xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 580744621f33383027108364dcadad718df46ffe)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 2000, Boris Popov
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *    This product includes software developed by Boris Popov.
18  * 4. Neither the name of the author nor the names of any co-contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $FreeBSD$
35  */
36 
37 #include <sys/types.h>
38 #include <sys/param.h>
39 #include <sys/endian.h>
40 #include <sys/exec.h>
41 #include <sys/queue.h>
42 #include <sys/kernel.h>
43 #include <sys/reboot.h>
44 #include <sys/linker.h>
45 #include <sys/stat.h>
46 #include <sys/module.h>
47 #define FREEBSD_ELF
48 
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <fts.h>
53 #include <stdbool.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <machine/elf.h>
59 
60 #include "ef.h"
61 
62 #define	MAXRECSIZE	(64 << 10)	/* 64k */
63 #define check(val)	if ((error = (val)) != 0) break
64 
65 static bool dflag;	/* do not create a hint file, only write on stdout */
66 static int verbose;
67 
68 static FILE *fxref;	/* current hints file */
69 
70 static const char *xref_file = "linker.hints";
71 
72 /*
73  * A record is stored in the static buffer recbuf before going to disk.
74  */
75 static char recbuf[MAXRECSIZE];
76 static int recpos;	/* current write position */
77 static int reccnt;	/* total record written to this file so far */
78 
79 static void
80 intalign(void)
81 {
82 
83 	recpos = roundup2(recpos, sizeof(int));
84 }
85 
86 static void
87 record_start(void)
88 {
89 
90 	recpos = 0;
91 	memset(recbuf, 0, MAXRECSIZE);
92 }
93 
94 static int
95 record_end(void)
96 {
97 
98 	if (recpos == 0)
99 		return (0);
100 	reccnt++;
101 	intalign();
102 	fwrite(&recpos, sizeof(recpos), 1, fxref);
103 	return (fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0);
104 }
105 
106 static int
107 record_buf(const void *buf, size_t size)
108 {
109 
110 	if (MAXRECSIZE - recpos < size)
111 		errx(1, "record buffer overflow");
112 	memcpy(recbuf + recpos, buf, size);
113 	recpos += size;
114 	return (0);
115 }
116 
117 /*
118  * An int is stored in host order and aligned
119  */
120 static int
121 record_int(int val)
122 {
123 
124 	intalign();
125 	return (record_buf(&val, sizeof(val)));
126 }
127 
128 /*
129  * A string is stored as 1-byte length plus data, no padding
130  */
131 static int
132 record_string(const char *str)
133 {
134 	int error;
135 	size_t len;
136 	u_char val;
137 
138 	if (dflag)
139 		return (0);
140 	val = len = strlen(str);
141 	if (len > 255)
142 		errx(1, "string %s too long", str);
143 	error = record_buf(&val, sizeof(val));
144 	if (error != 0)
145 		return (error);
146 	return (record_buf(str, len));
147 }
148 
149 /* From sys/isa/pnp.c */
150 static char *
151 pnp_eisaformat(uint32_t id)
152 {
153 	uint8_t *data;
154 	static char idbuf[8];
155 	const char  hextoascii[] = "0123456789abcdef";
156 
157 	id = htole32(id);
158 	data = (uint8_t *)&id;
159 	idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
160 	idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
161 	idbuf[2] = '@' + (data[1] & 0x1f);
162 	idbuf[3] = hextoascii[(data[2] >> 4)];
163 	idbuf[4] = hextoascii[(data[2] & 0xf)];
164 	idbuf[5] = hextoascii[(data[3] >> 4)];
165 	idbuf[6] = hextoascii[(data[3] & 0xf)];
