diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index b22c3e40c..438de2dde 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,51 @@
+2010-01-14  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygwin.din (dup3): Export.
+	(pipe2): Export.
+	* dtable.cc (dtable::dup_worker): Take additional flags parameter.
+	Handle O_CLOEXEC flag.
+	(dtable::dup3): Rename from dup2.  Take additional flags parameter.
+	Check for valid flags.  Drop check for newfd == oldfd.
+	* dtable.h (dtable::dup_worker): Add flags parameter.
+	(dtable::dup3): Rename from dup2.
+	* fcntl.cc (fcntl64): Add F_DUPFD_CLOEXEC case.
+	* fhandler.h (fhandler_mailslot::get_object_attr): Add flags parameter.
+	* fhandler.cc (fhandler_base::open): Use security attribute with
+	inheritance according to setting of O_CLOEXEC flag.
+	* fhandler_console.cc (fhandler_console::open): Ditto.
+	* fhandler_fifo.cc (sec_user_cloexec): New inline function to
+	create security attribute with inheritance according to setting of
+	O_CLOEXEC flag.
+	(fhandler_fifo::open): Call sec_user_cloexec to fetch security
+	attribute.
+	(fhandler_fifo::wait): Ditto.
+	* fhandler_mem.cc (fhandler_dev_mem::open): Ditto.
+	* fhandler_mailslot.cc (fhandler_mailslot::get_object_attr): Take
+	additional flags parameter.  Use security attribute with inheritance
+	according to setting of O_CLOEXEC flag.
+	(fhandler_mailslot::open): Call get_object_attr with flags parameter.
+	* fhandler_registry.cc (fhandler_registry::open): Call set_close_on_exec
+	on real handles to accommodate O_CLOEXEC flag.
+	* fhandler_tty.cc (fhandler_tty_slave::open): Ditto.
+	* fhandler_tape.cc: Create mutex with inheritance according to setting
+	of O_CLOEXEC flag.
+	* pipe.cc: Replace usage of O_NOINHERIT with O_CLOEXEC.
+	 (fhandler_pipe::init): Simplify setting close_on_exec flag.
+	(fhandler_pipe::open): Remove setting close_on_exec flag.
+	(fhandler_pipe::create): Use security attribute with inheritance
+	according to setting of O_CLOEXEC flag.
+	(pipe2): New exported function.
+	* posix_ipc.cc: Throughout, open backing files with O_CLOEXEC
+	flag to follow POSIX semantics.
+	* security.h (sec_none_cloexec): New define.
+	* syscalls.cc (dup): Add missing extern "C" qualifier.  Accommodate
+	renaming of dtable::dup2 to dtable::dup3.
+	(dup2): Ditto.  Check newfd == oldfd here.
+	(dup3): New function.  Check newfd == oldfd here.
+	(open): Set close_on_exec flag according to O_CLOEXEC flag before
+	calling fhandler->open.
+	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
+
 2010-01-13  Corinna Vinschen  <corinna@vinschen.de>
 
 	* include/fcntl.h (O_TTY_INIT): Define as 0.
diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din
index 74c487946..ec485236c 100644
--- a/winsup/cygwin/cygwin.din
+++ b/winsup/cygwin/cygwin.din
@@ -297,6 +297,7 @@ dup SIGFE
 _dup = dup SIGFE
 dup2 SIGFE
 _dup2 = dup2 SIGFE
+dup3 SIGFE
 eaccess = euidaccess SIGFE
 ecvt SIGFE
 _ecvt = ecvt SIGFE
@@ -1071,6 +1072,7 @@ perror SIGFE
 _perror = perror SIGFE
 pipe SIGFE
 _pipe SIGFE
+pipe2 SIGFE
 poll SIGFE
 _poll = poll SIGFE
 popen SIGFE
diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
index ec5d3e386..f0738adc2 100644
--- a/winsup/cygwin/dtable.cc
+++ b/winsup/cygwin/dtable.cc
@@ -559,7 +559,7 @@ build_fh_pc (path_conv& pc, bool set_name)
 }
 
