diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index e52a02daf..ff3d70400 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+2012-06-28  Corinna Vinschen  <corinna@vinschen.de>
+
+	* exceptions.cc (RtlUnwind): Align declaration with MSDN.
+	* ntdll.h: Define CreateDisposition Flags.  Add comments.
+	* winlean.h: Define FILE_SHARE_VALID_FLAGS if using Mingw64 headers.
+
 2012-06-27  Christopher Faylor  <me.cygwin2012@cgf.cx>
 
 	* cygwait.h (cancelable_wait): Make extern to avoid always including.
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 4c477e05d..4aa48c5ef 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -449,7 +449,7 @@ try_to_debug (bool waitloop)
   return dbg;
 }
 
-extern "C" DWORD __stdcall RtlUnwind (void *, void *, void *, DWORD);
+extern "C" void WINAPI RtlUnwind (void *, void *, PEXCEPTION_RECORD, void *);
 static void __stdcall rtl_unwind (exception_list *, PEXCEPTION_RECORD) __attribute__ ((noinline, regparm (3)));
 void __stdcall
 rtl_unwind (exception_list *frame, PEXCEPTION_RECORD e)
diff --git a/winsup/cygwin/ntdll.h b/winsup/cygwin/ntdll.h
index 2f63f41da..6a9122354 100644
--- a/winsup/cygwin/ntdll.h
+++ b/winsup/cygwin/ntdll.h
@@ -24,6 +24,15 @@
 #define NtCurrentThread()  ((HANDLE) 0xfffffffe)
 
 /* CreateDisposition in NtCreateFile call. */
+#define FILE_SUPERSEDE			0x00000000
+#define FILE_OPEN			0x00000001
+#define FILE_CREATE			0x00000002
+#define FILE_OPEN_IF			0x00000003
+#define FILE_OVERWRITE			0x00000004
+#define FILE_OVERWRITE_IF		0x00000005
+#define FILE_MAXIMUM_DISPOSITION	0x00000005
+
+/* Creation information returned in IO_STATUS_BLOCK. */
 #define FILE_SUPERSEDED     0
 #define FILE_OPENED         1
 #define FILE_CREATED        2
@@ -31,6 +40,28 @@
 #define FILE_EXISTS         4
 #define FILE_DOES_NOT_EXIST 5
 
+/* CreateFile/OpenFile options */
+#define FILE_DIRECTORY_FILE		0x00000001
+#define FILE_WRITE_THROUGH		0x00000002
+#define FILE_SEQUENTIAL_ONLY		0x00000004
+#define FILE_NO_INTERMEDIATE_BUFFERING	0x00000008
+#define FILE_SYNCHRONOUS_IO_ALERT	0x00000010
+#define FILE_SYNCHRONOUS_IO_NONALERT	0x00000020
+#define FILE_NON_DIRECTORY_FILE		0x00000040
+#define FILE_CREATE_TREE_CONNECTION	0x00000080
+#define FILE_COMPLETE_IF_OPLOCKED	0x00000100
+#define FILE_NO_EA_KNOWLEDGE		0x00000200
+#define FILE_OPEN_FOR_RECOVERY		0x00000400
+#define FILE_RANDOM_ACCESS		0x00000800
+#define FILE_DELETE_ON_CLOSE		0x00001000
+#define FILE_OPEN_BY_FILE_ID		0x00002000
+#define FILE_OPEN_FOR_BACKUP_INTENT	0x00004000
+#define FILE_NO_COMPRESSION		0x00008000
+#define FILE_RESERVE_OPFILTER		0x00100000
+#define FILE_OPEN_REPARSE_POINT		0x00200000
+#define FILE_OPEN_NO_RECALL		0x00400000
+#define FILE_OPEN_FOR_FREE_SPACE_QUERY	0x00800000
+
 /* Relative file position values in NtWriteFile call. */
 #define FILE_WRITE_TO_END_OF_FILE      (-1LL)
 #define FILE_USE_FILE_POINTER_POSITION (-2LL)
diff --git a/winsup/cygwin/winlean.h b/winsup/cygwin/winlean.h
index e5eeeb2ac..7d40b8321 100644
--- a/winsup/cygwin/winlean.h
+++ b/winsup/cygwin/winlean.h
@@ -37,4 +37,9 @@ details. */
    use this function.  Use GetSystemWindowsDirectoryW. */
 #define GetWindowsDirectoryW dont_use_GetWindowsDirectory
 #define GetWindowsDirectoryA dont_use_GetWindowsDirectory
+/* FILE_SHARE_VALID_FLAGS is a Mingw32 invention not backed by the system
+   headers.  Therefore it's not defined by Mingw64, either. */
+#ifdef __MINGW64_VERSION_MAJOR
+#define FILE_SHARE_VALID_FLAGS (FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE)
+#endif
 #endif /*_WINLEAN_H*/