Bug 169882

Summary: WebAssembly: allocate no more than 4GiB for Signaling memory
Product: WebKit Reporter: JF Bastien <jfbastien>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: fpizlo, jfbastien, keith_miller, mark.lam, msaboff, sbarati
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=170628
Bug Depends on:    
Bug Blocks: 159775    

Description JF Bastien 2017-03-20 11:19:33 PDT
We currently virtually allocate 8GiB because odd corner cases potentially allow accesses to go above 4GiB. Those would always trap, so we need the memory to be mapped. This lowers the number of "fast" signaling memory we can allocate, it would be better to figure out which accesses could go above 4GiB, bounds check those, and all the other ones can stay entirely unchecked.

Note: maybe we want 4GiB + some small redzone for small offsets.
Comment 1 JF Bastien 2017-04-07 17:13:38 PDT

*** This bug has been marked as a duplicate of bug 170628 ***