1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1997-2000 Doug Rabson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #include "opt_ddb.h"
31 #include "opt_kld.h"
32 #include "opt_hwpmc_hooks.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/boottrace.h>
37 #include <sys/eventhandler.h>
38 #include <sys/fcntl.h>
39 #include <sys/jail.h>
40 #include <sys/kernel.h>
41 #include <sys/libkern.h>
42 #include <sys/linker.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/module.h>
46 #include <sys/mount.h>
47 #include <sys/mutex.h>
48 #include <sys/namei.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/sx.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysctl.h>
54 #include <sys/sysproto.h>
55 #include <sys/vnode.h>
56
57 #ifdef DDB
58 #include <ddb/ddb.h>
59 #endif
60
61 #include <net/vnet.h>
62
63 #include <security/mac/mac_framework.h>
64
65 #include "linker_if.h"
66
67 #ifdef HWPMC_HOOKS
68 #include <sys/pmckern.h>
69 #endif
70
71 #ifdef KLD_DEBUG
72 int kld_debug = 0;
73 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RWTUN,
74 &kld_debug, 0, "Set various levels of KLD debug");
75 #endif
76
77 /* These variables are used by kernel debuggers to enumerate loaded files. */
78 const int kld_off_address = offsetof(struct linker_file, address);
79 const int kld_off_filename = offsetof(struct linker_file, filename);
80 const int kld_off_pathname = offsetof(struct linker_file, pathname);
81 const int kld_off_next = offsetof(struct linker_file, link.tqe_next);
82
83 /*
84 * static char *linker_search_path(const char *name, struct mod_depend
85 * *verinfo);
86 */
87 static const char *linker_basename(const char *path);
88
89 /*
90 * Find a currently loaded file given its filename.
91 */
92 static linker_file_t linker_find_file_by_name(const char* _filename);
93
94 /*
95 * Find a currently loaded file given its file id.
96 */
97 static linker_file_t linker_find_file_by_id(int _fileid);
98
99 /* Metadata from the static kernel */
100 SET_DECLARE(modmetadata_set, struct mod_metadata);
101
102 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
103
104 linker_file_t linker_kernel_file;
105
106 static struct sx kld_sx; /* kernel linker lock */
107 static u_int kld_busy;
108 static struct thread *kld_busy_owner;
109
110 /*
111 * Load counter used by clients to determine if a linker file has been
112 * re-loaded. This counter is incremented for each file load.
113 */
114 static int loadcnt;
115
116 static linker_class_list_t classes;
117 static linker_file_list_t linker_files;
118 static int next_file_id = 1;
119 static int linker_no_more_classes = 0;
120
121 #define LINKER_GET_NEXT_FILE_ID(a) do { \
122 linker_file_t lftmp; \
123 \
124 if (!cold) \
125 sx_assert(&kld_sx, SA_XLOCKED); \
126 retry: \
127 TAILQ_FOREACH(lftmp, &linker_files, link) { \
128 if (next_file_id == lftmp->id) { \
129 next_file_id++; \
130 goto retry; \
131 } \
132 } \
133 (a) = next_file_id; \
134 } while (0)
135
136 /* XXX wrong name; we're looking at version provision tags here, not modules */
137 typedef TAILQ_HEAD(, modlist) modlisthead_t;
138 struct modlist {
139 TAILQ_ENTRY(modlist) link; /* chain together all modules */
140 linker_file_t container;
141 const char *name;
142 int version;
143 };
144 typedef struct modlist *modlist_t;
145 static modlisthead_t found_modules;
146
147 static void linker_file_add_dependency(linker_file_t file,
148 linker_file_t dep);
149 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
150 const char* name, int deps);
151 static int linker_load_module(const char *kldname,
152 const char *modname, struct linker_file *parent,
153 const struct mod_depend *verinfo, struct linker_file **lfpp);
154 static modlist_t modlist_lookup2(const char *name, const struct mod_depend *verinfo);
155
156 static void
linker_init(void * arg)157 linker_init(void *arg)
158 {
159
160 sx_init(&kld_sx, "kernel linker");
161 TAILQ_INIT(&classes);
162 TAILQ_INIT(&linker_files);
163 }
164
165 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, NULL);
166
167 static void
linker_stop_class_add(void * arg)168 linker_stop_class_add(void *arg)
169 {
170
171 linker_no_more_classes = 1;
172 }
173
174 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
175
176 int
linker_add_class(linker_class_t lc)177 linker_add_class(linker_class_t lc)
178 {
179
180 /*
181 * We disallow any class registration past SI_ORDER_ANY
182 * of SI_SUB_KLD. We bump the reference count to keep the
183 * ops from being freed.
184 */
185 if (linker_no_more_classes == 1)
186 return (EPERM);
187 kobj_class_compile((kobj_class_t) lc);
188 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */
189 TAILQ_INSERT_TAIL(&classes, lc, link);
190 return (0);
191 }
192
193 static void
linker_file_sysinit(linker_file_t lf)194 linker_file_sysinit(linker_file_t lf)
195 {
196 struct sysinit **start, **stop, **sipp, **xipp, *save;
197 int last;
198
199 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
200 lf->filename));
201
202 sx_assert(&kld_sx, SA_XLOCKED);
203
204 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
205 return;
206 /*
207 * Perform a bubble sort of the system initialization objects by
208 * their subsystem (primary key) and order (secondary key).
209 *
210 * Since some things care about execution order, this is the operation
211 * which ensures continued function.
212 */
213 for (sipp = start; sipp < stop; sipp++) {
214 for (xipp = sipp + 1; xipp < stop; xipp++) {
215 if ((*sipp)->subsystem < (*xipp)->subsystem ||
216 ((*sipp)->subsystem == (*xipp)->subsystem &&
217 (*sipp)->order <= (*xipp)->order))
218 continue; /* skip */
219 save = *sipp;
220 *sipp = *xipp;
221 *xipp = save;
222 }
223 }
224
225 /*
226 * Traverse the (now) ordered list of system initialization tasks.
227 * Perform each task, and continue on to the next task.
228 */
229 last = SI_SUB_DUMMY;
230 sx_xunlock(&kld_sx);
231 mtx_lock(&Giant);
232 for (sipp = start; sipp < stop; sipp++) {
233 if ((*sipp)->subsystem == SI_SUB_DUMMY)
234 continue; /* skip dummy task(s) */
235
236 if ((*sipp)->subsystem > last)
237 BOOTTRACE("%s: sysinit 0x%7x", lf->filename,
238 (*sipp)->subsystem);
239
240 /* Call function */
241 (*((*sipp)->func)) ((*sipp)->udata);
242 last = (*sipp)->subsystem;
243 }
244 mtx_unlock(&Giant);
245 sx_xlock(&kld_sx);
246 }
247
248 static void
linker_file_sysuninit(linker_file_t lf)249 linker_file_sysuninit(linker_file_t lf)
250 {
251 struct sysinit **start, **stop, **sipp, **xipp, *save;
252 int last;
253
254 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
255 lf->filename));
256
257 sx_assert(&kld_sx, SA_XLOCKED);
258
259 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
260 NULL) != 0)
261 return;
262
263 /*
264 * Perform a reverse bubble sort of the system initialization objects
265 * by their subsystem (primary key) and order (secondary key).
266 *
267 * Since some things care about execution order, this is the operation
268 * which ensures continued function.
269 */
270 for (sipp = start; sipp < stop; sipp++) {
271 for (xipp = sipp + 1; xipp < stop; xipp++) {
272 if ((*sipp)->subsystem > (*xipp)->subsystem ||
273 ((*sipp)->subsystem == (*xipp)->subsystem &&
274 (*sipp)->order >= (*xipp)->order))
275 continue; /* skip */
276 save = *sipp;
277 *sipp = *xipp;
278 *xipp = save;
279 }
280 }
281
282 /*
283 * Traverse the (now) ordered list of system initialization tasks.
284 * Perform each task, and continue on to the next task.
285 */
286 sx_xunlock(&kld_sx);
287 mtx_lock(&Giant);
288 last = SI_SUB_DUMMY;
289 for (sipp = start; sipp < stop; sipp++) {
290 if ((*sipp)->subsystem == SI_SUB_DUMMY)
291 continue; /* skip dummy task(s) */
292
293 if ((*sipp)->subsystem > last)
294 BOOTTRACE("%s: sysuninit 0x%7x", lf->filename,
295 (*sipp)->subsystem);
296
297 /* Call function */
298 (*((*sipp)->func)) ((*sipp)->udata);
299 last = (*sipp)->subsystem;
300 }
301 mtx_unlock(&Giant);
302 sx_xlock(&kld_sx);
303 }
304
305 static void
linker_file_register_sysctls(linker_file_t lf,bool enable)306 linker_file_register_sysctls(linker_file_t lf, bool enable)
307 {
308 struct sysctl_oid **start, **stop, **oidp;
309
310 KLD_DPF(FILE,
311 ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
312 lf->filename));
313
314 sx_assert(&kld_sx, SA_XLOCKED);
315
316 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
317 return;
318
319 sx_xunlock(&kld_sx);
320 sysctl_wlock();
321 for (oidp = start; oidp < stop; oidp++) {
322 if (enable)
323 sysctl_register_oid(*oidp);
324 else
325 sysctl_register_disabled_oid(*oidp);
326 }
327 sysctl_wunlock();
328 sx_xlock(&kld_sx);
329 }
330
331 /*
332 * Invoke the LINKER_CTF_GET implementation for this file. Existing
333 * implementations will load CTF info from the filesystem upon the first call
334 * and cache it in the kernel thereafter.
