Fix bug in r242720, that caused additional status page to not be used if
descriptor page is supported.
The expand_name() function isn't called with the process lock held anymore,
so we can safely use malloc(M_WAITOK) now.

Pointed out by:	kib
Style cleanups.
Do not audit paths we try when kern.corefile contains %I.

Obtained from:	WHEEL Systems
The 'flags' argument can be modified in vn_open_cred(), so we need to
set it for every loop interation.

Pointed out by:	kib
Support restrict qualifier in dwarf debug info

Newer clang/llvm emit DW_TAG_restrict_type, which wasn't handled by gdb.
Import support from Apple's gdb-1822:

|  2009-03-24  Jason Molenda  (jmolenda@apple.com)
|
|    * gdbtypes.c (make_cv_type): Rename this function to make_cvr_type to
|    also handle restrict qualifiers.
|    (check_typedef): Handle TYPE_RESTRICT.
|    * gdbtypes.h (TYPE_FLAG_RESTRICT, TYPE_RESTRICT): New.
|    * hpread.c (hpread_type_lookup): Update to use make_cvr_type.
|    * stabsread.c (read_type): Pass the restrict qualifiers along.
|    * parse.c (follow_types): Pass the restrict qualifiers along.
|    * dwarf2read.c (read_tag_const_type): Call make_cvr_type.
|    (read_tag_volatile_type): Same.
|    (read_tag_restrict_type): New function.
|    (read_type_die): Handle DW_TAG_restrict_type.

Obtained from: Apple
Sponsored by: ADARA Networks
The selectroute functions does own account of EHOSTUNREACH errors,
no need to do it twice.

MFC after:	1 week
Make dst_sa initialization only when it is actually needed.

MFC after:	1 week
When we have some address to forward (e.g. it was specified with ipfw fwd),
we should pass it as first argument into in6_selectroute_fib function to
initiate new route lookup.

MFC after:	1 week
 - Correctly handle EWOULDBLOCK in quiesce_cpus

Discussed with:	mav
 - Add new machine parsable KTR macros for timing events.
 - Use this new format to automatically handle syscalls and VOPs.  This
   changes the earlier format but is still human readable.

Sponsored by:	EMC / Isilon Storage Division
Use NFSCL since NFSCLIENT build is broken at the moment
Post r243965 the nfsd daemon will not start up for kernels
built without "options INET6". This patch fixes the problem.

Reported by:	avg
Tested by:	avg
MFC after:	2 weeks
Use correct file permissions when looking for available core file if
kern.corefile contains %I.

Obtained from:	WHEEL Systems
Replace expand_name() function with corefile_open() function, which not
only returns name, but also vnode of corefile to use.

This simplifies the code and closes few races, especially in %I handling.

Reviewed by:	kib
Obtained from:	WHEEL Systems
Get the old NFSCLIENT to compile by adding now needed files.
Create an architecture-agnostic buffer pool manager that uses uma(9) to
manage a set of power-of-2 sized buffers for bus_dmamem_alloc().

This allows the caller to provide the back-end allocator uma allocator,
allowing full control of the memory pages backing the pool.  For
convenience, it provides an optional builtin allocator that provides pages
allocated with the VM_MEMATTR_UNCACHEABLE attribute, for managing pools of
DMA buffers for BUS_DMA_COHERENT or BUS_DMA_NOCACHE.

This also allows the caller to specify a minimum alignment, and it ensures
that all buffers start on a boundary and have a length that's a multiple of
that value, to avoid using buffers that trigger partial cache line flushes.

Submitted by:	Ian Lepore <freebsd@damnhippie.dyndns.org>
Use the new allocator in bus_dmamem_alloc().
Busdma enhancements, especially for managing small uncacheable buffers.

- Use the new architecture-agnostic buffer pool manager that uses uma(9)
  to manage a set of power-of-2 sized buffers for bus_dmamem_alloc().

- Create pools of buffers backed by both regular and uncacheable memory,
  and use them to handle regular versus BUS_DMA_COHERENT allocations.

- Use uma(9) to manage a pool of bus_dmamap structs instead of local code
  to manage a static list of 500 items (it took 3300 maps to get to
  multi-user mode, so the static pool wasn't much of an optimization).

- Small BUS_DMA_COHERENT allocations no longer waste an entire page per
  allocation, or set pages to uncached when they contain data other than
  DMA buffers.  There's no longer a need for drivers to work around the
  inefficiency by allocing large buffers then sub-dividing them.

- Because we know the alignment and padding of buffers allocated by
  bus_dmamem_alloc() (whether coherent or regular memory, and whether
  obtained from the pool allocator or directly from the kernel) we
  can avoid doing partial cacheline flushes on them.

- Add a fast-out to _bus_dma_could_bounce() (and some comments about
  what the routine really does because the old misplaced comment was wrong).

- Everywhere the dma tag alignment is used, the interpretation is that
  an alignment of 1 means no special alignment.  If the tag is created
  with an alignment argument of zero, store it in the tag as one, and
  remove all the code scattered around that changed 0->1 at point of use.

- Remove stack-allocated arrays of segments, use a local array of two
  segments within the tag struct, or dynamically allocate an array at first
  use if nsegments > 2.  On an arm system I tested, only 5 of 97 tags used
  more than two segments.  On my x86 desktop it was only 7 of 111 tags.

Submitted by:	Ian Lepore <freebsd@damnhippie.dyndns.org>
Use C comments instead of C++ comments.

Spotted out by:	gonzo (thanks, man)