WebCore crash iOS 13.3.1

Date/Time:           2020-05-14 09:06:44.6238 +0800
Launch Time:         2020-05-13 09:41:03.6508 +0800
OS Version:          iPhone OS 13.3.1 (17D50)
Release Type:        User
Baseband Version:    5.30.01
Report Version:      104


Exception Type:  EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x00000001a6465760
Termination Signal: Trace/BPT trap: 5
Termination Reason: Namespace SIGNAL, Code 0x5
Terminating Process: exc handler [511]
Triggered by Thread:  21

Thread 21 name:  Heap Helper Thread
Thread 21 Crashed:
0   WebCore                       0x00000001a6465760 0x1a49a7000 + 28043104
1   WebCore                       0x00000001a6465760 0x1a49a7000 + 28043104
2   WebCore                       0x00000001a4d99bc0 0x1a49a7000 + 4139968
3   WebCore                       0x00000001a4d9a900 0x1a49a7000 + 4143360
4   JavaScriptCore                 0x00000001ac585fe0 0x1abb55000 + 10686432
5   JavaScriptCore                 0x00000001ac585cb8 0x1abb55000 + 10685624
6   JavaScriptCore                 0x00000001abdc97dc 0x1abb55000 + 2574300
7   JavaScriptCore                 0x00000001abb56f1c 0x1abb55000 + 7964
8   libobjc.A.dylib               0x000000019cb856d0 0x19cb64000 + 136912
9   libobjc.A.dylib               0x000000019cb855c8 0x19cb64000 + 136648
10  JavaScriptCore                 0x00000001abda2e74 0x1abb55000 + 2416244
11  JavaScriptCore                 0x00000001abd98468 0x1abb55000 + 2372712
12  JavaScriptCore                 0x00000001ac23c158 0x1abb55000 + 7237976
13  JavaScriptCore                 0x00000001ac2394a0 0x1abb55000 + 7226528
14  JavaScriptCore                 0x00000001ac239ce0 0x1abb55000 + 7228640
15  JavaScriptCore                 0x00000001ac21bc94 0x1abb55000 + 7105684
16  JavaScriptCore                 0x00000001abb86558 0x1abb55000 + 202072
17  JavaScriptCore                 0x00000001abb87030 0x1abb55000 + 204848
18  JavaScriptCore                 0x00000001abb60688 0x1abb55000 + 46728
19  JavaScriptCore                 0x00000001abb9f734 0x1abb55000 + 304948
20  JavaScriptCore                 0x00000001abba12a4 0x1abb55000 + 311972
21  libsystem_pthread.dylib       0x000000019cb5dd8c 0x19cb53000 + 44428
22  libsystem_pthread.dylib       0x000000019cb6176c 0x19cb53000 + 59244

The crash report

The device is iPhone X

WebCore crash iOS 13.3.1

Please post the full crash report.

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—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

There is the full crash report, Thanks

https://pastebin.com/raw/KDcUT0t2

There is the full crash report

Thanks.

I symbolicated your log and got a crashing thread backtrace like this:

0   WebCore                 … _WebThreadLock() (.cold.2) + 40
1   WebCore                 … _WebThreadLock() (.cold.2) + 40
2   WebCore                 … _WebThreadLock() + 336
3   WebCore                 … WebThreadLock + 112
4   JavaScriptCore          … JSC::JSLock::lock(long) + 48
5   JavaScriptCore          … JSC::JSLockHolder::JSLockHolder(JSC::VM*) …
6   JavaScriptCore          … JSContextGroupRelease + 32…
7   JavaScriptCore          … -[JSVirtualMachine dealloc] + 28…
8   libobjc.A.dylib         … AutoreleasePoolPage::releaseUntil(objc_obj…
9   libobjc.A.dylib         … objc_autoreleasePoolPop + 224…
10  JavaScriptCore          … scanExternalObjectGraph(JSC::VM&, JSC::Slo…
11  JavaScriptCore          … JSC::JSCallbackObject<JSC::JSAPIWrapperObj…
12  JavaScriptCore          … JSC::SlotVisitor::drain(***::MonotonicTime…
13  JavaScriptCore          … JSC::SlotVisitor::drain(***::MonotonicTime…
14  JavaScriptCore          … JSC::SlotVisitor::drainFromShared(JSC::Slo…
15  JavaScriptCore          … ***::SharedTaskFunctor<void (), JSC::Heap:…
16  JavaScriptCore          … ***::ParallelHelperClient::runTask(***::Re…
17  JavaScriptCore          … ***::ParallelHelperPool::Thread::work() + …
18  JavaScriptCore          … ***::Detail::CallableWrapper<***::Automati…
19  JavaScriptCore          … ***::Thread::entryPoint(***::Thread::NewTh…
20  JavaScriptCore          … ***::wtfThreadEntryPoint(void*) + 12
21  libsystem_pthread.dylib … _pthread_start + 156
22  libsystem_pthread.dylib … thread_start + 8

This has all the classic symptoms of a memory management problem. Note that frame 9 is the Objective-C runtime draining an autorelease pol and frame 7 is a

JSVirtualMachine

Unfortunately it’s hard to tell whether this problem is triggered by a bug in your code or a bug in the system. Frankly, I suspect it’s the latter, but I still have a recommendation for you: Try running your app with the Standard Memory Debugging Tools to see if they offer any hints as to what’s going wrong.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"