Correctly handle 88110 exceptions occuring in a delay slot: control must

be restored with valid EXIP+D and ENIP values in this case, unless it is
decided to skip instructions.

2 files changed, 34 insertions, 19 deletions

diff --git a/sys/arch/mvme88k/mvme88k/eh.S b/sys/arch/mvme88k/mvme88k/eh.S
index bc44b556ceb..05c3299bac8 100644
--- a/sys/arch/mvme88k/mvme88k/eh.S
+++ b/sys/arch/mvme88k/mvme88k/eh.S
@@ -1,4 +1,4 @@
-/*   $OpenBSD: eh.S,v 1.48 2004/01/19 17:21:25 miod Exp $   */
+/*   $OpenBSD: eh.S,v 1.49 2004/01/29 00:41:23 miod Exp $   */
 /*
  * Mach Operating System
  * Copyright (c) 1993-1991 Carnegie Mellon University
@@ -2471,16 +2471,12 @@ ASLOCAL(m88110_have_pcb)
 	ldcr	TMP,  EPSR
 	st	TMP,  r31,  REG_OFF(EF_EPSR)
 	ldcr	TMP2, EXIP
-	st	TMP2, r31,  REG_OFF(EF_EXIP)
+	/* if the instruction was NOT in the delay slot, ignore ENIP */
 	bb0.n	0,    TMP2, 1f
-	/* The instruction was NOT in the delay slot, zero ENIP. */
-	 st	r0,   r31,  REG_OFF(EF_ENIP)
-	/* The instruction was in the delay slot, save ENIP. */
+	 st	TMP2, r31,  REG_OFF(EF_EXIP)
 	ldcr	TMP3, ENIP
 	st	TMP3, r31,  REG_OFF(EF_ENIP)
 1:
-	/* NO SFIP on mc88110, zero it */
-	st	r0,   r31,  REG_OFF(EF_SFIP)
 
 	/* get and store the cpu number */
 	extu	TMP,  FLAGS,  FLAG_CPU_FIELD_WIDTH<0>	/* TMP = cpu# */
diff --git a/sys/arch/mvme88k/mvme88k/trap.c b/sys/arch/mvme88k/mvme88k/trap.c
index 60c48c2541d..a594e51d19f 100644
--- a/sys/arch/mvme88k/mvme88k/trap.c
+++ b/sys/arch/mvme88k/mvme88k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.70 2004/01/20 14:34:40 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.71 2004/01/29 00:41:23 miod Exp $	*/
 /*
  * Copyright (c) 1998 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -728,11 +728,12 @@ m88110_trap(unsigned type, struct trapframe *frame)
 		db_enable_interrupt();
 		ddb_entry_trap(T_KDB_ENTRY, (db_regs_t*)frame);
 		db_disable_interrupt();
-		if (frame->tf_enip) {
+		/* skip one instruction */
+		if (frame->tf_exip & 1)
 			frame->tf_exip = frame->tf_enip;
-		} else {
+		else
 			frame->tf_exip += 4;
-		}
+		frame->tf_enip = 0;
 		splx(s);
 		return;
 #if 0
@@ -819,6 +820,7 @@ m88110_trap(unsigned type, struct trapframe *frame)
 			    (frame->tf_exip & XIP_ADDR) <=
 			      (unsigned)&guarded_access_end) {
 				frame->tf_exip = (unsigned)&guarded_access_bad;
+				frame->tf_enip = 0;
 				return;
 			}
 		}
@@ -1006,6 +1008,7 @@ m88110_user_fault:
 		 */
 		if (result != 0 && p->p_addr->u_pcb.pcb_onfault != NULL) {
 			frame->tf_exip = p->p_addr->u_pcb.pcb_onfault;
+			frame->tf_enip = 0;
 			frame->tf_dsr = frame->tf_isr = 0;
 			/*
 			 * Continue as if the fault had been resolved.
@@ -1469,8 +1472,12 @@ m88110_syscall(register_t code, struct trapframe *tf)
 		tf->tf_r[2] = rval[0];
 		tf->tf_r[3] = rval[1];
 		tf->tf_epsr &= ~PSR_C;
-		tf->tf_exip += 4 + 4;
-		tf->tf_exip &= XIP_ADDR;
+		/* skip two instructions */
+		if (tf->tf_exip & 1)
+			tf->tf_exip = tf->tf_enip + 4;
+		else
+			tf->tf_exip += 4 + 4;
+		tf->tf_enip = 0;
 		break;
 	case ERESTART:
 		/*
@@ -1482,16 +1489,24 @@ m88110_syscall(register_t code, struct trapframe *tf)
 		break;
 	case EJUSTRETURN:
 		tf->tf_epsr &= ~PSR_C;
-		tf->tf_exip += 4;
-		tf->tf_exip &= XIP_ADDR;
+		/* skip one instruction */
+		if (tf->tf_exip & 1)
+			tf->tf_exip = tf->tf_enip;
+		else
+			tf->tf_exip += 4;
+		tf->tf_enip = 0;
 		break;
 	default:
 		if (p->p_emul->e_errno)
 			error = p->p_emul->e_errno[error];
 		tf->tf_r[2] = error;
 		tf->tf_epsr |= PSR_C;   /* fail */
-		tf->tf_exip += 4;
-		tf->tf_exip &= XIP_ADDR;
+		/* skip one instruction */
+		if (tf->tf_exip & 1)
+			tf->tf_exip = tf->tf_enip;
+		else
+			tf->tf_exip += 4;
+		tf->tf_enip = 0;
 		break;
 	}
 
@@ -1525,8 +1540,12 @@ child_return(arg)
 		tf->tf_snip = tf->tf_sfip & XIP_ADDR;
 		tf->tf_sfip = tf->tf_snip + 4;
 	} else {
-		tf->tf_exip += 4 + 4;
-		tf->tf_exip &= XIP_ADDR;
+		/* skip two instructions */
+		if (tf->tf_exip & 1)
+			tf->tf_exip = tf->tf_enip + 4;
+		else
+			tf->tf_exip += 4 + 4;
+		tf->tf_enip = 0;
 	}
 
 	userret(p, tf, p->p_sticks);