xref: /dflybsd-src/sys/kern/kern_linker.c (revision 064e1fb31f522fb9804a689dd25f42073f1b79e5)
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 1.13 2003/11/10 06:12:13 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/lock.h>
40 #include <sys/module.h>
41 #include <sys/linker.h>
42 #include <sys/fcntl.h>
43 #include <sys/libkern.h>
44 #include <sys/namei.h>
45 #include <sys/vnode.h>
46 #include <sys/sysctl.h>
47 
48 #include <vm/vm_zone.h>
49 
50 #ifdef KLD_DEBUG
51 int kld_debug = 0;
52 #endif
53 
54 MALLOC_DEFINE(M_LINKER, "kld", "kernel linker");
55 linker_file_t linker_current_file;
56 linker_file_t linker_kernel_file;
57 
58 static struct lock lock;	/* lock for the file list */
59 static linker_class_list_t classes;
60 static linker_file_list_t linker_files;
61 static int next_file_id = 1;
62 
63 static void
64 linker_init(void* arg)
65 {
66     lockinit(&lock, 0, "klink", 0, 0);
67     TAILQ_INIT(&classes);
68     TAILQ_INIT(&linker_files);
69 }
70 
71 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
72 
73 int
74 linker_add_class(const char* desc, void* priv,
75 		 struct linker_class_ops* ops)
76 {
77     linker_class_t lc;
78 
79     lc = malloc(sizeof(struct linker_class), M_LINKER, M_NOWAIT);
80     if (!lc)
81 	return ENOMEM;
82     bzero(lc, sizeof(*lc));
83 
84     lc->desc = desc;
85     lc->priv = priv;
86     lc->ops = ops;
87     TAILQ_INSERT_HEAD(&classes, lc, link);
88 
89     return 0;
90 }
91 
92 static int
93 linker_file_sysinit(linker_file_t lf)
94 {
95     struct sysinit** start, ** stop;
96     struct sysinit** sipp;
97     struct sysinit** xipp;
98     struct sysinit* save;
99     const moduledata_t *moddata;
100     int error;
101 
102     KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
103 		   lf->filename));
104 
105     if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
106 	return 0; /* XXX is this correct ? No sysinit ? */
107 
108     /* HACK ALERT! */
109     for (sipp = start; sipp < stop; sipp++) {
110 	if ((*sipp)->func == module_register_init) {
111 	    moddata = (*sipp)->udata;
112 	    error = module_register(moddata, lf);
113 	    if (error) {
114 		printf("linker_file_sysinit \"%s\" failed to register! %d\n",
115 		    lf->filename, error);
116 		return error;
117 	    }
118 	}
119     }
120 
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 = start; sipp < stop; sipp++) {
129 	for (xipp = sipp + 1; xipp < stop; 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 = start; sipp < stop; 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     return 0; /* no errors */
153 }
154 
155 static void
156 linker_file_sysuninit(linker_file_t lf)
157 {
158     struct sysinit** start, ** stop;
159     struct sysinit** sipp;
160     struct sysinit** xipp;
161     struct sysinit* save;
162 
163     KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
164 		   lf->filename));
165 
166     if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0)
167 	return;
168 
169     /*
170      * Perform a reverse bubble sort of the system initialization objects
171      * by their subsystem (primary key) and order (secondary key).
172      *
173      * Since some things care about execution order, this is the
174      * operation which ensures continued function.
175      */
176     for (sipp = start; sipp < stop; sipp++) {
177 	for (xipp = sipp + 1; xipp < stop; xipp++) {
178 	    if ((*sipp)->subsystem > (*xipp)->subsystem ||
179 		 ((*sipp)->subsystem == (*xipp)->subsystem &&
180 		  (*sipp)->order >= (*xipp)->order))
181 		continue;	/* skip*/
182 	    save = *sipp;
183 	    *sipp = *xipp;
184 	    *xipp = save;
185 	}
186     }
187 
188 
189     /*
190      * Traverse the (now) ordered list of system initialization tasks.
191      * Perform each task, and continue on to the next task.
