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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> |
f551103c | 17 | #include <linux/pid.h> |
7ca7e564 | 18 | |
5ac893b8 WL |
19 | /* |
20 | * The IPC ID contains 2 separate numbers - index and sequence number. | |
21 | * By default, | |
22 | * bits 0-14: index (32k, 15 bits) | |
23 | * bits 15-30: sequence number (64k, 16 bits) | |
24 | * | |
25 | * When IPCMNI extension mode is turned on, the composition changes: | |
26 | * bits 0-23: index (16M, 24 bits) | |
27 | * bits 24-30: sequence number (128, 7 bits) | |
28 | */ | |
29 | #define IPCMNI_SHIFT 15 | |
30 | #define IPCMNI_EXTEND_SHIFT 24 | |
99db46ea | 31 | #define IPCMNI_EXTEND_MIN_CYCLE (RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE) |
5ac893b8 WL |
32 | #define IPCMNI (1 << IPCMNI_SHIFT) |
33 | #define IPCMNI_EXTEND (1 << IPCMNI_EXTEND_SHIFT) | |
34 | ||
35 | #ifdef CONFIG_SYSVIPC_SYSCTL | |
36 | extern int ipc_mni; | |
37 | extern int ipc_mni_shift; | |
99db46ea | 38 | extern int ipc_min_cycle; |
5ac893b8 | 39 | |
3278a2c2 | 40 | #define ipcmni_seq_shift() ipc_mni_shift |
5ac893b8 WL |
41 | #define IPCMNI_IDX_MASK ((1 << ipc_mni_shift) - 1) |
42 | ||
43 | #else /* CONFIG_SYSVIPC_SYSCTL */ | |
44 | ||
45 | #define ipc_mni IPCMNI | |
99db46ea | 46 | #define ipc_min_cycle ((int)RADIX_TREE_MAP_SIZE) |
3278a2c2 | 47 | #define ipcmni_seq_shift() IPCMNI_SHIFT |
5ac893b8 WL |
48 | #define IPCMNI_IDX_MASK ((1 << IPCMNI_SHIFT) - 1) |
49 | #endif /* CONFIG_SYSVIPC_SYSCTL */ | |
1da177e4 | 50 | |
eae04d25 DB |
51 | void sem_init(void); |
52 | void msg_init(void); | |
239521f3 | 53 | void shm_init(void); |
1da177e4 | 54 | |
ae5e1b22 | 55 | struct ipc_namespace; |
03f1fc09 | 56 | struct pid_namespace; |
ae5e1b22 | 57 | |
614b84cf | 58 | #ifdef CONFIG_POSIX_MQUEUE |
7eafd7c7 | 59 | extern void mq_clear_sbinfo(struct ipc_namespace *ns); |
614b84cf | 60 | #else |
7eafd7c7 | 61 | static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } |
614b84cf SH |
62 | #endif |
63 | ||
64 | #ifdef CONFIG_SYSVIPC | |
eae04d25 | 65 | void sem_init_ns(struct ipc_namespace *ns); |
72d1e611 | 66 | int msg_init_ns(struct ipc_namespace *ns); |
eae04d25 | 67 | void shm_init_ns(struct ipc_namespace *ns); |
73ea4130 KK |
68 | |
69 | void sem_exit_ns(struct ipc_namespace *ns); | |
70 | void msg_exit_ns(struct ipc_namespace *ns); | |
71 | void shm_exit_ns(struct ipc_namespace *ns); | |
614b84cf | 72 | #else |
eae04d25 | 73 | static inline void sem_init_ns(struct ipc_namespace *ns) { } |
72d1e611 | 74 | static inline int msg_init_ns(struct ipc_namespace *ns) { return 0; } |
eae04d25 | 75 | static inline void shm_init_ns(struct ipc_namespace *ns) { } |
614b84cf SH |
76 | |
77 | static inline void sem_exit_ns(struct ipc_namespace *ns) { } | |
78 | static inline void msg_exit_ns(struct ipc_namespace *ns) { } | |
79 | static inline void shm_exit_ns(struct ipc_namespace *ns) { } | |
80 | #endif | |
73ea4130 | 81 | |
7748dbfa ND |
82 | /* |
83 | * Structure that holds the parameters needed by the ipc operations | |
84 | * (see after) | |
85 | */ | |
86 | struct ipc_params { | |
87 | key_t key; | |
88 | int flg; | |
89 | union { | |
90 | size_t size; /* for shared memories */ | |
91 | int nsems; /* for semaphores */ | |
92 | } u; /* holds the getnew() specific param */ | |
93 | }; | |
94 | ||
95 | /* | |
96 | * Structure that holds some ipc operations. This structure is used to unify | |
97 | * the calls to sys_msgget(), sys_semget(), sys_shmget() | |
98 | * . routine to call to create a new ipc object. Can be one of newque, | |
99 | * newary, newseg | |
f4566f04 | 100 | * . routine to call to check permissions for a new ipc object. |
7748dbfa ND |
101 | * Can be one of security_msg_associate, security_sem_associate, |
102 | * security_shm_associate | |
103 | * . routine to call for an extra check if needed | |
104 | */ | |
105 | struct ipc_ops { | |
46c0a8ca PM |
106 | int (*getnew)(struct ipc_namespace *, struct ipc_params *); |
107 | int (*associate)(struct kern_ipc_perm *, int); | |
