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 /* dlopen of an executable is not valid because it is not possible
1162 to perform proper relocations, handle static TLS, or run the
1163 ELF constructors. For PIE, the check needs the dynamic
1164 section, so there is another check below. */
1165 if (__glibc_unlikely (type != ET_DYN)
1166 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
1167 {
1168 /* This object is loaded at a fixed address. This must never
1169 happen for objects loaded with dlopen. */
1170 errstring = N_("cannot dynamically load executable");
1171 goto call_lose;
1172 }
1173
1174 /* Length of the sections to be loaded. */
1175 maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
1176
1177 /* Now process the load commands and map segments into memory.
1178 This is responsible for filling in:
1179 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1180 */
1181 errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
1182 maplength, has_holes, loader);
1183 if (__glibc_unlikely (errstring != NULL))
1184 goto call_lose;
1185 }
1186
1187 if (l->l_ld == 0)
1188 {
1189 if (__glibc_unlikely (type == ET_DYN))
1190 {
1191 errstring = N_("object file has no dynamic section");
1192 goto call_lose;
1193 }
1194 }
1195 else
1196 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1197
1198 elf_get_dynamic_info (l, NULL);
1199
1200 /* Make sure we are not dlopen'ing an object that has the
1201 DF_1_NOOPEN flag set, or a PIE object. */
1202 if ((__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1203 && (mode & __RTLD_DLOPEN))
1204 || (__glibc_unlikely (l->l_flags_1 & DF_1_PIE)
1205 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0)))
1206 {
1207 /* We are not supposed to load this object. Free all resources. */
1208 _dl_unmap_segments (l);
1209
1210 if (!l->l_libname->dont_free)
1211 free (l->l_libname);
1212
1213 if (l->l_phdr_allocated)
1214 free ((void *) l->l_phdr);
1215
1216 if (l->l_flags_1 & DF_1_PIE)
1217 errstring
1218 = N_("cannot dynamically load position-independent executable");
1219 else
1220 errstring = N_("shared object cannot be dlopen()ed");
1221 goto call_lose;
1222 }
1223
1224 if (l->l_phdr == NULL)
1225 {
1226 /* The program header is not contained in any of the segments.
1227 We have to allocate memory ourself and copy it over from out
1228 temporary place. */
1229 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1230 * sizeof (ElfW(Phdr)));
1231 if (newp == NULL)
1232 {
1233 errstring = N_("cannot allocate memory for program header");
1234 goto call_lose_errno;
1235 }
1236
1237 l->l_phdr = memcpy (newp, phdr,
1238 (header->e_phnum * sizeof (ElfW(Phdr))));
1239 l->l_phdr_allocated = 1;
1240 }
1241 else
1242 /* Adjust the PT_PHDR value by the runtime load address. */
1243 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1244
1245 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
1246 {
1247 /* The stack is presently not executable, but this module
1248 requires that it be executable. We must change the
1249 protection of the variable which contains the flags used in
1250 the mprotect calls. */
1251#ifdef SHARED
1252 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1253 {
1254 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1255 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1256
1257 struct link_map *const m = &GL(dl_rtld_map);
1258 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1259 + m->l_relro_size)
1260 & -GLRO(dl_pagesize));
1261 if (__glibc_likely (p + s <= relro_end))
1262 {
1263 /* The variable lies in the region protected by RELRO. */
1264 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1265 {
1266 errstring = N_("cannot change memory protections");
1267 goto call_lose_errno;
1268 }
1269 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1270 __mprotect ((void *) p, s, PROT_READ);
1271 }
1272 else
1273 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1274 }
1275 else
1276#endif
1277 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1278
1279#ifdef check_consistency
1280 check_consistency ();
1281#endif
1282
1283 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1284 if (errval)
1285 {
1286 errstring = N_("\
1287cannot enable executable stack as shared object requires");
1288 goto call_lose;
1289 }
1290 }
1291
1292 /* Adjust the address of the TLS initialization image. */
1293 if (l->l_tls_initimage != NULL)
1294 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1295
1296 /* We are done mapping in the file. We no longer need the descriptor. */
1297 if (__glibc_unlikely (__close_nocancel (fd) != 0))
1298 {
1299 errstring = N_("cannot close file descriptor");
1300 goto call_lose_errno;
1301 }
1302 /* Signal that we closed the file. */
1303 fd = -1;
1304
1305 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1306 assert (type != ET_EXEC || l->l_type == lt_executable);
1307
1308 l->l_entry += l->l_addr;
1309
1310 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1311 _dl_debug_printf ("\
1312 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1313 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1314 (int) sizeof (void *) * 2,
1315 (unsigned long int) l->l_ld,
1316 (int) sizeof (void *) * 2,
1317 (unsigned long int) l->l_addr,
1318 (int) sizeof (void *) * 2, maplength,
1319 (int) sizeof (void *) * 2,
1320 (unsigned long int) l->l_entry,
1321 (int) sizeof (void *) * 2,
1322 (unsigned long int) l->l_phdr,
1323 (int) sizeof (void *) * 2, l->l_phnum);
1324
1325 /* Set up the symbol hash table. */
1326 _dl_setup_hash (l);
1327
1328 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1329 have to do this for the main map. */
1330 if ((mode & RTLD_DEEPBIND) == 0
1331 && __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
1332 && &l->l_searchlist != l->l_scope[0])
1333 {
1334 /* Create an appropriate searchlist. It contains only this map.
