xref: /freebsd/sys/kern/kern_linker.c (revision 2357939bc239bd5334a169b62313806178dd8f30)
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_mac.h"
32 
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/sysproto.h>
38 #include <sys/sysent.h>
39 #include <sys/proc.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/sx.h>
43 #include <sys/mac.h>
44 #include <sys/module.h>
45 #include <sys/linker.h>
46 #include <sys/fcntl.h>
47 #include <sys/libkern.h>
48 #include <sys/namei.h>
49 #include <sys/vnode.h>
50 #include <sys/sysctl.h>
51 
52 #include "linker_if.h"
53 
54 #ifdef KLD_DEBUG
55 int kld_debug = 0;
56 #endif
57 
58 /*
59  * static char *linker_search_path(const char *name, struct mod_depend
60  * *verinfo);
61  */
62 static const char 	*linker_basename(const char *path);
63 
64 /* Metadata from the static kernel */
65 SET_DECLARE(modmetadata_set, struct mod_metadata);
66 
67 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
68 
69 linker_file_t linker_kernel_file;
70 
71 static struct mtx kld_mtx;	/* kernel linker mutex */
72 
73 static linker_class_list_t classes;
74 static linker_file_list_t linker_files;
75 static int next_file_id = 1;
76 static int linker_no_more_classes = 0;
77 
78 #define	LINKER_GET_NEXT_FILE_ID(a) do {					\
79 	linker_file_t lftmp;						\
80 									\
81 retry:									\
82 	mtx_lock(&kld_mtx);						\
83 	TAILQ_FOREACH(lftmp, &linker_files, link) {			\
84 		if (next_file_id == lftmp->id) {			\
85 			next_file_id++;					\
86 			mtx_unlock(&kld_mtx);				\
87 			goto retry;					\
88 		}							\
89 	}								\
90 	(a) = next_file_id;						\
91 	mtx_unlock(&kld_mtx);	/* Hold for safe read of id variable */	\
92 } while(0)
93 
94 
95 /* XXX wrong name; we're looking at version provision tags here, not modules */
96 typedef TAILQ_HEAD(, modlist) modlisthead_t;
97 struct modlist {
98 	TAILQ_ENTRY(modlist) link;	/* chain together all modules */
99 	linker_file_t   container;
100 	const char 	*name;
101 	int             version;
102 };
103 typedef struct modlist *modlist_t;
104 static modlisthead_t found_modules;
105 
106 static modlist_t	modlist_lookup2(const char *name,
107 			    struct mod_depend *verinfo);
108 
109 static char *
110 linker_strdup(const char *str)
111 {
112 	char *result;
113 
114 	if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
115 		strcpy(result, str);
116 	return (result);
117 }
118 
119 static void
120 linker_init(void *arg)
121 {
122 
123 	mtx_init(&kld_mtx, "kernel linker", NULL, MTX_DEF);
124 	TAILQ_INIT(&classes);
125 	TAILQ_INIT(&linker_files);
126 }
127 
128 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0)
129 
130 static void
131 linker_stop_class_add(void *arg)
132 {
133 
134 	linker_no_more_classes = 1;
135 }
136 
137 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL)
138 
139 int
140 linker_add_class(linker_class_t lc)
141 {
142 
143 	/*
144 	 * We disallow any class registration passt SI_ORDER_ANY
145 	 * of SI_SUB_KLD.
146 	 */
147 	if (linker_no_more_classes == 1)
148 		return (EPERM);
149 	kobj_class_compile((kobj_class_t) lc);
150 	TAILQ_INSERT_TAIL(&classes, lc, link);
151 	return (0);
152 }
153 
154 static void
155 linker_file_sysinit(linker_file_t lf)
156 {
157 	struct sysinit **start, **stop, **sipp, **xipp, *save;
158 
159 	KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
160 	    lf->filename));
161 
162 	if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
163 		return;
164 	/*
165 	 * Perform a bubble sort of the system initialization objects by
166 	 * their subsystem (primary key) and order (secondary key).
167 	 *
168 	 * Since some things care about execution order, this is the operation
169 	 * which ensures continued function.
170 	 */
171 	for (sipp = start; sipp < stop; sipp++) {
172 		for (xipp = sipp + 1; xipp < stop; xipp++) {
173 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
174 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
175 			    (*sipp)->order <= (*xipp)->order))
176 				continue;	/* skip */
177 			save = *sipp;
178 			*sipp = *xipp;
179 			*xipp = save;
180 		}
181 	}
182 
183 	/*
184 	 * Traverse the (now) ordered list of system initialization tasks.
185 	 * Perform each task, and continue on to the next task.
186 	 */
187 	for (sipp = start; sipp < stop; sipp++) {
188 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
189 			continue;	/* skip dummy task(s) */
190 
191 		/* Call function */
192 		(*((*sipp)->func)) ((*sipp)->udata);
193 	}
194 }
195 
196 static void
197 linker_file_sysuninit(linker_file_t lf)
198 {
199 	struct sysinit **start, **stop, **sipp, **xipp, *save;
200 
201 	KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
202 	    lf->filename));
203 
204 	if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
205 	    NULL) != 0)
206 		return;
207 
208 	/*
209 	 * Perform a reverse bubble sort of the system initialization objects
210 	 * by their subsystem (primary key) and order (secondary key).
211 	 *
212 	 * Since some things care about execution order, this is the operation
213 	 * which ensures continued function.
214 	 */
215 	for (sipp = start; sipp < stop; sipp++) {
216 		for (xipp = sipp + 1; xipp < stop; xipp++) {
217 			if ((*sipp)->subsystem > (*xipp)->subsystem ||
218 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
219 			    (*sipp)->order >= (*xipp)->order))
220 				continue;	/* skip */
221 			save = *sipp;
222 			*sipp = *xipp;
223 			*xipp = save;
224 		}
225 	}
226 
227 	/*
228 	 * Traverse the (now) ordered list of system initialization tasks.
229 	 * Perform each task, and continue on to the next task.
230 	 */
231 	for (sipp = start; sipp < stop; sipp++) {
232 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
233 			continue;	/* skip dummy task(s) */
234 
235 		/* Call function */
236 		(*((*sipp)->func)) ((*sipp)->udata);
237 	}
238 }
239 
240 static void
241 linker_file_register_sysctls(linker_file_t lf)
242 {
243 	struct sysctl_oid **start, **stop, **oidp;
244 
245 	KLD_DPF(FILE,
246 	    ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
247 	    lf->filename));
248 
249 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
250 		return;
251 
252 	for (oidp = start; oidp < stop; oidp++)
253 		sysctl_register_oid(*oidp);
254 }
255 
256 static void
257 linker_file_unregister_sysctls(linker_file_t lf)
258 {
259 	struct sysctl_oid **start, **stop, **oidp;
260 
261 	KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
262 	    " for %s\n", lf->filename));
263 
264 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
265 		return;
266 
267 	for (oidp = start; oidp < stop; oidp++)
268 		sysctl_unregister_oid(*oidp);
269 }
270 
271 static int
272 linker_file_register_modules(linker_file_t lf)
273 {
274 	struct mod_metadata **start, **stop, **mdp;
275 	const moduledata_t *moddata;
276 	int error;
277 
278 	KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
279 	    " in %s\n", lf->filename));
280 
281 	if (linker_file_lookup_set(lf, "modmetadata_set", &start,
282 	    &stop, 0) != 0) {
283 		/*
284 		 * This fallback should be unnecessary, but if we get booted
285 		 * from boot2 instead of loader and we are missing our
286 		 * metadata then we have to try the best we can.
