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/10.0/sys/kern/kern_linker.c 254813 2013-08-24 21:13:38Z markj $");
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 *result = lf;
438 return (0);
439 }
440 }
441 /*
442 * Less than ideal, but tells the user whether it failed to load or
443 * the module was not found.
444 */
445 if (foundfile) {
446
447 /*
448 * If the file type has not been recognized by the last try
449 * printout a message before to fail.
450 */
451 if (error == ENOSYS)
452 printf("linker_load_file: Unsupported file type\n");
453
454 /*
455 * Format not recognized or otherwise unloadable.
456 * When loading a module that is statically built into
457 * the kernel EEXIST percolates back up as the return
458 * value. Preserve this so that apps like sysinstall
459 * can recognize this special case and not post bogus
460 * dialog boxes.
461 */
462 if (error != EEXIST)
463 error = ENOEXEC;
464 } else
465 error = ENOENT; /* Nothing found */
466 return (error);
467 }
468
469 int
470 linker_reference_module(const char *modname, struct mod_depend *verinfo,
471 linker_file_t *result)
472 {
473 modlist_t mod;
474 int error;
475
476 sx_xlock(&kld_sx);
477 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
478 *result = mod->container;
479 (*result)->refs++;
480 sx_xunlock(&kld_sx);
481 return (0);
482 }
483
484 error = linker_load_module(NULL, modname, NULL, verinfo, result);
485 sx_xunlock(&kld_sx);
486 return (error);
487 }
488
489 int
490 linker_release_module(const char *modname, struct mod_depend *verinfo,
491 linker_file_t lf)
492 {
493 modlist_t mod;
494 int error;
495
496 sx_xlock(&kld_sx);
497 if (lf == NULL) {
498 KASSERT(modname != NULL,
499 ("linker_release_module: no file or name"));
500 mod = modlist_lookup2(modname, verinfo);
501 if (mod == NULL) {
502 sx_xunlock(&kld_sx);
503 return (ESRCH);
504 }
505 lf = mod->container;
506 } else
507 KASSERT(modname == NULL && verinfo == NULL,
508 ("linker_release_module: both file and name"));
509 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
510 sx_xunlock(&kld_sx);
511 return (error);
512 }
513
514 static linker_file_t
515 linker_find_file_by_name(const char *filename)
516 {
517 linker_file_t lf;
518 char *koname;
519
520 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
521 sprintf(koname, "%s.ko", filename);
522
523 sx_assert(&kld_sx, SA_XLOCKED);
524 TAILQ_FOREACH(lf, &linker_files, link) {
525 if (strcmp(lf->filename, koname) == 0)
526 break;
527 if (strcmp(lf->filename, filename) == 0)
528 break;
529 }
530 free(koname, M_LINKER);
531 return (lf);
532 }
533
534 static linker_file_t
535 linker_find_file_by_id(int fileid)
536 {
537 linker_file_t lf;
538
539 sx_assert(&kld_sx, SA_XLOCKED);
540 TAILQ_FOREACH(lf, &linker_files, link)
541 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
542 break;
543 return (lf);
544 }
545
546 int
547 linker_file_foreach(linker_predicate_t *predicate, void *context)
548 {
549 linker_file_t lf;
550 int retval = 0;
551
552 sx_xlock(&kld_sx);
553 TAILQ_FOREACH(lf, &linker_files, link) {
554 retval = predicate(lf, context);
555 if (retval != 0)
556 break;
557 }
558 sx_xunlock(&kld_sx);
559 return (retval);
560 }
561
562 linker_file_t
563 linker_make_file(const char *pathname, linker_class_t lc)
564 {
565 linker_file_t lf;
566 const char *filename;
567
568 if (!cold)
569 sx_assert(&kld_sx, SA_XLOCKED);
570 filename = linker_basename(pathname);
571
572 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
573 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
574 if (lf == NULL)
575 return (NULL);
576 lf->refs = 1;
577 lf->userrefs = 0;
578 lf->flags = 0;
579 lf->filename = strdup(filename, M_LINKER);
580 lf->pathname = strdup(pathname, M_LINKER);
581 LINKER_GET_NEXT_FILE_ID(lf->id);
582 lf->ndeps = 0;
583 lf->deps = NULL;
584 lf->loadcnt = ++loadcnt;
585 STAILQ_INIT(&lf->common);
586 TAILQ_INIT(&lf->modules);
587 TAILQ_INSERT_TAIL(&linker_files, lf, link);
588 return (lf);
589 }
590
591 int
592 linker_file_unload(linker_file_t file, int flags)
593 {
594 module_t mod, next;
595 modlist_t ml, nextml;
596 struct common_symbol *cp;
597 int error, i;
598
599 /* Refuse to unload modules if securelevel raised. */
600 if (prison0.pr_securelevel > 0)
601 return (EPERM);
602
603 sx_assert(&kld_sx, SA_XLOCKED);
604 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
605
606 /* Easy case of just dropping a reference. */
607 if (file->refs > 1) {
608 file->refs--;
609 return (0);
610 }
611
612 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
613 " informing modules\n"));
614
615 /*
616 * Quiesce all the modules to give them a chance to veto the unload.
617 */
618 MOD_SLOCK;
619 for (mod = TAILQ_FIRST(&file->modules); mod;
620 mod = module_getfnext(mod)) {
621
622 error = module_quiesce(mod);
623 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
624 KLD_DPF(FILE, ("linker_file_unload: module %s"
625 " vetoed unload\n", module_getname(mod)));
626 /*
627 * XXX: Do we need to tell all the quiesced modules
628 * that they can resume work now via a new module
629 * event?
630 */
631 MOD_SUNLOCK;
632 return (error);
633 }
634 }
635 MOD_SUNLOCK;
636
637 /*
638 * Inform any modules associated with this file that they are
639 * being unloaded.
640 */
641 MOD_XLOCK;
642 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
643 next = module_getfnext(mod);
644 MOD_XUNLOCK;
645
646 /*
647 * Give the module a chance to veto the unload.
