Line data Source code
1 : /* Print the strings of printable characters in files.
2 : Copyright (C) 2005-2010, 2012, 2014 Red Hat, Inc.
3 : This file is part of elfutils.
4 : Written by Ulrich Drepper <drepper@redhat.com>, 2005.
5 :
6 : This file is free software; you can redistribute it and/or modify
7 : it under the terms of the GNU General Public License as published by
8 : the Free Software Foundation; either version 3 of the License, or
9 : (at your option) any later version.
10 :
11 : elfutils is distributed in the hope that it will be useful, but
12 : WITHOUT ANY WARRANTY; without even the implied warranty of
13 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : GNU General Public License for more details.
15 :
16 : You should have received a copy of the GNU General Public License
17 : along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 :
19 : #ifdef HAVE_CONFIG_H
20 : # include <config.h>
21 : #endif
22 :
23 : #include <argp.h>
24 : #include <assert.h>
25 : #include <ctype.h>
26 : #include <endian.h>
27 : #include <errno.h>
28 : #include <error.h>
29 : #include <fcntl.h>
30 : #include <gelf.h>
31 : #include <inttypes.h>
32 : #include <libintl.h>
33 : #include <locale.h>
34 : #include <stdbool.h>
35 : #include <stdio.h>
36 : #include <stdio_ext.h>
37 : #include <stdlib.h>
38 : #include <string.h>
39 : #include <unistd.h>
40 : #include <sys/mman.h>
41 : #include <sys/stat.h>
42 :
43 : #include <libeu.h>
44 : #include <system.h>
45 : #include <printversion.h>
46 :
47 : #ifndef MAP_POPULATE
48 : # define MAP_POPULATE 0
49 : #endif
50 :
51 :
52 : /* Prototypes of local functions. */
53 : static int read_fd (int fd, const char *fname, off_t fdlen);
54 : static int read_elf (Elf *elf, int fd, const char *fname, off_t fdlen);
55 :
56 :
57 : /* Name and version of program. */
58 : ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
59 :
60 : /* Bug report address. */
61 : ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
62 :
63 : /* Definitions of arguments for argp functions. */
64 : static const struct argp_option options[] =
65 : {
66 : { NULL, 0, NULL, 0, N_("Output Selection:"), 0 },
67 : { "all", 'a', NULL, 0, N_("Scan entire file, not only loaded sections"), 0 },
68 : { "bytes", 'n', "MIN-LEN", 0,
69 : N_("Only NUL-terminated sequences of MIN-LEN characters or more are printed"), 0 },
70 : { "encoding", 'e', "SELECTOR", 0, N_("\
71 : Select character size and endianess: s = 7-bit, S = 8-bit, {b,l} = 16-bit, {B,L} = 32-bit"),
72 : 0},
73 : { "print-file-name", 'f', NULL, 0,
74 : N_("Print name of the file before each string."), 0 },
75 : { "radix", 't', "{o,d,x}", 0,
76 : N_("Print location of the string in base 8, 10, or 16 respectively."), 0 },
77 : { NULL, 'o', NULL, 0, N_("Alias for --radix=o"), 0 },
78 :
79 : { NULL, 0, NULL, 0, N_("Miscellaneous:"), 0 },
80 : { NULL, 0, NULL, 0, NULL, 0 }
81 : };
82 :
83 : /* Short description of program. */
84 : static const char doc[] = N_("\
85 : Print the strings of printable characters in files.");
86 :
87 : /* Strings for arguments in help texts. */
88 : static const char args_doc[] = N_("[FILE...]");
89 :
90 : /* Prototype for option handler. */
91 : static error_t parse_opt (int key, char *arg, struct argp_state *state);
92 :
93 : /* Data structure to communicate with argp functions. */
94 : static struct argp argp =
95 : {
96 : options, parse_opt, args_doc, doc, NULL, NULL, NULL
97 : };
98 :
99 :
100 : /* Global variables. */
101 :
102 : /* True if whole file and not only loaded sections are looked at. */
