1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_PID_NS_H
3#define _LINUX_PID_NS_H
4
5#include <linux/sched.h>
6#include <linux/bug.h>
7#include <linux/mm.h>
8#include <linux/workqueue.h>
9#include <linux/threads.h>
10#include <linux/nsproxy.h>
11#include <linux/ns_common.h>
12#include <linux/idr.h>
13
14/* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
15#define MAX_PID_NS_LEVEL 32
16
17struct fs_pin;
18
19struct pid_namespace {
20 struct idr idr;
21 struct rcu_head rcu;
22 unsigned int pid_allocated;
23 struct task_struct *child_reaper;
24 struct kmem_cache *pid_cachep;
25 unsigned int level;
26 struct pid_namespace *parent;
27#ifdef CONFIG_BSD_PROCESS_ACCT
28 struct fs_pin *bacct;
29#endif
30 struct user_namespace *user_ns;
31 struct ucounts *ucounts;
32 int reboot; /* group exit code if this pidns was rebooted */
33 struct ns_common ns;
34} __randomize_layout;
35
36extern struct pid_namespace init_pid_ns;
37
38#define PIDNS_ADDING (1U << 31)
39
40#ifdef CONFIG_PID_NS
41static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
42{
43 if (ns != &init_pid_ns)
44 refcount_inc(&ns->ns.count);
45 return ns;
46}
47
48extern struct pid_namespace *copy_pid_ns(unsigned long flags,
49 struct user_namespace *user_ns, struct pid_namespace *ns);
50extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
51extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
52extern void put_pid_ns(struct pid_namespace *ns);
53
54#else /* !CONFIG_PID_NS */
55#include <linux/err.h>
56
57static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
58{
59 return ns;
60}
61
62static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
63 struct user_namespace *user_ns, struct pid_namespace *ns)
64{
65 if (flags & CLONE_NEWPID)
66 ns = ERR_PTR(-EINVAL);
67 return ns;
68}
69
70static inline void put_pid_ns(struct pid_namespace *ns)
71{
72}
73
74static inline void zap_pid_ns_processes(struct pid_namespace *ns)
75{
76 BUG();
77}
78
79static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
80{
81 return 0;
82}
83#endif /* CONFIG_PID_NS */
84
85extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
86void pidhash_init(void);
87void pid_idr_init(void);
88
89static inline bool task_is_in_init_pid_ns(struct task_struct *tsk)
90{
91 return task_active_pid_ns(tsk) == &init_pid_ns;
92}
93
94#endif /* _LINUX_PID_NS_H */
95

source code of linux/include/linux/pid_namespace.h