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# log(msg) - write message to kernel log
 11#	msg - insightful words
 12function log() {
 13	echo "$1" > /dev/kmsg
 14}
 15
 16# skip(msg) - testing can't proceed
 17#	msg - explanation
 18function skip() {
 19	log "SKIP: $1"
 20	echo "SKIP: $1" >&2
 21	exit 4
 22}
 23
 24# die(msg) - game over, man
 25#	msg - dying words
 26function die() {
 27	log "ERROR: $1"
 28	echo "ERROR: $1" >&2
 29	exit 1
 30}
 31
 32function push_dynamic_debug() {
 33        DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
 34                awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
 35}
 36
 37function pop_dynamic_debug() {
 38	if [[ -n "$DYNAMIC_DEBUG" ]]; then
 39		echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
 40	fi
 41}
 42
 43# set_dynamic_debug() - save the current dynamic debug config and tweak
 44# 			it for the self-tests.  Set a script exit trap
 45#			that restores the original config.
 46function set_dynamic_debug() {
 47        push_dynamic_debug
 48        trap pop_dynamic_debug EXIT INT TERM HUP
 49        cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
 50		file kernel/livepatch/* +p
 51		func klp_try_switch_task -p
 52		EOF
 53}
 54
 55# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
 56#		    sleep $RETRY_INTERVAL between attempts
 57#	cmd - command and its arguments to run
 58function loop_until() {
 59	local cmd="$*"
 60	local i=0
 61	while true; do
 62		eval "$cmd" && return 0
 63		[[ $((i++)) -eq $MAX_RETRIES ]] && return 1
 64		sleep $RETRY_INTERVAL
 65	done
 66}
 67
 68function assert_mod() {
 69	local mod="$1"
 70
 71	modprobe --dry-run "$mod" &>/dev/null
 72}
 73
 74function is_livepatch_mod() {
 75	local mod="$1"
 76
 77	if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
 78		return 0
 79	fi
 80
 81	return 1
 82}
 83
 84function __load_mod() {
 85	local mod="$1"; shift
 86
 87	local msg="% modprobe $mod $*"
 88	log "${msg%% }"
 89	ret=$(modprobe "$mod" "$@" 2>&1)
 90	if [[ "$ret" != "" ]]; then
 91		die "$ret"
 92	fi
 93
 94	# Wait for module in sysfs ...
 95	loop_until '[[ -e "/sys/module/$mod" ]]' ||
 96		die "failed to load module $mod"
 97}
 98
 99
100# load_mod(modname, params) - load a kernel module
101#	modname - module name to load
102#	params  - module parameters to pass to modprobe
103function load_mod() {
104	local mod="$1"; shift
105
106	assert_mod "$mod" ||
107		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
108
109	is_livepatch_mod "$mod" &&
110		die "use load_lp() to load the livepatch module $mod"
111
112	__load_mod "$mod" "$@"
113}
114
115# load_lp_nowait(modname, params) - load a kernel module with a livepatch
116#			but do not wait on until the transition finishes
117#	modname - module name to load
118#	params  - module parameters to pass to modprobe
119function load_lp_nowait() {
120	local mod="$1"; shift
121
122	assert_mod "$mod" ||
123		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
124
125	is_livepatch_mod "$mod" ||
126		die "module $mod is not a livepatch"
127
128	__load_mod "$mod" "$@"
129
130	# Wait for livepatch in sysfs ...
131	loop_until '[[ -e "/sys/kernel/livepatch/$mod" ]]' ||
132		die "failed to load module $mod (sysfs)"
133}
134
135# load_lp(modname, params) - load a kernel module with a livepatch
136#	modname - module name to load
137#	params  - module parameters to pass to modprobe
138function load_lp() {
139	local mod="$1"; shift
140
141	load_lp_nowait "$mod" "$@"
142
143	# Wait until the transition finishes ...
144	loop_until 'grep -q '^0$' /sys/kernel/livepatch/$mod/transition' ||
145		die "failed to complete transition"
146}
147
148# load_failing_mod(modname, params) - load a kernel module, expect to fail
149#	modname - module name to load
150#	params  - module parameters to pass to modprobe
151function load_failing_mod() {
152	local mod="$1"; shift
153
154	local msg="% modprobe $mod $*"
155	log "${msg%% }"
156	ret=$(modprobe "$mod" "$@" 2>&1)
157	if [[ "$ret" == "" ]]; then
158		die "$mod unexpectedly loaded"
159	fi
160	log "$ret"
161}
162
163# unload_mod(modname) - unload a kernel module
164#	modname - module name to unload
165function unload_mod() {
166	local mod="$1"
167
168	# Wait for module reference count to clear ...
169	loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
170		die "failed to unload module $mod (refcnt)"
171
172	log "% rmmod $mod"
173	ret=$(rmmod "$mod" 2>&1)
174	if [[ "$ret" != "" ]]; then
175		die "$ret"
176	fi
177
178	# Wait for module in sysfs ...
179	loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
180		die "failed to unload module $mod (/sys/module)"
181}
182
183# unload_lp(modname) - unload a kernel module with a livepatch
184#	modname - module name to unload
185function unload_lp() {
186	unload_mod "$1"
187}
188
189# disable_lp(modname) - disable a livepatch
190#	modname - module name to unload
191function disable_lp() {
192	local mod="$1"
193
194	log "% echo 0 > /sys/kernel/livepatch/$mod/enabled"
195	echo 0 > /sys/kernel/livepatch/"$mod"/enabled
196
197	# Wait until the transition finishes and the livepatch gets
198	# removed from sysfs...
199	loop_until '[[ ! -e "/sys/kernel/livepatch/$mod" ]]' ||
200		die "failed to disable livepatch $mod"
201}
202
203# set_pre_patch_ret(modname, pre_patch_ret)
204#	modname - module name to set
205#	pre_patch_ret - new pre_patch_ret value
206function set_pre_patch_ret {
207	local mod="$1"; shift
208	local ret="$1"
209
210	log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
211	echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
212
213	# Wait for sysfs value to hold ...
214	loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
215		die "failed to set pre_patch_ret parameter for $mod module"
216}
217
218# check_result() - verify dmesg output
219#	TODO - better filter, out of order msgs, etc?
220function check_result {
221	local expect="$*"
222	local result
223
224	result=$(dmesg | grep -v 'tainting' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
225
226	if [[ "$expect" == "$result" ]] ; then
227		echo "ok"
228	else
229		echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
230		die "livepatch kselftest(s) failed"
231	fi
232}