* Use rsix to make system calls in Wasmtime.
`rsix` is a system call wrapper crate that we use in `wasi-common`,
which can provide the following advantages in the rest of Wasmtime:
- It eliminates some `unsafe` blocks in Wasmtime's code. There's
still an `unsafe` block in the library, but this way, the `unsafe`
is factored out and clearly scoped.
- And, it makes error handling more consistent, factoring out code for
checking return values and `io::Error::last_os_error()`, and code that
does `errno::set_errno(0)`.
This doesn't cover *all* system calls; `rsix` doesn't implement
signal-handling APIs, and this doesn't cover calls made through `std` or
crates like `userfaultfd`, `rand`, and `region`.
This commit improves the runtime support for wasm-to-host invocations
for functions created with `Func::new` or `wasmtime_func_new` in the C
API. Previously a `Vec` (sometimes a `SmallVec`) would be dynamically
allocated on each host call to store the arguments that are coming from
wasm and going to the host. In the case of the `wasmtime` crate we need
to decode the `u128`-stored values, and in the case of the C API we need
to decode the `Val` into the C API's `wasmtime_val_t`.
The technique used in this commit is to store a singular `Vec<T>` inside
the "store", be it the literal `Store<T>` or within the `T` in the case
of the C API, which can be reused across wasm->host calls. This means
that we're unlikely to actually perform dynamic memory allocation and
instead we should hit a faster path where the `Vec` always has enough
capacity.
Note that this is just a mild improvement for `Func::new`-based
functions. It's still the case that `Func::wrap` is much faster, but
unfortunately the C API doesn't have access to `Func::wrap`, so the main
motivation here is accelerating the C API.
- Fixes for compiling on OpenBSD
- io-lifetimes 0.3.0 has an option (io_lifetimes_use_std, which is off
by default) for testing the `io_safety` feature in Rust nightly.
* Add differential fuzzing against V8
This commit adds a differential fuzzing target to Wasmtime along the
lines of the wasmi and spec interpreters we already have, but with V8
instead. The intention here is that wasmi is unlikely to receive updates
over time (e.g. for SIMD), and the spec interpreter is not suitable for
fuzzing against in general due to its performance characteristics. The
hope is that V8 is indeed appropriate to fuzz against because it's
naturally receiving updates and it also is expected to have good
performance.
Here the `rusty_v8` crate is used which provides bindings to V8 as well
as precompiled binaries by default. This matches exactly the use case we
need and at least for now I think the `rusty_v8` crate will be
maintained by the Deno folks as they continue to develop it. If it
becomes an issue though maintaining we can evaluate other options to
have differential fuzzing against.
For now this commit enables the SIMD and bulk-memory feature of
fuzz-target-generation which should enable them to get
differentially-fuzzed with V8 in addition to the compilation fuzzing
we're already getting.
* Use weak linkage for GDB jit helpers
This should help us deduplicate our symbol with other JIT runtimes, if
any. For now this leans on some C helpers to define the weak linkage
since Rust doesn't support that on stable yet.
* Don't use rusty_v8 on MinGW
They don't have precompiled libraries there.
* Fix msvc build
* Comment about execution
Similar functionality to `scroll` is provided with the `object` crate
and doesn't have a `*_derive` crate to go with it. This commit updates
the jitdump linux support to use `object` instead of `scroll` to achieve
the needs of writing structs-as-bytes onto disk.
* Use an mmap-friendly serialization format
This commit reimplements the main serialization format for Wasmtime's
precompiled artifacts. Previously they were generally a binary blob of
`bincode`-encoded metadata prefixed with some versioning information.
The downside of this format, though, is that loading a precompiled
artifact required pushing all information through `bincode`. This is
inefficient when some data, such as trap/address tables, are rarely
accessed.
The new format added in this commit is one which is designed to be
`mmap`-friendly. This means that the relevant parts of the precompiled
artifact are already page-aligned for updating permissions of pieces
here and there. Additionally the artifact is optimized so that if data
is rarely read then we can delay reading it until necessary.
The new artifact format for serialized modules is an ELF file. This is
not a public API guarantee, so it cannot be relied upon. In the meantime
though this is quite useful for exploring precompiled modules with
standard tooling like `objdump`. The ELF file is already constructed as
part of module compilation, and this is the main contents of the
serialized artifact.
