I try to convert QString to const *char, it generate General Protection fault. I could't understand about that.

dmesg

code that generate General Protection fault

When I checked with gdb, segment fault is generated in "vfprintf".

gdb result

1. What does mean "General Protection"
2. I tried to run this code other system, it works well. Are there any conditions that could cause problems?
   1. redhat 6 / qt 4.6
   2. redhat 7 / qt 4.8

• I have already tried converting to "toStdString, toLocal8Bit, etc..."