648 */
649 if ((error = module_unload(mod)) != 0) {
650 #ifdef KLD_DEBUG
651 MOD_SLOCK;
652 KLD_DPF(FILE, ("linker_file_unload: module %s"
653 " failed unload\n", module_getname(mod)));
654 MOD_SUNLOCK;
655 #endif
656 return (error);
657 }
658 MOD_XLOCK;
659 module_release(mod);
660 }
661 MOD_XUNLOCK;
662
663 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
664 if (ml->container == file) {
665 TAILQ_REMOVE(&found_modules, ml, link);
666 free(ml, M_LINKER);
667 }
668 }
669
670 /*
671 * Don't try to run SYSUNINITs if we are unloaded due to a
672 * link error.
673 */
674 if (file->flags & LINKER_FILE_LINKED) {
675 file->flags &= ~LINKER_FILE_LINKED;
676 linker_file_sysuninit(file);
677 linker_file_unregister_sysctls(file);
678 }
679 TAILQ_REMOVE(&linker_files, file, link);
680
681 if (file->deps) {
682 for (i = 0; i < file->ndeps; i++)
683 linker_file_unload(file->deps[i], flags);
684 free(file->deps, M_LINKER);
685 file->deps = NULL;
686 }
687 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
688 STAILQ_REMOVE_HEAD(&file->common, link);
689 free(cp, M_LINKER);
690 }
691
692 LINKER_UNLOAD(file);
693 if (file->filename) {
694 free(file->filename, M_LINKER);
695 file->filename = NULL;
696 }
697 if (file->pathname) {
698 free(file->pathname, M_LINKER);
699 file->pathname = NULL;
700 }
701 kobj_delete((kobj_t) file, M_LINKER);
702 return (0);
703 }
704
705 int
706 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
707 {
708 return (LINKER_CTF_GET(file, lc));
709 }
710
711 static int
712 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
713 {
714 linker_file_t *newdeps;
715
716 sx_assert(&kld_sx, SA_XLOCKED);
717 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
718 M_LINKER, M_WAITOK | M_ZERO);
719 if (newdeps == NULL)
720 return (ENOMEM);
721
722 if (file->deps) {
723 bcopy(file->deps, newdeps,
724 file->ndeps * sizeof(linker_file_t *));
725 free(file->deps, M_LINKER);
726 }
727 file->deps = newdeps;
728 file->deps[file->ndeps] = dep;
729 file->ndeps++;
730 KLD_DPF(FILE, ("linker_file_add_dependency:"
731 " adding %s as dependency for %s\n",
732 dep->filename, file->filename));
733 return (0);
734 }
735
736 /*
737 * Locate a linker set and its contents. This is a helper function to avoid
738 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
739 * This function is used in this file so we can avoid having lots of (void **)
740 * casts.
741 */
742 int
743 linker_file_lookup_set(linker_file_t file, const char *name,
744 void *firstp, void *lastp, int *countp)
745 {
746
747 sx_assert(&kld_sx, SA_LOCKED);
748 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
749 }
750
751 /*
752 * List all functions in a file.
753 */
754 int
755 linker_file_function_listall(linker_file_t lf,
756 linker_function_nameval_callback_t callback_func, void *arg)
757 {
758 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
759 }
760
761 caddr_t
762 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
763 {
764 caddr_t sym;
765 int locked;
766
767 locked = sx_xlocked(&kld_sx);
768 if (!locked)
769 sx_xlock(&kld_sx);
770 sym = linker_file_lookup_symbol_internal(file, name, deps);
771 if (!locked)
772 sx_xunlock(&kld_sx);
773 return (sym);
774 }
775
776 static caddr_t
777 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
778 int deps)
779 {
780 c_linker_sym_t sym;
781 linker_symval_t symval;
782 caddr_t address;
783 size_t common_size = 0;
784 int i;
785
786 sx_assert(&kld_sx, SA_XLOCKED);
787 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
788 file, name, deps));
789
790 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
791 LINKER_SYMBOL_VALUES(file, sym, &symval);
792 if (symval.value == 0)
793 /*
794 * For commons, first look them up in the
795 * dependencies and only allocate space if not found
796 * there.
797 */
798 common_size = symval.size;
799 else {
800 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
801 ".value=%p\n", symval.value));
802 return (symval.value);
803 }
804 }
805 if (deps) {
806 for (i = 0; i < file->ndeps; i++) {
807 address = linker_file_lookup_symbol_internal(
808 file->deps[i], name, 0);
809 if (address) {
810 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
811 " deps value=%p\n", address));
812 return (address);
813 }
814 }
815 }
816 if (common_size > 0) {
817 /*
818 * This is a common symbol which was not found in the
819 * dependencies. We maintain a simple common symbol table in
820 * the file object.
821 */
822 struct common_symbol *cp;
823
824 STAILQ_FOREACH(cp, &file->common, link) {
825 if (strcmp(cp->name, name) == 0) {
826 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
827 " old common value=%p\n", cp->address));
828 return (cp->address);
829 }
830 }
831 /*
832 * Round the symbol size up to align.
833 */
834 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
835 cp = malloc(sizeof(struct common_symbol)
836 + common_size + strlen(name) + 1, M_LINKER,
837 M_WAITOK | M_ZERO);
838 cp->address = (caddr_t)(cp + 1);
839 cp->name = cp->address + common_size;
840 strcpy(cp->name, name);
841 bzero(cp->address, common_size);
842 STAILQ_INSERT_TAIL(&file->common, cp, link);
843
844 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
845 " value=%p\n", cp->address));
846 return (cp->address);
847 }
848 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
849 return (0);
850 }
851
852 /*
853 * Both DDB and stack(9) rely on the kernel linker to provide forward and
854 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
855 * do this in a lockfree manner. We provide a set of internal helper
856 * routines to perform these operations without locks, and then wrappers that
857 * optionally lock.
