1 /*-
2 * Copyright (c) 1997-2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.4/sys/kern/kern_linker.c 325877 2017-11-15 22:50:47Z gordon $");
29
30 #include "opt_ddb.h"
31 #include "opt_kld.h"
32 #include "opt_hwpmc_hooks.h"
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/sysproto.h>
39 #include <sys/sysent.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/sx.h>
45 #include <sys/module.h>
46 #include <sys/mount.h>
47 #include <sys/linker.h>
48 #include <sys/eventhandler.h>
49 #include <sys/fcntl.h>
50 #include <sys/jail.h>
51 #include <sys/libkern.h>
52 #include <sys/namei.h>
53 #include <sys/vnode.h>
54 #include <sys/syscallsubr.h>
55 #include <sys/sysctl.h>
56
57 #include <net/vnet.h>
58
59 #include <security/mac/mac_framework.h>
60
61 #include "linker_if.h"
62
63 #ifdef HWPMC_HOOKS
64 #include <sys/pmckern.h>
65 #endif
66
67 #ifdef KLD_DEBUG
68 int kld_debug = 0;
69 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW | CTLFLAG_TUN,
70 &kld_debug, 0, "Set various levels of KLD debug");
71 TUNABLE_INT("debug.kld_debug", &kld_debug);
72 #endif
73
74 /* These variables are used by kernel debuggers to enumerate loaded files. */
75 const int kld_off_address = offsetof(struct linker_file, address);
76 const int kld_off_filename = offsetof(struct linker_file, filename);
77 const int kld_off_pathname = offsetof(struct linker_file, pathname);
78 const int kld_off_next = offsetof(struct linker_file, link.tqe_next);
79
80 /*
81 * static char *linker_search_path(const char *name, struct mod_depend
82 * *verinfo);
83 */
84 static const char *linker_basename(const char *path);
85
86 /*
87 * Find a currently loaded file given its filename.
88 */
89 static linker_file_t linker_find_file_by_name(const char* _filename);
90
91 /*
92 * Find a currently loaded file given its file id.
93 */
94 static linker_file_t linker_find_file_by_id(int _fileid);
95
96 /* Metadata from the static kernel */
97 SET_DECLARE(modmetadata_set, struct mod_metadata);
98
99 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
100
101 linker_file_t linker_kernel_file;
102
103 static struct sx kld_sx; /* kernel linker lock */
104
105 /*
106 * Load counter used by clients to determine if a linker file has been
107 * re-loaded. This counter is incremented for each file load.
108 */
109 static int loadcnt;
110
111 static linker_class_list_t classes;
112 static linker_file_list_t linker_files;
113 static int next_file_id = 1;
114 static int linker_no_more_classes = 0;
115
116 #define LINKER_GET_NEXT_FILE_ID(a) do { \
117 linker_file_t lftmp; \
118 \
119 if (!cold) \
120 sx_assert(&kld_sx, SA_XLOCKED); \
121 retry: \
122 TAILQ_FOREACH(lftmp, &linker_files, link) { \
123 if (next_file_id == lftmp->id) { \
124 next_file_id++; \
125 goto retry; \
126 } \
127 } \
128 (a) = next_file_id; \
129 } while(0)
130
131
132 /* XXX wrong name; we're looking at version provision tags here, not modules */
133 typedef TAILQ_HEAD(, modlist) modlisthead_t;
134 struct modlist {
135 TAILQ_ENTRY(modlist) link; /* chain together all modules */
136 linker_file_t container;
137 const char *name;
138 int version;
139 };
140 typedef struct modlist *modlist_t;
141 static modlisthead_t found_modules;
142
143 static int linker_file_add_dependency(linker_file_t file,
144 linker_file_t dep);
145 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
146 const char* name, int deps);
147 static int linker_load_module(const char *kldname,
148 const char *modname, struct linker_file *parent,
149 struct mod_depend *verinfo, struct linker_file **lfpp);
150 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
151
152 static void
153 linker_init(void *arg)
154 {
155
156 sx_init(&kld_sx, "kernel linker");
157 TAILQ_INIT(&classes);
158 TAILQ_INIT(&linker_files);
159 }
160
161 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
162
163 static void
164 linker_stop_class_add(void *arg)
165 {
166
167 linker_no_more_classes = 1;
168 }
169
170 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
171
172 int
173 linker_add_class(linker_class_t lc)
174 {
175
176 /*
177 * We disallow any class registration past SI_ORDER_ANY
178 * of SI_SUB_KLD. We bump the reference count to keep the
179 * ops from being freed.
180 */
181 if (linker_no_more_classes == 1)
182 return (EPERM);
183 kobj_class_compile((kobj_class_t) lc);
184 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */
185 TAILQ_INSERT_TAIL(&classes, lc, link);
186 return (0);
187 }
188
189 static void
190 linker_file_sysinit(linker_file_t lf)
191 {
192 struct sysinit **start, **stop, **sipp, **xipp, *save;
193
194 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
195 lf->filename));
196
197 sx_assert(&kld_sx, SA_XLOCKED);
198
199 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
200 return;
201 /*
202 * Perform a bubble sort of the system initialization objects by
203 * their subsystem (primary key) and order (secondary key).
204 *
205 * Since some things care about execution order, this is the operation
206 * which ensures continued function.
207 */
208 for (sipp = start; sipp < stop; sipp++) {
209 for (xipp = sipp + 1; xipp < stop; xipp++) {
210 if ((*sipp)->subsystem < (*xipp)->subsystem ||
211 ((*sipp)->subsystem == (*xipp)->subsystem &&
212 (*sipp)->order <= (*xipp)->order))
213 continue; /* skip */
214 save = *sipp;
215 *sipp = *xipp;
216 *xipp = save;
217 }
218 }
219
220 /*
221 * Traverse the (now) ordered list of system initialization tasks.
222 * Perform each task, and continue on to the next task.
223 */
224 sx_xunlock(&kld_sx);
225 mtx_lock(&Giant);
226 for (sipp = start; sipp < stop; sipp++) {
227 if ((*sipp)->subsystem == SI_SUB_DUMMY)
228 continue; /* skip dummy task(s) */
229
230 /* Call function */
231 (*((*sipp)->func)) ((*sipp)->udata);
232 }
233 mtx_unlock(&Giant);
234 sx_xlock(&kld_sx);
235 }
236
237 static void
238 linker_file_sysuninit(linker_file_t lf)
239 {
240 struct sysinit **start, **stop, **sipp, **xipp, *save;
241
242 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
243 lf->filename));
244
245 sx_assert(&kld_sx, SA_XLOCKED);
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 sx_xunlock(&kld_sx);
275 mtx_lock(&Giant);
276 for (sipp = start; sipp < stop; sipp++) {
277 if ((*sipp)->subsystem == SI_SUB_DUMMY)
278 continue; /* skip dummy task(s) */
279
280 /* Call function */
281 (*((*sipp)->func)) ((*sipp)->udata);
282 }
283 mtx_unlock(&Giant);
284 sx_xlock(&kld_sx);
285 }
286
287 static void
288 linker_file_register_sysctls(linker_file_t lf)
289 {
290 struct sysctl_oid **start, **stop, **oidp;
291
292 KLD_DPF(FILE,
293 ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
294 lf->filename));
295
296 sx_assert(&kld_sx, SA_XLOCKED);
297
298 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
299 return;
300
301 sx_xunlock(&kld_sx);
302 sysctl_lock();
303 for (oidp = start; oidp < stop; oidp++)
304 sysctl_register_oid(*oidp);
305 sysctl_unlock();
306 sx_xlock(&kld_sx);
307 }
308
309 static void
310 linker_file_unregister_sysctls(linker_file_t lf)
311 {
312 struct sysctl_oid **start, **stop, **oidp;
313
314 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
315 " for %s\n", lf->filename));
316
317 sx_assert(&kld_sx, SA_XLOCKED);
318
319 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
320 return;
321
322 sx_xunlock(&kld_sx);
323 sysctl_lock();
324 for (oidp = start; oidp < stop; oidp++)
325 sysctl_unregister_oid(*oidp);
326 sysctl_unlock();
327 sx_xlock(&kld_sx);
328 }
329
330 static int
331 linker_file_register_modules(linker_file_t lf)
332 {
333 struct mod_metadata **start, **stop, **mdp;
334 const moduledata_t *moddata;
335 int first_error, error;
336
337 KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
338 " in %s\n", lf->filename));
339
340 sx_assert(&kld_sx, SA_XLOCKED);
341
342 if (linker_file_lookup_set(lf, "modmetadata_set", &start,
343 &stop, NULL) != 0) {
344 /*
345 * This fallback should be unnecessary, but if we get booted
346 * from boot2 instead of loader and we are missing our
347 * metadata then we have to try the best we can.
