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
27 #include "opt_compat.h"
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/6.2/sys/kern/kern_module.c 164286 2006-11-14 20:42:41Z cvs2svn $");
31
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/systm.h>
35 #include <sys/eventhandler.h>
36 #include <sys/malloc.h>
37 #include <sys/sysproto.h>
38 #include <sys/sysent.h>
39 #include <sys/proc.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/reboot.h>
43 #include <sys/sx.h>
44 #include <sys/module.h>
45 #include <sys/linker.h>
46
47 static MALLOC_DEFINE(M_MODULE, "module", "module data structures");
48
49 typedef TAILQ_HEAD(, module) modulelist_t;
50 struct module {
51 TAILQ_ENTRY(module) link; /* chain together all modules */
52 TAILQ_ENTRY(module) flink; /* all modules in a file */
53 struct linker_file *file; /* file which contains this module */
54 int refs; /* reference count */
55 int id; /* unique id number */
56 char *name; /* module name */
57 modeventhand_t handler; /* event handler */
58 void *arg; /* argument for handler */
59 modspecific_t data; /* module specific data */
60 };
61
62 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg)
63
64 static modulelist_t modules;
65 struct sx modules_sx;
66 static int nextid = 1;
67 static void module_shutdown(void *, int);
68
69 static int
70 modevent_nop(module_t mod, int what, void *arg)
71 {
72
73 switch(what) {
74 case MOD_LOAD:
75 return (0);
76 case MOD_UNLOAD:
77 return (EBUSY);
78 default:
79 return (EOPNOTSUPP);
80 }
81 }
82
83 static void
84 module_init(void *arg)
85 {
86
87 sx_init(&modules_sx, "module subsystem sx lock");
88 TAILQ_INIT(&modules);
89 EVENTHANDLER_REGISTER(shutdown_final, module_shutdown, NULL,
90 SHUTDOWN_PRI_DEFAULT);
91 }
92
93 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0)
94
95 static void
96 module_shutdown(void *arg1, int arg2)
97 {
98 module_t mod;
99
100 if (arg2 & RB_NOSYNC)
101 return;
102 MOD_SLOCK;
103 TAILQ_FOREACH(mod, &modules, link)
104 MOD_EVENT(mod, MOD_SHUTDOWN);
105 MOD_SUNLOCK;
106 }
107
108 void
109 module_register_init(const void *arg)
110 {
111 const moduledata_t *data = (const moduledata_t *)arg;
112 int error;
113 module_t mod;
114
115 MOD_SLOCK;
116 mod = module_lookupbyname(data->name);
117 if (mod == NULL)
118 panic("module_register_init: module named %s not found\n",
119 data->name);
120 MOD_SUNLOCK;
121 error = MOD_EVENT(mod, MOD_LOAD);
122 if (error) {
123 MOD_EVENT(mod, MOD_UNLOAD);
124 MOD_XLOCK;
125 module_release(mod);
126 MOD_XUNLOCK;
127 printf("module_register_init: MOD_LOAD (%s, %p, %p) error"
128 " %d\n", data->name, (void *)data->evhand, data->priv,
129 error);
130 }
131 }
132
133 int
134 module_register(const moduledata_t *data, linker_file_t container)
135 {
136 size_t namelen;
137 module_t newmod;
138
139 MOD_XLOCK;
140 newmod = module_lookupbyname(data->name);
141 if (newmod != NULL) {
142 MOD_XUNLOCK;
143 printf("module_register: module %s already exists!\n",
144 data->name);
145 return (EEXIST);
146 }
147 namelen = strlen(data->name) + 1;
148 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK);
149 if (newmod == NULL) {
150 MOD_XUNLOCK;
151 return (ENOMEM);
152 }
153 newmod->refs = 1;
154 newmod->id = nextid++;
155 newmod->name = (char *)(newmod + 1);
156 strcpy(newmod->name, data->name);
157 newmod->handler = data->evhand ? data->evhand : modevent_nop;
158 newmod->arg = data->priv;
159 bzero(&newmod->data, sizeof(newmod->data));
160 TAILQ_INSERT_TAIL(&modules, newmod, link);
161
162 if (container)
163 TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
164 newmod->file = container;
