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/mm.h>
   6 #include <linux/threads.h>
   7 #include <linux/nsproxy.h>
   8 #include <linux/kref.h>
   9
  10 struct pidmap {
  11        atomic_t nr_free;
  12        void *page;
  13 };
  14
  15 #define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
  16
  17 struct bsd_acct_struct;
  18
  19 struct pid_namespace {
  20         struct kref kref;
  21         struct pidmap pidmap[PIDMAP_ENTRIES];
  22         int last_pid;
  23         struct task_struct *child_reaper;
  24         struct kmem_cache *pid_cachep;
  25         unsigned int level;
  26         struct pid_namespace *parent;
  27 #ifdef CONFIG_PROC_FS
  28         struct vfsmount *proc_mnt;
  29 #endif
  30 #ifdef CONFIG_BSD_PROCESS_ACCT
  31         struct bsd_acct_struct *bacct;
  32 #endif
  33 };
  34
  35 extern struct pid_namespace init_pid_ns;
  36
  37 #ifdef CONFIG_PID_NS
  38 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  39 {
  40         if (ns != &init_pid_ns)
  41                 kref_get(&ns->kref);
  42         return ns;
  43 }
  44
  45 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
  46 extern void free_pid_ns(struct kref *kref);
  47 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
  48
  49 static inline void put_pid_ns(struct pid_namespace *ns)
  50 {
  51         if (ns != &init_pid_ns)
  52                 kref_put(&ns->kref, free_pid_ns);
  53 }
  54
  55 #else /* !CONFIG_PID_NS */
  56 #include <linux/err.h>
  57
  58 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  59 {
  60         return ns;
  61 }
  62
  63 static inline struct pid_namespace *
  64 copy_pid_ns(unsigned long flags, struct pid_namespace *ns)
  65 {
  66         if (flags & CLONE_NEWPID)
  67                 ns = ERR_PTR(-EINVAL);
  68         return ns;
  69 }
  70
  71 static inline void put_pid_ns(struct pid_namespace *ns)
  72 {
  73 }
  74
  75
  76 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
  77 {
  78         BUG();
  79 }
  80 #endif /* CONFIG_PID_NS */
  81
  82 static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
  83 {
  84         return tsk->nsproxy->pid_ns;
  85 }
  86
  87 void pidhash_init(void);
  88 void pidmap_init(void);
  89
  90 #endif /* _LINUX_PID_NS_H */