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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 | |
f83a396d | 18 | #define IPCMNI 32768 /* <= MAX_INT limit for ipc arrays (including sysctl changes) */ |
1da177e4 LT |
19 | #define SEQ_MULTIPLIER (IPCMNI) |
20 | ||
eae04d25 DB |
21 | void sem_init(void); |
22 | void msg_init(void); | |
239521f3 | 23 | void shm_init(void); |
1da177e4 | 24 | |
ae5e1b22 | 25 | struct ipc_namespace; |
03f1fc09 | 26 | struct pid_namespace; |
ae5e1b22 | 27 | |
614b84cf | 28 | #ifdef CONFIG_POSIX_MQUEUE |
7eafd7c7 SH |
29 | extern void mq_clear_sbinfo(struct ipc_namespace *ns); |
30 | extern void mq_put_mnt(struct ipc_namespace *ns); | |
614b84cf | 31 | #else |
7eafd7c7 SH |
32 | static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } |
33 | static inline void mq_put_mnt(struct ipc_namespace *ns) { } | |
614b84cf SH |
34 | #endif |
35 | ||
36 | #ifdef CONFIG_SYSVIPC | |
eae04d25 DB |
37 | void sem_init_ns(struct ipc_namespace *ns); |
38 | void msg_init_ns(struct ipc_namespace *ns); | |
39 | void shm_init_ns(struct ipc_namespace *ns); | |
73ea4130 KK |
40 | |
41 | void sem_exit_ns(struct ipc_namespace *ns); | |
42 | void msg_exit_ns(struct ipc_namespace *ns); | |
43 | void shm_exit_ns(struct ipc_namespace *ns); | |
614b84cf | 44 | #else |
eae04d25 DB |
45 | static inline void sem_init_ns(struct ipc_namespace *ns) { } |
46 | static inline void msg_init_ns(struct ipc_namespace *ns) { } | |
47 | static inline void shm_init_ns(struct ipc_namespace *ns) { } | |
614b84cf SH |
48 | |
49 | static inline void sem_exit_ns(struct ipc_namespace *ns) { } | |
50 | static inline void msg_exit_ns(struct ipc_namespace *ns) { } | |
51 | static inline void shm_exit_ns(struct ipc_namespace *ns) { } | |
52 | #endif | |
73ea4130 | 53 | |
7748dbfa ND |
54 | /* |
55 | * Structure that holds the parameters needed by the ipc operations | |
56 | * (see after) | |
57 | */ | |
58 | struct ipc_params { | |
59 | key_t key; | |
60 | int flg; | |
61 | union { | |
62 | size_t size; /* for shared memories */ | |
63 | int nsems; /* for semaphores */ | |
64 | } u; /* holds the getnew() specific param */ | |
65 | }; | |
66 | ||
67 | /* | |
68 | * Structure that holds some ipc operations. This structure is used to unify | |
69 | * the calls to sys_msgget(), sys_semget(), sys_shmget() | |
70 | * . routine to call to create a new ipc object. Can be one of newque, | |
71 | * newary, newseg | |
f4566f04 | 72 | * . routine to call to check permissions for a new ipc object. |
7748dbfa ND |
73 | * Can be one of security_msg_associate, security_sem_associate, |
74 | * security_shm_associate | |
75 | * . routine to call for an extra check if needed | |
76 | */ | |
77 | struct ipc_ops { | |
46c0a8ca PM |
78 | int (*getnew)(struct ipc_namespace *, struct ipc_params *); |
79 | int (*associate)(struct kern_ipc_perm *, int); | |
80 | int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *); | |
7748dbfa ND |
81 | }; |
82 | ||
ae781774 | 83 | struct seq_file; |
ed2ddbf8 | 84 | struct ipc_ids; |
7d69a1f4 | 85 | |
eae04d25 | 86 | void ipc_init_ids(struct ipc_ids *ids); |
ae781774 MW |
87 | #ifdef CONFIG_PROC_FS |
88 | void __init ipc_init_proc_interface(const char *path, const char *header, | |
73ea4130 | 89 | int ids, int (*show)(struct seq_file *, void *)); |
03f1fc09 | 90 | struct pid_namespace *ipc_seq_pid_ns(struct seq_file *); |
ae781774 MW |
91 | #else |
92 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) | |
93 | #endif | |
1da177e4 | 94 | |
73ea4130 KK |
95 | #define IPC_SEM_IDS 0 |
96 | #define IPC_MSG_IDS 1 | |
97 | #define IPC_SHM_IDS 2 | |
98 | ||
ce621f5b | 99 | #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER) |
03f59566 | 100 | #define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER) |
daf948c7 | 101 | #define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX) |
ce621f5b | 102 | |
d9a605e4 | 103 | /* must be called with ids->rwsem acquired for writing */ |
7ca7e564 | 104 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
