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32 results

iomap_32.c

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  • binder.c 106.48 KiB
    /* 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.
     *
     */
    
    #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
    
    #include <asm/cacheflush.h>
    #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/mm.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.h>
    #include <linux/seq_file.h>
    #include <linux/uaccess.h>
    #include <linux/vmalloc.h>
    #include <linux/slab.h>
    #include <linux/pid_namespace.h>
    #include <linux/security.h>
    
    #ifdef CONFIG_ANDROID_BINDER_IPC_32BIT
    #define BINDER_IPC_32BIT 1
    #endif
    
    #include <uapi/linux/android/binder.h>
    #include "binder_trace.h"
    
    static DEFINE_MUTEX(binder_main_lock);
    static DEFINE_MUTEX(binder_deferred_lock);
    static DEFINE_MUTEX(binder_mmap_lock);
    
    static HLIST_HEAD(binder_devices);
    static HLIST_HEAD(binder_procs);
    static HLIST_HEAD(binder_deferred_list);
    static HLIST_HEAD(binder_dead_nodes);
    
    static struct dentry *binder_debugfs_dir_entry_root;
    static struct dentry *binder_debugfs_dir_entry_proc;
    static int binder_last_id;
    
    #define BINDER_DEBUG_ENTRY(name) \
    static int binder_##name##_open(struct inode *inode, struct file *file) \
    { \
    	return single_open(file, binder_##name##_show, inode->i_private); \
    } \
    \
    static const struct file_operations binder_##name##_fops = { \
    	.owner = THIS_MODULE, \
    	.open = binder_##name##_open, \
    	.read = seq_read, \
    	.llseek = seq_lseek, \
    	.release = single_release, \
    }
    
    static int binder_proc_show(struct seq_file *m, void *unused);
    BINDER_DEBUG_ENTRY(proc);
    
    /* This is only defined in include/asm-arm/sizes.h */
    #ifndef SZ_1K
    #define SZ_1K                               0x400
    #endif
    
    #ifndef SZ_4M
    #define SZ_4M                               0x400000
    #endif
    
    #define FORBIDDEN_MMAP_FLAGS                (VM_WRITE)
    
    #define BINDER_SMALL_BUF_SIZE (PAGE_SIZE * 64)
    
    enum {
    	BINDER_DEBUG_USER_ERROR             = 1U << 0,
    	BINDER_DEBUG_FAILED_TRANSACTION     = 1U << 1,
    	BINDER_DEBUG_DEAD_TRANSACTION       = 1U << 2,
    	BINDER_DEBUG_OPEN_CLOSE             = 1U << 3,
    	BINDER_DEBUG_DEAD_BINDER            = 1U << 4,
    	BINDER_DEBUG_DEATH_NOTIFICATION     = 1U << 5,
    	BINDER_DEBUG_READ_WRITE             = 1U << 6,
    	BINDER_DEBUG_USER_REFS              = 1U << 7,
    	BINDER_DEBUG_THREADS                = 1U << 8,
    	BINDER_DEBUG_TRANSACTION            = 1U << 9,
    	BINDER_DEBUG_TRANSACTION_COMPLETE   = 1U << 10,
    	BINDER_DEBUG_FREE_BUFFER            = 1U << 11,
    	BINDER_DEBUG_INTERNAL_REFS          = 1U << 12,
    	BINDER_DEBUG_BUFFER_ALLOC           = 1U << 13,
    	BINDER_DEBUG_PRIORITY_CAP           = 1U << 14,
    	BINDER_DEBUG_BUFFER_ALLOC_ASYNC     = 1U << 15,
    };
    static uint32_t binder_debug_mask = BINDER_DEBUG_USER_ERROR |
    	BINDER_DEBUG_FAILED_TRANSACTION | BINDER_DEBUG_DEAD_TRANSACTION;
    module_param_named(debug_mask, binder_debug_mask, uint, S_IWUSR | S_IRUGO);
    
    static bool binder_debug_no_lock;
    module_param_named(proc_no_lock, binder_debug_no_lock, bool, S_IWUSR | S_IRUGO);
    
    static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
    module_param_named(devices, binder_devices_param, charp, 0444);
    
    static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait);
    static int binder_stop_on_user_error;
    
    static int binder_set_stop_on_user_error(const char *val,
    					 struct kernel_param *kp)
    {
    	int ret;
    
    	ret = param_set_int(val, kp);
    	if (binder_stop_on_user_error < 2)
    		wake_up(&binder_user_error_wait);
    	return ret;
    }
    module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
    	param_get_int, &binder_stop_on_user_error, S_IWUSR | S_IRUGO);
    
    #define binder_debug(mask, x...) \
    	do { \
    		if (binder_debug_mask & mask) \
    			pr_info(x); \
    	} while (0)
    
    #define binder_user_error(x...) \
    	do { \
    		if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) \
    			pr_info(x); \
    		if (binder_stop_on_user_error) \
    			binder_stop_on_user_error = 2; \
    	} while (0)
    
    #define to_flat_binder_object(hdr) \
    	container_of(hdr, struct flat_binder_object, hdr)
    
    #define to_binder_fd_object(hdr) container_of(hdr, struct binder_fd_object, hdr)
    
    enum binder_stat_types {
    	BINDER_STAT_PROC,
    	BINDER_STAT_THREAD,
    	BINDER_STAT_NODE,
    	BINDER_STAT_REF,
    	BINDER_STAT_DEATH,
    	BINDER_STAT_TRANSACTION,
    	BINDER_STAT_TRANSACTION_COMPLETE,
    	BINDER_STAT_COUNT
    };
    
    struct binder_stats {
    	int br[_IOC_NR(BR_FAILED_REPLY) + 1];
    	int bc[_IOC_NR(BC_DEAD_BINDER_DONE) + 1];
    	int obj_created[BINDER_STAT_COUNT];
    	int obj_deleted[BINDER_STAT_COUNT];
    };
    
    static struct binder_stats binder_stats;
    
    static inline void binder_stats_deleted(enum binder_stat_types type)
    {
    	binder_stats.obj_deleted[type]++;
    }
    
    static inline void binder_stats_created(enum binder_stat_types type)
    {
    	binder_stats.obj_created[type]++;
    }
    
    struct binder_transaction_log_entry {
    	int debug_id;
    	int call_type;
    	int from_proc;
    	int from_thread;
    	int target_handle;
    	int to_proc;
    	int to_thread;
    	int to_node;
    	int data_size;
    	int offsets_size;
    	const char *context_name;
    };
    struct binder_transaction_log {
    	int next;
    	int full;
    	struct binder_transaction_log_entry entry[32];
    };
    static struct binder_transaction_log binder_transaction_log;
    static struct binder_transaction_log binder_transaction_log_failed;
    
    static struct binder_transaction_log_entry *binder_transaction_log_add(
    	struct binder_transaction_log *log)
    {
    	struct binder_transaction_log_entry *e;
    
    	e = &log->entry[log->next];
    	memset(e, 0, sizeof(*e));
    	log->next++;
    	if (log->next == ARRAY_SIZE(log->entry)) {
    		log->next = 0;
    		log->full = 1;
    	}
    	return e;
    }
    
    struct binder_context {
    	struct binder_node *binder_context_mgr_node;
    	kuid_t binder_context_mgr_uid;
    	const char *name;
    };
    
    struct binder_device {
    	struct hlist_node hlist;
    	struct miscdevice miscdev;
    	struct binder_context context;
    };
    
    struct binder_work {
    	struct list_head entry;
    	enum {
    		BINDER_WORK_TRANSACTION = 1,
    		BINDER_WORK_TRANSACTION_COMPLETE,
    		BINDER_WORK_NODE,
    		BINDER_WORK_DEAD_BINDER,
    		BINDER_WORK_DEAD_BINDER_AND_CLEAR,
    		BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
    	} type;
    };
    
    struct binder_node {
    	int debug_id;
    	struct binder_work work;
    	union {
    		struct rb_node rb_node;
    		struct hlist_node dead_node;
    	};
    	struct binder_proc *proc;
    	struct hlist_head refs;
    	int internal_strong_refs;
    	int local_weak_refs;
    	int local_strong_refs;
    	binder_uintptr_t ptr;
    	binder_uintptr_t cookie;
    	unsigned has_strong_ref:1;
    	unsigned pending_strong_ref:1;
    	unsigned has_weak_ref:1;
    	unsigned pending_weak_ref:1;
    	unsigned has_async_transaction:1;
    	unsigned accept_fds:1;
    	unsigned min_priority:8;
    	struct list_head async_todo;
    };
    
    struct binder_ref_death {
    	struct binder_work work;
    	binder_uintptr_t cookie;
    };
    
    struct binder_ref {
    	/* Lookups needed: */
    	/*   node + proc => ref (transaction) */
    	/*   desc + proc => ref (transaction, inc/dec ref) */
    	/*   node => refs + procs (proc exit) */
    	int debug_id;
    	struct rb_node rb_node_desc;
    	struct rb_node rb_node_node;
    	struct hlist_node node_entry;
    	struct binder_proc *proc;
    	struct binder_node *node;
    	uint32_t desc;
    	int strong;
    	int weak;
    	struct binder_ref_death *death;
    };
    
    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 debug_id:29;
    
    	struct binder_transaction *transaction;
    
    	struct binder_node *target_node;
    	size_t data_size;
    	size_t offsets_size;
    	uint8_t data[0];
    };
    
    enum binder_deferred_state {
    	BINDER_DEFERRED_PUT_FILES    = 0x01,
    	BINDER_DEFERRED_FLUSH        = 0x02,
    	BINDER_DEFERRED_RELEASE      = 0x04,
    };
    
    struct binder_proc {
    	struct hlist_node proc_node;
    	struct rb_root threads;
    	struct rb_root nodes;
    	struct rb_root refs_by_desc;
    	struct rb_root refs_by_node;
    	int pid;
    	struct vm_area_struct *vma;
    	struct mm_struct *vma_vm_mm;
    	struct task_struct *tsk;
    	struct files_struct *files;
    	struct hlist_node deferred_work_node;
    	int deferred_work;
    	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;
    	struct list_head todo;
    	wait_queue_head_t wait;
    	struct binder_stats stats;
    	struct list_head delivered_death;
    	int max_threads;
    	int requested_threads;
    	int requested_threads_started;
    	int ready_threads;
    	long default_priority;
    	struct dentry *debugfs_entry;
    	struct binder_context *context;
    };
    
    enum {
    	BINDER_LOOPER_STATE_REGISTERED  = 0x01,
    	BINDER_LOOPER_STATE_ENTERED     = 0x02,
    	BINDER_LOOPER_STATE_EXITED      = 0x04,
    	BINDER_LOOPER_STATE_INVALID     = 0x08,
    	BINDER_LOOPER_STATE_WAITING     = 0x10,
    	BINDER_LOOPER_STATE_NEED_RETURN = 0x20
    };
    
    struct binder_thread {
    	struct binder_proc *proc;
    	struct rb_node rb_node;
    	int pid;
    	int looper;
    	struct binder_transaction *transaction_stack;
    	struct list_head todo;
    	uint32_t return_error; /* Write failed, return error code in read buf */
    	uint32_t return_error2; /* Write failed, return error code in read */
    		/* buffer. Used when sending a reply to a dead process that */
    		/* we are also waiting on */
    	wait_queue_head_t wait;
    	struct binder_stats stats;
    };
    
    struct binder_transaction {
    	int debug_id;
    	struct binder_work work;
    	struct binder_thread *from;
    	struct binder_transaction *from_parent;
    	struct binder_proc *to_proc;
    	struct binder_thread *to_thread;
    	struct binder_transaction *to_parent;
    	unsigned need_reply:1;
    	/* unsigned is_dead:1; */	/* not used at the moment */
    
    	struct binder_buffer *buffer;
    	unsigned int	code;
    	unsigned int	flags;
    	long	priority;
    	long	saved_priority;
    	kuid_t	sender_euid;
    };
    
    static void
    binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
    
    static int task_get_unused_fd_flags(struct binder_proc *proc, int flags)
    {
    	struct files_struct *files = proc->files;
    	unsigned long rlim_cur;
    	unsigned long irqs;
    
    	if (files == NULL)
    		return -ESRCH;
    
    	if (!lock_task_sighand(proc->tsk, &irqs))
    		return -EMFILE;
    
    	rlim_cur = task_rlimit(proc->tsk, RLIMIT_NOFILE);
    	unlock_task_sighand(proc->tsk, &irqs);
    
    	return __alloc_fd(files, 0, rlim_cur, flags);
    }
    
    /*
     * copied from fd_install
     */
    static void task_fd_install(
    	struct binder_proc *proc, unsigned int fd, struct file *file)
    {
    	if (proc->files)
    		__fd_install(proc->files, fd, file);
    }
    
    /*
     * copied from sys_close
     */
    static long task_close_fd(struct binder_proc *proc, unsigned int fd)
    {
    	int retval;
    
    	if (proc->files == NULL)
    		return -ESRCH;
    
    	retval = __close_fd(proc->files, fd);
    	/* can't restart close syscall because file table entry was cleared */
    	if (unlikely(retval == -ERESTARTSYS ||
    		     retval == -ERESTARTNOINTR ||
    		     retval == -ERESTARTNOHAND ||
    		     retval == -ERESTART_RESTARTBLOCK))
    		retval = -EINTR;
    
    	return retval;
    }
    
    static inline void binder_lock(const char *tag)
    {
    	trace_binder_lock(tag);
    	mutex_lock(&binder_main_lock);
    	trace_binder_locked(tag);
    }
    
    static inline void binder_unlock(const char *tag)
    {
    	trace_binder_unlock(tag);
    	mutex_unlock(&binder_main_lock);
    }
    
    static void binder_set_nice(long nice)
    {
    	long min_nice;
    
    	if (can_nice(current, nice)) {
    		set_user_nice(current, nice);
    		return;
    	}
    	min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur);
    	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
    		     "%d: nice value %ld not allowed use %ld instead\n",
    		      current->pid, nice, min_nice);
    	set_user_nice(current, min_nice);
    	if (min_nice <= MAX_NICE)
    		return;
    	binder_user_error("%d RLIMIT_NICE not set\n", current->pid);
    }
    
    static size_t binder_buffer_size(struct binder_proc *proc,
    				 struct binder_buffer *buffer)
    {
    	if (list_is_last(&buffer->entry, &proc->buffers))
    		return proc->buffer + proc->buffer_size - (void *)buffer->data;
    	return (size_t)list_entry(buffer->entry.next,
    			  struct binder_buffer, entry) - (size_t)buffer->data;
    }
    
    static void binder_insert_free_buffer(struct binder_proc *proc,
    				      struct binder_buffer *new_buffer)
    {
    	struct rb_node **p = &proc->free_buffers.rb_node;
    	struct rb_node *parent = NULL;
    	struct binder_buffer *buffer;
    	size_t buffer_size;
    	size_t new_buffer_size;
    
    	BUG_ON(!new_buffer->free);
    
    	new_buffer_size = binder_buffer_size(proc, new_buffer);
    
    	binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    		     "%d: add free buffer, size %zd, at %p\n",
    		      proc->pid, new_buffer_size, new_buffer);
    
    	while (*p) {
    		parent = *p;
    		buffer = rb_entry(parent, struct binder_buffer, rb_node);
    		BUG_ON(!buffer->free);
    
    		buffer_size = binder_buffer_size(proc, buffer);
    
    		if (new_buffer_size < buffer_size)
    			p = &parent->rb_left;
    		else
    			p = &parent->rb_right;
    	}
    	rb_link_node(&new_buffer->rb_node, parent, p);
    	rb_insert_color(&new_buffer->rb_node, &proc->free_buffers);
    }
    
    static void binder_insert_allocated_buffer(struct binder_proc *proc,
    					   struct binder_buffer *new_buffer)
    {
    	struct rb_node **p = &proc->allocated_buffers.rb_node;
    	struct rb_node *parent = NULL;
    	struct binder_buffer *buffer;
    
