xref: /freebsd/sys/kern/kern_linker.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*-
2  * Copyright (c) 1997-2000 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include "opt_ddb.h"
30 
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/sysproto.h>
36 #include <sys/sysent.h>
37 #include <sys/proc.h>
38 #include <sys/lock.h>
39 #include <sys/module.h>
40 #include <sys/linker.h>
41 #include <sys/fcntl.h>
42 #include <sys/libkern.h>
43 #include <sys/namei.h>
44 #include <sys/vnode.h>
45 #include <sys/sysctl.h>
46 
47 
48 #include "linker_if.h"
49 
50 #ifdef KLD_DEBUG
51 int kld_debug = 0;
52 #endif
53 
54 static char *linker_search_path(const char *name);
55 static const char *linker_basename(const char* path);
56 
57 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
58 
59 linker_file_t linker_kernel_file;
60 
61 static struct lock lock;	/* lock for the file list */
62 static linker_class_list_t classes;
63 static linker_file_list_t linker_files;
64 static int next_file_id = 1;
65 
66 /* XXX wrong name; we're looking at version provision tags here, not modules */
67 typedef TAILQ_HEAD(, modlist) modlisthead_t;
68 struct modlist {
69     TAILQ_ENTRY(modlist) link;		/* chain together all modules */
70     linker_file_t	container;
71     const char		*name;
72 };
73 typedef struct modlist	*modlist_t;
74 static modlisthead_t	found_modules;
75 
76 static char *
77 linker_strdup(const char *str)
78 {
79     char	*result;
80 
81     if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
82 	strcpy(result, str);
83     return(result);
84 }
85 
86 static void
87 linker_init(void* arg)
88 {
89     lockinit(&lock, PVM, "klink", 0, 0);
90     TAILQ_INIT(&classes);
91     TAILQ_INIT(&linker_files);
92 }
93 
94 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
95 
96 int
97 linker_add_class(linker_class_t lc)
98 {
99     kobj_class_compile((kobj_class_t) lc);
100     TAILQ_INSERT_TAIL(&classes, lc, link);
101     return 0;
102 }
103 
104 static void
105 linker_file_sysinit(linker_file_t lf)
106 {
107     struct linker_set* sysinits;
108     struct sysinit** sipp;
109     struct sysinit** xipp;
110     struct sysinit* save;
111 
112     KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
113 		   lf->filename));
114 
115     sysinits = (struct linker_set*)
116 	linker_file_lookup_symbol(lf, "sysinit_set", 0);
117 
118     KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits));
119     if (!sysinits)
120 	return;
121     /*
122      * Perform a bubble sort of the system initialization objects by
123      * their subsystem (primary key) and order (secondary key).
124      *
125      * Since some things care about execution order, this is the
126      * operation which ensures continued function.
127      */
128     for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
129 	for (xipp = sipp + 1; *xipp; xipp++) {
130 	    if ((*sipp)->subsystem < (*xipp)->subsystem ||
131 		 ((*sipp)->subsystem == (*xipp)->subsystem &&
132 		  (*sipp)->order <= (*xipp)->order))
133 		continue;	/* skip*/
134 	    save = *sipp;
135 	    *sipp = *xipp;
136 	    *xipp = save;
137 	}
138     }
139 
140 
141     /*
142      * Traverse the (now) ordered list of system initialization tasks.
143      * Perform each task, and continue on to the next task.
144      */
145     for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
146 	if ((*sipp)->subsystem == SI_SUB_DUMMY)
147 	    continue;	/* skip dummy task(s)*/
148 
149 	/* Call function */
150 	(*((*sipp)->func))((*sipp)->udata);
151     }
152 }
153 
154 static void
155 linker_file_sysuninit(linker_file_t lf)
156 {
157     struct linker_set* sysuninits;
158     struct sysinit** sipp;
159     struct sysinit** xipp;
160     struct sysinit* save;
161 
162     KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
163 		   lf->filename));
164 
165     sysuninits = (struct linker_set*)
166 	linker_file_lookup_symbol(lf, "sysuninit_set", 0);
167 
168     KLD_DPF(FILE, ("linker_file_sysuninit: SYSUNINITs %p\n", sysuninits));
169     if (!sysuninits)
170 	return;
171 
172     /*
173      * Perform a reverse bubble sort of the system initialization objects
174      * by their subsystem (primary key) and order (secondary key).
175      *
176      * Since some things care about execution order, this is the
177      * operation which ensures continued function.
178      */
179     for (sipp = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) {
180 	for (xipp = sipp + 1; *xipp; xipp++) {
181 	    if ((*sipp)->subsystem > (*xipp)->subsystem ||
182 		 ((*sipp)->subsystem == (*xipp)->subsystem &&
183 		  (*sipp)->order >= (*xipp)->order))
184 		continue;	/* skip*/
185 	    save = *sipp;
186 	    *sipp = *xipp;
187 	    *xipp = save;
188 	}
189     }
190 
191     /*
192      * Traverse the (now) ordered list of system initialization tasks.
193      * Perform each task, and continue on to the next task.
