2011-09-02 Pedro Alves <pedro@codesourcery.com>

2011-09-02  Pedro Alves  <pedro@codesourcery.com>

	* linux-nat.c (in_pid_list_p): New.
	(linux_record_stopped_pid): Delete.
	(lin_lwp_attach_lwp): Check if PTRACE_ATTACH failed because we're
	already attached to the LWP.  Return an indication if so.
	(linux_nat_filter_event): Adjust.
	* linux-thread-db.c (attach_thread): Handle lin_lwp_attach_lwp
	returning an indication to ignore this thread.