1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
  4
  5# Shell functions for the rest of the scripts.
  6
  7MAX_RETRIES=600
  8RETRY_INTERVAL=".1"	# seconds
  9SYSFS_KERNEL_DIR="/sys/kernel"
 10SYSFS_KLP_DIR="$SYSFS_KERNEL_DIR/livepatch"
 11SYSFS_DEBUG_DIR="$SYSFS_KERNEL_DIR/debug"
 12SYSFS_KPROBES_DIR="$SYSFS_DEBUG_DIR/kprobes"
 13
 14# Kselftest framework requirement - SKIP code is 4
 15ksft_skip=4
 16
 17# log(msg) - write message to kernel log
 18#	msg - insightful words
 19function log() {
 20	echo "$1" > /dev/kmsg
 21}
 22
 23# skip(msg) - testing can't proceed
 24#	msg - explanation
 25function skip() {
 26	log "SKIP: $1"
 27	echo "SKIP: $1" >&2
 28	exit $ksft_skip
 29}
 30
 31# root test
 32function is_root() {
 33	uid=$(id -u)
 34	if [ $uid -ne 0 ]; then
 35		echo "skip all tests: must be run as root" >&2
 36		exit $ksft_skip
 37	fi
 38}
 39
 40# Check if we can compile the modules before loading them
 41function has_kdir() {
 42	if [ -z "$KDIR" ]; then
 43		KDIR="/lib/modules/$(uname -r)/build"
 44	fi
 45
 46	if [ ! -d "$KDIR" ]; then
 47		echo "skip all tests: KDIR ($KDIR) not available to compile modules."
 48		exit $ksft_skip
 49	fi
 50}
 51
 52# die(msg) - game over, man
 53#	msg - dying words
 54function die() {
 55	log "ERROR: $1"
 56	echo "ERROR: $1" >&2
 57	exit 1
 58}
 59
 60function push_config() {
 61	DYNAMIC_DEBUG=$(grep '^kernel/livepatch' "$SYSFS_DEBUG_DIR/dynamic_debug/control" | \
 62			awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
 63	FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
 64	KPROBE_ENABLED=$(cat "$SYSFS_KPROBES_DIR/enabled")
 65}
 66
 67function pop_config() {
 68	if [[ -n "$DYNAMIC_DEBUG" ]]; then
 69		echo -n "$DYNAMIC_DEBUG" > "$SYSFS_DEBUG_DIR/dynamic_debug/control"
 70	fi
 71	if [[ -n "$FTRACE_ENABLED" ]]; then
 72		sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null
 73	fi
 74	if [[ -n "$KPROBE_ENABLED" ]]; then
 75		echo "$KPROBE_ENABLED" > "$SYSFS_KPROBES_DIR/enabled"
 76	fi
 77}
 78
 79function set_dynamic_debug() {
 80        cat <<-EOF > "$SYSFS_DEBUG_DIR/dynamic_debug/control"
 81		file kernel/livepatch/* +p
 82		func klp_try_switch_task -p
 83		EOF
 84}
 85
 86function set_ftrace_enabled() {
 87	local can_fail=0
 88	if [[ "$1" == "--fail" ]] ; then
 89		can_fail=1
 90		shift
 91	fi
 92
 93	local err=$(sysctl -q kernel.ftrace_enabled="$1" 2>&1)
 94	local result=$(sysctl --values kernel.ftrace_enabled)
 95
 96	if [[ "$result" != "$1" ]] ; then
 97		if [[ $can_fail -eq 1 ]] ; then
 98			echo "livepatch: $err" | sed 's#/proc/sys/kernel/#kernel.#' > /dev/kmsg
 99			return
100		fi
101
102		skip "failed to set kernel.ftrace_enabled = $1"
103	fi
104
105	echo "livepatch: kernel.ftrace_enabled = $result" > /dev/kmsg
106}
107
108function cleanup() {
109	pop_config
110}
111
112# setup_config - save the current config and set a script exit trap that
113#		 restores the original config.  Setup the dynamic debug
114#		 for verbose livepatching output and turn on
115#		 the ftrace_enabled sysctl.
