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
binder_selftest_alloc(struct binder_alloc * alloc)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 spinlock_t *lock, 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
binder_alloc_get_free_async_space(struct binder_alloc * alloc)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
183