[PATCH 28/37] binder: add spinlocks to protect todo lists

[Todd Kjos <tkjos@android.com>]

The todo lists in the proc, thread, and node structures
are accessed by other procs/threads to place work
items on the queue.

The todo lists are protected by the new proc->inner_lock.
No locks should ever be nested under these locks. As the
name suggests, an outer lock will be introduced in
a later patch.

Signed-off-by: Todd Kjos <tkjos@google.com>
---
 drivers/android/binder.c | 355 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 269 insertions(+), 86 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 6c741416fa00..5a0389767843 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -279,8 +279,16 @@ struct binder_device {
 	struct binder_context context;
 };
 
+/**
+ * struct binder_work - work enqueued on a worklist
+ * @entry:             node enqueued on list
+ * @type:              type of work to be performed
+ *
+ * There are separate work lists for proc, thread, and node (async).
+ */
 struct binder_work {
 	struct list_head entry;
+
 	enum {
 		BINDER_WORK_TRANSACTION = 1,
 		BINDER_WORK_TRANSACTION_COMPLETE,
@@ -303,6 +311,7 @@ struct binder_error {
  *                        (invariant after initialized)
  * @lock:                 lock for node fields
  * @work:                 worklist element for node work
+ *                        (protected by @proc->inner_lock)
  * @rb_node:              element for proc->nodes tree
  * @dead_node:            element for binder_dead_nodes list
  *                        (protected by binder_dead_nodes_lock)
@@ -347,6 +356,7 @@ struct binder_error {
  * @min_priority:         minimum scheduling priority
  *                        (invariant after initialized)
  * @async_todo:           list of async work items
+ *                        (protected by @proc->inner_lock)
  *
  * Bookkeeping structure for binder nodes.
  */
@@ -388,6 +398,11 @@ struct binder_node {
 };
 
 struct binder_ref_death {
+	/**
+	 * @work: worklist element for death notifications
+	 *        (protected by inner_lock of the proc that
+	 *        this ref belongs to)
+	 */
 	struct binder_work work;
 	binder_uintptr_t cookie;
 };
@@ -467,11 +482,13 @@ enum binder_deferred_state {
  * @is_dead:              process is dead and awaiting free
  *                        when outstanding transactions are cleaned up
  * @todo:                 list of work for this process
+ *                        (protected by @inner_lock)
  * @wait:                 wait queue head to wait for proc work
  *                        (invariant after initialized)
  * @stats:                per-process binder statistics
  *                        (atomics, no lock needed)
  * @delivered_death:      list of delivered death notification
+ *                        (protected by @inner_lock)
  * @max_threads:          cap on number of binder threads
  * @requested_threads:    number of binder threads requested but not
  *                        yet started. In current implementation, can
@@ -542,6 +559,7 @@ enum {
  *                        (no lock needed)
  * @transaction_stack:    stack of in-progress transactions for this thread
  * @todo:                 list of work to do for this thread
+ *                        (protected by @proc->inner_lock)
  * @return_error:         transaction errors reported by this thread
  *                        (only accessed by this thread)
  * @reply_error:          transaction errors reported by target thread
@@ -689,6 +707,111 @@ _binder_node_unlock(struct binder_node *node, int line)
 	spin_unlock(&node->lock);
 }
 
