1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1997 Doug Rabson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/eventhandler.h>
34 #include <sys/malloc.h>
35 #include <sys/sysproto.h>
36 #include <sys/sysent.h>
37 #include <sys/proc.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/reboot.h>
41 #include <sys/sx.h>
42 #include <sys/module.h>
43 #include <sys/linker.h>
44
45 static MALLOC_DEFINE(M_MODULE, "module", "module data structures");
46
47 struct module {
48 TAILQ_ENTRY(module) link; /* chain together all modules */
49 TAILQ_ENTRY(module) flink; /* all modules in a file */
50 struct linker_file *file; /* file which contains this module */
51 int refs; /* reference count */
52 int id; /* unique id number */
53 char *name; /* module name */
54 modeventhand_t handler; /* event handler */
55 void *arg; /* argument for handler */
56 modspecific_t data; /* module specific data */
57 };
58
59 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg)
60
61 static TAILQ_HEAD(modulelist, module) modules;
62 struct sx modules_sx;
63 static int nextid = 1;
64 static void module_shutdown(void *, int);
65
66 static int
modevent_nop(module_t mod,int what,void * arg)67 modevent_nop(module_t mod, int what, void *arg)
68 {
69
70 switch(what) {
71 case MOD_LOAD:
72 return (0);
73 case MOD_UNLOAD:
74 return (EBUSY);
75 default:
76 return (EOPNOTSUPP);
77 }
78 }
79
80 static void
module_init(void * arg)81 module_init(void *arg)
82 {
83
84 sx_init(&modules_sx, "module subsystem sx lock");
85 TAILQ_INIT(&modules);
86 EVENTHANDLER_REGISTER(shutdown_final, module_shutdown, NULL,
87 SHUTDOWN_PRI_DEFAULT);
88 }
89
90 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, NULL);
91
92 static void
module_shutdown(void * arg1,int arg2)93 module_shutdown(void *arg1, int arg2)
94 {
95 module_t mod;
96
97 if (arg2 & RB_NOSYNC)
98 return;
99 mtx_lock(&Giant);
100 MOD_SLOCK;
101 TAILQ_FOREACH_REVERSE(mod, &modules, modulelist, link)
102 MOD_EVENT(mod, MOD_SHUTDOWN);
103 MOD_SUNLOCK;
104 mtx_unlock(&Giant);
105 }
106
107 void
module_register_init(const void * arg)108 module_register_init(const void *arg)
109 {
110 const moduledata_t *data = (const moduledata_t *)arg;
111 int error;
112 module_t mod;
113
114 mtx_lock(&Giant);
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 } else {
131 MOD_XLOCK;
132 if (mod->file) {
133 /*
134 * Once a module is successfully loaded, move
135 * it to the head of the module list for this
136 * linker file. This resorts the list so that
137 * when the kernel linker iterates over the
138 * modules to unload them, it will unload them
139 * in the reverse order they were loaded.