335 */
336 static void
linker_ctf_load_file(linker_file_t file)337 linker_ctf_load_file(linker_file_t file)
338 {
339 linker_ctf_t lc;
340 int error;
341
342 error = linker_ctf_get(file, &lc);
343 if (error == 0)
344 return;
345 if (bootverbose) {
346 printf("failed to load CTF for %s: %d\n", file->filename,
347 error);
348 }
349 }
350
351 static void
linker_file_enable_sysctls(linker_file_t lf)352 linker_file_enable_sysctls(linker_file_t lf)
353 {
354 struct sysctl_oid **start, **stop, **oidp;
355
356 KLD_DPF(FILE,
357 ("linker_file_enable_sysctls: enable SYSCTLs for %s\n",
358 lf->filename));
359
360 sx_assert(&kld_sx, SA_XLOCKED);
361
362 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
363 return;
364
365 sx_xunlock(&kld_sx);
366 sysctl_wlock();
367 for (oidp = start; oidp < stop; oidp++)
368 sysctl_enable_oid(*oidp);
369 sysctl_wunlock();
370 sx_xlock(&kld_sx);
371 }
372
373 static void
linker_file_unregister_sysctls(linker_file_t lf)374 linker_file_unregister_sysctls(linker_file_t lf)
375 {
376 struct sysctl_oid **start, **stop, **oidp;
377
378 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
379 " for %s\n", lf->filename));
380
381 sx_assert(&kld_sx, SA_XLOCKED);
382
383 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
384 return;
385
386 sx_xunlock(&kld_sx);
387 sysctl_wlock();
388 for (oidp = start; oidp < stop; oidp++)
389 sysctl_unregister_oid(*oidp);
390 sysctl_wunlock();
391 sx_xlock(&kld_sx);
392 }
393
394 static int
linker_file_register_modules(linker_file_t lf)395 linker_file_register_modules(linker_file_t lf)
396 {
397 struct mod_metadata **start, **stop, **mdp;
398 const moduledata_t *moddata;
399 int first_error, error;
400
401 KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
402 " in %s\n", lf->filename));
403
404 sx_assert(&kld_sx, SA_XLOCKED);
405
406 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL) != 0) {
407 /*
408 * This fallback should be unnecessary, but if we get booted
409 * from boot2 instead of loader and we are missing our
410 * metadata then we have to try the best we can.
411 */
412 if (lf == linker_kernel_file) {
413 start = SET_BEGIN(modmetadata_set);
414 stop = SET_LIMIT(modmetadata_set);
415 } else
416 return (0);
417 }
418 first_error = 0;
419 for (mdp = start; mdp < stop; mdp++) {
420 if ((*mdp)->md_type != MDT_MODULE)
421 continue;
422 moddata = (*mdp)->md_data;
423 KLD_DPF(FILE, ("Registering module %s in %s\n",
424 moddata->name, lf->filename));
425 error = module_register(moddata, lf);
426 if (error) {
427 printf("Module %s failed to register: %d\n",
428 moddata->name, error);
429 if (first_error == 0)
430 first_error = error;
431 }
432 }
433 return (first_error);
434 }
435
436 static void
linker_init_kernel_modules(void)437 linker_init_kernel_modules(void)
438 {
439
440 sx_xlock(&kld_sx);
441 linker_file_register_modules(linker_kernel_file);
442 sx_xunlock(&kld_sx);
443 }
444
445 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
446 NULL);
447
448 static int
linker_load_file(const char * filename,linker_file_t * result)449 linker_load_file(const char *filename, linker_file_t *result)
450 {
451 linker_class_t lc;
452 linker_file_t lf;
453 int foundfile, error, modules;
454
455 /* Refuse to load modules if securelevel raised */
456 if (prison0.pr_securelevel > 0)
457 return (EPERM);
458
459 sx_assert(&kld_sx, SA_XLOCKED);
460 lf = linker_find_file_by_name(filename);
461 if (lf) {
462 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
463 " incrementing refs\n", filename));
464 *result = lf;
465 lf->refs++;
466 return (0);
467 }
468 foundfile = 0;
469 error = 0;
470
471 /*
472 * We do not need to protect (lock) classes here because there is
473 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
474 * and there is no class deregistration mechanism at this time.
475 */
476 TAILQ_FOREACH(lc, &classes, link) {
477 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
478 filename));
479 error = LINKER_LOAD_FILE(lc, filename, &lf);
480 /*
481 * If we got something other than ENOENT, then it exists but
482 * we cannot load it for some other reason.
483 */
484 if (error != ENOENT) {
485 foundfile = 1;
486 if (error == EEXIST)
487 break;
488 }
489 if (lf) {
490 error = linker_file_register_modules(lf);
491 if (error == EEXIST) {
492 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
493 return (error);
494 }
495 modules = !TAILQ_EMPTY(&lf->modules);
496 linker_file_register_sysctls(lf, false);
497 #ifdef VIMAGE
498 LINKER_PROPAGATE_VNETS(lf);
499 #endif
500 linker_file_sysinit(lf);
501 lf->flags |= LINKER_FILE_LINKED;
502
503 /*
504 * If all of the modules in this file failed
505 * to load, unload the file and return an
506 * error of ENOEXEC.
507 */
508 if (modules && TAILQ_EMPTY(&lf->modules)) {
509 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
510 return (ENOEXEC);
511 }
512 linker_file_enable_sysctls(lf);
513
514 /*
515 * Ask the linker to load CTF data for this file.
516 */
517 linker_ctf_load_file(lf);
518 EVENTHANDLER_INVOKE(kld_load, lf);
519 *result = lf;
520 return (0);
521 }
522 }
523 /*
524 * Less than ideal, but tells the user whether it failed to load or
525 * the module was not found.
526 */
527 if (foundfile) {
528 /*
529 * If the file type has not been recognized by the last try
530 * printout a message before to fail.
531 */
532 if (error == ENOSYS)
533 printf("%s: %s - unsupported file type\n",
534 __func__, filename);
535
536 /*
537 * Format not recognized or otherwise unloadable.
538 * When loading a module that is statically built into
539 * the kernel EEXIST percolates back up as the return
540 * value. Preserve this so that apps like sysinstall
541 * can recognize this special case and not post bogus
542 * dialog boxes.
543 */
544 if (error != EEXIST)
545 error = ENOEXEC;
546 } else
547 error = ENOENT; /* Nothing found */
548 return (error);
549 }
550
551 int
linker_reference_module(const char * modname,struct mod_depend * verinfo,linker_file_t * result)552 linker_reference_module(const char *modname, struct mod_depend *verinfo,
553 linker_file_t *result)
554 {
555 modlist_t mod;
556 int error;
557
558 sx_xlock(&kld_sx);
559 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
560 *result = mod->container;
561 (*result)->refs++;
562 sx_xunlock(&kld_sx);
563 return (0);
564 }
565
566 error = linker_load_module(NULL, modname, NULL, verinfo, result);
567 sx_xunlock(&kld_sx);
568 return (error);
569 }
570
571 int
linker_release_module(const char * modname,struct mod_depend * verinfo,linker_file_t lf)572 linker_release_module(const char *modname, struct mod_depend *verinfo,
573 linker_file_t lf)
574 {
575 modlist_t mod;
576 int error;
577
578 sx_xlock(&kld_sx);
579 if (lf == NULL) {
580 KASSERT(modname != NULL,
581 ("linker_release_module: no file or name"));
582 mod = modlist_lookup2(modname, verinfo);
583 if (mod == NULL) {
584 sx_xunlock(&kld_sx);
585 return (ESRCH);
586 }
587 lf = mod->container;
588 } else
589 KASSERT(modname == NULL && verinfo == NULL,
590 ("linker_release_module: both file and name"));
591 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
592 sx_xunlock(&kld_sx);
593 return (error);
594 }
595
596 static linker_file_t
linker_find_file_by_name(const char * filename)597 linker_find_file_by_name(const char *filename)
598 {
599 linker_file_t lf;
600 char *koname;
601
602 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
603 sprintf(koname, "%s.ko", filename);
604
605 sx_assert(&kld_sx, SA_XLOCKED);
606 TAILQ_FOREACH(lf, &linker_files, link) {
607 if (strcmp(lf->filename, koname) == 0)
608 break;
609 if (strcmp(lf->filename, filename) == 0)
610 break;
611 }
612 free(koname, M_LINKER);
613 return (lf);
614 }
615
616 static linker_file_t
linker_find_file_by_id(int fileid)617 linker_find_file_by_id(int fileid)
618 {
619 linker_file_t lf;
620
621 sx_assert(&kld_sx, SA_XLOCKED);
622 TAILQ_FOREACH(lf, &linker_files, link)
623 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
624 break;
625 return (lf);
626 }
627
628 int
linker_file_foreach(linker_predicate_t * predicate,void * context)629 linker_file_foreach(linker_predicate_t *predicate, void *context)
630 {
631 linker_file_t lf;
632 int retval = 0;
633
634 sx_xlock(&kld_sx);
635 TAILQ_FOREACH(lf, &linker_files, link) {
636 retval = predicate(lf, context);
637 if (retval != 0)
638 break;
639 }
640 sx_xunlock(&kld_sx);
641 return (retval);
642 }
643
644 linker_file_t
linker_make_file(const char * pathname,linker_class_t lc)645 linker_make_file(const char *pathname, linker_class_t lc)
646 {
647 linker_file_t lf;
648 const char *filename;
649
650 if (!cold)
651 sx_assert(&kld_sx, SA_XLOCKED);
652 filename = linker_basename(pathname);
653
654 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
655 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
656 if (lf == NULL)
657 return (NULL);
658 lf->ctors_addr = 0;
659 lf->ctors_size = 0;
660 lf->ctors_invoked = LF_NONE;
661 lf->dtors_addr = 0;
662 lf->dtors_size = 0;
663 lf->refs = 1;
664 lf->userrefs = 0;
665 lf->flags = 0;
666 lf->filename = strdup(filename, M_LINKER);
667 lf->pathname = strdup(pathname, M_LINKER);
668 LINKER_GET_NEXT_FILE_ID(lf->id);
669 lf->ndeps = 0;
670 lf->deps = NULL;
671 lf->loadcnt = ++loadcnt;
672 #ifdef __arm__
673 lf->exidx_addr = 0;
674 lf->exidx_size = 0;
675 #endif
676 STAILQ_INIT(&lf->common);
677 TAILQ_INIT(&lf->modules);
678 TAILQ_INSERT_TAIL(&linker_files, lf, link);
679 return (lf);
680 }
681
682 int
linker_file_unload(linker_file_t file,int flags)683 linker_file_unload(linker_file_t file, int flags)
684 {
685 module_t mod, next;
686 modlist_t ml, nextml;
687 struct common_symbol *cp;
688 int error, i;
689
690 /* Refuse to unload modules if securelevel raised. */
691 if (prison0.pr_securelevel > 0)
692 return (EPERM);
693
694 sx_assert(&kld_sx, SA_XLOCKED);
695 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
696
697 /* Easy case of just dropping a reference. */
698 if (file->refs > 1) {
699 file->refs--;
700 return (0);
701 }
702
703 /* Give eventhandlers a chance to prevent the unload. */
704 error = 0;
705 EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
706 if (error != 0)
707 return (EBUSY);
708
709 KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
710 " informing modules\n"));
711
712 /*
713 * Quiesce all the modules to give them a chance to veto the unload.