166 	idbuf[7] = 0;
167 	return (idbuf);
168 }
169 
170 struct pnp_elt
171 {
172 	int	pe_kind;	/* What kind of entry */
173 #define TYPE_SZ_MASK	0x0f
174 #define TYPE_FLAGGED	0x10	/* all f's is a wildcard */
175 #define	TYPE_INT	0x20	/* Is a number */
176 #define TYPE_PAIRED	0x40
177 #define TYPE_LE		0x80	/* Matches <= this value */
178 #define TYPE_GE		0x100	/* Matches >= this value */
179 #define TYPE_MASK	0x200	/* Specifies a mask to follow */
180 #define TYPE_U8		(1 | TYPE_INT)
181 #define TYPE_V8		(1 | TYPE_INT | TYPE_FLAGGED)
182 #define TYPE_G16	(2 | TYPE_INT | TYPE_GE)
183 #define TYPE_L16	(2 | TYPE_INT | TYPE_LE)
184 #define TYPE_M16	(2 | TYPE_INT | TYPE_MASK)
185 #define TYPE_U16	(2 | TYPE_INT)
186 #define TYPE_V16	(2 | TYPE_INT | TYPE_FLAGGED)
187 #define TYPE_U32	(4 | TYPE_INT)
188 #define TYPE_V32	(4 | TYPE_INT | TYPE_FLAGGED)
189 #define TYPE_W32	(4 | TYPE_INT | TYPE_PAIRED)
190 #define TYPE_D		7
191 #define TYPE_Z		8
192 #define TYPE_P		9
193 #define TYPE_E		10
194 #define TYPE_T		11
195 	int	pe_offset;	/* Offset within the element */
196 	char *	pe_key;		/* pnp key name */
197 	TAILQ_ENTRY(pnp_elt) next; /* Link */
198 };
199 typedef TAILQ_HEAD(pnp_head, pnp_elt) pnp_list;
200 
201 /*
202  * this function finds the data from the pnp table, as described by the
203  * the description and creates a new output (new_desc). This output table
204  * is a form that's easier for the agent that's automatically loading the
205  * modules.
206  *
207  * The format output is the simplified string from this routine in the
208  * same basic format as the pnp string, as documented in sys/module.h.
209  * First a string describing the format is output, the a count of the
210  * number of records, then each record. The format string also describes
211  * the length of each entry (though it isn't a fixed length when strings
212  * are present).
213  *
214  *	type	Output		Meaning
215  *	I	uint32_t	Integer equality comparison
216  *	J	uint32_t	Pair of uint16_t fields converted to native
217  *				byte order. The two fields both must match.
218  *	G	uint32_t	Greater than or equal to
219  *	L	uint32_t	Less than or equal to
220  *	M	uint32_t	Mask of which fields to test. Fields that
221  *				take up space increment the count. This
222  *				field must be first, and resets the count.
223  *	D	string		Description of the device this pnp info is for
224  *	Z	string		pnp string must match this
225  *	T	nothing		T fields set pnp values that must be true for
226  *				the entire table.
227  * Values are packed the same way that other values are packed in this file.
228  * Strings and int32_t's start on a 32-bit boundary and are padded with 0
229  * bytes. Objects that are smaller than uint32_t are converted, without
230  * sign extension to uint32_t to simplify parsing downstream.
231  */
232 static int
233 parse_pnp_list(const char *desc, char **new_desc, pnp_list *list)
234 {
235 	const char *walker, *ep;
236 	const char *colon, *semi;
237 	struct pnp_elt *elt;
238 	char *nd;
239 	char type[8], key[32];
240 	int off;
241 
242 	walker = desc;
243 	ep = desc + strlen(desc);
244 	off = 0;
245 	nd = *new_desc = malloc(strlen(desc) + 1);
246 	if (verbose > 1)
247 		printf("Converting %s into a list\n", desc);
248 	while (walker < ep) {
249 		colon = strchr(walker, ':');
250 		semi = strchr(walker, ';');
