1/* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2020 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 <https://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. To match the kernel behavior, do not fill
880 in this information for the executable in case of an explicit
881 loader invocation. */
882 struct r_file_id id;
883 if (mode & __RTLD_OPENEXEC)
884 {
885 assert (nsid == LM_ID_BASE);
886 memset (&id, 0, sizeof (id));
887 }
888 else
889 {
890 if (__glibc_unlikely (!_dl_get_file_id (fd, &id)))
891 {
892 errstring = N_("cannot stat shared object");
893 call_lose_errno:
894 errval = errno;
895 call_lose:
896 lose (errval, fd, name, realname, l, errstring,
897 make_consistent ? r : NULL, nsid);
898 }
899
900 /* Look again to see if the real name matched another already loaded. */
901 for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
902 if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
903 {
904 /* The object is already loaded.
905 Just bump its reference count and return it. */
906 __close_nocancel (fd);
907
908 /* If the name is not in the list of names for this object add
909 it. */
910 free (realname);
911 add_name_to_object (l, name);
912
913 return l;
914 }
915 }
916
917#ifdef SHARED
918 /* When loading into a namespace other than the base one we must
919 avoid loading ld.so since there can only be one copy. Ever. */
920 if (__glibc_unlikely (nsid != LM_ID_BASE)
921 && (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
922 || _dl_name_match_p (name, &GL(dl_rtld_map))))
923 {
924 /* This is indeed ld.so. Create a new link_map which refers to
925 the real one for almost everything. */
926 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
927 if (l == NULL)
928 goto fail_new;
929
930 /* Refer to the real descriptor. */
931 l->l_real = &GL(dl_rtld_map);
932
933 /* No need to bump the refcount of the real object, ld.so will
934 never be unloaded. */
935 __close_nocancel (fd);
936
937 /* Add the map for the mirrored object to the object list. */
938 _dl_add_to_namespace_list (l, nsid);
939
940 return l;
941 }
942#endif
943
944 if (mode & RTLD_NOLOAD)
945 {
946 /* We are not supposed to load the object unless it is already
947 loaded. So return now. */
948 free (realname);
949 __close_nocancel (fd);
950 return NULL;
951 }
952
953 /* Print debugging message. */
954 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
955 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
956
957 /* This is the ELF header. We read it in `open_verify'. */
958 header = (void *) fbp->buf;
959
960 /* Signal that we are going to add new objects. */
961 if (r->r_state == RT_CONSISTENT)
962 {
963#ifdef SHARED
964 /* Auditing checkpoint: we are going to add new objects. */
965 if ((mode & __RTLD_AUDIT) == 0
966 && __glibc_unlikely (GLRO(dl_naudit) > 0))
967 {
968 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
969 /* Do not call the functions for any auditing object. */
970 if (head->l_auditing == 0)
971 {
972 struct audit_ifaces *afct = GLRO(dl_audit);
973 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
974 {
975 if (afct->activity != NULL)
976 afct->activity (&link_map_audit_state (head, cnt)->cookie,
977 LA_ACT_ADD);
978
979 afct = afct->next;
980 }
981 }
982 }
983#endif
984
985 /* Notify the debugger we have added some objects. We need to
986 call _dl_debug_initialize in a static program in case dynamic
987 linking has not been used before. */
988 r->r_state = RT_ADD;
989 _dl_debug_state ();
990 LIBC_PROBE (map_start, 2, nsid, r);
991 make_consistent = true;
992 }
993 else
994 assert (r->r_state == RT_ADD);
995
996 /* Enter the new object in the list of loaded objects. */
997 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
998 if (__glibc_unlikely (l == NULL))
999 {
1000#ifdef SHARED
1001 fail_new:
1002#endif
1003 errstring = N_("cannot create shared object descriptor");
1004 goto call_lose_errno;
1005 }
1006
1007 /* Extract the remaining details we need from the ELF header
1008 and then read in the program header table. */
1009 l->l_entry = header->e_entry;
1010 type = header->e_type;
1011 l->l_phnum = header->e_phnum;
1012
1013 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1014 if (header->e_phoff + maplength <= (size_t) fbp->len)
1015 phdr = (void *) (fbp->buf + header->e_phoff);
1016 else
1017 {
1018 phdr = alloca (maplength);
1019 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1020 header->e_phoff) != maplength)
1021 {
1022 errstring = N_("cannot read file data");
1023 goto call_lose_errno;
1024 }
1025 }
1026
1027 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1028 * executable. Other platforms default to a nonexecutable stack and don't
1029 * need PT_GNU_STACK to do so. */
1030 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1031
1032 {
1033 /* Scan the program header table, collecting its load commands. */
1034 struct loadcmd loadcmds[l->l_phnum];
1035 size_t nloadcmds = 0;
1036 bool has_holes = false;
1037
1038 /* The struct is initialized to zero so this is not necessary:
1039 l->l_ld = 0;
1040 l->l_phdr = 0;
1041 l->l_addr = 0; */
1042 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1043 switch (ph->p_type)
1044 {
1045 /* These entries tell us where to find things once the file's
1046 segments are mapped in. We record the addresses it says
1047 verbatim, and later correct for the run-time load address. */
1048 case PT_DYNAMIC:
1049 if (ph->p_filesz)
1050 {
1051 /* Debuginfo only files from "objcopy --only-keep-debug"
1052 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1053 such a segment to avoid a crash later. */
1054 l->l_ld = (void *) ph->p_vaddr;
1055 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1056 }
1057 break;
1058
1059 case PT_PHDR:
1060 l->l_phdr = (void *) ph->p_vaddr;
1061 break;
1062
1063 case PT_LOAD:
1064 /* A load command tells us to map in part of the file.
