tools/testing/selftests/firmware/fw_fallback.sh

   1 #!/bin/sh
   2 # SPDX-License-Identifier: GPL-2.0
   3 # This validates that the kernel will fall back to using the fallback mechanism
   4 # to load firmware it can't find on disk itself. We must request a firmware
   5 # that the kernel won't find, and any installed helper (e.g. udev) also
   6 # won't find so that we can do the load ourself manually.
   7 set -e
   8
   9 modprobe test_firmware
  10
  11 DIR=/sys/devices/virtual/misc/test_firmware
  12
  13 # CONFIG_FW_LOADER_USER_HELPER has a sysfs class under /sys/class/firmware/
  14 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
  15 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
  16 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; else echo no; fi)
  17
  18 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
  19        OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
  20 else
  21         echo "usermode helper disabled so ignoring test"
  22         exit 0
  23 fi
  24
  25 FWPATH=$(mktemp -d)
  26 FW="$FWPATH/test-firmware.bin"
  27
  28 test_finish()
  29 {
  30         echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
  31         rm -f "$FW"
  32         rmdir "$FWPATH"
  33 }
  34
  35 load_fw()
  36 {
  37         local name="$1"
  38         local file="$2"
  39
  40         # This will block until our load (below) has finished.
  41         echo -n "$name" >"$DIR"/trigger_request &
  42
  43         # Give kernel a chance to react.
  44         local timeout=10
  45         while [ ! -e "$DIR"/"$name"/loading ]; do
  46                 sleep 0.1
  47                 timeout=$(( $timeout - 1 ))
  48                 if [ "$timeout" -eq 0 ]; then
  49                         echo "$0: firmware interface never appeared" >&2
  50                         exit 1
  51                 fi
  52         done
  53
  54         echo 1 >"$DIR"/"$name"/loading
  55         cat "$file" >"$DIR"/"$name"/data
  56         echo 0 >"$DIR"/"$name"/loading
  57
  58         # Wait for request to finish.
  59         wait
  60 }
  61
  62 load_fw_cancel()
  63 {
  64         local name="$1"
  65         local file="$2"
  66
  67         # This will block until our load (below) has finished.
  68         echo -n "$name" >"$DIR"/trigger_request 2>/dev/null &
  69
  70         # Give kernel a chance to react.
  71         local timeout=10
  72         while [ ! -e "$DIR"/"$name"/loading ]; do
  73                 sleep 0.1
  74                 timeout=$(( $timeout - 1 ))
  75                 if [ "$timeout" -eq 0 ]; then
  76                         echo "$0: firmware interface never appeared" >&2
  77                         exit 1
  78                 fi
  79         done
  80
  81         echo -1 >"$DIR"/"$name"/loading
  82
  83         # Wait for request to finish.
  84         wait
  85 }
  86
  87 load_fw_custom()
  88 {
  89         if [ ! -e "$DIR"/trigger_custom_fallback ]; then
  90                 echo "$0: custom fallback trigger not present, ignoring test" >&2
  91                 return 1
  92         fi
  93
  94         local name="$1"
  95         local file="$2"
  96
  97         echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
  98
  99         # Give kernel a chance to react.
 100         local timeout=10
 101         while [ ! -e "$DIR"/"$name"/loading ]; do
 102                 sleep 0.1
 103                 timeout=$(( $timeout - 1 ))
 104                 if [ "$timeout" -eq 0 ]; then
 105                         echo "$0: firmware interface never appeared" >&2
 106                         exit 1
 107                 fi
 108         done
 109
 110         echo 1 >"$DIR"/"$name"/loading
 111         cat "$file" >"$DIR"/"$name"/data
 112         echo 0 >"$DIR"/"$name"/loading
 113
 114         # Wait for request to finish.
 115         wait
 116         return 0
 117 }
 118
 119
 120 load_fw_custom_cancel()
 121 {
 122         if [ ! -e "$DIR"/trigger_custom_fallback ]; then
 123                 echo "$0: canceling custom fallback trigger not present, ignoring test" >&2
 124                 return 1
 125         fi
 126
 127         local name="$1"
 128         local file="$2"
 129
 130         echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
 131
 132         # Give kernel a chance to react.
 133         local timeout=10
 134         while [ ! -e "$DIR"/"$name"/loading ]; do
 135                 sleep 0.1
 136                 timeout=$(( $timeout - 1 ))
 137                 if [ "$timeout" -eq 0 ]; then
 138                         echo "$0: firmware interface never appeared" >&2
 139                         exit 1
 140                 fi
 141         done
 142
 143         echo -1 >"$DIR"/"$name"/loading
 144
 145         # Wait for request to finish.
