/* * linux/ipc/util.h * Copyright (C) 1999 Christoph Rohland * * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com> * namespaces support. 2006 OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */ #ifndef _IPC_UTIL_H #define _IPC_UTIL_H #define USHRT_MAX 0xffff #define SEQ_MULTIPLIER (IPCMNI) void sem_init (void); void msg_init (void); void shm_init (void); int sem_init_ns(struct ipc_namespace *ns); int msg_init_ns(struct ipc_namespace *ns); int shm_init_ns(struct ipc_namespace *ns); void sem_exit_ns(struct ipc_namespace *ns); void msg_exit_ns(struct ipc_namespace *ns); void shm_exit_ns(struct ipc_namespace *ns); struct ipc_id_ary { int size; struct kern_ipc_perm *p[0]; }; struct ipc_ids { int in_use; int max_id; unsigned short seq; unsigned short seq_max; struct mutex mutex; struct ipc_id_ary nullentry; struct ipc_id_ary* entries; }; struct seq_file; void ipc_init_ids(struct ipc_ids *ids, int size); #ifdef CONFIG_PROC_FS void __init ipc_init_proc_interface(const char *path, const char *header, int ids, int (*show)(struct seq_file *, void *)); #else #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) #endif #define IPC_SEM_IDS 0 #define IPC_MSG_IDS 1 #define IPC_SHM_IDS 2 /* must be called with ids->mutex acquired.*/ int ipc_findkey(struct ipc_ids* ids, key_t key); int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); /* must be called with both locks acquired. */ struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); int ipcperms (struct kern_ipc_perm *ipcp, short flg); /* for rare, potentially huge allocations. * both function can sleep */ void* ipc_alloc(int size); void ipc_free(void* ptr, int size); /* * For allocation that need to be freed by RCU. * Objects are reference counted, they start with reference count 1. * getref increases the refcount, the putref call that reduces the recount * to 0 schedules the rcu destruction. Caller must guarantee locking. */ void* ipc_rcu_alloc(int size); void ipc_rcu_getref(void *ptr); void ipc_rcu_putref(void *ptr); static inline void __ipc_fini_ids(struct ipc_ids *ids, struct ipc_id_ary *entries) { if (entries != &ids->nullentry) ipc_rcu_putref(entries); } static inline void ipc_fini_ids(struct ipc_ids *ids) { __ipc_fini_ids(ids, ids->entries); } struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id); struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); void ipc_unlock(struct kern_ipc_perm* perm); int ipc_buildid(struct ipc_ids* ids, int id, int seq); int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) /* On IA-64, we always use the "64-bit version" of the IPC structures. */ # define ipc_parse_version(cmd) IPC_64 #else int ipc_parse_version (int *cmd); #endif extern void free_msg(struct msg_msg *msg); extern struct msg_msg *load_msg(const void __user *src, int len); extern int store_msg(void __user *dest, struct msg_msg *msg, int len); #endif