From ae8456bdf2bd8d7a9b3a5ef0b18169caa7548189 Mon Sep 17 00:00:00 2001
From: Christopher Faylor <me@cgf.cx>
Date: Mon, 9 Dec 2013 20:32:24 +0000
Subject: [PATCH] * globals.cc (hntdll): Define/declare. * exceptions.cc
 (inside_kernel): Don't call GetModuleFileName if we know we're in ntdll. *
 sigproc.cc (wait_sig): Initialize hntdll.

---
 winsup/cygwin/ChangeLog     | 7 +++++++
 winsup/cygwin/exceptions.cc | 3 +++
 winsup/cygwin/globals.cc    | 1 +
 winsup/cygwin/sigproc.cc    | 2 ++
 4 files changed, 13 insertions(+)

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 90bc5cd3d..d479db262 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,10 @@
+2013-12-09  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
+	* globals.cc (hntdll): Define/declare.
+	* exceptions.cc (inside_kernel): Don't call GetModuleFileName if we
+	know we're in ntdll.
+	* sigproc.cc (wait_sig): Initialize hntdll.
+
 2013-12-09  Corinna Vinschen  <corinna@vinschen.de>
 
 	* include/cygwin/stdlib.h (initstate, random, setstate, srandom):
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index c0fb0c877..98eb78760 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -394,6 +394,9 @@ _cygtls::inside_kernel (CONTEXT *cx)
 # define h ((HMODULE) m.AllocationBase)
   if (!h || m.State != MEM_COMMIT)	/* Be defensive */
     res = true;
+  else if (h == hntdll)
+    res = true;				/* Calling GetModuleFilename on ntdll.dll
+					   can hang */
   else if (h == user_data->hmodule)
     res = false;
   else if (!GetModuleFileNameW (h, checkdir, windows_system_directory_length + 6))
diff --git a/winsup/cygwin/globals.cc b/winsup/cygwin/globals.cc
index 531703a7a..a004276d7 100644
--- a/winsup/cygwin/globals.cc
+++ b/winsup/cygwin/globals.cc
@@ -23,6 +23,7 @@ HANDLE NO_COPY hProcToken;
 HANDLE NO_COPY hProcImpToken;
 HANDLE my_wr_proc_pipe;
 HMODULE NO_COPY cygwin_hmodule;
+HMODULE NO_COPY hntdll;
 int NO_COPY sigExeced;
 WCHAR windows_system_directory[MAX_PATH];
 UINT windows_system_directory_length;
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index a2a2edd33..906dc6a35 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -1205,6 +1205,8 @@ wait_sig (VOID *)
   sigproc_printf ("entering ReadFile loop, my_readsig %p, my_sendsig %p",
 		  my_readsig, my_sendsig);
 
+  hntdll = GetModuleHandle ("ntdll.dll");
+
   for (;;)
     {
       DWORD nb;