Skip to content

Fix running enter/exit hooks on start functions #3001

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
alexcrichton merged 1 commit into from
Jun 21, 2021
Merged

Fix running enter/exit hooks on start functions #3001

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
181 changes: 97 additions & 84 deletions crates/wasmtime/src/func.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
use crate::store::{StoreData, StoreOpaque, StoreOpaqueSend, Stored};
use crate::store::{StoreData, StoreInnermost, StoreOpaque, Stored};
use crate::{
AsContext, AsContextMut, Engine, Extern, FuncType, Instance, InterruptHandle, StoreContext,
StoreContextMut, Trap, Val, ValType,
Expand Down Expand Up @@ -681,10 +681,7 @@ impl Func {
"must use `call_async` when async support is enabled on the config",
);
let my_ty = self.ty(&store);
store.as_context_mut().0.exiting_native_hook()?;
let r = self.call_impl(&mut store.as_context_mut().opaque(), my_ty, params);
store.as_context_mut().0.entering_native_hook()?;
r
self.call_impl(&mut store.as_context_mut(), my_ty, params)
}

/// Invokes this function with the `params` given, returning the results
Expand Down Expand Up @@ -719,105 +716,110 @@ impl Func {
where
T: Send,
{
let my_ty = self.ty(&store);
store.as_context_mut().0.exiting_native_hook()?;
let r = self
._call_async(store.as_context_mut().opaque_send(), my_ty, params)
.await;
store.as_context_mut().0.entering_native_hook()?;
r
}

#[cfg(feature = "async")]
async fn _call_async(
&self,
mut store: StoreOpaqueSend<'_>,
my_ty: FuncType,
params: &[Val],
) -> Result<Box<[Val]>> {
let mut store = store.as_context_mut();
assert!(
store.async_support(),
store.0.async_support(),
"cannot use `call_async` without enabling async support in the config",
);
let my_ty = self.ty(&store);
let result = store
.on_fiber(|store| self.call_impl(store, my_ty, params))
.await??;
Ok(result)
}

fn call_impl(
fn call_impl<T>(
&self,
store: &mut StoreOpaque<'_>,
store: &mut StoreContextMut<'_, T>,
my_ty: FuncType,
params: &[Val],
) -> Result<Box<[Val]>> {
let data = &store[self.0];
let trampoline = data.trampoline();
let anyfunc = data.export().anyfunc;
// We need to perform a dynamic check that the arguments given to us
// match the signature of this function and are appropriate to pass to
// this function. This involves checking to make sure we have the right
// number and types of arguments as well as making sure everything is
// from the same `Store`.
if my_ty.params().len() != params.len() {
bail!(
"expected {} arguments, got {}",
my_ty.params().len(),
params.len()
);
}

let mut values_vec = vec![0; max(params.len(), my_ty.results().len())];

// Store the argument values into `values_vec`.
let param_tys = my_ty.params();
for ((arg, slot), ty) in params.iter().cloned().zip(&mut values_vec).zip(param_tys) {
if arg.ty() != ty {
bail!(
"argument type mismatch: found {} but expected {}",
arg.ty(),
ty
);
}
if !arg.comes_from_same_store(store) {
bail!("cross-`Store` values are not currently supported");
}
unsafe {
arg.write_value_to(store, slot);
}
}
let mut values_vec = write_params(&mut store.as_context_mut().opaque(), &my_ty, params)?;

// Call the trampoline.
unsafe {
let anyfunc = anyfunc.as_ref();
let data = &store.0.store_data()[self.0];
let trampoline = data.trampoline();
let anyfunc = data.export().anyfunc;
invoke_wasm_and_catch_traps(store, |callee| {
trampoline(
anyfunc.vmctx,
(*anyfunc.as_ptr()).vmctx,
callee,
anyfunc.func_ptr.as_ptr(),
(*anyfunc.as_ptr()).func_ptr.as_ptr(),
values_vec.as_mut_ptr(),
)
})?;
}

