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elf: Compute correct array size in _dl_init_paths [BZ #22606]
[thirdparty/glibc.git] / elf / dl-load.c
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2017 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <elf.h>
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <libintl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <ldsodefs.h>
28 #include <bits/wordsize.h>
29 #include <sys/mman.h>
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include "dynamic-link.h"
34 #include <abi-tag.h>
35 #include <stackinfo.h>
36 #include <caller.h>
37 #include <sysdep.h>
38 #include <stap-probe.h>
39 #include <libc-pointer-arith.h>
40 #include <array_length.h>
41
42 #include <dl-dst.h>
43 #include <dl-load.h>
44 #include <dl-map-segments.h>
45 #include <dl-unmap-segments.h>
46 #include <dl-machine-reject-phdr.h>
47 #include <dl-sysdep-open.h>
48
49
50 #include <endian.h>
51 #if BYTE_ORDER == BIG_ENDIAN
52 # define byteorder ELFDATA2MSB
53 #elif BYTE_ORDER == LITTLE_ENDIAN
54 # define byteorder ELFDATA2LSB
55 #else
56 # error "Unknown BYTE_ORDER " BYTE_ORDER
57 # define byteorder ELFDATANONE
58 #endif
59
60 #define STRING(x) __STRING (x)
61
62
63 int __stack_prot attribute_hidden attribute_relro
64 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
65 = PROT_GROWSDOWN;
66 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
67 = PROT_GROWSUP;
68 #else
69 = 0;
70 #endif
71
72
73 /* Type for the buffer we put the ELF header and hopefully the program
74 header. This buffer does not really have to be too large. In most
75 cases the program header follows the ELF header directly. If this
76 is not the case all bets are off and we can make the header
77 arbitrarily large and still won't get it read. This means the only
78 question is how large are the ELF and program header combined. The
79 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
80 bytes long. Each program header entry is again 32 and 56 bytes
81 long respectively. I.e., even with a file which has 10 program
82 header entries we only have to read 372B/624B respectively. Add to
83 this a bit of margin for program notes and reading 512B and 832B
84 for 32-bit and 64-bit files respecitvely is enough. If this
85 heuristic should really fail for some file the code in
86 `_dl_map_object_from_fd' knows how to recover. */
87 struct filebuf
88 {
89 ssize_t len;
90 #if __WORDSIZE == 32
91 # define FILEBUF_SIZE 512
92 #else
93 # define FILEBUF_SIZE 832
94 #endif
95 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
96 };
97
98 /* This is the decomposed LD_LIBRARY_PATH search path. */
99 static struct r_search_path_struct env_path_list attribute_relro;
100
101 /* List of the hardware capabilities we might end up using. */
102 static const struct r_strlenpair *capstr attribute_relro;
103 static size_t ncapstr attribute_relro;
104 static size_t max_capstrlen attribute_relro;
105
106
107 /* Get the generated information about the trusted directories. Use
108 an array of concatenated strings to avoid relocations. See
109 gen-trusted-dirs.awk. */
110 #include "trusted-dirs.h"
111
112 static const char system_dirs[] = SYSTEM_DIRS;
113 static const size_t system_dirs_len[] =
114 {
115 SYSTEM_DIRS_LEN
116 };
117 #define nsystem_dirs_len array_length (system_dirs_len)
118
119 static bool
120 is_trusted_path (const char *path, size_t len)
121 {
122 const char *trun = system_dirs;
123
124 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
125 {
126 if (len == system_dirs_len[idx] && memcmp (trun, path, len) == 0)
127 /* Found it. */
128 return true;
129
130 trun += system_dirs_len[idx] + 1;
131 }
132
133 return false;
134 }
135
136
137 static bool
138 is_trusted_path_normalize (const char *path, size_t len)
139 {
140 if (len == 0)
141 return false;
142
143 if (*path == ':')
144 {
145 ++path;
146 --len;
147 }
148
149 char *npath = (char *) alloca (len + 2);
150 char *wnp = npath;
151 while (*path != '\0')
152 {
153 if (path[0] == '/')
154 {
155 if (path[1] == '.')
156 {
157 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
158 {
159 while (wnp > npath && *--wnp != '/')
160 ;
161 path += 3;
162 continue;
163 }
164 else if (path[2] == '/' || path[2] == '\0')
165 {
166 path += 2;
167 continue;
168 }
169 }
170
171 if (wnp > npath && wnp[-1] == '/')
172 {
173 ++path;
174 continue;
175 }
176 }
177
178 *wnp++ = *path++;
179 }
180
181 if (wnp == npath || wnp[-1] != '/')
182 *wnp++ = '/';
183
184 const char *trun = system_dirs;
185
186 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
187 {
188 if (wnp - npath >= system_dirs_len[idx]
189 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
190 /* Found it. */
191 return true;
192
193 trun += system_dirs_len[idx] + 1;
194 }
195
196 return false;
197 }
198
199
200 static size_t
201 is_dst (const char *start, const char *name, const char *str,
202 int is_path, int secure)
203 {
204 size_t len;
205 bool is_curly = false;
206
207 if (name[0] == '{')
208 {
209 is_curly = true;
210 ++name;
211 }
212
213 len = 0;
214 while (name[len] == str[len] && name[len] != '\0')
215 ++len;
216
217 if (is_curly)
218 {
219 if (name[len] != '}')
220 return 0;
221
222 /* Point again at the beginning of the name. */
223 --name;
224 /* Skip over closing curly brace and adjust for the --name. */
225 len += 2;
226 }
227 else if (name[len] != '\0' && name[len] != '/'
228 && (!is_path || name[len] != ':'))
229 return 0;
230
231 if (__glibc_unlikely (secure)
232 && ((name[len] != '\0' && name[len] != '/'
233 && (!is_path || name[len] != ':'))
234 || (name != start + 1 && (!is_path || name[-2] != ':'))))
235 return 0;
236
237 return len;
238 }
239
240
241 size_t
242 _dl_dst_count (const char *name, int is_path)
243 {
244 const char *const start = name;
245 size_t cnt = 0;
246
247 do
248 {
249 size_t len;
250
251 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
252 is $ORIGIN alone) and it must always appear first in path. */
253 ++name;
254 if ((len = is_dst (start, name, "ORIGIN", is_path,
255 __libc_enable_secure)) != 0
256 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
257 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
258 ++cnt;
259
260 name = strchr (name + len, '$');
261 }
262 while (name != NULL);
263
264 return cnt;
265 }
266
267
268 char *
269 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
270 int is_path)
271 {
272 const char *const start = name;
273
274 /* Now fill the result path. While copying over the string we keep
275 track of the start of the last path element. When we come across
276 a DST we copy over the value or (if the value is not available)
277 leave the entire path element out. */
278 char *wp = result;
279 char *last_elem = result;
280 bool check_for_trusted = false;
281
282 do
283 {
284 if (__glibc_unlikely (*name == '$'))
285 {
286 const char *repl = NULL;
287 size_t len;
288
289 ++name;
290 if ((len = is_dst (start, name, "ORIGIN", is_path,
291 __libc_enable_secure)) != 0)
292 {
293 repl = l->l_origin;
294 check_for_trusted = (__libc_enable_secure
295 && l->l_type == lt_executable);
296 }
297 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
298 repl = GLRO(dl_platform);
299 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
300 repl = DL_DST_LIB;
301
302 if (repl != NULL && repl != (const char *) -1)
303 {
304 wp = __stpcpy (wp, repl);
305 name += len;
306 }
307 else if (len > 1)
308 {
309 /* We cannot use this path element, the value of the
310 replacement is unknown. */
311 wp = last_elem;
312 name += len;
313 while (*name != '\0' && (!is_path || *name != ':'))
314 ++name;
315 /* Also skip following colon if this is the first rpath
316 element, but keep an empty element at the end. */
317 if (wp == result && is_path && *name == ':' && name[1] != '\0')
318 ++name;
319 }
320 else
321 /* No DST we recognize. */
322 *wp++ = '$';
323 }
324 else
325 {
326 *wp++ = *name++;
327 if (is_path && *name == ':')
328 {
329 /* In SUID/SGID programs, after $ORIGIN expansion the
330 normalized path must be rooted in one of the trusted
331 directories. */
332 if (__glibc_unlikely (check_for_trusted)
333 && !is_trusted_path_normalize (last_elem, wp - last_elem))
334 wp = last_elem;
335 else
336 last_elem = wp;
337
338 check_for_trusted = false;
339 }
340 }
341 }
342 while (*name != '\0');
343
344 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
345 path must be rooted in one of the trusted directories. */
346 if (__glibc_unlikely (check_for_trusted)
347 && !is_trusted_path_normalize (last_elem, wp - last_elem))
348 wp = last_elem;
349
350 *wp = '\0';
351
352 return result;
353 }
354
355
356 /* Return copy of argument with all recognized dynamic string tokens
357 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
358 might not be possible to determine the path from which the object
359 belonging to the map is loaded. In this case the path element
360 containing $ORIGIN is left out. */
361 static char *
362 expand_dynamic_string_token (struct link_map *l, const char *s, int is_path)
363 {
364 /* We make two runs over the string. First we determine how large the
365 resulting string is and then we copy it over. Since this is no
366 frequently executed operation we are looking here not for performance
367 but rather for code size. */
368 size_t cnt;
369 size_t total;
370 char *result;
371
372 /* Determine the number of DST elements. */
373 cnt = DL_DST_COUNT (s, is_path);
374
375 /* If we do not have to replace anything simply copy the string. */
376 if (__glibc_likely (cnt == 0))
377 return __strdup (s);
378
379 /* Determine the length of the substituted string. */
380 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
381
382 /* Allocate the necessary memory. */
383 result = (char *) malloc (total + 1);
384 if (result == NULL)
385 return NULL;
386
387 return _dl_dst_substitute (l, s, result, is_path);
388 }
389
390
391 /* Add `name' to the list of names for a particular shared object.
