emit-inline.c

二进制翻译的一个软件

  case GP_REG_EAX:
    restore_from = MREG(M, eax);
    break;
  case GP_REG_EBX:
    restore_from = MREG(M, ebx);
    break;
  case GP_REG_ECX:
    restore_from = MREG(M, ecx);
    break;
  case GP_REG_EDX:
    restore_from = MREG(M, edx);
    break;
  case GP_REG_ESI:
    restore_from = MREG(M, esi);
    break;
  case GP_REG_EDI:
    restore_from = MREG(M, edi);
    break;
  case GP_REG_EBP:
    restore_from = MREG(M, ebp);
    break;
  case GP_REG_ESP:
    restore_from = MREG(M, esp);
    break;
  default:
    panic("bb_emit_restore_reg() called with unknown register\n");
    break;
  }

  bb_emit_restore_reg_from(M, whichReg, restore_from);
}

/* The following function is highly sensitive as the emitted code's size is used for computing something else */
INLINE void
bb_emit_store_immediate_to(machine_t *M, unsigned long imm, unsigned long dest)
{
  //bb_emit_byte(M, 0x65u); /* GS Segment Override Prefix - for accessing the M structure */
  bb_emit_byte(M, 0xc7u); /* mov immediate to memory */
  bb_emit_byte(M, 0x05u); /* 00 000 101 */
  bb_emit_w32(M, dest);   /* M dest */
  bb_emit_w32(M, imm);    /* imm32 */
}

/**************************************************************************************************************/

INLINE void
bb_emit_get_2_bytes_into_M(machine_t *M, decode_t *d, unsigned long addr)
{
  modrm_union modrm;
  unsigned reg = GP_REG_EAX;
  modrm.byte = (d->modrm).byte;

  if (modrm.parts.mod == 0x3u)
    {
      /* Required value is contained in register /modrm.parts.rm/. Save that register to the appropriate field of M */
      bb_emit_16_bit_save_reg_to(M, d->modrm.parts.rm, addr);
      return;
    }

  /* Free up the selected register to hold temporary */
  bb_emit_save_reg(M, reg);

  modrm.parts.reg = reg;
 
  if (d->flags & DSFL_GROUP2_PREFIX)
    bb_emit_byte(M, d->Group2_Prefix);
  
  bb_emit_byte(M, 0x66u);	/* Operand-size override prefix */

  if (d->flags & DSFL_GROUP4_PREFIX)
    bb_emit_byte (M, d->Group4_Prefix);

  bb_emit_byte(M, 0x8bu);	/* (16-bit) mov instruction */
  bb_emit_byte(M, modrm.byte);

  if (d->need_sib) 
    bb_emit_byte (M, d->sib.byte);

  switch(d->dispBytes) {
  case 1:
    bb_emit_byte(M, d->displacement);
    break;
  case 2:
    bb_emit_w16(M, d->displacement);
    break;
  case 4:
    bb_emit_w32(M, d->displacement);
    break;
  }

  /* Required value is now contained in register /reg/. Copy that
     to the appropriate field of M */
  bb_emit_16_bit_save_reg_to(M, reg, addr);

  /* Restore the register that we used as scratch register */
  bb_emit_restore_reg(M, reg);
}

INLINE void
bb_emit_get_4_bytes_into_M(machine_t *M, decode_t * d, unsigned long addr)
{
  modrm_union modrm;
  unsigned reg = GP_REG_EAX;
  modrm.byte = (d->modrm).byte;

  if (modrm.parts.mod == 0x3u)
    {
      /* Required value is contained in register /modrm.parts.rm/. Save that register to the appropriate field of M */
      bb_emit_save_reg_to(M, d->modrm.parts.rm, addr);
      return;
    }

  /* Free up the selected register to hold temporary */
  bb_emit_save_reg(M, reg);

  modrm.parts.reg = reg;
  
  if (d->flags & DSFL_GROUP2_PREFIX)
    bb_emit_byte (M, d->Group2_Prefix);
  
  if (d->flags & DSFL_GROUP4_PREFIX)
    bb_emit_byte (M, d->Group4_Prefix);

  bb_emit_byte(M, 0x8bu);	/* (32-bit) mov instruction */
  bb_emit_byte(M, modrm.byte);

  if (d->need_sib) 
    bb_emit_byte (M, d->sib.byte);

  switch(d->dispBytes) {
  case 1:
    bb_emit_byte(M, d->displacement);
    break;
  case 2:
    bb_emit_w16(M, d->displacement);
    break;
  case 4:
    bb_emit_w32(M, d->displacement);
    break;
  }

  /* Required value is now contained in register /reg/. Copy that
     to the appropriate field of M */
  bb_emit_save_reg_to(M, reg, addr);

  /* Restore the register that we used as scratch register */
  bb_emit_restore_reg(M, reg);
}