// Load the return values out of `values_vec`.
let mut results = Vec::with_capacity(my_ty.results().len());
for (index, ty) in my_ty.results().enumerate() {
unsafe {
let ptr = values_vec.as_ptr().add(index);
results.push(Val::read_value_from(store, ptr, ty));
return Ok(read_results(
&mut store.as_context_mut().opaque(),
&my_ty,
&values_vec,
));

fn write_params(
store: &mut StoreOpaque<'_>,
ty: &FuncType,
params: &[Val],
) -> Result<Vec<u128>> {
// We need to perform a dynamic check that the arguments given to us
// match the signature of this function and are appropriate to pass to
// this function. This involves checking to make sure we have the right
// number and types of arguments as well as making sure everything is
// from the same `Store`.
if ty.params().len() != params.len() {
bail!(
"expected {} arguments, got {}",
ty.params().len(),
params.len()
);
}

let mut values_vec = vec![0; max(params.len(), ty.results().len())];

// Store the argument values into `values_vec`.
let param_tys = ty.params();
for ((arg, slot), ty) in params.iter().cloned().zip(&mut values_vec).zip(param_tys) {
if arg.ty() != ty {
bail!(
"argument type mismatch: found {} but expected {}",
arg.ty(),
ty
);
}
if !arg.comes_from_same_store(store) {
bail!("cross-`Store` values are not currently supported");
}
unsafe {
arg.write_value_to(store, slot);
}
}

Ok(values_vec)
}

Ok(results.into())
fn read_results(
store: &mut StoreOpaque<'_>,
ty: &FuncType,
values_vec: &[u128],
) -> Box<[Val]> {
let mut results = Vec::with_capacity(ty.results().len());
for (index, ty) in ty.results().enumerate() {
unsafe {
let ptr = &values_vec[index];
results.push(Val::read_value_from(store, ptr, ty));
}
}
results.into()
}
}

#[inline]
pub(crate) fn caller_checked_anyfunc(
&self,
store: &StoreOpaque,
store: &StoreInnermost,
) -> NonNull<VMCallerCheckedAnyfunc> {
store[self.0].export().anyfunc
store.store_data()[self.0].export().anyfunc
}

pub(crate) unsafe fn from_wasmtime_function(
Expand Down Expand Up @@ -1033,28 +1035,39 @@ impl Func {
///
/// The `closure` provided receives a default "callee" `VMContext` parameter it
/// can pass to the called wasm function, if desired.
#[inline]
pub(crate) fn invoke_wasm_and_catch_traps(
store: &mut StoreOpaque<'_>,
pub(crate) fn invoke_wasm_and_catch_traps<T>(
store: &mut StoreContextMut<'_, T>,
closure: impl FnMut(*mut VMContext),
) -> Result<(), Trap> {
unsafe {
let exit = if store.externref_activations_table().stack_canary().is_some() {
let exit = if store
.0
.externref_activations_table()
.stack_canary()
.is_some()
{
false
} else {
enter_wasm(store)?;
true
};

if let Err(trap) = store.0.exiting_native_hook() {
if exit {
exit_wasm(store);
}
return Err(trap);
}
let result = wasmtime_runtime::catch_traps(
store.vminterrupts(),
store.signal_handler(),
store.default_callee(),
store.0.vminterrupts(),
store.0.signal_handler(),
store.0.default_callee(),
closure,
);
if exit {
exit_wasm(store);
}
store.0.entering_native_hook()?;
result.map_err(Trap::from_runtime)
}
}
Expand All @@ -1076,8 +1089,7 @@ pub(crate) fn invoke_wasm_and_catch_traps(
///
/// This function may fail if the the stack limit can't be set because an
/// interrupt already happened.
#[inline]
fn enter_wasm(store: &mut StoreOpaque<'_>) -> Result<(), Trap> {
fn enter_wasm<T>(store: &mut StoreContextMut<'_, T>) -> Result<(), Trap> {
let stack_pointer = psm::stack_pointer() as usize;