348 */
349 if (lf == linker_kernel_file) {
350 start = SET_BEGIN(modmetadata_set);
351 stop = SET_LIMIT(modmetadata_set);
352 } else
353 return (0);
354 }
355 first_error = 0;
356 for (mdp = start; mdp < stop; mdp++) {
357 if ((*mdp)->md_type != MDT_MODULE)
358 continue;
359 moddata = (*mdp)->md_data;
360 KLD_DPF(FILE, ("Registering module %s in %s\n",
361 moddata->name, lf->filename));
362 error = module_register(moddata, lf);
363 if (error) {
364 printf("Module %s failed to register: %d\n",
365 moddata->name, error);
366 if (first_error == 0)
367 first_error = error;
368 }
369 }
370 return (first_error);
371 }
372
373 static void
374 linker_init_kernel_modules(void)
375 {
376
377 sx_xlock(&kld_sx);
378 linker_file_register_modules(linker_kernel_file);
379 sx_xunlock(&kld_sx);
380 }
381
382 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
383 0);
384
385 static int
386 linker_load_file(const char *filename, linker_file_t *result)
387 {
388 linker_class_t lc;
389 linker_file_t lf;
390 int foundfile, error, modules;
391
392 /* Refuse to load modules if securelevel raised */
393 if (prison0.pr_securelevel > 0)
394 return (EPERM);
395
396 sx_assert(&kld_sx, SA_XLOCKED);
397 lf = linker_find_file_by_name(filename);
398 if (lf) {
399 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
400 " incrementing refs\n", filename));
401 *result = lf;
402 lf->refs++;
403 return (0);
404 }
405 foundfile = 0;
406 error = 0;
407
408 /*
409 * We do not need to protect (lock) classes here because there is
410 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
411 * and there is no class deregistration mechanism at this time.
412 */
413 TAILQ_FOREACH(lc, &classes, link) {
414 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
415 filename));
416 error = LINKER_LOAD_FILE(lc, filename, &lf);
417 /*
418 * If we got something other than ENOENT, then it exists but
419 * we cannot load it for some other reason.
420 */
421 if (error != ENOENT)
422 foundfile = 1;
423 if (lf) {
424 error = linker_file_register_modules(lf);
425 if (error == EEXIST) {
426 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
427 return (error);
428 }
429 modules = !TAILQ_EMPTY(&lf->modules);
430 linker_file_register_sysctls(lf);
431 linker_file_sysinit(lf);
432 lf->flags |= LINKER_FILE_LINKED;
433
434 /*
435 * If all of the modules in this file failed
436 * to load, unload the file and return an
437 * error of ENOEXEC.
438 */
439 if (modules && TAILQ_EMPTY(&lf->modules)) {
440 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
441 return (ENOEXEC);
442 }
443 EVENTHANDLER_INVOKE(kld_load, lf);
444 *result = lf;
445 return (0);
446 }
447 }
448 /*
449 * Less than ideal, but tells the user whether it failed to load or
450 * the module was not found.
451 */
452 if (foundfile) {
453
454 /*
455 * If the file type has not been recognized by the last try
456 * printout a message before to fail.
457 */
458 if (error == ENOSYS)
459 printf("linker_load_file: Unsupported file type\n");
460
461 /*
462 * Format not recognized or otherwise unloadable.
463 * When loading a module that is statically built into
464 * the kernel EEXIST percolates back up as the return
465 * value. Preserve this so that apps like sysinstall
466 * can recognize this special case and not post bogus
467 * dialog boxes.
468 */
469 if (error != EEXIST)
470 error = ENOEXEC;
471 } else
472 error = ENOENT; /* Nothing found */
473 return (error);
474 }
475
476 int
477 linker_reference_module(const char *modname, struct mod_depend *verinfo,
478 linker_file_t *result)
479 {
480 modlist_t mod;
481 int error;
482
483 sx_xlock(&kld_sx);
484 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
485 *result = mod->container;
486 (*result)->refs++;
487 sx_xunlock(&kld_sx);
488 return (0);
489 }
490
491 error = linker_load_module(NULL, modname, NULL, verinfo, result);
492 sx_xunlock(&kld_sx);
493 return (error);
494 }
495
496 int
497 linker_release_module(const char *modname, struct mod_depend *verinfo,
498 linker_file_t lf)
499 {
500 modlist_t mod;
501 int error;
502
503 sx_xlock(&kld_sx);
504 if (lf == NULL) {
505 KASSERT(modname != NULL,
506 ("linker_release_module: no file or name"));
507 mod = modlist_lookup2(modname, verinfo);
508 if (mod == NULL) {
509 sx_xunlock(&kld_sx);
510 return (ESRCH);
511 }
512 lf = mod->container;
513 } else
514 KASSERT(modname == NULL && verinfo == NULL,
515 ("linker_release_module: both file and name"));
516 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
517 sx_xunlock(&kld_sx);
518 return (error);
519 }
520
521 static linker_file_t
522 linker_find_file_by_name(const char *filename)
523 {
524 linker_file_t lf;
525 char *koname;
526
527 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
528 sprintf(koname, "%s.ko", filename);
529
530 sx_assert(&kld_sx, SA_XLOCKED);
531 TAILQ_FOREACH(lf, &linker_files, link) {
532 if (strcmp(lf->filename, koname) == 0)
533 break;
534 if (strcmp(lf->filename, filename) == 0)
535 break;
536 }
537 free(koname, M_LINKER);
538 return (lf);
539 }
540
541 static linker_file_t
542 linker_find_file_by_id(int fileid)
543 {
544 linker_file_t lf;
545
546 sx_assert(&kld_sx, SA_XLOCKED);
547 TAILQ_FOREACH(lf, &linker_files, link)
548 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
549 break;
550 return (lf);
551 }
552
553 int
554 linker_file_foreach(linker_predicate_t *predicate, void *context)
555 {
556 linker_file_t lf;
557 int retval = 0;
558
559 sx_xlock(&kld_sx);
560 TAILQ_FOREACH(lf, &linker_files, link) {
561 retval = predicate(lf, context);
562 if (retval != 0)
563 break;
564 }
565 sx_xunlock(&kld_sx);
566 return (retval);
567 }
568
569 linker_file_t
570 linker_make_file(const char *pathname, linker_class_t lc)
571 {
572 linker_file_t lf;
573 const char *filename;
574
575 if (!cold)
576 sx_assert(&kld_sx, SA_XLOCKED);
577 filename = linker_basename(pathname);
578
579 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
580 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
581 if (lf == NULL)
582 return (NULL);
583 lf->refs = 1;
584 lf->userrefs = 0;
585 lf->flags = 0;
586 lf->filename = strdup(filename, M_LINKER);
587 lf->pathname = strdup(pathname, M_LINKER);
588 LINKER_GET_NEXT_FILE_ID(lf->id);
589 lf->ndeps = 0;
590 lf->deps = NULL;
591 lf->loadcnt = ++loadcnt;
592 STAILQ_INIT(&lf->common);
593 TAILQ_INIT(&lf->modules);
594 TAILQ_INSERT_TAIL(&linker_files, lf, link);
595 return (lf);
596 }
597
598 int
599 linker_file_unload(linker_file_t file, int flags)
600 {
601 module_t mod, next;
602 modlist_t ml, nextml;
603 struct common_symbol *cp;
604 int error, i;
605
606 /* Refuse to unload modules if securelevel raised. */
607 if (prison0.pr_securelevel > 0)
608 return (EPERM);
609
610 sx_assert(&kld_sx, SA_XLOCKED);
611 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
612
613 /* Easy case of just dropping a reference. */
614 if (file->refs > 1) {
615 file->refs--;
616 return (0);
617 }
618
619 /* Give eventhandlers a chance to prevent the unload. */
620 error = 0;
621 EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
622 if (error != 0)
623 return (EBUSY);
624
625 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
626 " informing modules\n"));
627
628 /*
629 * Quiesce all the modules to give them a chance to veto the unload.