194      */
195     for (sipp = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) {
196 	if ((*sipp)->subsystem == SI_SUB_DUMMY)
197 	    continue;	/* skip dummy task(s)*/
198 
199 	/* Call function */
200 	(*((*sipp)->func))((*sipp)->udata);
201     }
202 }
203 
204 static void
205 linker_file_register_sysctls(linker_file_t lf)
206 {
207     struct linker_set* sysctls;
208 
209     KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
210 		   lf->filename));
211 
212     sysctls = (struct linker_set*)
213 	linker_file_lookup_symbol(lf, "sysctl_set", 0);
214 
215     KLD_DPF(FILE, ("linker_file_register_sysctls: SYSCTLs %p\n", sysctls));
216     if (!sysctls)
217 	return;
218 
219     sysctl_register_set(sysctls);
220 }
221 
222 static void
223 linker_file_unregister_sysctls(linker_file_t lf)
224 {
225     struct linker_set* sysctls;
226 
227     KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n",
228 		   lf->filename));
229 
230     sysctls = (struct linker_set*)
231 	linker_file_lookup_symbol(lf, "sysctl_set", 0);
232 
233     KLD_DPF(FILE, ("linker_file_unregister_sysctls: SYSCTLs %p\n", sysctls));
234     if (!sysctls)
235 	return;
236 
237     sysctl_unregister_set(sysctls);
238 }
239 
240 extern struct linker_set modmetadata_set;
241 
242 static int
243 linker_file_register_modules(linker_file_t lf)
244 {
245     int error, mcount;
246     struct linker_set *modules;
247     struct mod_metadata **mdpp;
248     const moduledata_t *moddata;
249     struct sysinit **sipp;
250 
251     KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n",
252 		   lf->filename));
253 
254     modules = (struct linker_set*)
255 	linker_file_lookup_symbol(lf, "modmetadata_set", 0);
256 
257     if (!modules && lf == linker_kernel_file)
258 	modules = &modmetadata_set;
259 
260     mcount = 0;
261     if (modules) {
262 	for (mdpp = (struct mod_metadata**)modules->ls_items; *mdpp; mdpp++) {
263 	    if ((*mdpp)->md_type != MDT_MODULE)
264 		continue;
265 	    mcount++;
266 	    moddata = (*mdpp)->md_data;
267 	    KLD_DPF(FILE, ("Registering module %s in %s\n",
268                  moddata->name, lf->filename));
269 	    error = module_register(moddata, lf);
270 	    if (error)
271 		printf("Module %s failed to register: %d\n", moddata->name, error);
272 	}
273     }
274     if (mcount)
275 	return mcount;	/* Do not mix old and new style */
276 
277     /* Hack - handle old kld's without metadata */
278     modules = (struct linker_set*)
279 	linker_file_lookup_symbol(lf, "sysinit_set", 0);
280     if (modules) {
281 	for (sipp = (struct sysinit **)modules->ls_items; *sipp; sipp++) {
282 	    if ((*sipp)->func != module_register_init)
283 		continue;
284 	    mcount++;
285 	    moddata = (*sipp)->udata;
286 	    printf("Old-style KLD file %s found\n", moddata->name);
287 	    error = module_register(moddata, lf);
288 	    if (error)
289 		printf("Old-style KLD file %s failed to register: %d\n", moddata->name, error);
290 	}
291     }
292     return mcount;
293 }
294 
295 static void
296 linker_init_kernel_modules(void)
297 {
298     linker_file_register_modules(linker_kernel_file);
299 }
300 
301 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0);
302 
303 int
304 linker_load_file(const char* filename, linker_file_t* result)
305 {
306     linker_class_t lc;
307     linker_file_t lf;
308     int foundfile, error = 0;
309 
310     /* Refuse to load modules if securelevel raised */
311     if (securelevel > 0)
312 	return EPERM;
313 
314     lf = linker_find_file_by_name(filename);
315     if (lf) {
316 	KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename));
317 	*result = lf;
318 	lf->refs++;
319 	goto out;
320     }
321 
322     lf = NULL;
323     foundfile = 0;
324     for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
325 	KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n",
326 		       filename, lc->desc));
327 	error = LINKER_LOAD_FILE(lc, filename, &lf);
328 	/*
329 	 * If we got something other than ENOENT, then it exists but we cannot
330 	 * load it for some other reason.
331 	 */
332 	if (error != ENOENT)
333 	    foundfile = 1;
334 	if (lf) {
335 	    linker_file_register_modules(lf);
336 	    linker_file_register_sysctls(lf);
337 	    linker_file_sysinit(lf);
338 	    lf->flags |= LINKER_FILE_LINKED;
339 
340 	    *result = lf;
341 	    error = 0;
342 	    goto out;
343 	}
344     }
345     /*
346      * Less than ideal, but tells the user whether it failed to load or
347      * the module was not found.
