[PATCH 2/4] selftests: livepatch: Remove leftover modules when a testcase fails

[Marcos Paulo de Souza <mpdesouza@suse.com>]

The current livepatch selftest scripts load modules, run tests and
unloads them. If the test fails, it can leave loaded modules behind, and
in some cases making it impossible to run the next tests.

This approach tracks down the loaded modules, and in case of a test
failure, or premature exit of the script, the cleanup function will
be called by the trap installed on setup_config function.

The cleanup function iterates over the list of leftover loaded modules,
unloading them. The function also checks if the given module is a
livepatch, properly disabling it before unloading.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
 tools/testing/selftests/livepatch/functions.sh | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
index 3ec0b7962fc5..25f137003865 100644
--- a/tools/testing/selftests/livepatch/functions.sh
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -15,6 +15,8 @@ if [[ -e /sys/kernel/tracing/trace ]]; then
 else
 	SYSFS_TRACING_DIR="$SYSFS_DEBUG_DIR/tracing"
 fi
+# List of loaded modules used in tests
+TEST_MODS=()
 
 # Kselftest framework requirement - SKIP code is 4
 ksft_skip=4
@@ -125,6 +127,14 @@ function set_ftrace_enabled() {
 }
 
 function cleanup() {
+	# Remove leftover modules in reverse order to handle dependencies
+	for mod_item in "${TEST_MODS[@]}"; do
+		if is_livepatch_mod "$mod_item"; then
+			disable_lp "$mod_item"
+		fi
+		_remove_mod "$mod_item"
+	done
+
 	pop_config
 }
 
@@ -181,6 +191,9 @@ function __load_mod() {
 	# Wait for module in sysfs ...
 	loop_until '[[ -e "/sys/module/$mod" ]]' ||
 		die "failed to load module $mod"
+
+	# Store the module in the modules list
+	TEST_MODS+=("$mod")
 }
 
 
@@ -262,12 +275,20 @@ function _remove_mod() {
 		die "failed to unload module $mod (/sys/module)"
 }
 
-# unload_mod(modname) - unload a kernel module
+# unload_mod(modname) - unload a kernel module and remove it from TEST_MODS
 #	modname - module name to unload
 function unload_mod() {
 	local mod="$1"
 
 	_remove_mod "$mod"
+
+	# Remove from TEST_MODS array
+	for i in "${!TEST_MODS[@]}"; do
+		if [[ "${TEST_MODS[$i]}" == "$mod" ]]; then
+			unset 'TEST_MODS[$i]'
+			break
+		fi
+	done
 }
 
 # unload_lp(modname) - unload a kernel module with a livepatch

-- 
2.54.0