reactos/subsystems/win32/win32k/eng/mem.c

   1 /*
   2  *  ReactOS W32 Subsystem
   3  *  Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19 /* $Id$
  20  *
  21  * COPYRIGHT:         See COPYING in the top level directory
  22  * PROJECT:           ReactOS kernel
  23  * PURPOSE:           GDI Driver Memory Management Functions
  24  * FILE:              subsys/win32k/eng/mem.c
  25  * PROGRAMER:         Jason Filby
  26  * REVISION HISTORY:
  27  *                 3/7/1999: Created
  28  */
  29
  30 #include <win32k.h>
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35 /*
  36  * @implemented
  37  */
  38 PVOID APIENTRY
  39 EngAllocMem(ULONG Flags,
  40             ULONG MemSize,
  41             ULONG Tag)
  42 {
  43   PVOID newMem;
  44
  45   newMem = ExAllocatePoolWithTag(PagedPool, MemSize, Tag);
  46
  47   if (Flags == FL_ZERO_MEMORY && NULL != newMem)
  48   {
  49     RtlZeroMemory(newMem, MemSize);
  50   }
  51
  52   return newMem;
  53 }
  54
  55 /*
  56  * @implemented
  57  */
  58 VOID APIENTRY
  59 EngFreeMem(PVOID Mem)
  60 {
  61   ExFreePool(Mem);
  62 }
  63
  64 /*
  65  * @implemented
  66  */
  67 PVOID APIENTRY
  68 EngAllocUserMem(SIZE_T cj, ULONG Tag)
  69 {
  70   PVOID NewMem = NULL;
  71   NTSTATUS Status;
  72   SIZE_T MemSize = cj;
  73
  74   Status = ZwAllocateVirtualMemory(NtCurrentProcess(), &NewMem, 0, &MemSize, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
  75
  76   if (! NT_SUCCESS(Status))
  77     {
  78       return NULL;
  79     }
  80
  81   /* TODO: Add allocation info to AVL tree (stored inside W32PROCESS structure) */
  82
  83   return NewMem;
  84 }
  85
  86 /*
  87  * @implemented
  88  */
  89 VOID APIENTRY
  90 EngFreeUserMem(PVOID pv)
  91 {
  92   PVOID BaseAddress = pv;
  93   SIZE_T MemSize = 0;
  94
  95   ZwFreeVirtualMemory(NtCurrentProcess(), &BaseAddress, &MemSize, MEM_RELEASE);
  96
  97   /* TODO: Remove allocation info from AVL tree */
  98 }
  99
 100
 101
 102 PVOID
 103 APIENTRY
 104 HackSecureVirtualMemory(
 105         IN PVOID Address,
 106         IN SIZE_T Size,
 107         IN ULONG ProbeMode,
 108         OUT PVOID *SafeAddress)
 109 {
 110         NTSTATUS Status = STATUS_SUCCESS;
 111         PMDL mdl;
 112         LOCK_OPERATION Operation;
 113
 114         if (ProbeMode == PAGE_READONLY) Operation = IoReadAccess;
 115         else if (ProbeMode == PAGE_READWRITE) Operation = IoModifyAccess;
 116         else return NULL;
 117
 118         mdl = IoAllocateMdl(Address, Size, FALSE, TRUE, NULL);
 119         if (mdl == NULL)
 120         {
 121                 return NULL;
 122         }
 123
 124         _SEH2_TRY
 125         {
 126                 MmProbeAndLockPages(mdl, UserMode, Operation);
 127         }
 128         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 129         {
 130                 Status = _SEH2_GetExceptionCode();
 131         }
 132         _SEH2_END
 133
 134         if (!NT_SUCCESS(Status))
 135         {
 136                 IoFreeMdl(mdl);
 137                 return NULL;
 138         }
 139
 140         *SafeAddress = MmGetSystemAddressForMdlSafe(mdl, NormalPagePriority);
 141
 142         if(!*SafeAddress)
 143         {
 144                 MmUnlockPages(mdl);
 145                 IoFreeMdl(mdl);
 146                 return NULL;
 147         }
 148
 149         return mdl;
 150 }
 151
 152 VOID
 153 APIENTRY
 154 HackUnsecureVirtualMemory(
 155         IN PVOID  SecureHandle)
 156 {
 157         PMDL mdl = (PMDL)SecureHandle;
 158
 159         MmUnlockPages(mdl);
 160         IoFreeMdl(mdl);
 161 }
 162
 163 /*
 164  * @implemented
 165  */
 166 HANDLE APIENTRY
 167 EngSecureMem(PVOID Address, ULONG Length)
 168 {
 169   return MmSecureVirtualMemory(Address, Length, PAGE_READWRITE);
 170 }
 171
 172 /*
 173  * @implemented
 174  */
 175 VOID APIENTRY
 176 EngUnsecureMem(HANDLE Mem)
 177 {
 178   MmUnsecureVirtualMemory((PVOID) Mem);
 179 }
 180
 181 /* EOF */