xref: /freebsd/sys/kern/kern_linker.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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 #ifdef DDB
58 #include <ddb/ddb.h>
59 #endif
60 
61 #include <net/vnet.h>
62 
63 #include <security/mac/mac_framework.h>
64 
65 #include "linker_if.h"
66 
67 #ifdef HWPMC_HOOKS
68 #include <sys/pmckern.h>
69 #endif
70 
71 #ifdef KLD_DEBUG
72 int kld_debug = 0;
73 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RWTUN,
74     &kld_debug, 0, "Set various levels of KLD debug");
75 #endif
76 
77 /* These variables are used by kernel debuggers to enumerate loaded files. */
78 const int kld_off_address = offsetof(struct linker_file, address);
79 const int kld_off_filename = offsetof(struct linker_file, filename);
80 const int kld_off_pathname = offsetof(struct linker_file, pathname);
81 const int kld_off_next = offsetof(struct linker_file, link.tqe_next);
82 
83 /*
84  * static char *linker_search_path(const char *name, struct mod_depend
85  * *verinfo);
86  */
87 static const char 	*linker_basename(const char *path);
88 
89 /*
90  * Find a currently loaded file given its filename.
91  */
92 static linker_file_t linker_find_file_by_name(const char* _filename);
93 
94 /*
95  * Find a currently loaded file given its file id.
96  */
97 static linker_file_t linker_find_file_by_id(int _fileid);
98 
99 /* Metadata from the static kernel */
100 SET_DECLARE(modmetadata_set, struct mod_metadata);
101 
102 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
103 
104 linker_file_t linker_kernel_file;
105 
106 static struct sx kld_sx;	/* kernel linker lock */
107 
108 /*
109  * Load counter used by clients to determine if a linker file has been
110  * re-loaded. This counter is incremented for each file load.
111  */
112 static int loadcnt;
113 
114 static linker_class_list_t classes;
115 static linker_file_list_t linker_files;
116 static int next_file_id = 1;
117 static int linker_no_more_classes = 0;
118 
119 #define	LINKER_GET_NEXT_FILE_ID(a) do {					\
120 	linker_file_t lftmp;						\
121 									\
122 	if (!cold)							\
123 		sx_assert(&kld_sx, SA_XLOCKED);				\
124 retry:									\
125 	TAILQ_FOREACH(lftmp, &linker_files, link) {			\
126 		if (next_file_id == lftmp->id) {			\
127 			next_file_id++;					\
128 			goto retry;					\
129 		}							\
130 	}								\
131 	(a) = next_file_id;						\
132 } while(0)
133 
134 
135 /* XXX wrong name; we're looking at version provision tags here, not modules */
136 typedef TAILQ_HEAD(, modlist) modlisthead_t;
137 struct modlist {
138 	TAILQ_ENTRY(modlist) link;	/* chain together all modules */
139 	linker_file_t   container;
140 	const char 	*name;
141 	int             version;
142 };
143 typedef struct modlist *modlist_t;
144 static modlisthead_t found_modules;
145 
146 static int	linker_file_add_dependency(linker_file_t file,
147 		    linker_file_t dep);
148 static caddr_t	linker_file_lookup_symbol_internal(linker_file_t file,
149 		    const char* name, int deps);
150 static int	linker_load_module(const char *kldname,
151 		    const char *modname, struct linker_file *parent,
152 		    const struct mod_depend *verinfo, struct linker_file **lfpp);
153 static modlist_t modlist_lookup2(const char *name, const struct mod_depend *verinfo);
154 
155 static void
156 linker_init(void *arg)
157 {
158 
159 	sx_init(&kld_sx, "kernel linker");
160 	TAILQ_INIT(&classes);
161 	TAILQ_INIT(&linker_files);
162 }
163 
164 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
165 
166 static void
167 linker_stop_class_add(void *arg)
168 {
169 
170 	linker_no_more_classes = 1;
171 }
172 
173 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
174 
175 int
176 linker_add_class(linker_class_t lc)
177 {
178 
179 	/*
180 	 * We disallow any class registration past SI_ORDER_ANY
181 	 * of SI_SUB_KLD.  We bump the reference count to keep the
182 	 * ops from being freed.
183 	 */
184 	if (linker_no_more_classes == 1)
185 		return (EPERM);
186 	kobj_class_compile((kobj_class_t) lc);
187 	((kobj_class_t)lc)->refs++;	/* XXX: kobj_mtx */
188 	TAILQ_INSERT_TAIL(&classes, lc, link);
189 	return (0);
190 }
191 
192 static void
193 linker_file_sysinit(linker_file_t lf)
194 {
195 	struct sysinit **start, **stop, **sipp, **xipp, *save;
196 
197 	KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
198 	    lf->filename));
199 
200 	sx_assert(&kld_sx, SA_XLOCKED);
201 
202 	if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
203 		return;
204 	/*
205 	 * Perform a bubble sort of the system initialization objects by
206 	 * their subsystem (primary key) and order (secondary key).
207 	 *
208 	 * Since some things care about execution order, this is the operation
209 	 * which ensures continued function.
210 	 */
211 	for (sipp = start; sipp < stop; sipp++) {
212 		for (xipp = sipp + 1; xipp < stop; xipp++) {
213 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
214 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
215 			    (*sipp)->order <= (*xipp)->order))
216 				continue;	/* skip */
217 			save = *sipp;
218 			*sipp = *xipp;
219 			*xipp = save;
220 		}
221 	}
222 
223 	/*
224 	 * Traverse the (now) ordered list of system initialization tasks.
225 	 * Perform each task, and continue on to the next task.
226 	 */
227 	sx_xunlock(&kld_sx);
228 	mtx_lock(&Giant);
229 	for (sipp = start; sipp < stop; sipp++) {
230 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
231 			continue;	/* skip dummy task(s) */
232 
233 		/* Call function */
234 		(*((*sipp)->func)) ((*sipp)->udata);
235 	}
236 	mtx_unlock(&Giant);
237 	sx_xlock(&kld_sx);
238 }
239 
240 static void
241 linker_file_sysuninit(linker_file_t lf)
242 {
243 	struct sysinit **start, **stop, **sipp, **xipp, *save;
244 
245 	KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
246 	    lf->filename));
247 
248 	sx_assert(&kld_sx, SA_XLOCKED);
249 
250 	if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
251 	    NULL) != 0)
252 		return;
253 
254 	/*
255 	 * Perform a reverse bubble sort of the system initialization objects
256 	 * by their subsystem (primary key) and order (secondary key).
257 	 *
258 	 * Since some things care about execution order, this is the operation
259 	 * which ensures continued function.
260 	 */
261 	for (sipp = start; sipp < stop; sipp++) {
262 		for (xipp = sipp + 1; xipp < stop; xipp++) {
263 			if ((*sipp)->subsystem > (*xipp)->subsystem ||
264 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
265 			    (*sipp)->order >= (*xipp)->order))
266 				continue;	/* skip */
267 			save = *sipp;
268 			*sipp = *xipp;
269 			*xipp = save;
270 		}
271 	}
272 
273 	/*
274 	 * Traverse the (now) ordered list of system initialization tasks.
275 	 * Perform each task, and continue on to the next task.
276 	 */
277 	sx_xunlock(&kld_sx);
278 	mtx_lock(&Giant);
279 	for (sipp = start; sipp < stop; sipp++) {
280 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
281 			continue;	/* skip dummy task(s) */
282 
283 		/* Call function */
284 		(*((*sipp)->func)) ((*sipp)->udata);
285 	}
286 	mtx_unlock(&Giant);
287 	sx_xlock(&kld_sx);
288 }
289 
290 static void
291 linker_file_register_sysctls(linker_file_t lf)
292 {
293 	struct sysctl_oid **start, **stop, **oidp;
294 
295 	KLD_DPF(FILE,
296 	    ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
297 	    lf->filename));
298 
299 	sx_assert(&kld_sx, SA_XLOCKED);
300 
301 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
302 		return;
303 
304 	sx_xunlock(&kld_sx);
305 	sysctl_wlock();
306 	for (oidp = start; oidp < stop; oidp++)
307 		sysctl_register_oid(*oidp);
308 	sysctl_wunlock();
309 	sx_xlock(&kld_sx);
310 }
311 
312 static void
313 linker_file_unregister_sysctls(linker_file_t lf)
314 {
315 	struct sysctl_oid **start, **stop, **oidp;
316 
317 	KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
318 	    " for %s\n", lf->filename));
319 
320 	sx_assert(&kld_sx, SA_XLOCKED);
321 
322 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
323 		return;
324 
325 	sx_xunlock(&kld_sx);
326 	sysctl_wlock();
327 	for (oidp = start; oidp < stop; oidp++)
328 		sysctl_unregister_oid(*oidp);
329 	sysctl_wunlock();
330 	sx_xlock(&kld_sx);
331 }
332 
333 static int
334 linker_file_register_modules(linker_file_t lf)
335 {
336 	struct mod_metadata **start, **stop, **mdp;
337 	const moduledata_t *moddata;
338 	int first_error, error;
339 
340 	KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
341 	    " in %s\n", lf->filename));
342 
343 	sx_assert(&kld_sx, SA_XLOCKED);
344 
345 	if (linker_file_lookup_set(lf, "modmetadata_set", &start,
346 	    &stop, NULL) != 0) {
347 		/*
348 		 * This fallback should be unnecessary, but if we get booted
349 		 * from boot2 instead of loader and we are missing our
350 		 * metadata then we have to try the best we can.