+static bool binder_worklist_empty_ilocked(struct list_head *list)
+{
+	return list_empty(list);
+}
+
+/**
+ * binder_worklist_empty() - Check if no items on the work list
+ * @proc:       binder_proc associated with list
+ * @list:	list to check
+ *
+ * Return: true if there are no items on list, else false
+ */
+static bool binder_worklist_empty(struct binder_proc *proc,
+				  struct list_head *list)
+{
+	bool ret;
+
+	binder_inner_proc_lock(proc);
+	ret = binder_worklist_empty_ilocked(list);
+	binder_inner_proc_unlock(proc);
+	return ret;
+}
+
+static void
+binder_enqueue_work_ilocked(struct binder_work *work,
+			   struct list_head *target_list)
+{
+	BUG_ON(target_list == NULL);
+	BUG_ON(work->entry.next && !list_empty(&work->entry));
+	list_add_tail(&work->entry, target_list);
+}
+
+/**
+ * binder_enqueue_work() - Add an item to the work list
+ * @proc:         binder_proc associated with list
+ * @work:         struct binder_work to add to list
+ * @target_list:  list to add work to
+ *
+ * Adds the work to the specified list. Asserts that work
+ * is not already on a list.
+ */
+static void
+binder_enqueue_work(struct binder_proc *proc,
+		    struct binder_work *work,
+		    struct list_head *target_list)
+{
+	binder_inner_proc_lock(proc);
+	binder_enqueue_work_ilocked(work, target_list);
+	binder_inner_proc_unlock(proc);
+}
+
+static void
+binder_dequeue_work_ilocked(struct binder_work *work)
+{
+	list_del_init(&work->entry);
+}
+
+/**
+ * binder_dequeue_work() - Removes an item from the work list
+ * @proc:         binder_proc associated with list
+ * @work:         struct binder_work to remove from list
+ *
+ * Removes the specified work item from whatever list it is on.
+ * Can safely be called if work is not on any list.
+ */
+static void
+binder_dequeue_work(struct binder_proc *proc, struct binder_work *work)
+{
+	binder_inner_proc_lock(proc);
+	binder_dequeue_work_ilocked(work);
+	binder_inner_proc_unlock(proc);
+}
+
+static struct binder_work *binder_dequeue_work_head_ilocked(
+					struct list_head *list)
+{
+	struct binder_work *w;
+
+	w = list_first_entry_or_null(list, struct binder_work, entry);
+	if (w)
+		list_del_init(&w->entry);
+	return w;
+}
+
+/**
+ * binder_dequeue_work_head() - Dequeues the item at head of list
+ * @proc:         binder_proc associated with list
+ * @list:         list to dequeue head
+ *
+ * Removes the head of the list if there are items on the list
+ *
+ * Return: pointer dequeued binder_work, NULL if list was empty
+ */
+static struct binder_work *binder_dequeue_work_head(
+					struct binder_proc *proc,
+					struct list_head *list)
+{
+	struct binder_work *w;
+
+	binder_inner_proc_lock(proc);
+	w = binder_dequeue_work_head_ilocked(list);
+	binder_inner_proc_unlock(proc);
+	return w;
+}
+
 static void
 binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
 static void binder_free_thread(struct binder_thread *thread);
@@ -870,8 +993,8 @@ static int binder_inc_node_ilocked(struct binder_node *node, int strong,
 		} 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);
+			binder_dequeue_work_ilocked(&node->work);
+			binder_enqueue_work_ilocked(&node->work, target_list);
 		}
 	} else {
 		if (!internal)
@@ -882,7 +1005,7 @@ static int binder_inc_node_ilocked(struct binder_node *node, int strong,
 					node->debug_id);
 				return -EINVAL;
 			}
-			list_add_tail(&node->work.entry, target_list);
+			binder_enqueue_work_ilocked(&node->work, target_list);
 		}
 	}
 	return 0;
@@ -926,19 +1049,20 @@ static bool binder_dec_node_ilocked(struct binder_node *node,
 
 	if (proc && (node->has_strong_ref || node->has_weak_ref)) {
 		if (list_empty(&node->work.entry)) {
-			list_add_tail(&node->work.entry, &node->proc->todo);
+			binder_enqueue_work_ilocked(&node->work, &proc->todo);
 			wake_up_interruptible(&node->proc->wait);
 		}
 	} else {
 		if (hlist_empty(&node->refs) && !node->local_strong_refs &&
 		    !node->local_weak_refs && !node->tmp_refs) {
-			list_del_init(&node->work.entry);
 			if (proc) {
-				rb_erase(&node->rb_node, &node->proc->nodes);
+				binder_dequeue_work_ilocked(&node->work);
+				rb_erase(&node->rb_node, &proc->nodes);
 				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
 					     "refless node %d deleted\n",
 					     node->debug_id);
 			} else {
+				BUG_ON(!list_empty(&node->work.entry));
 				spin_lock(&binder_dead_nodes_lock);
 				/*
 				 * tmp_refs could have changed so
@@ -1188,7 +1312,7 @@ static void binder_cleanup_ref(struct binder_ref *ref)
 			     "%d delete ref %d desc %d has death notification\n",
 			      ref->proc->pid, ref->data.debug_id,
 			      ref->data.desc);
-		list_del(&ref->death->work.entry);
+		binder_dequeue_work(ref->proc, &ref->death->work);
 		binder_stats_deleted(BINDER_STAT_DEATH);
 	}
 	binder_stats_deleted(BINDER_STAT_REF);
@@ -1539,8 +1663,9 @@ static void binder_send_failed_reply(struct binder_transaction *t,
 			binder_pop_transaction(target_thread, t);
 			if (target_thread->reply_error.cmd == BR_OK) {
 				target_thread->reply_error.cmd = error_code;
-				list_add_tail(
-					&target_thread->reply_error.work.entry,
+				binder_enqueue_work(
+					target_thread->proc,
+					&target_thread->reply_error.work,
 					&target_thread->todo);
 				wake_up_interruptible(&target_thread->wait);
 			} else {
@@ -2578,7 +2703,7 @@ static void binder_transaction(struct binder_proc *proc,
 		}
 	}
 	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
-	list_add_tail(&tcomplete->entry, &thread->todo);
+	binder_enqueue_work(proc, tcomplete, &thread->todo);
 
