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