251 		if (semi != NULL && semi < colon)
252 			goto err;
253 		if (colon - walker > sizeof(type))
254 			goto err;
255 		strncpy(type, walker, colon - walker);
256 		type[colon - walker] = '\0';
257 		if (semi != NULL) {
258 			if (semi - colon >= sizeof(key))
259 				goto err;
260 			strncpy(key, colon + 1, semi - colon - 1);
261 			key[semi - colon - 1] = '\0';
262 			walker = semi + 1;
263 			/* Fail safe if we have spaces after ; */
264 			while (walker < ep && isspace(*walker))
265 				walker++;
266 		} else {
267 			if (strlen(colon + 1) >= sizeof(key))
268 				goto err;
269 			strcpy(key, colon + 1);
270 			walker = ep;
271 		}
272 		if (verbose > 1)
273 			printf("Found type %s for name %s\n", type, key);
274 		/* Skip pointer place holders */
275 		if (strcmp(type, "P") == 0) {
276 			off += sizeof(void *);
277 			continue;
278 		}
279 
280 		/*
281 		 * Add a node of the appropriate type
282 		 */
283 		elt = malloc(sizeof(struct pnp_elt) + strlen(key) + 1);
284 		TAILQ_INSERT_TAIL(list, elt, next);
285 		elt->pe_key = (char *)(elt + 1);
286 		elt->pe_offset = off;
287 		if (strcmp(type, "U8") == 0)
288 			elt->pe_kind = TYPE_U8;
289 		else if (strcmp(type, "V8") == 0)
290 			elt->pe_kind = TYPE_V8;
291 		else if (strcmp(type, "G16") == 0)
292 			elt->pe_kind = TYPE_G16;
293 		else if (strcmp(type, "L16") == 0)
294 			elt->pe_kind = TYPE_L16;
295 		else if (strcmp(type, "M16") == 0)
296 			elt->pe_kind = TYPE_M16;
297 		else if (strcmp(type, "U16") == 0)
298 			elt->pe_kind = TYPE_U16;
299 		else if (strcmp(type, "V16") == 0)
300 			elt->pe_kind = TYPE_V16;
301 		else if (strcmp(type, "U32") == 0)
302 			elt->pe_kind = TYPE_U32;
303 		else if (strcmp(type, "V32") == 0)
304 			elt->pe_kind = TYPE_V32;
305 		else if (strcmp(type, "W32") == 0)
306 			elt->pe_kind = TYPE_W32;
307 		else if (strcmp(type, "D") == 0)	/* description char * */
308 			elt->pe_kind = TYPE_D;
309 		else if (strcmp(type, "Z") == 0)	/* char * to match */
310 			elt->pe_kind = TYPE_Z;
311 		else if (strcmp(type, "P") == 0)	/* Pointer -- ignored */
312 			elt->pe_kind = TYPE_P;
313 		else if (strcmp(type, "E") == 0)	/* EISA PNP ID, as uint32_t */
314 			elt->pe_kind = TYPE_E;
315 		else if (strcmp(type, "T") == 0)
316 			elt->pe_kind = TYPE_T;
317 		else
318 			goto err;
319 		/*
320 		 * Maybe the rounding here needs to be more nuanced and/or somehow
321 		 * architecture specific. Fortunately, most tables in the system
322 		 * have sane ordering of types.
323 		 */
324 		if (elt->pe_kind & TYPE_INT) {
325 			elt->pe_offset = roundup2(elt->pe_offset, elt->pe_kind & TYPE_SZ_MASK);
326 			off = elt->pe_offset + (elt->pe_kind & TYPE_SZ_MASK);
327 		} else if (elt->pe_kind == TYPE_E) {
328 			/* Type E stored as Int, displays as string */
329 			elt->pe_offset = roundup2(elt->pe_offset, sizeof(uint32_t));
330 			off = elt->pe_offset + sizeof(uint32_t);
331 		} else if (elt->pe_kind == TYPE_T) {
332 			/* doesn't actually consume space in the table */
333 			off = elt->pe_offset;
334 		} else {
335 			elt->pe_offset = roundup2(elt->pe_offset, sizeof(void *));
336 			off = elt->pe_offset + sizeof(void *);
337 		}
338 		if (elt->pe_kind & TYPE_PAIRED) {
339 			char *word, *ctx;
340 
341 			for (word = strtok_r(key, "/", &ctx);
342 			     word; word = strtok_r(NULL, "/", &ctx)) {
343 				sprintf(nd, "%c:%s;", elt->pe_kind & TYPE_FLAGGED ? 'J' : 'I',
344 				    word);
345 				nd += strlen(nd);
346 			}
347 
348 		}
349 		else {
350 			if (elt->pe_kind & TYPE_FLAGGED)
351 				*nd++ = 'J';
352 			else if (elt->pe_kind & TYPE_GE)
353 				*nd++ = 'G';
354 			else if (elt->pe_kind & TYPE_LE)
355 				*nd++ = 'L';
356 			else if (elt->pe_kind & TYPE_MASK)
357 				*nd++ = 'M';
358 			else if (elt->pe_kind & TYPE_INT)
359 				*nd++ = 'I';
360 			else if (elt->pe_kind == TYPE_D)
361 				*nd++ = 'D';
362 			else if (elt->pe_kind == TYPE_Z || elt->pe_kind == TYPE_E)
363 				*nd++ = 'Z';
364 			else if (elt->pe_kind == TYPE_T)
365 				*nd++ = 'T';
366 			else
367 				errx(1, "Impossible type %x\n", elt->pe_kind);
368 			*nd++ = ':';
369 			strcpy(nd, key);
370 			nd += strlen(nd);
371 			*nd++ = ';';
372 		}
373 	}
374 	*nd++ = '\0';
375 	return (0);
376 err:
377 	errx(1, "Parse error of description string %s", desc);
378 }
379 
380 static int
381 parse_entry(struct mod_metadata *md, const char *cval,
382     struct elf_file *ef, const char *kldname)
383 {
384 	struct mod_depend mdp;
385 	struct mod_version mdv;
386 	struct mod_pnp_match_info pnp;
387 	char descr[1024];
388 	Elf_Off data;
389 	int error, i;
390 	size_t len;
391 	char *walker;
392 	void *table;
393 
394 	data = (Elf_Off)md->md_data;
395 	error = 0;
396 	record_start();
397 	switch (md->md_type) {
398 	case MDT_DEPEND:
399 		if (!dflag)
400 			break;
401 		check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
402 		printf("  depends on %s.%d (%d,%d)\n", cval,
403 		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
404 		break;
405 	case MDT_VERSION:
406 		check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
407 		if (dflag) {
408 			printf("  interface %s.%d\n", cval, mdv.mv_version);
409 		} else {
410 			record_int(MDT_VERSION);
411 			record_string(cval);
412 			record_int(mdv.mv_version);
413 			record_string(kldname);
414 		}
415 		break;
416 	case MDT_MODULE:
417 		if (dflag) {
418 			printf("  module %s\n", cval);
419 		} else {
420 			record_int(MDT_MODULE);
421 			record_string(cval);
422 			record_string(kldname);
423 		}
424 		break;
425 	case MDT_PNP_INFO:
426 		check(EF_SEG_READ_REL(ef, data, sizeof(pnp), &pnp));
427 		check(EF_SEG_READ_STRING(ef, (Elf_Off)pnp.descr, sizeof(descr), descr));
428 		descr[sizeof(descr) - 1] = '\0';
429 		if (dflag) {
430 			printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
431 			    cval, descr, pnp.num_entry, pnp.entry_len);
432 		} else {
433 			pnp_list list;
434 			struct pnp_elt *elt, *elt_tmp;
435 			char *new_descr;
436 
437 			if (verbose > 1)
438 				printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
439 				    cval, descr, pnp.num_entry, pnp.entry_len);
440 			/*
441 			 * Parse descr to weed out the chaff and to create a list
442 			 * of offsets to output.
443 			 */
444 			TAILQ_INIT(&list);
445 			parse_pnp_list(descr, &new_descr, &list);
446 			record_int(MDT_PNP_INFO);
447 			record_string(cval);
448 			record_string(new_descr);
449 			record_int(pnp.num_entry);
450 			len = pnp.num_entry * pnp.entry_len;
451 			walker = table = malloc(len);
452 			check(EF_SEG_READ_REL(ef, (Elf_Off)pnp.table, len, table));
453 
454 			/*
455 			 * Walk the list and output things. We've collapsed all the
456 			 * variant forms of the table down to just ints and strings.
457 			 */
458 			for (i = 0; i < pnp.num_entry; i++) {
459 				TAILQ_FOREACH(elt, &list, next) {
460 					uint8_t v1;
461 					uint16_t v2;
462 					uint32_t v4;
463 					int	value;
464 					char buffer[1024];
465 
466 					if (elt->pe_kind == TYPE_W32) {
467 						memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
468 						value = v4 & 0xffff;
469 						record_int(value);
470 						if (verbose > 1)
471 							printf("W32:%#x", value);
472 						value = (v4 >> 16) & 0xffff;
473 						record_int(value);
474 						if (verbose > 1)
475 							printf(":%#x;", value);
476 					} else if (elt->pe_kind & TYPE_INT) {
477 						switch (elt->pe_kind & TYPE_SZ_MASK) {
478 						case 1:
479 							memcpy(&v1, walker + elt->pe_offset, sizeof(v1));
480 							if ((elt->pe_kind & TYPE_FLAGGED) && v1 == 0xff)
481 								value = -1;
482 							else
483 								value = v1;
484 							break;
485 						case 2:
486 							memcpy(&v2, walker + elt->pe_offset, sizeof(v2));
487 							if ((elt->pe_kind & TYPE_FLAGGED) && v2 == 0xffff)
488 								value = -1;
489 							else
490 								value = v2;
491 							break;
492 						case 4:
493 							memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
494 							if ((elt->pe_kind & TYPE_FLAGGED) && v4 == 0xffffffff)
495 								value = -1;
496 							else
497 								value = v4;
498 							break;
499 						default:
500 							errx(1, "Invalid size somehow %#x", elt->pe_kind);
501 						}
502 						if (verbose > 1)
503 							printf("I:%#x;", value);
504 						record_int(value);
505 					} else if (elt->pe_kind == TYPE_T) {
506 						/* Do nothing */
507 					} else { /* E, Z or D -- P already filtered */
508 						if (elt->pe_kind == TYPE_E) {
509 							memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
510 							strcpy(buffer, pnp_eisaformat(v4));
511 						} else {
512 							char *ptr;
513 
514 							ptr = *(char **)(walker + elt->pe_offset);
515 							buffer[0] = '\0';
516 							if (ptr != NULL) {
517 								EF_SEG_READ_STRING(ef, (Elf_Off)ptr,
518 								    sizeof(buffer), buffer);
519 								buffer[sizeof(buffer) - 1] = '\0';
520 							}
521 						}
522 						if (verbose > 1)
523 							printf("%c:%s;", elt->pe_kind == TYPE_E ? 'E' : (elt->pe_kind == TYPE_Z ? 'Z' : 'D'), buffer);
524 						record_string(buffer);
525 					}
526 				}
527 				if (verbose > 1)
528 					printf("\n");
529 				walker += pnp.entry_len;
530 			}
531 			/* Now free it */
532 			TAILQ_FOREACH_SAFE(elt, &list, next, elt_tmp) {
533 				TAILQ_REMOVE(&list, elt, next);
534 				free(elt);
535 			}
536 			free(table);
537 		}
538 		break;
539 	default:
540 		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
541 	}
542 	if (!error)
543 		record_end();
544 	return (error);
545 }
546 
547 static int
548 read_kld(char *filename, char *kldname)
549 {
550 	struct mod_metadata md;
551 	struct elf_file ef;
552 	void **p;
553 	int error, eftype;
554 	long start, finish, entries, i;
555 	char cval[MAXMODNAME + 1];
556 
557 	if (verbose || dflag)
558 		printf("%s\n", filename);
559 	error = ef_open(filename, &ef, verbose);
560 	if (error != 0) {
561 		error = ef_obj_open(filename, &ef, verbose);
562 		if (error != 0) {
563 			if (verbose)
564 				warnc(error, "elf_open(%s)", filename);
565 			return (error);
566 		}
567 	}
568 	eftype = EF_GET_TYPE(&ef);
569 	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
570 		EF_CLOSE(&ef);
571 		return (0);
572 	}
573 	do {
574 		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
575 		    &entries));
576 		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
577 		    (void *)&p));
578 		/*
579 		 * Do a first pass to find MDT_MODULE.  It is required to be
580 		 * ordered first in the output linker.hints stream because it
581 		 * serves as an implicit record boundary between distinct klds
582 		 * in the stream.  Other MDTs only make sense in the context of
583 		 * a specific MDT_MODULE.
584 		 *
585 		 * Some compilers (e.g., GCC 6.4.0 xtoolchain) or binutils
586 		 * (e.g., GNU binutils 2.32 objcopy/ld.bfd) can reorder
587 		 * MODULE_METADATA set entries relative to the source ordering.
588 		 * This is permitted by the C standard; memory layout of
589 		 * file-scope objects is left implementation-defined.  There is
590 		 * no requirement that source code ordering is retained.
591 		 *
592 		 * Handle that here by taking two passes to ensure MDT_MODULE
593 		 * records are emitted to linker.hints before other MDT records
594 		 * in the same kld.
595 		 */
596 		for (i = 0; i < entries; i++) {
597 			check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
598 			    &md));
599 			check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
600 			    sizeof(cval), cval));
601 			if (md.md_type == MDT_MODULE) {
602 				parse_entry(&md, cval, &ef, kldname);
603 				break;
604 			}
605 		}
606 		if (error != 0) {
607 			warnc(error, "error while reading %s", filename);
608 			break;
609 		}
610 
611 		/*
612 		 * Second pass for all !MDT_MODULE entries.
