xref: /netbsd-src/sys/kern/kern_module.c (revision ecf6466c633518f478c293c388551b29e46729cc)
1 /*	$NetBSD: kern_module.c,v 1.146 2020/01/22 22:39:27 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 1.146 2020/01/22 22:39:27 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/lwp.h>
51 #include <sys/kauth.h>
52 #include <sys/kobj.h>
53 #include <sys/kmem.h>
54 #include <sys/module.h>
55 #include <sys/module_hook.h>
56 #include <sys/kthread.h>
57 #include <sys/sysctl.h>
58 #include <sys/lock.h>
59 
60 #include <uvm/uvm_extern.h>
61 
62 struct vm_map *module_map;
63 const char *module_machine;
64 char	module_base[MODULE_BASE_SIZE];
65 
66 struct modlist        module_list = TAILQ_HEAD_INITIALIZER(module_list);
67 struct modlist        module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins);
68 static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist);
69 
70 struct module_callbacks {
71 	TAILQ_ENTRY(module_callbacks) modcb_list;
72 	void (*modcb_load)(struct module *);
73 	void (*modcb_unload)(struct module *);
74 };
75 TAILQ_HEAD(modcblist, module_callbacks);
76 static struct modcblist modcblist;
77 
78 static module_t *module_netbsd;
79 static const modinfo_t module_netbsd_modinfo = {
80 	.mi_version = __NetBSD_Version__,
81 	.mi_class = MODULE_CLASS_MISC,
82 	.mi_name = "netbsd"
83 };
84 
85 static module_t	*module_active;
86 bool		module_verbose_on;
87 #ifdef MODULAR_DEFAULT_AUTOLOAD
88 bool		module_autoload_on = true;
89 #else
90 bool		module_autoload_on = false;
91 #endif
92 u_int		module_count;
93 u_int		module_builtinlist;
94 u_int		module_autotime = 10;
95 u_int		module_gen = 1;
96 static kcondvar_t module_thread_cv;
97 static kmutex_t module_thread_lock;
98 static int	module_thread_ticks;
99 int (*module_load_vfs_vec)(const char *, int, bool, module_t *,
100 			   prop_dictionary_t *) = (void *)eopnotsupp;
101 
102 static kauth_listener_t	module_listener;
103 
104 static specificdata_domain_t module_specificdata_domain;
105 
106 /* Ensure that the kernel's link set isn't empty. */
107 static modinfo_t module_dummy;
108 __link_set_add_rodata(modules, module_dummy);
109 
110 static module_t	*module_newmodule(modsrc_t);
111 static void	module_free(module_t *);
112 static void	module_require_force(module_t *);
113 static int	module_do_load(const char *, bool, int, prop_dictionary_t,
114 		    module_t **, modclass_t modclass, bool);
115 static int	module_do_unload(const char *, bool);
116 static int	module_do_builtin(const module_t *, const char *, module_t **,
117     prop_dictionary_t);
118 static int	module_fetch_info(module_t *);
119 static void	module_thread(void *);
120 
121 static module_t	*module_lookup(const char *);
122 static void	module_enqueue(module_t *);
123 
124 static bool	module_merge_dicts(prop_dictionary_t, const prop_dictionary_t);
125 
126 static void	sysctl_module_setup(void);
127 static int	sysctl_module_autotime(SYSCTLFN_PROTO);
128 
129 static void	module_callback_load(struct module *);
130 static void	module_callback_unload(struct module *);
131 
132 #define MODULE_CLASS_MATCH(mi, modclass) \
133 	((modclass) == MODULE_CLASS_ANY || (modclass) == (mi)->mi_class)
134 
135 static void
136 module_incompat(const modinfo_t *mi, int modclass)
137 {
138 	module_error("incompatible module class for `%s' (%d != %d)",
139 	    mi->mi_name, modclass, mi->mi_class);
140 }
141 
142 struct module *
143 module_kernel(void)
144 {
145 
146 	return module_netbsd;
147 }
148 
149 /*
150  * module_error:
151  *
152  *	Utility function: log an error.
153  */
154 void
155 module_error(const char *fmt, ...)
156 {
157 	va_list ap;
158 
159 	va_start(ap, fmt);
160 	printf("WARNING: module error: ");
161 	vprintf(fmt, ap);
162 	printf("\n");
163 	va_end(ap);
164 }
165 
166 /*
167  * module_print:
168  *
169  *	Utility function: log verbose output.
170  */
171 void
172 module_print(const char *fmt, ...)
173 {
174 	va_list ap;
175 
176 	if (module_verbose_on) {
177 		va_start(ap, fmt);
178 		printf("DEBUG: module: ");
179 		vprintf(fmt, ap);
180 		printf("\n");
181 		va_end(ap);
182 	}
183 }
184 
185 /*
186  * module_name:
187  *
188  *	Utility function: return the module's name.
189  */
190 const char *
191 module_name(struct module *mod)
192 {
193 
194 	return mod->mod_info->mi_name;
195 }
196 
197 /*
198  * module_source:
199  *
200  *	Utility function: return the module's source.
201  */
202 modsrc_t
203 module_source(struct module *mod)
204 {
205 
206 	return mod->mod_source;
207 }
208 
209 static int
210 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
211     void *arg0, void *arg1, void *arg2, void *arg3)
212 {
213 	int result;
214 
215 	result = KAUTH_RESULT_DEFER;
216 
217 	if (action != KAUTH_SYSTEM_MODULE)
218 		return result;
219 
220 	if ((uintptr_t)arg2 != 0)	/* autoload */
221 		result = KAUTH_RESULT_ALLOW;
222 
223 	return result;
224 }
225 
226 /*
227  * Allocate a new module_t
228  */
229 static module_t *
230 module_newmodule(modsrc_t source)
231 {
232 	module_t *mod;
233 
234 	mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
235 	mod->mod_source = source;
236 	specificdata_init(module_specificdata_domain, &mod->mod_sdref);
237 	return mod;
238 }
239 
240 /*
241  * Free a module_t
242  */
243 static void
244 module_free(module_t *mod)
245 {
246 
247 	specificdata_fini(module_specificdata_domain, &mod->mod_sdref);
248 	if (mod->mod_required)
249 		kmem_free(mod->mod_required, mod->mod_arequired *
250 		    sizeof(module_t *));
251 	kmem_free(mod, sizeof(*mod));
252 }
253 
254 /*
255  * Require the -f (force) flag to load a module
256  */
257 static void
258 module_require_force(struct module *mod)
259 {
260 	SET(mod->mod_flags, MODFLG_MUST_FORCE);
261 }
262 
263 /*
264  * Add modules to the builtin list.  This can done at boottime or
265  * at runtime if the module is linked into the kernel with an
266  * external linker.  All or none of the input will be handled.
267  * Optionally, the modules can be initialized.  If they are not
268  * initialized, module_init_class() or module_load() can be used
269  * later, but these are not guaranteed to give atomic results.
