Handle same-compartment wrappers in TypedArray methods.

CallTypedArrayMethodIfWrapped (and the CallNonGeneric machinery throughout the
engine) unwraps the `this` argument, but the other arguments are only rewrapped
for the target compartment.

The pattern being used before this patch to get the length of a TypedArray or
possible TypedArray wrapper is:
`callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength")`
The first `O` is the `this` value and the second is an argument. If `O` is a
cross-compartment wrapper, this works fine. The first `O` is unwrapped, revealing
the actual TypedArray object; the second `O` is rewrapped for that TypedArray's
compartment, producing the same TypedArray.
However, if `O` is a same-compartment wrapper, this doesn't work. The first `O` is
unwrapped, revealing the actual TypedArray object in the same compartment;
rewrapping the other `O` does nothing to it, since it is already an object in the
target compartment. Thus TypedArrayLength receives a `this` value that's an
unwrapped TypedArray, but an argument that is still a wrapper.

The fix is to have CallTypedArrayMethodIfWrapped targets only expect `this`
to be an unwrapped TypedArray.
This commit is contained in:
wolfbeast 2018-03-17 10:47:56 +01:00 • committed by Roy Tam
commit 04caaa6539
3 changed files with 55 additions and 40 deletions

View file

@ -35,6 +35,10 @@ function IsDetachedBuffer(buffer) {
return (flags & JS_ARRAYBUFFER_DETACHED_FLAG) !== 0;
}
function TypedArrayLengthMethod() {
return TypedArrayLength(this);
}
function GetAttachedArrayBuffer(tarray) {
var buffer = ViewedArrayBufferIfReified(tarray);
if (IsDetachedBuffer(buffer))
@ -42,6 +46,10 @@ function GetAttachedArrayBuffer(tarray) {
return buffer;
}
function GetAttachedArrayBufferMethod() {
return GetAttachedArrayBuffer(this);
}
// A function which ensures that the argument is either a typed array or a
// cross-compartment wrapper for a typed array and that the typed array involved
// has an attached array buffer. If one of those conditions doesn't hold (wrong
@ -54,10 +62,7 @@ function IsTypedArrayEnsuringArrayBuffer(arg) {
return true;
}
// This is a bit hacky but gets the job done: the first `arg` is used to
// test for a wrapped typed array, the second as an argument to
// GetAttachedArrayBuffer.
callFunction(CallTypedArrayMethodIfWrapped, arg, arg, "GetAttachedArrayBuffer");
callFunction(CallTypedArrayMethodIfWrapped, arg, "GetAttachedArrayBufferMethod");
return false;
}
@ -98,8 +103,8 @@ function TypedArrayCreateWithLength(constructor, length) {
if (isTypedArray) {
len = TypedArrayLength(newTypedArray);
} else {
len = callFunction(CallTypedArrayMethodIfWrapped, newTypedArray, newTypedArray,
"TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, newTypedArray,
"TypedArrayLengthMethod");
}
if (len < length)
@ -259,15 +264,14 @@ function TypedArrayEvery(callbackfn/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -348,15 +352,14 @@ function TypedArrayFilter(callbackfn/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Step 3.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 4.
if (arguments.length === 0)
@ -410,15 +413,14 @@ function TypedArrayFind(predicate/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -452,15 +454,14 @@ function TypedArrayFindIndex(predicate/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -492,15 +493,14 @@ function TypedArrayForEach(callbackfn/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Step 3-4.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 5.
if (arguments.length === 0)
@ -686,15 +686,14 @@ function TypedArrayMap(callbackfn/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Step 3.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 4.
if (arguments.length === 0)
@ -730,15 +729,14 @@ function TypedArrayReduce(callbackfn/*, initialValue*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -776,15 +774,14 @@ function TypedArrayReduceRight(callbackfn/*, initialValue*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -1034,15 +1031,14 @@ function TypedArraySome(callbackfn/*, thisArg*/) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(O);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Steps 3-5.
var len;
if (isTypedArray)
len = TypedArrayLength(O);
else
len = callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, O, "TypedArrayLengthMethod");
// Step 6.
if (arguments.length === 0)
@ -1137,7 +1133,7 @@ function TypedArraySort(comparefn) {
if (isTypedArray) {
buffer = GetAttachedArrayBuffer(obj);
} else {
buffer = callFunction(CallTypedArrayMethodIfWrapped, obj, obj, "GetAttachedArrayBuffer");
buffer = callFunction(CallTypedArrayMethodIfWrapped, obj, "GetAttachedArrayBufferMethod");
}
// Step 3.
@ -1145,7 +1141,7 @@ function TypedArraySort(comparefn) {
if (isTypedArray) {
len = TypedArrayLength(obj);
} else {
len = callFunction(CallTypedArrayMethodIfWrapped, obj, obj, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, obj, "TypedArrayLengthMethod");
}
if (comparefn === undefined) {
@ -1181,8 +1177,8 @@ function TypedArraySort(comparefn) {
if (isTypedArray) {
buffer = GetAttachedArrayBuffer(obj);
} else {
buffer = callFunction(CallTypedArrayMethodIfWrapped, obj, obj,
"GetAttachedArrayBuffer");
buffer = callFunction(CallTypedArrayMethodIfWrapped, obj,
"GetAttachedArrayBufferMethod");
}
}
var bufferDetached;
@ -1217,15 +1213,14 @@ function TypedArrayToLocaleString(locales = undefined, options = undefined) {
// We want to make sure that we have an attached buffer, per spec prose.
var isTypedArray = IsTypedArrayEnsuringArrayBuffer(array);
// If we got here, `this` is either a typed array or a cross-compartment
// wrapper for one.
// If we got here, `this` is either a typed array or a wrapper for one.
// Step 2.
var len;
if (isTypedArray)
len = TypedArrayLength(array);
else
len = callFunction(CallTypedArrayMethodIfWrapped, array, array, "TypedArrayLength");
len = callFunction(CallTypedArrayMethodIfWrapped, array, "TypedArrayLengthMethod");
// Step 4.
if (len === 0)

View file

@ -0,0 +1 @@
[...wrapWithProto(new Int8Array(), new Int8Array())]

View file

@ -0,0 +1,19 @@
let a = wrapWithProto(new Int8Array([1, 3, 5, 6, 9]), new Int8Array());
assertEq([...a].toString(), "1,3,5,6,9");
assertEq(a.every(e => e < 100), true);
assertEq(a.filter(e => e % 2 == 1).toString(), "1,3,5,9");
assertEq(a.find(e => e > 3), 5);
assertEq(a.findIndex(e => e % 2 == 0), 3);
assertEq(a.map(e => e * 10).toString(), "10,30,50,60,90");
assertEq(a.reduce((a, b) => a + b, ""), "13569");
assertEq(a.reduceRight((acc, e) => "(" + e + acc + ")", ""), "(1(3(5(6(9)))))");
assertEq(a.some(e => e % 2 == 0), true);
let s = "";
assertEq(a.forEach(e => s += e), undefined);
assertEq(s, "13569");
a.sort((a, b) => b - a);
assertEq(a.toString(), "9,6,5,3,1");