1 /*-
2 * Copyright (c) 1997-2000 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 <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.1/sys/kern/kern_linker.c 264370 2014-04-12 14:18:25Z kib $");
29
30 #include "opt_ddb.h"
31 #include "opt_kld.h"
32 #include "opt_hwpmc_hooks.h"
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/sysproto.h>
39 #include <sys/sysent.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/sx.h>
45 #include <sys/module.h>
46 #include <sys/mount.h>
47 #include <sys/linker.h>
48 #include <sys/eventhandler.h>
49 #include <sys/fcntl.h>
50 #include <sys/jail.h>
51 #include <sys/libkern.h>
52 #include <sys/namei.h>
53 #include <sys/vnode.h>
54 #include <sys/syscallsubr.h>
55 #include <sys/sysctl.h>
56
57 #include <net/vnet.h>
58
59 #include <security/mac/mac_framework.h>
60
61 #include "linker_if.h"
62
63 #ifdef HWPMC_HOOKS
64 #include <sys/pmckern.h>
65 #endif
66
67 #ifdef KLD_DEBUG
68 int kld_debug = 0;
69 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW | CTLFLAG_TUN,
70 &kld_debug, 0, "Set various levels of KLD debug");
71 TUNABLE_INT("debug.kld_debug", &kld_debug);
72 #endif
73
74 /*
75 * static char *linker_search_path(const char *name, struct mod_depend
76 * *verinfo);
77 */
78 static const char *linker_basename(const char *path);
79
80 /*
81 * Find a currently loaded file given its filename.
82 */
83 static linker_file_t linker_find_file_by_name(const char* _filename);
84
85 /*
86 * Find a currently loaded file given its file id.
87 */
88 static linker_file_t linker_find_file_by_id(int _fileid);
89
90 /* Metadata from the static kernel */
91 SET_DECLARE(modmetadata_set, struct mod_metadata);
92
93 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
94
95 linker_file_t linker_kernel_file;
96
97 static struct sx kld_sx; /* kernel linker lock */
98
99 /*
100 * Load counter used by clients to determine if a linker file has been
101 * re-loaded. This counter is incremented for each file load.
102 */
103 static int loadcnt;
104
105 static linker_class_list_t classes;
106 static linker_file_list_t linker_files;
107 static int next_file_id = 1;
108 static int linker_no_more_classes = 0;
109
110 #define LINKER_GET_NEXT_FILE_ID(a) do { \
111 linker_file_t lftmp; \
112 \
113 if (!cold) \
114 sx_assert(&kld_sx, SA_XLOCKED); \
115 retry: \
116 TAILQ_FOREACH(lftmp, &linker_files, link) { \
117 if (next_file_id == lftmp->id) { \
118 next_file_id++; \
119 goto retry; \
120 } \
121 } \
122 (a) = next_file_id; \
123 } while(0)
124
125
126 /* XXX wrong name; we're looking at version provision tags here, not modules */
127 typedef TAILQ_HEAD(, modlist) modlisthead_t;
128 struct modlist {
129 TAILQ_ENTRY(modlist) link; /* chain together all modules */
130 linker_file_t container;
131 const char *name;
132 int version;
133 };
134 typedef struct modlist *modlist_t;
135 static modlisthead_t found_modules;
136
137 static int linker_file_add_dependency(linker_file_t file,
138 linker_file_t dep);
139 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
140 const char* name, int deps);
141 static int linker_load_module(const char *kldname,
142 const char *modname, struct linker_file *parent,
143 struct mod_depend *verinfo, struct linker_file **lfpp);
144 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
145
146 static void
147 linker_init(void *arg)
148 {
149
150 sx_init(&kld_sx, "kernel linker");
151 TAILQ_INIT(&classes);
152 TAILQ_INIT(&linker_files);
153 }
154
155 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
156
157 static void
158 linker_stop_class_add(void *arg)
159 {
160
161 linker_no_more_classes = 1;
162 }
163
164 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
165
166 int
167 linker_add_class(linker_class_t lc)
168 {
169
170 /*
171 * We disallow any class registration past SI_ORDER_ANY
172 * of SI_SUB_KLD. We bump the reference count to keep the
173 * ops from being freed.
174 */
175 if (linker_no_more_classes == 1)
176 return (EPERM);
177 kobj_class_compile((kobj_class_t) lc);
178 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */
179 TAILQ_INSERT_TAIL(&classes, lc, link);
180 return (0);
181 }
182
183 static void
184 linker_file_sysinit(linker_file_t lf)
185 {
186 struct sysinit **start, **stop, **sipp, **xipp, *save;
187
188 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
189 lf->filename));
190
191 sx_assert(&kld_sx, SA_XLOCKED);
192
193 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
194 return;
195 /*
196 * Perform a bubble sort of the system initialization objects by
197 * their subsystem (primary key) and order (secondary key).
198 *
199 * Since some things care about execution order, this is the operation
200 * which ensures continued function.
201 */
202 for (sipp = start; sipp < stop; sipp++) {
203 for (xipp = sipp + 1; xipp < stop; xipp++) {
204 if ((*sipp)->subsystem < (*xipp)->subsystem ||
205 ((*sipp)->subsystem == (*xipp)->subsystem &&
206 (*sipp)->order <= (*xipp)->order))
207 continue; /* skip */
208 save = *sipp;
209 *sipp = *xipp;
210 *xipp = save;
211 }
212 }
213
214 /*
215 * Traverse the (now) ordered list of system initialization tasks.
216 * Perform each task, and continue on to the next task.
217 */
218 sx_xunlock(&kld_sx);
219 mtx_lock(&Giant);
220 for (sipp = start; sipp < stop; sipp++) {
221 if ((*sipp)->subsystem == SI_SUB_DUMMY)
222 continue; /* skip dummy task(s) */
223
224 /* Call function */
225 (*((*sipp)->func)) ((*sipp)->udata);
226 }
227 mtx_unlock(&Giant);
228 sx_xlock(&kld_sx);
229 }
230
231 static void
232 linker_file_sysuninit(linker_file_t lf)
233 {
234 struct sysinit **start, **stop, **sipp, **xipp, *save;
235
236 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
237 lf->filename));
238
239 sx_assert(&kld_sx, SA_XLOCKED);
240
241 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
242 NULL) != 0)
243 return;
244
245 /*
246 * Perform a reverse bubble sort of the system initialization objects
247 * by their subsystem (primary key) and order (secondary key).
248 *
249 * Since some things care about execution order, this is the operation
250 * which ensures continued function.
251 */
252 for (sipp = start; sipp < stop; sipp++) {
253 for (xipp = sipp + 1; xipp < stop; xipp++) {
254 if ((*sipp)->subsystem > (*xipp)->subsystem ||
255 ((*sipp)->subsystem == (*xipp)->subsystem &&
256 (*sipp)->order >= (*xipp)->order))
257 continue; /* skip */
258 save = *sipp;
259 *sipp = *xipp;
260 *xipp = save;
261 }
262 }
263
264 /*
265 * Traverse the (now) ordered list of system initialization tasks.
266 * Perform each task, and continue on to the next task.
