xref: /dflybsd-src/sys/kern/kern_linker.c (revision dae741e33c840b92a8a53bf9f01157ede145e256)
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 
372 linker_file_t
373 linker_find_file_by_name(const char* filename)
374 {
375     linker_file_t lf = 0;
376     char *koname;
377     int i;
378 
379     for (i = strlen(filename); i > 0 && filename[i-1] != '/'; --i)
380 	;
381     filename += i;
382 
383     koname = kmalloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
384     ksprintf(koname, "%s.ko", filename);
385 
386     lockmgr(&lock, LK_SHARED);
387     TAILQ_FOREACH(lf, &linker_files, link) {
388 	if (!strcmp(lf->filename, koname))
389 	    break;
390 	if (!strcmp(lf->filename, filename))
391 	    break;
392     }
393     lockmgr(&lock, LK_RELEASE);
394 
395     if (koname)
396 	kfree(koname, M_LINKER);
397     return lf;
398 }
399 
400 linker_file_t
401 linker_find_file_by_id(int fileid)
402 {
403     linker_file_t lf = 0;
404 
405     lockmgr(&lock, LK_SHARED);
406     TAILQ_FOREACH(lf, &linker_files, link)
407 	if (lf->id == fileid)
408 	    break;
409     lockmgr(&lock, LK_RELEASE);
410 
411     return lf;
412 }
413 
414 int
415 linker_file_foreach(linker_predicate_t *predicate, void *context)
416 {
417     linker_file_t lf;
418     int retval = 0;
419 
420     lockmgr(&lock, LK_SHARED);
421     TAILQ_FOREACH(lf, &linker_files, link) {
422 	retval = predicate(lf, context);
423 	if (retval != 0)
424 	    break;
425     }
426     lockmgr(&lock, LK_RELEASE);
427     return (retval);
428 }
429 
430 linker_file_t
431 linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops)
432 {
433     linker_file_t lf = 0;
434     const char *filename;
435 
436     filename = rindex(pathname, '/');
437     if (filename && filename[1])
438 	filename++;
439     else
440 	filename = pathname;
441 
442     KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
443     lockmgr(&lock, LK_EXCLUSIVE);
444     lf = kmalloc(sizeof(struct linker_file), M_LINKER, M_WAITOK);
445     bzero(lf, sizeof(*lf));
446 
447     lf->refs = 1;
448     lf->userrefs = 0;
449     lf->flags = 0;
450     lf->filename = linker_strdup(filename);
451     lf->id = next_file_id++;
452     lf->ndeps = 0;
453     lf->deps = NULL;
454     STAILQ_INIT(&lf->common);
455     TAILQ_INIT(&lf->modules);
456 
457     lf->priv = priv;
458     lf->ops = ops;
459     TAILQ_INSERT_TAIL(&linker_files, lf, link);
460 
461     lockmgr(&lock, LK_RELEASE);
462     return lf;
463 }
464 
465 int
466 linker_file_unload(linker_file_t file)
467 {
468     module_t mod, next;;
469     modlist_t ml, nextml;
470     struct common_symbol* cp;
471     int error = 0;
472     int i;
473 
474     /* Refuse to unload modules if securelevel raised */
475     if (securelevel > 0 || kernel_mem_readonly)
476 	return EPERM;
477 
478     KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
479 
480     lockmgr(&lock, LK_EXCLUSIVE);
481 
482     /* Easy case of just dropping a reference. */
483     if (file->refs > 1) {
484 	    file->refs--;
485 	    lockmgr(&lock, LK_RELEASE);
486 	    return (0);
487     }
488 
489     KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
490 
491     /*
492      * Inform any modules associated with this file.
493      */
494     mod = TAILQ_FIRST(&file->modules);
495     for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
496 	next = module_getfnext(mod);
497 
498 	/*
499 	 * Give the module a chance to veto the unload.  Note that the
500 	 * act of unloading the module may cause other modules in the
501 	 * same file list to be unloaded recursively.
