xref: /dflybsd-src/sys/kern/kern_linker.c (revision e7302aa08274de307cd2c3345fc64c56dbe56e21)
1 /*-
2  * Copyright (c) 1997 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  * $FreeBSD: src/sys/kern/kern_linker.c,v 1.41.2.3 2001/11/21 17:50:35 luigi Exp $
27  * $DragonFly: src/sys/kern/kern_linker.c,v 1.44 2008/09/01 19:39:44 dillon Exp $
28  */
29 
30 #include "opt_ddb.h"
31 
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/sysproto.h>
37 #include <sys/sysent.h>
38 #include <sys/proc.h>
39 #include <sys/priv.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/queue.h>
43 #include <sys/linker.h>
44 #include <sys/fcntl.h>
45 #include <sys/libkern.h>
46 #include <sys/nlookup.h>
47 #include <sys/vnode.h>
48 #include <sys/sysctl.h>
49 
50 #include <vm/vm_zone.h>
51 
52 #include <sys/mplock2.h>
53 
54 #ifdef _KERNEL_VIRTUAL
55 #include <dlfcn.h>
56 #endif
57 
58 #ifdef KLD_DEBUG
59 int kld_debug = 1;
60 #endif
61 
62 /* Metadata from the static kernel */
63 SET_DECLARE(modmetadata_set, struct mod_metadata);
64 MALLOC_DEFINE(M_LINKER, "kld", "kernel linker");
65 
66 linker_file_t linker_current_file;
67 linker_file_t linker_kernel_file;
68 
69 static struct lock lock;	/* lock for the file list */
70 static linker_class_list_t classes;
71 static linker_file_list_t linker_files;
72 static int next_file_id = 1;
73 
74 /* XXX wrong name; we're looking at version provision tags here, not modules */
75 typedef TAILQ_HEAD(, modlist) modlisthead_t;
76 struct modlist {
77 	TAILQ_ENTRY(modlist) link;	/* chain together all modules */
78 	linker_file_t   container;
79 	const char 	*name;
80 	int             version;
81 };
82 typedef struct modlist *modlist_t;
83 static modlisthead_t found_modules;
84 
85 
86 static int linker_load_module(const char *kldname, const char *modname,
87 			      struct linker_file *parent, struct mod_depend *verinfo,
88 			      struct linker_file **lfpp);
89 
90 static char *
91 linker_strdup(const char *str)
92 {
93     char	*result;
94 
95     result = kmalloc(strlen(str) + 1, M_LINKER, M_WAITOK);
96     strcpy(result, str);
97     return(result);
98 }
99 
100 static void
101 linker_init(void* arg)
102 {
103     lockinit(&lock, "klink", 0, 0);
104     TAILQ_INIT(&classes);
105     TAILQ_INIT(&linker_files);
106 }
107 
108 SYSINIT(linker, SI_BOOT2_KLD, SI_ORDER_FIRST, linker_init, 0);
109 
110 int
111 linker_add_class(const char* desc, void* priv,
112 		 struct linker_class_ops* ops)
113 {
114     linker_class_t lc;
115 
116     lc = kmalloc(sizeof(struct linker_class), M_LINKER, M_NOWAIT | M_ZERO);
117     if (!lc)
118 	return ENOMEM;
119 
120     lc->desc = desc;
121     lc->priv = priv;
122     lc->ops = ops;
123     TAILQ_INSERT_HEAD(&classes, lc, link);
124 
125     return 0;
126 }
127 
128 static void
129 linker_file_sysinit(linker_file_t lf)
130 {
131     struct sysinit** start, ** stop;
132     struct sysinit** sipp;
133     struct sysinit** xipp;
134     struct sysinit* save;
135 
136     KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
137 		   lf->filename));
138 
139     if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
140 	return;
141 
142     /*
143      * Perform a bubble sort of the system initialization objects by
144      * their subsystem (primary key) and order (secondary key).
145      *
146      * Since some things care about execution order, this is the
147      * operation which ensures continued function.
148      */
149     for (sipp = start; sipp < stop; sipp++) {
150 	for (xipp = sipp + 1; xipp < stop; xipp++) {
151 	    if ((*sipp)->subsystem < (*xipp)->subsystem ||
152 		 ((*sipp)->subsystem == (*xipp)->subsystem &&
153 		  (*sipp)->order <= (*xipp)->order))
154 		continue;	/* skip*/
155 	    save = *sipp;
156 	    *sipp = *xipp;
157 	    *xipp = save;
158 	}
159     }
160 
161 
162     /*
163      * Traverse the (now) ordered list of system initialization tasks.
164      * Perform each task, and continue on to the next task.
165      */
166     for (sipp = start; sipp < stop; sipp++) {
167 	if ((*sipp)->subsystem == SI_SPECIAL_DUMMY)
168 	    continue;	/* skip dummy task(s)*/
169 
170 	/* Call function */
171 	(*((*sipp)->func))((*sipp)->udata);
172     }
173 }
174 
175 static void
176 linker_file_sysuninit(linker_file_t lf)
177 {
178     struct sysinit** start, ** stop;
179     struct sysinit** sipp;
180     struct sysinit** xipp;
181     struct sysinit* save;
182 
183     KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
184 		   lf->filename));
185 
186     if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0)
187 	return;
188 
189     /*
190      * Perform a reverse bubble sort of the system initialization objects
191      * by their subsystem (primary key) and order (secondary key).
192      *
193      * Since some things care about execution order, this is the
194      * operation which ensures continued function.
195      */
196     for (sipp = start; sipp < stop; sipp++) {
197 	for (xipp = sipp + 1; xipp < stop; xipp++) {
198 	    if ((*sipp)->subsystem > (*xipp)->subsystem ||
199 		 ((*sipp)->subsystem == (*xipp)->subsystem &&
200 		  (*sipp)->order >= (*xipp)->order))
201 		continue;	/* skip*/
202 	    save = *sipp;
203 	    *sipp = *xipp;
204 	    *xipp = save;
205 	}
206     }
207 
208 
209     /*
210      * Traverse the (now) ordered list of system initialization tasks.
