Bug 171707 – CallLinkInfos belonging to Wasm->JS stubs need to be informed when we clearCode() from all Executables

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Saam Barati]

Otherwise, we end up with a situation like this:
1. We generate our IC which has a branch on a callee check. If the branch succeeds, we will call code for a particular CodeBlock.
2. Heap::deleteAllCodeBlocks is called. This leads the Executable to clear its various codeBlock references.
3. Wasm has no idea this happened, so now it has stale ICs that point into code from a CodeBlock no longer belonging to an Executable.

[Saam Barati]

<rdar://problem/31891649>

[Saam Barati]

Created attachment 309130 [details]
patch

[Build Bot]

Attachment 309130 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/wasm/js/JSWebAssemblyCodeBlockSubspace.cpp:31:  Alphabetical sorting problem.  [build/include_order] [4]
ERROR: Source/JavaScriptCore/wasm/js/JSWebAssemblyCodeBlockSubspace.cpp:32:  Alphabetical sorting problem.  [build/include_order] [4]
ERROR: Source/JavaScriptCore/heap/Heap.cpp:51:  Alphabetical sorting problem.  [build/include_order] [4]
Total errors found: 3 in 11 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Created attachment 309189 [details]
patch

[Build Bot]

Attachment 309189 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/wasm/js/JSWebAssemblyCodeBlockSubspace.cpp:31:  Alphabetical sorting problem.  [build/include_order] [4]
ERROR: Source/JavaScriptCore/wasm/js/JSWebAssemblyCodeBlockSubspace.cpp:32:  Alphabetical sorting problem.  [build/include_order] [4]
ERROR: Source/JavaScriptCore/heap/Heap.cpp:51:  Alphabetical sorting problem.  [build/include_order] [4]
Total errors found: 3 in 12 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Saam Barati]

Created attachment 309190 [details]
patch

fix include ordering

[Filip Pizlo]

Comment on attachment 309190 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=309190&action=review

Looks good!

> Source/JavaScriptCore/runtime/VM.cpp:176
> +    , webAssemblyCodeBlockSubspace("JSWebAssemblyCodeBlockSubspace", heap)

I've been calling these "Spaces" and not "Subspaces".  It's a subspace of the heap but it's the space of web assembly code blocks.  But, I don't feel very strongly about this.  For example, I would be in favor of renaming all of them to have the "Subspace" suffix (including the two in WebCore).  I'm a bit less sure about having the naming be inconsistent.

[Saam Barati]

Created attachment 309465 [details]
patch for landing

I made Fil's naming suggestion.

[WebKit Commit Bot]

Comment on attachment 309465 [details]
patch for landing

Clearing flags on attachment: 309465

Committed r216481: <http://trac.webkit.org/changeset/216481>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Keith Miller]

*** Bug 165639 has been marked as a duplicate of this bug. ***