Try to look up any stock on finance.google.com. WebKit will crash pretty deep in CSS code. Here is a backtrace using WebKitGTK 2.31.91: Core was generated by `/usr/libexec/webkit2gtk-4.0/WebKitWebProcess 454 95'. Program terminated with signal SIGSEGV, Segmentation fault. #0 WTF::RefCountedBase::derefBase (this=0x552076e) at DerivedSources/ForwardingHeaders/wtf/RefCounted.h:187 187 void deref() const [Current thread is 1 (Thread 0x7fd164e359c0 (LWP 2))] (gdb) bt #0 WTF::RefCountedBase::derefBase() const (this=0x552076e) at DerivedSources/ForwardingHeaders/wtf/RefCounted.h:187 #1 WTF::RefCounted<WebCore::CalculationValue, std::default_delete<WebCore::CalculationValue> >::deref() const (this=0x552076e) at DerivedSources/ForwardingHeaders/wtf/RefCounted.h:189 #2 WTF::Ref<WebCore::CalculationValue, WTF::RawPtrTraits<WebCore::CalculationValue> >::~Ref() (this=<synthetic pointer>, __in_chrg=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/Ref.h:61 #3 WebCore::CalculationValueMap::deref(unsigned int) (handle=<optimized out>, this=0x7fd16f0a6de0 <WebCore::calculationValues()::map>) at ../Source/WebCore/platform/Length.cpp:232 #4 WebCore::Length::deref() const (this=this@entry=0x7fcf7aaeb310) at ../Source/WebCore/platform/Length.cpp:266 #5 0x00007fd16da4aad0 in WebCore::Length::~Length() (this=<optimized out>, __in_chrg=<optimized out>) at ../Source/WebCore/platform/Length.h:219 #6 WebCore::TranslateTransformOperation::~TranslateTransformOperation() (this=0x7fcf7aaeb2f8, __in_chrg=<optimized out>) at ../Source/WebCore/platform/graphics/transforms/TranslateTransformOperation.h:34 #7 WebCore::TranslateTransformOperation::~TranslateTransformOperation() (this=0x7fcf7aaeb2f8, __in_chrg=<optimized out>) at ../Source/WebCore/platform/graphics/transforms/TranslateTransformOperation.h:34 #8 0x00007fd16cd170df in std::default_delete<WebCore::TransformOperation>::operator()(WebCore::TransformOperation*) const (__ptr=<optimized out>, this=<optimized out>) at /usr/include/c++/10.2.0/bits/unique_ptr.h:79 #9 WTF::RefCounted<WebCore::TransformOperation, std::default_delete<WebCore::TransformOperation> >::deref() const (this=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/RefCounted.h:190 #10 WTF::RefCounted<WebCore::TransformOperation, std::default_delete<WebCore::TransformOperation> >::deref() const (this=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/RefCounted.h:187 #11 WTF::DefaultRefDerefTraits<WebCore::TransformOperation>::derefIfNotNull(WebCore::TransformOperation*) (ptr=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/RefPtr.h:42 #12 WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >::~RefPtr() (this=0x7fd04c258480, __in_chrg=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/RefPtr.h:73 #13 WTF::VectorDestructor<true, WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> > >::destruct(WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >*, WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >*) (end=0x7fd04c258488, begin=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/Vector.h:67 #14 WTF::VectorTypeOperations<WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> > >::destruct(WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >*, WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >*) (end=0x7fd04c258488, begin=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/Vector.h:243 #15 