Document that VSCSI_I2T is a non-blocking operation and can be
monitored with select(2).
Convert several calloc calls to reallocarray.  These calloc calls were
originally malloc(n * m) calls (without memset/bzero) in the past.

ok deraadt@ tedu@
Work around compatibility problems with Intel ahci and Intel SSDs by retrying
device detection if the port is still busy after our normal timeout.

based on a diff by chris@, based on a change in dragonflybsd
tested by Peter J Philipp
ok dlg@
fix format string when compiled with VIRTIO_DEBUG

ok sf@
Calling in{6,}_purgeaddr() is not enough to remove an address from
an interface.  Two other operations are performed when issuing a
SIOCDIFADDR{_IN6,} ioctl: call the address hook and the per-driver
ioctl function.

Since carp(4) relies on an address hook to recalculate its hash, make
sure to call this hook when IFXF_NOINET6 is set or when the rdomain is
changed.

ok henning@, mikeb@
fix HD() misuse; from brent cook
save errno in ERR_put_error(), so that SYSerr doesn't have any accidental
cases where errno can be trashed.
ok jsing
Do not redirect STDERR of the main security(8) script to /dev/null,
not even for calling three particular functions, as that carries a risk
of hiding serious errors in the security(8) script itself: otto@ found
and reported a bug (already fixed by now) where that hurt him.

Instead, only do the redirection where it is really needed, that is,
inside the forked csh(1) child process.  The csh(1) "eval" builtin is
required because the csh(1) "source" builtin apparently ignores
redirections.

No objections came up when showing this diff on tech@.
Create temporary file with mkstemp and unlink if rename operation fails.

ok deraadt@, henning@
Document that mmap() confirms to POSIX 2008, except that we generate
SIGSEGV instead of SIGBUS for page references beyond the end of a
mapped object.
Add back an #ifndef MAP_INHERIT_ZERO chunk to support the old getpid()
mechanism, to aid in portability to other systems as requested.
ok matthew