Remove redundant assignment of `p'.

`p' is already initialized with `td->td_proc'. Because td is always
curthread, it is safe to initialize it without any locks.

Found by: LLVM's scan-build

Use NULL in preference to 0 for pointers.

Revert r185891.

In r185891 I removed the newlines from messages written to /dev/console,
because it made startup messages from rc-scripts harder to read. This,
unfortunately, causes the kernel messa

Revert r185891.

In r185891 I removed the newlines from messages written to /dev/console,
because it made startup messages from rc-scripts harder to read. This,
unfortunately, causes the kernel message that is printed after a
non-terminated log message to be concatenated.

This could be fixed, but on short term it's better to just revert the
change.

Reported by: Jaakko Heinonen <jh saunalahti fi>

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Remove added newlines from logged messages written to /dev/console.

The /dev/console device node logs all strings that are written to it.
When the string does not contain a trailing newline, it appe

Remove added newlines from logged messages written to /dev/console.

The /dev/console device node logs all strings that are written to it.
When the string does not contain a trailing newline, it appends one. I
can imagine this was useful a long time ago, but with our current
rc-scripts, it generates a whole bunch of messages that look like:

| Configuring syscons:
| blanktime
| .

By not appending the newlines, the output of `dmesg -a' is now (almost?)
exactly the same as what the user will see on the console device
(syscons, uart).

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integrate from head@185615

Obey signedness flag in %z case.

MFC after: 2 months

Integrate the new MPSAFE TTY layer to the FreeBSD operating system.

The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve

Integrate the new MPSAFE TTY layer to the FreeBSD operating system.

The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.

If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).

The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan

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Instead of doing comparisons using the pcpu area to see if
a thread is an idle thread, just see if it has the IDLETD
flag set. That flag will probably move to the pflags word
as it's permenent and ne

Instead of doing comparisons using the pcpu area to see if
a thread is an idle thread, just see if it has the IDLETD
flag set. That flag will probably move to the pflags word
as it's permenent and never chenges for the life of the
system so it doesn't need locking.

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Flushing the buffer is conditional on actually using the buffer. Oops.

Turn console printf buffering into a kernel option and only on
by default for sun4v where it is absolutely required.

This change moves the buffer from struct pcpu to the stack to avoid
using the cri

Turn console printf buffering into a kernel option and only on
by default for sun4v where it is absolutely required.

This change moves the buffer from struct pcpu to the stack to avoid
using the critical section which created a LOR in a couple of cases
due to interaction with the tty code and kqueue. The LOR can't be
fixed with the critical section and the pcpu buffer can't be used
without the critical section.

Putting the buffer on the stack was my initial solution, but it was
pointed out that the stress on the stack might cause problems
depending on the call path. We don't have a way of creating tests
for those possible cases, so it's best to leave this as an option
for the time being. In time we may get enough data to enable this
option more generally.

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Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

Sponsored by: nCircle

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>

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Add a cnputs() function to write a string to the console with
a lock to prevent interspersed strings written from different CPUs
at the same time.

To avoid putting a buffer on the stack or having to

Add a cnputs() function to write a string to the console with
a lock to prevent interspersed strings written from different CPUs
at the same time.

To avoid putting a buffer on the stack or having to malloc one,
space is incorporated in the per-cpu structure. The buffer
size if 128 bytes; chosen because it's the next power of 2 size
up from 80 characters.

String writes to the console are buffered up the end of the line
or until the buffer fills. Then the buffer is flushed to all
console devices.

Existing low level console output via cnputc() is unaffected by
this change. ithread calls to log() are also unaffected to avoid
blocking those threads.

A minor change to the behaviour in a panic situation is that
console output will still be buffered, but won't be written to
a tty as before. This should prevent interspersed panic output
as a number of CPUs panic before we end up single threaded
running ddb.

Reviewed by: scottl, jhb
MFC after: 2 weeks

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Declare security and security.bsd sysctl hierarchies in sysctl.h along
with other commonly used sysctl name spaces, rather than declaring them
all over the place.

MFC after: 1 month
Sponsored by: nC

Declare security and security.bsd sysctl hierarchies in sysctl.h along
with other commonly used sysctl name spaces, rather than declaring them
all over the place.

MFC after: 1 month
Sponsored by: nCircle Network Security, Inc.

