powerpc: Add optimized strlen for POWER10
[glibc.git] / elf / dl-load.c
blob2832ab354059da5f1f83bd033c965779142dfc20
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
19 #include <elf.h>
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <libintl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <ldsodefs.h>
28 #include <bits/wordsize.h>
29 #include <sys/mman.h>
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include <gnu/lib-names.h>
35 /* Type for the buffer we put the ELF header and hopefully the program
36 header. This buffer does not really have to be too large. In most
37 cases the program header follows the ELF header directly. If this
38 is not the case all bets are off and we can make the header
39 arbitrarily large and still won't get it read. This means the only
40 question is how large are the ELF and program header combined. The
41 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
42 bytes long. Each program header entry is again 32 and 56 bytes
43 long respectively. I.e., even with a file which has 10 program
44 header entries we only have to read 372B/624B respectively. Add to
45 this a bit of margin for program notes and reading 512B and 832B
46 for 32-bit and 64-bit files respecitvely is enough. If this
47 heuristic should really fail for some file the code in
48 `_dl_map_object_from_fd' knows how to recover. */
49 struct filebuf
51 ssize_t len;
52 #if __WORDSIZE == 32
53 # define FILEBUF_SIZE 512
54 #else
55 # define FILEBUF_SIZE 832
56 #endif
57 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
60 #include "dynamic-link.h"
61 #include <abi-tag.h>
62 #include <stackinfo.h>
63 #include <sysdep.h>
64 #include <stap-probe.h>
65 #include <libc-pointer-arith.h>
66 #include <array_length.h>
68 #include <dl-dst.h>
69 #include <dl-load.h>
70 #include <dl-map-segments.h>
71 #include <dl-unmap-segments.h>
72 #include <dl-machine-reject-phdr.h>
73 #include <dl-sysdep-open.h>
74 #include <dl-prop.h>
75 #include <not-cancel.h>
77 #include <endian.h>
78 #if BYTE_ORDER == BIG_ENDIAN
79 # define byteorder ELFDATA2MSB
80 #elif BYTE_ORDER == LITTLE_ENDIAN
81 # define byteorder ELFDATA2LSB
82 #else
83 # error "Unknown BYTE_ORDER " BYTE_ORDER
84 # define byteorder ELFDATANONE
85 #endif
87 #define STRING(x) __STRING (x)
90 int __stack_prot attribute_hidden attribute_relro
91 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
92 = PROT_GROWSDOWN;
93 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
94 = PROT_GROWSUP;
95 #else
96 = 0;
97 #endif
100 /* This is the decomposed LD_LIBRARY_PATH search path. */
101 struct r_search_path_struct __rtld_env_path_list attribute_relro;
103 /* List of the hardware capabilities we might end up using. */
104 #ifdef SHARED
105 static const struct r_strlenpair *capstr attribute_relro;
106 static size_t ncapstr attribute_relro;
107 static size_t max_capstrlen attribute_relro;
108 #else
109 enum { ncapstr = 1, max_capstrlen = 0 };
110 #endif
113 /* Get the generated information about the trusted directories. Use
114 an array of concatenated strings to avoid relocations. See
115 gen-trusted-dirs.awk. */
116 #include "trusted-dirs.h"
118 static const char system_dirs[] = SYSTEM_DIRS;
119 static const size_t system_dirs_len[] =
121 SYSTEM_DIRS_LEN
123 #define nsystem_dirs_len array_length (system_dirs_len)
125 static bool
126 is_trusted_path_normalize (const char *path, size_t len)
128 if (len == 0)
129 return false;
131 char *npath = (char *) alloca (len + 2);
132 char *wnp = npath;
133 while (*path != '\0')
135 if (path[0] == '/')
137 if (path[1] == '.')
139 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
141 while (wnp > npath && *--wnp != '/')
143 path += 3;
144 continue;
146 else if (path[2] == '/' || path[2] == '\0')
148 path += 2;
149 continue;
153 if (wnp > npath && wnp[-1] == '/')
155 ++path;
156 continue;
160 *wnp++ = *path++;
163 if (wnp == npath || wnp[-1] != '/')
164 *wnp++ = '/';
166 const char *trun = system_dirs;
168 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
170 if (wnp - npath >= system_dirs_len[idx]
171 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
172 /* Found it. */
173 return true;
175 trun += system_dirs_len[idx] + 1;
178 return false;
181 /* Given a substring starting at INPUT, just after the DST '$' start
182 token, determine if INPUT contains DST token REF, following the
183 ELF gABI rules for DSTs:
185 * Longest possible sequence using the rules (greedy).
187 * Must start with a $ (enforced by caller).
189 * Must follow $ with one underscore or ASCII [A-Za-z] (caller
190 follows these rules for REF) or '{' (start curly quoted name).
192 * Must follow first two characters with zero or more [A-Za-z0-9_]
193 (enforced by caller) or '}' (end curly quoted name).
195 If the sequence is a DST matching REF then the length of the DST
196 (excluding the $ sign but including curly braces, if any) is
197 returned, otherwise 0. */
198 static size_t
199 is_dst (const char *input, const char *ref)
201 bool is_curly = false;
203 /* Is a ${...} input sequence? */
204 if (input[0] == '{')
206 is_curly = true;
207 ++input;
210 /* Check for matching name, following closing curly brace (if
211 required), or trailing characters which are part of an
212 identifier. */
213 size_t rlen = strlen (ref);
214 if (strncmp (input, ref, rlen) != 0
215 || (is_curly && input[rlen] != '}')
216 || ((input[rlen] >= 'A' && input[rlen] <= 'Z')
217 || (input[rlen] >= 'a' && input[rlen] <= 'z')
218 || (input[rlen] >= '0' && input[rlen] <= '9')
219 || (input[rlen] == '_')))
220 return 0;
222 if (is_curly)
223 /* Count the two curly braces. */
224 return rlen + 2;
225 else
226 return rlen;
229 /* INPUT should be the start of a path e.g DT_RPATH or name e.g.
230 DT_NEEDED. The return value is the number of known DSTs found. We
231 count all known DSTs regardless of __libc_enable_secure; the caller
232 is responsible for enforcing the security of the substitution rules
233 (usually _dl_dst_substitute). */
234 size_t
235 _dl_dst_count (const char *input)
237 size_t cnt = 0;
239 input = strchr (input, '$');
241 /* Most likely there is no DST. */
242 if (__glibc_likely (input == NULL))
243 return 0;
247 size_t len;
249 ++input;
250 /* All DSTs must follow ELF gABI rules, see is_dst (). */
251 if ((len = is_dst (input, "ORIGIN")) != 0
252 || (len = is_dst (input, "PLATFORM")) != 0
253 || (len = is_dst (input, "LIB")) != 0)
254 ++cnt;
256 /* There may be more than one DST in the input. */
257 input = strchr (input + len, '$');
259 while (input != NULL);
261 return cnt;
264 /* Process INPUT for DSTs and store in RESULT using the information
265 from link map L to resolve the DSTs. This function only handles one
266 path at a time and does not handle colon-separated path lists (see
267 fillin_rpath ()). Lastly the size of result in bytes should be at
268 least equal to the value returned by DL_DST_REQUIRED. Note that it
269 is possible for a DT_NEEDED, DT_AUXILIARY, and DT_FILTER entries to
270 have colons, but we treat those as literal colons here, not as path
271 list delimeters. */
272 char *
273 _dl_dst_substitute (struct link_map *l, const char *input, char *result)
275 /* Copy character-by-character from input into the working pointer
276 looking for any DSTs. We track the start of input and if we are
277 going to check for trusted paths, all of which are part of $ORIGIN
278 handling in SUID/SGID cases (see below). In some cases, like when
279 a DST cannot be replaced, we may set result to an empty string and
280 return. */
281 char *wp = result;
282 const char *start = input;
283 bool check_for_trusted = false;
287 if (__glibc_unlikely (*input == '$'))
289 const char *repl = NULL;
290 size_t len;
292 ++input;
293 if ((len = is_dst (input, "ORIGIN")) != 0)
295 /* For SUID/GUID programs we normally ignore the path with
296 $ORIGIN in DT_RUNPATH, or DT_RPATH. However, there is
297 one exception to this rule, and it is:
299 * $ORIGIN appears as the first path element, and is
300 the only string in the path or is immediately
301 followed by a path separator and the rest of the
302 path,
304 and ...
306 * The path is rooted in a trusted directory.
308 This exception allows such programs to reference
309 shared libraries in subdirectories of trusted
310 directories. The use case is one of general
311 organization and deployment flexibility.
