tools/testing/selftests/firmware/fw_fallback.sh

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