Sweden-Number/memory/instr.c

799 lines
25 KiB
C

/*
* Emulation of priviledged instructions
*
* Copyright 1995 Alexandre Julliard
*/
#include "windef.h"
#include "wingdi.h"
#include "wine/winuser16.h"
#include "ldt.h"
#include "global.h"
#include "module.h"
#include "miscemu.h"
#include "selectors.h"
#include "debugtools.h"
DEFAULT_DEBUG_CHANNEL(int);
DECLARE_DEBUG_CHANNEL(io);
#ifdef __i386__
inline static void add_stack( CONTEXT86 *context, int offset )
{
if (ISV86(context) || !IS_SELECTOR_32BIT(context->SegSs))
ADD_LOWORD( context->Esp, offset );
else
context->Esp += offset;
}
inline static void *make_ptr( CONTEXT86 *context, DWORD seg, DWORD off, int long_addr )
{
if (ISV86(context)) return PTR_REAL_TO_LIN( seg, off );
if (IS_SELECTOR_SYSTEM(seg)) return (void *)off;
if (!long_addr) off = LOWORD(off);
return PTR_SEG_OFF_TO_LIN( seg, off );
}
inline static void *get_stack( CONTEXT86 *context )
{
if (ISV86(context))
return PTR_REAL_TO_LIN( context->SegSs, context->Esp );
if (IS_SELECTOR_SYSTEM(context->SegSs))
return (void *)context->Esp;
if (IS_SELECTOR_32BIT(context->SegSs))
return PTR_SEG_OFF_TO_LIN( context->SegSs, context->Esp );
return PTR_SEG_OFF_TO_LIN( context->SegSs, LOWORD(context->Esp) );
}
/***********************************************************************
* INSTR_ReplaceSelector
*
* Try to replace an invalid selector by a valid one.
* The only selector where it is allowed to do "mov ax,40;mov es,ax"
* is the so called 'bimodal' selector 0x40, which points to the BIOS
* data segment. Used by (at least) Borland products (and programs compiled
* using Borland products).
*
* See Undocumented Windows, Chapter 5, __0040.
*/
static BOOL INSTR_ReplaceSelector( CONTEXT86 *context, WORD *sel )
{
extern char Call16_Start, Call16_End;
if (IS_SELECTOR_SYSTEM(context->SegCs))
if ( (char *)context->Eip >= &Call16_Start
&& (char *)context->Eip < &Call16_End )
{
/* Saved selector may have become invalid when the relay code */
/* tries to restore it. We simply clear it. */
*sel = 0;
return TRUE;
}
if (*sel == 0x40)
{
static WORD sys_timer = 0;
if (!sys_timer)
sys_timer = CreateSystemTimer( 55, DOSMEM_Tick );
*sel = DOSMEM_BiosDataSeg;
return TRUE;
}
if (!IS_SELECTOR_SYSTEM(*sel) && !IS_SELECTOR_FREE(*sel))
ERR("Got protection fault on valid selector, maybe your kernel is too old?\n" );
return FALSE; /* Can't replace selector, crashdump */
}
/***********************************************************************
* INSTR_GetOperandAddr
*
* Return the address of an instruction operand (from the mod/rm byte).
