Clean up the libunbound build to avoid accidentally regenerating the
configuration lexer and parser during buildworld.  Instead of being
included in the source as it is in the upstream distribution, the code is
now always generated (in ${.OBJDIR}) at build time.

PR:		190739
MFC after:	1 week
Check if the specified group is the user's primary group before
iterating over the (possibly empty) list of members.  Otherwise, we
get a false negative when the target group has no members listed in
/etc/group.  This went mostly unnoticed because root is explicitly
listed as a member of wheel, so the bug is never triggered in the most
common use case, which is su(8).

PR:		109416
MFC after:	1 week
Handle nested exceptions in bhyve.

A nested exception condition arises when a second exception is triggered while
delivering the first exception. Most nested exceptions can be handled serially
but some are converted into a double fault. If an exception is generated during
delivery of a double fault then the virtual machine shuts down as a result of
a triple fault.

vm_exit_intinfo() is used to record that a VM-exit happened while an event was
being delivered through the IDT. If an exception is triggered while handling
the VM-exit it will be treated like a nested exception.

vm_entry_intinfo() is used by processor-specific code to get the event to be
injected into the guest on the next VM-entry. This function is responsible for
deciding the disposition of nested exceptions.
Add support for the "account" facility.

PR:		115164
MFC after:	1 week
Add dl_unwind_find_exidx() for ARM EABI, required for C++ exception
handling.  For statically linked apps this uses the __exidx_start/end
symbols set up by the linker.  For dynamically linked apps it finds the
shared object that contains the given address and returns the location and
size of the exidx section in that shared object.

The dl_unwind_find_exidx() name is used by other BSD projects and Android,
and is mentioned in clang 3.5 comments as "the BSD interface" for finding
exidx data.  GCC (in libgcc_s) expects the exact same API and functionality
to be provided by a function named __gnu_Unwind_Find_exidx(), so we provide
that with an alias ("strong reference").

Reviewed by:	kib@
MFC after:	1 week
Enable X11 via xf86-video-scfb on the Playstation 3. This commit made from
an xterm running for the first time on said Playstation.
Fix allocation of 128MB extended memory region, broken since some careless
modifications in December.

MFC after:	3 days
Correctly program the RSS redirection table entries.

Without this, the RSS bucket assignments aren't correct - they're
DCBA instead of ABCD in each DWORD.

Tested:	82599EB ixgbe(4), TCP and UDP RSS
Update the comment to be more concise.
Implement rss_gethashconfig() - return the currently supported hash methods
by the stack.

Right now the stack isn't really setup for RSS with 4-tuple UDP hashing
for either IPv4 and IPv6.

The specifics:

* The UDP init path udp_init() and udplite_init() specify the hash as
  2-tuple, so the PCBGROUPS code only tries a 2-tuple check;
* The PCBGROUPS and RSS code doesn't know about the UDP hash types
  just yet, so they're never treated as valid hashes.
* For correctness, 4-tuple can't be enabled in the general case because
  UDP datagrams can be more fragmented than IP datagrams may be.

Strictly speaking, TCP datagrams may also be fragmented and this could
cause issues with PCBGROUPS/RSS until the IP defragment path grows some
code to re-calculate the RSS hash.

I'll follow this commit up with awareness of the UDP 4-tuple for those
who wish to configure it, but for now it'll stay disabled.

No drivers (yet) know to use this function when RSS is enabled.
Add hash awareness of the IPv4 and IPv6 UDP 4-tuple.

Note: it would be nice if the supported hash check would be used here!
Make the PCBGROUPS code aware of IPv4 UDP 4-tuple.
When it's time to do 4-tuple UDP IPv6 hashing, make sure this is a known
type.
Disable the ixgbe(4) UDP 4-tuple hashing for the time being.

A mix of fragmented and non-fragmented UDP in a single stream will end up
being hashed differently, resulting in out-of-order behaviour in the receive
path.

This was done in the linux e1000 driver in 2011.

Discussed with:	jfv
Teach ixgbe(4) about rss_gethashconfig().

If RSS is enabled, ixgbe(4) will query the RSS API for the types of hashes
which should be used.  It'll then only enable hashes that are exposed via
the RSS layer.

This way it won't try to do things like enable UDP hashing if RSS explicitly
states that it isn't supported in lookups.

Tested:

* 82599EB ixgbe(4) NIC
Add the UDP hash -> RSS mbuf hash type for the ixgbe(4) driver.
sh: Remove prefix() function. Use strncmp() instead.
Older versions of flex (like the one used in FreeBSD <= 9) expect the
output file name to follow the -o flag immediately, with no intervening
whitespace.

Reported by:	ian@
MFC after:	1 week
Fix build without INVARIANTS defined by getting rid of unused variable 'exc'.

Reported by:	adrian, stefanf
Fix the build when DTrace isn't enabled.

Reported by:	stefanf
X-MFC-With:	r268600