 fhandler_base *
-dtable::dup_worker (fhandler_base *oldfh)
+dtable::dup_worker (fhandler_base *oldfh, int flags)
 {
   /* Don't call set_name in build_fh_pc.  It will be called in
      fhandler_base::operator= below.  Calling it twice will result
@@ -579,7 +579,11 @@ dtable::dup_worker (fhandler_base *oldfh)
 	}
       else
 	{
-	  newfh->close_on_exec (false);
+	  /* The O_CLOEXEC flag enforces close-on-exec behaviour. */
+	  if (flags & O_CLOEXEC)
+	    newfh->set_close_on_exec (true);
+	  else
+	    newfh->close_on_exec (false);
 	  debug_printf ("duped '%s' old %p, new %p", oldfh->get_name (), oldfh->get_io_handle (), newfh->get_io_handle ());
 	}
     }
@@ -587,13 +591,13 @@ dtable::dup_worker (fhandler_base *oldfh)
 }
 
 int
-dtable::dup2 (int oldfd, int newfd)
+dtable::dup3 (int oldfd, int newfd, int flags)
 {
   int res = -1;
   fhandler_base *newfh = NULL;	// = NULL to avoid an incorrect warning
 
   MALLOC_CHECK;
-  debug_printf ("dup2 (%d, %d)", oldfd, newfd);
+  debug_printf ("dup3 (%d, %d, %p)", oldfd, newfd, flags);
   lock ();
 
   if (not_open (oldfd))
@@ -602,21 +606,20 @@ dtable::dup2 (int oldfd, int newfd)
       set_errno (EBADF);
       goto done;
     }
-
   if (newfd < 0)
     {
       syscall_printf ("new fd out of bounds: %d", newfd);
       set_errno (EBADF);
       goto done;
     }
-
-  if (newfd == oldfd)
+  if ((flags & ~O_CLOEXEC) != 0)
     {
-      res = newfd;
-      goto done;
+      syscall_printf ("invalid flags value %x", flags);
+      set_errno (EINVAL);
+      return -1;
     }
 
-  if ((newfh = dup_worker (fds[oldfd])) == NULL)
+  if ((newfh = dup_worker (fds[oldfd], flags)) == NULL)
     {
       res = -1;
       goto done;
@@ -644,7 +647,7 @@ dtable::dup2 (int oldfd, int newfd)
 done:
   MALLOC_CHECK;
   unlock ();
-  syscall_printf ("%d = dup2 (%d, %d)", res, oldfd, newfd);
+  syscall_printf ("%d = dup3 (%d, %d, %p)", res, oldfd, newfd, flags);
 
   return res;
 }
diff --git a/winsup/cygwin/dtable.h b/winsup/cygwin/dtable.h
index 1eedd7695..e3aa2625b 100644
--- a/winsup/cygwin/dtable.h
+++ b/winsup/cygwin/dtable.h
@@ -51,7 +51,7 @@ public:
   int vfork_child_dup ();
   void vfork_parent_restore ();
   void vfork_child_fixup ();
-  fhandler_base *dup_worker (fhandler_base *oldfh);
+  fhandler_base *dup_worker (fhandler_base *oldfh, int flags);
   int extend (int howmuch);
   void fixup_after_fork (HANDLE);
   inline int not_open (int fd)
@@ -65,7 +65,7 @@ public:
   int find_unused_handle () { return find_unused_handle (first_fd_for_open);}
   void release (int fd);
   void init_std_file_from_handle (int fd, HANDLE handle);
-  int dup2 (int oldfd, int newfd);
+  int dup3 (int oldfd, int newfd, int flags);
   void fixup_after_exec ();
   inline fhandler_base *&operator [](int fd) const { return fds[fd]; }
   bool select_read (int fd, select_stuff *);
diff --git a/winsup/cygwin/fcntl.cc b/winsup/cygwin/fcntl.cc
index 78ce36569..de13f10bf 100644
--- a/winsup/cygwin/fcntl.cc
+++ b/winsup/cygwin/fcntl.cc
@@ -1,7 +1,7 @@
 /* fcntl.cc: fcntl syscall
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2008,
-   2009 Red Hat, Inc.
+   2009, 2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -41,8 +41,10 @@ fcntl64 (int fd, int cmd, ...)
   switch (cmd)
     {
     case F_DUPFD:
+    case F_DUPFD_CLOEXEC:
       if ((int) arg >= 0 && (int) arg < OPEN_MAX_MAX)
-	res = dup2 (fd, cygheap_fdnew (((int) arg) - 1));
+	res = dup3 (fd, cygheap_fdnew (((int) arg) - 1),
+		    cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0);
       else
 	{
 	  set_errno (EINVAL);
diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index 57fcb8610..26a3ad8ee 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -1,7 +1,7 @@
 /* fhandler.cc.  See console.cc for fhandler_console functions.
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007, 2008, 2009 Red Hat, Inc.
+   2005, 2006, 2007, 2008, 2009, 2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -469,7 +469,7 @@ fhandler_base::open (int flags, mode_t mode)
 
