xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 10ff414c14eef433d8157f0c17904d740693933b)
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 type[8], key[32];
239 	int off;
240 	size_t new_desc_size;
241 	FILE *fp;
242 
243 	walker = desc;
244 	ep = desc + strlen(desc);
245 	off = 0;
246 	fp = open_memstream(new_desc, &new_desc_size);
247 	if (fp == NULL)
248 		err(1, "Could not open new memory stream");
249 	if (verbose > 1)
250 		printf("Converting %s into a list\n", desc);
251 	while (walker < ep) {
252 		colon = strchr(walker, ':');
253 		semi = strchr(walker, ';');
254 		if (semi != NULL && semi < colon)
255 			goto err;
256 		if (colon - walker > sizeof(type))
257 			goto err;
258 		strncpy(type, walker, colon - walker);
259 		type[colon - walker] = '\0';
260 		if (semi != NULL) {
261 			if (semi - colon >= sizeof(key))
262 				goto err;
263 			strncpy(key, colon + 1, semi - colon - 1);
264 			key[semi - colon - 1] = '\0';
265 			walker = semi + 1;
266 			/* Fail safe if we have spaces after ; */
267 			while (walker < ep && isspace(*walker))
268 				walker++;
269 		} else {
270 			if (strlen(colon + 1) >= sizeof(key))
271 				goto err;
272 			strcpy(key, colon + 1);
273 			walker = ep;
274 		}
275 		if (verbose > 1)
276 			printf("Found type %s for name %s\n", type, key);
277 		/* Skip pointer place holders */
278 		if (strcmp(type, "P") == 0) {
279 			off += sizeof(void *);
280 			continue;
281 		}
282 
283 		/*
284 		 * Add a node of the appropriate type
285 		 */
286 		elt = malloc(sizeof(struct pnp_elt) + strlen(key) + 1);
287 		TAILQ_INSERT_TAIL(list, elt, next);
288 		elt->pe_key = (char *)(elt + 1);
289 		elt->pe_offset = off;
290 		if (strcmp(type, "U8") == 0)
291 			elt->pe_kind = TYPE_U8;
292 		else if (strcmp(type, "V8") == 0)
293 			elt->pe_kind = TYPE_V8;
294 		else if (strcmp(type, "G16") == 0)
295 			elt->pe_kind = TYPE_G16;
296 		else if (strcmp(type, "L16") == 0)
297 			elt->pe_kind = TYPE_L16;
298 		else if (strcmp(type, "M16") == 0)
299 			elt->pe_kind = TYPE_M16;
300 		else if (strcmp(type, "U16") == 0)
301 			elt->pe_kind = TYPE_U16;
302 		else if (strcmp(type, "V16") == 0)
303 			elt->pe_kind = TYPE_V16;
304 		else if (strcmp(type, "U32") == 0)
305 			elt->pe_kind = TYPE_U32;
306 		else if (strcmp(type, "V32") == 0)
307 			elt->pe_kind = TYPE_V32;
308 		else if (strcmp(type, "W32") == 0)
309 			elt->pe_kind = TYPE_W32;
310 		else if (strcmp(type, "D") == 0)	/* description char * */
311 			elt->pe_kind = TYPE_D;
312 		else if (strcmp(type, "Z") == 0)	/* char * to match */
313 			elt->pe_kind = TYPE_Z;
314 		else if (strcmp(type, "P") == 0)	/* Pointer -- ignored */
315 			elt->pe_kind = TYPE_P;
316 		else if (strcmp(type, "E") == 0)	/* EISA PNP ID, as uint32_t */
317 			elt->pe_kind = TYPE_E;
318 		else if (strcmp(type, "T") == 0)
319 			elt->pe_kind = TYPE_T;
320 		else
321 			goto err;
322 		/*
323 		 * Maybe the rounding here needs to be more nuanced and/or somehow
324 		 * architecture specific. Fortunately, most tables in the system
325 		 * have sane ordering of types.