THere is some extra information, though, not encoded in each module's
individual ELF file such as type information. This information continues
to be `bincode`-encoded, but it's intended to be much smaller and much
faster to deserialize. This extra information is appended to the end of
the ELF file. This means that the original ELF file is still a valid ELF
file, we just get to have extra bits at the end. More information on the
new format can be found in the module docs of the serialization module
of Wasmtime.
Another refatoring implemented as part of this commit is to deserialize
and store object files directly in `mmap`-backed storage. This avoids
the need to copy bytes after the artifact is loaded into memory for each
compiled module, and in a future commit it opens up the door to avoiding
copying the text section into a `CodeMemory`. For now, though, the main
change is that copies are not necessary when loading from a precompiled
compilation artifact once the artifact is itself in mmap-based memory.
To assist with managing `mmap`-based memory a new `MmapVec` type was
added to `wasmtime_jit` which acts as a form of `Vec<T>` backed by a
`wasmtime_runtime::Mmap`. This type notably supports `drain(..N)` to
slice the buffer into disjoint regions that are all separately owned,
such as having a separately owned window into one artifact for all
object files contained within.
Finally this commit implements a small refactoring in `wasmtime-cache`
to use the standard artifact format for cache entries rather than a
bincode-encoded version. This required some more hooks for
serializing/deserializing but otherwise the crate still performs as
before.
* Review comments
* Convert compilation artifacts to just bytes
This commit strips the `CompilationArtifacts` type down to simply a list
of bytes. This moves all extra metadata elsewhere to live within the
list of bytes itself as `bincode`-encoded information.
Small affordance is made to avoid an in-process
serialize-then-deserialize round-trip for use cases like `Module::new`,
but otherwise this is mostly just moving some data around.
* Rename data section to `.rodata.wasm`
* Merge `wasmtime-jit` and `wasmtime-profiling`
This commit merges the `wasmtime-profiling` crate into the
`wasmtime-jit` crate. It wasn't really buying a ton being a separate
crate and an upcoming refactoring I'd like to do is to remove the
`FinishedFunctions` structure. To enable the profilers to work as they
used to this commit changes them to pass `CompiledModule` as the
argument, but this only works if the profiling trait can see the
`CompiledModule` type.
* Fix a length calculation
* Move wasm data/debuginfo into the ELF compilation image
This commit moves existing allocations of `Box<[u8]>` stored separately
from compilation's final ELF image into the ELF image itself. The goal
of this commit is to reduce the amount of data which `bincode` will need
to process in the future. DWARF debugging information and wasm data
segments can be quite large, and they're relatively rarely read, so
there's typically no need to copy them around. Instead by moving them
into the ELF image this opens up the opportunity in the future to
eliminate copies and use data directly as-found in the image itself.
For information accessed possibly-multiple times, such as the wasm data
ranges, the indexes of the data within the ELF image are computed when
a `CompiledModule` is created. These indexes are then used to directly
index into the image without having to root around in the ELF file each
time they're accessed.
One other change located here is that the symbolication context
previously cloned the debug information into it to adhere to the
`'static` lifetime safely, but this isn't actually ever used in
`wasmtime` right now so the unsafety around this has been removed and
instead borrowed data is returned (no more clones, yay!).
* Fix lightbeam
* Remove unnecessary into_iter/map
Forgotten from a previous refactoring, this variable was already of the
right type!
* Move `wasmtime_jit::Compiler` into `wasmtime`
This `Compiler` struct is mostly a historical artifact at this point and
wasn't necessarily pulling much weight any more. This organization also
doesn't lend itself super well to compiling out `cranelift` when the
`Compiler` here is used for both parallel iteration configuration
settings as well as compilation.
The movement into `wasmtime` is relatively small, with
`Module::build_artifacts` being the main function added here which is a
merging of the previous functions removed from the `wasmtime-jit` crate.
* Add a `cranelift` compile-time feature to `wasmtime`
This commit concludes the saga of refactoring Wasmtime and making
Cranelift an optional dependency by adding a new Cargo feature to the
`wasmtime` crate called `cranelift`, which is enabled by default.
