src: handle wasm out of bound in osx will raise SIGBUS correctly

src/node.cc

@@ -365,10 +365,19 @@ static LONG TrapWebAssemblyOrContinue(EXCEPTION_POINTERS* exception) {
 }
 #else
 static std::atomic<sigaction_cb> previous_sigsegv_action;
+// TODO(align behavior between macos and other in next major version)
+#if defined(__APPLE__)
+static std::atomic<sigaction_cb> previous_sigbus_action;
+#endif  // __APPLE__
 
 void TrapWebAssemblyOrContinue(int signo, siginfo_t* info, void* ucontext) {
   if (!v8::TryHandleWebAssemblyTrapPosix(signo, info, ucontext)) {
+#if defined(__APPLE__)
+    sigaction_cb prev = signo == SIGBUS ? previous_sigbus_action.load()
+                                        : previous_sigsegv_action.load();
+#else
     sigaction_cb prev = previous_sigsegv_action.load();
+#endif  // __APPLE__
     if (prev != nullptr) {
       prev(signo, info, ucontext);
     } else {
@@ -398,6 +407,15 @@ void RegisterSignalHandler(int signal,
     previous_sigsegv_action.store(handler);
     return;
   }
+// TODO(align behavior between macos and other in next major version)
+#if defined(__APPLE__)
+  if (signal == SIGBUS) {
+    CHECK(previous_sigbus_action.is_lock_free());
+    CHECK(!reset_handler);
+    previous_sigbus_action.store(handler);
+    return;
+  }
+#endif  // __APPLE__
 #endif  // NODE_USE_V8_WASM_TRAP_HANDLER
   struct sigaction sa;
   memset(&sa, 0, sizeof(sa));
@@ -554,14 +572,18 @@ static void PlatformInit(ProcessInitializationFlags::Flags flags) {
 #else
     // Tell V8 to disable emitting WebAssembly
     // memory bounds checks. This means that we have
-    // to catch the SIGSEGV in TrapWebAssemblyOrContinue
+    // to catch the SIGSEGV/SIGBUS in TrapWebAssemblyOrContinue
     // and pass the signal context to V8.
     {
       struct sigaction sa;
       memset(&sa, 0, sizeof(sa));
       sa.sa_sigaction = TrapWebAssemblyOrContinue;
       sa.sa_flags = SA_SIGINFO;
       CHECK_EQ(sigaction(SIGSEGV, &sa, nullptr), 0);
+// TODO(align behavior between macos and other in next major version)
+#if defined(__APPLE__)
+      CHECK_EQ(sigaction(SIGBUS, &sa, nullptr), 0);
+#endif
     }
 #endif  // defined(_WIN32)
     V8::EnableWebAssemblyTrapHandler(false);

test/fixtures/out-of-bound.wat

@@ -0,0 +1,16 @@
+(module
+ (type $none_=>_none (func))
+ (memory $0 1)
+ (export "_start" (func $_start))
+ (func $_start
+  memory.size
+  i32.const 64
+  i32.mul
+  i32.const 1024
+  i32.mul
+  i32.const 3
+  i32.sub
+  i32.load
+  drop
+ )
+)

test/parallel/test-wasm-memory-out-of-bound.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const fixtures = require('../common/fixtures');
+
+const buffer = fixtures.readSync('out-of-bound.wasm');
+WebAssembly.instantiate(buffer, {}).then(common.mustCall((results) => {
+  assert.throws(() => {
+    results.instance.exports._start();
+  }, WebAssembly.RuntimeError('memory access out of bounds'));
+}));