On Thu, Jan 02, 2025 at 03:42:10PM -0300, Filipe Xavier wrote: > This new test makes sure that ftrace can trace a > function that was introduced by a livepatch. > Hi Filipe, Thanks for adding a test! Aside: another similar test could verify that the original function, in this case cmdline_proc_show(), can still be traced despite it being livepatched. That may be non-intuitive but it demonstrates how the ftrace handler works. > Signed-off-by: Filipe Xavier <felipeaggger@xxxxxxxxx> > --- > tools/testing/selftests/livepatch/test-ftrace.sh | 37 ++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh > index fe14f248913acbec46fb6c0fec38a2fc84209d39..5f0d5308c88669e84210393ce7b8aa138b694ebd 100755 > --- a/tools/testing/selftests/livepatch/test-ftrace.sh > +++ b/tools/testing/selftests/livepatch/test-ftrace.sh > @@ -61,4 +61,41 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete > % rmmod $MOD_LIVEPATCH" > > > +# - verify livepatch can load > +# - check traces if have a patched function nit: wording? "check if traces have a patched function" ? > +# - unload livepatch and reset trace > + > +start_test "livepatch trace patched function and check that the live patch remains in effect" nit: wording? "trace livepatched function and check ..." ? > + > +TRACE_FILE="$SYSFS_DEBUG_DIR/tracing/trace" > +FUNCTION_NAME="livepatch_cmdline_proc_show" > + > +load_lp $MOD_LIVEPATCH > + > +echo $FUNCTION_NAME > $SYSFS_DEBUG_DIR/tracing/set_ftrace_filter > +echo "function" > $SYSFS_DEBUG_DIR/tracing/current_tracer > +echo "" > $TRACE_FILE A few suggestions: - The tracing is also dependent on the 'tracing_on' file, so if it happens to be turned off, the test will fail. - See functions.sh :: push_config() and pop_config() for an example of saving the existing values rather than turning them all off at the end of the test. - Nitpick: shellcheck suggests wrapping filenames in double quotations, applicable in several places. > + > +if [[ "$(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 > + > +# Reset tracing > +echo "nop" > $SYSFS_DEBUG_DIR/tracing/current_tracer > +echo "" > $SYSFS_DEBUG_DIR/tracing/set_ftrace_filter > +echo "" > $TRACE_FILE > + > +if [ "$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, > -- > Filipe Xavier <felipeaggger@xxxxxxxxx> > Thanks, -- Joe