270  */
271 int
272 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init)
273 {
274 	struct module **modp = NULL, *mod_iter;
275 	int rv = 0, i, mipskip;
276 
277 	if (init) {
278 		rv = kauth_authorize_system(kauth_cred_get(),
279 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD,
280 		    (void *)(uintptr_t)1, NULL);
281 		if (rv) {
282 			return rv;
283 		}
284 	}
285 
286 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
287 		if (mip[i] == &module_dummy) {
288 			KASSERT(nmodinfo > 0);
289 			nmodinfo--;
290 		}
291 	}
292 	if (nmodinfo == 0)
293 		return 0;
294 
295 	modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP);
296 	for (i = 0, mipskip = 0; i < nmodinfo; i++) {
297 		if (mip[i+mipskip] == &module_dummy) {
298 			mipskip++;
299 			continue;
300 		}
301 		modp[i] = module_newmodule(MODULE_SOURCE_KERNEL);
302 		modp[i]->mod_info = mip[i+mipskip];
303 	}
304 	kernconfig_lock();
305 
306 	/* do this in three stages for error recovery and atomicity */
307 
308 	/* first check for presence */
309 	for (i = 0; i < nmodinfo; i++) {
310 		TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) {
311 			if (strcmp(mod_iter->mod_info->mi_name,
312 			    modp[i]->mod_info->mi_name) == 0)
313 				break;
314 		}
315 		if (mod_iter) {
316 			rv = EEXIST;
317 			goto out;
318 		}
319 
320 		if (module_lookup(modp[i]->mod_info->mi_name) != NULL) {
321 			rv = EEXIST;
322 			goto out;
323 		}
324 	}
325 
326 	/* then add to list */
327 	for (i = 0; i < nmodinfo; i++) {
328 		TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain);
329 		module_builtinlist++;
330 	}
331 
332 	/* finally, init (if required) */
333 	if (init) {
334 		for (i = 0; i < nmodinfo; i++) {
335 			rv = module_do_builtin(modp[i],
336 			    modp[i]->mod_info->mi_name, NULL, NULL);
337 			/* throw in the towel, recovery hard & not worth it */
338 			if (rv)
339 				panic("%s: builtin module \"%s\" init failed:"
340 				    " %d", __func__,
341 				    modp[i]->mod_info->mi_name, rv);
342 		}
343 	}
344 
345  out:
346 	kernconfig_unlock();
347 	if (rv != 0) {
348 		for (i = 0; i < nmodinfo; i++) {
349 			if (modp[i])
350 				module_free(modp[i]);
351 		}
352 	}
353 	kmem_free(modp, sizeof(*modp) * nmodinfo);
354 	return rv;
355 }
356 
357 /*
358  * Optionally fini and remove builtin module from the kernel.
359  * Note: the module will now be unreachable except via mi && builtin_add.
360  */
361 int
362 module_builtin_remove(modinfo_t *mi, bool fini)
363 {
364 	struct module *mod;
365 	int rv = 0;
366 
367 	if (fini) {
368 		rv = kauth_authorize_system(kauth_cred_get(),
369 		    KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD,
370 		    NULL, NULL);
371 		if (rv)
372 			return rv;
373 
374 		kernconfig_lock();
375 		rv = module_do_unload(mi->mi_name, true);
376 		if (rv) {
377 			goto out;
378 		}
379 	} else {
380 		kernconfig_lock();
381 	}
382 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
383 		if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0)
384 			break;
385 	}
386 	if (mod) {
387 		TAILQ_REMOVE(&module_builtins, mod, mod_chain);
388 		module_builtinlist--;
389 	} else {
390 		KASSERT(fini == false);
391 		rv = ENOENT;
392 	}
393 
394  out:
395 	kernconfig_unlock();
396 	return rv;
397 }
398 
399 /*
400  * module_init:
401  *
402  *	Initialize the module subsystem.
403  */
404 void
405 module_init(void)
406 {
407 	__link_set_decl(modules, modinfo_t);
408 	extern struct vm_map *module_map;
409 	modinfo_t *const *mip;
410 	int rv;
411 
412 	if (module_map == NULL) {
413 		module_map = kernel_map;
414 	}
415 	cv_init(&module_thread_cv, "mod_unld");
416 	mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE);
417 	TAILQ_INIT(&modcblist);
418 
419 #ifdef MODULAR	/* XXX */
420 	module_init_md();
421 #endif
422 
423 	if (!module_machine)
424 		module_machine = machine;
425 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
426 	snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules",
427 	    module_machine, osrelease);
428 #else						/* release */
429 	snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules",
430 	    module_machine, __NetBSD_Version__ / 100000000,
431 	    __NetBSD_Version__ / 1000000 % 100);
432 #endif
433 
434 	module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
435 	    module_listener_cb, NULL);
436 
437 	__link_set_foreach(mip, modules) {
438 		if ((rv = module_builtin_add(mip, 1, false)) != 0)
439 			module_error("builtin %s failed: %d\n",
440 			    (*mip)->mi_name, rv);
441 	}
442 
443 	sysctl_module_setup();
444 	module_specificdata_domain = specificdata_domain_create();
445 
446 	module_netbsd = module_newmodule(MODULE_SOURCE_KERNEL);
447 	module_netbsd->mod_refcnt = 1;
448 	module_netbsd->mod_info = &module_netbsd_modinfo;
449 }
450 
451 /*
452  * module_start_unload_thread:
453  *
454  *	Start the auto unload kthread.
455  */
456 void
457 module_start_unload_thread(void)
458 {
459 	int error;
460 
461 	error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread,
462 	    NULL, NULL, "modunload");
463 	if (error != 0)
464 		panic("%s: %d", __func__, error);
465 }
466 
467 /*
468  * module_builtin_require_force
469  *
470  * Require MODCTL_MUST_FORCE to load any built-in modules that have
471  * not yet been initialized
472  */
473 void
474 module_builtin_require_force(void)
475 {
476 	module_t *mod;
477 
478 	kernconfig_lock();
479 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
480 		module_require_force(mod);
481 	}
482 	kernconfig_unlock();
483 }
484 
485 static struct sysctllog *module_sysctllog;
486 
487 static int
488 sysctl_module_autotime(SYSCTLFN_ARGS)
489 {
490 	struct sysctlnode node;
491 	int t, error;
492 
493 	t = *(int *)rnode->sysctl_data;
494 
495 	node = *rnode;
496 	node.sysctl_data = &t;
497 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
498 	if (error || newp == NULL)
499 		return (error);
500 
501 	if (t < 0)
502 		return (EINVAL);
503 
504 	*(int *)rnode->sysctl_data = t;
505 	return (0);
506 }
507 
508 static void
509 sysctl_module_setup(void)
510 {
511 	const struct sysctlnode *node = NULL;
512 
513 	sysctl_createv(&module_sysctllog, 0, NULL, &node,
514 		CTLFLAG_PERMANENT,
515 		CTLTYPE_NODE, "module",
516 		SYSCTL_DESCR("Module options"),
517 		NULL, 0, NULL, 0,
518 		CTL_KERN, CTL_CREATE, CTL_EOL);
519 
520 	if (node == NULL)
521 		return;
522 
523 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
524 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
525 		CTLTYPE_BOOL, "autoload",
526 		SYSCTL_DESCR("Enable automatic load of modules"),
527 		NULL, 0, &module_autoload_on, 0,
528 		CTL_CREATE, CTL_EOL);
529 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
530 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
531 		CTLTYPE_BOOL, "verbose",
532 		SYSCTL_DESCR("Enable verbose output"),
533 		NULL, 0, &module_verbose_on, 0,
534 		CTL_CREATE, CTL_EOL);
535 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
536 		CTLFLAG_PERMANENT | CTLFLAG_READONLY,
537 		CTLTYPE_STRING, "path",
538 		SYSCTL_DESCR("Default module load path"),
539 		NULL, 0, module_base, 0,
540 		CTL_CREATE, CTL_EOL);
541 	sysctl_createv(&module_sysctllog, 0, &node, NULL,
542 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
543 		CTLTYPE_INT, "autotime",
544 		SYSCTL_DESCR("Auto-unload delay"),
545 		sysctl_module_autotime, 0, &module_autotime, 0,
546 		CTL_CREATE, CTL_EOL);
547 }
548 
549 /*
550  * module_init_class:
551  *
552  *	Initialize all built-in and pre-loaded modules of the
553  *	specified class.
