xref: /linux-6.15/include/linux/pid_namespace.h (revision b889fcf6)
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 	int nr_hashed;
25 	struct task_struct *child_reaper;
26 	struct kmem_cache *pid_cachep;
27 	unsigned int level;
28 	struct pid_namespace *parent;
29 #ifdef CONFIG_PROC_FS
30 	struct vfsmount *proc_mnt;
31 #endif
32 #ifdef CONFIG_BSD_PROCESS_ACCT
33 	struct bsd_acct_struct *bacct;
34 #endif
35 	struct user_namespace *user_ns;
36 	struct work_struct proc_work;
37 	kgid_t pid_gid;
38 	int hide_pid;
39 	int reboot;	/* group exit code if this pidns was rebooted */
40 	unsigned int proc_inum;
41 };
42 
43 extern struct pid_namespace init_pid_ns;
44 
45 #ifdef CONFIG_PID_NS
46 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
47 {
48 	if (ns != &init_pid_ns)
49 		kref_get(&ns->kref);
50 	return ns;
51 }
52 
53 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
54 	struct user_namespace *user_ns, struct pid_namespace *ns);
55 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
56 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
57 extern void put_pid_ns(struct pid_namespace *ns);
58 
59 #else /* !CONFIG_PID_NS */
60 #include <linux/err.h>
61 
62 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
63 {
64 	return ns;
65 }
66 
67 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
68 	struct user_namespace *user_ns, struct pid_namespace *ns)
69 {
70 	if (flags & CLONE_NEWPID)
71 		ns = ERR_PTR(-EINVAL);
72 	return ns;
73 }
74 
75 static inline void put_pid_ns(struct pid_namespace *ns)
76 {
77 }
78 
79 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
80 {
81 	BUG();
82 }
83 
84 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
85 {
86 	return 0;
87 }
88 #endif /* CONFIG_PID_NS */
89 
90 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
91 void pidhash_init(void);
92 void pidmap_init(void);
93 
94 #endif /* _LINUX_PID_NS_H */
95