1335 This is the definition of DT_SYMBOLIC in SysVr4. */
1336 l->l_symbolic_searchlist.r_list[0] = l;
1337 l->l_symbolic_searchlist.r_nlist = 1;
1338
1339 /* Now move the existing entries one back. */
1340 memmove (&l->l_scope[1], &l->l_scope[0],
1341 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1342
1343 /* Now add the new entry. */
1344 l->l_scope[0] = &l->l_symbolic_searchlist;
1345 }
1346
1347 /* Remember whether this object must be initialized first. */
1348 if (l->l_flags_1 & DF_1_INITFIRST)
1349 GL(dl_initfirst) = l;
1350
1351 /* Finally the file information. */
1352 l->l_file_id = id;
1353
1354#ifdef SHARED
1355 /* When auditing is used the recorded names might not include the
1356 name by which the DSO is actually known. Add that as well. */
1357 if (__glibc_unlikely (origname != NULL))
1358 add_name_to_object (l, origname);
1359#else
1360 /* Audit modules only exist when linking is dynamic so ORIGNAME
1361 cannot be non-NULL. */
1362 assert (origname == NULL);
1363#endif
1364
1365 /* When we profile the SONAME might be needed for something else but
1366 loading. Add it right away. */
1367 if (__glibc_unlikely (GLRO(dl_profile) != NULL)
1368 && l->l_info[DT_SONAME] != NULL)
1369 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1370 + l->l_info[DT_SONAME]->d_un.d_val));
1371
1372#ifdef DL_AFTER_LOAD
1373 DL_AFTER_LOAD (l);
1374#endif
1375
1376 /* Now that the object is fully initialized add it to the object list. */
1377 _dl_add_to_namespace_list (l, nsid);
1378
1379#ifdef SHARED
1380 /* Auditing checkpoint: we have a new object. */
1381 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1382 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1383 {
1384 struct audit_ifaces *afct = GLRO(dl_audit);
1385 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1386 {
1387 if (afct->objopen != NULL)
1388 {
1389 l->l_audit[cnt].bindflags
1390 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1391
1392 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1393 }
1394
1395 afct = afct->next;
1396 }
1397 }
1398#endif
1399
1400 return l;
1401}
1402
1403/* Print search path. */
1404static void
1405print_search_path (struct r_search_path_elem **list,
1406 const char *what, const char *name)
1407{
1408 char buf[max_dirnamelen + max_capstrlen];
1409 int first = 1;
1410
1411 _dl_debug_printf (" search path=");
1412
1413 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1414 {
1415 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1416 size_t cnt;
1417
1418 for (cnt = 0; cnt < ncapstr; ++cnt)
1419 if ((*list)->status[cnt] != nonexisting)
1420 {
1421 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1422 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1423 cp[0] = '\0';
1424 else
1425 cp[-1] = '\0';
1426
1427 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1428 first = 0;
1429 }
1430
1431 ++list;
1432 }
1433
1434 if (name != NULL)
1435 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1436 DSO_FILENAME (name));
1437 else
1438 _dl_debug_printf_c ("\t\t(%s)\n", what);
1439}
1440
1441/* Open a file and verify it is an ELF file for this architecture. We
1442 ignore only ELF files for other architectures. Non-ELF files and
1443 ELF files with different header information cause fatal errors since
1444 this could mean there is something wrong in the installation and the
1445 user might want to know about this.
1446
1447 If FD is not -1, then the file is already open and FD refers to it.
1448 In that case, FD is consumed for both successful and error returns. */
1449static int
1450open_verify (const char *name, int fd,
1451 struct filebuf *fbp, struct link_map *loader,
1452 int whatcode, int mode, bool *found_other_class, bool free_name)
1453{
1454 /* This is the expected ELF header. */
1455#define ELF32_CLASS ELFCLASS32
1456#define ELF64_CLASS ELFCLASS64
1457#ifndef VALID_ELF_HEADER
1458# define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1459# define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1460# define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1461#elif defined MORE_ELF_HEADER_DATA
1462 MORE_ELF_HEADER_DATA;
1463#endif
1464 static const unsigned char expected[EI_NIDENT] =
1465 {
1466 [EI_MAG0] = ELFMAG0,
1467 [EI_MAG1] = ELFMAG1,
1468 [EI_MAG2] = ELFMAG2,
1469 [EI_MAG3] = ELFMAG3,
1470 [EI_CLASS] = ELFW(CLASS),
1471 [EI_DATA] = byteorder,
1472 [EI_VERSION] = EV_CURRENT,
1473 [EI_OSABI] = ELFOSABI_SYSV,
1474 [EI_ABIVERSION] = 0
1475 };
1476 static const struct
1477 {
1478 ElfW(Word) vendorlen;
1479 ElfW(Word) datalen;
1480 ElfW(Word) type;
1481 char vendor[4];
1482 } expected_note = { 4, 16, 1, "GNU" };
1483 /* Initialize it to make the compiler happy. */
1484 const char *errstring = NULL;
1485 int errval = 0;
1486
1487#ifdef SHARED
1488 /* Give the auditing libraries a chance. */
1489 if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
1490 && loader->l_auditing == 0)
1491 {
1492 const char *original_name = name;
1493 struct audit_ifaces *afct = GLRO(dl_audit);
1494 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1495 {
1496 if (afct->objsearch != NULL)
1497 {
1498 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1499 whatcode);
1500 if (name == NULL)
1501 /* Ignore the path. */
1502 return -1;
1503 }
1504
1505 afct = afct->next;
1506 }
1507
1508 if (fd != -1 && name != original_name && strcmp (name, original_name))
1509 {
1510 /* An audit library changed what we're supposed to open,
1511 so FD no longer matches it. */
1512 __close_nocancel (fd);
1513 fd = -1;
1514 }
1515 }
1516#endif
1517
1518 if (fd == -1)
1519 /* Open the file. We always open files read-only. */
1520 fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
1521
1522 if (fd != -1)
1523 {
1524 ElfW(Ehdr) *ehdr;
1525 ElfW(Phdr) *phdr, *ph;
1526 ElfW(Word) *abi_note;
1527 ElfW(Word) *abi_note_malloced = NULL;
1528 unsigned int osversion;
1529 size_t maplength;
1530
1531 /* We successfully opened the file. Now verify it is a file
1532 we can use. */
1533 __set_errno (0);
1534 fbp->len = 0;
1535 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1536 /* Read in the header. */
1537 do
1538 {
1539 ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
1540 sizeof (fbp->buf) - fbp->len);
1541 if (retlen <= 0)
1542 break;
1543 fbp->len += retlen;
1544 }
1545 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1546
1547 /* This is where the ELF header is loaded. */
1548 ehdr = (ElfW(Ehdr) *) fbp->buf;
1549
1550 /* Now run the tests. */
1551 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1552 {
1553 errval = errno;
1554 errstring = (errval == 0
1555 ? N_("file too short") : N_("cannot read file data"));
1556 call_lose:
1557 if (free_name)
1558 {
1559 char *realname = (char *) name;
1560 name = strdupa (realname);
1561 free (realname);
1562 }
1563 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1564 }
1565
1566 /* See whether the ELF header is what we expect. */
1567 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1568 EI_ABIVERSION)
1569 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1570 ehdr->e_ident[EI_ABIVERSION])
1571 || memcmp (&ehdr->e_ident[EI_PAD],
1572 &expected[EI_PAD],
1573 EI_NIDENT - EI_PAD) != 0))
1574 {
1575 /* Something is wrong. */
1576 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1577 if (*magp !=
1578#if BYTE_ORDER == LITTLE_ENDIAN
1579 ((ELFMAG0 << (EI_MAG0 * 8))
1580 | (ELFMAG1 << (EI_MAG1 * 8))
1581 | (ELFMAG2 << (EI_MAG2 * 8))
1582 | (ELFMAG3 << (EI_MAG3 * 8)))
1583#else
1584 ((ELFMAG0 << (EI_MAG3 * 8))
1585 | (ELFMAG1 << (EI_MAG2 * 8))
1586 | (ELFMAG2 << (EI_MAG1 * 8))
1587 | (ELFMAG3 << (EI_MAG0 * 8)))
1588#endif
1589 )
1590 errstring = N_("invalid ELF header");
1591 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1592 {
1593 /* This is not a fatal error. On architectures where
1594 32-bit and 64-bit binaries can be run this might
1595 happen. */
1596 *found_other_class = true;
1597 goto close_and_out;
1598 }
1599 else if (ehdr->e_ident[EI_DATA] != byteorder)
1600 {
1601 if (BYTE_ORDER == BIG_ENDIAN)
1602 errstring = N_("ELF file data encoding not big-endian");
1603 else
1604 errstring = N_("ELF file data encoding not little-endian");
1605 }
1606 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1607 errstring
1608 = N_("ELF file version ident does not match current one");
1609 /* XXX We should be able so set system specific versions which are
1610 allowed here. */
1611 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1612 errstring = N_("ELF file OS ABI invalid");
1613 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1614 ehdr->e_ident[EI_ABIVERSION]))
1615 errstring = N_("ELF file ABI version invalid");
1616 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1617 EI_NIDENT - EI_PAD) != 0)
1618 errstring = N_("nonzero padding in e_ident");
1619 else
1620 /* Otherwise we don't know what went wrong. */
1621 errstring = N_("internal error");
1622
1623 goto call_lose;
1624 }
1625
1626 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1627 {
1628 errstring = N_("ELF file version does not match current one");
1629 goto call_lose;
1630 }
1631 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1632 goto close_and_out;
1633 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1634 && ehdr->e_type != ET_EXEC))
1635 {
1636 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1637 goto call_lose;
1638 }
1639 else if (__glibc_unlikely (ehdr->e_type == ET_EXEC
1640 && (mode & __RTLD_OPENEXEC) == 0))
1641 {
1642 /* BZ #16634. It is an error to dlopen ET_EXEC (unless
1643 __RTLD_OPENEXEC is explicitly set). We return error here
1644 so that code in _dl_map_object_from_fd does not try to set
1645 l_tls_modid for this module. */
1646
1647 errstring = N_("cannot dynamically load executable");
1648 goto call_lose;
1649 }
1650 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1651 {
1652 errstring = N_("ELF file's phentsize not the expected size");
1653 goto call_lose;
1654 }
1655
1656 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1657 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1658 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1659 else
1660 {
1661 phdr = alloca (maplength);
1662 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1663 if ((size_t) __read_nocancel (fd, (void *) phdr, maplength)
1664 != maplength)
1665 {
1666 read_error:
1667 errval = errno;
1668 errstring = N_("cannot read file data");
1669 goto call_lose;
1670 }
1671 }
1672
1673 if (__glibc_unlikely (elf_machine_reject_phdr_p
1674 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1675 loader, fd)))
1676 goto close_and_out;
1677
1678 /* Check .note.ABI-tag if present. */
1679 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1680 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1681 {
1682 ElfW(Addr) size = ph->p_filesz;
1683 /* NB: Some PT_NOTE segment may have alignment value of 0
1684 or 1. gABI specifies that PT_NOTE segments should be
1685 aligned to 4 bytes in 32-bit objects and to 8 bytes in
1686 64-bit objects. As a Linux extension, we also support
1687 4 byte alignment in 64-bit objects. If p_align is less
1688 than 4, we treate alignment as 4 bytes since some note
1689 segments have 0 or 1 byte alignment. */
1690 ElfW(Addr) align = ph->p_align;
1691 if (align < 4)
1692 align = 4;
1693 else if (align != 4 && align != 8)
1694 continue;
1695
1696 if (ph->p_offset + size <= (size_t) fbp->len)
1697 abi_note = (void *) (fbp->buf + ph->p_offset);
1698 else
1699 {
1700 /* Note: __libc_use_alloca is not usable here, because
1701 thread info may not have been set up yet. */
1702 if (size < __MAX_ALLOCA_CUTOFF)
1703 abi_note = alloca (size);
1704 else
1705 {
1706 /* There could be multiple PT_NOTEs. */
1707 abi_note_malloced = realloc (abi_note_malloced, size);
1708 if (abi_note_malloced == NULL)
1709 goto read_error;
1710
1711 abi_note = abi_note_malloced;
1712 }
1713 __lseek (fd, ph->p_offset, SEEK_SET);
1714 if (__read_nocancel (fd, (void *) abi_note, size) != size)
1715 {
1716 free (abi_note_malloced);
1717 goto read_error;
1718 }
1719 }
1720
1721 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1722 {
1723 ElfW(Addr) note_size
1724 = ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
1725 align);
1726
1727 if (size - 32 < note_size)
1728 {
1729 size = 0;
1730 break;
1731 }
1732 size -= note_size;
1733 abi_note = (void *) abi_note + note_size;
1734 }
1735
1736 if (size == 0)
1737 continue;
1738
1739 osversion = (abi_note[5] & 0xff) * 65536
1740 + (abi_note[6] & 0xff) * 256
1741 + (abi_note[7] & 0xff);
1742 if (abi_note[4] != __ABI_TAG_OS
1743 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1744 {
1745 close_and_out:
1746 __close_nocancel (fd);
1747 __set_errno (ENOENT);
1748 fd = -1;
1749 }
1750
1751 break;
1752 }
1753 free (abi_note_malloced);
1754 }
1755
1756 return fd;
1757}
1758
1759/* Try to open NAME in one of the directories in *DIRSP.
1760 Return the fd, or -1. If successful, fill in *REALNAME
1761 with the malloc'd full directory name. If it turns out
1762 that none of the directories in *DIRSP exists, *DIRSP is
1763 replaced with (void *) -1, and the old value is free()d
1764 if MAY_FREE_DIRS is true. */
1765
1766static int
1767open_path (const char *name, size_t namelen, int mode,
1768 struct r_search_path_struct *sps, char **realname,
1769 struct filebuf *fbp, struct link_map *loader, int whatcode,
1770 bool *found_other_class)
1771{
1772 struct r_search_path_elem **dirs = sps->dirs;
1773 char *buf;
1774 int fd = -1;
1775 const char *current_what = NULL;
1776 int any = 0;
1777
1778 if (__glibc_unlikely (dirs == NULL))
1779 /* We're called before _dl_init_paths when loading the main executable
1780 given on the command line when rtld is run directly. */
1781 return -1;
1782
1783 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1784 do
1785 {
1786 struct r_search_path_elem *this_dir = *dirs;
1787 size_t buflen = 0;
1788 size_t cnt;
1789 char *edp;
1790 int here_any = 0;
1791 int err;
1792
1793 /* If we are debugging the search for libraries print the path
1794 now if it hasn't happened now. */
1795 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1796 && current_what != this_dir->what)
1797 {
1798 current_what = this_dir->what;
1799 print_search_path (dirs, current_what, this_dir->where);
1800 }
1801
1802 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1803 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1804 {
1805 /* Skip this directory if we know it does not exist. */
1806 if (this_dir->status[cnt] == nonexisting)
1807 continue;
1808
1809 buflen =
1810 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1811 capstr[cnt].len),
1812 name, namelen)
1813 - buf);
1814
1815 /* Print name we try if this is wanted. */
1816 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1817 _dl_debug_printf (" trying file=%s\n", buf);
1818
1819 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1820 found_other_class, false);
1821 if (this_dir->status[cnt] == unknown)
1822 {
1823 if (fd != -1)
1824 this_dir->status[cnt] = existing;
1825 /* Do not update the directory information when loading
1826 auditing code. We must try to disturb the program as
1827 little as possible. */
1828 else if (loader == NULL
1829 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1830 {
1831 /* We failed to open machine dependent library. Let's
1832 test whether there is any directory at all. */
1833 struct stat64 st;
1834
1835 buf[buflen - namelen - 1] = '\0';
1836
1837 if (__xstat64 (_STAT_VER, buf, &st) != 0
1838 || ! S_ISDIR (st.st_mode))
1839 /* The directory does not exist or it is no directory. */
1840 this_dir->status[cnt] = nonexisting;
1841 else
1842 this_dir->status[cnt] = existing;
1843 }
1844 }
1845
1846 /* Remember whether we found any existing directory. */
1847 here_any |= this_dir->status[cnt] != nonexisting;
1848
1849 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1850 && __libc_enable_secure)
1851 {
1852 /* This is an extra security effort to make sure nobody can
1853 preload broken shared objects which are in the trusted
1854 directories and so exploit the bugs. */
1855 struct stat64 st;
1856
1857 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1858 || (st.st_mode & S_ISUID) == 0)
1859 {
1860 /* The shared object cannot be tested for being SUID
1861 or this bit is not set. In this case we must not
1862 use this object. */
1863 __close_nocancel (fd);
1864 fd = -1;
1865 /* We simply ignore the file, signal this by setting
1866 the error value which would have been set by `open'. */
1867 errno = ENOENT;
1868 }
1869 }
1870 }
1871
1872 if (fd != -1)
1873 {
1874 *realname = (char *) malloc (buflen);
1875 if (*realname != NULL)
1876 {
1877 memcpy (*realname, buf, buflen);
1878 return fd;
1879 }
1880 else
1881 {
1882 /* No memory for the name, we certainly won't be able
1883 to load and link it. */
1884 __close_nocancel (fd);
1885 return -1;
1886 }
1887 }
1888 if (here_any && (err = errno) != ENOENT && err != EACCES)
1889 /* The file exists and is readable, but something went wrong. */
1890 return -1;
1891
1892 /* Remember whether we found anything. */
1893 any |= here_any;
1894 }
1895 while (*++dirs != NULL);
1896
1897 /* Remove the whole path if none of the directories exists. */
1898 if (__glibc_unlikely (! any))
1899 {
1900 /* Paths which were allocated using the minimal malloc() in ld.so
1901 must not be freed using the general free() in libc. */
1902 if (sps->malloced)
1903 free (sps->dirs);
1904
1905 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1906 avoid writing into it. */
1907 if (sps != &rtld_search_dirs && sps != &env_path_list)
1908 sps->dirs = (void *) -1;
1909 }
1910
1911 return -1;
1912}
1913
1914/* Map in the shared object file NAME. */
1915
1916struct link_map *
1917_dl_map_object (struct link_map *loader, const char *name,
1918 int type, int trace_mode, int mode, Lmid_t nsid)
1919{
1920 int fd;
1921 const char *origname = NULL;
1922 char *realname;
1923 char *name_copy;
1924 struct link_map *l;
1925 struct filebuf fb;
1926
1927 assert (nsid >= 0);
1928 assert (nsid < GL(dl_nns));
1929
1930 /* Look for this name among those already loaded. */
1931 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1932 {
1933 /* If the requested name matches the soname of a loaded object,
1934 use that object. Elide this check for names that have not
1935 yet been opened. */
1936 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
1937 continue;
1938 if (!_dl_name_match_p (name, l))
1939 {
1940 const char *soname;
1941
1942 if (__glibc_likely (l->l_soname_added)
1943 || l->l_info[DT_SONAME] == NULL)
1944 continue;
1945
1946 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1947 + l->l_info[DT_SONAME]->d_un.d_val);
1948 if (strcmp (name, soname) != 0)
1949 continue;
1950
1951 /* We have a match on a new name -- cache it. */
1952 add_name_to_object (l, soname);
1953 l->l_soname_added = 1;
1954 }
1955
1956 /* We have a match. */
1957 return l;
1958 }
1959
1960 /* Display information if we are debugging. */
1961 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1962 && loader != NULL)
1963 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
1964 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1965 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1966 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
1967
1968#ifdef SHARED
1969 /* Give the auditing libraries a chance to change the name before we
1970 try anything. */
1971 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1972 && (loader == NULL || loader->l_auditing == 0))
1973 {
1974 struct audit_ifaces *afct = GLRO(dl_audit);
1975 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1976 {
1977 if (afct->objsearch != NULL)
1978 {
1979 const char *before = name;
1980 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1981 LA_SER_ORIG);
1982 if (name == NULL)
1983 {
1984 /* Do not try anything further. */
1985 fd = -1;
1986 goto no_file;
1987 }
1988 if (before != name && strcmp (before, name) != 0)
1989 {
1990 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1991 _dl_debug_printf ("audit changed filename %s -> %s\n",
1992 before, name);
1993
1994 if (origname == NULL)
1995 origname = before;
1996 }
1997 }
1998
1999 afct = afct->next;
2000 }
2001 }
2002#endif
2003
2004 /* Will be true if we found a DSO which is of the other ELF class. */
2005 bool found_other_class = false;
2006
2007 if (strchr (name, '/') == NULL)
2008 {
2009 /* Search for NAME in several places. */
2010
2011 size_t namelen = strlen (name) + 1;
2012
2013 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2014 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2015
2016 fd = -1;
2017
2018 /* When the object has the RUNPATH information we don't use any
2019 RPATHs. */
2020 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2021 {
2022 /* This is the executable's map (if there is one). Make sure that
2023 we do not look at it twice. */
2024 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2025 bool did_main_map = false;
2026
2027 /* First try the DT_RPATH of the dependent object that caused NAME
2028 to be loaded. Then that object's dependent, and on up. */
2029 for (l = loader; l; l = l->l_loader)
2030 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2031 {
2032 fd = open_path (name, namelen, mode,
2033 &l->l_rpath_dirs,
2034 &realname, &fb, loader, LA_SER_RUNPATH,
2035 &found_other_class);
2036 if (fd != -1)
2037 break;
2038
2039 did_main_map |= l == main_map;
2040 }
2041
2042 /* If dynamically linked, try the DT_RPATH of the executable
2043 itself. NB: we do this for lookups in any namespace. */
2044 if (fd == -1 && !did_main_map
2045 && main_map != NULL && main_map->l_type != lt_loaded
2046 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2047 "RPATH"))
2048 fd = open_path (name, namelen, mode,
2049 &main_map->l_rpath_dirs,
2050 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2051 &found_other_class);
2052 }
2053
2054 /* Try the LD_LIBRARY_PATH environment variable. */
2055 if (fd == -1 && env_path_list.dirs != (void *) -1)
2056 fd = open_path (name, namelen, mode, &env_path_list,
2057 &realname, &fb,
2058 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2059 LA_SER_LIBPATH, &found_other_class);
2060
2061 /* Look at the RUNPATH information for this binary. */
2062 if (fd == -1 && loader != NULL
2063 && cache_rpath (loader, &loader->l_runpath_dirs,
2064 DT_RUNPATH, "RUNPATH"))
2065 fd = open_path (name, namelen, mode,
2066 &loader->l_runpath_dirs, &realname, &fb, loader,
2067 LA_SER_RUNPATH, &found_other_class);
2068
2069 if (fd == -1)
2070 {
2071 realname = _dl_sysdep_open_object (name, namelen, &fd);
2072 if (realname != NULL)
2073 {
2074 fd = open_verify (realname, fd,
2075 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2076 LA_SER_CONFIG, mode, &found_other_class,
2077 false);
2078 if (fd == -1)
2079 free (realname);
2080 }
2081 }
2082
2083#ifdef USE_LDCONFIG
2084 if (fd == -1
2085 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2086 || ! __libc_enable_secure)
2087 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2088 {
2089 /* Check the list of libraries in the file /etc/ld.so.cache,
2090 for compatibility with Linux's ldconfig program. */
2091 char *cached = _dl_load_cache_lookup (name);
2092
2093 if (cached != NULL)
2094 {
2095 // XXX Correct to unconditionally default to namespace 0?
2096 l = (loader
2097 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2098# ifdef SHARED
2099 ?: &GL(dl_rtld_map)
2100# endif
2101 );
2102
2103 /* If the loader has the DF_1_NODEFLIB flag set we must not
2104 use a cache entry from any of these directories. */
2105 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2106 {
2107 const char *dirp = system_dirs;
2108 unsigned int cnt = 0;
2109
2110 do
2111 {
2112 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2113 {
2114 /* The prefix matches. Don't use the entry. */
2115 free (cached);
2116 cached = NULL;
2117 break;
2118 }
2119
2120 dirp += system_dirs_len[cnt] + 1;
2121 ++cnt;
2122 }
2123 while (cnt < nsystem_dirs_len);
2124 }
2125
2126 if (cached != NULL)
2127 {
2128 fd = open_verify (cached, -1,
2129 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2130 LA_SER_CONFIG, mode, &found_other_class,
2131 false);
2132 if (__glibc_likely (fd != -1))
2133 realname = cached;
2134 else
2135 free (cached);
2136 }
2137 }
2138 }
2139#endif
2140
2141 /* Finally, try the default path. */
2142 if (fd == -1
2143 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2144 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2145 && rtld_search_dirs.dirs != (void *) -1)
2146 fd = open_path (name, namelen, mode, &rtld_search_dirs,
2147 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2148
2149 /* Add another newline when we are tracing the library loading. */
2150 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2151 _dl_debug_printf ("\n");
2152 }
2153 else
2154 {
2155 /* The path may contain dynamic string tokens. */
2156 realname = (loader
2157 ? expand_dynamic_string_token (loader, name)
2158 : __strdup (name));
2159 if (realname == NULL)
2160 fd = -1;
2161 else
2162 {
2163 fd = open_verify (realname, -1, &fb,
2164 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2165 &found_other_class, true);
2166 if (__glibc_unlikely (fd == -1))
2167 free (realname);
2168 }
2169 }
2170
2171#ifdef SHARED
2172 no_file:
2173#endif
2174 /* In case the LOADER information has only been provided to get to
2175 the appropriate RUNPATH/RPATH information we do not need it
2176 anymore. */
2177 if (mode & __RTLD_CALLMAP)
2178 loader = NULL;
2179
2180 if (__glibc_unlikely (fd == -1))
2181 {
2182 if (trace_mode
2183 && __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
2184 {
2185 /* We haven't found an appropriate library. But since we
2186 are only interested in the list of libraries this isn't
2187 so severe. Fake an entry with all the information we
2188 have. */
2189 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2190
2191 /* Allocate a new object map. */
2192 if ((name_copy = __strdup (name)) == NULL
2193 || (l = _dl_new_object (name_copy, name, type, loader,
2194 mode, nsid)) == NULL)
2195 {
2196 free (name_copy);
2197 _dl_signal_error (ENOMEM, name, NULL,
2198 N_("cannot create shared object descriptor"));
2199 }
2200 /* Signal that this is a faked entry. */
2201 l->l_faked = 1;
2202 /* Since the descriptor is initialized with zero we do not
2203 have do this here.
2204 l->l_reserved = 0; */
2205 l->l_buckets = &dummy_bucket;
2206 l->l_nbuckets = 1;
2207 l->l_relocated = 1;
2208
2209 /* Enter the object in the object list. */
2210 _dl_add_to_namespace_list (l, nsid);
2211
2212 return l;
2213 }
2214 else if (found_other_class)
2215 _dl_signal_error (0, name, NULL,
2216 ELFW(CLASS) == ELFCLASS32
2217 ? N_("wrong ELF class: ELFCLASS64")
2218 : N_("wrong ELF class: ELFCLASS32"));
2219 else
2220 _dl_signal_error (errno, name, NULL,
2221 N_("cannot open shared object file"));
2222 }
2223
2224 void *stack_end = __libc_stack_end;
2225 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2226 type, mode, &stack_end, nsid);
2227}
2228
2229struct add_path_state
2230{
2231 bool counting;
2232 unsigned int idx;
2233 Dl_serinfo *si;
2234 char *allocptr;
2235};
2236
2237static void
2238add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2239 unsigned int flags)
2240{
2241 if (sps->dirs != (void *) -1)
2242 {
2243 struct r_search_path_elem **dirs = sps->dirs;
2244 do
2245 {
2246 const struct r_search_path_elem *const r = *dirs++;
2247 if (p->counting)
2248 {
2249 p->si->dls_cnt++;
2250 p->si->dls_size += MAX (2, r->dirnamelen);
2251 }
2252 else
2253 {
2254 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2255 sp->dls_name = p->allocptr;
2256 if (r->dirnamelen < 2)
2257 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2258 else
2259 p->allocptr = __mempcpy (p->allocptr,
2260 r->dirname, r->dirnamelen - 1);
2261 *p->allocptr++ = '\0';
2262 sp->dls_flags = flags;
2263 }
2264 }
2265 while (*dirs != NULL);
2266 }
2267}
2268
2269void
2270_dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2271{
2272 if (counting)
2273 {
2274 si->dls_cnt = 0;
2275 si->dls_size = 0;
2276 }
2277
2278 struct add_path_state p =
2279 {
2280 .counting = counting,
2281 .idx = 0,
2282 .si = si,
2283 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2284 };
2285
2286# define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2287
2288 /* When the object has the RUNPATH information we don't use any RPATHs. */
2289 if (loader->l_info[DT_RUNPATH] == NULL)
2290 {
2291 /* First try the DT_RPATH of the dependent object that caused NAME
2292 to be loaded. Then that object's dependent, and on up. */
2293
2294 struct link_map *l = loader;
2295 do
2296 {
2297 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2298 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2299 l = l->l_loader;
2300 }
2301 while (l != NULL);
2302
2303 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2304 if (loader->l_ns == LM_ID_BASE)
2305 {
2306 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2307 if (l != NULL && l->l_type != lt_loaded && l != loader)
2308 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2309 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2310 }
2311 }
2312
2313 /* Try the LD_LIBRARY_PATH environment variable. */
2314 add_path (&p, &env_path_list, XXX_ENV);
2315
2316 /* Look at the RUNPATH information for this binary. */
2317 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2318 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2319
2320 /* XXX
2321 Here is where ld.so.cache gets checked, but we don't have
2322 a way to indicate that in the results for Dl_serinfo. */
2323
2324 /* Finally, try the default path. */
2325 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2326 add_path (&p, &rtld_search_dirs, XXX_default);
2327
2328 if (counting)
2329 /* Count the struct size before the string area, which we didn't
2330 know before we completed dls_cnt. */
2331 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;
2332}
2333