In general, GPLv2+ is used by programs, LGPLv2+ is used for
libraries.

LGPLv2+ with exceptions is used for things that are linked directly
into dynamically linked programs and shared libraries (e.g. crt
files, lib*_nonshared.a).  Historically, this exception also applies
to parts of libio.

GPLv2+ with exceptions is used for parts of the Arm unwinder.

GFDL is used for the documentation.

Some other licenses are used in various places (BSD, Inner-Net,
ISC, Public Domain).

HSRL and FSFAP are only used in test cases, which currently do not
ship in binary RPMs, so they are not listed here.  MIT is used for
scripts/install-sh, which does not ship, either.

GPLv3+ is used by manual/texinfo.tex, which we do not use.

LGPLv3+ is used by some Hurd code, which we do not build.

LGPLv2 is used in one place (time/timespec_get.c, by mistake), but
it is not actually compiled, so it does not matter for libraries.