Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Fix kernel core dumps now that the kernel is using PBVM. The basic
problem to solve is that we don't have a fixed mapping from kernel
text to physical address so that libkvm can bootstrap itself. We
solve this by passing the physical address of the bootinfo structure
to the consumer as the entry point of the core file. This way,
libkvm can extract the PBVM page table information and locate the
kernel in the core file.
We also need to dump memory chunks of type loader data, because
those hold the kernel and the PBVM page table (among other things).

Approved by: re (blanket)

Add the watchdogs patting during the (shutdown time) disk syncing and
disk dumping.
With the option SW_WATCHDOG on, these operations are doomed to let
watchdog fire, fi they take too long.

I implemented the stubs this way because I really want wdog_kern_*
KPI to not be dependant by SW_WATCHDOG being on (and really, the option
only enables watchdog activation in hardclock) and also avoid to
call them when not necessary (avoiding not-volountary watchdog
activations).

Sponsored by: Sandvine Incorporated
Discussed with: emaste, des
MFC after: 2 weeks

Place hostnames and similar information fully under the prison system.
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex. Jails may
have their own host information, or they may inherit it from the
parent/system. The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL. The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.

The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.

Approved by: bz (mentor)

Collect N identical (or near identical) mkdumpheader() implementations into
one, as threatened in the comment. Textdump magic can be passed in.

Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch

Add a wrapper function that bound checks writes to the dump device.

Fix a buglet that was present in the ia64 code and that got inherited
by amd64 and i386: For buffered writes we collect data and write it
out a ${DEV_BSIZE}-sized block at a time. The fragsz variable is used
to keep track of how much data we have collected in the buffer so far
and it's reset to zero immediately after writing a block to the dump
device.
When the last, possibly partially filled buffer is flushed, we didn't
reset fragsz to 0 and as such would stop reflecting reality. Since we
currently only need to do buffered writes once, this isn't a problem.
However, when kernel dumps are made by hand (say by callling doadump
from within DDB), the improperly cleared state from the first call to
dumpsys causes the next call to dumpsys to create an invalid code file.
This change resets fragsz after flushing the partially filled buffer so
that it fixes the two problems at once.

Approved by: re (scottl)

/* -> /*- for copyright notices, minor format tweaks as necessary

MFp4:
Completely remove the remaining EFI includes and add our own (type)
definitions instead. While here, abstract more of the internals by
providing interface functions.

Don't use NULL with integral types.

Check that the dump device is large enough. Otherwise we could
end up with a dump offset that's smaller than the start of the
dump device and either clobber data in preceding partitions or
try to write beyond the end of the medium (unsigned wrap).

Implement legacy behaviour to never write to the first 64KB as
that is where metadata (ie disklabels) may reside.

In cb_dumphdr() we were calling buf_write() with di->priv as the
pointer to a dumperinfo instead of di. A brainfart, surely. This
bug went unnoticed for all this time because the pointer is only
used by buf_write() when it can write a completely filled buffer
to the dump device. This depends on the number of memory chunks
that needs to be dumped. This has apparently been low enough that
it has never happened up until this point.

Allow kernel dumps to be aborted with ctrl-C.

Cast dumpsize to long long to match printf format.

Dotting the i-s:
o Use chunk instead of region when we talk about a memory range.
Region can be confused with region register and we already
call it chunk in machdep.c
o Update the twiddle every 16MB

Fix a braino in the alignment of the segment contents after dumping
the program headers. As a result of this, dumplo was advanced too
much causing the end of the dump and most notably the trailing
dump header to be written beyond the end of the the dump medium.

Make the kernel dump header endianness invariant by always dumping
in dump byte order (=network byte order). Swap blocksize and dumptime
to avoid extraneous padding on 64-bit architectures. Use CTASSERT
instead of runtime checks to make sure the header is 512 bytes large.
Various style(9) fixes.

Reviewed by: phk, bde, mike

Use a twiddle to show that we're busy dumping. The initial code
emitted the total number of pages it still had to dump prior to
dumping a block of up to 16 pages. For a 128MB region this would
result in 8M number of printf()s. Barf!

The problem in general is that memory typically has one really
big region and a number of "scattered" smaller regions. Some may
even be just a few pages. The twiddle works best for now, but
it doesn't really give a good progress indication for the large
regions. Those are the cases where you definitely want good PI
to avoid having the user turn into a twiddle :-)

Initial implementation of the ia64 kernel dumper. The dumper
constructs an ELF image, consisting of the ELF header, for
each memory region a program header, followed by the memory
contents for each region. It does blocked I/O for the headers
as they are typically smaller than DEV_BSIZE.