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
19#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
20/* modes for vm.memfd_noexec sysctl */
21#define MEMFD_NOEXEC_SCOPE_EXEC 0 /* MFD_EXEC implied if unset */
22#define MEMFD_NOEXEC_SCOPE_NOEXEC_SEAL 1 /* MFD_NOEXEC_SEAL implied if unset */
23#define MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED 2 /* same as 1, except MFD_EXEC rejected */
24#endif
25
26struct pid_namespace {
27 struct idr idr;
28 struct rcu_head rcu;
29 unsigned int pid_allocated;
30 struct task_struct *child_reaper;
31 struct kmem_cache *pid_cachep;
32 unsigned int level;
33 struct pid_namespace *parent;
34#ifdef CONFIG_BSD_PROCESS_ACCT
35 struct fs_pin *bacct;
36#endif
37 struct user_namespace *user_ns;
38 struct ucounts *ucounts;
39 int reboot; /* group exit code if this pidns was rebooted */
40 struct ns_common ns;
41#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
42 int memfd_noexec_scope;
43#endif
44} __randomize_layout;
45
46extern struct pid_namespace init_pid_ns;
47
48#define PIDNS_ADDING (1U << 31)
49
50#ifdef CONFIG_PID_NS
51static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
52{
53 if (ns != &init_pid_ns)
54 refcount_inc(r: &ns->ns.count);
55 return ns;
56}
57
58#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
59static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
60{
61 int scope = MEMFD_NOEXEC_SCOPE_EXEC;
62
63 for (; ns; ns = ns->parent)
64 scope = max(scope, READ_ONCE(ns->memfd_noexec_scope));
65
66 return scope;
67}
68#else
69static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
70{
71 return 0;
72}
73#endif
74
75extern struct pid_namespace *copy_pid_ns(unsigned long flags,
76 struct user_namespace *user_ns, struct pid_namespace *ns);
77extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
78extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
79extern void put_pid_ns(struct pid_namespace *ns);
80
81#else /* !CONFIG_PID_NS */
82#include <linux/err.h>
83
84static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
85{
86 return ns;
87}
88
89static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
90{
91 return 0;
92}
93
94static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
95 struct user_namespace *user_ns, struct pid_namespace *ns)
96{
97 if (flags & CLONE_NEWPID)
98 ns = ERR_PTR(-EINVAL);
99 return ns;
100}
101
102static inline void put_pid_ns(struct pid_namespace *ns)
103{
104}
105
106static inline void zap_pid_ns_processes(struct pid_namespace *ns)
107{
108 BUG();
109}
110
111static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
112{
113 return 0;
114}
115#endif /* CONFIG_PID_NS */
116
117extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
118void pidhash_init(void);
119void pid_idr_init(void);
120
121static inline bool task_is_in_init_pid_ns(struct task_struct *tsk)
122{
123 return task_active_pid_ns(tsk) == &init_pid_ns;
124}
125
126#endif /* _LINUX_PID_NS_H */
127

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