As you've probably guessed, not every error can happen to every system call.
If you start with
/usr/include/errno.h, you can probably track down the manifest constants like "EPERM" or "EINTR". I found them in:
but it looks to me like there could be some variation by distro or version of libc.
Linux seems to be really good at having the errors that any given system call can manifest in the man page for that system call:
man 2 read or
man 2 socket for example. This hasn't traditionally been true for the various Unix versions that are probably still out there. I don't have access to a *BSD system to check this for modern Unixes.