kmod/man/modprobe.d.xml
Michal Suchanek 8463809f8a libkmod, depmod: Load modprobe.d, depmod.d from ${prefix}/lib.
There is an ongoing effort to limit use of files outside of /usr (or
${prefix} on general). Currently all modprobe.d paths are hardcoded to
outside of $prefix. Teach kmod to load modprobe.d from ${prefix}/lib.

On some distributions /usr/lib and /lib are the same directory because
of a compatibility symlink, and it is possible to craft configuration
files with sideeffects that would behave differently when loaded twice.
However, the override semantic ensures that one 'overrides' the other,
and only one configuration file of the same name is loaded from any of
the search directories.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Link: https://lore.kernel.org/r/a290343ce32e2a3c25b134e4f27c13b26e06c9e0.1689681454.git.msuchanek@suse.de
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
2023-10-17 12:27:59 -05:00

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<?xml version="1.0"?>
<!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<refentry id="modprobe.d">
<refentryinfo>
<title>modprobe.d</title>
<productname>kmod</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Jon</firstname>
<surname>Masters</surname>
<email>jcm@jonmasters.org</email>
</author>
<author>
<contrib>Developer</contrib>
<firstname>Robby</firstname>
<surname>Workman</surname>
<email>rworkman@slackware.com</email>
</author>
<author>
<contrib>Developer</contrib>
<firstname>Lucas</firstname>
<surname>De Marchi</surname>
<email>lucas.de.marchi@gmail.com</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>modprobe.d</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>modprobe.d</refname>
<refpurpose>Configuration directory for modprobe</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>/lib/modprobe.d/*.conf</filename></para>
<para><filename>@DISTCONFDIR@/modprobe.d/*.conf</filename></para>
<para><filename>/usr/local/lib/modprobe.d/*.conf</filename></para>
<para><filename>/run/modprobe.d/*.conf</filename></para>
<para><filename>/etc/modprobe.d/*.conf</filename></para>
</refsynopsisdiv>
<refsect1><title>DESCRIPTION</title>
<para>Because the <command>modprobe</command> command can add or
remove more than one module, due to modules having dependencies,
we need a method of specifying what options are to be used with
those modules. All files underneath the
<filename>/etc/modprobe.d</filename> directory which end with the
<filename>.conf</filename> extension specify those options as
required. They can also be used to create convenient aliases:
alternate names for a module, or they can override the normal
<command>modprobe</command> behavior altogether for those with
special requirements (such as inserting more than one module).
</para>
<para>
Note that module and alias names (like other module names) can
have - or _ in them: both are interchangeable throughout all the
module commands as underscore conversion happens automatically.
</para>
<para>
The format of files under <filename>modprobe.d</filename> is
simple: one command per line, with blank lines and lines starting
with '#' ignored (useful for adding comments). A '\' at the end
of a line causes it to continue on the next line, which makes the
file a bit neater.
</para>
</refsect1>
<refsect1><title>COMMANDS</title>
<variablelist>
<varlistentry>
<term>alias <replaceable>wildcard</replaceable> <replaceable>modulename</replaceable>
</term>
<listitem>
<para>
This allows you to give alternate names for a module. For example:
"alias my-mod really_long_modulename" means you can use "modprobe
my-mod" instead of "modprobe really_long_modulename". You can also
use shell-style wildcards, so "alias my-mod*
really_long_modulename" means that "modprobe my-mod-something" has
the same effect. You can't have aliases to other aliases (that way
lies madness), but aliases can have options, which will be added to
any other options.
</para>
<para>
Note that modules can also contain their own aliases, which you can
see using <command>modinfo</command>. These aliases are used as a
last resort (ie. if there is no real module,
<command>install</command>, <command>remove</command>, or
<command>alias</command> command in the configuration).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>blacklist <replaceable>modulename</replaceable>
</term>
<listitem>
<para>
Modules can contain their own aliases: usually these are aliases
describing the devices they support, such as "pci:123...". These
"internal" aliases can be overridden by normal "alias" keywords,
but there are cases where two or more modules both support the same
devices, or a module invalidly claims to support a device that it
does not: the <command>blacklist</command> keyword indicates that
all of that particular module's internal aliases are to be ignored.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>install <replaceable>modulename</replaceable> <replaceable>command...</replaceable>
</term>
<listitem>
<para>
This command instructs <command>modprobe</command> to run your
command instead of inserting the module in the kernel as normal.
