xref: /netbsd-src/sys/kern/kern_module.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: kern_module.c,v 1.132 2018/09/03 16:29:35 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software developed for The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Kernel module support.
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: kern_module.c,v 1.132 2018/09/03 16:29:35 riastradh Exp $");
38 
39 #define _MODULE_INTERNAL
40 
41 #ifdef _KERNEL_OPT
42 #include "opt_ddb.h"
43 #include "opt_modular.h"
44 #endif
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/proc.h>
50 #include <sys/kauth.h>
51 #include <sys/kobj.h>
52 #include <sys/kmem.h>
53 #include <sys/module.h>
54 #include <sys/kthread.h>
55 #include <sys/sysctl.h>
56 #include <sys/lock.h>
57 
58 #include <uvm/uvm_extern.h>
59 
60 struct vm_map *module_map;
61 const char *module_machine;
62 char	module_base[MODULE_BASE_SIZE];
63 
64 struct modlist        module_list = TAILQ_HEAD_INITIALIZER(module_list);
65 struct modlist        module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins);
66 static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist);
67 
68 struct module_callbacks {
69 	TAILQ_ENTRY(module_callbacks) modcb_list;
70 	void (*modcb_load)(struct module *);
71 	void (*modcb_unload)(struct module *);
72 };
73 TAILQ_HEAD(modcblist, module_callbacks);
74 static struct modcblist modcblist;
75 
76 static module_t *module_netbsd;
77 static const modinfo_t module_netbsd_modinfo = {
78 	.mi_version = __NetBSD_Version__,
79 	.mi_class = MODULE_CLASS_MISC,
80 	.mi_name = "netbsd"
81 };
82 
83 static module_t	*module_active;
84 bool		module_verbose_on;
85 #ifdef MODULAR_DEFAULT_AUTOLOAD
86 bool		module_autoload_on = true;
87 #else
88 bool		module_autoload_on = false;
89 #endif
90 u_int		module_count;
91 u_int		module_builtinlist;
92 u_int		module_autotime = 10;
93 u_int		module_gen = 1;
94 static kcondvar_t module_thread_cv;
95 static kmutex_t module_thread_lock;
96 static int	module_thread_ticks;
97 int (*module_load_vfs_vec)(const char *, int, bool, module_t *,
98 			   prop_dictionary_t *) = (void *)eopnotsupp;
99 
100 static kauth_listener_t	module_listener;
101 
102 static specificdata_domain_t module_specificdata_domain;
103 
104 /* Ensure that the kernel's link set isn't empty. */
105 static modinfo_t module_dummy;
106 __link_set_add_rodata(modules, module_dummy);
107 
108 static module_t	*module_newmodule(modsrc_t);
109 static void	module_free(module_t *);
110 static void	module_require_force(module_t *);
111 static int	module_do_load(const char *, bool, int, prop_dictionary_t,
112 		    module_t **, modclass_t modclass, bool);
113 static int	module_do_unload(const char *, bool);
114 static int	module_do_builtin(const module_t *, const char *, module_t **,
115     prop_dictionary_t);
116 static int	module_fetch_info(module_t *);
117 static void	module_thread(void *);
118 
119 static module_t	*module_lookup(const char *);
120 static void	module_enqueue(module_t *);
121 
122 static bool	module_merge_dicts(prop_dictionary_t, const prop_dictionary_t);
123 
124 static void	sysctl_module_setup(void);
125 static int	sysctl_module_autotime(SYSCTLFN_PROTO);
126 
127 static void	module_callback_load(struct module *);
128 static void	module_callback_unload(struct module *);
129 
130 #define MODULE_CLASS_MATCH(mi, modclass) \
131 	((modclass) == MODULE_CLASS_ANY || (modclass) == (mi)->mi_class)
132 
133 static void
134 module_incompat(const modinfo_t *mi, int modclass)
135 {
136 	module_error("incompatible module class for `%s' (%d != %d)",
137 	    mi->mi_name, modclass, mi->mi_class);
138 }
139 
140 struct module *
141 module_kernel(void)
142 {
143 
144 	return module_netbsd;
145 }
146 
147 /*
148  * module_error:
149  *
150  *	Utility function: log an error.
151  */
152 void
153 module_error(const char *fmt, ...)
154 {
155 	va_list ap;
156 
157 	va_start(ap, fmt);
158 	printf("WARNING: module error: ");
159 	vprintf(fmt, ap);
160 	printf("\n");
161 	va_end(ap);
162 }
163 
164 /*
165  * module_print:
166  *
167  *	Utility function: log verbose output.
168  */
169 void
170 module_print(const char *fmt, ...)
171 {
172 	va_list ap;
173 
174 	if (module_verbose_on) {
175 		va_start(ap, fmt);
176 		printf("DEBUG: module: ");
177 		vprintf(fmt, ap);
178 		printf("\n");
179 		va_end(ap);
180 	}
181 }
182 
183 /*
184  * module_name:
185  *
186  *	Utility function: return the module's name.
187  */
188 const char *
189 module_name(struct module *mod)
190 {
191 
192 	return mod->mod_info->mi_name;
193 }
194 
195 /*
196  * module_source:
197  *
198  *	Utility function: return the module's source.
199  */
200 modsrc_t
201 module_source(struct module *mod)
202 {
203 
204 	return mod->mod_source;
205 }
206 
207 static int
208 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
209     void *arg0, void *arg1, void *arg2, void *arg3)
210 {
211 	int result;
212 
213 	result = KAUTH_RESULT_DEFER;
214 
215 	if (action != KAUTH_SYSTEM_MODULE)
216 		return result;
217 
218 	if ((uintptr_t)arg2 != 0)	/* autoload */
219 		result = KAUTH_RESULT_ALLOW;
220 
221 	return result;
222 }
223 
224 /*
225  * Allocate a new module_t
226  */
227 static module_t *
228 module_newmodule(modsrc_t source)
229 {
230 	module_t *mod;
231 
232 	mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
233 	mod->mod_source = source;
234 	specificdata_init(module_specificdata_domain, &mod->mod_sdref);
235 	return mod;
236 }
237 
238 /*
239  * Free a module_t
240  */
241 static void
242 module_free(module_t *mod)
243 {
244 
245 	specificdata_fini(module_specificdata_domain, &mod->mod_sdref);
246 	kmem_free(mod, sizeof(*mod));
247 }
248 
249 /*
250  * Require the -f (force) flag to load a module
251  */
252 static void
253 module_require_force(struct module *mod)
254 {
255 	mod->mod_flags |= MODFLG_MUST_FORCE;
256 }
257 
258 /*
259  * Add modules to the builtin list.  This can done at boottime or
260  * at runtime if the module is linked into the kernel with an
261  * external linker.  All or none of the input will be handled.
