drivers/android/binder_alloc.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2017 Google, Inc.
   4  */
   5
   6 #ifndef _LINUX_BINDER_ALLOC_H
   7 #define _LINUX_BINDER_ALLOC_H
   8
   9 #include <linux/rbtree.h>
  10 #include <linux/list.h>
  11 #include <linux/mm.h>
  12 #include <linux/rtmutex.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/slab.h>
  15 #include <linux/list_lru.h>
  16 #include <uapi/linux/android/binder.h>
  17
  18 extern struct list_lru binder_alloc_lru;
  19 struct binder_transaction;
  20
  21 /**
  22  * struct binder_buffer - buffer used for binder transactions
  23  * @entry:              entry alloc->buffers
  24  * @rb_node:            node for allocated_buffers/free_buffers rb trees
  25  * @free:               %true if buffer is free
  26  * @clear_on_free:      %true if buffer must be zeroed after use
  27  * @allow_user_free:    %true if user is allowed to free buffer
  28  * @async_transaction:  %true if buffer is in use for an async txn
  29  * @debug_id:           unique ID for debugging
  30  * @transaction:        pointer to associated struct binder_transaction
  31  * @target_node:        struct binder_node associated with this buffer
  32  * @data_size:          size of @transaction data
  33  * @offsets_size:       size of array of offsets
  34  * @extra_buffers_size: size of space for other objects (like sg lists)
  35  * @user_data:          user pointer to base of buffer space
  36  *
  37  * Bookkeeping structure for binder transaction buffers
  38  */
  39 struct binder_buffer {
  40         struct list_head entry; /* free and allocated entries by address */
  41         struct rb_node rb_node; /* free entry by size or allocated entry */
  42                                 /* by address */
  43         unsigned free:1;
  44         unsigned clear_on_free:1;
  45         unsigned allow_user_free:1;
  46         unsigned async_transaction:1;
  47         unsigned debug_id:28;
  48
  49         struct binder_transaction *transaction;
  50
  51         struct binder_node *target_node;
  52         size_t data_size;
  53         size_t offsets_size;
  54         size_t extra_buffers_size;
  55         void __user *user_data;
  56 };
  57
  58 /**
  59  * struct binder_lru_page - page object used for binder shrinker
  60  * @page_ptr: pointer to physical page in mmap'd space
  61  * @lru:      entry in binder_alloc_lru
  62  * @alloc:    binder_alloc for a proc
  63  */
  64 struct binder_lru_page {
  65         struct list_head lru;
  66         struct page *page_ptr;
  67         struct binder_alloc *alloc;
  68 };
  69
  70 /**
  71  * struct binder_alloc - per-binder proc state for binder allocator
  72  * @vma:                vm_area_struct passed to mmap_handler
  73  *                      (invarient after mmap)
  74  * @tsk:                tid for task that called init for this proc
  75  *                      (invariant after init)
  76  * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
  77  * @buffer:             base of per-proc address space mapped via mmap
  78  * @buffers:            list of all buffers for this proc
  79  * @free_buffers:       rb tree of buffers available for allocation
  80  *                      sorted by size
  81  * @allocated_buffers:  rb tree of allocated buffers sorted by address
  82  * @free_async_space:   VA space available for async buffers. This is
  83  *                      initialized at mmap time to 1/2 the full VA space
  84  * @pages:              array of binder_lru_page
  85  * @buffer_size:        size of address space specified via mmap
  86  * @pid:                pid for associated binder_proc (invariant after init)
  87  * @pages_high:         high watermark of offset in @pages
  88  *
  89  * Bookkeeping structure for per-proc address space management for binder
  90  * buffers. It is normally initialized during binder_init() and binder_mmap()
  91  * calls. The address space is used for both user-visible buffers and for
  92  * struct binder_buffer objects used to track the user buffers
  93  */
  94 struct binder_alloc {
  95         struct mutex mutex;
  96         struct vm_area_struct *vma;
  97         struct mm_struct *vma_vm_mm;
  98         void __user *buffer;
  99         struct list_head buffers;
 100         struct rb_root free_buffers;
 101         struct rb_root allocated_buffers;
 102         size_t free_async_space;
 103         struct binder_lru_page *pages;
 104         size_t buffer_size;
 105         uint32_t buffer_free;
 106         int pid;
 107         size_t pages_high;
 108 };
 109
 110 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
 111 void binder_selftest_alloc(struct binder_alloc *alloc);
 112 #else
 113 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 114 #endif
 115 enum lru_status binder_alloc_free_page(struct list_head *item,
 116                                        struct list_lru_one *lru,
 117                                        spinlock_t *lock, void *cb_arg);
 118 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 119                                                   size_t data_size,
 120                                                   size_t offsets_size,
 121                                                   size_t extra_buffers_size,
 122                                                   int is_async);
 123 extern void binder_alloc_init(struct binder_alloc *alloc);
 124 extern int binder_alloc_shrinker_init(void);
 125 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 126 extern struct binder_buffer *
 127 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 128                              uintptr_t user_ptr);
 129 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 130                                   struct binder_buffer *buffer);
 131 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 132                                      struct vm_area_struct *vma);
 133 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 134 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 135 extern void binder_alloc_print_allocated(struct seq_file *m,
 136                                          struct binder_alloc *alloc);
 137 void binder_alloc_print_pages(struct seq_file *m,
 138                               struct binder_alloc *alloc);
 139
 140 /**
 141  * binder_alloc_get_free_async_space() - get free space available for async
 142  * @alloc:      binder_alloc for this proc
 143  *
 144  * Return:      the bytes remaining in the address-space for async transactions
 145  */
 146 static inline size_t
 147 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
 148 {
 149         size_t free_async_space;
 150
 151         mutex_lock(&alloc->mutex);
 152         free_async_space = alloc->free_async_space;
 153         mutex_unlock(&alloc->mutex);
 154         return free_async_space;
 155 }
 156
 157 unsigned long
 158 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
 159                                  struct binder_buffer *buffer,
 160                                  binder_size_t buffer_offset,
 161                                  const void __user *from,
 162                                  size_t bytes);
 163
 164 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
 165                                 struct binder_buffer *buffer,
 166                                 binder_size_t buffer_offset,
 167                                 void *src,
 168                                 size_t bytes);
 169
 170 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
 171                                   void *dest,
 172                                   struct binder_buffer *buffer,
 173                                   binder_size_t buffer_offset,
 174                                   size_t bytes);
 175
 176 #endif /* _LINUX_BINDER_ALLOC_H */
 177