Bug 93891

Summary:	Hang when recursing in _cairo_scaled_font_reset_cache()
Product:	cairo	Reporter:	Hans Petter Jansson <hpj>
Component:	general	Assignee:	Chris Wilson <chris>
Status:	RESOLVED FIXED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	medium	CC:	freedesktop
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	0001-scaled-font-Fix-deadlock-when-recursing-in-_cairo_sc.patch evince-11.3test.pdf gdb.txt

Description Hans Petter Jansson 2016-01-27 19:03:52 UTC

The destruction of a scaled font can indirectly trigger the destruction
of a second scaled font, causing the global cache to be locked twice in
the same thread.

This can cause applications to deadlock when rendering certain PDF documents.

Comment 1 Hans Petter Jansson 2016-01-27 19:06:31 UTC

Created attachment 121328 [details] [review]
0001-scaled-font-Fix-deadlock-when-recursing-in-_cairo_sc.patch

Patch that fixes the bug here.

Comment 2 Behdad Esfahbod 2016-08-02 05:06:28 UTC

I don't pretend to know the glyph cache anymore, but I trust you with your analysis.

Humm, let's see any of the surviving maintainers can push this in.  Anyone?

Comment 3 Hans Petter Jansson 2016-08-02 20:59:51 UTC

Created attachment 125494 [details]
evince-11.3test.pdf

PDF that triggers the bug if viewed in evince (Cairo 1.12.16).

Comment 4 Hans Petter Jansson 2016-08-02 21:00:58 UTC

Created attachment 125495 [details]
gdb.txt

gdb trace. See thread 6.

Comment 5 Behdad Esfahbod 2016-08-02 21:22:13 UTC

Thanks.  Verified fixed and pushed to master.

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