ipc/namespace.c

   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 }