858 *
859 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
860 */
861 #ifdef DDB
862 static int
863 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
864 {
865 linker_file_t lf;
866
867 TAILQ_FOREACH(lf, &linker_files, link) {
868 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
869 return (0);
870 }
871 return (ENOENT);
872 }
873 #endif
874
875 static int
876 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
877 {
878 linker_file_t lf;
879 c_linker_sym_t best, es;
880 u_long diff, bestdiff, off;
881
882 best = 0;
883 off = (uintptr_t)value;
884 bestdiff = off;
885 TAILQ_FOREACH(lf, &linker_files, link) {
886 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
887 continue;
888 if (es != 0 && diff < bestdiff) {
889 best = es;
890 bestdiff = diff;
891 }
892 if (bestdiff == 0)
893 break;
894 }
895 if (best) {
896 *sym = best;
897 *diffp = bestdiff;
898 return (0);
899 } else {
900 *sym = 0;
901 *diffp = off;
902 return (ENOENT);
903 }
904 }
905
906 static int
907 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
908 {
909 linker_file_t lf;
910
911 TAILQ_FOREACH(lf, &linker_files, link) {
912 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
913 return (0);
914 }
915 return (ENOENT);
916 }
917
918 static int
919 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
920 long *offset)
921 {
922 linker_symval_t symval;
923 c_linker_sym_t sym;
924 int error;
925
926 *offset = 0;
927 error = linker_debug_search_symbol(value, &sym, offset);
928 if (error)
929 return (error);
930 error = linker_debug_symbol_values(sym, &symval);
931 if (error)
932 return (error);
933 strlcpy(buf, symval.name, buflen);
934 return (0);
935 }
936
937 /*
938 * DDB Helpers. DDB has to look across multiple files with their own symbol
939 * tables and string tables.
940 *
941 * Note that we do not obey list locking protocols here. We really don't need
942 * DDB to hang because somebody's got the lock held. We'll take the chance
943 * that the files list is inconsistant instead.
944 */
945 #ifdef DDB
946 int
947 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
948 {
949
950 return (linker_debug_lookup(symstr, sym));
951 }
952 #endif
953
954 int
955 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
956 {
957
958 return (linker_debug_search_symbol(value, sym, diffp));
959 }
960
961 int
962 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
963 {
964
965 return (linker_debug_symbol_values(sym, symval));
966 }
967
968 int
969 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
970 long *offset)
971 {
972
973 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
974 }
975
976 /*
977 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
978 * obey locking protocols, and offer a significantly less complex interface.
979 */
980 int
981 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
982 long *offset)
983 {
984 int error;
985
986 sx_xlock(&kld_sx);
987 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
988 sx_xunlock(&kld_sx);
989 return (error);
990 }
991
992 /*
993 * Syscalls.
994 */
995 int
996 kern_kldload(struct thread *td, const char *file, int *fileid)
997 {
998 const char *kldname, *modname;
999 linker_file_t lf;
1000 int error;
1001
1002 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1003 return (error);
1004
1005 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1006 return (error);
1007
1008 /*
1009 * It is possible that kldloaded module will attach a new ifnet,
1010 * so vnet context must be set when this ocurs.
1011 */
1012 CURVNET_SET(TD_TO_VNET(td));
1013
1014 /*
1015 * If file does not contain a qualified name or any dot in it
1016 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1017 * name.
1018 */
1019 if (strchr(file, '/') || strchr(file, '.')) {
1020 kldname = file;
1021 modname = NULL;
1022 } else {
1023 kldname = NULL;
1024 modname = file;
1025 }
1026
1027 sx_xlock(&kld_sx);
1028 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1029 if (error) {
1030 sx_xunlock(&kld_sx);
1031 goto done;
1032 }
1033 lf->userrefs++;
1034 if (fileid != NULL)
1035 *fileid = lf->id;
1036
1037 sx_downgrade(&kld_sx);
1038 EVENTHANDLER_INVOKE(kld_load, lf);
1039 sx_sunlock(&kld_sx);
1040
1041 done:
1042 CURVNET_RESTORE();
1043 return (error);
1044 }
1045
1046 int
1047 sys_kldload(struct thread *td, struct kldload_args *uap)
1048 {
1049 char *pathname = NULL;
1050 int error, fileid;
1051
1052 td->td_retval[0] = -1;
1053
1054 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1055 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1056 if (error == 0) {
1057 error = kern_kldload(td, pathname, &fileid);
1058 if (error == 0)
1059 td->td_retval[0] = fileid;
1060 }
1061 free(pathname, M_TEMP);
1062 return (error);
1063 }
1064
1065 int
1066 kern_kldunload(struct thread *td, int fileid, int flags)
1067 {
1068 linker_file_t lf;
1069 char *filename = NULL;
1070 caddr_t address;
1071 size_t size;
1072 int error = 0;
1073
1074 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1075 return (error);
1076
1077 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1078 return (error);
1079
1080 CURVNET_SET(TD_TO_VNET(td));
1081 sx_xlock(&kld_sx);
1082 lf = linker_find_file_by_id(fileid);
1083 if (lf) {
1084 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1085
1086 EVENTHANDLER_INVOKE(kld_unload_try, lf, &error);
1087 if (error != 0)
1088 error = EBUSY;
1089 else if (lf->userrefs == 0) {
1090 /*
1091 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1092 */
1093 printf("kldunload: attempt to unload file that was"
1094 " loaded by the kernel\n");
1095 error = EBUSY;
1096 } else {
1097 /* Save data needed for the kld_unload callbacks. */
1098 filename = strdup(lf->filename, M_TEMP);
1099 address = lf->address;
1100 size = lf->size;
1101
1102 lf->userrefs--;
1103 error = linker_file_unload(lf, flags);
1104 if (error)
1105 lf->userrefs++;
1106 }
1107 } else
1108 error = ENOENT;
1109
1110 if (error == 0) {
1111 sx_downgrade(&kld_sx);
1112 EVENTHANDLER_INVOKE(kld_unload, filename, address, size);
1113 sx_sunlock(&kld_sx);
1114 } else
1115 sx_xunlock(&kld_sx);
1116 free(filename, M_TEMP);
1117
1118 CURVNET_RESTORE();
1119 return (error);
1120 }
1121
1122 int
1123 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1124 {
1125
1126 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1127 }
1128
1129 int
1130 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1131 {
1132
1133 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1134 uap->flags != LINKER_UNLOAD_FORCE)
1135 return (EINVAL);
1136 return (kern_kldunload(td, uap->fileid, uap->flags));
1137 }
1138
1139 int
1140 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1141 {
1142 char *pathname;
1143 const char *filename;
1144 linker_file_t lf;
1145 int error;
1146
1147 #ifdef MAC
1148 error = mac_kld_check_stat(td->td_ucred);
1149 if (error)
1150 return (error);
1151 #endif
1152
1153 td->td_retval[0] = -1;
1154
1155 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1156 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1157 goto out;
1158
1159 filename = linker_basename(pathname);
1160 sx_xlock(&kld_sx);
1161 lf = linker_find_file_by_name(filename);
1162 if (lf)
1163 td->td_retval[0] = lf->id;
1164 else
1165 error = ENOENT;
1166 sx_xunlock(&kld_sx);
1167 out:
1168 free(pathname, M_TEMP);
1169 return (error);
1170 }
1171
1172 int
1173 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1174 {
1175 linker_file_t lf;
1176 int error = 0;
1177
1178 #ifdef MAC
1179 error = mac_kld_check_stat(td->td_ucred);
1180 if (error)
1181 return (error);
1182 #endif
1183
1184 sx_xlock(&kld_sx);
1185 if (uap->fileid == 0)
1186 lf = TAILQ_FIRST(&linker_files);
1187 else {
1188 lf = linker_find_file_by_id(uap->fileid);
1189 if (lf == NULL) {
1190 error = ENOENT;
1191 goto out;
1192 }
1193 lf = TAILQ_NEXT(lf, link);
1194 }
1195
1196 /* Skip partially loaded files. */
1197 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1198 lf = TAILQ_NEXT(lf, link);
1199
1200 if (lf)
1201 td->td_retval[0] = lf->id;
1202 else
1203 td->td_retval[0] = 0;
1204 out:
1205 sx_xunlock(&kld_sx);
1206 return (error);
1207 }
1208
1209 int
1210 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1211 {
1212 struct kld_file_stat stat;
1213 int error, version;
1214
1215 /*
1216 * Check the version of the user's structure.
