xref: /freebsd/sys/kern/kern_module.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
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 1.1 1997/05/07 16:05:31 dfr Exp $
27  */
28 
29 #include <sys/param.h>
30 #include <sys/kernel.h>
31 #include <sys/systm.h>
32 #include <sys/queue.h>
33 #include <sys/malloc.h>
34 #include <sys/sysproto.h>
35 #include <sys/sysent.h>
36 #include <sys/module.h>
37 #include <sys/linker.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_KMEM, SI_ORDER_ANY, module_init, 0);
68 
69 static void
70 module_shutdown(int arg1, void* arg2)
71 {
72     module_t mod;
73     int error;
74 
75     for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link))
76 	MOD_EVENT(mod, MOD_SHUTDOWN);
77 }
78 
79 void
80 module_register_static(void *arg)
81 {
82     moduledata_t* data = (moduledata_t*) arg;
83     int error;
84 
85     if (error = module_register(data->name, data->evhand, data->priv))
86 	printf("module_register_static: module_register(%s, %x, %x) returned %d",
87 	       data->name, data->evhand, data->priv, error);
88 }
89 
90 int
91 module_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 
125 void
126 module_reference(module_t mod)
127 {
128     MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
129 
130     mod->refs++;
131 }
132 
133 void
134 module_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 
151 module_t
152 module_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 
164 module_t
165 module_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 
177 int
178 module_unload(module_t mod)
179 {
180     return MOD_EVENT(mod, MOD_UNLOAD);
181 }
182 
183 int
184 module_getid(module_t mod)
185 {
186     return mod->id;
187 }
188 
189 module_t
190 module_getfnext(module_t mod)
191 {
192     return TAILQ_NEXT(mod, flink);
193 }
194 
195 /*
196  * Syscalls.
197  */
198 int
199 modnext(struct proc* p, struct modnext_args* uap, int* retval)
200 {
201     module_t mod;
202 
203     *retval = -1;
204     if (SCARG(uap, modid) == 0) {
205 	mod = TAILQ_FIRST(&modules);
206 	if (mod) {
207 	    *retval = 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 	*retval = TAILQ_NEXT(mod, link)->id;
219     else
220 	*retval = 0;
221     return 0;
222 }
223 
224 int
225 modfnext(struct proc* p, struct modfnext_args* uap, int* retval)
226 {
227     module_t mod;
228 
229     *retval = -1;
230 
231     mod = module_lookupbyid(SCARG(uap, modid));
232     if (!mod)
233 	return ENOENT;
234 
235     if (TAILQ_NEXT(mod, flink))
236 	*retval = TAILQ_NEXT(mod, flink)->id;
237     else
238 	*retval = 0;
239     return 0;
240 }
241 
242 int
243 modstat(struct proc* p, struct modstat_args* uap, int* retval)
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     *retval = 0;
279 
280 out:
281     return error;
282 }
283 
284 int
285 modfind(struct proc* p, struct modfind_args* uap, int* retval)
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 	*retval = mod->id;
299 
300 out:
301     return error;
302 }
303