utsname.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10

    1 /*
    2  *  Copyright (C) 2004 IBM Corporation
    3  *
    4  *  Author: Serge Hallyn <serue@us.ibm.com>
    5  *
    6  *  This program is free software; you can redistribute it and/or
    7  *  modify it under the terms of the GNU General Public License as
    8  *  published by the Free Software Foundation, version 2 of the
    9  *  License.
   10  */
   11 
   12 #include <linux/export.h>
   13 #include <linux/uts.h>
   14 #include <linux/utsname.h>
   15 #include <linux/err.h>
   16 #include <linux/slab.h>
   17 #include <linux/user_namespace.h>
   18 #include <linux/proc_fs.h>
   19 
   20 static struct uts_namespace *create_uts_ns(void)
   21 {
   22         struct uts_namespace *uts_ns;
   23 
   24         uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
   25         if (uts_ns)
   26                 kref_init(&uts_ns->kref);
   27         return uts_ns;
   28 }
   29 
   30 /*
   31  * Clone a new ns copying an original utsname, setting refcount to 1
   32  * @old_ns: namespace to clone
   33  * Return NULL on error (failure to kmalloc), new ns otherwise
   34  */
   35 static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
   36                                           struct uts_namespace *old_ns)
   37 {
   38         struct uts_namespace *ns;
   39         int err;
   40 
   41         ns = create_uts_ns();
   42         if (!ns)
   43                 return ERR_PTR(-ENOMEM);
   44 
   45         err = proc_alloc_inum(&ns->proc_inum);
   46         if (err) {
   47                 kfree(ns);
   48                 return ERR_PTR(err);
   49         }
   50 
   51         down_read(&uts_sem);
   52         memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
   53         ns->user_ns = get_user_ns(user_ns);
   54         up_read(&uts_sem);
   55         return ns;
   56 }
   57 
   58 /*
   59  * Copy task tsk's utsname namespace, or clone it if flags
   60  * specifies CLONE_NEWUTS.  In latter case, changes to the
   61  * utsname of this process won't be seen by parent, and vice
   62  * versa.
   63  */
   64 struct uts_namespace *copy_utsname(unsigned long flags,
   65         struct user_namespace *user_ns, struct uts_namespace *old_ns)
   66 {
   67         struct uts_namespace *new_ns;
   68 
   69         BUG_ON(!old_ns);
   70         get_uts_ns(old_ns);
   71 
   72         if (!(flags & CLONE_NEWUTS))
   73                 return old_ns;
   74 
   75         new_ns = clone_uts_ns(user_ns, old_ns);
   76 
   77         put_uts_ns(old_ns);
   78         return new_ns;
   79 }
   80 
   81 void free_uts_ns(struct kref *kref)
   82 {
   83         struct uts_namespace *ns;
   84 
   85         ns = container_of(kref, struct uts_namespace, kref);
   86         put_user_ns(ns->user_ns);
   87         proc_free_inum(ns->proc_inum);
   88         kfree(ns);
   89 }
   90 
   91 static void *utsns_get(struct task_struct *task)
   92 {
   93         struct uts_namespace *ns = NULL;
   94         struct nsproxy *nsproxy;
   95 
   96         rcu_read_lock();
   97         nsproxy = task_nsproxy(task);
   98         if (nsproxy) {
   99                 ns = nsproxy->uts_ns;
  100                 get_uts_ns(ns);
  101         }
  102         rcu_read_unlock();
  103 
  104         return ns;
  105 }
  106 
  107 static void utsns_put(void *ns)
  108 {
  109         put_uts_ns(ns);
  110 }
  111 
  112 static int utsns_install(struct nsproxy *nsproxy, void *new)
  113 {
  114         struct uts_namespace *ns = new;
  115 
  116         if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
  117             !nsown_capable(CAP_SYS_ADMIN))
  118                 return -EPERM;
  119 
  120         get_uts_ns(ns);
  121         put_uts_ns(nsproxy->uts_ns);
  122         nsproxy->uts_ns = ns;
  123         return 0;
  124 }
  125 
  126 static unsigned int utsns_inum(void *vp)
  127 {
  128         struct uts_namespace *ns = vp;
  129 
  130         return ns->proc_inum;
  131 }
  132 
  133 const struct proc_ns_operations utsns_operations = {
  134         .name           = "uts",
  135         .type           = CLONE_NEWUTS,
  136         .get            = utsns_get,
  137         .put            = utsns_put,
  138         .install        = utsns_install,
  139         .inum           = utsns_inum,
  140 };

Cache object: dc2df199fc2eeb4301f7f4b78eaa7836

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.

FreeBSD/Linux Kernel Cross Reference sys/kernel/utsname.c

FreeBSD/Linux Kernel Cross Reference
sys/kernel/utsname.c