Line data    Source code

       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    36945457 : static inline void user_events_execve(struct task_struct *t)
      55             : {
      56    36945457 :         if (!t || !t->user_event_mm)
      57             :                 return;
      58             : 
      59           0 :         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 */