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[runtime] Reset clobbered argument in DefineClass

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The caller of DefineClass may not expect its arguments to be mutated, so
add an arguments mutation scope which resets the argument clobbered by
DefineClass.

Bug: chromium:1268738
Change-Id: I03e9cd82535ca1f83353012a92e80f822566e64e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3283077
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77921}
This commit is contained in:
Leszek Swirski 2021-11-16 13:01:16 +01:00 committed by V8 LUCI CQ
parent 3eae9d57ef
commit 9b5f398554
2 changed files with 21 additions and 5 deletions
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19
src/execution/arguments.h
View File

@ -33,6 +33,21 @@ namespace internal {
template <ArgumentsType arguments_type>
class Arguments {
public:
// Scope to temporarily change the value of an argument.
class ChangeValueScope {
public:
ChangeValueScope(Arguments* args, int index, Object value)
: location_(args->address_of_arg_at(index)) {
old_value_ = *location_;
*location_ = value.ptr();
}
~ChangeValueScope() { *location_ = old_value_; }
private:
Address* location_;
Address old_value_;
};
Arguments(int length, Address* arguments)
: length_(length), arguments_(arguments) {
DCHECK_GE(length_, 0);
@ -51,10 +66,6 @@ class Arguments {
inline double number_at(int index) const;
inline void set_at(int index, Object value) {
*address_of_arg_at(index) = value.ptr();
}
inline FullObjectSlot slot_at(int index) const {
return FullObjectSlot(address_of_arg_at(index));
}

7
src/runtime/runtime-classes.cc
View File

@ -629,7 +629,12 @@ MaybeHandle<Object> DefineClass(Isolate* isolate,
Handle<JSObject> prototype = CreateClassPrototype(isolate);
DCHECK_EQ(*constructor, args[ClassBoilerplate::kConstructorArgumentIndex]);
args.set_at(ClassBoilerplate::kPrototypeArgumentIndex, *prototype);
// Temporarily change ClassBoilerplate::kPrototypeArgumentIndex for the
// subsequent calls, but use a scope to make sure to change it back before
// returning, to not corrupt the caller's argument frame (in particular, for
// the interpreter, to not clobber the register frame).
RuntimeArguments::ChangeValueScope set_prototype_value_scope(
&args, ClassBoilerplate::kPrototypeArgumentIndex, *prototype);
if (!InitClassConstructor(isolate, class_boilerplate, constructor_parent,
constructor, args) ||