392 `name' is expected to have been allocated with malloc and will
393 be freed if the shared object already has this name.
394 Returns false if the object already had this name. */
395 static void
396 add_name_to_object (struct link_map *l, const char *name)
397 {
398 struct libname_list *lnp, *lastp;
399 struct libname_list *newname;
400 size_t name_len;
401
402 lastp = NULL;
403 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
404 if (strcmp (name, lnp->name) == 0)
405 return;
406
407 name_len = strlen (name) + 1;
408 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
409 if (newname == NULL)
410 {
411 /* No more memory. */
412 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
413 return;
414 }
415 /* The object should have a libname set from _dl_new_object. */
416 assert (lastp != NULL);
417
418 newname->name = memcpy (newname + 1, name, name_len);
419 newname->next = NULL;
420 newname->dont_free = 0;
421 lastp->next = newname;
422 }
423
424 /* Standard search directories. */
425 static struct r_search_path_struct rtld_search_dirs attribute_relro;
426
427 static size_t max_dirnamelen;
428
429 static struct r_search_path_elem **
430 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
431 int check_trusted, const char *what, const char *where,
432 struct link_map *l)
433 {
434 char *cp;
435 size_t nelems = 0;
436 char *to_free;
437
438 while ((cp = __strsep (&rpath, sep)) != NULL)
439 {
440 struct r_search_path_elem *dirp;
441
442 to_free = cp = expand_dynamic_string_token (l, cp, 1);
443
444 size_t len = strlen (cp);
445
446 /* `strsep' can pass an empty string. This has to be
447 interpreted as `use the current directory'. */
448 if (len == 0)
449 {
450 static const char curwd[] = "./";
451 cp = (char *) curwd;
452 }
453
454 /* Remove trailing slashes (except for "/"). */
455 while (len > 1 && cp[len - 1] == '/')
456 --len;
457
458 /* Now add one if there is none so far. */
459 if (len > 0 && cp[len - 1] != '/')
460 cp[len++] = '/';
461
462 /* Make sure we don't use untrusted directories if we run SUID. */
463 if (__glibc_unlikely (check_trusted) && !is_trusted_path (cp, len))
464 {
465 free (to_free);
466 continue;
467 }
468
469 /* See if this directory is already known. */
470 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
471 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
472 break;
473
474 if (dirp != NULL)
475 {
476 /* It is available, see whether it's on our own list. */
477 size_t cnt;
478 for (cnt = 0; cnt < nelems; ++cnt)
479 if (result[cnt] == dirp)
480 break;
481
482 if (cnt == nelems)
483 result[nelems++] = dirp;
484 }
485 else
486 {
487 size_t cnt;
488 enum r_dir_status init_val;
489 size_t where_len = where ? strlen (where) + 1 : 0;
490
491 /* It's a new directory. Create an entry and add it. */
492 dirp = (struct r_search_path_elem *)
493 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
494 + where_len + len + 1);
495 if (dirp == NULL)
496 _dl_signal_error (ENOMEM, NULL, NULL,
497 N_("cannot create cache for search path"));
498
499 dirp->dirname = ((char *) dirp + sizeof (*dirp)
500 + ncapstr * sizeof (enum r_dir_status));
501 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
502 dirp->dirnamelen = len;
503
504 if (len > max_dirnamelen)
505 max_dirnamelen = len;
506
507 /* We have to make sure all the relative directories are
508 never ignored. The current directory might change and
509 all our saved information would be void. */
510 init_val = cp[0] != '/' ? existing : unknown;
511 for (cnt = 0; cnt < ncapstr; ++cnt)
512 dirp->status[cnt] = init_val;
513
514 dirp->what = what;
515 if (__glibc_likely (where != NULL))
516 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
517 + (ncapstr * sizeof (enum r_dir_status)),
518 where, where_len);
519 else
520 dirp->where = NULL;
521
522 dirp->next = GL(dl_all_dirs);
523 GL(dl_all_dirs) = dirp;
524
525 /* Put it in the result array. */
526 result[nelems++] = dirp;
527 }
528 free (to_free);
529 }
530
531 /* Terminate the array. */
532 result[nelems] = NULL;
533
534 return result;
535 }
536
537
538 static bool
539 decompose_rpath (struct r_search_path_struct *sps,
540 const char *rpath, struct link_map *l, const char *what)
541 {
542 /* Make a copy we can work with. */
543 const char *where = l->l_name;
544 char *copy;
545 char *cp;
546 struct r_search_path_elem **result;
547 size_t nelems;
548 /* Initialize to please the compiler. */
549 const char *errstring = NULL;
550
551 /* First see whether we must forget the RUNPATH and RPATH from this
552 object. */
553 if (__glibc_unlikely (GLRO(dl_inhibit_rpath) != NULL)
554 && !__libc_enable_secure)
555 {
556 const char *inhp = GLRO(dl_inhibit_rpath);
557
558 do
559 {
560 const char *wp = where;
561
562 while (*inhp == *wp && *wp != '\0')
563 {
564 ++inhp;
565 ++wp;
566 }
567
568 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
569 {
570 /* This object is on the list of objects for which the
571 RUNPATH and RPATH must not be used. */
572 sps->dirs = (void *) -1;
573 return false;
574 }
575
576 while (*inhp != '\0')
577 if (*inhp++ == ':')
578 break;
579 }
580 while (*inhp != '\0');
581 }
582
583 /* Make a writable copy. */
584 copy = __strdup (rpath);
585 if (copy == NULL)
586 {
587 errstring = N_("cannot create RUNPATH/RPATH copy");
588 goto signal_error;
589 }
590
591 /* Ignore empty rpaths. */
592 if (*copy == 0)
593 {
594 free (copy);
595 sps->dirs = (struct r_search_path_elem **) -1;
596 return false;
597 }
598
599 /* Count the number of necessary elements in the result array. */
600 nelems = 0;
601 for (cp = copy; *cp != '\0'; ++cp)
602 if (*cp == ':')
603 ++nelems;
604
605 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
606 number of necessary entries. */
607 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
608 * sizeof (*result));
609 if (result == NULL)
610 {
611 free (copy);
612 errstring = N_("cannot create cache for search path");
613 signal_error:
614 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
615 }
616
617 fillin_rpath (copy, result, ":", 0, what, where, l);
618
619 /* Free the copied RPATH string. `fillin_rpath' make own copies if
620 necessary. */
621 free (copy);
622
623 sps->dirs = result;
624 /* The caller will change this value if we haven't used a real malloc. */
625 sps->malloced = 1;
626 return true;
627 }
628
629 /* Make sure cached path information is stored in *SP
630 and return true if there are any paths to search there. */
631 static bool
632 cache_rpath (struct link_map *l,
633 struct r_search_path_struct *sp,
634 int tag,
635 const char *what)
636 {
637 if (sp->dirs == (void *) -1)
638 return false;
639
640 if (sp->dirs != NULL)
641 return true;
642
643 if (l->l_info[tag] == NULL)
644 {
645 /* There is no path. */
646 sp->dirs = (void *) -1;
647 return false;
648 }
649