116function setup_config() {
117	is_root
118	has_kdir
119	push_config
120	set_dynamic_debug
121	set_ftrace_enabled 1
122	trap cleanup EXIT INT TERM HUP
123}
124
125# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
126#		    sleep $RETRY_INTERVAL between attempts
127#	cmd - command and its arguments to run
128function loop_until() {
129	local cmd="$*"
130	local i=0
131	while true; do
132		eval "$cmd" && return 0
133		[[ $((i++)) -eq $MAX_RETRIES ]] && return 1
134		sleep $RETRY_INTERVAL
135	done
136}
137
138function is_livepatch_mod() {
139	local mod="$1"
140
141	if [[ ! -f "test_modules/$mod.ko" ]]; then
142		die "Can't find \"test_modules/$mod.ko\", try \"make\""
143	fi
144
145	if [[ $(modinfo "test_modules/$mod.ko" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
146		return 0
147	fi
148
149	return 1
150}
151
152function __load_mod() {
153	local mod="$1"; shift
154
155	local msg="% insmod test_modules/$mod.ko $*"
156	log "${msg%% }"
157	ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1)
158	if [[ "$ret" != "" ]]; then
159		die "$ret"
160	fi
161
162	# Wait for module in sysfs ...
163	loop_until '[[ -e "/sys/module/$mod" ]]' ||
164		die "failed to load module $mod"
165}
166
167
168# load_mod(modname, params) - load a kernel module
169#	modname - module name to load
170#	params  - module parameters to pass to insmod
171function load_mod() {
172	local mod="$1"; shift
173
174	is_livepatch_mod "$mod" &&
175		die "use load_lp() to load the livepatch module $mod"
176
177	__load_mod "$mod" "$@"
178}
179
180# load_lp_nowait(modname, params) - load a kernel module with a livepatch
181#			but do not wait on until the transition finishes
182#	modname - module name to load
183#	params  - module parameters to pass to insmod
184function load_lp_nowait() {
185	local mod="$1"; shift
186
187	is_livepatch_mod "$mod" ||
188		die "module $mod is not a livepatch"
189
190	__load_mod "$mod" "$@"
191
192	# Wait for livepatch in sysfs ...
193	loop_until '[[ -e "$SYSFS_KLP_DIR/$mod" ]]' ||
194		die "failed to load module $mod (sysfs)"
195}
196
197# load_lp(modname, params) - load a kernel module with a livepatch
198#	modname - module name to load
199#	params  - module parameters to pass to insmod
200function load_lp() {
201	local mod="$1"; shift
202
203	load_lp_nowait "$mod" "$@"
204
205	# Wait until the transition finishes ...
206	loop_until 'grep -q '^0$' $SYSFS_KLP_DIR/$mod/transition' ||
207		die "failed to complete transition"
208}
209
210# load_failing_mod(modname, params) - load a kernel module, expect to fail
211#	modname - module name to load
212#	params  - module parameters to pass to insmod
213function load_failing_mod() {
214	local mod="$1"; shift
215
216	local msg="% insmod test_modules/$mod.ko $*"
217	log "${msg%% }"
218	ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1)
219	if [[ "$ret" == "" ]]; then
220		die "$mod unexpectedly loaded"
221	fi
222	log "$ret"
223}
224
225# unload_mod(modname) - unload a kernel module
226#	modname - module name to unload
227function unload_mod() {
228	local mod="$1"
229
230	# Wait for module reference count to clear ...
231	loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
232		die "failed to unload module $mod (refcnt)"
233
234	log "% rmmod $mod"
235	ret=$(rmmod "$mod" 2>&1)
236	if [[ "$ret" != "" ]]; then
237		die "$ret"
238	fi
239
240	# Wait for module in sysfs ...