140 */
141 TAILQ_REMOVE(&mod->file->modules, mod, flink);
142 TAILQ_INSERT_HEAD(&mod->file->modules, mod, flink);
143 }
144 MOD_XUNLOCK;
145 }
146 mtx_unlock(&Giant);
147 }
148
149 int
module_register(const moduledata_t * data,linker_file_t container)150 module_register(const moduledata_t *data, linker_file_t container)
151 {
152 size_t namelen;
153 module_t newmod;
154
155 MOD_XLOCK;
156 newmod = module_lookupbyname(data->name);
157 if (newmod != NULL) {
158 MOD_XUNLOCK;
159 printf("%s: cannot register %s from %s; already loaded from %s\n",
160 __func__, data->name, container->filename, newmod->file->filename);
161 return (EEXIST);
162 }
163 namelen = strlen(data->name) + 1;
164 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK);
165 newmod->refs = 1;
166 newmod->id = nextid++;
167 newmod->name = (char *)(newmod + 1);
168 strcpy(newmod->name, data->name);
169 newmod->handler = data->evhand ? data->evhand : modevent_nop;
170 newmod->arg = data->priv;
171 bzero(&newmod->data, sizeof(newmod->data));
172 TAILQ_INSERT_TAIL(&modules, newmod, link);
173
174 if (container)
175 TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
176 newmod->file = container;
177 MOD_XUNLOCK;
178 return (0);
179 }
180
181 void
module_reference(module_t mod)182 module_reference(module_t mod)
183 {
184
185 MOD_XLOCK_ASSERT;
186
187 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
188 mod->refs++;
189 }
190
191 void
module_release(module_t mod)192 module_release(module_t mod)
193 {
194
195 MOD_XLOCK_ASSERT;
196
197 if (mod->refs <= 0)
198 panic("module_release: bad reference count");
199
200 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
201
202 mod->refs--;
203 if (mod->refs == 0) {
204 TAILQ_REMOVE(&modules, mod, link);
205 if (mod->file)
206 TAILQ_REMOVE(&mod->file->modules, mod, flink);
207 free(mod, M_MODULE);
208 }
209 }
210
211 module_t
module_lookupbyname(const char * name)212 module_lookupbyname(const char *name)
213 {
214 module_t mod;
215 int err;
216
217 MOD_LOCK_ASSERT;
218
219 TAILQ_FOREACH(mod, &modules, link) {
220 err = strcmp(mod->name, name);
221 if (err == 0)
222 return (mod);
223 }
224 return (NULL);
225 }
226
227 module_t
module_lookupbyid(int modid)228 module_lookupbyid(int modid)
229 {
230 module_t mod;
231
232 MOD_LOCK_ASSERT;
233
234 TAILQ_FOREACH(mod, &modules, link)
235 if (mod->id == modid)
236 return(mod);
237 return (NULL);
238 }
239
240 int
module_quiesce(module_t mod)241 module_quiesce(module_t mod)
242 {
243 int error;
244
245 mtx_lock(&Giant);
246 error = MOD_EVENT(mod, MOD_QUIESCE);
247 mtx_unlock(&Giant);
248 if (error == EOPNOTSUPP || error == EINVAL)
249 error = 0;
250 return (error);
251 }
252
253 int
module_unload(module_t mod)254 module_unload(module_t mod)
255 {
256 int error;
257
258 mtx_lock(&Giant);
259 error = MOD_EVENT(mod, MOD_UNLOAD);
260 mtx_unlock(&Giant);
261 return (error);
262 }
263
264 int
module_getid(module_t mod)265 module_getid(module_t mod)
266 {
267
268 MOD_LOCK_ASSERT;
269 return (mod->id);
270 }
271
272 module_t
module_getfnext(module_t mod)273 module_getfnext(module_t mod)
274 {
275
276 MOD_LOCK_ASSERT;
277 return (TAILQ_NEXT(mod, flink));
278 }
279
280 const char *
module_getname(module_t mod)281 module_getname(module_t mod)
282 {
283
284 MOD_LOCK_ASSERT;
285 return (mod->name);
286 }
287
288 void
module_setspecific(module_t mod,modspecific_t * datap)289 module_setspecific(module_t mod, modspecific_t *datap)
290 {
291
292 MOD_XLOCK_ASSERT;
293 mod->data = *datap;
294 }
295
296 linker_file_t
module_file(module_t mod)297 module_file(module_t mod)
298 {
299
300 return (mod->file);
301 }
302
303 /*
304 * Syscalls.
