xref: /freebsd/sys/kern/kern_linker.c (revision c9b645b50be5adebc3bd7927726af474caea6098)
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("$FreeBSD$");
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 #define	KLD_LOCK()		sx_xlock(&kld_sx)
75 #define	KLD_UNLOCK()		sx_xunlock(&kld_sx)
76 #define	KLD_DOWNGRADE()		sx_downgrade(&kld_sx)
77 #define	KLD_LOCK_READ()		sx_slock(&kld_sx)
78 #define	KLD_UNLOCK_READ()	sx_sunlock(&kld_sx)
79 #define	KLD_LOCKED()		sx_xlocked(&kld_sx)
80 #define	KLD_LOCK_ASSERT() do {						\
81 	if (!cold)							\
82 		sx_assert(&kld_sx, SX_XLOCKED);				\
83 } while (0)
84 
85 /*
86  * static char *linker_search_path(const char *name, struct mod_depend
87  * *verinfo);
88  */
89 static const char 	*linker_basename(const char *path);
90 
91 /*
92  * Find a currently loaded file given its filename.
93  */
94 static linker_file_t linker_find_file_by_name(const char* _filename);
95 
96 /*
97  * Find a currently loaded file given its file id.
98  */
99 static linker_file_t linker_find_file_by_id(int _fileid);
100 
101 /* Metadata from the static kernel */
102 SET_DECLARE(modmetadata_set, struct mod_metadata);
103 
104 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
105 
106 linker_file_t linker_kernel_file;
107 
108 static struct sx kld_sx;	/* kernel linker lock */
109 
110 /*
111  * Load counter used by clients to determine if a linker file has been
112  * re-loaded. This counter is incremented for each file load.
113  */
114 static int loadcnt;
115 
116 static linker_class_list_t classes;
117 static linker_file_list_t linker_files;
118 static int next_file_id = 1;
119 static int linker_no_more_classes = 0;
120 
121 #define	LINKER_GET_NEXT_FILE_ID(a) do {					\
122 	linker_file_t lftmp;						\
123 									\
124 	KLD_LOCK_ASSERT();						\
125 retry:									\
126 	TAILQ_FOREACH(lftmp, &linker_files, link) {			\
127 		if (next_file_id == lftmp->id) {			\
128 			next_file_id++;					\
129 			goto retry;					\
130 		}							\
131 	}								\
132 	(a) = next_file_id;						\
133 } while(0)
134 
135 
136 /* XXX wrong name; we're looking at version provision tags here, not modules */
137 typedef TAILQ_HEAD(, modlist) modlisthead_t;
138 struct modlist {
139 	TAILQ_ENTRY(modlist) link;	/* chain together all modules */
140 	linker_file_t   container;
141 	const char 	*name;
142 	int             version;
143 };
144 typedef struct modlist *modlist_t;
145 static modlisthead_t found_modules;
146 
147 static int	linker_file_add_dependency(linker_file_t file,
148 		    linker_file_t dep);
149 static caddr_t	linker_file_lookup_symbol_internal(linker_file_t file,
150 		    const char* name, int deps);
151 static int	linker_load_module(const char *kldname,
152 		    const char *modname, struct linker_file *parent,
153 		    struct mod_depend *verinfo, struct linker_file **lfpp);
154 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
155 
156 static char *
157 linker_strdup(const char *str)
158 {
159 	char *result;
160 
161 	if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
162 		strcpy(result, str);
163 	return (result);
164 }
165 
166 static void
167 linker_init(void *arg)
168 {
169 
170 	sx_init(&kld_sx, "kernel linker");
171 	TAILQ_INIT(&classes);
172 	TAILQ_INIT(&linker_files);
173 }
174 
175 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
176 
177 static void
178 linker_stop_class_add(void *arg)
179 {
180 
181 	linker_no_more_classes = 1;
182 }
183 
184 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
185 
186 int
187 linker_add_class(linker_class_t lc)
188 {
189 
190 	/*
191 	 * We disallow any class registration past SI_ORDER_ANY
192 	 * of SI_SUB_KLD.  We bump the reference count to keep the
193 	 * ops from being freed.
194 	 */
195 	if (linker_no_more_classes == 1)
196 		return (EPERM);
197 	kobj_class_compile((kobj_class_t) lc);
198 	((kobj_class_t)lc)->refs++;	/* XXX: kobj_mtx */
199 	TAILQ_INSERT_TAIL(&classes, lc, link);
200 	return (0);
201 }
202 
203 static void
204 linker_file_sysinit(linker_file_t lf)
205 {
206 	struct sysinit **start, **stop, **sipp, **xipp, *save;
207 
208 	KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
209 	    lf->filename));
210 
211 	if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
212 		return;
213 	/*
214 	 * Perform a bubble sort of the system initialization objects by
215 	 * their subsystem (primary key) and order (secondary key).
216 	 *
217 	 * Since some things care about execution order, this is the operation
218 	 * which ensures continued function.
219 	 */
220 	for (sipp = start; sipp < stop; sipp++) {
221 		for (xipp = sipp + 1; xipp < stop; xipp++) {
222 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
223 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
224 			    (*sipp)->order <= (*xipp)->order))
225 				continue;	/* skip */
226 			save = *sipp;
227 			*sipp = *xipp;
228 			*xipp = save;
229 		}
230 	}
231 
232 	/*
233 	 * Traverse the (now) ordered list of system initialization tasks.
234 	 * Perform each task, and continue on to the next task.
235 	 */
236 	mtx_lock(&Giant);
237 	for (sipp = start; sipp < stop; sipp++) {
238 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
239 			continue;	/* skip dummy task(s) */
240 
241 		/* Call function */
242 		(*((*sipp)->func)) ((*sipp)->udata);
243 	}
244 	mtx_unlock(&Giant);
245 }
246 
247 static void
248 linker_file_sysuninit(linker_file_t lf)
249 {
250 	struct sysinit **start, **stop, **sipp, **xipp, *save;
251 
252 	KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
253 	    lf->filename));
254 
255 	if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
256 	    NULL) != 0)
257 		return;
258 
259 	/*
260 	 * Perform a reverse bubble sort of the system initialization objects
261 	 * by their subsystem (primary key) and order (secondary key).
262 	 *
263 	 * Since some things care about execution order, this is the operation
264 	 * which ensures continued function.
265 	 */
266 	for (sipp = start; sipp < stop; sipp++) {
267 		for (xipp = sipp + 1; xipp < stop; xipp++) {
268 			if ((*sipp)->subsystem > (*xipp)->subsystem ||
269 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
270 			    (*sipp)->order >= (*xipp)->order))
271 				continue;	/* skip */
272 			save = *sipp;
273 			*sipp = *xipp;
274 			*xipp = save;
275 		}
276 	}
277 
278 	/*
279 	 * Traverse the (now) ordered list of system initialization tasks.
280 	 * Perform each task, and continue on to the next task.
281 	 */
282 	mtx_lock(&Giant);
283 	for (sipp = start; sipp < stop; sipp++) {
284 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
285 			continue;	/* skip dummy task(s) */
286 
287 		/* Call function */
288 		(*((*sipp)->func)) ((*sipp)->udata);
289 	}
290 	mtx_unlock(&Giant);
291 }
292 
293 static void
294 linker_file_register_sysctls(linker_file_t lf)
295 {
296 	struct sysctl_oid **start, **stop, **oidp;
297 
298 	KLD_DPF(FILE,
299 	    ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
300 	    lf->filename));
301 
302 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
303 		return;
304 
305 	sysctl_lock();
306 	for (oidp = start; oidp < stop; oidp++)
307 		sysctl_register_oid(*oidp);
308 	sysctl_unlock();
309 }
310 
311 static void
312 linker_file_unregister_sysctls(linker_file_t lf)
313 {
314 	struct sysctl_oid **start, **stop, **oidp;
315 
316 	KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
317 	    " for %s\n", lf->filename));
318 
319 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
320 		return;
321 
322 	sysctl_lock();
323 	for (oidp = start; oidp < stop; oidp++)
324 		sysctl_unregister_oid(*oidp);
325 	sysctl_unlock();
326 }
327 
328 static int
329 linker_file_register_modules(linker_file_t lf)
330 {
331 	struct mod_metadata **start, **stop, **mdp;
332 	const moduledata_t *moddata;
333 	int first_error, error;
334 
335 	KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
336 	    " in %s\n", lf->filename));
337 
338 	if (linker_file_lookup_set(lf, "modmetadata_set", &start,
339 	    &stop, NULL) != 0) {
340 		/*
341 		 * This fallback should be unnecessary, but if we get booted
342 		 * from boot2 instead of loader and we are missing our
343 		 * metadata then we have to try the best we can.
