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  * @vma:                vm_area_struct passed to mmap_handler
78  *                      (invarient after mmap)
79  * @tsk:                tid for task that called init for this proc
80  *                      (invariant after init)
81  * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
82  * @buffer:             base of per-proc address space mapped via mmap
83  * @buffers:            list of all buffers for this proc
84  * @free_buffers:       rb tree of buffers available for allocation
85  *                      sorted by size
86  * @allocated_buffers:  rb tree of allocated buffers sorted by address
87  * @free_async_space:   VA space available for async buffers. This is
88  *                      initialized at mmap time to 1/2 the full VA space
89  * @pages:              array of binder_lru_page
90  * @buffer_size:        size of address space specified via mmap
91  * @pid:                pid for associated binder_proc (invariant after init)
92  * @pages_high:         high watermark of offset in @pages
93  * @oneway_spam_detected: %true if oneway spam detection fired, clear that
94  * flag once the async buffer has returned to a healthy state
95  *
96  * Bookkeeping structure for per-proc address space management for binder
97  * buffers. It is normally initialized during binder_init() and binder_mmap()
98  * calls. The address space is used for both user-visible buffers and for
99  * struct binder_buffer objects used to track the user buffers
100  */
101 struct binder_alloc {
102 	struct mutex mutex;
103 	struct vm_area_struct *vma;
104 	struct mm_struct *vma_vm_mm;
105 	void __user *buffer;
106 	struct list_head buffers;
107 	struct rb_root free_buffers;
108 	struct rb_root allocated_buffers;
109 	size_t free_async_space;
110 	struct binder_lru_page *pages;
111 	size_t buffer_size;
112 	uint32_t buffer_free;
113 	int pid;
114 	size_t pages_high;
115 	bool oneway_spam_detected;
116 };
117 
118 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
119 void binder_selftest_alloc(struct binder_alloc *alloc);
120 #else
121 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
122 #endif
123 enum lru_status binder_alloc_free_page(struct list_head *item,
124 				       struct list_lru_one *lru,
125 				       spinlock_t *lock, void *cb_arg);
126 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
127 						  size_t data_size,
128 						  size_t offsets_size,
129 						  size_t extra_buffers_size,
130 						  int is_async,
131 						  int pid);
132 extern void binder_alloc_init(struct binder_alloc *alloc);
133 extern int binder_alloc_shrinker_init(void);
134 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
135 extern struct binder_buffer *
136 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
137 			     uintptr_t user_ptr);
138 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
139 				  struct binder_buffer *buffer);
140 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
141 				     struct vm_area_struct *vma);
142 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
143 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
144 extern void binder_alloc_print_allocated(struct seq_file *m,
145 					 struct binder_alloc *alloc);
146 void binder_alloc_print_pages(struct seq_file *m,
147 			      struct binder_alloc *alloc);
148 
149 /**
150  * binder_alloc_get_free_async_space() - get free space available for async
151  * @alloc:	binder_alloc for this proc
152  *
153  * Return:	the bytes remaining in the address-space for async transactions
154  */
155 static inline size_t
156 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
157 {
158 	size_t free_async_space;
159 
160 	mutex_lock(&alloc->mutex);
161 	free_async_space = alloc->free_async_space;
162 	mutex_unlock(&alloc->mutex);
163 	return free_async_space;
164 }
165 
166 unsigned long
167 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
168 				 struct binder_buffer *buffer,
169 				 binder_size_t buffer_offset,
170 				 const void __user *from,
171 				 size_t bytes);
172 
173 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
174 				struct binder_buffer *buffer,
175 				binder_size_t buffer_offset,
176 				void *src,
177 				size_t bytes);
178 
179 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
180 				  void *dest,
181 				  struct binder_buffer *buffer,
182 				  binder_size_t buffer_offset,
183 				  size_t bytes);
184 
185 #endif /* _LINUX_BINDER_ALLOC_H */
186 
187