To enable them, set WITH_GCC and WITH_GNUCXX in src.conf.
Make clang default to using libc++ on FreeBSD 10.
Bumped __FreeBSD_version for the change.
GCC is still enabled on PC98, because the PC98 bootloader requires GCC to build
(or, at least, hard-codes the use of gcc into its build).
Thanks to everyone who helped make the ports tree ready for this (and bapt
for coordinating them all). Also to imp for reviewing this and working on the
forward-porting of the changes in our gcc so that we're getting to a much
better place with regard to external toolchains.
Sorry to all of the people who helped who I forgot to mention by name.
Reviewed by: bapt, imp, dim, ...
functional state. While CTL is much more superior target from all points,
there is no reason why this code should not work.
Tested with ahc(4) as target side HBA.
MFC after: 2 weeks
This is a significant rewrite of much of the previous driver; lots of
misc. cleanup was also performed, and support for a few other minor
features was also added.
- Allow the Rx/Tx queue sizes to be configured by tunables
- Bail out earlier if the Tx queue unlikely has enough free
descriptors to hold the frame
- Cleanup some of the offloading capabilities handling
As promised, drop the option to make the older GNU patch
the default.
GNU patch is still being built but something drastic may
happen to it to it before Release.
This removes the WITH_BSDCONFIG description alltogether, since this option
is removed.
At the same time, fix the WITHOUT_LIBCPLUSPLUS option that had gotten
inverted.
There are now six additional variables
weekly_status_security_enable
weekly_status_security_inline
weekly_status_security_output
monthly_status_security_enable
monthly_status_security_inline
monthly_status_security_output
alongside their existing daily counterparts. They all have the same
default values.
All other "daily_status_security_${scriptname}_${whatever}"
variables have been renamed to "security_status_${name}_${whatever}".
A compatibility shim has been introduced for the old variable names,
which we will be able to remove in 11.0-RELEASE.
"security_status_${name}_enable" is still a boolean but a new
"security_status_${name}_period" allows to define the period of
each script. The value is one of "daily" (the default for backward
compatibility), "weekly", "monthly" and "NO".
Note that when the security periodic scripts are run directly from
crontab(5) (as opposed to being called by daily or weekly periodic
scripts), they will run unless the test is explicitely disabled with a
"NO", either for in the "_enable" or the "_period" variable.
When the security output is not inlined, the mail subject has been
changed from "$host $arg run output" to "$host $arg $period run output".
For instance:
myfbsd security run output -> myfbsd security daily run output
I don't think this is considered as a stable API, but feel free to
correct me if I'm wrong.
Finally, I will rearrange periodic.conf(5) and default/periodic.conf
to put the security options in their own section. I left them in
place for this commit to make reviewing easier.
Reviewed by: hackers@
kld_unload event handler which gets invoked after a linker file has been
successfully unloaded. The kld_unload and kld_load event handlers are now
invoked with the shared linker lock held, while kld_unload_try is invoked
with the lock exclusively held.
Convert hwpmc(4) to use these event handlers instead of having
kern_kldload() and kern_kldunload() invoke hwpmc(4) hooks whenever files are
loaded or unloaded. This has no functional effect, but simplifes the linker
code somewhat.
Reviewed by: jhb
* It's not meant to be used in a real system, it's there to show how
the basics of how to create interfaces for random_adaptors. Perhaps
it should belong in a manual page
2) Move probe.c's functionality in to random_adaptors.c
* rename random_ident_hardware() to random_adaptor_choose()
3) Introduce a new way to choose (or select) random_adaptors via tunable
"rngs_want" It's a list of comma separated names of adaptors, ordered
by preferences. I.e.:
rngs_want="yarrow,rdrand"
Such setting would cause yarrow to be preferred to rdrand. If neither of
them are available (or registered), then system will default to
something reasonable (currently yarrow). If yarrow is not present, then
we fall back to the adaptor that's first on the list of registered
adaptors.
4) Introduce a way where RNGs can play a role of entropy source. This is
mostly useful for HW rngs.
The way I envision this is that every HW RNG will use this
functionality by default. Functionality to disable this is also present.