1065 We record the load commands and process them all later. */
1066 if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0))
1067 {
1068 errstring = N_("ELF load command alignment not page-aligned");
1069 goto call_lose;
1070 }
1071 if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
1072 & (ph->p_align - 1)) != 0))
1073 {
1074 errstring
1075 = N_("ELF load command address/offset not properly aligned");
1076 goto call_lose;
1077 }
1078
1079 struct loadcmd *c = &loadcmds[nloadcmds++];
1080 c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
1081 c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
1082 c->dataend = ph->p_vaddr + ph->p_filesz;
1083 c->allocend = ph->p_vaddr + ph->p_memsz;
1084 c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
1085
1086 /* Determine whether there is a gap between the last segment
1087 and this one. */
1088 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1089 has_holes = true;
1090
1091 /* Optimize a common case. */
1092#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1093 c->prot = (PF_TO_PROT
1094 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1095#else
1096 c->prot = 0;
1097 if (ph->p_flags & PF_R)
1098 c->prot |= PROT_READ;
1099 if (ph->p_flags & PF_W)
1100 c->prot |= PROT_WRITE;
1101 if (ph->p_flags & PF_X)
1102 c->prot |= PROT_EXEC;
1103#endif
1104 break;
1105
1106 case PT_TLS:
1107 if (ph->p_memsz == 0)
1108 /* Nothing to do for an empty segment. */
1109 break;
1110
1111 l->l_tls_blocksize = ph->p_memsz;
1112 l->l_tls_align = ph->p_align;
1113 if (ph->p_align == 0)
1114 l->l_tls_firstbyte_offset = 0;
1115 else
1116 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1117 l->l_tls_initimage_size = ph->p_filesz;
1118 /* Since we don't know the load address yet only store the
1119 offset. We will adjust it later. */
1120 l->l_tls_initimage = (void *) ph->p_vaddr;
1121
1122 /* l->l_tls_modid is assigned below, once there is no
1123 possibility for failure. */
1124
1125 if (l->l_type != lt_library
1126 && GL(dl_tls_dtv_slotinfo_list) == NULL)
1127 {
1128#ifdef SHARED
1129 /* We are loading the executable itself when the dynamic
1130 linker was executed directly. The setup will happen
1131 later. */
1132 assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
1133#else
1134 assert (false && "TLS not initialized in static application");
1135#endif
1136 }
1137 break;
1138
1139 case PT_GNU_STACK:
1140 stack_flags = ph->p_flags;
1141 break;
1142
1143 case PT_GNU_RELRO:
1144 l->l_relro_addr = ph->p_vaddr;
1145 l->l_relro_size = ph->p_memsz;
1146 break;
1147
1148 case PT_NOTE:
1149 if (_dl_process_pt_note (l, ph, fd, fbp))
1150 {
1151 errstring = N_("cannot process note segment");
1152 goto call_lose;
1153 }
1154 break;
1155 }
1156
1157 if (__glibc_unlikely (nloadcmds == 0))
1158 {
1159 /* This only happens for a bogus object that will be caught with
1160 another error below. But we don't want to go through the
1161 calculations below using NLOADCMDS - 1. */
1162 errstring = N_("object file has no loadable segments");
1163 goto call_lose;
1164 }
1165
1166 /* dlopen of an executable is not valid because it is not possible
1167 to perform proper relocations, handle static TLS, or run the
1168 ELF constructors. For PIE, the check needs the dynamic
1169 section, so there is another check below. */
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, or a PIE object. */
1207 if ((__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1208 && (mode & __RTLD_DLOPEN))
1209 || (__glibc_unlikely (l->l_flags_1 & DF_1_PIE)
1210 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0)))
1211 {
1212 /* We are not supposed to load this object. Free all resources. */
1213 _dl_unmap_segments (l);
1214
1215 if (!l->l_libname->dont_free)
1216 free (l->l_libname);
1217
1218 if (l->l_phdr_allocated)
1219 free ((void *) l->l_phdr);
1220
1221 if (l->l_flags_1 & DF_1_PIE)
1222 errstring
1223 = N_("cannot dynamically load position-independent executable");
1224 else
1225 errstring = N_("shared object cannot be dlopen()ed");
1226 goto call_lose;
1227 }
1228
1229 if (l->l_phdr == NULL)
1230 {
1231 /* The program header is not contained in any of the segments.
