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