linux-imx

/* binder.c

 *

 * Android IPC Subsystem

 *

 * Copyright (C) 2007-2008 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

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */

​

/*

 * Locking overview

 *

 * There are 3 main spinlocks which must be acquired in the

 * order shown:

 *

 * 1) proc->outer_lock : protects binder_ref

 *    binder_proc_lock() and binder_proc_unlock() are

 *    used to acq/rel.

 * 2) node->lock : protects most fields of binder_node.

 *    binder_node_lock() and binder_node_unlock() are

 *    used to acq/rel

 * 3) proc->inner_lock : protects the thread and node lists

 *    (proc->threads, proc->waiting_threads, proc->nodes)

 *    and all todo lists associated with the binder_proc

 *    (proc->todo, thread->todo, proc->delivered_death and

 *    node->async_todo), as well as thread->transaction_stack

 *    binder_inner_proc_lock() and binder_inner_proc_unlock()

 *    are used to acq/rel

 *

 * Any lock under procA must never be nested under any lock at the same

 * level or below on procB.

 *

 * Functions that require a lock held on entry indicate which lock

 * in the suffix of the function name:

 *

 * foo_olocked() : requires node->outer_lock

 * foo_nlocked() : requires node->lock

 * foo_ilocked() : requires proc->inner_lock

 * foo_oilocked(): requires proc->outer_lock and proc->inner_lock

 * foo_nilocked(): requires node->lock and proc->inner_lock

 * ...

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/fdtable.h>

#include <linux/file.h>

#include <linux/freezer.h>

#include <linux/fs.h>

#include <linux/list.h>

#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/nsproxy.h>

#include <linux/poll.h>

#include <linux/debugfs.h>

#include <linux/rbtree.h>

#include <linux/sched/signal.h>

#include <linux/sched/mm.h>

#include <linux/seq_file.h>

#include <linux/uaccess.h>

#include <linux/pid_namespace.h>

#include <linux/security.h>

#include <linux/spinlock.h>

#include <linux/ratelimit.h>

#include <linux/syscalls.h>

#include <linux/task_work.h>

​

#include <uapi/linux/android/binder.h>

​

#include <asm/cacheflush.h>

​

#include "binder_alloc.h"

#include "binder_internal.h"

#include "binder_trace.h"

​

static HLIST_HEAD(binder_deferred_list);

static DEFINE_MUTEX(binder_deferred_lock);

​

static HLIST_HEAD(binder_devices);

static HLIST_HEAD(binder_procs);

static DEFINE_MUTEX(binder_procs_lock);

​

static HLIST_HEAD(binder_dead_nodes);