c-api: Fix alignment of wasmtime_val_*
#8363
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Subscribe to Label Actioncc @peterhuene
This issue or pull request has been labeled: "wasmtime:c-api"
Thus the following users have been cc'd because of the following labels:
To subscribe or unsubscribe from this label, edit the |
fitzgen
approved these changes
Apr 14, 2024
This commit fixes an issue where `wasmtime_val_raw_t` had an incorrect alignment. In Rust `ValRaw` contains a `u128` which has an alignment of 16 but in C the representation had a smaller alignment meaning that the alignment of the two structures was different. This was seen to cause alignment faults when structure were passed from C++ to Rust, for example. This commit changes the Rust representation of `ValRaw`'s `v128` field to do the same as C which is to use `[u8; 16]`. This avoids the need to raise the alignment in C which appears to be nontrivial. Cranelift is appropriately adjusted to understand that loads/stores from `ValRaw` are no longer aligned. Technically this only applies to the `v128` field but it's not too bad to apply it to the other fields as well.
alexcrichton
force-pushed
the
fix-val-alignment-in-c-api
branch
from
e0af353 to
42a3586
Compare
|
I ended up going the reverse direction here instead, lowering the alignment in Rust instead of raising the alignment in the C API. I don't know how to portably raise the alignment in C so I'd rather tweak the Rust side of things. |
github-merge-queue
bot
removed this pull request from the merge queue due to failed status checks
alexcrichton
added a commit
to alexcrichton/wasmtime
that referenced
this pull request
Apr 15, 2024
* c-api: Fix alignment of `wasmtime_val_*` This commit fixes an issue where `wasmtime_val_raw_t` had an incorrect alignment. In Rust `ValRaw` contains a `u128` which has an alignment of 16 but in C the representation had a smaller alignment meaning that the alignment of the two structures was different. This was seen to cause alignment faults when structure were passed from C++ to Rust, for example. This commit changes the Rust representation of `ValRaw`'s `v128` field to do the same as C which is to use `[u8; 16]`. This avoids the need to raise the alignment in C which appears to be nontrivial. Cranelift is appropriately adjusted to understand that loads/stores from `ValRaw` are no longer aligned. Technically this only applies to the `v128` field but it's not too bad to apply it to the other fields as well. * Try alternate syntax for alignof
fitzgen
added a commit
that referenced
this pull request
Apr 15, 2024
* c-api: Better differentiate between `wasm.h` and `wasmtime.h` APIs (#8344) This renames some types and adds some type aliases to help us better distinguish between `wasm.h` APIs and `wasmtime.h` APIs, primarily for `Store`-related types. In general, `WasmFoo` is related to `wasm.h` and `WasmtimeFoo` is related to `wasmtime.h`. * `StoreRef` -> `WasmStoreRef` * Introduce the `WasmStore[Data]` and `WasmStoreContext[Mut]` aliases * `StoreData` -> `WasmtimeStoreData` * `CStoreContext[Mut]` -> `WasmtimeStoreContext[Mut]` * Introduce the `Wasmtime{Store,Caller}` aliases * `wasmtime-c-api`: Improve non-support of GC references in `wasm.h` APIs (#8345) * c-api: Better differentiate between `wasm.h` and `wasmtime.h` APIs This renames some types and adds some type aliases to help us better distinguish between `wasm.h` APIs and `wasmtime.h` APIs, primarily for `Store`-related types. In general, `WasmFoo` is related to `wasm.h` and `WasmtimeFoo` is related to `wasmtime.h`. * `StoreRef` -> `WasmStoreRef` * Introduce the `WasmStore[Data]` and `WasmStoreContext[Mut]` aliases * `StoreData` -> `WasmtimeStoreData` * `CStoreContext[Mut]` -> `WasmtimeStoreContext[Mut]` * Introduce the `Wasmtime{Store,Caller}` aliases * c-api: Improve non-support of GC references in `wasm.h` APIs A couple small tweaks: error message improvements, exhaustive matching, etc... * Fix running wasi-common tests on CI (#8353) * Fix running wasi-common tests on CI Turns out we haven't been running wasi-common tests for some time in CI and they've started failing. Force enable the test at all times and then fix the test failures. The test failures here were introduced in #8277 and weren't caught due to the test not running and the fix was to relax the implementation of `fd_pread` to avoid taking multiple mutable borrows. * Fix CI * Update release notes for 20.0.0 (#8358) A busy release! * Enable the gc feature by default in the c-api (#8356) Match the Wasmtime crate in this respect * wasmtime-c-api: Add support for GC references in `wasmtime.h` APIs (#8346) Restores support for `externref` in `wasmtime_val_t`, methods for manipulating them and getting their wrapped host data, and examples/tests for these things. Additionally adds support for `anyref` in `wasmtime_val_t`, clone/delete methods similar to those for `externref`, and a few `i31ref`-specific methods. Also adds C and Rust example / test for working with `anyref`. * Fix calculation of gc refs in functions (#8355) * Fix calculation of gc refs in functions In addition to excluding i31 also exclude funcrefs. * Review comments * Remove `wasi_config_preopen_socket` from C header (#8364) This was removed in #8066 * Tidy up some headers related to shared memory (#8366) * Tidy up some headers related to shared memory * Don't declare an anonymous `struct wasmtime_sharedmemory`, instead `#include` the actual definition. * Fix an issue where a header in `sharedmemory.h` referred to a type in `extern.h` which wasn't `#include`'d. This function, `wasmtime_sharedmemory_into_extern`, additionally isn't necessary as it's no different than manually constructing it. Fix this by removing this function. * Run clang-format * c-api: Fix alignment of `wasmtime_val_*` (#8363) * c-api: Fix alignment of `wasmtime_val_*` This commit fixes an issue where `wasmtime_val_raw_t` had an incorrect alignment. In Rust `ValRaw` contains a `u128` which has an alignment of 16 but in C the representation had a smaller alignment meaning that the alignment of the two structures was different. This was seen to cause alignment faults when structure were passed from C++ to Rust, for example. This commit changes the Rust representation of `ValRaw`'s `v128` field to do the same as C which is to use `[u8; 16]`. This avoids the need to raise the alignment in C which appears to be nontrivial. Cranelift is appropriately adjusted to understand that loads/stores from `ValRaw` are no longer aligned. Technically this only applies to the `v128` field but it's not too bad to apply it to the other fields as well. * Try alternate syntax for alignof * Use `--locked` on all `cargo install` in CI, also remove non-locked example (#8369) * Use `--locked` on all `cargo install` in CI Prevents any updates to rustc or crates from accidentally causing issues by ensuring that the same set of deps is used over time. * Remove rust/WASI markdown parser example The documentation referring to this example was removed in #6994 and that forgot to remove this as well. This example is building without a lock file which is causing issues in #8368. --------- Co-authored-by: Nick Fitzgerald <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This commit fixes an issue where
wasmtime_val_raw_thad an incorrectalignment. In Rust
ValRawcontains au128which has an alignment of16 but in C the representation had a smaller alignment meaning that the
alignment of the two structures was different. This was seen to cause
alignment faults when structure were passed from C++ to Rust, for
example.
This commit changes the Rust representation of
ValRaw'sv128fieldto do the same as C which is to use
[u8; 16]. This avoids the need toraise the alignment in C which appears to be nontrivial. Cranelift is
appropriately adjusted to understand that loads/stores from
ValRawareno longer aligned. Technically this only applies to the
v128field butit's not too bad to apply it to the other fields as well.