211      * Perform each task, and continue on to the next task.
212      */
213     for (sipp = start; sipp < stop; sipp++) {
214 	if ((*sipp)->subsystem == SI_SPECIAL_DUMMY)
215 	    continue;	/* skip dummy task(s)*/
216 
217 	/* Call function */
218 	(*((*sipp)->func))((*sipp)->udata);
219     }
220 }
221 
222 static void
223 linker_file_register_sysctls(linker_file_t lf)
224 {
225     struct sysctl_oid **start, **stop, **oidp;
226 
227     KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
228 		   lf->filename));
229 
230     if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
231 	return;
232     for (oidp = start; oidp < stop; oidp++)
233 	sysctl_register_oid(*oidp);
234 }
235 
236 static void
237 linker_file_unregister_sysctls(linker_file_t lf)
238 {
239     struct sysctl_oid **start, **stop, **oidp;
240 
241     KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n",
242 		   lf->filename));
243 
244     if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
245 	return;
246     for (oidp = start; oidp < stop; oidp++)
247 	sysctl_unregister_oid(*oidp);
248 }
249 
250 static int
251 linker_file_register_modules(linker_file_t lf)
252 {
253     struct mod_metadata **start, **stop, **mdp;
254     const moduledata_t *moddata;
255     int		    first_error, error;
256 
257     KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n",
258 		   lf->filename));
259 
260     if (linker_file_lookup_set(lf, "modmetadata_set", &start, &stop, NULL) != 0) {
261 	/*
262 	 * This fallback should be unnecessary, but if we get booted
263 	 * from boot2 instead of loader and we are missing our
264 	 * metadata then we have to try the best we can.
265 	 */
266 	if (lf == linker_kernel_file) {
267 	    start = SET_BEGIN(modmetadata_set);
268 	    stop = SET_LIMIT(modmetadata_set);
269 	} else
270 	    return (0);
271     }
272     first_error = 0;
273     for (mdp = start; mdp < stop; mdp++) {
274 	if ((*mdp)->md_type != MDT_MODULE)
275 	    continue;
276 	moddata = (*mdp)->md_data;
277 	KLD_DPF(FILE, ("Registering module %s in %s\n", moddata->name, lf->filename));
278 	error = module_register(moddata, lf);
279 	if (error) {
280 	    kprintf("Module %s failed to register: %d\n", moddata->name, error);
281 	    if (first_error == 0)
282 		first_error = error;
283 	}
284     }
285     return (first_error);
286 }
287 
288 static void
289 linker_init_kernel_modules(void)
290 {
291 
292     linker_file_register_modules(linker_kernel_file);
293 }
294 
295 SYSINIT(linker_kernel, SI_BOOT2_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0);
296 
297 int
298 linker_load_file(const char *filename, linker_file_t *result)
299 {
300     linker_class_t lc;
301     linker_file_t lf;
302     int foundfile, error = 0;
303 
304     /* Refuse to load modules if securelevel raised */
305     if (securelevel > 0 || kernel_mem_readonly)
306 	return EPERM;
307 
308     lf = linker_find_file_by_name(filename);
309     if (lf) {
310 	KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename));
311 	*result = lf;
312 	lf->refs++;
313 	goto out;
314     }
315 
316     lf = NULL;
317     foundfile = 0;
318     TAILQ_FOREACH(lc, &classes, link) {
319 	KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n",
320 		       filename, lc->desc));
321 
322 	error = lc->ops->load_file(filename, &lf);
323 	/*
324 	 * If we got something other than ENOENT, then it exists but we cannot
325 	 * load it for some other reason.
326 	 */
327 	if (error != ENOENT)
328 	    foundfile = 1;
329 	if (lf) {
330 	    error = linker_file_register_modules(lf);
331 	    if (error == EEXIST) {
332 		    linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */);
333 		    return (error);
334 	    }
335 	    linker_file_register_sysctls(lf);
336 	    linker_file_sysinit(lf);
337 	    lf->flags |= LINKER_FILE_LINKED;
338 	    *result = lf;
339 	    return (0);
340 	}
341     }
342     /*
343      * Less than ideal, but tells the user whether it failed to load or
344      * the module was not found.
345      */
346     if (foundfile) {
347 	    /*
348 	     * If the file type has not been recognized by the last try
349 	     * printout a message before to fail.
350 	     */
351 	    if (error == ENOSYS)
352 		    kprintf("linker_load_file: Unsupported file type\n");
353 
354 	    /*
355 	     * Format not recognized or otherwise unloadable.
356 	     * When loading a module that is statically built into
357 	     * the kernel EEXIST percolates back up as the return
358 	     * value.  Preserve this so that apps can recognize this
359 	     * special case.
