This package contains my shared, dynamic linker (ld.so) and utilities
(ldconfig and ldd) for Linux.

For those that were not involved in the development of ld.so, its main
feature is that the user-level, shared library and dynamic linking
support has been moved to its own, special shared library.  This has
two significant advantages.  First, the startup code for all binaries,
which must be linked statically, is reduced by about 2.5k.  Second,
and probably more important, the shared library and dynamic linking
support can be upgraded for all binaries without having to relink by
simply installing a new ld.so.

In addition to ld.so, this package also includes two, related
utilities, ldconfig and ldd.  Ldconfig is used to automatically update
symbolic links to shared libraries and build the library cache used by
ld.so.  This should hopefully put an end to the common problem of
accidentally deleting a critical library link (eg. /lib/libc.so.4).
Ldd is used to list the shared libraries dependencies for a binary.

Please see the included manual pages for further details.

To install, simply run "sh instldso.sh" as root.  Ready-to-go versions
of all end-products are provided so nothing should need to be compiled
or linked.

Both a.out and ELF versions of gcc are currently needed to recompile
everything.  If the ELF version is installed as the default, set the
value of GCC_DEFAULT to 'elf' in Config.mk, otherwise, either leave it
undefined or set it to a.out.

Notable contributors to this package include Eric Youngdale, Peter
MacDonald, Hongjiu Lu, Linus Torvalds, Lars Wirzenius, Mitch D'Souza 
and Rik Faith (not necessarily in that order).

Changes in version 1.6.5:

	Changed ldconfig to remove stale symbolic links.

	Added debug hooks in ld-linux.so and libdl.so to be used 
	by a future version of gdb (Eric Youngdale).

Changes in version 1.6.4:

	Change ld-linux.so to print on stdout instead of stderr
	when run from ldd.

	Added support for Debian GNU/Linux packaging.

Changes in version 1.6.3:

	Fixed a bug in libdl when closing a library (H.J. Lu).

Changes in version 1.6.2:

	Changed the error message printed by ldd when a file is
	not a.out or ELF.  It used to only list a.out formats.

	Changed ldconfig to no longer cache and set up links for
	ld-linux.so.

	Changed ld-linux.so and libdl to not conflict with upcoming
	changes in kernel header files.

	Changed ld-linux.so to not print preloaded libraries.

Changes in version 1.6.1:

	Updated the installation script.

	Changed ld.so and ld-linux.so to look for LD_AOUT_PRELOAD
	and LD_ELF_PRELOAD, respectively, before LD_PRELOAD.

	Changed ld.so and ld-linux.so to use LD_AOUT_LIBRARY_PATH
	and LD_ELF_LIBRARY_PATH, respectively, instead of
	AOUT_LD_LIBRARY_PATH and ELF_LD_LIBRARY_PATH.

Changes in version 1.6.0:

	Changed ldconfig to process libraries which do not have
	a minor version or patch level number.

	Incorporated ld-linux.so and libdl.so.

	Changed ld.so and ld-linux.so to not miss entries in the
	cache when the fully qualified library is requested.

	Changed ldconfig to use stdout instead of stderr when
	printing the cache.

Changes in version 1.5.3:

	LD_PRELOAD enhancements (Tristan Gigold).

	LD_PRELOAD patch for linux-68k (Andreas Schwab).

Changes in version 1.5.2:

	More ELF changes (Mitch D'Souza).

	Changed ldconfig to also update the link for ld-linux.so.

Changes in version 1.5.1:

	More ELF and LD_PRELOAD changes (Mitch D'Souza).

Changes in version 1.5.0:

	Chnaged all executables to QMAGIC (Mitch D'Souza and Rick
	Sladkey).

	Added preliminary support for ELF to ldd and ldconfig (Eric 
	Youndale and H.J. Lu).

	Added support for LD_PRELOAD to ld.so (Mitch D'Souza).

	Removed the "advertising" clause from the copyright notices
	in all source files.

Changes in version 1.4.4:

	Changed ldconfig to support QMAGIC libraries.

	Fixed a bug in ld.so where some of the error messages had
	transposed arguments.

Changes in version 1.4.3:

	Fixed an obscure bug in ld.so where an index was not being
	incremented when a library was not found using the cache.

Changes in version 1.4.2:

	Changed ldconfig to issue a warning and continue instead
	of an error and exiting when a link can't be updated.  
	This is useful when some libraries are imported on read-
	only file systems, such as an NFS mounted /usr.

	Changed ld.so to be more robust in searching for libraries.
	A library is not considered found unless it can actually be
	loaded.  If a library is not found using the cache, the
	standard directories are searched as in pre-cache versions.

Changes in version 1.4.1:

	Fixed minor Makefile problems.

	Added support for linux-68k.

	Fixed a bug in ld.so where libraries with absolute paths
	were not handled correctly.

	Changed ld.so to ignore the directory in the names of
	shared libraries by default.  This allows older libraries
	with absolute paths, such as the XView libraries, to take
	advantage of the cache support.

	Added a minimal usage message to ldconfig.

Changes in version 1.4:

	Fixed bug in ld.so where minor version numbers were not
	reported correctly when a minor version incompatibility
	was found.

	Fixed bug in ldconfig where libraries with subversion
	numbers greater than 9 were not compared correctly.

	Added Mitch D'Souza's support for suppressing warning
	messages from ld.so about minor version incompatibilities.

	Added Mitch D'Souza's support for using a cache to speed
	up searching for libraries in the standard directories.

	Added Mitch D'Souza's support for a debugging version of
	ld.so.  Link with -lldso if you think you are experiencing
	dynamic linker problems.

Changes in version 1.3:

	Added support for libraries using absolute pathnames.  If I
	had known that the XView libraries used them, I would have
	added this earlier.

	Fixed a bug handling old libraries using a pathname beginning
	with '/' or '/lib/'.

Changes in version 1.2a:

	Fixed a minor bug in ldd which caused all files, specifically
	scripts, to be recognized as binaries.  Thanks to Olaf Flebbe
	for reporting it.

David Engel
david@ods.com
