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        link;
  21         struct list_head        enablers;
  22         struct mm_struct        *mm;
  23         struct user_event_mm    *next;
  24         refcount_t              refcnt;
  25         refcount_t              tasks;
  26         struct rcu_work         put_rwork;
  27 };
  28
  29 extern void user_event_mm_dup(struct task_struct *t,
  30                               struct user_event_mm *old_mm);
  31
  32 extern void user_event_mm_remove(struct task_struct *t);
  33
  34 static inline void user_events_fork(struct task_struct *t,
  35                                     unsigned long clone_flags)
  36 {
  37         struct user_event_mm *old_mm;
  38
  39         if (!t || !current->user_event_mm)
  40                 return;
  41
  42         old_mm = current->user_event_mm;
  43
  44         if (clone_flags & CLONE_VM) {
  45                 t->user_event_mm = old_mm;
  46                 refcount_inc(&old_mm->tasks);
  47                 return;
  48         }
  49
  50         user_event_mm_dup(t, old_mm);
  51 }
  52
  53 static inline void user_events_execve(struct task_struct *t)
  54 {
  55         if (!t || !t->user_event_mm)
  56                 return;
  57
  58         user_event_mm_remove(t);
  59 }
  60
  61 static inline void user_events_exit(struct task_struct *t)
  62 {
  63         if (!t || !t->user_event_mm)
  64                 return;
  65
  66         user_event_mm_remove(t);
  67 }
  68 #else
  69 static inline void user_events_fork(struct task_struct *t,
  70                                     unsigned long clone_flags)
  71 {
  72 }
  73
  74 static inline void user_events_execve(struct task_struct *t)
  75 {
  76 }
  77
  78 static inline void user_events_exit(struct task_struct *t)
  79 {
  80 }
  81 #endif /* CONFIG_USER_EVENTS */
  82
  83 #endif /* _LINUX_USER_EVENTS_H */