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/8.2/sys/kern/kern_linker.c 213553 2010-10-08 07:49:05Z avg $");
29
30 #include "opt_ddb.h"
31 #include "opt_hwpmc_hooks.h"
32
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/sysproto.h>
38 #include <sys/sysent.h>
39 #include <sys/priv.h>
40 #include <sys/proc.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/sx.h>
44 #include <sys/module.h>
45 #include <sys/mount.h>
46 #include <sys/linker.h>
47 #include <sys/fcntl.h>
48 #include <sys/jail.h>
49 #include <sys/libkern.h>
50 #include <sys/namei.h>
51 #include <sys/vnode.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysctl.h>
54
55 #include <net/vnet.h>
56
57 #include <security/mac/mac_framework.h>
58
59 #include "linker_if.h"
60
61 #ifdef HWPMC_HOOKS
62 #include <sys/pmckern.h>
63 #endif
64
65 #ifdef KLD_DEBUG
66 int kld_debug = 0;
67 #endif
68
69 #define KLD_LOCK() sx_xlock(&kld_sx)
70 #define KLD_UNLOCK() sx_xunlock(&kld_sx)
71 #define KLD_LOCKED() sx_xlocked(&kld_sx)
72 #define KLD_LOCK_ASSERT() do { \
73 if (!cold) \
74 sx_assert(&kld_sx, SX_XLOCKED); \
75 } while (0)
76
77 /*
78 * static char *linker_search_path(const char *name, struct mod_depend
79 * *verinfo);
80 */
81 static const char *linker_basename(const char *path);
82
83 /*
84 * Find a currently loaded file given its filename.
85 */
86 static linker_file_t linker_find_file_by_name(const char* _filename);
87
88 /*
89 * Find a currently loaded file given its file id.
90 */
91 static linker_file_t linker_find_file_by_id(int _fileid);
92
93 /* Metadata from the static kernel */
94 SET_DECLARE(modmetadata_set, struct mod_metadata);
95
96 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
97
98 linker_file_t linker_kernel_file;
99
100 static struct sx kld_sx; /* kernel linker lock */
101
102 /*
103 * Load counter used by clients to determine if a linker file has been
104 * re-loaded. This counter is incremented for each file load.
105 */
106 static int loadcnt;
107
108 static linker_class_list_t classes;
109 static linker_file_list_t linker_files;
110 static int next_file_id = 1;
111 static int linker_no_more_classes = 0;
112
113 #define LINKER_GET_NEXT_FILE_ID(a) do { \
114 linker_file_t lftmp; \
115 \
116 KLD_LOCK_ASSERT(); \
117 retry: \
118 TAILQ_FOREACH(lftmp, &linker_files, link) { \
119 if (next_file_id == lftmp->id) { \
120 next_file_id++; \
121 goto retry; \
122 } \
123 } \
124 (a) = next_file_id; \
125 } while(0)
126
127
128 /* XXX wrong name; we're looking at version provision tags here, not modules */
129 typedef TAILQ_HEAD(, modlist) modlisthead_t;
130 struct modlist {
131 TAILQ_ENTRY(modlist) link; /* chain together all modules */
132 linker_file_t container;
133 const char *name;
134 int version;
135 };
136 typedef struct modlist *modlist_t;
137 static modlisthead_t found_modules;
138
139 static int linker_file_add_dependency(linker_file_t file,
140 linker_file_t dep);
141 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
142 const char* name, int deps);
143 static int linker_load_module(const char *kldname,
144 const char *modname, struct linker_file *parent,
145 struct mod_depend *verinfo, struct linker_file **lfpp);
146 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
147
148 static char *
149 linker_strdup(const char *str)
150 {
151 char *result;
152
153 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
154 strcpy(result, str);
155 return (result);
156 }
157
158 static void
159 linker_init(void *arg)
160 {
161
162 sx_init(&kld_sx, "kernel linker");
163 TAILQ_INIT(&classes);
164 TAILQ_INIT(&linker_files);
165 }
166
167 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
168
169 static void
170 linker_stop_class_add(void *arg)
171 {
172
173 linker_no_more_classes = 1;
174 }
175
176 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
177
178 int
179 linker_add_class(linker_class_t lc)
180 {
181
182 /*
183 * We disallow any class registration past SI_ORDER_ANY
184 * of SI_SUB_KLD. We bump the reference count to keep the
185 * ops from being freed.
186 */
187 if (linker_no_more_classes == 1)
188 return (EPERM);
189 kobj_class_compile((kobj_class_t) lc);
190 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */
191 TAILQ_INSERT_TAIL(&classes, lc, link);
192 return (0);
193 }
194
195 static void
196 linker_file_sysinit(linker_file_t lf)
197 {
198 struct sysinit **start, **stop, **sipp, **xipp, *save;
199
200 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
201 lf->filename));
202
203 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
204 return;
205 /*
206 * Perform a bubble sort of the system initialization objects by
207 * their subsystem (primary key) and order (secondary key).
208 *
209 * Since some things care about execution order, this is the operation
210 * which ensures continued function.
211 */
212 for (sipp = start; sipp < stop; sipp++) {
213 for (xipp = sipp + 1; xipp < stop; xipp++) {
214 if ((*sipp)->subsystem < (*xipp)->subsystem ||
215 ((*sipp)->subsystem == (*xipp)->subsystem &&
216 (*sipp)->order <= (*xipp)->order))
217 continue; /* skip */
218 save = *sipp;
219 *sipp = *xipp;
220 *xipp = save;
221 }
222 }
223
224 /*
225 * Traverse the (now) ordered list of system initialization tasks.
226 * Perform each task, and continue on to the next task.
227 */
228 mtx_lock(&Giant);
229 for (sipp = start; sipp < stop; sipp++) {
230 if ((*sipp)->subsystem == SI_SUB_DUMMY)
231 continue; /* skip dummy task(s) */
232
233 /* Call function */
234 (*((*sipp)->func)) ((*sipp)->udata);
235 }
236 mtx_unlock(&Giant);
237 }
238
239 static void
240 linker_file_sysuninit(linker_file_t lf)
241 {
242 struct sysinit **start, **stop, **sipp, **xipp, *save;
243
244 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
245 lf->filename));
246
247 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
248 NULL) != 0)
249 return;
250
251 /*
252 * Perform a reverse bubble sort of the system initialization objects
253 * by their subsystem (primary key) and order (secondary key).
254 *
255 * Since some things care about execution order, this is the operation
256 * which ensures continued function.
257 */
258 for (sipp = start; sipp < stop; sipp++) {
259 for (xipp = sipp + 1; xipp < stop; xipp++) {
260 if ((*sipp)->subsystem > (*xipp)->subsystem ||
261 ((*sipp)->subsystem == (*xipp)->subsystem &&
262 (*sipp)->order >= (*xipp)->order))
263 continue; /* skip */
264 save = *sipp;
265 *sipp = *xipp;
266 *xipp = save;
267 }
268 }
269
270 /*
271 * Traverse the (now) ordered list of system initialization tasks.
272 * Perform each task, and continue on to the next task.
