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 }; 135 136 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 } 162 163 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 }; 189 190 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 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); 241 242 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