Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

===================================================================
RCS file: /ftp/cvs/cvsroot/src/sys/arch/amd64/amd64/cpufunc.S,v
rcsdiff: /ftp/cvs/cvsroot/src/sys/arch/amd64/amd64/cpufunc.S,v: warning: Unknown phrases like `commitid ...;' are present.
retrieving revision 1.27.8.1
retrieving revision 1.28
diff -u -p -r1.27.8.1 -r1.28
--- src/sys/arch/amd64/amd64/cpufunc.S	2018/02/26 00:49:48	1.27.8.1
+++ src/sys/arch/amd64/amd64/cpufunc.S	2017/10/15 10:58:32	1.28
@@ -1,4 +1,4 @@
-/*	$NetBSD: cpufunc.S,v 1.27.8.1 2018/02/26 00:49:48 snj Exp $	*/
+/*	$NetBSD: cpufunc.S,v 1.28 2017/10/15 10:58:32 maxv Exp $	*/
 
 /*-
  * Copyright (c) 1998, 2007, 2008 The NetBSD Foundation, Inc.
@@ -371,7 +371,8 @@ ENTRY(__byte_swap_u16_variable)
  * Load a new GDT pointer (and do any necessary cleanup).
  * XXX It's somewhat questionable whether reloading all the segment registers
  * is necessary, since the actual descriptor data is not changed except by
- * process creation and exit, both of which clean up via task switches.
+ * process creation and exit, both of which clean up via task switches.  OTOH,
+ * this only happens at run time when the GDT is resized.
  */
 #ifndef XEN
 ENTRY(lgdt)
@@ -381,21 +382,19 @@ ENTRY(lgdt)
 	/* Flush the prefetch q. */
 	jmp	1f
 	nop
-1:	jmp	_C_LABEL(lgdt_finish)
-END(lgdt)
-#endif
-
+1:	/* Reload "stale" selectors. */
+#else /* XEN */
 /*
  * void lgdt_finish(void);
  * Reload segments after a GDT change
  */
 ENTRY(lgdt_finish)
+#endif /* XEN */
 	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax
 	movl	%eax,%ds
 	movl	%eax,%es
 	movl	%eax,%ss
-	jmp	_C_LABEL(x86_flush)
-END(lgdt_finish)
+	/* FALLTHROUGH */
 
 /*
  * void x86_flush()
@@ -642,6 +641,7 @@ ENTRY(setfs)
 	movw	%di, %fs
 	ret
 
+#ifndef XEN
 ENTRY(setusergs)
 	CLI(ax)
 	swapgs
@@ -649,3 +649,4 @@ ENTRY(setusergs)
 	swapgs
 	STI(ax)
 	ret
+#endif