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/9.0/sys/kern/kern_linker.c 225617 2011-09-16 13:58:51Z kmacy $");
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 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW,
68 &kld_debug, 0, "Set various levels of KLD debug");
69 #endif
70
71 #define KLD_LOCK() sx_xlock(&kld_sx)
72 #define KLD_UNLOCK() sx_xunlock(&kld_sx)
73 #define KLD_DOWNGRADE() sx_downgrade(&kld_sx)
74 #define KLD_LOCK_READ() sx_slock(&kld_sx)
75 #define KLD_UNLOCK_READ() sx_sunlock(&kld_sx)
76 #define KLD_LOCKED() sx_xlocked(&kld_sx)
77 #define KLD_LOCK_ASSERT() do { \
78 if (!cold) \
79 sx_assert(&kld_sx, SX_XLOCKED); \
80 } while (0)
81
82 /*
83 * static char *linker_search_path(const char *name, struct mod_depend
84 * *verinfo);
85 */
86 static const char *linker_basename(const char *path);
87
88 /*
89 * Find a currently loaded file given its filename.
90 */
91 static linker_file_t linker_find_file_by_name(const char* _filename);
92
93 /*
94 * Find a currently loaded file given its file id.
95 */
96 static linker_file_t linker_find_file_by_id(int _fileid);
97
98 /* Metadata from the static kernel */
99 SET_DECLARE(modmetadata_set, struct mod_metadata);
100
101 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
102
103 linker_file_t linker_kernel_file;
104
105 static struct sx kld_sx; /* kernel linker lock */
106
107 /*
108 * Load counter used by clients to determine if a linker file has been
109 * re-loaded. This counter is incremented for each file load.
110 */
111 static int loadcnt;
112
113 static linker_class_list_t classes;
114 static linker_file_list_t linker_files;
115 static int next_file_id = 1;
116 static int linker_no_more_classes = 0;
117
118 #define LINKER_GET_NEXT_FILE_ID(a) do { \
119 linker_file_t lftmp; \
120 \
121 KLD_LOCK_ASSERT(); \
122 retry: \
123 TAILQ_FOREACH(lftmp, &linker_files, link) { \
124 if (next_file_id == lftmp->id) { \
125 next_file_id++; \
126 goto retry; \
127 } \
128 } \
129 (a) = next_file_id; \
130 } while(0)
131
132
133 /* XXX wrong name; we're looking at version provision tags here, not modules */
134 typedef TAILQ_HEAD(, modlist) modlisthead_t;
135 struct modlist {
136 TAILQ_ENTRY(modlist) link; /* chain together all modules */
137 linker_file_t container;
138 const char *name;
139 int version;
140 };
141 typedef struct modlist *modlist_t;
142 static modlisthead_t found_modules;
143
144 static int linker_file_add_dependency(linker_file_t file,
145 linker_file_t dep);
146 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
147 const char* name, int deps);
148 static int linker_load_module(const char *kldname,
149 const char *modname, struct linker_file *parent,
150 struct mod_depend *verinfo, struct linker_file **lfpp);
151 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
152
153 static char *
154 linker_strdup(const char *str)
155 {
156 char *result;
157
158 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
159 strcpy(result, str);
160 return (result);
161 }
162
163 static void
164 linker_init(void *arg)
165 {
166
167 sx_init(&kld_sx, "kernel linker");
168 TAILQ_INIT(&classes);
169 TAILQ_INIT(&linker_files);
170 }
171
172 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
173
174 static void
175 linker_stop_class_add(void *arg)
176 {
177
178 linker_no_more_classes = 1;
179 }
180
181 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
182
183 int
184 linker_add_class(linker_class_t lc)
185 {
186
187 /*
188 * We disallow any class registration past SI_ORDER_ANY
189 * of SI_SUB_KLD. We bump the reference count to keep the
190 * ops from being freed.
191 */
192 if (linker_no_more_classes == 1)
193 return (EPERM);
194 kobj_class_compile((kobj_class_t) lc);
195 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */
196 TAILQ_INSERT_TAIL(&classes, lc, link);
197 return (0);
198 }
199
200 static void
201 linker_file_sysinit(linker_file_t lf)
202 {
203 struct sysinit **start, **stop, **sipp, **xipp, *save;
204
205 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
206 lf->filename));
207
208 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
209 return;
210 /*
211 * Perform a bubble sort of the system initialization objects by
212 * their subsystem (primary key) and order (secondary key).
213 *
214 * Since some things care about execution order, this is the operation
215 * which ensures continued function.
216 */
217 for (sipp = start; sipp < stop; sipp++) {
218 for (xipp = sipp + 1; xipp < stop; xipp++) {
219 if ((*sipp)->subsystem < (*xipp)->subsystem ||
220 ((*sipp)->subsystem == (*xipp)->subsystem &&
221 (*sipp)->order <= (*xipp)->order))
222 continue; /* skip */
223 save = *sipp;
224 *sipp = *xipp;
225 *xipp = save;
226 }
227 }
228
229 /*
230 * Traverse the (now) ordered list of system initialization tasks.
231 * Perform each task, and continue on to the next task.
232 */
233 mtx_lock(&Giant);
234 for (sipp = start; sipp < stop; sipp++) {
235 if ((*sipp)->subsystem == SI_SUB_DUMMY)
236 continue; /* skip dummy task(s) */
237
238 /* Call function */
239 (*((*sipp)->func)) ((*sipp)->udata);
240 }
241 mtx_unlock(&Giant);
242 }
243
244 static void
245 linker_file_sysuninit(linker_file_t lf)
246 {
247 struct sysinit **start, **stop, **sipp, **xipp, *save;
248
249 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
250 lf->filename));
251
252 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
253 NULL) != 0)
254 return;
255
256 /*
257 * Perform a reverse bubble sort of the system initialization objects
258 * by their subsystem (primary key) and order (secondary key).
259 *
260 * Since some things care about execution order, this is the operation
261 * which ensures continued function.
262 */
263 for (sipp = start; sipp < stop; sipp++) {
264 for (xipp = sipp + 1; xipp < stop; xipp++) {
265 if ((*sipp)->subsystem > (*xipp)->subsystem ||
266 ((*sipp)->subsystem == (*xipp)->subsystem &&
267 (*sipp)->order >= (*xipp)->order))
268 continue; /* skip */
269 save = *sipp;
270 *sipp = *xipp;
271 *xipp = save;
272 }
273 }
274
275 /*
276 * Traverse the (now) ordered list of system initialization tasks.
277 * Perform each task, and continue on to the next task.
278 */
279 mtx_lock(&Giant);
280 for (sipp = start; sipp < stop; sipp++) {
281 if ((*sipp)->subsystem == SI_SUB_DUMMY)
282 continue; /* skip dummy task(s) */
283
284 /* Call function */
285 (*((*sipp)->func)) ((*sipp)->udata);
286 }
287 mtx_unlock(&Giant);
288 }
289
290 static void
291 linker_file_register_sysctls(linker_file_t lf)
292 {
293 struct sysctl_oid **start, **stop, **oidp;
294
295 KLD_DPF(FILE,
296 ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
297 lf->filename));
298
299 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
300 return;
301
302 sysctl_lock();
303 for (oidp = start; oidp < stop; oidp++)
304 sysctl_register_oid(*oidp);
305 sysctl_unlock();
306 }
307
308 static void
309 linker_file_unregister_sysctls(linker_file_t lf)
310 {
311 struct sysctl_oid **start, **stop, **oidp;
312
313 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
314 " for %s\n", lf->filename));
315
316 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
317 return;
318
319 sysctl_lock();
320 for (oidp = start; oidp < stop; oidp++)
321 sysctl_unregister_oid(*oidp);
322 sysctl_unlock();
323 }
324
325 static int
326 linker_file_register_modules(linker_file_t lf)
327 {
328 struct mod_metadata **start, **stop, **mdp;
329 const moduledata_t *moddata;
330 int first_error, error;
331
332 KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
333 " in %s\n", lf->filename));
334
335 if (linker_file_lookup_set(lf, "modmetadata_set", &start,
336 &stop, NULL) != 0) {
337 /*
338 * This fallback should be unnecessary, but if we get booted
339 * from boot2 instead of loader and we are missing our
340 * metadata then we have to try the best we can.
