xref: /netbsd-src/sys/kern/kern_module.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /*	$NetBSD: kern_module.c,v 1.138 2019/08/08 18:08:41 pgoyette 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 1.138 2019/08/08 18:08:41 pgoyette 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 	if (mod->mod_required)
247 		kmem_free(mod->mod_required, mod->mod_arequired *
248 		    sizeof(module_t *));
249 	kmem_free(mod, sizeof(*mod));
250 }
251 
252 /*
253  * Require the -f (force) flag to load a module
254  */
255 static void
256 module_require_force(struct module *mod)
257 {
258 	SET(mod->mod_flags, MODFLG_MUST_FORCE);
259 }
260 
261 /*
262  * Add modules to the builtin list.  This can done at boottime or
263  * at runtime if the module is linked into the kernel with an
264  * external linker.  All or none of the input will be handled.
265  * Optionally, the modules can be initialized.  If they are not
266  * initialized, module_init_class() or module_load() can be used
267  * later, but these are not guaranteed to give atomic results.
268  */
269 int
270 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init)
271 {
272 	struct module **modp = NULL, *mod_iter;
273 	int rv = 0, i, mipskip;
274 
275 	if (init) {
276 		rv = kauth_authorize_system(kauth_cred_get(),
277 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD,
278 		    (void *)(uintptr_t)1, NULL);
279 		if (rv) {
280 			return rv;
281 		}
282 	}
283 
284 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
285 		if (mip[i] == &module_dummy) {
286 			KASSERT(nmodinfo > 0);
287 			nmodinfo--;
288 		}
289 	}
290 	if (nmodinfo == 0)
291 		return 0;
292 
293 	modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP);
294 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
295 		if (mip[i+mipskip] == &module_dummy) {
296 			mipskip++;
297 			continue;
298 		}
299 		modp[i] = module_newmodule(MODULE_SOURCE_KERNEL);
300 		modp[i]->mod_info = mip[i+mipskip];
301 	}
302 	kernconfig_lock();
303 
304 	/* do this in three stages for error recovery and atomicity */
305 
306 	/* first check for presence */
307 	for (i = 0; i < nmodinfo; i++) {
308 		TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) {
309 			if (strcmp(mod_iter->mod_info->mi_name,
310 			    modp[i]->mod_info->mi_name) == 0)
311 				break;
312 		}
313 		if (mod_iter) {
314 			rv = EEXIST;
315 			goto out;
316 		}
317 
318 		if (module_lookup(modp[i]->mod_info->mi_name) != NULL) {
319 			rv = EEXIST;
320 			goto out;
321 		}
322 	}
323 
324 	/* then add to list */
325 	for (i = 0; i < nmodinfo; i++) {
326 		TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain);
327 		module_builtinlist++;
328 	}
329 
330 	/* finally, init (if required) */
331 	if (init) {
332 		for (i = 0; i < nmodinfo; i++) {
333 			rv = module_do_builtin(modp[i],
334 			    modp[i]->mod_info->mi_name, NULL, NULL);
335 			/* throw in the towel, recovery hard & not worth it */
336 			if (rv)
337 				panic("%s: builtin module \"%s\" init failed:"
338 				    " %d", __func__,
339 				    modp[i]->mod_info->mi_name, rv);
340 		}
341 	}
342 
343  out:
344 	kernconfig_unlock();
345 	if (rv != 0) {
346 		for (i = 0; i < nmodinfo; i++) {
347 			if (modp[i])
348 				module_free(modp[i]);
349 		}
350 	}
351 	kmem_free(modp, sizeof(*modp) * nmodinfo);
352 	return rv;
353 }
354 
355 /*
356  * Optionally fini and remove builtin module from the kernel.
357  * Note: the module will now be unreachable except via mi && builtin_add.
358  */
359 int
360 module_builtin_remove(modinfo_t *mi, bool fini)
361 {
362 	struct module *mod;
363 	int rv = 0;
364 
365 	if (fini) {
366 		rv = kauth_authorize_system(kauth_cred_get(),
367 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD,
368 		    NULL, NULL);
369 		if (rv)
370 			return rv;
371 
372 		kernconfig_lock();
373 		rv = module_do_unload(mi->mi_name, true);
374 		if (rv) {
375 			goto out;
376 		}
377 	} else {
378 		kernconfig_lock();
379 	}
380 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
381 		if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0)
382 			break;
383 	}
384 	if (mod) {
385 		TAILQ_REMOVE(&module_builtins, mod, mod_chain);
386 		module_builtinlist--;
387 	} else {
388 		KASSERT(fini == false);
389 		rv = ENOENT;
390 	}
391 
392  out:
393 	kernconfig_unlock();
394 	return rv;
395 }
396 
397 /*
398  * module_init:
399  *
400  *	Initialize the module subsystem.
401  */
402 void
403 module_init(void)
404 {
405 	__link_set_decl(modules, modinfo_t);
406 	extern struct vm_map *module_map;
407 	modinfo_t *const *mip;
408 	int rv;
409 
410 	if (module_map == NULL) {
411 		module_map = kernel_map;
412 	}
413 	cv_init(&module_thread_cv, "mod_unld");
414 	mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE);
415 	TAILQ_INIT(&modcblist);
416 
417 #ifdef MODULAR	/* XXX */
418 	module_init_md();
419 #endif
420 
421 	if (!module_machine)
422 		module_machine = machine;
423 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
424 	snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules",
425 	    module_machine, osrelease);
426 #else						/* release */
427 	snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules",
428 	    module_machine, __NetBSD_Version__ / 100000000,
429 	    __NetBSD_Version__ / 1000000 % 100);
430 #endif
431 
432 	module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
433 	    module_listener_cb, NULL);
434 
435 	__link_set_foreach(mip, modules) {
436 		if ((rv = module_builtin_add(mip, 1, false)) != 0)
437 			module_error("builtin %s failed: %d\n",
438 			    (*mip)->mi_name, rv);
439 	}
440 
441 	sysctl_module_setup();
442 	module_specificdata_domain = specificdata_domain_create();
443 
444 	module_netbsd = module_newmodule(MODULE_SOURCE_KERNEL);
445 	module_netbsd->mod_refcnt = 1;
446 	module_netbsd->mod_info = &module_netbsd_modinfo;
447 }
448 
449 /*
450  * module_start_unload_thread:
451  *
452  *	Start the auto unload kthread.
