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
34 static struct {
35 struct ctl_table_header *test_h_setup_node;
36 struct ctl_table_header *test_h_mnt;
37 struct ctl_table_header *test_h_mnterror;
38 struct ctl_table_header *empty_add;
39 struct ctl_table_header *empty;
40 } sysctl_test_headers;
41
42 struct test_sysctl_data {
43 int int_0001;
44 int int_0002;
45 int int_0003[4];
46
47 int boot_int;
48
49 unsigned int uint_0001;
50
51 char string_0001[65];
52
53 #define SYSCTL_TEST_BITMAP_SIZE 65536
54 unsigned long *bitmap_0001;
55 };
56
57 static struct test_sysctl_data test_data = {
58 .int_0001 = 60,
59 .int_0002 = 1,
60
61 .int_0003[0] = 0,
62 .int_0003[1] = 1,
63 .int_0003[2] = 2,
64 .int_0003[3] = 3,
65
66 .boot_int = 0,
67
68 .uint_0001 = 314,
69
70 .string_0001 = "(none)",
71 };
72
73 /* These are all under /proc/sys/debug/test_sysctl/ */
74 static struct ctl_table test_table[] = {
75 {
76 .procname = "int_0001",
77 .data = &test_data.int_0001,
78 .maxlen = sizeof(int),
79 .mode = 0644,
80 .proc_handler = proc_dointvec_minmax,
81 .extra1 = &i_zero,
82 .extra2 = &i_one_hundred,
83 },
84 {
85 .procname = "int_0002",
86 .data = &test_data.int_0002,
87 .maxlen = sizeof(int),
88 .mode = 0644,
89 .proc_handler = proc_dointvec,
90 },
91 {
92 .procname = "int_0003",
93 .data = &test_data.int_0003,
94 .maxlen = sizeof(test_data.int_0003),
95 .mode = 0644,
96 .proc_handler = proc_dointvec,
97 },
98 {
99 .procname = "match_int",
100 .data = &match_int_ok,
101 .maxlen = sizeof(match_int_ok),
102 .mode = 0444,
103 .proc_handler = proc_dointvec,
104 },
105 {
106 .procname = "boot_int",
107 .data = &test_data.boot_int,
108 .maxlen = sizeof(test_data.boot_int),
109 .mode = 0644,
110 .proc_handler = proc_dointvec,
111 .extra1 = SYSCTL_ZERO,
112 .extra2 = SYSCTL_ONE,
113 },
114 {
115 .procname = "uint_0001",
116 .data = &test_data.uint_0001,
117 .maxlen = sizeof(unsigned int),
118 .mode = 0644,
119 .proc_handler = proc_douintvec,
120 },
121 {
122 .procname = "string_0001",
123 .data = &test_data.string_0001,
124 .maxlen = sizeof(test_data.string_0001),
125 .mode = 0644,
126 .proc_handler = proc_dostring,
127 },
128 {
129 .procname = "bitmap_0001",
130 .data = &test_data.bitmap_0001,
131 .maxlen = SYSCTL_TEST_BITMAP_SIZE,
132 .mode = 0644,
133 .proc_handler = proc_do_large_bitmap,
134 },
135 };
136
test_sysctl_calc_match_int_ok(void)137 static void test_sysctl_calc_match_int_ok(void)
138 {
139 int i;
140
141 struct {
142 int defined;
143 int wanted;
144 } match_int[] = {
145 {.defined = *(int *)SYSCTL_ZERO, .wanted = 0},
146 {.defined = *(int *)SYSCTL_ONE, .wanted = 1},
147 {.defined = *(int *)SYSCTL_TWO, .wanted = 2},
148 {.defined = *(int *)SYSCTL_THREE, .wanted = 3},
149 {.defined = *(int *)SYSCTL_FOUR, .wanted = 4},
150 {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100},
151 {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200},
152 {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000},
153 {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000},
154 {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX},
155 {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535},
156 {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1},
157 };
158
159 for (i = 0; i < ARRAY_SIZE(match_int); i++)
160 if (match_int[i].defined != match_int[i].wanted)
161 match_int_ok = 0;
162 }
163
test_sysctl_setup_node_tests(void)164 static int test_sysctl_setup_node_tests(void)
165 {
166 test_sysctl_calc_match_int_ok();