    	BUG_ON(new_buffer->free);
    
    	while (*p) {
    		parent = *p;
    		buffer = rb_entry(parent, struct binder_buffer, rb_node);
    		BUG_ON(buffer->free);
    
    		if (new_buffer < buffer)
    			p = &parent->rb_left;
    		else if (new_buffer > buffer)
    			p = &parent->rb_right;
    		else
    			BUG();
    	}
    	rb_link_node(&new_buffer->rb_node, parent, p);
    	rb_insert_color(&new_buffer->rb_node, &proc->allocated_buffers);
    }
    
    static struct binder_buffer *binder_buffer_lookup(struct binder_proc *proc,
    						  uintptr_t user_ptr)
    {
    	struct rb_node *n = proc->allocated_buffers.rb_node;
    	struct binder_buffer *buffer;
    	struct binder_buffer *kern_ptr;
    
    	kern_ptr = (struct binder_buffer *)(user_ptr - proc->user_buffer_offset
    		- offsetof(struct binder_buffer, data));
    
    	while (n) {
    		buffer = rb_entry(n, struct binder_buffer, rb_node);
    		BUG_ON(buffer->free);
    
    		if (kern_ptr < buffer)
    			n = n->rb_left;
    		else if (kern_ptr > buffer)
    			n = n->rb_right;
    		else
    			return buffer;
    	}
    	return NULL;
    }
    
    static int binder_update_page_range(struct binder_proc *proc, int allocate,
    				    void *start, void *end,
    				    struct vm_area_struct *vma)
    {
    	void *page_addr;
    	unsigned long user_page_addr;
    	struct page **page;
    	struct mm_struct *mm;
    
    	binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    		     "%d: %s pages %p-%p\n", proc->pid,
    		     allocate ? "allocate" : "free", start, end);
    
    	if (end <= start)
    		return 0;
    
    	trace_binder_update_page_range(proc, allocate, start, end);
    
    	if (vma)
    		mm = NULL;
    	else
    		mm = get_task_mm(proc->tsk);
    
    	if (mm) {
    		down_write(&mm->mmap_sem);
    		vma = proc->vma;
    		if (vma && mm != proc->vma_vm_mm) {
    			pr_err("%d: vma mm and task mm mismatch\n",
    				proc->pid);
    			vma = NULL;
    		}
    	}
    
    	if (allocate == 0)
    		goto free_range;
    
    	if (vma == NULL) {
    		pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
    			proc->pid);
    		goto err_no_vma;
    	}
    
    	for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
    		int ret;
    
    		page = &proc->pages[(page_addr - proc->buffer) / PAGE_SIZE];
    
    		BUG_ON(*page);
    		*page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
    		if (*page == NULL) {
    			pr_err("%d: binder_alloc_buf failed for page at %p\n",
    				proc->pid, page_addr);
    			goto err_alloc_page_failed;
    		}
    		ret = map_kernel_range_noflush((unsigned long)page_addr,
    					PAGE_SIZE, PAGE_KERNEL, page);
    		flush_cache_vmap((unsigned long)page_addr,
    				(unsigned long)page_addr + PAGE_SIZE);
    		if (ret != 1) {
    			pr_err("%d: binder_alloc_buf failed to map page at %p in kernel\n",
    			       proc->pid, page_addr);
    			goto err_map_kernel_failed;
    		}
    		user_page_addr =
    			(uintptr_t)page_addr + proc->user_buffer_offset;
    		ret = vm_insert_page(vma, user_page_addr, page[0]);
    		if (ret) {
    			pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
    			       proc->pid, user_page_addr);
    			goto err_vm_insert_page_failed;
    		}
    		/* vm_insert_page does not seem to increment the refcount */
    	}
    	if (mm) {
    		up_write(&mm->mmap_sem);
    		mmput(mm);
    	}
    	return 0;
    
    free_range:
    	for (page_addr = end - PAGE_SIZE; page_addr >= start;
    	     page_addr -= PAGE_SIZE) {
    		page = &proc->pages[(page_addr - proc->buffer) / PAGE_SIZE];
    		if (vma)
    			zap_page_range(vma, (uintptr_t)page_addr +
    				proc->user_buffer_offset, PAGE_SIZE, NULL);
    err_vm_insert_page_failed:
    		unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
    err_map_kernel_failed:
    		__free_page(*page);
    		*page = NULL;
    err_alloc_page_failed:
    		;
    	}
    err_no_vma:
    	if (mm) {
    		up_write(&mm->mmap_sem);
    		mmput(mm);
    	}
    	return -ENOMEM;
    }
    
    static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc,
    					      size_t data_size,
    					      size_t offsets_size, int is_async)
    {
    	struct rb_node *n = proc->free_buffers.rb_node;
    	struct binder_buffer *buffer;
    	size_t buffer_size;
    	struct rb_node *best_fit = NULL;
    	void *has_page_addr;
    	void *end_page_addr;
    	size_t size;
    
    	if (proc->vma == NULL) {
    		pr_err("%d: binder_alloc_buf, no vma\n",
    		       proc->pid);
    		return NULL;
    	}
    
    	size = ALIGN(data_size, sizeof(void *)) +
    		ALIGN(offsets_size, sizeof(void *));
    
    	if (size < data_size || size < offsets_size) {
    		binder_user_error("%d: got transaction with invalid size %zd-%zd\n",
    				proc->pid, data_size, offsets_size);
    		return NULL;
    	}
    
    	if (is_async &&
    	    proc->free_async_space < size + sizeof(struct binder_buffer)) {
    		binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    			     "%d: binder_alloc_buf size %zd failed, no async space left\n",
    			      proc->pid, size);
    		return NULL;
    	}
    
    	while (n) {
    		buffer = rb_entry(n, struct binder_buffer, rb_node);
    		BUG_ON(!buffer->free);
    		buffer_size = binder_buffer_size(proc, buffer);
    
    		if (size < buffer_size) {
    			best_fit = n;
    			n = n->rb_left;
    		} else if (size > buffer_size)
    			n = n->rb_right;
    		else {
    			best_fit = n;
    			break;
    		}
    	}
    	if (best_fit == NULL) {
    		pr_err("%d: binder_alloc_buf size %zd failed, no address space\n",
    			proc->pid, size);
    		return NULL;
    	}
    	if (n == NULL) {
    		buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
    		buffer_size = binder_buffer_size(proc, buffer);
    	}
    
    	binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    		     "%d: binder_alloc_buf size %zd got buffer %p size %zd\n",
    		      proc->pid, size, buffer, buffer_size);
    
    	has_page_addr =
    		(void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK);
    	if (n == NULL) {
    		if (size + sizeof(struct binder_buffer) + 4 >= buffer_size)
    			buffer_size = size; /* no room for other buffers */
    		else
    			buffer_size = size + sizeof(struct binder_buffer);
    	}
    	end_page_addr =
    		(void *)PAGE_ALIGN((uintptr_t)buffer->data + buffer_size);
    	if (end_page_addr > has_page_addr)
    		end_page_addr = has_page_addr;
    	if (binder_update_page_range(proc, 1,
    	    (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr, NULL))
    		return NULL;
    
    	rb_erase(best_fit, &proc->free_buffers);
    	buffer->free = 0;
    	binder_insert_allocated_buffer(proc, buffer);
    	if (buffer_size != size) {
    		struct binder_buffer *new_buffer = (void *)buffer->data + size;
    
    		list_add(&new_buffer->entry, &buffer->entry);
    		new_buffer->free = 1;
    		binder_insert_free_buffer(proc, new_buffer);
    	}
    	binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    		     "%d: binder_alloc_buf size %zd got %p\n",
    		      proc->pid, size, buffer);
    	buffer->data_size = data_size;
    	buffer->offsets_size = offsets_size;
    	buffer->async_transaction = is_async;
    	if (is_async) {
    		proc->free_async_space -= size + sizeof(struct binder_buffer);
    		binder_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
    			     "%d: binder_alloc_buf size %zd async free %zd\n",
    			      proc->pid, size, proc->free_async_space);
    	}
    
    	return buffer;
    }
    
    static void *buffer_start_page(struct binder_buffer *buffer)
    {
    	return (void *)((uintptr_t)buffer & PAGE_MASK);
    }
    
    static void *buffer_end_page(struct binder_buffer *buffer)
    {
    	return (void *)(((uintptr_t)(buffer + 1) - 1) & PAGE_MASK);
    }
    
    static void binder_delete_free_buffer(struct binder_proc *proc,
    				      struct binder_buffer *buffer)
    {
    	struct binder_buffer *prev, *next = NULL;
    	int free_page_end = 1;
    	int free_page_start = 1;
    
    	BUG_ON(proc->buffers.next == &buffer->entry);
    	prev = list_entry(buffer->entry.prev, struct binder_buffer, entry);
    	BUG_ON(!prev->free);
    	if (buffer_end_page(prev) == buffer_start_page(buffer)) {
    		free_page_start = 0;
    		if (buffer_end_page(prev) == buffer_end_page(buffer))
    			free_page_end = 0;
    		binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    			     "%d: merge free, buffer %p share page with %p\n",
    			      proc->pid, buffer, prev);
    	}
    
    	if (!list_is_last(&buffer->entry, &proc->buffers)) {
    		next = list_entry(buffer->entry.next,
    				  struct binder_buffer, entry);
    		if (buffer_start_page(next) == buffer_end_page(buffer)) {
    			free_page_end = 0;
    			if (buffer_start_page(next) ==
    			    buffer_start_page(buffer))
    				free_page_start = 0;
    			binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    				     "%d: merge free, buffer %p share page with %p\n",
    				      proc->pid, buffer, prev);
    		}
    	}
    	list_del(&buffer->entry);
    	if (free_page_start || free_page_end) {
    		binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    			     "%d: merge free, buffer %p do not share page%s%s with %p or %p\n",
    			     proc->pid, buffer, free_page_start ? "" : " end",
    			     free_page_end ? "" : " start", prev, next);
    		binder_update_page_range(proc, 0, free_page_start ?
    			buffer_start_page(buffer) : buffer_end_page(buffer),
    			(free_page_end ? buffer_end_page(buffer) :
    			buffer_start_page(buffer)) + PAGE_SIZE, NULL);
    	}
    }
    
    static void binder_free_buf(struct binder_proc *proc,
    			    struct binder_buffer *buffer)
    {
    	size_t size, buffer_size;
    
    	buffer_size = binder_buffer_size(proc, buffer);
    
    	size = ALIGN(buffer->data_size, sizeof(void *)) +
    		ALIGN(buffer->offsets_size, sizeof(void *));
    
    	binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    		     "%d: binder_free_buf %p size %zd buffer_size %zd\n",
    		      proc->pid, buffer, size, buffer_size);
    
    	BUG_ON(buffer->free);
    	BUG_ON(size > buffer_size);
    	BUG_ON(buffer->transaction != NULL);
    	BUG_ON((void *)buffer < proc->buffer);
    	BUG_ON((void *)buffer > proc->buffer + proc->buffer_size);
    
    	if (buffer->async_transaction) {
    		proc->free_async_space += size + sizeof(struct binder_buffer);
    
    		binder_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
    			     "%d: binder_free_buf size %zd async free %zd\n",
    			      proc->pid, size, proc->free_async_space);
    	}
    
    	binder_update_page_range(proc, 0,
    		(void *)PAGE_ALIGN((uintptr_t)buffer->data),
    		(void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK),
    		NULL);
    	rb_erase(&buffer->rb_node, &proc->allocated_buffers);
    	buffer->free = 1;
    	if (!list_is_last(&buffer->entry, &proc->buffers)) {
    		struct binder_buffer *next = list_entry(buffer->entry.next,
    						struct binder_buffer, entry);
    
    		if (next->free) {
    			rb_erase(&next->rb_node, &proc->free_buffers);
    			binder_delete_free_buffer(proc, next);
    		}
    	}
    	if (proc->buffers.next != &buffer->entry) {
    		struct binder_buffer *prev = list_entry(buffer->entry.prev,
    						struct binder_buffer, entry);
    
    		if (prev->free) {
    			binder_delete_free_buffer(proc, buffer);
    			rb_erase(&prev->rb_node, &proc->free_buffers);
    			buffer = prev;
    		}
    	}
    	binder_insert_free_buffer(proc, buffer);
    }
    
    static struct binder_node *binder_get_node(struct binder_proc *proc,
    					   binder_uintptr_t ptr)
    {
    	struct rb_node *n = proc->nodes.rb_node;
    	struct binder_node *node;
    
    	while (n) {
    		node = rb_entry(n, struct binder_node, rb_node);
    
    		if (ptr < node->ptr)
    			n = n->rb_left;
    		else if (ptr > node->ptr)
    			n = n->rb_right;
    		else
    			return node;
    	}
    	return NULL;
    }
    
    static struct binder_node *binder_new_node(struct binder_proc *proc,
    					   binder_uintptr_t ptr,
    					   binder_uintptr_t cookie)
    {
    	struct rb_node **p = &proc->nodes.rb_node;
    	struct rb_node *parent = NULL;
    	struct binder_node *node;
    
    	while (*p) {
    		parent = *p;
    		node = rb_entry(parent, struct binder_node, rb_node);
    
    		if (ptr < node->ptr)
    			p = &(*p)->rb_left;
    		else if (ptr > node->ptr)
    			p = &(*p)->rb_right;
    		else
    			return NULL;
    	}
    
    	node = kzalloc(sizeof(*node), GFP_KERNEL);
    	if (node == NULL)
    		return NULL;
    	binder_stats_created(BINDER_STAT_NODE);
    	rb_link_node(&node->rb_node, parent, p);
    	rb_insert_color(&node->rb_node, &proc->nodes);
    	node->debug_id = ++binder_last_id;
    	node->proc = proc;
    	node->ptr = ptr;
    	node->cookie = cookie;
    	node->work.type = BINDER_WORK_NODE;
    	INIT_LIST_HEAD(&node->work.entry);
    	INIT_LIST_HEAD(&node->async_todo);
    	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    		     "%d:%d node %d u%016llx c%016llx created\n",
    		     proc->pid, current->pid, node->debug_id,
    		     (u64)node->ptr, (u64)node->cookie);
    	return node;
    }
    
    static int binder_inc_node(struct binder_node *node, int strong, int internal,
    			   struct list_head *target_list)
    {
    	if (strong) {
    		if (internal) {
    			if (target_list == NULL &&
    			    node->internal_strong_refs == 0 &&
    			    !(node->proc &&
    			      node == node->proc->context->binder_context_mgr_node &&
    			      node->has_strong_ref)) {
    				pr_err("invalid inc strong node for %d\n",
    					node->debug_id);
    				return -EINVAL;
    			}
    			node->internal_strong_refs++;
    		} else
    			node->local_strong_refs++;
    		if (!node->has_strong_ref && target_list) {
    			list_del_init(&node->work.entry);
    			list_add_tail(&node->work.entry, target_list);
    		}
    	} else {
    		if (!internal)
    			node->local_weak_refs++;
    		if (!node->has_weak_ref && list_empty(&node->work.entry)) {
    			if (target_list == NULL) {
    				pr_err("invalid inc weak node for %d\n",
    					node->debug_id);
    				return -EINVAL;
    			}
    			list_add_tail(&node->work.entry, target_list);
    		}
    	}
    	return 0;
    }
    
    static int binder_dec_node(struct binder_node *node, int strong, int internal)
    {
    	if (strong) {
    		if (internal)
    			node->internal_strong_refs--;
    		else
    			node->local_strong_refs--;
    		if (node->local_strong_refs || node->internal_strong_refs)
    			return 0;
    	} else {
    		if (!internal)
    			node->local_weak_refs--;
    		if (node->local_weak_refs || !hlist_empty(&node->refs))
    			return 0;
    	}
    	if (node->proc && (node->has_strong_ref || node->has_weak_ref)) {
    		if (list_empty(&node->work.entry)) {
    			list_add_tail(&node->work.entry, &node->proc->todo);
    			wake_up_interruptible(&node->proc->wait);
    		}
    	} else {
    		if (hlist_empty(&node->refs) && !node->local_strong_refs &&
    		    !node->local_weak_refs) {
    			list_del_init(&node->work.entry);
    			if (node->proc) {
    				rb_erase(&node->rb_node, &node->proc->nodes);
    				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    					     "refless node %d deleted\n",
    					     node->debug_id);
    			} else {
    				hlist_del(&node->dead_node);
    				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    					     "dead node %d deleted\n",
    					     node->debug_id);
    			}
    			kfree(node);
    			binder_stats_deleted(BINDER_STAT_NODE);
    		}
    	}
    
    	return 0;
    }
    
    
    static struct binder_ref *binder_get_ref(struct binder_proc *proc,
    					 u32 desc, bool need_strong_ref)
    {
    	struct rb_node *n = proc->refs_by_desc.rb_node;
    	struct binder_ref *ref;
    
    	while (n) {
    		ref = rb_entry(n, struct binder_ref, rb_node_desc);
    
    		if (desc < ref->desc) {
    			n = n->rb_left;
    		} else if (desc > ref->desc) {
    			n = n->rb_right;
    		} else if (need_strong_ref && !ref->strong) {
    			binder_user_error("tried to use weak ref as strong ref\n");
    			return NULL;
    		} else {
    			return ref;
    		}
    	}
    	return NULL;
    }
    
    static struct binder_ref *binder_get_ref_for_node(struct binder_proc *proc,
    						  struct binder_node *node)
    {
    	struct rb_node *n;
    	struct rb_node **p = &proc->refs_by_node.rb_node;
    	struct rb_node *parent = NULL;
    	struct binder_ref *ref, *new_ref;
    	struct binder_context *context = proc->context;
    
    	while (*p) {
    		parent = *p;
    		ref = rb_entry(parent, struct binder_ref, rb_node_node);
    
