MFC r329525:

Correct/improve the descriptions if kern.ipc.(shmsegs,sema,msqids).

The description of kern.ipc.shmsegs was wrong since 2005. I updated the
others (which were more correct) to match.

PR: 225933
Reviewed by: cem
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14391

MFC r298584:

Note the existence of module-specific jail paramters, starting with the
linux.* parameters when linux emulation is loaded.

MFC r298585:

Encapsulate SYSV IPC objects in jails. Define per-module parameters
sysvmsg, sysvsem, and sysvshm, with the following bahavior:

inherit: allow full access to the IPC primitives. This is the same as
the current setup with allow.sysvipc is on. Jails and the base system
can see (and moduly) each other's objects, which is generally considered
a bad thing (though may be useful in some circumstances).

disable: all no access, same as the current setup with allow.sysvipc off.

new: A jail may see use the IPC objects that it has created. It also
gets its own IPC key namespace, so different jails may have their own
objects using the same key value. The parent jail (or base system) can
see the jail's IPC objects, but not its keys.

PR: 48471

MFC r282213:

Add kern.racct.enable tunable and RACCT_DISABLED config option.
The point of this is to be able to add RACCT (with RACCT_DISABLED)
to GENERIC, to avoid having to rebuild the kernel to use rctl(8).

MFC r282901:

Build GENERIC with RACCT/RCTL support by default. Note that it still
needs to be enabled by adding "kern.racct.enable=1" to /boot/loader.conf.

Note those two are MFC-ed together, because the latter one changes the
name of RACCT_DISABLED option to RACCT_DEFAULT_TO_DISABLED. Should have
committed the renaming separately...

Relnotes: yes
Sponsored by: The FreeBSD Foundation

MFC r282084:
Fix locking for oshmctl() and shmsys().

MFC r281094:
Restore proper error from oshmctl(2), broken by r280323.

MFC r281071:
Remove useless initialization.

MFC r280323:
Somewhat modernize the SysV shm code.

MFC r280325 (by cognet):
Fix warning for !MAC case.

MFC r278697 (by alc):
Preset the object's color, or alignment, to maximize superpage usage.

MFC r258056 (by alc):
Eliminate the gratuitous use of mmap(2) flags from the implementation
of kern_shmat(). Use a simpler approach to determine whether to pass
VMFS_NO_SPACE or VMFS_OPTIMAL_SPACE to vm_map_find().

MFC r278963:
If malloc() sleeps, Giant is dropped. Recheck for another thread
doing our work.

Remove unneeded check for failed M_WAITOK allocation.

MFC r282213:

Add kern.racct.enable tunable and RACCT_DISABLED config option.
The point of this is to be able to add RACCT (with RACCT_DISABLED)
to GENERIC, to avoid having to rebuild the kernel to use rctl(8).

MFC r282901:

Build GENERIC with RACCT/RCTL support by default. Note that it still
needs to be enabled by adding "kern.racct.enable=1" to /boot/loader.conf.

Note those two are MFC-ed together, because the latter one changes the
name of RACCT_DISABLED option to RACCT_DEFAULT_TO_DISABLED. Should have
committed the renaming separately...

Relnotes: yes
Sponsored by: The FreeBSD Foundation

MFC r282084:
Fix locking for oshmctl() and shmsys().

MFC r281094:
Restore proper error from oshmctl(2), broken by r280323.

MFC r281071:
Remove useless initialization.

MFC r280323:
Somewhat modernize the SysV shm code.

MFC r280325 (by cognet):
Fix warning for !MAC case.

MFC r278697 (by alc):
Preset the object's color, or alignment, to maximize superpage usage.

MFC r258056 (by alc):
Eliminate the gratuitous use of mmap(2) flags from the implementation
of kern_shmat(). Use a simpler approach to determine whether to pass
VMFS_NO_SPACE or VMFS_OPTIMAL_SPACE to vm_map_find().

MFC r278963:
If malloc() sleeps, Giant is dropped. Recheck for another thread
doing our work.

Remove unneeded check for failed M_WAITOK allocation.