Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1993,1995 Paul Kranenburg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef lint
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <a.out.h>
#include <ctype.h>
#include <dirent.h>
#include <elf-hints.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/link_aout.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ldconfig.h"
#include "shlib.h"
#include "support.h"

#if DEBUG
/* test */
#undef _PATH_LD_HINTS
#define _PATH_LD_HINTS		"./ld.so.hints"
#undef _PATH_ELF_HINTS
#define _PATH_ELF_HINTS		"./ld-elf.so.hints"
#endif

#define	_PATH_LD32_HINTS	"/var/run/ld32.so.hints"
#define	_PATH_ELF32_HINTS	"/var/run/ld-elf32.so.hints"
#define	_PATH_ELFSOFT_HINTS	"/var/run/ld-elf-soft.so.hints"

#undef major
#undef minor

static int			verbose;
static int			nostd;
static int			justread;
static int			merge;
static int			rescan;
static const char		*hints_file;

struct shlib_list {
	/* Internal list of shared libraries found */
	char			*name;
	char			*path;
	int			dewey[MAXDEWEY];
	int			ndewey;
#define major dewey[0]
#define minor dewey[1]
	struct shlib_list	*next;
};

static struct shlib_list	*shlib_head = NULL, **shlib_tail = &shlib_head;
static char			*dir_list;

static int		buildhints(void);
static int		dodir(char *, int);
int			dofile(char *, int);
static void		enter(char *, char *, char *, int *, int);
static void		listhints(void);
static int		readhints(void);
static void		usage(void);

/*
 * Note on aout/a.out support.
 * To properly support shared libraries for compat2x, which are a.out, we need
 * to support a.out here.  As of 2013, bug reports are still coming in for this
 * feature (on amd64 no less), so we know it is still in use.
 */

int
main(int argc, char **argv)
{
	int		i, c;
	int		rval = 0;
	int		is_aout = 0;
	int		is_32 = 0;
	int		is_soft = 0;

	while (argc > 1) {
		if (strcmp(argv[1], "-aout") == 0) {
			warnx("aout support is deprecated");
			is_aout = 1;
			argc--;
			argv++;
		} else if (strcmp(argv[1], "-elf") == 0) {
			is_aout = 0;
			argc--;
			argv++;
		} else if (strcmp(argv[1], "-32") == 0) {
			is_32 = 1;
			argc--;
			argv++;
		} else if (strcmp(argv[1], "-soft") == 0) {
			is_soft = 1;
			argc--;
			argv++;
		} else {
			break;
		}
	}

	if (is_soft)
		hints_file = _PATH_ELFSOFT_HINTS;	/* Never will have a.out softfloat */
	else if (is_32)
		hints_file = is_aout ? _PATH_LD32_HINTS : _PATH_ELF32_HINTS;
	else
		hints_file = is_aout ? _PATH_LD_HINTS : _PATH_ELF_HINTS;
	if (argc == 1)
		rescan = 1;
	else while((c = getopt(argc, argv, "Rf:imrsv")) != -1) {
		switch (c) {
		case 'R':
			rescan = 1;
			break;
		case 'f':
			hints_file = optarg;
			break;
		case 'i':
			insecure = 1;
			break;
		case 'm':
			merge = 1;
			break;
		case 'r':
			justread = 1;
			break;
		case 's':
			nostd = 1;
			break;
		case 'v':
			verbose = 1;
			break;
		default:
			usage();
			break;
		}
	}

	if (!is_aout) {
		if (justread)
			list_elf_hints(hints_file);
		else
			update_elf_hints(hints_file, argc - optind,
			    argv + optind, merge || rescan);
		return 0;
	}

	/* Here begins the aout libs processing */
	dir_list = strdup("");

	if (justread || merge || rescan) {
		if ((rval = readhints()) != 0)
			return rval;
	}

	if (!nostd && !merge && !rescan)
		std_search_path();