267 */
268 sx_xunlock(&kld_sx);
269 mtx_lock(&Giant);
270 for (sipp = start; sipp < stop; sipp++) {
271 if ((*sipp)->subsystem == SI_SUB_DUMMY)
272 continue; /* skip dummy task(s) */
273
274 /* Call function */
275 (*((*sipp)->func)) ((*sipp)->udata);
276 }
277 mtx_unlock(&Giant);
278 sx_xlock(&kld_sx);
279 }
280
281 static void
282 linker_file_register_sysctls(linker_file_t lf)
283 {
284 struct sysctl_oid **start, **stop, **oidp;
285
286 KLD_DPF(FILE,
287 ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
288 lf->filename));
289
290 sx_assert(&kld_sx, SA_XLOCKED);
291
292 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
293 return;
294
295 sx_xunlock(&kld_sx);
296 sysctl_lock();
297 for (oidp = start; oidp < stop; oidp++)
298 sysctl_register_oid(*oidp);
299 sysctl_unlock();
300 sx_xlock(&kld_sx);
301 }
302
303 static void
304 linker_file_unregister_sysctls(linker_file_t lf)
305 {
306 struct sysctl_oid **start, **stop, **oidp;
307
308 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
309 " for %s\n", lf->filename));
310
311 sx_assert(&kld_sx, SA_XLOCKED);
312
313 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
314 return;
315
316 sx_xunlock(&kld_sx);
317 sysctl_lock();
318 for (oidp = start; oidp < stop; oidp++)
319 sysctl_unregister_oid(*oidp);
320 sysctl_unlock();
321 sx_xlock(&kld_sx);
322 }
323
324 static int
325 linker_file_register_modules(linker_file_t lf)
326 {
327 struct mod_metadata **start, **stop, **mdp;
328 const moduledata_t *moddata;
329 int first_error, error;
330
331 KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
332 " in %s\n", lf->filename));
333
334 sx_assert(&kld_sx, SA_XLOCKED);
335
336 if (linker_file_lookup_set(lf, "modmetadata_set", &start,
337 &stop, NULL) != 0) {
338 /*
339 * This fallback should be unnecessary, but if we get booted
340 * from boot2 instead of loader and we are missing our
341 * metadata then we have to try the best we can.
342 */
343 if (lf == linker_kernel_file) {
344 start = SET_BEGIN(modmetadata_set);
345 stop = SET_LIMIT(modmetadata_set);
346 } else
347 return (0);
348 }
349 first_error = 0;
350 for (mdp = start; mdp < stop; mdp++) {
351 if ((*mdp)->md_type != MDT_MODULE)
352 continue;
353 moddata = (*mdp)->md_data;
354 KLD_DPF(FILE, ("Registering module %s in %s\n",
355 moddata->name, lf->filename));
356 error = module_register(moddata, lf);
357 if (error) {
358 printf("Module %s failed to register: %d\n",
359 moddata->name, error);
360 if (first_error == 0)
361 first_error = error;
362 }
363 }
364 return (first_error);
365 }
366
367 static void
368 linker_init_kernel_modules(void)
369 {
370
371 sx_xlock(&kld_sx);
372 linker_file_register_modules(linker_kernel_file);
373 sx_xunlock(&kld_sx);
374 }
375
376 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
377 0);
378
379 static int
380 linker_load_file(const char *filename, linker_file_t *result)
381 {
382 linker_class_t lc;
383 linker_file_t lf;
384 int foundfile, error, modules;
385
386 /* Refuse to load modules if securelevel raised */
387 if (prison0.pr_securelevel > 0)
388 return (EPERM);
389
390 sx_assert(&kld_sx, SA_XLOCKED);
391 lf = linker_find_file_by_name(filename);
392 if (lf) {
393 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
394 " incrementing refs\n", filename));
395 *result = lf;
396 lf->refs++;
397 return (0);
398 }
399 foundfile = 0;
400 error = 0;
401
402 /*
403 * We do not need to protect (lock) classes here because there is
404 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
405 * and there is no class deregistration mechanism at this time.
406 */
407 TAILQ_FOREACH(lc, &classes, link) {
408 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
409 filename));
410 error = LINKER_LOAD_FILE(lc, filename, &lf);
411 /*
412 * If we got something other than ENOENT, then it exists but
413 * we cannot load it for some other reason.
414 */
415 if (error != ENOENT)
416 foundfile = 1;
417 if (lf) {
418 error = linker_file_register_modules(lf);
419 if (error == EEXIST) {
420 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
421 return (error);
422 }
423 modules = !TAILQ_EMPTY(&lf->modules);
424 linker_file_register_sysctls(lf);
425 linker_file_sysinit(lf);
426 lf->flags |= LINKER_FILE_LINKED;
427
428 /*
429 * If all of the modules in this file failed
430 * to load, unload the file and return an
431 * error of ENOEXEC.
432 */
433 if (modules && TAILQ_EMPTY(&lf->modules)) {
434 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
435 return (ENOEXEC);
436 }
437 EVENTHANDLER_INVOKE(kld_load, lf);
438 *result = lf;
439 return (0);
440 }
441 }
442 /*
443 * Less than ideal, but tells the user whether it failed to load or
444 * the module was not found.
445 */
446 if (foundfile) {
447
448 /*
449 * If the file type has not been recognized by the last try
450 * printout a message before to fail.
451 */
452 if (error == ENOSYS)
453 printf("linker_load_file: Unsupported file type\n");
454
455 /*
456 * Format not recognized or otherwise unloadable.
457 * When loading a module that is statically built into
458 * the kernel EEXIST percolates back up as the return
459 * value. Preserve this so that apps like sysinstall
460 * can recognize this special case and not post bogus
461 * dialog boxes.
462 */
463 if (error != EEXIST)
464 error = ENOEXEC;
465 } else
466 error = ENOENT; /* Nothing found */
467 return (error);
468 }
469
470 int
471 linker_reference_module(const char *modname, struct mod_depend *verinfo,
472 linker_file_t *result)
473 {
474 modlist_t mod;
475 int error;
476
477 sx_xlock(&kld_sx);
478 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
479 *result = mod->container;
480 (*result)->refs++;
481 sx_xunlock(&kld_sx);
482 return (0);
483 }
484
485 error = linker_load_module(NULL, modname, NULL, verinfo, result);
486 sx_xunlock(&kld_sx);
487 return (error);
488 }
489
490 int
491 linker_release_module(const char *modname, struct mod_depend *verinfo,
492 linker_file_t lf)
493 {
494 modlist_t mod;
495 int error;
496
497 sx_xlock(&kld_sx);
498 if (lf == NULL) {
499 KASSERT(modname != NULL,
500 ("linker_release_module: no file or name"));
501 mod = modlist_lookup2(modname, verinfo);
502 if (mod == NULL) {
503 sx_xunlock(&kld_sx);
504 return (ESRCH);
505 }
506 lf = mod->container;
507 } else
508 KASSERT(modname == NULL && verinfo == NULL,
509 ("linker_release_module: both file and name"));
510 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
511 sx_xunlock(&kld_sx);
512 return (error);
513 }
514
515 static linker_file_t
516 linker_find_file_by_name(const char *filename)
517 {
518 linker_file_t lf;
519 char *koname;
520
521 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
522 sprintf(koname, "%s.ko", filename);
523
524 sx_assert(&kld_sx, SA_XLOCKED);
525 TAILQ_FOREACH(lf, &linker_files, link) {
526 if (strcmp(lf->filename, koname) == 0)
527 break;
528 if (strcmp(lf->filename, filename) == 0)
529 break;
530 }
531 free(koname, M_LINKER);
532 return (lf);
533 }
534
535 static linker_file_t
536 linker_find_file_by_id(int fileid)
537 {
538 linker_file_t lf;
539
540 sx_assert(&kld_sx, SA_XLOCKED);
541 TAILQ_FOREACH(lf, &linker_files, link)
542 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
543 break;
544 return (lf);
545 }
546
547 int
548 linker_file_foreach(linker_predicate_t *predicate, void *context)
549 {
550 linker_file_t lf;
551 int retval = 0;
552
553 sx_xlock(&kld_sx);
554 TAILQ_FOREACH(lf, &linker_files, link) {
555 retval = predicate(lf, context);
556 if (retval != 0)
557 break;
558 }
559 sx_xunlock(&kld_sx);
560 return (retval);
561 }
562
563 linker_file_t
564 linker_make_file(const char *pathname, linker_class_t lc)
565 {
566 linker_file_t lf;
567 const char *filename;
568
569 if (!cold)
570 sx_assert(&kld_sx, SA_XLOCKED);
571 filename = linker_basename(pathname);
572
573 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
574 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
575 if (lf == NULL)
576 return (NULL);
577 lf->refs = 1;
578 lf->userrefs = 0;
579 lf->flags = 0;
580 lf->filename = strdup(filename, M_LINKER);
581 lf->pathname = strdup(pathname, M_LINKER);
582 LINKER_GET_NEXT_FILE_ID(lf->id);
583 lf->ndeps = 0;
584 lf->deps = NULL;
585 lf->loadcnt = ++loadcnt;
586 STAILQ_INIT(&lf->common);
587 TAILQ_INIT(&lf->modules);
588 TAILQ_INSERT_TAIL(&linker_files, lf, link);
589 return (lf);
590 }
591
592 int
593 linker_file_unload(linker_file_t file, int flags)
594 {
595 module_t mod, next;
596 modlist_t ml, nextml;
597 struct common_symbol *cp;
598 int error, i;
599
600 /* Refuse to unload modules if securelevel raised. */
601 if (prison0.pr_securelevel > 0)
602 return (EPERM);
603
604 sx_assert(&kld_sx, SA_XLOCKED);
605 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
606
607 /* Easy case of just dropping a reference. */
608 if (file->refs > 1) {
609 file->refs--;
610 return (0);
611 }
612
613 /* Give eventhandlers a chance to prevent the unload. */
614 error = 0;
615 EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
616 if (error != 0)
617 return (EBUSY);
618
619 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
620 " informing modules\n"));
621
622 /*
623 * Quiesce all the modules to give them a chance to veto the unload.