262  * Optionally, the modules can be initialized.  If they are not
263  * initialized, module_init_class() or module_load() can be used
264  * later, but these are not guaranteed to give atomic results.
265  */
266 int
267 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init)
268 {
269 	struct module **modp = NULL, *mod_iter;
270 	int rv = 0, i, mipskip;
271 
272 	if (init) {
273 		rv = kauth_authorize_system(kauth_cred_get(),
274 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD,
275 		    (void *)(uintptr_t)1, NULL);
276 		if (rv) {
277 			return rv;
278 		}
279 	}
280 
281 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
282 		if (mip[i] == &module_dummy) {
283 			KASSERT(nmodinfo > 0);
284 			nmodinfo--;
285 		}
286 	}
287 	if (nmodinfo == 0)
288 		return 0;
289 
290 	modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP);
291 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
292 		if (mip[i+mipskip] == &module_dummy) {
293 			mipskip++;
294 			continue;
295 		}
296 		modp[i] = module_newmodule(MODULE_SOURCE_KERNEL);
297 		modp[i]->mod_info = mip[i+mipskip];
298 	}
299 	kernconfig_lock();
300 
301 	/* do this in three stages for error recovery and atomicity */
302 
303 	/* first check for presence */
304 	for (i = 0; i < nmodinfo; i++) {
305 		TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) {
306 			if (strcmp(mod_iter->mod_info->mi_name,
307 			    modp[i]->mod_info->mi_name) == 0)
308 				break;
309 		}
310 		if (mod_iter) {
311 			rv = EEXIST;
312 			goto out;
313 		}
314 
315 		if (module_lookup(modp[i]->mod_info->mi_name) != NULL) {
316 			rv = EEXIST;
317 			goto out;
318 		}
319 	}
320 
321 	/* then add to list */
322 	for (i = 0; i < nmodinfo; i++) {
323 		TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain);
324 		module_builtinlist++;
325 	}
326 
327 	/* finally, init (if required) */
328 	if (init) {
329 		for (i = 0; i < nmodinfo; i++) {
330 			rv = module_do_builtin(modp[i],
331 			    modp[i]->mod_info->mi_name, NULL, NULL);
332 			/* throw in the towel, recovery hard & not worth it */
333 			if (rv)
334 				panic("%s: builtin module \"%s\" init failed:"
335 				    " %d", __func__,
336 				    modp[i]->mod_info->mi_name, rv);
337 		}
338 	}
339 
340  out:
341 	kernconfig_unlock();
342 	if (rv != 0) {
343 		for (i = 0; i < nmodinfo; i++) {
344 			if (modp[i])
345 				module_free(modp[i]);
346 		}
347 	}
348 	kmem_free(modp, sizeof(*modp) * nmodinfo);
349 	return rv;
350 }
351 
352 /*
353  * Optionally fini and remove builtin module from the kernel.
354  * Note: the module will now be unreachable except via mi && builtin_add.
355  */
356 int
357 module_builtin_remove(modinfo_t *mi, bool fini)
358 {
359 	struct module *mod;
360 	int rv = 0;
361 
362 	if (fini) {
363 		rv = kauth_authorize_system(kauth_cred_get(),
364 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD,
365 		    NULL, NULL);
366 		if (rv)
367 			return rv;
368 
369 		kernconfig_lock();
370 		rv = module_do_unload(mi->mi_name, true);
371 		if (rv) {
372 			goto out;
373 		}
374 	} else {
375 		kernconfig_lock();
376 	}
377 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
378 		if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0)
379 			break;
380 	}
381 	if (mod) {
382 		TAILQ_REMOVE(&module_builtins, mod, mod_chain);
383 		module_builtinlist--;
384 	} else {
385 		KASSERT(fini == false);
386 		rv = ENOENT;
387 	}
388 
389  out:
390 	kernconfig_unlock();
391 	return rv;
392 }
393 
394 /*
395  * module_init:
396  *
397  *	Initialize the module subsystem.
398  */
399 void
400 module_init(void)
401 {
402 	__link_set_decl(modules, modinfo_t);
403 	extern struct vm_map *module_map;
404 	modinfo_t *const *mip;
405 	int rv;
406 
407 	if (module_map == NULL) {
408 		module_map = kernel_map;
409 	}
410 	cv_init(&module_thread_cv, "mod_unld");
411 	mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE);
412 	TAILQ_INIT(&modcblist);
413 
414 #ifdef MODULAR	/* XXX */
415 	module_init_md();
416 #endif
417 
418 	if (!module_machine)
419 		module_machine = machine;
420 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
421 	snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules",
422 	    module_machine, osrelease);
423 #else						/* release */
424 	snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules",
425 	    module_machine, __NetBSD_Version__ / 100000000,
426 	    __NetBSD_Version__ / 1000000 % 100);
427 #endif
428 
429 	module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
430 	    module_listener_cb, NULL);
431 
432 	__link_set_foreach(mip, modules) {
433 		if ((rv = module_builtin_add(mip, 1, false)) != 0)
434 			module_error("builtin %s failed: %d\n",
435 			    (*mip)->mi_name, rv);
436 	}
437 
438 	sysctl_module_setup();
439 	module_specificdata_domain = specificdata_domain_create();
440 
441 	module_netbsd = module_newmodule(MODULE_SOURCE_KERNEL);
442 	module_netbsd->mod_refcnt = 1;
443 	module_netbsd->mod_info = &module_netbsd_modinfo;
444 }
445 
446 /*
447  * module_start_unload_thread:
448  *
449  *	Start the auto unload kthread.