630 */
631 MOD_SLOCK;
632 for (mod = TAILQ_FIRST(&file->modules); mod;
633 mod = module_getfnext(mod)) {
634
635 error = module_quiesce(mod);
636 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
637 KLD_DPF(FILE, ("linker_file_unload: module %s"
638 " vetoed unload\n", module_getname(mod)));
639 /*
640 * XXX: Do we need to tell all the quiesced modules
641 * that they can resume work now via a new module
642 * event?
643 */
644 MOD_SUNLOCK;
645 return (error);
646 }
647 }
648 MOD_SUNLOCK;
649
650 /*
651 * Inform any modules associated with this file that they are
652 * being unloaded.
653 */
654 MOD_XLOCK;
655 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
656 next = module_getfnext(mod);
657 MOD_XUNLOCK;
658
659 /*
660 * Give the module a chance to veto the unload.
661 */
662 if ((error = module_unload(mod)) != 0) {
663 #ifdef KLD_DEBUG
664 MOD_SLOCK;
665 KLD_DPF(FILE, ("linker_file_unload: module %s"
666 " failed unload\n", module_getname(mod)));
667 MOD_SUNLOCK;
668 #endif
669 return (error);
670 }
671 MOD_XLOCK;
672 module_release(mod);
673 }
674 MOD_XUNLOCK;
675
676 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
677 if (ml->container == file) {
678 TAILQ_REMOVE(&found_modules, ml, link);
679 free(ml, M_LINKER);
680 }
681 }
682
683 /*
684 * Don't try to run SYSUNINITs if we are unloaded due to a
685 * link error.
686 */
687 if (file->flags & LINKER_FILE_LINKED) {
688 file->flags &= ~LINKER_FILE_LINKED;
689 linker_file_sysuninit(file);
690 linker_file_unregister_sysctls(file);
691 }
692 TAILQ_REMOVE(&linker_files, file, link);
693
694 if (file->deps) {
695 for (i = 0; i < file->ndeps; i++)
696 linker_file_unload(file->deps[i], flags);
697 free(file->deps, M_LINKER);
698 file->deps = NULL;
699 }
700 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
701 STAILQ_REMOVE_HEAD(&file->common, link);
702 free(cp, M_LINKER);
703 }
704
705 LINKER_UNLOAD(file);
706
707 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
708 file->size);
709
710 if (file->filename) {
711 free(file->filename, M_LINKER);
712 file->filename = NULL;
713 }
714 if (file->pathname) {
715 free(file->pathname, M_LINKER);
716 file->pathname = NULL;
717 }
718 kobj_delete((kobj_t) file, M_LINKER);
719 return (0);
720 }
721
722 int
723 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
724 {
725 return (LINKER_CTF_GET(file, lc));
726 }
727
728 static int
729 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
730 {
731 linker_file_t *newdeps;
732
733 sx_assert(&kld_sx, SA_XLOCKED);
734 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
735 M_LINKER, M_WAITOK | M_ZERO);
736 file->deps[file->ndeps] = dep;
737 file->ndeps++;
738 KLD_DPF(FILE, ("linker_file_add_dependency:"
739 " adding %s as dependency for %s\n",
740 dep->filename, file->filename));
741 return (0);
742 }
743
744 /*
745 * Locate a linker set and its contents. This is a helper function to avoid
746 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
747 * This function is used in this file so we can avoid having lots of (void **)
748 * casts.
749 */
750 int
751 linker_file_lookup_set(linker_file_t file, const char *name,
752 void *firstp, void *lastp, int *countp)
753 {
754
755 sx_assert(&kld_sx, SA_LOCKED);
756 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
757 }
758
759 /*
760 * List all functions in a file.
761 */
762 int
763 linker_file_function_listall(linker_file_t lf,
764 linker_function_nameval_callback_t callback_func, void *arg)
765 {
766 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
767 }
768
769 caddr_t
770 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
771 {
772 caddr_t sym;
773 int locked;
774
775 locked = sx_xlocked(&kld_sx);
776 if (!locked)
777 sx_xlock(&kld_sx);
778 sym = linker_file_lookup_symbol_internal(file, name, deps);
779 if (!locked)
780 sx_xunlock(&kld_sx);
781 return (sym);
782 }
783
784 static caddr_t
785 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
786 int deps)
787 {
788 c_linker_sym_t sym;
789 linker_symval_t symval;
790 caddr_t address;
791 size_t common_size = 0;
792 int i;
793
794 sx_assert(&kld_sx, SA_XLOCKED);
795 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
796 file, name, deps));
797
798 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
799 LINKER_SYMBOL_VALUES(file, sym, &symval);
800 if (symval.value == 0)
801 /*
802 * For commons, first look them up in the
803 * dependencies and only allocate space if not found
804 * there.
805 */
806 common_size = symval.size;
807 else {
808 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
809 ".value=%p\n", symval.value));
810 return (symval.value);
811 }
812 }
813 if (deps) {
814 for (i = 0; i < file->ndeps; i++) {
815 address = linker_file_lookup_symbol_internal(
816 file->deps[i], name, 0);
817 if (address) {
818 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
819 " deps value=%p\n", address));
820 return (address);
821 }
822 }
823 }
824 if (common_size > 0) {
825 /*
826 * This is a common symbol which was not found in the
827 * dependencies. We maintain a simple common symbol table in
828 * the file object.
829 */
830 struct common_symbol *cp;
831
832 STAILQ_FOREACH(cp, &file->common, link) {
833 if (strcmp(cp->name, name) == 0) {
834 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
835 " old common value=%p\n", cp->address));
836 return (cp->address);
837 }
838 }
839 /*
840 * Round the symbol size up to align.
