1/* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2019 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
34/* Type for the buffer we put the ELF header and hopefully the program
35 header. This buffer does not really have to be too large. In most
36 cases the program header follows the ELF header directly. If this
37 is not the case all bets are off and we can make the header
38 arbitrarily large and still won't get it read. This means the only
39 question is how large are the ELF and program header combined. The
40 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
41 bytes long. Each program header entry is again 32 and 56 bytes
42 long respectively. I.e., even with a file which has 10 program
43 header entries we only have to read 372B/624B respectively. Add to
44 this a bit of margin for program notes and reading 512B and 832B
45 for 32-bit and 64-bit files respecitvely is enough. If this
46 heuristic should really fail for some file the code in
47 `_dl_map_object_from_fd' knows how to recover. */
48struct filebuf
49{
50 ssize_t len;
51#if __WORDSIZE == 32
52# define FILEBUF_SIZE 512
53#else
54# define FILEBUF_SIZE 832
55#endif
56 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
57};
58
59#include "dynamic-link.h"
60#include <abi-tag.h>
61#include <stackinfo.h>
62#include <sysdep.h>
63#include <stap-probe.h>
64#include <libc-pointer-arith.h>
65#include <array_length.h>
66
67#include <dl-dst.h>
68#include <dl-load.h>
69#include <dl-map-segments.h>
70#include <dl-unmap-segments.h>
71#include <dl-machine-reject-phdr.h>
72#include <dl-sysdep-open.h>
73#include <dl-prop.h>
74#include <not-cancel.h>
75
76#include <endian.h>
77#if BYTE_ORDER == BIG_ENDIAN
78# define byteorder ELFDATA2MSB
79#elif BYTE_ORDER == LITTLE_ENDIAN
80# define byteorder ELFDATA2LSB
81#else
82# error "Unknown BYTE_ORDER " BYTE_ORDER
83# define byteorder ELFDATANONE
84#endif
85
86#define STRING(x) __STRING (x)
87
88
89int __stack_prot attribute_hidden attribute_relro
90#if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
91 = PROT_GROWSDOWN;
92#elif _STACK_GROWS_UP && defined PROT_GROWSUP
93 = PROT_GROWSUP;
94#else
95 = 0;
96#endif
97
98
99/* This is the decomposed LD_LIBRARY_PATH search path. */
100static struct r_search_path_struct env_path_list attribute_relro;
101
102/* List of the hardware capabilities we might end up using. */
103static const struct r_strlenpair *capstr attribute_relro;
104static size_t ncapstr attribute_relro;
105static size_t max_capstrlen attribute_relro;
106
107
108/* Get the generated information about the trusted directories. Use
109 an array of concatenated strings to avoid relocations. See
110 gen-trusted-dirs.awk. */
111#include "trusted-dirs.h"
112
113static const char system_dirs[] = SYSTEM_DIRS;
114static const size_t system_dirs_len[] =
115{
116 SYSTEM_DIRS_LEN
117};
118#define nsystem_dirs_len array_length (system_dirs_len)
119
120static bool
121is_trusted_path_normalize (const char *path, size_t len)
122{
123 if (len == 0)
124 return false;
125
126 char *npath = (char *) alloca (len + 2);
127 char *wnp = npath;
128 while (*path != '\0')
129 {
130 if (path[0] == '/')
131 {
132 if (path[1] == '.')
133 {
134 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
135 {
136 while (wnp > npath && *--wnp != '/')
137 ;
138 path += 3;
139 continue;
140 }
141 else if (path[2] == '/' || path[2] == '\0')
142 {
143 path += 2;
144 continue;
145 }
146 }
147
148 if (wnp > npath && wnp[-1] == '/')
149 {
150 ++path;
151 continue;
152 }
153 }
154
155 *wnp++ = *path++;
156 }
157
158 if (wnp == npath || wnp[-1] != '/')
159 *wnp++ = '/';
160
161 const char *trun = system_dirs;
162
163 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
164 {
165 if (wnp - npath >= system_dirs_len[idx]
166 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
167 /* Found it. */
168 return true;
169
170 trun += system_dirs_len[idx] + 1;
171 }
172
173 return false;
174}
175
176/* Given a substring starting at INPUT, just after the DST '$' start
177 token, determine if INPUT contains DST token REF, following the
178 ELF gABI rules for DSTs:
179
180 * Longest possible sequence using the rules (greedy).
181
182 * Must start with a $ (enforced by caller).
183
184 * Must follow $ with one underscore or ASCII [A-Za-z] (caller
185 follows these rules for REF) or '{' (start curly quoted name).
186
187 * Must follow first two characters with zero or more [A-Za-z0-9_]
188 (enforced by caller) or '}' (end curly quoted name).
189
190 If the sequence is a DST matching REF then the length of the DST
191 (excluding the $ sign but including curly braces, if any) is
192 returned, otherwise 0. */
193static size_t
194is_dst (const char *input, const char *ref)
195{
196 bool is_curly = false;
197
198 /* Is a ${...} input sequence? */
199 if (input[0] == '{')
200 {
201 is_curly = true;
202 ++input;
203 }
204
205 /* Check for matching name, following closing curly brace (if
206 required), or trailing characters which are part of an
207 identifier. */
208 size_t rlen = strlen (ref);
209 if (strncmp (input, ref, rlen) != 0
210 || (is_curly && input[rlen] != '}')
211 || ((input[rlen] >= 'A' && input[rlen] <= 'Z')
212 || (input[rlen] >= 'a' && input[rlen] <= 'z')
213 || (input[rlen] >= '0' && input[rlen] <= '9')
214 || (input[rlen] == '_')))
215 return 0;
216
217 if (is_curly)
218 /* Count the two curly braces. */
219 return rlen + 2;
220 else
221 return rlen;
222}
223
224/* INPUT should be the start of a path e.g DT_RPATH or name e.g.
225 DT_NEEDED. The return value is the number of known DSTs found. We
226 count all known DSTs regardless of __libc_enable_secure; the caller
227 is responsible for enforcing the security of the substitution rules
228 (usually _dl_dst_substitute). */
229size_t
230_dl_dst_count (const char *input)
231{
232 size_t cnt = 0;
233
234 input = strchr (input, '$');
235
236 /* Most likely there is no DST. */
237 if (__glibc_likely (input == NULL))
238 return 0;
239
240 do
241 {
242 size_t len;
243
244 ++input;
245 /* All DSTs must follow ELF gABI rules, see is_dst (). */
246 if ((len = is_dst (input, "ORIGIN")) != 0
247 || (len = is_dst (input, "PLATFORM")) != 0
248 || (len = is_dst (input, "LIB")) != 0)
249 ++cnt;
250
251 /* There may be more than one DST in the input. */
252 input = strchr (input + len, '$');
253 }
254 while (input != NULL);
255
256 return cnt;
257}
258
259/* Process INPUT for DSTs and store in RESULT using the information
260 from link map L to resolve the DSTs. This function only handles one
261 path at a time and does not handle colon-separated path lists (see
262 fillin_rpath ()). Lastly the size of result in bytes should be at
263 least equal to the value returned by DL_DST_REQUIRED. Note that it
264 is possible for a DT_NEEDED, DT_AUXILIARY, and DT_FILTER entries to
265 have colons, but we treat those as literal colons here, not as path
266 list delimeters. */
267char *
268_dl_dst_substitute (struct link_map *l, const char *input, char *result)
269{
270 /* Copy character-by-character from input into the working pointer
271 looking for any DSTs. We track the start of input and if we are
272 going to check for trusted paths, all of which are part of $ORIGIN
273 handling in SUID/SGID cases (see below). In some cases, like when
274 a DST cannot be replaced, we may set result to an empty string and
275 return. */
276 char *wp = result;
277 const char *start = input;
278 bool check_for_trusted = false;
279
280 do
281 {
282 if (__glibc_unlikely (*input == '$'))
283 {
284 const char *repl = NULL;
285 size_t len;
286
287 ++input;
288 if ((len = is_dst (input, "ORIGIN")) != 0)
289 {
290 /* For SUID/GUID programs we normally ignore the path with
291 $ORIGIN in DT_RUNPATH, or DT_RPATH. However, there is
292 one exception to this rule, and it is:
293
294 * $ORIGIN appears as the first path element, and is
295 the only string in the path or is immediately
296 followed by a path separator and the rest of the
297 path,
298
299 and ...
300
301 * The path is rooted in a trusted directory.
302
303 This exception allows such programs to reference
304 shared libraries in subdirectories of trusted
305 directories. The use case is one of general
306 organization and deployment flexibility.
