This assignment has two parts. It is due by 4/12/19 at 11:59PM.
There will be a late penalty of 5% per day late!
There is an assembly file called main.s in this folder, which is an excerpt from a compiled C program. Using what you've learned about x86-64 assembly, translate the code into an equivalent C program. Remember to take note for x86-64 calling conventions, specifically the order for a function's arguments and which registers correspond to said arguments.
One caveat not mentioned in lecture is that functions that take in variadic
arguments (e.g. printf) require one to note how many vector registers are used
(e.g. xmm0, xmm1, etc) into rax. Typically these are only used for passing
floating point arguments to a function. In our case, if a call to printf
doesn't use any floating point numbers, we can just load 0 into rax.
The name of the game is static analysis, where you analyze a binary by reading off of the assembly. We don't really want you to try and assemble and run the binary to analyze it's behavior just yet, as we'll save dynamic analysis for next week.
In a sentence or two, state what the program achieves. Don't say that the program executes X or Y instructions and prints stuff, but rather say what these instructions achieve.
Make sure to submit all of the code you write!
For Part 1, full points will be granted for C programs that compile and run on a Kali Linux environment. Partial credit will be granted if the program conveys the gist of assembly.
For Part 2, full points will be granted for correctly stating what the program achieves. No partial credit will be granted.
Look at the Binaries I slides for guidance.
If there's an assembly instruction that wasn't covered in the lecture slides, don't worry! There's way too many instructions that can be run on Intel CPUs to fit in a lecture, many of which aren't used that often. You can look up what an instruction does here. Posting on Piazza for help is fine too!