348      */
349     if (foundfile)
350 	error = ENOEXEC;	/* Format not recognised (or unloadable) */
351     else
352 	error = ENOENT;		/* Nothing found */
353 
354 out:
355     return error;
356 }
357 
358 linker_file_t
359 linker_find_file_by_name(const char* filename)
360 {
361     linker_file_t lf = 0;
362     char *koname;
363 
364     koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
365     if (koname == NULL)
366 	goto out;
367     sprintf(koname, "%s.ko", filename);
368 
369     lockmgr(&lock, LK_SHARED, 0, curproc);
370     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
371 	if (!strcmp(lf->filename, koname))
372 	    break;
373 	if (!strcmp(lf->filename, filename))
374 	    break;
375     }
376     lockmgr(&lock, LK_RELEASE, 0, curproc);
377 
378 out:
379     if (koname)
380 	free(koname, M_LINKER);
381     return lf;
382 }
383 
384 linker_file_t
385 linker_find_file_by_id(int fileid)
386 {
387     linker_file_t lf = 0;
388 
389     lockmgr(&lock, LK_SHARED, 0, curproc);
390     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link))
391 	if (lf->id == fileid)
392 	    break;
393     lockmgr(&lock, LK_RELEASE, 0, curproc);
394 
395     return lf;
396 }
397 
398 linker_file_t
399 linker_make_file(const char* pathname, linker_class_t lc)
400 {
401     linker_file_t lf = 0;
402     const char *filename;
403 
404     filename = linker_basename(pathname);
405 
406     KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
407     lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
408     lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK);
409     if (!lf)
410 	goto out;
411 
412     lf->refs = 1;
413     lf->userrefs = 0;
414     lf->flags = 0;
415     lf->filename = linker_strdup(filename);
416     lf->id = next_file_id++;
417     lf->ndeps = 0;
418     lf->deps = NULL;
419     STAILQ_INIT(&lf->common);
420     TAILQ_INIT(&lf->modules);
421 
422     TAILQ_INSERT_TAIL(&linker_files, lf, link);
423 
424 out:
425     lockmgr(&lock, LK_RELEASE, 0, curproc);
426     return lf;
427 }
428 
429 int
430 linker_file_unload(linker_file_t file)
431 {
432     module_t mod, next;
433     modlist_t ml, nextml;
434     struct common_symbol* cp;
435     int error = 0;
436     int i;
437 
438     /* Refuse to unload modules if securelevel raised */
439     if (securelevel > 0)
440 	return EPERM;
441 
442     KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
443     lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
444     if (file->refs == 1) {
445 	KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
446 	/*
447 	 * Inform any modules associated with this file.
448 	 */
449 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
450 	    next = module_getfnext(mod);
451 
452 	    /*
453 	     * Give the module a chance to veto the unload.
454 	     */
455 	    if ((error = module_unload(mod)) != 0) {
456 		KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n",
457 			       mod));
458 		lockmgr(&lock, LK_RELEASE, 0, curproc);
459 		goto out;
460 	    }
461 
462 	    module_release(mod);
463 	}
464     }
465 
466     file->refs--;
467     if (file->refs > 0) {
468 	lockmgr(&lock, LK_RELEASE, 0, curproc);
469 	goto out;
470     }
471 
472     for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) {
473 	nextml = TAILQ_NEXT(ml, link);
474 	if (ml->container == file) {
475 	    TAILQ_REMOVE(&found_modules, ml, link);
476 	}
477     }
478 
479     /* Don't try to run SYSUNINITs if we are unloaded due to a link error */
480     if (file->flags & LINKER_FILE_LINKED) {
481 	linker_file_sysuninit(file);
482 	linker_file_unregister_sysctls(file);
483     }
484 
485     TAILQ_REMOVE(&linker_files, file, link);
486     lockmgr(&lock, LK_RELEASE, 0, curproc);
487 
488     if (file->deps) {
489 	for (i = 0; i < file->ndeps; i++)
490 	    linker_file_unload(file->deps[i]);
491 	free(file->deps, M_LINKER);
492 	file->deps = NULL;
493     }
494 
495     for (cp = STAILQ_FIRST(&file->common); cp;
496 	 cp = STAILQ_FIRST(&file->common)) {
497 	STAILQ_REMOVE(&file->common, cp, common_symbol, link);
498 	free(cp, M_LINKER);
499     }
500 
501     LINKER_UNLOAD(file);
502     if (file->filename) {
503 	free(file->filename, M_LINKER);
504 	file->filename = NULL;
505     }
506     kobj_delete((kobj_t) file, M_LINKER);
507 
508 out:
509     return error;
510 }
511 
512 int
513 linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
514 {
515     linker_file_t* newdeps;
516 
517     newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*),
518 		     M_LINKER, M_WAITOK);
519     if (newdeps == NULL)
520 	return ENOMEM;
521     bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*));
522 
523     if (file->deps) {
524 	bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
525 	free(file->deps, M_LINKER);
526     }
527     file->deps = newdeps;
528     file->deps[file->ndeps] = dep;
529     file->ndeps++;
530 
531     return 0;
532 }
533 
534 caddr_t
535 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps)
536 {
537     c_linker_sym_t sym;
538     linker_symval_t symval;
539     caddr_t address;
540     size_t common_size = 0;
541     int i;
542 
543     KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n",
544 		  file, name, deps));
545 
546     if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
547 	LINKER_SYMBOL_VALUES(file, sym, &symval);
548 	if (symval.value == 0)
549 	    /*
550 	     * For commons, first look them up in the dependancies and
551 	     * only allocate space if not found there.
