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()?
Describe what is actual arguments? - When certain functions are created and used to perform an action on some provided values, some values are required to be passed to them. Th
If we take the input image and smooth it with a Gaussian of a significant size before computing the Canny edges does the number of edges change, and do the locations of these edges
# include stdio.h> # include string.h> # include conio.h> void main() { int i=0,j=0,b=0,count=0; int a[100]; for(i=0;i
#questio A charitable organization wants to design a special ATM machine to be used by needy people. The association supplies the needy person with a pin number to be able to use
Aim: Write a program of multipication using inline function class Multiply { int x,y; public: void getdata(); inline calc
C++ Help
You are given a collection of words, say as in a dictionary. You can represent it in the following compressed form: the first word will be followed by a sequence of a pair of numbe
Write a function that has four unsigned char parameters, combines the four one-byte integer values into an unsigned integer, and returns the unsigned integer. When the four one
Where are longjmp and setjmp used in C++? -Setjmp and longjmp must not be used in C++. - Longjmp jumps out of the function without unwinding stack. This means that local obj
I want MODI method''s coding in c++ using all concepts of c++..please help me its my project work...
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