273 */
274 mtx_lock(&Giant);
275 for (sipp = start; sipp < stop; sipp++) {
276 if ((*sipp)->subsystem == SI_SUB_DUMMY)
277 continue; /* skip dummy task(s) */
278
279 /* Call function */
280 (*((*sipp)->func)) ((*sipp)->udata);
281 }
282 mtx_unlock(&Giant);
283 }
284
285 static void
286 linker_file_register_sysctls(linker_file_t lf)
287 {
288 struct sysctl_oid **start, **stop, **oidp;
289
290 KLD_DPF(FILE,
291 ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
292 lf->filename));
293
294 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
295 return;
296
297 sysctl_lock();
298 for (oidp = start; oidp < stop; oidp++)
299 sysctl_register_oid(*oidp);
300 sysctl_unlock();
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: registering SYSCTLs"
309 " for %s\n", lf->filename));
310
311 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
312 return;
313
314 sysctl_lock();
315 for (oidp = start; oidp < stop; oidp++)
316 sysctl_unregister_oid(*oidp);
317 sysctl_unlock();
318 }
319
320 static int
321 linker_file_register_modules(linker_file_t lf)
322 {
323 struct mod_metadata **start, **stop, **mdp;
324 const moduledata_t *moddata;
325 int first_error, error;
326
327 KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
328 " in %s\n", lf->filename));
329
330 if (linker_file_lookup_set(lf, "modmetadata_set", &start,
331 &stop, NULL) != 0) {
332 /*
333 * This fallback should be unnecessary, but if we get booted
334 * from boot2 instead of loader and we are missing our
335 * metadata then we have to try the best we can.
336 */
337 if (lf == linker_kernel_file) {
338 start = SET_BEGIN(modmetadata_set);
339 stop = SET_LIMIT(modmetadata_set);
340 } else
341 return (0);
342 }
343 first_error = 0;
344 for (mdp = start; mdp < stop; mdp++) {
345 if ((*mdp)->md_type != MDT_MODULE)
346 continue;
347 moddata = (*mdp)->md_data;
348 KLD_DPF(FILE, ("Registering module %s in %s\n",
349 moddata->name, lf->filename));
350 error = module_register(moddata, lf);
351 if (error) {
352 printf("Module %s failed to register: %d\n",
353 moddata->name, error);
354 if (first_error == 0)
355 first_error = error;
356 }
357 }
358 return (first_error);
359 }
360
361 static void
362 linker_init_kernel_modules(void)
363 {
364
365 linker_file_register_modules(linker_kernel_file);
366 }
367
368 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
369 0);
370
371 static int
372 linker_load_file(const char *filename, linker_file_t *result)
373 {
374 linker_class_t lc;
375 linker_file_t lf;
376 int foundfile, error;
377
378 /* Refuse to load modules if securelevel raised */
379 if (prison0.pr_securelevel > 0)
380 return (EPERM);
381
382 KLD_LOCK_ASSERT();
383 lf = linker_find_file_by_name(filename);
384 if (lf) {
385 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
386 " incrementing refs\n", filename));
387 *result = lf;
388 lf->refs++;
389 return (0);
390 }
391 foundfile = 0;
392 error = 0;
393
394 /*
395 * We do not need to protect (lock) classes here because there is
396 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
397 * and there is no class deregistration mechanism at this time.
398 */
399 TAILQ_FOREACH(lc, &classes, link) {
400 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
401 filename));
402 error = LINKER_LOAD_FILE(lc, filename, &lf);
403 /*
404 * If we got something other than ENOENT, then it exists but
405 * we cannot load it for some other reason.
406 */
407 if (error != ENOENT)
408 foundfile = 1;
409 if (lf) {
410 error = linker_file_register_modules(lf);
411 if (error == EEXIST) {
412 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
413 return (error);
414 }
415 KLD_UNLOCK();
416 linker_file_register_sysctls(lf);
417 linker_file_sysinit(lf);
418 KLD_LOCK();
419 lf->flags |= LINKER_FILE_LINKED;
420 *result = lf;
421 return (0);
422 }
423 }
424 /*
425 * Less than ideal, but tells the user whether it failed to load or
426 * the module was not found.
427 */
428 if (foundfile) {
429
430 /*
431 * If the file type has not been recognized by the last try
432 * printout a message before to fail.
433 */
434 if (error == ENOSYS)
435 printf("linker_load_file: Unsupported file type\n");
436
437 /*
438 * Format not recognized or otherwise unloadable.
439 * When loading a module that is statically built into
440 * the kernel EEXIST percolates back up as the return
441 * value. Preserve this so that apps like sysinstall
442 * can recognize this special case and not post bogus
443 * dialog boxes.
444 */
445 if (error != EEXIST)
446 error = ENOEXEC;
447 } else
448 error = ENOENT; /* Nothing found */
449 return (error);
450 }
451
452 int
453 linker_reference_module(const char *modname, struct mod_depend *verinfo,
454 linker_file_t *result)
455 {
456 modlist_t mod;
457 int error;
458
459 KLD_LOCK();
460 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
461 *result = mod->container;
462 (*result)->refs++;
463 KLD_UNLOCK();
464 return (0);
465 }
466
467 error = linker_load_module(NULL, modname, NULL, verinfo, result);
468 KLD_UNLOCK();
469 return (error);
470 }
471
472 int
473 linker_release_module(const char *modname, struct mod_depend *verinfo,
474 linker_file_t lf)
475 {
476 modlist_t mod;
477 int error;
478
479 KLD_LOCK();
480 if (lf == NULL) {
481 KASSERT(modname != NULL,
482 ("linker_release_module: no file or name"));
483 mod = modlist_lookup2(modname, verinfo);
484 if (mod == NULL) {
485 KLD_UNLOCK();
486 return (ESRCH);
487 }
488 lf = mod->container;
489 } else
490 KASSERT(modname == NULL && verinfo == NULL,
491 ("linker_release_module: both file and name"));
492 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
493 KLD_UNLOCK();
494 return (error);
495 }
496
497 static linker_file_t
498 linker_find_file_by_name(const char *filename)
499 {
500 linker_file_t lf;
501 char *koname;
502
503 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
504 sprintf(koname, "%s.ko", filename);
505
506 KLD_LOCK_ASSERT();
507 TAILQ_FOREACH(lf, &linker_files, link) {
508 if (strcmp(lf->filename, koname) == 0)
509 break;
510 if (strcmp(lf->filename, filename) == 0)
511 break;
512 }
513 free(koname, M_LINKER);
514 return (lf);
515 }
516
517 static linker_file_t
518 linker_find_file_by_id(int fileid)
519 {
520 linker_file_t lf;
521
522 KLD_LOCK_ASSERT();
523 TAILQ_FOREACH(lf, &linker_files, link)
524 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
525 break;
526 return (lf);
527 }
528
529 int
530 linker_file_foreach(linker_predicate_t *predicate, void *context)
531 {
532 linker_file_t lf;
533 int retval = 0;
534
535 KLD_LOCK();
536 TAILQ_FOREACH(lf, &linker_files, link) {
537 retval = predicate(lf, context);
538 if (retval != 0)
539 break;
540 }
541 KLD_UNLOCK();
542 return (retval);
543 }
544
545 linker_file_t
546 linker_make_file(const char *pathname, linker_class_t lc)
547 {
548 linker_file_t lf;
549 const char *filename;
550
551 KLD_LOCK_ASSERT();
552 filename = linker_basename(pathname);
553
554 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
555 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
556 if (lf == NULL)
557 return (NULL);
558 lf->refs = 1;
559 lf->userrefs = 0;
560 lf->flags = 0;
561 lf->filename = linker_strdup(filename);
562 lf->pathname = linker_strdup(pathname);
563 LINKER_GET_NEXT_FILE_ID(lf->id);
564 lf->ndeps = 0;
565 lf->deps = NULL;
566 lf->loadcnt = ++loadcnt;
567 lf->sdt_probes = NULL;
568 lf->sdt_nprobes = 0;
569 STAILQ_INIT(&lf->common);
570 TAILQ_INIT(&lf->modules);
571 TAILQ_INSERT_TAIL(&linker_files, lf, link);
572 return (lf);
573 }
574
575 int
576 linker_file_unload(linker_file_t file, int flags)
577 {
578 module_t mod, next;
579 modlist_t ml, nextml;
580 struct common_symbol *cp;
581 int error, i;
582
583 /* Refuse to unload modules if securelevel raised. */
584 if (prison0.pr_securelevel > 0)
585 return (EPERM);
586
587 KLD_LOCK_ASSERT();
588 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
589
590 /* Easy case of just dropping a reference. */
591 if (file->refs > 1) {
592 file->refs--;
593 return (0);
594 }
595
596 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
597 " informing modules\n"));
598
599 /*
600 * Quiesce all the modules to give them a chance to veto the unload.
