true, I also faced same issue with linux 6.1.2

This is the best tutorial I have come across, thanks a ton!

I really liked rest of the articles as well. You have a knack for simplifying the complexity, keep up the good work.

I come from the bare metal side, taking first steps in embedded linux. Your example code works well on x86. I was trying to attempt it on a A7 cpu, changed the ARCH to arm-linux-gnueabihf in the makefile but it still complains.

Would be great if you could give some pointer on how and what to change for ARM based devices. Maybe add to the above article or write a new one whenever you can.

Thanks again

In most cases, yes. But this is just a tutorial about how to write chardev driver, not a production code. In the real world, apps buffer and buffer size might be dynamically declared somewhere else in a larger driver structure.

The off-by-one error is still there, but since the buffer length is 30, in practice it will not matter because that buffer will actually include the next two bytes (i.e. to 32). Not that I am excusing the error, just sayin’

Hello.
Thank you for the information. Something may be changed in the Linux kernel. I’ll check.