502 	 */
503 	if ((error = module_unload(mod)) != 0) {
504 	    KLD_DPF(FILE, ("linker_file_unload: module %p vetoes unload\n",
505 			   mod));
506 	    lockmgr(&lock, LK_RELEASE);
507 	    file->refs--;
508 	    goto out;
509 	}
510 	module_release(mod);
511     }
512 
513     TAILQ_FOREACH_MUTABLE(ml, &found_modules, link, nextml) {
514 	if (ml->container == file) {
515 	    TAILQ_REMOVE(&found_modules, ml, link);
516 	    kfree(ml, M_LINKER);
517 	}
518     }
519 
520     /* Don't try to run SYSUNINITs if we are unloaded due to a link error */
521     if (file->flags & LINKER_FILE_LINKED) {
522 	file->flags &= ~LINKER_FILE_LINKED;
523 	lockmgr(&lock, LK_RELEASE);
524 	linker_file_sysuninit(file);
525 	linker_file_unregister_sysctls(file);
526 	lockmgr(&lock, LK_EXCLUSIVE);
527     }
528 
529     TAILQ_REMOVE(&linker_files, file, link);
530 
531     if (file->deps) {
532 	lockmgr(&lock, LK_RELEASE);
533 	for (i = 0; i < file->ndeps; i++)
534 	    linker_file_unload(file->deps[i]);
535 	lockmgr(&lock, LK_EXCLUSIVE);
536 	kfree(file->deps, M_LINKER);
537 	file->deps = NULL;
538     }
539 
540     while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
541 	STAILQ_REMOVE_HEAD(&file->common, link);
542 	kfree(cp, M_LINKER);
543     }
544 
545     file->ops->unload(file);
546 
547     if (file->filename) {
548 	kfree(file->filename, M_LINKER);
549 	file->filename = NULL;
550     }
551 
552     kfree(file, M_LINKER);
553 
554     lockmgr(&lock, LK_RELEASE);
555 
556 out:
557     return error;
558 }
559 
560 void
561 linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
562 {
563     linker_file_t* newdeps;
564 
565     newdeps = kmalloc((file->ndeps + 1) * sizeof(linker_file_t*),
566 		     M_LINKER, M_WAITOK | M_ZERO);
567 
568     if (file->deps) {
569 	bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
570 	kfree(file->deps, M_LINKER);
571     }
572     file->deps = newdeps;
573     file->deps[file->ndeps] = dep;
574     file->ndeps++;
575 }
576 
577 /*
578  * Locate a linker set and its contents.
579  * This is a helper function to avoid linker_if.h exposure elsewhere.
580  * Note: firstp and lastp are really void ***
581  */
582 int
583 linker_file_lookup_set(linker_file_t file, const char *name,
584                       void *firstp, void *lastp, int *countp)
585 {
586     return file->ops->lookup_set(file, name, firstp, lastp, countp);
587 }
588 
589 int
590 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps, caddr_t *raddr)
591 {
592     c_linker_sym_t sym;
593     linker_symval_t symval;
594     linker_file_t lf;
595     size_t common_size = 0;
596     int i;
597 
598     KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
599 		  file, name, deps));
600 
601     if (file->ops->lookup_symbol(file, name, &sym) == 0) {
602 	file->ops->symbol_values(file, sym, &symval);
603 
604 	/*
605 	 * XXX Assume a common symbol if its value is 0 and it has a non-zero
606 	 * size, otherwise it could be an absolute symbol with a value of 0.
607 	 */
608 	if (symval.value == 0 && symval.size != 0) {
609 	    /*
610 	     * For commons, first look them up in the dependancies and
611 	     * only allocate space if not found there.
612 	     */
613 	    common_size = symval.size;
614 	} else {
615 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%p\n", symval.value));
616 	    *raddr = symval.value;
617 	    return 0;
618 	}
619     }
620     if (deps) {
621 	for (i = 0; i < file->ndeps; i++) {
622 	    if (linker_file_lookup_symbol(file->deps[i], name, 0, raddr) == 0) {
623 		KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%p\n", *raddr));
624 		return 0;
625 	    }
626 	}
627 
628 	/* If we have not found it in the dependencies, search globally */
629 	TAILQ_FOREACH(lf, &linker_files, link) {
630 	    /* But skip the current file if it's on the list */
631 	    if (lf == file)
632 		continue;
633 	    /* And skip the files we searched above */
634 	    for (i = 0; i < file->ndeps; i++)
635 		if (lf == file->deps[i])
636 		    break;
637 	    if (i < file->ndeps)
638 		continue;
639 	    if (linker_file_lookup_symbol(lf, name, 0, raddr) == 0) {
640 		KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%p\n", *raddr));
641 		return 0;
642 	    }
643 	}
644     }
645 
646     if (common_size > 0) {
647 	/*
648 	 * This is a common symbol which was not found in the
649 	 * dependancies.  We maintain a simple common symbol table in
650 	 * the file object.
651 	 */
652 	struct common_symbol* cp;
653 
654 	STAILQ_FOREACH(cp, &file->common, link)
655 	    if (!strcmp(cp->name, name)) {
656 		KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%p\n", cp->address));
657 		*raddr = cp->address;
658 		return 0;
659 	    }
660 
661 	/*
662 	 * Round the symbol size up to align.
