28 files changed, 106 insertions(+), 128 deletions(-)

M gnot/devduart.c
M pc/devfloppy.c
M pc/devhard.c
M pc/devlpt.c
M pc/devuart.c
M port/devarp.c
M port/devcons.c
M port/deviproute.c
M port/devmnt.c
M port/devmux.c
M port/devpipe.c
M port/devproc.c
M port/devscc.c
M port/devsrv.c
M port/devwren.c
M port/error.h
M port/fault.c
M port/portfns.h
M port/proc.c
M port/segment.c
M port/stasync.c
M port/stnoether.c
M port/stream.c
M port/sturp.c
M port/swap.c
M port/sysfile.c
M port/sysproc.c
M power/devduart.c

@@ 700,7 700,7 @@ duartopen(Chan *c, int omode)
 	}
 
 	if(dp && dp->nostream)
-		errors("in use");
+		error(Einuse);
 
 	if((c->qid.path & CHDIR) == 0)
 		streamopen(c, &duartinfo);

@@ 314,9 314,9 @@ static void
 islegal(Chan *c, long n, Drive *dp)
 {
 	if(c->offset % dp->t->bytes)
-		errors("bad offset");
+		error(Ebadarg);
 	if(n % dp->t->bytes)
-		errors("bad len");
+		error(Ebadarg);
 }
 
 /*


@@ 341,7 341,7 @@ changed(Chan *c, Drive *dp)
 	old = c->qid.vers;
 	c->qid.vers = dp->vers;
 	if(old && old!=dp->vers)
-		errors("disk changed");
+		error(Eio);
 }
 
 long


@@ 393,7 393,7 @@ floppyread(Chan *c, void *a, long n)
 				if(i != nn){
 					if(i == 0)
 						break;
-					errors("floppy read err");
+					error(Eio);
 				}
 				dp->ccyl = cyl;
 				dp->chead = head;


@@ 796,7 796,7 @@ floppyxfer(Drive *dp, int cmd, void *a, long off, long n)
 	 */
 	dp->len = n;
 	if(floppyseek(dp, off) < 0)
-		errors("seeking floppy");
+		error(Eio);
 
 /*print("tcyl %d, thead %d, tsec %d, addr %lux, n %d\n",
 	dp->tcyl, dp->thead, dp->tsec, a, dp->len);/**/


@@ 823,7 823,7 @@ floppyxfer(Drive *dp, int cmd, void *a, long off, long n)
 	if(floppycmd() < 0){
 		spllo();
 		print("xfer cmd failed\n");
-		errors("floppy command failed");
+		error(Eio);
 	}
 
 	/*


@@ 838,14 838,14 @@ floppyxfer(Drive *dp, int cmd, void *a, long off, long n)
 	if(fl.nstat < 7){
 		print("xfer result failed %lux\n", inb(Pmsr));
 		fl.confused = 1;
-		errors("floppy result failed");
+		error(Eio);
 	}
 	if((fl.stat[0] & Codemask)!=0 || fl.stat[1] || fl.stat[2]){
 		print("xfer failed %lux %lux %lux\n", fl.stat[0],
 			fl.stat[1], fl.stat[2]);
 		print("offset %lud len %d\n", off, dp->len);
 		dp->confused = 1;
-		errors("floppy drive lost");
+		error(Eio);
 	}
 
 	/*


@@ 856,7 856,7 @@ floppyxfer(Drive *dp, int cmd, void *a, long off, long n)
 	offset = offset * c2b[fl.stat[6]];
 	if(offset != off+dp->len){
 		dp->confused = 1;
-		errors("floppy drive lost");
+		error(Eio);
 	}
 
 	dp->lasttouched = m->ticks;

@@ 239,7 239,7 @@ hardattach(char *spec)
 				break;
 			default:
 				print("unknown hard disk type\n");
-				errors("unknown hard disk type");
+				error(Egreg);
 			}
 			dp->bytes = 512;
 			dp->cap = dp->bytes * dp->cyl * dp->heads * dp->sectors;


