staging: binder: Support concurrent 32 bit and 64 bit processes.

For 64bit systems we want to use the same binder interface for 32bit and
64bit processes. Thus the size and the layout of the structures passed
between the kernel and the userspace has to be the same for both 32 and
64bit processes.

This change replaces all the uses of void* and size_t with
binder_uintptr_t and binder_size_t. These are then typedefed to specific
sizes depending on the use of the interface, as follows:
       * __u32 - on legacy 32bit only userspace
       * __u64 - on mixed 32/64bit userspace where all processes use the same
interface.

This change also increments the BINDER_CURRENT_PROTOCOL_VERSION to 8 and
hooks the compat_ioctl entry for the mixed 32/64bit Android userspace.

This patch also provides a CONFIG_ANDROID_BINDER_IPC_32BIT option for
compatability, which if set which enables the old protocol, setting
BINDER_CURRENT_PROTOCOL_VERSION to 7, on 32 bit systems.

Please note that all 64bit kernels will use the 64bit Binder ABI.

Cc: Colin Cross <ccross@android.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Serban Constantinescu <serban.constantinescu@arm.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Arve Hjønnevåg <arve@android.com>
[jstultz: Merged with upstream type changes. Various whitespace fixes
and longer Kconfig description for checkpatch. Included improved commit
message from Serban (with a few tweaks).]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/Kconfig

@@ -20,6 +20,18 @@ config ANDROID_BINDER_IPC
 	  Android process, using Binder to identify, invoke and pass arguments
 	  between said processes.
 
+config ANDROID_BINDER_IPC_32BIT
+	bool "Use old 32-bit binder api"
+	depends on !64BIT
+	---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 ASHMEM
 	bool "Enable the Anonymous Shared Memory Subsystem"
 	default n

drivers/staging/android/binder.h

@@ -20,6 +20,10 @@
 #ifndef _LINUX_BINDER_H
 #define _LINUX_BINDER_H
 
+#ifdef CONFIG_ANDROID_BINDER_IPC_32BIT
+#define BINDER_IPC_32BIT 1
+#endif
+
 #include "uapi/binder.h"
 
 #endif /* _LINUX_BINDER_H */

drivers/staging/android/binder_trace.h

@@ -152,7 +152,7 @@ TRACE_EVENT(binder_transaction_node_to_ref,
 	TP_STRUCT__entry(
 		__field(int, debug_id)
 		__field(int, node_debug_id)
-		__field(void __user *, node_ptr)
+		__field(binder_uintptr_t, node_ptr)
 		__field(int, ref_debug_id)
 		__field(uint32_t, ref_desc)
 	),
@@ -163,8 +163,9 @@ TRACE_EVENT(binder_transaction_node_to_ref,
 		__entry->ref_debug_id = ref->debug_id;
 		__entry->ref_desc = ref->desc;
 	),
-	TP_printk("transaction=%d node=%d src_ptr=0x%p ==> dest_ref=%d dest_desc=%d",
-		  __entry->debug_id, __entry->node_debug_id, __entry->node_ptr,
+	TP_printk("transaction=%d node=%d src_ptr=0x%016llx ==> dest_ref=%d dest_desc=%d",
+		  __entry->debug_id, __entry->node_debug_id,
+		  (u64)__entry->node_ptr,
 		  __entry->ref_debug_id, __entry->ref_desc)
 );
 
@@ -177,7 +178,7 @@ TRACE_EVENT(binder_transaction_ref_to_node,
 		__field(int, ref_debug_id)
 		__field(uint32_t, ref_desc)
 		__field(int, node_debug_id)
-		__field(void __user *, node_ptr)
+		__field(binder_uintptr_t, node_ptr)
 	),
 	TP_fast_assign(
 		__entry->debug_id = t->debug_id;
@@ -186,9 +187,10 @@ TRACE_EVENT(binder_transaction_ref_to_node,
 		__entry->node_debug_id = ref->node->debug_id;
 		__entry->node_ptr = ref->node->ptr;
 	),
-	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ptr=0x%p",
+	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ptr=0x%016llx",
 		  __entry->debug_id, __entry->node_debug_id,
-		  __entry->ref_debug_id, __entry->ref_desc, __entry->node_ptr)
+		  __entry->ref_debug_id, __entry->ref_desc,
+		  (u64)__entry->node_ptr)
 );
 
 TRACE_EVENT(binder_transaction_ref_to_ref,

drivers/staging/android/uapi/binder.h

@@ -39,6 +39,14 @@ enum {
 	FLAT_BINDER_FLAG_ACCEPTS_FDS = 0x100,
 };
 
+#ifdef BINDER_IPC_32BIT
+typedef __u32 binder_size_t;
+typedef __u32 binder_uintptr_t;
+#else
+typedef __u64 binder_size_t;
+typedef __u64 binder_uintptr_t;
+#endif
+
 /*
  * This is the flattened representation of a Binder object for transfer
  * between processes.  The 'offsets' supplied as part of a binder transaction
@@ -53,12 +61,12 @@ struct flat_binder_object {
 