344 		 */
345 		if (lf == linker_kernel_file) {
346 			start = SET_BEGIN(modmetadata_set);
347 			stop = SET_LIMIT(modmetadata_set);
348 		} else
349 			return (0);
350 	}
351 	first_error = 0;
352 	for (mdp = start; mdp < stop; mdp++) {
353 		if ((*mdp)->md_type != MDT_MODULE)
354 			continue;
355 		moddata = (*mdp)->md_data;
356 		KLD_DPF(FILE, ("Registering module %s in %s\n",
357 		    moddata->name, lf->filename));
358 		error = module_register(moddata, lf);
359 		if (error) {
360 			printf("Module %s failed to register: %d\n",
361 			    moddata->name, error);
362 			if (first_error == 0)
363 				first_error = error;
364 		}
365 	}
366 	return (first_error);
367 }
368 
369 static void
370 linker_init_kernel_modules(void)
371 {
372 
373 	linker_file_register_modules(linker_kernel_file);
374 }
375 
376 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
377     0);
378 
379 static int
380 linker_load_file(const char *filename, linker_file_t *result)
381 {
382 	linker_class_t lc;
383 	linker_file_t lf;
384 	int foundfile, error, modules;
385 
386 	/* Refuse to load modules if securelevel raised */
387 	if (prison0.pr_securelevel > 0)
388 		return (EPERM);
389 
390 	KLD_LOCK_ASSERT();
391 	lf = linker_find_file_by_name(filename);
392 	if (lf) {
393 		KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
394 		    " incrementing refs\n", filename));
395 		*result = lf;
396 		lf->refs++;
397 		return (0);
398 	}
399 	foundfile = 0;
400 	error = 0;
401 
402 	/*
403 	 * We do not need to protect (lock) classes here because there is
404 	 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
405 	 * and there is no class deregistration mechanism at this time.
406 	 */
407 	TAILQ_FOREACH(lc, &classes, link) {
408 		KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
409 		    filename));
410 		error = LINKER_LOAD_FILE(lc, filename, &lf);
411 		/*
412 		 * If we got something other than ENOENT, then it exists but
413 		 * we cannot load it for some other reason.
414 		 */
415 		if (error != ENOENT)
416 			foundfile = 1;
417 		if (lf) {
418 			error = linker_file_register_modules(lf);
419 			if (error == EEXIST) {
420 				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
421 				return (error);
422 			}
423 			modules = !TAILQ_EMPTY(&lf->modules);
424 			KLD_UNLOCK();
425 			linker_file_register_sysctls(lf);
426 			linker_file_sysinit(lf);
427 			KLD_LOCK();
428 			lf->flags |= LINKER_FILE_LINKED;
429 
430 			/*
431 			 * If all of the modules in this file failed
432 			 * to load, unload the file and return an
433 			 * error of ENOEXEC.
434 			 */
435 			if (modules && TAILQ_EMPTY(&lf->modules)) {
436 				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
437 				return (ENOEXEC);
438 			}
439 			*result = lf;
440 			return (0);
441 		}
442 	}
443 	/*
444 	 * Less than ideal, but tells the user whether it failed to load or
445 	 * the module was not found.
446 	 */
447 	if (foundfile) {
448 
449 		/*
450 		 * If the file type has not been recognized by the last try
451 		 * printout a message before to fail.
452 		 */
453 		if (error == ENOSYS)
454 			printf("linker_load_file: Unsupported file type\n");
455 
456 		/*
457 		 * Format not recognized or otherwise unloadable.
458 		 * When loading a module that is statically built into
459 		 * the kernel EEXIST percolates back up as the return
460 		 * value.  Preserve this so that apps like sysinstall
461 		 * can recognize this special case and not post bogus
462 		 * dialog boxes.
463 		 */
464 		if (error != EEXIST)
465 			error = ENOEXEC;
466 	} else
467 		error = ENOENT;		/* Nothing found */
468 	return (error);
469 }
470 
471 int
472 linker_reference_module(const char *modname, struct mod_depend *verinfo,
473     linker_file_t *result)
474 {
475 	modlist_t mod;
476 	int error;
477 
478 	KLD_LOCK();
479 	if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
480 		*result = mod->container;
481 		(*result)->refs++;
482 		KLD_UNLOCK();
483 		return (0);
484 	}
485 
486 	error = linker_load_module(NULL, modname, NULL, verinfo, result);
487 	KLD_UNLOCK();
488 	return (error);
489 }
490 
491 int
492 linker_release_module(const char *modname, struct mod_depend *verinfo,
493     linker_file_t lf)
494 {
495 	modlist_t mod;
496 	int error;
497 
498 	KLD_LOCK();
499 	if (lf == NULL) {
500 		KASSERT(modname != NULL,
501 		    ("linker_release_module: no file or name"));
502 		mod = modlist_lookup2(modname, verinfo);
503 		if (mod == NULL) {
504 			KLD_UNLOCK();
505 			return (ESRCH);
506 		}
507 		lf = mod->container;
508 	} else
509 		KASSERT(modname == NULL && verinfo == NULL,
510 		    ("linker_release_module: both file and name"));
511 	error =	linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
512 	KLD_UNLOCK();
513 	return (error);
514 }
515 
516 static linker_file_t
517 linker_find_file_by_name(const char *filename)
518 {
519 	linker_file_t lf;
520 	char *koname;
521 
522 	koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
523 	sprintf(koname, "%s.ko", filename);
524 
525 	KLD_LOCK_ASSERT();
526 	TAILQ_FOREACH(lf, &linker_files, link) {
527 		if (strcmp(lf->filename, koname) == 0)
528 			break;
529 		if (strcmp(lf->filename, filename) == 0)
530 			break;
531 	}
532 	free(koname, M_LINKER);
533 	return (lf);
534 }
535 
536 static linker_file_t
537 linker_find_file_by_id(int fileid)
538 {
539 	linker_file_t lf;
540 
541 	KLD_LOCK_ASSERT();
542 	TAILQ_FOREACH(lf, &linker_files, link)
543 		if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
544 			break;
545 	return (lf);
546 }
547 
548 int
549 linker_file_foreach(linker_predicate_t *predicate, void *context)
550 {
551 	linker_file_t lf;
552 	int retval = 0;
553 
554 	KLD_LOCK();
555 	TAILQ_FOREACH(lf, &linker_files, link) {
556 		retval = predicate(lf, context);
557 		if (retval != 0)
558 			break;
559 	}
560 	KLD_UNLOCK();
561 	return (retval);
562 }
563 
564 linker_file_t
565 linker_make_file(const char *pathname, linker_class_t lc)
566 {
567 	linker_file_t lf;
568 	const char *filename;
569 
570 	KLD_LOCK_ASSERT();
571 	filename = linker_basename(pathname);
572 
573 	KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
574 	lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
575 	if (lf == NULL)
576 		return (NULL);
577 	lf->refs = 1;
578 	lf->userrefs = 0;
579 	lf->flags = 0;
580 	lf->filename = linker_strdup(filename);
581 	lf->pathname = linker_strdup(pathname);
582 	LINKER_GET_NEXT_FILE_ID(lf->id);
583 	lf->ndeps = 0;
584 	lf->deps = NULL;
585 	lf->loadcnt = ++loadcnt;
586 	lf->sdt_probes = NULL;
587 	lf->sdt_nprobes = 0;
588 	STAILQ_INIT(&lf->common);
589 	TAILQ_INIT(&lf->modules);
590 	TAILQ_INSERT_TAIL(&linker_files, lf, link);
591 	return (lf);
592 }
593 
594 int
595 linker_file_unload(linker_file_t file, int flags)
596 {
597 	module_t mod, next;
598 	modlist_t ml, nextml;
599 	struct common_symbol *cp;
600 	int error, i;
601 
602 	/* Refuse to unload modules if securelevel raised. */
603 	if (prison0.pr_securelevel > 0)
604 		return (EPERM);
605 
606 	KLD_LOCK_ASSERT();
607 	KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
608 
609 	/* Easy case of just dropping a reference. */
610 	if (file->refs > 1) {
611 		file->refs--;
612 		return (0);
613 	}
614 
615 	KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
616 	    " informing modules\n"));
617 
618 	/*
619 	 * Quiesce all the modules to give them a chance to veto the unload.