601 */
602 MOD_SLOCK;
603 for (mod = TAILQ_FIRST(&file->modules); mod;
604 mod = module_getfnext(mod)) {
605
606 error = module_quiesce(mod);
607 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
608 KLD_DPF(FILE, ("linker_file_unload: module %s"
609 " vetoed unload\n", module_getname(mod)));
610 /*
611 * XXX: Do we need to tell all the quiesced modules
612 * that they can resume work now via a new module
613 * event?
614 */
615 MOD_SUNLOCK;
616 return (error);
617 }
618 }
619 MOD_SUNLOCK;
620
621 /*
622 * Inform any modules associated with this file that they are
623 * being be unloaded.
624 */
625 MOD_XLOCK;
626 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
627 next = module_getfnext(mod);
628 MOD_XUNLOCK;
629
630 /*
631 * Give the module a chance to veto the unload.
632 */
633 if ((error = module_unload(mod)) != 0) {
634 KLD_DPF(FILE, ("linker_file_unload: module %s"
635 " failed unload\n", mod));
636 return (error);
637 }
638 MOD_XLOCK;
639 module_release(mod);
640 }
641 MOD_XUNLOCK;
642
643 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
644 if (ml->container == file) {
645 TAILQ_REMOVE(&found_modules, ml, link);
646 free(ml, M_LINKER);
647 }
648 }
649
650 /*
651 * Don't try to run SYSUNINITs if we are unloaded due to a
652 * link error.
653 */
654 if (file->flags & LINKER_FILE_LINKED) {
655 file->flags &= ~LINKER_FILE_LINKED;
656 KLD_UNLOCK();
657 linker_file_sysuninit(file);
658 linker_file_unregister_sysctls(file);
659 KLD_LOCK();
660 }
661 TAILQ_REMOVE(&linker_files, file, link);
662
663 if (file->deps) {
664 for (i = 0; i < file->ndeps; i++)
665 linker_file_unload(file->deps[i], flags);
666 free(file->deps, M_LINKER);
667 file->deps = NULL;
668 }
669 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
670 STAILQ_REMOVE_HEAD(&file->common, link);
671 free(cp, M_LINKER);
672 }
673
674 LINKER_UNLOAD(file);
675 if (file->filename) {
676 free(file->filename, M_LINKER);
677 file->filename = NULL;
678 }
679 if (file->pathname) {
680 free(file->pathname, M_LINKER);
681 file->pathname = NULL;
682 }
683 kobj_delete((kobj_t) file, M_LINKER);
684 return (0);
685 }
686
687 int
688 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
689 {
690 return (LINKER_CTF_GET(file, lc));
691 }
692
693 static int
694 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
695 {
696 linker_file_t *newdeps;
697
698 KLD_LOCK_ASSERT();
699 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
700 M_LINKER, M_WAITOK | M_ZERO);
701 if (newdeps == NULL)
702 return (ENOMEM);
703
704 if (file->deps) {
705 bcopy(file->deps, newdeps,
706 file->ndeps * sizeof(linker_file_t *));
707 free(file->deps, M_LINKER);
708 }
709 file->deps = newdeps;
710 file->deps[file->ndeps] = dep;
711 file->ndeps++;
712 return (0);
713 }
714
715 /*
716 * Locate a linker set and its contents. This is a helper function to avoid
717 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
718 * This function is used in this file so we can avoid having lots of (void **)
719 * casts.
720 */
721 int
722 linker_file_lookup_set(linker_file_t file, const char *name,
723 void *firstp, void *lastp, int *countp)
724 {
725 int error, locked;
726
727 locked = KLD_LOCKED();
728 if (!locked)
729 KLD_LOCK();
730 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
731 if (!locked)
732 KLD_UNLOCK();
733 return (error);
734 }
735
736 /*
737 * List all functions in a file.
738 */
739 int
740 linker_file_function_listall(linker_file_t lf,
741 linker_function_nameval_callback_t callback_func, void *arg)
742 {
743 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
744 }
745
746 caddr_t
747 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
748 {
749 caddr_t sym;
750 int locked;
751
752 locked = KLD_LOCKED();
753 if (!locked)
754 KLD_LOCK();
755 sym = linker_file_lookup_symbol_internal(file, name, deps);
756 if (!locked)
757 KLD_UNLOCK();
758 return (sym);
759 }
760
761 static caddr_t
762 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
763 int deps)
764 {
765 c_linker_sym_t sym;
766 linker_symval_t symval;
767 caddr_t address;
768 size_t common_size = 0;
769 int i;
770
771 KLD_LOCK_ASSERT();
772 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
773 file, name, deps));
774
775 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
776 LINKER_SYMBOL_VALUES(file, sym, &symval);
777 if (symval.value == 0)
778 /*
779 * For commons, first look them up in the
780 * dependencies and only allocate space if not found
781 * there.
782 */
783 common_size = symval.size;
784 else {
785 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
786 ".value=%p\n", symval.value));
787 return (symval.value);
788 }
789 }
790 if (deps) {
791 for (i = 0; i < file->ndeps; i++) {
792 address = linker_file_lookup_symbol_internal(
793 file->deps[i], name, 0);
794 if (address) {
795 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
796 " deps value=%p\n", address));
797 return (address);
798 }
799 }
800 }
801 if (common_size > 0) {
802 /*
803 * This is a common symbol which was not found in the
804 * dependencies. We maintain a simple common symbol table in
805 * the file object.
806 */
807 struct common_symbol *cp;
808
809 STAILQ_FOREACH(cp, &file->common, link) {
810 if (strcmp(cp->name, name) == 0) {
811 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
812 " old common value=%p\n", cp->address));
813 return (cp->address);
814 }
815 }
816 /*
817 * Round the symbol size up to align.
818 */
819 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
820 cp = malloc(sizeof(struct common_symbol)
821 + common_size + strlen(name) + 1, M_LINKER,
822 M_WAITOK | M_ZERO);
823 cp->address = (caddr_t)(cp + 1);
824 cp->name = cp->address + common_size;
825 strcpy(cp->name, name);
826 bzero(cp->address, common_size);
827 STAILQ_INSERT_TAIL(&file->common, cp, link);
828
829 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
830 " value=%p\n", cp->address));
831 return (cp->address);
832 }
833 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
834 return (0);
835 }
836
837 /*
838 * Both DDB and stack(9) rely on the kernel linker to provide forward and
839 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
840 * do this in a lockfree manner. We provide a set of internal helper
841 * routines to perform these operations without locks, and then wrappers that
842 * optionally lock.