307 Trusted directories are usually such paths as "/lib64"
308 or "/usr/lib64", and the usual RPATHs take the form of
309 [$ORIGIN/../$LIB/somedir]. */
310 if (__glibc_unlikely (__libc_enable_secure)
311 && !(input == start + 1
312 && (input[len] == '\0' || input[len] == '/')))
313 repl = (const char *) -1;
314 else
315 repl = l->l_origin;
316
317 check_for_trusted = (__libc_enable_secure
318 && l->l_type == lt_executable);
319 }
320 else if ((len = is_dst (input, "PLATFORM")) != 0)
321 repl = GLRO(dl_platform);
322 else if ((len = is_dst (input, "LIB")) != 0)
323 repl = DL_DST_LIB;
324
325 if (repl != NULL && repl != (const char *) -1)
326 {
327 wp = __stpcpy (wp, repl);
328 input += len;
329 }
330 else if (len != 0)
331 {
332 /* We found a valid DST that we know about, but we could
333 not find a replacement value for it, therefore we
334 cannot use this path and discard it. */
335 *result = '\0';
336 return result;
337 }
338 else
339 /* No DST we recognize. */
340 *wp++ = '$';
341 }
342 else
343 {
344 *wp++ = *input++;
345 }
346 }
347 while (*input != '\0');
348
349 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
350 path must be rooted in one of the trusted directories. The $LIB
351 and $PLATFORM DST cannot in any way be manipulated by the caller
352 because they are fixed values that are set by the dynamic loader
353 and therefore any paths using just $LIB or $PLATFORM need not be
354 checked for trust, the authors of the binaries themselves are
355 trusted to have designed this correctly. Only $ORIGIN is tested in
356 this way because it may be manipulated in some ways with hard
357 links. */
358 if (__glibc_unlikely (check_for_trusted)
359 && !is_trusted_path_normalize (result, wp - result))
360 {
361 *result = '\0';
362 return result;
363 }
364
365 *wp = '\0';
366
367 return result;
368}
369
370
371/* Return a malloc allocated copy of INPUT with all recognized DSTs
372 replaced. On some platforms it might not be possible to determine the
373 path from which the object belonging to the map is loaded. In this
374 case the path containing the DST is left out. On error NULL
375 is returned. */
376static char *
377expand_dynamic_string_token (struct link_map *l, const char *input)
378{
379 /* We make two runs over the string. First we determine how large the
380 resulting string is and then we copy it over. Since this is no
381 frequently executed operation we are looking here not for performance
382 but rather for code size. */
383 size_t cnt;
384 size_t total;
385 char *result;
386
387 /* Determine the number of DSTs. */
388 cnt = _dl_dst_count (input);
389
390 /* If we do not have to replace anything simply copy the string. */
391 if (__glibc_likely (cnt == 0))
392 return __strdup (input);
393
394 /* Determine the length of the substituted string. */
395 total = DL_DST_REQUIRED (l, input, strlen (input), cnt);
396
397 /* Allocate the necessary memory. */
398 result = (char *) malloc (total + 1);
399 if (result == NULL)
400 return NULL;
401
402 return _dl_dst_substitute (l, input, result);
403}
404
405
406/* Add `name' to the list of names for a particular shared object.
407 `name' is expected to have been allocated with malloc and will
408 be freed if the shared object already has this name.
409 Returns false if the object already had this name. */
410static void
411add_name_to_object (struct link_map *l, const char *name)
412{
413 struct libname_list *lnp, *lastp;
414 struct libname_list *newname;
415 size_t name_len;
416
417 lastp = NULL;
418 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
419 if (strcmp (name, lnp->name) == 0)
420 return;
421
422 name_len = strlen (name) + 1;
423 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
424 if (newname == NULL)
425 {
426 /* No more memory. */
427 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
428 return;
429 }
430 /* The object should have a libname set from _dl_new_object. */
431 assert (lastp != NULL);
432
433 newname->name = memcpy (newname + 1, name, name_len);
434 newname->next = NULL;
435 newname->dont_free = 0;
436 lastp->next = newname;
437}
438
439/* Standard search directories. */
440static struct r_search_path_struct rtld_search_dirs attribute_relro;
441
442static size_t max_dirnamelen;
443
444static struct r_search_path_elem **
445fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
446 const char *what, const char *where, struct link_map *l)
447{
448 char *cp;
449 size_t nelems = 0;
450
451 while ((cp = __strsep (&rpath, sep)) != NULL)
452 {
453 struct r_search_path_elem *dirp;
454 char *to_free = NULL;
455 size_t len = 0;
456
457 /* `strsep' can pass an empty string. */
458 if (*cp != '\0')
459 {
460 to_free = cp = expand_dynamic_string_token (l, cp);
461
462 /* expand_dynamic_string_token can return NULL in case of empty
463 path or memory allocation failure. */
464 if (cp == NULL)
465 continue;
466
467 /* Compute the length after dynamic string token expansion and
468 ignore empty paths. */
469 len = strlen (cp);
470 if (len == 0)
471 {
472 free (to_free);
473 continue;
474 }
475
476 /* Remove trailing slashes (except for "/"). */
477 while (len > 1 && cp[len - 1] == '/')
478 --len;
479
480 /* Now add one if there is none so far. */
481 if (len > 0 && cp[len - 1] != '/')
482 cp[len++] = '/';
483 }
484
485 /* See if this directory is already known. */
486 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
487 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
488 break;
489
490 if (dirp != NULL)
491 {
492 /* It is available, see whether it's on our own list. */
493 size_t cnt;
494 for (cnt = 0; cnt < nelems; ++cnt)
495 if (result[cnt] == dirp)
496 break;
497
498 if (cnt == nelems)
499 result[nelems++] = dirp;
500 }
501 else
502 {
503 size_t cnt;
504 enum r_dir_status init_val;
505 size_t where_len = where ? strlen (where) + 1 : 0;
506
507 /* It's a new directory. Create an entry and add it. */
508 dirp = (struct r_search_path_elem *)
509 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
510 + where_len + len + 1);
511 if (dirp == NULL)
512 _dl_signal_error (ENOMEM, NULL, NULL,
513 N_("cannot create cache for search path"));
514
515 dirp->dirname = ((char *) dirp + sizeof (*dirp)
516 + ncapstr * sizeof (enum r_dir_status));
517 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
518 dirp->dirnamelen = len;
519
520 if (len > max_dirnamelen)
521 max_dirnamelen = len;
522
523 /* We have to make sure all the relative directories are
524 never ignored. The current directory might change and
525 all our saved information would be void. */
526 init_val = cp[0] != '/' ? existing : unknown;
527 for (cnt = 0; cnt < ncapstr; ++cnt)
528 dirp->status[cnt] = init_val;
529
530 dirp->what = what;
531 if (__glibc_likely (where != NULL))
532 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
533 + (ncapstr * sizeof (enum r_dir_status)),
534 where, where_len);
535 else
536 dirp->where = NULL;
537
538 dirp->next = GL(dl_all_dirs);
539 GL(dl_all_dirs) = dirp;
540
541 /* Put it in the result array. */
542 result[nelems++] = dirp;
543 }
544 free (to_free);
545 }
546
547 /* Terminate the array. */
548 result[nelems] = NULL;
549
550 return result;
551}
552
553
554static bool
555decompose_rpath (struct r_search_path_struct *sps,
556 const char *rpath, struct link_map *l, const char *what)
557{
558 /* Make a copy we can work with. */
559 const char *where = l->l_name;
560 char *cp;
561 struct r_search_path_elem **result;
562 size_t nelems;
563 /* Initialize to please the compiler. */
564 const char *errstring = NULL;
565
566 /* First see whether we must forget the RUNPATH and RPATH from this
567 object. */
568 if (__glibc_unlikely (GLRO(dl_inhibit_rpath) != NULL)
569 && !__libc_enable_secure)
570 {
571 const char *inhp = GLRO(dl_inhibit_rpath);
572
573 do
574 {
575 const char *wp = where;
576
577 while (*inhp == *wp && *wp != '\0')
578 {
579 ++inhp;
580 ++wp;
581 }
582
583 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
584 {
585 /* This object is on the list of objects for which the
586 RUNPATH and RPATH must not be used. */
587 sps->dirs = (void *) -1;
588 return false;
589 }
590
591 while (*inhp != '\0')
592 if (*inhp++ == ':')
593 break;
594 }
