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Date:      Fri, 6 Jul 2012 14:25:59 +0000 (UTC)
From:      John Baldwin <jhb@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r238166 - head/sys/amd64/amd64
Message-ID:  <201207061425.q66EPxVe065409@svn.freebsd.org>

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Author: jhb
Date: Fri Jul  6 14:25:59 2012
New Revision: 238166
URL: http://svn.freebsd.org/changeset/base/238166

Log:
  Several fixes to the amd64 disassembler:
  - Add generic support for opcodes that are escape bytes used for
    multi-byte opcodes (such as the 0x0f prefix).  Use this to replace
    the hard-coded 0x0f special case and add support for three-byte
    opcodes that use the 0x0f38 prefix.
  - Decode all Intel VMX instructions.  invept and invvpid in particular are
    three-byte opcodes that use the 0x0f38 escape prefix.
  - Rework how the special 'SDEP' size flag works such that the default
    instruction name (i_name) is the instruction when the data size
    prefix (0x66) is not specified, and the alternate name in i_extra is
    used when the prefix is included.
  - Add a new 'ADEP' size flag similar to 'SDEP' except that it chooses
    between i_name and i_extra based on the address size prefix (0x67).
    Use this to fix the decoding for jrcxz vs jecxz which is determined
    by the address size prefix, not the operand size prefix.  Also, jcxz
    is not possible in 64-bit mode, but jrcxz is the default instruction
    for that opcode.
  - Add support for handling instructions that have a mandatory 'rep'
    prefix (this means not outputting the 'repe ' prefix until determining
    if it is used as part of an opcode).  Make 'pause' less of a special
    case this way.
  - Decode 'cmpxchg16b' and 'cdqe' which are variants of other instructions
    but with a REX.W prefix.
  
  MFC after:	1 month

Modified:
  head/sys/amd64/amd64/db_disasm.c

Modified: head/sys/amd64/amd64/db_disasm.c
==============================================================================
--- head/sys/amd64/amd64/db_disasm.c	Fri Jul  6 13:21:23 2012	(r238165)
+++ head/sys/amd64/amd64/db_disasm.c	Fri Jul  6 14:25:59 2012	(r238166)
@@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
  * Instruction disassembler.
  */
 #include <sys/param.h>
+#include <sys/libkern.h>
 
 #include <ddb/ddb.h>
 #include <ddb/db_access.h>
@@ -47,7 +48,9 @@ __FBSDID("$FreeBSD$");
 #define	DBLR	5
 #define	EXTR	6
 #define	SDEP	7
-#define	NONE	8
+#define	ADEP	8
+#define	ESC	9
+#define	NONE	10
 
 /*
  * REX prefix and bits
@@ -67,6 +70,7 @@ __FBSDID("$FreeBSD$");
 #define	Eb	4			/* address, byte size */
 #define	R	5			/* register, in 'reg' field */
 #define	Rw	6			/* word register, in 'reg' field */
+#define	Rq	39			/* quad register, in 'reg' field */
 #define	Ri	7			/* register in instruction */
 #define	S	8			/* segment reg, in 'reg' field */
 #define	Si	9			/* segment reg, in instruction */
@@ -120,6 +124,45 @@ struct finst {
 					   (or pointer to table) */
 };
 
+static const struct inst db_inst_0f388x[] = {
+/*80*/	{ "",	   TRUE,  SDEP,  op2(E, Rq),  "invept" },
+/*81*/	{ "",	   TRUE,  SDEP,  op2(E, Rq),  "invvpid" },
+/*82*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*83*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*84*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*85*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*86*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*87*/	{ "",	   FALSE, NONE,  0,	      0 },
+
+/*88*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*89*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8a*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8b*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8c*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8d*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8e*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*8f*/	{ "",	   FALSE, NONE,  0,	      0 },
+};
+
+static const struct inst * const db_inst_0f38[] = {
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	db_inst_0f388x,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0
+};
+
 static const char * const db_Grp6[] = {
 	"sldt",
 	"str",
@@ -160,8 +203,8 @@ static const char * const db_Grp9[] = {
 	"",
 	"",
 	"",
-	"",
-	""
+	"vmptrld",
+	"vmptrst"
 };
 
 static const char * const db_Grp15[] = {
@@ -236,7 +279,7 @@ static const struct inst db_inst_0f3x[] 
 /*36*/	{ "",	   FALSE, NONE,  0,	      0 },
 /*37*/	{ "getsec",FALSE, NONE,  0,	      0 },
 
