reactos/ntoskrnl/mm/dbgpool.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/mm/dbgpool.c
   5  * PURPOSE:         Debug version of a pool allocator
   6  * PROGRAMMERS:     Aleksey Bragin (aleksey@reactos.org)
   7  */
   8
   9 /* INCLUDES ***************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* FUNCTIONS **************************************************************/
  16
  17 typedef struct _EI_WHOLE_PAGE_HEADER {
  18     PVOID ActualAddress;
  19     ULONG Size;
  20     ULONG Tag;
  21 } EI_WHOLE_PAGE_HEADER, *PEI_WHOLE_PAGE_HEADER;
  22
  23 BOOLEAN
  24 NTAPI
  25 ExpIsPoolTagDebuggable(ULONG Tag)
  26 {
  27 #if 0
  28     if (Tag == 'llaC') return FALSE;
  29     if (Tag == 'virD') return FALSE;
  30     if (Tag == 'iveD') return FALSE;
  31     if (Tag == 'padA') return FALSE;
  32
  33     if (Tag == 'dSeS') return FALSE;
  34     if (Tag == 'iDbO') return FALSE;
  35     if (Tag == 'mNbO') return FALSE;
  36     if (Tag == 'DNbO') return FALSE;
  37     if (Tag == 'btbO') return FALSE;
  38     if (Tag == 'cSbO') return FALSE;
  39     //if (Tag == 'iSeS') return FALSE;
  40     //if (Tag == 'cAeS') return FALSE;
  41 #endif
  42
  43     return TRUE;
  44 }
  45
  46
  47 PVOID
  48 NTAPI
  49 ExpAllocateDebugPool(POOL_TYPE Type, ULONG Size, ULONG Tag, PVOID Caller, BOOLEAN EndOfPage)
  50 {
  51     ULONG UserSize, TotalSize, AlignedSize;
  52     ULONG_PTR UserData, GuardArea;
  53     PEI_WHOLE_PAGE_HEADER Header;
  54     ULONG_PTR Buffer;
  55
  56     /* Calculate sizes */
  57     AlignedSize = ROUND_UP(Size, MM_POOL_ALIGNMENT);
  58     UserSize = AlignedSize + sizeof(EI_WHOLE_PAGE_HEADER);
  59     TotalSize = UserSize + 2*PAGE_SIZE;
  60
  61     /* Right now we support only end-of-page allocations */
  62     ASSERT(EndOfPage);
  63
  64     /* Allocate space using default routine */
  65     if (Type & PAGED_POOL_MASK)
  66     {
  67         Buffer = (ULONG_PTR)
  68             ExAllocatePagedPoolWithTag(Type, TotalSize, Tag);
  69     }
  70     else
  71     {
  72         ASSERT(FALSE);
  73         return NULL;
  74     }
  75
  76
  77     /* If allocation failed - fail too */
  78     if (!Buffer)
  79     {
  80         DPRINT1("A big problem! Pool allocation failed!\n");
  81         return NULL;
  82     }
  83
  84     /* Calculate guard area as placed on a page boundary
  85      * at the end of allocated area */
  86     GuardArea = PAGE_ROUND_DOWN(Buffer + TotalSize - PAGE_SIZE + 1);
  87
  88     /* Calculate user data and header pointers */
  89     UserData = GuardArea - AlignedSize;
  90     Header = (PEI_WHOLE_PAGE_HEADER)(UserData - sizeof(EI_WHOLE_PAGE_HEADER));
  91
  92     /* Fill out the header */
  93     Header->ActualAddress = (PVOID)Buffer;
  94     Header->Tag = Tag;
  95     Header->Size = AlignedSize;
  96
  97     /* Protect the guard page */
  98     MmSetPageProtect(NULL, (PVOID)GuardArea, PAGE_NOACCESS);
  99
 100     DPRINT("Allocating whole page block Tag %c%c%c%c, Buffer %p, Header %p, UserData %p, GuardArea %p, Size %d\n",
 101         Tag & 0xFF, (Tag >> 8) & 0xFF,
 102         (Tag >> 16) & 0xFF, (Tag >> 24) & 0xFF,
 103         Buffer, Header, UserData, GuardArea, Size);
 104
 105     return (PVOID)UserData;
 106 }
 107
 108 VOID
 109 NTAPI
 110 ExpFreeDebugPool(PVOID Block, BOOLEAN PagedPool)
 111 {
 112     PEI_WHOLE_PAGE_HEADER Header;
 113     PVOID ProtectedPage;
 114
 115     /* Get pointer to our special header */
 116     Header = (PEI_WHOLE_PAGE_HEADER)
 117         (((PCHAR)Block) - sizeof(EI_WHOLE_PAGE_HEADER));
 118
 119     DPRINT("Freeing whole page block at %08x (Tag %c%c%c%c, %x Header %x)\n", Block,
 120         Header->Tag & 0xFF, (Header->Tag >> 8) & 0xFF,
 121         (Header->Tag >> 16) & 0xFF, (Header->Tag >> 24) & 0xFF, Header->Tag, Header);
 122
 123     /* Calculate protected page adresss */
 124     ProtectedPage = ((PCHAR)Block) + Header->Size;
 125
 126     /* Unprotect it */
 127     MmSetPageProtect(NULL, ProtectedPage, PAGE_READWRITE);
 128
 129     /* Free storage */
 130     ASSERT(PagedPool);
 131     ExFreePagedPool(Header->ActualAddress);
 132 }
 133
 134 /* EOF */