Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix bug in r253719: fix command line watchdog disable.

r253719 disallowed watchdog(8) from disabling the watchdog
by breaking the ability to pass 0 as a timeout arg. Fix this.

Apply a casting sledgehammer.

Submitted by: dhw

Fix printf of seconds for systems where time_t is 64 bits.

mdoc and language improvements.

Provide some examples for watchdogd usage.

Fix watchdog pretimeout.

The original API calls for pow2ns, however the new APIs from
Linux call for seconds.

We need to be able to convert to/from 2^Nns to seconds in both
userland and kernel to fix this and properly compare units.

Mark the act_tbl static/const.

This table is only used within this source file and is only accessed
read-only.

MFC after: 1 week

Invert the meaning of -S (added in r247405) and document its meaning. Also,
don't carp about the watchdog command taking too long until after the
watchdog has been patted, and don't carp via warnx(3) unless -S is set
since syslog(3) already logs to standard error otherwise.

Discussed with: alfred
Reviewed by: alfred
Approved by: emaste (co-mentor)

Remove EOL whitespace.

mdoc: begin sentence on new line.

watchdogd(8) and watchdog(4) enhancements.

The following support was added to watchdog(4):
- Support to query the outstanding timeout.
- Support to set a software pre-timeout function watchdog with an 'action'
- Support to set a software only watchdog with a configurable 'action'

'action' can be a mask specifying a single operation or a combination of:
log(9), printf(9), panic(9) and/or kdb_enter(9).

Support the following in watchdogged:
- Support to utilize the new additions to watchdog(4).
- Support to warn if a watchdog script runs for too long.
- Support for "dry run" where we do not actually arm the watchdog,
but only report on our timing.

Sponsored by: iXsystems, Inc.
MFC after: 1 month

Revert accidental regression to previous misspelling.

Approved by: cognet (mentor)

Reduce watchdogd's memory footprint when running daemonized.

This uses the recently-added jemalloc(3) feature of setting the lg_chunk
tuning option to zero to request that memory be allocated in the smallest
chunks possible. Without this option, the default is to initally map 8MB,
and then the mlockall() call wires that entire allocation even though the
program only uses a few Kbytes of it at runtime.

PR: bin/173332
Approved by: cognet (mentor)

Spelling: exitting -> exiting

MFC after: 2 weeks

Replace log(3) with flsll(3) for watchdogd(8) and drop libm dependency.

MFC after: 2 weeks

- It's also need to lock current memory.

Approved by: kib (mentor)
MFC after: 1 week

- Don't allow watchdogd(8) to be swapped out.
On machines with huge amount of swap and high IO activity,
watchdogd(8) may wait for a swap memory longer than timeout and
sometimes fires.

Approved by: kib (mentor)
MFC after: 1 week

Protect the watchdog daemon against swap OOM killer. This is similar to
SVN r199804 which added protection to sshd, cron, syslogd, and inetd.

Staticify local variables.

While I'm there also add a 'static' keyword for a function to make it
consistent with prototype.

Reviewed by: phk
MFC after: 3 months

The last big commit: let usr.sbin/ use WARNS=6 by default.

ANSIfy almost all applications that use WARNS=6.

I was considering committing all these patches one by one, but as
discussed with brooks@, there is no need to do this. If we ever
need/want to merge these changes back, it is still possible to do this
per application.

Don't hide an error if the initial attempt to program a watchdog from
within watchdogd(8) fails. This is also consistent with watchdog(8).

Don't exit from watchdogd on receiving a signal if we cannot stop the watchdog.
That'll require -KILL. This avoids resetting your system on one of the
watchdogs that you cannot disable.

Markup fixes.

Document that the default timeout is 16 seconds

Fix usage().

Submitted by: Adrian Steinmann <ast@marabu.ch>

Report any errors we might see when disabling the watchdog.

Complain about extra arguments so people don't get surprised
if they type "watchdog 0"

Pidfiles should be created with permission preventing users from opening
them for reading. When user can open file for reading, he can also
flock(2) it, which can lead to confusions.

Pointed out by: green

Use pidfile(3) in watchdogd(8).

When disarming a watchdog by using an interval of WD_TO_NEVER a non-zero
return value of the ioctl doesn't indicate that the command has failed
so don't let watchdog(8) return an error in this case.

MFC after: 3 days

Sort sections.

Disable memory locking that could keep watchdogd from deadlocking itself
if the swap subsystem failed.

Requested by: phk

Now that mlockall(2) is unbroken, use it to keep watchdogd(8) permanently
out of swap.

mdoc(7) fixes.

Document -d flag

Assorted markup, grammar, and spelling fixes.

Bump the copyright year since I forgot last time.

Update comments to reflect changes made by phk. Also no longer need
<sys/sysctl.h>.

mdoc(7) janitor:
- Sort SEE ALSO by section number.
- Remove redundant ','.

mdoc(7) janitor:
- Remove EOL whitespace.
- Expand contracted words.
- Correct usage of .Fl macro.
- Use complete argument to -width.
- Remove redundant ','.

Rename the WATCHDOG option to SW_WATCHDOG and make it use the
generic watchdoc(9) interface.

Make watchdogd(8) perform as watchdog(8) as well, and make it
possible to specify a check command to run, timeout and sleep
periods.

Update watchdog(4) to talk about the generic interface and add
new watchdog(8) page.

style.Makefile(5):
Use WARNS?= instead of WARNS=.

o style(9) fixes
- Reordered #includes
- Only include <sys/types.h>, not it and <sys/cdefs.h>
o style.Makefile(5) fixes
- No SRCS= line when only one src file with same name as program
o Use warn()/errx() instead of fprintf()
- Integrated patch from Philippe Charnier <charnier@xp11.frmug.org>

Approved by: jeff (mentor)

Unbreak this for alpha and friends.

Double pointy hat to me, or something.

o Fix typo.

Submitted by: smkelly

- Add a software watchdog facility.

This commit has two pieces. One half is the watchdog kernel code which lives
primarily in hardclock() in sys/kern/kern_clock.c. The other half is a userland
daemon which, when run, will keep the watchdog from firing while the userland
is intact and functioning.

Approved by: jeff (mentor)