xref: /freebsd/sys/kern/kern_linker.c (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
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 static int
241 linker_file_register_modules(linker_file_t lf)
242 {
243     int error, mcount;
244     struct linker_set *modules;
245     struct mod_metadata **mdpp;
246     const moduledata_t *moddata;
247     struct sysinit **sipp;
248 
249     KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n",
250 		   lf->filename));
251 
252     modules = (struct linker_set*)
253 	linker_file_lookup_symbol(lf, "modmetadata_set", 0);
254     mcount = 0;
255     if (modules) {
256 	for (mdpp = (struct mod_metadata**)modules->ls_items; *mdpp; mdpp++) {
257 	    if ((*mdpp)->md_type != MDT_MODULE)
258 		continue;
259 	    mcount++;
260 	    moddata = (*mdpp)->md_data;
261 	    KLD_DPF(FILE, ("Registering module %s in %s\n",
262                  moddata->name, lf->filename));
263 	    error = module_register(moddata, lf);
264 	    if (error)
265 		printf("Module %s failed to register: %d\n", moddata->name, error);
266 	}
267     }
268     if (mcount)
269 	return mcount;	/* Do not mix old and new style */
270 
271     /* Hack - handle old kld's without metadata */
272     modules = (struct linker_set*)
273 	linker_file_lookup_symbol(lf, "sysinit_set", 0);
274     if (modules) {
275 	for (sipp = (struct sysinit **)modules->ls_items; *sipp; sipp++) {
276 	    if ((*sipp)->func != module_register_init)
277 		continue;
278 	    mcount++;
279 	    moddata = (*sipp)->udata;
280 	    printf("Old-style KLD file %s found\n", moddata->name);
281 	    error = module_register(moddata, lf);
282 	    if (error)
283 		printf("Old-style KLD file %s failed to register: %d\n", moddata->name, error);
284 	}
285     }
286     return mcount;
287 }
288 
289 static void
290 linker_init_kernel_modules(void)
291 {
292     linker_file_register_modules(linker_kernel_file);
293 }
294 
295 SYSINIT(linker_kernel, SI_SUB_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)
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     for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
319 	KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n",
320 		       filename, lc->desc));
321 	error = LINKER_LOAD_FILE(lc, filename, &lf);
322 	/*
323 	 * If we got something other than ENOENT, then it exists but we cannot
324 	 * load it for some other reason.
325 	 */
326 	if (error != ENOENT)
327 	    foundfile = 1;
328 	if (lf) {
329 	    linker_file_register_modules(lf);
330 	    linker_file_register_sysctls(lf);
331 	    linker_file_sysinit(lf);
332 	    lf->flags |= LINKER_FILE_LINKED;
333 
334 	    *result = lf;
335 	    error = 0;
336 	    goto out;
337 	}
338     }
339     /*
340      * Less than ideal, but tells the user whether it failed to load or
341      * the module was not found.
342      */
343     if (foundfile)
344 	error = ENOEXEC;	/* Format not recognised (or unloadable) */
345     else
346 	error = ENOENT;		/* Nothing found */
347 
348 out:
349     return error;
350 }
351 
352 linker_file_t
353 linker_find_file_by_name(const char* filename)
354 {
355     linker_file_t lf = 0;
356     char *koname;
357 
358     koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
359     if (koname == NULL)
360 	goto out;
361     sprintf(koname, "%s.ko", filename);
362 
363     lockmgr(&lock, LK_SHARED, 0, curproc);
364     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
365 	if (!strcmp(lf->filename, koname))
366 	    break;
367 	if (!strcmp(lf->filename, filename))
368 	    break;
369     }
370     lockmgr(&lock, LK_RELEASE, 0, curproc);
371 
372 out:
373     if (koname)
374 	free(koname, M_LINKER);
375     return lf;
376 }
377 
378 linker_file_t
379 linker_find_file_by_id(int fileid)
380 {
381     linker_file_t lf = 0;
382 
383     lockmgr(&lock, LK_SHARED, 0, curproc);
384     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link))
385 	if (lf->id == fileid)
386 	    break;
387     lockmgr(&lock, LK_RELEASE, 0, curproc);
388 
389     return lf;
390 }
391 
392 linker_file_t
393 linker_make_file(const char* pathname, linker_class_t lc)
394 {
395     linker_file_t lf = 0;
396     const char *filename;