620 	 */
621 	MOD_SLOCK;
622 	for (mod = TAILQ_FIRST(&file->modules); mod;
623 	     mod = module_getfnext(mod)) {
624 
625 		error = module_quiesce(mod);
626 		if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
627 			KLD_DPF(FILE, ("linker_file_unload: module %s"
628 			    " vetoed unload\n", module_getname(mod)));
629 			/*
630 			 * XXX: Do we need to tell all the quiesced modules
631 			 * that they can resume work now via a new module
632 			 * event?
633 			 */
634 			MOD_SUNLOCK;
635 			return (error);
636 		}
637 	}
638 	MOD_SUNLOCK;
639 
640 	/*
641 	 * Inform any modules associated with this file that they are
642 	 * being unloaded.
643 	 */
644 	MOD_XLOCK;
645 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
646 		next = module_getfnext(mod);
647 		MOD_XUNLOCK;
648 
649 		/*
650 		 * Give the module a chance to veto the unload.
651 		 */
652 		if ((error = module_unload(mod)) != 0) {
653 #ifdef KLD_DEBUG
654 			MOD_SLOCK;
655 			KLD_DPF(FILE, ("linker_file_unload: module %s"
656 			    " failed unload\n", module_getname(mod)));
657 			MOD_SUNLOCK;
658 #endif
659 			return (error);
660 		}
661 		MOD_XLOCK;
662 		module_release(mod);
663 	}
664 	MOD_XUNLOCK;
665 
666 	TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
667 		if (ml->container == file) {
668 			TAILQ_REMOVE(&found_modules, ml, link);
669 			free(ml, M_LINKER);
670 		}
671 	}
672 
673 	/*
674 	 * Don't try to run SYSUNINITs if we are unloaded due to a
675 	 * link error.
676 	 */
677 	if (file->flags & LINKER_FILE_LINKED) {
678 		file->flags &= ~LINKER_FILE_LINKED;
679 		KLD_UNLOCK();
680 		linker_file_sysuninit(file);
681 		linker_file_unregister_sysctls(file);
682 		KLD_LOCK();
683 	}
684 	TAILQ_REMOVE(&linker_files, file, link);
685 
686 	if (file->deps) {
687 		for (i = 0; i < file->ndeps; i++)
688 			linker_file_unload(file->deps[i], flags);
689 		free(file->deps, M_LINKER);
690 		file->deps = NULL;
691 	}
692 	while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
693 		STAILQ_REMOVE_HEAD(&file->common, link);
694 		free(cp, M_LINKER);
695 	}
696 
697 	LINKER_UNLOAD(file);
698 	if (file->filename) {
699 		free(file->filename, M_LINKER);
700 		file->filename = NULL;
701 	}
702 	if (file->pathname) {
703 		free(file->pathname, M_LINKER);
704 		file->pathname = NULL;
705 	}
706 	kobj_delete((kobj_t) file, M_LINKER);
707 	return (0);
708 }
709 
710 int
711 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
712 {
713 	return (LINKER_CTF_GET(file, lc));
714 }
715 
716 static int
717 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
718 {
719 	linker_file_t *newdeps;
720 
721 	KLD_LOCK_ASSERT();
722 	newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
723 	    M_LINKER, M_WAITOK | M_ZERO);
724 	if (newdeps == NULL)
725 		return (ENOMEM);
726 
727 	if (file->deps) {
728 		bcopy(file->deps, newdeps,
729 		    file->ndeps * sizeof(linker_file_t *));
730 		free(file->deps, M_LINKER);
731 	}
732 	file->deps = newdeps;
733 	file->deps[file->ndeps] = dep;
734 	file->ndeps++;
735 	KLD_DPF(FILE, ("linker_file_add_dependency:"
736 	    " adding %s as dependency for %s\n",
737 	    dep->filename, file->filename));
738 	return (0);
739 }
740 
741 /*
742  * Locate a linker set and its contents.  This is a helper function to avoid
743  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
744  * This function is used in this file so we can avoid having lots of (void **)
745  * casts.
746  */
747 int
748 linker_file_lookup_set(linker_file_t file, const char *name,
749     void *firstp, void *lastp, int *countp)
750 {
751 	int error, locked;
752 
753 	locked = KLD_LOCKED();
754 	if (!locked)
755 		KLD_LOCK();
756 	error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
757 	if (!locked)
758 		KLD_UNLOCK();
759 	return (error);
760 }
761 
762 /*
763  * List all functions in a file.
764  */
765 int
766 linker_file_function_listall(linker_file_t lf,
767     linker_function_nameval_callback_t callback_func, void *arg)
768 {
769 	return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
770 }
771 
772 caddr_t
773 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
774 {
775 	caddr_t sym;
776 	int locked;
777 
778 	locked = KLD_LOCKED();
779 	if (!locked)
780 		KLD_LOCK();
781 	sym = linker_file_lookup_symbol_internal(file, name, deps);
782 	if (!locked)
783 		KLD_UNLOCK();
784 	return (sym);
785 }
786 
787 static caddr_t
788 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
789     int deps)
790 {
791 	c_linker_sym_t sym;
792 	linker_symval_t symval;
793 	caddr_t address;
794 	size_t common_size = 0;
795 	int i;
796 
797 	KLD_LOCK_ASSERT();
798 	KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
799 	    file, name, deps));
800 
801 	if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
802 		LINKER_SYMBOL_VALUES(file, sym, &symval);
803 		if (symval.value == 0)
804 			/*
805 			 * For commons, first look them up in the
806 			 * dependencies and only allocate space if not found
807 			 * there.
808 			 */
809 			common_size = symval.size;
810 		else {
811 			KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
812 			    ".value=%p\n", symval.value));
813 			return (symval.value);
814 		}
815 	}
816 	if (deps) {
817 		for (i = 0; i < file->ndeps; i++) {
818 			address = linker_file_lookup_symbol_internal(
819 			    file->deps[i], name, 0);
820 			if (address) {
821 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
822 				    " deps value=%p\n", address));
823 				return (address);
824 			}
825 		}
826 	}
827 	if (common_size > 0) {
828 		/*
829 		 * This is a common symbol which was not found in the
830 		 * dependencies.  We maintain a simple common symbol table in
831 		 * the file object.
832 		 */
833 		struct common_symbol *cp;
834 
835 		STAILQ_FOREACH(cp, &file->common, link) {
836 			if (strcmp(cp->name, name) == 0) {
837 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
838 				    " old common value=%p\n", cp->address));
839 				return (cp->address);
840 			}
841 		}
842 		/*
843 		 * Round the symbol size up to align.
844 		 */
845 		common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
846 		cp = malloc(sizeof(struct common_symbol)
847 		    + common_size + strlen(name) + 1, M_LINKER,
848 		    M_WAITOK | M_ZERO);
849 		cp->address = (caddr_t)(cp + 1);
850 		cp->name = cp->address + common_size;
851 		strcpy(cp->name, name);
852 		bzero(cp->address, common_size);
853 		STAILQ_INSERT_TAIL(&file->common, cp, link);
854 
855 		KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
856 		    " value=%p\n", cp->address));
857 		return (cp->address);
858 	}
859 	KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
860 	return (0);
861 }
862 
863 /*
864  * Both DDB and stack(9) rely on the kernel linker to provide forward and
865  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
866  * do this in a lockfree manner.  We provide a set of internal helper
867  * routines to perform these operations without locks, and then wrappers that
868  * optionally lock.