650 /* Make sure the cache information is available. */
651 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
652 + l->l_info[tag]->d_un.d_val),
653 l, what);
654 }
655
656
657 void
658 _dl_init_paths (const char *llp)
659 {
660 size_t idx;
661 const char *strp;
662 struct r_search_path_elem *pelem, **aelem;
663 size_t round_size;
664 struct link_map __attribute__ ((unused)) *l = NULL;
665 /* Initialize to please the compiler. */
666 const char *errstring = NULL;
667
668 /* Fill in the information about the application's RPATH and the
669 directories addressed by the LD_LIBRARY_PATH environment variable. */
670
671 /* Get the capabilities. */
672 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
673 &ncapstr, &max_capstrlen);
674
675 /* First set up the rest of the default search directory entries. */
676 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
677 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
678 if (rtld_search_dirs.dirs == NULL)
679 {
680 errstring = N_("cannot create search path array");
681 signal_error:
682 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
683 }
684
685 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
686 + ncapstr * sizeof (enum r_dir_status))
687 / sizeof (struct r_search_path_elem));
688
689 rtld_search_dirs.dirs[0] = malloc (nsystem_dirs_len * round_size
690 * sizeof (*rtld_search_dirs.dirs[0]));
691 if (rtld_search_dirs.dirs[0] == NULL)
692 {
693 errstring = N_("cannot create cache for search path");
694 goto signal_error;
695 }
696
697 rtld_search_dirs.malloced = 0;
698 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
699 strp = system_dirs;
700 idx = 0;
701
702 do
703 {
704 size_t cnt;
705
706 *aelem++ = pelem;
707
708 pelem->what = "system search path";
709 pelem->where = NULL;
710
711 pelem->dirname = strp;
712 pelem->dirnamelen = system_dirs_len[idx];
713 strp += system_dirs_len[idx] + 1;
714
715 /* System paths must be absolute. */
716 assert (pelem->dirname[0] == '/');
717 for (cnt = 0; cnt < ncapstr; ++cnt)
718 pelem->status[cnt] = unknown;
719
720 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
721
722 pelem += round_size;
723 }
724 while (idx < nsystem_dirs_len);
725
726 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
727 *aelem = NULL;
728
729 #ifdef SHARED
730 /* This points to the map of the main object. */
731 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
732 if (l != NULL)
733 {
734 assert (l->l_type != lt_loaded);
735
736 if (l->l_info[DT_RUNPATH])
737 {
738 /* Allocate room for the search path and fill in information
739 from RUNPATH. */
740 decompose_rpath (&l->l_runpath_dirs,
741 (const void *) (D_PTR (l, l_info[DT_STRTAB])
742 + l->l_info[DT_RUNPATH]->d_un.d_val),
743 l, "RUNPATH");
744 /* During rtld init the memory is allocated by the stub malloc,
745 prevent any attempt to free it by the normal malloc. */
746 l->l_runpath_dirs.malloced = 0;
747
748 /* The RPATH is ignored. */
749 l->l_rpath_dirs.dirs = (void *) -1;
750 }
751 else
752 {
753 l->l_runpath_dirs.dirs = (void *) -1;
754
755 if (l->l_info[DT_RPATH])
756 {
757 /* Allocate room for the search path and fill in information
758 from RPATH. */
759 decompose_rpath (&l->l_rpath_dirs,
760 (const void *) (D_PTR (l, l_info[DT_STRTAB])
761 + l->l_info[DT_RPATH]->d_un.d_val),
762 l, "RPATH");
763 /* During rtld init the memory is allocated by the stub
764 malloc, prevent any attempt to free it by the normal
765 malloc. */
766 l->l_rpath_dirs.malloced = 0;
767 }
768 else
769 l->l_rpath_dirs.dirs = (void *) -1;
770 }
771 }
772 #endif /* SHARED */
773
774 if (llp != NULL && *llp != '\0')
775 {
776 size_t nllp;
777 const char *cp = llp;
778 char *llp_tmp;
779
780 #ifdef SHARED
781 /* Expand DSTs. */
782 size_t cnt = DL_DST_COUNT (llp, 1);
783 if (__glibc_likely (cnt == 0))
784 llp_tmp = strdupa (llp);
785 else
786 {
787 /* Determine the length of the substituted string. */
788 size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
789
790 /* Allocate the necessary memory. */
791 llp_tmp = (char *) alloca (total + 1);
792 llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
793 }
794 #else
795 llp_tmp = strdupa (llp);
796 #endif
797
798 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
799 elements it has. */
800 nllp = 1;
801 while (*cp)
802 {
803 if (*cp == ':' || *cp == ';')
804 ++nllp;
805 ++cp;
806 }
807
808 env_path_list.dirs = (struct r_search_path_elem **)
809 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
810 if (env_path_list.dirs == NULL)
811 {
812 errstring = N_("cannot create cache for search path");
813 goto signal_error;
814 }
815
816 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
817 __libc_enable_secure, "LD_LIBRARY_PATH",
818 NULL, l);
819
820 if (env_path_list.dirs[0] == NULL)
821 {
822 free (env_path_list.dirs);
823 env_path_list.dirs = (void *) -1;
824 }
825
826 env_path_list.malloced = 0;
827 }
828 else
829 env_path_list.dirs = (void *) -1;
830 }
831
832
833 static void
834 __attribute__ ((noreturn, noinline))
835 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
836 const char *msg, struct r_debug *r, Lmid_t nsid)
837 {
838 /* The file might already be closed. */
839 if (fd != -1)
840 (void) __close (fd);
841 if (l != NULL && l->l_origin != (char *) -1l)
842 free ((char *) l->l_origin);
843 free (l);
844 free (realname);
845
846 if (r != NULL)
847 {
848 r->r_state = RT_CONSISTENT;
849 _dl_debug_state ();
850 LIBC_PROBE (map_failed, 2, nsid, r);
851 }
852
853 _dl_signal_error (code, name, NULL, msg);
854 }
855
856
857 /* Map in the shared object NAME, actually located in REALNAME, and already
858 opened on FD. */
859
860 #ifndef EXTERNAL_MAP_FROM_FD
861 static
862 #endif
863 struct link_map *
864 _dl_map_object_from_fd (const char *name, const char *origname, int fd,
865 struct filebuf *fbp, char *realname,
866 struct link_map *loader, int l_type, int mode,
867 void **stack_endp, Lmid_t nsid)
868 {
869 struct link_map *l = NULL;
870 const ElfW(Ehdr) *header;
871 const ElfW(Phdr) *phdr;
872 const ElfW(Phdr) *ph;
873 size_t maplength;
874 int type;
875 /* Initialize to keep the compiler happy. */
876 const char *errstring = NULL;
877 int errval = 0;
878 struct r_debug *r = _dl_debug_initialize (0, nsid);
879 bool make_consistent = false;
880
881 /* Get file information. */
882 struct r_file_id id;
883 if (__glibc_unlikely (!_dl_get_file_id (fd, &id)))
884 {
885 errstring = N_("cannot stat shared object");
886 call_lose_errno:
887 errval = errno;
888 call_lose:
889 lose (errval, fd, name, realname, l, errstring,
890 make_consistent ? r : NULL, nsid);
891 }
892
893 /* Look again to see if the real name matched another already loaded. */
894 for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
895 if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
896 {
897 /* The object is already loaded.
