Add ChangeLog entry for previous change and revert erroneously checked in

changes to dcrt0.cc and init.cc

1 files changed, 58 insertions, 2 deletions

diff --git a/winsup/cygwin/init.cc b/winsup/cygwin/init.cc
index b02b3cdfc..107d037f9 100644
--- a/winsup/cygwin/init.cc
+++ b/winsup/cygwin/init.cc
@@ -64,12 +64,58 @@ munge_threadfunc ()
     }
 }
 
+inline static void
+respawn_wow64_process ()
+{
+  NTSTATUS ret;
+  PROCESS_BASIC_INFORMATION pbi;
+  HANDLE parent;
+
+  ULONG wow64 = 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 (NtCurrentProcess (),
+				   ProcessBasicInformation,
+				   &pbi, sizeof pbi, NULL);
+  if (NT_SUCCESS (ret)
+      && (parent = OpenProcess (PROCESS_QUERY_INFORMATION,
+				FALSE,
+				pbi.InheritedFromUniqueProcessId)))
+    {
+      NtQueryInformationProcess (parent, ProcessWow64Information,
+				 &wow64, sizeof wow64, NULL);
+      CloseHandle (parent);
+    }
+
+  /* The parent is a real 64 bit process?  Respawn! */
+  if (!wow64)
+    {
+      PROCESS_INFORMATION pi;
+      STARTUPINFOW si;
+      DWORD ret = 0;
+
+      GetStartupInfoW (&si);
+      if (!CreateProcessW (NULL, GetCommandLineW (), NULL, NULL, TRUE,
+			   CREATE_DEFAULT_ERROR_MODE
+			   | GetPriorityClass (GetCurrentProcess ()),
+			   NULL, NULL, &si, &pi))
+	api_fatal ("Failed to create process <%s>, %E", GetCommandLineA ());
+      CloseHandle (pi.hThread);
+      if (WaitForSingleObject (pi.hProcess, INFINITE) == WAIT_FAILED)
+	api_fatal ("Waiting for process %d failed, %E", pi.dwProcessId);
+      GetExitCodeProcess (pi.hProcess, &ret);
+      CloseHandle (pi.hProcess);
+      ExitProcess (ret);
+    }
+}
+
 void dll_crt0_0 ();
 
 extern "C" BOOL WINAPI
 dll_entry (HANDLE h, DWORD reason, void *static_load)
 {
-  extern bool wow64_respawn;
+  BOOL wow64_test_stack_marker;
 
   switch (reason)
     {
@@ -80,6 +126,16 @@ dll_entry (HANDLE h, DWORD reason, void *static_load)
       cygwin_hmodule = (HMODULE) h;
       dynamically_loaded = (static_load == NULL);
 
+      /* Is the stack at an unusual address?  That is, an address which
+	 is in the usual space occupied by the process image, but below
+	 the auto load address of DLLs?
+	 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 (wincap.is_wow64 ()
+	  && &wow64_test_stack_marker >= (PBOOL) 0x400000
+	  && &wow64_test_stack_marker <= (PBOOL) 0x10000000)
+	respawn_wow64_process ();
+
       dll_crt0_0 ();
       _my_oldfunc = TlsAlloc ();
       dll_finished_loading = true;
@@ -94,7 +150,7 @@ dll_entry (HANDLE h, DWORD reason, void *static_load)
       break;
     case DLL_THREAD_DETACH:
       if (dll_finished_loading
-	  && !wow64_respawn
+	  && (PVOID) &_my_tls > (PVOID) &wow64_test_stack_marker
 	  && _my_tls.isinitialized ())
 	_my_tls.remove (0);
       /* Windows 2000 has a bug in NtTerminateThread.  Instead of releasing