title: Can I modify the dynamic linker and use without recompiling the glibc?
body: <p>I am trying to modify the dynamic linker provided in the libc6(2.15-0ubuntu20.2) on a 64 bit Ubuntu machine.</p>
  
  <p>So currently my code is using the same version of the glibc library. (I have downloaded the source code for the same and working on it). My question is that is it possible to modify and build <strong>only</strong> the linker source code which is present in <code>glibc\elf\</code> directory without building the entire glibc library.</p>
  
  <p>And if it is possible how can I make my test program to switch using the new version of dynamic linker that I have build myself instead of using the default unmodified linker.</p>
  
  <p>Any pointers or suggestions are highly appreciated.
  (If any more information is needed please let me know)</p>
  
  <p><strong>EDIT::</strong>
  @constantius</p>
  
  <p>I followed the steps in the post linked by you to build ld.so.
  But I am getting following error on the make and I checked ld.so is not there in the elf.
  The error is::</p>
  
  <pre><code>/var/services/homes/abhi/test/ld/eglibc-build/elf/librtld.os: In function `generic_getcwd':
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:356: undefined reference to `__closedir'
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:368: undefined reference to `__fdopendir'
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:384: undefined reference to `__readdir'
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:397: undefined reference to `rewinddir'
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:528: undefined reference to `__closedir'
  /var/services/homes/abhi/test/ld/eglibc-2.15/elf/../sysdeps/posix/getcwd.c:490: undefined reference to `__closedir'
  collect2: error: ld returned 1 exit status
  make[2]: *** [/var/services/homes/abhi/test/ld/eglibc-build/elf/ld.so] Error 1
  make[2]: Leaving directory `/var/services/homes/abhi/test/ld/eglibc-2.15/elf'
  make[1]: *** [elf/subdir_lib] Error 2
  make[1]: Leaving directory `/var/services/homes/abhi/test/ld/eglibc-2.15'
  make: *** [all] Error 2
  </code></pre>
  
  <p><strong>NOTE</strong> With the same infrastructure I can build and install the full GLIBC so I dont think there is an error with the infrastructure.
  -- I guess the error is some where related to editing Makeconfig to all-subdirs = csu elf gmon io misc posix setjmp signal stdlib string time. 
  --Any suggestions on this..</p>
  
  <p><strong>SOLVED</strong>
  Need to add dirent in the all-subdirs list in addition to what we edited before</p>
  
  <p>Thanks</p>