    		if (node < ref->node)
    			p = &(*p)->rb_left;
    		else if (node > ref->node)
    			p = &(*p)->rb_right;
    		else
    			return ref;
    	}
    	new_ref = kzalloc(sizeof(*ref), GFP_KERNEL);
    	if (new_ref == NULL)
    		return NULL;
    	binder_stats_created(BINDER_STAT_REF);
    	new_ref->debug_id = ++binder_last_id;
    	new_ref->proc = proc;
    	new_ref->node = node;
    	rb_link_node(&new_ref->rb_node_node, parent, p);
    	rb_insert_color(&new_ref->rb_node_node, &proc->refs_by_node);
    
    	new_ref->desc = (node == context->binder_context_mgr_node) ? 0 : 1;
    	for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) {
    		ref = rb_entry(n, struct binder_ref, rb_node_desc);
    		if (ref->desc > new_ref->desc)
    			break;
    		new_ref->desc = ref->desc + 1;
    	}
    
    	p = &proc->refs_by_desc.rb_node;
    	while (*p) {
    		parent = *p;
    		ref = rb_entry(parent, struct binder_ref, rb_node_desc);
    
    		if (new_ref->desc < ref->desc)
    			p = &(*p)->rb_left;
    		else if (new_ref->desc > ref->desc)
    			p = &(*p)->rb_right;
    		else
    			BUG();
    	}
    	rb_link_node(&new_ref->rb_node_desc, parent, p);
    	rb_insert_color(&new_ref->rb_node_desc, &proc->refs_by_desc);
    	if (node) {
    		hlist_add_head(&new_ref->node_entry, &node->refs);
    
    		binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    			     "%d new ref %d desc %d for node %d\n",
    			      proc->pid, new_ref->debug_id, new_ref->desc,
    			      node->debug_id);
    	} else {
    		binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    			     "%d new ref %d desc %d for dead node\n",
    			      proc->pid, new_ref->debug_id, new_ref->desc);
    	}
    	return new_ref;
    }
    
    static void binder_delete_ref(struct binder_ref *ref)
    {
    	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    		     "%d delete ref %d desc %d for node %d\n",
    		      ref->proc->pid, ref->debug_id, ref->desc,
    		      ref->node->debug_id);
    
    	rb_erase(&ref->rb_node_desc, &ref->proc->refs_by_desc);
    	rb_erase(&ref->rb_node_node, &ref->proc->refs_by_node);
    	if (ref->strong)
    		binder_dec_node(ref->node, 1, 1);
    	hlist_del(&ref->node_entry);
    	binder_dec_node(ref->node, 0, 1);
    	if (ref->death) {
    		binder_debug(BINDER_DEBUG_DEAD_BINDER,
    			     "%d delete ref %d desc %d has death notification\n",
    			      ref->proc->pid, ref->debug_id, ref->desc);
    		list_del(&ref->death->work.entry);
    		kfree(ref->death);
    		binder_stats_deleted(BINDER_STAT_DEATH);
    	}
    	kfree(ref);
    	binder_stats_deleted(BINDER_STAT_REF);
    }
    
    static int binder_inc_ref(struct binder_ref *ref, int strong,
    			  struct list_head *target_list)
    {
    	int ret;
    
    	if (strong) {
    		if (ref->strong == 0) {
    			ret = binder_inc_node(ref->node, 1, 1, target_list);
    			if (ret)
    				return ret;
    		}
    		ref->strong++;
    	} else {
    		if (ref->weak == 0) {
    			ret = binder_inc_node(ref->node, 0, 1, target_list);
    			if (ret)
    				return ret;
    		}
    		ref->weak++;
    	}
    	return 0;
    }
    
    
    static int binder_dec_ref(struct binder_ref *ref, int strong)
    {
    	if (strong) {
    		if (ref->strong == 0) {
    			binder_user_error("%d invalid dec strong, ref %d desc %d s %d w %d\n",
    					  ref->proc->pid, ref->debug_id,
    					  ref->desc, ref->strong, ref->weak);
    			return -EINVAL;
    		}
    		ref->strong--;
    		if (ref->strong == 0) {
    			int ret;
    
    			ret = binder_dec_node(ref->node, strong, 1);
    			if (ret)
    				return ret;
    		}
    	} else {
    		if (ref->weak == 0) {
    			binder_user_error("%d invalid dec weak, ref %d desc %d s %d w %d\n",
    					  ref->proc->pid, ref->debug_id,
    					  ref->desc, ref->strong, ref->weak);
    			return -EINVAL;
    		}
    		ref->weak--;
    	}
    	if (ref->strong == 0 && ref->weak == 0)
    		binder_delete_ref(ref);
    	return 0;
    }
    
    static void binder_pop_transaction(struct binder_thread *target_thread,
    				   struct binder_transaction *t)
    {
    	if (target_thread) {
    		BUG_ON(target_thread->transaction_stack != t);
    		BUG_ON(target_thread->transaction_stack->from != target_thread);
    		target_thread->transaction_stack =
    			target_thread->transaction_stack->from_parent;
    		t->from = NULL;
    	}
    	t->need_reply = 0;
    	if (t->buffer)
    		t->buffer->transaction = NULL;
    	kfree(t);
    	binder_stats_deleted(BINDER_STAT_TRANSACTION);
    }
    
    static void binder_send_failed_reply(struct binder_transaction *t,
    				     uint32_t error_code)
    {
    	struct binder_thread *target_thread;
    	struct binder_transaction *next;
    
    	BUG_ON(t->flags & TF_ONE_WAY);
    	while (1) {
    		target_thread = t->from;
    		if (target_thread) {
    			if (target_thread->return_error != BR_OK &&
    			   target_thread->return_error2 == BR_OK) {
    				target_thread->return_error2 =
    					target_thread->return_error;
    				target_thread->return_error = BR_OK;
    			}
    			if (target_thread->return_error == BR_OK) {
    				binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
    					     "send failed reply for transaction %d to %d:%d\n",
    					      t->debug_id,
    					      target_thread->proc->pid,
    					      target_thread->pid);
    
    				binder_pop_transaction(target_thread, t);
    				target_thread->return_error = error_code;
    				wake_up_interruptible(&target_thread->wait);
    			} else {
    				pr_err("reply failed, target thread, %d:%d, has error code %d already\n",
    					target_thread->proc->pid,
    					target_thread->pid,
    					target_thread->return_error);
    			}
    			return;
    		}
    		next = t->from_parent;
    
    		binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
    			     "send failed reply for transaction %d, target dead\n",
    			     t->debug_id);
    
    		binder_pop_transaction(target_thread, t);
    		if (next == NULL) {
    			binder_debug(BINDER_DEBUG_DEAD_BINDER,
    				     "reply failed, no target thread at root\n");
    			return;
    		}
    		t = next;
    		binder_debug(BINDER_DEBUG_DEAD_BINDER,
    			     "reply failed, no target thread -- retry %d\n",
    			      t->debug_id);
    	}
    }
    
    /**
     * binder_validate_object() - checks for a valid metadata object in a buffer.
     * @buffer:	binder_buffer that we're parsing.
     * @offset:	offset in the buffer at which to validate an object.
     *
     * Return:	If there's a valid metadata object at @offset in @buffer, the
     *		size of that object. Otherwise, it returns zero.
     */
    static size_t binder_validate_object(struct binder_buffer *buffer, u64 offset)
    {
    	/* Check if we can read a header first */
    	struct binder_object_header *hdr;
    	size_t object_size = 0;
    
    	if (offset > buffer->data_size - sizeof(*hdr) ||
    	    buffer->data_size < sizeof(*hdr) ||
    	    !IS_ALIGNED(offset, sizeof(u32)))
    		return 0;
    
    	/* Ok, now see if we can read a complete object. */
    	hdr = (struct binder_object_header *)(buffer->data + offset);
    	switch (hdr->type) {
    	case BINDER_TYPE_BINDER:
    	case BINDER_TYPE_WEAK_BINDER:
    	case BINDER_TYPE_HANDLE:
    	case BINDER_TYPE_WEAK_HANDLE:
    		object_size = sizeof(struct flat_binder_object);
    		break;
    	case BINDER_TYPE_FD:
    		object_size = sizeof(struct binder_fd_object);
    		break;
    	default:
    		return 0;
    	}
    	if (offset <= buffer->data_size - object_size &&
    	    buffer->data_size >= object_size)
    		return object_size;
    	else
    		return 0;
    }
    
    static void binder_transaction_buffer_release(struct binder_proc *proc,
    					      struct binder_buffer *buffer,
    					      binder_size_t *failed_at)
    {
    	binder_size_t *offp, *off_end;
    	int debug_id = buffer->debug_id;
    
    	binder_debug(BINDER_DEBUG_TRANSACTION,
    		     "%d buffer release %d, size %zd-%zd, failed at %p\n",
    		     proc->pid, buffer->debug_id,
    		     buffer->data_size, buffer->offsets_size, failed_at);
    
    	if (buffer->target_node)
    		binder_dec_node(buffer->target_node, 1, 0);
    
    	offp = (binder_size_t *)(buffer->data +
    				 ALIGN(buffer->data_size, sizeof(void *)));
    	if (failed_at)
    		off_end = failed_at;
    	else
    		off_end = (void *)offp + buffer->offsets_size;
    	for (; offp < off_end; offp++) {
    		struct binder_object_header *hdr;
    		size_t object_size = binder_validate_object(buffer, *offp);
    
    		if (object_size == 0) {
    			pr_err("transaction release %d bad object at offset %lld, size %zd\n",
    			       debug_id, (u64)*offp, buffer->data_size);
    			continue;
    		}
    		hdr = (struct binder_object_header *)(buffer->data + *offp);
    		switch (hdr->type) {
    		case BINDER_TYPE_BINDER:
    		case BINDER_TYPE_WEAK_BINDER: {
    			struct flat_binder_object *fp;
    			struct binder_node *node;
    
    			fp = to_flat_binder_object(hdr);
    			node = binder_get_node(proc, fp->binder);
    			if (node == NULL) {
    				pr_err("transaction release %d bad node %016llx\n",
    				       debug_id, (u64)fp->binder);
    				break;
    			}
    			binder_debug(BINDER_DEBUG_TRANSACTION,
    				     "        node %d u%016llx\n",
    				     node->debug_id, (u64)node->ptr);
    			binder_dec_node(node, hdr->type == BINDER_TYPE_BINDER,
    					0);
    		} break;
    		case BINDER_TYPE_HANDLE:
    		case BINDER_TYPE_WEAK_HANDLE: {
    			struct flat_binder_object *fp;
    			struct binder_ref *ref;
    
    			fp = to_flat_binder_object(hdr);
    			ref = binder_get_ref(proc, fp->handle,
    					     hdr->type == BINDER_TYPE_HANDLE);
    			if (ref == NULL) {
    				pr_err("transaction release %d bad handle %d\n",
    				 debug_id, fp->handle);
    				break;
    			}
    			binder_debug(BINDER_DEBUG_TRANSACTION,
    				     "        ref %d desc %d (node %d)\n",
    				     ref->debug_id, ref->desc, ref->node->debug_id);
    			binder_dec_ref(ref, hdr->type == BINDER_TYPE_HANDLE);
    		} break;
    
    		case BINDER_TYPE_FD: {
    			struct binder_fd_object *fp = to_binder_fd_object(hdr);
    
    			binder_debug(BINDER_DEBUG_TRANSACTION,
    				     "        fd %d\n", fp->fd);
    			if (failed_at)
    				task_close_fd(proc, fp->fd);
    		} break;
    
    		default:
    			pr_err("transaction release %d bad object type %x\n",
    				debug_id, hdr->type);
    			break;
    		}
    	}
    }
    
    static void binder_transaction(struct binder_proc *proc,
    			       struct binder_thread *thread,
    			       struct binder_transaction_data *tr, int reply)
    {
    	struct binder_transaction *t;
    	struct binder_work *tcomplete;
    	binder_size_t *offp, *off_end;
    	binder_size_t off_min;
    	struct binder_proc *target_proc;
    	struct binder_thread *target_thread = NULL;
    	struct binder_node *target_node = NULL;
    	struct list_head *target_list;
    	wait_queue_head_t *target_wait;
    	struct binder_transaction *in_reply_to = NULL;
    	struct binder_transaction_log_entry *e;
    	uint32_t return_error;
    	struct binder_context *context = proc->context;
    
    	e = binder_transaction_log_add(&binder_transaction_log);
    	e->call_type = reply ? 2 : !!(tr->flags & TF_ONE_WAY);
    	e->from_proc = proc->pid;
    	e->from_thread = thread->pid;
    	e->target_handle = tr->target.handle;
    	e->data_size = tr->data_size;
    	e->offsets_size = tr->offsets_size;
    	e->context_name = proc->context->name;
    
    	if (reply) {
    		in_reply_to = thread->transaction_stack;
    		if (in_reply_to == NULL) {
    			binder_user_error("%d:%d got reply transaction with no transaction stack\n",
    					  proc->pid, thread->pid);
    			return_error = BR_FAILED_REPLY;
    			goto err_empty_call_stack;
    		}
    		binder_set_nice(in_reply_to->saved_priority);
    		if (in_reply_to->to_thread != thread) {
    			binder_user_error("%d:%d got reply transaction with bad transaction stack, transaction %d has target %d:%d\n",
    				proc->pid, thread->pid, in_reply_to->debug_id,
    				in_reply_to->to_proc ?
    				in_reply_to->to_proc->pid : 0,
    				in_reply_to->to_thread ?
    				in_reply_to->to_thread->pid : 0);
    			return_error = BR_FAILED_REPLY;
    			in_reply_to = NULL;
    			goto err_bad_call_stack;
    		}
    		thread->transaction_stack = in_reply_to->to_parent;
    		target_thread = in_reply_to->from;
    		if (target_thread == NULL) {
    			return_error = BR_DEAD_REPLY;
    			goto err_dead_binder;
    		}
    		if (target_thread->transaction_stack != in_reply_to) {
    			binder_user_error("%d:%d got reply transaction with bad target transaction stack %d, expected %d\n",
    				proc->pid, thread->pid,
    				target_thread->transaction_stack ?
    				target_thread->transaction_stack->debug_id : 0,
    				in_reply_to->debug_id);
    			return_error = BR_FAILED_REPLY;
    			in_reply_to = NULL;
    			target_thread = NULL;
    			goto err_dead_binder;
    		}
    		target_proc = target_thread->proc;
    	} else {
    		if (tr->target.handle) {
    			struct binder_ref *ref;
    
    			ref = binder_get_ref(proc, tr->target.handle, true);
    			if (ref == NULL) {
    				binder_user_error("%d:%d got transaction to invalid handle\n",
    					proc->pid, thread->pid);
    				return_error = BR_FAILED_REPLY;
    				goto err_invalid_target_handle;
    			}
    			target_node = ref->node;
    		} else {
    			target_node = context->binder_context_mgr_node;
    			if (target_node == NULL) {
    				return_error = BR_DEAD_REPLY;
    				goto err_no_context_mgr_node;
    			}
    		}
    		e->to_node = target_node->debug_id;
    		target_proc = target_node->proc;
    		if (target_proc == NULL) {
    			return_error = BR_DEAD_REPLY;
    			goto err_dead_binder;
    		}
    		if (security_binder_transaction(proc->tsk,
    						target_proc->tsk) < 0) {
    			return_error = BR_FAILED_REPLY;
    			goto err_invalid_target_handle;
    		}
    		if (!(tr->flags & TF_ONE_WAY) && thread->transaction_stack) {
    			struct binder_transaction *tmp;
    
    			tmp = thread->transaction_stack;
    			if (tmp->to_thread != thread) {
    				binder_user_error("%d:%d got new transaction with bad transaction stack, transaction %d has target %d:%d\n",
    					proc->pid, thread->pid, tmp->debug_id,
    					tmp->to_proc ? tmp->to_proc->pid : 0,
    					tmp->to_thread ?
    					tmp->to_thread->pid : 0);
    				return_error = BR_FAILED_REPLY;
    				goto err_bad_call_stack;
    			}
    			while (tmp) {
    				if (tmp->from && tmp->from->proc == target_proc)
    					target_thread = tmp->from;
    				tmp = tmp->from_parent;
    			}
    		}
    	}
    	if (target_thread) {
    		e->to_thread = target_thread->pid;
    		target_list = &target_thread->todo;
    		target_wait = &target_thread->wait;
    	} else {
    		target_list = &target_proc->todo;
    		target_wait = &target_proc->wait;
    	}
    	e->to_proc = target_proc->pid;
    