I have an example of how to use this in random_adaptor_example.c (see
modload event, and init function)
5) fix kern.random.adaptors from
kern.random.adaptors: yarrowpanicblock
to
kern.random.adaptors: yarrow,panic,block
6) add kern.random.active_adaptor to indicate currently selected
adaptor:
root@freebsd04:~ # sysctl kern.random.active_adaptor
kern.random.active_adaptor: yarrow
Submitted by: Arthur Mesh <arthurmesh@gmail.com>
configure sa(4) to request no I/O splitting by default.
For tape devices, the user needs to be able to clearly understand
what blocksize is actually being used when writing to a tape
device. The previous behavior of physio(9) was that it would split
up any I/O that was too large for the device, or too large to fit
into MAXPHYS. This means that if, for instance, the user wrote a
1MB block to a tape device, and MAXPHYS was 128KB, the 1MB write
would be split into 8 128K chunks. This would be done without
informing the user.
This has suboptimal effects, especially when trying to communicate
status to the user. In the event of an error writing to a tape
(e.g. physical end of tape) in the middle of a 1MB block that has
been split into 8 pieces, the user could have the first two 128K
pieces written successfully, the third returned with an error, and
the last 5 returned with 0 bytes written. If the user is using
a standard write(2) system call, all he will see is the ENOSPC
error. He won't have a clue how much actually got written. (With
a writev(2) system call, he should be able to determine how much
got written in addition to the error.)
The solution is to prevent physio(9) from splitting the I/O. The
new cdev flag, SI_NOSPLIT, tells physio that the driver does not
want I/O to be split beforehand.
Although the sa(4) driver now enables SI_NOSPLIT by default,
that can be disabled by two loader tunables for now. It will not
be configurable starting in FreeBSD 11.0. kern.cam.sa.allow_io_split
allows the user to configure I/O splitting for all sa(4) driver
instances. kern.cam.sa.%d.allow_io_split allows the user to
configure I/O splitting for a specific sa(4) instance.
There are also now three sa(4) driver sysctl variables that let the
users see some sa(4) driver values. kern.cam.sa.%d.allow_io_split
shows whether I/O splitting is turned on. kern.cam.sa.%d.maxio shows
the maximum I/O size allowed by kernel configuration parameters
(e.g. MAXPHYS, DFLTPHYS) and the capabilities of the controller.
kern.cam.sa.%d.cpi_maxio shows the maximum I/O size supported by
the controller.
Note that a better long term solution would be to implement support
for chaining buffers, so that that MAXPHYS is no longer a limiting
factor for I/O size to tape and disk devices. At that point, the
controller and the tape drive would become the limiting factors.
sys/conf.h: Add a new cdev flag, SI_NOSPLIT, that allows a
driver to tell physio not to split up I/O.
sys/param.h: Bump __FreeBSD_version to 1000049 for the addition
of the SI_NOSPLIT cdev flag.
kern_physio.c: If the SI_NOSPLIT flag is set on the cdev, return
any I/O that is larger than si_iosize_max or
MAXPHYS, has more than one segment, or would have
to be split because of misalignment with EFBIG.
(File too large).
In the event of an error, print a console message to
give the user a clue about what happened.
scsi_sa.c: Set the SI_NOSPLIT cdev flag on the devices created
for the sa(4) driver by default.
Add tunables to control whether we allow I/O splitting
in physio(9).
Explain in the comments that allowing I/O splitting
will be deprecated for the sa(4) driver in FreeBSD
11.0.
Add sysctl variables to display the maximum I/O
size we can do (which could be further limited by
read block limits) and the maximum I/O size that
the controller can do.
Limit our maximum I/O size (recorded in the cdev's
si_iosize_max) by MAXPHYS. This isn't strictly
necessary, because physio(9) will limit it to
MAXPHYS, but it will provide some clarity for the
application.
Record the controller's maximum I/O size reported
in the Path Inquiry CCB.
sa.4: Document the block size behavior, and explain that
the option of allowing physio(9) to split the I/O
will disappear in FreeBSD 11.0.
Sponsored by: Spectra Logic
with rmlocks. This works only with non-sleepable rm because handlers run
in SWI context. While here, document the new KPI in the timeout(9)
manpage.
