The relationship between user and kernel virtual addresses has been discussed in a few questions before (links below), but as far as I understand it, the user process cannot read nor write to the Kernel addresses.
So, how does a user process share and receive data from the kernel?
Is it through memory? If so, where in the memory layout? Maybe CPU registers?
Related questions:
- What's the use of having a kernel part in the virtual memory space of Linux processes?
- Do the virtual address spaces of all the processes have the same content in their "Kernel" parts?