1232 We have to allocate memory ourself and copy it over from out
1233 temporary place. */
1234 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1235 * sizeof (ElfW(Phdr)));
1236 if (newp == NULL)
1237 {
1238 errstring = N_("cannot allocate memory for program header");
1239 goto call_lose_errno;
1240 }
1241
1242 l->l_phdr = memcpy (newp, phdr,
1243 (header->e_phnum * sizeof (ElfW(Phdr))));
1244 l->l_phdr_allocated = 1;
1245 }
1246 else
1247 /* Adjust the PT_PHDR value by the runtime load address. */
1248 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1249
1250 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
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_("\
1292cannot 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_nocancel (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 /* _dl_close can only eventually undo the module ID assignment (via
1378 remove_slotinfo) if this function returns a pointer to a link
1379 map. Therefore, delay this step until all possibilities for
1380 failure have been excluded. */
1381 if (l->l_tls_blocksize > 0
1382 && (__glibc_likely (l->l_type == lt_library)
1383 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1384 not set up TLS data structures, so don't use them now. */
1385 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL)))
1386 /* Assign the next available module ID. */
1387 l->l_tls_modid = _dl_next_tls_modid ();
1388
1389#ifdef DL_AFTER_LOAD
1390 DL_AFTER_LOAD (l);
1391#endif
1392
1393 /* Now that the object is fully initialized add it to the object list. */
1394 _dl_add_to_namespace_list (l, nsid);
1395
1396#ifdef SHARED
1397 /* Auditing checkpoint: we have a new object. */
1398 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1399 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1400 {
1401 struct audit_ifaces *afct = GLRO(dl_audit);
1402 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1403 {
1404 if (afct->objopen != NULL)
1405 {
1406 struct auditstate *state = link_map_audit_state (l, cnt);
1407 state->bindflags = afct->objopen (l, nsid, &state->cookie);
1408 l->l_audit_any_plt |= state->bindflags != 0;
1409 }
1410
1411 afct = afct->next;
1412 }
1413 }
1414#endif
1415
1416 return l;
1417}
1418
1419/* Print search path. */
1420static void
1421print_search_path (struct r_search_path_elem **list,
1422 const char *what, const char *name)
1423{
1424 char buf[max_dirnamelen + max_capstrlen];
1425 int first = 1;
1426
1427 _dl_debug_printf (" search path=");
1428
1429 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1430 {
1431 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1432 size_t cnt;
1433
1434 for (cnt = 0; cnt < ncapstr; ++cnt)
1435 if ((*list)->status[cnt] != nonexisting)
1436 {
1437 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1438 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1439 cp[0] = '\0';
1440 else
1441 cp[-1] = '\0';
1442
1443 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1444 first = 0;
1445 }
1446
1447 ++list;
1448 }
1449
1450 if (name != NULL)
1451 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1452 DSO_FILENAME (name));
1453 else
1454 _dl_debug_printf_c ("\t\t(%s)\n", what);
1455}
1456
1457/* Open a file and verify it is an ELF file for this architecture. We
1458 ignore only ELF files for other architectures. Non-ELF files and
1459 ELF files with different header information cause fatal errors since
1460 this could mean there is something wrong in the installation and the
1461 user might want to know about this.
1462
1463 If FD is not -1, then the file is already open and FD refers to it.
1464 In that case, FD is consumed for both successful and error returns. */
1465static int
1466open_verify (const char *name, int fd,
1467 struct filebuf *fbp, struct link_map *loader,
1468 int whatcode, int mode, bool *found_other_class, bool free_name)
1469{
1470 /* This is the expected ELF header. */
1471#define ELF32_CLASS ELFCLASS32
1472#define ELF64_CLASS ELFCLASS64
1473#ifndef VALID_ELF_HEADER
1474# define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1475# define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1476# define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1477#elif defined MORE_ELF_HEADER_DATA
1478 MORE_ELF_HEADER_DATA;
1479#endif
1480 static const unsigned char expected[EI_NIDENT] =
1481 {
1482 [EI_MAG0] = ELFMAG0,
1483 [EI_MAG1] = ELFMAG1,
1484 [EI_MAG2] = ELFMAG2,
1485 [EI_MAG3] = ELFMAG3,
1486 [EI_CLASS] = ELFW(CLASS),
1487 [EI_DATA] = byteorder,
1488 [EI_VERSION] = EV_CURRENT,
1489 [EI_OSABI] = ELFOSABI_SYSV,
1490 [EI_ABIVERSION] = 0
1491 };
1492 static const struct
1493 {
1494 ElfW(Word) vendorlen;
1495 ElfW(Word) datalen;
1496 ElfW(Word) type;
1497 char vendor[4];
1498 } expected_note = { 4, 16, 1, "GNU" };
1499 /* Initialize it to make the compiler happy. */
1500 const char *errstring = NULL;
1501 int errval = 0;
1502
1503#ifdef SHARED
1504 /* Give the auditing libraries a chance. */
1505 if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
1506 && loader->l_auditing == 0)
1507 {
1508 const char *original_name = name;
1509 struct audit_ifaces *afct = GLRO(dl_audit);
