Merge branch 'master' into feat-runtime-core-wasm-extern-type-macros

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## **[Unreleased]**
 
+- [#1228](https://github.com/wasmerio/wasmer/pull/1228) Singlepass cleanup: Resolve several FIXMEs and remove protect_unix.
 - [#1218](https://github.com/wasmerio/wasmer/pull/1218) Enable Cranelift verifier in debug mode. Fix bug with table indices being the wrong type.
 - [#787](https://github.com/wasmerio/wasmer/pull/787) New crate `wasmer-interface-types` to implement WebAssembly Interface Types.
 - [#1213](https://github.com/wasmerio/wasmer/pull/1213) Fixed WASI `fdstat` to detect `isatty` properly.

lib/interface-types/README.md

@@ -0,0 +1,32 @@
+<p align="center">
+  <a href="https://wasmer.io" target="_blank" rel="noopener noreferrer">
+    <img width="300" src="https://raw.githubusercontent.com/wasmerio/wasmer/master/logo.png" alt="Wasmer logo">
+  </a>
+</p>
+
+<p align="center">
+  <a href="https://dev.azure.com/wasmerio/wasmer/_build/latest?definitionId=3&branchName=master">
+    <img src="https://img.shields.io/azure-devops/build/wasmerio/wasmer/3.svg?style=flat-square" alt="Build Status">
+  </a>
+  <a href="https://github.com/wasmerio/wasmer/blob/master/LICENSE">
+    <img src="https://img.shields.io/github/license/wasmerio/wasmer.svg?style=flat-square" alt="License">
+  </a>
+  <a href="https://spectrum.chat/wasmer">
+    <img src="https://withspectrum.github.io/badge/badge.svg" alt="Join the Wasmer Community">
+  </a>
+  <a href="https://crates.io/crates/wasmer-interface-types">
+    <img src="https://img.shields.io/crates/d/wasmer-interface-types.svg?style=flat-square" alt="Number of downloads from crates.io">
+  </a>
+  <a href="https://docs.rs/wasmer-interface-types">
+    <img src="https://docs.rs/wasmer-interface-types/badge.svg" alt="Read our API documentation">
+  </a>
+</p>
+
+# Wasmer Interface Types
+
+Wasmer is a standalone JIT WebAssembly runtime, aiming to be fully
+compatible with WASI, Emscripten, Rust and Go. [Learn
+more](https://github.com/wasmerio/wasmer).
+
+This crate is an implementation of [the living WebAssembly Interface
+Types standard](https://github.com/WebAssembly/interface-types).

lib/runtime-core/src/typed_func.rs

@@ -310,6 +310,7 @@ macro_rules! impl_traits {
         where
             $( $x: WasmExternType ),*;
 
+        #[allow(unused_parens)]
         impl< $( $x ),* > WasmTypeList for ( $( $x ),* )
         where
             $( $x: WasmExternType ),*
@@ -380,6 +381,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl< $( $x, )* Rets, Trap, FN > ExternalFunction<ExplicitVmCtx, ( $( $x ),* ), Rets> for FN
         where
             $( $x: WasmExternType, )*
@@ -495,6 +497,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl< $( $x, )* Rets, Trap, FN > ExternalFunction<ImplicitVmCtx, ( $( $x ),* ), Rets> for FN
         where
             $( $x: WasmExternType, )*
@@ -607,6 +610,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl<'a $( , $x )*, Rets> Func<'a, ( $( $x ),* ), Rets, Wasm>
         where
             $( $x: WasmExternType, )*

lib/singlepass-backend/src/codegen_x64.rs

@@ -3,7 +3,6 @@
 
 use crate::emitter_x64::*;
 use crate::machine::*;
-use crate::protect_unix;
 #[cfg(target_arch = "aarch64")]
 use dynasmrt::aarch64::Assembler;
 #[cfg(target_arch = "x86_64")]
@@ -28,7 +27,7 @@ use wasmer_runtime_core::{
     },
     cache::{Artifact, Error as CacheError},
     codegen::*,
-    fault::raw::register_preservation_trampoline,
+    fault::{self, raw::register_preservation_trampoline},
     loader::CodeMemory,
     memory::MemoryType,
     module::{ModuleInfo, ModuleInner},
@@ -369,6 +368,11 @@ impl RunnableModule for X64ExecutionContext {
     }
 
