Wasmtime GitHub notifications bot (Apr 16 2026 at 01:10): Wasmtime GitHub notifications bot (Apr 16 2026 at 01:10):alexcrichton requested cfallin for a review on PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 01:10):alexcrichton requested wasmtime-core-reviewers for a review on PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 01:10):alexcrichton opened PR #13118 from alexcrichton:remove-pointer-authentication to bytecodealliance:main:
This commit removes the pointer authentication instructions from our fiber implementation. There's more rationale in #12778 for this but the basic problems are:
- Android uses the "A" key to sign return addresses, but the "A" key differs between threads. This causes resuming fibers across threads to crash.
- Rust does not provide the ability to know when pointer authentication is enabled, nor does it have a way of enabling pointer authentication for generated code on stable.
- We can't currently find reference documentation for which key should be used ABI-wise for each target, nor why the Android "A" key is changing across threads in the same process.
Overall it seems like we're a bit too far out on a limb trying to enable this. In the future if all Rust code, except this inline assembly, uses pointer authentication we'll be in a good spot to reevaluate this perhaps. Until that day though it seems premature to enable this.
Closes #12778
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Wasmtime GitHub notifications bot (Apr 16 2026 at 01:21):cfallin submitted PR review:
:+1:
Wasmtime GitHub notifications bot (Apr 16 2026 at 01:21):cfallin has enabled auto merge for PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 02:42):cfallin added PR #13118 Remove pointer authentication from fibers to the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 04:10):github-merge-queue[bot] removed PR #13118 Remove pointer authentication from fibers from the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 14:28):alexcrichton updated PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 14:28):alexcrichton has enabled auto merge for PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 15:59):alexcrichton added PR #13118 Remove pointer authentication from fibers to the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 16:17):alexcrichton removed PR #13118 Remove pointer authentication from fibers from the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 19:59):alexcrichton updated PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 20:24):alexcrichton updated PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 20:24):alexcrichton has enabled auto merge for PR #13118.
Wasmtime GitHub notifications bot (Apr 16 2026 at 21:08):alexcrichton added PR #13118 Remove pointer authentication from fibers to the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 21:32):github-merge-queue[bot] removed PR #13118 Remove pointer authentication from fibers from the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 21:38):alexcrichton added PR #13118 Remove pointer authentication from fibers to the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 22:03):alexcrichton removed PR #13118 Remove pointer authentication from fibers from the merge queue.
Wasmtime GitHub notifications bot (Apr 16 2026 at 22:03):alexcrichton merged PR #13118.
Last updated: May 03 2026 at 22:13 UTC