9 files changed, 141 insertions, 4 deletions
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 9cd47a00..22f24bdd 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -379,6 +379,10 @@ jobs:
           -DKDIR=/usr/src/linux-headers-`uname -r` 
           -DLUA=TRUE -DSHAPER=TRUE -DRADIUS=TRUE ..
 
+      - name: Test kernel module installation
+        working-directory: ./build
+        run: ctest --output-on-failure -R '^kernel-module-install$'
+
       - name: make && make install
         working-directory: ./build
         run: make && sudo make install
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 72b5eb83..4c856491 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -101,3 +101,14 @@ if (BUILD_VLAN_MON_DRIVER)
 endif ()
 
 CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in ${CMAKE_CURRENT_BINARY_DIR}/config.h)
+
+include(CTest)
+
+if (BUILD_TESTING)
+	add_test(
+		NAME kernel-module-install
+		COMMAND sh
+			${CMAKE_CURRENT_SOURCE_DIR}/tests/kernel-module-install/test.sh
+			${CMAKE_COMMAND}
+	)
+endif ()
diff --git a/cmake/install-kernel-module.cmake b/cmake/install-kernel-module.cmake
new file mode 100644
index 00000000..1350e7c9
--- /dev/null
+++ b/cmake/install-kernel-module.cmake
@@ -0,0 +1,35 @@
+if (NOT DEFINED KERNEL_BUILD_DIR OR KERNEL_BUILD_DIR STREQUAL "")
+	message(FATAL_ERROR "Kernel build directory is not set")
+endif ()
+
+if (NOT DEFINED KERNEL_MODULE_BUILD_DIR OR
+    KERNEL_MODULE_BUILD_DIR STREQUAL "")
+	message(FATAL_ERROR "Kernel module build directory is not set")
+endif ()
+
+set(_install_command
+	make -C "${KERNEL_BUILD_DIR}"
+	"M=${KERNEL_MODULE_BUILD_DIR}"
+	modules_install
+)
+
+# DESTDIR is the conventional CMake staging root.  The kernel build system
+# uses INSTALL_MOD_PATH for the same purpose, so propagate it explicitly.
+if (NOT "$ENV{DESTDIR}" STREQUAL "")
+	list(APPEND _install_command "INSTALL_MOD_PATH=$ENV{DESTDIR}")
+endif ()
+
+execute_process(
+	COMMAND ${_install_command}
+	RESULT_VARIABLE _install_result
+)
+
+if (NOT "${_install_result}" STREQUAL "0")
+	message(FATAL_ERROR
+		"Failed to install kernel module from "
+		"${KERNEL_MODULE_BUILD_DIR} (exit status: ${_install_result})"
+	)
+endif ()
+
+unset(_install_command)
+unset(_install_result)
diff --git a/drivers/ipoe/CMakeLists.txt b/drivers/ipoe/CMakeLists.txt
index d0d6902c..5bbac4f6 100644
--- a/drivers/ipoe/CMakeLists.txt
+++ b/drivers/ipoe/CMakeLists.txt
@@ -41,5 +41,9 @@ ADD_CUSTOM_TARGET(ipoe_drv ALL
 )
 
 IF (NOT DEFINED CPACK_TYPE)
-	INSTALL(CODE "EXECUTE_PROCESS(COMMAND make -C ${KDIR} M=${CMAKE_CURRENT_BINARY_DIR}/drivers/ipoe modules_install)")
+	INSTALL(CODE "
+		set(KERNEL_BUILD_DIR [==[${KDIR}]==])
+		set(KERNEL_MODULE_BUILD_DIR [==[${CMAKE_CURRENT_BINARY_DIR}/driver]==])
+		include([==[${CMAKE_SOURCE_DIR}/cmake/install-kernel-module.cmake]==])
+	")
 ENDIF()
diff --git a/drivers/ppposeq/CMakeLists.txt b/drivers/ppposeq/CMakeLists.txt
index 08c45c76..daeffb11 100644
--- a/drivers/ppposeq/CMakeLists.txt
+++ b/drivers/ppposeq/CMakeLists.txt
@@ -15,5 +15,9 @@ ADD_CUSTOM_TARGET(ppposeq_drv ALL
 )
 
 IF (NOT DEFINED CPACK_TYPE)
-	INSTALL(CODE "EXECUTE_PROCESS(COMMAND make -C ${KDIR} M=${CMAKE_CURRENT_BINARY_DIR}/driver modules_install)")
+	INSTALL(CODE "
+		set(KERNEL_BUILD_DIR [==[${KDIR}]==])
+		set(KERNEL_MODULE_BUILD_DIR [==[${CMAKE_CURRENT_BINARY_DIR}/driver]==])
+		include([==[${CMAKE_SOURCE_DIR}/cmake/install-kernel-module.cmake]==])
+	")
 ENDIF()
diff --git a/drivers/vlan_mon/CMakeLists.txt b/drivers/vlan_mon/CMakeLists.txt
index b4c8e348..5269805d 100644
--- a/drivers/vlan_mon/CMakeLists.txt
+++ b/drivers/vlan_mon/CMakeLists.txt
@@ -16,5 +16,9 @@ ADD_CUSTOM_TARGET(vlan_mon_drv ALL
 )
 
