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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 | 58 | extern void mq_clear_sbinfo(struct ipc_namespace *ns); |
614b84cf | 59 | #else |
7eafd7c7 | 60 | static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } |
614b84cf SH |
61 | #endif |
62 | ||
63 | #ifdef CONFIG_SYSVIPC | |
eae04d25 | 64 | void sem_init_ns(struct ipc_namespace *ns); |
72d1e611 | 65 | int msg_init_ns(struct ipc_namespace *ns); |
eae04d25 | 66 | void shm_init_ns(struct ipc_namespace *ns); |
73ea4130 KK |
67 | |
68 | void sem_exit_ns(struct ipc_namespace *ns); | |
69 | void msg_exit_ns(struct ipc_namespace *ns); | |
70 | void shm_exit_ns(struct ipc_namespace *ns); | |
614b84cf | 71 | #else |
eae04d25 | 72 | static inline void sem_init_ns(struct ipc_namespace *ns) { } |
72d1e611 | 73 | static inline int msg_init_ns(struct ipc_namespace *ns) { return 0; } |
eae04d25 | 74 | static inline void shm_init_ns(struct ipc_namespace *ns) { } |
614b84cf SH |
75 | |
76 | static inline void sem_exit_ns(struct ipc_namespace *ns) { } | |
77 | static inline void msg_exit_ns(struct ipc_namespace *ns) { } | |
78 | static inline void shm_exit_ns(struct ipc_namespace *ns) { } | |
79 | #endif | |
73ea4130 | 80 | |
7748dbfa ND |
81 | /* |
82 | * Structure that holds the parameters needed by the ipc operations | |
83 | * (see after) | |
84 | */ | |
85 | struct ipc_params { | |
86 | key_t key; | |
87 | int flg; | |
88 | union { | |
89 | size_t size; /* for shared memories */ | |
90 | int nsems; /* for semaphores */ | |
91 | } u; /* holds the getnew() specific param */ | |
92 | }; | |
93 | ||
94 | /* | |
95 | * Structure that holds some ipc operations. This structure is used to unify | |
96 | * the calls to sys_msgget(), sys_semget(), sys_shmget() | |
97 | * . routine to call to create a new ipc object. Can be one of newque, | |
98 | * newary, newseg | |
f4566f04 | 99 | * . routine to call to check permissions for a new ipc object. |
7748dbfa ND |
100 | * Can be one of security_msg_associate, security_sem_associate, |
101 | * security_shm_associate | |
102 | * . routine to call for an extra check if needed | |
103 | */ | |
104 | struct ipc_ops { | |
46c0a8ca PM |
105 | int (*getnew)(struct ipc_namespace *, struct ipc_params *); |
106 | int (*associate)(struct kern_ipc_perm *, int); | |
107 | int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *); | |
7748dbfa ND |
108 | }; |
109 | ||
ae781774 | 110 | struct seq_file; |
ed2ddbf8 | 111 | struct ipc_ids; |
7d69a1f4 | 112 | |
eae04d25 | 113 | void ipc_init_ids(struct ipc_ids *ids); |
ae781774 MW |
114 | #ifdef CONFIG_PROC_FS |
115 | void __init ipc_init_proc_interface(const char *path, const char *header, | |
73ea4130 | 116 | int ids, int (*show)(struct seq_file *, void *)); |
03f1fc09 | 117 | struct pid_namespace *ipc_seq_pid_ns(struct seq_file *); |
ae781774 MW |
118 | #else |
119 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) | |
120 | #endif | |
1da177e4 | 121 | |
73ea4130 KK |
122 | #define IPC_SEM_IDS 0 |
123 | #define IPC_MSG_IDS 1 | |
124 | #define IPC_SHM_IDS 2 | |
125 | ||
5ac893b8 | 126 | #define ipcid_to_idx(id) ((id) & IPCMNI_IDX_MASK) |
3278a2c2 MS |
127 | #define ipcid_to_seqx(id) ((id) >> ipcmni_seq_shift()) |
128 | #define ipcid_seq_max() (INT_MAX >> ipcmni_seq_shift()) | |
ce621f5b | 129 | |
d9a605e4 | 130 | /* must be called with ids->rwsem acquired for writing */ |
7ca7e564 | 131 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