WTF::Vector<WTF::RefPtr<WebCore::TransformOperation, WTF::RawPtrTraits<WebCore::TransformOperation>, WTF::DefaultRefDerefTraits<WebCore::TransformOperation> >, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>::~Vector() (this=0x7ffedbf24b90, __in_chrg=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/Vector.h:676 #16 WebCore::TransformOperations::~TransformOperations() (this=0x7ffedbf24b90, __in_chrg=<optimized out>) at ../Source/WebCore/platform/graphics/transforms/TransformOperations.h:34 #17 WebCore::Style::BuilderFunctions::applyValueTransform(WebCore::Style::BuilderState&, WebCore::CSSValue&) (builderState=..., value=...) at DerivedSources/WebCore/StyleBuilderGenerated.cpp:3392 #18 0x00007fd16ddabe69 in WebCore::Style::Builder::applyProperty(WebCore::CSSPropertyID, WebCore::CSSValue&, WebCore::SelectorChecker::LinkMatchMask) (this=<optimized out>, id=<optimized out>, value=..., linkMatchMask=<optimized out>) at DerivedSources/ForwardingHeaders/wtf/RawPtrTraits.h:43 #19 0x00007fd16ddad7f8 in WebCore::Style::Builder::applyCascadeProperty(WebCore::Style::PropertyCascade::Property const&)::{lambda(WebCore::SelectorChecker::LinkMatchMask)#1}::operator()(WebCore::SelectorChecker::LinkMatchMask) const (linkMatch=WebCore::SelectorChecker::MatchLink, __closure=<synthetic pointer>) at ../Source/WebCore/style/StyleBuilder.cpp:252 --Type <RET> for more, q to quit, c to continue without paging--c #20 WebCore::Style::Builder::applyCascadeProperty(WebCore::Style::PropertyCascade::Property const&) (property=..., this=0x7ffedbf24d60) at ../Source/WebCore/style/StyleBuilder.cpp:261 #21 WebCore::Style::Builder::applyPropertiesImpl<(WebCore::Style::Builder::CustomPropertyCycleTracking)1>(int, int) (lastProperty=<optimized out>, firstProperty=<optimized out>, this=<optimized out>) at ../Source/WebCore/style/StyleBuilder.cpp:175 #22 WebCore::Style::Builder::applyProperties(int, int) (this=this@entry=0x7ffedbf24d60, firstProperty=firstProperty@entry=31, lastProperty=lastProperty@entry=476) at ../Source/WebCore/style/StyleBuilder.cpp:143 #23 0x00007fd16ddada2f in WebCore::Style::Builder::applyLowPriorityProperties() (this=this@entry=0x7ffedbf24d60) at ../Source/WebCore/style/StyleBuilder.cpp:118 #24 0x00007fd16ddb76c8 in WebCore::Style::Resolver::applyMatchedProperties(WebCore::Style::Resolver::State&, WebCore::Style::MatchResult const&, WebCore::Style::Resolver::UseMatchedDeclarationsCache) (this=this@entry=0x7fcf7cc18cf0, state=..., matchResult=..., useMatchedDeclarationsCache=useMatchedDeclarationsCache@entry=WebCore::Style::Resolver::UseMatchedDeclarationsCache::Yes) at ../Source/WebCore/style/StyleResolver.cpp:554 #25 0x00007fd16ddb90a7 in WebCore::Style::Resolver::styleForElement(WebCore::Element const&, WebCore::RenderStyle const*, WebCore::RenderStyle const*, WebCore::RuleMatchingBehavior, WebCore::SelectorFilter const*) (this=this@entry=0x7fcf7cc18cf0, element=..., parentStyle=parentStyle@entry=0x7fd030456160, parentBoxStyle=<optimized out>, matchingBehavior=matchingBehavior@entry=WebCore::RuleMatchingBehavior::MatchAllRules, selectorFilter=<optimized out>) at ../Source/WebCore/style/StyleResolver.cpp:241 #26 0x00007fd16ddc5e48 in WebCore::Style::TreeResolver::styleForStyleable(WebCore::Styleable const&, WebCore::RenderStyle const&) (this=0x7ffedbf2ba00, styleable=..., inheritedStyle=...) at ../Source/WebCore/style/StyleTreeResolver.h:91 #27 0x00007fd16ddc7a4a in WebCore::Style::TreeResolver::resolveElement(WebCore::Element&) (this=0x7ffedbf2ba00, element=...) at DerivedSources/ForwardingHeaders/wtf/Vector.h:343 #28 0x00007fd16ddc84af in