arch/x86/mm/pf_in.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Fault Injection Test harness (FI)
  *  Copyright (C) Intel Crop.
  */

 /*  Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp
  *  Copyright by Intel Crop., 2002
  *  Louis Zhuang (louis.zhuang@intel.com)
  *
  *  Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007
  */

 #include <linux/ptrace.h> /* struct pt_regs */
 #include "pf_in.h"

 #ifdef __i386__
 /* IA32 Manual 3, 2-1 */
 static unsigned char prefix_codes[] = {
 	0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64,
 	0x65, 0x66, 0x67
 };
 /* IA32 Manual 3, 3-432*/
 static unsigned int reg_rop[] = {
 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
 };
 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
 /* IA32 Manual 3, 3-432*/
 static unsigned int rw8[] = { 0x88, 0x8A, 0xC6, 0xAA };
 static unsigned int rw32[] = {
 	0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
 };
 static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F, 0xAA };
 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
 static unsigned int mw32[] = { 0x89, 0x8B, 0xC7, 0xAB };
 static unsigned int mw64[] = {};
 #else /* not __i386__ */
 static unsigned char prefix_codes[] = {
 	0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36,
 	0xF0, 0xF3, 0xF2,
 	/* REX Prefixes */
 	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
 	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
 };
 /* AMD64 Manual 3, Appendix A*/
 static unsigned int reg_rop[] = {
 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
 };
 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
 static unsigned int rw8[] = { 0xC6, 0x88, 0x8A, 0xAA };
 static unsigned int rw32[] = {
 	0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
 };
 /* 8 bit only */
 static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F, 0xAA };
 /* 16 bit only */
 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
 /* 16 or 32 bit */
 static unsigned int mw32[] = { 0xC7 };
 /* 16, 32 or 64 bit */
 static unsigned int mw64[] = { 0x89, 0x8B, 0xAB };
 #endif /* not __i386__ */

 struct prefix_bits {
 	unsigned shorted:1;
 	unsigned enlarged:1;
 	unsigned rexr:1;
 	unsigned rex:1;
 };

 static int skip_prefix(unsigned char *addr, struct prefix_bits *prf)
 {
 	int i;
 	unsigned char *p = addr;
 	prf->shorted = 0;
 	prf->enlarged = 0;
 	prf->rexr = 0;
 	prf->rex = 0;

 restart:
 	for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
 		if (*p == prefix_codes[i]) {
 			if (*p == 0x66)
 				prf->shorted = 1;
 #ifdef __amd64__
 			if ((*p & 0xf8) == 0x48)
 				prf->enlarged = 1;
 			if ((*p & 0xf4) == 0x44)
 				prf->rexr = 1;
 			if ((*p & 0xf0) == 0x40)
 				prf->rex = 1;
 #endif
 			p++;
 			goto restart;
 		}
 	}

 	return (p - addr);
 }

 static int get_opcode(unsigned char *addr, unsigned int *opcode)
 {
 	int len;

 	if (*addr == 0x0F) {
 		/* 0x0F is extension instruction */
 		*opcode = *(unsigned short *)addr;
 		len = 2;
 	} else {
 		*opcode = *addr;
 		len = 1;
 	}

 	return len;
 }

 #define CHECK_OP_TYPE(opcode, array, type) \
 	for (i = 0; i < ARRAY_SIZE(array); i++) { \
 		if (array[i] == opcode) { \
 			rv = type; \
 			goto exit; \
 		} \
 	}

 enum reason_type get_ins_type(unsigned long ins_addr)
 {
 	unsigned int opcode;
 	unsigned char *p;
 	struct prefix_bits prf;
 	int i;
 	enum reason_type rv = OTHERS;

 	p = (unsigned char *)ins_addr;
 	p += skip_prefix(p, &prf);
 	p += get_opcode(p, &opcode);

 	CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
 	CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE);
 	CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE);

 exit:
 	return rv;
 }
 #undef CHECK_OP_TYPE

 static unsigned int get_ins_reg_width(unsigned long ins_addr)
 {
 	unsigned int opcode;
 	unsigned char *p;
 	struct prefix_bits prf;
 	int i;

 	p = (unsigned char *)ins_addr;
 	p += skip_prefix(p, &prf);
 	p += get_opcode(p, &opcode);

 	for (i = 0; i < ARRAY_SIZE(rw8); i++)
 		if (rw8[i] == opcode)
 			return 1;

 	for (i = 0; i < ARRAY_SIZE(rw32); i++)
 		if (rw32[i] == opcode)
 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);