1510 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1511 {
1512 if (afct->objsearch != NULL)
1513 {
1514 struct auditstate *state = link_map_audit_state (loader, cnt);
1515 name = afct->objsearch (name, &state->cookie, whatcode);
1516 if (name == NULL)
1517 /* Ignore the path. */
1518 return -1;
1519 }
1520
1521 afct = afct->next;
1522 }
1523
1524 if (fd != -1 && name != original_name && strcmp (name, original_name))
1525 {
1526 /* An audit library changed what we're supposed to open,
1527 so FD no longer matches it. */
1528 __close_nocancel (fd);
1529 fd = -1;
1530 }
1531 }
1532#endif
1533
1534 if (fd == -1)
1535 /* Open the file. We always open files read-only. */
1536 fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
1537
1538 if (fd != -1)
1539 {
1540 ElfW(Ehdr) *ehdr;
1541 ElfW(Phdr) *phdr, *ph;
1542 ElfW(Word) *abi_note;
1543 ElfW(Word) *abi_note_malloced = NULL;
1544 unsigned int osversion;
1545 size_t maplength;
1546
1547 /* We successfully opened the file. Now verify it is a file
1548 we can use. */
1549 __set_errno (0);
1550 fbp->len = 0;
1551 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1552 /* Read in the header. */
1553 do
1554 {
1555 ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
1556 sizeof (fbp->buf) - fbp->len);
1557 if (retlen <= 0)
1558 break;
1559 fbp->len += retlen;
1560 }
1561 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1562
1563 /* This is where the ELF header is loaded. */
1564 ehdr = (ElfW(Ehdr) *) fbp->buf;
1565
1566 /* Now run the tests. */
1567 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1568 {
1569 errval = errno;
1570 errstring = (errval == 0
1571 ? N_("file too short") : N_("cannot read file data"));
1572 call_lose:
1573 if (free_name)
1574 {
1575 char *realname = (char *) name;
1576 name = strdupa (realname);
1577 free (realname);
1578 }
1579 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1580 }
1581
1582 /* See whether the ELF header is what we expect. */
1583 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1584 EI_ABIVERSION)
1585 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1586 ehdr->e_ident[EI_ABIVERSION])
1587 || memcmp (&ehdr->e_ident[EI_PAD],
1588 &expected[EI_PAD],
1589 EI_NIDENT - EI_PAD) != 0))
1590 {
1591 /* Something is wrong. */
1592 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1593 if (*magp !=
1594#if BYTE_ORDER == LITTLE_ENDIAN
1595 ((ELFMAG0 << (EI_MAG0 * 8))
1596 | (ELFMAG1 << (EI_MAG1 * 8))
1597 | (ELFMAG2 << (EI_MAG2 * 8))
1598 | (ELFMAG3 << (EI_MAG3 * 8)))
1599#else
1600 ((ELFMAG0 << (EI_MAG3 * 8))
1601 | (ELFMAG1 << (EI_MAG2 * 8))
1602 | (ELFMAG2 << (EI_MAG1 * 8))
1603 | (ELFMAG3 << (EI_MAG0 * 8)))
1604#endif
1605 )
1606 errstring = N_("invalid ELF header");
1607 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1608 {
1609 /* This is not a fatal error. On architectures where
1610 32-bit and 64-bit binaries can be run this might
1611 happen. */
1612 *found_other_class = true;
1613 goto close_and_out;
1614 }
1615 else if (ehdr->e_ident[EI_DATA] != byteorder)
1616 {
1617 if (BYTE_ORDER == BIG_ENDIAN)
1618 errstring = N_("ELF file data encoding not big-endian");
1619 else
1620 errstring = N_("ELF file data encoding not little-endian");
1621 }
1622 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1623 errstring
1624 = N_("ELF file version ident does not match current one");
1625 /* XXX We should be able so set system specific versions which are
1626 allowed here. */
1627 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1628 errstring = N_("ELF file OS ABI invalid");
1629 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1630 ehdr->e_ident[EI_ABIVERSION]))
1631 errstring = N_("ELF file ABI version invalid");
1632 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1633 EI_NIDENT - EI_PAD) != 0)
1634 errstring = N_("nonzero padding in e_ident");
1635 else
1636 /* Otherwise we don't know what went wrong. */
1637 errstring = N_("internal error");
1638
1639 goto call_lose;
1640 }
1641
1642 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1643 {
1644 errstring = N_("ELF file version does not match current one");
1645 goto call_lose;
1646 }
1647 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1648 goto close_and_out;
1649 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1650 && ehdr->e_type != ET_EXEC))
1651 {
1652 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1653 goto call_lose;
1654 }
1655 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1656 {
1657 errstring = N_("ELF file's phentsize not the expected size");
1658 goto call_lose;
1659 }
1660
1661 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1662 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1663 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1664 else
1665 {
1666 phdr = alloca (maplength);
1667 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1668 ehdr->e_phoff) != maplength)
1669 {
1670 read_error:
1671 errval = errno;
1672 errstring = N_("cannot read file data");
1673 goto call_lose;
1674 }
1675 }
1676
1677 if (__glibc_unlikely (elf_machine_reject_phdr_p
1678 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1679 loader, fd)))