	/* Add any directories/files from the command line */
	if (!justread) {
		for (i = optind; i < argc; i++) {
			struct stat stbuf;

			if (stat(argv[i], &stbuf) == -1) {
				warn("%s", argv[i]);
				rval = -1;
			} else if (strcmp(argv[i], "/usr/lib") == 0) {
				warnx("WARNING! '%s' can not be used", argv[i]);
				rval = -1;
			} else {
				/*
				 * See if this is a directory-containing
				 * file instead of a directory
				 */
				if (S_ISREG(stbuf.st_mode))
					rval |= dofile(argv[i], 0);
				else
					add_search_path(argv[i]);
			}
		}
	}

	for (i = 0; i < n_search_dirs; i++) {
		char *cp = concat(dir_list, *dir_list?":":"", search_dirs[i]);
		free(dir_list);
		dir_list = cp;
	}

	if (justread) {
		listhints();
		return 0;
	}

	for (i = 0; i < n_search_dirs; i++)
		rval |= dodir(search_dirs[i], 1);

	rval |= buildhints();

	return rval;
}

static void
usage(void)
{
	fprintf(stderr,
	"usage: ldconfig [-32] [-aout | -elf] [-Rimrsv] [-f hints_file] [directory | file ...]\n");
	exit(1);
}
	
int
dofile(char *fname, int silent)
{
	FILE *hfp;
	char buf[MAXPATHLEN];
	int rval = 0;
	char *cp, *sp;

	if ((hfp = fopen(fname, "r")) == NULL) {
		warn("%s", fname);
		return -1;
	}

	while (fgets(buf, sizeof(buf), hfp)) {
		cp = buf;
		while (isspace(*cp))
			cp++;
		if (*cp == '#' || *cp == '\0')
			continue;
		sp = cp;
		while (!isspace(*cp) && *cp != '\0')
			cp++;

		if (*cp != '\n') {
			*cp = '\0';
			warnx("%s: trailing characters ignored", sp);
		}

		*cp = '\0';

		rval |= dodir(sp, silent);
	}

	(void)fclose(hfp);
	return rval;
}

int
dodir(char *dir, int silent)
{
	DIR		*dd;
	struct dirent	*dp;
	char		name[MAXPATHLEN];
	int		dewey[MAXDEWEY], ndewey;

	if ((dd = opendir(dir)) == NULL) {
		if (silent && errno == ENOENT)	/* Ignore the error */
			return 0;
		warn("%s", dir);
		return -1;
	}

	while ((dp = readdir(dd)) != NULL) {
		int n;
		char *cp;

		/* Check for `lib' prefix */
		if (dp->d_name[0] != 'l' ||
		    dp->d_name[1] != 'i' ||
		    dp->d_name[2] != 'b')
			continue;

		/* Copy the entry minus prefix */
		(void)strcpy(name, dp->d_name + 3);
		n = strlen(name);
		if (n < 4)
			continue;

		/* Find ".so." in name */
		for (cp = name + n - 4; cp > name; --cp) {
			if (cp[0] == '.' &&
			    cp[1] == 's' &&
			    cp[2] == 'o' &&
			    cp[3] == '.')
				break;
		}
		if (cp <= name)
			continue;

		*cp = '\0';
		if (!isdigit(*(cp+4)))
			continue;

		bzero((caddr_t)dewey, sizeof(dewey));
		ndewey = getdewey(dewey, cp + 4);
		if (ndewey < 2)
			continue;
		enter(dir, dp->d_name, name, dewey, ndewey);
	}

	closedir(dd);
	return 0;
}

static void
enter(char *dir, char *file, char *name, int dewey[], int ndewey)
{
	struct shlib_list	*shp;

	for (shp = shlib_head; shp; shp = shp->next) {
		if (strcmp(name, shp->name) != 0 || major != shp->major)
			continue;

		/* Name matches existing entry */
		if (cmpndewey(dewey, ndewey, shp->dewey, shp->ndewey) > 0) {

			/* Update this entry with higher versioned lib */
			if (verbose)
				printf("Updating lib%s.%d.%d to %s/%s\n",
					shp->name, shp->major, shp->minor,
					dir, file);

			free(shp->name);
			shp->name = strdup(name);
			free(shp->path);
			shp->path = concat(dir, "/", file);
			bcopy(dewey, shp->dewey, sizeof(shp->dewey));
			shp->ndewey = ndewey;
		}
		break;
	}

	if (shp)
		/* Name exists: older version or just updated */
		return;

