xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision a64729f5077d77e13b9497cb33ecb3c82e606ee8)
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 
35 #include <sys/param.h>
36 #include <sys/endian.h>
37 #include <sys/queue.h>
38 #include <sys/stat.h>
39 #include <sys/module.h>
40 
41 #include <assert.h>
42 #include <ctype.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <fts.h>
46 #include <gelf.h>
47 #include <libelf.h>
48 #include <stdbool.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 
54 #include "ef.h"
55 
56 #define	MAXRECSIZE	(64 << 10)	/* 64k */
57 #define check(val)	if ((error = (val)) != 0) break
58 
59 static bool dflag;	/* do not create a hint file, only write on stdout */
60 static int verbose;
61 
62 static FILE *fxref;	/* current hints file */
63 static int byte_order;
64 static GElf_Ehdr ehdr;
65 static char *ehdr_filename;
66 
67 static const char *xref_file = "linker.hints";
68 
69 /*
70  * A record is stored in the static buffer recbuf before going to disk.
71  */
72 static char recbuf[MAXRECSIZE];
73 static int recpos;	/* current write position */
74 static int reccnt;	/* total record written to this file so far */
75 
76 static void
77 intalign(void)
78 {
79 
80 	recpos = roundup2(recpos, sizeof(int));
81 }
82 
83 static void
84 write_int(int val)
85 {
86 	char buf[4];
87 
88 	assert(byte_order != ELFDATANONE);
89 	if (byte_order == ELFDATA2LSB)
90 		le32enc(buf, val);
91 	else
92 		be32enc(buf, val);
93 	fwrite(buf, sizeof(buf), 1, fxref);
94 }
95 
96 static void
97 record_start(void)
98 {
99 
100 	recpos = 0;
101 	memset(recbuf, 0, MAXRECSIZE);
102 }
103 
104 static int
105 record_end(void)
106 {
107 
108 	if (recpos == 0) {
109 		/*
110 		 * Pretend to have written a record in debug mode so
111 		 * the architecture check works.
112 		 */
113 		if (dflag)
114 			reccnt++;
115 		return (0);
116 	}
117 
118 	if (reccnt == 0) {
119 		/* File version record. */
120 		write_int(1);
121 	}
122 
123 	reccnt++;
124 	intalign();
125 	write_int(recpos);
126 	return (fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0);
127 }
128 
129 static int
130 record_buf(const void *buf, size_t size)
131 {
132 
133 	if (MAXRECSIZE - recpos < size)
134 		errx(1, "record buffer overflow");
135 	memcpy(recbuf + recpos, buf, size);
136 	recpos += size;
137 	return (0);
138 }
139 
140 /*
141  * An int is stored in target byte order and aligned
142  */
143 static int
144 record_int(int val)
145 {
146 	char buf[4];
147 
148 	assert(byte_order != ELFDATANONE);
149 	if (byte_order == ELFDATA2LSB)
150 		le32enc(buf, val);
151 	else
152 		be32enc(buf, val);
153 
154 	intalign();
155 	return (record_buf(buf, sizeof(buf)));
156 }
157 
158 /*
159  * A string is stored as 1-byte length plus data, no padding
160  */
161 static int
162 record_string(const char *str)
163 {
164 	int error;
165 	size_t len;
166 	u_char val;
167 
168 	if (dflag)
169 		return (0);
170 	val = len = strlen(str);
171 	if (len > 255)
172 		errx(1, "string %s too long", str);
173 	error = record_buf(&val, sizeof(val));
174 	if (error != 0)
175 		return (error);
176 	return (record_buf(str, len));
177 }
178 
179 /* From sys/isa/pnp.c */
180 static char *
181 pnp_eisaformat(uint32_t id)
182 {
183 	uint8_t *data;
184 	static char idbuf[8];