1680 goto close_and_out;
1681
1682 /* Check .note.ABI-tag if present. */
1683 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1684 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32
1685 && (ph->p_align == 4 || ph->p_align == 8))
1686 {
1687 ElfW(Addr) size = ph->p_filesz;
1688
1689 if (ph->p_offset + size <= (size_t) fbp->len)
1690 abi_note = (void *) (fbp->buf + ph->p_offset);
1691 else
1692 {
1693 /* Note: __libc_use_alloca is not usable here, because
1694 thread info may not have been set up yet. */
1695 if (size < __MAX_ALLOCA_CUTOFF)
1696 abi_note = alloca (size);
1697 else
1698 {
1699 /* There could be multiple PT_NOTEs. */
1700 abi_note_malloced = realloc (abi_note_malloced, size);
1701 if (abi_note_malloced == NULL)
1702 goto read_error;
1703
1704 abi_note = abi_note_malloced;
1705 }
1706 if (__pread64_nocancel (fd, (void *) abi_note, size,
1707 ph->p_offset) != size)
1708 {
1709 free (abi_note_malloced);
1710 goto read_error;
1711 }
1712 }
1713
1714 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1715 {
1716 ElfW(Addr) note_size
1717 = ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
1718 ph->p_align);
1719
1720 if (size - 32 < note_size)
1721 {
1722 size = 0;
1723 break;
1724 }
1725 size -= note_size;
1726 abi_note = (void *) abi_note + note_size;
1727 }
1728
1729 if (size == 0)
1730 continue;
1731
1732 osversion = (abi_note[5] & 0xff) * 65536
1733 + (abi_note[6] & 0xff) * 256
1734 + (abi_note[7] & 0xff);
1735 if (abi_note[4] != __ABI_TAG_OS
1736 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1737 {
1738 close_and_out:
1739 __close_nocancel (fd);
1740 __set_errno (ENOENT);
1741 fd = -1;
1742 }
1743
1744 break;
1745 }
1746 free (abi_note_malloced);
1747 }
1748
1749 return fd;
1750}
1751
1752/* Try to open NAME in one of the directories in *DIRSP.
1753 Return the fd, or -1. If successful, fill in *REALNAME
1754 with the malloc'd full directory name. If it turns out
1755 that none of the directories in *DIRSP exists, *DIRSP is
1756 replaced with (void *) -1, and the old value is free()d
1757 if MAY_FREE_DIRS is true. */
1758
1759static int
1760open_path (const char *name, size_t namelen, int mode,
1761 struct r_search_path_struct *sps, char **realname,
1762 struct filebuf *fbp, struct link_map *loader, int whatcode,
1763 bool *found_other_class)
1764{
1765 struct r_search_path_elem **dirs = sps->dirs;
1766 char *buf;
1767 int fd = -1;
1768 const char *current_what = NULL;
1769 int any = 0;
1770
1771 if (__glibc_unlikely (dirs == NULL))
1772 /* We're called before _dl_init_paths when loading the main executable
1773 given on the command line when rtld is run directly. */
1774 return -1;
1775
1776 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1777 do
1778 {
1779 struct r_search_path_elem *this_dir = *dirs;
1780 size_t buflen = 0;
1781 size_t cnt;
1782 char *edp;
1783 int here_any = 0;
1784 int err;
1785
1786 /* If we are debugging the search for libraries print the path
1787 now if it hasn't happened now. */
1788 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1789 && current_what != this_dir->what)
1790 {
1791 current_what = this_dir->what;
1792 print_search_path (dirs, current_what, this_dir->where);
1793 }
1794
1795 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1796 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1797 {
1798 /* Skip this directory if we know it does not exist. */
1799 if (this_dir->status[cnt] == nonexisting)
1800 continue;
1801
1802 buflen =
1803 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1804 capstr[cnt].len),
1805 name, namelen)
1806 - buf);
1807
1808 /* Print name we try if this is wanted. */
1809 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1810 _dl_debug_printf (" trying file=%s\n", buf);
1811
1812 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1813 found_other_class, false);
1814 if (this_dir->status[cnt] == unknown)
1815 {
1816 if (fd != -1)
1817 this_dir->status[cnt] = existing;
1818 /* Do not update the directory information when loading
1819 auditing code. We must try to disturb the program as
1820 little as possible. */
1821 else if (loader == NULL
1822 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1823 {
1824 /* We failed to open machine dependent library. Let's
1825 test whether there is any directory at all. */
1826 struct stat64 st;
1827
1828 buf[buflen - namelen - 1] = '\0';
1829
1830 if (__xstat64 (_STAT_VER, buf, &st) != 0
1831 || ! S_ISDIR (st.st_mode))
1832 /* The directory does not exist or it is no directory. */
1833 this_dir->status[cnt] = nonexisting;
1834 else
1835 this_dir->status[cnt] = existing;
1836 }
1837 }
1838
1839 /* Remember whether we found any existing directory. */
1840 here_any |= this_dir->status[cnt] != nonexisting;
1841
1842 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1843 && __libc_enable_secure)
1844 {
1845 /* This is an extra security effort to make sure nobody can
1846 preload broken shared objects which are in the trusted
1847 directories and so exploit the bugs. */
1848 struct stat64 st;
1849
1850 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1851 || (st.st_mode & S_ISUID) == 0)