INLINE void
bb_emit_push_rm(machine_t *M, decode_t * d)
{
  modrm_union modrm;
  modrm.byte = (d->modrm).byte;

  modrm.parts.reg = 0x6u;
  
  if (d->flags & DSFL_GROUP2_PREFIX)
    bb_emit_byte (M, d->Group2_Prefix);
  
  if (d->flags & DSFL_GROUP4_PREFIX) { 
    bb_emit_byte (M, d->Group4_Prefix);
    panic("16 bit mode encountered\n");
  }

  /* Push FF /6*/
  bb_emit_byte(M, 0xFFu);
  bb_emit_byte(M, modrm.byte);

  if (d->need_sib) 
    bb_emit_byte (M, d->sib.byte);

  switch(d->dispBytes) {
  case 1:
    bb_emit_byte(M, d->displacement);
    break;
  case 2:
    bb_emit_w16(M, d->displacement);
    break;
  case 4:
    bb_emit_w32(M, d->displacement);
    break;
  }
}

INLINE void
bb_emit_lw_inc(machine_t *M, unsigned long addr) // [len 8b]
{
  bb_emit_byte(M, 0xFFu);  // INC FF/0
  bb_emit_byte(M, 0x05u);  // 00 000 101 
  bb_emit_w32(M, addr);
}

INLINE void
bb_emit_nop_inc(machine_t *M, unsigned long addr) // [len 8b]
{
  bb_emit_byte (M, 0x90u); // nop
  bb_emit_byte(M, 0xFFu);  // INC FF/0
  bb_emit_byte(M, 0x05u);  // 00 000 101 
  bb_emit_w32(M, addr);
  bb_emit_byte (M, 0x90u); // nop
}

INLINE void
bb_emit_inc(machine_t *M, unsigned long addr) // [len 8b]
{
  bb_emit_byte (M, 0x9Cu); //Pushf
  bb_emit_byte(M, 0xFFu);  // INC FF/0
  bb_emit_byte(M, 0x05u);  // 00 000 101 
  bb_emit_w32(M, addr);
  bb_emit_byte (M, 0x9Du); //Popf
}


INLINE void
bb_emit_lea_inc(machine_t *M, unsigned long addr)
{
  // Push %eax
  bb_emit_byte(M, 0x50u);
  
  // Mov (addr), %eax
  bb_emit_byte(M, 0x8bu); // 8b /r
  bb_emit_byte(M, 0x05u); // 00 000 101
  bb_emit_w32(M, addr);   
  
  // leal 1(%eax), %eax // 8D /r
  bb_emit_byte(M, 0x8du);
  bb_emit_byte(M, 0x40u); // 01 000 000
  bb_emit_byte(M, 0x01u);
  
  // mov %eax, (addr)
  bb_emit_byte(M, 0x89u); // 8b /r
  bb_emit_byte(M, 0x05u); // 00 000 101
  bb_emit_w32(M, addr);   

  // pop %eax
  bb_emit_byte(M, 0x58u);
}


/* Emit a call-back routine. Takes a pointer to the location holding
   the function pointer, and a single argument to be passed to the 
   emitted function */
INLINE void
bb_emit_call_back(machine_t *M, unsigned long fpp, unsigned long arg)
{
  bb_emit_byte(M, 0x9cu);		/* PUSHF */
  bb_emit_byte(M, 0x60u);		/* PUSHA */
  
  // Push arg
  bb_emit_byte(M, 0x68u);
  bb_emit_w32(M, arg);
  
  // call fpp
  bb_emit_call(M, (unsigned char *)fpp);
  
  // leal 4(%esp), %esp
  bb_emit_byte(M, 0x8du);
  bb_emit_byte(M, 0xA4u); /* 10 100 100 */
  bb_emit_byte(M, 0x24u); /* 00 100 100 */
  bb_emit_w32(M, 0x4u);

  bb_emit_byte(M, 0x61u);		/* POPA */
  bb_emit_byte(M, 0x9du);		/* POPF */
}

/* Emit a call-back routine. Takes a pointer to the location holding
   the function pointer, and 2 arguments to be passed to the 
   emitted function */
INLINE void
bb_emit_call_back3(machine_t *M, unsigned long fpp, 
		   unsigned long arg1,
		   unsigned long arg2,
		   unsigned long arg3)
{
  bb_emit_byte(M, 0x9cu);		/* PUSHF */
  bb_emit_byte(M, 0x60u);		/* PUSHA */

  // Push arg3
  bb_emit_byte(M, 0x68u);
  bb_emit_w32(M, arg3);

  // Push arg2
  bb_emit_byte(M, 0x68u);
  bb_emit_w32(M, arg2);

  // Push arg1
  bb_emit_byte(M, 0x68u);
  bb_emit_w32(M, arg1);
  
  // call fpp
  bb_emit_call(M, (unsigned char *)fpp);

  // leal 12(%esp), %esp
  bb_emit_byte(M, 0x8du);
  bb_emit_byte(M, 0xA4u); /* 10 100 100 */
  bb_emit_byte(M, 0x24u); /* 00 100 100 */
  bb_emit_w32(M, 0xCu);

  bb_emit_byte(M, 0x61u);		/* POPA */
  bb_emit_byte(M, 0x9du);		/* POPF */
}