714 */
715 MOD_SLOCK;
716 for (mod = TAILQ_FIRST(&file->modules); mod;
717 mod = module_getfnext(mod)) {
718 error = module_quiesce(mod);
719 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
720 KLD_DPF(FILE, ("linker_file_unload: module %s"
721 " vetoed unload\n", module_getname(mod)));
722 /*
723 * XXX: Do we need to tell all the quiesced modules
724 * that they can resume work now via a new module
725 * event?
726 */
727 MOD_SUNLOCK;
728 return (error);
729 }
730 }
731 MOD_SUNLOCK;
732
733 /*
734 * Inform any modules associated with this file that they are
735 * being unloaded.
736 */
737 MOD_XLOCK;
738 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
739 next = module_getfnext(mod);
740 MOD_XUNLOCK;
741
742 /*
743 * Give the module a chance to veto the unload.
744 */
745 if ((error = module_unload(mod)) != 0) {
746 #ifdef KLD_DEBUG
747 MOD_SLOCK;
748 KLD_DPF(FILE, ("linker_file_unload: module %s"
749 " failed unload\n", module_getname(mod)));
750 MOD_SUNLOCK;
751 #endif
752 return (error);
753 }
754 MOD_XLOCK;
755 module_release(mod);
756 }
757 MOD_XUNLOCK;
758
759 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
760 if (ml->container == file) {
761 TAILQ_REMOVE(&found_modules, ml, link);
762 free(ml, M_LINKER);
763 }
764 }
765
766 /*
767 * Don't try to run SYSUNINITs if we are unloaded due to a
768 * link error.
769 */
770 if (file->flags & LINKER_FILE_LINKED) {
771 file->flags &= ~LINKER_FILE_LINKED;
772 linker_file_unregister_sysctls(file);
773 linker_file_sysuninit(file);
774 }
775 TAILQ_REMOVE(&linker_files, file, link);
776
777 if (file->deps) {
778 for (i = 0; i < file->ndeps; i++)
779 linker_file_unload(file->deps[i], flags);
780 free(file->deps, M_LINKER);
781 file->deps = NULL;
782 }
783 while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
784 STAILQ_REMOVE_HEAD(&file->common, link);
785 free(cp, M_LINKER);
786 }
787
788 LINKER_UNLOAD(file);
789
790 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
791 file->size);
792
793 if (file->filename) {
794 free(file->filename, M_LINKER);
795 file->filename = NULL;
796 }
797 if (file->pathname) {
798 free(file->pathname, M_LINKER);
799 file->pathname = NULL;
800 }
801 kobj_delete((kobj_t) file, M_LINKER);
802 return (0);
803 }
804
805 int
linker_ctf_get(linker_file_t file,linker_ctf_t * lc)806 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
807 {
808 return (LINKER_CTF_GET(file, lc));
809 }
810
811 int
linker_ctf_lookup_typename_ddb(linker_ctf_t * lc,const char * typename)812 linker_ctf_lookup_typename_ddb(linker_ctf_t *lc, const char *typename)
813 {
814 #ifdef DDB
815 linker_file_t lf;
816
817 TAILQ_FOREACH (lf, &linker_files, link){
818 if (LINKER_CTF_LOOKUP_TYPENAME(lf, lc, typename) == 0)
819 return (0);
820 }
821 #endif
822 return (ENOENT);
823 }
824
825 int
linker_ctf_lookup_sym_ddb(const char * symname,c_linker_sym_t * sym,linker_ctf_t * lc)826 linker_ctf_lookup_sym_ddb(const char *symname, c_linker_sym_t *sym,
827 linker_ctf_t *lc)
828 {
829 #ifdef DDB
830 linker_file_t lf;
831
832 TAILQ_FOREACH (lf, &linker_files, link){
833 if (LINKER_LOOKUP_DEBUG_SYMBOL_CTF(lf, symname, sym, lc) == 0)
834 return (0);
835 }
836 #endif
837 return (ENOENT);
838 }
839
840 static void
linker_file_add_dependency(linker_file_t file,linker_file_t dep)841 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
842 {
843 linker_file_t *newdeps;
844
845 sx_assert(&kld_sx, SA_XLOCKED);
846 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
847 M_LINKER, M_WAITOK | M_ZERO);
848 file->deps[file->ndeps] = dep;
849 file->ndeps++;
850 KLD_DPF(FILE, ("linker_file_add_dependency:"
851 " adding %s as dependency for %s\n",
852 dep->filename, file->filename));
853 }
854
855 /*
856 * Locate a linker set and its contents. This is a helper function to avoid
857 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **.
858 * This function is used in this file so we can avoid having lots of (void **)
859 * casts.
860 */
861 int
linker_file_lookup_set(linker_file_t file,const char * name,void * firstp,void * lastp,int * countp)862 linker_file_lookup_set(linker_file_t file, const char *name,
863 void *firstp, void *lastp, int *countp)
864 {
865
866 sx_assert(&kld_sx, SA_LOCKED);
867 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
868 }
869
870 /*
871 * List all functions in a file.
872 */
873 int
linker_file_function_listall(linker_file_t lf,linker_function_nameval_callback_t callback_func,void * arg)874 linker_file_function_listall(linker_file_t lf,
875 linker_function_nameval_callback_t callback_func, void *arg)
876 {
877 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
878 }
879
880 caddr_t
linker_file_lookup_symbol(linker_file_t file,const char * name,int deps)881 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
882 {
883 caddr_t sym;
884 int locked;
885
886 locked = sx_xlocked(&kld_sx);
887 if (!locked)
888 sx_xlock(&kld_sx);
889 sym = linker_file_lookup_symbol_internal(file, name, deps);
890 if (!locked)
891 sx_xunlock(&kld_sx);
892 return (sym);
893 }
894
895 static caddr_t
linker_file_lookup_symbol_internal(linker_file_t file,const char * name,int deps)896 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
897 int deps)
898 {
899 c_linker_sym_t sym;
900 linker_symval_t symval;
901 caddr_t address;
902 size_t common_size = 0;
903 int i;
904
905 sx_assert(&kld_sx, SA_XLOCKED);
906 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
907 file, name, deps));
908
909 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
910 LINKER_SYMBOL_VALUES(file, sym, &symval);
911 if (symval.value == 0)
912 /*
913 * For commons, first look them up in the
914 * dependencies and only allocate space if not found
915 * there.
916 */
917 common_size = symval.size;
918 else {
919 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
920 ".value=%p\n", symval.value));
921 return (symval.value);
922 }
923 }
924 if (deps) {
925 for (i = 0; i < file->ndeps; i++) {
926 address = linker_file_lookup_symbol_internal(
927 file->deps[i], name, 0);
928 if (address) {
929 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
930 " deps value=%p\n", address));
931 return (address);
932 }
933 }
934 }
935 if (common_size > 0) {
936 /*
937 * This is a common symbol which was not found in the
938 * dependencies. We maintain a simple common symbol table in
939 * the file object.
940 */
941 struct common_symbol *cp;
942
943 STAILQ_FOREACH(cp, &file->common, link) {
944 if (strcmp(cp->name, name) == 0) {
945 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
946 " old common value=%p\n", cp->address));
947 return (cp->address);
948 }
949 }
950 /*
951 * Round the symbol size up to align.
