Sweden-Number/memory/selector.c

480 lines
14 KiB
C

/*
* Selector manipulation functions
*
* Copyright 1995 Alexandre Julliard
*/
#include <string.h>
#include "windows.h"
#include "ldt.h"
#include "selectors.h"
#include "stackframe.h"
#include "stddebug.h"
#include "debug.h"
#define FIRST_LDT_ENTRY_TO_ALLOC 6
/***********************************************************************
* AllocSelectorArray (KERNEL.206)
*/
WORD AllocSelectorArray( WORD count )
{
WORD i, size = 0;
if (!count) return 0;
for (i = FIRST_LDT_ENTRY_TO_ALLOC; i < LDT_SIZE; i++)
{
if (!IS_LDT_ENTRY_FREE(i)) size = 0;
else if (++size >= count) break;
}
if (i == LDT_SIZE) return 0;
/* Mark selector as allocated */
while (size--) ldt_flags_copy[i--] |= LDT_FLAGS_ALLOCATED;
return ENTRY_TO_SELECTOR( i + 1 );
}
/***********************************************************************
* AllocSelector (KERNEL.175)
*/
WORD AllocSelector( WORD sel )
{
WORD newsel, count, i;
count = sel ? ((GET_SEL_LIMIT(sel) >> 16) + 1) : 1;
newsel = AllocSelectorArray( count );
dprintf_selector( stddeb, "AllocSelector(%04x): returning %04x\n",
sel, newsel );
if (!newsel) return 0;
if (!sel) return newsel; /* nothing to copy */
for (i = 0; i < count; i++)
{
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel) + i, &entry );
LDT_SetEntry( SELECTOR_TO_ENTRY(newsel) + i, &entry );
}
return newsel;
}
/***********************************************************************
* FreeSelector (KERNEL.176)
*/
WORD FreeSelector( WORD sel )
{
if (IS_SELECTOR_FREE(sel)) return sel; /* error */
SELECTOR_FreeBlock( sel, 1 );
return 0;
}
/***********************************************************************
* SELECTOR_SetEntries
*
* Set the LDT entries for an array of selectors.
*/
static void SELECTOR_SetEntries( WORD sel, const void *base, DWORD size,
enum seg_type type, BOOL32 is32bit,
BOOL32 readonly )
{
ldt_entry entry;
WORD i, count;
/* The limit for the first selector is the whole */
/* block. The next selectors get a 64k limit. */
entry.base = (unsigned long)base;
entry.type = type;
entry.seg_32bit = is32bit;
entry.read_only = readonly;
entry.limit_in_pages = (size > 0x100000);
if (entry.limit_in_pages) entry.limit = ((size + 0xfff) >> 12) - 1;
else entry.limit = size - 1;
/* Make sure base and limit are not 0 together if the size is not 0 */
if (!base && !entry.limit && size) entry.limit = 1;
count = (size + 0xffff) / 0x10000;
for (i = 0; i < count; i++)
{
LDT_SetEntry( SELECTOR_TO_ENTRY(sel) + i, &entry );
entry.base += 0x10000;
/* Apparently the next selectors should *not* get a 64k limit. */
/* Can't remember where I read they should... --AJ */
entry.limit -= entry.limit_in_pages ? 0x10 : 0x10000;
}
}
/***********************************************************************
* SELECTOR_AllocBlock
*
* Allocate selectors for a block of linear memory.
*/
WORD SELECTOR_AllocBlock( const void *base, DWORD size, enum seg_type type,
BOOL32 is32bit, BOOL32 readonly )
{
WORD sel, count;
if (!size) return 0;
count = (size + 0xffff) / 0x10000;
sel = AllocSelectorArray( count );
if (sel) SELECTOR_SetEntries( sel, base, size, type, is32bit, readonly );
return sel;
}
/***********************************************************************
* SELECTOR_FreeBlock
*
* Free a block of selectors.
*/
void SELECTOR_FreeBlock( WORD sel, WORD count )
{
WORD i, nextsel;
ldt_entry entry;
STACK16FRAME *frame;
dprintf_selector( stddeb, "SELECTOR_FreeBlock(%04x,%d)\n", sel, count );
sel &= ~(__AHINCR - 1); /* clear bottom bits of selector */
nextsel = sel + (count << __AHSHIFT);
memset( &entry, 0, sizeof(entry) ); /* clear the LDT entries */
for (i = SELECTOR_TO_ENTRY(sel); count; i++, count--)
{
LDT_SetEntry( i, &entry );
ldt_flags_copy[i] &= ~LDT_FLAGS_ALLOCATED;
}
/* Clear the saved 16-bit selector */
frame = CURRENT_STACK16;
while (frame)
{
if ((frame->ds >= sel) && (frame->ds < nextsel)) frame->ds = 0;
if ((frame->es >= sel) && (frame->es < nextsel)) frame->es = 0;
frame = PTR_SEG_OFF_TO_LIN(frame->saved_ss, frame->saved_sp);
}
}
/***********************************************************************
* SELECTOR_ReallocBlock
*
* Change the size of a block of selectors.
