Index: sys/arm64/arm64/machdep.c
===================================================================
--- sys/arm64/arm64/machdep.c
+++ sys/arm64/arm64/machdep.c
@@ -236,7 +236,7 @@
 		regs->fp_sr = pcb->pcb_fpustate.vfp_fpsr;
 	} else
 #endif
-		memset(regs->fp_q, 0, sizeof(regs->fp_q));
+		memset(regs, 0, sizeof(*regs));
 	return (0);
 }