3e148c79 | 132 | |
1da177e4 | 133 | /* must be called with both locks acquired. */ |
7ca7e564 | 134 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
1da177e4 | 135 | |
0cfb6aee GK |
136 | /* must be called with both locks acquired. */ |
137 | void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *); | |
138 | ||
f4566f04 | 139 | /* must be called with ipcp locked */ |
b0e77598 | 140 | int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); |
1da177e4 | 141 | |
15df03c8 | 142 | /** |
27c331a1 | 143 | * ipc_get_maxidx - get the highest assigned index |
15df03c8 DB |
144 | * @ids: ipc identifier set |
145 | * | |
b869d5be MS |
146 | * The function returns the highest assigned index for @ids. The function |
147 | * doesn't scan the idr tree, it uses a cached value. | |
148 | * | |
15df03c8 DB |
149 | * Called with ipc_ids.rwsem held for reading. |
150 | */ | |
27c331a1 | 151 | static inline int ipc_get_maxidx(struct ipc_ids *ids) |
15df03c8 DB |
152 | { |
153 | if (ids->in_use == 0) | |
154 | return -1; | |
155 | ||
5ac893b8 WL |
156 | if (ids->in_use == ipc_mni) |
157 | return ipc_mni - 1; | |
15df03c8 | 158 | |
27c331a1 | 159 | return ids->max_idx; |
15df03c8 DB |
160 | } |
161 | ||
1da177e4 LT |
162 | /* |
163 | * For allocation that need to be freed by RCU. | |
164 | * Objects are reference counted, they start with reference count 1. | |
165 | * getref increases the refcount, the putref call that reduces the recount | |
166 | * to 0 schedules the rcu destruction. Caller must guarantee locking. | |
62b49c99 MS |
167 | * |
168 | * refcount is initialized by ipc_addid(), before that point call_rcu() | |
169 | * must be used. | |
1da177e4 | 170 | */ |
2a9d6481 | 171 | bool ipc_rcu_getref(struct kern_ipc_perm *ptr); |
dba4cdd3 MS |
172 | void ipc_rcu_putref(struct kern_ipc_perm *ptr, |
173 | void (*func)(struct rcu_head *head)); | |
1da177e4 | 174 | |
55b7ae50 | 175 | struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |
1da177e4 LT |
176 | |
177 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); | |
178 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); | |
1efdb69b | 179 | int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); |
4241c1a3 | 180 | struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, |
444d0f62 DB |
181 | struct ipc_ids *ids, int id, int cmd, |
182 | struct ipc64_perm *perm, int extra_perm); | |
1da177e4 | 183 | |
03f1fc09 EB |
184 | static inline void ipc_update_pid(struct pid **pos, struct pid *pid) |
185 | { | |
186 | struct pid *old = *pos; | |
187 | if (old != pid) { | |
188 | *pos = get_pid(pid); | |
189 | put_pid(old); | |
190 | } | |
191 | } | |
192 | ||
275f2214 | 193 | #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
239521f3 | 194 | int ipc_parse_version(int *cmd); |
1da177e4 LT |
195 | #endif |
196 | ||
197 | extern void free_msg(struct msg_msg *msg); | |
4e9b45a1 | 198 | extern struct msg_msg *load_msg(const void __user *src, size_t len); |
4a674f34 | 199 | extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst); |
4e9b45a1 | 200 | extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len); |
7748dbfa | 201 | |
27c331a1 | 202 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id) |
023a5355 | 203 | { |
27c331a1 | 204 | return ipcid_to_seqx(id) != ipcp->seq; |
023a5355 ND |
205 | } |
206 | ||
1ca7003a | 207 | static inline void ipc_lock_object(struct kern_ipc_perm *perm) |
023a5355 | 208 | { |
023a5355 ND |
209 | spin_lock(&perm->lock); |