326 		 */
327 		if (elt->pe_kind & TYPE_INT) {
328 			elt->pe_offset = roundup2(elt->pe_offset, elt->pe_kind & TYPE_SZ_MASK);
329 			off = elt->pe_offset + (elt->pe_kind & TYPE_SZ_MASK);
330 		} else if (elt->pe_kind == TYPE_E) {
331 			/* Type E stored as Int, displays as string */
332 			elt->pe_offset = roundup2(elt->pe_offset, sizeof(uint32_t));
333 			off = elt->pe_offset + sizeof(uint32_t);
334 		} else if (elt->pe_kind == TYPE_T) {
335 			/* doesn't actually consume space in the table */
336 			off = elt->pe_offset;
337 		} else {
338 			elt->pe_offset = roundup2(elt->pe_offset, sizeof(void *));
339 			off = elt->pe_offset + sizeof(void *);
340 		}
341 		if (elt->pe_kind & TYPE_PAIRED) {
342 			char *word, *ctx, newtype;
343 
344 			for (word = strtok_r(key, "/", &ctx);
345 			     word; word = strtok_r(NULL, "/", &ctx)) {
346 				newtype = elt->pe_kind & TYPE_FLAGGED ? 'J' : 'I';
347 				fprintf(fp, "%c:%s;", newtype, word);
348 			}
349 		}
350 		else {
351 			char newtype;
352 
353 			if (elt->pe_kind & TYPE_FLAGGED)
354 				newtype = 'J';
355 			else if (elt->pe_kind & TYPE_GE)
356 				newtype = 'G';
357 			else if (elt->pe_kind & TYPE_LE)
358 				newtype = 'L';
359 			else if (elt->pe_kind & TYPE_MASK)
360 				newtype = 'M';
361 			else if (elt->pe_kind & TYPE_INT)
362 				newtype = 'I';
363 			else if (elt->pe_kind == TYPE_D)
364 				newtype = 'D';
365 			else if (elt->pe_kind == TYPE_Z || elt->pe_kind == TYPE_E)
366 				newtype = 'Z';
367 			else if (elt->pe_kind == TYPE_T)
368 				newtype = 'T';
369 			else
370 				errx(1, "Impossible type %x\n", elt->pe_kind);
371 			fprintf(fp, "%c:%s;", newtype, key);
372 		}
373 	}
374 	if (ferror(fp) != 0) {
375 		fclose(fp);
376 		errx(1, "Exhausted space converting description %s", desc);
377 	}
378 	if (fclose(fp) != 0)
379 		errx(1, "Failed to close memory stream");
380 	return (0);
381 err:
382 	errx(1, "Parse error of description string %s", desc);
383 }
384 
385 static int
386 parse_entry(struct mod_metadata *md, const char *cval,
387     struct elf_file *ef, const char *kldname)
388 {
389 	struct mod_depend mdp;
390 	struct mod_version mdv;
391 	struct mod_pnp_match_info pnp;
392 	char descr[1024];
393 	Elf_Off data;
394 	int error, i;
395 	size_t len;
396 	char *walker;
397 	void *table;
398 
399 	data = (Elf_Off)md->md_data;
400 	error = 0;
401 	record_start();
402 	switch (md->md_type) {
403 	case MDT_DEPEND:
404 		if (!dflag)
405 			break;
406 		check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
407 		printf("  depends on %s.%d (%d,%d)\n", cval,
408 		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
409 		break;
410 	case MDT_VERSION:
411 		check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
412 		if (dflag) {
413 			printf("  interface %s.%d\n", cval, mdv.mv_version);
414 		} else {
415 			record_int(MDT_VERSION);
416 			record_string(cval);
417 			record_int(mdv.mv_version);
418 			record_string(kldname);
419 		}
420 		break;
421 	case MDT_MODULE:
422 		if (dflag) {
423 			printf("  module %s\n", cval);
424 		} else {
425 			record_int(MDT_MODULE);
426 			record_string(cval);
427 			record_string(kldname);
428 		}
429 		break;
430 	case MDT_PNP_INFO:
431 		check(EF_SEG_READ_REL(ef, data, sizeof(pnp), &pnp));
432 		check(EF_SEG_READ_STRING(ef, (Elf_Off)pnp.descr, sizeof(descr), descr));
433 		descr[sizeof(descr) - 1] = '\0';
434 		if (dflag) {
435 			printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
436 			    cval, descr, pnp.num_entry, pnp.entry_len);
437 		} else {
438 			pnp_list list;
439 			struct pnp_elt *elt, *elt_tmp;
440 			char *new_descr;
441 
442 			if (verbose > 1)
443 				printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
444 				    cval, descr, pnp.num_entry, pnp.entry_len);
445 			/*
446 			 * Parse descr to weed out the chaff and to create a list
447 			 * of offsets to output.
