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