* init.cc (respawn_wow64_process): Make inline function. Remove

"noreturn" attribute.  Add additional check if parent process is
	actually a 64 bit process.
	(dll_entry): Only test WOW64 processes with a stack in the usual
	"dangerous" process space area.

winsup/cygwin/ChangeLog

@@ -1,3 +1,11 @@
+2005-08-14  Corinna Vinschen  <corinna@vinschen.de>
+
+	* init.cc (respawn_wow64_process): Make inline function.  Remove
+	"noreturn" attribute.  Add additional check if parent process is
+	actually a 64 bit process.
+	(dll_entry): Only test WOW64 processes with a stack in the usual
+	"dangerous" process space area.
+
 2005-08-11  Troy Curtiss  <trcurtiss@gmail.com>
 
 	* fhandler_serial.cc (fhandler_serial::tcgetattr): Return current baud

winsup/cygwin/init.cc

@@ -15,6 +15,8 @@ details. */
 #include "perprocess.h"
 #include "cygtls.h"
 #include "pinfo.h"
+#include <ntdef.h>
+#include "ntdll.h"
 
 int NO_COPY dynamically_loaded;
 static char *search_for = (char *) cygthread::stub;
@@ -88,8 +90,32 @@ munge_threadfunc ()
     }
 }
 
-static void __attribute__ ((noreturn))
+inline static void
 respawn_wow64_process ()
+{
+  NTSTATUS ret;
+  PROCESS_BASIC_INFORMATION pbi;
+  HANDLE parent;
+
+  BOOL is_wow64_proc = TRUE;	/* Opt on the safe side. */
+
+  /* Unfortunately there's no simpler way to retrieve the
+     parent process in NT, as far as I know.  Hints welcome. */
+  ret = NtQueryInformationProcess (GetCurrentProcess (),
+				   ProcessBasicInformation,
+				   (PVOID) &pbi,
+				   sizeof pbi, NULL);
+  if (ret == STATUS_SUCCESS
+      && (parent = OpenProcess (PROCESS_QUERY_INFORMATION,
+				FALSE,
+				pbi.InheritedFromUniqueProcessId)))
+    {
+      IsWow64Process (parent, &is_wow64_proc);
+      CloseHandle (parent);
+    }
+
+  /* The parent is a real 64 bit process?  Respawn! */
+  if (!is_wow64_proc)
     {
       PROCESS_INFORMATION pi;
       STARTUPINFO si;
@@ -105,6 +131,7 @@ respawn_wow64_process ()
       CloseHandle (pi.hProcess);
       ExitProcess (0);
     }
+}
 
 extern void __stdcall dll_crt0_0 ();
 
@@ -113,18 +140,23 @@ HMODULE NO_COPY cygwin_hmodule;
 extern "C" int WINAPI
 dll_entry (HANDLE h, DWORD reason, void *static_load)
 {
-  BOOL is_64bit_machine = FALSE;
+  BOOL is_wow64_proc = FALSE;
 
   switch (reason)
     {
     case DLL_PROCESS_ATTACH:
       cygwin_hmodule = (HMODULE) h;
       dynamically_loaded = (static_load == NULL);
-      /* Is the stack at an unusual high address?  Check if we're running on
+
-	 a 64 bit machine.  If so, respawn. */
+      /* Is the stack at an unusual address?  This is, an address which
-      if (&is_64bit_machine >= (PBOOL) 0x400000
+         is in the usual space occupied by the process image, but below
-	  && IsWow64Process (hMainProc, &is_64bit_machine)
+	 the auto load address of DLLs?
-	  && is_64bit_machine)
+	 Check if we're running in WOW64 on a 64 bit machine *and* are
+	 spawned by a genuine 64 bit process.  If so, respawn. */
+      if (&is_wow64_proc >= (PBOOL) 0x400000
+          && &is_wow64_proc <= (PBOOL) 0x10000000
+          && IsWow64Process (hMainProc, &is_wow64_proc)
+	  && is_wow64_proc)
 	respawn_wow64_process ();
 
       prime_threads ();