Requested by: adrian, scottl
Reviewed by: mav, remko(manpage)
Notable new features:
* Elliptic Curve Digital Signature Algorithm keys and signatures in
DNSSEC are now supported per RFC 6605. [RT #21918]
* Introduces a new tool "dnssec-verify" that validates a signed zone,
checking for the correctness of signatures and NSEC/NSEC3 chains.
[RT #23673]
* BIND now recognizes the TLSA resource record type, created to
support IETF DANE (DNS-based Authentication of Named Entities)
[RT #28989]
* The new "inline-signing" option, in combination with the
"auto-dnssec" option that was introduced in BIND 9.7, allows
named to sign zones completely transparently.
Approved by: delphij (mentor)
MFC after: 3 days
Sponsored by: DK Hostmaster A/S
existing examples to not pass an mbuf as a probe argument. There's no
obvious reason to have it there, and it doesn't really jibe with the example
added in this revision.
MFC after: 1 week
- Note that WORLD_FLAGS and KERNEL_FLAGS set the number of
make(1) jobs only on SMP-capable systems.
MFC after: 3 days
X-MFC-With: r254224
X-MFC-To: stable/9, releng/9.2
extensions and also tried to be link time compatible with ports libiconv.
This splits that functionality and enables the parts that shouldn't
interfere with the port by default.
WITH_ICONV (now on by default) - adds iconv.h, iconv_open(3) etc.
WITH_LIBICONV_COMPAT (off by default) adds the libiconv_open etc API, linker
symbols and even a stub libiconv.so.3 that are good enough to be able
to 'pkg delete -f libiconv' on a running system and reasonably expect it
to work.
I have tortured many machines over the last few days to try and reduce
the possibilities of foot-shooting as much as I can. I've successfully
recompiled to enable and disable the libiconv_compat modes, ports that use
libiconv alongside system iconv etc. If you don't enable the
WITH_LIBICONV_COMPAT switch, they don't share symbol space.
This is an extension of behavior on other system. iconv(3) is a standard
libc interface and libiconv port expects to be able to run alongside it on
systems that have it.
Bumped osreldate.
called after the module has been loaded, and the unload handlers are called
before the module is unloaded. Moreover, the module unload handlers may
return an error to prevent the unload from proceeding.
Reviewed by: avg
MFC after: 2 weeks
Release Engineering Team as of 9.2-RELEASE.
- Document that a cross-build release is possible by setting the
TARGET and TARGET_ARCH variables.
- Include an example of using release.sh with and without the
optional configuration file.
- Document the supported release.sh configuration file variables.
- Update the 'cdrom' target output file to disc1.iso.
- Update the 'memstick' target output file to memstick.img.
- Add attributions for the last major updates to this manual page.
- Fix some mdoc(7) style nits:
- Sentences should begin on a new line
- Use .Pq to enclose full lines in parenthesis
random_adaptor is basically an adapter that plugs in to random(4).
random_adaptor can only be plugged in to random(4) very early in bootup.
Unplugging random_adaptor from random(4) is not supported, and is probably a
bad idea anyway, due to potential loss of entropy pools.
We currently have 3 random_adaptors:
+ yarrow
+ rdrand (ivy.c)
+ nehemeiah
* Remove platform dependent logic from probe.c, and move it into
corresponding registration routines of each random_adaptor provider.
probe.c doesn't do anything other than picking a specific random_adaptor
from a list of registered ones.
* If the kernel doesn't have any random_adaptor adapters present then the
creation of /dev/random is postponed until next random_adaptor is kldload'ed.
* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
system wide one.
Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: so (des)
Now the MTX_RECURSE flag can be passed to the mtx_*_flag() calls.
This helps in cases we want to narrow down to specific calls the
possibility to recurse for some locks.
Sponsored by: EMC / Isilon storage division
Reviewed by: jeff, alc
Tested by: pho
Unify the 2 concept into a real, minimal, sxlock where the shared
acquisition represent the soft busy and the exclusive acquisition
represent the hard busy.
The old VPO_WANTED mechanism becames the hard-path for this new lock
and it becomes per-page rather than per-object.
The vm_object lock becames an interlock for this functionality:
it can be held in both read or write mode.
However, if the vm_object lock is held in read mode while acquiring
or releasing the busy state, the thread owner cannot make any
assumption on the busy state unless it is also busying it.
