pid_namespace.h

  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	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
 52extern struct pid_namespace init_pid_ns;
 53
 54#define PIDNS_ADDING (1U << 31)
 55
 56#ifdef CONFIG_PID_NS
 57static inline struct pid_namespace *to_pid_ns(struct ns_common *ns)
 58{
 59	return container_of(ns, struct pid_namespace, ns);
 60}
 61
 62static 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)
 69static 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
 79static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
 80{
 81	return 0;
 82}
 83#endif
 84
 85extern struct pid_namespace *copy_pid_ns(u64 flags,
 86	struct user_namespace *user_ns, struct pid_namespace *ns);
 87extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
 88extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
 89extern void put_pid_ns(struct pid_namespace *ns);
 90
 91extern 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
 97static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
 98{
 99	return ns;
100}
101
102static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
103{
104	return 0;
105}
106
107static 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
115static inline void put_pid_ns(struct pid_namespace *ns)
116{
117}
118
119static inline void zap_pid_ns_processes(struct pid_namespace *ns)
120{
121	BUG();
122}
123
124static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
125{
126	return 0;
127}
128
129static 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
136extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
137void pidhash_init(void);
138void pid_idr_init(void);
139int register_pidns_sysctls(struct pid_namespace *pidns);
140void unregister_pidns_sysctls(struct pid_namespace *pidns);
141
142static 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 */