MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

devfs: rework si_usecount to track opens

This removes a lot of special casing from the VFS layer.

Reviewed by: kib (previous version)
Tested by: pho (previous version)
Differential Revision: https:

devfs: rework si_usecount to track opens

This removes a lot of special casing from the VFS layer.

Reviewed by: kib (previous version)
Tested by: pho (previous version)
Differential Revision: https://reviews.freebsd.org/D25612

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Assign process group of the TTY under the "proctree_lock".

This fixes a race where concurrent calls to doenterpgrp() and
leavepgrp() while TIOCSCTTY is executing may result in tp->t_pgrp
changing va

Assign process group of the TTY under the "proctree_lock".

This fixes a race where concurrent calls to doenterpgrp() and
leavepgrp() while TIOCSCTTY is executing may result in tp->t_pgrp
changing value so that tty_rel_pgrp() misses clearing it to NULL. For
more details refer to the use of pgdelete() in the kernel.

No functional change intended.

Panic backtrace:
__mtx_lock_sleep() # page fault due to using destroyed mutex
tty_signal_pgrp()
tty_ioctl()
ptsdev_ioctl()
kern_ioctl()
sys_ioctl()
amd64_syscall()

MFC after: 1 week
Sponsored by: Mellanox Technologies

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tty: convert tty_lock_assert to tty_assert_locked to hide lock type

A later change, currently being iterated on in D24459, will in-fact change
the lock type to an sx so that TTY drivers can sleep on

tty: convert tty_lock_assert to tty_assert_locked to hide lock type

A later change, currently being iterated on in D24459, will in-fact change
the lock type to an sx so that TTY drivers can sleep on it if they need to.
Committing this ahead of time to make the review in question a little more
palatable.

tty_lock_assert() is unfortunately still needed for now in two places to
make sure that the tty lock has not been recursed upon, for those scenarios
where it's supplied by the TTY driver and possibly a mutex that is allowed
to recurse.

Suggested by: markj

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Merge ^/head r357408 through r357661.

fd: remove the seq argument from fget_unlocked

It is almost always NULL.

vfs: introduce v_irflag and make v_type smaller

The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
part

vfs: introduce v_irflag and make v_type smaller

The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by: kib, jeff
Differential Revision: https://reviews.freebsd.org/D22715

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tty: implement TIOCNOTTY

Generally, it's preferred that an application fork/setsid if it doesn't want
to keep its controlling TTY, but it could be that a debugger is trying to
steal it instead -- so

tty: implement TIOCNOTTY

Generally, it's preferred that an application fork/setsid if it doesn't want
to keep its controlling TTY, but it could be that a debugger is trying to
steal it instead -- so it would hook in, drop the controlling TTY, then do
some magic to set things up again. In this case, TIOCNOTTY is quite handy
and still respected by at least OpenBSD, NetBSD, and Linux as far as I can
tell.

I've dropped the note about obsoletion, as I intend to support TIOCNOTTY as
long as it doesn't impose a major burden.

Reviewed by: bcr (manpages), kib
Differential Revision: https://reviews.freebsd.org/D22572

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tty_rel_gone: add locking assertion

We already assert the lock is held later during tty_rel_free(), but it is
arguably good form to clarify locking expectations here as well at the
top-level that ot

tty_rel_gone: add locking assertion

We already assert the lock is held later during tty_rel_free(), but it is
arguably good form to clarify locking expectations here as well at the
top-level that other drivers use.

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MFHead @r350386

Sponsored by: The FreeBSD Foundation

Defer funsetown() calls for a TTY to tty_rel_free().

We were otherwise failing to call funsetown() for some descriptors
associated with a tty, such as pts descriptors. Then, if the
descriptor is cl

Defer funsetown() calls for a TTY to tty_rel_free().

We were otherwise failing to call funsetown() for some descriptors
associated with a tty, such as pts descriptors. Then, if the
descriptor is closed before the owner exits, we may get memory
corruption.

Reported by: syzbot+c9b6206303bf47bac87e@syzkaller.appspotmail.com
Reviewed by: ed
MFC after: 3 days
Sponsored by: The FreeBSD Foundation

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MFHead @349234

Sponsored by: The FreeBSD Foundation

Some devices take undesired actions when RTS and DTR are
asserted. Some development boards for example will reset on DTR,
and some radio interfaces will transmit on RTS.