287 		 */
288 		if (lf == linker_kernel_file) {
289 			start = SET_BEGIN(modmetadata_set);
290 			stop = SET_LIMIT(modmetadata_set);
291 		} else
292 			return (0);
293 	}
294 	for (mdp = start; mdp < stop; mdp++) {
295 		if ((*mdp)->md_type != MDT_MODULE)
296 			continue;
297 		moddata = (*mdp)->md_data;
298 		KLD_DPF(FILE, ("Registering module %s in %s\n",
299 		    moddata->name, lf->filename));
300 		error = module_register(moddata, lf);
301 		if (error)
302 			printf("Module %s failed to register: %d\n",
303 			    moddata->name, error);
304 	}
305 	return (0);
306 }
307 
308 static void
309 linker_init_kernel_modules(void)
310 {
311 
312 	linker_file_register_modules(linker_kernel_file);
313 }
314 
315 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0)
316 
317 static int
318 linker_load_file(const char *filename, linker_file_t *result)
319 {
320 	linker_class_t lc;
321 	linker_file_t lf;
322 	int foundfile, error = 0;
323 
324 	/* Refuse to load modules if securelevel raised */
325 	if (securelevel > 0)
326 		return (EPERM);
327 
328 	lf = linker_find_file_by_name(filename);
329 	if (lf) {
330 		KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
331 		    " incrementing refs\n", filename));
332 		*result = lf;
333 		lf->refs++;
334 		goto out;
335 	}
336 	lf = NULL;
337 	foundfile = 0;
338 
339 	/*
340 	 * We do not need to protect (lock) classes here because there is
341 	 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
342 	 * and there is no class deregistration mechanism at this time.
343 	 */
344 	TAILQ_FOREACH(lc, &classes, link) {
345 		KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
346 		    filename));
347 		error = LINKER_LOAD_FILE(lc, filename, &lf);
348 		/*
349 		 * If we got something other than ENOENT, then it exists but
350 		 * we cannot load it for some other reason.
351 		 */
352 		if (error != ENOENT)
353 			foundfile = 1;
354 		if (lf) {
355 			linker_file_register_modules(lf);
356 			linker_file_register_sysctls(lf);
357 			linker_file_sysinit(lf);
358 			lf->flags |= LINKER_FILE_LINKED;
359 			*result = lf;
360 			error = 0;
361 			goto out;
362 		}
363 	}
364 	/*
365 	 * Less than ideal, but tells the user whether it failed to load or
366 	 * the module was not found.
367 	 */
368 	if (foundfile) {
369 		/*
370 		 * Format not recognized or otherwise unloadable.
371 		 * When loading a module that is statically built into
372 		 * the kernel EEXIST percolates back up as the return
373 		 * value.  Preserve this so that apps like sysinstall
374 		 * can recognize this special case and not post bogus
375 		 * dialog boxes.
376 		 */
377 		if (error != EEXIST)
378 			error = ENOEXEC;
379 	} else
380 		error = ENOENT;		/* Nothing found */
381 out:
382 	return (error);
383 }
384 
385 int
386 linker_reference_module(const char *modname, struct mod_depend *verinfo,
387     linker_file_t *result)
388 {
389 	modlist_t mod;
390 
391 	if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
392 		*result = mod->container;
393 		(*result)->refs++;
394 		return (0);
395 	}
396 
397 	return (linker_load_module(NULL, modname, NULL, verinfo, result));
398 }
399 
400 linker_file_t
401 linker_find_file_by_name(const char *filename)
402 {
403 	linker_file_t lf = 0;
404 	char *koname;
405 
406 	koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
407 	if (koname == NULL)
408 		goto out;
409 	sprintf(koname, "%s.ko", filename);
410 
411 	mtx_lock(&kld_mtx);
412 	TAILQ_FOREACH(lf, &linker_files, link) {
413 		if (strcmp(lf->filename, koname) == 0)
414 			break;
415 		if (strcmp(lf->filename, filename) == 0)
416 			break;
417 	}
418 	mtx_unlock(&kld_mtx);
419 out:
420 	if (koname)
421 		free(koname, M_LINKER);
422 	return (lf);
423 }
424 
425 linker_file_t
426 linker_find_file_by_id(int fileid)
427 {
428 	linker_file_t lf = 0;
429 
430 	mtx_lock(&kld_mtx);
431 	TAILQ_FOREACH(lf, &linker_files, link)
432 		if (lf->id == fileid)
433 			break;
434 	mtx_unlock(&kld_mtx);
435 	return (lf);
436 }
437 
438 linker_file_t
439 linker_make_file(const char *pathname, linker_class_t lc)
440 {
441 	linker_file_t lf;
442 	const char *filename;
443 
444 	lf = NULL;
445 	filename = linker_basename(pathname);
446 
447 	KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
448 	lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
449 	if (lf == NULL)
450 		goto out;
451 	lf->refs = 1;
452 	lf->userrefs = 0;
453 	lf->flags = 0;
454 	lf->filename = linker_strdup(filename);
455 	LINKER_GET_NEXT_FILE_ID(lf->id);
456 	lf->ndeps = 0;
457 	lf->deps = NULL;
458 	STAILQ_INIT(&lf->common);
459 	TAILQ_INIT(&lf->modules);
460 	mtx_lock(&kld_mtx);
461 	TAILQ_INSERT_TAIL(&linker_files, lf, link);
462 	mtx_unlock(&kld_mtx);
463 out:
464 	return (lf);
465 }
466 
467 int
468 linker_file_unload(linker_file_t file)
469 {
470 	module_t mod, next;
471 	modlist_t ml, nextml;
472 	struct common_symbol *cp;
473 	int error, i;
474 
475 	error = 0;
476 
477 	/* Refuse to unload modules if securelevel raised. */
478 	if (securelevel > 0)
479 		return (EPERM);
480 #ifdef MAC
481 	error = mac_check_kld_unload(curthread->td_ucred);
482 	if (error)
483 		return (error);
484 #endif
485 
486 	KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
487 	if (file->refs == 1) {
488 		KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
489 		    " informing modules\n"));
490 
491 		/*
492 		 * Inform any modules associated with this file.