108 | int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *); | |
7748dbfa ND |
109 | }; |
110 | ||
ae781774 | 111 | struct seq_file; |
ed2ddbf8 | 112 | struct ipc_ids; |
7d69a1f4 | 113 | |
eae04d25 | 114 | void ipc_init_ids(struct ipc_ids *ids); |
ae781774 MW |
115 | #ifdef CONFIG_PROC_FS |
116 | void __init ipc_init_proc_interface(const char *path, const char *header, | |
73ea4130 | 117 | int ids, int (*show)(struct seq_file *, void *)); |
03f1fc09 | 118 | struct pid_namespace *ipc_seq_pid_ns(struct seq_file *); |
ae781774 MW |
119 | #else |
120 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) | |
121 | #endif | |
1da177e4 | 122 | |
73ea4130 KK |
123 | #define IPC_SEM_IDS 0 |
124 | #define IPC_MSG_IDS 1 | |
125 | #define IPC_SHM_IDS 2 | |
126 | ||
5ac893b8 | 127 | #define ipcid_to_idx(id) ((id) & IPCMNI_IDX_MASK) |
3278a2c2 MS |
128 | #define ipcid_to_seqx(id) ((id) >> ipcmni_seq_shift()) |
129 | #define ipcid_seq_max() (INT_MAX >> ipcmni_seq_shift()) | |
ce621f5b | 130 | |
d9a605e4 | 131 | /* must be called with ids->rwsem acquired for writing */ |
7ca7e564 | 132 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
3e148c79 | 133 | |
1da177e4 | 134 | /* must be called with both locks acquired. */ |
7ca7e564 | 135 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
1da177e4 | 136 | |
0cfb6aee GK |
137 | /* must be called with both locks acquired. */ |
138 | void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *); | |
139 | ||
f4566f04 | 140 | /* must be called with ipcp locked */ |
b0e77598 | 141 | int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); |
1da177e4 | 142 | |
15df03c8 | 143 | /** |
27c331a1 | 144 | * ipc_get_maxidx - get the highest assigned index |
15df03c8 DB |
145 | * @ids: ipc identifier set |
146 | * | |
b869d5be MS |
147 | * The function returns the highest assigned index for @ids. The function |
148 | * doesn't scan the idr tree, it uses a cached value. | |
149 | * | |
15df03c8 DB |
150 | * Called with ipc_ids.rwsem held for reading. |
151 | */ | |
27c331a1 | 152 | static inline int ipc_get_maxidx(struct ipc_ids *ids) |
15df03c8 DB |
153 | { |
154 | if (ids->in_use == 0) | |
155 | return -1; | |
156 | ||
5ac893b8 WL |
157 | if (ids->in_use == ipc_mni) |
158 | return ipc_mni - 1; | |
15df03c8 | 159 | |
27c331a1 | 160 | return ids->max_idx; |
15df03c8 DB |
161 | } |
162 | ||
1da177e4 LT |
163 | /* |
164 | * For allocation that need to be freed by RCU. | |
165 | * Objects are reference counted, they start with reference count 1. | |
166 | * getref increases the refcount, the putref call that reduces the recount | |
167 | * to 0 schedules the rcu destruction. Caller must guarantee locking. | |
62b49c99 MS |
168 | * |
169 | * refcount is initialized by ipc_addid(), before that point call_rcu() | |
170 | * must be used. | |
1da177e4 | 171 | */ |
2a9d6481 | 172 | bool ipc_rcu_getref(struct kern_ipc_perm *ptr); |
dba4cdd3 MS |
173 | void ipc_rcu_putref(struct kern_ipc_perm *ptr, |
174 | void (*func)(struct rcu_head *head)); | |
1da177e4 | 175 | |
55b7ae50 | 176 | struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |
1da177e4 LT |
177 | |
178 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); | |
179 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); | |
1efdb69b | 180 | int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); |
4241c1a3 | 181 | struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, |
444d0f62 DB |
182 | struct ipc_ids *ids, int id, int cmd, |
183 | struct ipc64_perm *perm, int extra_perm); | |
1da177e4 | 184 | |
03f1fc09 EB |
185 | static inline void ipc_update_pid(struct pid **pos, struct pid *pid) |
186 | { | |
187 | struct pid *old = *pos; | |
188 | if (old != pid) { | |
189 | *pos = get_pid(pid); | |
190 | put_pid(old); | |
191 | } | |
192 | } | |
193 | ||
275f2214 | 194 | #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
239521f3 | 195 | int ipc_parse_version(int *cmd); |
1da177e4 LT |
196 | #endif |
197 | ||
198 | extern void free_msg(struct msg_msg *msg); | |