*/
static BYTE *INSTR_GetOperandAddr( CONTEXT86 *context, BYTE *instr,
int long_addr, int segprefix, int *len )
{
int mod, rm, base, index = 0, ss = 0, seg = 0, off;
#define GET_VAL(val,type) \
{ *val = *(type *)instr; instr += sizeof(type); *len += sizeof(type); }
*len = 0;
GET_VAL( &mod, BYTE );
rm = mod & 7;
mod >>= 6;
if (mod == 3)
{
switch(rm)
{
case 0: return (BYTE *)&context->Eax;
case 1: return (BYTE *)&context->Ecx;
case 2: return (BYTE *)&context->Edx;
case 3: return (BYTE *)&context->Ebx;
case 4: return (BYTE *)&context->Esp;
case 5: return (BYTE *)&context->Ebp;
case 6: return (BYTE *)&context->Esi;
case 7: return (BYTE *)&context->Edi;
}
}
if (long_addr)
{
if (rm == 4)
{
BYTE sib;
GET_VAL( &sib, BYTE );
rm = sib & 7;
ss = sib >> 6;
switch(sib >> 3)
{
case 0: index = context->Eax; break;
case 1: index = context->Ecx; break;
case 2: index = context->Edx; break;
case 3: index = context->Ebx; break;
case 4: index = 0; break;
case 5: index = context->Ebp; break;
case 6: index = context->Esi; break;
case 7: index = context->Edi; break;
}
}
switch(rm)
{
case 0: base = context->Eax; seg = context->SegDs; break;
case 1: base = context->Ecx; seg = context->SegDs; break;
case 2: base = context->Edx; seg = context->SegDs; break;
case 3: base = context->Ebx; seg = context->SegDs; break;
case 4: base = context->Esp; seg = context->SegSs; break;
case 5: base = context->Ebp; seg = context->SegSs; break;
case 6: base = context->Esi; seg = context->SegDs; break;
case 7: base = context->Edi; seg = context->SegDs; break;
}
switch (mod)
{
case 0:
if (rm == 5) /* special case: ds:(disp32) */
{
GET_VAL( &base, DWORD );
seg = context->SegDs;
}
break;
case 1: /* 8-bit disp */
GET_VAL( &off, BYTE );
base += (signed char)off;
break;
case 2: /* 32-bit disp */
GET_VAL( &off, DWORD );
base += (signed long)off;
break;
}
}
else /* short address */
{
switch(rm)
{
case 0: /* ds:(bx,si) */
base = LOWORD(context->Ebx) + LOWORD(context->Esi);
seg = context->SegDs;
break;
case 1: /* ds:(bx,di) */
base = LOWORD(context->Ebx) + LOWORD(context->Edi);
seg = context->SegDs;
break;
case 2: /* ss:(bp,si) */
base = LOWORD(context->Ebp) + LOWORD(context->Esi);
seg = context->SegSs;
break;
case 3: /* ss:(bp,di) */
base = LOWORD(context->Ebp) + LOWORD(context->Edi);
seg = context->SegSs;
break;
case 4: /* ds:(si) */
base = LOWORD(context->Esi);
seg = context->SegDs;
break;
case 5: /* ds:(di) */
base = LOWORD(context->Edi);
seg = context->SegDs;
break;
case 6: /* ss:(bp) */
base = LOWORD(context->Ebp);
seg = context->SegSs;
break;
case 7: /* ds:(bx) */
base = LOWORD(context->Ebx);
seg = context->SegDs;
break;
}
switch(mod)
{
case 0:
if (rm == 6) /* special case: ds:(disp16) */
{
GET_VAL( &base, WORD );
seg = context->SegDs;
}
break;
case 1: /* 8-bit disp */
GET_VAL( &off, BYTE );
base += (signed char)off;
break;
case 2: /* 16-bit disp */
GET_VAL( &off, WORD );
base += (signed short)off;
break;
}
base &= 0xffff;
}
if (segprefix != -1) seg = segprefix;
/* Make sure the segment and offset are valid */
if (IS_SELECTOR_SYSTEM(seg)) return (BYTE *)(base + (index << ss));
if (((seg & 7) != 7) || IS_SELECTOR_FREE(seg)) return NULL;
if (GET_SEL_LIMIT(seg) < (base + (index << ss))) return NULL;
return (BYTE *)PTR_SEG_OFF_TO_LIN( seg, (base + (index << ss)) );
#undef GET_VAL
}
/***********************************************************************
* INSTR_EmulateLDS
*
* Emulate the LDS (and LES,LFS,etc.) instruction.
