Index: lib/libc/mips/gen/_ctx_start.S
===================================================================
--- lib/libc/mips/gen/_ctx_start.S
+++ lib/libc/mips/gen/_ctx_start.S
@@ -28,11 +28,19 @@
 __FBSDID("$FreeBSD$");
 
 /*
- * XXX gp?
+ * This assumes that the inherited GP from getcontext() matches the GP
+ * needed by _ctx_start().  For O32, save GP in S1 while invoking the
+ * callback.
  */
 ENTRY(_ctx_start)
+#ifdef __mips_o32
+	move	s1, gp
+#endif
 	jalr	t9
 
+#ifdef __mips_o32
+	move	gp, s1
+#endif
 	move	a0, s0
 	PTR_LA	t9, _ctx_done
 	jalr	t9