552 	     */
553 	    common_size = symval.size;
554 	else {
555 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value));
556 	    return symval.value;
557 	}
558     }
559 
560     if (deps) {
561 	for (i = 0; i < file->ndeps; i++) {
562 	    address = linker_file_lookup_symbol(file->deps[i], name, 0);
563 	    if (address) {
564 		KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address));
565 		return address;
566 	    }
567 	}
568     }
569 
570     if (common_size > 0) {
571 	/*
572 	 * This is a common symbol which was not found in the
573 	 * dependancies.  We maintain a simple common symbol table in
574 	 * the file object.
575 	 */
576 	struct common_symbol* cp;
577 
578 	for (cp = STAILQ_FIRST(&file->common); cp;
579 	     cp = STAILQ_NEXT(cp, link))
580 	    if (!strcmp(cp->name, name)) {
581 		KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address));
582 		return cp->address;
583 	    }
584 
585 	/*
586 	 * Round the symbol size up to align.
587 	 */
588 	common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
589 	cp = malloc(sizeof(struct common_symbol)
590 		    + common_size
591 		    + strlen(name) + 1,
592 		    M_LINKER, M_WAITOK);
593 	if (!cp) {
594 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
595 	    return 0;
596 	}
597 	bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1);
598 
599 	cp->address = (caddr_t) (cp + 1);
600 	cp->name = cp->address + common_size;
601 	strcpy(cp->name, name);
602 	bzero(cp->address, common_size);
603 	STAILQ_INSERT_TAIL(&file->common, cp, link);
604 
605 	KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address));
606 	return cp->address;
607     }
608 
609     KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
610     return 0;
611 }
612 
613 #ifdef DDB
614 /*
615  * DDB Helpers.  DDB has to look across multiple files with their own
616  * symbol tables and string tables.
617  *
618  * Note that we do not obey list locking protocols here.  We really don't
619  * need DDB to hang because somebody's got the lock held.  We'll take the
620  * chance that the files list is inconsistant instead.
621  */
622 
623 int
624 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
625 {
626     linker_file_t lf;
627 
628     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
629 	if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
630 	    return 0;
631     }
632     return ENOENT;
633 }
634 
635 int
636 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
637 {
638     linker_file_t lf;
639     u_long off = (uintptr_t)value;
640     u_long diff, bestdiff;
641     c_linker_sym_t best;
642     c_linker_sym_t es;
643 
644     best = 0;
645     bestdiff = off;
646     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
647 	if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
648 	    continue;
649 	if (es != 0 && diff < bestdiff) {
650 	    best = es;
651 	    bestdiff = diff;
652 	}
653 	if (bestdiff == 0)
654 	    break;
655     }
656     if (best) {
657 	*sym = best;
658 	*diffp = bestdiff;
659 	return 0;
660     } else {
661 	*sym = 0;
662 	*diffp = off;
663 	return ENOENT;
664     }
665 }
666 
667 int
668 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
669 {
670     linker_file_t lf;
671 
672     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
673 	if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
674 	    return 0;
675     }
676     return ENOENT;
677 }
678 
679 #endif
680 
681 /*
682  * Syscalls.
683  */
684 
685 int
686 kldload(struct proc* p, struct kldload_args* uap)
687 {
688     char* pathname, *realpath;
689     const char *filename;
690     linker_file_t lf;
691     int error = 0;
692 
693     p->p_retval[0] = -1;
694 
695     if (securelevel > 0)	/* redundant, but that's OK */
696 	return EPERM;
697 
698     if ((error = suser(p)) != 0)
699 	return error;
700 
701     realpath = NULL;
702     pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
703     if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
704 	goto out;
705 
706     realpath = linker_search_path(pathname);
707     if (realpath == NULL) {
708 	error = ENOENT;
709 	goto out;
710     }
711     /* Can't load more than one file with the same name */
712     filename = linker_basename(realpath);
713     if (linker_find_file_by_name(filename)) {
714 	error = EEXIST;
715 	goto out;
716     }
717 
718     if ((error = linker_load_file(realpath, &lf)) != 0)
719 	goto out;
720 
721     lf->userrefs++;
722     p->p_retval[0] = lf->id;
723 
724 out:
725     if (pathname)
726 	free(pathname, M_TEMP);
727     if (realpath)
728 	free(realpath, M_LINKER);
729     return error;
730 }
731 
732 int
733 kldunload(struct proc* p, struct kldunload_args* uap)
734 {
735     linker_file_t lf;
736     int error = 0;
737 
738     if (securelevel > 0)	/* redundant, but that's OK */
739 	return EPERM;
740 
741     if ((error = suser(p)) != 0)
742 	return error;
743 
744     lf = linker_find_file_by_id(SCARG(uap, fileid));
745     if (lf) {
746 	KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
747 	if (lf->userrefs == 0) {
748 	    printf("kldunload: attempt to unload file that was loaded by the kernel\n");