341 */
342 if (lf == linker_kernel_file) {
343 start = SET_BEGIN(modmetadata_set);
344 stop = SET_LIMIT(modmetadata_set);
345 } else
346 return (0);
347 }
348 first_error = 0;
349 for (mdp = start; mdp < stop; mdp++) {
350 if ((*mdp)->md_type != MDT_MODULE)
351 continue;
352 moddata = (*mdp)->md_data;
353 KLD_DPF(FILE, ("Registering module %s in %s\n",
354 moddata->name, lf->filename));
355 error = module_register(moddata, lf);
356 if (error) {
357 printf("Module %s failed to register: %d\n",
358 moddata->name, error);
359 if (first_error == 0)
360 first_error = error;
361 }
362 }
363 return (first_error);
364 }
365
366 static void
367 linker_init_kernel_modules(void)
368 {
369
370 linker_file_register_modules(linker_kernel_file);
371 }
372
373 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
374 0);
375
376 static int
377 linker_load_file(const char *filename, linker_file_t *result)
378 {
379 linker_class_t lc;
380 linker_file_t lf;
381 int foundfile, error;
382
383 /* Refuse to load modules if securelevel raised */
384 if (prison0.pr_securelevel > 0)
385 return (EPERM);
386
387 KLD_LOCK_ASSERT();
388 lf = linker_find_file_by_name(filename);
389 if (lf) {
390 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
391 " incrementing refs\n", filename));
392 *result = lf;
393 lf->refs++;
394 return (0);
395 }
396 foundfile = 0;
397 error = 0;
398
399 /*
400 * We do not need to protect (lock) classes here because there is
401 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
402 * and there is no class deregistration mechanism at this time.
403 */
404 TAILQ_FOREACH(lc, &classes, link) {
405 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
406 filename));
407 error = LINKER_LOAD_FILE(lc, filename, &lf);
408 /*
409 * If we got something other than ENOENT, then it exists but
410 * we cannot load it for some other reason.
411 */
412 if (error != ENOENT)
413 foundfile = 1;
414 if (lf) {
415 error = linker_file_register_modules(lf);
416 if (error == EEXIST) {
417 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
418 return (error);
419 }
420 KLD_UNLOCK();
421 linker_file_register_sysctls(lf);
422 linker_file_sysinit(lf);
423 KLD_LOCK();
424 lf->flags |= LINKER_FILE_LINKED;
425 *result = lf;
426 return (0);
427 }
428 }
429 /*
430 * Less than ideal, but tells the user whether it failed to load or
431 * the module was not found.
432 */
433 if (foundfile) {
434
435 /*
436 * If the file type has not been recognized by the last try
437 * printout a message before to fail.
438 */
439 if (error == ENOSYS)
440 printf("linker_load_file: Unsupported file type\n");
441
442 /*
443 * Format not recognized or otherwise unloadable.
444 * When loading a module that is statically built into
445 * the kernel EEXIST percolates back up as the return
446 * value. Preserve this so that apps like sysinstall
447 * can recognize this special case and not post bogus
448 * dialog boxes.
449 */
450 if (error != EEXIST)
451 error = ENOEXEC;
452 } else
453 error = ENOENT; /* Nothing found */
454 return (error);
455 }
456
457 int
458 linker_reference_module(const char *modname, struct mod_depend *verinfo,
459 linker_file_t *result)
460 {
461 modlist_t mod;
462 int error;
463
464 KLD_LOCK();
465 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
466 *result = mod->container;
467 (*result)->refs++;
468 KLD_UNLOCK();
469 return (0);
470 }
471
472 error = linker_load_module(NULL, modname, NULL, verinfo, result);
473 KLD_UNLOCK();
474 return (error);
475 }
476
477 int
478 linker_release_module(const char *modname, struct mod_depend *verinfo,
479 linker_file_t lf)
480 {
481 modlist_t mod;
482 int error;
483
484 KLD_LOCK();
485 if (lf == NULL) {
486 KASSERT(modname != NULL,
487 ("linker_release_module: no file or name"));
488 mod = modlist_lookup2(modname, verinfo);
489 if (mod == NULL) {
490 KLD_UNLOCK();
491 return (ESRCH);
492 }
493 lf = mod->container;
494 } else
495 KASSERT(modname == NULL && verinfo == NULL,
496 ("linker_release_module: both file and name"));
497 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
498 KLD_UNLOCK();
499 return (error);
500 }
501
502 static linker_file_t
503 linker_find_file_by_name(const char *filename)
504 {
505 linker_file_t lf;
506 char *koname;
507
508 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
509 sprintf(koname, "%s.ko", filename);
510
511 KLD_LOCK_ASSERT();
512 TAILQ_FOREACH(lf, &linker_files, link) {
513 if (strcmp(lf->filename, koname) == 0)
514 break;
515 if (strcmp(lf->filename, filename) == 0)
516 break;
517 }
518 free(koname, M_LINKER);
519 return (lf);
520 }
521
522 static linker_file_t
523 linker_find_file_by_id(int fileid)
524 {
525 linker_file_t lf;
526
527 KLD_LOCK_ASSERT();
528 TAILQ_FOREACH(lf, &linker_files, link)
529 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
530 break;
531 return (lf);
532 }
533
534 int
535 linker_file_foreach(linker_predicate_t *predicate, void *context)
536 {
537 linker_file_t lf;
538 int retval = 0;
539
540 KLD_LOCK();
541 TAILQ_FOREACH(lf, &linker_files, link) {
542 retval = predicate(lf, context);
543 if (retval != 0)
544 break;
545 }
546 KLD_UNLOCK();
547 return (retval);
548 }
549
550 linker_file_t
551 linker_make_file(const char *pathname, linker_class_t lc)
552 {
553 linker_file_t lf;
554 const char *filename;
555
556 KLD_LOCK_ASSERT();
557 filename = linker_basename(pathname);
558
559 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
560 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
561 if (lf == NULL)
562 return (NULL);
563 lf->refs = 1;
564 lf->userrefs = 0;
565 lf->flags = 0;
566 lf->filename = linker_strdup(filename);
567 lf->pathname = linker_strdup(pathname);
568 LINKER_GET_NEXT_FILE_ID(lf->id);
569 lf->ndeps = 0;
570 lf->deps = NULL;
571 lf->loadcnt = ++loadcnt;
572 lf->sdt_probes = NULL;
573 lf->sdt_nprobes = 0;
574 STAILQ_INIT(&lf->common);
575 TAILQ_INIT(&lf->modules);
576 TAILQ_INSERT_TAIL(&linker_files, lf, link);
577 return (lf);
578 }
579
580 int
581 linker_file_unload(linker_file_t file, int flags)
582 {
583 module_t mod, next;
584 modlist_t ml, nextml;
585 struct common_symbol *cp;
586 int error, i;
587
588 /* Refuse to unload modules if securelevel raised. */
589 if (prison0.pr_securelevel > 0)
590 return (EPERM);
591
592 KLD_LOCK_ASSERT();
593 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
594
595 /* Easy case of just dropping a reference. */
596 if (file->refs > 1) {
597 file->refs--;
598 return (0);
599 }
600
601 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
602 " informing modules\n"));
603
604 /*
605 * Quiesce all the modules to give them a chance to veto the unload.
