Implemented protected call and floating point traps; passing all spectests!

lib/dynasm-backend/Cargo.toml

@@ -14,3 +14,5 @@ dynasm = "0.3.0"
 dynasmrt = "0.3.1"
 lazy_static = "1.2.0"
 byteorder = "1"
+nix = "0.13.0"
+libc = "0.2.49"

lib/dynasm-backend/src/codegen.rs

@@ -9,6 +9,7 @@ use wasmer_runtime_core::{
 use wasmparser::{Operator, Type as WpType};
 
 pub trait ModuleCodeGenerator<FCG: FunctionCodeGenerator, PC: ProtectedCaller, FR: FuncResolver> {
+    fn check_precondition(&mut self, module_info: &ModuleInfo) -> Result<(), CodegenError>;
     fn next_function(&mut self) -> Result<&mut FCG, CodegenError>;
     fn finalize(self, module_info: &ModuleInfo) -> Result<(PC, FR), CodegenError>;
     fn feed_signatures(

lib/dynasm-backend/src/codegen_x64.rs

@@ -24,6 +24,7 @@ use wasmer_runtime_core::{
     vm::{self, ImportBacking, LocalGlobal, LocalTable, LocalMemory},
 };
 use wasmparser::{Operator, Type as WpType};
+use crate::protect_unix;
 
 thread_local! {
     static CURRENT_EXECUTION_CONTEXT: RefCell<Vec<*const X64ExecutionContext>> = RefCell::new(Vec::new());
@@ -384,6 +385,7 @@ impl ProtectedCaller for X64ExecutionContext {
         CURRENT_EXECUTION_CONTEXT.with(|x| x.borrow_mut().push(self));
 
         let ret = unsafe {
+            protect_unix::call_protected(|| {
                 CALL_WASM(
                     param_buf.as_ptr(),
                     param_buf.len(),
@@ -391,10 +393,13 @@ impl ProtectedCaller for X64ExecutionContext {
                     memory_base,
                     _vmctx,
                 )
+            })
         };
 
         CURRENT_EXECUTION_CONTEXT.with(|x| x.borrow_mut().pop().unwrap());
 
+        let ret = ret?;
+
         Ok(if let Some(ty) = return_ty {
             vec![match ty {
                 WpType::I32 => Value::I32(ret as i32),
@@ -524,6 +529,19 @@ impl X64ModuleCodeGenerator {
 }
 
 impl ModuleCodeGenerator<X64FunctionCode, X64ExecutionContext, X64RuntimeResolver> for X64ModuleCodeGenerator {
+    fn check_precondition(&mut self, module_info: &ModuleInfo) -> Result<(), CodegenError> {
+        for mem in module_info.memories.iter().map(|(_, v)| v).chain(module_info.imported_memories.iter().map(|(_, v)| &v.1)) {
+            match mem.memory_type() {
+                MemoryType::Dynamic => return Err(CodegenError {
+                    message: "dynamic memory isn't supported yet"
+                }),
+                _ => {}
+            }
+        }
+
+        Ok(())
+    }
+
     fn next_function(&mut self) -> Result<&mut X64FunctionCode, CodegenError> {
         let (mut assembler, mut function_labels, br_table_data) = match self.functions.last_mut() {
             Some(x) => (
@@ -1428,6 +1446,98 @@ impl X64FunctionCode {
         Ok(())
     }
 
