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  * @pid:                pid to attribute the buffer to (caller)
  37  *
  38  * Bookkeeping structure for binder transaction buffers
  39  */
  40 struct binder_buffer {
  41         struct list_head entry; /* free and allocated entries by address */
  42         struct rb_node rb_node; /* free entry by size or allocated entry */
  43                                 /* by address */
  44         unsigned free:1;
  45         unsigned clear_on_free:1;
  46         unsigned allow_user_free:1;
  47         unsigned async_transaction:1;
  48         unsigned debug_id:28;
  49
  50         struct binder_transaction *transaction;
  51
  52         struct binder_node *target_node;
  53         size_t data_size;
  54         size_t offsets_size;
  55         size_t extra_buffers_size;
  56         void __user *user_data;
  57         int    pid;
  58 };
  59
  60 /**
  61  * struct binder_lru_page - page object used for binder shrinker
  62  * @page_ptr: pointer to physical page in mmap'd space
  63  * @lru:      entry in binder_alloc_lru
  64  * @alloc:    binder_alloc for a proc
  65  */
  66 struct binder_lru_page {
  67         struct list_head lru;
  68         struct page *page_ptr;
  69         struct binder_alloc *alloc;
  70 };
  71
  72 /**
  73  * struct binder_alloc - per-binder proc state for binder allocator
  74  * @vma:                vm_area_struct passed to mmap_handler
  75  *                      (invarient after mmap)
  76  * @tsk:                tid for task that called init for this proc
  77  *                      (invariant after init)
  78  * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
  79  * @buffer:             base of per-proc address space mapped via mmap
  80  * @buffers:            list of all buffers for this proc
  81  * @free_buffers:       rb tree of buffers available for allocation
  82  *                      sorted by size
  83  * @allocated_buffers:  rb tree of allocated buffers sorted by address
  84  * @free_async_space:   VA space available for async buffers. This is
  85  *                      initialized at mmap time to 1/2 the full VA space
  86  * @pages:              array of binder_lru_page
  87  * @buffer_size:        size of address space specified via mmap
  88  * @pid:                pid for associated binder_proc (invariant after init)
  89  * @pages_high:         high watermark of offset in @pages
  90  *
  91  * Bookkeeping structure for per-proc address space management for binder
  92  * buffers. It is normally initialized during binder_init() and binder_mmap()
  93  * calls. The address space is used for both user-visible buffers and for
  94  * struct binder_buffer objects used to track the user buffers
  95  */
  96 struct binder_alloc {
  97         struct mutex mutex;
  98         struct vm_area_struct *vma;
  99         struct mm_struct *vma_vm_mm;
 100         void __user *buffer;
 101         struct list_head buffers;
 102         struct rb_root free_buffers;
 103         struct rb_root allocated_buffers;
 104         size_t free_async_space;
 105         struct binder_lru_page *pages;
 106         size_t buffer_size;
 107         uint32_t buffer_free;
 108         int pid;
 109         size_t pages_high;
 110 };
 111
 112 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
 113 void binder_selftest_alloc(struct binder_alloc *alloc);
 114 #else
 115 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 116 #endif
 117 enum lru_status binder_alloc_free_page(struct list_head *item,
 118                                        struct list_lru_one *lru,
 119                                        spinlock_t *lock, void *cb_arg);
 120 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 121                                                   size_t data_size,
 122                                                   size_t offsets_size,
 123                                                   size_t extra_buffers_size,
 124                                                   int is_async,
 125                                                   int pid);
 126 extern void binder_alloc_init(struct binder_alloc *alloc);
 127 extern int binder_alloc_shrinker_init(void);
 128 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 129 extern struct binder_buffer *
 130 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 131                              uintptr_t user_ptr);
 132 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 133                                   struct binder_buffer *buffer);
 134 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 135                                      struct vm_area_struct *vma);
 136 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 137 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 138 extern void binder_alloc_print_allocated(struct seq_file *m,
 139                                          struct binder_alloc *alloc);
 140 void binder_alloc_print_pages(struct seq_file *m,
 141                               struct binder_alloc *alloc);
 142
 143 /**
 144  * binder_alloc_get_free_async_space() - get free space available for async
 145  * @alloc:      binder_alloc for this proc
 146  *
 147  * Return:      the bytes remaining in the address-space for async transactions
 148  */
 149 static inline size_t
 150 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
 151 {
 152         size_t free_async_space;
 153
 154         mutex_lock(&alloc->mutex);
 155         free_async_space = alloc->free_async_space;
 156         mutex_unlock(&alloc->mutex);
 157         return free_async_space;
 158 }
 159
 160 unsigned long
 161 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
 162                                  struct binder_buffer *buffer,
 163                                  binder_size_t buffer_offset,
 164                                  const void __user *from,
 165                                  size_t bytes);
 166
 167 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
 168                                 struct binder_buffer *buffer,
 169                                 binder_size_t buffer_offset,
 170                                 void *src,
 171                                 size_t bytes);
 172
 173 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
 174                                   void *dest,
 175                                   struct binder_buffer *buffer,
 176                                   binder_size_t buffer_offset,
 177                                   size_t bytes);
 178
 179 #endif /* _LINUX_BINDER_ALLOC_H */
 180