OSPreferences::GetInstanceAddRefed() is not safe to call off-main-thread
Categories
(Core :: Internationalization, defect)
Tracking
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| Tracking | Status | |
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| firefox90 | --- | fixed |
People
(Reporter: jfkthame, Assigned: jfkthame)
Details
Attachments
(1 file)
The method gfxDWriteFontFamily::LocalizedName uses OSPreferences::GetInstanceAddRefed to get a reference to the preferences service; but LocalizedName may be called off-main-thread, which is bad because OSPreferences doesn't use thread-safe refcounting.
The bug can be demonstrated by running a debug Windows build with gfx.e10s.font-list.shared set to false, and then opening about:preferences. The thread that intends to populate the Font menu will crash with a thread-safety assertion.
In practice it seems highly unlikely this would cause problems, although maybe opening Preferences and then instantly shutting down the browser might possibly cause a race resulting in incorrect behavior (e.g. a leak or a double-free of the OSPreferences singleton). Nevertheless, we should fix it to avoid any risk.
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Assignee | |
Comment 1•3 years ago
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Updated•3 years ago
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Pushed by jkew@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/76dd6379cc01 Make OSPreferences refcounting thread-safe, because of potential OMT usage from gfxDWriteFontFamily. r=dminor
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Comment 3•3 years ago
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| bugherder | ||
Description
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