atheros/atl1c:fix repeated words in comments
[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_ZERO ((void *)&sysctl_vals[0])
42#define SYSCTL_ONE ((void *)&sysctl_vals[1])
43#define SYSCTL_TWO ((void *)&sysctl_vals[2])
44#define SYSCTL_THREE ((void *)&sysctl_vals[3])
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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])
4c7f24f8 54#define SYSCTL_NEG_ONE ((void *)&sysctl_vals[11])
54771613 55
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56extern const int sysctl_vals[];
57
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58#define SYSCTL_LONG_ZERO ((void *)&sysctl_long_vals[0])
59#define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1])
60#define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2])
61
62extern const unsigned long sysctl_long_vals[];
63
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64typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
65 size_t *lenp, loff_t *ppos);
66
67int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *);
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68int proc_dobool(struct ctl_table *table, int write, void *buffer,
69 size_t *lenp, loff_t *ppos);
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70int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *);
71int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
72int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
73int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
74 size_t *lenp, loff_t *ppos);
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75int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
76 size_t *lenp, loff_t *ppos);
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77int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
78int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
79 loff_t *);
80int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *,
81 loff_t *);
82int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
83int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *,
84 size_t *, loff_t *);
85int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *);
86int proc_do_static_key(struct ctl_table *table, int write, void *buffer,
87 size_t *lenp, loff_t *ppos);
1da177e4 88
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89/*
90 * Register a set of sysctl names by calling register_sysctl_table
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91 * with an initialised array of struct ctl_table's. An entry with
92 * NULL procname terminates the table. table->de will be
d99f160a 93 * set up by the registration and need not be initialised in advance.
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94 *
95 * sysctl names can be mirrored automatically under /proc/sys. The
96 * procname supplied controls /proc naming.
97 *
88db0aa2 98 * The table's mode will be honoured for proc-fs access.
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99 *
100 * Leaf nodes in the sysctl tree will be represented by a single file
101 * under /proc; non-leaf nodes will be represented by directories. A
102 * null procname disables /proc mirroring at this node.
d99f160a 103 *
88db0aa2 104 * The data and maxlen fields of the ctl_table
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105 * struct enable minimal validation of the values being written to be
106 * performed, and the mode field allows minimal authentication.
107 *
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108 * There must be a proc_handler routine for any terminal nodes
109 * mirrored under /proc/sys (non-terminals are handled by a built-in
110 * directory handler). Several default handlers are available to
111 * cover common cases.
112 */
113
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114/* Support for userspace poll() to watch for changes */
115struct ctl_table_poll {
116 atomic_t event;
117 wait_queue_head_t wait;
118};
119
120static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
121{
122 return (void *)(unsigned long)atomic_read(&poll->event);
123}
124
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125#define __CTL_TABLE_POLL_INITIALIZER(name) { \
126 .event = ATOMIC_INIT(0), \
127 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
128
129#define DEFINE_CTL_TABLE_POLL(name) \
130 struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
131
1da177e4 132/* A sysctl table is an array of struct ctl_table: */
d5ffb71b 133struct ctl_table {
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134 const char *procname; /* Text ID for /proc/sys, or zero */
135 void *data;
136 int maxlen;
36fcb589 137 umode_t mode;
f728019b 138 struct ctl_table *child; /* Deprecated */
1da177e4 139 proc_handler *proc_handler; /* Callback for text formatting */
f1ecf068 140 struct ctl_table_poll *poll;
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141 void *extra1;
142 void *extra2;
3859a271 143} __randomize_layout;
1da177e4 144
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145struct ctl_node {
146 struct rb_node node;
147 struct ctl_table_header *header;
148};
149
1da177e4 150/* struct ctl_table_header is used to maintain dynamic lists of
d8217f07 151 struct ctl_table trees. */
d5ffb71b 152struct ctl_table_header {
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153 union {
154 struct {
155 struct ctl_table *ctl_table;
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156 int used;
157 int count;
938aaa4f 158 int nreg;
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159 };
160 struct rcu_head rcu;
161 };
330d57fb 162 struct completion *unregistering;
23eb06de 163 struct ctl_table *ctl_table_arg;
e51b6ba0 164 struct ctl_table_root *root;
