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* Copyright (C) 2017 Google, Inc.
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
#include <linux/rbtree.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/rtmutex.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
struct binder_transaction;
* struct binder_buffer - buffer used for binder transactions
* @entry: entry alloc->buffers
* @rb_node: node for allocated_buffers/free_buffers rb trees
* @free: true if buffer is free
* @allow_user_free: describe the second member of struct blah,
* @async_transaction: describe the second member of struct blah,
* @debug_id: describe the second member of struct blah,
* @transaction: describe the second member of struct blah,
* @target_node: describe the second member of struct blah,
* @data_size: describe the second member of struct blah,
* @offsets_size: describe the second member of struct blah,
* @extra_buffers_size: describe the second member of struct blah,
* @data:i describe the second member of struct blah,
* Bookkeeping structure for binder transaction buffers
struct binder_buffer {
struct list_head entry; /* free and allocated entries by address */
struct rb_node rb_node; /* free entry by size or allocated entry */
/* by address */
unsigned free:1;
unsigned allow_user_free:1;
unsigned async_transaction:1;
unsigned free_in_progress:1;
unsigned debug_id:28;
struct binder_transaction *transaction;
struct binder_node *target_node;
size_t data_size;
size_t offsets_size;
size_t extra_buffers_size;
uint8_t data[0];
* struct binder_alloc - per-binder proc state for binder allocator
* @vma: vm_area_struct passed to mmap_handler
* (invarient after mmap)
* @tsk: tid for task that called init for this proc
* (invariant after init)
* @vma_vm_mm: copy of vma->vm_mm (invarient after mmap)
* @buffer: base of per-proc address space mapped via mmap
* @user_buffer_offset: offset between user and kernel VAs for buffer
* @buffers: list of all buffers for this proc
* @free_buffers: rb tree of buffers available for allocation
* sorted by size
* @allocated_buffers: rb tree of allocated buffers sorted by address
* @free_async_space: VA space available for async buffers. This is
* initialized at mmap time to 1/2 the full VA space
* @pages: array of physical page addresses for each
* page of mmap'd space
* @buffer_size: size of address space specified via mmap
* @pid: pid for associated binder_proc (invariant after init)
* Bookkeeping structure for per-proc address space management for binder
* buffers. It is normally initialized during binder_init() and binder_mmap()
* calls. The address space is used for both user-visible buffers and for
* struct binder_buffer objects used to track the user buffers
struct binder_alloc {
struct mutex mutex;
struct task_struct *tsk;
struct vm_area_struct *vma;
struct mm_struct *vma_vm_mm;
void *buffer;
ptrdiff_t user_buffer_offset;
struct list_head buffers;
struct rb_root free_buffers;
struct rb_root allocated_buffers;
size_t free_async_space;
struct page **pages;
size_t buffer_size;
uint32_t buffer_free;
int pid;
void binder_selftest_alloc(struct binder_alloc *alloc);
static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
size_t data_size,
size_t offsets_size,
size_t extra_buffers_size,
int is_async);
extern void binder_alloc_init(struct binder_alloc *alloc);
extern void binder_alloc_vma_close(struct binder_alloc *alloc);
extern struct binder_buffer *
binder_alloc_prepare_to_free(struct binder_alloc *alloc,
uintptr_t user_ptr);
extern void binder_alloc_free_buf(struct binder_alloc *alloc,
struct binder_buffer *buffer);
extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
struct vm_area_struct *vma);
extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
extern void binder_alloc_print_allocated(struct seq_file *m,
struct binder_alloc *alloc);
* binder_alloc_get_free_async_space() - get free space available for async
* @alloc: binder_alloc for this proc
* Return: the bytes remaining in the address-space for async transactions
static inline size_t
binder_alloc_get_free_async_space(struct binder_alloc *alloc)
size_t free_async_space;
free_async_space = alloc->free_async_space;
return free_async_space;
* binder_alloc_get_user_buffer_offset() - get offset between kernel/user addrs
* @alloc: binder_alloc for this proc
* Return: the offset between kernel and user-space addresses to use for
* virtual address conversion
static inline ptrdiff_t
binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc)
* user_buffer_offset is constant if vma is set and
* undefined if vma is not set. It is possible to
* get here with !alloc->vma if the target process
* is dying while a transaction is being initiated.
* Returning the old value is ok in this case and
* the transaction will fail.
return alloc->user_buffer_offset;
#endif /* _LINUX_BINDER_ALLOC_H */