624 */
625 MOD_SLOCK;
626 for (mod = TAILQ_FIRST(&file->modules); mod;
627 mod = module_getfnext(mod)) {
628
629 error = module_quiesce(mod);
630 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
631 KLD_DPF(FILE, ("linker_file_unload: module %s"
632 " vetoed unload\n", module_getname(mod)));
633 /*
634 * XXX: Do we need to tell all the quiesced modules
635 * that they can resume work now via a new module
636 * event?
637 */
638 MOD_SUNLOCK;
639 return (error);
640 }
641 }
642 MOD_SUNLOCK;
643
644 /*
645 * Inform any modules associated with this file that they are
646 * being unloaded.
647 */
648 MOD_XLOCK;
649 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
650 next = module_getfnext(mod);
651 MOD_XUNLOCK;
652
653 /*
654 * Give the module a chance to veto the unload.
655 */
656 if ((error = module_unload(mod)) != 0) {
657 #ifdef KLD_DEBUG
658 MOD_SLOCK;
659 KLD_DPF(FILE, ("linker_file_unload: module %s"
660 " failed unload\n", module_getname(mod)));
661 MOD_SUNLOCK;
662 #endif
663 return (error);
664 }
665 MOD_XLOCK;
666 module_release(mod);
667 }
668 MOD_XUNLOCK;
669
670 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
671 if (ml->container == file) {
672 TAILQ_REMOVE(&found_modules, ml, link);
673 free(ml, M_LINKER);
674 }
675 }
676
677 /*
678 * Don't try to run SYSUNINITs if we are unloaded due to a
679 * link error.
680 */
681 if (file->flags & LINKER_FILE_LINKED) {
682 file->flags &= ~LINKER_FILE_LINKED;
683 linker_file_sysuninit(file);
684 linker_file_unregister_sysctls(file);
685 }
686 TAILQ_REMOVE(&linker_files, file, link);
687
688 if (file->deps) {
689 for (i = 0; i < file->ndeps; i++)
690 linker_file_unload(file->deps[i], flags);
691 free(file->deps, M_LINKER);
692 file->deps = NULL;
693 }
694 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
695 STAILQ_REMOVE_HEAD(&file->common, link);
696 free(cp, M_LINKER);
697 }
698
699 LINKER_UNLOAD(file);
700
701 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
702 file->size);
703
704 if (file->filename) {
705 free(file->filename, M_LINKER);
706 file->filename = NULL;
707 }
708 if (file->pathname) {
709 free(file->pathname, M_LINKER);
710 file->pathname = NULL;
711 }
712 kobj_delete((kobj_t) file, M_LINKER);
713 return (0);
714 }
715
716 int
717 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
718 {
719 return (LINKER_CTF_GET(file, lc));
720 }
721
722 static int
723 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
724 {
725 linker_file_t *newdeps;
726
727 sx_assert(&kld_sx, SA_XLOCKED);
728 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
729 M_LINKER, M_WAITOK | M_ZERO);
730 file->deps[file->ndeps] = dep;
731 file->ndeps++;
732 KLD_DPF(FILE, ("linker_file_add_dependency:"
733 " adding %s as dependency for %s\n",
734 dep->filename, file->filename));
735 return (0);
736 }
737
738 /*
739 * Locate a linker set and its contents. This is a helper function to avoid
740 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
741 * This function is used in this file so we can avoid having lots of (void **)
742 * casts.
743 */
744 int
745 linker_file_lookup_set(linker_file_t file, const char *name,
746 void *firstp, void *lastp, int *countp)
747 {
748
749 sx_assert(&kld_sx, SA_LOCKED);
750 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
751 }
752
753 /*
754 * List all functions in a file.
755 */
756 int
757 linker_file_function_listall(linker_file_t lf,
758 linker_function_nameval_callback_t callback_func, void *arg)
759 {
760 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
761 }
762
763 caddr_t
764 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
765 {
766 caddr_t sym;
767 int locked;
768
769 locked = sx_xlocked(&kld_sx);
770 if (!locked)
771 sx_xlock(&kld_sx);
772 sym = linker_file_lookup_symbol_internal(file, name, deps);
773 if (!locked)
774 sx_xunlock(&kld_sx);
775 return (sym);
776 }
777
778 static caddr_t
779 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
780 int deps)
781 {
782 c_linker_sym_t sym;
783 linker_symval_t symval;
784 caddr_t address;
785 size_t common_size = 0;
786 int i;
787
788 sx_assert(&kld_sx, SA_XLOCKED);
789 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
790 file, name, deps));
791
792 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
793 LINKER_SYMBOL_VALUES(file, sym, &symval);
794 if (symval.value == 0)
795 /*
796 * For commons, first look them up in the
797 * dependencies and only allocate space if not found
798 * there.
799 */
800 common_size = symval.size;
801 else {
802 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
803 ".value=%p\n", symval.value));
804 return (symval.value);
805 }
806 }
807 if (deps) {
808 for (i = 0; i < file->ndeps; i++) {
809 address = linker_file_lookup_symbol_internal(
810 file->deps[i], name, 0);
811 if (address) {
812 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
813 " deps value=%p\n", address));
814 return (address);
815 }
816 }
817 }
818 if (common_size > 0) {
819 /*
820 * This is a common symbol which was not found in the
821 * dependencies. We maintain a simple common symbol table in
822 * the file object.
