readelf与objdump：为什么两者都需要？

Question

我需要学习有关ELF文件布局的知识，因为我正在开展一个项目。我注意到这些工具的存在。 为什么所有Linux发行版都包括readelf和objdump？这些工具互补吗？在什么情况下我更倾向于使用其中之一？

- zr.

Answer 1

来自binutils/readelf.c：

 /* The difference between readelf and objdump:

   Both programs are capabale of displaying the contents of ELF format files,
   so why does the binutils project have two file dumpers ?

   The reason is that objdump sees an ELF file through a BFD filter of the
   world; if BFD has a bug where, say, it disagrees about a machine constant
   in e_flags, then the odds are good that it will remain internally
   consistent.  The linker sees it the BFD way, objdump sees it the BFD way,
   GAS sees it the BFD way.  There was need for a tool to go find out what
   the file actually says.

   This is why the readelf program does not link against the BFD library - it
   exists as an independent program to help verify the correct working of BFD.

   There is also the case that readelf can provide more information about an
   ELF file than is provided by objdump.  In particular it can display DWARF
   debugging information which (at the moment) objdump cannot.  */

- synthesizerpatel

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关于 objdump 无法转储 DWARF 调试信息的评论曾经是正确的，但自从大约2005年以来就不再正确了。 - Employed Russian

我也想补充一点，即 readelf 是与架构无关的。要正确地使用 objdump 对您的应用程序进行反汇编，您需要使用来自相关工具链的适当 objdump，例如 ARM 二进制文件需要 ARM objdump，X86 二进制文件需要 X86 objdump，以此类推。 - Piotr Zierhoffer

elfutils工具链现在提供了良好的elf/dwarf一致性检查，因此仅出于这个原因维护binutils elfutils可能并不必要。 - fche

readelf比objdump更好吗？因为它提供了更多的信息？ - Tumb1eweed