1 // SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1
2 /*
3 * proc sysctl test driver
4 *
5 * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
6 */
7
8 /*
9 * This module provides an interface to the proc sysctl interfaces. This
10 * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the
11 * system unless explicitly requested by name. You can also build this driver
12 * into your kernel.
13 */
14
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17 #include <linux/init.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/printk.h>
21 #include <linux/fs.h>
22 #include <linux/miscdevice.h>
23 #include <linux/slab.h>
24 #include <linux/uaccess.h>
25 #include <linux/async.h>
26 #include <linux/delay.h>
27 #include <linux/vmalloc.h>
28
29 static int i_zero;
30 static int i_one_hundred = 100;
31 static int match_int_ok = 1;
32
33 struct test_sysctl_data {
34 int int_0001;
35 int int_0002;
36 int int_0003[4];
37
38 int boot_int;
39
40 unsigned int uint_0001;
41
42 char string_0001[65];
43
44 #define SYSCTL_TEST_BITMAP_SIZE 65536
45 unsigned long *bitmap_0001;
46 };
47
48 static struct test_sysctl_data test_data = {
49 .int_0001 = 60,
50 .int_0002 = 1,
51
52 .int_0003[0] = 0,
53 .int_0003[1] = 1,
54 .int_0003[2] = 2,
55 .int_0003[3] = 3,
56
57 .boot_int = 0,
58
59 .uint_0001 = 314,
60
61 .string_0001 = "(none)",
62 };
63
64 /* These are all under /proc/sys/debug/test_sysctl/ */
65 static struct ctl_table test_table[] = {
66 {
67 .procname = "int_0001",
68 .data = &test_data.int_0001,
69 .maxlen = sizeof(int),
70 .mode = 0644,
71 .proc_handler = proc_dointvec_minmax,
72 .extra1 = &i_zero,
73 .extra2 = &i_one_hundred,
74 },
75 {
76 .procname = "int_0002",
77 .data = &test_data.int_0002,
78 .maxlen = sizeof(int),
79 .mode = 0644,
80 .proc_handler = proc_dointvec,
81 },
82 {
83 .procname = "int_0003",
84 .data = &test_data.int_0003,
85 .maxlen = sizeof(test_data.int_0003),
86 .mode = 0644,
87 .proc_handler = proc_dointvec,
88 },
89 {
90 .procname = "match_int",
91 .data = &match_int_ok,
92 .maxlen = sizeof(match_int_ok),
93 .mode = 0444,
94 .proc_handler = proc_dointvec,
95 },
96 {
97 .procname = "boot_int",
98 .data = &test_data.boot_int,
99 .maxlen = sizeof(test_data.boot_int),
100 .mode = 0644,
101 .proc_handler = proc_dointvec,
102 .extra1 = SYSCTL_ZERO,
103 .extra2 = SYSCTL_ONE,
104 },
105 {
106 .procname = "uint_0001",
107 .data = &test_data.uint_0001,
108 .maxlen = sizeof(unsigned int),
109 .mode = 0644,
110 .proc_handler = proc_douintvec,
111 },
112 {
113 .procname = "string_0001",
114 .data = &test_data.string_0001,
115 .maxlen = sizeof(test_data.string_0001),
116 .mode = 0644,
117 .proc_handler = proc_dostring,
118 },
119 {
120 .procname = "bitmap_0001",
121 .data = &test_data.bitmap_0001,
122 .maxlen = SYSCTL_TEST_BITMAP_SIZE,
123 .mode = 0644,
124 .proc_handler = proc_do_large_bitmap,
125 },
126 { }
127 };
128
129 static struct ctl_table_header *test_sysctl_header;
130
test_sysctl_init(void)131 static int __init test_sysctl_init(void)
132 {
133 int i;
134
135 struct {
136 int defined;
137 int wanted;
138 } match_int[] = {
139 {.defined = *(int *)SYSCTL_ZERO, .wanted = 0},
140 {.defined = *(int *)SYSCTL_ONE, .wanted = 1},
141 {.defined = *(int *)SYSCTL_TWO, .wanted = 2},
142 {.defined = *(int *)SYSCTL_THREE, .wanted = 3},
143 {.defined = *(int *)SYSCTL_FOUR, .wanted = 4},
144 {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100},
145 {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200},
146 {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000},
147 {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000},
148 {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX},
149 {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535},
150 {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1},
151 };
152
153 for (i = 0; i < ARRAY_SIZE(match_int); i++)
154 if (match_int[i].defined != match_int[i].wanted)
155 match_int_ok = 0;
156
157 test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
158 if (!test_data.bitmap_0001)
159 return -ENOMEM;
160 test_sysctl_header = register_sysctl("debug/test_sysctl", test_table);
161 if (!test_sysctl_header) {
162 kfree(test_data.bitmap_0001);
163 return -ENOMEM;
164 }
165 return 0;
166 }
167 module_init(test_sysctl_init);
168
test_sysctl_exit(void)169 static void __exit test_sysctl_exit(void)
170 {
171 kfree(test_data.bitmap_0001);
172 if (test_sysctl_header)
173 unregister_sysctl_table(test_sysctl_header);
174 }
175
176 module_exit(test_sysctl_exit);
177
178 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
179 MODULE_LICENSE("GPL");
180