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 int pid_max;
34 struct pid_namespace *parent;
35 #ifdef CONFIG_BSD_PROCESS_ACCT
36 struct fs_pin *bacct;
37 #endif
38 struct user_namespace *user_ns;
39 struct ucounts *ucounts;
40 int reboot; /* group exit code if this pidns was rebooted */
41 struct ns_common ns;
42 struct work_struct work;
43 #ifdef CONFIG_SYSCTL
44 struct ctl_table_set set;
45 struct ctl_table_header *sysctls;
46 #if defined(CONFIG_MEMFD_CREATE)
47 int memfd_noexec_scope;
48 #endif
49 #endif
50 } __randomize_layout;
51
52 extern struct pid_namespace init_pid_ns;
53
54 #define PIDNS_ADDING (1U << 31)
55
56 #ifdef CONFIG_PID_NS
to_pid_ns(struct ns_common * ns)57 static inline struct pid_namespace *to_pid_ns(struct ns_common *ns)
58 {
59 return container_of(ns, struct pid_namespace, ns);
60 }
61
get_pid_ns(struct pid_namespace * ns)62 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
63 {
64 ns_ref_inc(ns);
65 return ns;
66 }
67
68 #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
pidns_memfd_noexec_scope(struct pid_namespace * ns)69 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
70 {
71 int scope = MEMFD_NOEXEC_SCOPE_EXEC;
72
73 for (; ns; ns = ns->parent)
74 scope = max(scope, READ_ONCE(ns->memfd_noexec_scope));
75
76 return scope;
77 }
78 #else
pidns_memfd_noexec_scope(struct pid_namespace * ns)79 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
80 {
81 return 0;
82 }
83 #endif
84
85 extern struct pid_namespace *copy_pid_ns(u64 flags,
86 struct user_namespace *user_ns, struct pid_namespace *ns);
87 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
88 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
89 extern void put_pid_ns(struct pid_namespace *ns);
90
91 extern bool pidns_is_ancestor(struct pid_namespace *child,
92 struct pid_namespace *ancestor);
93
94 #else /* !CONFIG_PID_NS */
95 #include <linux/err.h>
96
get_pid_ns(struct pid_namespace * ns)97 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
98 {
99 return ns;
100 }
101
pidns_memfd_noexec_scope(struct pid_namespace * ns)102 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
103 {
104 return 0;
105 }
106
copy_pid_ns(u64 flags,struct user_namespace * user_ns,struct pid_namespace * ns)107 static inline struct pid_namespace *copy_pid_ns(u64 flags,
108 struct user_namespace *user_ns, struct pid_namespace *ns)
109 {
110 if (flags & CLONE_NEWPID)
111 ns = ERR_PTR(-EINVAL);
112 return ns;
113 }
114
put_pid_ns(struct pid_namespace * ns)115 static inline void put_pid_ns(struct pid_namespace *ns)
116 {
117 }
118
zap_pid_ns_processes(struct pid_namespace * ns)119 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
120 {
121 BUG();
122 }
123
reboot_pid_ns(struct pid_namespace * pid_ns,int cmd)124 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
125 {
126 return 0;
127 }
128
pidns_is_ancestor(struct pid_namespace * child,struct pid_namespace * ancestor)129 static inline bool pidns_is_ancestor(struct pid_namespace *child,
130 struct pid_namespace *ancestor)
131 {
132 return false;
133 }
134 #endif /* CONFIG_PID_NS */
135
136 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
137 void pidhash_init(void);
138 void pid_idr_init(void);
139 int register_pidns_sysctls(struct pid_namespace *pidns);
140 void unregister_pidns_sysctls(struct pid_namespace *pidns);
141
task_is_in_init_pid_ns(struct task_struct * tsk)142 static inline bool task_is_in_init_pid_ns(struct task_struct *tsk)
143 {
144 return task_active_pid_ns(tsk) == &init_pid_ns;
145 }
146
147 #endif /* _LINUX_PID_NS_H */
148