xref: /freebsd/sys/kern/kern_module.c (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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 1.17 1999/05/08 13:01:57 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     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(const void *arg)
81 {
82     const moduledata_t* data = (const moduledata_t*) arg;
83     int error;
84     module_t mod;
85 
86     mod = module_lookupbyname(data->name);
87     if (mod == NULL) {
88 #if 0
89 	panic("module_register_init: module named %s not found\n", data->name);
90 #else
91 	/* temporary kludge until kernel `file' attachment registers modules */
92 	error = module_register(data, linker_kernel_file);
93 	if (error)
94 	    panic("module_register_init: register of module failed! %d", error);
95 	mod = module_lookupbyname(data->name);
96 	if (mod == NULL)
97 	    panic("module_register_init: module STILL not found!");
98 #endif
99     }
100     error = MOD_EVENT(mod, MOD_LOAD);
101     if (error) {
102 	MOD_EVENT(mod, MOD_UNLOAD);
103 	module_release(mod);
104 	printf("module_register_init: MOD_LOAD (%s, %lx, %p) error %d\n",
105 	       data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error);
106     }
107 }
108 
109 int
110 module_register(const moduledata_t *data, linker_file_t container)
111 {
112     size_t namelen;
113     module_t newmod;
114 
115     newmod = module_lookupbyname(data->name);
116     if (newmod != NULL) {
117 	printf("module_register: module %s already exists!\n", data->name);
118 	return EEXIST;
119     }
120     namelen = strlen(data->name) + 1;
121     newmod = (module_t) malloc(sizeof(struct module) + namelen,
122 			       M_MODULE, M_WAITOK);
123     if (newmod == 0)
124 	return ENOMEM;
125 
126     newmod->refs = 1;
127     newmod->id = nextid++;
128     newmod->name = (char *) (newmod + 1);
129     strcpy(newmod->name, data->name);
130     newmod->handler = data->evhand;
131     newmod->arg = data->priv;
132     bzero(&newmod->data, sizeof(newmod->data));
133     TAILQ_INSERT_TAIL(&modules, newmod, link);
134 
135     if (container == NULL)
136 	container = linker_current_file;
137     if (container)
138 	TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
139     newmod->file = container;
140 
141     return 0;
142 }
143 
144 void
145 module_reference(module_t mod)
146 {
147     MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
148 
149     mod->refs++;
150 }
151 
152 void
153 module_release(module_t mod)
154 {
155     if (mod->refs <= 0)
156 	panic("module_release: bad reference count");
157 
158     MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
159 
160     mod->refs--;
161     if (mod->refs == 0) {
162 	TAILQ_REMOVE(&modules, mod, link);
163 	if (mod->file) {
164 	    TAILQ_REMOVE(&mod->file->modules, mod, flink);
165 	}
166 	free(mod, M_MODULE);
167     }
168 }
169 
170 module_t
171 module_lookupbyname(const char* name)
172 {
173     module_t mod;
174 
175     for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
176 	if (!strcmp(mod->name, name))
177 	    return mod;
178     }
179 
180     return 0;
181 }
182 
183 module_t
184 module_lookupbyid(int modid)
185 {
186     module_t mod;
187 
188     for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
189 	if (mod->id == modid)
190 	    return mod;
191     }
192 
193     return 0;
194 }
195 
196 int
197 module_unload(module_t mod)
198 {
199     return MOD_EVENT(mod, MOD_UNLOAD);
200 }
201 
202 int
203 module_getid(module_t mod)
204 {
205     return mod->id;
206 }
207 
208 module_t
209 module_getfnext(module_t mod)
210 {
211     return TAILQ_NEXT(mod, flink);
212 }
213 
214 void
215 module_setspecific(module_t mod, modspecific_t *datap)
216 {
217     mod->data = *datap;
218 }
219 
220 /*
221  * Syscalls.
222  */
223 int
224 modnext(struct proc* p, struct modnext_args* uap)
225 {
226     module_t mod;
227 
228     p->p_retval[0] = -1;
229     if (SCARG(uap, modid) == 0) {
230 	mod = TAILQ_FIRST(&modules);
231 	if (mod) {
232 	    p->p_retval[0] = mod->id;
233 	    return 0;
234 	} else
235 	    return ENOENT;
236     }
237 
238     mod = module_lookupbyid(SCARG(uap, modid));
239     if (!mod)
240 	return ENOENT;
241 
242     if (TAILQ_NEXT(mod, link))
243 	p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
244     else
245 	p->p_retval[0] = 0;
246     return 0;
247 }
248 
249 int
250 modfnext(struct proc* p, struct modfnext_args* uap)
251 {
252     module_t mod;
253 
254     p->p_retval[0] = -1;
255 
256     mod = module_lookupbyid(SCARG(uap, modid));
257     if (!mod)
258 	return ENOENT;
259 
260     if (TAILQ_NEXT(mod, flink))
261 	p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
262     else
263 	p->p_retval[0] = 0;
264     return 0;
265 }
266 
267 struct module_stat_v1 {
268     int		version;	/* set to sizeof(struct module_stat) */
269     char	name[MAXMODNAME];
270     int		refs;
271     int		id;
272 };
273 
274 int
275 modstat(struct proc* p, struct modstat_args* uap)
276 {
277     module_t mod;
278     int error = 0;
279     int namelen;
280     int version;
281     struct module_stat* stat;
282 
283     mod = module_lookupbyid(SCARG(uap, modid));
284     if (!mod)
285 	return ENOENT;
286 
287     stat = SCARG(uap, stat);
288 
289     /*
290      * Check the version of the user's structure.
291      */
292     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
293 	goto out;
294     if (version != sizeof(struct module_stat_v1)
295 	&& version != sizeof(struct module_stat)) {
296 	error = EINVAL;
297 	goto out;
298     }
299 
300     namelen = strlen(mod->name) + 1;
301     if (namelen > MAXMODNAME)
302 	namelen = MAXMODNAME;
303     if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0)
304 	goto out;
305 
306     if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0)
307 	goto out;
308     if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0)
309 	goto out;
310 
311     /*
312      * >v1 stat includes module data.
313      */
314     if (version == sizeof(struct module_stat)) {
315 	if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0)
316 	    goto out;
317     }
318 
319     p->p_retval[0] = 0;
320 
321 out:
322     return error;
323 }
324 
325 int
326 modfind(struct proc* p, struct modfind_args* uap)
327 {
328     int error = 0;
329     char name[MAXMODNAME];
330     module_t mod;
331 
332     if ((error = copyinstr(SCARG(uap, name), name, sizeof name, 0)) != 0)
333 	goto out;
334 
335     mod = module_lookupbyname(name);
336     if (!mod)
337 	error = ENOENT;
338     else
339 	p->p_retval[0] = mod->id;
340 
341 out:
342     return error;
343 }
344