185 	const char  hextoascii[] = "0123456789abcdef";
186 
187 	id = htole32(id);
188 	data = (uint8_t *)&id;
189 	idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
190 	idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
191 	idbuf[2] = '@' + (data[1] & 0x1f);
192 	idbuf[3] = hextoascii[(data[2] >> 4)];
193 	idbuf[4] = hextoascii[(data[2] & 0xf)];
194 	idbuf[5] = hextoascii[(data[3] >> 4)];
195 	idbuf[6] = hextoascii[(data[3] & 0xf)];
196 	idbuf[7] = 0;
197 	return (idbuf);
198 }
199 
200 struct pnp_elt
201 {
202 	int	pe_kind;	/* What kind of entry */
203 #define TYPE_SZ_MASK	0x0f
204 #define TYPE_FLAGGED	0x10	/* all f's is a wildcard */
205 #define	TYPE_INT	0x20	/* Is a number */
206 #define TYPE_PAIRED	0x40
207 #define TYPE_LE		0x80	/* Matches <= this value */
208 #define TYPE_GE		0x100	/* Matches >= this value */
209 #define TYPE_MASK	0x200	/* Specifies a mask to follow */
210 #define TYPE_U8		(1 | TYPE_INT)
211 #define TYPE_V8		(1 | TYPE_INT | TYPE_FLAGGED)
212 #define TYPE_G16	(2 | TYPE_INT | TYPE_GE)
213 #define TYPE_L16	(2 | TYPE_INT | TYPE_LE)
214 #define TYPE_M16	(2 | TYPE_INT | TYPE_MASK)
215 #define TYPE_U16	(2 | TYPE_INT)
216 #define TYPE_V16	(2 | TYPE_INT | TYPE_FLAGGED)
217 #define TYPE_U32	(4 | TYPE_INT)
218 #define TYPE_V32	(4 | TYPE_INT | TYPE_FLAGGED)
219 #define TYPE_W32	(4 | TYPE_INT | TYPE_PAIRED)
220 #define TYPE_D		7
221 #define TYPE_Z		8
222 #define TYPE_P		9
223 #define TYPE_E		10
224 #define TYPE_T		11
225 	int	pe_offset;	/* Offset within the element */
226 	char *	pe_key;		/* pnp key name */
227 	TAILQ_ENTRY(pnp_elt) next; /* Link */
228 };
229 typedef TAILQ_HEAD(pnp_head, pnp_elt) pnp_list;
230 
231 /*
232  * this function finds the data from the pnp table, as described by the
233  * description and creates a new output (new_desc). This output table
234  * is a form that's easier for the agent that's automatically loading the
235  * modules.
236  *
237  * The format output is the simplified string from this routine in the
238  * same basic format as the pnp string, as documented in sys/module.h.
239  * First a string describing the format is output, the a count of the
240  * number of records, then each record. The format string also describes
241  * the length of each entry (though it isn't a fixed length when strings
242  * are present).
243  *
244  *	type	Output		Meaning
245  *	I	uint32_t	Integer equality comparison
246  *	J	uint32_t	Pair of uint16_t fields converted to native
247  *				byte order. The two fields both must match.
248  *	G	uint32_t	Greater than or equal to
249  *	L	uint32_t	Less than or equal to
250  *	M	uint32_t	Mask of which fields to test. Fields that
251  *				take up space increment the count. This
252  *				field must be first, and resets the count.
253  *	D	string		Description of the device this pnp info is for
254  *	Z	string		pnp string must match this
255  *	T	nothing		T fields set pnp values that must be true for
256  *				the entire table.
257  * Values are packed the same way that other values are packed in this file.
258  * Strings and int32_t's start on a 32-bit boundary and are padded with 0
259  * bytes. Objects that are smaller than uint32_t are converted, without
260  * sign extension to uint32_t to simplify parsing downstream.