305 */
306 int
sys_modnext(struct thread * td,struct modnext_args * uap)307 sys_modnext(struct thread *td, struct modnext_args *uap)
308 {
309 module_t mod;
310 int error = 0;
311
312 td->td_retval[0] = -1;
313
314 MOD_SLOCK;
315 if (uap->modid == 0) {
316 mod = TAILQ_FIRST(&modules);
317 if (mod)
318 td->td_retval[0] = mod->id;
319 else
320 error = ENOENT;
321 goto done2;
322 }
323 mod = module_lookupbyid(uap->modid);
324 if (mod == NULL) {
325 error = ENOENT;
326 goto done2;
327 }
328 if (TAILQ_NEXT(mod, link))
329 td->td_retval[0] = TAILQ_NEXT(mod, link)->id;
330 else
331 td->td_retval[0] = 0;
332 done2:
333 MOD_SUNLOCK;
334 return (error);
335 }
336
337 int
sys_modfnext(struct thread * td,struct modfnext_args * uap)338 sys_modfnext(struct thread *td, struct modfnext_args *uap)
339 {
340 module_t mod;
341 int error;
342
343 td->td_retval[0] = -1;
344
345 MOD_SLOCK;
346 mod = module_lookupbyid(uap->modid);
347 if (mod == NULL) {
348 error = ENOENT;
349 } else {
350 error = 0;
351 if (TAILQ_NEXT(mod, flink))
352 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id;
353 else
354 td->td_retval[0] = 0;
355 }
356 MOD_SUNLOCK;
357 return (error);
358 }
359
360 struct module_stat_v1 {
361 int version; /* set to sizeof(struct module_stat) */
362 char name[MAXMODNAMEV1V2];
363 int refs;
364 int id;
365 };
366
367 struct module_stat_v2 {
368 int version; /* set to sizeof(struct module_stat) */
369 char name[MAXMODNAMEV1V2];
370 int refs;
371 int id;
372 modspecific_t data;
373 };
374
375 int
sys_modstat(struct thread * td,struct modstat_args * uap)376 sys_modstat(struct thread *td, struct modstat_args *uap)
377 {
378 module_t mod;
379 modspecific_t data;
380 int error = 0;
381 int id, namelen, refs, version;
382 struct module_stat *stat;
383 struct module_stat_v2 *stat_v2;
384 char *name;
385 bool is_v1v2;
386
387 MOD_SLOCK;
388 mod = module_lookupbyid(uap->modid);
389 if (mod == NULL) {
390 MOD_SUNLOCK;
391 return (ENOENT);
392 }
393 id = mod->id;
394 refs = mod->refs;
395 name = mod->name;
396 data = mod->data;
397 MOD_SUNLOCK;
398 stat = uap->stat;
399
400 /*
401 * Check the version of the user's structure.
402 */
403 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
404 return (error);
405 is_v1v2 = (version == sizeof(struct module_stat_v1) ||
406 version == sizeof(struct module_stat_v2));
407 if (!is_v1v2 && version != sizeof(struct module_stat))
408 return (EINVAL);
409 namelen = strlen(mod->name) + 1;
410 if (is_v1v2 && namelen > MAXMODNAMEV1V2)
411 namelen = MAXMODNAMEV1V2;
412 else if (namelen > MAXMODNAMEV3)
413 namelen = MAXMODNAMEV3;
414 if ((error = copyout(name, &stat->name[0], namelen)) != 0)
415 return (error);
416
417 /* Extending MAXMODNAME gives an offset change for v3. */
418 if (is_v1v2) {
419 stat_v2 = (struct module_stat_v2 *)stat;
420 if ((error = copyout(&refs, &stat_v2->refs, sizeof(int))) != 0)
421 return (error);
422 if ((error = copyout(&id, &stat_v2->id, sizeof(int))) != 0)
423 return (error);
424 } else {
425 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0)
426 return (error);
427 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0)
428 return (error);
429 }
430
431 /*
432 * >v1 stat includes module data.