869  *
870  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
871  */
872 #ifdef DDB
873 static int
874 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
875 {
876 	linker_file_t lf;
877 
878 	TAILQ_FOREACH(lf, &linker_files, link) {
879 		if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
880 			return (0);
881 	}
882 	return (ENOENT);
883 }
884 #endif
885 
886 static int
887 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
888 {
889 	linker_file_t lf;
890 	c_linker_sym_t best, es;
891 	u_long diff, bestdiff, off;
892 
893 	best = 0;
894 	off = (uintptr_t)value;
895 	bestdiff = off;
896 	TAILQ_FOREACH(lf, &linker_files, link) {
897 		if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
898 			continue;
899 		if (es != 0 && diff < bestdiff) {
900 			best = es;
901 			bestdiff = diff;
902 		}
903 		if (bestdiff == 0)
904 			break;
905 	}
906 	if (best) {
907 		*sym = best;
908 		*diffp = bestdiff;
909 		return (0);
910 	} else {
911 		*sym = 0;
912 		*diffp = off;
913 		return (ENOENT);
914 	}
915 }
916 
917 static int
918 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
919 {
920 	linker_file_t lf;
921 
922 	TAILQ_FOREACH(lf, &linker_files, link) {
923 		if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
924 			return (0);
925 	}
926 	return (ENOENT);
927 }
928 
929 static int
930 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
931     long *offset)
932 {
933 	linker_symval_t symval;
934 	c_linker_sym_t sym;
935 	int error;
936 
937 	*offset = 0;
938 	error = linker_debug_search_symbol(value, &sym, offset);
939 	if (error)
940 		return (error);
941 	error = linker_debug_symbol_values(sym, &symval);
942 	if (error)
943 		return (error);
944 	strlcpy(buf, symval.name, buflen);
945 	return (0);
946 }
947 
948 /*
949  * DDB Helpers.  DDB has to look across multiple files with their own symbol
950  * tables and string tables.
951  *
952  * Note that we do not obey list locking protocols here.  We really don't need
953  * DDB to hang because somebody's got the lock held.  We'll take the chance
954  * that the files list is inconsistant instead.
955  */
956 #ifdef DDB
957 int
958 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
959 {
960 
961 	return (linker_debug_lookup(symstr, sym));
962 }
963 #endif
964 
965 int
966 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
967 {
968 
969 	return (linker_debug_search_symbol(value, sym, diffp));
970 }
971 
972 int
973 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
974 {
975 
976 	return (linker_debug_symbol_values(sym, symval));
977 }
978 
979 int
980 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
981     long *offset)
982 {
983 
984 	return (linker_debug_search_symbol_name(value, buf, buflen, offset));
985 }
986 
987 /*
988  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
989  * obey locking protocols, and offer a significantly less complex interface.
990  */
991 int
992 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
993     long *offset)
994 {
995 	int error;
996 
997 	KLD_LOCK();
998 	error = linker_debug_search_symbol_name(value, buf, buflen, offset);
999 	KLD_UNLOCK();
1000 	return (error);
1001 }
1002 
1003 /*
1004  * Syscalls.
1005  */
1006 int
1007 kern_kldload(struct thread *td, const char *file, int *fileid)
1008 {
1009 #ifdef HWPMC_HOOKS
1010 	struct pmckern_map_in pkm;
1011 #endif
1012 	const char *kldname, *modname;
1013 	linker_file_t lf;
1014 	int error;
1015 
1016 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1017 		return (error);
1018 
1019 	if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1020 		return (error);
1021 
1022 	/*
1023 	 * It is possible that kldloaded module will attach a new ifnet,
1024 	 * so vnet context must be set when this ocurs.
1025 	 */
1026 	CURVNET_SET(TD_TO_VNET(td));
1027 
1028 	/*
1029 	 * If file does not contain a qualified name or any dot in it
1030 	 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1031 	 * name.
1032 	 */
1033 	if (strchr(file, '/') || strchr(file, '.')) {
1034 		kldname = file;
1035 		modname = NULL;
1036 	} else {
1037 		kldname = NULL;
1038 		modname = file;
1039 	}
1040 
1041 	KLD_LOCK();
1042 	error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1043 	if (error) {
1044 		KLD_UNLOCK();
1045 		goto done;
1046 	}
1047 	lf->userrefs++;
1048 	if (fileid != NULL)
1049 		*fileid = lf->id;
1050 
1051 	EVENTHANDLER_INVOKE(mod_load, lf);
1052 
1053 #ifdef HWPMC_HOOKS
1054 	KLD_DOWNGRADE();
1055 	pkm.pm_file = lf->filename;
1056 	pkm.pm_address = (uintptr_t) lf->address;
1057 	PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
1058 	KLD_UNLOCK_READ();
1059 #else
1060 	KLD_UNLOCK();
1061 #endif
1062 
1063 done:
1064 	CURVNET_RESTORE();
1065 	return (error);
1066 }
1067 
1068 int
1069 sys_kldload(struct thread *td, struct kldload_args *uap)
1070 {
1071 	char *pathname = NULL;
1072 	int error, fileid;
1073 
1074 	td->td_retval[0] = -1;
1075 
1076 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1077 	error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1078 	if (error == 0) {
1079 		error = kern_kldload(td, pathname, &fileid);
1080 		if (error == 0)
1081 			td->td_retval[0] = fileid;
1082 	}
1083 	free(pathname, M_TEMP);
1084 	return (error);
1085 }
1086 
1087 int
1088 kern_kldunload(struct thread *td, int fileid, int flags)
1089 {
1090 #ifdef HWPMC_HOOKS
1091 	struct pmckern_map_out pkm;
1092 #endif
1093 	linker_file_t lf;
1094 	int error = 0;
1095 
1096 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1097 		return (error);
1098 
1099 	if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1100 		return (error);
1101 
1102 	CURVNET_SET(TD_TO_VNET(td));
1103 	KLD_LOCK();
1104 	lf = linker_find_file_by_id(fileid);
1105 	if (lf) {
1106 		KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1107 
1108 		EVENTHANDLER_INVOKE(mod_unload, lf, &error);
1109 		if (error != 0)
1110 			error = EBUSY;
1111 		else if (lf->nenabled > 0) {
1112 			printf("kldunload: attempt to unload file that has"
1113 			    " DTrace probes enabled\n");
1114 			error = EBUSY;
1115 		} else if (lf->userrefs == 0) {
1116 			/*
1117 			 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1118 			 */
1119 			printf("kldunload: attempt to unload file that was"
1120 			    " loaded by the kernel\n");
1121 			error = EBUSY;
1122 		} else {
1123 #ifdef HWPMC_HOOKS
1124 			/* Save data needed by hwpmc(4) before unloading. */
1125 			pkm.pm_address = (uintptr_t) lf->address;
1126 			pkm.pm_size = lf->size;
1127 #endif
1128 			lf->userrefs--;
1129 			error = linker_file_unload(lf, flags);
1130 			if (error)
1131 				lf->userrefs++;
1132 		}
1133 	} else
1134 		error = ENOENT;
1135 
1136 #ifdef HWPMC_HOOKS
1137 	if (error == 0) {
1138 		KLD_DOWNGRADE();
1139 		PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
1140 		KLD_UNLOCK_READ();
1141 	} else
1142 		KLD_UNLOCK();
1143 #else
1144 	KLD_UNLOCK();
1145 #endif
1146 	CURVNET_RESTORE();
1147 	return (error);
1148 }
1149 
1150 int
1151 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1152 {
1153 
1154 	return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1155 }
1156 
1157 int
1158 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1159 {
1160 
1161 	if (uap->flags != LINKER_UNLOAD_NORMAL &&
1162 	    uap->flags != LINKER_UNLOAD_FORCE)
1163 		return (EINVAL);
1164 	return (kern_kldunload(td, uap->fileid, uap->flags));
1165 }
1166 
1167 int
1168 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1169 {
1170 	char *pathname;
1171 	const char *filename;
1172 	linker_file_t lf;
1173 	int error;
1174 
1175 #ifdef MAC
1176 	error = mac_kld_check_stat(td->td_ucred);
1177 	if (error)
1178 		return (error);
1179 #endif
1180 
1181 	td->td_retval[0] = -1;
1182 
1183 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1184 	if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1185 		goto out;
1186 
1187 	filename = linker_basename(pathname);
1188 	KLD_LOCK();
1189 	lf = linker_find_file_by_name(filename);
1190 	if (lf)
1191 		td->td_retval[0] = lf->id;
1192 	else
1193 		error = ENOENT;
1194 	KLD_UNLOCK();
1195 out:
1196 	free(pathname, M_TEMP);
1197 	return (error);
1198 }
1199 
1200 int
1201 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1202 {
1203 	linker_file_t lf;
1204 	int error = 0;
1205 
1206 #ifdef MAC
1207 	error = mac_kld_check_stat(td->td_ucred);
1208 	if (error)
1209 		return (error);
1210 #endif
1211 
1212 	KLD_LOCK();
1213 	if (uap->fileid == 0)
1214 		lf = TAILQ_FIRST(&linker_files);
1215 	else {
1216 		lf = linker_find_file_by_id(uap->fileid);
1217 		if (lf == NULL) {
1218 			error = ENOENT;
1219 			goto out;
1220 		}
1221 		lf = TAILQ_NEXT(lf, link);
1222 	}
1223 
1224 	/* Skip partially loaded files. */
1225 	while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1226 		lf = TAILQ_NEXT(lf, link);
1227 
1228 	if (lf)
1229 		td->td_retval[0] = lf->id;
1230 	else
1231 		td->td_retval[0] = 0;
1232 out:
1233 	KLD_UNLOCK();
1234 	return (error);
1235 }
1236 
1237 int
1238 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1239 {
1240 	struct kld_file_stat stat;
1241 	int error, version;
1242 
1243 	/*
1244 	 * Check the version of the user's structure.