493 		 */
494 		MOD_XLOCK;
495 		for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
496 			next = module_getfnext(mod);
497 			MOD_XUNLOCK;
498 
499 			/*
500 			 * Give the module a chance to veto the unload.
501 			 */
502 			if ((error = module_unload(mod)) != 0) {
503 				KLD_DPF(FILE, ("linker_file_unload: module %p"
504 				    " vetoes unload\n", mod));
505 				goto out;
506 			} else
507 				MOD_XLOCK;
508 			module_release(mod);
509 		}
510 		MOD_XUNLOCK;
511 	}
512 	file->refs--;
513 	if (file->refs > 0) {
514 		goto out;
515 	}
516 	for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) {
517 		nextml = TAILQ_NEXT(ml, link);
518 		if (ml->container == file) {
519 			TAILQ_REMOVE(&found_modules, ml, link);
520 			free(ml, M_LINKER);
521 		}
522 	}
523 
524 	/*
525 	 * Don't try to run SYSUNINITs if we are unloaded due to a
526 	 * link error.
527 	 */
528 	if (file->flags & LINKER_FILE_LINKED) {
529 		linker_file_sysuninit(file);
530 		linker_file_unregister_sysctls(file);
531 	}
532 	mtx_lock(&kld_mtx);
533 	TAILQ_REMOVE(&linker_files, file, link);
534 	mtx_unlock(&kld_mtx);
535 
536 	if (file->deps) {
537 		for (i = 0; i < file->ndeps; i++)
538 			linker_file_unload(file->deps[i]);
539 		free(file->deps, M_LINKER);
540 		file->deps = NULL;
541 	}
542 	for (cp = STAILQ_FIRST(&file->common); cp;
543 	    cp = STAILQ_FIRST(&file->common)) {
544 		STAILQ_REMOVE(&file->common, cp, common_symbol, link);
545 		free(cp, M_LINKER);
546 	}
547 
548 	LINKER_UNLOAD(file);
549 	if (file->filename) {
550 		free(file->filename, M_LINKER);
551 		file->filename = NULL;
552 	}
553 	kobj_delete((kobj_t) file, M_LINKER);
554 out:
555 	return (error);
556 }
557 
558 int
559 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
560 {
561 	linker_file_t *newdeps;
562 
563 	newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
564 	    M_LINKER, M_WAITOK | M_ZERO);
565 	if (newdeps == NULL)
566 		return (ENOMEM);
567 
568 	if (file->deps) {
569 		bcopy(file->deps, newdeps,
570 		    file->ndeps * sizeof(linker_file_t *));
571 		free(file->deps, M_LINKER);
572 	}
573 	file->deps = newdeps;
574 	file->deps[file->ndeps] = dep;
575 	file->ndeps++;
576 	return (0);
577 }
578 
579 /*
580  * Locate a linker set and its contents.  This is a helper function to avoid
581  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void ***
582  */
583 int
584 linker_file_lookup_set(linker_file_t file, const char *name,
585     void *firstp, void *lastp, int *countp)
586 {
587 
588 	return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
589 }
590 
591 caddr_t
592 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
593 {
594 	c_linker_sym_t sym;
595 	linker_symval_t symval;
596 	caddr_t address;
597 	size_t common_size = 0;
598 	int i;
599 
600 	KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
601 	    file, name, deps));
602 
603 	if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
604 		LINKER_SYMBOL_VALUES(file, sym, &symval);
605 		if (symval.value == 0)
606 			/*
607 			 * For commons, first look them up in the
608 			 * dependencies and only allocate space if not found
609 			 * there.
610 			 */
611 			common_size = symval.size;
612 		else {
613 			KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
614 			    ".value=%p\n", symval.value));
615 			return (symval.value);
616 		}
617 	}
618 	if (deps) {
619 		for (i = 0; i < file->ndeps; i++) {
620 			address = linker_file_lookup_symbol(file->deps[i],
621 			    name, 0);
622 			if (address) {
623 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
624 				    " deps value=%p\n", address));
625 				return (address);
626 			}
627 		}
628 	}
629 	if (common_size > 0) {
630 		/*
631 		 * This is a common symbol which was not found in the
632 		 * dependencies.  We maintain a simple common symbol table in
633 		 * the file object.
634 		 */
635 		struct common_symbol *cp;
636 
637 		STAILQ_FOREACH(cp, &file->common, link) {
638 			if (strcmp(cp->name, name) == 0) {
639 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
640 				    " old common value=%p\n", cp->address));
641 				return (cp->address);
642 			}
643 		}
644 		/*
645 		 * Round the symbol size up to align.
646 		 */
647 		common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
648 		cp = malloc(sizeof(struct common_symbol)
649 		    + common_size + strlen(name) + 1, M_LINKER,
650 		    M_WAITOK | M_ZERO);
651 		if (cp == NULL) {
652 			KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
653 			return (0);
654 		}
655 		cp->address = (caddr_t)(cp + 1);
656 		cp->name = cp->address + common_size;
657 		strcpy(cp->name, name);
658 		bzero(cp->address, common_size);
659 		STAILQ_INSERT_TAIL(&file->common, cp, link);
660 
661 		KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
662 		    " value=%p\n", cp->address));
663 		return (cp->address);
664 	}
665 	KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
666 	return (0);
667 }
668 
669 #ifdef DDB
670 /*
671  * DDB Helpers.  DDB has to look across multiple files with their own symbol
672  * tables and string tables.
673  *
674  * Note that we do not obey list locking protocols here.  We really don't need
675  * DDB to hang because somebody's got the lock held.  We'll take the chance
676  * that the files list is inconsistant instead.
677  */
678 
679 int
680 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
681 {
682 	linker_file_t lf;
683 
684 	TAILQ_FOREACH(lf, &linker_files, link) {
685 		if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
686 			return (0);
687 	}
688 	return (ENOENT);
689 }
690 
691 int
692 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
693 {
694 	linker_file_t lf;
695 	c_linker_sym_t best, es;
696 	u_long diff, bestdiff, off;
697 
698 	best = 0;
699 	off = (uintptr_t)value;
700 	bestdiff = off;
701 	TAILQ_FOREACH(lf, &linker_files, link) {
702 		if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
703 			continue;
704 		if (es != 0 && diff < bestdiff) {
705 			best = es;
706 			bestdiff = diff;
707 		}
708 		if (bestdiff == 0)
709 			break;
710 	}
711 	if (best) {
712 		*sym = best;
713 		*diffp = bestdiff;
714 		return (0);
715 	} else {
716 		*sym = 0;
717 		*diffp = off;
718 		return (ENOENT);
719 	}
720 }
721 
722 int
723 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
724 {
725 	linker_file_t lf;
726 
727 	TAILQ_FOREACH(lf, &linker_files, link) {
728 		if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
729 			return (0);
730 	}
731 	return (ENOENT);
732 }
733 #endif
734 
735 /*
736  * Syscalls.
