[PATCH v2 1/2] selftests/ftrace: Force C locale in ftracetest

[Rui Qi]

Some ftracetest test cases parse command output by matching English
field names. Tools such as readelf may localize their output via
gettext, while ftracetest currently inherits the user locale from
the environment.

If a translated field name is printed, parsing can fail even though
the tested kernel behavior is unchanged. For example, add_remove_uprobe
can fail to find the ELF entry point and then write a uprobe event with
a missing offset.

Export LC_ALL=C in the top-level ftracetest runner so every test case
gets stable command output by default.

Signed-off-by: Rui Qi <qirui.001@xxxxxxxxxxxxx>
---
 tools/testing/selftests/ftrace/ftracetest | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index 8ad2c385407e..246d7e1d015c 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -7,6 +7,9 @@
 #  Written by Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
 #
 
+# Keep command output parsing stable regardless of the user's locale.
+export LC_ALL=C
+
 usage() { # errno [message]
 [ ! -z "$2" ] && echo $2
 echo "Usage: ftracetest [options] [testcase(s)] [testcase-directory(s)]"
-- 
2.20.1