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 if (ns != &init_pid_ns)
65 ns_ref_inc(ns);
66 return ns;
67 }
68
69 #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
pidns_memfd_noexec_scope(struct pid_namespace * ns)70 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
71 {
72 int scope = MEMFD_NOEXEC_SCOPE_EXEC;
73
74 for (; ns; ns = ns->parent)
75 scope = max(scope, READ_ONCE(ns->memfd_noexec_scope));
76
77 return scope;
78 }
79 #else
pidns_memfd_noexec_scope(struct pid_namespace * ns)80 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
81 {
82 return 0;
83 }
84 #endif
85
86 extern struct pid_namespace *copy_pid_ns(u64 flags,
87 struct user_namespace *user_ns, struct pid_namespace *ns);
88 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
89 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
90 extern void put_pid_ns(struct pid_namespace *ns);
91
92 extern bool pidns_is_ancestor(struct pid_namespace *child,
93 struct pid_namespace *ancestor);
94
95 #else /* !CONFIG_PID_NS */
96 #include <linux/err.h>
97
get_pid_ns(struct pid_namespace * ns)98 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
99 {
100 return ns;
101 }
102
pidns_memfd_noexec_scope(struct pid_namespace * ns)103 static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
104 {
105 return 0;
106 }
107
copy_pid_ns(u64 flags,struct user_namespace * user_ns,struct pid_namespace * ns)108 static inline struct pid_namespace *copy_pid_ns(u64 flags,
109 struct user_namespace *user_ns, struct pid_namespace *ns)
110 {
111 if (flags & CLONE_NEWPID)
112 ns = ERR_PTR(-EINVAL);
113 return ns;
114 }
115
put_pid_ns(struct pid_namespace * ns)116 static inline void put_pid_ns(struct pid_namespace *ns)
117 {
118 }
119
zap_pid_ns_processes(struct pid_namespace * ns)120 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
121 {
122 BUG();
123 }
124
reboot_pid_ns(struct pid_namespace * pid_ns,int cmd)125 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
126 {
127 return 0;
128 }
129
pidns_is_ancestor(struct pid_namespace * child,struct pid_namespace * ancestor)130 static inline bool pidns_is_ancestor(struct pid_namespace *child,
131 struct pid_namespace *ancestor)
132 {
133 return false;
134 }
135 #endif /* CONFIG_PID_NS */
136
137 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
138 void pidhash_init(void);
139 void pid_idr_init(void);
140 int register_pidns_sysctls(struct pid_namespace *pidns);
141 void unregister_pidns_sysctls(struct pid_namespace *pidns);
142
task_is_in_init_pid_ns(struct task_struct * tsk)143 static inline bool task_is_in_init_pid_ns(struct task_struct *tsk)
144 {
145 return task_active_pid_ns(tsk) == &init_pid_ns;
146 }
147
148 #endif /* _LINUX_PID_NS_H */
149