xref: /linux-6.15/include/linux/pid_namespace.h (revision 5cc54451)
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 BITS_PER_PAGE		(PAGE_SIZE * 8)
17 #define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
18 #define PIDMAP_ENTRIES		((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
19 
20 struct bsd_acct_struct;
21 
22 struct pid_namespace {
23 	struct kref kref;
24 	struct pidmap pidmap[PIDMAP_ENTRIES];
25 	int last_pid;
26 	unsigned int nr_hashed;
27 	struct task_struct *child_reaper;
28 	struct kmem_cache *pid_cachep;
29 	unsigned int level;
30 	struct pid_namespace *parent;
31 #ifdef CONFIG_PROC_FS
32 	struct vfsmount *proc_mnt;
33 #endif
34 #ifdef CONFIG_BSD_PROCESS_ACCT
35 	struct bsd_acct_struct *bacct;
36 #endif
37 	struct user_namespace *user_ns;
38 	struct work_struct proc_work;
39 	kgid_t pid_gid;
40 	int hide_pid;
41 	int reboot;	/* group exit code if this pidns was rebooted */
42 	unsigned int proc_inum;
43 };
44 
45 extern struct pid_namespace init_pid_ns;
46 
47 #define PIDNS_HASH_ADDING (1U << 31)
48 
49 #ifdef CONFIG_PID_NS
50 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
51 {
52 	if (ns != &init_pid_ns)
53 		kref_get(&ns->kref);
54 	return ns;
55 }
56 
57 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
58 	struct user_namespace *user_ns, struct pid_namespace *ns);
59 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
60 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
61 extern void put_pid_ns(struct pid_namespace *ns);
62 
63 #else /* !CONFIG_PID_NS */
64 #include <linux/err.h>
65 
66 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
67 {
68 	return ns;
69 }
70 
71 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
72 	struct user_namespace *user_ns, struct pid_namespace *ns)
73 {
74 	if (flags & CLONE_NEWPID)
75 		ns = ERR_PTR(-EINVAL);
76 	return ns;
77 }
78 
79 static inline void put_pid_ns(struct pid_namespace *ns)
80 {
81 }
82 
83 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
84 {
85 	BUG();
86 }
87 
88 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
89 {
90 	return 0;
91 }
92 #endif /* CONFIG_PID_NS */
93 
94 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
95 void pidhash_init(void);
96 void pidmap_init(void);
97 
98 #endif /* _LINUX_PID_NS_H */
99