How to debug kernel log?

Question

I am trying to write scull device according to this tutorial : linux device drivers. My source is here my scull repo, where is dmesg2.err file with kern log dump. I had previously problem to initilize the char device kernel output weird dmesg of my driver module which I have fixed. The problem now is, when I try to read from the empty device /dev/scull0, I receive killed. Or when I try to write echo "abc" >/dev/stdin, then Segmentation fault. I would really like to learn to how to debug from the kern.log, but do not have skills for that yet (I am intermediate c, and basic of GAS asm), and therefor would like to have some really good book for debuging kernel + what skills I need to understand it. You could find the bug in the source but my intend is to solve these bugs by myself in the future. Thanks for advices.