3e148c79 | 105 | |
1da177e4 | 106 | /* must be called with both locks acquired. */ |
7ca7e564 | 107 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
1da177e4 | 108 | |
0cfb6aee GK |
109 | /* must be called with both locks acquired. */ |
110 | void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *); | |
111 | ||
f4566f04 | 112 | /* must be called with ipcp locked */ |
b0e77598 | 113 | int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); |
1da177e4 | 114 | |
15df03c8 | 115 | /** |
27c331a1 | 116 | * ipc_get_maxidx - get the highest assigned index |
15df03c8 DB |
117 | * @ids: ipc identifier set |
118 | * | |
119 | * Called with ipc_ids.rwsem held for reading. | |
120 | */ | |
27c331a1 | 121 | static inline int ipc_get_maxidx(struct ipc_ids *ids) |
15df03c8 DB |
122 | { |
123 | if (ids->in_use == 0) | |
124 | return -1; | |
125 | ||
126 | if (ids->in_use == IPCMNI) | |
127 | return IPCMNI - 1; | |
128 | ||
27c331a1 | 129 | return ids->max_idx; |
15df03c8 DB |
130 | } |
131 | ||
1da177e4 LT |
132 | /* |
133 | * For allocation that need to be freed by RCU. | |
134 | * Objects are reference counted, they start with reference count 1. | |
135 | * getref increases the refcount, the putref call that reduces the recount | |
136 | * to 0 schedules the rcu destruction. Caller must guarantee locking. | |
62b49c99 MS |
137 | * |
138 | * refcount is initialized by ipc_addid(), before that point call_rcu() | |
139 | * must be used. | |
1da177e4 | 140 | */ |
2a9d6481 | 141 | bool ipc_rcu_getref(struct kern_ipc_perm *ptr); |
dba4cdd3 MS |
142 | void ipc_rcu_putref(struct kern_ipc_perm *ptr, |
143 | void (*func)(struct rcu_head *head)); | |
1da177e4 | 144 | |
55b7ae50 | 145 | struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |
1da177e4 LT |
146 | |
147 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); | |
148 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); | |
1efdb69b | 149 | int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); |
4241c1a3 | 150 | struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, |
444d0f62 DB |
151 | struct ipc_ids *ids, int id, int cmd, |
152 | struct ipc64_perm *perm, int extra_perm); | |
1da177e4 | 153 | |
03f1fc09 EB |
154 | static inline void ipc_update_pid(struct pid **pos, struct pid *pid) |
155 | { | |
156 | struct pid *old = *pos; | |
157 | if (old != pid) { | |
158 | *pos = get_pid(pid); | |
159 | put_pid(old); | |
160 | } | |
161 | } | |
162 | ||
c1d7e01d | 163 | #ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
46c0a8ca | 164 | /* On IA-64, we always use the "64-bit version" of the IPC structures. */ |
1da177e4 LT |
165 | # define ipc_parse_version(cmd) IPC_64 |
166 | #else | |
239521f3 | 167 | int ipc_parse_version(int *cmd); |
1da177e4 LT |
168 | #endif |
169 | ||
170 | extern void free_msg(struct msg_msg *msg); | |
4e9b45a1 | 171 | extern struct msg_msg *load_msg(const void __user *src, size_t len); |
4a674f34 | 172 | extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst); |
4e9b45a1 | 173 | extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len); |
7748dbfa | 174 | |
27c331a1 | 175 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id) |
023a5355 | 176 | { |
27c331a1 | 177 | return ipcid_to_seqx(id) != ipcp->seq; |
023a5355 ND |
178 | } |
179 | ||
1ca7003a | 180 | static inline void ipc_lock_object(struct kern_ipc_perm *perm) |
023a5355 | 181 | { |
023a5355 ND |
182 | spin_lock(&perm->lock); |
183 | } | |
184 | ||
1ca7003a | 185 | static inline void ipc_unlock_object(struct kern_ipc_perm *perm) |
023a5355 ND |
186 | { |
187 | spin_unlock(&perm->lock); | |
023a5355 ND |
188 | } |
189 | ||
1ca7003a | 190 | static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm) |
16df3674 | 191 | { |
1ca7003a DB |
192 | assert_spin_locked(&perm->lock); |
193 | } | |
194 | ||
1ca7003a DB |
195 | static inline void ipc_unlock(struct kern_ipc_perm *perm) |
196 | { | |
cf9d5d78 | 197 | ipc_unlock_object(perm); |
1ca7003a DB |
198 | rcu_read_unlock(); |