663 	 */
664 	common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
665 	cp = kmalloc(sizeof(struct common_symbol)
666 		    + common_size
667 		    + strlen(name) + 1,
668 		    M_LINKER, M_WAITOK | M_ZERO);
669 
670 	cp->address = (caddr_t) (cp + 1);
671 	cp->name = cp->address + common_size;
672 	strcpy(cp->name, name);
673 	bzero(cp->address, common_size);
674 	STAILQ_INSERT_TAIL(&file->common, cp, link);
675 
676 	KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%p\n", cp->address));
677 	*raddr = cp->address;
678 	return 0;
679     }
680 
681 #ifdef _KERNEL_VIRTUAL
682     *raddr = dlsym(RTLD_NEXT, name);
683     if (*raddr != NULL) {
684 	KLD_DPF(SYM, ("linker_file_lookup_symbol: found dlsym=%p\n", *raddr));
685 	return 0;
686     }
687 #endif
688 
689     KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
690     return ENOENT;
691 }
692 
693 #ifdef DDB
694 /*
695  * DDB Helpers.  DDB has to look across multiple files with their own
696  * symbol tables and string tables.
697  *
698  * Note that we do not obey list locking protocols here.  We really don't
699  * need DDB to hang because somebody's got the lock held.  We'll take the
700  * chance that the files list is inconsistant instead.
701  */
702 
703 int
704 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
705 {
706     linker_file_t lf;
707 
708     TAILQ_FOREACH(lf, &linker_files, link) {
709 	if (lf->ops->lookup_symbol(lf, symstr, sym) == 0)
710 	    return 0;
711     }
712     return ENOENT;
713 }
714 
715 int
716 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
717 {
718     linker_file_t lf;
719     u_long off = (uintptr_t)value;
720     u_long diff, bestdiff;
721     c_linker_sym_t best;
722     c_linker_sym_t es;
723 
724     best = 0;
725     bestdiff = off;
726     TAILQ_FOREACH(lf, &linker_files, link) {
727 	if (lf->ops->search_symbol(lf, value, &es, &diff) != 0)
728 	    continue;
729 	if (es != 0 && diff < bestdiff) {
730 	    best = es;
731 	    bestdiff = diff;
732 	}
733 	if (bestdiff == 0)
734 	    break;
735     }
736     if (best) {
737 	*sym = best;
738 	*diffp = bestdiff;
739 	return 0;
740     } else {
741 	*sym = 0;
742 	*diffp = off;
743 	return ENOENT;
744     }
745 }
746 
747 int
748 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
749 {
750     linker_file_t lf;
751 
752     TAILQ_FOREACH(lf, &linker_files, link) {
753 	if (lf->ops->symbol_values(lf, sym, symval) == 0)
754 	    return 0;
755     }
756     return ENOENT;
757 }
758 
759 #endif
760 
761 /*
762  * Syscalls.
763  *
764  * MPALMOSTSAFE
765  */
766 int
767 sys_kldload(struct kldload_args *uap)
768 {
769     struct thread *td = curthread;
770     char *file;
771     char *kldname, *modname;
772     linker_file_t lf;
773     int error = 0;
774 
775     uap->sysmsg_result = -1;
776 
777     if (securelevel > 0 || kernel_mem_readonly)	/* redundant, but that's OK */
778 	return EPERM;
779 
780     if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
781 	return error;
782 
783     file = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
784     if ((error = copyinstr(uap->file, file, MAXPATHLEN, NULL)) != 0)
785 	goto out;
786 
787     /*
788      * If file does not contain a qualified name or any dot in it
789      * (kldname.ko, or kldname.ver.ko) treat it as an interface
790      * name.
791      */
792     if (index(file, '/') || index(file, '.')) {
793 	kldname = file;
794 	modname = NULL;
795     } else {
796 	kldname = NULL;
797 	modname = file;
798     }
799 
800     get_mplock();
801     error = linker_load_module(kldname, modname, NULL, NULL, &lf);
802     rel_mplock();
803     if (error)
804 	goto out;
805 
806     lf->userrefs++;
807     uap->sysmsg_result = lf->id;
808 
809 out:
810     if (file)
811 	kfree(file, M_TEMP);
812     return error;
813 }
814 
815 /*
816  * MPALMOSTSAFE
817  */
818 int
819 sys_kldunload(struct kldunload_args *uap)
820 {
821     struct thread *td = curthread;
822     linker_file_t lf;
823     int error = 0;
824 
825     if (securelevel > 0 || kernel_mem_readonly)	/* redundant, but that's OK */
826 	return EPERM;
827 
828     if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
829 	return error;
830 
831     get_mplock();
832     lf = linker_find_file_by_id(uap->fileid);
833     if (lf) {
834 	KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
835 	if (lf->userrefs == 0) {
836 	    kprintf("linkerunload: attempt to unload file that was loaded by the kernel\n");
837 	    error = EBUSY;
838 	    goto out;
839 	}
840 	lf->userrefs--;
841 	error = linker_file_unload(lf);
842 	if (error)
843 	    lf->userrefs++;
844     } else {
845 	error = ENOENT;
846     }
847 out:
848     rel_mplock();
849     return error;
850 }
851 
852 /*
853  * MPALMOSTSAFE
854  */
855 int
856 sys_kldfind(struct kldfind_args *uap)
857 {
858     char *filename = NULL, *modulename;
859     linker_file_t lf;
860     int error;
861 
