A flaw in the protection system of many operating systems is argument passing. Often, a common shared stack is used by all nested routines for arguments as well as for the remainder of the context of each calling process. (a) Explain what vulnerabilities this flaw presents. (b) Explain how the flaw can be controlled. The shared stack is still to be used for passing arguments and storing context
What will be an ideal response?
One
difficulty
is
that
any
routine
can
be
faulty:
routine
A
puts
an
incorrect
value
on
the
stack
and
B
retrieves
it,
not
knowing
it
is
faulty.
Routine
B
can
be
self-?defensive,
checking
the
reasonableness
of
the
value.
Obviously,
without
duplicating
the
work
of
A,
B
cannot
determine
whether
the
value
is
exactly
right.
A
second
difficulty
is
stack
depth:
any
routine
can
use
the
entire
stack.
A
third
difficulty
is
that
any
routine
can
modify
results
of
any
other
routine:
routine
A
puts
a
value
on
the
stack,
and
routine
B
subsequently
changes
that
value
to
anything.
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This is the type of variable that the Loop instruction uses internally.
a. Register b. Counter c. Matrix d. Address e. None of these
What are some reasons for using friend operator overloading?
What will be an ideal response?
Match each term with the correct statement below.
A. converted a computer's digital signal to an analog signal that was amplified by a transceiver and broadcast through an antenna. B. promotes wireless networking for LANs C. spreads a transmission over one or more adjoining frequencies, using greater bandwidth to transmit the signal. D. device that can optionally attach to a cabled network and that services wireless communications between WNICs and the cabled network. E. characteristic in 802.11 standard that helps wireless devices take interference into account. F. defined by 802.1x to allow only authenticated communications. G. means that transmissions hop among 79 frequencies for each packet that is sent. H. communication method used by the IEEE 802.11R standard. I. transmits the signal between three antennas, one of which is on a satellite in space.
Which of the following is NOT true of natural language?
a. It can result in unstructured algorithms. b. It can make algorithms hard to follow. c. It can cause algorithms to be rambling. d. It is well-suited for algorithm design.