From 64e77d4402970c246d0847745b7fe8dfd4d8dc70 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 14 Aug 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-08-14

---
 gnot/dat.h    |   2 +-
 gnot/trap.c   |  14 ++++-
 pc/devhard.c  | 167 +++++++++++++++++++++++++++-----------------------
 pc/trap.c     |  10 +++
 port/devmnt.c |  98 ++++++++++++++++++-----------
 power/trap.c  |  14 ++++-
 ss/trap.c     |  14 ++++-
 7 files changed, 196 insertions(+), 123 deletions(-)

diff --git a/gnot/dat.h b/gnot/dat.h
index a26445cc5eb721a74fdff7a0d222b19c72106aac..a6fb38a5f395e388410cde432db3ef0da395c166 100644
--- a/gnot/dat.h
+++ b/gnot/dat.h
@@ -200,7 +200,7 @@ struct Scsi
 	uchar	cmdblk[16];
 };
 
-#define	NERR	15
+#define	NERR	25
 #define	NNOTE	5
 struct User
 {
diff --git a/gnot/trap.c b/gnot/trap.c
index d094d9a9f03f27a28b5dae4746e795c5cc8069fa..03c312f2e6122091b22ddab0fed1cce6ee702b14 100644
--- a/gnot/trap.c
+++ b/gnot/trap.c
@@ -199,21 +199,29 @@ noted(Ureg *ur, ulong arg0)
 	Ureg *nur;
 
 	nur = u->ureg;
-	validaddr(nur->pc, 1, 0);
-	validaddr(nur->usp, BY2WD, 0);
 	if(nur->sr!=u->svsr || nur->vo!=u->svvo){
 		pprint("bad noted ureg sr %ux vo %ux\n", nur->sr, nur->vo);
+    Die:
 		pexit("Suicide", 0);
 	}
 	lock(&u->p->debug);
 	if(!u->notified){
 		unlock(&u->p->debug);
-		return;
+		pprint("call to noted() when not notified\n");
+		goto Die;
 	}
 	u->notified = 0;
 	memmove(ur, u->ureg, sizeof(Ureg));
 	switch(arg0){
 	case NCONT:
+		if(waserror()){
+			pprint("suicide: trap in noted\n");
+			unlock(&u->p->debug);
+			goto Die;
+		}
+		validaddr(nur->pc, 1, 0);
+		validaddr(nur->usp, BY2WD, 0);
+		poperror();
 		splhi();
 		unlock(&u->p->debug);
 		rfnote(ur);
diff --git a/pc/devhard.c b/pc/devhard.c
index 257b2197bff77a8ae56e08622b04034a6b730f04..4016b6617d207a67e0f7a21313a155eed3361577 100644
--- a/pc/devhard.c
+++ b/pc/devhard.c
@@ -10,7 +10,6 @@ typedef	struct Drive		Drive;
 typedef	struct Ident		Ident;
 typedef	struct Controller	Controller;
 typedef struct Partition	Partition;
-typedef struct Ptable		Ptable;
 
 enum
 {
@@ -45,7 +44,7 @@ enum
 	Qmask=		(3<<(3+3)),
 
 	Maxxfer=	4*1024,		/* maximum transfer size/cmd */
-	Npart=		8+1,		/* 8 sub partitions and one for the disk */
+	Npart=		8+2,		/* 8 sub partitions, disk, and partiiton */
 };
 #define PART(x)		((x)&0x3)
 #define DRIVE(x)	(((x)>>3)&0x7)
@@ -93,19 +92,7 @@ struct Partition
 {
 	ulong	start;
 	ulong	end;
-	uchar	name[NAMELEN];
-};
-
-struct Ptable 
-{
-	uchar		magic[4];	/* ascii "disk" */
-	uchar		n[4];		/* number of partitions */
-	struct
-	{
-		uchar	start[4];	/* starting block */
-		uchar	end[4];		/* ending block */
-		uchar	name[NAMELEN];
-	} p[1];
+	char	name[NAMELEN+1];
 };
 
