On Fri, Aug 04, 2017 at 06:10:48PM -0700, Kevin Oberman
wrote:> multimedia/avidemux_qt4 has started dumping core with segfaults and other
> errors in libthread called from Qt4. I am suspicious that the real problem
> is in Qt4 and those errors were previously not detected and usually not
> causing a problem.
>
> The problem shows up with kernels at r320666 and later. The update on July
> 5 was:
> Add MAP_GUARD and use it for stack protection.
So the same userspace and application binaries on pre-r320666 works fine,
am I right ?
>
> Should I open a ticket for the Qt4 or should I spend more effort on whether
> it might be a kernel issue. (Pretty sure it's Qt4 at fault.) I might
also
> look into updating the port to use Qr5 as Qt4 is clearly starting to bitrot
> and support for Qt5 has already been added upstream.
Regardless of tickets, the only way to know what is going on is to debug
the app. Build everything with the debug symbols, crash it under debugger
control and obtain
- backtraces of all threads
- content of registers of the faulted thread
- disassembly of the function which faulted
- memory map of the application