Question

Suppose a user wants to do a system call. Assume that the service routine of this system call is at physical address 500., instead of executing a system call, the user simply jumps to this location 500.

Assume that logical and physical addresses are the same and no memory protection is in place, i.e., cpu does not check that this address 500 is beyond the user’s memory space.

Will something go wrong while the service routine executes?

Answer 1

Dear Student i understood the problem and can interpret as given below.To thoroughly understand the answer to this solution you must first know the difference between logical and physical addressing.Please go through the information given below.

Logical Address is produced by CPU while a program is running. The intelligent location is virtual location as it doesn't exist genuinely, in this way, it is otherwise called Virtual Address. This location is utilized as a kind of perspective to get to the physical memory area by CPU. The term Logical Address Space is utilized for the arrangement of all consistent locations produced by a program's viewpoint.

The equipment gadget called Memory-Management Unit is utilized for planning sensible location to its relating physical location.

Physical Address recognizes a physical area of required information in a memory. The client never legitimately manages the physical address however can access by its relating consistent location. The client program creates the intelligent location and imagines that the program is running in this legitimate location yet the program needs physical memory for its execution, accordingly, the sensible location must be planned to the physical location by MMU before they are utilized. The term Physical Address Space is utilized for all physical delivers relating to the legitimate locations in a Logical location space.

MMU plot

Planning virtual-address to physical-addresses

Contrasts Between Logical and Physical Address in Operating System

The essential contrast among Logical and physical location is that Logical location is produced by CPU in context of a program though the physical location is an area that exists in the memory unit.

Intelligent Address Space is the arrangement of all legitimate locations created by CPU for a program though the arrangement of all physical location planned to relating coherent locations is called Physical Address Space.

The coherent location doesn't exist genuinely in the memory though physical location is an area in the memory that can be gotten to truly.

Indistinguishable coherent locations are created by Compile-time and Load time address restricting strategies while they contrasts from one another in run-time address restricting strategy. If you don't mind allude this for subtleties.

The consistent location is produced by the CPU while the program is running though the physical location is figured by the Memory Management Unit (MMU).\

Dear Student by now I assume you would have gone thoroughly gone through the above information and would have interpreted easily with the following question.Hope all your questions have been answered if not feel free to ask any of the doubts in comment section and if you have liked the above information please do upvote.Thanks a ton!