1643987 - Crash in [@ mozilla::detail::PcqBase::Set] (MOZ_RELEASE_ASSERT(mActor)) if webgl.out-of-process==true

Status: RESOLVED WONTFIX

(Core :: Graphics: CanvasWebGL, defect, P5)

Description

[Calixte Denizet (:calixte)]

This bug is for crash report bp-6f3ca9f0-74aa-44e8-b64b-aa9510200605.

Top 10 frames of crashing thread:

0 libxul.so mozilla::detail::PcqBase::Set dom/canvas/ProducerConsumerQueue.h:264
1 libxul.so mozilla::detail::PcqBase::PcqBase dom/canvas/ProducerConsumerQueue.h:252
2 libxul.so mozilla::webgl::PcqProducer::PcqProducer dom/canvas/ProducerConsumerQueue.h:607
3 libxul.so mozilla::webgl::ProducerConsumerQueue::ProducerConsumerQueue dom/canvas/ProducerConsumerQueue.h:1018
4 libxul.so mozilla::webgl::ProducerConsumerQueue::Create dom/canvas/ProducerConsumerQueue.h:983
5 libxul.so mozilla::ClientWebGLContext::CreateHostContext dom/canvas/ClientWebGLContext.cpp:701
6 libxul.so mozilla::ClientWebGLContext::SetDimensions dom/canvas/ClientWebGLContext.cpp:691
7 libxul.so mozilla::dom::CanvasRenderingContextHelper::UpdateContext dom/canvas/CanvasRenderingContextHelper.cpp:240
8 libxul.so mozilla::dom::CanvasRenderingContextHelper::GetContext dom/canvas/CanvasRenderingContextHelper.cpp:192
9 libxul.so mozilla::dom::HTMLCanvasElement_Binding::getContext dom/bindings/HTMLCanvasElementBinding.cpp:297

There are 30 crashes (from 3 installations) in nightly 79 starting with buildid 20200605043926. In analyzing the backtrace, the regression may have been introduced by patch [1] to fix bug 1635956.

[1] https://hg.mozilla.org/mozilla-central/rev?node=801f886cf1b6

Comment 1

[David Parks [:handyman]]

I'm surprised there are so many of these but I assume the issue is the same as bug 1635065 -- WebGL remoting is not active so this is not live. Specifically, webgl.out-of-process is false [1] so execution should never get past [2], which it clearly does in that stack. So this must come from people changing the pref. Closing as invalid.

[1] https://searchfox.org/mozilla-central/rev/35b97af64a55d1d30caa4d6e9fabc1a7fbabc509/modules/libpref/init/StaticPrefList.yaml#9184
[2] https://searchfox.org/mozilla-central/rev/35b97af64a55d1d30caa4d6e9fabc1a7fbabc509/dom/canvas/ClientWebGLContext.cpp#715

Comment 2

[Ryan VanderMeulen [:RyanVM]]

Why does manually flipping a pref make this bug invalid?

Comment 3

[David Parks [:handyman]]

The pref is to turn on WebGL remoting (where WebGL graphics commands are run in the graphics process instead of the content process). It is expected to be turned on (by flipping the pref in StaticPrefList.yaml) sometime in 80. Until then, trying to use remote WebGL (by manually flipping the pref in about:config) will crash every time.

Comment 4

[Ryan VanderMeulen [:RyanVM]]

Should we be handling that more gracefully than crashing?

Comment 6

[Darkspirit]

Please close as duplicate of the bug that fixes this.

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jgilbert, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 8

[Simon Giesecke [:sg] [he/him]]

As I understand, Bug 1607940 was fixed in FF80, but we are still seeing these crashes. Jeff, could you give an update on that? Is this a real issue now?

Comment 9

[Kelsey Gilbert [:jgilbert]]

No, this is people playing with broken prefs. We should entirely remove the busted path but I don't want more churn than necessary right now.

Comment 10

[Andrew McCreight (out of office until 8/21) [:mccr8]]

About 7% of the OSX crashes (10 crashes) for the December 2 Nightlies had this signature.

Comment 11

[Andrew McCreight (out of office until 8/21) [:mccr8]]

Sorry, Windows not OSX. For example: bp-4f496055-6b0c-4823-8b2f-836c50201203