823 */
824 struct common_symbol *cp;
825
826 STAILQ_FOREACH(cp, &file->common, link) {
827 if (strcmp(cp->name, name) == 0) {
828 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
829 " old common value=%p\n", cp->address));
830 return (cp->address);
831 }
832 }
833 /*
834 * Round the symbol size up to align.
835 */
836 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
837 cp = malloc(sizeof(struct common_symbol)
838 + common_size + strlen(name) + 1, M_LINKER,
839 M_WAITOK | M_ZERO);
840 cp->address = (caddr_t)(cp + 1);
841 cp->name = cp->address + common_size;
842 strcpy(cp->name, name);
843 bzero(cp->address, common_size);
844 STAILQ_INSERT_TAIL(&file->common, cp, link);
845
846 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
847 " value=%p\n", cp->address));
848 return (cp->address);
849 }
850 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
851 return (0);
852 }
853
854 /*
855 * Both DDB and stack(9) rely on the kernel linker to provide forward and
856 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
857 * do this in a lockfree manner. We provide a set of internal helper
858 * routines to perform these operations without locks, and then wrappers that
859 * optionally lock.
860 *
861 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
862 */
863 #ifdef DDB
864 static int
865 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
866 {
867 linker_file_t lf;
868
869 TAILQ_FOREACH(lf, &linker_files, link) {
870 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
871 return (0);
872 }
873 return (ENOENT);
874 }
875 #endif
876
877 static int
878 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
879 {
880 linker_file_t lf;
881 c_linker_sym_t best, es;
882 u_long diff, bestdiff, off;
883
884 best = 0;
885 off = (uintptr_t)value;
886 bestdiff = off;
887 TAILQ_FOREACH(lf, &linker_files, link) {
888 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
889 continue;
890 if (es != 0 && diff < bestdiff) {
891 best = es;
892 bestdiff = diff;
893 }
894 if (bestdiff == 0)
895 break;
896 }
897 if (best) {
898 *sym = best;
899 *diffp = bestdiff;
900 return (0);
901 } else {
902 *sym = 0;
903 *diffp = off;
904 return (ENOENT);
905 }
906 }
907
908 static int
909 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
910 {
911 linker_file_t lf;
912
913 TAILQ_FOREACH(lf, &linker_files, link) {
914 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
915 return (0);
916 }
917 return (ENOENT);
918 }
919
920 static int
921 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
922 long *offset)
923 {
924 linker_symval_t symval;
925 c_linker_sym_t sym;
926 int error;
927
928 *offset = 0;
929 error = linker_debug_search_symbol(value, &sym, offset);
930 if (error)
931 return (error);
932 error = linker_debug_symbol_values(sym, &symval);
933 if (error)
934 return (error);
935 strlcpy(buf, symval.name, buflen);
936 return (0);
937 }
938
939 /*
940 * DDB Helpers. DDB has to look across multiple files with their own symbol
941 * tables and string tables.
942 *
943 * Note that we do not obey list locking protocols here. We really don't need
944 * DDB to hang because somebody's got the lock held. We'll take the chance
945 * that the files list is inconsistant instead.
946 */
947 #ifdef DDB
948 int
949 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
950 {
951
952 return (linker_debug_lookup(symstr, sym));
953 }
954 #endif
955
956 int
957 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
958 {
959
960 return (linker_debug_search_symbol(value, sym, diffp));
961 }
962
963 int
964 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
965 {
966
967 return (linker_debug_symbol_values(sym, symval));
968 }
969
970 int
971 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
972 long *offset)
973 {
974
975 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
976 }
977
978 /*
979 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
980 * obey locking protocols, and offer a significantly less complex interface.
981 */
982 int
983 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
984 long *offset)
985 {
986 int error;
987
988 sx_xlock(&kld_sx);
989 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
990 sx_xunlock(&kld_sx);
991 return (error);
992 }
993
994 /*
995 * Syscalls.
996 */
997 int
998 kern_kldload(struct thread *td, const char *file, int *fileid)
999 {
1000 const char *kldname, *modname;
1001 linker_file_t lf;
1002 int error;
1003
1004 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1005 return (error);
1006
1007 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1008 return (error);
1009
1010 /*
1011 * It is possible that kldloaded module will attach a new ifnet,
1012 * so vnet context must be set when this ocurs.
1013 */
1014 CURVNET_SET(TD_TO_VNET(td));
1015
1016 /*
1017 * If file does not contain a qualified name or any dot in it
1018 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1019 * name.
1020 */
1021 if (strchr(file, '/') || strchr(file, '.')) {
1022 kldname = file;
1023 modname = NULL;
1024 } else {
1025 kldname = NULL;
1026 modname = file;
1027 }
1028
1029 sx_xlock(&kld_sx);
1030 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1031 if (error) {
1032 sx_xunlock(&kld_sx);
1033 goto done;
1034 }
1035 lf->userrefs++;
1036 if (fileid != NULL)
1037 *fileid = lf->id;
1038 sx_xunlock(&kld_sx);
1039
1040 done:
1041 CURVNET_RESTORE();
1042 return (error);
1043 }
1044
1045 int
1046 sys_kldload(struct thread *td, struct kldload_args *uap)
1047 {
1048 char *pathname = NULL;
1049 int error, fileid;
1050
1051 td->td_retval[0] = -1;
1052
1053 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1054 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1055 if (error == 0) {
1056 error = kern_kldload(td, pathname, &fileid);
1057 if (error == 0)
1058 td->td_retval[0] = fileid;
1059 }
1060 free(pathname, M_TEMP);
1061 return (error);
1062 }
1063
1064 int
1065 kern_kldunload(struct thread *td, int fileid, int flags)
1066 {
1067 linker_file_t lf;
1068 int error = 0;
1069
1070 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1071 return (error);
1072
1073 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1074 return (error);
1075
1076 CURVNET_SET(TD_TO_VNET(td));
1077 sx_xlock(&kld_sx);
1078 lf = linker_find_file_by_id(fileid);
1079 if (lf) {
1080 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1081
1082 if (lf->userrefs == 0) {
1083 /*
1084 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1085 */
1086 printf("kldunload: attempt to unload file that was"
1087 " loaded by the kernel\n");
1088 error = EBUSY;
1089 } else {
1090 lf->userrefs--;
1091 error = linker_file_unload(lf, flags);
1092 if (error)
1093 lf->userrefs++;
1094 }
1095 } else
1096 error = ENOENT;
1097 sx_xunlock(&kld_sx);
1098
1099 CURVNET_RESTORE();
1100 return (error);
1101 }
1102
1103 int
1104 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1105 {
1106
1107 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1108 }
1109
1110 int
1111 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1112 {
1113
1114 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1115 uap->flags != LINKER_UNLOAD_FORCE)
1116 return (EINVAL);
1117 return (kern_kldunload(td, uap->fileid, uap->flags));
1118 }
1119
1120 int
1121 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1122 {
1123 char *pathname;
1124 const char *filename;
1125 linker_file_t lf;
1126 int error;
1127
1128 #ifdef MAC
1129 error = mac_kld_check_stat(td->td_ucred);
1130 if (error)
1131 return (error);
1132 #endif
1133
1134 td->td_retval[0] = -1;
1135
1136 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1137 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1138 goto out;
1139
1140 filename = linker_basename(pathname);
1141 sx_xlock(&kld_sx);
1142 lf = linker_find_file_by_name(filename);
1143 if (lf)
1144 td->td_retval[0] = lf->id;
1145 else
1146 error = ENOENT;
1147 sx_xunlock(&kld_sx);
1148 out:
1149 free(pathname, M_TEMP);
1150 return (error);
1151 }
1152
1153 int
1154 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1155 {
1156 linker_file_t lf;
1157 int error = 0;
1158
1159 #ifdef MAC
1160 error = mac_kld_check_stat(td->td_ucred);
1161 if (error)
1162 return (error);
1163 #endif
1164
1165 sx_xlock(&kld_sx);
1166 if (uap->fileid == 0)
1167 lf = TAILQ_FIRST(&linker_files);
1168 else {
1169 lf = linker_find_file_by_id(uap->fileid);
1170 if (lf == NULL) {
1171 error = ENOENT;
1172 goto out;
1173 }
1174 lf = TAILQ_NEXT(lf, link);
1175 }
1176
1177 /* Skip partially loaded files. */
1178 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1179 lf = TAILQ_NEXT(lf, link);
1180
1181 if (lf)
1182 td->td_retval[0] = lf->id;
1183 else
1184 td->td_retval[0] = 0;
1185 out:
1186 sx_xunlock(&kld_sx);
1187 return (error);
1188 }
1189
1190 int
1191 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1192 {
1193 struct kld_file_stat stat;
1194 int error, version;
1195
1196 /*
1197 * Check the version of the user's structure.