192      */
193     for (sipp = start; sipp < stop; sipp++) {
194 	if ((*sipp)->subsystem == SI_SUB_DUMMY)
195 	    continue;	/* skip dummy task(s)*/
196 
197 	/* Call function */
198 	(*((*sipp)->func))((*sipp)->udata);
199     }
200 }
201 
202 static void
203 linker_file_register_sysctls(linker_file_t lf)
204 {
205     struct sysctl_oid **start, **stop, **oidp;
206 
207     KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
208 		   lf->filename));
209 
210     if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
211 	return;
212     for (oidp = start; oidp < stop; oidp++)
213 	sysctl_register_oid(*oidp);
214 }
215 
216 static void
217 linker_file_unregister_sysctls(linker_file_t lf)
218 {
219     struct sysctl_oid **start, **stop, **oidp;
220 
221     KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n",
222 		   lf->filename));
223 
224     if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
225 	return;
226     for (oidp = start; oidp < stop; oidp++)
227 	sysctl_unregister_oid(*oidp);
228 }
229 
230 int
231 linker_load_file(const char* filename, linker_file_t* result)
232 {
233     linker_class_t lc;
234     linker_file_t lf;
235     int foundfile, error = 0;
236     char *koname = NULL;
237 
238     /* Refuse to load modules if securelevel raised */
239     if (securelevel > 0)
240 	return EPERM;
241 
242     lf = linker_find_file_by_name(filename);
243     if (lf) {
244 	KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename));
245 	*result = lf;
246 	lf->refs++;
247 	goto out;
248     }
249 
250     koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
251     if (koname == NULL) {
252 	error = ENOMEM;
253 	goto out;
254     }
255     sprintf(koname, "%s.ko", filename);
256     lf = NULL;
257     foundfile = 0;
258     for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
259 	KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n",
260 		       filename, lc->desc));
261 
262 	error = lc->ops->load_file(koname, &lf);	/* First with .ko */
263 	if (lf == NULL && error == ENOENT)
264 	    error = lc->ops->load_file(filename, &lf);	/* Then try without */
265 	/*
266 	 * If we got something other than ENOENT, then it exists but we cannot
267 	 * load it for some other reason.
268 	 */
269 	if (error != ENOENT)
270 	    foundfile = 1;
271 	if (lf) {
272 	    linker_file_register_sysctls(lf);
273 	    error = linker_file_sysinit(lf);
274 
275 	    *result = lf;
276 	    goto out;
277 	}
278     }
279     /*
280      * Less than ideal, but tells the user whether it failed to load or
281      * the module was not found.
282      */
283     if (foundfile) {
284 	    /*
285 	     * Format not recognized or otherwise unloadable.
286 	     * When loading a module that is statically built into
287 	     * the kernel EEXIST percolates back up as the return
288 	     * value.  Preserve this so that apps like sysinstall
289 	     * can recognize this special case and not post bogus
290 	     * dialog messages.
