Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
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 |
7cc13edc EB |
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. |
7cc13edc EB |
16 | ** The kernel will then return -ENOTDIR to any application using |
17 | ** the old binary interface. | |
18 | ** | |
1da177e4 LT |
19 | **************************************************************** |
20 | **************************************************************** | |
21 | */ | |
1da177e4 LT |
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 | 33 | struct completion; |
1ff007eb | 34 | struct ctl_table; |
e51b6ba0 | 35 | struct nsproxy; |
d7321cd6 | 36 | struct ctl_table_root; |
f7e6ced4 | 37 | struct ctl_table_header; |
7ec66d06 | 38 | struct ctl_dir; |
f7e6ced4 | 39 | |
eec4844f | 40 | /* Keep the same order as in fs/proc/proc_sysctl.c */ |
78e36f3b XN |
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 MC |
51 | |
52 | extern const int sysctl_vals[]; | |
53 | ||
32927393 CH |
54 | typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer, |
55 | size_t *lenp, loff_t *ppos); | |
56 | ||
57 | int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *); | |
a2071573 JH |
58 | int proc_dobool(struct ctl_table *table, int write, void *buffer, |
59 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
60 | int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *); |
61 | int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *); | |
62 | int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
63 | int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer, | |
64 | size_t *lenp, loff_t *ppos); | |
cb944413 ED |
65 | int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer, |
66 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
67 | int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *); |
68 | int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *, | |
69 | loff_t *); | |
70 | int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *, | |
71 | loff_t *); | |
72 | int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
73 | int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *, | |
74 | size_t *, loff_t *); | |
75 | int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *); | |
76 | int proc_do_static_key(struct ctl_table *table, int write, void *buffer, | |
77 | size_t *lenp, loff_t *ppos); | |
1da177e4 | 78 | |
1da177e4 LT |
79 | /* |
80 | * Register a set of sysctl names by calling register_sysctl_table | |
2315ffa0 EB |
81 | * with an initialised array of struct ctl_table's. An entry with |
82 | * NULL procname terminates the table. table->de will be | |
d99f160a | 83 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
84 | * |
85 | * sysctl names can be mirrored automatically under /proc/sys. The | |
86 | * procname supplied controls /proc naming. | |
87 | * | |
88db0aa2 | 88 | * The table's mode will be honoured for proc-fs access. |
1da177e4 LT |
89 | * |
90 | * Leaf nodes in the sysctl tree will be represented by a single file | |
91 | * under /proc; non-leaf nodes will be represented by directories. A | |
92 | * null procname disables /proc mirroring at this node. | |
d99f160a | 93 | * |
88db0aa2 | 94 | * The data and maxlen fields of the ctl_table |
1da177e4 LT |
95 | * struct enable minimal validation of the values being written to be |
96 | * performed, and the mode field allows minimal authentication. | |
97 | * | |
1da177e4 LT |
98 | * There must be a proc_handler routine for any terminal nodes |
99 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
100 | * directory handler). Several default handlers are available to | |
101 | * cover common cases. | |
102 | */ | |
103 | ||
f1ecf068 LDM |
104 | /* Support for userspace poll() to watch for changes */ |
105 | struct ctl_table_poll { | |
106 | atomic_t event; | |
107 | wait_queue_head_t wait; | |
108 | }; | |
109 | ||
110 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
111 | { | |
112 | return (void *)(unsigned long)atomic_read(&poll->event); | |
113 | } | |
114 | ||
f1ecf068 LDM |
115 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
116 | .event = ATOMIC_INIT(0), \ | |
117 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
118 | ||
119 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
120 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
121 | ||
1da177e4 | 122 | /* A sysctl table is an array of struct ctl_table: */ |
d5ffb71b | 123 | struct ctl_table { |
1da177e4 LT |
124 | const char *procname; /* Text ID for /proc/sys, or zero */ |
125 | void *data; | |
126 | int maxlen; | |
36fcb589 | 127 | umode_t mode; |
f728019b | 128 | struct ctl_table *child; /* Deprecated */ |
1da177e4 | 129 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 130 | struct ctl_table_poll *poll; |
1da177e4 LT |
131 | void *extra1; |
132 | void *extra2; | |