606 */
607 MOD_SLOCK;
608 for (mod = TAILQ_FIRST(&file->modules); mod;
609 mod = module_getfnext(mod)) {
610
611 error = module_quiesce(mod);
612 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
613 KLD_DPF(FILE, ("linker_file_unload: module %s"
614 " vetoed unload\n", module_getname(mod)));
615 /*
616 * XXX: Do we need to tell all the quiesced modules
617 * that they can resume work now via a new module
618 * event?
619 */
620 MOD_SUNLOCK;
621 return (error);
622 }
623 }
624 MOD_SUNLOCK;
625
626 /*
627 * Inform any modules associated with this file that they are
628 * being be unloaded.
629 */
630 MOD_XLOCK;
631 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
632 next = module_getfnext(mod);
633 MOD_XUNLOCK;
634
635 /*
636 * Give the module a chance to veto the unload.
637 */
638 if ((error = module_unload(mod)) != 0) {
639 KLD_DPF(FILE, ("linker_file_unload: module %s"
640 " failed unload\n", module_getname(mod)));
641 return (error);
642 }
643 MOD_XLOCK;
644 module_release(mod);
645 }
646 MOD_XUNLOCK;
647
648 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
649 if (ml->container == file) {
650 TAILQ_REMOVE(&found_modules, ml, link);
651 free(ml, M_LINKER);
652 }
653 }
654
655 /*
656 * Don't try to run SYSUNINITs if we are unloaded due to a
657 * link error.
658 */
659 if (file->flags & LINKER_FILE_LINKED) {
660 file->flags &= ~LINKER_FILE_LINKED;
661 KLD_UNLOCK();
662 linker_file_sysuninit(file);
663 linker_file_unregister_sysctls(file);
664 KLD_LOCK();
665 }
666 TAILQ_REMOVE(&linker_files, file, link);
667
668 if (file->deps) {
669 for (i = 0; i < file->ndeps; i++)
670 linker_file_unload(file->deps[i], flags);
671 free(file->deps, M_LINKER);
672 file->deps = NULL;
673 }
674 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
675 STAILQ_REMOVE_HEAD(&file->common, link);
676 free(cp, M_LINKER);
677 }
678
679 LINKER_UNLOAD(file);
680 if (file->filename) {
681 free(file->filename, M_LINKER);
682 file->filename = NULL;
683 }
684 if (file->pathname) {
685 free(file->pathname, M_LINKER);
686 file->pathname = NULL;
687 }
688 kobj_delete((kobj_t) file, M_LINKER);
689 return (0);
690 }
691
692 int
693 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
694 {
695 return (LINKER_CTF_GET(file, lc));
696 }
697
698 static int
699 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
700 {
701 linker_file_t *newdeps;
702
703 KLD_LOCK_ASSERT();
704 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
705 M_LINKER, M_WAITOK | M_ZERO);
706 if (newdeps == NULL)
707 return (ENOMEM);
708
709 if (file->deps) {
710 bcopy(file->deps, newdeps,
711 file->ndeps * sizeof(linker_file_t *));
712 free(file->deps, M_LINKER);
713 }
714 file->deps = newdeps;
715 file->deps[file->ndeps] = dep;
716 file->ndeps++;
717 KLD_DPF(FILE, ("linker_file_add_dependency:"
718 " adding %s as dependency for %s\n",
719 dep->filename, file->filename));
720 return (0);
721 }
722
723 /*
724 * Locate a linker set and its contents. This is a helper function to avoid
725 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
726 * This function is used in this file so we can avoid having lots of (void **)
727 * casts.
728 */
729 int
730 linker_file_lookup_set(linker_file_t file, const char *name,
731 void *firstp, void *lastp, int *countp)
732 {
733 int error, locked;
734
735 locked = KLD_LOCKED();
736 if (!locked)
737 KLD_LOCK();
738 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
739 if (!locked)
740 KLD_UNLOCK();
741 return (error);
742 }
743
744 /*
745 * List all functions in a file.
746 */
747 int
748 linker_file_function_listall(linker_file_t lf,
749 linker_function_nameval_callback_t callback_func, void *arg)
750 {
751 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
752 }
753
754 caddr_t
755 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
756 {
757 caddr_t sym;
758 int locked;
759
760 locked = KLD_LOCKED();
761 if (!locked)
762 KLD_LOCK();
763 sym = linker_file_lookup_symbol_internal(file, name, deps);
764 if (!locked)
765 KLD_UNLOCK();
766 return (sym);
767 }
768
769 static caddr_t
770 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
771 int deps)
772 {
773 c_linker_sym_t sym;
774 linker_symval_t symval;
775 caddr_t address;
776 size_t common_size = 0;
777 int i;
778
779 KLD_LOCK_ASSERT();
780 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
781 file, name, deps));
782
783 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
784 LINKER_SYMBOL_VALUES(file, sym, &symval);
785 if (symval.value == 0)
786 /*
787 * For commons, first look them up in the
788 * dependencies and only allocate space if not found
789 * there.
790 */
791 common_size = symval.size;
792 else {
793 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
794 ".value=%p\n", symval.value));
795 return (symval.value);
796 }
797 }
798 if (deps) {
799 for (i = 0; i < file->ndeps; i++) {
800 address = linker_file_lookup_symbol_internal(
801 file->deps[i], name, 0);
802 if (address) {
803 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
804 " deps value=%p\n", address));
805 return (address);
806 }
807 }
808 }
809 if (common_size > 0) {
810 /*
811 * This is a common symbol which was not found in the
812 * dependencies. We maintain a simple common symbol table in
813 * the file object.
814 */
815 struct common_symbol *cp;
816
817 STAILQ_FOREACH(cp, &file->common, link) {
818 if (strcmp(cp->name, name) == 0) {
819 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
820 " old common value=%p\n", cp->address));
821 return (cp->address);
822 }
823 }
824 /*
825 * Round the symbol size up to align.
826 */
827 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
828 cp = malloc(sizeof(struct common_symbol)
829 + common_size + strlen(name) + 1, M_LINKER,
830 M_WAITOK | M_ZERO);
831 cp->address = (caddr_t)(cp + 1);
832 cp->name = cp->address + common_size;
833 strcpy(cp->name, name);
834 bzero(cp->address, common_size);
835 STAILQ_INSERT_TAIL(&file->common, cp, link);
836
837 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
838 " value=%p\n", cp->address));
839 return (cp->address);
840 }
841 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
842 return (0);
843 }
844
845 /*
846 * Both DDB and stack(9) rely on the kernel linker to provide forward and
847 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
848 * do this in a lockfree manner. We provide a set of internal helper
849 * routines to perform these operations without locks, and then wrappers that
850 * optionally lock.
