Learning some Linux kernel programming tips

Linux kernel development is about learning from others and not reinventing the wheel. There is a set of rules to follow when doing kernel development. A whole chapter won't be enough to cover these rules. Thus, I picked two of the most relevant to me, those that are likely to change when programming for user space: error handling and message printing.

In user space, exiting from the main() method is enough to recover from all the errors that may have occurred. In the kernel, this is not the case, especially since it directly deals with the hardware. Things are different for message printing as well, and we will see that in this section.

Error handling

Returning the wrong error code for a given error can result in either the kernel or user space application misinterpreting and taking the wrong decision, producing unneeded behavior. To keep things clear, there are predefined errors in the kernel tree that cover almost every case...