397 
398     filename = linker_basename(pathname);
399 
400     KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
401     lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
402     lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK);
403     if (!lf)
404 	goto out;
405 
406     lf->refs = 1;
407     lf->userrefs = 0;
408     lf->flags = 0;
409     lf->filename = linker_strdup(filename);
410     lf->id = next_file_id++;
411     lf->ndeps = 0;
412     lf->deps = NULL;
413     STAILQ_INIT(&lf->common);
414     TAILQ_INIT(&lf->modules);
415 
416     TAILQ_INSERT_TAIL(&linker_files, lf, link);
417 
418 out:
419     lockmgr(&lock, LK_RELEASE, 0, curproc);
420     return lf;
421 }
422 
423 int
424 linker_file_unload(linker_file_t file)
425 {
426     module_t mod, next;
427     modlist_t ml, nextml;
428     struct common_symbol* cp;
429     int error = 0;
430     int i;
431 
432     /* Refuse to unload modules if securelevel raised */
433     if (securelevel > 0)
434 	return EPERM;
435 
436     KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
437     lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
438     if (file->refs == 1) {
439 	KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
440 	/*
441 	 * Inform any modules associated with this file.
442 	 */
443 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
444 	    next = module_getfnext(mod);
445 
446 	    /*
447 	     * Give the module a chance to veto the unload.
448 	     */
449 	    if ((error = module_unload(mod)) != 0) {
450 		KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n",
451 			       mod));
452 		lockmgr(&lock, LK_RELEASE, 0, curproc);
453 		goto out;
454 	    }
455 
456 	    module_release(mod);
457 	}
458     }
459 
460     file->refs--;
461     if (file->refs > 0) {
462 	lockmgr(&lock, LK_RELEASE, 0, curproc);
463 	goto out;
464     }
465 
466     for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) {
467 	nextml = TAILQ_NEXT(ml, link);
468 	if (ml->container == file) {
469 	    TAILQ_REMOVE(&found_modules, ml, link);
470 	}
471     }
472 
473     /* Don't try to run SYSUNINITs if we are unloaded due to a link error */
474     if (file->flags & LINKER_FILE_LINKED) {
475 	linker_file_sysuninit(file);
476 	linker_file_unregister_sysctls(file);
477     }
478 
479     TAILQ_REMOVE(&linker_files, file, link);
480     lockmgr(&lock, LK_RELEASE, 0, curproc);
481 
482     if (file->deps) {
483 	for (i = 0; i < file->ndeps; i++)
484 	    linker_file_unload(file->deps[i]);
485 	free(file->deps, M_LINKER);
486 	file->deps = NULL;
487     }
488 
489     for (cp = STAILQ_FIRST(&file->common); cp;
490 	 cp = STAILQ_FIRST(&file->common)) {
491 	STAILQ_REMOVE(&file->common, cp, common_symbol, link);
492 	free(cp, M_LINKER);
493     }
494 
495     LINKER_UNLOAD(file);
496     if (file->filename) {
497 	free(file->filename, M_LINKER);
498 	file->filename = NULL;
499     }
500     kobj_delete((kobj_t) file, M_LINKER);
501 
502 out:
503     return error;
504 }
505 
506 int
507 linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
508 {
509     linker_file_t* newdeps;
510 
511     newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*),
512 		     M_LINKER, M_WAITOK);
513     if (newdeps == NULL)
514 	return ENOMEM;
515     bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*));
516 
517     if (file->deps) {
518 	bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
519 	free(file->deps, M_LINKER);
520     }
521     file->deps = newdeps;
522     file->deps[file->ndeps] = dep;
523     file->ndeps++;
524 
525     return 0;
526 }
527 
528 caddr_t
529 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps)
530 {
531     c_linker_sym_t sym;
532     linker_symval_t symval;
533     caddr_t address;
534     size_t common_size = 0;
535     int i;
536 
537     KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n",
538 		  file, name, deps));
539 
540     if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
541 	LINKER_SYMBOL_VALUES(file, sym, &symval);
542 	if (symval.value == 0)
543 	    /*
544 	     * For commons, first look them up in the dependancies and
545 	     * only allocate space if not found there.