    	/* TODO: reuse incoming transaction for reply */
    	t = kzalloc(sizeof(*t), GFP_KERNEL);
    	if (t == NULL) {
    		return_error = BR_FAILED_REPLY;
    		goto err_alloc_t_failed;
    	}
    	binder_stats_created(BINDER_STAT_TRANSACTION);
    
    	tcomplete = kzalloc(sizeof(*tcomplete), GFP_KERNEL);
    	if (tcomplete == NULL) {
    		return_error = BR_FAILED_REPLY;
    		goto err_alloc_tcomplete_failed;
    	}
    	binder_stats_created(BINDER_STAT_TRANSACTION_COMPLETE);
    
    	t->debug_id = ++binder_last_id;
    	e->debug_id = t->debug_id;
    
    	if (reply)
    		binder_debug(BINDER_DEBUG_TRANSACTION,
    			     "%d:%d BC_REPLY %d -> %d:%d, data %016llx-%016llx size %lld-%lld\n",
    			     proc->pid, thread->pid, t->debug_id,
    			     target_proc->pid, target_thread->pid,
    			     (u64)tr->data.ptr.buffer,
    			     (u64)tr->data.ptr.offsets,
    			     (u64)tr->data_size, (u64)tr->offsets_size);
    	else
    		binder_debug(BINDER_DEBUG_TRANSACTION,
    			     "%d:%d BC_TRANSACTION %d -> %d - node %d, data %016llx-%016llx size %lld-%lld\n",
    			     proc->pid, thread->pid, t->debug_id,
    			     target_proc->pid, target_node->debug_id,
    			     (u64)tr->data.ptr.buffer,
    			     (u64)tr->data.ptr.offsets,
    			     (u64)tr->data_size, (u64)tr->offsets_size);
    
    	if (!reply && !(tr->flags & TF_ONE_WAY))
    		t->from = thread;
    	else
    		t->from = NULL;
    	t->sender_euid = task_euid(proc->tsk);
    	t->to_proc = target_proc;
    	t->to_thread = target_thread;
    	t->code = tr->code;
    	t->flags = tr->flags;
    	t->priority = task_nice(current);
    
    	trace_binder_transaction(reply, t, target_node);
    
    	t->buffer = binder_alloc_buf(target_proc, tr->data_size,
    		tr->offsets_size, !reply && (t->flags & TF_ONE_WAY));
    	if (t->buffer == NULL) {
    		return_error = BR_FAILED_REPLY;
    		goto err_binder_alloc_buf_failed;
    	}
    	t->buffer->allow_user_free = 0;
    	t->buffer->debug_id = t->debug_id;
    	t->buffer->transaction = t;
    	t->buffer->target_node = target_node;
    	trace_binder_transaction_alloc_buf(t->buffer);
    	if (target_node)
    		binder_inc_node(target_node, 1, 0, NULL);
    
    	offp = (binder_size_t *)(t->buffer->data +
    				 ALIGN(tr->data_size, sizeof(void *)));
    
    	if (copy_from_user(t->buffer->data, (const void __user *)(uintptr_t)
    			   tr->data.ptr.buffer, tr->data_size)) {
    		binder_user_error("%d:%d got transaction with invalid data ptr\n",
    				proc->pid, thread->pid);
    		return_error = BR_FAILED_REPLY;
    		goto err_copy_data_failed;
    	}
    	if (copy_from_user(offp, (const void __user *)(uintptr_t)
    			   tr->data.ptr.offsets, tr->offsets_size)) {
    		binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
    				proc->pid, thread->pid);
    		return_error = BR_FAILED_REPLY;
    		goto err_copy_data_failed;
    	}
    	if (!IS_ALIGNED(tr->offsets_size, sizeof(binder_size_t))) {
    		binder_user_error("%d:%d got transaction with invalid offsets size, %lld\n",
    				proc->pid, thread->pid, (u64)tr->offsets_size);
    		return_error = BR_FAILED_REPLY;
    		goto err_bad_offset;
    	}
    	off_end = (void *)offp + tr->offsets_size;
    	off_min = 0;
    	for (; offp < off_end; offp++) {
    		struct binder_object_header *hdr;
    		size_t object_size = binder_validate_object(t->buffer, *offp);
    
    		if (object_size == 0 || *offp < off_min) {
    			binder_user_error("%d:%d got transaction with invalid offset (%lld, min %lld max %lld) or object.\n",
    					  proc->pid, thread->pid, (u64)*offp,
    					  (u64)off_min,
    					  (u64)t->buffer->data_size);
    			return_error = BR_FAILED_REPLY;
    			goto err_bad_offset;
    		}
    
    		hdr = (struct binder_object_header *)(t->buffer->data + *offp);
    		off_min = *offp + object_size;
    		switch (hdr->type) {
    		case BINDER_TYPE_BINDER:
    		case BINDER_TYPE_WEAK_BINDER: {
    			struct flat_binder_object *fp;
    			struct binder_node *node;
    			struct binder_ref *ref;
    
    			fp = to_flat_binder_object(hdr);
    			node = binder_get_node(proc, fp->binder);
    			if (node == NULL) {
    				node = binder_new_node(proc, fp->binder, fp->cookie);
    				if (node == NULL) {
    					return_error = BR_FAILED_REPLY;
    					goto err_binder_new_node_failed;
    				}
    				node->min_priority = fp->flags & FLAT_BINDER_FLAG_PRIORITY_MASK;
    				node->accept_fds = !!(fp->flags & FLAT_BINDER_FLAG_ACCEPTS_FDS);
    			}
    			if (fp->cookie != node->cookie) {
    				binder_user_error("%d:%d sending u%016llx node %d, cookie mismatch %016llx != %016llx\n",
    					proc->pid, thread->pid,
    					(u64)fp->binder, node->debug_id,
    					(u64)fp->cookie, (u64)node->cookie);
    				return_error = BR_FAILED_REPLY;
    				goto err_binder_get_ref_for_node_failed;
    			}
    			if (security_binder_transfer_binder(proc->tsk,
    							    target_proc->tsk)) {
    				return_error = BR_FAILED_REPLY;
    				goto err_binder_get_ref_for_node_failed;
    			}
    			ref = binder_get_ref_for_node(target_proc, node);
    			if (ref == NULL) {
    				return_error = BR_FAILED_REPLY;
    				goto err_binder_get_ref_for_node_failed;
    			}
    			if (hdr->type == BINDER_TYPE_BINDER)
    				hdr->type = BINDER_TYPE_HANDLE;
    			else
    				hdr->type = BINDER_TYPE_WEAK_HANDLE;
    			fp->binder = 0;
    			fp->handle = ref->desc;
    			fp->cookie = 0;
    			binder_inc_ref(ref, hdr->type == BINDER_TYPE_HANDLE,
    				       &thread->todo);
    
    			trace_binder_transaction_node_to_ref(t, node, ref);
    			binder_debug(BINDER_DEBUG_TRANSACTION,
    				     "        node %d u%016llx -> ref %d desc %d\n",
    				     node->debug_id, (u64)node->ptr,
    				     ref->debug_id, ref->desc);
    		} break;
    		case BINDER_TYPE_HANDLE:
    		case BINDER_TYPE_WEAK_HANDLE: {
    			struct flat_binder_object *fp;
    			struct binder_ref *ref;
    
    			fp = to_flat_binder_object(hdr);
    			ref = binder_get_ref(proc, fp->handle,
    					     hdr->type == BINDER_TYPE_HANDLE);
    			if (ref == NULL) {
    				binder_user_error("%d:%d got transaction with invalid handle, %d\n",
    						proc->pid,
    						thread->pid, fp->handle);
    				return_error = BR_FAILED_REPLY;
    				goto err_binder_get_ref_failed;
    			}
    			if (security_binder_transfer_binder(proc->tsk,
    							    target_proc->tsk)) {
    				return_error = BR_FAILED_REPLY;
    				goto err_binder_get_ref_failed;
    			}
    			if (ref->node->proc == target_proc) {
    				if (hdr->type == BINDER_TYPE_HANDLE)
    					hdr->type = BINDER_TYPE_BINDER;
    				else
    					hdr->type = BINDER_TYPE_WEAK_BINDER;
    				fp->binder = ref->node->ptr;
    				fp->cookie = ref->node->cookie;
    				binder_inc_node(ref->node,
    						hdr->type == BINDER_TYPE_BINDER,
    						0, NULL);
    				trace_binder_transaction_ref_to_node(t, ref);
    				binder_debug(BINDER_DEBUG_TRANSACTION,
    					     "        ref %d desc %d -> node %d u%016llx\n",
    					     ref->debug_id, ref->desc, ref->node->debug_id,
    					     (u64)ref->node->ptr);
    			} else {
    				struct binder_ref *new_ref;
    
    				new_ref = binder_get_ref_for_node(target_proc, ref->node);
    				if (new_ref == NULL) {
    					return_error = BR_FAILED_REPLY;
    					goto err_binder_get_ref_for_node_failed;
    				}
    				fp->binder = 0;
    				fp->handle = new_ref->desc;
    				fp->cookie = 0;
    				binder_inc_ref(new_ref,
    					       hdr->type == BINDER_TYPE_HANDLE,
    					       NULL);
    				trace_binder_transaction_ref_to_ref(t, ref,
    								    new_ref);
    				binder_debug(BINDER_DEBUG_TRANSACTION,
    					     "        ref %d desc %d -> ref %d desc %d (node %d)\n",
    					     ref->debug_id, ref->desc, new_ref->debug_id,
    					     new_ref->desc, ref->node->debug_id);
    			}
    		} break;
    
    		case BINDER_TYPE_FD: {
    			int target_fd;
    			struct file *file;
    			struct binder_fd_object *fp = to_binder_fd_object(hdr);
    
    			if (reply) {
    				if (!(in_reply_to->flags & TF_ACCEPT_FDS)) {
    					binder_user_error("%d:%d got reply with fd, %d, but target does not allow fds\n",
    						proc->pid, thread->pid, fp->fd);
    					return_error = BR_FAILED_REPLY;
    					goto err_fd_not_allowed;
    				}
    			} else if (!target_node->accept_fds) {
    				binder_user_error("%d:%d got transaction with fd, %d, but target does not allow fds\n",
    					proc->pid, thread->pid, fp->fd);
    				return_error = BR_FAILED_REPLY;
    				goto err_fd_not_allowed;
    			}
    
    			file = fget(fp->fd);
    			if (file == NULL) {
    				binder_user_error("%d:%d got transaction with invalid fd, %d\n",
    					proc->pid, thread->pid, fp->fd);
    				return_error = BR_FAILED_REPLY;
    				goto err_fget_failed;
    			}
    			if (security_binder_transfer_file(proc->tsk,
    							  target_proc->tsk,
    							  file) < 0) {
    				fput(file);
    				return_error = BR_FAILED_REPLY;
    				goto err_get_unused_fd_failed;
    			}
    			target_fd = task_get_unused_fd_flags(target_proc, O_CLOEXEC);
    			if (target_fd < 0) {
    				fput(file);
    				return_error = BR_FAILED_REPLY;
    				goto err_get_unused_fd_failed;
    			}
    			task_fd_install(target_proc, target_fd, file);
    			trace_binder_transaction_fd(t, fp->fd, target_fd);
    			binder_debug(BINDER_DEBUG_TRANSACTION,
    				     "        fd %d -> %d\n", fp->fd,
    				     target_fd);
    			/* TODO: fput? */
    			fp->pad_binder = 0;
    			fp->fd = target_fd;
    		} break;
    
    		default:
    			binder_user_error("%d:%d got transaction with invalid object type, %x\n",
    				proc->pid, thread->pid, hdr->type);
    			return_error = BR_FAILED_REPLY;
    			goto err_bad_object_type;
    		}
    	}
    	if (reply) {
    		BUG_ON(t->buffer->async_transaction != 0);
    		binder_pop_transaction(target_thread, in_reply_to);
    	} else if (!(t->flags & TF_ONE_WAY)) {
    		BUG_ON(t->buffer->async_transaction != 0);
    		t->need_reply = 1;
    		t->from_parent = thread->transaction_stack;
    		thread->transaction_stack = t;
    	} else {
    		BUG_ON(target_node == NULL);
    		BUG_ON(t->buffer->async_transaction != 1);
    		if (target_node->has_async_transaction) {
    			target_list = &target_node->async_todo;
    			target_wait = NULL;
    		} else
    			target_node->has_async_transaction = 1;
    	}
    	t->work.type = BINDER_WORK_TRANSACTION;
    	list_add_tail(&t->work.entry, target_list);
    	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
    	list_add_tail(&tcomplete->entry, &thread->todo);
    	if (target_wait)
    		wake_up_interruptible(target_wait);
    	return;
    
    err_get_unused_fd_failed:
    err_fget_failed:
    err_fd_not_allowed:
    err_binder_get_ref_for_node_failed:
    err_binder_get_ref_failed:
    err_binder_new_node_failed:
    err_bad_object_type:
    err_bad_offset:
    err_copy_data_failed:
    	trace_binder_transaction_failed_buffer_release(t->buffer);
    	binder_transaction_buffer_release(target_proc, t->buffer, offp);
    	t->buffer->transaction = NULL;
    	binder_free_buf(target_proc, t->buffer);
    err_binder_alloc_buf_failed:
    	kfree(tcomplete);
    	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
    err_alloc_tcomplete_failed:
    	kfree(t);
    	binder_stats_deleted(BINDER_STAT_TRANSACTION);
    err_alloc_t_failed:
    err_bad_call_stack:
    err_empty_call_stack:
    err_dead_binder:
    err_invalid_target_handle:
    err_no_context_mgr_node:
    	binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
    		     "%d:%d transaction failed %d, size %lld-%lld\n",
    		     proc->pid, thread->pid, return_error,
    		     (u64)tr->data_size, (u64)tr->offsets_size);
    
    	{
    		struct binder_transaction_log_entry *fe;
    
    		fe = binder_transaction_log_add(&binder_transaction_log_failed);
    		*fe = *e;
    	}
    
    	BUG_ON(thread->return_error != BR_OK);
    	if (in_reply_to) {
    		thread->return_error = BR_TRANSACTION_COMPLETE;
    		binder_send_failed_reply(in_reply_to, return_error);
    	} else
    		thread->return_error = return_error;
    }
    
    static int binder_thread_write(struct binder_proc *proc,
    			struct binder_thread *thread,
    			binder_uintptr_t binder_buffer, size_t size,
    			binder_size_t *consumed)
    {
    	uint32_t cmd;
    	struct binder_context *context = proc->context;
    	void __user *buffer = (void __user *)(uintptr_t)binder_buffer;
    	void __user *ptr = buffer + *consumed;
    	void __user *end = buffer + size;
    
    	while (ptr < end && thread->return_error == BR_OK) {
    		if (get_user(cmd, (uint32_t __user *)ptr))
    			return -EFAULT;
    		ptr += sizeof(uint32_t);
    		trace_binder_command(cmd);
    		if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.bc)) {
    			binder_stats.bc[_IOC_NR(cmd)]++;
    			proc->stats.bc[_IOC_NR(cmd)]++;
    			thread->stats.bc[_IOC_NR(cmd)]++;
    		}
    		switch (cmd) {
    		case BC_INCREFS:
    		case BC_ACQUIRE:
    		case BC_RELEASE:
    		case BC_DECREFS: {
    			uint32_t target;
    			struct binder_ref *ref;
    			const char *debug_string;
    
    			if (get_user(target, (uint32_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(uint32_t);
    			if (target == 0 && context->binder_context_mgr_node &&
    			    (cmd == BC_INCREFS || cmd == BC_ACQUIRE)) {
    				ref = binder_get_ref_for_node(proc,
    					context->binder_context_mgr_node);
    				if (ref->desc != target) {
    					binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
    						proc->pid, thread->pid,
    						ref->desc);
    				}
    			} else
    				ref = binder_get_ref(proc, target,
    						     cmd == BC_ACQUIRE ||
    						     cmd == BC_RELEASE);
    			if (ref == NULL) {
    				binder_user_error("%d:%d refcount change on invalid ref %d\n",
    					proc->pid, thread->pid, target);
    				break;
    			}
    			switch (cmd) {
    			case BC_INCREFS:
    				debug_string = "IncRefs";
    				binder_inc_ref(ref, 0, NULL);
    				break;
    			case BC_ACQUIRE:
    				debug_string = "Acquire";
    				binder_inc_ref(ref, 1, NULL);
    				break;
    			case BC_RELEASE:
    				debug_string = "Release";
    				binder_dec_ref(ref, 1);
    				break;
    			case BC_DECREFS:
    			default:
    				debug_string = "DecRefs";
    				binder_dec_ref(ref, 0);
    				break;
    			}
    			binder_debug(BINDER_DEBUG_USER_REFS,
    				     "%d:%d %s ref %d desc %d s %d w %d for node %d\n",
    				     proc->pid, thread->pid, debug_string, ref->debug_id,
    				     ref->desc, ref->strong, ref->weak, ref->node->debug_id);
    			break;
    		}
    		case BC_INCREFS_DONE:
    		case BC_ACQUIRE_DONE: {
    			binder_uintptr_t node_ptr;
    			binder_uintptr_t cookie;
    			struct binder_node *node;
    
