[weiden] 17474: added a macro IsKernelPointer() to test whether a pointer value points to the kernel address space. This is needed because on IA-64 the MSB is not necessarily set for pointers to the kernel address space.

added a macro IsKernelPointer() to test whether a pointer value points
to the kernel address space. This is needed because on IA-64 the MSB is
not necessarily set for pointers to the kernel address space.
Modified: trunk/reactos/ntoskrnl/include/internal/ntoskrnl.h
Modified: trunk/reactos/ntoskrnl/ob/wait.c
  _____

Modified: trunk/reactos/ntoskrnl/include/internal/ntoskrnl.h
--- trunk/reactos/ntoskrnl/include/internal/ntoskrnl.h	2005-08-22
10:51:05 UTC (rev 17473)
+++ trunk/reactos/ntoskrnl/include/internal/ntoskrnl.h	2005-08-22
13:38:30 UTC (rev 17474)
@@ -147,8 +147,26 @@

#define ProbeForReadLargeInteger(Ptr)
((LARGE_INTEGER)ProbeForReadGenericType(&(Ptr)->QuadPart, LONGLONG, 0))
 #define ProbeForReadUlargeInteger(Ptr)
((ULARGE_INTEGER)ProbeForReadGenericType(&(Ptr)->QuadPart, ULONGLONG,
0))

+/*
+ * Use IsKernelPointer to test whether a pointer points to the kernel
address
+ * space
+ */
+#if defined(_X86_) || defined(_M_AMD64)

+/* for x86 and x86-64 the MSB is 1 so we can simply test on that */
+#define IsKernelPointer(Ptr) ((LONG_PTR)(Ptr) < 0)
+
+#elif defined(_IA64_)
+
+/* on Itanium if the 24 most significant bits are set, we're not
dealing with
+   user mode pointers. */
+#define IsKernelPointer(Ptr)  (((ULONG_PTR)(Ptr) &
0xFFFFFF0000000000ULL) != 0)
+
+#else
+#error IsKernelPointer() needs to be defined for this architecture
 #endif
+
+#endif
 /*
  *
  */
  _____

Modified: trunk/reactos/ntoskrnl/ob/wait.c
--- trunk/reactos/ntoskrnl/ob/wait.c	2005-08-22 10:51:05 UTC (rev
17473)
+++ trunk/reactos/ntoskrnl/ob/wait.c	2005-08-22 13:38:30 UTC (rev
17474)
@@ -149,7 +149,7 @@

DefaultObject = ObjectHeader->Type->DefaultObject;

/* Check if it's the internal offset */
-        if ((LONG_PTR)DefaultObject >= 0)
+        if (!IsKernelPointer(DefaultObject))
         {
             /* Increase reference count */
             InterlockedIncrement(&ObjectHeader->PointerCount);
@@ -295,7 +295,7 @@
         WaitableObject = BODY_TO_HEADER(Object)->Type->DefaultObject;

/* Is it an offset for internal objects? */
-        if ((LONG_PTR)WaitableObject >= 0)
+        if (!IsKernelPointer(WaitableObject))
         {
             /* Turn it into a pointer */
             WaitableObject = (PVOID)((ULONG_PTR)Object +
@@ -389,7 +389,7 @@
     WaitableObject = BODY_TO_HEADER(WaitObj)->Type->DefaultObject;

/* Handle internal offset */
-    if ((LONG_PTR)WaitableObject >= 0)
+    if (!IsKernelPointer(WaitableObject))
     {
         /* Get real pointer */
         WaitableObject = (PVOID)((ULONG_PTR)WaitObj +