sysv IPC and shminfo ABI [solved]

Christian S.J. Peron csjp at
Tue Feb 12 17:38:53 UTC 2008

After having some discussions with jhb, and reviewing the commit logs
that introduced IPC_INFO, this is a non-issue.  The whole reason this
was introduced was to satisfy Linux compatability. 

revision 1.67
date: 2001/10/28 09:29:07;  author: mr;  state: Exp;  lines: +45 -2
Introduce [IPC|SHM]_[INFO|STAT] to shmctl to make
`/compat/linux/usr/bin/ipcs -m` happy.

This was never an intented part of the FreeBSD ABI, which explains
why the structure is not made available to the user.  Although the size
has changed, it doesn't matter, because the Linux ABI layer will prepare
it's own shminfo structure as send it back out to the user.

So, I am going to make shmctl(IPC_INFO ...) for the FreeBSD ABI return
EINVAL, and I am going to add some serious comments around various points
in the kernel explaining why things are there, and how they should never
be exported.

Thanks everyone for the input.

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