360 	     */
361 	    if (error != EEXIST)
362 		    error = ENOEXEC;
363     } else {
364 	error = ENOENT;		/* Nothing found */
365     }
366 
367 out:
368     return error;
369 }
370 
371 linker_file_t
372 linker_find_file_by_name(const char* filename)
373 {
374     linker_file_t lf = 0;
375     char *koname;
376     int i;
377 
378     for (i = strlen(filename); i > 0 && filename[i-1] != '/'; --i)
379 	;
380     filename += i;
381 
382     koname = kmalloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
383     ksprintf(koname, "%s.ko", filename);
384 
385     lockmgr(&lock, LK_SHARED);
386     TAILQ_FOREACH(lf, &linker_files, link) {
387 	if (!strcmp(lf->filename, koname))
388 	    break;
389 	if (!strcmp(lf->filename, filename))
390 	    break;
391     }
392     lockmgr(&lock, LK_RELEASE);
393 
394     if (koname)
395 	kfree(koname, M_LINKER);
396     return lf;
397 }
398 
399 linker_file_t
400 linker_find_file_by_id(int fileid)
401 {
402     linker_file_t lf = 0;
403 
404     lockmgr(&lock, LK_SHARED);
405     TAILQ_FOREACH(lf, &linker_files, link)
406 	if (lf->id == fileid)
407 	    break;
408     lockmgr(&lock, LK_RELEASE);
409 
410     return lf;
411 }
412 
413 linker_file_t
414 linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops)
415 {
416     linker_file_t lf = 0;
417     const char *filename;
418 
419     filename = rindex(pathname, '/');
420     if (filename && filename[1])
421 	filename++;
422     else
423 	filename = pathname;
424 
425     KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
426     lockmgr(&lock, LK_EXCLUSIVE);
427     lf = kmalloc(sizeof(struct linker_file), M_LINKER, M_WAITOK);
428     bzero(lf, sizeof(*lf));
429 
430     lf->refs = 1;
431     lf->userrefs = 0;
432     lf->flags = 0;
433     lf->filename = linker_strdup(filename);
434     lf->id = next_file_id++;
435     lf->ndeps = 0;
436     lf->deps = NULL;
437     STAILQ_INIT(&lf->common);
438     TAILQ_INIT(&lf->modules);
439 
440     lf->priv = priv;
441     lf->ops = ops;
442     TAILQ_INSERT_TAIL(&linker_files, lf, link);
443 
444     lockmgr(&lock, LK_RELEASE);
445     return lf;
446 }
447 
448 int
449 linker_file_unload(linker_file_t file)
450 {
451     module_t mod, next;;
452     modlist_t ml, nextml;
453     struct common_symbol* cp;
454     int error = 0;
455     int i;
456 
457     /* Refuse to unload modules if securelevel raised */
458     if (securelevel > 0 || kernel_mem_readonly)
459 	return EPERM;
460 
461     KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
462 
463     lockmgr(&lock, LK_EXCLUSIVE);
464 
465     /* Easy case of just dropping a reference. */
466     if (file->refs > 1) {
467 	    file->refs--;
468 	    lockmgr(&lock, LK_RELEASE);
469 	    return (0);
470     }
471 
472     KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
473 
474     /*
475      * Inform any modules associated with this file.
476      */
477     mod = TAILQ_FIRST(&file->modules);
478     for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
479 	next = module_getfnext(mod);
480 
481 	/*
482 	 * Give the module a chance to veto the unload.  Note that the
483 	 * act of unloading the module may cause other modules in the
484 	 * same file list to be unloaded recursively.
485 	 */
486 	if ((error = module_unload(mod)) != 0) {
487 	    KLD_DPF(FILE, ("linker_file_unload: module %p vetoes unload\n",
488 			   mod));
489 	    lockmgr(&lock, LK_RELEASE);
490 	    file->refs--;
491 	    goto out;
492 	}
493 	module_release(mod);
494     }
495 
496     TAILQ_FOREACH_MUTABLE(ml, &found_modules, link, nextml) {
497 	if (ml->container == file) {
498 	    TAILQ_REMOVE(&found_modules, ml, link);
499 	    kfree(ml, M_LINKER);
500 	}
501     }
502 
503     /* Don't try to run SYSUNINITs if we are unloaded due to a link error */
504     if (file->flags & LINKER_FILE_LINKED) {
505 	file->flags &= ~LINKER_FILE_LINKED;
506 	lockmgr(&lock, LK_RELEASE);
507 	linker_file_sysuninit(file);
508 	linker_file_unregister_sysctls(file);
509 	lockmgr(&lock, LK_EXCLUSIVE);
510     }
511 
512     TAILQ_REMOVE(&linker_files, file, link);
513 
514     if (file->deps) {
515 	lockmgr(&lock, LK_RELEASE);
516 	for (i = 0; i < file->ndeps; i++)
517 	    linker_file_unload(file->deps[i]);
518 	lockmgr(&lock, LK_EXCLUSIVE);
519 	kfree(file->deps, M_LINKER);
520 	file->deps = NULL;
521     }
522 
523     while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
524 	STAILQ_REMOVE_HEAD(&file->common, link);
525 	kfree(cp, M_LINKER);
526     }
527 
528     file->ops->unload(file);
529 
530     if (file->filename) {
531 	kfree(file->filename, M_LINKER);
532 	file->filename = NULL;
533     }
534 
535     kfree(file, M_LINKER);
536 
537     lockmgr(&lock, LK_RELEASE);
538 
539 out:
540     return error;
541 }
542 
543 void
544 linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
545 {
546     linker_file_t* newdeps;
547 
548     newdeps = kmalloc((file->ndeps + 1) * sizeof(linker_file_t*),
549 		     M_LINKER, M_WAITOK | M_ZERO);
550 
551     if (file->deps) {
552 	bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
553 	kfree(file->deps, M_LINKER);
554     }
555     file->deps = newdeps;
556     file->deps[file->ndeps] = dep;
557     file->ndeps++;
558 }
559 
560 /*
561  * Locate a linker set and its contents.
562  * This is a helper function to avoid linker_if.h exposure elsewhere.
563  * Note: firstp and lastp are really void ***
564  */
565 int
566 linker_file_lookup_set(linker_file_t file, const char *name,
567                       void *firstp, void *lastp, int *countp)
568 {
569     return file->ops->lookup_set(file, name, firstp, lastp, countp);
570 }
571 
572 int
573 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps, caddr_t *raddr)
574 {
575     c_linker_sym_t sym;
576     linker_symval_t symval;
577     linker_file_t lf;
578     size_t common_size = 0;
579     int i;
580 
581     KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
582 		  file, name, deps));
583 
584     if (file->ops->lookup_symbol(file, name, &sym) == 0) {
585 	file->ops->symbol_values(file, sym, &symval);
586 
587 	/*
588 	 * XXX Assume a common symbol if its value is 0 and it has a non-zero
589 	 * size, otherwise it could be an absolute symbol with a value of 0.