843 *
844 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
845 */
846 #ifdef DDB
847 static int
848 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
849 {
850 linker_file_t lf;
851
852 TAILQ_FOREACH(lf, &linker_files, link) {
853 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
854 return (0);
855 }
856 return (ENOENT);
857 }
858 #endif
859
860 static int
861 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
862 {
863 linker_file_t lf;
864 c_linker_sym_t best, es;
865 u_long diff, bestdiff, off;
866
867 best = 0;
868 off = (uintptr_t)value;
869 bestdiff = off;
870 TAILQ_FOREACH(lf, &linker_files, link) {
871 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
872 continue;
873 if (es != 0 && diff < bestdiff) {
874 best = es;
875 bestdiff = diff;
876 }
877 if (bestdiff == 0)
878 break;
879 }
880 if (best) {
881 *sym = best;
882 *diffp = bestdiff;
883 return (0);
884 } else {
885 *sym = 0;
886 *diffp = off;
887 return (ENOENT);
888 }
889 }
890
891 static int
892 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
893 {
894 linker_file_t lf;
895
896 TAILQ_FOREACH(lf, &linker_files, link) {
897 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
898 return (0);
899 }
900 return (ENOENT);
901 }
902
903 static int
904 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
905 long *offset)
906 {
907 linker_symval_t symval;
908 c_linker_sym_t sym;
909 int error;
910
911 *offset = 0;
912 error = linker_debug_search_symbol(value, &sym, offset);
913 if (error)
914 return (error);
915 error = linker_debug_symbol_values(sym, &symval);
916 if (error)
917 return (error);
918 strlcpy(buf, symval.name, buflen);
919 return (0);
920 }
921
922 /*
923 * DDB Helpers. DDB has to look across multiple files with their own symbol
924 * tables and string tables.
925 *
926 * Note that we do not obey list locking protocols here. We really don't need
927 * DDB to hang because somebody's got the lock held. We'll take the chance
928 * that the files list is inconsistant instead.
929 */
930 #ifdef DDB
931 int
932 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
933 {
934
935 return (linker_debug_lookup(symstr, sym));
936 }
937 #endif
938
939 int
940 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
941 {
942
943 return (linker_debug_search_symbol(value, sym, diffp));
944 }
945
946 int
947 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
948 {
949
950 return (linker_debug_symbol_values(sym, symval));
951 }
952
953 int
954 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
955 long *offset)
956 {
957
958 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
959 }
960
961 /*
962 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
963 * obey locking protocols, and offer a significantly less complex interface.
964 */
965 int
966 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
967 long *offset)
968 {
969 int error;
970
971 KLD_LOCK();
972 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
973 KLD_UNLOCK();
974 return (error);
975 }
976
977 /*
978 * Syscalls.
979 */
980 int
981 kern_kldload(struct thread *td, const char *file, int *fileid)
982 {
983 #ifdef HWPMC_HOOKS
984 struct pmckern_map_in pkm;
985 #endif
986 const char *kldname, *modname;
987 linker_file_t lf;
988 int error;
989
990 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
991 return (error);
992
993 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
994 return (error);
995
996 /*
997 * It is possible that kldloaded module will attach a new ifnet,
998 * so vnet context must be set when this ocurs.
999 */
1000 CURVNET_SET(TD_TO_VNET(td));
1001
1002 /*
1003 * If file does not contain a qualified name or any dot in it
1004 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1005 * name.
1006 */
1007 if (index(file, '/') || index(file, '.')) {
1008 kldname = file;
1009 modname = NULL;
1010 } else {
1011 kldname = NULL;
1012 modname = file;
1013 }
1014
1015 KLD_LOCK();
1016 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1017 if (error)
1018 goto unlock;
1019 #ifdef HWPMC_HOOKS
1020 pkm.pm_file = lf->filename;
1021 pkm.pm_address = (uintptr_t) lf->address;
1022 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
1023 #endif
1024 lf->userrefs++;
1025 if (fileid != NULL)
1026 *fileid = lf->id;
1027 unlock:
1028 KLD_UNLOCK();
1029 CURVNET_RESTORE();
1030 return (error);
1031 }
1032
1033 int
1034 kldload(struct thread *td, struct kldload_args *uap)
1035 {
1036 char *pathname = NULL;
1037 int error, fileid;
1038
1039 td->td_retval[0] = -1;
1040
1041 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1042 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1043 if (error == 0) {
1044 error = kern_kldload(td, pathname, &fileid);
1045 if (error == 0)
1046 td->td_retval[0] = fileid;
1047 }
1048 free(pathname, M_TEMP);
1049 return (error);
1050 }
1051
1052 int
1053 kern_kldunload(struct thread *td, int fileid, int flags)
1054 {
1055 #ifdef HWPMC_HOOKS
1056 struct pmckern_map_out pkm;
1057 #endif
1058 linker_file_t lf;
1059 int error = 0;
1060
1061 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1062 return (error);
1063
1064 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1065 return (error);
1066
1067 CURVNET_SET(TD_TO_VNET(td));
1068 KLD_LOCK();
1069 lf = linker_find_file_by_id(fileid);
1070 if (lf) {
1071 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1072
1073 /* Check if there are DTrace probes enabled on this file. */
1074 if (lf->nenabled > 0) {
1075 printf("kldunload: attempt to unload file that has"
1076 " DTrace probes enabled\n");
1077 error = EBUSY;
1078 } else if (lf->userrefs == 0) {
1079 /*
1080 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1081 */
1082 printf("kldunload: attempt to unload file that was"
1083 " loaded by the kernel\n");
1084 error = EBUSY;
1085 } else {
1086 #ifdef HWPMC_HOOKS
1087 /* Save data needed by hwpmc(4) before unloading. */
1088 pkm.pm_address = (uintptr_t) lf->address;
1089 pkm.pm_size = lf->size;
1090 #endif
1091 lf->userrefs--;
1092 error = linker_file_unload(lf, flags);
1093 if (error)
1094 lf->userrefs++;
1095 }
1096 } else
1097 error = ENOENT;
1098
1099 #ifdef HWPMC_HOOKS
1100 if (error == 0)
1101 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
1102 #endif
1103 KLD_UNLOCK();
1104 CURVNET_RESTORE();
1105 return (error);
1106 }
1107
1108 int
1109 kldunload(struct thread *td, struct kldunload_args *uap)
1110 {
1111
1112 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1113 }
1114
1115 int
1116 kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1117 {
1118
1119 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1120 uap->flags != LINKER_UNLOAD_FORCE)
1121 return (EINVAL);
1122 return (kern_kldunload(td, uap->fileid, uap->flags));
1123 }
1124
1125 int
1126 kldfind(struct thread *td, struct kldfind_args *uap)
1127 {
1128 char *pathname;
1129 const char *filename;
1130 linker_file_t lf;
1131 int error;
1132
1133 #ifdef MAC
1134 error = mac_kld_check_stat(td->td_ucred);
1135 if (error)
1136 return (error);
1137 #endif
1138
1139 td->td_retval[0] = -1;
1140
1141 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1142 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1143 goto out;
1144
1145 filename = linker_basename(pathname);
1146 KLD_LOCK();
1147 lf = linker_find_file_by_name(filename);
1148 if (lf)
1149 td->td_retval[0] = lf->id;
1150 else
1151 error = ENOENT;
1152 KLD_UNLOCK();
1153 out:
1154 free(pathname, M_TEMP);
1155 return (error);
1156 }
1157
1158 int
1159 kldnext(struct thread *td, struct kldnext_args *uap)
1160 {
1161 linker_file_t lf;
1162 int error = 0;
1163
1164 #ifdef MAC
1165 error = mac_kld_check_stat(td->td_ucred);
1166 if (error)
1167 return (error);
1168 #endif
1169
1170 KLD_LOCK();
1171 if (uap->fileid == 0)
1172 lf = TAILQ_FIRST(&linker_files);
1173 else {
1174 lf = linker_find_file_by_id(uap->fileid);
1175 if (lf == NULL) {
1176 error = ENOENT;
1177 goto out;
1178 }
1179 lf = TAILQ_NEXT(lf, link);
1180 }
1181
1182 /* Skip partially loaded files. */
1183 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1184 lf = TAILQ_NEXT(lf, link);
1185
1186 if (lf)
1187 td->td_retval[0] = lf->id;
1188 else
1189 td->td_retval[0] = 0;
1190 out:
1191 KLD_UNLOCK();
1192 return (error);
1193 }
1194
1195 int
1196 kldstat(struct thread *td, struct kldstat_args *uap)
1197 {
1198 struct kld_file_stat stat;
1199 linker_file_t lf;
1200 int error, namelen, version, version_num;
1201
1202 /*
1203 * Check the version of the user's structure.
