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/spinlock.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_freelist;
  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         struct binder_transaction *transaction;
  53         struct binder_node *target_node;
  54         size_t data_size;
  55         size_t offsets_size;
  56         size_t extra_buffers_size;
  57         unsigned long user_data;
  58         int pid;
  59 };
  60
  61 /**
  62  * struct binder_lru_page - page object used for binder shrinker
  63  * @page_ptr: pointer to physical page in mmap'd space
  64  * @lru:      entry in binder_freelist
  65  * @alloc:    binder_alloc for a proc
  66  */
  67 struct binder_lru_page {
  68         struct list_head lru;
  69         struct page *page_ptr;
  70         struct binder_alloc *alloc;
  71 };
  72
  73 /**
  74  * struct binder_alloc - per-binder proc state for binder allocator
  75  * @lock:               protects binder_alloc fields
  76  * @vma:                vm_area_struct passed to mmap_handler
  77  *                      (invariant after mmap)
  78  * @mm:                 copy of task->mm (invariant after open)
  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  * @oneway_spam_detected: %true if oneway spam detection fired, clear that
  91  * flag once the async buffer has returned to a healthy state
  92  *
  93  * Bookkeeping structure for per-proc address space management for binder
  94  * buffers. It is normally initialized during binder_init() and binder_mmap()
  95  * calls. The address space is used for both user-visible buffers and for
  96  * struct binder_buffer objects used to track the user buffers
  97  */
  98 struct binder_alloc {
  99         spinlock_t lock;
 100         struct vm_area_struct *vma;
 101         struct mm_struct *mm;
 102         unsigned long buffer;
 103         struct list_head buffers;
 104         struct rb_root free_buffers;
 105         struct rb_root allocated_buffers;
 106         size_t free_async_space;
 107         struct binder_lru_page *pages;
 108         size_t buffer_size;
 109         int pid;
 110         size_t pages_high;
 111         bool oneway_spam_detected;
 112 };
 113
 114 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
 115 void binder_selftest_alloc(struct binder_alloc *alloc);
 116 #else
 117 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 118 #endif
 119 enum lru_status binder_alloc_free_page(struct list_head *item,
 120                                        struct list_lru_one *lru,
 121                                        void *cb_arg);
 122 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 123                                            size_t data_size,
 124                                            size_t offsets_size,
 125                                            size_t extra_buffers_size,
 126                                            int is_async);
 127 void binder_alloc_init(struct binder_alloc *alloc);
 128 int binder_alloc_shrinker_init(void);
 129 void binder_alloc_shrinker_exit(void);
 130 void binder_alloc_vma_close(struct binder_alloc *alloc);
 131 struct binder_buffer *
 132 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 133                              unsigned long user_ptr);
 134 void binder_alloc_free_buf(struct binder_alloc *alloc,
 135                            struct binder_buffer *buffer);
 136 int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 137                               struct vm_area_struct *vma);
 138 void binder_alloc_deferred_release(struct binder_alloc *alloc);
 139 int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 140 void binder_alloc_print_allocated(struct seq_file *m,
 141                                   struct binder_alloc *alloc);
 142 void binder_alloc_print_pages(struct seq_file *m,
 143                               struct binder_alloc *alloc);
 144
 145 /**
 146  * binder_alloc_get_free_async_space() - get free space available for async
 147  * @alloc:      binder_alloc for this proc
 148  *
 149  * Return:      the bytes remaining in the address-space for async transactions
 150  */
 151 static inline size_t
 152 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
 153 {
 154         size_t free_async_space;
 155
 156         spin_lock(&alloc->lock);
 157         free_async_space = alloc->free_async_space;
 158         spin_unlock(&alloc->lock);
 159         return free_async_space;
 160 }
 161
 162 unsigned long
 163 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
 164                                  struct binder_buffer *buffer,
 165                                  binder_size_t buffer_offset,
 166                                  const void __user *from,
 167                                  size_t bytes);
 168
 169 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
 170                                 struct binder_buffer *buffer,
 171                                 binder_size_t buffer_offset,
 172                                 void *src,
 173                                 size_t bytes);
 174
 175 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
 176                                   void *dest,
 177                                   struct binder_buffer *buffer,
 178                                   binder_size_t buffer_offset,
 179                                   size_t bytes);
 180
 181 #endif /* _LINUX_BINDER_ALLOC_H */
 182