MFC r264243:

Loosen the processing of *_IF_aliasN vars to be less strict. Previously,
the first alias had to be _alias0 and processing stopped at the first non-
defined variable (preventing gaps). Allowing gaps gives the administrator
the ability to group aliases in an adhoc manner and also lifts the
requirement to renumber aliases simply to comment-out an existing one.
Aliases are processed in numerical ascending order.

NB: Also Patches mdconfig{,2} rc(8) boot scripts to loosen the numbering
scheme for mdconfig_mdN settings to be less strict in the same manner.

Discussed on:	-rc
MFC r264343:
  Add SRC_UPDATE_SKIP, DOC_UPDATE_SKIP, and PORTS_UPDATE_SKIP
  variables.  These are intended to allow bypassing the
  'svn co /usr/{src,doc,ports}' step in the chroot when the
  tree exists from external means.

  The use case here is that /usr/src, /usr/doc, and /usr/ports
  in the chroot exist as result of zfs dataset clones, so it
  is possible (and happens quite often) that the included
  distributions may not be consistent.  (This is not the case
  for -RELEASE builds, but does happen for snapshot builds.)

Sponsored by:	The FreeBSD Foundation
MFC r263957:
  Increase the number of TX DMA segments from 32 to 35.  It turned
  out 32 is not enough to support a full sized TSO packet.
  While I'm here fix a long standing bug introduced in r169632 in
  bce(4) where it didn't include L2 header length of TSO packet in
  the maximum DMA segment size calculation.
MFC r259543:
  Failed m_devget(9) indicates lack of free mbuf cluster.  Update
  if_iqdrops counter for that case since the received frame is ok.
  While here, simplify updating counter logic.
MFC r260429:
  m_defrag(9) does not touch original mbuf chain when it can't
  allocate new mbuf.  Free original mbuf chain when driver is not
  able to send the packet.
MFC r264448: Fix typo in debug/log statement.

Submitted by:	Rick Miller <vmiller@hostileadmin.com>
MFC r264220:
Execute pf_overload_task() in vnet context. Fixes a vnet kernel panic.

Reviewed by:	trociny
MFC 264242,264244,264259

Fix panic on load new driver while vt(4) is in VGA textmode.
o Mute terminal while vt(4) driver change in progress.
o Reset VDF_TEXTMODE before init new driver.
o Assign default font, if new driver is not in TEXTMODE.
o Do not update screen while driver changing.
o Unmute terminal when done with driver replacement.
o Move init fonts to early point.
o Minor cleanup.
o Do not fill screen, while muted. (kern/subr_terminal.c)

Sponsored by:	The FreeBSD Foundation
MFC various fixes to the tools/regression/ tests.

- r262953 Fix m4 tests so that they run cleanly with prove.
- r262954 Fix printf tests so that they run cleanly with prove.
- r262959 Fix sed tests so that they run cleanly with prove.
- r262960 Fix yacc tests so that they run cleanly with prove.
- r262961 Fix pkill tests so that they run cleanly with prove.
- r262962 Fix ncal tests so that they run cleanly with prove.
- r263081 Fix lastcomm tests under amd64.
- r263082 Only run the make tests when make is fmake.
- r263083 Fix sa tests.
- r263084 Turn a test precondition into a skip in the mdconfig tests.
- r263085 Make the strerror tests work without libtap.
- r263087 Remove broken tests for eui64_line.
- r263221 Change etcupdate tests to return 1 on test failures.
- r263352 Make the priv test program exit with non-zero if any failures are detected.
- r263353 errx prepends the program name to the message; don't do it by hand.
- r263362 Include strings.h so that bpf_filter.c can be built in userland.
MFC r264345:

Amend r263891, by making clang default to DWARF2 debug info format for
all FreeBSD versions, not just 10.x and earlier.  Apparently too many
people seem to have trouble with post-1993 formats.

Also remove the related notes about messing with kernel configuration
files from UPDATING, which are now superfluous.

Requested by:	many
MFC r260866,260900,261960 (3 revisions; summarized below):
260866: Fix a bad comparison operator and fix dumpdev comment
260900: Dummy commit; show r260866 was in-part by Christoph Mallon
261960: Add zfsboot to bsdinstall(8) scripted interface
MFC: r264349

mdoc and spelling cleanup.
MFC: r264362

Remove stray .Nm macro.
MFC r263777: sh: Fix possible memory leaks and double frees with unexpected
SIGINT.
MFC refactoring of the *.test.mk files.

- r263161 Make bsd.test.mk the only public mk fragment for the building of tests.
- r263172 Move FreeBSD Test Suite-specific code to a suite.test.mk file.
- r263204 Add some documentation for bsd.test.mk.
- r263217 Document support for TAP-compliant Perl test programs.

This is "make tinderbox" clean.
MFC: 264016

Silence an unnecessary warning.
MFC r262812

- Gracefully handle truncation failures when trying to shrink directories.
  This could cause dirhash panics since the dirhash state would be
  successfully truncated while the directory was not.

Submitted by:   jeffr
MFC r262814

- If we fail to do a non-blocking acquire of a buf lock while doing a
  waiting sync pass we need to do a blocking acquire and restart.
  Another thread, typically the buf daemon, may have this buf locked and
  if we don't wait we can fail to sync the file.  This lead to a great
  variety of softdep panics because we rely on all dependencies being
  flushed before proceeding in several cases.

Submitted by:	jeffr
MFC r264229

Add some assertions to ensure that the target array doesn't get accessed
out of bounds.
MFC r261558

Add a new sysctl, dev.cxgbe.N.rsrv_noflow, and a companion tunable,
hw.cxgbe.rsrv_noflow.  When set, queue 0 of the port is reserved for
TX packets without a flowid.  The hash value of packets with a flowid
is bumped up by 1.  The intent is to provide a private queue for
link-level packets like LACP that is unlikely to overflow or suffer
deep queue latency.