MFC 325835: Use #if instead of #ifdef for __BSD_VISIBLE tests.

__BSD_VISIBLE is always defined and it's value instead needs to be
tested via #if to determine if FreeBSD-specific APIs should be
exposed.

PR: 196226

MFC r298931, r298981, r299375:

Minor spelling fixes in:
sys/dev, sys/sys

Many of these have user-visible strings.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add ucred pointer to the SysV-related memory structures. This is required
for racct.

Note that after this commit, ipcs(1) needs to be rebuilt. Otherwise, it will
fail with "ipcs: sysctlbyname: kern.ipc.msqids: Cannot allocate memory".

Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)

Change the ABI of some of the structures used by the SYSV IPC API:
- The uid/cuid members of struct ipc_perm are now uid_t instead of unsigned
short.
- The gid/cgid members of struct ipc_perm are now gid_t instead of unsigned
short.
- The mode member of struct ipc_perm is now mode_t instead of unsigned short
(this is merely a style bug).
- The rather dubious padding fields for ABI compat with SV/I386 have been
removed from struct msqid_ds and struct semid_ds.
- The shm_segsz member of struct shmid_ds is now a size_t instead of an
int. This removes the need for the shm_bsegsz member in struct
shmid_kernel and should allow for complete support of SYSV SHM regions
>= 2GB.
- The shm_nattch member of struct shmid_ds is now an int instead of a
short.
- The shm_internal member of struct shmid_ds is now gone. The internal
VM object pointer for SHM regions has been moved into struct
shmid_kernel.
- The existing __semctl(), msgctl(), and shmctl() system call entries are
now marked COMPAT7 and new versions of those system calls which support
the new ABI are now present.
- The new system calls are assigned to the FBSD-1.1 version in libc. The
FBSD-1.0 symbols in libc now refer to the old COMPAT7 system calls.
- A simplistic framework for tagging system calls with compatibility
symbol versions has been added to libc. Version tags are added to
system calls by adding an appropriate __sym_compat() entry to
src/lib/libc/incldue/compat.h. [1]

PR: kern/16195 kern/113218 bin/129855
Reviewed by: arch@, rwatson
Discussed with: kan, kib [1]

Namespace: semsys() and shmsys() aren't standard.

Correct types of variables used to track amount of allocated SysV shared
memory from int to size_t. Implement a workaround for current ABI not
allowing to properly save size for and report more then 2Gb sized segment
of shared memory.

This makes it possible to use > 2 Gb shared memory segments on 64bit
architectures. Please note the new BUGS section in shmctl(2) and
UPDATING note for limitations of this temporal solution.

Reviewed by: csjp
Tested by: Nikolay Dzham <i levsha org ua>
MFC after: 2 weeks

Make sure we restrict Linux only IPC calls from being executed
through the FreeBSD ABI. IPC_INFO, SHM_INFO, SHM_STAT were added
specifically for Linux binary support. They are not documented
as being a part of the FreeBSD ABI, also, the structures necessary
for them have been hidden away from the users for a long time.

Also, the Linux ABI layer uses it's own structures to populate the
responses back to the user to ensure that the ABI is consistent.

I think there is a bit more separation work that needs to happen.

Reviewed by: jhb
Discussed with: jhb
Discussed on: freebsd-arch@ (very briefly)
MFC after: 1 month

Change the data type of the upper shared memory limits from a signed
integer to an unsigned long. This lifts variables like the maximum
number of pages available for shared memory from 2^31 to 2^32 on 32
bit architectures, and from 2^31 to 2^64 on 64 bit architectures.

It should be noted that this changes breaks ABI on 64 bit architectures
because the size of the shmmax, shmmin, shmmni, shmseg and shmall members
of the shminfo structure has changed.

Silence on: current@

This header is supposed to declare pid_t, size_t, and time_t.

