From 6273cbe67c9ce18f092a478d1c2b36ffcf33e786 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 28 May 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-05-28

---
 bitsy/devuda1341.c | 63 ++++++++++++++++++++++++----------------------
 port/devdraw.c     |  4 ++-
 port/error.h       |  1 +
 port/sysfile.c     | 10 ++++++--
 4 files changed, 45 insertions(+), 33 deletions(-)

diff --git a/bitsy/devuda1341.c b/bitsy/devuda1341.c
index ea00beed9e05a664a628ce361823b1d366316769..3a9605c17133cfa189f5ac703778195684394c64 100644
--- a/bitsy/devuda1341.c
+++ b/bitsy/devuda1341.c
@@ -10,6 +10,7 @@
  *
  *	The interface should be identical to that of devaudio.c
  */
+
 #include	"u.h"
 #include	"../port/lib.h"
 #include	"mem.h"
@@ -149,6 +150,7 @@ enum {
 Dirtab
 audiodir[] =
 {
+	".",		{Qdir, 0, QTDIR},	0,	DMDIR|0555,
 	"audio",	{Qaudio},			0,	0666,
 	"volume",	{Qvolume},		0,	0666,
 	"speed",	{Qspeed},			0,	0666,
@@ -766,27 +768,29 @@ sendaudio(IOstate *s) {
 		return;
 	}
 	while (s->next != s->filling) {
-		assert(s->next->nbytes);
-		if ((n = dmastart(s->dma, s->next->phys, s->next->nbytes)) == 0) {
-			iostats.faildma++;
-			break;
-		}
-		iostats.totaldma++;
-		switch (n >> 8) {
-		case 1:
-			iostats.idledma++;
-			break;
-		case 3:
-			iostats.faildma++;
-			break;
-		}
-		if (debug) {
-			if (debug > 1)
-				print("dmastart @%p\n", s->next);
-			else
-				iprint("+");
+		s->next->nbytes &= ~0x3;	/* must be a multiple of 4 */
+		if(s->next->nbytes) {
+			if ((n = dmastart(s->dma, s->next->phys, s->next->nbytes)) == 0) {
+				iostats.faildma++;
+				break;
+			}
+			iostats.totaldma++;
+			switch (n >> 8) {
+			case 1:
+				iostats.idledma++;
+				break;
+			case 3:
+				iostats.faildma++;
+				break;
+			}
+			if (debug) {
+				if (debug > 1)
+					print("dmastart @%p\n", s->next);
+				else
+					iprint("+");
+			}
+			s->next->nbytes = 0;
 		}
-		s->next->nbytes = 0;
 		s->next++;
 		if (s->next == &s->buf[Nbuf])
 			s->next = &s->buf[0];
@@ -901,15 +905,15 @@ audioattach(char *param)
 }
 
 static int
-audiowalk(Chan *c, char *name)
+audiowalk(Chan *c, Chan *nc, char **name, int nname)
 {
-	return devwalk(c, name, audiodir, nelem(audiodir), devgen);
+	return devwalk(c, nc, name, nname, audiodir, nelem(audiodir), devgen);
 }
 
-static void
-audiostat(Chan *c, char *db)
+static int
+audiostat(Chan *c, uchar *db, int n)
 {
-	devstat(c, db, audiodir, nelem(audiodir), devgen);
+	return devstat(c, db, n, audiodir, nelem(audiodir), devgen);
 }
 
 static Chan*
@@ -918,7 +922,7 @@ audioopen(Chan *c, int mode)
 	IOstate *s;
 	int omode = mode;
 
-	switch(c->qid.path & ~CHDIR) {
+	switch((ulong)c->qid.path) {
 	default:
 		error(Eperm);
 		break;
@@ -986,7 +990,7 @@ audioclose(Chan *c)
 {
 	IOstate *s;
 
-	switch(c->qid.path & ~CHDIR) {
+	switch((ulong)c->qid.path) {
 	default:
 		error(Eperm);
 		break;
@@ -1074,7 +1078,7 @@ audioread(Chan *c, void *v, long n, vlong off)
 
 	n0 = n;
 	p = v;
-	switch(c->qid.path & ~CHDIR) {
+	switch((ulong)c->qid.path) {
 	default:
 		error(Eperm);
 		break;
@@ -1212,7 +1216,7 @@ audiowrite(Chan *c, void *vp, long n, vlong)
 
 	p = vp;
 	n0 = n;
-	switch(c->qid.path & ~CHDIR) {
+	switch((ulong)c->qid.path) {
 	default:
 		error(Eperm);
 		break;
@@ -1373,7 +1377,6 @@ Dev uda1341devtab = {
 	devreset,
 	audioinit,
 	audioattach,
-	devclone,
 	audiowalk,
 	audiostat,
 	audioopen,
diff --git a/port/devdraw.c b/port/devdraw.c
index c40f29217d91f6fef5f48af98be003356ab97a58..919af85653826c100a7a17bfddeec7152aad647c 100644
--- a/port/devdraw.c
+++ b/port/devdraw.c
@@ -1509,8 +1509,10 @@ drawmesg(Client *client, void *av, int n)
 				error(Enodrawimage);
 			if(font->image->layer)
 				error("can't use window as font");
-			free(font->fchar);	/* should we complain if non-zero? */
 			ni = BGLONG(a+5);
+			if(ni<=0 || ni>4096)
+				error("bad font size (4096 chars max)");
+			free(font->fchar);	/* should we complain if non-zero? */
 			font->fchar = malloc(ni*sizeof(FChar));
 			if(font->fchar == 0)
 				error("no memory for font");
diff --git a/port/error.h b/port/error.h
index 877fdfc39e1fe63311d46ea04c38838a57647a7c..5e571b947ff2cd9233a24e83fef454d0edd3b22b 100644
--- a/port/error.h
+++ b/port/error.h
@@ -46,3 +46,4 @@ extern char Enoreg[];		/* process has no saved registers */
 extern char Enoattach[];	/* mount/attach disallowed */
 extern char Eshortstat[];	/* stat buffer too small */
 extern char Ebadstat[];		/* malformed stat buffer */
+extern char Enegoff[];	/* negative i/o offset */
diff --git a/port/sysfile.c b/port/sysfile.c
index 3a62c9d24864d274f27740ede39b49e12d4768e2..17a7c4a29e28467dae525c931591644f31331aa2 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -363,7 +363,7 @@ read(ulong *arg, uvlong *offp)
 	int dir;
 	long n;
 	Chan *c;
-	uvlong off;
+	vlong off;
 
 	n = arg[2];
 	validaddr(arg[1], n, 1);
@@ -385,6 +385,9 @@ read(ulong *arg, uvlong *offp)
 	else
 		off = *offp;
 
+	if(off < 0)
+		error(Enegoff);
+
 	if(dir && c->umh)
 		n = unionread(c, (void*)arg[1], n);
 	else
@@ -430,7 +433,7 @@ write(ulong *arg, uvlong *offp)
 {
 	Chan *c;
 	long m, n;
-	uvlong off;
+	vlong off;
 
 	validaddr(arg[1], arg[2], 0);
 	n = 0;
@@ -458,6 +461,9 @@ write(ulong *arg, uvlong *offp)
 	}else
 		off = *offp;
 
+	if(off < 0)
+		error(Enegoff);
+
 	m = devtab[c->type]->write(c, (void*)arg[1], n, off);
 
 	if(offp == nil && m < n){