749 	    error = EBUSY;
750 	    goto out;
751 	}
752 	lf->userrefs--;
753 	error = linker_file_unload(lf);
754 	if (error)
755 	    lf->userrefs++;
756     } else
757 	error = ENOENT;
758 
759 out:
760     return error;
761 }
762 
763 int
764 kldfind(struct proc* p, struct kldfind_args* uap)
765 {
766     char* pathname;
767     const char *filename;
768     linker_file_t lf;
769     int error = 0;
770 
771     p->p_retval[0] = -1;
772 
773     pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
774     if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
775 	goto out;
776 
777     filename = linker_basename(pathname);
778 
779     lf = linker_find_file_by_name(filename);
780     if (lf)
781 	p->p_retval[0] = lf->id;
782     else
783 	error = ENOENT;
784 
785 out:
786     if (pathname)
787 	free(pathname, M_TEMP);
788     return error;
789 }
790 
791 int
792 kldnext(struct proc* p, struct kldnext_args* uap)
793 {
794     linker_file_t lf;
795     int error = 0;
796 
797     if (SCARG(uap, fileid) == 0) {
798 	if (TAILQ_FIRST(&linker_files))
799 	    p->p_retval[0] = TAILQ_FIRST(&linker_files)->id;
800 	else
801 	    p->p_retval[0] = 0;
802 	return 0;
803     }
804 
805     lf = linker_find_file_by_id(SCARG(uap, fileid));
806     if (lf) {
807 	if (TAILQ_NEXT(lf, link))
808 	    p->p_retval[0] = TAILQ_NEXT(lf, link)->id;
809 	else
810 	    p->p_retval[0] = 0;
811     } else
812 	error = ENOENT;
813 
814     return error;
815 }
816 
817 int
818 kldstat(struct proc* p, struct kldstat_args* uap)
819 {
820     linker_file_t lf;
821     int error = 0;
822     int version;
823     struct kld_file_stat* stat;
824     int namelen;
825 
826     lf = linker_find_file_by_id(SCARG(uap, fileid));
827     if (!lf) {
828 	error = ENOENT;
829 	goto out;
830     }
831 
832     stat = SCARG(uap, stat);
833 
834     /*
835      * Check the version of the user's structure.
836      */
837     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
838 	goto out;
839     if (version != sizeof(struct kld_file_stat)) {
840 	error = EINVAL;
841 	goto out;
842     }
843 
844     namelen = strlen(lf->filename) + 1;
845     if (namelen > MAXPATHLEN)
846 	namelen = MAXPATHLEN;
847     if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
848 	goto out;
849     if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
850 	goto out;
851     if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
852 	goto out;
853     if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0)
854 	goto out;
855     if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
856 	goto out;
857 
858     p->p_retval[0] = 0;
859 
860 out:
861     return error;
862 }
863 
864 int
865 kldfirstmod(struct proc* p, struct kldfirstmod_args* uap)
866 {
867     linker_file_t lf;
868     int error = 0;
869 
870     lf = linker_find_file_by_id(SCARG(uap, fileid));
871     if (lf) {
872 	if (TAILQ_FIRST(&lf->modules))
873 	    p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules));
874 	else
875 	    p->p_retval[0] = 0;
876     } else
877 	error = ENOENT;
878 
879     return error;
880 }
881 
882 int
883 kldsym(struct proc *p, struct kldsym_args *uap)
884 {
885     char *symstr = NULL;
886     c_linker_sym_t sym;
887     linker_symval_t symval;
888     linker_file_t lf;
889     struct kld_sym_lookup lookup;
890     int error = 0;
891 
892     if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0)
893 	goto out;
894     if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) {
895 	error = EINVAL;
896 	goto out;
897     }
898 
899     symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
900     if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
901 	goto out;
902 
903     if (SCARG(uap, fileid) != 0) {
904 	lf = linker_find_file_by_id(SCARG(uap, fileid));
905 	if (lf == NULL) {
906 	    error = ENOENT;
907 	    goto out;
908 	}
909 	if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
910 	    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
911 	    lookup.symvalue = (uintptr_t)symval.value;
912 	    lookup.symsize = symval.size;
913 	    error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
914 	} else
915 	    error = ENOENT;
916     } else {
917 	for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
918 	    if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
919 		LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
920 		lookup.symvalue = (uintptr_t)symval.value;
921 		lookup.symsize = symval.size;
922 		error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
923 		break;
924 	    }
925 	}
926 	if (!lf)
927 	    error = ENOENT;
928     }
929 out:
930     if (symstr)
931 	free(symstr, M_TEMP);
932     return error;
933 }
934 
935 /*
936  * Preloaded module support
937  */
938 
939 static modlist_t
940 modlist_lookup(const char *name)
941 {
942     modlist_t mod;
943 
944     for (mod = TAILQ_FIRST(&found_modules); mod; mod = TAILQ_NEXT(mod, link)) {
945 	if (!strcmp(mod->name, name))
946 	    return mod;
947     }
948     return NULL;
949 }
950 
951 /*
952  * This routine is cheap and nasty but will work for data pointers.