351 		 */
352 		if (lf == linker_kernel_file) {
353 			start = SET_BEGIN(modmetadata_set);
354 			stop = SET_LIMIT(modmetadata_set);
355 		} else
356 			return (0);
357 	}
358 	first_error = 0;
359 	for (mdp = start; mdp < stop; mdp++) {
360 		if ((*mdp)->md_type != MDT_MODULE)
361 			continue;
362 		moddata = (*mdp)->md_data;
363 		KLD_DPF(FILE, ("Registering module %s in %s\n",
364 		    moddata->name, lf->filename));
365 		error = module_register(moddata, lf);
366 		if (error) {
367 			printf("Module %s failed to register: %d\n",
368 			    moddata->name, error);
369 			if (first_error == 0)
370 				first_error = error;
371 		}
372 	}
373 	return (first_error);
374 }
375 
376 static void
377 linker_init_kernel_modules(void)
378 {
379 
380 	sx_xlock(&kld_sx);
381 	linker_file_register_modules(linker_kernel_file);
382 	sx_xunlock(&kld_sx);
383 }
384 
385 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
386     0);
387 
388 static int
389 linker_load_file(const char *filename, linker_file_t *result)
390 {
391 	linker_class_t lc;
392 	linker_file_t lf;
393 	int foundfile, error, modules;
394 
395 	/* Refuse to load modules if securelevel raised */
396 	if (prison0.pr_securelevel > 0)
397 		return (EPERM);
398 
399 	sx_assert(&kld_sx, SA_XLOCKED);
400 	lf = linker_find_file_by_name(filename);
401 	if (lf) {
402 		KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
403 		    " incrementing refs\n", filename));
404 		*result = lf;
405 		lf->refs++;
406 		return (0);
407 	}
408 	foundfile = 0;
409 	error = 0;
410 
411 	/*
412 	 * We do not need to protect (lock) classes here because there is
413 	 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
414 	 * and there is no class deregistration mechanism at this time.
415 	 */
416 	TAILQ_FOREACH(lc, &classes, link) {
417 		KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
418 		    filename));
419 		error = LINKER_LOAD_FILE(lc, filename, &lf);
420 		/*
421 		 * If we got something other than ENOENT, then it exists but
422 		 * we cannot load it for some other reason.
423 		 */
424 		if (error != ENOENT)
425 			foundfile = 1;
426 		if (lf) {
427 			error = linker_file_register_modules(lf);
428 			if (error == EEXIST) {
429 				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
430 				return (error);
431 			}
432 			modules = !TAILQ_EMPTY(&lf->modules);
433 			linker_file_register_sysctls(lf);
434 			linker_file_sysinit(lf);
435 			lf->flags |= LINKER_FILE_LINKED;
436 
437 			/*
438 			 * If all of the modules in this file failed
439 			 * to load, unload the file and return an
440 			 * error of ENOEXEC.
441 			 */
442 			if (modules && TAILQ_EMPTY(&lf->modules)) {
443 				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
444 				return (ENOEXEC);
445 			}
446 			EVENTHANDLER_INVOKE(kld_load, lf);
447 			*result = lf;
448 			return (0);
449 		}
450 	}
451 	/*
452 	 * Less than ideal, but tells the user whether it failed to load or
453 	 * the module was not found.
454 	 */
455 	if (foundfile) {
456 
457 		/*
458 		 * If the file type has not been recognized by the last try
459 		 * printout a message before to fail.
460 		 */
461 		if (error == ENOSYS)
462 			printf("linker_load_file: Unsupported file type\n");
463 
464 		/*
465 		 * Format not recognized or otherwise unloadable.
466 		 * When loading a module that is statically built into
467 		 * the kernel EEXIST percolates back up as the return
468 		 * value.  Preserve this so that apps like sysinstall
469 		 * can recognize this special case and not post bogus
470 		 * dialog boxes.
471 		 */
472 		if (error != EEXIST)
473 			error = ENOEXEC;
474 	} else
475 		error = ENOENT;		/* Nothing found */
476 	return (error);
477 }
478 
479 int
480 linker_reference_module(const char *modname, struct mod_depend *verinfo,
481     linker_file_t *result)
482 {
483 	modlist_t mod;
484 	int error;
485 
486 	sx_xlock(&kld_sx);
487 	if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
488 		*result = mod->container;
489 		(*result)->refs++;
490 		sx_xunlock(&kld_sx);
491 		return (0);
492 	}
493 
494 	error = linker_load_module(NULL, modname, NULL, verinfo, result);
495 	sx_xunlock(&kld_sx);
496 	return (error);
497 }
498 
499 int
500 linker_release_module(const char *modname, struct mod_depend *verinfo,
501     linker_file_t lf)
502 {
503 	modlist_t mod;
504 	int error;
505 
506 	sx_xlock(&kld_sx);
507 	if (lf == NULL) {
508 		KASSERT(modname != NULL,
509 		    ("linker_release_module: no file or name"));
510 		mod = modlist_lookup2(modname, verinfo);
511 		if (mod == NULL) {
512 			sx_xunlock(&kld_sx);
513 			return (ESRCH);
514 		}
515 		lf = mod->container;
516 	} else
517 		KASSERT(modname == NULL && verinfo == NULL,
518 		    ("linker_release_module: both file and name"));
519 	error =	linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
520 	sx_xunlock(&kld_sx);
521 	return (error);
522 }
523 
524 static linker_file_t
525 linker_find_file_by_name(const char *filename)
526 {
527 	linker_file_t lf;
528 	char *koname;
529 
530 	koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
531 	sprintf(koname, "%s.ko", filename);
532 
533 	sx_assert(&kld_sx, SA_XLOCKED);
534 	TAILQ_FOREACH(lf, &linker_files, link) {
535 		if (strcmp(lf->filename, koname) == 0)
536 			break;
537 		if (strcmp(lf->filename, filename) == 0)
538 			break;
539 	}
540 	free(koname, M_LINKER);
541 	return (lf);
542 }
543 
544 static linker_file_t
545 linker_find_file_by_id(int fileid)
546 {
547 	linker_file_t lf;
548 
549 	sx_assert(&kld_sx, SA_XLOCKED);
550 	TAILQ_FOREACH(lf, &linker_files, link)
551 		if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
552 			break;
553 	return (lf);
554 }
555 
556 int
557 linker_file_foreach(linker_predicate_t *predicate, void *context)
558 {
559 	linker_file_t lf;
560 	int retval = 0;
561 
562 	sx_xlock(&kld_sx);
563 	TAILQ_FOREACH(lf, &linker_files, link) {
564 		retval = predicate(lf, context);
565 		if (retval != 0)
566 			break;
567 	}
568 	sx_xunlock(&kld_sx);
569 	return (retval);
570 }
571 
572 linker_file_t
573 linker_make_file(const char *pathname, linker_class_t lc)
574 {
575 	linker_file_t lf;
576 	const char *filename;
577 
578 	if (!cold)
579 		sx_assert(&kld_sx, SA_XLOCKED);
580 	filename = linker_basename(pathname);
581 
582 	KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
583 	lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
584 	if (lf == NULL)
585 		return (NULL);
586 	lf->ctors_addr = 0;
587 	lf->ctors_size = 0;
588 	lf->refs = 1;
589 	lf->userrefs = 0;
590 	lf->flags = 0;
591 	lf->filename = strdup(filename, M_LINKER);
592 	lf->pathname = strdup(pathname, M_LINKER);
593 	LINKER_GET_NEXT_FILE_ID(lf->id);
594 	lf->ndeps = 0;
595 	lf->deps = NULL;
596 	lf->loadcnt = ++loadcnt;
597 	STAILQ_INIT(&lf->common);
598 	TAILQ_INIT(&lf->modules);
599 	TAILQ_INSERT_TAIL(&linker_files, lf, link);
600 	return (lf);
601 }
602 
603 int
604 linker_file_unload(linker_file_t file, int flags)
605 {
606 	module_t mod, next;
607 	modlist_t ml, nextml;
608 	struct common_symbol *cp;
609 	int error, i;
610 
611 	/* Refuse to unload modules if securelevel raised. */
612 	if (prison0.pr_securelevel > 0)
613 		return (EPERM);
614 
615 	sx_assert(&kld_sx, SA_XLOCKED);
616 	KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
617 
618 	/* Easy case of just dropping a reference. */
619 	if (file->refs > 1) {
620 		file->refs--;
621 		return (0);
622 	}
623 
624 	/* Give eventhandlers a chance to prevent the unload. */
625 	error = 0;
626 	EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
627 	if (error != 0)
628 		return (EBUSY);
629 
630 	KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
631 	    " informing modules\n"));
632 
633 	/*
634 	 * Quiesce all the modules to give them a chance to veto the unload.