554  */
555 void
556 module_init_class(modclass_t modclass)
557 {
558 	TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail);
559 	module_t *mod;
560 	modinfo_t *mi;
561 
562 	kernconfig_lock();
563 	/*
564 	 * Builtins first.  These will not depend on pre-loaded modules
565 	 * (because the kernel would not link).
566 	 */
567 	do {
568 		TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
569 			mi = mod->mod_info;
570 			if (!MODULE_CLASS_MATCH(mi, modclass))
571 				continue;
572 			/*
573 			 * If initializing a builtin module fails, don't try
574 			 * to load it again.  But keep it around and queue it
575 			 * on the builtins list after we're done with module
576 			 * init.  Don't set it to MODFLG_MUST_FORCE in case a
577 			 * future attempt to initialize can be successful.
578 			 * (If the module has previously been set to
579 			 * MODFLG_MUST_FORCE, don't try to override that!)
580 			 */
581 			if (ISSET(mod->mod_flags, MODFLG_MUST_FORCE) ||
582 			    module_do_builtin(mod, mi->mi_name, NULL,
583 			    NULL) != 0) {
584 				TAILQ_REMOVE(&module_builtins, mod, mod_chain);
585 				TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain);
586 			}
587 			break;
588 		}
589 	} while (mod != NULL);
590 
591 	/*
592 	 * Now preloaded modules.  These will be pulled off the
593 	 * list as we call module_do_load();
594 	 */
595 	do {
596 		TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
597 			mi = mod->mod_info;
598 			if (!MODULE_CLASS_MATCH(mi, modclass))
599 				continue;
600 			module_do_load(mi->mi_name, false, 0, NULL, NULL,
601 			    modclass, false);
602 			break;
603 		}
604 	} while (mod != NULL);
605 
606 	/* return failed builtin modules to builtin list */
607 	while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) {
608 		TAILQ_REMOVE(&bi_fail, mod, mod_chain);
609 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
610 	}
611 
612 	kernconfig_unlock();
613 }
614 
615 /*
616  * module_compatible:
617  *
618  *	Return true if the two supplied kernel versions are said to
619  *	have the same binary interface for kernel code.  The entire
620  *	version is signficant for the development tree (-current),
621  *	major and minor versions are significant for official
622  *	releases of the system.
623  */
624 bool
625 module_compatible(int v1, int v2)
626 {
627 
628 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
629 	return v1 == v2;
630 #else						/* release */
631 	return abs(v1 - v2) < 10000;
632 #endif
633 }
634 
635 /*
636  * module_load:
637  *
638  *	Load a single module from the file system.
639  */
640 int
641 module_load(const char *filename, int flags, prop_dictionary_t props,
642 	    modclass_t modclass)
643 {
644 	module_t *mod;
645 	int error;
646 
647 	/* Test if we already have the module loaded before
648 	 * authorizing so we have the opportunity to return EEXIST. */
649 	kernconfig_lock();
650 	mod = module_lookup(filename);
651 	if (mod != NULL) {
652 		module_print("%s module `%s' already loaded",
653 		    "requested", filename);
654 		error = EEXIST;
655 		goto out;
656 	}
657 
658 	/* Authorize. */
659 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
660 	    0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL);
661 	if (error != 0)
662 		goto out;
663 
664 	error = module_do_load(filename, false, flags, props, NULL, modclass,
665 	    false);
666 
667 out:
668 	kernconfig_unlock();
669 	return error;
670 }
671 
672 /*
673  * module_autoload:
674  *
675  *	Load a single module from the file system, system initiated.
676  */
677 int
678 module_autoload(const char *filename, modclass_t modclass)
679 {
680 	int error;
681 	struct proc *p = curlwp->l_proc;
682 
683 	kernconfig_lock();
684 
685 	/* Nothing if the user has disabled it. */
686 	if (!module_autoload_on) {
687 		kernconfig_unlock();
688 		return EPERM;
689 	}
690 
691         /* Disallow path separators and magic symlinks. */
692         if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL ||
693             strchr(filename, '.') != NULL) {
694 		kernconfig_unlock();
695         	return EPERM;
696 	}
697 
698 	/* Authorize. */
699 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
700 	    0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL);
701 
702 	if (error == 0)
703 		error = module_do_load(filename, false, 0, NULL, NULL, modclass,
704 		    true);
705 
706 	module_print("Autoload for `%s' requested by pid %d (%s), status %d\n",
707 	    filename, p->p_pid, p->p_comm, error);
708 	kernconfig_unlock();
709 	return error;
710 }
711 
712 /*
713  * module_unload:
714  *
715  *	Find and unload a module by name.
716  */
717 int
718 module_unload(const char *name)
719 {
720 	int error;
721 
722 	/* Authorize. */
723 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
724 	    0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL);
725 	if (error != 0) {
726 		return error;
727 	}
728 
729 	kernconfig_lock();
730 	error = module_do_unload(name, true);
731 	kernconfig_unlock();
732 
733 	return error;
734 }
735 
736 /*
737  * module_lookup:
738  *
739  *	Look up a module by name.
740  */
741 module_t *
742 module_lookup(const char *name)
743 {
744 	module_t *mod;
745 
746 	KASSERT(kernconfig_is_held());
747 
748 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
749 		if (strcmp(mod->mod_info->mi_name, name) == 0)
750 			break;
751 	}
752 
753 	return mod;
754 }
755 
756 /*
757  * module_hold:
758  *
759  *	Add a single reference to a module.  It's the caller's
760  *	responsibility to ensure that the reference is dropped
761  *	later.
762  */
763 void
764 module_hold(module_t *mod)
765 {
766 
767 	kernconfig_lock();
768 	mod->mod_refcnt++;
769 	kernconfig_unlock();
770 }
771 
772 /*
773  * module_rele:
774  *
775  *	Release a reference acquired with module_hold().
776  */
777 void
778 module_rele(module_t *mod)
779 {
780 
781 	kernconfig_lock();
782 	KASSERT(mod->mod_refcnt > 0);
783 	mod->mod_refcnt--;
784 	kernconfig_unlock();
785 }
786 
787 /*
788  * module_enqueue:
789  *
790  *	Put a module onto the global list and update counters.
