xref: /linux-6.15/include/linux/pid_namespace.h (revision f5e4e7fd)
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 
12 struct pidmap {
13        atomic_t nr_free;
14        void *page;
15 };
16 
17 #define BITS_PER_PAGE		(PAGE_SIZE * 8)
18 #define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
19 #define PIDMAP_ENTRIES		((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
20 
21 struct bsd_acct_struct;
22 
23 struct pid_namespace {
24 	struct kref kref;
25 	struct pidmap pidmap[PIDMAP_ENTRIES];
26 	int last_pid;
27 	unsigned int nr_hashed;
28 	struct task_struct *child_reaper;
29 	struct kmem_cache *pid_cachep;
30 	unsigned int level;
31 	struct pid_namespace *parent;
32 #ifdef CONFIG_PROC_FS
33 	struct vfsmount *proc_mnt;
34 	struct dentry *proc_self;
35 #endif
36 #ifdef CONFIG_BSD_PROCESS_ACCT
37 	struct bsd_acct_struct *bacct;
38 #endif
39 	struct user_namespace *user_ns;
40 	struct work_struct proc_work;
41 	kgid_t pid_gid;
42 	int hide_pid;
43 	int reboot;	/* group exit code if this pidns was rebooted */
44 	unsigned int proc_inum;
45 };
46 
47 extern struct pid_namespace init_pid_ns;
48 
49 #define PIDNS_HASH_ADDING (1U << 31)
50 
51 #ifdef CONFIG_PID_NS
52 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
53 {
54 	if (ns != &init_pid_ns)
55 		kref_get(&ns->kref);
56 	return ns;
57 }
58 
59 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
60 	struct user_namespace *user_ns, struct pid_namespace *ns);
61 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
62 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
63 extern void put_pid_ns(struct pid_namespace *ns);
64 
65 #else /* !CONFIG_PID_NS */
66 #include <linux/err.h>
67 
68 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
69 {
70 	return ns;
71 }
72 
73 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
74 	struct user_namespace *user_ns, struct pid_namespace *ns)
75 {
76 	if (flags & CLONE_NEWPID)
77 		ns = ERR_PTR(-EINVAL);
78 	return ns;
79 }
80 
81 static inline void put_pid_ns(struct pid_namespace *ns)
82 {
83 }
84 
85 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
86 {
87 	BUG();
88 }
89 
90 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
91 {
92 	return 0;
93 }
94 #endif /* CONFIG_PID_NS */
95 
96 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
97 void pidhash_init(void);
98 void pidmap_init(void);
99 
100 #endif /* _LINUX_PID_NS_H */
101