Process: WebProcess [18394] Path: /Applications/WebKit.app/Contents/Frameworks/10.6/WebKit2.framework/WebProcess.app/Contents/MacOS/WebProcess Identifier: com.apple.WebProcess Version: 537+ (537.1+) Code Type: X86-64 (Native) Parent Process: Safari [18389] Date/Time: 2012-06-28 14:31:45.456 -0700 OS Version: Mac OS X 10.6.8 (10K549) Report Version: 6 Interval Since Last Report: 110230 sec Crashes Since Last Report: 7 Per-App Interval Since Last Report: 191672 sec Per-App Crashes Since Last Report: 7 Anonymous UUID: ACBC7F66-38E8-4DED-AF6F-3F742A121163 Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x0000003922d26fe4 Crashed Thread: 0 Dispatch queue: com.apple.main-thread Thread 0 Crashed: Dispatch queue: com.apple.main-thread 0 com.apple.JavaScriptCore 0x000000010123d5f5 JSC::DFG::CFGSimplificationPhase::mergeBlocks(unsigned int, unsigned int, unsigned int) + 1365 1 com.apple.JavaScriptCore 0x000000010123c9e5 JSC::DFG::CFGSimplificationPhase::run() + 389 2 com.apple.JavaScriptCore 0x000000010123c850 JSC::DFG::performCFGSimplification(JSC::DFG::Graph&) + 32 3 com.apple.JavaScriptCore 0x000000010105fb75 JSC::DFG::compile(JSC::DFG::CompileMode, JSC::ExecState*, JSC::CodeBlock*, JSC::JITCode&, JSC::MacroAssemblerCodePtr*) + 853 4 com.apple.JavaScriptCore 0x000000010105f81a JSC::DFG::tryCompileFunction(JSC::ExecState*, JSC::CodeBlock*, JSC::JITCode&, JSC::MacroAssemblerCodePtr&) + 26 5 com.apple.JavaScriptCore 0x00000001010c5e94 JSC::jitCompileFunctionIfAppropriate(JSC::ExecState*, WTF::OwnPtr<JSC::FunctionCodeBlock>&, JSC::JITCode&, JSC::MacroAssemblerCodePtr&, JSC::SharedSymbolTable*&, JSC::JITCode::JITType, JSC::JITCompilationEffort) + 308 6 com.apple.JavaScriptCore 0x00000001010c4916 JSC::FunctionExecutable::compileForCallInternal(JSC::ExecState*, JSC::ScopeChainNode*, JSC::JITCode::JITType) + 294 7 com.apple.JavaScriptCore 0x00000001011126b2 cti_optimize + 258 8 ??? 0x000037947cfa2edf 0 + 61110891458271 9 com.apple.JavaScriptCore 0x00000001010d0826 JSC::Interpreter::execute(JSC::EvalExecutable*, JSC::ExecState*, JSC::JSValue, JSC::ScopeChainNode*, int) + 1190 10 com.apple.JavaScriptCore 0x000000010113842f JSC::globalFuncEval(JSC::ExecState*) + 1231 11 ??? 0x000037947ca01265 0 + 61110885552741 12 com.apple.JavaScriptCore 0x00000001010d3701 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 913 13 com.apple.JavaScriptCore 0x0000000101028d44 JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 52 14 com.apple.JavaScriptCore 0x0000000101122600 JSC::boundFunctionCall(JSC::ExecState*) + 400 15 ??? 0x000037947ca01265 0 + 61110885552741 16 com.apple.JavaScriptCore 0x00000001010d3701 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 913 17 com.apple.JavaScriptCore 0x0000000101028d44 JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 52 18 com.apple.JavaScriptCore 0x0000000101122600 JSC::boundFunctionCall(JSC::ExecState*) + 400 19 ??? 0x000037947ca01265 0 + 61110885552741 20 com.apple.JavaScriptCore 0x00000001010d3701 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 913 21 com.apple.JavaScriptCore 0x0000000101028d44 JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 52 22 com.apple.JavaScriptCore 0x0000000101122600 JSC::boundFunctionCall(JSC::ExecState*) + 400 23 com.apple.JavaScriptCore 0x00000001010d3821 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 1201 24 com.apple.JavaScriptCore 0x0000000101028d44 JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 52 25 com.apple.WebCore 0x0000000101988ad5 WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext*, WebCore::Event*) + 901 26 com.apple.WebCore 0x0000000101690397 WebCore::EventTarget::fireEventListeners(WebCore::Event*, WebCore::EventTargetData*, WTF::Vector<WebCore::RegisteredEventListener, 