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 MC |
40 | /* Keep the same order as in fs/proc/proc_sysctl.c */ |
41 | #define SYSCTL_ZERO ((void *)&sysctl_vals[0]) | |
42 | #define SYSCTL_ONE ((void *)&sysctl_vals[1]) | |
43 | #define SYSCTL_INT_MAX ((void *)&sysctl_vals[2]) | |
44 | ||
45 | extern const int sysctl_vals[]; | |
46 | ||
32927393 CH |
47 | typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer, |
48 | size_t *lenp, loff_t *ppos); | |
49 | ||
50 | int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *); | |
a2071573 JH |
51 | int proc_dobool(struct ctl_table *table, int write, void *buffer, |
52 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
53 | int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *); |
54 | int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *); | |
55 | int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
56 | int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer, | |
57 | size_t *lenp, loff_t *ppos); | |
cb944413 ED |
58 | int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer, |
59 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
60 | int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *); |
61 | int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *, | |
62 | loff_t *); | |
63 | int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *, | |
64 | loff_t *); | |
65 | int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
66 | int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *, | |
67 | size_t *, loff_t *); | |
68 | int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *); | |
69 | int proc_do_static_key(struct ctl_table *table, int write, void *buffer, | |
70 | size_t *lenp, loff_t *ppos); | |
1da177e4 | 71 | |
1da177e4 LT |
72 | /* |
73 | * Register a set of sysctl names by calling register_sysctl_table | |
2315ffa0 EB |
74 | * with an initialised array of struct ctl_table's. An entry with |
75 | * NULL procname terminates the table. table->de will be | |
d99f160a | 76 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
77 | * |
78 | * sysctl names can be mirrored automatically under /proc/sys. The | |
79 | * procname supplied controls /proc naming. | |
80 | * | |
88db0aa2 | 81 | * The table's mode will be honoured for proc-fs access. |
1da177e4 LT |
82 | * |
83 | * Leaf nodes in the sysctl tree will be represented by a single file | |
84 | * under /proc; non-leaf nodes will be represented by directories. A | |
85 | * null procname disables /proc mirroring at this node. | |
d99f160a | 86 | * |
88db0aa2 | 87 | * The data and maxlen fields of the ctl_table |
1da177e4 LT |
88 | * struct enable minimal validation of the values being written to be |
89 | * performed, and the mode field allows minimal authentication. | |
90 | * | |
1da177e4 LT |
91 | * There must be a proc_handler routine for any terminal nodes |
92 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
93 | * directory handler). Several default handlers are available to | |
94 | * cover common cases. | |
95 | */ | |
96 | ||
f1ecf068 LDM |
97 | /* Support for userspace poll() to watch for changes */ |
98 | struct ctl_table_poll { | |
99 | atomic_t event; | |
100 | wait_queue_head_t wait; | |
101 | }; | |
102 | ||
103 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
104 | { | |
105 | return (void *)(unsigned long)atomic_read(&poll->event); | |
106 | } | |
107 | ||
f1ecf068 LDM |
108 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
109 | .event = ATOMIC_INIT(0), \ | |
110 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
111 | ||
112 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
113 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
114 | ||
1da177e4 | 115 | /* A sysctl table is an array of struct ctl_table: */ |
d5ffb71b | 116 | struct ctl_table { |
1da177e4 LT |
117 | const char *procname; /* Text ID for /proc/sys, or zero */ |
118 | void *data; | |
119 | int maxlen; | |
36fcb589 | 120 | umode_t mode; |
f728019b | 121 | struct ctl_table *child; /* Deprecated */ |
1da177e4 | 122 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 123 | struct ctl_table_poll *poll; |
1da177e4 LT |
124 | void *extra1; |
125 | void *extra2; | |
3859a271 | 126 | } __randomize_layout; |
1da177e4 | 127 | |
ac13ac6f EB |
128 | struct ctl_node { |
129 | struct rb_node node; | |
130 | struct ctl_table_header *header; | |
131 | }; | |
132 | ||
1da177e4 | 133 | /* struct ctl_table_header is used to maintain dynamic lists of |
d8217f07 | 134 | struct ctl_table trees. */ |