This feature is implemented by having a new cfg for `wasmtime` itself,
`cfg(compiler)`, which is used wherever compilation is necessary. This
bubbles up to disable APIs such as `Module::new`, `Func::new`,
`Engine::precompile_module`, and a number of `Config` methods affecting
compiler configuration. Checks are added to CI that when built in this
mode Wasmtime continues to successfully build. It's hoped that although
this is effectively "sprinkle `#[cfg]` until things compile" this won't
be too too bad to maintain over time since it's also an use case we're
interested in supporting.
With `cranelift` disabled the only way to create a `Module` is with the
`Module::deserialize` method, which requires some form of precompiled
artifact.
Two consequences of this change are:
* `Module::serialize` is also disabled in this mode. The reason for this
is that serialized modules contain ISA/shared flags encoded in them
which were used to produce the compiled code. There's no storage for
this if compilation is disabled. This could probably be re-enabled in
the future if necessary, but it may not end up being all that necessary.
* Deserialized modules are not checked to ensure that their ISA/shared
flags are compatible with the host CPU. This is actually already the
case, though, with normal modules. We'll likely want to fix this in
the future using a shared implementation for both these locations.
Documentation should be updated to indicate that `cranelift` can be
disabled, although it's not really the most prominent documentation
because this is expected to be a somewhat niche use case (albeit
important, just not too common).
* Always enable cranelift for the C API
* Fix doc example builds
* Fix check tests on GitHub Actions
* Move `CompiledFunction` into wasmtime-cranelift
This commit moves the `wasmtime_environ::CompiledFunction` type into the
`wasmtime-cranelift` crate. This type has lots of Cranelift-specific
pieces of compilation and doesn't need to be generated by all Wasmtime
compilers. This replaces the usage in the `Compiler` trait with a
`Box<Any>` type that each compiler can select. Each compiler must still
produce a `FunctionInfo`, however, which is shared information we'll
deserialize for each module.
The `wasmtime-debug` crate is also folded into the `wasmtime-cranelift`
crate as a result of this commit. One possibility was to move the
`CompiledFunction` commit into its own crate and have `wasmtime-debug`
depend on that, but since `wasmtime-debug` is Cranelift-specific at this
time it didn't seem like it was too too necessary to keep it separate.
If `wasmtime-debug` supports other backends in the future we can
recreate a new crate, perhaps with it refactored to not depend on
Cranelift.
* Move wasmtime_environ::reference_type
This now belongs in wasmtime-cranelift and nowhere else
* Remove `Type` reexport in wasmtime-environ
One less dependency on `cranelift-codegen`!
* Remove `types` reexport from `wasmtime-environ`
Less cranelift!
* Remove `SourceLoc` from wasmtime-environ
Change the `srcloc`, `start_srcloc`, and `end_srcloc` fields to a custom
`FilePos` type instead of `ir::SourceLoc`. These are only used in a few
places so there's not much to lose from an extra abstraction for these
leaf use cases outside of cranelift.
* Remove wasmtime-environ's dep on cranelift's `StackMap`
This commit "clones" the `StackMap` data structure in to
`wasmtime-environ` to have an independent representation that that
chosen by Cranelift. This allows Wasmtime to decouple this runtime
dependency of stack map information and let the two evolve
independently, if necessary.
An alternative would be to refactor cranelift's implementation into a
separate crate and have wasmtime depend on that but it seemed a bit like
overkill to do so and easier to clone just a few lines for this.
* Define code offsets in wasmtime-environ with `u32`
Don't use Cranelift's `binemit::CodeOffset` alias to define this field
type since the `wasmtime-environ` crate will be losing the
`cranelift-codegen` dependency soon.
* Commit to using `cranelift-entity` in Wasmtime
This commit removes the reexport of `cranelift-entity` from the
`wasmtime-environ` crate and instead directly depends on the
`cranelift-entity` crate in all referencing crates. The original reason
for the reexport was to make cranelift version bumps easier since it's
less versions to change, but nowadays we have a script to do that.
Otherwise this encourages crates to use whatever they want from
`cranelift-entity` since we'll always depend on the whole crate.
It's expected that the `cranelift-entity` crate will continue to be a
lean crate in dependencies and suitable for use at both runtime and
compile time. Consequently there's no need to avoid its usage in
Wasmtime at runtime, since "remove Cranelift at compile time" is
primarily about the `cranelift-codegen` crate.