737  */
738 /*
739  * MPSAFE
740  */
741 int
742 kldload(struct thread *td, struct kldload_args *uap)
743 {
744 	char *kldname, *modname;
745 	char *pathname = NULL;
746 	linker_file_t lf;
747 	int error = 0;
748 
749 	td->td_retval[0] = -1;
750 
751 	mtx_lock(&Giant);
752 
753 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
754 		goto out;
755 
756 	if ((error = suser(td)) != 0)
757 		goto out;
758 
759 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
760 	if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
761 		goto out;
762 
763 	/*
764 	 * If path do not contain qualified name or any dot in it
765 	 * (kldname.ko, or kldname.ver.ko) treat it as interface
766 	 * name.
767 	 */
768 	if (index(pathname, '/') || index(pathname, '.')) {
769 		kldname = pathname;
770 		modname = NULL;
771 	} else {
772 		kldname = NULL;
773 		modname = pathname;
774 	}
775 	error = linker_load_module(kldname, modname, NULL, NULL, &lf);
776 	if (error)
777 		goto out;
778 
779 	lf->userrefs++;
780 	td->td_retval[0] = lf->id;
781 out:
782 	if (pathname)
783 		free(pathname, M_TEMP);
784 	mtx_unlock(&Giant);
785 	return (error);
786 }
787 
788 /*
789  * MPSAFE
790  */
791 int
792 kldunload(struct thread *td, struct kldunload_args *uap)
793 {
794 	linker_file_t lf;
795 	int error = 0;
796 
797 	mtx_lock(&Giant);
798 
799 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
800 		goto out;
801 
802 	if ((error = suser(td)) != 0)
803 		goto out;
804 
805 	lf = linker_find_file_by_id(uap->fileid);
806 	if (lf) {
807 		KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
808 		if (lf->userrefs == 0) {
809 			printf("kldunload: attempt to unload file that was"
810 			    " loaded by the kernel\n");
811 			error = EBUSY;
812 			goto out;
813 		}
814 		lf->userrefs--;
815 		error = linker_file_unload(lf);
816 		if (error)
817 			lf->userrefs++;
818 	} else
819 		error = ENOENT;
820 out:
821 	mtx_unlock(&Giant);
822 	return (error);
823 }
824 
825 /*
826  * MPSAFE
827  */
828 int
829 kldfind(struct thread *td, struct kldfind_args *uap)
830 {
831 	char *pathname;
832 	const char *filename;
833 	linker_file_t lf;
834 	int error = 0;
835 
836 #ifdef MAC
837 	error = mac_check_kld_stat(td->td_ucred);
838 	if (error)
839 		return (error);
840 #endif
841 
842 	mtx_lock(&Giant);
843 	td->td_retval[0] = -1;
844 
845 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
846 	if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
847 		goto out;
848 
849 	filename = linker_basename(pathname);
850 	lf = linker_find_file_by_name(filename);
851 	if (lf)
852 		td->td_retval[0] = lf->id;
853 	else
854 		error = ENOENT;
855 out:
856 	if (pathname)
857 		free(pathname, M_TEMP);
858 	mtx_unlock(&Giant);
859 	return (error);
860 }
861 
862 /*
863  * MPSAFE
864  */
865 int
866 kldnext(struct thread *td, struct kldnext_args *uap)
867 {
868 	linker_file_t lf;
869 	int error = 0;
870 
871 #ifdef MAC
872 	error = mac_check_kld_stat(td->td_ucred);
873 	if (error)
874 		return (error);
875 #endif
876 
877 	mtx_lock(&Giant);
878 
879 	if (uap->fileid == 0) {
880 		mtx_lock(&kld_mtx);
881 		if (TAILQ_FIRST(&linker_files))
882 			td->td_retval[0] = TAILQ_FIRST(&linker_files)->id;
883 		else
884 			td->td_retval[0] = 0;
885 		mtx_unlock(&kld_mtx);
886 		goto out;
887 	}
888 	lf = linker_find_file_by_id(uap->fileid);
889 	if (lf) {
890 		if (TAILQ_NEXT(lf, link))
891 			td->td_retval[0] = TAILQ_NEXT(lf, link)->id;
892 		else
893 			td->td_retval[0] = 0;
894 	} else
895 		error = ENOENT;
896 out:
897 	mtx_unlock(&Giant);
898 	return (error);
899 }
900 
901 /*
902  * MPSAFE
903  */
904 int
905 kldstat(struct thread *td, struct kldstat_args *uap)
906 {
907 	linker_file_t lf;
908 	int error = 0;
909 	int namelen, version;
910 	struct kld_file_stat *stat;
911 
912 #ifdef MAC
913 	error = mac_check_kld_stat(td->td_ucred);
914 	if (error)
915 		return (error);
916 #endif
917 
918 	mtx_lock(&Giant);
919 
920 	lf = linker_find_file_by_id(uap->fileid);
921 	if (lf == NULL) {
922 		error = ENOENT;
923 		goto out;
924 	}
925 	stat = uap->stat;
926 
927 	/*
928 	 * Check the version of the user's structure.