291 	     */
292 	    if (error != EEXIST)
293 		    error = ENOEXEC;
294     } else
295 	error = ENOENT;		/* Nothing found */
296 
297 out:
298     if (koname)
299 	free(koname, M_LINKER);
300     return error;
301 }
302 
303 linker_file_t
304 linker_find_file_by_name(const char* filename)
305 {
306     linker_file_t lf = 0;
307     char *koname;
308 
309     koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
310     if (koname == NULL)
311 	goto out;
312     sprintf(koname, "%s.ko", filename);
313 
314     lockmgr(&lock, LK_SHARED, 0, curthread);
315     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
316 	if (!strcmp(lf->filename, koname))
317 	    break;
318 	if (!strcmp(lf->filename, filename))
319 	    break;
320     }
321     lockmgr(&lock, LK_RELEASE, 0, curthread);
322 
323 out:
324     if (koname)
325 	free(koname, M_LINKER);
326     return lf;
327 }
328 
329 linker_file_t
330 linker_find_file_by_id(int fileid)
331 {
332     linker_file_t lf = 0;
333 
334     lockmgr(&lock, LK_SHARED, 0, curthread);
335     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link))
336 	if (lf->id == fileid)
337 	    break;
338     lockmgr(&lock, LK_RELEASE, 0, curthread);
339 
340     return lf;
341 }
342 
343 linker_file_t
344 linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops)
345 {
346     linker_file_t lf = 0;
347     int namelen;
348     const char *filename;
349 
350     filename = rindex(pathname, '/');
351     if (filename && filename[1])
352 	filename++;
353     else
354 	filename = pathname;
355 
356     KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
357     lockmgr(&lock, LK_EXCLUSIVE, 0, curthread);
358     namelen = strlen(filename) + 1;
359     lf = malloc(sizeof(struct linker_file) + namelen, M_LINKER, M_WAITOK);
360     if (!lf)
361 	goto out;
362     bzero(lf, sizeof(*lf));
363 
364     lf->refs = 1;
365     lf->userrefs = 0;
366     lf->flags = 0;
367     lf->filename = (char*) (lf + 1);
368     strcpy(lf->filename, filename);
369     lf->id = next_file_id++;
370     lf->ndeps = 0;
371     lf->deps = NULL;
372     STAILQ_INIT(&lf->common);
373     TAILQ_INIT(&lf->modules);
374 
375     lf->priv = priv;
376     lf->ops = ops;
377     TAILQ_INSERT_TAIL(&linker_files, lf, link);
378 
379 out:
380     lockmgr(&lock, LK_RELEASE, 0, curthread);
381     return lf;
382 }
383 
384 int
385 linker_file_unload(linker_file_t file)
386 {
387     module_t mod, next;
388     struct common_symbol* cp;
389     int error = 0;
390     int i;
391 
392     /* Refuse to unload modules if securelevel raised */
393     if (securelevel > 0)
394 	return EPERM;
395 
396     KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
397     lockmgr(&lock, LK_EXCLUSIVE, 0, curthread);
398     if (file->refs == 1) {
399 	KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
400 	/*
401 	 * Inform any modules associated with this file.
402 	 */
403 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
404 	    next = module_getfnext(mod);
405 
406 	    /*
407 	     * Give the module a chance to veto the unload.
408 	     */
409 	    if ((error = module_unload(mod)) != 0) {
410 		KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n",
411 			       mod));
412 		lockmgr(&lock, LK_RELEASE, 0, curthread);
413 		goto out;
414 	    }
415 
416 	    module_release(mod);
417 	}
418     }
419 
420     file->refs--;
421     if (file->refs > 0) {
422 	lockmgr(&lock, LK_RELEASE, 0, curthread);
423 	goto out;
424     }
425 
426     /* Don't try to run SYSUNINITs if we are unloaded due to a link error */
427     if (file->flags & LINKER_FILE_LINKED) {
428 	linker_file_sysuninit(file);
429 	linker_file_unregister_sysctls(file);
430     }
431 
432     TAILQ_REMOVE(&linker_files, file, link);
433     lockmgr(&lock, LK_RELEASE, 0, curthread);
434 
435     for (i = 0; i < file->ndeps; i++)
436 	linker_file_unload(file->deps[i]);
437     free(file->deps, M_LINKER);
438 
439     for (cp = STAILQ_FIRST(&file->common); cp;
440 	 cp = STAILQ_FIRST(&file->common)) {
441 	STAILQ_REMOVE(&file->common, cp, common_symbol, link);
442 	free(cp, M_LINKER);
443     }
444 
445     file->ops->unload(file);
446     free(file, M_LINKER);
447 
448 out:
449     return error;
450 }
451 
452 int
453 linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
454 {
455     linker_file_t* newdeps;
456 
457     newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*),
458 		     M_LINKER, M_WAITOK);
459     if (newdeps == NULL)
460 	return ENOMEM;
461     bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*));
462 
463     if (file->deps) {
464 	bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
465 	free(file->deps, M_LINKER);
466     }
467     file->deps = newdeps;
468     file->deps[file->ndeps] = dep;
469     file->ndeps++;
470 
471     return 0;
472 }
473 
474 /*
475  * Locate a linker set and its contents.