1198 */
1199 if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1200 != 0)
1201 return (error);
1202 if (version != sizeof(struct kld_file_stat_1) &&
1203 version != sizeof(struct kld_file_stat))
1204 return (EINVAL);
1205
1206 error = kern_kldstat(td, uap->fileid, &stat);
1207 if (error != 0)
1208 return (error);
1209 return (copyout(&stat, uap->stat, version));
1210 }
1211
1212 int
1213 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1214 {
1215 linker_file_t lf;
1216 int namelen;
1217 #ifdef MAC
1218 int error;
1219
1220 error = mac_kld_check_stat(td->td_ucred);
1221 if (error)
1222 return (error);
1223 #endif
1224
1225 sx_xlock(&kld_sx);
1226 lf = linker_find_file_by_id(fileid);
1227 if (lf == NULL) {
1228 sx_xunlock(&kld_sx);
1229 return (ENOENT);
1230 }
1231
1232 /* Version 1 fields: */
1233 namelen = strlen(lf->filename) + 1;
1234 if (namelen > MAXPATHLEN)
1235 namelen = MAXPATHLEN;
1236 bcopy(lf->filename, &stat->name[0], namelen);
1237 stat->refs = lf->refs;
1238 stat->id = lf->id;
1239 stat->address = lf->address;
1240 stat->size = lf->size;
1241 /* Version 2 fields: */
1242 namelen = strlen(lf->pathname) + 1;
1243 if (namelen > MAXPATHLEN)
1244 namelen = MAXPATHLEN;
1245 bcopy(lf->pathname, &stat->pathname[0], namelen);
1246 sx_xunlock(&kld_sx);
1247
1248 td->td_retval[0] = 0;
1249 return (0);
1250 }
1251
1252 int
1253 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1254 {
1255 linker_file_t lf;
1256 module_t mp;
1257 int error = 0;
1258
1259 #ifdef MAC
1260 error = mac_kld_check_stat(td->td_ucred);
1261 if (error)
1262 return (error);
1263 #endif
1264
1265 sx_xlock(&kld_sx);
1266 lf = linker_find_file_by_id(uap->fileid);
1267 if (lf) {
1268 MOD_SLOCK;
1269 mp = TAILQ_FIRST(&lf->modules);
1270 if (mp != NULL)
1271 td->td_retval[0] = module_getid(mp);
1272 else
1273 td->td_retval[0] = 0;
1274 MOD_SUNLOCK;
1275 } else
1276 error = ENOENT;
1277 sx_xunlock(&kld_sx);
1278 return (error);
1279 }
1280
1281 int
1282 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1283 {
1284 char *symstr = NULL;
1285 c_linker_sym_t sym;
1286 linker_symval_t symval;
1287 linker_file_t lf;
1288 struct kld_sym_lookup lookup;
1289 int error = 0;
1290
1291 #ifdef MAC
1292 error = mac_kld_check_stat(td->td_ucred);
1293 if (error)
1294 return (error);
1295 #endif
1296
1297 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1298 return (error);
1299 if (lookup.version != sizeof(lookup) ||
1300 uap->cmd != KLDSYM_LOOKUP)
1301 return (EINVAL);
1302 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1303 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1304 goto out;
1305 sx_xlock(&kld_sx);
1306 if (uap->fileid != 0) {
1307 lf = linker_find_file_by_id(uap->fileid);
1308 if (lf == NULL)
1309 error = ENOENT;
1310 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1311 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1312 lookup.symvalue = (uintptr_t) symval.value;
1313 lookup.symsize = symval.size;
1314 error = copyout(&lookup, uap->data, sizeof(lookup));
1315 } else
1316 error = ENOENT;
1317 } else {
1318 TAILQ_FOREACH(lf, &linker_files, link) {
1319 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1320 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1321 lookup.symvalue = (uintptr_t)symval.value;
1322 lookup.symsize = symval.size;
1323 error = copyout(&lookup, uap->data,
1324 sizeof(lookup));
1325 break;
1326 }
1327 }
1328 if (lf == NULL)
1329 error = ENOENT;
1330 }
1331 sx_xunlock(&kld_sx);
1332 out:
1333 free(symstr, M_TEMP);
1334 return (error);
1335 }
1336
1337 /*
1338 * Preloaded module support
1339 */
1340
1341 static modlist_t
1342 modlist_lookup(const char *name, int ver)
1343 {
1344 modlist_t mod;
1345
1346 TAILQ_FOREACH(mod, &found_modules, link) {
1347 if (strcmp(mod->name, name) == 0 &&
1348 (ver == 0 || mod->version == ver))
1349 return (mod);
1350 }
1351 return (NULL);
1352 }
1353
1354 static modlist_t
1355 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1356 {
1357 modlist_t mod, bestmod;
1358 int ver;
1359
1360 if (verinfo == NULL)
1361 return (modlist_lookup(name, 0));
1362 bestmod = NULL;
1363 TAILQ_FOREACH(mod, &found_modules, link) {
1364 if (strcmp(mod->name, name) != 0)
1365 continue;
1366 ver = mod->version;
1367 if (ver == verinfo->md_ver_preferred)
1368 return (mod);
1369 if (ver >= verinfo->md_ver_minimum &&
1370 ver <= verinfo->md_ver_maximum &&
1371 (bestmod == NULL || ver > bestmod->version))
1372 bestmod = mod;
1373 }
1374 return (bestmod);
1375 }
1376
1377 static modlist_t
1378 modlist_newmodule(const char *modname, int version, linker_file_t container)
1379 {
1380 modlist_t mod;
1381
1382 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1383 if (mod == NULL)
1384 panic("no memory for module list");
1385 mod->container = container;
1386 mod->name = modname;
1387 mod->version = version;
1388 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1389 return (mod);
1390 }
1391
1392 static void
1393 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1394 struct mod_metadata **stop, int preload)
1395 {
1396 struct mod_metadata *mp, **mdp;
1397 const char *modname;
1398 int ver;
1399
1400 for (mdp = start; mdp < stop; mdp++) {
1401 mp = *mdp;
1402 if (mp->md_type != MDT_VERSION)
1403 continue;
1404 modname = mp->md_cval;
1405 ver = ((struct mod_version *)mp->md_data)->mv_version;
1406 if (modlist_lookup(modname, ver) != NULL) {
1407 printf("module %s already present!\n", modname);
1408 /* XXX what can we do? this is a build error. :-( */
1409 continue;
1410 }
1411 modlist_newmodule(modname, ver, lf);
1412 }
1413 }
1414
1415 static void
1416 linker_preload(void *arg)
1417 {
1418 caddr_t modptr;
1419 const char *modname, *nmodname;
1420 char *modtype;
1421 linker_file_t lf, nlf;
1422 linker_class_t lc;
1423 int error;
1424 linker_file_list_t loaded_files;
1425 linker_file_list_t depended_files;
1426 struct mod_metadata *mp, *nmp;
1427 struct mod_metadata **start, **stop, **mdp, **nmdp;
1428 struct mod_depend *verinfo;
1429 int nver;
1430 int resolves;
1431 modlist_t mod;
1432 struct sysinit **si_start, **si_stop;
1433
1434 TAILQ_INIT(&loaded_files);
1435 TAILQ_INIT(&depended_files);
1436 TAILQ_INIT(&found_modules);
1437 error = 0;
1438
1439 modptr = NULL;
1440 sx_xlock(&kld_sx);
1441 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1442 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1443 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1444 if (modname == NULL) {
1445 printf("Preloaded module at %p does not have a"
1446 " name!\n", modptr);
1447 continue;
1448 }
1449 if (modtype == NULL) {
1450 printf("Preloaded module at %p does not have a type!\n",
1451 modptr);
1452 continue;
1453 }
1454 if (bootverbose)
1455 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1456 modptr);
1457 lf = NULL;
1458 TAILQ_FOREACH(lc, &classes, link) {
1459 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1460 if (!error)
1461 break;
1462 lf = NULL;
1463 }
1464 if (lf)
1465 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1466 }
1467
1468 /*
1469 * First get a list of stuff in the kernel.