@@ 349,7 349,7 @@ hardwrite(Chan *c, void *a, long n)
 	Controller *cp;
 
 	if(c->qid.path == CHDIR)
-		errors("can't write directory");
+		error(Eisdir);
 
 	dp = &hard[DRIVE(c->qid.path)];
 	pp = &dp->p[PART(c->qid.path)];


@@ 432,7 432,7 @@ cmdreadywait(Controller *cp)
 	while((inb(cp->pbase+Pstatus) & (Sready|Sbusy)) != Sready)
 		if(TK2MS(m->ticks - start) > 1){
 print("cmdreadywait failed\n");
-			errors("disk not responding");
+			error(Eio);
 		}
 }
 


@@ 450,7 450,7 @@ hardxfer(Drive *dp, Partition *pp, int cmd, long start, long len)
 	int loop;
 
 	if(dp->online == 0)
-		errors("disk offline");
+		error(Eio);
 
 	/*
 	 *  cut transfer size down to disk buffer size


@@ 510,7 510,7 @@ print("\tnsecs %d, sofar %d\n", cp->nsecs, cp->sofar);/**/
 print("hd%d err: status %lux, err %lux\n", dp-hard, cp->status, cp->error);
 print("\ttcyl %d, tsec %d, thead %d\n", cp->tcyl, cp->tsec, cp->thead);
 print("\tnsecs %d, sofar %d\n", cp->nsecs, cp->sofar);
-		errors("disk I/O error");
+		error(Eio);
 	}
 
 	return cp->nsecs*dp->bytes;


@@ 569,7 569,7 @@ hardident(Drive *dp)
 	sleep(&cp->r, cmddone, cp);
 	if(cp->status & Serr){
 		print("bad disk ident status\n");
-		errors("disk I/O error");
+		error(Eio);
 	}
 	memmove(&dp->id, cp->buf, dp->bytes);
 

@@ 88,7 88,7 @@ lptattach(char *spec)
 	int i  = (spec && *spec) ? strtol(spec, 0, 0) : 1;
 
 	if(i < 1 || i > NDEV)
-		errors("spec out of range");
+		error(Ebadarg);
 	c = devattach('L', spec);
 	c->dev = i-1;
 	return c;

@@ 655,7 655,7 @@ uartopen(Chan *c, int omode)
 	}
 
 	if(up && up->nostream)
-		errors("in use");
+		error(Einuse);
 
 	if((c->qid.path & CHDIR) == 0)
 		streamopen(c, &uartinfo);

@@ 244,7 244,7 @@ arpwrite(Chan *c, char *a, long n, ulong offset)
 				error(Ebadarg);
 
 			if(arpdelete(field[1]) < 0)
-				error(Ebadaddr);
+				error(Enetaddr);
 		}
 	case arpdataqid:
 		if(n != sizeof(Arpentry))

@@ 818,7 818,7 @@ conswrite(Chan *c, void *va, long n, ulong offset)
 			error(Ebadarg);
 		decrypt(evekey, a, n);
 		if(memcmp(u->p->pgrp->crypt->chal, a, 8) != 0)
-			error(Eauth);
+			error(Eperm);
 		strncpy(u->p->user, a+8, NAMELEN);
 		u->p->user[NAMELEN-1] = '\0';
 		memmove(u->p->pgrp->crypt->key, a+NAMELEN+DESKEYLEN, DESKEYLEN);

@@ 97,7 97,7 @@ ipaddroute(ulong dst, ulong mask, ulong gate)
 	 *  filter out impossible requests
 	 */
 	if((dst&mask) != dst)
-		error(Ebadaddr);
+		error(Enetaddr);
 
 	/*
 	 *  see if we already have a route for


@@ 118,7 118,7 @@ ipaddroute(ulong dst, ulong mask, ulong gate)
 	}
 	if(free == 0){
 		unlock(&iprtab);
-		error(Enoroute);
+		exhausted("routes");
 	}
 
