On Mon, 11 Sep 2023 13:09:09 -0400 Steven Rostedt rostedt@goodmis.org wrote:

On Sat, 9 Sep 2023 18:36:39 +0900 "Masami Hiramatsu (Google)" mhiramat@kernel.org wrote:

...

From: Masami Hiramatsu (Google) mhiramat@kernel.org

Fix to unmount the tracefs if the ftracetest mounted it for recovering system environment. If the tracefs is already mounted, this does nothing.

Suggested-by: Mark Brown broonie@kernel.org Link: https://lore.kernel.org/all/29fce076-746c-4650-8358-b4e0fa215cf7@sirena.org.... Fixes: cbd965bde74c ("ftrace/selftests: Return the skip code when tracing directory not configured in kernel") Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org

---

tools/testing/selftests/ftrace/ftracetest | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest index cb5f18c06593..89c212d82256 100755 --- a/tools/testing/selftests/ftrace/ftracetest +++ b/tools/testing/selftests/ftrace/ftracetest @@ -31,6 +31,9 @@ err_ret=1 # kselftest skip code is 4 err_skip=4 +# umount required +UMOUNT_DIR=""

# cgroup RT scheduling prevents chrt commands from succeeding, which # induces failures in test wakeup tests. Disable for the duration of # the tests. @@ -45,6 +48,9 @@ setup() { cleanup() { echo $sched_rt_runtime_orig > $sched_rt_runtime

• if [ "${UMOUNT_DIR}" ]; then

Shouldn't the above be:

 if [ ! -z "${UNMOUNT_DIR}" ]; then

?

I think both are good. What about using '-n' explictly?

[ -n "${UNMOUNT_DIR}" ]

Thanks,

-- Steve

...

• umount ${UMOUNT_DIR} ||:
• fi

} errexit() { # message @@ -160,11 +166,13 @@ if [ -z "$TRACING_DIR" ]; then mount -t tracefs nodev /sys/kernel/tracing || errexit "Failed to mount /sys/kernel/tracing" TRACING_DIR="/sys/kernel/tracing"

•    UMOUNT_DIR=${TRACING_DIR}
  

  # If debugfs exists, then so does /sys/kernel/debug elif [ -d "/sys/kernel/debug" ]; then mount -t debugfs nodev /sys/kernel/debug || errexit "Failed to mount /sys/kernel/debug" TRACING_DIR="/sys/kernel/debug/tracing"

•    UMOUNT_DIR=${TRACING_DIR}
  

  else err_ret=$err_skip errexit "debugfs and tracefs are not configured in this kernel"