635 	 */
636 	MOD_SLOCK;
637 	for (mod = TAILQ_FIRST(&file->modules); mod;
638 	     mod = module_getfnext(mod)) {
639 
640 		error = module_quiesce(mod);
641 		if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
642 			KLD_DPF(FILE, ("linker_file_unload: module %s"
643 			    " vetoed unload\n", module_getname(mod)));
644 			/*
645 			 * XXX: Do we need to tell all the quiesced modules
646 			 * that they can resume work now via a new module
647 			 * event?
648 			 */
649 			MOD_SUNLOCK;
650 			return (error);
651 		}
652 	}
653 	MOD_SUNLOCK;
654 
655 	/*
656 	 * Inform any modules associated with this file that they are
657 	 * being unloaded.
658 	 */
659 	MOD_XLOCK;
660 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
661 		next = module_getfnext(mod);
662 		MOD_XUNLOCK;
663 
664 		/*
665 		 * Give the module a chance to veto the unload.
666 		 */
667 		if ((error = module_unload(mod)) != 0) {
668 #ifdef KLD_DEBUG
669 			MOD_SLOCK;
670 			KLD_DPF(FILE, ("linker_file_unload: module %s"
671 			    " failed unload\n", module_getname(mod)));
672 			MOD_SUNLOCK;
673 #endif
674 			return (error);
675 		}
676 		MOD_XLOCK;
677 		module_release(mod);
678 	}
679 	MOD_XUNLOCK;
680 
681 	TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
682 		if (ml->container == file) {
683 			TAILQ_REMOVE(&found_modules, ml, link);
684 			free(ml, M_LINKER);
685 		}
686 	}
687 
688 	/*
689 	 * Don't try to run SYSUNINITs if we are unloaded due to a
690 	 * link error.
691 	 */
692 	if (file->flags & LINKER_FILE_LINKED) {
693 		file->flags &= ~LINKER_FILE_LINKED;
694 		linker_file_sysuninit(file);
695 		linker_file_unregister_sysctls(file);
696 	}
697 	TAILQ_REMOVE(&linker_files, file, link);
698 
699 	if (file->deps) {
700 		for (i = 0; i < file->ndeps; i++)
701 			linker_file_unload(file->deps[i], flags);
702 		free(file->deps, M_LINKER);
703 		file->deps = NULL;
704 	}
705 	while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
706 		STAILQ_REMOVE_HEAD(&file->common, link);
707 		free(cp, M_LINKER);
708 	}
709 
710 	LINKER_UNLOAD(file);
711 
712 	EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
713 	    file->size);
714 
715 	if (file->filename) {
716 		free(file->filename, M_LINKER);
717 		file->filename = NULL;
718 	}
719 	if (file->pathname) {
720 		free(file->pathname, M_LINKER);
721 		file->pathname = NULL;
722 	}
723 	kobj_delete((kobj_t) file, M_LINKER);
724 	return (0);
725 }
726 
727 int
728 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
729 {
730 	return (LINKER_CTF_GET(file, lc));
731 }
732 
733 static int
734 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
735 {
736 	linker_file_t *newdeps;
737 
738 	sx_assert(&kld_sx, SA_XLOCKED);
739 	file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
740 	    M_LINKER, M_WAITOK | M_ZERO);
741 	file->deps[file->ndeps] = dep;
742 	file->ndeps++;
743 	KLD_DPF(FILE, ("linker_file_add_dependency:"
744 	    " adding %s as dependency for %s\n",
745 	    dep->filename, file->filename));
746 	return (0);
747 }
748 
749 /*
750  * Locate a linker set and its contents.  This is a helper function to avoid
751  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
752  * This function is used in this file so we can avoid having lots of (void **)
753  * casts.
754  */
755 int
756 linker_file_lookup_set(linker_file_t file, const char *name,
757     void *firstp, void *lastp, int *countp)
758 {
759 
760 	sx_assert(&kld_sx, SA_LOCKED);
761 	return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
762 }
763 
764 /*
765  * List all functions in a file.
766  */
767 int
768 linker_file_function_listall(linker_file_t lf,
769     linker_function_nameval_callback_t callback_func, void *arg)
770 {
771 	return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
772 }
773 
774 caddr_t
775 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
776 {
777 	caddr_t sym;
778 	int locked;
779 
780 	locked = sx_xlocked(&kld_sx);
781 	if (!locked)
782 		sx_xlock(&kld_sx);
783 	sym = linker_file_lookup_symbol_internal(file, name, deps);
784 	if (!locked)
785 		sx_xunlock(&kld_sx);
786 	return (sym);
787 }
788 
789 static caddr_t
790 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
791     int deps)
792 {
793 	c_linker_sym_t sym;
794 	linker_symval_t symval;
795 	caddr_t address;
796 	size_t common_size = 0;
797 	int i;
798 
799 	sx_assert(&kld_sx, SA_XLOCKED);
800 	KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
801 	    file, name, deps));
802 
803 	if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
804 		LINKER_SYMBOL_VALUES(file, sym, &symval);
805 		if (symval.value == 0)
806 			/*
807 			 * For commons, first look them up in the
808 			 * dependencies and only allocate space if not found
809 			 * there.
810 			 */
811 			common_size = symval.size;
812 		else {
813 			KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
814 			    ".value=%p\n", symval.value));
815 			return (symval.value);
816 		}
817 	}
818 	if (deps) {
819 		for (i = 0; i < file->ndeps; i++) {
820 			address = linker_file_lookup_symbol_internal(
821 			    file->deps[i], name, 0);
822 			if (address) {
823 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
824 				    " deps value=%p\n", address));
825 				return (address);
826 			}
827 		}
828 	}
829 	if (common_size > 0) {
830 		/*
831 		 * This is a common symbol which was not found in the
832 		 * dependencies.  We maintain a simple common symbol table in
833 		 * the file object.
834 		 */
835 		struct common_symbol *cp;
836 
837 		STAILQ_FOREACH(cp, &file->common, link) {
838 			if (strcmp(cp->name, name) == 0) {
839 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
840 				    " old common value=%p\n", cp->address));
841 				return (cp->address);
842 			}
843 		}
844 		/*
845 		 * Round the symbol size up to align.
846 		 */
847 		common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
848 		cp = malloc(sizeof(struct common_symbol)
849 		    + common_size + strlen(name) + 1, M_LINKER,
850 		    M_WAITOK | M_ZERO);
851 		cp->address = (caddr_t)(cp + 1);
852 		cp->name = cp->address + common_size;
853 		strcpy(cp->name, name);
854 		bzero(cp->address, common_size);
855 		STAILQ_INSERT_TAIL(&file->common, cp, link);
856 
857 		KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
858 		    " value=%p\n", cp->address));
859 		return (cp->address);
860 	}
861 	KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
862 	return (0);
863 }
864 
865 /*
866  * Both DDB and stack(9) rely on the kernel linker to provide forward and
867  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
868  * do this in a lockfree manner.  We provide a set of internal helper
869  * routines to perform these operations without locks, and then wrappers that
870  * optionally lock.
