654073 - Crash [@ js_GetClassPrototype] or [@ JSID_IS_VOID] or [@ js::PropertyTable::search]

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Attachment: stack

for (i = 0; i < 9; i++) {
    for (x in Math.__proto__) {}
    try {
        Math.__proto__.__proto__ = this
    } catch (e) {}
    __proto__ = null
}

crashes js opt shell on TM changeset e2843f43757e without -m nor -j at js_GetClassPrototype and crashes js debug shell at JSID_IS_VOID or js::PropertyTable::search.

autoBisect shows this is probably related to the following changeset:

The first bad revision is:
changeset:   68345:881c06ebc5ee
user:        Paul Biggar
date:        Wed Apr 27 04:13:56 2011 -0700
summary:     Bug 642772: Don't recreate a class during enumeration, if it has been deleted (r=bhackett)

Comment 1

[Jeff Walden [:Waldo]]

It's a stack overflow trying to init the Iterator class for the StopIteration object, which has JSCLASS_FREEZE_PROTO, and it looks like that [[Prototype]] is somehow the global object, which means you enumerate standard classes before freezing, which means you init the Iterator class...

Did a MarkStandardClassInitializedNoProto get omitted for the Iterator class or something?  That's the only thing that looks obviously plausible as the blame-catcher in the regressor.

Bootstrapping genericity delenda est.

Comment 2

[Paul Biggar]

Attachment: Fix

Comment 3

[Jeff Walden [:Waldo]]

Comment on attachment 529700 [details] [diff] [review]
Fix

>diff --git a/js/src/jit-test/tests/basic/bug654073.js b/js/src/jit-test/tests/basic/bug654073.js

>+this.__proto__ = null;
>+Math.__proto__.__proto__ = this;
>+for (x in Math.__proto__) {}

I think this would be a clearer equivalent that's easier to read, because it doesn't require dredging up prototype chain details from memory:

this.__proto__ = null;
Object.prototype.__proto__ = this;
for (var x in Object.prototype);

Comment 4

[Paul Biggar]

http://hg.mozilla.org/tracemonkey/rev/a15c6194d2f0

Comment 5

[Chris Leary [:cdleary] (not checking bugmail)]

cdleary-bot mozilla-central merge info:
http://hg.mozilla.org/mozilla-central/rev/a15c6194d2f0

Comment 6

[Christian Riechers]

TB9.0.1 crashed. OS is openSuSE 11.4.
Please re-open this bug.
Crash Signature: [@ js::PropertyTable::search ]
ID: 0463ff9f-d0fd-4642-bb16-50e2d2120108

Comment 7

[Christian Holler (:decoder)]

A testcase for this bug was automatically identified at js/src/jit-test/tests/basic/bug654073.js.