tools/testing/selftests/firmware/fw_userhelper.sh

   1 #!/bin/sh
   2 # This validates that the kernel will fall back to using the user helper
   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 trap "test_finish" EXIT
  62
  63 # This is an unlikely real-world firmware content. :)
  64 echo "ABCD0123" >"$FW"
  65 NAME=$(basename "$FW")
  66
  67 DEVPATH="$DIR"/"nope-$NAME"/loading
  68
  69 # Test failure when doing nothing (timeout works).
  70 echo -n 2 >/sys/class/firmware/timeout
  71 echo -n "nope-$NAME" >"$DIR"/trigger_request 2>/dev/null &
  72
  73 # Give the kernel some time to load the loading file, must be less
  74 # than the timeout above.
  75 sleep 1
  76 if [ ! -f $DEVPATH ]; then
  77         echo "$0: fallback mechanism immediately cancelled"
  78         echo ""
  79         echo "The file never appeared: $DEVPATH"
  80         echo ""
  81         echo "This might be a distribution udev rule setup by your distribution"
  82         echo "to immediately cancel all fallback requests, this must be"
  83         echo "removed before running these tests. To confirm look for"
  84         echo "a firmware rule like /lib/udev/rules.d/50-firmware.rules"
  85         echo "and see if you have something like this:"
  86         echo ""
  87         echo "SUBSYSTEM==\"firmware\", ACTION==\"add\", ATTR{loading}=\"-1\""
  88         echo ""
  89         echo "If you do remove this file or comment out this line before"
  90         echo "proceeding with these tests."
  91         exit 1
  92 fi
  93
  94 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
  95         echo "$0: firmware was not expected to match" >&2
  96         exit 1
  97 else
  98         echo "$0: timeout works"
  99 fi
 100
 101 # Put timeout high enough for us to do work but not so long that failures
 102 # slow down this test too much.
 103 echo 4 >/sys/class/firmware/timeout
 104
 105 # Load this script instead of the desired firmware.
 106 load_fw "$NAME" "$0"
 107 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 108         echo "$0: firmware was not expected to match" >&2
 109         exit 1
 110 else
 111         echo "$0: firmware comparison works"
 112 fi
 113
 114 # Do a proper load, which should work correctly.
 115 load_fw "$NAME" "$FW"
 116 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
 117         echo "$0: firmware was not loaded" >&2
 118         exit 1
 119 else
 120         echo "$0: user helper firmware loading works"
 121 fi
 122
 123 exit 0