+    fn emit_f32_int_conv_check(
+        assembler: &mut Assembler,
+        reg: Register,
+        lower_bound: f32,
+        upper_bound: f32,
+    ) {
+        let lower_bound = f32::to_bits(lower_bound);
+        let upper_bound = f32::to_bits(upper_bound);
+
+        dynasm!(
+            assembler
+            ; movq xmm5, r15
+
+            // underflow
+            ; movd xmm1, Rd(reg as u8)
+            ; mov r15d, lower_bound as i32
+            ; movd xmm2, r15d
+            ; vcmpltss xmm0, xmm1, xmm2
+            ; movd r15d, xmm0
+            ; cmp r15d, 1
+            ; je >trap
+
+            // overflow
+            ; mov r15d, upper_bound as i32
+            ; movd xmm2, r15d
+            ; vcmpgtss xmm0, xmm1, xmm2
+            ; movd r15d, xmm0
+            ; cmp r15d, 1
+            ; je >trap
+
+            // NaN
+            ; vcmpeqss xmm0, xmm1, xmm1
+            ; movd r15d, xmm0
+            ; cmp r15d, 0
+            ; je >trap
+
+            ; movq r15, xmm5
+            ; jmp >ok
+
+            ; trap:
+            ; ud2
+
+            ; ok:
+        );
+    }
+
+    fn emit_f64_int_conv_check(
+        assembler: &mut Assembler,
+        reg: Register,
+        lower_bound: f64,
+        upper_bound: f64,
+    ) {
+        let lower_bound = f64::to_bits(lower_bound);
+        let upper_bound = f64::to_bits(upper_bound);
+
+        dynasm!(
+            assembler
+            ; movq xmm5, r15
+
+            // underflow
+            ; movq xmm1, Rq(reg as u8)
+            ; mov r15, QWORD lower_bound as i64
+            ; movq xmm2, r15
+            ; vcmpltsd xmm0, xmm1, xmm2
+            ; movd r15d, xmm0
+            ; cmp r15d, 1
+            ; je >trap
+
+            // overflow
+            ; mov r15, QWORD upper_bound as i64
+            ; movq xmm2, r15
+            ; vcmpgtsd xmm0, xmm1, xmm2
+            ; movd r15d, xmm0
+            ; cmp r15d, 1
+            ; je >trap
+
+            // NaN
+            ; vcmpeqsd xmm0, xmm1, xmm1
+            ; movd r15d, xmm0
+            ; cmp r15d, 0
+            ; je >trap
+
+            ; movq r15, xmm5
+            ; jmp >ok
+
+            ; trap:
+            ; ud2
+
+            ; ok:
+        );
+    }
+
     fn emit_native_call_trampoline<A: Copy + Sized, B: Copy + Sized>(
         assembler: &mut Assembler,
         target: unsafe extern "C" fn(
@@ -4137,11 +4247,17 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     WpType::F32
                 )?;
             }
-            Operator::I32TruncUF32 | Operator::I32TruncSF32 => {
+            Operator::I32TruncUF32 => {
                 Self::emit_unop(
                     assembler,
                     &mut self.value_stack,
                     |assembler, value_stack, reg| {
+                        Self::emit_f32_int_conv_check(
+                            assembler,
+                            reg,
+                            -1.0,
+                            4294967296.0,
+                        );
                         dynasm!(
                             assembler
                             ; movd xmm1, Rd(reg as u8)
@@ -4153,11 +4269,61 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     WpType::I32
                 )?;
             }
-            Operator::I64TruncUF32 | Operator::I64TruncSF32 => {
+            Operator::I32TruncSF32 => {
                 Self::emit_unop(
                     assembler,
                     &mut self.value_stack,
                     |assembler, value_stack, reg| {
+                        Self::emit_f32_int_conv_check(
+                            assembler,
+                            reg,
+                            -2147483904.0,
+                            2147483648.0
+                        );
+                        dynasm!(
+                            assembler
+                            ; movd xmm1, Rd(reg as u8)
+                            ; roundss xmm1, xmm1, 3
+                            ; cvtss2si Rd(reg as u8), xmm1
+                        );
+                    },
+                    WpType::F32,
+                    WpType::I32
+                )?;
+            }
+            Operator::I64TruncUF32 => {
+                Self::emit_unop(
+                    assembler,
+                    &mut self.value_stack,
+                    |assembler, value_stack, reg| {
+                        Self::emit_f32_int_conv_check(
+                            assembler,
+                            reg,
+                            -1.0,
+                            18446744073709551616.0,
+                        );
+                        dynasm!(
+                            assembler
+                            ; movd xmm1, Rd(reg as u8)
+                            ; roundss xmm1, xmm1, 3
+                            ; cvtss2si Rq(reg as u8), xmm1
+                        );
+                    },
+                    WpType::F32,
+                    WpType::I64
+                )?;
+            }
+            Operator::I64TruncSF32 => {
+                Self::emit_unop(
+                    assembler,
+                    &mut self.value_stack,
+                    |assembler, value_stack, reg| {
+                        Self::emit_f32_int_conv_check(
+                            assembler,
+                            reg,
+                            -9223373136366403584.0,
+                            9223372036854775808.0,
+                        );
                         dynasm!(
                             assembler
                             ; movd xmm1, Rd(reg as u8)
@@ -4514,11 +4680,18 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     WpType::F64
                 )?;
             }
-            Operator::I32TruncUF64 | Operator::I32TruncSF64 => {
+            Operator::I32TruncUF64 => {
                 Self::emit_unop(
                     assembler,
                     &mut self.value_stack,
                     |assembler, value_stack, reg| {
+                        Self::emit_f64_int_conv_check(
+                            assembler,
+                            reg,
+                            -1.0,
+                            4294967296.0,
+                        );
+
