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  * @oneway_spam_suspect: %true if total async allocate size just exceed
  30  * spamming detect threshold
  31  * @debug_id:           unique ID for debugging
  32  * @transaction:        pointer to associated struct binder_transaction
  33  * @target_node:        struct binder_node associated with this buffer
  34  * @data_size:          size of @transaction data
  35  * @offsets_size:       size of array of offsets
  36  * @extra_buffers_size: size of space for other objects (like sg lists)
  37  * @user_data:          user pointer to base of buffer space
  38  * @pid:                pid to attribute the buffer to (caller)
  39  *
  40  * Bookkeeping structure for binder transaction buffers
  41  */
  42 struct binder_buffer {
  43         struct list_head entry; /* free and allocated entries by address */
  44         struct rb_node rb_node; /* free entry by size or allocated entry */
  45                                 /* by address */
  46         unsigned free:1;
  47         unsigned clear_on_free:1;
  48         unsigned allow_user_free:1;
  49         unsigned async_transaction:1;
  50         unsigned oneway_spam_suspect:1;
  51         unsigned debug_id:27;
  52
  53         struct binder_transaction *transaction;
  54
  55         struct binder_node *target_node;
  56         size_t data_size;
  57         size_t offsets_size;
  58         size_t extra_buffers_size;
  59         void __user *user_data;
  60         int    pid;
  61 };
  62
  63 /**
  64  * struct binder_lru_page - page object used for binder shrinker
  65  * @page_ptr: pointer to physical page in mmap'd space
  66  * @lru:      entry in binder_alloc_lru
  67  * @alloc:    binder_alloc for a proc
  68  */
  69 struct binder_lru_page {
  70         struct list_head lru;
  71         struct page *page_ptr;
  72         struct binder_alloc *alloc;
  73 };
  74
  75 /**
  76  * struct binder_alloc - per-binder proc state for binder allocator
  77  * @vma:                vm_area_struct passed to mmap_handler
  78  *                      (invarient after mmap)
  79  * @tsk:                tid for task that called init for this proc
  80  *                      (invariant after init)
  81  * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
  82  * @buffer:             base of per-proc address space mapped via mmap
  83  * @buffers:            list of all buffers for this proc
  84  * @free_buffers:       rb tree of buffers available for allocation
  85  *                      sorted by size
  86  * @allocated_buffers:  rb tree of allocated buffers sorted by address
  87  * @free_async_space:   VA space available for async buffers. This is
  88  *                      initialized at mmap time to 1/2 the full VA space
  89  * @pages:              array of binder_lru_page
  90  * @buffer_size:        size of address space specified via mmap
  91  * @pid:                pid for associated binder_proc (invariant after init)
  92  * @pages_high:         high watermark of offset in @pages
  93  * @oneway_spam_detected: %true if oneway spam detection fired, clear that
  94  * flag once the async buffer has returned to a healthy state
  95  *
  96  * Bookkeeping structure for per-proc address space management for binder
  97  * buffers. It is normally initialized during binder_init() and binder_mmap()
  98  * calls. The address space is used for both user-visible buffers and for
  99  * struct binder_buffer objects used to track the user buffers
 100  */
 101 struct binder_alloc {
 102         struct mutex mutex;
 103         struct vm_area_struct *vma;
 104         struct mm_struct *vma_vm_mm;
 105         void __user *buffer;
 106         struct list_head buffers;
 107         struct rb_root free_buffers;
 108         struct rb_root allocated_buffers;
 109         size_t free_async_space;
 110         struct binder_lru_page *pages;
 111         size_t buffer_size;
 112         uint32_t buffer_free;
 113         int pid;
 114         size_t pages_high;
 115         bool oneway_spam_detected;
 116 };
 117
 118 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
 119 void binder_selftest_alloc(struct binder_alloc *alloc);
 120 #else
 121 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 122 #endif
 123 enum lru_status binder_alloc_free_page(struct list_head *item,
 124                                        struct list_lru_one *lru,
 125                                        spinlock_t *lock, void *cb_arg);
 126 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 127                                                   size_t data_size,
 128                                                   size_t offsets_size,
 129                                                   size_t extra_buffers_size,
 130                                                   int is_async,
 131                                                   int pid);
 132 extern void binder_alloc_init(struct binder_alloc *alloc);
 133 extern int binder_alloc_shrinker_init(void);
 134 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 135 extern struct binder_buffer *
 136 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 137                              uintptr_t user_ptr);
 138 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 139                                   struct binder_buffer *buffer);
 140 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 141                                      struct vm_area_struct *vma);
 142 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 143 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 144 extern void binder_alloc_print_allocated(struct seq_file *m,
 145                                          struct binder_alloc *alloc);
 146 void binder_alloc_print_pages(struct seq_file *m,
 147                               struct binder_alloc *alloc);
 148
 149 /**
 150  * binder_alloc_get_free_async_space() - get free space available for async
 151  * @alloc:      binder_alloc for this proc
 152  *
 153  * Return:      the bytes remaining in the address-space for async transactions
 154  */
 155 static inline size_t
 156 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
 157 {
 158         size_t free_async_space;
 159
 160         mutex_lock(&alloc->mutex);
 161         free_async_space = alloc->free_async_space;
 162         mutex_unlock(&alloc->mutex);
 163         return free_async_space;
 164 }
 165
 166 unsigned long
 167 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
 168                                  struct binder_buffer *buffer,
 169                                  binder_size_t buffer_offset,
 170                                  const void __user *from,
 171                                  size_t bytes);
 172
 173 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
 174                                 struct binder_buffer *buffer,
 175                                 binder_size_t buffer_offset,
 176                                 void *src,
 177                                 size_t bytes);
 178
 179 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
 180                                   void *dest,
 181                                   struct binder_buffer *buffer,
 182                                   binder_size_t buffer_offset,
 183                                   size_t bytes);
 184
 185 #endif /* _LINUX_BINDER_ALLOC_H */
 186