261  */
262 static int
263 parse_pnp_list(struct elf_file *ef, const char *desc, char **new_desc,
264     pnp_list *list)
265 {
266 	const char *walker, *ep;
267 	const char *colon, *semi;
268 	struct pnp_elt *elt;
269 	char type[8], key[32];
270 	int off;
271 	size_t new_desc_size;
272 	FILE *fp;
273 
274 	TAILQ_INIT(list);
275 	walker = desc;
276 	ep = desc + strlen(desc);
277 	off = 0;
278 	fp = open_memstream(new_desc, &new_desc_size);
279 	if (fp == NULL)
280 		err(1, "Could not open new memory stream");
281 	if (verbose > 1)
282 		printf("Converting %s into a list\n", desc);
283 	while (walker < ep) {
284 		colon = strchr(walker, ':');
285 		semi = strchr(walker, ';');
286 		if (semi != NULL && semi < colon)
287 			goto err;
288 		if (colon - walker > sizeof(type))
289 			goto err;
290 		strncpy(type, walker, colon - walker);
291 		type[colon - walker] = '\0';
292 		if (semi != NULL) {
293 			if (semi - colon >= sizeof(key))
294 				goto err;
295 			strncpy(key, colon + 1, semi - colon - 1);
296 			key[semi - colon - 1] = '\0';
297 			walker = semi + 1;
298 			/* Fail safe if we have spaces after ; */
299 			while (walker < ep && isspace(*walker))
300 				walker++;
301 		} else {
302 			if (strlen(colon + 1) >= sizeof(key))
303 				goto err;
304 			strcpy(key, colon + 1);
305 			walker = ep;
306 		}
307 		if (verbose > 1)
308 			printf("Found type %s for name %s\n", type, key);
309 		/* Skip pointer place holders */
310 		if (strcmp(type, "P") == 0) {
311 			off += elf_pointer_size(ef);
312 			continue;
313 		}
314 
315 		/*
316 		 * Add a node of the appropriate type
317 		 */
318 		elt = malloc(sizeof(struct pnp_elt) + strlen(key) + 1);
319 		TAILQ_INSERT_TAIL(list, elt, next);
320 		elt->pe_key = (char *)(elt + 1);
321 		elt->pe_offset = off;
322 		if (strcmp(type, "U8") == 0)
323 			elt->pe_kind = TYPE_U8;
324 		else if (strcmp(type, "V8") == 0)
325 			elt->pe_kind = TYPE_V8;
326 		else if (strcmp(type, "G16") == 0)
327 			elt->pe_kind = TYPE_G16;
328 		else if (strcmp(type, "L16") == 0)
329 			elt->pe_kind = TYPE_L16;
330 		else if (strcmp(type, "M16") == 0)
331 			elt->pe_kind = TYPE_M16;
332 		else if (strcmp(type, "U16") == 0)
333 			elt->pe_kind = TYPE_U16;
334 		else if (strcmp(type, "V16") == 0)
335 			elt->pe_kind = TYPE_V16;
336 		else if (strcmp(type, "U32") == 0)
337 			elt->pe_kind = TYPE_U32;
338 		else if (strcmp(type, "V32") == 0)
339 			elt->pe_kind = TYPE_V32;
340 		else if (strcmp(type, "W32") == 0)
341 			elt->pe_kind = TYPE_W32;
342 		else if (strcmp(type, "D") == 0)	/* description char * */
343 			elt->pe_kind = TYPE_D;
344 		else if (strcmp(type, "Z") == 0)	/* char * to match */
345 			elt->pe_kind = TYPE_Z;
346 		else if (strcmp(type, "P") == 0)	/* Pointer -- ignored */
347 			elt->pe_kind = TYPE_P;
348 		else if (strcmp(type, "E") == 0)	/* EISA PNP ID, as uint32_t */
349 			elt->pe_kind = TYPE_E;
350 		else if (strcmp(type, "T") == 0)
351 			elt->pe_kind = TYPE_T;
352 		else
353 			goto err;
354 		/*
355 		 * Maybe the rounding here needs to be more nuanced and/or somehow
356 		 * architecture specific. Fortunately, most tables in the system
357 		 * have sane ordering of types.