1217 */
1218 if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1219 != 0)
1220 return (error);
1221 if (version != sizeof(struct kld_file_stat_1) &&
1222 version != sizeof(struct kld_file_stat))
1223 return (EINVAL);
1224
1225 error = kern_kldstat(td, uap->fileid, &stat);
1226 if (error != 0)
1227 return (error);
1228 return (copyout(&stat, uap->stat, version));
1229 }
1230
1231 int
1232 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1233 {
1234 linker_file_t lf;
1235 int namelen;
1236 #ifdef MAC
1237 int error;
1238
1239 error = mac_kld_check_stat(td->td_ucred);
1240 if (error)
1241 return (error);
1242 #endif
1243
1244 sx_xlock(&kld_sx);
1245 lf = linker_find_file_by_id(fileid);
1246 if (lf == NULL) {
1247 sx_xunlock(&kld_sx);
1248 return (ENOENT);
1249 }
1250
1251 /* Version 1 fields: */
1252 namelen = strlen(lf->filename) + 1;
1253 if (namelen > MAXPATHLEN)
1254 namelen = MAXPATHLEN;
1255 bcopy(lf->filename, &stat->name[0], namelen);
1256 stat->refs = lf->refs;
1257 stat->id = lf->id;
1258 stat->address = lf->address;
1259 stat->size = lf->size;
1260 /* Version 2 fields: */
1261 namelen = strlen(lf->pathname) + 1;
1262 if (namelen > MAXPATHLEN)
1263 namelen = MAXPATHLEN;
1264 bcopy(lf->pathname, &stat->pathname[0], namelen);
1265 sx_xunlock(&kld_sx);
1266
1267 td->td_retval[0] = 0;
1268 return (0);
1269 }
1270
1271 int
1272 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1273 {
1274 linker_file_t lf;
1275 module_t mp;
1276 int error = 0;
1277
1278 #ifdef MAC
1279 error = mac_kld_check_stat(td->td_ucred);
1280 if (error)
1281 return (error);
1282 #endif
1283
1284 sx_xlock(&kld_sx);
1285 lf = linker_find_file_by_id(uap->fileid);
1286 if (lf) {
1287 MOD_SLOCK;
1288 mp = TAILQ_FIRST(&lf->modules);
1289 if (mp != NULL)
1290 td->td_retval[0] = module_getid(mp);
1291 else
1292 td->td_retval[0] = 0;
1293 MOD_SUNLOCK;
1294 } else
1295 error = ENOENT;
1296 sx_xunlock(&kld_sx);
1297 return (error);
1298 }
1299
1300 int
1301 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1302 {
1303 char *symstr = NULL;
1304 c_linker_sym_t sym;
1305 linker_symval_t symval;
1306 linker_file_t lf;
1307 struct kld_sym_lookup lookup;
1308 int error = 0;
1309
1310 #ifdef MAC
1311 error = mac_kld_check_stat(td->td_ucred);
1312 if (error)
1313 return (error);
1314 #endif
1315
1316 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1317 return (error);
1318 if (lookup.version != sizeof(lookup) ||
1319 uap->cmd != KLDSYM_LOOKUP)
1320 return (EINVAL);
1321 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1322 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1323 goto out;
1324 sx_xlock(&kld_sx);
1325 if (uap->fileid != 0) {
1326 lf = linker_find_file_by_id(uap->fileid);
1327 if (lf == NULL)
1328 error = ENOENT;
1329 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1330 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1331 lookup.symvalue = (uintptr_t) symval.value;
1332 lookup.symsize = symval.size;
1333 error = copyout(&lookup, uap->data, sizeof(lookup));
1334 } else
1335 error = ENOENT;
1336 } else {
1337 TAILQ_FOREACH(lf, &linker_files, link) {
1338 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1339 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1340 lookup.symvalue = (uintptr_t)symval.value;
1341 lookup.symsize = symval.size;
1342 error = copyout(&lookup, uap->data,
1343 sizeof(lookup));
1344 break;
1345 }
1346 }
1347 if (lf == NULL)
1348 error = ENOENT;
1349 }
1350 sx_xunlock(&kld_sx);
1351 out:
1352 free(symstr, M_TEMP);
1353 return (error);
1354 }
1355
1356 /*
1357 * Preloaded module support
1358 */
1359
1360 static modlist_t
1361 modlist_lookup(const char *name, int ver)
1362 {
1363 modlist_t mod;
1364
1365 TAILQ_FOREACH(mod, &found_modules, link) {
1366 if (strcmp(mod->name, name) == 0 &&
1367 (ver == 0 || mod->version == ver))
1368 return (mod);
1369 }
1370 return (NULL);
1371 }
1372
1373 static modlist_t
1374 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1375 {
1376 modlist_t mod, bestmod;
1377 int ver;
1378
1379 if (verinfo == NULL)
1380 return (modlist_lookup(name, 0));
1381 bestmod = NULL;
1382 TAILQ_FOREACH(mod, &found_modules, link) {
1383 if (strcmp(mod->name, name) != 0)
1384 continue;
1385 ver = mod->version;
1386 if (ver == verinfo->md_ver_preferred)
1387 return (mod);
1388 if (ver >= verinfo->md_ver_minimum &&
1389 ver <= verinfo->md_ver_maximum &&
1390 (bestmod == NULL || ver > bestmod->version))
1391 bestmod = mod;
1392 }
1393 return (bestmod);
1394 }
1395
1396 static modlist_t
1397 modlist_newmodule(const char *modname, int version, linker_file_t container)
1398 {
1399 modlist_t mod;
1400
1401 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1402 if (mod == NULL)
