kern_module.c revision 31016 
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 1.5 1997/11/06 19:29:11 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    if (error = module_register(data->name, data->evhand, data->priv))
85	printf("module_register_init: module_register(%s, %x, %x) returned %d",
86	       data->name, data->evhand, data->priv, error);
87}
88
89int
90module_register(const char* name, modeventhand_t handler, void* arg)
91{
92    size_t namelen;
93    module_t newmod;
94    int error;
95
96    namelen = strlen(name) + 1;
97    newmod = (module_t) malloc(sizeof(struct module) + namelen,
98			       M_MODULE, M_WAITOK);
99    if (newmod == 0)
100	return ENOMEM;
101
102    newmod->refs = 1;
103    newmod->id = nextid++;
104    newmod->name = (char *) (newmod + 1);
105    strcpy(newmod->name, name);
106    newmod->handler = handler;
107    newmod->arg = arg;
108    TAILQ_INSERT_TAIL(&modules, newmod, link);
109
110    if (linker_current_file) {
111	TAILQ_INSERT_TAIL(&linker_current_file->modules, newmod, flink);
112	newmod->file = linker_current_file;
113    } else
114	newmod->file = 0;
115
116    if (error = MOD_EVENT(newmod, MOD_LOAD)) {
117	module_release(newmod);
118	return error;
119    }
120
121    return 0;
122}
123
124void
125module_reference(module_t mod)
126{
127    MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
128
129    mod->refs++;
130}
131
132void
133module_release(module_t mod)
134{
135    if (mod->refs <= 0)
136	panic("module_release: bad reference count");
137
138    MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
139
140    mod->refs--;
141    if (mod->refs == 0) {
142	TAILQ_REMOVE(&modules, mod, link);
143	if (mod->file) {
144	    TAILQ_REMOVE(&mod->file->modules, mod, flink);
145	}
146	free(mod, M_MODULE);
147    }
148}
149
150module_t
151module_lookupbyname(const char* name)
152{
153    module_t mod;
154
155    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
156	if (!strcmp(mod->name, name))
157	    return mod;
158    }
159
160    return 0;
161}
162
163module_t
164module_lookupbyid(int modid)
165{
166    module_t mod;
167
168    for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
169	if (mod->id == modid)
170	    return mod;
171    }
172
173    return 0;
174}
175
176int
177module_unload(module_t mod)
178{
179    return MOD_EVENT(mod, MOD_UNLOAD);
180}
181
182int
183module_getid(module_t mod)
184{
185    return mod->id;
186}
187
188module_t
189module_getfnext(module_t mod)
190{
191    return TAILQ_NEXT(mod, flink);
192}
193
194/*
195 * Syscalls.
196 */
197int
198modnext(struct proc* p, struct modnext_args* uap)
199{
200    module_t mod;
201
202    p->p_retval[0] = -1;
203    if (SCARG(uap, modid) == 0) {
204	mod = TAILQ_FIRST(&modules);
205	if (mod) {
206	    p->p_retval[0] = mod->id;
207	    return 0;
208	} else
209	    return ENOENT;
210    }
211
212    mod = module_lookupbyid(SCARG(uap, modid));
213    if (!mod)
214	return ENOENT;
215
216    if (TAILQ_NEXT(mod, link))
217	p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
218    else
219	p->p_retval[0] = 0;
220    return 0;
221}
222
223int
224modfnext(struct proc* p, struct modfnext_args* uap)
225{
226    module_t mod;
227
228    p->p_retval[0] = -1;
229
230    mod = module_lookupbyid(SCARG(uap, modid));
231    if (!mod)
232	return ENOENT;
233
234    if (TAILQ_NEXT(mod, flink))
235	p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
236    else
237	p->p_retval[0] = 0;
238    return 0;
239}
240
241int
242modstat(struct proc* p, struct modstat_args* uap)
243{
244    module_t mod;
245    int error = 0;
246    int namelen;
247    int version;
248    struct module_stat* stat;
249
250    mod = module_lookupbyid(SCARG(uap, modid));
251    if (!mod)
252	return ENOENT;
253
254    stat = SCARG(uap, stat);
255
256    /*
257     * Check the version of the user's structure.
258     */
259    if (error = copyin(&stat->version, &version, sizeof(version)))
260	goto out;
261    if (version != sizeof(struct module_stat)) {
262	error = EINVAL;
263	goto out;
264    }
265
266    namelen = strlen(mod->name) + 1;
267    if (namelen > MAXMODNAME)
268	namelen = MAXMODNAME;
269    if (error = copyout(mod->name, &stat->name[0], namelen))
270	goto out;
271
272    if (error = copyout(&mod->refs, &stat->refs, sizeof(int)))
273	goto out;
274    if (error = copyout(&mod->id, &stat->id, sizeof(int)))
275	goto out;
276
277    p->p_retval[0] = 0;
278
279out:
280    return error;
281}
282
283int
284modfind(struct proc* p, struct modfind_args* uap)
285{
286    int error = 0;
287    char name[MAXMODNAME];
288    module_t mod;
289
290    if (error = copyinstr(SCARG(uap, name), name, sizeof name, 0))
291	goto out;
292
293    mod = module_lookupbyname(name);
294    if (!mod)
295	error = ENOENT;
296    else
297	p->p_retval[0] = mod->id;
298
299out:
300    return error;
301}
302