 	/* 8 bytes of data. */
 	union {
-		void __user	*binder;	/* local object */
+		binder_uintptr_t	binder;	/* local object */
 		__u32			handle;	/* remote object */
 	};
 
 	/* extra data associated with local object */
-	void __user		*cookie;
+	binder_uintptr_t	cookie;
 };
 
 /*
@@ -67,12 +75,12 @@ struct flat_binder_object {
  */
 
 struct binder_write_read {
-	size_t write_size;	/* bytes to write */
-	size_t write_consumed;	/* bytes consumed by driver */
-	unsigned long	write_buffer;
-	size_t read_size;	/* bytes to read */
-	size_t read_consumed;	/* bytes consumed by driver */
-	unsigned long	read_buffer;
+	binder_size_t		write_size;	/* bytes to write */
+	binder_size_t		write_consumed;	/* bytes consumed by driver */
+	binder_uintptr_t	write_buffer;
+	binder_size_t		read_size;	/* bytes to read */
+	binder_size_t		read_consumed;	/* bytes consumed by driver */
+	binder_uintptr_t	read_buffer;
 };
 
 /* Use with BINDER_VERSION, driver fills in fields. */
@@ -82,7 +90,11 @@ struct binder_version {
 };
 
 /* This is the current protocol version. */
+#ifdef BINDER_IPC_32BIT
 #define BINDER_CURRENT_PROTOCOL_VERSION 7
+#else
+#define BINDER_CURRENT_PROTOCOL_VERSION 8
+#endif
 
 #define BINDER_WRITE_READ		_IOWR('b', 1, struct binder_write_read)
 #define BINDER_SET_IDLE_TIMEOUT		_IOW('b', 3, __s64)
@@ -119,18 +131,20 @@ struct binder_transaction_data {
 	 * identifying the target and contents of the transaction.
 	 */
 	union {
-		__u32	handle;	/* target descriptor of command transaction */
-		void	*ptr;	/* target descriptor of return transaction */
+		/* target descriptor of command transaction */
+		__u32	handle;
+		/* target descriptor of return transaction */
+		binder_uintptr_t ptr;
 	} target;
-	void		*cookie;	/* target object cookie */
+	binder_uintptr_t	cookie;	/* target object cookie */
 	__u32		code;		/* transaction command */
 
 	/* General information about the transaction. */
 	__u32	        flags;
 	pid_t		sender_pid;
 	uid_t		sender_euid;
-	size_t		data_size;	/* number of bytes of data */
-	size_t		offsets_size;	/* number of bytes of offsets */
+	binder_size_t	data_size;	/* number of bytes of data */
+	binder_size_t	offsets_size;	/* number of bytes of offsets */
 
 	/* If this transaction is inline, the data immediately
 	 * follows here; otherwise, it ends with a pointer to
@@ -139,22 +153,22 @@ struct binder_transaction_data {
 	union {
 		struct {
 			/* transaction data */
-			const void __user	*buffer;
+			binder_uintptr_t	buffer;
 			/* offsets from buffer to flat_binder_object structs */
-			const void __user	*offsets;
+			binder_uintptr_t	offsets;
 		} ptr;
 		__u8	buf[8];
 	} data;
 };
 
 struct binder_ptr_cookie {
-	void *ptr;
-	void *cookie;
+	binder_uintptr_t ptr;
+	binder_uintptr_t cookie;
 };
 
 struct binder_handle_cookie {
 	__u32 handle;
-	void *cookie;
+	binder_uintptr_t cookie;
 } __attribute__((packed));
 
 struct binder_pri_desc {
@@ -164,8 +178,8 @@ struct binder_pri_desc {
 
 struct binder_pri_ptr_cookie {
 	__s32 priority;
-	void *ptr;
-	void *cookie;
+	binder_uintptr_t ptr;
+	binder_uintptr_t cookie;
 };
 
 enum binder_driver_return_protocol {
@@ -240,11 +254,11 @@ enum binder_driver_return_protocol {
 	 * stop threadpool thread
 	 */
 
-	BR_DEAD_BINDER = _IOR('r', 15, void *),
+	BR_DEAD_BINDER = _IOR('r', 15, binder_uintptr_t),
 	/*
 	 * void *: cookie
 	 */
-	BR_CLEAR_DEATH_NOTIFICATION_DONE = _IOR('r', 16, void *),
+	BR_CLEAR_DEATH_NOTIFICATION_DONE = _IOR('r', 16, binder_uintptr_t),
 	/*
 	 * void *: cookie
 	 */
@@ -270,7 +284,7 @@ enum binder_driver_command_protocol {
 	 * Else you have acquired a primary reference on the object.
 	 */
 
-	BC_FREE_BUFFER = _IOW('c', 3, void *),
+	BC_FREE_BUFFER = _IOW('c', 3, binder_uintptr_t),
 	/*
 	 * void *: ptr to transaction data received on a read
 	 */
@@ -327,7 +341,7 @@ enum binder_driver_command_protocol {
 	 * void *: cookie
 	 */
 
-	BC_DEAD_BINDER_DONE = _IOW('c', 16, void *),
+	BC_DEAD_BINDER_DONE = _IOW('c', 16, binder_uintptr_t),
 	/*
 	 * void *: cookie
 	 */