*/
WORD SELECTOR_ReallocBlock( WORD sel, const void *base, DWORD size,
enum seg_type type, BOOL32 is32bit, BOOL32 readonly)
{
WORD i, oldcount, newcount;
if (!size) size = 1;
oldcount = (GET_SEL_LIMIT(sel) >> 16) + 1;
newcount = (size + 0xffff) >> 16;
if (oldcount < newcount) /* We need to add selectors */
{
/* Check if the next selectors are free */
if (SELECTOR_TO_ENTRY(sel) + newcount > LDT_SIZE) i = oldcount;
else
for (i = oldcount; i < newcount; i++)
if (!IS_LDT_ENTRY_FREE(SELECTOR_TO_ENTRY(sel)+i)) break;
if (i < newcount) /* they are not free */
{
SELECTOR_FreeBlock( sel, oldcount );
sel = AllocSelectorArray( newcount );
}
else /* mark the selectors as allocated */
{
for (i = oldcount; i < newcount; i++)
ldt_flags_copy[SELECTOR_TO_ENTRY(sel)+i] |=LDT_FLAGS_ALLOCATED;
}
}
else if (oldcount > newcount) /* We need to remove selectors */
{
SELECTOR_FreeBlock( ENTRY_TO_SELECTOR(SELECTOR_TO_ENTRY(sel)+newcount),
oldcount - newcount );
}
if (sel) SELECTOR_SetEntries( sel, base, size, type, is32bit, readonly );
return sel;
}
/***********************************************************************
* PrestoChangoSelector (KERNEL.177)
*/
WORD PrestoChangoSelector( WORD selSrc, WORD selDst )
{
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY( selSrc ), &entry );
entry.type ^= SEGMENT_CODE; /* toggle the executable bit */
LDT_SetEntry( SELECTOR_TO_ENTRY( selDst ), &entry );
return selDst;
}
/***********************************************************************
* AllocCStoDSAlias (KERNEL.170)
*/
WORD AllocCStoDSAlias( WORD sel )
{
WORD newsel;
ldt_entry entry;
newsel = AllocSelectorArray( 1 );
dprintf_selector( stddeb, "AllocCStoDSAlias(%04x): returning %04x\n",
sel, newsel );
if (!newsel) return 0;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
entry.type = SEGMENT_DATA;
LDT_SetEntry( SELECTOR_TO_ENTRY(newsel), &entry );
return newsel;
}
/***********************************************************************
* AllocDStoCSAlias (KERNEL.171)
*/
WORD AllocDStoCSAlias( WORD sel )
{
WORD newsel;
ldt_entry entry;
newsel = AllocSelectorArray( 1 );
dprintf_selector( stddeb, "AllocDStoCSAlias(%04x): returning %04x\n",
sel, newsel );
if (!newsel) return 0;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
entry.type = SEGMENT_CODE;
LDT_SetEntry( SELECTOR_TO_ENTRY(newsel), &entry );
return newsel;
}
/***********************************************************************
* LongPtrAdd (KERNEL.180)
*/
void LongPtrAdd( DWORD ptr, DWORD add )
{
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY(SELECTOROF(ptr)), &entry );
entry.base += add;
LDT_SetEntry( SELECTOR_TO_ENTRY(SELECTOROF(ptr)), &entry );
}
/***********************************************************************
* GetSelectorBase (KERNEL.186)
*/
DWORD GetSelectorBase( WORD sel )
{
extern char* DOSMEM_dosmem;
DWORD base;
base = GET_SEL_BASE(sel);
/* if base points into DOSMEM, assume we have to
* return pointer into physical lower 1MB
*/
if ((base >= (DWORD)DOSMEM_dosmem) &&
(base < (DWORD)DOSMEM_dosmem+0x100000)) base -= (DWORD)DOSMEM_dosmem;
return base;
}
/***********************************************************************
* SetSelectorBase (KERNEL.187)
*/
WORD SetSelectorBase( WORD sel, DWORD base )
{
extern char* DOSMEM_dosmem;
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
#ifndef WINELIB
if (base < 0x100000)
{
/* Assume pointers in the lower 1MB range are
* in fact physical addresses into DOS memory.
