Index: sys/arm64/arm64/machdep.c
===================================================================
--- sys/arm64/arm64/machdep.c
+++ sys/arm64/arm64/machdep.c
@@ -222,7 +222,8 @@
 		 * If we have just been running VFP instructions we will
 		 * need to save the state to memcpy it below.
 		 */
-		vfp_save_state(td, pcb);
+		if (td == curthread)
+			vfp_save_state(td, pcb);
 
 		KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
 		    ("Called fill_fpregs while the kernel is using the VFP"));