(gdb) disas main
Dump of assembler code for function main:
0x0000000000401106 <+0>: endbr64
0x000000000040110a <+4>: push %rbp
0x000000000040110b <+5>: mov %rsp,%rbp
0x000000000040110e <+8>: mov %edi,-0x14(%rbp)
0x0000000000401111 <+11>: mov %rsi,-0x20(%rbp)
0x0000000000401115 <+15>: movl $0x1e0da,-0x4(%rbp)
0x000000000040111c <+22>: movl $0x25f,-0xc(%rbp)
0x0000000000401123 <+29>: movl $0x0,-0x8(%rbp)
0x000000000040112a <+36>: jmp 0x401136 <main+48>
0x000000000040112c <+38>: mov -0x8(%rbp),%eax
0x000000000040112f <+41>: add %eax,-0x4(%rbp)
0x0000000000401132 <+44>: addl $0x1,-0x8(%rbp)
0x0000000000401136 <+48>: mov -0x8(%rbp),%eax
0x0000000000401139 <+51>: cmp -0xc(%rbp),%eax
0x000000000040113c <+54>: jl 0x40112c <main+38>
0x000000000040113e <+56>: mov -0x4(%rbp),%eax
0x0000000000401141 <+59>: pop %rbp
0x0000000000401142 <+60>: ret
To get the flag:
-I put a breakpoint at the end of the main function
-I started the program
(gdb) run
Starting program: /home/cheepsss/Downloads/debugger0_b
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
-I checked the registers
(gdb) info registers
rax 0x4af4b 307019
rbx 0x0 0
rcx 0x401150 4198736
rdx 0x7fffffffdf58 140737488346968
rsi 0x7fffffffdf48 140737488346952
rdi 0x1 1
rbp 0x7fffffffde30 0x7fffffffde30
rsp 0x7fffffffde30 0x7fffffffde30
r8 0x7ffff7e1bf10 140737352154896