[Interest] Crash when starting Qt5 rasterwindow on ARM/linuxfb

[Thomas Petazzoni]

Hello,

I am currently packaging Qt5 for the Buildroot embedded Linux build
system (http://buildroot.org).

I am therefore trying to get the 'rasterwindow' example (from
qtbase/examples/gui/rasterwindow/) to run with the 'linuxfb' graphics
backend on a ARM platform (currently a Cortex-A8 platform emulated by
Qemu).

I first got a segfault that I could fix, see the patch '[PATCH qtbase]
qlinuxfbscreen: fix crash in switchToGraphicsMode()' I just send to
this list.

But once this first easy issue was fixed, I got another segfault, which
this time requires more knowledge of Qt internals, which I don't have.

So, basically, I'm starting my application as follows:

./rasterwindow -platform linuxfb

and I get the following trace in gdb:

Program received signal SIGSEGV, Segmentation fault.
QFbBackingStore::QFbBackingStore (this=0x17588, window=0x7efffc34) at fbconvenience/qfbbackingstore.cpp:54
54	    (static_cast<QFbWindow *>(window->handle()))->setBackingStore(this);
(gdb) bt
#0  QFbBackingStore::QFbBackingStore (this=0x17588, window=0x7efffc34) at fbconvenience/qfbbackingstore.cpp:54
#1  0x768ac016 in QLinuxFbIntegration::createPlatformBackingStore (this=<optimized out>, window=0x7efffc34) at qlinuxfbintegration.cpp:87
#2  0x76f33438 in QBackingStore::QBackingStore (this=0x19008, window=0x7efffc34) at painting/qbackingstore.cpp:122

Does anyone has an idea? Should I be doing a formal bug report?

Thanks for your help,

Thomas Petazzoni
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com