 if (NOT DEFINED CPACK_TYPE)
-	INSTALL(CODE "EXECUTE_PROCESS(COMMAND make -C ${KDIR} M=${CMAKE_CURRENT_BINARY_DIR}/drivers/vlan_mon modules_install)")
+	INSTALL(CODE "
+		set(KERNEL_BUILD_DIR [==[${KDIR}]==])
+		set(KERNEL_MODULE_BUILD_DIR [==[${CMAKE_CURRENT_BINARY_DIR}/driver]==])
+		include([==[${CMAKE_SOURCE_DIR}/cmake/install-kernel-module.cmake]==])
+	")
 endif ()
diff --git a/tests/README.md b/tests/README.md
index 689a16d8..65afd254 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -2,6 +2,25 @@
 
 These tests are done for Ubuntu and Debian distros. Please use latest stable Debian or Ubuntu to run the tests.
 
+## Kernel module installation test
+
+The kernel module installation regression test is rootless and does not need
+kernel headers. It uses a fake kernel build tree to verify that `ipoe`,
+`vlan_mon`, and `ppposeq` are installed from their actual build directories,
+honor `DESTDIR`, and make installation fail when `modules_install` fails.
+
+Run it through CTest after configuring the project:
+
+```bash
+ctest --test-dir build --output-on-failure -R '^kernel-module-install$'
+```
+
+It can also be run directly from the repository root:
+
+```bash
+sh tests/kernel-module-install/test.sh cmake
+```
+
 ## Preparations
 
 Install pytest
@@ -100,4 +119,4 @@ If you want to re-run tests 'from scratch', you may want to remove coverage data
 # from root dir (parent for this dir)
 sudo gcovr -d # build report and delete
 sudo gcovr -d # check that data is deleted (any coverage = 0%)
-```
-\ No newline at end of file
+```
diff --git a/tests/kernel-module-install/Makefile b/tests/kernel-module-install/Makefile
new file mode 100644
index 00000000..9b8bf2bc
--- /dev/null
+++ b/tests/kernel-module-install/Makefile
@@ -0,0 +1,18 @@
+.PHONY: kernelrelease modules modules_install
+
+kernelrelease:
+	@printf '%s\n' test-kernel
+
+modules:
+	@module=$$(basename "$$(dirname "$(M)")"); \
+	printf 'test module %s\n' "$$module" > "$(M)/$$module.ko"
+
+modules_install:
+	@test "$(M)" != ""
+	@test -d "$(M)"
+	@if test "$${FAIL_MODULES_INSTALL:-0}" = 1; then exit 42; fi
+	@module=$$(basename "$$(dirname "$(M)")"); \
+	test -f "$(M)/$$module.ko"; \
+	destination="$(INSTALL_MOD_PATH)/lib/modules/test-kernel/extra"; \
+	mkdir -p "$$destination"; \
+	cp "$(M)/$$module.ko" "$$destination/$$module.ko"
diff --git a/tests/kernel-module-install/test.sh b/tests/kernel-module-install/test.sh
new file mode 100644
index 00000000..1fbfd623
--- /dev/null
+++ b/tests/kernel-module-install/test.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+
+set -eu
+
+cmake_command=${1:-cmake}
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+source_dir=$(CDPATH= cd -- "${script_dir}/../.." && pwd)
+work_dir=$(mktemp -d)
+trap 'rm -rf "${work_dir}"' EXIT HUP INT TERM
+
+"${cmake_command}" \
+	-S "${source_dir}" \
+	-B "${work_dir}/build" \
+	-DBUILD_TESTING=OFF \
+	-DBUILD_DRIVER_ONLY=TRUE \
+	-DBUILD_IPOE_DRIVER=TRUE \
+	-DBUILD_VLAN_MON_DRIVER=TRUE \
+	-DBUILD_PPPOSEQ_DRIVER=TRUE \
+	-DIGNORE_GIT=TRUE \
+	-DKDIR="${script_dir}"
+
+"${cmake_command}" --build "${work_dir}/build" --parallel 2
+
+DESTDIR="${work_dir}/stage" \
+	"${cmake_command}" --install "${work_dir}/build"
+
+test -f "${work_dir}/stage/lib/modules/test-kernel/extra/ipoe.ko"
+test -f "${work_dir}/stage/lib/modules/test-kernel/extra/vlan_mon.ko"
+test -f "${work_dir}/stage/lib/modules/test-kernel/extra/ppposeq.ko"
+
+if FAIL_MODULES_INSTALL=1 DESTDIR="${work_dir}/failed-stage" \
+	"${cmake_command}" --install "${work_dir}/build" \
+	>"${work_dir}/failed-install.log" 2>&1; then
+	printf '%s\n' 'kernel module installation unexpectedly succeeded' >&2
+	exit 1
+fi
+
+grep -q 'Failed to install kernel module' "${work_dir}/failed-install.log"