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         local name="$1"
  90         local file="$2"
  91
  92         echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
  93
  94         # Give kernel a chance to react.
  95         local timeout=10
  96         while [ ! -e "$DIR"/"$name"/loading ]; do
  97                 sleep 0.1
  98                 timeout=$(( $timeout - 1 ))
  99                 if [ "$timeout" -eq 0 ]; then
 100                         echo "$0: firmware interface never appeared" >&2
 101                         exit 1
 102                 fi
 103         done
 104
 105         echo 1 >"$DIR"/"$name"/loading
 106         cat "$file" >"$DIR"/"$name"/data
 107         echo 0 >"$DIR"/"$name"/loading
 108
 109         # Wait for request to finish.
 110         wait
 111 }
 112
 113
 114 load_fw_custom_cancel()
 115 {
 116         local name="$1"
 117         local file="$2"
 118
 119         echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
 120
 121         # Give kernel a chance to react.
 122         local timeout=10
 123         while [ ! -e "$DIR"/"$name"/loading ]; do
 124                 sleep 0.1
 125                 timeout=$(( $timeout - 1 ))
 126                 if [ "$timeout" -eq 0 ]; then
 127                         echo "$0: firmware interface never appeared" >&2
 128                         exit 1
 129                 fi
 130         done
 131
 132         echo -1 >"$DIR"/"$name"/loading
 133
 134         # Wait for request to finish.
 135         wait
 136 }
 137
 138 load_fw_fallback_with_child()
 139 {
 140         local name="$1"
 141         local file="$2"
 142
 143         # This is the value already set but we want to be explicit
 144         echo 4 >/sys/class/firmware/timeout
 145
 146         sleep 1 &
 147         SECONDS_BEFORE=$(date +%s)
 148         echo -n "$name" >"$DIR"/trigger_request 2>/dev/null
 149         SECONDS_AFTER=$(date +%s)
 150         SECONDS_DELTA=$(($SECONDS_AFTER - $SECONDS_BEFORE))
 151         if [ "$SECONDS_DELTA" -lt 4 ]; then
 152                 RET=1
 153         else
 154                 RET=0
 155         fi
 156         wait
 157         return $RET
 158 }
 159
 160 trap "test_finish" EXIT
 161
 162 # This is an unlikely real-world firmware content. :)
 163 echo "ABCD0123" >"$FW"
 164 NAME=$(basename "$FW")
 165
 166 DEVPATH="$DIR"/"nope-$NAME"/loading
 167
 168 # Test failure when doing nothing (timeout works).
 169 echo -n 2 >/sys/class/firmware/timeout
 170 echo -n "nope-$NAME" >"$DIR"/trigger_request 2>/dev/null &
 171
 172 # Give the kernel some time to load the loading file, must be less
 173 # than the timeout above.
 174 sleep 1
 175 if [ ! -f $DEVPATH ]; then
 176         echo "$0: fallback mechanism immediately cancelled"
 177         echo ""
 178         echo "The file never appeared: $DEVPATH"
 179         echo ""
 180         echo "This might be a distribution udev rule setup by your distribution"
 181         echo "to immediately cancel all fallback requests, this must be"
 182         echo "removed before running these tests. To confirm look for"
 183         echo "a firmware rule like /lib/udev/rules.d/50-firmware.rules"
 184         echo "and see if you have something like this:"
 185         echo ""
 186         echo "SUBSYSTEM==\"firmware\", ACTION==\"add\", ATTR{loading}=\"-1\""
 187         echo ""
 188         echo "If you do remove this file or comment out this line before"
 189         echo "proceeding with these tests."
 190         exit 1
 191 fi
 192
 193 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 194         echo "$0: firmware was not expected to match" >&2
 195         exit 1
 196 else
 197         echo "$0: timeout works"
 198 fi
 199
 200 # Put timeout high enough for us to do work but not so long that failures
 201 # slow down this test too much.
 202 echo 4 >/sys/class/firmware/timeout
 203
 204 # Load this script instead of the desired firmware.
 205 load_fw "$NAME" "$0"
 206 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 207         echo "$0: firmware was not expected to match" >&2
 208         exit 1
 209 else
 210         echo "$0: firmware comparison works"
 211 fi
 212
 213 # Do a proper load, which should work correctly.
 214 load_fw "$NAME" "$FW"
 215 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 216         echo "$0: firmware was not loaded" >&2
 217         exit 1
 218 else
 219         echo "$0: fallback mechanism works"
 220 fi
 221
 222 load_fw_cancel "nope-$NAME" "$FW"
 223 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 224         echo "$0: firmware was expected to be cancelled" >&2
 225         exit 1
 226 else
 227         echo "$0: cancelling fallback mechanism works"
 228 fi
 229
 230 load_fw_custom "$NAME" "$FW"
 231 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 232         echo "$0: firmware was not loaded" >&2
 233         exit 1
 234 else
 235         echo "$0: custom fallback loading mechanism works"
 236 fi
 237
 238 load_fw_custom_cancel "nope-$NAME" "$FW"
 239 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 240         echo "$0: firmware was expected to be cancelled" >&2
 241         exit 1
 242 else
 243         echo "$0: cancelling custom fallback mechanism works"
 244 fi
 245
 246 set +e
 247 load_fw_fallback_with_child "nope-signal-$NAME" "$FW"
 248 if [ "$?" -eq 0 ]; then
 249         echo "$0: SIGCHLD on sync ignored as expected" >&2
 250 else
 251         echo "$0: error - sync firmware request cancelled due to SIGCHLD" >&2
 252         exit 1
 253 fi
 254 set -e
 255
 256 exit 0