546 	     */
547 	    common_size = symval.size;
548 	else {
549 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value));
550 	    return symval.value;
551 	}
552     }
553 
554     if (deps) {
555 	for (i = 0; i < file->ndeps; i++) {
556 	    address = linker_file_lookup_symbol(file->deps[i], name, 0);
557 	    if (address) {
558 		KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address));
559 		return address;
560 	    }
561 	}
562     }
563 
564     if (common_size > 0) {
565 	/*
566 	 * This is a common symbol which was not found in the
567 	 * dependancies.  We maintain a simple common symbol table in
568 	 * the file object.
569 	 */
570 	struct common_symbol* cp;
571 
572 	for (cp = STAILQ_FIRST(&file->common); cp;
573 	     cp = STAILQ_NEXT(cp, link))
574 	    if (!strcmp(cp->name, name)) {
575 		KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address));
576 		return cp->address;
577 	    }
578 
579 	/*
580 	 * Round the symbol size up to align.
581 	 */
582 	common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
583 	cp = malloc(sizeof(struct common_symbol)
584 		    + common_size
585 		    + strlen(name) + 1,
586 		    M_LINKER, M_WAITOK);
587 	if (!cp) {
588 	    KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
589 	    return 0;
590 	}
591 	bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1);
592 
593 	cp->address = (caddr_t) (cp + 1);
594 	cp->name = cp->address + common_size;
595 	strcpy(cp->name, name);
596 	bzero(cp->address, common_size);
597 	STAILQ_INSERT_TAIL(&file->common, cp, link);
598 
599 	KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address));
600 	return cp->address;
601     }
602 
603     KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
604     return 0;
605 }
606 
607 #ifdef DDB
608 /*
609  * DDB Helpers.  DDB has to look across multiple files with their own
610  * symbol tables and string tables.
611  *
612  * Note that we do not obey list locking protocols here.  We really don't
613  * need DDB to hang because somebody's got the lock held.  We'll take the
614  * chance that the files list is inconsistant instead.
615  */
616 
617 int
618 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
619 {
620     linker_file_t lf;
621 
622     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
623 	if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
624 	    return 0;
625     }
626     return ENOENT;
627 }
628 
629 int
630 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
631 {
632     linker_file_t lf;
633     u_long off = (uintptr_t)value;
634     u_long diff, bestdiff;
635     c_linker_sym_t best;
636     c_linker_sym_t es;
637 
638     best = 0;
639     bestdiff = off;
640     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
641 	if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
642 	    continue;
643 	if (es != 0 && diff < bestdiff) {
644 	    best = es;
645 	    bestdiff = diff;
646 	}
647 	if (bestdiff == 0)
648 	    break;
649     }
650     if (best) {
651 	*sym = best;
652 	*diffp = bestdiff;
653 	return 0;
654     } else {
655 	*sym = 0;
656 	*diffp = off;
657 	return ENOENT;
658     }
659 }
660 
661 int
662 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
663 {
664     linker_file_t lf;
665 
666     for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
667 	if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
668 	    return 0;
669     }
670     return ENOENT;
671 }
672 
673 #endif
674 
675 /*
676  * Syscalls.