590 	 */
591 	if (symval.value == 0 && symval.size != 0) {
592 	    /*
593 	     * For commons, first look them up in the dependancies and
594 	     * only allocate space if not found there.
595 	     */
596 	    common_size = symval.size;
597 	} else {
598 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%p\n", symval.value));
599 	    *raddr = symval.value;
600 	    return 0;
601 	}
602     }
603     if (deps) {
604 	for (i = 0; i < file->ndeps; i++) {
605 	    if (linker_file_lookup_symbol(file->deps[i], name, 0, raddr) == 0) {
606 		KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%p\n", *raddr));
607 		return 0;
608 	    }
609 	}
610 
611 	/* If we have not found it in the dependencies, search globally */
612 	TAILQ_FOREACH(lf, &linker_files, link) {
613 	    /* But skip the current file if it's on the list */
614 	    if (lf == file)
615 		continue;
616 	    /* And skip the files we searched above */
617 	    for (i = 0; i < file->ndeps; i++)
618 		if (lf == file->deps[i])
619 		    break;
620 	    if (i < file->ndeps)
621 		continue;
622 	    if (linker_file_lookup_symbol(lf, name, 0, raddr) == 0) {
623 		KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%p\n", *raddr));
624 		return 0;
625 	    }
626 	}
627     }
628 
629     if (common_size > 0) {
630 	/*
631 	 * This is a common symbol which was not found in the
632 	 * dependancies.  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)) {
639 		KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%p\n", cp->address));
640 		*raddr = cp->address;
641 		return 0;
642 	    }
643 
644 	/*
645 	 * Round the symbol size up to align.
646 	 */
647 	common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
648 	cp = kmalloc(sizeof(struct common_symbol)
649 		    + common_size
650 		    + strlen(name) + 1,
651 		    M_LINKER, M_WAITOK | M_ZERO);
652 
653 	cp->address = (caddr_t) (cp + 1);
654 	cp->name = cp->address + common_size;
655 	strcpy(cp->name, name);
656 	bzero(cp->address, common_size);
657 	STAILQ_INSERT_TAIL(&file->common, cp, link);
658 
659 	KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%p\n", cp->address));
660 	*raddr = cp->address;
661 	return 0;
662     }
663 
664 #ifdef _KERNEL_VIRTUAL
665     *raddr = dlsym(RTLD_NEXT, name);
666     if (*raddr != NULL) {
667 	KLD_DPF(SYM, ("linker_file_lookup_symbol: found dlsym=%x\n", *raddr));
668 	return 0;
669     }
670 #endif
671 
672     KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
673     return ENOENT;
674 }
675 
676 #ifdef DDB
677 /*
678  * DDB Helpers.  DDB has to look across multiple files with their own
679  * symbol tables and string tables.
680  *
681  * Note that we do not obey list locking protocols here.  We really don't
682  * need DDB to hang because somebody's got the lock held.  We'll take the
683  * chance that the files list is inconsistant instead.
684  */
685 
686 int
687 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
688 {
689     linker_file_t lf;
690 
691     TAILQ_FOREACH(lf, &linker_files, link) {
692 	if (lf->ops->lookup_symbol(lf, symstr, sym) == 0)
693 	    return 0;
694     }
695     return ENOENT;
696 }
697 
698 int
699 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
700 {
701     linker_file_t lf;
702     u_long off = (uintptr_t)value;
703     u_long diff, bestdiff;
704     c_linker_sym_t best;
705     c_linker_sym_t es;
706 
707     best = 0;
708     bestdiff = off;
709     TAILQ_FOREACH(lf, &linker_files, link) {
710 	if (lf->ops->search_symbol(lf, value, &es, &diff) != 0)
711 	    continue;
712 	if (es != 0 && diff < bestdiff) {
713 	    best = es;
714 	    bestdiff = diff;
715 	}
716 	if (bestdiff == 0)
717 	    break;
718     }
719     if (best) {
720 	*sym = best;
721 	*diffp = bestdiff;
722 	return 0;
723     } else {
724 	*sym = 0;
725 	*diffp = off;
726 	return ENOENT;
727     }
728 }
729 
730 int
731 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
732 {
733     linker_file_t lf;
734 
735     TAILQ_FOREACH(lf, &linker_files, link) {
736 	if (lf->ops->symbol_values(lf, sym, symval) == 0)
737 	    return 0;
738     }
739     return ENOENT;
740 }
741 
742 #endif
743 
744 /*
745  * Syscalls.
746  *
747  * MPALMOSTSAFE
748  */
749 int
750 sys_kldload(struct kldload_args *uap)
751 {
752     struct thread *td = curthread;
753     char *file;
754     char *kldname, *modname;
755     linker_file_t lf;
756     int error = 0;
757 
758     uap->sysmsg_result = -1;
759 
760     if (securelevel > 0 || kernel_mem_readonly)	/* redundant, but that's OK */
761 	return EPERM;
762 
763     if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
764 	return error;
765 
766     file = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
767     if ((error = copyinstr(uap->file, file, MAXPATHLEN, NULL)) != 0)
768 	goto out;
769 
770     /*
771      * If file does not contain a qualified name or any dot in it
772      * (kldname.ko, or kldname.ver.ko) treat it as an interface
773      * name.
