Tag: x86

  • LEA instruction

    The lea instruction places the address specified by its second operand into the register specified by its first operand. Note, the contents ofthe memory location are not loaded, only the effective address is computed and placed into the register. This is useful for obtaining a pointer into a memory region. source: http://www.cs.virginia.edu/~evans/cs216/guides/x86.html

  • exclusive OR Instruction :-

    GDB shows XOR Instruction (gdb) disassemble 0x00007f16db50b647 Dump of assembler code for function gtk_main: 0x00007f16db50b5a0 : push %r15 0x00007f16db50b5a2 : xor %edi,%edi 0x00007f16db50b5a4 : mov $0x1,%esi 0x00007f16db50b5a9 : push %r14 0x00007f16db50b5ab : push %r13 0x00007f16db50b5ad : push %r12 0x00007f16db50b5af : push %rbp 0x00007f16db50b5b0 : push %rbx 0x00007f16db50b5b1 : sub $0x38,%rsp 0x00007f16db50b5b5 : addl $0x1,0x4e2af4(%rip) #…

  • SUB – Subtract

    | SUB instruction | (gdb) disass Dump of assembler code for function *__GI___poll: 0x00007fc50ab670b0 : sub $0x28,%rsp 0x00007fc50ab670b4 : mov 0x29c52e(%rip),%eax # 0x7fc50ae035e8 0x00007fc50ab670ba : test %eax,%eax 0x00007fc50ab670bc : jne 0x7fc50ab670d5 0x00007fc50ab670be : movslq %edx,%rdx 0x00007fc50ab670c1 : mov $0x7,%eax 0x00007fc50ab670c6 : syscall => 0x00007fc50ab670c8 : cmp $0xfffffffffffff000,%rax 0x00007fc50ab670ce : ja 0x7fc50ab67121 0x00007fc50ab670d0 : add $0x28,%rsp…