862     uap->sysmsg_result = -1;
863 
864     filename = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
865     if ((error = copyinstr(uap->file, filename, MAXPATHLEN, NULL)) != 0)
866 	goto out;
867 
868     modulename = rindex(filename, '/');
869     if (modulename == NULL)
870 	modulename = filename;
871 
872     get_mplock();
873     lf = linker_find_file_by_name(modulename);
874     if (lf)
875 	uap->sysmsg_result = lf->id;
876     else
877 	error = ENOENT;
878     rel_mplock();
879 
880 out:
881     if (filename)
882 	kfree(filename, M_TEMP);
883     return error;
884 }
885 
886 /*
887  * MPALMOSTSAFE
888  */
889 int
890 sys_kldnext(struct kldnext_args *uap)
891 {
892     linker_file_t lf;
893     int error = 0;
894 
895     get_mplock();
896     if (uap->fileid == 0) {
897 	    lf = TAILQ_FIRST(&linker_files);
898     } else {
899 	    lf = linker_find_file_by_id(uap->fileid);
900 	    if (lf == NULL) {
901 		    error = ENOENT;
902 		    goto out;
903 	    }
904 	    lf = TAILQ_NEXT(lf, link);
905     }
906 
907     /* Skip partially loaded files. */
908     while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) {
909 	    lf = TAILQ_NEXT(lf, link);
910     }
911 
912     if (lf)
913 	uap->sysmsg_result = lf->id;
914     else
915 	uap->sysmsg_result = 0;
916 
917 out:
918     rel_mplock();
919     return error;
920 }
921 
922 /*
923  * MPALMOSTSAFE
924  */
925 int
926 sys_kldstat(struct kldstat_args *uap)
927 {
928     linker_file_t lf;
929     int error = 0;
930     int version;
931     struct kld_file_stat* stat;
932     int namelen;
933 
934     get_mplock();
935     lf = linker_find_file_by_id(uap->fileid);
936     if (!lf) {
937 	error = ENOENT;
938 	goto out;
939     }
940 
941     stat = uap->stat;
942 
943     /*
944      * Check the version of the user's structure.
945      */
946     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
947 	goto out;
948     if (version != sizeof(struct kld_file_stat)) {
949 	error = EINVAL;
950 	goto out;
951     }
952 
953     namelen = strlen(lf->filename) + 1;
954     if (namelen > MAXPATHLEN)
955 	namelen = MAXPATHLEN;
956     if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
957 	goto out;
958     if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
959 	goto out;
960     if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
961 	goto out;
962     if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0)
963 	goto out;
964     if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
965 	goto out;
966 
967     uap->sysmsg_result = 0;
968 
969 out:
970     rel_mplock();
971     return error;
972 }
973 
974 /*
975  * MPALMOSTSAFE
976  */
977 int
978 sys_kldfirstmod(struct kldfirstmod_args *uap)
979 {
980     linker_file_t lf;
981     int error = 0;
982 
983     get_mplock();
984     lf = linker_find_file_by_id(uap->fileid);
985     if (lf) {
986 	if (TAILQ_FIRST(&lf->modules))
987 	    uap->sysmsg_result = module_getid(TAILQ_FIRST(&lf->modules));
988 	else
989 	    uap->sysmsg_result = 0;
990     } else {
991 	error = ENOENT;
992     }
993     rel_mplock();
994 
995     return error;
996 }
997 
998 /*
999  * MPALMOSTSAFE
1000  */
1001 int
1002 sys_kldsym(struct kldsym_args *uap)
1003 {
1004     char *symstr = NULL;
1005     c_linker_sym_t sym;
1006     linker_symval_t symval;
1007     linker_file_t lf;
1008     struct kld_sym_lookup lookup;
1009     int error = 0;
1010 
1011     get_mplock();
1012     if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1013 	goto out;
1014     if (lookup.version != sizeof(lookup) || uap->cmd != KLDSYM_LOOKUP) {
1015 	error = EINVAL;
1016 	goto out;
1017     }
1018 
1019     symstr = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1020     if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1021 	goto out;
1022 
1023     if (uap->fileid != 0) {
1024 	lf = linker_find_file_by_id(uap->fileid);
1025 	if (lf == NULL) {
1026 	    error = ENOENT;
1027 	    goto out;
1028 	}
1029 	if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
1030 	    lf->ops->symbol_values(lf, sym, &symval) == 0) {
1031 	    lookup.symvalue = (uintptr_t)symval.value;
1032 	    lookup.symsize = symval.size;
1033 	    error = copyout(&lookup, uap->data, sizeof(lookup));
1034 	} else
1035 	    error = ENOENT;
1036     } else {
1037 	TAILQ_FOREACH(lf, &linker_files, link) {
1038 	    if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
1039 		lf->ops->symbol_values(lf, sym, &symval) == 0) {
1040 		lookup.symvalue = (uintptr_t)symval.value;
1041 		lookup.symsize = symval.size;
1042 		error = copyout(&lookup, uap->data, sizeof(lookup));
1043 		break;
1044 	    }
1045 	}
1046 	if (!lf)
1047 	    error = ENOENT;
1048     }
1049 out:
1050     rel_mplock();
1051     if (symstr)
1052 	kfree(symstr, M_TEMP);
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 && (ver == 0 || mod->version == ver))
1067 	    return (mod);
1068     }
1069     return (NULL);
1070 }
1071 
