1427035 - stylo: Crash in style::stylist::{{impl}}::add_stylesheet<T>

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Cervantes Yu [:cyu] [:cervantes]]

This bug was filed from the Socorro interface and is
report bp-1d1f1edd-f93b-4191-a2c3-c82ea0171224.
=============================================================

Seen while looking at nightly crash stats - top crash of fennec using 20171223100227. 32 crashes/30 installs in 2 days.

Top 10 frames of crashing thread:

0 libxul.so style::stylist::{{impl}}::add_stylesheet<style::gecko::data::GeckoStyleSheet> src/libcore/ptr.rs:328
1 libxul.so geckoservo::glue::Servo_StyleSet_FlushStyleSheets servo/components/style/stylist.rs:110
2 libxul.so mozilla::ServoStyleSet::UpdateStylist layout/style/ServoStyleSet.cpp:1378
3 libxul.so mozilla::ServoStyleSet::BuildFontFeatureValueSet layout/style/ServoStyleSet.cpp:1349
4 libxul.so mozilla::StyleSetHandle::Ptr::BuildFontFeatureValueSet layout/style/StyleSetHandleInlines.h:364
5 libxul.so nsPresContext::FlushFontFeatureValues layout/base/nsPresContext.cpp:3150
6 libxul.so mozilla::PresShell::DoFlushPendingNotifications layout/base/PresShell.cpp:4205
7 libxul.so nsViewManager::CallWillPaintOnObservers view/nsViewManager.cpp:1138
8 libxul.so nsViewManager::ProcessPendingUpdates view/nsViewManager.cpp:1100
9 libxul.so nsRefreshDriver::Tick layout/base/nsRefreshDriver.cpp:2046

=============================================================

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Looks like null derefs and there are no URLs or comments... Also the stack points to a function which is somewhat big, so it's not clear what the null object is...

I can try to take a more careful look, or adding a couple of extra assertions around the objects that function touches that come from Gecko to see what's up with that.

Comment 2

[Chris Peterson [:cpeterson]]

Setting priority P3 because this crash's volume is very low.

Mac crash report bp-58a90d85-259c-475a-994e-0b6610180107 has crash reason "Locked::read_with called with a guard from an unrelated SharedRwLock".

Comment 3

[Emilio Cobos Álvarez (:emilio)]

(In reply to Chris Peterson [:cpeterson] from comment #2)
> Setting priority P3 because this crash's volume is very low.
> 
> Mac crash report bp-58a90d85-259c-475a-994e-0b6610180107 has crash reason
> "Locked::read_with called with a guard from an unrelated SharedRwLock".

That is... "impossible", since we only use a single SharedRwLock...

Comment 4

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

Closing because no crashes reported for 12 weeks.