	/* Allocate new list element */
	if (verbose)
		printf("Adding %s/%s\n", dir, file);

	shp = (struct shlib_list *)xmalloc(sizeof *shp);
	shp->name = strdup(name);
	shp->path = concat(dir, "/", file);
	bcopy(dewey, shp->dewey, sizeof(shp->dewey));
	shp->ndewey = ndewey;
	shp->next = NULL;

	*shlib_tail = shp;
	shlib_tail = &shp->next;
}


static int
hinthash(char *cp, int vmajor)
{
	int	k = 0;

	while (*cp)
		k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;

	k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;

	return k;
}

int
buildhints(void)
{
	struct hints_header	hdr;
	struct hints_bucket	*blist;
	struct shlib_list	*shp;
	char			*strtab;
	int			i, n, str_index = 0;
	int			strtab_sz = 0;	/* Total length of strings */
	int			nhints = 0;	/* Total number of hints */
	int			fd;
	char			*tmpfilename;

	for (shp = shlib_head; shp; shp = shp->next) {
		strtab_sz += 1 + strlen(shp->name);
		strtab_sz += 1 + strlen(shp->path);
		nhints++;
	}

	/* Fill hints file header */
	hdr.hh_magic = HH_MAGIC;
	hdr.hh_version = LD_HINTS_VERSION_2;
	hdr.hh_nbucket = 1 * nhints;
	n = hdr.hh_nbucket * sizeof(struct hints_bucket);
	hdr.hh_hashtab = sizeof(struct hints_header);
	hdr.hh_strtab = hdr.hh_hashtab + n;
	hdr.hh_dirlist = strtab_sz;
	strtab_sz += 1 + strlen(dir_list);
	hdr.hh_strtab_sz = strtab_sz;
	hdr.hh_ehints = hdr.hh_strtab + hdr.hh_strtab_sz;

	if (verbose)
		printf("Totals: entries %d, buckets %ld, string size %d\n",
			nhints, (long)hdr.hh_nbucket, strtab_sz);

	/* Allocate buckets and string table */
	blist = (struct hints_bucket *)xmalloc(n);
	bzero((char *)blist, n);
	for (i = 0; i < hdr.hh_nbucket; i++)
		/* Empty all buckets */
		blist[i].hi_next = -1;

	strtab = (char *)xmalloc(strtab_sz);

	/* Enter all */
	for (shp = shlib_head; shp; shp = shp->next) {
		struct hints_bucket	*bp;

		bp = blist +
		  (hinthash(shp->name, shp->major) % hdr.hh_nbucket);

		if (bp->hi_pathx) {
			int	j;

			for (j = 0; j < hdr.hh_nbucket; j++) {
				if (blist[j].hi_pathx == 0)
					break;
			}
			if (j == hdr.hh_nbucket) {
				warnx("bummer!");
				return -1;
			}
			while (bp->hi_next != -1)
				bp = &blist[bp->hi_next];
			bp->hi_next = j;
			bp = blist + j;
		}

		/* Insert strings in string table */
		bp->hi_namex = str_index;
		strcpy(strtab + str_index, shp->name);
		str_index += 1 + strlen(shp->name);

		bp->hi_pathx = str_index;
		strcpy(strtab + str_index, shp->path);
		str_index += 1 + strlen(shp->path);

		/* Copy versions */
		bcopy(shp->dewey, bp->hi_dewey, sizeof(bp->hi_dewey));
		bp->hi_ndewey = shp->ndewey;
	}

	/* Copy search directories */
	strcpy(strtab + str_index, dir_list);
	str_index += 1 + strlen(dir_list);