*/
static BOOL INSTR_EmulateLDS( CONTEXT86 *context, BYTE *instr, int long_op,
int long_addr, int segprefix, int *len )
{
WORD seg;
BYTE *regmodrm = instr + 1 + (*instr == 0x0f);
BYTE *addr = INSTR_GetOperandAddr( context, regmodrm,
long_addr, segprefix, len );
if (!addr)
return FALSE; /* Unable to emulate it */
seg = *(WORD *)(addr + (long_op ? 4 : 2));
if (!INSTR_ReplaceSelector( context, &seg ))
return FALSE; /* Unable to emulate it */
/* Now store the offset in the correct register */
switch((*regmodrm >> 3) & 7)
{
case 0:
if (long_op) context->Eax = *(DWORD *)addr;
else SET_LOWORD(context->Eax,*(WORD *)addr);
break;
case 1:
if (long_op) context->Ecx = *(DWORD *)addr;
else SET_LOWORD(context->Ecx,*(WORD *)addr);
break;
case 2:
if (long_op) context->Edx = *(DWORD *)addr;
else SET_LOWORD(context->Edx,*(WORD *)addr);
break;
case 3:
if (long_op) context->Ebx = *(DWORD *)addr;
else SET_LOWORD(context->Ebx,*(WORD *)addr);
break;
case 4:
if (long_op) context->Esp = *(DWORD *)addr;
else SET_LOWORD(context->Esp,*(WORD *)addr);
break;
case 5:
if (long_op) context->Ebp = *(DWORD *)addr;
else SET_LOWORD(context->Ebp,*(WORD *)addr);
break;
case 6:
if (long_op) context->Esi = *(DWORD *)addr;
else SET_LOWORD(context->Esi,*(WORD *)addr);
break;
case 7:
if (long_op) context->Edi = *(DWORD *)addr;
else SET_LOWORD(context->Edi,*(WORD *)addr);
break;
}
/* Store the correct segment in the segment register */
switch(*instr)
{
case 0xc4: context->SegEs = seg; break; /* les */
case 0xc5: context->SegDs = seg; break; /* lds */
case 0x0f: switch(instr[1])
{
case 0xb2: context->SegSs = seg; break; /* lss */
case 0xb4: context->SegFs = seg; break; /* lfs */
case 0xb5: context->SegGs = seg; break; /* lgs */
}
break;
}
/* Add the opcode size to the total length */
*len += 1 + (*instr == 0x0f);
return TRUE;
}
/***********************************************************************
* INSTR_inport
*
* input on a I/O port
*/
static DWORD INSTR_inport( WORD port, int size, CONTEXT86 *context )
{
DWORD res = IO_inport( port, size );
if (TRACE_ON(io))
{
switch(size)
{
case 1:
DPRINTF( "0x%x < %02x @ %04x:%04x\n", port, LOBYTE(res),
(WORD)context->SegCs, LOWORD(context->Eip));
break;
case 2:
DPRINTF( "0x%x < %04x @ %04x:%04x\n", port, LOWORD(res),
(WORD)context->SegCs, LOWORD(context->Eip));
break;
case 4:
DPRINTF( "0x%x < %08lx @ %04x:%04x\n", port, res,
(WORD)context->SegCs, LOWORD(context->Eip));
break;
}
}
return res;
}
/***********************************************************************
* INSTR_outport
*
* output on a I/O port
*/
static void INSTR_outport( WORD port, int size, DWORD val, CONTEXT86 *context )
{
IO_outport( port, size, val );
if (TRACE_ON(io))
{
switch(size)
{
case 1:
DPRINTF("0x%x > %02x @ %04x:%04x\n", port, LOBYTE(val),
(WORD)context->SegCs, LOWORD(context->Eip));
break;
case 2:
DPRINTF("0x%x > %04x @ %04x:%04x\n", port, LOWORD(val),
(WORD)context->SegCs, LOWORD(context->Eip));
break;
case 4:
DPRINTF("0x%x > %08lx @ %04x:%04x\n", port, val,
(WORD)context->SegCs, LOWORD(context->Eip));
break;
}
}
}
/***********************************************************************
* INSTR_EmulateInstruction
*
* Emulate a priviledged instruction. Returns TRUE if emulation successful.
