void free_ipc_ns(struct kref *kref) { struct ipc_namespace *ns; ns = container_of(kref, struct ipc_namespace, kref); /* * Unregistering the hotplug notifier at the beginning guarantees * that the ipc namespace won't be freed while we are inside the * callback routine. Since the blocking_notifier_chain_XXX routines * hold a rw lock on the notifier list, unregister_ipcns_notifier() * won't take the rw lock before blocking_notifier_call_chain() has * released the rd lock. */ unregister_ipcns_notifier(ns); sem_exit_ns(ns); msg_exit_ns(ns); shm_exit_ns(ns); kfree(ns); atomic_dec(&nr_ipc_ns); /* * Do the ipcns removal notification after decrementing nr_ipc_ns in * order to have a correct value when recomputing msgmni. */ ipcns_notify(IPCNS_REMOVED); }
static struct ipc_namespace *create_ipc_ns(struct task_struct *tsk, struct ipc_namespace *old_ns) { struct ipc_namespace *ns; int err; ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); if (ns == NULL) return ERR_PTR(-ENOMEM); atomic_set(&ns->count, 1); err = mq_init_ns(ns); if (err) { kfree(ns); return ERR_PTR(err); } atomic_inc(&nr_ipc_ns); sem_init_ns(ns); msg_init_ns(ns); shm_init_ns(ns); /* * msgmni has already been computed for the new ipc ns. * Thus, do the ipcns creation notification before registering that * new ipcns in the chain. */ ipcns_notify(IPCNS_CREATED); register_ipcns_notifier(ns); ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns); return ns; }
static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) { struct ipc_namespace *ns; ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); if (ns == NULL) return ERR_PTR(-ENOMEM); atomic_inc(&nr_ipc_ns); sem_init_ns(ns); msg_init_ns(ns); shm_init_ns(ns); /* * msgmni has already been computed for the new ipc ns. * Thus, do the ipcns creation notification before registering that * new ipcns in the chain. */ ipcns_notify(IPCNS_CREATED); register_ipcns_notifier(ns); kref_init(&ns->kref); return ns; }
static void ipc_memory_notifier(struct work_struct *work) { ipcns_notify(IPCNS_MEMCHANGED); }