1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3
4set -u
5set -e
6
7# This script currently only works for x86_64 and s390x, as
8# it is based on the VM image used by the BPF CI, which is
9# available only for these architectures.
10ARCH="$(uname -m)"
11case "${ARCH}" in
12s390x)
13	QEMU_BINARY=qemu-system-s390x
14	QEMU_CONSOLE="ttyS1"
15	QEMU_FLAGS=(-smp 2)
16	BZIMAGE="arch/s390/boot/vmlinux"
17	;;
18x86_64)
19	QEMU_BINARY=qemu-system-x86_64
20	QEMU_CONSOLE="ttyS0,115200"
21	QEMU_FLAGS=(-cpu host -smp 8)
22	BZIMAGE="arch/x86/boot/bzImage"
23	;;
24aarch64)
25	QEMU_BINARY=qemu-system-aarch64
26	QEMU_CONSOLE="ttyAMA0,115200"
27	QEMU_FLAGS=(-M virt,gic-version=3 -cpu host -smp 8)
28	BZIMAGE="arch/arm64/boot/Image"
29	;;
30*)
31	echo "Unsupported architecture"
32	exit 1
33	;;
34esac
35DEFAULT_COMMAND="./test_progs"
36MOUNT_DIR="mnt"
37ROOTFS_IMAGE="root.img"
38OUTPUT_DIR="$HOME/.bpf_selftests"
39KCONFIG_REL_PATHS=("tools/testing/selftests/bpf/config" "tools/testing/selftests/bpf/config.${ARCH}")
40INDEX_URL="https://raw.githubusercontent.com/libbpf/ci/master/INDEX"
41NUM_COMPILE_JOBS="$(nproc)"
42LOG_FILE_BASE="$(date +"bpf_selftests.%Y-%m-%d_%H-%M-%S")"
43LOG_FILE="${LOG_FILE_BASE}.log"
44EXIT_STATUS_FILE="${LOG_FILE_BASE}.exit_status"
45
46usage()
47{
48	cat <<EOF
49Usage: $0 [-i] [-s] [-d <output_dir>] -- [<command>]
50
51<command> is the command you would normally run when you are in
52tools/testing/selftests/bpf. e.g:
53
54	$0 -- ./test_progs -t test_lsm
55
56If no command is specified and a debug shell (-s) is not requested,
57"${DEFAULT_COMMAND}" will be run by default.
58
59If you build your kernel using KBUILD_OUTPUT= or O= options, these
60can be passed as environment variables to the script:
61
62  O=<kernel_build_path> $0 -- ./test_progs -t test_lsm
63
64or
65
66  KBUILD_OUTPUT=<kernel_build_path> $0 -- ./test_progs -t test_lsm
67
68Options:
69
70	-i)		Update the rootfs image with a newer version.
71	-d)		Update the output directory (default: ${OUTPUT_DIR})
72	-j)		Number of jobs for compilation, similar to -j in make
73			(default: ${NUM_COMPILE_JOBS})
74	-s)		Instead of powering off the VM, start an interactive
75			shell. If <command> is specified, the shell runs after
76			the command finishes executing
77EOF
78}
79
80unset URLS
81populate_url_map()
82{
83	if ! declare -p URLS &> /dev/null; then
84		# URLS contain the mapping from file names to URLs where
85		# those files can be downloaded from.
86		declare -gA URLS
87		while IFS=$'\t' read -r name url; do
88			URLS["$name"]="$url"
89		done < <(curl -Lsf ${INDEX_URL})
90	fi
91}
92
93download()
94{
95	local file="$1"
96
97	if [[ ! -v URLS[$file] ]]; then
98		echo "$file not found" >&2
99		return 1
100	fi
101
102	echo "Downloading $file..." >&2
103	curl -Lsf "${URLS[$file]}" "${@:2}"
104}
105
106newest_rootfs_version()
107{
108	{
109	for file in "${!URLS[@]}"; do
110		if [[ $file =~ ^"${ARCH}"/libbpf-vmtest-rootfs-(.*)\.tar\.zst$ ]]; then
111			echo "${BASH_REMATCH[1]}"
112		fi
113	done
114	} | sort -rV | head -1
115}
116
117download_rootfs()
118{
119	local rootfsversion="$1"
120	local dir="$2"
121
122	if ! which zstd &> /dev/null; then
123		echo 'Could not find "zstd" on the system, please install zstd'
124		exit 1
125	fi
126
127	download "${ARCH}/libbpf-vmtest-rootfs-$rootfsversion.tar.zst" |
128		zstd -d | sudo tar -C "$dir" -x
129}
130
131recompile_kernel()
132{
133	local kernel_checkout="$1"
134	local make_command="$2"
135
136	cd "${kernel_checkout}"
137
138	${make_command} olddefconfig
139	${make_command}
140}
141
142mount_image()
143{
144	local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
145	local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
146
147	sudo mount -o loop "${rootfs_img}" "${mount_dir}"
148}
149
150unmount_image()
151{
152	local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
153
154	sudo umount "${mount_dir}" &> /dev/null
155}
156
157update_selftests()
158{
159	local kernel_checkout="$1"
160	local selftests_dir="${kernel_checkout}/tools/testing/selftests/bpf"
161
162	cd "${selftests_dir}"
163	${make_command}
164
165	# Mount the image and copy the selftests to the image.
