Quick introduction to reverse engineering for beginners

So, let’s download Linux Kernel 2.6.31, compile it in Ubuntu: make vmlinux, open it in IDA 5, find the
do_filp_open() function. At the beginning, we will see (comments are mine):
do_filp_open proc near
...
push ebp
mov ebp, esp
push edi
push esi
push ebx
mov ebx, ecx
add ebx, 1
sub esp, 98h
mov esi, [ebp+arg_4] ; acc_mode (5th arg)
test bl, 3
mov [ebp+var_80], eax ; dfd (1th arg)
mov [ebp+var_7C], edx ; pathname (2th arg)
mov [ebp+var_78], ecx ; open_flag (3th arg)
jnz short loc_C01EF684
mov ebx, ecx ; ebx