Another fix for r253823; retain the default of 1 readahead block for sendfile.

Submitted by:	glebius
Obtained from:	Netflix
MFC after:	3 days
Allocate in6_ifextra (ifp->if_afdata[AF_INET6]) only for IPv6-capable
interfaces.  This eliminates unnecessary IPv6 processing for non-IPv6
interfaces.

MFC after:	3 days
device if_bridge gets me a bridge device
Document net.link.bridge.allow_llz_overlap.
Adjust magic numbers to allow attachment of ath(4) modules.
Back out r253779 & r253786.
Add myself as maintainer for nvme(4), nvd(4) and nvmecontrol(8).
Changes to allow using BOOTP_NFSROOT and mounting an nfs root filesystem
other than the one specified by the BOOTP server.  This configures NFS
using the BOOTP protocol while also respecting other root-path options such
as setting vfs.root.mountfrom in the environment or using the RB_DFLTROOT
boot option.  It allows you to override the root path provided by the
server, or to supply a root path when the server provides IP configuration
but no root path info.

This maintains the historical BOOTP_NFSROOT behavior of panicking on a
failure to mount the root path provided by the server, unless you've
provided an alternative via the ROOTDEVNAME kernel option or by setting
vfs.root.mountfrom.  The behavior of panicking when given no other options
is preserved because it amounts to a bit of a retry loop that could
eventually recover from a transient network or server problem.

The user can now override the root path from loader(8) even if the
kernel is compiled with BOOTP_NFSROOT.  If vfs.root.mountfrom is set in
the environment it is used unconditionally -- it always overrides the
BOOTP info.  If it begins with [old]nfs: then the BOOTP code uses it
instead of the server-provided info.  If it specifies some other
filesystem then the bootp code will not panic like it used to and the code
in vfs_mountroot.c will invoke the right filesystem to do the mount.

If the kernel is compiled with the ROOTDEVNAME option, then that name is
used by the BOOTP code if either
      * The server doesn't provide a pathname.
      * The boothowto flags include RB_DFLTROOT.
The latter allows the user to compile in alternate path in ROOTDEVNAME
such as ufs:/dev/da0s1a and boot from that path by setting
boot_dftlroot=1 in loader(8) or using the '-r' option in boot(8).

The one thing not provided here is automatic failover from a
server-provided path to a compiled-in one without the user manually
requesting that.  The code just isn't currently structured in a way that
makes that possible with a lot of rewrite.  I think the ability to set
vfs.root.mountfrom and to use ROOTDEVNAME automatically when the server
doesn't provide a name covers the most common needs.

A set of patches submitted by Lars Eggert provided the part I couldn't
figure out by myself when I tried to do this last year; many thanks.

Reviewed by:	rodrigc
Correctly maintain the CR0/CR4 shadow registers.
This was exposed with AP spinup of Linux, and
booting OpenBSD, where the CR0 register is unconditionally
written to prior to the longjump to enter protected
mode. The CR-vmexit handling was not updating CPU state which
resulted in a vmentry failure with invalid guest state.

A follow-on submit will fix the CPU state issue, but this
fix prevents the CR-vmexit prior to entering protected
mode by properly initializing and maintaining CR* state.

Reviewed by:	neel
Reported by:	Gopakumar.T @ netapp
Properly print arguments to vfork(2) and rfork(2).

PR:		180976
Submitted by:	Yuri <yuri@tsoft.com> (original patch)
MFC after:	1 week
Fix boundary check of sockaddr array.

Reported by:	uqs
Include /usr/local/etc/libmap.d/ by default.

PR:		180568
Reviewed by:	bapt
Obtained from:	kib
MFC after:	3 days
Moved clearing of vmm_initialized to avoid the case
of unloading the module while VMs existed. This would
result in EBUSY, but would prevent further operations
on VMs resulting in the module being impossible to
unload.

Submitted by:   Tycho Nightingale (tycho.nightingale <at> plurisbusnetworks.com)
Reviewed by:	grehan, neel
Add identification for Cortex-A7 (R0) cores.

Reviewed by: cognet@
Micro-optimization suggested in
https://bugzilla.mozilla.org/show_bug.cgi?id=898234
by pchang9. While there simplify the code.

MFC after: 1 week
Remove unused malloc type.

Requested by:	alc
MFC after:	1 week
Add license for the half MD4 algorithm used in ext2_half_md4().

The htree implementation uses code derived from the
RSA Data Security, Inc. MD4 Message-Digest Algorithm.

Add a proper licensing statement for the code and clarify
the corresponding comments.

Approved by:	core (hrs)
Fix the build of the testmain target. This target compiles a Forth
interpreter that can be run on the system and as such cannot be
compiled against libbstand. On the one hand this means we need to
include the usual headers for system interfaces that we use and
on the the other hand we can only use standard system interfaces.

While here, define local variables only when needed to make this
WARNS=2 clean on amd64.

PR:		172542
Obtained from:	peterj@
Pointed out by: Jan Beich <jbeich@tormail.org>
A number of important fixes:
  - mbuf reused after an RX_COPY optimized operation can sometimes have
    a bogus cached address, resulting in TCP hangs. Add critical save points
    to the cached address. Thanks to Michael and the team at Verisign for
    finding this problem.
  - A couple more spots where the rxbuf->flags member should be cleared just
    to be sure no incorrect RX_COPY state is left around. Thanks to Adrian
    for tracking these down.
  - Remove the rearm_queues function from the driver, this was found to be
    responsible for some out-of-order packets by Verisign, and was always a
    bandaid, with the other fixes in this delta the bandaid can finally be
    removed.
  - In the other/link interrupt handler the entire state of the EICS register
    was being writen back into EICR (which clears causes and thus re-enables
    those interrupts), this was wrong, so now mask off the queue portion of
    the register value, so we only clear the other/link interrupt we intend.
    Marc from Verisign found this.
  - Make the SFP+ unsupported option tuneable now, by customer request.
  - Finally, just a couple of minor DEBUG string fixes.

I want to call out and thank all the participants in the 10G community/Intel
calls for helping track down these problems and make the driver better for
everyone!

MFC after:	3 days, these are critical fixes for 9.2!
iwn(4) debugging improvements.

* Add in some new register debugging under IWN_DEBUG_REGISTER
* Make IWN_DEBUG an option now for building.  I'll chase this up
  with a commit to 'options' soon.

Submitted by:	Cedric GROSS <cg@cgross.info>