2009-11-05 19:15:01     Qt application unstable

Document created by Aaronwu Employee on Aug 19, 2013
Version 1Show Document
  • View in full screen mode

2009-11-05 19:15:01     Qt application unstable

Bryan DE FARIA (UNITED STATES)

Message: 82102   

 

Hello,

 

 

I am currently developing a Qt application with qt-embedded 4.4.3 libraries compiled with:

 

./configure -shared -depths 16-no-cups -no-webkit -embedded bfin -little-endian -qt-mouse-tslib -L/home/cmd-ubuntu/blackfin-sources/uClinux/current/staging/usr/lib -I/home/cmd-ubuntu/blackfin-sources/uClinux/current/staging/usr/include -qvfb

 

 

I can launch my application but with time it crashes with :

 

Initializing QFontEngineQPF failed for /usr/local/Trolltech/QtEmbedded-4.4.3-bfin/lib/fonts/DejaVuSans.ttf

 

munmap of non-mmaped memory [00000000-00005000] by process 253 (tft)

 

QFontEngineQPF::remapFomrData: munmap failed! (Invalid argument)NULL pointer access

 

See bug1.txt

 

 

I tried to compile 4.5.3 libraries with the patches you provide for 4.5.0 but when I try to launch the application it crashes with:

 

Data access misaligned address violation

 

- Attempted misaligned data memory or data cache access.

 

See bug2.txt

 

 

What can I do to make it more stable?

 

 

 

bug2.txt

bug1.txt

QuoteReplyEditDelete

 

 

2009-11-05 22:03:00     Re: Qt application unstable

Sonic Zhang (CHINA)

Message: 82105   

 

It was said

 

Data access misaligned address violation

 

- Attempted misaligned data memory or data cache access.

 

 

 

So, figure out which code breaks this and your patch are welcome here.

QuoteReplyEditDelete

 

 

2009-11-05 22:35:02     Re: Qt application unstable

Yi Li (CHINA)

Message: 82106   

 

Also see this:

 

  blackfin.uclinux.org/gf/project/uclinux-dist/forum/?_forum_action=ForumMessageBrowse&thread_id=37048&action=ForumBrowse&forum_id=39

 

-YI

QuoteReplyEditDelete

 

 

2009-11-08 16:52:20     Re: Qt application unstable

Alex Williams (RUSSIAN FEDERATION)

Message: 82189   

 

> So, figure out which code breaks this and your patch are welcome here.

 

One question... How to find that place in source code, where missaligned access??? We must use debugger, compile Qt in debug mode, disassemble binary or how?..

QuoteReplyEditDelete

 

 

2009-11-08 21:29:11     Re: Qt application unstable

Yi Li (CHINA)

Message: 82191   

 

Alex,

 

You can try to analyze the trace:   docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:analyzing_traces

 

-Yi

QuoteReplyEditDelete

 

 

2009-11-08 22:45:17     Re: Qt application unstable

Sonic Zhang (CHINA)

Message: 82195   

 

You can debug qt by gdb via gdbserver.

QuoteReplyEditDelete

 

 

2009-11-09 18:15:23     Re: Qt application unstable

Alexander Buryak (UKRAINE)

Message: 82227   

 

Hello,

 

Try to compile with depths 24 support,

 

Then read this  comment

 

https://blackfin.uclinux.org/gf/project/uclinux-dist/forum/?_forum_action=ForumMessageBrowse&thread_id=37048&action=ForumBrowse&forum_id=39

 

 

 

Thanks,

 

Alexander

QuoteReplyEditDelete

 

 

2009-11-19 14:36:04     Re: Qt application unstable

Bryan DE FARIA (UNITED STATES)

Message: 82546   

 

Thank you Alexander!

 

I solved the Data access misaligned address violation in editing qscreenlinuxfb_qws.cpp from Qt sources. Basically, I just commented the line where Qt set the rgb16 mode (qt-4.5.1-fb-16bits.patch).

 

I don't know which mode it takes instead, but it seems to work well.

 

qt-4.5.1-fb-16bits.patch

Outcomes