Crash Reports for Crash Reports for js::MaybeGC(JSContext*) - https://crash-stats.mozilla.com/report/list?signature=js::MaybeGC%28JSContext*%29 also affects beta 9 builds. no steps to reproduce so far - windows only so far Crashing Thread Frame Module Signature [Expand] Source 0 mozjs.dll js::MaybeGC js/src/jsgc.cpp:1842 1 mozjs.dll JS_MaybeGC js/src/jsapi.cpp:2559 2 xul.dll nsJSContext::ScriptEvaluated dom/base/nsJSEnvironment.cpp:3542 3 xul.dll nsJSContext::ScriptExecuted dom/base/nsJSEnvironment.cpp:3608 4 xul.dll nsXPCWrappedJSClass::CallMethod js/src/xpconnect/src/xpcwrappedjsclass.cpp:1939 5 xul.dll nsXPCWrappedJS::CallMethod js/src/xpconnect/src/xpcwrappedjs.cpp:588 6 xul.dll PrepareAndDispatch xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:114 7 xul.dll SharedStub xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:141 8 xul.dll NS_SecurityCompareURIs obj-firefox/dist/include/nsNetUtil.h:1691 9 mozcrt19.dll arena_dalloc obj-firefox/memory/jemalloc/crtsrc/jemalloc.c:4281 10 xul.dll nsScriptSecurityManager::CheckSameOriginURI caps/src/nsScriptSecurityManager.cpp:671 11 xul.dll ChangeTable obj-firefox/xpcom/build/pldhash.c:599 12 xul.dll PL_DHashTableOperate obj-firefox/xpcom/build/pldhash.c:661 13 xul.dll nsXULPDGlobalObject::cycleCollection::Traverse content/xul/document/src/nsXULPrototypeDocument.cpp:652 14 xul.dll xpc_CreateGlobalObject js/src/xpconnect/src/nsXPConnect.cpp:1008 15 xul.dll xul.dll@0xc9caf7 16 xul.dll nsJSContext::CreateNativeGlobalForInner dom/base/nsJSEnvironment.cpp:2538 17 xul.dll nsGlobalWindow::SetNewDocument dom/base/nsGlobalWindow.cpp:1980 18 xul.dll DocumentViewerImpl::InitInternal layout/base/nsDocumentViewer.cpp:956 19 xul.dll DocumentViewerImpl::Init layout/base/nsDocumentViewer.cpp:693 20 xul.dll nsDocShell::SetupNewViewer docshell/base/nsDocShell.cpp:7629 21 xul.dll nsDocShell::Embed docshell/base/nsDocShell.cpp:5723 22 xul.dll nsDocShell::CreateAboutBlankContentViewer docshell/base/nsDocShell.cpp:6496 23 xul.dll nsDocShell::EnsureContentViewer docshell/base/nsDocShell.cpp:6404 24 xul.dll nsDocShell::GetInterface docshell/base/nsDocShell.cpp:896 25 xul.dll xul.dll@0xb2ebb3 26 xul.dll nsGenericHTMLFrameElement::GetContentDocument content/html/content/src/nsGenericHTMLElement.cpp:3078 27 xul.dll nsHTMLIFrameElement::GetContentDocument content/html/content/src/nsHTMLIFrameElement.cpp:146 28 xul.dll NS_InvokeByIndex_P xpcom/reflect/xptcall/src/md/win32/xptcinvoke.cpp:102 29 xul.dll XPC_WN_GetterSetter js/src/xpconnect/src/xpcwrappednativejsops.cpp:1643 30 mozjs.dll js::Invoke js/src/jsinterp.cpp:700 31 mozjs.dll js::ExternalInvoke js/src/jsinterp.cpp:858 32 mozjs.dll js::JSProxyHandler::call js/src/jsproxy.cpp:248 33 mozjs.dll JSCrossCompartmentWrapper::call js/src/jswrapper.cpp:616 34 mozjs.dll js::JSProxy::call js/src/jsproxy.cpp:810 35 mozjs.dll js::proxy_Call js/src/jsproxy.cpp:1062 36 mozjs.dll js::Invoke js/src/jsinterp.cpp:693 37 mozjs.dll js::ExternalInvoke js/src/jsinterp.cpp:858 38 mozjs.dll js::ExternalGetOrSet js/src/jsinterp.cpp:898 39 mozjs.dll js::JSProxyHandler::get js/src/jsproxy.cpp:131 40 xul.dll xpc::XrayWrapper<JSCrossCompartmentWrapper,xpc::CrossCompartmentXray>::get js/src/xpconnect/wrappers/XrayWrapper.cpp:752 41 mozjs.dll js::JSProxy::get js/src/jsproxy.cpp:778 42 mozjs.dll js::proxy_GetProperty js/src/jsproxy.cpp:895 43 mozjs.dll JSObject::getProperty js/src/jsobj.h:1189 44 mozjs.dll js::Interpret js/src/jsinterp.cpp:4220 45 mozjs.dll js::RunScript js/src/jsinterp.cpp:657 46 mozjs.dll js::Invoke js/src/jsinterp.cpp:737 47 mozjs.dll CallOrConstructBoundFunction js/src/jsfun.cpp:2289 48 mozjs.dll js::Interpret js/src/jsinterp.cpp:4801 49 mozjs.dll js::RunScript js/src/jsinterp.cpp:657 50 mozjs.dll js::Invoke js/src/jsinterp.cpp:737 51 mozjs.dll js::ExternalInvoke js/src/jsinterp.cpp:858 52 mozjs.dll JS_CallFunctionValue js/src/jsapi.cpp:5009 53 xul.dll nsXPCWrappedJSClass::CallMethod js/src/xpconnect/src/xpcwrappedjsclass.cpp:1700 54 xul.dll nsXPCWrappedJS::CallMethod js/src/xpconnect/src/xpcwrappedjs.cpp:588 55 xul.dll PrepareAndDispatch xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:114 56 xul.dll SharedStub xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:141 57 xul.dll nsTimerImpl::Fire xpcom/threads/nsTimerImpl.cpp:428

all the crashes have the same offset-from-null, cx->compartment is NULL. xpc_CreateGlobalObject makes me think that we're creating something and haven't entered a compartment yet.

sfink was running into a very similar issue, this should provide a less brittle fix

Pushed to try.

Comment on attachment 508656 [details] [diff] [review] patch I like this approach much better. And I noticed you moved the compartment entry to cover some more code that needs it, which might fix bug 629775 (which I still haven't looked at.)

Seems to pass try. Waiting for blake's review.

Probably good to get this into the beta so we can see whether it helps.

review ping

ping