Line data Source code
1 : /* Discard section not used at runtime from object files.
2 : Copyright (C) 2000-2012, 2014, 2015, 2016, 2017 Red Hat, Inc.
3 : This file is part of elfutils.
4 : Written by Ulrich Drepper <drepper@redhat.com>, 2000.
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 <byteswap.h>
26 : #include <endian.h>
27 : #include <fcntl.h>
28 : #include <fnmatch.h>
29 : #include <gelf.h>
30 : #include <libelf.h>
31 : #include <libintl.h>
32 : #include <locale.h>
33 : #include <stdbool.h>
34 : #include <stdio.h>
35 : #include <stdio_ext.h>
36 : #include <stdlib.h>
37 : #include <string.h>
38 : #include <unistd.h>
39 : #include <sys/stat.h>
40 : #include <sys/time.h>
41 :
42 : #include <elf-knowledge.h>
43 : #include <libebl.h>
44 : #include "libdwelf.h"
45 : #include <libeu.h>
46 : #include <system.h>
47 : #include <printversion.h>
48 :
49 : typedef uint8_t GElf_Byte;
50 :
51 : /* Name and version of program. */
52 : ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
53 :
54 : /* Bug report address. */
55 : ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
56 :
57 :
58 : /* Values for the parameters which have no short form. */
59 : #define OPT_REMOVE_COMMENT 0x100
60 : #define OPT_PERMISSIVE 0x101
61 : #define OPT_STRIP_SECTIONS 0x102
62 : #define OPT_RELOC_DEBUG 0x103
63 : #define OPT_KEEP_SECTION 0x104
64 :
65 :
66 : /* Definitions of arguments for argp functions. */
67 : static const struct argp_option options[] =
68 : {
69 : { NULL, 0, NULL, 0, N_("Output selection:"), 0 },
70 : { "output", 'o', "FILE", 0, N_("Place stripped output into FILE"), 0 },
71 : { NULL, 'f', "FILE", 0, N_("Extract the removed sections into FILE"), 0 },
72 : { NULL, 'F', "FILE", 0, N_("Embed name FILE instead of -f argument"), 0 },
73 :
74 : { NULL, 0, NULL, 0, N_("Output options:"), 0 },
75 : { "strip-all", 's', NULL, OPTION_HIDDEN, NULL, 0 },
76 : { "strip-debug", 'g', NULL, 0, N_("Remove all debugging symbols"), 0 },
77 : { NULL, 'd', NULL, OPTION_ALIAS, NULL, 0 },
78 : { NULL, 'S', NULL, OPTION_ALIAS, NULL, 0 },
79 : { "strip-sections", OPT_STRIP_SECTIONS, NULL, 0,
80 : N_("Remove section headers (not recommended)"), 0 },
81 : { "preserve-dates", 'p', NULL, 0,
82 : N_("Copy modified/access timestamps to the output"), 0 },
83 : { "reloc-debug-sections", OPT_RELOC_DEBUG, NULL, 0,
84 : N_("Resolve all trivial relocations between debug sections if the removed sections are placed in a debug file (only relevant for ET_REL files, operation is not reversable, needs -f)"), 0 },
85 : { "remove-comment", OPT_REMOVE_COMMENT, NULL, 0,
86 : N_("Remove .comment section"), 0 },
87 : { "remove-section", 'R', "SECTION", 0, N_("Remove the named section. SECTION is an extended wildcard pattern. May be given more than once. Only non-allocated sections can be removed."), 0 },
88 : { "keep-section", OPT_KEEP_SECTION, "SECTION", 0, N_("Keep the named section. SECTION is an extended wildcard pattern. May be given more than once."), 0 },
89 : { "permissive", OPT_PERMISSIVE, NULL, 0,
90 : N_("Relax a few rules to handle slightly broken ELF files"), 0 },
91 : { NULL, 0, NULL, 0, NULL, 0 }
92 : };
93 :
94 : /* Short description of program. */
95 : static const char doc[] = N_("Discard symbols from object files.");
96 :
97 : /* Strings for arguments in help texts. */
98 : static const char args_doc[] = N_("[FILE...]");
99 :
100 : /* Prototype for option handler. */
101 : static error_t parse_opt (int key, char *arg, struct argp_state *state);
102 :
103 : /* Data structure to communicate with argp functions. */
104 : static struct argp argp =
105 : {
106 : options, parse_opt, args_doc, doc, NULL, NULL, NULL
107 : };
108 :
109 :
110 : /* Print symbols in file named FNAME. */
111 : static int process_file (const char *fname);
112 :
113 : /* Handle one ELF file. */
114 : static int handle_elf (int fd, Elf *elf, const char *prefix,
115 : const char *fname, mode_t mode, struct timespec tvp[2]);
116 :
117 : /* Handle all files contained in the archive. */
118 : static int handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
119 : struct timespec tvp[2]) __attribute__ ((unused));
120 :
121 : static int debug_fd = -1;
122 : static char *tmp_debug_fname = NULL;
123 :
124 : /* Close debug file descriptor, if opened. And remove temporary debug file. */
125 : static void cleanup_debug (void);
126 :
127 : #define INTERNAL_ERROR(fname) \
128 : do { \
129 : cleanup_debug (); \
130 : error (EXIT_FAILURE, 0, gettext ("%s: INTERNAL ERROR %d (%s): %s"), \
131 : fname, __LINE__, PACKAGE_VERSION, elf_errmsg (-1)); \
132 : } while (0)
133 :
134 :
135 : /* Name of the output file. */
136 : static const char *output_fname;
137 :
138 : /* Name of the debug output file. */
139 : static const char *debug_fname;
140 :
141 : /* Name to pretend the debug output file has. */
142 : static const char *debug_fname_embed;
143 :
144 : /* If true output files shall have same date as the input file. */
145 : static bool preserve_dates;
146 :
147 : /* If true .comment sections will be removed. */
148 : static bool remove_comment;
149 :
150 : /* If true remove all debug sections. */
151 : static bool remove_debug;
152 :
153 : /* If true remove all section headers. */
154 : static bool remove_shdrs;
155 :
156 : /* If true relax some ELF rules for input files. */
157 : static bool permissive;
158 :
159 : /* If true perform relocations between debug sections. */
160 : static bool reloc_debug;
161 :
162 : /* Sections the user explicitly wants to keep or remove. */
163 : struct section_pattern
164 : {
165 : char *pattern;
166 : struct section_pattern *next;
167 : };
168 :
169 : static struct section_pattern *keep_secs = NULL;
170 : static struct section_pattern *remove_secs = NULL;
171 :
172 : static void
173 10 : add_pattern (struct section_pattern **patterns, const char *pattern)
174 : {
175 10 : struct section_pattern *p = xmalloc (sizeof *p);
176 10 : p->pattern = xstrdup (pattern);
177 10 : p->next = *patterns;
178 10 : *patterns = p;
179 10 : }
180 :
181 : static void
182 170 : free_sec_patterns (struct section_pattern *patterns)
183 : {
184 170 : struct section_pattern *pattern = patterns;
185 350 : while (pattern != NULL)
186 : {
187 10 : struct section_pattern *p = pattern;
188 10 : pattern = p->next;
189 10 : free (p->pattern);
190 10 : free (p);
191 : }
192 170 : }
193 :
194 : static void
195 85 : free_patterns (void)
196 : {
197 85 : free_sec_patterns (keep_secs);
198 85 : free_sec_patterns (remove_secs);
199 85 : }
200 :
201 : static bool
202 : section_name_matches (struct section_pattern *patterns, const char *name)
203 : {
204 398731 : struct section_pattern *pattern = patterns;
205 398982 : while (pattern != NULL)
206 : {
207 269 : if (fnmatch (pattern->pattern, name, FNM_EXTMATCH) == 0)
208 : return true;
209 251 : pattern = pattern->next;
210 : }
211 : return false;
212 : }
213 :
214 :
215 : int
216 85 : main (int argc, char *argv[])
217 : {
218 : int remaining;
219 85 : int result = 0;
220 :
221 : /* We use no threads here which can interfere with handling a stream. */
222 85 : __fsetlocking (stdin, FSETLOCKING_BYCALLER);
223 85 : __fsetlocking (stdout, FSETLOCKING_BYCALLER);
224 85 : __fsetlocking (stderr, FSETLOCKING_BYCALLER);
225 :
226 : /* Set locale. */
227 85 : setlocale (LC_ALL, "");
228 :
229 : /* Make sure the message catalog can be found. */
230 85 : bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
231 :
232 : /* Initialize the message catalog. */
233 85 : textdomain (PACKAGE_TARNAME);
234 :
235 : /* Parse and process arguments. */
236 85 : if (argp_parse (&argp, argc, argv, 0, &remaining, NULL) != 0)
237 : return EXIT_FAILURE;
238 :
239 85 : if (reloc_debug && debug_fname == NULL)
240 : error (EXIT_FAILURE, 0,
241 0 : gettext ("--reloc-debug-sections used without -f"));
242 :
243 : /* Tell the library which version we are expecting. */
244 85 : elf_version (EV_CURRENT);
245 :
246 85 : if (remaining == argc)
247 : /* The user didn't specify a name so we use a.out. */
248 5 : result = process_file ("a.out");
249 : else
250 : {
251 : /* If we have seen the '-o' or '-f' option there must be exactly one
252 : input file. */
253 80 : if ((output_fname != NULL || debug_fname != NULL)
254 66 : && remaining + 1 < argc)
255 0 : error (EXIT_FAILURE, 0, gettext ("\
256 : Only one input file allowed together with '-o' and '-f'"));
257 :
258 : /* Process all the remaining files. */
259 : do
260 80 : result |= process_file (argv[remaining]);
261 80 : while (++remaining < argc);
262 : }
263 :
264 85 : free_patterns ();
265 85 : return result;
266 : }
267 :
268 :
269 : /* Handle program arguments. */
270 : static error_t
271 596 : parse_opt (int key, char *arg, struct argp_state *state)
272 : {
273 596 : switch (key)
274 : {
275 49 : case 'f':
276 49 : if (debug_fname != NULL)
277 : {
278 0 : error (0, 0, gettext ("-f option specified twice"));
279 0 : return EINVAL;
280 : }
281 49 : debug_fname = arg;
282 49 : break;
283 :
284 6 : case 'F':
285 6 : if (debug_fname_embed != NULL)
286 : {
287 0 : error (0, 0, gettext ("-F option specified twice"));
288 0 : return EINVAL;
289 : }
290 6 : debug_fname_embed = arg;
291 6 : break;
292 :
293 69 : case 'o':
294 69 : if (output_fname != NULL)
295 : {
296 0 : error (0, 0, gettext ("-o option specified twice"));
297 0 : return EINVAL;
298 : }
299 69 : output_fname = arg;
300 69 : break;
301 :
302 0 : case 'p':
303 0 : preserve_dates = true;
304 0 : break;
305 :
306 11 : case OPT_RELOC_DEBUG:
307 11 : reloc_debug = true;
308 11 : break;
309 :
310 1 : case OPT_REMOVE_COMMENT:
311 1 : remove_comment = true;
312 1 : break;
313 :
314 4 : case 'R':
315 4 : if (fnmatch (arg, ".comment", FNM_EXTMATCH) == 0)
316 0 : remove_comment = true;
317 4 : add_pattern (&remove_secs, arg);
318 4 : break;
319 :
320 6 : case OPT_KEEP_SECTION:
321 6 : add_pattern (&keep_secs, arg);
322 6 : break;
323 :
324 25 : case 'g':
325 : case 'd':
326 : case 'S':
327 25 : remove_debug = true;
328 25 : break;
329 :
330 0 : case OPT_STRIP_SECTIONS:
331 0 : remove_shdrs = true;
332 0 : break;
333 :
334 0 : case OPT_PERMISSIVE:
335 0 : permissive = true;
336 0 : break;
337 :
338 : case 's': /* Ignored for compatibility. */
339 : break;
340 :
341 85 : case ARGP_KEY_SUCCESS:
342 85 : if (remove_comment == true
343 2 : && section_name_matches (keep_secs, ".comment"))
344 : {
345 0 : argp_error (state,
346 0 : gettext ("cannot both keep and remove .comment section"));
347 0 : return EINVAL;
348 : }
349 : break;
350 :
351 : default:
352 : return ARGP_ERR_UNKNOWN;
353 : }
354 : return 0;
355 : }
356 :
357 :
358 : static int
359 85 : process_file (const char *fname)
360 : {
361 : /* If we have to preserve the modify and access timestamps get them
362 : now. We cannot use fstat() after opening the file since the open
363 : would change the access time. */
364 : struct stat pre_st;
365 : struct timespec tv[2];
366 85 : again:
367 85 : if (preserve_dates)
368 : {
369 0 : if (stat (fname, &pre_st) != 0)
370 : {
371 0 : error (0, errno, gettext ("cannot stat input file '%s'"), fname);
372 0 : return 1;
373 : }
374 :
375 : /* If we have to preserve the timestamp, we need it in the
376 : format utimes() understands. */
377 0 : tv[0] = pre_st.st_atim;
378 0 : tv[1] = pre_st.st_mtim;
379 : }
380 :
381 : /* Open the file. */
382 170 : int fd = open (fname, output_fname == NULL ? O_RDWR : O_RDONLY);
383 85 : if (fd == -1)
384 : {
385 0 : error (0, errno, gettext ("while opening '%s'"), fname);
386 0 : return 1;
387 : }
388 :
389 : /* We always use fstat() even if we called stat() before. This is
390 : done to make sure the information returned by stat() is for the
391 : same file. */
392 : struct stat st;
393 85 : if (fstat (fd, &st) != 0)
394 : {
395 0 : error (0, errno, gettext ("cannot stat input file '%s'"), fname);
396 0 : return 1;
397 : }
398 : /* Paranoid mode on. */
399 85 : if (preserve_dates
400 0 : && (st.st_ino != pre_st.st_ino || st.st_dev != pre_st.st_dev))
401 : {
402 : /* We detected a race. Try again. */
403 0 : close (fd);
404 0 : goto again;
405 : }
406 :
407 : /* Now get the ELF descriptor. */
408 85 : Elf *elf = elf_begin (fd, output_fname == NULL ? ELF_C_RDWR : ELF_C_READ,
409 : NULL);
410 : int result;
411 85 : switch (elf_kind (elf))
412 : {
413 85 : case ELF_K_ELF:
414 85 : result = handle_elf (fd, elf, NULL, fname, st.st_mode & ACCESSPERMS,
415 85 : preserve_dates ? tv : NULL);
416 85 : break;
417 :
418 0 : case ELF_K_AR:
419 : /* It is not possible to strip the content of an archive direct
420 : the output to a specific file. */
421 0 : if (unlikely (output_fname != NULL || debug_fname != NULL))
422 : {
423 0 : error (0, 0, gettext ("%s: cannot use -o or -f when stripping archive"),
424 : fname);
425 0 : result = 1;
426 : }
427 : else
428 : {
429 : /* We would like to support ar archives, but currently it just
430 : doesn't work at all since we call elf_clone on the members
431 : which doesn't really support ar members.
