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

MFC r267651 (by attilio):
Add the possibility to specify ecx when performing cpuid calls.

MFC r267673:
Restore the ABI of the cpuctl(4) ioctl request CPUCTL_CPUID.

MFC r267814:
Make cpuctl_do_cpuid() and cpuctl_do_cpuid_count() return void.

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

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

Avoid clobbering errno with a call to fprintf

PR: bin/173923
Submitted by: Garrett Cooper <yanegomi@gmail.com>
Approved by: cperciva
MFC After: 3 days

While 'make universe' passed this didn't work with clang.

This reverts r242120

Submitted by: Jan Beich
Approved by: cperciva (implicit)

This utility builds without NO_WCAST_ALIGN

Tested with make universe

No objections from: stas
Approved by: cperciva
MFC after: 3 days

More -Wmissing-variable-declarations fixes.

In addition to adding `static' where possible:

- bin/date: Move `retval' into extern.h to make it visible to date.c.
- bin/ed: Move globally used variables into ed.h.
- sbin/camcontrol: Move `verbose' into camcontrol.h and fix shadow warnings.
- usr.bin/calendar: Remove unneeded variables.
- usr.bin/chat: Make `line' local instead of global.
- usr.bin/elfdump: Comment out unneeded function.
- usr.bin/rlogin: Use _Noreturn instead of __dead2.
- usr.bin/tset: Pull `Ospeed' into extern.h.
- usr.sbin/mfiutil: Put global variables in mfiutil.h.
- usr.sbin/pkg: Remove unused `os_corres'.
- usr.sbin/quotaon, usr.sbin/repquota: Remove unused `qfname'.

cpucontrol: use CPUCTL_UPDATE ioctl on correct file descriptor

I guess that means that microcode update has never worked for AMD CPUs.
Please also note that only older AMD CPUs and micrcode file format are
supported anyway (pre 10h family).

MFC after: 1 week

Fixes to man8 groff mandoc style, usage mistakes, or typos.

PR: 168016
Submitted by: Nobuyuki Koganemaru
Approved by: gjb
MFC after: 3 days

Hide DIR definition by making it an opaque struct typedef.

Introduce dirfd() libc exported symbol replacing macro with same name,
preserve _dirfd() macro for internal use.

Replace dirp->dd_fd with dirfd() call. Avoid using dirfd as variable
name to prevent shadowing global symbol.

Sponsored by: Google Summer Of Code 2011

Fix warning when compiling with gcc46:
error: variable 'flags' set but not used

Approved by: dim, cperciva (mentor, blanket for pre-mentorship already-approved commits)
MFC after: 3 days

Use NO_WCAST_ALIGN for usr.sbin/cpucontrol; because this is only built
for x86, any alignment warnings can be safely ignored.

MFC after: 1 week

Add VIA microde update support to cpuctl(4) and cpucontrol(8).

Support have been tested with X2 CPU and QuadCore CPU.

MFC after: 1 month

- Save some space relying on the fact that all ioctl commands
prefixes are the same.

Suggested by: "Carlos A. M. dos Santos" <unixmania@gmail.com>

- Show textual representation of ioctl command in warning message
if ioctl(4) is failed besides the command number.

Suggested by: delphij
MFC after: 2 weeks

Remove dead assignments, we overwrite the variable almost immediately.

Found by: clang static analyzer

mdoc: move CAVEATS, BUGS and SECURITY CONSIDERATIONS sections to the
bottom of the manpages and order them consistently.

GNU groff doesn't care about the ordering, and doesn't even mention
CAVEATS and SECURITY CONSIDERATIONS as common sections and where to put
them.

Found by: mdocml lint run
Reviewed by: ru

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.

(S)LIST_HEAD_INITIALIZER takes a (S)LIST_HEAD as an argument.
Fix some wrong usages.
Note: this does not affect generated binaries as this argument is not used.

PR: 137213
Submitted by: Eygene Ryabinkin (initial version)
MFC after: 1 month

- Add support to atomically set/clear individual bits of a MSR register
via cpuctl(4) driver. Two new CPUCTL_MSRSBIT and CPUCTL_MSRCBIT ioctl(2)
calls treat the data field of the argument struct passed as a mask
and set/clear bits of the MSR register according to the mask value.
- Allow user to perform atomic bitwise AND and OR operaions on MSR registers
via cpucontrol(8) utility. Two new operations ("&=" and "|=") have been
added. The first one applies bitwise AND operaion between the current
contents of the MSR register and the mask, and the second performs bitwise
OR. The argument can be optionally prefixed with "~" inversion operator.
This allows one to mimic the "clear bit" behavior by using the command
like this:
cpucontrol -m 0x10&=~0x02 # clear the second bit of TSC MSR

Inversion operator support in all modes (assignment, OR, AND).

Approved by: re (kib)
MFC after: 1 month

Correct the information about when the respective functionality first
appeared in FreeBSD.

PR: 133785
Submitted by: Ulrich Spoerlein <uqs@spoerlein.net>
MFC after: 3 days

- use .Ex macro in EXIT STATUS section

- Improve wording.

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

Mdoc and wording improvements.

- Fix error reporting.

Approved by: kib

- Add cpuctl(4) pseudo-device driver to provide access to some low-level
features of CPUs like reading/writing machine-specific registers,
retrieving cpuid data, and updating microcode.
- Add cpucontrol(8) utility, that provides userland access to
the features of cpuctl(4).
- Add subsequent manpages.

The cpuctl(4) device operates as follows. The pseudo-device node cpuctlX
is created for each cpu present in the systems. The pseudo-device minor
number corresponds to the cpu number in the system. The cpuctl(4) pseudo-
device allows a number of ioctl to be preformed, namely RDMSR/WRMSR/CPUID
and UPDATE. The first pair alows the caller to read/write machine-specific
registers from the correspondent CPU. cpuid data could be retrieved using
the CPUID call, and microcode updates are applied via UPDATE.

The permissions are inforced based on the pseudo-device file permissions.
RDMSR/CPUID will be allowed when the caller has read access to the device
node, while WRMSR/UPDATE will be granted only when the node is opened
for writing. There're also a number of priv(9) checks.

The cpucontrol(8) utility is intened to provide userland access to
the cpuctl(4) device features. The utility also allows one to apply
cpu microcode updates.

Currently only Intel and AMD cpus are supported and were tested.

Approved by: kib
Reviewed by: rpaulo, cokane, Peter Jeremy
MFC after: 1 month