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