841 */
842 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
843 cp = malloc(sizeof(struct common_symbol)
844 + common_size + strlen(name) + 1, M_LINKER,
845 M_WAITOK | M_ZERO);
846 cp->address = (caddr_t)(cp + 1);
847 cp->name = cp->address + common_size;
848 strcpy(cp->name, name);
849 bzero(cp->address, common_size);
850 STAILQ_INSERT_TAIL(&file->common, cp, link);
851
852 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
853 " value=%p\n", cp->address));
854 return (cp->address);
855 }
856 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
857 return (0);
858 }
859
860 /*
861 * Both DDB and stack(9) rely on the kernel linker to provide forward and
862 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
863 * do this in a lockfree manner. We provide a set of internal helper
864 * routines to perform these operations without locks, and then wrappers that
865 * optionally lock.
866 *
867 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
868 */
869 #ifdef DDB
870 static int
871 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
872 {
873 linker_file_t lf;
874
875 TAILQ_FOREACH(lf, &linker_files, link) {
876 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
877 return (0);
878 }
879 return (ENOENT);
880 }
881 #endif
882
883 static int
884 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
885 {
886 linker_file_t lf;
887 c_linker_sym_t best, es;
888 u_long diff, bestdiff, off;
889
890 best = 0;
891 off = (uintptr_t)value;
892 bestdiff = off;
893 TAILQ_FOREACH(lf, &linker_files, link) {
894 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
895 continue;
896 if (es != 0 && diff < bestdiff) {
897 best = es;
898 bestdiff = diff;
899 }
900 if (bestdiff == 0)
901 break;
902 }
903 if (best) {
904 *sym = best;
905 *diffp = bestdiff;
906 return (0);
907 } else {
908 *sym = 0;
909 *diffp = off;
910 return (ENOENT);
911 }
912 }
913
914 static int
915 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
916 {
917 linker_file_t lf;
918
919 TAILQ_FOREACH(lf, &linker_files, link) {
920 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
921 return (0);
922 }
923 return (ENOENT);
924 }
925
926 static int
927 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
928 long *offset)
929 {
930 linker_symval_t symval;
931 c_linker_sym_t sym;
932 int error;
933
934 *offset = 0;
935 error = linker_debug_search_symbol(value, &sym, offset);
936 if (error)
937 return (error);
938 error = linker_debug_symbol_values(sym, &symval);
939 if (error)
940 return (error);
941 strlcpy(buf, symval.name, buflen);
942 return (0);
943 }
944
945 /*
946 * DDB Helpers. DDB has to look across multiple files with their own symbol
947 * tables and string tables.
948 *
949 * Note that we do not obey list locking protocols here. We really don't need
950 * DDB to hang because somebody's got the lock held. We'll take the chance
951 * that the files list is inconsistent instead.
952 */
953 #ifdef DDB
954 int
955 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
956 {
957
958 return (linker_debug_lookup(symstr, sym));
959 }
960 #endif
961
962 int
963 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
964 {
965
966 return (linker_debug_search_symbol(value, sym, diffp));
967 }
968
969 int
970 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
971 {
972
973 return (linker_debug_symbol_values(sym, symval));
974 }
975
976 int
977 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
978 long *offset)
979 {
980
981 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
982 }
983
984 /*
985 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
986 * obey locking protocols, and offer a significantly less complex interface.
987 */
988 int
989 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
990 long *offset)
991 {
992 int error;
993
994 sx_xlock(&kld_sx);
995 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
996 sx_xunlock(&kld_sx);
997 return (error);
998 }
999
1000 /*
1001 * Syscalls.
1002 */
1003 int
1004 kern_kldload(struct thread *td, const char *file, int *fileid)
1005 {
1006 const char *kldname, *modname;
1007 linker_file_t lf;
1008 int error;
1009
1010 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1011 return (error);
1012
1013 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1014 return (error);
1015
1016 /*
1017 * It is possible that kldloaded module will attach a new ifnet,
1018 * so vnet context must be set when this ocurs.
1019 */
1020 CURVNET_SET(TD_TO_VNET(td));
1021
1022 /*
1023 * If file does not contain a qualified name or any dot in it
1024 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1025 * name.
1026 */
1027 if (strchr(file, '/') || strchr(file, '.')) {
1028 kldname = file;
1029 modname = NULL;
1030 } else {
1031 kldname = NULL;
1032 modname = file;
1033 }
1034
1035 sx_xlock(&kld_sx);
1036 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1037 if (error) {
1038 sx_xunlock(&kld_sx);
1039 goto done;
1040 }
1041 lf->userrefs++;
1042 if (fileid != NULL)
1043 *fileid = lf->id;
1044 sx_xunlock(&kld_sx);
1045
1046 done:
1047 CURVNET_RESTORE();
1048 return (error);
1049 }
1050
1051 int
1052 sys_kldload(struct thread *td, struct kldload_args *uap)
1053 {
1054 char *pathname = NULL;
1055 int error, fileid;
1056
1057 td->td_retval[0] = -1;
1058
1059 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1060 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1061 if (error == 0) {
1062 error = kern_kldload(td, pathname, &fileid);
1063 if (error == 0)
1064 td->td_retval[0] = fileid;
1065 }
1066 free(pathname, M_TEMP);
1067 return (error);
1068 }
1069
1070 int
1071 kern_kldunload(struct thread *td, int fileid, int flags)
1072 {
1073 linker_file_t lf;
1074 int error = 0;
1075
1076 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1077 return (error);
1078
1079 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1080 return (error);
1081
1082 CURVNET_SET(TD_TO_VNET(td));
1083 sx_xlock(&kld_sx);
1084 lf = linker_find_file_by_id(fileid);
1085 if (lf) {
1086 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1087
1088 if (lf->userrefs == 0) {
1089 /*
1090 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1091 */
1092 printf("kldunload: attempt to unload file that was"
1093 " loaded by the kernel\n");
1094 error = EBUSY;
1095 } else {
1096 lf->userrefs--;
1097 error = linker_file_unload(lf, flags);
1098 if (error)
1099 lf->userrefs++;
1100 }
1101 } else
1102 error = ENOENT;
1103 sx_xunlock(&kld_sx);
1104
1105 CURVNET_RESTORE();
1106 return (error);
1107 }
1108
1109 int
1110 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1111 {
1112
1113 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1114 }
1115
1116 int
1117 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1118 {
1119
1120 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1121 uap->flags != LINKER_UNLOAD_FORCE)
1122 return (EINVAL);
1123 return (kern_kldunload(td, uap->fileid, uap->flags));
1124 }
1125
1126 int
1127 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1128 {
1129 char *pathname;
1130 const char *filename;
1131 linker_file_t lf;
1132 int error;
1133
1134 #ifdef MAC
1135 error = mac_kld_check_stat(td->td_ucred);
1136 if (error)
1137 return (error);
1138 #endif
1139
1140 td->td_retval[0] = -1;
1141
1142 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1143 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1144 goto out;
1145
1146 filename = linker_basename(pathname);
1147 sx_xlock(&kld_sx);
1148 lf = linker_find_file_by_name(filename);
1149 if (lf)
1150 td->td_retval[0] = lf->id;
1151 else
1152 error = ENOENT;
1153 sx_xunlock(&kld_sx);
1154 out:
1155 free(pathname, M_TEMP);
1156 return (error);
1157 }
1158
1159 int
1160 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1161 {
1162 linker_file_t lf;
1163 int error = 0;
1164
1165 #ifdef MAC
1166 error = mac_kld_check_stat(td->td_ucred);
1167 if (error)
1168 return (error);
1169 #endif
1170
1171 sx_xlock(&kld_sx);
1172 if (uap->fileid == 0)
1173 lf = TAILQ_FIRST(&linker_files);
1174 else {
1175 lf = linker_find_file_by_id(uap->fileid);
1176 if (lf == NULL) {
1177 error = ENOENT;
1178 goto out;
1179 }
1180 lf = TAILQ_NEXT(lf, link);
1181 }
1182
1183 /* Skip partially loaded files. */
1184 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1185 lf = TAILQ_NEXT(lf, link);
1186
1187 if (lf)
1188 td->td_retval[0] = lf->id;
1189 else
1190 td->td_retval[0] = 0;
1191 out:
1192 sx_xunlock(&kld_sx);
1193 return (error);
1194 }
1195
1196 int
1197 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1198 {
1199 struct kld_file_stat *stat;
1200 int error, version;
1201
1202 /*
1203 * Check the version of the user's structure.
