New test to expose erroneous negative sign on logb(1) (bug 887).
[glibc.git] / elf / dl-load.c
blobfe83f87eb9e72b2373609a1dc54f5dab95381373
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2012 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 <http://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 "dynamic-link.h"
34 #include <abi-tag.h>
35 #include <stackinfo.h>
36 #include <caller.h>
37 #include <sysdep.h>
39 #include <dl-dst.h>
41 /* On some systems, no flag bits are given to specify file mapping. */
42 #ifndef MAP_FILE
43 # define MAP_FILE 0
44 #endif
46 /* The right way to map in the shared library files is MAP_COPY, which
47 makes a virtual copy of the data at the time of the mmap call; this
48 guarantees the mapped pages will be consistent even if the file is
49 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
50 get is MAP_PRIVATE, which copies each page when it is modified; this
51 means if the file is overwritten, we may at some point get some pages
52 from the new version after starting with pages from the old version.
54 To make up for the lack and avoid the overwriting problem,
55 what Linux does have is MAP_DENYWRITE. This prevents anyone
56 from modifying the file while we have it mapped. */
57 #ifndef MAP_COPY
58 # ifdef MAP_DENYWRITE
59 # define MAP_COPY (MAP_PRIVATE | MAP_DENYWRITE)
60 # else
61 # define MAP_COPY MAP_PRIVATE
62 # endif
63 #endif
65 /* Some systems link their relocatable objects for another base address
66 than 0. We want to know the base address for these such that we can
67 subtract this address from the segment addresses during mapping.
68 This results in a more efficient address space usage. Defaults to
69 zero for almost all systems. */
70 #ifndef MAP_BASE_ADDR
71 # define MAP_BASE_ADDR(l) 0
72 #endif
75 #include <endian.h>
76 #if BYTE_ORDER == BIG_ENDIAN
77 # define byteorder ELFDATA2MSB
78 #elif BYTE_ORDER == LITTLE_ENDIAN
79 # define byteorder ELFDATA2LSB
80 #else
81 # error "Unknown BYTE_ORDER " BYTE_ORDER
82 # define byteorder ELFDATANONE
83 #endif
85 #define STRING(x) __STRING (x)
87 /* Handle situations where we have a preferred location in memory for
88 the shared objects. */
89 #ifdef ELF_PREFERRED_ADDRESS_DATA
90 ELF_PREFERRED_ADDRESS_DATA;
91 #endif
92 #ifndef ELF_PREFERRED_ADDRESS
93 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
94 #endif
95 #ifndef ELF_FIXED_ADDRESS
96 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
97 #endif
100 int __stack_prot attribute_hidden attribute_relro
101 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
102 = PROT_GROWSDOWN;
103 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
104 = PROT_GROWSUP;
105 #else
106 = 0;
107 #endif
110 /* Type for the buffer we put the ELF header and hopefully the program
111 header. This buffer does not really have to be too large. In most
112 cases the program header follows the ELF header directly. If this
113 is not the case all bets are off and we can make the header
114 arbitrarily large and still won't get it read. This means the only
115 question is how large are the ELF and program header combined. The
116 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
117 bytes long. Each program header entry is again 32 and 56 bytes
118 long respectively. I.e., even with a file which has 10 program
119 header entries we only have to read 372B/624B respectively. Add to
120 this a bit of margin for program notes and reading 512B and 832B
121 for 32-bit and 64-bit files respecitvely is enough. If this
122 heuristic should really fail for some file the code in
123 `_dl_map_object_from_fd' knows how to recover. */
124 struct filebuf
126 ssize_t len;
127 #if __WORDSIZE == 32
128 # define FILEBUF_SIZE 512
129 #else
130 # define FILEBUF_SIZE 832
131 #endif
132 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
135 /* This is the decomposed LD_LIBRARY_PATH search path. */
136 static struct r_search_path_struct env_path_list attribute_relro;
138 /* List of the hardware capabilities we might end up using. */
139 static const struct r_strlenpair *capstr attribute_relro;
140 static size_t ncapstr attribute_relro;
141 static size_t max_capstrlen attribute_relro;
144 /* Get the generated information about the trusted directories. */
145 #include "trusted-dirs.h"
147 static const char system_dirs[] = SYSTEM_DIRS;
148 static const size_t system_dirs_len[] =
150 SYSTEM_DIRS_LEN
152 #define nsystem_dirs_len \
153 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
156 /* Local version of `strdup' function. */
157 static char *
158 local_strdup (const char *s)
160 size_t len = strlen (s) + 1;
161 void *new = malloc (len);
163 if (new == NULL)
164 return NULL;
166 return (char *) memcpy (new, s, len);
170 static bool
171 is_trusted_path (const char *path, size_t len)
173 const char *trun = system_dirs;
175 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
177 if (len == system_dirs_len[idx] && memcmp (trun, path, len) == 0)
178 /* Found it. */
179 return true;
181 trun += system_dirs_len[idx] + 1;
184 return false;
188 static bool
189 is_trusted_path_normalize (const char *path, size_t len)
191 if (len == 0)
192 return false;
194 if (*path == ':')
196 ++path;
197 --len;
200 char *npath = (char *) alloca (len + 2);
201 char *wnp = npath;
202 while (*path != '\0')
204 if (path[0] == '/')
206 if (path[1] == '.')