476  * This is a helper function to avoid linker_if.h exposure elsewhere.
477  * Note: firstp and lastp are really void ***
478  */
479 int
480 linker_file_lookup_set(linker_file_t file, const char *name,
481                       void *firstp, void *lastp, int *countp)
482 {
483     return file->ops->lookup_set(file, name, firstp, lastp, countp);
484 }
485 
486 int
487 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps, caddr_t *raddr)
488 {
489     c_linker_sym_t sym;
490     linker_symval_t symval;
491     linker_file_t lf;
492     size_t common_size = 0;
493     int i;
494 
495     KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n",
496 		  file, name, deps));
497 
498     if (file->ops->lookup_symbol(file, name, &sym) == 0) {
499 	file->ops->symbol_values(file, sym, &symval);
500 
501 	/*
502 	 * XXX Assume a common symbol if its value is 0 and it has a non-zero
503 	 * size, otherwise it could be an absolute symbol with a value of 0.
504 	 */
505 	if (symval.value == 0 && symval.size != 0) {
506 	    /*
507 	     * For commons, first look them up in the dependancies and
508 	     * only allocate space if not found there.
509 	     */
510 	    common_size = symval.size;
511 	} else {
512 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value));
513 	    *raddr = symval.value;
514 	    return 0;
515 	}
516     }
517     if (deps) {
518 	for (i = 0; i < file->ndeps; i++) {
519 	    if (linker_file_lookup_symbol(file->deps[i], name, 0, raddr) == 0) {
520 		KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", *raddr));
521 		return 0;
522 	    }
523 	}
524 
525 	/* If we have not found it in the dependencies, search globally */
526 	for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
527 	    /* But skip the current file if it's on the list */
528 	    if (lf == file)
529 		continue;
530 	    /* And skip the files we searched above */
531 	    for (i = 0; i < file->ndeps; i++)
532 		if (lf == file->deps[i])
533 		    break;
534 	    if (i < file->ndeps)
535 		continue;
536 	    if (linker_file_lookup_symbol(lf, name, 0, raddr) == 0) {
537 		KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%x\n", *raddr));
538 		return 0;
539 	    }
540 	}
541     }
542 
543     if (common_size > 0) {
544 	/*
545 	 * This is a common symbol which was not found in the
546 	 * dependancies.  We maintain a simple common symbol table in
547 	 * the file object.
548 	 */
549 	struct common_symbol* cp;
550 
551 	for (cp = STAILQ_FIRST(&file->common); cp;
552 	     cp = STAILQ_NEXT(cp, link))
553 	    if (!strcmp(cp->name, name)) {
554 		KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address));
555 		*raddr = cp->address;
556 		return 0;
557 	    }
558 
559 	/*
560 	 * Round the symbol size up to align.
561 	 */
562 	common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
563 	cp = malloc(sizeof(struct common_symbol)
564 		    + common_size
565 		    + strlen(name) + 1,
566 		    M_LINKER, M_WAITOK);
567 	if (!cp) {
568 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
569 	    return ENOMEM;
570 	}
571 	bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1);
572 
573 	cp->address = (caddr_t) (cp + 1);
574 	cp->name = cp->address + common_size;
575 	strcpy(cp->name, name);
576 	bzero(cp->address, common_size);
577 	STAILQ_INSERT_TAIL(&file->common, cp, link);
578 
579 	KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address));
580 	*raddr = cp->address;
581 	return 0;
582     }
583 
584     KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
585     return ENOENT;
586 }
587 
588 #ifdef DDB
589 /*
590  * DDB Helpers.  DDB has to look across multiple files with their own
591  * symbol tables and string tables.
592  *
593  * Note that we do not obey list locking protocols here.  We really don't
594  * need DDB to hang because somebody's got the lock held.  We'll take the
595  * chance that the files list is inconsistant instead.