 	if (reply) {
 		if (target_thread->is_dead)
@@ -2609,7 +2734,7 @@ static void binder_transaction(struct binder_proc *proc,
 			goto err_dead_proc_or_thread;
 	}
 	t->work.type = BINDER_WORK_TRANSACTION;
-	list_add_tail(&t->work.entry, target_list);
+	binder_enqueue_work(target_proc, &t->work, target_list);
 	if (target_wait) {
 		if (reply || !(tr->flags & TF_ONE_WAY))
 			wake_up_interruptible_sync(target_wait);
@@ -2685,13 +2810,15 @@ static void binder_transaction(struct binder_proc *proc,
 	BUG_ON(thread->return_error.cmd != BR_OK);
 	if (in_reply_to) {
 		thread->return_error.cmd = BR_TRANSACTION_COMPLETE;
-		list_add_tail(&thread->return_error.work.entry,
-			      &thread->todo);
+		binder_enqueue_work(thread->proc,
+				    &thread->return_error.work,
+				    &thread->todo);
 		binder_send_failed_reply(in_reply_to, return_error);
 	} else {
 		thread->return_error.cmd = return_error;
-		list_add_tail(&thread->return_error.work.entry,
-			      &thread->todo);
+		binder_enqueue_work(thread->proc,
+				    &thread->return_error.work,
+				    &thread->todo);
 	}
 }
 