/* -> /*- for license, minor formatting changes

In the kernel-only portionss of System V IPC objects (messages,
message queues, shared memory segments, and semaphores), add a struct
label pointer, which will hold the MAC labels for the objects. As a
result of recent work to separate kernel and user space ABIs, this
should not break the ABI for applications using System V IPC, but will
require a rebuild of the ipcs monitoring tool.

Submitted by: Dandekar Hrishikesh <rishi_dandekar at sbcglobal dot net>
Obtained from: TrustedBSD Project
Sponsored by: DARPA, SPAWAR, McAfee Research

First of several commits to allow kernel System V IPC data structures
to be modified and extended without breaking the user space ABI:

Define _kernel wrapper data structures for the user-exposed data
structures that current server as the internal data structures for
the implementation:

- struct msqid_kernel wraps struct msqid_ds.
- struct semid_kernel wraps truct semid_ds.
- struct shmid_kernel wraps struct shmid_ds.
- Don't expose extern definition 'shmsegs' outside of sysv_shm.c.

Submitted by: Dandekar Hrishikesh <rishi_dandekar at sbcglobal dot net>
Obtained from: TrustedBSD Project
Sponsored by: DARPA, SPAWAR, McAfee Research

Bring shm functions closer the the opengroup standards.

PR: 47469
Submitted by: Craig Rodrigues <rodrigc@attbi.com>

It is possible for an active aio to prevent shared memory from being
dereferenced when a process exits due to the vmspace ref-count being
bumped. Change shmexit() and shmexit_myhook() to take a vmspace instead
of a process and call it in vmspace_dofree(). This way if it is missed
in exit1()'s early-resource-free it will still be caught when the zombie is
reaped.

Also fix a potential race in shmexit_myhook() by NULLing out
vmspace->vm_shm prior to calling shm_delete_mapping() and free().

MFC after: 7 days

Remove __P

Introduce [IPC|SHM]_[INFO|STAT] to shmctl to make
`/compat/linux/usr/bin/ipcs -m` happy.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.

$Id$ -> $FreeBSD$

Forward declare more structs that are used in prototypes here - don't
depend on <sys/types.h> forward declaring common ones.

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

removed:
CLBYTES PD_SHIFT PGSHIFT NBPG PGOFSET CLSIZELOG2 CLSIZE pdei()
ptei() kvtopte() ptetov() ispt() ptetoav() &c &c
new:
NPDEPG

Major macro cleanup.

kern_descrip.c: add fdshare()/fdcopy()
kern_fork.c: add the tiny bit of code for rfork operation.
kern/sysv_*: shmfork() takes one less arg, it was never used.
sys/shm.h: drop "isvfork" arg from shmfork() prototype
sys/param.h: declare rfork args.. (this is where OpenBSD put it..)
sys/filedesc.h: protos for fdshare/fdcopy.
vm/vm_mmap.c: add minherit code, add rounding to mmap() type args where
it makes sense.
vm/*: drop unused isvfork arg.

Note: this rfork() implementation copies the address space mappings,
it does not connect the mappings together. ie: once the two processes
have split, the pages may be shared, but the address space is not. If one
does a mmap() etc, it does not appear in the other. This makes it not
useful for pthreads, but it is useful in it's own right for having
light-weight threads in a static shared address space.

Obtained from: Original by Ron Minnich, extended by OpenBSD

Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.

Fix several sysinit functions that had the wrong type and unnecessarily
external linkage.

Eliminate sloppy common-style declarations. There should be none left for
the LINT configuation.

Several constants have been missing in the SysV IPC header files that
are recommended by the literature.

Fixes PR# misc/575: constants in sys/sem.h...

Submitted by: daveho@infocom.com (Dave Hovemeyer)

Prototypes, prototypes and even more prototypes. Not quite done yet, but
getting closer all the time.

Got rid of compiler warnings.

Added SYSV ipcs.

Obtained from: NetBSD and FreeBSD-1.1.5