166	mount_image
167	sudo rm -rf "${mount_dir}/root/bpf"
168	sudo cp -r "${selftests_dir}" "${mount_dir}/root"
169	unmount_image
170}
171
172update_init_script()
173{
174	local init_script_dir="${OUTPUT_DIR}/${MOUNT_DIR}/etc/rcS.d"
175	local init_script="${init_script_dir}/S50-startup"
176	local command="$1"
177	local exit_command="$2"
178
179	mount_image
180
181	if [[ ! -d "${init_script_dir}" ]]; then
182		cat <<EOF
183Could not find ${init_script_dir} in the mounted image.
184This likely indicates a bad rootfs image, Please download
185a new image by passing "-i" to the script
186EOF
187		exit 1
188
189	fi
190
191	sudo bash -c "echo '#!/bin/bash' > ${init_script}"
192
193	if [[ "${command}" != "" ]]; then
194		sudo bash -c "cat >>${init_script}" <<EOF
195# Have a default value in the exit status file
196# incase the VM is forcefully stopped.
197echo "130" > "/root/${EXIT_STATUS_FILE}"
198
199{
200	cd /root/bpf
201	echo ${command}
202	stdbuf -oL -eL ${command}
203	echo "\$?" > "/root/${EXIT_STATUS_FILE}"
204} 2>&1 | tee "/root/${LOG_FILE}"
205# Ensure that the logs are written to disk
206sync
207EOF
208	fi
209
210	sudo bash -c "echo ${exit_command} >> ${init_script}"
211	sudo chmod a+x "${init_script}"
212	unmount_image
213}
214
215create_vm_image()
216{
217	local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
218	local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
219
220	rm -rf "${rootfs_img}"
221	touch "${rootfs_img}"
222	chattr +C "${rootfs_img}" >/dev/null 2>&1 || true
223
224	truncate -s 2G "${rootfs_img}"
225	mkfs.ext4 -q "${rootfs_img}"
226
227	mount_image
228	download_rootfs "$(newest_rootfs_version)" "${mount_dir}"
229	unmount_image
230}
231
232run_vm()
233{
234	local kernel_bzimage="$1"
235	local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
236
237	if ! which "${QEMU_BINARY}" &> /dev/null; then
238		cat <<EOF
239Could not find ${QEMU_BINARY}
240Please install qemu or set the QEMU_BINARY environment variable.
241EOF
242		exit 1
243	fi
244
245	${QEMU_BINARY} \
246		-nodefaults \
247		-display none \
248		-serial mon:stdio \
249		"${QEMU_FLAGS[@]}" \
250		-enable-kvm \
251		-m 4G \
252		-drive file="${rootfs_img}",format=raw,index=1,media=disk,if=virtio,cache=none \
253		-kernel "${kernel_bzimage}" \
254		-append "root=/dev/vda rw console=${QEMU_CONSOLE}"
255}
256
257copy_logs()
258{
259	local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
260	local log_file="${mount_dir}/root/${LOG_FILE}"
261	local exit_status_file="${mount_dir}/root/${EXIT_STATUS_FILE}"
262
263	mount_image
264	sudo cp ${log_file} "${OUTPUT_DIR}"
265	sudo cp ${exit_status_file} "${OUTPUT_DIR}"
266	sudo rm -f ${log_file}
267	unmount_image
268}
269
270is_rel_path()
271{
272	local path="$1"
273
274	[[ ${path:0:1} != "/" ]]
275}
276
277do_update_kconfig()
278{
279	local kernel_checkout="$1"
280	local kconfig_file="$2"
281
282	rm -f "$kconfig_file" 2> /dev/null
283
284	for config in "${KCONFIG_REL_PATHS[@]}"; do
285		local kconfig_src="${kernel_checkout}/${config}"
286		cat "$kconfig_src" >> "$kconfig_file"
287	done
288}
289
290update_kconfig()
291{
292	local kernel_checkout="$1"
293	local kconfig_file="$2"
294
295	if [[ -f "${kconfig_file}" ]]; then
296		local local_modified="$(stat -c %Y "${kconfig_file}")"
297
298		for config in "${KCONFIG_REL_PATHS[@]}"; do
299			local kconfig_src="${kernel_checkout}/${config}"
300			local src_modified="$(stat -c %Y "${kconfig_src}")"
301			# Only update the config if it has been updated after the
302			# previously cached config was created. This avoids
303			# unnecessarily compiling the kernel and selftests.
304			if [[ "${src_modified}" -gt "${local_modified}" ]]; then
305				do_update_kconfig "$kernel_checkout" "$kconfig_file"
306				# Once we have found one outdated configuration
307				# there is no need to check other ones.
308				break
309			fi
310		done
311	else
312		do_update_kconfig "$kernel_checkout" "$kconfig_file"
313	fi
314}
315
316catch()
317{
318	local exit_code=$1
319	local exit_status_file="${OUTPUT_DIR}/${EXIT_STATUS_FILE}"
320	# This is just a cleanup and the directory may
321	# have already been unmounted. So, don't let this
322	# clobber the error code we intend to return.
323	unmount_image || true
324	if [[ -f "${exit_status_file}" ]]; then
325		exit_code="$(cat ${exit_status_file})"
326	fi
327	exit ${exit_code}
328}
329
330main()
331{
332	local script_dir="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
333	local kernel_checkout=$(realpath "${script_dir}"/../../../../)
334	# By default the script searches for the kernel in the checkout directory but
335	# it also obeys environment variables O= and KBUILD_OUTPUT=
336	local kernel_bzimage="${kernel_checkout}/${BZIMAGE}"
337	local command="${DEFAULT_COMMAND}"
338	local update_image="no"
339	local exit_command="poweroff -f"
340	local debug_shell="no"
341
342	while getopts ':hskid:j:' opt; do
343		case ${opt} in
344		i)
345			update_image="yes"
346			;;
347		d)
348			OUTPUT_DIR="$OPTARG"
349			;;
350		j)
351			NUM_COMPILE_JOBS="$OPTARG"
352			;;
353		s)
354			command=""
355			debug_shell="yes"
356			exit_command="bash"
357			;;
358		h)
359			usage
360			exit 0
361			;;
362		\? )
363			echo "Invalid Option: -$OPTARG"
364			usage
365			exit 1
366			;;
367		: )
368			echo "Invalid Option: -$OPTARG requires an argument"
369			usage
370			exit 1
371			;;
372		esac
373	done
374	shift $((OPTIND -1))
375
376	trap 'catch "$?"' EXIT
377
378	if [[ $# -eq 0  && "${debug_shell}" == "no" ]]; then
379		echo "No command specified, will run ${DEFAULT_COMMAND} in the vm"
380	else
381		command="$@"
382	fi
383
384	local kconfig_file="${OUTPUT_DIR}/latest.config"
385	local make_command="make -j ${NUM_COMPILE_JOBS} KCONFIG_CONFIG=${kconfig_file}"
386
387	# Figure out where the kernel is being built.
388	# O takes precedence over KBUILD_OUTPUT.
389	if [[ "${O:=""}" != "" ]]; then
390		if is_rel_path "${O}"; then
391			O="$(realpath "${PWD}/${O}")"
392		fi
393		kernel_bzimage="${O}/${BZIMAGE}"
394		make_command="${make_command} O=${O}"
395	elif [[ "${KBUILD_OUTPUT:=""}" != "" ]]; then
396		if is_rel_path "${KBUILD_OUTPUT}"; then
397			KBUILD_OUTPUT="$(realpath "${PWD}/${KBUILD_OUTPUT}")"
398		fi
399		kernel_bzimage="${KBUILD_OUTPUT}/${BZIMAGE}"
400		make_command="${make_command} KBUILD_OUTPUT=${KBUILD_OUTPUT}"
401	fi
402
403	populate_url_map
404
405	local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
406	local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
407
408	echo "Output directory: ${OUTPUT_DIR}"
409
410	mkdir -p "${OUTPUT_DIR}"
411	mkdir -p "${mount_dir}"
412	update_kconfig "${kernel_checkout}" "${kconfig_file}"
413
414	recompile_kernel "${kernel_checkout}" "${make_command}"
415
416	if [[ "${update_image}" == "no" && ! -f "${rootfs_img}" ]]; then
417		echo "rootfs image not found in ${rootfs_img}"
418		update_image="yes"
419	fi
420
421	if [[ "${update_image}" == "yes" ]]; then
422		create_vm_image
423	fi
424
425	update_selftests "${kernel_checkout}" "${make_command}"
426	update_init_script "${command}" "${exit_command}"
427	run_vm "${kernel_bzimage}"
428	if [[ "${command}" != "" ]]; then
429		copy_logs
430		echo "Logs saved in ${OUTPUT_DIR}/${LOG_FILE}"
431	fi
432}
433
434main "$@"
435