X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/89b3af67bb32e691275bf6fa803d1834b2284115..99c3a10404e5d1ef94397ab4df5a8b74711fc4d3:/osfmk/i386/asm64.h

diff --git a/osfmk/i386/asm64.h b/osfmk/i386/asm64.h
index bb1a51c0b..0f9213e7d 100644
--- a/osfmk/i386/asm64.h
+++ b/osfmk/i386/asm64.h
@@ -28,6 +28,7 @@
 
 /* Helper macros for 64-bit mode switching */
 
+#if __i386__
 /*
  * Long jump to 64-bit space from 32-bit compatibility mode.
  */
@@ -54,9 +55,38 @@
  * Long jump to 32-bit compatibility mode from 64-bit space.
  */
 #define ENTER_COMPAT_MODE()			\
-	ljmp	*4f				;\
-4:	.long	5f				;\
-	.word	KERNEL_CS			;\
+	ljmp	*(%rip)				;\
+	.long	4f				;\
+	.word	KERNEL32_CS			;\
 	.code32					;\
-5:
+4:
 
+#else
+
+/*
+ * Long jump to 64-bit space from 32-bit compatibility mode.
+ * Effected, in fact, by a long return ..
+ *  - we push the 64-bit kernel code selector KERNEL64_CS
+ *  - call .+1 to get EIP on stack
+ *  - adjust return address after lret
+ *  - lret to return to next instruction but 64-bit mode.
+ */
+#define	ENTER_64BIT_MODE()			\
+	push	$KERNEL64_CS			;\
+	call    1f				;\
+1:	addl    $(2f-1b), (%esp)		;\
+	lret					;\
+2:	.code64
+
+/*
+ * Long jump to 32-bit compatibility mode from 64-bit space.
+ * Effected by long return similar to ENTER_64BIT_MODE.
+ */
+#define ENTER_COMPAT_MODE()			\
+	call	3f				;\
+3:	addq	$(4f-3b), (%rsp)		;\
+	movl	$KERNEL32_CS, 4(%rsp)		;\
+	lret					;\
+4:	.code32
+
+#endif