450  */
451 void
452 module_start_unload_thread(void)
453 {
454 	int error;
455 
456 	error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread,
457 	    NULL, NULL, "modunload");
458 	if (error != 0)
459 		panic("%s: %d", __func__, error);
460 }
461 
462 /*
463  * module_builtin_require_force
464  *
465  * Require MODCTL_MUST_FORCE to load any built-in modules that have
466  * not yet been initialized
467  */
468 void
469 module_builtin_require_force(void)
470 {
471 	module_t *mod;
472 
473 	kernconfig_lock();
474 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
475 		module_require_force(mod);
476 	}
477 	kernconfig_unlock();
478 }
479 
480 static struct sysctllog *module_sysctllog;
481 
482 static int
483 sysctl_module_autotime(SYSCTLFN_ARGS)
484 {
485 	struct sysctlnode node;
486 	int t, error;
487 
488 	t = *(int *)rnode->sysctl_data;
489 
490 	node = *rnode;
491 	node.sysctl_data = &t;
492 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
493 	if (error || newp == NULL)
494 		return (error);
495 
496 	if (t < 0)
497 		return (EINVAL);
498 
499 	*(int *)rnode->sysctl_data = t;
500 	return (0);
501 }
502 
503 static void
504 sysctl_module_setup(void)
505 {
506 	const struct sysctlnode *node = NULL;
507 
508 	sysctl_createv(&module_sysctllog, 0, NULL, &node,
509 		CTLFLAG_PERMANENT,
510 		CTLTYPE_NODE, "module",
511 		SYSCTL_DESCR("Module options"),
512 		NULL, 0, NULL, 0,
513 		CTL_KERN, CTL_CREATE, CTL_EOL);
514 
515 	if (node == NULL)
516 		return;
517 
518 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
519 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
520 		CTLTYPE_BOOL, "autoload",
521 		SYSCTL_DESCR("Enable automatic load of modules"),
522 		NULL, 0, &module_autoload_on, 0,
523 		CTL_CREATE, CTL_EOL);
524 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
525 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
526 		CTLTYPE_BOOL, "verbose",
527 		SYSCTL_DESCR("Enable verbose output"),
528 		NULL, 0, &module_verbose_on, 0,
529 		CTL_CREATE, CTL_EOL);
530 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
531 		CTLFLAG_PERMANENT | CTLFLAG_READONLY,
532 		CTLTYPE_STRING, "path",
533 		SYSCTL_DESCR("Default module load path"),
534 		NULL, 0, module_base, 0,
535 		CTL_CREATE, CTL_EOL);
536 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
537 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
538 		CTLTYPE_INT, "autotime",
539 		SYSCTL_DESCR("Auto-unload delay"),
540 		sysctl_module_autotime, 0, &module_autotime, 0,
541 		CTL_CREATE, CTL_EOL);
542 }
543 
544 /*
545  * module_init_class:
546  *
547  *	Initialize all built-in and pre-loaded modules of the
548  *	specified class.
549  */
550 void
551 module_init_class(modclass_t modclass)
552 {
553 	TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail);
554 	module_t *mod;
555 	modinfo_t *mi;
556 
557 	kernconfig_lock();
558 	/*
559 	 * Builtins first.  These will not depend on pre-loaded modules
560 	 * (because the kernel would not link).
561 	 */
562 	do {
563 		TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
564 			mi = mod->mod_info;
565 			if (!MODULE_CLASS_MATCH(mi, modclass))
566 				continue;
567 			/*
568 			 * If initializing a builtin module fails, don't try
569 			 * to load it again.  But keep it around and queue it
570 			 * on the builtins list after we're done with module
571 			 * init.  Don't set it to MODFLG_MUST_FORCE in case a
572 			 * future attempt to initialize can be successful.
573 			 * (If the module has previously been set to
574 			 * MODFLG_MUST_FORCE, don't try to override that!)
575 			 */
576 			if ((mod->mod_flags & MODFLG_MUST_FORCE) ||
577 			    module_do_builtin(mod, mi->mi_name, NULL,
578 			    NULL) != 0) {
579 				TAILQ_REMOVE(&module_builtins, mod, mod_chain);
580 				TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain);
581 			}
582 			break;
583 		}
584 	} while (mod != NULL);
585 
586 	/*
587 	 * Now preloaded modules.  These will be pulled off the
588 	 * list as we call module_do_load();
589 	 */
590 	do {
591 		TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
592 			mi = mod->mod_info;
593 			if (!MODULE_CLASS_MATCH(mi, modclass))
594 				continue;
595 			module_do_load(mi->mi_name, false, 0, NULL, NULL,
596 			    modclass, false);
597 			break;
598 		}
599 	} while (mod != NULL);
600 
601 	/* return failed builtin modules to builtin list */
602 	while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) {
603 		TAILQ_REMOVE(&bi_fail, mod, mod_chain);
604 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
605 	}
606 
607 	kernconfig_unlock();
608 }
609 
610 /*
611  * module_compatible:
612  *
613  *	Return true if the two supplied kernel versions are said to
614  *	have the same binary interface for kernel code.  The entire
615  *	version is signficant for the development tree (-current),
616  *	major and minor versions are significant for official
617  *	releases of the system.
618  */
619 bool
620 module_compatible(int v1, int v2)
621 {
622 
623 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
624 	return v1 == v2;
625 #else						/* release */
626 	return abs(v1 - v2) < 10000;
627 #endif
628 }
629 
630 /*
631  * module_load:
632  *
633  *	Load a single module from the file system.
634  */
635 int
636 module_load(const char *filename, int flags, prop_dictionary_t props,
637 	    modclass_t modclass)
638 {
639 	module_t *mod;
640 	int error;
641 
642 	/* Test if we already have the module loaded before
643 	 * authorizing so we have the opportunity to return EEXIST. */
644 	kernconfig_lock();
645 	mod = module_lookup(filename);
646 	if (mod != NULL) {
647 		module_print("%s module `%s' already loaded",
648 		    "requested", filename);
649 		error = EEXIST;
650 		goto out;
651 	}
652 
653 	/* Authorize. */
654 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
655 	    0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL);
656 	if (error != 0)
657 		goto out;
658 
659 	error = module_do_load(filename, false, flags, props, NULL, modclass,
660 	    false);
661 
662 out:
663 	kernconfig_unlock();
664 	return error;
665 }
666 
667 /*
668  * module_autoload:
669  *
670  *	Load a single module from the file system, system initiated.
671  */
672 int
673 module_autoload(const char *filename, modclass_t modclass)
674 {
675 	int error;
676 
677 	kernconfig_lock();
678 
679 	/* Nothing if the user has disabled it. */
680 	if (!module_autoload_on) {
681 		kernconfig_unlock();
682 		return EPERM;
683 	}
684 
685         /* Disallow path separators and magic symlinks. */
686         if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL ||
687             strchr(filename, '.') != NULL) {
688 		kernconfig_unlock();
689         	return EPERM;
690 	}
691 
692 	/* Authorize. */
693 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
694 	    0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL);
695 
696 	if (error == 0)
697 		error = module_do_load(filename, false, 0, NULL, NULL, modclass,
698 		    true);
699 
700 	kernconfig_unlock();
701 	return error;
702 }
703 
704 /*
705  * module_unload:
706  *
707  *	Find and unload a module by name.
