Question

What is the purpose of the system call stack? How does it support recursion?

Answer 1

System call:

The system call provides the service to the user and it is a way by which the computer program requests service from the kernel. The kernel manages the key component of the operating system like device management, file management, CPU scheduling, memory management, etc.

System call stack:

The system call stack is a stack data structure that is used to store the information of currently executing process or function or subroutines. This stack is also known as run time stack or execution stack or execution stack.

A stack is a linear data structure in which insertion and deletion operation performed at the top always.

The main use of system call stack is to store the details about the subroutines.

Yes, it support recursion.

When a function is called then the return address is pushed on to the stack.

The recursive function calls to itself and a terminate or base condition is specified which breaks the infinite execution of the recursive call. When the function call to itself then it works like a continue statement and the control goes to the starting of the function with updated argument value.

In recursion, when a function is called then the return address is pushed on to the top of the stack every time and this address is used to return from the function activation.

So, recursion is automatically supported by the system call stack.