3859a271 | 133 | } __randomize_layout; |
1da177e4 | 134 | |
ac13ac6f EB |
135 | struct ctl_node { |
136 | struct rb_node node; | |
137 | struct ctl_table_header *header; | |
138 | }; | |
139 | ||
1da177e4 | 140 | /* struct ctl_table_header is used to maintain dynamic lists of |
d8217f07 | 141 | struct ctl_table trees. */ |
d5ffb71b | 142 | struct ctl_table_header { |
dfef6dcd AV |
143 | union { |
144 | struct { | |
145 | struct ctl_table *ctl_table; | |
dfef6dcd AV |
146 | int used; |
147 | int count; | |
938aaa4f | 148 | int nreg; |
dfef6dcd AV |
149 | }; |
150 | struct rcu_head rcu; | |
151 | }; | |
330d57fb | 152 | struct completion *unregistering; |
23eb06de | 153 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 154 | struct ctl_table_root *root; |
73455092 | 155 | struct ctl_table_set *set; |
7ec66d06 | 156 | struct ctl_dir *parent; |
ac13ac6f | 157 | struct ctl_node *node; |
2fd1d2c4 | 158 | struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ |
7ec66d06 EB |
159 | }; |
160 | ||
161 | struct ctl_dir { | |
162 | /* Header must be at the start of ctl_dir */ | |
163 | struct ctl_table_header header; | |
ac13ac6f | 164 | struct rb_root root; |
1da177e4 LT |
165 | }; |
166 | ||
0ce8974d | 167 | struct ctl_table_set { |
0ce8974d | 168 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 169 | struct ctl_dir dir; |
0ce8974d EB |
170 | }; |
171 | ||
172 | struct ctl_table_root { | |
0ce8974d | 173 | struct ctl_table_set default_set; |
13bcc6a2 | 174 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
e79c6a4f DT |
175 | void (*set_ownership)(struct ctl_table_header *head, |
176 | struct ctl_table *table, | |
177 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 178 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
179 | }; |
180 | ||
29e796fd EB |
181 | /* struct ctl_path describes where in the hierarchy a table is added */ |
182 | struct ctl_path { | |
183 | const char *procname; | |
29e796fd EB |
184 | }; |
185 | ||
0ce8974d EB |
186 | #ifdef CONFIG_SYSCTL |
187 | ||
188 | void proc_sys_poll_notify(struct ctl_table_poll *poll); | |
189 | ||
190 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 191 | struct ctl_table_root *root, |
0ce8974d | 192 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 193 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 194 | |
6e9d5164 | 195 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 196 | struct ctl_table_set *set, |
6e9d5164 | 197 | const char *path, struct ctl_table *table); |
e51b6ba0 | 198 | struct ctl_table_header *__register_sysctl_paths( |
60a47a2e | 199 | struct ctl_table_set *set, |
e51b6ba0 | 200 | const struct ctl_path *path, struct ctl_table *table); |
fea478d4 | 201 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); |
d8217f07 | 202 | struct ctl_table_header *register_sysctl_table(struct ctl_table * table); |
29e796fd EB |
203 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
204 | struct ctl_table *table); | |
0b4d4147 | 205 | |
1da177e4 LT |
206 | void unregister_sysctl_table(struct ctl_table_header * table); |
207 | ||
de4e83bd | 208 | extern int sysctl_init(void); |
3ddd9a80 XN |
209 | extern void __register_sysctl_init(const char *path, struct ctl_table *table, |
210 | const char *table_name); | |
211 | #define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) | |
3db978d4 | 212 | void do_sysctl_args(void); |
f9bd6733 | 213 | |
2374c09b CH |
214 | extern int pwrsw_enabled; |
215 | extern int unaligned_enabled; | |
216 | extern int unaligned_dump_stack; | |
217 | extern int no_unaligned_warning; | |
218 | ||
f9bd6733 EB |
219 | extern struct ctl_table sysctl_mount_point[]; |
220 | ||
0ce8974d EB |
221 | #else /* CONFIG_SYSCTL */ |
222 | static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) | |
223 | { | |
224 | return NULL; | |
225 | } | |
226 | ||
227 | static inline struct ctl_table_header *register_sysctl_paths( | |
228 | const struct ctl_path *path, struct ctl_table *table) | |
229 | { | |
230 | return NULL; | |
231 | } | |
232 | ||
e609a6b8 AB |
233 | static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) |
234 | { | |
235 | return NULL; | |
236 | } | |
237 | ||
0ce8974d EB |
238 | static inline void unregister_sysctl_table(struct ctl_table_header * table) |
239 | { | |
240 | } | |
241 | ||
242 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 243 | struct ctl_table_root *root, |
0ce8974d EB |
244 | int (*is_seen)(struct ctl_table_set *)) |
245 | { | |
246 | } | |
247 | ||
3db978d4 VB |
248 | static inline void do_sysctl_args(void) |
249 | { | |
250 | } | |
0ce8974d EB |
251 | #endif /* CONFIG_SYSCTL */ |
252 | ||
32927393 CH |
253 | int sysctl_max_threads(struct ctl_table *table, int write, void *buffer, |
254 | size_t *lenp, loff_t *ppos); | |
16db3d3f | 255 | |
1da177e4 | 256 | #endif /* _LINUX_SYSCTL_H */ |