1204 */
1205 if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1206 != 0)
1207 return (error);
1208 if (version != sizeof(struct kld_file_stat_1) &&
1209 version != sizeof(struct kld_file_stat))
1210 return (EINVAL);
1211
1212 stat = malloc(sizeof(*stat), M_TEMP, M_WAITOK | M_ZERO);
1213 error = kern_kldstat(td, uap->fileid, stat);
1214 if (error == 0)
1215 error = copyout(stat, uap->stat, version);
1216 free(stat, M_TEMP);
1217 return (error);
1218 }
1219
1220 int
1221 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1222 {
1223 linker_file_t lf;
1224 int namelen;
1225 #ifdef MAC
1226 int error;
1227
1228 error = mac_kld_check_stat(td->td_ucred);
1229 if (error)
1230 return (error);
1231 #endif
1232
1233 sx_xlock(&kld_sx);
1234 lf = linker_find_file_by_id(fileid);
1235 if (lf == NULL) {
1236 sx_xunlock(&kld_sx);
1237 return (ENOENT);
1238 }
1239
1240 /* Version 1 fields: */
1241 namelen = strlen(lf->filename) + 1;
1242 if (namelen > MAXPATHLEN)
1243 namelen = MAXPATHLEN;
1244 bcopy(lf->filename, &stat->name[0], namelen);
1245 stat->refs = lf->refs;
1246 stat->id = lf->id;
1247 stat->address = lf->address;
1248 stat->size = lf->size;
1249 /* Version 2 fields: */
1250 namelen = strlen(lf->pathname) + 1;
1251 if (namelen > MAXPATHLEN)
1252 namelen = MAXPATHLEN;
1253 bcopy(lf->pathname, &stat->pathname[0], namelen);
1254 sx_xunlock(&kld_sx);
1255
1256 td->td_retval[0] = 0;
1257 return (0);
1258 }
1259
1260 int
1261 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1262 {
1263 linker_file_t lf;
1264 module_t mp;
1265 int error = 0;
1266
1267 #ifdef MAC
1268 error = mac_kld_check_stat(td->td_ucred);
1269 if (error)
1270 return (error);
1271 #endif
1272
1273 sx_xlock(&kld_sx);
1274 lf = linker_find_file_by_id(uap->fileid);
1275 if (lf) {
1276 MOD_SLOCK;
1277 mp = TAILQ_FIRST(&lf->modules);
1278 if (mp != NULL)
1279 td->td_retval[0] = module_getid(mp);
1280 else
1281 td->td_retval[0] = 0;
1282 MOD_SUNLOCK;
1283 } else
1284 error = ENOENT;
1285 sx_xunlock(&kld_sx);
1286 return (error);
1287 }
1288
1289 int
1290 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1291 {
1292 char *symstr = NULL;
1293 c_linker_sym_t sym;
1294 linker_symval_t symval;
1295 linker_file_t lf;
1296 struct kld_sym_lookup lookup;
1297 int error = 0;
1298
1299 #ifdef MAC
1300 error = mac_kld_check_stat(td->td_ucred);
1301 if (error)
1302 return (error);
1303 #endif
1304
1305 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1306 return (error);
1307 if (lookup.version != sizeof(lookup) ||
1308 uap->cmd != KLDSYM_LOOKUP)
1309 return (EINVAL);
1310 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1311 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1312 goto out;
1313 sx_xlock(&kld_sx);
1314 if (uap->fileid != 0) {
1315 lf = linker_find_file_by_id(uap->fileid);
1316 if (lf == NULL)
1317 error = ENOENT;
1318 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1319 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1320 lookup.symvalue = (uintptr_t) symval.value;
1321 lookup.symsize = symval.size;
1322 error = copyout(&lookup, uap->data, sizeof(lookup));
1323 } else
1324 error = ENOENT;
1325 } else {
1326 TAILQ_FOREACH(lf, &linker_files, link) {
1327 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1328 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1329 lookup.symvalue = (uintptr_t)symval.value;
1330 lookup.symsize = symval.size;
1331 error = copyout(&lookup, uap->data,
1332 sizeof(lookup));
1333 break;
1334 }
1335 }
1336 if (lf == NULL)
1337 error = ENOENT;
1338 }
1339 sx_xunlock(&kld_sx);
1340 out:
1341 free(symstr, M_TEMP);
1342 return (error);
1343 }
1344
1345 /*
1346 * Preloaded module support
1347 */
1348
1349 static modlist_t
1350 modlist_lookup(const char *name, int ver)
1351 {
1352 modlist_t mod;
1353
1354 TAILQ_FOREACH(mod, &found_modules, link) {
1355 if (strcmp(mod->name, name) == 0 &&
1356 (ver == 0 || mod->version == ver))
1357 return (mod);
1358 }
1359 return (NULL);
1360 }
1361
1362 static modlist_t
1363 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1364 {
1365 modlist_t mod, bestmod;
1366 int ver;
1367
1368 if (verinfo == NULL)
1369 return (modlist_lookup(name, 0));
1370 bestmod = NULL;
1371 TAILQ_FOREACH(mod, &found_modules, link) {
1372 if (strcmp(mod->name, name) != 0)
1373 continue;
1374 ver = mod->version;
1375 if (ver == verinfo->md_ver_preferred)
1376 return (mod);
1377 if (ver >= verinfo->md_ver_minimum &&
1378 ver <= verinfo->md_ver_maximum &&
1379 (bestmod == NULL || ver > bestmod->version))
1380 bestmod = mod;
1381 }
1382 return (bestmod);
1383 }
1384
1385 static modlist_t
1386 modlist_newmodule(const char *modname, int version, linker_file_t container)
1387 {
1388 modlist_t mod;
1389
1390 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1391 if (mod == NULL)
1392 panic("no memory for module list");
1393 mod->container = container;
1394 mod->name = modname;
1395 mod->version = version;
1396 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1397 return (mod);
1398 }
1399
1400 static void
1401 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1402 struct mod_metadata **stop, int preload)
1403 {
1404 struct mod_metadata *mp, **mdp;
1405 const char *modname;
1406 int ver;
1407
1408 for (mdp = start; mdp < stop; mdp++) {
1409 mp = *mdp;
1410 if (mp->md_type != MDT_VERSION)
1411 continue;
1412 modname = mp->md_cval;
1413 ver = ((struct mod_version *)mp->md_data)->mv_version;
1414 if (modlist_lookup(modname, ver) != NULL) {
1415 printf("module %s already present!\n", modname);
1416 /* XXX what can we do? this is a build error. :-( */
1417 continue;
1418 }
1419 modlist_newmodule(modname, ver, lf);
1420 }
1421 }
1422
1423 static void
1424 linker_preload(void *arg)
1425 {
1426 caddr_t modptr;
1427 const char *modname, *nmodname;
1428 char *modtype;
1429 linker_file_t lf, nlf;
1430 linker_class_t lc;
1431 int error;
1432 linker_file_list_t loaded_files;
1433 linker_file_list_t depended_files;
1434 struct mod_metadata *mp, *nmp;
1435 struct mod_metadata **start, **stop, **mdp, **nmdp;
1436 struct mod_depend *verinfo;
1437 int nver;
1438 int resolves;
1439 modlist_t mod;
1440 struct sysinit **si_start, **si_stop;
1441
1442 TAILQ_INIT(&loaded_files);
1443 TAILQ_INIT(&depended_files);
1444 TAILQ_INIT(&found_modules);
1445 error = 0;
1446
1447 modptr = NULL;
1448 sx_xlock(&kld_sx);
1449 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1450 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1451 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1452 if (modname == NULL) {
1453 printf("Preloaded module at %p does not have a"
1454 " name!\n", modptr);
1455 continue;
1456 }
1457 if (modtype == NULL) {
1458 printf("Preloaded module at %p does not have a type!\n",
1459 modptr);
1460 continue;
1461 }
1462 if (bootverbose)
1463 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1464 modptr);
1465 lf = NULL;
1466 TAILQ_FOREACH(lc, &classes, link) {
1467 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1468 if (!error)
1469 break;
1470 lf = NULL;
1471 }
1472 if (lf)
1473 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1474 }
1475
1476 /*
1477 * First get a list of stuff in the kernel.
