From 759d98484b5b51932d3d11651fa83c6bb268ce03 Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas@google.com>
Date: Mon, 6 Jun 2022 20:49:40 +0000
Subject: [PATCH] ANDROID: binder: switch task argument for binder_thread

Refactor binder priority functions to take in 'struct binder_thread *'
instead of just 'struct task_struct *'. This allows access to other
thread fields used in subsequent patches. In any case, the same task
reference is still available under thread->task.

There is no functional impact from this patch.

Bug: 148101660
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Change-Id: I67b599884580d957d776500e467827e5035c99f6
---
 drivers/android/binder.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 5fd3b653b6c1..cfb13996fe0d 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -648,10 +648,11 @@ static int to_kernel_prio(int policy, int user_priority)
 		return MAX_RT_PRIO - 1 - user_priority;
 }
 
-static void binder_do_set_priority(struct task_struct *task,
+static void binder_do_set_priority(struct binder_thread *thread,
 				   const struct binder_priority *desired,
 				   bool verify)
 {
+	struct task_struct *task = thread->task;
 	int priority; /* user-space prio value */
 	bool has_cap_nice;
 	unsigned int policy = desired->sched_policy;
@@ -711,22 +712,23 @@ static void binder_do_set_priority(struct task_struct *task,
 		set_user_nice(task, priority);
 }
 
-static void binder_set_priority(struct task_struct *task,
+static void binder_set_priority(struct binder_thread *thread,
 				const struct binder_priority *desired)
 {
-	binder_do_set_priority(task, desired, /* verify = */ true);
+	binder_do_set_priority(thread, desired, /* verify = */ true);
 }
 
-static void binder_restore_priority(struct task_struct *task,
+static void binder_restore_priority(struct binder_thread *thread,
 				    const struct binder_priority *desired)
 {
-	binder_do_set_priority(task, desired, /* verify = */ false);
+	binder_do_set_priority(thread, desired, /* verify = */ false);
 }
 
-static void binder_transaction_priority(struct task_struct *task,
+static void binder_transaction_priority(struct binder_thread *thread,
 					struct binder_transaction *t,
 					struct binder_node *node)
 {
+	struct task_struct *task = thread->task;
 	struct binder_priority desired = t->priority;
 	const struct binder_priority node_prio = {
 		.sched_policy = node->sched_policy,
@@ -758,7 +760,7 @@ static void binder_transaction_priority(struct task_struct *task,
 		desired = node_prio;
 	}
 
-	binder_set_priority(task, &desired);
+	binder_set_priority(thread, &desired);
 	trace_android_vh_binder_set_priority(t, task);
 }
 
@@ -2785,7 +2787,7 @@ static int binder_proc_transaction(struct binder_transaction *t,
 		thread = binder_select_thread_ilocked(proc);
 
 	if (thread) {
-		binder_transaction_priority(thread->task, t, node);
+		binder_transaction_priority(thread, t, node);
 		binder_enqueue_thread_work_ilocked(thread, &t->work);
 	} else if (!pending_async) {
 		binder_enqueue_work_ilocked(&t->work, &proc->todo);
@@ -3525,7 +3527,7 @@ static void binder_transaction(struct binder_proc *proc,
 		binder_inner_proc_unlock(target_proc);
 		wake_up_interruptible_sync(&target_thread->wait);
 		trace_android_vh_binder_restore_priority(in_reply_to, current);
-		binder_restore_priority(current, &in_reply_to->saved_priority);
+		binder_restore_priority(thread, &in_reply_to->saved_priority);
 		binder_free_transaction(in_reply_to);
 	} else if (!(t->flags & TF_ONE_WAY)) {
 		BUG_ON(t->buffer->async_transaction != 0);
@@ -3642,7 +3644,7 @@ err_invalid_target_handle:
 	BUG_ON(thread->return_error.cmd != BR_OK);
 	if (in_reply_to) {
 		trace_android_vh_binder_restore_priority(in_reply_to, current);
-		binder_restore_priority(current, &in_reply_to->saved_priority);
+		binder_restore_priority(thread, &in_reply_to->saved_priority);
 		thread->return_error.cmd = BR_TRANSACTION_COMPLETE;
 		binder_enqueue_thread_work(thread, &thread->return_error.work);
 		binder_send_failed_reply(in_reply_to, return_error);
@@ -4322,7 +4324,7 @@ retry:
 						 binder_stop_on_user_error < 2);
 		}
 		trace_android_vh_binder_restore_priority(NULL, current);
-		binder_restore_priority(current, &proc->default_priority);
+		binder_restore_priority(thread, &proc->default_priority);
 	}
 
 	if (non_block) {
@@ -4552,7 +4554,7 @@ retry:
 
 			trd->target.ptr = target_node->ptr;
 			trd->cookie =  target_node->cookie;
-			binder_transaction_priority(current, t, target_node);
+			binder_transaction_priority(thread, t, target_node);
 			cmd = BR_TRANSACTION;
 		} else {
 			trd->target.ptr = 0;