677  */
678 
679 int
680 kldload(struct proc* p, struct kldload_args* uap)
681 {
682     char* pathname, *realpath;
683     const char *filename;
684     linker_file_t lf;
685     int error = 0;
686 
687     p->p_retval[0] = -1;
688 
689     if (securelevel > 0)	/* redundant, but that's OK */
690 	return EPERM;
691 
692     if ((error = suser(p)) != 0)
693 	return error;
694 
695     realpath = NULL;
696     pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
697     if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
698 	goto out;
699 
700     realpath = linker_search_path(pathname);
701     if (realpath == NULL) {
702 	error = ENOENT;
703 	goto out;
704     }
705     /* Can't load more than one file with the same name */
706     filename = linker_basename(realpath);
707     if (linker_find_file_by_name(filename)) {
708 	error = EEXIST;
709 	goto out;
710     }
711 
712     if ((error = linker_load_file(realpath, &lf)) != 0)
713 	goto out;
714 
715     lf->userrefs++;
716     p->p_retval[0] = lf->id;
717 
718 out:
719     if (pathname)
720 	free(pathname, M_TEMP);
721     if (realpath)
722 	free(realpath, M_LINKER);
723     return error;
724 }
725 
726 int
727 kldunload(struct proc* p, struct kldunload_args* uap)
728 {
729     linker_file_t lf;
730     int error = 0;
731 
732     if (securelevel > 0)	/* redundant, but that's OK */
733 	return EPERM;
734 
735     if ((error = suser(p)) != 0)
736 	return error;
737 
738     lf = linker_find_file_by_id(SCARG(uap, fileid));
739     if (lf) {
740 	KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
741 	if (lf->userrefs == 0) {
742 	    printf("kldunload: attempt to unload file that was loaded by the kernel\n");
743 	    error = EBUSY;
744 	    goto out;
745 	}
746 	lf->userrefs--;
747 	error = linker_file_unload(lf);
748 	if (error)
749 	    lf->userrefs++;
750     } else
751 	error = ENOENT;
752 
753 out:
754     return error;
755 }
756 
757 int
758 kldfind(struct proc* p, struct kldfind_args* uap)
759 {
760     char* pathname;
761     const char *filename;
762     linker_file_t lf;
763     int error = 0;
764 
765     p->p_retval[0] = -1;
766 
767     pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
768     if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
769 	goto out;
770 
771     filename = linker_basename(pathname);
772 
773     lf = linker_find_file_by_name(filename);
774     if (lf)
775 	p->p_retval[0] = lf->id;
776     else
777 	error = ENOENT;
778 
779 out:
780     if (pathname)
781 	free(pathname, M_TEMP);
782     return error;
783 }
784 
785 int
786 kldnext(struct proc* p, struct kldnext_args* uap)
787 {
788     linker_file_t lf;
789     int error = 0;
790 
791     if (SCARG(uap, fileid) == 0) {
792 	if (TAILQ_FIRST(&linker_files))
793 	    p->p_retval[0] = TAILQ_FIRST(&linker_files)->id;
794 	else
795 	    p->p_retval[0] = 0;
796 	return 0;
797     }
798 
799     lf = linker_find_file_by_id(SCARG(uap, fileid));
800     if (lf) {
801 	if (TAILQ_NEXT(lf, link))
802 	    p->p_retval[0] = TAILQ_NEXT(lf, link)->id;
803 	else
804 	    p->p_retval[0] = 0;
805     } else
806 	error = ENOENT;
807 
808     return error;
809 }
810 
811 int
812 kldstat(struct proc* p, struct kldstat_args* uap)
813 {
814     linker_file_t lf;
815     int error = 0;
816     int version;
817     struct kld_file_stat* stat;
818     int namelen;
819 
820     lf = linker_find_file_by_id(SCARG(uap, fileid));
821     if (!lf) {
822 	error = ENOENT;
823 	goto out;
824     }
825 
826     stat = SCARG(uap, stat);
827 
828     /*
829      * Check the version of the user's structure.