871  *
872  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
873  */
874 #ifdef DDB
875 static int
876 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
877 {
878 	linker_file_t lf;
879 
880 	TAILQ_FOREACH(lf, &linker_files, link) {
881 		if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
882 			return (0);
883 	}
884 	return (ENOENT);
885 }
886 #endif
887 
888 static int
889 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
890 {
891 	linker_file_t lf;
892 	c_linker_sym_t best, es;
893 	u_long diff, bestdiff, off;
894 
895 	best = 0;
896 	off = (uintptr_t)value;
897 	bestdiff = off;
898 	TAILQ_FOREACH(lf, &linker_files, link) {
899 		if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
900 			continue;
901 		if (es != 0 && diff < bestdiff) {
902 			best = es;
903 			bestdiff = diff;
904 		}
905 		if (bestdiff == 0)
906 			break;
907 	}
908 	if (best) {
909 		*sym = best;
910 		*diffp = bestdiff;
911 		return (0);
912 	} else {
913 		*sym = 0;
914 		*diffp = off;
915 		return (ENOENT);
916 	}
917 }
918 
919 static int
920 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
921 {
922 	linker_file_t lf;
923 
924 	TAILQ_FOREACH(lf, &linker_files, link) {
925 		if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
926 			return (0);
927 	}
928 	return (ENOENT);
929 }
930 
931 static int
932 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
933     long *offset)
934 {
935 	linker_symval_t symval;
936 	c_linker_sym_t sym;
937 	int error;
938 
939 	*offset = 0;
940 	error = linker_debug_search_symbol(value, &sym, offset);
941 	if (error)
942 		return (error);
943 	error = linker_debug_symbol_values(sym, &symval);
944 	if (error)
945 		return (error);
946 	strlcpy(buf, symval.name, buflen);
947 	return (0);
948 }
949 
950 /*
951  * DDB Helpers.  DDB has to look across multiple files with their own symbol
952  * tables and string tables.
953  *
954  * Note that we do not obey list locking protocols here.  We really don't need
955  * DDB to hang because somebody's got the lock held.  We'll take the chance
956  * that the files list is inconsistent instead.
957  */
958 #ifdef DDB
959 int
960 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
961 {
962 
963 	return (linker_debug_lookup(symstr, sym));
964 }
965 #endif
966 
967 int
968 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
969 {
970 
971 	return (linker_debug_search_symbol(value, sym, diffp));
972 }
973 
974 int
975 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
976 {
977 
978 	return (linker_debug_symbol_values(sym, symval));
979 }
980 
981 int
982 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
983     long *offset)
984 {
985 
986 	return (linker_debug_search_symbol_name(value, buf, buflen, offset));
987 }
988 
989 /*
990  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
991  * obey locking protocols, and offer a significantly less complex interface.
992  */
993 int
994 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
995     long *offset)
996 {
997 	int error;
998 
999 	sx_slock(&kld_sx);
1000 	error = linker_debug_search_symbol_name(value, buf, buflen, offset);
1001 	sx_sunlock(&kld_sx);
1002 	return (error);
1003 }
1004 
1005 /*
1006  * Syscalls.
1007  */
1008 int
1009 kern_kldload(struct thread *td, const char *file, int *fileid)
1010 {
1011 	const char *kldname, *modname;
1012 	linker_file_t lf;
1013 	int error;
1014 
1015 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1016 		return (error);
1017 
1018 	if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1019 		return (error);
1020 
1021 	/*
1022 	 * It is possible that kldloaded module will attach a new ifnet,
1023 	 * so vnet context must be set when this ocurs.
1024 	 */
1025 	CURVNET_SET(TD_TO_VNET(td));
1026 
1027 	/*
1028 	 * If file does not contain a qualified name or any dot in it
1029 	 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1030 	 * name.
1031 	 */
1032 	if (strchr(file, '/') || strchr(file, '.')) {
1033 		kldname = file;
1034 		modname = NULL;
1035 	} else {
1036 		kldname = NULL;
1037 		modname = file;
1038 	}
1039 
1040 	sx_xlock(&kld_sx);
1041 	error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1042 	if (error) {
1043 		sx_xunlock(&kld_sx);
1044 		goto done;
1045 	}
1046 	lf->userrefs++;
1047 	if (fileid != NULL)
1048 		*fileid = lf->id;
1049 	sx_xunlock(&kld_sx);
1050 
1051 done:
1052 	CURVNET_RESTORE();
1053 	return (error);
1054 }
1055 
1056 int
1057 sys_kldload(struct thread *td, struct kldload_args *uap)
1058 {
1059 	char *pathname = NULL;
1060 	int error, fileid;
1061 
1062 	td->td_retval[0] = -1;
1063 
1064 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1065 	error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1066 	if (error == 0) {
1067 		error = kern_kldload(td, pathname, &fileid);
1068 		if (error == 0)
1069 			td->td_retval[0] = fileid;
1070 	}
1071 	free(pathname, M_TEMP);
1072 	return (error);
1073 }
1074 
1075 int
1076 kern_kldunload(struct thread *td, int fileid, int flags)
1077 {
1078 	linker_file_t lf;
1079 	int error = 0;
1080 
1081 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1082 		return (error);
1083 
1084 	if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1085 		return (error);
1086 
1087 	CURVNET_SET(TD_TO_VNET(td));
1088 	sx_xlock(&kld_sx);
1089 	lf = linker_find_file_by_id(fileid);
1090 	if (lf) {
1091 		KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1092 
1093 		if (lf->userrefs == 0) {
1094 			/*
1095 			 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1096 			 */
1097 			printf("kldunload: attempt to unload file that was"
1098 			    " loaded by the kernel\n");
1099 			error = EBUSY;
1100 		} else {
1101 			lf->userrefs--;
1102 			error = linker_file_unload(lf, flags);
1103 			if (error)
1104 				lf->userrefs++;
1105 		}
1106 	} else
1107 		error = ENOENT;
1108 	sx_xunlock(&kld_sx);
1109 
1110 	CURVNET_RESTORE();
1111 	return (error);
1112 }
1113 
1114 int
1115 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1116 {
1117 
1118 	return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1119 }
1120 
1121 int
1122 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1123 {
1124 
1125 	if (uap->flags != LINKER_UNLOAD_NORMAL &&
1126 	    uap->flags != LINKER_UNLOAD_FORCE)
1127 		return (EINVAL);
1128 	return (kern_kldunload(td, uap->fileid, uap->flags));
1129 }
1130 
1131 int
1132 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1133 {
1134 	char *pathname;
1135 	const char *filename;
1136 	linker_file_t lf;
1137 	int error;
1138 
1139 #ifdef MAC
1140 	error = mac_kld_check_stat(td->td_ucred);
1141 	if (error)
1142 		return (error);
1143 #endif
1144 
1145 	td->td_retval[0] = -1;
1146 
1147 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1148 	if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1149 		goto out;
1150 
1151 	filename = linker_basename(pathname);
1152 	sx_xlock(&kld_sx);
1153 	lf = linker_find_file_by_name(filename);
1154 	if (lf)
1155 		td->td_retval[0] = lf->id;
1156 	else
1157 		error = ENOENT;
1158 	sx_xunlock(&kld_sx);
1159 out:
1160 	free(pathname, M_TEMP);
1161 	return (error);
1162 }
1163 
1164 int
1165 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1166 {
1167 	linker_file_t lf;
1168 	int error = 0;
1169 
1170 #ifdef MAC
1171 	error = mac_kld_check_stat(td->td_ucred);
1172 	if (error)
1173 		return (error);
1174 #endif
1175 
1176 	sx_xlock(&kld_sx);
1177 	if (uap->fileid == 0)
1178 		lf = TAILQ_FIRST(&linker_files);
1179 	else {
1180 		lf = linker_find_file_by_id(uap->fileid);
1181 		if (lf == NULL) {
1182 			error = ENOENT;
1183 			goto out;
1184 		}
1185 		lf = TAILQ_NEXT(lf, link);
1186 	}
1187 
1188 	/* Skip partially loaded files. */
1189 	while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1190 		lf = TAILQ_NEXT(lf, link);
1191 
1192 	if (lf)
1193 		td->td_retval[0] = lf->id;
1194 	else
1195 		td->td_retval[0] = 0;
1196 out:
1197 	sx_xunlock(&kld_sx);
1198 	return (error);
1199 }
1200 
1201 int
1202 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1203 {
1204 	struct kld_file_stat stat;
1205 	int error, version;
1206 
1207 	/*
1208 	 * Check the version of the user's structure.
