This was really too big of a commit even if everything worked, but there
are multiple new issues introduced in the one huge commit, so it's not
worth keeping this until it's fixed.

I'll work on splitting this up into logical chunks and introduce them one
at a time over the next week or two.

Approved by:	sbruno (mentor)
Sponsored by:	Limelight Networks

Reviewed by:	emaste
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D12384

When -a is specified, the name and value of all system or path
configuration values is reported to standard output.

Reviewed by:	kib (earlier version)
MFC after:	1 week
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D12373

To optimize the case of ping-ponging between two buffers, the DDP code
caches the last two buffers used keeping the pages wired and page pods
stored in the NIC's RAM.  If a new aio_read() request uses one of the
same buffers, then the work of holding pages, etc. can be avoided.
However, the starting virtual address of an aio buffer was not saved,
only the page count, length, and initial page offset.  Thus, an
aio_read() request could match a different buffer in the address
space.  (Earlier during development vm_fault_hold_quick_pages() was
always called and the vm_page_t values were compared, but that was
eventually removed without being adequately replaced.)  Fix by storing
the starting virtual address and comparing that (along with other
fields) to determine if a buffer can be reused.

MFC after:	3 days
Sponsored by:	Chelsio Communications

Sponsored by:	Netflix

Sponsored by:	Netflix, Inc.

Don't call cam_iosched_trim_done or cam_iosched_submit_trim for nda
since its hardware can handle almost an arbitrary number of TRIMs and
we don't have to be careful to only ever do one.

Sponsored by: Netflix

It's intended only for those situations where the periph driver
ones to limit the number of trims active to one and only one.
Also update comments on associated functions.

Sponsored by: Netflix

Reviewed by:	allanjude
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D12339

After r308212 Capsicum permits .. lookups in capability mode, as long as
path component traversal does not escape the directory corresponding to
the provided file descriptor.

We should add a description of the vfs.lookup_cap_dotdot and
vfs.lookup_cap_dotdot_nonlocal sysctls, perhaps as a cross-reference to
capsicum(4). I intend to look at that soon.

Reviewed by:	bjk, cem, kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D12343

Approved by:	adrian (mentor)
Differential Revision:	https://reviews.freebsd.org/D12300

- The exit probe was not appropriately filtered to only the known pid so it
  was firing on any random process that would exit rather the only the one
  we cared about.
- The dtest script executes the tst.raise*.exe in the background from
  POSIX sh without jobs control.  POSIX mandates that SIGINT be set to
  SIG_IGN in this case.  The test executable never actually tested that
  SIGINT could be caught despite trying to block and delay the signal.
  So the SIGINT sent from raise() is never actually received since it
  is ignored.  This could be fixed by calling 'trap - INT' from dtest
  before running the executable but I've opted to just use SIGUSR1
  instead in these specific tests rather than adding more logic to
  test that SIGINT is not ignored at startup.

These 2 issues meant that the tests would randomly work but only if a process
coincidentally exited during the test.

Reviewed by:	markj
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon

 * Demote the level of several debug messages to CAM_DEBUG_TRACE
 * Add detection for SDHC cards that can do 1.8V. No voltage switch sequence
   is issued yet;
 * Don't create a separate LUN for each SDIO function. We need just one to make
   pass(4) attach;
 * Remove obsolete mmc_sdio* files. SDIO functionality will be moved into the
   separate device that will manage a new sdio(4) bus;
 * Terminate probing if got no reply to CMD0;
 * Make bcm2835 SDHCI host controller driver compile with 'option MMCCAM'.

Approved by:	imp (mentor)
Differential Revision:	https://reviews.freebsd.org/D12109

free queue mutex lock owning session, same as it was done for the
object termination in r323561.

Reported and tested by:	mjg
Reviewed by:	alc, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

Start the phasing out of TRE by disabling it by default. r317254 introduced
a BSD_GREP_FASTMATCH knob (defaulting to on) for testing of bsdgrep with and
without TRE enabled. More bugs have cropped up since then, and
WITHOUT_BSD_GREP_FASTMATCH has shown in testing to be more stable than its
counterpart.

