Bug 182154 – Layout Test http/tests/security/cross-origin-worker-indexeddb.html is flaky

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[Matt Lewis]

Created attachment 332324 [details]
Crash Log

The following layout test is a flaky crash on macOS High Sierra

http/tests/security/cross-origin-worker-indexeddb.html

Probable cause:

This looks to be an older crash as it goes beyond the range of the flakiness dashboard. The test has been fixed in the past for other flakiness.

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fsecurity%2Fcross-origin-worker-indexeddb.html

https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK2%20(Tests)/r227624%20(2518)/results.html
https://build.webkit.org/builders/Apple%20High%20Sierra%20Release%20WK2%20(Tests)/builds/2518

[Alexey Proskuryakov]

Is this reproducible? Not quite sure what to make out of this crash log - it looks like memory corruption, but hits EXC_BREAKPOINT somehow.

[Matt Lewis]

Yes. I was able to reproduce this with run-webkit-tests --no-retry-failure http/tests/security/cross-origin-worker-indexeddb.html --verbose --iterations=100

[Alexey Proskuryakov]

I could reproduce too, got a crash that looked like this:

Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes:       0x0000000000000001, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Illegal instruction: 4
Termination Reason:    Namespace SIGNAL, Code 0x4
Terminating Process:   exc handler [0]

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.WebCore             	0x000000010f386cd1 WebCore::IDBServer::UniqueIDBDatabase::~UniqueIDBDatabase() + 849 (UniqueIDBDatabase.cpp:79)
1   com.apple.WebCore             	0x000000010f3c5ec5 WebCore::IDBServer::UniqueIDBDatabase::maybeFinishHardClose()::$_2::operator()() const + 85 (memory:2397)
2   com.apple.JavaScriptCore      	0x000000011eac10b7 WTF::dispatchFunctionsFromMainThread() + 423 (MainThread.cpp:133)
3   com.apple.JavaScriptCore      	0x000000011eac3b8f WTF::timerFired(__CFRunLoopTimer*, void*) + 31 (MainThreadMac.mm:111)

[Radar WebKit Bug Importer]

<rdar://problem/37011861>

[Brady Eidson]

Just tried with ToT as of today, both debug and release, could not reproduce with the command listed here.

Not even after upping it to 1000 iterations.

[Brady Eidson]

Additionally it's not showing on the flakiness dashboard.

I think this got licked at some point.

[Matt Lewis]

I was able to verify what Brady was seeing and the test is passing now.