What I blamed on a specific CMMU fault pecularity turned out to be, in fact,

a nice bug preventing signals to be delivered to process faulting in some
conditions...

1 files changed, 4 insertions, 23 deletions

diff --git a/sys/arch/mvme88k/mvme88k/trap.c b/sys/arch/mvme88k/mvme88k/trap.c
index 69234940439..96cb8dfe265 100644
--- a/sys/arch/mvme88k/mvme88k/trap.c
+++ b/sys/arch/mvme88k/mvme88k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.47 2003/09/03 20:18:18 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.48 2003/09/04 18:14:46 miod Exp $	*/
 /*
  * Copyright (c) 1998 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -465,7 +465,6 @@ user_fault:
 			break;
 		default:
 			result = uvm_fault(map, va, 0, ftype);
-			frame->ipfsr = frame->dpfsr = 0;
 			break;
 		}
 
@@ -496,27 +495,9 @@ user_fault:
 				 */
 				frame->sfip = frame->snip & ~FIP_E;
 				frame->snip = frame->sxip & ~NIP_E;
+				frame->ipfsr = 0;
 			}
 		} else {
-			/*
-			 * XXX
-			 * Page faults for addresses in page zero _SEEM TO BE_
-			 * special.
-			 * For some reason, we will keep faulting with the same
-			 * cause when the interrupts get enabled, later in the
-			 * exception process, and eventually eat all the
-			 * interrupt stack in a recursive DAE.
-			 * Since accesses to this page will always result in a
-			 * SIGSEGV, we can safely clear the DAE condition here.
-			 *
-			 * (behaviour experienced on MVME187C)
-			 */
-			if (va == 0 && type == (T_DATAFLT + T_USER) &&
-			    SYSTEMMODE(frame->epsr)) {
-				frame->dpfsr = 0;
-				frame->dmt0 = 0;
-			}
-
 			sig = result == EACCES ? SIGBUS : SIGSEGV;
 			fault_type = result == EACCES ?
 				BUS_ADRERR : SEGV_MAPERR;
@@ -666,7 +647,7 @@ user_fault:
 	/*
 	 * If trap from supervisor mode, just return
 	 */
-	if (SYSTEMMODE(frame->epsr))
+	if (type < T_USER)
 		return;
 
 	if (sig) {
@@ -677,7 +658,7 @@ user_fault:
 		 * deliver signal.
 		 */
 		frame->dmt0 = 0;
-		frame->dpfsr = 0;
+		frame->ipfsr = frame->dpfsr = 0;
 	}
 
 	userret(p, frame, sticks);