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_freelist;
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 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_shrinker_mdata - binder metadata used to reclaim pages
63 * @lru: LRU entry in binder_freelist
64 * @alloc: binder_alloc owning the page to reclaim
65 * @page_index: offset in @alloc->pages[] into the page to reclaim
66 */
67struct binder_shrinker_mdata {
68 struct list_head lru;
69 struct binder_alloc *alloc;
70 unsigned long page_index;
71};
72
73static inline struct list_head *page_to_lru(struct page *p)
74{
75 struct binder_shrinker_mdata *mdata;
76
77 mdata = (struct binder_shrinker_mdata *)page_private(p);
78
79 return &mdata->lru;
80}
81
82/**
83 * struct binder_alloc - per-binder proc state for binder allocator
84 * @mutex: protects binder_alloc fields
85 * @mm: copy of task->mm (invariant after open)
86 * @vm_start: base of per-proc address space mapped via mmap
87 * @buffers: list of all buffers for this proc
88 * @free_buffers: rb tree of buffers available for allocation
89 * sorted by size
90 * @allocated_buffers: rb tree of allocated buffers sorted by address
91 * @free_async_space: VA space available for async buffers. This is
92 * initialized at mmap time to 1/2 the full VA space
93 * @pages: array of struct page *
94 * @buffer_size: size of address space specified via mmap
95 * @pid: pid for associated binder_proc (invariant after init)
96 * @pages_high: high watermark of offset in @pages
97 * @mapped: whether the vm area is mapped, each binder instance is
98 * allowed a single mapping throughout its lifetime
99 * @oneway_spam_detected: %true if oneway spam detection fired, clear that
100 * flag once the async buffer has returned to a healthy state
101 *
102 * Bookkeeping structure for per-proc address space management for binder
103 * buffers. It is normally initialized during binder_init() and binder_mmap()
104 * calls. The address space is used for both user-visible buffers and for
105 * struct binder_buffer objects used to track the user buffers
106 */
107struct binder_alloc {
108 struct mutex mutex;
109 struct mm_struct *mm;
110 unsigned long vm_start;
111 struct list_head buffers;
112 struct rb_root free_buffers;
113 struct rb_root allocated_buffers;
114 size_t free_async_space;
115 struct page **pages;
116 size_t buffer_size;
117 int pid;
118 size_t pages_high;
119 bool mapped;
120 bool oneway_spam_detected;
121};
122
123#ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
124void binder_selftest_alloc(struct binder_alloc *alloc);
125#else
126static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
127#endif
128enum lru_status binder_alloc_free_page(struct list_head *item,
129 struct list_lru_one *lru,
130 void *cb_arg);
131struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
132 size_t data_size,
133 size_t offsets_size,
134 size_t extra_buffers_size,
135 int is_async);
136void binder_alloc_init(struct binder_alloc *alloc);
137int binder_alloc_shrinker_init(void);
138void binder_alloc_shrinker_exit(void);
139void binder_alloc_vma_close(struct binder_alloc *alloc);
140struct binder_buffer *
141binder_alloc_prepare_to_free(struct binder_alloc *alloc,
142 unsigned long user_ptr);
143void binder_alloc_free_buf(struct binder_alloc *alloc,
144 struct binder_buffer *buffer);
145int binder_alloc_mmap_handler(struct binder_alloc *alloc,
146 struct vm_area_struct *vma);
147void binder_alloc_deferred_release(struct binder_alloc *alloc);
148int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
149void binder_alloc_print_allocated(struct seq_file *m,
150 struct binder_alloc *alloc);
151void binder_alloc_print_pages(struct seq_file *m,
152 struct binder_alloc *alloc);
153
154/**
155 * binder_alloc_get_free_async_space() - get free space available for async
156 * @alloc: binder_alloc for this proc
157 *
158 * Return: the bytes remaining in the address-space for async transactions
159 */
160static inline size_t
161binder_alloc_get_free_async_space(struct binder_alloc *alloc)
162{
163 size_t free_async_space;
164
165 mutex_lock(&alloc->mutex);
166 free_async_space = alloc->free_async_space;
167 mutex_unlock(lock: &alloc->mutex);
168 return free_async_space;
169}
170
171unsigned long
172binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
173 struct binder_buffer *buffer,
174 binder_size_t buffer_offset,
175 const void __user *from,
176 size_t bytes);
177
178int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
179 struct binder_buffer *buffer,
180 binder_size_t buffer_offset,
181 void *src,
182 size_t bytes);
183
184int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
185 void *dest,
186 struct binder_buffer *buffer,
187 binder_size_t buffer_offset,
188 size_t bytes);
189
190#endif /* _LINUX_BINDER_ALLOC_H */
191
192

source code of linux/drivers/android/binder_alloc.h