On a related tangent, why is mmap() needed to begin with? Is it not an example of a leaky abstraction? I know, I know, how else would a process communicate its

On a related tangent, why is mmap() needed to begin with? Is it not an example of a leaky abstraction? I know, I know, how else would a process communicate its needs to the memory management system. I have seen shellcode that marks writeable pages executable using mmap, so it is certainly useful.