me
/
guix
Archived
1
0
Fork 0
This repository has been archived on 2024-08-07. You can view files and clone it, but cannot push or open issues/pull-requests.
guix/gnu/build/linux-modules.scm

467 lines
17 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2016, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu build linux-modules)
#:use-module (guix elf)
#:use-module (guix glob)
#:use-module (guix build syscalls)
#:use-module ((guix build utils) #:select (find-files))
#:use-module (rnrs io ports)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (ice-9 vlist)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:export (dot-ko
ensure-dot-ko
module-aliases
module-dependencies
module-soft-dependencies
normalize-module-name
file-name->module-name
find-module-file
recursive-module-dependencies
modules-loaded
module-loaded?
load-linux-module*
current-module-debugging-port
device-module-aliases
known-module-aliases
matching-modules))
;;; Commentary:
;;;
;;; Tools to deal with Linux kernel modules.
;;;
;;; Code:
(define current-module-debugging-port
(make-parameter (%make-void-port "w")))
(define (section-contents elf section)
"Return the contents of SECTION in ELF as a bytevector."
(let ((contents (make-bytevector (elf-section-size section))))
(bytevector-copy! (elf-bytes elf) (elf-section-offset section)
contents 0
(elf-section-size section))
contents))
(define %not-nul
(char-set-complement (char-set #\nul)))
(define (nul-separated-string->list str)
"Split STR at occurrences of the NUL character and return the resulting
string list."
(string-tokenize str %not-nul))
(define (key=value->pair str)
"Assuming STR has the form \"KEY=VALUE\", return a pair like (KEY
. \"VALUE\")."
(let ((= (string-index str #\=)))
(cons (string->symbol (string-take str =))
(string-drop str (+ 1 =)))))
(define (modinfo-section-contents file)
"Return the contents of the '.modinfo' section of FILE as a list of
key/value pairs.."
(let* ((bv (call-with-input-file file get-bytevector-all))
(elf (parse-elf bv))
(section (elf-section-by-name elf ".modinfo"))
(modinfo (section-contents elf section)))
(map key=value->pair
(nul-separated-string->list (utf8->string modinfo)))))
(define %not-comma
(char-set-complement (char-set #\,)))
(define (module-dependencies file)
"Return the list of modules that FILE depends on. The returned list
contains module names, not actual file names."
(let ((info (modinfo-section-contents file)))
(match (assq 'depends info)
(('depends . what)
(string-tokenize what %not-comma)))))
(define not-softdep-whitespace
(char-set-complement (char-set #\space #\tab)))
(define (module-soft-dependencies file)
"Return the list of modules that can be preloaded, and then the list of
modules that can be postloaded, of the soft dependencies of module FILE."
;; TEXT: "pre: baz blubb foo post: bax bar"
(define (parse-softdep text)
(let loop ((value '())
(tokens (string-tokenize text not-softdep-whitespace))
(section #f))
(match tokens
((token rest ...)
(if (string=? (string-take-right token 1) ":") ; section
(loop value rest (string-trim-both (string-drop-right token 1)))
(loop (cons (cons section token) value) rest section)))
(()
value))))
;; Note: Multiple 'softdep sections are allowed.
(let* ((info (modinfo-section-contents file))
(entries (concatenate
(filter-map (match-lambda
(('softdep . value)
(parse-softdep value))
(_ #f))
(modinfo-section-contents file)))))
(let-values (((pres posts)
(partition (match-lambda
(("pre" . _) #t)
(("post" . _) #f))
entries)))
(values (map (match-lambda
((_ . value) value))
pres)
(map (match-lambda
((_ . value) value))
posts)))))
(define (module-aliases file)
"Return the list of aliases of module FILE."
(let ((info (modinfo-section-contents file)))
(filter-map (match-lambda
(('alias . value)
value)
(_ #f))
(modinfo-section-contents file))))
(define dot-ko
(cut string-append <> ".ko"))
(define (ensure-dot-ko name)
"Return NAME with a '.ko' prefix appended, unless it already has it."
(if (string-suffix? ".ko" name)
name
(dot-ko name)))
(define (normalize-module-name module)
"Return the \"canonical\" name for MODULE, replacing hyphens with
underscores."
;; See 'modname_normalize' in libkmod.
(string-map (lambda (chr)
(case chr
((#\-) #\_)
(else chr)))
module))
(define (file-name->module-name file)
"Return the module name corresponding to FILE, stripping the trailing '.ko'
and normalizing it."