210 | } | |
211 | ||
1ca7003a | 212 | static inline void ipc_unlock_object(struct kern_ipc_perm *perm) |
023a5355 ND |
213 | { |
214 | spin_unlock(&perm->lock); | |
023a5355 ND |
215 | } |
216 | ||
1ca7003a | 217 | static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm) |
16df3674 | 218 | { |
1ca7003a DB |
219 | assert_spin_locked(&perm->lock); |
220 | } | |
221 | ||
1ca7003a DB |
222 | static inline void ipc_unlock(struct kern_ipc_perm *perm) |
223 | { | |
cf9d5d78 | 224 | ipc_unlock_object(perm); |
1ca7003a DB |
225 | rcu_read_unlock(); |
226 | } | |
227 | ||
0f3d2b01 RA |
228 | /* |
229 | * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths | |
230 | * where the respective ipc_ids.rwsem is not being held down. | |
231 | * Checks whether the ipc object is still around or if it's gone already, as | |
232 | * ipc_rmid() may have already freed the ID while the ipc lock was spinning. | |
233 | * Needs to be called with kern_ipc_perm.lock held -- exception made for one | |
234 | * checkpoint case at sys_semtimedop() as noted in code commentary. | |
235 | */ | |
236 | static inline bool ipc_valid_object(struct kern_ipc_perm *perm) | |
237 | { | |
72a8ff2f | 238 | return !perm->deleted; |
0f3d2b01 RA |
239 | } |
240 | ||
4d2bff5e | 241 | struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id); |
b2d75cdd | 242 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44 | 243 | const struct ipc_ops *ops, struct ipc_params *params); |
665c7741 AD |
244 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
245 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); | |
553f770e | 246 | |
8c81ddd2 WL |
247 | static inline int sem_check_semmni(struct ipc_namespace *ns) { |
248 | /* | |
5ac893b8 | 249 | * Check semmni range [0, ipc_mni] |
8c81ddd2 WL |
250 | * semmni is the last element of sem_ctls[4] array |
251 | */ | |
5ac893b8 | 252 | return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni)) |
8c81ddd2 WL |
253 | ? -ERANGE : 0; |
254 | } | |
255 | ||
553f770e AV |
256 | #ifdef CONFIG_COMPAT |
257 | #include <linux/compat.h> | |
258 | struct compat_ipc_perm { | |
259 | key_t key; | |
260 | __compat_uid_t uid; | |
261 | __compat_gid_t gid; | |
262 | __compat_uid_t cuid; | |
263 | __compat_gid_t cgid; | |
264 | compat_mode_t mode; | |
265 | unsigned short seq; | |
266 | }; | |
267 | ||
c0ebccb6 AV |
268 | void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *); |
269 | void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *); | |
270 | int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *); | |
271 | int get_compat_ipc64_perm(struct ipc64_perm *, | |
272 | struct compat_ipc64_perm __user *); | |
273 | ||
553f770e AV |
274 | static inline int compat_ipc_parse_version(int *cmd) |
275 | { | |
553f770e AV |
276 | int version = *cmd & IPC_64; |
277 | *cmd &= ~IPC_64; | |
278 | return version; | |
553f770e | 279 | } |
41f4f0e2 | 280 | |
275f2214 AB |
281 | long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg); |
282 | long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr); | |
078faac9 DB |
283 | long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, |
284 | compat_long_t msgtyp, int msgflg); | |
31c213f2 DB |
285 | long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp, |
286 | compat_ssize_t msgsz, int msgflg); | |
275f2214 | 287 | long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr); |
fb377eb8 AB |
288 | |
289 | #endif | |
41f4f0e2 | 290 | |
1da177e4 | 291 | #endif |