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Simplify the pager support in DDB. Allowing different db commands to
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit

Simplify the pager support in DDB. Allowing different db commands to
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer). So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt. Also, now that it's easy to do so,
enable paging by default for all ddb commands. Any command that wishes to
honor the quit flag can do so by checking db_pager_quit. Note that the
pager can also be effectively disabled by setting $lines to 0.

Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
terminates early.
- 'show intr' now actually checks the quit flag and terminates early.

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Implement printf 'X' conversion for both libstand and kernel.

Always print a newline char at the end of the line.

Acquire Giant in uprintf() and tprintf() rather than asserting it. In
the vast majority of cases, these functions are called without mutexes
held, meaning that in all but two cases, there will be no

Acquire Giant in uprintf() and tprintf() rather than asserting it. In
the vast majority of cases, these functions are called without mutexes
held, meaning that in all but two cases, there will be no ordering
issues with doing this, and it will eliminate the need for changes in
the caller. In two cases, mutexes are held, so Giant must be acquired
before those mutexes such that uprintf() and tprintf() recurse Giant
rather than generating a lock order reversal.

Suggested by: bde

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Correct an incorrect comment from the dawn of time: neither tprintf()
nor uprintf() is believed to perform tsleep() or msleep() as written,
as ttycheckoutq() is called with '0' as its sleep argument.

Correct an incorrect comment from the dawn of time: neither tprintf()
nor uprintf() is believed to perform tsleep() or msleep() as written,
as ttycheckoutq() is called with '0' as its sleep argument.

Remove recently added WITNESS warnings for sleep as the comment was
incorrect. This should silence a warning from the nfs_timer() code.

Discussed with: bde

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Add GIANT_REQUIRED and WITNESS sleep warnings to uprintf() and tprintf(),
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).

Modify all consumer

Add GIANT_REQUIRED and WITNESS sleep warnings to uprintf() and tprintf(),
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).

Modify all consumers of uprintf() and tprintf() to hold Giant around
calls into these functions. In most cases, this means adding an
acquisition of Giant immediately around the function. In some cases
(nfs_timer()), it means acquiring Giant higher up in the callout.

With these changes, UFS no longer panics on SMP when either blocks are
exhausted or inodes are exhausted under load due to races in the tty
code when running without Giant.

NB: Some reduction in calls to uprintf() in the svr4 code is probably
desirable.

NB: In the case of nfs_timer(), calling uprintf() while holding a mutex,
or even in a callout at all, is a bad idea, and will generate warnings
and potential upset. This needs to be fixed, but was a problem before
this change.

NB: uprintf()/tprintf() sleeping is generally a bad ideas, as is having
non-MPSAFE tty code.

MFC after: 1 week

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When padding with zero, do pad after prefixes rather than padding
before prefixes.

Use cases:
printf("%05d", -42); --> "00-42" (should be "-0042")
printf("%#05x", 12); --> "000xc" (sho

When padding with zero, do pad after prefixes rather than padding
before prefixes.

Use cases:
printf("%05d", -42); --> "00-42" (should be "-0042")
printf("%#05x", 12); --> "000xc" (should be "0x00c")

Submitted by: Oliver Fromme
PR: kern/85520
MFC After: 1 week

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If we ignore an unknown % sequence, we must stop interpreting the
remaining % arguments because the varargs are now out of sync and
there is a risk that we might for instance dereference an integer
i

If we ignore an unknown % sequence, we must stop interpreting the
remaining % arguments because the varargs are now out of sync and
there is a risk that we might for instance dereference an integer
in a %s argument.

Sponsored by: Napatech.com

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Make "show msgbuf" use the pager instead of blasting the whole thing out.

MFC after: 3 days

Constify hexdump() harder.

In stange circumstances we may end up being the last reference to a
session in tprintf(). SESSRELE() needs to properly dispose of the
sessions mutex.

Add sessrele() which does the proper cleanup a

In stange circumstances we may end up being the last reference to a
session in tprintf(). SESSRELE() needs to properly dispose of the
sessions mutex.

Add sessrele() which does the proper cleanup and have SESSRELE() call it.

Use SESSRELE also in pgdelete().

Found by: Coverity (ID:526)

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Update for the KDB framework:
o Check kdb_active instead of db_active and do so unconditionally.