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  * @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  * @debug_id:           unique ID for debugging
29  * @transaction:        pointer to associated struct binder_transaction
30  * @target_node:        struct binder_node associated with this buffer
31  * @data_size:          size of @transaction data
32  * @offsets_size:       size of array of offsets
33  * @extra_buffers_size: size of space for other objects (like sg lists)
34  * @user_data:          user pointer to base of buffer space
35  * @pid:                pid to attribute the buffer to (caller)
36  *
37  * Bookkeeping structure for binder transaction buffers
38  */
39 struct binder_buffer {
40 	struct list_head entry; /* free and allocated entries by address */
41 	struct rb_node rb_node; /* free entry by size or allocated entry */
42 				/* by address */
43 	unsigned free:1;
44 	unsigned allow_user_free:1;
45 	unsigned async_transaction:1;
46 	unsigned debug_id:29;
47 
48 	struct binder_transaction *transaction;
49 
50 	struct binder_node *target_node;
51 	size_t data_size;
52 	size_t offsets_size;
53 	size_t extra_buffers_size;
54 	void __user *user_data;
55 	int    pid;
56 };
57 
58 /**
59  * struct binder_lru_page - page object used for binder shrinker
60  * @page_ptr: pointer to physical page in mmap'd space
61  * @lru:      entry in binder_alloc_lru
62  * @alloc:    binder_alloc for a proc
63  */
64 struct binder_lru_page {
65 	struct list_head lru;
66 	struct page *page_ptr;
67 	struct binder_alloc *alloc;
68 };
69 
70 /**
71  * struct binder_alloc - per-binder proc state for binder allocator
72  * @vma:                vm_area_struct passed to mmap_handler
73  *                      (invarient after mmap)
74  * @tsk:                tid for task that called init for this proc
75  *                      (invariant after init)
76  * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
77  * @buffer:             base of per-proc address space mapped via mmap
78  * @buffers:            list of all buffers for this proc
79  * @free_buffers:       rb tree of buffers available for allocation
80  *                      sorted by size
81  * @allocated_buffers:  rb tree of allocated buffers sorted by address
82  * @free_async_space:   VA space available for async buffers. This is
83  *                      initialized at mmap time to 1/2 the full VA space
84  * @pages:              array of binder_lru_page
85  * @buffer_size:        size of address space specified via mmap
86  * @pid:                pid for associated binder_proc (invariant after init)
87  * @pages_high:         high watermark of offset in @pages
88  *
89  * Bookkeeping structure for per-proc address space management for binder
90  * buffers. It is normally initialized during binder_init() and binder_mmap()
91  * calls. The address space is used for both user-visible buffers and for
92  * struct binder_buffer objects used to track the user buffers
93  */
94 struct binder_alloc {
95 	struct mutex mutex;
96 	struct vm_area_struct *vma;
97 	struct mm_struct *vma_vm_mm;
98 	void __user *buffer;
99 	struct list_head buffers;
100 	struct rb_root free_buffers;
101 	struct rb_root allocated_buffers;
102 	size_t free_async_space;
103 	struct binder_lru_page *pages;
104 	size_t buffer_size;
105 	uint32_t buffer_free;
106 	int pid;
107 	size_t pages_high;
108 };
109 
110 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
111 void binder_selftest_alloc(struct binder_alloc *alloc);
112 #else
113 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
114 #endif
115 enum lru_status binder_alloc_free_page(struct list_head *item,
116 				       struct list_lru_one *lru,
117 				       spinlock_t *lock, void *cb_arg);
118 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
119 						  size_t data_size,
120 						  size_t offsets_size,
121 						  size_t extra_buffers_size,
122 						  int is_async,
123 						  int pid);
124 extern void binder_alloc_init(struct binder_alloc *alloc);
125 extern int binder_alloc_shrinker_init(void);
126 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
127 extern struct binder_buffer *
128 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
129 			     uintptr_t user_ptr);
130 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
131 				  struct binder_buffer *buffer);
132 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
133 				     struct vm_area_struct *vma);
134 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
135 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
136 extern void binder_alloc_print_allocated(struct seq_file *m,
137 					 struct binder_alloc *alloc);
138 void binder_alloc_print_pages(struct seq_file *m,
139 			      struct binder_alloc *alloc);
140 
141 /**
142  * binder_alloc_get_free_async_space() - get free space available for async
143  * @alloc:	binder_alloc for this proc
144  *
145  * Return:	the bytes remaining in the address-space for async transactions
146  */
147 static inline size_t
148 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
149 {
150 	size_t free_async_space;
151 
152 	mutex_lock(&alloc->mutex);
153 	free_async_space = alloc->free_async_space;
154 	mutex_unlock(&alloc->mutex);
155 	return free_async_space;
156 }
157 
158 unsigned long
159 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
160 				 struct binder_buffer *buffer,
161 				 binder_size_t buffer_offset,
162 				 const void __user *from,
163 				 size_t bytes);
164 
165 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
166 				struct binder_buffer *buffer,
167 				binder_size_t buffer_offset,
168 				void *src,
169 				size_t bytes);
170 
171 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
172 				  void *dest,
173 				  struct binder_buffer *buffer,
174 				  binder_size_t buffer_offset,
175 				  size_t bytes);
176 
177 #endif /* _LINUX_BINDER_ALLOC_H */
178 
179