 /*
@@ -159,11 +146,9 @@ struct Controller
 
 Controller	*hardc;
 Drive		*hard;
-Dirtab 		*harddir;
-#define NHDIR	2	/* directory entries/drive */
 
 static void	hardintr(Ureg*);
-static long	hardxfer(Drive*, int, void*, long, long);
+static long	hardxfer(Drive*, Partition*, int, void*, long, long);
 static long	hardident(Drive*);
 static void	hardsetbuf(Drive*, int);
 static void	hardpart(Drive*);
@@ -173,33 +158,30 @@ hardgen(Chan *c, Dirtab *tab, long ntab, long s, Dir *dirp)
 {
 	Qid qid;
 	int drive;
-	char *name;
+	char name[NAMELEN];
 	Drive *dp;
 	Partition *pp;
 	ulong l;
 
 	qid.vers = 0;
-	drive = s/(Npart+1);
-	s = s % (Npart+1);
+	drive = s/Npart;
+	s = s % Npart;
 	if(drive >= conf.nhard)
 		return -1;
 	dp = &hard[drive];
 
-	if(s == 0){
-		sprint(name, "hd%dparition", drive);
-		qid.path = MKQID(Qpart, drive, 0);
-		l = dp->npart * sizeof(Partition);
-	} else if(s-1 < p.npart){
-		pp = &dp->p[s-1];
+	if(s < dp->npart){
+		pp = &dp->p[s];
 		sprint(name, "hd%d%s", drive, pp->name);
-		qid.path = MKQID(Qdata, drive, s-1);
-		l = (pp->end - pp->start) * dp->cp->bytes;
+		qid.path = MKQID(Qdata, drive, s);
+		l = (pp->end - pp->start) * dp->bytes;
 	} else
 		return 0;
 
 	devdir(c, qid, name, l, 0600, dirp);
 	return 1;
 }
+
 /*
  *  we assume drives 0 and 1 are on the first controller, 2 and 3 on the
  *  second, etc.
@@ -210,11 +192,9 @@ hardreset(void)
 	Drive *dp;
 	Controller *cp;
 	int drive;
-	Dirtab *dir;
 
 	hard = ialloc(conf.nhard * sizeof(Drive), 0);
 	hardc = ialloc(((conf.nhard+1)/2 + 1) * sizeof(Controller), 0);
-	dir = harddir = ialloc(NHDIR * conf.nhard * sizeof(Dirtab), 0);
 	
 	for(drive = 0; drive < conf.nhard; drive++){
 		dp = &hard[drive];
@@ -228,16 +208,6 @@ hardreset(void)
 			cp->pbase = Pbase + (cp-hardc)*8;	/* BUG!! guessing */
 			setvec(Hardvec + (cp-hardc)*8, hardintr); /* BUG!! guessing */
 		}
-		sprint(harddir[drive*2].name, "hd%ddata", drive);
-		dir->length = 0;
-		dir->qid.path = Qdata + drive;
-		dir->perm = 0600;
-		dir++;
-		sprint(dir->name, "hd%dstruct", drive);
-		dir->length = 8;
-		dir->qid.path = Qstruct + drive;
-		dir->perm = 0600;
-		dir++;
 	}
 }
 
@@ -260,14 +230,13 @@ hardattach(char *spec)
 			dp->bytes = 512;
 			hardsetbuf(dp, 1);
 			hardident(dp);
-			hardpart(dp);
 			dp->cyl = dp->id.lcyls;
 			dp->heads = dp->id.lheads;
 			dp->sectors = dp->id.ls2t;
 			dp->bytes = 512;
 			dp->cap = dp->bytes * dp->cyl * dp->heads * dp->sectors;
-			harddir[NHDIR*dp->drive].length = dp->cap;
 			dp->online = 1;
+			hardpart(dp);
 			poperror();
 		} else
 			dp->online = 0;
@@ -285,19 +254,19 @@ hardclone(Chan *c, Chan *nc)
 int
 hardwalk(Chan *c, char *name)
 {
-	return devwalk(c, name, harddir, conf.nhard*NHDIR, devgen);
+	return devwalk(c, name, 0, 0, hardgen);
 }
 
 void
 hardstat(Chan *c, char *dp)
 {
-	devstat(c, dp, harddir, conf.nhard*NHDIR, devgen);
+	devstat(c, dp, 0, 0, hardgen);
 }
 