-/*38*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*38*/	{ "",	   FALSE, ESC,  0,	      db_inst_0f38 },
 /*39*/	{ "",	   FALSE, NONE,  0,	      0 },
 /*3a*/	{ "",	   FALSE, NONE,  0,	      0 },
 /*3b*/	{ "",	   FALSE, NONE,  0,	      0 },
@@ -266,6 +309,26 @@ static const struct inst db_inst_0f4x[] 
 /*4f*/	{ "cmovnle",TRUE, NONE,  op2(E, R),   0 },
 };
 
+static const struct inst db_inst_0f7x[] = {
+/*70*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*71*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*72*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*73*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*74*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*75*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*76*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*77*/	{ "",	   FALSE, NONE,  0,	      0 },
+
+/*78*/	{ "vmread", TRUE, NONE,  op2(Rq, E),  0 },
+/*79*/	{ "vmwrite",TRUE, NONE,  op2(E, Rq),  0 },
+/*7a*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*7b*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*7c*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*7d*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*7e*/	{ "",	   FALSE, NONE,  0,	      0 },
+/*7f*/	{ "",	   FALSE, NONE,  0,	      0 },
+};
+
 static const struct inst db_inst_0f8x[] = {
 /*80*/	{ "jo",    FALSE, NONE,  op1(Dl),     0 },
 /*81*/	{ "jno",   FALSE, NONE,  op1(Dl),     0 },
@@ -373,7 +436,7 @@ static const struct inst * const db_inst
 	db_inst_0f4x,
 	0,
 	0,
-	0,
+	db_inst_0f7x,
 	db_inst_0f8x,
 	db_inst_0f9x,
 	db_inst_0fax,
@@ -582,7 +645,7 @@ static const struct inst db_inst_table[2
 /*0c*/	{ "or",    FALSE, BYTE,  op2(I, A),  0 },
 /*0d*/	{ "or",    FALSE, LONG,  op2(I, A),  0 },
 /*0e*/	{ "push",  FALSE, NONE,  op1(Si),    0 },
-/*0f*/	{ "",      FALSE, NONE,  0,	     0 },
+/*0f*/	{ "",      FALSE, ESC,   0,	     db_inst_0f },
 
 /*10*/	{ "adc",   TRUE,  BYTE,  op2(R, E),  0 },
 /*11*/	{ "adc",   TRUE,  LONG,  op2(R, E),  0 },
@@ -738,8 +801,8 @@ static const struct inst db_inst_table[2
 /*96*/	{ "xchg",  FALSE, LONG,  op2(A, Ri),  0 },
 /*97*/	{ "xchg",  FALSE, LONG,  op2(A, Ri),  0 },
 
-/*98*/	{ "cbw",   FALSE, SDEP,  0,	      "cwde" },	/* cbw/cwde */
-/*99*/	{ "cwd",   FALSE, SDEP,  0,	      "cdq"  },	/* cwd/cdq */
+/*98*/	{ "cwde",  FALSE, SDEP,  0,	      "cbw" },
+/*99*/	{ "cdq",   FALSE, SDEP,  0,	      "cwd" },
 /*9a*/	{ "lcall", FALSE, NONE,  op1(OS),     0 },
 /*9b*/	{ "wait",  FALSE, NONE,  0,	      0 },
 /*9c*/	{ "pushf", FALSE, LONG,  0,	      0 },
@@ -822,7 +885,7 @@ static const struct inst db_inst_table[2
 /*e0*/	{ "loopne",FALSE, NONE,  op1(Db),     0 },
 /*e1*/	{ "loope", FALSE, NONE,  op1(Db),     0 },
 /*e2*/	{ "loop",  FALSE, NONE,  op1(Db),     0 },
-/*e3*/	{ "jcxz",  FALSE, SDEP,  op1(Db),     "jecxz" },
+/*e3*/	{ "jrcxz", FALSE, ADEP,  op1(Db),     "jecxz" },
 /*e4*/	{ "in",    FALSE, BYTE,  op2(Ib, A),  0 },
 /*e5*/	{ "in",    FALSE, LONG,  op2(Ib, A) , 0 },
 /*e6*/	{ "out",   FALSE, BYTE,  op2(A, Ib),  0 },
@@ -1208,14 +1271,6 @@ db_disasm(loc, altfmt)
 	    if (prefix) {
 		get_value_inc(inst, loc, 1, FALSE);
 	    }
-	    if (rep == TRUE) {
-		if (inst == 0x90) {
-		    db_printf("pause\n");
-		    return (loc);
-		}
-		db_printf("repe ");	/* XXX repe VS rep */
-		rep = FALSE;
-	    }
 	} while (prefix);
 
 	if (inst >= 0xd8 && inst <= 0xdf) {
@@ -1224,9 +1279,10 @@ db_disasm(loc, altfmt)
 	    return (loc);
 	}
 
