xref: /linux-6.15/include/linux/pid_namespace.h (revision 8fdff1dc)
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 PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
17 
18 struct bsd_acct_struct;
19 
20 struct pid_namespace {
21 	struct kref kref;
22 	struct pidmap pidmap[PIDMAP_ENTRIES];
23 	int last_pid;
24 	unsigned int nr_hashed;
25 	struct task_struct *child_reaper;
26 	struct kmem_cache *pid_cachep;
27 	unsigned int level;
28 	struct pid_namespace *parent;
29 #ifdef CONFIG_PROC_FS
30 	struct vfsmount *proc_mnt;
31 #endif
32 #ifdef CONFIG_BSD_PROCESS_ACCT
33 	struct bsd_acct_struct *bacct;
34 #endif
35 	struct user_namespace *user_ns;
36 	struct work_struct proc_work;
37 	kgid_t pid_gid;
38 	int hide_pid;
39 	int reboot;	/* group exit code if this pidns was rebooted */
40 	unsigned int proc_inum;
41 };
42 
43 extern struct pid_namespace init_pid_ns;
44 
45 #define PIDNS_HASH_ADDING (1U << 31)
46 
47 #ifdef CONFIG_PID_NS
48 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
49 {
50 	if (ns != &init_pid_ns)
51 		kref_get(&ns->kref);
52 	return ns;
53 }
54 
55 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
56 	struct user_namespace *user_ns, struct pid_namespace *ns);
57 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
58 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
59 extern void put_pid_ns(struct pid_namespace *ns);
60 
61 #else /* !CONFIG_PID_NS */
62 #include <linux/err.h>
63 
64 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
65 {
66 	return ns;
67 }
68 
69 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
70 	struct user_namespace *user_ns, struct pid_namespace *ns)
71 {
72 	if (flags & CLONE_NEWPID)
73 		ns = ERR_PTR(-EINVAL);
74 	return ns;
75 }
76 
77 static inline void put_pid_ns(struct pid_namespace *ns)
78 {
79 }
80 
81 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
82 {
83 	BUG();
84 }
85 
86 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
87 {
88 	return 0;
89 }
90 #endif /* CONFIG_PID_NS */
91 
92 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
93 void pidhash_init(void);
94 void pidmap_init(void);
95 
96 #endif /* _LINUX_PID_NS_H */
97