953  */
954 static void *
955 linker_reloc_ptr(linker_file_t lf, void *offset)
956 {
957 	return lf->address + (uintptr_t)offset;
958 }
959 
960 static void
961 linker_preload(void* arg)
962 {
963     caddr_t		modptr;
964     char		*modname, *nmodname;
965     char		*modtype;
966     linker_file_t	lf;
967     linker_class_t	lc;
968     int			error, mcount;
969     struct linker_set	*sysinits;
970     linker_file_list_t	loaded_files;
971     linker_file_list_t	depended_files;
972     struct linker_set	*deps;
973     struct mod_metadata	*mp, *nmp;
974     int			i, j;
975     int			resolves;
976     modlist_t		mod;
977 
978     TAILQ_INIT(&loaded_files);
979     TAILQ_INIT(&depended_files);
980     TAILQ_INIT(&found_modules);
981     error = 0;
982 
983     modptr = NULL;
984     while ((modptr = preload_search_next_name(modptr)) != NULL) {
985 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
986 	modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
987 	if (modname == NULL) {
988 	    printf("Preloaded module at %p does not have a name!\n", modptr);
989 	    continue;
990 	}
991 	if (modtype == NULL) {
992 	    printf("Preloaded module at %p does not have a type!\n", modptr);
993 	    continue;
994 	}
995 	printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
996 	lf = NULL;
997 	for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
998 	    error = LINKER_LINK_PRELOAD(lc, modname, &lf);
999 	    if (error) {
1000 		lf = NULL;
1001 		break;
1002 	    }
1003 	}
1004 	if (lf)
1005 	    TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1006     }
1007 
1008     /*
1009      * First get a list of stuff in the kernel.
1010      */
1011     deps = (struct linker_set*)
1012 	linker_file_lookup_symbol(linker_kernel_file, MDT_SETNAME, 0);
1013     if (deps) {
1014 	for (i = 0; i < deps->ls_length; i++) {
1015 	    mp = deps->ls_items[i];
1016 	    if (mp->md_type != MDT_VERSION)
1017 		continue;
1018 	    modname = mp->md_cval;
1019 	    if (modlist_lookup(modname) != NULL) {
1020 		printf("module %s already present!\n", modname);
1021 		/* XXX what can we do? this is a build error. :-( */
1022 		continue;
1023 	    }
1024 	    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1025 	    if (mod == NULL)
1026 		panic("no memory for module list");
1027 	    bzero(mod, sizeof(*mod));
1028 	    mod->container = linker_kernel_file;
1029 	    mod->name = modname;
1030 	    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1031 	}
1032     }
1033 
1034     /*
1035      * this is a once-off kinky bubble sort
1036      * resolve relocation dependency requirements
1037      */
1038 restart:
1039     for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1040 	deps = (struct linker_set*)
1041 	    linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1042 	/*
1043 	 * First, look to see if we would successfully link with this stuff.
1044 	 */
1045 	resolves = 1;	/* unless we know otherwise */
1046 	if (deps) {
1047 	    for (i = 0; i < deps->ls_length; i++) {
1048 		mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1049 		if (mp->md_type != MDT_DEPEND)
1050 		    continue;
1051 		modname = linker_reloc_ptr(lf, mp->md_cval);
1052 		for (j = 0; j < deps->ls_length; j++) {
1053 		    nmp = linker_reloc_ptr(lf, deps->ls_items[j]);
1054 		    if (nmp->md_type != MDT_VERSION)
1055 			continue;
1056 		    nmodname = linker_reloc_ptr(lf, nmp->md_cval);
1057 		    if (strcmp(modname, nmodname) == 0)
1058 			break;
1059 		}
1060 		if (j < deps->ls_length)	/* it's a self reference */
1061 		    continue;
1062 		if (modlist_lookup(modname) == NULL) {
1063 		    /* ok, the module isn't here yet, we are not finished */
1064 		    resolves = 0;
1065 		}
1066 	    }
1067 	}
1068 	/*
1069 	 * OK, if we found our modules, we can link.  So, "provide" the
1070 	 * modules inside and add it to the end of the link order list.
1071 	 */
1072 	if (resolves) {
1073 	    if (deps) {
1074 		for (i = 0; i < deps->ls_length; i++) {
1075 		    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1076 		    if (mp->md_type != MDT_VERSION)
1077 			continue;
1078 		    modname = linker_reloc_ptr(lf, mp->md_cval);
1079 		    if (modlist_lookup(modname) != NULL) {
1080 			printf("module %s already present!\n", modname);
1081 			linker_file_unload(lf);
1082 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1083 			goto restart;	/* we changed the tailq next ptr */
1084 		    }
1085 		    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1086 		    if (mod == NULL)
1087 			panic("no memory for module list");
1088 		    bzero(mod, sizeof(*mod));
1089 		    mod->container = lf;
1090 		    mod->name = modname;
1091 		    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1092 		}
1093 	    }
1094 	    TAILQ_REMOVE(&loaded_files, lf, loaded);
1095 	    TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1096 	    /*
1097 	     * Since we provided modules, we need to restart the sort so
1098 	     * that the previous files that depend on us have a chance.