208 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
210 while (wnp > npath && *--wnp != '/')
212 path += 3;
213 continue;
215 else if (path[2] == '/' || path[2] == '\0')
217 path += 2;
218 continue;
222 if (wnp > npath && wnp[-1] == '/')
224 ++path;
225 continue;
229 *wnp++ = *path++;
232 if (wnp == npath || wnp[-1] != '/')
233 *wnp++ = '/';
235 const char *trun = system_dirs;
237 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
239 if (wnp - npath >= system_dirs_len[idx]
240 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
241 /* Found it. */
242 return true;
244 trun += system_dirs_len[idx] + 1;
247 return false;
251 static size_t
252 is_dst (const char *start, const char *name, const char *str,
253 int is_path, int secure)
255 size_t len;
256 bool is_curly = false;
258 if (name[0] == '{')
260 is_curly = true;
261 ++name;
264 len = 0;
265 while (name[len] == str[len] && name[len] != '\0')
266 ++len;
268 if (is_curly)
270 if (name[len] != '}')
271 return 0;
273 /* Point again at the beginning of the name. */
274 --name;
275 /* Skip over closing curly brace and adjust for the --name. */
276 len += 2;
278 else if (name[len] != '\0' && name[len] != '/'
279 && (!is_path || name[len] != ':'))
280 return 0;
282 if (__builtin_expect (secure, 0)
283 && ((name[len] != '\0' && name[len] != '/'
284 && (!is_path || name[len] != ':'))
285 || (name != start + 1 && (!is_path || name[-2] != ':'))))
286 return 0;
288 return len;
292 size_t
293 _dl_dst_count (const char *name, int is_path)
295 const char *const start = name;
296 size_t cnt = 0;
300 size_t len;
302 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
303 is $ORIGIN alone) and it must always appear first in path. */
304 ++name;
305 if ((len = is_dst (start, name, "ORIGIN", is_path,
306 INTUSE(__libc_enable_secure))) != 0
307 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
308 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
309 ++cnt;
311 name = strchr (name + len, '$');
313 while (name != NULL);
315 return cnt;
319 char *
320 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
321 int is_path)
323 const char *const start = name;
325 /* Now fill the result path. While copying over the string we keep
326 track of the start of the last path element. When we come accross
327 a DST we copy over the value or (if the value is not available)
328 leave the entire path element out. */
329 char *wp = result;
330 char *last_elem = result;
331 bool check_for_trusted = false;
335 if (__builtin_expect (*name == '$', 0))
337 const char *repl = NULL;
338 size_t len;
340 ++name;
341 if ((len = is_dst (start, name, "ORIGIN", is_path,
342 INTUSE(__libc_enable_secure))) != 0)
344 #ifndef SHARED
345 if (l == NULL)
346 repl = _dl_get_origin ();
347 else
348 #endif
349 repl = l->l_origin;
351 check_for_trusted = (INTUSE(__libc_enable_secure)
352 && l->l_type == lt_executable);
354 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
355 repl = GLRO(dl_platform);
356 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
357 repl = DL_DST_LIB;
359 if (repl != NULL && repl != (const char *) -1)
361 wp = __stpcpy (wp, repl);
362 name += len;
364 else if (len > 1)
366 /* We cannot use this path element, the value of the
367 replacement is unknown. */
368 wp = last_elem;
369 name += len;
370 while (*name != '\0' && (!is_path || *name != ':'))
371 ++name;
372 /* Also skip following colon if this is the first rpath
373 element, but keep an empty element at the end. */
374 if (wp == result && is_path && *name == ':' && name[1] != '\0')
375 ++name;
377 else
378 /* No DST we recognize. */
379 *wp++ = '$';
381 else
383 *wp++ = *name++;
384 if (is_path && *name == ':')
386 /* In SUID/SGID programs, after $ORIGIN expansion the
387 normalized path must be rooted in one of the trusted
388 directories. */
389 if (__builtin_expect (check_for_trusted, false)