929 	 */
930 	if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
931 		goto out;
932 	if (version != sizeof(struct kld_file_stat)) {
933 		error = EINVAL;
934 		goto out;
935 	}
936 	namelen = strlen(lf->filename) + 1;
937 	if (namelen > MAXPATHLEN)
938 		namelen = MAXPATHLEN;
939 	if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
940 		goto out;
941 	if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
942 		goto out;
943 	if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
944 		goto out;
945 	if ((error = copyout(&lf->address, &stat->address,
946 	    sizeof(caddr_t))) != 0)
947 		goto out;
948 	if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
949 		goto out;
950 
951 	td->td_retval[0] = 0;
952 out:
953 	mtx_unlock(&Giant);
954 	return (error);
955 }
956 
957 /*
958  * MPSAFE
959  */
960 int
961 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
962 {
963 	linker_file_t lf;
964 	module_t mp;
965 	int error = 0;
966 
967 #ifdef MAC
968 	error = mac_check_kld_stat(td->td_ucred);
969 	if (error)
970 		return (error);
971 #endif
972 
973 	mtx_lock(&Giant);
974 	lf = linker_find_file_by_id(uap->fileid);
975 	if (lf) {
976 		MOD_SLOCK;
977 		mp = TAILQ_FIRST(&lf->modules);
978 		if (mp != NULL)
979 			td->td_retval[0] = module_getid(mp);
980 		else
981 			td->td_retval[0] = 0;
982 		MOD_SUNLOCK;
983 	} else
984 		error = ENOENT;
985 	mtx_unlock(&Giant);
986 	return (error);
987 }
988 
989 /*
990  * MPSAFE
991  */
992 int
993 kldsym(struct thread *td, struct kldsym_args *uap)
994 {
995 	char *symstr = NULL;
996 	c_linker_sym_t sym;
997 	linker_symval_t symval;
998 	linker_file_t lf;
999 	struct kld_sym_lookup lookup;
1000 	int error = 0;
1001 
1002 #ifdef MAC
1003 	error = mac_check_kld_stat(td->td_ucred);
1004 	if (error)
1005 		return (error);
1006 #endif
1007 
1008 	mtx_lock(&Giant);
1009 
1010 	if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1011 		goto out;
1012 	if (lookup.version != sizeof(lookup) ||
1013 	    uap->cmd != KLDSYM_LOOKUP) {
1014 		error = EINVAL;
1015 		goto out;
1016 	}
1017 	symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1018 	if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1019 		goto out;
1020 	if (uap->fileid != 0) {
1021 		lf = linker_find_file_by_id(uap->fileid);
1022 		if (lf == NULL) {
1023 			error = ENOENT;
1024 			goto out;
1025 		}
1026 		if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1027 		    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1028 			lookup.symvalue = (uintptr_t) symval.value;
1029 			lookup.symsize = symval.size;
1030 			error = copyout(&lookup, uap->data, sizeof(lookup));
1031 		} else
1032 			error = ENOENT;
1033 	} else {
1034 		mtx_lock(&kld_mtx);
1035 		TAILQ_FOREACH(lf, &linker_files, link) {
1036 			if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1037 			    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1038 				lookup.symvalue = (uintptr_t)symval.value;
1039 				lookup.symsize = symval.size;
1040 				error = copyout(&lookup, uap->data,
1041 				    sizeof(lookup));
1042 				break;
1043 			}
1044 		}
1045 		mtx_unlock(&kld_mtx);
1046 		if (lf == NULL)
1047 			error = ENOENT;
1048 	}
1049 out:
1050 	if (symstr)
1051 		free(symstr, M_TEMP);
1052 	mtx_unlock(&Giant);
1053 	return (error);
1054 }
1055 
1056 /*
1057  * Preloaded module support
1058  */
1059 
1060 static modlist_t
1061 modlist_lookup(const char *name, int ver)
1062 {
1063 	modlist_t mod;
1064 
1065 	TAILQ_FOREACH(mod, &found_modules, link) {
1066 		if (strcmp(mod->name, name) == 0 &&
1067 		    (ver == 0 || mod->version == ver))
1068 			return (mod);
1069 	}
1070 	return (NULL);
1071 }
1072 
1073 static modlist_t
1074 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1075 {
1076 	modlist_t mod, bestmod;
1077 	int ver;
1078 
1079 	if (verinfo == NULL)
1080 		return (modlist_lookup(name, 0));
1081 	bestmod = NULL;
1082 	for (mod = TAILQ_FIRST(&found_modules); mod;
1083 	    mod = TAILQ_NEXT(mod, link)) {
1084 		if (strcmp(mod->name, name) != 0)
1085 			continue;
1086 		ver = mod->version;
1087 		if (ver == verinfo->md_ver_preferred)
1088 			return (mod);
1089 		if (ver >= verinfo->md_ver_minimum &&
1090 		    ver <= verinfo->md_ver_maximum &&
1091 		    (bestmod == NULL || ver > bestmod->version))
1092 			bestmod = mod;
1093 	}
1094 	return (bestmod);
1095 }
1096 
1097 static modlist_t
1098 modlist_newmodule(const char *modname, int version, linker_file_t container)
1099 {
1100 	modlist_t mod;
1101 
1102 	mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1103 	if (mod == NULL)
1104 		panic("no memory for module list");
1105 	mod->container = container;
1106 	mod->name = modname;
1107 	mod->version = version;
1108 	TAILQ_INSERT_TAIL(&found_modules, mod, link);
1109 	return (mod);
1110 }
1111 
1112 static void
1113 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1114     struct mod_metadata **stop, int preload)
1115 {
1116 	struct mod_metadata *mp, **mdp;
1117 	const char *modname;
1118 	int ver;
1119 
1120 	for (mdp = start; mdp < stop; mdp++) {
1121 		mp = *mdp;
1122 		if (mp->md_type != MDT_VERSION)
1123 			continue;
1124 		modname = mp->md_cval;
1125 		ver = ((struct mod_version *)mp->md_data)->mv_version;
1126 		if (modlist_lookup(modname, ver) != NULL) {
1127 			printf("module %s already present!\n", modname);
1128 			/* XXX what can we do? this is a build error. :-( */
1129 			continue;
1130 		}
1131 		modlist_newmodule(modname, ver, lf);
1132 	}
1133 }
1134 
1135 static void
1136 linker_preload(void *arg)
1137 {
1138 	caddr_t modptr;
1139 	const char *modname, *nmodname;
1140 	char *modtype;
1141 	linker_file_t lf;
1142 	linker_class_t lc;
1143 	int error;
1144 	linker_file_list_t loaded_files;
1145 	linker_file_list_t depended_files;
1146 	struct mod_metadata *mp, *nmp;
1147 	struct mod_metadata **start, **stop, **mdp, **nmdp;
1148 	struct mod_depend *verinfo;
1149 	int nver;
1150 	int resolves;
1151 	modlist_t mod;
1152 	struct sysinit **si_start, **si_stop;
1153 
1154 	TAILQ_INIT(&loaded_files);
1155 	TAILQ_INIT(&depended_files);
1156 	TAILQ_INIT(&found_modules);
1157 	error = 0;
1158 
1159 	modptr = NULL;
1160 	while ((modptr = preload_search_next_name(modptr)) != NULL) {
1161 		modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1162 		modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1163 		if (modname == NULL) {
1164 			printf("Preloaded module at %p does not have a"
1165 			    " name!\n", modptr);
1166 			continue;
1167 		}
1168 		if (modtype == NULL) {
1169 			printf("Preloaded module at %p does not have a type!\n",
1170 			    modptr);
1171 			continue;
1172 		}
1173 		printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1174 		    modptr);
1175 		lf = NULL;
1176 		TAILQ_FOREACH(lc, &classes, link) {
1177 			error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1178 			if (error) {
1179 				lf = NULL;
1180 				break;
1181 			}
1182 		}
1183 		if (lf)
1184 			TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1185 	}
1186 
1187 	/*
1188 	 * First get a list of stuff in the kernel.
1189 	 */
1190 	if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1191 	    &stop, NULL) == 0)
1192 		linker_addmodules(linker_kernel_file, start, stop, 1);
1193 
1194 	/*
1195 	 * this is a once-off kinky bubble sort resolve relocation dependency
1196 	 * requirements
1197 	 */
1198 restart:
1199 	TAILQ_FOREACH(lf, &loaded_files, loaded) {
1200 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1201 		    &stop, NULL);
1202 		/*
1203 		 * First, look to see if we would successfully link with this
1204 		 * stuff.