1852 {
1853 /* The shared object cannot be tested for being SUID
1854 or this bit is not set. In this case we must not
1855 use this object. */
1856 __close_nocancel (fd);
1857 fd = -1;
1858 /* We simply ignore the file, signal this by setting
1859 the error value which would have been set by `open'. */
1860 errno = ENOENT;
1861 }
1862 }
1863 }
1864
1865 if (fd != -1)
1866 {
1867 *realname = (char *) malloc (buflen);
1868 if (*realname != NULL)
1869 {
1870 memcpy (*realname, buf, buflen);
1871 return fd;
1872 }
1873 else
1874 {
1875 /* No memory for the name, we certainly won't be able
1876 to load and link it. */
1877 __close_nocancel (fd);
1878 return -1;
1879 }
1880 }
1881 if (here_any && (err = errno) != ENOENT && err != EACCES)
1882 /* The file exists and is readable, but something went wrong. */
1883 return -1;
1884
1885 /* Remember whether we found anything. */
1886 any |= here_any;
1887 }
1888 while (*++dirs != NULL);
1889
1890 /* Remove the whole path if none of the directories exists. */
1891 if (__glibc_unlikely (! any))
1892 {
1893 /* Paths which were allocated using the minimal malloc() in ld.so
1894 must not be freed using the general free() in libc. */
1895 if (sps->malloced)
1896 free (sps->dirs);
1897
1898 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1899 avoid writing into it. */
1900 if (sps != &rtld_search_dirs && sps != &env_path_list)
1901 sps->dirs = (void *) -1;
1902 }
1903
1904 return -1;
1905}
1906
1907/* Map in the shared object file NAME. */
1908
1909struct link_map *
1910_dl_map_object (struct link_map *loader, const char *name,
1911 int type, int trace_mode, int mode, Lmid_t nsid)
1912{
1913 int fd;
1914 const char *origname = NULL;
1915 char *realname;
1916 char *name_copy;
1917 struct link_map *l;
1918 struct filebuf fb;
1919
1920 assert (nsid >= 0);
1921 assert (nsid < GL(dl_nns));
1922
1923 /* Look for this name among those already loaded. */
1924 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1925 {
1926 /* If the requested name matches the soname of a loaded object,
1927 use that object. Elide this check for names that have not
1928 yet been opened. */
1929 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
1930 continue;
1931 if (!_dl_name_match_p (name, l))
1932 {
1933 const char *soname;
1934
1935 if (__glibc_likely (l->l_soname_added)
1936 || l->l_info[DT_SONAME] == NULL)
1937 continue;
1938
1939 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1940 + l->l_info[DT_SONAME]->d_un.d_val);
1941 if (strcmp (name, soname) != 0)
1942 continue;
1943
1944 /* We have a match on a new name -- cache it. */
1945 add_name_to_object (l, soname);
1946 l->l_soname_added = 1;
1947 }
1948
1949 /* We have a match. */
1950 return l;
1951 }
1952
1953 /* Display information if we are debugging. */
1954 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1955 && loader != NULL)
1956 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
1957 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1958 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1959 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
1960
1961#ifdef SHARED
1962 /* Give the auditing libraries a chance to change the name before we
1963 try anything. */
1964 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1965 && (loader == NULL || loader->l_auditing == 0))
1966 {
1967 struct audit_ifaces *afct = GLRO(dl_audit);
1968 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1969 {
1970 if (afct->objsearch != NULL)
1971 {
1972 const char *before = name;
1973 struct auditstate *state = link_map_audit_state (loader, cnt);
1974 name = afct->objsearch (name, &state->cookie, LA_SER_ORIG);
1975 if (name == NULL)
1976 {
1977 /* Do not try anything further. */
1978 fd = -1;
1979 goto no_file;
1980 }
1981 if (before != name && strcmp (before, name) != 0)
1982 {
1983 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1984 _dl_debug_printf ("audit changed filename %s -> %s\n",
1985 before, name);
1986
1987 if (origname == NULL)
1988 origname = before;
1989 }
1990 }
1991
1992 afct = afct->next;
1993 }
1994 }
1995#endif
1996
1997 /* Will be true if we found a DSO which is of the other ELF class. */
1998 bool found_other_class = false;
1999
2000 if (strchr (name, '/') == NULL)
2001 {
2002 /* Search for NAME in several places. */
2003
2004 size_t namelen = strlen (name) + 1;
2005
2006 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2007 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2008
2009 fd = -1;
2010
2011 /* When the object has the RUNPATH information we don't use any
2012 RPATHs. */
2013 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2014 {
2015 /* This is the executable's map (if there is one). Make sure that
2016 we do not look at it twice. */
2017 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2018 bool did_main_map = false;
2019
2020 /* First try the DT_RPATH of the dependent object that caused NAME
2021 to be loaded. Then that object's dependent, and on up. */
2022 for (l = loader; l; l = l->l_loader)
2023 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2024 {
2025 fd = open_path (name, namelen, mode,