1245 	 */
1246 	if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1247 	    != 0)
1248 		return (error);
1249 	if (version != sizeof(struct kld_file_stat_1) &&
1250 	    version != sizeof(struct kld_file_stat))
1251 		return (EINVAL);
1252 
1253 	error = kern_kldstat(td, uap->fileid, &stat);
1254 	if (error != 0)
1255 		return (error);
1256 	return (copyout(&stat, uap->stat, version));
1257 }
1258 
1259 int
1260 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1261 {
1262 	linker_file_t lf;
1263 	int namelen;
1264 #ifdef MAC
1265 	int error;
1266 
1267 	error = mac_kld_check_stat(td->td_ucred);
1268 	if (error)
1269 		return (error);
1270 #endif
1271 
1272 	KLD_LOCK();
1273 	lf = linker_find_file_by_id(fileid);
1274 	if (lf == NULL) {
1275 		KLD_UNLOCK();
1276 		return (ENOENT);
1277 	}
1278 
1279 	/* Version 1 fields: */
1280 	namelen = strlen(lf->filename) + 1;
1281 	if (namelen > MAXPATHLEN)
1282 		namelen = MAXPATHLEN;
1283 	bcopy(lf->filename, &stat->name[0], namelen);
1284 	stat->refs = lf->refs;
1285 	stat->id = lf->id;
1286 	stat->address = lf->address;
1287 	stat->size = lf->size;
1288 	/* Version 2 fields: */
1289 	namelen = strlen(lf->pathname) + 1;
1290 	if (namelen > MAXPATHLEN)
1291 		namelen = MAXPATHLEN;
1292 	bcopy(lf->pathname, &stat->pathname[0], namelen);
1293 	KLD_UNLOCK();
1294 
1295 	td->td_retval[0] = 0;
1296 	return (0);
1297 }
1298 
1299 int
1300 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1301 {
1302 	linker_file_t lf;
1303 	module_t mp;
1304 	int error = 0;
1305 
1306 #ifdef MAC
1307 	error = mac_kld_check_stat(td->td_ucred);
1308 	if (error)
1309 		return (error);
1310 #endif
1311 
1312 	KLD_LOCK();
1313 	lf = linker_find_file_by_id(uap->fileid);
1314 	if (lf) {
1315 		MOD_SLOCK;
1316 		mp = TAILQ_FIRST(&lf->modules);
1317 		if (mp != NULL)
1318 			td->td_retval[0] = module_getid(mp);
1319 		else
1320 			td->td_retval[0] = 0;
1321 		MOD_SUNLOCK;
1322 	} else
1323 		error = ENOENT;
1324 	KLD_UNLOCK();
1325 	return (error);
1326 }
1327 
1328 int
1329 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1330 {
1331 	char *symstr = NULL;
1332 	c_linker_sym_t sym;
1333 	linker_symval_t symval;
1334 	linker_file_t lf;
1335 	struct kld_sym_lookup lookup;
1336 	int error = 0;
1337 
1338 #ifdef MAC
1339 	error = mac_kld_check_stat(td->td_ucred);
1340 	if (error)
1341 		return (error);
1342 #endif
1343 
1344 	if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1345 		return (error);
1346 	if (lookup.version != sizeof(lookup) ||
1347 	    uap->cmd != KLDSYM_LOOKUP)
1348 		return (EINVAL);
1349 	symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1350 	if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1351 		goto out;
1352 	KLD_LOCK();
1353 	if (uap->fileid != 0) {
1354 		lf = linker_find_file_by_id(uap->fileid);
1355 		if (lf == NULL)
1356 			error = ENOENT;
1357 		else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1358 		    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1359 			lookup.symvalue = (uintptr_t) symval.value;
1360 			lookup.symsize = symval.size;
1361 			error = copyout(&lookup, uap->data, sizeof(lookup));
1362 		} else
1363 			error = ENOENT;
1364 	} else {
1365 		TAILQ_FOREACH(lf, &linker_files, link) {
1366 			if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1367 			    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1368 				lookup.symvalue = (uintptr_t)symval.value;
1369 				lookup.symsize = symval.size;
1370 				error = copyout(&lookup, uap->data,
1371 				    sizeof(lookup));
1372 				break;
1373 			}
1374 		}
1375 		if (lf == NULL)
1376 			error = ENOENT;
1377 	}
1378 	KLD_UNLOCK();
1379 out:
1380 	free(symstr, M_TEMP);
1381 	return (error);
1382 }
1383 
1384 /*
1385  * Preloaded module support
1386  */
1387 
1388 static modlist_t
1389 modlist_lookup(const char *name, int ver)
1390 {
1391 	modlist_t mod;
1392 
1393 	TAILQ_FOREACH(mod, &found_modules, link) {
1394 		if (strcmp(mod->name, name) == 0 &&
1395 		    (ver == 0 || mod->version == ver))
1396 			return (mod);
1397 	}
1398 	return (NULL);
1399 }
1400 
1401 static modlist_t
1402 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1403 {
1404 	modlist_t mod, bestmod;
1405 	int ver;
1406 
1407 	if (verinfo == NULL)
1408 		return (modlist_lookup(name, 0));
1409 	bestmod = NULL;
1410 	TAILQ_FOREACH(mod, &found_modules, link) {
1411 		if (strcmp(mod->name, name) != 0)
1412 			continue;
1413 		ver = mod->version;
1414 		if (ver == verinfo->md_ver_preferred)
1415 			return (mod);
1416 		if (ver >= verinfo->md_ver_minimum &&
1417 		    ver <= verinfo->md_ver_maximum &&
1418 		    (bestmod == NULL || ver > bestmod->version))
1419 			bestmod = mod;
1420 	}
1421 	return (bestmod);
1422 }
1423 
1424 static modlist_t
1425 modlist_newmodule(const char *modname, int version, linker_file_t container)
1426 {
1427 	modlist_t mod;
1428 
1429 	mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1430 	if (mod == NULL)
1431 		panic("no memory for module list");
1432 	mod->container = container;
1433 	mod->name = modname;
1434 	mod->version = version;
1435 	TAILQ_INSERT_TAIL(&found_modules, mod, link);
1436 	return (mod);
1437 }
1438 
1439 static void
1440 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1441     struct mod_metadata **stop, int preload)
1442 {
1443 	struct mod_metadata *mp, **mdp;
1444 	const char *modname;
1445 	int ver;
1446 
1447 	for (mdp = start; mdp < stop; mdp++) {
1448 		mp = *mdp;
1449 		if (mp->md_type != MDT_VERSION)
1450 			continue;
1451 		modname = mp->md_cval;
1452 		ver = ((struct mod_version *)mp->md_data)->mv_version;
1453 		if (modlist_lookup(modname, ver) != NULL) {
1454 			printf("module %s already present!\n", modname);
1455 			/* XXX what can we do? this is a build error. :-( */
1456 			continue;
1457 		}
1458 		modlist_newmodule(modname, ver, lf);
1459 	}
1460 }
1461 
1462 static void
1463 linker_preload(void *arg)
1464 {
1465 	caddr_t modptr;
1466 	const char *modname, *nmodname;
1467 	char *modtype;
1468 	linker_file_t lf, nlf;
1469 	linker_class_t lc;
1470 	int error;
1471 	linker_file_list_t loaded_files;
1472 	linker_file_list_t depended_files;
1473 	struct mod_metadata *mp, *nmp;
1474 	struct mod_metadata **start, **stop, **mdp, **nmdp;
1475 	struct mod_depend *verinfo;
1476 	int nver;
1477 	int resolves;
1478 	modlist_t mod;
1479 	struct sysinit **si_start, **si_stop;
1480 
1481 	TAILQ_INIT(&loaded_files);
1482 	TAILQ_INIT(&depended_files);
1483 	TAILQ_INIT(&found_modules);
1484 	error = 0;
1485 
1486 	modptr = NULL;
1487 	while ((modptr = preload_search_next_name(modptr)) != NULL) {
1488 		modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1489 		modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1490 		if (modname == NULL) {
1491 			printf("Preloaded module at %p does not have a"
1492 			    " name!\n", modptr);
1493 			continue;
1494 		}
1495 		if (modtype == NULL) {
1496 			printf("Preloaded module at %p does not have a type!\n",
1497 			    modptr);
1498 			continue;
1499 		}
1500 		if (bootverbose)
1501 			printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1502 			    modptr);
1503 		lf = NULL;
1504 		TAILQ_FOREACH(lc, &classes, link) {
1505 			error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1506 			if (!error)
1507 				break;
1508 			lf = NULL;
1509 		}
1510 		if (lf)
1511 			TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1512 	}
1513 
1514 	/*
1515 	 * First get a list of stuff in the kernel.