774      */
775     if (index(file, '/') || index(file, '.')) {
776 	kldname = file;
777 	modname = NULL;
778     } else {
779 	kldname = NULL;
780 	modname = file;
781     }
782 
783     get_mplock();
784     error = linker_load_module(kldname, modname, NULL, NULL, &lf);
785     rel_mplock();
786     if (error)
787 	goto out;
788 
789     lf->userrefs++;
790     uap->sysmsg_result = lf->id;
791 
792 out:
793     if (file)
794 	kfree(file, M_TEMP);
795     return error;
796 }
797 
798 /*
799  * MPALMOSTSAFE
800  */
801 int
802 sys_kldunload(struct kldunload_args *uap)
803 {
804     struct thread *td = curthread;
805     linker_file_t lf;
806     int error = 0;
807 
808     if (securelevel > 0 || kernel_mem_readonly)	/* redundant, but that's OK */
809 	return EPERM;
810 
811     if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
812 	return error;
813 
814     get_mplock();
815     lf = linker_find_file_by_id(uap->fileid);
816     if (lf) {
817 	KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
818 	if (lf->userrefs == 0) {
819 	    kprintf("linkerunload: attempt to unload file that was loaded by the kernel\n");
820 	    error = EBUSY;
821 	    goto out;
822 	}
823 	lf->userrefs--;
824 	error = linker_file_unload(lf);
825 	if (error)
826 	    lf->userrefs++;
827     } else {
828 	error = ENOENT;
829     }
830 out:
831     rel_mplock();
832     return error;
833 }
834 
835 /*
836  * MPALMOSTSAFE
837  */
838 int
839 sys_kldfind(struct kldfind_args *uap)
840 {
841     char *filename = NULL, *modulename;
842     linker_file_t lf;
843     int error;
844 
845     uap->sysmsg_result = -1;
846 
847     filename = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
848     if ((error = copyinstr(uap->file, filename, MAXPATHLEN, NULL)) != 0)
849 	goto out;
850 
851     modulename = rindex(filename, '/');
852     if (modulename == NULL)
853 	modulename = filename;
854 
855     get_mplock();
856     lf = linker_find_file_by_name(modulename);
857     if (lf)
858 	uap->sysmsg_result = lf->id;
859     else
860 	error = ENOENT;
861     rel_mplock();
862 
863 out:
864     if (filename)
865 	kfree(filename, M_TEMP);
866     return error;
867 }
868 
869 /*
870  * MPALMOSTSAFE
871  */
872 int
873 sys_kldnext(struct kldnext_args *uap)
874 {
875     linker_file_t lf;
876     int error = 0;
877 
878     get_mplock();
879     if (uap->fileid == 0) {
880 	    lf = TAILQ_FIRST(&linker_files);
881     } else {
882 	    lf = linker_find_file_by_id(uap->fileid);
883 	    if (lf == NULL) {
884 		    error = ENOENT;
885 		    goto out;
886 	    }
887 	    lf = TAILQ_NEXT(lf, link);
888     }
889 
890     /* Skip partially loaded files. */
891     while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) {
892 	    lf = TAILQ_NEXT(lf, link);
893     }
894 
895     if (lf)
896 	uap->sysmsg_result = lf->id;
897     else
898 	uap->sysmsg_result = 0;
899 
900 out:
901     rel_mplock();
902     return error;
903 }
904 
905 /*
906  * MPALMOSTSAFE
907  */
908 int
909 sys_kldstat(struct kldstat_args *uap)
910 {
911     linker_file_t lf;
912     int error = 0;
913     int version;
914     struct kld_file_stat* stat;
915     int namelen;
916 
917     get_mplock();
918     lf = linker_find_file_by_id(uap->fileid);
919     if (!lf) {
920 	error = ENOENT;
921 	goto out;
922     }
923 
924     stat = uap->stat;
925 
926     /*
927      * Check the version of the user's structure.
928      */
929     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
930 	goto out;
931     if (version != sizeof(struct kld_file_stat)) {
932 	error = EINVAL;
933 	goto out;
934     }
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, sizeof(caddr_t))) != 0)
946 	goto out;
947     if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
948 	goto out;
949 
950     uap->sysmsg_result = 0;
951 
952 out:
953     rel_mplock();
954     return error;
955 }
956 
957 /*
958  * MPALMOSTSAFE
959  */
960 int
961 sys_kldfirstmod(struct kldfirstmod_args *uap)
962 {
963     linker_file_t lf;
964     int error = 0;
965 
966     get_mplock();
967     lf = linker_find_file_by_id(uap->fileid);
968     if (lf) {
969 	if (TAILQ_FIRST(&lf->modules))
970 	    uap->sysmsg_result = module_getid(TAILQ_FIRST(&lf->modules));
971 	else
972 	    uap->sysmsg_result = 0;
973     } else {
974 	error = ENOENT;
975     }
976     rel_mplock();
977 
978     return error;
979 }
980 
981 /*
982  * MPALMOSTSAFE
983  */
984 int
985 sys_kldsym(struct kldsym_args *uap)
986 {
987     char *symstr = NULL;
988     c_linker_sym_t sym;
989     linker_symval_t symval;
990     linker_file_t lf;
991     struct kld_sym_lookup lookup;
992     int error = 0;
993 
994     get_mplock();
995     if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
996 	goto out;
997     if (lookup.version != sizeof(lookup) || uap->cmd != KLDSYM_LOOKUP) {
998 	error = EINVAL;
999 	goto out;
1000     }
1001 
1002     symstr = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1003     if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1004 	goto out;
1005 
1006     if (uap->fileid != 0) {
1007 	lf = linker_find_file_by_id(uap->fileid);
1008 	if (lf == NULL) {
1009 	    error = ENOENT;
1010 	    goto out;
1011 	}
1012 	if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
1013 	    lf->ops->symbol_values(lf, sym, &symval) == 0) {
1014 	    lookup.symvalue = (uintptr_t)symval.value;
1015 	    lookup.symsize = symval.size;
1016 	    error = copyout(&lookup, uap->data, sizeof(lookup));
1017 	} else
1018 	    error = ENOENT;
1019     } else {
1020 	TAILQ_FOREACH(lf, &linker_files, link) {
1021 	    if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
1022 		lf->ops->symbol_values(lf, sym, &symval) == 0) {
