kernel/sysctl.c: rename sysctl_init() to sysctl_init_bases()
[linux-2.6-block.git] / include / linux / sysctl.h
CommitLineData
b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
1da177e4
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2/*
3 * sysctl.h: General linux system control interface
4 *
5 * Begun 24 March 1995, Stephen Tweedie
6 *
7 ****************************************************************
8 ****************************************************************
9 **
7cc13edc 10 ** WARNING:
1da177e4 11 ** The values in this file are exported to user space via
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12 ** the sysctl() binary interface. Do *NOT* change the
13 ** numbering of any existing values here, and do not change
14 ** any numbers within any one set of values. If you have to
93aec204 15 ** redefine an existing interface, use a new number for it.
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16 ** The kernel will then return -ENOTDIR to any application using
17 ** the old binary interface.
18 **
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19 ****************************************************************
20 ****************************************************************
21 */
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22#ifndef _LINUX_SYSCTL_H
23#define _LINUX_SYSCTL_H
24
d4ed803c 25#include <linux/list.h>
684adca4 26#include <linux/rcupdate.h>
f1ecf068 27#include <linux/wait.h>
ac13ac6f 28#include <linux/rbtree.h>
e79c6a4f 29#include <linux/uidgid.h>
607ca46e 30#include <uapi/linux/sysctl.h>
1da177e4 31
805b5d5e 32/* For the /proc/sys support */
db3f6001 33struct completion;
1ff007eb 34struct ctl_table;
e51b6ba0 35struct nsproxy;
d7321cd6 36struct ctl_table_root;
f7e6ced4 37struct ctl_table_header;
7ec66d06 38struct ctl_dir;
f7e6ced4 39
eec4844f 40/* Keep the same order as in fs/proc/proc_sysctl.c */
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41#define SYSCTL_NEG_ONE ((void *)&sysctl_vals[0])
42#define SYSCTL_ZERO ((void *)&sysctl_vals[1])
43#define SYSCTL_ONE ((void *)&sysctl_vals[2])
44#define SYSCTL_TWO ((void *)&sysctl_vals[3])
45#define SYSCTL_FOUR ((void *)&sysctl_vals[4])
46#define SYSCTL_ONE_HUNDRED ((void *)&sysctl_vals[5])
47#define SYSCTL_TWO_HUNDRED ((void *)&sysctl_vals[6])
48#define SYSCTL_ONE_THOUSAND ((void *)&sysctl_vals[7])
49#define SYSCTL_THREE_THOUSAND ((void *)&sysctl_vals[8])
50#define SYSCTL_INT_MAX ((void *)&sysctl_vals[9])
eec4844f 51
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52/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
53#define SYSCTL_MAXOLDUID ((void *)&sysctl_vals[10])
54
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55extern const int sysctl_vals[];
56
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57#define SYSCTL_LONG_ZERO ((void *)&sysctl_long_vals[0])
58#define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1])
59#define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2])
60
61extern const unsigned long sysctl_long_vals[];
62
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63typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
64 size_t *lenp, loff_t *ppos);
65
66int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *);
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67int proc_dobool(struct ctl_table *table, int write, void *buffer,
68 size_t *lenp, loff_t *ppos);
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69int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *);
70int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
71int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
72int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
73 size_t *lenp, loff_t *ppos);
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74int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
75 size_t *lenp, loff_t *ppos);
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76int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
77int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
78 loff_t *);
79int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *,
80 loff_t *);
81int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
82int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *,
83 size_t *, loff_t *);
84int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *);
85int proc_do_static_key(struct ctl_table *table, int write, void *buffer,
86 size_t *lenp, loff_t *ppos);
1da177e4 87
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88/*
89 * Register a set of sysctl names by calling register_sysctl_table
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90 * with an initialised array of struct ctl_table's. An entry with
91 * NULL procname terminates the table. table->de will be
d99f160a 92 * set up by the registration and need not be initialised in advance.
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93 *
94 * sysctl names can be mirrored automatically under /proc/sys. The
95 * procname supplied controls /proc naming.
96 *
88db0aa2 97 * The table's mode will be honoured for proc-fs access.
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98 *
99 * Leaf nodes in the sysctl tree will be represented by a single file
100 * under /proc; non-leaf nodes will be represented by directories. A
101 * null procname disables /proc mirroring at this node.
d99f160a 102 *
88db0aa2 103 * The data and maxlen fields of the ctl_table
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104 * struct enable minimal validation of the values being written to be
105 * performed, and the mode field allows minimal authentication.
106 *
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107 * There must be a proc_handler routine for any terminal nodes
108 * mirrored under /proc/sys (non-terminals are handled by a built-in
109 * directory handler). Several default handlers are available to
110 * cover common cases.
