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} 342