1072 static modlist_t
1073 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1074 {
1075     modlist_t	    mod, bestmod;
1076     int		    ver;
1077 
1078     if (verinfo == NULL)
1079 	return (modlist_lookup(name, 0));
1080     bestmod = NULL;
1081     TAILQ_FOREACH(mod, &found_modules, link) {
1082 	if (strcmp(mod->name, name) != 0)
1083 	    continue;
1084 	ver = mod->version;
1085 	if (ver == verinfo->md_ver_preferred)
1086 	    return (mod);
1087 	if (ver >= verinfo->md_ver_minimum &&
1088 		ver <= verinfo->md_ver_maximum &&
1089 		(bestmod == NULL || ver > bestmod->version))
1090 	    bestmod = mod;
1091     }
1092     return (bestmod);
1093 }
1094 
1095 int
1096 linker_reference_module(const char *modname, struct mod_depend *verinfo,
1097     linker_file_t *result)
1098 {
1099     modlist_t mod;
1100     int error;
1101 
1102     lockmgr(&lock, LK_SHARED);
1103     if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
1104         *result = mod->container;
1105         (*result)->refs++;
1106         lockmgr(&lock, LK_RELEASE);
1107         return (0);
1108     }
1109 
1110     lockmgr(&lock, LK_RELEASE);
1111     get_mplock();
1112     error = linker_load_module(NULL, modname, NULL, verinfo, result);
1113     rel_mplock();
1114     return (error);
1115 }
1116 
1117 int
1118 linker_release_module(const char *modname, struct mod_depend *verinfo,
1119     linker_file_t lf)
1120 {
1121     modlist_t mod;
1122     int error;
1123 
1124     lockmgr(&lock, LK_SHARED);
1125     if (lf == NULL) {
1126         KASSERT(modname != NULL,
1127             ("linker_release_module: no file or name"));
1128         mod = modlist_lookup2(modname, verinfo);
1129         if (mod == NULL) {
1130             lockmgr(&lock, LK_RELEASE);
1131             return (ESRCH);
1132         }
1133         lf = mod->container;
1134     } else
1135         KASSERT(modname == NULL && verinfo == NULL,
1136             ("linker_release_module: both file and name"));
1137     lockmgr(&lock, LK_RELEASE);
1138     get_mplock();
1139     error = linker_file_unload(lf);
1140     rel_mplock();
1141     return (error);
1142 }
1143 
1144 static modlist_t
1145 modlist_newmodule(const char *modname, int version, linker_file_t container)
1146 {
1147     modlist_t	    mod;
1148 
1149     mod = kmalloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1150     if (mod == NULL)
1151 	panic("no memory for module list");
1152     mod->container = container;
1153     mod->name = modname;
1154     mod->version = version;
1155     TAILQ_INSERT_TAIL(&found_modules, mod, link);
1156     return (mod);
1157 }
1158 
1159 static void
1160 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1161 		  struct mod_metadata **stop, int preload)
1162 {
1163     struct mod_metadata *mp, **mdp;
1164     const char     *modname;
1165     int		    ver;
1166 
1167     for (mdp = start; mdp < stop; mdp++) {
1168 	mp = *mdp;
1169 	if (mp->md_type != MDT_VERSION)
1170 	    continue;
1171 	modname = mp->md_cval;
1172 	ver = ((struct mod_version *)mp->md_data)->mv_version;
1173 	if (modlist_lookup(modname, ver) != NULL) {
1174 	    kprintf("module %s already present!\n", modname);
1175 	    /* XXX what can we do? this is a build error. :-( */
1176 	    continue;
1177 	}
1178 	modlist_newmodule(modname, ver, lf);
1179     }
1180 }
1181 
1182 static void
1183 linker_preload(void* arg)
1184 {
1185     caddr_t		modptr;
1186     const char		*modname, *nmodname;
1187     char		*modtype;
1188     linker_file_t	lf, nlf;
1189     linker_class_t	lc;
1190     int			error;
1191     linker_file_list_t loaded_files;
1192     linker_file_list_t depended_files;
1193     struct mod_metadata *mp, *nmp;
1194     struct mod_metadata **start, **stop, **mdp, **nmdp;
1195     struct mod_depend *verinfo;
1196     int nver;
1197     int resolves;
1198     modlist_t mod;
1199     struct sysinit	**si_start, **si_stop;
1200 
1201     TAILQ_INIT(&loaded_files);
1202     TAILQ_INIT(&depended_files);
1203     TAILQ_INIT(&found_modules);
1204 
1205     modptr = NULL;
1206     while ((modptr = preload_search_next_name(modptr)) != NULL) {
1207 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1208 	modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1209 	if (modname == NULL) {
1210 	    kprintf("Preloaded module at %p does not have a name!\n", modptr);
1211 	    continue;
1212 	}
1213 	if (modtype == NULL) {
1214 	    kprintf("Preloaded module at %p does not have a type!\n", modptr);
1215 	    continue;
1216 	}
1217 
1218 	if (bootverbose)
1219 		kprintf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
1220 	lf = NULL;
1221 	TAILQ_FOREACH(lc, &classes, link) {
1222 	    error = lc->ops->preload_file(modname, &lf);
1223 	    if (!error)
1224 		break;
1225 	    lf = NULL;
1226 	}
1227 	if (lf)
1228 		TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1229     }
1230 
1231     /*
1232      * First get a list of stuff in the kernel.