1478 */
1479 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1480 &stop, NULL) == 0)
1481 linker_addmodules(linker_kernel_file, start, stop, 1);
1482
1483 /*
1484 * This is a once-off kinky bubble sort to resolve relocation
1485 * dependency requirements.
1486 */
1487 restart:
1488 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1489 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1490 &stop, NULL);
1491 /*
1492 * First, look to see if we would successfully link with this
1493 * stuff.
1494 */
1495 resolves = 1; /* unless we know otherwise */
1496 if (!error) {
1497 for (mdp = start; mdp < stop; mdp++) {
1498 mp = *mdp;
1499 if (mp->md_type != MDT_DEPEND)
1500 continue;
1501 modname = mp->md_cval;
1502 verinfo = mp->md_data;
1503 for (nmdp = start; nmdp < stop; nmdp++) {
1504 nmp = *nmdp;
1505 if (nmp->md_type != MDT_VERSION)
1506 continue;
1507 nmodname = nmp->md_cval;
1508 if (strcmp(modname, nmodname) == 0)
1509 break;
1510 }
1511 if (nmdp < stop) /* it's a self reference */
1512 continue;
1513
1514 /*
1515 * ok, the module isn't here yet, we
1516 * are not finished
1517 */
1518 if (modlist_lookup2(modname, verinfo) == NULL)
1519 resolves = 0;
1520 }
1521 }
1522 /*
1523 * OK, if we found our modules, we can link. So, "provide"
1524 * the modules inside and add it to the end of the link order
1525 * list.
1526 */
1527 if (resolves) {
1528 if (!error) {
1529 for (mdp = start; mdp < stop; mdp++) {
1530 mp = *mdp;
1531 if (mp->md_type != MDT_VERSION)
1532 continue;
1533 modname = mp->md_cval;
1534 nver = ((struct mod_version *)
1535 mp->md_data)->mv_version;
1536 if (modlist_lookup(modname,
1537 nver) != NULL) {
1538 printf("module %s already"
1539 " present!\n", modname);
1540 TAILQ_REMOVE(&loaded_files,
1541 lf, loaded);
1542 linker_file_unload(lf,
1543 LINKER_UNLOAD_FORCE);
1544 /* we changed tailq next ptr */
1545 goto restart;
1546 }
1547 modlist_newmodule(modname, nver, lf);
1548 }
1549 }
1550 TAILQ_REMOVE(&loaded_files, lf, loaded);
1551 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1552 /*
1553 * Since we provided modules, we need to restart the
1554 * sort so that the previous files that depend on us
1555 * have a chance. Also, we've busted the tailq next
1556 * pointer with the REMOVE.
1557 */
1558 goto restart;
1559 }
1560 }
1561
1562 /*
1563 * At this point, we check to see what could not be resolved..
1564 */
1565 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1566 TAILQ_REMOVE(&loaded_files, lf, loaded);
1567 printf("KLD file %s is missing dependencies\n", lf->filename);
1568 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1569 }
1570
1571 /*
1572 * We made it. Finish off the linking in the order we determined.
1573 */
1574 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1575 if (linker_kernel_file) {
1576 linker_kernel_file->refs++;
1577 error = linker_file_add_dependency(lf,
1578 linker_kernel_file);
1579 if (error)
1580 panic("cannot add dependency");
1581 }
1582 lf->userrefs++; /* so we can (try to) kldunload it */
1583 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1584 &stop, NULL);
1585 if (!error) {
1586 for (mdp = start; mdp < stop; mdp++) {
1587 mp = *mdp;
1588 if (mp->md_type != MDT_DEPEND)
1589 continue;
1590 modname = mp->md_cval;
1591 verinfo = mp->md_data;
1592 mod = modlist_lookup2(modname, verinfo);
1593 if (mod == NULL) {
1594 printf("KLD file %s - cannot find "
1595 "dependency \"%s\"\n",
1596 lf->filename, modname);
1597 goto fail;
1598 }
1599 /* Don't count self-dependencies */
1600 if (lf == mod->container)
1601 continue;
1602 mod->container->refs++;
1603 error = linker_file_add_dependency(lf,
1604 mod->container);
1605 if (error)
1606 panic("cannot add dependency");
1607 }
1608 }
1609 /*
1610 * Now do relocation etc using the symbol search paths
1611 * established by the dependencies
1612 */
1613 error = LINKER_LINK_PRELOAD_FINISH(lf);
1614 if (error) {
1615 printf("KLD file %s - could not finalize loading\n",
1616 lf->filename);
1617 goto fail;
1618 }
1619 linker_file_register_modules(lf);
1620 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1621 &si_stop, NULL) == 0)
1622 sysinit_add(si_start, si_stop);
1623 linker_file_register_sysctls(lf);
1624 lf->flags |= LINKER_FILE_LINKED;
1625 continue;
1626 fail:
1627 TAILQ_REMOVE(&depended_files, lf, loaded);
1628 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1629 }
1630 sx_xunlock(&kld_sx);
1631 /* woohoo! we made it! */
1632 }
1633
1634 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1635
1636 /*
1637 * Search for a not-loaded module by name.
1638 *
1639 * Modules may be found in the following locations:
1640 *
1641 * - preloaded (result is just the module name) - on disk (result is full path
1642 * to module)
1643 *
1644 * If the module name is qualified in any way (contains path, etc.) the we
1645 * simply return a copy of it.
1646 *
1647 * The search path can be manipulated via sysctl. Note that we use the ';'
1648 * character as a separator to be consistent with the bootloader.