Also:
- Add a new flag to directly shared busy pages while vm_page_alloc
and vm_page_grab are being executed. This will be very helpful
once these functions happen under a read object lock.
- Move the swapping sleep into its own per-object flag
The KPI is heavilly changed this is why the version is bumped.
It is very likely that some VM ports users will need to change
their own code.
Sponsored by: EMC / Isilon storage division
Discussed with: alc
Reviewed by: jeff, kib
Tested by: gavin, bapt (older version)
Tested by: pho, scottl
Newly-configured systems should use $cloned_interfaces.
- Call clone_{up,down}() and ifnet_rename() in rc.d/netif {start,stop}.
ifnet_rename() now accepts an interface name list as its argument.
- Add rc.d/netif clear. The "clear" subcommand is basically equivalent to
"stop" but it does not call clone_down().
- Add "ifname:sticky" keyword into $cloned_interfaces. If :sticky is
specified, the interface will not be destroyed in rc.d/netif stop.
- Add cloned_interfaces_sticky={YES,NO}. This variable globally sets
:sticky keyword above for all interfaces. The default value is NO.
When cloned_interfaces_sticky=YES, :nosticky keyword can be used to
override it on per interface basis.
Support chipsets are the Realtek RTL8188SU, RTL8191SU, and RTL8192SU.
Many thanks to Idwer Vollering for porting/writing the man page and for
testing.
Reviewed by: adrian, hselasky
Obtained from: OpenBSD
Tested by: kevlo, Idwer Vollering <vidwer at gmail.com>
* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.
* random(4) device doesn't really depend on rijndael-*. Yarrow, however, does.
* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
random_adaptor is basically an adapter that plugs in to random(4).
random_adaptor can only be plugged in to random(4) very early in bootup.
Unplugging random_adaptor from random(4) is not supported, and is probably a
bad idea anyway, due to potential loss of entropy pools.
We currently have 3 random_adaptors:
+ yarrow
+ rdrand (ivy.c)
+ nehemeiah
* Remove platform dependent logic from probe.c, and move it into
corresponding registration routines of each random_adaptor provider.
probe.c doesn't do anything other than picking a specific random_adaptor
from a list of registered ones.
* If the kernel doesn't have any random_adaptor adapters present then the
creation of /dev/random is postponed until next random_adaptor is kldload'ed.
* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
system wide one.
Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien
The BSD-licensed patch(1) command has matured and it's behaviour
can be considered equivalent to the older version of GNU patch
in the tree.
The switch has been extensively tested [1] and only two ports
presented regressions, which have since been fixed.
For convenience a new WITH_GNU_PATCH option is available,
but it will likely be removed in the near future.
PR: 176313
Approved by: portmgr
make the ARM EABI the default ABI on arm, armeb, armv6 and armv6eb.
This is intended to be the default ABI from now on with the old ABI to be
retired. Because of this all users are strongly suggested to upgrade to the
ARM EABI.
As the two ABIs are incompatible it is unlikely upgrading in place will
work. Users should perform a full backup and either use an external machine
to upgrade, or install to an alternative location on their media. They
should also reinstall all ports or packages when these are available.
The only known issues are:
- pkg incorrectly detects the ABI. This is fixed upstream, and will a
patch will be made to the port.
- GDB can have issues with executables built with clang.
__FreeBSD_version has been bumped.
of Skyhawk adapters.
Many thanks to Emulex for their continued support of FreeBSD.
Submitted by: "Duvvuru,Venkat Kumar" <VenkatKumar.Duvvuru Emulex.Com>
MFC after: 1 day
controllers. Update the hptiop(4) manual page to reflect this
as well as mentioning that some cards are already end-of-life.
Many thanks to Highpoint for providing this driver update.
MFC after: 1 day
The notable changes of this commit are support for disk resizing
and chases updates to the spec regarding write caching.
