1 #!/bin/sh
2 # SPDX-License-Identifier: GPL-2.0
3 #
4 # Test for mishandling of splice() on pseudofilesystems, which should catch
5 # bugs like 11990a5bd7e5 ("module: Correctly truncate sysfs sections output")
6 #
7 # Since splice fallback was removed as part of the set_fs() rework, many of these
8 # tests expect to fail now. See https://lore.kernel.org/lkml/202009181443.C2179FB@keescook/
9 set -e
10
11 DIR=$(dirname "$0")
12
13 ret=0
14
15 expect_success()
16 {
17 title="$1"
18 shift
19
20 echo "" >&2
21 echo "$title ..." >&2
22
23 set +e
24 "$@"
25 rc=$?
26 set -e
27
28 case "$rc" in
29 0)
30 echo "ok: $title succeeded" >&2
31 ;;
32 1)
33 echo "FAIL: $title should work" >&2
34 ret=$(( ret + 1 ))
35 ;;
36 *)
37 echo "FAIL: something else went wrong" >&2
38 ret=$(( ret + 1 ))
39 ;;
40 esac
41 }
42
43 expect_failure()
44 {
45 title="$1"
46 shift
47
48 echo "" >&2
49 echo "$title ..." >&2
50
51 set +e
52 "$@"
53 rc=$?
54 set -e
55
56 case "$rc" in
57 0)
58 echo "FAIL: $title unexpectedly worked" >&2
59 ret=$(( ret + 1 ))
60 ;;
61 1)
62 echo "ok: $title correctly failed" >&2
63 ;;
64 *)
65 echo "FAIL: something else went wrong" >&2
66 ret=$(( ret + 1 ))
67 ;;
68 esac
69 }
70
71 do_splice()
72 {
73 filename="$1"
74 bytes="$2"
75 expected="$3"
76 report="$4"
77
78 out=$("$DIR"/splice_read "$filename" "$bytes" | cat)
79 if [ "$out" = "$expected" ] ; then
80 echo " matched $report" >&2
81 return 0
82 else
83 echo " no match: '$out' vs $report" >&2
84 return 1
85 fi
86 }
87
88 test_splice()
89 {
90 filename="$1"
91
92 echo " checking $filename ..." >&2
93
94 full=$(cat "$filename")
95 rc=$?
96 if [ $rc -ne 0 ] ; then
97 return 2
98 fi
99
100 two=$(echo "$full" | grep -m1 . | cut -c-2)
101
102 # Make sure full splice has the same contents as a standard read.
103 echo " splicing 4096 bytes ..." >&2
104 if ! do_splice "$filename" 4096 "$full" "full read" ; then
105 return 1
106 fi
107
108 # Make sure a partial splice see the first two characters.
109 echo " splicing 2 bytes ..." >&2
110 if ! do_splice "$filename" 2 "$two" "'$two'" ; then
111 return 1
112 fi
113
114 return 0
115 }
116
117 ### /proc/$pid/ has no splice interface; these should all fail.
118 expect_failure "proc_single_open(), seq_read() splice" test_splice /proc/$$/limits
119 expect_failure "special open(), seq_read() splice" test_splice /proc/$$/comm
120
121 ### /proc/sys/ has a splice interface; these should all succeed.
122 expect_success "proc_handler: proc_dointvec_minmax() splice" test_splice /proc/sys/fs/nr_open
123 expect_success "proc_handler: proc_dostring() splice" test_splice /proc/sys/kernel/modprobe
124 expect_success "proc_handler: special read splice" test_splice /proc/sys/kernel/version
125
126 ### /sys/ has no splice interface; these should all fail.
127 if ! [ -d /sys/module/test_module/sections ] ; then
128 expect_success "test_module kernel module load" modprobe test_module
129 fi
130 expect_success "kernfs attr splice" test_splice /sys/module/test_module/coresize
131 expect_success "kernfs binattr splice" test_splice /sys/module/test_module/sections/.init.text
132
133 exit $ret
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