 	/*

@@ 143,7 143,7 @@ mntattach(char *muxattach)
 	lock(&mntalloc);
 	if(mntalloc.mntfree == 0) {
 		unlock(&mntalloc);
-		error(Enomntdev);
+		exhausted("mount devices");
 	}
 	m = mntalloc.mntfree;
 	mntalloc.mntfree = m->list;	

@@ 275,7 275,7 @@ muxcreate(Chan *c, char *name, int omode, ulong perm)
 	}
 
 	if(m == e)
-		error(Enomux);
+		exhausted("multiplexers");
 
 	strncpy(m->name, name, NAMELEN);
 	strncpy(m->user, u->p->user, NAMELEN);


@@ 610,7 610,7 @@ muxreadq(Mux *m, Dtq *q, char *va, ulong n)
 	while(!havedata(q)) {
 		sleep(&q->r, havedata, q);
 		if(m->headopen == 0)
-			errors(Emuxshutdown);
+			error(Emuxshutdown);
 	}
 
 	nread = 0;

@@ 79,7 79,7 @@ pipeattach(char *spec)
 	if(pipealloc.free == 0){
 		unlock(&pipealloc);
 		close(c);
-		error(Enopipe);
+		exhausted("pipes");
 	}
 	p = pipealloc.free;
 	pipealloc.free = p->next;

@@ 174,7 174,7 @@ procopen(Chan *c, int omode)
 		c->pgrpid.vers = pg->pgrpid;
 		break;
 	default:
-		pprint("unknown qid in devopen\n");
+		pprint("procopen %lux\n", c->qid);
 		error(Egreg);
 	}
 


@@ 349,7 349,7 @@ procread(Chan *c, void *va, long n, ulong offset)
 		if(offset+n > j)
 			n = j-offset;
 		if(n == 0 && offset == 0)
-			errors("no segments");
+			exhausted("segments");
 		memmove(a, &statbuf[offset], n);
 		return n;
 	}


@@ 392,7 392,7 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 	switch(QID(c->qid)){
 	case Qmem:
 		if(p->state != Stopped)
-			errors("not stopped");
+			error(Ebadctl);
 
 		if(offset >= USERADDR && offset <= USERADDR+BY2PG-1) {
 			pg = p->upage;


@@ 411,7 411,7 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 			ur = pxu->dbgreg;
 			if(offset < (ulong)ur || hi > (ulong)ur+sizeof(Ureg)) {
 				kunmap(k);
-				errors("bad u-area address");
+				error(Ebadarg);
 			}
 			ur = (Ureg*)(b+((ulong)ur-USERADDR));
 			setregisters(ur, b+(offset-USERADDR), a, n);


@@ 427,7 427,7 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 
 	case Qnote:
 		if(p->kp)
-			errors("can't note kproc");
+			error(Eperm);
 		k = kmap(p->upage);
 		up = (User*)VA(k);
 		if(up->p != p){


@@ 441,7 441,7 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 		memmove(buf, va, n);
 		buf[n] = 0;
 		if(!postnote(p, 0, buf, NUser))
-			error(Enonote);
+			exhausted("notes");
 		break;
 
 	default:


@@ 462,7 462,7 @@ proctext(Chan *c, Proc *p)
 
 	s = p->seg[TSEG];
 	if(s == 0)
-		errors("no text segment");
+		error(Enonexist);
 	if(p->state==Dead)
 		error(Eprocdied);
 


@@ 524,7 524,7 @@ procstopwait(Proc *p, int ctl)
 	int pid;
 
 	if(p->pdbg)
-		errors("debugged already");
+		error(Einuse);
 	if(procstopped(p))
 		return;
 


@@ 573,14 573,14 @@ procctlreq(Proc *p, char *va, int n)
 		procstopwait(p, 0);
 	else if(strncmp(buf, "startstop", 9) == 0) {
 		if(p->state != Stopped)
-			errors("not stopped");
+			error(Ebadctl);
 		p->procctl = Proc_traceme;
 		ready(p);
 		procstopwait(p, Proc_traceme);
 	}
 	else if(strncmp(buf, "start", 5) == 0) {
 		if(p->state != Stopped)
-			errors("not stopped");
+			error(Ebadctl);
 		ready(p);
 	}
 	else


