cd328fa86