851 *
852 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
853 */
854 #ifdef DDB
855 static int
856 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
857 {
858 linker_file_t lf;
859
860 TAILQ_FOREACH(lf, &linker_files, link) {
861 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
862 return (0);
863 }
864 return (ENOENT);
865 }
866 #endif
867
868 static int
869 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
870 {
871 linker_file_t lf;
872 c_linker_sym_t best, es;
873 u_long diff, bestdiff, off;
874
875 best = 0;
876 off = (uintptr_t)value;
877 bestdiff = off;
878 TAILQ_FOREACH(lf, &linker_files, link) {
879 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
880 continue;
881 if (es != 0 && diff < bestdiff) {
882 best = es;
883 bestdiff = diff;
884 }
885 if (bestdiff == 0)
886 break;
887 }
888 if (best) {
889 *sym = best;
890 *diffp = bestdiff;
891 return (0);
892 } else {
893 *sym = 0;
894 *diffp = off;
895 return (ENOENT);
896 }
897 }
898
899 static int
900 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
901 {
902 linker_file_t lf;
903
904 TAILQ_FOREACH(lf, &linker_files, link) {
905 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
906 return (0);
907 }
908 return (ENOENT);
909 }
910
911 static int
912 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
913 long *offset)
914 {
915 linker_symval_t symval;
916 c_linker_sym_t sym;
917 int error;
918
919 *offset = 0;
920 error = linker_debug_search_symbol(value, &sym, offset);
921 if (error)
922 return (error);
923 error = linker_debug_symbol_values(sym, &symval);
924 if (error)
925 return (error);
926 strlcpy(buf, symval.name, buflen);
927 return (0);
928 }
929
930 /*
931 * DDB Helpers. DDB has to look across multiple files with their own symbol
932 * tables and string tables.
933 *
934 * Note that we do not obey list locking protocols here. We really don't need
935 * DDB to hang because somebody's got the lock held. We'll take the chance
936 * that the files list is inconsistant instead.
937 */
938 #ifdef DDB
939 int
940 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
941 {
942
943 return (linker_debug_lookup(symstr, sym));
944 }
945 #endif
946
947 int
948 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
949 {
950
951 return (linker_debug_search_symbol(value, sym, diffp));
952 }
953
954 int
955 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
956 {
957
958 return (linker_debug_symbol_values(sym, symval));
959 }
960
961 int
962 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
963 long *offset)
964 {
965
966 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
967 }
968
969 /*
970 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
971 * obey locking protocols, and offer a significantly less complex interface.
972 */
973 int
974 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
975 long *offset)
976 {
977 int error;
978
979 KLD_LOCK();
980 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
981 KLD_UNLOCK();
982 return (error);
983 }
984
985 /*
986 * Syscalls.
987 */
988 int
989 kern_kldload(struct thread *td, const char *file, int *fileid)
990 {
991 #ifdef HWPMC_HOOKS
992 struct pmckern_map_in pkm;
993 #endif
994 const char *kldname, *modname;
995 linker_file_t lf;
996 int error;
997
998 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
999 return (error);
1000
1001 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1002 return (error);
1003
1004 /*
1005 * It is possible that kldloaded module will attach a new ifnet,
1006 * so vnet context must be set when this ocurs.
1007 */
1008 CURVNET_SET(TD_TO_VNET(td));
1009
1010 /*
1011 * If file does not contain a qualified name or any dot in it
1012 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1013 * name.
1014 */
1015 if (index(file, '/') || index(file, '.')) {
1016 kldname = file;
1017 modname = NULL;
1018 } else {
1019 kldname = NULL;
1020 modname = file;
1021 }
1022
1023 KLD_LOCK();
1024 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1025 if (error) {
1026 KLD_UNLOCK();
1027 goto done;
1028 }
1029 lf->userrefs++;
1030 if (fileid != NULL)
1031 *fileid = lf->id;
1032 #ifdef HWPMC_HOOKS
1033 KLD_DOWNGRADE();
1034 pkm.pm_file = lf->filename;
1035 pkm.pm_address = (uintptr_t) lf->address;
1036 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
1037 KLD_UNLOCK_READ();
1038 #else
1039 KLD_UNLOCK();
1040 #endif
1041
1042 done:
1043 CURVNET_RESTORE();
1044 return (error);
1045 }
1046
1047 int
1048 sys_kldload(struct thread *td, struct kldload_args *uap)
1049 {
1050 char *pathname = NULL;
1051 int error, fileid;
1052
1053 td->td_retval[0] = -1;
1054
1055 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1056 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1057 if (error == 0) {
1058 error = kern_kldload(td, pathname, &fileid);
1059 if (error == 0)
1060 td->td_retval[0] = fileid;
1061 }
1062 free(pathname, M_TEMP);
1063 return (error);
1064 }
1065
1066 int
1067 kern_kldunload(struct thread *td, int fileid, int flags)
1068 {
1069 #ifdef HWPMC_HOOKS
1070 struct pmckern_map_out pkm;
1071 #endif
1072 linker_file_t lf;
1073 int error = 0;
1074
1075 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1076 return (error);
1077
1078 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1079 return (error);
1080
1081 CURVNET_SET(TD_TO_VNET(td));
1082 KLD_LOCK();
1083 lf = linker_find_file_by_id(fileid);
1084 if (lf) {
1085 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1086
1087 /* Check if there are DTrace probes enabled on this file. */
1088 if (lf->nenabled > 0) {
1089 printf("kldunload: attempt to unload file that has"
1090 " DTrace probes enabled\n");
1091 error = EBUSY;
1092 } else if (lf->userrefs == 0) {
1093 /*
1094 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1095 */
1096 printf("kldunload: attempt to unload file that was"
1097 " loaded by the kernel\n");
1098 error = EBUSY;
1099 } else {
1100 #ifdef HWPMC_HOOKS
1101 /* Save data needed by hwpmc(4) before unloading. */
1102 pkm.pm_address = (uintptr_t) lf->address;
1103 pkm.pm_size = lf->size;
1104 #endif
1105 lf->userrefs--;
1106 error = linker_file_unload(lf, flags);
1107 if (error)
1108 lf->userrefs++;
1109 }
1110 } else
1111 error = ENOENT;
1112
1113 #ifdef HWPMC_HOOKS
1114 if (error == 0) {
1115 KLD_DOWNGRADE();
1116 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
1117 KLD_UNLOCK_READ();
1118 } else
1119 KLD_UNLOCK();
1120 #else
1121 KLD_UNLOCK();
1122 #endif
1123 CURVNET_RESTORE();
1124 return (error);
1125 }
1126
1127 int
1128 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1129 {
1130
1131 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1132 }
1133
1134 int
1135 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1136 {
1137
1138 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1139 uap->flags != LINKER_UNLOAD_FORCE)
1140 return (EINVAL);
1141 return (kern_kldunload(td, uap->fileid, uap->flags));
1142 }
1143
1144 int
1145 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1146 {
1147 char *pathname;
1148 const char *filename;
1149 linker_file_t lf;
1150 int error;
1151
1152 #ifdef MAC
1153 error = mac_kld_check_stat(td->td_ucred);
1154 if (error)
1155 return (error);
1156 #endif
1157
1158 td->td_retval[0] = -1;
1159
1160 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1161 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1162 goto out;
1163
1164 filename = linker_basename(pathname);
1165 KLD_LOCK();
1166 lf = linker_find_file_by_name(filename);
1167 if (lf)
1168 td->td_retval[0] = lf->id;
1169 else
1170 error = ENOENT;
1171 KLD_UNLOCK();
1172 out:
1173 free(pathname, M_TEMP);
1174 return (error);
1175 }
1176
1177 int
1178 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1179 {
1180 linker_file_t lf;
1181 int error = 0;
1182
1183 #ifdef MAC
1184 error = mac_kld_check_stat(td->td_ucred);
1185 if (error)
1186 return (error);
1187 #endif
1188
1189 KLD_LOCK();
1190 if (uap->fileid == 0)
1191 lf = TAILQ_FIRST(&linker_files);
1192 else {
1193 lf = linker_find_file_by_id(uap->fileid);
1194 if (lf == NULL) {
1195 error = ENOENT;
1196 goto out;
1197 }
1198 lf = TAILQ_NEXT(lf, link);
1199 }
1200
1201 /* Skip partially loaded files. */
1202 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1203 lf = TAILQ_NEXT(lf, link);
1204
1205 if (lf)
1206 td->td_retval[0] = lf->id;
1207 else
1208 td->td_retval[0] = 0;
1209 out:
1210 KLD_UNLOCK();
1211 return (error);
1212 }
1213
1214 int
1215 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1216 {
1217 struct kld_file_stat stat;
1218 int error, version;
1219
1220 /*
1221 * Check the version of the user's structure.
