/* * proc sysctl test driver * * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or at your option any * later version; or, when distributed separately from the Linux kernel or * when incorporated into other software packages, subject to the following * license: * * This program is free software; you can redistribute it and/or modify it * under the terms of copyleft-next (version 0.3.1 or later) as published * at http://copyleft-next.org/. */ /* * This module provides an interface to the the proc sysctl interfaces. This * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the * system unless explicitly requested by name. You can also build this driver * into your kernel. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h> #include <linux/list.h> #include <linux/module.h> #include <linux/printk.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/async.h> #include <linux/delay.h> #include <linux/vmalloc.h> static int i_zero; static int i_one_hundred = 100; struct test_sysctl_data { int int_0001; int int_0002; int int_0003[4]; unsigned int uint_0001; char string_0001[65]; }; static struct test_sysctl_data test_data = { .int_0001 = 60, .int_0002 = 1, .int_0003[0] = 0, .int_0003[1] = 1, .int_0003[2] = 2, .int_0003[3] = 3, .uint_0001 = 314, .string_0001 = "(none)", }; /* These are all under /proc/sys/debug/test_sysctl/ */ static struct ctl_table test_table[] = { { .procname = "int_0001", .data = &test_data.int_0001, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &i_zero, .extra2 = &i_one_hundred, }, { .procname = "int_0002", .data = &test_data.int_0002, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "int_0003", .data = &test_data.int_0003, .maxlen = sizeof(test_data.int_0003), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "uint_0001", .data = &test_data.uint_0001, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_douintvec, }, { .procname = "string_0001", .data = &test_data.string_0001, .maxlen = sizeof(test_data.string_0001), .mode = 0644, .proc_handler = proc_dostring, }, { } }; static struct ctl_table test_sysctl_table[] = { { .procname = "test_sysctl", .maxlen = 0, .mode = 0555, .child = test_table, }, { } }; static struct ctl_table test_sysctl_root_table[] = { { .procname = "debug", .maxlen = 0, .mode = 0555, .child = test_sysctl_table, }, { } }; static struct ctl_table_header *test_sysctl_header; static int __init test_sysctl_init(void) { test_sysctl_header = register_sysctl_table(test_sysctl_root_table); if (!test_sysctl_header) return -ENOMEM; return 0; } late_initcall(test_sysctl_init); static void __exit test_sysctl_exit(void) { if (test_sysctl_header) unregister_sysctl_table(test_sysctl_header); } module_exit(test_sysctl_exit); MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>"); MODULE_LICENSE("GPL");