@@ -2884,11 +3011,21 @@ static int binder_thread_write(struct binder_proc *proc,
 				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;
+				struct binder_node *buf_node;
+				struct binder_work *w;
+
+				buf_node = buffer->target_node;
+				BUG_ON(!buf_node->has_async_transaction);
+				BUG_ON(buf_node->proc != proc);
+				binder_inner_proc_lock(proc);
+				w = binder_dequeue_work_head_ilocked(
+						&buf_node->async_todo);
+				if (!w)
+					buf_node->has_async_transaction = 0;
 				else
-					list_move_tail(buffer->target_node->async_todo.next, &thread->todo);
+					binder_enqueue_work_ilocked(
+							w, &thread->todo);
+				binder_inner_proc_unlock(proc);
 			}
 			trace_binder_transaction_buffer_release(buffer);
 			binder_transaction_buffer_release(proc, buffer, NULL);
@@ -3000,9 +3137,10 @@ static int binder_thread_write(struct binder_proc *proc,
 					WARN_ON(thread->return_error.cmd !=
 						BR_OK);
 					thread->return_error.cmd = BR_ERROR;
-					list_add_tail(
-					    &thread->return_error.work.entry,
-					    &thread->todo);
+					binder_enqueue_work(
+						thread->proc,
+						&thread->return_error.work,
+						&thread->todo);
 					binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
 						     "%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n",
 						     proc->pid, thread->pid);
@@ -3014,11 +3152,20 @@ static int binder_thread_write(struct binder_proc *proc,
 				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);
+					if (thread->looper &
+					    (BINDER_LOOPER_STATE_REGISTERED |
+					     BINDER_LOOPER_STATE_ENTERED))
+						binder_enqueue_work(
+							proc,
+							&ref->death->work,
+							&thread->todo);
+					else {
+						binder_enqueue_work(
+							proc,
+							&ref->death->work,
+							&proc->todo);
+						wake_up_interruptible(
+								&proc->wait);
 					}
 				}
 			} else {
@@ -3036,18 +3183,27 @@ static int binder_thread_write(struct binder_proc *proc,
 					break;
 				}
 				ref->death = NULL;
+				binder_inner_proc_lock(proc);
 				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);
+					if (thread->looper &
+					    (BINDER_LOOPER_STATE_REGISTERED |
+					     BINDER_LOOPER_STATE_ENTERED))
+						binder_enqueue_work_ilocked(
+								&death->work,
+								&thread->todo);
+					else {
+						binder_enqueue_work_ilocked(
+								&death->work,
+								&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;
 				}
+				binder_inner_proc_unlock(proc);
 			}
 		} break;
 		case BC_DEAD_BINDER_DONE: {
@@ -3059,8 +3215,13 @@ static int binder_thread_write(struct binder_proc *proc,
 				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);
+			binder_inner_proc_lock(proc);
+			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;
@@ -3074,19 +3235,25 @@ static int binder_thread_write(struct binder_proc *proc,
 			if (death == NULL) {
 				binder_user_error("%d:%d BC_DEAD_BINDER_DONE %016llx not found\n",
 					proc->pid, thread->pid, (u64)cookie);
+				binder_inner_proc_unlock(proc);
 				break;
 			}
-
-			list_del_init(&death->work.entry);
+			binder_dequeue_work_ilocked(&death->work);
 			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);
+				if (thread->looper &
+					(BINDER_LOOPER_STATE_REGISTERED |
+					 BINDER_LOOPER_STATE_ENTERED))
+					binder_enqueue_work_ilocked(
+						&death->work, &thread->todo);
+				else {
+					binder_enqueue_work_ilocked(
+							&death->work,
+							&proc->todo);
 					wake_up_interruptible(&proc->wait);
 				}
 			}
+			binder_inner_proc_unlock(proc);
 		} break;
 
 		default:
@@ -3113,12 +3280,14 @@ static void binder_stat_br(struct binder_proc *proc,
 static int binder_has_proc_work(struct binder_proc *proc,
 				struct binder_thread *thread)
 {
-	return !list_empty(&proc->todo) || thread->looper_need_return;
+	return !binder_worklist_empty(proc, &proc->todo) ||
+		thread->looper_need_return;
 }
 
 static int binder_has_thread_work(struct binder_thread *thread)
 {
-	return !list_empty(&thread->todo) || thread->looper_need_return;
+	return !binder_worklist_empty(thread->proc, &thread->todo) ||
+		thread->looper_need_return;
 }
 
 static int binder_put_node_cmd(struct binder_proc *proc,
@@ -3172,7 +3341,7 @@ static int binder_thread_read(struct binder_proc *proc,
 
 retry:
 	wait_for_proc_work = thread->transaction_stack == NULL &&
-				list_empty(&thread->todo);
+		binder_worklist_empty(proc, &thread->todo);
 
 	thread->looper |= BINDER_LOOPER_STATE_WAITING;
 	if (wait_for_proc_work)
@@ -3182,7 +3351,7 @@ static int binder_thread_read(struct binder_proc *proc,
 
 	trace_binder_wait_for_work(wait_for_proc_work,
 				   !!thread->transaction_stack,
-				   !list_empty(&thread->todo));
+				   !binder_worklist_empty(proc, &thread->todo));
 	if (wait_for_proc_work) {
 		if (!(thread->looper & (BINDER_LOOPER_STATE_REGISTERED |
 					BINDER_LOOPER_STATE_ENTERED))) {
@@ -3217,18 +3386,20 @@ static int binder_thread_read(struct binder_proc *proc,
 	while (1) {
 		uint32_t cmd;
 		struct binder_transaction_data tr;
-		struct binder_work *w;
+		struct binder_work *w = NULL;
+		struct list_head *list = NULL;
 		struct binder_transaction *t = NULL;
 		struct binder_thread *t_from;
 
