1529794 - Crash in [@ local_unwind]

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect, P3)

Description

[Andrew McCreight [:mccr8]]

This bug is for crash report bp-fdc65f74-77eb-4ff5-8306-0ad4c0190221.

Top 10 frames of crashing thread:

0 kernelbase.dll local_unwind 
1 kernelbase.dll SpecialMBToWC 
2 kernel32.dll WideCharToMultiByteStub 
3 dwrite.dll ConvertToAnsi 
4 dwrite.dll ReadCompatibleFullWidthGlyphBits 
5 dwrite.dll OpenTypeFontFaceBuilder::WriteCompatibleFullWidthGlyphBits 
6 dwrite.dll FontFaceRegionBuilder::IBuilder::WriteRegionInternal 
7 dwrite.dll FontFaceRegionBuilder::IBuilder::WriteRegion 
8 dwrite.dll FontFaceConstructionTask::AddElementData 
9 dwrite.dll CacheWriter::AddElement 

This isn't a high volume crash, but it is happening cross multiple branches, so I figured I'd file it. These are mostly "EXCEPTION_IN_PAGE_ERROR_READ / STATUS_IO_DEVICE_ERROR" crashes. I'm not sure what that means.

Comment 1

[Lee Salzman [:lsalzman]]

This looks like a variation on bug 1407741. That bug seems to indicate this may be an invalid font that has some pointer taking us off into invalid memory or a DWrite bug triggered by some valid font feature. However, as that bug concludes, without a reproducible testcase, this is hard to resolve.

Comment 2

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

Since the crash volume is low (less than 5 per week), the severity is downgraded to S3. Feel free to change it back if you think the bug is still critical.

For more information, please visit auto_nag documentation.

Comment 3

[Jonathan Kew [:jfkthame]]

There may well be multiple code paths that can end up hitting this exception from deep inside dwrite; but at least one of them appears to be through gfxDWriteFontList::CreateFontEntry, which may make several DWrite API calls that might try to access font data. Any such call seems to be at risk of triggering an exception in case of disk errors or similar failures, so let's try wrapping them with an exception handler.

Comment 4

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1529794 - Protect DirectWrite usage in gfxDWriteFontList::CreateFontEntry with an exception handler. r=lsalzman

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2d0c8febe7b8
Protect DirectWrite usage in gfxDWriteFontList::CreateFontEntry with an exception handler. r=lsalzman

Comment 6

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/2d0c8febe7b8