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 
17 struct fs_pin;
18 
19 struct 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 
36 extern struct pid_namespace init_pid_ns;
37 
38 #define PIDNS_ADDING (1U << 31)
39 
40 #ifdef CONFIG_PID_NS
get_pid_ns(struct pid_namespace * ns)41 static 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 
48 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
49 	struct user_namespace *user_ns, struct pid_namespace *ns);
50 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
51 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
52 extern void put_pid_ns(struct pid_namespace *ns);
53 
54 #else /* !CONFIG_PID_NS */
55 #include <linux/err.h>
56 
get_pid_ns(struct pid_namespace * ns)57 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
58 {
59 	return ns;
60 }
61 
copy_pid_ns(unsigned long flags,struct user_namespace * user_ns,struct pid_namespace * ns)62 static 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 
put_pid_ns(struct pid_namespace * ns)70 static inline void put_pid_ns(struct pid_namespace *ns)
71 {
72 }
73 
zap_pid_ns_processes(struct pid_namespace * ns)74 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
75 {
76 	BUG();
77 }
78 
reboot_pid_ns(struct pid_namespace * pid_ns,int cmd)79 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
80 {
81 	return 0;
82 }
83 #endif /* CONFIG_PID_NS */
84 
85 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
86 void pidhash_init(void);
87 void pid_idr_init(void);
88 
task_is_in_init_pid_ns(struct task_struct * tsk)89 static 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