1516 	 */
1517 	if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1518 	    &stop, NULL) == 0)
1519 		linker_addmodules(linker_kernel_file, start, stop, 1);
1520 
1521 	/*
1522 	 * This is a once-off kinky bubble sort to resolve relocation
1523 	 * dependency requirements.
1524 	 */
1525 restart:
1526 	TAILQ_FOREACH(lf, &loaded_files, loaded) {
1527 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1528 		    &stop, NULL);
1529 		/*
1530 		 * First, look to see if we would successfully link with this
1531 		 * stuff.
1532 		 */
1533 		resolves = 1;	/* unless we know otherwise */
1534 		if (!error) {
1535 			for (mdp = start; mdp < stop; mdp++) {
1536 				mp = *mdp;
1537 				if (mp->md_type != MDT_DEPEND)
1538 					continue;
1539 				modname = mp->md_cval;
1540 				verinfo = mp->md_data;
1541 				for (nmdp = start; nmdp < stop; nmdp++) {
1542 					nmp = *nmdp;
1543 					if (nmp->md_type != MDT_VERSION)
1544 						continue;
1545 					nmodname = nmp->md_cval;
1546 					if (strcmp(modname, nmodname) == 0)
1547 						break;
1548 				}
1549 				if (nmdp < stop)   /* it's a self reference */
1550 					continue;
1551 
1552 				/*
1553 				 * ok, the module isn't here yet, we
1554 				 * are not finished
1555 				 */
1556 				if (modlist_lookup2(modname, verinfo) == NULL)
1557 					resolves = 0;
1558 			}
1559 		}
1560 		/*
1561 		 * OK, if we found our modules, we can link.  So, "provide"
1562 		 * the modules inside and add it to the end of the link order
1563 		 * list.
1564 		 */
1565 		if (resolves) {
1566 			if (!error) {
1567 				for (mdp = start; mdp < stop; mdp++) {
1568 					mp = *mdp;
1569 					if (mp->md_type != MDT_VERSION)
1570 						continue;
1571 					modname = mp->md_cval;
1572 					nver = ((struct mod_version *)
1573 					    mp->md_data)->mv_version;
1574 					if (modlist_lookup(modname,
1575 					    nver) != NULL) {
1576 						printf("module %s already"
1577 						    " present!\n", modname);
1578 						TAILQ_REMOVE(&loaded_files,
1579 						    lf, loaded);
1580 						linker_file_unload(lf,
1581 						    LINKER_UNLOAD_FORCE);
1582 						/* we changed tailq next ptr */
1583 						goto restart;
1584 					}
1585 					modlist_newmodule(modname, nver, lf);
1586 				}
1587 			}
1588 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1589 			TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1590 			/*
1591 			 * Since we provided modules, we need to restart the
1592 			 * sort so that the previous files that depend on us
1593 			 * have a chance. Also, we've busted the tailq next
1594 			 * pointer with the REMOVE.
1595 			 */
1596 			goto restart;
1597 		}
1598 	}
1599 
1600 	/*
1601 	 * At this point, we check to see what could not be resolved..
1602 	 */
1603 	while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1604 		TAILQ_REMOVE(&loaded_files, lf, loaded);
1605 		printf("KLD file %s is missing dependencies\n", lf->filename);
1606 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1607 	}
1608 
1609 	/*
1610 	 * We made it. Finish off the linking in the order we determined.
1611 	 */
1612 	TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1613 		if (linker_kernel_file) {
1614 			linker_kernel_file->refs++;
1615 			error = linker_file_add_dependency(lf,
1616 			    linker_kernel_file);
1617 			if (error)
1618 				panic("cannot add dependency");
1619 		}
1620 		lf->userrefs++;	/* so we can (try to) kldunload it */
1621 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1622 		    &stop, NULL);
1623 		if (!error) {
1624 			for (mdp = start; mdp < stop; mdp++) {
1625 				mp = *mdp;
1626 				if (mp->md_type != MDT_DEPEND)
1627 					continue;
1628 				modname = mp->md_cval;
1629 				verinfo = mp->md_data;
1630 				mod = modlist_lookup2(modname, verinfo);
1631 				if (mod == NULL) {
1632 					printf("KLD file %s - cannot find "
1633 					    "dependency \"%s\"\n",
1634 					    lf->filename, modname);
1635 					goto fail;
1636 				}
1637 				/* Don't count self-dependencies */
1638 				if (lf == mod->container)
1639 					continue;
1640 				mod->container->refs++;
1641 				error = linker_file_add_dependency(lf,
1642 				    mod->container);
1643 				if (error)
1644 					panic("cannot add dependency");
1645 			}
1646 		}
1647 		/*
1648 		 * Now do relocation etc using the symbol search paths
1649 		 * established by the dependencies
1650 		 */
1651 		error = LINKER_LINK_PRELOAD_FINISH(lf);
1652 		if (error) {
1653 			printf("KLD file %s - could not finalize loading\n",
1654 			    lf->filename);
1655 			goto fail;
1656 		}
1657 		linker_file_register_modules(lf);
1658 		if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1659 		    &si_stop, NULL) == 0)
1660 			sysinit_add(si_start, si_stop);
1661 		linker_file_register_sysctls(lf);
1662 		lf->flags |= LINKER_FILE_LINKED;
1663 		continue;
1664 fail:
1665 		TAILQ_REMOVE(&depended_files, lf, loaded);
1666 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1667 	}
1668 	/* woohoo! we made it! */
1669 }
1670 
1671 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1672 
1673 /*
1674  * Search for a not-loaded module by name.
1675  *
1676  * Modules may be found in the following locations:
1677  *
1678  * - preloaded (result is just the module name) - on disk (result is full path
1679  * to module)
1680  *
1681  * If the module name is qualified in any way (contains path, etc.) the we
1682  * simply return a copy of it.
1683  *
1684  * The search path can be manipulated via sysctl.  Note that we use the ';'
1685  * character as a separator to be consistent with the bootloader.
