include/linux/user_events.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (c) 2022, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Beau Belgrave <beaub@linux.microsoft.com>
   7  */
   8
   9 #ifndef _LINUX_USER_EVENTS_H
  10 #define _LINUX_USER_EVENTS_H
  11
  12 #include <linux/list.h>
  13 #include <linux/refcount.h>
  14 #include <linux/mm_types.h>
  15 #include <linux/workqueue.h>
  16 #include <uapi/linux/user_events.h>
  17
  18 #ifdef CONFIG_USER_EVENTS
  19 struct user_event_mm {
  20         struct list_head        mms_link;
  21         struct list_head        enablers;
  22         struct mm_struct        *mm;
  23         /* Used for one-shot lists, protected by event_mutex */
  24         struct user_event_mm    *next;
  25         refcount_t              refcnt;
  26         refcount_t              tasks;
  27         struct rcu_work         put_rwork;
  28 };
  29
  30 extern void user_event_mm_dup(struct task_struct *t,
  31                               struct user_event_mm *old_mm);
  32
  33 extern void user_event_mm_remove(struct task_struct *t);
  34
  35 static inline void user_events_fork(struct task_struct *t,
  36                                     unsigned long clone_flags)
  37 {
  38         struct user_event_mm *old_mm;
  39
  40         if (!t || !current->user_event_mm)
  41                 return;
  42
  43         old_mm = current->user_event_mm;
  44
  45         if (clone_flags & CLONE_VM) {
  46                 t->user_event_mm = old_mm;
  47                 refcount_inc(&old_mm->tasks);
  48                 return;
  49         }
  50
  51         user_event_mm_dup(t, old_mm);
  52 }
  53
  54 static inline void user_events_execve(struct task_struct *t)
  55 {
  56         if (!t || !t->user_event_mm)
  57                 return;
  58
  59         user_event_mm_remove(t);
  60 }
  61
  62 static inline void user_events_exit(struct task_struct *t)
  63 {
  64         if (!t || !t->user_event_mm)
  65                 return;
  66
  67         user_event_mm_remove(t);
  68 }
  69 #else
  70 static inline void user_events_fork(struct task_struct *t,
  71                                     unsigned long clone_flags)
  72 {
  73 }
  74
  75 static inline void user_events_execve(struct task_struct *t)
  76 {
  77 }
  78
  79 static inline void user_events_exit(struct task_struct *t)
  80 {
  81 }
  82 #endif /* CONFIG_USER_EVENTS */
  83
  84 #endif /* _LINUX_USER_EVENTS_H */