ReceiveTempSMS
/
Sweden-Number
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ntoskrnl: Emulate 'mov Eb, Gb' instruction on x86 processor architecture.

This commit is contained in:
Sebastian Lackner 2014-11-10 07:14:48 +01:00 committed by Alexandre Julliard
parent 8f0d5a37a3
commit b61d93a6b7
1 changed files with 28 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
dlls/ntoskrnl.exe/instr.c
View File

@ -59,7 +59,7 @@ static inline struct idtr get_idtr(void)
}
/* store an operand into a register */
static void store_reg( CONTEXT *context, BYTE regmodrm, const BYTE *addr, int long_op )
static void store_reg_word( CONTEXT *context, BYTE regmodrm, const BYTE *addr, int long_op )
{
switch((regmodrm >> 3) & 7)
{
@ -98,6 +98,22 @@ static void store_reg( CONTEXT *context, BYTE regmodrm, const BYTE *addr, int lo
}
}
/* store an operand into a byte register */
static void store_reg_byte( CONTEXT *context, BYTE regmodrm, const BYTE *addr )
{
switch((regmodrm >> 3) & 7)
{
case 0: context->Eax = (context->Eax & 0xffffff00) | *addr; break;
case 1: context->Ecx = (context->Ecx & 0xffffff00) | *addr; break;
case 2: context->Edx = (context->Edx & 0xffffff00) | *addr; break;
case 3: context->Ebx = (context->Ebx & 0xffffff00) | *addr; break;
case 4: context->Eax = (context->Eax & 0xffff00ff) | (*addr << 8); break;
case 5: context->Ecx = (context->Ecx & 0xffff00ff) | (*addr << 8); break;
case 6: context->Edx = (context->Edx & 0xffff00ff) | (*addr << 8); break;
case 7: context->Ebx = (context->Ebx & 0xffff00ff) | (*addr << 8); break;
}
}
/***********************************************************************
* INSTR_GetOperandAddr
*
@ -404,19 +420,26 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context )
}
break; /* Unable to emulate it */
case 0x8a: /* mov Eb, Gb */
case 0x8b: /* mov Ev, Gv */
{
BYTE *addr = INSTR_GetOperandAddr(context, instr + 1, long_addr,
BYTE *data = INSTR_GetOperandAddr(context, instr + 1, long_addr,
segprefix, &len);
unsigned int data_size = (*instr == 0x8b) ? (long_op ? 4 : 2) : 1;
struct idtr idtr = get_idtr();
unsigned int offset = addr - idtr.base;
unsigned int offset = data - idtr.base;
if (offset <= idtr.limit + 1 - (long_op ? 4 : 2))
if (offset <= idtr.limit + 1 - data_size)
{
idt[1].LimitLow = 0x100; /* FIXME */
idt[2].LimitLow = 0x11E; /* FIXME */
idt[3].LimitLow = 0x500; /* FIXME */
store_reg( context, instr[1], (BYTE *)idt + offset, long_op );
switch (*instr)
{
case 0x8a: store_reg_byte( context, instr[1], (BYTE *)idt + offset ); break;
case 0x8b: store_reg_word( context, instr[1], (BYTE *)idt + offset, long_op ); break;
}
context->Eip += prefixlen + len + 1;
return ExceptionContinueExecution;
}