791  */
792 void
793 module_enqueue(module_t *mod)
794 {
795 	int i;
796 
797 	KASSERT(kernconfig_is_held());
798 
799 	/*
800 	 * Put new entry at the head of the queue so autounload can unload
801 	 * requisite modules with only one pass through the queue.
802 	 */
803 	TAILQ_INSERT_HEAD(&module_list, mod, mod_chain);
804 	if (mod->mod_nrequired) {
805 
806 		/* Add references to the requisite modules. */
807 		for (i = 0; i < mod->mod_nrequired; i++) {
808 			KASSERT((*mod->mod_required)[i] != NULL);
809 			(*mod->mod_required)[i]->mod_refcnt++;
810 		}
811 	}
812 	module_count++;
813 	module_gen++;
814 }
815 
816 /*
817  * Our array of required module pointers starts with zero entries.  If we
818  * need to add a new entry, and the list is already full, we reallocate a
819  * larger array, adding MAXMODDEPS entries.
820  */
821 static void
822 alloc_required(module_t *mod)
823 {
824 	module_t *(*new)[], *(*old)[];
825 	int areq;
826 	int i;
827 
828 	if (mod->mod_nrequired >= mod->mod_arequired) {
829 		areq = mod->mod_arequired + MAXMODDEPS;
830 		old = mod->mod_required;
831 		new = kmem_zalloc(areq * sizeof(module_t *), KM_SLEEP);
832 		for (i = 0; i < mod->mod_arequired; i++)
833 			(*new)[i] = (*old)[i];
834 		mod->mod_required = new;
835 		if (old)
836 			kmem_free(old, mod->mod_arequired * sizeof(module_t *));
837 		mod->mod_arequired = areq;
838 	}
839 }
840 
841 /*
842  * module_do_builtin:
843  *
844  *	Initialize a module from the list of modules that are
845  *	already linked into the kernel.
846  */
847 static int
848 module_do_builtin(const module_t *pmod, const char *name, module_t **modp,
849     prop_dictionary_t props)
850 {
851 	const char *p, *s;
852 	char buf[MAXMODNAME];
853 	modinfo_t *mi = NULL;
854 	module_t *mod, *mod2, *mod_loaded, *prev_active;
855 	size_t len;
856 	int error;
857 
858 	KASSERT(kernconfig_is_held());
859 
860 	/*
861 	 * Search the list to see if we have a module by this name.
862 	 */
863 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
864 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
865 			mi = mod->mod_info;
866 			break;
867 		}
868 	}
869 
870 	/*
871 	 * Check to see if already loaded.  This might happen if we
872 	 * were already loaded as a dependency.
873 	 */
874 	if ((mod_loaded = module_lookup(name)) != NULL) {
875 		KASSERT(mod == NULL);
876 		if (modp)
877 			*modp = mod_loaded;
878 		return 0;
879 	}
880 
881 	/* Note! This is from TAILQ, not immediate above */
882 	if (mi == NULL) {
883 		/*
884 		 * XXX: We'd like to panic here, but currently in some
885 		 * cases (such as nfsserver + nfs), the dependee can be
886 		 * succesfully linked without the dependencies.
887 		 */
888 		module_error("built-in module %s can't find builtin "
889 		    "dependency `%s'", pmod->mod_info->mi_name, name);
890 		return ENOENT;
891 	}
892 
893 	/*
894 	 * Initialize pre-requisites.
895 	 */
896 	KASSERT(mod->mod_required == NULL);
897 	KASSERT(mod->mod_arequired == 0);
898 	KASSERT(mod->mod_nrequired == 0);
899 	if (mi->mi_required != NULL) {
900 		for (s = mi->mi_required; *s != '\0'; s = p) {
901 			if (*s == ',')
902 				s++;
903 			p = s;
904 			while (*p != '\0' && *p != ',')
905 				p++;
906 			len = uimin(p - s + 1, sizeof(buf));
907 			strlcpy(buf, s, len);
908 			if (buf[0] == '\0')
909 				break;
910 			alloc_required(mod);
911 			error = module_do_builtin(mod, buf, &mod2, NULL);
912 			if (error != 0) {
913 				module_error("built-in module %s prerequisite "
914 				    "%s failed, error %d", name, buf, error);
915 				goto fail;
916 			}
917 			(*mod->mod_required)[mod->mod_nrequired++] = mod2;
918 		}
919 	}
920 
921 	/*
922 	 * Try to initialize the module.
923 	 */
924 	prev_active = module_active;
925 	module_active = mod;
926 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props);
927 	module_active = prev_active;
928 	if (error != 0) {
929 		module_error("built-in module %s failed its MODULE_CMD_INIT, "
930 		    "error %d", mi->mi_name, error);
931 		goto fail;
932 	}
933 
934 	/* load always succeeds after this point */
935 
936 	TAILQ_REMOVE(&module_builtins, mod, mod_chain);
937 	module_builtinlist--;
938 	if (modp != NULL) {
939 		*modp = mod;
940 	}
941 	module_enqueue(mod);
942 	return 0;
943 
944  fail:
945 	if (mod->mod_required)
946 		kmem_free(mod->mod_required, mod->mod_arequired *
947 		    sizeof(module_t *));
948 	mod->mod_arequired = 0;
949 	mod->mod_nrequired = 0;
950 	mod->mod_required = NULL;
951 	return error;
952 }
953 
954 /*
955  * module_load_sysctl
956  *
957  * Check to see if a non-builtin module has any SYSCTL_SETUP() routine(s)
958  * registered.  If so, call it (them).
959  */
960 
961 static void
962 module_load_sysctl(module_t *mod)
963 {
964 	void (**ls_funcp)(struct sysctllog **);
965 	void *ls_start;
966 	size_t ls_size, count;
967 	int error;
968 
969 	/*
970 	 * Built-in modules don't have a mod_kobj so we cannot search
971 	 * for their link_set_sysctl_funcs
972 	 */
973 	if (mod->mod_source == MODULE_SOURCE_KERNEL)
974 		return;
975 
976 	error = kobj_find_section(mod->mod_kobj, "link_set_sysctl_funcs",
977 	    &ls_start, &ls_size);
978 	if (error == 0) {
979 		count = ls_size / sizeof(ls_start);
980 		ls_funcp = ls_start;
981 		while (count--) {
982 			(**ls_funcp)(&mod->mod_sysctllog);
983 			ls_funcp++;
984 		}
985 	}
986 	else
987 		error = 0;	/* no setup funcs registered */
988 }
989 
990 /*
991  * module_do_load:
992  *
993  *	Helper routine: load a module from the file system, or one
994  *	pushed by the boot loader.
995  */
996 static int
997 module_do_load(const char *name, bool isdep, int flags,
998 	       prop_dictionary_t props, module_t **modp, modclass_t modclass,
999 	       bool autoload)
1000 {
1001 	/* The pending list for this level of recursion */
1002 	TAILQ_HEAD(pending_t, module);
1003 	struct pending_t *pending;
1004 	struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending);
1005 
1006 	/* The stack of pending lists */
1007 	static SLIST_HEAD(pend_head, pend_entry) pend_stack =
1008 		SLIST_HEAD_INITIALIZER(pend_stack);
1009 	struct pend_entry {
1010 		SLIST_ENTRY(pend_entry) pe_entry;
1011 		struct pending_t *pe_pending;
1012 	} my_pend_entry;
1013 
1014 	modinfo_t *mi;
1015 	module_t *mod, *mod2, *prev_active;
1016 	prop_dictionary_t filedict;
1017 	char buf[MAXMODNAME];
1018 	const char *s, *p;
1019 	int error;
1020 	size_t len;
1021 
1022 	KASSERT(kernconfig_is_held());
1023 
1024 	filedict = NULL;
1025 	error = 0;
1026 
1027 	/*
1028 	 * Set up the pending list for this entry.  If this is an
1029 	 * internal entry (for a dependency), then use the same list
1030 	 * as for the outer call;  otherwise, it's an external entry
1031 	 * (possibly recursive, ie a module's xxx_modcmd(init, ...)
1032 	 * routine called us), so use the locally allocated list.  In
1033 	 * either case, add it to our stack.
1034 	 */
1035 	if (isdep) {
1036 		KASSERT(SLIST_FIRST(&pend_stack) != NULL);
1037 		pending = SLIST_FIRST(&pend_stack)->pe_pending;
1038 	} else
1039 		pending = &new_pending;
1040 	my_pend_entry.pe_pending = pending;
1041 	SLIST_INSERT_HEAD(&pend_stack, &my_pend_entry, pe_entry);
1042 
1043 	/*
1044 	 * Search the list of disabled builtins first.
1045 	 */
1046 	TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
1047 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1048 			break;
1049 		}
1050 	}
1051 	if (mod) {
1052 		if (ISSET(mod->mod_flags, MODFLG_MUST_FORCE) &&
1053 		    !ISSET(flags, MODCTL_LOAD_FORCE)) {
1054 			if (!autoload) {
1055 				module_error("use -f to reinstate "
1056 				    "builtin module `%s'", name);
1057 			}
1058 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1059 			return EPERM;
1060 		} else {
1061 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1062 			error = module_do_builtin(mod, name, modp, props);
1063 			return error;
1064 		}
1065 	}
1066 
1067 	/*
1068 	 * Load the module and link.  Before going to the file system,
1069 	 * scan the list of modules loaded by the boot loader.
1070 	 */
1071 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
1072 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1073 			TAILQ_REMOVE(&module_bootlist, mod, mod_chain);
1074 			break;
1075 		}
1076 	}
1077 	if (mod != NULL) {
1078 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1079 	} else {
1080 		/*
1081 		 * Check to see if module is already present.
1082 		 */
1083 		mod = module_lookup(name);
1084 		if (mod != NULL) {
1085 			if (modp != NULL) {
1086 				*modp = mod;
1087 			}
1088 			module_print("%s module `%s' already loaded",
1089 			    isdep ? "dependent" : "requested", name);
1090 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1091 			return EEXIST;
1092 		}
1093 
1094 		mod = module_newmodule(MODULE_SOURCE_FILESYS);
1095 		if (mod == NULL) {
1096 			module_error("out of memory for `%s'", name);
1097 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1098 			return ENOMEM;
1099 		}
1100 
1101 		error = module_load_vfs_vec(name, flags, autoload, mod,
1102 					    &filedict);
1103 		if (error != 0) {
1104 #ifdef DEBUG
1105 			/*
1106 			 * The exec class of modules contains a list of
1107 			 * modules that is the union of all the modules
1108 			 * available for each architecture, so we don't
1109 			 * print an error if they are missing.
1110 			 */
1111 			if ((modclass != MODULE_CLASS_EXEC || error != ENOENT)
1112 			    && root_device != NULL)
1113 				module_error("vfs load failed for `%s', "
1114 				    "error %d", name, error);
1115 #endif
1116 			SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1117 			module_free(mod);
1118 			return error;
1119 		}
1120 		TAILQ_INSERT_TAIL(pending, mod, mod_chain);
1121 
1122 		error = module_fetch_info(mod);
1123 		if (error != 0) {
1124 			module_error("cannot fetch info for `%s', error %d",
1125 			    name, error);
1126 			goto fail;
1127 		}
1128 	}
1129 
1130 	/*
1131 	 * Check compatibility.
1132 	 */
1133 	mi = mod->mod_info;
1134 	if (strnlen(mi->mi_name, MAXMODNAME) >= MAXMODNAME) {
1135 		error = EINVAL;
1136 		module_error("module name `%s' longer than %d", mi->mi_name,
1137 		    MAXMODNAME);
1138 		goto fail;
1139 	}
1140 	if (mi->mi_class <= MODULE_CLASS_ANY ||
1141 	    mi->mi_class >= MODULE_CLASS_MAX) {
1142 		error = EINVAL;
1143 		module_error("module `%s' has invalid class %d",
1144 		    mi->mi_name, mi->mi_class);
1145 		    goto fail;
1146 	}
1147 	if (!module_compatible(mi->mi_version, __NetBSD_Version__)) {
1148 		module_error("module `%s' built for `%d', system `%d'",
1149 		    mi->mi_name, mi->mi_version, __NetBSD_Version__);
1150 		if (ISSET(flags, MODCTL_LOAD_FORCE)) {
1151 			module_error("forced load, system may be unstable");
1152 		} else {
1153 			error = EPROGMISMATCH;
1154 			goto fail;
1155 		}
1156 	}
1157 
1158 	/*
1159 	 * If a specific kind of module was requested, ensure that we have
1160 	 * a match.
1161 	 */
1162 	if (!MODULE_CLASS_MATCH(mi, modclass)) {
1163 		module_incompat(mi, modclass);
1164 		error = ENOENT;
1165 		goto fail;
1166 	}
1167 
1168 	/*
1169 	 * If loading a dependency, `name' is a plain module name.
1170 	 * The name must match.
1171 	 */
1172 	if (isdep && strcmp(mi->mi_name, name) != 0) {
1173 		module_error("dependency name mismatch (`%s' != `%s')",
1174 		    name, mi->mi_name);
1175 		error = ENOENT;
1176 		goto fail;
1177 	}
1178 
1179 	/*
1180 	 * If we loaded a module from the filesystem, check the actual
1181 	 * module name (from the modinfo_t) to ensure another module
1182 	 * with the same name doesn't already exist.  (There's no
1183 	 * guarantee the filename will match the module name, and the
1184 	 * dup-symbols check may not be sufficient.)
1185 	 */
1186 	if (mod->mod_source == MODULE_SOURCE_FILESYS) {
1187 		mod2 = module_lookup(mod->mod_info->mi_name);
1188 		if ( mod2 && mod2 != mod) {
1189 			module_error("module with name `%s' already loaded",
1190 			    mod2->mod_info->mi_name);
1191 			error = EEXIST;
1192 			if (modp != NULL)
1193 				*modp = mod2;
1194 			goto fail;
1195 		}
1196 	}
1197 
1198 	/*
1199 	 * Block circular dependencies.
1200 	 */
1201 	TAILQ_FOREACH(mod2, pending, mod_chain) {
1202 		if (mod == mod2) {
1203 			continue;
1204 		}
1205 		if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) {
1206 			error = EDEADLK;
1207 			module_error("circular dependency detected for `%s'",
1208 			    mi->mi_name);
1209 			goto fail;
1210 		}
1211 	}
1212 
1213 	/*
1214 	 * Now try to load any requisite modules.
1215 	 */
1216 	if (mi->mi_required != NULL) {
1217 		mod->mod_arequired = 0;
1218 		for (s = mi->mi_required; *s != '\0'; s = p) {
1219 			if (*s == ',')
1220 				s++;
1221 			p = s;
1222 			while (*p != '\0' && *p != ',')
1223 				p++;
1224 			len = p - s + 1;
1225 			if (len >= MAXMODNAME) {
1226 				error = EINVAL;
1227 				module_error("required module name `%s' "
1228 				    "longer than %d", mi->mi_required,
1229 				    MAXMODNAME);
1230 				goto fail;
1231 			}
1232 			strlcpy(buf, s, len);
1233 			if (buf[0] == '\0')
1234 				break;
1235 			alloc_required(mod);
1236 			if (strcmp(buf, mi->mi_name) == 0) {
1237 				error = EDEADLK;
1238 				module_error("self-dependency detected for "
1239 				   "`%s'", mi->mi_name);
1240 				goto fail;
1241 			}
1242 			error = module_do_load(buf, true, flags, NULL,
1243 			    &mod2, MODULE_CLASS_ANY, true);
1244 			if (error != 0 && error != EEXIST) {
1245 				module_error("recursive load failed for `%s' "
1246 				    "(`%s' required), error %d", mi->mi_name,
1247 				    buf, error);
1248 				goto fail;
1249 			}
1250 			(*mod->mod_required)[mod->mod_nrequired++] = mod2;
1251 		}
1252 	}
1253 
1254 	/*
1255 	 * We loaded all needed modules successfully: perform global
1256 	 * relocations and initialize.
1257 	 */
1258 	{
1259 		char xname[MAXMODNAME];
1260 
1261 		/*
1262 		 * In case of error the entire module is gone, so we
1263 		 * need to save its name for possible error report.
1264 		 */
1265 
1266 		strlcpy(xname, mi->mi_name, MAXMODNAME);
1267 		error = kobj_affix(mod->mod_kobj, mi->mi_name);
1268 		if (error != 0) {
1269 			module_error("unable to affix module `%s', error %d",
1270 			    xname, error);
1271 			goto fail2;
1272 		}
1273 	}
1274 
1275 	if (filedict) {
1276 		if (!module_merge_dicts(filedict, props)) {
1277 			module_error("module properties failed for %s", name);
1278 			error = EINVAL;
1279 			goto fail;
1280 		}
1281 	}
1282 
1283 	prev_active = module_active;
1284 	module_active = mod;
1285 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props);
1286 	module_active = prev_active;
1287 	if (filedict) {
1288 		prop_object_release(filedict);
1289 		filedict = NULL;
1290 	}
1291 	if (error != 0) {
1292 		module_error("modcmd(CMD_INIT) failed for `%s', error %d",
1293 		    mi->mi_name, error);
1294 		goto fail;
1295 	}
1296 
1297 	/*
1298 	 * If a recursive load already added a module with the same
1299 	 * name, abort.
1300 	 */
1301 	mod2 = module_lookup(mi->mi_name);
1302 	if (mod2 && mod2 != mod) {
1303 		module_error("recursive load causes duplicate module `%s'",
1304 		    mi->mi_name);
1305 		error = EEXIST;
1306 		goto fail1;
1307 	}
1308 
1309 	module_load_sysctl(mod);	/* Set-up module's sysctl if any */
1310 
1311 	/*
1312 	 * Good, the module loaded successfully.  Put it onto the
1313 	 * list and add references to its requisite modules.
1314 	 */
1315 	TAILQ_REMOVE(pending, mod, mod_chain);
1316 	module_enqueue(mod);
1317 	if (modp != NULL) {
1318 		*modp = mod;
1319 	}
1320 	if (autoload && module_autotime > 0) {
1321 		/*
1322 		 * Arrange to try unloading the module after
1323 		 * a short delay unless auto-unload is disabled.
1324 		 */
1325 		mod->mod_autotime = time_second + module_autotime;
1326 		SET(mod->mod_flags, MODFLG_AUTO_LOADED);
1327 		module_thread_kick();
1328 	}
1329 	SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1330 	module_print("module `%s' loaded successfully", mi->mi_name);
1331 	module_callback_load(mod);
1332 	return 0;
1333 
1334  fail1:
1335 	(*mi->mi_modcmd)(MODULE_CMD_FINI, NULL);
1336  fail:
1337 	kobj_unload(mod->mod_kobj);
1338  fail2:
1339 	if (filedict != NULL) {
1340 		prop_object_release(filedict);
1341 		filedict = NULL;
1342 	}
1343 	TAILQ_REMOVE(pending, mod, mod_chain);
1344 	SLIST_REMOVE_HEAD(&pend_stack, pe_entry);
1345 	module_free(mod);
1346 	return error;
1347 }
1348 
1349 /*
1350  * module_do_unload:
1351  *
1352  *	Helper routine: do the dirty work of unloading a module.
1353  */
1354 static int
1355 module_do_unload(const char *name, bool load_requires_force)
1356 {
1357 	module_t *mod, *prev_active;
1358 	int error;
1359 	u_int i;
1360 
1361 	KASSERT(kernconfig_is_held());
1362 	KASSERT(name != NULL);
1363 
1364 	module_print("unload requested for '%s' (%s)", name,
1365 	    load_requires_force ? "TRUE" : "FALSE");
1366 	mod = module_lookup(name);
1367 	if (mod == NULL) {
1368 		module_error("module `%s' not found", name);
1369 		return ENOENT;
1370 	}
1371 	if (mod->mod_refcnt != 0) {
1372 		module_print("module `%s' busy (%d refs)", name,
1373 		    mod->mod_refcnt);
1374 		return EBUSY;
1375 	}
1376 
1377 	/*
1378 	 * Builtin secmodels are there to stay.
1379 	 */
1380 	if (mod->mod_source == MODULE_SOURCE_KERNEL &&
1381 	    mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) {
1382 		module_print("cannot unload built-in secmodel module `%s'",
1383 		    name);
1384 		return EPERM;
1385 	}
1386 
1387 	prev_active = module_active;
1388 	module_active = mod;
1389 	module_callback_unload(mod);
1390 
1391 	/*
1392 	 * If there were any registered SYSCTL_SETUP funcs, make sure
1393 	 * we release the sysctl entries
1394 	 */
1395 	if (mod->mod_sysctllog) {
1396 		sysctl_teardown(&mod->mod_sysctllog);
1397 	}
1398 	error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL);
1399 	module_active = prev_active;
1400 	if (error != 0) {
1401 		module_load_sysctl(mod);	/* re-enable sysctl stuff */
1402 		module_print("cannot unload module `%s' error=%d", name,
1403 		    error);
1404 		return error;
1405 	}
1406 	module_count--;
1407 	TAILQ_REMOVE(&module_list, mod, mod_chain);
1408 	for (i = 0; i < mod->mod_nrequired; i++) {
1409 		(*mod->mod_required)[i]->mod_refcnt--;
1410 	}
1411 	module_print("unloaded module `%s'", name);
1412 	if (mod->mod_kobj != NULL) {
1413 		kobj_unload(mod->mod_kobj);
1414 	}
1415 	if (mod->mod_source == MODULE_SOURCE_KERNEL) {
1416 		if (mod->mod_required != NULL) {
1417 			/*
1418 			 * release "required" resources - will be re-parsed
1419 			 * if the module is re-enabled
1420 			 */
1421 			kmem_free(mod->mod_required,
1422 			    mod->mod_arequired * sizeof(module_t *));
1423 			mod->mod_nrequired = 0;
1424 			mod->mod_arequired = 0;
1425 			mod->mod_required = NULL;
1426 		}
1427 		if (load_requires_force)
1428 			module_require_force(mod);
1429 		TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
1430 		module_builtinlist++;
1431 	} else {
1432 		module_free(mod);
1433 	}
1434 	module_gen++;
1435 
1436 	return 0;
1437 }
1438 
1439 /*
1440  * module_prime:
1441  *
1442  *	Push a module loaded by the bootloader onto our internal
1443  *	list.
1444  */
1445 int
1446 module_prime(const char *name, void *base, size_t size)
1447 {
1448 	__link_set_decl(modules, modinfo_t);
1449 	modinfo_t *const *mip;
1450 	module_t *mod;
1451 	int error;
1452 
1453 	/* Check for module name same as a built-in module */
1454 
1455 	__link_set_foreach(mip, modules) {
1456 		if (*mip == &module_dummy)
1457 			continue;
1458 		if (strcmp((*mip)->mi_name, name) == 0) {
1459 			module_error("module `%s' pushed by boot loader "
1460 			    "already exists", name);
1461 			return EEXIST;
1462 		}
1463 	}
1464 
1465 	/* Also eliminate duplicate boolist entries */
1466 
1467 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
1468 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
1469 			module_error("duplicate bootlist entry for module "
1470 			    "`%s'", name);
1471 			return EEXIST;
1472 		}
1473 	}
1474 
1475 	mod = module_newmodule(MODULE_SOURCE_BOOT);
1476 	if (mod == NULL) {
1477 		return ENOMEM;
1478 	}
1479 
1480 	error = kobj_load_mem(&mod->mod_kobj, name, base, size);
1481 	if (error != 0) {
1482 		module_free(mod);
1483 		module_error("unable to load `%s' pushed by boot loader, "
1484 		    "error %d", name, error);
1485 		return error;
1486 	}
1487 	error = module_fetch_info(mod);
1488 	if (error != 0) {
1489 		kobj_unload(mod->mod_kobj);
1490 		module_free(mod);
1491 		module_error("unable to fetch_info for `%s' pushed by boot "
1492 		    "loader, error %d", name, error);
1493 		return error;
1494 	}
1495 
1496 	TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain);
1497 
1498 	return 0;
1499 }
1500 
1501 /*
1502  * module_fetch_into:
1503  *
1504  *	Fetch modinfo record from a loaded module.
1505  */
1506 static int
1507 module_fetch_info(module_t *mod)
1508 {
1509 	int error;
1510 	void *addr;
1511 	size_t size;
1512 
1513 	/*
1514 	 * Find module info record and check compatibility.
1515 	 */
1516 	error = kobj_find_section(mod->mod_kobj, "link_set_modules",
1517 	    &addr, &size);
1518 	if (error != 0) {
1519 		module_error("`link_set_modules' section not present, "
1520 		    "error %d", error);
1521 		return error;
1522 	}
1523 	if (size != sizeof(modinfo_t **)) {
1524 		module_error("`link_set_modules' section wrong size "
1525 		    "(got %zu, wanted %zu)", size, sizeof(modinfo_t **));
1526 		return ENOEXEC;
1527 	}
1528 	mod->mod_info = *(modinfo_t **)addr;
1529 
1530 	return 0;
1531 }
1532 
1533 /*
1534  * module_find_section:
1535  *
1536  *	Allows a module that is being initialized to look up a section
1537  *	within its ELF object.
1538  */
1539 int
1540 module_find_section(const char *name, void **addr, size_t *size)
1541 {
1542 
1543 	KASSERT(kernconfig_is_held());
1544 	KASSERT(module_active != NULL);
1545 
1546 	return kobj_find_section(module_active->mod_kobj, name, addr, size);
1547 }
1548 
1549 /*
1550  * module_thread:
1551  *
1552  *	Automatically unload modules.  We try once to unload autoloaded
1553  *	modules after module_autotime seconds.  If the system is under
1554  *	severe memory pressure, we'll try unloading all modules, else if
1555  *	module_autotime is zero, we don't try to unload, even if the
1556  *	module was previously scheduled for unload.
1557  */
1558 static void
1559 module_thread(void *cookie)
1560 {
1561 	module_t *mod, *next;
1562 	modinfo_t *mi;
1563 	int error;
1564 
1565 	for (;;) {
1566 		kernconfig_lock();
1567 		for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) {
1568 			next = TAILQ_NEXT(mod, mod_chain);
1569 
1570 			/* skip built-in modules */
1571 			if (mod->mod_source == MODULE_SOURCE_KERNEL)
1572 				continue;
1573 			/* skip modules that weren't auto-loaded */
1574 			if (!ISSET(mod->mod_flags, MODFLG_AUTO_LOADED))
1575 				continue;
1576 
1577 			if (uvm_availmem() < uvmexp.freemin) {
1578 				module_thread_ticks = hz;
1579 			} else if (module_autotime == 0 ||
1580 				   mod->mod_autotime == 0) {
1581 				continue;
1582 			} else if (time_second < mod->mod_autotime) {
1583 				module_thread_ticks = hz;
1584 			    	continue;
1585 			} else {
1586 				mod->mod_autotime = 0;
1587 			}
1588 
1589 			/*
1590 			 * If this module wants to avoid autounload then
1591 			 * skip it.  Some modules can ping-pong in and out
1592 			 * because their use is transient but often.
1593 			 * Example: exec_script.
1594 			 */
1595 			mi = mod->mod_info;
1596 			error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL);
1597 			if (error == 0 || error == ENOTTY) {
1598 				(void)module_do_unload(mi->mi_name, false);
1599 			} else
1600 				module_print("module `%s' declined to be "
1601 				    "auto-unloaded error=%d", mi->mi_name,
1602 				    error);
1603 		}
1604 		kernconfig_unlock();
1605 
1606 		mutex_enter(&module_thread_lock);
1607 		(void)cv_timedwait(&module_thread_cv, &module_thread_lock,
1608 		    module_thread_ticks);
1609 		module_thread_ticks = 0;
1610 		mutex_exit(&module_thread_lock);
1611 	}
1612 }
1613 
1614 /*
1615  * module_thread:
1616  *
1617  *	Kick the module thread into action, perhaps because the
1618  *	system is low on memory.
1619  */
1620 void
1621 module_thread_kick(void)
1622 {
1623 
1624 	mutex_enter(&module_thread_lock);
1625 	module_thread_ticks = hz;
1626 	cv_broadcast(&module_thread_cv);
1627 	mutex_exit(&module_thread_lock);
1628 }
1629 
1630 #ifdef DDB
1631 /*
1632  * module_whatis:
1633  *
1634  *	Helper routine for DDB.
1635  */
1636 void
1637 module_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1638 {
1639 	module_t *mod;
1640 	size_t msize;
1641 	vaddr_t maddr;
1642 
1643 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1644 		if (mod->mod_kobj == NULL) {
1645 			continue;
1646 		}
1647 		if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1648 			continue;
1649 		if (addr < maddr || addr >= maddr + msize) {
1650 			continue;
1651 		}
1652 		(*pr)("%p is %p+%zu, in kernel module `%s'\n",
1653 		    (void *)addr, (void *)maddr,
1654 		    (size_t)(addr - maddr), mod->mod_info->mi_name);
1655 	}
1656 }
1657 
1658 /*
1659  * module_print_list:
1660  *
1661  *	Helper routine for DDB.
1662  */
1663 void
1664 module_print_list(void (*pr)(const char *, ...))
1665 {
1666 	const char *src;
1667 	module_t *mod;
1668 	size_t msize;
1669 	vaddr_t maddr;
1670 
1671 	(*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE");
1672 
1673 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1674 		switch (mod->mod_source) {
1675 		case MODULE_SOURCE_KERNEL:
1676 			src = "builtin";
1677 			break;
1678 		case MODULE_SOURCE_FILESYS:
1679 			src = "filesys";
1680 			break;
1681 		case MODULE_SOURCE_BOOT:
1682 			src = "boot";
1683 			break;
1684 		default:
1685 			src = "unknown";
1686 			break;
1687 		}
1688 		if (mod->mod_kobj == NULL) {
1689 			maddr = 0;
1690 			msize = 0;
1691 		} else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
1692 			continue;
1693 		(*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name,
1694 		    (long)maddr, (long)msize, src);
1695 	}
1696 }
1697 #endif	/* DDB */
1698 
1699 static bool
1700 module_merge_dicts(prop_dictionary_t existing_dict,
1701 		   const prop_dictionary_t new_dict)
1702 {
1703 	prop_dictionary_keysym_t props_keysym;
1704 	prop_object_iterator_t props_iter;
1705 	prop_object_t props_obj;
1706 	const char *props_key;
1707 	bool error;
1708 
1709 	if (new_dict == NULL) {			/* nothing to merge */
1710 		return true;
1711 	}
1712 
1713 	error = false;
1714 	props_iter = prop_dictionary_iterator(new_dict);
1715 	if (props_iter == NULL) {
1716 		return false;
1717 	}
1718 
1719 	while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) {
1720 		props_keysym = (prop_dictionary_keysym_t)props_obj;
1721 		props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym);
1722 		props_obj = prop_dictionary_get_keysym(new_dict, props_keysym);
1723 		if ((props_obj == NULL) || !prop_dictionary_set(existing_dict,
1724 		    props_key, props_obj)) {
1725 			error = true;
1726 			goto out;
1727 		}
1728 	}
1729 	error = false;
1730 
1731 out:
1732 	prop_object_iterator_release(props_iter);
1733 
1734 	return !error;
1735 }
1736 
1737 /*
1738  * module_specific_key_create:
1739  *
1740  *	Create a key for subsystem module-specific data.
1741  */
1742 specificdata_key_t
1743 module_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
1744 {
1745 
1746 	return specificdata_key_create(module_specificdata_domain, keyp, dtor);
1747 }
1748 
1749 /*
1750  * module_specific_key_delete:
1751  *
1752  *	Delete a key for subsystem module-specific data.
1753  */
1754 void
1755 module_specific_key_delete(specificdata_key_t key)
1756 {
1757 
1758 	return specificdata_key_delete(module_specificdata_domain, key);
1759 }
1760 
1761 /*
1762  * module_getspecific:
1763  *
1764  *	Return module-specific data corresponding to the specified key.
1765  */
1766 void *
1767 module_getspecific(module_t *mod, specificdata_key_t key)
1768 {
1769 
1770 	return specificdata_getspecific(module_specificdata_domain,
1771 	    &mod->mod_sdref, key);
1772 }
1773 
1774 /*
1775  * module_setspecific:
1776  *
1777  *	Set module-specific data corresponding to the specified key.
1778  */
1779 void
1780 module_setspecific(module_t *mod, specificdata_key_t key, void *data)
1781 {
1782 
1783 	specificdata_setspecific(module_specificdata_domain,
1784 	    &mod->mod_sdref, key, data);
1785 }
1786 
1787 /*
1788  * module_register_callbacks:
1789  *
1790  *	Register a new set of callbacks to be called on module load/unload.
1791  *	Call the load callback on each existing module.
1792  *	Return an opaque handle for unregistering these later.
1793  */
1794 void *
1795 module_register_callbacks(void (*load)(struct module *),
1796     void (*unload)(struct module *))
1797 {
1798 	struct module_callbacks *modcb;
1799 	struct module *mod;
1800 
1801 	modcb = kmem_alloc(sizeof(*modcb), KM_SLEEP);
1802 	modcb->modcb_load = load;
1803 	modcb->modcb_unload = unload;
1804 
1805 	kernconfig_lock();
1806 	TAILQ_INSERT_TAIL(&modcblist, modcb, modcb_list);
1807 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1808 		load(mod);
1809 	kernconfig_unlock();
1810 
1811 	return modcb;
1812 }
1813 
1814 /*
1815  * module_unregister_callbacks:
1816  *
1817  *	Unregister a previously-registered set of module load/unload callbacks.
1818  *	Call the unload callback on each existing module.
1819  */
1820 void
1821 module_unregister_callbacks(void *opaque)
1822 {
1823 	struct module_callbacks *modcb;
1824 	struct module *mod;
1825 
1826 	modcb = opaque;
1827 	kernconfig_lock();
1828 	TAILQ_FOREACH(mod, &module_list, mod_chain)
1829 		modcb->modcb_unload(mod);
1830 	TAILQ_REMOVE(&modcblist, modcb, modcb_list);
1831 	kernconfig_unlock();
1832 	kmem_free(modcb, sizeof(*modcb));
1833 }
1834 
1835 /*
1836  * module_callback_load:
1837  *
1838  *	Helper routine: call all load callbacks on a module being loaded.
1839  */
1840 static void
1841 module_callback_load(struct module *mod)
1842 {
1843 	struct module_callbacks *modcb;
1844 
1845 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1846 		modcb->modcb_load(mod);
1847 	}
1848 }
1849 
1850 /*
1851  * module_callback_unload:
1852  *
1853  *	Helper routine: call all unload callbacks on a module being unloaded.
1854  */
1855 static void
1856 module_callback_unload(struct module *mod)
1857 {
1858 	struct module_callbacks *modcb;
1859 
1860 	TAILQ_FOREACH(modcb, &modcblist, modcb_list) {
1861 		modcb->modcb_unload(mod);
1862 	}
1863 }
1864