952 */
953 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
954 cp = malloc(sizeof(struct common_symbol)
955 + common_size + strlen(name) + 1, M_LINKER,
956 M_WAITOK | M_ZERO);
957 cp->address = (caddr_t)(cp + 1);
958 cp->name = cp->address + common_size;
959 strcpy(cp->name, name);
960 bzero(cp->address, common_size);
961 STAILQ_INSERT_TAIL(&file->common, cp, link);
962
963 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
964 " value=%p\n", cp->address));
965 return (cp->address);
966 }
967 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
968 return (0);
969 }
970
971 /*
972 * Both DDB and stack(9) rely on the kernel linker to provide forward and
973 * backward lookup of symbols. However, DDB and sometimes stack(9) need to
974 * do this in a lockfree manner. We provide a set of internal helper
975 * routines to perform these operations without locks, and then wrappers that
976 * optionally lock.
977 *
978 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
979 */
980 #ifdef DDB
981 static int
linker_debug_lookup(const char * symstr,c_linker_sym_t * sym)982 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
983 {
984 linker_file_t lf;
985
986 TAILQ_FOREACH(lf, &linker_files, link) {
987 if (LINKER_LOOKUP_DEBUG_SYMBOL(lf, symstr, sym) == 0)
988 return (0);
989 }
990 return (ENOENT);
991 }
992 #endif
993
994 static int
linker_debug_search_symbol(caddr_t value,c_linker_sym_t * sym,long * diffp)995 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
996 {
997 linker_file_t lf;
998 c_linker_sym_t best, es;
999 u_long diff, bestdiff, off;
1000
1001 best = 0;
1002 off = (uintptr_t)value;
1003 bestdiff = off;
1004 TAILQ_FOREACH(lf, &linker_files, link) {
1005 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
1006 continue;
1007 if (es != 0 && diff < bestdiff) {
1008 best = es;
1009 bestdiff = diff;
1010 }
1011 if (bestdiff == 0)
1012 break;
1013 }
1014 if (best) {
1015 *sym = best;
1016 *diffp = bestdiff;
1017 return (0);
1018 } else {
1019 *sym = 0;
1020 *diffp = off;
1021 return (ENOENT);
1022 }
1023 }
1024
1025 static int
linker_debug_symbol_values(c_linker_sym_t sym,linker_symval_t * symval)1026 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
1027 {
1028 linker_file_t lf;
1029
1030 TAILQ_FOREACH(lf, &linker_files, link) {
1031 if (LINKER_DEBUG_SYMBOL_VALUES(lf, sym, symval) == 0)
1032 return (0);
1033 }
1034 return (ENOENT);
1035 }
1036
1037 static int
linker_debug_search_symbol_name(caddr_t value,char * buf,u_int buflen,long * offset)1038 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
1039 long *offset)
1040 {
1041 linker_symval_t symval;
1042 c_linker_sym_t sym;
1043 int error;
1044
1045 *offset = 0;
1046 error = linker_debug_search_symbol(value, &sym, offset);
1047 if (error)
1048 return (error);
1049 error = linker_debug_symbol_values(sym, &symval);
1050 if (error)
1051 return (error);
1052 strlcpy(buf, symval.name, buflen);
1053 return (0);
1054 }
1055
1056 /*
1057 * DDB Helpers. DDB has to look across multiple files with their own symbol
1058 * tables and string tables.
1059 *
1060 * Note that we do not obey list locking protocols here. We really don't need
1061 * DDB to hang because somebody's got the lock held. We'll take the chance
1062 * that the files list is inconsistent instead.
1063 */
1064 #ifdef DDB
1065 int
linker_ddb_lookup(const char * symstr,c_linker_sym_t * sym)1066 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
1067 {
1068
1069 return (linker_debug_lookup(symstr, sym));
1070 }
1071 #endif
1072
1073 int
linker_ddb_search_symbol(caddr_t value,c_linker_sym_t * sym,long * diffp)1074 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
1075 {
1076
1077 return (linker_debug_search_symbol(value, sym, diffp));
1078 }
1079
1080 int
linker_ddb_symbol_values(c_linker_sym_t sym,linker_symval_t * symval)1081 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
1082 {
1083
1084 return (linker_debug_symbol_values(sym, symval));
1085 }
1086
1087 int
linker_ddb_search_symbol_name(caddr_t value,char * buf,u_int buflen,long * offset)1088 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
1089 long *offset)
1090 {
1091
1092 return (linker_debug_search_symbol_name(value, buf, buflen, offset));
1093 }
1094
1095 /*
1096 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do
1097 * obey locking protocols, and offer a significantly less complex interface.
1098 */
1099 int
linker_search_symbol_name_flags(caddr_t value,char * buf,u_int buflen,long * offset,int flags)1100 linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen,
1101 long *offset, int flags)
1102 {
1103 int error;
1104
1105 KASSERT((flags & (M_NOWAIT | M_WAITOK)) != 0 &&
1106 (flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
1107 ("%s: bad flags: 0x%x", __func__, flags));
1108
1109 if (flags & M_NOWAIT) {
1110 if (!sx_try_slock(&kld_sx))
1111 return (EWOULDBLOCK);
1112 } else
1113 sx_slock(&kld_sx);
1114
1115 error = linker_debug_search_symbol_name(value, buf, buflen, offset);
1116 sx_sunlock(&kld_sx);
1117 return (error);
1118 }
1119
1120 int
linker_search_symbol_name(caddr_t value,char * buf,u_int buflen,long * offset)1121 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
1122 long *offset)
1123 {
1124
1125 return (linker_search_symbol_name_flags(value, buf, buflen, offset,
1126 M_WAITOK));
1127 }
1128
1129 int
linker_kldload_busy(int flags)1130 linker_kldload_busy(int flags)
1131 {
1132 int error;
1133
1134 MPASS((flags & ~(LINKER_UB_UNLOCK | LINKER_UB_LOCKED |
1135 LINKER_UB_PCATCH)) == 0);
1136 if ((flags & LINKER_UB_LOCKED) != 0)
1137 sx_assert(&kld_sx, SA_XLOCKED);
1138
1139 if ((flags & LINKER_UB_LOCKED) == 0)
1140 sx_xlock(&kld_sx);
1141 while (kld_busy > 0) {
1142 if (kld_busy_owner == curthread)
1143 break;
1144 error = sx_sleep(&kld_busy, &kld_sx,
1145 (flags & LINKER_UB_PCATCH) != 0 ? PCATCH : 0,
1146 "kldbusy", 0);
1147 if (error != 0) {
1148 if ((flags & LINKER_UB_UNLOCK) != 0)
1149 sx_xunlock(&kld_sx);
1150 return (error);
1151 }
1152 }
1153 kld_busy++;
1154 kld_busy_owner = curthread;
1155 if ((flags & LINKER_UB_UNLOCK) != 0)
1156 sx_xunlock(&kld_sx);
1157 return (0);
1158 }
1159
1160 void
linker_kldload_unbusy(int flags)1161 linker_kldload_unbusy(int flags)
1162 {
1163 MPASS((flags & ~LINKER_UB_LOCKED) == 0);
1164 if ((flags & LINKER_UB_LOCKED) != 0)
1165 sx_assert(&kld_sx, SA_XLOCKED);
1166
1167 if ((flags & LINKER_UB_LOCKED) == 0)
1168 sx_xlock(&kld_sx);
1169 MPASS(kld_busy > 0);
1170 if (kld_busy_owner != curthread)
1171 panic("linker_kldload_unbusy done by not owning thread %p",
1172 kld_busy_owner);
1173 kld_busy--;
1174 if (kld_busy == 0) {
1175 kld_busy_owner = NULL;
1176 wakeup(&kld_busy);
1177 }
1178 sx_xunlock(&kld_sx);
1179 }
1180
1181 /*
1182 * Syscalls.
1183 */
1184 int
kern_kldload(struct thread * td,const char * file,int * fileid)1185 kern_kldload(struct thread *td, const char *file, int *fileid)
1186 {
1187 const char *kldname, *modname;
1188 linker_file_t lf;
1189 int error;
1190
1191 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1192 return (error);
1193
1194 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
1195 return (error);
1196
1197 /*
1198 * If file does not contain a qualified name or any dot in it
1199 * (kldname.ko, or kldname.ver.ko) treat it as an interface
1200 * name.
1201 */
1202 if (strchr(file, '/') || strchr(file, '.')) {
1203 kldname = file;
1204 modname = NULL;
1205 } else {
1206 kldname = NULL;
1207 modname = file;
1208 }
1209
1210 error = linker_kldload_busy(LINKER_UB_PCATCH);
1211 if (error != 0) {
1212 sx_xunlock(&kld_sx);
1213 return (error);
1214 }
1215
1216 /*
1217 * It is possible that kldloaded module will attach a new ifnet,
1218 * so vnet context must be set when this ocurs.
