Qt新手求教bug，大神们帮我看看

我用的是Qt4.8.5 ARM版本
我的程序不知道为什么偶尔就会出现这样的段错误，板上又不好调
下面是段错误后出现的报错信息
求大神解救啊
Program terminated with signal 11, Segmentation fault.
#0  0x408c0b5c in QTextEngine::shapeTextWithHarfbuzz(int) const ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
(gdb) bt
#0  0x408c0b5c in QTextEngine::shapeTextWithHarfbuzz(int) const ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#1  0x408c1918 in QTextEngine::shapeText(int) const ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#2  0x408c1d34 in QTextEngine::shape(int) const ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#3  0x408c79f8 in QTextEngine::shapeLine(QScriptLine const&) ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#4  0x408cf524 in QTextLine::cursorToX(int*, QTextLine::Edge) const ()
   from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#5  0x40d6d000 in ?? () from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4
#6  0x40d6d000 in ?? () from /root/arm-lib/Qt4.8.5-v2013/lib/libQtGui.so.4