1649 */
1650
1651 static char linker_hintfile[] = "linker.hints";
1652 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1653
1654 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1655 sizeof(linker_path), "module load search path");
1656
1657 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1658
1659 static char *linker_ext_list[] = {
1660 "",
1661 ".ko",
1662 NULL
1663 };
1664
1665 /*
1666 * Check if file actually exists either with or without extension listed in
1667 * the linker_ext_list. (probably should be generic for the rest of the
1668 * kernel)
1669 */
1670 static char *
1671 linker_lookup_file(const char *path, int pathlen, const char *name,
1672 int namelen, struct vattr *vap)
1673 {
1674 struct nameidata nd;
1675 struct thread *td = curthread; /* XXX */
1676 char *result, **cpp, *sep;
1677 int error, len, extlen, reclen, flags;
1678 enum vtype type;
1679
1680 extlen = 0;
1681 for (cpp = linker_ext_list; *cpp; cpp++) {
1682 len = strlen(*cpp);
1683 if (len > extlen)
1684 extlen = len;
1685 }
1686 extlen++; /* trailing '\0' */
1687 sep = (path[pathlen - 1] != '/') ? "/" : "";
1688
1689 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1690 result = malloc(reclen, M_LINKER, M_WAITOK);
1691 for (cpp = linker_ext_list; *cpp; cpp++) {
1692 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1693 namelen, name, *cpp);
1694 /*
1695 * Attempt to open the file, and return the path if
1696 * we succeed and it's a regular file.
1697 */
1698 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1699 flags = FREAD;
1700 error = vn_open(&nd, &flags, 0, NULL);
1701 if (error == 0) {
1702 NDFREE(&nd, NDF_ONLY_PNBUF);
1703 type = nd.ni_vp->v_type;
1704 if (vap)
1705 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1706 VOP_UNLOCK(nd.ni_vp, 0);
1707 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1708 if (type == VREG)
1709 return (result);
1710 }
1711 }
1712 free(result, M_LINKER);
1713 return (NULL);
1714 }
1715
1716 #define INT_ALIGN(base, ptr) ptr = \
1717 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1718
1719 /*
1720 * Lookup KLD which contains requested module in the "linker.hints" file. If
1721 * version specification is available, then try to find the best KLD.
1722 * Otherwise just find the latest one.
1723 */
1724 static char *
1725 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1726 int modnamelen, struct mod_depend *verinfo)
1727 {
1728 struct thread *td = curthread; /* XXX */
1729 struct ucred *cred = td ? td->td_ucred : NULL;
1730 struct nameidata nd;
1731 struct vattr vattr, mattr;
1732 u_char *hints = NULL;
1733 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1734 int error, ival, bestver, *intp, found, flags, clen, blen;
1735 ssize_t reclen;
1736
1737 result = NULL;
1738 bestver = found = 0;
1739
1740 sep = (path[pathlen - 1] != '/') ? "/" : "";
1741 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1742 strlen(sep) + 1;
1743 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1744 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1745 linker_hintfile);
1746
1747 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1748 flags = FREAD;
1749 error = vn_open(&nd, &flags, 0, NULL);
1750 if (error)
1751 goto bad;
1752 NDFREE(&nd, NDF_ONLY_PNBUF);
1753 if (nd.ni_vp->v_type != VREG)
1754 goto bad;
1755 best = cp = NULL;
1756 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1757 if (error)
1758 goto bad;
1759 /*
1760 * XXX: we need to limit this number to some reasonable value
1761 */
1762 if (vattr.va_size > 100 * 1024) {
1763 printf("hints file too large %ld\n", (long)vattr.va_size);
1764 goto bad;
1765 }
1766 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1767 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1768 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1769 if (error)
1770 goto bad;
1771 VOP_UNLOCK(nd.ni_vp, 0);
1772 vn_close(nd.ni_vp, FREAD, cred, td);
1773 nd.ni_vp = NULL;
1774 if (reclen != 0) {
1775 printf("can't read %zd\n", reclen);
1776 goto bad;
1777 }
1778 intp = (int *)hints;
1779 ival = *intp++;
1780 if (ival != LINKER_HINTS_VERSION) {
1781 printf("hints file version mismatch %d\n", ival);
1782 goto bad;
1783 }
1784 bufend = hints + vattr.va_size;
1785 recptr = (u_char *)intp;
1786 clen = blen = 0;
1787 while (recptr < bufend && !found) {
1788 intp = (int *)recptr;
1789 reclen = *intp++;
1790 ival = *intp++;
1791 cp = (char *)intp;
1792 switch (ival) {
1793 case MDT_VERSION:
1794 clen = *cp++;
1795 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1796 break;
1797 cp += clen;
1798 INT_ALIGN(hints, cp);
1799 ival = *(int *)cp;
1800 cp += sizeof(int);
1801 clen = *cp++;
1802 if (verinfo == NULL ||
1803 ival == verinfo->md_ver_preferred) {
1804 found = 1;
1805 break;
1806 }
1807 if (ival >= verinfo->md_ver_minimum &&
1808 ival <= verinfo->md_ver_maximum &&
1809 ival > bestver) {
1810 bestver = ival;
1811 best = cp;
1812 blen = clen;
1813 }
1814 break;
1815 default:
1816 break;
1817 }
1818 recptr += reclen + sizeof(int);
1819 }
1820 /*
1821 * Finally check if KLD is in the place
1822 */
1823 if (found)
1824 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1825 else if (best)
1826 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1827
1828 /*
1829 * KLD is newer than hints file. What we should do now?
1830 */
1831 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1832 printf("warning: KLD '%s' is newer than the linker.hints"
1833 " file\n", result);
1834 bad:
1835 free(pathbuf, M_LINKER);
1836 if (hints)
1837 free(hints, M_TEMP);
1838 if (nd.ni_vp != NULL) {
1839 VOP_UNLOCK(nd.ni_vp, 0);
1840 vn_close(nd.ni_vp, FREAD, cred, td);
1841 }
1842 /*
1843 * If nothing found or hints is absent - fallback to the old
1844 * way by using "kldname[.ko]" as module name.
1845 */
1846 if (!found && !bestver && result == NULL)
1847 result = linker_lookup_file(path, pathlen, modname,
1848 modnamelen, NULL);
1849 return (result);
1850 }
1851
1852 /*
1853 * Lookup KLD which contains requested module in the all directories.
1854 */
1855 static char *
1856 linker_search_module(const char *modname, int modnamelen,
1857 struct mod_depend *verinfo)
1858 {
1859 char *cp, *ep, *result;
1860
1861 /*
1862 * traverse the linker path
1863 */
1864 for (cp = linker_path; *cp; cp = ep + 1) {
1865 /* find the end of this component */
1866 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1867 result = linker_hints_lookup(cp, ep - cp, modname,
1868 modnamelen, verinfo);
1869 if (result != NULL)
1870 return (result);
1871 if (*ep == 0)
1872 break;
1873 }
1874 return (NULL);
1875 }
1876
1877 /*
1878 * Search for module in all directories listed in the linker_path.
1879 */
1880 static char *
1881 linker_search_kld(const char *name)
1882 {
1883 char *cp, *ep, *result;
1884 int len;
1885
1886 /* qualified at all? */
1887 if (strchr(name, '/'))
1888 return (strdup(name, M_LINKER));
1889
1890 /* traverse the linker path */
1891 len = strlen(name);
1892 for (ep = linker_path; *ep; ep++) {
1893 cp = ep;
1894 /* find the end of this component */
1895 for (; *ep != 0 && *ep != ';'; ep++);
1896 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1897 if (result != NULL)
1898 return (result);
1899 }
1900 return (NULL);
1901 }
1902
1903 static const char *
1904 linker_basename(const char *path)
1905 {
1906 const char *filename;
1907
1908 filename = strrchr(path, '/');
1909 if (filename == NULL)
1910 return path;
1911 if (filename[1])
1912 filename++;
1913 return (filename);
1914 }
1915
1916 #ifdef HWPMC_HOOKS
1917 /*
1918 * Inform hwpmc about the set of kernel modules currently loaded.
