include/linux/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/kref.h>
  12 #include <linux/ns_common.h>
  13 #include <linux/idr.h>
  14
  15 /* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
  16 #define MAX_PID_NS_LEVEL 32
  17
  18 struct fs_pin;
  19
  20 struct pid_namespace {
  21         struct kref kref;
  22         struct idr idr;
  23         struct rcu_head rcu;
  24         unsigned int pid_allocated;
  25         struct task_struct *child_reaper;
  26         struct kmem_cache *pid_cachep;
  27         unsigned int level;
  28         struct pid_namespace *parent;
  29 #ifdef CONFIG_BSD_PROCESS_ACCT
  30         struct fs_pin *bacct;
  31 #endif
  32         struct user_namespace *user_ns;
  33         struct ucounts *ucounts;
  34         int reboot;     /* group exit code if this pidns was rebooted */
  35         struct ns_common ns;
  36 } __randomize_layout;
  37
  38 extern struct pid_namespace init_pid_ns;
  39
  40 #define PIDNS_ADDING (1U << 31)
  41
  42 #ifdef CONFIG_PID_NS
  43 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  44 {
  45         if (ns != &init_pid_ns)
  46                 kref_get(&ns->kref);
  47         return ns;
  48 }
  49
  50 extern struct pid_namespace *copy_pid_ns(unsigned long flags,
  51         struct user_namespace *user_ns, struct pid_namespace *ns);
  52 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
  53 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
  54 extern void put_pid_ns(struct pid_namespace *ns);
  55
  56 #else /* !CONFIG_PID_NS */
  57 #include <linux/err.h>
  58
  59 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  60 {
  61         return ns;
  62 }
  63
  64 static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
  65         struct user_namespace *user_ns, struct pid_namespace *ns)
  66 {
  67         if (flags & CLONE_NEWPID)
  68                 ns = ERR_PTR(-EINVAL);
  69         return ns;
  70 }
  71
  72 static inline void put_pid_ns(struct pid_namespace *ns)
  73 {
  74 }
  75
  76 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
  77 {
  78         BUG();
  79 }
  80
  81 static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
  82 {
  83         return 0;
  84 }
  85 #endif /* CONFIG_PID_NS */
  86
  87 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
  88 void pidhash_init(void);
  89 void pid_idr_init(void);
  90
  91 #endif /* _LINUX_PID_NS_H */