*/
BOOL INSTR_EmulateInstruction( CONTEXT86 *context )
{
int prefix, segprefix, prefixlen, len, repX, long_op, long_addr;
SEGPTR gpHandler;
BYTE *instr;
long_op = long_addr = (!ISV86(context) && IS_SELECTOR_32BIT(context->SegCs));
instr = make_ptr( context, context->SegCs, context->Eip, TRUE );
if (!instr) return FALSE;
/* First handle any possible prefix */
segprefix = -1; /* no prefix */
prefix = 1;
repX = 0;
prefixlen = 0;
while(prefix)
{
switch(*instr)
{
case 0x2e:
segprefix = context->SegCs;
break;
case 0x36:
segprefix = context->SegSs;
break;
case 0x3e:
segprefix = context->SegDs;
break;
case 0x26:
segprefix = context->SegEs;
break;
case 0x64:
segprefix = context->SegFs;
break;
case 0x65:
segprefix = context->SegGs;
break;
case 0x66:
long_op = !long_op; /* opcode size prefix */
break;
case 0x67:
long_addr = !long_addr; /* addr size prefix */
break;
case 0xf0: /* lock */
break;
case 0xf2: /* repne */
repX = 1;
break;
case 0xf3: /* repe */
repX = 2;
break;
default:
prefix = 0; /* no more prefixes */
break;
}
if (prefix)
{
instr++;
prefixlen++;
}
}
/* Now look at the actual instruction */
switch(*instr)
{
case 0x07: /* pop es */
case 0x17: /* pop ss */
case 0x1f: /* pop ds */
{
WORD seg = *(WORD *)get_stack( context );
if (INSTR_ReplaceSelector( context, &seg ))
{
switch(*instr)
{
case 0x07: context->SegEs = seg; break;
case 0x17: context->SegSs = seg; break;
case 0x1f: context->SegDs = seg; break;
}
add_stack(context, long_op ? 4 : 2);
context->Eip += prefixlen + 1;
return TRUE;
}
}
break; /* Unable to emulate it */
case 0x0f: /* extended instruction */
switch(instr[1])
{
case 0x22: /* mov eax, crX */
switch (instr[2]) {
case 0xc0:
ERR("mov eax,cr0 at 0x%08lx, EAX=0x%08lx\n",
context->Eip,context->Eax );
context->Eip += prefixlen+3;
return TRUE;
default:
break; /*fallthrough to bad instruction handling */
}
break; /*fallthrough to bad instruction handling */
case 0x20: /* mov crX, eax */
switch (instr[2]) {
case 0xe0: /* mov cr4, eax */
/* CR4 register . See linux/arch/i386/mm/init.c, X86_CR4_ defs
* bit 0: VME Virtual Mode Exception ?
* bit 1: PVI Protected mode Virtual Interrupt
* bit 2: TSD Timestamp disable
* bit 3: DE Debugging extensions
* bit 4: PSE Page size extensions
* bit 5: PAE Physical address extension
* bit 6: MCE Machine check enable
* bit 7: PGE Enable global pages
* bit 8: PCE Enable performance counters at IPL3
*/
ERR("mov cr4,eax at 0x%08lx\n",context->Eip);
context->Eax = 0;
context->Eip += prefixlen+3;
return TRUE;
case 0xc0: /* mov cr0, eax */
ERR("mov cr0,eax at 0x%08lx\n",context->Eip);
context->Eax = 0x10; /* FIXME: set more bits ? */
context->Eip += prefixlen+3;
return TRUE;
default: /* fallthrough to illegal instruction */
break;
}
/* fallthrough to illegal instruction */
break;
case 0xa1: /* pop fs */
{
WORD seg = *(WORD *)get_stack( context );
if (INSTR_ReplaceSelector( context, &seg ))
{
context->SegFs = seg;
add_stack(context, long_op ? 4 : 2);
context->Eip += prefixlen + 2;
return TRUE;
}
}
break;
case 0xa9: /* pop gs */
{
WORD seg = *(WORD *)get_stack( context );
if (INSTR_ReplaceSelector( context, &seg ))
{
context->SegGs = seg;
add_stack(context, long_op ? 4 : 2);
context->Eip += prefixlen + 2;
return TRUE;
}
}
break;
case 0xb2: /* lss addr,reg */
case 0xb4: /* lfs addr,reg */
case 0xb5: /* lgs addr,reg */
if (INSTR_EmulateLDS( context, instr, long_op,
long_addr, segprefix, &len ))
{
context->Eip += prefixlen + len;
return TRUE;
}
break;
}
break; /* Unable to emulate it */
case 0x6c: /* insb */
case 0x6d: /* insw/d */
case 0x6e: /* outsb */
case 0x6f: /* outsw/d */
{
int typ = *instr; /* Just in case it's overwritten. */
int outp = (typ >= 0x6e);
unsigned long count = repX ?