1403 panic("no memory for module list");
1404 mod->container = container;
1405 mod->name = modname;
1406 mod->version = version;
1407 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1408 return (mod);
1409 }
1410
1411 static void
1412 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1413 struct mod_metadata **stop, int preload)
1414 {
1415 struct mod_metadata *mp, **mdp;
1416 const char *modname;
1417 int ver;
1418
1419 for (mdp = start; mdp < stop; mdp++) {
1420 mp = *mdp;
1421 if (mp->md_type != MDT_VERSION)
1422 continue;
1423 modname = mp->md_cval;
1424 ver = ((struct mod_version *)mp->md_data)->mv_version;
1425 if (modlist_lookup(modname, ver) != NULL) {
1426 printf("module %s already present!\n", modname);
1427 /* XXX what can we do? this is a build error. :-( */
1428 continue;
1429 }
1430 modlist_newmodule(modname, ver, lf);
1431 }
1432 }
1433
1434 static void
1435 linker_preload(void *arg)
1436 {
1437 caddr_t modptr;
1438 const char *modname, *nmodname;
1439 char *modtype;
1440 linker_file_t lf, nlf;
1441 linker_class_t lc;
1442 int error;
1443 linker_file_list_t loaded_files;
1444 linker_file_list_t depended_files;
1445 struct mod_metadata *mp, *nmp;
1446 struct mod_metadata **start, **stop, **mdp, **nmdp;
1447 struct mod_depend *verinfo;
1448 int nver;
1449 int resolves;
1450 modlist_t mod;
1451 struct sysinit **si_start, **si_stop;
1452
1453 TAILQ_INIT(&loaded_files);
1454 TAILQ_INIT(&depended_files);
1455 TAILQ_INIT(&found_modules);
1456 error = 0;
1457
1458 modptr = NULL;
1459 sx_xlock(&kld_sx);
1460 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1461 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1462 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1463 if (modname == NULL) {
1464 printf("Preloaded module at %p does not have a"
1465 " name!\n", modptr);
1466 continue;
1467 }
1468 if (modtype == NULL) {
1469 printf("Preloaded module at %p does not have a type!\n",
1470 modptr);
1471 continue;
1472 }
1473 if (bootverbose)
1474 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1475 modptr);
1476 lf = NULL;
1477 TAILQ_FOREACH(lc, &classes, link) {
1478 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1479 if (!error)
1480 break;
1481 lf = NULL;
1482 }
1483 if (lf)
1484 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1485 }
1486
1487 /*
1488 * First get a list of stuff in the kernel.
1489 */
1490 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1491 &stop, NULL) == 0)
1492 linker_addmodules(linker_kernel_file, start, stop, 1);
1493
1494 /*
1495 * This is a once-off kinky bubble sort to resolve relocation
1496 * dependency requirements.
1497 */
1498 restart:
1499 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1500 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1501 &stop, NULL);
1502 /*
1503 * First, look to see if we would successfully link with this
1504 * stuff.
1505 */
1506 resolves = 1; /* unless we know otherwise */
1507 if (!error) {
1508 for (mdp = start; mdp < stop; mdp++) {
1509 mp = *mdp;
1510 if (mp->md_type != MDT_DEPEND)
1511 continue;
1512 modname = mp->md_cval;
1513 verinfo = mp->md_data;
1514 for (nmdp = start; nmdp < stop; nmdp++) {
1515 nmp = *nmdp;
1516 if (nmp->md_type != MDT_VERSION)
1517 continue;
1518 nmodname = nmp->md_cval;
1519 if (strcmp(modname, nmodname) == 0)
1520 break;
1521 }
1522 if (nmdp < stop) /* it's a self reference */
1523 continue;
1524
1525 /*
1526 * ok, the module isn't here yet, we
1527 * are not finished
1528 */
1529 if (modlist_lookup2(modname, verinfo) == NULL)
1530 resolves = 0;
1531 }
1532 }
1533 /*
1534 * OK, if we found our modules, we can link. So, "provide"
1535 * the modules inside and add it to the end of the link order
1536 * list.
1537 */
1538 if (resolves) {
1539 if (!error) {
1540 for (mdp = start; mdp < stop; mdp++) {
1541 mp = *mdp;
1542 if (mp->md_type != MDT_VERSION)
1543 continue;
1544 modname = mp->md_cval;
1545 nver = ((struct mod_version *)
1546 mp->md_data)->mv_version;
1547 if (modlist_lookup(modname,
1548 nver) != NULL) {
1549 printf("module %s already"
1550 " present!\n", modname);
1551 TAILQ_REMOVE(&loaded_files,
1552 lf, loaded);
1553 linker_file_unload(lf,
1554 LINKER_UNLOAD_FORCE);
1555 /* we changed tailq next ptr */
1556 goto restart;
1557 }
1558 modlist_newmodule(modname, nver, lf);
1559 }
1560 }
1561 TAILQ_REMOVE(&loaded_files, lf, loaded);
1562 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1563 /*
1564 * Since we provided modules, we need to restart the
1565 * sort so that the previous files that depend on us
1566 * have a chance. Also, we've busted the tailq next
1567 * pointer with the REMOVE.
