Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC: r234352

Implement pipe2 syscall for Linuxulator.

MFC r235063 (by netchild@):
- >500 static DTrace probes for the linuxulator
- DTrace scripts to check for errors, performance, ...
they serve mostly as examples of what you can do with the static probes
with moderate load the scripts may be overwhelmed, excessive lock-tracing
may influence program behavior (see the last design decission)

Design decissions:
- use "linuxulator" as the provider for the native bitsize; add the
bitsize for the non-native emulation (e.g. "linuxuator32" on amd64)
- Add probes only for locks which are acquired in one function and released
in another function. Locks which are aquired and released in the same
function should be easy to pair in the code, inter-function
locking is more easy to verify in DTrace.
- Probes for locks should be fired after locking and before releasing to
prevent races (to provide data/function stability in DTrace, see the
man-page of "dtrace -v ..." and the corresponding DTrace docs).

Manual merge futex part of r227293 (by ed@):
Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

MFC r235078 (by uqs@):
Fix make depend.

MFC r232799:
- add comments to syscalls.master and linux(32)_dummy about which linux
kernel version introduced the sysctl (based upon a linux man-page)
- add comments to syscalls.master regarding some names of sysctls which are
different than the linux-names (based upon the linux unistd.h)
- add some dummy sysctls
- name an unimplemented sysctl

MFC 228957:
Implement linux_fadvise64() and linux_fadvise64_64() using
kern_posix_fadvise().

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

linux compat: add non-dummy capget and capset system calls, regenerate

And drop dummy definitions for those system calls.
This may transiently break the build.

PR: kern/149168
Submitted by: John Wehle <john@feith.com>
Reviewed by: netchild
MFC after: 2 weeks

Implement robust futexes. Most of the code is modelled after
what Linux does. This is because robust futexes are mostly
userspace thing which we cannot alter. Two syscalls maintain
pointer to userspace list and when process exits a routine
walks this list waking up processes sleeping on futexes
from that list.

Reviewed by: kib (mentor)
MFC after: 1 month

Implement linux_truncate64() syscall.

Tested by: Aline de Freitas <aline@riseup.net>
Approved by: kib (mentor)

Add stubs for syscalls introduced in Linux 2.6.17 kernel.
Some GNU libc version started using them before 2.6.17 was officially out.

MFC after: 3 days

Implement the linux syscalls
openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat,
renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat.

Submitted by: rdivacky
Sponsored by: Google Summer of Code 2007
Tested by: pho

Implement settimeofday() for Linuxulator/amd64.

Submitted by: Scot Hetzel (swhetzel at gmail dot com)

Implement the openat() linux syscall
Submitted by: Roman Divacky (rdivacky@)
MFC after: 2 weeks

MFp4 (111746, 108671, 108945, 112352):
- add linux utimes syscall [1]
- add linux rt_sigtimedwait syscall [2]

Submitted by: "Scot Hetzel" <swhetzel@gmail.com> [1]
Submitted by: Bruce Becker <hostmaster@whois.gts.net> [2]
PR: 93199 [2]

MFP4:
Implement prctl().

Submitted by: rdivacky
Tested with: LTP

Add the linux statfs64 call. This allows Tivoli backup to proceed a little
but further on -current (still not successful, but a step into the right
direction).

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Tested by: Paul Mather <paul@gromit.dlib.vt.edu>

Add the linux 2.6.x stuff (not used by default!):
- TLS - complete
- pid/tid mangling - complete
- thread area - complete
- futexes - complete with issues
- clone() extension - complete with some possible minor issues
- mq*/timer*/clock* stuff - complete but untested and the mq* stuff is
disabled when not build as part of the kernel with native FreeBSD mq*
support (module support for this will come later)

Tested with:
- linux-firefox - works, tested
- linux-opera - works, tested
- linux-realplay - doesnt work, issue with futexes
- linux-skype - doesnt work, issue with futexes
- linux-rt2-demo - works, tested
- linux-acroread - doesnt work, unknown reason (coredump) and sometimes
issue with futexes
- various unix utilities in linux-base-gentoo3 and linux-base-fc4:
everything tried worked

On amd64 not everything is supported like on i386, the catchup is planned for
later when the remaining bugs in the new functions are fixed.

To test this new stuff, you have to run
sysctl compat.linux.osrelease=2.6.16
to switch back use
sysctl compat.linux.osrelease=2.4.2

Don't switch while running a linux program, strange things may or may not
happen.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Some suggestions/help by: jhb, kib, manu@NetBSD.org, netchild

Commit the DUMMY stuff (printing messages for missing syscalls) for amd64 too.

Submitted by: rdivacky
Sponsored by: Google SoC 2006
Noticed by: jkim
Pointyhat to: netchild

Implement rt_sigpending in the linuxolator.

PR: 92671
Submitted by: Markus Niemist"o <markus.niemisto@gmx.net>

Add preliminary support for running 32-bit Linux binaries on amd64, enabled
with the COMPAT_LINUX32 option. This is largely based on the i386 MD Linux
emulations bits, but also builds on the 32-bit FreeBSD and generic IA-32
binary emulation work.

Some of this is still a little rough around the edges, and will need to be
revisited before 32-bit and 64-bit Linux emulation support can coexist in
the same kernel.