How is dynamic linker linked when executable using shared library is loaded?

I'm reading about the process of dynamic linking currently, and I read that the dynamic linker is also a shared library(ld.linux.so). Then how is ld.linux.so linked?

Is it linked in a static way?

> Is it linked in a static way?

Yes. It's a shared library which itself has no dependencies on other libraries (and can't have any, since there is nothing that would resolve such dependencies) -- it must be entirely self-contained.

In particular, ld.so contains its own copies of many libc routines (malloc, mmap, strcpy, etc.). You can see them with nm /lib64/ld-linux-x86-64.so.2 (if your distribution doesn't strip symbols from ld-linux).

Further, this special shared library is mmaped by the kernel at random address, and it must relocate itself when it starts (since again, there is nothing else that would perform such relocation).

This self-relocation could be rather involved on platforms which don't allow PC-relative data addressing.

When the kernel loads an excecutable, it looks for the .interp section of the ELF file; short for interpreter. For dynamically linked executables this will be set to 'ld-linux' by the static linker during build time. During runtime, the kernel loads this interpreter which handles the linking of other libraries.

You can see this using readelf -p .interp <executable>. For example, on my system running readelf -p .interp /bin/ls outputs

String dump of section '.interp':
  [     0]  /lib64/ld-linux-x86-64.so.2

See also the manual for ld-linux.