1686  */
1687 
1688 static char linker_hintfile[] = "linker.hints";
1689 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1690 
1691 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1692     sizeof(linker_path), "module load search path");
1693 
1694 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1695 
1696 static char *linker_ext_list[] = {
1697 	"",
1698 	".ko",
1699 	NULL
1700 };
1701 
1702 /*
1703  * Check if file actually exists either with or without extension listed in
1704  * the linker_ext_list. (probably should be generic for the rest of the
1705  * kernel)
1706  */
1707 static char *
1708 linker_lookup_file(const char *path, int pathlen, const char *name,
1709     int namelen, struct vattr *vap)
1710 {
1711 	struct nameidata nd;
1712 	struct thread *td = curthread;	/* XXX */
1713 	char *result, **cpp, *sep;
1714 	int error, len, extlen, reclen, flags;
1715 	enum vtype type;
1716 
1717 	extlen = 0;
1718 	for (cpp = linker_ext_list; *cpp; cpp++) {
1719 		len = strlen(*cpp);
1720 		if (len > extlen)
1721 			extlen = len;
1722 	}
1723 	extlen++;		/* trailing '\0' */
1724 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1725 
1726 	reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1727 	result = malloc(reclen, M_LINKER, M_WAITOK);
1728 	for (cpp = linker_ext_list; *cpp; cpp++) {
1729 		snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1730 		    namelen, name, *cpp);
1731 		/*
1732 		 * Attempt to open the file, and return the path if
1733 		 * we succeed and it's a regular file.
1734 		 */
1735 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1736 		flags = FREAD;
1737 		error = vn_open(&nd, &flags, 0, NULL);
1738 		if (error == 0) {
1739 			NDFREE(&nd, NDF_ONLY_PNBUF);
1740 			type = nd.ni_vp->v_type;
1741 			if (vap)
1742 				VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1743 			VOP_UNLOCK(nd.ni_vp, 0);
1744 			vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1745 			if (type == VREG)
1746 				return (result);
1747 		}
1748 	}
1749 	free(result, M_LINKER);
1750 	return (NULL);
1751 }
1752 
1753 #define	INT_ALIGN(base, ptr)	ptr =					\
1754 	(base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1755 
1756 /*
1757  * Lookup KLD which contains requested module in the "linker.hints" file. If
1758  * version specification is available, then try to find the best KLD.
1759  * Otherwise just find the latest one.
1760  */
1761 static char *
1762 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1763     int modnamelen, struct mod_depend *verinfo)
1764 {
1765 	struct thread *td = curthread;	/* XXX */
1766 	struct ucred *cred = td ? td->td_ucred : NULL;
1767 	struct nameidata nd;
1768 	struct vattr vattr, mattr;
1769 	u_char *hints = NULL;
1770 	u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1771 	int error, ival, bestver, *intp, found, flags, clen, blen;
1772 	ssize_t reclen;
1773 
1774 	result = NULL;
1775 	bestver = found = 0;
1776 
1777 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1778 	reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1779 	    strlen(sep) + 1;
1780 	pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1781 	snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1782 	    linker_hintfile);
1783 
1784 	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1785 	flags = FREAD;
1786 	error = vn_open(&nd, &flags, 0, NULL);
1787 	if (error)
1788 		goto bad;
1789 	NDFREE(&nd, NDF_ONLY_PNBUF);
1790 	if (nd.ni_vp->v_type != VREG)
1791 		goto bad;
1792 	best = cp = NULL;
1793 	error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1794 	if (error)
1795 		goto bad;
1796 	/*
1797 	 * XXX: we need to limit this number to some reasonable value
1798 	 */
1799 	if (vattr.va_size > 100 * 1024) {
1800 		printf("hints file too large %ld\n", (long)vattr.va_size);
1801 		goto bad;
1802 	}
1803 	hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1804 	if (hints == NULL)
1805 		goto bad;
1806 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1807 	    UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1808 	if (error)
1809 		goto bad;
1810 	VOP_UNLOCK(nd.ni_vp, 0);
1811 	vn_close(nd.ni_vp, FREAD, cred, td);
1812 	nd.ni_vp = NULL;
1813 	if (reclen != 0) {
1814 		printf("can't read %zd\n", reclen);
1815 		goto bad;
1816 	}
1817 	intp = (int *)hints;
1818 	ival = *intp++;
1819 	if (ival != LINKER_HINTS_VERSION) {
1820 		printf("hints file version mismatch %d\n", ival);
1821 		goto bad;
1822 	}
1823 	bufend = hints + vattr.va_size;
1824 	recptr = (u_char *)intp;
1825 	clen = blen = 0;
1826 	while (recptr < bufend && !found) {
1827 		intp = (int *)recptr;
1828 		reclen = *intp++;
1829 		ival = *intp++;
1830 		cp = (char *)intp;
1831 		switch (ival) {
1832 		case MDT_VERSION:
1833 			clen = *cp++;
1834 			if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1835 				break;
1836 			cp += clen;
1837 			INT_ALIGN(hints, cp);
1838 			ival = *(int *)cp;
1839 			cp += sizeof(int);
1840 			clen = *cp++;
1841 			if (verinfo == NULL ||
1842 			    ival == verinfo->md_ver_preferred) {
1843 				found = 1;
1844 				break;
1845 			}
1846 			if (ival >= verinfo->md_ver_minimum &&
1847 			    ival <= verinfo->md_ver_maximum &&
1848 			    ival > bestver) {
1849 				bestver = ival;
1850 				best = cp;
1851 				blen = clen;
1852 			}
1853 			break;
1854 		default:
1855 			break;
1856 		}
1857 		recptr += reclen + sizeof(int);
1858 	}
1859 	/*
1860 	 * Finally check if KLD is in the place
1861 	 */
1862 	if (found)
1863 		result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1864 	else if (best)
1865 		result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1866 
1867 	/*
1868 	 * KLD is newer than hints file. What we should do now?
1869 	 */
1870 	if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1871 		printf("warning: KLD '%s' is newer than the linker.hints"
1872 		    " file\n", result);
1873 bad:
1874 	free(pathbuf, M_LINKER);
1875 	if (hints)
1876 		free(hints, M_TEMP);
1877 	if (nd.ni_vp != NULL) {
1878 		VOP_UNLOCK(nd.ni_vp, 0);
1879 		vn_close(nd.ni_vp, FREAD, cred, td);
1880 	}
1881 	/*
1882 	 * If nothing found or hints is absent - fallback to the old
1883 	 * way by using "kldname[.ko]" as module name.
1884 	 */
1885 	if (!found && !bestver && result == NULL)
1886 		result = linker_lookup_file(path, pathlen, modname,
1887 		    modnamelen, NULL);
1888 	return (result);
1889 }
1890 
1891 /*
1892  * Lookup KLD which contains requested module in the all directories.
1893  */
1894 static char *
1895 linker_search_module(const char *modname, int modnamelen,
1896     struct mod_depend *verinfo)
1897 {
1898 	char *cp, *ep, *result;
1899 
1900 	/*
1901 	 * traverse the linker path
1902 	 */
1903 	for (cp = linker_path; *cp; cp = ep + 1) {
1904 		/* find the end of this component */
1905 		for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1906 		result = linker_hints_lookup(cp, ep - cp, modname,
1907 		    modnamelen, verinfo);
1908 		if (result != NULL)
1909 			return (result);
1910 		if (*ep == 0)
1911 			break;
1912 	}
1913 	return (NULL);
1914 }
1915 
1916 /*
1917  * Search for module in all directories listed in the linker_path.
1918  */
1919 static char *
1920 linker_search_kld(const char *name)
1921 {
1922 	char *cp, *ep, *result;
1923 	int len;
1924 
1925 	/* qualified at all? */
1926 	if (strchr(name, '/'))
1927 		return (linker_strdup(name));
1928 
1929 	/* traverse the linker path */
1930 	len = strlen(name);
1931 	for (ep = linker_path; *ep; ep++) {
1932 		cp = ep;
1933 		/* find the end of this component */
1934 		for (; *ep != 0 && *ep != ';'; ep++);
1935 		result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1936 		if (result != NULL)
1937 			return (result);
1938 	}
1939 	return (NULL);
1940 }
1941 
1942 static const char *
1943 linker_basename(const char *path)
1944 {
1945 	const char *filename;
1946 
1947 	filename = strrchr(path, '/');
1948 	if (filename == NULL)
1949 		return path;
1950 	if (filename[1])
1951 		filename++;
1952 	return (filename);
1953 }
1954 
1955 #ifdef HWPMC_HOOKS
1956 /*
1957  * Inform hwpmc about the set of kernel modules currently loaded.