(long_addr ? context->Ecx : LOWORD(context->Ecx)) : 1;
int opsize = (typ & 1) ? (long_op ? 4 : 2) : 1;
int step = (context->EFlags & 0x400) ? -opsize : +opsize;
int seg = outp ? context->SegDs : context->SegEs; /* FIXME: is this right? */
if (outp)
/* FIXME: Check segment readable. */
(void)0;
else
/* FIXME: Check segment writeable. */
(void)0;
if (repX)
{
if (long_addr) context->Ecx = 0;
else SET_LOWORD(context->Ecx,0);
}
while (count-- > 0)
{
void *data;
WORD dx = LOWORD(context->Edx);
if (outp)
{
data = make_ptr( context, seg, context->Esi, long_addr );
if (long_addr) context->Esi += step;
else ADD_LOWORD(context->Esi,step);
}
else
{
data = make_ptr( context, seg, context->Edi, long_addr );
if (long_addr) context->Edi += step;
else ADD_LOWORD(context->Edi,step);
}
switch (typ)
{
case 0x6c:
*(BYTE *)data = INSTR_inport( dx, 1, context );
break;
case 0x6d:
if (long_op)
*(DWORD *)data = INSTR_inport( dx, 4, context );
else
*(WORD *)data = INSTR_inport( dx, 2, context );
break;
case 0x6e:
INSTR_outport( dx, 1, *(BYTE *)data, context );
break;
case 0x6f:
if (long_op)
INSTR_outport( dx, 4, *(DWORD *)data, context );
else
INSTR_outport( dx, 2, *(WORD *)data, context );
break;
}
}
context->Eip += prefixlen + 1;
}
return TRUE;
case 0x8e: /* mov XX,segment_reg */
{
WORD seg;
BYTE *addr = INSTR_GetOperandAddr(context, instr + 1,
long_addr, segprefix, &len );
if (!addr)
break; /* Unable to emulate it */
seg = *(WORD *)addr;
if (!INSTR_ReplaceSelector( context, &seg ))
break; /* Unable to emulate it */
switch((instr[1] >> 3) & 7)
{
case 0:
context->SegEs = seg;
context->Eip += prefixlen + len + 1;
return TRUE;
case 1: /* cs */
break;
case 2:
context->SegSs = seg;
context->Eip += prefixlen + len + 1;
return TRUE;
case 3:
context->SegDs = seg;
context->Eip += prefixlen + len + 1;
return TRUE;
case 4:
context->SegFs = seg;
context->Eip += prefixlen + len + 1;
return TRUE;
case 5:
context->SegGs = seg;
context->Eip += prefixlen + len + 1;
return TRUE;
case 6: /* unused */
case 7: /* unused */
break;
}
}
break; /* Unable to emulate it */
case 0xc4: /* les addr,reg */
case 0xc5: /* lds addr,reg */
if (INSTR_EmulateLDS( context, instr, long_op,
long_addr, segprefix, &len ))
{
context->Eip += prefixlen + len;
return TRUE;
}
break; /* Unable to emulate it */
case 0xcd: /* int <XX> */
if (long_op)
{
ERR("int xx from 32-bit code is not supported.\n");
break; /* Unable to emulate it */
}
else
{
FARPROC16 addr = INT_GetPMHandler( instr[1] );
WORD *stack = get_stack( context );
if (!addr)
{
FIXME("no handler for interrupt %02x, ignoring it\n", instr[1]);
context->Eip += prefixlen + 2;
return TRUE;
}
/* Push the flags and return address on the stack */
*(--stack) = LOWORD(context->EFlags);
