Created attachment 259756 [details] test case STEPS TO REPRODUCE: 1. Open the attached test case. 2. Open Web Inspector 3. Open Inspector^2 (Right-click and "Inspecto Element" in the Web Inspector, if the option doesn't exist follow steps here: http://trac.webkit.org/wiki/WebInspectorDebugging) 4. In Debugger tab, enable "Break on [All] Exceptions". 5. Set a breakpoint in Inspector^1 at the line with `console.assert(...)`. 6. Reload the inspected page. EXPECTED: * Should pause at console.assert line but not at the breakpoint, because of Step (4). ACTUAL: * Crashes with this callstack (100% reproducible on my machine) -- Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x00000000bbadbeef VM Regions Near 0xbbadbeef: --> __TEXT 0000000106d1c000-0000000106d1e000 [ 8K] r-x/rwx SM=COW /Users/USER/*/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.Development.xpc/Contents/MacOS/com.apple.WebKit.WebContent.Development Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.JavaScriptCore 0x000000010d326fbe WTFCrash + 62 1 com.apple.JavaScriptCore 0x000000010cd2b348 JSC::CodeBlock::setOptimizationThresholdBasedOnCompilationResult(JSC::CompilationResult) + 776 2 com.apple.JavaScriptCore 0x000000010d09af9c JSC::JITToDFGDeferredCompilationCallback::compilationDidComplete(JSC::CodeBlock*, JSC::CompilationResult) + 140 3 com.apple.JavaScriptCore 0x000000010cf31691 JSC::DFG::Worklist::completeAllReadyPlansForVM(JSC::VM&, JSC::DFG::CompilationKey) + 257 4 com.apple.JavaScriptCore 0x000000010cf318ce JSC::DFG::Worklist::completeAllPlansForVM(JSC::VM&) + 62 5 com.apple.JavaScriptCore 0x000000010cf32ca8 JSC::DFG::completeAllPlansForVM(JSC::VM&) + 56 6 com.apple.JavaScriptCore 0x000000010cd6852c JSC::Debugger::exception(JSC::ExecState*, JSC::JSValue, bool) + 108 7 com.apple.JavaScriptCore 0x000000010d043475 JSC::Interpreter::unwind(void*&, JSC::ExecState*&, JSC::Exception*) + 325 8 com.apple.JavaScriptCore 0x000000010d06149a JSC::genericUnwind(JSC::VM*, JSC::ExecState*) + 90 9 com.apple.JavaScriptCore 0x000000010d19c41d llint_slow_path_handle_exception + 45 10 com.apple.JavaScriptCore 0x000000010d1a420a llint_entry + 15423 11 com.apple.JavaScriptCore 0x000000010d1a5efd llint_entry + 22834 12 com.apple.JavaScriptCore 0x000000010d1a03bb vmEntryToJavaScript + 326 13 com.apple.JavaScriptCore 0x000000010d05fbe9 JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) + 169 14 com.apple.JavaScriptCore 0x000000010d0464da JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 474 15 com.apple.JavaScriptCore 0x000000010cd12a0e JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 62 16 com.apple.JavaScriptCore 0x000000010d2d31ce JSC::JSJobMicrotask::run(JSC::ExecState*) + 734 17 com.apple.WebCore 0x000000010de24add WebCore::JSGlobalObjectCallback::call() + 189 (JSMainThreadExecState.h:93) 18 com.apple.WebCore 0x000000010d9eaf31 std::__1::__function::__func<WebCore::Document::postTask(WebCore::ScriptExecutionContext::Task)::$_0, std::__1::allocator<WebCore::Document::postTask(WebCore::ScriptExecutionContext::Task)::$_0>, void ()>::operator()() + 113 (memory:2624) 19 com.apple.JavaScriptCore 0x000000010d33f97d WTF::dispatchFunctionsFromMainThread() + 525 20 com.apple.Foundation 0x00007fff8941cdd0 __NSThreadPerformPerform + 293 21 com.apple.CoreFoundation 0x00007fff8ed5da01 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 22 com.apple.CoreFoundation 0x00007fff8ed4fb8d __CFRunLoopDoSources0 + 269 23 com.apple.CoreFoundation 0x00007fff8ed4f1bf __CFRunLoopRun + 927 24 com.apple.CoreFoundation 0x00007fff8ed4ebd8 CFRunLoopRunSpecific + 296 25 com.apple.HIToolbox 0x00007fff890b656f RunCurrentEventLoopInMode + 235 26 com.apple.HIToolbox 0x00007fff890b62ea ReceiveNextEventCommon + 431 27 com.apple.HIToolbox 0x00007fff890b612b _BlockUntilNextEventMatchingListInModeWithFilter + 71 28 com.apple.AppKit 0x00007fff852938ab _DPSNextEvent + 978 29 com.apple.AppKit 0x00007fff85292e58 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 346 30 com.apple.AppKit 0x00007fff85288af3 -[NSApplication run] + 594 31 com.apple.AppKit 0x00007fff85205244 NSApplicationMain + 1832 32 libxpc.dylib 0x00007fff9295f928 _xpc_objc_main + 793 33 libxpc.dylib 0x00007fff92961030 xpc_main + 490 34 com.apple.WebKit.WebContent.Development 0x0000000106d1d675 main + 21 (XPCServiceMain.Development.mm:90) 35 libdyld.dylib 0x00007fff8cff55c9 start + 1
I can't seem to reproduce this using Spade-188767-74819.
Possibly useful message that got dumped to console: toLength#CIvpti:[0x121ad8250->0x113499800, BaselineFunctionCall, 66 (StrictMode) (FTLFail)]: we have result = CompilationSuccessful but we are our own replacement.
I was able to reproduce this with a build from Sunday, prior to ggaren's two patches being rolled back in. So this might be unrelated to those patches after all. Another one: readToken#AvwLUZ:[0x12822a250->0x119dc5f00, BaselineFunctionCall, 388 (StrictMode) (FTLFail)]: we have result = CompilationSuccessful but we are our own replacement.
Created attachment 260288 [details] better test case
Simpler steps to reproduce: STEPS TO REPRODUCE: 1. Open the attached test case. 2. Open Web Inspector 3. In Debugger tab, enable "Break on [All] Exceptions" (at the top of the left sidebar). 4. Set a breakpoint at the line with `console.assert(...)`. 5. Reload the inspected page. EXPECTED: * Should pause at at the breakpoint. Breakpoint should be hit before evaluating console.assert, which also pauses the debugger. ACTUAL: * Crashes with this callstack in Debugger::pause underneath evaluating console.assert. --
I have bisected the regression to this commit: http://trac.webkit.org/changeset/188714 Please advise whether this can be fixed quickly or it should be rolled out for further analysis.
I still can't seem to reproduce this crash, using a debug or release build. Is there anything special to how you toggle breakpoints or reload the page? I can't promise a quick fix if I can't reproduce the crash -- but I also don't think the original patch will roll out cleanly :(.
After a full rebuild on ToT, no longer able to reproduce. Closing for now.
Saam was able to reproduce this last night on TOT.
<rdar://problem/22527158>
This no longer crashes for me