1219 */
1220 CURVNET_SET(TD_TO_VNET(td));
1221
1222 error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1223 CURVNET_RESTORE();
1224
1225 if (error == 0) {
1226 lf->userrefs++;
1227 if (fileid != NULL)
1228 *fileid = lf->id;
1229 }
1230 linker_kldload_unbusy(LINKER_UB_LOCKED);
1231 return (error);
1232 }
1233
1234 int
sys_kldload(struct thread * td,struct kldload_args * uap)1235 sys_kldload(struct thread *td, struct kldload_args *uap)
1236 {
1237 char *pathname = NULL;
1238 int error, fileid;
1239
1240 td->td_retval[0] = -1;
1241
1242 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1243 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1244 if (error == 0) {
1245 error = kern_kldload(td, pathname, &fileid);
1246 if (error == 0)
1247 td->td_retval[0] = fileid;
1248 }
1249 free(pathname, M_TEMP);
1250 return (error);
1251 }
1252
1253 int
kern_kldunload(struct thread * td,int fileid,int flags)1254 kern_kldunload(struct thread *td, int fileid, int flags)
1255 {
1256 linker_file_t lf;
1257 int error = 0;
1258
1259 if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1260 return (error);
1261
1262 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1263 return (error);
1264
1265 error = linker_kldload_busy(LINKER_UB_PCATCH);
1266 if (error != 0) {
1267 sx_xunlock(&kld_sx);
1268 return (error);
1269 }
1270
1271 CURVNET_SET(TD_TO_VNET(td));
1272 lf = linker_find_file_by_id(fileid);
1273 if (lf) {
1274 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1275
1276 if (lf->userrefs == 0) {
1277 /*
1278 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1279 */
1280 printf("kldunload: attempt to unload file that was"
1281 " loaded by the kernel\n");
1282 error = EBUSY;
1283 } else if (lf->refs > 1) {
1284 error = EBUSY;
1285 } else {
1286 lf->userrefs--;
1287 error = linker_file_unload(lf, flags);
1288 if (error)
1289 lf->userrefs++;
1290 }
1291 } else
1292 error = ENOENT;
1293 CURVNET_RESTORE();
1294 linker_kldload_unbusy(LINKER_UB_LOCKED);
1295 return (error);
1296 }
1297
1298 int
sys_kldunload(struct thread * td,struct kldunload_args * uap)1299 sys_kldunload(struct thread *td, struct kldunload_args *uap)
1300 {
1301
1302 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1303 }
1304
1305 int
sys_kldunloadf(struct thread * td,struct kldunloadf_args * uap)1306 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1307 {
1308
1309 if (uap->flags != LINKER_UNLOAD_NORMAL &&
1310 uap->flags != LINKER_UNLOAD_FORCE)
1311 return (EINVAL);
1312 return (kern_kldunload(td, uap->fileid, uap->flags));
1313 }
1314
1315 int
sys_kldfind(struct thread * td,struct kldfind_args * uap)1316 sys_kldfind(struct thread *td, struct kldfind_args *uap)
1317 {
1318 char *pathname;
1319 const char *filename;
1320 linker_file_t lf;
1321 int error;
1322
1323 #ifdef MAC
1324 error = mac_kld_check_stat(td->td_ucred);
1325 if (error)
1326 return (error);
1327 #endif
1328
1329 td->td_retval[0] = -1;
1330
1331 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1332 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1333 goto out;
1334
1335 filename = linker_basename(pathname);
1336 sx_xlock(&kld_sx);
1337 lf = linker_find_file_by_name(filename);
1338 if (lf)
1339 td->td_retval[0] = lf->id;
1340 else
1341 error = ENOENT;
1342 sx_xunlock(&kld_sx);
1343 out:
1344 free(pathname, M_TEMP);
1345 return (error);
1346 }
1347
1348 int
sys_kldnext(struct thread * td,struct kldnext_args * uap)1349 sys_kldnext(struct thread *td, struct kldnext_args *uap)
1350 {
1351 linker_file_t lf;
1352 int error = 0;
1353
1354 #ifdef MAC
1355 error = mac_kld_check_stat(td->td_ucred);
1356 if (error)
1357 return (error);
1358 #endif
1359
1360 sx_xlock(&kld_sx);
1361 if (uap->fileid == 0)
1362 lf = TAILQ_FIRST(&linker_files);
1363 else {
1364 lf = linker_find_file_by_id(uap->fileid);
1365 if (lf == NULL) {
1366 error = ENOENT;
1367 goto out;
1368 }
1369 lf = TAILQ_NEXT(lf, link);
1370 }
1371
1372 /* Skip partially loaded files. */
1373 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1374 lf = TAILQ_NEXT(lf, link);
1375
1376 if (lf)
1377 td->td_retval[0] = lf->id;
1378 else
1379 td->td_retval[0] = 0;
1380 out:
1381 sx_xunlock(&kld_sx);
1382 return (error);
1383 }
1384
1385 int
sys_kldstat(struct thread * td,struct kldstat_args * uap)1386 sys_kldstat(struct thread *td, struct kldstat_args *uap)
1387 {
1388 struct kld_file_stat *stat;
1389 int error, version;
1390
1391 /*
1392 * Check the version of the user's structure.
1393 */
1394 if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
1395 != 0)
1396 return (error);
1397 if (version != sizeof(struct kld_file_stat_1) &&
1398 version != sizeof(struct kld_file_stat))
1399 return (EINVAL);
1400
1401 stat = malloc(sizeof(*stat), M_TEMP, M_WAITOK | M_ZERO);
1402 error = kern_kldstat(td, uap->fileid, stat);
1403 if (error == 0)
1404 error = copyout(stat, uap->stat, version);
1405 free(stat, M_TEMP);
1406 return (error);
1407 }
1408
1409 int
kern_kldstat(struct thread * td,int fileid,struct kld_file_stat * stat)1410 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
1411 {
1412 linker_file_t lf;
1413 int namelen;
1414 #ifdef MAC
1415 int error;
1416
1417 error = mac_kld_check_stat(td->td_ucred);
1418 if (error)
1419 return (error);
1420 #endif
1421
1422 sx_xlock(&kld_sx);
1423 lf = linker_find_file_by_id(fileid);
1424 if (lf == NULL) {
1425 sx_xunlock(&kld_sx);
1426 return (ENOENT);
1427 }
1428
1429 /* Version 1 fields: */
1430 namelen = strlen(lf->filename) + 1;
1431 if (namelen > sizeof(stat->name))
1432 namelen = sizeof(stat->name);
1433 bcopy(lf->filename, &stat->name[0], namelen);
1434 stat->refs = lf->refs;
1435 stat->id = lf->id;
1436 stat->address = lf->address;
1437 stat->size = lf->size;
1438 /* Version 2 fields: */
1439 namelen = strlen(lf->pathname) + 1;
1440 if (namelen > sizeof(stat->pathname))
1441 namelen = sizeof(stat->pathname);
1442 bcopy(lf->pathname, &stat->pathname[0], namelen);
1443 sx_xunlock(&kld_sx);
1444
1445 td->td_retval[0] = 0;
1446 return (0);
1447 }
1448
1449 #ifdef DDB
DB_COMMAND_FLAGS(kldstat,db_kldstat,DB_CMD_MEMSAFE)1450 DB_COMMAND_FLAGS(kldstat, db_kldstat, DB_CMD_MEMSAFE)
1451 {
1452 linker_file_t lf;
1453
1454 #define POINTER_WIDTH ((int)(sizeof(void *) * 2 + 2))
1455 db_printf("Id Refs Address%*c Size Name\n", POINTER_WIDTH - 7, ' ');
1456 #undef POINTER_WIDTH
1457 TAILQ_FOREACH(lf, &linker_files, link) {
1458 if (db_pager_quit)
1459 return;
1460 db_printf("%2d %4d %p %-8zx %s\n", lf->id, lf->refs,
1461 lf->address, lf->size, lf->filename);
1462 }
1463 }
1464 #endif /* DDB */
1465
1466 int
sys_kldfirstmod(struct thread * td,struct kldfirstmod_args * uap)1467 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1468 {
1469 linker_file_t lf;
1470 module_t mp;
1471 int error = 0;
1472
1473 #ifdef MAC
1474 error = mac_kld_check_stat(td->td_ucred);
1475 if (error)
1476 return (error);
1477 #endif
1478
1479 sx_xlock(&kld_sx);
1480 lf = linker_find_file_by_id(uap->fileid);
1481 if (lf) {
1482 MOD_SLOCK;
1483 mp = TAILQ_FIRST(&lf->modules);
1484 if (mp != NULL)
1485 td->td_retval[0] = module_getid(mp);
1486 else
1487 td->td_retval[0] = 0;
1488 MOD_SUNLOCK;
1489 } else
1490 error = ENOENT;
1491 sx_xunlock(&kld_sx);
1492 return (error);
1493 }
1494
1495 int
sys_kldsym(struct thread * td,struct kldsym_args * uap)1496 sys_kldsym(struct thread *td, struct kldsym_args *uap)
1497 {
1498 char *symstr = NULL;
1499 c_linker_sym_t sym;
1500 linker_symval_t symval;
1501 linker_file_t lf;
1502 struct kld_sym_lookup lookup;
1503 int error = 0;
1504
1505 #ifdef MAC
1506 error = mac_kld_check_stat(td->td_ucred);
1507 if (error)
1508 return (error);
1509 #endif
1510
1511 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1512 return (error);
1513 if (lookup.version != sizeof(lookup) ||
1514 uap->cmd != KLDSYM_LOOKUP)
1515 return (EINVAL);
1516 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1517 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1518 goto out;
1519 sx_xlock(&kld_sx);
1520 if (uap->fileid != 0) {
1521 lf = linker_find_file_by_id(uap->fileid);
1522 if (lf == NULL)
1523 error = ENOENT;
1524 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1525 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1526 lookup.symvalue = (uintptr_t) symval.value;
1527 lookup.symsize = symval.size;
1528 error = copyout(&lookup, uap->data, sizeof(lookup));
1529 } else
1530 error = ENOENT;
1531 } else {
1532 TAILQ_FOREACH(lf, &linker_files, link) {
1533 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1534 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1535 lookup.symvalue = (uintptr_t)symval.value;
1536 lookup.symsize = symval.size;
1537 error = copyout(&lookup, uap->data,
1538 sizeof(lookup));
1539 break;
1540 }
1541 }
1542 if (lf == NULL)
1543 error = ENOENT;
1544 }
1545 sx_xunlock(&kld_sx);
1546 out:
1547 free(symstr, M_TEMP);
1548 return (error);
1549 }
1550
1551 /*
1552 * Preloaded module support
1553 */
1554
1555 static modlist_t
modlist_lookup(const char * name,int ver)1556 modlist_lookup(const char *name, int ver)
1557 {
1558 modlist_t mod;
1559
1560 TAILQ_FOREACH(mod, &found_modules, link) {
1561 if (strcmp(mod->name, name) == 0 &&
1562 (ver == 0 || mod->version == ver))
1563 return (mod);
1564 }
1565 return (NULL);
1566 }
1567
1568 static modlist_t
modlist_lookup2(const char * name,const struct mod_depend * verinfo)1569 modlist_lookup2(const char *name, const struct mod_depend *verinfo)
1570 {
1571 modlist_t mod, bestmod;
1572 int ver;
1573
1574 if (verinfo == NULL)
1575 return (modlist_lookup(name, 0));
1576 bestmod = NULL;
1577 TAILQ_FOREACH(mod, &found_modules, link) {
1578 if (strcmp(mod->name, name) != 0)
1579 continue;
1580 ver = mod->version;
1581 if (ver == verinfo->md_ver_preferred)
1582 return (mod);
1583 if (ver >= verinfo->md_ver_minimum &&
1584 ver <= verinfo->md_ver_maximum &&
1585 (bestmod == NULL || ver > bestmod->version))
1586 bestmod = mod;
1587 }
1588 return (bestmod);
1589 }
1590
1591 static modlist_t
modlist_newmodule(const char * modname,int version,linker_file_t container)1592 modlist_newmodule(const char *modname, int version, linker_file_t container)
1593 {
1594 modlist_t mod;
1595
1596 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1597 if (mod == NULL)
1598 panic("no memory for module list");
1599 mod->container = container;
1600 mod->name = modname;
1601 mod->version = version;
1602 TAILQ_INSERT_TAIL(&found_modules, mod, link);
1603 return (mod);
1604 }
1605
1606 static void
linker_addmodules(linker_file_t lf,struct mod_metadata ** start,struct mod_metadata ** stop,int preload)1607 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1608 struct mod_metadata **stop, int preload)
1609 {
1610 struct mod_metadata *mp, **mdp;
1611 const char *modname;
1612 int ver;
1613
1614 for (mdp = start; mdp < stop; mdp++) {
1615 mp = *mdp;
1616 if (mp->md_type != MDT_VERSION)
1617 continue;
1618 modname = mp->md_cval;
1619 ver = ((const struct mod_version *)mp->md_data)->mv_version;
1620 if (modlist_lookup(modname, ver) != NULL) {
1621 printf("module %s already present!\n", modname);
1622 /* XXX what can we do? this is a build error. :-( */
1623 continue;
1624 }
1625 modlist_newmodule(modname, ver, lf);
1626 }
1627 }
1628
1629 static void
linker_preload(void * arg)1630 linker_preload(void *arg)
1631 {
1632 caddr_t modptr;
1633 const char *modname, *nmodname;
1634 char *modtype;
1635 linker_file_t lf, nlf;
1636 linker_class_t lc;
1637 int error;
1638 linker_file_list_t loaded_files;
1639 linker_file_list_t depended_files;
1640 struct mod_metadata *mp, *nmp;
1641 struct mod_metadata **start, **stop, **mdp, **nmdp;
1642 const struct mod_depend *verinfo;
1643 int nver;
1644 int resolves;
1645 modlist_t mod;
1646 struct sysinit **si_start, **si_stop;
1647
1648 TAILQ_INIT(&loaded_files);
1649 TAILQ_INIT(&depended_files);
1650 TAILQ_INIT(&found_modules);
1651 error = 0;
1652
1653 modptr = NULL;
1654 sx_xlock(&kld_sx);
1655 while ((modptr = preload_search_next_name(modptr)) != NULL) {
1656 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1657 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1658 if (modname == NULL) {
1659 printf("Preloaded module at %p does not have a"
1660 " name!\n", modptr);
1661 continue;
1662 }
1663 if (modtype == NULL) {
1664 printf("Preloaded module at %p does not have a type!\n",
1665 modptr);
1666 continue;
1667 }
1668 if (bootverbose)
1669 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1670 modptr);
1671 lf = NULL;
1672 TAILQ_FOREACH(lc, &classes, link) {
1673 error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1674 if (!error)
1675 break;
1676 lf = NULL;
1677 }
1678 if (lf)
1679 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1680 }
1681
1682 /*
1683 * First get a list of stuff in the kernel.
1684 */
1685 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1686 &stop, NULL) == 0)
1687 linker_addmodules(linker_kernel_file, start, stop, 1);
1688
1689 /*
1690 * This is a once-off kinky bubble sort to resolve relocation
1691 * dependency requirements.
1692 */
1693 restart:
1694 TAILQ_FOREACH(lf, &loaded_files, loaded) {
1695 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1696 &stop, NULL);
1697 /*
1698 * First, look to see if we would successfully link with this
1699 * stuff.
1700 */
1701 resolves = 1; /* unless we know otherwise */
1702 if (!error) {
1703 for (mdp = start; mdp < stop; mdp++) {
1704 mp = *mdp;
1705 if (mp->md_type != MDT_DEPEND)
1706 continue;
1707 modname = mp->md_cval;
1708 verinfo = mp->md_data;
1709 for (nmdp = start; nmdp < stop; nmdp++) {
1710 nmp = *nmdp;
1711 if (nmp->md_type != MDT_VERSION)
1712 continue;
1713 nmodname = nmp->md_cval;
1714 if (strcmp(modname, nmodname) == 0)
1715 break;
1716 }
1717 if (nmdp < stop) /* it's a self reference */
1718 continue;
1719
1720 /*
1721 * ok, the module isn't here yet, we
1722 * are not finished
1723 */
1724 if (modlist_lookup2(modname, verinfo) == NULL)
1725 resolves = 0;
1726 }
1727 }
1728 /*
1729 * OK, if we found our modules, we can link. So, "provide"
1730 * the modules inside and add it to the end of the link order
1731 * list.
1732 */
1733 if (resolves) {
1734 if (!error) {
1735 for (mdp = start; mdp < stop; mdp++) {
1736 mp = *mdp;
1737 if (mp->md_type != MDT_VERSION)
1738 continue;
1739 modname = mp->md_cval;
1740 nver = ((const struct mod_version *)
1741 mp->md_data)->mv_version;
1742 if (modlist_lookup(modname,
1743 nver) != NULL) {
1744 printf("module %s already"
1745 " present!\n", modname);
1746 TAILQ_REMOVE(&loaded_files,
1747 lf, loaded);
1748 linker_file_unload(lf,
1749 LINKER_UNLOAD_FORCE);
1750 /* we changed tailq next ptr */
1751 goto restart;
1752 }
1753 modlist_newmodule(modname, nver, lf);
1754 }
1755 }
1756 TAILQ_REMOVE(&loaded_files, lf, loaded);
1757 TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1758 /*
1759 * Since we provided modules, we need to restart the
1760 * sort so that the previous files that depend on us
1761 * have a chance. Also, we've busted the tailq next
1762 * pointer with the REMOVE.
1763 */
1764 goto restart;
1765 }
1766 }
1767
1768 /*
1769 * At this point, we check to see what could not be resolved..
1770 */
1771 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1772 TAILQ_REMOVE(&loaded_files, lf, loaded);
1773 printf("KLD file %s is missing dependencies\n", lf->filename);
1774 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1775 }
1776
1777 /*
1778 * We made it. Finish off the linking in the order we determined.
1779 */
1780 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1781 if (linker_kernel_file) {
1782 linker_kernel_file->refs++;
1783 linker_file_add_dependency(lf, linker_kernel_file);
1784 }
1785 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1786 &stop, NULL);
1787 if (!error) {
1788 for (mdp = start; mdp < stop; mdp++) {
1789 mp = *mdp;
1790 if (mp->md_type != MDT_DEPEND)
1791 continue;
1792 modname = mp->md_cval;
1793 verinfo = mp->md_data;
1794 mod = modlist_lookup2(modname, verinfo);
1795 if (mod == NULL) {
1796 printf("KLD file %s - cannot find "
1797 "dependency \"%s\"\n",
1798 lf->filename, modname);
1799 goto fail;
1800 }
1801 /* Don't count self-dependencies */
1802 if (lf == mod->container)
1803 continue;
1804 mod->container->refs++;
1805 linker_file_add_dependency(lf, mod->container);
1806 }
1807 }
1808 /*
1809 * Now do relocation etc using the symbol search paths
1810 * established by the dependencies
1811 */
1812 error = LINKER_LINK_PRELOAD_FINISH(lf);
1813 if (error) {
1814 printf("KLD file %s - could not finalize loading\n",
1815 lf->filename);
1816 goto fail;
1817 }
1818 linker_file_register_modules(lf);
1819 if (!TAILQ_EMPTY(&lf->modules))
1820 lf->flags |= LINKER_FILE_MODULES;
1821 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1822 &si_stop, NULL) == 0)
1823 sysinit_add(si_start, si_stop);
1824 linker_file_register_sysctls(lf, true);
1825 lf->flags |= LINKER_FILE_LINKED;
1826 continue;
1827 fail:
1828 TAILQ_REMOVE(&depended_files, lf, loaded);
1829 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1830 }
1831 sx_xunlock(&kld_sx);
1832 /* woohoo! we made it! */
1833 }
1834 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, NULL);
1835
1836 static void
linker_mountroot(void * arg __unused)1837 linker_mountroot(void *arg __unused)
1838 {
1839 linker_file_t lf;
1840
1841 sx_xlock(&kld_sx);
1842 TAILQ_FOREACH (lf, &linker_files, link) {
1843 linker_ctf_load_file(lf);
1844 }
1845 sx_xunlock(&kld_sx);
1846 }
1847 EVENTHANDLER_DEFINE(mountroot, linker_mountroot, NULL, 0);
1848
1849 /*
1850 * Handle preload files that failed to load any modules.
1851 */
1852 static void
linker_preload_finish(void * arg)1853 linker_preload_finish(void *arg)
1854 {
1855 linker_file_t lf, nlf;
1856
1857 sx_xlock(&kld_sx);
1858 TAILQ_FOREACH_SAFE(lf, &linker_files, link, nlf) {
1859 if (lf == linker_kernel_file)
1860 continue;
1861
1862 /*
1863 * If all of the modules in this file failed to load, unload
1864 * the file and return an error of ENOEXEC. (Parity with
1865 * linker_load_file.)
1866 */
1867 if ((lf->flags & LINKER_FILE_MODULES) != 0 &&
1868 TAILQ_EMPTY(&lf->modules)) {
1869 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1870 continue;
1871 }
1872
1873 lf->flags &= ~LINKER_FILE_MODULES;
1874 lf->userrefs++; /* so we can (try to) kldunload it */
1875 }
1876 sx_xunlock(&kld_sx);
1877 }
1878
1879 /*
1880 * Attempt to run after all DECLARE_MODULE SYSINITs. Unfortunately they can be
1881 * scheduled at any subsystem and order, so run this as late as possible. init
1882 * becomes runnable in SI_SUB_KTHREAD_INIT, so go slightly before that.
1883 */
1884 SYSINIT(preload_finish, SI_SUB_KTHREAD_INIT - 100, SI_ORDER_MIDDLE,
1885 linker_preload_finish, NULL);
1886
1887 /*
1888 * Search for a not-loaded module by name.
1889 *
1890 * Modules may be found in the following locations:
1891 *
1892 * - preloaded (result is just the module name) - on disk (result is full path
1893 * to module)
1894 *
1895 * If the module name is qualified in any way (contains path, etc.) the we
1896 * simply return a copy of it.
1897 *
1898 * The search path can be manipulated via sysctl. Note that we use the ';'
1899 * character as a separator to be consistent with the bootloader.
1900 */
1901
1902 static char linker_hintfile[] = "linker.hints";
1903 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1904
1905 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path,
1906 sizeof(linker_path), "module load search path");
1907
1908 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1909
1910 static const char * const linker_ext_list[] = {
1911 "",
1912 ".ko",
1913 NULL
1914 };
1915
1916 /*
1917 * Check if file actually exists either with or without extension listed in
1918 * the linker_ext_list. (probably should be generic for the rest of the
1919 * kernel)
1920 */
1921 static char *
linker_lookup_file(const char * path,int pathlen,const char * name,int namelen,struct vattr * vap)1922 linker_lookup_file(const char *path, int pathlen, const char *name,
1923 int namelen, struct vattr *vap)
1924 {
1925 struct nameidata nd;
1926 struct thread *td = curthread; /* XXX */
1927 const char * const *cpp, *sep;
1928 char *result;
1929 int error, len, extlen, reclen, flags;
1930 __enum_uint8(vtype) type;
1931
1932 extlen = 0;
1933 for (cpp = linker_ext_list; *cpp; cpp++) {
1934 len = strlen(*cpp);
1935 if (len > extlen)
1936 extlen = len;
1937 }
1938 extlen++; /* trailing '\0' */
1939 sep = (path[pathlen - 1] != '/') ? "/" : "";
1940
1941 reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1942 result = malloc(reclen, M_LINKER, M_WAITOK);
1943 for (cpp = linker_ext_list; *cpp; cpp++) {
1944 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1945 namelen, name, *cpp);
1946 /*
1947 * Attempt to open the file, and return the path if
1948 * we succeed and it's a regular file.
1949 */
1950 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result);
1951 flags = FREAD;
1952 error = vn_open(&nd, &flags, 0, NULL);
1953 if (error == 0) {
1954 NDFREE_PNBUF(&nd);
1955 type = nd.ni_vp->v_type;
1956 if (vap)
1957 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1958 VOP_UNLOCK(nd.ni_vp);
1959 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1960 if (type == VREG)
1961 return (result);
1962 }
1963 }
1964 free(result, M_LINKER);
1965 return (NULL);
1966 }
1967
1968 #define INT_ALIGN(base, ptr) ptr = \
1969 (base) + roundup2((ptr) - (base), sizeof(int))
1970
1971 /*
1972 * Lookup KLD which contains requested module in the "linker.hints" file. If
1973 * version specification is available, then try to find the best KLD.
1974 * Otherwise just find the latest one.
1975 */
1976 static char *
linker_hints_lookup(const char * path,int pathlen,const char * modname,int modnamelen,const struct mod_depend * verinfo)1977 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1978 int modnamelen, const struct mod_depend *verinfo)
1979 {
1980 struct thread *td = curthread; /* XXX */
1981 struct ucred *cred = td ? td->td_ucred : NULL;
1982 struct nameidata nd;
1983 struct vattr vattr, mattr;
1984 const char *best, *sep;
1985 u_char *hints = NULL;
1986 u_char *cp, *recptr, *bufend, *result, *pathbuf;
1987 int error, ival, bestver, *intp, found, flags, clen, blen;
1988 ssize_t reclen;
1989
1990 result = NULL;
1991 bestver = found = 0;
1992
1993 sep = (path[pathlen - 1] != '/') ? "/" : "";
1994 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1995 strlen(sep) + 1;
1996 pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1997 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1998 linker_hintfile);
1999
2000 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf);
2001 flags = FREAD;
2002 error = vn_open(&nd, &flags, 0, NULL);
2003 if (error)
2004 goto bad;
2005 NDFREE_PNBUF(&nd);
2006 if (nd.ni_vp->v_type != VREG)
2007 goto bad;
2008 best = cp = NULL;
2009 error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
2010 if (error)
2011 goto bad;
2012 /*
2013 * XXX: we need to limit this number to some reasonable value
2014 */
2015 if (vattr.va_size > LINKER_HINTS_MAX) {
2016 printf("linker.hints file too large %ld\n", (long)vattr.va_size);
2017 goto bad;
2018 }
2019 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
2020 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
2021 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
2022 if (error)
2023 goto bad;
2024 VOP_UNLOCK(nd.ni_vp);
2025 vn_close(nd.ni_vp, FREAD, cred, td);
2026 nd.ni_vp = NULL;
2027 if (reclen != 0) {
2028 printf("can't read %zd\n", reclen);
2029 goto bad;
2030 }
2031 intp = (int *)hints;
2032 ival = *intp++;
2033 if (ival != LINKER_HINTS_VERSION) {
2034 printf("linker.hints file version mismatch %d\n", ival);
2035 goto bad;
2036 }
2037 bufend = hints + vattr.va_size;
2038 recptr = (u_char *)intp;
2039 clen = blen = 0;
2040 while (recptr < bufend && !found) {
2041 intp = (int *)recptr;
2042 reclen = *intp++;
2043 ival = *intp++;
2044 cp = (char *)intp;
2045 switch (ival) {
2046 case MDT_VERSION:
2047 clen = *cp++;
2048 if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
2049 break;
2050 cp += clen;
2051 INT_ALIGN(hints, cp);
2052 ival = *(int *)cp;
2053 cp += sizeof(int);
2054 clen = *cp++;
2055 if (verinfo == NULL ||
2056 ival == verinfo->md_ver_preferred) {
2057 found = 1;
2058 break;
2059 }
2060 if (ival >= verinfo->md_ver_minimum &&
2061 ival <= verinfo->md_ver_maximum &&
2062 ival > bestver) {
2063 bestver = ival;
2064 best = cp;
2065 blen = clen;
2066 }
2067 break;
2068 default:
2069 break;
2070 }
2071 recptr += reclen + sizeof(int);
2072 }
2073 /*
2074 * Finally check if KLD is in the place
2075 */
2076 if (found)
2077 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
2078 else if (best)
2079 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
2080
2081 /*
2082 * KLD is newer than hints file. What we should do now?
2083 */
2084 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
2085 printf("warning: KLD '%s' is newer than the linker.hints"
2086 " file\n", result);
2087 bad:
2088 free(pathbuf, M_LINKER);
2089 if (hints)
2090 free(hints, M_TEMP);
2091 if (nd.ni_vp != NULL) {
2092 VOP_UNLOCK(nd.ni_vp);
2093 vn_close(nd.ni_vp, FREAD, cred, td);
2094 }
2095 /*
2096 * If nothing found or hints is absent - fallback to the old
2097 * way by using "kldname[.ko]" as module name.
2098 */
2099 if (!found && !bestver && result == NULL)
2100 result = linker_lookup_file(path, pathlen, modname,
2101 modnamelen, NULL);
2102 return (result);
2103 }
2104
2105 /*
2106 * Lookup KLD which contains requested module in the all directories.
2107 */
2108 static char *
linker_search_module(const char * modname,int modnamelen,const struct mod_depend * verinfo)2109 linker_search_module(const char *modname, int modnamelen,
2110 const struct mod_depend *verinfo)
2111 {
2112 char *cp, *ep, *result;
2113
2114 /*
2115 * traverse the linker path
2116 */
2117 for (cp = linker_path; *cp; cp = ep + 1) {
2118 /* find the end of this component */
2119 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
2120 result = linker_hints_lookup(cp, ep - cp, modname,
2121 modnamelen, verinfo);
2122 if (result != NULL)
2123 return (result);
2124 if (*ep == 0)
2125 break;
2126 }
2127 return (NULL);
2128 }
2129
2130 /*
2131 * Search for module in all directories listed in the linker_path.
