Stream: git-wasmtime

Topic: wasmtime / PR #2676 Fix preservation of the sigaltstack o...


view this post on Zulip Wasmtime GitHub notifications bot (Feb 22 2021 at 22:03):

alexcrichton opened PR #2676 from macos-sigaltstack to main:

This commit fixes an issue discovered in the wasmtime-go bindings when
the Go runtime was crashing on macOS only when running wasm code that
trapped. It turns out that our switch to siglongjmp from longjmp
actually broke macOS! This breakage happens because all subsequent
signals after the first signal are all delivered on the main stack, not
the sigaltstack, even if the sigaltstack is configured. This causes the
Go runtime to crash since it expects to run on the sigaltstack.

The fix in this commit is to actually return from the signal handler to
trigger the kernel's updating of the sigaltstack no longer being in use.
Before we return, however, we configure the register context to return
to to call some custom code which immediately does the unwind we would
otherwise have done. This works around the issue on macOS hopefully
without adding too many portability problems. Ideally this will all go
away as well with #2632 as well.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 23 2021 at 01:05):

alexcrichton updated PR #2676 from macos-sigaltstack to main.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 23 2021 at 18:21):

peterhuene submitted PR Review.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 23 2021 at 18:42):

alexcrichton merged PR #2676.


Last updated: Oct 23 2024 at 20:03 UTC