448 			 */
449 			TAILQ_INIT(&list);
450 			parse_pnp_list(descr, &new_descr, &list);
451 			record_int(MDT_PNP_INFO);
452 			record_string(cval);
453 			record_string(new_descr);
454 			record_int(pnp.num_entry);
455 			len = pnp.num_entry * pnp.entry_len;
456 			walker = table = malloc(len);
457 			check(EF_SEG_READ_REL(ef, (Elf_Off)pnp.table, len, table));
458 
459 			/*
460 			 * Walk the list and output things. We've collapsed all the
461 			 * variant forms of the table down to just ints and strings.
462 			 */
463 			for (i = 0; i < pnp.num_entry; i++) {
464 				TAILQ_FOREACH(elt, &list, next) {
465 					uint8_t v1;
466 					uint16_t v2;
467 					uint32_t v4;
468 					int	value;
469 					char buffer[1024];
470 
471 					if (elt->pe_kind == TYPE_W32) {
472 						memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
473 						value = v4 & 0xffff;
474 						record_int(value);
475 						if (verbose > 1)
476 							printf("W32:%#x", value);
477 						value = (v4 >> 16) & 0xffff;
478 						record_int(value);
479 						if (verbose > 1)
480 							printf(":%#x;", value);
481 					} else if (elt->pe_kind & TYPE_INT) {
482 						switch (elt->pe_kind & TYPE_SZ_MASK) {
483 						case 1:
484 							memcpy(&v1, walker + elt->pe_offset, sizeof(v1));
485 							if ((elt->pe_kind & TYPE_FLAGGED) && v1 == 0xff)
486 								value = -1;
487 							else
488 								value = v1;
489 							break;
490 						case 2:
491 							memcpy(&v2, walker + elt->pe_offset, sizeof(v2));
492 							if ((elt->pe_kind & TYPE_FLAGGED) && v2 == 0xffff)
493 								value = -1;
494 							else
495 								value = v2;
496 							break;
497 						case 4:
498 							memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
499 							if ((elt->pe_kind & TYPE_FLAGGED) && v4 == 0xffffffff)
500 								value = -1;
501 							else
502 								value = v4;
503 							break;
504 						default:
505 							errx(1, "Invalid size somehow %#x", elt->pe_kind);
506 						}
507 						if (verbose > 1)
508 							printf("I:%#x;", value);
509 						record_int(value);
510 					} else if (elt->pe_kind == TYPE_T) {
511 						/* Do nothing */
512 					} else { /* E, Z or D -- P already filtered */
513 						if (elt->pe_kind == TYPE_E) {
514 							memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
515 							strcpy(buffer, pnp_eisaformat(v4));
516 						} else {
517 							char *ptr;
518 
519 							ptr = *(char **)(walker + elt->pe_offset);
520 							buffer[0] = '\0';
521 							if (ptr != NULL) {
522 								EF_SEG_READ_STRING(ef, (Elf_Off)ptr,
523 								    sizeof(buffer), buffer);
524 								buffer[sizeof(buffer) - 1] = '\0';
525 							}
526 						}
527 						if (verbose > 1)
528 							printf("%c:%s;", elt->pe_kind == TYPE_E ? 'E' : (elt->pe_kind == TYPE_Z ? 'Z' : 'D'), buffer);