1233      */
1234     if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1235 			       &stop, NULL) == 0)
1236 	linker_addmodules(linker_kernel_file, start, stop, 1);
1237 
1238     /*
1239      * This is a once-off kinky bubble sort to resolve relocation
1240      * dependency requirements.
1241      */
1242 restart:
1243     TAILQ_FOREACH(lf, &loaded_files, loaded) {
1244 	error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL);
1245 	/*
1246 	 * First, look to see if we would successfully link with this
1247 	 * stuff.
1248 	 */
1249 	resolves = 1;		/* unless we know otherwise */
1250 	if (!error) {
1251 	    for (mdp = start; mdp < stop; mdp++) {
1252 		mp = *mdp;
1253 		if (mp->md_type != MDT_DEPEND)
1254 		    continue;
1255 		modname = mp->md_cval;
1256 		verinfo = mp->md_data;
1257 		for (nmdp = start; nmdp < stop; nmdp++) {
1258 		    nmp = *nmdp;
1259 		    if (nmp->md_type != MDT_VERSION)
1260 			continue;
1261 		    nmodname = nmp->md_cval;
1262 		    if (strcmp(modname, nmodname) == 0)
1263 			break;
1264 		}
1265 		if (nmdp < stop)/* it's a self reference */
1266 		    continue;
1267 
1268 		/*
1269 		 * ok, the module isn't here yet, we
1270 		 * are not finished
1271 		 */
1272 		if (modlist_lookup2(modname, verinfo) == NULL)
1273 		    resolves = 0;
1274 	    }
1275 	}
1276 	/*
1277 	 * OK, if we found our modules, we can link.  So, "provide"
1278 	 * the modules inside and add it to the end of the link order
1279 	 * list.
1280 	 */
1281 	if (resolves) {
1282 	    if (!error) {
1283 		for (mdp = start; mdp < stop; mdp++) {
1284 		    mp = *mdp;
1285 		    if (mp->md_type != MDT_VERSION)
1286 			continue;
1287 		    modname = mp->md_cval;
1288 		    nver = ((struct mod_version *)mp->md_data)->mv_version;
1289 		    if (modlist_lookup(modname, nver) != NULL) {
1290 			kprintf("module %s already present!\n", modname);
1291 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1292 			linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
1293 			/* we changed tailq next ptr */
1294 			goto restart;
1295 		    }
1296 		    modlist_newmodule(modname, nver, lf);
1297 		}
1298 	    }
1299 	    TAILQ_REMOVE(&loaded_files, lf, loaded);
1300 	    TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1301 	    /*
1302 	     * Since we provided modules, we need to restart the
1303 	     * sort so that the previous files that depend on us
1304 	     * have a chance. Also, we've busted the tailq next
1305 	     * pointer with the REMOVE.
1306 	     */
1307 	    goto restart;
1308 	}
1309     }
1310 
1311     /*
1312      * At this point, we check to see what could not be resolved..
1313      */
1314     while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1315 	TAILQ_REMOVE(&loaded_files, lf, loaded);
1316 	kprintf("KLD file %s is missing dependencies\n", lf->filename);
1317 	linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
1318     }
1319 
1320     /*
1321      * We made it. Finish off the linking in the order we determined.
