xref: /linux-6.15/include/linux/pid_namespace.h (revision e8fa600e)
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 	kgid_t pid_gid;
35 	int hide_pid;
36 	int reboot;	/* group exit code if this pidns was rebooted */
37 };
38 
39 extern struct pid_namespace init_pid_ns;
40 
41 #ifdef CONFIG_PID_NS
42 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
43 {
44 	if (ns != &init_pid_ns)
45 		kref_get(&ns->kref);
46 	return ns;
47 }
48 
49 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
50 extern void free_pid_ns(struct kref *kref);
51 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
52 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
53 
54 static inline void put_pid_ns(struct pid_namespace *ns)
55 {
56 	if (ns != &init_pid_ns)
57 		kref_put(&ns->kref, free_pid_ns);
58 }
59 
60 #else /* !CONFIG_PID_NS */
61 #include <linux/err.h>
62 
63 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
64 {
65 	return ns;
66 }
67 
68 static inline struct pid_namespace *
69 copy_pid_ns(unsigned long flags, struct pid_namespace *ns)
70 {
71 	if (flags & CLONE_NEWPID)
72 		ns = ERR_PTR(-EINVAL);
73 	return ns;
74 }
75 
76 static inline void put_pid_ns(struct pid_namespace *ns)
77 {
78 }
79 
80 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
81 {
82 	BUG();
83 }
84 
85 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
86 {
87 	return 0;
88 }
89 #endif /* CONFIG_PID_NS */
90 
91 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
92 void pidhash_init(void);
93 void pidmap_init(void);
94 
95 #endif /* _LINUX_PID_NS_H */
96