 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
 	return 0;
 }

 unsigned int get_ins_mem_width(unsigned long ins_addr)
 {
 	unsigned int opcode;
 	unsigned char *p;
 	struct prefix_bits prf;
 	int i;

 	p = (unsigned char *)ins_addr;
 	p += skip_prefix(p, &prf);
 	p += get_opcode(p, &opcode);

 	for (i = 0; i < ARRAY_SIZE(mw8); i++)
 		if (mw8[i] == opcode)
 			return 1;

 	for (i = 0; i < ARRAY_SIZE(mw16); i++)
 		if (mw16[i] == opcode)
 			return 2;

 	for (i = 0; i < ARRAY_SIZE(mw32); i++)
 		if (mw32[i] == opcode)
 			return prf.shorted ? 2 : 4;

 	for (i = 0; i < ARRAY_SIZE(mw64); i++)
 		if (mw64[i] == opcode)
 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);

 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
 	return 0;
 }

 /*
  * Define register ident in mod/rm byte.
  * Note: these are NOT the same as in ptrace-abi.h.
  */
 enum {
 	arg_AL = 0,
 	arg_CL = 1,
 	arg_DL = 2,
 	arg_BL = 3,
 	arg_AH = 4,
 	arg_CH = 5,
 	arg_DH = 6,
 	arg_BH = 7,

 	arg_AX = 0,
 	arg_CX = 1,
 	arg_DX = 2,
 	arg_BX = 3,
 	arg_SP = 4,
 	arg_BP = 5,
 	arg_SI = 6,
 	arg_DI = 7,
 #ifdef __amd64__
 	arg_R8  = 8,
 	arg_R9  = 9,
 	arg_R10 = 10,
 	arg_R11 = 11,
 	arg_R12 = 12,
 	arg_R13 = 13,
 	arg_R14 = 14,
 	arg_R15 = 15
 #endif
 };

 static unsigned char *get_reg_w8(int no, int rex, struct pt_regs *regs)
 {
 	unsigned char *rv = NULL;

 	switch (no) {
 	case arg_AL:
 		rv = (unsigned char *)&regs->ax;
 		break;
 	case arg_BL:
 		rv = (unsigned char *)&regs->bx;
 		break;
 	case arg_CL:
 		rv = (unsigned char *)&regs->cx;
 		break;
 	case arg_DL:
 		rv = (unsigned char *)&regs->dx;
 		break;
 #ifdef __amd64__
 	case arg_R8:
 		rv = (unsigned char *)&regs->r8;
 		break;
 	case arg_R9:
 		rv = (unsigned char *)&regs->r9;
 		break;
 	case arg_R10:
 		rv = (unsigned char *)&regs->r10;
 		break;
 	case arg_R11:
 		rv = (unsigned char *)&regs->r11;
 		break;
 	case arg_R12:
 		rv = (unsigned char *)&regs->r12;
 		break;
 	case arg_R13:
 		rv = (unsigned char *)&regs->r13;
 		break;
 	case arg_R14:
 		rv = (unsigned char *)&regs->r14;
 		break;
 	case arg_R15:
 		rv = (unsigned char *)&regs->r15;
 		break;
 #endif
 	default:
 		break;
 	}

 	if (rv)
 		return rv;

 	if (rex) {
 		/*
 		 * If REX prefix exists, access low bytes of SI etc.
 		 * instead of AH etc.
 		 */
 		switch (no) {
 		case arg_SI:
 			rv = (unsigned char *)&regs->si;
 			break;
 		case arg_DI:
 			rv = (unsigned char *)&regs->di;
 			break;
 		case arg_BP:
 			rv = (unsigned char *)&regs->bp;
 			break;
 		case arg_SP:
 			rv = (unsigned char *)&regs->sp;
 			break;
 		default:
 			break;
 		}
 	} else {
 		switch (no) {
 		case arg_AH:
 			rv = 1 + (unsigned char *)&regs->ax;
 			break;
 		case arg_BH:
 			rv = 1 + (unsigned char *)&regs->bx;
 			break;
 		case arg_CH:
 			rv = 1 + (unsigned char *)&regs->cx;
 			break;
 		case arg_DH:
 			rv = 1 + (unsigned char *)&regs->dx;
 			break;
 		default:
 			break;
 		}
 	}

