Commit Graph

54 Commits

Author SHA1 Message Date
Joel Dahl
df2d82e003 mdoc: remove superfluous paragraph macros. 2014-06-23 18:40:21 +00:00
Jonathan Anderson
02d3b38e0a Add the LD_LIBRARY_PATH_FDS environmental variable.
This variable allows the loading of shared libraries via directory descriptors
rather than via library paths.  If LD_LIBRARY_PATH_FDS=3:4:12, the directories
represented by file descriptors 3, 4 and 12 will searched for shared libraries
before the normal path-based mechanisms are used.  This allows us to execute
unprivileged binaries from within a Capsicum sandbox even if they require
shared libraries.

Approved by:	rwatson (mentor)
Reviewed by:	kib
MFC after:	3 weeks
Sponsored by:	DARPA/AFRL
2014-06-20 17:08:32 +00:00
Konstantin Belousov
bca2f6239d Import the DragonFly BSD commit 4f0bc915b65fcf5a23214f6d221d65c80be68ad4
by John Marino <draco@marino.st>, with the following (edited) commit
message
Date: Sat, 24 Mar 2012 06:40:50 +0100
Subject: [PATCH 1/1] rtld: Implement DT_RUNPATH and -z nodefaultlib

DT_RUNPATH is incorrectly being considered as an alias of DT_RPATH.  The
purpose of DT_RUNPATH is to have two different types of rpath: one that
can be overridden by the environment variable LD_LIBRARY_PATH and one that
can't.  With the currently implementation, LD_LIBRARY_PATH will always
trump any embedded rpath or runpath tags.

Current path search order by rtld:
==================================
LD_LIBRARY_PATH
DT_RPATH / DT_RUNPATH (always the same)
ldconfig hints file (default: /var/run/ld-elf.so.hints)
/usr/lib

New path search order by rtld:
==============================
DT_RPATH of the calling object if no DT_RUNPATH
DT_RPATH of the main binary if no DT_RUNPATH and binary isn't calling obj
LD_LIBRARY_PATH
DT_RUNPATH
ldconfig hints file
/usr/lib

The new path search matches how the linux runtime loader works.  The other
major added feature is support for linker flag "-z nodefaultlib".  When
this flag is passed to the linker, rtld will skip all references to the
standard library search path ("/usr/lib" in this case but it could handle
more color delimited paths) except in DT_RPATH and DT_RUNPATH.

New path search order by rtld with -z nodefaultlib flag set:
============================================================
DT_RPATH of the calling object if no DT_RUNPATH
DT_RPATH of the main binary if no DT_RUNPATH and binary isn't calling obj
LD_LIBRARY_PATH
DT_RUNPATH
ldconfig hints file (skips all references to /usr/lib)

FreeBSD notes:
- we fixed some bugs which were submitted to DragonFly and merged there
  as commit 1ff8a2bd3eb6e5587174c6a983303ea3a79e0002;
- we added LD_LIBRARY_PATH_RPATH environment variable to switch to
  the previous behaviour of considering DT_RPATH a synonym for DT_RUNPATH;
- the FreeBSD default search path is /lib:/usr/lib and not /usr/lib.

Reviewed by:   kan
MFC after:     1 month
MFC note:      flip the ld_library_path_rpath default value for stable/9
2012-07-15 10:53:48 +00:00
Konstantin Belousov
8569deaf1c Implement support for ELF filters in rtld. Both normal and auxillary
filters are implemented.

Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.

Consolidate common arguments of the symbol lookup functions in the
SymLook structure.  Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.

Reviewed by:	kan
Tested by:	Mykola Dzham <i levsha me>, nwhitehorn (powerpc)
2010-12-25 08:51:20 +00:00
Ulrich Spörlein
0d9deed52c mdoc: drop redundant .Pp and .LP calls
They have no effect when coming in pairs, or before .Bl/.Bd
2010-10-08 12:40:16 +00:00
Konstantin Belousov
b2e4ce45d9 Document RTLD_NODELETE, -z nodelete and -z origin support. 2009-04-01 14:38:20 +00:00
Xin LI
569e2ef6a9 Support for a new environment variable, LD_ELF_HINTS_PATH for overriding
the rtld hints file.  This environment variable would be unset if the
process is considered as tainted with setuid/setgid.  This feature gives
a convenient way of using a custom set of shared library that is not
located in the default location and switch back.