199 | } | |
200 | ||
0f3d2b01 RA |
201 | /* |
202 | * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths | |
203 | * where the respective ipc_ids.rwsem is not being held down. | |
204 | * Checks whether the ipc object is still around or if it's gone already, as | |
205 | * ipc_rmid() may have already freed the ID while the ipc lock was spinning. | |
206 | * Needs to be called with kern_ipc_perm.lock held -- exception made for one | |
207 | * checkpoint case at sys_semtimedop() as noted in code commentary. | |
208 | */ | |
209 | static inline bool ipc_valid_object(struct kern_ipc_perm *perm) | |
210 | { | |
72a8ff2f | 211 | return !perm->deleted; |
0f3d2b01 RA |
212 | } |
213 | ||
4d2bff5e | 214 | struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id); |
b2d75cdd | 215 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44 | 216 | const struct ipc_ops *ops, struct ipc_params *params); |
665c7741 AD |
217 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
218 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); | |
553f770e | 219 | |
8c81ddd2 WL |
220 | static inline int sem_check_semmni(struct ipc_namespace *ns) { |
221 | /* | |
222 | * Check semmni range [0, IPCMNI] | |
223 | * semmni is the last element of sem_ctls[4] array | |
224 | */ | |
225 | return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > IPCMNI)) | |
226 | ? -ERANGE : 0; | |
227 | } | |
228 | ||
553f770e AV |
229 | #ifdef CONFIG_COMPAT |
230 | #include <linux/compat.h> | |
231 | struct compat_ipc_perm { | |
232 | key_t key; | |
233 | __compat_uid_t uid; | |
234 | __compat_gid_t gid; | |
235 | __compat_uid_t cuid; | |
236 | __compat_gid_t cgid; | |
237 | compat_mode_t mode; | |
238 | unsigned short seq; | |
239 | }; | |
240 | ||
c0ebccb6 AV |
241 | void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *); |
242 | void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *); | |
243 | int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *); | |
244 | int get_compat_ipc64_perm(struct ipc64_perm *, | |
245 | struct compat_ipc64_perm __user *); | |
246 | ||
553f770e AV |
247 | static inline int compat_ipc_parse_version(int *cmd) |
248 | { | |
249 | #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION | |
250 | int version = *cmd & IPC_64; | |
251 | *cmd &= ~IPC_64; | |
252 | return version; | |
253 | #else | |
254 | return IPC_64; | |
255 | #endif | |
256 | } | |
257 | #endif | |
41f4f0e2 DB |
258 | |
259 | /* for __ARCH_WANT_SYS_IPC */ | |
260 | long ksys_semtimedop(int semid, struct sembuf __user *tsops, | |
261 | unsigned int nsops, | |
21fc538d | 262 | const struct __kernel_timespec __user *timeout); |
69894718 | 263 | long ksys_semget(key_t key, int nsems, int semflg); |
d969c6fa | 264 | long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg); |
3d65661a | 265 | long ksys_msgget(key_t key, int msgflg); |
e340db56 | 266 | long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf); |
078faac9 DB |
267 | long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
268 | long msgtyp, int msgflg); | |
31c213f2 DB |
269 | long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
270 | int msgflg); | |
65749e0b | 271 | long ksys_shmget(key_t key, size_t size, int shmflg); |
da1e2744 | 272 | long ksys_shmdt(char __user *shmaddr); |
c84d0791 | 273 | long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf); |
41f4f0e2 DB |
274 | |
275 | /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */ | |
41f4f0e2 DB |
276 | long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems, |
277 | unsigned int nsops, | |
9afc5eee | 278 | const struct old_timespec32 __user *timeout); |
b0d17578 | 279 | #ifdef CONFIG_COMPAT |
d969c6fa | 280 | long compat_ksys_semctl(int semid, int semnum, int cmd, int arg); |
e340db56 | 281 | long compat_ksys_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); | |
c84d0791 | 286 | long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr); |
41f4f0e2 DB |
287 | #endif /* CONFIG_COMPAT */ |
288 | ||
1da177e4 | 289 | #endif |