                         dynasm!(
                             assembler
                             ; movq xmm1, Rq(reg as u8)
@@ -4530,11 +4703,64 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     WpType::I32
                 )?;
             }
-            Operator::I64TruncUF64 | Operator::I64TruncSF64 => {
+            Operator::I32TruncSF64 => {
                 Self::emit_unop(
                     assembler,
                     &mut self.value_stack,
                     |assembler, value_stack, reg| {
+                        Self::emit_f64_int_conv_check(
+                            assembler,
+                            reg,
+                            -2147483649.0,
+                            2147483648.0,
+                        );
+
+                        dynasm!(
+                            assembler
+                            ; movq xmm1, Rq(reg as u8)
+                            ; roundsd xmm1, xmm1, 3
+                            ; cvtsd2si Rd(reg as u8), xmm1
+                        );
+                    },
+                    WpType::F64,
+                    WpType::I32
+                )?;
+            }
+            Operator::I64TruncUF64 => {
+                Self::emit_unop(
+                    assembler,
+                    &mut self.value_stack,
+                    |assembler, value_stack, reg| {
+                        Self::emit_f64_int_conv_check(
+                            assembler,
+                            reg,
+                            -1.0,
+                            18446744073709551616.0,
+                        );
+
+                        dynasm!(
+                            assembler
+                            ; movq xmm1, Rq(reg as u8)
+                            ; roundsd xmm1, xmm1, 3
+                            ; cvtsd2si Rq(reg as u8), xmm1
+                        );
+                    },
+                    WpType::F64,
+                    WpType::I64
+                )?;
+            }
+            Operator::I64TruncSF64 => {
+                Self::emit_unop(
+                    assembler,
+                    &mut self.value_stack,
+                    |assembler, value_stack, reg| {
+                        Self::emit_f64_int_conv_check(
+                            assembler,
+                            reg,
+                            -9223372036854777856.0,
+                            9223372036854775808.0,
+                        );
+
                         dynasm!(
                             assembler
                             ; movq xmm1, Rq(reg as u8)
@@ -4553,7 +4779,8 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     LocalOrImport::Local(local_mem_index) => {
                         let mem_desc = &module_info.memories[local_mem_index];
                         match mem_desc.memory_type() {
-                            MemoryType::Dynamic => self.native_trampolines.memory_size_dynamic_local,
+                            //MemoryType::Dynamic => self.native_trampolines.memory_size_dynamic_local,
+                            MemoryType::Dynamic => unimplemented!(),
                             MemoryType::Static => self.native_trampolines.memory_size_static_local,
                             MemoryType::SharedStatic => self.native_trampolines.memory_size_shared_local,
                         }
@@ -4561,7 +4788,8 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     LocalOrImport::Import(import_mem_index) => {
                         let mem_desc = &module_info.imported_memories[import_mem_index].1;
                         match mem_desc.memory_type() {
-                            MemoryType::Dynamic => self.native_trampolines.memory_size_dynamic_import,
+                            //MemoryType::Dynamic => self.native_trampolines.memory_size_dynamic_import,
+                            MemoryType::Dynamic => unimplemented!(),
                             MemoryType::Static => self.native_trampolines.memory_size_static_import,
                             MemoryType::SharedStatic => self.native_trampolines.memory_size_shared_import,
                         }
@@ -4581,7 +4809,8 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     LocalOrImport::Local(local_mem_index) => {
                         let mem_desc = &module_info.memories[local_mem_index];
                         match mem_desc.memory_type() {
-                            MemoryType::Dynamic => self.native_trampolines.memory_grow_dynamic_local,
+                            //MemoryType::Dynamic => self.native_trampolines.memory_grow_dynamic_local,
+                            MemoryType::Dynamic => unimplemented!(),
                             MemoryType::Static => self.native_trampolines.memory_grow_static_local,
                             MemoryType::SharedStatic => self.native_trampolines.memory_grow_shared_local,
                         }
@@ -4589,7 +4818,8 @@ impl FunctionCodeGenerator for X64FunctionCode {
                     LocalOrImport::Import(import_mem_index) => {
                         let mem_desc = &module_info.imported_memories[import_mem_index].1;
                         match mem_desc.memory_type() {
-                            MemoryType::Dynamic => self.native_trampolines.memory_grow_dynamic_import,
+                            //MemoryType::Dynamic => self.native_trampolines.memory_grow_dynamic_import,
+                            MemoryType::Dynamic => unimplemented!(),
                             MemoryType::Static => self.native_trampolines.memory_grow_static_import,
                             MemoryType::SharedStatic => self.native_trampolines.memory_grow_shared_import,
                         }
@@ -4725,13 +4955,20 @@ unsafe extern "C" fn call_indirect(
         CallIndirectLocalOrImport::Import => &*(*(*vmctx).imported_tables),
     } ;
     if elem_index >= table.count as usize {
-        panic!("element index out of bounds");
+        eprintln!("element index out of bounds");
+        unsafe { protect_unix::trigger_trap(); }
     }
     let anyfunc = &*(table.base as *mut vm::Anyfunc).offset(elem_index as isize);
     let ctx: &X64ExecutionContext =
         &*CURRENT_EXECUTION_CONTEXT.with(|x| *x.borrow().last().unwrap());
 