898 Just bump its reference count and return it. */
899 __close (fd);
900
901 /* If the name is not in the list of names for this object add
902 it. */
903 free (realname);
904 add_name_to_object (l, name);
905
906 return l;
907 }
908
909 #ifdef SHARED
910 /* When loading into a namespace other than the base one we must
911 avoid loading ld.so since there can only be one copy. Ever. */
912 if (__glibc_unlikely (nsid != LM_ID_BASE)
913 && (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
914 || _dl_name_match_p (name, &GL(dl_rtld_map))))
915 {
916 /* This is indeed ld.so. Create a new link_map which refers to
917 the real one for almost everything. */
918 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
919 if (l == NULL)
920 goto fail_new;
921
922 /* Refer to the real descriptor. */
923 l->l_real = &GL(dl_rtld_map);
924
925 /* No need to bump the refcount of the real object, ld.so will
926 never be unloaded. */
927 __close (fd);
928
929 /* Add the map for the mirrored object to the object list. */
930 _dl_add_to_namespace_list (l, nsid);
931
932 return l;
933 }
934 #endif
935
936 if (mode & RTLD_NOLOAD)
937 {
938 /* We are not supposed to load the object unless it is already
939 loaded. So return now. */
940 free (realname);
941 __close (fd);
942 return NULL;
943 }
944
945 /* Print debugging message. */
946 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
947 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
948
949 /* This is the ELF header. We read it in `open_verify'. */
950 header = (void *) fbp->buf;
951
952 #ifndef MAP_ANON
953 # define MAP_ANON 0
954 if (_dl_zerofd == -1)
955 {
956 _dl_zerofd = _dl_sysdep_open_zero_fill ();
957 if (_dl_zerofd == -1)
958 {
959 free (realname);
960 __close (fd);
961 _dl_signal_error (errno, NULL, NULL,
962 N_("cannot open zero fill device"));
963 }
964 }
965 #endif
966
967 /* Signal that we are going to add new objects. */
968 if (r->r_state == RT_CONSISTENT)
969 {
970 #ifdef SHARED
971 /* Auditing checkpoint: we are going to add new objects. */
972 if ((mode & __RTLD_AUDIT) == 0
973 && __glibc_unlikely (GLRO(dl_naudit) > 0))
974 {
975 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
976 /* Do not call the functions for any auditing object. */
977 if (head->l_auditing == 0)
978 {
979 struct audit_ifaces *afct = GLRO(dl_audit);
980 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
981 {
982 if (afct->activity != NULL)
983 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
984
985 afct = afct->next;
986 }
987 }
988 }
989 #endif
990
991 /* Notify the debugger we have added some objects. We need to
992 call _dl_debug_initialize in a static program in case dynamic
993 linking has not been used before. */
994 r->r_state = RT_ADD;
995 _dl_debug_state ();
996 LIBC_PROBE (map_start, 2, nsid, r);
997 make_consistent = true;
998 }
999 else
1000 assert (r->r_state == RT_ADD);
1001
1002 /* Enter the new object in the list of loaded objects. */
1003 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1004 if (__glibc_unlikely (l == NULL))
1005 {
1006 #ifdef SHARED
1007 fail_new:
1008 #endif
1009 errstring = N_("cannot create shared object descriptor");
1010 goto call_lose_errno;
1011 }
1012
1013 /* Extract the remaining details we need from the ELF header
1014 and then read in the program header table. */
1015 l->l_entry = header->e_entry;
1016 type = header->e_type;
1017 l->l_phnum = header->e_phnum;
1018
1019 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1020 if (header->e_phoff + maplength <= (size_t) fbp->len)
1021 phdr = (void *) (fbp->buf + header->e_phoff);
1022 else
1023 {
1024 phdr = alloca (maplength);
1025 __lseek (fd, header->e_phoff, SEEK_SET);
1026 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1027 {
1028 errstring = N_("cannot read file data");
1029 goto call_lose_errno;
1030 }
1031 }
1032
1033 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1034 * executable. Other platforms default to a nonexecutable stack and don't
1035 * need PT_GNU_STACK to do so. */
1036 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1037
1038 {
1039 /* Scan the program header table, collecting its load commands. */
1040 struct loadcmd loadcmds[l->l_phnum];
1041 size_t nloadcmds = 0;
1042 bool has_holes = false;
1043
1044 /* The struct is initialized to zero so this is not necessary:
1045 l->l_ld = 0;
1046 l->l_phdr = 0;
1047 l->l_addr = 0; */
1048 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1049 switch (ph->p_type)
1050 {
1051 /* These entries tell us where to find things once the file's
1052 segments are mapped in. We record the addresses it says
1053 verbatim, and later correct for the run-time load address. */
1054 case PT_DYNAMIC:
1055 if (ph->p_filesz)
1056 {
1057 /* Debuginfo only files from "objcopy --only-keep-debug"
1058 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1059 such a segment to avoid a crash later. */
1060 l->l_ld = (void *) ph->p_vaddr;
1061 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1062 }
1063 break;
1064
1065 case PT_PHDR:
1066 l->l_phdr = (void *) ph->p_vaddr;
1067 break;
1068
1069 case PT_LOAD:
1070 /* A load command tells us to map in part of the file.
1071 We record the load commands and process them all later. */
1072 if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0))
1073 {
1074 errstring = N_("ELF load command alignment not page-aligned");
1075 goto call_lose;
1076 }
1077 if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
1078 & (ph->p_align - 1)) != 0))
1079 {
1080 errstring
1081 = N_("ELF load command address/offset not properly aligned");
1082 goto call_lose;
1083 }
1084
1085 struct loadcmd *c = &loadcmds[nloadcmds++];
1086 c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
1087 c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
1088 c->dataend = ph->p_vaddr + ph->p_filesz;
1089 c->allocend = ph->p_vaddr + ph->p_memsz;
1090 c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
1091
1092 /* Determine whether there is a gap between the last segment
1093 and this one. */
1094 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1095 has_holes = true;
1096
1097 /* Optimize a common case. */
1098 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1099 c->prot = (PF_TO_PROT
1100 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1101 #else
1102 c->prot = 0;
1103 if (ph->p_flags & PF_R)
1104 c->prot |= PROT_READ;
1105 if (ph->p_flags & PF_W)
1106 c->prot |= PROT_WRITE;
1107 if (ph->p_flags & PF_X)
1108 c->prot |= PROT_EXEC;
1109 #endif
1110 break;
1111
1112 case PT_TLS:
1113 if (ph->p_memsz == 0)
1114 /* Nothing to do for an empty segment. */
1115 break;
1116
1117 l->l_tls_blocksize = ph->p_memsz;
1118 l->l_tls_align = ph->p_align;
1119 if (ph->p_align == 0)
1120 l->l_tls_firstbyte_offset = 0;
1121 else
1122 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1123 l->l_tls_initimage_size = ph->p_filesz;
1124 /* Since we don't know the load address yet only store the
1125 offset. We will adjust it later. */
1126 l->l_tls_initimage = (void *) ph->p_vaddr;
1127
1128 /* If not loading the initial set of shared libraries,
1129 check whether we should permit loading a TLS segment. */
1130 if (__glibc_likely (l->l_type == lt_library)
1131 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1132 not set up TLS data structures, so don't use them now. */
1133 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL))
1134 {
1135 /* Assign the next available module ID. */
1136 l->l_tls_modid = _dl_next_tls_modid ();
1137 break;
1138 }
1139
1140 #ifdef SHARED
1141 /* We are loading the executable itself when the dynamic
1142 linker was executed directly. The setup will happen
1143 later. Otherwise, the TLS data structures are already
1144 initialized, and we assigned a TLS modid above. */
1145 assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
1146 #else
1147 assert (false && "TLS not initialized in static application");
1148 #endif
1149 break;
1150
1151 case PT_GNU_STACK:
1152 stack_flags = ph->p_flags;
1153 break;
1154
1155 case PT_GNU_RELRO:
1156 l->l_relro_addr = ph->p_vaddr;
1157 l->l_relro_size = ph->p_memsz;
1158 break;
1159 }
1160
1161 if (__glibc_unlikely (nloadcmds == 0))
1162 {
1163 /* This only happens for a bogus object that will be caught with
1164 another error below. But we don't want to go through the
1165 calculations below using NLOADCMDS - 1. */
1166 errstring = N_("object file has no loadable segments");
1167 goto call_lose;
1168 }
1169
1170 if (__glibc_unlikely (type != ET_DYN)
1171 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
1172 {
1173 /* This object is loaded at a fixed address. This must never
1174 happen for objects loaded with dlopen. */
1175 errstring = N_("cannot dynamically load executable");
1176 goto call_lose;
1177 }
1178
1179 /* Length of the sections to be loaded. */
1180 maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
1181
1182 /* Now process the load commands and map segments into memory.
1183 This is responsible for filling in:
1184 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1185 */
1186 errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
1187 maplength, has_holes, loader);
1188 if (__glibc_unlikely (errstring != NULL))
1189 goto call_lose;
1190 }
1191
1192 if (l->l_ld == 0)
1193 {
1194 if (__glibc_unlikely (type == ET_DYN))
1195 {
1196 errstring = N_("object file has no dynamic section");
1197 goto call_lose;
1198 }
1199 }
1200 else
1201 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1202
1203 elf_get_dynamic_info (l, NULL);
1204
1205 /* Make sure we are not dlopen'ing an object that has the
1206 DF_1_NOOPEN flag set. */
1207 if (__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1208 && (mode & __RTLD_DLOPEN))
1209 {
1210 /* We are not supposed to load this object. Free all resources. */
1211 _dl_unmap_segments (l);
1212
1213 if (!l->l_libname->dont_free)
1214 free (l->l_libname);
1215
1216 if (l->l_phdr_allocated)
1217 free ((void *) l->l_phdr);
1218
1219 errstring = N_("shared object cannot be dlopen()ed");
1220 goto call_lose;
1221 }
1222
1223 if (l->l_phdr == NULL)
1224 {
1225 /* The program header is not contained in any of the segments.