453  */
454 void
455 module_start_unload_thread(void)
456 {
457 	int error;
458 
459 	error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread,
460 	    NULL, NULL, "modunload");
461 	if (error != 0)
462 		panic("%s: %d", __func__, error);
463 }
464 
465 /*
466  * module_builtin_require_force
467  *
468  * Require MODCTL_MUST_FORCE to load any built-in modules that have
469  * not yet been initialized
470  */
471 void
472 module_builtin_require_force(void)
473 {
474 	module_t *mod;
475 
476 	kernconfig_lock();
477 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
478 		module_require_force(mod);
479 	}
480 	kernconfig_unlock();
481 }
482 
483 static struct sysctllog *module_sysctllog;
484 
485 static int
486 sysctl_module_autotime(SYSCTLFN_ARGS)
487 {
488 	struct sysctlnode node;
489 	int t, error;
490 
491 	t = *(int *)rnode->sysctl_data;
492 
493 	node = *rnode;
494 	node.sysctl_data = &t;
495 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
496 	if (error || newp == NULL)
497 		return (error);
498 
499 	if (t < 0)
500 		return (EINVAL);
501 
502 	*(int *)rnode->sysctl_data = t;
503 	return (0);
504 }
505 
506 static void
507 sysctl_module_setup(void)
508 {
509 	const struct sysctlnode *node = NULL;
510 
511 	sysctl_createv(&module_sysctllog, 0, NULL, &node,
512 		CTLFLAG_PERMANENT,
513 		CTLTYPE_NODE, "module",
514 		SYSCTL_DESCR("Module options"),
515 		NULL, 0, NULL, 0,
516 		CTL_KERN, CTL_CREATE, CTL_EOL);
517 
518 	if (node == NULL)
519 		return;
520 
521 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
522 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
523 		CTLTYPE_BOOL, "autoload",
524 		SYSCTL_DESCR("Enable automatic load of modules"),
525 		NULL, 0, &module_autoload_on, 0,
526 		CTL_CREATE, CTL_EOL);
527 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
528 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
529 		CTLTYPE_BOOL, "verbose",
530 		SYSCTL_DESCR("Enable verbose output"),
531 		NULL, 0, &module_verbose_on, 0,
532 		CTL_CREATE, CTL_EOL);
533 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
534 		CTLFLAG_PERMANENT | CTLFLAG_READONLY,
535 		CTLTYPE_STRING, "path",
536 		SYSCTL_DESCR("Default module load path"),
537 		NULL, 0, module_base, 0,
538 		CTL_CREATE, CTL_EOL);
539 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
540 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
541 		CTLTYPE_INT, "autotime",
542 		SYSCTL_DESCR("Auto-unload delay"),
543 		sysctl_module_autotime, 0, &module_autotime, 0,
544 		CTL_CREATE, CTL_EOL);
545 }
546 
547 /*
548  * module_init_class:
549  *
550  *	Initialize all built-in and pre-loaded modules of the
551  *	specified class.
552  */
553 void
554 module_init_class(modclass_t modclass)
555 {
556 	TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail);
557 	module_t *mod;
558 	modinfo_t *mi;
559 
560 	kernconfig_lock();
561 	/*
562 	 * Builtins first.  These will not depend on pre-loaded modules
563 	 * (because the kernel would not link).
564 	 */
565 	do {
566 		TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
567 			mi = mod->mod_info;
568 			if (!MODULE_CLASS_MATCH(mi, modclass))
569 				continue;
570 			/*
571 			 * If initializing a builtin module fails, don't try
572 			 * to load it again.  But keep it around and queue it
573 			 * on the builtins list after we're done with module
574 			 * init.  Don't set it to MODFLG_MUST_FORCE in case a
575 			 * future attempt to initialize can be successful.
576 			 * (If the module has previously been set to
577 			 * MODFLG_MUST_FORCE, don't try to override that!)
578 			 */
579 			if (ISSET(mod->mod_flags, MODFLG_MUST_FORCE) ||
580 			    module_do_builtin(mod, mi->mi_name, NULL,
581 			    NULL) != 0) {
582 				TAILQ_REMOVE(&module_builtins, mod, mod_chain);
583 				TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain);
584 			}
585 			break;
586 		}
587 	} while (mod != NULL);
588 
589 	/*
590 	 * Now preloaded modules.  These will be pulled off the
591 	 * list as we call module_do_load();
592 	 */
593 	do {
594 		TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
595 			mi = mod->mod_info;
596 			if (!MODULE_CLASS_MATCH(mi, modclass))
597 				continue;
598 			module_do_load(mi->mi_name, false, 0, NULL, NULL,
599 			    modclass, false);
600 			break;
601 		}
602 	} while (mod != NULL);
603 
604 	/* return failed builtin modules to builtin list */
605 	while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) {
606 		TAILQ_REMOVE(&bi_fail, mod, mod_chain);
607 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
608 	}
609 
610 	kernconfig_unlock();
611 }
612 
613 /*
614  * module_compatible:
615  *
616  *	Return true if the two supplied kernel versions are said to
617  *	have the same binary interface for kernel code.  The entire
618  *	version is signficant for the development tree (-current),
619  *	major and minor versions are significant for official
620  *	releases of the system.
621  */
622 bool
623 module_compatible(int v1, int v2)
624 {
625 
626 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
627 	return v1 == v2;
628 #else						/* release */
629 	return abs(v1 - v2) < 10000;
630 #endif
631 }
632 
633 /*
634  * module_load:
635  *
636  *	Load a single module from the file system.
637  */
638 int
639 module_load(const char *filename, int flags, prop_dictionary_t props,
640 	    modclass_t modclass)
641 {
642 	module_t *mod;
643 	int error;
644 
645 	/* Test if we already have the module loaded before
646 	 * authorizing so we have the opportunity to return EEXIST. */
647 	kernconfig_lock();
648 	mod = module_lookup(filename);
649 	if (mod != NULL) {
650 		module_print("%s module `%s' already loaded",
651 		    "requested", filename);
652 		error = EEXIST;
653 		goto out;
654 	}
655 
656 	/* Authorize. */
657 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
658 	    0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL);
659 	if (error != 0)
660 		goto out;
661 
662 	error = module_do_load(filename, false, flags, props, NULL, modclass,
663 	    false);
664 
665 out:
666 	kernconfig_unlock();
667 	return error;
668 }
669 
670 /*
671  * module_autoload:
672  *
673  *	Load a single module from the file system, system initiated.
