--- a/sys/vfs/procfs/procfs_regs.c
+++ b/sys/vfs/procfs/procfs_regs.c
@@ -65,7 +65,7 @@ procfs_doregs(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
 	if (error == 0)
 		error = uiomove_frombuf(&r, sizeof(r), uio);
 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
-		if (p->p_stat != SSTOP)
+		if (lp->lwp_stat != LSSTOP)
 			error = EBUSY;
 		else
 			error = procfs_write_regs(lp, &r);