1222 */
1223 if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1224 != 0)
1225 return (error);
1226 if (version != sizeof(struct kld_file_stat_1) &&
1227 version != sizeof(struct kld_file_stat))
1228 return (EINVAL);
1229
1230 error = kern_kldstat(td, uap->fileid, &stat);
1231 if (error != 0)
1232 return (error);
1233 return (copyout(&stat, uap->stat, version));
1234 }
1235
1236 int
1237 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1238 {
1239 linker_file_t lf;
1240 int namelen;
1241 #ifdef MAC
1242 int error;
1243
1244 error = mac_kld_check_stat(td->td_ucred);
1245 if (error)
1246 return (error);
1247 #endif
1248
1249 KLD_LOCK();
1250 lf = linker_find_file_by_id(fileid);
1251 if (lf == NULL) {
1252 KLD_UNLOCK();
1253 return (ENOENT);
1254 }
1255
1256 /* Version 1 fields: */
1257 namelen = strlen(lf->filename) + 1;
1258 if (namelen > MAXPATHLEN)
1259 namelen = MAXPATHLEN;
1260 bcopy(lf->filename, &stat->name[0], namelen);
1261 stat->refs = lf->refs;
1262 stat->id = lf->id;
1263 stat->address = lf->address;
1264 stat->size = lf->size;
1265 /* Version 2 fields: */
1266 namelen = strlen(lf->pathname) + 1;
1267 if (namelen > MAXPATHLEN)
1268 namelen = MAXPATHLEN;
1269 bcopy(lf->pathname, &stat->pathname[0], namelen);
1270 KLD_UNLOCK();
1271
1272 td->td_retval[0] = 0;
1273 return (0);
1274 }
1275
1276 int
1277 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1278 {
1279 linker_file_t lf;
1280 module_t mp;
1281 int error = 0;
1282
1283 #ifdef MAC
1284 error = mac_kld_check_stat(td->td_ucred);
1285 if (error)
1286 return (error);
1287 #endif
1288
1289 KLD_LOCK();
1290 lf = linker_find_file_by_id(uap->fileid);
1291 if (lf) {
1292 MOD_SLOCK;
1293 mp = TAILQ_FIRST(&lf->modules);
1294 if (mp != NULL)
1295 td->td_retval[0] = module_getid(mp);
1296 else
1297 td->td_retval[0] = 0;
1298 MOD_SUNLOCK;
1299 } else
1300 error = ENOENT;
1301 KLD_UNLOCK();
1302 return (error);
1303 }
1304
1305 int
1306 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1307 {
1308 char *symstr = NULL;
1309 c_linker_sym_t sym;
1310 linker_symval_t symval;
1311 linker_file_t lf;
1312 struct kld_sym_lookup lookup;
1313 int error = 0;
1314
1315 #ifdef MAC
1316 error = mac_kld_check_stat(td->td_ucred);
1317 if (error)
1318 return (error);
1319 #endif
1320
1321 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1322 return (error);
1323 if (lookup.version != sizeof(lookup) ||
1324 uap->cmd != KLDSYM_LOOKUP)
1325 return (EINVAL);
1326 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1327 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1328 goto out;
1329 KLD_LOCK();
1330 if (uap->fileid != 0) {
1331 lf = linker_find_file_by_id(uap->fileid);
1332 if (lf == NULL)
1333 error = ENOENT;
1334 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1335 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1336 lookup.symvalue = (uintptr_t) symval.value;
1337 lookup.symsize = symval.size;
1338 error = copyout(&lookup, uap->data, sizeof(lookup));
1339 } else
1340 error = ENOENT;
1341 } else {
1342 TAILQ_FOREACH(lf, &linker_files, link) {
1343 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1344 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1345 lookup.symvalue = (uintptr_t)symval.value;
1346 lookup.symsize = symval.size;
1347 error = copyout(&lookup, uap->data,
1348 sizeof(lookup));
1349 break;
1350 }
1351 }
1352 if (lf == NULL)
1353 error = ENOENT;
1354 }
1355 KLD_UNLOCK();
1356 out:
1357 free(symstr, M_TEMP);
1358 return (error);
1359 }
1360
1361 /*
1362 * Preloaded module support
1363 */
1364
1365 static modlist_t
1366 modlist_lookup(const char *name, int ver)
1367 {
1368 modlist_t mod;
1369
1370 TAILQ_FOREACH(mod, &found_modules, link) {
1371 if (strcmp(mod->name, name) == 0 &&
1372 (ver == 0 || mod->version == ver))
1373 return (mod);
1374 }
1375 return (NULL);
1376 }
1377
1378 static modlist_t
1379 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1380 {
1381 modlist_t mod, bestmod;
1382 int ver;
1383
1384 if (verinfo == NULL)
1385 return (modlist_lookup(name, 0));
1386 bestmod = NULL;
1387 TAILQ_FOREACH(mod, &found_modules, link) {
1388 if (strcmp(mod->name, name) != 0)
1389 continue;
1390 ver = mod->version;
1391 if (ver == verinfo->md_ver_preferred)
1392 return (mod);
1393 if (ver >= verinfo->md_ver_minimum &&
1394 ver <= verinfo->md_ver_maximum &&
1395 (bestmod == NULL || ver > bestmod->version))
1396 bestmod = mod;
1397 }
1398 return (bestmod);
1399 }
1400
1401 static modlist_t
1402 modlist_newmodule(const char *modname, int version, linker_file_t container)
1403 {
1404 modlist_t mod;
1405
1406 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1407 if (mod == NULL)
1408 panic("no memory for module list");
1409 mod->container = container;
1410 mod->name = modname;
1411 mod->version = version;
1412 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1413 return (mod);
1414 }
1415
1416 static void
1417 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1418 struct mod_metadata **stop, int preload)
1419 {
1420 struct mod_metadata *mp, **mdp;
1421 const char *modname;
1422 int ver;
1423
1424 for (mdp = start; mdp < stop; mdp++) {
1425 mp = *mdp;
1426 if (mp->md_type != MDT_VERSION)
1427 continue;
1428 modname = mp->md_cval;
1429 ver = ((struct mod_version *)mp->md_data)->mv_version;
1430 if (modlist_lookup(modname, ver) != NULL) {
1431 printf("module %s already present!\n", modname);
1432 /* XXX what can we do? this is a build error. :-( */
1433 continue;
1434 }
1435 modlist_newmodule(modname, ver, lf);
1436 }
1437 }
1438
1439 static void
1440 linker_preload(void *arg)
1441 {
1442 caddr_t modptr;
1443 const char *modname, *nmodname;
1444 char *modtype;
1445 linker_file_t lf, nlf;
1446 linker_class_t lc;
1447 int error;
1448 linker_file_list_t loaded_files;
1449 linker_file_list_t depended_files;
1450 struct mod_metadata *mp, *nmp;
1451 struct mod_metadata **start, **stop, **mdp, **nmdp;
1452 struct mod_depend *verinfo;
1453 int nver;
1454 int resolves;
1455 modlist_t mod;
1456 struct sysinit **si_start, **si_stop;
1457
1458 TAILQ_INIT(&loaded_files);
1459 TAILQ_INIT(&depended_files);
1460 TAILQ_INIT(&found_modules);
1461 error = 0;
1462
1463 modptr = NULL;
1464 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1465 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1466 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1467 if (modname == NULL) {
1468 printf("Preloaded module at %p does not have a"
1469 " name!\n", modptr);
1470 continue;
1471 }
1472 if (modtype == NULL) {
1473 printf("Preloaded module at %p does not have a type!\n",
1474 modptr);
1475 continue;
1476 }
1477 if (bootverbose)
1478 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1479 modptr);
1480 lf = NULL;
1481 TAILQ_FOREACH(lc, &classes, link) {
1482 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1483 if (!error)
1484 break;
1485 lf = NULL;
1486 }
1487 if (lf)
1488 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1489 }
1490
1491 /*
1492 * First get a list of stuff in the kernel.