    			if (get_user(node_ptr, (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(binder_uintptr_t);
    			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(binder_uintptr_t);
    			node = binder_get_node(proc, node_ptr);
    			if (node == NULL) {
    				binder_user_error("%d:%d %s u%016llx no match\n",
    					proc->pid, thread->pid,
    					cmd == BC_INCREFS_DONE ?
    					"BC_INCREFS_DONE" :
    					"BC_ACQUIRE_DONE",
    					(u64)node_ptr);
    				break;
    			}
    			if (cookie != node->cookie) {
    				binder_user_error("%d:%d %s u%016llx node %d cookie mismatch %016llx != %016llx\n",
    					proc->pid, thread->pid,
    					cmd == BC_INCREFS_DONE ?
    					"BC_INCREFS_DONE" : "BC_ACQUIRE_DONE",
    					(u64)node_ptr, node->debug_id,
    					(u64)cookie, (u64)node->cookie);
    				break;
    			}
    			if (cmd == BC_ACQUIRE_DONE) {
    				if (node->pending_strong_ref == 0) {
    					binder_user_error("%d:%d BC_ACQUIRE_DONE node %d has no pending acquire request\n",
    						proc->pid, thread->pid,
    						node->debug_id);
    					break;
    				}
    				node->pending_strong_ref = 0;
    			} else {
    				if (node->pending_weak_ref == 0) {
    					binder_user_error("%d:%d BC_INCREFS_DONE node %d has no pending increfs request\n",
    						proc->pid, thread->pid,
    						node->debug_id);
    					break;
    				}
    				node->pending_weak_ref = 0;
    			}
    			binder_dec_node(node, cmd == BC_ACQUIRE_DONE, 0);
    			binder_debug(BINDER_DEBUG_USER_REFS,
    				     "%d:%d %s node %d ls %d lw %d\n",
    				     proc->pid, thread->pid,
    				     cmd == BC_INCREFS_DONE ? "BC_INCREFS_DONE" : "BC_ACQUIRE_DONE",
    				     node->debug_id, node->local_strong_refs, node->local_weak_refs);
    			break;
    		}
    		case BC_ATTEMPT_ACQUIRE:
    			pr_err("BC_ATTEMPT_ACQUIRE not supported\n");
    			return -EINVAL;
    		case BC_ACQUIRE_RESULT:
    			pr_err("BC_ACQUIRE_RESULT not supported\n");
    			return -EINVAL;
    
    		case BC_FREE_BUFFER: {
    			binder_uintptr_t data_ptr;
    			struct binder_buffer *buffer;
    
    			if (get_user(data_ptr, (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(binder_uintptr_t);
    
    			buffer = binder_buffer_lookup(proc, data_ptr);
    			if (buffer == NULL) {
    				binder_user_error("%d:%d BC_FREE_BUFFER u%016llx no match\n",
    					proc->pid, thread->pid, (u64)data_ptr);
    				break;
    			}
    			if (!buffer->allow_user_free) {
    				binder_user_error("%d:%d BC_FREE_BUFFER u%016llx matched unreturned buffer\n",
    					proc->pid, thread->pid, (u64)data_ptr);
    				break;
    			}
    			binder_debug(BINDER_DEBUG_FREE_BUFFER,
    				     "%d:%d BC_FREE_BUFFER u%016llx found buffer %d for %s transaction\n",
    				     proc->pid, thread->pid, (u64)data_ptr,
    				     buffer->debug_id,
    				     buffer->transaction ? "active" : "finished");
    
    			if (buffer->transaction) {
    				buffer->transaction->buffer = NULL;
    				buffer->transaction = NULL;
    			}
    			if (buffer->async_transaction && buffer->target_node) {
    				BUG_ON(!buffer->target_node->has_async_transaction);
    				if (list_empty(&buffer->target_node->async_todo))
    					buffer->target_node->has_async_transaction = 0;
    				else
    					list_move_tail(buffer->target_node->async_todo.next, &thread->todo);
    			}
    			trace_binder_transaction_buffer_release(buffer);
    			binder_transaction_buffer_release(proc, buffer, NULL);
    			binder_free_buf(proc, buffer);
    			break;
    		}
    
    		case BC_TRANSACTION:
    		case BC_REPLY: {
    			struct binder_transaction_data tr;
    
    			if (copy_from_user(&tr, ptr, sizeof(tr)))
    				return -EFAULT;
    			ptr += sizeof(tr);
    			binder_transaction(proc, thread, &tr, cmd == BC_REPLY);
    			break;
    		}
    
    		case BC_REGISTER_LOOPER:
    			binder_debug(BINDER_DEBUG_THREADS,
    				     "%d:%d BC_REGISTER_LOOPER\n",
    				     proc->pid, thread->pid);
    			if (thread->looper & BINDER_LOOPER_STATE_ENTERED) {
    				thread->looper |= BINDER_LOOPER_STATE_INVALID;
    				binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called after BC_ENTER_LOOPER\n",
    					proc->pid, thread->pid);
    			} else if (proc->requested_threads == 0) {
    				thread->looper |= BINDER_LOOPER_STATE_INVALID;
    				binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called without request\n",
    					proc->pid, thread->pid);
    			} else {
    				proc->requested_threads--;
    				proc->requested_threads_started++;
    			}
    			thread->looper |= BINDER_LOOPER_STATE_REGISTERED;
    			break;
    		case BC_ENTER_LOOPER:
    			binder_debug(BINDER_DEBUG_THREADS,
    				     "%d:%d BC_ENTER_LOOPER\n",
    				     proc->pid, thread->pid);
    			if (thread->looper & BINDER_LOOPER_STATE_REGISTERED) {
    				thread->looper |= BINDER_LOOPER_STATE_INVALID;
    				binder_user_error("%d:%d ERROR: BC_ENTER_LOOPER called after BC_REGISTER_LOOPER\n",
    					proc->pid, thread->pid);
    			}
    			thread->looper |= BINDER_LOOPER_STATE_ENTERED;
    			break;
    		case BC_EXIT_LOOPER:
    			binder_debug(BINDER_DEBUG_THREADS,
    				     "%d:%d BC_EXIT_LOOPER\n",
    				     proc->pid, thread->pid);
    			thread->looper |= BINDER_LOOPER_STATE_EXITED;
    			break;
    
    		case BC_REQUEST_DEATH_NOTIFICATION:
    		case BC_CLEAR_DEATH_NOTIFICATION: {
    			uint32_t target;
    			binder_uintptr_t cookie;
    			struct binder_ref *ref;
    			struct binder_ref_death *death;
    
    			if (get_user(target, (uint32_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(uint32_t);
    			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(binder_uintptr_t);
    			ref = binder_get_ref(proc, target, false);
    			if (ref == NULL) {
    				binder_user_error("%d:%d %s invalid ref %d\n",
    					proc->pid, thread->pid,
    					cmd == BC_REQUEST_DEATH_NOTIFICATION ?
    					"BC_REQUEST_DEATH_NOTIFICATION" :
    					"BC_CLEAR_DEATH_NOTIFICATION",
    					target);
    				break;
    			}
    
    			binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION,
    				     "%d:%d %s %016llx ref %d desc %d s %d w %d for node %d\n",
    				     proc->pid, thread->pid,
    				     cmd == BC_REQUEST_DEATH_NOTIFICATION ?
    				     "BC_REQUEST_DEATH_NOTIFICATION" :
    				     "BC_CLEAR_DEATH_NOTIFICATION",
    				     (u64)cookie, ref->debug_id, ref->desc,
    				     ref->strong, ref->weak, ref->node->debug_id);
    
    			if (cmd == BC_REQUEST_DEATH_NOTIFICATION) {
    				if (ref->death) {
    					binder_user_error("%d:%d BC_REQUEST_DEATH_NOTIFICATION death notification already set\n",
    						proc->pid, thread->pid);
    					break;
    				}
    				death = kzalloc(sizeof(*death), GFP_KERNEL);
    				if (death == NULL) {
    					thread->return_error = BR_ERROR;
    					binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
    						     "%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n",
    						     proc->pid, thread->pid);
    					break;
    				}
    				binder_stats_created(BINDER_STAT_DEATH);
    				INIT_LIST_HEAD(&death->work.entry);
    				death->cookie = cookie;
    				ref->death = death;
    				if (ref->node->proc == NULL) {
    					ref->death->work.type = BINDER_WORK_DEAD_BINDER;
    					if (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) {
    						list_add_tail(&ref->death->work.entry, &thread->todo);
    					} else {
    						list_add_tail(&ref->death->work.entry, &proc->todo);
    						wake_up_interruptible(&proc->wait);
    					}
    				}
    			} else {
    				if (ref->death == NULL) {
    					binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification not active\n",
    						proc->pid, thread->pid);
    					break;
    				}
    				death = ref->death;
    				if (death->cookie != cookie) {
    					binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch %016llx != %016llx\n",
    						proc->pid, thread->pid,
    						(u64)death->cookie,
    						(u64)cookie);
    					break;
    				}
    				ref->death = NULL;
    				if (list_empty(&death->work.entry)) {
    					death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION;
    					if (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) {
    						list_add_tail(&death->work.entry, &thread->todo);
    					} else {
    						list_add_tail(&death->work.entry, &proc->todo);
    						wake_up_interruptible(&proc->wait);
    					}
    				} else {
    					BUG_ON(death->work.type != BINDER_WORK_DEAD_BINDER);
    					death->work.type = BINDER_WORK_DEAD_BINDER_AND_CLEAR;
    				}
    			}
    		} break;
    		case BC_DEAD_BINDER_DONE: {
    			struct binder_work *w;
    			binder_uintptr_t cookie;
    			struct binder_ref_death *death = NULL;
    
    			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    
    			ptr += sizeof(cookie);
    			list_for_each_entry(w, &proc->delivered_death, entry) {
    				struct binder_ref_death *tmp_death = container_of(w, struct binder_ref_death, work);
    
    				if (tmp_death->cookie == cookie) {
    					death = tmp_death;
    					break;
    				}
    			}
    			binder_debug(BINDER_DEBUG_DEAD_BINDER,
    				     "%d:%d BC_DEAD_BINDER_DONE %016llx found %p\n",
    				     proc->pid, thread->pid, (u64)cookie,
    				     death);
    			if (death == NULL) {
    				binder_user_error("%d:%d BC_DEAD_BINDER_DONE %016llx not found\n",
    					proc->pid, thread->pid, (u64)cookie);
    				break;
    			}
    
    			list_del_init(&death->work.entry);
    			if (death->work.type == BINDER_WORK_DEAD_BINDER_AND_CLEAR) {
    				death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION;
    				if (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) {
    					list_add_tail(&death->work.entry, &thread->todo);
    				} else {
    					list_add_tail(&death->work.entry, &proc->todo);
    					wake_up_interruptible(&proc->wait);
    				}
    			}
    		} break;
    
    		default:
    			pr_err("%d:%d unknown command %d\n",
    			       proc->pid, thread->pid, cmd);
    			return -EINVAL;
    		}
    		*consumed = ptr - buffer;
    	}
    	return 0;
    }
    
    static void binder_stat_br(struct binder_proc *proc,
    			   struct binder_thread *thread, uint32_t cmd)
    {
    	trace_binder_return(cmd);
    	if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.br)) {
    		binder_stats.br[_IOC_NR(cmd)]++;
    		proc->stats.br[_IOC_NR(cmd)]++;
    		thread->stats.br[_IOC_NR(cmd)]++;
    	}
    }
    
    static int binder_has_proc_work(struct binder_proc *proc,
    				struct binder_thread *thread)
    {
    	return !list_empty(&proc->todo) ||
    		(thread->looper & BINDER_LOOPER_STATE_NEED_RETURN);
    }
    
    static int binder_has_thread_work(struct binder_thread *thread)
    {
    	return !list_empty(&thread->todo) || thread->return_error != BR_OK ||
    		(thread->looper & BINDER_LOOPER_STATE_NEED_RETURN);
    }
    
    static int binder_thread_read(struct binder_proc *proc,
    			      struct binder_thread *thread,
    			      binder_uintptr_t binder_buffer, size_t size,
    			      binder_size_t *consumed, int non_block)
    {
    	void __user *buffer = (void __user *)(uintptr_t)binder_buffer;
    	void __user *ptr = buffer + *consumed;
    	void __user *end = buffer + size;
    
    	int ret = 0;
    	int wait_for_proc_work;
    
    	if (*consumed == 0) {
    		if (put_user(BR_NOOP, (uint32_t __user *)ptr))
    			return -EFAULT;
    		ptr += sizeof(uint32_t);
    	}
    
    retry:
    	wait_for_proc_work = thread->transaction_stack == NULL &&
    				list_empty(&thread->todo);
    
    	if (thread->return_error != BR_OK && ptr < end) {
    		if (thread->return_error2 != BR_OK) {
    			if (put_user(thread->return_error2, (uint32_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(uint32_t);
    			binder_stat_br(proc, thread, thread->return_error2);
    			if (ptr == end)
    				goto done;
    			thread->return_error2 = BR_OK;
    		}
    		if (put_user(thread->return_error, (uint32_t __user *)ptr))
    			return -EFAULT;
    		ptr += sizeof(uint32_t);
    		binder_stat_br(proc, thread, thread->return_error);
    		thread->return_error = BR_OK;
    		goto done;
    	}
    
    
    	thread->looper |= BINDER_LOOPER_STATE_WAITING;
    	if (wait_for_proc_work)
    		proc->ready_threads++;
    
    	binder_unlock(__func__);
    
    	trace_binder_wait_for_work(wait_for_proc_work,
    				   !!thread->transaction_stack,
    				   !list_empty(&thread->todo));
    	if (wait_for_proc_work) {
    		if (!(thread->looper & (BINDER_LOOPER_STATE_REGISTERED |
    					BINDER_LOOPER_STATE_ENTERED))) {
    			binder_user_error("%d:%d ERROR: Thread waiting for process work before calling BC_REGISTER_LOOPER or BC_ENTER_LOOPER (state %x)\n",
    				proc->pid, thread->pid, thread->looper);
    			wait_event_interruptible(binder_user_error_wait,
    						 binder_stop_on_user_error < 2);
    		}
    		binder_set_nice(proc->default_priority);
    		if (non_block) {
    			if (!binder_has_proc_work(proc, thread))
    				ret = -EAGAIN;
    		} else
    			ret = wait_event_freezable_exclusive(proc->wait, binder_has_proc_work(proc, thread));
    	} else {
    		if (non_block) {
    			if (!binder_has_thread_work(thread))
    				ret = -EAGAIN;
    		} else
    			ret = wait_event_freezable(thread->wait, binder_has_thread_work(thread));
    	}
    
    	binder_lock(__func__);
    
    	if (wait_for_proc_work)
    		proc->ready_threads--;
    	thread->looper &= ~BINDER_LOOPER_STATE_WAITING;
    
    	if (ret)
    		return ret;
    
    	while (1) {
    		uint32_t cmd;
    		struct binder_transaction_data tr;
    		struct binder_work *w;
    		struct binder_transaction *t = NULL;
    
    		if (!list_empty(&thread->todo)) {
    			w = list_first_entry(&thread->todo, struct binder_work,
    					     entry);
    		} else if (!list_empty(&proc->todo) && wait_for_proc_work) {
    			w = list_first_entry(&proc->todo, struct binder_work,
    					     entry);
    		} else {
    			/* no data added */
    			if (ptr - buffer == 4 &&
    			    !(thread->looper & BINDER_LOOPER_STATE_NEED_RETURN))
    				goto retry;
    			break;
    		}
    
    		if (end - ptr < sizeof(tr) + 4)
    			break;
    
    		switch (w->type) {
    		case BINDER_WORK_TRANSACTION: {
    			t = container_of(w, struct binder_transaction, work);
    		} break;
    		case BINDER_WORK_TRANSACTION_COMPLETE: {
    			cmd = BR_TRANSACTION_COMPLETE;
    			if (put_user(cmd, (uint32_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(uint32_t);
    
    			binder_stat_br(proc, thread, cmd);
    			binder_debug(BINDER_DEBUG_TRANSACTION_COMPLETE,
    				     "%d:%d BR_TRANSACTION_COMPLETE\n",
    				     proc->pid, thread->pid);
    
    			list_del(&w->entry);
    			kfree(w);
    			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
    		} break;
    		case BINDER_WORK_NODE: {
    			struct binder_node *node = container_of(w, struct binder_node, work);
    			uint32_t cmd = BR_NOOP;
    			const char *cmd_name;
    			int strong = node->internal_strong_refs || node->local_strong_refs;
    			int weak = !hlist_empty(&node->refs) || node->local_weak_refs || strong;
    
    			if (weak && !node->has_weak_ref) {
    				cmd = BR_INCREFS;
    				cmd_name = "BR_INCREFS";
    				node->has_weak_ref = 1;
    				node->pending_weak_ref = 1;
    				node->local_weak_refs++;
    			} else if (strong && !node->has_strong_ref) {
    				cmd = BR_ACQUIRE;
    				cmd_name = "BR_ACQUIRE";
    				node->has_strong_ref = 1;
    				node->pending_strong_ref = 1;
    				node->local_strong_refs++;
    			} else if (!strong && node->has_strong_ref) {
    				cmd = BR_RELEASE;
    				cmd_name = "BR_RELEASE";
    				node->has_strong_ref = 0;
    			} else if (!weak && node->has_weak_ref) {
    				cmd = BR_DECREFS;
    				cmd_name = "BR_DECREFS";
    				node->has_weak_ref = 0;
    			}
    			if (cmd != BR_NOOP) {
    				if (put_user(cmd, (uint32_t __user *)ptr))
    					return -EFAULT;
    				ptr += sizeof(uint32_t);
    				if (put_user(node->ptr,
    					     (binder_uintptr_t __user *)ptr))
    					return -EFAULT;
    				ptr += sizeof(binder_uintptr_t);
    				if (put_user(node->cookie,
    					     (binder_uintptr_t __user *)ptr))
    					return -EFAULT;
    				ptr += sizeof(binder_uintptr_t);
    
