Comment by gmueckl

OK, I spent a few additional minutes digging into this. It's been too long since I looked at those mechanisms. Turns out my brain was stuck in pre-PIE world.

Global variables in PIC shared libraries are really weird: the shared library's variable is placed into the main program image data segment and the relocation is happening in the shared library, which means that there is an indirection generated in the library's machine code.