1919 */
1920 void *
1921 linker_hwpmc_list_objects(void)
1922 {
1923 linker_file_t lf;
1924 struct pmckern_map_in *kobase;
1925 int i, nmappings;
1926
1927 nmappings = 0;
1928 sx_slock(&kld_sx);
1929 TAILQ_FOREACH(lf, &linker_files, link)
1930 nmappings++;
1931
1932 /* Allocate nmappings + 1 entries. */
1933 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1934 M_LINKER, M_WAITOK | M_ZERO);
1935 i = 0;
1936 TAILQ_FOREACH(lf, &linker_files, link) {
1937
1938 /* Save the info for this linker file. */
1939 kobase[i].pm_file = lf->filename;
1940 kobase[i].pm_address = (uintptr_t)lf->address;
1941 i++;
1942 }
1943 sx_sunlock(&kld_sx);
1944
1945 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1946
1947 /* The last entry of the malloced area comprises of all zeros. */
1948 KASSERT(kobase[i].pm_file == NULL,
1949 ("linker_hwpmc_list_objects: last object not NULL"));
1950
1951 return ((void *)kobase);
1952 }
1953 #endif
1954
1955 /*
1956 * Find a file which contains given module and load it, if "parent" is not
1957 * NULL, register a reference to it.
1958 */
1959 static int
1960 linker_load_module(const char *kldname, const char *modname,
1961 struct linker_file *parent, struct mod_depend *verinfo,
1962 struct linker_file **lfpp)
1963 {
1964 linker_file_t lfdep;
1965 const char *filename;
1966 char *pathname;
1967 int error;
1968
1969 sx_assert(&kld_sx, SA_XLOCKED);
1970 if (modname == NULL) {
1971 /*
1972 * We have to load KLD
1973 */
1974 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1975 " is not NULL"));
1976 pathname = linker_search_kld(kldname);
1977 } else {
1978 if (modlist_lookup2(modname, verinfo) != NULL)
1979 return (EEXIST);
1980 if (kldname != NULL)
1981 pathname = strdup(kldname, M_LINKER);
1982 else if (rootvnode == NULL)
1983 pathname = NULL;
1984 else
1985 /*
1986 * Need to find a KLD with required module
1987 */
1988 pathname = linker_search_module(modname,
1989 strlen(modname), verinfo);
1990 }
1991 if (pathname == NULL)
1992 return (ENOENT);
1993
1994 /*
1995 * Can't load more than one file with the same basename XXX:
1996 * Actually it should be possible to have multiple KLDs with
1997 * the same basename but different path because they can
1998 * provide different versions of the same modules.
1999 */
2000 filename = linker_basename(pathname);
2001 if (linker_find_file_by_name(filename))
2002 error = EEXIST;
2003 else do {
2004 error = linker_load_file(pathname, &lfdep);
2005 if (error)
2006 break;
2007 if (modname && verinfo &&
2008 modlist_lookup2(modname, verinfo) == NULL) {
2009 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2010 error = ENOENT;
2011 break;
2012 }
2013 if (parent) {
2014 error = linker_file_add_dependency(parent, lfdep);
2015 if (error)
2016 break;
2017 }
2018 if (lfpp)
2019 *lfpp = lfdep;
2020 } while (0);
2021 free(pathname, M_LINKER);
2022 return (error);
2023 }
2024
2025 /*
2026 * This routine is responsible for finding dependencies of userland initiated
2027 * kldload(2)'s of files.
2028 */
2029 int
2030 linker_load_dependencies(linker_file_t lf)
2031 {
2032 linker_file_t lfdep;
2033 struct mod_metadata **start, **stop, **mdp, **nmdp;
2034 struct mod_metadata *mp, *nmp;
2035 struct mod_depend *verinfo;
2036 modlist_t mod;
2037 const char *modname, *nmodname;
2038 int ver, error = 0, count;
2039
2040 /*
2041 * All files are dependent on /kernel.
2042 */
2043 sx_assert(&kld_sx, SA_XLOCKED);
2044 if (linker_kernel_file) {
2045 linker_kernel_file->refs++;
2046 error = linker_file_add_dependency(lf, linker_kernel_file);
2047 if (error)
2048 return (error);
2049 }
2050 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2051 &count) != 0)
2052 return (0);
2053 for (mdp = start; mdp < stop; mdp++) {
2054 mp = *mdp;
2055 if (mp->md_type != MDT_VERSION)
2056 continue;
2057 modname = mp->md_cval;
2058 ver = ((struct mod_version *)mp->md_data)->mv_version;
2059 mod = modlist_lookup(modname, ver);
2060 if (mod != NULL) {
2061 printf("interface %s.%d already present in the KLD"
2062 " '%s'!\n", modname, ver,
2063 mod->container->filename);
2064 return (EEXIST);
2065 }
2066 }
2067
2068 for (mdp = start; mdp < stop; mdp++) {
2069 mp = *mdp;
2070 if (mp->md_type != MDT_DEPEND)
2071 continue;
2072 modname = mp->md_cval;
2073 verinfo = mp->md_data;
2074 nmodname = NULL;
2075 for (nmdp = start; nmdp < stop; nmdp++) {
2076 nmp = *nmdp;
2077 if (nmp->md_type != MDT_VERSION)
2078 continue;
2079 nmodname = nmp->md_cval;
2080 if (strcmp(modname, nmodname) == 0)
2081 break;
2082 }
2083 if (nmdp < stop)/* early exit, it's a self reference */
2084 continue;
2085 mod = modlist_lookup2(modname, verinfo);
2086 if (mod) { /* woohoo, it's loaded already */
2087 lfdep = mod->container;
2088 lfdep->refs++;
2089 error = linker_file_add_dependency(lf, lfdep);
2090 if (error)
2091 break;
2092 continue;
2093 }
2094 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2095 if (error) {
2096 printf("KLD %s: depends on %s - not available or"
2097 " version mismatch\n", lf->filename, modname);
2098 break;
2099 }
2100 }
2101
2102 if (error)
2103 return (error);
2104 linker_addmodules(lf, start, stop, 0);
2105 return (error);
2106 }
2107
2108 static int
2109 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2110 {
2111 struct sysctl_req *req;
2112
2113 req = opaque;
2114 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2115 }
2116
2117 /*
2118 * Export a nul-separated, double-nul-terminated list of all function names
2119 * in the kernel.
2120 */
2121 static int
2122 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2123 {
2124 linker_file_t lf;
2125 int error;
2126
2127 #ifdef MAC
2128 error = mac_kld_check_stat(req->td->td_ucred);
2129 if (error)
2130 return (error);
2131 #endif
2132 error = sysctl_wire_old_buffer(req, 0);
2133 if (error != 0)
2134 return (error);
2135 sx_xlock(&kld_sx);
2136 TAILQ_FOREACH(lf, &linker_files, link) {
2137 error = LINKER_EACH_FUNCTION_NAME(lf,
2138 sysctl_kern_function_list_iterate, req);
2139 if (error) {
2140 sx_xunlock(&kld_sx);
2141 return (error);
2142 }
2143 }
2144 sx_xunlock(&kld_sx);
2145 return (SYSCTL_OUT(req, "", 1));
2146 }
2147
2148 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2149 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: 317eaea8d8a9ca37db5a8c7ca8c291a5
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