* Remove most uses of `cranelift-codegen` in `wasmtime-environ`
There's only one final use remaining, which is the reexport of
`TrapCode`, which will get handled later.
* Limit the glob-reexport of `cranelift_wasm`
This commit removes the glob reexport of `cranelift-wasm` from the
`wasmtime-environ` crate. This is intended to explicitly define what
we're reexporting and is a transitionary step to curtail the amount of
dependencies taken on `cranelift-wasm` throughout the codebase. For
example some functions used by debuginfo mapping are better imported
directly from the crate since they're Cranelift-specific. Note that
this is intended to be a temporary state affairs, soon this reexport
will be gone entirely.
Additionally this commit reduces imports from `cranelift_wasm` and also
primarily imports from `crate::wasm` within `wasmtime-environ` to get a
better sense of what's imported from where and what will need to be
shared.
* Extract types from cranelift-wasm to cranelift-wasm-types
This commit creates a new crate called `cranelift-wasm-types` and
extracts type definitions from the `cranelift-wasm` crate into this new
crate. The purpose of this crate is to be a shared definition of wasm
types that can be shared both by compilers (like Cranelift) as well as
wasm runtimes (e.g. Wasmtime). This new `cranelift-wasm-types` crate
doesn't depend on `cranelift-codegen` and is the final step in severing
the unconditional dependency from Wasmtime to `cranelift-codegen`.
The final refactoring in this commit is to then reexport this crate from
`wasmtime-environ`, delete the `cranelift-codegen` dependency, and then
update all `use` paths to point to these new types.
The main change of substance here is that the `TrapCode` enum is
mirrored from Cranelift into this `cranelift-wasm-types` crate. While
this unfortunately results in three definitions (one more which is
non-exhaustive in Wasmtime itself) it's hopefully not too onerous and
ideally something we can patch up in the future.
* Get lightbeam compiling
* Remove unnecessary dependency
* Fix compile with uffd
* Update publish script
* Fix more uffd tests
* Rename cranelift-wasm-types to wasmtime-types
This reflects the purpose a bit more where it's types specifically
intended for Wasmtime and its support.
* Fix publish script
* Reimplement how unwind information is stored
This commit is a major refactoring of how unwind information is stored
after compilation of a function has finished. Previously we would store
the raw `UnwindInfo` as a result of compilation and this would get
serialized/deserialized alongside the rest of the ELF object that
compilation creates. Whenever functions were registered with
`CodeMemory` this would also result in registering unwinding information
dynamically at runtime, which in the case of Unix, for example, would
dynamically created FDE/CIE entries on-the-fly.
Eventually I'd like to support compiling Wasmtime without Cranelift, but
this means that `UnwindInfo` wouldn't be easily available to decode into
and create unwinding information from. To solve this I've changed the
ELF object created to have the unwinding information encoded into it
ahead-of-time so loading code into memory no longer needs to create
unwinding tables. This change has two different implementations for
Windows/Unix:
* On Windows the implementation was much easier. The unwinding
information on Windows is already stored after the function itself in
the text section. This was actually slightly duplicated in object
building and in code memory allocation. Now the object building
continues to do the same, recording unwinding information after
functions, and code memory no longer manually tracks this.
Additionally Wasmtime will emit a special custom section in the object
file with unwinding information which is the list of
`RUNTIME_FUNCTION` structures that `RtlAddFunctionTable` expects. This
means that the object file has all the information precompiled into it
and registration at runtime is simply passing a few pointers around to
the runtime.
* Unix was a little bit more difficult than Windows. Today a `.eh_frame`
section is created on-the-fly with offsets in FDEs specified as the
absolute address that functions are loaded at. This absolute
address hindered the ability to precompile the FDE into the object
file itself. I've switched how addresses are encoded, though, to using
`DW_EH_PE_pcrel` which means that FDE addresses are now specified
relative to the FDE itself. This means that we can maintain a fixed
offset between the `.eh_frame` loaded in memory and the beginning of
code memory. When doing so this enables precompiling the `.eh_frame`
section into the object file and at runtime when loading an object no
further construction of unwinding information is needed.
The overall result of this commit is that unwinding information is no
longer stored in its cranelift-data-structure form on disk. This means
that this unwinding information format is only present during
compilation, which will make it that much easier to compile out
cranelift in the future.
