Questions tagged [amd64]

A family of instruction set architectures originally designed by AMD to extend the Intel x86 instruction set to 64bits CPUs.

Filter by
Sorted by
Tagged with
62
votes
3answers
96k views

How are the segment registers (fs, gs, cs, ss, ds, es) used in Linux?

I try to understand the process of memory segmentation for the i386 and amd64 architectures on Linux. It seems that this is heavily related to the segment registers %fs, %gs, %cs, %ss, %ds, %es. Can ...
83
votes
2answers
63k views

What is PLT/GOT?

From time to time, when disassembling x86 binaries, I stumble on reference to PLT and GOT, especially when calling procedures from a dynamic library. For example, when running a program in gdb: (gdb)...
24
votes
4answers
24k views

What is the meaning of movabs in gas/x86 AT&T syntax?

I just found a strange instruction by assembling (with gas) and disassembling (with objdump) on a amd64 architecture. The original amd64 assembly code is: mov 0x89abcdef, %al And, after gas ...
4
votes
1answer
1k views

x86-64 bit Buffer Overflow, help with overwriting %rip

I am trying to get a buffer overflow exploit to work on Ubuntu 16.04 LTS 64bit. To this end I use the following vulnerable program: #include <stdio.h> #include <string.h> #include <...
3
votes
2answers
7k views

When was the MOVABS instruction introduced?

When trying to write an instruction set analysis tool for disassembled code (https://superuser.com/a/832440/384221) I have found opcode MOVABS which was not included in my opcode source database (...