167 test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
168 if (!test_data.bitmap_0001)
169 return -ENOMEM;
170 sysctl_test_headers.test_h_setup_node = register_sysctl("debug/test_sysctl", test_table);
171 if (!sysctl_test_headers.test_h_setup_node) {
172 kfree(test_data.bitmap_0001);
173 return -ENOMEM;
174 }
175
176 return 0;
177 }
178
179 /* Used to test that unregister actually removes the directory */
180 static struct ctl_table test_table_unregister[] = {
181 {
182 .procname = "unregister_error",
183 .data = &test_data.int_0001,
184 .maxlen = sizeof(int),
185 .mode = 0644,
186 .proc_handler = proc_dointvec_minmax,
187 },
188 };
189
test_sysctl_run_unregister_nested(void)190 static int test_sysctl_run_unregister_nested(void)
191 {
192 struct ctl_table_header *unregister;
193
194 unregister = register_sysctl("debug/test_sysctl/unregister_error",
195 test_table_unregister);
196 if (!unregister)
197 return -ENOMEM;
198
199 unregister_sysctl_table(unregister);
200 return 0;
201 }
202
test_sysctl_run_register_mount_point(void)203 static int test_sysctl_run_register_mount_point(void)
204 {
205 sysctl_test_headers.test_h_mnt
206 = register_sysctl_mount_point("debug/test_sysctl/mnt");
207 if (!sysctl_test_headers.test_h_mnt)
208 return -ENOMEM;
209
210 sysctl_test_headers.test_h_mnterror
211 = register_sysctl("debug/test_sysctl/mnt/mnt_error",
212 test_table_unregister);
213 /*
214 * Don't check the result.:
215 * If it fails (expected behavior), return 0.
216 * If successful (missbehavior of register mount point), we want to see
217 * mnt_error when we run the sysctl test script
218 */
219
220 return 0;
221 }
222
223 static struct ctl_table test_table_empty[] = { };
224
test_sysctl_run_register_empty(void)225 static int test_sysctl_run_register_empty(void)
226 {
227 /* Tets that an empty dir can be created */
228 sysctl_test_headers.empty_add
229 = register_sysctl("debug/test_sysctl/empty_add", test_table_empty);
230 if (!sysctl_test_headers.empty_add)
231 return -ENOMEM;
232
233 /* Test that register on top of an empty dir works */
234 sysctl_test_headers.empty
235 = register_sysctl("debug/test_sysctl/empty_add/empty", test_table_empty);
236 if (!sysctl_test_headers.empty)
237 return -ENOMEM;
238
239 return 0;
240 }
241
test_sysctl_init(void)242 static int __init test_sysctl_init(void)
243 {
244 int err;
245
246 err = test_sysctl_setup_node_tests();
247 if (err)
248 goto out;
249
250 err = test_sysctl_run_unregister_nested();
251 if (err)
252 goto out;
253
254 err = test_sysctl_run_register_mount_point();
255 if (err)
256 goto out;
257
258 err = test_sysctl_run_register_empty();
259
260 out:
261 return err;
262 }
263 module_init(test_sysctl_init);
264
test_sysctl_exit(void)265 static void __exit test_sysctl_exit(void)
266 {
267 kfree(test_data.bitmap_0001);
268 if (sysctl_test_headers.test_h_setup_node)
269 unregister_sysctl_table(sysctl_test_headers.test_h_setup_node);
270 if (sysctl_test_headers.test_h_mnt)
271 unregister_sysctl_table(sysctl_test_headers.test_h_mnt);
272 if (sysctl_test_headers.test_h_mnterror)
273 unregister_sysctl_table(sysctl_test_headers.test_h_mnterror);
274 if (sysctl_test_headers.empty)
275 unregister_sysctl_table(sysctl_test_headers.empty);
276 if (sysctl_test_headers.empty_add)
277 unregister_sysctl_table(sysctl_test_headers.empty_add);
278 }
279
280 module_exit(test_sysctl_exit);
281
282 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
283 MODULE_LICENSE("GPL");
284