This commit also significantly refactors `CodeMemory` since the way
unwinding information is handled is not much different from before.
Previously `CodeMemory` was suitable for incrementally adding more and
more functions to it, but nowadays a `CodeMemory` either lives per
module (in which case all functions are known up front) or it's created
once-per-`Func::new` with two trampolines. In both cases we know all
functions up front so the functionality of incrementally adding more and
more segments is no longer needed. This commit removes the ability to
add a function-at-a-time in `CodeMemory` and instead it can now only
load objects in their entirety. A small helper function is added to
build a small object file for trampolines in `Func::new` to handle
allocation there.
Finally, this commit also folds the `wasmtime-obj` crate directly into
the `wasmtime-cranelift` crate and its builder structure to be more
amenable to this strategy of managing unwinding tables.
It is not intentional to have any real functional change as a result of
this commit. This might accelerate loading a module from cache slightly
since less work is needed to manage the unwinding information, but
that's just a side benefit from the main goal of this commit which is to
remove the dependence on cranelift unwinding information being available
at runtime.
* Remove isa reexport from wasmtime-environ
* Trim down reexports of `cranelift-codegen`
Remove everything non-essential so that only the bits which will need to
be refactored out of cranelift remain.
* Fix debug tests
* Review comments
* Update wasm-smith to 0.7.0
* Canonicalize NaN with wasm-smith for differential fuzzing
This then also enables floating point executing in wasmi in addition to
the spec interpreter. With NaN canonicalization at the wasm level this
means that we should be producing deterministic results between Wasmtime
and these alternative implementations.
This commit started off by deleting the `cranelift_codegen::settings`
reexport in the `wasmtime-environ` crate and then basically played
whack-a-mole until everything compiled again. The main result of this is
that the `wasmtime-*` family of crates have generally less of a
dependency on the `TargetIsa` trait and type from Cranelift. While the
dependency isn't entirely severed yet this is at least a significant
start.
This commit is intended to be largely refactorings, no functional
changes are intended here. The refactorings are:
* A `CompilerBuilder` trait has been added to `wasmtime_environ` which
server as an abstraction used to create compilers and configure them
in a uniform fashion. The `wasmtime::Config` type now uses this
instead of cranelift-specific settings. The `wasmtime-jit` crate
exports the ability to create a compiler builder from a
`CompilationStrategy`, which only works for Cranelift right now. In a
cranelift-less build of Wasmtime this is expected to return a trait
object that fails all requests to compile.
* The `Compiler` trait in the `wasmtime_environ` crate has been souped
up with a number of methods that Wasmtime and other crates needed.
* The `wasmtime-debug` crate is now moved entirely behind the
`wasmtime-cranelift` crate.
* The `wasmtime-cranelift` crate is now only depended on by the
`wasmtime-jit` crate.
* Wasm types in `cranelift-wasm` no longer contain their IR type,
instead they only contain the `WasmType`. This is required to get
everything to align correctly but will also be required in a future
refactoring where the types used by `cranelift-wasm` will be extracted
to a separate crate.
* I moved around a fair bit of code in `wasmtime-cranelift`.
* Some gdb-specific jit-specific code has moved from `wasmtime-debug` to
`wasmtime-jit`.
* Move all trampoline compilation to `wasmtime-cranelift`
This commit moves compilation of all the trampolines used in wasmtime
behind the `Compiler` trait object to live in `wasmtime-cranelift`. The
long-term goal of this is to enable depending on cranelift *only* from
the `wasmtime-cranelift` crate, so by moving these dependencies we
should make that a little more flexible.
* Fix windows build
The WebAssembly spec interpreter is written in OCaml and the new crate
uses `ocaml-interop` along with a small OCaml wrapper to interpret Wasm
modules in-process. The build process for this crate is currently
Linux-specific: it requires several OCaml packages (e.g. `apt install -y
ocaml-nox ocamlbuild`) as well as `make`, `cp`, and `ar`.
* Enable simd fuzzing on oss-fuzz
This commit generally enables the simd feature while fuzzing, which
should affect almost all fuzzers. For fuzzers that just throw random
data at the wall and see what sticks, this means that they'll now be
able to throw simd-shaped data at the wall and have it stick. For
wasm-smith-based fuzzers this commit also updates wasm-smith to 0.6.0
which allows further configuring the `SwarmConfig` after generation,
notably allowing `instantiate-swarm` to generate modules using simd
using `wasm-smith`. This should much more reliably feed simd-related
things into the fuzzers.
