[Midnightbsd-cvs] src [7942] trunk/sys/amd64/amd64/db_disasm.c: Several fixes to the amd64 disassembler:
laffer1 at midnightbsd.org
laffer1 at midnightbsd.org
Wed Sep 14 17:49:47 EDT 2016
Revision: 7942
http://svnweb.midnightbsd.org/src/?rev=7942
Author: laffer1
Date: 2016-09-14 17:49:46 -0400 (Wed, 14 Sep 2016)
Log Message:
-----------
Several fixes to the amd64 disassembler:
- Decode the 'xsave', 'xrstor', 'xsaveopt', 'xgetbv', 'xsetbv', and
'rdtscp' instructions.
- 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.
Obtained from: FreeBSD
Modified Paths:
--------------
trunk/sys/amd64/amd64/db_disasm.c
Modified: trunk/sys/amd64/amd64/db_disasm.c
===================================================================
--- trunk/sys/amd64/amd64/db_disasm.c 2016-09-14 21:45:47 UTC (rev 7941)
+++ trunk/sys/amd64/amd64/db_disasm.c 2016-09-14 21:49:46 UTC (rev 7942)
@@ -31,6 +31,7 @@
* Instruction disassembler.
*/
#include <sys/param.h>
+#include <sys/libkern.h>
#include <ddb/ddb.h>
#include <ddb/db_access.h>
@@ -47,7 +48,9 @@
#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 @@
#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 @@
(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 @@
"",
"",
"",
- "",
- ""
+ "vmptrld",
+ "vmptrst"
};
static const char * const db_Grp15[] = {
@@ -169,9 +212,9 @@
"fxrstor",
"ldmxcsr",
"stmxcsr",
- "",
- "",
- "",
+ "xsave",
+ "xrstor",
+ "xsaveopt",
"clflush"
};
@@ -236,7 +279,7 @@
/*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 @@
/*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 @@
db_inst_0f4x,
0,
0,
- 0,
+ db_inst_0f7x,
db_inst_0f8x,
db_inst_0f9x,
db_inst_0fax,
@@ -582,7 +645,7 @@
/*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 @@
/*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 @@
/*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 @@
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 @@
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 @@
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 @@
/* 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;
@@ -1279,11 +1353,26 @@
i_size = NONE;
i_mode = 0;
break;
+ case 0xd0:
+ i_name = "xgetbv";
+ i_size = NONE;
+ i_mode = 0;
+ break;
+ case 0xd1:
+ i_name = "xsetbv";
+ i_size = NONE;
+ i_mode = 0;
+ break;
case 0xf8:
i_name = "swapgs";
i_size = NONE;
i_mode = 0;
break;
+ case 0xf9:
+ i_name = "rdtscp";
+ i_size = NONE;
+ i_mode = 0;
+ break;
}
}
if (ip->i_extra == db_Grp15 && f_mod(rex, regmodrm) == 3) {
@@ -1292,11 +1381,45 @@
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);
}
else {
db_printf("%s", i_name);
@@ -1366,6 +1489,10 @@
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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