674  */
675 int
676 module_autoload(const char *filename, modclass_t modclass)
677 {
678 	int error;
679 
680 	kernconfig_lock();
681 
682 	/* Nothing if the user has disabled it. */
683 	if (!module_autoload_on) {
684 		kernconfig_unlock();
685 		return EPERM;
686 	}
687 
688         /* Disallow path separators and magic symlinks. */
689         if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL ||
690             strchr(filename, '.') != NULL) {
691 		kernconfig_unlock();
692         	return EPERM;
693 	}
694 
695 	/* Authorize. */
696 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
697 	    0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL);
698 
699 	if (error == 0)
700 		error = module_do_load(filename, false, 0, NULL, NULL, modclass,
701 		    true);
702 
703 	kernconfig_unlock();
704 	return error;
705 }
706 
707 /*
708  * module_unload:
709  *
710  *	Find and unload a module by name.
711  */
712 int
713 module_unload(const char *name)
714 {
715 	int error;
716 
717 	/* Authorize. */
718 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
719 	    0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL);
720 	if (error != 0) {
721 		return error;
722 	}
723 
724 	kernconfig_lock();
725 	error = module_do_unload(name, true);
726 	kernconfig_unlock();
727 
728 	return error;
729 }
730 
731 /*
732  * module_lookup:
733  *
734  *	Look up a module by name.
735  */
736 module_t *
737 module_lookup(const char *name)
738 {
739 	module_t *mod;
740 
741 	KASSERT(kernconfig_is_held());
742 
743 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
744 		if (strcmp(mod->mod_info->mi_name, name) == 0)
745 			break;
746 	}
747 
748 	return mod;
749 }
750 
751 /*
752  * module_hold:
753  *
754  *	Add a single reference to a module.  It's the caller's
755  *	responsibility to ensure that the reference is dropped
756  *	later.
757  */
758 void
759 module_hold(module_t *mod)
760 {
761 
762 	kernconfig_lock();
763 	mod->mod_refcnt++;
764 	kernconfig_unlock();
765 }
766 
767 /*
768  * module_rele:
769  *
770  *	Release a reference acquired with module_hold().
771  */
772 void
773 module_rele(module_t *mod)
774 {
775 
776 	kernconfig_lock();
777 	KASSERT(mod->mod_refcnt > 0);
778 	mod->mod_refcnt--;
779 	kernconfig_unlock();
780 }
781 
782 /*
783  * module_enqueue:
784  *
785  *	Put a module onto the global list and update counters.
786  */
787 void
788 module_enqueue(module_t *mod)
789 {
790 	int i;
791 
792 	KASSERT(kernconfig_is_held());
793 
794 	/*
795 	 * Put new entry at the head of the queue so autounload can unload
796 	 * requisite modules with only one pass through the queue.
797 	 */
798 	TAILQ_INSERT_HEAD(&module_list, mod, mod_chain);
799 	if (mod->mod_nrequired) {
800 
801 		/* Add references to the requisite modules. */
802 		for (i = 0; i < mod->mod_nrequired; i++) {
803 			KASSERT((*mod->mod_required)[i] != NULL);
804 			(*mod->mod_required)[i]->mod_refcnt++;
805 		}
806 	}
807 	module_count++;
808 	module_gen++;
809 }
810 
811 /*
812  * Our array of required module pointers starts with zero entries.  If we
813  * need to add a new entry, and the list is already full, we reallocate a
814  * larger array, adding MAXMODDEPS entries.
815  */
816 static void
817 alloc_required(module_t *mod)
818 {
819 	module_t *(*new)[], *(*old)[];
820 	int areq;
821 	int i;
822 
823 	if (mod->mod_nrequired >= mod->mod_arequired) {
824 		areq = mod->mod_arequired + MAXMODDEPS;
825 		old = mod->mod_required;
826 		new = kmem_zalloc(areq * sizeof(module_t *), KM_SLEEP);
827 		for (i = 0; i < mod->mod_arequired; i++)
828 			(*new)[i] = (*old)[i];
829 		mod->mod_required = new;
830 		if (old)
831 			kmem_free(old, mod->mod_arequired * sizeof(module_t *));
832 		mod->mod_arequired = areq;
833 	}
834 }
835 
836 /*
837  * module_do_builtin:
838  *
839  *	Initialize a module from the list of modules that are
840  *	already linked into the kernel.
841  */
842 static int
843 module_do_builtin(const module_t *pmod, const char *name, module_t **modp,
844     prop_dictionary_t props)
845 {
846 	const char *p, *s;
847 	char buf[MAXMODNAME];
848 	modinfo_t *mi = NULL;
849 	module_t *mod, *mod2, *mod_loaded, *prev_active;
850 	size_t len;
851 	int error;
852 
853 	KASSERT(kernconfig_is_held());
854 
855 	/*
856 	 * Search the list to see if we have a module by this name.
857 	 */
858 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
859 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
860 			mi = mod->mod_info;
861 			break;
862 		}
863 	}
864 
865 	/*
866 	 * Check to see if already loaded.  This might happen if we
867 	 * were already loaded as a dependency.
868 	 */
869 	if ((mod_loaded = module_lookup(name)) != NULL) {
870 		KASSERT(mod == NULL);
871 		if (modp)
872 			*modp = mod_loaded;
873 		return 0;
874 	}
875 
876 	/* Note! This is from TAILQ, not immediate above */
877 	if (mi == NULL) {
878 		/*
879 		 * XXX: We'd like to panic here, but currently in some
880 		 * cases (such as nfsserver + nfs), the dependee can be
881 		 * succesfully linked without the dependencies.
882 		 */
883 		module_error("built-in module %s can't find builtin "
884 		    "dependency `%s'", pmod->mod_info->mi_name, name);
885 		return ENOENT;
886 	}
887 
888 	/*
889 	 * Initialize pre-requisites.
890 	 */
891 	KASSERT(mod->mod_required == NULL);
892 	KASSERT(mod->mod_arequired == 0);
893 	KASSERT(mod->mod_nrequired == 0);
894 	if (mi->mi_required != NULL) {
895 		for (s = mi->mi_required; *s != '\0'; s = p) {
896 			if (*s == ',')
897 				s++;
898 			p = s;
899 			while (*p != '\0' && *p != ',')
900 				p++;
901 			len = uimin(p - s + 1, sizeof(buf));
902 			strlcpy(buf, s, len);
903 			if (buf[0] == '\0')
904 				break;
905 			alloc_required(mod);
906 			error = module_do_builtin(mod, buf, &mod2, NULL);
907 			if (error != 0) {
908 				module_error("built-in module %s prerequisite "
909 				    "%s failed, error %d", name, buf, error);
910 				goto fail;
911 			}
912 			(*mod->mod_required)[mod->mod_nrequired++] = mod2;
913 		}
914 	}
915 
916 	/*
917 	 * Try to initialize the module.
918 	 */
919 	prev_active = module_active;
920 	module_active = mod;
921 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props);
922 	module_active = prev_active;
923 	if (error != 0) {
924 		module_error("built-in module %s failed its MODULE_CMD_INIT, "
925 		    "error %d", mi->mi_name, error);
926 		goto fail;
927 	}
928 
929 	/* load always succeeds after this point */
930 
931 	TAILQ_REMOVE(&module_builtins, mod, mod_chain);
932 	module_builtinlist--;
933 	if (modp != NULL) {
934 		*modp = mod;
935 	}
936 	module_enqueue(mod);
937 	return 0;
938 
939  fail:
940 	if (mod->mod_required)
941 		kmem_free(mod->mod_required, mod->mod_arequired *
942 		    sizeof(module_t *));
943 	mod->mod_arequired = 0;
944 	mod->mod_nrequired = 0;
945 	mod->mod_required = NULL;
946 	return error;
947 }
948 
949 /*
950  * module_load_sysctl
951  *
952  * Check to see if a non-builtin module has any SYSCTL_SETUP() routine(s)
953  * registered.  If so, call it (them).
954  */
955 
956 static void
957 module_load_sysctl(module_t *mod)
958 {
959 	void (**ls_funcp)(struct sysctllog **);
960 	void *ls_start;
961 	size_t ls_size, count;
962 	int error;
963 
964 	/*
965 	 * Built-in modules don't have a mod_kobj so we cannot search
966 	 * for their link_set_sysctl_funcs
967 	 */
968 	if (mod->mod_source == MODULE_SOURCE_KERNEL)
969 		return;
970 
971 	error = kobj_find_section(mod->mod_kobj, "link_set_sysctl_funcs",
972 	    &ls_start, &ls_size);
973 	if (error == 0) {
974 		count = ls_size / sizeof(ls_start);
975 		ls_funcp = ls_start;
976 		while (count--) {
977 			(**ls_funcp)(&mod->mod_sysctllog);
978 			ls_funcp++;
979 		}
980 	}
981 	else
982 		error = 0;	/* no setup funcs registered */
983 }
984 
985 /*
986  * module_do_load:
987  *
988  *	Helper routine: load a module from the file system, or one
989  *	pushed by the boot loader.
990  */
991 static int
992 module_do_load(const char *name, bool isdep, int flags,
993 	       prop_dictionary_t props, module_t **modp, modclass_t modclass,
994 	       bool autoload)
995 {
996 	/* The pending list for this level of recursion */
997 	TAILQ_HEAD(pending_t, module);
998 	struct pending_t *pending;
999 	struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending);
1000 
1001 	/* The stack of pending lists */
1002 	static SLIST_HEAD(pend_head, pend_entry) pend_stack =
1003 		SLIST_HEAD_INITIALIZER(pend_stack);
1004 	struct pend_entry {
1005 		SLIST_ENTRY(pend_entry) pe_entry;
1006 		struct pending_t *pe_pending;
1007 	} my_pend_entry;
1008 
1009 	modinfo_t *mi;
1010 	module_t *mod, *mod2, *prev_active;
1011 	prop_dictionary_t filedict;
1012 	char buf[MAXMODNAME];
1013 	const char *s, *p;
1014 	int error;
1015 	size_t len;
1016 
1017 	KASSERT(kernconfig_is_held());
1018 
1019 	filedict = NULL;
1020 	error = 0;
1021 
1022 	/*
1023 	 * Set up the pending list for this entry.  If this is an
1024 	 * internal entry (for a dependency), then use the same list
1025 	 * as for the outer call;  otherwise, it's an external entry
1026 	 * (possibly recursive, ie a module's xxx_modcmd(init, ...)
1027 	 * routine called us), so use the locally allocated list.  In
1028 	 * either case, add it to our stack.
1029 	 */
1030 	if (isdep) {
1031 		KASSERT(SLIST_FIRST(&pend_stack) != NULL);
1032 		pending = SLIST_FIRST(&pend_stack)->pe_pending;
1033 	} else
1034 		pending = &new_pending;
1035 	my_pend_entry.pe_pending = pending;
1036 	SLIST_INSERT_HEAD(&pend_stack, &my_pend_entry, pe_entry);
1037 
1038 	/*
1039 	 * Search the list of disabled builtins first.
1040 	 */
1041 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
1042 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1043 			break;
1044 		}
1045 	}
1046 	if (mod) {
1047 		if (ISSET(mod->mod_flags, MODFLG_MUST_FORCE) &&
1048 		    !ISSET(flags, MODCTL_LOAD_FORCE)) {
1049 			if (!autoload) {
1050 				module_error("use -f to reinstate "
1051 				    "builtin module `%s'", name);
1052 			}
1053 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1054 			return EPERM;
1055 		} else {
1056 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1057 			error = module_do_builtin(mod, name, modp, props);
1058 			return error;
1059 		}
1060 	}
1061 
1062 	/*
1063 	 * Load the module and link.  Before going to the file system,
1064 	 * scan the list of modules loaded by the boot loader.
1065 	 */
1066 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
1067 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1068 			TAILQ_REMOVE(&module_bootlist, mod, mod_chain);
1069 			break;
1070 		}
1071 	}
1072 	if (mod != NULL) {
1073 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1074 	} else {
1075 		/*
1076 		 * Check to see if module is already present.
1077 		 */
1078 		mod = module_lookup(name);
1079 		if (mod != NULL) {
1080 			if (modp != NULL) {
1081 				*modp = mod;
1082 			}
1083 			module_print("%s module `%s' already loaded",
1084 			    isdep ? "dependent" : "requested", name);
1085 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1086 			return EEXIST;
1087 		}
1088 
1089 		mod = module_newmodule(MODULE_SOURCE_FILESYS);
1090 		if (mod == NULL) {
1091 			module_error("out of memory for `%s'", name);
1092 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1093 			return ENOMEM;
1094 		}
1095 
1096 		error = module_load_vfs_vec(name, flags, autoload, mod,
1097 					    &filedict);
1098 		if (error != 0) {
1099 #ifdef DEBUG
1100 			/*
1101 			 * The exec class of modules contains a list of
1102 			 * modules that is the union of all the modules
1103 			 * available for each architecture, so we don't
1104 			 * print an error if they are missing.
1105 			 */
1106 			if ((modclass != MODULE_CLASS_EXEC || error != ENOENT)
1107 			    && root_device != NULL)
1108 				module_error("vfs load failed for `%s', "
1109 				    "error %d", name, error);
1110 #endif
1111 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1112 			module_free(mod);
1113 			return error;
1114 		}
1115 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1116 
1117 		error = module_fetch_info(mod);
1118 		if (error != 0) {
1119 			module_error("cannot fetch info for `%s', error %d",
1120 			    name, error);
1121 			goto fail;
1122 		}
1123 	}
1124 
1125 	/*
1126 	 * Check compatibility.
1127 	 */
1128 	mi = mod->mod_info;
1129 	if (strnlen(mi->mi_name, MAXMODNAME) >= MAXMODNAME) {
1130 		error = EINVAL;
1131 		module_error("module name `%s' longer than %d", mi->mi_name,
1132 		    MAXMODNAME);
1133 		goto fail;
1134 	}
1135 	if (mi->mi_class <= MODULE_CLASS_ANY ||
1136 	    mi->mi_class >= MODULE_CLASS_MAX) {
1137 		error = EINVAL;
1138 		module_error("module `%s' has invalid class %d",
1139 		    mi->mi_name, mi->mi_class);
1140 		    goto fail;
1141 	}
1142 	if (!module_compatible(mi->mi_version, __NetBSD_Version__)) {
1143 		module_error("module `%s' built for `%d', system `%d'",
1144 		    mi->mi_name, mi->mi_version, __NetBSD_Version__);
1145 		if (ISSET(flags, MODCTL_LOAD_FORCE)) {
1146 			module_error("forced load, system may be unstable");
1147 		} else {
1148 			error = EPROGMISMATCH;
1149 			goto fail;
1150 		}
1151 	}
1152 
1153 	/*
1154 	 * If a specific kind of module was requested, ensure that we have
1155 	 * a match.
1156 	 */
1157 	if (!MODULE_CLASS_MATCH(mi, modclass)) {
1158 		module_incompat(mi, modclass);
1159 		error = ENOENT;
1160 		goto fail;
1161 	}
1162 
1163 	/*
1164 	 * If loading a dependency, `name' is a plain module name.
1165 	 * The name must match.
1166 	 */
1167 	if (isdep && strcmp(mi->mi_name, name) != 0) {
1168 		module_error("dependency name mismatch (`%s' != `%s')",
1169 		    name, mi->mi_name);
1170 		error = ENOENT;
1171 		goto fail;
1172 	}
1173 
1174 	/*
1175 	 * If we loaded a module from the filesystem, check the actual
1176 	 * module name (from the modinfo_t) to ensure another module
1177 	 * with the same name doesn't already exist.  (There's no
1178 	 * guarantee the filename will match the module name, and the
1179 	 * dup-symbols check may not be sufficient.)
1180 	 */
1181 	if (mod->mod_source == MODULE_SOURCE_FILESYS) {
1182 		mod2 = module_lookup(mod->mod_info->mi_name);
1183 		if ( mod2 && mod2 != mod) {
1184 			module_error("module with name `%s' already loaded",
1185 			    mod2->mod_info->mi_name);
1186 			error = EEXIST;
1187 			if (modp != NULL)
1188 				*modp = mod2;
1189 			goto fail;
1190 		}
1191 	}
1192 
1193 	/*
1194 	 * Block circular dependencies.
1195 	 */
1196 	TAILQ_FOREACH(mod2, pending, mod_chain) {
1197 		if (mod == mod2) {
1198 			continue;
1199 		}
1200 		if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) {
1201 			error = EDEADLK;
1202 			module_error("circular dependency detected for `%s'",
1203 			    mi->mi_name);
1204 			goto fail;
1205 		}
1206 	}
1207 
1208 	/*
1209 	 * Now try to load any requisite modules.
1210 	 */
1211 	if (mi->mi_required != NULL) {
1212 		mod->mod_arequired = 0;
1213 		for (s = mi->mi_required; *s != '\0'; s = p) {
1214 			if (*s == ',')
1215 				s++;
1216 			p = s;
1217 			while (*p != '\0' && *p != ',')
1218 				p++;
1219 			len = p - s + 1;
1220 			if (len >= MAXMODNAME) {
1221 				error = EINVAL;
1222 				module_error("required module name `%s' "
1223 				    "longer than %d", mi->mi_required,
1224 				    MAXMODNAME);
1225 				goto fail;
1226 			}
1227 			strlcpy(buf, s, len);
1228 			if (buf[0] == '\0')
1229 				break;
1230 			alloc_required(mod);
1231 			if (strcmp(buf, mi->mi_name) == 0) {
1232 				error = EDEADLK;
1233 				module_error("self-dependency detected for "
1234 				   "`%s'", mi->mi_name);
1235 				goto fail;
1236 			}
1237 			error = module_do_load(buf, true, flags, NULL,
1238 			    &mod2, MODULE_CLASS_ANY, true);
1239 			if (error != 0 && error != EEXIST) {
1240 				module_error("recursive load failed for `%s' "
1241 				    "(`%s' required), error %d", mi->mi_name,
1242 				    buf, error);
1243 				goto fail;
1244 			}
1245 			(*mod->mod_required)[mod->mod_nrequired++] = mod2;
1246 		}
1247 	}
1248 
1249 	/*
1250 	 * We loaded all needed modules successfully: perform global
1251 	 * relocations and initialize.
1252 	 */
1253 	{
1254 		char xname[MAXMODNAME];
1255 
1256 		/*
1257 		 * In case of error the entire module is gone, so we
1258 		 * need to save its name for possible error report.
1259 		 */
1260 
1261 		strlcpy(xname, mi->mi_name, MAXMODNAME);
1262 		error = kobj_affix(mod->mod_kobj, mi->mi_name);
1263 		if (error != 0) {
1264 			module_error("unable to affix module `%s', error %d",
1265 			    xname, error);
1266 			goto fail2;
1267 		}
1268 	}
1269 
1270 	if (filedict) {
1271 		if (!module_merge_dicts(filedict, props)) {
1272 			module_error("module properties failed for %s", name);
1273 			error = EINVAL;
1274 			goto fail;
1275 		}
1276 	}
1277 
1278 	prev_active = module_active;
1279 	module_active = mod;
1280 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props);
1281 	module_active = prev_active;
1282 	if (filedict) {
1283 		prop_object_release(filedict);
1284 		filedict = NULL;
1285 	}
1286 	if (error != 0) {
1287 		module_error("modcmd(CMD_INIT) failed for `%s', error %d",
1288 		    mi->mi_name, error);
1289 		goto fail;
1290 	}
1291 
1292 	/*
1293 	 * If a recursive load already added a module with the same
1294 	 * name, abort.
1295 	 */
1296 	mod2 = module_lookup(mi->mi_name);
1297 	if (mod2 && mod2 != mod) {
1298 		module_error("recursive load causes duplicate module `%s'",
1299 		    mi->mi_name);
1300 		error = EEXIST;
1301 		goto fail1;
1302 	}
1303 
1304 	module_load_sysctl(mod);	/* Set-up module's sysctl if any */
1305 
1306 	/*
1307 	 * Good, the module loaded successfully.  Put it onto the
1308 	 * list and add references to its requisite modules.
1309 	 */
1310 	TAILQ_REMOVE(pending, mod, mod_chain);
1311 	module_enqueue(mod);
1312 	if (modp != NULL) {
1313 		*modp = mod;
1314 	}
1315 	if (autoload && module_autotime > 0) {
1316 		/*
1317 		 * Arrange to try unloading the module after
1318 		 * a short delay unless auto-unload is disabled.
1319 		 */
1320 		mod->mod_autotime = time_second + module_autotime;
1321 		SET(mod->mod_flags, MODFLG_AUTO_LOADED);
1322 		module_thread_kick();
1323 	}
1324 	SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1325 	module_print("module `%s' loaded successfully", mi->mi_name);
1326 	module_callback_load(mod);
1327 	return 0;
1328 
1329  fail1:
1330 	(*mi->mi_modcmd)(MODULE_CMD_FINI, NULL);
1331  fail:
1332 	kobj_unload(mod->mod_kobj);
1333  fail2:
1334 	if (filedict != NULL) {
1335 		prop_object_release(filedict);
1336 		filedict = NULL;
1337 	}
1338 	TAILQ_REMOVE(pending, mod, mod_chain);
1339 	SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1340 	module_free(mod);
1341 	return error;
1342 }
1343 
1344 /*
1345  * module_do_unload:
1346  *
1347  *	Helper routine: do the dirty work of unloading a module.
1348  */
1349 static int
1350 module_do_unload(const char *name, bool load_requires_force)
1351 {
1352 	module_t *mod, *prev_active;
1353 	int error;
1354 	u_int i;
1355 
1356 	KASSERT(kernconfig_is_held());
1357 	KASSERT(name != NULL);
1358 
1359 	module_print("unload requested for '%s' (%s)", name,
1360 	    load_requires_force ? "TRUE" : "FALSE");
1361 	mod = module_lookup(name);
1362 	if (mod == NULL) {
1363 		module_error("module `%s' not found", name);
1364 		return ENOENT;
1365 	}
1366 	if (mod->mod_refcnt != 0) {
1367 		module_print("module `%s' busy (%d refs)", name,
1368 		    mod->mod_refcnt);
1369 		return EBUSY;
1370 	}
1371 
1372 	/*
1373 	 * Builtin secmodels are there to stay.
1374 	 */
1375 	if (mod->mod_source == MODULE_SOURCE_KERNEL &&
1376 	    mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) {
1377 		module_print("cannot unload built-in secmodel module `%s'",
1378 		    name);
1379 		return EPERM;
1380 	}
1381 
1382 	prev_active = module_active;
1383 	module_active = mod;
1384 	module_callback_unload(mod);
1385 
1386 	/*
1387 	 * If there were any registered SYSCTL_SETUP funcs, make sure
1388 	 * we release the sysctl entries
1389 	 */
1390 	if (mod->mod_sysctllog) {
1391 		sysctl_teardown(&mod->mod_sysctllog);
1392 	}
1393 	error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL);
1394 	module_active = prev_active;
1395 	if (error != 0) {
1396 		module_load_sysctl(mod);	/* re-enable sysctl stuff */
1397 		module_print("cannot unload module `%s' error=%d", name,
1398 		    error);
1399 		return error;
1400 	}
1401 	module_count--;
1402 	TAILQ_REMOVE(&module_list, mod, mod_chain);
1403 	for (i = 0; i < mod->mod_nrequired; i++) {
1404 		(*mod->mod_required)[i]->mod_refcnt--;
1405 	}
1406 	module_print("unloaded module `%s'", name);
1407 	if (mod->mod_kobj != NULL) {
1408 		kobj_unload(mod->mod_kobj);
1409 	}
1410 	if (mod->mod_source == MODULE_SOURCE_KERNEL) {
1411 		if (mod->mod_required != NULL) {
1412 			/*
1413 			 * release "required" resources - will be re-parsed
1414 			 * if the module is re-enabled
1415 			 */
1416 			kmem_free(mod->mod_required,
1417 			    mod->mod_arequired * sizeof(module_t *));
1418 			mod->mod_nrequired = 0;
1419 			mod->mod_arequired = 0;
1420 			mod->mod_required = NULL;
1421 		}
1422 		if (load_requires_force)
1423 			module_require_force(mod);
1424 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
1425 		module_builtinlist++;
1426 	} else {
1427 		module_free(mod);
1428 	}
1429 	module_gen++;
1430 
1431 	return 0;
1432 }
1433 
1434 /*
1435  * module_prime:
1436  *
1437  *	Push a module loaded by the bootloader onto our internal
1438  *	list.