1226 We have to allocate memory ourself and copy it over from out
1227 temporary place. */
1228 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1229 * sizeof (ElfW(Phdr)));
1230 if (newp == NULL)
1231 {
1232 errstring = N_("cannot allocate memory for program header");
1233 goto call_lose_errno;
1234 }
1235
1236 l->l_phdr = memcpy (newp, phdr,
1237 (header->e_phnum * sizeof (ElfW(Phdr))));
1238 l->l_phdr_allocated = 1;
1239 }
1240 else
1241 /* Adjust the PT_PHDR value by the runtime load address. */
1242 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1243
1244 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
1245 {
1246 if (__glibc_unlikely (__check_caller (RETURN_ADDRESS (0), allow_ldso) != 0))
1247 {
1248 errstring = N_("invalid caller");
1249 goto call_lose;
1250 }
1251
1252 /* The stack is presently not executable, but this module
1253 requires that it be executable. We must change the
1254 protection of the variable which contains the flags used in
1255 the mprotect calls. */
1256 #ifdef SHARED
1257 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1258 {
1259 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1260 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1261
1262 struct link_map *const m = &GL(dl_rtld_map);
1263 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1264 + m->l_relro_size)
1265 & -GLRO(dl_pagesize));
1266 if (__glibc_likely (p + s <= relro_end))
1267 {
1268 /* The variable lies in the region protected by RELRO. */
1269 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1270 {
1271 errstring = N_("cannot change memory protections");
1272 goto call_lose_errno;
1273 }
1274 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1275 __mprotect ((void *) p, s, PROT_READ);
1276 }
1277 else
1278 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1279 }
1280 else
1281 #endif
1282 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1283
1284 #ifdef check_consistency
1285 check_consistency ();
1286 #endif
1287
1288 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1289 if (errval)
1290 {
1291 errstring = N_("\
1292 cannot enable executable stack as shared object requires");
1293 goto call_lose;
1294 }
1295 }
1296
1297 /* Adjust the address of the TLS initialization image. */
1298 if (l->l_tls_initimage != NULL)
1299 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1300
1301 /* We are done mapping in the file. We no longer need the descriptor. */
1302 if (__glibc_unlikely (__close (fd) != 0))
1303 {
1304 errstring = N_("cannot close file descriptor");
1305 goto call_lose_errno;
1306 }
1307 /* Signal that we closed the file. */
1308 fd = -1;
1309
1310 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1311 assert (type != ET_EXEC || l->l_type == lt_executable);
1312
1313 l->l_entry += l->l_addr;
1314
1315 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1316 _dl_debug_printf ("\
1317 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1318 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1319 (int) sizeof (void *) * 2,
1320 (unsigned long int) l->l_ld,
1321 (int) sizeof (void *) * 2,
1322 (unsigned long int) l->l_addr,
1323 (int) sizeof (void *) * 2, maplength,
1324 (int) sizeof (void *) * 2,
1325 (unsigned long int) l->l_entry,
1326 (int) sizeof (void *) * 2,
1327 (unsigned long int) l->l_phdr,
1328 (int) sizeof (void *) * 2, l->l_phnum);
1329
1330 /* Set up the symbol hash table. */
1331 _dl_setup_hash (l);
1332
1333 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1334 have to do this for the main map. */
1335 if ((mode & RTLD_DEEPBIND) == 0
1336 && __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
1337 && &l->l_searchlist != l->l_scope[0])
1338 {
1339 /* Create an appropriate searchlist. It contains only this map.
1340 This is the definition of DT_SYMBOLIC in SysVr4. */
1341 l->l_symbolic_searchlist.r_list[0] = l;
1342 l->l_symbolic_searchlist.r_nlist = 1;
1343
1344 /* Now move the existing entries one back. */
1345 memmove (&l->l_scope[1], &l->l_scope[0],
1346 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1347
1348 /* Now add the new entry. */
1349 l->l_scope[0] = &l->l_symbolic_searchlist;
1350 }
1351
1352 /* Remember whether this object must be initialized first. */
1353 if (l->l_flags_1 & DF_1_INITFIRST)
1354 GL(dl_initfirst) = l;
1355
1356 /* Finally the file information. */
1357 l->l_file_id = id;
1358
1359 #ifdef SHARED
1360 /* When auditing is used the recorded names might not include the
1361 name by which the DSO is actually known. Add that as well. */
1362 if (__glibc_unlikely (origname != NULL))
1363 add_name_to_object (l, origname);
1364 #else
1365 /* Audit modules only exist when linking is dynamic so ORIGNAME
1366 cannot be non-NULL. */
1367 assert (origname == NULL);
1368 #endif
1369
1370 /* When we profile the SONAME might be needed for something else but
1371 loading. Add it right away. */
1372 if (__glibc_unlikely (GLRO(dl_profile) != NULL)
1373 && l->l_info[DT_SONAME] != NULL)
1374 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1375 + l->l_info[DT_SONAME]->d_un.d_val));
1376
1377 #ifdef DL_AFTER_LOAD
1378 DL_AFTER_LOAD (l);
1379 #endif
1380
1381 /* Now that the object is fully initialized add it to the object list. */
1382 _dl_add_to_namespace_list (l, nsid);
1383
1384 #ifdef SHARED
1385 /* Auditing checkpoint: we have a new object. */
1386 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1387 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1388 {
1389 struct audit_ifaces *afct = GLRO(dl_audit);
1390 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1391 {
1392 if (afct->objopen != NULL)
1393 {
1394 l->l_audit[cnt].bindflags
1395 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1396
1397 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1398 }
1399
1400 afct = afct->next;
1401 }
1402 }
1403 #endif
1404
1405 return l;
1406 }
1407 \f
1408 /* Print search path. */
1409 static void
1410 print_search_path (struct r_search_path_elem **list,
1411 const char *what, const char *name)
1412 {
1413 char buf[max_dirnamelen + max_capstrlen];
1414 int first = 1;
1415
1416 _dl_debug_printf (" search path=");
1417
1418 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1419 {
1420 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1421 size_t cnt;
1422
1423 for (cnt = 0; cnt < ncapstr; ++cnt)
1424 if ((*list)->status[cnt] != nonexisting)
1425 {
1426 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1427 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1428 cp[0] = '\0';
1429 else
1430 cp[-1] = '\0';
1431
1432 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1433 first = 0;
1434 }
1435
1436 ++list;
1437 }
1438
1439 if (name != NULL)
1440 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1441 DSO_FILENAME (name));
1442 else
1443 _dl_debug_printf_c ("\t\t(%s)\n", what);
1444 }
1445 \f
1446 /* Open a file and verify it is an ELF file for this architecture. We
1447 ignore only ELF files for other architectures. Non-ELF files and
1448 ELF files with different header information cause fatal errors since
1449 this could mean there is something wrong in the installation and the
1450 user might want to know about this.