   syscall_printf ("(%S, %p)", pc.get_nt_native_path (), flags);
 
-  pc.get_object_attr (attr, sec_none);
+  pc.get_object_attr (attr, *sec_none_cloexec (flags));
 
   switch (query_open ())
     {
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 60fe5fbf4..11162cbf1 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -399,7 +399,7 @@ class fhandler_base
 
 class fhandler_mailslot : public fhandler_base
 {
-  POBJECT_ATTRIBUTES get_object_attr (OBJECT_ATTRIBUTES &, PUNICODE_STRING);
+  POBJECT_ATTRIBUTES get_object_attr (OBJECT_ATTRIBUTES &, PUNICODE_STRING, int);
  public:
   fhandler_mailslot ();
   int __stdcall fstat (struct __stat64 *buf) __attribute__ ((regparm (2)));
diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 6cfbcf638..7a11fd22f 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -1,7 +1,7 @@
 /* fhandler_console.cc
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
-   2006, 2008, 2009 Red Hat, Inc.
+   2006, 2008, 2009, 2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -705,7 +705,7 @@ fhandler_console::open (int flags, mode_t)
 
   /* Open the input handle as handle_ */
   h = CreateFile ("CONIN$", GENERIC_READ | GENERIC_WRITE,
-		  FILE_SHARE_READ | FILE_SHARE_WRITE, &sec_none,
+		  FILE_SHARE_READ | FILE_SHARE_WRITE, sec_none_cloexec (flags),
 		  OPEN_EXISTING, 0, 0);
 
   if (h == INVALID_HANDLE_VALUE)
@@ -717,7 +717,7 @@ fhandler_console::open (int flags, mode_t)
   uninterruptible_io (true);	// Handled explicitly in read code
 
   h = CreateFile ("CONOUT$", GENERIC_READ | GENERIC_WRITE,
-		  FILE_SHARE_READ | FILE_SHARE_WRITE, &sec_none,
+		  FILE_SHARE_READ | FILE_SHARE_WRITE, sec_none_cloexec (flags),
 		  OPEN_EXISTING, 0, 0);
 
   if (h == INVALID_HANDLE_VALUE)
diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index 81519ff72..d24c73143 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -1,6 +1,6 @@
 /* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
 
-   Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Red Hat, Inc.
+   Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -70,6 +70,11 @@ fhandler_fifo::fifo_name (char *buf)
 			       PIPE_UNLIMITED_INSTANCES, (s), (s), \
 			       NMPWAIT_WAIT_FOREVER, sa_buf)
 
+inline PSECURITY_ATTRIBUTES
+sec_user_cloexec (bool cloexec, PSECURITY_ATTRIBUTES sa, PSID sid)
+{
+  return cloexec ? sec_user_nih (sa, sid) : sec_user (sa, sid);
+}
 
 int
 fhandler_fifo::open (int flags, mode_t)
@@ -94,7 +99,8 @@ fhandler_fifo::open (int flags, mode_t)
     {
       char char_sa_buf[1024];
       LPSECURITY_ATTRIBUTES sa_buf =
-	sec_user ((PSECURITY_ATTRIBUTES) char_sa_buf, cygheap->user.sid());
+	sec_user_cloexec (flags & O_CLOEXEC, (PSECURITY_ATTRIBUTES) char_sa_buf,
+			  cygheap->user.sid());
       bool do_seterrno = true;
 
