Approved by:	re (implicit)

This commit was manufactured to restore the state of the 8.2-RELEASE image.

Move the __stack_chk_fail_local@FBSD_1.0 compat symbol definition into
the separate .o for libc_pic.a. This prevents rtld from making the
symbol global.

Reimplement pselect() in kernel, making change of sigmask and sleep atomic.

MFC r198538:
Move pselect(3) man page to section 2.

Approved by:	re (kib)

if the new file mode is the same as it was before; however, this
optimization must be disabled for filesystems that support NFSv4 ACLs.
Chmod uses pathconf(2) to determine whether this is the case - however,
pathconf(2) always follows symbolic links, while the 'chmod -h' doesn't.

This change adds lpathconf(3) to make it possible to solve that problem
in a clean way.

Reviewed by:	rwatson (earlier version)
Approved by:	re (kib)

- The uid/cuid members of struct ipc_perm are now uid_t instead of unsigned
  short.
- The gid/cgid members of struct ipc_perm are now gid_t instead of unsigned
  short.
- The mode member of struct ipc_perm is now mode_t instead of unsigned short
  (this is merely a style bug).
- The rather dubious padding fields for ABI compat with SV/I386 have been
  removed from struct msqid_ds and struct semid_ds.
- The shm_segsz member of struct shmid_ds is now a size_t instead of an
  int.  This removes the need for the shm_bsegsz member in struct
  shmid_kernel and should allow for complete support of SYSV SHM regions
  >= 2GB.
- The shm_nattch member of struct shmid_ds is now an int instead of a
  short.
- The shm_internal member of struct shmid_ds is now gone.  The internal
  VM object pointer for SHM regions has been moved into struct
  shmid_kernel.
- The existing __semctl(), msgctl(), and shmctl() system call entries are
  now marked COMPAT7 and new versions of those system calls which support
  the new ABI are now present.
- The new system calls are assigned to the FBSD-1.1 version in libc.  The
  FBSD-1.0 symbols in libc now refer to the old COMPAT7 system calls.
- A simplistic framework for tagging system calls with compatibility
  symbol versions has been added to libc.  Version tags are added to
  system calls by adding an appropriate __sym_compat() entry to
  src/lib/libc/incldue/compat.h. [1]

PR:		kern/16195 kern/113218 bin/129855
Reviewed by:	arch@, rwatson
Discussed with:	kan, kib [1]

any open file descriptors >= 'lowfd'.  It is largely identical to the same
function on other operating systems such as Solaris, DFly, NetBSD, and
OpenBSD.  One difference from other *BSD is that this closefrom() does not
fail with any errors.  In practice, while the manpages for NetBSD and
OpenBSD claim that they return EINTR, they ignore internal errors from
close() and never return EINTR.  DFly does return EINTR, but for the common
use case (closing fd's prior to execve()), the caller really wants all
fd's closed and returning EINTR just forces callers to call closefrom() in
a loop until it stops failing.

Note that this implementation of closefrom(2) does not make any effort to
resolve userland races with open(2) in other threads.  As such, it is not
multithread safe.

Submitted by:	rwatson (initial version)
Reviewed by:	rwatson
MFC after:	2 weeks

interface as nmount(2).  Three new system calls are added:
* jail_set, to create jails and change the parameters of existing jails.
  This replaces jail(2).
* jail_get, to read the parameters of existing jails.  This replaces the
  security.jail.list sysctl.
* jail_remove to kill off a jail's processes and remove the jail.
Most jail parameters may now be changed after creation, and jails may be
set to exist without any attached processes.  The current jail(2) system
call still exists, though it is now a stub to jail_set(2).

Approved by:	bz (mentor)

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