diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/ipc/namespace.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/ipc/namespace.c')
-rw-r--r-- | kernel/ipc/namespace.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/kernel/ipc/namespace.c b/kernel/ipc/namespace.c new file mode 100644 index 000000000..068caf18d --- /dev/null +++ b/kernel/ipc/namespace.c @@ -0,0 +1,175 @@ +/* + * linux/ipc/namespace.c + * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc. + */ + +#include <linux/ipc.h> +#include <linux/msg.h> +#include <linux/ipc_namespace.h> +#include <linux/rcupdate.h> +#include <linux/nsproxy.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/user_namespace.h> +#include <linux/proc_ns.h> + +#include "util.h" + +static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, + 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); + + err = ns_alloc_inum(&ns->ns); + if (err) { + kfree(ns); + return ERR_PTR(err); + } + ns->ns.ops = &ipcns_operations; + + atomic_set(&ns->count, 1); + err = mq_init_ns(ns); + if (err) { + ns_free_inum(&ns->ns); + kfree(ns); + return ERR_PTR(err); + } + atomic_inc(&nr_ipc_ns); + + sem_init_ns(ns); + msg_init_ns(ns); + shm_init_ns(ns); + + ns->user_ns = get_user_ns(user_ns); + + return ns; +} + +struct ipc_namespace *copy_ipcs(unsigned long flags, + struct user_namespace *user_ns, struct ipc_namespace *ns) +{ + if (!(flags & CLONE_NEWIPC)) + return get_ipc_ns(ns); + return create_ipc_ns(user_ns, ns); +} + +/* + * free_ipcs - free all ipcs of one type + * @ns: the namespace to remove the ipcs from + * @ids: the table of ipcs to free + * @free: the function called to free each individual ipc + * + * Called for each kind of ipc when an ipc_namespace exits. + */ +void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, + void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)) +{ + struct kern_ipc_perm *perm; + int next_id; + int total, in_use; + + down_write(&ids->rwsem); + + in_use = ids->in_use; + + for (total = 0, next_id = 0; total < in_use; next_id++) { + perm = idr_find(&ids->ipcs_idr, next_id); + if (perm == NULL) + continue; + rcu_read_lock(); + ipc_lock_object(perm); + free(ns, perm); + total++; + } + up_write(&ids->rwsem); +} + +static void free_ipc_ns(struct ipc_namespace *ns) +{ + sem_exit_ns(ns); + msg_exit_ns(ns); + shm_exit_ns(ns); + atomic_dec(&nr_ipc_ns); + + put_user_ns(ns->user_ns); + ns_free_inum(&ns->ns); + kfree(ns); +} + +/* + * put_ipc_ns - drop a reference to an ipc namespace. + * @ns: the namespace to put + * + * If this is the last task in the namespace exiting, and + * it is dropping the refcount to 0, then it can race with + * a task in another ipc namespace but in a mounts namespace + * which has this ipcns's mqueuefs mounted, doing some action + * with one of the mqueuefs files. That can raise the refcount. + * So dropping the refcount, and raising the refcount when + * accessing it through the VFS, are protected with mq_lock. + * + * (Clearly, a task raising the refcount on its own ipc_ns + * needn't take mq_lock since it can't race with the last task + * in the ipcns exiting). + */ +void put_ipc_ns(struct ipc_namespace *ns) +{ + if (atomic_dec_and_lock(&ns->count, &mq_lock)) { + mq_clear_sbinfo(ns); + spin_unlock(&mq_lock); + mq_put_mnt(ns); + free_ipc_ns(ns); + } +} + +static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) +{ + return container_of(ns, struct ipc_namespace, ns); +} + +static struct ns_common *ipcns_get(struct task_struct *task) +{ + struct ipc_namespace *ns = NULL; + struct nsproxy *nsproxy; + + task_lock(task); + nsproxy = task->nsproxy; + if (nsproxy) + ns = get_ipc_ns(nsproxy->ipc_ns); + task_unlock(task); + + return ns ? &ns->ns : NULL; +} + +static void ipcns_put(struct ns_common *ns) +{ + return put_ipc_ns(to_ipc_ns(ns)); +} + +static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new) +{ + struct ipc_namespace *ns = to_ipc_ns(new); + if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + return -EPERM; + + /* Ditch state from the old ipc namespace */ + exit_sem(current); + put_ipc_ns(nsproxy->ipc_ns); + nsproxy->ipc_ns = get_ipc_ns(ns); + return 0; +} + +const struct proc_ns_operations ipcns_operations = { + .name = "ipc", + .type = CLONE_NEWIPC, + .get = ipcns_get, + .put = ipcns_put, + .install = ipcns_install, +}; |