LXR linux/drivers/android/binder

   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
  18extern struct list_lru binder_alloc_lru;
  19struct 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 */
  42struct 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 */
  69struct 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 */
 101struct 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
 119void binder_selftest_alloc(struct binder_alloc *alloc);
 120#else
 121static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 122#endif
 123enum lru_status binder_alloc_free_page(struct list_head *item,
 124                                       struct list_lru_one *lru,
 125                                       spinlock_t *lock, void *cb_arg);
 126extern 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);
 132extern void binder_alloc_init(struct binder_alloc *alloc);
 133extern int binder_alloc_shrinker_init(void);
 134extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 135extern struct binder_buffer *
 136binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 137                             uintptr_t user_ptr);
 138extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 139                                  struct binder_buffer *buffer);
 140extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 141                                     struct vm_area_struct *vma);
 142extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 143extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 144extern void binder_alloc_print_allocated(struct seq_file *m,
 145                                         struct binder_alloc *alloc);
 146void 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 */
 155static inline size_t
 156binder_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
 166unsigned long
 167binder_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
 173int 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
 179int 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
 187