@@ 607,7 607,7 @@ procctlmemio(Proc *p, ulong offset, int n, void *va, int read)
 	for(;;) {
 		s = seg(p, offset, 1);
 		if(s == 0)
-			errors("not in address space");
+			error(Ebadarg);
 
 		if(offset+n >= s->top)
 			n = s->top-offset;

@@ 149,7 149,7 @@ sccsetbaud(SCC *sp, int rate)
 	int brconst;
 
 	if(rate == 0)
-		errors("bad baud rate");
+		error(Ebadctl);
 
 	brconst = (sp->freq+16*rate-1)/(2*16*rate) - 2;
 


@@ 631,7 631,7 @@ sccopen(Chan *c, int omode)
 	if(c->qid.path != CHDIR){
 		sp = scc[STREAMID(c->qid.path)];
 		if(sp->nostream)
-			errors("in use");
+			error(Einuse);
 		streamopen(c, &sccinfo);
 	}
 	return devopen(c, omode, sccdir, 2*nscc, devgen);


@@ 667,7 667,7 @@ sccread(Chan *c, void *buf, long n, ulong offset)
 		sprint(b, "%d", STREAMID(c->qid.path));
 		return stringread(buf, n, b, offset);
 	}
-	errors("bad qid");
+	error(Egreg);
 }
 
 long

@@ 124,7 124,7 @@ srvcreate(Chan *c, char *name, int omode, ulong perm)
 			error(Einuse);
 	}
 	if(j == -1)
-		error(Enosrv);
+		exhausted("server slots");
 	sp = &srv[j];
 	sp->chan = c;
 	unlock(&srvlk);

@@ 55,12 55,12 @@ wrendev(char *p)
 	if(p == 0 || p[0] == '\0')
 		return 0;
 	if(p[0] < '0' || p[0] > '7')
-		errors("bad scsi drive specifier");
+		error(Ebadarg);
 	drive = p[0] - '0';
 	unit = 0;
 	if(p[1]){
 		if(p[1] != '.' || p[2] < '0' || p[2] > '7' || p[3] != '\0')
-			errors("bad scsi unit specifier");
+			error(Ebadarg);
 		unit = p[2] - '0';
 	}
 	return (drive << 3) | unit;


@@ 197,8 197,8 @@ wrenio(Chan *c, int write, char *a, ulong len, ulong offset)
 	ulong block, n, max, x;
 
 	d = &wren[DRIVE(c->qid.path)];
-	if(d->npart == 0)
-		errors("drive repartitioned");
+	if(d->npart == 0)			/* drive repartitioned */
+		error(Eio);
 	p = &d->p[PART(c->qid.path)];
 
 	block = offset / d->bytes + p->start;

@@ 4,7 4,6 @@ extern char Eunmount[];		/* not mounted */
 extern char Eunion[];		/* not in union */
 extern char Emountrpc[];	/* mount rpc error */
 extern char Eshutdown[];	/* mounted device shut down */
-extern char Enomntdev[];	/* no free mount devices */
 extern char Enocreate[];	/* mounted directory forbids creation */
 extern char Enonexist[];	/* file does not exist */
 extern char Ebadsharp[];	/* unknown device in # filename */


@@ 25,13 24,11 @@ extern char Enobitmap[];	/* out of bitmap descriptors */
 extern char Enobitstore[];	/* out of bitmap storage */
 extern char Ebadfont[];		/* unallocated font */
 extern char Enofont[];		/* no free font descriptors */
-extern char Eauth[];		/* authentication failure */
-extern char Ebadaddr[];		/* bad network address */
+extern char Enetaddr[];		/* bad network address */
 extern char Emsgsize[];		/* message is too big for protocol */
 extern char Enetbusy[];		/* network device is busy or allocated */
 extern char Enoproto[];		/* network protocol not supported */
 extern char Enoport[];		/* network port not available */
-extern char Enoroute[];		/* no free routes */
 extern char Enoifc[];		/* bad interface or no free interface slots */
 extern char Enolisten[];	/* not announced */
 extern char Ehungup[];		/* write to hungup stream */


