ENSF 461 STUDY SHEET 2026 TEST PAPER
QUESTIONS AND SOLUTIONS
GUARANTEED TO PASS
●● physical address.
Answer: Base of the physical address + virtual address
The "real" address location.
Comprised of: physical page number + offset
physical page number is translated from virtual address.
●● Virtual Address.
Answer: Memory addresses used in virtualized memory. An abstraction
of physical memory.
Made up of the VPN + offset (in binary)
●● Implicitly managed memory.
Answer: Memory that doesn't have to be explicitly allocate or
deallocate.
,●● stack.
Answer: Holds function calls, function arguments, and local variables.
Can grow or shrink during execution
Is implicitly managed (aka automatic memory)
An example of a bump allocator, allocations are really fast since we only
add or subtract from the stack pointer.
Cons: can only allocate and deallocate memory in reverse order of which
they were allocated
●● heap.
Answer: dynamically allocated, fine-grain user managed memory
●● text.
Answer: Where the instructions of the program are stored
●● Buffer Overflow.
Answer: trying to access memory outside of the allocated area
●● Malloc(x).
, Answer: allocates memory of x number of bytes and returns a void
pointer to those bytes.
●● 3 Main Memory Management Goals.
Answer: 1. Transparency — OS should implement memory in a way that
is invisible to the process
2. Efficiency — Structures in place to virtualize memory shouldn't take
up too much space and shouldn't slow down programs.
3. Protection — OS should protect each processes memory, a process
shouldn't be able to change the memory of another process.
P.E.T
●● Memory Map.
Answer: A representation of how the memory is organized and allocated
●● Address space randomization (ASLR).
Answer: A technique used by the OS to increase memory security by
randomly arranging key parts of programs address space.
(Split up the memory addresses so that it is harder to access)
QUESTIONS AND SOLUTIONS
GUARANTEED TO PASS
●● physical address.
Answer: Base of the physical address + virtual address
The "real" address location.
Comprised of: physical page number + offset
physical page number is translated from virtual address.
●● Virtual Address.
Answer: Memory addresses used in virtualized memory. An abstraction
of physical memory.
Made up of the VPN + offset (in binary)
●● Implicitly managed memory.
Answer: Memory that doesn't have to be explicitly allocate or
deallocate.
,●● stack.
Answer: Holds function calls, function arguments, and local variables.
Can grow or shrink during execution
Is implicitly managed (aka automatic memory)
An example of a bump allocator, allocations are really fast since we only
add or subtract from the stack pointer.
Cons: can only allocate and deallocate memory in reverse order of which
they were allocated
●● heap.
Answer: dynamically allocated, fine-grain user managed memory
●● text.
Answer: Where the instructions of the program are stored
●● Buffer Overflow.
Answer: trying to access memory outside of the allocated area
●● Malloc(x).
, Answer: allocates memory of x number of bytes and returns a void
pointer to those bytes.
●● 3 Main Memory Management Goals.
Answer: 1. Transparency — OS should implement memory in a way that
is invisible to the process
2. Efficiency — Structures in place to virtualize memory shouldn't take
up too much space and shouldn't slow down programs.
3. Protection — OS should protect each processes memory, a process
shouldn't be able to change the memory of another process.
P.E.T
●● Memory Map.
Answer: A representation of how the memory is organized and allocated
●● Address space randomization (ASLR).
Answer: A technique used by the OS to increase memory security by
randomly arranging key parts of programs address space.
(Split up the memory addresses so that it is harder to access)