529 						record_string(buffer);
530 					}
531 				}
532 				if (verbose > 1)
533 					printf("\n");
534 				walker += pnp.entry_len;
535 			}
536 			/* Now free it */
537 			TAILQ_FOREACH_SAFE(elt, &list, next, elt_tmp) {
538 				TAILQ_REMOVE(&list, elt, next);
539 				free(elt);
540 			}
541 			free(table);
542 		}
543 		break;
544 	default:
545 		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
546 	}
547 	if (!error)
548 		record_end();
549 	return (error);
550 }
551 
552 static int
553 read_kld(char *filename, char *kldname)
554 {
555 	struct mod_metadata md;
556 	struct elf_file ef;
557 	void **p;
558 	int error, eftype;
559 	long start, finish, entries, i;
560 	char cval[MAXMODNAME + 1];
561 
562 	if (verbose || dflag)
563 		printf("%s\n", filename);
564 	error = ef_open(filename, &ef, verbose);
565 	if (error != 0) {
566 		error = ef_obj_open(filename, &ef, verbose);
567 		if (error != 0) {
568 			if (verbose)
569 				warnc(error, "elf_open(%s)", filename);
570 			return (error);
571 		}
572 	}
573 	eftype = EF_GET_TYPE(&ef);
574 	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
575 		EF_CLOSE(&ef);
576 		return (0);
577 	}
578 	do {
579 		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
580 		    &entries));
581 		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
582 		    (void *)&p));
583 		/*
584 		 * Do a first pass to find MDT_MODULE.  It is required to be
585 		 * ordered first in the output linker.hints stream because it
586 		 * serves as an implicit record boundary between distinct klds
587 		 * in the stream.  Other MDTs only make sense in the context of
588 		 * a specific MDT_MODULE.
589 		 *
590 		 * Some compilers (e.g., GCC 6.4.0 xtoolchain) or binutils
591 		 * (e.g., GNU binutils 2.32 objcopy/ld.bfd) can reorder
592 		 * MODULE_METADATA set entries relative to the source ordering.
593 		 * This is permitted by the C standard; memory layout of
594 		 * file-scope objects is left implementation-defined.  There is
595 		 * no requirement that source code ordering is retained.
596 		 *
597 		 * Handle that here by taking two passes to ensure MDT_MODULE
598 		 * records are emitted to linker.hints before other MDT records
599 		 * in the same kld.
600 		 */
601 		for (i = 0; i < entries; i++) {
602 			check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
603 			    &md));
604 			check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
605 			    sizeof(cval), cval));
606 			if (md.md_type == MDT_MODULE) {
607 				parse_entry(&md, cval, &ef, kldname);
608 				break;
609 			}
610 		}
611 		if (error != 0) {
612 			warnc(error, "error while reading %s", filename);
613 			break;
614 		}
615 
616 		/*
617 		 * Second pass for all !MDT_MODULE entries.
618 		 */
619 		for (i = 0; i < entries; i++) {
620 			check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
621 			    &md));
622 			check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
623 			    sizeof(cval), cval));
624 			if (md.md_type != MDT_MODULE)
625 				parse_entry(&md, cval, &ef, kldname);
626 		}
627 		if (error != 0)
628 			warnc(error, "error while reading %s", filename);
629 		free(p);
630 	} while(0);
631 	EF_CLOSE(&ef);
632 	return (error);
633 }
634 
635 /*
636  * Create a temp file in directory root, make sure we don't
637  * overflow the buffer for the destination name
638  */
639 static FILE *
640 maketempfile(char *dest, const char *root)
641 {
642 	char *p;
643 	int n, fd;
644 
645 	p = strrchr(root, '/');
646 	n = p != NULL ? p - root + 1 : 0;
647 	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
648 	    MAXPATHLEN) {
649 		errno = ENAMETOOLONG;
650 		return (NULL);
651 	}
652 
653 	fd = mkstemp(dest);
654 	if (fd < 0)
655 		return (NULL);
656 	fchmod(fd, 0644);	/* nothing secret in the file */
657 	return (fdopen(fd, "w+"));
658 }
659 
660 static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
661 
662 static void
663 usage(void)
664 {
665 
666 	fprintf(stderr, "%s\n",
667 	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
668 	);
669 	exit(1);
670 }
671 
672 static int
673 compare(const FTSENT *const *a, const FTSENT *const *b)
674 {
675 
676 	if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
677 		return (1);
678 	if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
679 		return (-1);
680 	return (strcmp((*a)->fts_name, (*b)->fts_name));
681 }
682 
683 int
684 main(int argc, char *argv[])
685 {
686 	FTS *ftsp;
687 	FTSENT *p;
688 	int opt, fts_options, ival;
689 	struct stat sb;
690 
691 	fts_options = FTS_PHYSICAL;
692 
693 	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
694 		switch (opt) {
695 		case 'd':	/* no hint file, only print on stdout */
696 			dflag = true;
697 			break;
698 		case 'f':	/* use this name instead of linker.hints */
699 			xref_file = optarg;
700 			break;
701 		case 'v':
702 			verbose++;
703 			break;
704 		case 'R':	/* recurse on directories */
705 			fts_options |= FTS_COMFOLLOW;
706 			break;
707 		default:
708 			usage();
709 			/* NOTREACHED */
710 		}
711 	}
712 	if (argc - optind < 1)
713 		usage();
714 	argc -= optind;
715 	argv += optind;
716 
717 	if (stat(argv[0], &sb) != 0)
718 		err(1, "%s", argv[0]);
719 	if ((sb.st_mode & S_IFDIR) == 0 && !dflag) {
720 		errno = ENOTDIR;
721 		err(1, "%s", argv[0]);
722 	}
723 
724 	ftsp = fts_open(argv, fts_options, compare);
725 	if (ftsp == NULL)
726 		exit(1);
727 
728 	for (;;) {
729 		p = fts_read(ftsp);
730 		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
731 			/* close and rename the current hint file */
732 			fclose(fxref);
733 			fxref = NULL;
734 			if (reccnt != 0) {
735 				rename(tempname, xrefname);
736 			} else {
737 				/* didn't find any entry, ignore this file */
738 				unlink(tempname);
739 				unlink(xrefname);
740 			}
741 		}
742 		if (p == NULL)
743 			break;
744 		if (p->fts_info == FTS_D && !dflag) {
745 			/* visiting a new directory, create a new hint file */
746 			snprintf(xrefname, sizeof(xrefname), "%s/%s",
747 			    ftsp->fts_path, xref_file);
748 			fxref = maketempfile(tempname, ftsp->fts_path);
749 			if (fxref == NULL)
750 				err(1, "can't create %s", tempname);
751 			ival = 1;
752 			fwrite(&ival, sizeof(ival), 1, fxref);
753 			reccnt = 0;
754 		}
755 		/* skip non-files and separate debug files */
756 		if (p->fts_info != FTS_F)
757 			continue;
758 		if (p->fts_namelen >= 6 &&
759 		    strcmp(p->fts_name + p->fts_namelen - 6, ".debug") == 0)
760 			continue;
761 		if (p->fts_namelen >= 8 &&
762 		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
763 			continue;
764 		read_kld(p->fts_path, p->fts_name);
765 	}
766 	fts_close(ftsp);
767 	return (0);
768 }
769