xref: /freebsd/sys/kern/kern_module.c (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a)
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 1.13 1999/01/09 14:59:50 dfr 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     modspecific_t	data;		/* module specific data */
52 };
53 
54 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg)
55 
56 static modulelist_t modules;
57 static int nextid = 1;
58 
59 static void module_shutdown(int, void*);
60 
61 static void
62 module_init(void* arg)
63 {
64     TAILQ_INIT(&modules);
65     at_shutdown(module_shutdown, 0, SHUTDOWN_POST_SYNC);
66 }
67 
68 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0);
69 
70 static void
71 module_shutdown(int arg1, void* arg2)
72 {
73     module_t mod;
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_init(void *arg)
81 {
82     moduledata_t* data = (moduledata_t*) arg;
83     int error;
84 
85     error = module_register(data->name, data->evhand, data->priv, data->_file);
86     if (error)
87 	printf("module_register_init: module_register(%s, %lx, %p) error %d\n",
88 	       data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error);
89 }
90 
91 int
92 module_register(const char* name, modeventhand_t handler, void* arg, void *file)
93 {
94     size_t namelen;
95     module_t newmod;
96     int error;
97     linker_file_t container = file;
98 
99     namelen = strlen(name) + 1;
100     newmod = (module_t) malloc(sizeof(struct module) + namelen,
101 			       M_MODULE, M_WAITOK);
102     if (newmod == 0)
103 	return ENOMEM;
104 
105     newmod->refs = 1;
106     newmod->id = nextid++;
107     newmod->name = (char *) (newmod + 1);
108     strcpy(newmod->name, name);
109     newmod->handler = handler;
110     newmod->arg = arg;
111     bzero(&newmod->data, sizeof(newmod->data));
112     TAILQ_INSERT_TAIL(&modules, newmod, link);
113 
114     if (container == NULL)
115 	container = linker_current_file;
116     if (container) {
117 	TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
118 	newmod->file = container;
119     } else
120 	newmod->file = 0;
121 
122     if (error = MOD_EVENT(newmod, MOD_LOAD)) {
123 	MOD_EVENT(newmod, MOD_UNLOAD);
124 	module_release(newmod);
125 	return error;
126     }
127 
128     return 0;
129 }
130 
131 void
132 module_reference(module_t mod)
133 {
134     MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
135 
136     mod->refs++;
137 }
138 
139 void
140 module_release(module_t mod)
141 {
142     if (mod->refs <= 0)
143 	panic("module_release: bad reference count");
144 
145     MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
146 
147     mod->refs--;
148     if (mod->refs == 0) {
149 	TAILQ_REMOVE(&modules, mod, link);
150 	if (mod->file) {
151 	    TAILQ_REMOVE(&mod->file->modules, mod, flink);
152 	}
153 	free(mod, M_MODULE);
154     }
155 }
156 
157 module_t
158 module_lookupbyname(const char* name)
159 {
160     module_t mod;
161 
162     for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
163 	if (!strcmp(mod->name, name))
164 	    return mod;
165     }
166 
167     return 0;
168 }
169 
170 module_t
171 module_lookupbyid(int modid)
172 {
173     module_t mod;
174 
175     for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
176 	if (mod->id == modid)
177 	    return mod;
178     }
179 
180     return 0;
181 }
182 
183 int
184 module_unload(module_t mod)
185 {
186     return MOD_EVENT(mod, MOD_UNLOAD);
187 }
188 
189 int
190 module_getid(module_t mod)
191 {
192     return mod->id;
193 }
194 
195 module_t
196 module_getfnext(module_t mod)
197 {
198     return TAILQ_NEXT(mod, flink);
199 }
200 
201 void
202 module_setspecific(module_t mod, modspecific_t *datap)
203 {
204     mod->data = *datap;
205 }
206 
207 /*
208  * Syscalls.
209  */
210 int
211 modnext(struct proc* p, struct modnext_args* uap)
212 {
213     module_t mod;
214 
215     p->p_retval[0] = -1;
216     if (SCARG(uap, modid) == 0) {
217 	mod = TAILQ_FIRST(&modules);
218 	if (mod) {
219 	    p->p_retval[0] = mod->id;
220 	    return 0;
221 	} else
222 	    return ENOENT;
223     }
224 
225     mod = module_lookupbyid(SCARG(uap, modid));
226     if (!mod)
227 	return ENOENT;
228 
229     if (TAILQ_NEXT(mod, link))
230 	p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
231     else
232 	p->p_retval[0] = 0;
233     return 0;
234 }
235 
236 int
237 modfnext(struct proc* p, struct modfnext_args* uap)
238 {
239     module_t mod;
240 
241     p->p_retval[0] = -1;
242 
243     mod = module_lookupbyid(SCARG(uap, modid));
244     if (!mod)
245 	return ENOENT;
246 
247     if (TAILQ_NEXT(mod, flink))
248 	p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
249     else
250 	p->p_retval[0] = 0;
251     return 0;
252 }
253 
254 struct module_stat_v1 {
255     int		version;	/* set to sizeof(struct module_stat) */
256     char	name[MAXMODNAME];
257     int		refs;
258     int		id;
259 };
260 
261 int
262 modstat(struct proc* p, struct modstat_args* uap)
263 {
264     module_t mod;
265     int error = 0;
266     int namelen;
267     int version;
268     struct module_stat* stat;
269 
270     mod = module_lookupbyid(SCARG(uap, modid));
271     if (!mod)
272 	return ENOENT;
273 
274     stat = SCARG(uap, stat);
275 
276     /*
277      * Check the version of the user's structure.
278      */
279     if (error = copyin(&stat->version, &version, sizeof(version)))
280 	goto out;
281     if (version != sizeof(struct module_stat_v1)
282 	&& version != sizeof(struct module_stat)) {
283 	error = EINVAL;
284 	goto out;
285     }
286 
287     namelen = strlen(mod->name) + 1;
288     if (namelen > MAXMODNAME)
289 	namelen = MAXMODNAME;
290     if (error = copyout(mod->name, &stat->name[0], namelen))
291 	goto out;
292 
293     if (error = copyout(&mod->refs, &stat->refs, sizeof(int)))
294 	goto out;
295     if (error = copyout(&mod->id, &stat->id, sizeof(int)))
296 	goto out;
297 
298     /*
299      * >v1 stat includes module data.
300      */
301     if (version == sizeof(struct module_stat)) {
302 	if (error = copyout(&mod->data, &stat->data, sizeof(mod->data)))
303 	    goto out;
304     }
305 
306     p->p_retval[0] = 0;
307 
308 out:
309     return error;
310 }
311 
312 int
313 modfind(struct proc* p, struct modfind_args* uap)
314 {
315     int error = 0;
316     char name[MAXMODNAME];
317     module_t mod;
318 
319     if (error = copyinstr(SCARG(uap, name), name, sizeof name, 0))
320 	goto out;
321 
322     mod = module_lookupbyname(name);
323     if (!mod)
324 	error = ENOENT;
325     else
326 	p->p_retval[0] = mod->id;
327 
328 out:
329     return error;
330 }
331