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 r229768:
Implement fdlopen(3), an rtld interface to load shared object by file
descriptor.

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

Approved by: re (implicit)

Fix typos, spelling, formatting and mdoc mistakes found by Nobuyuki while
translating these manual pages. Minor corrections by me.

Submitted by: Nobuyuki Koganemaru <n-kogane@syd.odn.ne.jp>

mdoc: order prologue macros consistently by Dd/Dt/Os

Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.

Reviewed by: ru
Approved by: philip, ed (mentors)

- Remove const'ness from dlerror(3) prototype, for consistency with POSIX.

Approved by: cognet
MFC after: 1 week

Implement RTLD_NOLOAD flag for dlopen(3).

Requested and tested by: jkim
Reviewed by: kan
Approved by: re (kensmith)

Document RTLD_NODELETE, -z nodelete and -z origin support.

Fix the ordering in the description of the dlsym() lookup procedure to
reflect src/libexec/rtld-elf/rtld.c rev. 1.68 - the globally-loaded
objects (RTLD_GLOBAL) are searched before the local object's DAG's.

PR: 62770
Submitted by: Kimura Fuyuki <fuyuki@nigredo.org>

Mention that dlerror() is also applicable to retrieve error message after
dladdr() and dlinfo() functions calls.

o Document that dlsym()'s behaviour with new special handle RTLD_SELF

o Add cross reference to dlinfo(3)
o Minor mdoc nits

mdoc(7) police: "The .Fa argument.".

mdoc(7) police: "The .Fn function".

Add `restrict' type-qualifier.

mdoc(7) police: laundry.

Since POSIX gives us plenary authority to define _t types, change
__dlfunc_t to dlfunc_t to match what I have proposed to the Austin
Group. (This also makes it easier for applications to store these
values before they decide what to do with them, e.g., in a wrapper
function.)

Reorganize dlfcn.h slightly to separate out XSI and BSD interfaces.
Add new dlfunc() interface, which is a version of dlsym() with a
return type that can be cast to a function pointer without turning
your computer into a frog.

Reviewed by: freebsd-standards

(forced)

Previous commit (ldd on shlibs) is a subject of:

MFC after: 2 weeks

Allow ldd(1) be used on shared libraries in addition to executables.

mdoc(7) police: Use the new .In macro for #include statements.

mdoc(7) police: removed HISTORY info from the .Os call.

Xref dladdr(3).

Requested by: -hackers

mdoc(7) police: split punctuation characters + misc fixes.

Prepare for mdoc(7)NG.

Whitespace only change: trim trailing whitespace.

Document RTLD_DEFAULT and the search algorithm used for resolving
undefined symbols.

Make a somewhat unsatisfactory attempt to describe the effects of
the RTLD_GLOBAL and RTLD_LOCAL flags which can be passed to dlopen().

Introduce ".Lb" macro to libc manpages.

More libraries manpages updates following.

It is no longer necessary to prepend underscores to external symbols under
ELF.

Submitted by: A.Leidinger@WJPServer.CS.Uni-SB.de (Alexander Leidinger)

$Id$ -> $FreeBSD$

Add $Id$, to make it simpler for members of the translation teams to
track.

The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;

.\" $Id$
.\"

If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.

Approved by: bde

Back out my change from 6 April PDT that added a new dlversion()
function. It was an ill-considered feature. It didn't solve the
problem I wanted it to solve. And it added Yet Another Version
Number that would have to be maintained at every release point.
I'm nuking it now before anybody grows too fond of it.

Add a new function dlversion() which returns the version number of
the dynamic linker in the same form as __FreeBSD_version. This is
mainly intended for checking the dynamic linker version during a make
world.

Add a note about ELF executables requiring to be linked with -export-dynamic
for dlsym() searches inside the executable to work.

Correct a typo that I noticed.

Move the trampolines for dlopen and related functions from crt0.o
into libc. This reduces the size of every dynamically linked
executable by 248 bytes, and it reduces the size of static executables
by a lesser amount. It also eliminates some global namespace
pollution.

With this change in place, the source for dlfcn.h should probably
be moved to "/usr/src/include". I'll save that for another day.

Compatibility note: Programs which use dlopen, if compiled on
systems with this change, will not run on systems with a libc from
prior to this change. Very few programs use dlopen, so I think
that is OK.