gc: be pickier about slice, chan, array, and map sizes

Fixes #589.

R=ken2
CC=golang-dev
https://golang.org/cl/1032044

4 files changed, 25 insertions, 16 deletions

diff --git a/src/pkg/runtime/chan.c b/src/pkg/runtime/chan.c
index 5793159062..08cd75a6e5 100644
--- a/src/pkg/runtime/chan.c
+++ b/src/pkg/runtime/chan.c
@@ -90,11 +90,14 @@ static	uint32	fastrand2(void);
 static	void	destroychan(Hchan*);
 
 Hchan*
-makechan(Type *elem, uint32 hint)
+makechan(Type *elem, int64 hint)
 {
 	Hchan *c;
 	int32 i;
 
+	if(hint < 0 || (int32)hint != hint || hint > ((uintptr)-1) / elem->size)
+		panicstring("makechan: size out of range");
+
 	if(elem->alg >= nelem(algarray)) {
 		printf("chan(alg=%d)\n", elem->alg);
 		throw("runtime.makechan: unsupported elem type");
@@ -141,9 +144,9 @@ destroychan(Hchan *c)
 }
 
 
-// makechan(elemsize uint32, elemalg uint32, hint uint32) (hchan *chan any);
+// makechan(elem *Type, hint int64) (hchan *chan any);
 void
-·makechan(Type *elem, uint32 hint, Hchan *ret)
+·makechan(Type *elem, int64 hint, Hchan *ret)
 {
 	ret = makechan(elem, hint);
 	FLUSH(&ret);
diff --git a/src/pkg/runtime/hashmap.c b/src/pkg/runtime/hashmap.c
index f27264b682..9b039121bb 100644
--- a/src/pkg/runtime/hashmap.c
+++ b/src/pkg/runtime/hashmap.c
@@ -667,11 +667,14 @@ static	int32	debug	= 0;
 
 // makemap(key, val *Type, hint uint32) (hmap *map[any]any);
 Hmap*
-makemap(Type *key, Type *val, uint32 hint)
+makemap(Type *key, Type *val, int64 hint)
 {
 	Hmap *h;
 	int32 keyalg, valalg, keysize, valsize;
 
+	if(hint < 0 || (int32)hint != hint)
+		panicstring("makemap: size out of range");
+
 	keyalg = key->alg;
 	valalg = val->alg;
 	keysize = key->size;
@@ -731,9 +734,9 @@ makemap(Type *key, Type *val, uint32 hint)
 	return h;
 }
 
-// makemap(key, val *Type, hint uint32) (hmap *map[any]any);
+// makemap(key, val *Type, hint int64) (hmap *map[any]any);
 void
-·makemap(Type *key, Type *val, uint32 hint, Hmap *ret)
+·makemap(Type *key, Type *val, int64 hint, Hmap *ret)
 {
 	ret = makemap(key, val, hint);
 	FLUSH(&ret);
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index ff4f463b37..4c9f52e85c 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -577,9 +577,9 @@ struct hash_iter*	mapiterinit(Hmap*);
 void	mapiternext(struct hash_iter*);
 bool	mapiterkey(struct hash_iter*, void*);
 void	mapiterkeyvalue(struct hash_iter*, void*, void*);
-Hmap*	makemap(Type*, Type*, uint32);
+Hmap*	makemap(Type*, Type*, int64);
 
-Hchan*	makechan(Type*, uint32);
+Hchan*	makechan(Type*, int64);
 void	chansend(Hchan*, void*, bool*);
 void	chanrecv(Hchan*, void*, bool*);
 void	chanclose(Hchan*);
diff --git a/src/pkg/runtime/slice.c b/src/pkg/runtime/slice.c
index c3c079c670..d967b1669b 100644
--- a/src/pkg/runtime/slice.c
+++ b/src/pkg/runtime/slice.c
@@ -9,17 +9,20 @@
 static	int32	debug	= 0;
 
 // see also unsafe·NewArray
-// makeslice(typ *Type, nel int, cap int) (ary []any);
+// makeslice(typ *Type, len, cap int64) (ary []any);
 void
-·makeslice(SliceType *t, uint32 nel, uint32 cap, Slice ret)
+·makeslice(SliceType *t, int64 len, int64 cap, Slice ret)
 {
-	uint64 size;
+	uintptr size;
+
+	if(len < 0 || (int32)len != len)
+		panicstring("makeslice: len out of range");
+	if(cap < len || (int32)cap != cap || cap > ((uintptr)-1) / t->elem->size)
+		panicstring("makeslice: cap out of range");
 
-	if(cap < nel)
-		cap = nel;
 	size = cap*t->elem->size;
 
-	ret.len = nel;
+	ret.len = len;
 	ret.cap = cap;
 
 	if((t->elem->kind&KindNoPointers))
@@ -30,8 +33,8 @@ void
 	FLUSH(&ret);
 
 	if(debug) {
-		printf("makeslice(%S, %d, %d); ret=",
-			*t->string, nel, cap);
+		printf("makeslice(%S, %D, %D); ret=",
+			*t->string, len, cap);
  		·printslice(ret);
 	}
 }