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 }; 136 137 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 } 163 164 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 }; 189 190 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 } 202 203 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[] = { }; 224 225 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 } 241 242 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); 264 265 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