Write your first Linux kernel module
Maybe it's worth emphasizing that writing kernel code is a very responsible task, not to be taken lightly. Hackers coming from a userspace background tend to think it's just "userspace with a few quirks" which is grossly wrong: your code has to be completely free of bugs, as a dangling pointer, for instance, won't just send you a friendly SIGSEGV and terminate your ass, it will crash the whole system, leading to consequences for everyone who relies on its stability. Just imagine introducing a bug which crashes a Linux-based life support system. You could be responsible for endangering human lives. (I ageee that Linux isn't a sane choice here, but just for the sake of the argument.)Also, standards to get your pull requests merged into mainline Linux are insanely high, but even given that, you can never rely solely on maintainers' code review to catch your mistakes. Take kernel hacking seriously.