1493 */
1494 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1495 &stop, NULL) == 0)
1496 linker_addmodules(linker_kernel_file, start, stop, 1);
1497
1498 /*
1499 * This is a once-off kinky bubble sort to resolve relocation
1500 * dependency requirements.
1501 */
1502 restart:
1503 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1504 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1505 &stop, NULL);
1506 /*
1507 * First, look to see if we would successfully link with this
1508 * stuff.
1509 */
1510 resolves = 1; /* unless we know otherwise */
1511 if (!error) {
1512 for (mdp = start; mdp < stop; mdp++) {
1513 mp = *mdp;
1514 if (mp->md_type != MDT_DEPEND)
1515 continue;
1516 modname = mp->md_cval;
1517 verinfo = mp->md_data;
1518 for (nmdp = start; nmdp < stop; nmdp++) {
1519 nmp = *nmdp;
1520 if (nmp->md_type != MDT_VERSION)
1521 continue;
1522 nmodname = nmp->md_cval;
1523 if (strcmp(modname, nmodname) == 0)
1524 break;
1525 }
1526 if (nmdp < stop) /* it's a self reference */
1527 continue;
1528
1529 /*
1530 * ok, the module isn't here yet, we
1531 * are not finished
1532 */
1533 if (modlist_lookup2(modname, verinfo) == NULL)
1534 resolves = 0;
1535 }
1536 }
1537 /*
1538 * OK, if we found our modules, we can link. So, "provide"
1539 * the modules inside and add it to the end of the link order
1540 * list.
1541 */
1542 if (resolves) {
1543 if (!error) {
1544 for (mdp = start; mdp < stop; mdp++) {
1545 mp = *mdp;
1546 if (mp->md_type != MDT_VERSION)
1547 continue;
1548 modname = mp->md_cval;
1549 nver = ((struct mod_version *)
1550 mp->md_data)->mv_version;
1551 if (modlist_lookup(modname,
1552 nver) != NULL) {
1553 printf("module %s already"
1554 " present!\n", modname);
1555 TAILQ_REMOVE(&loaded_files,
1556 lf, loaded);
1557 linker_file_unload(lf,
1558 LINKER_UNLOAD_FORCE);
1559 /* we changed tailq next ptr */
1560 goto restart;
1561 }
1562 modlist_newmodule(modname, nver, lf);
1563 }
1564 }
1565 TAILQ_REMOVE(&loaded_files, lf, loaded);
1566 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1567 /*
1568 * Since we provided modules, we need to restart the
1569 * sort so that the previous files that depend on us
1570 * have a chance. Also, we've busted the tailq next
1571 * pointer with the REMOVE.
1572 */
1573 goto restart;
1574 }
1575 }
1576
1577 /*
1578 * At this point, we check to see what could not be resolved..
1579 */
1580 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1581 TAILQ_REMOVE(&loaded_files, lf, loaded);
1582 printf("KLD file %s is missing dependencies\n", lf->filename);
1583 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1584 }
1585
1586 /*
1587 * We made it. Finish off the linking in the order we determined.
1588 */
1589 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1590 if (linker_kernel_file) {
1591 linker_kernel_file->refs++;
1592 error = linker_file_add_dependency(lf,
1593 linker_kernel_file);
1594 if (error)
1595 panic("cannot add dependency");
1596 }
1597 lf->userrefs++; /* so we can (try to) kldunload it */
1598 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1599 &stop, NULL);
1600 if (!error) {
1601 for (mdp = start; mdp < stop; mdp++) {
1602 mp = *mdp;
1603 if (mp->md_type != MDT_DEPEND)
1604 continue;
1605 modname = mp->md_cval;
1606 verinfo = mp->md_data;
1607 mod = modlist_lookup2(modname, verinfo);
1608 if (mod == NULL) {
1609 printf("KLD file %s - cannot find "
1610 "dependency \"%s\"\n",
1611 lf->filename, modname);
1612 goto fail;
1613 }
1614 /* Don't count self-dependencies */
1615 if (lf == mod->container)
1616 continue;
1617 mod->container->refs++;
1618 error = linker_file_add_dependency(lf,
1619 mod->container);
1620 if (error)
1621 panic("cannot add dependency");
1622 }
1623 }
1624 /*
1625 * Now do relocation etc using the symbol search paths
1626 * established by the dependencies
1627 */
1628 error = LINKER_LINK_PRELOAD_FINISH(lf);
1629 if (error) {
1630 printf("KLD file %s - could not finalize loading\n",
1631 lf->filename);
1632 goto fail;
1633 }
1634 linker_file_register_modules(lf);
1635 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1636 &si_stop, NULL) == 0)
1637 sysinit_add(si_start, si_stop);
1638 linker_file_register_sysctls(lf);
1639 lf->flags |= LINKER_FILE_LINKED;
1640 continue;
1641 fail:
1642 TAILQ_REMOVE(&depended_files, lf, loaded);
1643 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1644 }
1645 /* woohoo! we made it! */
1646 }
1647
1648 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1649
1650 /*
1651 * Search for a not-loaded module by name.
1652 *
1653 * Modules may be found in the following locations:
1654 *
1655 * - preloaded (result is just the module name) - on disk (result is full path
1656 * to module)
1657 *
1658 * If the module name is qualified in any way (contains path, etc.) the we
1659 * simply return a copy of it.
1660 *
1661 * The search path can be manipulated via sysctl. Note that we use the ';'
1662 * character as a separator to be consistent with the bootloader.
