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