-    let func_index = anyfunc.func_index.unwrap();
+    let func_index = match anyfunc.func_index {
+        Some(x) => x,
+        None => {
+            eprintln!("empty table entry");
+            unsafe { protect_unix::trigger_trap(); }
+        }
+    };
 
     /*println!(
         "SIG INDEX = {}, FUNC INDEX = {:?}, ELEM INDEX = {}",
@@ -4741,7 +4978,8 @@ unsafe extern "C" fn call_indirect(
     if ctx.signatures[SigIndex::new(sig_index)]
         != ctx.signatures[ctx.function_signatures[func_index]]
     {
-        panic!("signature mismatch");
+        eprintln!("signature mismatch");
+        unsafe { protect_unix::trigger_trap(); }
     }
 
     let func = ctx.function_pointers[func_index.index() as usize].0;

lib/dynasm-backend/src/lib.rs

@@ -1,5 +1,11 @@
 #![feature(proc_macro_hygiene)]
 
+#[cfg(not(any(
+    all(target_os = "macos", target_arch = "x86_64"),
+    all(target_os = "linux", target_arch = "x86_64"),
+)))]
+compile_error!("This crate doesn't yet support compiling on operating systems other than linux and macos and architectures other than x86_64");
+
 #[macro_use]
 extern crate dynasmrt;
 
@@ -15,6 +21,7 @@ mod codegen;
 mod codegen_x64;
 mod parse;
 mod stack;
+mod protect_unix;
 
 use crate::codegen::{CodegenError, ModuleCodeGenerator};
 use crate::parse::LoadError;

lib/dynasm-backend/src/parse.rs

@@ -18,6 +18,7 @@ use wasmparser::{
     BinaryReaderError, CodeSectionReader, Data, DataKind, Element, ElementKind, Export,
     ExternalKind, FuncType, Import, ImportSectionEntryType, InitExpr, ModuleReader, Operator,
     SectionCode, Type as WpType,
+    WasmDecoder,
 };
 
 #[derive(Debug)]
@@ -38,6 +39,30 @@ impl From<CodegenError> for LoadError {
     }
 }
 