@@ 40,38 37,17 @@ extern char Enodev[];		/* no free devices */
 extern char Enoenv[];		/* no free environment resources */
 extern char Emuxshutdown[];	/* mux server shut down */
 extern char Emuxbusy[];		/* all mux channels busy */
-extern char Enomux[];		/* no free multiplexers */
 extern char Emuxmsg[];		/* bad mux message format or mismatch */
-extern char Enopipe[];		/* no free pipes */
-
-extern char Enofd[];		/* no free file descriptors */
-extern char Ebadfd[];		/* fd out of range or not open */
-extern char Ebadexec[];		/* a.out header invalid */
-extern char Eioload[];		/* i/o error in demand load */
-extern char Enochild[];		/* no living children */
-extern char Enoseg[];		/* no free segments */
-extern char Ebadmount[];	/* inconsistent mount */
-extern char Ebaddirread[];	/* directory read not quantized */
-extern char Esegaddr[];		/* illegal segment addresses or size */
 extern char Eprocdied[];	/* process exited */
-extern char Enosrv[];		/* no free server slots */
-extern char Enoqueue[];		/* no free stream queues */
-extern char Ebadld[];		/* illegal line discipline */
-extern char Enostream[];	/* no free stream heads */
-extern char Ebadnet[];		/* illegal network address */
-extern char Enonote[];		/* note overflow */
-extern char Eintr[];		/* interrupted */
-extern char Edestbusy[];	/* datakit destination busy */
-extern char Edestotl[];		/* datakit destination out to lunch */
-extern char Enetotl[];		/* datakit controller out to lunch */
-extern char Erejected[];	/* datakit destination rejected call */
-extern char Ebadcnt[];		/* read count greater than requested */
+extern char Enochild[];		/* no living children */
+extern char Eioload[];		/* i/o error in demand load */
 extern char Enovmem[];		/* virtual memory allocation failed */
-extern char Enoasync[];		/* out of async stream modules */
-extern char Enetunreach[];	/* network unreachable */
+extern char Ebadld[];		/* illegal line discipline */
+extern char Ebadfd[];		/* fd out of range or not open */
+extern char Eisstream[];	/* seek on a stream */
+extern char Ebadexec[];		/* a.out header invalid */
 extern char Etimedout[];	/* connection timed out */
 extern char Econrefused[];	/* connection refused */
-extern char Eprotonosup[];	/* operation not supported by network protocol */
-extern char Eisstream[];	/* seek on a stream */
-extern char Enofilsys[];	/* out of filsys resources */
+extern char Enetunreach[];	/* network unreachable */
+extern char Eintr[];		/* interrupted */
 extern char Egreg[];		/* it's a thermal problem */

@@ 8,7 8,7 @@
 
 #define DPRINT
 
-void	faultexit(char*);
+void	faulterror(char*);
 
 int
 fault(ulong addr, int read)


@@ 190,7 190,7 @@ pio(Segment *s, ulong addr, ulong soff, Page **p)
 			qunlock(&c->rdl);
 			kunmap(k);
 			putpage(new);
-			faultexit("sys: demand load I/O error");
+			faulterror("sys: demand load I/O error");
 		}
 
 		ask = s->flen-soff;


@@ 224,7 224,7 @@ pio(Segment *s, ulong addr, ulong soff, Page **p)
 			putpage(new);
 			qlock(&s->lk);
 			qunlock(&s->lk);
-			faultexit("sys: page in I/O error");
+			faulterror("sys: page in I/O error");
 		}
 
 		n = (*devtab[c->type].read)(c, kaddr, BY2PG, daddr);


