include/linux/utsname.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_UTSNAME_H
   3 #define _LINUX_UTSNAME_H
   4
   5
   6 #include <linux/sched.h>
   7 #include <linux/kref.h>
   8 #include <linux/nsproxy.h>
   9 #include <linux/ns_common.h>
  10 #include <linux/err.h>
  11 #include <uapi/linux/utsname.h>
  12
  13 enum uts_proc {
  14         UTS_PROC_OSTYPE,
  15         UTS_PROC_OSRELEASE,
  16         UTS_PROC_VERSION,
  17         UTS_PROC_HOSTNAME,
  18         UTS_PROC_DOMAINNAME,
  19 };
  20
  21 struct user_namespace;
  22 extern struct user_namespace init_user_ns;
  23
  24 struct uts_namespace {
  25         struct kref kref;
  26         struct new_utsname name;
  27         struct user_namespace *user_ns;
  28         struct ucounts *ucounts;
  29         struct ns_common ns;
  30 } __randomize_layout;
  31 extern struct uts_namespace init_uts_ns;
  32
  33 #ifdef CONFIG_UTS_NS
  34 static inline void get_uts_ns(struct uts_namespace *ns)
  35 {
  36         kref_get(&ns->kref);
  37 }
  38
  39 extern struct uts_namespace *copy_utsname(unsigned long flags,
  40         struct user_namespace *user_ns, struct uts_namespace *old_ns);
  41 extern void free_uts_ns(struct kref *kref);
  42
  43 static inline void put_uts_ns(struct uts_namespace *ns)
  44 {
  45         kref_put(&ns->kref, free_uts_ns);
  46 }
  47 #else
  48 static inline void get_uts_ns(struct uts_namespace *ns)
  49 {
  50 }
  51
  52 static inline void put_uts_ns(struct uts_namespace *ns)
  53 {
  54 }
  55
  56 static inline struct uts_namespace *copy_utsname(unsigned long flags,
  57         struct user_namespace *user_ns, struct uts_namespace *old_ns)
  58 {
  59         if (flags & CLONE_NEWUTS)
  60                 return ERR_PTR(-EINVAL);
  61
  62         return old_ns;
  63 }
  64 #endif
  65
  66 #ifdef CONFIG_PROC_SYSCTL
  67 extern void uts_proc_notify(enum uts_proc proc);
  68 #else
  69 static inline void uts_proc_notify(enum uts_proc proc)
  70 {
  71 }
  72 #endif
  73
  74 static inline struct new_utsname *utsname(void)
  75 {
  76         return &current->nsproxy->uts_ns->name;
  77 }
  78
  79 static inline struct new_utsname *init_utsname(void)
  80 {
  81         return &init_uts_ns.name;
  82 }
  83
  84 extern struct rw_semaphore uts_sem;
  85
  86 #endif /* _LINUX_UTSNAME_H */