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