1568 */
1569 goto restart;
1570 }
1571 }
1572
1573 /*
1574 * At this point, we check to see what could not be resolved..
1575 */
1576 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1577 TAILQ_REMOVE(&loaded_files, lf, loaded);
1578 printf("KLD file %s is missing dependencies\n", lf->filename);
1579 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1580 }
1581
1582 /*
1583 * We made it. Finish off the linking in the order we determined.
1584 */
1585 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1586 if (linker_kernel_file) {
1587 linker_kernel_file->refs++;
1588 error = linker_file_add_dependency(lf,
1589 linker_kernel_file);
1590 if (error)
1591 panic("cannot add dependency");
1592 }
1593 lf->userrefs++; /* so we can (try to) kldunload it */
1594 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1595 &stop, NULL);
1596 if (!error) {
1597 for (mdp = start; mdp < stop; mdp++) {
1598 mp = *mdp;
1599 if (mp->md_type != MDT_DEPEND)
1600 continue;
1601 modname = mp->md_cval;
1602 verinfo = mp->md_data;
1603 mod = modlist_lookup2(modname, verinfo);
1604 if (mod == NULL) {
1605 printf("KLD file %s - cannot find "
1606 "dependency \"%s\"\n",
1607 lf->filename, modname);
1608 goto fail;
1609 }
1610 /* Don't count self-dependencies */
1611 if (lf == mod->container)
1612 continue;
1613 mod->container->refs++;
1614 error = linker_file_add_dependency(lf,
1615 mod->container);
1616 if (error)
1617 panic("cannot add dependency");
1618 }
1619 }
1620 /*
1621 * Now do relocation etc using the symbol search paths
1622 * established by the dependencies
1623 */
1624 error = LINKER_LINK_PRELOAD_FINISH(lf);
1625 if (error) {
1626 printf("KLD file %s - could not finalize loading\n",
1627 lf->filename);
1628 goto fail;
1629 }
1630 linker_file_register_modules(lf);
1631 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1632 &si_stop, NULL) == 0)
1633 sysinit_add(si_start, si_stop);
1634 linker_file_register_sysctls(lf);
1635 lf->flags |= LINKER_FILE_LINKED;
1636 continue;
1637 fail:
1638 TAILQ_REMOVE(&depended_files, lf, loaded);
1639 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1640 }
1641 sx_xunlock(&kld_sx);
1642 /* woohoo! we made it! */
1643 }
1644
1645 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1646
1647 /*
1648 * Search for a not-loaded module by name.
1649 *
1650 * Modules may be found in the following locations:
1651 *
1652 * - preloaded (result is just the module name) - on disk (result is full path
1653 * to module)
1654 *
1655 * If the module name is qualified in any way (contains path, etc.) the we
1656 * simply return a copy of it.
1657 *
1658 * The search path can be manipulated via sysctl. Note that we use the ';'
1659 * character as a separator to be consistent with the bootloader.
1660 */
1661
1662 static char linker_hintfile[] = "linker.hints";
1663 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1664
1665 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1666 sizeof(linker_path), "module load search path");
1667
1668 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1669
1670 static char *linker_ext_list[] = {
1671 "",
1672 ".ko",
1673 NULL
1674 };
1675
1676 /*
1677 * Check if file actually exists either with or without extension listed in
1678 * the linker_ext_list. (probably should be generic for the rest of the
1679 * kernel)
1680 */
1681 static char *
1682 linker_lookup_file(const char *path, int pathlen, const char *name,
1683 int namelen, struct vattr *vap)
1684 {
1685 struct nameidata nd;
1686 struct thread *td = curthread; /* XXX */
1687 char *result, **cpp, *sep;
1688 int error, len, extlen, reclen, flags;
1689 enum vtype type;
1690
1691 extlen = 0;
1692 for (cpp = linker_ext_list; *cpp; cpp++) {
1693 len = strlen(*cpp);
1694 if (len > extlen)
1695 extlen = len;
1696 }
1697 extlen++; /* trailing '\0' */
1698 sep = (path[pathlen - 1] != '/') ? "/" : "";
1699
1700 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1701 result = malloc(reclen, M_LINKER, M_WAITOK);
1702 for (cpp = linker_ext_list; *cpp; cpp++) {
1703 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1704 namelen, name, *cpp);
1705 /*
1706 * Attempt to open the file, and return the path if
1707 * we succeed and it's a regular file.
1708 */
1709 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1710 flags = FREAD;
1711 error = vn_open(&nd, &flags, 0, NULL);
1712 if (error == 0) {
1713 NDFREE(&nd, NDF_ONLY_PNBUF);
1714 type = nd.ni_vp->v_type;
1715 if (vap)
1716 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1717 VOP_UNLOCK(nd.ni_vp, 0);
1718 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1719 if (type == VREG)
1720 return (result);
1721 }
1722 }
1723 free(result, M_LINKER);
1724 return (NULL);
1725 }
1726
1727 #define INT_ALIGN(base, ptr) ptr = \
1728 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1729
1730 /*
1731 * Lookup KLD which contains requested module in the "linker.hints" file. If
1732 * version specification is available, then try to find the best KLD.
1733 * Otherwise just find the latest one.