@@ 248,11 248,11 @@ pio(Segment *s, ulong addr, ulong soff, Page **p)
 }
 
 void
-faultexit(char *s)
+faulterror(char *s)
 {
 	if(u->nerrlab) {
 		postnote(u->p, 1, s, NDebug);
-		errors(s);
+		error(s);
 	}
 	pexit(s, 0);
 }

@@ 59,9 59,9 @@ void	envpgclose(Env*);
 void	envpgcopy(Env*, Env*);
 int	eqchan(Chan*, Chan*, long);
 int	eqqid(Qid, Qid);
-void	error(char []);
-void	errors(char*);
+void	error(char*);
 long	execregs(ulong, ulong, ulong);
+void	exhausted(char*);
 void	exit(void);
 Block*	expandb(Block *, int);
 int	fault(ulong, int);

@@ 390,7 390,7 @@ postnote(Proc *p, int dolock, char *n, int flag)
 	if(p->upage == 0){
 		if(dolock)
 			qunlock(&p->debug);
-		errors("noted process disappeared");
+		error(Eprocdied);
 	}
 
 	SET(k);


@@ 771,16 771,18 @@ error(char err[])
 }
 
 void
-errors(char *err)
+nexterror(void)
 {
-	strncpy(u->error, err, ERRLEN);
-	nexterror();
+	gotolabel(&u->errlab[--u->nerrlab]);
 }
 
 void
-nexterror(void)
+exhausted(char *resource)
 {
-	gotolabel(&u->errlab[--u->nerrlab]);
+	char buf[ERRLEN];
+
+	sprint(buf, "no free %s", resource);
+	error(buf);
 }
 
 Waitq *

@@ 57,7 57,7 @@ newseg(int type, ulong base, ulong size)
 	Segment *s;
 
 	if(size > (SEGMAPSIZE*PTEPERTAB))
-		errors("segment too large");
+		error(Enovmem);
 
 	for(;;) {
 		lock(&segalloc);


@@ 335,7 335,7 @@ ibrk(ulong addr, int seg)
 
 	s = u->p->seg[seg];
 	if(s == 0)
-		errors("no segment");
+		error(Ebadarg);
 
 	if(addr == 0)
 		return s->base;


@@ 346,7 346,7 @@ ibrk(ulong addr, int seg)
 		/* We may start with the bss overlapping the data */
 		if(seg != BSEG || u->p->seg[DSEG] == 0 || addr < u->p->seg[DSEG]->base) {
 			qunlock(&s->lk);
-			errors("addr below segment");
+			error(Enovmem);
 		}
 		addr = s->base;
 	}


@@ 371,7 371,7 @@ ibrk(ulong addr, int seg)
 		if(newtop >= ns->base && newtop < ns->top) {
 			qunlock(&s->lk);
 			pprint("segments overlap\n");
-			error(Esegaddr);
+			error(Enovmem);
 		}
 	}
 


@@ 424,7 424,7 @@ segattach(Proc *p, ulong attr, char *name, ulong va, ulong len)
 
 	USED(p);
 	if(va&KZERO)					/* BUG: Only ok for now */
-		errors("bad virtual address");
+		error(Ebadarg);
 
 	validaddr((ulong)name, 1, 0);
 	vmemchr(name, 0, ~0);


@@ 434,7 434,7 @@ segattach(Proc *p, ulong attr, char *name, ulong va, ulong len)
 			break;
 
 	if(sno == NSEG)
-		errors("no per process segments");
+		error(Enovmem);
 
 	va = va&~(BY2PG-1);
 	len = PGROUND(len);


@@ 445,17 445,17 @@ segattach(Proc *p, ulong attr, char *name, ulong va, ulong len)
 			continue;	
 		if((newtop > ns->base && newtop <= ns->top) ||
 		   (va >= ns->base && va < ns->top))
-			errors("segments overlap");
+			error(Enovmem);
 	}
 
 	for(ps = physseg; ps->name; ps++)
 		if(strcmp(name, ps->name) == 0)
 			goto found;
 