1451
1452 If FD is not -1, then the file is already open and FD refers to it.
1453 In that case, FD is consumed for both successful and error returns. */
1454 static int
1455 open_verify (const char *name, int fd,
1456 struct filebuf *fbp, struct link_map *loader,
1457 int whatcode, int mode, bool *found_other_class, bool free_name)
1458 {
1459 /* This is the expected ELF header. */
1460 #define ELF32_CLASS ELFCLASS32
1461 #define ELF64_CLASS ELFCLASS64
1462 #ifndef VALID_ELF_HEADER
1463 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1464 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1465 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1466 #elif defined MORE_ELF_HEADER_DATA
1467 MORE_ELF_HEADER_DATA;
1468 #endif
1469 static const unsigned char expected[EI_NIDENT] =
1470 {
1471 [EI_MAG0] = ELFMAG0,
1472 [EI_MAG1] = ELFMAG1,
1473 [EI_MAG2] = ELFMAG2,
1474 [EI_MAG3] = ELFMAG3,
1475 [EI_CLASS] = ELFW(CLASS),
1476 [EI_DATA] = byteorder,
1477 [EI_VERSION] = EV_CURRENT,
1478 [EI_OSABI] = ELFOSABI_SYSV,
1479 [EI_ABIVERSION] = 0
1480 };
1481 static const struct
1482 {
1483 ElfW(Word) vendorlen;
1484 ElfW(Word) datalen;
1485 ElfW(Word) type;
1486 char vendor[4];
1487 } expected_note = { 4, 16, 1, "GNU" };
1488 /* Initialize it to make the compiler happy. */
1489 const char *errstring = NULL;
1490 int errval = 0;
1491
1492 #ifdef SHARED
1493 /* Give the auditing libraries a chance. */
1494 if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
1495 && loader->l_auditing == 0)
1496 {
1497 const char *original_name = name;
1498 struct audit_ifaces *afct = GLRO(dl_audit);
1499 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1500 {
1501 if (afct->objsearch != NULL)
1502 {
1503 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1504 whatcode);
1505 if (name == NULL)
1506 /* Ignore the path. */
1507 return -1;
1508 }
1509
1510 afct = afct->next;
1511 }
1512
1513 if (fd != -1 && name != original_name && strcmp (name, original_name))
1514 {
1515 /* An audit library changed what we're supposed to open,
1516 so FD no longer matches it. */
1517 __close (fd);
1518 fd = -1;
1519 }
1520 }
1521 #endif
1522
1523 if (fd == -1)
1524 /* Open the file. We always open files read-only. */
1525 fd = __open (name, O_RDONLY | O_CLOEXEC);
1526
1527 if (fd != -1)
1528 {
1529 ElfW(Ehdr) *ehdr;
1530 ElfW(Phdr) *phdr, *ph;
1531 ElfW(Word) *abi_note;
1532 unsigned int osversion;
1533 size_t maplength;
1534
1535 /* We successfully opened the file. Now verify it is a file
1536 we can use. */
1537 __set_errno (0);
1538 fbp->len = 0;
1539 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1540 /* Read in the header. */
1541 do
1542 {
1543 ssize_t retlen = __libc_read (fd, fbp->buf + fbp->len,
1544 sizeof (fbp->buf) - fbp->len);
1545 if (retlen <= 0)
1546 break;
1547 fbp->len += retlen;
1548 }
1549 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1550
1551 /* This is where the ELF header is loaded. */
1552 ehdr = (ElfW(Ehdr) *) fbp->buf;
1553
1554 /* Now run the tests. */
1555 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1556 {
1557 errval = errno;
1558 errstring = (errval == 0
1559 ? N_("file too short") : N_("cannot read file data"));
1560 call_lose:
1561 if (free_name)
1562 {
1563 char *realname = (char *) name;
1564 name = strdupa (realname);
1565 free (realname);
1566 }
1567 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1568 }
1569
1570 /* See whether the ELF header is what we expect. */
1571 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1572 EI_ABIVERSION)
1573 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1574 ehdr->e_ident[EI_ABIVERSION])
1575 || memcmp (&ehdr->e_ident[EI_PAD],
1576 &expected[EI_PAD],
1577 EI_NIDENT - EI_PAD) != 0))
1578 {
1579 /* Something is wrong. */
1580 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1581 if (*magp !=
1582 #if BYTE_ORDER == LITTLE_ENDIAN
1583 ((ELFMAG0 << (EI_MAG0 * 8)) |
1584 (ELFMAG1 << (EI_MAG1 * 8)) |
1585 (ELFMAG2 << (EI_MAG2 * 8)) |
1586 (ELFMAG3 << (EI_MAG3 * 8)))
1587 #else
1588 ((ELFMAG0 << (EI_MAG3 * 8)) |
1589 (ELFMAG1 << (EI_MAG2 * 8)) |
1590 (ELFMAG2 << (EI_MAG1 * 8)) |
1591 (ELFMAG3 << (EI_MAG0 * 8)))
1592 #endif
1593 )
1594 errstring = N_("invalid ELF header");
1595 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1596 {
1597 /* This is not a fatal error. On architectures where
1598 32-bit and 64-bit binaries can be run this might
1599 happen. */
1600 *found_other_class = true;
1601 goto close_and_out;
1602 }
1603 else if (ehdr->e_ident[EI_DATA] != byteorder)
1604 {
1605 if (BYTE_ORDER == BIG_ENDIAN)
1606 errstring = N_("ELF file data encoding not big-endian");
1607 else
1608 errstring = N_("ELF file data encoding not little-endian");
1609 }
1610 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1611 errstring
1612 = N_("ELF file version ident does not match current one");
1613 /* XXX We should be able so set system specific versions which are
1614 allowed here. */
1615 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1616 errstring = N_("ELF file OS ABI invalid");
1617 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1618 ehdr->e_ident[EI_ABIVERSION]))
1619 errstring = N_("ELF file ABI version invalid");
1620 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1621 EI_NIDENT - EI_PAD) != 0)
1622 errstring = N_("nonzero padding in e_ident");
1623 else
1624 /* Otherwise we don't know what went wrong. */
1625 errstring = N_("internal error");
1626
1627 goto call_lose;
1628 }
1629
1630 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1631 {
1632 errstring = N_("ELF file version does not match current one");
1633 goto call_lose;
1634 }
1635 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1636 goto close_and_out;
1637 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1638 && ehdr->e_type != ET_EXEC))
1639 {
1640 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1641 goto call_lose;
1642 }
1643 else if (__glibc_unlikely (ehdr->e_type == ET_EXEC
1644 && (mode & __RTLD_OPENEXEC) == 0))
1645 {
1646 /* BZ #16634. It is an error to dlopen ET_EXEC (unless
1647 __RTLD_OPENEXEC is explicitly set). We return error here
1648 so that code in _dl_map_object_from_fd does not try to set
1649 l_tls_modid for this module. */
1650
1651 errstring = N_("cannot dynamically load executable");
1652 goto call_lose;
1653 }
1654 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1655 {
1656 errstring = N_("ELF file's phentsize not the expected size");
1657 goto call_lose;
1658 }
1659
1660 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1661 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1662 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1663 else
1664 {
1665 phdr = alloca (maplength);
1666 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1667 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1668 {
1669 read_error:
1670 errval = errno;
1671 errstring = N_("cannot read file data");
1672 goto call_lose;
1673 }
1674 }
1675
1676 if (__glibc_unlikely (elf_machine_reject_phdr_p
1677 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1678 loader, fd)))
1679 goto close_and_out;
1680
1681 /* Check .note.ABI-tag if present. */
1682 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1683 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1684 {
1685 ElfW(Addr) size = ph->p_filesz;
1686 /* NB: Some PT_NOTE segment may have alignment value of 0
1687 or 1. gABI specifies that PT_NOTE segments should be
1688 aligned to 4 bytes in 32-bit objects and to 8 bytes in
1689 64-bit objects. As a Linux extension, we also support
1690 4 byte alignment in 64-bit objects. If p_align is less
1691 than 4, we treate alignment as 4 bytes since some note
1692 segments have 0 or 1 byte alignment. */
1693 ElfW(Addr) align = ph->p_align;
1694 if (align < 4)
1695 align = 4;
1696 else if (align != 4 && align != 8)
1697 continue;
1698
1699 if (ph->p_offset + size <= (size_t) fbp->len)
1700 abi_note = (void *) (fbp->buf + ph->p_offset);
1701 else
1702 {
1703 abi_note = alloca (size);
1704 __lseek (fd, ph->p_offset, SEEK_SET);
1705 if (__libc_read (fd, (void *) abi_note, size) != size)
1706 goto read_error;
1707 }
1708
1709 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1710 {
1711 ElfW(Addr) note_size
1712 = ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
1713 align);
1714
1715 if (size - 32 < note_size)
1716 {
1717 size = 0;
1718 break;
1719 }
1720 size -= note_size;
1721 abi_note = (void *) abi_note + note_size;
1722 }
1723
1724 if (size == 0)
1725 continue;
1726
1727 osversion = (abi_note[5] & 0xff) * 65536
1728 + (abi_note[6] & 0xff) * 256
1729 + (abi_note[7] & 0xff);
1730 if (abi_note[4] != __ABI_TAG_OS
1731 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1732 {
1733 close_and_out:
1734 __close (fd);
1735 __set_errno (ENOENT);
1736 fd = -1;
1737 }
1738
1739 break;
1740 }
1741 }
1742
1743 return fd;
1744 }
1745 \f
1746 /* Try to open NAME in one of the directories in *DIRSP.