830      */
831     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
832 	goto out;
833     if (version != sizeof(struct kld_file_stat)) {
834 	error = EINVAL;
835 	goto out;
836     }
837 
838     namelen = strlen(lf->filename) + 1;
839     if (namelen > MAXPATHLEN)
840 	namelen = MAXPATHLEN;
841     if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
842 	goto out;
843     if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
844 	goto out;
845     if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
846 	goto out;
847     if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0)
848 	goto out;
849     if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
850 	goto out;
851 
852     p->p_retval[0] = 0;
853 
854 out:
855     return error;
856 }
857 
858 int
859 kldfirstmod(struct proc* p, struct kldfirstmod_args* uap)
860 {
861     linker_file_t lf;
862     int error = 0;
863 
864     lf = linker_find_file_by_id(SCARG(uap, fileid));
865     if (lf) {
866 	if (TAILQ_FIRST(&lf->modules))
867 	    p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules));
868 	else
869 	    p->p_retval[0] = 0;
870     } else
871 	error = ENOENT;
872 
873     return error;
874 }
875 
876 int
877 kldsym(struct proc *p, struct kldsym_args *uap)
878 {
879     char *symstr = NULL;
880     c_linker_sym_t sym;
881     linker_symval_t symval;
882     linker_file_t lf;
883     struct kld_sym_lookup lookup;
884     int error = 0;
885 
886     if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0)
887 	goto out;
888     if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) {
889 	error = EINVAL;
890 	goto out;
891     }
892 
893     symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
894     if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
895 	goto out;
896 
897     if (SCARG(uap, fileid) != 0) {
898 	lf = linker_find_file_by_id(SCARG(uap, fileid));
899 	if (lf == NULL) {
900 	    error = ENOENT;
901 	    goto out;
902 	}
903 	if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
904 	    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
905 	    lookup.symvalue = (uintptr_t)symval.value;
906 	    lookup.symsize = symval.size;
907 	    error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
908 	} else
909 	    error = ENOENT;
910     } else {
911 	for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
912 	    if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
913 		LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
914 		lookup.symvalue = (uintptr_t)symval.value;
915 		lookup.symsize = symval.size;
916 		error = copyout(&lookup, SCARG(uap, data), sizeof(lookup));
917 		break;
918 	    }
919 	}
920 	if (!lf)
921 	    error = ENOENT;
922     }
923 out:
924     if (symstr)
925 	free(symstr, M_TEMP);
926     return error;
927 }
928 
929 /*
930  * Preloaded module support
931  */
932 
933 static modlist_t
934 modlist_lookup(const char *name)
935 {
936     modlist_t mod;
937 
938     for (mod = TAILQ_FIRST(&found_modules); mod; mod = TAILQ_NEXT(mod, link)) {
939 	if (!strcmp(mod->name, name))
940 	    return mod;
941     }
942     return NULL;
943 }
944 
945 /*
946  * This routine is cheap and nasty but will work for data pointers.
947  */
948 static void *
949 linker_reloc_ptr(linker_file_t lf, void *offset)
950 {
951 	return lf->address + (uintptr_t)offset;
952 }
953 
954 static void
955 linker_preload(void* arg)
956 {
957     caddr_t		modptr;
958     char		*modname;
959     char		*modtype;
960     linker_file_t	lf;
961     linker_class_t	lc;
962     int			error, mcount;
963     struct linker_set	*sysinits;
964     linker_file_list_t	loaded_files;
965     linker_file_list_t	depended_files;
966     struct linker_set	*deps;
967     struct mod_metadata	*mp;
968     int			i;
969     int			resolves;
970     modlist_t		mod;
971 
972     TAILQ_INIT(&loaded_files);
973     TAILQ_INIT(&depended_files);
974     TAILQ_INIT(&found_modules);
975     error = 0;
976 
977     modptr = NULL;
978     while ((modptr = preload_search_next_name(modptr)) != NULL) {
979 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
980 	modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
981 	if (modname == NULL) {
982 	    printf("Preloaded module at %p does not have a name!\n", modptr);
983 	    continue;
984 	}
985 	if (modtype == NULL) {
986 	    printf("Preloaded module at %p does not have a type!\n", modptr);
987 	    continue;
988 	}
989 	printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
990 	lf = NULL;
991 	for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
992 	    error = LINKER_LINK_PRELOAD(lc, modname, &lf);
993 	    if (error) {
994 		lf = NULL;
995 		break;
996 	    }
997 	}
998 	if (lf)
999 	    TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1000     }
1001 
1002     /*
1003      * First get a list of stuff in the kernel.
1004      */
1005     deps = (struct linker_set*)
1006 	linker_file_lookup_symbol(linker_kernel_file, MDT_SETNAME, 0);
1007     if (deps) {
1008 	for (i = 0; i < deps->ls_length; i++) {
1009 	    mp = deps->ls_items[i];
1010 	    if (mp->md_type != MDT_VERSION)
1011 		continue;
1012 	    modname = mp->md_cval;
1013 	    if (modlist_lookup(modname) != NULL) {
1014 		printf("module %s already present!\n", modname);
1015 		/* XXX what can we do? this is a build error. :-( */
1016 		continue;
1017 	    }
1018 	    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1019 	    if (mod == NULL)
1020 		panic("no memory for module list");
1021 	    bzero(mod, sizeof(*mod));
1022 	    mod->container = linker_kernel_file;
1023 	    mod->name = modname;
1024 	    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1025 	}
1026     }
1027 
1028     /*
1029      * this is a once-off kinky bubble sort
1030      * resolve relocation dependency requirements
1031      */
1032 restart:
1033     for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1034 	deps = (struct linker_set*)
1035 	    linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1036 	/*
1037 	 * First, look to see if we would successfully link with this stuff.