596  */
597 
598 int
599 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
600 {
601     linker_file_t lf;
602 
603     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
604 	if (lf->ops->lookup_symbol(lf, symstr, sym) == 0)
605 	    return 0;
606     }
607     return ENOENT;
608 }
609 
610 int
611 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
612 {
613     linker_file_t lf;
614     u_long off = (uintptr_t)value;
615     u_long diff, bestdiff;
616     c_linker_sym_t best;
617     c_linker_sym_t es;
618 
619     best = 0;
620     bestdiff = off;
621     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
622 	if (lf->ops->search_symbol(lf, value, &es, &diff) != 0)
623 	    continue;
624 	if (es != 0 && diff < bestdiff) {
625 	    best = es;
626 	    bestdiff = diff;
627 	}
628 	if (bestdiff == 0)
629 	    break;
630     }
631     if (best) {
632 	*sym = best;
633 	*diffp = bestdiff;
634 	return 0;
635     } else {
636 	*sym = 0;
637 	*diffp = off;
638 	return ENOENT;
639     }
640 }
641 
642 int
643 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
644 {
645     linker_file_t lf;
646 
647     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
648 	if (lf->ops->symbol_values(lf, sym, symval) == 0)
649 	    return 0;
650     }
651     return ENOENT;
652 }
653 
654 #endif
655 
656 /*
657  * Syscalls.
658  */
659 
660 int
661 kldload(struct kldload_args *uap)
662 {
663     struct thread *td = curthread;
664     char* filename = NULL, *modulename;
665     linker_file_t lf;
666     int error = 0;
667 
668     uap->sysmsg_result = -1;
669 
670     if (securelevel > 0)	/* redundant, but that's OK */
671 	return EPERM;
672 
673     if ((error = suser(td)) != 0)
674 	return error;
675 
676     filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
677     if ((error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) != 0)
678 	goto out;
679 
680     /* Can't load more than one module with the same name */
681     modulename = rindex(filename, '/');
682     if (modulename == NULL)
683 	modulename = filename;
684     else
685 	modulename++;
686     if (linker_find_file_by_name(modulename)) {
687 	error = EEXIST;
688 	goto out;
689     }
690 
691     if ((error = linker_load_file(filename, &lf)) != 0)
692 	goto out;
693 
694     lf->userrefs++;
695     uap->sysmsg_result = lf->id;
696 
697 out:
698     if (filename)
699 	free(filename, M_TEMP);
700     return error;
701 }
702 
703 int
704 kldunload(struct kldunload_args *uap)
705 {
706     struct thread *td = curthread;
707     linker_file_t lf;
708     int error = 0;
709 
710     if (securelevel > 0)	/* redundant, but that's OK */
711 	return EPERM;
712 
713     if ((error = suser(td)) != 0)
714 	return error;
715 
716     lf = linker_find_file_by_id(SCARG(uap, fileid));
717     if (lf) {
718 	KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
719 	if (lf->userrefs == 0) {
720 	    printf("linkerunload: attempt to unload file that was loaded by the kernel\n");
721 	    error = EBUSY;
722 	    goto out;
723 	}
724 	lf->userrefs--;
725 	error = linker_file_unload(lf);
726 	if (error)
727 	    lf->userrefs++;
728     } else
729 	error = ENOENT;
730 
731 out:
732     return error;
733 }
734 
735 int
736 kldfind(struct kldfind_args *uap)
737 {
738     char *filename = NULL, *modulename;
739     linker_file_t lf;
740     int error = 0;
741 
742     uap->sysmsg_result = -1;
743 
744     filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
745     if ((error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) != 0)
746 	goto out;
747 
748     modulename = rindex(filename, '/');
749     if (modulename == NULL)
750 	modulename = filename;
751 
752     lf = linker_find_file_by_name(modulename);
753     if (lf)
754 	uap->sysmsg_result = lf->id;
755     else
756 	error = ENOENT;
757 
758 out:
759     if (filename)
760 	free(filename, M_TEMP);
761     return error;
762 }
763 
764 int
765 kldnext(struct kldnext_args *uap)
766 {
767     linker_file_t lf;
768     int error = 0;
769 
770     if (SCARG(uap, fileid) == 0) {
771 	if (TAILQ_FIRST(&linker_files))
772 	    uap->sysmsg_result = TAILQ_FIRST(&linker_files)->id;
773 	else
774 	    uap->sysmsg_result = 0;
775 	return 0;
776     }
777 
778     lf = linker_find_file_by_id(SCARG(uap, fileid));
779     if (lf) {
780 	if (TAILQ_NEXT(lf, link))
781 	    uap->sysmsg_result = TAILQ_NEXT(lf, link)->id;
782 	else
783 	    uap->sysmsg_result = 0;
784     } else
785 	error = ENOENT;
786 
787     return error;
788 }
789 
790 int
791 kldstat(struct kldstat_args *uap)
792 {
793     linker_file_t lf;
794     int error = 0;
795     int version;
796     struct kld_file_stat* stat;
797     int namelen;
798 
799     lf = linker_find_file_by_id(SCARG(uap, fileid));
800     if (!lf) {
801 	error = ENOENT;
802 	goto out;
803     }
804 
805     stat = SCARG(uap, stat);
806 
807     /*
808      * Check the version of the user's structure.