-	errors("bad segment name");
+	error(Ebadarg);
 found:
 	if(len > ps->size)
-		errors("segment too long");
+		error(Enovmem);
 
 	attr &= ~SG_TYPE;			/* Turn off what we are not allowed */
 	attr |= ps->attr;			/* Copy in defaults */


@@ 480,7 480,7 @@ syssegflush(ulong *arg)
 
 	s = seg(u->p, arg[0], 1);
 	if(s == 0)
-		errors("bad segment address");
+		error(Ebadarg);
 
 	s->flushme = 1;
 

@@ 113,7 113,7 @@ asyncopen(Queue *q, Stream *s)
 		qunlock(ap);
 	}
 	if(ap == &async[conf.nasync])
-		error(Enoasync);
+		exhausted("async stream modules");
 	q->ptr = q->other->ptr = ap;
 
 	ap->inuse = 1;

@@ 265,7 265,7 @@ etherparse(uchar *to, char *from)
 	if(strchr(from, '.')) {
 		ip = ipparse(from);
 		if(ip == 0)
-			error(Ebadnet);
+			error(Enetaddr);
 
 		hnputl(nip, ip);			
 		if(arp_lookup(nip, to))


@@ 274,7 274,7 @@ etherparse(uchar *to, char *from)
 #endif
 
 	if(strlen(from) != 12)
-		error(Ebadnet);
+		error(Enetaddr);
 
 	for(i = 0; i < 6; i++){
 		fdig = (*from++)&0x7f;

@@ 296,7 296,7 @@ allocq(Qinfo *qi)
 
 	if(q == &qlist[conf.nqueue]){
 		print("no more queues\n");
-		error(Enoqueue);
+		exhausted("queues");
 	}
 
 	q->flag = QINUSE;


@@ 820,7 820,7 @@ streamnew(ushort type, ushort dev, ushort id, Qinfo *qi, int noopen)
 	}
 	if(s == &slist[conf.nstream]){
 		print("no more streams\n");
-		error(Enostream);
+		exhausted("streams");
 	}
 	if(waserror()){
 		qunlock(s);


@@ 1159,7 1159,7 @@ streamread(Chan *c, void *vbuf, long n)
 		if(bp == 0){
 			if(q->flag & QHUNGUP){
 				if(s->err)
-					errors((char*)s->err->rptr);
+					error((char*)s->err->rptr);
 				else if(s->hread++<3)
 					break;
 				else


@@ 1217,7 1217,7 @@ qlook(Stream *s, char *name)
 		if(q == s->devq->other)
 			break;
 	}
-	errors("not found");
+	error(Ebadarg);
 }
 
 /*


@@ 1322,7 1322,7 @@ streamwrite(Chan *c, void *a, long n, int docopy)
 	q = s->procq;
 	if(q->other->flag & QHUNGUP){
 		if(s->err)
-			errors((char*)(s->err->rptr));
+			error((char*)(s->err->rptr));
 		else
 			error(Ehungup);
 	}

@@ 167,7 167,7 @@ urpopen(Queue *q, Stream *s)
 	if(up == &urp[conf.nurp]){
 		q->ptr = 0;
 		WR(q)->ptr = 0;
-		errors("out of urp structures");
+		exhausted("urp structures");
 	}
 
 	q->ptr = q->other->ptr = up;

@@ 330,7 330,7 @@ setswapchan(Chan *c)
 {
 	if(swapimage.c) {
 		if(swapalloc.free != conf.nswap)
-			errors("swap channel busy");
+			error(Einuse);
 		close(swapimage.c);
 	}
 	incref(c);

@@ 26,7 26,7 @@ newfd(Chan *c)
 			return i;
 		}
 	unlock(f);
-	error(Enofd);
+	exhausted("file descriptors");
 }
 
 Chan*


@@ 38,7 38,7 @@ fdtochan(int fd, int mode, int chkmnt)
 	if(fd<0 || NFD<=fd || (c = u->p->fgrp->fd[fd])==0)
 		error(Ebadfd);
 	if(chkmnt && (c->flag&CMSG))
-		errors("channel is mounted");
+		error(Ebadusefd);
 	if(mode<0 || c->mode==ORDWR)
 		return c;
 	if((mode&OTRUNC) && c->mode==OREAD)