1209 	 */
1210 	if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1211 	    != 0)
1212 		return (error);
1213 	if (version != sizeof(struct kld_file_stat_1) &&
1214 	    version != sizeof(struct kld_file_stat))
1215 		return (EINVAL);
1216 
1217 	error = kern_kldstat(td, uap->fileid, &stat);
1218 	if (error != 0)
1219 		return (error);
1220 	return (copyout(&stat, uap->stat, version));
1221 }
1222 
1223 int
1224 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1225 {
1226 	linker_file_t lf;
1227 	int namelen;
1228 #ifdef MAC
1229 	int error;
1230 
1231 	error = mac_kld_check_stat(td->td_ucred);
1232 	if (error)
1233 		return (error);
1234 #endif
1235 
1236 	sx_xlock(&kld_sx);
1237 	lf = linker_find_file_by_id(fileid);
1238 	if (lf == NULL) {
1239 		sx_xunlock(&kld_sx);
1240 		return (ENOENT);
1241 	}
1242 
1243 	/* Version 1 fields: */
1244 	namelen = strlen(lf->filename) + 1;
1245 	if (namelen > MAXPATHLEN)
1246 		namelen = MAXPATHLEN;
1247 	bcopy(lf->filename, &stat->name[0], namelen);
1248 	stat->refs = lf->refs;
1249 	stat->id = lf->id;
1250 	stat->address = lf->address;
1251 	stat->size = lf->size;
1252 	/* Version 2 fields: */
1253 	namelen = strlen(lf->pathname) + 1;
1254 	if (namelen > MAXPATHLEN)
1255 		namelen = MAXPATHLEN;
1256 	bcopy(lf->pathname, &stat->pathname[0], namelen);
1257 	sx_xunlock(&kld_sx);
1258 
1259 	td->td_retval[0] = 0;
1260 	return (0);
1261 }
1262 
1263 #ifdef DDB
1264 DB_COMMAND(kldstat, db_kldstat)
1265 {
1266 	linker_file_t lf;
1267 
1268 #define	POINTER_WIDTH	((int)(sizeof(void *) * 2 + 2))
1269 	db_printf("Id Refs Address%*c Size     Name\n", POINTER_WIDTH - 7, ' ');
1270 #undef	POINTER_WIDTH
1271 	TAILQ_FOREACH(lf, &linker_files, link) {
1272 		if (db_pager_quit)
1273 			return;
1274 		db_printf("%2d %4d %p %-8zx %s\n", lf->id, lf->refs,
1275 		    lf->address, lf->size, lf->filename);
1276 	}
1277 }
1278 #endif /* DDB */
1279 
1280 int
1281 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1282 {
1283 	linker_file_t lf;
1284 	module_t mp;
1285 	int error = 0;
1286 
1287 #ifdef MAC
1288 	error = mac_kld_check_stat(td->td_ucred);
1289 	if (error)
1290 		return (error);
1291 #endif
1292 
1293 	sx_xlock(&kld_sx);
1294 	lf = linker_find_file_by_id(uap->fileid);
1295 	if (lf) {
1296 		MOD_SLOCK;
1297 		mp = TAILQ_FIRST(&lf->modules);
1298 		if (mp != NULL)
1299 			td->td_retval[0] = module_getid(mp);
1300 		else
1301 			td->td_retval[0] = 0;
1302 		MOD_SUNLOCK;
1303 	} else
1304 		error = ENOENT;
1305 	sx_xunlock(&kld_sx);
1306 	return (error);
1307 }
1308 
1309 int
1310 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1311 {
1312 	char *symstr = NULL;
1313 	c_linker_sym_t sym;
1314 	linker_symval_t symval;
1315 	linker_file_t lf;
1316 	struct kld_sym_lookup lookup;
1317 	int error = 0;
1318 
1319 #ifdef MAC
1320 	error = mac_kld_check_stat(td->td_ucred);
1321 	if (error)
1322 		return (error);
1323 #endif
1324 
1325 	if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1326 		return (error);
1327 	if (lookup.version != sizeof(lookup) ||
1328 	    uap->cmd != KLDSYM_LOOKUP)
1329 		return (EINVAL);
1330 	symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1331 	if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1332 		goto out;
1333 	sx_xlock(&kld_sx);
1334 	if (uap->fileid != 0) {
1335 		lf = linker_find_file_by_id(uap->fileid);
1336 		if (lf == NULL)
1337 			error = ENOENT;
1338 		else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1339 		    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1340 			lookup.symvalue = (uintptr_t) symval.value;
1341 			lookup.symsize = symval.size;
1342 			error = copyout(&lookup, uap->data, sizeof(lookup));
1343 		} else
1344 			error = ENOENT;
1345 	} else {
1346 		TAILQ_FOREACH(lf, &linker_files, link) {
1347 			if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1348 			    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1349 				lookup.symvalue = (uintptr_t)symval.value;
1350 				lookup.symsize = symval.size;
1351 				error = copyout(&lookup, uap->data,
1352 				    sizeof(lookup));
1353 				break;
1354 			}
1355 		}
1356 		if (lf == NULL)
1357 			error = ENOENT;
1358 	}
1359 	sx_xunlock(&kld_sx);
1360 out:
1361 	free(symstr, M_TEMP);
1362 	return (error);
1363 }
1364 
1365 /*
1366  * Preloaded module support
1367  */
1368 
1369 static modlist_t
1370 modlist_lookup(const char *name, int ver)
1371 {
1372 	modlist_t mod;
1373 
1374 	TAILQ_FOREACH(mod, &found_modules, link) {
1375 		if (strcmp(mod->name, name) == 0 &&
1376 		    (ver == 0 || mod->version == ver))
1377 			return (mod);
1378 	}
1379 	return (NULL);
1380 }
1381 
1382 static modlist_t
1383 modlist_lookup2(const char *name, const struct mod_depend *verinfo)
1384 {
1385 	modlist_t mod, bestmod;
1386 	int ver;
1387 
1388 	if (verinfo == NULL)
1389 		return (modlist_lookup(name, 0));
1390 	bestmod = NULL;
1391 	TAILQ_FOREACH(mod, &found_modules, link) {
1392 		if (strcmp(mod->name, name) != 0)
1393 			continue;
1394 		ver = mod->version;
1395 		if (ver == verinfo->md_ver_preferred)
1396 			return (mod);
1397 		if (ver >= verinfo->md_ver_minimum &&
1398 		    ver <= verinfo->md_ver_maximum &&
1399 		    (bestmod == NULL || ver > bestmod->version))
1400 			bestmod = mod;
1401 	}
1402 	return (bestmod);
1403 }
1404 
1405 static modlist_t
1406 modlist_newmodule(const char *modname, int version, linker_file_t container)
1407 {
1408 	modlist_t mod;
1409 
1410 	mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1411 	if (mod == NULL)
1412 		panic("no memory for module list");
1413 	mod->container = container;
1414 	mod->name = modname;
1415 	mod->version = version;
1416 	TAILQ_INSERT_TAIL(&found_modules, mod, link);
1417 	return (mod);
1418 }
1419 
1420 static void
1421 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1422     struct mod_metadata **stop, int preload)
1423 {
1424 	struct mod_metadata *mp, **mdp;
1425 	const char *modname;
1426 	int ver;
1427 
1428 	for (mdp = start; mdp < stop; mdp++) {
1429 		mp = *mdp;
1430 		if (mp->md_type != MDT_VERSION)
1431 			continue;
1432 		modname = mp->md_cval;
1433 		ver = ((const struct mod_version *)mp->md_data)->mv_version;
1434 		if (modlist_lookup(modname, ver) != NULL) {
1435 			printf("module %s already present!\n", modname);
1436 			/* XXX what can we do? this is a build error. :-( */
1437 			continue;
1438 		}
1439 		modlist_newmodule(modname, ver, lf);
1440 	}
1441 }
1442 
1443 static void
1444 linker_preload(void *arg)
1445 {
1446 	caddr_t modptr;
1447 	const char *modname, *nmodname;
1448 	char *modtype;
1449 	linker_file_t lf, nlf;
1450 	linker_class_t lc;
1451 	int error;
1452 	linker_file_list_t loaded_files;
1453 	linker_file_list_t depended_files;
1454 	struct mod_metadata *mp, *nmp;
1455 	struct mod_metadata **start, **stop, **mdp, **nmdp;
1456 	const struct mod_depend *verinfo;
1457 	int nver;
1458 	int resolves;
1459 	modlist_t mod;
1460 	struct sysinit **si_start, **si_stop;
1461 
1462 	TAILQ_INIT(&loaded_files);
1463 	TAILQ_INIT(&depended_files);
1464 	TAILQ_INIT(&found_modules);
1465 	error = 0;
1466 
1467 	modptr = NULL;
1468 	sx_xlock(&kld_sx);
1469 	while ((modptr = preload_search_next_name(modptr)) != NULL) {
1470 		modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1471 		modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1472 		if (modname == NULL) {
1473 			printf("Preloaded module at %p does not have a"
1474 			    " name!\n", modptr);
1475 			continue;
1476 		}
1477 		if (modtype == NULL) {
1478 			printf("Preloaded module at %p does not have a type!\n",
1479 			    modptr);
1480 			continue;
1481 		}
1482 		if (bootverbose)
1483 			printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1484 			    modptr);
1485 		lf = NULL;
1486 		TAILQ_FOREACH(lc, &classes, link) {
1487 			error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1488 			if (!error)
1489 				break;
1490 			lf = NULL;
1491 		}
1492 		if (lf)
1493 			TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1494 	}
1495 
1496 	/*
1497 	 * First get a list of stuff in the kernel.
