--- qemu/linux-user/mips/syscall.h	2018/04/24 16:48:14	1.1.1.2
+++ qemu/linux-user/mips/syscall.h	2018/04/24 17:23:02	1.1.1.3
@@ -221,4 +221,7 @@ struct target_pt_regs {
 
 
 
+/* Nasty hack: define a fake errno value for use by sigreturn.  */
+#define TARGET_QEMU_ESIGRETURN 255
+
 #define UNAME_MACHINE "mips"