kern_module.c revision 40945 
1/*-
2 * Copyright (c) 1997 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	$Id: kern_module.c,v 1.11 1998/10/16 03:55:00 peter Exp $
27 */
28
29#include <sys/param.h>
30#include <sys/kernel.h>
31#include <sys/systm.h>
32#include <sys/malloc.h>
33#include <sys/sysproto.h>
34#include <sys/sysent.h>
35#include <sys/module.h>
36#include <sys/linker.h>
37#include <sys/proc.h>
38
39#define M_MODULE	M_TEMP		/* XXX */
40
41typedef TAILQ_HEAD(, module) modulelist_t;
42struct module {
43    TAILQ_ENTRY(module)	link;		/* chain together all modules */
44    TAILQ_ENTRY(module)	flink;		/* all modules in a file */
45    struct linker_file*	file;		/* file which contains this module */
46    int			refs;		/* reference count */
47    int			id;		/* unique id number */
48    char		*name;		/* module name */
49    modeventhand_t	handler;	/* event handler */
50    void		*arg;		/* argument for handler */
51};
52
53#define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg)
54
55static modulelist_t modules;
56static int nextid = 1;
57
58static void module_shutdown(int, void*);
59
60static void
61module_init(void* arg)
62{
63    TAILQ_INIT(&modules);
64    at_shutdown(module_shutdown, 0, SHUTDOWN_POST_SYNC);
65}
66
67SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0);
68
69static void
70module_shutdown(int arg1, void* arg2)
71{
72    module_t mod;
73
74    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link))
75	MOD_EVENT(mod, MOD_SHUTDOWN);
76}
77
78void
79module_register_init(void *arg)
80{
81    moduledata_t* data = (moduledata_t*) arg;
82    int error;
83
84    error = module_register(data->name, data->evhand, data->priv, data->_file);
85    if (error)
86	printf("module_register_init: module_register(%s, %lx, %p) error %d\n",
87	       data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error);
88}
89
90int
91module_register(const char* name, modeventhand_t handler, void* arg, void *file)
92{
93    size_t namelen;
94    module_t newmod;
95    int error;
96    linker_file_t container = file;
97
98    namelen = strlen(name) + 1;
99    newmod = (module_t) malloc(sizeof(struct module) + namelen,
100			       M_MODULE, M_WAITOK);
101    if (newmod == 0)
102	return ENOMEM;
103
104    newmod->refs = 1;
105    newmod->id = nextid++;
106    newmod->name = (char *) (newmod + 1);
107    strcpy(newmod->name, name);
108    newmod->handler = handler;
109    newmod->arg = arg;
110    TAILQ_INSERT_TAIL(&modules, newmod, link);
111
112    if (container == NULL)
113	container = linker_current_file;
114    if (container) {
115	TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
116	newmod->file = container;
117    } else
118	newmod->file = 0;
119
120    if (error = MOD_EVENT(newmod, MOD_LOAD)) {
121	MOD_EVENT(newmod, MOD_UNLOAD);
122	module_release(newmod);
123	return error;
124    }
125
126    return 0;
127}
128
129void
130module_reference(module_t mod)
131{
132    MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
133
134    mod->refs++;
135}
136
137void
138module_release(module_t mod)
139{
140    if (mod->refs <= 0)
141	panic("module_release: bad reference count");
142
143    MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
144
145    mod->refs--;
146    if (mod->refs == 0) {
147	TAILQ_REMOVE(&modules, mod, link);
148	if (mod->file) {
149	    TAILQ_REMOVE(&mod->file->modules, mod, flink);
150	}
151	free(mod, M_MODULE);
152    }
153}
154
155module_t
156module_lookupbyname(const char* name)
157{
158    module_t mod;
159
160    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
161	if (!strcmp(mod->name, name))
162	    return mod;
163    }
164
165    return 0;
166}
167
168module_t
169module_lookupbyid(int modid)
170{
171    module_t mod;
172
173    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
174	if (mod->id == modid)
175	    return mod;
176    }
177
178    return 0;
179}
180
181int
182module_unload(module_t mod)
183{
184    return MOD_EVENT(mod, MOD_UNLOAD);
185}
186
187int
188module_getid(module_t mod)
189{
190    return mod->id;
191}
192
193module_t
194module_getfnext(module_t mod)
195{
196    return TAILQ_NEXT(mod, flink);
197}
198
199/*
200 * Syscalls.
201 */
202int
203modnext(struct proc* p, struct modnext_args* uap)
204{
205    module_t mod;
206
207    p->p_retval[0] = -1;
208    if (SCARG(uap, modid) == 0) {
209	mod = TAILQ_FIRST(&modules);
210	if (mod) {
211	    p->p_retval[0] = mod->id;
212	    return 0;
213	} else
214	    return ENOENT;
215    }
216
217    mod = module_lookupbyid(SCARG(uap, modid));
218    if (!mod)
219	return ENOENT;
220
221    if (TAILQ_NEXT(mod, link))
222	p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
223    else
224	p->p_retval[0] = 0;
225    return 0;
226}
227
228int
229modfnext(struct proc* p, struct modfnext_args* uap)
230{
231    module_t mod;
232
233    p->p_retval[0] = -1;
234
235    mod = module_lookupbyid(SCARG(uap, modid));
236    if (!mod)
237	return ENOENT;
238
239    if (TAILQ_NEXT(mod, flink))
240	p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
241    else
242	p->p_retval[0] = 0;
243    return 0;
244}
245
246int
247modstat(struct proc* p, struct modstat_args* uap)
248{
249    module_t mod;
250    int error = 0;
251    int namelen;
252    int version;
253    struct module_stat* stat;
254
255    mod = module_lookupbyid(SCARG(uap, modid));
256    if (!mod)
257	return ENOENT;
258
259    stat = SCARG(uap, stat);
260
261    /*
262     * Check the version of the user's structure.
263     */
264    if (error = copyin(&stat->version, &version, sizeof(version)))
265	goto out;
266    if (version != sizeof(struct module_stat)) {
267	error = EINVAL;
268	goto out;
269    }
270
271    namelen = strlen(mod->name) + 1;
272    if (namelen > MAXMODNAME)
273	namelen = MAXMODNAME;
274    if (error = copyout(mod->name, &stat->name[0], namelen))
275	goto out;
276
277    if (error = copyout(&mod->refs, &stat->refs, sizeof(int)))
278	goto out;
279    if (error = copyout(&mod->id, &stat->id, sizeof(int)))
280	goto out;
281
282    p->p_retval[0] = 0;
283
284out:
285    return error;
286}
287
288int
289modfind(struct proc* p, struct modfind_args* uap)
290{
291    int error = 0;
292    char name[MAXMODNAME];
293    module_t mod;
294
295    if (error = copyinstr(SCARG(uap, name), name, sizeof name, 0))
296	goto out;
297
298    mod = module_lookupbyname(name);
299    if (!mod)
300	error = ENOENT;
301    else
302	p->p_retval[0] = mod->id;
303
304out:
305    return error;
306}
307