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 	gid_t pid_gid;
34 	int hide_pid;
35 };
36 
37 extern struct pid_namespace init_pid_ns;
38 
39 #ifdef CONFIG_PID_NS
get_pid_ns(struct pid_namespace * ns)40 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
41 {
42 	if (ns != &init_pid_ns)
43 		kref_get(&ns->kref);
44 	return ns;
45 }
46 
47 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
48 extern void free_pid_ns(struct kref *kref);
49 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
50 
put_pid_ns(struct pid_namespace * ns)51 static inline void put_pid_ns(struct pid_namespace *ns)
52 {
53 	if (ns != &init_pid_ns)
54 		kref_put(&ns->kref, free_pid_ns);
55 }
56 
57 #else /* !CONFIG_PID_NS */
58 #include <linux/err.h>
59 
get_pid_ns(struct pid_namespace * ns)60 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
61 {
62 	return ns;
63 }
64 
65 static inline struct pid_namespace *
copy_pid_ns(unsigned long flags,struct pid_namespace * ns)66 copy_pid_ns(unsigned long flags, struct pid_namespace *ns)
67 {
68 	if (flags & CLONE_NEWPID)
69 		ns = ERR_PTR(-EINVAL);
70 	return ns;
71 }
72 
put_pid_ns(struct pid_namespace * ns)73 static inline void put_pid_ns(struct pid_namespace *ns)
74 {
75 }
76 
77 
zap_pid_ns_processes(struct pid_namespace * ns)78 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
79 {
80 	BUG();
81 }
82 #endif /* CONFIG_PID_NS */
83 
84 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
85 void pidhash_init(void);
86 void pidmap_init(void);
87 
88 #endif /* _LINUX_PID_NS_H */
89