432 : result = handle_ar (fd, elf, NULL, fname,
433 : preserve_dates ? tv : NULL);
434 : */
435 0 : error (0, 0, gettext ("%s: no support for stripping archive"),
436 : fname);
437 0 : result = 1;
438 : }
439 : break;
440 :
441 0 : default:
442 0 : error (0, 0, gettext ("%s: File format not recognized"), fname);
443 0 : result = 1;
444 0 : break;
445 : }
446 :
447 85 : if (unlikely (elf_end (elf) != 0))
448 0 : INTERNAL_ERROR (fname);
449 :
450 85 : close (fd);
451 :
452 85 : return result;
453 : }
454 :
455 :
456 : /* Maximum size of array allocated on stack. */
457 : #define MAX_STACK_ALLOC (400 * 1024)
458 :
459 : static int
460 85 : handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
461 : mode_t mode, struct timespec tvp[2])
462 : {
463 85 : size_t prefix_len = prefix == NULL ? 0 : strlen (prefix);
464 85 : size_t fname_len = strlen (fname) + 1;
465 85 : char *fullname = alloca (prefix_len + 1 + fname_len);
466 85 : char *cp = fullname;
467 85 : Elf *debugelf = NULL;
468 85 : tmp_debug_fname = NULL;
469 85 : int result = 0;
470 85 : size_t shdridx = 0;
471 : size_t shstrndx;
472 : struct shdr_info
473 : {
474 : Elf_Scn *scn;
475 : GElf_Shdr shdr;
476 : Elf_Data *data;
477 : Elf_Data *debug_data;
478 : const char *name;
479 : Elf32_Word idx; /* Index in new file. */
480 : Elf32_Word old_sh_link; /* Original value of shdr.sh_link. */
481 : Elf32_Word symtab_idx;
482 : Elf32_Word version_idx;
483 : Elf32_Word group_idx;
484 : Elf32_Word group_cnt;
485 : Elf_Scn *newscn;
486 : Dwelf_Strent *se;
487 : Elf32_Word *newsymidx;
488 85 : } *shdr_info = NULL;
489 : Elf_Scn *scn;
490 : size_t cnt;
491 : size_t idx;
492 : bool changes;
493 : GElf_Ehdr newehdr_mem;
494 : GElf_Ehdr *newehdr;
495 : GElf_Ehdr debugehdr_mem;
496 : GElf_Ehdr *debugehdr;
497 85 : Dwelf_Strtab *shst = NULL;
498 : Elf_Data debuglink_crc_data;
499 85 : bool any_symtab_changes = false;
500 85 : Elf_Data *shstrtab_data = NULL;
501 85 : void *debuglink_buf = NULL;
502 :
503 : /* Create the full name of the file. */
504 85 : if (prefix != NULL)
505 : {
506 0 : cp = mempcpy (cp, prefix, prefix_len);
507 0 : *cp++ = ':';
508 : }
509 170 : memcpy (cp, fname, fname_len);
510 :
511 : /* If we are not replacing the input file open a new file here. */
512 85 : if (output_fname != NULL)
513 : {
514 138 : fd = open (output_fname, O_RDWR | O_CREAT, mode);
515 69 : if (unlikely (fd == -1))
516 : {
517 0 : error (0, errno, gettext ("cannot open '%s'"), output_fname);
518 0 : return 1;
519 : }
520 : }
521 :
522 85 : debug_fd = -1;
523 :
524 : /* Get the EBL handling. Removing all debugging symbols with the -g
525 : option or resolving all relocations between debug sections with
526 : the --reloc-debug-sections option are currently the only reasons
527 : we need EBL so don't open the backend unless necessary. */
528 85 : Ebl *ebl = NULL;
529 85 : if (remove_debug || reloc_debug)
530 : {
531 36 : ebl = ebl_openbackend (elf);
532 36 : if (ebl == NULL)
533 : {
534 0 : error (0, errno, gettext ("cannot open EBL backend"));
535 0 : result = 1;
536 0 : goto fail;
537 : }
538 : }
539 :
540 : /* Open the additional file the debug information will be stored in. */
541 85 : if (debug_fname != NULL)
542 : {
543 : /* Create a temporary file name. We do not want to overwrite
544 : the debug file if the file would not contain any
545 : information. */
546 49 : size_t debug_fname_len = strlen (debug_fname);
547 49 : tmp_debug_fname = (char *) xmalloc (debug_fname_len + sizeof (".XXXXXX"));
548 147 : strcpy (mempcpy (tmp_debug_fname, debug_fname, debug_fname_len),
549 : ".XXXXXX");
550 :
551 49 : debug_fd = mkstemp (tmp_debug_fname);
552 49 : if (unlikely (debug_fd == -1))
553 : {
554 0 : error (0, errno, gettext ("cannot open '%s'"), debug_fname);
555 0 : result = 1;
556 0 : goto fail;
557 : }
558 : }
559 :
560 : /* Get the information from the old file. */
561 : GElf_Ehdr ehdr_mem;
562 85 : GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
563 85 : if (ehdr == NULL)
564 0 : INTERNAL_ERROR (fname);
565 :
566 : /* Get the section header string table index. */
567 85 : if (unlikely (elf_getshdrstrndx (elf, &shstrndx) < 0))
568 : {
569 0 : cleanup_debug ();
570 : error (EXIT_FAILURE, 0,
571 0 : gettext ("cannot get section header string table index"));
572 : }
573 :
574 : /* Get the number of phdrs in the old file. */
575 : size_t phnum;
576 85 : if (elf_getphdrnum (elf, &phnum) != 0)
577 : {
578 0 : cleanup_debug ();
579 0 : error (EXIT_FAILURE, 0, gettext ("cannot get number of phdrs"));
580 : }
581 :
582 : /* We now create a new ELF descriptor for the same file. We
583 : construct it almost exactly in the same way with some information
584 : dropped. */
585 : Elf *newelf;
586 85 : if (output_fname != NULL)
587 69 : newelf = elf_begin (fd, ELF_C_WRITE_MMAP, NULL);
588 : else
589 16 : newelf = elf_clone (elf, ELF_C_EMPTY);
590 :
591 85 : if (unlikely (gelf_newehdr (newelf, gelf_getclass (elf)) == 0)
592 85 : || (ehdr->e_type != ET_REL
593 52 : && unlikely (gelf_newphdr (newelf, phnum) == 0)))
594 : {
595 0 : error (0, 0, gettext ("cannot create new file '%s': %s"),
596 0 : output_fname ?: fname, elf_errmsg (-1));
597 : goto fail;
598 : }
599 :
600 : /* Copy over the old program header if needed. */
601 85 : if (ehdr->e_type != ET_REL)
602 440 : for (cnt = 0; cnt < phnum; ++cnt)
603 : {
604 : GElf_Phdr phdr_mem;
605 388 : GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem);
606 388 : if (phdr == NULL
607 388 : || unlikely (gelf_update_phdr (newelf, cnt, phdr) == 0))
608 0 : INTERNAL_ERROR (fname);
609 : }
610 :
611 85 : if (debug_fname != NULL)
612 : {
613 : /* Also create an ELF descriptor for the debug file */
614 49 : debugelf = elf_begin (debug_fd, ELF_C_WRITE_MMAP, NULL);
615 49 : if (unlikely (gelf_newehdr (debugelf, gelf_getclass (elf)) == 0)
616 49 : || (ehdr->e_type != ET_REL
617 23 : && unlikely (gelf_newphdr (debugelf, phnum) == 0)))
618 : {
619 0 : error (0, 0, gettext ("cannot create new file '%s': %s"),
620 : debug_fname, elf_errmsg (-1));
621 : goto fail_close;
622 : }
623 :
624 : /* Copy over the old program header if needed. */
625 49 : if (ehdr->e_type != ET_REL)
626 197 : for (cnt = 0; cnt < phnum; ++cnt)
627 : {
628 : GElf_Phdr phdr_mem;
629 174 : GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem);
630 174 : if (phdr == NULL
631 174 : || unlikely (gelf_update_phdr (debugelf, cnt, phdr) == 0))
632 0 : INTERNAL_ERROR (fname);
633 : }
634 : }
635 :
636 : /* Number of sections. */
637 : size_t shnum;
638 85 : if (unlikely (elf_getshdrnum (elf, &shnum) < 0))
639 : {
640 0 : error (0, 0, gettext ("cannot determine number of sections: %s"),
641 : elf_errmsg (-1));
642 : goto fail_close;
643 : }
644 :
645 85 : if (shstrndx >= shnum)
646 : goto illformed;
647 :
648 : #define elf_assert(test) do { if (!(test)) goto illformed; } while (0)
649 :
650 : /* Storage for section information. We leave room for two more
651 : entries since we unconditionally create a section header string
652 : table. Maybe some weird tool created an ELF file without one.
