wasi: accept wasm i32 pointers with high bit set

src/node_wasi.cc

@@ -36,6 +36,7 @@ using v8::FastApiCallbackOptions;
 using v8::FunctionCallbackInfo;
 using v8::FunctionTemplate;
 using v8::HandleScope;
+using v8::Int32;
 using v8::Integer;
 using v8::Isolate;
 using v8::Local;
@@ -296,13 +297,17 @@ static bool CheckType(Local<Value> v);
 template <typename VT>
 static VT ConvertType(Local<Value> V);
 
+// Wasm i32 values with the high bit set arrive as negative Int32 numbers.
 template <>
 bool CheckType<uint32_t>(Local<Value> value) {
-  return value->IsUint32();
+  return value->IsUint32() || value->IsInt32();
 }
 
 template <>
 uint32_t ConvertType(Local<Value> value) {
+  if (value->IsInt32()) {
+    return static_cast<uint32_t>(value.As<Int32>()->Value());
+  }
   return value.As<Uint32>()->Value();
 }
 

test/fixtures/wasi-high-bit-ptr.wat

@@ -0,0 +1,22 @@
+;; Build: wasm-tools parse wasi-high-bit-ptr.wat -o wasi-high-bit-ptr.wasm
+(module
+  (import "wasi_snapshot_preview1" "clock_time_get"
+    (func $clock_time_get (param i32 i64 i32) (result i32)))
+  (import "wasi_snapshot_preview1" "args_sizes_get"
+    (func $args_sizes_get (param i32 i32) (result i32)))
+  (memory (export "memory") 1)
+  (func (export "_start"))
+  (func (export "clock_time_get_high_ptr") (result i32)
+    i32.const 0
+    i64.const 1
+    i32.const 0x80000000
+    call $clock_time_get)
+  (func (export "clock_time_get_low_ptr") (result i32)
+    i32.const 0
+    i64.const 1
+    i32.const 8
+    call $clock_time_get)
+  (func (export "args_sizes_get_high_ptr") (result i32)
+    i32.const 0x80000000
+    i32.const 0xfffffff0
+    call $args_sizes_get))

test/wasi/test-wasi-high-bit-ptr.js

@@ -0,0 +1,24 @@
+'use strict';
+// Wasm i32 arguments with the high bit set arrive in JS as negative Int32
+// numbers. WASI functions must reinterpret them as uint32 pointers rather
+// than rejecting them with EINVAL.
+const common = require('../common');
+const assert = require('assert');
+const fixtures = require('../common/fixtures');
+const { WASI } = require('wasi');
+
+const UVWASI_EOVERFLOW = 61;
+
+(async () => {
+  const wasi = new WASI({ version: 'preview1', returnOnExit: true });
+  const importObject = { wasi_snapshot_preview1: wasi.wasiImport };
+  const { instance } = await WebAssembly.instantiate(
+    fixtures.readSync('wasi-high-bit-ptr.wasm'), importObject);
+  wasi.start(instance);
+
+  assert.strictEqual(instance.exports.clock_time_get_low_ptr(), 0);
+  assert.strictEqual(instance.exports.clock_time_get_high_ptr(),
+                     UVWASI_EOVERFLOW);
+  assert.strictEqual(instance.exports.args_sizes_get_high_ptr(),
+                     UVWASI_EOVERFLOW);
+})().then(common.mustCall());