Feature requested by:	iXsystems
Original patch by:	John Hixson
MFC after:		2 weeks
2009-03-23 16:49:00 +00:00
Bruce M Simpson
523b17effe Make the meaning of the %A format specifier, as passed to
LD_TRACE_LOADED_OBJECTS_FMT[12], more obvious for users like me.
2008-05-15 10:47:14 +00:00
Christian S.J. Peron
b075897e99 Update the man page to reflect that certain variables will be unset in
the case that the program is set-user-ID or set-group-ID. Add missing
annotations for LIBMAP and LIBMAP_DISABLE.
2007-05-17 19:14:25 +00:00
Pav Lucistnik
88922cf00e Remove %m formatter, it's ifdef 0'ed in the code from the very beginning
MFC after:	1 week
2007-05-12 12:26:25 +00:00
Pav Lucistnik
b9e1d83e61 Expand documentation for LD_TRACE_LOADED_OBJECTS_FMT? variables
PR:		docs/66265 (inspired by)
Submitted by:	Michel Lavondes <fox@vader.aacc.cc.md.us>
MFC after:	1 week
2007-05-12 12:24:49 +00:00
John Baldwin
f0ac0f92fb Document LD_UTRACE.
MFC after:	3 days
2007-01-23 22:38:39 +00:00
Ruslan Ermilov
a3ec17db37 Markup fixes. 2006-09-17 21:48:47 +00:00
Pav Lucistnik
8a50f51b1b - Document LD_32_* environment variables
- Mention 32-bit files in FILES section

MFC after:	1 week
2006-03-27 00:53:58 +00:00
Ruslan Ermilov
cc4fdb1de9 Removed trailing whitespace.
Approved by:	re (blanket)
2005-06-14 08:41:11 +00:00
Matthew N. Dodd
5b08cb0449 Description from Dan:
Another handy libmap patch.  Lets you do stuff like this:

	LD_LIBMAP="libpthread.so.1=libthr.so.1" mythreadedapp

	If you already have a program-specific override in libmap.conf, note
	that you must use a program-specific override in LD_LIBMAP:

	LD_LIBMAP="[mythreadedapp],libpthread.so.1=libthr.so.1" mythreadedapp

PR:		bin/74471
Submitted by:	Dan Nelson <dnelson AT allantgroup.com>
MFC after:	2 weeks
2005-02-04 02:46:41 +00:00
Matthew N. Dodd
ded0e52363 LD_DUMP_REL_PRE and LD_DUMP_REL_POST don't output to stderr; don't
claim that they do.
2003-06-19 04:34:09 +00:00
Matthew N. Dodd
c5d061c17a Provide a mechanism for dumping relocation information.
Setting the LD_DUMP_REL_PRE or LD_DUMP_REL_POST environment variables
cause rtld-elf to output a table of all relocations.

This is useful for debugging.
2003-06-19 03:55:38 +00:00
Ruslan Ermilov
09f84dd1d3 Assorted mdoc(7) fixes. 2003-06-02 15:02:06 +00:00
Matthew N. Dodd
4df60d1cac Use the environment variable LD_LIBMAP_DISABLE to disable
libmap.conf(5) functionality.
2003-05-31 14:45:11 +00:00
Robert Watson
94deb3f034 Since libmap.conf is referenced in rtld.1, include it in the references
section.

Approved by:	re (scottl)
2003-05-17 19:46:49 +00:00
Ruslan Ermilov
60cdf2f1a0 mdoc(7) police: Normalize the FILES section.
Approved by:	re (blanket)
2003-05-16 21:34:21 +00:00
Matthew N. Dodd
29ade36225 Dynamic object dependency mapping: libmap.
This is an optional feature, disabled by default.

This will be useful to people testing the various POSIX threading
libraries under -CURRENT but can easily serve other needs.
2003-04-07 16:21:26 +00:00
Alexey Zelkin
d9943f166b Advertize rtld(1) as ld.so(1) in manual pages world 2003-02-13 23:07:28 +00:00
Ruslan Ermilov
8d5d039f80 Uniformly refer to a file system as "file system".
Approved by:	re
2002-12-12 17:26:04 +00:00
Philippe Charnier
3f162cb85d The .Nm utility 2002-07-06 19:19:48 +00:00
David E. O'Brien
2024994319 Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a
non-empty string in the environment; we indicate which objects caused
each object to be loaded.

PR:		30908
Submitted-by:	Mike Meyer <mwm@mired.org>
2002-02-17 07:04:32 +00:00
Ruslan Ermilov
bcf2b1b312 mdoc(7) police: tidy up. 2002-01-10 17:49:57 +00:00
Ruslan Ermilov
c4d9468ea0 mdoc(7) police:
Avoid using parenthesis enclosure macros (.Pq and .Po/.Pc) with plain text.
Not only this slows down the mdoc(7) processing significantly, but it also
has an undesired (in this case) effect of disabling hyphenation within the
entire enclosed block.
2001-08-07 15:48:51 +00:00
Ruslan Ermilov
0efe23d669 mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 10:49:54 +00:00
Dima Dorfman
70d51341bf mdoc(7) police: remove extraneous .Pp before and/or after .Sh. 2001-07-09 09:54:33 +00:00
Ruslan Ermilov
5521ff5a4d mdoc(7) police: sort SEE ALSO xrefs (sort -b -f +2 -3 +1 -2). 2001-07-06 16:46:48 +00:00
Ruslan Ermilov
896eb7d10c Prepare for mdoc(7)NG. 2001-01-16 09:15:57 +00:00
Ruslan Ermilov
58eaff2332 Prepare for mdoc(7)NG. 2000-12-20 13:26:01 +00:00
Sheldon Hearn
cbe10916b3 Only punctuation is an allowed argument type for open-close macros
such as Po/Pc, as explained by phantom.