111 */
112
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113/* Support for userspace poll() to watch for changes */
114struct ctl_table_poll {
115 atomic_t event;
116 wait_queue_head_t wait;
117};
118
119static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
120{
121 return (void *)(unsigned long)atomic_read(&poll->event);
122}
123
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124#define __CTL_TABLE_POLL_INITIALIZER(name) { \
125 .event = ATOMIC_INIT(0), \
126 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
127
128#define DEFINE_CTL_TABLE_POLL(name) \
129 struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
130
1da177e4 131/* A sysctl table is an array of struct ctl_table: */
d5ffb71b 132struct ctl_table {
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133 const char *procname; /* Text ID for /proc/sys, or zero */
134 void *data;
135 int maxlen;
36fcb589 136 umode_t mode;
f728019b 137 struct ctl_table *child; /* Deprecated */
1da177e4 138 proc_handler *proc_handler; /* Callback for text formatting */
f1ecf068 139 struct ctl_table_poll *poll;
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140 void *extra1;
141 void *extra2;
3859a271 142} __randomize_layout;
1da177e4 143
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144struct ctl_node {
145 struct rb_node node;
146 struct ctl_table_header *header;
147};
148
1da177e4 149/* struct ctl_table_header is used to maintain dynamic lists of
d8217f07 150 struct ctl_table trees. */
d5ffb71b 151struct ctl_table_header {
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152 union {
153 struct {
154 struct ctl_table *ctl_table;
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155 int used;
156 int count;
938aaa4f 157 int nreg;
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158 };
159 struct rcu_head rcu;
160 };
330d57fb 161 struct completion *unregistering;
23eb06de 162 struct ctl_table *ctl_table_arg;
e51b6ba0 163 struct ctl_table_root *root;
73455092 164 struct ctl_table_set *set;
7ec66d06 165 struct ctl_dir *parent;
ac13ac6f 166 struct ctl_node *node;
2fd1d2c4 167 struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */
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168};
169
170struct ctl_dir {
171 /* Header must be at the start of ctl_dir */
172 struct ctl_table_header header;
ac13ac6f 173 struct rb_root root;
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174};
175
0ce8974d 176struct ctl_table_set {
0ce8974d 177 int (*is_seen)(struct ctl_table_set *);
0e47c99d 178 struct ctl_dir dir;
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179};
180
181struct ctl_table_root {
0ce8974d 182 struct ctl_table_set default_set;
13bcc6a2 183 struct ctl_table_set *(*lookup)(struct ctl_table_root *root);
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184 void (*set_ownership)(struct ctl_table_header *head,
185 struct ctl_table *table,
186 kuid_t *uid, kgid_t *gid);
73f7ef43 187 int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
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188};
189
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190/* struct ctl_path describes where in the hierarchy a table is added */
191struct ctl_path {
192 const char *procname;
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193};
194
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195#ifdef CONFIG_SYSCTL
196
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197#define DECLARE_SYSCTL_BASE(_name, _table) \
198static struct ctl_table _name##_base_table[] = { \
199 { \
200 .procname = #_name, \
201 .mode = 0555, \
202 .child = _table, \
203 }, \
204 { }, \
205}
206
207extern int __register_sysctl_base(struct ctl_table *base_table);
208
209#define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table)
210
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211void proc_sys_poll_notify(struct ctl_table_poll *poll);
212
213extern void setup_sysctl_set(struct ctl_table_set *p,
9eb47c26 214 struct ctl_table_root *root,
0ce8974d 215 int (*is_seen)(struct ctl_table_set *));
97324cd8 216extern void retire_sysctl_set(struct ctl_table_set *set);
0ce8974d 217
6e9d5164 218struct ctl_table_header *__register_sysctl_table(
60a47a2e 219 struct ctl_table_set *set,
6e9d5164 220 const char *path, struct ctl_table *table);
e51b6ba0 221struct ctl_table_header *__register_sysctl_paths(
60a47a2e 222 struct ctl_table_set *set,
e51b6ba0 223 const struct ctl_path *path, struct ctl_table *table);
fea478d4 224struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
d8217f07 225struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
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226struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
227 struct ctl_table *table);
0b4d4147 228
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229void unregister_sysctl_table(struct ctl_table_header * table);
230
d8c0418a 231extern int sysctl_init_bases(void);
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232extern void __register_sysctl_init(const char *path, struct ctl_table *table,
233 const char *table_name);
234#define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table)
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235extern struct ctl_table_header *register_sysctl_mount_point(const char *path);
236
3db978d4 237void do_sysctl_args(void);
1998f193
LC
238int do_proc_douintvec(struct ctl_table *table, int write,
239 void *buffer, size_t *lenp, loff_t *ppos,
240 int (*conv)(unsigned long *lvalp,
241 unsigned int *valp,
242 int write, void *data),
243 void *data);
f9bd6733 244
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CH
245extern int pwrsw_enabled;
246extern int unaligned_enabled;
247extern int unaligned_dump_stack;
248extern int no_unaligned_warning;
249
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250extern struct ctl_table sysctl_mount_point[];
251
0ce8974d 252#else /* CONFIG_SYSCTL */
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253
254#define DECLARE_SYSCTL_BASE(_name, _table)
255
256static inline int __register_sysctl_base(struct ctl_table *base_table)
257{
258 return 0;
259}
260
261#define register_sysctl_base(table) __register_sysctl_base(table)
262
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263static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
264{
265 return NULL;
266}
267
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268static inline struct sysctl_header *register_sysctl_mount_point(const char *path)
269{
270 return NULL;
271}
272
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273static inline struct ctl_table_header *register_sysctl_paths(
274 const struct ctl_path *path, struct ctl_table *table)
275{
276 return NULL;
277}
278
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279static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
280{
281 return NULL;
282}
283
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284static inline void unregister_sysctl_table(struct ctl_table_header * table)
285{
286}
287
288static inline void setup_sysctl_set(struct ctl_table_set *p,
9eb47c26 289 struct ctl_table_root *root,
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290 int (*is_seen)(struct ctl_table_set *))
291{
292}
293
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294static inline void do_sysctl_args(void)
295{
296}
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297#endif /* CONFIG_SYSCTL */
298
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299int sysctl_max_threads(struct ctl_table *table, int write, void *buffer,
300 size_t *lenp, loff_t *ppos);
16db3d3f 301
1da177e4 302#endif /* _LINUX_SYSCTL_H */