595 while (*inhp != '\0');
596 }
597
598 /* Ignore empty rpaths. */
599 if (*rpath == '\0')
600 {
601 sps->dirs = (struct r_search_path_elem **) -1;
602 return false;
603 }
604
605 /* Make a writable copy. */
606 char *copy = __strdup (rpath);
607 if (copy == NULL)
608 {
609 errstring = N_("cannot create RUNPATH/RPATH copy");
610 goto signal_error;
611 }
612
613 /* Count the number of necessary elements in the result array. */
614 nelems = 0;
615 for (cp = copy; *cp != '\0'; ++cp)
616 if (*cp == ':')
617 ++nelems;
618
619 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
620 number of necessary entries. */
621 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
622 * sizeof (*result));
623 if (result == NULL)
624 {
625 free (copy);
626 errstring = N_("cannot create cache for search path");
627 signal_error:
628 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
629 }
630
631 fillin_rpath (copy, result, ":", what, where, l);
632
633 /* Free the copied RPATH string. `fillin_rpath' make own copies if
634 necessary. */
635 free (copy);
636
637 /* There is no path after expansion. */
638 if (result[0] == NULL)
639 {
640 free (result);
641 sps->dirs = (struct r_search_path_elem **) -1;
642 return false;
643 }
644
645 sps->dirs = result;
646 /* The caller will change this value if we haven't used a real malloc. */
647 sps->malloced = 1;
648 return true;
649}
650
651/* Make sure cached path information is stored in *SP
652 and return true if there are any paths to search there. */
653static bool
654cache_rpath (struct link_map *l,
655 struct r_search_path_struct *sp,
656 int tag,
657 const char *what)
658{
659 if (sp->dirs == (void *) -1)
660 return false;
661
662 if (sp->dirs != NULL)
663 return true;
664
665 if (l->l_info[tag] == NULL)
666 {
667 /* There is no path. */
668 sp->dirs = (void *) -1;
669 return false;
670 }
671
672 /* Make sure the cache information is available. */
673 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
674 + l->l_info[tag]->d_un.d_val),
675 l, what);
676}
677
678
679void
680_dl_init_paths (const char *llp)
681{
682 size_t idx;
683 const char *strp;
684 struct r_search_path_elem *pelem, **aelem;
685 size_t round_size;
686 struct link_map __attribute__ ((unused)) *l = NULL;
687 /* Initialize to please the compiler. */
688 const char *errstring = NULL;
689
690 /* Fill in the information about the application's RPATH and the
691 directories addressed by the LD_LIBRARY_PATH environment variable. */
692
693 /* Get the capabilities. */
694 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
695 &ncapstr, &max_capstrlen);
696
697 /* First set up the rest of the default search directory entries. */
698 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
699 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
700 if (rtld_search_dirs.dirs == NULL)
701 {
702 errstring = N_("cannot create search path array");
703 signal_error:
704 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
705 }
706
707 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
708 + ncapstr * sizeof (enum r_dir_status))
709 / sizeof (struct r_search_path_elem));
710
711 rtld_search_dirs.dirs[0] = malloc (nsystem_dirs_len * round_size
712 * sizeof (*rtld_search_dirs.dirs[0]));
713 if (rtld_search_dirs.dirs[0] == NULL)
714 {
715 errstring = N_("cannot create cache for search path");
716 goto signal_error;
717 }
718
719 rtld_search_dirs.malloced = 0;
720 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
721 strp = system_dirs;
722 idx = 0;
723
724 do
725 {
726 size_t cnt;
727
728 *aelem++ = pelem;
729
730 pelem->what = "system search path";
731 pelem->where = NULL;
732
733 pelem->dirname = strp;
734 pelem->dirnamelen = system_dirs_len[idx];
735 strp += system_dirs_len[idx] + 1;
736
737 /* System paths must be absolute. */
738 assert (pelem->dirname[0] == '/');
739 for (cnt = 0; cnt < ncapstr; ++cnt)
740 pelem->status[cnt] = unknown;
741
742 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
743
744 pelem += round_size;
745 }
746 while (idx < nsystem_dirs_len);
747
748 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
749 *aelem = NULL;
750
751#ifdef SHARED
752 /* This points to the map of the main object. */
753 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
754 if (l != NULL)
755 {
756 assert (l->l_type != lt_loaded);
757
758 if (l->l_info[DT_RUNPATH])
759 {
760 /* Allocate room for the search path and fill in information
761 from RUNPATH. */
762 decompose_rpath (&l->l_runpath_dirs,
763 (const void *) (D_PTR (l, l_info[DT_STRTAB])
764 + l->l_info[DT_RUNPATH]->d_un.d_val),
765 l, "RUNPATH");
766 /* During rtld init the memory is allocated by the stub malloc,
767 prevent any attempt to free it by the normal malloc. */
768 l->l_runpath_dirs.malloced = 0;
769
770 /* The RPATH is ignored. */
771 l->l_rpath_dirs.dirs = (void *) -1;
772 }
773 else
774 {
775 l->l_runpath_dirs.dirs = (void *) -1;
776
777 if (l->l_info[DT_RPATH])
778 {
779 /* Allocate room for the search path and fill in information
780 from RPATH. */
781 decompose_rpath (&l->l_rpath_dirs,
782 (const void *) (D_PTR (l, l_info[DT_STRTAB])
783 + l->l_info[DT_RPATH]->d_un.d_val),
784 l, "RPATH");
785 /* During rtld init the memory is allocated by the stub
786 malloc, prevent any attempt to free it by the normal
787 malloc. */
788 l->l_rpath_dirs.malloced = 0;
789 }
790 else
791 l->l_rpath_dirs.dirs = (void *) -1;
792 }
793 }
794#endif /* SHARED */
795
796 if (llp != NULL && *llp != '\0')
797 {
798 char *llp_tmp = strdupa (llp);
799
800 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
801 elements it has. */
802 size_t nllp = 1;
803 for (const char *cp = llp_tmp; *cp != '\0'; ++cp)
804 if (*cp == ':' || *cp == ';')
805 ++nllp;
806
807 env_path_list.dirs = (struct r_search_path_elem **)
808 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
809 if (env_path_list.dirs == NULL)
810 {
811 errstring = N_("cannot create cache for search path");
812 goto signal_error;
813 }
814
815 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
816 "LD_LIBRARY_PATH", NULL, l);
817
818 if (env_path_list.dirs[0] == NULL)
819 {
820 free (env_path_list.dirs);
821 env_path_list.dirs = (void *) -1;
822 }
823
824 env_path_list.malloced = 0;
825 }
826 else
827 env_path_list.dirs = (void *) -1;
828}
829
830
831static void
832__attribute__ ((noreturn, noinline))
833lose (int code, int fd, const char *name, char *realname, struct link_map *l,
834 const char *msg, struct r_debug *r, Lmid_t nsid)
835{
836 /* The file might already be closed. */
837 if (fd != -1)
838 (void) __close_nocancel (fd);
839 if (l != NULL && l->l_origin != (char *) -1l)
840 free ((char *) l->l_origin);
841 free (l);
842 free (realname);
843
844 if (r != NULL)
845 {
846 r->r_state = RT_CONSISTENT;
847 _dl_debug_state ();
848 LIBC_PROBE (map_failed, 2, nsid, r);
849 }
850
851 _dl_signal_error (code, name, NULL, msg);
852}
853
854
855/* Map in the shared object NAME, actually located in REALNAME, and already
856 opened on FD. */
857
858#ifndef EXTERNAL_MAP_FROM_FD
859static
860#endif
861struct link_map *
862_dl_map_object_from_fd (const char *name, const char *origname, int fd,
863 struct filebuf *fbp, char *realname,
864 struct link_map *loader, int l_type, int mode,
865 void **stack_endp, Lmid_t nsid)
866{
867 struct link_map *l = NULL;
868 const ElfW(Ehdr) *header;
869 const ElfW(Phdr) *phdr;
870 const ElfW(Phdr) *ph;
871 size_t maplength;
872 int type;
873 /* Initialize to keep the compiler happy. */
874 const char *errstring = NULL;
875 int errval = 0;
876 struct r_debug *r = _dl_debug_initialize (0, nsid);
877 bool make_consistent = false;
878
879 /* Get file information. */
880 struct r_file_id id;
881 if (__glibc_unlikely (!_dl_get_file_id (fd, &id)))
882 {
883 errstring = N_("cannot stat shared object");
884 call_lose_errno:
885 errval = errno;
886 call_lose:
887 lose (errval, fd, name, realname, l, errstring,
888 make_consistent ? r : NULL, nsid);
889 }
890
891 /* Look again to see if the real name matched another already loaded. */
892 for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
893 if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
894 {
895 /* The object is already loaded.