1205 		 */
1206 		resolves = 1;	/* unless we know otherwise */
1207 		if (!error) {
1208 			for (mdp = start; mdp < stop; mdp++) {
1209 				mp = *mdp;
1210 				if (mp->md_type != MDT_DEPEND)
1211 					continue;
1212 				modname = mp->md_cval;
1213 				verinfo = mp->md_data;
1214 				for (nmdp = start; nmdp < stop; nmdp++) {
1215 					nmp = *nmdp;
1216 					if (nmp->md_type != MDT_VERSION)
1217 						continue;
1218 					nmodname = nmp->md_cval;
1219 					if (strcmp(modname, nmodname) == 0)
1220 						break;
1221 				}
1222 				if (nmdp < stop)   /* it's a self reference */
1223 					continue;
1224 
1225 				/*
1226 				 * ok, the module isn't here yet, we
1227 				 * are not finished
1228 				 */
1229 				if (modlist_lookup2(modname, verinfo) == NULL)
1230 					resolves = 0;
1231 			}
1232 		}
1233 		/*
1234 		 * OK, if we found our modules, we can link.  So, "provide"
1235 		 * the modules inside and add it to the end of the link order
1236 		 * list.
1237 		 */
1238 		if (resolves) {
1239 			if (!error) {
1240 				for (mdp = start; mdp < stop; mdp++) {
1241 					mp = *mdp;
1242 					if (mp->md_type != MDT_VERSION)
1243 						continue;
1244 					modname = mp->md_cval;
1245 					nver = ((struct mod_version *)
1246 					    mp->md_data)->mv_version;
1247 					if (modlist_lookup(modname,
1248 					    nver) != NULL) {
1249 						printf("module %s already"
1250 						    " present!\n", modname);
1251 						linker_file_unload(lf);
1252 						TAILQ_REMOVE(&loaded_files,
1253 						    lf, loaded);
1254 						/* we changed tailq next ptr */
1255 						goto restart;
1256 					}
1257 					modlist_newmodule(modname, nver, lf);
1258 				}
1259 			}
1260 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1261 			TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1262 			/*
1263 			 * Since we provided modules, we need to restart the
1264 			 * sort so that the previous files that depend on us
1265 			 * have a chance. Also, we've busted the tailq next
1266 			 * pointer with the REMOVE.
1267 			 */
1268 			goto restart;
1269 		}
1270 	}
1271 
1272 	/*
1273 	 * At this point, we check to see what could not be resolved..
1274 	 */
1275 	TAILQ_FOREACH(lf, &loaded_files, loaded) {
1276 		printf("KLD file %s is missing dependencies\n", lf->filename);
1277 		linker_file_unload(lf);
1278 		TAILQ_REMOVE(&loaded_files, lf, loaded);
1279 	}
1280 
1281 	/*
1282 	 * We made it. Finish off the linking in the order we determined.
1283 	 */
1284 	TAILQ_FOREACH(lf, &depended_files, loaded) {
1285 		if (linker_kernel_file) {
1286 			linker_kernel_file->refs++;
1287 			error = linker_file_add_dependency(lf,
1288 			    linker_kernel_file);
1289 			if (error)
1290 				panic("cannot add dependency");
1291 		}
1292 		lf->userrefs++;	/* so we can (try to) kldunload it */
1293 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1294 		    &stop, NULL);
1295 		if (!error) {
1296 			for (mdp = start; mdp < stop; mdp++) {
1297 				mp = *mdp;
1298 				if (mp->md_type != MDT_DEPEND)
1299 					continue;
1300 				modname = mp->md_cval;
1301 				verinfo = mp->md_data;
1302 				mod = modlist_lookup2(modname, verinfo);
1303 				mod->container->refs++;
1304 				error = linker_file_add_dependency(lf,
1305 				    mod->container);
1306 				if (error)
1307 					panic("cannot add dependency");
1308 			}
1309 		}
1310 		/*
1311 		 * Now do relocation etc using the symbol search paths
1312 		 * established by the dependencies
1313 		 */
1314 		error = LINKER_LINK_PRELOAD_FINISH(lf);
1315 		if (error) {
1316 			printf("KLD file %s - could not finalize loading\n",
1317 			    lf->filename);
1318 			linker_file_unload(lf);
1319 			continue;
1320 		}
1321 		linker_file_register_modules(lf);
1322 		if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1323 		    &si_stop, NULL) == 0)
1324 			sysinit_add(si_start, si_stop);
1325 		linker_file_register_sysctls(lf);
1326 		lf->flags |= LINKER_FILE_LINKED;
1327 	}
1328 	/* woohoo! we made it! */
1329 }
1330 
1331 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0)
1332 
1333 /*
1334  * Search for a not-loaded module by name.
1335  *
1336  * Modules may be found in the following locations:
1337  *
1338  * - preloaded (result is just the module name) - on disk (result is full path
1339  * to module)
1340  *
1341  * If the module name is qualified in any way (contains path, etc.) the we
1342  * simply return a copy of it.
1343  *
1344  * The search path can be manipulated via sysctl.  Note that we use the ';'
1345  * character as a separator to be consistent with the bootloader.
1346  */
1347 
1348 static char linker_hintfile[] = "linker.hints";
1349 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1350 
1351 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1352     sizeof(linker_path), "module load search path");
1353 
1354 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1355 
1356 static char *linker_ext_list[] = {
1357 	"",
1358 	".ko",
1359 	NULL
1360 };
1361 
1362 /*
1363  * Check if file actually exists either with or without extension listed in
1364  * the linker_ext_list. (probably should be generic for the rest of the
1365  * kernel)
1366  */
1367 static char *
1368 linker_lookup_file(const char *path, int pathlen, const char *name,
1369     int namelen, struct vattr *vap)
1370 {
1371 	struct nameidata nd;
1372 	struct thread *td = curthread;	/* XXX */
1373 	char *result, **cpp, *sep;
1374 	int error, len, extlen, reclen, flags;
1375 	enum vtype type;
1376 
1377 	extlen = 0;
1378 	for (cpp = linker_ext_list; *cpp; cpp++) {
1379 		len = strlen(*cpp);
1380 		if (len > extlen)
1381 			extlen = len;
1382 	}
1383 	extlen++;		/* trailing '\0' */
1384 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1385 
1386 	reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1387 	result = malloc(reclen, M_LINKER, M_WAITOK);
1388 	for (cpp = linker_ext_list; *cpp; cpp++) {
1389 		snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1390 		    namelen, name, *cpp);
1391 		/*
1392 		 * Attempt to open the file, and return the path if
1393 		 * we succeed and it's a regular file.