1ul>&) + 215 27 com.apple.WebCore 0x000000010169022d WebCore::EventTarget::dispatchEvent(WTF::PassRefPtr<WebCore::Event>) + 141 28 com.apple.WebCore 0x0000000101fd1526 WebCore::XMLHttpRequestProgressEventThrottle::dispatchEvent(WTF::PassRefPtr<WebCore::Event>) + 342 29 com.apple.WebCore 0x0000000101fd1598 WebCore::XMLHttpRequestProgressEventThrottle::dispatchReadyStateChangeEvent(WTF::PassRefPtr<WebCore::Event>, WebCore::ProgressEventAction) + 56 30 com.apple.WebCore 0x0000000101fcc7d2 WebCore::XMLHttpRequest::callReadyStateChangeListener() + 354 31 com.apple.WebCore 0x0000000101fd0306 WebCore::XMLHttpRequest::didFinishLoading(unsigned long, double) + 358 32 com.apple.WebCore 0x0000000101552547 WebCore::DocumentThreadableLoader::notifyFinished(WebCore::CachedResource*) + 423 33 com.apple.WebCore 0x000000010142788d WebCore::CachedResource::checkNotify() + 93 34 com.apple.WebCore 0x00000001014267e0 WebCore::CachedRawResource::data(WTF::PassRefPtr<WebCore::SharedBuffer>, bool) + 448 35 com.apple.WebCore 0x0000000101e545df WebCore::SubresourceLoader::didFinishLoading(double) + 143 36 com.apple.Foundation 0x00007fff83d3786c _NSURLConnectionDidFinishLoading + 113 37 com.apple.CFNetwork 0x00007fff8117a0ea URLConnectionClient::_clientDidFinishLoading(URLConnectionClient::ClientConnectionEventQueue*) + 174 38 com.apple.CFNetwork 0x00007fff811e022c URLConnectionClient::ClientConnectionEventQueue::processAllEventsAndConsumePayload(XConnectionEventInfo<XClientEvent, XClientEventParams>*, long) + 254 39 com.apple.CFNetwork 0x00007fff811e0498 URLConnectionClient::ClientConnectionEventQueue::processAllEventsAndConsumePayload(XConnectionEventInfo<XClientEvent, XClientEventParams>*, long) + 874 40 com.apple.CFNetwork 0x00007fff811666d7 URLConnectionClient::processEvents() + 121 41 com.apple.CFNetwork 0x00007fff811664b2 MultiplexerSource::perform() + 160 42 com.apple.CoreFoundation 0x00007fff86c6327d __CFRunLoopDoSources0 + 1021 43 com.apple.CoreFoundation 0x00007fff86c615c9 __CFRunLoopRun + 873 44 com.apple.CoreFoundation 0x00007fff86c60d8f CFRunLoopRunSpecific + 575 45 com.apple.HIToolbox 0x00007fff81b7e7ee RunCurrentEventLoopInMode + 333 46 com.apple.HIToolbox 0x00007fff81b7e5f3 ReceiveNextEventCommon + 310 47 com.apple.HIToolbox 0x00007fff81b7e4ac BlockUntilNextEventMatchingListInMode + 59 48 com.apple.AppKit 0x00007fff89c86eb2 _DPSNextEvent + 708 49 com.apple.AppKit 0x00007fff89c86801 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 155 50 com.apple.AppKit 0x00007fff89c4c68f -[NSApplication run] + 395 51 com.apple.WebCore 0x0000000101d8fd23 WebCore::RunLoop::run() + 67 52 com.apple.WebKit2 0x00000001002e1d4a WebKit::WebProcessMain(WebKit::CommandLine const&) + 700 53 com.apple.WebKit2 0x000000010029779b WebKitMain + 285 54 com.apple.WebProcess 0x0000000100000e5e main + 214 55 com.apple.WebProcess 0x0000000100000d80 start + 52
Nice catch, and thanks for the bug report. It appears that the control flow graph simplification phase (DFGCFGSimplificationPhase) was forgetting to check if a variable was captured when doing variable relinking. It was seeing IR like: a: GetLocal(stuff, r15*) b: Phantom(@a) Ordinarily, if merging two basic blocks with the second block having IR like the above, it should find the last access to local r15 and relink the Phantom to that access. But this is not true for captured variables, where the same basic block may have had a store to r15, and the previous block(s) had no mention of r15. This was true in this case, so its attempt to find an access to r15 in the previous block failed. Simple fix on the way. I will try to write a reduced test case as well.
Created attachment 150300 [details] the patch
Landed in http://trac.webkit.org/changeset/121629