1747 Return the fd, or -1. If successful, fill in *REALNAME
1748 with the malloc'd full directory name. If it turns out
1749 that none of the directories in *DIRSP exists, *DIRSP is
1750 replaced with (void *) -1, and the old value is free()d
1751 if MAY_FREE_DIRS is true. */
1752
1753 static int
1754 open_path (const char *name, size_t namelen, int mode,
1755 struct r_search_path_struct *sps, char **realname,
1756 struct filebuf *fbp, struct link_map *loader, int whatcode,
1757 bool *found_other_class)
1758 {
1759 struct r_search_path_elem **dirs = sps->dirs;
1760 char *buf;
1761 int fd = -1;
1762 const char *current_what = NULL;
1763 int any = 0;
1764
1765 if (__glibc_unlikely (dirs == NULL))
1766 /* We're called before _dl_init_paths when loading the main executable
1767 given on the command line when rtld is run directly. */
1768 return -1;
1769
1770 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1771 do
1772 {
1773 struct r_search_path_elem *this_dir = *dirs;
1774 size_t buflen = 0;
1775 size_t cnt;
1776 char *edp;
1777 int here_any = 0;
1778 int err;
1779
1780 /* If we are debugging the search for libraries print the path
1781 now if it hasn't happened now. */
1782 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1783 && current_what != this_dir->what)
1784 {
1785 current_what = this_dir->what;
1786 print_search_path (dirs, current_what, this_dir->where);
1787 }
1788
1789 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1790 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1791 {
1792 /* Skip this directory if we know it does not exist. */
1793 if (this_dir->status[cnt] == nonexisting)
1794 continue;
1795
1796 buflen =
1797 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1798 capstr[cnt].len),
1799 name, namelen)
1800 - buf);
1801
1802 /* Print name we try if this is wanted. */
1803 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1804 _dl_debug_printf (" trying file=%s\n", buf);
1805
1806 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1807 found_other_class, false);
1808 if (this_dir->status[cnt] == unknown)
1809 {
1810 if (fd != -1)
1811 this_dir->status[cnt] = existing;
1812 /* Do not update the directory information when loading
1813 auditing code. We must try to disturb the program as
1814 little as possible. */
1815 else if (loader == NULL
1816 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1817 {
1818 /* We failed to open machine dependent library. Let's
1819 test whether there is any directory at all. */
1820 struct stat64 st;
1821
1822 buf[buflen - namelen - 1] = '\0';
1823
1824 if (__xstat64 (_STAT_VER, buf, &st) != 0
1825 || ! S_ISDIR (st.st_mode))
1826 /* The directory does not exist or it is no directory. */
1827 this_dir->status[cnt] = nonexisting;
1828 else
1829 this_dir->status[cnt] = existing;
1830 }
1831 }
1832
1833 /* Remember whether we found any existing directory. */
1834 here_any |= this_dir->status[cnt] != nonexisting;
1835
1836 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1837 && __libc_enable_secure)
1838 {
1839 /* This is an extra security effort to make sure nobody can
1840 preload broken shared objects which are in the trusted
1841 directories and so exploit the bugs. */
1842 struct stat64 st;
1843
1844 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1845 || (st.st_mode & S_ISUID) == 0)
1846 {
1847 /* The shared object cannot be tested for being SUID
1848 or this bit is not set. In this case we must not
1849 use this object. */
1850 __close (fd);
1851 fd = -1;
1852 /* We simply ignore the file, signal this by setting
1853 the error value which would have been set by `open'. */
1854 errno = ENOENT;
1855 }
1856 }
1857 }
1858
1859 if (fd != -1)
1860 {
1861 *realname = (char *) malloc (buflen);
1862 if (*realname != NULL)
1863 {
1864 memcpy (*realname, buf, buflen);
1865 return fd;
1866 }
1867 else
1868 {
1869 /* No memory for the name, we certainly won't be able
1870 to load and link it. */
1871 __close (fd);
1872 return -1;
1873 }
1874 }
1875 if (here_any && (err = errno) != ENOENT && err != EACCES)
1876 /* The file exists and is readable, but something went wrong. */
1877 return -1;
1878
1879 /* Remember whether we found anything. */
1880 any |= here_any;
1881 }
1882 while (*++dirs != NULL);
1883
1884 /* Remove the whole path if none of the directories exists. */
1885 if (__glibc_unlikely (! any))
1886 {
1887 /* Paths which were allocated using the minimal malloc() in ld.so
1888 must not be freed using the general free() in libc. */
1889 if (sps->malloced)
1890 free (sps->dirs);
1891
1892 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1893 avoid writing into it. */
1894 if (sps != &rtld_search_dirs && sps != &env_path_list)
1895 sps->dirs = (void *) -1;
1896 }
1897
1898 return -1;
1899 }
1900
1901 /* Map in the shared object file NAME. */
1902
1903 struct link_map *
1904 _dl_map_object (struct link_map *loader, const char *name,
1905 int type, int trace_mode, int mode, Lmid_t nsid)
1906 {
1907 int fd;
1908 const char *origname = NULL;
1909 char *realname;
1910 char *name_copy;
1911 struct link_map *l;
1912 struct filebuf fb;
1913
1914 assert (nsid >= 0);
1915 assert (nsid < GL(dl_nns));
1916
1917 /* Look for this name among those already loaded. */
1918 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1919 {
1920 /* If the requested name matches the soname of a loaded object,
1921 use that object. Elide this check for names that have not
1922 yet been opened. */
1923 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
1924 continue;
1925 if (!_dl_name_match_p (name, l))
1926 {
1927 const char *soname;
1928
1929 if (__glibc_likely (l->l_soname_added)
1930 || l->l_info[DT_SONAME] == NULL)
1931 continue;
1932
1933 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1934 + l->l_info[DT_SONAME]->d_un.d_val);
1935 if (strcmp (name, soname) != 0)
1936 continue;
1937
1938 /* We have a match on a new name -- cache it. */
1939 add_name_to_object (l, soname);
1940 l->l_soname_added = 1;
1941 }
1942
1943 /* We have a match. */
1944 return l;
1945 }
1946
1947 /* Display information if we are debugging. */
1948 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1949 && loader != NULL)
1950 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
1951 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1952 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1953 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
1954
1955 #ifdef SHARED
1956 /* Give the auditing libraries a chance to change the name before we
1957 try anything. */
1958 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1959 && (loader == NULL || loader->l_auditing == 0))
1960 {
1961 struct audit_ifaces *afct = GLRO(dl_audit);
1962 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1963 {
1964 if (afct->objsearch != NULL)
1965 {
1966 const char *before = name;
1967 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1968 LA_SER_ORIG);
1969 if (name == NULL)
1970 {
1971 /* Do not try anything further. */
1972 fd = -1;
1973 goto no_file;
1974 }
1975 if (before != name && strcmp (before, name) != 0)
1976 {
1977 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1978 _dl_debug_printf ("audit changed filename %s -> %s\n",
1979 before, name);
1980
1981 if (origname == NULL)
1982 origname = before;
1983 }
1984 }
1985
1986 afct = afct->next;
1987 }
1988 }
1989 #endif
1990
1991 /* Will be true if we found a DSO which is of the other ELF class. */
1992 bool found_other_class = false;
1993
1994 if (strchr (name, '/') == NULL)
1995 {
1996 /* Search for NAME in several places. */
1997
1998 size_t namelen = strlen (name) + 1;
1999
2000 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2001 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2002
2003 fd = -1;
2004
2005 /* When the object has the RUNPATH information we don't use any
2006 RPATHs. */
2007 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2008 {
2009 /* This is the executable's map (if there is one). Make sure that
2010 we do not look at it twice. */
2011 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2012 bool did_main_map = false;
2013
2014 /* First try the DT_RPATH of the dependent object that caused NAME
2015 to be loaded. Then that object's dependent, and on up. */
2016 for (l = loader; l; l = l->l_loader)
2017 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2018 {
2019 fd = open_path (name, namelen, mode,
2020 &l->l_rpath_dirs,
2021 &realname, &fb, loader, LA_SER_RUNPATH,
2022 &found_other_class);
2023 if (fd != -1)
2024 break;
2025
2026 did_main_map |= l == main_map;
2027 }
2028
2029 /* If dynamically linked, try the DT_RPATH of the executable
2030 itself. NB: we do this for lookups in any namespace. */
2031 if (fd == -1 && !did_main_map
2032 && main_map != NULL && main_map->l_type != lt_loaded
2033 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2034 "RPATH"))
2035 fd = open_path (name, namelen, mode,
2036 &main_map->l_rpath_dirs,
2037 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2038 &found_other_class);
2039 }
2040
2041 /* Try the LD_LIBRARY_PATH environment variable. */
2042 if (fd == -1 && env_path_list.dirs != (void *) -1)
2043 fd = open_path (name, namelen, mode, &env_path_list,
2044 &realname, &fb,
2045 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2046 LA_SER_LIBPATH, &found_other_class);
2047
2048 /* Look at the RUNPATH information for this binary. */
2049 if (fd == -1 && loader != NULL
2050 && cache_rpath (loader, &loader->l_runpath_dirs,
2051 DT_RUNPATH, "RUNPATH"))
2052 fd = open_path (name, namelen, mode,
2053 &loader->l_runpath_dirs, &realname, &fb, loader,
2054 LA_SER_RUNPATH, &found_other_class);
2055
2056 if (fd == -1)
2057 {
2058 realname = _dl_sysdep_open_object (name, namelen, &fd);
2059 if (realname != NULL)
2060 {
2061 fd = open_verify (realname, fd,
2062 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2063 LA_SER_CONFIG, mode, &found_other_class,
2064 false);
2065 if (fd == -1)
2066 free (realname);
2067 }
2068 }
2069
2070 #ifdef USE_LDCONFIG
2071 if (fd == -1
2072 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2073 || ! __libc_enable_secure)
2074 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2075 {
2076 /* Check the list of libraries in the file /etc/ld.so.cache,
2077 for compatibility with Linux's ldconfig program. */
2078 char *cached = _dl_load_cache_lookup (name);
2079
2080 if (cached != NULL)
2081 {
2082 // XXX Correct to unconditionally default to namespace 0?