103 : static bool entire_file;
104 :
105 : /* Minimum length of any sequence reported. */
106 : static size_t min_len = 4;
107 :
108 : /* Number of bytes per character. */
109 : static size_t bytes_per_char = 1;
110 :
111 : /* Minimum length of any sequence reported in bytes. */
112 : static size_t min_len_bytes;
113 :
114 : /* True if multibyte characters are in big-endian order. */
115 : static bool big_endian;
116 :
117 : /* True unless 7-bit ASCII are expected. */
118 : static bool char_7bit;
119 :
120 : /* True if file names should be printed before strings. */
121 : static bool print_file_name;
122 :
123 : /* Radix for printed numbers. */
124 : static enum
125 : {
126 : radix_none = 0,
127 : radix_decimal,
128 : radix_hex,
129 : radix_octal
130 : } radix = radix_none;
131 :
132 :
133 : /* Page size in use. */
134 : static size_t ps;
135 :
136 :
137 : /* Mapped parts of the ELF file. */
138 : static unsigned char *elfmap;
139 : static unsigned char *elfmap_base;
140 : static size_t elfmap_size;
141 : static off_t elfmap_off;
142 :
143 :
144 : int
145 1 : main (int argc, char *argv[])
146 : {
147 : /* We use no threads. */
148 1 : __fsetlocking (stdin, FSETLOCKING_BYCALLER);
149 1 : __fsetlocking (stdout, FSETLOCKING_BYCALLER);
150 :
151 : /* Set locale. */
152 1 : (void) setlocale (LC_ALL, "");
153 :
154 : /* Make sure the message catalog can be found. */
155 1 : (void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
156 :
157 : /* Initialize the message catalog. */
158 1 : (void) textdomain (PACKAGE_TARNAME);
159 :
160 : /* Parse and process arguments. */
161 : int remaining;
162 1 : (void) argp_parse (&argp, argc, argv, 0, &remaining, NULL);
163 :
164 : /* Tell the library which version we are expecting. */
165 1 : elf_version (EV_CURRENT);
166 :
167 : /* Determine the page size. We will likely need it a couple of times. */
168 1 : ps = sysconf (_SC_PAGESIZE);
169 :
170 : struct stat st;
171 1 : int result = 0;
172 1 : if (remaining == argc)
173 : /* We read from standard input. This we cannot do for a
174 : structured file. */
175 0 : result = read_fd (STDIN_FILENO,
176 : print_file_name ? "{standard input}" : NULL,
177 0 : (fstat (STDIN_FILENO, &st) == 0 && S_ISREG (st.st_mode))
178 : ? st.st_size : INT64_C (0x7fffffffffffffff));
179 : else
180 : do
181 : {
182 18 : int fd = (strcmp (argv[remaining], "-") == 0
183 9 : ? STDIN_FILENO : open (argv[remaining], O_RDONLY));
184 9 : if (unlikely (fd == -1))
185 : {
186 0 : error (0, errno, gettext ("cannot open '%s'"), argv[remaining]);
187 0 : result = 1;
188 : }
189 : else
190 : {
191 9 : const char *fname = print_file_name ? argv[remaining] : NULL;
192 9 : int fstat_fail = fstat (fd, &st);
193 9 : off_t fdlen = (fstat_fail
194 9 : ? INT64_C (0x7fffffffffffffff) : st.st_size);
195 9 : if (fdlen > (off_t) min_len_bytes)
196 : {
197 9 : Elf *elf = NULL;
198 9 : if (entire_file
199 9 : || fstat_fail
200 9 : || !S_ISREG (st.st_mode)
201 9 : || (elf = elf_begin (fd, ELF_C_READ, NULL)) == NULL
202 9 : || elf_kind (elf) != ELF_K_ELF)
203 0 : result |= read_fd (fd, fname, fdlen);
204 : else
205 9 : result |= read_elf (elf, fd, fname, fdlen);
206 :
207 : /* This call will succeed even if ELF is NULL. */
208 9 : elf_end (elf);
209 : }
210 :
211 9 : if (strcmp (argv[remaining], "-") != 0)
212 9 : close (fd);
213 : }
214 :
215 9 : if (elfmap != NULL && elfmap != MAP_FAILED)
216 0 : munmap (elfmap, elfmap_size);
217 9 : elfmap = NULL;
218 : }
219 9 : while (++remaining < argc);
220 :
221 : return result;
222 : }
223 :
224 :