1498 	 */
1499 	if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1500 	    &stop, NULL) == 0)
1501 		linker_addmodules(linker_kernel_file, start, stop, 1);
1502 
1503 	/*
1504 	 * This is a once-off kinky bubble sort to resolve relocation
1505 	 * dependency requirements.
1506 	 */
1507 restart:
1508 	TAILQ_FOREACH(lf, &loaded_files, loaded) {
1509 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1510 		    &stop, NULL);
1511 		/*
1512 		 * First, look to see if we would successfully link with this
1513 		 * stuff.
1514 		 */
1515 		resolves = 1;	/* unless we know otherwise */
1516 		if (!error) {
1517 			for (mdp = start; mdp < stop; mdp++) {
1518 				mp = *mdp;
1519 				if (mp->md_type != MDT_DEPEND)
1520 					continue;
1521 				modname = mp->md_cval;
1522 				verinfo = mp->md_data;
1523 				for (nmdp = start; nmdp < stop; nmdp++) {
1524 					nmp = *nmdp;
1525 					if (nmp->md_type != MDT_VERSION)
1526 						continue;
1527 					nmodname = nmp->md_cval;
1528 					if (strcmp(modname, nmodname) == 0)
1529 						break;
1530 				}
1531 				if (nmdp < stop)   /* it's a self reference */
1532 					continue;
1533 
1534 				/*
1535 				 * ok, the module isn't here yet, we
1536 				 * are not finished
1537 				 */
1538 				if (modlist_lookup2(modname, verinfo) == NULL)
1539 					resolves = 0;
1540 			}
1541 		}
1542 		/*
1543 		 * OK, if we found our modules, we can link.  So, "provide"
1544 		 * the modules inside and add it to the end of the link order
1545 		 * list.
1546 		 */
1547 		if (resolves) {
1548 			if (!error) {
1549 				for (mdp = start; mdp < stop; mdp++) {
1550 					mp = *mdp;
1551 					if (mp->md_type != MDT_VERSION)
1552 						continue;
1553 					modname = mp->md_cval;
1554 					nver = ((const struct mod_version *)
1555 					    mp->md_data)->mv_version;
1556 					if (modlist_lookup(modname,
1557 					    nver) != NULL) {
1558 						printf("module %s already"
1559 						    " present!\n", modname);
1560 						TAILQ_REMOVE(&loaded_files,
1561 						    lf, loaded);
1562 						linker_file_unload(lf,
1563 						    LINKER_UNLOAD_FORCE);
1564 						/* we changed tailq next ptr */
1565 						goto restart;
1566 					}
1567 					modlist_newmodule(modname, nver, lf);
1568 				}
1569 			}
1570 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1571 			TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1572 			/*
1573 			 * Since we provided modules, we need to restart the
1574 			 * sort so that the previous files that depend on us
1575 			 * have a chance. Also, we've busted the tailq next
1576 			 * pointer with the REMOVE.
1577 			 */
1578 			goto restart;
1579 		}
1580 	}
1581 
1582 	/*
1583 	 * At this point, we check to see what could not be resolved..
1584 	 */
1585 	while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1586 		TAILQ_REMOVE(&loaded_files, lf, loaded);
1587 		printf("KLD file %s is missing dependencies\n", lf->filename);
1588 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1589 	}
1590 
1591 	/*
1592 	 * We made it. Finish off the linking in the order we determined.
1593 	 */
1594 	TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1595 		if (linker_kernel_file) {
1596 			linker_kernel_file->refs++;
1597 			error = linker_file_add_dependency(lf,
1598 			    linker_kernel_file);
1599 			if (error)
1600 				panic("cannot add dependency");
1601 		}
1602 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1603 		    &stop, NULL);
1604 		if (!error) {
1605 			for (mdp = start; mdp < stop; mdp++) {
1606 				mp = *mdp;
1607 				if (mp->md_type != MDT_DEPEND)
1608 					continue;
1609 				modname = mp->md_cval;
1610 				verinfo = mp->md_data;
1611 				mod = modlist_lookup2(modname, verinfo);
1612 				if (mod == NULL) {
1613 					printf("KLD file %s - cannot find "
1614 					    "dependency \"%s\"\n",
1615 					    lf->filename, modname);
1616 					goto fail;
1617 				}
1618 				/* Don't count self-dependencies */
1619 				if (lf == mod->container)
1620 					continue;
1621 				mod->container->refs++;
1622 				error = linker_file_add_dependency(lf,
1623 				    mod->container);
1624 				if (error)
1625 					panic("cannot add dependency");
1626 			}
1627 		}
1628 		/*
1629 		 * Now do relocation etc using the symbol search paths
1630 		 * established by the dependencies
1631 		 */
1632 		error = LINKER_LINK_PRELOAD_FINISH(lf);
1633 		if (error) {
1634 			printf("KLD file %s - could not finalize loading\n",
1635 			    lf->filename);
1636 			goto fail;
1637 		}
1638 		linker_file_register_modules(lf);
1639 		if (!TAILQ_EMPTY(&lf->modules))
1640 			lf->flags |= LINKER_FILE_MODULES;
1641 		if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1642 		    &si_stop, NULL) == 0)
1643 			sysinit_add(si_start, si_stop);
1644 		linker_file_register_sysctls(lf);
1645 		lf->flags |= LINKER_FILE_LINKED;
1646 		continue;
1647 fail:
1648 		TAILQ_REMOVE(&depended_files, lf, loaded);
1649 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1650 	}
1651 	sx_xunlock(&kld_sx);
1652 	/* woohoo! we made it! */
1653 }
1654 
1655 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1656 
1657 /*
1658  * Handle preload files that failed to load any modules.
1659  */
1660 static void
1661 linker_preload_finish(void *arg)
1662 {
1663 	linker_file_t lf, nlf;
1664 
1665 	sx_xlock(&kld_sx);
1666 	TAILQ_FOREACH_SAFE(lf, &linker_files, link, nlf) {
1667 		/*
1668 		 * If all of the modules in this file failed to load, unload
1669 		 * the file and return an error of ENOEXEC.  (Parity with
1670 		 * linker_load_file.)
1671 		 */
1672 		if ((lf->flags & LINKER_FILE_MODULES) != 0 &&
1673 		    TAILQ_EMPTY(&lf->modules)) {
1674 			linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1675 			continue;
1676 		}
1677 
1678 		lf->flags &= ~LINKER_FILE_MODULES;
1679 		lf->userrefs++;	/* so we can (try to) kldunload it */
1680 	}
1681 	sx_xunlock(&kld_sx);
1682 }
1683 
1684 /*
1685  * Attempt to run after all DECLARE_MODULE SYSINITs.  Unfortunately they can be
1686  * scheduled at any subsystem and order, so run this as late as possible.  init
1687  * becomes runnable in SI_SUB_KTHREAD_INIT, so go slightly before that.
1688  */
1689 SYSINIT(preload_finish, SI_SUB_KTHREAD_INIT - 100, SI_ORDER_MIDDLE,
1690     linker_preload_finish, 0);
1691 
1692 /*
1693  * Search for a not-loaded module by name.