809      */
810     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
811 	goto out;
812     if (version != sizeof(struct kld_file_stat)) {
813 	error = EINVAL;
814 	goto out;
815     }
816 
817     namelen = strlen(lf->filename) + 1;
818     if (namelen > MAXPATHLEN)
819 	namelen = MAXPATHLEN;
820     if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
821 	goto out;
822     if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
823 	goto out;
824     if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
825 	goto out;
826     if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0)
827 	goto out;
828     if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
829 	goto out;
830 
831     uap->sysmsg_result = 0;
832 
833 out:
834     return error;
835 }
836 
837 int
838 kldfirstmod(struct kldfirstmod_args *uap)
839 {
840     linker_file_t lf;
841     int error = 0;
842 
843     lf = linker_find_file_by_id(SCARG(uap, fileid));
844     if (lf) {
845 	if (TAILQ_FIRST(&lf->modules))
846 	    uap->sysmsg_result = module_getid(TAILQ_FIRST(&lf->modules));
847 	else
848 	    uap->sysmsg_result = 0;
849     } else
850 	error = ENOENT;
851 
852     return error;
853 }
854 
855 int
856 kldsym(struct kldsym_args *uap)
857 {
858     char *symstr = NULL;
859     c_linker_sym_t sym;
860     linker_symval_t symval;
861     linker_file_t lf;
862     struct kld_sym_lookup lookup;
863     int error = 0;
864 
865     if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0)
866 	goto out;
867     if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) {
868 	error = EINVAL;
869 	goto out;
870     }
871 
872     symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
873     if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
874 	goto out;
875 
876     if (SCARG(uap, fileid) != 0) {
877 	lf = linker_find_file_by_id(SCARG(uap, fileid));
878 	if (lf == NULL) {
879 	    error = ENOENT;
880 	    goto out;
881 	}
882 	if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
883 	    lf->ops->symbol_values(lf, sym, &symval) == 0) {
884 	    lookup.symvalue = (uintptr_t)symval.value;
885 	    lookup.symsize = symval.size;
886 	    error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
887 	} else
888 	    error = ENOENT;
889     } else {
890 	for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
891 	    if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 &&
892 		lf->ops->symbol_values(lf, sym, &symval) == 0) {
893 		lookup.symvalue = (uintptr_t)symval.value;
894 		lookup.symsize = symval.size;
895 		error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
896 		break;
897 	    }
898 	}
899 	if (!lf)
900 	    error = ENOENT;
901     }
902 out:
903     if (symstr)
904 	free(symstr, M_TEMP);
905     return error;
906 }
907 
908 /*
909  * Preloaded module support
910  */
911 
912 static void
913 linker_preload(void* arg)
914 {
915     caddr_t		modptr;
916     char		*modname;
917     char		*modtype;
918     linker_file_t	lf;
919     linker_class_t	lc;
920     int			error;
921     struct sysinit	**sipp;
922     const moduledata_t	*moddata;
923     struct sysinit	**si_start, **si_stop;
924 
925     modptr = NULL;
926     while ((modptr = preload_search_next_name(modptr)) != NULL) {
927 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
928 	modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
929 	if (modname == NULL) {
930 	    printf("Preloaded module at %p does not have a name!\n", modptr);
931 	    continue;
932 	}
933 	if (modtype == NULL) {
934 	    printf("Preloaded module at %p does not have a type!\n", modptr);
935 	    continue;
936 	}
937 	printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
938 	lf = linker_find_file_by_name(modname);
939 	if (lf) {
940 	    lf->userrefs++;
941 	    continue;
942 	}
943 	lf = NULL;
944 	for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
945 	    error = lc->ops->load_file(modname, &lf);
946 	    if (error) {
947 		lf = NULL;
948 		break;
949 	    }
950 	}
951 	if (lf) {
952 	    lf->userrefs++;
953 
954 	    if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0) {
955 		/* HACK ALERT!