896 Just bump its reference count and return it. */
897 __close_nocancel (fd);
898
899 /* If the name is not in the list of names for this object add
900 it. */
901 free (realname);
902 add_name_to_object (l, name);
903
904 return l;
905 }
906
907#ifdef SHARED
908 /* When loading into a namespace other than the base one we must
909 avoid loading ld.so since there can only be one copy. Ever. */
910 if (__glibc_unlikely (nsid != LM_ID_BASE)
911 && (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
912 || _dl_name_match_p (name, &GL(dl_rtld_map))))
913 {
914 /* This is indeed ld.so. Create a new link_map which refers to
915 the real one for almost everything. */
916 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
917 if (l == NULL)
918 goto fail_new;
919
920 /* Refer to the real descriptor. */
921 l->l_real = &GL(dl_rtld_map);
922
923 /* No need to bump the refcount of the real object, ld.so will
924 never be unloaded. */
925 __close_nocancel (fd);
926
927 /* Add the map for the mirrored object to the object list. */
928 _dl_add_to_namespace_list (l, nsid);
929
930 return l;
931 }
932#endif
933
934 if (mode & RTLD_NOLOAD)
935 {
936 /* We are not supposed to load the object unless it is already
937 loaded. So return now. */
938 free (realname);
939 __close_nocancel (fd);
940 return NULL;
941 }
942
943 /* Print debugging message. */
944 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
945 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
946
947 /* This is the ELF header. We read it in `open_verify'. */
948 header = (void *) fbp->buf;
949
950 /* Signal that we are going to add new objects. */
951 if (r->r_state == RT_CONSISTENT)
952 {
953#ifdef SHARED
954 /* Auditing checkpoint: we are going to add new objects. */
955 if ((mode & __RTLD_AUDIT) == 0
956 && __glibc_unlikely (GLRO(dl_naudit) > 0))
957 {
958 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
959 /* Do not call the functions for any auditing object. */
960 if (head->l_auditing == 0)
961 {
962 struct audit_ifaces *afct = GLRO(dl_audit);
963 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
964 {
965 if (afct->activity != NULL)
966 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
967
968 afct = afct->next;
969 }
970 }
971 }
972#endif
973
974 /* Notify the debugger we have added some objects. We need to
975 call _dl_debug_initialize in a static program in case dynamic
976 linking has not been used before. */
977 r->r_state = RT_ADD;
978 _dl_debug_state ();
979 LIBC_PROBE (map_start, 2, nsid, r);
980 make_consistent = true;
981 }
982 else
983 assert (r->r_state == RT_ADD);
984
985 /* Enter the new object in the list of loaded objects. */
986 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
987 if (__glibc_unlikely (l == NULL))
988 {
989#ifdef SHARED
990 fail_new:
991#endif
992 errstring = N_("cannot create shared object descriptor");
993 goto call_lose_errno;
994 }
995
996 /* Extract the remaining details we need from the ELF header
997 and then read in the program header table. */
998 l->l_entry = header->e_entry;
999 type = header->e_type;
1000 l->l_phnum = header->e_phnum;
1001
1002 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1003 if (header->e_phoff + maplength <= (size_t) fbp->len)
1004 phdr = (void *) (fbp->buf + header->e_phoff);
1005 else
1006 {
1007 phdr = alloca (maplength);
1008 __lseek (fd, header->e_phoff, SEEK_SET);
1009 if ((size_t) __read_nocancel (fd, (void *) phdr, maplength) != maplength)
1010 {
1011 errstring = N_("cannot read file data");
1012 goto call_lose_errno;
1013 }
1014 }
1015
1016 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1017 * executable. Other platforms default to a nonexecutable stack and don't
1018 * need PT_GNU_STACK to do so. */
1019 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1020
1021 {
1022 /* Scan the program header table, collecting its load commands. */
1023 struct loadcmd loadcmds[l->l_phnum];
1024 size_t nloadcmds = 0;
1025 bool has_holes = false;
1026
1027 /* The struct is initialized to zero so this is not necessary:
1028 l->l_ld = 0;
1029 l->l_phdr = 0;
1030 l->l_addr = 0; */
1031 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1032 switch (ph->p_type)
1033 {
1034 /* These entries tell us where to find things once the file's
1035 segments are mapped in. We record the addresses it says
1036 verbatim, and later correct for the run-time load address. */
1037 case PT_DYNAMIC:
1038 if (ph->p_filesz)
1039 {
1040 /* Debuginfo only files from "objcopy --only-keep-debug"
1041 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1042 such a segment to avoid a crash later. */
1043 l->l_ld = (void *) ph->p_vaddr;
1044 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1045 }
1046 break;
1047
1048 case PT_PHDR:
1049 l->l_phdr = (void *) ph->p_vaddr;
1050 break;
1051
1052 case PT_LOAD:
1053 /* A load command tells us to map in part of the file.
1054 We record the load commands and process them all later. */
1055 if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0))
1056 {
1057 errstring = N_("ELF load command alignment not page-aligned");
1058 goto call_lose;
1059 }
1060 if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
1061 & (ph->p_align - 1)) != 0))
1062 {
1063 errstring
1064 = N_("ELF load command address/offset not properly aligned");
1065 goto call_lose;
1066 }
1067
1068 struct loadcmd *c = &loadcmds[nloadcmds++];
1069 c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
1070 c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
1071 c->dataend = ph->p_vaddr + ph->p_filesz;
1072 c->allocend = ph->p_vaddr + ph->p_memsz;
1073 c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
1074
1075 /* Determine whether there is a gap between the last segment
1076 and this one. */
1077 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1078 has_holes = true;
1079
1080 /* Optimize a common case. */
1081#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1082 c->prot = (PF_TO_PROT
1083 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1084#else
1085 c->prot = 0;
1086 if (ph->p_flags & PF_R)
1087 c->prot |= PROT_READ;
1088 if (ph->p_flags & PF_W)
1089 c->prot |= PROT_WRITE;
1090 if (ph->p_flags & PF_X)
1091 c->prot |= PROT_EXEC;
1092#endif
1093 break;
1094
1095 case PT_TLS:
1096 if (ph->p_memsz == 0)
1097 /* Nothing to do for an empty segment. */
1098 break;
1099
1100 l->l_tls_blocksize = ph->p_memsz;
1101 l->l_tls_align = ph->p_align;
1102 if (ph->p_align == 0)
1103 l->l_tls_firstbyte_offset = 0;
1104 else
1105 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1106 l->l_tls_initimage_size = ph->p_filesz;
1107 /* Since we don't know the load address yet only store the
1108 offset. We will adjust it later. */
1109 l->l_tls_initimage = (void *) ph->p_vaddr;
1110
1111 /* If not loading the initial set of shared libraries,
1112 check whether we should permit loading a TLS segment. */
1113 if (__glibc_likely (l->l_type == lt_library)
1114 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1115 not set up TLS data structures, so don't use them now. */
1116 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL))
1117 {
1118 /* Assign the next available module ID. */
1119 l->l_tls_modid = _dl_next_tls_modid ();
1120 break;
1121 }
1122
1123#ifdef SHARED
1124 /* We are loading the executable itself when the dynamic
1125 linker was executed directly. The setup will happen
1126 later. Otherwise, the TLS data structures are already
1127 initialized, and we assigned a TLS modid above. */
1128 assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
1129#else
1130 assert (false && "TLS not initialized in static application");
1131#endif
1132 break;
1133
1134 case PT_GNU_STACK:
1135 stack_flags = ph->p_flags;
1136 break;
1137
1138 case PT_GNU_RELRO:
1139 l->l_relro_addr = ph->p_vaddr;
1140 l->l_relro_size = ph->p_memsz;
1141 break;
1142
1143 case PT_NOTE:
1144 if (_dl_process_pt_note (l, ph, fd, fbp))
1145 {
1146 errstring = N_("cannot process note segment");
1147 goto call_lose;
1148 }
1149 break;
1150 }
1151
1152 if (__glibc_unlikely (nloadcmds == 0))
1153 {
1154 /* This only happens for a bogus object that will be caught with
1155 another error below. But we don't want to go through the
1156 calculations below using NLOADCMDS - 1. */
1157 errstring = N_("object file has no loadable segments");
1158 goto call_lose;
1159 }
1160
1161 if (__glibc_unlikely (type != ET_DYN)
1162 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
1163 {
1164 /* This object is loaded at a fixed address. This must never
1165 happen for objects loaded with dlopen. */
1166 errstring = N_("cannot dynamically load executable");
1167 goto call_lose;
1168 }
1169
1170 /* Length of the sections to be loaded. */
1171 maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
1172
1173 /* Now process the load commands and map segments into memory.
