Filed by: smolnar [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=338973288&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/DOo2JMoPRUqsQGjdShP9zg/runs/0/artifacts/public/logs/live_backing.log

INFO -  TEST-START | org.mozilla.geckoview.test.NavigationDelegateTest.onNewSession_childShouldLoad
[task 2021-05-06T18:45:25.412Z] 18:45:25     INFO -  org.mozilla.geckoview.test | INSTRUMENTATION_RESULT: shortMsg=Process crashed.
[task 2021-05-06T18:45:25.412Z] 18:45:25     INFO -  org.mozilla.geckoview.test | INSTRUMENTATION_CODE: 0
[task 2021-05-06T18:45:25.420Z] 18:45:25     INFO -  org.mozilla.geckoview.test | adb_returncode=0
[task 2021-05-06T18:45:25.422Z] 18:45:25     INFO -  Passed: 318
[task 2021-05-06T18:45:25.422Z] 18:45:25     INFO -  Failed: 0
[task 2021-05-06T18:45:25.422Z] 18:45:25     INFO -  Todo: 40
[task 2021-05-06T18:45:25.422Z] 18:45:25     INFO -  SUITE-END | took 314s
[task 2021-05-06T18:45:25.507Z] 18:45:25     INFO -  mozcrash Copy/paste: /builds/worker/fetches/minidump_stackwalk/minidump_stackwalk /tmp/tmplWpREt/6bf0278a-4050-8d78-b02d-6d568caaed3c.dmp /builds/worker/workspace/build/symbols
[task 2021-05-06T18:45:31.253Z] 18:45:31     INFO -  mozcrash Saved minidump as /builds/worker/workspace/build/blobber_upload_dir/6bf0278a-4050-8d78-b02d-6d568caaed3c.dmp
[task 2021-05-06T18:45:31.253Z] 18:45:31     INFO -  mozcrash Saved app info as /builds/worker/workspace/build/blobber_upload_dir/6bf0278a-4050-8d78-b02d-6d568caaed3c.extra
[task 2021-05-06T18:45:31.262Z] 18:45:31  WARNING -  PROCESS-CRASH | org.mozilla.geckoview.test.NavigationDelegateTest.onNewSession_childShouldLoad | application crashed [@ mozilla::dom::ContentParent::Pid() const]
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -  Crash dump filename: /tmp/tmplWpREt/6bf0278a-4050-8d78-b02d-6d568caaed3c.dmp
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -  Operating system: Android
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -                    0.0.0 Linux 3.10.0+ #260 SMP PREEMPT Fri May 19 12:48:14 PDT 2017 x86_64
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -  CPU: amd64
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -       family 6 model 6 stepping 3
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -       4 CPUs
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -  GPU: UNKNOWN
[task 2021-05-06T18:45:31.262Z] 18:45:31     INFO -  Crash reason:  SIGSEGV /0x00000080
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -  Crash address: 0x0
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -  Process uptime: not available
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -  Thread 15 (crashed)
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -   0  libxul.so!mozilla::dom::ContentParent::Pid() const [ContentParent.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 3185 + 0xc]
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      rax = 0xe5e5e5e5e5e5e5e5   rdx = 0x0000000000000001
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      rcx = 0x00007ec7edcc8450   rbx = 0x0000000000000000
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      rsi = 0x0000000000000000   rdi = 0x00007ec7d1667000
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc66b0   rsp = 0x00007ec7edcc66b0
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -       r8 = 0x0000000000010001    r9 = 0x0000000000000000
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      r10 = 0x0000000000000000   r11 = 0x0000000000000246
[task 2021-05-06T18:45:31.263Z] 18:45:31     INFO -      r12 = 0x00000000ffffffff   r13 = 0x00007ec7cd4e0870
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -      r14 = 0x00007ec7cd59cda8   r15 = 0x00007ec7cd59cd60
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -      rip = 0x00007ec7e4d6d33a
INFO -      Found by: given as instruction pointer in context
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -   1  libxul.so!(anonymous namespace)::ParticularProcessPriorityManager::SetPriorityNow(mozilla::hal::ProcessPriority) [ProcessPriorityManager.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 695 + 0x8]
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6830   rsp = 0x00007ec7edcc66c0
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -      rip = 0x00007ec7e4db36ec
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -      Found by: previous frame's frame pointer
[task 2021-05-06T18:45:31.264Z] 18:45:31     INFO -   2  libxul.so!(anonymous namespace)::ParticularProcessPriorityManager::Notify(nsITimer*) [ProcessPriorityManager.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 641 + 0x12]
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6860   rsp = 0x00007ec7edcc6840
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      rip = 0x00007ec7e4db3309
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      Found by: previous frame's frame pointer
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -   3  libxul.so!{virtual override thunk({offset(-8)}, (anonymous namespace)::ParticularProcessPriorityManager::Notify(nsITimer*))} + 0xd
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6870   rsp = 0x00007ec7edcc6870
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      rip = 0x00007ec7e4db339d
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      Found by: previous frame's frame pointer
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -   4  libxul.so!nsTimerImpl::Fire(int) [nsTimerImpl.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 565 + 0xe]
[task 2021-05-06T18:45:31.265Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6920   rsp = 0x00007ec7edcc6880
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -      rip = 0x00007ec7e2753b31
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -      Found by: previous frame's frame pointer
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -   5  libxul.so!nsTimerEvent::Run() [TimerThread.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 252 + 0x14]
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6960   rsp = 0x00007ec7edcc6930
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -      rip = 0x00007ec7e2734385
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -      Found by: previous frame's frame pointer
[task 2021-05-06T18:45:31.266Z] 18:45:31     INFO -   6  libxul.so!mozilla::RunnableTask::Run() [TaskController.cpp:c9980e971a31b2bd47783dc4a9a26fca4a4c57d6 : 482 + 0x11]
[task 2021-05-06T18:45:31.267Z] 18:45:31     INFO -      rbp = 0x00007ec7edcc6df0   rsp = 0x00007ec7edcc6970
[task 2021-05-06T18:45:31.267Z] 18:45:31     INFO -      rip = 0x00007ec7e2743c8a
<...>

It looks to me like the timer for a ParticularProcessPriorityManager is running after the manager PPPM has been destroyed.

The timer gets cancelled in ShutDown when the ContentParent is destroyed, but I guess if the PPPM gets destroyed for some other reason then we fail to do that.

Bug 1710153 is the public version of this crash. It has happened a few times, and the same poison values are seen in the registers. I'm still not sure how this can happen, but given that the failures are all in a single specific set of Android unit tests, I'd surmise that the tests do something weird with creating and shutting down content process that exposes this issue.

I'll mark this sec-moderate because it is only being seen in an Android unit test.

Properly shut down ParticularProcessPriorityManager when destroying it. r=gsvelto
https://hg.mozilla.org/integration/autoland/rev/6751f446bdf06902c0077de692ce36fd37ffb7f1
https://hg.mozilla.org/mozilla-central/rev/6751f446bdf0

I don't think this is a regression from my patch. The instance in comment 0 happened after my patch was backed out and before it relanded, AFAICT. But I'm not sure what actually caused it. Very weird coincidence.

OK, timing seemed pretty sus to me, but probably not worth losing any sleep over.

It looks like this crash is continuing to happen, which isn't great.