956 		 * This is to set the sysinit moduledata so that the module
957 		 * can attach itself to the correct containing file.
958 		 * The sysinit could be run at *any* time.
959 		 */
960 		for (sipp = si_start; sipp < si_stop; sipp++) {
961 		    if ((*sipp)->func == module_register_init) {
962 			moddata = (*sipp)->udata;
963 			error = module_register(moddata, lf);
964 			if (error)
965 			    printf("Preloaded %s \"%s\" failed to register: %d\n",
966 				modtype, modname, error);
967 		    }
968 		}
969 		sysinit_add(si_start, si_stop);
970 	    }
971 	    linker_file_register_sysctls(lf);
972 	}
973     }
974 }
975 
976 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
977 
978 /*
979  * Search for a not-loaded module by name.
980  *
981  * Modules may be found in the following locations:
982  *
983  * - preloaded (result is just the module name)
984  * - on disk (result is full path to module)
985  *
986  * If the module name is qualified in any way (contains path, etc.)
987  * the we simply return a copy of it.
988  *
989  * The search path can be manipulated via sysctl.  Note that we use the ';'
990  * character as a separator to be consistent with the bootloader.
991  */
992 
993 static char linker_path[MAXPATHLEN] = "/;/boot/;/modules/";
994 
995 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
996 	      sizeof(linker_path), "module load search path");
997 
998 static char *
999 linker_strdup(const char *str)
1000 {
1001     char	*result;
1002 
1003     if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
1004 	strcpy(result, str);
1005     return(result);
1006 }
1007 
1008 char *
1009 linker_search_path(const char *name)
1010 {
1011     struct nameidata	nd;
1012     struct thread	*td = curthread;
1013     char		*cp, *ep, *result;
1014     int			error;
1015     enum vtype		type;
1016 
1017     /* qualified at all? */
1018     if (index(name, '/'))
1019 	return(linker_strdup(name));
1020 
1021     /* traverse the linker path */
1022     cp = linker_path;
1023     for (;;) {
1024 
1025 	/* find the end of this component */
1026 	for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
1027 	    ;
1028 	result = malloc((strlen(name) + (ep - cp) + 1), M_LINKER, M_WAITOK);
1029 	if (result == NULL)	/* actually ENOMEM */
1030 	    return(NULL);
1031 
1032 	strncpy(result, cp, ep - cp);
1033 	strcpy(result + (ep - cp), name);
1034 
1035 	/*
1036 	 * Attempt to open the file, and return the path if we succeed and it's
1037 	 * a regular file.
1038 	 */
1039 	NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, UIO_SYSSPACE, result, td);
1040 	error = vn_open(&nd, FREAD, 0);
1041 	if (error == 0) {
1042 	    NDFREE(&nd, NDF_ONLY_PNBUF);
1043 	    type = nd.ni_vp->v_type;
1044 	    VOP_UNLOCK(nd.ni_vp, 0, td);
1045 	    vn_close(nd.ni_vp, FREAD, td);
1046 	    if (type == VREG)
1047 		return(result);
1048 	}
1049 	free(result, M_LINKER);
1050 
1051 	if (*ep == 0)
1052 	    break;
1053 	cp = ep + 1;
1054     }
1055     return(NULL);
1056 }
1057