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 #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
26 struct 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
46 extern struct pid_namespace init_pid_ns;
47
48 #define PIDNS_ADDING (1U << 31)
49
50 #ifdef CONFIG_PID_NS
get_pid_ns(struct pid_namespace * ns)51 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
52 {
53 if (ns != &init_pid_ns)
54 refcount_inc(&ns->ns.count);
55 return ns;
56 }
57
58 #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
pidns_memfd_noexec_scope(struct pid_namespace * ns)59 static 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
pidns_memfd_noexec_scope(struct pid_namespace * ns)69 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
70 {
71 return 0;
72 }
73 #endif
74
75 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
76 struct user_namespace *user_ns, struct pid_namespace *ns);
77 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
78 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
79 extern void put_pid_ns(struct pid_namespace *ns);
80
81 #else /* !CONFIG_PID_NS */
82 #include <linux/err.h>
83
get_pid_ns(struct pid_namespace * ns)84 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
85 {
86 return ns;
87 }
88
pidns_memfd_noexec_scope(struct pid_namespace * ns)89 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
90 {
91 return 0;
92 }
93
copy_pid_ns(unsigned long flags,struct user_namespace * user_ns,struct pid_namespace * ns)94 static 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
put_pid_ns(struct pid_namespace * ns)102 static inline void put_pid_ns(struct pid_namespace *ns)
103 {
104 }
105
zap_pid_ns_processes(struct pid_namespace * ns)106 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
107 {
108 BUG();
109 }
110
reboot_pid_ns(struct pid_namespace * pid_ns,int cmd)111 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
112 {
113 return 0;
114 }
115 #endif /* CONFIG_PID_NS */
116
117 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
118 void pidhash_init(void);
119 void pid_idr_init(void);
120
task_is_in_init_pid_ns(struct task_struct * tsk)121 static 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