1023 		lookup.symvalue = (uintptr_t)symval.value;
1024 		lookup.symsize = symval.size;
1025 		error = copyout(&lookup, uap->data, sizeof(lookup));
1026 		break;
1027 	    }
1028 	}
1029 	if (!lf)
1030 	    error = ENOENT;
1031     }
1032 out:
1033     rel_mplock();
1034     if (symstr)
1035 	kfree(symstr, M_TEMP);
1036     return error;
1037 }
1038 
1039 /*
1040  * Preloaded module support
1041  */
1042 
1043 static modlist_t
1044 modlist_lookup(const char *name, int ver)
1045 {
1046     modlist_t	    mod;
1047 
1048     TAILQ_FOREACH(mod, &found_modules, link) {
1049 	if (strcmp(mod->name, name) == 0 && (ver == 0 || mod->version == ver))
1050 	    return (mod);
1051     }
1052     return (NULL);
1053 }
1054 
1055 static modlist_t
1056 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1057 {
1058     modlist_t	    mod, bestmod;
1059     int		    ver;
1060 
1061     if (verinfo == NULL)
1062 	return (modlist_lookup(name, 0));
1063     bestmod = NULL;
1064     TAILQ_FOREACH(mod, &found_modules, link) {
1065 	if (strcmp(mod->name, name) != 0)
1066 	    continue;
1067 	ver = mod->version;
1068 	if (ver == verinfo->md_ver_preferred)
1069 	    return (mod);
1070 	if (ver >= verinfo->md_ver_minimum &&
1071 		ver <= verinfo->md_ver_maximum &&
1072 		(bestmod == NULL || ver > bestmod->version))
1073 	    bestmod = mod;
1074     }
1075     return (bestmod);
1076 }
1077 
1078 static modlist_t
1079 modlist_newmodule(const char *modname, int version, linker_file_t container)
1080 {
1081     modlist_t	    mod;
1082 
1083     mod = kmalloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1084     if (mod == NULL)
1085 	panic("no memory for module list");
1086     mod->container = container;
1087     mod->name = modname;
1088     mod->version = version;
1089     TAILQ_INSERT_TAIL(&found_modules, mod, link);
1090     return (mod);
1091 }
1092 
1093 static void
1094 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1095 		  struct mod_metadata **stop, int preload)
1096 {
1097     struct mod_metadata *mp, **mdp;
1098     const char     *modname;
1099     int		    ver;
1100 
1101     for (mdp = start; mdp < stop; mdp++) {
1102 	mp = *mdp;
1103 	if (mp->md_type != MDT_VERSION)
1104 	    continue;
1105 	modname = mp->md_cval;
1106 	ver = ((struct mod_version *)mp->md_data)->mv_version;
1107 	if (modlist_lookup(modname, ver) != NULL) {
1108 	    kprintf("module %s already present!\n", modname);
1109 	    /* XXX what can we do? this is a build error. :-( */
1110 	    continue;
1111 	}
1112 	modlist_newmodule(modname, ver, lf);
1113     }
1114 }
1115 
1116 static void
1117 linker_preload(void* arg)
1118 {
1119     caddr_t		modptr;
1120     const char		*modname, *nmodname;
1121     char		*modtype;
1122     linker_file_t	lf, nlf;
1123     linker_class_t	lc;
1124     int			error;
1125     linker_file_list_t loaded_files;
1126     linker_file_list_t depended_files;
1127     struct mod_metadata *mp, *nmp;
1128     struct mod_metadata **start, **stop, **mdp, **nmdp;
1129     struct mod_depend *verinfo;
1130     int nver;
1131     int resolves;
1132     modlist_t mod;
1133     struct sysinit	**si_start, **si_stop;
1134 
1135     TAILQ_INIT(&loaded_files);
1136     TAILQ_INIT(&depended_files);
1137     TAILQ_INIT(&found_modules);
1138 
1139     modptr = NULL;
1140     while ((modptr = preload_search_next_name(modptr)) != NULL) {
1141 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1142 	modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1143 	if (modname == NULL) {
1144 	    kprintf("Preloaded module at %p does not have a name!\n", modptr);
1145 	    continue;
1146 	}
1147 	if (modtype == NULL) {
1148 	    kprintf("Preloaded module at %p does not have a type!\n", modptr);
1149 	    continue;
1150 	}
1151 
1152 	if (bootverbose)
1153 		kprintf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
1154 	lf = NULL;
1155 	TAILQ_FOREACH(lc, &classes, link) {
1156 	    error = lc->ops->preload_file(modname, &lf);
1157 	    if (!error)
1158 		break;
1159 	    lf = NULL;
1160 	}
1161 	if (lf)
1162 		TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1163     }
1164 
1165     /*
1166      * First get a list of stuff in the kernel.
1167      */
1168     if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1169 			       &stop, NULL) == 0)
1170 	linker_addmodules(linker_kernel_file, start, stop, 1);
1171 
1172     /*
1173      * This is a once-off kinky bubble sort to resolve relocation
1174      * dependency requirements.
1175      */
1176 restart:
1177     TAILQ_FOREACH(lf, &loaded_files, loaded) {
1178 	error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL);
1179 	/*
1180 	 * First, look to see if we would successfully link with this
1181 	 * stuff.
1182 	 */
1183 	resolves = 1;		/* unless we know otherwise */
1184 	if (!error) {
1185 	    for (mdp = start; mdp < stop; mdp++) {
1186 		mp = *mdp;
1187 		if (mp->md_type != MDT_DEPEND)
1188 		    continue;
1189 		modname = mp->md_cval;
1190 		verinfo = mp->md_data;
1191 		for (nmdp = start; nmdp < stop; nmdp++) {
1192 		    nmp = *nmdp;
1193 		    if (nmp->md_type != MDT_VERSION)
1194 			continue;
1195 		    nmodname = nmp->md_cval;
1196 		    if (strcmp(modname, nmodname) == 0)
1197 			break;
1198 		}
1199 		if (nmdp < stop)/* it's a self reference */
1200 		    continue;
1201 
1202 		/*
1203 		 * ok, the module isn't here yet, we
1204 		 * are not finished
1205 		 */
1206 		if (modlist_lookup2(modname, verinfo) == NULL)
1207 		    resolves = 0;
1208 	    }
1209 	}
1210 	/*
1211 	 * OK, if we found our modules, we can link.  So, "provide"
1212 	 * the modules inside and add it to the end of the link order
1213 	 * list.
