您正在分解64位代码，就好像它是32位代码一样.除非您专门重写了反汇编程序或使用objcopy或其他方法将64位机器代码复制到32位ELF目标文件中，否则通常无法实现.

You're disassembling 64-bit code as if it were 32-bit code. This is not normally possible unless you specifically override your disassembler or use objcopy or something to copy 64-bit machine-code into a 32-bit ELF object file.

x86-64将0x40..f字节重新用作REX前缀，而不是inc/dec的1字节编码. DEC EAX实际上是REX.W前缀，因此对于正常的帧指针设置，该指令为mov %rsp, %rbp.

x86-64 repurposed the 0x40..f bytes as REX prefixes instead of 1 byte encodings of inc/dec. The DEC EAX is actually a REX.W prefix, so the instruction is mov %rsp, %rbp for the normal frame-pointer setup.

这也说明了堆栈指针下方红色区域的前8个字节的使用. (x86-64 System V有一个红色区域，i386 System V没有红色区域；在存储在它下面之前，它会移动ESP.)并且它解释了指针的-8而不是-4，因为x86-64具有8字节指针.

This also explains the use of the top 8 bytes of the red-zone below the stack pointer. (x86-64 System V has a red-zone, i386 System V doesn't; it would move ESP before storing below it.) And it explains -8 instead of -4 for the pointer, because x86-64 has 8-byte pointers.

0字节是因为您要拆装未链接的.o.链接器将使用字符串的绝对地址填充这四个字节的零.

The 0 bytes are because you're disassembling a .o that isn't linked. Those 4 bytes of zeros will be filled in with the string's absolute address by the linker.

GCC在这里使用mov r/m64, sign_extended_imm32使用32位绝对地址作为立即数来存储指向内存的8字节指针.

GCC is using a mov r/m64, sign_extended_imm32 here to store an 8-byte pointer to memory using a 32-bit absolute address as an immediate.

将其放入寄存器中，我们将为非PIE可执行文件获得常规的mov r32, imm32(隐式零扩展至64位).但是此代码(使用默认的-O0调试模式")需要内存中的整个8字节指针.它仍然可以使用32位绝对地址而不是相对RIP的LEA到寄存器+单独的存储区中，但是必须将其显式符号扩展为64位.

To put it in a register, we'd get the normal mov r32, imm32 (with implicit zero extension to 64-bit) for a non-PIE executable. But this code (with the default -O0 "debug mode") needs the whole 8-byte pointer in memory. It can still use a 32-bit absolute address instead of a RIP-relative LEA into a register + separate store, but it has to be explicit sign-extension to 64-bit.