Contains projects/virtio commits:
r245713:
virtio_blk: Replace __FUNCTION__ with __func__
r245714:
virtio_blk: Use more consistent mutex name
r245715:
virtio_blk: Print device name too if failed to reinit during dump
r245716:
virtio_blk: Remove an unuseful ASSERT
r245723:
virtio_blk: Record the vendor and device information
r245724:
virtio_blk: Add resize support
r245726:
virtio_blk: More verbose ASSERT messages
r245730:
virtio_blk: Tweak resize announcement message
r246061:
virtio_blk: Do not always read entire config
r246062:
virtio_blk: Use topology to set the stripe size/offset
r246307:
virtio_blk: Correct stripe offset calculation
r246063:
virtio_blk: Add support for write cache enable feature
r246303:
virtio_blk: Expand a comment
r252529:
virtio_blk: Improve write cache handling
r252681:
virtio_blk: Remove unneeded curly braces
MFC after: 1 month
algorithm, which is based on the 2011 v0.1 patch release and described in the
paper "Revisiting TCP Congestion Control using Delay Gradients" by David Hayes
and Grenville Armitage. It is implemented as a kernel module compatible with the
modular congestion control framework.
CDG is a hybrid congestion control algorithm which reacts to both packet loss
and inferred queuing delay. It attempts to operate as a delay-based algorithm
where possible, but utilises heuristics to detect loss-based TCP cross traffic
and will compete effectively as required. CDG is therefore incrementally
deployable and suitable for use on shared networks.
In collaboration with: David Hayes <david.hayes at ieee.org> and
Grenville Armitage <garmitage at swin edu au>
MFC after: 4 days
Sponsored by: Cisco University Research Program and FreeBSD Foundation
- Reconnect with some minor modifications, in particular now selsocket()
internals are adapted to use sbintime units after recent'ish calloutng
switch.
some general word-smithing.
- Don't claim that adaptive mutexes have a timeout (they don't).
- Don't treat pool mutexes as a separate primitive in a few places.
- Describe sleepable read-mostly locks as a separate lock type and add
them to the various tables.
- Don't claim that sx locks are less efficient. That hasn't been true in
a few years now.
- Describe lockmanager locks next to sx locks since they are very similar
in terms of rules, etc., and so that all the lock primitives are
grouped together before the non-lock primitives.
- Similarly, move the section on Giant after the description of all the
non-lock primitives to preserve grouping.
- Condition variables work on several types of locks, not just mutexes.
- Add a bit of language to compare/contrast condition variables with
sleep/wakeup.
- Add a note about why pause(9) is unique.
- Add some language to define bounded vs unbounded sleeps and explain
why they are treated separately (bounded sleeps only need CPU time
to make forward progress).
- Don't state that using mtx_sleep() is a bad idea. It is in fact rather
necessary.
- Rework the interaction table a bit. First, it did not include really
include sleepable rmlocks and it left out lockmgr entirely. To get
things to fit, combine similar lock types into the same column / row,
and explicitly state what "sleep" means. The notes about recursion
and lock order were also a bit banal (lock order is always important,
not just in the few places annotated here), so remove them. In
particular, the lock order note would need to be on just about every
cell. If we want to document recursion I think a better approach
would be a separate table summarizing the recursion rules for each
lock as having too many notes clutters the table.
- Tweak the tables to use less indentation so everything still fits with
the added columns.
- Correct a few cells in the context mode table.
- Use mdoc markup instead of explicit markup in a few places.
Requested by: julian
MFC after: 2 weeks
device names "md" or "md[0-9]*" and a "file" option are specified in
/etc/fstab like this:
md none swap sw,file=/swap.bin 0 0
- Add GBDE/GELI encrypted swap space specification support, which
rc.d/encswap supported. The /etc/fstab lines are like the following:
/dev/ada1p1.bde none swap sw 0 0
/dev/ada1p2.eli none swap sw 0 0
.eli devices accepts aalgo, ealgo, keylen, and sectorsize as options.
swapctl(8) can understand an encrypted device in the command line
like this:
# swapctl -a /dev/ada2p1.bde
- "-L" flag is added to support "late" option to defer swapon until
rc.d/mountlate runs.
- rc.d script change:
rc.d/encswap -> removed
rc.d/addswap -> just display a warning message if $swapfile is defined
rc.d/swap1 -> renamed to rc.d/swap
rc.d/swaplate -> newly added to support "late" option
These changes alleviate a race condition between device creation/removal
and swapon/swapoff.
MFC after: 1 week
Reviewed by: wblock (manual page)
provided by Isilon.
- Add an rm_assert() supporting various lock assertions similar to other
locking primitives. Because rmlocks track readers the assertions are
always fully accurate unlike rw_assert() and sx_assert().
