On Sat, 2025-01-11 at 15:42 -0300, Filipe Xavier wrote:
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
Thanks for the new test Filipe!
I have some nits below, but these don't need to be addressed for the test to be merged. Either way,
Reviewed-by: Marcos Paulo de Souza mpdesouza@suse.com Tested-by: Marcos Paulo de Souza mpdesouza@suse.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..e6c13514002dae5f8d7461f90b8 241ab43024ea4 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
}
I believe that this could be a separate patch, since this is new functionality that's being added to functions.sh, and not exactly related to the new test.
function set_dynamic_debug() { diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh index fe14f248913acbec46fb6c0fec38a2fc84209d39..66af5d726c52e48e5177804e182 b4ff31784d5ac 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
The test works, and that's very cool. But when running locally, I find the if we miss check_result call it doesn't add a newline after the "ok":
... # timeout set to 0 # selftests: livepatch: test-ftrace.sh # TEST: livepatch interaction with ftrace_enabled sysctl ... ok # TEST: trace livepatched function and check that the live patch remains in effect ... ok 5 selftests: livepatch: test-ftrace.sh # timeout set to 0 # selftests: livepatch: test-sysfs.sh ...
If the check_result below is added the output if sane again:
... # selftests: livepatch: test-ftrace.sh # TEST: livepatch interaction with ftrace_enabled sysctl ... ok # TEST: trace livepatched function and check that the live patch remains in effect ... ok ok 5 selftests: livepatch: test-ftrace.sh ...
I checked and this would be the only one test without using check_result, so maybe we should add this either way? I'm not sure what you guys think about it.
diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh index 66af5d726c52..135c0fb17a98 100755 --- a/tools/testing/selftests/livepatch/test-ftrace.sh +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -93,5 +93,18 @@ if [ "$FOUND" -eq 1 ]; then die "livepatch kselftest(s) failed" fi
+check_result "% insmod test_modules/$MOD_LIVEPATCH.ko +livepatch: enabling patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': initializing patching transition +livepatch: '$MOD_LIVEPATCH': starting patching transition +livepatch: '$MOD_LIVEPATCH': completing patching transition +livepatch: '$MOD_LIVEPATCH': patching complete +% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH/enabled +livepatch: '$MOD_LIVEPATCH': initializing unpatching transition +livepatch: '$MOD_LIVEPATCH': starting unpatching transition +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +% rmmod $MOD_LIVEPATCH" +
exit 0
base-commit: fc033cf25e612e840e545f8d5ad2edd6ba613ed5 change-id: 20250101-ftrace-selftest-livepatch-161fb77dbed8
Best regards,