-	if (inst == 0x0f) {
+	ip = &db_inst_table[inst];
+	while (ip->i_size == ESC) {
 	    get_value_inc(inst, loc, 1, FALSE);
-	    ip = db_inst_0f[inst>>4];
+	    ip = ((const struct inst * const *)ip->i_extra)[inst>>4];
 	    if (ip == 0) {
 		ip = &db_bad_inst;
 	    }
@@ -1234,8 +1290,6 @@ db_disasm(loc, altfmt)
 		ip = &ip[inst&0xf];
 	    }
 	}
-	else
-	    ip = &db_inst_table[inst];
 
 	if (ip->i_has_modrm) {
 	    get_value_inc(regmodrm, loc, 1, FALSE);
@@ -1269,6 +1323,26 @@ db_disasm(loc, altfmt)
 	/* Special cases that don't fit well in the tables. */
 	if (ip->i_extra == db_Grp7 && f_mod(rex, regmodrm) == 3) {
 		switch (regmodrm) {
+		case 0xc1:
+			i_name = "vmcall";
+			i_size = NONE;
+			i_mode = 0;
+			break;
+		case 0xc2:
+			i_name = "vmlaunch";
+			i_size = NONE;
+			i_mode = 0;
+			break;
+		case 0xc3:
+			i_name = "vmresume";
+			i_size = NONE;
+			i_mode = 0;
+			break;
+		case 0xc4:
+			i_name = "vmxoff";
+			i_size = NONE;
+			i_mode = 0;
+			break;
 		case 0xc8:
 			i_name = "monitor";
 			i_size = NONE;
@@ -1307,8 +1381,42 @@ db_disasm(loc, altfmt)
 		i_mode = 0;
 	}
 
+	/* Handle instructions identified by mandatory prefixes. */
+	if (rep == TRUE) {
+	    if (inst == 0x90) {
+		i_name = "pause";
+		i_size = NONE;
+		i_mode = 0;
+		rep = FALSE;
+	    } else if (ip->i_extra == db_Grp9 && f_mod(rex, regmodrm) != 3 &&
+		f_reg(rex, regmodrm) == 0x6) {
+		i_name = "vmxon";
+		rep = FALSE;
+	    }
+	}
+	if (size == WORD) {
+	    if (ip->i_extra == db_Grp9 && f_mod(rex, regmodrm) != 3 &&
+		f_reg(rex, regmodrm) == 0x6) {
+		i_name = "vmclear";
+	    }
+	}
+	if (rex & REX_W) {
+	    if (strcmp(i_name, "cwde") == 0)
+		i_name = "cdqe";
+	    else if (strcmp(i_name, "cmpxchg8b") == 0)
+		i_name = "cmpxchg16b";
+	}
+
+	if (rep == TRUE)
+	    db_printf("repe ");	/* XXX repe VS rep */
+
 	if (i_size == SDEP) {
-	    if (size == WORD)
+	    if (size == LONG)
+		db_printf("%s", i_name);
+	    else
+		db_printf("%s", (const char *)ip->i_extra);
+	} else if (i_size == ADEP) {
+	    if (short_addr == FALSE)
 		db_printf("%s", i_name);
 	    else
 		db_printf("%s", (const char *)ip->i_extra);
@@ -1381,6 +1489,10 @@ db_disasm(loc, altfmt)
 		    db_printf("%s", db_reg[rex != 0 ? 1 : 0][WORD][f_reg(rex, regmodrm)]);
 		    break;
 
+		case Rq:
+		    db_printf("%s", db_reg[rex != 0 ? 1 : 0][QUAD][f_reg(rex, regmodrm)]);
+		    break;
+
 		case Ri:
 		    db_printf("%s", db_reg[0][QUAD][f_rm(rex, inst)]);
 		    break;



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