433 */
434 if (version == sizeof(struct module_stat_v2)) {
435 if ((error = copyout(&data, &stat_v2->data,
436 sizeof(data))) != 0)
437 return (error);
438 } else if (version == sizeof(struct module_stat)) {
439 if ((error = copyout(&data, &stat->data,
440 sizeof(data))) != 0)
441 return (error);
442 }
443 td->td_retval[0] = 0;
444 return (error);
445 }
446
447 int
sys_modfind(struct thread * td,struct modfind_args * uap)448 sys_modfind(struct thread *td, struct modfind_args *uap)
449 {
450 int error = 0;
451 char name[MAXMODNAMEV3];
452 module_t mod;
453
454 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0)
455 return (error);
456
457 MOD_SLOCK;
458 mod = module_lookupbyname(name);
459 if (mod == NULL)
460 error = ENOENT;
461 else
462 td->td_retval[0] = module_getid(mod);
463 MOD_SUNLOCK;
464 return (error);
465 }
466
467 MODULE_VERSION(kernel, __FreeBSD_version);
468
469 #ifdef COMPAT_FREEBSD32
470 #include <sys/mount.h>
471 #include <sys/socket.h>
472 #include <compat/freebsd32/freebsd32_util.h>
473 #include <compat/freebsd32/freebsd32.h>
474 #include <compat/freebsd32/freebsd32_proto.h>
475
476 typedef union modspecific32 {
477 int intval;
478 uint32_t uintval;
479 int longval;
480 uint32_t ulongval;
481 } modspecific32_t;
482
483 struct module_stat32_v2 {
484 int version;
485 char name[MAXMODNAMEV1V2];
486 int refs;
487 int id;
488 modspecific32_t data;
489 };
490
491 struct module_stat32 {
492 int version;
493 char name[MAXMODNAME];
494 int refs;
495 int id;
496 modspecific32_t data;
497 };
498
499 int
freebsd32_modstat(struct thread * td,struct freebsd32_modstat_args * uap)500 freebsd32_modstat(struct thread *td, struct freebsd32_modstat_args *uap)
501 {
502 module_t mod;
503 modspecific32_t data32;
504 int error = 0;
505 int id, namelen, refs, version;
506 struct module_stat32 *stat32;
507 struct module_stat32_v2 *stat32_v2;
508 char *name;
509 bool is_v1v2;
510
511 MOD_SLOCK;
512 mod = module_lookupbyid(uap->modid);
513 if (mod == NULL) {
514 MOD_SUNLOCK;
515 return (ENOENT);
516 }
517
518 id = mod->id;
519 refs = mod->refs;
520 name = mod->name;
521 _Static_assert(sizeof(data32) == sizeof(data32.uintval),
522 "bad modspecific32_t size");
523 CP(mod->data, data32, uintval);
524 MOD_SUNLOCK;
525 stat32 = uap->stat;
526
527 if ((error = copyin(&stat32->version, &version, sizeof(version))) != 0)
528 return (error);
529 is_v1v2 = (version == sizeof(struct module_stat_v1) ||
530 version == sizeof(struct module_stat32_v2));
531 if (!is_v1v2 && version != sizeof(struct module_stat32))
532 return (EINVAL);
533 namelen = strlen(mod->name) + 1;
534 if (is_v1v2 && namelen > MAXMODNAMEV1V2)
535 namelen = MAXMODNAMEV1V2;
536 else if (namelen > MAXMODNAMEV3)
537 namelen = MAXMODNAMEV3;
538 if ((error = copyout(name, &stat32->name[0], namelen)) != 0)
539 return (error);
540
541 /* Extending MAXMODNAME gives an offset change for v3. */
542 if (is_v1v2) {
543 stat32_v2 = (struct module_stat32_v2 *)stat32;
544 if ((error = copyout(&refs, &stat32_v2->refs, sizeof(int))) != 0)
545 return (error);
546 if ((error = copyout(&id, &stat32_v2->id, sizeof(int))) != 0)
547 return (error);
548 } else {
549 if ((error = copyout(&refs, &stat32->refs, sizeof(int))) != 0)
550 return (error);
551 if ((error = copyout(&id, &stat32->id, sizeof(int))) != 0)
552 return (error);
553 }
554
555 /*
556 * >v1 stat includes module data.
557 */
558 if (version == sizeof(struct module_stat32_v2)) {
559 if ((error = copyout(&data32, &stat32_v2->data,
560 sizeof(data32))) != 0)
561 return (error);
562 } else if (version == sizeof(struct module_stat32)) {
563 if ((error = copyout(&data32, &stat32->data,
564 sizeof(data32))) != 0)
565 return (error);
566 }
567 td->td_retval[0] = 0;
568 return (error);
569 }
570 #endif
571