1394 		 */
1395 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
1396 		flags = FREAD;
1397 		error = vn_open(&nd, &flags, 0, -1);
1398 		if (error == 0) {
1399 			NDFREE(&nd, NDF_ONLY_PNBUF);
1400 			type = nd.ni_vp->v_type;
1401 			if (vap)
1402 				VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td);
1403 			VOP_UNLOCK(nd.ni_vp, 0, td);
1404 			vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1405 			if (type == VREG)
1406 				return (result);
1407 		}
1408 	}
1409 	free(result, M_LINKER);
1410 	return (NULL);
1411 }
1412 
1413 #define	INT_ALIGN(base, ptr)	ptr =					\
1414 	(base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1415 
1416 /*
1417  * Lookup KLD which contains requested module in the "linker.hints" file. If
1418  * version specification is available, then try to find the best KLD.
1419  * Otherwise just find the latest one.
1420  */
1421 static char *
1422 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1423     int modnamelen, struct mod_depend *verinfo)
1424 {
1425 	struct thread *td = curthread;	/* XXX */
1426 	struct ucred *cred = td ? td->td_ucred : NULL;
1427 	struct nameidata nd;
1428 	struct vattr vattr, mattr;
1429 	u_char *hints = NULL;
1430 	u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1431 	int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
1432 
1433 	result = NULL;
1434 	bestver = found = 0;
1435 
1436 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1437 	reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1438 	    strlen(sep) + 1;
1439 	pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1440 	snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1441 	    linker_hintfile);
1442 
1443 	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
1444 	flags = FREAD;
1445 	error = vn_open(&nd, &flags, 0, -1);
1446 	if (error)
1447 		goto bad;
1448 	NDFREE(&nd, NDF_ONLY_PNBUF);
1449 	if (nd.ni_vp->v_type != VREG)
1450 		goto bad;
1451 	best = cp = NULL;
1452 	error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td);
1453 	if (error)
1454 		goto bad;
1455 	/*
1456 	 * XXX: we need to limit this number to some reasonable value
1457 	 */
1458 	if (vattr.va_size > 100 * 1024) {
1459 		printf("hints file too large %ld\n", (long)vattr.va_size);
1460 		goto bad;
1461 	}
1462 	hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1463 	if (hints == NULL)
1464 		goto bad;
1465 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1466 	    UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1467 	if (error)
1468 		goto bad;
1469 	VOP_UNLOCK(nd.ni_vp, 0, td);
1470 	vn_close(nd.ni_vp, FREAD, cred, td);
1471 	nd.ni_vp = NULL;
1472 	if (reclen != 0) {
1473 		printf("can't read %d\n", reclen);
1474 		goto bad;
1475 	}
1476 	intp = (int *)hints;
1477 	ival = *intp++;
1478 	if (ival != LINKER_HINTS_VERSION) {
1479 		printf("hints file version mismatch %d\n", ival);
1480 		goto bad;
1481 	}
1482 	bufend = hints + vattr.va_size;
1483 	recptr = (u_char *)intp;
1484 	clen = blen = 0;
1485 	while (recptr < bufend && !found) {
1486 		intp = (int *)recptr;
1487 		reclen = *intp++;
1488 		ival = *intp++;
1489 		cp = (char *)intp;
1490 		switch (ival) {
1491 		case MDT_VERSION:
1492 			clen = *cp++;
1493 			if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1494 				break;
1495 			cp += clen;
1496 			INT_ALIGN(hints, cp);
1497 			ival = *(int *)cp;
1498 			cp += sizeof(int);
1499 			clen = *cp++;
1500 			if (verinfo == NULL ||
1501 			    ival == verinfo->md_ver_preferred) {
1502 				found = 1;
1503 				break;
1504 			}
1505 			if (ival >= verinfo->md_ver_minimum &&
1506 			    ival <= verinfo->md_ver_maximum &&
1507 			    ival > bestver) {
1508 				bestver = ival;
1509 				best = cp;
1510 				blen = clen;
1511 			}
1512 			break;
1513 		default:
1514 			break;
1515 		}
1516 		recptr += reclen + sizeof(int);
1517 	}
1518 	/*
1519 	 * Finally check if KLD is in the place
1520 	 */
1521 	if (found)
1522 		result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1523 	else if (best)
1524 		result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1525 
1526 	/*
1527 	 * KLD is newer than hints file. What we should do now?
1528 	 */
1529 	if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1530 		printf("warning: KLD '%s' is newer than the linker.hints"
1531 		    " file\n", result);
1532 bad:
1533 	free(pathbuf, M_LINKER);
1534 	if (hints)
1535 		free(hints, M_TEMP);
1536 	if (nd.ni_vp != NULL) {
1537 		VOP_UNLOCK(nd.ni_vp, 0, td);
1538 		vn_close(nd.ni_vp, FREAD, cred, td);
1539 	}
1540 	/*
1541 	 * If nothing found or hints is absent - fallback to the old
1542 	 * way by using "kldname[.ko]" as module name.
1543 	 */
1544 	if (!found && !bestver && result == NULL)
1545 		result = linker_lookup_file(path, pathlen, modname,
1546 		    modnamelen, NULL);
1547 	return (result);
1548 }
1549 
1550 /*
1551  * Lookup KLD which contains requested module in the all directories.
1552  */
1553 static char *
1554 linker_search_module(const char *modname, int modnamelen,
1555     struct mod_depend *verinfo)
1556 {
1557 	char *cp, *ep, *result;
1558 
1559 	/*
1560 	 * traverse the linker path
1561 	 */
1562 	for (cp = linker_path; *cp; cp = ep + 1) {
1563 		/* find the end of this component */
1564 		for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1565 		result = linker_hints_lookup(cp, ep - cp, modname,
1566 		    modnamelen, verinfo);
1567 		if (result != NULL)
1568 			return (result);
1569 		if (*ep == 0)
1570 			break;
1571 	}
1572 	return (NULL);
1573 }
1574 
1575 /*
1576  * Search for module in all directories listed in the linker_path.
1577  */
1578 static char *
1579 linker_search_kld(const char *name)
1580 {
1581 	char *cp, *ep, *result, **cpp;
1582 	int extlen, len;
1583 
1584 	/* qualified at all? */
1585 	if (index(name, '/'))
1586 		return (linker_strdup(name));
1587 
1588 	extlen = 0;
1589 	for (cpp = linker_ext_list; *cpp; cpp++) {
1590 		len = strlen(*cpp);
1591 		if (len > extlen)
1592 			extlen = len;
1593 	}
1594 	extlen++;		/* trailing '\0' */
1595 
1596 	/* traverse the linker path */
1597 	len = strlen(name);
1598 	for (ep = linker_path; *ep; ep++) {
1599 		cp = ep;
1600 		/* find the end of this component */
1601 		for (; *ep != 0 && *ep != ';'; ep++);
1602 		result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1603 		if (result != NULL)
1604 			return (result);
1605 	}
1606 	return (NULL);
1607 }
1608 
1609 static const char *
1610 linker_basename(const char *path)
1611 {
1612 	const char *filename;
1613 
1614 	filename = rindex(path, '/');
1615 	if (filename == NULL)
1616 		return path;
1617 	if (filename[1])
1618 		filename++;
1619 	return (filename);
1620 }
1621 
1622 /*
1623  * Find a file which contains given module and load it, if "parent" is not
1624  * NULL, register a reference to it.
