From Operating System Concepts
The kernel creates a new virtual address space in two situations: when a process runs a new program with the exec() system call and when a new process is created by the fork() system call. The first case is easy. When a new program is executed, the process is given a new, completely empty virtual address space. It is up to the routines for loading the program to populate the address space with virtual memory regions.
When a process runs a new program with exec(), it will create a new and empty virtual address space. Does it also release all the page frames in the underlying physical address space of the process, or continue to use them?
Thanks.