 Chan*
 hardopen(Chan *c, int omode)
 {
-	return devopen(c, omode, harddir, conf.nhard*NHDIR, devgen);
+	return devopen(c, omode, 0, 0, hardgen);
 }
 
 void
@@ -323,43 +292,29 @@ hardwstat(Chan *c, char *dp)
 	error(Eperm);
 }
 
-static void
-ul2user(uchar *a, ulong x)
-{
-	a[0] = x >> 24;
-	a[1] = x >> 16;
-	a[2] = x >> 8;
-	a[3] = x;
-}
-
 long
 hardread(Chan *c, void *a, long n)
 {
 	Drive *dp;
 	long rv, i;
 	uchar *aa = a;
+	Partition *pp;
 
 	if(c->qid.path == CHDIR)
-		return devdirread(c, a, n, harddir, conf.nhard*NHDIR, devgen);
+		return devdirread(c, a, n, 0, 0, hardgen);
 
 	rv = 0;
 	dp = &hard[c->qid.path & ~Qmask];
 	switch ((int)(c->qid.path & Qmask)) {
 	case Qdata:
 		for(rv = 0; rv < n; rv += i){
-			i = hardxfer(dp, Cread, aa+rv, c->offset+rv, n-rv);
+			pp = &dp->p[PART(c->qid.path)];
+			i = hardxfer(dp, pp, Cread, aa+rv, c->offset+rv, n-rv);
 			if(i <= 0)
 				break;
 		}
 		break;
-	case Qstruct:
-		if (n < 2*sizeof(ulong))
-			error(Ebadarg);
-		if (c->offset >= 2*sizeof(ulong))
-			return 0;
-		rv = 2*sizeof(ulong);
-		ul2user((uchar*)a, dp->cap);
-		ul2user((uchar*)a+sizeof(ulong), dp->bytes);
+	case Qpart:
 		break;
 	default:
 		panic("hardread: bad qid");
@@ -373,19 +328,20 @@ hardwrite(Chan *c, void *a, long n)
 	Drive *dp;
 	long rv, i;
 	uchar *aa = a;
+	Partition *pp;
 
 	rv = 0;
 	dp = &hard[c->qid.path & ~Qmask];
 	switch ((int)(c->qid.path & Qmask)) {
 	case Qdata:
 		for(rv = 0; rv < n; rv += i){
-			i = hardxfer(dp, Cwrite, aa+rv, c->offset+rv, n-rv);
+			pp = &dp->p[PART(c->qid.path)];
+			i = hardxfer(dp, pp, Cwrite, aa+rv, c->offset+rv, n-rv);
 			if(i <= 0)
 				break;
 		}
 		break;
-	case Qstruct:
-		error(Eperm);
+	case Qpart:
 		break;
 	default:
 		panic("hardwrite: bad qid");
@@ -425,7 +381,7 @@ print("cmdreadywait failed\n");
  *  parts.
  */
 static long
-hardxfer(Drive *dp, int cmd, void *va, long off, long len)
+hardxfer(Drive *dp, Partition *pp, int cmd, void *va, long off, long len)
 {
 	Controller *cp;
 	int err;
@@ -439,6 +395,9 @@ hardxfer(Drive *dp, int cmd, void *va, long off, long len)
 	if(off % dp->bytes)
 		errors("bad offset");	/* BUG - this shouldn't be a problem */
 
