xref: /freebsd/sys/kern/kern_module.c (revision 0640d357f29fb1c0daaaffadd0416c5981413afd)
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 1.10 1998/10/10 00:03:07 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 
41 typedef TAILQ_HEAD(, module) modulelist_t;
42 struct 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 
55 static modulelist_t modules;
56 static int nextid = 1;
57 
58 static void module_shutdown(int, void*);
59 
60 static void
61 module_init(void* arg)
62 {
63     TAILQ_INIT(&modules);
64     at_shutdown(module_shutdown, 0, SHUTDOWN_POST_SYNC);
65 }
66 
67 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0);
68 
69 static void
70 module_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 
78 void
79 module_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) returned %d",
87 	       data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error);
88 }
89 
90 int
91 module_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 
129 void
130 module_reference(module_t mod)
131 {
132     MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
133 
134     mod->refs++;
135 }
136 
137 void
138 module_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 
155 module_t
156 module_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 
168 module_t
169 module_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 
181 int
182 module_unload(module_t mod)
183 {
184     return MOD_EVENT(mod, MOD_UNLOAD);
185 }
186 
187 int
188 module_getid(module_t mod)
189 {
190     return mod->id;
191 }
192 
193 module_t
194 module_getfnext(module_t mod)
195 {
196     return TAILQ_NEXT(mod, flink);
197 }
198 
199 /*
200  * Syscalls.
201  */
202 int
203 modnext(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 
228 int
229 modfnext(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 
246 int
247 modstat(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 
284 out:
285     return error;
286 }
287 
288 int
289 modfind(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 
304 out:
305     return error;
306 }
307