    				binder_stat_br(proc, thread, cmd);
    				binder_debug(BINDER_DEBUG_USER_REFS,
    					     "%d:%d %s %d u%016llx c%016llx\n",
    					     proc->pid, thread->pid, cmd_name,
    					     node->debug_id,
    					     (u64)node->ptr, (u64)node->cookie);
    			} else {
    				list_del_init(&w->entry);
    				if (!weak && !strong) {
    					binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    						     "%d:%d node %d u%016llx c%016llx deleted\n",
    						     proc->pid, thread->pid,
    						     node->debug_id,
    						     (u64)node->ptr,
    						     (u64)node->cookie);
    					rb_erase(&node->rb_node, &proc->nodes);
    					kfree(node);
    					binder_stats_deleted(BINDER_STAT_NODE);
    				} else {
    					binder_debug(BINDER_DEBUG_INTERNAL_REFS,
    						     "%d:%d node %d u%016llx c%016llx state unchanged\n",
    						     proc->pid, thread->pid,
    						     node->debug_id,
    						     (u64)node->ptr,
    						     (u64)node->cookie);
    				}
    			}
    		} break;
    		case BINDER_WORK_DEAD_BINDER:
    		case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
    		case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: {
    			struct binder_ref_death *death;
    			uint32_t cmd;
    
    			death = container_of(w, struct binder_ref_death, work);
    			if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION)
    				cmd = BR_CLEAR_DEATH_NOTIFICATION_DONE;
    			else
    				cmd = BR_DEAD_BINDER;
    			if (put_user(cmd, (uint32_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(uint32_t);
    			if (put_user(death->cookie,
    				     (binder_uintptr_t __user *)ptr))
    				return -EFAULT;
    			ptr += sizeof(binder_uintptr_t);
    			binder_stat_br(proc, thread, cmd);
    			binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION,
    				     "%d:%d %s %016llx\n",
    				      proc->pid, thread->pid,
    				      cmd == BR_DEAD_BINDER ?
    				      "BR_DEAD_BINDER" :
    				      "BR_CLEAR_DEATH_NOTIFICATION_DONE",
    				      (u64)death->cookie);
    
    			if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION) {
    				list_del(&w->entry);
    				kfree(death);
    				binder_stats_deleted(BINDER_STAT_DEATH);
    			} else
    				list_move(&w->entry, &proc->delivered_death);
    			if (cmd == BR_DEAD_BINDER)
    				goto done; /* DEAD_BINDER notifications can cause transactions */
    		} break;
    		}
    
    		if (!t)
    			continue;
    
    		BUG_ON(t->buffer == NULL);
    		if (t->buffer->target_node) {
    			struct binder_node *target_node = t->buffer->target_node;
    
    			tr.target.ptr = target_node->ptr;
    			tr.cookie =  target_node->cookie;
    			t->saved_priority = task_nice(current);
    			if (t->priority < target_node->min_priority &&
    			    !(t->flags & TF_ONE_WAY))
    				binder_set_nice(t->priority);
    			else if (!(t->flags & TF_ONE_WAY) ||
    				 t->saved_priority > target_node->min_priority)
    				binder_set_nice(target_node->min_priority);
    			cmd = BR_TRANSACTION;
    		} else {
    			tr.target.ptr = 0;
    			tr.cookie = 0;
    			cmd = BR_REPLY;
    		}
    		tr.code = t->code;
    		tr.flags = t->flags;
    		tr.sender_euid = from_kuid(current_user_ns(), t->sender_euid);
    
    		if (t->from) {
    			struct task_struct *sender = t->from->proc->tsk;
    
    			tr.sender_pid = task_tgid_nr_ns(sender,
    							task_active_pid_ns(current));
    		} else {
    			tr.sender_pid = 0;
    		}
    
    		tr.data_size = t->buffer->data_size;
    		tr.offsets_size = t->buffer->offsets_size;
    		tr.data.ptr.buffer = (binder_uintptr_t)(
    					(uintptr_t)t->buffer->data +
    					proc->user_buffer_offset);
    		tr.data.ptr.offsets = tr.data.ptr.buffer +
    					ALIGN(t->buffer->data_size,
    					    sizeof(void *));
    
    		if (put_user(cmd, (uint32_t __user *)ptr))
    			return -EFAULT;
    		ptr += sizeof(uint32_t);
    		if (copy_to_user(ptr, &tr, sizeof(tr)))
    			return -EFAULT;
    		ptr += sizeof(tr);
    
    		trace_binder_transaction_received(t);
    		binder_stat_br(proc, thread, cmd);
    		binder_debug(BINDER_DEBUG_TRANSACTION,
    			     "%d:%d %s %d %d:%d, cmd %d size %zd-%zd ptr %016llx-%016llx\n",
    			     proc->pid, thread->pid,
    			     (cmd == BR_TRANSACTION) ? "BR_TRANSACTION" :
    			     "BR_REPLY",
    			     t->debug_id, t->from ? t->from->proc->pid : 0,
    			     t->from ? t->from->pid : 0, cmd,
    			     t->buffer->data_size, t->buffer->offsets_size,
    			     (u64)tr.data.ptr.buffer, (u64)tr.data.ptr.offsets);
    
    		list_del(&t->work.entry);
    		t->buffer->allow_user_free = 1;
    		if (cmd == BR_TRANSACTION && !(t->flags & TF_ONE_WAY)) {
    			t->to_parent = thread->transaction_stack;
    			t->to_thread = thread;
    			thread->transaction_stack = t;
    		} else {
    			t->buffer->transaction = NULL;
    			kfree(t);
    			binder_stats_deleted(BINDER_STAT_TRANSACTION);
    		}
    		break;
    	}
    
    done:
    
    	*consumed = ptr - buffer;
    	if (proc->requested_threads + proc->ready_threads == 0 &&
    	    proc->requested_threads_started < proc->max_threads &&
    	    (thread->looper & (BINDER_LOOPER_STATE_REGISTERED |
    	     BINDER_LOOPER_STATE_ENTERED)) /* the user-space code fails to */
    	     /*spawn a new thread if we leave this out */) {
    		proc->requested_threads++;
    		binder_debug(BINDER_DEBUG_THREADS,
    			     "%d:%d BR_SPAWN_LOOPER\n",
    			     proc->pid, thread->pid);
    		if (put_user(BR_SPAWN_LOOPER, (uint32_t __user *)buffer))
    			return -EFAULT;
    		binder_stat_br(proc, thread, BR_SPAWN_LOOPER);
    	}
    	return 0;
    }
    
    static void binder_release_work(struct list_head *list)
    {
    	struct binder_work *w;
    
    	while (!list_empty(list)) {
    		w = list_first_entry(list, struct binder_work, entry);
    		list_del_init(&w->entry);
    		switch (w->type) {
    		case BINDER_WORK_TRANSACTION: {
    			struct binder_transaction *t;
    
    			t = container_of(w, struct binder_transaction, work);
    			if (t->buffer->target_node &&
    			    !(t->flags & TF_ONE_WAY)) {
    				binder_send_failed_reply(t, BR_DEAD_REPLY);
    			} else {
    				binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
    					"undelivered transaction %d\n",
    					t->debug_id);
    				t->buffer->transaction = NULL;
    				kfree(t);
    				binder_stats_deleted(BINDER_STAT_TRANSACTION);
    			}
    		} break;
    		case BINDER_WORK_TRANSACTION_COMPLETE: {
    			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
    				"undelivered TRANSACTION_COMPLETE\n");
    			kfree(w);
    			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
    		} break;
    		case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
    		case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: {
    			struct binder_ref_death *death;
    
    			death = container_of(w, struct binder_ref_death, work);
    			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
    				"undelivered death notification, %016llx\n",
    				(u64)death->cookie);
    			kfree(death);
    			binder_stats_deleted(BINDER_STAT_DEATH);
    		} break;
    		default:
    			pr_err("unexpected work type, %d, not freed\n",
    			       w->type);
    			break;
    		}
    	}
    
    }
    
    static struct binder_thread *binder_get_thread(struct binder_proc *proc)
    {
    	struct binder_thread *thread = NULL;
    	struct rb_node *parent = NULL;
    	struct rb_node **p = &proc->threads.rb_node;
    
    	while (*p) {
    		parent = *p;
    		thread = rb_entry(parent, struct binder_thread, rb_node);
    
    		if (current->pid < thread->pid)
    			p = &(*p)->rb_left;
    		else if (current->pid > thread->pid)
    			p = &(*p)->rb_right;
    		else
    			break;
    	}
    	if (*p == NULL) {
    		thread = kzalloc(sizeof(*thread), GFP_KERNEL);
    		if (thread == NULL)
    			return NULL;
    		binder_stats_created(BINDER_STAT_THREAD);
    		thread->proc = proc;
    		thread->pid = current->pid;
    		init_waitqueue_head(&thread->wait);
    		INIT_LIST_HEAD(&thread->todo);
    		rb_link_node(&thread->rb_node, parent, p);
    		rb_insert_color(&thread->rb_node, &proc->threads);
    		thread->looper |= BINDER_LOOPER_STATE_NEED_RETURN;
    		thread->return_error = BR_OK;
    		thread->return_error2 = BR_OK;
    	}
    	return thread;
    }
    
    static int binder_free_thread(struct binder_proc *proc,
    			      struct binder_thread *thread)
    {
    	struct binder_transaction *t;
    	struct binder_transaction *send_reply = NULL;
    	int active_transactions = 0;
    
    	rb_erase(&thread->rb_node, &proc->threads);
    	t = thread->transaction_stack;
    	if (t && t->to_thread == thread)
    		send_reply = t;
    	while (t) {
    		active_transactions++;
    		binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
    			     "release %d:%d transaction %d %s, still active\n",
    			      proc->pid, thread->pid,
    			     t->debug_id,
    			     (t->to_thread == thread) ? "in" : "out");
    
    		if (t->to_thread == thread) {
    			t->to_proc = NULL;
    			t->to_thread = NULL;
    			if (t->buffer) {
    				t->buffer->transaction = NULL;
    				t->buffer = NULL;
    			}
    			t = t->to_parent;
    		} else if (t->from == thread) {
    			t->from = NULL;
    			t = t->from_parent;
    		} else
    			BUG();
    	}
    	if (send_reply)
    		binder_send_failed_reply(send_reply, BR_DEAD_REPLY);
    	binder_release_work(&thread->todo);
    	kfree(thread);
    	binder_stats_deleted(BINDER_STAT_THREAD);
    	return active_transactions;
    }
    
    static unsigned int binder_poll(struct file *filp,
    				struct poll_table_struct *wait)
    {
    	struct binder_proc *proc = filp->private_data;
    	struct binder_thread *thread = NULL;
    	int wait_for_proc_work;
    
    	binder_lock(__func__);
    
    	thread = binder_get_thread(proc);
    
    	wait_for_proc_work = thread->transaction_stack == NULL &&
    		list_empty(&thread->todo) && thread->return_error == BR_OK;
    
    	binder_unlock(__func__);
    
    	if (wait_for_proc_work) {
    		if (binder_has_proc_work(proc, thread))
    			return POLLIN;
    		poll_wait(filp, &proc->wait, wait);
    		if (binder_has_proc_work(proc, thread))
    			return POLLIN;
    	} else {
    		if (binder_has_thread_work(thread))
    			return POLLIN;
    		poll_wait(filp, &thread->wait, wait);
    		if (binder_has_thread_work(thread))
    			return POLLIN;
    	}
    	return 0;
    }
    
    static int binder_ioctl_write_read(struct file *filp,
    				unsigned int cmd, unsigned long arg,
    				struct binder_thread *thread)
    {
    	int ret = 0;
    	struct binder_proc *proc = filp->private_data;
    	unsigned int size = _IOC_SIZE(cmd);
    	void __user *ubuf = (void __user *)arg;
    	struct binder_write_read bwr;
    
    	if (size != sizeof(struct binder_write_read)) {
    		ret = -EINVAL;
    		goto out;
    	}
    	if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {
    		ret = -EFAULT;
    		goto out;
    	}
    	binder_debug(BINDER_DEBUG_READ_WRITE,
    		     "%d:%d write %lld at %016llx, read %lld at %016llx\n",
    		     proc->pid, thread->pid,
    		     (u64)bwr.write_size, (u64)bwr.write_buffer,
    		     (u64)bwr.read_size, (u64)bwr.read_buffer);
    
    	if (bwr.write_size > 0) {
    		ret = binder_thread_write(proc, thread,
    					  bwr.write_buffer,
    					  bwr.write_size,
    					  &bwr.write_consumed);
    		trace_binder_write_done(ret);
    		if (ret < 0) {
    			bwr.read_consumed = 0;
    			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
    				ret = -EFAULT;
    			goto out;
    		}
    	}
    	if (bwr.read_size > 0) {
    		ret = binder_thread_read(proc, thread, bwr.read_buffer,
    					 bwr.read_size,
    					 &bwr.read_consumed,
    					 filp->f_flags & O_NONBLOCK);
    		trace_binder_read_done(ret);
    		if (!list_empty(&proc->todo))
    			wake_up_interruptible(&proc->wait);
    		if (ret < 0) {
    			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
    				ret = -EFAULT;
    			goto out;
    		}
    	}
    	binder_debug(BINDER_DEBUG_READ_WRITE,
    		     "%d:%d wrote %lld of %lld, read return %lld of %lld\n",
    		     proc->pid, thread->pid,
    		     (u64)bwr.write_consumed, (u64)bwr.write_size,
    		     (u64)bwr.read_consumed, (u64)bwr.read_size);
    	if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
    		ret = -EFAULT;
    		goto out;
    	}
    out:
    	return ret;
    }
    
    static int binder_ioctl_set_ctx_mgr(struct file *filp)
    {
    	int ret = 0;
    	struct binder_proc *proc = filp->private_data;
    	struct binder_context *context = proc->context;
    
    	kuid_t curr_euid = current_euid();
    
    	if (context->binder_context_mgr_node) {
    		pr_err("BINDER_SET_CONTEXT_MGR already set\n");
    		ret = -EBUSY;
    		goto out;
    	}
    	ret = security_binder_set_context_mgr(proc->tsk);
    	if (ret < 0)
    		goto out;
    	if (uid_valid(context->binder_context_mgr_uid)) {
    		if (!uid_eq(context->binder_context_mgr_uid, curr_euid)) {
    			pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
    			       from_kuid(&init_user_ns, curr_euid),
    			       from_kuid(&init_user_ns,
    					 context->binder_context_mgr_uid));
    			ret = -EPERM;
    			goto out;
    		}
    	} else {
    		context->binder_context_mgr_uid = curr_euid;
    	}
    	context->binder_context_mgr_node = binder_new_node(proc, 0, 0);
    	if (!context->binder_context_mgr_node) {
    		ret = -ENOMEM;
    		goto out;
    	}
    	context->binder_context_mgr_node->local_weak_refs++;
    	context->binder_context_mgr_node->local_strong_refs++;
    	context->binder_context_mgr_node->has_strong_ref = 1;
    	context->binder_context_mgr_node->has_weak_ref = 1;
    out:
    	return ret;
    }
    
    static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
    {
    	int ret;
    	struct binder_proc *proc = filp->private_data;
    	struct binder_thread *thread;
    	unsigned int size = _IOC_SIZE(cmd);
    	void __user *ubuf = (void __user *)arg;
    
    	/*pr_info("binder_ioctl: %d:%d %x %lx\n",
    			proc->pid, current->pid, cmd, arg);*/
    
    	if (unlikely(current->mm != proc->vma_vm_mm)) {
    		pr_err("current mm mismatch proc mm\n");
    		return -EINVAL;
    	}
    	trace_binder_ioctl(cmd, arg);
    
