[PATCH] Allow sysenter/sysexit in x86-64 assembly, disassemble swapgs properly

[Jakub Jelinek]

Hi!

This patch fixes 2 things:
1) sysenter/sysexit were not allowed in x86-64 -64 assembly, while
   they are present on IA32e and e.g. Linux kernel needs to work around
   this by using .byte   0xf, 0x35 instead of sysexit.
2) swapgs instruction has been disassembled improperly as invlpg %ax.

Ok to commit?

2004-03-12  Jakub Jelinek  <jakub@redhat.com>

	* i386-dis.c (grps): Use INVLPG_Fixup instead of OP_E for invlpg.
	(INVLPG_Fixup): New function.
	(PNI_Fixup): Remove ATTRIBUTE_UNUSED from sizeflag.

	* opcode/i386.h (i386_optab): Remove CpuNo64 from sysenter and
	sysexit.

--- opcodes/i386-dis.c.jj	2004-03-12 09:08:10.000000000 +0100
+++ opcodes/i386-dis.c	2004-03-12 09:53:51.980982397 +0100
@@ -1,6 +1,6 @@
 /* Print i386 instructions for GDB, the GNU debugger.
    Copyright 1988, 1989, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2001, 2002, 2003 Free Software Foundation, Inc.
+   2001, 2002, 2003, 2004 Free Software Foundation, Inc.
 
 This file is part of GDB.
 
@@ -94,6 +94,7 @@ static void OP_3DNowSuffix (int, int);
 static void OP_SIMD_Suffix (int, int);
 static void SIMD_Fixup (int, int);
 static void PNI_Fixup (int, int);
+static void INVLPG_Fixup (int, int);
 static void BadOp (void);
 
 struct dis_private {
@@ -1360,7 +1361,7 @@ static const struct dis386 grps[][8] = {
     { "smswQ",	Ev, XX, XX },
     { "(bad)",	XX, XX, XX },
     { "lmsw",	Ew, XX, XX },
-    { "invlpg",	Ew, XX, XX },
+    { "invlpg",	INVLPG_Fixup, w_mode, XX, XX },
   },
   /* GRP8 */
   {
@@ -4106,7 +4107,7 @@ SIMD_Fixup (int extrachar, int sizeflag 
 }
 
 static void
-PNI_Fixup (int extrachar ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED)
+PNI_Fixup (int extrachar ATTRIBUTE_UNUSED, int sizeflag)
 {
   if (mod == 3 && reg == 1)
     {
@@ -4131,6 +4132,21 @@ PNI_Fixup (int extrachar ATTRIBUTE_UNUSE
 }
 
 static void
+INVLPG_Fixup (int bytemode, int sizeflag)
+{
+  if (*codep == 0xf8)
+    {
+      char *p = obuf + strlen (obuf);
+
+      /* Override "invlpg".  */
+      strcpy (p - 6, "swapgs");
+      codep++;
+    }
+  else
+    OP_E (bytemode, sizeflag);
+}
+
+static void
 BadOp (void)
 {
   /* Throw away prefixes and 1st. opcode byte.  */
--- include/opcode/i386.h.jj	2003-07-02 17:01:57.000000000 +0200
+++ include/opcode/i386.h	2004-03-12 09:25:03.015089553 +0100
@@ -1,6 +1,6 @@
 /* opcode/i386.h -- Intel 80386 opcode table
    Copyright 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001
+   2000, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
 This file is part of GAS, the GNU Assembler, and GDB, the GNU Debugger.
@@ -896,8 +896,8 @@ static const template i386_optab[] = {
 {"cmpxchg8b",1,0x0fc7, 1, Cpu586, NoSuf|Modrm,		{ LLongMem, 0, 0} },
 
 /* Pentium II/Pentium Pro extensions.  */
-{"sysenter",0, 0x0f34, X, Cpu686|CpuNo64, NoSuf,	{ 0, 0, 0} },
-{"sysexit", 0, 0x0f35, X, Cpu686|CpuNo64, NoSuf,	{ 0, 0, 0} },
+{"sysenter",0, 0x0f34, X, Cpu686, NoSuf,		{ 0, 0, 0} },
+{"sysexit", 0, 0x0f35, X, Cpu686, NoSuf,		{ 0, 0, 0} },
 {"fxsave",  1, 0x0fae, 0, Cpu686, FP|Modrm,		{ LLongMem, 0, 0} },
 {"fxrstor", 1, 0x0fae, 1, Cpu686, FP|Modrm,		{ LLongMem, 0, 0} },
 {"rdpmc",   0, 0x0f33, X, Cpu686, NoSuf,		{ 0, 0, 0} },

	Jakub