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=62743&r1=62742&r2=62743&view=diff
==============================================================================
--- 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/ex.h?rev=62743&r1=62742&r2=62743&view=diff
==============================================================================
--- 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