 146         wait
 147         return 0
 148 }
 149
 150 load_fw_fallback_with_child()
 151 {
 152         local name="$1"
 153         local file="$2"
 154
 155         # This is the value already set but we want to be explicit
 156         echo 4 >/sys/class/firmware/timeout
 157
 158         sleep 1 &
 159         SECONDS_BEFORE=$(date +%s)
 160         echo -n "$name" >"$DIR"/trigger_request 2>/dev/null
 161         SECONDS_AFTER=$(date +%s)
 162         SECONDS_DELTA=$(($SECONDS_AFTER - $SECONDS_BEFORE))
 163         if [ "$SECONDS_DELTA" -lt 4 ]; then
 164                 RET=1
 165         else
 166                 RET=0
 167         fi
 168         wait
 169         return $RET
 170 }
 171
 172 trap "test_finish" EXIT
 173
 174 # This is an unlikely real-world firmware content. :)
 175 echo "ABCD0123" >"$FW"
 176 NAME=$(basename "$FW")
 177
 178 test_syfs_timeout()
 179 {
 180         DEVPATH="$DIR"/"nope-$NAME"/loading
 181
 182         # Test failure when doing nothing (timeout works).
 183         echo -n 2 >/sys/class/firmware/timeout
 184         echo -n "nope-$NAME" >"$DIR"/trigger_request 2>/dev/null &
 185
 186         # Give the kernel some time to load the loading file, must be less
 187         # than the timeout above.
 188         sleep 1
 189         if [ ! -f $DEVPATH ]; then
 190                 echo "$0: fallback mechanism immediately cancelled"
 191                 echo ""
 192                 echo "The file never appeared: $DEVPATH"
 193                 echo ""
 194                 echo "This might be a distribution udev rule setup by your distribution"
 195                 echo "to immediately cancel all fallback requests, this must be"
 196                 echo "removed before running these tests. To confirm look for"
 197                 echo "a firmware rule like /lib/udev/rules.d/50-firmware.rules"
 198                 echo "and see if you have something like this:"
 199                 echo ""
 200                 echo "SUBSYSTEM==\"firmware\", ACTION==\"add\", ATTR{loading}=\"-1\""
 201                 echo ""
 202                 echo "If you do remove this file or comment out this line before"
 203                 echo "proceeding with these tests."
 204                 exit 1
 205         fi
 206
 207         if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 208                 echo "$0: firmware was not expected to match" >&2
 209                 exit 1
 210         else
 211                 echo "$0: timeout works"
 212         fi
 213 }
 214
 215 run_sysfs_main_tests()
 216 {
 217         test_syfs_timeout
 218         # Put timeout high enough for us to do work but not so long that failures
 219         # slow down this test too much.
 220         echo 4 >/sys/class/firmware/timeout
 221
 222         # Load this script instead of the desired firmware.
 223         load_fw "$NAME" "$0"
 224         if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 225                 echo "$0: firmware was not expected to match" >&2
 226                 exit 1
 227         else
 228                 echo "$0: firmware comparison works"
 229         fi
 230
 231         # Do a proper load, which should work correctly.
 232         load_fw "$NAME" "$FW"
 233         if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 234                 echo "$0: firmware was not loaded" >&2
 235                 exit 1
 236         else
 237                 echo "$0: fallback mechanism works"
 238         fi
 239
 240         load_fw_cancel "nope-$NAME" "$FW"
 241         if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 242                 echo "$0: firmware was expected to be cancelled" >&2
 243                 exit 1
 244         else
 245                 echo "$0: cancelling fallback mechanism works"
 246         fi
 247
 248         set +e
 249         load_fw_fallback_with_child "nope-signal-$NAME" "$FW"
 250         if [ "$?" -eq 0 ]; then
 251                 echo "$0: SIGCHLD on sync ignored as expected" >&2
 252         else
 253                 echo "$0: error - sync firmware request cancelled due to SIGCHLD" >&2
 254                 exit 1
 255         fi
 256         set -e
 257 }
 258
 259 run_sysfs_custom_load_tests()
 260 {
 261         if load_fw_custom "$NAME" "$FW" ; then
 262                 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 263                         echo "$0: firmware was not loaded" >&2
 264                         exit 1
 265                 else
 266                         echo "$0: custom fallback loading mechanism works"
 267                 fi
 268         fi
 269
 270         if load_fw_custom "$NAME" "$FW" ; then
 271                 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 272                         echo "$0: firmware was not loaded" >&2
 273                         exit 1
 274                 else
 275                         echo "$0: custom fallback loading mechanism works"
 276                 fi
 277         fi
 278
 279         if load_fw_custom_cancel "nope-$NAME" "$FW" ; then
 280                 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 281                         echo "$0: firmware was expected to be cancelled" >&2
 282                         exit 1
 283                 else
 284                         echo "$0: cancelling custom fallback mechanism works"
 285                 fi
 286         fi
 287 }
 288
 289 run_sysfs_main_tests
 290 run_sysfs_custom_load_tests
 291
 292 exit 0