include/linux/pid_namespace.h

   1 #ifndef _LINUX_PID_NS_H
   2 #define _LINUX_PID_NS_H
   3
   4 #include <linux/sched.h>
   5 #include <linux/bug.h>
   6 #include <linux/mm.h>
   7 #include <linux/workqueue.h>
   8 #include <linux/threads.h>
   9 #include <linux/nsproxy.h>
  10 #include <linux/kref.h>
  11 #include <linux/ns_common.h>
  12
  13 struct pidmap {
  14        atomic_t nr_free;
  15        void *page;
  16 };
  17
  18 #define BITS_PER_PAGE           (PAGE_SIZE * 8)
  19 #define BITS_PER_PAGE_MASK      (BITS_PER_PAGE-1)
  20 #define PIDMAP_ENTRIES          ((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
  21
  22 struct fs_pin;
  23
  24 enum { /* definitions for pid_namespace's hide_pid field */
  25         HIDEPID_OFF       = 0,
  26         HIDEPID_NO_ACCESS = 1,
  27         HIDEPID_INVISIBLE = 2,
  28 };
  29
  30 struct pid_namespace {
  31         struct kref kref;
  32         struct pidmap pidmap[PIDMAP_ENTRIES];
  33         struct rcu_head rcu;
  34         int last_pid;
  35         unsigned int nr_hashed;
  36         struct task_struct *child_reaper;
  37         struct kmem_cache *pid_cachep;
  38         unsigned int level;
  39         struct pid_namespace *parent;
  40 #ifdef CONFIG_PROC_FS
  41         struct vfsmount *proc_mnt;
  42         struct dentry *proc_self;
  43         struct dentry *proc_thread_self;
  44 #endif
  45 #ifdef CONFIG_BSD_PROCESS_ACCT
  46         struct fs_pin *bacct;
  47 #endif
  48         struct user_namespace *user_ns;
  49         struct ucounts *ucounts;
  50         struct work_struct proc_work;
  51         kgid_t pid_gid;
  52         int hide_pid;
  53         int reboot;     /* group exit code if this pidns was rebooted */
  54         struct ns_common ns;
  55 };
  56
  57 extern struct pid_namespace init_pid_ns;
  58
  59 #define PIDNS_HASH_ADDING (1U << 31)
  60
  61 #ifdef CONFIG_PID_NS
  62 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  63 {
  64         if (ns != &init_pid_ns)
  65                 kref_get(&ns->kref);
  66         return ns;
  67 }
  68
  69 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
  70         struct user_namespace *user_ns, struct pid_namespace *ns);
  71 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
  72 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
  73 extern void put_pid_ns(struct pid_namespace *ns);
  74
  75 #else /* !CONFIG_PID_NS */
  76 #include <linux/err.h>
  77
  78 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  79 {
  80         return ns;
  81 }
  82
  83 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
  84         struct user_namespace *user_ns, struct pid_namespace *ns)
  85 {
  86         if (flags & CLONE_NEWPID)
  87                 ns = ERR_PTR(-EINVAL);
  88         return ns;
  89 }
  90
  91 static inline void put_pid_ns(struct pid_namespace *ns)
  92 {
  93 }
  94
  95 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
  96 {
  97         BUG();
  98 }
  99
 100 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
 101 {
 102         return 0;
 103 }
 104 #endif /* CONFIG_PID_NS */
 105
 106 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
 107 void pidhash_init(void);
 108 void pidmap_init(void);
 109
 110 #endif /* _LINUX_PID_NS_H */