1204 */
1205 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0)
1206 return (error);
1207 if (version == sizeof(struct kld_file_stat_1))
1208 version_num = 1;
1209 else if (version == sizeof(struct kld_file_stat))
1210 version_num = 2;
1211 else
1212 return (EINVAL);
1213
1214 #ifdef MAC
1215 error = mac_kld_check_stat(td->td_ucred);
1216 if (error)
1217 return (error);
1218 #endif
1219
1220 KLD_LOCK();
1221 lf = linker_find_file_by_id(uap->fileid);
1222 if (lf == NULL) {
1223 KLD_UNLOCK();
1224 return (ENOENT);
1225 }
1226
1227 /* Version 1 fields: */
1228 namelen = strlen(lf->filename) + 1;
1229 if (namelen > MAXPATHLEN)
1230 namelen = MAXPATHLEN;
1231 bcopy(lf->filename, &stat.name[0], namelen);
1232 stat.refs = lf->refs;
1233 stat.id = lf->id;
1234 stat.address = lf->address;
1235 stat.size = lf->size;
1236 if (version_num > 1) {
1237 /* Version 2 fields: */
1238 namelen = strlen(lf->pathname) + 1;
1239 if (namelen > MAXPATHLEN)
1240 namelen = MAXPATHLEN;
1241 bcopy(lf->pathname, &stat.pathname[0], namelen);
1242 }
1243 KLD_UNLOCK();
1244
1245 td->td_retval[0] = 0;
1246
1247 return (copyout(&stat, uap->stat, version));
1248 }
1249
1250 int
1251 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1252 {
1253 linker_file_t lf;
1254 module_t mp;
1255 int error = 0;
1256
1257 #ifdef MAC
1258 error = mac_kld_check_stat(td->td_ucred);
1259 if (error)
1260 return (error);
1261 #endif
1262
1263 KLD_LOCK();
1264 lf = linker_find_file_by_id(uap->fileid);
1265 if (lf) {
1266 MOD_SLOCK;
1267 mp = TAILQ_FIRST(&lf->modules);
1268 if (mp != NULL)
1269 td->td_retval[0] = module_getid(mp);
1270 else
1271 td->td_retval[0] = 0;
1272 MOD_SUNLOCK;
1273 } else
1274 error = ENOENT;
1275 KLD_UNLOCK();
1276 return (error);
1277 }
1278
1279 int
1280 kldsym(struct thread *td, struct kldsym_args *uap)
1281 {
1282 char *symstr = NULL;
1283 c_linker_sym_t sym;
1284 linker_symval_t symval;
1285 linker_file_t lf;
1286 struct kld_sym_lookup lookup;
1287 int error = 0;
1288
1289 #ifdef MAC
1290 error = mac_kld_check_stat(td->td_ucred);
1291 if (error)
1292 return (error);
1293 #endif
1294
1295 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1296 return (error);
1297 if (lookup.version != sizeof(lookup) ||
1298 uap->cmd != KLDSYM_LOOKUP)
1299 return (EINVAL);
1300 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1301 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1302 goto out;
1303 KLD_LOCK();
1304 if (uap->fileid != 0) {
1305 lf = linker_find_file_by_id(uap->fileid);
1306 if (lf == NULL)
1307 error = ENOENT;
1308 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1309 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1310 lookup.symvalue = (uintptr_t) symval.value;
1311 lookup.symsize = symval.size;
1312 error = copyout(&lookup, uap->data, sizeof(lookup));
1313 } else
1314 error = ENOENT;
1315 } else {
1316 TAILQ_FOREACH(lf, &linker_files, link) {
1317 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1318 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1319 lookup.symvalue = (uintptr_t)symval.value;
1320 lookup.symsize = symval.size;
1321 error = copyout(&lookup, uap->data,
1322 sizeof(lookup));
1323 break;
1324 }
1325 }
1326 if (lf == NULL)
1327 error = ENOENT;
1328 }
1329 KLD_UNLOCK();
1330 out:
1331 free(symstr, M_TEMP);
1332 return (error);
1333 }
1334
1335 /*
1336 * Preloaded module support
1337 */
1338
1339 static modlist_t
1340 modlist_lookup(const char *name, int ver)
1341 {
1342 modlist_t mod;
1343
1344 TAILQ_FOREACH(mod, &found_modules, link) {
1345 if (strcmp(mod->name, name) == 0 &&
1346 (ver == 0 || mod->version == ver))
1347 return (mod);
1348 }
1349 return (NULL);
1350 }
1351
1352 static modlist_t
1353 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1354 {
1355 modlist_t mod, bestmod;
1356 int ver;
1357
1358 if (verinfo == NULL)
1359 return (modlist_lookup(name, 0));
1360 bestmod = NULL;
1361 TAILQ_FOREACH(mod, &found_modules, link) {
1362 if (strcmp(mod->name, name) != 0)
1363 continue;
1364 ver = mod->version;
1365 if (ver == verinfo->md_ver_preferred)
1366 return (mod);
1367 if (ver >= verinfo->md_ver_minimum &&
1368 ver <= verinfo->md_ver_maximum &&
1369 (bestmod == NULL || ver > bestmod->version))
1370 bestmod = mod;
1371 }
1372 return (bestmod);
1373 }
1374
1375 static modlist_t
1376 modlist_newmodule(const char *modname, int version, linker_file_t container)
1377 {
1378 modlist_t mod;
1379
1380 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1381 if (mod == NULL)
1382 panic("no memory for module list");
1383 mod->container = container;
1384 mod->name = modname;
1385 mod->version = version;
1386 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1387 return (mod);
1388 }
1389
1390 static void
1391 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1392 struct mod_metadata **stop, int preload)
1393 {
1394 struct mod_metadata *mp, **mdp;
1395 const char *modname;
1396 int ver;
1397
1398 for (mdp = start; mdp < stop; mdp++) {
1399 mp = *mdp;
1400 if (mp->md_type != MDT_VERSION)
1401 continue;
1402 modname = mp->md_cval;
1403 ver = ((struct mod_version *)mp->md_data)->mv_version;
1404 if (modlist_lookup(modname, ver) != NULL) {
1405 printf("module %s already present!\n", modname);
1406 /* XXX what can we do? this is a build error. :-( */
1407 continue;
1408 }
1409 modlist_newmodule(modname, ver, lf);
1410 }
1411 }
1412
1413 static void
1414 linker_preload(void *arg)
1415 {
1416 caddr_t modptr;
1417 const char *modname, *nmodname;
1418 char *modtype;
1419 linker_file_t lf, nlf;
1420 linker_class_t lc;
1421 int error;
1422 linker_file_list_t loaded_files;
1423 linker_file_list_t depended_files;
1424 struct mod_metadata *mp, *nmp;
1425 struct mod_metadata **start, **stop, **mdp, **nmdp;
1426 struct mod_depend *verinfo;
1427 int nver;
1428 int resolves;
1429 modlist_t mod;
1430 struct sysinit **si_start, **si_stop;
1431
1432 TAILQ_INIT(&loaded_files);
1433 TAILQ_INIT(&depended_files);
1434 TAILQ_INIT(&found_modules);
1435 error = 0;
1436
1437 modptr = NULL;
1438 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1439 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1440 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1441 if (modname == NULL) {
1442 printf("Preloaded module at %p does not have a"
1443 " name!\n", modptr);
1444 continue;
1445 }
1446 if (modtype == NULL) {
1447 printf("Preloaded module at %p does not have a type!\n",
1448 modptr);
1449 continue;
1450 }
1451 if (bootverbose)
1452 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1453 modptr);
1454 lf = NULL;
1455 TAILQ_FOREACH(lc, &classes, link) {
1456 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1457 if (!error)
1458 break;
1459 lf = NULL;
1460 }
1461 if (lf)
1462 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1463 }
1464
1465 /*
1466 * First get a list of stuff in the kernel.