	/* Sanity check */
	if (str_index != strtab_sz) {
		errx(1, "str_index(%d) != strtab_sz(%d)", str_index, strtab_sz);
	}

	tmpfilename = concat(hints_file, ".XXXXXXXXXX", "");
	umask(0);	/* Create with exact permissions */
	if ((fd = mkstemp(tmpfilename)) == -1) {
		warn("%s", tmpfilename);
		return -1;
	}
	fchmod(fd, 0444);

	if (write(fd, &hdr, sizeof(struct hints_header)) !=
						sizeof(struct hints_header)) {
		warn("%s", hints_file);
		return -1;
	}
	if (write(fd, blist, hdr.hh_nbucket * sizeof(*blist)) !=
				(ssize_t)(hdr.hh_nbucket * sizeof(*blist))) {
		warn("%s", hints_file);
		return -1;
	}
	if (write(fd, strtab, strtab_sz) != strtab_sz) {
		warn("%s", hints_file);
		return -1;
	}
	if (close(fd) != 0) {
		warn("%s", hints_file);
		return -1;
	}
	if (rename(tmpfilename, hints_file) != 0) {
		warn("%s", hints_file);
		return -1;
	}

	return 0;
}

static int
readhints(void)
{
	int			fd;
	void			*addr;
	long			fsize;
	long			msize;
	struct hints_header	*hdr;
	struct hints_bucket	*blist;
	char			*strtab;
	struct shlib_list	*shp;
	int			i;

	if ((fd = open(hints_file, O_RDONLY, 0)) == -1) {
		warn("%s", hints_file);
		return -1;
	}

	msize = PAGE_SIZE;
	addr = mmap(0, msize, PROT_READ, MAP_PRIVATE, fd, 0);

	if (addr == MAP_FAILED) {
		warn("%s", hints_file);
		return -1;
	}

	hdr = (struct hints_header *)addr;
	if (HH_BADMAG(*hdr)) {
		warnx("%s: bad magic: %lo", hints_file,
			(unsigned long)hdr->hh_magic);
		return -1;
	}

	if (hdr->hh_version != LD_HINTS_VERSION_1 &&
	    hdr->hh_version != LD_HINTS_VERSION_2) {
		warnx("unsupported version: %ld", (long)hdr->hh_version);
		return -1;
	}

	if (hdr->hh_ehints > msize) {
		fsize = hdr->hh_ehints;
		munmap(addr, msize);
		addr = mmap(0, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
		if (addr == MAP_FAILED) {
			warn("%s", hints_file);
			return -1;
		}
		hdr = (struct hints_header *)addr;
	}
	close(fd);

	strtab = (char *)addr + hdr->hh_strtab;

	if (hdr->hh_version >= LD_HINTS_VERSION_2)
		add_search_path(strtab + hdr->hh_dirlist);
	else if (rescan)
		errx(1, "%s too old and does not contain the search path",
			hints_file);

	if (rescan)
		return 0;

	blist = malloc(sizeof(*blist) * hdr->hh_nbucket);
	if (blist == NULL)
		err(1, "readhints");
	memcpy(blist, (char *)addr + hdr->hh_hashtab,
		sizeof(*blist) * hdr->hh_nbucket);


	for (i = 0; i < hdr->hh_nbucket; i++) {
		struct hints_bucket	*bp = &blist[i];

		/* Sanity check */
		if (bp->hi_namex >= hdr->hh_strtab_sz) {
			warnx("bad name index: %#x", bp->hi_namex);
			free(blist);
			return -1;
		}
		if (bp->hi_pathx >= hdr->hh_strtab_sz) {
			warnx("bad path index: %#x", bp->hi_pathx);
			free(blist);
			return -1;
		}

		/* Allocate new list element */
		shp = (struct shlib_list *)xmalloc(sizeof *shp);
		shp->name = strdup(strtab + bp->hi_namex);
		shp->path = strdup(strtab + bp->hi_pathx);
		bcopy(bp->hi_dewey, shp->dewey, sizeof(shp->dewey));
		shp->ndewey = bp->hi_ndewey;
		shp->next = NULL;

		*shlib_tail = shp;
		shlib_tail = &shp->next;
	}

	free(blist);
	return 0;
}

static void
listhints(void)
{
	struct shlib_list	*shp;
	int			i;

	printf("%s:\n", hints_file);
	printf("\tsearch directories: %s\n", dir_list);

	for (i = 0, shp = shlib_head; shp; i++, shp = shp->next)
		printf("\t%d:-l%s.%d.%d => %s\n",
			i, shp->name, shp->major, shp->minor, shp->path);

	return;
}