390 && !is_trusted_path_normalize (last_elem, wp - last_elem))
391 wp = last_elem;
392 else
393 last_elem = wp;
395 check_for_trusted = false;
399 while (*name != '\0');
401 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
402 path must be rooted in one of the trusted directories. */
403 if (__builtin_expect (check_for_trusted, false)
404 && !is_trusted_path_normalize (last_elem, wp - last_elem))
405 wp = last_elem;
407 *wp = '\0';
409 return result;
413 /* Return copy of argument with all recognized dynamic string tokens
414 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
415 might not be possible to determine the path from which the object
416 belonging to the map is loaded. In this case the path element
417 containing $ORIGIN is left out. */
418 static char *
419 expand_dynamic_string_token (struct link_map *l, const char *s, int is_path)
421 /* We make two runs over the string. First we determine how large the
422 resulting string is and then we copy it over. Since this is no
423 frequently executed operation we are looking here not for performance
424 but rather for code size. */
425 size_t cnt;
426 size_t total;
427 char *result;
429 /* Determine the number of DST elements. */
430 cnt = DL_DST_COUNT (s, is_path);
432 /* If we do not have to replace anything simply copy the string. */
433 if (__builtin_expect (cnt, 0) == 0)
434 return local_strdup (s);
436 /* Determine the length of the substituted string. */
437 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
439 /* Allocate the necessary memory. */
440 result = (char *) malloc (total + 1);
441 if (result == NULL)
442 return NULL;
444 return _dl_dst_substitute (l, s, result, is_path);
448 /* Add `name' to the list of names for a particular shared object.
449 `name' is expected to have been allocated with malloc and will
450 be freed if the shared object already has this name.
451 Returns false if the object already had this name. */
452 static void
453 internal_function
454 add_name_to_object (struct link_map *l, const char *name)
456 struct libname_list *lnp, *lastp;
457 struct libname_list *newname;
458 size_t name_len;
460 lastp = NULL;
461 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
462 if (strcmp (name, lnp->name) == 0)
463 return;
465 name_len = strlen (name) + 1;
466 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
467 if (newname == NULL)
469 /* No more memory. */
470 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
471 return;
473 /* The object should have a libname set from _dl_new_object. */
474 assert (lastp != NULL);
476 newname->name = memcpy (newname + 1, name, name_len);
477 newname->next = NULL;
478 newname->dont_free = 0;
479 lastp->next = newname;
482 /* Standard search directories. */
483 static struct r_search_path_struct rtld_search_dirs attribute_relro;
485 static size_t max_dirnamelen;
487 static struct r_search_path_elem **
488 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
489 int check_trusted, const char *what, const char *where)
491 char *cp;
492 size_t nelems = 0;
494 while ((cp = __strsep (&rpath, sep)) != NULL)
496 struct r_search_path_elem *dirp;
497 size_t len = strlen (cp);
499 /* `strsep' can pass an empty string. This has to be
500 interpreted as `use the current directory'. */
501 if (len == 0)
503 static const char curwd[] = "./";
504 cp = (char *) curwd;
507 /* Remove trailing slashes (except for "/"). */
508 while (len > 1 && cp[len - 1] == '/')
509 --len;
511 /* Now add one if there is none so far. */
512 if (len > 0 && cp[len - 1] != '/')
513 cp[len++] = '/';
515 /* Make sure we don't use untrusted directories if we run SUID. */
516 if (__builtin_expect (check_trusted, 0) && !is_trusted_path (cp, len))
517 continue;
519 /* See if this directory is already known. */
520 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
