Wasmtime GitHub notifications bot (Mar 06 2025 at 19:54): Wasmtime GitHub notifications bot (Mar 06 2025 at 19:54):fitzgen opened PR #10349 from fitzgen:free-list-and-v128 to bytecodealliance:main:
Additionally, support alignment 16 for
v128s inside GC objects.We previously allowed the alignment and minimum block size to be different values, and did not round allocation sizes up to the minimum block size. This could lead to bugs like the following sequence of events:
- free list initially has a block 0x10..MAX
- alloc(size=16) -> 0x10
- free list now has one block: 0x20..MAX
- alloc(size=16) -> 0x20
- free list now has one block: 0x30..MAX
- dealloc(0x10, size=16)
- this merges 0x10..0x20 into 0x30..MAX because the gap between 0x20 and 0x30 is smaller than the minimum block size
- dealloc(0x20, size=16)
- triggers overlapping blocks assertion failure!
If we ensure that the minimum allocation size is a multiple of our supported alignment and we clamp requested allocations' sizes to at least the minimum block size, then we could avoid this.
It is simpler, however, to unify our supported alignment and our minimum block size into the same value. This PR does that. No more need for multiple concepts which interact in subtle ways.
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Wasmtime GitHub notifications bot (Mar 06 2025 at 19:54):fitzgen requested wasmtime-core-reviewers for a review on PR #10349.
Wasmtime GitHub notifications bot (Mar 06 2025 at 19:54):fitzgen requested dicej for a review on PR #10349.
Wasmtime GitHub notifications bot (Mar 06 2025 at 21:44):github-actions[bot] commented on PR #10349:
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Wasmtime GitHub notifications bot (Mar 06 2025 at 21:46):alexcrichton submitted PR review.
Wasmtime GitHub notifications bot (Mar 06 2025 at 22:07):alexcrichton merged PR #10349.
Last updated: Apr 17 2025 at 20:03 UTC