* Translate the base to our internal representation
*
* (NETAPI.DLL of Win95 does use SetSelectorBase this way)
*/
entry.base = (DWORD)(DOSMEM_dosmem+base);
}
else entry.base = base;
#endif
LDT_SetEntry( SELECTOR_TO_ENTRY(sel), &entry );
return sel;
}
/***********************************************************************
* GetSelectorLimit (KERNEL.188)
*/
DWORD GetSelectorLimit( WORD sel )
{
return GET_SEL_LIMIT(sel);
}
/***********************************************************************
* SetSelectorLimit (KERNEL.189)
*/
WORD SetSelectorLimit( WORD sel, DWORD limit )
{
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
entry.limit_in_pages = (limit >= 0x100000);
if (entry.limit_in_pages) entry.limit = limit >> 12;
else entry.limit = limit;
LDT_SetEntry( SELECTOR_TO_ENTRY(sel), &entry );
return sel;
}
/***********************************************************************
* SelectorAccessRights (KERNEL.196)
*/
WORD SelectorAccessRights( WORD sel, WORD op, WORD val )
{
ldt_entry entry;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
if (op == 0) /* get */
{
return 0x01 | /* accessed */
0x10 | /* not system */
0x60 | /* DPL 3 */
0x80 | /* present */
((entry.read_only == 0) << 1) |
(entry.type << 2) |
(entry.seg_32bit << 14) |
(entry.limit_in_pages << 15);
}
else /* set */
{
entry.read_only = ((val & 2) == 0);
entry.type = (val >> 2) & 3;
entry.seg_32bit = val & 0x4000;
entry.limit_in_pages = val & 0x8000;
LDT_SetEntry( SELECTOR_TO_ENTRY(sel), &entry );
return 0;
}
}
/***********************************************************************
* IsBadCodePtr16 (KERNEL.336)
*/
BOOL16 IsBadCodePtr16( SEGPTR lpfn )
{
WORD sel;
ldt_entry entry;
sel = SELECTOROF(lpfn);
if (!sel) return TRUE;
if (IS_SELECTOR_FREE(sel)) return TRUE;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
if (entry.type != SEGMENT_CODE) return TRUE;
if (OFFSETOF(lpfn) > entry.limit) return TRUE;
return FALSE;
}
/***********************************************************************
* IsBadStringPtr16 (KERNEL.337)
*/
BOOL16 IsBadStringPtr16( SEGPTR ptr, UINT16 size )
{
WORD sel;
ldt_entry entry;
sel = SELECTOROF(ptr);
if (!sel) return TRUE;
if (IS_SELECTOR_FREE(sel)) return TRUE;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
if ((entry.type == SEGMENT_CODE) && entry.read_only) return TRUE;
if (strlen(PTR_SEG_TO_LIN(ptr)) < size) size = strlen(PTR_SEG_TO_LIN(ptr));
if (OFFSETOF(ptr) + size - 1 > entry.limit) return TRUE;
return FALSE;
}
/***********************************************************************
* IsBadHugeReadPtr16 (KERNEL.346)
*/
BOOL16 IsBadHugeReadPtr16( SEGPTR ptr, DWORD size )
{
WORD sel;
ldt_entry entry;
sel = SELECTOROF(ptr);
if (!sel) return TRUE;
if (IS_SELECTOR_FREE(sel)) return TRUE;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
if ((entry.type == SEGMENT_CODE) && entry.read_only) return TRUE;
if (OFFSETOF(ptr) + size - 1 > entry.limit) return TRUE;
return FALSE;
}
/***********************************************************************
* IsBadHugeWritePtr16 (KERNEL.347)
*/
BOOL16 IsBadHugeWritePtr16( SEGPTR ptr, DWORD size )
{
WORD sel;
ldt_entry entry;
sel = SELECTOROF(ptr);
if (!sel) return TRUE;
if (IS_SELECTOR_FREE(sel)) return TRUE;
LDT_GetEntry( SELECTOR_TO_ENTRY(sel), &entry );
if ((entry.type == SEGMENT_CODE) || entry.read_only) return TRUE;
if (OFFSETOF(ptr) + size - 1 > entry.limit) return TRUE;
return FALSE;
}
/***********************************************************************
* IsBadReadPtr16 (KERNEL.334)
*/
BOOL16 IsBadReadPtr16( SEGPTR ptr, UINT16 size )
{
return IsBadHugeReadPtr16( ptr, size );
}
/***********************************************************************
* IsBadWritePtr16 (KERNEL.335)
*/
BOOL16 IsBadWritePtr16( SEGPTR ptr, UINT16 size )
{
return IsBadHugeWritePtr16( ptr, size );
}
/***********************************************************************
* MemoryRead (TOOLHELP.78)
*/
DWORD MemoryRead( WORD sel, DWORD offset, void *buffer, DWORD count )
{
if (IS_SELECTOR_FREE(sel)) return 0;
if (offset > GET_SEL_LIMIT(sel)) return 0;
if (offset + count > GET_SEL_LIMIT(sel) + 1)
count = GET_SEL_LIMIT(sel) + 1 - offset;
memcpy( buffer, ((char *)GET_SEL_BASE(sel)) + offset, count );
return count;
}
/***********************************************************************
* MemoryWrite (TOOLHELP.79)
*/
DWORD MemoryWrite( WORD sel, DWORD offset, void *buffer, DWORD count )
{
if (IS_SELECTOR_FREE(sel)) return 0;
if (offset > GET_SEL_LIMIT(sel)) return 0;
if (offset + count > GET_SEL_LIMIT(sel) + 1)
count = GET_SEL_LIMIT(sel) + 1 - offset;
memcpy( ((char *)GET_SEL_BASE(sel)) + offset, buffer, count );
return count;
}