708  */
709 int
710 module_unload(const char *name)
711 {
712 	int error;
713 
714 	/* Authorize. */
715 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
716 	    0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL);
717 	if (error != 0) {
718 		return error;
719 	}
720 
721 	kernconfig_lock();
722 	error = module_do_unload(name, true);
723 	kernconfig_unlock();
724 
725 	return error;
726 }
727 
728 /*
729  * module_lookup:
730  *
731  *	Look up a module by name.
732  */
733 module_t *
734 module_lookup(const char *name)
735 {
736 	module_t *mod;
737 
738 	KASSERT(kernconfig_is_held());
739 
740 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
741 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
742 			break;
743 		}
744 	}
745 
746 	return mod;
747 }
748 
749 /*
750  * module_hold:
751  *
752  *	Add a single reference to a module.  It's the caller's
753  *	responsibility to ensure that the reference is dropped
754  *	later.
755  */
756 void
757 module_hold(module_t *mod)
758 {
759 
760 	kernconfig_lock();
761 	mod->mod_refcnt++;
762 	kernconfig_unlock();
763 }
764 
765 /*
766  * module_rele:
767  *
768  *	Release a reference acquired with module_hold().
769  */
770 void
771 module_rele(module_t *mod)
772 {
773 
774 	kernconfig_lock();
775 	KASSERT(mod->mod_refcnt > 0);
776 	mod->mod_refcnt--;
777 	kernconfig_unlock();
778 }
779 
780 /*
781  * module_enqueue:
782  *
783  *	Put a module onto the global list and update counters.
784  */
785 void
786 module_enqueue(module_t *mod)
787 {
788 	int i;
789 
790 	KASSERT(kernconfig_is_held());
791 
792 	/*
793 	 * Put new entry at the head of the queue so autounload can unload
794 	 * requisite modules with only one pass through the queue.
795 	 */
796 	TAILQ_INSERT_HEAD(&module_list, mod, mod_chain);
797 	if (mod->mod_nrequired) {
798 
799 		/* Add references to the requisite modules. */
800 		for (i = 0; i < mod->mod_nrequired; i++) {
801 			KASSERT(mod->mod_required[i] != NULL);
802 			mod->mod_required[i]->mod_refcnt++;
803 		}
804 	}
805 	module_count++;
806 	module_gen++;
807 }
808 
809 /*
810  * module_do_builtin:
811  *
812  *	Initialize a module from the list of modules that are
813  *	already linked into the kernel.
814  */
815 static int
816 module_do_builtin(const module_t *pmod, const char *name, module_t **modp,
817     prop_dictionary_t props)
818 {
819 	const char *p, *s;
820 	char buf[MAXMODNAME];
821 	modinfo_t *mi = NULL;
822 	module_t *mod, *mod2, *mod_loaded, *prev_active;
823 	size_t len;
824 	int error;
825 
826 	KASSERT(kernconfig_is_held());
827 
828 	/*
829 	 * Search the list to see if we have a module by this name.
830 	 */
831 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
832 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
833 			mi = mod->mod_info;
834 			break;
835 		}
836 	}
837 
838 	/*
839 	 * Check to see if already loaded.  This might happen if we
840 	 * were already loaded as a dependency.
841 	 */
842 	if ((mod_loaded = module_lookup(name)) != NULL) {
843 		KASSERT(mod == NULL);
844 		if (modp)
845 			*modp = mod_loaded;
846 		return 0;
847 	}
848 
849 	/* Note! This is from TAILQ, not immediate above */
850 	if (mi == NULL) {
851 		/*
852 		 * XXX: We'd like to panic here, but currently in some
853 		 * cases (such as nfsserver + nfs), the dependee can be
854 		 * succesfully linked without the dependencies.
855 		 */
856 		module_error("%s: can't find builtin dependency `%s'",
857 		    pmod->mod_info->mi_name, name);
858 		return ENOENT;
859 	}
860 
861 	/*
862 	 * Initialize pre-requisites.
863 	 */
864 	if (mi->mi_required != NULL) {
865 		for (s = mi->mi_required; *s != '\0'; s = p) {
866 			if (*s == ',')
867 				s++;
868 			p = s;
869 			while (*p != '\0' && *p != ',')
870 				p++;
871 			len = uimin(p - s + 1, sizeof(buf));
872 			strlcpy(buf, s, len);
873 			if (buf[0] == '\0')
874 				break;
875 			if (mod->mod_nrequired == MAXMODDEPS - 1) {
876 				module_error("%s: too many required modules "
877 				    "%d >= %d", pmod->mod_info->mi_name,
878 				    mod->mod_nrequired, MAXMODDEPS - 1);
879 				return EINVAL;
880 			}
881 			error = module_do_builtin(mod, buf, &mod2, NULL);
882 			if (error != 0) {
883 				return error;
884 			}
885 			mod->mod_required[mod->mod_nrequired++] = mod2;
886 		}
887 	}
888 
889 	/*
890 	 * Try to initialize the module.
891 	 */
892 	prev_active = module_active;
893 	module_active = mod;
894 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props);
895 	module_active = prev_active;
896 	if (error != 0) {
897 		module_error("builtin module `%s' "
898 		    "failed to init, error %d", mi->mi_name, error);
899 		return error;
900 	}
901 
902 	/* load always succeeds after this point */
903 
904 	TAILQ_REMOVE(&module_builtins, mod, mod_chain);
905 	module_builtinlist--;
906 	if (modp != NULL) {
907 		*modp = mod;
908 	}
909 	module_enqueue(mod);
910 	return 0;
911 }
912 
913 /*
914  * module_do_load:
915  *
916  *	Helper routine: load a module from the file system, or one
917  *	pushed by the boot loader.
918  */
919 static int
920 module_do_load(const char *name, bool isdep, int flags,
921 	       prop_dictionary_t props, module_t **modp, modclass_t modclass,
922 	       bool autoload)
923 {
924 #define MODULE_MAX_DEPTH 6
925 
926 	TAILQ_HEAD(pending_t, module);
927 	static int depth = 0;
928 	static struct pending_t *pending_lists[MODULE_MAX_DEPTH];
929 	struct pending_t *pending;
930 	struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending);
931 	modinfo_t *mi;
932 	module_t *mod, *mod2, *prev_active;
933 	prop_dictionary_t filedict;
934 	char buf[MAXMODNAME];
935 	const char *s, *p;
936 	int error;
937 	size_t len;
938 
939 	KASSERT(kernconfig_is_held());
940 
941 	filedict = NULL;
942 	error = 0;
943 
944 	/*
945 	 * Avoid recursing too far.
946 	 */
947 	if (++depth > MODULE_MAX_DEPTH) {
948 		module_error("recursion too deep for `%s' %d > %d", name,
949 		    depth, MODULE_MAX_DEPTH);
950 		depth--;
951 		return EMLINK;
952 	}
953 
954 	/*
955 	 * Set up the pending list for this depth.  If this is a
956 	 * recursive entry, then use same list as for outer call,
957 	 * else use the locally allocated list.  In either case,
958 	 * remember which one we're using.
959 	 */
960 	if (isdep) {
961 		KASSERT(depth > 1);
962 		pending = pending_lists[depth - 2];
963 	} else
964 		pending = &new_pending;
965 	pending_lists[depth - 1] = pending;
966 
967 	/*
968 	 * Search the list of disabled builtins first.
969 	 */
970 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
971 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
972 			break;
973 		}
974 	}
975 	if (mod) {
976 		if ((mod->mod_flags & MODFLG_MUST_FORCE) &&
977 		    (flags & MODCTL_LOAD_FORCE) == 0) {
978 			if (!autoload) {
979 				module_error("use -f to reinstate "
980 				    "builtin module `%s'", name);
981 			}
982 			depth--;
983 			return EPERM;
984 		} else {
985 			error = module_do_builtin(mod, name, modp, props);
986 			depth--;
987 			return error;
988 		}
989 	}
990 
991 	/*
992 	 * Load the module and link.  Before going to the file system,
993 	 * scan the list of modules loaded by the boot loader.
994 	 */
995 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
996 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
997 			TAILQ_REMOVE(&module_bootlist, mod, mod_chain);
998 			break;
999 		}
1000 	}
1001 	if (mod != NULL) {
1002 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1003 	} else {
1004 		/*
1005 		 * Check to see if module is already present.
1006 		 */
1007 		mod = module_lookup(name);
1008 		if (mod != NULL) {
1009 			if (modp != NULL) {
1010 				*modp = mod;
1011 			}
1012 			module_print("%s module `%s' already loaded",
1013 			    isdep ? "dependent" : "requested", name);
1014 			depth--;
1015 			return EEXIST;
1016 		}
1017 
1018 		mod = module_newmodule(MODULE_SOURCE_FILESYS);
1019 		if (mod == NULL) {
1020 			module_error("out of memory for `%s'", name);
1021 			depth--;
1022 			return ENOMEM;
1023 		}
1024 
1025 		error = module_load_vfs_vec(name, flags, autoload, mod,
1026 					    &filedict);
1027 		if (error != 0) {
1028 #ifdef DEBUG
1029 			/*
1030 			 * The exec class of modules contains a list of
1031 			 * modules that is the union of all the modules
1032 			 * available for each architecture, so we don't
1033 			 * print an error if they are missing.
1034 			 */
1035 			if ((modclass != MODULE_CLASS_EXEC || error != ENOENT)
1036 			    && root_device != NULL)
1037 				module_error("vfs load failed for `%s', "
1038 				    "error %d", name, error);
1039 #endif
1040 			module_free(mod);
1041 			depth--;
1042 			return error;
1043 		}
1044 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1045 
1046 		error = module_fetch_info(mod);
1047 		if (error != 0) {
1048 			module_error("cannot fetch info for `%s', error %d",
1049 			    name, error);
1050 			goto fail;
1051 		}
1052 	}
1053 
1054 	/*
1055 	 * Check compatibility.
1056 	 */
1057 	mi = mod->mod_info;
1058 	if (strlen(mi->mi_name) >= MAXMODNAME) {
1059 		error = EINVAL;
1060 		module_error("module name `%s' longer than %d", mi->mi_name,
1061 		    MAXMODNAME);
1062 		goto fail;
1063 	}
1064 	if (!module_compatible(mi->mi_version, __NetBSD_Version__)) {
1065 		module_error("module `%s' built for `%d', system `%d'",
1066 		    mi->mi_name, mi->mi_version, __NetBSD_Version__);
1067 		if ((flags & MODCTL_LOAD_FORCE) != 0) {
1068 			module_error("forced load, system may be unstable");
1069 		} else {
1070 			error = EPROGMISMATCH;
1071 			goto fail;
1072 		}
1073 	}
1074 
1075 	/*
1076 	 * If a specific kind of module was requested, ensure that we have
1077 	 * a match.
1078 	 */
1079 	if (!MODULE_CLASS_MATCH(mi, modclass)) {
1080 		module_incompat(mi, modclass);
1081 		error = ENOENT;
1082 		goto fail;
1083 	}
1084 
1085 	/*
1086 	 * If loading a dependency, `name' is a plain module name.
1087 	 * The name must match.
1088 	 */
1089 	if (isdep && strcmp(mi->mi_name, name) != 0) {
1090 		module_error("dependency name mismatch (`%s' != `%s')",
1091 		    name, mi->mi_name);
1092 		error = ENOENT;
1093 		goto fail;
1094 	}
1095 
1096 	/*
1097 	 * If we loaded a module from the filesystem, check the actual
1098 	 * module name (from the modinfo_t) to ensure another module
1099 	 * with the same name doesn't already exist.  (There's no
1100 	 * guarantee the filename will match the module name, and the
1101 	 * dup-symbols check may not be sufficient.)
1102 	 */
1103 	if (mod->mod_source == MODULE_SOURCE_FILESYS) {
1104 		mod2 = module_lookup(mod->mod_info->mi_name);
1105 		if ( mod2 && mod2 != mod) {
1106 			module_error("module with name `%s' already loaded",
1107 			    mod2->mod_info->mi_name);
1108 			error = EEXIST;
1109 			goto fail;
1110 		}
1111 	}
1112 
1113 	/*
1114 	 * Block circular dependencies.
1115 	 */
1116 	TAILQ_FOREACH(mod2, pending, mod_chain) {
1117 		if (mod == mod2) {
1118 			continue;
1119 		}
1120 		if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) {
1121 			error = EDEADLK;
1122 			module_error("circular dependency detected for `%s'",
1123 			    mi->mi_name);
1124 			goto fail;
1125 		}
1126 	}
1127 
1128 	/*
1129 	 * Now try to load any requisite modules.