Finally, this commit updates wasmtime to avoid usage of the general
`wasm_smith::Module` generator to instead use a Wasmtime-specific custom
default configuration which enables various features we have
implemented.
* Allow dummy table creation to fail
Tables might creation for imports may exceed the memory limit on the
store, which we'll want to gracefully recover from and not fail the
fuzzers.
* Bump the wasm-tools crates
Pulls in some updates here and there, mostly for updating crates to the
latest version to prepare for later memory64 work.
* Update lightbeam
sync test: show the dummy executor will trap (rather than panic) when a
future inside it pends.
async test: show that the executor is hooked up to a future that pends
for a trivial amount of time.
this adds tokio to the dev-dependencies of wiggle, it shouldn't end up
increasing the build burden for the project as a whole since its already
a dev-dependency.
* Port wasi-common to io-lifetimes.
This ports wasi-common from unsafe-io to io-lifetimes.
Ambient authority is now indicated via calls to `ambient_authority()`
from the ambient-authority crate, rather than using `unsafe` blocks.
The `GetSetFdFlags::set_fd_flags` function is now split into two phases,
to simplify lifetimes in implementations which need to close and re-open
the underlying file.
* Use posish for errno values instead of libc.
This eliminates one of the few remaining direct libc dependencies.
* Port to posish::io::poll.
Use posish::io::poll instead of calling libc directly. This factors out
more code from Wasmtime, and eliminates the need to manipulate raw file
descriptors directly.
And, this eliminates the last remaining direct dependency on libc in
wasi-common.
* Port wasi-c-api to io-lifetimes.
* Update to posish 0.16.0.
* Embeded NULs in filenames now get `EINVAL` instead of `EILSEQ`.
* Accept either `EILSEQ` or `EINVAL` for embedded NULs.
* Bump the nightly toolchain to 2021-07-12.
This fixes build errors on the semver crate, which as of this writing
builds with latest nightly and stable but not 2021-04-11, the old pinned
version.
* Have cap-std-sync re-export ambient_authority so that users get the same version.
* cranelift: Initial fuzzer implementation
* cranelift: Generate multiple test cases in fuzzer
* cranelift: Separate function generator in fuzzer
* cranelift: Insert random instructions in fuzzer
* cranelift: Rename gen_testcase
* cranelift: Implement div for unsigned values in interpreter
* cranelift: Run all test cases in fuzzer
* cranelift: Comment options in function_runner
* cranelift: Improve fuzzgen README.md
* cranelift: Fuzzgen remove unused variable
* cranelift: Fuzzer code style fixes
Thanks! @bjorn3
* cranelift: Fix nits in CLIF fuzzer
Thanks @cfallin!
* cranelift: Implement Arbitrary for TestCase
* cranelift: Remove gen_testcase
* cranelift: Move fuzzers to wasmtime fuzz directory
* cranelift: CLIF-Fuzzer ignore tests that produce traps
* cranelift: CLIF-Fuzzer create new fuzz target to validate generated testcases
* cranelift: Store clif-fuzzer config in a separate struct
* cranelift: Generate variables upfront per function
* cranelift: Prevent publishing of fuzzgen crate
* wasi-common: update wasi submodule
This updates the WASI submodule, pulling in changes to the witx crate,
now that there is a 0.9.1 version including some bug fixes. See
WebAssembly/WASI#434 for more information.
* wiggle: update witx dependencies
* publish: verify and vendor witx-cli
* adjust root workspace members
This commit removes some items from the root manifest's workspace
members array, and adds `witx-cli` to the root `workspace.exclude`
array.
The motivation for this stems from a cargo bug described in
rust-lang/cargo#6745: `workspace.exclude` does not work if it is nested
under a `workspace.members` path.
See WebAssembly/WASI#438 for the underlying change to the WASI submodule
which reorganized the `witx-cli` crate, and WebAssembly/WASI#398 for the
original PR introducing `witx-cli`.