     fn get_trampoline(&self, _: &ModuleInfo, sig_index: SigIndex) -> Option<Wasm> {
+        // Correctly unwinding from `catch_unsafe_unwind` on hardware exceptions depends
+        // on the signal handlers being installed. Here we call `ensure_sighandler` "statically"
+        // outside `invoke()`.
+        fault::ensure_sighandler();
+
         unsafe extern "C" fn invoke(
             _trampoline: Trampoline,
             ctx: *mut vm::Ctx,
@@ -383,8 +387,9 @@ impl RunnableModule for X64ExecutionContext {
             let args =
                 slice::from_raw_parts(args, num_params_plus_one.unwrap().as_ptr() as usize - 1);
 
-            let ret = match protect_unix::call_protected(
+            let ret = match fault::catch_unsafe_unwind(
                 || {
+                    // Puts the arguments onto the stack and calls Wasm entry.
                     #[cfg(target_arch = "x86_64")]
                     {
                         let args_reverse: SmallVec<[u64; 8]> = args.iter().cloned().rev().collect();
@@ -395,6 +400,9 @@ impl RunnableModule for X64ExecutionContext {
                             func.as_ptr(),
                         )
                     }
+
+                    // FIXME: Currently we are doing a hack here to convert between native aarch64 and
+                    // "emulated" x86 ABIs. Ideally, this should be done using handwritten assembly.
                     #[cfg(target_arch = "aarch64")]
                     {
                         struct CallCtx<'a> {
@@ -519,7 +527,7 @@ impl RunnableModule for X64ExecutionContext {
                     true
                 }
                 Err(err) => {
-                    *error_out = Some(err.0);
+                    *error_out = Some(err);
                     false
                 }
             };
@@ -545,8 +553,7 @@ impl RunnableModule for X64ExecutionContext {
     }
 
     unsafe fn do_early_trap(&self, data: Box<dyn Any + Send>) -> ! {
-        protect_unix::TRAP_EARLY_DATA.with(|x| x.set(Some(data)));
-        protect_unix::trigger_trap();
+        fault::begin_unsafe_unwind(data);
     }
 
     fn get_code(&self) -> Option<&[u8]> {
@@ -1686,14 +1693,11 @@ impl X64FunctionCode {
                 Location::GPR(GPR::RSP),
             );
 
-            // FIXME: Possible dynasm bug. This is a workaround.
-            // Using RSP as the source/destination operand of a `mov` instruction produces invalid code.
-            a.emit_mov(Size::S64, Location::GPR(GPR::RSP), Location::GPR(GPR::RCX));
             for (i, r) in used_xmms.iter().enumerate() {
                 a.emit_mov(
                     Size::S64,
                     Location::XMM(*r),
-                    Location::Memory(GPR::RCX, (i * 8) as i32),
+                    Location::Memory(GPR::RSP, (i * 8) as i32),
                 );
             }
             for r in used_xmms.iter().rev() {
@@ -1771,37 +1775,26 @@ impl X64FunctionCode {
                         }
                     }
                     match *param {
-                        // Dynasm bug: RSP in memory operand does not work
-                        Location::Imm64(_) | Location::XMM(_) => {
+                        Location::Imm64(_) => {
+                            // Dummy value slot to be filled with `mov`.
+                            a.emit_push(Size::S64, Location::GPR(GPR::RAX));
+
+                            // Use R10 as the temporary register here, since it is callee-saved and not
+                            // used by the callback `cb`.
+                            a.emit_mov(Size::S64, *param, Location::GPR(GPR::R10));
                             a.emit_mov(
                                 Size::S64,
-                                Location::GPR(GPR::RAX),
-                                Location::XMM(XMM::XMM0),
-                            );
-                            a.emit_mov(
-                                Size::S64,
-                                Location::GPR(GPR::RCX),
-                                Location::XMM(XMM::XMM1),
-                            );
-                            a.emit_sub(Size::S64, Location::Imm32(8), Location::GPR(GPR::RSP));
-                            a.emit_mov(Size::S64, Location::GPR(GPR::RSP), Location::GPR(GPR::RCX));
-                            a.emit_mov(Size::S64, *param, Location::GPR(GPR::RAX));
-                            a.emit_mov(
-                                Size::S64,
-                                Location::GPR(GPR::RAX),
-                                Location::Memory(GPR::RCX, 0),
-                            );
-                            a.emit_mov(
-                                Size::S64,
-                                Location::XMM(XMM::XMM0),
-                                Location::GPR(GPR::RAX),
-                            );
-                            a.emit_mov(
-                                Size::S64,
-                                Location::XMM(XMM::XMM1),
-                                Location::GPR(GPR::RCX),
+                                Location::GPR(GPR::R10),
+                                Location::Memory(GPR::RSP, 0),
                             );
                         }
+                        Location::XMM(_) => {
+                            // Dummy value slot to be filled with `mov`.
+                            a.emit_push(Size::S64, Location::GPR(GPR::RAX));
+
+                            // XMM registers can be directly stored to memory.
+                            a.emit_mov(Size::S64, *param, Location::Memory(GPR::RSP, 0));
+                        }
                         _ => a.emit_push(Size::S64, *param),
                     }
                 }
@@ -1873,12 +1866,10 @@ impl X64FunctionCode {
 