1214 	 */
1215 	if (resolves) {
1216 	    if (!error) {
1217 		for (mdp = start; mdp < stop; mdp++) {
1218 		    mp = *mdp;
1219 		    if (mp->md_type != MDT_VERSION)
1220 			continue;
1221 		    modname = mp->md_cval;
1222 		    nver = ((struct mod_version *)mp->md_data)->mv_version;
1223 		    if (modlist_lookup(modname, nver) != NULL) {
1224 			kprintf("module %s already present!\n", modname);
1225 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1226 			linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
1227 			/* we changed tailq next ptr */
1228 			goto restart;
1229 		    }
1230 		    modlist_newmodule(modname, nver, lf);
1231 		}
1232 	    }
1233 	    TAILQ_REMOVE(&loaded_files, lf, loaded);
1234 	    TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1235 	    /*
1236 	     * Since we provided modules, we need to restart the
1237 	     * sort so that the previous files that depend on us
1238 	     * have a chance. Also, we've busted the tailq next
1239 	     * pointer with the REMOVE.
1240 	     */
1241 	    goto restart;
1242 	}
1243     }
1244 
1245     /*
1246      * At this point, we check to see what could not be resolved..
1247      */
1248     while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1249 	TAILQ_REMOVE(&loaded_files, lf, loaded);
1250 	kprintf("KLD file %s is missing dependencies\n", lf->filename);
1251 	linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
1252     }
1253 
1254     /*
1255      * We made it. Finish off the linking in the order we determined.
1256      */
1257     TAILQ_FOREACH_MUTABLE(lf, &depended_files, loaded, nlf) {
1258 	if (linker_kernel_file) {
1259 	    linker_kernel_file->refs++;
1260 	    linker_file_add_dependancy(lf, linker_kernel_file);
1261 	}
1262 	lf->userrefs++;
1263 
1264 	error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL);
1265 	if (!error) {
1266 	    for (mdp = start; mdp < stop; mdp++) {
1267 		mp = *mdp;
1268 		if (mp->md_type != MDT_DEPEND)
1269 		    continue;
1270 		modname = mp->md_cval;
1271 		verinfo = mp->md_data;
1272 		mod = modlist_lookup2(modname, verinfo);
1273 		/* Don't count self-dependencies */
1274 		if (lf == mod->container)
1275 		    continue;
1276 		mod->container->refs++;
1277 		linker_file_add_dependancy(lf, mod->container);
1278 	    }
1279 	}
1280 	/*
1281 	 * Now do relocation etc using the symbol search paths
1282 	 * established by the dependencies
1283 	 */
1284 	error = lf->ops->preload_finish(lf);
1285 	if (error) {
1286 	    TAILQ_REMOVE(&depended_files, lf, loaded);
1287 	    kprintf("KLD file %s - could not finalize loading\n",
1288 		    lf->filename);
1289 	    linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */);
1290 	    continue;
1291 	}
1292 	linker_file_register_modules(lf);
1293 	if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0)
1294 	    sysinit_add(si_start, si_stop);
1295 	linker_file_register_sysctls(lf);
1296 	lf->flags |= LINKER_FILE_LINKED;
1297     }
1298     /* woohoo! we made it! */
1299 }
1300 
1301 SYSINIT(preload, SI_BOOT2_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1302 
1303 /*
1304  * Search for a not-loaded module by name.
1305  *
1306  * Modules may be found in the following locations:
1307  *
1308  * - preloaded (result is just the module name)
1309  * - on disk (result is full path to module)
1310  *
1311  * If the module name is qualified in any way (contains path, etc.)
1312  * the we simply return a copy of it.
1313  *
1314  * The search path can be manipulated via sysctl.  Note that we use the ';'
1315  * character as a separator to be consistent with the bootloader.
1316  */
1317 
1318 static char linker_path[MAXPATHLEN] = "/boot;/boot/modules;/;/modules";
1319 
1320 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1321 	      sizeof(linker_path), "module load search path");
1322 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1323 
1324 char *
1325 linker_search_path(const char *name)
1326 {
1327     struct nlookupdata	nd;
1328     char		*cp, *ep, *result;
1329     size_t		name_len, prefix_len;
1330     size_t		result_len;
1331     int			sep;
1332     int			error;
1333     enum vtype		type;
1334     const char *exts[] = { "", ".ko", NULL };
1335     const char **ext;
1336 
1337     /* qualified at all? */
1338     if (index(name, '/'))
1339 	return(linker_strdup(name));
1340 
1341     /* traverse the linker path */
1342     cp = linker_path;
1343     name_len = strlen(name);
1344     for (;;) {
1345 
1346 	/* find the end of this component */
1347 	for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
1348 	    ;
1349 	prefix_len = ep - cp;
1350 	/* if this component doesn't end with a slash, add one */
1351 	if (ep == cp || *(ep - 1) != '/')
1352 	    sep = 1;
1353 	else
1354 	    sep = 0;
1355 
1356 	/*
1357 	 * +2+3 : possible separator, plus terminator + possible extension.
1358 	 */
1359 	result = kmalloc(prefix_len + name_len + 2+3, M_LINKER, M_WAITOK);
1360 
1361 	strncpy(result, cp, prefix_len);
1362 	if (sep)
1363 	    result[prefix_len++] = '/';
1364 	strcpy(result + prefix_len, name);
1365 
1366 	result_len = strlen(result);
1367 	for (ext = exts; *ext != NULL; ext++) {
1368 	    strcpy(result + result_len, *ext);
1369 
1370 	    /*
1371 	     * Attempt to open the file, and return the path if we succeed and it's
1372 	     * a regular file.
