From fb852844d2172fba9690b36b89d97c671ec52978 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 22 Jul 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-07-22

---
 gnot/trap.c  |  8 ++++++++
 pc/trap.c    | 12 +++++++++---
 port/chan.c  | 15 ++++++++++++++-
 power/trap.c |  1 +
 ss/trap.c    |  8 ++++++++
 5 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/gnot/trap.c b/gnot/trap.c
index a48ba88e884cdce08ead648c1f5b943033aa922e..1bf8261228a1ec06a513479ec137f5ff1f379efd 100644
--- a/gnot/trap.c
+++ b/gnot/trap.c
@@ -162,6 +162,14 @@ notify(Ureg *ur)
 		u->svsr = ur->sr;
 		sp = ur->usp;
 		sp -= sizeof(Ureg);
+		if(waserror()){
+			pprint("suicide: trap in notify\n");
+			unlock(&u->p->debug);
+			pexit("Suicide", 0);
+		}
+		validaddr((ulong)u->notify, 1, 0);
+		validaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 0);
+		poperror();
 		u->ureg = (void*)sp;
 		memmove((Ureg*)sp, ur, sizeof(Ureg));
 		sp -= ERRLEN;
diff --git a/pc/trap.c b/pc/trap.c
index 563045fd4b41467cb589a10af0070ba0fc2189a5..0a6300ae762b2eb9f827b1af52ab797778eb9f86 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -303,6 +303,14 @@ notify(Ureg *ur)
 		u->svflags = ur->flags;
 		sp = ur->usp;
 		sp -= sizeof(Ureg);
+		if(waserror()){
+			pprint("suicide: trap in notify\n");
+			unlock(&u->p->debug);
+			pexit("Suicide", 0);
+		}
+		validaddr((ulong)u->notify, 1, 0);
+		validaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 0);
+		poperror();
 		u->ureg = (void*)sp;
 		memmove((Ureg*)sp, ur, sizeof(Ureg));
 		sp -= ERRLEN;
@@ -351,9 +359,7 @@ noted(Ureg *ur, ulong arg0)
 	case NCONT:
 		splhi();
 		unlock(&u->p->debug);
-		rfnote(ur);
-		break;
-		/* never returns */
+		return;
 
 	default:
 		pprint("unknown noted arg 0x%lux\n", arg0);
diff --git a/port/chan.c b/port/chan.c
index d6994fa45fa99295505554d87318cc9bf47b1ab3..94432d96a639732de299402d5f0c84cc64d29d78 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -22,16 +22,29 @@ incref(Ref *r)
 	return x;
 }
 
+#include "ureg.h"
+
 int
 decref(Ref *r)
 {
 	int x;
+	int i;
+	Segment *s;
 
 	lock(r);
 	x = --r->ref;
 	unlock(r);
-	if(x < 0)
+	if(x < 0) {
+		if(u) {
+			print("%d: %s %lux %lux\n", u->p->pid, u->p->text, *(ulong*)((Ureg*)UREGADDR)->pc, r);
+			for(i = 0; i < NSEG; i++) {
+				s = u->p->seg[i];
+				if(s)
+					print("%d: %lux %lux %lux", i, s, s->base, s->top);
+			}
+		}
 		panic("decref");
+	}
 	return x;
 }
 
diff --git a/power/trap.c b/power/trap.c
index b5ae91d6f027d1eaca4d20a1e9a714b5b6759c56..ee6858195e2bb8b8cf5232c01f7b7a4dd5f46393 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -392,6 +392,7 @@ notify(Ureg *ur)
 		sp -= sizeof(Ureg);
 		if(waserror()){
 			pprint("suicide: trap in notify\n");
+			unlock(&u->p->debug);
 			pexit("Suicide", 0);
 		}
 		validaddr((ulong)u->notify, 1, 0);
diff --git a/ss/trap.c b/ss/trap.c
index 846d4708b05406da5fda29c16925a4a53352e4f5..6c1963f336c38a2fce18eb692bd8d1fec9faead8 100644
--- a/ss/trap.c
+++ b/ss/trap.c
@@ -235,6 +235,14 @@ notify(Ureg *ur)
 		u->svpsr = ur->psr;
 		sp = ur->usp;
 		sp -= sizeof(Ureg);
+		if(waserror()){
+			pprint("suicide: trap in notify\n");
+			unlock(&u->p->debug);
+			pexit("Suicide", 0);
+		}
+		validaddr((ulong)u->notify, 1, 0);
+		validaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 0);
+		poperror();
 		u->ureg = (void*)sp;
 		memmove((Ureg*)sp, ur, sizeof(Ureg));
 		sp -= ERRLEN;