Re: BUG #5275: validate_exec in port/exec.c only reads u/g/o, not ACLs

"James Bellinger" <jfb@zer7.com> writes:
> I'm not certain of the actual *purpose* for this function even checking in
> the first place, but the result is that, if Postgres gets its access via an
> ACL, it will say 'invalid binary' here and there, will not be able to find
> its own executables, etc. I can see no purpose for this function.

Hmm.  I wonder why we have all that complexity at all, rather than using
access(2).  The man page says it checks against real not effective uid,
but since we don't run setuid I think there's no difference.

[ pokes in CVS history ... ]  Oh, this is interesting: this code looks
like this clear back to the original Berkeley import, and back then it
had this comment:

    * We use the effective uid here because the backend will not have
    * executed setuid() by the time it calls this routine.

So once upon a time there was a reason to try to implement access()
for ourselves, but it's long gone.  Comments?

            regards, tom lane