xref: /netbsd-src/sys/kern/kern_module.c (revision da9817918ec7e88db2912a2882967c7570a83f47)
1 /*	$NetBSD: kern_module.c,v 1.48 2009/06/09 20:35:02 jnemeth 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 1.48 2009/06/09 20:35:02 jnemeth Exp $");
38 
39 #ifdef _KERNEL_OPT
40 #include "opt_ddb.h"
41 #include "opt_modular.h"
42 #endif
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/fcntl.h>
48 #include <sys/proc.h>
49 #include <sys/kauth.h>
50 #include <sys/kobj.h>
51 #include <sys/kmem.h>
52 #include <sys/module.h>
53 #include <sys/kauth.h>
54 #include <sys/kthread.h>
55 #include <sys/sysctl.h>
56 #include <sys/namei.h>
57 #include <sys/lock.h>
58 #include <sys/vnode.h>
59 #include <sys/stat.h>
60 
61 #include <uvm/uvm_extern.h>
62 
63 #include <machine/stdarg.h>
64 
65 struct vm_map *module_map;
66 
67 struct modlist	module_list = TAILQ_HEAD_INITIALIZER(module_list);
68 struct modlist	module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist);
69 static module_t	*module_active;
70 static char	module_base[64];
71 static int	module_verbose_on;
72 static int	module_autoload_on = 1;
73 u_int		module_count;
74 kmutex_t	module_lock;
75 u_int		module_autotime = 10;
76 u_int		module_gen = 1;
77 static kcondvar_t module_thread_cv;
78 static kmutex_t module_thread_lock;
79 static int	module_thread_ticks;
80 
81 /* Ensure that the kernel's link set isn't empty. */
82 static modinfo_t module_dummy;
83 __link_set_add_rodata(modules, module_dummy);
84 
85 static module_t	*module_lookup(const char *);
86 static int	module_do_load(const char *, bool, int, prop_dictionary_t,
87 		    module_t **, modclass_t class, bool);
88 static int	module_do_unload(const char *);
89 static void	module_error(const char *, ...)
90 			__attribute__((__format__(__printf__,1,2)));
91 static void	module_print(const char *, ...)
92 			__attribute__((__format__(__printf__,1,2)));
93 static int	module_do_builtin(const char *, module_t **);
94 static int	module_fetch_info(module_t *);
95 static void	module_thread(void *);
96 static int	module_load_plist_file(const char *, const bool, void **,
97 		    size_t *);
98 static bool	module_merge_dicts(prop_dictionary_t, const prop_dictionary_t);
99 
100 /*
101  * module_error:
102  *
103  *	Utility function: log an error.
104  */
105 static void
106 module_error(const char *fmt, ...)
107 {
108 	va_list ap;
109 
110 	va_start(ap, fmt);
111 	printf("WARNING: module error: ");
112 	vprintf(fmt, ap);
113 	printf("\n");
114 	va_end(ap);
115 }
116 
117 /*
118  * module_print:
119  *
120  *	Utility function: log verbose output.
121  */
122 static void
123 module_print(const char *fmt, ...)
124 {
125 	va_list ap;
126 
127 	if (module_verbose_on) {
128 		va_start(ap, fmt);
129 		printf("DEBUG: module: ");
130 		vprintf(fmt, ap);
131 		printf("\n");
132 		va_end(ap);
133 	}
134 }
135 
136 /*
137  * module_init:
138  *
139  *	Initialize the module subsystem.
140  */
141 void
142 module_init(void)
143 {
144 	extern struct vm_map *module_map;
145 	int error;
146 
147 	if (module_map == NULL) {
148 		module_map = kernel_map;
149 	}
150 	mutex_init(&module_lock, MUTEX_DEFAULT, IPL_NONE);
151 	cv_init(&module_thread_cv, "modunload");
152 	mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE);
153 #ifdef MODULAR	/* XXX */
154 	module_init_md();
155 #endif
156 
157 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
158 	snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules",
159 	    machine, osrelease);
160 #else						/* release */
161 	snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules",
162 	    machine, __NetBSD_Version__ / 100000000,
163 	    __NetBSD_Version__ / 1000000 % 100);
164 #endif
165 
166 	error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread,
167 	    NULL, NULL, "modunload");
168 	if (error != 0)
169 		panic("module_init: %d", error);
170 }
171 
172 SYSCTL_SETUP(sysctl_module_setup, "sysctl module setup")
173 {
174 	const struct sysctlnode *node = NULL;
175 
176 	sysctl_createv(clog, 0, NULL, NULL,
177 		CTLFLAG_PERMANENT,
178 		CTLTYPE_NODE, "kern", NULL,
179 		NULL, 0, NULL, 0,
180 		CTL_KERN, CTL_EOL);
181 	sysctl_createv(clog, 0, NULL, &node,
182 		CTLFLAG_PERMANENT,
183 		CTLTYPE_NODE, "module",
184 		SYSCTL_DESCR("Module options"),
185 		NULL, 0, NULL, 0,
186 		CTL_KERN, CTL_CREATE, CTL_EOL);
187 
188 	if (node == NULL)
189 		return;
190 
191 	sysctl_createv(clog, 0, &node, NULL,
192 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
193 		CTLTYPE_INT, "autoload",
194 		SYSCTL_DESCR("Enable automatic load of modules"),
195 		NULL, 0, &module_autoload_on, 0,
196 		CTL_CREATE, CTL_EOL);
197 	sysctl_createv(clog, 0, &node, NULL,
198 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
199 		CTLTYPE_INT, "verbose",
200 		SYSCTL_DESCR("Enable verbose output"),
201 		NULL, 0, &module_verbose_on, 0,
202 		CTL_CREATE, CTL_EOL);
203 }
204 
205 /*
206  * module_init_class:
207  *
208  *	Initialize all built-in and pre-loaded modules of the
209  *	specified class.
