3 * Copyright (C) 1999 Christoph Rohland
5 * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
6 * namespaces support. 2006 OpenVZ, SWsoft Inc.
7 * Pavel Emelianov <xemul@openvz.org>
13 #include <linux/err.h>
15 #define SEQ_MULTIPLIER (IPCMNI)
23 void sem_init_ns(struct ipc_namespace
*ns
);
24 void msg_init_ns(struct ipc_namespace
*ns
);
25 void shm_init_ns(struct ipc_namespace
*ns
);
27 void sem_exit_ns(struct ipc_namespace
*ns
);
28 void msg_exit_ns(struct ipc_namespace
*ns
);
29 void shm_exit_ns(struct ipc_namespace
*ns
);
32 * Structure that holds the parameters needed by the ipc operations
39 size_t size
; /* for shared memories */
40 int nsems
; /* for semaphores */
41 } u
; /* holds the getnew() specific param */
45 * Structure that holds some ipc operations. This structure is used to unify
46 * the calls to sys_msgget(), sys_semget(), sys_shmget()
47 * . routine to call to create a new ipc object. Can be one of newque,
49 * . routine to call to check permissions for a new ipc object.
50 * Can be one of security_msg_associate, security_sem_associate,
51 * security_shm_associate
52 * . routine to call for an extra check if needed
55 int (*getnew
) (struct ipc_namespace
*, struct ipc_params
*);
56 int (*associate
) (struct kern_ipc_perm
*, int);
57 int (*more_checks
) (struct kern_ipc_perm
*, struct ipc_params
*);
63 void ipc_init_ids(struct ipc_ids
*);
65 void __init
ipc_init_proc_interface(const char *path
, const char *header
,
66 int ids
, int (*show
)(struct seq_file
*, void *));
68 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
75 #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
77 /* must be called with ids->rw_mutex acquired for writing */
78 int ipc_addid(struct ipc_ids
*, struct kern_ipc_perm
*, int);
80 /* must be called with ids->rw_mutex acquired for reading */
81 int ipc_get_maxid(struct ipc_ids
*);
83 /* must be called with both locks acquired. */
84 void ipc_rmid(struct ipc_ids
*, struct kern_ipc_perm
*);
86 /* must be called with ipcp locked */
87 int ipcperms(struct kern_ipc_perm
*ipcp
, short flg
);
89 /* for rare, potentially huge allocations.
90 * both function can sleep
92 void* ipc_alloc(int size
);
93 void ipc_free(void* ptr
, int size
);
96 * For allocation that need to be freed by RCU.
97 * Objects are reference counted, they start with reference count 1.
98 * getref increases the refcount, the putref call that reduces the recount
99 * to 0 schedules the rcu destruction. Caller must guarantee locking.
101 void* ipc_rcu_alloc(int size
);
102 void ipc_rcu_getref(void *ptr
);
103 void ipc_rcu_putref(void *ptr
);
106 * ipc_lock_down: called with rw_mutex held
107 * ipc_lock: called without that lock held
109 struct kern_ipc_perm
*ipc_lock_down(struct ipc_ids
*, int);
110 struct kern_ipc_perm
*ipc_lock(struct ipc_ids
*, int);
112 void kernel_to_ipc64_perm(struct kern_ipc_perm
*in
, struct ipc64_perm
*out
);
113 void ipc64_perm_to_ipc_perm(struct ipc64_perm
*in
, struct ipc_perm
*out
);
114 void ipc_update_perm(struct ipc64_perm
*in
, struct kern_ipc_perm
*out
);
115 struct kern_ipc_perm
*ipcctl_pre_down(struct ipc_ids
*ids
, int id
, int cmd
,
116 struct ipc64_perm
*perm
, int extra_perm
);
118 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
119 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
120 # define ipc_parse_version(cmd) IPC_64
122 int ipc_parse_version (int *cmd
);
125 extern void free_msg(struct msg_msg
*msg
);
126 extern struct msg_msg
*load_msg(const void __user
*src
, int len
);
127 extern int store_msg(void __user
*dest
, struct msg_msg
*msg
, int len
);
129 extern void recompute_msgmni(struct ipc_namespace
*);
131 static inline int ipc_buildid(int id
, int seq
)
133 return SEQ_MULTIPLIER
* seq
+ id
;
137 * Must be called with ipcp locked
139 static inline int ipc_checkid(struct kern_ipc_perm
*ipcp
, int uid
)
141 if (uid
/ SEQ_MULTIPLIER
!= ipcp
->seq
)
146 static inline void ipc_lock_by_ptr(struct kern_ipc_perm
*perm
)
149 spin_lock(&perm
->lock
);
152 static inline void ipc_unlock(struct kern_ipc_perm
*perm
)
154 spin_unlock(&perm
->lock
);
158 struct kern_ipc_perm
*ipc_lock_check_down(struct ipc_ids
*ids
, int id
);
159 struct kern_ipc_perm
*ipc_lock_check(struct ipc_ids
*ids
, int id
);
160 int ipcget(struct ipc_namespace
*ns
, struct ipc_ids
*ids
,
161 struct ipc_ops
*ops
, struct ipc_params
*params
);