include/linux/sched/user.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_SCHED_USER_H
   3 #define _LINUX_SCHED_USER_H
   4
   5 #include <linux/uidgid.h>
   6 #include <linux/atomic.h>
   7
   8 struct key;
   9
  10 /*
  11  * Some day this will be a full-fledged user tracking system..
  12  */
  13 struct user_struct {
  14         atomic_t __count;       /* reference count */
  15         atomic_t processes;     /* How many processes does this user have? */
  16         atomic_t sigpending;    /* How many pending signals does this user have? */
  17 #ifdef CONFIG_FANOTIFY
  18         atomic_t fanotify_listeners;
  19 #endif
  20 #ifdef CONFIG_EPOLL
  21         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
  22 #endif
  23 #ifdef CONFIG_POSIX_MQUEUE
  24         /* protected by mq_lock */
  25         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
  26 #endif
  27         unsigned long locked_shm; /* How many pages of mlocked shm ? */
  28         unsigned long unix_inflight;    /* How many files in flight in unix sockets */
  29         atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
  30
  31 #ifdef CONFIG_KEYS
  32         struct key *uid_keyring;        /* UID specific keyring */
  33         struct key *session_keyring;    /* UID's default session keyring */
  34 #endif
  35
  36         /* Hash table maintenance information */
  37         struct hlist_node uidhash_node;
  38         kuid_t uid;
  39
  40 #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \
  41     defined(CONFIG_NET)
  42         atomic_long_t locked_vm;
  43 #endif
  44 };
  45
  46 extern int uids_sysfs_init(void);
  47
  48 extern struct user_struct *find_user(kuid_t);
  49
  50 extern struct user_struct root_user;
  51 #define INIT_USER (&root_user)
  52
  53
  54 /* per-UID process charging. */
  55 extern struct user_struct * alloc_uid(kuid_t);
  56 static inline struct user_struct *get_uid(struct user_struct *u)
  57 {
  58         atomic_inc(&u->__count);
  59         return u;
  60 }
  61 extern void free_uid(struct user_struct *);
  62
  63 #endif /* _LINUX_SCHED_USER_H */