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| author |   Naveen N Rao <naveen@kernel.org> | 2024-02-16 15:26:26 +0530 |
|---|---|---|
| committer |   Shuah Khan <skhan@linuxfoundation.org> | 2024-02-20 17:28:19 -0700 |
| commit | 3425a2005b291b62b6f6deeeab1156839c41cf85 (patch) | |
| tree | 0cfa9b91654d64459729325c812e148675330a04 /tools/testing/selftests/ftrace | |
| parent | selftest: ftrace: fix minor typo in log (diff) | |
| download | wireguard-linux-3425a2005b291b62b6f6deeeab1156839c41cf85.tar.xz wireguard-linux-3425a2005b291b62b6f6deeeab1156839c41cf85.zip | |
selftests/ftrace: Add test to exercize function tracer across cpu hotplug
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>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'tools/testing/selftests/ftrace')
| -rw-r--r-- | tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc | 42 |
1 files changed, 42 insertions, 0 deletions
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..ccfbfde3d942 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc @@ -0,0 +1,42 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# 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 cannot test cpu hotplug in UP environment" + exit_unresolved +fi + +# Find online cpu +for i in /sys/devices/system/cpu/cpu[1-9]*; do + if [ -f $i/online ] && [ "$(cat $i/online)" = "1" ]; then + cpu=$i + break + fi +done + +if [ -z "$cpu" ]; then + echo "We cannot test cpu hotplug with a single cpu online" + exit_unresolved +fi + +echo 0 > tracing_on +echo > trace + +: "Set $(basename $cpu) offline/online with function tracer enabled" +echo function > current_tracer +echo 1 > tracing_on +(echo 0 > $cpu/online) +(echo "forked"; sleep 1) +(echo 1 > $cpu/online) +echo 0 > tracing_on +echo nop > current_tracer |