210  */
211 void
212 module_init_class(modclass_t class)
213 {
214 	__link_set_decl(modules, modinfo_t);
215 	modinfo_t *const *mip, *mi;
216 	module_t *mod;
217 
218 	mutex_enter(&module_lock);
219 	/*
220 	 * Builtins first.  These can't depend on pre-loaded modules.
221 	 */
222 	__link_set_foreach(mip, modules) {
223 		mi = *mip;
224 		if (mi == &module_dummy) {
225 			continue;
226 		}
227 		if (class != MODULE_CLASS_ANY && class != mi->mi_class) {
228 			continue;
229 		}
230 		(void)module_do_builtin(mi->mi_name, NULL);
231 	}
232 	/*
233 	 * Now preloaded modules.  These will be pulled off the
234 	 * list as we call module_do_load();
235 	 */
236 	do {
237 		TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
238 			mi = mod->mod_info;
239 			if (class != MODULE_CLASS_ANY &&
240 			    class != mi->mi_class)
241 				continue;
242 			module_do_load(mi->mi_name, false, 0, NULL, NULL,
243 			    class, false);
244 			break;
245 		}
246 	} while (mod != NULL);
247 	mutex_exit(&module_lock);
248 }
249 
250 /*
251  * module_compatible:
252  *
253  *	Return true if the two supplied kernel versions are said to
254  *	have the same binary interface for kernel code.  The entire
255  *	version is signficant for the development tree (-current),
256  *	major and minor versions are significant for official
257  *	releases of the system.
258  */
259 bool
260 module_compatible(int v1, int v2)
261 {
262 
263 #if __NetBSD_Version__ / 1000000 % 100 == 99	/* -current */
264 	return v1 == v2;
265 #else						/* release */
266 	return abs(v1 - v2) < 10000;
267 #endif
268 }
269 
270 /*
271  * module_load:
272  *
273  *	Load a single module from the file system.
274  */
275 int
276 module_load(const char *filename, int flags, prop_dictionary_t props,
277 	    modclass_t class)
278 {
279 	int error;
280 
281 	/* Authorize. */
282 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
283 	    0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL);
284 	if (error != 0) {
285 		return error;
286 	}
287 
288 	mutex_enter(&module_lock);
289 	error = module_do_load(filename, false, flags, props, NULL, class,
290 	    false);
291 	mutex_exit(&module_lock);
292 
293 	return error;
294 }
295 
296 /*
297  * module_autoload:
298  *
299  *	Load a single module from the file system, system initiated.
300  */
301 int
302 module_autoload(const char *filename, modclass_t class)
303 {
304 	int error;
305 
306 	KASSERT(mutex_owned(&module_lock));
307 
308 	/* Nothing if the user has disabled it. */
309 	if (!module_autoload_on) {
310 		return EPERM;
311 	}
312 
313         /* Disallow path seperators and magic symlinks. */
314         if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL ||
315             strchr(filename, '.') != NULL) {
316         	return EPERM;
317 	}
318 
319 	/* Authorize. */
320 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
321 	    0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL);
322 	if (error != 0) {
323 		return error;
324 	}
325 
326 	return module_do_load(filename, false, 0, NULL, NULL, class, true);
327 }
328 
329 /*
330  * module_unload:
331  *
332  *	Find and unload a module by name.
333  */
334 int
335 module_unload(const char *name)
336 {
337 	int error;
338 
339 	/* Authorize. */
340 	error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
341 	    0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL);
342 	if (error != 0) {
343 		return error;
344 	}
345 
346 	mutex_enter(&module_lock);
347 	error = module_do_unload(name);
348 	mutex_exit(&module_lock);
349 
350 	return error;
351 }
352 
353 /*
354  * module_lookup:
355  *
356  *	Look up a module by name.
357  */
358 module_t *
359 module_lookup(const char *name)
360 {
361 	module_t *mod;
362 
363 	KASSERT(mutex_owned(&module_lock));
364 
365 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
366 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
367 			break;
368 		}
369 	}
370 
371 	return mod;
372 }
373 
374 /*
375  * module_hold:
376  *
377  *	Add a single reference to a module.  It's the caller's
378  *	responsibility to ensure that the reference is dropped
379  *	later.
380  */
381 int
382 module_hold(const char *name)
383 {
384 	module_t *mod;
385 
386 	mutex_enter(&module_lock);
387 	mod = module_lookup(name);
388 	if (mod == NULL) {
389 		mutex_exit(&module_lock);
390 		return ENOENT;
391 	}
392 	mod->mod_refcnt++;
393 	mutex_exit(&module_lock);
394 
395 	return 0;
396 }
397 
398 /*
399  * module_rele:
400  *
401  *	Release a reference acquired with module_hold().
402  */
403 void
404 module_rele(const char *name)
405 {
406 	module_t *mod;
407 
408 	mutex_enter(&module_lock);
409 	mod = module_lookup(name);
410 	if (mod == NULL) {
411 		mutex_exit(&module_lock);
412 		panic("module_rele: gone");
413 	}
414 	mod->mod_refcnt--;
415 	mutex_exit(&module_lock);
416 }
417 
418 /*
419  * module_enqueue:
420  *
421  *	Put a module onto the global list and update counters.
422  */
423 static void
424 module_enqueue(module_t *mod)
425 {
426 	int i;
427 
428 	/*
429 	 * If there are requisite modules, put at the head of the queue.
430 	 * This is so that autounload can unload requisite modules with
431 	 * only one pass through the queue.
432 	 */
433 	if (mod->mod_nrequired) {
434 		TAILQ_INSERT_HEAD(&module_list, mod, mod_chain);
435 
436 		/* Add references to the requisite modules. */
437 		for (i = 0; i < mod->mod_nrequired; i++) {
438 			KASSERT(mod->mod_required[i] != NULL);
439 			mod->mod_required[i]->mod_refcnt++;
440 		}
441 	} else {
442 		TAILQ_INSERT_TAIL(&module_list, mod, mod_chain);
443 	}
444 	module_count++;
445 	module_gen++;
446 }
447 
448 /*
449  * module_do_builtin:
450  *
451  *	Initialize a single module from the list of modules that are
452  *	built into the kernel (linked into the kernel image).
453  */
454 static int
455 module_do_builtin(const char *name, module_t **modp)
456 {
457 	__link_set_decl(modules, modinfo_t);
458 	modinfo_t *const *mip;
459 	const char *p, *s;
460 	char buf[MAXMODNAME];
461 	modinfo_t *mi;
462 	module_t *mod, *mod2;
463 	size_t len;
464 	int error;
465 
466 	KASSERT(mutex_owned(&module_lock));
467 
468 	/*
469 	 * Check to see if already loaded.
470 	 */
471 	if ((mod = module_lookup(name)) != NULL) {
472 		if (modp != NULL) {
473 			*modp = mod;
474 		}
475 		return 0;
476 	}
477 
478 	/*
479 	 * Search the list to see if we have a module by this name.
480 	 */
481 	error = ENOENT;
482 	__link_set_foreach(mip, modules) {
483 		mi = *mip;
484 		if (mi == &module_dummy) {
485 			continue;
486 		}
487 		if (strcmp(mi->mi_name, name) == 0) {
488 			error = 0;
489 			break;
490 		}
491 	}
492 	if (error != 0) {
493 		module_error("can't find `%s'", name);
494 		return error;
495 	}
496 
497 	/*
498 	 * Initialize pre-requisites.
499 	 */
500 	mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
501 	if (mod == NULL) {
502 		module_error("out of memory for `%s'", name);
503 		return ENOMEM;
504 	}
505 	if (modp != NULL) {
506 		*modp = mod;
507 	}
508 	if (mi->mi_required != NULL) {
509 		for (s = mi->mi_required; *s != '\0'; s = p) {
510 			if (*s == ',')
511 				s++;
512 			p = s;
513 			while (*p != '\0' && *p != ',')
514 				p++;
515 			len = min(p - s + 1, sizeof(buf));
516 			strlcpy(buf, s, len);
517 			if (buf[0] == '\0')
518 				break;
519 			if (mod->mod_nrequired == MAXMODDEPS - 1) {
520 				module_error("too many required modules");
521 				kmem_free(mod, sizeof(*mod));
522 				return EINVAL;
523 			}
524 			error = module_do_builtin(buf, &mod2);
525 			if (error != 0) {
526 				kmem_free(mod, sizeof(*mod));
527 				return error;
528 			}
529 			mod->mod_required[mod->mod_nrequired++] = mod2;
530 		}
531 	}
532 
533 	/*
534 	 * Try to initialize the module.
535 	 */
536 	KASSERT(module_active == NULL);
537 	module_active = mod;
538 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, NULL);
539 	module_active = NULL;
540 	if (error != 0) {
541 		module_error("builtin module `%s' "
542 		    "failed to init", mi->mi_name);
543 		kmem_free(mod, sizeof(*mod));
544 		return error;
545 	}
546 	mod->mod_info = mi;
547 	mod->mod_source = MODULE_SOURCE_KERNEL;
548 	module_enqueue(mod);
549 	return 0;
550 }
551 
552 /*
553  * module_do_load:
554  *
555  *	Helper routine: load a module from the file system, or one
556  *	pushed by the boot loader.
557  */
558 static int
559 module_do_load(const char *name, bool isdep, int flags,
560 	       prop_dictionary_t props, module_t **modp, modclass_t class,
561 	       bool autoload)
562 {
563 	static TAILQ_HEAD(,module) pending = TAILQ_HEAD_INITIALIZER(pending);
564 	static int depth;
565 	const int maxdepth = 6;
566 	modinfo_t *mi;
567 	module_t *mod, *mod2;
568 	prop_dictionary_t filedict;
569 	void *plist;
570 	char buf[MAXMODNAME], *path;
571 	const char *s, *p;
572 	int error;
573 	size_t len, plistlen;
574 	bool nochroot;
575 
576 	KASSERT(mutex_owned(&module_lock));
577 
578 	filedict = NULL;
579 	path = NULL;
580 	error = 0;
581 	nochroot = false;
582 
583 	/*
584 	 * Avoid recursing too far.
585 	 */
586 	if (++depth > maxdepth) {
587 		module_error("too many required modules");
588 		depth--;
589 		return EMLINK;
590 	}
591 
592 	/*
593 	 * Load the module and link.  Before going to the file system,
594 	 * scan the list of modules loaded by the boot loader.  Just
595 	 * before init is started the list of modules loaded at boot
596 	 * will be purged.  Before init is started we can assume that
597 	 * `name' is a module name and not a path name.
598 	 */
599 	TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
600 		if (strcmp(mod->mod_info->mi_name, name) == 0) {
601 			TAILQ_REMOVE(&module_bootlist, mod, mod_chain);
602 			break;
603 		}
604 	}
605 	if (mod != NULL) {
606 		TAILQ_INSERT_TAIL(&pending, mod, mod_chain);
607 	} else {
608 		/*
609 		 * If a requisite module, check to see if it is
610 		 * already present.
611 		 */
612 		if (isdep) {
613 			TAILQ_FOREACH(mod, &module_list, mod_chain) {
614 				if (strcmp(mod->mod_info->mi_name, name) == 0) {
615 					break;
616 				}
617 			}
618 			if (mod != NULL) {
619 				if (modp != NULL) {
620 					*modp = mod;
621 				}
622 				depth--;
623 				return 0;
624 			}
625 		}
626 		mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
627 		if (mod == NULL) {
628 			module_error("out of memory for `%s'", name);
629 			depth--;
630 			return ENOMEM;
631 		}
632 		path = PNBUF_GET();
633 		if (!autoload) {
634 			nochroot = false;
635 			snprintf(path, MAXPATHLEN, "%s", name);
636 			error = kobj_load_file(&mod->mod_kobj, path, nochroot);
637 		}
638 		if (autoload || (error == ENOENT)) {
639 			nochroot = true;
640 			snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
641 			    module_base, name, name);
642 			error = kobj_load_file(&mod->mod_kobj, path, nochroot);
643 		}
644 		if (error != 0) {
645 			kmem_free(mod, sizeof(*mod));
646 			depth--;
647 			PNBUF_PUT(path);
648 			if (autoload) {
649 				module_print("Cannot load kernel object `%s'"
650 				    " error=%d", name, error);
651 			} else {
652 				module_error("Cannot load kernel object `%s'"
653 				    " error=%d", name, error);
654 			}
655 			return error;
656 		}
657 		TAILQ_INSERT_TAIL(&pending, mod, mod_chain);
658 		mod->mod_source = MODULE_SOURCE_FILESYS;
659 		error = module_fetch_info(mod);
660 		if (error != 0) {
661 			module_error("cannot fetch module info for `%s'",
662 			    name);
663 			goto fail;
664 		}
665 	}
666 
667 	/*
668 	 * Check compatibility.
669 	 */
670 	mi = mod->mod_info;
671 	if (strlen(mi->mi_name) >= MAXMODNAME) {
672 		error = EINVAL;
673 		module_error("module name `%s' too long", mi->mi_name);
674 		goto fail;
675 	}
676 	if (!module_compatible(mi->mi_version, __NetBSD_Version__)) {
677 		module_error("module built for `%d', system `%d'",
678 		    mi->mi_version, __NetBSD_Version__);
679 		if ((flags & MODCTL_LOAD_FORCE) != 0) {
680 			module_error("forced load, system may be unstable");
681 		} else {
682 			error = EPROGMISMATCH;
683 			goto fail;
684 		}
685 	}
686 
687 	/*
688 	 * If a specific kind of module was requested, ensure that we have
689 	 * a match.
690 	 */
691 	if (class != MODULE_CLASS_ANY && class != mi->mi_class) {
692 		module_print("incompatible module class for `%s' (%d != %d)",
693 		    name, class, mi->mi_class);
694 		error = ENOENT;
695 		goto fail;
696 	}
697 
698 	/*
699 	 * If loading a dependency, `name' is a plain module name.
700 	 * The name must match.
701 	 */
702 	if (isdep && strcmp(mi->mi_name, name) != 0) {
703 		module_error("dependency name mismatch (`%s' != `%s')",
704 		    name, mi->mi_name);
705 		error = ENOENT;
706 		goto fail;
707 	}
708 
709 	/*
710 	 * Check to see if the module is already loaded.  If so, we may
711 	 * have been recursively called to handle a dependency, so be sure
712 	 * to set modp.
713 	 */
714 	if ((mod2 = module_lookup(mi->mi_name)) != NULL) {
715 		if (modp != NULL)
716 			*modp = mod2;
717 		module_print("module `%s' already loaded", mi->mi_name);
718 		error = EEXIST;
719 		goto fail;
720 	}
721 
722 	/*
723 	 * Block circular dependencies.
724 	 */
725 	TAILQ_FOREACH(mod2, &pending, mod_chain) {
726 		if (mod == mod2) {
727 			continue;
728 		}
729 		if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) {
730 		    	error = EDEADLK;
731 			module_error("circular dependency detected for `%s'",
732 			    mi->mi_name);
733 		    	goto fail;
734 		}
735 	}
736 
737 	/*
738 	 * Now try to load any requisite modules.
739 	 */
740 	if (mi->mi_required != NULL) {
741 		for (s = mi->mi_required; *s != '\0'; s = p) {
742 			if (*s == ',')
743 				s++;
744 			p = s;
745 			while (*p != '\0' && *p != ',')
746 				p++;
747 			len = p - s + 1;
748 			if (len >= MAXMODNAME) {
749 				error = EINVAL;
750 				module_error("required module name `%s'"
751 				    " too long", mi->mi_required);
752 				goto fail;
753 			}
754 			strlcpy(buf, s, len);
755 			if (buf[0] == '\0')
756 				break;
757 			if (mod->mod_nrequired == MAXMODDEPS - 1) {
758 				error = EINVAL;
759 				module_error("too many required modules (%d)",
760 				    mod->mod_nrequired);
761 				goto fail;
762 			}
763 			if (strcmp(buf, mi->mi_name) == 0) {
764 				error = EDEADLK;
765 				module_error("self-dependency detected for "
766 				   "`%s'", mi->mi_name);
767 				goto fail;
768 			}
769 			error = module_do_load(buf, true, flags, NULL,
770 			    &mod->mod_required[mod->mod_nrequired++],
771 			    MODULE_CLASS_ANY, true);
772 			if (error != 0)
773 				goto fail;
774 		}
775 	}
776 
777 	/*
778 	 * We loaded all needed modules successfully: perform global
779 	 * relocations and initialize.
780 	 */
781 	error = kobj_affix(mod->mod_kobj, mi->mi_name);
782 	if (error != 0) {
783 		/* Cannot touch 'mi' as the module is now gone. */
784 		module_error("unable to affix module `%s'", name);
785 		goto fail2;
786 	}
787 
788 	/*
789 	 * Load and process <module>.prop if it exists.
790 	 */
791 	if (((flags & MODCTL_NO_PROP) == 0) &&
792 	    (mod->mod_source == MODULE_SOURCE_FILESYS)) {
793 		error = module_load_plist_file(path, nochroot, &plist,
794 		    &plistlen);
795 		if (error != 0) {
796 			module_print("plist load returned error %d for `%s'",
797 			    error, path);
798 		} else {
799 			filedict = prop_dictionary_internalize(plist);
800 			if (filedict == NULL) {
801 				error = EINVAL;
802 			} else if (!module_merge_dicts(filedict, props)) {
803 				error = EINVAL;
804 				prop_object_release(filedict);
805 				filedict = NULL;
806 			}
807 		}
808 		if (plist != NULL) {
809 			kmem_free(plist, PAGE_SIZE);
810 		}
811 		if ((error != 0) && (error != ENOENT)) {
812 			goto fail;
813 		}
814 	}
815 
816 	KASSERT(module_active == NULL);
817 	module_active = mod;
818 	error = (*mi->mi_modcmd)(MODULE_CMD_INIT, (filedict != NULL) ?
819 	    filedict : props);	/* props will have been merged with filedict */
820 	module_active = NULL;
821 	if (filedict != NULL) {
822 		prop_object_release(filedict);
823 	}
824 	if (error != 0) {
825 		module_error("modcmd function returned error %d for `%s'",
826 		    error, mi->mi_name);
827 		goto fail;
828 	}
829 
830 	/*
831 	 * Good, the module loaded successfully.  Put it onto the
832 	 * list and add references to its requisite modules.
833 	 */
834 	TAILQ_REMOVE(&pending, mod, mod_chain);
835 	module_enqueue(mod);
836 	if (modp != NULL) {
837 		*modp = mod;
838 	}
839 	if (autoload) {
840 		/*
841 		 * Arrange to try unloading the module after
842 		 * a short delay.
843 		 */
844 		mod->mod_autotime = time_second + module_autotime;
845 		module_thread_kick();
846 	}
847 	depth--;
848 	if (path != NULL)
849 		PNBUF_PUT(path);
850 	return 0;
851 
852  fail:
853 	kobj_unload(mod->mod_kobj);
854  fail2:
855 	TAILQ_REMOVE(&pending, mod, mod_chain);
856 	kmem_free(mod, sizeof(*mod));
857 	depth--;
858 	if (path != NULL)
859 		PNBUF_PUT(path);
860 	return error;
861 }
862 
863 /*
864  * module_do_unload:
865  *
866  *	Helper routine: do the dirty work of unloading a module.
867  */
868 static int
869 module_do_unload(const char *name)
870 {
871 	module_t *mod;
872 	int error;
873 	u_int i;
874 
875 	KASSERT(mutex_owned(&module_lock));
876 
877 	mod = module_lookup(name);
878 	if (mod == NULL) {
879 		module_error("module `%s' not found", name);
880 		return ENOENT;
881 	}
882 	if (mod->mod_refcnt != 0 || mod->mod_source == MODULE_SOURCE_KERNEL) {
883 		module_print("module `%s' busy", name);
884 		return EBUSY;
885 	}
886 	KASSERT(module_active == NULL);
887 	module_active = mod;
888 	error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL);
889 	module_active = NULL;
890 	if (error != 0) {
891 		module_print("cannot unload module `%s' error=%d", name,
892 		    error);
893 		return error;
894 	}
895 	module_count--;
896 	TAILQ_REMOVE(&module_list, mod, mod_chain);
897 	for (i = 0; i < mod->mod_nrequired; i++) {
898 		mod->mod_required[i]->mod_refcnt--;
899 	}
900 	if (mod->mod_kobj != NULL) {
901 		kobj_unload(mod->mod_kobj);
902 	}
903 	kmem_free(mod, sizeof(*mod));
904 	module_gen++;
905 
906 	return 0;
907 }
908 
909 /*
910  * module_prime:
911  *
912  *	Push a module loaded by the bootloader onto our internal
913  *	list.
914  */
915 int
916 module_prime(void *base, size_t size)
917 {
918 	module_t *mod;
919 	int error;
920 
921 	mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
922 	if (mod == NULL) {
923 		return ENOMEM;
924 	}
925 	mod->mod_source = MODULE_SOURCE_BOOT;
926 
927 	error = kobj_load_mem(&mod->mod_kobj, base, size);
928 	if (error != 0) {
929 		kmem_free(mod, sizeof(*mod));
930 		module_error("unable to load object pushed by boot loader");
931 		return error;
932 	}
933 	error = module_fetch_info(mod);
934 	if (error != 0) {
935 		kobj_unload(mod->mod_kobj);
936 		kmem_free(mod, sizeof(*mod));
937 		module_error("unable to load object pushed by boot loader");
938 		return error;
939 	}
940 
941 	TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain);
942 
943 	return 0;
944 }
945 
946 /*
947  * module_fetch_into:
948  *
949  *	Fetch modinfo record from a loaded module.
950  */
951 static int
952 module_fetch_info(module_t *mod)
953 {
954 	int error;
955 	void *addr;
956 	size_t size;
957 
958 	/*
959 	 * Find module info record and check compatibility.
960 	 */
961 	error = kobj_find_section(mod->mod_kobj, "link_set_modules",
962 	    &addr, &size);
963 	if (error != 0) {
964 		module_error("`link_set_modules' section not present");
965 		return error;
966 	}
967 	if (size != sizeof(modinfo_t **)) {
968 		module_error("`link_set_modules' section wrong size");
969 		return error;
970 	}
971 	mod->mod_info = *(modinfo_t **)addr;
972 
973 	return 0;
974 }
975 
976 /*
977  * module_find_section:
978  *
979  *	Allows a module that is being initialized to look up a section
980  *	within its ELF object.
981  */
982 int
983 module_find_section(const char *name, void **addr, size_t *size)
984 {
985 
986 	KASSERT(mutex_owned(&module_lock));
987 	KASSERT(module_active != NULL);
988 
989 	return kobj_find_section(module_active->mod_kobj, name, addr, size);
990 }
991 
992 /*
993  * module_thread:
994  *
995  *	Automatically unload modules.  We try once to unload autoloaded
996  *	modules after module_autotime seconds.  If the system is under
997  *	severe memory pressure, we'll try unloading all modules.
998  */
999 static void
1000 module_thread(void *cookie)
1001 {
1002 	module_t *mod, *next;
1003 	modinfo_t *mi;
1004 	int error;
1005 
1006 	for (;;) {
1007 		mutex_enter(&module_lock);
1008 		for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) {
1009 			next = TAILQ_NEXT(mod, mod_chain);
1010 			if (uvmexp.free < uvmexp.freemin) {
1011 				module_thread_ticks = hz;
1012 			} else if (mod->mod_autotime == 0) {
1013 				continue;
1014 			} else if (time_second < mod->mod_autotime) {
1015 				module_thread_ticks = hz;
1016 			    	continue;
1017 			} else {
1018 				mod->mod_autotime = 0;
1019 			}
1020 			/*
1021 			 * If this module wants to avoid autounload then
1022 			 * skip it.  Some modules can ping-pong in and out
1023 			 * because their use is transient but often.
1024 			 * Example: exec_script.
1025 			 */
1026 			mi = mod->mod_info;
1027 			error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL);
1028 			if (error == 0 || error == ENOTTY) {
1029 				(void)module_do_unload(mi->mi_name);
1030 			}
1031 		}
1032 		mutex_exit(&module_lock);
1033 
1034 		mutex_enter(&module_thread_lock);
1035 		(void)cv_timedwait(&module_thread_cv, &module_thread_lock,
1036 		    module_thread_ticks);
1037 		module_thread_ticks = 0;
1038 		mutex_exit(&module_thread_lock);
1039 	}
1040 }
1041 
1042 /*
1043  * module_thread:
1044  *
1045  *	Kick the module thread into action, perhaps because the
1046  *	system is low on memory.
1047  */
1048 void
1049 module_thread_kick(void)
1050 {
1051 
1052 	mutex_enter(&module_thread_lock);
1053 	module_thread_ticks = hz;
1054 	cv_broadcast(&module_thread_cv);
1055 	mutex_exit(&module_thread_lock);
1056 }
1057 
1058 #ifdef DDB
1059 /*
1060  * module_whatis:
1061  *
1062  *	Helper routine for DDB.
1063  */
1064 void
1065 module_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1066 {
1067 	module_t *mod;
1068 	size_t msize;
1069 	vaddr_t maddr;
1070 
1071 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1072 		if (mod->mod_kobj == NULL) {
1073 			continue;
1074 		}
1075 		kobj_stat(mod->mod_kobj, &maddr, &msize);
1076 		if (addr < maddr || addr >= maddr + msize) {
1077 			continue;
1078 		}
1079 		(*pr)("%p is %p+%zu, in kernel module `%s'\n",
1080 		    (void *)addr, (void *)maddr,
1081 		    (size_t)(addr - maddr), mod->mod_info->mi_name);
1082 	}
1083 }
1084 
1085 /*
1086  * module_print_list:
1087  *
1088  *	Helper routine for DDB.
1089  */
1090 void
1091 module_print_list(void (*pr)(const char *, ...))
1092 {
1093 	const char *src;
1094 	module_t *mod;
1095 	size_t msize;
1096 	vaddr_t maddr;
1097 
1098 	(*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE");
1099 
1100 	TAILQ_FOREACH(mod, &module_list, mod_chain) {
1101 		switch (mod->mod_source) {
1102 		case MODULE_SOURCE_KERNEL:
1103 			src = "builtin";
1104 			break;
1105 		case MODULE_SOURCE_FILESYS:
1106 			src = "filesys";
1107 			break;
1108 		case MODULE_SOURCE_BOOT:
1109 			src = "boot";
1110 			break;
1111 		default:
1112 			src = "unknown";
1113 			break;
1114 		}
1115 		if (mod->mod_kobj != NULL) {
1116 			kobj_stat(mod->mod_kobj, &maddr, &msize);
1117 		} else {
1118 			maddr = 0;
1119 			msize = 0;
1120 		}
1121 		(*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name,
1122 		    (long)maddr, (long)msize, src);
1123 	}
1124 }
1125 #endif	/* DDB */
1126 
1127 /*
1128  * module_load_plist_file:
1129  *
1130  *	Load a plist located in the file system into memory.
1131  */
1132 static int
1133 module_load_plist_file(const char *modpath, const bool nochroot,
1134 		       void **basep, size_t *length)
1135 {
1136 	struct nameidata nd;
1137 	struct stat sb;
1138 	void *base;
1139 	char *proppath;
1140 	size_t resid;
1141 	int error, pathlen;
1142 
1143 	base = NULL;
1144 	*length = 0;
1145 
1146 	proppath = PNBUF_GET();
1147 	strcpy(proppath, modpath);
1148 	pathlen = strlen(proppath);
1149 	if ((pathlen >= 5) && (strcmp(&proppath[pathlen - 5], ".kmod") == 0)) {
1150 		strcpy(&proppath[pathlen - 5], ".prop");
1151 	} else if (pathlen < MAXPATHLEN - 5) {
1152 			strcat(proppath, ".prop");
1153 	} else {
1154 		error = ENOENT;
1155 		goto out1;
1156 	}
1157 
1158 	NDINIT(&nd, LOOKUP, FOLLOW | (nochroot ? NOCHROOT : 0),
1159 	    UIO_SYSSPACE, proppath);
1160 
1161 	error = namei(&nd);
1162 	if (error != 0) {
1163 		goto out1;
1164 	}
1165 
1166 	error = vn_stat(nd.ni_vp, &sb);
1167 	if (sb.st_size >= (PAGE_SIZE - 1)) {	/* leave space for term \0 */
1168 		error = EINVAL;
1169 	}
1170 	if (error != 0) {
1171 		goto out1;
1172 	}
1173 
1174 	error = vn_open(&nd, FREAD, 0);
1175  	if (error != 0) {
1176 	 	goto out1;
1177 	}
1178 
1179 	base = kmem_alloc(PAGE_SIZE, KM_SLEEP);
1180 	if (base == NULL) {
1181 		error = ENOMEM;
1182 		goto out;
1183 	}
1184 
1185 	error = vn_rdwr(UIO_READ, nd.ni_vp, base, sb.st_size, 0,
1186 	    UIO_SYSSPACE, IO_NODELOCKED, curlwp->l_cred, &resid, curlwp);
1187 	*((uint8_t *)base + sb.st_size) = '\0';
1188 	if (error == 0 && resid != 0) {
1189 		error = EINVAL;
1190 	}
1191 	if (error != 0) {
1192 		kmem_free(base, PAGE_SIZE);
1193 		base = NULL;
1194 	}
1195 	*length = sb.st_size;
1196 
1197 out:
1198 	VOP_UNLOCK(nd.ni_vp, 0);
1199 	vn_close(nd.ni_vp, FREAD, kauth_cred_get());
1200 
1201 out1:
1202 	PNBUF_PUT(proppath);
1203 	*basep = base;
1204 	return error;
1205 }
1206 
1207 static bool
1208 module_merge_dicts(prop_dictionary_t existing_dict,
1209 		   const prop_dictionary_t new_dict)
1210 {
1211 	prop_dictionary_keysym_t props_keysym;
1212 	prop_object_iterator_t props_iter;
1213 	prop_object_t props_obj;
1214 	const char *props_key;
1215 	bool error;
1216 
1217 	error = false;
1218 	props_iter = prop_dictionary_iterator(new_dict);
1219 	if (props_iter == NULL) {
1220 		return false;
1221 	}
1222 
1223 	while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) {
1224 		props_keysym = (prop_dictionary_keysym_t)props_obj;
1225 		props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym);
1226 		props_obj = prop_dictionary_get_keysym(new_dict, props_keysym);
1227 		if ((props_obj == NULL) || !prop_dictionary_set(existing_dict,
1228 		    props_key, props_obj)) {
1229 			error = true;
1230 			goto out;
1231 		}
1232 	}
1233 	error = false;
1234 
1235 out:
1236 	prop_object_iterator_release(props_iter);
1237 
1238 	return !error;
1239 }
1240