613 		 */
614 		for (i = 0; i < entries; i++) {
615 			check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
616 			    &md));
617 			check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
618 			    sizeof(cval), cval));
619 			if (md.md_type != MDT_MODULE)
620 				parse_entry(&md, cval, &ef, kldname);
621 		}
622 		if (error != 0)
623 			warnc(error, "error while reading %s", filename);
624 		free(p);
625 	} while(0);
626 	EF_CLOSE(&ef);
627 	return (error);
628 }
629 
630 /*
631  * Create a temp file in directory root, make sure we don't
632  * overflow the buffer for the destination name
633  */
634 static FILE *
635 maketempfile(char *dest, const char *root)
636 {
637 	char *p;
638 	int n, fd;
639 
640 	p = strrchr(root, '/');
641 	n = p != NULL ? p - root + 1 : 0;
642 	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
643 	    MAXPATHLEN) {
644 		errno = ENAMETOOLONG;
645 		return (NULL);
646 	}
647 
648 	fd = mkstemp(dest);
649 	if (fd < 0)
650 		return (NULL);
651 	fchmod(fd, 0644);	/* nothing secret in the file */
652 	return (fdopen(fd, "w+"));
653 }
654 
655 static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
656 
657 static void
658 usage(void)
659 {
660 
661 	fprintf(stderr, "%s\n",
662 	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
663 	);
664 	exit(1);
665 }
666 
667 static int
668 compare(const FTSENT *const *a, const FTSENT *const *b)
669 {
670 
671 	if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
672 		return (1);
673 	if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
674 		return (-1);
675 	return (strcmp((*a)->fts_name, (*b)->fts_name));
676 }
677 
678 int
679 main(int argc, char *argv[])
680 {
681 	FTS *ftsp;
682 	FTSENT *p;
683 	int opt, fts_options, ival;
684 	struct stat sb;
685 
686 	fts_options = FTS_PHYSICAL;
687 
688 	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
689 		switch (opt) {
690 		case 'd':	/* no hint file, only print on stdout */
691 			dflag = true;
692 			break;
693 		case 'f':	/* use this name instead of linker.hints */
694 			xref_file = optarg;
695 			break;
696 		case 'v':
697 			verbose++;
698 			break;
699 		case 'R':	/* recurse on directories */
700 			fts_options |= FTS_COMFOLLOW;
701 			break;
702 		default:
703 			usage();
704 			/* NOTREACHED */
705 		}
706 	}
707 	if (argc - optind < 1)
708 		usage();
709 	argc -= optind;
710 	argv += optind;
711 
712 	if (stat(argv[0], &sb) != 0)
713 		err(1, "%s", argv[0]);
714 	if ((sb.st_mode & S_IFDIR) == 0) {
715 		errno = ENOTDIR;
716 		err(1, "%s", argv[0]);
717 	}
718 
719 	ftsp = fts_open(argv, fts_options, compare);
720 	if (ftsp == NULL)
721 		exit(1);
722 
723 	for (;;) {
724 		p = fts_read(ftsp);
725 		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
726 			/* close and rename the current hint file */
727 			fclose(fxref);
728 			fxref = NULL;
729 			if (reccnt != 0) {
730 				rename(tempname, xrefname);
731 			} else {
732 				/* didn't find any entry, ignore this file */
733 				unlink(tempname);
734 				unlink(xrefname);
735 			}
736 		}
737 		if (p == NULL)
738 			break;
739 		if (p->fts_info == FTS_D && !dflag) {
740 			/* visiting a new directory, create a new hint file */
741 			snprintf(xrefname, sizeof(xrefname), "%s/%s",
742 			    ftsp->fts_path, xref_file);
743 			fxref = maketempfile(tempname, ftsp->fts_path);
744 			if (fxref == NULL)
745 				err(1, "can't create %s", tempname);
746 			ival = 1;
747 			fwrite(&ival, sizeof(ival), 1, fxref);
748 			reccnt = 0;
749 		}
750 		/* skip non-files and separate debug files */
751 		if (p->fts_info != FTS_F)
752 			continue;
753 		if (p->fts_namelen >= 6 &&
754 		    strcmp(p->fts_name + p->fts_namelen - 6, ".debug") == 0)
755 			continue;
756 		if (p->fts_namelen >= 8 &&
757 		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
758 			continue;
759 		read_kld(p->fts_path, p->fts_name);
760 	}
761 	fts_close(ftsp);
762 	return (0);
763 }
764