225 : /* Handle program arguments. */
226 : static error_t
227 7 : parse_opt (int key, char *arg,
228 : struct argp_state *state __attribute__ ((unused)))
229 : {
230 7 : switch (key)
231 : {
232 : case 'a':
233 0 : entire_file = true;
234 0 : break;
235 :
236 : case 'e':
237 : /* We expect a string of one character. */
238 0 : switch (arg[1] != '\0' ? '\0' : arg[0])
239 : {
240 : case 's':
241 : case 'S':
242 0 : char_7bit = arg[0] == 's';
243 0 : bytes_per_char = 1;
244 0 : break;
245 :
246 : case 'b':
247 : case 'B':
248 0 : big_endian = true;
249 : FALLTHROUGH;
250 :
251 : case 'l':
252 : case 'L':
253 0 : bytes_per_char = isupper (arg[0]) ? 4 : 2;
254 0 : break;
255 :
256 : default:
257 0 : error (0, 0, gettext ("invalid value '%s' for %s parameter"),
258 : arg, "-e");
259 0 : argp_help (&argp, stderr, ARGP_HELP_SEE, "strings");
260 0 : return ARGP_ERR_UNKNOWN;
261 : }
262 : break;
263 :
264 : case 'f':
265 1 : print_file_name = true;
266 1 : break;
267 :
268 : case 'n':
269 0 : min_len = atoi (arg);
270 0 : break;
271 :
272 : case 'o':
273 : goto octfmt;
274 :
275 : case 't':
276 1 : switch (arg[0])
277 : {
278 : case 'd':
279 0 : radix = radix_decimal;
280 0 : break;
281 :
282 : case 'o':
283 : octfmt:
284 0 : radix = radix_octal;
285 0 : break;
286 :
287 : case 'x':
288 1 : radix = radix_hex;
289 1 : break;
290 :
291 : default:
292 0 : error (0, 0, gettext ("invalid value '%s' for %s parameter"),
293 : arg, "-t");
294 0 : argp_help (&argp, stderr, ARGP_HELP_SEE, "strings");
295 0 : return ARGP_ERR_UNKNOWN;
296 : }
297 : break;
298 :
299 : case ARGP_KEY_FINI:
300 : /* Compute the length in bytes of any match. */
301 1 : if (min_len <= 0 || min_len > INT_MAX / bytes_per_char)
302 : error (EXIT_FAILURE, 0,
303 0 : gettext ("invalid minimum length of matched string size"));
304 1 : min_len_bytes = min_len * bytes_per_char;
305 1 : break;
306 :
307 : default:
308 : return ARGP_ERR_UNKNOWN;
309 : }
310 : return 0;
311 : }
312 :
313 :
314 : static void
315 0 : process_chunk_mb (const char *fname, const unsigned char *buf, off_t to,
316 : size_t len, char **unprinted)
317 : {
318 0 : size_t curlen = *unprinted == NULL ? 0 : strlen (*unprinted);
319 0 : const unsigned char *start = buf;
320 0 : while (len >= bytes_per_char)
321 : {
322 : uint32_t ch;
323 :
324 0 : if (bytes_per_char == 2)
325 : {
326 0 : if (big_endian)
327 0 : ch = buf[0] << 8 | buf[1];
328 : else
329 0 : ch = buf[1] << 8 | buf[0];
330 : }
331 : else
332 : {
333 0 : if (big_endian)
334 0 : ch = buf[0] << 24 | buf[1] << 16 | buf[2] << 8 | buf[3];
335 : else
336 0 : ch = buf[3] << 24 | buf[2] << 16 | buf[1] << 8 | buf[0];
337 : }
338 :
339 0 : if (ch <= 255 && (isprint (ch) || ch == '\t'))
340 : {
341 0 : ++buf;
342 0 : ++curlen;
343 : }
344 : else
345 : {
346 0 : if (curlen >= min_len)
347 : {
348 : /* We found a match. */
349 0 : if (unlikely (fname != NULL))
350 : {
351 0 : fputs_unlocked (fname, stdout);
352 0 : fputs_unlocked (": ", stdout);
353 : }
354 :
355 0 : if (unlikely (radix != radix_none))
356 0 : printf ((radix == radix_octal ? "%7" PRIo64 " "
357 : : (radix == radix_decimal ? "%7" PRId64 " "
358 : : "%7" PRIx64 " ")),
359 0 : (int64_t) to - len - (buf - start));
360 :
361 0 : if (unlikely (*unprinted != NULL))
362 : {
363 0 : fputs_unlocked (*unprinted, stdout);
364 0 : free (*unprinted);
365 0 : *unprinted = NULL;
366 : }
367 :
368 : /* There is no sane way of printing the string. If we
369 : assume the file data is encoded in UCS-2/UTF-16 or
370 : UCS-4/UTF-32 respectively we could covert the string.