4e9b45a1 | 199 | extern struct msg_msg *load_msg(const void __user *src, size_t len); |
4a674f34 | 200 | extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst); |
4e9b45a1 | 201 | extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len); |
7748dbfa | 202 | |
27c331a1 | 203 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id) |
023a5355 | 204 | { |
27c331a1 | 205 | return ipcid_to_seqx(id) != ipcp->seq; |
023a5355 ND |
206 | } |
207 | ||
1ca7003a | 208 | static inline void ipc_lock_object(struct kern_ipc_perm *perm) |
023a5355 | 209 | { |
023a5355 ND |
210 | spin_lock(&perm->lock); |
211 | } | |
212 | ||
1ca7003a | 213 | static inline void ipc_unlock_object(struct kern_ipc_perm *perm) |
023a5355 ND |
214 | { |
215 | spin_unlock(&perm->lock); | |
023a5355 ND |
216 | } |
217 | ||
1ca7003a | 218 | static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm) |
16df3674 | 219 | { |
1ca7003a DB |
220 | assert_spin_locked(&perm->lock); |
221 | } | |
222 | ||
1ca7003a DB |
223 | static inline void ipc_unlock(struct kern_ipc_perm *perm) |
224 | { | |
cf9d5d78 | 225 | ipc_unlock_object(perm); |
1ca7003a DB |
226 | rcu_read_unlock(); |
227 | } | |
228 | ||
0f3d2b01 RA |
229 | /* |
230 | * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths | |
231 | * where the respective ipc_ids.rwsem is not being held down. | |
232 | * Checks whether the ipc object is still around or if it's gone already, as | |
233 | * ipc_rmid() may have already freed the ID while the ipc lock was spinning. | |
234 | * Needs to be called with kern_ipc_perm.lock held -- exception made for one | |
235 | * checkpoint case at sys_semtimedop() as noted in code commentary. | |
236 | */ | |
237 | static inline bool ipc_valid_object(struct kern_ipc_perm *perm) | |
238 | { | |
72a8ff2f | 239 | return !perm->deleted; |
0f3d2b01 RA |
240 | } |
241 | ||
4d2bff5e | 242 | struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id); |
b2d75cdd | 243 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44 | 244 | const struct ipc_ops *ops, struct ipc_params *params); |
665c7741 AD |
245 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
246 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); | |
553f770e | 247 | |
8c81ddd2 WL |
248 | static inline int sem_check_semmni(struct ipc_namespace *ns) { |
249 | /* | |
5ac893b8 | 250 | * Check semmni range [0, ipc_mni] |
8c81ddd2 WL |
251 | * semmni is the last element of sem_ctls[4] array |
252 | */ | |
5ac893b8 | 253 | return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni)) |
8c81ddd2 WL |
254 | ? -ERANGE : 0; |
255 | } | |
256 | ||
553f770e AV |
257 | #ifdef CONFIG_COMPAT |
258 | #include <linux/compat.h> | |
259 | struct compat_ipc_perm { | |
260 | key_t key; | |
261 | __compat_uid_t uid; | |
262 | __compat_gid_t gid; | |
263 | __compat_uid_t cuid; | |
264 | __compat_gid_t cgid; | |
265 | compat_mode_t mode; | |
266 | unsigned short seq; | |
267 | }; | |
268 | ||
c0ebccb6 AV |
269 | void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *); |
270 | void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *); | |
271 | int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *); | |
272 | int get_compat_ipc64_perm(struct ipc64_perm *, | |
273 | struct compat_ipc64_perm __user *); | |
274 | ||
553f770e AV |
275 | static inline int compat_ipc_parse_version(int *cmd) |
276 | { | |
553f770e AV |
277 | int version = *cmd & IPC_64; |
278 | *cmd &= ~IPC_64; | |
279 | return version; | |
553f770e | 280 | } |
41f4f0e2 | 281 | |
275f2214 AB |
282 | long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg); |
283 | long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr); | |
078faac9 DB |
284 | long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, |
285 | compat_long_t msgtyp, int msgflg); | |
31c213f2 DB |
286 | long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp, |
287 | compat_ssize_t msgsz, int msgflg); | |
275f2214 | 288 | long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr); |
fb377eb8 AB |
289 | |
290 | #endif | |
41f4f0e2 | 291 | |
1da177e4 | 292 | #endif |