- Flesh out the lock class methods for rmlocks to support sleeping via
condvars and rm_sleep() (but only while holding write locks), rmlock
details in 'show lock' in DDB, and the lc_owner method used by
dtrace.
- Add an internal destroyed cookie so that API functions can assert
that an rmlock is not destroyed.
- Make use of rm_assert() to add various assertions to the API (e.g.
to assert locks are held when an unlock routine is called).
- Give RM_SLEEPABLE locks their own lock class and always use the
rmlock's own lock_object with WITNESS.
- Use THREAD_NO_SLEEPING() / THREAD_SLEEPING_OK() to disallow sleeping
while holding a read lock on an rmlock.
Submitted by: andre
Obtained from: EMC/Isilon
This is an extended version of ipv4_addr_IF which supports both IPv4 and
IPv6, and multiple range specifications. To avoid to generate too many
addresses, the maximum number of the generated addresses is currently
limited to 31.
- Add $ifconfig_IF_aliases, which accepts multiple IP aliases in a variable.
- ipv6_prefix_IF now supports !/64 prefix length. In addition to the old
64-bit format (2001:db8:1:1), a full 128-bit format like 2001:db8:1:1::/64
is supported.
- Replace ifconfig command with $IFCONFIG_CMD variable to support
a dry-run mode in the future.
- Remove IP aliases before removing all of IPv4 addresses when doing
"rc.d/netif down".
- Add a DAD wait to network6_getladdr() because it is possible to fail to
configure an EUI64 address when ipv6_prefix_IF is specified.
A summary of the supported ifconfig_* variables is as follows:
# IPv4 configuration.
ifconfig_em0="inet 192.168.0.1"
# IPv6 configuration.
ifconfig_em0_ipv6="inet6 2001:db8::1/64"
# IPv4 address range spec. Now deprecated.
ipv4_addr_em0="10.2.1.1-10"
# IPv6 alias.
ifconfig_em0_alias0="inet6 2001:db8:5::1 prefixlen 70"
# IPv4 alias.
ifconfig_em0_alias1="inet 10.2.2.1/24"
# IPv4 alias with range spec w/o AF keyword (backward compat).
ifconfig_em0_alias2="10.3.1.1-10/32"
# IPv6 alias with range spec.
ifconfig_em0_alias3="inet6 2001:db8:20-2f::1/64"
# ifconfig_IF_aliases is just like ifconfig_IF_aliasN.
ifconfig_em0_aliases="inet 10.3.3.201-204/24 inet6 2001:db8:210-213::1/64 inet 10.1.1.1/24"
# IPv6 alias (backward compat)
ipv6_ifconfig_em0_alias0="inet6 2001:db8:f::1/64"
# IPv6 alias w/o AF keyword (backward compat)
ipv6_ifconfig_em0_alias1="2001:db8:f:1::1/64"
# IPv6 prefix.
ipv6_prefix_em0="2001:db8::/64"
Tested by: Kimmo Paasiala
optionally start the traversal from a previously found element by passing the
element in as "var". Passing a NULL "var" retains the same semantics as the
regular FOREACH macros.
Kudos to phk for suggesting the "FROM" suffix instead of my original proposal.
Reviewed by: jhb (previous version), rpaulo
MFC after: 1 week
This is actually a fully functional build except:
* All internal shared libraries are static linked to make sure there
is no interference with ports (and to reduce build time).
* It does not have the python/perl/etc plugin or API support.
* By default, it installs as "svnlite" rather than "svn".
* If WITH_SVN added in make.conf, you get "svn".
* If WITHOUT_SVNLITE is in make.conf, this is completely disabled.
To be absolutely clear, this is not intended for any use other than
checking out freebsd source and committing, like we once did with cvs.
It should be usable for small scale local repositories that don't
need the python/perl plugin architecture.
But we don't want to set it to + for bmake since it breaks make -N
which is used to supress the normal handling of targets marked with .MAKE
(which seems broken in fmake and might be why _+_ was introduced).
Add some comments to explain what's gong on.
Reviewed by: obrien
- remove return statements from void function [1]
- include missing header
- use O_CLOEXEC instead of separate fcntl() calls
PR: docs/179459 [1]
MFC after: 1 week
