feat: add kunit framework

.github/workflows/cppcheck-differential.yaml

@@ -99,7 +99,7 @@ jobs:
 
       - name: Upload Cppcheck report
         if: ${{ steps.add-kmod.outputs.filtered-full-paths != '' }}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: cppcheck-report
           path: cppcheck-report.txt

.gitignore

@@ -4,3 +4,4 @@ log
 *.log
 coverage_report_agnocastlib
 .vscode
+agnocast_kmod_coverage_report

.pre-commit-config.yaml

@@ -10,3 +10,11 @@ repos:
     hooks:
       - id: markdownlint
         args: [-c, .markdownlint.yaml, --fix]
+
+  - repo: local
+    hooks:
+      - id: kunit
+        name: Run KUnit tests
+        entry: scripts/run_kunit
+        language: system
+        types: [c]

README.md

@@ -109,9 +109,24 @@ You can build, test and generate the coverage report by following:
 bash scripts/test_and_create_report
 ```
 
+## (For developer) Kernel Module Test
+
+A custom kernel with the following CONFIG enabled is required to run KUnit Test and obtain the coverage report (sample custom kernel is placed [here](https://drive.google.com/drive/folders/1sd8ROusgxhnEDOO0hbze3F5y47qtIdcM?usp=drive_link)).
+
+- `CONFIG_KUNIT=y`
+- `CONFIG_GCOV_KERNEL=y`
+
+If booting with the custom kernel, the following script can be used to run unit tests on kernel modules and generate coverage reports.
+
+```bash
+bash script/run_kunit
+```
+
+You can also use [pre-commit](#for-developer-setup-pre-commit).
+
 ## (For developer) Setup pre-commit
 
-The following command allows `clang-format` and `markdownlint` to be run before each commit.
+The following command allows `clang-format`, `markdownlint`, and [KUNIT Test](./kmod/agnocast_kunit.c) to be run before each commit.
 
 ```bash
 bash scripts/setup

kmod/Makefile

@@ -27,6 +27,14 @@ ifeq ($(shell expr $(KERNEL_MAJOR) \< 6 \| $(KERNEL_MAJOR) = 6 \& $(KERNEL_MINOR
   CFLAGS_agnocast.o += -Wno-declaration-after-statement
 endif
 
+# For KUnit
+ifeq ($(CONFIG_KUNIT),y)
+  obj-m += agnocast_kunit.o
+endif
+ifeq ($(CONFIG_GCOV_KERNEL),y)
+  CFLAGS_agnocast.o += -fprofile-arcs -ftest-coverage
+  CFLAGS_agnocast_kunit.o += -fprofile-arcs -ftest-coverage
+endif
 
 all:
 	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

kmod/agnocast_kunit.c

@@ -0,0 +1,22 @@
+#include "agnocast.h"
+
+#include <kunit/test.h>
+
+MODULE_LICENSE("Dual BSD/GPL");
+
+static void agnocast_sample_test_case(struct kunit * test)
+{
+  KUNIT_EXPECT_EQ(test, 1 + 1, 2);
+}
+
+struct kunit_case agnocast_test_cases[] = {
+  KUNIT_CASE(agnocast_sample_test_case),
+  {},
+};
+
+struct kunit_suite agnocast_test_suite = {
+  .name = "agnocast_test_suite",
+  .test_cases = agnocast_test_cases,
+};
+
+kunit_test_suite(agnocast_test_suite);

scripts/run_kunit

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+### Validation
+if [ -f "/boot/config-$(uname -r)" ]; then
+    CONFIG_FILE="/boot/config-$(uname -r)"
+elif [ -f "/proc/config.gz" ]; then
+    zcat /proc/config.gz >/tmp/config-$(uname -r)
+    CONFIG_FILE="/tmp/config-$(uname -r)"
+else
+    echo "Kernel config file not found!"
+    exit 1
+fi
+
+if ! grep -q "CONFIG_KUNIT=y" $CONFIG_FILE; then
+    echo "Skipping KUnit tests as CONFIG_KUNIT is not enabled."
+    exit 0
+fi
+
+### Run KUnit tests
+AGNOCAST_DIR=$(realpath "$(dirname $(readlink -f $0))/..")
+
+AGNOCAST_KMOD_PATH=$AGNOCAST_DIR/kmod
+
+if [ -z "$AGNOCAST_KMOD_PATH" ]; then
+    echo "Usage: create_coverage_report <agnocast_kmod_path>"
+    exit 1
+fi
+
+cd $AGNOCAST_KMOD_PATH
+make clean
+make
+sudo insmod $AGNOCAST_KMOD_PATH/agnocast_kunit.ko
+sudo rmmod agnocast_kunit
+
+sudo lcov --capture --directory /sys/kernel/debug/gcov/$AGNOCAST_KMOD_PATH --output-file $AGNOCAST_DIR/coverage.info
+sudo lcov --remove $AGNOCAST_DIR/coverage.info "*linux*" "*kunit*" --output-file $AGNOCAST_DIR/coverage_filtered.info
+genhtml $AGNOCAST_DIR/coverage_filtered.info --output-directory $AGNOCAST_DIR/agnocast_kmod_coverage_report
+rm -f $AGNOCAST_DIR/coverage.info $AGNOCAST_DIR/coverage_filtered.info $AGNOCAST_KMOD_PATH/*.gcno
+echo "Please open agnocast_kmod_coverage_report/index.html in your web browser."