Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Each function has its own stack frame between %fp and %sp. Let Caller calls Callee. Then Caller's %sp becomes callee's %fp, and callee's %sp set to be a new value (a smaller one because stack grows from large address to small address). You can think that Callee's stack frame is on top of Caller's stack frame.
In Caller: put arguments in %o0 to %o5 registers or if number of arguments more than 6, prepare values in call linkage of the current stack frame. Then "call" address_of_callee; %o7 stored the returned address. (This %o7 will becomes %i7 in callee after the callee executes save instruction.)
In Callee: it executes "save" instruction:
So at this point in callee, %i6 (%fp was caller's %o6) is set, and %o6 (%sp is set to be a new value). Question: where is the old %fp? It is stored somewhere in the top portion of the previous stack frame (see step 0.) The return address of Callee is stored in %i7. Is it possible to write a program to overflow this %i7? What return address that you really can overflow? Question: how to access that return address.
The "restore" instruction is the inverse function of save. Then the "ret" instruction should branch to %i7+8. The normal address should be %i7+4 as the next instruction address after call. The extra 4 is because sparc has a "branch delay" instruction that is executed BEFORE the call is made even it is put just after CALL. Is it strange. Not really. This is because modern CPU is a pipeline machine. It loads instruction every clock cycle, and branch (or jump or call) somewhat cannot be really done until the later stage the pipeline. And then it is already too late because the one JUST after this branch has already been executed. If you want to know more, you should take a look at computer architecture textbook which I think every graduate should know.
You should be very clear what return address in server.c is overflowed? Is it the return address of main() or the return address of copy()?
Write a function that calculates the number of elapsed days between two dates. For example the days between Feb 3, 1970 and June 21, 1980? Becareful for the Leap year
Multidimensional Arrays - Every dimension is specified in separate brackets e.g. int arr[4][3]; This is a two-dimensional array with 4 as row dimension and 3 as
What are all of the implicit member functions of the class? Or what are all of the functions that compiler implements for us if we don't describe one? A: 1. copy ctor
Using the Constructor There are basically three ways of creating and initializing the object. The first way to call the constructor is explicitly as :
Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b
Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b
Create an array of Strings and fill it with some interesting text, such as vacation destinations, album names, or weapon names from a CRPG. Display three elements of the array on t
find the minimum shelf
Overall Program Objective: You will design and simulate a basic RISC processor. You will create and encode an instruction set. Your final task will be to "compile" a program
Write a C++ program that reads from keyboard 3 integers, with proper input prompt, and then displays the maximum sum of any pair of numbers from these three. If the 3 numbers are 5
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd