Make __mach_msg_destroy portable for x86_64
[glibc.git] / elf / dl-load.c
blob9a0e40c0e99b7427264864d487df2069fd34d3b8
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2023 Free Software Foundation, Inc.
3 Copyright The GNU Toolchain Authors.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
20 #include <elf.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <libintl.h>
24 #include <stdbool.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 #include <ldsodefs.h>
29 #include <bits/wordsize.h>
30 #include <sys/mman.h>
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <gnu/lib-names.h>
36 /* Type for the buffer we put the ELF header and hopefully the program
37 header. This buffer does not really have to be too large. In most
38 cases the program header follows the ELF header directly. If this
39 is not the case all bets are off and we can make the header
40 arbitrarily large and still won't get it read. This means the only
41 question is how large are the ELF and program header combined. The
42 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
43 bytes long. Each program header entry is again 32 and 56 bytes
44 long respectively. I.e., even with a file which has 10 program
45 header entries we only have to read 372B/624B respectively. Add to
46 this a bit of margin for program notes and reading 512B and 832B
47 for 32-bit and 64-bit files respecitvely is enough. If this
48 heuristic should really fail for some file the code in
49 `_dl_map_object_from_fd' knows how to recover. */
50 struct filebuf
52 ssize_t len;
53 #if __WORDSIZE == 32
54 # define FILEBUF_SIZE 512
55 #else
56 # define FILEBUF_SIZE 832
57 #endif
58 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
61 #include "dynamic-link.h"
62 #include "get-dynamic-info.h"
63 #include <abi-tag.h>
64 #include <stackinfo.h>
65 #include <sysdep.h>
66 #include <stap-probe.h>
67 #include <libc-pointer-arith.h>
68 #include <array_length.h>
70 #include <dl-dst.h>
71 #include <dl-load.h>
72 #include <dl-map-segments.h>
73 #include <dl-unmap-segments.h>
74 #include <dl-machine-reject-phdr.h>
75 #include <dl-sysdep-open.h>
76 #include <dl-prop.h>
77 #include <not-cancel.h>
79 #include <endian.h>
80 #if BYTE_ORDER == BIG_ENDIAN
81 # define byteorder ELFDATA2MSB
82 #elif BYTE_ORDER == LITTLE_ENDIAN
83 # define byteorder ELFDATA2LSB
84 #else
85 # error "Unknown BYTE_ORDER " BYTE_ORDER
86 # define byteorder ELFDATANONE
87 #endif
89 #define STRING(x) __STRING (x)
92 int __stack_prot attribute_hidden attribute_relro
93 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
94 = PROT_GROWSDOWN;
95 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
96 = PROT_GROWSUP;
97 #else
98 = 0;
99 #endif
102 /* This is the decomposed LD_LIBRARY_PATH search path. */
103 struct r_search_path_struct __rtld_env_path_list attribute_relro;
105 /* List of the hardware capabilities we might end up using. */
106 #ifdef SHARED
107 static const struct r_strlenpair *capstr attribute_relro;
108 static size_t ncapstr attribute_relro;
109 static size_t max_capstrlen attribute_relro;
110 #else
111 enum { ncapstr = 1, max_capstrlen = 0 };
112 #endif
115 /* Get the generated information about the trusted directories. Use
116 an array of concatenated strings to avoid relocations. See
117 gen-trusted-dirs.awk. */
118 #include "trusted-dirs.h"
120 static const char system_dirs[] = SYSTEM_DIRS;
121 static const size_t system_dirs_len[] =
123 SYSTEM_DIRS_LEN
125 #define nsystem_dirs_len array_length (system_dirs_len)
127 static bool
128 is_trusted_path_normalize (const char *path, size_t len)
130 if (len == 0)
131 return false;
133 char *npath = (char *) alloca (len + 2);
134 char *wnp = npath;
135 while (*path != '\0')
137 if (path[0] == '/')
139 if (path[1] == '.')
141 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
143 while (wnp > npath && *--wnp != '/')
145 path += 3;
146 continue;
148 else if (path[2] == '/' || path[2] == '\0')
150 path += 2;
151 continue;
155 if (wnp > npath && wnp[-1] == '/')
157 ++path;
158 continue;
162 *wnp++ = *path++;
165 if (wnp == npath || wnp[-1] != '/')
166 *wnp++ = '/';
168 const char *trun = system_dirs;
170 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
172 if (wnp - npath >= system_dirs_len[idx]
173 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
174 /* Found it. */
175 return true;
177 trun += system_dirs_len[idx] + 1;
180 return false;
183 /* Given a substring starting at INPUT, just after the DST '$' start
184 token, determine if INPUT contains DST token REF, following the
185 ELF gABI rules for DSTs:
187 * Longest possible sequence using the rules (greedy).
189 * Must start with a $ (enforced by caller).
191 * Must follow $ with one underscore or ASCII [A-Za-z] (caller
192 follows these rules for REF) or '{' (start curly quoted name).
194 * Must follow first two characters with zero or more [A-Za-z0-9_]
195 (enforced by caller) or '}' (end curly quoted name).
197 If the sequence is a DST matching REF then the length of the DST
198 (excluding the $ sign but including curly braces, if any) is
199 returned, otherwise 0. */
200 static size_t
201 is_dst (const char *input, const char *ref)
203 bool is_curly = false;
205 /* Is a ${...} input sequence? */
206 if (input[0] == '{')
208 is_curly = true;
209 ++input;
212 /* Check for matching name, following closing curly brace (if
213 required), or trailing characters which are part of an
214 identifier. */
215 size_t rlen = strlen (ref);
216 if (strncmp (input, ref, rlen) != 0
217 || (is_curly && input[rlen] != '}')
218 || ((input[rlen] >= 'A' && input[rlen] <= 'Z')
219 || (input[rlen] >= 'a' && input[rlen] <= 'z')
220 || (input[rlen] >= '0' && input[rlen] <= '9')
221 || (input[rlen] == '_')))
222 return 0;
224 if (is_curly)
225 /* Count the two curly braces. */
226 return rlen + 2;
227 else
228 return rlen;
231 /* INPUT should be the start of a path e.g DT_RPATH or name e.g.
232 DT_NEEDED. The return value is the number of known DSTs found. We
233 count all known DSTs regardless of __libc_enable_secure; the caller
234 is responsible for enforcing the security of the substitution rules
235 (usually _dl_dst_substitute). */
236 size_t
237 _dl_dst_count (const char *input)
239 size_t cnt = 0;
241 input = strchr (input, '$');
243 /* Most likely there is no DST. */
244 if (__glibc_likely (input == NULL))
245 return 0;
249 size_t len;
251 ++input;
252 /* All DSTs must follow ELF gABI rules, see is_dst (). */
253 if ((len = is_dst (input, "ORIGIN")) != 0
254 || (len = is_dst (input, "PLATFORM")) != 0
255 || (len = is_dst (input, "LIB")) != 0)
256 ++cnt;
258 /* There may be more than one DST in the input. */
259 input = strchr (input + len, '$');
261 while (input != NULL);
263 return cnt;
266 /* Process INPUT for DSTs and store in RESULT using the information
267 from link map L to resolve the DSTs. This function only handles one
268 path at a time and does not handle colon-separated path lists (see
269 fillin_rpath ()). Lastly the size of result in bytes should be at
270 least equal to the value returned by DL_DST_REQUIRED. Note that it
271 is possible for a DT_NEEDED, DT_AUXILIARY, and DT_FILTER entries to
272 have colons, but we treat those as literal colons here, not as path
273 list delimeters. */
274 char *
275 _dl_dst_substitute (struct link_map *l, const char *input, char *result)
277 /* Copy character-by-character from input into the working pointer
278 looking for any DSTs. We track the start of input and if we are
279 going to check for trusted paths, all of which are part of $ORIGIN
280 handling in SUID/SGID cases (see below). In some cases, like when
281 a DST cannot be replaced, we may set result to an empty string and
282 return. */
283 char *wp = result;
284 const char *start = input;
285 bool check_for_trusted = false;
289 if (__glibc_unlikely (*input == '$'))
291 const char *repl = NULL;
292 size_t len;
294 ++input;
295 if ((len = is_dst (input, "ORIGIN")) != 0)
297 /* For SUID/GUID programs we normally ignore the path with
298 $ORIGIN in DT_RUNPATH, or DT_RPATH. However, there is
299 one exception to this rule, and it is:
301 * $ORIGIN appears as the first path element, and is
302 the only string in the path or is immediately
303 followed by a path separator and the rest of the
304 path,
306 and ...
308 * The path is rooted in a trusted directory.
310 This exception allows such programs to reference
311 shared libraries in subdirectories of trusted
312 directories. The use case is one of general
313 organization and deployment flexibility.
314 Trusted directories are usually such paths as "/lib64"
315 or "/usr/lib64", and the usual RPATHs take the form of
316 [$ORIGIN/../$LIB/somedir]. */
317 if (__glibc_unlikely (__libc_enable_secure)
318 && !(input == start + 1
319 && (input[len] == '\0' || input[len] == '/')))
320 repl = (const char *) -1;
321 else
322 repl = l->l_origin;
324 check_for_trusted = (__libc_enable_secure
325 && l->l_type == lt_executable);
327 else if ((len = is_dst (input, "PLATFORM")) != 0)
328 repl = GLRO(dl_platform);
329 else if ((len = is_dst (input, "LIB")) != 0)
330 repl = DL_DST_LIB;
332 if (repl != NULL && repl != (const char *) -1)
334 wp = __stpcpy (wp, repl);
335 input += len;
337 else if (len != 0)
339 /* We found a valid DST that we know about, but we could
340 not find a replacement value for it, therefore we
341 cannot use this path and discard it. */
342 *result = '\0';
343 return result;
345 else
346 /* No DST we recognize. */
347 *wp++ = '$';
349 else
351 *wp++ = *input++;
354 while (*input != '\0');
356 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
357 path must be rooted in one of the trusted directories. The $LIB
358 and $PLATFORM DST cannot in any way be manipulated by the caller
359 because they are fixed values that are set by the dynamic loader
360 and therefore any paths using just $LIB or $PLATFORM need not be
361 checked for trust, the authors of the binaries themselves are
362 trusted to have designed this correctly. Only $ORIGIN is tested in
363 this way because it may be manipulated in some ways with hard
364 links. */
365 if (__glibc_unlikely (check_for_trusted)
366 && !is_trusted_path_normalize (result, wp - result))
368 *result = '\0';
369 return result;
372 *wp = '\0';
374 return result;
378 /* Return a malloc allocated copy of INPUT with all recognized DSTs
379 replaced. On some platforms it might not be possible to determine the
380 path from which the object belonging to the map is loaded. In this
381 case the path containing the DST is left out. On error NULL
382 is returned. */
383 static char *
384 expand_dynamic_string_token (struct link_map *l, const char *input)
386 /* We make two runs over the string. First we determine how large the
387 resulting string is and then we copy it over. Since this is no
388 frequently executed operation we are looking here not for performance
389 but rather for code size. */
390 size_t cnt;
391 size_t total;
392 char *result;
394 /* Determine the number of DSTs. */
395 cnt = _dl_dst_count (input);
397 /* If we do not have to replace anything simply copy the string. */
398 if (__glibc_likely (cnt == 0))
399 return __strdup (input);
401 /* Determine the length of the substituted string. */
402 total = DL_DST_REQUIRED (l, input, strlen (input), cnt);
404 /* Allocate the necessary memory. */
405 result = (char *) malloc (total + 1);
406 if (result == NULL)
407 return NULL;
409 return _dl_dst_substitute (l, input, result);
413 /* Add `name' to the list of names for a particular shared object.
414 `name' is expected to have been allocated with malloc and will
415 be freed if the shared object already has this name.
416 Returns false if the object already had this name. */
417 static void
418 add_name_to_object (struct link_map *l, const char *name)
420 struct libname_list *lnp, *lastp;
421 struct libname_list *newname;
422 size_t name_len;
424 lastp = NULL;
425 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
426 if (strcmp (name, lnp->name) == 0)
427 return;
429 name_len = strlen (name) + 1;
430 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
431 if (newname == NULL)
433 /* No more memory. */
434 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
435 return;
437 /* The object should have a libname set from _dl_new_object. */
438 assert (lastp != NULL);
440 newname->name = memcpy (newname + 1, name, name_len);
441 newname->next = NULL;
442 newname->dont_free = 0;
443 /* CONCURRENCY NOTES:
445 Make sure the initialization of newname happens before its address is
446 read from the lastp->next store below.
448 GL(dl_load_lock) is held here (and by other writers, e.g. dlclose), so
449 readers of libname_list->next (e.g. _dl_check_caller or the reads above)
450 can use that for synchronization, however the read in _dl_name_match_p
451 may be executed without holding the lock during _dl_runtime_resolve
452 (i.e. lazy symbol resolution when a function of library l is called).
454 The release MO store below synchronizes with the acquire MO load in
455 _dl_name_match_p. Other writes need to synchronize with that load too,
456 however those happen either early when the process is single threaded
457 (dl_main) or when the library is unloaded (dlclose) and the user has to
458 synchronize library calls with unloading. */
459 atomic_store_release (&lastp->next, newname);
462 /* Standard search directories. */
463 struct r_search_path_struct __rtld_search_dirs attribute_relro;
465 static size_t max_dirnamelen;
467 static struct r_search_path_elem **
468 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
469 const char *what, const char *where, struct link_map *l)
471 char *cp;
472 size_t nelems = 0;
474 while ((cp = __strsep (&rpath, sep)) != NULL)
476 struct r_search_path_elem *dirp;
477 char *to_free = NULL;
478 size_t len = 0;
480 /* `strsep' can pass an empty string. */
481 if (*cp != '\0')
483 to_free = cp = expand_dynamic_string_token (l, cp);
485 /* expand_dynamic_string_token can return NULL in case of empty
486 path or memory allocation failure. */
487 if (cp == NULL)
488 continue;
490 /* Compute the length after dynamic string token expansion and
491 ignore empty paths. */
492 len = strlen (cp);
493 if (len == 0)
495 free (to_free);
496 continue;
499 /* Remove trailing slashes (except for "/"). */
500 while (len > 1 && cp[len - 1] == '/')
501 --len;
503 /* Now add one if there is none so far. */
504 if (len > 0 && cp[len - 1] != '/')
505 cp[len++] = '/';
508 /* See if this directory is already known. */
509 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
510 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
511 break;
513 if (dirp != NULL)
515 /* It is available, see whether it's on our own list. */
516 size_t cnt;
517 for (cnt = 0; cnt < nelems; ++cnt)
518 if (result[cnt] == dirp)
519 break;
521 if (cnt == nelems)
522 result[nelems++] = dirp;
524 else
526 size_t cnt;
527 enum r_dir_status init_val;
528 size_t where_len = where ? strlen (where) + 1 : 0;
530 /* It's a new directory. Create an entry and add it. */
531 dirp = (struct r_search_path_elem *)
532 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
533 + where_len + len + 1);
534 if (dirp == NULL)
535 _dl_signal_error (ENOMEM, NULL, NULL,
536 N_("cannot create cache for search path"));
538 dirp->dirname = ((char *) dirp + sizeof (*dirp)
539 + ncapstr * sizeof (enum r_dir_status));
540 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
541 dirp->dirnamelen = len;
543 if (len > max_dirnamelen)
544 max_dirnamelen = len;
546 /* We have to make sure all the relative directories are
547 never ignored. The current directory might change and
548 all our saved information would be void. */
549 init_val = cp[0] != '/' ? existing : unknown;
550 for (cnt = 0; cnt < ncapstr; ++cnt)
551 dirp->status[cnt] = init_val;
553 dirp->what = what;
554 if (__glibc_likely (where != NULL))
555 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
556 + (ncapstr * sizeof (enum r_dir_status)),
557 where, where_len);
558 else
559 dirp->where = NULL;
561 dirp->next = GL(dl_all_dirs);
562 GL(dl_all_dirs) = dirp;
564 /* Put it in the result array. */
565 result[nelems++] = dirp;
567 free (to_free);
570 /* Terminate the array. */
571 result[nelems] = NULL;
573 return result;
577 static bool
578 decompose_rpath (struct r_search_path_struct *sps,
579 const char *rpath, struct link_map *l, const char *what)
581 /* Make a copy we can work with. */
582 const char *where = l->l_name;
583 char *cp;
584 struct r_search_path_elem **result;
585 size_t nelems;
586 /* Initialize to please the compiler. */
587 const char *errstring = NULL;
589 /* First see whether we must forget the RUNPATH and RPATH from this
590 object. */
591 if (__glibc_unlikely (GLRO(dl_inhibit_rpath) != NULL)
592 && !__libc_enable_secure)
594 const char *inhp = GLRO(dl_inhibit_rpath);
598 const char *wp = where;
600 while (*inhp == *wp && *wp != '\0')
602 ++inhp;
603 ++wp;
606 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
608 /* This object is on the list of objects for which the
609 RUNPATH and RPATH must not be used. */
610 sps->dirs = (void *) -1;
611 return false;
614 while (*inhp != '\0')
615 if (*inhp++ == ':')
616 break;
618 while (*inhp != '\0');
621 /* Ignore empty rpaths. */
622 if (*rpath == '\0')
624 sps->dirs = (struct r_search_path_elem **) -1;
625 return false;
628 /* Make a writable copy. */
629 char *copy = __strdup (rpath);
630 if (copy == NULL)
632 errstring = N_("cannot create RUNPATH/RPATH copy");
633 goto signal_error;
636 /* Count the number of necessary elements in the result array. */
637 nelems = 0;
638 for (cp = copy; *cp != '\0'; ++cp)
639 if (*cp == ':')
640 ++nelems;
642 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
643 number of necessary entries. */
644 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
645 * sizeof (*result));
646 if (result == NULL)
648 free (copy);
649 errstring = N_("cannot create cache for search path");
650 signal_error:
651 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
654 fillin_rpath (copy, result, ":", what, where, l);
656 /* Free the copied RPATH string. `fillin_rpath' make own copies if
657 necessary. */
658 free (copy);
660 /* There is no path after expansion. */
661 if (result[0] == NULL)
663 free (result);
664 sps->dirs = (struct r_search_path_elem **) -1;
665 return false;
668 sps->dirs = result;
669 /* The caller will change this value if we haven't used a real malloc. */
670 sps->malloced = 1;
671 return true;
674 /* Make sure cached path information is stored in *SP
675 and return true if there are any paths to search there. */
676 static bool
677 cache_rpath (struct link_map *l,
678 struct r_search_path_struct *sp,
679 int tag,
680 const char *what)
682 if (sp->dirs == (void *) -1)
683 return false;
685 if (sp->dirs != NULL)
686 return true;
688 if (l->l_info[tag] == NULL)
690 /* There is no path. */
691 sp->dirs = (void *) -1;
692 return false;
695 /* Make sure the cache information is available. */
696 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
697 + l->l_info[tag]->d_un.d_val),
698 l, what);
702 void
703 _dl_init_paths (const char *llp, const char *source,
704 const char *glibc_hwcaps_prepend,
705 const char *glibc_hwcaps_mask)
707 size_t idx;
708 const char *strp;
709 struct r_search_path_elem *pelem, **aelem;
710 size_t round_size;
711 struct link_map __attribute__ ((unused)) *l = NULL;
712 /* Initialize to please the compiler. */
713 const char *errstring = NULL;
715 /* Fill in the information about the application's RPATH and the
716 directories addressed by the LD_LIBRARY_PATH environment variable. */
718 #ifdef SHARED
719 /* Get the capabilities. */
720 capstr = _dl_important_hwcaps (glibc_hwcaps_prepend, glibc_hwcaps_mask,
721 &ncapstr, &max_capstrlen);
722 #endif
724 /* First set up the rest of the default search directory entries. */
725 aelem = __rtld_search_dirs.dirs = (struct r_search_path_elem **)
726 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
727 if (__rtld_search_dirs.dirs == NULL)
729 errstring = N_("cannot create search path array");
730 signal_error:
731 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
734 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
735 + ncapstr * sizeof (enum r_dir_status))
736 / sizeof (struct r_search_path_elem));
738 __rtld_search_dirs.dirs[0]
739 = malloc (nsystem_dirs_len * round_size
740 * sizeof (*__rtld_search_dirs.dirs[0]));
741 if (__rtld_search_dirs.dirs[0] == NULL)
743 errstring = N_("cannot create cache for search path");
744 goto signal_error;
747 __rtld_search_dirs.malloced = 0;
748 pelem = GL(dl_all_dirs) = __rtld_search_dirs.dirs[0];
749 strp = system_dirs;
750 idx = 0;
754 size_t cnt;
756 *aelem++ = pelem;
758 pelem->what = "system search path";
759 pelem->where = NULL;
761 pelem->dirname = strp;
762 pelem->dirnamelen = system_dirs_len[idx];
763 strp += system_dirs_len[idx] + 1;
765 /* System paths must be absolute. */
766 assert (pelem->dirname[0] == '/');
767 for (cnt = 0; cnt < ncapstr; ++cnt)
768 pelem->status[cnt] = unknown;
770 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
772 pelem += round_size;
774 while (idx < nsystem_dirs_len);
776 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
777 *aelem = NULL;
779 /* This points to the map of the main object. If there is no main
780 object (e.g., under --help, use the dynamic loader itself as a
781 stand-in. */
782 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
783 #ifdef SHARED
784 if (l == NULL)
785 l = &GL (dl_rtld_map);
786 #endif
787 assert (l->l_type != lt_loaded);
789 if (l->l_info[DT_RUNPATH])
791 /* Allocate room for the search path and fill in information
792 from RUNPATH. */
793 decompose_rpath (&l->l_runpath_dirs,
794 (const void *) (D_PTR (l, l_info[DT_STRTAB])
795 + l->l_info[DT_RUNPATH]->d_un.d_val),
796 l, "RUNPATH");
797 /* During rtld init the memory is allocated by the stub malloc,
798 prevent any attempt to free it by the normal malloc. */
799 l->l_runpath_dirs.malloced = 0;
801 /* The RPATH is ignored. */
802 l->l_rpath_dirs.dirs = (void *) -1;
804 else
806 l->l_runpath_dirs.dirs = (void *) -1;
808 if (l->l_info[DT_RPATH])
810 /* Allocate room for the search path and fill in information
811 from RPATH. */
812 decompose_rpath (&l->l_rpath_dirs,
813 (const void *) (D_PTR (l, l_info[DT_STRTAB])
814 + l->l_info[DT_RPATH]->d_un.d_val),
815 l, "RPATH");
816 /* During rtld init the memory is allocated by the stub
817 malloc, prevent any attempt to free it by the normal
818 malloc. */
819 l->l_rpath_dirs.malloced = 0;
821 else
822 l->l_rpath_dirs.dirs = (void *) -1;
825 if (llp != NULL && *llp != '\0')
827 char *llp_tmp = strdupa (llp);
829 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
830 elements it has. */
831 size_t nllp = 1;
832 for (const char *cp = llp_tmp; *cp != '\0'; ++cp)
833 if (*cp == ':' || *cp == ';')
834 ++nllp;
836 __rtld_env_path_list.dirs = (struct r_search_path_elem **)
837 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
838 if (__rtld_env_path_list.dirs == NULL)
840 errstring = N_("cannot create cache for search path");
841 goto signal_error;
844 (void) fillin_rpath (llp_tmp, __rtld_env_path_list.dirs, ":;",
845 source, NULL, l);
847 if (__rtld_env_path_list.dirs[0] == NULL)
849 free (__rtld_env_path_list.dirs);
850 __rtld_env_path_list.dirs = (void *) -1;
853 __rtld_env_path_list.malloced = 0;
855 else
856 __rtld_env_path_list.dirs = (void *) -1;
860 /* Process PT_GNU_PROPERTY program header PH in module L after
861 PT_LOAD segments are mapped. Only one NT_GNU_PROPERTY_TYPE_0
862 note is handled which contains processor specific properties.
863 FD is -1 for the kernel mapped main executable otherwise it is
864 the fd used for loading module L. */
866 void
867 _dl_process_pt_gnu_property (struct link_map *l, int fd, const ElfW(Phdr) *ph)
869 const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
870 const ElfW(Addr) size = ph->p_memsz;
871 const ElfW(Addr) align = ph->p_align;
873 /* The NT_GNU_PROPERTY_TYPE_0 note must be aligned to 4 bytes in
874 32-bit objects and to 8 bytes in 64-bit objects. Skip notes
875 with incorrect alignment. */
876 if (align != (__ELF_NATIVE_CLASS / 8))
877 return;
879 const ElfW(Addr) start = (ElfW(Addr)) note;
880 unsigned int last_type = 0;
882 while ((ElfW(Addr)) (note + 1) - start < size)
884 /* Find the NT_GNU_PROPERTY_TYPE_0 note. */
885 if (note->n_namesz == 4
886 && note->n_type == NT_GNU_PROPERTY_TYPE_0
887 && memcmp (note + 1, "GNU", 4) == 0)
889 /* Check for invalid property. */
890 if (note->n_descsz < 8
891 || (note->n_descsz % sizeof (ElfW(Addr))) != 0)
892 return;
894 /* Start and end of property array. */
895 unsigned char *ptr = (unsigned char *) (note + 1) + 4;
896 unsigned char *ptr_end = ptr + note->n_descsz;
900 unsigned int type = *(unsigned int *) ptr;
901 unsigned int datasz = *(unsigned int *) (ptr + 4);
903 /* Property type must be in ascending order. */
904 if (type < last_type)
905 return;
907 ptr += 8;
908 if ((ptr + datasz) > ptr_end)
909 return;
911 last_type = type;
913 /* Target specific property processing. */
914 if (_dl_process_gnu_property (l, fd, type, datasz, ptr) == 0)
915 return;
917 /* Check the next property item. */
918 ptr += ALIGN_UP (datasz, sizeof (ElfW(Addr)));
920 while ((ptr_end - ptr) >= 8);
922 /* Only handle one NT_GNU_PROPERTY_TYPE_0. */
923 return;
926 note = ((const void *) note
927 + ELF_NOTE_NEXT_OFFSET (note->n_namesz, note->n_descsz,
928 align));
933 /* Map in the shared object NAME, actually located in REALNAME, and already
934 opened on FD. */
936 #ifndef EXTERNAL_MAP_FROM_FD
937 static
938 #endif
939 struct link_map *
940 _dl_map_object_from_fd (const char *name, const char *origname, int fd,
941 struct filebuf *fbp, char *realname,
942 struct link_map *loader, int l_type, int mode,
943 void **stack_endp, Lmid_t nsid)
945 struct link_map *l = NULL;
946 const ElfW(Ehdr) *header;
947 const ElfW(Phdr) *phdr;
948 const ElfW(Phdr) *ph;
949 size_t maplength;
950 int type;
951 /* Initialize to keep the compiler happy. */
952 const char *errstring = NULL;
953 int errval = 0;
955 /* Get file information. To match the kernel behavior, do not fill
956 in this information for the executable in case of an explicit
957 loader invocation. */
958 struct r_file_id id;
959 if (mode & __RTLD_OPENEXEC)
961 assert (nsid == LM_ID_BASE);
962 memset (&id, 0, sizeof (id));
964 else
966 if (__glibc_unlikely (!_dl_get_file_id (fd, &id)))
968 errstring = N_("cannot stat shared object");
969 lose_errno:
970 errval = errno;
971 lose:
972 /* The file might already be closed. */
973 if (fd != -1)
974 __close_nocancel (fd);
975 if (l != NULL && l->l_map_start != 0)
976 _dl_unmap_segments (l);
977 if (l != NULL && l->l_origin != (char *) -1l)
978 free ((char *) l->l_origin);
979 if (l != NULL && !l->l_libname->dont_free)
980 free (l->l_libname);
981 if (l != NULL && l->l_phdr_allocated)
982 free ((void *) l->l_phdr);
983 free (l);
984 free (realname);
985 _dl_signal_error (errval, name, NULL, errstring);
988 /* Look again to see if the real name matched another already loaded. */
989 for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
990 if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
992 /* The object is already loaded.
993 Just bump its reference count and return it. */
994 __close_nocancel (fd);
996 /* If the name is not in the list of names for this object add
997 it. */
998 free (realname);
999 add_name_to_object (l, name);
1001 return l;
1005 #ifdef SHARED
1006 /* When loading into a namespace other than the base one we must
1007 avoid loading ld.so since there can only be one copy. Ever. */
1008 if (__glibc_unlikely (nsid != LM_ID_BASE)
1009 && (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
1010 || _dl_name_match_p (name, &GL(dl_rtld_map))))
1012 /* This is indeed ld.so. Create a new link_map which refers to
1013 the real one for almost everything. */
1014 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1015 if (l == NULL)
1016 goto fail_new;
1018 /* Refer to the real descriptor. */
1019 l->l_real = &GL(dl_rtld_map);
1021 /* Copy l_addr and l_ld to avoid a GDB warning with dlmopen(). */
1022 l->l_addr = l->l_real->l_addr;
1023 l->l_ld = l->l_real->l_ld;
1025 /* No need to bump the refcount of the real object, ld.so will
1026 never be unloaded. */
1027 __close_nocancel (fd);
1029 /* Add the map for the mirrored object to the object list. */
1030 _dl_add_to_namespace_list (l, nsid);
1032 return l;
1034 #endif
1036 if (mode & RTLD_NOLOAD)
1038 /* We are not supposed to load the object unless it is already
1039 loaded. So return now. */
1040 free (realname);
1041 __close_nocancel (fd);
1042 return NULL;
1045 /* Print debugging message. */
1046 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1047 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
1049 /* This is the ELF header. We read it in `open_verify'. */
1050 header = (void *) fbp->buf;
1052 /* Enter the new object in the list of loaded objects. */
1053 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1054 if (__glibc_unlikely (l == NULL))
1056 #ifdef SHARED
1057 fail_new:
1058 #endif
1059 errstring = N_("cannot create shared object descriptor");
1060 goto lose_errno;
1063 /* Extract the remaining details we need from the ELF header
1064 and then read in the program header table. */
1065 l->l_entry = header->e_entry;
1066 type = header->e_type;
1067 l->l_phnum = header->e_phnum;
1069 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1070 if (header->e_phoff + maplength <= (size_t) fbp->len)
1071 phdr = (void *) (fbp->buf + header->e_phoff);
1072 else
1074 phdr = alloca (maplength);
1075 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1076 header->e_phoff) != maplength)
1078 errstring = N_("cannot read file data");
1079 goto lose_errno;
1083 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1084 * executable. Other platforms default to a nonexecutable stack and don't
1085 * need PT_GNU_STACK to do so. */
1086 unsigned int stack_flags = DEFAULT_STACK_PERMS;
1089 /* Scan the program header table, collecting its load commands. */
1090 struct loadcmd loadcmds[l->l_phnum];
1091 size_t nloadcmds = 0;
1092 bool has_holes = false;
1093 bool empty_dynamic = false;
1094 ElfW(Addr) p_align_max = 0;
1096 /* The struct is initialized to zero so this is not necessary:
1097 l->l_ld = 0;
1098 l->l_phdr = 0;
1099 l->l_addr = 0; */
1100 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1101 switch (ph->p_type)
1103 /* These entries tell us where to find things once the file's
1104 segments are mapped in. We record the addresses it says
1105 verbatim, and later correct for the run-time load address. */
1106 case PT_DYNAMIC:
1107 if (ph->p_filesz == 0)
1108 empty_dynamic = true; /* Usually separate debuginfo. */
1109 else
1111 /* Debuginfo only files from "objcopy --only-keep-debug"
1112 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1113 such a segment to avoid a crash later. */
1114 l->l_ld = (void *) ph->p_vaddr;
1115 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1116 l->l_ld_readonly = (ph->p_flags & PF_W) == 0;
1118 break;
1120 case PT_PHDR:
1121 l->l_phdr = (void *) ph->p_vaddr;
1122 break;
1124 case PT_LOAD:
1125 /* A load command tells us to map in part of the file.
1126 We record the load commands and process them all later. */
1127 if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
1128 & (GLRO(dl_pagesize) - 1)) != 0))
1130 errstring
1131 = N_("ELF load command address/offset not page-aligned");
1132 goto lose;
1135 struct loadcmd *c = &loadcmds[nloadcmds++];
1136 c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
1137 c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
1138 c->dataend = ph->p_vaddr + ph->p_filesz;
1139 c->allocend = ph->p_vaddr + ph->p_memsz;
1140 /* Remember the maximum p_align. */
1141 if (powerof2 (ph->p_align) && ph->p_align > p_align_max)
1142 p_align_max = ph->p_align;
1143 c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
1145 DIAG_PUSH_NEEDS_COMMENT;
1147 #if __GNUC_PREREQ (11, 0)
1148 /* Suppress invalid GCC warning:
1149 ‘(((char *)loadcmds.113_68 + _933 + 16))[329406144173384849].mapend’ may be used uninitialized [-Wmaybe-uninitialized]
1150 See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106008
1152 DIAG_IGNORE_NEEDS_COMMENT (11, "-Wmaybe-uninitialized");
1153 #endif
1154 /* Determine whether there is a gap between the last segment
1155 and this one. */
1156 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1157 has_holes = true;
1158 DIAG_POP_NEEDS_COMMENT;
1160 /* Optimize a common case. */
1161 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1162 c->prot = (PF_TO_PROT
1163 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1164 #else
1165 c->prot = 0;
1166 if (ph->p_flags & PF_R)
1167 c->prot |= PROT_READ;
1168 if (ph->p_flags & PF_W)
1169 c->prot |= PROT_WRITE;
1170 if (ph->p_flags & PF_X)
1171 c->prot |= PROT_EXEC;
1172 #endif
1173 break;
1175 case PT_TLS:
1176 if (ph->p_memsz == 0)
1177 /* Nothing to do for an empty segment. */
1178 break;
1180 l->l_tls_blocksize = ph->p_memsz;
1181 l->l_tls_align = ph->p_align;
1182 if (ph->p_align == 0)
1183 l->l_tls_firstbyte_offset = 0;
1184 else
1185 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1186 l->l_tls_initimage_size = ph->p_filesz;
1187 /* Since we don't know the load address yet only store the
1188 offset. We will adjust it later. */
1189 l->l_tls_initimage = (void *) ph->p_vaddr;
1191 /* l->l_tls_modid is assigned below, once there is no
1192 possibility for failure. */
1194 if (l->l_type != lt_library
1195 && GL(dl_tls_dtv_slotinfo_list) == NULL)
1197 #ifdef SHARED
1198 /* We are loading the executable itself when the dynamic
1199 linker was executed directly. The setup will happen
1200 later. */
1201 assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
1202 #else
1203 assert (false && "TLS not initialized in static application");
1204 #endif
1206 break;
1208 case PT_GNU_STACK:
1209 stack_flags = ph->p_flags;
1210 break;
1212 case PT_GNU_RELRO:
1213 l->l_relro_addr = ph->p_vaddr;
1214 l->l_relro_size = ph->p_memsz;
1215 break;
1218 if (__glibc_unlikely (nloadcmds == 0))
1220 /* This only happens for a bogus object that will be caught with
1221 another error below. But we don't want to go through the
1222 calculations below using NLOADCMDS - 1. */
1223 errstring = N_("object file has no loadable segments");
1224 goto lose;
1227 /* Align all PT_LOAD segments to the maximum p_align. */
1228 for (size_t i = 0; i < nloadcmds; i++)
1229 loadcmds[i].mapalign = p_align_max;
1231 /* dlopen of an executable is not valid because it is not possible
1232 to perform proper relocations, handle static TLS, or run the
1233 ELF constructors. For PIE, the check needs the dynamic
1234 section, so there is another check below. */
1235 if (__glibc_unlikely (type != ET_DYN)
1236 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
1238 /* This object is loaded at a fixed address. This must never
1239 happen for objects loaded with dlopen. */
1240 errstring = N_("cannot dynamically load executable");
1241 goto lose;
1244 /* This check recognizes most separate debuginfo files. */
1245 if (__glibc_unlikely ((l->l_ld == 0 && type == ET_DYN) || empty_dynamic))
1247 errstring = N_("object file has no dynamic section");
1248 goto lose;
1251 /* Length of the sections to be loaded. */
1252 maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
1254 /* Now process the load commands and map segments into memory.
1255 This is responsible for filling in:
1256 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1258 errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
1259 maplength, has_holes, loader);
1260 if (__glibc_unlikely (errstring != NULL))
1262 /* Mappings can be in an inconsistent state: avoid unmap. */
1263 l->l_map_start = l->l_map_end = 0;
1264 goto lose;
1268 if (l->l_ld != 0)
1269 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1271 elf_get_dynamic_info (l, false, false);
1273 /* Make sure we are not dlopen'ing an object that has the
1274 DF_1_NOOPEN flag set, or a PIE object. */
1275 if ((__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1276 && (mode & __RTLD_DLOPEN))
1277 || (__glibc_unlikely (l->l_flags_1 & DF_1_PIE)
1278 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0)))
1280 if (l->l_flags_1 & DF_1_PIE)
1281 errstring
1282 = N_("cannot dynamically load position-independent executable");
1283 else
1284 errstring = N_("shared object cannot be dlopen()ed");
1285 goto lose;
1288 if (l->l_phdr == NULL)
1290 /* The program header is not contained in any of the segments.
1291 We have to allocate memory ourself and copy it over from out
1292 temporary place. */
1293 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1294 * sizeof (ElfW(Phdr)));
1295 if (newp == NULL)
1297 errstring = N_("cannot allocate memory for program header");
1298 goto lose_errno;
1301 l->l_phdr = memcpy (newp, phdr,
1302 (header->e_phnum * sizeof (ElfW(Phdr))));
1303 l->l_phdr_allocated = 1;
1305 else
1306 /* Adjust the PT_PHDR value by the runtime load address. */
1307 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1309 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
1311 /* The stack is presently not executable, but this module
1312 requires that it be executable. We must change the
1313 protection of the variable which contains the flags used in
1314 the mprotect calls. */
1315 #ifdef SHARED
1316 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1318 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1319 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1321 struct link_map *const m = &GL(dl_rtld_map);
1322 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1323 + m->l_relro_size)
1324 & -GLRO(dl_pagesize));
1325 if (__glibc_likely (p + s <= relro_end))
1327 /* The variable lies in the region protected by RELRO. */
1328 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1330 errstring = N_("cannot change memory protections");
1331 goto lose_errno;
1333 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1334 __mprotect ((void *) p, s, PROT_READ);
1336 else
1337 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1339 else
1340 #endif
1341 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1343 #ifdef check_consistency
1344 check_consistency ();
1345 #endif
1347 #if PTHREAD_IN_LIBC
1348 errval = _dl_make_stacks_executable (stack_endp);
1349 #else
1350 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1351 #endif
1352 if (errval)
1354 errstring = N_("\
1355 cannot enable executable stack as shared object requires");
1356 goto lose;
1360 /* Adjust the address of the TLS initialization image. */
1361 if (l->l_tls_initimage != NULL)
1362 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1364 /* Process program headers again after load segments are mapped in
1365 case processing requires accessing those segments. Scan program
1366 headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY
1367 exits. */
1368 for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph)
1369 switch (ph[-1].p_type)
1371 case PT_NOTE:
1372 _dl_process_pt_note (l, fd, &ph[-1]);
1373 break;
1374 case PT_GNU_PROPERTY:
1375 _dl_process_pt_gnu_property (l, fd, &ph[-1]);
1376 break;
1379 /* We are done mapping in the file. We no longer need the descriptor. */
1380 if (__glibc_unlikely (__close_nocancel (fd) != 0))
1382 errstring = N_("cannot close file descriptor");
1383 goto lose_errno;
1385 /* Signal that we closed the file. */
1386 fd = -1;
1388 /* Failures before this point are handled locally via lose.
1389 There are no more failures in this function until return,
1390 to change that the cleanup handling needs to be updated. */
1392 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1393 assert (type != ET_EXEC || l->l_type == lt_executable);
1395 l->l_entry += l->l_addr;
1397 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1398 _dl_debug_printf ("\
1399 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*zx\n\
1400 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1401 (int) sizeof (void *) * 2,
1402 (unsigned long int) l->l_ld,
1403 (int) sizeof (void *) * 2,
1404 (unsigned long int) l->l_addr,
1405 (int) sizeof (void *) * 2, maplength,
1406 (int) sizeof (void *) * 2,
1407 (unsigned long int) l->l_entry,
1408 (int) sizeof (void *) * 2,
1409 (unsigned long int) l->l_phdr,
1410 (int) sizeof (void *) * 2, l->l_phnum);
1412 /* Set up the symbol hash table. */
1413 _dl_setup_hash (l);
1415 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1416 have to do this for the main map. */
1417 if ((mode & RTLD_DEEPBIND) == 0
1418 && __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
1419 && &l->l_searchlist != l->l_scope[0])
1421 /* Create an appropriate searchlist. It contains only this map.
1422 This is the definition of DT_SYMBOLIC in SysVr4. */
1423 l->l_symbolic_searchlist.r_list[0] = l;
1424 l->l_symbolic_searchlist.r_nlist = 1;
1426 /* Now move the existing entries one back. */
1427 memmove (&l->l_scope[1], &l->l_scope[0],
1428 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1430 /* Now add the new entry. */
1431 l->l_scope[0] = &l->l_symbolic_searchlist;
1434 /* Remember whether this object must be initialized first. */
1435 if (l->l_flags_1 & DF_1_INITFIRST)
1436 GL(dl_initfirst) = l;
1438 /* Finally the file information. */
1439 l->l_file_id = id;
1441 #ifdef SHARED
1442 /* When auditing is used the recorded names might not include the
1443 name by which the DSO is actually known. Add that as well. */
1444 if (__glibc_unlikely (origname != NULL))
1445 add_name_to_object (l, origname);
1446 #else
1447 /* Audit modules only exist when linking is dynamic so ORIGNAME
1448 cannot be non-NULL. */
1449 assert (origname == NULL);
1450 #endif
1452 /* When we profile the SONAME might be needed for something else but
1453 loading. Add it right away. */
1454 if (__glibc_unlikely (GLRO(dl_profile) != NULL)
1455 && l->l_info[DT_SONAME] != NULL)
1456 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1457 + l->l_info[DT_SONAME]->d_un.d_val));
1459 /* If we have newly loaded libc.so, update the namespace
1460 description. */
1461 if (GL(dl_ns)[nsid].libc_map == NULL
1462 && l->l_info[DT_SONAME] != NULL
1463 && strcmp (((const char *) D_PTR (l, l_info[DT_STRTAB])
1464 + l->l_info[DT_SONAME]->d_un.d_val), LIBC_SO) == 0)
1465 GL(dl_ns)[nsid].libc_map = l;
1467 /* _dl_close can only eventually undo the module ID assignment (via
1468 remove_slotinfo) if this function returns a pointer to a link
1469 map. Therefore, delay this step until all possibilities for
1470 failure have been excluded. */
1471 if (l->l_tls_blocksize > 0
1472 && (__glibc_likely (l->l_type == lt_library)
1473 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1474 not set up TLS data structures, so don't use them now. */
1475 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL)))
1476 /* Assign the next available module ID. */
1477 _dl_assign_tls_modid (l);
1479 #ifdef DL_AFTER_LOAD
1480 DL_AFTER_LOAD (l);
1481 #endif
1483 /* Now that the object is fully initialized add it to the object list. */
1484 _dl_add_to_namespace_list (l, nsid);
1486 /* Signal that we are going to add new objects. */
1487 struct r_debug *r = _dl_debug_update (nsid);
1488 if (r->r_state == RT_CONSISTENT)
1490 #ifdef SHARED
1491 /* Auditing checkpoint: we are going to add new objects. Since this
1492 is called after _dl_add_to_namespace_list the namespace is guaranteed
1493 to not be empty. */
1494 if ((mode & __RTLD_AUDIT) == 0)
1495 _dl_audit_activity_nsid (nsid, LA_ACT_ADD);
1496 #endif
1498 /* Notify the debugger we have added some objects. We need to
1499 call _dl_debug_initialize in a static program in case dynamic
1500 linking has not been used before. */
1501 r->r_state = RT_ADD;
1502 _dl_debug_state ();
1503 LIBC_PROBE (map_start, 2, nsid, r);
1505 else
1506 assert (r->r_state == RT_ADD);
1508 #ifdef SHARED
1509 /* Auditing checkpoint: we have a new object. */
1510 if (!GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1511 _dl_audit_objopen (l, nsid);
1512 #endif
1514 return l;
1517 /* Print search path. */
1518 static void
1519 print_search_path (struct r_search_path_elem **list,
1520 const char *what, const char *name)
1522 char buf[max_dirnamelen + max_capstrlen];
1523 int first = 1;
1525 _dl_debug_printf (" search path=");
1527 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1529 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1530 size_t cnt;
1532 for (cnt = 0; cnt < ncapstr; ++cnt)
1533 if ((*list)->status[cnt] != nonexisting)
1535 #ifdef SHARED
1536 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1537 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1538 cp[0] = '\0';
1539 else
1540 cp[-1] = '\0';
1541 #else
1542 *endp = '\0';
1543 #endif
1545 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1546 first = 0;
1549 ++list;
1552 if (name != NULL)
1553 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1554 DSO_FILENAME (name));
1555 else
1556 _dl_debug_printf_c ("\t\t(%s)\n", what);
1559 /* Open a file and verify it is an ELF file for this architecture. We
1560 ignore only ELF files for other architectures. Non-ELF files and
1561 ELF files with different header information cause fatal errors since
1562 this could mean there is something wrong in the installation and the
1563 user might want to know about this.
1565 If FD is not -1, then the file is already open and FD refers to it.
1566 In that case, FD is consumed for both successful and error returns. */
1567 static int
1568 open_verify (const char *name, int fd,
1569 struct filebuf *fbp, struct link_map *loader,
1570 int whatcode, int mode, bool *found_other_class, bool free_name)
1572 /* This is the expected ELF header. */
1573 #define ELF32_CLASS ELFCLASS32
1574 #define ELF64_CLASS ELFCLASS64
1575 #ifndef VALID_ELF_HEADER
1576 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1577 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1578 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1579 #elif defined MORE_ELF_HEADER_DATA
1580 MORE_ELF_HEADER_DATA;
1581 #endif
1582 static const unsigned char expected[EI_NIDENT] =
1584 [EI_MAG0] = ELFMAG0,
1585 [EI_MAG1] = ELFMAG1,
1586 [EI_MAG2] = ELFMAG2,
1587 [EI_MAG3] = ELFMAG3,
1588 [EI_CLASS] = ELFW(CLASS),
1589 [EI_DATA] = byteorder,
1590 [EI_VERSION] = EV_CURRENT,
1591 [EI_OSABI] = ELFOSABI_SYSV,
1592 [EI_ABIVERSION] = 0
1594 /* Initialize it to make the compiler happy. */
1595 const char *errstring = NULL;
1596 int errval = 0;
1598 #ifdef SHARED
1599 /* Give the auditing libraries a chance. */
1600 if (__glibc_unlikely (GLRO(dl_naudit) > 0))
1602 const char *original_name = name;
1603 name = _dl_audit_objsearch (name, loader, whatcode);
1604 if (name == NULL)
1605 return -1;
1607 if (fd != -1 && name != original_name && strcmp (name, original_name))
1609 /* An audit library changed what we're supposed to open,
1610 so FD no longer matches it. */
1611 __close_nocancel (fd);
1612 fd = -1;
1615 #endif
1617 if (fd == -1)
1618 /* Open the file. We always open files read-only. */
1619 fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
1621 if (fd != -1)
1623 ElfW(Ehdr) *ehdr;
1624 ElfW(Phdr) *phdr;
1625 size_t maplength;
1627 /* We successfully opened the file. Now verify it is a file
1628 we can use. */
1629 __set_errno (0);
1630 fbp->len = 0;
1631 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1632 /* Read in the header. */
1635 ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
1636 sizeof (fbp->buf) - fbp->len);
1637 if (retlen <= 0)
1638 break;
1639 fbp->len += retlen;
1641 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1643 /* This is where the ELF header is loaded. */
1644 ehdr = (ElfW(Ehdr) *) fbp->buf;
1646 /* Now run the tests. */
1647 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1649 errval = errno;
1650 errstring = (errval == 0
1651 ? N_("file too short") : N_("cannot read file data"));
1652 lose:
1653 if (free_name)
1655 char *realname = (char *) name;
1656 name = strdupa (realname);
1657 free (realname);
1659 __close_nocancel (fd);
1660 _dl_signal_error (errval, name, NULL, errstring);
1663 /* See whether the ELF header is what we expect. */
1664 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1665 EI_ABIVERSION)
1666 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1667 ehdr->e_ident[EI_ABIVERSION])
1668 || memcmp (&ehdr->e_ident[EI_PAD],
1669 &expected[EI_PAD],
1670 EI_NIDENT - EI_PAD) != 0))
1672 /* Something is wrong. */
1673 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1674 if (*magp !=
1675 #if BYTE_ORDER == LITTLE_ENDIAN
1676 ((ELFMAG0 << (EI_MAG0 * 8))
1677 | (ELFMAG1 << (EI_MAG1 * 8))
1678 | (ELFMAG2 << (EI_MAG2 * 8))
1679 | (ELFMAG3 << (EI_MAG3 * 8)))
1680 #else
1681 ((ELFMAG0 << (EI_MAG3 * 8))
1682 | (ELFMAG1 << (EI_MAG2 * 8))
1683 | (ELFMAG2 << (EI_MAG1 * 8))
1684 | (ELFMAG3 << (EI_MAG0 * 8)))
1685 #endif
1687 errstring = N_("invalid ELF header");
1689 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1691 /* This is not a fatal error. On architectures where
1692 32-bit and 64-bit binaries can be run this might
1693 happen. */
1694 *found_other_class = true;
1695 __close_nocancel (fd);
1696 __set_errno (ENOENT);
1697 return -1;
1699 else if (ehdr->e_ident[EI_DATA] != byteorder)
1701 if (BYTE_ORDER == BIG_ENDIAN)
1702 errstring = N_("ELF file data encoding not big-endian");
1703 else
1704 errstring = N_("ELF file data encoding not little-endian");
1706 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1707 errstring
1708 = N_("ELF file version ident does not match current one");
1709 /* XXX We should be able so set system specific versions which are
1710 allowed here. */
1711 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1712 errstring = N_("ELF file OS ABI invalid");
1713 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1714 ehdr->e_ident[EI_ABIVERSION]))
1715 errstring = N_("ELF file ABI version invalid");
1716 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1717 EI_NIDENT - EI_PAD) != 0)
1718 errstring = N_("nonzero padding in e_ident");
1719 else
1720 /* Otherwise we don't know what went wrong. */
1721 errstring = N_("internal error");
1723 goto lose;
1726 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1728 errstring = N_("ELF file version does not match current one");
1729 goto lose;
1731 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1733 __close_nocancel (fd);
1734 __set_errno (ENOENT);
1735 return -1;
1737 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1738 && ehdr->e_type != ET_EXEC))
1740 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1741 goto lose;
1743 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1745 errstring = N_("ELF file's phentsize not the expected size");
1746 goto lose;
1749 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1750 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1751 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1752 else
1754 phdr = alloca (maplength);
1755 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1756 ehdr->e_phoff) != maplength)
1758 errval = errno;
1759 errstring = N_("cannot read file data");
1760 goto lose;
1764 if (__glibc_unlikely (elf_machine_reject_phdr_p
1765 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1766 loader, fd)))
1768 __close_nocancel (fd);
1769 __set_errno (ENOENT);
1770 return -1;
1775 return fd;
1778 /* Try to open NAME in one of the directories in *DIRSP.
1779 Return the fd, or -1. If successful, fill in *REALNAME
1780 with the malloc'd full directory name. If it turns out
1781 that none of the directories in *DIRSP exists, *DIRSP is
1782 replaced with (void *) -1, and the old value is free()d
1783 if MAY_FREE_DIRS is true. */
1785 static int
1786 open_path (const char *name, size_t namelen, int mode,
1787 struct r_search_path_struct *sps, char **realname,
1788 struct filebuf *fbp, struct link_map *loader, int whatcode,
1789 bool *found_other_class)
1791 struct r_search_path_elem **dirs = sps->dirs;
1792 char *buf;
1793 int fd = -1;
1794 const char *current_what = NULL;
1795 int any = 0;
1797 if (__glibc_unlikely (dirs == NULL))
1798 /* We're called before _dl_init_paths when loading the main executable
1799 given on the command line when rtld is run directly. */
1800 return -1;
1802 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1805 struct r_search_path_elem *this_dir = *dirs;
1806 size_t buflen = 0;
1807 size_t cnt;
1808 char *edp;
1809 int here_any = 0;
1810 int err;
1812 /* If we are debugging the search for libraries print the path
1813 now if it hasn't happened now. */
1814 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1815 && current_what != this_dir->what)
1817 current_what = this_dir->what;
1818 print_search_path (dirs, current_what, this_dir->where);
1821 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1822 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1824 /* Skip this directory if we know it does not exist. */
1825 if (this_dir->status[cnt] == nonexisting)
1826 continue;
1828 #ifdef SHARED
1829 buflen =
1830 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1831 capstr[cnt].len),
1832 name, namelen)
1833 - buf);
1834 #else
1835 buflen = (char *) __mempcpy (edp, name, namelen) - buf;
1836 #endif
1838 /* Print name we try if this is wanted. */
1839 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1840 _dl_debug_printf (" trying file=%s\n", buf);
1842 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1843 found_other_class, false);
1844 if (this_dir->status[cnt] == unknown)
1846 if (fd != -1)
1847 this_dir->status[cnt] = existing;
1848 /* Do not update the directory information when loading
1849 auditing code. We must try to disturb the program as
1850 little as possible. */
1851 else if (loader == NULL
1852 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1854 /* We failed to open machine dependent library. Let's
1855 test whether there is any directory at all. */
1856 struct __stat64_t64 st;
1858 buf[buflen - namelen - 1] = '\0';
1860 if (__stat64_time64 (buf, &st) != 0
1861 || ! S_ISDIR (st.st_mode))
1862 /* The directory does not exist or it is no directory. */
1863 this_dir->status[cnt] = nonexisting;
1864 else
1865 this_dir->status[cnt] = existing;
1869 /* Remember whether we found any existing directory. */
1870 here_any |= this_dir->status[cnt] != nonexisting;
1872 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1873 && __libc_enable_secure)
1875 /* This is an extra security effort to make sure nobody can
1876 preload broken shared objects which are in the trusted
1877 directories and so exploit the bugs. */
1878 struct __stat64_t64 st;
1880 if (__fstat64_time64 (fd, &st) != 0
1881 || (st.st_mode & S_ISUID) == 0)
1883 /* The shared object cannot be tested for being SUID
1884 or this bit is not set. In this case we must not
1885 use this object. */
1886 __close_nocancel (fd);
1887 fd = -1;
1888 /* We simply ignore the file, signal this by setting
1889 the error value which would have been set by `open'. */
1890 errno = ENOENT;
1895 if (fd != -1)
1897 *realname = (char *) malloc (buflen);
1898 if (*realname != NULL)
1900 memcpy (*realname, buf, buflen);
1901 return fd;
1903 else
1905 /* No memory for the name, we certainly won't be able
1906 to load and link it. */
1907 __close_nocancel (fd);
1908 return -1;
1911 if (here_any && (err = errno) != ENOENT && err != EACCES)
1912 /* The file exists and is readable, but something went wrong. */
1913 return -1;
1915 /* Remember whether we found anything. */
1916 any |= here_any;
1918 while (*++dirs != NULL);
1920 /* Remove the whole path if none of the directories exists. */
1921 if (__glibc_unlikely (! any))
1923 /* Paths which were allocated using the minimal malloc() in ld.so
1924 must not be freed using the general free() in libc. */
1925 if (sps->malloced)
1926 free (sps->dirs);
1928 /* __rtld_search_dirs and __rtld_env_path_list are
1929 attribute_relro, therefore avoid writing to them. */
1930 if (sps != &__rtld_search_dirs && sps != &__rtld_env_path_list)
1931 sps->dirs = (void *) -1;
1934 return -1;
1937 /* Map in the shared object file NAME. */
1939 struct link_map *
1940 _dl_map_object (struct link_map *loader, const char *name,
1941 int type, int trace_mode, int mode, Lmid_t nsid)
1943 int fd;
1944 const char *origname = NULL;
1945 char *realname;
1946 char *name_copy;
1947 struct link_map *l;
1948 struct filebuf fb;
1950 assert (nsid >= 0);
1951 assert (nsid < GL(dl_nns));
1953 /* Look for this name among those already loaded. */
1954 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1956 /* If the requested name matches the soname of a loaded object,
1957 use that object. Elide this check for names that have not
1958 yet been opened. */
1959 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
1960 continue;
1961 if (!_dl_name_match_p (name, l))
1963 const char *soname;
1965 if (__glibc_likely (l->l_soname_added)
1966 || l->l_info[DT_SONAME] == NULL)
1967 continue;
1969 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1970 + l->l_info[DT_SONAME]->d_un.d_val);
1971 if (strcmp (name, soname) != 0)
1972 continue;
1974 /* We have a match on a new name -- cache it. */
1975 add_name_to_object (l, soname);
1976 l->l_soname_added = 1;
1979 /* We have a match. */
1980 return l;
1983 /* Display information if we are debugging. */
1984 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1985 && loader != NULL)
1986 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
1987 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1988 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1989 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
1991 #ifdef SHARED
1992 /* Give the auditing libraries a chance to change the name before we
1993 try anything. */
1994 if (__glibc_unlikely (GLRO(dl_naudit) > 0))
1996 const char *before = name;
1997 name = _dl_audit_objsearch (name, loader, LA_SER_ORIG);
1998 if (name == NULL)
2000 fd = -1;
2001 goto no_file;
2003 if (before != name && strcmp (before, name) != 0)
2004 origname = before;
2006 #endif
2008 /* Will be true if we found a DSO which is of the other ELF class. */
2009 bool found_other_class = false;
2011 if (strchr (name, '/') == NULL)
2013 /* Search for NAME in several places. */
2015 size_t namelen = strlen (name) + 1;
2017 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2018 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2020 fd = -1;
2022 /* When the object has the RUNPATH information we don't use any
2023 RPATHs. */
2024 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2026 /* This is the executable's map (if there is one). Make sure that
2027 we do not look at it twice. */
2028 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2029 bool did_main_map = false;
2031 /* First try the DT_RPATH of the dependent object that caused NAME
2032 to be loaded. Then that object's dependent, and on up. */
2033 for (l = loader; l; l = l->l_loader)
2034 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2036 fd = open_path (name, namelen, mode,
2037 &l->l_rpath_dirs,
2038 &realname, &fb, loader, LA_SER_RUNPATH,
2039 &found_other_class);
2040 if (fd != -1)
2041 break;
2043 did_main_map |= l == main_map;
2046 /* If dynamically linked, try the DT_RPATH of the executable
2047 itself. NB: we do this for lookups in any namespace. */
2048 if (fd == -1 && !did_main_map
2049 && main_map != NULL && main_map->l_type != lt_loaded
2050 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2051 "RPATH"))
2052 fd = open_path (name, namelen, mode,
2053 &main_map->l_rpath_dirs,
2054 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2055 &found_other_class);
2057 /* Also try DT_RUNPATH in the executable for LD_AUDIT dlopen
2058 call. */
2059 if (__glibc_unlikely (mode & __RTLD_AUDIT)
2060 && fd == -1 && !did_main_map
2061 && main_map != NULL && main_map->l_type != lt_loaded)
2063 struct r_search_path_struct l_rpath_dirs;
2064 l_rpath_dirs.dirs = NULL;
2065 if (cache_rpath (main_map, &l_rpath_dirs,
2066 DT_RUNPATH, "RUNPATH"))
2067 fd = open_path (name, namelen, mode, &l_rpath_dirs,
2068 &realname, &fb, loader ?: main_map,
2069 LA_SER_RUNPATH, &found_other_class);
2073 /* Try the LD_LIBRARY_PATH environment variable. */
2074 if (fd == -1 && __rtld_env_path_list.dirs != (void *) -1)
2075 fd = open_path (name, namelen, mode, &__rtld_env_path_list,
2076 &realname, &fb,
2077 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2078 LA_SER_LIBPATH, &found_other_class);
2080 /* Look at the RUNPATH information for this binary. */
2081 if (fd == -1 && loader != NULL
2082 && cache_rpath (loader, &loader->l_runpath_dirs,
2083 DT_RUNPATH, "RUNPATH"))
2084 fd = open_path (name, namelen, mode,
2085 &loader->l_runpath_dirs, &realname, &fb, loader,
2086 LA_SER_RUNPATH, &found_other_class);
2088 if (fd == -1)
2090 realname = _dl_sysdep_open_object (name, namelen, &fd);
2091 if (realname != NULL)
2093 fd = open_verify (realname, fd,
2094 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2095 LA_SER_CONFIG, mode, &found_other_class,
2096 false);
2097 if (fd == -1)
2098 free (realname);
2102 #ifdef USE_LDCONFIG
2103 if (fd == -1
2104 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2105 || ! __libc_enable_secure)
2106 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2108 /* Check the list of libraries in the file /etc/ld.so.cache,
2109 for compatibility with Linux's ldconfig program. */
2110 char *cached = _dl_load_cache_lookup (name);
2112 if (cached != NULL)
2114 // XXX Correct to unconditionally default to namespace 0?
2115 l = (loader
2116 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2117 # ifdef SHARED
2118 ?: &GL(dl_rtld_map)
2119 # endif
2122 /* If the loader has the DF_1_NODEFLIB flag set we must not
2123 use a cache entry from any of these directories. */
2124 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2126 const char *dirp = system_dirs;
2127 unsigned int cnt = 0;
2131 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2133 /* The prefix matches. Don't use the entry. */
2134 free (cached);
2135 cached = NULL;
2136 break;
2139 dirp += system_dirs_len[cnt] + 1;
2140 ++cnt;
2142 while (cnt < nsystem_dirs_len);
2145 if (cached != NULL)
2147 fd = open_verify (cached, -1,
2148 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2149 LA_SER_CONFIG, mode, &found_other_class,
2150 false);
2151 if (__glibc_likely (fd != -1))
2152 realname = cached;
2153 else
2154 free (cached);
2158 #endif
2160 /* Finally, try the default path. */
2161 if (fd == -1
2162 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2163 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2164 && __rtld_search_dirs.dirs != (void *) -1)
2165 fd = open_path (name, namelen, mode, &__rtld_search_dirs,
2166 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2168 /* Add another newline when we are tracing the library loading. */
2169 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2170 _dl_debug_printf ("\n");
2172 else
2174 /* The path may contain dynamic string tokens. */
2175 realname = (loader
2176 ? expand_dynamic_string_token (loader, name)
2177 : __strdup (name));
2178 if (realname == NULL)
2179 fd = -1;
2180 else
2182 fd = open_verify (realname, -1, &fb,
2183 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2184 &found_other_class, true);
2185 if (__glibc_unlikely (fd == -1))
2186 free (realname);
2190 #ifdef SHARED
2191 no_file:
2192 #endif
2193 /* In case the LOADER information has only been provided to get to
2194 the appropriate RUNPATH/RPATH information we do not need it
2195 anymore. */
2196 if (mode & __RTLD_CALLMAP)
2197 loader = NULL;
2199 if (__glibc_unlikely (fd == -1))
2201 if (trace_mode)
2203 /* We haven't found an appropriate library. But since we
2204 are only interested in the list of libraries this isn't
2205 so severe. Fake an entry with all the information we
2206 have. */
2207 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2209 /* Allocate a new object map. */
2210 if ((name_copy = __strdup (name)) == NULL
2211 || (l = _dl_new_object (name_copy, name, type, loader,
2212 mode, nsid)) == NULL)
2214 free (name_copy);
2215 _dl_signal_error (ENOMEM, name, NULL,
2216 N_("cannot create shared object descriptor"));
2218 /* Signal that this is a faked entry. */
2219 l->l_faked = 1;
2220 /* Since the descriptor is initialized with zero we do not
2221 have do this here.
2222 l->l_reserved = 0; */
2223 l->l_buckets = &dummy_bucket;
2224 l->l_nbuckets = 1;
2225 l->l_relocated = 1;
2227 /* Enter the object in the object list. */
2228 _dl_add_to_namespace_list (l, nsid);
2230 return l;
2232 else if (found_other_class)
2233 _dl_signal_error (0, name, NULL,
2234 ELFW(CLASS) == ELFCLASS32
2235 ? N_("wrong ELF class: ELFCLASS64")
2236 : N_("wrong ELF class: ELFCLASS32"));
2237 else
2238 _dl_signal_error (errno, name, NULL,
2239 N_("cannot open shared object file"));
2242 void *stack_end = __libc_stack_end;
2243 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2244 type, mode, &stack_end, nsid);
2247 struct add_path_state
2249 bool counting;
2250 unsigned int idx;
2251 Dl_serinfo *si;
2252 char *allocptr;
2255 static void
2256 add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2257 unsigned int flags)
2259 if (sps->dirs != (void *) -1)
2261 struct r_search_path_elem **dirs = sps->dirs;
2264 const struct r_search_path_elem *const r = *dirs++;
2265 if (p->counting)
2267 p->si->dls_cnt++;
2268 p->si->dls_size += MAX (2, r->dirnamelen);
2270 else
2272 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2273 sp->dls_name = p->allocptr;
2274 if (r->dirnamelen < 2)
2275 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2276 else
2277 p->allocptr = __mempcpy (p->allocptr,
2278 r->dirname, r->dirnamelen - 1);
2279 *p->allocptr++ = '\0';
2280 sp->dls_flags = flags;
2283 while (*dirs != NULL);
2287 void
2288 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2290 if (counting)
2292 si->dls_cnt = 0;
2293 si->dls_size = 0;
2296 struct add_path_state p =
2298 .counting = counting,
2299 .idx = 0,
2300 .si = si,
2301 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2304 # define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2306 /* When the object has the RUNPATH information we don't use any RPATHs. */
2307 if (loader->l_info[DT_RUNPATH] == NULL)
2309 /* First try the DT_RPATH of the dependent object that caused NAME
2310 to be loaded. Then that object's dependent, and on up. */
2312 struct link_map *l = loader;
2315 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2316 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2317 l = l->l_loader;
2319 while (l != NULL);
2321 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2322 if (loader->l_ns == LM_ID_BASE)
2324 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2325 if (l != NULL && l->l_type != lt_loaded && l != loader)
2326 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2327 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2331 /* Try the LD_LIBRARY_PATH environment variable. */
2332 add_path (&p, &__rtld_env_path_list, XXX_ENV);
2334 /* Look at the RUNPATH information for this binary. */
2335 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2336 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2338 /* XXX
2339 Here is where ld.so.cache gets checked, but we don't have
2340 a way to indicate that in the results for Dl_serinfo. */
2342 /* Finally, try the default path. */
2343 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2344 add_path (&p, &__rtld_search_dirs, XXX_default);
2346 if (counting)
2347 /* Count the struct size before the string area, which we didn't
2348 know before we completed dls_cnt. */
2349 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;