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