Why are there global offset tables and procedure l

Question

I've done a bunch of reading on dynamic linker relocations and position independent code including procedure linkage tables and global offset tables. I don't understand why a statically linked executable needs a PLT and GOT. I compiled a hello world program on my ubuntu x86_64 machine and when I dump the section headers with readelf -S it shows PLT and GOT sections.

I also created a shared library with a simple increment function that I compiled with gcc -shared without -fpic and I also see PLT and GOT sections. I didn't expect this either.

Answer 1

I don't understand why a statically linked executable needs a PLT and GOT.

It doesn't.

I compiled a hello world program on my ubuntu x86_64 machine and when I dump the section headers with readelf -S it shows PLT and GOT sections.

This is an accident of implementation. The sections come from crt1.o, and there isn't a separate crt1s.o for fully-static linking, so you end up with .plt and .got entries from there.

You can strip these sections, and the binary will still work:

objcopy -R.got -R.plt a.out a.out2

Note: do not strip .rela.plt, as that section is still needed to implement IFUNCs.