git: 9front

Download patch

ref: 50b5ed42a484cc88f24aa68c1ee35cf3e3d0ea46
parent: 1be6cab37d30ccde1dcedec776b8381115b65610
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sat Sep 8 18:24:36 EDT 2018 

devarch: fix /dev/msr (thanks joe9, aiju)

the end condition port < offset+n could never become
false when offset truncated to 32 bit signed port is
negative. change the condition variables to unsigned
int.

msr's are not byte addressible, so advance reads by
one instead of 8.


--- a/sys/src/9/pc/devarch.c
+++ b/sys/src/9/pc/devarch.c
@@ -355,7 +355,8 @@
 archread(Chan *c, void *a, long n, vlong offset)
 {
 	char buf[32], *p;
-	int port, i;
+	uint port, end;
+	int i;
 	ushort *sp;
 	ulong *lp;
 	vlong *vp;
@@ -362,14 +363,15 @@
 	IOMap *m;
 	Rdwrfn *fn;
 
+	port = offset;
+	end = port+n;
 	switch((ulong)c->qid.path){
 	case Qdir:
 		return devdirread(c, a, n, archdir, narchdir, devgen);
 
 	case Qiob:
-		port = offset;
-		checkport(offset, offset+n);
-		for(p = a; port < offset+n; port++)
+		checkport(port, end);
+		for(p = a; port < end; port++)
 			*p++ = inb(port);
 		return n;
 
@@ -376,9 +378,8 @@
 	case Qiow:
 		if(n & 1)
 			error(Ebadarg);
-		checkport(offset, offset+n);
-		sp = a;
-		for(port = offset; port < offset+n; port += 2)
+		checkport(port, end);
+		for(sp = a; port < end; port += 2)
 			*sp++ = ins(port);
 		return n;
 
@@ -385,9 +386,8 @@
 	case Qiol:
 		if(n & 3)
 			error(Ebadarg);
-		checkport(offset, offset+n);
-		lp = a;
-		for(port = offset; port < offset+n; port += 4)
+		checkport(port, end);
+		for(lp = a; port < end; port += 4)
 			*lp++ = inl(port);
 		return n;
 
@@ -394,8 +394,8 @@
 	case Qmsr:
 		if(n & 7)
 			error(Ebadarg);
-		vp = a;
-		for(port = offset; port < offset+n; port += 8)
+		end = port+(n/8);
+		for(vp = a; port < end; port++)
 			if(rdmsr(port, vp++) < 0)
 				error(Ebadarg);
 		return n;
@@ -404,7 +404,8 @@
 		lock(&iomap);
 		i = 0;
 		for(m = iomap.m; m != nil; m = m->next){
-			i = snprint(buf, sizeof(buf), "%8lux %8lux %-12.12s\n", m->start, m->end-1, m->tag);
+			i = snprint(buf, sizeof(buf), "%8lux %8lux %-12.12s\n",
+				m->start, m->end-1, m->tag);
 			offset -= i;
 			if(offset < 0)
 				break;
@@ -429,18 +430,19 @@
 static long
 archwrite(Chan *c, void *a, long n, vlong offset)
 {
+	uint port, end;
 	char *p;
-	int port;
 	ushort *sp;
 	ulong *lp;
 	vlong *vp;
 	Rdwrfn *fn;
 
+	port = offset;
+	end = port+n;
 	switch((ulong)c->qid.path){
 	case Qiob:
-		p = a;
-		checkport(offset, offset+n);
-		for(port = offset; port < offset+n; port++)
+		checkport(port, end);
+		for(p = a; port < end; port++)
 			outb(port, *p++);
 		return n;
 
@@ -447,9 +449,8 @@
 	case Qiow:
 		if(n & 1)
 			error(Ebadarg);
-		checkport(offset, offset+n);
-		sp = a;
-		for(port = offset; port < offset+n; port += 2)
+		checkport(port, end);
+		for(sp = a; port < end; port += 2)
 			outs(port, *sp++);
 		return n;
 
@@ -456,9 +457,8 @@
 	case Qiol:
 		if(n & 3)
 			error(Ebadarg);
-		checkport(offset, offset+n);
-		lp = a;
-		for(port = offset; port < offset+n; port += 4)
+		checkport(port, end);
+		for(lp = a; port < end; port += 4)
 			outl(port, *lp++);
 		return n;
 
@@ -465,8 +465,8 @@
 	case Qmsr:
 		if(n & 7)
 			error(Ebadarg);
-		vp = a;
-		for(port = offset; port < offset+n; port += 8)
+		end = port+(n/8);
+		for(vp = a; port < end; port++)
 			if(wrmsr(port, *vp++) < 0)
 				error(Ebadarg);
 		return n;
-- 
⑨