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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * linux/ipc/util.h | |
4 | * Copyright (C) 1999 Christoph Rohland | |
5 | * | |
624dffcb | 6 | * ipc helper functions (c) 1999 Manfred Spraul <[email protected]> |
73ea4130 KK |
7 | * namespaces support. 2006 OpenVZ, SWsoft Inc. |
8 | * Pavel Emelianov <[email protected]> | |
1da177e4 LT |
9 | */ |
10 | ||
11 | #ifndef _IPC_UTIL_H | |
12 | #define _IPC_UTIL_H | |
13 | ||
232086b1 | 14 | #include <linux/unistd.h> |
023a5355 | 15 | #include <linux/err.h> |
15df03c8 | 16 | #include <linux/ipc_namespace.h> |
7ca7e564 | 17 | |
5ac893b8 WL |
18 | /* |
19 | * The IPC ID contains 2 separate numbers - index and sequence number. | |
20 | * By default, | |
21 | * bits 0-14: index (32k, 15 bits) | |
22 | * bits 15-30: sequence number (64k, 16 bits) | |
23 | * | |
24 | * When IPCMNI extension mode is turned on, the composition changes: | |
25 | * bits 0-23: index (16M, 24 bits) | |
26 | * bits 24-30: sequence number (128, 7 bits) | |
27 | */ | |
28 | #define IPCMNI_SHIFT 15 | |
29 | #define IPCMNI_EXTEND_SHIFT 24 | |
99db46ea | 30 | #define IPCMNI_EXTEND_MIN_CYCLE (RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE) |
5ac893b8 WL |
31 | #define IPCMNI (1 << IPCMNI_SHIFT) |
32 | #define IPCMNI_EXTEND (1 << IPCMNI_EXTEND_SHIFT) | |
33 | ||
34 | #ifdef CONFIG_SYSVIPC_SYSCTL | |
35 | extern int ipc_mni; | |
36 | extern int ipc_mni_shift; | |
99db46ea | 37 | extern int ipc_min_cycle; |
5ac893b8 | 38 | |
3278a2c2 | 39 | #define ipcmni_seq_shift() ipc_mni_shift |
5ac893b8 WL |
40 | #define IPCMNI_IDX_MASK ((1 << ipc_mni_shift) - 1) |
41 | ||
42 | #else /* CONFIG_SYSVIPC_SYSCTL */ | |
43 | ||
44 | #define ipc_mni IPCMNI | |
99db46ea | 45 | #define ipc_min_cycle ((int)RADIX_TREE_MAP_SIZE) |
3278a2c2 | 46 | #define ipcmni_seq_shift() IPCMNI_SHIFT |
5ac893b8 WL |
47 | #define IPCMNI_IDX_MASK ((1 << IPCMNI_SHIFT) - 1) |
48 | #endif /* CONFIG_SYSVIPC_SYSCTL */ | |
1da177e4 | 49 | |
eae04d25 DB |
50 | void sem_init(void); |
51 | void msg_init(void); | |
239521f3 | 52 | void shm_init(void); |
1da177e4 | 53 | |
ae5e1b22 | 54 | struct ipc_namespace; |
03f1fc09 | 55 | struct pid_namespace; |
ae5e1b22 | 56 | |
614b84cf | 57 | #ifdef CONFIG_POSIX_MQUEUE |
7eafd7c7 SH |
58 | extern void mq_clear_sbinfo(struct ipc_namespace *ns); |
59 | extern void mq_put_mnt(struct ipc_namespace *ns); | |
614b84cf | 60 | #else |
7eafd7c7 SH |
61 | static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } |
62 | static inline void mq_put_mnt(struct ipc_namespace *ns) { } | |
614b84cf SH |
63 | #endif |
64 | ||
65 | #ifdef CONFIG_SYSVIPC | |
eae04d25 DB |
66 | void sem_init_ns(struct ipc_namespace *ns); |
67 | void msg_init_ns(struct ipc_namespace *ns); | |
68 | void shm_init_ns(struct ipc_namespace *ns); | |
73ea4130 KK |
69 | |
70 | void sem_exit_ns(struct ipc_namespace *ns); | |
71 | void msg_exit_ns(struct ipc_namespace *ns); | |
72 | void shm_exit_ns(struct ipc_namespace *ns); | |
614b84cf | 73 | #else |
eae04d25 DB |
74 | static inline void sem_init_ns(struct ipc_namespace *ns) { } |
75 | static inline void msg_init_ns(struct ipc_namespace *ns) { } | |
76 | static inline void shm_init_ns(struct ipc_namespace *ns) { } | |
614b84cf SH |
77 | |
78 | static inline void sem_exit_ns(struct ipc_namespace *ns) { } | |
79 | static inline void msg_exit_ns(struct ipc_namespace *ns) { } | |
80 | static inline void shm_exit_ns(struct ipc_namespace *ns) { } | |
81 | #endif | |
73ea4130 | 82 | |
7748dbfa ND |
83 | /* |
84 | * Structure that holds the parameters needed by the ipc operations | |
85 | * (see after) | |
86 | */ | |
87 | struct ipc_params { | |
88 | key_t key; | |
89 | int flg; | |
90 | union { | |
91 | size_t size; /* for shared memories */ | |
92 | int nsems; /* for semaphores */ | |
93 | } u; /* holds the getnew() specific param */ | |
94 | }; | |
95 | ||
96 | /* | |
97 | * Structure that holds some ipc operations. This structure is used to unify | |
98 | * the calls to sys_msgget(), sys_semget(), sys_shmget() | |
99 | * . routine to call to create a new ipc object. Can be one of newque, | |
100 | * newary, newseg | |
