730282 - Firefox Crash @ mozilla::SignalTracerThread

Status: RESOLVED FIXED

(Core :: Widget, defect)

Description

[Marcia Knous [:marcia]]

Low volume Mac crash. https://crash-stats.mozilla.com/report/list?signature=mozilla::SignalTracerThread

Comments mention:

Clicked "restart now" in one of several addons I removed or disabled in the addon manager

I restarted Firefox to apply a new Firefox upgrade.

https://crash-stats.mozilla.com/report/index/60609c30-812f-44d6-88d1-728ab2120223

Frame 	Module 	Signature 	Source
0 	XUL 	mozilla::SignalTracerThread 	
1 	XUL 	-[GeckoNSApplication sendEvent:] 	widget/cocoa/nsAppShell.mm:193
2 	XUL 	ProcessPendingGetURLAppleEvents 	toolkit/xre/MacApplicationDelegate.mm:151
3 	XUL 	CommandLineServiceMac::SetupMacCommandLine 	toolkit/xre/nsCommandLineServiceMac.cpp:101
4 	XUL 	XRE_main 	toolkit/xre/nsAppRunner.cpp:1625
5 	firefox 	main 	browser/app/nsBrowserApp.cpp:189
6 	firefox 	firefox@0x1573

Comment 1

[Scoobidiver (away)]

It first appeared in 12.0a1/20120107.
There is a Widget Gtk version on Linux.

Comment 2

[Steven Michaud [:smichaud] (Retired)]

Recategorizing because these also happen on Linux.

Comment 3

[Steven Michaud [:smichaud] (Retired)]

The crash stacks on Linux are much more informative:

0 	libxul.so 	mozilla::SignalTracerThread 	Mutex.h:106
1 	libxul.so 	TracerCallback 	widget/gtk2/WidgetTraceEvent.cpp:58
2 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x44a5c 	
3 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x4078f 	
4 	libxul.so 	mozilla::SignalTracerThread 	Mutex.h:188
5 		@0x9 	
6 	libxul.so 	nsAppShell::ScheduleNativeEventCallback 	widget/gtk2/nsAppShell.cpp:157
7 		@0x7fe981c4e01f 	
8 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x45257 	
9 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x2f4827 	
10 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x2f483f 	
11 	libpthread-2.13.so 	libpthread-2.13.so@0x9fff 	
12 	libglib-2.0.so.0.3000.0 	libglib-2.0.so.0.3000.0@0x45428 	
13 	libxul.so 	nsAppShell::ProcessNextNativeEvent 	widget/gtk2/nsAppShell.cpp:162
...

Comment 4

[Steven Michaud [:smichaud] (Retired)]

> It first appeared in 12.0a1/20120107.

bp-2027c29e-c6e5-494d-ab45-8554f2120128

On Linux the first one is in build 20120105083933:

bp-76c558bf-ebac-4799-a0a1-584582120105

Comment 5

[Steven Michaud [:smichaud] (Retired)]

(Following up comment #4)

I can't find any obvious candidate for this bug's trigger among the patches landed just before the 2012-01-05 nightlies.  In any case this crash is too low volume to use build ids to identify the exact build they started in.

Comment 6

[Steven Michaud [:smichaud] (Retired)]

On Linux these crashes appear to take place at the following line, probably after a call to mozilla::CleanUpWidgetTracing() had invalidated sMutex:

http://hg.mozilla.org/releases/mozilla-aurora/annotate/cd3f31d128b8/widget/gtk2/WidgetTraceEvent.cpp#l102

Comment 7

[Steven Michaud [:smichaud] (Retired)]

On OS X I'd bet they take place at the following line, for the same reason:

http://hg.mozilla.org/mozilla-central/annotate/58dd942011a8/widget/cocoa/WidgetTraceEvent.mm#l77

Comment 8

[Steven Michaud [:smichaud] (Retired)]

On Windows we *should* be seeing crashes at the following line:

http://hg.mozilla.org/mozilla-central/annotate/58dd942011a8/widget/windows/WidgetTraceEvent.cpp#l134

I'm not sure why we don't.

Comment 9

[(not currently active) Ted Mielczarek]

Benoit added some APIs to let us enable this tracing functionality in a scriptable manner, for use with the profiling extension. This functionality is off by default (and only normally enabled via environment variable), so it's unlikely to affect users that haven't installed the profiling extension.

Steven: the widget-specific bits are fairly different, so it wouldn't surprise me if Windows doesn't crash here.

In fact, we have a known Linux shutdown crash in this code (bug 710296), which is why we didn't enable it on Linux Talos yet.

Comment 10

[Benoit Girard (:BenWa)]

I looked through the crash reports, the only extensions that I know are using this are 'about:jank' and 'Gecko Profiler', none of which show up in the crash report. Could they show up under <id>@jetpack?

Comment 11

[Steven Michaud [:smichaud] (Retired)]

These crashes should be very easy to fix:  Just make CleanUpWidgetTracing() null out sMutex (on OS X and Linux).

And for good measure, on Windows CleanUpWidgetTracing() should null out sEventHandle.

I don't know if widget tracing has been implemented on other platforms.  But if it has, similar changes would be needed there.

Comment 12

[Steven Michaud [:smichaud] (Retired)]

(Following up comment #11)

Oops, the code already does this on OS X and Linux.  I meant to say that, on these platforms, SignalTracerThread() should check if sMutex or sCondVar is NULL.

Patch coming up.

Comment 13

[Steven Michaud [:smichaud] (Retired)]

Attachment: Fix

Comment 15

[(not currently active) Ted Mielczarek]

Comment on attachment 603449 [details] [diff] [review]
Fix

Review of attachment 603449 [details] [diff] [review]:
-----------------------------------------------------------------

Seems plausible. It's definitely going to crash if either of those are NULL. You'll want to watch the Talos Tp5 runs on Tinderbox, because we run Windows/Mac with this tracing enabled there.

Comment 16

[Steven Michaud [:smichaud] (Retired)]

Comment on attachment 603449 [details] [diff] [review]
Fix

Landed on mozilla-inbound:
http://hg.mozilla.org/integration/mozilla-inbound/rev/1c7831aa244d

Comment 17

[Marco Bonardo [:mak]]

https://hg.mozilla.org/mozilla-central/rev/1c7831aa244d