1467 */
1468 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1469 &stop, NULL) == 0)
1470 linker_addmodules(linker_kernel_file, start, stop, 1);
1471
1472 /*
1473 * This is a once-off kinky bubble sort to resolve relocation
1474 * dependency requirements.
1475 */
1476 restart:
1477 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1478 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1479 &stop, NULL);
1480 /*
1481 * First, look to see if we would successfully link with this
1482 * stuff.
1483 */
1484 resolves = 1; /* unless we know otherwise */
1485 if (!error) {
1486 for (mdp = start; mdp < stop; mdp++) {
1487 mp = *mdp;
1488 if (mp->md_type != MDT_DEPEND)
1489 continue;
1490 modname = mp->md_cval;
1491 verinfo = mp->md_data;
1492 for (nmdp = start; nmdp < stop; nmdp++) {
1493 nmp = *nmdp;
1494 if (nmp->md_type != MDT_VERSION)
1495 continue;
1496 nmodname = nmp->md_cval;
1497 if (strcmp(modname, nmodname) == 0)
1498 break;
1499 }
1500 if (nmdp < stop) /* it's a self reference */
1501 continue;
1502
1503 /*
1504 * ok, the module isn't here yet, we
1505 * are not finished
1506 */
1507 if (modlist_lookup2(modname, verinfo) == NULL)
1508 resolves = 0;
1509 }
1510 }
1511 /*
1512 * OK, if we found our modules, we can link. So, "provide"
1513 * the modules inside and add it to the end of the link order
1514 * list.
1515 */
1516 if (resolves) {
1517 if (!error) {
1518 for (mdp = start; mdp < stop; mdp++) {
1519 mp = *mdp;
1520 if (mp->md_type != MDT_VERSION)
1521 continue;
1522 modname = mp->md_cval;
1523 nver = ((struct mod_version *)
1524 mp->md_data)->mv_version;
1525 if (modlist_lookup(modname,
1526 nver) != NULL) {
1527 printf("module %s already"
1528 " present!\n", modname);
1529 TAILQ_REMOVE(&loaded_files,
1530 lf, loaded);
1531 linker_file_unload(lf,
1532 LINKER_UNLOAD_FORCE);
1533 /* we changed tailq next ptr */
1534 goto restart;
1535 }
1536 modlist_newmodule(modname, nver, lf);
1537 }
1538 }
1539 TAILQ_REMOVE(&loaded_files, lf, loaded);
1540 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1541 /*
1542 * Since we provided modules, we need to restart the
1543 * sort so that the previous files that depend on us
1544 * have a chance. Also, we've busted the tailq next
1545 * pointer with the REMOVE.
1546 */
1547 goto restart;
1548 }
1549 }
1550
1551 /*
1552 * At this point, we check to see what could not be resolved..
1553 */
1554 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1555 TAILQ_REMOVE(&loaded_files, lf, loaded);
1556 printf("KLD file %s is missing dependencies\n", lf->filename);
1557 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1558 }
1559
1560 /*
1561 * We made it. Finish off the linking in the order we determined.
1562 */
1563 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1564 if (linker_kernel_file) {
1565 linker_kernel_file->refs++;
1566 error = linker_file_add_dependency(lf,
1567 linker_kernel_file);
1568 if (error)
1569 panic("cannot add dependency");
1570 }
1571 lf->userrefs++; /* so we can (try to) kldunload it */
1572 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1573 &stop, NULL);
1574 if (!error) {
1575 for (mdp = start; mdp < stop; mdp++) {
1576 mp = *mdp;
1577 if (mp->md_type != MDT_DEPEND)
1578 continue;
1579 modname = mp->md_cval;
1580 verinfo = mp->md_data;
1581 mod = modlist_lookup2(modname, verinfo);
1582 /* Don't count self-dependencies */
1583 if (lf == mod->container)
1584 continue;
1585 mod->container->refs++;
1586 error = linker_file_add_dependency(lf,
1587 mod->container);
1588 if (error)
1589 panic("cannot add dependency");
1590 }
1591 }
1592 /*
1593 * Now do relocation etc using the symbol search paths
1594 * established by the dependencies
1595 */
1596 error = LINKER_LINK_PRELOAD_FINISH(lf);
1597 if (error) {
1598 TAILQ_REMOVE(&depended_files, lf, loaded);
1599 printf("KLD file %s - could not finalize loading\n",
1600 lf->filename);
1601 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1602 continue;
1603 }
1604 linker_file_register_modules(lf);
1605 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1606 &si_stop, NULL) == 0)
1607 sysinit_add(si_start, si_stop);
1608 linker_file_register_sysctls(lf);
1609 lf->flags |= LINKER_FILE_LINKED;
1610 }
1611 /* woohoo! we made it! */
1612 }
1613
1614 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1615
1616 /*
1617 * Search for a not-loaded module by name.
1618 *
1619 * Modules may be found in the following locations:
1620 *
1621 * - preloaded (result is just the module name) - on disk (result is full path
1622 * to module)
1623 *
1624 * If the module name is qualified in any way (contains path, etc.) the we
1625 * simply return a copy of it.
1626 *
1627 * The search path can be manipulated via sysctl. Note that we use the ';'
1628 * character as a separator to be consistent with the bootloader.