1625  */
1626 int
1627 linker_load_module(const char *kldname, const char *modname,
1628     struct linker_file *parent, struct mod_depend *verinfo,
1629     struct linker_file **lfpp)
1630 {
1631 	linker_file_t lfdep;
1632 	const char *filename;
1633 	char *pathname;
1634 	int error;
1635 
1636 	if (modname == NULL) {
1637 		/*
1638  		 * We have to load KLD
1639  		 */
1640 		KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1641 		    " is not NULL"));
1642 		pathname = linker_search_kld(kldname);
1643 	} else {
1644 		if (modlist_lookup2(modname, verinfo) != NULL)
1645 			return (EEXIST);
1646 		if (kldname != NULL)
1647 			pathname = linker_strdup(kldname);
1648 		else if (rootvnode == NULL)
1649 			pathname = NULL;
1650 		else
1651 			/*
1652 			 * Need to find a KLD with required module
1653 			 */
1654 			pathname = linker_search_module(modname,
1655 			    strlen(modname), verinfo);
1656 	}
1657 	if (pathname == NULL)
1658 		return (ENOENT);
1659 
1660 	/*
1661 	 * Can't load more than one file with the same basename XXX:
1662 	 * Actually it should be possible to have multiple KLDs with
1663 	 * the same basename but different path because they can
1664 	 * provide different versions of the same modules.
1665 	 */
1666 	filename = linker_basename(pathname);
1667 	if (linker_find_file_by_name(filename)) {
1668 		error = EEXIST;
1669 		goto out;
1670 	}
1671 	do {
1672 		error = linker_load_file(pathname, &lfdep);
1673 		if (error)
1674 			break;
1675 		if (modname && verinfo &&
1676 		    modlist_lookup2(modname, verinfo) == NULL) {
1677 			linker_file_unload(lfdep);
1678 			error = ENOENT;
1679 			break;
1680 		}
1681 		if (parent) {
1682 			error = linker_file_add_dependency(parent, lfdep);
1683 			if (error)
1684 				break;
1685 		}
1686 		if (lfpp)
1687 			*lfpp = lfdep;
1688 	} while (0);
1689 out:
1690 	if (pathname)
1691 		free(pathname, M_LINKER);
1692 	return (error);
1693 }
1694 
1695 /*
1696  * This routine is responsible for finding dependencies of userland initiated
1697  * kldload(2)'s of files.
1698  */
1699 int
1700 linker_load_dependencies(linker_file_t lf)
1701 {
1702 	linker_file_t lfdep;
1703 	struct mod_metadata **start, **stop, **mdp, **nmdp;
1704 	struct mod_metadata *mp, *nmp;
1705 	struct mod_depend *verinfo;
1706 	modlist_t mod;
1707 	const char *modname, *nmodname;
1708 	int ver, error = 0, count;
1709 
1710 	/*
1711 	 * All files are dependant on /kernel.
1712 	 */
1713 	if (linker_kernel_file) {
1714 		linker_kernel_file->refs++;
1715 		error = linker_file_add_dependency(lf, linker_kernel_file);
1716 		if (error)
1717 			return (error);
1718 	}
1719 	if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
1720 	    &count) != 0)
1721 		return (0);
1722 	for (mdp = start; mdp < stop; mdp++) {
1723 		mp = *mdp;
1724 		if (mp->md_type != MDT_VERSION)
1725 			continue;
1726 		modname = mp->md_cval;
1727 		ver = ((struct mod_version *)mp->md_data)->mv_version;
1728 		mod = modlist_lookup(modname, ver);
1729 		if (mod != NULL) {
1730 			printf("interface %s.%d already present in the KLD"
1731 			    " '%s'!\n", modname, ver,
1732 			    mod->container->filename);
1733 			return (EEXIST);
1734 		}
1735 	}
1736 
1737 	for (mdp = start; mdp < stop; mdp++) {
1738 		mp = *mdp;
1739 		if (mp->md_type != MDT_DEPEND)
1740 			continue;
1741 		modname = mp->md_cval;
1742 		verinfo = mp->md_data;
1743 		nmodname = NULL;
1744 		for (nmdp = start; nmdp < stop; nmdp++) {
1745 			nmp = *nmdp;
1746 			if (nmp->md_type != MDT_VERSION)
1747 				continue;
1748 			nmodname = nmp->md_cval;
1749 			if (strcmp(modname, nmodname) == 0)
1750 				break;
1751 		}
1752 		if (nmdp < stop)/* early exit, it's a self reference */
1753 			continue;
1754 		mod = modlist_lookup2(modname, verinfo);
1755 		if (mod) {	/* woohoo, it's loaded already */
1756 			lfdep = mod->container;
1757 			lfdep->refs++;
1758 			error = linker_file_add_dependency(lf, lfdep);
1759 			if (error)
1760 				break;
1761 			continue;
1762 		}
1763 		error = linker_load_module(NULL, modname, lf, verinfo, NULL);
1764 		if (error) {
1765 			printf("KLD %s: depends on %s - not available\n",
1766 			    lf->filename, modname);
1767 			break;
1768 		}
1769 	}
1770 
1771 	if (error)
1772 		return (error);
1773 	linker_addmodules(lf, start, stop, 0);
1774 	return (error);
1775 }
1776 
1777 static int
1778 sysctl_kern_function_list_iterate(const char *name, void *opaque)
1779 {
1780 	struct sysctl_req *req;
1781 
1782 	req = opaque;
1783 	return (SYSCTL_OUT(req, name, strlen(name) + 1));
1784 }
1785 
1786 /*
1787  * Export a nul-separated, double-nul-terminated list of all function names
1788  * in the kernel.
1789  */
1790 static int
1791 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
1792 {
1793 	linker_file_t lf;
1794 	int error;
1795 
1796 #ifdef MAC
1797 	error = mac_check_kld_stat(req->td->td_ucred);
1798 	if (error)
1799 		return (error);
1800 #endif
1801 	error = sysctl_wire_old_buffer(req, 0);
1802 	if (error != 0)
1803 		return (error);
1804 	mtx_lock(&kld_mtx);
1805 	TAILQ_FOREACH(lf, &linker_files, link) {
1806 		error = LINKER_EACH_FUNCTION_NAME(lf,
1807 		    sysctl_kern_function_list_iterate, req);
1808 		if (error) {
1809 			mtx_unlock(&kld_mtx);
1810 			return (error);
1811 		}
1812 	}
1813 	mtx_unlock(&kld_mtx);
1814 	return (SYSCTL_OUT(req, "", 1));
1815 }
1816 
1817 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
1818     NULL, 0, sysctl_kern_function_list, "", "kernel function list");
1819