312 Trusted directories are usually such paths as "/lib64"
313 or "/usr/lib64", and the usual RPATHs take the form of
314 [$ORIGIN/../$LIB/somedir]. */
315 if (__glibc_unlikely (__libc_enable_secure)
316 && !(input == start + 1
317 && (input[len] == '\0' || input[len] == '/')))
318 repl = (const char *) -1;
319 else
320 repl = l->l_origin;
322 check_for_trusted = (__libc_enable_secure
323 && l->l_type == lt_executable);
325 else if ((len = is_dst (input, "PLATFORM")) != 0)
326 repl = GLRO(dl_platform);
327 else if ((len = is_dst (input, "LIB")) != 0)
328 repl = DL_DST_LIB;
330 if (repl != NULL && repl != (const char *) -1)
332 wp = __stpcpy (wp, repl);
333 input += len;
335 else if (len != 0)
337 /* We found a valid DST that we know about, but we could
338 not find a replacement value for it, therefore we
339 cannot use this path and discard it. */
340 *result = '\0';
341 return result;
343 else
344 /* No DST we recognize. */
345 *wp++ = '$';
347 else
349 *wp++ = *input++;
352 while (*input != '\0');
354 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
355 path must be rooted in one of the trusted directories. The $LIB
356 and $PLATFORM DST cannot in any way be manipulated by the caller
357 because they are fixed values that are set by the dynamic loader
358 and therefore any paths using just $LIB or $PLATFORM need not be
359 checked for trust, the authors of the binaries themselves are
360 trusted to have designed this correctly. Only $ORIGIN is tested in
361 this way because it may be manipulated in some ways with hard
362 links. */
363 if (__glibc_unlikely (check_for_trusted)
364 && !is_trusted_path_normalize (result, wp - result))
366 *result = '\0';
367 return result;
370 *wp = '\0';
372 return result;
376 /* Return a malloc allocated copy of INPUT with all recognized DSTs
377 replaced. On some platforms it might not be possible to determine the
378 path from which the object belonging to the map is loaded. In this
379 case the path containing the DST is left out. On error NULL
380 is returned. */
381 static char *
382 expand_dynamic_string_token (struct link_map *l, const char *input)
384 /* We make two runs over the string. First we determine how large the
385 resulting string is and then we copy it over. Since this is no
386 frequently executed operation we are looking here not for performance
387 but rather for code size. */
388 size_t cnt;
389 size_t total;
390 char *result;
392 /* Determine the number of DSTs. */
393 cnt = _dl_dst_count (input);
395 /* If we do not have to replace anything simply copy the string. */
396 if (__glibc_likely (cnt == 0))
397 return __strdup (input);
399 /* Determine the length of the substituted string. */
400 total = DL_DST_REQUIRED (l, input, strlen (input), cnt);
402 /* Allocate the necessary memory. */
403 result = (char *) malloc (total + 1);
404 if (result == NULL)
405 return NULL;
407 return _dl_dst_substitute (l, input, result);
411 /* Add `name' to the list of names for a particular shared object.
412 `name' is expected to have been allocated with malloc and will
413 be freed if the shared object already has this name.
414 Returns false if the object already had this name. */
415 static void
416 add_name_to_object (struct link_map *l, const char *name)
418 struct libname_list *lnp, *lastp;
419 struct libname_list *newname;
420 size_t name_len;
422 lastp = NULL;
423 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
424 if (strcmp (name, lnp->name) == 0)
425 return;
427 name_len = strlen (name) + 1;
428 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
429 if (newname == NULL)
431 /* No more memory. */
432 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
433 return;
435 /* The object should have a libname set from _dl_new_object. */
436 assert (lastp != NULL);
438 newname->name = memcpy (newname + 1, name, name_len);
439 newname->next = NULL;
440 newname->dont_free = 0;
441 /* CONCURRENCY NOTES:
443 Make sure the initialization of newname happens before its address is
444 read from the lastp->next store below.
446 GL(dl_load_lock) is held here (and by other writers, e.g. dlclose), so
447 readers of libname_list->next (e.g. _dl_check_caller or the reads above)
448 can use that for synchronization, however the read in _dl_name_match_p
449 may be executed without holding the lock during _dl_runtime_resolve
450 (i.e. lazy symbol resolution when a function of library l is called).
452 The release MO store below synchronizes with the acquire MO load in
453 _dl_name_match_p. Other writes need to synchronize with that load too,
454 however those happen either early when the process is single threaded
455 (dl_main) or when the library is unloaded (dlclose) and the user has to
456 synchronize library calls with unloading. */
457 atomic_store_release (&lastp->next, newname);
460 /* Standard search directories. */
461 struct r_search_path_struct __rtld_search_dirs attribute_relro;
463 static size_t max_dirnamelen;
465 static struct r_search_path_elem **
466 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
467 const char *what, const char *where, struct link_map *l)
469 char *cp;
470 size_t nelems = 0;
472 while ((cp = __strsep (&rpath, sep)) != NULL)
474 struct r_search_path_elem *dirp;
475 char *to_free = NULL;
476 size_t len = 0;
478 /* `strsep' can pass an empty string. */
479 if (*cp != '\0')
481 to_free = cp = expand_dynamic_string_token (l, cp);
483 /* expand_dynamic_string_token can return NULL in case of empty
484 path or memory allocation failure. */
485 if (cp == NULL)
486 continue;
488 /* Compute the length after dynamic string token expansion and
489 ignore empty paths. */
490 len = strlen (cp);
491 if (len == 0)
493 free (to_free);
494 continue;
497 /* Remove trailing slashes (except for "/"). */
498 while (len > 1 && cp[len - 1] == '/')
499 --len;
501 /* Now add one if there is none so far. */
502 if (len > 0 && cp[len - 1] != '/')
503 cp[len++] = '/';
506 /* See if this directory is already known. */
507 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
508 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
509 break;
511 if (dirp != NULL)
513 /* It is available, see whether it's on our own list. */
514 size_t cnt;
515 for (cnt = 0; cnt < nelems; ++cnt)
516 if (result[cnt] == dirp)
517 break;
519 if (cnt == nelems)
520 result[nelems++] = dirp;
522 else
524 size_t cnt;
525 enum r_dir_status init_val;
526 size_t where_len = where ? strlen (where) + 1 : 0;
528 /* It's a new directory. Create an entry and add it. */
529 dirp = (struct r_search_path_elem *)
530 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
531 + where_len + len + 1);
532 if (dirp == NULL)
533 _dl_signal_error (ENOMEM, NULL, NULL,
534 N_("cannot create cache for search path"));
536 dirp->dirname = ((char *) dirp + sizeof (*dirp)
537 + ncapstr * sizeof (enum r_dir_status));
538 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
539 dirp->dirnamelen = len;
541 if (len > max_dirnamelen)
542 max_dirnamelen = len;
544 /* We have to make sure all the relative directories are
545 never ignored. The current directory might change and
546 all our saved information would be void. */
547 init_val = cp[0] != '/' ? existing : unknown;
548 for (cnt = 0; cnt < ncapstr; ++cnt)
549 dirp->status[cnt] = init_val;
551 dirp->what = what;
552 if (__glibc_likely (where != NULL))
553 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
554 + (ncapstr * sizeof (enum r_dir_status)),
555 where, where_len);
556 else
557 dirp->where = NULL;
559 dirp->next = GL(dl_all_dirs);
560 GL(dl_all_dirs) = dirp;
562 /* Put it in the result array. */
563 result[nelems++] = dirp;
565 free (to_free);
568 /* Terminate the array. */
569 result[nelems] = NULL;
571 return result;
575 static bool
576 decompose_rpath (struct r_search_path_struct *sps,
577 const char *rpath, struct link_map *l, const char *what)
579 /* Make a copy we can work with. */
580 const char *where = l->l_name;
581 char *cp;
582 struct r_search_path_elem **result;
583 size_t nelems;
584 /* Initialize to please the compiler. */
585 const char *errstring = NULL;
587 /* First see whether we must forget the RUNPATH and RPATH from this
588 object. */
589 if (__glibc_unlikely (GLRO(dl_inhibit_rpath) != NULL)
590 && !__libc_enable_secure)
592 const char *inhp = GLRO(dl_inhibit_rpath);
596 const char *wp = where;
598 while (*inhp == *wp && *wp != '\0')
600 ++inhp;
601 ++wp;
604 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
606 /* This object is on the list of objects for which the
607 RUNPATH and RPATH must not be used. */
608 sps->dirs = (void *) -1;
609 return false;
612 while (*inhp != '\0')
613 if (*inhp++ == ':')
614 break;
616 while (*inhp != '\0');
619 /* Ignore empty rpaths. */
620 if (*rpath == '\0')
622 sps->dirs = (struct r_search_path_elem **) -1;
623 return false;
626 /* Make a writable copy. */
627 char *copy = __strdup (rpath);
628 if (copy == NULL)
630 errstring = N_("cannot create RUNPATH/RPATH copy");
631 goto signal_error;
634 /* Count the number of necessary elements in the result array. */
635 nelems = 0;
636 for (cp = copy; *cp != '\0'; ++cp)
637 if (*cp == ':')
638 ++nelems;
640 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
641 number of necessary entries. */
642 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
643 * sizeof (*result));
644 if (result == NULL)
646 free (copy);
647 errstring = N_("cannot create cache for search path");
648 signal_error:
649 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
652 fillin_rpath (copy, result, ":", what, where, l);
654 /* Free the copied RPATH string. `fillin_rpath' make own copies if
655 necessary. */
656 free (copy);
658 /* There is no path after expansion. */
659 if (result[0] == NULL)
661 free (result);
662 sps->dirs = (struct r_search_path_elem **) -1;
663 return false;
666 sps->dirs = result;
667 /* The caller will change this value if we haven't used a real malloc. */
668 sps->malloced = 1;
669 return true;
672 /* Make sure cached path information is stored in *SP
673 and return true if there are any paths to search there. */
674 static bool
675 cache_rpath (struct link_map *l,
676 struct r_search_path_struct *sp,
677 int tag,
678 const char *what)
680 if (sp->dirs == (void *) -1)
681 return false;
683 if (sp->dirs != NULL)
684 return true;
686 if (l->l_info[tag] == NULL)
688 /* There is no path. */
689 sp->dirs = (void *) -1;
690 return false;
693 /* Make sure the cache information is available. */
694 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
695 + l->l_info[tag]->d_un.d_val),
696 l, what);
700 void
701 _dl_init_paths (const char *llp, const char *source,
702 const char *glibc_hwcaps_prepend,
703 const char *glibc_hwcaps_mask)
705 size_t idx;
706 const char *strp;
707 struct r_search_path_elem *pelem, **aelem;
708 size_t round_size;
709 struct link_map __attribute__ ((unused)) *l = NULL;
710 /* Initialize to please the compiler. */
711 const char *errstring = NULL;
713 /* Fill in the information about the application's RPATH and the
714 directories addressed by the LD_LIBRARY_PATH environment variable. */
716 #ifdef SHARED
717 /* Get the capabilities. */
718 capstr = _dl_important_hwcaps (glibc_hwcaps_prepend, glibc_hwcaps_mask,
719 &ncapstr, &max_capstrlen);
720 #endif
722 /* First set up the rest of the default search directory entries. */
723 aelem = __rtld_search_dirs.dirs = (struct r_search_path_elem **)
724 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
725 if (__rtld_search_dirs.dirs == NULL)
727 errstring = N_("cannot create search path array");
728 signal_error:
729 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
732 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
733 + ncapstr * sizeof (enum r_dir_status))
734 / sizeof (struct r_search_path_elem));
736 __rtld_search_dirs.dirs[0]
737 = malloc (nsystem_dirs_len * round_size
738 * sizeof (*__rtld_search_dirs.dirs[0]));
739 if (__rtld_search_dirs.dirs[0] == NULL)
741 errstring = N_("cannot create cache for search path");
742 goto signal_error;
745 __rtld_search_dirs.malloced = 0;
746 pelem = GL(dl_all_dirs) = __rtld_search_dirs.dirs[0];
747 strp = system_dirs;
748 idx = 0;
752 size_t cnt;
754 *aelem++ = pelem;
756 pelem->what = "system search path";
757 pelem->where = NULL;
759 pelem->dirname = strp;
760 pelem->dirnamelen = system_dirs_len[idx];
761 strp += system_dirs_len[idx] + 1;
763 /* System paths must be absolute. */
764 assert (pelem->dirname[0] == '/');
765 for (cnt = 0; cnt < ncapstr; ++cnt)
766 pelem->status[cnt] = unknown;
768 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
770 pelem += round_size;
772 while (idx < nsystem_dirs_len);
774 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
775 *aelem = NULL;
777 /* This points to the map of the main object. If there is no main
778 object (e.g., under --help, use the dynamic loader itself as a
779 stand-in. */
780 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
781 #ifdef SHARED
782 if (l == NULL)
783 l = &GL (dl_rtld_map);
784 #endif
785 assert (l->l_type != lt_loaded);
787 if (l->l_info[DT_RUNPATH])
789 /* Allocate room for the search path and fill in information
790 from RUNPATH. */
791 decompose_rpath (&l->l_runpath_dirs,
792 (const void *) (D_PTR (l, l_info[DT_STRTAB])
793 + l->l_info[DT_RUNPATH]->d_un.d_val),
794 l, "RUNPATH");
795 /* During rtld init the memory is allocated by the stub malloc,
796 prevent any attempt to free it by the normal malloc. */
797 l->l_runpath_dirs.malloced = 0;
799 /* The RPATH is ignored. */
800 l->l_rpath_dirs.dirs = (void *) -1;
802 else
804 l->l_runpath_dirs.dirs = (void *) -1;
806 if (l->l_info[DT_RPATH])
808 /* Allocate room for the search path and fill in information
809 from RPATH. */
810 decompose_rpath (&l->l_rpath_dirs,
811 (const void *) (D_PTR (l, l_info[DT_STRTAB])
812 + l->l_info[DT_RPATH]->d_un.d_val),
813 l, "RPATH");
814 /* During rtld init the memory is allocated by the stub
815 malloc, prevent any attempt to free it by the normal
816 malloc. */
817 l->l_rpath_dirs.malloced = 0;
819 else
820 l->l_rpath_dirs.dirs = (void *) -1;
823 if (llp != NULL && *llp != '\0')
825 char *llp_tmp = strdupa (llp);
827 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
828 elements it has. */
829 size_t nllp = 1;
830 for (const char *cp = llp_tmp; *cp != '\0'; ++cp)
831 if (*cp == ':' || *cp == ';')
832 ++nllp;
834 __rtld_env_path_list.dirs = (struct r_search_path_elem **)
835 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
836 if (__rtld_env_path_list.dirs == NULL)
838 errstring = N_("cannot create cache for search path");
839 goto signal_error;
842 (void) fillin_rpath (llp_tmp, __rtld_env_path_list.dirs, ":;",
843 source, NULL, l);
845 if (__rtld_env_path_list.dirs[0] == NULL)
847 free (__rtld_env_path_list.dirs);
848 __rtld_env_path_list.dirs = (void *) -1;
851 __rtld_env_path_list.malloced = 0;
853 else
854 __rtld_env_path_list.dirs = (void *) -1;
858 /* Process PT_GNU_PROPERTY program header PH in module L after
859 PT_LOAD segments are mapped. Only one NT_GNU_PROPERTY_TYPE_0
860 note is handled which contains processor specific properties.
861 FD is -1 for the kernel mapped main executable otherwise it is
862 the fd used for loading module L. */
864 void
865 _dl_process_pt_gnu_property (struct link_map *l, int fd, const ElfW(Phdr) *ph)
867 const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
868 const ElfW(Addr) size = ph->p_memsz;
869 const ElfW(Addr) align = ph->p_align;
871 /* The NT_GNU_PROPERTY_TYPE_0 note must be aligned to 4 bytes in
872 32-bit objects and to 8 bytes in 64-bit objects. Skip notes
873 with incorrect alignment. */
874 if (align != (__ELF_NATIVE_CLASS / 8))
875 return;
877 const ElfW(Addr) start = (ElfW(Addr)) note;
878 unsigned int last_type = 0;
880 while ((ElfW(Addr)) (note + 1) - start < size)
882 /* Find the NT_GNU_PROPERTY_TYPE_0 note. */
883 if (note->n_namesz == 4
884 && note->n_type == NT_GNU_PROPERTY_TYPE_0
885 && memcmp (note + 1, "GNU", 4) == 0)
887 /* Check for invalid property. */
888 if (note->n_descsz < 8
889 || (note->n_descsz % sizeof (ElfW(Addr))) != 0)
890 return;
892 /* Start and end of property array. */
893 unsigned char *ptr = (unsigned char *) (note + 1) + 4;
894 unsigned char *ptr_end = ptr + note->n_descsz;
898 unsigned int type = *(unsigned int *) ptr;
899 unsigned int datasz = *(unsigned int *) (ptr + 4);
901 /* Property type must be in ascending order. */
902 if (type < last_type)
903 return;
905 ptr += 8;
906 if ((ptr + datasz) > ptr_end)
907 return;
909 last_type = type;
911 /* Target specific property processing. */
912 if (_dl_process_gnu_property (l, fd, type, datasz, ptr) == 0)
913 return;
915 /* Check the next property item. */
916 ptr += ALIGN_UP (datasz, sizeof (ElfW(Addr)));
918 while ((ptr_end - ptr) >= 8);
920 /* Only handle one NT_GNU_PROPERTY_TYPE_0. */
921 return;
924 note = ((const void *) note
925 + ELF_NOTE_NEXT_OFFSET (note->n_namesz, note->n_descsz,
926 align));
931 /* Map in the shared object NAME, actually located in REALNAME, and already
932 opened on FD. */
934 #ifndef EXTERNAL_MAP_FROM_FD
935 static
936 #endif
937 struct link_map *
938 _dl_map_object_from_fd (const char *name, const char *origname, int fd,
939 struct filebuf *fbp, char *realname,
940 struct link_map *loader, int l_type, int mode,
941 void **stack_endp, Lmid_t nsid)
943 struct link_map *l = NULL;
944 const ElfW(Ehdr) *header;
945 const ElfW(Phdr) *phdr;
946 const ElfW(Phdr) *ph;
947 size_t maplength;
948 int type;
949 /* Initialize to keep the compiler happy. */
950 const char *errstring = NULL;
951 int errval = 0;
952 struct r_debug *r = _dl_debug_initialize (0, nsid);
953 bool make_consistent = false;
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);
986 if (make_consistent && r != NULL)
988 r->r_state = RT_CONSISTENT;
989 _dl_debug_state ();
990 LIBC_PROBE (map_failed, 2, nsid, r);
993 _dl_signal_error (errval, name, NULL, errstring);
996 /* Look again to see if the real name matched another already loaded. */
997 for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
998 if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
1000 /* The object is already loaded.
1001 Just bump its reference count and return it. */
1002 __close_nocancel (fd);
1004 /* If the name is not in the list of names for this object add
1005 it. */
1006 free (realname);
1007 add_name_to_object (l, name);
1009 return l;
1013 #ifdef SHARED
1014 /* When loading into a namespace other than the base one we must
1015 avoid loading ld.so since there can only be one copy. Ever. */
1016 if (__glibc_unlikely (nsid != LM_ID_BASE)
1017 && (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
1018 || _dl_name_match_p (name, &GL(dl_rtld_map))))
1020 /* This is indeed ld.so. Create a new link_map which refers to
1021 the real one for almost everything. */
1022 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1023 if (l == NULL)
1024 goto fail_new;
1026 /* Refer to the real descriptor. */
1027 l->l_real = &GL(dl_rtld_map);
1029 /* No need to bump the refcount of the real object, ld.so will
1030 never be unloaded. */
1031 __close_nocancel (fd);
1033 /* Add the map for the mirrored object to the object list. */
1034 _dl_add_to_namespace_list (l, nsid);
1036 return l;
1038 #endif
1040 if (mode & RTLD_NOLOAD)
1042 /* We are not supposed to load the object unless it is already
1043 loaded. So return now. */
1044 free (realname);
1045 __close_nocancel (fd);
1046 return NULL;
1049 /* Print debugging message. */
1050 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1051 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
1053 /* This is the ELF header. We read it in `open_verify'. */
1054 header = (void *) fbp->buf;
1056 /* Signal that we are going to add new objects. */
1057 if (r->r_state == RT_CONSISTENT)
1059 #ifdef SHARED
1060 /* Auditing checkpoint: we are going to add new objects. */
1061 if ((mode & __RTLD_AUDIT) == 0
1062 && __glibc_unlikely (GLRO(dl_naudit) > 0))
1064 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
1065 /* Do not call the functions for any auditing object. */
1066 if (head->l_auditing == 0)
1068 struct audit_ifaces *afct = GLRO(dl_audit);
1069 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1071 if (afct->activity != NULL)
1072 afct->activity (&link_map_audit_state (head, cnt)->cookie,
1073 LA_ACT_ADD);
1075 afct = afct->next;
1079 #endif
1081 /* Notify the debugger we have added some objects. We need to
1082 call _dl_debug_initialize in a static program in case dynamic
1083 linking has not been used before. */
1084 r->r_state = RT_ADD;
1085 _dl_debug_state ();
1086 LIBC_PROBE (map_start, 2, nsid, r);
1087 make_consistent = true;
1089 else
1090 assert (r->r_state == RT_ADD);
1092 /* Enter the new object in the list of loaded objects. */
1093 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1094 if (__glibc_unlikely (l == NULL))
1096 #ifdef SHARED
1097 fail_new:
1098 #endif
1099 errstring = N_("cannot create shared object descriptor");
1100 goto lose_errno;
1103 /* Extract the remaining details we need from the ELF header
1104 and then read in the program header table. */
1105 l->l_entry = header->e_entry;
1106 type = header->e_type;
1107 l->l_phnum = header->e_phnum;
1109 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1110 if (header->e_phoff + maplength <= (size_t) fbp->len)
1111 phdr = (void *) (fbp->buf + header->e_phoff);
1112 else
1114 phdr = alloca (maplength);
1115 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1116 header->e_phoff) != maplength)
1118 errstring = N_("cannot read file data");
1119 goto lose_errno;
1123 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1124 * executable. Other platforms default to a nonexecutable stack and don't
1125 * need PT_GNU_STACK to do so. */
1126 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1129 /* Scan the program header table, collecting its load commands. */
1130 struct loadcmd loadcmds[l->l_phnum];
1131 size_t nloadcmds = 0;
1132 bool has_holes = false;
1134 /* The struct is initialized to zero so this is not necessary:
1135 l->l_ld = 0;
1136 l->l_phdr = 0;
1137 l->l_addr = 0; */
1138 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1139 switch (ph->p_type)
1141 /* These entries tell us where to find things once the file's
1142 segments are mapped in. We record the addresses it says
1143 verbatim, and later correct for the run-time load address. */
1144 case PT_DYNAMIC:
1145 if (ph->p_filesz)
1147 /* Debuginfo only files from "objcopy --only-keep-debug"
1148 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1149 such a segment to avoid a crash later. */
1150 l->l_ld = (void *) ph->p_vaddr;
1151 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1153 break;
1155 case PT_PHDR:
1156 l->l_phdr = (void *) ph->p_vaddr;
1157 break;
1159 case PT_LOAD:
1160 /* A load command tells us to map in part of the file.
1161 We record the load commands and process them all later. */
1162 if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0))
1164 errstring = N_("ELF load command alignment not page-aligned");
1165 goto lose;
1167 if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
1168 & (ph->p_align - 1)) != 0))
1170 errstring
1171 = N_("ELF load command address/offset not properly aligned");
1172 goto lose;
1175 struct loadcmd *c = &loadcmds[nloadcmds++];
1176 c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
1177 c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
1178 c->dataend = ph->p_vaddr + ph->p_filesz;
1179 c->allocend = ph->p_vaddr + ph->p_memsz;
1180 c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
1182 /* Determine whether there is a gap between the last segment
1183 and this one. */
1184 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1185 has_holes = true;
1187 /* Optimize a common case. */
1188 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1189 c->prot = (PF_TO_PROT
1190 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1191 #else
1192 c->prot = 0;
1193 if (ph->p_flags & PF_R)
1194 c->prot |= PROT_READ;
1195 if (ph->p_flags & PF_W)
1196 c->prot |= PROT_WRITE;
1197 if (ph->p_flags & PF_X)
1198 c->prot |= PROT_EXEC;
1199 #endif
1200 break;
1202 case PT_TLS:
1203 if (ph->p_memsz == 0)
1204 /* Nothing to do for an empty segment. */
1205 break;
1207 l->l_tls_blocksize = ph->p_memsz;
1208 l->l_tls_align = ph->p_align;
1209 if (ph->p_align == 0)
1210 l->l_tls_firstbyte_offset = 0;
1211 else
1212 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1213 l->l_tls_initimage_size = ph->p_filesz;
1214 /* Since we don't know the load address yet only store the
1215 offset. We will adjust it later. */
1216 l->l_tls_initimage = (void *) ph->p_vaddr;
1218 /* l->l_tls_modid is assigned below, once there is no
1219 possibility for failure. */
1221 if (l->l_type != lt_library
1222 && GL(dl_tls_dtv_slotinfo_list) == NULL)
1224 #ifdef SHARED
1225 /* We are loading the executable itself when the dynamic
1226 linker was executed directly. The setup will happen
1227 later. */
1228 assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
1229 #else
1230 assert (false && "TLS not initialized in static application");
1231 #endif
1233 break;
1235 case PT_GNU_STACK:
1236 stack_flags = ph->p_flags;
1237 break;
1239 case PT_GNU_RELRO:
1240 l->l_relro_addr = ph->p_vaddr;
1241 l->l_relro_size = ph->p_memsz;
1242 break;
1245 if (__glibc_unlikely (nloadcmds == 0))
1247 /* This only happens for a bogus object that will be caught with
1248 another error below. But we don't want to go through the
1249 calculations below using NLOADCMDS - 1. */
1250 errstring = N_("object file has no loadable segments");
1251 goto lose;
1254 /* dlopen of an executable is not valid because it is not possible
1255 to perform proper relocations, handle static TLS, or run the
1256 ELF constructors. For PIE, the check needs the dynamic
1257 section, so there is another check below. */
1258 if (__glibc_unlikely (type != ET_DYN)
1259 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
1261 /* This object is loaded at a fixed address. This must never
1262 happen for objects loaded with dlopen. */
1263 errstring = N_("cannot dynamically load executable");
1264 goto lose;
1267 /* Length of the sections to be loaded. */
1268 maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
1270 /* Now process the load commands and map segments into memory.
1271 This is responsible for filling in:
1272 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1274 errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
1275 maplength, has_holes, loader);
1276 if (__glibc_unlikely (errstring != NULL))
1278 /* Mappings can be in an inconsistent state: avoid unmap. */
1279 l->l_map_start = l->l_map_end = 0;
1280 goto lose;
1284 if (l->l_ld == 0)
1286 if (__glibc_unlikely (type == ET_DYN))
1288 errstring = N_("object file has no dynamic section");
1289 goto lose;
1292 else
1293 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1295 elf_get_dynamic_info (l, NULL);
1297 /* Make sure we are not dlopen'ing an object that has the
1298 DF_1_NOOPEN flag set, or a PIE object. */
1299 if ((__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
1300 && (mode & __RTLD_DLOPEN))
1301 || (__glibc_unlikely (l->l_flags_1 & DF_1_PIE)
1302 && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0)))
1304 if (l->l_flags_1 & DF_1_PIE)
1305 errstring
1306 = N_("cannot dynamically load position-independent executable");
1307 else
1308 errstring = N_("shared object cannot be dlopen()ed");
1309 goto lose;
1312 if (l->l_phdr == NULL)
1314 /* The program header is not contained in any of the segments.
1315 We have to allocate memory ourself and copy it over from out
1316 temporary place. */
1317 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1318 * sizeof (ElfW(Phdr)));
1319 if (newp == NULL)
1321 errstring = N_("cannot allocate memory for program header");
1322 goto lose_errno;
1325 l->l_phdr = memcpy (newp, phdr,
1326 (header->e_phnum * sizeof (ElfW(Phdr))));
1327 l->l_phdr_allocated = 1;
1329 else
1330 /* Adjust the PT_PHDR value by the runtime load address. */
1331 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1333 if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
1335 /* The stack is presently not executable, but this module
1336 requires that it be executable. We must change the
1337 protection of the variable which contains the flags used in
1338 the mprotect calls. */
1339 #ifdef SHARED
1340 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1342 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1343 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1345 struct link_map *const m = &GL(dl_rtld_map);
1346 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1347 + m->l_relro_size)
1348 & -GLRO(dl_pagesize));
1349 if (__glibc_likely (p + s <= relro_end))
1351 /* The variable lies in the region protected by RELRO. */
1352 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1354 errstring = N_("cannot change memory protections");
1355 goto lose_errno;
1357 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1358 __mprotect ((void *) p, s, PROT_READ);
1360 else
1361 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1363 else
1364 #endif
1365 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1367 #ifdef check_consistency
1368 check_consistency ();
1369 #endif
1371 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1372 if (errval)
1374 errstring = N_("\
1375 cannot enable executable stack as shared object requires");
1376 goto lose;
1380 /* Adjust the address of the TLS initialization image. */
1381 if (l->l_tls_initimage != NULL)
1382 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1384 /* Process program headers again after load segments are mapped in
1385 case processing requires accessing those segments. Scan program
1386 headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY
1387 exits. */
1388 for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph)
1389 switch (ph[-1].p_type)
1391 case PT_NOTE:
1392 _dl_process_pt_note (l, fd, &ph[-1]);
1393 break;
1394 case PT_GNU_PROPERTY:
1395 _dl_process_pt_gnu_property (l, fd, &ph[-1]);
1396 break;
1399 /* We are done mapping in the file. We no longer need the descriptor. */
1400 if (__glibc_unlikely (__close_nocancel (fd) != 0))
1402 errstring = N_("cannot close file descriptor");
1403 goto lose_errno;
1405 /* Signal that we closed the file. */
1406 fd = -1;
1408 /* Failures before this point are handled locally via lose.
1409 There are no more failures in this function until return,
1410 to change that the cleanup handling needs to be updated. */
1412 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1413 assert (type != ET_EXEC || l->l_type == lt_executable);
1415 l->l_entry += l->l_addr;
1417 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
1418 _dl_debug_printf ("\
1419 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1420 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1421 (int) sizeof (void *) * 2,
1422 (unsigned long int) l->l_ld,
1423 (int) sizeof (void *) * 2,
1424 (unsigned long int) l->l_addr,
1425 (int) sizeof (void *) * 2, maplength,
1426 (int) sizeof (void *) * 2,
1427 (unsigned long int) l->l_entry,
1428 (int) sizeof (void *) * 2,
1429 (unsigned long int) l->l_phdr,
1430 (int) sizeof (void *) * 2, l->l_phnum);
1432 /* Set up the symbol hash table. */
1433 _dl_setup_hash (l);
1435 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1436 have to do this for the main map. */
1437 if ((mode & RTLD_DEEPBIND) == 0
1438 && __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
1439 && &l->l_searchlist != l->l_scope[0])
1441 /* Create an appropriate searchlist. It contains only this map.
1442 This is the definition of DT_SYMBOLIC in SysVr4. */
1443 l->l_symbolic_searchlist.r_list[0] = l;
1444 l->l_symbolic_searchlist.r_nlist = 1;
1446 /* Now move the existing entries one back. */
1447 memmove (&l->l_scope[1], &l->l_scope[0],
1448 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1450 /* Now add the new entry. */
1451 l->l_scope[0] = &l->l_symbolic_searchlist;
1454 /* Remember whether this object must be initialized first. */
1455 if (l->l_flags_1 & DF_1_INITFIRST)
1456 GL(dl_initfirst) = l;
1458 /* Finally the file information. */
1459 l->l_file_id = id;
1461 #ifdef SHARED
1462 /* When auditing is used the recorded names might not include the
1463 name by which the DSO is actually known. Add that as well. */
1464 if (__glibc_unlikely (origname != NULL))
1465 add_name_to_object (l, origname);
1466 #else
1467 /* Audit modules only exist when linking is dynamic so ORIGNAME
1468 cannot be non-NULL. */
1469 assert (origname == NULL);
1470 #endif
1472 /* When we profile the SONAME might be needed for something else but
1473 loading. Add it right away. */
1474 if (__glibc_unlikely (GLRO(dl_profile) != NULL)
1475 && l->l_info[DT_SONAME] != NULL)
1476 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1477 + l->l_info[DT_SONAME]->d_un.d_val));
1479 /* If we have newly loaded libc.so, update the namespace
1480 description. */
1481 if (GL(dl_ns)[nsid].libc_map == NULL
1482 && l->l_info[DT_SONAME] != NULL
1483 && strcmp (((const char *) D_PTR (l, l_info[DT_STRTAB])
1484 + l->l_info[DT_SONAME]->d_un.d_val), LIBC_SO) == 0)
1485 GL(dl_ns)[nsid].libc_map = l;
1487 /* _dl_close can only eventually undo the module ID assignment (via
1488 remove_slotinfo) if this function returns a pointer to a link
1489 map. Therefore, delay this step until all possibilities for
1490 failure have been excluded. */
1491 if (l->l_tls_blocksize > 0
1492 && (__glibc_likely (l->l_type == lt_library)
1493 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1494 not set up TLS data structures, so don't use them now. */
1495 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL)))
1496 /* Assign the next available module ID. */
1497 l->l_tls_modid = _dl_next_tls_modid ();
1499 #ifdef DL_AFTER_LOAD
1500 DL_AFTER_LOAD (l);
1501 #endif
1503 /* Now that the object is fully initialized add it to the object list. */
1504 _dl_add_to_namespace_list (l, nsid);
1506 #ifdef SHARED
1507 /* Auditing checkpoint: we have a new object. */
1508 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
1509 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1511 struct audit_ifaces *afct = GLRO(dl_audit);
1512 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1514 if (afct->objopen != NULL)
1516 struct auditstate *state = link_map_audit_state (l, cnt);
1517 state->bindflags = afct->objopen (l, nsid, &state->cookie);
1518 l->l_audit_any_plt |= state->bindflags != 0;
1521 afct = afct->next;
1524 #endif
1526 return l;
1529 /* Print search path. */
1530 static void
1531 print_search_path (struct r_search_path_elem **list,
1532 const char *what, const char *name)
1534 char buf[max_dirnamelen + max_capstrlen];
1535 int first = 1;
1537 _dl_debug_printf (" search path=");
1539 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1541 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1542 size_t cnt;
1544 for (cnt = 0; cnt < ncapstr; ++cnt)
1545 if ((*list)->status[cnt] != nonexisting)
1547 #ifdef SHARED
1548 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1549 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1550 cp[0] = '\0';
1551 else
1552 cp[-1] = '\0';
1553 #else
1554 *endp = '\0';
1555 #endif
1557 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1558 first = 0;
1561 ++list;
1564 if (name != NULL)
1565 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1566 DSO_FILENAME (name));
1567 else
1568 _dl_debug_printf_c ("\t\t(%s)\n", what);
1571 /* Open a file and verify it is an ELF file for this architecture. We
1572 ignore only ELF files for other architectures. Non-ELF files and
1573 ELF files with different header information cause fatal errors since
1574 this could mean there is something wrong in the installation and the
1575 user might want to know about this.
1577 If FD is not -1, then the file is already open and FD refers to it.
1578 In that case, FD is consumed for both successful and error returns. */
1579 static int
1580 open_verify (const char *name, int fd,
1581 struct filebuf *fbp, struct link_map *loader,
1582 int whatcode, int mode, bool *found_other_class, bool free_name)
1584 /* This is the expected ELF header. */
1585 #define ELF32_CLASS ELFCLASS32
1586 #define ELF64_CLASS ELFCLASS64
1587 #ifndef VALID_ELF_HEADER
1588 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1589 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1590 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1591 #elif defined MORE_ELF_HEADER_DATA
1592 MORE_ELF_HEADER_DATA;
1593 #endif
1594 static const unsigned char expected[EI_NIDENT] =
1596 [EI_MAG0] = ELFMAG0,
1597 [EI_MAG1] = ELFMAG1,
1598 [EI_MAG2] = ELFMAG2,
1599 [EI_MAG3] = ELFMAG3,
1600 [EI_CLASS] = ELFW(CLASS),
1601 [EI_DATA] = byteorder,
1602 [EI_VERSION] = EV_CURRENT,
1603 [EI_OSABI] = ELFOSABI_SYSV,
1604 [EI_ABIVERSION] = 0
1606 static const struct
1608 ElfW(Word) vendorlen;
1609 ElfW(Word) datalen;
1610 ElfW(Word) type;
1611 char vendor[4];
1612 } expected_note = { 4, 16, 1, "GNU" };
1613 /* Initialize it to make the compiler happy. */
1614 const char *errstring = NULL;
1615 int errval = 0;
1617 #ifdef SHARED
1618 /* Give the auditing libraries a chance. */
1619 if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
1620 && loader->l_auditing == 0)
1622 const char *original_name = name;
1623 struct audit_ifaces *afct = GLRO(dl_audit);
1624 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1626 if (afct->objsearch != NULL)
1628 struct auditstate *state = link_map_audit_state (loader, cnt);
1629 name = afct->objsearch (name, &state->cookie, whatcode);
1630 if (name == NULL)
1631 /* Ignore the path. */
1632 return -1;
1635 afct = afct->next;
1638 if (fd != -1 && name != original_name && strcmp (name, original_name))
1640 /* An audit library changed what we're supposed to open,
1641 so FD no longer matches it. */
1642 __close_nocancel (fd);
1643 fd = -1;
1646 #endif
1648 if (fd == -1)
1649 /* Open the file. We always open files read-only. */
1650 fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
1652 if (fd != -1)
1654 ElfW(Ehdr) *ehdr;
1655 ElfW(Phdr) *phdr, *ph;
1656 ElfW(Word) *abi_note;
1657 ElfW(Word) *abi_note_malloced = NULL;
1658 unsigned int osversion;
1659 size_t maplength;
1661 /* We successfully opened the file. Now verify it is a file
1662 we can use. */
1663 __set_errno (0);
1664 fbp->len = 0;
1665 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1666 /* Read in the header. */
1669 ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
1670 sizeof (fbp->buf) - fbp->len);
1671 if (retlen <= 0)
1672 break;
1673 fbp->len += retlen;
1675 while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
1677 /* This is where the ELF header is loaded. */
1678 ehdr = (ElfW(Ehdr) *) fbp->buf;
1680 /* Now run the tests. */
1681 if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
1683 errval = errno;
1684 errstring = (errval == 0
1685 ? N_("file too short") : N_("cannot read file data"));
1686 lose:
1687 if (free_name)
1689 char *realname = (char *) name;
1690 name = strdupa (realname);
1691 free (realname);
1693 __close_nocancel (fd);
1694 _dl_signal_error (errval, name, NULL, errstring);
1697 /* See whether the ELF header is what we expect. */
1698 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1699 EI_ABIVERSION)
1700 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1701 ehdr->e_ident[EI_ABIVERSION])
1702 || memcmp (&ehdr->e_ident[EI_PAD],
1703 &expected[EI_PAD],
1704 EI_NIDENT - EI_PAD) != 0))
1706 /* Something is wrong. */
1707 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1708 if (*magp !=
1709 #if BYTE_ORDER == LITTLE_ENDIAN
1710 ((ELFMAG0 << (EI_MAG0 * 8))
1711 | (ELFMAG1 << (EI_MAG1 * 8))
1712 | (ELFMAG2 << (EI_MAG2 * 8))
1713 | (ELFMAG3 << (EI_MAG3 * 8)))
1714 #else
1715 ((ELFMAG0 << (EI_MAG3 * 8))
1716 | (ELFMAG1 << (EI_MAG2 * 8))
1717 | (ELFMAG2 << (EI_MAG1 * 8))
1718 | (ELFMAG3 << (EI_MAG0 * 8)))
1719 #endif
1721 errstring = N_("invalid ELF header");
1722 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1724 /* This is not a fatal error. On architectures where
1725 32-bit and 64-bit binaries can be run this might
1726 happen. */
1727 *found_other_class = true;
1728 goto close_and_out;
1730 else if (ehdr->e_ident[EI_DATA] != byteorder)
1732 if (BYTE_ORDER == BIG_ENDIAN)
1733 errstring = N_("ELF file data encoding not big-endian");
1734 else
1735 errstring = N_("ELF file data encoding not little-endian");
1737 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1738 errstring
1739 = N_("ELF file version ident does not match current one");
1740 /* XXX We should be able so set system specific versions which are
1741 allowed here. */
1742 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1743 errstring = N_("ELF file OS ABI invalid");
1744 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1745 ehdr->e_ident[EI_ABIVERSION]))
1746 errstring = N_("ELF file ABI version invalid");
1747 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1748 EI_NIDENT - EI_PAD) != 0)
1749 errstring = N_("nonzero padding in e_ident");
1750 else
1751 /* Otherwise we don't know what went wrong. */
1752 errstring = N_("internal error");
1754 goto lose;
1757 if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
1759 errstring = N_("ELF file version does not match current one");
1760 goto lose;
1762 if (! __glibc_likely (elf_machine_matches_host (ehdr)))
1763 goto close_and_out;
1764 else if (__glibc_unlikely (ehdr->e_type != ET_DYN
1765 && ehdr->e_type != ET_EXEC))
1767 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1768 goto lose;
1770 else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
1772 errstring = N_("ELF file's phentsize not the expected size");
1773 goto lose;
1776 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1777 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1778 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1779 else
1781 phdr = alloca (maplength);
1782 if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
1783 ehdr->e_phoff) != maplength)
1785 read_error:
1786 errval = errno;
1787 errstring = N_("cannot read file data");
1788 goto lose;
1792 if (__glibc_unlikely (elf_machine_reject_phdr_p
1793 (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
1794 loader, fd)))
1795 goto close_and_out;
1797 /* Check .note.ABI-tag if present. */
1798 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1799 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32
1800 && (ph->p_align == 4 || ph->p_align == 8))
1802 ElfW(Addr) size = ph->p_filesz;
1804 if (ph->p_offset + size <= (size_t) fbp->len)
1805 abi_note = (void *) (fbp->buf + ph->p_offset);
1806 else
1808 /* Note: __libc_use_alloca is not usable here, because
1809 thread info may not have been set up yet. */
1810 if (size < __MAX_ALLOCA_CUTOFF)
1811 abi_note = alloca (size);
1812 else
1814 /* There could be multiple PT_NOTEs. */
1815 abi_note_malloced = realloc (abi_note_malloced, size);
1816 if (abi_note_malloced == NULL)
1817 goto read_error;
1819 abi_note = abi_note_malloced;
1821 if (__pread64_nocancel (fd, (void *) abi_note, size,
1822 ph->p_offset) != size)
1824 free (abi_note_malloced);
1825 goto read_error;
1829 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1831 ElfW(Addr) note_size
1832 = ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
1833 ph->p_align);
1835 if (size - 32 < note_size)
1837 size = 0;
1838 break;
1840 size -= note_size;
1841 abi_note = (void *) abi_note + note_size;
1844 if (size == 0)
1845 continue;
1847 osversion = (abi_note[5] & 0xff) * 65536
1848 + (abi_note[6] & 0xff) * 256
1849 + (abi_note[7] & 0xff);
1850 if (abi_note[4] != __ABI_TAG_OS
1851 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1853 close_and_out:
1854 __close_nocancel (fd);
1855 __set_errno (ENOENT);
1856 fd = -1;
1859 break;
1861 free (abi_note_malloced);
1864 return fd;
1867 /* Try to open NAME in one of the directories in *DIRSP.
1868 Return the fd, or -1. If successful, fill in *REALNAME
1869 with the malloc'd full directory name. If it turns out
1870 that none of the directories in *DIRSP exists, *DIRSP is
1871 replaced with (void *) -1, and the old value is free()d
1872 if MAY_FREE_DIRS is true. */
1874 static int
1875 open_path (const char *name, size_t namelen, int mode,
1876 struct r_search_path_struct *sps, char **realname,
1877 struct filebuf *fbp, struct link_map *loader, int whatcode,
1878 bool *found_other_class)
1880 struct r_search_path_elem **dirs = sps->dirs;
1881 char *buf;
1882 int fd = -1;
1883 const char *current_what = NULL;
1884 int any = 0;
1886 if (__glibc_unlikely (dirs == NULL))
1887 /* We're called before _dl_init_paths when loading the main executable
1888 given on the command line when rtld is run directly. */
1889 return -1;
1891 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1894 struct r_search_path_elem *this_dir = *dirs;
1895 size_t buflen = 0;
1896 size_t cnt;
1897 char *edp;
1898 int here_any = 0;
1899 int err;
1901 /* If we are debugging the search for libraries print the path
1902 now if it hasn't happened now. */
1903 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
1904 && current_what != this_dir->what)
1906 current_what = this_dir->what;
1907 print_search_path (dirs, current_what, this_dir->where);
1910 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1911 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1913 /* Skip this directory if we know it does not exist. */
1914 if (this_dir->status[cnt] == nonexisting)
1915 continue;
1917 #ifdef SHARED
1918 buflen =
1919 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1920 capstr[cnt].len),
1921 name, namelen)
1922 - buf);
1923 #else
1924 buflen = (char *) __mempcpy (edp, name, namelen) - buf;
1925 #endif
1927 /* Print name we try if this is wanted. */
1928 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
1929 _dl_debug_printf (" trying file=%s\n", buf);
1931 fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
1932 found_other_class, false);
1933 if (this_dir->status[cnt] == unknown)
1935 if (fd != -1)
1936 this_dir->status[cnt] = existing;
1937 /* Do not update the directory information when loading
1938 auditing code. We must try to disturb the program as
1939 little as possible. */
1940 else if (loader == NULL
1941 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1943 /* We failed to open machine dependent library. Let's
1944 test whether there is any directory at all. */
1945 struct stat64 st;
1947 buf[buflen - namelen - 1] = '\0';
1949 if (__stat64 (buf, &st) != 0
1950 || ! S_ISDIR (st.st_mode))
1951 /* The directory does not exist or it is no directory. */
1952 this_dir->status[cnt] = nonexisting;
1953 else
1954 this_dir->status[cnt] = existing;
1958 /* Remember whether we found any existing directory. */
1959 here_any |= this_dir->status[cnt] != nonexisting;
1961 if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
1962 && __libc_enable_secure)
1964 /* This is an extra security effort to make sure nobody can
1965 preload broken shared objects which are in the trusted
1966 directories and so exploit the bugs. */
1967 struct stat64 st;
1969 if (__fstat64 (fd, &st) != 0
1970 || (st.st_mode & S_ISUID) == 0)
1972 /* The shared object cannot be tested for being SUID
1973 or this bit is not set. In this case we must not
1974 use this object. */
1975 __close_nocancel (fd);
1976 fd = -1;
1977 /* We simply ignore the file, signal this by setting
1978 the error value which would have been set by `open'. */
1979 errno = ENOENT;
1984 if (fd != -1)
1986 *realname = (char *) malloc (buflen);
1987 if (*realname != NULL)
1989 memcpy (*realname, buf, buflen);
1990 return fd;
1992 else
1994 /* No memory for the name, we certainly won't be able
1995 to load and link it. */
1996 __close_nocancel (fd);
1997 return -1;
2000 if (here_any && (err = errno) != ENOENT && err != EACCES)
2001 /* The file exists and is readable, but something went wrong. */
2002 return -1;
2004 /* Remember whether we found anything. */
2005 any |= here_any;
2007 while (*++dirs != NULL);
2009 /* Remove the whole path if none of the directories exists. */
2010 if (__glibc_unlikely (! any))
2012 /* Paths which were allocated using the minimal malloc() in ld.so
2013 must not be freed using the general free() in libc. */
2014 if (sps->malloced)
2015 free (sps->dirs);
2017 /* __rtld_search_dirs and __rtld_env_path_list are
2018 attribute_relro, therefore avoid writing to them. */
2019 if (sps != &__rtld_search_dirs && sps != &__rtld_env_path_list)
2020 sps->dirs = (void *) -1;
2023 return -1;
2026 /* Map in the shared object file NAME. */
2028 struct link_map *
2029 _dl_map_object (struct link_map *loader, const char *name,
2030 int type, int trace_mode, int mode, Lmid_t nsid)
2032 int fd;
2033 const char *origname = NULL;
2034 char *realname;
2035 char *name_copy;
2036 struct link_map *l;
2037 struct filebuf fb;
2039 assert (nsid >= 0);
2040 assert (nsid < GL(dl_nns));
2042 /* Look for this name among those already loaded. */
2043 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
2045 /* If the requested name matches the soname of a loaded object,
2046 use that object. Elide this check for names that have not
2047 yet been opened. */
2048 if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
2049 continue;
2050 if (!_dl_name_match_p (name, l))
2052 const char *soname;
2054 if (__glibc_likely (l->l_soname_added)
2055 || l->l_info[DT_SONAME] == NULL)
2056 continue;
2058 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
2059 + l->l_info[DT_SONAME]->d_un.d_val);
2060 if (strcmp (name, soname) != 0)
2061 continue;
2063 /* We have a match on a new name -- cache it. */
2064 add_name_to_object (l, soname);
2065 l->l_soname_added = 1;
2068 /* We have a match. */
2069 return l;
2072 /* Display information if we are debugging. */
2073 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
2074 && loader != NULL)
2075 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
2076 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
2077 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
2078 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
2080 #ifdef SHARED
2081 /* Give the auditing libraries a chance to change the name before we
2082 try anything. */
2083 if (__glibc_unlikely (GLRO(dl_naudit) > 0)
2084 && (loader == NULL || loader->l_auditing == 0))
2086 struct audit_ifaces *afct = GLRO(dl_audit);
2087 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2089 if (afct->objsearch != NULL)
2091 const char *before = name;
2092 struct auditstate *state = link_map_audit_state (loader, cnt);
2093 name = afct->objsearch (name, &state->cookie, LA_SER_ORIG);
2094 if (name == NULL)
2096 /* Do not try anything further. */
2097 fd = -1;
2098 goto no_file;
2100 if (before != name && strcmp (before, name) != 0)
2102 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
2103 _dl_debug_printf ("audit changed filename %s -> %s\n",
2104 before, name);
2106 if (origname == NULL)
2107 origname = before;
2111 afct = afct->next;
2114 #endif
2116 /* Will be true if we found a DSO which is of the other ELF class. */
2117 bool found_other_class = false;
2119 if (strchr (name, '/') == NULL)
2121 /* Search for NAME in several places. */
2123 size_t namelen = strlen (name) + 1;
2125 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2126 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2128 fd = -1;
2130 /* When the object has the RUNPATH information we don't use any
2131 RPATHs. */
2132 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2134 /* This is the executable's map (if there is one). Make sure that
2135 we do not look at it twice. */
2136 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2137 bool did_main_map = false;
2139 /* First try the DT_RPATH of the dependent object that caused NAME
2140 to be loaded. Then that object's dependent, and on up. */
2141 for (l = loader; l; l = l->l_loader)
2142 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2144 fd = open_path (name, namelen, mode,
2145 &l->l_rpath_dirs,
2146 &realname, &fb, loader, LA_SER_RUNPATH,
