* autoload.cc (GetNamedPipeClientProcessId): Define.

* fhandler.h (fhandler_tty_slave::fch_open_handles): Declare private.
	(fhandler_tty_slave::fch_close_handles): Ditto.
	(fhandler_tty_slave::cygserver_attach_tty): Drop declaration.
	(fhandler_tty_slave::fstat): Declare public.
	(fhandler_tty_slave::fchmod): Declare public.
	(fhandler_tty_slave::fchown): Declare public.
	(class fhandler_pty_master): Add master_ctl handle.
	(fhandler_pty_master::pty_master_thread): Declare public.
	* fhandler_termios.cc (fhandler_termios::tcinit): If the process
	is started from a non-Cygwin process, make it tty process group
	leader.
	* fhandler_tty.cc: Throughout accommodate additional security related
	arguments in calls to functions creating or opening objects.
	(close_maybe): Move to start of file to reuse it
	in other methods.
	(struct pipe_request): Define.
	(struct pipe_reply): Define.
	(fhandler_tty_slave::open): Throughout, try to open synchronization
	objects with MAXIMUM_ALLOWED permissions.  Drop call to cygserver.
	Try to duplicate pipe handles via master_ctl pipe if duplicating
	directly doesn't work.
	(fhandler_tty_slave::cygserver_attach_tty): Remove.
	(fhandler_tty_slave::init): Close unused incoming pipe handle.
	(fhandler_pty_master::close): Send exit message to master control
	thread and close master_ctl handle.
	(fhandler_pty_master::pty_master_thread): New method, implementing the
	master control thread.
	(pty_master_thread): Static helper to start master control thread.
	(fhandler_pty_master::setup): Simplify creating pipe inheritance.
	Make sure we're the one creating the input_available_event.  Add
	comment to explain why.  Create master_ctl pipe and start master
	control thread.  Close master_ctl handle in case of error.
	* security.cc (alloc_sd): Add code to handle tty objects.  Add comments
	to explain what exactly is required.
	(get_object_sd): New function.
	(get_object_attribute): New function.
	(create_object_sd_from_attribute): New function.
	(set_object_sd): New function.
	(set_object_attribute): New function.
	(set_file_attribute): Change attribute type to mode_t.
	* security.h (set_file_attribute): Change attribute type to mode_t.
	(get_object_sd): Declare.
	(get_object_attribute): Declare.
	(create_object_sd_from_attribute): Declare.
	(set_object_sd): Declare.
	(set_object_attribute): Declare.
	* tty.cc (tty::slave_alive): Implement directly instead of via alive.
	(tty::exists): Open mutex handle with READ_CONTROL access.
	(tty::alive): Remove.
	(tty::open_output_mutex): Convert to inline method.
	(tty::open_input_mutex): Ditto.
	(tty::open_mutex): Take additional ACCESS_MASK parameter for the
	mutex open access mask.
	(tty::open_inuse): New method.
	(tty::create_inuse): Take PSECURITY_ATTRIBUTES parameter.  Drop fmt
	name parameter.  Always create TTY_SLAVE_ALIVE event.
	(tty::get_event): Take additional PSECURITY_ATTRIBUTES parameter for
	CreateEvent.
	* tty.h (class tty): Change declarations according to aforementioned
	changes.
	(tty::open_output_mutex): Implement as inline method.
	(tty::open_input_mutex): Ditto.

winsup/cygwin/autoload.cc

@@ -419,6 +419,7 @@ LoadDLLfuncEx (FindFirstVolumeA, 8, kernel32, 1)
 LoadDLLfuncEx (FindNextVolumeA, 12, kernel32, 1)
 LoadDLLfuncEx (FindVolumeClose, 4, kernel32, 1)
 LoadDLLfuncEx (GetConsoleWindow, 0, kernel32, 1)
+LoadDLLfuncEx (GetNamedPipeClientProcessId, 8, kernel32, 1)
 LoadDLLfuncEx (GetSystemWindowsDirectoryW, 8, kernel32, 1)
 LoadDLLfuncEx (GetVolumeNameForVolumeMountPointA, 12, kernel32, 1)
 LoadDLLfuncEx (GetSystemDEPPolicy, 0, kernel32, 1)