tools/testing/selftests/livepatch/functions.sh

   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
   7 MAX_RETRIES=600
   8 RETRY_INTERVAL=".1"     # seconds
   9
  10 # Kselftest framework requirement - SKIP code is 4
  11 ksft_skip=4
  12
  13 # log(msg) - write message to kernel log
  14 #       msg - insightful words
  15 function log() {
  16         echo "$1" > /dev/kmsg
  17 }
  18
  19 # skip(msg) - testing can't proceed
  20 #       msg - explanation
  21 function skip() {
  22         log "SKIP: $1"
  23         echo "SKIP: $1" >&2
  24         exit $ksft_skip
  25 }
  26
  27 # root test
  28 function is_root() {
  29         uid=$(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
  38 function die() {
  39         log "ERROR: $1"
  40         echo "ERROR: $1" >&2
  41         exit 1
  42 }
  43
  44 function push_config() {
  45         DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
  46                         awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
  47         FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
  48 }
  49
  50 function pop_config() {
  51         if [[ -n "$DYNAMIC_DEBUG" ]]; then
  52                 echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
  53         fi
  54         if [[ -n "$FTRACE_ENABLED" ]]; then
  55                 sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null
  56         fi
  57 }
  58
  59 function set_dynamic_debug() {
  60         cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
  61                 file kernel/livepatch/* +p
  62                 func klp_try_switch_task -p
  63                 EOF
  64 }
  65
  66 function set_ftrace_enabled() {
  67         result=$(sysctl kernel.ftrace_enabled="$1" 2>&1 | paste --serial --delimiters=' ')
  68         echo "livepatch: $result" > /dev/kmsg
  69 }
  70
  71 # setup_config - save the current config and set a script exit trap that
  72 #                restores the original config.  Setup the dynamic debug
  73 #                for verbose livepatching output and turn on
  74 #                the ftrace_enabled sysctl.
  75 function setup_config() {
  76         is_root
  77         push_config
  78         set_dynamic_debug
  79         set_ftrace_enabled 1
  80         trap pop_config EXIT INT TERM HUP
  81 }
  82
  83 # loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
  84 #                   sleep $RETRY_INTERVAL between attempts
  85 #       cmd - command and its arguments to run
  86 function loop_until() {
  87         local cmd="$*"
  88         local i=0
  89         while true; do
  90                 eval "$cmd" && return 0
  91                 [[ $((i++)) -eq $MAX_RETRIES ]] && return 1
  92                 sleep $RETRY_INTERVAL
  93         done
  94 }
  95
  96 function assert_mod() {
  97         local mod="$1"
  98
  99         modprobe --dry-run "$mod" &>/dev/null
 100 }
 101
 102 function is_livepatch_mod() {
 103         local mod="$1"
 104
 105         if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
 106                 return 0
 107         fi
 108
 109         return 1
 110 }
 111
 112 function __load_mod() {
 113         local mod="$1"; shift
 114
 115         local msg="% modprobe $mod $*"
 116         log "${msg%% }"
 117         ret=$(modprobe "$mod" "$@" 2>&1)
 118         if [[ "$ret" != "" ]]; then
 119                 die "$ret"
 120         fi
 121
 122         # Wait for module in sysfs ...
 123         loop_until '[[ -e "/sys/module/$mod" ]]' ||
 124                 die "failed to load module $mod"
 125 }
 126
 127
 128 # load_mod(modname, params) - load a kernel module
 129 #       modname - module name to load
 130 #       params  - module parameters to pass to modprobe
 131 function load_mod() {
 132         local mod="$1"; shift
 133
 134         assert_mod "$mod" ||
 135                 skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
 136
 137         is_livepatch_mod "$mod" &&
 138                 die "use load_lp() to load the livepatch module $mod"
 139
 140         __load_mod "$mod" "$@"
 141 }
 142
 143 # load_lp_nowait(modname, params) - load a kernel module with a livepatch
 144 #                       but do not wait on until the transition finishes
 145 #       modname - module name to load
 146 #       params  - module parameters to pass to modprobe
 147 function load_lp_nowait() {
 148         local mod="$1"; shift
 149
 150         assert_mod "$mod" ||
 151                 skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
 152
 153         is_livepatch_mod "$mod" ||
 154                 die "module $mod is not a livepatch"
 155
 156         __load_mod "$mod" "$@"
 157
 158         # Wait for livepatch in sysfs ...
