[tkreuzer] 62743: [NTOSKRNL] Simplify code in ExpLookupHandleTableEntry CORE-6843 #resolve
Author: tkreuzer Date: Sun Apr 13 16:45:58 2014 New Revision: 62743
URL: http://svn.reactos.org/svn/reactos?rev=62743&view=rev Log: [NTOSKRNL] Simplify code in ExpLookupHandleTableEntry CORE-6843 #resolve
Modified: trunk/reactos/ntoskrnl/ex/handle.c trunk/reactos/ntoskrnl/include/internal/ex.h
Modified: trunk/reactos/ntoskrnl/ex/handle.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ex/handle.c?rev=62... ============================================================================== --- trunk/reactos/ntoskrnl/ex/handle.c [iso-8859-1] (original) +++ trunk/reactos/ntoskrnl/ex/handle.c [iso-8859-1] Sun Apr 13 16:45:58 2014 @@ -34,90 +34,59 @@ PHANDLE_TABLE_ENTRY NTAPI ExpLookupHandleTableEntry(IN PHANDLE_TABLE HandleTable, - IN EXHANDLE LookupHandle) -{ - ULONG TableLevel, NextHandle; - ULONG_PTR i, j, k, TableBase; - PHANDLE_TABLE_ENTRY Entry = NULL; - EXHANDLE Handle = LookupHandle; - PUCHAR Level1, Level2, Level3; - - /* Clear the tag bits and check what the next handle is */ + IN EXHANDLE Handle) +{ + ULONG TableLevel; + ULONG_PTR TableBase; + PHANDLE_TABLE_ENTRY HandleArray, Entry; + PVOID *PointerArray; + + /* Clear the tag bits */ Handle.TagBits = 0; - NextHandle = *(volatile ULONG*)&HandleTable->NextHandleNeedingPool; - if (Handle.Value >= NextHandle) return NULL; + + /* Check if the handle is in the allocated range */ + if (Handle.Value >= HandleTable->NextHandleNeedingPool) + { + return NULL; + }
/* Get the table code */ - TableBase = *(volatile ULONG_PTR*)&HandleTable->TableCode; + TableBase = HandleTable->TableCode;
/* Extract the table level and actual table base */ TableLevel = (ULONG)(TableBase & 3); - TableBase = TableBase - TableLevel; + TableBase &= ~3; + + PointerArray = (PVOID*)TableBase; + HandleArray = (PHANDLE_TABLE_ENTRY)TableBase;
/* Check what level we're running at */ switch (TableLevel) { - /* Direct index */ + case 2: + + /* Get the mid level pointer array */ + PointerArray = PointerArray[Handle.HighIndex]; + + /* Fall through */ + case 1: + + /* Get the handle array */ + HandleArray = PointerArray[Handle.MidIndex]; + + /* Fall through */ case 0:
- /* Use level 1 and just get the entry directly */ - Level1 = (PUCHAR)TableBase; - Entry = (PVOID)&Level1[Handle.Value * - (sizeof(HANDLE_TABLE_ENTRY) / - SizeOfHandle(1))]; - break; - - /* Nested index into mid level */ - case 1: - - /* Get the second table and index into it */ - Level2 = (PUCHAR)TableBase; - i = Handle.Value % SizeOfHandle(LOW_LEVEL_ENTRIES); - - /* Substract this index, and get the next one */ - Handle.Value -= i; - j = Handle.Value / - (SizeOfHandle(LOW_LEVEL_ENTRIES) / sizeof(PHANDLE_TABLE_ENTRY)); - - /* Now get the next table and get the entry from it */ - Level1 = (PUCHAR)*(PHANDLE_TABLE_ENTRY*)&Level2[j]; - Entry = (PVOID)&Level1[i * - (sizeof(HANDLE_TABLE_ENTRY) / - SizeOfHandle(1))]; - break; - - /* Nested index into high level */ - case 2: - - /* Start with the 3rd level table */ - Level3 = (PUCHAR)TableBase; - i = Handle.Value % SizeOfHandle(LOW_LEVEL_ENTRIES); - - /* Subtract this index and get the index for the next lower table */ - Handle.Value -= i; - k = Handle.Value / - (SizeOfHandle(LOW_LEVEL_ENTRIES) / sizeof(PHANDLE_TABLE_ENTRY)); - - /* Get the remaining index in the 2nd level table */ - j = k % (MID_LEVEL_ENTRIES * sizeof(PHANDLE_TABLE_ENTRY)); - - /* Get the remaining index, which is in the third table */ - k -= j; - k /= MID_LEVEL_ENTRIES; - - /* Extract the table level for the handle in each table */ - Level2 = (PUCHAR)*(PHANDLE_TABLE_ENTRY*)&Level3[k]; - Level1 = (PUCHAR)*(PHANDLE_TABLE_ENTRY*)&Level2[j]; - - /* Get the handle table entry */ - Entry = (PVOID)&Level1[i * - (sizeof(HANDLE_TABLE_ENTRY) / - SizeOfHandle(1))]; - - default: + /* Get the entry using the low index */ + Entry = &HandleArray[Handle.LowIndex];
/* All done */ break; + + default: + + NT_ASSERT(FALSE); + Entry = NULL; }
/* Return the handle entry */ @@ -217,7 +186,7 @@ PAGED_CODE();
/* Check which level we're at */ - if (!TableLevel) + if (TableLevel == 0) { /* Select the first level table base and just free it */ Level1 = (PVOID)TableBase; @@ -504,7 +473,7 @@ PAGED_CODE();
/* Check how many levels we already have */ - if (!TableLevel) + if (TableLevel == 0) { /* Allocate a mid level, since we only have a low level */ Mid = ExpAllocateMidLevelTable(HandleTable, DoInit, &Low); @@ -599,6 +568,11 @@ Value = InterlockedExchangePointer((PVOID*)&ThirdLevel[i][j], Low); ASSERT(Value == NULL); } + } + else + { + /* Something is really broken */ + ASSERT(FALSE); }
/* Update the index of the next handle */
Modified: trunk/reactos/ntoskrnl/include/internal/ex.h URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/internal/e... ============================================================================== --- trunk/reactos/ntoskrnl/include/internal/ex.h [iso-8859-1] (original) +++ trunk/reactos/ntoskrnl/include/internal/ex.h [iso-8859-1] Sun Apr 13 16:45:58 2014 @@ -33,18 +33,32 @@ extern KSPIN_LOCK ExpNonPagedLookasideListLock; extern KSPIN_LOCK ExpPagedLookasideListLock;
-typedef struct _EXHANDLE -{ - union - { - struct - { - ULONG TagBits:2; - ULONG Index:30; - }; - HANDLE GenericHandleOverlay; - ULONG_PTR Value; - }; +#ifdef _WIN64 +#define HANDLE_LOW_BITS (PAGE_SHIFT - 4) +#define HANDLE_HIGH_BITS (PAGE_SHIFT - 3) +#else +#define HANDLE_LOW_BITS (PAGE_SHIFT - 3) +#define HANDLE_HIGH_BITS (PAGE_SHIFT - 2) +#endif +#define KERNEL_FLAG_BITS (sizeof(PVOID)*8 - 31) + +typedef union _EXHANDLE +{ + struct + { + ULONG_PTR TagBits:2; + ULONG_PTR Index:29; + }; + struct + { + ULONG_PTR TagBits2:2; + ULONG_PTR LowIndex:HANDLE_LOW_BITS; + ULONG_PTR MidIndex:HANDLE_HIGH_BITS; + ULONG_PTR HighIndex:HANDLE_HIGH_BITS; + ULONG_PTR KernelFlag:KERNEL_FLAG_BITS; + }; + HANDLE GenericHandleOverlay; + ULONG_PTR Value; } EXHANDLE, *PEXHANDLE;
typedef struct _ETIMER
-
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