Using fast calls for WASI causes V8 coredump

[TerrorJack]

Version

v19.7.0

Platform

Linux build01 6.0.3 #1-NixOS SMP PREEMPT_DYNAMIC Fri Oct 21 10:39:29 UTC 2022 x86_64 GNU/Linux

Subsystem

wasi

What steps will reproduce the bug?

See https://bugs.chromium.org/p/v8/issues/detail?id=13753 for the minimal repro. V8 upstream has indicated that #43697 is the culprit.

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior?

No response

What do you see instead?

See above.

Additional information

No response

[cjihrig]

cc: @devsnek

[devsnek]

It seems that calling AdjustAmountOfExternalAllocatedMemory triggers a GC :/

I am gonna kick this back to V8 lol

[bnoordhuis]

V8 says they don't consider it a bug so I guess that means node needs to defer the AdjustAmountOfExternalAllocatedMemory() call until a GC-safe point in time, i.e., until after the fast call.

Alternatively / workaround-ishly, src/node_wasi.cc could move away from NgLibMemoryManager to a memory manager that doesn't call AdjustAmountOfExternalAllocatedMemory().

I don't think that AdjustAmountOfExternalAllocatedMemory() makes sense for WASI anyway because its allocations aren't tied to JS objects so best case, it's a no-op, worst case, it makes the GC vacuum more frequently but pointlessly.