 	if (!rv)
 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);

 	return rv;
 }

 static unsigned long *get_reg_w32(int no, struct pt_regs *regs)
 {
 	unsigned long *rv = NULL;

 	switch (no) {
 	case arg_AX:
 		rv = &regs->ax;
 		break;
 	case arg_BX:
 		rv = &regs->bx;
 		break;
 	case arg_CX:
 		rv = &regs->cx;
 		break;
 	case arg_DX:
 		rv = &regs->dx;
 		break;
 	case arg_SP:
 		rv = &regs->sp;
 		break;
 	case arg_BP:
 		rv = &regs->bp;
 		break;
 	case arg_SI:
 		rv = &regs->si;
 		break;
 	case arg_DI:
 		rv = &regs->di;
 		break;
 #ifdef __amd64__
 	case arg_R8:
 		rv = &regs->r8;
 		break;
 	case arg_R9:
 		rv = &regs->r9;
 		break;
 	case arg_R10:
 		rv = &regs->r10;
 		break;
 	case arg_R11:
 		rv = &regs->r11;
 		break;
 	case arg_R12:
 		rv = &regs->r12;
 		break;
 	case arg_R13:
 		rv = &regs->r13;
 		break;
 	case arg_R14:
 		rv = &regs->r14;
 		break;
 	case arg_R15:
 		rv = &regs->r15;
 		break;
 #endif
 	default:
 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
 	}

 	return rv;
 }

 unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
 {
 	unsigned int opcode;
 	int reg;
 	unsigned char *p;
 	struct prefix_bits prf;
 	int i;

 	p = (unsigned char *)ins_addr;
 	p += skip_prefix(p, &prf);
 	p += get_opcode(p, &opcode);
 	for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
 		if (reg_rop[i] == opcode)
 			goto do_work;

 	for (i = 0; i < ARRAY_SIZE(reg_wop); i++)
 		if (reg_wop[i] == opcode)
 			goto do_work;

 	printk(KERN_ERR "mmiotrace: Not a register instruction, opcode "
 							"0x%02x\n", opcode);
 	goto err;

 do_work:
 	/* for STOS, source register is fixed */
 	if (opcode == 0xAA || opcode == 0xAB) {
 		reg = arg_AX;
 	} else {
 		unsigned char mod_rm = *p;
 		reg = ((mod_rm >> 3) & 0x7) | (prf.rexr << 3);
 	}
 	switch (get_ins_reg_width(ins_addr)) {
 	case 1:
 		return *get_reg_w8(reg, prf.rex, regs);

 	case 2:
 		return *(unsigned short *)get_reg_w32(reg, regs);

 	case 4:
 		return *(unsigned int *)get_reg_w32(reg, regs);

 #ifdef __amd64__
 	case 8:
 		return *(unsigned long *)get_reg_w32(reg, regs);
 #endif

 	default:
 		printk(KERN_ERR "mmiotrace: Error width# %d\n", reg);
 	}

 err:
 	return 0;
 }

 unsigned long get_ins_imm_val(unsigned long ins_addr)
 {
 	unsigned int opcode;
 	unsigned char mod_rm;
 	unsigned char mod;
 	unsigned char *p;
 	struct prefix_bits prf;
 	int i;

 	p = (unsigned char *)ins_addr;
 	p += skip_prefix(p, &prf);
 	p += get_opcode(p, &opcode);
 	for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
 		if (imm_wop[i] == opcode)
 			goto do_work;

 	printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode "
 							"0x%02x\n", opcode);
 	goto err;

 do_work:
 	mod_rm = *p;
 	mod = mod_rm >> 6;
 	p++;
 	switch (mod) {
 	case 0:
 		/* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2)  */
 		/* AMD64: XXX Check for address size prefix? */
 		if ((mod_rm & 0x7) == 0x5)
 			p += 4;
 		break;

 	case 1:
 		p += 1;
 		break;

 	case 2:
 		p += 4;
 		break;

 	case 3:
 	default:
 		printk(KERN_ERR "mmiotrace: not a memory access instruction "
 						"at 0x%lx, rm_mod=0x%02x\n",
 						ins_addr, mod_rm);
 	}

 	switch (get_ins_reg_width(ins_addr)) {
 	case 1:
 		return *(unsigned char *)p;

 	case 2:
 		return *(unsigned short *)p;

 	case 4:
 		return *(unsigned int *)p;