2026 &l->l_rpath_dirs,
2027 &realname, &fb, loader, LA_SER_RUNPATH,
2028 &found_other_class);
2029 if (fd != -1)
2030 break;
2031
2032 did_main_map |= l == main_map;
2033 }
2034
2035 /* If dynamically linked, try the DT_RPATH of the executable
2036 itself. NB: we do this for lookups in any namespace. */
2037 if (fd == -1 && !did_main_map
2038 && main_map != NULL && main_map->l_type != lt_loaded
2039 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2040 "RPATH"))
2041 fd = open_path (name, namelen, mode,
2042 &main_map->l_rpath_dirs,
2043 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2044 &found_other_class);
2045 }
2046
2047 /* Try the LD_LIBRARY_PATH environment variable. */
2048 if (fd == -1 && env_path_list.dirs != (void *) -1)
2049 fd = open_path (name, namelen, mode, &env_path_list,
2050 &realname, &fb,
2051 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2052 LA_SER_LIBPATH, &found_other_class);
2053
2054 /* Look at the RUNPATH information for this binary. */
2055 if (fd == -1 && loader != NULL
2056 && cache_rpath (loader, &loader->l_runpath_dirs,
2057 DT_RUNPATH, "RUNPATH"))
2058 fd = open_path (name, namelen, mode,
2059 &loader->l_runpath_dirs, &realname, &fb, loader,
2060 LA_SER_RUNPATH, &found_other_class);
2061
2062 if (fd == -1)
2063 {
2064 realname = _dl_sysdep_open_object (name, namelen, &fd);
2065 if (realname != NULL)
2066 {
2067 fd = open_verify (realname, fd,
2068 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2069 LA_SER_CONFIG, mode, &found_other_class,
2070 false);
2071 if (fd == -1)
2072 free (realname);
2073 }
2074 }
2075
2076#ifdef USE_LDCONFIG
2077 if (fd == -1
2078 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2079 || ! __libc_enable_secure)
2080 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2081 {
2082 /* Check the list of libraries in the file /etc/ld.so.cache,
2083 for compatibility with Linux's ldconfig program. */
2084 char *cached = _dl_load_cache_lookup (name);
2085
2086 if (cached != NULL)
2087 {
2088 // XXX Correct to unconditionally default to namespace 0?
2089 l = (loader
2090 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2091# ifdef SHARED
2092 ?: &GL(dl_rtld_map)
2093# endif
2094 );
2095
2096 /* If the loader has the DF_1_NODEFLIB flag set we must not
2097 use a cache entry from any of these directories. */
2098 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2099 {
2100 const char *dirp = system_dirs;
2101 unsigned int cnt = 0;
2102
2103 do
2104 {
2105 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2106 {
2107 /* The prefix matches. Don't use the entry. */
2108 free (cached);
2109 cached = NULL;
2110 break;
2111 }
2112
2113 dirp += system_dirs_len[cnt] + 1;
2114 ++cnt;
2115 }
2116 while (cnt < nsystem_dirs_len);
2117 }
2118
2119 if (cached != NULL)
2120 {
2121 fd = open_verify (cached, -1,
2122 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2123 LA_SER_CONFIG, mode, &found_other_class,
2124 false);
2125 if (__glibc_likely (fd != -1))
2126 realname = cached;
2127 else
2128 free (cached);
2129 }
2130 }
2131 }
2132#endif
2133
2134 /* Finally, try the default path. */
2135 if (fd == -1
2136 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2137 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2138 && rtld_search_dirs.dirs != (void *) -1)
2139 fd = open_path (name, namelen, mode, &rtld_search_dirs,
2140 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2141
2142 /* Add another newline when we are tracing the library loading. */
2143 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2144 _dl_debug_printf ("\n");
2145 }
2146 else
2147 {
2148 /* The path may contain dynamic string tokens. */
2149 realname = (loader
2150 ? expand_dynamic_string_token (loader, name)
2151 : __strdup (name));
2152 if (realname == NULL)
2153 fd = -1;
2154 else
2155 {
2156 fd = open_verify (realname, -1, &fb,
2157 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2158 &found_other_class, true);
2159 if (__glibc_unlikely (fd == -1))
2160 free (realname);
2161 }
2162 }
2163
2164#ifdef SHARED
2165 no_file:
2166#endif
2167 /* In case the LOADER information has only been provided to get to
2168 the appropriate RUNPATH/RPATH information we do not need it
2169 anymore. */
2170 if (mode & __RTLD_CALLMAP)
2171 loader = NULL;
2172
2173 if (__glibc_unlikely (fd == -1))
2174 {
2175 if (trace_mode
2176 && __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
2177 {
2178 /* We haven't found an appropriate library. But since we
2179 are only interested in the list of libraries this isn't
2180 so severe. Fake an entry with all the information we
2181 have. */
2182 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2183
2184 /* Allocate a new object map. */
2185 if ((name_copy = __strdup (name)) == NULL
2186 || (l = _dl_new_object (name_copy, name, type, loader,
2187 mode, nsid)) == NULL)
2188 {
2189 free (name_copy);
2190 _dl_signal_error (ENOMEM, name, NULL,
2191 N_("cannot create shared object descriptor"));
2192 }
2193 /* Signal that this is a faked entry. */
2194 l->l_faked = 1;
2195 /* Since the descriptor is initialized with zero we do not
2196 have do this here.