1470 */
1471 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1472 &stop, NULL) == 0)
1473 linker_addmodules(linker_kernel_file, start, stop, 1);
1474
1475 /*
1476 * This is a once-off kinky bubble sort to resolve relocation
1477 * dependency requirements.
1478 */
1479 restart:
1480 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1481 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1482 &stop, NULL);
1483 /*
1484 * First, look to see if we would successfully link with this
1485 * stuff.
1486 */
1487 resolves = 1; /* unless we know otherwise */
1488 if (!error) {
1489 for (mdp = start; mdp < stop; mdp++) {
1490 mp = *mdp;
1491 if (mp->md_type != MDT_DEPEND)
1492 continue;
1493 modname = mp->md_cval;
1494 verinfo = mp->md_data;
1495 for (nmdp = start; nmdp < stop; nmdp++) {
1496 nmp = *nmdp;
1497 if (nmp->md_type != MDT_VERSION)
1498 continue;
1499 nmodname = nmp->md_cval;
1500 if (strcmp(modname, nmodname) == 0)
1501 break;
1502 }
1503 if (nmdp < stop) /* it's a self reference */
1504 continue;
1505
1506 /*
1507 * ok, the module isn't here yet, we
1508 * are not finished
1509 */
1510 if (modlist_lookup2(modname, verinfo) == NULL)
1511 resolves = 0;
1512 }
1513 }
1514 /*
1515 * OK, if we found our modules, we can link. So, "provide"
1516 * the modules inside and add it to the end of the link order
1517 * list.
1518 */
1519 if (resolves) {
1520 if (!error) {
1521 for (mdp = start; mdp < stop; mdp++) {
1522 mp = *mdp;
1523 if (mp->md_type != MDT_VERSION)
1524 continue;
1525 modname = mp->md_cval;
1526 nver = ((struct mod_version *)
1527 mp->md_data)->mv_version;
1528 if (modlist_lookup(modname,
1529 nver) != NULL) {
1530 printf("module %s already"
1531 " present!\n", modname);
1532 TAILQ_REMOVE(&loaded_files,
1533 lf, loaded);
1534 linker_file_unload(lf,
1535 LINKER_UNLOAD_FORCE);
1536 /* we changed tailq next ptr */
1537 goto restart;
1538 }
1539 modlist_newmodule(modname, nver, lf);
1540 }
1541 }
1542 TAILQ_REMOVE(&loaded_files, lf, loaded);
1543 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1544 /*
1545 * Since we provided modules, we need to restart the
1546 * sort so that the previous files that depend on us
1547 * have a chance. Also, we've busted the tailq next
1548 * pointer with the REMOVE.
1549 */
1550 goto restart;
1551 }
1552 }
1553
1554 /*
1555 * At this point, we check to see what could not be resolved..
1556 */
1557 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1558 TAILQ_REMOVE(&loaded_files, lf, loaded);
1559 printf("KLD file %s is missing dependencies\n", lf->filename);
1560 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1561 }
1562
1563 /*
1564 * We made it. Finish off the linking in the order we determined.
1565 */
1566 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1567 if (linker_kernel_file) {
1568 linker_kernel_file->refs++;
1569 error = linker_file_add_dependency(lf,
1570 linker_kernel_file);
1571 if (error)
1572 panic("cannot add dependency");
1573 }
1574 lf->userrefs++; /* so we can (try to) kldunload it */
1575 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1576 &stop, NULL);
1577 if (!error) {
1578 for (mdp = start; mdp < stop; mdp++) {
1579 mp = *mdp;
1580 if (mp->md_type != MDT_DEPEND)
1581 continue;
1582 modname = mp->md_cval;
1583 verinfo = mp->md_data;
1584 mod = modlist_lookup2(modname, verinfo);
1585 if (mod == NULL) {
1586 printf("KLD file %s - cannot find "
1587 "dependency \"%s\"\n",
1588 lf->filename, modname);
1589 goto fail;
1590 }
1591 /* Don't count self-dependencies */
1592 if (lf == mod->container)
1593 continue;
1594 mod->container->refs++;
1595 error = linker_file_add_dependency(lf,
1596 mod->container);
1597 if (error)
1598 panic("cannot add dependency");
1599 }
1600 }
1601 /*
1602 * Now do relocation etc using the symbol search paths
1603 * established by the dependencies
1604 */
1605 error = LINKER_LINK_PRELOAD_FINISH(lf);
1606 if (error) {
1607 printf("KLD file %s - could not finalize loading\n",
1608 lf->filename);
1609 goto fail;
1610 }
1611 linker_file_register_modules(lf);
1612 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1613 &si_stop, NULL) == 0)
1614 sysinit_add(si_start, si_stop);
1615 linker_file_register_sysctls(lf);
1616 lf->flags |= LINKER_FILE_LINKED;
1617 continue;
1618 fail:
1619 TAILQ_REMOVE(&depended_files, lf, loaded);
1620 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1621 }
1622 sx_xunlock(&kld_sx);
1623 /* woohoo! we made it! */
1624 }
1625
1626 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1627
1628 /*
1629 * Search for a not-loaded module by name.
1630 *
1631 * Modules may be found in the following locations:
1632 *
1633 * - preloaded (result is just the module name) - on disk (result is full path
1634 * to module)
1635 *
1636 * If the module name is qualified in any way (contains path, etc.) the we
1637 * simply return a copy of it.
1638 *
1639 * The search path can be manipulated via sysctl. Note that we use the ';'
1640 * character as a separator to be consistent with the bootloader.
