And ... more discussion occurs between miod and kettenis about

what register dance copyerr should do.....

diff --git a/sys/arch/alpha/alpha/locore.s b/sys/arch/alpha/alpha/locore.s
index 14ad265..6ecedc1 100644 (file)
--- a/sys/arch/alpha/alpha/locore.s
+++ b/sys/arch/alpha/alpha/locore.s
@@ -1,4 +1,4 @@
-/* $OpenBSD: locore.s,v 1.39 2015/06/05 18:36:07 deraadt Exp $ */
+/* $OpenBSD: locore.s,v 1.40 2015/06/05 19:36:28 deraadt Exp $ */
 /* $NetBSD: locore.s,v 1.94 2001/04/26 03:10:44 ross Exp $ */
 
 /*-
@@ -1061,7 +1061,8 @@ NESTED(copyout, 3, 16, ra, IM_RA|IM_S0, 0)
 LEAF(copyerr, 0)
        LDGP(pv)
        .set noat
-       ldq     at_reg, P_ADDR(at_reg)          /* clear handler.            */
+       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
+       ldq     at_reg, P_ADDR(at_reg)
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */