eliott/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird synced 2026-04-26 01:35:08 +02:00
Code Issues Packages Projects Releases Wiki Activity

LibJS: Only cache TypedArray data pointers for owned buffers

Browse Source 
WebAssembly.Memory-backed ArrayBuffers wrap external
ByteBuffer storage. When that memory grows,
ByteBuffer::try_resize() may realloc the backing storage while
old fixed-length buffer objects remain reachable from JS.

TypedArrayBase cached m_data for all fixed-length buffers, and
the asm interpreter fast path dereferenced that cached pointer
directly. For wasm memory views this could leave a stale
pointer behind across grow().

Restrict cached typed-array data pointers to fixed-length
ArrayBuffers that own stable ByteBuffer storage.
External/unowned buffers, including WebAssembly.Memory
buffers, now keep m_data == nullptr and fall back to code that
re-derives buffer().data() on each access.

Add regressions for both the original shared-memory grow case
and the second-grow stale-view case.
This commit is contained in:
Yayoi-cs
2026-04-25 02:10:20 +09:00
committed by Andreas Kling
parent 5d69c6d2b7
commit 0b9636fadf
Notes: github-actions[bot] 2026-04-25 04:12:12 +00:00 
Author: https://github.com/Yayoi-cs
Commit: https://github.com/LadybirdBrowser/ladybird/commit/0b9636fadfc
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/9086
6 changed files with 53 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
Libraries/LibWeb/WebAssembly/Memory.cpp
View File

@@ -216,8 +216,6 @@ void Memory::refresh_the_memory_buffer(JS::VM& vm, JS::Realm& realm, Wasm::Memor
if (!buffer->is_shared_array_buffer()) {
// 1. Perform ! DetachArrayBuffer(buffer, "WebAssembly.Memory").
MUST(JS::detach_array_buffer(vm, *buffer, JS::PrimitiveString::create(vm, "WebAssembly.Memory"_string)));
} else {
buffer->refresh_cached_typed_array_view_data_pointers();
}
// 2. Let newBuffer be the result of creating a fixed length memory buffer from memaddr.