 #ifdef __amd64__
 	case 8:
 		return *(unsigned long *)p;
 #endif

 	default:
 		printk(KERN_ERR "mmiotrace: Error: width.\n");
 	}

 err:
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Fault Injection Test harness (FI)
	* Copyright (C) Intel Crop.
	*/

	/* Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp
	* Copyright by Intel Crop., 2002
	* Louis Zhuang (louis.zhuang@intel.com)
	*
	* Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007
	*/

	#include <linux/ptrace.h> /* struct pt_regs */
	#include "pf_in.h"

	#ifdef __i386__
	/* IA32 Manual 3, 2-1 */
	static unsigned char prefix_codes[] = {
	0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64,
	0x65, 0x66, 0x67
	};
	/* IA32 Manual 3, 3-432*/
	static unsigned int reg_rop[] = {
	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
	};
	static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
	static unsigned int imm_wop[] = { 0xC6, 0xC7 };
	/* IA32 Manual 3, 3-432*/
	static unsigned int rw8[] = { 0x88, 0x8A, 0xC6, 0xAA };
	static unsigned int rw32[] = {
	0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
	};
	static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F, 0xAA };
	static unsigned int mw16[] = { 0xB70F, 0xBF0F };
	static unsigned int mw32[] = { 0x89, 0x8B, 0xC7, 0xAB };
	static unsigned int mw64[] = {};
	#else /* not __i386__ */
	static unsigned char prefix_codes[] = {
	0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36,
	0xF0, 0xF3, 0xF2,
	/* REX Prefixes */
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
	};
	/* AMD64 Manual 3, Appendix A*/
	static unsigned int reg_rop[] = {
	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
	};
	static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
	static unsigned int imm_wop[] = { 0xC6, 0xC7 };
	static unsigned int rw8[] = { 0xC6, 0x88, 0x8A, 0xAA };
	static unsigned int rw32[] = {
	0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
	};
	/* 8 bit only */
	static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F, 0xAA };
	/* 16 bit only */
	static unsigned int mw16[] = { 0xB70F, 0xBF0F };
	/* 16 or 32 bit */
	static unsigned int mw32[] = { 0xC7 };
	/* 16, 32 or 64 bit */
	static unsigned int mw64[] = { 0x89, 0x8B, 0xAB };
	#endif /* not __i386__ */

	struct prefix_bits {
	unsigned shorted:1;
	unsigned enlarged:1;
	unsigned rexr:1;
	unsigned rex:1;
	};

	static int skip_prefix(unsigned char addr, struct prefix_bits prf)
	{
	int i;
	unsigned char *p = addr;
	prf->shorted = 0;
	prf->enlarged = 0;
	prf->rexr = 0;
	prf->rex = 0;

	restart:
	for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
	if (*p == prefix_codes[i]) {
	if (*p == 0x66)
	prf->shorted = 1;
	#ifdef __amd64__
	if ((*p & 0xf8) == 0x48)
	prf->enlarged = 1;
	if ((*p & 0xf4) == 0x44)
	prf->rexr = 1;
	if ((*p & 0xf0) == 0x40)
	prf->rex = 1;
	#endif
	p++;
	goto restart;
	}
	}

	return (p - addr);
	}

	static int get_opcode(unsigned char addr, unsigned int opcode)
	{
	int len;

	if (*addr == 0x0F) {
	/* 0x0F is extension instruction */
	opcode = (unsigned short *)addr;
	len = 2;
	} else {
	opcode = addr;
	len = 1;
	}

	return len;
	}

	#define CHECK_OP_TYPE(opcode, array, type) \
	for (i = 0; i < ARRAY_SIZE(array); i++) { \
	if (array[i] == opcode) { \
	rv = type; \
	goto exit; \
	} \
	}

	enum reason_type get_ins_type(unsigned long ins_addr)
	{
	unsigned int opcode;
	unsigned char *p;
	struct prefix_bits prf;
	int i;
	enum reason_type rv = OTHERS;

	p = (unsigned char *)ins_addr;
	p += skip_prefix(p, &prf);
	p += get_opcode(p, &opcode);

	CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
	CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE);
	CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE);

	exit:
	return rv;
	}
	#undef CHECK_OP_TYPE

	static unsigned int get_ins_reg_width(unsigned long ins_addr)
	{
	unsigned int opcode;
	unsigned char *p;
	struct prefix_bits prf;
	int i;

	p = (unsigned char *)ins_addr;
	p += skip_prefix(p, &prf);
	p += get_opcode(p, &opcode);

	for (i = 0; i < ARRAY_SIZE(rw8); i++)
	if (rw8[i] == opcode)
	return 1;

	for (i = 0; i < ARRAY_SIZE(rw32); i++)
	if (rw32[i] == opcode)
	return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);

	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
	return 0;
	}

	unsigned int get_ins_mem_width(unsigned long ins_addr)
	{
	unsigned int opcode;
	unsigned char *p;
	struct prefix_bits prf;
	int i;

	p = (unsigned char *)ins_addr;
	p += skip_prefix(p, &prf);
	p += get_opcode(p, &opcode);

	for (i = 0; i < ARRAY_SIZE(mw8); i++)
	if (mw8[i] == opcode)
	return 1;

	for (i = 0; i < ARRAY_SIZE(mw16); i++)
	if (mw16[i] == opcode)
	return 2;

	for (i = 0; i < ARRAY_SIZE(mw32); i++)
	if (mw32[i] == opcode)
	return prf.shorted ? 2 : 4;

	for (i = 0; i < ARRAY_SIZE(mw64); i++)
	if (mw64[i] == opcode)
	return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);

	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
	return 0;
	}

	/*
	* Define register ident in mod/rm byte.
	* Note: these are NOT the same as in ptrace-abi.h.
	*/
	enum {
	arg_AL = 0,
	arg_CL = 1,
	arg_DL = 2,
	arg_BL = 3,
	arg_AH = 4,
	arg_CH = 5,
	arg_DH = 6,
	arg_BH = 7,

	arg_AX = 0,
	arg_CX = 1,
	arg_DX = 2,
	arg_BX = 3,
	arg_SP = 4,
	arg_BP = 5,
	arg_SI = 6,
	arg_DI = 7,
	#ifdef __amd64__
	arg_R8 = 8,
	arg_R9 = 9,
	arg_R10 = 10,
	arg_R11 = 11,
	arg_R12 = 12,
	arg_R13 = 13,
	arg_R14 = 14,
	arg_R15 = 15
	#endif
	};

	static unsigned char get_reg_w8(int no, int rex, struct pt_regs regs)
	{
	unsigned char *rv = NULL;

	switch (no) {
	case arg_AL:
	rv = (unsigned char *)&regs->ax;
	break;
	case arg_BL:
	rv = (unsigned char *)&regs->bx;
	break;
	case arg_CL:
	rv = (unsigned char *)&regs->cx;
	break;
	case arg_DL:
	rv = (unsigned char *)&regs->dx;
	break;
	#ifdef __amd64__
	case arg_R8:
	rv = (unsigned char *)&regs->r8;
	break;
	case arg_R9:
	rv = (unsigned char *)&regs->r9;
	break;
	case arg_R10:
	rv = (unsigned char *)&regs->r10;
	break;
	case arg_R11:
	rv = (unsigned char *)&regs->r11;
	break;
	case arg_R12:
	rv = (unsigned char *)&regs->r12;
	break;
	case arg_R13:
	rv = (unsigned char *)&regs->r13;
	break;
	case arg_R14:
	rv = (unsigned char *)&regs->r14;
	break;
	case arg_R15:
	rv = (unsigned char *)&regs->r15;
	break;
	#endif
	default:
	break;
	}

	if (rv)
	return rv;

	if (rex) {
	/*
	* If REX prefix exists, access low bytes of SI etc.
	* instead of AH etc.
	*/
	switch (no) {
	case arg_SI:
	rv = (unsigned char *)&regs->si;
	break;
	case arg_DI:
	rv = (unsigned char *)&regs->di;
	break;
	case arg_BP:
	rv = (unsigned char *)&regs->bp;
	break;
	case arg_SP:
	rv = (unsigned char *)&regs->sp;
	break;
	default:
	break;
	}
	} else {
	switch (no) {
	case arg_AH:
	rv = 1 + (unsigned char *)&regs->ax;
	break;
	case arg_BH:
	rv = 1 + (unsigned char *)&regs->bx;
	break;
	case arg_CH:
	rv = 1 + (unsigned char *)&regs->cx;
	break;
	case arg_DH:
	rv = 1 + (unsigned char *)&regs->dx;
	break;
	default:
	break;
	}
	}