521 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
522 break;
524 if (dirp != NULL)
526 /* It is available, see whether it's on our own list. */
527 size_t cnt;
528 for (cnt = 0; cnt < nelems; ++cnt)
529 if (result[cnt] == dirp)
530 break;
532 if (cnt == nelems)
533 result[nelems++] = dirp;
535 else
537 size_t cnt;
538 enum r_dir_status init_val;
539 size_t where_len = where ? strlen (where) + 1 : 0;
541 /* It's a new directory. Create an entry and add it. */
542 dirp = (struct r_search_path_elem *)
543 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
544 + where_len + len + 1);
545 if (dirp == NULL)
546 _dl_signal_error (ENOMEM, NULL, NULL,
547 N_("cannot create cache for search path"));
549 dirp->dirname = ((char *) dirp + sizeof (*dirp)
550 + ncapstr * sizeof (enum r_dir_status));
551 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
552 dirp->dirnamelen = len;
554 if (len > max_dirnamelen)
555 max_dirnamelen = len;
557 /* We have to make sure all the relative directories are
558 never ignored. The current directory might change and
559 all our saved information would be void. */
560 init_val = cp[0] != '/' ? existing : unknown;
561 for (cnt = 0; cnt < ncapstr; ++cnt)
562 dirp->status[cnt] = init_val;
564 dirp->what = what;
565 if (__builtin_expect (where != NULL, 1))
566 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
567 + (ncapstr * sizeof (enum r_dir_status)),
568 where, where_len);
569 else
570 dirp->where = NULL;
572 dirp->next = GL(dl_all_dirs);
573 GL(dl_all_dirs) = dirp;
575 /* Put it in the result array. */
576 result[nelems++] = dirp;
580 /* Terminate the array. */
581 result[nelems] = NULL;
583 return result;
587 static bool
588 internal_function
589 decompose_rpath (struct r_search_path_struct *sps,
590 const char *rpath, struct link_map *l, const char *what)
592 /* Make a copy we can work with. */
593 const char *where = l->l_name;
594 char *copy;
595 char *cp;
596 struct r_search_path_elem **result;
597 size_t nelems;
598 /* Initialize to please the compiler. */
599 const char *errstring = NULL;
601 /* First see whether we must forget the RUNPATH and RPATH from this
602 object. */
603 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
604 && !INTUSE(__libc_enable_secure))
606 const char *inhp = GLRO(dl_inhibit_rpath);
610 const char *wp = where;
612 while (*inhp == *wp && *wp != '\0')
614 ++inhp;
615 ++wp;
618 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
620 /* This object is on the list of objects for which the
621 RUNPATH and RPATH must not be used. */
622 sps->dirs = (void *) -1;
623 return false;
626 while (*inhp != '\0')
627 if (*inhp++ == ':')
628 break;
630 while (*inhp != '\0');
633 /* Make a writable copy. At the same time expand possible dynamic
634 string tokens. */
635 copy = expand_dynamic_string_token (l, rpath, 1);
636 if (copy == NULL)
638 errstring = N_("cannot create RUNPATH/RPATH copy");
639 goto signal_error;
642 /* Ignore empty rpaths. */
643 if (*copy == 0)
645 free (copy);
646 sps->dirs = (struct r_search_path_elem **) -1;
647 return false;
650 /* Count the number of necessary elements in the result array. */
651 nelems = 0;
652 for (cp = copy; *cp != '\0'; ++cp)
653 if (*cp == ':')
654 ++nelems;
656 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
657 number of necessary entries. */
658 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
659 * sizeof (*result));
660 if (result == NULL)
662 free (copy);
663 errstring = N_("cannot create cache for search path");
664 signal_error:
665 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
668 fillin_rpath (copy, result, ":", 0, what, where);
670 /* Free the copied RPATH string. `fillin_rpath' make own copies if
671 necessary. */
672 free (copy);
674 sps->dirs = result;
675 /* The caller will change this value if we haven't used a real malloc. */
