Some typos in this book. about linux-kernel-programming

[kaiwan]

Hi @kaiwan, Thanks for writing this excellent book.
Thank you!
After reading this book thoroughly, i found some typos which you may could help to correct it.

1. In Page 155, Double 'w' used at line "// ch4/helloworld_lkm/hellowworld_lkm.c". red line marked as below.
   

Thanks; now marked in the README.md under the 'Known Errata' section

2. In Page 307, at line " first and second columns in the preceding code block that represent the TGID and PID respectively". From the configure below, In fact, " first and second columns in the preceding code block that represent the PID and TGID respectively"
   

This typo has already been caught :-)
See in the 'Known Errata'

3. In Page 656, at last line, "In place of atomic64_dec_if_positive(), use
   atomic64_dec_if_positive()." It may should be "In place of atomic_dec_if_positive(), use
   atomic64_dec_if_positive()."
   

Thanks; now marked in the README.md under the 'Known Errata' section

Thanks Hengwei
Thank you very much