1694  *
1695  * Modules may be found in the following locations:
1696  *
1697  * - preloaded (result is just the module name) - on disk (result is full path
1698  * to module)
1699  *
1700  * If the module name is qualified in any way (contains path, etc.) the we
1701  * simply return a copy of it.
1702  *
1703  * The search path can be manipulated via sysctl.  Note that we use the ';'
1704  * character as a separator to be consistent with the bootloader.
1705  */
1706 
1707 static char linker_hintfile[] = "linker.hints";
1708 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1709 
1710 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path,
1711     sizeof(linker_path), "module load search path");
1712 
1713 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1714 
1715 static char *linker_ext_list[] = {
1716 	"",
1717 	".ko",
1718 	NULL
1719 };
1720 
1721 /*
1722  * Check if file actually exists either with or without extension listed in
1723  * the linker_ext_list. (probably should be generic for the rest of the
1724  * kernel)
1725  */
1726 static char *
1727 linker_lookup_file(const char *path, int pathlen, const char *name,
1728     int namelen, struct vattr *vap)
1729 {
1730 	struct nameidata nd;
1731 	struct thread *td = curthread;	/* XXX */
1732 	char *result, **cpp, *sep;
1733 	int error, len, extlen, reclen, flags;
1734 	enum vtype type;
1735 
1736 	extlen = 0;
1737 	for (cpp = linker_ext_list; *cpp; cpp++) {
1738 		len = strlen(*cpp);
1739 		if (len > extlen)
1740 			extlen = len;
1741 	}
1742 	extlen++;		/* trailing '\0' */
1743 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1744 
1745 	reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1746 	result = malloc(reclen, M_LINKER, M_WAITOK);
1747 	for (cpp = linker_ext_list; *cpp; cpp++) {
1748 		snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1749 		    namelen, name, *cpp);
1750 		/*
1751 		 * Attempt to open the file, and return the path if
1752 		 * we succeed and it's a regular file.
1753 		 */
1754 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1755 		flags = FREAD;
1756 		error = vn_open(&nd, &flags, 0, NULL);
1757 		if (error == 0) {
1758 			NDFREE(&nd, NDF_ONLY_PNBUF);
1759 			type = nd.ni_vp->v_type;
1760 			if (vap)
1761 				VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1762 			VOP_UNLOCK(nd.ni_vp, 0);
1763 			vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1764 			if (type == VREG)
1765 				return (result);
1766 		}
1767 	}
1768 	free(result, M_LINKER);
1769 	return (NULL);
1770 }
1771 
1772 #define	INT_ALIGN(base, ptr)	ptr =					\
1773 	(base) + roundup2((ptr) - (base), sizeof(int))
1774 
1775 /*
1776  * Lookup KLD which contains requested module in the "linker.hints" file. If
1777  * version specification is available, then try to find the best KLD.
1778  * Otherwise just find the latest one.
1779  */
1780 static char *
1781 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1782     int modnamelen, const struct mod_depend *verinfo)
1783 {
1784 	struct thread *td = curthread;	/* XXX */
1785 	struct ucred *cred = td ? td->td_ucred : NULL;
1786 	struct nameidata nd;
1787 	struct vattr vattr, mattr;
1788 	u_char *hints = NULL;
1789 	u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1790 	int error, ival, bestver, *intp, found, flags, clen, blen;
1791 	ssize_t reclen;
1792 
1793 	result = NULL;
1794 	bestver = found = 0;
1795 
1796 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1797 	reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1798 	    strlen(sep) + 1;
1799 	pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1800 	snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1801 	    linker_hintfile);
1802 
1803 	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1804 	flags = FREAD;
1805 	error = vn_open(&nd, &flags, 0, NULL);
1806 	if (error)
1807 		goto bad;
1808 	NDFREE(&nd, NDF_ONLY_PNBUF);
1809 	if (nd.ni_vp->v_type != VREG)
1810 		goto bad;
1811 	best = cp = NULL;
1812 	error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1813 	if (error)
1814 		goto bad;
1815 	/*
1816 	 * XXX: we need to limit this number to some reasonable value
1817 	 */
1818 	if (vattr.va_size > LINKER_HINTS_MAX) {
1819 		printf("hints file too large %ld\n", (long)vattr.va_size);
1820 		goto bad;
1821 	}
1822 	hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1823 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1824 	    UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1825 	if (error)
1826 		goto bad;
1827 	VOP_UNLOCK(nd.ni_vp, 0);
1828 	vn_close(nd.ni_vp, FREAD, cred, td);
1829 	nd.ni_vp = NULL;
1830 	if (reclen != 0) {
1831 		printf("can't read %zd\n", reclen);
1832 		goto bad;
1833 	}
1834 	intp = (int *)hints;
1835 	ival = *intp++;
1836 	if (ival != LINKER_HINTS_VERSION) {
1837 		printf("hints file version mismatch %d\n", ival);
1838 		goto bad;
1839 	}
1840 	bufend = hints + vattr.va_size;
1841 	recptr = (u_char *)intp;
1842 	clen = blen = 0;
1843 	while (recptr < bufend && !found) {
1844 		intp = (int *)recptr;
1845 		reclen = *intp++;
1846 		ival = *intp++;
1847 		cp = (char *)intp;
1848 		switch (ival) {
1849 		case MDT_VERSION:
1850 			clen = *cp++;
1851 			if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1852 				break;
1853 			cp += clen;
1854 			INT_ALIGN(hints, cp);
1855 			ival = *(int *)cp;
1856 			cp += sizeof(int);
1857 			clen = *cp++;
1858 			if (verinfo == NULL ||
1859 			    ival == verinfo->md_ver_preferred) {
1860 				found = 1;
1861 				break;
1862 			}
1863 			if (ival >= verinfo->md_ver_minimum &&
1864 			    ival <= verinfo->md_ver_maximum &&
1865 			    ival > bestver) {
1866 				bestver = ival;
1867 				best = cp;
1868 				blen = clen;
1869 			}
1870 			break;
1871 		default:
1872 			break;
1873 		}
1874 		recptr += reclen + sizeof(int);
1875 	}
1876 	/*
1877 	 * Finally check if KLD is in the place
1878 	 */
1879 	if (found)
1880 		result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1881 	else if (best)
1882 		result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1883 
1884 	/*
1885 	 * KLD is newer than hints file. What we should do now?
1886 	 */
1887 	if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1888 		printf("warning: KLD '%s' is newer than the linker.hints"
1889 		    " file\n", result);
1890 bad:
1891 	free(pathbuf, M_LINKER);
1892 	if (hints)
1893 		free(hints, M_TEMP);
1894 	if (nd.ni_vp != NULL) {
1895 		VOP_UNLOCK(nd.ni_vp, 0);
1896 		vn_close(nd.ni_vp, FREAD, cred, td);
1897 	}
1898 	/*
1899 	 * If nothing found or hints is absent - fallback to the old
1900 	 * way by using "kldname[.ko]" as module name.
1901 	 */
1902 	if (!found && !bestver && result == NULL)
1903 		result = linker_lookup_file(path, pathlen, modname,
1904 		    modnamelen, NULL);
1905 	return (result);
1906 }
1907 
1908 /*
1909  * Lookup KLD which contains requested module in the all directories.
1910  */
1911 static char *
1912 linker_search_module(const char *modname, int modnamelen,
1913     const struct mod_depend *verinfo)
1914 {
1915 	char *cp, *ep, *result;
1916 
1917 	/*
1918 	 * traverse the linker path
1919 	 */
1920 	for (cp = linker_path; *cp; cp = ep + 1) {
1921 		/* find the end of this component */
1922 		for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1923 		result = linker_hints_lookup(cp, ep - cp, modname,
1924 		    modnamelen, verinfo);
1925 		if (result != NULL)
1926 			return (result);
1927 		if (*ep == 0)
1928 			break;
1929 	}
1930 	return (NULL);
1931 }
1932 
1933 /*
1934  * Search for module in all directories listed in the linker_path.
1935  */
1936 static char *
1937 linker_search_kld(const char *name)
1938 {
1939 	char *cp, *ep, *result;
1940 	int len;
1941 
1942 	/* qualified at all? */
1943 	if (strchr(name, '/'))
1944 		return (strdup(name, M_LINKER));
1945 
1946 	/* traverse the linker path */
1947 	len = strlen(name);
1948 	for (ep = linker_path; *ep; ep++) {
1949 		cp = ep;
1950 		/* find the end of this component */
1951 		for (; *ep != 0 && *ep != ';'; ep++);
1952 		result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1953 		if (result != NULL)
1954 			return (result);
1955 	}
1956 	return (NULL);
1957 }
1958 
1959 static const char *
1960 linker_basename(const char *path)
1961 {
1962 	const char *filename;
1963 
1964 	filename = strrchr(path, '/');
1965 	if (filename == NULL)
1966 		return path;
1967 	if (filename[1])
1968 		filename++;
1969 	return (filename);
1970 }
1971 
1972 #ifdef HWPMC_HOOKS
1973 /*
1974  * Inform hwpmc about the set of kernel modules currently loaded.
