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 } sysctl_test_headers;
39
40 struct test_sysctl_data {
41 int int_0001;
42 int int_0002;
43 int int_0003[4];
44
45 int boot_int;
46
47 unsigned int uint_0001;
48
49 char string_0001[65];
50
51 #define SYSCTL_TEST_BITMAP_SIZE 65536
52 unsigned long *bitmap_0001;
53 };
54
55 static struct test_sysctl_data test_data = {
56 .int_0001 = 60,
57 .int_0002 = 1,
58
59 .int_0003[0] = 0,
60 .int_0003[1] = 1,
61 .int_0003[2] = 2,
62 .int_0003[3] = 3,
63
64 .boot_int = 0,
65
66 .uint_0001 = 314,
67
68 .string_0001 = "(none)",
69 };
70
71 /* These are all under /proc/sys/debug/test_sysctl/ */
72 static struct ctl_table test_table[] = {
73 {
74 .procname = "int_0001",
75 .data = &test_data.int_0001,
76 .maxlen = sizeof(int),
77 .mode = 0644,
78 .proc_handler = proc_dointvec_minmax,
79 .extra1 = &i_zero,
80 .extra2 = &i_one_hundred,
81 },
82 {
83 .procname = "int_0002",
84 .data = &test_data.int_0002,
85 .maxlen = sizeof(int),
86 .mode = 0644,
87 .proc_handler = proc_dointvec,
88 },
89 {
90 .procname = "int_0003",
91 .data = &test_data.int_0003,
92 .maxlen = sizeof(test_data.int_0003),
93 .mode = 0644,
94 .proc_handler = proc_dointvec,
95 },
96 {
97 .procname = "match_int",
98 .data = &match_int_ok,
99 .maxlen = sizeof(match_int_ok),
100 .mode = 0444,
101 .proc_handler = proc_dointvec,
102 },
103 {
104 .procname = "boot_int",
105 .data = &test_data.boot_int,
106 .maxlen = sizeof(test_data.boot_int),
107 .mode = 0644,
108 .proc_handler = proc_dointvec,
109 .extra1 = SYSCTL_ZERO,
110 .extra2 = SYSCTL_ONE,
111 },
112 {
113 .procname = "uint_0001",
114 .data = &test_data.uint_0001,
115 .maxlen = sizeof(unsigned int),
116 .mode = 0644,
117 .proc_handler = proc_douintvec,
118 },
119 {
120 .procname = "string_0001",
121 .data = &test_data.string_0001,
122 .maxlen = sizeof(test_data.string_0001),
123 .mode = 0644,
124 .proc_handler = proc_dostring,
125 },
126 {
127 .procname = "bitmap_0001",
128 .data = &test_data.bitmap_0001,
129 .maxlen = SYSCTL_TEST_BITMAP_SIZE,
130 .mode = 0644,
131 .proc_handler = proc_do_large_bitmap,
132 },
133 { }
134 };
135
test_sysctl_calc_match_int_ok(void)136 static void test_sysctl_calc_match_int_ok(void)
137 {
138 int i;
139
140 struct {
141 int defined;
142 int wanted;
143 } match_int[] = {
144 {.defined = *(int *)SYSCTL_ZERO, .wanted = 0},
145 {.defined = *(int *)SYSCTL_ONE, .wanted = 1},
146 {.defined = *(int *)SYSCTL_TWO, .wanted = 2},
147 {.defined = *(int *)SYSCTL_THREE, .wanted = 3},
148 {.defined = *(int *)SYSCTL_FOUR, .wanted = 4},
149 {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100},
150 {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200},
151 {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000},
152 {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000},
153 {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX},
154 {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535},
155 {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1},
156 };
157
158 for (i = 0; i < ARRAY_SIZE(match_int); i++)
159 if (match_int[i].defined != match_int[i].wanted)
160 match_int_ok = 0;
161 }
162
test_sysctl_setup_node_tests(void)163 static int test_sysctl_setup_node_tests(void)
164 {
165 test_sysctl_calc_match_int_ok();
166 test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
167 if (!test_data.bitmap_0001)
168 return -ENOMEM;
169 sysctl_test_headers.test_h_setup_node = register_sysctl("debug/test_sysctl", test_table);
170 if (!sysctl_test_headers.test_h_setup_node) {
171 kfree(test_data.bitmap_0001);
172 return -ENOMEM;
173 }
174
175 return 0;
176 }
177
178 /* Used to test that unregister actually removes the directory */
179 static struct ctl_table test_table_unregister[] = {
180 {
181 .procname = "unregister_error",
182 .data = &test_data.int_0001,
183 .maxlen = sizeof(int),
184 .mode = 0644,
185 .proc_handler = proc_dointvec_minmax,
186 },
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
test_sysctl_init(void)223 static int __init test_sysctl_init(void)
224 {
225 int err;
226
227 err = test_sysctl_setup_node_tests();
228 if (err)
229 goto out;
230
231 err = test_sysctl_run_unregister_nested();
232 if (err)
233 goto out;
234
235 err = test_sysctl_run_register_mount_point();
236
237 out:
238 return err;
239 }
240 module_init(test_sysctl_init);
241
test_sysctl_exit(void)242 static void __exit test_sysctl_exit(void)
243 {
244 kfree(test_data.bitmap_0001);
245 if (sysctl_test_headers.test_h_setup_node)
246 unregister_sysctl_table(sysctl_test_headers.test_h_setup_node);
247 if (sysctl_test_headers.test_h_mnt)
248 unregister_sysctl_table(sysctl_test_headers.test_h_mnt);
249 if (sysctl_test_headers.test_h_mnterror)
250 unregister_sysctl_table(sysctl_test_headers.test_h_mnterror);
251 }
252
253 module_exit(test_sysctl_exit);
254
255 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
256 MODULE_LICENSE("GPL");
257