(normalize-module-name (basename file ".ko")))
(define (find-module-file directory module)
"Lookup module NAME under DIRECTORY, and return its absolute file name.
NAME can be a file name with or without '.ko', or it can be a module name.
Raise an error if it could not be found.
Module names can differ from file names in interesting ways; for instance,
module names usually (always?) use underscores as the inter-word separator,
whereas file names often, but not always, use hyphens. Examples:
\"usb-storage.ko\", \"serpent_generic.ko\"."
(define names
;; List of possible file names. XXX: It would of course be cleaner to
;; have a database that maps module names to file names and vice versa,
;; but everyone seems to be doing hacks like this one. Oh well!
(map ensure-dot-ko
(delete-duplicates
(list module
(normalize-module-name module)
(string-map (lambda (chr) ;converse of 'normalize-module-name'
(case chr
((#\_) #\-)
(else chr)))
module)))))
(match (find-files directory
(lambda (file stat)
(member (basename file) names)))
((file)
file)
(()
(error "kernel module not found" module directory))
((_ ...)
(error "several modules by that name" module directory))))
(define* (recursive-module-dependencies files
#:key (lookup-module dot-ko))
"Return the topologically-sorted list of file names of the modules depended
on by FILES, recursively. File names of modules are determined by applying
LOOKUP-MODULE to the module name."
(let loop ((files files)
(result '())
(visited vlist-null))
(match files
(()
(delete-duplicates (reverse result)))
((head . tail)
(let* ((visited? (vhash-assoc head visited))
(deps (if visited?
'()
(map lookup-module (module-dependencies head))))
(visited (if visited?
visited
(vhash-cons head #t visited))))
(loop (append deps tail)
(append result deps) visited))))))
(define %not-newline
(char-set-complement (char-set #\newline)))
(define (modules-loaded)
"Return the list of names of currently loaded Linux modules."
(let* ((contents (call-with-input-file "/proc/modules"
get-string-all))
(lines (string-tokenize contents %not-newline)))
(match (map string-tokenize lines)
(((modules . _) ...)
modules))))
(define (module-black-list)
"Return the black list of modules that must not be loaded. This black list
is specified using 'modprobe.blacklist=MODULE1,MODULE2,...' on the kernel
command line; it is honored by libkmod for users that pass
'KMOD_PROBE_APPLY_BLACKLIST', which includes 'modprobe --use-blacklist' and
udev."
(define parameter
"modprobe.blacklist=")
(let ((command (call-with-input-file "/proc/cmdline"
get-string-all)))
(append-map (lambda (arg)
(if (string-prefix? parameter arg)
(string-tokenize (string-drop arg (string-length parameter))
%not-comma)
'()))
(string-tokenize command))))
(define (module-loaded? module)
"Return #t if MODULE is already loaded. MODULE must be a Linux module name,
not a file name."
(member module (modules-loaded)))
(define* (load-linux-module* file
#:key
(recursive? #t)
(lookup-module dot-ko)
(black-list (module-black-list)))
"Load Linux module from FILE, the name of a '.ko' file; return true on
success, false otherwise. When RECURSIVE? is true, load its dependencies
first (à la 'modprobe'.) The actual files containing modules depended on are
obtained by calling LOOKUP-MODULE with the module name. Modules whose name
appears in BLACK-LIST are not loaded."
(define (black-listed? module)
(let ((result (member module black-list)))
(when result
(format (current-module-debugging-port)
"not loading module '~a' because it's black-listed~%"
module))
result))
(define (load-dependencies file)
(let ((dependencies (module-dependencies file)))
(every (cut load-linux-module* <>
#:lookup-module lookup-module
#:black-list black-list)
(map lookup-module dependencies))))
(and (not (black-listed? (file-name->module-name file)))
(or (not recursive?)
(load-dependencies file))
(let ((fd #f))
(format (current-module-debugging-port)
"loading Linux module from '~a'...~%" file)
(catch 'system-error
(lambda ()
(set! fd (open-fdes file O_RDONLY))
(load-linux-module/fd fd)
(close-fdes fd)
#t)
(lambda args
;; If this module was already loaded and we're in modprobe style, ignore
;; the error.
(when fd (close-fdes fd))
(or (and recursive? (= EEXIST (system-error-errno args)))
(apply throw args)))))))
;;;
;;; Device modules.
;;;
;; Copied from (guix utils). FIXME: Factorize.
(define (readlink* file)
"Call 'readlink' until the result is not a symlink."