1663 */
1664
1665 static char linker_hintfile[] = "linker.hints";
1666 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1667
1668 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1669 sizeof(linker_path), "module load search path");
1670
1671 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1672
1673 static char *linker_ext_list[] = {
1674 "",
1675 ".ko",
1676 NULL
1677 };
1678
1679 /*
1680 * Check if file actually exists either with or without extension listed in
1681 * the linker_ext_list. (probably should be generic for the rest of the
1682 * kernel)
1683 */
1684 static char *
1685 linker_lookup_file(const char *path, int pathlen, const char *name,
1686 int namelen, struct vattr *vap)
1687 {
1688 struct nameidata nd;
1689 struct thread *td = curthread; /* XXX */
1690 char *result, **cpp, *sep;
1691 int error, len, extlen, reclen, flags, vfslocked;
1692 enum vtype type;
1693
1694 extlen = 0;
1695 for (cpp = linker_ext_list; *cpp; cpp++) {
1696 len = strlen(*cpp);
1697 if (len > extlen)
1698 extlen = len;
1699 }
1700 extlen++; /* trailing '\0' */
1701 sep = (path[pathlen - 1] != '/') ? "/" : "";
1702
1703 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1704 result = malloc(reclen, M_LINKER, M_WAITOK);
1705 for (cpp = linker_ext_list; *cpp; cpp++) {
1706 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1707 namelen, name, *cpp);
1708 /*
1709 * Attempt to open the file, and return the path if
1710 * we succeed and it's a regular file.
1711 */
1712 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
1713 flags = FREAD;
1714 error = vn_open(&nd, &flags, 0, NULL);
1715 if (error == 0) {
1716 vfslocked = NDHASGIANT(&nd);
1717 NDFREE(&nd, NDF_ONLY_PNBUF);
1718 type = nd.ni_vp->v_type;
1719 if (vap)
1720 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1721 VOP_UNLOCK(nd.ni_vp, 0);
1722 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1723 VFS_UNLOCK_GIANT(vfslocked);
1724 if (type == VREG)
1725 return (result);
1726 }
1727 }
1728 free(result, M_LINKER);
1729 return (NULL);
1730 }
1731
1732 #define INT_ALIGN(base, ptr) ptr = \
1733 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1734
1735 /*
1736 * Lookup KLD which contains requested module in the "linker.hints" file. If
1737 * version specification is available, then try to find the best KLD.
1738 * Otherwise just find the latest one.
1739 */
1740 static char *
1741 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1742 int modnamelen, struct mod_depend *verinfo)
1743 {
1744 struct thread *td = curthread; /* XXX */
1745 struct ucred *cred = td ? td->td_ucred : NULL;
1746 struct nameidata nd;
1747 struct vattr vattr, mattr;
1748 u_char *hints = NULL;
1749 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1750 int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
1751 int vfslocked = 0;
1752
1753 result = NULL;
1754 bestver = found = 0;
1755
1756 sep = (path[pathlen - 1] != '/') ? "/" : "";
1757 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1758 strlen(sep) + 1;
1759 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1760 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1761 linker_hintfile);
1762
1763 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
1764 flags = FREAD;
1765 error = vn_open(&nd, &flags, 0, NULL);
1766 if (error)
1767 goto bad;
1768 vfslocked = NDHASGIANT(&nd);
1769 NDFREE(&nd, NDF_ONLY_PNBUF);
1770 if (nd.ni_vp->v_type != VREG)
1771 goto bad;
1772 best = cp = NULL;
1773 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1774 if (error)
1775 goto bad;
1776 /*
1777 * XXX: we need to limit this number to some reasonable value
1778 */
1779 if (vattr.va_size > 100 * 1024) {
1780 printf("hints file too large %ld\n", (long)vattr.va_size);
1781 goto bad;
1782 }
1783 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1784 if (hints == NULL)
1785 goto bad;
1786 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1787 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1788 if (error)
1789 goto bad;
1790 VOP_UNLOCK(nd.ni_vp, 0);
1791 vn_close(nd.ni_vp, FREAD, cred, td);
1792 VFS_UNLOCK_GIANT(vfslocked);
1793 nd.ni_vp = NULL;
1794 if (reclen != 0) {
1795 printf("can't read %d\n", reclen);
1796 goto bad;
1797 }
1798 intp = (int *)hints;
1799 ival = *intp++;
1800 if (ival != LINKER_HINTS_VERSION) {
1801 printf("hints file version mismatch %d\n", ival);
1802 goto bad;
1803 }
1804 bufend = hints + vattr.va_size;
1805 recptr = (u_char *)intp;
1806 clen = blen = 0;
1807 while (recptr < bufend && !found) {
1808 intp = (int *)recptr;
1809 reclen = *intp++;
1810 ival = *intp++;
1811 cp = (char *)intp;
1812 switch (ival) {
1813 case MDT_VERSION:
1814 clen = *cp++;
1815 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1816 break;
1817 cp += clen;
1818 INT_ALIGN(hints, cp);
1819 ival = *(int *)cp;
1820 cp += sizeof(int);
1821 clen = *cp++;
1822 if (verinfo == NULL ||
1823 ival == verinfo->md_ver_preferred) {
1824 found = 1;
1825 break;
1826 }
1827 if (ival >= verinfo->md_ver_minimum &&
1828 ival <= verinfo->md_ver_maximum &&
1829 ival > bestver) {
1830 bestver = ival;
1831 best = cp;
1832 blen = clen;
1833 }
1834 break;
1835 default:
1836 break;
1837 }
1838 recptr += reclen + sizeof(int);
1839 }
1840 /*
1841 * Finally check if KLD is in the place
1842 */
1843 if (found)
1844 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1845 else if (best)
1846 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1847
1848 /*
1849 * KLD is newer than hints file. What we should do now?
1850 */
1851 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1852 printf("warning: KLD '%s' is newer than the linker.hints"
1853 " file\n", result);
1854 bad:
1855 free(pathbuf, M_LINKER);
1856 if (hints)
1857 free(hints, M_TEMP);
1858 if (nd.ni_vp != NULL) {
1859 VOP_UNLOCK(nd.ni_vp, 0);
1860 vn_close(nd.ni_vp, FREAD, cred, td);
1861 VFS_UNLOCK_GIANT(vfslocked);
1862 }
1863 /*
1864 * If nothing found or hints is absent - fallback to the old
1865 * way by using "kldname[.ko]" as module name.
1866 */
1867 if (!found && !bestver && result == NULL)
1868 result = linker_lookup_file(path, pathlen, modname,
1869 modnamelen, NULL);
1870 return (result);
1871 }
1872
1873 /*
1874 * Lookup KLD which contains requested module in the all directories.
1875 */
1876 static char *
1877 linker_search_module(const char *modname, int modnamelen,
1878 struct mod_depend *verinfo)
1879 {
1880 char *cp, *ep, *result;
1881
1882 /*
1883 * traverse the linker path
1884 */
1885 for (cp = linker_path; *cp; cp = ep + 1) {
1886 /* find the end of this component */
1887 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1888 result = linker_hints_lookup(cp, ep - cp, modname,
1889 modnamelen, verinfo);
1890 if (result != NULL)
1891 return (result);
1892 if (*ep == 0)
1893 break;
1894 }
1895 return (NULL);
1896 }
1897
1898 /*
1899 * Search for module in all directories listed in the linker_path.
1900 */
1901 static char *
1902 linker_search_kld(const char *name)
1903 {
1904 char *cp, *ep, *result;
1905 int len;
1906
1907 /* qualified at all? */
1908 if (index(name, '/'))
1909 return (linker_strdup(name));
1910
1911 /* traverse the linker path */
1912 len = strlen(name);
1913 for (ep = linker_path; *ep; ep++) {
1914 cp = ep;
1915 /* find the end of this component */
1916 for (; *ep != 0 && *ep != ';'; ep++);
1917 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1918 if (result != NULL)
1919 return (result);
1920 }
1921 return (NULL);
1922 }
1923
1924 static const char *
1925 linker_basename(const char *path)
1926 {
1927 const char *filename;
1928
1929 filename = rindex(path, '/');
1930 if (filename == NULL)
1931 return path;
1932 if (filename[1])
1933 filename++;
1934 return (filename);
1935 }
1936
1937 #ifdef HWPMC_HOOKS
1938 /*
1939 * Inform hwpmc about the set of kernel modules currently loaded.