1734 */
1735 static char *
1736 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1737 int modnamelen, struct mod_depend *verinfo)
1738 {
1739 struct thread *td = curthread; /* XXX */
1740 struct ucred *cred = td ? td->td_ucred : NULL;
1741 struct nameidata nd;
1742 struct vattr vattr, mattr;
1743 u_char *hints = NULL;
1744 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1745 int error, ival, bestver, *intp, found, flags, clen, blen;
1746 ssize_t reclen;
1747
1748 result = NULL;
1749 bestver = found = 0;
1750
1751 sep = (path[pathlen - 1] != '/') ? "/" : "";
1752 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1753 strlen(sep) + 1;
1754 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1755 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1756 linker_hintfile);
1757
1758 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1759 flags = FREAD;
1760 error = vn_open(&nd, &flags, 0, NULL);
1761 if (error)
1762 goto bad;
1763 NDFREE(&nd, NDF_ONLY_PNBUF);
1764 if (nd.ni_vp->v_type != VREG)
1765 goto bad;
1766 best = cp = NULL;
1767 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1768 if (error)
1769 goto bad;
1770 /*
1771 * XXX: we need to limit this number to some reasonable value
1772 */
1773 if (vattr.va_size > 100 * 1024) {
1774 printf("hints file too large %ld\n", (long)vattr.va_size);
1775 goto bad;
1776 }
1777 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1778 if (hints == NULL)
1779 goto bad;
1780 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1781 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1782 if (error)
1783 goto bad;
1784 VOP_UNLOCK(nd.ni_vp, 0);
1785 vn_close(nd.ni_vp, FREAD, cred, td);
1786 nd.ni_vp = NULL;
1787 if (reclen != 0) {
1788 printf("can't read %zd\n", reclen);
1789 goto bad;
1790 }
1791 intp = (int *)hints;
1792 ival = *intp++;
1793 if (ival != LINKER_HINTS_VERSION) {
1794 printf("hints file version mismatch %d\n", ival);
1795 goto bad;
1796 }
1797 bufend = hints + vattr.va_size;
1798 recptr = (u_char *)intp;
1799 clen = blen = 0;
1800 while (recptr < bufend && !found) {
1801 intp = (int *)recptr;
1802 reclen = *intp++;
1803 ival = *intp++;
1804 cp = (char *)intp;
1805 switch (ival) {
1806 case MDT_VERSION:
1807 clen = *cp++;
1808 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1809 break;
1810 cp += clen;
1811 INT_ALIGN(hints, cp);
1812 ival = *(int *)cp;
1813 cp += sizeof(int);
1814 clen = *cp++;
1815 if (verinfo == NULL ||
1816 ival == verinfo->md_ver_preferred) {
1817 found = 1;
1818 break;
1819 }
1820 if (ival >= verinfo->md_ver_minimum &&
1821 ival <= verinfo->md_ver_maximum &&
1822 ival > bestver) {
1823 bestver = ival;
1824 best = cp;
1825 blen = clen;
1826 }
1827 break;
1828 default:
1829 break;
1830 }
1831 recptr += reclen + sizeof(int);
1832 }
1833 /*
1834 * Finally check if KLD is in the place
1835 */
1836 if (found)
1837 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1838 else if (best)
1839 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1840
1841 /*
1842 * KLD is newer than hints file. What we should do now?
1843 */
1844 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1845 printf("warning: KLD '%s' is newer than the linker.hints"
1846 " file\n", result);
1847 bad:
1848 free(pathbuf, M_LINKER);
1849 if (hints)
1850 free(hints, M_TEMP);
1851 if (nd.ni_vp != NULL) {
1852 VOP_UNLOCK(nd.ni_vp, 0);
1853 vn_close(nd.ni_vp, FREAD, cred, td);
1854 }
1855 /*
1856 * If nothing found or hints is absent - fallback to the old
1857 * way by using "kldname[.ko]" as module name.
1858 */
1859 if (!found && !bestver && result == NULL)
1860 result = linker_lookup_file(path, pathlen, modname,
1861 modnamelen, NULL);
1862 return (result);
1863 }
1864
1865 /*
1866 * Lookup KLD which contains requested module in the all directories.
1867 */
1868 static char *
1869 linker_search_module(const char *modname, int modnamelen,
1870 struct mod_depend *verinfo)
1871 {
1872 char *cp, *ep, *result;
1873
1874 /*
1875 * traverse the linker path
1876 */
1877 for (cp = linker_path; *cp; cp = ep + 1) {
1878 /* find the end of this component */
1879 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1880 result = linker_hints_lookup(cp, ep - cp, modname,
1881 modnamelen, verinfo);
1882 if (result != NULL)
1883 return (result);
1884 if (*ep == 0)
1885 break;
1886 }
1887 return (NULL);
1888 }
1889
1890 /*
1891 * Search for module in all directories listed in the linker_path.
1892 */
1893 static char *
1894 linker_search_kld(const char *name)
1895 {
1896 char *cp, *ep, *result;
1897 int len;
1898
1899 /* qualified at all? */
1900 if (strchr(name, '/'))
1901 return (strdup(name, M_LINKER));
1902
1903 /* traverse the linker path */
1904 len = strlen(name);
1905 for (ep = linker_path; *ep; ep++) {
1906 cp = ep;
1907 /* find the end of this component */
1908 for (; *ep != 0 && *ep != ';'; ep++);
1909 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1910 if (result != NULL)
1911 return (result);
1912 }
1913 return (NULL);
1914 }
1915
1916 static const char *
1917 linker_basename(const char *path)
1918 {
1919 const char *filename;
1920
1921 filename = strrchr(path, '/');
1922 if (filename == NULL)
1923 return path;
1924 if (filename[1])
1925 filename++;
1926 return (filename);
1927 }
1928
1929 #ifdef HWPMC_HOOKS
1930 /*
1931 * Inform hwpmc about the set of kernel modules currently loaded.
1932 */
1933 void *
1934 linker_hwpmc_list_objects(void)
1935 {
1936 linker_file_t lf;
1937 struct pmckern_map_in *kobase;
1938 int i, nmappings;
1939
1940 nmappings = 0;
1941 sx_slock(&kld_sx);
1942 TAILQ_FOREACH(lf, &linker_files, link)
1943 nmappings++;
1944
1945 /* Allocate nmappings + 1 entries. */
1946 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1947 M_LINKER, M_WAITOK | M_ZERO);
1948 i = 0;
1949 TAILQ_FOREACH(lf, &linker_files, link) {
1950
1951 /* Save the info for this linker file. */
1952 kobase[i].pm_file = lf->filename;
1953 kobase[i].pm_address = (uintptr_t)lf->address;
1954 i++;
1955 }
1956 sx_sunlock(&kld_sx);
1957
1958 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1959
1960 /* The last entry of the malloced area comprises of all zeros. */
1961 KASSERT(kobase[i].pm_file == NULL,
1962 ("linker_hwpmc_list_objects: last object not NULL"));
1963
1964 return ((void *)kobase);
1965 }
1966 #endif
1967
1968 /*
1969 * Find a file which contains given module and load it, if "parent" is not
1970 * NULL, register a reference to it.