653 : The other one is used for the debug link section. */
654 85 : if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC)
655 3 : shdr_info = (struct shdr_info *) xcalloc (shnum + 2,
656 : sizeof (struct shdr_info));
657 : else
658 : {
659 82 : shdr_info = (struct shdr_info *) alloca ((shnum + 2)
660 : * sizeof (struct shdr_info));
661 82 : memset (shdr_info, '\0', (shnum + 2) * sizeof (struct shdr_info));
662 : }
663 :
664 : /* Track whether allocated sections all come before non-allocated ones. */
665 85 : bool seen_allocated = false;
666 85 : bool seen_unallocated = false;
667 85 : bool mixed_allocated_unallocated = false;
668 :
669 : /* Prepare section information data structure. */
670 85 : scn = NULL;
671 85 : cnt = 1;
672 199529 : while ((scn = elf_nextscn (elf, scn)) != NULL)
673 : {
674 : /* This should always be true (i.e., there should not be any
675 : holes in the numbering). */
676 199359 : elf_assert (elf_ndxscn (scn) == cnt);
677 :
678 199359 : shdr_info[cnt].scn = scn;
679 :
680 : /* Get the header. */
681 199359 : if (gelf_getshdr (scn, &shdr_info[cnt].shdr) == NULL)
682 0 : INTERNAL_ERROR (fname);
683 :
684 : /* Normally (in non-ET_REL files) we see all allocated sections first,
685 : then all non-allocated. */
686 199359 : if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) == 0)
687 : seen_unallocated = true;
688 : else
689 : {
690 1503 : if (seen_unallocated && seen_allocated)
691 272 : mixed_allocated_unallocated = true;
692 : seen_allocated = true;
693 : }
694 :
695 : /* Get the name of the section. */
696 199359 : shdr_info[cnt].name = elf_strptr (elf, shstrndx,
697 199359 : shdr_info[cnt].shdr.sh_name);
698 199359 : if (shdr_info[cnt].name == NULL)
699 : {
700 0 : illformed:
701 1 : error (0, 0, gettext ("illformed file '%s'"), fname);
702 : goto fail_close;
703 : }
704 :
705 : /* Sanity check the user. */
706 398718 : if (section_name_matches (remove_secs, shdr_info[cnt].name))
707 : {
708 6 : if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) != 0)
709 : {
710 0 : error (0, 0,
711 0 : gettext ("Cannot remove allocated section '%s'"),
712 : shdr_info[cnt].name);
713 0 : result = 1;
714 0 : goto fail_close;
715 : }
716 :
717 12 : if (section_name_matches (keep_secs, shdr_info[cnt].name))
718 : {
719 0 : error (0, 0,
720 0 : gettext ("Cannot both keep and remove section '%s'"),
721 0 : shdr_info[cnt].name);
722 0 : result = 1;
723 0 : goto fail_close;
724 : }
725 : }
726 :
727 : /* Mark them as present but not yet investigated. */
728 199359 : shdr_info[cnt].idx = 1;
729 :
730 : /* Remember the shdr.sh_link value. */
731 199359 : shdr_info[cnt].old_sh_link = shdr_info[cnt].shdr.sh_link;
732 199359 : if (shdr_info[cnt].old_sh_link >= shnum)
733 : goto illformed;
734 :
735 : /* Sections in files other than relocatable object files which
736 : not loaded can be freely moved by us. In theory we can also
737 : freely move around allocated nobits sections. But we don't
738 : to keep the layout of all allocated sections as similar as
739 : possible to the original file. In relocatable object files
740 : everything can be moved. */
741 199359 : if (ehdr->e_type == ET_REL
742 198328 : || (shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) == 0)
743 198166 : shdr_info[cnt].shdr.sh_offset = 0;
744 :
745 : /* If this is an extended section index table store an
746 : appropriate reference. */
747 199359 : if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX))
748 : {
749 0 : elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx == 0);
750 0 : shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx = cnt;
751 : }
752 199359 : else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GROUP))
753 : {
754 : /* Cross-reference the sections contained in the section
755 : group. */
756 6 : shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
757 6 : if (shdr_info[cnt].data == NULL
758 6 : || shdr_info[cnt].data->d_size < sizeof (Elf32_Word))
759 0 : INTERNAL_ERROR (fname);
760 :
761 : /* XXX Fix for unaligned access. */
762 6 : Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
763 : size_t inner;
764 22 : for (inner = 1;
765 16 : inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
766 10 : ++inner)
767 : {
768 10 : if (grpref[inner] < shnum)
769 10 : shdr_info[grpref[inner]].group_idx = cnt;
770 : else
771 : goto illformed;
772 : }
773 :
774 6 : if (inner == 1 || (inner == 2 && (grpref[0] & GRP_COMDAT) == 0))
775 : /* If the section group contains only one element and this
776 : is n COMDAT section we can drop it right away. */
777 0 : shdr_info[cnt].idx = 0;
778 : else
779 6 : shdr_info[cnt].group_cnt = inner - 1;
780 : }
781 199353 : else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GNU_versym))
782 : {
783 52 : elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].version_idx == 0);
784 52 : shdr_info[shdr_info[cnt].shdr.sh_link].version_idx = cnt;
785 : }
786 :
787 : /* If this section is part of a group make sure it is not
788 : discarded right away. */
789 199359 : if ((shdr_info[cnt].shdr.sh_flags & SHF_GROUP) != 0)
790 : {
791 10 : elf_assert (shdr_info[cnt].group_idx != 0);
792 :
793 10 : if (shdr_info[shdr_info[cnt].group_idx].idx == 0)
794 : {
795 : /* The section group section will be removed. */
796 0 : shdr_info[cnt].group_idx = 0;
797 0 : shdr_info[cnt].shdr.sh_flags &= ~SHF_GROUP;
798 : }
799 : }
800 :
801 : /* Increment the counter. */
802 199359 : ++cnt;
803 : }
804 :
805 : /* Now determine which sections can go away. The general rule is that
806 : all sections which are not used at runtime are stripped out. But
807 : there are a few exceptions:
808 :
809 : - special sections named ".comment" and ".note" are kept
810 : - OS or architecture specific sections are kept since we might not
811 : know how to handle them
812 : - if a section is referred to from a section which is not removed
813 : in the sh_link or sh_info element it cannot be removed either
814 : - the user might have explicitly said to remove or keep a section
815 : */
816 199444 : for (cnt = 1; cnt < shnum; ++cnt)
817 : /* Check whether the section can be removed. Since we will create
818 : a new .shstrtab assume it will be removed too. */
819 398718 : if (remove_shdrs ? !(shdr_info[cnt].shdr.sh_flags & SHF_ALLOC)
820 398718 : : (ebl_section_strip_p (ebl, &shdr_info[cnt].shdr,
821 199359 : shdr_info[cnt].name, remove_comment,
822 : remove_debug)
823 67216 : || cnt == shstrndx
824 333741 : || section_name_matches (remove_secs, shdr_info[cnt].name)))
825 : {
826 : /* The user might want to explicitly keep this one. */
827 264348 : if (section_name_matches (keep_secs, shdr_info[cnt].name))
828 6 : continue;
829 :
830 : /* For now assume this section will be removed. */
831 132168 : shdr_info[cnt].idx = 0;
832 :
833 132168 : idx = shdr_info[cnt].group_idx;
834 264337 : while (idx != 0)
835 : {
836 : /* The section group data is already loaded. */
837 9 : elf_assert (shdr_info[idx].data != NULL
838 : && shdr_info[idx].data->d_buf != NULL
839 : && shdr_info[idx].data->d_size >= sizeof (Elf32_Word));
840 :
841 : /* If the references section group is a normal section
842 : group and has one element remaining, or if it is an
843 : empty COMDAT section group it is removed. */
844 6 : bool is_comdat = (((Elf32_Word *) shdr_info[idx].data->d_buf)[0]
845 3 : & GRP_COMDAT) != 0;
846 :
847 3 : --shdr_info[idx].group_cnt;
848 3 : if ((!is_comdat && shdr_info[idx].group_cnt == 1)
849 3 : || (is_comdat && shdr_info[idx].group_cnt == 0))
850 : {
851 1 : shdr_info[idx].idx = 0;
852 : /* Continue recursively. */
853 1 : idx = shdr_info[idx].group_idx;
854 : }
855 : else
856 : break;
857 : }
858 : }
859 :
860 : /* Mark the SHT_NULL section as handled. */
861 85 : shdr_info[0].idx = 2;
862 :
863 :
864 : /* Handle exceptions: section groups and cross-references. We might
865 : have to repeat this a few times since the resetting of the flag
866 : might propagate. */
867 : do
868 : {
869 85 : changes = false;
870 :
871 199444 : for (cnt = 1; cnt < shnum; ++cnt)
872 : {
873 199359 : if (shdr_info[cnt].idx == 0)
874 : {
875 : /* If a relocation section is marked as being removed make
876 : sure the section it is relocating is removed, too. */
877 264212 : if (shdr_info[cnt].shdr.sh_type == SHT_REL
878 132106 : || shdr_info[cnt].shdr.sh_type == SHT_RELA)
879 : {
880 311 : if (shdr_info[cnt].shdr.sh_info >= shnum)
881 : goto illformed;
882 311 : else if (shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0)
883 148 : shdr_info[cnt].idx = 1;
884 : }
885 :
886 : /* If a group section is marked as being removed make
887 : sure all the sections it contains are being removed, too. */
888 132106 : if (shdr_info[cnt].shdr.sh_type == SHT_GROUP)
889 : {
890 : Elf32_Word *grpref;
891 6 : grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
892 13 : for (size_t in = 1;
893 7 : in < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
894 1 : ++in)
895 6 : if (grpref[in] < shnum)
896 : {
897 6 : if (shdr_info[grpref[in]].idx != 0)
898 : {
899 5 : shdr_info[cnt].idx = 1;
900 5 : break;
901 : }
902 : }
903 : else
904 : goto illformed;
905 : }
906 : }
907 :
908 199359 : if (shdr_info[cnt].idx == 1)
909 : {
910 : /* The content of symbol tables we don't remove must not
911 : reference any section which we do remove. Otherwise
912 : we cannot remove the section. */
913 67406 : if (debug_fname != NULL
914 66607 : && shdr_info[cnt].debug_data == NULL
915 133102 : && (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM
916 66551 : || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB))
917 : {
918 : /* Make sure the data is loaded. */
919 29 : if (shdr_info[cnt].data == NULL)
920 : {
921 : shdr_info[cnt].data
922 29 : = elf_getdata (shdr_info[cnt].scn, NULL);
923 29 : if (shdr_info[cnt].data == NULL)
924 0 : INTERNAL_ERROR (fname);
925 : }
926 29 : Elf_Data *symdata = shdr_info[cnt].data;
927 :
928 : /* If there is an extended section index table load it
929 : as well. */
930 29 : if (shdr_info[cnt].symtab_idx != 0
931 0 : && shdr_info[shdr_info[cnt].symtab_idx].data == NULL)
932 : {
933 0 : elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB);
934 :
935 : shdr_info[shdr_info[cnt].symtab_idx].data
936 0 : = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
937 : NULL);
938 0 : if (shdr_info[shdr_info[cnt].symtab_idx].data == NULL)
939 0 : INTERNAL_ERROR (fname);
940 : }
941 29 : Elf_Data *xndxdata
942 29 : = shdr_info[shdr_info[cnt].symtab_idx].data;
943 :
944 : /* Go through all symbols and make sure the section they
945 : reference is not removed. */
946 29 : size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
947 :
948 1075 : for (size_t inner = 0;
949 1046 : inner < shdr_info[cnt].data->d_size / elsize;
950 1017 : ++inner)
951 : {
952 : GElf_Sym sym_mem;
953 : Elf32_Word xndx;
954 1017 : GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
955 : inner, &sym_mem,
956 : &xndx);
957 1017 : if (sym == NULL)
958 0 : INTERNAL_ERROR (fname);
959 :
960 1017 : size_t scnidx = sym->st_shndx;
961 1017 : if (scnidx == SHN_UNDEF || scnidx >= shnum
962 555 : || (scnidx >= SHN_LORESERVE
963 : && scnidx <= SHN_HIRESERVE
964 555 : && scnidx != SHN_XINDEX)
965 : /* Don't count in the section symbols. */
966 544 : || GELF_ST_TYPE (sym->st_info) == STT_SECTION)
967 : /* This is no section index, leave it alone. */
968 699 : continue;
969 318 : else if (scnidx == SHN_XINDEX)
970 0 : scnidx = xndx;
971 :
972 318 : if (scnidx >= shnum)
973 : goto illformed;
974 :
975 318 : if (shdr_info[scnidx].idx == 0)
976 : /* This symbol table has a real symbol in
977 : a discarded section. So preserve the
978 : original table in the debug file. Unless
979 : it is a redundant data marker to a debug
980 : (data only) section. */
981 12 : if (! (ebl_section_strip_p (ebl,
982 4 : &shdr_info[scnidx].shdr,
983 : shdr_info[scnidx].name,
984 : remove_comment,
985 : remove_debug)
986 4 : && ebl_data_marker_symbol (ebl, sym,
987 8 : elf_strptr (elf,
988 4 : shdr_info[cnt].shdr.sh_link,
989 4 : sym->st_name))))
990 0 : shdr_info[cnt].debug_data = symdata;
991 : }
992 : }
993 :
994 : /* Cross referencing happens:
995 : - for the cases the ELF specification says. That are
996 : + SHT_DYNAMIC in sh_link to string table
997 : + SHT_HASH in sh_link to symbol table
998 : + SHT_REL and SHT_RELA in sh_link to symbol table
999 : + SHT_SYMTAB and SHT_DYNSYM in sh_link to string table
1000 : + SHT_GROUP in sh_link to symbol table
1001 : + SHT_SYMTAB_SHNDX in sh_link to symbol table
1002 : Other (OS or architecture-specific) sections might as
1003 : well use this field so we process it unconditionally.
1004 : - references inside section groups
1005 : - specially marked references in sh_info if the SHF_INFO_LINK
1006 : flag is set
1007 : */
1008 :
1009 67406 : if (shdr_info[shdr_info[cnt].shdr.sh_link].idx == 0)
1010 : {
1011 62 : shdr_info[shdr_info[cnt].shdr.sh_link].idx = 1;
1012 62 : changes |= shdr_info[cnt].shdr.sh_link < cnt;
1013 : }
1014 :
1015 : /* Handle references through sh_info. */
1016 67406 : if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
1017 : {
1018 251 : if (shdr_info[cnt].shdr.sh_info >= shnum)
1019 : goto illformed;
1020 251 : else if ( shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0)
1021 : {
1022 0 : shdr_info[shdr_info[cnt].shdr.sh_info].idx = 1;
1023 0 : changes |= shdr_info[cnt].shdr.sh_info < cnt;
1024 : }
1025 : }
1026 :
1027 : /* Mark the section as investigated. */
1028 67406 : shdr_info[cnt].idx = 2;
1029 : }
1030 :
1031 199359 : if (debug_fname != NULL
1032 132671 : && (shdr_info[cnt].idx == 0 || shdr_info[cnt].debug_data != NULL))
1033 : {
1034 : /* This section is being preserved in the debug file.
1035 : Sections it refers to must be preserved there too.
1036 :
1037 : In this pass we mark sections to be preserved in both
1038 : files by setting the .debug_data pointer to the original
1039 : file's .data pointer. Below, we'll copy the section
1040 : contents. */
1041 :
1042 66248 : inline void check_preserved (size_t i)
1043 : {
1044 66248 : if (i != 0 && i < shnum + 2 && shdr_info[i].idx != 0
1045 159 : && shdr_info[i].debug_data == NULL)
1046 : {
1047 56 : if (shdr_info[i].data == NULL)
1048 56 : shdr_info[i].data = elf_getdata (shdr_info[i].scn, NULL);
1049 56 : if (shdr_info[i].data == NULL)
1050 0 : INTERNAL_ERROR (fname);
1051 :
1052 56 : shdr_info[i].debug_data = shdr_info[i].data;
1053 56 : changes |= i < cnt;
1054 : }
1055 66248 : }
1056 :
1057 66120 : check_preserved (shdr_info[cnt].shdr.sh_link);
1058 66120 : if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
1059 128 : check_preserved (shdr_info[cnt].shdr.sh_info);
1060 : }
1061 : }
1062 : }
1063 85 : while (changes);
1064 :
1065 : /* Copy the removed sections to the debug output file.
1066 : The ones that are not removed in the stripped file are SHT_NOBITS. */
1067 85 : if (debug_fname != NULL)
1068 : {
1069 132720 : for (cnt = 1; cnt < shnum; ++cnt)
1070 : {
1071 132671 : scn = elf_newscn (debugelf);
1072 132671 : if (scn == NULL)
1073 : {
1074 0 : cleanup_debug ();
1075 0 : error (EXIT_FAILURE, 0,
1076 0 : gettext ("while generating output file: %s"),
1077 : elf_errmsg (-1));
1078 : }
1079 :
1080 265342 : bool discard_section = (shdr_info[cnt].idx > 0
1081 66607 : && shdr_info[cnt].debug_data == NULL
1082 66551 : && shdr_info[cnt].shdr.sh_type != SHT_NOTE
1083 66493 : && shdr_info[cnt].shdr.sh_type != SHT_GROUP
1084 199159 : && cnt != shstrndx);
1085 :
1086 : /* Set the section header in the new file. */
1087 132671 : GElf_Shdr debugshdr = shdr_info[cnt].shdr;
1088 132671 : if (discard_section)
1089 66488 : debugshdr.sh_type = SHT_NOBITS;
1090 :
1091 132671 : if (unlikely (gelf_update_shdr (scn, &debugshdr) == 0))
1092 : /* There cannot be any overflows. */
1093 0 : INTERNAL_ERROR (fname);
1094 :
1095 : /* Get the data from the old file if necessary. */
1096 132671 : if (shdr_info[cnt].data == NULL)
1097 : {
1098 132580 : shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
1099 132580 : if (shdr_info[cnt].data == NULL)
1100 0 : INTERNAL_ERROR (fname);
1101 : }
1102 :
1103 : /* Set the data. This is done by copying from the old file. */
1104 132671 : Elf_Data *debugdata = elf_newdata (scn);
1105 132671 : if (debugdata == NULL)
1106 0 : INTERNAL_ERROR (fname);
1107 :
1108 : /* Copy the structure. This data may be modified in place
1109 : before we write out the file. */
1110 132671 : *debugdata = *shdr_info[cnt].data;
1111 132671 : if (discard_section)
1112 66488 : debugdata->d_buf = NULL;
1113 66183 : else if (shdr_info[cnt].debug_data != NULL
1114 66127 : || shdr_info[cnt].shdr.sh_type == SHT_GROUP)
1115 : {
1116 : /* Copy the original data before it gets modified. */
1117 62 : shdr_info[cnt].debug_data = debugdata;
1118 62 : if (debugdata->d_buf == NULL)
1119 0 : INTERNAL_ERROR (fname);
1120 124 : debugdata->d_buf = memcpy (xmalloc (debugdata->d_size),
1121 : debugdata->d_buf, debugdata->d_size);
1122 : }
1123 : }
1124 :
1125 : /* Finish the ELF header. Fill in the fields not handled by
1126 : libelf from the old file. */
1127 49 : debugehdr = gelf_getehdr (debugelf, &debugehdr_mem);
1128 49 : if (debugehdr == NULL)
1129 0 : INTERNAL_ERROR (fname);
1130 :
1131 98 : memcpy (debugehdr->e_ident, ehdr->e_ident, EI_NIDENT);
1132 49 : debugehdr->e_type = ehdr->e_type;
1133 49 : debugehdr->e_machine = ehdr->e_machine;
1134 49 : debugehdr->e_version = ehdr->e_version;
1135 49 : debugehdr->e_entry = ehdr->e_entry;
1136 49 : debugehdr->e_flags = ehdr->e_flags;
1137 :
1138 : size_t shdrstrndx;
1139 49 : if (elf_getshdrstrndx (elf, &shdrstrndx) < 0)
1140 : {
1141 0 : error (0, 0, gettext ("%s: error while getting shdrstrndx: %s"),
1142 : fname, elf_errmsg (-1));
1143 0 : result = 1;
1144 0 : goto fail_close;
1145 : }
1146 :
1147 49 : if (shstrndx < SHN_LORESERVE)
1148 47 : debugehdr->e_shstrndx = shdrstrndx;
1149 : else
1150 : {
1151 2 : debugehdr->e_shstrndx = SHN_XINDEX;
1152 2 : Elf_Scn *scn0 = elf_getscn (debugelf, 0);
1153 : GElf_Shdr shdr0_mem;
1154 2 : GElf_Shdr *shdr0 = gelf_getshdr (scn0, &shdr0_mem);
1155 2 : if (shdr0 == NULL)
1156 : {
1157 0 : error (0, 0, gettext ("%s: error getting zero section: %s"),
1158 : debug_fname, elf_errmsg (-1));
1159 0 : result = 1;
1160 0 : goto fail_close;
1161 : }
1162 :
1163 2 : shdr0->sh_link = shdrstrndx;
1164 2 : if (gelf_update_shdr (scn0, shdr0) == 0)
1165 : {
1166 0 : error (0, 0, gettext ("%s: error while updating zero section: %s"),
1167 : debug_fname, elf_errmsg (-1));
1168 0 : result = 1;
1169 0 : goto fail_close;
1170 : }
1171 :
1172 : }
1173 :
1174 49 : if (unlikely (gelf_update_ehdr (debugelf, debugehdr) == 0))
1175 : {
1176 0 : error (0, 0, gettext ("%s: error while creating ELF header: %s"),
1177 : debug_fname, elf_errmsg (-1));
1178 0 : result = 1;
1179 0 : goto fail_close;
1180 : }
1181 : }
1182 :
1183 : /* Although we always create a new section header string table we
1184 : don't explicitly mark the existing one as unused. It can still
1185 : be used through a symbol table section we are keeping. If not it
1186 : will already be marked as unused. */
1187 :
1188 : /* We need a string table for the section headers. */
1189 85 : shst = dwelf_strtab_init (true);
1190 85 : if (shst == NULL)
1191 : {
1192 0 : cleanup_debug ();
1193 0 : error (EXIT_FAILURE, errno, gettext ("while preparing output for '%s'"),
1194 0 : output_fname ?: fname);
1195 : }
1196 :
1197 : /* Assign new section numbers. */
1198 85 : shdr_info[0].idx = 0;
1199 199444 : for (cnt = idx = 1; cnt < shnum; ++cnt)
1200 199359 : if (shdr_info[cnt].idx > 0)
1201 : {
1202 67406 : shdr_info[cnt].idx = idx++;
1203 :
1204 : /* Create a new section. */
1205 67406 : shdr_info[cnt].newscn = elf_newscn (newelf);
1206 67406 : if (shdr_info[cnt].newscn == NULL)
1207 : {
1208 0 : cleanup_debug ();
1209 0 : error (EXIT_FAILURE, 0,
1210 0 : gettext ("while generating output file: %s"),
1211 : elf_errmsg (-1));
1212 : }
1213 :
1214 67406 : elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
1215 :
1216 : /* Add this name to the section header string table. */
1217 67406 : shdr_info[cnt].se = dwelf_strtab_add (shst, shdr_info[cnt].name);
1218 : }
1219 :
1220 : /* Test whether we are doing anything at all. Either all removable
1221 : sections are already gone. Or the only section we would remove is
1222 : the .shstrtab section which we would add again. */
1223 255 : bool removing_sections = !(cnt == idx
1224 85 : || (cnt == idx + 1
1225 4 : && shdr_info[shstrndx].idx == 0));
1226 85 : if (output_fname == NULL && !removing_sections)
1227 : goto fail_close;
1228 :
1229 : /* Create the reference to the file with the debug info (if any). */
1230 83 : if (debug_fname != NULL && !remove_shdrs && removing_sections)
1231 : {
1232 : /* Add the section header string table section name. */
1233 47 : shdr_info[cnt].se = dwelf_strtab_add_len (shst, ".gnu_debuglink", 15);
1234 47 : shdr_info[cnt].idx = idx++;
1235 :
1236 : /* Create the section header. */
1237 47 : shdr_info[cnt].shdr.sh_type = SHT_PROGBITS;
1238 47 : shdr_info[cnt].shdr.sh_flags = 0;
1239 47 : shdr_info[cnt].shdr.sh_addr = 0;
1240 47 : shdr_info[cnt].shdr.sh_link = SHN_UNDEF;
1241 47 : shdr_info[cnt].shdr.sh_info = SHN_UNDEF;
1242 47 : shdr_info[cnt].shdr.sh_entsize = 0;
1243 47 : shdr_info[cnt].shdr.sh_addralign = 4;
1244 : /* We set the offset to zero here. Before we write the ELF file the
1245 : field must have the correct value. This is done in the final
1246 : loop over all section. Then we have all the information needed. */
1247 47 : shdr_info[cnt].shdr.sh_offset = 0;
1248 :
1249 : /* Create the section. */
1250 47 : shdr_info[cnt].newscn = elf_newscn (newelf);
1251 47 : if (shdr_info[cnt].newscn == NULL)
1252 : {
1253 0 : cleanup_debug ();
1254 0 : error (EXIT_FAILURE, 0,
1255 0 : gettext ("while create section header section: %s"),
1256 : elf_errmsg (-1));
1257 : }
1258 47 : elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
1259 :
1260 47 : shdr_info[cnt].data = elf_newdata (shdr_info[cnt].newscn);
1261 47 : if (shdr_info[cnt].data == NULL)
1262 : {
1263 0 : cleanup_debug ();
1264 0 : error (EXIT_FAILURE, 0, gettext ("cannot allocate section data: %s"),
1265 : elf_errmsg (-1));
1266 : }
1267 :
1268 47 : char *debug_basename = basename (debug_fname_embed ?: debug_fname);
1269 47 : off_t crc_offset = strlen (debug_basename) + 1;
1270 : /* Align to 4 byte boundary */
1271 47 : crc_offset = ((crc_offset - 1) & ~3) + 4;
1272 :
1273 47 : shdr_info[cnt].data->d_align = 4;
1274 47 : shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size
1275 47 : = crc_offset + 4;
1276 47 : debuglink_buf = xcalloc (1, shdr_info[cnt].data->d_size);
1277 47 : shdr_info[cnt].data->d_buf = debuglink_buf;
1278 :
1279 94 : strcpy (shdr_info[cnt].data->d_buf, debug_basename);
1280 :
1281 : /* Cache this Elf_Data describing the CRC32 word in the section.
1282 : We'll fill this in when we have written the debug file. */
1283 47 : debuglink_crc_data = *shdr_info[cnt].data;
1284 94 : debuglink_crc_data.d_buf = ((char *) debuglink_crc_data.d_buf
1285 47 : + crc_offset);
1286 47 : debuglink_crc_data.d_size = 4;
1287 :
1288 : /* One more section done. */
1289 47 : ++cnt;
1290 : }
1291 :
1292 : /* Index of the section header table in the shdr_info array. */
1293 83 : shdridx = cnt;
1294 :
1295 : /* Add the section header string table section name. */
1296 83 : shdr_info[cnt].se = dwelf_strtab_add_len (shst, ".shstrtab", 10);
1297 83 : shdr_info[cnt].idx = idx;
1298 :
1299 : /* Create the section header. */
1300 83 : shdr_info[cnt].shdr.sh_type = SHT_STRTAB;
1301 83 : shdr_info[cnt].shdr.sh_flags = 0;
1302 83 : shdr_info[cnt].shdr.sh_addr = 0;
1303 83 : shdr_info[cnt].shdr.sh_link = SHN_UNDEF;
1304 83 : shdr_info[cnt].shdr.sh_info = SHN_UNDEF;
1305 83 : shdr_info[cnt].shdr.sh_entsize = 0;
1306 : /* We set the offset to zero here. Before we write the ELF file the
1307 : field must have the correct value. This is done in the final
1308 : loop over all section. Then we have all the information needed. */
1309 83 : shdr_info[cnt].shdr.sh_offset = 0;
1310 83 : shdr_info[cnt].shdr.sh_addralign = 1;
1311 :
1312 : /* Create the section. */
1313 83 : shdr_info[cnt].newscn = elf_newscn (newelf);
1314 83 : if (shdr_info[cnt].newscn == NULL)
1315 : {
1316 0 : cleanup_debug ();
1317 0 : error (EXIT_FAILURE, 0,
1318 0 : gettext ("while create section header section: %s"),
1319 : elf_errmsg (-1));
1320 : }
1321 83 : elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == idx);
1322 :
1323 : /* Finalize the string table and fill in the correct indices in the
1324 : section headers. */
1325 83 : shstrtab_data = elf_newdata (shdr_info[cnt].newscn);
1326 83 : if (shstrtab_data == NULL)
1327 : {
1328 0 : cleanup_debug ();
1329 0 : error (EXIT_FAILURE, 0,
1330 0 : gettext ("while create section header string table: %s"),
1331 : elf_errmsg (-1));
1332 : }
1333 83 : if (dwelf_strtab_finalize (shst, shstrtab_data) == NULL)
1334 : {
1335 0 : cleanup_debug ();
1336 : error (EXIT_FAILURE, 0,
1337 0 : gettext ("no memory to create section header string table"));
1338 : }
1339 :
1340 : /* We have to set the section size. */
1341 83 : shdr_info[cnt].shdr.sh_size = shstrtab_data->d_size;
1342 :
1343 : /* Update the section information. */
1344 83 : GElf_Off lastoffset = 0;
1345 133980 : for (cnt = 1; cnt <= shdridx; ++cnt)
1346 133898 : if (shdr_info[cnt].idx > 0)
1347 : {
1348 : Elf_Data *newdata;
1349 :
1350 1948 : scn = elf_getscn (newelf, shdr_info[cnt].idx);
1351 1948 : elf_assert (scn != NULL);
1352 :
1353 : /* Update the name. */
1354 1948 : shdr_info[cnt].shdr.sh_name = dwelf_strent_off (shdr_info[cnt].se);
1355 :
1356 : /* Update the section header from the input file. Some fields
1357 : might be section indeces which now have to be adjusted. Keep
1358 : the index to the "current" sh_link in case we need it to lookup
1359 : symbol table names. */
1360 1948 : size_t sh_link = shdr_info[cnt].shdr.sh_link;
1361 1948 : if (shdr_info[cnt].shdr.sh_link != 0)
1362 561 : shdr_info[cnt].shdr.sh_link =
1363 561 : shdr_info[shdr_info[cnt].shdr.sh_link].idx;
1364 :
1365 1948 : if (shdr_info[cnt].shdr.sh_type == SHT_GROUP)
1366 : {
1367 10 : elf_assert (shdr_info[cnt].data != NULL
1368 : && shdr_info[cnt].data->d_buf != NULL);
1369 :
1370 : Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
1371 19 : for (size_t inner = 0;
1372 19 : inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
1373 14 : ++inner)
1374 14 : if (grpref[inner] < shnum)
1375 14 : grpref[inner] = shdr_info[grpref[inner]].idx;
1376 : else
1377 : goto illformed;
1378 : }
1379 :
1380 : /* Handle the SHT_REL, SHT_RELA, and SHF_INFO_LINK flag. */
1381 1948 : if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
1382 249 : shdr_info[cnt].shdr.sh_info =
1383 249 : shdr_info[shdr_info[cnt].shdr.sh_info].idx;
1384 :
1385 : /* Get the data from the old file if necessary. We already
1386 : created the data for the section header string table. */
1387 1948 : if (cnt < shnum)
1388 : {
1389 1820 : if (shdr_info[cnt].data == NULL)
1390 : {
1391 774 : shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
1392 774 : if (shdr_info[cnt].data == NULL)
1393 0 : INTERNAL_ERROR (fname);
1394 : }
1395 :
1396 : /* Set the data. This is done by copying from the old file. */
1397 1820 : newdata = elf_newdata (scn);
1398 1820 : if (newdata == NULL)
1399 0 : INTERNAL_ERROR (fname);
1400 :
1401 : /* Copy the structure. */
1402 1820 : *newdata = *shdr_info[cnt].data;
1403 :
1404 : /* We know the size. */
1405 1820 : shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size;
1406 :
1407 : /* We have to adjust symbol tables. The st_shndx member might
1408 : have to be updated. */
1409 3640 : if (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM
1410 1820 : || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB)
1411 : {
1412 99 : Elf_Data *versiondata = NULL;
1413 99 : Elf_Data *shndxdata = NULL;
1414 :
1415 99 : size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1416 :
1417 99 : if (shdr_info[cnt].symtab_idx != 0)
1418 : {
1419 0 : elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX);
1420 : /* This section has extended section information.
1421 : We have to modify that information, too. */
1422 0 : shndxdata = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
1423 : NULL);
1424 :
1425 0 : elf_assert (shndxdata != NULL
1426 : && shndxdata->d_buf != NULL
1427 : && ((shndxdata->d_size / sizeof (Elf32_Word))
1428 : >= shdr_info[cnt].data->d_size / elsize));
1429 : }
1430 :
1431 99 : if (shdr_info[cnt].version_idx != 0)
1432 : {
1433 50 : elf_assert (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM);
1434 : /* This section has associated version
1435 : information. We have to modify that
1436 : information, too. */
1437 50 : versiondata = elf_getdata (shdr_info[shdr_info[cnt].version_idx].scn,
1438 : NULL);
1439 :
1440 150 : elf_assert (versiondata != NULL
1441 : && versiondata->d_buf != NULL
1442 : && ((versiondata->d_size / sizeof (GElf_Versym))
1443 : >= shdr_info[cnt].data->d_size / elsize));
1444 : }
1445 :
1446 : shdr_info[cnt].newsymidx
1447 99 : = (Elf32_Word *) xcalloc (shdr_info[cnt].data->d_size
1448 : / elsize, sizeof (Elf32_Word));
1449 :
1450 99 : bool last_was_local = true;
1451 : size_t destidx;
1452 : size_t inner;
1453 18911 : for (destidx = inner = 1;
1454 18812 : inner < shdr_info[cnt].data->d_size / elsize;
1455 18713 : ++inner)
1456 : {
1457 : Elf32_Word sec;
1458 : GElf_Sym sym_mem;
1459 : Elf32_Word xshndx;
1460 18714 : GElf_Sym *sym = gelf_getsymshndx (shdr_info[cnt].data,
1461 : shndxdata, inner,
1462 : &sym_mem, &xshndx);
1463 18714 : if (sym == NULL)
1464 0 : INTERNAL_ERROR (fname);
1465 :
1466 18714 : if (sym->st_shndx == SHN_UNDEF
1467 17121 : || (sym->st_shndx >= shnum
1468 256 : && sym->st_shndx != SHN_XINDEX))
1469 : {
1470 : /* This is no section index, leave it alone
1471 : unless it is moved. */
1472 1849 : if (destidx != inner
1473 1362 : && gelf_update_symshndx (shdr_info[cnt].data,
1474 : shndxdata,
1475 : destidx, sym,
1476 : xshndx) == 0)
1477 0 : INTERNAL_ERROR (fname);
1478 :
1479 1849 : shdr_info[cnt].newsymidx[inner] = destidx++;
1480 :
1481 1849 : if (last_was_local
1482 241 : && GELF_ST_BIND (sym->st_info) != STB_LOCAL)
1483 : {
1484 59 : last_was_local = false;
1485 59 : shdr_info[cnt].shdr.sh_info = destidx - 1;
1486 : }
1487 :
1488 1849 : continue;
1489 : }
1490 :
1491 : /* Get the full section index, if necessary from the
1492 : XINDEX table. */
1493 16865 : if (sym->st_shndx == SHN_XINDEX)
1494 0 : elf_assert (shndxdata != NULL
1495 : && shndxdata->d_buf != NULL);
1496 16865 : size_t sidx = (sym->st_shndx != SHN_XINDEX
1497 16865 : ? sym->st_shndx : xshndx);
1498 16865 : sec = shdr_info[sidx].idx;
1499 :
1500 16865 : if (sec != 0)
1501 : {
1502 : GElf_Section nshndx;
1503 : Elf32_Word nxshndx;
1504 :
1505 2589 : if (sec < SHN_LORESERVE)
1506 : {
1507 2588 : nshndx = sec;
1508 2588 : nxshndx = 0;
1509 : }
1510 : else
1511 : {
1512 : nshndx = SHN_XINDEX;
1513 : nxshndx = sec;
1514 : }
1515 :
1516 2589 : elf_assert (sec < SHN_LORESERVE || shndxdata != NULL);
1517 :
1518 2588 : if ((inner != destidx || nshndx != sym->st_shndx
1519 1299 : || (shndxdata != NULL && nxshndx != xshndx))
1520 2578 : && (sym->st_shndx = nshndx,
1521 1289 : gelf_update_symshndx (shdr_info[cnt].data,
1522 : shndxdata,
1523 : destidx, sym,
1524 : nxshndx) == 0))
1525 0 : INTERNAL_ERROR (fname);
1526 :
1527 2588 : shdr_info[cnt].newsymidx[inner] = destidx++;
1528 :
1529 2588 : if (last_was_local
1530 2172 : && GELF_ST_BIND (sym->st_info) != STB_LOCAL)
1531 : {
1532 39 : last_was_local = false;
1533 39 : shdr_info[cnt].shdr.sh_info = destidx - 1;
1534 : }
1535 : }
1536 14276 : else if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) != 0
1537 48 : && GELF_ST_TYPE (sym->st_info) != STT_SECTION
1538 0 : && shdr_info[sidx].shdr.sh_type != SHT_GROUP)
1539 : {
1540 : /* Removing a real symbol from an allocated
1541 : symbol table is hard and probably a
1542 : mistake. Really removing it means
1543 : rewriting the dynamic segment and hash
1544 : sections. Just warn and set the symbol
1545 : section to UNDEF. */
1546 0 : error (0, 0,
1547 0 : gettext ("Cannot remove symbol [%zd] from allocated symbol table [%zd]"), inner, cnt);
1548 0 : sym->st_shndx = SHN_UNDEF;
1549 0 : if (gelf_update_sym (shdr_info[cnt].data, destidx,
1550 : sym) == 0)
1551 0 : INTERNAL_ERROR (fname);
1552 0 : shdr_info[cnt].newsymidx[inner] = destidx++;
1553 : }
1554 14276 : else if (debug_fname != NULL
1555 14098 : && shdr_info[cnt].debug_data == NULL)
1556 : /* The symbol points to a section that is discarded
1557 : but isn't preserved in the debug file. Check that
1558 : this is a section or group signature symbol
1559 : for a section which has been removed. Or a special
1560 : data marker symbol to a debug section. */
1561 : {
1562 50 : elf_assert (GELF_ST_TYPE (sym->st_info) == STT_SECTION
1563 : || ((shdr_info[sidx].shdr.sh_type
1564 : == SHT_GROUP)
1565 : && (shdr_info[sidx].shdr.sh_info
1566 : == inner))
1567 : || ebl_data_marker_symbol (ebl, sym,
1568 : elf_strptr (elf, sh_link,
1569 : sym->st_name)));
1570 : }
1571 : }
1572 :
1573 98 : if (destidx != inner)
1574 : {
1575 : /* The size of the symbol table changed. */
1576 54 : shdr_info[cnt].shdr.sh_size = newdata->d_size
1577 54 : = destidx * elsize;
1578 54 : any_symtab_changes = true;
1579 : }
1580 : else
1581 : {
1582 : /* The symbol table didn't really change. */
1583 44 : free (shdr_info[cnt].newsymidx);
1584 44 : shdr_info[cnt].newsymidx = NULL;
1585 : }
1586 : }
1587 : }
1588 :
1589 : /* If we have to, compute the offset of the section.
1590 : If allocate and unallocated sections are mixed, we only update
1591 : the allocated ones now. The unallocated ones come second. */
1592 1947 : if (! mixed_allocated_unallocated
1593 860 : || (shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) != 0)
1594 : {
1595 1583 : if (shdr_info[cnt].shdr.sh_offset == 0)
1596 : shdr_info[cnt].shdr.sh_offset
1597 876 : = ((lastoffset + shdr_info[cnt].shdr.sh_addralign - 1)
1598 438 : & ~((GElf_Off) (shdr_info[cnt].shdr.sh_addralign - 1)));
1599 :
1600 : /* Set the section header in the new file. */
1601 1583 : if (unlikely (gelf_update_shdr (scn, &shdr_info[cnt].shdr) == 0))
1602 : /* There cannot be any overflows. */
1603 0 : INTERNAL_ERROR (fname);
1604 :
1605 : /* Remember the last section written so far. */
1606 3166 : GElf_Off filesz = (shdr_info[cnt].shdr.sh_type != SHT_NOBITS
1607 1583 : ? shdr_info[cnt].shdr.sh_size : 0);
1608 1583 : if (lastoffset < shdr_info[cnt].shdr.sh_offset + filesz)
1609 1484 : lastoffset = shdr_info[cnt].shdr.sh_offset + filesz;
1610 : }
1611 : }
1612 :
1613 : /* We might have to update the unallocated sections after we done the
1614 : allocated ones. lastoffset is set to right after the last allocated
1615 : section. */
1616 82 : if (mixed_allocated_unallocated)
1617 132483 : for (cnt = 1; cnt <= shdridx; ++cnt)
1618 132441 : if (shdr_info[cnt].idx > 0)
1619 : {
1620 835 : scn = elf_getscn (newelf, shdr_info[cnt].idx);
1621 835 : if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) == 0)
1622 : {
1623 360 : if (shdr_info[cnt].shdr.sh_offset == 0)
1624 : shdr_info[cnt].shdr.sh_offset
1625 720 : = ((lastoffset + shdr_info[cnt].shdr.sh_addralign - 1)
1626 360 : & ~((GElf_Off) (shdr_info[cnt].shdr.sh_addralign - 1)));
1627 :
1628 : /* Set the section header in the new file. */
1629 360 : if (unlikely (gelf_update_shdr (scn, &shdr_info[cnt].shdr) == 0))
1630 : /* There cannot be any overflows. */
1631 0 : INTERNAL_ERROR (fname);
1632 :
1633 : /* Remember the last section written so far. */
1634 720 : GElf_Off filesz = (shdr_info[cnt].shdr.sh_type != SHT_NOBITS
1635 360 : ? shdr_info[cnt].shdr.sh_size : 0);
1636 360 : if (lastoffset < shdr_info[cnt].shdr.sh_offset + filesz)
1637 357 : lastoffset = shdr_info[cnt].shdr.sh_offset + filesz;
1638 : }
1639 : }
1640 :
1641 : /* Adjust symbol references if symbol tables changed. */
1642 82 : if (any_symtab_changes)
1643 : /* Find all relocation sections which use this symbol table. */
1644 1807 : for (cnt = 1; cnt <= shdridx; ++cnt)
1645 : {
1646 : /* Update section headers when the data size has changed.
1647 : We also update the SHT_NOBITS section in the debug
1648 : file so that the section headers match in sh_size. */
1649 12 : inline void update_section_size (const Elf_Data *newdata)
1650 : {
1651 : GElf_Shdr shdr_mem;
1652 12 : GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
1653 12 : shdr->sh_size = newdata->d_size;
1654 12 : (void) gelf_update_shdr (scn, shdr);
1655 12 : if (debugelf != NULL)
1656 : {
1657 : /* libelf will use d_size to set sh_size. */
1658 2 : Elf_Data *debugdata = elf_getdata (elf_getscn (debugelf,
1659 : cnt), NULL);
1660 2 : if (debugdata == NULL)
1661 0 : INTERNAL_ERROR (fname);
1662 2 : debugdata->d_size = newdata->d_size;
1663 : }
1664 12 : }
1665 :
1666 1755 : if (shdr_info[cnt].idx == 0 && debug_fname == NULL)
1667 : /* Ignore sections which are discarded. When we are saving a
1668 : relocation section in a separate debug file, we must fix up
1669 : the symbol table references. */
1670 211 : continue;
1671 :
1672 1544 : const Elf32_Word symtabidx = shdr_info[cnt].old_sh_link;
1673 1544 : elf_assert (symtabidx < shnum + 2);
1674 1544 : const Elf32_Word *const newsymidx = shdr_info[symtabidx].newsymidx;
1675 1544 : switch (shdr_info[cnt].shdr.sh_type)
1676 : {
1677 : inline bool no_symtab_updates (void)
1678 : {
1679 : /* If the symbol table hasn't changed, do not do anything. */
1680 356 : if (shdr_info[symtabidx].newsymidx == NULL)
1681 : return true;
1682 :
1683 : /* If the symbol table is not discarded, but additionally
1684 : duplicated in the separate debug file and this section
1685 : is discarded, don't adjust anything. */
1686 : return (shdr_info[cnt].idx == 0
1687 313 : && shdr_info[symtabidx].debug_data != NULL);
1688 : }
1689 :
1690 : case SHT_REL:
1691 : case SHT_RELA:
1692 295 : if (no_symtab_updates ())
1693 : break;
1694 :
1695 334 : Elf_Data *d = elf_getdata (shdr_info[cnt].idx == 0
1696 : ? elf_getscn (debugelf, cnt)
1697 167 : : elf_getscn (newelf,
1698 : shdr_info[cnt].idx),
1699 : NULL);
1700 167 : elf_assert (d != NULL && d->d_buf != NULL
1701 : && shdr_info[cnt].shdr.sh_entsize != 0);
1702 167 : size_t nrels = (shdr_info[cnt].shdr.sh_size
1703 : / shdr_info[cnt].shdr.sh_entsize);
1704 :
1705 167 : size_t symsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1706 334 : const Elf32_Word symidxn = (shdr_info[symtabidx].data->d_size
1707 167 : / symsize);
1708 167 : if (shdr_info[cnt].shdr.sh_type == SHT_REL)
1709 2411 : for (size_t relidx = 0; relidx < nrels; ++relidx)
1710 : {
1711 : GElf_Rel rel_mem;
1712 2411 : if (gelf_getrel (d, relidx, &rel_mem) == NULL)
1713 0 : INTERNAL_ERROR (fname);
1714 :
1715 2411 : size_t symidx = GELF_R_SYM (rel_mem.r_info);
1716 2411 : elf_assert (symidx < symidxn);
1717 2411 : if (newsymidx[symidx] != symidx)
1718 : {
1719 : rel_mem.r_info
1720 2206 : = GELF_R_INFO (newsymidx[symidx],
1721 : GELF_R_TYPE (rel_mem.r_info));
1722 :
1723 2206 : if (gelf_update_rel (d, relidx, &rel_mem) == 0)
1724 0 : INTERNAL_ERROR (fname);
1725 : }
1726 : }
1727 : else
1728 11082 : for (size_t relidx = 0; relidx < nrels; ++relidx)
1729 : {
1730 : GElf_Rela rel_mem;
1731 11082 : if (gelf_getrela (d, relidx, &rel_mem) == NULL)
1732 0 : INTERNAL_ERROR (fname);
1733 :
1734 11082 : size_t symidx = GELF_R_SYM (rel_mem.r_info);
1735 11082 : elf_assert (symidx < symidxn);
1736 11082 : if (newsymidx[symidx] != symidx)
1737 : {
1738 : rel_mem.r_info
1739 3632 : = GELF_R_INFO (newsymidx[symidx],
1740 : GELF_R_TYPE (rel_mem.r_info));
1741 :
1742 3632 : if (gelf_update_rela (d, relidx, &rel_mem) == 0)
1743 0 : INTERNAL_ERROR (fname);
1744 : }
1745 : }
1746 : break;
1747 :
1748 : case SHT_HASH:
1749 6 : if (no_symtab_updates ())
1750 : break;
1751 :
1752 : /* We have to recompute the hash table. */
1753 :
1754 6 : elf_assert (shdr_info[cnt].idx > 0);
1755 :
1756 : /* The hash section in the new file. */
1757 6 : scn = elf_getscn (newelf, shdr_info[cnt].idx);
1758 :
1759 : /* The symbol table data. */
1760 6 : Elf_Data *symd = elf_getdata (elf_getscn (newelf,
1761 6 : shdr_info[symtabidx].idx),
1762 : NULL);
1763 6 : elf_assert (symd != NULL && symd->d_buf != NULL);
1764 :
1765 : /* The hash table data. */
1766 6 : Elf_Data *hashd = elf_getdata (scn, NULL);
1767 6 : elf_assert (hashd != NULL && hashd->d_buf != NULL);
1768 :
1769 6 : if (shdr_info[cnt].shdr.sh_entsize == sizeof (Elf32_Word))
1770 : {
1771 : /* Sane arches first. */
1772 6 : elf_assert (hashd->d_size >= 2 * sizeof (Elf32_Word));
1773 6 : Elf32_Word *bucket = (Elf32_Word *) hashd->d_buf;
1774 :
1775 6 : size_t strshndx = shdr_info[symtabidx].old_sh_link;
1776 6 : size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1777 :
1778 6 : Elf32_Word nchain = bucket[1];
1779 6 : Elf32_Word nbucket = bucket[0];
1780 12 : uint64_t used_buf = ((2ULL + nchain + nbucket)
1781 6 : * sizeof (Elf32_Word));
1782 6 : elf_assert (used_buf <= hashd->d_size);
1783 :
1784 : /* Adjust the nchain value. The symbol table size
1785 : changed. We keep the same size for the bucket array. */
1786 6 : bucket[1] = symd->d_size / elsize;
1787 6 : bucket += 2;
1788 6 : Elf32_Word *chain = bucket + nbucket;
1789 :
1790 : /* New size of the section. */
1791 12 : size_t n_size = ((2 + symd->d_size / elsize + nbucket)
1792 6 : * sizeof (Elf32_Word));
1793 6 : elf_assert (n_size <= hashd->d_size);
1794 6 : hashd->d_size = n_size;
1795 6 : update_section_size (hashd);
1796 :
1797 : /* Clear the arrays. */
1798 12 : memset (bucket, '\0',
1799 6 : (symd->d_size / elsize + nbucket)
1800 : * sizeof (Elf32_Word));
1801 :
1802 84 : for (size_t inner = shdr_info[symtabidx].shdr.sh_info;
1803 72 : inner < symd->d_size / elsize; ++inner)
1804 : {
1805 : GElf_Sym sym_mem;
1806 72 : GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
1807 72 : elf_assert (sym != NULL);
1808 :
1809 72 : const char *name = elf_strptr (elf, strshndx,
1810 72 : sym->st_name);
1811 72 : elf_assert (name != NULL && nbucket != 0);
1812 72 : size_t hidx = elf_hash (name) % nbucket;
1813 :
1814 72 : if (bucket[hidx] == 0)
1815 60 : bucket[hidx] = inner;
1816 : else
1817 : {
1818 12 : hidx = bucket[hidx];
1819 :
1820 24 : while (chain[hidx] != 0 && chain[hidx] < nchain)
1821 0 : hidx = chain[hidx];
1822 :
1823 12 : chain[hidx] = inner;
1824 : }
1825 : }
1826 : }
1827 : else
1828 0 : {
1829 : /* Alpha and S390 64-bit use 64-bit SHT_HASH entries. */
1830 0 : elf_assert (shdr_info[cnt].shdr.sh_entsize
1831 : == sizeof (Elf64_Xword));
1832 :
1833 0 : Elf64_Xword *bucket = (Elf64_Xword *) hashd->d_buf;
1834 :
1835 0 : size_t strshndx = shdr_info[symtabidx].old_sh_link;
1836 0 : size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1837 :
1838 0 : elf_assert (symd->d_size >= 2 * sizeof (Elf64_Xword));
1839 0 : Elf64_Xword nbucket = bucket[0];
1840 0 : Elf64_Xword nchain = bucket[1];
1841 0 : uint64_t maxwords = hashd->d_size / sizeof (Elf64_Xword);
1842 0 : elf_assert (maxwords >= 2
1843 : && maxwords - 2 >= nbucket
1844 : && maxwords - 2 - nbucket >= nchain);
1845 :
1846 : /* Adjust the nchain value. The symbol table size
1847 : changed. We keep the same size for the bucket array. */
1848 0 : bucket[1] = symd->d_size / elsize;
1849 0 : bucket += 2;
1850 0 : Elf64_Xword *chain = bucket + nbucket;
1851 :
1852 : /* New size of the section. */
1853 0 : size_t n_size = ((2 + symd->d_size / elsize + nbucket)
1854 0 : * sizeof (Elf64_Xword));
1855 0 : elf_assert (n_size <= hashd->d_size);
1856 0 : hashd->d_size = n_size;
1857 0 : update_section_size (hashd);
1858 :
1859 : /* Clear the arrays. */
1860 0 : memset (bucket, '\0',
1861 0 : (symd->d_size / elsize + nbucket)
1862 : * sizeof (Elf64_Xword));
1863 :
1864 0 : for (size_t inner = shdr_info[symtabidx].shdr.sh_info;
1865 0 : inner < symd->d_size / elsize; ++inner)
1866 : {
1867 : GElf_Sym sym_mem;
1868 0 : GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
1869 0 : elf_assert (sym != NULL);
1870 :
1871 0 : const char *name = elf_strptr (elf, strshndx,
1872 0 : sym->st_name);
1873 0 : elf_assert (name != NULL && nbucket != 0);
1874 0 : size_t hidx = elf_hash (name) % nbucket;
1875 :
1876 0 : if (bucket[hidx] == 0)
1877 0 : bucket[hidx] = inner;
1878 : else
1879 : {
1880 : hidx = bucket[hidx];
1881 :
1882 0 : while (chain[hidx] != 0 && chain[hidx] < nchain)
1883 : hidx = chain[hidx];
1884 :
1885 0 : chain[hidx] = inner;
1886 : }
1887 : }
1888 : }
1889 : break;
1890 :
1891 : case SHT_GNU_versym:
1892 : /* If the symbol table changed we have to adjust the entries. */
1893 6 : if (no_symtab_updates ())
1894 : break;
1895 :
1896 6 : elf_assert (shdr_info[cnt].idx > 0);
1897 :
1898 : /* The symbol version section in the new file. */
1899 6 : scn = elf_getscn (newelf, shdr_info[cnt].idx);
1900 :
1901 : /* The symbol table data. */
1902 6 : symd = elf_getdata (elf_getscn (newelf, shdr_info[symtabidx].idx),
1903 : NULL);
1904 6 : elf_assert (symd != NULL && symd->d_buf != NULL);
1905 6 : size_t symz = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1906 6 : const Elf32_Word syms = (shdr_info[symtabidx].data->d_size / symz);
1907 :
1908 : /* The version symbol data. */
1909 6 : Elf_Data *verd = elf_getdata (scn, NULL);
1910 6 : elf_assert (verd != NULL && verd->d_buf != NULL);
1911 :
1912 : /* The symbol version array. */
1913 6 : GElf_Half *verstab = (GElf_Half *) verd->d_buf;
1914 :
1915 : /* Walk through the list and */
1916 6 : size_t elsize = gelf_fsize (elf, verd->d_type, 1, EV_CURRENT);
1917 6 : Elf32_Word vers = verd->d_size / elsize;
1918 258 : for (size_t inner = 1; inner < vers && inner < syms; ++inner)
1919 252 : if (newsymidx[inner] != 0 && newsymidx[inner] < vers)
1920 : /* Overwriting the same array works since the
1921 : reordering can only move entries to lower indices
1922 : in the array. */
1923 204 : verstab[newsymidx[inner]] = verstab[inner];
1924 :
1925 : /* New size of the section. */
1926 6 : verd->d_size = gelf_fsize (newelf, verd->d_type,
1927 6 : symd->d_size
1928 6 : / gelf_fsize (elf, symd->d_type, 1,
1929 : EV_CURRENT),
1930 : EV_CURRENT);
1931 6 : update_section_size (verd);
1932 6 : break;
1933 :
1934 : case SHT_GROUP:
1935 6 : if (no_symtab_updates ())
1936 : break;
1937 :
1938 : /* Yes, the symbol table changed.
1939 : Update the section header of the section group. */
1940 5 : scn = elf_getscn (newelf, shdr_info[cnt].idx);
1941 : GElf_Shdr shdr_mem;
1942 5 : GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
1943 5 : elf_assert (shdr != NULL);
1944 :
1945 5 : size_t symsz = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
1946 10 : const Elf32_Word symn = (shdr_info[symtabidx].data->d_size
1947 5 : / symsz);
1948 5 : elf_assert (shdr->sh_info < symn);
1949 5 : shdr->sh_info = newsymidx[shdr->sh_info];
1950 :
1951 5 : (void) gelf_update_shdr (scn, shdr);
1952 5 : break;
1953 : }
1954 : }
1955 :
1956 : /* Remove any relocations between debug sections in ET_REL
1957 : for the debug file when requested. These relocations are always
1958 : zero based between the unallocated sections. */
1959 82 : if (debug_fname != NULL && removing_sections
1960 46 : && reloc_debug && ehdr->e_type == ET_REL)
1961 : {
1962 10 : scn = NULL;
1963 10 : cnt = 0;
1964 360 : while ((scn = elf_nextscn (debugelf, scn)) != NULL)
1965 : {
1966 340 : cnt++;
1967 : /* We need the actual section and header from the debugelf
1968 : not just the cached original in shdr_info because we
1969 : might want to change the size. */
1970 : GElf_Shdr shdr_mem;
1971 340 : GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
1972 340 : if (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA)
1973 : {
1974 : /* Make sure that this relocation section points to a
1975 : section to relocate with contents, that isn't
1976 : allocated and that is a debug section. */
1977 49 : Elf_Scn *tscn = elf_getscn (debugelf, shdr->sh_info);
1978 : GElf_Shdr tshdr_mem;
1979 49 : GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem);
1980 49 : if (tshdr->sh_type == SHT_NOBITS
1981 49 : || tshdr->sh_size == 0
1982 49 : || (tshdr->sh_flags & SHF_ALLOC) != 0)
1983 0 : continue;
1984 :
1985 49 : const char *tname = elf_strptr (debugelf, shstrndx,
1986 49 : tshdr->sh_name);
1987 49 : if (! tname || ! ebl_debugscn_p (ebl, tname))
1988 0 : continue;
1989 :
1990 : /* OK, lets relocate all trivial cross debug section
1991 : relocations. */
1992 49 : Elf_Data *reldata = elf_getdata (scn, NULL);
1993 49 : if (reldata == NULL || reldata->d_buf == NULL)
1994 0 : INTERNAL_ERROR (fname);
1995 :
1996 : /* Make sure we adjust the uncompressed debug data
1997 : (and recompress if necessary at the end). */
1998 : GElf_Chdr tchdr;
1999 49 : int tcompress_type = 0;
2000 49 : if (gelf_getchdr (tscn, &tchdr) != NULL)
2001 : {
2002 5 : tcompress_type = tchdr.ch_type;
2003 5 : if (elf_compress (tscn, 0, 0) != 1)
2004 0 : INTERNAL_ERROR (fname);
2005 : }
2006 :
2007 49 : Elf_Data *tdata = elf_getdata (tscn, NULL);
2008 49 : if (tdata == NULL || tdata->d_buf == NULL
2009 49 : || tdata->d_type != ELF_T_BYTE)
2010 0 : INTERNAL_ERROR (fname);
2011 :
2012 : /* Pick up the symbol table and shndx table to
2013 : resolve relocation symbol indexes. */
2014 49 : Elf64_Word symt = shdr->sh_link;
2015 : Elf_Data *symdata, *xndxdata;
2016 49 : elf_assert (symt < shnum + 2);
2017 49 : elf_assert (shdr_info[symt].symtab_idx < shnum + 2);
2018 98 : symdata = (shdr_info[symt].debug_data
2019 49 : ?: shdr_info[symt].data);
2020 98 : xndxdata = (shdr_info[shdr_info[symt].symtab_idx].debug_data
2021 49 : ?: shdr_info[shdr_info[symt].symtab_idx].data);
2022 :
2023 : /* Apply one relocation. Returns true when trivial
2024 : relocation actually done. */
2025 34747 : bool relocate (GElf_Addr offset, const GElf_Sxword addend,
2026 : bool is_rela, int rtype, int symndx)
2027 : {
2028 : /* R_*_NONE relocs can always just be removed. */
2029 34747 : if (rtype == 0)
2030 : return true;
2031 :
2032 : /* We only do simple absolute relocations. */
2033 34747 : Elf_Type type = ebl_reloc_simple_type (ebl, rtype);
2034 34747 : if (type == ELF_T_NUM)
2035 : return false;
2036 :
2037 : /* These are the types we can relocate. */
2038 : #define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \
2039 : DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \
2040 : DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword)
2041 :
2042 : /* And only for relocations against other debug sections. */
2043 : GElf_Sym sym_mem;
2044 : Elf32_Word xndx;
2045 34709 : GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
2046 : symndx, &sym_mem,
2047 : &xndx);
2048 69418 : Elf32_Word sec = (sym->st_shndx == SHN_XINDEX
2049 34709 : ? xndx : sym->st_shndx);
2050 34709 : if (sec >= shnum + 2)
2051 0 : INTERNAL_ERROR (fname);
2052 :
2053 34709 : if (ebl_debugscn_p (ebl, shdr_info[sec].name))
2054 : {
2055 : size_t size;
2056 :
2057 : #define DO_TYPE(NAME, Name) GElf_##Name Name;
2058 : union { TYPES; } tmpbuf;
2059 : #undef DO_TYPE
2060 :
2061 24096 : switch (type)
2062 : {
2063 : #define DO_TYPE(NAME, Name) \
2064 : case ELF_T_##NAME: \
2065 : size = sizeof (GElf_##Name); \
2066 : tmpbuf.Name = 0; \
2067 : break;
2068 0 : TYPES;
2069 : #undef DO_TYPE
2070 : default:
2071 : return false;
2072 : }
2073 :
2074 24096 : if (offset > tdata->d_size
2075 24096 : || tdata->d_size - offset < size)
2076 : {
2077 0 : cleanup_debug ();
2078 0 : error (EXIT_FAILURE, 0, gettext ("bad relocation"));
2079 : }
2080 :
2081 : /* When the symbol value is zero then for SHT_REL
2082 : sections this is all that needs to be checked.
2083 : The addend is contained in the original data at
2084 : the offset already. So if the (section) symbol
2085 : address is zero and the given addend is zero
2086 : just remove the relocation, it isn't needed
2087 : anymore. */
2088 24096 : if (addend == 0 && sym->st_value == 0)
2089 : return true;
2090 :
2091 20848 : Elf_Data tmpdata =
2092 : {
2093 : .d_type = type,
2094 : .d_buf = &tmpbuf,
2095 : .d_size = size,
2096 : .d_version = EV_CURRENT,
2097 : };
2098 41696 : Elf_Data rdata =
2099 : {
2100 : .d_type = type,
2101 20848 : .d_buf = tdata->d_buf + offset,
2102 : .d_size = size,
2103 : .d_version = EV_CURRENT,
2104 : };
2105 :
2106 20848 : GElf_Addr value = sym->st_value;
2107 20848 : if (is_rela)
2108 : {
2109 : /* For SHT_RELA sections we just take the
2110 : given addend and add it to the value. */
2111 20848 : value += addend;
2112 : }
2113 : else
2114 : {
2115 : /* For SHT_REL sections we have to peek at
2116 : what is already in the section at the given
2117 : offset to get the addend. */
2118 0 : Elf_Data *d = gelf_xlatetom (debugelf, &tmpdata,
2119 : &rdata,
2120 0 : ehdr->e_ident[EI_DATA]);
2121 0 : if (d == NULL)
2122 0 : INTERNAL_ERROR (fname);
2123 0 : assert (d == &tmpdata);
2124 : }
2125 :
2126 20848 : switch (type)
2127 : {
2128 : #define DO_TYPE(NAME, Name) \
2129 : case ELF_T_##NAME: \
2130 : tmpbuf.Name += (GElf_##Name) value; \
2131 : break;
2132 0 : TYPES;
2133 : #undef DO_TYPE
2134 0 : default:
2135 0 : abort ();
2136 : }
2137 :
2138 : /* Now finally put in the new value. */
2139 20848 : Elf_Data *s = gelf_xlatetof (debugelf, &rdata,
2140 : &tmpdata,
2141 20848 : ehdr->e_ident[EI_DATA]);
2142 20848 : if (s == NULL)
2143 0 : INTERNAL_ERROR (fname);
2144 20848 : assert (s == &rdata);
2145 :
2146 : return true;
2147 : }
2148 : return false;
2149 : }
2150 :
2151 49 : if (shdr->sh_entsize == 0)
2152 0 : INTERNAL_ERROR (fname);
2153 :
2154 49 : size_t nrels = shdr->sh_size / shdr->sh_entsize;
2155 49 : size_t next = 0;
2156 49 : if (shdr->sh_type == SHT_REL)
2157 3212 : for (size_t relidx = 0; relidx < nrels; ++relidx)
2158 : {
2159 : GElf_Rel rel_mem;
2160 3212 : GElf_Rel *r = gelf_getrel (reldata, relidx, &rel_mem);
2161 3212 : if (! relocate (r->r_offset, 0, false,
2162 : GELF_R_TYPE (r->r_info),
2163 3212 : GELF_R_SYM (r->r_info)))
2164 : {
2165 18 : if (relidx != next)
2166 16 : gelf_update_rel (reldata, next, r);
2167 18 : ++next;
2168 : }
2169 : }
2170 : else
2171 31535 : for (size_t relidx = 0; relidx < nrels; ++relidx)
2172 : {
2173 : GElf_Rela rela_mem;
2174 31535 : GElf_Rela *r = gelf_getrela (reldata, relidx, &rela_mem);
2175 31535 : if (! relocate (r->r_offset, r->r_addend, true,
2176 : GELF_R_TYPE (r->r_info),
2177 31535 : GELF_R_SYM (r->r_info)))
2178 : {
2179 10633 : if (relidx != next)
2180 5712 : gelf_update_rela (reldata, next, r);
2181 10633 : ++next;
2182 : }
2183 : }
2184 :
2185 49 : nrels = next;
2186 49 : shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
2187 49 : gelf_update_shdr (scn, shdr);
2188 :
2189 49 : if (tcompress_type != 0)
2190 5 : if (elf_compress (tscn, tcompress_type, ELF_CHF_FORCE) != 1)
2191 0 : INTERNAL_ERROR (fname);
2192 : }
2193 : }
2194 : }
2195 :
2196 : /* Now that we have done all adjustments to the data,
2197 : we can actually write out the debug file. */
2198 82 : if (debug_fname != NULL && removing_sections)
2199 : {
2200 : /* Finally write the file. */
2201 46 : if (unlikely (elf_update (debugelf, ELF_C_WRITE) == -1))
2202 : {
2203 0 : error (0, 0, gettext ("while writing '%s': %s"),
2204 : tmp_debug_fname, elf_errmsg (-1));
2205 0 : result = 1;
2206 0 : goto fail_close;
2207 : }
2208 :
2209 : /* Create the real output file. First rename, then change the
2210 : mode. */
2211 46 : if (rename (tmp_debug_fname, debug_fname) != 0
2212 46 : || fchmod (debug_fd, mode) != 0)
2213 : {
2214 0 : error (0, errno, gettext ("while creating '%s'"), debug_fname);
2215 0 : result = 1;
2216 0 : goto fail_close;
2217 : }
2218 :
2219 : /* The temporary file does not exist anymore. */
2220 46 : free (tmp_debug_fname);
2221 46 : tmp_debug_fname = NULL;
2222 :
2223 46 : if (!remove_shdrs)
2224 : {
2225 : uint32_t debug_crc;
2226 46 : Elf_Data debug_crc_data =
2227 : {
2228 : .d_type = ELF_T_WORD,
2229 : .d_buf = &debug_crc,
2230 : .d_size = sizeof (debug_crc),
2231 : .d_version = EV_CURRENT
2232 : };
2233 :
2234 : /* Compute the checksum which we will add to the executable. */
2235 46 : if (crc32_file (debug_fd, &debug_crc) != 0)
2236 : {
2237 0 : error (0, errno, gettext ("\
2238 : while computing checksum for debug information"));
2239 0 : unlink (debug_fname);
2240 0 : result = 1;
2241 0 : goto fail_close;
2242 : }
2243 :
2244 : /* Store it in the debuglink section data. */
2245 46 : if (unlikely (gelf_xlatetof (newelf, &debuglink_crc_data,
2246 : &debug_crc_data, ehdr->e_ident[EI_DATA])
2247 : != &debuglink_crc_data))
2248 0 : INTERNAL_ERROR (fname);
2249 : }
2250 : }
2251 :
2252 : /* Finally finish the ELF header. Fill in the fields not handled by
2253 : libelf from the old file. */
2254 82 : newehdr = gelf_getehdr (newelf, &newehdr_mem);
2255 82 : if (newehdr == NULL)
2256 0 : INTERNAL_ERROR (fname);
2257 :
2258 164 : memcpy (newehdr->e_ident, ehdr->e_ident, EI_NIDENT);
2259 82 : newehdr->e_type = ehdr->e_type;
2260 82 : newehdr->e_machine = ehdr->e_machine;
2261 82 : newehdr->e_version = ehdr->e_version;
2262 82 : newehdr->e_entry = ehdr->e_entry;
2263 82 : newehdr->e_flags = ehdr->e_flags;
2264 82 : newehdr->e_phoff = ehdr->e_phoff;
2265 :
2266 : /* We need to position the section header table. */
2267 82 : const size_t offsize = gelf_fsize (elf, ELF_T_OFF, 1, EV_CURRENT);
2268 164 : newehdr->e_shoff = ((shdr_info[shdridx].shdr.sh_offset
2269 82 : + shdr_info[shdridx].shdr.sh_size + offsize - 1)
2270 82 : & ~((GElf_Off) (offsize - 1)));
2271 82 : newehdr->e_shentsize = gelf_fsize (elf, ELF_T_SHDR, 1, EV_CURRENT);
2272 :
2273 : /* The new section header string table index. */
2274 82 : if (likely (idx < SHN_HIRESERVE) && likely (idx != SHN_XINDEX))
2275 82 : newehdr->e_shstrndx = idx;
2276 : else
2277 : {
2278 : /* The index does not fit in the ELF header field. */
2279 0 : shdr_info[0].scn = elf_getscn (elf, 0);
2280 :
2281 0 : if (gelf_getshdr (shdr_info[0].scn, &shdr_info[0].shdr) == NULL)
2282 0 : INTERNAL_ERROR (fname);
2283 :
2284 0 : shdr_info[0].shdr.sh_link = idx;
2285 0 : (void) gelf_update_shdr (shdr_info[0].scn, &shdr_info[0].shdr);
2286 :
2287 0 : newehdr->e_shstrndx = SHN_XINDEX;
2288 : }
2289 :
2290 82 : if (gelf_update_ehdr (newelf, newehdr) == 0)
2291 : {
2292 0 : error (0, 0, gettext ("%s: error while creating ELF header: %s"),
2293 0 : output_fname ?: fname, elf_errmsg (-1));
2294 0 : cleanup_debug ();
2295 0 : return 1;
2296 : }
2297 :
2298 : /* We have everything from the old file. */
2299 82 : if (elf_cntl (elf, ELF_C_FDDONE) != 0)
2300 : {
2301 0 : error (0, 0, gettext ("%s: error while reading the file: %s"),
2302 : fname, elf_errmsg (-1));
2303 0 : cleanup_debug ();
2304 0 : return 1;
2305 : }
2306 :
2307 : /* The ELF library better follows our layout when this is not a
2308 : relocatable object file. */
2309 82 : elf_flagelf (newelf, ELF_C_SET,
2310 82 : (ehdr->e_type != ET_REL ? ELF_F_LAYOUT : 0)
2311 82 : | (permissive ? ELF_F_PERMISSIVE : 0));
2312 :
2313 : /* Finally write the file. */
2314 82 : if (elf_update (newelf, ELF_C_WRITE) == -1)
2315 : {
2316 0 : error (0, 0, gettext ("while writing '%s': %s"),
2317 0 : output_fname ?: fname, elf_errmsg (-1));
2318 0 : result = 1;
2319 : }
2320 :
2321 82 : if (remove_shdrs)
2322 : {
2323 : /* libelf can't cope without the section headers being properly intact.
2324 : So we just let it write them normally, and then we nuke them later. */
2325 :
2326 0 : if (newehdr->e_ident[EI_CLASS] == ELFCLASS32)
2327 : {
2328 : assert (offsetof (Elf32_Ehdr, e_shentsize) + sizeof (Elf32_Half)
2329 : == offsetof (Elf32_Ehdr, e_shnum));
2330 : assert (offsetof (Elf32_Ehdr, e_shnum) + sizeof (Elf32_Half)
2331 : == offsetof (Elf32_Ehdr, e_shstrndx));
2332 0 : const Elf32_Off zero_off = 0;
2333 0 : const Elf32_Half zero[3] = { 0, 0, SHN_UNDEF };
2334 0 : if (pwrite_retry (fd, &zero_off, sizeof zero_off,
2335 : offsetof (Elf32_Ehdr, e_shoff)) != sizeof zero_off
2336 0 : || (pwrite_retry (fd, zero, sizeof zero,
2337 : offsetof (Elf32_Ehdr, e_shentsize))
2338 : != sizeof zero)
2339 0 : || ftruncate (fd, shdr_info[shdridx].shdr.sh_offset) < 0)
2340 : {
2341 0 : error (0, errno, gettext ("while writing '%s'"),
2342 0 : output_fname ?: fname);
2343 0 : result = 1;
2344 : }
2345 : }
2346 : else
2347 : {
2348 : assert (offsetof (Elf64_Ehdr, e_shentsize) + sizeof (Elf64_Half)
2349 : == offsetof (Elf64_Ehdr, e_shnum));
2350 : assert (offsetof (Elf64_Ehdr, e_shnum) + sizeof (Elf64_Half)
2351 : == offsetof (Elf64_Ehdr, e_shstrndx));
2352 0 : const Elf64_Off zero_off = 0;
2353 0 : const Elf64_Half zero[3] = { 0, 0, SHN_UNDEF };
2354 0 : if (pwrite_retry (fd, &zero_off, sizeof zero_off,
2355 : offsetof (Elf64_Ehdr, e_shoff)) != sizeof zero_off
2356 0 : || (pwrite_retry (fd, zero, sizeof zero,
2357 : offsetof (Elf64_Ehdr, e_shentsize))
2358 : != sizeof zero)
2359 0 : || ftruncate (fd, shdr_info[shdridx].shdr.sh_offset) < 0)
2360 : {
2361 0 : error (0, errno, gettext ("while writing '%s'"),
2362 0 : output_fname ?: fname);
2363 0 : result = 1;
2364 : }
2365 : }
2366 : }
2367 :
2368 169 : fail_close:
2369 85 : if (shdr_info != NULL)
2370 : {
2371 : /* For some sections we might have created an table to map symbol
2372 : table indices. Or we might kept (original) data around to put
2373 : into the .debug file. */
2374 199522 : for (cnt = 1; cnt <= shdridx; ++cnt)
2375 : {
2376 199437 : free (shdr_info[cnt].newsymidx);
2377 199437 : if (shdr_info[cnt].debug_data != NULL)
2378 62 : free (shdr_info[cnt].debug_data->d_buf);
2379 : }
2380 :
2381 : /* Free data we allocated for the .gnu_debuglink section. */
2382 85 : free (debuglink_buf);
2383 :
2384 : /* Free the memory. */
2385 85 : if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC)
2386 3 : free (shdr_info);
2387 : }
2388 :
2389 : /* Free other resources. */
2390 85 : if (shstrtab_data != NULL)
2391 83 : free (shstrtab_data->d_buf);
2392 85 : if (shst != NULL)
2393 85 : dwelf_strtab_free (shst);
2394 :
2395 : /* That was it. Close the descriptors. */
2396 85 : if (elf_end (newelf) != 0)
2397 : {
2398 0 : error (0, 0, gettext ("error while finishing '%s': %s"),
2399 0 : output_fname ?: fname, elf_errmsg (-1));
2400 0 : result = 1;
2401 : }
2402 :
2403 134 : if (debugelf != NULL && elf_end (debugelf) != 0)
2404 : {
2405 0 : error (0, 0, gettext ("error while finishing '%s': %s"), debug_fname,
2406 : elf_errmsg (-1));
2407 0 : result = 1;
2408 : }
2409 :
2410 170 : fail:
2411 : /* Close the EBL backend. */
2412 85 : if (ebl != NULL)
2413 36 : ebl_closebackend (ebl);
2414 :
2415 85 : cleanup_debug ();
2416 :
2417 : /* If requested, preserve the timestamp. */
2418 85 : if (tvp != NULL)
2419 : {
2420 0 : if (futimens (fd, tvp) != 0)
2421 : {
2422 0 : error (0, errno, gettext ("\
2423 : cannot set access and modification date of '%s'"),
2424 0 : output_fname ?: fname);
2425 0 : result = 1;
2426 : }
2427 : }
2428 :
2429 : /* Close the file descriptor if we created a new file. */
2430 85 : if (output_fname != NULL)
2431 : {
2432 69 : close (fd);
2433 69 : if (result != 0)
2434 0 : unlink (output_fname);
2435 : }
2436 :
2437 : return result;
2438 : }
2439 :
2440 : static void
2441 85 : cleanup_debug (void)
2442 : {
2443 85 : if (debug_fd >= 0)
2444 : {
2445 49 : if (tmp_debug_fname != NULL)
2446 : {
2447 3 : unlink (tmp_debug_fname);
2448 3 : free (tmp_debug_fname);
2449 3 : tmp_debug_fname = NULL;
2450 : }
2451 49 : close (debug_fd);
2452 49 : debug_fd = -1;
2453 : }
2454 85 : }
2455 :
2456 : static int
2457 : handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
2458 : struct timespec tvp[2])
2459 : {
2460 : size_t prefix_len = prefix == NULL ? 0 : strlen (prefix);
2461 : size_t fname_len = strlen (fname) + 1;
2462 : char new_prefix[prefix_len + 1 + fname_len];
2463 : char *cp = new_prefix;
2464 :
2465 : /* Create the full name of the file. */
2466 : if (prefix != NULL)
2467 : {
2468 : cp = mempcpy (cp, prefix, prefix_len);
2469 : *cp++ = ':';
2470 : }
2471 : memcpy (cp, fname, fname_len);
2472 :
2473 :
2474 : /* Process all the files contained in the archive. */
2475 : Elf *subelf;
2476 : Elf_Cmd cmd = ELF_C_RDWR;
2477 : int result = 0;
2478 : while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
2479 : {
2480 : /* The the header for this element. */
2481 : Elf_Arhdr *arhdr = elf_getarhdr (subelf);
2482 :
2483 : if (elf_kind (subelf) == ELF_K_ELF)
2484 : result |= handle_elf (fd, subelf, new_prefix, arhdr->ar_name, 0, NULL);
2485 : else if (elf_kind (subelf) == ELF_K_AR)
2486 : result |= handle_ar (fd, subelf, new_prefix, arhdr->ar_name, NULL);
2487 :
2488 : /* Get next archive element. */
2489 : cmd = elf_next (subelf);
2490 : if (unlikely (elf_end (subelf) != 0))
2491 : INTERNAL_ERROR (fname);
2492 : }
2493 :
2494 : if (tvp != NULL)
2495 : {
2496 : if (unlikely (futimens (fd, tvp) != 0))
2497 : {
2498 : error (0, errno, gettext ("\
2499 : cannot set access and modification date of '%s'"), fname);
2500 : result = 1;
2501 : }
2502 : }
2503 :
2504 : if (unlikely (close (fd) != 0))
2505 : error (EXIT_FAILURE, errno, gettext ("while closing '%s'"), fname);
2506 :
2507 : return result;
2508 : }
2509 :
2510 :
2511 : #include "debugpred.h"
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