+print("hardxfer %ld %ld\n", off, len);
+print("hardxfer part %s %ld %ld\n", pp->name, pp->start, pp->end);
+
 	cp = dp->cp;
 	qlock(cp);
 	if(waserror()){
@@ -450,6 +409,9 @@ hardxfer(Drive *dp, int cmd, void *va, long off, long len)
 	 *  calculate the physical address of off
 	 */
 	lsec = off/dp->bytes;
+	lsec += pp->start;
+	if(lsec >= pp->end)
+		errors("xfer past end of partition\n");
 	cp->tcyl = lsec/(dp->sectors*dp->heads);
 	cp->tsec = (lsec % dp->sectors) + 1;
 	cp->thead = (lsec/dp->sectors) % dp->heads;
@@ -458,6 +420,9 @@ hardxfer(Drive *dp, int cmd, void *va, long off, long len)
 	 *  can't xfer across cylinder boundaries.
 	 */
 	lsec = (off+len)/dp->bytes;
+	lsec += pp->start;
+	if(lsec > pp->end)
+		errors("xfer past end of partition\n");
 	cyl = lsec/(dp->sectors*dp->heads);
 	if(cyl == cp->tcyl)
 		cp->len = len;
@@ -515,6 +480,7 @@ hardsetbuf(Drive *dp, int on)
 
 	cmdreadywait(cp);
 
+	cp->cmd = Csetbuf;
 	outb(cp->pbase+Pprecomp, on ? 0xAA : 0x55);
 	outb(cp->pbase+Pdh, (dp->drive<<4));
 	outb(cp->pbase+Pcmd, Csetbuf);
@@ -536,6 +502,7 @@ hardident(Drive *dp)
 	cp = dp->cp;
 	qlock(cp);
 	if(waserror()){
+print("waserror in hardident\n");
 		qunlock(cp);
 		nexterror();
 	}
@@ -566,24 +533,64 @@ print("bad disk magic\n");
 }
 
 /*
- *  read partition table
+ *  read partition table.  The partition table is just ascii strings.
  */
+#define MAGIC "plan9 partitions"
 static void
 hardpart(Drive *dp)
 {
 	Partition *pp;
-	Ptable *pt;
-	uchar buf[1024];
+	char *line[Npart+1];
+	char *field[3];
+	char buf[1024];
+	ulong n;
+	int i;
 
 	pp = &dp->p[0];
 	strcpy(pp->name, "disk");
 	pp->start = 0;
-	pp->end = pp->cap / dp->bytes;
+	pp->end = dp->cap / dp->bytes;
+	pp++;
+	strcpy(pp->name, "partition");
+	pp->start = dp->p[0].end - 1;
+	pp->end = dp->p[0].end;
+	dp->npart = 2;
 
-	qlock(dp->cp);
-	hardxfer(dp, Cread, buf, pp->end - 1, dp->bytes);
-	
-	qunlock(dp->cp);
+	if(waserror()){
+		print("error in hardpart\n");
+		nexterror();
+	}
+
+	hardxfer(dp, pp, Cread, buf, (pp->end - 1)*dp->bytes, dp->bytes);
+	buf[dp->bytes] = 0;
+
+	n = getfields(buf, line, Npart+1, '\n');
+	if(strncmp(line[0], MAGIC, sizeof(MAGIC)-1) != 0){
+		print("bad partition table 1\n");
+		goto out;
+	}
+	for(i = 1; i < n; i++){
+		pp++;
+		if(getfields(line[i], field, 3, 0) != 3){
+			print("bad partition field\n");
+			goto out;
+		}
+		if(strlen(field[0]) > NAMELEN){
+			print("bad partition name\n");
+			goto out;
+		}
+		strcpy(pp->name, field[0]);
+		pp->start = strtoul(field[1], 0, 0);
+		pp->end = strtoul(field[2], 0, 0);
+		if(pp->start > pp->end || pp->start >= dp->p[0].end){
+			print("bad partition limit\n");
+			goto out;
+		}
+print("partition %s from %d to %d\n", pp->name, pp->start, pp->end);
+		dp->npart++;
+	}
+out:
+	poperror();
 }
 
