virtual.c

一个实时的驱动支持库

/*
    This is a C++ run-time library for Windows kernel-mode drivers.
    Copyright (C) 2004 Bo Brant閚.
*/

/*
    The following is a modified subset of wine/dlls/kernel/virtual.c
    from version wine20040505.
*/

/*
 * Win32 virtual memory functions
 *
 * Copyright 1997 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <ntddk.h>

#if (VER_PRODUCTBUILD < 2195)
typedef ULONG ULONG_PTR;
#endif // (VER_PRODUCTBUILD < 2195)

/***********************************************************************
 *             IsBadReadPtr   (KERNEL32.@)
 *
 * RETURNS
 *	FALSE: Process has read access to entire block
 *   TRUE: Otherwise
 */
BOOLEAN
NTAPI
IsBadReadPtr(
    IN CONST PVOID  ptr,    /* [in] Address of memory block */
    IN ULONG_PTR    size    /* [in] Size of block */
    )
{
    if (!size) return FALSE;    /* handle 0 size case w/o reference */
    __try
    {
        volatile const char *p = ptr;
        char dummy;
        ULONG count = size;

        while (count > PAGE_SIZE)
        {
            dummy = *p;
            p += PAGE_SIZE;
            count -= PAGE_SIZE;
        }
        dummy = p[0];
        dummy = p[count - 1];
    }
    __except(EXCEPTION_EXECUTE_HANDLER) { return TRUE; }
    return FALSE;
}

/***********************************************************************
 *             IsBadWritePtr   (KERNEL32.@)
 *
 * RETURNS
 *	FALSE: Process has write access to entire block
 *   TRUE: Otherwise
 */
BOOLEAN
NTAPI
IsBadWritePtr(
    IN PVOID        ptr,    /* [in] Address of memory block */
    IN ULONG_PTR    size    /* [in] Size of block in bytes */
    )
{
    if (!size) return FALSE;    /* handle 0 size case w/o reference */
    __try
    {
        volatile char *p = ptr;
        ULONG count = size;

        while (count > PAGE_SIZE)
        {
            *p |= 0;
            p += PAGE_SIZE;
            count -= PAGE_SIZE;
        }
        p[0] |= 0;
        p[count - 1] |= 0;
    }
    __except(EXCEPTION_EXECUTE_HANDLER) { return TRUE; }
    return FALSE;
}

/***********************************************************************
 *             IsBadCodePtr   (KERNEL32.@)
 *
 * RETURNS
 *	FALSE: Process has read access to specified memory
 *	 TRUE: Otherwise
 */
BOOLEAN
NTAPI
IsBadCodePtr(
    IN int (NTAPI *ptr)(VOID)   /* [in] Address of function */
    )
{
    return IsBadReadPtr( ptr, 1 );
}