Module exec 

exec a user program by loading the binary and replace the current address space TODO rework this code, this is only POC

Functions

enter_usermode 🔒 ^⚠

Build an iretq frame on the current (kernel) stack and iretq into ring 3. We set CS/SS to the user segments with RPL=3, and RFLAGS with IF set so the user program runs with interrupts enabled.

exec

loads the program into current address spacecreate and map a user stackset TSS RSP0 so interrupts from user mode land on the kernel stackswitch to user mode via iretq (point of no return)