Bug 133394 - fix arm64 css jit
Summary: fix arm64 css jit
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: CSS (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-05-29 17:10 PDT by Alex Christensen
Modified: 2014-05-29 17:26 PDT (History)
1 user (show)

See Also:

Attachments
Patch (3.46 KB, patch)
2014-05-29 17:17 PDT, Alex Christensen 		benjamin: review+
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Description Alex Christensen 2014-05-29 17:10:33 PDT 
The arm64 css jit could use a deallocated argument register to swap the argument registers in, which would generate invalid code.  To prevent this, let's use a designated temporary register for now because we have a plentiful supply of registers, then we can do better register organization later.
Comment 1 Alex Christensen 2014-05-29 17:17:14 PDT 
Created attachment 232273 [details]
Patch
Comment 2 Benjamin Poulain 2014-05-29 17:20:45 PDT 
Comment on attachment 232273 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=232273&action=review

> Source/WebCore/cssjit/SelectorCompiler.cpp:904
> +    RELEASE_ASSERT(minimumRegisterCountForAttributes <= registerCount);

Please make this an assertion instead of a release assert.
In this case, we do not risk a security problem if the assert is false. RegisterAllocator ensure we crash if we ever overallocate.
Comment 3 Alex Christensen 2014-05-29 17:26:16 PDT 
http://trac.webkit.org/changeset/169479