1718611 - Crash in [@ _dispatch_sema4_signal] for macOS 10.13

Status: RESOLVED WORKSFORME

(Core :: Graphics: Text, defect)

Description

[Gabriele Svelto [:gsvelto]]

Crash report: https://crash-stats.mozilla.org/report/index/9af959a2-208a-4724-bd51-8f6b30210621

Reason: EXC_BAD_INSTRUCTION / EXC_I386_INVOP

Top 10 frames of crashing thread:

0 libdispatch.dylib _dispatch_sema4_signal 
1 libdispatch.dylib _dispatch_semaphore_signal_slow 
2 CoreGraphics CGFontStrikeGetDeltaSize 
3 CoreGraphics CGFontCacheUnlockStrike 
4 CoreGraphics CGGlyphBuilder::unlock_glyph_bitmaps 
5 CoreGraphics render_glyphs 
6 CoreGraphics draw_glyph_bitmaps 
7 CoreGraphics ripc_DrawGlyphs 
8 CoreGraphics draw_glyphs 
9 CoreText DrawGlyphsAtPositions 

This is a macOS-specific crash involving font rendering. Since it's happening fairly deep inside Apple code it's unclear to me if it's our code triggering the problem or if it's Apple fault. The issue seems to be related to synchronization as all crashes have the following crash info entry:

      "abort_cause": "15",
      "message": "BUG IN CLIENT OF LIBDISPATCH: Use-after-free of dispatch_semaphore_t or dispatch_group_t",
      "module": "/usr/lib/system/libdispatch.dylib"

Comment 1

[Jonathan Kew [:jfkthame]]

This seems to be specific to older macOS versions -- the reports are almost exclusively from 10.13 (I found just one from 10.14, while there are dozens from 10.13), which I think suggests it may well be a thread-related bug in Apple's frameworks, fixed in newer releases.

Comment 2

[Gabriele Svelto [:gsvelto]]

(In reply to Jonathan Kew (:jfkthame) from comment #1)

This seems to be specific to older macOS versions -- the reports are almost exclusively from 10.13 (I found just one from 10.14, while there are dozens from 10.13), which I think suggests it may well be a thread-related bug in Apple's frameworks, fixed in newer releases.

Ah yes, definitely something with macOS then. I suppose we should just close it as INVALID then.

Comment 3

[Wayne Mery (:wsmwk)]

top 5 crash for Macs on Thunderbird 91.3.0. And indeed all OS X 10.13, searching back three months.

Comment 4

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

Closing because no crashes reported for 12 weeks.