Subject: Re: Behavior of calling System V shared memory functions if not in kernel
To: Greg Earle <earle@isolar.tujunga.CA.US>
From: Chris G Demetriou <Chris_G_Demetriou@LAGAVULIN.PDL.CS.CMU.EDU>
List: current-users
Date: 12/02/1994 21:57:07
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>In 1.0, if one calls, e.g., "shmget()" et al. without having a kernel that was
>built with "options SYSVSHM", the program is delivered a SIGSYS (Bad system
>call) and it usually core dumps.

yup.  the function also returns EINVAL.  

It would seem that 'EINVAL' is returned, because if the system call
isn't implemented, it's really an 'invalid argument to a system call'.
To me, this makes sense if the system call number never has had a
syscall behind it (or if the syscall number is being 'reclaimed'),
but for 'optional' syscalls, i'm not sure it's the best way to
handle things.  i'm going to think about it for a little bit...