projects/linux·blob uaccess-cleanups · refs

189 lines · 6.5 KiB

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
18struct binder_transaction;
19
20/**
21 * struct binder_buffer - buffer used for binder transactions
22 * @entry: entry alloc->buffers
23 * @rb_node: node for allocated_buffers/free_buffers rb trees
24 * @free: %true if buffer is free
25 * @clear_on_free: %true if buffer must be zeroed after use
26 * @allow_user_free: %true if user is allowed to free buffer
27 * @async_transaction: %true if buffer is in use for an async txn
28 * @oneway_spam_suspect: %true if total async allocate size just exceed
29 * spamming detect threshold
30 * @debug_id: unique ID for debugging
31 * @transaction: pointer to associated struct binder_transaction
32 * @target_node: struct binder_node associated with this buffer
33 * @data_size: size of @transaction data
34 * @offsets_size: size of array of offsets
35 * @extra_buffers_size: size of space for other objects (like sg lists)
36 * @user_data: user pointer to base of buffer space
37 * @pid: pid to attribute the buffer to (caller)
38 *
39 * Bookkeeping structure for binder transaction buffers
40 */
41struct binder_buffer {
42 struct list_head entry; /* free and allocated entries by address */
43 struct rb_node rb_node; /* free entry by size or allocated entry */
44 /* by address */
45 unsigned free:1;
46 unsigned clear_on_free:1;
47 unsigned allow_user_free:1;
48 unsigned async_transaction:1;
49 unsigned oneway_spam_suspect:1;
50 unsigned debug_id:27;
51 struct binder_transaction *transaction;
52 struct binder_node *target_node;
53 size_t data_size;
54 size_t offsets_size;
55 size_t extra_buffers_size;
56 unsigned long user_data;
57 int pid;
58};
59
60/**
61 * struct binder_shrinker_mdata - binder metadata used to reclaim pages
62 * @lru: LRU entry in binder_freelist
63 * @alloc: binder_alloc owning the page to reclaim
64 * @page_index: offset in @alloc->pages[] into the page to reclaim
65 */
66struct binder_shrinker_mdata {
67 struct list_head lru;
68 struct binder_alloc *alloc;
69 unsigned long page_index;
70};
71
72static inline struct list_head *page_to_lru(struct page *p)
73{
74 struct binder_shrinker_mdata *mdata;
75
76 mdata = (struct binder_shrinker_mdata *)page_private(p);
77
78 return &mdata->lru;
79}
80
81/**
82 * struct binder_alloc - per-binder proc state for binder allocator
83 * @mutex: protects binder_alloc fields
84 * @mm: copy of task->mm (invariant after open)
85 * @vm_start: base of per-proc address space mapped via mmap
86 * @buffers: list of all buffers for this proc
87 * @free_buffers: rb tree of buffers available for allocation
88 * sorted by size
89 * @allocated_buffers: rb tree of allocated buffers sorted by address
90 * @free_async_space: VA space available for async buffers. This is
91 * initialized at mmap time to 1/2 the full VA space
92 * @pages: array of struct page *
93 * @freelist: lru list to use for free pages (invariant after init)
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 struct list_lru *freelist;
117 size_t buffer_size;
118 int pid;
119 size_t pages_high;
120 bool mapped;
121 bool oneway_spam_detected;
122};
123
124enum lru_status binder_alloc_free_page(struct list_head *item,
125 struct list_lru_one *lru,
126 void *cb_arg);
127struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
128 size_t data_size,
129 size_t offsets_size,
130 size_t extra_buffers_size,
131 int is_async);
132void binder_alloc_init(struct binder_alloc *alloc);
133int binder_alloc_shrinker_init(void);
134void binder_alloc_shrinker_exit(void);
135void binder_alloc_vma_close(struct binder_alloc *alloc);
136struct binder_buffer *
137binder_alloc_prepare_to_free(struct binder_alloc *alloc,
138 unsigned long user_ptr);
139void binder_alloc_free_buf(struct binder_alloc *alloc,
140 struct binder_buffer *buffer);
141int binder_alloc_mmap_handler(struct binder_alloc *alloc,
142 struct vm_area_struct *vma);
143void binder_alloc_deferred_release(struct binder_alloc *alloc);
144int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
145void binder_alloc_print_allocated(struct seq_file *m,
146 struct binder_alloc *alloc);
147void binder_alloc_print_pages(struct seq_file *m,
148 struct binder_alloc *alloc);
149
150/**
151 * binder_alloc_get_free_async_space() - get free space available for async
152 * @alloc: binder_alloc for this proc
153 *
154 * Return: the bytes remaining in the address-space for async transactions
155 */
156static inline size_t
157binder_alloc_get_free_async_space(struct binder_alloc *alloc)
158{
159 guard(mutex)(&alloc->mutex);
160 return alloc->free_async_space;
161}
162
163unsigned long
164binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
165 struct binder_buffer *buffer,
166 binder_size_t buffer_offset,
167 const void __user *from,
168 size_t bytes);
169
170int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
171 struct binder_buffer *buffer,
172 binder_size_t buffer_offset,
173 void *src,
174 size_t bytes);
175
176int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
177 void *dest,
178 struct binder_buffer *buffer,
179 binder_size_t buffer_offset,
180 size_t bytes);
181
182#if IS_ENABLED(CONFIG_KUNIT)
183void __binder_alloc_init(struct binder_alloc *alloc, struct list_lru *freelist);
184size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
185 struct binder_buffer *buffer);
186#endif
187
188#endif /* _LINUX_BINDER_ALLOC_H */
189