1 /* 2 * linux/ipc/util.h 3 * Copyright (C) 1999 Christoph Rohland 4 * 5 * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com> 6 */ 7 8 #ifndef _IPC_UTIL_H 9 #define _IPC_UTIL_H 10 11 #define USHRT_MAX 0xffff 12 #define SEQ_MULTIPLIER (IPCMNI) 13 14 void sem_init (void); 15 void msg_init (void); 16 void shm_init (void); 17 18 struct ipc_id_ary { 19 int size; 20 struct kern_ipc_perm *p[0]; 21 }; 22 23 struct ipc_ids { 24 int in_use; 25 int max_id; 26 unsigned short seq; 27 unsigned short seq_max; 28 struct semaphore sem; 29 struct ipc_id_ary nullentry; 30 struct ipc_id_ary* entries; 31 }; 32 33 void __init ipc_init_ids(struct ipc_ids* ids, int size); 34 35 /* must be called with ids->sem acquired.*/ 36 int ipc_findkey(struct ipc_ids* ids, key_t key); 37 int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); 38 39 /* must be called with both locks acquired. */ 40 struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); 41 42 int ipcperms (struct kern_ipc_perm *ipcp, short flg); 43 44 /* for rare, potentially huge allocations. 45 * both function can sleep 46 */ 47 void* ipc_alloc(int size); 48 void ipc_free(void* ptr, int size); 49 50 /* 51 * For allocation that need to be freed by RCU. 52 * Objects are reference counted, they start with reference count 1. 53 * getref increases the refcount, the putref call that reduces the recount 54 * to 0 schedules the rcu destruction. Caller must guarantee locking. 55 */ 56 void* ipc_rcu_alloc(int size); 57 void ipc_rcu_getref(void *ptr); 58 void ipc_rcu_putref(void *ptr); 59 60 struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id); 61 struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); 62 void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); 63 void ipc_unlock(struct kern_ipc_perm* perm); 64 int ipc_buildid(struct ipc_ids* ids, int id, int seq); 65 int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); 66 67 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); 68 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); 69 70 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) 71 /* On IA-64, we always use the "64-bit version" of the IPC structures. */ 72 # define ipc_parse_version(cmd) IPC_64 73 #else 74 int ipc_parse_version (int *cmd); 75 #endif 76 77 extern void free_msg(struct msg_msg *msg); 78 extern struct msg_msg *load_msg(const void __user *src, int len); 79 extern int store_msg(void __user *dest, struct msg_msg *msg, int len); 80 81 #endif 82