       HANDLE h;
@@ -205,7 +211,9 @@ fhandler_fifo::wait (bool iswrite)
       fifo_name (npname);
       char char_sa_buf[1024];
       LPSECURITY_ATTRIBUTES sa_buf;
-      sa_buf = sec_user ((PSECURITY_ATTRIBUTES) char_sa_buf, cygheap->user.sid());
+      sa_buf = sec_user_cloexec (close_on_exec (),
+				 (PSECURITY_ATTRIBUTES) char_sa_buf,
+				 cygheap->user.sid());
       while (1)
 	{
 	  if (WaitNamedPipe (npname, 10))
diff --git a/winsup/cygwin/fhandler_mailslot.cc b/winsup/cygwin/fhandler_mailslot.cc
index a59a3dcf9..691c6043b 100644
--- a/winsup/cygwin/fhandler_mailslot.cc
+++ b/winsup/cygwin/fhandler_mailslot.cc
@@ -1,7 +1,6 @@
 /* fhandler_mailslot.cc.  See fhandler.h for a description of the fhandler classes.
 
-   Copyright 2005, 2007, 2008, 2009
-   Red Hat, Inc.
+   Copyright 2005, 2007, 2008, 2009, 2010 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -47,12 +46,15 @@ fhandler_mailslot::fstat (struct __stat64 *buf)
 
 POBJECT_ATTRIBUTES
 fhandler_mailslot::get_object_attr (OBJECT_ATTRIBUTES &attr,
-				    PUNICODE_STRING path)
+				    PUNICODE_STRING path,
+				    int flags)
 {
   
   RtlCopyUnicodeString (path, pc.get_nt_native_path ());
   RtlAppendUnicodeStringToString (path, &installation_key);
-  InitializeObjectAttributes (&attr, path, OBJ_CASE_INSENSITIVE | OBJ_INHERIT,
+  InitializeObjectAttributes (&attr, path,
+			      OBJ_CASE_INSENSITIVE
+			      | (flags & O_CLOEXEC ? 0 : OBJ_INHERIT),
 			      NULL, NULL);
   return &attr;
 }
@@ -76,7 +78,7 @@ fhandler_mailslot::open (int flags, mode_t mode)
     case O_RDONLY:	/* Server */
       timeout.QuadPart = (flags & O_NONBLOCK) ? 0LL : 0x8000000000000000LL;
       status = NtCreateMailslotFile (&x, GENERIC_READ | SYNCHRONIZE,
-				     get_object_attr (attr, &path),
+				     get_object_attr (attr, &path, flags),
 				     &io, FILE_SYNCHRONOUS_IO_NONALERT,
 				     0, 0, &timeout);
       if (!NT_SUCCESS (status))
@@ -97,7 +99,7 @@ fhandler_mailslot::open (int flags, mode_t mode)
 	      break;
 	    }
 	  status = NtOpenFile (&x, GENERIC_READ | SYNCHRONIZE,
-			       get_object_attr (attr, &path), &io,
+			       get_object_attr (attr, &path, flags), &io,
 			       FILE_SHARE_VALID_FLAGS,
 			       FILE_SYNCHRONOUS_IO_NONALERT);
 #endif
@@ -122,7 +124,7 @@ fhandler_mailslot::open (int flags, mode_t mode)
 	  break;
 	}
       status = NtOpenFile (&x, GENERIC_WRITE | SYNCHRONIZE,
-			   get_object_attr (attr, &path), &io,
+			   get_object_attr (attr, &path, flags), &io,
 			   FILE_SHARE_VALID_FLAGS,
 			   FILE_SYNCHRONOUS_IO_NONALERT);
       if (!NT_SUCCESS (status))
diff --git a/winsup/cygwin/fhandler_mem.cc b/winsup/cygwin/fhandler_mem.cc
index 7bd809472..b172cc576 100644
--- a/winsup/cygwin/fhandler_mem.cc
+++ b/winsup/cygwin/fhandler_mem.cc
@@ -1,7 +1,7 @@
 /* fhandler_mem.cc.  See fhandler.h for a description of the fhandler classes.
 
