xen: fix out-of-bounds access to ipi_handle

Fix the gate in xen_pv_lapic_ipi_vectored to prevent access to element
at position nitems(xen_ipis).

Sponsored by: Citrix Systems R&D
Coverity ID: 1223203
Approved by: gibbs
Use proper term in debug messages.

MFC after:	1 month
Sponsored by:	FreeBSD Foundation
Improve code a little; no functional changes.

Sponsored by:	The FreeBSD Foundation
Rework session termination in iSCSI target to actually wait
for any outstanding commands to be properly aborted by CTL.
Without it, in some cases (such as files backing the LUNs
stored on failing disk drives), terminating a busy session
would result in panic.

Reviewed by:	mav@ (earlier version)
Sponsored by:	The FreeBSD Foundation
Fix typo and rename macro KDB_SYS_FLAG to KBD_SYS_FLAG.

Reviewed by:	tychon
Get rid of unneccessary argument.

Sponsored by:	The FreeBSD Foundation
Implement redirection handling in initiator.

Sponsored by:	The FreeBSD Foundation
Add "iscsictl -M", which allows one to change session parameters
without removing it and adding back.

Sponsored by:	The FreeBSD Foundation
Rename a variable; no functional changes.

Sponsored by:	The FreeBSD Foundation
Retooling addrconfig() to exclude addresses on loopback interfaces
when looking for configured addresses.
This change is based upon the code from the submitter, and made
following changes:
- Exclude addresses assigned on interfaces which are down, like NetBSD
  does.
- Exclude addresses assigned on interfaces which are ifdisabled.

PR:		190824
Submitted by:	Justin McOmie
MFC after:	1 week
Fix spelling, typos, missing articles, contractions.  Expanded version
of patch supplied with PR.

PR:		191001
Submitted by:	olgeni
MFC after:	1 week
Fix syntax error.

PR:		191131
Submitted by:	dan.mcgregor@usask.ca
MFC after:	1 week
Rename vt(4) vga module to dismiss interference with syscons(4) vga module.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Remove stale link to deleted vt(4) xboxfb driver.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
syscons(4) and vt(4) can be built together now.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Allow to disable syscons(4) if "hw.syscons.disable" kenv is set.

Sponsored by:	The FreeBSD Foundation
Suspend vt(4) initialization if "kern.vt.disable" kenv is set.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
strptime: add support for %t and %n

Posix strptime() requires support for %t and %n, which were added
to the illumos port.  Curiously we were skipping white spaces by
default in most other cases making %t meaningless.

We now skip spaces in the case of the %e specifier as strftime(3)
explicitly adds a space for the single digit case.

Reference:
http://pubs.opengroup.org/onlinepubs/009695399/functions/strptime.html

Obtained from:	Illumos (Rev. a11c1571b6942161b0186d0588609448066892c2)
MFC after:	3 weeks
The time come to remove the wrapper, most likely, but tidy up it code
instead for now.  Remove spurious blank line, use C89 definition, wrap
long line.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Add MAP_EXCL flag for mmap(2).  It should be combined with MAP_FIXED,
and prevents the request from deleting existing mappings in the
region, failing instead.

Reviewed by:	alc
Discussed with:	jhb
Tested by:	markj, pho (previous version, as part of the bigger patch)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week