1629 */
1630
1631 static char linker_hintfile[] = "linker.hints";
1632 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1633
1634 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1635 sizeof(linker_path), "module load search path");
1636
1637 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1638
1639 static char *linker_ext_list[] = {
1640 "",
1641 ".ko",
1642 NULL
1643 };
1644
1645 /*
1646 * Check if file actually exists either with or without extension listed in
1647 * the linker_ext_list. (probably should be generic for the rest of the
1648 * kernel)
1649 */
1650 static char *
1651 linker_lookup_file(const char *path, int pathlen, const char *name,
1652 int namelen, struct vattr *vap)
1653 {
1654 struct nameidata nd;
1655 struct thread *td = curthread; /* XXX */
1656 char *result, **cpp, *sep;
1657 int error, len, extlen, reclen, flags, vfslocked;
1658 enum vtype type;
1659
1660 extlen = 0;
1661 for (cpp = linker_ext_list; *cpp; cpp++) {
1662 len = strlen(*cpp);
1663 if (len > extlen)
1664 extlen = len;
1665 }
1666 extlen++; /* trailing '\0' */
1667 sep = (path[pathlen - 1] != '/') ? "/" : "";
1668
1669 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1670 result = malloc(reclen, M_LINKER, M_WAITOK);
1671 for (cpp = linker_ext_list; *cpp; cpp++) {
1672 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1673 namelen, name, *cpp);
1674 /*
1675 * Attempt to open the file, and return the path if
1676 * we succeed and it's a regular file.
1677 */
1678 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
1679 flags = FREAD;
1680 error = vn_open(&nd, &flags, 0, NULL);
1681 if (error == 0) {
1682 vfslocked = NDHASGIANT(&nd);
1683 NDFREE(&nd, NDF_ONLY_PNBUF);
1684 type = nd.ni_vp->v_type;
1685 if (vap)
1686 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1687 VOP_UNLOCK(nd.ni_vp, 0);
1688 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1689 VFS_UNLOCK_GIANT(vfslocked);
1690 if (type == VREG)
1691 return (result);
1692 }
1693 }
1694 free(result, M_LINKER);
1695 return (NULL);
1696 }
1697
1698 #define INT_ALIGN(base, ptr) ptr = \
1699 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1700
1701 /*
1702 * Lookup KLD which contains requested module in the "linker.hints" file. If
1703 * version specification is available, then try to find the best KLD.
1704 * Otherwise just find the latest one.
1705 */
1706 static char *
1707 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1708 int modnamelen, struct mod_depend *verinfo)
1709 {
1710 struct thread *td = curthread; /* XXX */
1711 struct ucred *cred = td ? td->td_ucred : NULL;
1712 struct nameidata nd;
1713 struct vattr vattr, mattr;
1714 u_char *hints = NULL;
1715 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1716 int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
1717 int vfslocked = 0;
1718
1719 result = NULL;
1720 bestver = found = 0;
1721
1722 sep = (path[pathlen - 1] != '/') ? "/" : "";
1723 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1724 strlen(sep) + 1;
1725 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1726 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1727 linker_hintfile);
1728
1729 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
1730 flags = FREAD;
1731 error = vn_open(&nd, &flags, 0, NULL);
1732 if (error)
1733 goto bad;
1734 vfslocked = NDHASGIANT(&nd);
1735 NDFREE(&nd, NDF_ONLY_PNBUF);
1736 if (nd.ni_vp->v_type != VREG)
1737 goto bad;
1738 best = cp = NULL;
1739 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1740 if (error)
1741 goto bad;
1742 /*
1743 * XXX: we need to limit this number to some reasonable value
1744 */
1745 if (vattr.va_size > 100 * 1024) {
1746 printf("hints file too large %ld\n", (long)vattr.va_size);
1747 goto bad;
1748 }
1749 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1750 if (hints == NULL)
1751 goto bad;
1752 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1753 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1754 if (error)
1755 goto bad;
1756 VOP_UNLOCK(nd.ni_vp, 0);
1757 vn_close(nd.ni_vp, FREAD, cred, td);
1758 VFS_UNLOCK_GIANT(vfslocked);
1759 nd.ni_vp = NULL;
1760 if (reclen != 0) {
1761 printf("can't read %d\n", reclen);
1762 goto bad;
1763 }
1764 intp = (int *)hints;
1765 ival = *intp++;
1766 if (ival != LINKER_HINTS_VERSION) {
1767 printf("hints file version mismatch %d\n", ival);
1768 goto bad;
1769 }
1770 bufend = hints + vattr.va_size;
1771 recptr = (u_char *)intp;
1772 clen = blen = 0;
1773 while (recptr < bufend && !found) {
1774 intp = (int *)recptr;
1775 reclen = *intp++;
1776 ival = *intp++;
1777 cp = (char *)intp;
1778 switch (ival) {
1779 case MDT_VERSION:
1780 clen = *cp++;
1781 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1782 break;
1783 cp += clen;
1784 INT_ALIGN(hints, cp);
1785 ival = *(int *)cp;
1786 cp += sizeof(int);
1787 clen = *cp++;
1788 if (verinfo == NULL ||
1789 ival == verinfo->md_ver_preferred) {
1790 found = 1;
1791 break;
1792 }
1793 if (ival >= verinfo->md_ver_minimum &&
1794 ival <= verinfo->md_ver_maximum &&
1795 ival > bestver) {
1796 bestver = ival;
1797 best = cp;
1798 blen = clen;
1799 }
1800 break;
1801 default:
1802 break;
1803 }
1804 recptr += reclen + sizeof(int);
1805 }
1806 /*
1807 * Finally check if KLD is in the place
1808 */
1809 if (found)
1810 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1811 else if (best)
1812 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1813
1814 /*
1815 * KLD is newer than hints file. What we should do now?
1816 */
1817 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1818 printf("warning: KLD '%s' is newer than the linker.hints"
1819 " file\n", result);
1820 bad:
1821 free(pathbuf, M_LINKER);
1822 if (hints)
1823 free(hints, M_TEMP);
1824 if (nd.ni_vp != NULL) {
1825 VOP_UNLOCK(nd.ni_vp, 0);
1826 vn_close(nd.ni_vp, FREAD, cred, td);
1827 VFS_UNLOCK_GIANT(vfslocked);
1828 }
1829 /*
1830 * If nothing found or hints is absent - fallback to the old
1831 * way by using "kldname[.ko]" as module name.
1832 */
1833 if (!found && !bestver && result == NULL)
1834 result = linker_lookup_file(path, pathlen, modname,
1835 modnamelen, NULL);
1836 return (result);
1837 }
1838
1839 /*
1840 * Lookup KLD which contains requested module in the all directories.
1841 */
1842 static char *
1843 linker_search_module(const char *modname, int modnamelen,
1844 struct mod_depend *verinfo)
1845 {
1846 char *cp, *ep, *result;
1847
1848 /*
1849 * traverse the linker path
1850 */
1851 for (cp = linker_path; *cp; cp = ep + 1) {
1852 /* find the end of this component */
1853 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1854 result = linker_hints_lookup(cp, ep - cp, modname,
1855 modnamelen, verinfo);
1856 if (result != NULL)
1857 return (result);
1858 if (*ep == 0)
1859 break;
1860 }
1861 return (NULL);
1862 }
1863
1864 /*
1865 * Search for module in all directories listed in the linker_path.
1866 */
1867 static char *
1868 linker_search_kld(const char *name)
1869 {
1870 char *cp, *ep, *result;
1871 int len;
1872
1873 /* qualified at all? */
1874 if (index(name, '/'))
1875 return (linker_strdup(name));
1876
1877 /* traverse the linker path */
1878 len = strlen(name);
1879 for (ep = linker_path; *ep; ep++) {
1880 cp = ep;
1881 /* find the end of this component */
1882 for (; *ep != 0 && *ep != ';'; ep++);
1883 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1884 if (result != NULL)
1885 return (result);
1886 }
1887 return (NULL);
1888 }
1889
1890 static const char *
1891 linker_basename(const char *path)
1892 {
1893 const char *filename;
1894
1895 filename = rindex(path, '/');
1896 if (filename == NULL)
1897 return path;
1898 if (filename[1])
1899 filename++;
1900 return (filename);
1901 }
1902
1903 #ifdef HWPMC_HOOKS
1904 /*
1905 * Inform hwpmc about the set of kernel modules currently loaded.