1439  */
1440 int
1441 module_prime(const char *name, void *base, size_t size)
1442 {
1443 	__link_set_decl(modules, modinfo_t);
1444 	modinfo_t *const *mip;
1445 	module_t *mod;
1446 	int error;
1447 
1448 	/* Check for module name same as a built-in module */
1449 
1450 	__link_set_foreach(mip, modules) {
1451 		if (*mip == &module_dummy)
1452 			continue;
1453 		if (strcmp((*mip)->mi_name, name) == 0) {
1454 			module_error("module `%s' pushed by boot loader "
1455 			    "already exists", name);
1456 			return EEXIST;
1457 		}
1458 	}
1459 
1460 	/* Also eliminate duplicate boolist entries */
1461 
1462 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
1463 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1464 			module_error("duplicate bootlist entry for module "
1465 			    "`%s'", name);
1466 			return EEXIST;
1467 		}
1468 	}
1469 
1470 	mod = module_newmodule(MODULE_SOURCE_BOOT);
1471 	if (mod == NULL) {
1472 		return ENOMEM;
1473 	}
1474 
1475 	error = kobj_load_mem(&mod->mod_kobj, name, base, size);
1476 	if (error != 0) {
1477 		module_free(mod);
1478 		module_error("unable to load `%s' pushed by boot loader, "
1479 		    "error %d", name, error);
1480 		return error;
1481 	}
1482 	error = module_fetch_info(mod);
1483 	if (error != 0) {
1484 		kobj_unload(mod->mod_kobj);
1485 		module_free(mod);
1486 		module_error("unable to fetch_info for `%s' pushed by boot "
1487 		    "loader, error %d", name, error);
1488 		return error;
1489 	}
1490 
1491 	TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain);
1492 
1493 	return 0;
1494 }
1495 
1496 /*
1497  * module_fetch_into:
1498  *
1499  *	Fetch modinfo record from a loaded module.
1500  */
1501 static int
1502 module_fetch_info(module_t *mod)
1503 {
1504 	int error;
1505 	void *addr;
1506 	size_t size;
1507 
1508 	/*
1509 	 * Find module info record and check compatibility.
1510 	 */
1511 	error = kobj_find_section(mod->mod_kobj, "link_set_modules",
1512 	    &addr, &size);
1513 	if (error != 0) {
1514 		module_error("`link_set_modules' section not present, "
1515 		    "error %d", error);
1516 		return error;
1517 	}
1518 	if (size != sizeof(modinfo_t **)) {
1519 		module_error("`link_set_modules' section wrong size "
1520 		    "(got %zu, wanted %zu)", size, sizeof(modinfo_t **));
1521 		return ENOEXEC;
1522 	}
1523 	mod->mod_info = *(modinfo_t **)addr;
1524 
1525 	return 0;
1526 }
1527 
1528 /*
1529  * module_find_section:
1530  *
1531  *	Allows a module that is being initialized to look up a section
1532  *	within its ELF object.
1533  */
1534 int
1535 module_find_section(const char *name, void **addr, size_t *size)
1536 {
1537 
1538 	KASSERT(kernconfig_is_held());
1539 	KASSERT(module_active != NULL);
1540 
1541 	return kobj_find_section(module_active->mod_kobj, name, addr, size);
1542 }
1543 
1544 /*
1545  * module_thread:
1546  *
1547  *	Automatically unload modules.  We try once to unload autoloaded
1548  *	modules after module_autotime seconds.  If the system is under
1549  *	severe memory pressure, we'll try unloading all modules, else if
1550  *	module_autotime is zero, we don't try to unload, even if the
1551  *	module was previously scheduled for unload.
1552  */
1553 static void
1554 module_thread(void *cookie)
1555 {
1556 	module_t *mod, *next;
1557 	modinfo_t *mi;
1558 	int error;
1559 
1560 	for (;;) {
1561 		kernconfig_lock();
1562 		for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) {
1563 			next = TAILQ_NEXT(mod, mod_chain);
1564 
1565 			/* skip built-in modules */
1566 			if (mod->mod_source == MODULE_SOURCE_KERNEL)
1567 				continue;
1568 			/* skip modules that weren't auto-loaded */
1569 			if (!ISSET(mod->mod_flags, MODFLG_AUTO_LOADED))
1570 				continue;
1571 
1572 			if (uvmexp.free < uvmexp.freemin) {
1573 				module_thread_ticks = hz;
1574 			} else if (module_autotime == 0 ||
1575 				   mod->mod_autotime == 0) {
1576 				continue;
1577 			} else if (time_second < mod->mod_autotime) {
1578 				module_thread_ticks = hz;
1579 			    	continue;
1580 			} else {
1581 				mod->mod_autotime = 0;
1582 			}
1583 
1584 			/*
1585 			 * If this module wants to avoid autounload then
1586 			 * skip it.  Some modules can ping-pong in and out
1587 			 * because their use is transient but often.
1588 			 * Example: exec_script.
1589 			 */
1590 			mi = mod->mod_info;
1591 			error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL);
1592 			if (error == 0 || error == ENOTTY) {
1593 				(void)module_do_unload(mi->mi_name, false);
1594 			} else
1595 				module_print("module `%s' declined to be "
1596 				    "auto-unloaded error=%d", mi->mi_name,
1597 				    error);
1598 		}
1599 		kernconfig_unlock();
1600 
1601 		mutex_enter(&module_thread_lock);
1602 		(void)cv_timedwait(&module_thread_cv, &module_thread_lock,
1603 		    module_thread_ticks);
1604 		module_thread_ticks = 0;
1605 		mutex_exit(&module_thread_lock);
1606 	}
1607 }
1608 
1609 /*
1610  * module_thread:
1611  *
1612  *	Kick the module thread into action, perhaps because the
1613  *	system is low on memory.
1614  */
1615 void
1616 module_thread_kick(void)
1617 {
1618 
1619 	mutex_enter(&module_thread_lock);
1620 	module_thread_ticks = hz;
1621 	cv_broadcast(&module_thread_cv);
1622 	mutex_exit(&module_thread_lock);
1623 }
1624 
1625 #ifdef DDB
1626 /*
1627  * module_whatis:
1628  *
1629  *	Helper routine for DDB.