// Determine the stack pointer where, after which, any wasm code will
Expand Down Expand Up @@ -1107,7 +1119,7 @@ fn enter_wasm(store: &mut StoreOpaque<'_>) -> Result<(), Trap> {
// synchronize with any other memory it's hoped that the choice of `Relaxed`
// here should be correct for our use case.
let wasm_stack_limit = stack_pointer - store.engine().config().max_wasm_stack;
let interrupts = store.interrupts();
let interrupts = store.0.interrupts();
match interrupts.stack_limit.swap(wasm_stack_limit, Relaxed) {
wasmtime_environ::INTERRUPTED => {
// This means that an interrupt happened before we actually
Expand All @@ -1123,18 +1135,19 @@ fn enter_wasm(store: &mut StoreOpaque<'_>) -> Result<(), Trap> {
n => debug_assert_eq!(usize::max_value(), n),
}
store
.0
.externref_activations_table()
.set_stack_canary(Some(stack_pointer));

Ok(())
}

#[inline]
fn exit_wasm(store: &mut StoreOpaque<'_>) {
store.externref_activations_table().set_stack_canary(None);
fn exit_wasm<T>(store: &mut StoreContextMut<'_, T>) {
store.0.externref_activations_table().set_stack_canary(None);

// see docs above for why this uses `Relaxed`
store
.0
.interrupts()
.stack_limit
.store(usize::max_value(), Relaxed);
Expand Down
37 changes: 19 additions & 18 deletions crates/wasmtime/src/func/typed.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
use super::{invoke_wasm_and_catch_traps, HostAbi};
use crate::store::StoreOpaque;
use crate::{AsContextMut, ExternRef, Func, Trap, ValType};
use crate::{AsContextMut, ExternRef, Func, StoreContextMut, Trap, ValType};
use anyhow::{bail, Result};
use std::marker;
use std::mem::{self, MaybeUninit};
Expand Down Expand Up @@ -71,15 +71,12 @@ where
/// This function will panic if it is called when the underlying [`Func`] is
/// connected to an asynchronous store.
pub fn call(&self, mut store: impl AsContextMut, params: Params) -> Result<Results, Trap> {
store.as_context_mut().0.exiting_native_hook()?;
let mut store_opaque = store.as_context_mut().opaque();
let mut store = store.as_context_mut();
assert!(
!store_opaque.async_support(),
!store.0.async_support(),
"must use `call_async` with async stores"
);
let r = unsafe { self._call(&mut store_opaque, params) };
store.as_context_mut().0.entering_native_hook()?;
r
unsafe { self._call(&mut store, params) }
}

/// Invokes this WebAssembly function with the specified parameters.
Expand All @@ -103,24 +100,25 @@ where
where
T: Send,
{
store.as_context_mut().0.exiting_native_hook()?;
let mut store_opaque = store.as_context_mut().opaque_send();
let mut store = store.as_context_mut();
assert!(
store_opaque.async_support(),
store.0.async_support(),
"must use `call` with non-async stores"
);
let r = store_opaque
store
.on_fiber(|store| unsafe { self._call(store, params) })
.await?;
store.as_context_mut().0.entering_native_hook()?;
r
.await?
}

unsafe fn _call(&self, store: &mut StoreOpaque<'_>, params: Params) -> Result<Results, Trap> {
unsafe fn _call<T>(
&self,
store: &mut StoreContextMut<'_, T>,
params: Params,
) -> Result<Results, Trap> {
// Validate that all runtime values flowing into this store indeed
// belong within this store, otherwise it would be unsafe for store
// values to cross each other.
let params = match params.into_abi(store) {
let params = match params.into_abi(&mut store.as_context_mut().opaque()) {
Some(abi) => abi,
None => {
return Err(Trap::new(
Expand All @@ -135,7 +133,7 @@ where
// other side of a C++ shim, so it can never be inlined enough to make
// the memory go away, so the size matters here for performance.
let mut captures = (
self.func.caller_checked_anyfunc(store),
self.func.caller_checked_anyfunc(store.0),
MaybeUninit::uninit(),
params,
false,
Expand All @@ -156,7 +154,10 @@ where
let (_, ret, _, returned) = captures;
debug_assert_eq!(result.is_ok(), returned);
result?;
Ok(Results::from_abi(store, ret.assume_init()))
Ok(Results::from_abi(
&mut store.as_context_mut().opaque(),
ret.assume_init(),
))
}
}

Expand Down
Loading