1906 */
1907 void *
1908 linker_hwpmc_list_objects(void)
1909 {
1910 linker_file_t lf;
1911 struct pmckern_map_in *kobase;
1912 int i, nmappings;
1913
1914 nmappings = 0;
1915 KLD_LOCK();
1916 TAILQ_FOREACH(lf, &linker_files, link)
1917 nmappings++;
1918
1919 /* Allocate nmappings + 1 entries. */
1920 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1921 M_LINKER, M_WAITOK | M_ZERO);
1922 i = 0;
1923 TAILQ_FOREACH(lf, &linker_files, link) {
1924
1925 /* Save the info for this linker file. */
1926 kobase[i].pm_file = lf->filename;
1927 kobase[i].pm_address = (uintptr_t)lf->address;
1928 i++;
1929 }
1930 KLD_UNLOCK();
1931
1932 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1933
1934 /* The last entry of the malloced area comprises of all zeros. */
1935 KASSERT(kobase[i].pm_file == NULL,
1936 ("linker_hwpmc_list_objects: last object not NULL"));
1937
1938 return ((void *)kobase);
1939 }
1940 #endif
1941
1942 /*
1943 * Find a file which contains given module and load it, if "parent" is not
1944 * NULL, register a reference to it.
1945 */
1946 static int
1947 linker_load_module(const char *kldname, const char *modname,
1948 struct linker_file *parent, struct mod_depend *verinfo,
1949 struct linker_file **lfpp)
1950 {
1951 linker_file_t lfdep;
1952 const char *filename;
1953 char *pathname;
1954 int error;
1955
1956 KLD_LOCK_ASSERT();
1957 if (modname == NULL) {
1958 /*
1959 * We have to load KLD
1960 */
1961 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1962 " is not NULL"));
1963 pathname = linker_search_kld(kldname);
1964 } else {
1965 if (modlist_lookup2(modname, verinfo) != NULL)
1966 return (EEXIST);
1967 if (kldname != NULL)
1968 pathname = linker_strdup(kldname);
1969 else if (rootvnode == NULL)
1970 pathname = NULL;
1971 else
1972 /*
1973 * Need to find a KLD with required module
1974 */
1975 pathname = linker_search_module(modname,
1976 strlen(modname), verinfo);
1977 }
1978 if (pathname == NULL)
1979 return (ENOENT);
1980
1981 /*
1982 * Can't load more than one file with the same basename XXX:
1983 * Actually it should be possible to have multiple KLDs with
1984 * the same basename but different path because they can
1985 * provide different versions of the same modules.
1986 */
1987 filename = linker_basename(pathname);
1988 if (linker_find_file_by_name(filename))
1989 error = EEXIST;
1990 else do {
1991 error = linker_load_file(pathname, &lfdep);
1992 if (error)
1993 break;
1994 if (modname && verinfo &&
1995 modlist_lookup2(modname, verinfo) == NULL) {
1996 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
1997 error = ENOENT;
1998 break;
1999 }
2000 if (parent) {
2001 error = linker_file_add_dependency(parent, lfdep);
2002 if (error)
2003 break;
2004 }
2005 if (lfpp)
2006 *lfpp = lfdep;
2007 } while (0);
2008 free(pathname, M_LINKER);
2009 return (error);
2010 }
2011
2012 /*
2013 * This routine is responsible for finding dependencies of userland initiated
2014 * kldload(2)'s of files.
2015 */
2016 int
2017 linker_load_dependencies(linker_file_t lf)
2018 {
2019 linker_file_t lfdep;
2020 struct mod_metadata **start, **stop, **mdp, **nmdp;
2021 struct mod_metadata *mp, *nmp;
2022 struct mod_depend *verinfo;
2023 modlist_t mod;
2024 const char *modname, *nmodname;
2025 int ver, error = 0, count;
2026
2027 /*
2028 * All files are dependant on /kernel.
2029 */
2030 KLD_LOCK_ASSERT();
2031 if (linker_kernel_file) {
2032 linker_kernel_file->refs++;
2033 error = linker_file_add_dependency(lf, linker_kernel_file);
2034 if (error)
2035 return (error);
2036 }
2037 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2038 &count) != 0)
2039 return (0);
2040 for (mdp = start; mdp < stop; mdp++) {
2041 mp = *mdp;
2042 if (mp->md_type != MDT_VERSION)
2043 continue;
2044 modname = mp->md_cval;
2045 ver = ((struct mod_version *)mp->md_data)->mv_version;
2046 mod = modlist_lookup(modname, ver);
2047 if (mod != NULL) {
2048 printf("interface %s.%d already present in the KLD"
2049 " '%s'!\n", modname, ver,
2050 mod->container->filename);
2051 return (EEXIST);
2052 }
2053 }
2054
2055 for (mdp = start; mdp < stop; mdp++) {
2056 mp = *mdp;
2057 if (mp->md_type != MDT_DEPEND)
2058 continue;
2059 modname = mp->md_cval;
2060 verinfo = mp->md_data;
2061 nmodname = NULL;
2062 for (nmdp = start; nmdp < stop; nmdp++) {
2063 nmp = *nmdp;
2064 if (nmp->md_type != MDT_VERSION)
2065 continue;
2066 nmodname = nmp->md_cval;
2067 if (strcmp(modname, nmodname) == 0)
2068 break;
2069 }
2070 if (nmdp < stop)/* early exit, it's a self reference */
2071 continue;
2072 mod = modlist_lookup2(modname, verinfo);
2073 if (mod) { /* woohoo, it's loaded already */
2074 lfdep = mod->container;
2075 lfdep->refs++;
2076 error = linker_file_add_dependency(lf, lfdep);
2077 if (error)
2078 break;
2079 continue;
2080 }
2081 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2082 if (error) {
2083 printf("KLD %s: depends on %s - not available or"
2084 " version mismatch\n", lf->filename, modname);
2085 break;
2086 }
2087 }
2088
2089 if (error)
2090 return (error);
2091 linker_addmodules(lf, start, stop, 0);
2092 return (error);
2093 }
2094
2095 static int
2096 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2097 {
2098 struct sysctl_req *req;
2099
2100 req = opaque;
2101 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2102 }
2103
2104 /*
2105 * Export a nul-separated, double-nul-terminated list of all function names
2106 * in the kernel.
2107 */
2108 static int
2109 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2110 {
2111 linker_file_t lf;
2112 int error;
2113
2114 #ifdef MAC
2115 error = mac_kld_check_stat(req->td->td_ucred);
2116 if (error)
2117 return (error);
2118 #endif
2119 error = sysctl_wire_old_buffer(req, 0);
2120 if (error != 0)
2121 return (error);
2122 KLD_LOCK();
2123 TAILQ_FOREACH(lf, &linker_files, link) {
2124 error = LINKER_EACH_FUNCTION_NAME(lf,
2125 sysctl_kern_function_list_iterate, req);
2126 if (error) {
2127 KLD_UNLOCK();
2128 return (error);
2129 }
2130 }
2131 KLD_UNLOCK();
2132 return (SYSCTL_OUT(req, "", 1));
2133 }
2134
2135 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
2136 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: f9339cb546f3d2d6720d82b55a772c16
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