This patch allows "stty -f /

Some devices take undesired actions when RTS and DTR are
asserted. Some development boards for example will reset on DTR,
and some radio interfaces will transmit on RTS.

This patch allows "stty -f /dev/ttyu9.init -rtsdtr" to prevent
RTS and DTR from being asserted on open(), allowing these devices
to be used without problems.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D20031

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Merge ^/head r340126 through r340212.

Avoid fixing the tty_info() buffer size in tty.h.

Different compilation units may otherwise get a different view of the
layout of struct tty depending on whether they include opt_printf.h.
This caus

Avoid fixing the tty_info() buffer size in tty.h.

Different compilation units may otherwise get a different view of the
layout of struct tty depending on whether they include opt_printf.h.
This caused a blowup in the number of types defined in the kernel's
CTF file after r339468; thanks to dim@ for bisecting down to that
revision.

PR: 232675
Reported by: dim
Reviewed by: cem (previous version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17877

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Revert r335995 due to accidental changes snuck in

kern_environment: use any provided environments, evict hintmode/envmode

At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel c

kern_environment: use any provided environments, evict hintmode/envmode

At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel config(5) and the
static versions are mutually exclusive with loader(8)-provided environment.
hintmode *can* be reconfigured later to pull from the dynamic environment,
thus taking advantage of the loader(8) or post-kmem environment setting.

This changeset fixes both problems at once to move us from a semi-confusing
state to a consistent state: if an environment file, hints file, or
loader(8) environment are provided, we use them in a well-known order of
precedence:

- loader(8) environment
- static environment
- static hints file

Once the dynamic environment is setup this becomes a moot point. The
loader(8) and static environments are merged (respecting the above order of
precedence), and the static hints are merged in on an as-needed basis after
the dynamic environment has been setup.

Hints lookup are changed to respect all of the above. Before the dynamic
environment is setup, lookups use the above-mentioned order and fallback to
the next environment if a matching hint is not found. Once the dynamic
environment is setup, that is used on its own since it captures all of the
above information plus any dynamic kenv settings that came up later in boot.

The following tangentially related changes were made to res_find:

- A hintp cookie is now passed in so that related searches continue using
the chain of environments (or dynamic environment) without relying on
global state
- All three environments will be searched if they actually have valid hints
to use, rather than just choosing the first environment that actually had
a hint and rolling with that only

The hintmode sysctl has been ripped out. static_{env,hints}.disabled are
still honored and will disable their respective environments from being used
for hint lookups and from being merged into the dynamic environment, as
expected.

MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15953

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Move most of the contents of opt_compat.h to opt_global.h.

opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
close

Move most of the contents of opt_compat.h to opt_global.h.

opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.

Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.

Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.

Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941

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sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone

sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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Merge ^/head r318658 through r318963.

Commit the 64-bit inode project.

Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_na

Commit the 64-bit inode project.

Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment. Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks. Unfortunately, not everything can be
fixed, especially outside the base system. For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING. Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver. Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by: The FreeBSD Foundation (emaste, kib)
Differential revision: https://reviews.freebsd.org/D10439

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Merge ^/head r311940 through r312200.

Correct the comments about how much buffer is allocated.

Check tty_gone() after allocating IO buffers. The tty lock has to be
dropped then reacquired due to using M_WAITOK, which opens a window in
which the tty device can disappear. Check for this and re

Check tty_gone() after allocating IO buffers. The tty lock has to be
dropped then reacquired due to using M_WAITOK, which opens a window in
which the tty device can disappear. Check for this and return ENXIO
back up the call chain so that callers can cope.

This closes a race where TF_GONE would get set while buffers were being
allocated as part of ttydev_open(), causing a subsequent call to
ttydevsw_modem() later in ttydev_open() to assert.

Reported by: pho
Reviewed by: kib

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Restructure the tty_drain loop so that device-busy is checked one more time
after tty_timedwait() returns an error only if the error is EWOULDBLOCK;
other errors cause an immediate return. This fixe

Restructure the tty_drain loop so that device-busy is checked one more time
after tty_timedwait() returns an error only if the error is EWOULDBLOCK;
other errors cause an immediate return. This fixes the case of the tty
disappearing while in tty_drain().

Reported by: pho

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