1958  */
1959 void *
1960 linker_hwpmc_list_objects(void)
1961 {
1962 	linker_file_t lf;
1963 	struct pmckern_map_in *kobase;
1964 	int i, nmappings;
1965 
1966 	nmappings = 0;
1967 	KLD_LOCK_READ();
1968 	TAILQ_FOREACH(lf, &linker_files, link)
1969 		nmappings++;
1970 
1971 	/* Allocate nmappings + 1 entries. */
1972 	kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1973 	    M_LINKER, M_WAITOK | M_ZERO);
1974 	i = 0;
1975 	TAILQ_FOREACH(lf, &linker_files, link) {
1976 
1977 		/* Save the info for this linker file. */
1978 		kobase[i].pm_file = lf->filename;
1979 		kobase[i].pm_address = (uintptr_t)lf->address;
1980 		i++;
1981 	}
1982 	KLD_UNLOCK_READ();
1983 
1984 	KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
1985 
1986 	/* The last entry of the malloced area comprises of all zeros. */
1987 	KASSERT(kobase[i].pm_file == NULL,
1988 	    ("linker_hwpmc_list_objects: last object not NULL"));
1989 
1990 	return ((void *)kobase);
1991 }
1992 #endif
1993 
1994 /*
1995  * Find a file which contains given module and load it, if "parent" is not
1996  * NULL, register a reference to it.
1997  */
1998 static int
1999 linker_load_module(const char *kldname, const char *modname,
2000     struct linker_file *parent, struct mod_depend *verinfo,
2001     struct linker_file **lfpp)
2002 {
2003 	linker_file_t lfdep;
2004 	const char *filename;
2005 	char *pathname;
2006 	int error;
2007 
2008 	KLD_LOCK_ASSERT();
2009 	if (modname == NULL) {
2010 		/*
2011  		 * We have to load KLD
2012  		 */
2013 		KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
2014 		    " is not NULL"));
2015 		pathname = linker_search_kld(kldname);
2016 	} else {
2017 		if (modlist_lookup2(modname, verinfo) != NULL)
2018 			return (EEXIST);
2019 		if (kldname != NULL)
2020 			pathname = linker_strdup(kldname);
2021 		else if (rootvnode == NULL)
2022 			pathname = NULL;
2023 		else
2024 			/*
2025 			 * Need to find a KLD with required module
2026 			 */
2027 			pathname = linker_search_module(modname,
2028 			    strlen(modname), verinfo);
2029 	}
2030 	if (pathname == NULL)
2031 		return (ENOENT);
2032 
2033 	/*
2034 	 * Can't load more than one file with the same basename XXX:
2035 	 * Actually it should be possible to have multiple KLDs with
2036 	 * the same basename but different path because they can
2037 	 * provide different versions of the same modules.
2038 	 */
2039 	filename = linker_basename(pathname);
2040 	if (linker_find_file_by_name(filename))
2041 		error = EEXIST;
2042 	else do {
2043 		error = linker_load_file(pathname, &lfdep);
2044 		if (error)
2045 			break;
2046 		if (modname && verinfo &&
2047 		    modlist_lookup2(modname, verinfo) == NULL) {
2048 			linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2049 			error = ENOENT;
2050 			break;
2051 		}
2052 		if (parent) {
2053 			error = linker_file_add_dependency(parent, lfdep);
2054 			if (error)
2055 				break;
2056 		}
2057 		if (lfpp)
2058 			*lfpp = lfdep;
2059 	} while (0);
2060 	free(pathname, M_LINKER);
2061 	return (error);
2062 }
2063 
2064 /*
2065  * This routine is responsible for finding dependencies of userland initiated
2066  * kldload(2)'s of files.
2067  */
2068 int
2069 linker_load_dependencies(linker_file_t lf)
2070 {
2071 	linker_file_t lfdep;
2072 	struct mod_metadata **start, **stop, **mdp, **nmdp;
2073 	struct mod_metadata *mp, *nmp;
2074 	struct mod_depend *verinfo;
2075 	modlist_t mod;
2076 	const char *modname, *nmodname;
2077 	int ver, error = 0, count;
2078 
2079 	/*
2080 	 * All files are dependant on /kernel.
2081 	 */
2082 	KLD_LOCK_ASSERT();
2083 	if (linker_kernel_file) {
2084 		linker_kernel_file->refs++;
2085 		error = linker_file_add_dependency(lf, linker_kernel_file);
2086 		if (error)
2087 			return (error);
2088 	}
2089 	if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2090 	    &count) != 0)
2091 		return (0);
2092 	for (mdp = start; mdp < stop; mdp++) {
2093 		mp = *mdp;
2094 		if (mp->md_type != MDT_VERSION)
2095 			continue;
2096 		modname = mp->md_cval;
2097 		ver = ((struct mod_version *)mp->md_data)->mv_version;
2098 		mod = modlist_lookup(modname, ver);
2099 		if (mod != NULL) {
2100 			printf("interface %s.%d already present in the KLD"
2101 			    " '%s'!\n", modname, ver,
2102 			    mod->container->filename);
2103 			return (EEXIST);
2104 		}
2105 	}
2106 
2107 	for (mdp = start; mdp < stop; mdp++) {
2108 		mp = *mdp;
2109 		if (mp->md_type != MDT_DEPEND)
2110 			continue;
2111 		modname = mp->md_cval;
2112 		verinfo = mp->md_data;
2113 		nmodname = NULL;
2114 		for (nmdp = start; nmdp < stop; nmdp++) {
2115 			nmp = *nmdp;
2116 			if (nmp->md_type != MDT_VERSION)
2117 				continue;
2118 			nmodname = nmp->md_cval;
2119 			if (strcmp(modname, nmodname) == 0)
2120 				break;
2121 		}
2122 		if (nmdp < stop)/* early exit, it's a self reference */
2123 			continue;
2124 		mod = modlist_lookup2(modname, verinfo);
2125 		if (mod) {	/* woohoo, it's loaded already */
2126 			lfdep = mod->container;
2127 			lfdep->refs++;
2128 			error = linker_file_add_dependency(lf, lfdep);
2129 			if (error)
2130 				break;
2131 			continue;
2132 		}
2133 		error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2134 		if (error) {
2135 			printf("KLD %s: depends on %s - not available or"
2136 			    " version mismatch\n", lf->filename, modname);
2137 			break;
2138 		}
2139 	}
2140 
2141 	if (error)
2142 		return (error);
2143 	linker_addmodules(lf, start, stop, 0);
2144 	return (error);
2145 }
2146 
2147 static int
2148 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2149 {
2150 	struct sysctl_req *req;
2151 
2152 	req = opaque;
2153 	return (SYSCTL_OUT(req, name, strlen(name) + 1));
2154 }
2155 
2156 /*
2157  * Export a nul-separated, double-nul-terminated list of all function names
2158  * in the kernel.
2159  */
2160 static int
2161 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2162 {
2163 	linker_file_t lf;
2164 	int error;
2165 
2166 #ifdef MAC
2167 	error = mac_kld_check_stat(req->td->td_ucred);
2168 	if (error)
2169 		return (error);
2170 #endif
2171 	error = sysctl_wire_old_buffer(req, 0);
2172 	if (error != 0)
2173 		return (error);
2174 	KLD_LOCK();
2175 	TAILQ_FOREACH(lf, &linker_files, link) {
2176 		error = LINKER_EACH_FUNCTION_NAME(lf,
2177 		    sysctl_kern_function_list_iterate, req);
2178 		if (error) {
2179 			KLD_UNLOCK();
2180 			return (error);
2181 		}
2182 	}
2183 	KLD_UNLOCK();
2184 	return (SYSCTL_OUT(req, "", 1));
2185 }
2186 
2187 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2188     NULL, 0, sysctl_kern_function_list, "", "kernel function list");
2189