Merge tag 'livepatching-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-block.git] / ipc / util.h
CommitLineData
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 <manfred@colorfullife.com>
73ea4130
KK
7 * namespaces support. 2006 OpenVZ, SWsoft Inc.
8 * Pavel Emelianov <xemul@openvz.org>
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
35extern int ipc_mni;
36extern int ipc_mni_shift;
99db46ea 37extern 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
50void sem_init(void);
51void msg_init(void);
239521f3 52void shm_init(void);
1da177e4 53
ae5e1b22 54struct ipc_namespace;
03f1fc09 55struct pid_namespace;
ae5e1b22 56
614b84cf 57#ifdef CONFIG_POSIX_MQUEUE
7eafd7c7 58extern void mq_clear_sbinfo(struct ipc_namespace *ns);
614b84cf 59#else
7eafd7c7 60static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
614b84cf
SH
61#endif
62
63#ifdef CONFIG_SYSVIPC
eae04d25 64void sem_init_ns(struct ipc_namespace *ns);
72d1e611 65int msg_init_ns(struct ipc_namespace *ns);
eae04d25 66void shm_init_ns(struct ipc_namespace *ns);
73ea4130
KK
67
68void sem_exit_ns(struct ipc_namespace *ns);
69void msg_exit_ns(struct ipc_namespace *ns);
70void shm_exit_ns(struct ipc_namespace *ns);
614b84cf 71#else
eae04d25 72static inline void sem_init_ns(struct ipc_namespace *ns) { }
72d1e611 73static inline int msg_init_ns(struct ipc_namespace *ns) { return 0; }
eae04d25 74static inline void shm_init_ns(struct ipc_namespace *ns) { }
614b84cf
SH
75
76static inline void sem_exit_ns(struct ipc_namespace *ns) { }
77static inline void msg_exit_ns(struct ipc_namespace *ns) { }
78static 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 */
85struct 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 */
104struct 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 110struct seq_file;
ed2ddbf8 111struct ipc_ids;
7d69a1f4 112
eae04d25 113void ipc_init_ids(struct ipc_ids *ids);
ae781774
MW
114#ifdef CONFIG_PROC_FS
115void __init ipc_init_proc_interface(const char *path, const char *header,
73ea4130 116 int ids, int (*show)(struct seq_file *, void *));
03f1fc09 117struct 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 131int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
3e148c79 132
1da177e4 133/* must be called with both locks acquired. */
7ca7e564 134void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
1da177e4 135
0cfb6aee
GK
136/* must be called with both locks acquired. */
137void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *);
138
f4566f04 139/* must be called with ipcp locked */
b0e77598 140int 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 151static 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 171bool ipc_rcu_getref(struct kern_ipc_perm *ptr);
dba4cdd3
MS
172void ipc_rcu_putref(struct kern_ipc_perm *ptr,
173 void (*func)(struct rcu_head *head));
1da177e4 174
55b7ae50 175struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
1da177e4
LT
176
177void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
178void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
1efdb69b 179int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
4241c1a3 180struct 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
184static 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 194int ipc_parse_version(int *cmd);
1da177e4
LT
195#endif
196
197extern void free_msg(struct msg_msg *msg);
4e9b45a1 198extern struct msg_msg *load_msg(const void __user *src, size_t len);
4a674f34 199extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
4e9b45a1 200extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
7748dbfa 201
27c331a1 202static 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 207static inline void ipc_lock_object(struct kern_ipc_perm *perm)
023a5355 208{
023a5355
ND
209 spin_lock(&perm->lock);
210}
211
1ca7003a 212static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
023a5355
ND
213{
214 spin_unlock(&perm->lock);
023a5355
ND
215}
216
1ca7003a 217static 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
222static 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 */
236static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
237{
72a8ff2f 238 return !perm->deleted;
0f3d2b01
RA
239}
240
4d2bff5e 241struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
b2d75cdd 242int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
eb66ec44 243 const struct ipc_ops *ops, struct ipc_params *params);
665c7741
AD
244void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
245 void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
553f770e 246
8c81ddd2
WL
247static 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>
258struct 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
268void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *);
269void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *);
270int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *);
271int get_compat_ipc64_perm(struct ipc64_perm *,
272 struct compat_ipc64_perm __user *);
273
553f770e
AV
274static 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
281long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg);
282long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr);
078faac9
DB
283long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
284 compat_long_t msgtyp, int msgflg);
31c213f2
DB
285long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
286 compat_ssize_t msgsz, int msgflg);
275f2214 287long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr);
fb377eb8
AB
288
289#endif
41f4f0e2 290
1da177e4 291#endif