It has been reported that on some AWS instances VCPUOP_send_nmi
returns -38 (ENOSYS). The hypercall is only available for HVM guests
in Xen 4.7 and newer. Add a fallback to use the native NMI sending
procedure when VCPUOP_send_nmi is not available, so that the NMI is
not lost.

Reported and Tested by: avg
MFC after: 1 week
Fixes: b2802351 ('xen: fix dispatching of NMIs')
Sponsored by: Citrix Systems R&D

PR:	261136
Reported by:	Daniel O'Connor
MFC after:	2 weeks

Reviewed by:	cem, avg
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D33794

Reviewed by:	kib
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D33792

Reviewed by:	kib
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D33790

From a user point of view, this makes ^T work out of the box.

Reviewed By:	debdrup (man page)
Sponsored By:	EPSRC
Differential Revision:	https://reviews.freebsd.org/D33842

Printing %p does not need the 0x prefix and while here mark the
ieee80211_node_table argument unused given we do not need it in the
current incarnation of the function.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days

Since trie configuration remains invariant during each DXR instance
lifetime, instead of shifting and masking lookup keys by values
computed at runtime, compile upfront several dxr_lookup()
configurations with hardcoded shift / mask constants, and choose the
apropriate lookup function version after each DXR instance rebuild.

In synthetic tests this yields small but measurable (5-10%) lookup
throughput improvement, depending on FIB size and  prefix patterns.

MFC after:	3 days

enum ieee80211_channel_flags are used as bit fields and not as 1..n.
Correct the values using BIT(n).

This is also hoped to fix problems with 7260 cards which come up and
panic due to an empty channel list as all channels are set disabled [1].
It will hopefully also fix the one or other oddity.

Reported by:	ambrisko, Mike Tancsa (mike sentex.net) [1]
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days

Reported by: Glenn Tam

It was obtained from musl, and is MIT licensed.

MFC after:	3 days
Sponsored by:	The FreeBSD Foundation

Obtained from:	musl c53e9b239418

MFC after:	3 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")

The new lock introduced in 5f5e32f1 needs to be initialised early so
that it can be safely destroyed if we error out.

Reported-by: syzbot+d76113e9a4ae0c0fcac2@syzkaller.appspotmail.com
MFC after:	3 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")

If only one file is passed, this reads the terminating NULL and so
prints (null). If multiple files are passed then this always prints the
second file, which may or may not exist (and will be particularly
confusing if it does exist since the output will include the dump of the
second file).

MFC after:	1 week

Before commit 3cec5c77 buf_daemon() went to longer 1s sleep if
numdirtybuffers <= lodirtybuffers.  After that commit new condition
!BIT_EMPTY(BUF_DOMAINS, &bdlodirty) got opposite -- true when one
or more more domains is above lodirtybuffers.  As result, on freshly
booted system with no dirty buffers buf_daemon() wakes up 10 times
per second and probably only 1 time per second when there is actual
work to do.

MFC after:	1 week
Reviewed by:	kib, markj
Tested by:	pho
Differential revision:	https://reviews.freebsd.org/D33890

A case of undefined behavior in __fread() has been detected by UBSAN
and reported by Mark Millard:

/usr/main-src/lib/libc/stdio/fread.c:133:10: runtime error: applying
zero offset to null pointer
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior in
/usr/main-src/lib/libc/stdio/fread.c:133:10

While being benign (the NULL pointer is later passed to memcpy() with
a length argument of 0), this issue causes in the order of 600 Kyua
test cases to fail on systems running a world built with WITH_UBSAN
and WITH_ASAN.

The undefined behavior can be prevented by skipping operations that
have no effect for r == 0. Mark Millard has suggested to only skip
this code segment if fp->_p == NULL, but I have verified that for the
case of r == 0 no further argument checking is performed on the
addresses passed to memcpy() and thus no bugs are hidden from the
sanitizers due to the simpler condition chosen.

Reported by:	Mark Millard (marklmi@yahoo.com)
Tested by:	Mark Millard (marklmi@yahoo.com)
Differential Revision:	https://reviews.freebsd.org/D33903
MFC after:	2 weeks

Correct data types related to delivery traffic indication map (DTIM)/
timing synchronization function (TSF) and implement/refine their
handling.  This information is used/needed by iwlwifi to set a station
as associated.  This will hopefully avoid more "no beacon heard"
time event failures.

The recording of the Linux specific sync_device_ts is done in the
receive path for now in case we do have the right information
available.  I need to investigate as to how-much it may make sense
to also migrate it into net80211 in the future depending on the
usage in other drivers (or how we did handle this in the past in
natively ported versions, e.g. iwm).

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days

Rather than just bouncing back to SCAN bounce to INIT on connection
loss.  This is should be refined in the future as the comment already
indicates but we need to tie two different worlds together.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days

We do not include sys/rman.h and so machine/resource.h ends up not being
included by the time pci_private.h is included. This means PCI_RES_BUS
is never defined, and so the sc_bus member of pci_softc is not present
when compiling ofw_pci, resulting in the wrong softc size being passed
to DEFINE_CLASS_1 and thus any attempts by pci(4) to access that member
are out-of-bounds reads or writes.