358 		 */
359 		if (elt->pe_kind & TYPE_INT) {
360 			elt->pe_offset = roundup2(elt->pe_offset, elt->pe_kind & TYPE_SZ_MASK);
361 			off = elt->pe_offset + (elt->pe_kind & TYPE_SZ_MASK);
362 		} else if (elt->pe_kind == TYPE_E) {
363 			/* Type E stored as Int, displays as string */
364 			elt->pe_offset = roundup2(elt->pe_offset, sizeof(uint32_t));
365 			off = elt->pe_offset + sizeof(uint32_t);
366 		} else if (elt->pe_kind == TYPE_T) {
367 			/* doesn't actually consume space in the table */
368 			off = elt->pe_offset;
369 		} else {
370 			elt->pe_offset = roundup2(elt->pe_offset, elf_pointer_size(ef));
371 			off = elt->pe_offset + elf_pointer_size(ef);
372 		}
373 		if (elt->pe_kind & TYPE_PAIRED) {
374 			char *word, *ctx, newtype;
375 
376 			for (word = strtok_r(key, "/", &ctx);
377 			     word; word = strtok_r(NULL, "/", &ctx)) {
378 				newtype = elt->pe_kind & TYPE_FLAGGED ? 'J' : 'I';
379 				fprintf(fp, "%c:%s;", newtype, word);
380 			}
381 		}
382 		else {
383 			char newtype;
384 
385 			if (elt->pe_kind & TYPE_FLAGGED)
386 				newtype = 'J';
387 			else if (elt->pe_kind & TYPE_GE)
388 				newtype = 'G';
389 			else if (elt->pe_kind & TYPE_LE)
390 				newtype = 'L';
391 			else if (elt->pe_kind & TYPE_MASK)
392 				newtype = 'M';
393 			else if (elt->pe_kind & TYPE_INT)
394 				newtype = 'I';
395 			else if (elt->pe_kind == TYPE_D)
396 				newtype = 'D';
397 			else if (elt->pe_kind == TYPE_Z || elt->pe_kind == TYPE_E)
398 				newtype = 'Z';
399 			else if (elt->pe_kind == TYPE_T)
400 				newtype = 'T';
401 			else
402 				errx(1, "Impossible type %x\n", elt->pe_kind);
403 			fprintf(fp, "%c:%s;", newtype, key);
404 		}
405 	}
406 	if (ferror(fp) != 0) {
407 		fclose(fp);
408 		errx(1, "Exhausted space converting description %s", desc);
409 	}
410 	if (fclose(fp) != 0)
411 		errx(1, "Failed to close memory stream");
412 	return (0);
413 err:
414 	errx(1, "Parse error of description string %s", desc);
415 }
416 
417 static void
418 free_pnp_list(char *new_desc, pnp_list *list)
419 {
420 	struct pnp_elt *elt, *elt_tmp;
421 
422 	TAILQ_FOREACH_SAFE(elt, list, next, elt_tmp) {
423 		TAILQ_REMOVE(list, elt, next);
424 		free(elt);
425 	}
426 	free(new_desc);
427 }
428 
429 static uint16_t
430 parse_16(const void *p)
431 {
432 	if (byte_order == ELFDATA2LSB)
433 		return (le16dec(p));
434 	else
435 		return (be16dec(p));
436 }
437 
438 static uint32_t
439 parse_32(const void *p)
440 {
441 	if (byte_order == ELFDATA2LSB)
442 		return (le32dec(p));
443 	else
444 		return (be32dec(p));
445 }
446 
447 static void
448 parse_pnp_entry(struct elf_file *ef, struct pnp_elt *elt, const char *walker)
449 {
450 	uint8_t v1;
451 	uint16_t v2;
452 	uint32_t v4;
453 	int	value;
454 	char buffer[1024];
455 
456 	if (elt->pe_kind == TYPE_W32) {
457 		v4 = parse_32(walker + elt->pe_offset);
458 		value = v4 & 0xffff;
459 		record_int(value);
460 		if (verbose > 1)
461 			printf("W32:%#x", value);
462 		value = (v4 >> 16) & 0xffff;
463 		record_int(value);
464 		if (verbose > 1)
465 			printf(":%#x;", value);
466 	} else if (elt->pe_kind & TYPE_INT) {
467 		switch (elt->pe_kind & TYPE_SZ_MASK) {
468 		case 1:
469 			memcpy(&v1, walker + elt->pe_offset, sizeof(v1));
470 			if ((elt->pe_kind & TYPE_FLAGGED) && v1 == 0xff)