WebCore::Style::TreeResolver::resolveComposedTree() (this=0x7ffedbf2ba00) at ../Source/WebCore/style/StyleTreeResolver.cpp:533 #29 0x00007fd16ddc8f89 in WebCore::Style::TreeResolver::resolve() (this=this@entry=0x7ffedbf2ba00) at ../Source/WebCore/style/StyleTreeResolver.cpp:591 #30 0x00007fd16d28dbc9 in WebCore::Document::resolveStyle(WebCore::Document::ResolveStyleType) (this=0x7fd164158e20, type=<optimized out>) at ../Source/WebCore/dom/Document.cpp:2056 #31 0x00007fd16d28e340 in WebCore::Document::updateStyleIfNeeded() (this=0x7fd164158e20) at ../Source/WebCore/dom/Document.cpp:2156 #32 0x00007fd16d28e456 in WebCore::Document::updateLayout() (this=0x7fd164158e20) at ../Source/WebCore/dom/Document.cpp:2177 #33 0x00007fd16d28eb26 in WebCore::Document::updateLayoutIgnorePendingStylesheets(WebCore::Document::RunPostLayoutTasks) (this=0x7fd164158e20, runPostLayoutTasks=runPostLayoutTasks@entry=WebCore::Document::RunPostLayoutTasks::Asynchronously) at ../Source/WebCore/dom/Document.cpp:2197 #34 0x00007fd16d2ad8ac in WebCore::Element::scrollLeft() (this=0x7fd164159b80) at /usr/include/c++/10.2.0/bits/refwrap.h:337 #35 0x00007fd16c773f25 in WebCore::jsElement_scrollLeftGetter (thisObject=..., lexicalGlobalObject=...) at DerivedSources/WebCore/JSElement.cpp:2743 #36 WebCore::IDLAttribute<WebCore::JSElement>::get<WebCore::jsElement_scrollLeftGetter, (WebCore::CastedThisErrorBehavior)3> (attributeName=0x7fd16e366c4d "scrollLeft", thisValue=<optimized out>, lexicalGlobalObject=...) at ../Source/WebCore/bindings/js/JSDOMAttribute.h:67 #37 WebCore::jsElement_scrollLeft(JSC::JSGlobalObject*, JSC::EncodedJSValue, JSC::PropertyName) (lexicalGlobalObject=<optimized out>, thisValue=<optimized out>) at DerivedSources/WebCore/JSElement.cpp:2748 #38 0x00007fd16abf18d0 in JSC::PropertySlot::customGetter(JSC::JSGlobalObject*, JSC::PropertyName) const (this=<optimized out>, globalObject=globalObject@entry=0x7fd0c849a068, propertyName=..., propertyName@entry=...) at ../Source/JavaScriptCore/runtime/JSCJSValueInlines.h:219 #39 0x00007fd16a88dbbb in JSC::PropertySlot::getValue(JSC::JSGlobalObject*, JSC::PropertyName) const (propertyName=..., globalObject=0x7fd0c849a068, this=0x7ffedbf2c030) at ../Source/JavaScriptCore/runtime/PropertySlot.h:407 #40 JSC::JSValue::get(JSC::JSGlobalObject*, JSC::PropertyName, JSC::PropertySlot&) const (slot=..., propertyName=..., globalObject=0x7fd0c849a068, this=0x7ffedbf2bfe8) at ../Source/JavaScriptCore/runtime/JSCJSValueInlines.h:950 #41 JSC::LLInt::performLLIntGetByID(JSC::Instruction const*, JSC::CodeBlock*, JSC::JSGlobalObject*, JSC::JSValue, JSC::Identifier const&, JSC::GetByIdModeMetadata&) (pc=0x7fcf8408a464, codeBlock=0x7fcf7fa52400, globalObject=0x7fd0c849a068, baseValue=..., ident=..., metadata=...) at ../Source/JavaScriptCore/llint/LLIntSlowPaths.cpp:759 #42 0x00007fd16a88ec3f in JSC::LLInt::llint_slow_path_get_by_id(JSC::CallFrame*, JSC::Instruction const*) (callFrame=0x7ffedbf2c260, pc=0x7fcf8408a464) at ../Source/JavaScriptCore/llint/LLIntSlowPaths.cpp:833 #43 0x00007fd169ec32fa in llint_op_get_by_id () at /usr/lib/debug/source/sdk/webkitgtk.bst/Source/JavaScriptCore/llint/LowLevelInterpreter64.asm:97 #44 0xfffe000000000000 in () #45 0xfffe000000000002 in () #46 0x00007ffedbf2c260 in () #47 0x00007fd169ed4aa7 in llint_op_call () at /usr/lib/debug/source/sdk/webkitgtk.bst/Source/JavaScriptCore/llint/LowLevelInterpreter.asm:1093 #48 0x00007fcf7fa52520 in () #49 0x00007fd0e84f6c60 in () #50 0xfffe000000000000 in () #51 0x00007fd0e84e2a40 in () #52 