@@ 262,7 262,7 @@ sysread(ulong *arg)
 	if(c->qid.path & CHDIR){
 		n -= n%DIRLEN;
 		if(c->offset%DIRLEN || n==0)
-			error(Ebaddirread);
+			error(Etoosmall);
 	}
 	if((c->qid.path&CHDIR) && c->mnt)
 		n = unionread(c, (void*)arg[1], n);


@@ 426,9 426,9 @@ bindmount(ulong *arg, int ismount)
 		nexterror();
 	}
 	if((c0->qid.path^c1->qid.path) & CHDIR)
-		error(Ebadmount);
+		error(Emount);
 	if(flag && !(c0->qid.path&CHDIR))
-		error(Ebadmount);
+		error(Emount);
 	ret = mount(c0, c1, flag);
 	poperror();
 	close(c1);

@@ 259,7 259,7 @@ sysexec(ulong *arg)
 	 * Build the stack segment, putting it in kernel virtual for the moment
 	 */
 	if(spage > TSTKSIZ)
-		errors("too many arguments");
+		error(Enovmem);
 
 	 
 	p->seg[ESEG] = newseg(SG_STACK, TSTKTOP-USTKSIZE, USTKSIZE/BY2PG);


@@ 528,14 528,14 @@ syssegbrk(ulong *arg)
 				switch(s->type&SG_TYPE) {
 				case SG_TEXT:
 				case SG_DATA:
-					errors("bad segment type");
+					error(Ebadarg);
 				default:
 					return ibrk(arg[1], i);
 				}
 			}
 		}
 
-	errors("not in address space");
+	error(Ebadarg);
 }
 
 long


@@ 560,12 560,12 @@ syssegdetach(ulong *arg)
 			qunlock(&s->lk);
 		}
 
-	errors("not in address space");
+	error(Ebadarg);
 
 found:
 	if((ulong)arg >= s->base && (ulong)arg < s->top) {
 		qunlock(&s->lk);
-		errors("illegal address");
+		error(Ebadarg);
 	}
 	u->p->seg[i] = 0;
 	qunlock(&s->lk);


@@ 585,13 585,13 @@ syssegfree(ulong *arg)
 	from = PGROUND(arg[0]);
 	s = seg(u->p, from, 1);
 	if(s == 0)
-		errors("not in address space");
+		error(Ebadarg);
 
 	pages = (arg[1]+BY2PG-1)/BY2PG;
 
 	if(from+pages*BY2PG > s->top) {
 		qunlock(&s->lk);
-		errors("segment too short");
+		error(Ebadarg);
 	}
 
 	mfreeseg(s, from, pages);

@@ 232,7 232,7 @@ duartbaud(Duartport *dp, int b)
 		x = BD300;
 		break;
 	default:
-		errors("bad baud rate");
+		error(Ebadarg);
 	}
 	if(x & 0x0100)
 		dp->duart->ipc_acr = duartacr |= 0x80;


@@ 770,7 770,7 @@ duartopen(Chan *c, int omode)
 	}
 
 	if(dp && dp->nostream)
-		errors("in use");
+		error(Einuse);
 
 	if((c->qid.path & CHDIR) == 0)
 		streamopen(c, &duartinfo);


@@ 814,7 814,7 @@ duartread(Chan *c, void *buf, long n, ulong offset)
 		return 1;
 	}
 
-	errors("no such duart type");
+	error(Egreg);
 }
 
 long


@@ 827,14 827,14 @@ void
 duartremove(Chan *c)
 {
 	USED(c);
-	errors("can't remove a duart");
+	error(Eperm);
 }
 
 void
 duartwstat(Chan *c, char *dp)
 {
 	USED(c);
-	errors("can't write a duart");
+	error(Eperm);
 }
 
 int