2197 l->l_reserved = 0; */
2198 l->l_buckets = &dummy_bucket;
2199 l->l_nbuckets = 1;
2200 l->l_relocated = 1;
2201
2202 /* Enter the object in the object list. */
2203 _dl_add_to_namespace_list (l, nsid);
2204
2205 return l;
2206 }
2207 else if (found_other_class)
2208 _dl_signal_error (0, name, NULL,
2209 ELFW(CLASS) == ELFCLASS32
2210 ? N_("wrong ELF class: ELFCLASS64")
2211 : N_("wrong ELF class: ELFCLASS32"));
2212 else
2213 _dl_signal_error (errno, name, NULL,
2214 N_("cannot open shared object file"));
2215 }
2216
2217 void *stack_end = __libc_stack_end;
2218 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2219 type, mode, &stack_end, nsid);
2220}
2221
2222struct add_path_state
2223{
2224 bool counting;
2225 unsigned int idx;
2226 Dl_serinfo *si;
2227 char *allocptr;
2228};
2229
2230static void
2231add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2232 unsigned int flags)
2233{
2234 if (sps->dirs != (void *) -1)
2235 {
2236 struct r_search_path_elem **dirs = sps->dirs;
2237 do
2238 {
2239 const struct r_search_path_elem *const r = *dirs++;
2240 if (p->counting)
2241 {
2242 p->si->dls_cnt++;
2243 p->si->dls_size += MAX (2, r->dirnamelen);
2244 }
2245 else
2246 {
2247 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2248 sp->dls_name = p->allocptr;
2249 if (r->dirnamelen < 2)
2250 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2251 else
2252 p->allocptr = __mempcpy (p->allocptr,
2253 r->dirname, r->dirnamelen - 1);
2254 *p->allocptr++ = '\0';
2255 sp->dls_flags = flags;
2256 }
2257 }
2258 while (*dirs != NULL);
2259 }
2260}
2261
2262void
2263_dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2264{
2265 if (counting)
2266 {
2267 si->dls_cnt = 0;
2268 si->dls_size = 0;
2269 }
2270
2271 struct add_path_state p =
2272 {
2273 .counting = counting,
2274 .idx = 0,
2275 .si = si,
2276 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2277 };
2278
2279# define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2280
2281 /* When the object has the RUNPATH information we don't use any RPATHs. */
2282 if (loader->l_info[DT_RUNPATH] == NULL)
2283 {
2284 /* First try the DT_RPATH of the dependent object that caused NAME
2285 to be loaded. Then that object's dependent, and on up. */
2286
2287 struct link_map *l = loader;
2288 do
2289 {
2290 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2291 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2292 l = l->l_loader;
2293 }
2294 while (l != NULL);
2295
2296 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2297 if (loader->l_ns == LM_ID_BASE)
2298 {
2299 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2300 if (l != NULL && l->l_type != lt_loaded && l != loader)
2301 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2302 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2303 }
2304 }
2305
2306 /* Try the LD_LIBRARY_PATH environment variable. */
2307 add_path (&p, &env_path_list, XXX_ENV);
2308
2309 /* Look at the RUNPATH information for this binary. */
2310 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2311 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2312
2313 /* XXX
2314 Here is where ld.so.cache gets checked, but we don't have
2315 a way to indicate that in the results for Dl_serinfo. */
2316
2317 /* Finally, try the default path. */
2318 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2319 add_path (&p, &rtld_search_dirs, XXX_default);
2320
2321 if (counting)
2322 /* Count the struct size before the string area, which we didn't
2323 know before we completed dls_cnt. */
2324 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;
2325}
2326