1322      */
1323     TAILQ_FOREACH_MUTABLE(lf, &depended_files, loaded, nlf) {
1324 	if (linker_kernel_file) {
1325 	    linker_kernel_file->refs++;
1326 	    linker_file_add_dependancy(lf, linker_kernel_file);
1327 	}
1328 	lf->userrefs++;
1329 
1330 	error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL);
1331 	if (!error) {
1332 	    for (mdp = start; mdp < stop; mdp++) {
1333 		mp = *mdp;
1334 		if (mp->md_type != MDT_DEPEND)
1335 		    continue;
1336 		modname = mp->md_cval;
1337 		verinfo = mp->md_data;
1338 		mod = modlist_lookup2(modname, verinfo);
1339 		/* Don't count self-dependencies */
1340 		if (lf == mod->container)
1341 		    continue;
1342 		mod->container->refs++;
1343 		linker_file_add_dependancy(lf, mod->container);
1344 	    }
1345 	}
1346 	/*
1347 	 * Now do relocation etc using the symbol search paths
1348 	 * established by the dependencies
1349 	 */
1350 	error = lf->ops->preload_finish(lf);
1351 	if (error) {
1352 	    TAILQ_REMOVE(&depended_files, lf, loaded);
1353 	    kprintf("KLD file %s - could not finalize loading\n",
1354 		    lf->filename);
1355 	    linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */);
1356 	    continue;
1357 	}
1358 	linker_file_register_modules(lf);
1359 	if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0)
1360 	    sysinit_add(si_start, si_stop);
1361 	linker_file_register_sysctls(lf);
1362 	lf->flags |= LINKER_FILE_LINKED;
1363     }
1364     /* woohoo! we made it! */
1365 }
1366 
1367 SYSINIT(preload, SI_BOOT2_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1368 
1369 /*
1370  * Search for a not-loaded module by name.
1371  *
1372  * Modules may be found in the following locations:
1373  *
1374  * - preloaded (result is just the module name)
1375  * - on disk (result is full path to module)
1376  *
1377  * If the module name is qualified in any way (contains path, etc.)
1378  * the we simply return a copy of it.
1379  *
1380  * The search path can be manipulated via sysctl.  Note that we use the ';'
1381  * character as a separator to be consistent with the bootloader.
1382  */
1383 
1384 static char linker_path[MAXPATHLEN] = "/boot;/boot/modules;/;/modules";
1385 
1386 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1387 	      sizeof(linker_path), "module load search path");
1388 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1389 
1390 char *
1391 linker_search_path(const char *name)
1392 {
1393     struct nlookupdata	nd;
1394     char		*cp, *ep, *result;
1395     size_t		name_len, prefix_len;
1396     size_t		result_len;
1397     int			sep;
1398     int			error;
1399     enum vtype		type;
1400     const char *exts[] = { "", ".ko", NULL };
1401     const char **ext;
1402 
1403     /* qualified at all? */
1404     if (index(name, '/'))
1405 	return(linker_strdup(name));
1406 
1407     /* traverse the linker path */
1408     cp = linker_path;
1409     name_len = strlen(name);
1410     for (;;) {
1411 
1412 	/* find the end of this component */
1413 	for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
1414 	    ;
1415 	prefix_len = ep - cp;
1416 	/* if this component doesn't end with a slash, add one */
1417 	if (ep == cp || *(ep - 1) != '/')
1418 	    sep = 1;
1419 	else
1420 	    sep = 0;
1421 
1422 	/*
1423 	 * +2+3 : possible separator, plus terminator + possible extension.
1424 	 */
1425 	result = kmalloc(prefix_len + name_len + 2+3, M_LINKER, M_WAITOK);
1426 
1427 	strncpy(result, cp, prefix_len);
1428 	if (sep)
1429 	    result[prefix_len++] = '/';
1430 	strcpy(result + prefix_len, name);
1431 
1432 	result_len = strlen(result);
1433 	for (ext = exts; *ext != NULL; ext++) {
1434 	    strcpy(result + result_len, *ext);
1435 
1436 	    /*
1437 	     * Attempt to open the file, and return the path if we succeed and it's
1438 	     * a regular file.
1439 	     */
1440 	    error = nlookup_init(&nd, result, UIO_SYSSPACE, NLC_FOLLOW|NLC_LOCKVP);
1441 	    if (error == 0)
1442 		error = vn_open(&nd, NULL, FREAD, 0);
1443 	    if (error == 0) {
1444 		type = nd.nl_open_vp->v_type;
1445 		if (type == VREG) {
1446 		    nlookup_done(&nd);
1447 		    return (result);
1448 		}
1449 	    }
1450 	    nlookup_done(&nd);
1451 	}
1452 
1453 	kfree(result, M_LINKER);
1454 
1455 	if (*ep == 0)
1456 	    break;
1457 	cp = ep + 1;
1458     }
1459     return(NULL);
1460 }
1461 
1462 /*
1463  * Find a file which contains given module and load it, if "parent" is not
1464  * NULL, register a reference to it.