 /*
@@ -642,8 +649,12 @@ hardintr(Ureg *ur)
 			wakeup(&cp->r);
 		}
 		break;
+	case Csetbuf:
+		cp->cmd = 0;
+		wakeup(&cp->r);
+		break;
 	default:
-		print("wierd disk interrupt\n");
+		print("weird disk interrupt\n");
 		break;
 	}
 }
diff --git a/pc/trap.c b/pc/trap.c
index c8893d99c30812211c2b163806bad78a371348ea..409c93c17a09c695c640d0281ced8755e557a749 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -373,10 +373,12 @@ noted(Ureg *ur, ulong arg0)
 	|| (nur->flags&0xff00)!=(u->svflags&0xff00)){
 		pprint("bad noted ureg cs %ux ss %ux flags %ux\n", nur->cs, nur->ss,
 			nur->flags);
+    Die:
 		pexit("Suicide", 0);
 	}
 	lock(&u->p->debug);
 	if(!u->notified){
+		pprint("call to noted() when not notified\n");
 		unlock(&u->p->debug);
 		return;
 	}
@@ -385,6 +387,14 @@ noted(Ureg *ur, ulong arg0)
 	memmove(ur, u->ureg, sizeof(Ureg));
 	switch(arg0){
 	case NCONT:
+		if(waserror()){
+			pprint("suicide: trap in noted\n");
+			unlock(&u->p->debug);
+			goto Die;
+		}
+		validaddr(nur->pc, 1, 0);
+		validaddr(nur->usp, BY2WD, 0);
+		poperror();
 		unlock(&u->p->debug);
 		return;
 
diff --git a/port/devmnt.c b/port/devmnt.c
index 6ea1a63b2b3886fc6a3be5c801424d41dcf79e79..3e74e67453072c0100579bdd0a2fa7fa28a120be 100644
--- a/port/devmnt.c
+++ b/port/devmnt.c
@@ -9,7 +9,7 @@
 
 #include	"fcall.h"
 
-#define		NTAG	16384	/* 1 <= tag <= NTAG */
+#define		NTAG	65536	/*  1 <= tag < NTAG */
 
 typedef struct Mnt	Mnt;
 typedef struct Mnthdr	Mnthdr;
@@ -52,8 +52,9 @@ struct Mnthdr
 {
 	Mnthdr	*next;		/* in free list or writers list */
 	Mnthdr	*prev;		/* in writers list only */
-	short	active;
-	short	flushing;	/* a Tflush has been sent */
+	char	active;
+	char	flushing;	/* a Tflush has been sent */
+	short	seq;
 	Fcall	thdr;
 	Fcall	rhdr;
 	Rendez	r;
@@ -66,7 +67,8 @@ struct
 {
 	Lock;
 	Mnthdr	*arena;
-	Mnthdr	*free;
+	Mnthdr	*head;
+	Mnthdr	*tail;
 }mnthdralloc;
 
 struct
@@ -85,7 +87,6 @@ struct
 
 Mnt	*mnt;
 void	mntxmit(Mnt*, Mnthdr*);
-Ref	mnttag;
 
 Mntbuf*
 mballoc(void)
@@ -119,17 +120,27 @@ mbfree(Mntbuf *mb)
 }
 
 Mnthdr*
-mhalloc(void)
+mhalloc(Mnt *m)
 {
 	Mnthdr *mh;
+	int seq;
 
 loop:
 	lock(&mnthdralloc);
-	if(mh = mnthdralloc.free){		/* assign = */
-		mnthdralloc.free = mh->next;
-		mh->mbr = 0;
-		mh->thdr.tag = 1 + (incref(&mnttag) & (NTAG-1));
+	if(mh = mnthdralloc.head){		/* assign = */
+		mnthdralloc.head = mh->next;
+		if(mnthdralloc.head)
+			mnthdralloc.head->prev = 0;
+		else
+			mnthdralloc.tail = 0;
 		unlock(&mnthdralloc);
+		mh->mbr = 0;
+		seq = ++mh->seq;
+		if(seq == (1<<7)){
+			mh->seq = 1;
+			seq = 1;
+		}
+		mh->thdr.tag = (((mh-mnthdralloc.arena)<<7)|seq) & (NTAG-1);
 		return mh;
 	}
 	unlock(&mnthdralloc);
@@ -150,8 +161,13 @@ mhfree(Mnthdr *mh)
 	lock(&mnthdralloc);
 	mh->active = 0;
 	mh->thdr.tag = 0;
-	mh->next = mnthdralloc.free;
-	mnthdralloc.free = mh;
+	mh->next = 0;
+	mh->prev = mnthdralloc.tail;
+	if(mnthdralloc.tail)
+		mnthdralloc.tail->next = mh;
+	else
+		mnthdralloc.head = mh;
+	mnthdralloc.tail = mh;
 	unlock(&mnthdralloc);
 }
 
