kern_module.c revision 37555 
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 1.6 1997/11/07 08:52:56 phk 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_KMEM, SI_ORDER_ANY, 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#define	fptrint_t	unsigned	/* XXX */
85    if (error = module_register(data->name, data->evhand, data->priv))
86	printf("module_register_init: module_register(%s, %lx, %p) returned %d",
87	       data->name, (u_long)(fptrint_t)data->evhand, data->priv, error);
88}
89
90int
91module_register(const char* name, modeventhand_t handler, void* arg)
92{
93    size_t namelen;
94    module_t newmod;
95    int error;
96
97    namelen = strlen(name) + 1;
98    newmod = (module_t) malloc(sizeof(struct module) + namelen,
99			       M_MODULE, M_WAITOK);
100    if (newmod == 0)
101	return ENOMEM;
102
103    newmod->refs = 1;
104    newmod->id = nextid++;
105    newmod->name = (char *) (newmod + 1);
106    strcpy(newmod->name, name);
107    newmod->handler = handler;
108    newmod->arg = arg;
109    TAILQ_INSERT_TAIL(&modules, newmod, link);
110
111    if (linker_current_file) {
112	TAILQ_INSERT_TAIL(&linker_current_file->modules, newmod, flink);
113	newmod->file = linker_current_file;
114    } else
115	newmod->file = 0;
116
117    if (error = MOD_EVENT(newmod, MOD_LOAD)) {
118	module_release(newmod);
119	return error;
120    }
121
122    return 0;
123}
124
125void
126module_reference(module_t mod)
127{
128    MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
129
130    mod->refs++;
131}
132
133void
134module_release(module_t mod)
135{
136    if (mod->refs <= 0)
137	panic("module_release: bad reference count");
138
139    MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
140
141    mod->refs--;
142    if (mod->refs == 0) {
143	TAILQ_REMOVE(&modules, mod, link);
144	if (mod->file) {
145	    TAILQ_REMOVE(&mod->file->modules, mod, flink);
146	}
147	free(mod, M_MODULE);
148    }
149}
150
151module_t
152module_lookupbyname(const char* name)
153{
154    module_t mod;
155
156    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
157	if (!strcmp(mod->name, name))
158	    return mod;
159    }
160
161    return 0;
162}
163
164module_t
165module_lookupbyid(int modid)
166{
167    module_t mod;
168
169    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
170	if (mod->id == modid)
171	    return mod;
172    }
173
174    return 0;
175}
176
177int
178module_unload(module_t mod)
179{
180    return MOD_EVENT(mod, MOD_UNLOAD);
181}
182
183int
184module_getid(module_t mod)
185{
186    return mod->id;
187}
188
189module_t
190module_getfnext(module_t mod)
191{
192    return TAILQ_NEXT(mod, flink);
193}
194
195/*
196 * Syscalls.
197 */
198int
199modnext(struct proc* p, struct modnext_args* uap)
200{
201    module_t mod;
202
203    p->p_retval[0] = -1;
204    if (SCARG(uap, modid) == 0) {
205	mod = TAILQ_FIRST(&modules);
206	if (mod) {
207	    p->p_retval[0] = mod->id;
208	    return 0;
209	} else
210	    return ENOENT;
211    }
212
213    mod = module_lookupbyid(SCARG(uap, modid));
214    if (!mod)
215	return ENOENT;
216
217    if (TAILQ_NEXT(mod, link))
218	p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
219    else
220	p->p_retval[0] = 0;
221    return 0;
222}
223
224int
225modfnext(struct proc* p, struct modfnext_args* uap)
226{
227    module_t mod;
228
229    p->p_retval[0] = -1;
230
231    mod = module_lookupbyid(SCARG(uap, modid));
232    if (!mod)
233	return ENOENT;
234
235    if (TAILQ_NEXT(mod, flink))
236	p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
237    else
238	p->p_retval[0] = 0;
239    return 0;
240}
241
242int
243modstat(struct proc* p, struct modstat_args* uap)
244{
245    module_t mod;
246    int error = 0;
247    int namelen;
248    int version;
249    struct module_stat* stat;
250
251    mod = module_lookupbyid(SCARG(uap, modid));
252    if (!mod)
253	return ENOENT;
254
255    stat = SCARG(uap, stat);
256
257    /*
258     * Check the version of the user's structure.
259     */
260    if (error = copyin(&stat->version, &version, sizeof(version)))
261	goto out;
262    if (version != sizeof(struct module_stat)) {
263	error = EINVAL;
264	goto out;
265    }
266
267    namelen = strlen(mod->name) + 1;
268    if (namelen > MAXMODNAME)
269	namelen = MAXMODNAME;
270    if (error = copyout(mod->name, &stat->name[0], namelen))
271	goto out;
272
273    if (error = copyout(&mod->refs, &stat->refs, sizeof(int)))
274	goto out;
275    if (error = copyout(&mod->id, &stat->id, sizeof(int)))
276	goto out;
277
278    p->p_retval[0] = 0;
279
280out:
281    return error;
282}
283
284int
285modfind(struct proc* p, struct modfind_args* uap)
286{
287    int error = 0;
288    char name[MAXMODNAME];
289    module_t mod;
290
291    if (error = copyinstr(SCARG(uap, name), name, sizeof name, 0))
292	goto out;
293
294    mod = module_lookupbyname(name);
295    if (!mod)
296	error = ENOENT;
297    else
298	p->p_retval[0] = mod->id;
299
300out:
301    return error;
302}
303