Reported by:	billf
2000-06-30 06:30:53 +00:00
Sheldon Hearn
35add0e9a7 Cross-reference ldd(1) in rtld(1) and vice versa. 2000-03-28 09:01:04 +00:00
John Polstra
ea5cc7f114 Add a manual page for the ELF dynamic linker. I initially created
rtld.1 by means of a repository copy from "src/libexec/rtld-aout/rtld.1".
Then I edited it to make it (more) accurate for the ELF dynamic
linker.
2000-01-29 03:16:54 +00:00
Alexey Zelkin
8bd2d9a0e6 .Nm += "rtld"
apropos(1) now knows about rtld(1) manpage.
1999-09-28 05:35:59 +00:00
Peter Wemm
7f3dea244c $Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00
Wolfram Schneider
f6b31571f6 spelling corrections.
PR: docs/4450
Submitted by: josh@quick.net
1997-09-13 16:01:53 +00:00
Masafumi Max NAKANE
d5fb0dffb4 Typo fix.
PR:		3693
Submitted by:	Kazuo Horikawa <k-horik@yk.rim.or.jp>
1997-05-27 13:46:40 +00:00
Peter Wemm
fce15c9ab3 Revert $FreeBSD$ to $Id$ 1997-02-22 15:48:31 +00:00
John Polstra
ac6c268b3d Pay attention to the environment variable "LD_IGNORE_MISSING_OBJECTS".
If it is set to a nonempty string, then simply skip any missing
shared libraries.  This came up in a discussion long ago as a
potentially useful feature at sysinstall time.  For example, an
X11 utility could be used without the X libraries being present,
provided the utility had a mode in which no X functions were actually
called.
1997-01-17 20:22:18 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Wolfram Schneider
af20215665 Sort cross references. 1997-01-13 00:25:51 +00:00
John Polstra
aeea55e459 Correct typos and spelling errors. 1997-01-12 00:19:14 +00:00
John Polstra
0db65949ae Add support for the LD_BIND_NOW environment variable. If it is set to a
nonempty string, then function calls are relocated at program start-up
rather than lazily.  This variable is standard on Sun and SVR4 systems.

The dlopen() function now supports both lazy and immediate binding, as
determined by its "mode" argument, which can be either 1 (RTLD_LAZY) or
2 (RTLD_NOW).  I will add defines of these symbols to <dlfcn.h> as soon
as I've done a little more checking to make sure they won't cause
collisions or bootstrapping problems that would break "make world".

The "LD_*" environment variables which alter dynamic linker behavior are
now treated as unset if they are set to the empty string.  This agrees
with the standard SVR4 conventions for the dynamic linker.

Add a work-around for programs compiled with certain buggy versions of
crt0.o.  The buggy versions failed to set the "crt_ldso" member of the
interface structure.  This caused certain error messages from the
dynamic linker to begin with "(null)" instead of the pathname of the
dynamic linker.
1997-01-12 00:16:36 +00:00
Steven Wallace
43d7fd0390 Fix spelling error in manpage. 1996-12-26 21:51:09 +00:00
John Polstra
16804804df Fix two minor typos in the manual page. 1996-10-18 04:49:43 +00:00
Peter Wemm
5584286a91 Update to handle new version ld.so.hints and info in executable for
configurable fallback search paths, as well as new crt interface version.

Also:
 - even faster getenv(), get all environment variable settings in a single
   pass.
 - ldd printf-like format specifications
 - minor code cleanups, one vsprintf -> vsnprintf (harmless)

The library search sequence is a little more complete now. Before,
it'd search $LD_LIBRARY_PATH (by opendir/readdir/closedir), then read
the hints file, then read /usr/lib (again by scanning thr directory).  It
would then fail if there was no "found" library.

Now, it does LD_LIBRARY_PATH and the hints file the same, but then uses
a longer fallback path.  The -R path is fetched from the executable if
specified at build time, the ldconfig path is appended, and /usr/lib is
appended to that. Duplicates are suppressed.  This means that simply
placing a new library in /usr/local/lib will work (the same as it did in
/usr/lib) without needing ldconfig -m.  It will find it quicker if the
ldconfig is run though.

Similar changes have been made to the NetBSD ld.so, but ours is rather
different now due to John Polstra's speedups and fixes from a while back.

The ldd printf-like format support came direct from NetBSD.

Reviewed by: nate, jdp
1996-10-01 01:52:03 +00:00