	if (!rv)
	printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);

	return rv;
	}

	static unsigned long get_reg_w32(int no, struct pt_regs regs)
	{
	unsigned long *rv = NULL;

	switch (no) {
	case arg_AX:
	rv = &regs->ax;
	break;
	case arg_BX:
	rv = &regs->bx;
	break;
	case arg_CX:
	rv = &regs->cx;
	break;
	case arg_DX:
	rv = &regs->dx;
	break;
	case arg_SP:
	rv = &regs->sp;
	break;
	case arg_BP:
	rv = &regs->bp;
	break;
	case arg_SI:
	rv = &regs->si;
	break;
	case arg_DI:
	rv = &regs->di;
	break;
	#ifdef __amd64__
	case arg_R8:
	rv = &regs->r8;
	break;
	case arg_R9:
	rv = &regs->r9;
	break;
	case arg_R10:
	rv = &regs->r10;
	break;
	case arg_R11:
	rv = &regs->r11;
	break;
	case arg_R12:
	rv = &regs->r12;
	break;
	case arg_R13:
	rv = &regs->r13;
	break;
	case arg_R14:
	rv = &regs->r14;
	break;
	case arg_R15:
	rv = &regs->r15;
	break;
	#endif
	default:
	printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
	}

	return rv;
	}

	unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
	{
	unsigned int opcode;
	int reg;
	unsigned char *p;
	struct prefix_bits prf;
	int i;

	p = (unsigned char *)ins_addr;
	p += skip_prefix(p, &prf);
	p += get_opcode(p, &opcode);
	for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
	if (reg_rop[i] == opcode)
	goto do_work;

	for (i = 0; i < ARRAY_SIZE(reg_wop); i++)
	if (reg_wop[i] == opcode)
	goto do_work;

	printk(KERN_ERR "mmiotrace: Not a register instruction, opcode "
	"0x%02x\n", opcode);
	goto err;

	do_work:
	/* for STOS, source register is fixed */
	if (opcode == 0xAA \|\| opcode == 0xAB) {
	reg = arg_AX;
	} else {
	unsigned char mod_rm = *p;
	reg = ((mod_rm >> 3) & 0x7) \| (prf.rexr << 3);
	}
	switch (get_ins_reg_width(ins_addr)) {
	case 1:
	return *get_reg_w8(reg, prf.rex, regs);

	case 2:
	return (unsigned short )get_reg_w32(reg, regs);

	case 4:
	return (unsigned int )get_reg_w32(reg, regs);

	#ifdef __amd64__
	case 8:
	return (unsigned long )get_reg_w32(reg, regs);
	#endif

	default:
	printk(KERN_ERR "mmiotrace: Error width# %d\n", reg);
	}

	err:
	return 0;
	}

	unsigned long get_ins_imm_val(unsigned long ins_addr)
	{
	unsigned int opcode;
	unsigned char mod_rm;
	unsigned char mod;
	unsigned char *p;
	struct prefix_bits prf;
	int i;

	p = (unsigned char *)ins_addr;
	p += skip_prefix(p, &prf);
	p += get_opcode(p, &opcode);
	for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
	if (imm_wop[i] == opcode)
	goto do_work;

	printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode "
	"0x%02x\n", opcode);
	goto err;

	do_work:
	mod_rm = *p;
	mod = mod_rm >> 6;
	p++;
	switch (mod) {
	case 0:
	/* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2) */
	/* AMD64: XXX Check for address size prefix? */
	if ((mod_rm & 0x7) == 0x5)
	p += 4;
	break;

	case 1:
	p += 1;
	break;

	case 2:
	p += 4;
	break;

	case 3:
	default:
	printk(KERN_ERR "mmiotrace: not a memory access instruction "
	"at 0x%lx, rm_mod=0x%02x\n",
	ins_addr, mod_rm);
	}

	switch (get_ins_reg_width(ins_addr)) {
	case 1:
	return (unsigned char )p;

	case 2:
	return (unsigned short )p;

	case 4:
	return (unsigned int )p;

	#ifdef __amd64__
	case 8:
	return (unsigned long )p;
	#endif

	default:
	printk(KERN_ERR "mmiotrace: Error: width.\n");
	}

	err:
	return 0;
	}