471 				value = -1;
472 			else
473 				value = v1;
474 			break;
475 		case 2:
476 			v2 = parse_16(walker + elt->pe_offset);
477 			if ((elt->pe_kind & TYPE_FLAGGED) && v2 == 0xffff)
478 				value = -1;
479 			else
480 				value = v2;
481 			break;
482 		case 4:
483 			v4 = parse_32(walker + elt->pe_offset);
484 			if ((elt->pe_kind & TYPE_FLAGGED) && v4 == 0xffffffff)
485 				value = -1;
486 			else
487 				value = v4;
488 			break;
489 		default:
490 			errx(1, "Invalid size somehow %#x", elt->pe_kind);
491 		}
492 		if (verbose > 1)
493 			printf("I:%#x;", value);
494 		record_int(value);
495 	} else if (elt->pe_kind == TYPE_T) {
496 		/* Do nothing */
497 	} else { /* E, Z or D -- P already filtered */
498 		if (elt->pe_kind == TYPE_E) {
499 			v4 = parse_32(walker + elt->pe_offset);
500 			strcpy(buffer, pnp_eisaformat(v4));
501 		} else {
502 			GElf_Addr address;
503 
504 			address = elf_address_from_pointer(ef, walker +
505 			    elt->pe_offset);
506 			buffer[0] = '\0';
507 			if (address != 0) {
508 				elf_read_string(ef, address, buffer,
509 				    sizeof(buffer));
510 				buffer[sizeof(buffer) - 1] = '\0';
511 			}
512 		}
513 		if (verbose > 1)
514 			printf("%c:%s;", elt->pe_kind == TYPE_E ? 'E' :
515 			    (elt->pe_kind == TYPE_Z ? 'Z' : 'D'), buffer);
516 		record_string(buffer);
517 	}
518 }
519 
520 static void
521 record_pnp_info(struct elf_file *ef, const char *cval,
522     struct Gmod_pnp_match_info *pnp, const char *descr)
523 {
524 	pnp_list list;
525 	struct pnp_elt *elt;
526 	char *new_descr, *walker;
527 	void *table;
528 	size_t len;
529 	int error, i;
530 
531 	if (verbose > 1)
532 		printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
533 		    cval, descr, pnp->num_entry, pnp->entry_len);
534 
535 	/*
536 	 * Parse descr to weed out the chaff and to create a list
537 	 * of offsets to output.
538 	 */
539 	parse_pnp_list(ef, descr, &new_descr, &list);
540 	record_int(MDT_PNP_INFO);
541 	record_string(cval);
542 	record_string(new_descr);
543 	record_int(pnp->num_entry);
544 	len = pnp->num_entry * pnp->entry_len;
545 	error = elf_read_relocated_data(ef, pnp->table, len, &table);
546 	if (error != 0) {
547 		free_pnp_list(new_descr, &list);
548 		return;
549 	}
550 
551 	/*
552 	 * Walk the list and output things. We've collapsed all the
553 	 * variant forms of the table down to just ints and strings.
554 	 */
555 	walker = table;
556 	for (i = 0; i < pnp->num_entry; i++) {
557 		TAILQ_FOREACH(elt, &list, next) {
558 			parse_pnp_entry(ef, elt, walker);
559 		}
560 		if (verbose > 1)
561 			printf("\n");
562 		walker += pnp->entry_len;
563 	}
564 
565 	/* Now free it */
566 	free_pnp_list(new_descr, &list);
567 	free(table);
568 }
569 
570 static int
571 parse_entry(struct Gmod_metadata *md, const char *cval,
572     struct elf_file *ef, const char *kldname)
573 {
574 	struct Gmod_depend mdp;
575 	struct Gmod_version mdv;
576 	struct Gmod_pnp_match_info pnp;
577 	char descr[1024];
578 	GElf_Addr data;
579 	int error;
580 
581 	data = md->md_data;
582 	error = 0;
583 	record_start();
584 	switch (md->md_type) {
585 	case MDT_DEPEND:
586 		if (!dflag)
587 			break;
588 		check(elf_read_mod_depend(ef, data, &mdp));
589 		printf("  depends on %s.%d (%d,%d)\n", cval,
590 		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
591 		break;
592 	case MDT_VERSION:
593 		check(elf_read_mod_version(ef, data, &mdv));
594 		if (dflag) {
595 			printf("  interface %s.%d\n", cval, mdv.mv_version);
596 		} else {
597 			record_int(MDT_VERSION);
598 			record_string(cval);
599 			record_int(mdv.mv_version);
600 			record_string(kldname);
601 		}
602 		break;
603 	case MDT_MODULE:
604 		if (dflag) {
605 			printf("  module %s\n", cval);
606 		} else {
607 			record_int(MDT_MODULE);
608 			record_string(cval);
609 			record_string(kldname);
610 		}
611 		break;
612 	case MDT_PNP_INFO:
613 		check(elf_read_mod_pnp_match_info(ef, data, &pnp));
614 		check(elf_read_string(ef, pnp.descr, descr, sizeof(descr)));
615 		if (dflag) {
616 			printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
617 			    cval, descr, pnp.num_entry, pnp.entry_len);
618 		} else {
619 			record_pnp_info(ef, cval, &pnp, descr);
620 		}
621 		break;
622 	default:
623 		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
624 	}
625 	if (!error)
626 		record_end();
627 	return (error);
628 }
629 
630 static int
631 read_kld(char *filename, char *kldname)
632 {
633 	struct Gmod_metadata md;
634 	struct elf_file ef;
635 	GElf_Addr *p;
636 	int error;
637 	long entries, i;
638 	char cval[MAXMODNAME + 1];
639 
640 	if (verbose || dflag)
641 		printf("%s\n", filename);
642 
643 	error = elf_open_file(&ef, filename, verbose);
644 	if (error != 0)
645 		return (error);
646 
647 	if (reccnt == 0) {
648 		ehdr = ef.ef_hdr;
649 		byte_order = elf_encoding(&ef);
650 		free(ehdr_filename);
651 		ehdr_filename = strdup(filename);
652 	} else if (!elf_compatible(&ef, &ehdr)) {
653 		warnx("%s does not match architecture of %s",
654 		    filename, ehdr_filename);
655 		elf_close_file(&ef);
656 		return (EINVAL);
657 	}
658 
659 	do {
660 		check(elf_read_linker_set(&ef, MDT_SETNAME, &p, &entries));
661 
662 		/*
663 		 * Do a first pass to find MDT_MODULE.  It is required to be
664 		 * ordered first in the output linker.hints stream because it
665 		 * serves as an implicit record boundary between distinct klds
666 		 * in the stream.  Other MDTs only make sense in the context of
667 		 * a specific MDT_MODULE.
668 		 *
669 		 * Some compilers (e.g., GCC 6.4.0 xtoolchain) or binutils
670 		 * (e.g., GNU binutils 2.32 objcopy/ld.bfd) can reorder
671 		 * MODULE_METADATA set entries relative to the source ordering.
672 		 * This is permitted by the C standard; memory layout of
673 		 * file-scope objects is left implementation-defined.  There is
674 		 * no requirement that source code ordering is retained.
675 		 *
676 		 * Handle that here by taking two passes to ensure MDT_MODULE
677 		 * records are emitted to linker.hints before other MDT records
678 		 * in the same kld.
679 		 */
680 		for (i = 0; i < entries; i++) {
681 			check(elf_read_mod_metadata(&ef, p[i], &md));
682 			check(elf_read_string(&ef, md.md_cval, cval,
683 			    sizeof(cval)));
684 			if (md.md_type == MDT_MODULE) {
685 				parse_entry(&md, cval, &ef, kldname);
686 				break;
687 			}
688 		}
689 		if (error != 0) {
690 			free(p);
691 			warnc(error, "error while reading %s", filename);
692 			break;
693 		}
694 
695 		/*
696 		 * Second pass for all !MDT_MODULE entries.
697 		 */
698 		for (i = 0; i < entries; i++) {
699 			check(elf_read_mod_metadata(&ef, p[i], &md));
700 			check(elf_read_string(&ef, md.md_cval, cval,
701 			    sizeof(cval)));
702 			if (md.md_type != MDT_MODULE)
703 				parse_entry(&md, cval, &ef, kldname);
704 		}
705 		if (error != 0)
706 			warnc(error, "error while reading %s", filename);
707 		free(p);
708 	} while(0);
709 	elf_close_file(&ef);
710 	return (error);
711 }
712 
713 /*
714  * Create a temp file in directory root, make sure we don't
715  * overflow the buffer for the destination name
716  */
717 static FILE *
718 maketempfile(char *dest, const char *root)
719 {
720 	int fd;
721 
722 	if (snprintf(dest, MAXPATHLEN, "%s/lhint.XXXXXX", root) >=
723 	    MAXPATHLEN) {
724 		errno = ENAMETOOLONG;
725 		return (NULL);
726 	}
727 
728 	fd = mkstemp(dest);
729 	if (fd < 0)
730 		return (NULL);
731 	fchmod(fd, 0644);	/* nothing secret in the file */
732 	return (fdopen(fd, "w+"));
733 }
734 
735 static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
736 
737 static void
738 usage(void)
739 {
740 
741 	fprintf(stderr, "%s\n",
742 	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
743 	);
744 	exit(1);
745 }
746 
747 static int
748 #if defined(__linux__) || defined(__APPLE__)
749 compare(const FTSENT **a, const FTSENT **b)
750 #else
751 compare(const FTSENT *const *a, const FTSENT *const *b)
752 #endif
753 {
754 
755 	if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
756 		return (1);
757 	if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
758 		return (-1);
759 	return (strcmp((*a)->fts_name, (*b)->fts_name));
760 }
761 
762 int
763 main(int argc, char *argv[])
764 {
765 	FTS *ftsp;
766 	FTSENT *p;
767 	char *dot = NULL;
768 	int opt, fts_options;
769 	struct stat sb;
770 
771 	fts_options = FTS_PHYSICAL;
772 
773 	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
774 		switch (opt) {
775 		case 'd':	/* no hint file, only print on stdout */
776 			dflag = true;
777 			break;
778 		case 'f':	/* use this name instead of linker.hints */
779 			xref_file = optarg;
780 			break;
781 		case 'v':
782 			verbose++;
783 			break;
784 		case 'R':	/* recurse on directories */
785 			fts_options |= FTS_COMFOLLOW;
786 			break;
787 		default:
788 			usage();
789 			/* NOTREACHED */
790 		}
791 	}
792 	if (argc - optind < 1)
793 		usage();
794 	argc -= optind;
795 	argv += optind;
796 
797 	if (stat(argv[0], &sb) != 0)
798 		err(1, "%s", argv[0]);
799 	if ((sb.st_mode & S_IFDIR) == 0 && !dflag) {
800 		errno = ENOTDIR;
801 		err(1, "%s", argv[0]);
802 	}
803 
804 	if (elf_version(EV_CURRENT) == EV_NONE)
805 		errx(1, "unsupported libelf");
806 
807 	ftsp = fts_open(argv, fts_options, compare);
808 	if (ftsp == NULL)
809 		exit(1);
810 
811 	for (;;) {
812 		p = fts_read(ftsp);
813 		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
814 			/* close and rename the current hint file */
815 			fclose(fxref);
816 			fxref = NULL;
817 			if (reccnt != 0) {
818 				rename(tempname, xrefname);
819 			} else {
820 				/* didn't find any entry, ignore this file */
821 				unlink(tempname);
822 				unlink(xrefname);
823 			}
824 		}
825 		if (p == NULL)
826 			break;
827 		if (p->fts_info == FTS_D && !dflag) {
828 			/* visiting a new directory, create a new hint file */
829 			snprintf(xrefname, sizeof(xrefname), "%s/%s",
830 			    ftsp->fts_path, xref_file);
831 			fxref = maketempfile(tempname, ftsp->fts_path);
832 			if (fxref == NULL)
833 				err(1, "can't create %s", tempname);
834 			byte_order = ELFDATANONE;
835 			reccnt = 0;
836 		}
837 		/* skip non-files.. */
838 		if (p->fts_info != FTS_F)
839 			continue;
840 		/*
841 		 * Skip files that generate errors like .debug, .symbol and .pkgsave
842 		 * by generally skipping all files which neither end with ".ko"
843 		 * nor have no dots in the name (like kernel).
844 		 */
845 		dot = strrchr(p->fts_name, '.');
846 		if (dot != NULL && strcmp(dot, ".ko") != 0)
847 			continue;
848 		read_kld(p->fts_path, p->fts_name);
849 	}
850 	fts_close(ftsp);
851 	return (0);
852 }
853