From 6b20cfbfee20b395eecad65b90100750021c6fbc Mon Sep 17 00:00:00 2001
From: Tao Huang <huangtao@rock-chips.com>
Date: Mon, 6 Aug 2018 17:03:29 +0800
Subject: [PATCH] Revert "UPSTREAM: ANDROID: binder: remove 32-bit binder
 interface."

This reverts commit 9ffd98e8155c716ae987491626544be016edd83c.
Which breaks 32bit Android <9
Make ANDROID_BINDER_IPC_32BIT depends on ANDROID_VERSION.

Change-Id: Ie599606ce998b27342471f31d1480d0a87135375
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
---
 drivers/android/Kconfig  | 13 +++++++++++++
 drivers/android/binder.c |  4 ++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
index 63ed9ceebf7b..7502ac3086c1 100644
--- a/drivers/android/Kconfig
+++ b/drivers/android/Kconfig
@@ -31,6 +31,19 @@ config ANDROID_BINDER_DEVICES
 	  created. Each binder device has its own context manager, and is
 	  therefore logically separated from the other devices.
 
+config ANDROID_BINDER_IPC_32BIT
+	bool
+	depends on !64BIT && ANDROID_BINDER_IPC
+	default y if ANDROID_VERSION < 0x09000000
+	---help---
+	  The Binder API has been changed to support both 32 and 64bit
+	  applications in a mixed environment.
+
+	  Enable this to support an old 32-bit Android user-space (v4.4 and
+	  earlier).
+
+	  Note that enabling this will break newer Android user-space.
+
 config ANDROID_BINDER_IPC_SELFTEST
 	bool "Android Binder IPC Driver Selftest"
 	depends on ANDROID_BINDER_IPC
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index b0c9d3548123..d1dfbe34fa7c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -71,6 +71,10 @@
 #include <linux/security.h>
 #include <linux/spinlock.h>
 
+#ifdef CONFIG_ANDROID_BINDER_IPC_32BIT
+#define BINDER_IPC_32BIT 1
+#endif
+
 #include <uapi/linux/android/binder.h>
 #include "binder_alloc.h"
 #include "binder_trace.h"