371 : But there is no such guarantee. */
372 0 : fwrite_unlocked (start, 1, buf - start, stdout);
373 0 : putc_unlocked ('\n', stdout);
374 : }
375 :
376 0 : start = ++buf;
377 0 : curlen = 0;
378 :
379 0 : if (len <= min_len)
380 : break;
381 : }
382 :
383 0 : --len;
384 : }
385 :
386 0 : if (curlen != 0)
387 0 : *unprinted = xstrndup ((const char *) start, curlen);
388 0 : }
389 :
390 :
391 : static void
392 158 : process_chunk (const char *fname, const unsigned char *buf, off_t to,
393 : size_t len, char **unprinted)
394 : {
395 : /* We are not going to slow the check down for the 2- and 4-byte
396 : encodings. Handle them special. */
397 158 : if (unlikely (bytes_per_char != 1))
398 : {
399 0 : process_chunk_mb (fname, buf, to, len, unprinted);
400 158 : return;
401 : }
402 :
403 158 : size_t curlen = *unprinted == NULL ? 0 : strlen (*unprinted);
404 158 : const unsigned char *start = buf;
405 68202 : while (len > 0)
406 : {
407 68042 : if ((isprint (*buf) || *buf == '\t') && (! char_7bit || *buf <= 127))
408 : {
409 18503 : ++buf;
410 18503 : ++curlen;
411 : }
412 : else
413 : {
414 49539 : if (curlen >= min_len)
415 : {
416 : /* We found a match. */
417 443 : if (likely (fname != NULL))
418 : {
419 443 : fputs_unlocked (fname, stdout);
420 443 : fputs_unlocked (": ", stdout);
421 : }
422 :
423 443 : if (likely (radix != radix_none))
424 443 : printf ((radix == radix_octal ? "%7" PRIo64 " "
425 : : (radix == radix_decimal ? "%7" PRId64 " "
426 : : "%7" PRIx64 " ")),
427 443 : (int64_t) to - len - (buf - start));
428 :
429 443 : if (unlikely (*unprinted != NULL))
430 : {
431 0 : fputs_unlocked (*unprinted, stdout);
432 0 : free (*unprinted);
433 0 : *unprinted = NULL;
434 : }
435 443 : fwrite_unlocked (start, 1, buf - start, stdout);
436 443 : putc_unlocked ('\n', stdout);
437 : }
438 :
439 49539 : start = ++buf;
440 49539 : curlen = 0;
441 :
442 49539 : if (len <= min_len)
443 : break;
444 : }
445 :
446 67886 : --len;
447 : }
448 :
449 158 : if (curlen != 0)
450 0 : *unprinted = xstrndup ((const char *) start, curlen);
451 : }
452 :
453 :
454 : /* Map a file in as large chunks as possible. */
455 : static void *
456 9 : map_file (int fd, off_t start_off, off_t fdlen, size_t *map_sizep)
457 : {
458 : /* Maximum size we mmap. We use an #ifdef to avoid overflows on
459 : 32-bit machines. 64-bit machines these days do not have usable
460 : address spaces larger than about 43 bits. Not that any file
461 : should be that large. */
462 : # if SIZE_MAX > 0xffffffff
463 9 : const size_t mmap_max = 0x4000000000lu;
464 : # else
465 : const size_t mmap_max = 0x40000000lu;
466 : # endif
467 :
468 : /* Try to mmap the file. */
469 9 : size_t map_size = MIN ((off_t) mmap_max, fdlen);
470 9 : const size_t map_size_min = MAX (MAX (SIZE_MAX / 16, 2 * ps),
471 : roundup (2 * min_len_bytes + 1, ps));
472 : void *mem;
473 : while (1)
474 : {
475 : /* We map the memory for reading only here. Since we will
476 : always look at every byte of the file it makes sense to
477 : use MAP_POPULATE. */
478 9 : mem = mmap (NULL, map_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