*(--stack) = context->SegCs;
*(--stack) = LOWORD(context->Eip) + prefixlen + 2;
add_stack(context, -3 * sizeof(WORD));
/* Jump to the interrupt handler */
context->SegCs = HIWORD(addr);
context->Eip = LOWORD(addr);
}
return TRUE;
case 0xcf: /* iret */
if (long_op)
{
DWORD *stack = get_stack( context );
context->Eip = *stack++;
context->SegCs = *stack++;
context->EFlags = *stack;
add_stack(context, 3*sizeof(DWORD)); /* Pop the return address and flags */
}
else
{
WORD *stack = get_stack( context );
context->Eip = *stack++;
context->SegCs = *stack++;
SET_LOWORD(context->EFlags,*stack);
add_stack(context, 3*sizeof(WORD)); /* Pop the return address and flags */
}
return TRUE;
case 0xe4: /* inb al,XX */
SET_LOBYTE(context->Eax,INSTR_inport( instr[1], 1, context ));
context->Eip += prefixlen + 2;
return TRUE;
case 0xe5: /* in (e)ax,XX */
if (long_op)
context->Eax = INSTR_inport( instr[1], 4, context );
else
SET_LOWORD(context->Eax, INSTR_inport( instr[1], 2, context ));
context->Eip += prefixlen + 2;
return TRUE;
case 0xe6: /* outb XX,al */
INSTR_outport( instr[1], 1, LOBYTE(context->Eax), context );
context->Eip += prefixlen + 2;
return TRUE;
case 0xe7: /* out XX,(e)ax */
if (long_op)
INSTR_outport( instr[1], 4, context->Eax, context );
else
INSTR_outport( instr[1], 2, LOWORD(context->Eax), context );
context->Eip += prefixlen + 2;
return TRUE;
case 0xec: /* inb al,dx */
SET_LOBYTE(context->Eax, INSTR_inport( LOWORD(context->Edx), 1, context ) );
context->Eip += prefixlen + 1;
return TRUE;
case 0xed: /* in (e)ax,dx */
if (long_op)
context->Eax = INSTR_inport( LOWORD(context->Edx), 4, context );
else
SET_LOWORD(context->Eax, INSTR_inport( LOWORD(context->Edx), 2, context ));
context->Eip += prefixlen + 1;
return TRUE;
case 0xee: /* outb dx,al */
INSTR_outport( LOWORD(context->Edx), 1, LOBYTE(context->Eax), context );
context->Eip += prefixlen + 1;
return TRUE;
case 0xef: /* out dx,(e)ax */
if (long_op)
INSTR_outport( LOWORD(context->Edx), 4, context->Eax, context );
else
INSTR_outport( LOWORD(context->Edx), 2, LOWORD(context->Eax), context );
context->Eip += prefixlen + 1;
return TRUE;
case 0xfa: /* cli, ignored */
context->Eip += prefixlen + 1;
return TRUE;
case 0xfb: /* sti, ignored */
context->Eip += prefixlen + 1;
return TRUE;
}
/* Check for Win16 __GP handler */
gpHandler = HasGPHandler16( PTR_SEG_OFF_TO_SEGPTR( context->SegCs, context->Eip ) );
if (gpHandler)
{
WORD *stack = get_stack( context );
*--stack = context->SegCs;
*--stack = context->Eip;
add_stack(context, -2*sizeof(WORD));
context->SegCs = SELECTOROF( gpHandler );
context->Eip = OFFSETOF( gpHandler );
return TRUE;
}
return FALSE; /* Unable to emulate it */
}
#endif /* __i386__ */