1038 	 */
1039 	resolves = 1;	/* unless we know otherwise */
1040 	if (deps) {
1041 	    for (i = 0; i < deps->ls_length; i++) {
1042 		mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1043 		if (mp->md_type != MDT_DEPEND)
1044 		    continue;
1045 		modname = linker_reloc_ptr(lf, mp->md_cval);
1046 		if (modlist_lookup(modname) == NULL) {
1047 		    /* ok, the module isn't here yet, we are not finished */
1048 		    resolves = 0;
1049 		}
1050 	    }
1051 	}
1052 	/*
1053 	 * OK, if we found our modules, we can link.  So, "provide" the
1054 	 * modules inside and add it to the end of the link order list.
1055 	 */
1056 	if (resolves) {
1057 	    if (deps) {
1058 		for (i = 0; i < deps->ls_length; i++) {
1059 		    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1060 		    if (mp->md_type != MDT_VERSION)
1061 			continue;
1062 		    modname = linker_reloc_ptr(lf, mp->md_cval);
1063 		    if (modlist_lookup(modname) != NULL) {
1064 			printf("module %s already present!\n", modname);
1065 			linker_file_unload(lf);
1066 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1067 			goto restart;	/* we changed the tailq next ptr */
1068 		    }
1069 		    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1070 		    if (mod == NULL)
1071 			panic("no memory for module list");
1072 		    bzero(mod, sizeof(*mod));
1073 		    mod->container = lf;
1074 		    mod->name = modname;
1075 		    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1076 		}
1077 	    }
1078 	    TAILQ_REMOVE(&loaded_files, lf, loaded);
1079 	    TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1080 	    /*
1081 	     * Since we provided modules, we need to restart the sort so
1082 	     * that the previous files that depend on us have a chance.
1083 	     * Also, we've busted the tailq next pointer with the REMOVE.
1084 	     */
1085 	    goto restart;
1086 	}
1087     }
1088 
1089     /*
1090      * At this point, we check to see what could not be resolved..
1091      */
1092     for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1093 	printf("KLD file %s is missing dependencies\n", lf->filename);
1094 	linker_file_unload(lf);
1095 	TAILQ_REMOVE(&loaded_files, lf, loaded);
1096     }
1097 
1098     /*
1099      * We made it. Finish off the linking in the order we determined.
1100      */
1101     for (lf = TAILQ_FIRST(&depended_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
1102 	if (linker_kernel_file) {
1103 	    linker_kernel_file->refs++;
1104 	    error = linker_file_add_dependancy(lf, linker_kernel_file);
1105 	    if (error)
1106 		panic("cannot add dependency");
1107 	}
1108 	lf->userrefs++;		/* so we can (try to) kldunload it */
1109 	deps = (struct linker_set*)
1110 	    linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1111 	if (deps) {
1112 	    for (i = 0; i < deps->ls_length; i++) {
1113 		mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1114 		if (mp->md_type != MDT_DEPEND)
1115 		    continue;
1116 		modname = linker_reloc_ptr(lf, mp->md_cval);
1117 		mod = modlist_lookup(modname);
1118 		mod->container->refs++;
1119 		error = linker_file_add_dependancy(lf, mod->container);
1120 		if (error)
1121 		    panic("cannot add dependency");
1122 	    }
1123 	}
1124 
1125 	/* Now do relocation etc using the symbol search paths established by the dependencies */
1126 	error = LINKER_LINK_PRELOAD_FINISH(lf);
1127 	if (error) {
1128 	    printf("KLD file %s - could not finalize loading\n", lf->filename);
1129 	    linker_file_unload(lf);
1130 	    continue;
1131 	}
1132 
1133 	mcount = linker_file_register_modules(lf);
1134 	sysinits = (struct linker_set*)
1135 	    linker_file_lookup_symbol(lf, "sysinit_set", 0);
1136 	if (sysinits)
1137 	    sysinit_add((struct sysinit **)sysinits->ls_items);
1138 	linker_file_register_sysctls(lf);
1139 	lf->flags |= LINKER_FILE_LINKED;
1140     }
1141     /* woohoo! we made it! */
1142 }
1143 
1144 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1145 
1146 /*
1147  * Search for a not-loaded module by name.