1465  */
1466 static int
1467 linker_load_module(const char *kldname, const char *modname,
1468 		   struct linker_file *parent, struct mod_depend *verinfo,
1469 		   struct linker_file **lfpp)
1470 {
1471     linker_file_t   lfdep;
1472     const char     *filename;
1473     char           *pathname;
1474     int		    error;
1475 
1476     if (modname == NULL) {
1477 	/*
1478 	 * We have to load KLD
1479 	 */
1480 	KASSERT(verinfo == NULL, ("linker_load_module: verinfo is not NULL"));
1481 	pathname = linker_search_path(kldname);
1482     } else {
1483 	if (modlist_lookup2(modname, verinfo) != NULL)
1484 	    return (EEXIST);
1485 	if (kldname != NULL)
1486 	{
1487 	    pathname = linker_strdup(kldname);
1488 	}
1489 	else if (rootvnode == NULL)
1490 	    pathname = NULL;
1491 	else
1492 	{
1493 	    pathname = linker_search_path(modname);
1494 	}
1495 #if 0
1496 	/*
1497 	 * Need to find a KLD with required module
1498 	 */
1499 	pathname = linker_search_module(modname,
1500 					strlen(modname), verinfo);
1501 #endif
1502     }
1503     if (pathname == NULL)
1504 	return (ENOENT);
1505 
1506     /*
1507      * Can't load more than one file with the same basename XXX:
1508      * Actually it should be possible to have multiple KLDs with
1509      * the same basename but different path because they can
1510      * provide different versions of the same modules.
1511      */
1512     filename = rindex(pathname, '/');
1513     if (filename == NULL)
1514 	filename = filename;
1515     else
1516 	filename++;
1517     if (linker_find_file_by_name(filename))
1518 	error = EEXIST;
1519     else
1520 	do {
1521 	    error = linker_load_file(pathname, &lfdep);
1522 	    if (error)
1523 		break;
1524 	    if (modname && verinfo && modlist_lookup2(modname, verinfo) == NULL) {
1525 		linker_file_unload(lfdep /* , LINKER_UNLOAD_FORCE */ );
1526 		error = ENOENT;
1527 		break;
1528 	    }
1529 	    if (parent) {
1530 		linker_file_add_dependancy(parent, lfdep);
1531 	    }
1532 	    if (lfpp)
1533 		*lfpp = lfdep;
1534 	} while (0);
1535     kfree(pathname, M_LINKER);
1536     return (error);
1537 }
1538 
1539 /*
1540  * This routine is responsible for finding dependencies of userland initiated
1541  * kldload(2)'s of files.
1542  */
1543 int
1544 linker_load_dependencies(linker_file_t lf)
1545 {
1546     linker_file_t   lfdep;
1547     struct mod_metadata **start, **stop, **mdp, **nmdp;
1548     struct mod_metadata *mp, *nmp;
1549     struct mod_depend *verinfo;
1550     modlist_t	    mod;
1551     const char     *modname, *nmodname;
1552     int		    ver, error = 0, count;
1553 
1554     /*
1555      * All files are dependant on /kernel.
1556      */
1557     if (linker_kernel_file) {
1558 	linker_kernel_file->refs++;
1559 	linker_file_add_dependancy(lf, linker_kernel_file);
1560     }
1561     if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, &count) != 0)
1562 	return (0);
1563     for (mdp = start; mdp < stop; mdp++) {
1564 	mp = *mdp;
1565 	if (mp->md_type != MDT_VERSION)
1566 	    continue;
1567 	modname = mp->md_cval;
1568 	ver = ((struct mod_version *)mp->md_data)->mv_version;
1569 	mod = modlist_lookup(modname, ver);
1570 	if (mod != NULL) {
1571 	    kprintf("interface %s.%d already present in the KLD '%s'!\n",
1572 		    modname, ver, mod->container->filename);
1573 	    return (EEXIST);
1574 	}
1575     }
1576 
1577     for (mdp = start; mdp < stop; mdp++) {
1578 	mp = *mdp;
1579 	if (mp->md_type != MDT_DEPEND)
1580 	    continue;
1581 	modname = mp->md_cval;
1582 	verinfo = mp->md_data;
1583 	nmodname = NULL;
1584 	for (nmdp = start; nmdp < stop; nmdp++) {
1585 	    nmp = *nmdp;
1586 	    if (nmp->md_type != MDT_VERSION)
1587 		continue;
1588 	    nmodname = nmp->md_cval;
1589 	    if (strcmp(modname, nmodname) == 0)
1590 		break;
1591 	}
1592 	if (nmdp < stop)	/* early exit, it's a self reference */
1593 	    continue;
1594 	mod = modlist_lookup2(modname, verinfo);
1595 	if (mod) {		/* woohoo, it's loaded already */
1596 	    lfdep = mod->container;
1597 	    lfdep->refs++;
1598 	    linker_file_add_dependancy(lf, lfdep);
1599 	    continue;
1600 	}
1601 	error = linker_load_module(NULL, modname, lf, verinfo, NULL);
1602 	if (error) {
1603 	    kprintf("KLD %s: depends on %s - not available or version mismatch\n",
1604 		    lf->filename, modname);
1605 	    break;
1606 	}
1607     }
1608 
1609     if (error)
1610 	return (error);
1611     linker_addmodules(lf, start, stop, 0);
1612     return (error);
1613 }
1614