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
  9
 10# Kselftest framework requirement - SKIP code is 4
 11ksft_skip=4
 12
 13# log(msg) - write message to kernel log
 14#	msg - insightful words
 15function log() {
 16	echo "$1" > /dev/kmsg
 17}
 18
 19# skip(msg) - testing can't proceed
 20#	msg - explanation
 21function skip() {
 22	log "SKIP: $1"
 23	echo "SKIP: $1" >&2
 24	exit $ksft_skip
 25}
 26
 27# root test
 28function is_root() {
 29	uid=$(id -u)
 30	if [ $uid -ne 0 ]; then
 31		echo "skip all tests: must be run as root" >&2
 32		exit $ksft_skip
 33	fi
 34}
 35
 36# die(msg) - game over, man
 37#	msg - dying words
 38function die() {
 39	log "ERROR: $1"
 40	echo "ERROR: $1" >&2
 41	exit 1
 42}
 43
 44# save existing dmesg so we can detect new content
 45function save_dmesg() {
 46	SAVED_DMESG=$(mktemp --tmpdir -t klp-dmesg-XXXXXX)
 47	dmesg > "$SAVED_DMESG"
 48}
 49
 50# cleanup temporary dmesg file from save_dmesg()
 51function cleanup_dmesg_file() {
 52	rm -f "$SAVED_DMESG"
 53}
 54
 55function push_config() {
 56	DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
 57			awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
 58	FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
 59}
 60
 61function pop_config() {
 62	if [[ -n "$DYNAMIC_DEBUG" ]]; then
 63		echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
 64	fi
 65	if [[ -n "$FTRACE_ENABLED" ]]; then
 66		sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null
 67	fi
 68}
 69
 70function set_dynamic_debug() {
 71        cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
 72		file kernel/livepatch/* +p
 73		func klp_try_switch_task -p
 74		EOF
 75}
 76
 77function set_ftrace_enabled() {
 78	result=$(sysctl -q kernel.ftrace_enabled="$1" 2>&1 && \
 79		 sysctl kernel.ftrace_enabled 2>&1)
 80	echo "livepatch: $result" > /dev/kmsg
 81}
 82
 83function cleanup() {
 84	pop_config
 85	cleanup_dmesg_file
 86}
 87
 88# setup_config - save the current config and set a script exit trap that
 89#		 restores the original config.  Setup the dynamic debug
 90#		 for verbose livepatching output and turn on
 91#		 the ftrace_enabled sysctl.
 92function setup_config() {
 93	is_root
 94	push_config
 95	set_dynamic_debug
 96	set_ftrace_enabled 1
 97	trap cleanup EXIT INT TERM HUP
 98}
 99
100# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
101#		    sleep $RETRY_INTERVAL between attempts
102#	cmd - command and its arguments to run
103function loop_until() {
104	local cmd="$*"
105	local i=0
106	while true; do
107		eval "$cmd" && return 0
108		[[ $((i++)) -eq $MAX_RETRIES ]] && return 1
109		sleep $RETRY_INTERVAL
110	done
111}
112
113function assert_mod() {
114	local mod="$1"
115
116	modprobe --dry-run "$mod" &>/dev/null
117}
118
119function is_livepatch_mod() {
120	local mod="$1"
121
122	if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
123		return 0
124	fi
125
126	return 1
127}
128
129function __load_mod() {
130	local mod="$1"; shift
131
132	local msg="% modprobe $mod $*"
133	log "${msg%% }"
134	ret=$(modprobe "$mod" "$@" 2>&1)
135	if [[ "$ret" != "" ]]; then
136		die "$ret"
137	fi
138
139	# Wait for module in sysfs ...
140	loop_until '[[ -e "/sys/module/$mod" ]]' ||
141		die "failed to load module $mod"
142}
143
144
145# load_mod(modname, params) - load a kernel module
146#	modname - module name to load
147#	params  - module parameters to pass to modprobe
148function load_mod() {
149	local mod="$1"; shift
150
151	assert_mod "$mod" ||
152		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
153
154	is_livepatch_mod "$mod" &&
155		die "use load_lp() to load the livepatch module $mod"
156
157	__load_mod "$mod" "$@"
158}
159
160# load_lp_nowait(modname, params) - load a kernel module with a livepatch
161#			but do not wait on until the transition finishes
162#	modname - module name to load
163#	params  - module parameters to pass to modprobe
164function load_lp_nowait() {
165	local mod="$1"; shift
166
167	assert_mod "$mod" ||
168		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
169
170	is_livepatch_mod "$mod" ||
171		die "module $mod is not a livepatch"
172
173	__load_mod "$mod" "$@"
174
175	# Wait for livepatch in sysfs ...
