207 lines
6.4 KiB
Groff
207 lines
6.4 KiB
Groff
.\"
|
|
.\" Copyright (c) 1993 Paul Kranenburg
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by Paul Kranenburg.
|
|
.\" 3. The name of the author may not be used to endorse or promote products
|
|
.\" derived from this software without specific prior written permission
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd October 3, 1993
|
|
.Dt LDCONFIG 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ldconfig
|
|
.Nd configure the shared library cache
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl aout | Fl elf
|
|
.Op Fl Rimrsv
|
|
.Op Fl f Ar hints_file
|
|
.Op Ar directory | Ar
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility is used to prepare a set of
|
|
.Dq hints
|
|
for use by the dynamic linker
|
|
to facilitate quick lookup of shared libraries available in multiple
|
|
directories. It scans a set of built-in system directories and any
|
|
.Ar directories
|
|
specified on the command line (in the given order) looking for
|
|
shared libraries and stores the results in a system file to forestall
|
|
the overhead that would otherwise result from the directory search
|
|
operations the dynamic linker would have to perform to load the
|
|
required shared libraries.
|
|
.Pp
|
|
Files named on the command line are expected to contain directories
|
|
to scan for shared libraries. Each directory's pathname must start on a new
|
|
line. Blank lines and lines starting with the comment character
|
|
.Ql \&#
|
|
are ignored.
|
|
Filenames must conform to the
|
|
.Pa lib*.so.[0-9]
|
|
pattern in order to be added to the hints file.
|
|
.Pp
|
|
For security reasons, directories which are world or group-writable or which
|
|
are not owned by root produce warning messages and are skipped, unless
|
|
the
|
|
.Fl i
|
|
option is present.
|
|
.Pp
|
|
The shared libraries which are found will be automatically available for loading
|
|
if needed by the program being prepared for execution.
|
|
This obviates the need
|
|
for storing search paths within the executable.
|
|
.Pp
|
|
The
|
|
.Ev LD_LIBRARY_PATH
|
|
environment variable can be used to override the use of
|
|
directories (or the order thereof) from the cache or to specify additional
|
|
directories where shared libraries might be found.
|
|
.Ev LD_LIBRARY_PATH
|
|
is a
|
|
.Sq \&:
|
|
separated list of directory paths which are searched by
|
|
the dynamic linker
|
|
when it needs to load a shared library.
|
|
It can be viewed as the run-time
|
|
equivalent of the
|
|
.Fl L
|
|
switch of
|
|
.Xr ld 1 .
|
|
.Pp
|
|
The
|
|
.Nm
|
|
utility is typically run as part of the boot sequence.
|
|
.Pp
|
|
The following options are recognized by
|
|
.Nm :
|
|
.Bl -tag -width indent
|
|
.It Fl aout
|
|
Generate the hints for a.out format shared libraries.
|
|
.It Fl elf
|
|
Generate the hints for ELF format shared libraries.
|
|
.It Fl R
|
|
Rescan the previously configured directories. This opens the previous hints
|
|
file and fetches the directory list from the header. Any additional pathnames
|
|
on the command line are also processed.
|
|
This is the default action when no parameters are given.
|
|
.It Fl f Ar hints_file
|
|
Read and/or update the specified hints file, instead of the standard file.
|
|
This option is provided primarily for testing.
|
|
.It Fl i
|
|
Run in insecure mode. The security checks will not be performed.
|
|
.It Fl m
|
|
Instead of replacing the contents of the hints file
|
|
with those found in the directories specified,
|
|
.Dq merge
|
|
in new entries.
|
|
Directories recorded in the hints file by previous runs of
|
|
.Nm
|
|
are also rescanned for new shared libraries.
|
|
.It Fl r
|
|
List the current contents of the hints file
|
|
on the standard output.
|
|
The hints file is not modified. The list of
|
|
directories stored in the hints file is included.
|
|
.It Fl s
|
|
Do not scan the built-in system directory
|
|
.Pq Dq /usr/lib
|
|
for shared libraries.
|
|
.It Fl v
|
|
Switch on verbose mode.
|
|
.El
|
|
.Sh SECURITY
|
|
Special care must be taken when loading shared libraries into the address
|
|
space of
|
|
.Ev set-user-Id
|
|
programs.
|
|
Whenever such a program is run by any user except the owner of the program,
|
|
the dynamic linker
|
|
will only load shared libraries from the hints
|
|
file.
|
|
In particular, the
|
|
.Ev LD_LIBRARY_PATH
|
|
is not used to search for libraries.
|
|
Thus, the role of ldconfig is dual.
|
|
In
|
|
addition to building a set of hints for quick lookup, it also serves to
|
|
specify the trusted collection of directories from which shared objects can
|
|
be safely loaded.
|
|
.Sh ENVIRONMENT
|
|
.Bl -tag -width OBJFORMATxxx -compact
|
|
.It Ev OBJFORMAT
|
|
Overrides
|
|
.Pa /etc/objformat
|
|
(see below) to determine whether
|
|
.Fl aout
|
|
or
|
|
.Fl elf
|
|
is the default. If set, its value should be either
|
|
.Ql aout
|
|
or
|
|
.Ql elf .
|
|
.El
|
|
.Sh FILES
|
|
.Bl -tag -width /var/run/ld-elf.so.hintsxxx -compact
|
|
.It Pa /var/run/ld.so.hints
|
|
Standard hints file for the a.out dynamic linker.
|
|
.It Pa /var/run/ld-elf.so.hints
|
|
Standard hints file for the ELF dynamic linker.
|
|
.It Pa /etc/ld.so.conf
|
|
Conventional configuration file containing directory names for
|
|
invocations with
|
|
.Fl aout .
|
|
.It Pa /etc/ld-elf.so.conf
|
|
Conventional configuration file containing directory names for
|
|
invocations with
|
|
.Fl elf .
|
|
.It Pa /etc/objformat
|
|
Determines whether
|
|
.Fl aout
|
|
or
|
|
.Fl elf
|
|
is the default. If present, it must consist of a single line
|
|
containing either
|
|
.Ql OBJFORMAT=aout
|
|
or
|
|
.Ql OBJFORMAT=elf .
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr ld 1 ,
|
|
.Xr link 5
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
utility first appeared in SunOS 4.0, it appeared in its current form
|
|
in
|
|
.Fx 1.1 .
|
|
.Sh BUGS
|
|
Some security checks (for example, verifying root ownership of
|
|
added directories) are not performed when
|
|
.Fl aout
|
|
is specified.
|