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
18extern struct list_lru binder_alloc_lru;
19struct 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 */
42struct 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 */
69struct 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 */
100struct 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
117void binder_selftest_alloc(struct binder_alloc *alloc);
118#else
119static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
120#endif
121enum lru_status binder_alloc_free_page(struct list_head *item,
122				       struct list_lru_one *lru,
123				       spinlock_t *lock, void *cb_arg);
124extern 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);
130extern void binder_alloc_init(struct binder_alloc *alloc);
131extern int binder_alloc_shrinker_init(void);
132extern void binder_alloc_shrinker_exit(void);
133extern void binder_alloc_vma_close(struct binder_alloc *alloc);
134extern struct binder_buffer *
135binder_alloc_prepare_to_free(struct binder_alloc *alloc,
136			     uintptr_t user_ptr);
137extern void binder_alloc_free_buf(struct binder_alloc *alloc,
138				  struct binder_buffer *buffer);
139extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
140				     struct vm_area_struct *vma);
141extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
142extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
143extern void binder_alloc_print_allocated(struct seq_file *m,
144					 struct binder_alloc *alloc);
145void 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 */
154static inline size_t
155binder_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
165unsigned long
166binder_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
172int 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
178int 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