d5ffb71b | 135 | struct ctl_table_header { |
dfef6dcd AV |
136 | union { |
137 | struct { | |
138 | struct ctl_table *ctl_table; | |
dfef6dcd AV |
139 | int used; |
140 | int count; | |
938aaa4f | 141 | int nreg; |
dfef6dcd AV |
142 | }; |
143 | struct rcu_head rcu; | |
144 | }; | |
330d57fb | 145 | struct completion *unregistering; |
23eb06de | 146 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 147 | struct ctl_table_root *root; |
73455092 | 148 | struct ctl_table_set *set; |
7ec66d06 | 149 | struct ctl_dir *parent; |
ac13ac6f | 150 | struct ctl_node *node; |
2fd1d2c4 | 151 | struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ |
7ec66d06 EB |
152 | }; |
153 | ||
154 | struct ctl_dir { | |
155 | /* Header must be at the start of ctl_dir */ | |
156 | struct ctl_table_header header; | |
ac13ac6f | 157 | struct rb_root root; |
1da177e4 LT |
158 | }; |
159 | ||
0ce8974d | 160 | struct ctl_table_set { |
0ce8974d | 161 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 162 | struct ctl_dir dir; |
0ce8974d EB |
163 | }; |
164 | ||
165 | struct ctl_table_root { | |
0ce8974d | 166 | struct ctl_table_set default_set; |
13bcc6a2 | 167 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
e79c6a4f DT |
168 | void (*set_ownership)(struct ctl_table_header *head, |
169 | struct ctl_table *table, | |
170 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 171 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
172 | }; |
173 | ||
29e796fd EB |
174 | /* struct ctl_path describes where in the hierarchy a table is added */ |
175 | struct ctl_path { | |
176 | const char *procname; | |
29e796fd EB |
177 | }; |
178 | ||
0ce8974d EB |
179 | #ifdef CONFIG_SYSCTL |
180 | ||
181 | void proc_sys_poll_notify(struct ctl_table_poll *poll); | |
182 | ||
183 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 184 | struct ctl_table_root *root, |
0ce8974d | 185 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 186 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 187 | |
6e9d5164 | 188 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 189 | struct ctl_table_set *set, |
6e9d5164 | 190 | const char *path, struct ctl_table *table); |
e51b6ba0 | 191 | struct ctl_table_header *__register_sysctl_paths( |
60a47a2e | 192 | struct ctl_table_set *set, |
e51b6ba0 | 193 | const struct ctl_path *path, struct ctl_table *table); |
fea478d4 | 194 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); |
d8217f07 | 195 | struct ctl_table_header *register_sysctl_table(struct ctl_table * table); |
29e796fd EB |
196 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
197 | struct ctl_table *table); | |
0b4d4147 | 198 | |
1da177e4 LT |
199 | void unregister_sysctl_table(struct ctl_table_header * table); |
200 | ||
de4e83bd | 201 | extern int sysctl_init(void); |
3db978d4 | 202 | void do_sysctl_args(void); |
f9bd6733 | 203 | |
2374c09b CH |
204 | extern int pwrsw_enabled; |
205 | extern int unaligned_enabled; | |
206 | extern int unaligned_dump_stack; | |
207 | extern int no_unaligned_warning; | |
208 | ||
f9bd6733 | 209 | extern struct ctl_table sysctl_mount_point[]; |
2374c09b CH |
210 | extern struct ctl_table random_table[]; |
211 | extern struct ctl_table firmware_config_table[]; | |
212 | extern struct ctl_table epoll_table[]; | |
f9bd6733 | 213 | |
0ce8974d EB |
214 | #else /* CONFIG_SYSCTL */ |
215 | static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) | |
216 | { | |
217 | return NULL; | |
218 | } | |
219 | ||
220 | static inline struct ctl_table_header *register_sysctl_paths( | |
221 | const struct ctl_path *path, struct ctl_table *table) | |
222 | { | |
223 | return NULL; | |
224 | } | |
225 | ||
e609a6b8 AB |
226 | static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) |
227 | { | |
228 | return NULL; | |
229 | } | |
230 | ||
0ce8974d EB |
231 | static inline void unregister_sysctl_table(struct ctl_table_header * table) |
232 | { | |
233 | } | |
234 | ||
235 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 236 | struct ctl_table_root *root, |
0ce8974d EB |
237 | int (*is_seen)(struct ctl_table_set *)) |
238 | { | |
239 | } | |
240 | ||
3db978d4 VB |
241 | static inline void do_sysctl_args(void) |
242 | { | |
243 | } | |
0ce8974d EB |
244 | #endif /* CONFIG_SYSCTL */ |
245 | ||
32927393 CH |
246 | int sysctl_max_threads(struct ctl_table *table, int write, void *buffer, |
247 | size_t *lenp, loff_t *ppos); | |
16db3d3f | 248 | |
1da177e4 | 249 | #endif /* _LINUX_SYSCTL_H */ |