 159         loop_until '[[ -e "/sys/kernel/livepatch/$mod" ]]' ||
 160                 die "failed to load module $mod (sysfs)"
 161 }
 162
 163 # load_lp(modname, params) - load a kernel module with a livepatch
 164 #       modname - module name to load
 165 #       params  - module parameters to pass to modprobe
 166 function load_lp() {
 167         local mod="$1"; shift
 168
 169         load_lp_nowait "$mod" "$@"
 170
 171         # Wait until the transition finishes ...
 172         loop_until 'grep -q '^0$' /sys/kernel/livepatch/$mod/transition' ||
 173                 die "failed to complete transition"
 174 }
 175
 176 # load_failing_mod(modname, params) - load a kernel module, expect to fail
 177 #       modname - module name to load
 178 #       params  - module parameters to pass to modprobe
 179 function load_failing_mod() {
 180         local mod="$1"; shift
 181
 182         local msg="% modprobe $mod $*"
 183         log "${msg%% }"
 184         ret=$(modprobe "$mod" "$@" 2>&1)
 185         if [[ "$ret" == "" ]]; then
 186                 die "$mod unexpectedly loaded"
 187         fi
 188         log "$ret"
 189 }
 190
 191 # unload_mod(modname) - unload a kernel module
 192 #       modname - module name to unload
 193 function unload_mod() {
 194         local mod="$1"
 195
 196         # Wait for module reference count to clear ...
 197         loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
 198                 die "failed to unload module $mod (refcnt)"
 199
 200         log "% rmmod $mod"
 201         ret=$(rmmod "$mod" 2>&1)
 202         if [[ "$ret" != "" ]]; then
 203                 die "$ret"
 204         fi
 205
 206         # Wait for module in sysfs ...
 207         loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
 208                 die "failed to unload module $mod (/sys/module)"
 209 }
 210
 211 # unload_lp(modname) - unload a kernel module with a livepatch
 212 #       modname - module name to unload
 213 function unload_lp() {
 214         unload_mod "$1"
 215 }
 216
 217 # disable_lp(modname) - disable a livepatch
 218 #       modname - module name to unload
 219 function disable_lp() {
 220         local mod="$1"
 221
 222         log "% echo 0 > /sys/kernel/livepatch/$mod/enabled"
 223         echo 0 > /sys/kernel/livepatch/"$mod"/enabled
 224
 225         # Wait until the transition finishes and the livepatch gets
 226         # removed from sysfs...
 227         loop_until '[[ ! -e "/sys/kernel/livepatch/$mod" ]]' ||
 228                 die "failed to disable livepatch $mod"
 229 }
 230
 231 # set_pre_patch_ret(modname, pre_patch_ret)
 232 #       modname - module name to set
 233 #       pre_patch_ret - new pre_patch_ret value
 234 function set_pre_patch_ret {
 235         local mod="$1"; shift
 236         local ret="$1"
 237
 238         log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
 239         echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
 240
 241         # Wait for sysfs value to hold ...
 242         loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
 243                 die "failed to set pre_patch_ret parameter for $mod module"
 244 }
 245
 246 # check_result() - verify dmesg output
 247 #       TODO - better filter, out of order msgs, etc?
 248 function check_result {
 249         local expect="$*"
 250         local result
 251
 252         result=$(dmesg | grep -v 'tainting' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
 253
 254         if [[ "$expect" == "$result" ]] ; then
 255                 echo "ok"
 256         else
 257                 echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
 258                 die "livepatch kselftest(s) failed"
 259         fi
 260 }