    	ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
    	if (ret)
    		goto err_unlocked;
    
    	binder_lock(__func__);
    	thread = binder_get_thread(proc);
    	if (thread == NULL) {
    		ret = -ENOMEM;
    		goto err;
    	}
    
    	switch (cmd) {
    	case BINDER_WRITE_READ:
    		ret = binder_ioctl_write_read(filp, cmd, arg, thread);
    		if (ret)
    			goto err;
    		break;
    	case BINDER_SET_MAX_THREADS:
    		if (copy_from_user(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
    			ret = -EINVAL;
    			goto err;
    		}
    		break;
    	case BINDER_SET_CONTEXT_MGR:
    		ret = binder_ioctl_set_ctx_mgr(filp);
    		if (ret)
    			goto err;
    		break;
    	case BINDER_THREAD_EXIT:
    		binder_debug(BINDER_DEBUG_THREADS, "%d:%d exit\n",
    			     proc->pid, thread->pid);
    		binder_free_thread(proc, thread);
    		thread = NULL;
    		break;
    	case BINDER_VERSION: {
    		struct binder_version __user *ver = ubuf;
    
    		if (size != sizeof(struct binder_version)) {
    			ret = -EINVAL;
    			goto err;
    		}
    		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
    			     &ver->protocol_version)) {
    			ret = -EINVAL;
    			goto err;
    		}
    		break;
    	}
    	default:
    		ret = -EINVAL;
    		goto err;
    	}
    	ret = 0;
    err:
    	if (thread)
    		thread->looper &= ~BINDER_LOOPER_STATE_NEED_RETURN;
    	binder_unlock(__func__);
    	wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
    	if (ret && ret != -ERESTARTSYS)
    		pr_info("%d:%d ioctl %x %lx returned %d\n", proc->pid, current->pid, cmd, arg, ret);
    err_unlocked:
    	trace_binder_ioctl_done(ret);
    	return ret;
    }
    
    static void binder_vma_open(struct vm_area_struct *vma)
    {
    	struct binder_proc *proc = vma->vm_private_data;
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
    		     "%d open vm area %lx-%lx (%ld K) vma %lx pagep %lx\n",
    		     proc->pid, vma->vm_start, vma->vm_end,
    		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
    		     (unsigned long)pgprot_val(vma->vm_page_prot));
    }
    
    static void binder_vma_close(struct vm_area_struct *vma)
    {
    	struct binder_proc *proc = vma->vm_private_data;
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
    		     "%d close vm area %lx-%lx (%ld K) vma %lx pagep %lx\n",
    		     proc->pid, vma->vm_start, vma->vm_end,
    		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
    		     (unsigned long)pgprot_val(vma->vm_page_prot));
    	proc->vma = NULL;
    	proc->vma_vm_mm = NULL;
    	binder_defer_work(proc, BINDER_DEFERRED_PUT_FILES);
    }
    
    static int binder_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
    {
    	return VM_FAULT_SIGBUS;
    }
    
    static const struct vm_operations_struct binder_vm_ops = {
    	.open = binder_vma_open,
    	.close = binder_vma_close,
    	.fault = binder_vm_fault,
    };
    
    static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
    {
    	int ret;
    	struct vm_struct *area;
    	struct binder_proc *proc = filp->private_data;
    	const char *failure_string;
    	struct binder_buffer *buffer;
    
    	if (proc->tsk != current)
    		return -EINVAL;
    
    	if ((vma->vm_end - vma->vm_start) > SZ_4M)
    		vma->vm_end = vma->vm_start + SZ_4M;
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
    		     "binder_mmap: %d %lx-%lx (%ld K) vma %lx pagep %lx\n",
    		     proc->pid, vma->vm_start, vma->vm_end,
    		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
    		     (unsigned long)pgprot_val(vma->vm_page_prot));
    
    	if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
    		ret = -EPERM;
    		failure_string = "bad vm_flags";
    		goto err_bad_arg;
    	}
    	vma->vm_flags = (vma->vm_flags | VM_DONTCOPY) & ~VM_MAYWRITE;
    
    	mutex_lock(&binder_mmap_lock);
    	if (proc->buffer) {
    		ret = -EBUSY;
    		failure_string = "already mapped";
    		goto err_already_mapped;
    	}
    
    	area = get_vm_area(vma->vm_end - vma->vm_start, VM_IOREMAP);
    	if (area == NULL) {
    		ret = -ENOMEM;
    		failure_string = "get_vm_area";
    		goto err_get_vm_area_failed;
    	}
    	proc->buffer = area->addr;
    	proc->user_buffer_offset = vma->vm_start - (uintptr_t)proc->buffer;
    	mutex_unlock(&binder_mmap_lock);
    
    #ifdef CONFIG_CPU_CACHE_VIPT
    	if (cache_is_vipt_aliasing()) {
    		while (CACHE_COLOUR((vma->vm_start ^ (uint32_t)proc->buffer))) {
    			pr_info("binder_mmap: %d %lx-%lx maps %p bad alignment\n", proc->pid, vma->vm_start, vma->vm_end, proc->buffer);
    			vma->vm_start += PAGE_SIZE;
    		}
    	}
    #endif
    	proc->pages = kzalloc(sizeof(proc->pages[0]) * ((vma->vm_end - vma->vm_start) / PAGE_SIZE), GFP_KERNEL);
    	if (proc->pages == NULL) {
    		ret = -ENOMEM;
    		failure_string = "alloc page array";
    		goto err_alloc_pages_failed;
    	}
    	proc->buffer_size = vma->vm_end - vma->vm_start;
    
    	vma->vm_ops = &binder_vm_ops;
    	vma->vm_private_data = proc;
    
    	if (binder_update_page_range(proc, 1, proc->buffer, proc->buffer + PAGE_SIZE, vma)) {
    		ret = -ENOMEM;
    		failure_string = "alloc small buf";
    		goto err_alloc_small_buf_failed;
    	}
    	buffer = proc->buffer;
    	INIT_LIST_HEAD(&proc->buffers);
    	list_add(&buffer->entry, &proc->buffers);
    	buffer->free = 1;
    	binder_insert_free_buffer(proc, buffer);
    	proc->free_async_space = proc->buffer_size / 2;
    	barrier();
    	proc->files = get_files_struct(current);
    	proc->vma = vma;
    	proc->vma_vm_mm = vma->vm_mm;
    
    	/*pr_info("binder_mmap: %d %lx-%lx maps %p\n",
    		 proc->pid, vma->vm_start, vma->vm_end, proc->buffer);*/
    	return 0;
    
    err_alloc_small_buf_failed:
    	kfree(proc->pages);
    	proc->pages = NULL;
    err_alloc_pages_failed:
    	mutex_lock(&binder_mmap_lock);
    	vfree(proc->buffer);
    	proc->buffer = NULL;
    err_get_vm_area_failed:
    err_already_mapped:
    	mutex_unlock(&binder_mmap_lock);
    err_bad_arg:
    	pr_err("binder_mmap: %d %lx-%lx %s failed %d\n",
    	       proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
    	return ret;
    }
    
    static int binder_open(struct inode *nodp, struct file *filp)
    {
    	struct binder_proc *proc;
    	struct binder_device *binder_dev;
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE, "binder_open: %d:%d\n",
    		     current->group_leader->pid, current->pid);
    
    	proc = kzalloc(sizeof(*proc), GFP_KERNEL);
    	if (proc == NULL)
    		return -ENOMEM;
    	get_task_struct(current);
    	proc->tsk = current;
    	proc->vma_vm_mm = current->mm;
    	INIT_LIST_HEAD(&proc->todo);
    	init_waitqueue_head(&proc->wait);
    	proc->default_priority = task_nice(current);
    	binder_dev = container_of(filp->private_data, struct binder_device,
    				  miscdev);
    	proc->context = &binder_dev->context;
    
    	binder_lock(__func__);
    
    	binder_stats_created(BINDER_STAT_PROC);
    	hlist_add_head(&proc->proc_node, &binder_procs);
    	proc->pid = current->group_leader->pid;
    	INIT_LIST_HEAD(&proc->delivered_death);
    	filp->private_data = proc;
    
    	binder_unlock(__func__);
    
    	if (binder_debugfs_dir_entry_proc) {
    		char strbuf[11];
    
    		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
    		/*
    		 * proc debug entries are shared between contexts, so
    		 * this will fail if the process tries to open the driver
    		 * again with a different context. The priting code will
    		 * anyway print all contexts that a given PID has, so this
    		 * is not a problem.
    		 */
    		proc->debugfs_entry = debugfs_create_file(strbuf, S_IRUGO,
    			binder_debugfs_dir_entry_proc,
    			(void *)(unsigned long)proc->pid,
    			&binder_proc_fops);
    	}
    
    	return 0;
    }
    
    static int binder_flush(struct file *filp, fl_owner_t id)
    {
    	struct binder_proc *proc = filp->private_data;
    
    	binder_defer_work(proc, BINDER_DEFERRED_FLUSH);
    
    	return 0;
    }
    
    static void binder_deferred_flush(struct binder_proc *proc)
    {
    	struct rb_node *n;
    	int wake_count = 0;
    
    	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) {
    		struct binder_thread *thread = rb_entry(n, struct binder_thread, rb_node);
    
    		thread->looper |= BINDER_LOOPER_STATE_NEED_RETURN;
    		if (thread->looper & BINDER_LOOPER_STATE_WAITING) {
    			wake_up_interruptible(&thread->wait);
    			wake_count++;
    		}
    	}
    	wake_up_interruptible_all(&proc->wait);
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
    		     "binder_flush: %d woke %d threads\n", proc->pid,
    		     wake_count);
    }
    
    static int binder_release(struct inode *nodp, struct file *filp)
    {
    	struct binder_proc *proc = filp->private_data;
    
    	debugfs_remove(proc->debugfs_entry);
    	binder_defer_work(proc, BINDER_DEFERRED_RELEASE);
    
    	return 0;
    }
    
    static int binder_node_release(struct binder_node *node, int refs)
    {
    	struct binder_ref *ref;
    	int death = 0;
    
    	list_del_init(&node->work.entry);
    	binder_release_work(&node->async_todo);
    
    	if (hlist_empty(&node->refs)) {
    		kfree(node);
    		binder_stats_deleted(BINDER_STAT_NODE);
    
    		return refs;
    	}
    
    	node->proc = NULL;
    	node->local_strong_refs = 0;
    	node->local_weak_refs = 0;
    	hlist_add_head(&node->dead_node, &binder_dead_nodes);
    
    	hlist_for_each_entry(ref, &node->refs, node_entry) {
    		refs++;
    
    		if (!ref->death)
    			continue;
    
    		death++;
    
    		if (list_empty(&ref->death->work.entry)) {
    			ref->death->work.type = BINDER_WORK_DEAD_BINDER;
    			list_add_tail(&ref->death->work.entry,
    				      &ref->proc->todo);
    			wake_up_interruptible(&ref->proc->wait);
    		} else
    			BUG();
    	}
    
    	binder_debug(BINDER_DEBUG_DEAD_BINDER,
    		     "node %d now dead, refs %d, death %d\n",
    		     node->debug_id, refs, death);
    
    	return refs;
    }
    
    static void binder_deferred_release(struct binder_proc *proc)
    {
    	struct binder_transaction *t;
    	struct binder_context *context = proc->context;
    	struct rb_node *n;
    	int threads, nodes, incoming_refs, outgoing_refs, buffers,
    		active_transactions, page_count;
    
    	BUG_ON(proc->vma);
    	BUG_ON(proc->files);
    
    	hlist_del(&proc->proc_node);
    
    	if (context->binder_context_mgr_node &&
    	    context->binder_context_mgr_node->proc == proc) {
    		binder_debug(BINDER_DEBUG_DEAD_BINDER,
    			     "%s: %d context_mgr_node gone\n",
    			     __func__, proc->pid);
    		context->binder_context_mgr_node = NULL;
    	}
    
    	threads = 0;
    	active_transactions = 0;
    	while ((n = rb_first(&proc->threads))) {
    		struct binder_thread *thread;
    
    		thread = rb_entry(n, struct binder_thread, rb_node);
    		threads++;
    		active_transactions += binder_free_thread(proc, thread);
    	}
    
    	nodes = 0;
    	incoming_refs = 0;
    	while ((n = rb_first(&proc->nodes))) {
    		struct binder_node *node;
    
    		node = rb_entry(n, struct binder_node, rb_node);
    		nodes++;
    		rb_erase(&node->rb_node, &proc->nodes);
    		incoming_refs = binder_node_release(node, incoming_refs);
    	}
    
    	outgoing_refs = 0;
    	while ((n = rb_first(&proc->refs_by_desc))) {
    		struct binder_ref *ref;
    
    		ref = rb_entry(n, struct binder_ref, rb_node_desc);
    		outgoing_refs++;
    		binder_delete_ref(ref);
    	}
    
    	binder_release_work(&proc->todo);
    	binder_release_work(&proc->delivered_death);
    
    	buffers = 0;
    	while ((n = rb_first(&proc->allocated_buffers))) {
    		struct binder_buffer *buffer;
    
    		buffer = rb_entry(n, struct binder_buffer, rb_node);
    
    		t = buffer->transaction;
    		if (t) {
    			t->buffer = NULL;
    			buffer->transaction = NULL;
    			pr_err("release proc %d, transaction %d, not freed\n",
    			       proc->pid, t->debug_id);
    			/*BUG();*/
    		}
    
    		binder_free_buf(proc, buffer);
    		buffers++;
    	}
    
    	binder_stats_deleted(BINDER_STAT_PROC);
    
    	page_count = 0;
    	if (proc->pages) {
    		int i;
    
    		for (i = 0; i < proc->buffer_size / PAGE_SIZE; i++) {
    			void *page_addr;
    
    			if (!proc->pages[i])
    				continue;
    
    			page_addr = proc->buffer + i * PAGE_SIZE;
    			binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
    				     "%s: %d: page %d at %p not freed\n",
    				     __func__, proc->pid, i, page_addr);
    			unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
    			__free_page(proc->pages[i]);
    			page_count++;
    		}
    		kfree(proc->pages);
    		vfree(proc->buffer);
    	}
    
    	put_task_struct(proc->tsk);
    
    	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
    		     "%s: %d threads %d, nodes %d (ref %d), refs %d, active transactions %d, buffers %d, pages %d\n",
    		     __func__, proc->pid, threads, nodes, incoming_refs,
    		     outgoing_refs, active_transactions, buffers, page_count);
    
    	kfree(proc);
    }
    
    static void binder_deferred_func(struct work_struct *work)
    {
    	struct binder_proc *proc;
    	struct files_struct *files;
    
    	int defer;
    
    	do {
    		binder_lock(__func__);
    		mutex_lock(&binder_deferred_lock);
    		if (!hlist_empty(&binder_deferred_list)) {
    			proc = hlist_entry(binder_deferred_list.first,
    					struct binder_proc, deferred_work_node);
    			hlist_del_init(&proc->deferred_work_node);
    			defer = proc->deferred_work;
    			proc->deferred_work = 0;
    		} else {
    			proc = NULL;
    			defer = 0;
    		}
    		mutex_unlock(&binder_deferred_lock);
    
    		files = NULL;
    		if (defer & BINDER_DEFERRED_PUT_FILES) {
    			files = proc->files;
    			if (files)
    				proc->files = NULL;
    		}
    
    		if (defer & BINDER_DEFERRED_FLUSH)
    			binder_deferred_flush(proc);
    
    		if (defer & BINDER_DEFERRED_RELEASE)
    			binder_deferred_release(proc); /* frees proc */
    
    		binder_unlock(__func__);
    		if (files)
    			put_files_struct(files);
    	} while (proc);
    }
    static DECLARE_WORK(binder_deferred_work, binder_deferred_func);
    
    static void
    binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer)
    {
    	mutex_lock(&binder_deferred_lock);
    	proc->deferred_work |= defer;
    	if (hlist_unhashed(&proc->deferred_work_node)) {
    		hlist_add_head(&proc->deferred_work_node,
    				&binder_deferred_list);
    		schedule_work(&binder_deferred_work);
    	}
    	mutex_unlock(&binder_deferred_lock);
    }
    
    static void print_binder_transaction(struct seq_file *m, const char *prefix,
    				     struct binder_transaction *t)
    {
    	seq_printf(m,
    		   "%s %d: %p from %d:%d to %d:%d code %x flags %x pri %ld r%d",
    		   prefix, t->debug_id, t,
    		   t->from ? t->from->proc->pid : 0,
    		   t->from ? t->from->pid : 0,
    		   t->to_proc ? t->to_proc->pid : 0,
    		   t->to_thread ? t->to_thread->pid : 0,
    		   t->code, t->flags, t->priority, t->need_reply);
    	if (t->buffer == NULL) {
    		seq_puts(m, " buffer free\n");
    		return;
    	}
    	if (t->buffer->target_node)
    		seq_printf(m, " node %d",
    			   t->buffer->target_node->debug_id);
    	seq_printf(m, " size %zd:%zd data %p\n",
    		   t->buffer->data_size, t->buffer->offsets_size,
    		   t->buffer->data);
    }
    
    static void print_binder_buffer(struct seq_file *m, const char *prefix,
    				struct binder_buffer *buffer)
    {
    	seq_printf(m, "%s %d: %p size %zd:%zd %s\n",
    		   prefix, buffer->debug_id, buffer->data,
    		   buffer->data_size, buffer->offsets_size,
    		   buffer->transaction ? "active" : "delivered");
    }
    
    static void print_binder_work(struct seq_file *m, const char *prefix,
    			      const char *transaction_prefix,
    			      struct binder_work *w)
    {
    	struct binder_node *node;
    	struct binder_transaction *t;
    