 		binder_inner_proc_lock(proc);
-		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 {
+		if (!binder_worklist_empty_ilocked(&thread->todo))
+			list = &thread->todo;
+		else if (!binder_worklist_empty_ilocked(&proc->todo) &&
+			   wait_for_proc_work)
+			list = &proc->todo;
+		else {
+			binder_inner_proc_unlock(proc);
+
 			/* no data added */
 			if (ptr - buffer == 4 && !thread->looper_need_return)
 				goto retry;
@@ -3239,7 +3410,7 @@ static int binder_thread_read(struct binder_proc *proc,
 			binder_inner_proc_unlock(proc);
 			break;
 		}
-		list_del_init(&w->entry);
+		w = binder_dequeue_work_head_ilocked(list);
 
 		switch (w->type) {
 		case BINDER_WORK_TRANSACTION: {
@@ -3388,8 +3559,8 @@ static int binder_thread_read(struct binder_proc *proc,
 				binder_stats_deleted(BINDER_STAT_DEATH);
 			} else {
 				binder_inner_proc_lock(proc);
-				list_add_tail(&w->entry,
-					      &proc->delivered_death);
+				binder_enqueue_work_ilocked(
+						w, &proc->delivered_death);
 				binder_inner_proc_unlock(proc);
 			}
 			if (cmd == BR_DEAD_BINDER)
@@ -3499,13 +3670,16 @@ static int binder_thread_read(struct binder_proc *proc,
 	return 0;
 }
 
-static void binder_release_work(struct list_head *list)
+static void binder_release_work(struct binder_proc *proc,
+				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);
+	while (1) {
+		w = binder_dequeue_work_head(proc, list);
+		if (!w)
+			return;
+
 		switch (w->type) {
 		case BINDER_WORK_TRANSACTION: {
 			struct binder_transaction *t;
@@ -3669,7 +3843,7 @@ static int binder_thread_release(struct binder_proc *proc,
 
 	if (send_reply)
 		binder_send_failed_reply(send_reply, BR_DEAD_REPLY);
-	binder_release_work(&thread->todo);
+	binder_release_work(proc, &thread->todo);
 	binder_thread_dec_tmpref(thread);
 	return active_transactions;
 }
@@ -3686,7 +3860,7 @@ static unsigned int binder_poll(struct file *filp,
 	thread = binder_get_thread(proc);
 
 	wait_for_proc_work = thread->transaction_stack == NULL &&
-		list_empty(&thread->todo);
+		binder_worklist_empty(proc, &thread->todo);
 
 	binder_unlock(__func__);
 
@@ -3749,7 +3923,7 @@ static int binder_ioctl_write_read(struct file *filp,
 					 &bwr.read_consumed,
 					 filp->f_flags & O_NONBLOCK);
 		trace_binder_read_done(ret);
-		if (!list_empty(&proc->todo))
+		if (!binder_worklist_empty(proc, &proc->todo))
 			wake_up_interruptible(&proc->wait);
 		if (ret < 0) {
 			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
@@ -4069,10 +4243,10 @@ static int binder_node_release(struct binder_node *node, int refs)
 	int death = 0;
 	struct binder_proc *proc = node->proc;
 
-	binder_release_work(&node->async_todo);
+	binder_release_work(proc, &node->async_todo);
 
 	binder_inner_proc_lock(proc);
-	list_del_init(&node->work.entry);
+	binder_dequeue_work_ilocked(&node->work);
 	/*
 	 * The caller must have taken a temporary ref on the node,
 	 */
@@ -4101,13 +4275,15 @@ static int binder_node_release(struct binder_node *node, int refs)
 
 		death++;
 
+		binder_inner_proc_lock(ref->proc);
 		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);
+			binder_enqueue_work_ilocked(&ref->death->work,
+						    &ref->proc->todo);
 			wake_up_interruptible(&ref->proc->wait);
 		} else
 			BUG();
+		binder_inner_proc_unlock(ref->proc);
 	}
 
 	binder_debug(BINDER_DEBUG_DEAD_BINDER,
@@ -4183,8 +4359,8 @@ static void binder_deferred_release(struct binder_proc *proc)
 		binder_free_ref(ref);
 	}
 
-	binder_release_work(&proc->todo);
-	binder_release_work(&proc->delivered_death);
+	binder_release_work(proc, &proc->todo);
+	binder_release_work(proc, &proc->delivered_death);
 