1630  */
1631 void
1632 module_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1633 {
1634 	module_t *mod;
1635 	size_t msize;
1636 	vaddr_t maddr;
1637 
1638 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1639 		if (mod->mod_kobj == NULL) {
1640 			continue;
1641 		}
1642 		if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1643 			continue;
1644 		if (addr < maddr || addr >= maddr + msize) {
1645 			continue;
1646 		}
1647 		(*pr)("%p is %p+%zu, in kernel module `%s'\n",
1648 		    (void *)addr, (void *)maddr,
1649 		    (size_t)(addr - maddr), mod->mod_info->mi_name);
1650 	}
1651 }
1652 
1653 /*
1654  * module_print_list:
1655  *
1656  *	Helper routine for DDB.
1657  */
1658 void
1659 module_print_list(void (*pr)(const char *, ...))
1660 {
1661 	const char *src;
1662 	module_t *mod;
1663 	size_t msize;
1664 	vaddr_t maddr;
1665 
1666 	(*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE");
1667 
1668 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1669 		switch (mod->mod_source) {
1670 		case MODULE_SOURCE_KERNEL:
1671 			src = "builtin";
1672 			break;
1673 		case MODULE_SOURCE_FILESYS:
1674 			src = "filesys";
1675 			break;
1676 		case MODULE_SOURCE_BOOT:
1677 			src = "boot";
1678 			break;
1679 		default:
1680 			src = "unknown";
1681 			break;
1682 		}
1683 		if (mod->mod_kobj == NULL) {
1684 			maddr = 0;
1685 			msize = 0;
1686 		} else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1687 			continue;
1688 		(*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name,
1689 		    (long)maddr, (long)msize, src);
1690 	}
1691 }
1692 #endif	/* DDB */
1693 
1694 static bool
1695 module_merge_dicts(prop_dictionary_t existing_dict,
1696 		   const prop_dictionary_t new_dict)
1697 {
1698 	prop_dictionary_keysym_t props_keysym;
1699 	prop_object_iterator_t props_iter;
1700 	prop_object_t props_obj;
1701 	const char *props_key;
1702 	bool error;
1703 
1704 	if (new_dict == NULL) {			/* nothing to merge */
1705 		return true;
1706 	}
1707 
1708 	error = false;
1709 	props_iter = prop_dictionary_iterator(new_dict);
1710 	if (props_iter == NULL) {
1711 		return false;
1712 	}
1713 
1714 	while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) {
1715 		props_keysym = (prop_dictionary_keysym_t)props_obj;
1716 		props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym);
1717 		props_obj = prop_dictionary_get_keysym(new_dict, props_keysym);
1718 		if ((props_obj == NULL) || !prop_dictionary_set(existing_dict,
1719 		    props_key, props_obj)) {
1720 			error = true;
1721 			goto out;
1722 		}
1723 	}
1724 	error = false;
1725 
1726 out:
1727 	prop_object_iterator_release(props_iter);
1728 
1729 	return !error;
1730 }
1731 
1732 /*
1733  * module_specific_key_create:
1734  *
1735  *	Create a key for subsystem module-specific data.
1736  */
1737 specificdata_key_t
1738 module_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
1739 {
1740 
1741 	return specificdata_key_create(module_specificdata_domain, keyp, dtor);
1742 }
1743 
1744 /*
1745  * module_specific_key_delete:
1746  *
1747  *	Delete a key for subsystem module-specific data.
1748  */
1749 void
1750 module_specific_key_delete(specificdata_key_t key)
1751 {
1752 
1753 	return specificdata_key_delete(module_specificdata_domain, key);
1754 }
1755 
1756 /*
1757  * module_getspecific:
1758  *
1759  *	Return module-specific data corresponding to the specified key.
1760  */
1761 void *
1762 module_getspecific(module_t *mod, specificdata_key_t key)
1763 {
1764 
1765 	return specificdata_getspecific(module_specificdata_domain,
1766 	    &mod->mod_sdref, key);
1767 }
1768 
1769 /*
1770  * module_setspecific:
1771  *
1772  *	Set module-specific data corresponding to the specified key.
1773  */
1774 void
1775 module_setspecific(module_t *mod, specificdata_key_t key, void *data)
1776 {
1777 
1778 	specificdata_setspecific(module_specificdata_domain,
1779 	    &mod->mod_sdref, key, data);
1780 }
1781 
1782 /*
1783  * module_register_callbacks:
1784  *
1785  *	Register a new set of callbacks to be called on module load/unload.
1786  *	Call the load callback on each existing module.
1787  *	Return an opaque handle for unregistering these later.
1788  */
1789 void *
1790 module_register_callbacks(void (*load)(struct module *),
1791     void (*unload)(struct module *))
1792 {
1793 	struct module_callbacks *modcb;
1794 	struct module *mod;
1795 
1796 	modcb = kmem_alloc(sizeof(*modcb), KM_SLEEP);
1797 	modcb->modcb_load = load;
1798 	modcb->modcb_unload = unload;
1799 
1800 	kernconfig_lock();
1801 	TAILQ_INSERT_TAIL(&modcblist, modcb, modcb_list);
1802 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1803 		load(mod);
1804 	kernconfig_unlock();
1805 
1806 	return modcb;
1807 }
1808 
1809 /*
1810  * module_unregister_callbacks:
1811  *
1812  *	Unregister a previously-registered set of module load/unload callbacks.
1813  *	Call the unload callback on each existing module.
1814  */
1815 void
1816 module_unregister_callbacks(void *opaque)
1817 {
1818 	struct module_callbacks *modcb;
1819 	struct module *mod;
1820 
1821 	modcb = opaque;
1822 	kernconfig_lock();
1823 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1824 		modcb->modcb_unload(mod);
1825 	TAILQ_REMOVE(&modcblist, modcb, modcb_list);
1826 	kernconfig_unlock();
1827 	kmem_free(modcb, sizeof(*modcb));
1828 }
1829 
1830 /*
1831  * module_callback_load:
1832  *
1833  *	Helper routine: call all load callbacks on a module being loaded.
1834  */
1835 static void
1836 module_callback_load(struct module *mod)
1837 {
1838 	struct module_callbacks *modcb;
1839 
1840 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1841 		modcb->modcb_load(mod);
1842 	}
1843 }
1844 
1845 /*
1846  * module_callback_unload:
1847  *
1848  *	Helper routine: call all unload callbacks on a module being unloaded.
1849  */
1850 static void
1851 module_callback_unload(struct module *mod)
1852 {
1853 	struct module_callbacks *modcb;
1854 
1855 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1856 		modcb->modcb_unload(mod);
1857 	}
1858 }
1859