1148  *
1149  * Modules may be found in the following locations:
1150  *
1151  * - preloaded (result is just the module name)
1152  * - on disk (result is full path to module)
1153  *
1154  * If the module name is qualified in any way (contains path, etc.)
1155  * the we simply return a copy of it.
1156  *
1157  * The search path can be manipulated via sysctl.  Note that we use the ';'
1158  * character as a separator to be consistent with the bootloader.
1159  */
1160 
1161 static char linker_path[MAXPATHLEN] = "/;/boot/;/modules/";
1162 
1163 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1164 	      sizeof(linker_path), "module load search path");
1165 
1166 static char *linker_ext_list[] = {
1167 	".ko",
1168 	"",
1169 	NULL
1170 };
1171 
1172 static char *
1173 linker_search_path(const char *name)
1174 {
1175     struct nameidata	nd;
1176     struct proc		*p = curproc;	/* XXX */
1177     char		*cp, *ep, *result, **cpp;
1178     int			error, extlen, len, flags;
1179     enum vtype		type;
1180 
1181     /* qualified at all? */
1182     if (index(name, '/'))
1183 	return(linker_strdup(name));
1184 
1185     extlen = 0;
1186     for (cpp = linker_ext_list; *cpp; cpp++) {
1187 	len = strlen(*cpp);
1188 	if (len > extlen)
1189 	    extlen = len;
1190     }
1191     extlen++;	/* trailing '\0' */
1192 
1193     /* traverse the linker path */
1194     cp = linker_path;
1195     len = strlen(name);
1196     for (;;) {
1197 
1198 	/* find the end of this component */
1199 	for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
1200 	    ;
1201 	result = malloc((len + (ep - cp) + extlen), M_LINKER, M_WAITOK);
1202 	if (result == NULL)	/* actually ENOMEM */
1203 	    return(NULL);
1204 	for (cpp = linker_ext_list; *cpp; cpp++) {
1205 	    strncpy(result, cp, ep - cp);
1206 	    strcpy(result + (ep - cp), name);
1207 	    strcat(result, *cpp);
1208 
1209 	    /*
1210 	     * Attempt to open the file, and return the path if we succeed
1211 	     * and it's a regular file.
1212 	     */
1213 	    NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p);
1214 	    flags = FREAD;
1215 	    error = vn_open(&nd, &flags, 0);
1216 	    if (error == 0) {
1217 		NDFREE(&nd, NDF_ONLY_PNBUF);
1218 		type = nd.ni_vp->v_type;
1219 		VOP_UNLOCK(nd.ni_vp, 0, p);
1220 		vn_close(nd.ni_vp, FREAD, p->p_ucred, p);
1221 		if (type == VREG)
1222 		    return(result);
1223 	    }
1224 	}
1225 	free(result, M_LINKER);
1226 
1227 	if (*ep == 0)
1228 	    break;
1229 	cp = ep + 1;
1230     }
1231     return(NULL);
1232 }
1233 
1234 static const char *
1235 linker_basename(const char* path)
1236 {
1237     const char *filename;
1238 
1239     filename = rindex(path, '/');
1240     if (filename == NULL)
1241 	return path;
1242     if (filename[1])
1243 	filename++;
1244     return filename;
1245 }
1246 
1247 /*
1248  * Find a file which contains given module and load it,
1249  * if "parent" is not NULL, register a reference to it.
1250  */
1251 static int
1252 linker_load_module(const char *modname, struct linker_file *parent)
1253 {
1254     linker_file_t lfdep;
1255     const char *filename;
1256     char *pathname;
1257     int error;
1258 
1259     /*
1260      * There will be a system to look up or guess a file name from
1261      * a module name.