1174 This is responsible for filling in:
1175 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1176 */
1177 errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
1178 maplength, has_holes, loader);
1179 if (__glibc_unlikely (errstring != NULL))
1180 goto call_lose;
1181 }
1182
1183 if (l->l_ld == 0)
1184 {
1185 if (__glibc_unlikely (type == ET_DYN))
1186 {
1187 errstring = N_("object file has no dynamic section");
1188 goto call_lose;
1189 }
1190 }
1191 else
1192 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1193
1194 elf_get_dynamic_info (l, NULL);
1195
1196 /* Make sure we are not dlopen'ing an object that has the
1197 DF_1_NOOPEN flag set. */
1198 if (__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1199 && (mode & __RTLD_DLOPEN))
1200 {
1201 /* We are not supposed to load this object. Free all resources. */
1202 _dl_unmap_segments (l);
1203
1204 if (!l->l_libname->dont_free)
1205 free (l->l_libname);
1206
1207 if (l->l_phdr_allocated)
1208 free ((void *) l->l_phdr);
1209
1210 errstring = N_("shared object cannot be dlopen()ed");
1211 goto call_lose;
1212 }
1213
1214 if (l->l_phdr == NULL)
1215 {
1216 /* The program header is not contained in any of the segments.
1217 We have to allocate memory ourself and copy it over from out
1218 temporary place. */
1219 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1220 * sizeof (ElfW(Phdr)));
1221 if (newp == NULL)
1222 {
1223 errstring = N_("cannot allocate memory for program header");
1224 goto call_lose_errno;
1225 }
1226
1227 l->l_phdr = memcpy (newp, phdr,
1228 (header->e_phnum * sizeof (ElfW(Phdr))));
1229 l->l_phdr_allocated = 1;
1230 }
1231 else
1232 /* Adjust the PT_PHDR value by the runtime load address. */
1233 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1234
1235 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
1236 {
1237 /* The stack is presently not executable, but this module
1238 requires that it be executable. We must change the
1239 protection of the variable which contains the flags used in
1240 the mprotect calls. */
1241#ifdef SHARED
1242 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1243 {
1244 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1245 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1246
1247 struct link_map *const m = &GL(dl_rtld_map);
1248 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1249 + m->l_relro_size)
1250 & -GLRO(dl_pagesize));
1251 if (__glibc_likely (p + s <= relro_end))
1252 {
1253 /* The variable lies in the region protected by RELRO. */
1254 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1255 {
1256 errstring = N_("cannot change memory protections");
1257 goto call_lose_errno;
1258 }
1259 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1260 __mprotect ((void *) p, s, PROT_READ);
1261 }
1262 else
1263 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1264 }
1265 else
1266#endif
1267 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1268
1269#ifdef check_consistency
1270 check_consistency ();
1271#endif
1272
1273 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1274 if (errval)
1275 {
1276 errstring = N_("\
1277cannot enable executable stack as shared object requires");
1278 goto call_lose;
1279 }
1280 }
1281
1282 /* Adjust the address of the TLS initialization image. */
1283 if (l->l_tls_initimage != NULL)
1284 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1285
1286 /* We are done mapping in the file. We no longer need the descriptor. */
1287 if (__glibc_unlikely (__close_nocancel (fd) != 0))
1288 {
1289 errstring = N_("cannot close file descriptor");
1290 goto call_lose_errno;
1291 }
1292 /* Signal that we closed the file. */
1293 fd = -1;
1294
1295 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1296 assert (type != ET_EXEC || l->l_type == lt_executable);
1297
1298 l->l_entry += l->l_addr;
1299
1300 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1301 _dl_debug_printf ("\
1302 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1303 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1304 (int) sizeof (void *) * 2,
1305 (unsigned long int) l->l_ld,
1306 (int) sizeof (void *) * 2,
1307 (unsigned long int) l->l_addr,
1308 (int) sizeof (void *) * 2, maplength,
1309 (int) sizeof (void *) * 2,
1310 (unsigned long int) l->l_entry,
1311 (int) sizeof (void *) * 2,
1312 (unsigned long int) l->l_phdr,
1313 (int) sizeof (void *) * 2, l->l_phnum);
1314
1315 /* Set up the symbol hash table. */
1316 _dl_setup_hash (l);
1317
1318 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1319 have to do this for the main map. */
1320 if ((mode & RTLD_DEEPBIND) == 0
1321 && __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
1322 && &l->l_searchlist != l->l_scope[0])
1323 {
1324 /* Create an appropriate searchlist. It contains only this map.
1325 This is the definition of DT_SYMBOLIC in SysVr4. */
1326 l->l_symbolic_searchlist.r_list[0] = l;
1327 l->l_symbolic_searchlist.r_nlist = 1;
1328
1329 /* Now move the existing entries one back. */
1330 memmove (&l->l_scope[1], &l->l_scope[0],
1331 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1332
1333 /* Now add the new entry. */
1334 l->l_scope[0] = &l->l_symbolic_searchlist;
1335 }
1336
1337 /* Remember whether this object must be initialized first. */
1338 if (l->l_flags_1 & DF_1_INITFIRST)
1339 GL(dl_initfirst) = l;
1340
1341 /* Finally the file information. */
1342 l->l_file_id = id;
1343
1344#ifdef SHARED
1345 /* When auditing is used the recorded names might not include the
1346 name by which the DSO is actually known. Add that as well. */
1347 if (__glibc_unlikely (origname != NULL))
1348 add_name_to_object (l, origname);
1349#else
1350 /* Audit modules only exist when linking is dynamic so ORIGNAME
1351 cannot be non-NULL. */
1352 assert (origname == NULL);
1353#endif
1354
1355 /* When we profile the SONAME might be needed for something else but
1356 loading. Add it right away. */
1357 if (__glibc_unlikely (GLRO(dl_profile) != NULL)
1358 && l->l_info[DT_SONAME] != NULL)
1359 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1360 + l->l_info[DT_SONAME]->d_un.d_val));
1361
1362#ifdef DL_AFTER_LOAD
1363 DL_AFTER_LOAD (l);
1364#endif
1365
1366 /* Now that the object is fully initialized add it to the object list. */
1367 _dl_add_to_namespace_list (l, nsid);
1368
1369#ifdef SHARED
1370 /* Auditing checkpoint: we have a new object. */
1371 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1372 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1373 {
1374 struct audit_ifaces *afct = GLRO(dl_audit);
1375 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1376 {
1377 if (afct->objopen != NULL)
1378 {
1379 l->l_audit[cnt].bindflags
1380 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1381
1382 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1383 }
1384
1385 afct = afct->next;
1386 }
1387 }
1388#endif
1389
1390 return l;
1391}
1392
1393/* Print search path. */
1394static void
1395print_search_path (struct r_search_path_elem **list,
1396 const char *what, const char *name)
1397{
1398 char buf[max_dirnamelen + max_capstrlen];
1399 int first = 1;
1400
1401 _dl_debug_printf (" search path=");
1402
1403 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1404 {
1405 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1406 size_t cnt;
1407
1408 for (cnt = 0; cnt < ncapstr; ++cnt)
1409 if ((*list)->status[cnt] != nonexisting)
1410 {
1411 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1412 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1413 cp[0] = '\0';
1414 else
1415 cp[-1] = '\0';
1416
1417 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1418 first = 0;
1419 }
1420
1421 ++list;
1422 }
1423
1424 if (name != NULL)
1425 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1426 DSO_FILENAME (name));
1427 else
1428 _dl_debug_printf_c ("\t\t(%s)\n", what);
1429}
1430
1431/* Open a file and verify it is an ELF file for this architecture. We
1432 ignore only ELF files for other architectures. Non-ELF files and
1433 ELF files with different header information cause fatal errors since
1434 this could mean there is something wrong in the installation and the
1435 user might want to know about this.
1436
1437 If FD is not -1, then the file is already open and FD refers to it.
1438 In that case, FD is consumed for both successful and error returns. */
1439static int
1440open_verify (const char *name, int fd,
1441 struct filebuf *fbp, struct link_map *loader,
1442 int whatcode, int mode, bool *found_other_class, bool free_name)
1443{
1444 /* This is the expected ELF header. */
1445#define ELF32_CLASS ELFCLASS32
1446#define ELF64_CLASS ELFCLASS64
1447#ifndef VALID_ELF_HEADER
1448# define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1449# define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1450# define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1451#elif defined MORE_ELF_HEADER_DATA
1452 MORE_ELF_HEADER_DATA;
1453#endif
1454 static const unsigned char expected[EI_NIDENT] =
1455 {
1456 [EI_MAG0] = ELFMAG0,
1457 [EI_MAG1] = ELFMAG1,
1458 [EI_MAG2] = ELFMAG2,
1459 [EI_MAG3] = ELFMAG3,
1460 [EI_CLASS] = ELFW(CLASS),
1461 [EI_DATA] = byteorder,
1462 [EI_VERSION] = EV_CURRENT,
1463 [EI_OSABI] = ELFOSABI_SYSV,
1464 [EI_ABIVERSION] = 0
1465 };
1466 static const struct
1467 {
1468 ElfW(Word) vendorlen;
1469 ElfW(Word) datalen;
1470 ElfW(Word) type;
1471 char vendor[4];
1472 } expected_note = { 4, 16, 1, "GNU" };
1473 /* Initialize it to make the compiler happy. */
1474 const char *errstring = NULL;
1475 int errval = 0;
1476
1477#ifdef SHARED
1478 /* Give the auditing libraries a chance. */
1479 if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
1480 && loader->l_auditing == 0)
1481 {
1482 const char *original_name = name;
1483 struct audit_ifaces *afct = GLRO(dl_audit);
1484 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1485 {
1486 if (afct->objsearch != NULL)
1487 {
1488 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1489 whatcode);
1490 if (name == NULL)
1491 /* Ignore the path. */
1492 return -1;
1493 }
1494
1495 afct = afct->next;
1496 }
1497
1498 if (fd != -1 && name != original_name && strcmp (name, original_name))
1499 {
1500 /* An audit library changed what we're supposed to open,
1501 so FD no longer matches it. */
1502 __close_nocancel (fd);
1503 fd = -1;
1504 }
1505 }
1506#endif
1507
1508 if (fd == -1)
1509 /* Open the file. We always open files read-only. */
1510 fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
1511
1512 if (fd != -1)
1513 {
1514 ElfW(Ehdr) *ehdr;
1515 ElfW(Phdr) *phdr, *ph;
1516 ElfW(Word) *abi_note;
1517 ElfW(Word) *abi_note_malloced = NULL;
1518 unsigned int osversion;
1519 size_t maplength;
1520
1521 /* We successfully opened the file. Now verify it is a file
1522 we can use. */
1523 __set_errno (0);
1524 fbp->len = 0;
1525 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1526 /* Read in the header. */
1527 do
1528 {
1529 ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
1530 sizeof (fbp->buf) - fbp->len);
1531 if (retlen <= 0)
1532 break;
1533 fbp->len += retlen;
1534 }
1535 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1536
1537 /* This is where the ELF header is loaded. */
1538 ehdr = (ElfW(Ehdr) *) fbp->buf;
1539
1540 /* Now run the tests. */
1541 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1542 {
1543 errval = errno;
1544 errstring = (errval == 0
1545 ? N_("file too short") : N_("cannot read file data"));
1546 call_lose:
1547 if (free_name)
1548 {
1549 char *realname = (char *) name;
1550 name = strdupa (realname);
1551 free (realname);
1552 }
1553 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1554 }
1555
1556 /* See whether the ELF header is what we expect. */
1557 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1558 EI_ABIVERSION)
1559 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1560 ehdr->e_ident[EI_ABIVERSION])
1561 || memcmp (&ehdr->e_ident[EI_PAD],
1562 &expected[EI_PAD],
1563 EI_NIDENT - EI_PAD) != 0))
1564 {
1565 /* Something is wrong. */
1566 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1567 if (*magp !=
1568#if BYTE_ORDER == LITTLE_ENDIAN
1569 ((ELFMAG0 << (EI_MAG0 * 8))
1570 | (ELFMAG1 << (EI_MAG1 * 8))
1571 | (ELFMAG2 << (EI_MAG2 * 8))
1572 | (ELFMAG3 << (EI_MAG3 * 8)))
1573#else
1574 ((ELFMAG0 << (EI_MAG3 * 8))
1575 | (ELFMAG1 << (EI_MAG2 * 8))
1576 | (ELFMAG2 << (EI_MAG1 * 8))
1577 | (ELFMAG3 << (EI_MAG0 * 8)))
1578#endif
1579 )
1580 errstring = N_("invalid ELF header");
1581 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1582 {
1583 /* This is not a fatal error. On architectures where
1584 32-bit and 64-bit binaries can be run this might
1585 happen. */
1586 *found_other_class = true;
1587 goto close_and_out;
1588 }
1589 else if (ehdr->e_ident[EI_DATA] != byteorder)
1590 {
1591 if (BYTE_ORDER == BIG_ENDIAN)
1592 errstring = N_("ELF file data encoding not big-endian");
1593 else
1594 errstring = N_("ELF file data encoding not little-endian");
1595 }
1596 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1597 errstring
1598 = N_("ELF file version ident does not match current one");
1599 /* XXX We should be able so set system specific versions which are
1600 allowed here. */
1601 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1602 errstring = N_("ELF file OS ABI invalid");
1603 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1604 ehdr->e_ident[EI_ABIVERSION]))
1605 errstring = N_("ELF file ABI version invalid");
1606 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1607 EI_NIDENT - EI_PAD) != 0)
1608 errstring = N_("nonzero padding in e_ident");
1609 else
1610 /* Otherwise we don't know what went wrong. */
1611 errstring = N_("internal error");
1612
1613 goto call_lose;
1614 }
1615
1616 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1617 {
1618 errstring = N_("ELF file version does not match current one");
1619 goto call_lose;
1620 }
1621 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1622 goto close_and_out;
1623 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1624 && ehdr->e_type != ET_EXEC))
1625 {
1626 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1627 goto call_lose;
1628 }
1629 else if (__glibc_unlikely (ehdr->e_type == ET_EXEC
1630 && (mode & __RTLD_OPENEXEC) == 0))
1631 {
1632 /* BZ #16634. It is an error to dlopen ET_EXEC (unless
1633 __RTLD_OPENEXEC is explicitly set). We return error here
1634 so that code in _dl_map_object_from_fd does not try to set
1635 l_tls_modid for this module. */
1636
1637 errstring = N_("cannot dynamically load executable");
1638 goto call_lose;
1639 }
1640 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1641 {
1642 errstring = N_("ELF file's phentsize not the expected size");
1643 goto call_lose;
1644 }
1645
1646 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1647 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1648 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1649 else
1650 {
1651 phdr = alloca (maplength);
1652 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1653 if ((size_t) __read_nocancel (fd, (void *) phdr, maplength)
1654 != maplength)
1655 {
1656 read_error:
1657 errval = errno;
1658 errstring = N_("cannot read file data");
1659 goto call_lose;
1660 }
1661 }
1662
1663 if (__glibc_unlikely (elf_machine_reject_phdr_p
1664 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1665 loader, fd)))
1666 goto close_and_out;
1667
1668 /* Check .note.ABI-tag if present. */
1669 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1670 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1671 {
1672 ElfW(Addr) size = ph->p_filesz;
1673 /* NB: Some PT_NOTE segment may have alignment value of 0
1674 or 1. gABI specifies that PT_NOTE segments should be
1675 aligned to 4 bytes in 32-bit objects and to 8 bytes in
1676 64-bit objects. As a Linux extension, we also support
1677 4 byte alignment in 64-bit objects. If p_align is less
1678 than 4, we treate alignment as 4 bytes since some note
1679 segments have 0 or 1 byte alignment. */
1680 ElfW(Addr) align = ph->p_align;
1681 if (align < 4)
1682 align = 4;
1683 else if (align != 4 && align != 8)
1684 continue;
1685
1686 if (ph->p_offset + size <= (size_t) fbp->len)
1687 abi_note = (void *) (fbp->buf + ph->p_offset);
1688 else
1689 {
1690 /* Note: __libc_use_alloca is not usable here, because
1691 thread info may not have been set up yet. */
1692 if (size < __MAX_ALLOCA_CUTOFF)
1693 abi_note = alloca (size);
1694 else
1695 {
1696 /* There could be multiple PT_NOTEs. */
1697 abi_note_malloced = realloc (abi_note_malloced, size);
1698 if (abi_note_malloced == NULL)
1699 goto read_error;
1700
1701 abi_note = abi_note_malloced;
1702 }
1703 __lseek (fd, ph->p_offset, SEEK_SET);
1704 if (__read_nocancel (fd, (void *) abi_note, size) != size)
1705 {
1706 free (abi_note_malloced);
1707 goto read_error;
1708 }
1709 }
1710
1711 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1712 {
1713 ElfW(Addr) note_size
1714 = ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
1715 align);
1716
1717 if (size - 32 < note_size)
1718 {
1719 size = 0;
1720 break;
1721 }
1722 size -= note_size;
1723 abi_note = (void *) abi_note + note_size;
1724 }
1725
1726 if (size == 0)
1727 continue;
1728
1729 osversion = (abi_note[5] & 0xff) * 65536
1730 + (abi_note[6] & 0xff) * 256
1731 + (abi_note[7] & 0xff);
1732 if (abi_note[4] != __ABI_TAG_OS
1733 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1734 {
1735 close_and_out:
1736 __close_nocancel (fd);
1737 __set_errno (ENOENT);
1738 fd = -1;
1739 }
1740
1741 break;
1742 }
1743 free (abi_note_malloced);
1744 }
1745
1746 return fd;
1747}
1748
1749/* Try to open NAME in one of the directories in *DIRSP.
1750 Return the fd, or -1. If successful, fill in *REALNAME
1751 with the malloc'd full directory name. If it turns out
1752 that none of the directories in *DIRSP exists, *DIRSP is
1753 replaced with (void *) -1, and the old value is free()d
1754 if MAY_FREE_DIRS is true. */
1755
1756static int
1757open_path (const char *name, size_t namelen, int mode,
1758 struct r_search_path_struct *sps, char **realname,
1759 struct filebuf *fbp, struct link_map *loader, int whatcode,
1760 bool *found_other_class)
1761{
1762 struct r_search_path_elem **dirs = sps->dirs;
1763 char *buf;
1764 int fd = -1;
1765 const char *current_what = NULL;
1766 int any = 0;
1767
1768 if (__glibc_unlikely (dirs == NULL))
1769 /* We're called before _dl_init_paths when loading the main executable
1770 given on the command line when rtld is run directly. */
1771 return -1;
1772
1773 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1774 do
1775 {
1776 struct r_search_path_elem *this_dir = *dirs;
1777 size_t buflen = 0;
1778 size_t cnt;
1779 char *edp;
1780 int here_any = 0;
1781 int err;
1782
1783 /* If we are debugging the search for libraries print the path
1784 now if it hasn't happened now. */
1785 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1786 && current_what != this_dir->what)
1787 {
1788 current_what = this_dir->what;
1789 print_search_path (dirs, current_what, this_dir->where);
1790 }
1791
1792 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1793 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1794 {
1795 /* Skip this directory if we know it does not exist. */
1796 if (this_dir->status[cnt] == nonexisting)
1797 continue;
1798
1799 buflen =
1800 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1801 capstr[cnt].len),
1802 name, namelen)
1803 - buf);
1804
1805 /* Print name we try if this is wanted. */
1806 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1807 _dl_debug_printf (" trying file=%s\n", buf);
1808
1809 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1810 found_other_class, false);
1811 if (this_dir->status[cnt] == unknown)
1812 {
1813 if (fd != -1)
1814 this_dir->status[cnt] = existing;
1815 /* Do not update the directory information when loading
1816 auditing code. We must try to disturb the program as
1817 little as possible. */
1818 else if (loader == NULL
1819 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1820 {
1821 /* We failed to open machine dependent library. Let's
1822 test whether there is any directory at all. */
1823 struct stat64 st;
1824
1825 buf[buflen - namelen - 1] = '\0';
1826
1827 if (__xstat64 (_STAT_VER, buf, &st) != 0
1828 || ! S_ISDIR (st.st_mode))
1829 /* The directory does not exist or it is no directory. */
1830 this_dir->status[cnt] = nonexisting;
1831 else
1832 this_dir->status[cnt] = existing;
1833 }
1834 }
1835
1836 /* Remember whether we found any existing directory. */
1837 here_any |= this_dir->status[cnt] != nonexisting;
1838
1839 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1840 && __libc_enable_secure)
1841 {
1842 /* This is an extra security effort to make sure nobody can
1843 preload broken shared objects which are in the trusted
1844 directories and so exploit the bugs. */
1845 struct stat64 st;
1846
1847 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1848 || (st.st_mode & S_ISUID) == 0)
1849 {
1850 /* The shared object cannot be tested for being SUID
1851 or this bit is not set. In this case we must not
1852 use this object. */
1853 __close_nocancel (fd);
1854 fd = -1;
1855 /* We simply ignore the file, signal this by setting
1856 the error value which would have been set by `open'. */
1857 errno = ENOENT;
1858 }
1859 }
1860 }
1861
1862 if (fd != -1)
1863 {
1864 *realname = (char *) malloc (buflen);
1865 if (*realname != NULL)
1866 {
1867 memcpy (*realname, buf, buflen);
1868 return fd;
1869 }
1870 else
1871 {
1872 /* No memory for the name, we certainly won't be able
1873 to load and link it. */
1874 __close_nocancel (fd);
1875 return -1;
1876 }
1877 }
1878 if (here_any && (err = errno) != ENOENT && err != EACCES)
1879 /* The file exists and is readable, but something went wrong. */
1880 return -1;
1881
1882 /* Remember whether we found anything. */
1883 any |= here_any;
1884 }
1885 while (*++dirs != NULL);
1886
1887 /* Remove the whole path if none of the directories exists. */
1888 if (__glibc_unlikely (! any))
1889 {
1890 /* Paths which were allocated using the minimal malloc() in ld.so
1891 must not be freed using the general free() in libc. */
1892 if (sps->malloced)
1893 free (sps->dirs);
1894
1895 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1896 avoid writing into it. */
1897 if (sps != &rtld_search_dirs && sps != &env_path_list)
1898 sps->dirs = (void *) -1;
1899 }
1900
1901 return -1;
1902}
1903
1904/* Map in the shared object file NAME. */
1905
1906struct link_map *
1907_dl_map_object (struct link_map *loader, const char *name,
1908 int type, int trace_mode, int mode, Lmid_t nsid)
1909{
1910 int fd;
1911 const char *origname = NULL;
1912 char *realname;
1913 char *name_copy;
1914 struct link_map *l;
1915 struct filebuf fb;
1916
1917 assert (nsid >= 0);
1918 assert (nsid < GL(dl_nns));
1919
1920 /* Look for this name among those already loaded. */
1921 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1922 {
1923 /* If the requested name matches the soname of a loaded object,
1924 use that object. Elide this check for names that have not
1925 yet been opened. */
1926 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
1927 continue;
1928 if (!_dl_name_match_p (name, l))
1929 {
1930 const char *soname;
1931
1932 if (__glibc_likely (l->l_soname_added)
1933 || l->l_info[DT_SONAME] == NULL)
1934 continue;
1935
1936 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1937 + l->l_info[DT_SONAME]->d_un.d_val);
1938 if (strcmp (name, soname) != 0)
1939 continue;
1940
1941 /* We have a match on a new name -- cache it. */
1942 add_name_to_object (l, soname);
1943 l->l_soname_added = 1;
1944 }
1945
1946 /* We have a match. */
1947 return l;
1948 }
1949
1950 /* Display information if we are debugging. */
1951 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1952 && loader != NULL)
1953 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
1954 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1955 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1956 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
1957
1958#ifdef SHARED
1959 /* Give the auditing libraries a chance to change the name before we
1960 try anything. */
1961 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1962 && (loader == NULL || loader->l_auditing == 0))
1963 {
1964 struct audit_ifaces *afct = GLRO(dl_audit);
1965 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1966 {
1967 if (afct->objsearch != NULL)
1968 {
1969 const char *before = name;
1970 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1971 LA_SER_ORIG);
1972 if (name == NULL)
1973 {
1974 /* Do not try anything further. */
1975 fd = -1;
1976 goto no_file;
1977 }
1978 if (before != name && strcmp (before, name) != 0)
1979 {
1980 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1981 _dl_debug_printf ("audit changed filename %s -> %s\n",
1982 before, name);
1983
1984 if (origname == NULL)
1985 origname = before;
1986 }
1987 }
1988
1989 afct = afct->next;
1990 }
1991 }
1992#endif
1993
1994 /* Will be true if we found a DSO which is of the other ELF class. */
1995 bool found_other_class = false;
1996
1997 if (strchr (name, '/') == NULL)
1998 {
1999 /* Search for NAME in several places. */
2000
2001 size_t namelen = strlen (name) + 1;
2002
2003 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2004 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2005
2006 fd = -1;
2007
2008 /* When the object has the RUNPATH information we don't use any
2009 RPATHs. */
2010 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2011 {
2012 /* This is the executable's map (if there is one). Make sure that
2013 we do not look at it twice. */
2014 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2015 bool did_main_map = false;
2016
2017 /* First try the DT_RPATH of the dependent object that caused NAME
2018 to be loaded. Then that object's dependent, and on up. */
2019 for (l = loader; l; l = l->l_loader)
2020 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2021 {
2022 fd = open_path (name, namelen, mode,
2023 &l->l_rpath_dirs,
2024 &realname, &fb, loader, LA_SER_RUNPATH,
2025 &found_other_class);
2026 if (fd != -1)
2027 break;
2028
2029 did_main_map |= l == main_map;
2030 }
2031
2032 /* If dynamically linked, try the DT_RPATH of the executable
2033 itself. NB: we do this for lookups in any namespace. */
2034 if (fd == -1 && !did_main_map
2035 && main_map != NULL && main_map->l_type != lt_loaded
2036 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2037 "RPATH"))
2038 fd = open_path (name, namelen, mode,
2039 &main_map->l_rpath_dirs,
2040 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2041 &found_other_class);
2042 }
2043
2044 /* Try the LD_LIBRARY_PATH environment variable. */
2045 if (fd == -1 && env_path_list.dirs != (void *) -1)
2046 fd = open_path (name, namelen, mode, &env_path_list,
2047 &realname, &fb,
2048 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2049 LA_SER_LIBPATH, &found_other_class);
2050
2051 /* Look at the RUNPATH information for this binary. */
2052 if (fd == -1 && loader != NULL
2053 && cache_rpath (loader, &loader->l_runpath_dirs,
2054 DT_RUNPATH, "RUNPATH"))
2055 fd = open_path (name, namelen, mode,
2056 &loader->l_runpath_dirs, &realname, &fb, loader,
2057 LA_SER_RUNPATH, &found_other_class);
2058
2059 if (fd == -1)
2060 {
2061 realname = _dl_sysdep_open_object (name, namelen, &fd);
2062 if (realname != NULL)
2063 {
2064 fd = open_verify (realname, fd,
2065 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2066 LA_SER_CONFIG, mode, &found_other_class,
2067 false);
2068 if (fd == -1)
2069 free (realname);
2070 }
2071 }
2072
2073#ifdef USE_LDCONFIG
2074 if (fd == -1
2075 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2076 || ! __libc_enable_secure)
2077 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2078 {
2079 /* Check the list of libraries in the file /etc/ld.so.cache,
2080 for compatibility with Linux's ldconfig program. */
2081 char *cached = _dl_load_cache_lookup (name);
2082
2083 if (cached != NULL)
2084 {
2085 // XXX Correct to unconditionally default to namespace 0?
