System Call and Shared Memory

Question

Is SYSTEM CALLS needed to setup the shared memory between two processes ? and what are these system calls and does this system calls have any security concern?

Comments

Yes! I think system calls are needed because let suppose process B has occupied some memory segment and now a new Process A also using some same data that B is working on so , it's better than B share its that memory segment with A , now for this process A need the help of kernel , and for this system call is needed to invoke kernel.

Answer 1

Source: https://www.cs.cornell.edu/courses/cs4410/2008fa/homework/hw1_soln.pdf

Note: Here the question asks about “setting up” the shared memory space. For access, I think, we don’t need system calls and use methods like Peterson solution.