2083 l = (loader
2084 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2085 # ifdef SHARED
2086 ?: &GL(dl_rtld_map)
2087 # endif
2088 );
2089
2090 /* If the loader has the DF_1_NODEFLIB flag set we must not
2091 use a cache entry from any of these directories. */
2092 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2093 {
2094 const char *dirp = system_dirs;
2095 unsigned int cnt = 0;
2096
2097 do
2098 {
2099 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2100 {
2101 /* The prefix matches. Don't use the entry. */
2102 free (cached);
2103 cached = NULL;
2104 break;
2105 }
2106
2107 dirp += system_dirs_len[cnt] + 1;
2108 ++cnt;
2109 }
2110 while (cnt < nsystem_dirs_len);
2111 }
2112
2113 if (cached != NULL)
2114 {
2115 fd = open_verify (cached, -1,
2116 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2117 LA_SER_CONFIG, mode, &found_other_class,
2118 false);
2119 if (__glibc_likely (fd != -1))
2120 realname = cached;
2121 else
2122 free (cached);
2123 }
2124 }
2125 }
2126 #endif
2127
2128 /* Finally, try the default path. */
2129 if (fd == -1
2130 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2131 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2132 && rtld_search_dirs.dirs != (void *) -1)
2133 fd = open_path (name, namelen, mode, &rtld_search_dirs,
2134 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2135
2136 /* Add another newline when we are tracing the library loading. */
2137 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2138 _dl_debug_printf ("\n");
2139 }
2140 else
2141 {
2142 /* The path may contain dynamic string tokens. */
2143 realname = (loader
2144 ? expand_dynamic_string_token (loader, name, 0)
2145 : __strdup (name));
2146 if (realname == NULL)
2147 fd = -1;
2148 else
2149 {
2150 fd = open_verify (realname, -1, &fb,
2151 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2152 &found_other_class, true);
2153 if (__glibc_unlikely (fd == -1))
2154 free (realname);
2155 }
2156 }
2157
2158 #ifdef SHARED
2159 no_file:
2160 #endif
2161 /* In case the LOADER information has only been provided to get to
2162 the appropriate RUNPATH/RPATH information we do not need it
2163 anymore. */
2164 if (mode & __RTLD_CALLMAP)
2165 loader = NULL;
2166
2167 if (__glibc_unlikely (fd == -1))
2168 {
2169 if (trace_mode
2170 && __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
2171 {
2172 /* We haven't found an appropriate library. But since we
2173 are only interested in the list of libraries this isn't
2174 so severe. Fake an entry with all the information we
2175 have. */
2176 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2177
2178 /* Allocate a new object map. */
2179 if ((name_copy = __strdup (name)) == NULL
2180 || (l = _dl_new_object (name_copy, name, type, loader,
2181 mode, nsid)) == NULL)
2182 {
2183 free (name_copy);
2184 _dl_signal_error (ENOMEM, name, NULL,
2185 N_("cannot create shared object descriptor"));
2186 }
2187 /* Signal that this is a faked entry. */
2188 l->l_faked = 1;
2189 /* Since the descriptor is initialized with zero we do not
2190 have do this here.
2191 l->l_reserved = 0; */
2192 l->l_buckets = &dummy_bucket;
2193 l->l_nbuckets = 1;
2194 l->l_relocated = 1;
2195
2196 /* Enter the object in the object list. */
2197 _dl_add_to_namespace_list (l, nsid);
2198
2199 return l;
2200 }
2201 else if (found_other_class)
2202 _dl_signal_error (0, name, NULL,
2203 ELFW(CLASS) == ELFCLASS32
2204 ? N_("wrong ELF class: ELFCLASS64")
2205 : N_("wrong ELF class: ELFCLASS32"));
2206 else
2207 _dl_signal_error (errno, name, NULL,
2208 N_("cannot open shared object file"));
2209 }
2210
2211 void *stack_end = __libc_stack_end;
2212 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2213 type, mode, &stack_end, nsid);
2214 }
2215
2216 struct add_path_state
2217 {
2218 bool counting;
2219 unsigned int idx;
2220 Dl_serinfo *si;
2221 char *allocptr;
2222 };
2223
2224 static void
2225 add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2226 unsigned int flags)
2227 {
2228 if (sps->dirs != (void *) -1)
2229 {
2230 struct r_search_path_elem **dirs = sps->dirs;
2231 do
2232 {
2233 const struct r_search_path_elem *const r = *dirs++;
2234 if (p->counting)
2235 {
2236 p->si->dls_cnt++;
2237 p->si->dls_size += MAX (2, r->dirnamelen);
2238 }
2239 else
2240 {
2241 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2242 sp->dls_name = p->allocptr;
2243 if (r->dirnamelen < 2)
2244 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2245 else
2246 p->allocptr = __mempcpy (p->allocptr,
2247 r->dirname, r->dirnamelen - 1);
2248 *p->allocptr++ = '\0';
2249 sp->dls_flags = flags;
2250 }
2251 }
2252 while (*dirs != NULL);
2253 }
2254 }
2255
2256 void
2257 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2258 {
2259 if (counting)
2260 {
2261 si->dls_cnt = 0;
2262 si->dls_size = 0;
2263 }
2264
2265 struct add_path_state p =
2266 {
2267 .counting = counting,
2268 .idx = 0,
2269 .si = si,
2270 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2271 };
2272
2273 # define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2274
2275 /* When the object has the RUNPATH information we don't use any RPATHs. */
2276 if (loader->l_info[DT_RUNPATH] == NULL)
2277 {
2278 /* First try the DT_RPATH of the dependent object that caused NAME
2279 to be loaded. Then that object's dependent, and on up. */
2280
2281 struct link_map *l = loader;
2282 do
2283 {
2284 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2285 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2286 l = l->l_loader;
2287 }
2288 while (l != NULL);
2289
2290 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2291 if (loader->l_ns == LM_ID_BASE)
2292 {
2293 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2294 if (l != NULL && l->l_type != lt_loaded && l != loader)
2295 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2296 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2297 }
2298 }
2299
2300 /* Try the LD_LIBRARY_PATH environment variable. */
2301 add_path (&p, &env_path_list, XXX_ENV);
2302
2303 /* Look at the RUNPATH information for this binary. */
2304 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2305 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2306
2307 /* XXX
2308 Here is where ld.so.cache gets checked, but we don't have
2309 a way to indicate that in the results for Dl_serinfo. */
2310
2311 /* Finally, try the default path. */
2312 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2313 add_path (&p, &rtld_search_dirs, XXX_default);
2314
2315 if (counting)
2316 /* Count the struct size before the string area, which we didn't
2317 know before we completed dls_cnt. */
2318 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;
2319 }