73455092 165 struct ctl_table_set *set;
7ec66d06 166 struct ctl_dir *parent;
ac13ac6f 167 struct ctl_node *node;
2fd1d2c4 168 struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */
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169};
170
171struct ctl_dir {
172 /* Header must be at the start of ctl_dir */
173 struct ctl_table_header header;
ac13ac6f 174 struct rb_root root;
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175};
176
0ce8974d 177struct ctl_table_set {
0ce8974d 178 int (*is_seen)(struct ctl_table_set *);
0e47c99d 179 struct ctl_dir dir;
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180};
181
182struct ctl_table_root {
0ce8974d 183 struct ctl_table_set default_set;
13bcc6a2 184 struct ctl_table_set *(*lookup)(struct ctl_table_root *root);
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185 void (*set_ownership)(struct ctl_table_header *head,
186 struct ctl_table *table,
187 kuid_t *uid, kgid_t *gid);
73f7ef43 188 int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
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189};
190
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191/* struct ctl_path describes where in the hierarchy a table is added */
192struct ctl_path {
193 const char *procname;
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194};
195
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196#ifdef CONFIG_SYSCTL
197
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198#define DECLARE_SYSCTL_BASE(_name, _table) \
199static struct ctl_table _name##_base_table[] = { \
200 { \
201 .procname = #_name, \
202 .mode = 0555, \
203 .child = _table, \
204 }, \
205 { }, \
206}
207
208extern int __register_sysctl_base(struct ctl_table *base_table);
209
210#define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table)
211
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212void proc_sys_poll_notify(struct ctl_table_poll *poll);
213
214extern void setup_sysctl_set(struct ctl_table_set *p,
9eb47c26 215 struct ctl_table_root *root,
0ce8974d 216 int (*is_seen)(struct ctl_table_set *));
97324cd8 217extern void retire_sysctl_set(struct ctl_table_set *set);
0ce8974d 218
6e9d5164 219struct ctl_table_header *__register_sysctl_table(
60a47a2e 220 struct ctl_table_set *set,
6e9d5164 221 const char *path, struct ctl_table *table);
e51b6ba0 222struct ctl_table_header *__register_sysctl_paths(
60a47a2e 223 struct ctl_table_set *set,
e51b6ba0 224 const struct ctl_path *path, struct ctl_table *table);
fea478d4 225struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
d8217f07 226struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
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227struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
228 struct ctl_table *table);
0b4d4147 229
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230void unregister_sysctl_table(struct ctl_table_header * table);
231
d8c0418a 232extern int sysctl_init_bases(void);
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233extern void __register_sysctl_init(const char *path, struct ctl_table *table,
234 const char *table_name);
235#define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table)
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236extern struct ctl_table_header *register_sysctl_mount_point(const char *path);
237
3db978d4 238void do_sysctl_args(void);
1998f193
LC
239int do_proc_douintvec(struct ctl_table *table, int write,
240 void *buffer, size_t *lenp, loff_t *ppos,
241 int (*conv)(unsigned long *lvalp,
242 unsigned int *valp,
243 int write, void *data),
244 void *data);
f9bd6733 245
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CH
246extern int pwrsw_enabled;
247extern int unaligned_enabled;
248extern int unaligned_dump_stack;
249extern int no_unaligned_warning;
250
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251extern struct ctl_table sysctl_mount_point[];
252
0ce8974d 253#else /* CONFIG_SYSCTL */
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254
255#define DECLARE_SYSCTL_BASE(_name, _table)
256
257static inline int __register_sysctl_base(struct ctl_table *base_table)
258{
259 return 0;
260}
261
262#define register_sysctl_base(table) __register_sysctl_base(table)
263
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264static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
265{
266 return NULL;
267}
268
6cb91741 269static inline struct ctl_table_header *register_sysctl_mount_point(const char *path)
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270{
271 return NULL;
272}
273
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274static inline struct ctl_table_header *register_sysctl_paths(
275 const struct ctl_path *path, struct ctl_table *table)
276{
277 return NULL;
278}
279
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280static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
281{
282 return NULL;
283}
284
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285static inline void unregister_sysctl_table(struct ctl_table_header * table)
286{
287}
288
289static inline void setup_sysctl_set(struct ctl_table_set *p,
9eb47c26 290 struct ctl_table_root *root,
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291 int (*is_seen)(struct ctl_table_set *))
292{
293}
294
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295static inline void do_sysctl_args(void)
296{
297}
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298#endif /* CONFIG_SYSCTL */
299
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300int sysctl_max_threads(struct ctl_table *table, int write, void *buffer,
301 size_t *lenp, loff_t *ppos);
16db3d3f 302
1da177e4 303#endif /* _LINUX_SYSCTL_H */