shithub: riscv

Download patch

ref: 97a2e35a0c4a408285f2e94667f6ae069bb462e8
parent: a3d8481bb628ce254b43198f78a9f14617fa5bf9
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;