479 : fd, start_off);
480 9 : if (mem != MAP_FAILED)
481 : {
482 : /* We will go through the mapping sequentially. */
483 9 : (void) posix_madvise (mem, map_size, POSIX_MADV_SEQUENTIAL);
484 9 : break;
485 : }
486 0 : if (errno != EINVAL && errno != ENOMEM)
487 : /* This is an error other than the lack of address space. */
488 : break;
489 :
490 : /* Maybe the size of the mapping is too big. Try again. */
491 0 : map_size /= 2;
492 0 : if (map_size < map_size_min)
493 : /* That size should have fit. */
494 : break;
495 : }
496 :
497 9 : *map_sizep = map_size;
498 9 : return mem;
499 : }
500 :
501 :
502 : /* Read the file without mapping. */
503 : static int
504 0 : read_block_no_mmap (int fd, const char *fname, off_t from, off_t fdlen)
505 : {
506 0 : char *unprinted = NULL;
507 : #define CHUNKSIZE 65536
508 0 : unsigned char *buf = xmalloc (CHUNKSIZE + min_len_bytes
509 0 : + bytes_per_char - 1);
510 0 : size_t ntrailer = 0;
511 0 : int result = 0;
512 0 : while (fdlen > 0)
513 : {
514 0 : ssize_t n = TEMP_FAILURE_RETRY (read (fd, buf + ntrailer,
515 : MIN (fdlen, CHUNKSIZE)));
516 0 : if (n == 0)
517 : {
518 : /* There are less than MIN_LEN+1 bytes left so there cannot be
519 : another match. */
520 0 : assert (unprinted == NULL || ntrailer == 0);
521 : break;
522 : }
523 0 : if (unlikely (n < 0))
524 : {
525 : /* Something went wrong. */
526 : result = 1;
527 : break;
528 : }
529 :
530 : /* Account for the number of bytes read in this round. */
531 0 : fdlen -= n;
532 :
533 : /* Do not use the signed N value. Note that the addition cannot
534 : overflow. */
535 0 : size_t nb = (size_t) n + ntrailer;
536 0 : if (nb >= min_len_bytes)
537 : {
538 : /* We only use complete characters. */
539 0 : nb &= ~(bytes_per_char - 1);
540 :
541 0 : process_chunk (fname, buf, from + nb, nb, &unprinted);
542 :
543 : /* If the last bytes of the buffer (modulo the character
544 : size) have been printed we are not copying them. */
545 0 : size_t to_keep = unprinted != NULL ? 0 : min_len_bytes;
546 :
547 0 : memmove (buf, buf + nb - to_keep, to_keep);
548 0 : ntrailer = to_keep;
549 0 : from += nb;
550 : }
551 : else
552 : ntrailer = nb;
553 : }
554 :
555 0 : free (buf);
556 :
557 : /* Don't print anything we collected so far. There is no
558 : terminating NUL byte. */
559 0 : free (unprinted);
560 :
561 0 : return result;
562 : }
563 :
564 :
565 : static int
566 158 : read_block (int fd, const char *fname, off_t fdlen, off_t from, off_t to)
567 : {
568 158 : if (elfmap == NULL)
569 : {
570 : /* We need a completely new mapping. */
571 9 : elfmap_off = from & ~(ps - 1);
572 9 : elfmap_base = elfmap = map_file (fd, elfmap_off, fdlen, &elfmap_size);
573 :
574 9 : if (unlikely (elfmap == MAP_FAILED))
575 : /* Let the kernel know we are going to read everything in sequence. */
576 0 : (void) posix_fadvise (fd, 0, 0, POSIX_FADV_SEQUENTIAL);
577 : }
578 :
579 158 : if (unlikely (elfmap == MAP_FAILED))
580 : {
581 : /* Read from the file descriptor. For this we must position the
582 : read pointer. */
583 : // XXX Eventually add flag which avoids this if the position
584 : // XXX is known to match.