1130 	 */
1131 	if (mi->mi_required != NULL) {
1132 		for (s = mi->mi_required; *s != '\0'; s = p) {
1133 			if (*s == ',')
1134 				s++;
1135 			p = s;
1136 			while (*p != '\0' && *p != ',')
1137 				p++;
1138 			len = p - s + 1;
1139 			if (len >= MAXMODNAME) {
1140 				error = EINVAL;
1141 				module_error("required module name `%s' "
1142 				    "longer than %d", mi->mi_required,
1143 				    MAXMODNAME);
1144 				goto fail;
1145 			}
1146 			strlcpy(buf, s, len);
1147 			if (buf[0] == '\0')
1148 				break;
1149 			if (mod->mod_nrequired == MAXMODDEPS - 1) {
1150 				error = EINVAL;
1151 				module_error("too many required modules "
1152 				    "%d >= %d", mod->mod_nrequired,
1153 				    MAXMODDEPS - 1);
1154 				goto fail;
1155 			}
1156 			if (strcmp(buf, mi->mi_name) == 0) {
1157 				error = EDEADLK;
1158 				module_error("self-dependency detected for "
1159 				   "`%s'", mi->mi_name);
1160 				goto fail;
1161 			}
1162 			error = module_do_load(buf, true, flags, NULL,
1163 			    &mod2, MODULE_CLASS_ANY, true);
1164 			if (error != 0 && error != EEXIST) {
1165 				module_error("recursive load failed for `%s' "
1166 				    "(`%s' required), error %d", mi->mi_name,
1167 				    buf, error);
1168 				goto fail;
1169 			}
1170 			mod->mod_required[mod->mod_nrequired++] = mod2;
1171 		}
1172 	}
1173 
1174 	/*
1175 	 * We loaded all needed modules successfully: perform global
1176 	 * relocations and initialize.
1177 	 */
1178 	error = kobj_affix(mod->mod_kobj, mi->mi_name);
1179 	if (error != 0) {
1180 		/* Cannot touch 'mi' as the module is now gone. */
1181 		module_error("unable to affix module `%s', error %d", name,
1182 		    error);
1183 		goto fail2;
1184 	}
1185 
1186 	if (filedict) {
1187 		if (!module_merge_dicts(filedict, props)) {
1188 			module_error("module properties failed for %s", name);
1189 			error = EINVAL;
1190 			goto fail;
1191 		}
1192 	}
1193 	prev_active = module_active;
1194 	module_active = mod;
1195 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props);
1196 	module_active = prev_active;
1197 	if (filedict) {
1198 		prop_object_release(filedict);
1199 		filedict = NULL;
1200 	}
1201 	if (error != 0) {
1202 		module_error("modcmd function failed for `%s', error %d",
1203 		    mi->mi_name, error);
1204 		goto fail;
1205 	}
1206 
1207 	/*
1208 	 * If a recursive load already added a module with the same
1209 	 * name, abort.
1210 	 */
1211 	mod2 = module_lookup(mi->mi_name);
1212 	if (mod2 && mod2 != mod) {
1213 		module_error("recursive load causes duplicate module `%s'",
1214 		    mi->mi_name);
1215 		error = EEXIST;
1216 		goto fail1;
1217 	}
1218 
1219 	/*
1220 	 * Good, the module loaded successfully.  Put it onto the
1221 	 * list and add references to its requisite modules.
1222 	 */
1223 	TAILQ_REMOVE(pending, mod, mod_chain);
1224 	module_enqueue(mod);
1225 	if (modp != NULL) {
1226 		*modp = mod;
1227 	}
1228 	if (autoload && module_autotime > 0) {
1229 		/*
1230 		 * Arrange to try unloading the module after
1231 		 * a short delay unless auto-unload is disabled.
1232 		 */
1233 		mod->mod_autotime = time_second + module_autotime;
1234 		mod->mod_flags |= MODFLG_AUTO_LOADED;
1235 		module_thread_kick();
1236 	}
1237 	depth--;
1238 	module_print("module `%s' loaded successfully", mi->mi_name);
1239 	module_callback_load(mod);
1240 	return 0;
1241 
1242  fail1:
1243 	(*mi->mi_modcmd)(MODULE_CMD_FINI, NULL);
1244  fail:
1245 	kobj_unload(mod->mod_kobj);
1246  fail2:
1247 	if (filedict != NULL) {
1248 		prop_object_release(filedict);
1249 		filedict = NULL;
1250 	}
1251 	TAILQ_REMOVE(pending, mod, mod_chain);
1252 	module_free(mod);
1253 	depth--;
1254 	return error;
1255 }
1256 
1257 /*
1258  * module_do_unload:
1259  *
1260  *	Helper routine: do the dirty work of unloading a module.
1261  */
1262 static int
1263 module_do_unload(const char *name, bool load_requires_force)
1264 {
1265 	module_t *mod, *prev_active;
1266 	int error;
1267 	u_int i;
1268 
1269 	KASSERT(kernconfig_is_held());
1270 	KASSERT(name != NULL);
1271 
1272 	module_print("unload requested for '%s' (%s)", name,
1273 	    load_requires_force ? "TRUE" : "FALSE");
1274 	mod = module_lookup(name);
1275 	if (mod == NULL) {
1276 		module_error("module `%s' not found", name);
1277 		return ENOENT;
1278 	}
1279 	if (mod->mod_refcnt != 0) {
1280 		module_print("module `%s' busy (%d refs)", name,
1281 		    mod->mod_refcnt);
1282 		return EBUSY;
1283 	}
1284 
1285 	/*
1286 	 * Builtin secmodels are there to stay.
1287 	 */
1288 	if (mod->mod_source == MODULE_SOURCE_KERNEL &&
1289 	    mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) {
1290 		module_print("cannot unload built-in secmodel module `%s'",
1291 		    name);
1292 		return EPERM;
1293 	}
1294 
1295 	prev_active = module_active;
1296 	module_active = mod;
1297 	module_callback_unload(mod);
1298 	error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL);
1299 	module_active = prev_active;
1300 	if (error != 0) {
1301 		module_print("cannot unload module `%s' error=%d", name,
1302 		    error);
1303 		return error;
1304 	}
1305 	module_count--;
1306 	TAILQ_REMOVE(&module_list, mod, mod_chain);
1307 	for (i = 0; i < mod->mod_nrequired; i++) {
1308 		mod->mod_required[i]->mod_refcnt--;
1309 	}
1310 	module_print("unloaded module `%s'", name);
1311 	if (mod->mod_kobj != NULL) {
1312 		kobj_unload(mod->mod_kobj);
1313 	}
1314 	if (mod->mod_source == MODULE_SOURCE_KERNEL) {
1315 		mod->mod_nrequired = 0; /* will be re-parsed */
1316 		if (load_requires_force)
1317 			module_require_force(mod);
1318 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
1319 		module_builtinlist++;
1320 	} else {
1321 		module_free(mod);
1322 	}
1323 	module_gen++;
1324 
1325 	return 0;
1326 }
1327 
1328 /*
1329  * module_prime:
1330  *
1331  *	Push a module loaded by the bootloader onto our internal
1332  *	list.