(define %max-symlink-depth 50)
(let loop ((file file)
(depth 0))
(define (absolute target)
(if (absolute-file-name? target)
target
(string-append (dirname file) "/" target)))
(if (>= depth %max-symlink-depth)
file
(call-with-values
(lambda ()
(catch 'system-error
(lambda ()
(values #t (readlink file)))
(lambda args
(let ((errno (system-error-errno args)))
(if (or (= errno EINVAL))
(values #f file)
(apply throw args))))))
(lambda (success? target)
(if success?
(loop (absolute target) (+ depth 1))
file))))))
;; See 'major' and 'minor' in <sys/sysmacros.h>.
(define (stat->device-major st)
(ash (logand #xfff00 (stat:rdev st)) -8))
(define (stat->device-minor st)
(logand #xff (stat:rdev st)))
(define %not-slash
(char-set-complement (char-set #\/)))
(define (read-uevent port)
"Read a /sys 'uevent' file from PORT and return an alist where each car is a
key such as 'MAJOR or 'DEVTYPE and each cdr is the corresponding value."
(let loop ((result '()))
(match (read-line port)
((? eof-object?)
(reverse result))
(line
(loop (cons (key=value->pair line) result))))))
(define (device-module-aliases device)
"Return the list of module aliases required by DEVICE, a /dev file name, as
in this example:
(device-module-aliases \"/dev/sda\")
=> (\"scsi:t-0x00\" \"pci:v00008086d00009D03sv0000103Csd000080FAbc01sc06i01\")
The modules corresponding to these aliases can then be found using
'matching-modules'."
;; The approach is adapted from
;; <https://unix.stackexchange.com/questions/97676/how-to-find-the-driver-module-associated-with-a-device-on-linux>.
(let* ((st (stat device))
(type (stat:type st))
(major (stat->device-major st))
(minor (stat->device-minor st))
(sys-name (string-append "/sys/dev/"
(case type
((block-special) "block")
((char-special) "char")
(else (symbol->string type)))
"/" (number->string major) ":"
(number->string minor)))
(directory (canonicalize-path (readlink* sys-name))))
(let loop ((components (string-tokenize directory %not-slash))
(aliases '()))
(match components
(("sys" "devices" _)
(reverse aliases))
((head ... _)
(let ((uevent (string-append (string-join components "/" 'prefix)
"/uevent")))
(if (file-exists? uevent)
(let ((props (call-with-input-file uevent read-uevent)))
(match (assq-ref props 'MODALIAS)
(#f (loop head aliases))
(alias (loop head (cons alias aliases)))))
(loop head aliases))))))))
(define (read-module-aliases port)
"Read from PORT data in the Linux 'modules.alias' file format. Return a
list of alias/module pairs where each alias is a glob pattern as like the
result of:
(string->compiled-sglob \"scsi:t-0x01*\")
and each module is a module name like \"snd_hda_intel\"."
(define (comment? str)
(string-prefix? "#" str))
(define (tokenize str)
;; Lines have the form "alias ALIAS MODULE", where ALIAS can contain
;; whitespace. This is why we don't use 'string-tokenize'.
(let* ((str (string-trim-both str))
(left (string-index str #\space))
(right (string-rindex str #\space)))
(list (string-take str left)
(string-trim-both (substring str left right))
(string-trim-both (string-drop str right)))))
(let loop ((aliases '()))
(match (read-line port)
((? eof-object?)
(reverse aliases))
((? comment?)
(loop aliases))
(line
(match (tokenize line)
(("alias" alias module)
(loop (alist-cons (string->compiled-sglob alias) module
aliases)))
(() ;empty line
(loop aliases)))))))
(define (current-kernel-directory)
"Return the directory of the currently running Linux kernel."
(string-append (or (getenv "LINUX_MODULE_DIRECTORY")
"/run/booted-system/kernel/lib/modules")
"/" (utsname:release (uname))))
(define (current-alias-file)
"Return the absolute file name of the default 'modules.alias' file."
(string-append (current-kernel-directory) "/modules.alias"))
(define* (known-module-aliases #:optional (alias-file (current-alias-file)))
"Return the list of alias/module pairs read from ALIAS-FILE. Each alias is
actually a pattern."
(call-with-input-file alias-file read-module-aliases))
(define* (matching-modules alias
#:optional (known-aliases (known-module-aliases)))
"Return the list of modules that match ALIAS according to KNOWN-ALIASES.
ALIAS is a string like \"scsi:t-0x00\" as returned by
'device-module-aliases'."
(filter-map (match-lambda
((pattern . module)
(and (glob-match? pattern alias)
module)))
known-aliases))
;;; linux-modules.scm ends here