1971 */
1972 static int
1973 linker_load_module(const char *kldname, const char *modname,
1974 struct linker_file *parent, struct mod_depend *verinfo,
1975 struct linker_file **lfpp)
1976 {
1977 linker_file_t lfdep;
1978 const char *filename;
1979 char *pathname;
1980 int error;
1981
1982 sx_assert(&kld_sx, SA_XLOCKED);
1983 if (modname == NULL) {
1984 /*
1985 * We have to load KLD
1986 */
1987 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1988 " is not NULL"));
1989 pathname = linker_search_kld(kldname);
1990 } else {
1991 if (modlist_lookup2(modname, verinfo) != NULL)
1992 return (EEXIST);
1993 if (kldname != NULL)
1994 pathname = strdup(kldname, M_LINKER);
1995 else if (rootvnode == NULL)
1996 pathname = NULL;
1997 else
1998 /*
1999 * Need to find a KLD with required module
2000 */
2001 pathname = linker_search_module(modname,
2002 strlen(modname), verinfo);
2003 }
2004 if (pathname == NULL)
2005 return (ENOENT);
2006
2007 /*
2008 * Can't load more than one file with the same basename XXX:
2009 * Actually it should be possible to have multiple KLDs with
2010 * the same basename but different path because they can
2011 * provide different versions of the same modules.
2012 */
2013 filename = linker_basename(pathname);
2014 if (linker_find_file_by_name(filename))
2015 error = EEXIST;
2016 else do {
2017 error = linker_load_file(pathname, &lfdep);
2018 if (error)
2019 break;
2020 if (modname && verinfo &&
2021 modlist_lookup2(modname, verinfo) == NULL) {
2022 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2023 error = ENOENT;
2024 break;
2025 }
2026 if (parent) {
2027 error = linker_file_add_dependency(parent, lfdep);
2028 if (error)
2029 break;
2030 }
2031 if (lfpp)
2032 *lfpp = lfdep;
2033 } while (0);
2034 free(pathname, M_LINKER);
2035 return (error);
2036 }
2037
2038 /*
2039 * This routine is responsible for finding dependencies of userland initiated
2040 * kldload(2)'s of files.
2041 */
2042 int
2043 linker_load_dependencies(linker_file_t lf)
2044 {
2045 linker_file_t lfdep;
2046 struct mod_metadata **start, **stop, **mdp, **nmdp;
2047 struct mod_metadata *mp, *nmp;
2048 struct mod_depend *verinfo;
2049 modlist_t mod;
2050 const char *modname, *nmodname;
2051 int ver, error = 0, count;
2052
2053 /*
2054 * All files are dependant on /kernel.
2055 */
2056 sx_assert(&kld_sx, SA_XLOCKED);
2057 if (linker_kernel_file) {
2058 linker_kernel_file->refs++;
2059 error = linker_file_add_dependency(lf, linker_kernel_file);
2060 if (error)
2061 return (error);
2062 }
2063 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2064 &count) != 0)
2065 return (0);
2066 for (mdp = start; mdp < stop; mdp++) {
2067 mp = *mdp;
2068 if (mp->md_type != MDT_VERSION)
2069 continue;
2070 modname = mp->md_cval;
2071 ver = ((struct mod_version *)mp->md_data)->mv_version;
2072 mod = modlist_lookup(modname, ver);
2073 if (mod != NULL) {
2074 printf("interface %s.%d already present in the KLD"
2075 " '%s'!\n", modname, ver,
2076 mod->container->filename);
2077 return (EEXIST);
2078 }
2079 }
2080
2081 for (mdp = start; mdp < stop; mdp++) {
2082 mp = *mdp;
2083 if (mp->md_type != MDT_DEPEND)
2084 continue;
2085 modname = mp->md_cval;
2086 verinfo = mp->md_data;
2087 nmodname = NULL;
2088 for (nmdp = start; nmdp < stop; nmdp++) {
2089 nmp = *nmdp;
2090 if (nmp->md_type != MDT_VERSION)
2091 continue;
2092 nmodname = nmp->md_cval;
2093 if (strcmp(modname, nmodname) == 0)
2094 break;
2095 }
2096 if (nmdp < stop)/* early exit, it's a self reference */
2097 continue;
2098 mod = modlist_lookup2(modname, verinfo);
2099 if (mod) { /* woohoo, it's loaded already */
2100 lfdep = mod->container;
2101 lfdep->refs++;
2102 error = linker_file_add_dependency(lf, lfdep);
2103 if (error)
2104 break;
2105 continue;
2106 }
2107 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2108 if (error) {
2109 printf("KLD %s: depends on %s - not available or"
2110 " version mismatch\n", lf->filename, modname);
2111 break;
2112 }
2113 }
2114
2115 if (error)
2116 return (error);
2117 linker_addmodules(lf, start, stop, 0);
2118 return (error);
2119 }
2120
2121 static int
2122 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2123 {
2124 struct sysctl_req *req;
2125
2126 req = opaque;
2127 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2128 }
2129
2130 /*
2131 * Export a nul-separated, double-nul-terminated list of all function names
2132 * in the kernel.
2133 */
2134 static int
2135 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2136 {
2137 linker_file_t lf;
2138 int error;
2139
2140 #ifdef MAC
2141 error = mac_kld_check_stat(req->td->td_ucred);
2142 if (error)
2143 return (error);
2144 #endif
2145 error = sysctl_wire_old_buffer(req, 0);
2146 if (error != 0)
2147 return (error);
2148 sx_xlock(&kld_sx);
2149 TAILQ_FOREACH(lf, &linker_files, link) {
2150 error = LINKER_EACH_FUNCTION_NAME(lf,
2151 sysctl_kern_function_list_iterate, req);
2152 if (error) {
2153 sx_xunlock(&kld_sx);
2154 return (error);
2155 }
2156 }
2157 sx_xunlock(&kld_sx);
2158 return (SYSCTL_OUT(req, "", 1));
2159 }
2160
2161 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2162 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: 933ccded1002539ea9ebdf2a47709fb1
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