1099 	     * Also, we've busted the tailq next pointer with the REMOVE.
1100 	     */
1101 	    goto restart;
1102 	}
1103     }
1104 
1105     /*
1106      * At this point, we check to see what could not be resolved..
1107      */
1108     for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1109 	printf("KLD file %s is missing dependencies\n", lf->filename);
1110 	linker_file_unload(lf);
1111 	TAILQ_REMOVE(&loaded_files, lf, loaded);
1112     }
1113 
1114     /*
1115      * We made it. Finish off the linking in the order we determined.
1116      */
1117     for (lf = TAILQ_FIRST(&depended_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1118 	if (linker_kernel_file) {
1119 	    linker_kernel_file->refs++;
1120 	    error = linker_file_add_dependancy(lf, linker_kernel_file);
1121 	    if (error)
1122 		panic("cannot add dependency");
1123 	}
1124 	lf->userrefs++;		/* so we can (try to) kldunload it */
1125 	deps = (struct linker_set*)
1126 	    linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1127 	if (deps) {
1128 	    for (i = 0; i < deps->ls_length; i++) {
1129 		mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1130 		if (mp->md_type != MDT_DEPEND)
1131 		    continue;
1132 		modname = linker_reloc_ptr(lf, mp->md_cval);
1133 		mod = modlist_lookup(modname);
1134 		mod->container->refs++;
1135 		error = linker_file_add_dependancy(lf, mod->container);
1136 		if (error)
1137 		    panic("cannot add dependency");
1138 	    }
1139 	}
1140 
1141 	/* Now do relocation etc using the symbol search paths established by the dependencies */
1142 	error = LINKER_LINK_PRELOAD_FINISH(lf);
1143 	if (error) {
1144 	    printf("KLD file %s - could not finalize loading\n", lf->filename);
1145 	    linker_file_unload(lf);
1146 	    continue;
1147 	}
1148 
1149 	mcount = linker_file_register_modules(lf);
1150 	sysinits = (struct linker_set*)
1151 	    linker_file_lookup_symbol(lf, "sysinit_set", 0);
1152 	if (sysinits)
1153 	    sysinit_add((struct sysinit **)sysinits->ls_items);
1154 	linker_file_register_sysctls(lf);
1155 	lf->flags |= LINKER_FILE_LINKED;
1156     }
1157     /* woohoo! we made it! */
1158 }
1159 
1160 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1161 
1162 /*
1163  * Search for a not-loaded module by name.
1164  *
1165  * Modules may be found in the following locations:
1166  *
1167  * - preloaded (result is just the module name)
1168  * - on disk (result is full path to module)
1169  *
1170  * If the module name is qualified in any way (contains path, etc.)
1171  * the we simply return a copy of it.
1172  *
1173  * The search path can be manipulated via sysctl.  Note that we use the ';'
1174  * character as a separator to be consistent with the bootloader.
1175  */
1176 
1177 static char linker_path[MAXPATHLEN] = "/boot/modules/;/modules/;/boot/kernel/";
1178 
1179 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1180 	      sizeof(linker_path), "module load search path");
1181 
1182 static char *linker_ext_list[] = {
1183 	".ko",
1184 	"",
1185 	NULL
1186 };
1187 
1188 static char *
1189 linker_search_path(const char *name)
1190 {
1191     struct nameidata	nd;
1192     struct proc		*p = curproc;	/* XXX */
1193     char		*cp, *ep, *result, **cpp;
1194     int			error, extlen, len, flags;
1195     enum vtype		type;
1196 
1197     /* qualified at all? */
1198     if (index(name, '/'))
1199 	return(linker_strdup(name));
1200 
1201     extlen = 0;
1202     for (cpp = linker_ext_list; *cpp; cpp++) {
1203 	len = strlen(*cpp);
1204 	if (len > extlen)
1205 	    extlen = len;
1206     }
1207     extlen++;	/* trailing '\0' */
1208 
1209     /* traverse the linker path */
1210     cp = linker_path;
1211     len = strlen(name);
1212     for (;;) {
1213 
1214 	/* find the end of this component */
1215 	for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
1216 	    ;
1217 	result = malloc((len + (ep - cp) + extlen), M_LINKER, M_WAITOK);
1218 	if (result == NULL)	/* actually ENOMEM */
1219 	    return(NULL);
1220 	for (cpp = linker_ext_list; *cpp; cpp++) {
1221 	    strncpy(result, cp, ep - cp);
1222 	    strcpy(result + (ep - cp), name);
1223 	    strcat(result, *cpp);
1224 
1225 	    /*
1226 	     * Attempt to open the file, and return the path if we succeed
1227 	     * and it's a regular file.
