Delete the existing segment structs for user segments (not kernel segments)
Create new segment structs for the text, data, bss, and stack segments of the new program - private, copy-on-write.
text and data are mapped to the corresponding parts of the executable file.
the bss, stack, and heap segments are demand-zero and are mapped to anonymous files. The bss size is given in the executable file, but the stack and heap segments are initially size 0.
C libraries etc. used by the executable are mapped as shared objects into a shared object segment in the virtual address space.

execvp