165 MOD_XUNLOCK;
166 return (0);
167 }
168
169 void
170 module_reference(module_t mod)
171 {
172
173 MOD_XLOCK_ASSERT;
174
175 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
176 mod->refs++;
177 }
178
179 void
180 module_release(module_t mod)
181 {
182
183 MOD_XLOCK_ASSERT;
184
185 if (mod->refs <= 0)
186 panic("module_release: bad reference count");
187
188 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
189
190 mod->refs--;
191 if (mod->refs == 0) {
192 TAILQ_REMOVE(&modules, mod, link);
193 if (mod->file)
194 TAILQ_REMOVE(&mod->file->modules, mod, flink);
195 MOD_XUNLOCK;
196 free(mod, M_MODULE);
197 MOD_XLOCK;
198 }
199 }
200
201 module_t
202 module_lookupbyname(const char *name)
203 {
204 module_t mod;
205 int err;
206
207 MOD_LOCK_ASSERT;
208
209 TAILQ_FOREACH(mod, &modules, link) {
210 err = strcmp(mod->name, name);
211 if (err == 0)
212 return (mod);
213 }
214 return (NULL);
215 }
216
217 module_t
218 module_lookupbyid(int modid)
219 {
220 module_t mod;
221
222 MOD_LOCK_ASSERT;
223
224 TAILQ_FOREACH(mod, &modules, link)
225 if (mod->id == modid)
226 return(mod);
227 return (NULL);
228 }
229
230 int
231 module_unload(module_t mod, int flags)
232 {
233 int error;
234
235 error = MOD_EVENT(mod, MOD_QUIESCE);
236 if (error == EOPNOTSUPP || error == EINVAL)
237 error = 0;
238 if (flags == LINKER_UNLOAD_NORMAL && error != 0)
239 return (error);
240 return (MOD_EVENT(mod, MOD_UNLOAD));
241 }
242
243 int
244 module_getid(module_t mod)
245 {
246
247 MOD_LOCK_ASSERT;
248 return (mod->id);
249 }
250
251 module_t
252 module_getfnext(module_t mod)
253 {
254
255 MOD_LOCK_ASSERT;
256 return (TAILQ_NEXT(mod, flink));
257 }
258
259 void
260 module_setspecific(module_t mod, modspecific_t *datap)
261 {
262
263 MOD_XLOCK_ASSERT;
264 mod->data = *datap;
265 }
266
267 /*
268 * Syscalls.
269 */
270 /*
271 * MPSAFE
272 */
273 int
274 modnext(struct thread *td, struct modnext_args *uap)
275 {
276 module_t mod;
277 int error = 0;
278
279 td->td_retval[0] = -1;
280
281 MOD_SLOCK;
282 if (uap->modid == 0) {
283 mod = TAILQ_FIRST(&modules);
284 if (mod)
285 td->td_retval[0] = mod->id;
286 else
287 error = ENOENT;
288 goto done2;
289 }
290 mod = module_lookupbyid(uap->modid);
291 if (mod == NULL) {
292 error = ENOENT;
293 goto done2;
294 }
295 if (TAILQ_NEXT(mod, link))
296 td->td_retval[0] = TAILQ_NEXT(mod, link)->id;
297 else
298 td->td_retval[0] = 0;
299 done2:
300 MOD_SUNLOCK;
301 return (error);
302 }
303
304 /*
305 * MPSAFE
306 */
307 int
308 modfnext(struct thread *td, struct modfnext_args *uap)
309 {
310 module_t mod;
311 int error;
312
313 td->td_retval[0] = -1;
314
315 MOD_SLOCK;
316 mod = module_lookupbyid(uap->modid);
317 if (mod == NULL) {
318 error = ENOENT;
319 } else {
320 error = 0;
321 if (TAILQ_NEXT(mod, flink))
322 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id;
323 else
324 td->td_retval[0] = 0;
325 }
326 MOD_SUNLOCK;
327 return (error);
328 }
329
330 struct module_stat_v1 {
331 int version; /* set to sizeof(struct module_stat) */
332 char name[MAXMODNAME];
333 int refs;
334 int id;
335 };
336
337 /*
338 * MPSAFE
339 */
340 int
341 modstat(struct thread *td, struct modstat_args *uap)
342 {
343 module_t mod;
344 modspecific_t data;
345 int error = 0;
346 int id, namelen, refs, version;
347 struct module_stat *stat;
348 char *name;
349
350 MOD_SLOCK;
351 mod = module_lookupbyid(uap->modid);
352 if (mod == NULL) {
353 MOD_SUNLOCK;
354 return (ENOENT);
355 }
356 id = mod->id;
357 refs = mod->refs;
358 name = mod->name;
359 data = mod->data;
360 MOD_SUNLOCK;
361 stat = uap->stat;
362
363 /*
364 * Check the version of the user's structure.
