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 struct test_sysctl_data { 34 int int_0001; 35 int int_0002; 36 int int_0003[4]; 37 38 int boot_int; 39 40 unsigned int uint_0001; 41 42 char string_0001[65]; 43 44 #define SYSCTL_TEST_BITMAP_SIZE 65536 45 unsigned long *bitmap_0001; 46 }; 47 48 static struct test_sysctl_data test_data = { 49 .int_0001 = 60, 50 .int_0002 = 1, 51 52 .int_0003[0] = 0, 53 .int_0003[1] = 1, 54 .int_0003[2] = 2, 55 .int_0003[3] = 3, 56 57 .boot_int = 0, 58 59 .uint_0001 = 314, 60 61 .string_0001 = "(none)", 62 }; 63 64 /* These are all under /proc/sys/debug/test_sysctl/ */ 65 static struct ctl_table test_table[] = { 66 { 67 .procname = "int_0001", 68 .data = &test_data.int_0001, 69 .maxlen = sizeof(int), 70 .mode = 0644, 71 .proc_handler = proc_dointvec_minmax, 72 .extra1 = &i_zero, 73 .extra2 = &i_one_hundred, 74 }, 75 { 76 .procname = "int_0002", 77 .data = &test_data.int_0002, 78 .maxlen = sizeof(int), 79 .mode = 0644, 80 .proc_handler = proc_dointvec, 81 }, 82 { 83 .procname = "int_0003", 84 .data = &test_data.int_0003, 85 .maxlen = sizeof(test_data.int_0003), 86 .mode = 0644, 87 .proc_handler = proc_dointvec, 88 }, 89 { 90 .procname = "match_int", 91 .data = &match_int_ok, 92 .maxlen = sizeof(match_int_ok), 93 .mode = 0444, 94 .proc_handler = proc_dointvec, 95 }, 96 { 97 .procname = "boot_int", 98 .data = &test_data.boot_int, 99 .maxlen = sizeof(test_data.boot_int), 100 .mode = 0644, 101 .proc_handler = proc_dointvec, 102 .extra1 = SYSCTL_ZERO, 103 .extra2 = SYSCTL_ONE, 104 }, 105 { 106 .procname = "uint_0001", 107 .data = &test_data.uint_0001, 108 .maxlen = sizeof(unsigned int), 109 .mode = 0644, 110 .proc_handler = proc_douintvec, 111 }, 112 { 113 .procname = "string_0001", 114 .data = &test_data.string_0001, 115 .maxlen = sizeof(test_data.string_0001), 116 .mode = 0644, 117 .proc_handler = proc_dostring, 118 }, 119 { 120 .procname = "bitmap_0001", 121 .data = &test_data.bitmap_0001, 122 .maxlen = SYSCTL_TEST_BITMAP_SIZE, 123 .mode = 0644, 124 .proc_handler = proc_do_large_bitmap, 125 }, 126 { } 127 }; 128 129 static struct ctl_table_header *test_sysctl_header; 130 131 static int __init test_sysctl_init(void) 132 { 133 int i; 134 135 struct { 136 int defined; 137 int wanted; 138 } match_int[] = { 139 {.defined = *(int *)SYSCTL_ZERO, .wanted = 0}, 140 {.defined = *(int *)SYSCTL_ONE, .wanted = 1}, 141 {.defined = *(int *)SYSCTL_TWO, .wanted = 2}, 142 {.defined = *(int *)SYSCTL_THREE, .wanted = 3}, 143 {.defined = *(int *)SYSCTL_FOUR, .wanted = 4}, 144 {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100}, 145 {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200}, 146 {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000}, 147 {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000}, 148 {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX}, 149 {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535}, 150 {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1}, 151 }; 152 153 for (i = 0; i < ARRAY_SIZE(match_int); i++) 154 if (match_int[i].defined != match_int[i].wanted) 155 match_int_ok = 0; 156 157 test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL); 158 if (!test_data.bitmap_0001) 159 return -ENOMEM; 160 test_sysctl_header = register_sysctl("debug/test_sysctl", test_table); 161 if (!test_sysctl_header) { 162 kfree(test_data.bitmap_0001); 163 return -ENOMEM; 164 } 165 return 0; 166 } 167 module_init(test_sysctl_init); 168 169 static void __exit test_sysctl_exit(void) 170 { 171 kfree(test_data.bitmap_0001); 172 if (test_sysctl_header) 173 unregister_sysctl_table(test_sysctl_header); 174 } 175 176 module_exit(test_sysctl_exit); 177 178 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>"); 179 MODULE_LICENSE("GPL"); 180