My relevant GDB cheatsheet

set disassembly-flavor intel

disas main

break *main

break *(address)

continue -> continues execution after the breakpoint

run

stepi ->run the next instruction

x/i $pc -> x is for examine. i is for instruction. $pc means program counter. So the command means examine the instruction at current program counter

set disassemble-next-line on

stepi

It will do that automatically. Keep hitting enter and it will step through the program!

info registers ->Print registers at the current registers

p $rdi -> p will print a particular register specified by $sign. here, rdi. THis would be in decimal

p/x $rdi -> prints rdi in hex

Now let's say your program hits a function call. Using stepi will step into the function and take you step by step through the function code. SOmetimes this is what we want!

Sometimes, we don't care about what a function is doing. So, we use nexti

nexti -> When a function is hit, and nexti is entered, rather than going to the next instruction CPU executes, it goes to the one right after this function call in main

ARM CPUs like Mac M1, M2

Use

ROSETTA_DEBUGSERVER_PORT=1234 ./binary

Then a new terminal:

gdb-multiarch

set architecture i386:x86-64

target remote localhost:1234

Entry Point

Often, main is not the entry point. Sometimes it can be "_start" as well. Using info files, one can find the entry point.

info files