#include <linux/module.h>
#include <linux/uts.h>
#include <linux/utsname.h>
-#include <linux/version.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
+
+static struct uts_namespace *create_uts_ns(void)
+{
+ struct uts_namespace *uts_ns;
+
+ uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
+ if (uts_ns)
+ kref_init(&uts_ns->kref);
+ return uts_ns;
+}
+
+/*
+ * Clone a new ns copying an original utsname, setting refcount to 1
+ * @old_ns: namespace to clone
+ * Return NULL on error (failure to kmalloc), new ns otherwise
+ */
+static struct uts_namespace *clone_uts_ns(struct task_struct *tsk,
+ struct uts_namespace *old_ns)
+{
+ struct uts_namespace *ns;
+
+ ns = create_uts_ns();
+ if (!ns)
+ return ERR_PTR(-ENOMEM);
+
+ down_read(&uts_sem);
+ memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+ ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns);
+ up_read(&uts_sem);
+ return ns;
+}
/*
* Copy task tsk's utsname namespace, or clone it if flags
* utsname of this process won't be seen by parent, and vice
* versa.
*/
-int copy_utsname(int flags, struct task_struct *tsk)
+struct uts_namespace *copy_utsname(unsigned long flags,
+ struct task_struct *tsk)
{
struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
- int err = 0;
-
- if (!old_ns)
- return 0;
+ struct uts_namespace *new_ns;
+ BUG_ON(!old_ns);
get_uts_ns(old_ns);
- return err;
+ if (!(flags & CLONE_NEWUTS))
+ return old_ns;
+
+ new_ns = clone_uts_ns(tsk, old_ns);
+
+ put_uts_ns(old_ns);
+ return new_ns;
}
void free_uts_ns(struct kref *kref)
struct uts_namespace *ns;
ns = container_of(kref, struct uts_namespace, kref);
+ put_user_ns(ns->user_ns);
kfree(ns);
}
+
+static void *utsns_get(struct task_struct *task)
+{
+ struct uts_namespace *ns = NULL;
+ struct nsproxy *nsproxy;
+
+ rcu_read_lock();
+ nsproxy = task_nsproxy(task);
+ if (nsproxy) {
+ ns = nsproxy->uts_ns;
+ get_uts_ns(ns);
+ }
+ rcu_read_unlock();
+
+ return ns;
+}
+
+static void utsns_put(void *ns)
+{
+ put_uts_ns(ns);
+}
+
+static int utsns_install(struct nsproxy *nsproxy, void *ns)
+{
+ get_uts_ns(ns);
+ put_uts_ns(nsproxy->uts_ns);
+ nsproxy->uts_ns = ns;
+ return 0;
+}
+
+const struct proc_ns_operations utsns_operations = {
+ .name = "uts",
+ .type = CLONE_NEWUTS,
+ .get = utsns_get,
+ .put = utsns_put,
+ .install = utsns_install,
+};
+