Plug memory leaks.

Coverity CID:	1087993, 1087992
Approved by:	re (marius)
Sponsored by:	FreeBSD Foundation
Fix memory overrun.

Coverity CID:	1092478
Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
Plug memory leak.

Coverity CID:	1087991
Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
Tidy up, cache return value of a function, and add an assertion;
shouldn't make any functional difference.

Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
Remove redundant redeclarations of uart_s3c2410_class in
sys/arm/s3c2xx0/uart_bus_s3c2410.c and uart_cpu_s3c2410.c, to silence
two gcc warnings.

Approved by:	re (gjb)
X-MFC-With:	r252394
Make the error handling more consistant.  Shouldn't make any functional
difference.

Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
Revert r256095, r256120 (partial), r256121:

r256095:
 - Add gnu/usr.bin/rcs back to the base system.

r256120:
 - Add WITHOUT_RCS back to src.conf.5.

r256121:
 - Remove UPDATING entry regarding gnu/usr.bin/rcs removal.

Requested by:	many
Approved by:	re (marius)
Discussed with:	core
Initialize a variable in sys/contrib/ipfilter/netinet/ip_rcmd_pxy.c, to
silence a gcc warning.

Approved by:	re (gjb)
X-MFC-With:	r255332
Update the Intel igb driver to version 2.4.0
  - This version has support for the new Intel Avoton systems,
including 2.5Gb support, further it now has IPv6/TSO6 support as
well. Shared code has been updated where necessary as well. Thanks
to my new assistant Eric Joyner for doing the transmit path changes
to bring in the IPv6/TSO6 support. Thanks to Gleb for catching the
one bug and change needed in NETMAP.

Approved by: re
Remove no longer useful debugging output and a stale comment.

Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
MFC - tracking commit
Wrap some policy-rich code in 'if NOTYET' until we can thresh out what it really needs to do.
staticize struct random_hardware_source
Sigh. I can't even get a single #ifdef right. Who's got the hat?
Reduce code duplication, introduce the getmaxfd() helper to calculate
the max filedescriptor index.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (marius)
When growing the file descriptor table, new larger memory chunk is
allocated, but the old table is kept around to handle the case of
threads still performing unlocked accesses to it.

Grow the table exponentially instead of increasing its size by
sizeof(long) * 8 chunks when overflowing. This mode significantly
reduces the total memory use for the processes consuming large numbers
of the file descriptors which open them one by one.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (marius)
Do not flush buffers when the v_object of the passed vnode does not
really belong to it. Such vnodes, with the pointers to other vnodes
v_objects, are typically instantiated by the bypass filesystems.
Invalidating mappings of other vnode pages and the pages is wrong,
since reclamation of the upper vnode does not imply that lower vnode
is reclaimed too.

One of the consequences of the improper reclamation was destruction of
the wired mappings of the lower vnode pages, triggering miscellaneous
assertions in the VM system.

Reported by:    John Marshall <john.marshall@riverwillow.com.au>
Tested by:      John Marshall <john.marshall@riverwillow.com.au>, pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (gjb)
The device vnodes are often unlocked when bread() or bwrite() is
called.  This probably should be fixed eventually, but for now it is
not needed to try to flush such vnodes from the buffer allocation
context.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (gjb)
  There are some high performance NICs that count statistics in hardware,
and there are ifnets, that do that via counter(9). Provide a flag that
would skip cache line trashing '+=' operation in ether_input().

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
Reviewed by:	melifaro, adrian
Approved by:	re (marius)
Fail connection upon receiving too large data segment.

Approved by:	re (glebius)
Sponsored by:	FreeBSD Foundation