+fn validate(bytes: &[u8]) -> Result<(), LoadError> {
+    let mut parser = wasmparser::ValidatingParser::new(
+        bytes,
+        Some(wasmparser::ValidatingParserConfig {
+            operator_config: wasmparser::OperatorValidatorConfig {
+                enable_threads: false,
+                enable_reference_types: false,
+                enable_simd: false,
+                enable_bulk_memory: false,
+            },
+            mutable_global_imports: false,
+        }),
+    );
+
+    loop {
+        let state = parser.read();
+        match *state {
+            wasmparser::ParserState::EndWasm => break Ok(()),
+            wasmparser::ParserState::Error(err) => Err(LoadError::Parse(err))?,
+            _ => {}
+        }
+    }
+}
+
 pub fn read_module<
     MCG: ModuleCodeGenerator<FCG, PC, FR>,
     FCG: FunctionCodeGenerator,
@@ -48,6 +73,7 @@ pub fn read_module<
     backend: Backend,
     mcg: &mut MCG,
 ) -> Result<ModuleInfo, LoadError> {
+    validate(wasm)?;
     let mut info = ModuleInfo {
         memories: Map::new(),
         globals: Map::new(),
@@ -279,6 +305,7 @@ pub fn read_module<
                     }
                     .into());
                 }
+                mcg.check_precondition(&info)?;
                 for i in 0..code_reader.get_count() {
                     let item = code_reader.read()?;
                     let mut fcg = mcg.next_function()?;