 	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
 		     "%s: %d threads %d, nodes %d (ref %d), refs %d, active transactions %d\n",
@@ -4275,9 +4451,9 @@ static void print_binder_transaction(struct seq_file *m, const char *prefix,
 		   t->buffer->data);
 }
 
-static void print_binder_work(struct seq_file *m, const char *prefix,
-			      const char *transaction_prefix,
-			      struct binder_work *w)
+static void print_binder_work_ilocked(struct seq_file *m, const char *prefix,
+				      const char *transaction_prefix,
+				      struct binder_work *w)
 {
 	struct binder_node *node;
 	struct binder_transaction *t;
@@ -4318,15 +4494,16 @@ static void print_binder_work(struct seq_file *m, const char *prefix,
 	}
 }
 
-static void print_binder_thread(struct seq_file *m,
-				struct binder_thread *thread,
-				int print_always)
+static void print_binder_thread_ilocked(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;
 
+	WARN_ON(!spin_is_locked(&thread->proc->inner_lock));
 	seq_printf(m, "  thread %d: l %02x need_return %d tr %d\n",
 			thread->pid, thread->looper,
 			thread->looper_need_return,
@@ -4348,7 +4525,8 @@ static void print_binder_thread(struct seq_file *m,
 		}
 	}
 	list_for_each_entry(w, &thread->todo, entry) {
-		print_binder_work(m, "    ", "    pending transaction", w);
+		print_binder_work_ilocked(m, "    ",
+					  "    pending transaction", w);
 	}
 	if (!print_always && m->count == header_pos)
 		m->count = start_pos;
@@ -4375,9 +4553,13 @@ static void print_binder_node(struct seq_file *m, struct binder_node *node)
 			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);
+	if (node->proc) {
+		binder_inner_proc_lock(node->proc);
+		list_for_each_entry(w, &node->async_todo, entry)
+			print_binder_work_ilocked(m, "    ",
+					  "    pending async transaction", w);
+		binder_inner_proc_unlock(node->proc);
+	}
 }
 
 static void print_binder_ref(struct seq_file *m, struct binder_ref *ref)
@@ -4401,9 +4583,11 @@ static void print_binder_proc(struct seq_file *m,
 	seq_printf(m, "context %s\n", proc->context->name);
 	header_pos = m->count;
 
+	binder_inner_proc_lock(proc);
 	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n))
-		print_binder_thread(m, rb_entry(n, struct binder_thread,
+		print_binder_thread_ilocked(m, rb_entry(n, struct binder_thread,
 						rb_node), print_all);
+	binder_inner_proc_unlock(proc);
 	for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) {
 		struct binder_node *node = rb_entry(n, struct binder_node,
 						    rb_node);
@@ -4418,12 +4602,14 @@ static void print_binder_proc(struct seq_file *m,
 						     rb_node_desc));
 	}
 	binder_alloc_print_allocated(m, &proc->alloc);
+	binder_inner_proc_lock(proc);
 	list_for_each_entry(w, &proc->todo, entry)
-		print_binder_work(m, "  ", "  pending transaction", w);
+		print_binder_work_ilocked(m, "  ", "  pending transaction", w);
 	list_for_each_entry(w, &proc->delivered_death, entry) {
 		seq_puts(m, "  has delivered dead binder\n");
 		break;
 	}
+	binder_inner_proc_unlock(proc);
 	if (!print_all && m->count == header_pos)
 		m->count = start_pos;
 }
@@ -4562,15 +4748,12 @@ static void print_binder_proc_stats(struct seq_file *m,
 	seq_printf(m, "  buffers: %d\n", count);
 
 	count = 0;
+	binder_inner_proc_lock(proc);
 	list_for_each_entry(w, &proc->todo, entry) {
-		switch (w->type) {
-		case BINDER_WORK_TRANSACTION:
+		if (w->type == BINDER_WORK_TRANSACTION)
 			count++;
-			break;
-		default:
-			break;
-		}
 	}
+	binder_inner_proc_unlock(proc);
 	seq_printf(m, "  pending transactions: %d\n", count);
 
 	print_binder_stats(m, "  ", &proc->stats);
-- 
2.13.2.725.g09c95d1e9-goog