Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC 266293:
- Add support for dumping current resource usage for processes via a new -r
flag to procstat.
- Add an -H flag to request information about threads rather than processes
when dumping statistics. Currently it is only used for -r to display
resource usage for individual threads instead of the entire process.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Use procstat_getkstack(3) for retrieving process kernel stacks
instead of direct sysctl calls.

MFC after: 1 month

Use libprocstat(3) to retrieve ELF auxiliary vector.

MFC after: 1 month

Use libprocstat(3) to retrieve process command line arguments and
environment variables.

MFC after: 1 month

Use libprocstat(3) when retrieving binary information for a process.

MFC after: 1 month

Use procstat_getrlimit(3) for retrieving rlimit information instead of
direct sysctl calls.

MFC after: 1 month

Use procstat_getgroups(3) for retrieving groups information instead of
direct sysctl.

MFC after: 1 month

Use more generic procstat_getvmmap(3) for retrieving VM layout of a process.

MFC after: 1 month

Use procstat_getprocs(3) for retrieving thread information instead of
direct sysctl calls.

MFC after: 1 month

usr.bin/procstat

Add -l flag to display resource limits.

PR: bin/161257
Reviewed by: kib
MFC after: 2 weeks

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

MFC after: 2 weeks

Updates to libprocstat(3) and procstat(1) to allow monitoring Capsicum
capability mode and capabilities.

Right now no attempt is made to unwrap capabilities when operating on
a crashdump, so further refinement is required.

Approved by: re (bz)
Sponsored by: Google Inc

- 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

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>