sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

smb_iod_main: eliminate write only variable error

Sponsored by: Netflix

net: clean up empty lines in .c and .h files

Make timespecadd(3) and friends public

The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have grown at least 28 syscalls that use timespecs in some
way, leading many programs both inside and outside of the base system to
redefine those macros. It's better just to make the definitions public.

Our kernel currently defines two-argument versions of timespecadd and
timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define
three-argument versions. Solaris also defines a three-argument version, but
only in its kernel. This revision changes our definition to match the
common three-argument version.

Bump _FreeBSD_version due to the breaking KPI change.

Discussed with: cem, jilles, ian, bde
Differential Revision: https://reviews.freebsd.org/D14725

sys: general 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.

No functional change intended.

The problem report was for a crash that happened when smbfs was
trying to do a mount. Given the backtrace,
it appears that the crash occurred when smb_vc_create() failed and then
called smb_vc_put() with vcp->vc_iod == NULL. smb_vc_put() subsequently
called smb_vc_disconnect() with vcp->vc_iod == NULL, causing the crash.
This patch adds a check for vcp->vc_iod != NULL in smb_vc_disconnect() to
avoid the crash. It also fixes the case in smb_vc_create() where
kproc_create() fails so that it destroys the mutexes and sets
vcp->vc_iod == NULL before free()'ing the iod structure.
The person who reported the PR tested the patch, but was not able
to reproduce the crash with or without the patch.

PR: 201912
Reviewed by: jhb
MFC after: 2 weeks

When the smbfs iod thread (smb_iod_thread()) is shutting down, smb_iod_destroy()
would call smb_iod_request(). This call could return as soon as the
wakeup(evp) in smb_iod_main() call is done and then could destroy
the mutexes. This caused a race with the rest of smb_iod_main()s
use of these mutexes.
A crash reported on freebsd-stable@ by Christian Kratzer was
diagnosed as a use of one of these mutexes after it was destroyed.
This patch moves destruction of the mutexes from smb_iod_destroy()
to the end of smb_iod_thread(), so that they aren't destroyed before
the thread is done with them. Christian comfirmed that the patch
stopped the crashes from happening.

Reported by: ck-lists@cksoft.de (Christian Kratzer)
Tested by: ck-lists@cksoft.de (Christian Kratzer)
Diagnosed by: jhb
Reviewed by: jhb
MFC after: 2 weeks

Remove redundant unlock.

This code was removed from the opensolaris and darwin's
netsmb implementations, in DfBSD it also has been disabled.

PR: 36566, 87859, 139407, 161579, 175557, 178412, 186652
MFC after: 2 weeks
Sponsored by: Yandex LLC

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Switch to our preferred 2-clause BSD license.

Approved by: bp

- Import the HEAD csup code which is the basis for the cvsmode work.

Really, smb_iod_main() is not totally MPSAFE, so just acquire and drop
Giant around it in order to assume MPSAFETY.

Reported by: jhb, rwatson
Pointy hat to: attilio

Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by: arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.

Remove a spourious Giant acquisition.
The code seems pretty MPSAFE and Giant is held over kproc_exit() which
at lowel calls exit1(). exit1() requires Giant to be unowned so this
opens a window for races.

Reported by: Bryan Venteicher <bryanv at daemoninthecloset dot org>
Tested by: Bryan Venteicher <bryanv at daemoninthecloset dot org>

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

Fix misalignment bugs caused by invalid type casts of pointers
returned by md_reserve(). Space reserved by mb_reserve() is
byte aligned and need to be used in conjunction with le16enc()
and le32enc().

Tested on: ia64

/* -> /*- for license, minor formatting changes

Add support for SMB request signing, which prevents "man in the middle"
attacks and is required to connect to Windows 2003 servers in their
default configuration. This adds an extra field to the SMB header
containing the truncated 64-bit MD5 digest of a key (a function of the
user's password and the server's authentication challenge), an implicit
sequence number, and the message data itself. As signing each message
imposes a significant performance penalty, we only enable it if the
server will not let us connect without it; this should eventually become
an option to mount_smbfs.

Rewrite the code that uses the try/catch paradigm implemented by
goto and abstracted by the itry, ithrow and icatch macros (among
others). The problem with this code is that it doesn't compile on
ia64. The compiler is sufficiently confused that it inserts a call
to __ia64_save_stack_nonlock(). This is a magic function that saves
enough of the stack to allow for non-local gotos, such as would be
the case for nested functions. Since it's not a compiler defined
function, it needs a runtime implementation. This we have not in a
standalone compilation as is the kernel.

There's no indication that the compiler is not confused on other
platforms. It's likely that saving the stack in those cases is
trivial enough that the compiler doesn't need to off-load the
complexity to a runtime function.

The code is believed to be correctly translated, but has not been
tested. The overall structure remained the same, except that it's
made explicit. The macros that implement the try/catch construct
have been removed to avoid reintroduction of their use. It's not
a good idea.

In general the rewritten code is slightly more optimal in that it
doesn't need as much stack space and generally is smaller in size.

Found by: LINT

Avoid dereferencing the thread pointer in smb_iod_addrq() if it's NULL.
Fixes mdconfig -t vnode on smbfs: mdsetcred()'s "horrible kludge"
calls into smbfs VOP_READ with a NULL uio_td.

Use __FBSDID().

- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

Remove the hto(be|le)[slq] and (be|le)toh[slq] macros defined in
_KERNEL scope from "src/sys/sys/mchain.h".

Replace each occurrence of the above in _KERNEL scope with the
appropriate macro from the set of hto(be|le)(16|32|64) and
(be|le)toh(16|32|64) from "src/sys/sys/endian.h".

Tested by: tjr
Requested by: comment marked with XXX

Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create. Passing the
value 0 prevents the alternate kstack from being created. Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by: jake, peter, jhb

Fix trivial warning:
smb_iod.c:560: deprecated use of label at end of compound statement

Move the new byte order function prototypes from <sys/param.h> to
<sys/endian.h>. This puts us in line with NetBSD and OpenBSD.

- Replace M_WAIT with M_TRYWAIT since the M_WAIT flag is deprecated.

Spotted by: bde

Pull netsmb requester from the pre-KSE world. This update mostly based
on the patches submitted by Max Khon <fjoe@iclub.nsu.ru>

Use local wrappers instead of direct calls to mtx_destroy().

Obtained from: Mac OS X
MFC after: 1 week

Import kernel part of SMB/CIFS requester.
Add smbfs(CIFS) filesystem.

Userland part will be in the ports tree for a while.

Obtained from: smbfs-1.3.7-dev package.