others have pointed out a few things that are wrong with your code. I would like to add that you would not add 20 bits to the current breakpoint (or 20 bytes like add rbx, 20 actually does), you would simply add 5 bytes. Also, your first syscall argument will not be in rbx, it … Read more
In the diagram you posted, the “break”—the address manipulated by brk and sbrk—is the dotted line at the top of the heap. The documentation you’ve read describes this as the end of the “data segment” because in traditional (pre-shared-libraries, pre-mmap) Unix the data segment was continuous with the heap; before program start, the kernel would … Read more