f4566f04 | 101 | * . routine to call to check permissions for a new ipc object. |
7748dbfa ND |
102 | * Can be one of security_msg_associate, security_sem_associate, |
103 | * security_shm_associate | |
104 | * . routine to call for an extra check if needed | |
105 | */ | |
106 | struct ipc_ops { | |
46c0a8ca PM |
107 | int (*getnew)(struct ipc_namespace *, struct ipc_params *); |
108 | int (*associate)(struct kern_ipc_perm *, int); | |
109 | int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *); | |
7748dbfa ND |
110 | }; |
111 | ||
ae781774 | 112 | struct seq_file; |
ed2ddbf8 | 113 | struct ipc_ids; |
7d69a1f4 | 114 | |
eae04d25 | 115 | void ipc_init_ids(struct ipc_ids *ids); |
ae781774 MW |
116 | #ifdef CONFIG_PROC_FS |
117 | void __init ipc_init_proc_interface(const char *path, const char *header, | |
73ea4130 | 118 | int ids, int (*show)(struct seq_file *, void *)); |
03f1fc09 | 119 | struct pid_namespace *ipc_seq_pid_ns(struct seq_file *); |
ae781774 MW |
120 | #else |
121 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) | |
122 | #endif | |
1da177e4 | 123 | |
73ea4130 KK |
124 | #define IPC_SEM_IDS 0 |
125 | #define IPC_MSG_IDS 1 | |
126 | #define IPC_SHM_IDS 2 | |
127 | ||
5ac893b8 | 128 | #define ipcid_to_idx(id) ((id) & IPCMNI_IDX_MASK) |
3278a2c2 MS |
129 | #define ipcid_to_seqx(id) ((id) >> ipcmni_seq_shift()) |
130 | #define ipcid_seq_max() (INT_MAX >> ipcmni_seq_shift()) | |
ce621f5b | 131 | |
d9a605e4 | 132 | /* must be called with ids->rwsem acquired for writing */ |
7ca7e564 | 133 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
3e148c79 | 134 | |
1da177e4 | 135 | /* must be called with both locks acquired. */ |
7ca7e564 | 136 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
1da177e4 | 137 | |
0cfb6aee GK |
138 | /* must be called with both locks acquired. */ |
139 | void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *); | |
140 | ||
f4566f04 | 141 | /* must be called with ipcp locked */ |
b0e77598 | 142 | int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); |
1da177e4 | 143 | |
15df03c8 | 144 | /** |
27c331a1 | 145 | * ipc_get_maxidx - get the highest assigned index |
15df03c8 DB |
146 | * @ids: ipc identifier set |
147 | * | |
148 | * Called with ipc_ids.rwsem held for reading. | |
149 | */ | |
27c331a1 | 150 | static inline int ipc_get_maxidx(struct ipc_ids *ids) |
15df03c8 DB |
151 | { |
152 | if (ids->in_use == 0) | |
153 | return -1; | |
154 | ||
5ac893b8 WL |
155 | if (ids->in_use == ipc_mni) |
156 | return ipc_mni - 1; | |
15df03c8 | 157 | |
27c331a1 | 158 | return ids->max_idx; |
15df03c8 DB |
159 | } |
160 | ||
1da177e4 LT |
161 | /* |
162 | * For allocation that need to be freed by RCU. | |
163 | * Objects are reference counted, they start with reference count 1. | |
164 | * getref increases the refcount, the putref call that reduces the recount | |
165 | * to 0 schedules the rcu destruction. Caller must guarantee locking. | |
62b49c99 MS |
166 | * |
167 | * refcount is initialized by ipc_addid(), before that point call_rcu() | |
168 | * must be used. | |
1da177e4 | 169 | */ |
2a9d6481 | 170 | bool ipc_rcu_getref(struct kern_ipc_perm *ptr); |
dba4cdd3 MS |
171 | void ipc_rcu_putref(struct kern_ipc_perm *ptr, |
172 | void (*func)(struct rcu_head *head)); | |
1da177e4 | 173 | |
55b7ae50 | 174 | struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |
1da177e4 LT |
175 | |
176 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); | |
177 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); | |
1efdb69b | 178 | int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); |
4241c1a3 | 179 | struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, |
444d0f62 DB |
180 | struct ipc_ids *ids, int id, int cmd, |
181 | struct ipc64_perm *perm, int extra_perm); | |
1da177e4 | 182 | |
03f1fc09 EB |
183 | static inline void ipc_update_pid(struct pid **pos, struct pid *pid) |
184 | { | |
185 | struct pid *old = *pos; | |
186 | if (old != pid) { | |
187 | *pos = get_pid(pid); | |
188 | put_pid(old); | |
189 | } | |
190 | } | |
191 | ||
275f2214 | 192 | #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
239521f3 | 193 | int ipc_parse_version(int *cmd); |