@@ -217,27 +233,39 @@ mntreset(void)
 	Mnthdr *mh;
 	MntQ *mq;
 
+	if(conf.nmnthdr > 512){
+		print("conf.nmnthdr is %d set to 512\n", conf.nmnthdr);
+		conf.nmnthdr = 512;
+	}
 	mnt = ialloc(conf.nmntdev*sizeof(Mnt), 0);
 
 	mb = ialloc(conf.nmntbuf*sizeof(Mntbuf), 0);
-	for(i=0; i<conf.nmntbuf-1; i++)
-		mb[i].next = &mb[i+1];
-	mb[i].next = 0;
 	mntbufalloc.free = mb;
+	for(i=0; i<conf.nmntbuf; i++,mb++)
+		mb->next = mb+1;
+	--mb;
+	mb->next = 0;
 
 	mh = ialloc(conf.nmnthdr*sizeof(Mnthdr), 0);
-	for(i=0; i<conf.nmnthdr-1; i++)
-		mh[i].next = &mh[i+1];
-	mh[i].next = 0;
 	mnthdralloc.arena = mh;
-	mnthdralloc.free = mh;
+	mnthdralloc.head = mh;
+	for(i=0; i<conf.nmnthdr; i++,mh++){
+		mh->seq = 0;
+		mh->next = mh+1;
+		mh->prev = mh-1;
+	}
+	--mh;
+	mnthdralloc.tail = mh;
+	mh->next = 0;
+	mnthdralloc.head->prev = 0;
 
 	mq = ialloc(conf.nmntdev*sizeof(MntQ), 0);
-	for(i=0; i<conf.nmntdev-1; i++)
-		mq[i].next = &mq[i+1];
-	mq[i].next = 0;
 	mntqalloc.arena = mq;
 	mntqalloc.free = mq;
+	for(i=0; i<conf.nmntdev; i++,mq++)
+		mq->next = mq+1;
+	--mq;
+	mq->next = 0;
 }
 
 void
@@ -302,7 +330,7 @@ mntattach(char *crud)
 
     out:
 	qunlock(&mntqalloc);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		close(c);
@@ -339,7 +367,7 @@ mntclone(Chan *c, Chan *nc)
 		}
 	}
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -377,7 +405,7 @@ mntwalk(Chan *c, char *name)
 
 	found = 1;
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	mh->thdr.type = Twalk;
 	mh->thdr.fid = c->fid;
 	strcpy(mh->thdr.name, name);
@@ -400,7 +428,7 @@ mntstat(Chan *c, char *dp)
 	Mnthdr *mh;
 
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -424,7 +452,7 @@ mntopen(Chan *c, int omode)
 	Mnthdr *mh;
 
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -449,7 +477,7 @@ mntcreate(Chan *c, char *name, int omode, ulong perm)
 	Mnthdr *mh;
 
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -477,7 +505,7 @@ mntclunk(Chan *c, int t)
 	int waserr;
 
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	mh->thdr.type = t;
 	mh->thdr.fid = c->fid;
 	waserr = 0;
@@ -519,7 +547,7 @@ mntreadwrite(Chan *c, void *vbuf, long n, int type, ulong offset)
 	buf = vbuf;
 	count = 0;
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -585,7 +613,7 @@ mntwstat(Chan *c, char *dp)
 	Mnthdr *mh;
 
 	m = mntdev(c, 0);
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		mhfree(mh);
 		nexterror();
@@ -626,7 +654,7 @@ mntflush(Mnt *m, Mnthdr *omh)	/* queue is unlocked */
 		return;
 	}
 