1975  */
1976 void *
1977 linker_hwpmc_list_objects(void)
1978 {
1979 	linker_file_t lf;
1980 	struct pmckern_map_in *kobase;
1981 	int i, nmappings;
1982 
1983 	nmappings = 0;
1984 	sx_slock(&kld_sx);
1985 	TAILQ_FOREACH(lf, &linker_files, link)
1986 		nmappings++;
1987 
1988 	/* Allocate nmappings + 1 entries. */
1989 	kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
1990 	    M_LINKER, M_WAITOK | M_ZERO);
1991 	i = 0;
1992 	TAILQ_FOREACH(lf, &linker_files, link) {
1993 
1994 		/* Save the info for this linker file. */
1995 		kobase[i].pm_file = lf->filename;
1996 		kobase[i].pm_address = (uintptr_t)lf->address;
1997 		i++;
1998 	}
1999 	sx_sunlock(&kld_sx);
2000 
2001 	KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
2002 
2003 	/* The last entry of the malloced area comprises of all zeros. */
2004 	KASSERT(kobase[i].pm_file == NULL,
2005 	    ("linker_hwpmc_list_objects: last object not NULL"));
2006 
2007 	return ((void *)kobase);
2008 }
2009 #endif
2010 
2011 /*
2012  * Find a file which contains given module and load it, if "parent" is not
2013  * NULL, register a reference to it.
2014  */
2015 static int
2016 linker_load_module(const char *kldname, const char *modname,
2017     struct linker_file *parent, const struct mod_depend *verinfo,
2018     struct linker_file **lfpp)
2019 {
2020 	linker_file_t lfdep;
2021 	const char *filename;
2022 	char *pathname;
2023 	int error;
2024 
2025 	sx_assert(&kld_sx, SA_XLOCKED);
2026 	if (modname == NULL) {
2027 		/*
2028  		 * We have to load KLD
2029  		 */
2030 		KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
2031 		    " is not NULL"));
2032 		pathname = linker_search_kld(kldname);
2033 	} else {
2034 		if (modlist_lookup2(modname, verinfo) != NULL)
2035 			return (EEXIST);
2036 		if (kldname != NULL)
2037 			pathname = strdup(kldname, M_LINKER);
2038 		else if (rootvnode == NULL)
2039 			pathname = NULL;
2040 		else
2041 			/*
2042 			 * Need to find a KLD with required module
2043 			 */
2044 			pathname = linker_search_module(modname,
2045 			    strlen(modname), verinfo);
2046 	}
2047 	if (pathname == NULL)
2048 		return (ENOENT);
2049 
2050 	/*
2051 	 * Can't load more than one file with the same basename XXX:
2052 	 * Actually it should be possible to have multiple KLDs with
2053 	 * the same basename but different path because they can
2054 	 * provide different versions of the same modules.
2055 	 */
2056 	filename = linker_basename(pathname);
2057 	if (linker_find_file_by_name(filename))
2058 		error = EEXIST;
2059 	else do {
2060 		error = linker_load_file(pathname, &lfdep);
2061 		if (error)
2062 			break;
2063 		if (modname && verinfo &&
2064 		    modlist_lookup2(modname, verinfo) == NULL) {
2065 			linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2066 			error = ENOENT;
2067 			break;
2068 		}
2069 		if (parent) {
2070 			error = linker_file_add_dependency(parent, lfdep);
2071 			if (error)
2072 				break;
2073 		}
2074 		if (lfpp)
2075 			*lfpp = lfdep;
2076 	} while (0);
2077 	free(pathname, M_LINKER);
2078 	return (error);
2079 }
2080 
2081 /*
2082  * This routine is responsible for finding dependencies of userland initiated
2083  * kldload(2)'s of files.
2084  */
2085 int
2086 linker_load_dependencies(linker_file_t lf)
2087 {
2088 	linker_file_t lfdep;
2089 	struct mod_metadata **start, **stop, **mdp, **nmdp;
2090 	struct mod_metadata *mp, *nmp;
2091 	const struct mod_depend *verinfo;
2092 	modlist_t mod;
2093 	const char *modname, *nmodname;
2094 	int ver, error = 0, count;
2095 
2096 	/*
2097 	 * All files are dependent on /kernel.
2098 	 */
2099 	sx_assert(&kld_sx, SA_XLOCKED);
2100 	if (linker_kernel_file) {
2101 		linker_kernel_file->refs++;
2102 		error = linker_file_add_dependency(lf, linker_kernel_file);
2103 		if (error)
2104 			return (error);
2105 	}
2106 	if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2107 	    &count) != 0)
2108 		return (0);
2109 	for (mdp = start; mdp < stop; mdp++) {
2110 		mp = *mdp;
2111 		if (mp->md_type != MDT_VERSION)
2112 			continue;
2113 		modname = mp->md_cval;
2114 		ver = ((const struct mod_version *)mp->md_data)->mv_version;
2115 		mod = modlist_lookup(modname, ver);
2116 		if (mod != NULL) {
2117 			printf("interface %s.%d already present in the KLD"
2118 			    " '%s'!\n", modname, ver,
2119 			    mod->container->filename);
2120 			return (EEXIST);
2121 		}
2122 	}
2123 
2124 	for (mdp = start; mdp < stop; mdp++) {
2125 		mp = *mdp;
2126 		if (mp->md_type != MDT_DEPEND)
2127 			continue;
2128 		modname = mp->md_cval;
2129 		verinfo = mp->md_data;
2130 		nmodname = NULL;
2131 		for (nmdp = start; nmdp < stop; nmdp++) {
2132 			nmp = *nmdp;
2133 			if (nmp->md_type != MDT_VERSION)
2134 				continue;
2135 			nmodname = nmp->md_cval;
2136 			if (strcmp(modname, nmodname) == 0)
2137 				break;
2138 		}
2139 		if (nmdp < stop)/* early exit, it's a self reference */
2140 			continue;
2141 		mod = modlist_lookup2(modname, verinfo);
2142 		if (mod) {	/* woohoo, it's loaded already */
2143 			lfdep = mod->container;
2144 			lfdep->refs++;
2145 			error = linker_file_add_dependency(lf, lfdep);
2146 			if (error)
2147 				break;
2148 			continue;
2149 		}
2150 		error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2151 		if (error) {
2152 			printf("KLD %s: depends on %s - not available or"
2153 			    " version mismatch\n", lf->filename, modname);
2154 			break;
2155 		}
2156 	}
2157 
2158 	if (error)
2159 		return (error);
2160 	linker_addmodules(lf, start, stop, 0);
2161 	return (error);
2162 }
2163 
2164 static int
2165 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2166 {
2167 	struct sysctl_req *req;
2168 
2169 	req = opaque;
2170 	return (SYSCTL_OUT(req, name, strlen(name) + 1));
2171 }
2172 
2173 /*
2174  * Export a nul-separated, double-nul-terminated list of all function names
2175  * in the kernel.
2176  */
2177 static int
2178 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2179 {
2180 	linker_file_t lf;
2181 	int error;
2182 
2183 #ifdef MAC
2184 	error = mac_kld_check_stat(req->td->td_ucred);
2185 	if (error)
2186 		return (error);
2187 #endif
2188 	error = sysctl_wire_old_buffer(req, 0);
2189 	if (error != 0)
2190 		return (error);
2191 	sx_xlock(&kld_sx);
2192 	TAILQ_FOREACH(lf, &linker_files, link) {
2193 		error = LINKER_EACH_FUNCTION_NAME(lf,
2194 		    sysctl_kern_function_list_iterate, req);
2195 		if (error) {
2196 			sx_xunlock(&kld_sx);
2197 			return (error);
2198 		}
2199 	}
2200 	sx_xunlock(&kld_sx);
2201 	return (SYSCTL_OUT(req, "", 1));
2202 }
2203 
2204 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
2205     NULL, 0, sysctl_kern_function_list, "", "kernel function list");
2206