-   Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009
-   Red Hat, Inc.
+   Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009,
+   2010 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -79,7 +79,8 @@ fhandler_dev_mem::open (int flags, mode_t)
 
   OBJECT_ATTRIBUTES attr;
   InitializeObjectAttributes (&attr, &ro_u_pmem,
-			      OBJ_CASE_INSENSITIVE | OBJ_INHERIT,
+			      OBJ_CASE_INSENSITIVE
+			      | (flags & O_CLOEXEC ? 0 : OBJ_INHERIT),
 			      NULL, NULL);
 
   ACCESS_MASK section_access;
diff --git a/winsup/cygwin/fhandler_registry.cc b/winsup/cygwin/fhandler_registry.cc
index e8f4e685f..9f8e9af97 100644
--- a/winsup/cygwin/fhandler_registry.cc
+++ b/winsup/cygwin/fhandler_registry.cc
@@ -1,6 +1,7 @@
 /* fhandler_registry.cc: fhandler for /proc/registry virtual filesystem
 
-   Copyright 2002, 2003, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Red Hat, Inc.
+   Copyright 2002, 2003, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+   2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -771,6 +772,7 @@ fhandler_registry::open (int flags, mode_t mode)
 	flags |= O_DIROPEN;
 
       set_io_handle (handle);
+      set_close_on_exec (!!(flags & O_CLOEXEC));
       value_name = cwcsdup (dec_file);
 
       if (!(flags & O_DIROPEN) && !fill_filebuf ())
diff --git a/winsup/cygwin/fhandler_tape.cc b/winsup/cygwin/fhandler_tape.cc
index 22869983e..ff7e84aab 100644
--- a/winsup/cygwin/fhandler_tape.cc
+++ b/winsup/cygwin/fhandler_tape.cc
@@ -2,7 +2,7 @@
    classes.
 
    Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
-   2008 Red Hat, Inc.
+   2008, 2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -1174,7 +1174,7 @@ fhandler_dev_tape::open (int flags, mode_t)
       set_errno (ENOENT);
       return 0;
     }
-  if (!(mt_mtx = CreateMutex (&sec_all, TRUE, NULL)))
+  if (!(mt_mtx = CreateMutex (&sec_all, !!(flags & O_CLOEXEC), NULL)))
     {
       __seterrno ();
       return 0;
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 36775401f..4e4dc5338 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -581,6 +581,7 @@ fhandler_tty_slave::open (int flags, mode_t)
 
   set_io_handle (from_master_local);
   set_output_handle (to_master_local);
+  set_close_on_exec (!!(flags & O_CLOEXEC));
 
   set_open_status ();
   if (cygheap->manage_console_count ("fhandler_tty_slave::open", 1) == 1
diff --git a/winsup/cygwin/include/cygwin/version.h b/winsup/cygwin/include/cygwin/version.h
index ce8b45336..519c3a490 100644
--- a/winsup/cygwin/include/cygwin/version.h
+++ b/winsup/cygwin/include/cygwin/version.h
@@ -372,12 +372,13 @@ details. */
       216: CW_SET_EXTERNAL_TOKEN added.
       217: CW_GET_INSTKEY added.
       218: Export get_nprocs, get_nprocs_conf, get_phys_pages, get_avphys_pages.
+      219: Export dup3, pipe2, O_CLOEXEC, F_DUPFD_CLOEXEC.
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 218
+#define CYGWIN_VERSION_API_MINOR 219
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible
diff --git a/winsup/cygwin/pipe.cc b/winsup/cygwin/pipe.cc
index 39b93ccd8..2d351fd68 100644
--- a/winsup/cygwin/pipe.cc
+++ b/winsup/cygwin/pipe.cc
@@ -1,7 +1,7 @@
 /* pipe.cc: pipe for Cygwin.
 
    Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
-   2008, 2009 Hat, Inc.
+   2008, 2009, 2010 Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -53,8 +53,7 @@ fhandler_pipe::init (HANDLE f, DWORD a, mode_t mode)
   bool opened_properly = a & FILE_CREATE_PIPE_INSTANCE;
   a &= ~FILE_CREATE_PIPE_INSTANCE;
   fhandler_base::init (f, a, mode);
-  if (mode & O_NOINHERIT)
-    close_on_exec (true);
+  close_on_exec (mode & O_CLOEXEC);
   setup_overlapped (opened_properly);
   return 1;
 }
@@ -116,7 +115,7 @@ fhandler_pipe::open (int flags, mode_t mode)
       set_errno (EACCES);
       goto out;
     }
-  inh = !(flags & O_NOINHERIT);
+  inh = !(flags & O_CLOEXEC);
   if (!DuplicateHandle (proc, pipe_hdl, GetCurrentProcess (), &nio_hdl,
 			0, inh, DUPLICATE_SAME_ACCESS))
     {
@@ -124,8 +123,6 @@ fhandler_pipe::open (int flags, mode_t mode)
       goto out;
     }
   init (nio_hdl, fh->get_access (), mode & O_TEXT ?: O_BINARY);
-  if (flags & O_NOINHERIT)
-    close_on_exec (true);
   uninterruptible_io (fh->uninterruptible_io ());
   cfree (fh);
   CloseHandle (proc);
@@ -312,7 +309,7 @@ int
 fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode)
 {
   HANDLE r, w;
-  SECURITY_ATTRIBUTES *sa = (mode & O_NOINHERIT) ?  &sec_none_nih : &sec_none;
+  SECURITY_ATTRIBUTES *sa = sec_none_cloexec (mode);
   int res;
 
   int ret = create_selectable (sa, r, w, psize);
@@ -409,3 +406,9 @@ _pipe (int filedes[2], unsigned int psize, int mode)
 
   return res;
 }
+
+extern "C" int
+pipe2 (int filedes[2], int mode)
+{
+  return _pipe (filedes, DEFAULT_PIPEBUFSIZE, mode);
+}
diff --git a/winsup/cygwin/posix_ipc.cc b/winsup/cygwin/posix_ipc.cc
index 07881be05..3b0ae7802 100644
--- a/winsup/cygwin/posix_ipc.cc
+++ b/winsup/cygwin/posix_ipc.cc
@@ -1,6 +1,6 @@
 /* posix_ipc.cc: POSIX IPC API for Cygwin.
 
-   Copyright 2007, 2008, 2009 Red Hat, Inc.
+   Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -248,7 +248,7 @@ shm_open (const char *name, int oflag, mode_t mode)
       return -1;
     }
 
-  return open (shmname, oflag, mode & 0777);
+  return open (shmname, oflag | O_CLOEXEC, mode & 0777);
 }
 
 extern "C" int
@@ -351,7 +351,7 @@ again:
       va_end (ap);
 
       /* Open and specify O_EXCL and user-execute */
-      fd = open (mqname, oflag | O_EXCL | O_RDWR, mode | S_IXUSR);
+      fd = open (mqname, oflag | O_EXCL | O_RDWR | O_CLOEXEC, mode | S_IXUSR);
       if (fd < 0)
 	{
 	  if (errno == EEXIST && (oflag & O_EXCL) == 0)
@@ -435,7 +435,7 @@ again:
 
 exists:
   /* Open the file then memory map */
-  if ((fd = open (mqname, O_RDWR)) < 0)
+  if ((fd = open (mqname, O_RDWR | O_CLOEXEC)) < 0)
     {
       if (errno == ENOENT && (oflag & O_CREAT))
 	goto again;
@@ -944,7 +944,7 @@ again:
       va_end (ap);
 
       /* Open and specify O_EXCL and user-execute */
-      fd = open (semname, oflag | O_EXCL | O_RDWR, mode | S_IXUSR);
+      fd = open (semname, oflag | O_EXCL | O_RDWR | O_CLOEXEC, mode | S_IXUSR);
       if (fd < 0)
 	{
 	  if (errno == EEXIST && (oflag & O_EXCL) == 0)
@@ -974,7 +974,7 @@ again:
 
 exists:
   /* Open the file and fetch the semaphore name. */
-  if ((fd = open (semname, O_RDWR)) < 0)
+  if ((fd = open (semname, O_RDWR | O_CLOEXEC)) < 0)
     {
       if (errno == ENOENT && (oflag & O_CREAT))
 	goto again;
diff --git a/winsup/cygwin/security.h b/winsup/cygwin/security.h
index 4de76aa99..f9538c129 100644
--- a/winsup/cygwin/security.h
+++ b/winsup/cygwin/security.h
@@ -437,6 +437,8 @@ extern SECURITY_ATTRIBUTES *__stdcall __sec_user (PVOID sa_buf, PSID sid1, PSID
 extern PSECURITY_DESCRIPTOR _everyone_sd (void *buf, ACCESS_MASK access);
 #define everyone_sd(access)	(_everyone_sd (alloca (SD_MIN_SIZE), (access)))
 