0x00007fd0186f0000 in () #53 0x00007fd0e84f6920 in () #54 0x00007fd0c84ff3c8 in () #55 0x00007fd15eefc8d8 in () #56 0x00007fd0186f0000 in () #57 0x00007fd0186f0000 in () #58 0x00007fcf7fcb4c10 in () #59 0x00007fcf7fc49498 in () #60 0xfffe000000000000 in () #61 0xfffe000000000002 in () #62 0x00007ffedbf2c310 in () #63 0x00007fd169ed4aa7 in llint_op_call () at /usr/lib/debug/source/sdk/webkitgtk.bst/Source/JavaScriptCore/llint/LowLevelInterpreter.asm:1093 #64 0x00007fcf7fa52400 in () #65 0x00007fd0e84f6c40 in () #66 0x000000c400000002 in () #67 0x00007fd0e84e2a40 in () #68 0x00007fd0c84ff3c8 in () #69 0x0000000000000000 in () Full backtrace attached.
Created attachment 423489 [details] bt full
I cannot reproduce this in Safari.
<rdar://problem/75786031>
Another variant on the same issue: gdb) bt #0 std::__uniq_ptr_impl<WebCore::CalcExpressionNode, std::default_delete<WebCore::CalcExpressionNode> >::_M_ptr() const (this=0x45c057e) at /usr/include/c++/10.2.0/bits/unique_ptr.h:421 #1 std::unique_ptr<WebCore::CalcExpressionNode, std::default_delete<WebCore::CalcExpressionNode> >::get() const (this=0x45c057e) at /usr/include/c++/10.2.0/bits/unique_ptr.h:422 #2 std::unique_ptr<WebCore::CalcExpressionNode, std::default_delete<WebCore::CalcExpressionNode> >::operator*() const (this=0x45c057e) at /usr/include/c++/10.2.0/bits/unique_ptr.h:407 #3 WebCore::CalculationValue::expression() const (this=0x45c0576) at ../Source/WebCore/platform/CalculationValue.h:193 #4 WebCore::CalcExpressionBlendLength::CalcExpressionBlendLength(WebCore::Length, WebCore::Length, float) (this=0x7f57cc008780, from=..., to=..., progress=<optimized out>) at ../Source/WebCore/platform/CalculationValue.cpp:233 #5 0x00007f599627f9e7 in std::make_unique<WebCore::CalcExpressionBlendLength, WebCore::Length const&, WebCore::Length const&, double&>(WebCore::Length const&, WebCore::Length const&, double&) () at ../Source/WebCore/platform/CalculationValue.h:67 #6 WTF::makeUnique<WebCore::CalcExpressionBlendLength, WebCore::Length const&, WebCore::Length const&, double&>(WebCore::Length const&, WebCore::Length const&, double&) () at DerivedSources/ForwardingHeaders/wtf/StdLibExtras.h:507 #7 WebCore::blendMixedTypes(WebCore::Length const&, WebCore::Length const&, double) (from=..., to=..., progress=<optimized out>) at ../Source/WebCore/platform/Length.cpp:305 #8 0x00007f599627fd27 in WebCore::blend(WebCore::Length const&, WebCore::Length const&, double) (from=..., to=..., progress=progress@entry=0.38128000497817993) at ../Source/WebCore/platform/Length.cpp:318 #9 0x00007f59963b1286 in WebCore::TranslateTransformOperation::blend(WebCore::TransformOperation const*, double, bool) (this=0x7f57cc035d70, from=<optimized out>, progress=<optimized out>, blendToIdentity=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/string_fortified.h:34 #10 0x00007f5994ff55bb in Nicosia::applyTransformAnimation (listsMatch=<optimized out>, boxSize=..., progress=<optimized out>, to=..., from=...) at ../Source/WebCore/platform/graphics/transforms/TransformOperations.h:84 #11 Nicosia::Animation::applyInternal(Nicosia::Animation::ApplicationResult&, WebCore::AnimationValue const&, WebCore::AnimationValue const&, float) (this=0x7f57acaf1690, applicationResults=..., from=..., to=..., progress=<optimized out>) at ../Source/WebCore/platform/graphics/nicosia/NicosiaAnimation.cpp:314 #12 0x00007f5994ff683c in Nicosia::Animations::apply(Nicosia::Animation::ApplicationResult&, WTF::MonotonicTime) (this=this@entry=0x7f57a54d3a60, applicationResults=..., time=...) at ../Source/WebCore/platform/graphics/nicosia/NicosiaAnimation.cpp:377 #13 0x00007f5994ffa6c1 in WebCore::TextureMapperLayer::syncAnimations(WTF::MonotonicTime) (this=this@entry=0x7f57a54d3800, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:748 #14 0x00007f5994ffaccb in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=0x7f57a54d3800, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:735 #15 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #16 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #17 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #18 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #19 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #20 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #21 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #22 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) --Type <RET> for more, q to quit, c to continue without paging--c (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #23 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=<optimized out>, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #24 0x00007f5994ffad33 in WebCore::TextureMapperLayer::applyAnimationsRecursively(WTF::MonotonicTime) (this=this@entry=0x7f5985e34000, time=...) at ../Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:741 #25 0x00007f5994c49773 in WebKit::CoordinatedGraphicsScene::paintToCurrentGLContext(WebCore::TransformationMatrix const&, WebCore::FloatRect const&, unsigned int) (this=this@entry=0x7f588c6fd000, matrix=..., clipRect=..., PaintFlags=PaintFlags@entry=1) at ../Source/WebKit/Shared/CoordinatedGraphics/CoordinatedGraphicsScene.cpp:71 #26 0x00007f5994c49d57 in WebKit::ThreadedCompositor::renderLayerTree() (this=0x7f58ac205b80) at DerivedSources/ForwardingHeaders/WebCore/FloatRect.h:71 #27 WebKit::ThreadedCompositor::renderLayerTree() (this=0x7f58ac205b80) at ../Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.cpp:179 #28 0x00007f599386b605 in operator() (__closure=0x0, userData=0x7f58ac2185a8) at ../Source/WTF/wtf/glib/RunLoopGLib.cpp:176 #29 _FUN(gpointer) () at ../Source/WTF/wtf/glib/RunLoopGLib.cpp:181 #30 0x00007f599386b883 in operator() (__closure=0x0, userData=0x7f58ac2185a8, callback=0x7f599386b5a0 <_FUN(gpointer)>, source=0x559e46f00dc0) at ../Source/WTF/wtf/glib/RunLoopGLib.cpp:53 #31 _FUN(GSource*, GSourceFunc, gpointer) () at ../Source/WTF/wtf/glib/RunLoopGLib.cpp:56 #32 0x00007f5993c7c1af in g_main_dispatch (context=0x7f57b8000b60) at ../glib/gmain.c:3337 #33 g_main_context_dispatch (context=0x7f57b8000b60) at ../glib/gmain.c:4055 #34 0x00007f5993c7c558 in g_main_context_iterate (context=0x7f57b8000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4131 #35 0x00007f5993c7c873 in g_main_loop_run (loop=loop@entry=0x7f57b8001b10) at ../glib/gmain.c:4329 #36 0x00007f599386b9e0 in WTF::RunLoop::run() () at ../Source/WTF/wtf/glib/RunLoopGLib.cpp:108 #37 0x00007f599381bf3d in WTF::Function<void ()>::operator()() const (this=<synthetic pointer>) at ../Source/WTF/wtf/Function.h:80 #38 WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) (newThreadContext=0x7f58ac22fee8) at ../Source/WTF/wtf/Threading.cpp:181 #39 0x00007f599386dc4d in WTF::wtfThreadEntryPoint(void*) (context=<optimized out>) at ../Source/WTF/wtf/posix/ThreadingPOSIX.cpp:241 #40 0x00007f59904024d2 in start_thread (arg=<optimized out>) at pthread_create.c:477 #41 0x00007f59941b4323 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95