diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4ee17b31e55..fb99d260ff5 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2015-01-09  Pedro Alves  <palves@redhat.com>
+
+	* linux-nat.c (lin_lwp_attach_lwp): Assert that the lwp id we're
+	about to wait for is > 0.
+	* linux-thread-db.c (find_new_threads_callback): Ignore thread if
+	the kernel thread ID is -1.
+
 2015-01-09  Pedro Alves  <palves@redhat.com>
 
 	* linux-nat.c (attach_proc_task_lwp_callback): New function.
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 2ee6a00f83d..d6bafae9b8d 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-09  Pedro Alves  <palves@redhat.com>
+
+	* thread-db.c (find_new_threads_callback): Ignore thread if the
+	kernel thread ID is -1.
+
 2015-01-09  Pedro Alves  <palves@redhat.com>
 
 	* linux-low.c (linux_attach_fail_reason_string): Move to
diff --git a/gdb/gdbserver/thread-db.c b/gdb/gdbserver/thread-db.c
index 4e0d32acfce..b0d1f0d945a 100644
--- a/gdb/gdbserver/thread-db.c
+++ b/gdb/gdbserver/thread-db.c
@@ -396,6 +396,17 @@ find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
   if (err != TD_OK)
     error ("Cannot get thread info: %s", thread_db_err_str (err));
 
+  if (ti.ti_lid == -1)
+    {
+      /* A thread with kernel thread ID -1 is either a thread that
+	 exited and was joined, or a thread that is being created but
+	 hasn't started yet, and that is reusing the tcb/stack of a
+	 thread that previously exited and was joined.  (glibc marks
+	 terminated and joined threads with kernel thread ID -1.  See
+	 glibc PR17707.  */
+      return 0;
+    }
+
   /* Check for zombies.  */
   if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
     return 0;
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 0adf3a9c769..77aa8e31377 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -1023,6 +1023,7 @@ lin_lwp_attach_lwp (ptid_t ptid)
 
 		  /* See if we've got a stop for this new child
 		     pending.  If so, we're already attached.  */
+		  gdb_assert (lwpid > 0);
 		  new_pid = my_waitpid (lwpid, &status, WNOHANG);
 		  if (new_pid == -1 && errno == ECHILD)
 		    new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG);
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index b7afb039d2c..1417542a6b6 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -1610,6 +1610,17 @@ find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
     error (_("find_new_threads_callback: cannot get thread info: %s"),
 	   thread_db_err_str (err));
 
+  if (ti.ti_lid == -1)
+    {
+      /* A thread with kernel thread ID -1 is either a thread that
+	 exited and was joined, or a thread that is being created but
+	 hasn't started yet, and that is reusing the tcb/stack of a
+	 thread that previously exited and was joined.  (glibc marks
+	 terminated and joined threads with kernel thread ID -1.  See
+	 glibc PR17707.  */
+      return 0;
+    }
+
   if (ti.ti_tid == 0)
     {
       /* A thread ID of zero means that this is the main thread, but