1da177e4 LT |
194 | #endif |
195 | ||
196 | extern void free_msg(struct msg_msg *msg); | |
4e9b45a1 | 197 | extern struct msg_msg *load_msg(const void __user *src, size_t len); |
4a674f34 | 198 | extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst); |
4e9b45a1 | 199 | extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len); |
7748dbfa | 200 | |
27c331a1 | 201 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id) |
023a5355 | 202 | { |
27c331a1 | 203 | return ipcid_to_seqx(id) != ipcp->seq; |
023a5355 ND |
204 | } |
205 | ||
1ca7003a | 206 | static inline void ipc_lock_object(struct kern_ipc_perm *perm) |
023a5355 | 207 | { |
023a5355 ND |
208 | spin_lock(&perm->lock); |
209 | } | |
210 | ||
1ca7003a | 211 | static inline void ipc_unlock_object(struct kern_ipc_perm *perm) |
023a5355 ND |
212 | { |
213 | spin_unlock(&perm->lock); | |
023a5355 ND |
214 | } |
215 | ||
1ca7003a | 216 | static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm) |
16df3674 | 217 | { |
1ca7003a DB |
218 | assert_spin_locked(&perm->lock); |
219 | } | |
220 | ||
1ca7003a DB |
221 | static inline void ipc_unlock(struct kern_ipc_perm *perm) |
222 | { | |
cf9d5d78 | 223 | ipc_unlock_object(perm); |
1ca7003a DB |
224 | rcu_read_unlock(); |
225 | } | |
226 | ||
0f3d2b01 RA |
227 | /* |
228 | * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths | |
229 | * where the respective ipc_ids.rwsem is not being held down. | |
230 | * Checks whether the ipc object is still around or if it's gone already, as | |
231 | * ipc_rmid() may have already freed the ID while the ipc lock was spinning. | |
232 | * Needs to be called with kern_ipc_perm.lock held -- exception made for one | |
233 | * checkpoint case at sys_semtimedop() as noted in code commentary. | |
234 | */ | |
235 | static inline bool ipc_valid_object(struct kern_ipc_perm *perm) | |
236 | { | |
72a8ff2f | 237 | return !perm->deleted; |
0f3d2b01 RA |
238 | } |
239 | ||
4d2bff5e | 240 | struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id); |
b2d75cdd | 241 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44 | 242 | const struct ipc_ops *ops, struct ipc_params *params); |
665c7741 AD |
243 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
244 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); | |
553f770e | 245 | |
8c81ddd2 WL |
246 | static inline int sem_check_semmni(struct ipc_namespace *ns) { |
247 | /* | |
5ac893b8 | 248 | * Check semmni range [0, ipc_mni] |
8c81ddd2 WL |
249 | * semmni is the last element of sem_ctls[4] array |
250 | */ | |
5ac893b8 | 251 | return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni)) |
8c81ddd2 WL |
252 | ? -ERANGE : 0; |
253 | } | |
254 | ||
553f770e AV |
255 | #ifdef CONFIG_COMPAT |
256 | #include <linux/compat.h> | |
257 | struct compat_ipc_perm { | |
258 | key_t key; | |
259 | __compat_uid_t uid; | |
260 | __compat_gid_t gid; | |
261 | __compat_uid_t cuid; | |
262 | __compat_gid_t cgid; | |
263 | compat_mode_t mode; | |
264 | unsigned short seq; | |
265 | }; | |
266 | ||
c0ebccb6 AV |
267 | void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *); |
268 | void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *); | |
269 | int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *); | |
270 | int get_compat_ipc64_perm(struct ipc64_perm *, | |
271 | struct compat_ipc64_perm __user *); | |
272 | ||
553f770e AV |
273 | static inline int compat_ipc_parse_version(int *cmd) |
274 | { | |
553f770e AV |
275 | int version = *cmd & IPC_64; |
276 | *cmd &= ~IPC_64; | |
277 | return version; | |
553f770e | 278 | } |
41f4f0e2 | 279 | |
275f2214 AB |
280 | long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg); |
281 | long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr); | |
078faac9 DB |
282 | long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, |
283 | compat_long_t msgtyp, int msgflg); | |
31c213f2 DB |
284 | long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp, |
285 | compat_ssize_t msgsz, int msgflg); | |
275f2214 | 286 | long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr); |
fb377eb8 AB |
287 | |
288 | #endif | |
41f4f0e2 | 289 | |
1da177e4 | 290 | #endif |