This new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com --- Changes in v2: - functions.sh: added reset tracing on push and pop_config. - test-ftrace.sh: enabled tracing_on before test init. - nitpick: added double quotations on filenames and fixed some wording. - Link to v1: https://lore.kernel.org/r/20250102-ftrace-selftest-livepatch-v1-1-84880baefc... --- tools/testing/selftests/livepatch/functions.sh | 14 ++++++++++ tools/testing/selftests/livepatch/test-ftrace.sh | 33 ++++++++++++++++++++++++ 2 files changed, 47 insertions(+)
diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index e5d06fb402335d85959bafe099087effc6ddce12..e6c13514002dae5f8d7461f90b8241ab43024ea4 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -62,6 +62,9 @@ function push_config() { awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled) KPROBE_ENABLED=$(cat "$SYSFS_KPROBES_DIR/enabled") + TRACING_ON=$(cat "$SYSFS_DEBUG_DIR/tracing/tracing_on") + CURRENT_TRACER=$(cat "$SYSFS_DEBUG_DIR/tracing/current_tracer") + FTRACE_FILTER=$(cat "$SYSFS_DEBUG_DIR/tracing/set_ftrace_filter") }
function pop_config() { @@ -74,6 +77,17 @@ function pop_config() { if [[ -n "$KPROBE_ENABLED" ]]; then echo "$KPROBE_ENABLED" > "$SYSFS_KPROBES_DIR/enabled" fi + if [[ -n "$TRACING_ON" ]]; then + echo "$TRACING_ON" > "$SYSFS_DEBUG_DIR/tracing/tracing_on" + fi + if [[ -n "$CURRENT_TRACER" ]]; then + echo "$CURRENT_TRACER" > "$SYSFS_DEBUG_DIR/tracing/current_tracer" + fi + if [[ "$FTRACE_FILTER" == *"#"* ]]; then + echo > "$SYSFS_DEBUG_DIR/tracing/set_ftrace_filter" + elif [[ -n "$FTRACE_FILTER" ]]; then + echo "$FTRACE_FILTER" > "$SYSFS_DEBUG_DIR/tracing/set_ftrace_filter" + fi }
function set_dynamic_debug() { diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh index fe14f248913acbec46fb6c0fec38a2fc84209d39..66af5d726c52e48e5177804e182b4ff31784d5ac 100755 --- a/tools/testing/selftests/livepatch/test-ftrace.sh +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -61,4 +61,37 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete % rmmod $MOD_LIVEPATCH"
+# - verify livepatch can load +# - check if traces have a patched function +# - unload livepatch and reset trace + +start_test "trace livepatched function and check that the live patch remains in effect" + +TRACE_FILE="$SYSFS_DEBUG_DIR/tracing/trace" +FUNCTION_NAME="livepatch_cmdline_proc_show" + +load_lp $MOD_LIVEPATCH + +echo 1 > "$SYSFS_DEBUG_DIR/tracing/tracing_on" +echo $FUNCTION_NAME > "$SYSFS_DEBUG_DIR/tracing/set_ftrace_filter" +echo "function" > "$SYSFS_DEBUG_DIR/tracing/current_tracer" +echo "" > "$TRACE_FILE" + +if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi + +grep -q $FUNCTION_NAME "$TRACE_FILE" +FOUND=$? + +disable_lp $MOD_LIVEPATCH +unload_lp $MOD_LIVEPATCH + +if [ "$FOUND" -eq 1 ]; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi + + exit 0
--- base-commit: fc033cf25e612e840e545f8d5ad2edd6ba613ed5 change-id: 20250101-ftrace-selftest-livepatch-161fb77dbed8
Best regards,