The command can be any shell command: this allows you to do any
kind of complex processing you might wish. For example, if the
module "fred" works better with the module "barney" already
installed (but it doesn't depend on it, so
<command>modprobe</command> won't automatically load it), you could
say "install fred /sbin/modprobe barney; /sbin/modprobe
--ignore-install fred", which would do what you wanted. Note the
<option>--ignore-install</option>, which stops the second
<command>modprobe</command> from running the same
<command>install</command> command again. See also
<command>remove</command> below. </para> <para>The long term
future of this command as a solution to the problem of providing
additional module dependencies is not assured and it is intended to
replace this command with a warning about its eventual removal or
deprecation at some point in a future release. Its use complicates
the automated determination of module dependencies by distribution
utilities, such as mkinitrd (because these now need to somehow
interpret what the <command>install</command> commands might be
doing. In a perfect world, modules would provide all dependency
information without the use of this command and work is underway to
implement soft dependency support within the Linux kernel. </para>
<para> If you use the string "$CMDLINE_OPTS" in the command, it will
be replaced by any options specified on the modprobe command line.
This can be useful because users expect "modprobe fred opt=1" to
pass the "opt=1" arg to the module, even if there's an install
command in the configuration file. So our above example becomes
"install fred /sbin/modprobe barney; /sbin/modprobe
--ignore-install fred $CMDLINE_OPTS"
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>options <replaceable>modulename</replaceable> <replaceable>option...</replaceable>
</term>
<listitem>
<para>
This command allows you to add options to the module
<replaceable>modulename</replaceable> (which might be an
alias) every time it is inserted into the kernel: whether
directly (using <command>modprobe </command>
<replaceable>modulename</replaceable>) or because the
module being inserted depends on this module.
</para>
<para>
All options are added together: they can come from an
<command>option</command> for the module itself, for an
alias, and on the command line.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>remove <replaceable>modulename</replaceable> <replaceable>command...</replaceable>
</term>
<listitem>
<para>
This is similar to the <command>install</command> command
above, except it is invoked when "modprobe -r" is run.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>softdep <replaceable>modulename</replaceable> pre: <replaceable>modules...</replaceable> post: <replaceable>modules...</replaceable>
</term>
<listitem>
<para>
The <command>softdep</command> command allows you to specify soft,
or optional, module dependencies. <replaceable>modulename</replaceable>
can be used without these optional modules installed, but usually with
some features missing. For example, a driver for a storage HBA might
require another module be loaded in order to use management features.
</para>
<para>
pre-deps and post-deps modules are lists of names and/or aliases of other
modules that modprobe will attempt to install (or remove) in order
before and after the main module given in the
<replaceable>modulename</replaceable> argument.
</para>
<para>
Example: Assume "softdep c pre: a b post: d e" is provided in the
configuration. Running "modprobe c" is now equivalent to
"modprobe a b c d e" without the softdep.
Flags such as --use-blacklist are applied to all the specified
modules, while module parameters only apply to module c.
</para>
<para>
Note: if there are <command>install</command> or
<command>remove</command> commands with the same
<replaceable>modulename</replaceable> argument,
<command>softdep</command> takes precedence.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1><title>COMPATIBILITY</title>
<para>
A future version of kmod will come with a strong warning to avoid use of
the <command>install</command> as explained above. This will happen once
support for soft dependencies in the kernel is complete. That support
will complement the existing softdep support within this utility by
providing such dependencies directly within the modules.
</para>
</refsect1>
<refsect1><title>COPYRIGHT</title>
<para>
This manual page originally Copyright 2004, Rusty Russell, IBM
Corporation. Maintained by Jon Masters and others.
</para>
</refsect1>
<refsect1><title>SEE ALSO</title>
<para><citerefentry>
<refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>modules.dep</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>
</para>
</refsect1>
</refentry>