Understanding how the EIP works in x86 32-bit processor

• Extended Instruction Pointer (EIP)
• Pre-requisite installations
• Exercises
  • Files for exercise

Extended Instruction Pointer (EIP)

EIP is a register inside the x86 32-bit processor that points to the next instruction to be executed. The EIP changes after execution of every instruction and it is 32-bit in size.

Pre-requisite installations

PEDA extention for gdb can be installed using the following steps:

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git clone https://github.com/longld/peda.git ~/peda
echo "source ~/peda/peda.py" >> ~/.gdbinit

Exercises

Files for exercise

eipdemo.c

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#include <stdio.h>

int add(int a, int b)
{
    int sum = 0;
    sum = a+b;
    return sum;
}

int main(int argc, char const *argv[])
{
    int result = 0;

    result = add(10,20);

    printf("Addition: %d\n", result);
    
    return 0;
}