'RELENG_7_0_0_RELEASE'.

This commit was manufactured to restore the state of the 7.0-RELEASE image.

Convert malloc()/bzero() to malloc(M_ZERO).

Obtained from:  OpenBSD
MFC after:      3 days
Approved by:    re (kensmith)

and its bibliography.

Submitted by:   Tomoyuki Okazaki <okazaki at kick dot gr dot jp>
MFC after:      1 month

and flags with an sxlock.  This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention.  All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently.  Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.

- Generally eliminate the distinction between "fast" and regular
  acquisisition of the filedesc lock; the plan is that they will now all
  be fast.  Change all locking instances to either shared or exclusive
  locks.

- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
  was called without the mutex held; sx_sleep() is now always called with
  the sxlock held exclusively.

- Universally hold the struct file lock over changes to struct file,
  rather than the filedesc lock or no lock.  Always update the f_ops
  field last. A further memory barrier is required here in the future
  (discussed with jhb).

- Improve locking and reference management in linux_at(), which fails to
  properly acquire vnode references before using vnode pointers.  Annotate
  improper use of vn_fullpath(), which will be replaced at a future date.

In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).

Tested by:	kris
Discussed with:	jhb, kris, attilio, jeff

o make all crypto drivers have a device_t; pseudo drivers like the s/w
  crypto driver synthesize one
o change the api between the crypto subsystem and drivers to use kobj;
  cryptodev_if.m defines this api
o use the fact that all crypto drivers now have a device_t to add support
  for specifying which of several potential devices to use when doing
  crypto operations
o add new ioctls that allow user apps to select a specific crypto device
  to use (previous ioctls maintained for compatibility)
o overhaul crypto subsystem code to eliminate lots of cruft and hide
  implementation details from drivers
o bring in numerous fixes from Michale Richardson/hifn; mostly for
  795x parts
o add an optional mechanism for mmap'ing the hifn 795x public key h/w
  to user space for use by openssl (not enabled by default)
o update crypto test tools to use new ioctl's and add cmd line options
  to specify a device to use for tests

These changes will also enable much future work on improving the core
crypto subsystem; including proper load balancing and interposing code
between the core and drivers to dispatch small operations to the s/w
driver as appropriate.

These changes were instigated by the work of Michael Richardson.

Reviewed by:	pjd
Approved by:	re

  or SHA512, the blocksize is 128 bytes, not 64 bytes as anywhere else.
  The bug also exists in NetBSD, OpenBSD and various other independed
  implementations I look at.
- We cannot decide which hash function to use for HMAC based on the key
  length, because any HMAC function can use any key length.
  To fix it split CRYPTO_SHA2_HMAC into three algorithm:
  CRYPTO_SHA2_256_HMAC, CRYPTO_SHA2_384_HMAC and CRYPTO_SHA2_512_HMAC.
  Those names are consistent with OpenBSD's naming.
- Remove authsize field from auth_hash structure.
- Allow consumer to define size of hash he wants to receive.
  This allows to use HMAC not only for IPsec, where 96 bits MAC is requested.
  The size of requested MAC is defined at newsession time in the cri_mlen
  field - when 0, entire MAC will be returned.
- Add swcr_authprepare() function which prepares authentication key.
- Allow to provide key for every authentication operation, not only at
  newsession time by honoring CRD_F_KEY_EXPLICIT flag.
- Make giving key at newsession time optional - don't try to operate on it
  if its NULL.
- Extend COPYBACK()/COPYDATA() macros to handle CRYPTO_BUF_CONTIG buffer
  type as well.
- Accept CRYPTO_BUF_IOV buffer type in swcr_authcompute() as we have
  cuio_apply() now.
- 16 bits for key length (SW_klen) is more than enough.

Reviewed by:	sam

in kernel. Useful for testing.

Reviewed by:	sam

and want to have crypto support loaded as KLD. By moving zlib to separate
module and adding MODULE_DEPEND directives, it is possible to use such
configuration without complication. Otherwise, since IPSEC is linked with
zlib (just like crypto.ko) you'll get following error:

	interface zlib.1 already present in the KLD 'kernel'!

Approved by:	cognet (mentor)

This is actually a local DoS, as every user can use /dev/crypto if there
is crypto hardware in the system and cryptodev.ko is loaded (or compiled
into the kernel).

Reported by:	Mike Tancsa <mike@sentex.net>
MFC after:	1 day