241	loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
242		die "failed to unload module $mod (/sys/module)"
243}
244
245# unload_lp(modname) - unload a kernel module with a livepatch
246#	modname - module name to unload
247function unload_lp() {
248	unload_mod "$1"
249}
250
251# disable_lp(modname) - disable a livepatch
252#	modname - module name to unload
253function disable_lp() {
254	local mod="$1"
255
256	log "% echo 0 > $SYSFS_KLP_DIR/$mod/enabled"
257	echo 0 > "$SYSFS_KLP_DIR/$mod/enabled"
258
259	# Wait until the transition finishes and the livepatch gets
260	# removed from sysfs...
261	loop_until '[[ ! -e "$SYSFS_KLP_DIR/$mod" ]]' ||
262		die "failed to disable livepatch $mod"
263}
264
265# set_pre_patch_ret(modname, pre_patch_ret)
266#	modname - module name to set
267#	pre_patch_ret - new pre_patch_ret value
268function set_pre_patch_ret {
269	local mod="$1"; shift
270	local ret="$1"
271
272	log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
273	echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
274
275	# Wait for sysfs value to hold ...
276	loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
277		die "failed to set pre_patch_ret parameter for $mod module"
278}
279
280function start_test {
281	local test="$1"
282
283	# Dump something unique into the dmesg log, then stash the entry
284	# in LAST_DMESG.  The check_result() function will use it to
285	# find new kernel messages since the test started.
286	local last_dmesg_msg="livepatch kselftest timestamp: $(date --rfc-3339=ns)"
287	log "$last_dmesg_msg"
288	loop_until 'dmesg | grep -q "$last_dmesg_msg"' ||
289		die "buffer busy? can't find canary dmesg message: $last_dmesg_msg"
290	LAST_DMESG=$(dmesg | grep "$last_dmesg_msg")
291
292	echo -n "TEST: $test ... "
293	log "===== TEST: $test ====="
294}
295
296# check_result() - verify dmesg output
297#	TODO - better filter, out of order msgs, etc?
298function check_result {
299	local expect="$*"
300	local result
301
302	# Test results include any new dmesg entry since LAST_DMESG, then:
303	# - include lines matching keywords
304	# - exclude lines matching keywords
305	# - filter out dmesg timestamp prefixes
306	result=$(dmesg | awk -v last_dmesg="$LAST_DMESG" 'p; $0 == last_dmesg { p=1 }' | \
307		 grep -e 'livepatch:' -e 'test_klp' | \
308		 grep -v '\(tainting\|taints\) kernel' | \
309		 sed 's/^\[[ 0-9.]*\] //')
310
311	if [[ "$expect" == "$result" ]] ; then
312		echo "ok"
313	elif [[ "$result" == "" ]] ; then
314		echo -e "not ok\n\nbuffer overrun? can't find canary dmesg entry: $LAST_DMESG\n"
315		die "livepatch kselftest(s) failed"
316	else
317		echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
318		die "livepatch kselftest(s) failed"
319	fi
320}
321
322# check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs
323# path permissions
324#	modname - livepatch module creating the sysfs interface
325#	rel_path - relative path of the sysfs interface
326#	expected_rights - expected access rights
327function check_sysfs_rights() {
328	local mod="$1"; shift
329	local rel_path="$1"; shift
330	local expected_rights="$1"; shift
331
332	local path="$SYSFS_KLP_DIR/$mod/$rel_path"
333	local rights=$(/bin/stat --format '%A' "$path")
334	if test "$rights" != "$expected_rights" ; then
335		die "Unexpected access rights of $path: $expected_rights vs. $rights"
336	fi
337}
338
339# check_sysfs_value(modname, rel_path, expected_value) - check sysfs value
340#	modname - livepatch module creating the sysfs interface
341#	rel_path - relative path of the sysfs interface
342#	expected_value - expected value read from the file
343function check_sysfs_value() {
344	local mod="$1"; shift
345	local rel_path="$1"; shift
346	local expected_value="$1"; shift
347
348	local path="$SYSFS_KLP_DIR/$mod/$rel_path"
349	local value=`cat $path`
350	if test "$value" != "$expected_value" ; then
351		die "Unexpected value in $path: $expected_value vs. $value"
352	fi
353}