    	switch (w->type) {
    	case BINDER_WORK_TRANSACTION:
    		t = container_of(w, struct binder_transaction, work);
    		print_binder_transaction(m, transaction_prefix, t);
    		break;
    	case BINDER_WORK_TRANSACTION_COMPLETE:
    		seq_printf(m, "%stransaction complete\n", prefix);
    		break;
    	case BINDER_WORK_NODE:
    		node = container_of(w, struct binder_node, work);
    		seq_printf(m, "%snode work %d: u%016llx c%016llx\n",
    			   prefix, node->debug_id,
    			   (u64)node->ptr, (u64)node->cookie);
    		break;
    	case BINDER_WORK_DEAD_BINDER:
    		seq_printf(m, "%shas dead binder\n", prefix);
    		break;
    	case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
    		seq_printf(m, "%shas cleared dead binder\n", prefix);
    		break;
    	case BINDER_WORK_CLEAR_DEATH_NOTIFICATION:
    		seq_printf(m, "%shas cleared death notification\n", prefix);
    		break;
    	default:
    		seq_printf(m, "%sunknown work: type %d\n", prefix, w->type);
    		break;
    	}
    }
    
    static void print_binder_thread(struct seq_file *m,
    				struct binder_thread *thread,
    				int print_always)
    {
    	struct binder_transaction *t;
    	struct binder_work *w;
    	size_t start_pos = m->count;
    	size_t header_pos;
    
    	seq_printf(m, "  thread %d: l %02x\n", thread->pid, thread->looper);
    	header_pos = m->count;
    	t = thread->transaction_stack;
    	while (t) {
    		if (t->from == thread) {
    			print_binder_transaction(m,
    						 "    outgoing transaction", t);
    			t = t->from_parent;
    		} else if (t->to_thread == thread) {
    			print_binder_transaction(m,
    						 "    incoming transaction", t);
    			t = t->to_parent;
    		} else {
    			print_binder_transaction(m, "    bad transaction", t);
    			t = NULL;
    		}
    	}
    	list_for_each_entry(w, &thread->todo, entry) {
    		print_binder_work(m, "    ", "    pending transaction", w);
    	}
    	if (!print_always && m->count == header_pos)
    		m->count = start_pos;
    }
    
    static void print_binder_node(struct seq_file *m, struct binder_node *node)
    {
    	struct binder_ref *ref;
    	struct binder_work *w;
    	int count;
    
    	count = 0;
    	hlist_for_each_entry(ref, &node->refs, node_entry)
    		count++;
    
    	seq_printf(m, "  node %d: u%016llx c%016llx hs %d hw %d ls %d lw %d is %d iw %d",
    		   node->debug_id, (u64)node->ptr, (u64)node->cookie,
    		   node->has_strong_ref, node->has_weak_ref,
    		   node->local_strong_refs, node->local_weak_refs,
    		   node->internal_strong_refs, count);
    	if (count) {
    		seq_puts(m, " proc");
    		hlist_for_each_entry(ref, &node->refs, node_entry)
    			seq_printf(m, " %d", ref->proc->pid);
    	}
    	seq_puts(m, "\n");
    	list_for_each_entry(w, &node->async_todo, entry)
    		print_binder_work(m, "    ",
    				  "    pending async transaction", w);
    }
    
    static void print_binder_ref(struct seq_file *m, struct binder_ref *ref)
    {
    	seq_printf(m, "  ref %d: desc %d %snode %d s %d w %d d %p\n",
    		   ref->debug_id, ref->desc, ref->node->proc ? "" : "dead ",
    		   ref->node->debug_id, ref->strong, ref->weak, ref->death);
    }
    
    static void print_binder_proc(struct seq_file *m,
    			      struct binder_proc *proc, int print_all)
    {
    	struct binder_work *w;
    	struct rb_node *n;
    	size_t start_pos = m->count;
    	size_t header_pos;
    
    	seq_printf(m, "proc %d\n", proc->pid);
    	seq_printf(m, "context %s\n", proc->context->name);
    	header_pos = m->count;
    
    	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n))
    		print_binder_thread(m, rb_entry(n, struct binder_thread,
    						rb_node), print_all);
    	for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) {
    		struct binder_node *node = rb_entry(n, struct binder_node,
    						    rb_node);
    		if (print_all || node->has_async_transaction)
    			print_binder_node(m, node);
    	}
    	if (print_all) {
    		for (n = rb_first(&proc->refs_by_desc);
    		     n != NULL;
    		     n = rb_next(n))
    			print_binder_ref(m, rb_entry(n, struct binder_ref,
    						     rb_node_desc));
    	}
    	for (n = rb_first(&proc->allocated_buffers); n != NULL; n = rb_next(n))
    		print_binder_buffer(m, "  buffer",
    				    rb_entry(n, struct binder_buffer, rb_node));
    	list_for_each_entry(w, &proc->todo, entry)
    		print_binder_work(m, "  ", "  pending transaction", w);
    	list_for_each_entry(w, &proc->delivered_death, entry) {
    		seq_puts(m, "  has delivered dead binder\n");
    		break;
    	}
    	if (!print_all && m->count == header_pos)
    		m->count = start_pos;
    }
    
    static const char * const binder_return_strings[] = {
    	"BR_ERROR",
    	"BR_OK",
    	"BR_TRANSACTION",
    	"BR_REPLY",
    	"BR_ACQUIRE_RESULT",
    	"BR_DEAD_REPLY",
    	"BR_TRANSACTION_COMPLETE",
    	"BR_INCREFS",
    	"BR_ACQUIRE",
    	"BR_RELEASE",
    	"BR_DECREFS",
    	"BR_ATTEMPT_ACQUIRE",
    	"BR_NOOP",
    	"BR_SPAWN_LOOPER",
    	"BR_FINISHED",
    	"BR_DEAD_BINDER",
    	"BR_CLEAR_DEATH_NOTIFICATION_DONE",
    	"BR_FAILED_REPLY"
    };
    
    static const char * const binder_command_strings[] = {
    	"BC_TRANSACTION",
    	"BC_REPLY",
    	"BC_ACQUIRE_RESULT",
    	"BC_FREE_BUFFER",
    	"BC_INCREFS",
    	"BC_ACQUIRE",
    	"BC_RELEASE",
    	"BC_DECREFS",
    	"BC_INCREFS_DONE",
    	"BC_ACQUIRE_DONE",
    	"BC_ATTEMPT_ACQUIRE",
    	"BC_REGISTER_LOOPER",
    	"BC_ENTER_LOOPER",
    	"BC_EXIT_LOOPER",
    	"BC_REQUEST_DEATH_NOTIFICATION",
    	"BC_CLEAR_DEATH_NOTIFICATION",
    	"BC_DEAD_BINDER_DONE"
    };
    
    static const char * const binder_objstat_strings[] = {
    	"proc",
    	"thread",
    	"node",
    	"ref",
    	"death",
    	"transaction",
    	"transaction_complete"
    };
    
    static void print_binder_stats(struct seq_file *m, const char *prefix,
    			       struct binder_stats *stats)
    {
    	int i;
    
    	BUILD_BUG_ON(ARRAY_SIZE(stats->bc) !=
    		     ARRAY_SIZE(binder_command_strings));
    	for (i = 0; i < ARRAY_SIZE(stats->bc); i++) {
    		if (stats->bc[i])
    			seq_printf(m, "%s%s: %d\n", prefix,
    				   binder_command_strings[i], stats->bc[i]);
    	}
    
    	BUILD_BUG_ON(ARRAY_SIZE(stats->br) !=
    		     ARRAY_SIZE(binder_return_strings));
    	for (i = 0; i < ARRAY_SIZE(stats->br); i++) {
    		if (stats->br[i])
    			seq_printf(m, "%s%s: %d\n", prefix,
    				   binder_return_strings[i], stats->br[i]);
    	}
    
    	BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) !=
    		     ARRAY_SIZE(binder_objstat_strings));
    	BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) !=
    		     ARRAY_SIZE(stats->obj_deleted));
    	for (i = 0; i < ARRAY_SIZE(stats->obj_created); i++) {
    		if (stats->obj_created[i] || stats->obj_deleted[i])
    			seq_printf(m, "%s%s: active %d total %d\n", prefix,
    				binder_objstat_strings[i],
    				stats->obj_created[i] - stats->obj_deleted[i],
    				stats->obj_created[i]);
    	}
    }
    
    static void print_binder_proc_stats(struct seq_file *m,
    				    struct binder_proc *proc)
    {
    	struct binder_work *w;
    	struct rb_node *n;
    	int count, strong, weak;
    
    	seq_printf(m, "proc %d\n", proc->pid);
    	seq_printf(m, "context %s\n", proc->context->name);
    	count = 0;
    	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n))
    		count++;
    	seq_printf(m, "  threads: %d\n", count);
    	seq_printf(m, "  requested threads: %d+%d/%d\n"
    			"  ready threads %d\n"
    			"  free async space %zd\n", proc->requested_threads,
    			proc->requested_threads_started, proc->max_threads,
    			proc->ready_threads, proc->free_async_space);
    	count = 0;
    	for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n))
    		count++;
    	seq_printf(m, "  nodes: %d\n", count);
    	count = 0;
    	strong = 0;
    	weak = 0;
    	for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) {
    		struct binder_ref *ref = rb_entry(n, struct binder_ref,
    						  rb_node_desc);
    		count++;
    		strong += ref->strong;
    		weak += ref->weak;
    	}
    	seq_printf(m, "  refs: %d s %d w %d\n", count, strong, weak);
    
    	count = 0;
    	for (n = rb_first(&proc->allocated_buffers); n != NULL; n = rb_next(n))
    		count++;
    	seq_printf(m, "  buffers: %d\n", count);
    
    	count = 0;
    	list_for_each_entry(w, &proc->todo, entry) {
    		switch (w->type) {
    		case BINDER_WORK_TRANSACTION:
    			count++;
    			break;
    		default:
    			break;
    		}
    	}
    	seq_printf(m, "  pending transactions: %d\n", count);
    
    	print_binder_stats(m, "  ", &proc->stats);
    }
    
    
    static int binder_state_show(struct seq_file *m, void *unused)
    {
    	struct binder_proc *proc;
    	struct binder_node *node;
    	int do_lock = !binder_debug_no_lock;
    
    	if (do_lock)
    		binder_lock(__func__);
    
    	seq_puts(m, "binder state:\n");
    
    	if (!hlist_empty(&binder_dead_nodes))
    		seq_puts(m, "dead nodes:\n");
    	hlist_for_each_entry(node, &binder_dead_nodes, dead_node)
    		print_binder_node(m, node);
    
    	hlist_for_each_entry(proc, &binder_procs, proc_node)
    		print_binder_proc(m, proc, 1);
    	if (do_lock)
    		binder_unlock(__func__);
    	return 0;
    }
    
    static int binder_stats_show(struct seq_file *m, void *unused)
    {
    	struct binder_proc *proc;
    	int do_lock = !binder_debug_no_lock;
    
    	if (do_lock)
    		binder_lock(__func__);
    
    	seq_puts(m, "binder stats:\n");
    
    	print_binder_stats(m, "", &binder_stats);
    
    	hlist_for_each_entry(proc, &binder_procs, proc_node)
    		print_binder_proc_stats(m, proc);
    	if (do_lock)
    		binder_unlock(__func__);
    	return 0;
    }
    
    static int binder_transactions_show(struct seq_file *m, void *unused)
    {
    	struct binder_proc *proc;
    	int do_lock = !binder_debug_no_lock;
    
    	if (do_lock)
    		binder_lock(__func__);
    
    	seq_puts(m, "binder transactions:\n");
    	hlist_for_each_entry(proc, &binder_procs, proc_node)
    		print_binder_proc(m, proc, 0);
    	if (do_lock)
    		binder_unlock(__func__);
    	return 0;
    }
    
    static int binder_proc_show(struct seq_file *m, void *unused)
    {
    	struct binder_proc *itr;
    	int pid = (unsigned long)m->private;
    	int do_lock = !binder_debug_no_lock;
    
    	if (do_lock)
    		binder_lock(__func__);
    
    	hlist_for_each_entry(itr, &binder_procs, proc_node) {
    		if (itr->pid == pid) {
    			seq_puts(m, "binder proc state:\n");
    			print_binder_proc(m, itr, 1);
    		}
    	}
    	if (do_lock)
    		binder_unlock(__func__);
    	return 0;
    }
    
    static void print_binder_transaction_log_entry(struct seq_file *m,
    					struct binder_transaction_log_entry *e)
    {
    	seq_printf(m,
    		   "%d: %s from %d:%d to %d:%d context %s node %d handle %d size %d:%d\n",
    		   e->debug_id, (e->call_type == 2) ? "reply" :
    		   ((e->call_type == 1) ? "async" : "call "), e->from_proc,
    		   e->from_thread, e->to_proc, e->to_thread, e->context_name,
    		   e->to_node, e->target_handle, e->data_size, e->offsets_size);
    }
    
    static int binder_transaction_log_show(struct seq_file *m, void *unused)
    {
    	struct binder_transaction_log *log = m->private;
    	int i;
    
    	if (log->full) {
    		for (i = log->next; i < ARRAY_SIZE(log->entry); i++)
    			print_binder_transaction_log_entry(m, &log->entry[i]);
    	}
    	for (i = 0; i < log->next; i++)
    		print_binder_transaction_log_entry(m, &log->entry[i]);
    	return 0;
    }
    
    static const struct file_operations binder_fops = {
    	.owner = THIS_MODULE,
    	.poll = binder_poll,
    	.unlocked_ioctl = binder_ioctl,
    	.compat_ioctl = binder_ioctl,
    	.mmap = binder_mmap,
    	.open = binder_open,
    	.flush = binder_flush,
    	.release = binder_release,
    };
    
    BINDER_DEBUG_ENTRY(state);
    BINDER_DEBUG_ENTRY(stats);
    BINDER_DEBUG_ENTRY(transactions);
    BINDER_DEBUG_ENTRY(transaction_log);
    
    static int __init init_binder_device(const char *name)
    {
    	int ret;
    	struct binder_device *binder_device;
    
    	binder_device = kzalloc(sizeof(*binder_device), GFP_KERNEL);
    	if (!binder_device)
    		return -ENOMEM;
    
    	binder_device->miscdev.fops = &binder_fops;
    	binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
    	binder_device->miscdev.name = name;
    
    	binder_device->context.binder_context_mgr_uid = INVALID_UID;
    	binder_device->context.name = name;
    
    	ret = misc_register(&binder_device->miscdev);
    	if (ret < 0) {
    		kfree(binder_device);
    		return ret;
    	}
    
    	hlist_add_head(&binder_device->hlist, &binder_devices);
    
    	return ret;
    }
    
    static int __init binder_init(void)
    {
    	int ret;
    	char *device_name, *device_names;
    	struct binder_device *device;
    	struct hlist_node *tmp;
    
    	binder_debugfs_dir_entry_root = debugfs_create_dir("binder", NULL);
    	if (binder_debugfs_dir_entry_root)
    		binder_debugfs_dir_entry_proc = debugfs_create_dir("proc",
    						 binder_debugfs_dir_entry_root);
    
    	if (binder_debugfs_dir_entry_root) {
    		debugfs_create_file("state",
    				    S_IRUGO,
    				    binder_debugfs_dir_entry_root,
    				    NULL,
    				    &binder_state_fops);
    		debugfs_create_file("stats",
    				    S_IRUGO,
    				    binder_debugfs_dir_entry_root,
    				    NULL,
    				    &binder_stats_fops);
    		debugfs_create_file("transactions",
    				    S_IRUGO,
    				    binder_debugfs_dir_entry_root,
    				    NULL,
    				    &binder_transactions_fops);
    		debugfs_create_file("transaction_log",
    				    S_IRUGO,
    				    binder_debugfs_dir_entry_root,
    				    &binder_transaction_log,
    				    &binder_transaction_log_fops);
    		debugfs_create_file("failed_transaction_log",
    				    S_IRUGO,
    				    binder_debugfs_dir_entry_root,
    				    &binder_transaction_log_failed,
    				    &binder_transaction_log_fops);
    	}
    
    	/*
    	 * Copy the module_parameter string, because we don't want to
    	 * tokenize it in-place.
    	 */
    	device_names = kzalloc(strlen(binder_devices_param) + 1, GFP_KERNEL);
    	if (!device_names) {
    		ret = -ENOMEM;
    		goto err_alloc_device_names_failed;
    	}
    	strcpy(device_names, binder_devices_param);
    
    	while ((device_name = strsep(&device_names, ","))) {
    		ret = init_binder_device(device_name);
    		if (ret)
    			goto err_init_binder_device_failed;
    	}
    
    	return ret;
    
    err_init_binder_device_failed:
    	hlist_for_each_entry_safe(device, tmp, &binder_devices, hlist) {
    		misc_deregister(&device->miscdev);
    		hlist_del(&device->hlist);
    		kfree(device);
    	}
    err_alloc_device_names_failed:
    	debugfs_remove_recursive(binder_debugfs_dir_entry_root);
    
    	return ret;
    }
    
    device_initcall(binder_init);
    
    #define CREATE_TRACE_POINTS
    #include "binder_trace.h"
    
    MODULE_LICENSE("GPL v2");