Bug 121307 – [Windows] Activate FastMalloc hardening on Windows

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[Brent Fulgham]

The hardening logic in the FastMalloc implementation works fine on Windows (with a couple of small changes to work around some Visual Studio compiler bugs).

Let's turn it on so that we can have comparable safety to our other ports!

[Radar WebKit Bug Importer]

<rdar://problem/14986554>

[Brent Fulgham]

Created attachment 211563 [details]
Patch

[Oliver Hunt]

Comment on attachment 211563 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=211563&action=review

r=me with comments

> Source/WTF/wtf/FastMalloc.cpp:110
> +#if (COMPILER(GCC) || COMPILER(MSVC)) && !PLATFORM(QT)

maybe we can just try !PLATFORM(QT) and see what happens?

> Source/WTF/wtf/FastMalloc.cpp:840
> +#if COMPILER(MSVC)
> +    void* tValNext = *(reinterpret_cast<void**>(t.value())); // FIXME: This exists to work around a MSVC bug
> +    return HardenedSLL::create(XOR_MASK_PTR_WITH_KEY(tValNext, t.value(), entropy));
> +#else
>      return HardenedSLL::create(XOR_MASK_PTR_WITH_KEY(*(reinterpret_cast<void**>(t.value())), t.value(), entropy));
> +#endif

Remove the #if MSVC and just always use that path.  It's conceivable that it's a "legitimate" piece of behaviour and it really shouldn't hurt.

[Brent Fulgham]

Committed r155717: <http://trac.webkit.org/changeset/155717>