Approved by:	emaste (mentor)
Differential Revision:	https://reviews.freebsd.org/D12381

Sponsored by:	Netflix

MFC after:	1 week

In theory, all data access errors mean that a member is out of sync
at most.  But they were treated as more serious errors to avoid the
situation where a flaky disk gets repeatedly disconnected, re-synchronized,
reconnected and then disconnected again.

ENXIO is a special error that means that the member disk disappeared,
so it should get the same handling as the GEOM orphaning event.
There is a better chance that when the disk is reconnected, it will be
a good member again.

When ENXIO happens on a read we use the exisiting G_MIRROR_BUMP_SYNCID
mechanism which means that the mirror's syncid is increased as soon
as there is a write to the mirror.  That's because no data has got out
of sync yet, but the problematic memeber is disconnected, so the future
write will make it stale.

When ENXIO happens on a write we use a new G_MIRROR_BUMP_SYNCID_NOW
mechanism which means that we update the mirror metadata as soon as
possible because the problematic memeber is already behind.

Reviewed by:	markj, imp
MFC after:	3 weeks
Differential Revision: https://reviews.freebsd.org/D9463

Reviewed by:	kevans
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D12375

exploration tools documentation:
https://developer.arm.com/products/architecture/a-profile/exploration-tools

Sponsored by:	DARPA, AFRL

The list of files for MK_NTP was incomplete.

PR:		218193
Submitted by:	brnrd
MFC after:	1 week

Reviewed by:	matthew (mentor)
Approved by:	matthew (mentor)
Differential Revision:	https://reviews.freebsd.org/D12372

The bad_session, sglist_error, and process_error sysctl nodes were
returning the value of the pad_error node instead of the appropriate
error counters.

Sponsored by:	Chelsio Communications

Sponsored by:	Netflix, Inc.

NetBSD has the warning level to 5 but that actually triggers -Wcast-qual.

works on other OSes.  Also avoid unnecessary NULL check, free(NULL) is
valid.

Reviewed by:	bjk (man page), hrs, hselasky, ume
Sponsored by:	Mellanox Technologies
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D12354

-s and the -S option.

Sponsored by:		Netflix, Inc.

When a newborn socket moves from incomplete queue to complete
one, we need to obtain the listening socket lock after the child,
which is a wrong order.  The old code did that in potentially
endless loop of mtx_trylock().  The new one does only one attempt
of mtx_trylock(), and in case of failure references listening
socket, unlocks child and locks everything in right order.  In
case if listening socket shuts down during that, just bail out.

Reported & tested by:	Jason Eggleston <jeggleston llnw.com>
Reported & tested by:	Jason Wolfe <jason llnw.com>

kernel. We can register callbacks to perform the required operation on the
saved registers before returning.

This is initially used to work around a bug in old versions of QEMU that
trigger such an exception when reading from an ID register when it should
load z zero value.

I expect this could be used with other exception types, e.g. to emulate
special register access from userland.

Sponsored by:	DARPA, AFRL

No functional changes, just cleanup.

Reviewed by:	allanjude, imp
Differential Revision:	https://reviews.freebsd.org/D12370

Reviewed by:	emaste
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D12371

Clang complains "variable 'dummy' is uninitialized when used here".

Reported by:	Clang
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation

An eventual devd(8) or other component should be able to scan buses and
automatically load drivers that match device ids described in this metadata.

Reviewed by:	imp
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D12364

x86 has two separate (but identical) list of AT_* constants and the
earlier commit to add AT_HWCAP only updated the i386 list.

The core note matches the format and layout of NT_ARM_VFP on Linux.
Debuggers use the AT_HWCAP flags to determine how many VFP registers
are actually used and their format.

Reviewed by:	mmel (earlier version w/o gcore)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D12293

Should have been part of the previous commit to add ptrace operations
for VFP registers.

MFC after:	1 month

Reviewed by:	mmel, kib
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D12294

Future changes will use these functions to fetch and store VFP state for
threads other than curthread.

Reviewed by:	andrew, stevek, Michal Meloun <meloun-miracle-cz>
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D12292