585 0 : if (from != 0 && lseek (fd, from, SEEK_SET) != from)
586 0 : error (EXIT_FAILURE, errno, gettext ("lseek failed"));
587 :
588 0 : return read_block_no_mmap (fd, fname, from, to - from);
589 : }
590 :
591 158 : assert ((off_t) min_len_bytes < fdlen);
592 :
593 158 : if (to < (off_t) elfmap_off || from > (off_t) (elfmap_off + elfmap_size))
594 : {
595 : /* The existing mapping cannot fit at all. Map the new area.
596 : We always map the full range of ELFMAP_SIZE bytes even if
597 : this extend beyond the end of the file. The Linux kernel
598 : handles this OK if the access pages are not touched. */
599 0 : elfmap_off = from & ~(ps - 1);
600 0 : if (mmap (elfmap, elfmap_size, PROT_READ,
601 : MAP_PRIVATE | MAP_POPULATE | MAP_FIXED, fd, from)
602 : == MAP_FAILED)
603 0 : error (EXIT_FAILURE, errno, gettext ("re-mmap failed"));
604 0 : elfmap_base = elfmap;
605 : }
606 :
607 158 : char *unprinted = NULL;
608 :
609 : /* Use the existing mapping as much as possible. If necessary, map
610 : new pages. */
611 158 : if (from >= (off_t) elfmap_off
612 158 : && from < (off_t) (elfmap_off + elfmap_size))
613 : /* There are at least a few bytes in this mapping which we can
614 : use. */
615 158 : process_chunk (fname, elfmap_base + (from - elfmap_off),
616 : MIN (to, (off_t) (elfmap_off + elfmap_size)),
617 158 : MIN (to, (off_t) (elfmap_off + elfmap_size)) - from,
618 : &unprinted);
619 :
620 158 : if (to > (off_t) (elfmap_off + elfmap_size))
621 : {
622 0 : unsigned char *remap_base = elfmap_base;
623 0 : size_t read_now = elfmap_size - (elfmap_base - elfmap);
624 :
625 0 : assert (from >= (off_t) elfmap_off
626 : && from < (off_t) (elfmap_off + elfmap_size));
627 0 : off_t handled_to = elfmap_off + elfmap_size;
628 0 : assert (elfmap == elfmap_base
629 : || (elfmap_base - elfmap
630 : == (ptrdiff_t) ((min_len_bytes + ps - 1) & ~(ps - 1))));
631 0 : if (elfmap == elfmap_base)
632 : {
633 0 : size_t keep_area = (min_len_bytes + ps - 1) & ~(ps - 1);
634 0 : assert (elfmap_size >= keep_area + ps);
635 : /* The keep area is used for the content of the previous
636 : buffer we have to keep. This means copying those bytes
637 : and for this we have to make the data writable. */
638 0 : if (unlikely (mprotect (elfmap, keep_area, PROT_READ | PROT_WRITE)
639 : != 0))
640 0 : error (EXIT_FAILURE, errno, gettext ("mprotect failed"));
641 :
642 0 : elfmap_base = elfmap + keep_area;
643 : }
644 :
645 : while (1)
646 : {
647 : /* Map the rest of the file, eventually again in pieces.
