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

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

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

Bump date.

Similar to 233760 and 236717, export some more useful info about the
kernel-based POSIX semaphore descriptors to userland via procstat(1) and
fstat(1):
- Change sem file descriptors to track the pathname they are associated
with and add a ksem_info() method to copy the path out to a
caller-supplied buffer.
- Use the fo_stat() method of shared memory objects and ksem_info() to
export the path, mode, and value of a semaphore via struct kinfo_file.
- Add a struct semstat to the libprocstat(3) interface along with a
procstat_get_sem_info() to export the mode and value of a semaphore.
- Teach fstat about semaphores and to display their path, mode, and value.

MFC after: 2 weeks

mdoc: end function context properly.

Bump date.

Add procstat_getkstack function to dump kernel stacks of a process.

MFC after: 1 month

Add procstat_getauxv function to retrieve a process auxiliary vector.

MFC after: 1 month

Extend libprocstat with functions to retrieve process command line
arguments and environment variables.

Suggested by: stas
Reviewed by: jhb and stas (initial version)
MFC after: 1 month

Add procstat_getosrel function to retrieve a process osrel info.

MFC after: 1 month

Add procstat_getpathname function to retrieve a process executable.

MFC after: 1 month

Add procstat_getrlimit function to retrieve a process resource limits info.

MFC after: 1 month

Add procstat_getumask function to retrieve a process umask.

MFC after: 1 month

Add procstat_getgroups function to retrieve process groups.

MFC after: 1 month

Add procstat_getvmmap function to get VM layout of a process.

MFC after: 1 month

Make libprocstat(3) extract procstat notes from a process core file.

PR: kern/173723
Suggested by: jhb
Glanced by: kib
MFC after: 1 month

General mdoc(7) and typo fixes.

PR: 167734
Submitted by: Nobuyuki Koganemaru (kogane!jp.freebsd.org)
MFC after: 3 days

Export some more useful info about shared memory objects to userland
via procstat(1) and fstat(1):
- Change shm file descriptors to track the pathname they are associated
with and add a shm_path() method to copy the path out to a caller-supplied
buffer.
- Use the fo_stat() method of shared memory objects and shm_path() to
export the path, mode, and size of a shared memory object via
struct kinfo_file.
- Add a struct shmstat to the libprocstat(3) interface along with a
procstat_get_shm_info() to export the mode and size of a shared memory
object.
- Change procstat to always print out the path for a given object if it
is valid.
- Teach fstat about shared memory objects and to display their path,
mode, and size.

MFC after: 2 weeks

Mention myself in the AUTHORS section.

Requested by: stas

Provide a simple manual page for libprocstat(3).

Reviewed by: jilles, gjb