See [this
comment](https://github.com/bytecodealliance/wasmtime/pull/3025#issuecomment-867741175)
for more details about the compilation errors, and failed alternative
approaches that necessitated this change.
N.B. This is not a functional change, these crates are still implicitly
workspace members as transitive dependencies, but this will allow us to
side-step the aforementioned cargo bug.
Co-Authored-By: Alex Crichton <alex@alexcrichton.com>
Co-authored-by: Alex Crichton <alex@alexcrichton.com>
* Add guard pages to the front of linear memories
This commit implements a safety feature for Wasmtime to place guard
pages before the allocation of all linear memories. Guard pages placed
after linear memories are typically present for performance (at least)
because it can help elide bounds checks. Guard pages before a linear
memory, however, are never strictly needed for performance or features.
The intention of a preceding guard page is to help insulate against bugs
in Cranelift or other code generators, such as CVE-2021-32629.
This commit adds a `Config::guard_before_linear_memory` configuration
option, defaulting to `true`, which indicates whether guard pages should
be present both before linear memories as well as afterwards. Guard
regions continue to be controlled by
`{static,dynamic}_memory_guard_size` methods.
The implementation here affects both on-demand allocated memories as
well as the pooling allocator for memories. For on-demand memories this
adjusts the size of the allocation as well as adjusts the calculations
for the base pointer of the wasm memory. For the pooling allocator this
will place a singular extra guard region at the very start of the
allocation for memories. Since linear memories in the pooling allocator
are contiguous every memory already had a preceding guard region in
memory, it was just the previous memory's guard region afterwards. Only
the first memory needed this extra guard.
I've attempted to write some tests to help test all this, but this is
all somewhat tricky to test because the settings are pretty far away
from the actual behavior. I think, though, that the tests added here
should help cover various use cases and help us have confidence in
tweaking the various `Config` settings beyond their defaults.
Note that this also contains a semantic change where
`InstanceLimits::memory_reservation_size` has been removed. Instead this
field is now inferred from the `static_memory_maximum_size` and guard
size settings. This should hopefully remove some duplication in these
settings, canonicalizing on the guard-size/static-size settings as the
way to control memory sizes and virtual reservations.
* Update config docs
* Fix a typo
* Fix benchmark
* Fix wasmtime-runtime tests
* Fix some more tests
* Try to fix uffd failing test
* Review items
* Tweak 32-bit defaults
Makes the pooling allocator a bit more reasonable by default on 32-bit
with these settings.
* Add support for processor features (including auto-detection).
* Move base architecture set requirement back to z14.
* Add z15 feature sets and re-enable z15-specific code generation
when required features are available.
* Update wasm-tools crates
This brings in recent updates, notably including more improvements to
wasm-smith which will hopefully help exercise non-trapping wasm more.
* Fix some wat
Implement Wasmtime's new API as designed by RFC 11. This is quite a large commit which has had lots of discussion externally, so for more information it's best to read the RFC thread and the PR thread.
I had no idea this was still in the repository, much less building!
There are much different ways to use wasmtime in Rust nowadays, such as
the `wasmtime` crate!
Previously the inclusion of the `criterion` crate had brought in a
transitive dependency to `cast`, which used old versions of several
libraries. Now that https://github.com/japaric/cast.rs/pull/26 is merged
and a new version published, we can update `cast` and remove the
cargo-deny rules for the duplicated, older versions.
This adds benchmarks around module instantiation using criterion.
Both the default (i.e. on-demand) and pooling allocators are tested
sequentially and in parallel using a thread pool.
Instantiation is tested with an empty module, a module with a single page
linear memory, a larger linear memory with a data initializer, and a "hello
world" Rust WASI program.
This change adds a criterion-enabled benchmark, x64-evex-encoding, to
compare the performance of the builder pattern used to encode EVEX
instructions in the new x64 backend against the function pattern
used to encode EVEX instructions in the legacy x86 backend. At face
value, the results imply that the builder pattern is faster, but no
efforts were made to analyze and optimize these approaches further.
Dan Gohman
Nick Fitzgerald
Alex Crichton
Andrew Brown
Chris Fallin
Qiu Wenbo
Pat Hickey
Benjamin Bouvier
Afonso Bordado
katelyn martin
Ulrich Weigand
bjorn3
Olivier Lemasle
Chris Fallin
Peter Huene