2147 &found_other_class);
2148 if (fd != -1)
2149 break;
2151 did_main_map |= l == main_map;
2154 /* If dynamically linked, try the DT_RPATH of the executable
2155 itself. NB: we do this for lookups in any namespace. */
2156 if (fd == -1 && !did_main_map
2157 && main_map != NULL && main_map->l_type != lt_loaded
2158 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2159 "RPATH"))
2160 fd = open_path (name, namelen, mode,
2161 &main_map->l_rpath_dirs,
2162 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2163 &found_other_class);
2166 /* Try the LD_LIBRARY_PATH environment variable. */
2167 if (fd == -1 && __rtld_env_path_list.dirs != (void *) -1)
2168 fd = open_path (name, namelen, mode, &__rtld_env_path_list,
2169 &realname, &fb,
2170 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2171 LA_SER_LIBPATH, &found_other_class);
2173 /* Look at the RUNPATH information for this binary. */
2174 if (fd == -1 && loader != NULL
2175 && cache_rpath (loader, &loader->l_runpath_dirs,
2176 DT_RUNPATH, "RUNPATH"))
2177 fd = open_path (name, namelen, mode,
2178 &loader->l_runpath_dirs, &realname, &fb, loader,
2179 LA_SER_RUNPATH, &found_other_class);
2181 if (fd == -1)
2183 realname = _dl_sysdep_open_object (name, namelen, &fd);
2184 if (realname != NULL)
2186 fd = open_verify (realname, fd,
2187 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2188 LA_SER_CONFIG, mode, &found_other_class,
2189 false);
2190 if (fd == -1)
2191 free (realname);
2195 #ifdef USE_LDCONFIG
2196 if (fd == -1
2197 && (__glibc_likely ((mode & __RTLD_SECURE) == 0)
2198 || ! __libc_enable_secure)
2199 && __glibc_likely (GLRO(dl_inhibit_cache) == 0))
2201 /* Check the list of libraries in the file /etc/ld.so.cache,
2202 for compatibility with Linux's ldconfig program. */
2203 char *cached = _dl_load_cache_lookup (name);
2205 if (cached != NULL)
2207 // XXX Correct to unconditionally default to namespace 0?
2208 l = (loader
2209 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2210 # ifdef SHARED
2211 ?: &GL(dl_rtld_map)
2212 # endif
2215 /* If the loader has the DF_1_NODEFLIB flag set we must not
2216 use a cache entry from any of these directories. */
2217 if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
2219 const char *dirp = system_dirs;
2220 unsigned int cnt = 0;
2224 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2226 /* The prefix matches. Don't use the entry. */
2227 free (cached);
2228 cached = NULL;
2229 break;
2232 dirp += system_dirs_len[cnt] + 1;
2233 ++cnt;
2235 while (cnt < nsystem_dirs_len);
2238 if (cached != NULL)
2240 fd = open_verify (cached, -1,
2241 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2242 LA_SER_CONFIG, mode, &found_other_class,
2243 false);
2244 if (__glibc_likely (fd != -1))
2245 realname = cached;
2246 else
2247 free (cached);
2251 #endif
2253 /* Finally, try the default path. */
2254 if (fd == -1
2255 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2256 || __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
2257 && __rtld_search_dirs.dirs != (void *) -1)
2258 fd = open_path (name, namelen, mode, &__rtld_search_dirs,
2259 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2261 /* Add another newline when we are tracing the library loading. */
2262 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2263 _dl_debug_printf ("\n");
2265 else
2267 /* The path may contain dynamic string tokens. */
2268 realname = (loader
2269 ? expand_dynamic_string_token (loader, name)
2270 : __strdup (name));
2271 if (realname == NULL)
2272 fd = -1;
2273 else
2275 fd = open_verify (realname, -1, &fb,
2276 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
2277 &found_other_class, true);
2278 if (__glibc_unlikely (fd == -1))
2279 free (realname);
2283 #ifdef SHARED
2284 no_file:
2285 #endif
2286 /* In case the LOADER information has only been provided to get to
2287 the appropriate RUNPATH/RPATH information we do not need it
2288 anymore. */
2289 if (mode & __RTLD_CALLMAP)
2290 loader = NULL;
2292 if (__glibc_unlikely (fd == -1))
2294 if (trace_mode
2295 && __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
2297 /* We haven't found an appropriate library. But since we
2298 are only interested in the list of libraries this isn't
2299 so severe. Fake an entry with all the information we
2300 have. */
2301 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2303 /* Allocate a new object map. */
2304 if ((name_copy = __strdup (name)) == NULL
2305 || (l = _dl_new_object (name_copy, name, type, loader,
2306 mode, nsid)) == NULL)
2308 free (name_copy);
2309 _dl_signal_error (ENOMEM, name, NULL,
2310 N_("cannot create shared object descriptor"));
2312 /* Signal that this is a faked entry. */
2313 l->l_faked = 1;
2314 /* Since the descriptor is initialized with zero we do not
2315 have do this here.
2316 l->l_reserved = 0; */
2317 l->l_buckets = &dummy_bucket;
2318 l->l_nbuckets = 1;
2319 l->l_relocated = 1;
2321 /* Enter the object in the object list. */
2322 _dl_add_to_namespace_list (l, nsid);
2324 return l;
2326 else if (found_other_class)
2327 _dl_signal_error (0, name, NULL,
2328 ELFW(CLASS) == ELFCLASS32
2329 ? N_("wrong ELF class: ELFCLASS64")
2330 : N_("wrong ELF class: ELFCLASS32"));
2331 else
2332 _dl_signal_error (errno, name, NULL,
2333 N_("cannot open shared object file"));
2336 void *stack_end = __libc_stack_end;
2337 return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
2338 type, mode, &stack_end, nsid);
2341 struct add_path_state
2343 bool counting;
2344 unsigned int idx;
2345 Dl_serinfo *si;
2346 char *allocptr;
2349 static void
2350 add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
2351 unsigned int flags)
2353 if (sps->dirs != (void *) -1)
2355 struct r_search_path_elem **dirs = sps->dirs;
2358 const struct r_search_path_elem *const r = *dirs++;
2359 if (p->counting)
2361 p->si->dls_cnt++;
2362 p->si->dls_size += MAX (2, r->dirnamelen);
2364 else
2366 Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
2367 sp->dls_name = p->allocptr;
2368 if (r->dirnamelen < 2)
2369 *p->allocptr++ = r->dirnamelen ? '/' : '.';
2370 else
2371 p->allocptr = __mempcpy (p->allocptr,
2372 r->dirname, r->dirnamelen - 1);
2373 *p->allocptr++ = '\0';
2374 sp->dls_flags = flags;
2377 while (*dirs != NULL);
2381 void
2382 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2384 if (counting)
2386 si->dls_cnt = 0;
2387 si->dls_size = 0;
2390 struct add_path_state p =
2392 .counting = counting,
2393 .idx = 0,
2394 .si = si,
2395 .allocptr = (char *) &si->dls_serpath[si->dls_cnt]
2398 # define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2400 /* When the object has the RUNPATH information we don't use any RPATHs. */
2401 if (loader->l_info[DT_RUNPATH] == NULL)
2403 /* First try the DT_RPATH of the dependent object that caused NAME
2404 to be loaded. Then that object's dependent, and on up. */
2406 struct link_map *l = loader;
2409 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2410 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2411 l = l->l_loader;
2413 while (l != NULL);
2415 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2416 if (loader->l_ns == LM_ID_BASE)
2418 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2419 if (l != NULL && l->l_type != lt_loaded && l != loader)
2420 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2421 add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
2425 /* Try the LD_LIBRARY_PATH environment variable. */
2426 add_path (&p, &__rtld_env_path_list, XXX_ENV);
2428 /* Look at the RUNPATH information for this binary. */
2429 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2430 add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
2432 /* XXX
2433 Here is where ld.so.cache gets checked, but we don't have
2434 a way to indicate that in the results for Dl_serinfo. */
2436 /* Finally, try the default path. */
2437 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2438 add_path (&p, &__rtld_search_dirs, XXX_default);
2440 if (counting)
2441 /* Count the struct size before the string area, which we didn't
2442 know before we completed dls_cnt. */
2443 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;