2132 */
2133 static char *
linker_search_kld(const char * name)2134 linker_search_kld(const char *name)
2135 {
2136 char *cp, *ep, *result;
2137 int len;
2138
2139 /* qualified at all? */
2140 if (strchr(name, '/'))
2141 return (strdup(name, M_LINKER));
2142
2143 /* traverse the linker path */
2144 len = strlen(name);
2145 for (ep = linker_path; *ep; ep++) {
2146 cp = ep;
2147 /* find the end of this component */
2148 for (; *ep != 0 && *ep != ';'; ep++);
2149 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
2150 if (result != NULL)
2151 return (result);
2152 }
2153 return (NULL);
2154 }
2155
2156 static const char *
linker_basename(const char * path)2157 linker_basename(const char *path)
2158 {
2159 const char *filename;
2160
2161 filename = strrchr(path, '/');
2162 if (filename == NULL)
2163 return path;
2164 if (filename[1])
2165 filename++;
2166 return (filename);
2167 }
2168
2169 #ifdef HWPMC_HOOKS
2170 /*
2171 * Inform hwpmc about the set of kernel modules currently loaded.
2172 */
2173 void *
linker_hwpmc_list_objects(void)2174 linker_hwpmc_list_objects(void)
2175 {
2176 linker_file_t lf;
2177 struct pmckern_map_in *kobase;
2178 int i, nmappings;
2179
2180 nmappings = 0;
2181 sx_slock(&kld_sx);
2182 TAILQ_FOREACH(lf, &linker_files, link)
2183 nmappings++;
2184
2185 /* Allocate nmappings + 1 entries. */
2186 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
2187 M_LINKER, M_WAITOK | M_ZERO);
2188 i = 0;
2189 TAILQ_FOREACH(lf, &linker_files, link) {
2190 /* Save the info for this linker file. */
2191 kobase[i].pm_file = lf->pathname;
2192 kobase[i].pm_address = (uintptr_t)lf->address;
2193 i++;
2194 }
2195 sx_sunlock(&kld_sx);
2196
2197 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
2198
2199 /* The last entry of the malloced area comprises of all zeros. */
2200 KASSERT(kobase[i].pm_file == NULL,
2201 ("linker_hwpmc_list_objects: last object not NULL"));
2202
2203 return ((void *)kobase);
2204 }
2205 #endif
2206
2207 /* check if root file system is not mounted */
2208 static bool
linker_root_mounted(void)2209 linker_root_mounted(void)
2210 {
2211 struct pwd *pwd;
2212 bool ret;
2213
2214 if (rootvnode == NULL)
2215 return (false);
2216
2217 pwd = pwd_hold(curthread);
2218 ret = pwd->pwd_rdir != NULL;
2219 pwd_drop(pwd);
2220 return (ret);
2221 }
2222
2223 /*
2224 * Find a file which contains given module and load it, if "parent" is not
2225 * NULL, register a reference to it.
2226 */
2227 static int
linker_load_module(const char * kldname,const char * modname,struct linker_file * parent,const struct mod_depend * verinfo,struct linker_file ** lfpp)2228 linker_load_module(const char *kldname, const char *modname,
2229 struct linker_file *parent, const struct mod_depend *verinfo,
2230 struct linker_file **lfpp)
2231 {
2232 linker_file_t lfdep;
2233 const char *filename;
2234 char *pathname;
2235 int error;
2236
2237 sx_assert(&kld_sx, SA_XLOCKED);
2238 if (modname == NULL) {
2239 /*
2240 * We have to load KLD
2241 */
2242 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
2243 " is not NULL"));
2244 if (!linker_root_mounted())
2245 return (ENXIO);
2246 pathname = linker_search_kld(kldname);
2247 } else {
2248 if (modlist_lookup2(modname, verinfo) != NULL)
2249 return (EEXIST);
2250 if (!linker_root_mounted())
2251 return (ENXIO);
2252 if (kldname != NULL)
2253 pathname = strdup(kldname, M_LINKER);
2254 else
2255 /*
2256 * Need to find a KLD with required module
2257 */
2258 pathname = linker_search_module(modname,
2259 strlen(modname), verinfo);
2260 }
2261 if (pathname == NULL)
2262 return (ENOENT);
2263
2264 /*
2265 * Can't load more than one file with the same basename XXX:
2266 * Actually it should be possible to have multiple KLDs with
2267 * the same basename but different path because they can
2268 * provide different versions of the same modules.
2269 */
2270 filename = linker_basename(pathname);
2271 if (linker_find_file_by_name(filename))
2272 error = EEXIST;
2273 else do {
2274 error = linker_load_file(pathname, &lfdep);
2275 if (error)
2276 break;
2277 if (modname && verinfo &&
2278 modlist_lookup2(modname, verinfo) == NULL) {
2279 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2280 error = ENOENT;
2281 break;
2282 }
2283 if (parent)
2284 linker_file_add_dependency(parent, lfdep);
2285 if (lfpp)
2286 *lfpp = lfdep;
2287 } while (0);
2288 free(pathname, M_LINKER);
2289 return (error);
2290 }
2291
2292 /*
2293 * This routine is responsible for finding dependencies of userland initiated
2294 * kldload(2)'s of files.
2295 */
2296 int
linker_load_dependencies(linker_file_t lf)2297 linker_load_dependencies(linker_file_t lf)
2298 {
2299 linker_file_t lfdep;
2300 struct mod_metadata **start, **stop, **mdp, **nmdp;
2301 struct mod_metadata *mp, *nmp;
2302 const struct mod_depend *verinfo;
2303 modlist_t mod;
2304 const char *modname, *nmodname;
2305 int ver, error = 0;
2306
2307 /*
2308 * All files are dependent on /kernel.
2309 */
2310 sx_assert(&kld_sx, SA_XLOCKED);
2311 if (linker_kernel_file) {
2312 linker_kernel_file->refs++;
2313 linker_file_add_dependency(lf, linker_kernel_file);
2314 }
2315 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2316 NULL) != 0)
2317 return (0);
2318 for (mdp = start; mdp < stop; mdp++) {
2319 mp = *mdp;
2320 if (mp->md_type != MDT_VERSION)
2321 continue;
2322 modname = mp->md_cval;
2323 ver = ((const struct mod_version *)mp->md_data)->mv_version;
2324 mod = modlist_lookup(modname, ver);
2325 if (mod != NULL) {
2326 printf("interface %s.%d already present in the KLD"
2327 " '%s'!\n", modname, ver,
2328 mod->container->filename);
2329 return (EEXIST);
2330 }
2331 }
2332
2333 for (mdp = start; mdp < stop; mdp++) {
2334 mp = *mdp;
2335 if (mp->md_type != MDT_DEPEND)
2336 continue;
2337 modname = mp->md_cval;
2338 verinfo = mp->md_data;
2339 nmodname = NULL;
2340 for (nmdp = start; nmdp < stop; nmdp++) {
2341 nmp = *nmdp;
2342 if (nmp->md_type != MDT_VERSION)
2343 continue;
2344 nmodname = nmp->md_cval;
2345 if (strcmp(modname, nmodname) == 0)
2346 break;
2347 }
2348 if (nmdp < stop)/* early exit, it's a self reference */
2349 continue;
2350 mod = modlist_lookup2(modname, verinfo);
2351 if (mod) { /* woohoo, it's loaded already */
2352 lfdep = mod->container;
2353 lfdep->refs++;
2354 linker_file_add_dependency(lf, lfdep);
2355 continue;
2356 }
2357 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2358 if (error) {
2359 printf("KLD %s: depends on %s - not available or"
2360 " version mismatch\n", lf->filename, modname);
2361 break;
2362 }
2363 }
2364
2365 if (error)
2366 return (error);
2367 linker_addmodules(lf, start, stop, 0);
2368 return (error);
2369 }
2370
2371 static int
sysctl_kern_function_list_iterate(const char * name,void * opaque)2372 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2373 {
2374 struct sysctl_req *req;
2375
2376 req = opaque;
2377 return (SYSCTL_OUT(req, name, strlen(name) + 1));
2378 }
2379
2380 /*
2381 * Export a nul-separated, double-nul-terminated list of all function names
2382 * in the kernel.
2383 */
2384 static int
sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)2385 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2386 {
2387 linker_file_t lf;
2388 int error;
2389
2390 #ifdef MAC
2391 error = mac_kld_check_stat(req->td->td_ucred);
2392 if (error)
2393 return (error);
2394 #endif
2395 error = sysctl_wire_old_buffer(req, 0);
2396 if (error != 0)
2397 return (error);
2398 sx_xlock(&kld_sx);
2399 TAILQ_FOREACH(lf, &linker_files, link) {
2400 error = LINKER_EACH_FUNCTION_NAME(lf,
2401 sysctl_kern_function_list_iterate, req);
2402 if (error) {
2403 sx_xunlock(&kld_sx);
2404 return (error);
2405 }
2406 }
2407 sx_xunlock(&kld_sx);
2408 return (SYSCTL_OUT(req, "", 1));
2409 }
2410
2411 SYSCTL_PROC(_kern, OID_AUTO, function_list,
2412 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
2413 sysctl_kern_function_list, "",
2414 "kernel function list");
2415