648 : We speed things up with a nice Linux feature. Note
649 : that we have at least two pages mapped. */
650 0 : size_t to_keep = unprinted != NULL ? 0 : min_len_bytes;
651 :
652 0 : assert (read_now >= to_keep);
653 0 : memmove (elfmap_base - to_keep,
654 0 : remap_base + read_now - to_keep, to_keep);
655 0 : remap_base = elfmap_base;
656 :
657 0 : assert ((elfmap_size - (elfmap_base - elfmap)) % bytes_per_char
658 : == 0);
659 0 : read_now = MIN (to - handled_to,
660 : (ptrdiff_t) elfmap_size - (elfmap_base - elfmap));
661 :
662 0 : assert (handled_to % ps == 0);
663 0 : assert (handled_to % bytes_per_char == 0);
664 0 : if (mmap (remap_base, read_now, PROT_READ,
665 : MAP_PRIVATE | MAP_POPULATE | MAP_FIXED, fd, handled_to)
666 : == MAP_FAILED)
667 0 : error (EXIT_FAILURE, errno, gettext ("re-mmap failed"));
668 0 : elfmap_off = handled_to;
669 :
670 0 : process_chunk (fname, remap_base - to_keep,
671 0 : elfmap_off + (read_now & ~(bytes_per_char - 1)),
672 0 : to_keep + (read_now & ~(bytes_per_char - 1)),
673 : &unprinted);
674 0 : handled_to += read_now;
675 0 : if (handled_to >= to)
676 : break;
677 : }
678 : }
679 :
680 : /* Don't print anything we collected so far. There is no
681 : terminating NUL byte. */
682 158 : free (unprinted);
683 :
684 158 : return 0;
685 : }
686 :
687 :
688 : static int
689 : read_fd (int fd, const char *fname, off_t fdlen)
690 : {
691 0 : return read_block (fd, fname, fdlen, 0, fdlen);
692 : }
693 :
694 :
695 : static int
696 9 : read_elf (Elf *elf, int fd, const char *fname, off_t fdlen)
697 : {
698 9 : assert (fdlen >= 0);
699 :
700 : /* We will look at each section separately. The ELF file is not
701 : mmapped. The libelf implementation will load the needed parts on
702 : demand. Since we only interate over the section header table the
703 : memory consumption at this stage is kept minimal. */
704 9 : Elf_Scn *scn = elf_nextscn (elf, NULL);
705 9 : if (scn == NULL)
706 0 : return read_fd (fd, fname, fdlen);
707 :
708 : int result = 0;
709 : do
710 : {
711 : GElf_Shdr shdr_mem;
712 276 : GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
713 :
714 : /* Only look in sections which are loaded at runtime and
715 : actually have content. */
716 276 : if (shdr != NULL && shdr->sh_type != SHT_NOBITS
717 265 : && (shdr->sh_flags & SHF_ALLOC) != 0)
718 : {
719 158 : if (shdr->sh_offset > (Elf64_Off) fdlen
720 158 : || fdlen - shdr->sh_offset < shdr->sh_size)
721 0 : {
722 0 : size_t strndx = 0;
723 : const char *sname;
724 0 : if (unlikely (elf_getshdrstrndx (elf, &strndx) < 0))
725 : sname = "<unknown>";
726 : else
727 0 : sname = elf_strptr (elf, strndx, shdr->sh_name) ?: "<unknown>";
728 0 : error (0, 0,
729 0 : gettext ("Skipping section %zd '%s' data outside file"),
730 : elf_ndxscn (scn), sname);
731 0 : result = 1;
732 : }
733 : else
734 158 : result |= read_block (fd, fname, fdlen, shdr->sh_offset,
735 158 : shdr->sh_offset + shdr->sh_size);
736 : }
737 : }
738 276 : while ((scn = elf_nextscn (elf, scn)) != NULL);
739 :
740 9 : if (elfmap != NULL && elfmap != MAP_FAILED)
741 9 : munmap (elfmap, elfmap_size);
742 9 : elfmap = NULL;
743 :
744 9 : return result;
745 : }
746 :
747 :
748 : #include "debugpred.h"
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