1 /* 2 * linux/ipc/namespace.c 3 * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc. 4 */ 5 6 #include <linux/ipc.h> 7 #include <linux/msg.h> 8 #include <linux/ipc_namespace.h> 9 #include <linux/rcupdate.h> 10 #include <linux/nsproxy.h> 11 #include <linux/slab.h> 12 13 #include "util.h" 14 15 static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) 16 { 17 struct ipc_namespace *ns; 18 19 ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); 20 if (ns == NULL) 21 return ERR_PTR(-ENOMEM); 22 23 sem_init_ns(ns); 24 msg_init_ns(ns); 25 shm_init_ns(ns); 26 27 kref_init(&ns->kref); 28 return ns; 29 } 30 31 struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) 32 { 33 struct ipc_namespace *new_ns; 34 35 BUG_ON(!ns); 36 get_ipc_ns(ns); 37 38 if (!(flags & CLONE_NEWIPC)) 39 return ns; 40 41 new_ns = clone_ipc_ns(ns); 42 43 put_ipc_ns(ns); 44 return new_ns; 45 } 46 47 /* 48 * free_ipcs - free all ipcs of one type 49 * @ns: the namespace to remove the ipcs from 50 * @ids: the table of ipcs to free 51 * @free: the function called to free each individual ipc 52 * 53 * Called for each kind of ipc when an ipc_namespace exits. 54 */ 55 void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, 56 void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)) 57 { 58 struct kern_ipc_perm *perm; 59 int next_id; 60 int total, in_use; 61 62 down_write(&ids->rw_mutex); 63 64 in_use = ids->in_use; 65 66 for (total = 0, next_id = 0; total < in_use; next_id++) { 67 perm = idr_find(&ids->ipcs_idr, next_id); 68 if (perm == NULL) 69 continue; 70 ipc_lock_by_ptr(perm); 71 free(ns, perm); 72 total++; 73 } 74 up_write(&ids->rw_mutex); 75 } 76 77 void free_ipc_ns(struct kref *kref) 78 { 79 struct ipc_namespace *ns; 80 81 ns = container_of(kref, struct ipc_namespace, kref); 82 sem_exit_ns(ns); 83 msg_exit_ns(ns); 84 shm_exit_ns(ns); 85 kfree(ns); 86 } 87