projects/linux·blob v2.6.21 · refs

119 lines · 3.3 KiB

1/*
2 * linux/ipc/util.h
3 * Copyright (C) 1999 Christoph Rohland
4 *
5 * ipc helper functions (c) 1999 Manfred Spraul <[email protected]>
6 * namespaces support. 2006 OpenVZ, SWsoft Inc.
7 * Pavel Emelianov <[email protected]>
8 */
9
10#ifndef _IPC_UTIL_H
11#define _IPC_UTIL_H
12
13#define USHRT_MAX 0xffff
14#define SEQ_MULTIPLIER (IPCMNI)
15
16void sem_init (void);
17void msg_init (void);
18void shm_init (void);
19
20int sem_init_ns(struct ipc_namespace *ns);
21int msg_init_ns(struct ipc_namespace *ns);
22int shm_init_ns(struct ipc_namespace *ns);
23
24void sem_exit_ns(struct ipc_namespace *ns);
25void msg_exit_ns(struct ipc_namespace *ns);
26void shm_exit_ns(struct ipc_namespace *ns);
27
28struct ipc_id_ary {
29 int size;
30 struct kern_ipc_perm *p[0];
31};
32
33struct ipc_ids {
34 int in_use;
35 int max_id;
36 unsigned short seq;
37 unsigned short seq_max;
38 struct mutex mutex;
39 struct ipc_id_ary nullentry;
40 struct ipc_id_ary* entries;
41};
42
43struct seq_file;
44#ifdef CONFIG_IPC_NS
45#define __ipc_init
46#else
47#define __ipc_init __init
48#endif
49void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size);
50#ifdef CONFIG_PROC_FS
51void __init ipc_init_proc_interface(const char *path, const char *header,
52 int ids, int (*show)(struct seq_file *, void *));
53#else
54#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
55#endif
56
57#define IPC_SEM_IDS 0
58#define IPC_MSG_IDS 1
59#define IPC_SHM_IDS 2
60
61/* must be called with ids->mutex acquired.*/
62int ipc_findkey(struct ipc_ids* ids, key_t key);
63int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
64
65/* must be called with both locks acquired. */
66struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
67
68int ipcperms (struct kern_ipc_perm *ipcp, short flg);
69
70/* for rare, potentially huge allocations.
71 * both function can sleep
72 */
73void* ipc_alloc(int size);
74void ipc_free(void* ptr, int size);
75
76/*
77 * For allocation that need to be freed by RCU.
78 * Objects are reference counted, they start with reference count 1.
79 * getref increases the refcount, the putref call that reduces the recount
80 * to 0 schedules the rcu destruction. Caller must guarantee locking.
81 */
82void* ipc_rcu_alloc(int size);
83void ipc_rcu_getref(void *ptr);
84void ipc_rcu_putref(void *ptr);
85
86static inline void __ipc_fini_ids(struct ipc_ids *ids,
87 struct ipc_id_ary *entries)
88{
89 if (entries != &ids->nullentry)
90 ipc_rcu_putref(entries);
91}
92
93static inline void ipc_fini_ids(struct ipc_ids *ids)
94{
95 __ipc_fini_ids(ids, ids->entries);
96}
97
98struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
99struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
100void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
101void ipc_unlock(struct kern_ipc_perm* perm);
102int ipc_buildid(struct ipc_ids* ids, int id, int seq);
103int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
104
105void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
106void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
107
108#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
109 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
110# define ipc_parse_version(cmd) IPC_64
111#else
112int ipc_parse_version (int *cmd);
113#endif
114
115extern void free_msg(struct msg_msg *msg);
116extern struct msg_msg *load_msg(const void __user *src, int len);
117extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
118
119#endif