1262      * For now we just try to load a file with the same name.
1263      */
1264     pathname = linker_search_path(modname);
1265     if (pathname == NULL)
1266 	return ENOENT;
1267 
1268     /* Can't load more than one file with the same basename */
1269     filename = linker_basename(pathname);
1270     if (linker_find_file_by_name(filename)) {
1271 	error = EEXIST;
1272 	goto out;
1273     }
1274 
1275     do {
1276 	error = linker_load_file(pathname, &lfdep);
1277 	if (error)
1278 	    break;
1279 	if (parent) {
1280 	    error = linker_file_add_dependancy(parent, lfdep);
1281 	    if (error)
1282 		break;
1283 	}
1284     } while(0);
1285 out:
1286     if (pathname)
1287 	free(pathname, M_LINKER);
1288     return error;
1289 }
1290 
1291 /*
1292  * This routine is responsible for finding dependencies of userland
1293  * initiated kldload(2)'s of files.
1294  */
1295 int
1296 linker_load_dependancies(linker_file_t lf)
1297 {
1298     linker_file_t lfdep;
1299     struct linker_set *deps;
1300     struct mod_metadata *mp, *nmp;
1301     modlist_t mod;
1302     char *modname, *nmodname;
1303     int i, j, error = 0;
1304 
1305     /*
1306      * All files are dependant on /kernel.
1307      */
1308     if (linker_kernel_file) {
1309 	linker_kernel_file->refs++;
1310 	error = linker_file_add_dependancy(lf, linker_kernel_file);
1311 	if (error)
1312 	    return error;
1313     }
1314 
1315     deps = (struct linker_set*)
1316 	linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
1317     if (deps != NULL) {
1318 	for (i = 0; i < deps->ls_length; i++) {
1319 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1320 	    if (mp->md_type != MDT_VERSION)
1321 		continue;
1322 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1323 	    if (modlist_lookup(modname) != NULL) {
1324 		printf("module %s already present!\n", modname);
1325 		return EEXIST;
1326 	    }
1327 	}
1328     }
1329     if (deps != NULL) {
1330 	for (i = 0; i < deps->ls_length; i++) {
1331 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1332 	    if (mp->md_type != MDT_DEPEND)
1333 		continue;
1334 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1335 	    nmodname = NULL;
1336 	    for (j = 0; j < deps->ls_length; j++) {
1337 		nmp = linker_reloc_ptr(lf, deps->ls_items[j]);
1338 		if (nmp->md_type != MDT_VERSION)
1339 		    continue;
1340 		nmodname = linker_reloc_ptr(lf, nmp->md_cval);
1341 		if (strcmp(modname, nmodname) == 0)
1342 		    break;
1343 	    }
1344 	    if (j < deps->ls_length)	/* early exit, it's a self reference */
1345 		continue;
1346 	    mod = modlist_lookup(modname);
1347 	    if (mod) {		/* woohoo, it's loaded already */
1348 		lfdep = mod->container;
1349 		lfdep->refs++;
1350 		error = linker_file_add_dependancy(lf, lfdep);
1351 		if (error)
1352 		    break;
1353 		continue;
1354 	    }
1355 	    error = linker_load_module(modname, lf);
1356 	    if (error) {
1357 		printf("KLD %s: depends on %s - not available\n",
1358 		       lf->filename, modname);
1359 		break;
1360 	    }
1361 	}
1362 
1363     }
1364     if (error == 0 && deps) {
1365 	for (i = 0; i < deps->ls_length; i++) {
1366 	    mp = linker_reloc_ptr(lf, deps->ls_items[i]);
1367 	    if (mp->md_type != MDT_VERSION)
1368 		continue;
1369 	    modname = linker_reloc_ptr(lf, mp->md_cval);
1370 	    mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
1371 	    if (mod == NULL)
1372 		panic("no memory for module list");
1373 	    bzero(mod, sizeof(*mod));
1374 	    mod->container = lf;
1375 	    mod->name = modname;
1376 	    TAILQ_INSERT_TAIL(&found_modules, mod, link);
1377 	}
1378     }
1379     return error;
1380 }
1381