1641 */
1642
1643 static char linker_hintfile[] = "linker.hints";
1644 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1645
1646 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1647 sizeof(linker_path), "module load search path");
1648
1649 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1650
1651 static char *linker_ext_list[] = {
1652 "",
1653 ".ko",
1654 NULL
1655 };
1656
1657 /*
1658 * Check if file actually exists either with or without extension listed in
1659 * the linker_ext_list. (probably should be generic for the rest of the
1660 * kernel)
1661 */
1662 static char *
1663 linker_lookup_file(const char *path, int pathlen, const char *name,
1664 int namelen, struct vattr *vap)
1665 {
1666 struct nameidata nd;
1667 struct thread *td = curthread; /* XXX */
1668 char *result, **cpp, *sep;
1669 int error, len, extlen, reclen, flags;
1670 enum vtype type;
1671
1672 extlen = 0;
1673 for (cpp = linker_ext_list; *cpp; cpp++) {
1674 len = strlen(*cpp);
1675 if (len > extlen)
1676 extlen = len;
1677 }
1678 extlen++; /* trailing '\0' */
1679 sep = (path[pathlen - 1] != '/') ? "/" : "";
1680
1681 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1682 result = malloc(reclen, M_LINKER, M_WAITOK);
1683 for (cpp = linker_ext_list; *cpp; cpp++) {
1684 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1685 namelen, name, *cpp);
1686 /*
1687 * Attempt to open the file, and return the path if
1688 * we succeed and it's a regular file.
1689 */
1690 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1691 flags = FREAD;
1692 error = vn_open(&nd, &flags, 0, NULL);
1693 if (error == 0) {
1694 NDFREE(&nd, NDF_ONLY_PNBUF);
1695 type = nd.ni_vp->v_type;
1696 if (vap)
1697 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1698 VOP_UNLOCK(nd.ni_vp, 0);
1699 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1700 if (type == VREG)
1701 return (result);
1702 }
1703 }
1704 free(result, M_LINKER);
1705 return (NULL);
1706 }
1707
1708 #define INT_ALIGN(base, ptr) ptr = \
1709 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1710
1711 /*
1712 * Lookup KLD which contains requested module in the "linker.hints" file. If
1713 * version specification is available, then try to find the best KLD.
1714 * Otherwise just find the latest one.
1715 */
1716 static char *
1717 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1718 int modnamelen, struct mod_depend *verinfo)
1719 {
1720 struct thread *td = curthread; /* XXX */
1721 struct ucred *cred = td ? td->td_ucred : NULL;
1722 struct nameidata nd;
1723 struct vattr vattr, mattr;
1724 u_char *hints = NULL;
1725 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1726 int error, ival, bestver, *intp, found, flags, clen, blen;
1727 ssize_t reclen;
1728
1729 result = NULL;
1730 bestver = found = 0;
1731
1732 sep = (path[pathlen - 1] != '/') ? "/" : "";
1733 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1734 strlen(sep) + 1;
1735 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1736 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1737 linker_hintfile);
1738
1739 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1740 flags = FREAD;
1741 error = vn_open(&nd, &flags, 0, NULL);
1742 if (error)
1743 goto bad;
1744 NDFREE(&nd, NDF_ONLY_PNBUF);
1745 if (nd.ni_vp->v_type != VREG)
1746 goto bad;
1747 best = cp = NULL;
1748 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1749 if (error)
1750 goto bad;
1751 /*
1752 * XXX: we need to limit this number to some reasonable value
1753 */
1754 if (vattr.va_size > 100 * 1024) {
1755 printf("hints file too large %ld\n", (long)vattr.va_size);
1756 goto bad;
1757 }
1758 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1759 if (hints == NULL)
1760 goto bad;
1761 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1762 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1763 if (error)
1764 goto bad;
1765 VOP_UNLOCK(nd.ni_vp, 0);
1766 vn_close(nd.ni_vp, FREAD, cred, td);
1767 nd.ni_vp = NULL;
1768 if (reclen != 0) {
1769 printf("can't read %zd\n", reclen);
1770 goto bad;
1771 }
1772 intp = (int *)hints;
1773 ival = *intp++;
1774 if (ival != LINKER_HINTS_VERSION) {
1775 printf("hints file version mismatch %d\n", ival);
1776 goto bad;
1777 }
1778 bufend = hints + vattr.va_size;
1779 recptr = (u_char *)intp;
1780 clen = blen = 0;
1781 while (recptr < bufend && !found) {
1782 intp = (int *)recptr;
1783 reclen = *intp++;
1784 ival = *intp++;
1785 cp = (char *)intp;
1786 switch (ival) {
1787 case MDT_VERSION:
1788 clen = *cp++;
1789 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1790 break;
1791 cp += clen;
1792 INT_ALIGN(hints, cp);
1793 ival = *(int *)cp;
1794 cp += sizeof(int);
1795 clen = *cp++;
1796 if (verinfo == NULL ||
1797 ival == verinfo->md_ver_preferred) {
1798 found = 1;
1799 break;
1800 }
1801 if (ival >= verinfo->md_ver_minimum &&
1802 ival <= verinfo->md_ver_maximum &&
1803 ival > bestver) {
1804 bestver = ival;
1805 best = cp;
1806 blen = clen;
1807 }
1808 break;
1809 default:
1810 break;
1811 }
1812 recptr += reclen + sizeof(int);
1813 }
1814 /*
1815 * Finally check if KLD is in the place
1816 */
1817 if (found)
1818 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1819 else if (best)
1820 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1821
1822 /*
1823 * KLD is newer than hints file. What we should do now?
1824 */
1825 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1826 printf("warning: KLD '%s' is newer than the linker.hints"
1827 " file\n", result);
1828 bad:
1829 free(pathbuf, M_LINKER);
1830 if (hints)
1831 free(hints, M_TEMP);
1832 if (nd.ni_vp != NULL) {
1833 VOP_UNLOCK(nd.ni_vp, 0);
1834 vn_close(nd.ni_vp, FREAD, cred, td);
1835 }
1836 /*
1837 * If nothing found or hints is absent - fallback to the old
1838 * way by using "kldname[.ko]" as module name.
1839 */
1840 if (!found && !bestver && result == NULL)
1841 result = linker_lookup_file(path, pathlen, modname,
1842 modnamelen, NULL);
1843 return (result);
1844 }
1845
1846 /*
1847 * Lookup KLD which contains requested module in the all directories.
1848 */
1849 static char *
1850 linker_search_module(const char *modname, int modnamelen,
1851 struct mod_depend *verinfo)
1852 {
1853 char *cp, *ep, *result;
1854
1855 /*
1856 * traverse the linker path
1857 */
1858 for (cp = linker_path; *cp; cp = ep + 1) {
1859 /* find the end of this component */
1860 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1861 result = linker_hints_lookup(cp, ep - cp, modname,
1862 modnamelen, verinfo);
1863 if (result != NULL)
1864 return (result);
1865 if (*ep == 0)
1866 break;
1867 }
1868 return (NULL);
1869 }
1870
1871 /*
1872 * Search for module in all directories listed in the linker_path.
1873 */
1874 static char *
1875 linker_search_kld(const char *name)
1876 {
1877 char *cp, *ep, *result;
1878 int len;
1879
1880 /* qualified at all? */
1881 if (strchr(name, '/'))
1882 return (strdup(name, M_LINKER));
1883
1884 /* traverse the linker path */
1885 len = strlen(name);
1886 for (ep = linker_path; *ep; ep++) {
1887 cp = ep;
1888 /* find the end of this component */
1889 for (; *ep != 0 && *ep != ';'; ep++);
1890 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1891 if (result != NULL)
1892 return (result);
1893 }
1894 return (NULL);
1895 }
1896
1897 static const char *
1898 linker_basename(const char *path)
1899 {
1900 const char *filename;
1901
1902 filename = strrchr(path, '/');
1903 if (filename == NULL)
1904 return path;
1905 if (filename[1])
1906 filename++;
1907 return (filename);
1908 }
1909
1910 #ifdef HWPMC_HOOKS
1911 /*
1912 * Inform hwpmc about the set of kernel modules currently loaded.