-	mh = mhalloc();
+	mh = mhalloc(m);
 	if(waserror()){
 		omh->flushing = 0;
 		mhfree(mh);
@@ -814,7 +842,7 @@ mntxmit(Mnt *m, Mnthdr *mh)
 		if(tag == mh->thdr.tag){	/* it's mine */
 			if(mh->rhdr.type != Rerror)
 			if(mh->rhdr.type != mh->thdr.type+1){
-				print("mail rob: '%s T(%d)%c %d %d'\n", u->p->text,
+				print("mail rob: '%s xxT(%d)%c %d %d'\n", u->p->text,
 					tag, devchar[m->q->msg->type],
 					mh->rhdr.type, mh->thdr.type+1);
 				goto FreeRead;
@@ -835,7 +863,7 @@ mntxmit(Mnt *m, Mnthdr *mh)
 		/*
 		 * Hand response to correct recipient
 		 */
-		if(tag<=0 || tag>NTAG){
+		if(tag==0 || tag>=NTAG){
 			print("unknown tag %d\n", tag);
 	FreeRead:
 			mbfree(mh->mbr);
@@ -854,7 +882,7 @@ mntxmit(Mnt *m, Mnthdr *mh)
 			goto FreeRead;
 		if(mh->rhdr.type != Rerror)
 		if(mh->rhdr.type != w->thdr.type+1){
-			print("mail rob: '%s w(%d)%c %d %d'\n",
+			print("mail rob: '%s xxw(%d)%c %d %d'\n",
 				u->p->text, tag, devchar[m->q->msg->type],
 				mh->rhdr.type, w->thdr.type+1);
 			goto FreeRead;
diff --git a/power/trap.c b/power/trap.c
index fbec0bdd2a9d0458c7d5f2b9ced2c33928e9bdce..261c37ed0bf5a942a34d0395e9a52764ec74ef49 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -426,21 +426,29 @@ noted(Ureg **urp, ulong arg0)
 	Ureg *nur;
 
 	nur = u->ureg;
-	validaddr(nur->pc, 1, 0);
-	validaddr(nur->usp, BY2WD, 0);
 	if(nur->status!=u->svstatus){
 		pprint("bad noted ureg status %lux\n", nur->status);
+    Die:
 		pexit("Suicide", 0);
 	}
 	lock(&u->p->debug);
 	if(!u->notified){
 		unlock(&u->p->debug);
-		return;
+		pprint("call to noted() when not notified\n");
+		goto Die;
 	}
 	u->notified = 0;
 	memmove(*urp, u->ureg, sizeof(Ureg));
 	switch(arg0){
 	case NCONT:
+		if(waserror()){
+			pprint("suicide: trap in noted\n");
+			unlock(&u->p->debug);
+			goto Die;
+		}
+		validaddr(nur->pc, 1, 0);
+		validaddr(nur->usp, BY2WD, 0);
+		poperror();
 		splhi();
 		unlock(&u->p->debug);
 		rfnote(urp);
diff --git a/ss/trap.c b/ss/trap.c
index 68810afcd3ab4325c0e643940af4e4f2b35202e4..5da7f57fa0abce8354c21859b030a93df9d24f03 100644
--- a/ss/trap.c
+++ b/ss/trap.c
@@ -272,21 +272,29 @@ noted(Ureg **urp, ulong arg0)
 	Ureg *nur;
 
 	nur = u->ureg;
-	validaddr(nur->pc, 1, 0);
-	validaddr(nur->usp, BY2WD, 0);
 	if(nur->psr!=u->svpsr){
 		pprint("bad noted ureg psr %lux\n", nur->psr);
+    Die:
 		pexit("Suicide", 0);
 	}
 	lock(&u->p->debug);
 	if(!u->notified){
 		unlock(&u->p->debug);
-		return;
+		pprint("call to noted() when not notified\n");
+		goto Die;
 	}
 	u->notified = 0;
 	memmove(*urp, u->ureg, sizeof(Ureg));
 	switch(arg0){
 	case NCONT:
+		if(waserror()){
+			pprint("suicide: trap in noted\n");
+			unlock(&u->p->debug);
+			goto Die;
+		}
+		validaddr(nur->pc, 1, 0);
+		validaddr(nur->usp, BY2WD, 0);
+		poperror();
 		splhi();
 		unlock(&u->p->debug);
 		rfnote(urp);