1333  */
1334 int
1335 module_prime(const char *name, void *base, size_t size)
1336 {
1337 	__link_set_decl(modules, modinfo_t);
1338 	modinfo_t *const *mip;
1339 	module_t *mod;
1340 	int error;
1341 
1342 	/* Check for module name same as a built-in module */
1343 
1344 	__link_set_foreach(mip, modules) {
1345 		if (*mip == &module_dummy)
1346 			continue;
1347 		if (strcmp((*mip)->mi_name, name) == 0) {
1348 			module_error("module `%s' pushed by boot loader "
1349 			    "already exists", name);
1350 			return EEXIST;
1351 		}
1352 	}
1353 
1354 	/* Also eliminate duplicate boolist entries */
1355 
1356 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
1357 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1358 			module_error("duplicate bootlist entry for module "
1359 			    "`%s'", name);
1360 			return EEXIST;
1361 		}
1362 	}
1363 
1364 	mod = module_newmodule(MODULE_SOURCE_BOOT);
1365 	if (mod == NULL) {
1366 		return ENOMEM;
1367 	}
1368 
1369 	error = kobj_load_mem(&mod->mod_kobj, name, base, size);
1370 	if (error != 0) {
1371 		module_free(mod);
1372 		module_error("unable to load `%s' pushed by boot loader, "
1373 		    "error %d", name, error);
1374 		return error;
1375 	}
1376 	error = module_fetch_info(mod);
1377 	if (error != 0) {
1378 		kobj_unload(mod->mod_kobj);
1379 		module_free(mod);
1380 		module_error("unable to fetch_info for `%s' pushed by boot "
1381 		    "loader, error %d", name, error);
1382 		return error;
1383 	}
1384 
1385 	TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain);
1386 
1387 	return 0;
1388 }
1389 
1390 /*
1391  * module_fetch_into:
1392  *
1393  *	Fetch modinfo record from a loaded module.
1394  */
1395 static int
1396 module_fetch_info(module_t *mod)
1397 {
1398 	int error;
1399 	void *addr;
1400 	size_t size;
1401 
1402 	/*
1403 	 * Find module info record and check compatibility.
1404 	 */
1405 	error = kobj_find_section(mod->mod_kobj, "link_set_modules",
1406 	    &addr, &size);
1407 	if (error != 0) {
1408 		module_error("`link_set_modules' section not present, "
1409 		    "error %d", error);
1410 		return error;
1411 	}
1412 	if (size != sizeof(modinfo_t **)) {
1413 		module_error("`link_set_modules' section wrong size %zu != %zu",
1414 		    size, sizeof(modinfo_t **));
1415 		return ENOEXEC;
1416 	}
1417 	mod->mod_info = *(modinfo_t **)addr;
1418 
1419 	return 0;
1420 }
1421 
1422 /*
1423  * module_find_section:
1424  *
1425  *	Allows a module that is being initialized to look up a section
1426  *	within its ELF object.
1427  */
1428 int
1429 module_find_section(const char *name, void **addr, size_t *size)
1430 {
1431 
1432 	KASSERT(kernconfig_is_held());
1433 	KASSERT(module_active != NULL);
1434 
1435 	return kobj_find_section(module_active->mod_kobj, name, addr, size);
1436 }
1437 
1438 /*
1439  * module_thread:
1440  *
1441  *	Automatically unload modules.  We try once to unload autoloaded
1442  *	modules after module_autotime seconds.  If the system is under
1443  *	severe memory pressure, we'll try unloading all modules, else if
1444  *	module_autotime is zero, we don't try to unload, even if the
1445  *	module was previously scheduled for unload.
1446  */
1447 static void
1448 module_thread(void *cookie)
1449 {
1450 	module_t *mod, *next;
1451 	modinfo_t *mi;
1452 	int error;
1453 
1454 	for (;;) {
1455 		kernconfig_lock();
1456 		for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) {
1457 			next = TAILQ_NEXT(mod, mod_chain);
1458 
1459 			/* skip built-in modules */
1460 			if (mod->mod_source == MODULE_SOURCE_KERNEL)
1461 				continue;
1462 			/* skip modules that weren't auto-loaded */
1463 			if ((mod->mod_flags & MODFLG_AUTO_LOADED) == 0)
1464 				continue;
1465 
1466 			if (uvmexp.free < uvmexp.freemin) {
1467 				module_thread_ticks = hz;
1468 			} else if (module_autotime == 0 ||
1469 				   mod->mod_autotime == 0) {
1470 				continue;
1471 			} else if (time_second < mod->mod_autotime) {
1472 				module_thread_ticks = hz;
1473 			    	continue;
1474 			} else {
1475 				mod->mod_autotime = 0;
1476 			}
1477 
1478 			/*
1479 			 * If this module wants to avoid autounload then
1480 			 * skip it.  Some modules can ping-pong in and out
1481 			 * because their use is transient but often.
1482 			 * Example: exec_script.
1483 			 */
1484 			mi = mod->mod_info;
1485 			error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL);
1486 			if (error == 0 || error == ENOTTY) {
1487 				(void)module_do_unload(mi->mi_name, false);
1488 			} else
1489 				module_print("module `%s' declined to be "
1490 				    "auto-unloaded error=%d", mi->mi_name,
1491 				    error);
1492 		}
1493 		kernconfig_unlock();
1494 
1495 		mutex_enter(&module_thread_lock);
1496 		(void)cv_timedwait(&module_thread_cv, &module_thread_lock,
1497 		    module_thread_ticks);
1498 		module_thread_ticks = 0;
1499 		mutex_exit(&module_thread_lock);
1500 	}
1501 }
1502 
1503 /*
1504  * module_thread:
1505  *
1506  *	Kick the module thread into action, perhaps because the
1507  *	system is low on memory.
1508  */
1509 void
1510 module_thread_kick(void)
1511 {
1512 
1513 	mutex_enter(&module_thread_lock);
1514 	module_thread_ticks = hz;
1515 	cv_broadcast(&module_thread_cv);
1516 	mutex_exit(&module_thread_lock);
1517 }
1518 
1519 #ifdef DDB
1520 /*
1521  * module_whatis:
1522  *
1523  *	Helper routine for DDB.