1940 */
1941 void *
1942 linker_hwpmc_list_objects(void)
1943 {
1944 linker_file_t lf;
1945 struct pmckern_map_in *kobase;
1946 int i, nmappings;
1947
1948 nmappings = 0;
1949 KLD_LOCK_READ();
1950 TAILQ_FOREACH(lf, &linker_files, link)
1951 nmappings++;
1952
1953 /* Allocate nmappings + 1 entries. */
1954 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1955 M_LINKER, M_WAITOK | M_ZERO);
1956 i = 0;
1957 TAILQ_FOREACH(lf, &linker_files, link) {
1958
1959 /* Save the info for this linker file. */
1960 kobase[i].pm_file = lf->filename;
1961 kobase[i].pm_address = (uintptr_t)lf->address;
1962 i++;
1963 }
1964 KLD_UNLOCK_READ();
1965
1966 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1967
1968 /* The last entry of the malloced area comprises of all zeros. */
1969 KASSERT(kobase[i].pm_file == NULL,
1970 ("linker_hwpmc_list_objects: last object not NULL"));
1971
1972 return ((void *)kobase);
1973 }
1974 #endif
1975
1976 /*
1977 * Find a file which contains given module and load it, if "parent" is not
1978 * NULL, register a reference to it.
1979 */
1980 static int
1981 linker_load_module(const char *kldname, const char *modname,
1982 struct linker_file *parent, struct mod_depend *verinfo,
1983 struct linker_file **lfpp)
1984 {
1985 linker_file_t lfdep;
1986 const char *filename;
1987 char *pathname;
1988 int error;
1989
1990 KLD_LOCK_ASSERT();
1991 if (modname == NULL) {
1992 /*
1993 * We have to load KLD
1994 */
1995 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1996 " is not NULL"));
1997 pathname = linker_search_kld(kldname);
1998 } else {
1999 if (modlist_lookup2(modname, verinfo) != NULL)
2000 return (EEXIST);
2001 if (kldname != NULL)
2002 pathname = linker_strdup(kldname);
2003 else if (rootvnode == NULL)
2004 pathname = NULL;
2005 else
2006 /*
2007 * Need to find a KLD with required module
2008 */
2009 pathname = linker_search_module(modname,
2010 strlen(modname), verinfo);
2011 }
2012 if (pathname == NULL)
2013 return (ENOENT);
2014
2015 /*
2016 * Can't load more than one file with the same basename XXX:
2017 * Actually it should be possible to have multiple KLDs with
2018 * the same basename but different path because they can
2019 * provide different versions of the same modules.
2020 */
2021 filename = linker_basename(pathname);
2022 if (linker_find_file_by_name(filename))
2023 error = EEXIST;
2024 else do {
2025 error = linker_load_file(pathname, &lfdep);
2026 if (error)
2027 break;
2028 if (modname && verinfo &&
2029 modlist_lookup2(modname, verinfo) == NULL) {
2030 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2031 error = ENOENT;
2032 break;
2033 }
2034 if (parent) {
2035 error = linker_file_add_dependency(parent, lfdep);
2036 if (error)
2037 break;
2038 }
2039 if (lfpp)
2040 *lfpp = lfdep;
2041 } while (0);
2042 free(pathname, M_LINKER);
2043 return (error);
2044 }
2045
2046 /*
2047 * This routine is responsible for finding dependencies of userland initiated
2048 * kldload(2)'s of files.
2049 */
2050 int
2051 linker_load_dependencies(linker_file_t lf)
2052 {
2053 linker_file_t lfdep;
2054 struct mod_metadata **start, **stop, **mdp, **nmdp;
2055 struct mod_metadata *mp, *nmp;
2056 struct mod_depend *verinfo;
2057 modlist_t mod;
2058 const char *modname, *nmodname;
2059 int ver, error = 0, count;
2060
2061 /*
2062 * All files are dependant on /kernel.
2063 */
2064 KLD_LOCK_ASSERT();
2065 if (linker_kernel_file) {
2066 linker_kernel_file->refs++;
2067 error = linker_file_add_dependency(lf, linker_kernel_file);
2068 if (error)
2069 return (error);
2070 }
2071 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2072 &count) != 0)
2073 return (0);
2074 for (mdp = start; mdp < stop; mdp++) {
2075 mp = *mdp;
2076 if (mp->md_type != MDT_VERSION)
2077 continue;
2078 modname = mp->md_cval;
2079 ver = ((struct mod_version *)mp->md_data)->mv_version;
2080 mod = modlist_lookup(modname, ver);
2081 if (mod != NULL) {
2082 printf("interface %s.%d already present in the KLD"
2083 " '%s'!\n", modname, ver,
2084 mod->container->filename);
2085 return (EEXIST);
2086 }
2087 }
2088
2089 for (mdp = start; mdp < stop; mdp++) {
2090 mp = *mdp;
2091 if (mp->md_type != MDT_DEPEND)
2092 continue;
2093 modname = mp->md_cval;
2094 verinfo = mp->md_data;
2095 nmodname = NULL;
2096 for (nmdp = start; nmdp < stop; nmdp++) {
2097 nmp = *nmdp;
2098 if (nmp->md_type != MDT_VERSION)
2099 continue;
2100 nmodname = nmp->md_cval;
2101 if (strcmp(modname, nmodname) == 0)
2102 break;
2103 }
2104 if (nmdp < stop)/* early exit, it's a self reference */
2105 continue;
2106 mod = modlist_lookup2(modname, verinfo);
2107 if (mod) { /* woohoo, it's loaded already */
2108 lfdep = mod->container;
2109 lfdep->refs++;
2110 error = linker_file_add_dependency(lf, lfdep);
2111 if (error)
2112 break;
2113 continue;
2114 }
2115 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2116 if (error) {
2117 printf("KLD %s: depends on %s - not available or"
2118 " version mismatch\n", lf->filename, modname);
2119 break;
2120 }
2121 }
2122
2123 if (error)
2124 return (error);
2125 linker_addmodules(lf, start, stop, 0);
2126 return (error);
2127 }
2128
2129 static int
2130 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2131 {
2132 struct sysctl_req *req;
2133
2134 req = opaque;
2135 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2136 }
2137
2138 /*
2139 * Export a nul-separated, double-nul-terminated list of all function names
2140 * in the kernel.
2141 */
2142 static int
2143 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2144 {
2145 linker_file_t lf;
2146 int error;
2147
2148 #ifdef MAC
2149 error = mac_kld_check_stat(req->td->td_ucred);
2150 if (error)
2151 return (error);
2152 #endif
2153 error = sysctl_wire_old_buffer(req, 0);
2154 if (error != 0)
2155 return (error);
2156 KLD_LOCK();
2157 TAILQ_FOREACH(lf, &linker_files, link) {
2158 error = LINKER_EACH_FUNCTION_NAME(lf,
2159 sysctl_kern_function_list_iterate, req);
2160 if (error) {
2161 KLD_UNLOCK();
2162 return (error);
2163 }
2164 }
2165 KLD_UNLOCK();
2166 return (SYSCTL_OUT(req, "", 1));
2167 }
2168
2169 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2170 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: 5bc5e29d833607486f086160f5835775
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