[webkit-reviews] review denied: [Bug 16026] GC: Using != when comparing pointers when marking stack objects can cause segfaults : [Attachment 17328] Use < not != in markStackObjectsConservatively

[bugzilla-daemon at webkit.org]

Darin Adler <darin at apple.com> has denied Ryan Leavengood
<leavengood at gmail.com>'s request for review:
Bug 16026: GC: Using != when comparing pointers when marking stack objects can
cause segfaults
http://bugs.webkit.org/show_bug.cgi?id=16026

Attachment 17328: Use < not != in markStackObjectsConservatively
http://bugs.webkit.org/attachment.cgi?id=17328&action=edit

------- Additional Comments from Darin Adler <darin at apple.com>
If memory is not aligned correctly, there are other problems besides the loop
termination condition. For example, the garbage collector will miss pointers on
the stack and collect objects that are actually in use.

So while this patch is harmless for platforms where things are already correct,
it's not actually sufficient to fix your port.

I suggest further investigation of why you don't have alignment. A larger
change may be necessary if the storage on the stack is not guaranteed to be
aligned -- you may need to walk the stack 2 bytes at a time or even 1 byte at a
time, in which case you'll need to change more than just this loop termination
condition.