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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/ipc/util.h
3 * Copyright (C) 1999 Christoph Rohland
4 *
5 * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
6 * namespaces support. 2006 OpenVZ, SWsoft Inc.
7 * Pavel Emelianov <xemul@openvz.org>
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
45void ipc_init_ids(struct ipc_ids *ids, int size);
46#ifdef CONFIG_PROC_FS
47void __init ipc_init_proc_interface(const char *path, const char *header,
48 int ids, int (*show)(struct seq_file *, void *));
49#else
50#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
51#endif
52
53#define IPC_SEM_IDS 0
54#define IPC_MSG_IDS 1
55#define IPC_SHM_IDS 2
56
57/* must be called with ids->mutex acquired.*/
58int ipc_findkey(struct ipc_ids* ids, key_t key);
59int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
60
61/* must be called with both locks acquired. */
62struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
63
64int ipcperms (struct kern_ipc_perm *ipcp, short flg);
65
66/* for rare, potentially huge allocations.
67 * both function can sleep
68 */
69void* ipc_alloc(int size);
70void ipc_free(void* ptr, int size);
71
72/*
73 * For allocation that need to be freed by RCU.
74 * Objects are reference counted, they start with reference count 1.
75 * getref increases the refcount, the putref call that reduces the recount
76 * to 0 schedules the rcu destruction. Caller must guarantee locking.
77 */
78void* ipc_rcu_alloc(int size);
79void ipc_rcu_getref(void *ptr);
80void ipc_rcu_putref(void *ptr);
81
82static inline void __ipc_fini_ids(struct ipc_ids *ids,
83 struct ipc_id_ary *entries)
84{
85 if (entries != &ids->nullentry)
86 ipc_rcu_putref(entries);
87}
88
89static inline void ipc_fini_ids(struct ipc_ids *ids)
90{
91 __ipc_fini_ids(ids, ids->entries);
92}
93
94struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
95struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
96void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
97void ipc_unlock(struct kern_ipc_perm* perm);
98int ipc_buildid(struct ipc_ids* ids, int id, int seq);
99int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
100
101void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
102void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
103
104#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
105 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
106# define ipc_parse_version(cmd) IPC_64
107#else
108int ipc_parse_version (int *cmd);
109#endif
110
111extern void free_msg(struct msg_msg *msg);
112extern struct msg_msg *load_msg(const void __user *src, int len);
113extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
114
115#endif