xref: /linux-6.15/include/linux/pid_namespace.h (revision bbb03029)
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/workqueue.h>
8 #include <linux/threads.h>
9 #include <linux/nsproxy.h>
10 #include <linux/kref.h>
11 #include <linux/ns_common.h>
12 
13 struct pidmap {
14        atomic_t nr_free;
15        void *page;
16 };
17 
18 #define BITS_PER_PAGE		(PAGE_SIZE * 8)
19 #define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
20 #define PIDMAP_ENTRIES		((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
21 
22 struct fs_pin;
23 
24 enum { /* definitions for pid_namespace's hide_pid field */
25 	HIDEPID_OFF	  = 0,
26 	HIDEPID_NO_ACCESS = 1,
27 	HIDEPID_INVISIBLE = 2,
28 };
29 
30 struct pid_namespace {
31 	struct kref kref;
32 	struct pidmap pidmap[PIDMAP_ENTRIES];
33 	struct rcu_head rcu;
34 	int last_pid;
35 	unsigned int nr_hashed;
36 	struct task_struct *child_reaper;
37 	struct kmem_cache *pid_cachep;
38 	unsigned int level;
39 	struct pid_namespace *parent;
40 #ifdef CONFIG_PROC_FS
41 	struct vfsmount *proc_mnt;
42 	struct dentry *proc_self;
43 	struct dentry *proc_thread_self;
44 #endif
45 #ifdef CONFIG_BSD_PROCESS_ACCT
46 	struct fs_pin *bacct;
47 #endif
48 	struct user_namespace *user_ns;
49 	struct ucounts *ucounts;
50 	struct work_struct proc_work;
51 	kgid_t pid_gid;
52 	int hide_pid;
53 	int reboot;	/* group exit code if this pidns was rebooted */
54 	struct ns_common ns;
55 } __randomize_layout;
56 
57 extern struct pid_namespace init_pid_ns;
58 
59 #define PIDNS_HASH_ADDING (1U << 31)
60 
61 #ifdef CONFIG_PID_NS
62 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
63 {
64 	if (ns != &init_pid_ns)
65 		kref_get(&ns->kref);
66 	return ns;
67 }
68 
69 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
70 	struct user_namespace *user_ns, struct pid_namespace *ns);
71 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
72 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
73 extern void put_pid_ns(struct pid_namespace *ns);
74 
75 #else /* !CONFIG_PID_NS */
76 #include <linux/err.h>
77 
78 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
79 {
80 	return ns;
81 }
82 
83 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
84 	struct user_namespace *user_ns, struct pid_namespace *ns)
85 {
86 	if (flags & CLONE_NEWPID)
87 		ns = ERR_PTR(-EINVAL);
88 	return ns;
89 }
90 
91 static inline void put_pid_ns(struct pid_namespace *ns)
92 {
93 }
94 
95 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
96 {
97 	BUG();
98 }
99 
100 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
101 {
102 	return 0;
103 }
104 #endif /* CONFIG_PID_NS */
105 
106 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
107 void pidhash_init(void);
108 void pidmap_init(void);
109 
110 #endif /* _LINUX_PID_NS_H */
111