176	loop_until '[[ -e "/sys/kernel/livepatch/$mod" ]]' ||
177		die "failed to load module $mod (sysfs)"
178}
179
180# load_lp(modname, params) - load a kernel module with a livepatch
181#	modname - module name to load
182#	params  - module parameters to pass to modprobe
183function load_lp() {
184	local mod="$1"; shift
185
186	load_lp_nowait "$mod" "$@"
187
188	# Wait until the transition finishes ...
189	loop_until 'grep -q '^0$' /sys/kernel/livepatch/$mod/transition' ||
190		die "failed to complete transition"
191}
192
193# load_failing_mod(modname, params) - load a kernel module, expect to fail
194#	modname - module name to load
195#	params  - module parameters to pass to modprobe
196function load_failing_mod() {
197	local mod="$1"; shift
198
199	local msg="% modprobe $mod $*"
200	log "${msg%% }"
201	ret=$(modprobe "$mod" "$@" 2>&1)
202	if [[ "$ret" == "" ]]; then
203		die "$mod unexpectedly loaded"
204	fi
205	log "$ret"
206}
207
208# unload_mod(modname) - unload a kernel module
209#	modname - module name to unload
210function unload_mod() {
211	local mod="$1"
212
213	# Wait for module reference count to clear ...
214	loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
215		die "failed to unload module $mod (refcnt)"
216
217	log "% rmmod $mod"
218	ret=$(rmmod "$mod" 2>&1)
219	if [[ "$ret" != "" ]]; then
220		die "$ret"
221	fi
222
223	# Wait for module in sysfs ...
224	loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
225		die "failed to unload module $mod (/sys/module)"
226}
227
228# unload_lp(modname) - unload a kernel module with a livepatch
229#	modname - module name to unload
230function unload_lp() {
231	unload_mod "$1"
232}
233
234# disable_lp(modname) - disable a livepatch
235#	modname - module name to unload
236function disable_lp() {
237	local mod="$1"
238
239	log "% echo 0 > /sys/kernel/livepatch/$mod/enabled"
240	echo 0 > /sys/kernel/livepatch/"$mod"/enabled
241
242	# Wait until the transition finishes and the livepatch gets
243	# removed from sysfs...
244	loop_until '[[ ! -e "/sys/kernel/livepatch/$mod" ]]' ||
245		die "failed to disable livepatch $mod"
246}
247
248# set_pre_patch_ret(modname, pre_patch_ret)
249#	modname - module name to set
250#	pre_patch_ret - new pre_patch_ret value
251function set_pre_patch_ret {
252	local mod="$1"; shift
253	local ret="$1"
254
255	log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
256	echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
257
258	# Wait for sysfs value to hold ...
259	loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
260		die "failed to set pre_patch_ret parameter for $mod module"
261}
262
263function start_test {
264	local test="$1"
265
266	save_dmesg
267	echo -n "TEST: $test ... "
268	log "===== TEST: $test ====="
269}
270
271# check_result() - verify dmesg output
272#	TODO - better filter, out of order msgs, etc?
273function check_result {
274	local expect="$*"
275	local result
276
277	# Note: when comparing dmesg output, the kernel log timestamps
278	# help differentiate repeated testing runs.  Remove them with a
279	# post-comparison sed filter.
280
281	result=$(dmesg | comm -13 "$SAVED_DMESG" - | \
282		 grep -e 'livepatch:' -e 'test_klp' | \
283		 grep -v '\(tainting\|taints\) kernel' | \
284		 sed 's/^\[[ 0-9.]*\] //')
285
286	if [[ "$expect" == "$result" ]] ; then
287		echo "ok"
288	else
289		echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
290		die "livepatch kselftest(s) failed"
291	fi
292
293	cleanup_dmesg_file
294}