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 <[email protected]> 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 }; 137 138 static void test_sysctl_calc_match_int_ok(void) 139 { 140 int i; 141 142 struct { 143 int defined; 144 int wanted; 145 } match_int[] = { 146 {.defined = *(int *)SYSCTL_ZERO, .wanted = 0}, 147 {.defined = *(int *)SYSCTL_ONE, .wanted = 1}, 148 {.defined = *(int *)SYSCTL_TWO, .wanted = 2}, 149 {.defined = *(int *)SYSCTL_THREE, .wanted = 3}, 150 {.defined = *(int *)SYSCTL_FOUR, .wanted = 4}, 151 {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100}, 152 {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200}, 153 {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000}, 154 {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000}, 155 {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX}, 156 {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535}, 157 {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1}, 158 }; 159 160 for (i = 0; i < ARRAY_SIZE(match_int); i++) 161 if (match_int[i].defined != match_int[i].wanted) 162 match_int_ok = 0; 163 } 164 165 static int test_sysctl_setup_node_tests(void) 166 { 167 test_sysctl_calc_match_int_ok(); 168 test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL); 169 if (!test_data.bitmap_0001) 170 return -ENOMEM; 171 sysctl_test_headers.test_h_setup_node = register_sysctl("debug/test_sysctl", test_table); 172 if (!sysctl_test_headers.test_h_setup_node) { 173 kfree(test_data.bitmap_0001); 174 return -ENOMEM; 175 } 176 177 return 0; 178 } 179 180 /* Used to test that unregister actually removes the directory */ 181 static struct ctl_table test_table_unregister[] = { 182 { 183 .procname = "unregister_error", 184 .data = &test_data.int_0001, 185 .maxlen = sizeof(int), 186 .mode = 0644, 187 .proc_handler = proc_dointvec_minmax, 188 }, 189 {} 190 }; 191 192 static int test_sysctl_run_unregister_nested(void) 193 { 194 struct ctl_table_header *unregister; 195 196 unregister = register_sysctl("debug/test_sysctl/unregister_error", 197 test_table_unregister); 198 if (!unregister) 199 return -ENOMEM; 200 201 unregister_sysctl_table(unregister); 202 return 0; 203 } 204 205 static int test_sysctl_run_register_mount_point(void) 206 { 207 sysctl_test_headers.test_h_mnt 208 = register_sysctl_mount_point("debug/test_sysctl/mnt"); 209 if (!sysctl_test_headers.test_h_mnt) 210 return -ENOMEM; 211 212 sysctl_test_headers.test_h_mnterror 213 = register_sysctl("debug/test_sysctl/mnt/mnt_error", 214 test_table_unregister); 215 /* 216 * Don't check the result.: 217 * If it fails (expected behavior), return 0. 218 * If successful (missbehavior of register mount point), we want to see 219 * mnt_error when we run the sysctl test script 220 */ 221 222 return 0; 223 } 224 225 static struct ctl_table test_table_empty[] = { }; 226 227 static int test_sysctl_run_register_empty(void) 228 { 229 /* Tets that an empty dir can be created */ 230 sysctl_test_headers.empty_add 231 = register_sysctl("debug/test_sysctl/empty_add", test_table_empty); 232 if (!sysctl_test_headers.empty_add) 233 return -ENOMEM; 234 235 /* Test that register on top of an empty dir works */ 236 sysctl_test_headers.empty 237 = register_sysctl("debug/test_sysctl/empty_add/empty", test_table_empty); 238 if (!sysctl_test_headers.empty) 239 return -ENOMEM; 240 241 return 0; 242 } 243 244 static int __init test_sysctl_init(void) 245 { 246 int err; 247 248 err = test_sysctl_setup_node_tests(); 249 if (err) 250 goto out; 251 252 err = test_sysctl_run_unregister_nested(); 253 if (err) 254 goto out; 255 256 err = test_sysctl_run_register_mount_point(); 257 if (err) 258 goto out; 259 260 err = test_sysctl_run_register_empty(); 261 262 out: 263 return err; 264 } 265 module_init(test_sysctl_init); 266 267 static void __exit test_sysctl_exit(void) 268 { 269 kfree(test_data.bitmap_0001); 270 if (sysctl_test_headers.test_h_setup_node) 271 unregister_sysctl_table(sysctl_test_headers.test_h_setup_node); 272 if (sysctl_test_headers.test_h_mnt) 273 unregister_sysctl_table(sysctl_test_headers.test_h_mnt); 274 if (sysctl_test_headers.test_h_mnterror) 275 unregister_sysctl_table(sysctl_test_headers.test_h_mnterror); 276 if (sysctl_test_headers.empty) 277 unregister_sysctl_table(sysctl_test_headers.empty); 278 if (sysctl_test_headers.empty_add) 279 unregister_sysctl_table(sysctl_test_headers.empty_add); 280 } 281 282 module_exit(test_sysctl_exit); 283 284 MODULE_AUTHOR("Luis R. Rodriguez <[email protected]>"); 285 MODULE_LICENSE("GPL"); 286