1373 	     */
1374 	    error = nlookup_init(&nd, result, UIO_SYSSPACE, NLC_FOLLOW|NLC_LOCKVP);
1375 	    if (error == 0)
1376 		error = vn_open(&nd, NULL, FREAD, 0);
1377 	    if (error == 0) {
1378 		type = nd.nl_open_vp->v_type;
1379 		if (type == VREG) {
1380 		    nlookup_done(&nd);
1381 		    return (result);
1382 		}
1383 	    }
1384 	    nlookup_done(&nd);
1385 	}
1386 
1387 	kfree(result, M_LINKER);
1388 
1389 	if (*ep == 0)
1390 	    break;
1391 	cp = ep + 1;
1392     }
1393     return(NULL);
1394 }
1395 
1396 /*
1397  * Find a file which contains given module and load it, if "parent" is not
1398  * NULL, register a reference to it.
1399  */
1400 static int
1401 linker_load_module(const char *kldname, const char *modname,
1402 		   struct linker_file *parent, struct mod_depend *verinfo,
1403 		   struct linker_file **lfpp)
1404 {
1405     linker_file_t   lfdep;
1406     const char     *filename;
1407     char           *pathname;
1408     int		    error;
1409 
1410     if (modname == NULL) {
1411 	/*
1412 	 * We have to load KLD
1413 	 */
1414 	KASSERT(verinfo == NULL, ("linker_load_module: verinfo is not NULL"));
1415 	pathname = linker_search_path(kldname);
1416     } else {
1417 	if (modlist_lookup2(modname, verinfo) != NULL)
1418 	    return (EEXIST);
1419 	if (kldname != NULL)
1420 	    pathname = linker_strdup(kldname);
1421 	else if (rootvnode == NULL)
1422 	    pathname = NULL;
1423 	else
1424 	    pathname = linker_search_path(modname);
1425 #if 0
1426 	/*
1427 	 * Need to find a KLD with required module
1428 	 */
1429 	pathname = linker_search_module(modname,
1430 					strlen(modname), verinfo);
1431 #endif
1432     }
1433     if (pathname == NULL)
1434 	return (ENOENT);
1435 
1436     /*
1437      * Can't load more than one file with the same basename XXX:
1438      * Actually it should be possible to have multiple KLDs with
1439      * the same basename but different path because they can
1440      * provide different versions of the same modules.
1441      */
1442     filename = rindex(pathname, '/');
1443     if (filename == NULL)
1444 	filename = filename;
1445     else
1446 	filename++;
1447     if (linker_find_file_by_name(filename))
1448 	error = EEXIST;
1449     else
1450 	do {
1451 	    error = linker_load_file(pathname, &lfdep);
1452 	    if (error)
1453 		break;
1454 	    if (modname && verinfo && modlist_lookup2(modname, verinfo) == NULL) {
1455 		linker_file_unload(lfdep /* , LINKER_UNLOAD_FORCE */ );
1456 		error = ENOENT;
1457 		break;
1458 	    }
1459 	    if (parent) {
1460 		linker_file_add_dependancy(parent, lfdep);
1461 	    }
1462 	    if (lfpp)
1463 		*lfpp = lfdep;
1464 	} while (0);
1465     kfree(pathname, M_LINKER);
1466     return (error);
1467 }
1468 
1469 /*
1470  * This routine is responsible for finding dependencies of userland initiated
1471  * kldload(2)'s of files.
1472  */
1473 int
1474 linker_load_dependencies(linker_file_t lf)
1475 {
1476     linker_file_t   lfdep;
1477     struct mod_metadata **start, **stop, **mdp, **nmdp;
1478     struct mod_metadata *mp, *nmp;
1479     struct mod_depend *verinfo;
1480     modlist_t	    mod;
1481     const char     *modname, *nmodname;
1482     int		    ver, error = 0, count;
1483 
1484     /*
1485      * All files are dependant on /kernel.
1486      */
1487     if (linker_kernel_file) {
1488 	linker_kernel_file->refs++;
1489 	linker_file_add_dependancy(lf, linker_kernel_file);
1490     }
1491     if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, &count) != 0)
1492 	return (0);
1493     for (mdp = start; mdp < stop; mdp++) {
1494 	mp = *mdp;
1495 	if (mp->md_type != MDT_VERSION)
1496 	    continue;
1497 	modname = mp->md_cval;
1498 	ver = ((struct mod_version *)mp->md_data)->mv_version;
1499 	mod = modlist_lookup(modname, ver);
1500 	if (mod != NULL) {
1501 	    kprintf("interface %s.%d already present in the KLD '%s'!\n",
1502 		    modname, ver, mod->container->filename);
1503 	    return (EEXIST);
1504 	}
1505     }
1506 
1507     for (mdp = start; mdp < stop; mdp++) {
1508 	mp = *mdp;
1509 	if (mp->md_type != MDT_DEPEND)
1510 	    continue;
1511 	modname = mp->md_cval;
1512 	verinfo = mp->md_data;
1513 	nmodname = NULL;
1514 	for (nmdp = start; nmdp < stop; nmdp++) {
1515 	    nmp = *nmdp;
1516 	    if (nmp->md_type != MDT_VERSION)
1517 		continue;
1518 	    nmodname = nmp->md_cval;
1519 	    if (strcmp(modname, nmodname) == 0)
1520 		break;
1521 	}
1522 	if (nmdp < stop)	/* early exit, it's a self reference */
1523 	    continue;
1524 	mod = modlist_lookup2(modname, verinfo);
1525 	if (mod) {		/* woohoo, it's loaded already */
1526 	    lfdep = mod->container;
1527 	    lfdep->refs++;
1528 	    linker_file_add_dependancy(lf, lfdep);
1529 	    continue;
1530 	}
1531 	error = linker_load_module(NULL, modname, lf, verinfo, NULL);
1532 	if (error) {
1533 	    kprintf("KLD %s: depends on %s - not available or version mismatch\n",
1534 		    lf->filename, modname);
1535 	    break;
1536 	}
1537     }
1538 
1539     if (error)
1540 	return (error);
1541     linker_addmodules(lf, start, stop, 0);
1542     return (error);
1543 }
1544