1913 */
1914 void *
1915 linker_hwpmc_list_objects(void)
1916 {
1917 linker_file_t lf;
1918 struct pmckern_map_in *kobase;
1919 int i, nmappings;
1920
1921 nmappings = 0;
1922 sx_slock(&kld_sx);
1923 TAILQ_FOREACH(lf, &linker_files, link)
1924 nmappings++;
1925
1926 /* Allocate nmappings + 1 entries. */
1927 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1928 M_LINKER, M_WAITOK | M_ZERO);
1929 i = 0;
1930 TAILQ_FOREACH(lf, &linker_files, link) {
1931
1932 /* Save the info for this linker file. */
1933 kobase[i].pm_file = lf->filename;
1934 kobase[i].pm_address = (uintptr_t)lf->address;
1935 i++;
1936 }
1937 sx_sunlock(&kld_sx);
1938
1939 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1940
1941 /* The last entry of the malloced area comprises of all zeros. */
1942 KASSERT(kobase[i].pm_file == NULL,
1943 ("linker_hwpmc_list_objects: last object not NULL"));
1944
1945 return ((void *)kobase);
1946 }
1947 #endif
1948
1949 /*
1950 * Find a file which contains given module and load it, if "parent" is not
1951 * NULL, register a reference to it.
1952 */
1953 static int
1954 linker_load_module(const char *kldname, const char *modname,
1955 struct linker_file *parent, struct mod_depend *verinfo,
1956 struct linker_file **lfpp)
1957 {
1958 linker_file_t lfdep;
1959 const char *filename;
1960 char *pathname;
1961 int error;
1962
1963 sx_assert(&kld_sx, SA_XLOCKED);
1964 if (modname == NULL) {
1965 /*
1966 * We have to load KLD
1967 */
1968 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1969 " is not NULL"));
1970 pathname = linker_search_kld(kldname);
1971 } else {
1972 if (modlist_lookup2(modname, verinfo) != NULL)
1973 return (EEXIST);
1974 if (kldname != NULL)
1975 pathname = strdup(kldname, M_LINKER);
1976 else if (rootvnode == NULL)
1977 pathname = NULL;
1978 else
1979 /*
1980 * Need to find a KLD with required module
1981 */
1982 pathname = linker_search_module(modname,
1983 strlen(modname), verinfo);
1984 }
1985 if (pathname == NULL)
1986 return (ENOENT);
1987
1988 /*
1989 * Can't load more than one file with the same basename XXX:
1990 * Actually it should be possible to have multiple KLDs with
1991 * the same basename but different path because they can
1992 * provide different versions of the same modules.
1993 */
1994 filename = linker_basename(pathname);
1995 if (linker_find_file_by_name(filename))
1996 error = EEXIST;
1997 else do {
1998 error = linker_load_file(pathname, &lfdep);
1999 if (error)
2000 break;
2001 if (modname && verinfo &&
2002 modlist_lookup2(modname, verinfo) == NULL) {
2003 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2004 error = ENOENT;
2005 break;
2006 }
2007 if (parent) {
2008 error = linker_file_add_dependency(parent, lfdep);
2009 if (error)
2010 break;
2011 }
2012 if (lfpp)
2013 *lfpp = lfdep;
2014 } while (0);
2015 free(pathname, M_LINKER);
2016 return (error);
2017 }
2018
2019 /*
2020 * This routine is responsible for finding dependencies of userland initiated
2021 * kldload(2)'s of files.
2022 */
2023 int
2024 linker_load_dependencies(linker_file_t lf)
2025 {
2026 linker_file_t lfdep;
2027 struct mod_metadata **start, **stop, **mdp, **nmdp;
2028 struct mod_metadata *mp, *nmp;
2029 struct mod_depend *verinfo;
2030 modlist_t mod;
2031 const char *modname, *nmodname;
2032 int ver, error = 0, count;
2033
2034 /*
2035 * All files are dependant on /kernel.
2036 */
2037 sx_assert(&kld_sx, SA_XLOCKED);
2038 if (linker_kernel_file) {
2039 linker_kernel_file->refs++;
2040 error = linker_file_add_dependency(lf, linker_kernel_file);
2041 if (error)
2042 return (error);
2043 }
2044 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2045 &count) != 0)
2046 return (0);
2047 for (mdp = start; mdp < stop; mdp++) {
2048 mp = *mdp;
2049 if (mp->md_type != MDT_VERSION)
2050 continue;
2051 modname = mp->md_cval;
2052 ver = ((struct mod_version *)mp->md_data)->mv_version;
2053 mod = modlist_lookup(modname, ver);
2054 if (mod != NULL) {
2055 printf("interface %s.%d already present in the KLD"
2056 " '%s'!\n", modname, ver,
2057 mod->container->filename);
2058 return (EEXIST);
2059 }
2060 }
2061
2062 for (mdp = start; mdp < stop; mdp++) {
2063 mp = *mdp;
2064 if (mp->md_type != MDT_DEPEND)
2065 continue;
2066 modname = mp->md_cval;
2067 verinfo = mp->md_data;
2068 nmodname = NULL;
2069 for (nmdp = start; nmdp < stop; nmdp++) {
2070 nmp = *nmdp;
2071 if (nmp->md_type != MDT_VERSION)
2072 continue;
2073 nmodname = nmp->md_cval;
2074 if (strcmp(modname, nmodname) == 0)
2075 break;
2076 }
2077 if (nmdp < stop)/* early exit, it's a self reference */
2078 continue;
2079 mod = modlist_lookup2(modname, verinfo);
2080 if (mod) { /* woohoo, it's loaded already */
2081 lfdep = mod->container;
2082 lfdep->refs++;
2083 error = linker_file_add_dependency(lf, lfdep);
2084 if (error)
2085 break;
2086 continue;
2087 }
2088 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2089 if (error) {
2090 printf("KLD %s: depends on %s - not available or"
2091 " version mismatch\n", lf->filename, modname);
2092 break;
2093 }
2094 }
2095
2096 if (error)
2097 return (error);
2098 linker_addmodules(lf, start, stop, 0);
2099 return (error);
2100 }
2101
2102 static int
2103 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2104 {
2105 struct sysctl_req *req;
2106
2107 req = opaque;
2108 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2109 }
2110
2111 /*
2112 * Export a nul-separated, double-nul-terminated list of all function names
2113 * in the kernel.
2114 */
2115 static int
2116 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2117 {
2118 linker_file_t lf;
2119 int error;
2120
2121 #ifdef MAC
2122 error = mac_kld_check_stat(req->td->td_ucred);
2123 if (error)
2124 return (error);
2125 #endif
2126 error = sysctl_wire_old_buffer(req, 0);
2127 if (error != 0)
2128 return (error);
2129 sx_xlock(&kld_sx);
2130 TAILQ_FOREACH(lf, &linker_files, link) {
2131 error = LINKER_EACH_FUNCTION_NAME(lf,
2132 sysctl_kern_function_list_iterate, req);
2133 if (error) {
2134 sx_xunlock(&kld_sx);
2135 return (error);
2136 }
2137 }
2138 sx_xunlock(&kld_sx);
2139 return (SYSCTL_OUT(req, "", 1));
2140 }
2141
2142 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2143 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: bf571373a93b261943027e3b050adb08
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