lib/dynasm-backend/src/protect_unix.rs

@@ -0,0 +1,202 @@
+//! 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 libc::{c_int, c_void, siginfo_t};
+use nix::sys::signal::{
+    sigaction, SaFlags, SigAction, SigHandler, SigSet, Signal, SIGBUS, SIGFPE, SIGILL, SIGSEGV,
+};
+use std::cell::{Cell, UnsafeCell};
+use std::ptr;
+use std::sync::Once;
+use wasmer_runtime_core::error::{RuntimeError, RuntimeResult};
+
+extern "C" fn signal_trap_handler(
+    signum: ::nix::libc::c_int,
+    siginfo: *mut siginfo_t,
+    ucontext: *mut c_void,
+) {
+    unsafe {
+        do_unwind(signum, siginfo as _, ucontext);
+    }
+}
+
+extern "C" {
+    pub fn setjmp(env: *mut c_void) -> c_int;
+    fn longjmp(env: *mut c_void, val: c_int) -> !;
+}
+
+pub unsafe fn install_sighandler() {
+    let sa = SigAction::new(
+        SigHandler::SigAction(signal_trap_handler),
+        SaFlags::SA_ONSTACK,
+        SigSet::empty(),
+    );
+    sigaction(SIGFPE, &sa).unwrap();
+    sigaction(SIGILL, &sa).unwrap();
+    sigaction(SIGSEGV, &sa).unwrap();
+    sigaction(SIGBUS, &sa).unwrap();
+}
+
+const SETJMP_BUFFER_LEN: usize = 27;
+pub static SIGHANDLER_INIT: Once = Once::new();
+
+thread_local! {
+    pub static SETJMP_BUFFER: UnsafeCell<[c_int; SETJMP_BUFFER_LEN]> = UnsafeCell::new([0; SETJMP_BUFFER_LEN]);
+    pub static CAUGHT_ADDRESSES: Cell<(*const c_void, *const c_void)> = Cell::new((ptr::null(), ptr::null()));
+    pub static CURRENT_EXECUTABLE_BUFFER: Cell<*const c_void> = Cell::new(ptr::null());
+}
+
+pub unsafe fn trigger_trap() -> ! {
+    let jmp_buf = SETJMP_BUFFER.with(|buf| buf.get());
+
+    longjmp(jmp_buf as *mut c_void, 0)
+}
+
+pub fn call_protected<T>(f: impl FnOnce() -> T) -> RuntimeResult<T> {
+    unsafe {
+        let jmp_buf = SETJMP_BUFFER.with(|buf| buf.get());
+        let prev_jmp_buf = *jmp_buf;
+
+        SIGHANDLER_INIT.call_once(|| {
+            install_sighandler();
+        });
+
+        let signum = setjmp(jmp_buf as *mut _);
+        if signum != 0 {
+            *jmp_buf = prev_jmp_buf;
+
+            let (faulting_addr, inst_ptr) = CAUGHT_ADDRESSES.with(|cell| cell.get());
+
+            let signal = match Signal::from_c_int(signum) {
+                Ok(SIGFPE) => "floating-point exception",
+                Ok(SIGILL) => "illegal instruction",
+                Ok(SIGSEGV) => "segmentation violation",
+                Ok(SIGBUS) => "bus error",
+                Err(_) => "error while getting the Signal",
+                _ => "unkown trapped signal",
+            };
+            // When the trap-handler is fully implemented, this will return more information.
+            Err(RuntimeError::Trap {
+                msg: format!("unknown trap at {:p} - {}", faulting_addr, signal).into(),
+            }
+            .into())
+        } else {
+            let ret = f(); // TODO: Switch stack?
+            *jmp_buf = prev_jmp_buf;
+            Ok(ret)
+        }
+    }
+}
+
+/// Unwinds to last protected_call.
+pub unsafe fn do_unwind(signum: i32, siginfo: *const c_void, ucontext: *const c_void) -> ! {
+    // Since do_unwind is only expected to get called from WebAssembly code which doesn't hold any host resources (locks etc.)
+    // itself, accessing TLS here is safe. In case any other code calls this, it often indicates a memory safety bug and you should
+    // temporarily disable the signal handlers to debug it.
+
+    let jmp_buf = SETJMP_BUFFER.with(|buf| buf.get());
+    if *jmp_buf == [0; SETJMP_BUFFER_LEN] {
+        ::std::process::abort();
+    }
+
+    CAUGHT_ADDRESSES.with(|cell| cell.set(get_faulting_addr_and_ip(siginfo, ucontext)));
+
+    longjmp(jmp_buf as *mut ::nix::libc::c_void, signum)
+}
+
+#[cfg(all(target_os = "linux", target_arch = "x86_64"))]
+unsafe fn get_faulting_addr_and_ip(
+    siginfo: *const c_void,
+    ucontext: *const c_void,
+) -> (*const c_void, *const c_void) {
+    use libc::{ucontext_t, RIP};
+
+    #[allow(dead_code)]
+    #[repr(C)]
+    struct siginfo_t {
+        si_signo: i32,
+        si_errno: i32,
+        si_code: i32,
+        si_addr: u64,
+        // ...
+    }
+
+    let siginfo = siginfo as *const siginfo_t;
+    let si_addr = (*siginfo).si_addr;
+
+    let ucontext = ucontext as *const ucontext_t;
+    let rip = (*ucontext).uc_mcontext.gregs[RIP as usize];
+
+    (si_addr as _, rip as _)
+}
+
+#[cfg(all(target_os = "macos", target_arch = "x86_64"))]
+unsafe fn get_faulting_addr_and_ip(
+    siginfo: *const c_void,
+    ucontext: *const c_void,
+) -> (*const c_void, *const c_void) {
+    #[allow(dead_code)]
+    #[repr(C)]
+    struct ucontext_t {
+        uc_onstack: u32,
+        uc_sigmask: u32,
+        uc_stack: libc::stack_t,
+        uc_link: *const ucontext_t,
+        uc_mcsize: u64,
+        uc_mcontext: *const mcontext_t,
+    }
+    #[repr(C)]
+    struct exception_state {
+        trapno: u16,
+        cpu: u16,
+        err: u32,
+        faultvaddr: u64,
+    }
+    #[repr(C)]
+    struct regs {
+        rax: u64,
+        rbx: u64,
+        rcx: u64,
+        rdx: u64,
+        rdi: u64,
+        rsi: u64,
+        rbp: u64,
+        rsp: u64,
+        r8: u64,
+        r9: u64,
+        r10: u64,
+        r11: u64,
+        r12: u64,
+        r13: u64,
+        r14: u64,
+        r15: u64,
+        rip: u64,
+        rflags: u64,
+        cs: u64,
+        fs: u64,
+        gs: u64,
+    }
+    #[allow(dead_code)]
+    #[repr(C)]
+    struct mcontext_t {
+        es: exception_state,
+        ss: regs,
+        // ...
+    }
+
+    let siginfo = siginfo as *const siginfo_t;
+    let si_addr = (*siginfo).si_addr;
+
+    let ucontext = ucontext as *const ucontext_t;
+    let rip = (*(*ucontext).uc_mcontext).ss.rip;
+
+    (si_addr, rip as _)
+}

lib/runtime-core/src/types.rs

@@ -251,8 +251,8 @@ impl MemoryDescriptor {
     pub fn memory_type(self) -> MemoryType {
         match (self.maximum.is_some(), self.shared) {
             (true, true) => MemoryType::SharedStatic,
-            (true, false) => MemoryType::Static,
+            (true, false) | (false, false) => MemoryType::Static,
-            (false, false) => MemoryType::Dynamic,
+            //(false, false) => MemoryType::Dynamic,
             (false, true) => panic!("shared memory without a max is not allowed"),
         }
     }