365 */
366 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
367 return (error);
368 if (version != sizeof(struct module_stat_v1)
369 && version != sizeof(struct module_stat))
370 return (EINVAL);
371 namelen = strlen(mod->name) + 1;
372 if (namelen > MAXMODNAME)
373 namelen = MAXMODNAME;
374 if ((error = copyout(name, &stat->name[0], namelen)) != 0)
375 return (error);
376
377 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0)
378 return (error);
379 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0)
380 return (error);
381
382 /*
383 * >v1 stat includes module data.
384 */
385 if (version == sizeof(struct module_stat))
386 if ((error = copyout(&data, &stat->data,
387 sizeof(data))) != 0)
388 return (error);
389 td->td_retval[0] = 0;
390 return (error);
391 }
392
393 /*
394 * MPSAFE
395 */
396 int
397 modfind(struct thread *td, struct modfind_args *uap)
398 {
399 int error = 0;
400 char name[MAXMODNAME];
401 module_t mod;
402
403 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0)
404 return (error);
405
406 MOD_SLOCK;
407 mod = module_lookupbyname(name);
408 if (mod == NULL)
409 error = ENOENT;
410 else
411 td->td_retval[0] = module_getid(mod);
412 MOD_SUNLOCK;
413 return (error);
414 }
415
416 #ifdef COMPAT_IA32
417 #include <sys/mount.h>
418 #include <compat/freebsd32/freebsd32_util.h>
419 #include <compat/freebsd32/freebsd32.h>
420 #include <compat/freebsd32/freebsd32_proto.h>
421
422 typedef union modspecific32 {
423 int intval;
424 u_int32_t uintval;
425 int longval;
426 u_int32_t ulongval;
427 } modspecific32_t;
428
429 struct module_stat32 {
430 int version;
431 char name[MAXMODNAME];
432 int refs;
433 int id;
434 modspecific32_t data;
435 };
436
437 /*
438 * MPSAFE
439 */
440 int
441 freebsd32_modstat(struct thread *td, struct freebsd32_modstat_args *uap)
442 {
443 module_t mod;
444 modspecific32_t data32;
445 int error = 0;
446 int id, namelen, refs, version;
447 struct module_stat32 *stat32;
448 char *name;
449
450 MOD_SLOCK;
451 mod = module_lookupbyid(uap->modid);
452 if (mod == NULL) {
453 MOD_SUNLOCK;
454 return (ENOENT);
455 }
456
457 id = mod->id;
458 refs = mod->refs;
459 name = mod->name;
460 CP(mod->data, data32, intval);
461 CP(mod->data, data32, uintval);
462 CP(mod->data, data32, longval);
463 CP(mod->data, data32, ulongval);
464 MOD_SUNLOCK;
465 stat32 = uap->stat;
466
467 if ((error = copyin(&stat32->version, &version, sizeof(version))) != 0)
468 return (error);
469 if (version != sizeof(struct module_stat_v1)
470 && version != sizeof(struct module_stat32))
471 return (EINVAL);
472 namelen = strlen(mod->name) + 1;
473 if (namelen > MAXMODNAME)
474 namelen = MAXMODNAME;
475 if ((error = copyout(name, &stat32->name[0], namelen)) != 0)
476 return (error);
477
478 if ((error = copyout(&refs, &stat32->refs, sizeof(int))) != 0)
479 return (error);
480 if ((error = copyout(&id, &stat32->id, sizeof(int))) != 0)
481 return (error);
482
483 /*
484 * >v1 stat includes module data.
485 */
486 if (version == sizeof(struct module_stat32))
487 if ((error = copyout(&data32, &stat32->data,
488 sizeof(data32))) != 0)
489 return (error);
490 td->td_retval[0] = 0;
491 return (error);
492 }
493 #endif
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