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 r227956, r228090, r228446, r230471, r230548:

r227956:

Add -l flag to display resource limits.

PR: bin/161257
Reviewed by: kib

r228090:

Update SYNOPSIS to include the flags added recently.

Spotted by: jhb

r228446:

Make procstat -l output similar to the output of limits(1).

Suggested by: jhb

r230471, r230548:

Make procstat -l to work with the new version of kern.proc.rlimit.

Submitted by: Andrey Zonov <andrey at zonov.org>

MFC r227838, r227873, r228025, r228049, r228289, r228447, r230753:

r227838, r227873:

Add new options, -e and -x, to display process environment variables
and ELF auxiliary vectors.

r228025, r228049:

Make proctstat -x output more readable.

This also fixes the issue, spotted by mdf, with values that were
printed as decimal and had hex prefixes.

Discussed with: kib, rwatson

r228289:

Don't output a warning if kern.proc.auxv sysctl has returned EPERM.
After r228288 this is rather a normal situation.

r228447:

Make 64-bit procstat output ELF auxiliary vectors for 32-bit processes.

Reviewed by: kib

r230753:

Always return 0 if the sysctl failed.

This fixes the bug: when procstat -xa was run and the sysctl for a
process returned ESRCH or EPERM, for this process procstat output the
result collected for the previous successful process.

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

Approved by: re (implicit)

- Commit work from libprocstat project. These patches add support for runtime
file and processes information retrieval from the running kernel via sysctl
in the form of new library, libprocstat. The library also supports KVM backend
for analyzing memory crash dumps. Both procstat(1) and fstat(1) utilities have
been modified to take advantage of the library (as the bonus point the fstat(1)
utility no longer need superuser privileges to operate), and the procstat(1)
utility is now able to display information from memory dumps as well.

The newly introduced fuser(1) utility also uses this library and able to operate
via sysctl and kvm backends.

The library is by no means complete (e.g. KVM backend is missing vnode name
resolution routines, and there're no manpages for the library itself) so I
plan to improve it further. I'm commiting it so it will get wider exposure
and review.

We won't be able to MFC this work as it relies on changes in HEAD, which
was introduced some time ago, that break kernel ABI. OTOH we may be able
to merge the library with KVM backend if we really need it there.

Discussed with: rwatson

Teach procstat(1) to display some information about signal disposition
and pending/blocked status for signals.

Reviewed by: rwatson
MFC after: 2 weeks

Build usr.bin/ with WARNS=6 by default.

Also add some missing $FreeBSD$ to keep svn happy.

Merge user/peter/kinfo branch as of r185547 into head.

This changes struct kinfo_filedesc and kinfo_vmentry such that they are
same on both 32 and 64 bit platforms like i386/amd64 and won't require
sysctl wrapping.

Two new OIDs are assigned. The old ones are available under
COMPAT_FREEBSD7 - but it isn't that simple. The superceded interface
was never actually released on 7.x.

The other main change is to pack the data passed to userland via the
sysctl. kf_structsize and kve_structsize are reduced for the copyout.
If you have a process with 100,000+ sockets open, the unpacked records
require a 132MB+ copyout. With packing, it is "only" ~35MB. (Still
seriously unpleasant, but not quite as devastating). A similar problem
exists for the vmentry structure - have lots and lots of shared libraries
and small mmaps and its copyout gets expensive too.

My immediate problem is valgrind. It traditionally achieves this
functionality by parsing procfs output, in a packed format. Secondly, when
tracing 32 bit binaries on amd64 under valgrind, it uses a cross compiled
32 bit binary which ran directly into the differing data structures in 32
vs 64 bit mode. (valgrind uses this to track file descriptor operations
and this therefore affected every single 32 bit binary)

I've added two utility functions to libutil to unpack the structures into
a fixed record length and to make it a little more convenient to use.

Add procstat(1), a process inspection utility. This provides both some
of the missing functionality from procfs(4) and new functionality for
monitoring and debugging specific processes. procstat(1) operates in
the following modes:

-b Display binary information for the process.
-c Display command line arguments for the process.
-f Display file descriptor information for the process.
-k Display the stacks of kernel threads in the process.
-s Display security credential information for the process.
-t Display thread information for the process.
-v Display virtual memory mappings for the process.

Further revision and modes are expected.

Testing, ideas, etc: cognet, sam, Skip Ford <skip at menantico dot com>
Wesley Shields <wxs at atarininja dot org>