modprobe (8)





NAME

       modprobe - high level handling of loadable modules


SYNOPSIS

       modprobe [-adnqv] [-C config] module [symbol=value ...]
       modprobe [-adnqv] [-C config] [-t type] pattern
       modprobe -l [-C config] [-t type] pattern
       modprobe -c [-C config]
       modprobe -r [-dnv] [-C config] [module ...]
       modprobe -Vh


OPTIONS

       -a, --all
              Load  all  matching  modules instead of stopping after the first
              successful loading.

       -c, --showconfig
              Show the currently used configuration.

       -C, --config config
              Use the file config instead of (the optional)  /etc/modules.conf
              to   specify   the   configuration.   The  environment  variable
              MODULECONF can also be used to select (and override) a different
              configuration   file  from  the  default  /etc/modules.conf  (or
              /etc/conf.modules (deprecated)).

       When environment variable UNAME_MACHINE is set, modutils will  use  its
       value  instead  of the machine field from the uname() syscall.  This is
       mainly of use when you are compiling 64 bit  modules  in  32  bit  user
       space  or  vice  versa,  set  UNAME_MACHINE to the type of the modules.
       Current modutils does not support full cross build mode for modules, it
       is  limited  to  choosing  between  32  and 64 bit versions of the host
       architecture.

       -d, --debug
              Show information about the internal representation of the  stack
              of modules.

       -h, --help
              Display a summary of options and immediately exit.

       -k, --autoclean
              Set  'autoclean'  on loaded modules.  Used by the kernel when it
              calls on modprobe to satisfy a missing feature  (supplied  as  a
              module).   The  -q  option is implied by -k.  These options will
              automatically be sent to insmod.

       -l, --list
              List matching modules.

       -n, --show
              Don't actually perform the action, just show what would be done.

       -q, --quiet
              Do  not  complain  about  insmod  failing  to  install a module.
              Report   via  syslog  instead  of  stderr.   This  options  will
              automatically be sent to insmod.

       -t moduletype; --type moduletype
              Only consider modules of this type.  modprobe will only look  at
              modules  whose  directory  path includes exactly "/moduletype/".
              moduletype can  include  more  than  one  directory  name,  e.g.
              "-t drivers/net"  would list modules in xxx/drivers/net/ and its
              subdirectories.

       -v, --verbose
              Print all commands as they are executed.

       -V, --version
              Display the version of modprobe.

       Note:  Module names must not contain  paths  (no  '/'),  nor  may  they
              contain  the trailing '.o'.  For example, slip is a valid module
              name for modprobe, /lib/modules/2.2.19/net/slip and  slip.o  are
              invalid.  This applies to the command line and to entries in the
              config.


DESCRIPTION

       The modprobe and depmod utilities are intended to make a Linux  modular
       kernel  more  manageable for all users, administrators and distribution
       maintainers.

       Modprobe uses a "Makefile"-like dependency file, created by depmod,  to
       automatically  load  the  relevant  module(s)  from  the set of modules
       available in predefined directory trees.

       Modprobe is used to load a single module, a stack of dependent modules,
       or all modules that are marked with a specified tag.

       Modprobe  will  automatically  load all base modules needed in a module
       stack, as described by the dependency file modules.dep.  If the loading
       of  one  of  these  modules  fails,  the whole current stack of modules
       loaded in the current session will be unloaded automatically.

       Modprobe has two ways of loading modules. One way (the probe mode) will
       try  to  load  a  module  out of a list (defined by pattern).  Modprobe
       stops loading as soon as one module loads successfully.  This could  be
       used to autoload one Ethernet driver out of a list.
       The  other way modprobe can be used is to load all modules from a list.
       See EXAMPLES, below.

       With the option -r, modprobe  will  automatically  unload  a  stack  of
       modules,  similar  to  the  way  "rmmod  -r" does. Note that using just
       "modprobe -r" will clean up unused autoloaded modules and also  perform
       the   pre-   and   post-remove   commands  in  the  configuration  file
       /etc/modules.conf.

