1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2016 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 (rnrs io ports)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (ice-9 vlist)
#:use-module (ice-9 match)
#:export (dot-ko
ensure-dot-ko
module-dependencies
recursive-module-dependencies
modules-loaded
module-loaded?
load-linux-module*
current-module-debugging-port))
;;; 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* ((modinfo (elf-section-by-name elf ".modinfo"))
(contents (make-bytevector (elf-section-size modinfo))))
(bytevector-copy! (elf-bytes elf) (elf-section-offset modinfo)
contents 0
(elf-section-size modinfo))
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))
(modinfo (section-contents elf ".modinfo")))
(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 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 (file-name->module-name file)
"Return the module name corresponding to FILE, stripping the trailing '.ko',
etc."
(basename file ".ko"))
(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."
(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 (slurp module)
;; TODO: Use 'finit_module' to reduce memory usage.
(call-with-input-file file get-bytevector-all))
(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)
(map lookup-module dependencies))))
(and (not (black-listed? (file-name->module-name file)))
(or (not recursive?)
(load-dependencies file))
(begin
(format (current-module-debugging-port)
"loading Linux module from '~a'...~%" file)
(catch 'system-error
(lambda ()
(load-linux-module (slurp file)))
(lambda args
;; If this module was already loaded and we're in modprobe style, ignore
;; the error.
(or (and recursive? (= EEXIST (system-error-errno args)))
(apply throw args)))))))
;;; linux-modules.scm ends here
|