676 sps->malloced = 1;
677 return true;
680 /* Make sure cached path information is stored in *SP
681 and return true if there are any paths to search there. */
682 static bool
683 cache_rpath (struct link_map *l,
684 struct r_search_path_struct *sp,
685 int tag,
686 const char *what)
688 if (sp->dirs == (void *) -1)
689 return false;
691 if (sp->dirs != NULL)
692 return true;
694 if (l->l_info[tag] == NULL)
696 /* There is no path. */
697 sp->dirs = (void *) -1;
698 return false;
701 /* Make sure the cache information is available. */
702 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
703 + l->l_info[tag]->d_un.d_val),
704 l, what);
708 void
709 internal_function
710 _dl_init_paths (const char *llp)
712 size_t idx;
713 const char *strp;
714 struct r_search_path_elem *pelem, **aelem;
715 size_t round_size;
716 #ifdef SHARED
717 struct link_map *l;
718 #endif
719 /* Initialize to please the compiler. */
720 const char *errstring = NULL;
722 /* Fill in the information about the application's RPATH and the
723 directories addressed by the LD_LIBRARY_PATH environment variable. */
725 /* Get the capabilities. */
726 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
727 &ncapstr, &max_capstrlen);
729 /* First set up the rest of the default search directory entries. */
730 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
731 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
732 if (rtld_search_dirs.dirs == NULL)
734 errstring = N_("cannot create search path array");
735 signal_error:
736 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
739 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
740 + ncapstr * sizeof (enum r_dir_status))
741 / sizeof (struct r_search_path_elem));
743 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
744 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
745 * round_size * sizeof (struct r_search_path_elem));
746 if (rtld_search_dirs.dirs[0] == NULL)
748 errstring = N_("cannot create cache for search path");
749 goto signal_error;
752 rtld_search_dirs.malloced = 0;
753 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
754 strp = system_dirs;
755 idx = 0;
759 size_t cnt;
761 *aelem++ = pelem;
763 pelem->what = "system search path";
764 pelem->where = NULL;
766 pelem->dirname = strp;
767 pelem->dirnamelen = system_dirs_len[idx];
768 strp += system_dirs_len[idx] + 1;
770 /* System paths must be absolute. */
771 assert (pelem->dirname[0] == '/');
772 for (cnt = 0; cnt < ncapstr; ++cnt)
773 pelem->status[cnt] = unknown;
775 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
777 pelem += round_size;
779 while (idx < nsystem_dirs_len);
781 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
782 *aelem = NULL;
784 #ifdef SHARED
785 /* This points to the map of the main object. */
786 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
787 if (l != NULL)
789 assert (l->l_type != lt_loaded);
791 if (l->l_info[DT_RUNPATH])
793 /* Allocate room for the search path and fill in information
794 from RUNPATH. */
795 decompose_rpath (&l->l_runpath_dirs,
796 (const void *) (D_PTR (l, l_info[DT_STRTAB])
797 + l->l_info[DT_RUNPATH]->d_un.d_val),
798 l, "RUNPATH");
800 /* The RPATH is ignored. */
801 l->l_rpath_dirs.dirs = (void *) -1;
803 else
805 l->l_runpath_dirs.dirs = (void *) -1;
807 if (l->l_info[DT_RPATH])
809 /* Allocate room for the search path and fill in information
810 from RPATH. */
811 decompose_rpath (&l->l_rpath_dirs,
812 (const void *) (D_PTR (l, l_info[DT_STRTAB])
813 + l->l_info[DT_RPATH]->d_un.d_val),
814 l, "RPATH");
815 l->l_rpath_dirs.malloced = 0;
817 else
818 l->l_rpath_dirs.dirs = (void *) -1;
821 #endif /* SHARED */
823 if (llp != NULL && *llp != '\0')
825 size_t nllp;
826 const char *cp = llp;
827 char *llp_tmp;
829 #ifdef SHARED
830 /* Expand DSTs. */
831 size_t cnt = DL_DST_COUNT (llp, 1);