         // Restore XMMs.
         if used_xmms.len() > 0 {
-            // FIXME: Possible dynasm bug. This is a workaround.
-            a.emit_mov(Size::S64, Location::GPR(GPR::RSP), Location::GPR(GPR::RDX));
             for (i, r) in used_xmms.iter().enumerate() {
                 a.emit_mov(
                     Size::S64,
-                    Location::Memory(GPR::RDX, (i * 8) as i32),
+                    Location::Memory(GPR::RSP, (i * 8) as i32),
                     Location::XMM(*r),
                 );
             }

lib/singlepass-backend/src/lib.rs

@@ -40,7 +40,6 @@ extern crate smallvec;
 mod codegen_x64;
 mod emitter_x64;
 mod machine;
-pub mod protect_unix;
 #[cfg(target_arch = "aarch64")]
 mod translator_aarch64;
 

lib/singlepass-backend/src/protect_unix.rs

@@ -1,49 +0,0 @@
-//! Installing signal handlers allows us to handle traps and out-of-bounds memory
-//! accesses that occur when runniing WebAssembly.
-//!
-//! This code is inspired by: https://github.com/pepyakin/wasmtime/commit/625a2b6c0815b21996e111da51b9664feb174622
-//!
-//! When a WebAssembly module triggers any traps, we perform recovery here.
-//!
-//! This module uses TLS (thread-local storage) to track recovery information. Since the four signals we're handling
-//! are very special, the async signal unsafety of Rust's TLS implementation generally does not affect the correctness here
-//! unless you have memory unsafety elsewhere in your code.
-//!
-use std::any::Any;
-use std::cell::Cell;
-use wasmer_runtime_core::codegen::BreakpointMap;
-use wasmer_runtime_core::fault::{begin_unsafe_unwind, catch_unsafe_unwind, ensure_sighandler};
-
-thread_local! {
-    pub static TRAP_EARLY_DATA: Cell<Option<Box<dyn Any + Send>>> = Cell::new(None);
-}
-
-pub unsafe fn trigger_trap() -> ! {
-    begin_unsafe_unwind(Box::new(()));
-}
-
-pub struct CallProtError(pub Box<dyn Any + Send>);
-
-pub fn call_protected<T>(
-    f: impl FnOnce() -> T,
-    breakpoints: Option<BreakpointMap>,
-) -> Result<T, CallProtError> {
-    ensure_sighandler();
-    unsafe {
-        let ret = catch_unsafe_unwind(|| f(), breakpoints);
-        match ret {
-            Ok(x) => Ok(x),
-            Err(e) => Err(CallProtError(
-                if let Some(data) = TRAP_EARLY_DATA.with(|cell| cell.replace(None)) {
-                    data
-                } else {
-                    e
-                },
-            )),
-        }
-    }
-}
-
-pub unsafe fn throw(payload: Box<dyn Any + Send>) -> ! {
-    begin_unsafe_unwind(payload);
-}