This is pretty fragile; arguably pci_private.h should be including
sys/rman.h, but this is the minimal needed change to fix the bug whilst
maintaining the status quo.

Found by:	CHERI
Reported by:	andrew

Some VM systems announce the frequency of the local APIC via the
CPUID leaf 0x40000010.  Using this allows us to boot slightly
faster by avoiding the need for timer calibration.

Reviewed by:	markj
Sponsored by:	https://www.patreon.com/cperciva

While this CPUID leaf was originally only used by VMWare, other
hypervisors now also use it to announce the TSC frequency to guests.

This speeds up the boot process by 100 ms in EC2 and other systems,
by allowing the early calibration DELAY to be skipped.

Reviewed by:	markj
Sponsored by:	https://www.patreon.com/cperciva

This allows us to set tsc_is_invariant and select appropriately
fenced versions of RDTSC based on the CPU type.

Reviewed by:	markj
Sponsored by:	https://www.patreon.com/cperciva

The default sysctl context setup by newbus for a device is eventually
freed by device_sysctl_fini, which runs after the device driver's detach
routine.  sysctl nodes associated with this context must not use any
resources (like driver locks, hardware access, counters, etc.) that are
released by driver detach.

There are a lot of sysctl nodes like this in cxgbe(4) and the fix is to
hang them off a context that is explicitly freed by the driver before it
releases any resource that might be used by a sysctl.

This fixes panics when running "sysctl dev.t6nex dev.cc" in a tight loop
and loading/unloading the driver in parallel.

Reported by:	Suhas Lokesha
MFC after:	1 week
Sponsored by:	Chelsio Communications

Fixes:		ef790cc7 ("hdaa: update pin patch configurations")
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33900

Since both scsi_xpt and ata_xpt use the same name for the softc, this
can lead to problems in gdb. Avoid the issue by renaming the ata
probe_softc to aprobe_softc as has been done for the aprobe in
0f280cbd. This was overlooked at the time.

Sponsored by:		Netflix
MFC After:		2 weeks

VM's have little control over CPU speed, don't make matters worse
by constantly spaming console.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D33902

Before this change on every open da(4) driver read all mode pages to
use only one bit.  It was done so to not depend on the list of pages
supported by the disk.  But I've found that at least for SATL of LSI/
Broadcom HBAs with WD HDDs Power Condition mode page reading may take
significant amount of time, much more than any other mode page, that
visibly increased disk retaste time by GEOM.

Address that by using data returned by the first MODE SENSE request
to limit the following ones to only one (the first for now) mode page.

With the change simultaneous retaste of 39 SATA disks takes about 2.5s
instead of more than 4s before, and I no longer see "dareprobe" status
on GEOM event thread.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.

Allow projects based on the FreeBSD tree to append to _PRIVATELIBS
and _INTERNALLIBS by simply maintaining their own lists of
LOCAL_PRIVATELIBS and LOCAL_INTERNALLIBS, respectively.

Reviewed by:	bdrewery
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D33901

In iflib_device_register(), the CTX_LOCK is acquired first and then
IFNET_WLOCK is acquired by ether_ifattach(). However, in netmap_hw_reg()
we do the opposite: IFNET_RLOCK is acquired first, and then CTX_LOCK
is acquired by iflib_netmap_register(). Fix this LOR issue by wrapping
the CTX_LOCK/UNLOCK calls in iflib_device_register with an additional
IFNET_WLOCK. This is safe since the IFNET_WLOCK is recursive.

MFC after:	1 month

This tiny change to the example makes devd capable of reacting to carp
status change events on VLAN interfaces.

Reported by:	Thomas Steen Rasmussen (tykling) <thomas at gibfest.dk>

Buckets in an SMR-enabled zone can legitimately be tagged with
SMR_SEQ_INVALID.  This effectively means that the zone destructor (if
any) was invoked on all items in the bucket, and the contained memory is
safe to reuse.  If the first bucket in the full bucket list was tagged
this way, UMA would unnecessarily poll per-CPU state before attempting
to fetch a full bucket from the list.

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation

Previously we'd always print "out of swap space."  This can be
misleading, as there are other reasons an OOM kill can be triggered.  In
particular, it's entirely possible to trigger an OOM kill on a system
with plenty of free swap space.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33810

These configuration options were removed in commit dfe13344.

Some forthcoming work will update the UMA man page to describe its
current behaviour on NUMA systems.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation

The test tries to connect a socket to a closed port at 127.0.0.1.  It
sets O_NONBLOCK on the socket first and expects to get EINPROGRESS from
connect(2), but this is not guaranteed, ECONNREFUSED is possible.
Handle both cases, and re-enable the test.

PR:		240621
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation

The stack gap implementation is disabled by default now, so the test
passes.

This reverts commit dad71022.

PR:		259969
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation

If an emulation uses those functions instead of set_config_value_node
or set_config_value, it allows the config values to get
overwritten. Introducing new functions is much more readable than
if else statements in the emulation code.

Reviewed by:	khng
MFC after:	2 weeks
Sponsored by:	Beckhoff Automation GmbH & Co. KG
Differential Revision:	https://reviews.freebsd.org/D33770