1524  */
1525 void
1526 module_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1527 {
1528 	module_t *mod;
1529 	size_t msize;
1530 	vaddr_t maddr;
1531 
1532 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1533 		if (mod->mod_kobj == NULL) {
1534 			continue;
1535 		}
1536 		if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1537 			continue;
1538 		if (addr < maddr || addr >= maddr + msize) {
1539 			continue;
1540 		}
1541 		(*pr)("%p is %p+%zu, in kernel module `%s'\n",
1542 		    (void *)addr, (void *)maddr,
1543 		    (size_t)(addr - maddr), mod->mod_info->mi_name);
1544 	}
1545 }
1546 
1547 /*
1548  * module_print_list:
1549  *
1550  *	Helper routine for DDB.
1551  */
1552 void
1553 module_print_list(void (*pr)(const char *, ...))
1554 {
1555 	const char *src;
1556 	module_t *mod;
1557 	size_t msize;
1558 	vaddr_t maddr;
1559 
1560 	(*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE");
1561 
1562 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1563 		switch (mod->mod_source) {
1564 		case MODULE_SOURCE_KERNEL:
1565 			src = "builtin";
1566 			break;
1567 		case MODULE_SOURCE_FILESYS:
1568 			src = "filesys";
1569 			break;
1570 		case MODULE_SOURCE_BOOT:
1571 			src = "boot";
1572 			break;
1573 		default:
1574 			src = "unknown";
1575 			break;
1576 		}
1577 		if (mod->mod_kobj == NULL) {
1578 			maddr = 0;
1579 			msize = 0;
1580 		} else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1581 			continue;
1582 		(*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name,
1583 		    (long)maddr, (long)msize, src);
1584 	}
1585 }
1586 #endif	/* DDB */
1587 
1588 static bool
1589 module_merge_dicts(prop_dictionary_t existing_dict,
1590 		   const prop_dictionary_t new_dict)
1591 {
1592 	prop_dictionary_keysym_t props_keysym;
1593 	prop_object_iterator_t props_iter;
1594 	prop_object_t props_obj;
1595 	const char *props_key;
1596 	bool error;
1597 
1598 	if (new_dict == NULL) {			/* nothing to merge */
1599 		return true;
1600 	}
1601 
1602 	error = false;
1603 	props_iter = prop_dictionary_iterator(new_dict);
1604 	if (props_iter == NULL) {
1605 		return false;
1606 	}
1607 
1608 	while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) {
1609 		props_keysym = (prop_dictionary_keysym_t)props_obj;
1610 		props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym);
1611 		props_obj = prop_dictionary_get_keysym(new_dict, props_keysym);
1612 		if ((props_obj == NULL) || !prop_dictionary_set(existing_dict,
1613 		    props_key, props_obj)) {
1614 			error = true;
1615 			goto out;
1616 		}
1617 	}
1618 	error = false;
1619 
1620 out:
1621 	prop_object_iterator_release(props_iter);
1622 
1623 	return !error;
1624 }
1625 
1626 /*
1627  * module_specific_key_create:
1628  *
1629  *	Create a key for subsystem module-specific data.
1630  */
1631 specificdata_key_t
1632 module_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
1633 {
1634 
1635 	return specificdata_key_create(module_specificdata_domain, keyp, dtor);
1636 }
1637 
1638 /*
1639  * module_specific_key_delete:
1640  *
1641  *	Delete a key for subsystem module-specific data.
1642  */
1643 void
1644 module_specific_key_delete(specificdata_key_t key)
1645 {
1646 
1647 	return specificdata_key_delete(module_specificdata_domain, key);
1648 }
1649 
1650 /*
1651  * module_getspecific:
1652  *
1653  *	Return module-specific data corresponding to the specified key.
1654  */
1655 void *
1656 module_getspecific(module_t *mod, specificdata_key_t key)
1657 {
1658 
1659 	return specificdata_getspecific(module_specificdata_domain,
1660 	    &mod->mod_sdref, key);
1661 }
1662 
1663 /*
1664  * module_setspecific:
1665  *
1666  *	Set module-specific data corresponding to the specified key.
1667  */
1668 void
1669 module_setspecific(module_t *mod, specificdata_key_t key, void *data)
1670 {
1671 
1672 	specificdata_setspecific(module_specificdata_domain,
1673 	    &mod->mod_sdref, key, data);
1674 }
1675 
1676 /*
1677  * module_register_callbacks:
1678  *
1679  *	Register a new set of callbacks to be called on module load/unload.
1680  *	Call the load callback on each existing module.
1681  *	Return an opaque handle for unregistering these later.
1682  */
1683 void *
1684 module_register_callbacks(void (*load)(struct module *),
1685     void (*unload)(struct module *))
1686 {
1687 	struct module_callbacks *modcb;
1688 	struct module *mod;
1689 
1690 	modcb = kmem_alloc(sizeof(*modcb), KM_SLEEP);
1691 	modcb->modcb_load = load;
1692 	modcb->modcb_unload = unload;
1693 
1694 	kernconfig_lock();
1695 	TAILQ_INSERT_TAIL(&modcblist, modcb, modcb_list);
1696 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1697 		load(mod);
1698 	kernconfig_unlock();
1699 
1700 	return modcb;
1701 }
1702 
1703 /*
1704  * module_unregister_callbacks:
1705  *
1706  *	Unregister a previously-registered set of module load/unload callbacks.
1707  *	Call the unload callback on each existing module.
1708  */
1709 void
1710 module_unregister_callbacks(void *opaque)
1711 {
1712 	struct module_callbacks *modcb;
1713 	struct module *mod;
1714 
1715 	modcb = opaque;
1716 	kernconfig_lock();
1717 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1718 		modcb->modcb_unload(mod);
1719 	TAILQ_REMOVE(&modcblist, modcb, modcb_list);
1720 	kernconfig_unlock();
1721 	kmem_free(modcb, sizeof(*modcb));
1722 }
1723 
1724 /*
1725  * module_callback_load:
1726  *
1727  *	Helper routine: call all load callbacks on a module being loaded.
1728  */
1729 static void
1730 module_callback_load(struct module *mod)
1731 {
1732 	struct module_callbacks *modcb;
1733 
1734 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1735 		modcb->modcb_load(mod);
1736 	}
1737 }
1738 
1739 /*
1740  * module_callback_unload:
1741  *
1742  *	Helper routine: call all unload callbacks on a module being unloaded.
1743  */
1744 static void
1745 module_callback_unload(struct module *mod)
1746 {
1747 	struct module_callbacks *modcb;
1748 
1749 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1750 		modcb->modcb_unload(mod);
1751 	}
1752 }
1753