+#define sec_none_cloexec(f) (((f) & O_CLOEXEC ? &sec_none_nih : &sec_none))
+
 extern bool sec_acl (PACL acl, bool original, bool admins, PSID sid1 = NO_SID,
 		     PSID sid2 = NO_SID, DWORD access2 = 0);
 
@@ -460,4 +462,5 @@ sec_user (SECURITY_ATTRIBUTES *sa_buf, PSID sid1, PSID sid2 = NULL,
 {
   return __sec_user (sa_buf, sid1, sid2, access2, TRUE);
 }
+
 #endif /*_SECURITY_H*/
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index ec589712a..bd3308a42 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -116,13 +116,13 @@ close_all_files (bool norelease)
   cygheap->fdtab.unlock ();
 }
 
-int
+extern "C" int
 dup (int fd)
 {
-  return cygheap->fdtab.dup2 (fd, cygheap_fdnew ());
+  return cygheap->fdtab.dup3 (fd, cygheap_fdnew (), 0);
 }
 
-int
+extern "C" int
 dup2 (int oldfd, int newfd)
 {
   if (newfd >= OPEN_MAX_MAX)
@@ -131,7 +131,39 @@ dup2 (int oldfd, int newfd)
       set_errno (EBADF);
       return -1;
     }
-  return cygheap->fdtab.dup2 (oldfd, newfd);
+  if (newfd == oldfd)
+    {
+      cygheap_fdget cfd (oldfd);
+      if (cfd < 0)
+	{
+	  syscall_printf ("-1 = dup2 (%d, %d) (oldfd not open)", oldfd, newfd);
+	  return -1;
+	}
+      syscall_printf ("%d = dup2 (%d, %d) (newfd==oldfd)", oldfd, oldfd, newfd);
+      return oldfd;
+    }
+  return cygheap->fdtab.dup3 (oldfd, newfd, 0);
+}
+
+extern "C" int
+dup3 (int oldfd, int newfd, int flags)
+{
+  if (newfd >= OPEN_MAX_MAX)
+    {
+      syscall_printf ("-1 = dup3 (%d, %d, %p) (%d too large)",
+		      oldfd, newfd, flags, newfd);
+      set_errno (EBADF);
+      return -1;
+    }
+  if (newfd == oldfd)
+    {
+      cygheap_fdget cfd (oldfd, false, false);
+      set_errno (cfd < 0 ? EBADF : EINVAL);
+      syscall_printf ("-1 = dup3 (%d, %d, %p) (newfd==oldfd)",
+		      oldfd, newfd, flags);
+      return -1;
+    }
+  return cygheap->fdtab.dup3 (oldfd, newfd, flags);
 }
 
 static char desktop_ini[] =
@@ -1037,16 +1069,20 @@ open (const char *unix_path, int flags, ...)
 	      delete fh;
 	      res = -1;
 	    }
-	  else if (!fh->open (flags, (mode & 07777) & ~cygheap->umask))
-	    {
-	      delete fh;
-	      res = -1;
-	    }
 	  else
 	    {
-	      cygheap->fdtab[fd] = fh;
-	      if ((res = fd) <= 2)
-		set_std_handle (res);
+	      fh->close_on_exec (flags & O_CLOEXEC);
+	      if (!fh->open (flags, (mode & 07777) & ~cygheap->umask))
+		{
+		  delete fh;
+		  res = -1;
+		}
+	      else
+		{
+		  cygheap->fdtab[fd] = fh;
+		  if ((res = fd) <= 2)
+		    set_std_handle (res);
+		}
 	    }
 	}
     }