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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.
6set -e
7
8modprobe test_firmware
9
10DIR=/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.
15HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; else echo no; fi)
16
17if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
18       OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
19else
20	echo "usermode helper disabled so ignoring test"
21	exit 0
22fi
23
24FWPATH=$(mktemp -d)
25FW="$FWPATH/test-firmware.bin"
26
27test_finish()
28{
29	echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
30	rm -f "$FW"
31	rmdir "$FWPATH"
32}
33
34load_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
61trap "test_finish" EXIT
62
63# This is an unlikely real-world firmware content. :)
64echo "ABCD0123" >"$FW"
65NAME=$(basename "$FW")
66
67DEVPATH="$DIR"/"nope-$NAME"/loading
68
69# Test failure when doing nothing (timeout works).
70echo -n 2 >/sys/class/firmware/timeout
71echo -n "nope-$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.
75sleep 1
76if [ ! -f $DEVPATH ]; then
77	echo "$0: fallback mechanism immediately cancelled"
78	echo ""
79	echo "The file never appeared: $DEVPATH"
80	echo ""
81	echo "This might be a distribution udev rule setup by your distribution"
82	echo "to immediately cancel all fallback requests, this must be"
83	echo "removed before running these tests. To confirm look for"
84	echo "a firmware rule like /lib/udev/rules.d/50-firmware.rules"
85	echo "and see if you have something like this:"
86	echo ""
87	echo "SUBSYSTEM==\"firmware\", ACTION==\"add\", ATTR{loading}=\"-1\""
88	echo ""
89	echo "If you do remove this file or comment out this line before"
90	echo "proceeding with these tests."
91	exit 1
92fi
93
94if diff -q "$FW" /dev/test_firmware >/dev/null ; then
95	echo "$0: firmware was not expected to match" >&2
96	exit 1
97else
98	echo "$0: timeout works"
99fi
100
101# Put timeout high enough for us to do work but not so long that failures
102# slow down this test too much.
103echo 4 >/sys/class/firmware/timeout
104
105# Load this script instead of the desired firmware.
106load_fw "$NAME" "$0"
107if diff -q "$FW" /dev/test_firmware >/dev/null ; then
108	echo "$0: firmware was not expected to match" >&2
109	exit 1
110else
111	echo "$0: firmware comparison works"
112fi
113
114# Do a proper load, which should work correctly.
115load_fw "$NAME" "$FW"
116if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
117	echo "$0: firmware was not loaded" >&2
118	exit 1
119else
120	echo "$0: user helper firmware loading works"
121fi
122
123exit 0
124