1228 	     */
1229 	    NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p);
1230 	    flags = FREAD;
1231 	    error = vn_open(&nd, &flags, 0);
1232 	    if (error == 0) {
1233 		NDFREE(&nd, NDF_ONLY_PNBUF);
1234 		type = nd.ni_vp->v_type;
1235 		VOP_UNLOCK(nd.ni_vp, 0, p);
1236 		vn_close(nd.ni_vp, FREAD, p->p_ucred, p);
1237 		if (type == VREG)
1238 		    return(result);
1239 	    }
1240 	}
1241 	free(result, M_LINKER);
1242 
1243 	if (*ep == 0)
1244 	    break;
1245 	cp = ep + 1;
1246     }
1247     return(NULL);
1248 }
1249 
1250 static const char *
1251 linker_basename(const char* path)
1252 {
1253     const char *filename;
1254 
1255     filename = rindex(path, '/');
1256     if (filename == NULL)
1257 	return path;
1258     if (filename[1])
1259 	filename++;
1260     return filename;
1261 }
1262 
1263 /*
1264  * Find a file which contains given module and load it,
1265  * if "parent" is not NULL, register a reference to it.
1266  */
1267 static int
1268 linker_load_module(const char *modname, struct linker_file *parent)
1269 {
1270     linker_file_t lfdep;
1271     const char *filename;
1272     char *pathname;
1273     int error;
1274 
1275     /*
1276      * There will be a system to look up or guess a file name from
1277      * a module name.
1278      * For now we just try to load a file with the same name.
1279      */
1280     pathname = linker_search_path(modname);
1281     if (pathname == NULL)
1282 	return ENOENT;
1283 
1284     /* Can't load more than one file with the same basename */
1285     filename = linker_basename(pathname);
1286     if (linker_find_file_by_name(filename)) {
1287 	error = EEXIST;
1288 	goto out;
1289     }
1290 
1291     do {
1292 	error = linker_load_file(pathname, &lfdep);
1293 	if (error)
1294 	    break;
1295 	if (parent) {
1296 	    error = linker_file_add_dependancy(parent, lfdep);
1297 	    if (error)
1298 		break;
1299 	}
1300     } while(0);
1301 out:
1302     if (pathname)
1303 	free(pathname, M_LINKER);
1304     return error;
1305 }
1306 
1307 /*
1308  * This routine is responsible for finding dependencies of userland
1309  * initiated kldload(2)'s of files.
1310  */
1311 int
1312 linker_load_dependancies(linker_file_t lf)
1313 {
1314     linker_file_t lfdep;
1315     struct linker_set *deps;
1316     struct mod_metadata *mp, *nmp;
1317     modlist_t mod;
1318     char *modname, *nmodname;
1319     int i, j, error = 0;
1320 
1321     /*
1322      * All files are dependant on /kernel.
1323      */
1324     if (linker_kernel_file) {
1325 	linker_kernel_file->refs++;
1326 	error = linker_file_add_dependancy(lf, linker_kernel_file);
1327 	if (error)
1328 	    return error;
1329     }
1330 
1331     deps = (struct linker_set*)
1332 	linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1333     if (deps != NULL) {
1334 	for (i = 0; i < deps->ls_length; i++) {
1335 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1336 	    if (mp->md_type != MDT_VERSION)
1337 		continue;
1338 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1339 	    if (modlist_lookup(modname) != NULL) {
1340 		printf("module %s already present!\n", modname);
1341 		return EEXIST;
1342 	    }
1343 	}
1344     }
1345     if (deps != NULL) {
1346 	for (i = 0; i < deps->ls_length; i++) {
1347 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1348 	    if (mp->md_type != MDT_DEPEND)
1349 		continue;
1350 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1351 	    nmodname = NULL;
1352 	    for (j = 0; j < deps->ls_length; j++) {
1353 		nmp = linker_reloc_ptr(lf, deps->ls_items[j]);
1354 		if (nmp->md_type != MDT_VERSION)
1355 		    continue;
1356 		nmodname = linker_reloc_ptr(lf, nmp->md_cval);
1357 		if (strcmp(modname, nmodname) == 0)
1358 		    break;
1359 	    }
1360 	    if (j < deps->ls_length)	/* early exit, it's a self reference */
1361 		continue;
1362 	    mod = modlist_lookup(modname);
1363 	    if (mod) {		/* woohoo, it's loaded already */
1364 		lfdep = mod->container;
1365 		lfdep->refs++;
1366 		error = linker_file_add_dependancy(lf, lfdep);
1367 		if (error)
1368 		    break;
1369 		continue;
1370 	    }
1371 	    error = linker_load_module(modname, lf);
1372 	    if (error) {
1373 		printf("KLD %s: depends on %s - not available\n",
1374 		       lf->filename, modname);
1375 		break;
1376 	    }
1377 	}
1378 
1379     }
1380     if (error == 0 && deps) {
1381 	for (i = 0; i < deps->ls_length; i++) {
1382 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1383 	    if (mp->md_type != MDT_VERSION)
1384 		continue;
1385 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1386 	    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1387 	    if (mod == NULL)
1388 		panic("no memory for module list");
1389 	    bzero(mod, sizeof(*mod));
1390 	    mod->container = lf;
1391 	    mod->name = modname;
1392 	    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1393 	}
1394     }
1395     return error;
1396 }
1397