       The combining the options -l and -t lists all available  modules  of  a
       certain type.

       Option  -c  will  print  the  currently  used  configuration (default +
       configuration file).
       module is "autocleaned" by kerneld!  Look for the up-coming support for
       persistent module storage instead.
       If you want to use the pre- and post-install features, you will have to
       turn off autoclean for kerneld  and  instead  put  something  like  the
       following  line in your crontab (this is used for kmod systems as well)
       to do autoclean every 2 minutes:
        */2 * * * * test -f /proc/modules && /sbin/modprobe -r


STRATEGY

       The idea is that modprobe will look first in the  directory  containing
       modules  compiled for the current release of the kernel.  If the module
       is not found there, modprobe will look in the directory common  to  the
       kernel version (e.g. 2.0, 2.2).  If the module is still found, modprobe
       will look in the directory containing modules for  a  default  release,
       and so on.

       When  you  install  a  new  linux,  the  modules  should  be moved to a
       directory related to the release (and version) of the  kernel  you  are
       installing.   Then  you  should do a symlink from this directory to the
       "default" directory.

       Each time you compile a new kernel, the command "make  modules_install"
       will create a new directory, but won't change the "default" link.

       When  you  get a module unrelated to the kernel distribution you should
       place  it  in  one  of  the   version-independent   directories   under
       /lib/modules.

       This   is   the   default   strategy,   which   can  be  overridden  in
       /etc/modules.conf.


EXAMPLES

       modprobe -t net
              Load one of the modules that are stored in the directory  tagged
              "net".  Each module are tried until one succeeds.

       modprobe -a -t boot
              All modules that are stored in directories tagged "boot" will be
              loaded.

       modprobe slip
              This will attempt to load  the  module  slhc.o  if  it  was  not
              previously loaded, since the slip module needs the functionality
              in the slhc module.  This dependency will be  described  in  the
              file modules.dep that was created automatically by depmod.

       modprobe -r slip
              This  will unload the slip module.  It will also unload the slhc
              module automatically, unless it is used by some other module  as
              well (e.g. ppp).


FILES

       /etc/modules.conf (alternatively but deprecated /etc/conf.modules)
       /lib/modules/*/modules.dep,
       /lib/modules/*


SEE ALSO

       data read from the config file.

       euid  may not be equal to uid when modprobe is invoked from the kernel,
       this is true for kernels >= 2.4.0-test11.  In an ideal world,  modprobe
       could  trust  the  kernel  to  only  pass valid parameters to modprobe.
       However at least one local root exploit has occurred because high level
       kernel  code  passed  unverified  parameters  direct  from  the user to
       modprobe.  So modprobe no longer trusts kernel input.

       modprobe automatically sets safe mode  when  the  environment  consists
       only of these strings
        HOME=/
        TERM=linux
        PATH=/sbin:/usr/sbin:/bin:/usr/bin
       This  detects  modprobe execution from the kernel on kernels 2.2 though
       2.4.0-test11, even if uid  ==  euid,  which  it  does  on  the  earlier
       kernels.


LOGGING COMMANDS

       If  directory  /var/log/ksymoops  exists  and  modprobe  is run with an
       option that could load or a delete a module then modprobe will log  its
       command  and  return  status  in  /var/log/ksymoops/`date +%Y%m%d.log`.
       There is no switch to disable this automatic logging,  if  you  do  not
       want  it  to occur, do not create /var/log/ksymoops.  If that directory
       exists, it should be owned by root and be  mode  644  or  600  and  you
       should run script insmod_ksymoops_clean every day or so.


REQUIRED UTILITIES

       depmod(8), insmod(8).


NOTES

       Patterns  supplied  to modprobe will often need to be escaped to ensure
       that it is evaluated in the proper context.


BUGS

       modprobe [ -V | --version  ]  should  exit  immediately.   Instead,  it
       prints the version information and behaves as if no options were given.


AUTHOR

       Jacques Gelinas (jack@solucorp.qc.ca)
       Bjorn Ekwall (bj0rn@blox.se)

Linux                          February 4, 2002                    modprobe(8)