2086 l = (loader
2087 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2088# ifdef SHARED
2089 ?: &GL(dl_rtld_map)
2090# endif
2091 );
2092
2093 /* If the loader has the DF_1_NODEFLIB flag set we must not
2094 use a cache entry from any of these directories. */
2095 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2096 {
2097 const char *dirp = system_dirs;
2098 unsigned int cnt = 0;
2099
2100 do
2101 {
2102 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2103 {
2104 /* The prefix matches. Don't use the entry. */
2105 free (cached);
2106 cached = NULL;
2107 break;
2108 }
2109
2110 dirp += system_dirs_len[cnt] + 1;
2111 ++cnt;
2112 }
2113 while (cnt < nsystem_dirs_len);
2114 }
2115
2116 if (cached != NULL)
2117 {
2118 fd = open_verify (cached, -1,
2119 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2120 LA_SER_CONFIG, mode, &found_other_class,
2121 false);
2122 if (__glibc_likely (fd != -1))
2123 realname = cached;
2124 else
2125 free (cached);
2126 }
2127 }
2128 }
2129#endif
2130
2131 /* Finally, try the default path. */
2132 if (fd == -1
2133 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2134 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2135 && rtld_search_dirs.dirs != (void *) -1)
2136 fd = open_path (name, namelen, mode, &rtld_search_dirs,
2137 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2138
2139 /* Add another newline when we are tracing the library loading. */
2140 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2141 _dl_debug_printf ("\n");
2142 }
2143 else
2144 {
2145 /* The path may contain dynamic string tokens. */
2146 realname = (loader
2147 ? expand_dynamic_string_token (loader, name)
2148 : __strdup (name));
2149 if (realname == NULL)
2150 fd = -1;
2151 else
2152 {
2153 fd = open_verify (realname, -1, &fb,
2154 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2155 &found_other_class, true);
2156 if (__glibc_unlikely (fd == -1))
2157 free (realname);
2158 }
2159 }
2160
2161#ifdef SHARED
2162 no_file:
2163#endif
2164 /* In case the LOADER information has only been provided to get to
2165 the appropriate RUNPATH/RPATH information we do not need it
2166 anymore. */
2167 if (mode & __RTLD_CALLMAP)
2168 loader = NULL;
2169
2170 if (__glibc_unlikely (fd == -1))
2171 {
2172 if (trace_mode
2173 && __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
2174 {
2175 /* We haven't found an appropriate library. But since we
2176 are only interested in the list of libraries this isn't
2177 so severe. Fake an entry with all the information we
2178 have. */
2179 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2180
2181 /* Allocate a new object map. */
2182 if ((name_copy = __strdup (name)) == NULL
2183 || (l = _dl_new_object (name_copy, name, type, loader,
2184 mode, nsid)) == NULL)
2185 {
2186 free (name_copy);
2187 _dl_signal_error (ENOMEM, name, NULL,
2188 N_("cannot create shared object descriptor"));
2189 }
2190 /* Signal that this is a faked entry. */
2191 l->l_faked = 1;
2192 /* Since the descriptor is initialized with zero we do not
2193 have do this here.
2194 l->l_reserved = 0; */
2195 l->l_buckets = &dummy_bucket;
2196 l->l_nbuckets = 1;
2197 l->l_relocated = 1;
2198
2199 /* Enter the object in the object list. */
2200 _dl_add_to_namespace_list (l, nsid);
2201
2202 return l;
2203 }
2204 else if (found_other_class)
2205 _dl_signal_error (0, name, NULL,
2206 ELFW(CLASS) == ELFCLASS32
2207 ? N_("wrong ELF class: ELFCLASS64")
2208 : N_("wrong ELF class: ELFCLASS32"));
2209 else
2210 _dl_signal_error (errno, name, NULL,
2211 N_("cannot open shared object file"));
2212 }
2213
2214 void *stack_end = __libc_stack_end;
2215 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2216 type, mode, &stack_end, nsid);
2217}
2218
2219struct add_path_state
2220{
2221 bool counting;
2222 unsigned int idx;
2223 Dl_serinfo *si;
2224 char *allocptr;
2225};
2226
2227static void
2228add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2229 unsigned int flags)
2230{
2231 if (sps->dirs != (void *) -1)
2232 {
2233 struct r_search_path_elem **dirs = sps->dirs;
2234 do
2235 {
2236 const struct r_search_path_elem *const r = *dirs++;
2237 if (p->counting)
2238 {
2239 p->si->dls_cnt++;
2240 p->si->dls_size += MAX (2, r->dirnamelen);
2241 }
2242 else
2243 {
2244 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2245 sp->dls_name = p->allocptr;
2246 if (r->dirnamelen < 2)
2247 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2248 else
2249 p->allocptr = __mempcpy (p->allocptr,
2250 r->dirname, r->dirnamelen - 1);
2251 *p->allocptr++ = '\0';
2252 sp->dls_flags = flags;
2253 }
2254 }
2255 while (*dirs != NULL);
2256 }
2257}
2258
2259void
2260_dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2261{
2262 if (counting)
2263 {
2264 si->dls_cnt = 0;
2265 si->dls_size = 0;
2266 }
2267
2268 struct add_path_state p =
2269 {
2270 .counting = counting,
2271 .idx = 0,
2272 .si = si,
2273 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2274 };
2275
2276# define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2277
2278 /* When the object has the RUNPATH information we don't use any RPATHs. */
2279 if (loader->l_info[DT_RUNPATH] == NULL)
2280 {
2281 /* First try the DT_RPATH of the dependent object that caused NAME
2282 to be loaded. Then that object's dependent, and on up. */
2283
2284 struct link_map *l = loader;
2285 do
2286 {
2287 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2288 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2289 l = l->l_loader;
2290 }
2291 while (l != NULL);
2292
2293 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2294 if (loader->l_ns == LM_ID_BASE)
2295 {
2296 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2297 if (l != NULL && l->l_type != lt_loaded && l != loader)
2298 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2299 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2300 }
2301 }
2302
2303 /* Try the LD_LIBRARY_PATH environment variable. */
2304 add_path (&p, &env_path_list, XXX_ENV);
2305
2306 /* Look at the RUNPATH information for this binary. */
2307 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2308 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2309
2310 /* XXX
2311 Here is where ld.so.cache gets checked, but we don't have
2312 a way to indicate that in the results for Dl_serinfo. */
2313
2314 /* Finally, try the default path. */
2315 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2316 add_path (&p, &rtld_search_dirs, XXX_default);
2317
2318 if (counting)
2319 /* Count the struct size before the string area, which we didn't
2320 know before we completed dls_cnt. */
2321 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;
2322}
2323