832 if (__builtin_expect (cnt == 0, 1))
833 llp_tmp = strdupa (llp);
834 else
836 /* Determine the length of the substituted string. */
837 size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
839 /* Allocate the necessary memory. */
840 llp_tmp = (char *) alloca (total + 1);
841 llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
843 #else
844 llp_tmp = strdupa (llp);
845 #endif
847 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
848 elements it has. */
849 nllp = 1;
850 while (*cp)
852 if (*cp == ':' || *cp == ';')
853 ++nllp;
854 ++cp;
857 env_path_list.dirs = (struct r_search_path_elem **)
858 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
859 if (env_path_list.dirs == NULL)
861 errstring = N_("cannot create cache for search path");
862 goto signal_error;
865 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
866 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
867 NULL);
869 if (env_path_list.dirs[0] == NULL)
871 free (env_path_list.dirs);
872 env_path_list.dirs = (void *) -1;
875 env_path_list.malloced = 0;
877 else
878 env_path_list.dirs = (void *) -1;
882 static void
883 __attribute__ ((noreturn, noinline))
884 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
885 const char *msg, struct r_debug *r)
887 /* The file might already be closed. */
888 if (fd != -1)
889 (void) __close (fd);
890 if (l != NULL && l->l_origin != (char *) -1l)
891 free ((char *) l->l_origin);
892 free (l);
893 free (realname);
895 if (r != NULL)
897 r->r_state = RT_CONSISTENT;
898 _dl_debug_state ();
901 _dl_signal_error (code, name, NULL, msg);
905 /* Map in the shared object NAME, actually located in REALNAME, and already
906 opened on FD. */
908 #ifndef EXTERNAL_MAP_FROM_FD
909 static
910 #endif
911 struct link_map *
912 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
913 char *realname, struct link_map *loader, int l_type,
914 int mode, void **stack_endp, Lmid_t nsid)
916 struct link_map *l = NULL;
917 const ElfW(Ehdr) *header;
918 const ElfW(Phdr) *phdr;
919 const ElfW(Phdr) *ph;
920 size_t maplength;
921 int type;
922 struct stat64 st;
923 /* Initialize to keep the compiler happy. */
924 const char *errstring = NULL;
925 int errval = 0;
926 struct r_debug *r = _dl_debug_initialize (0, nsid);
927 bool make_consistent = false;
929 /* Get file information. */
930 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
932 errstring = N_("cannot stat shared object");
933 call_lose_errno:
934 errval = errno;
935 call_lose:
936 lose (errval, fd, name, realname, l, errstring,
937 make_consistent ? r : NULL);
940 /* Look again to see if the real name matched another already loaded. */
941 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
942 if (l->l_removed == 0 && l->l_ino == st.st_ino && l->l_dev == st.st_dev)
944 /* The object is already loaded.
945 Just bump its reference count and return it. */
946 __close (fd);
948 /* If the name is not in the list of names for this object add
949 it. */
950 free (realname);
951 add_name_to_object (l, name);
953 return l;
956 #ifdef SHARED
957 /* When loading into a namespace other than the base one we must
958 avoid loading ld.so since there can only be one copy. Ever. */
959 if (__builtin_expect (nsid != LM_ID_BASE, 0)
960 && ((st.st_ino == GL(dl_rtld_map).l_ino
961 && st.st_dev == GL(dl_rtld_map).l_dev)
962 || _dl_name_match_p (name, &GL(dl_rtld_map))))
964 /* This is indeed ld.so. Create a new link_map which refers to
965 the real one for almost everything. */
966 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
967 if (l == NULL)
968 goto fail_new;
970 /* Refer to the real descriptor. */
971 l->l_real = &GL(dl_rtld_map);
973 /* No need to bump the refcount of the real object, ld.so will
974 never be unloaded. */
975 __close (fd);
977 /* Add the map for the mirrored object to the object list. */
978 _dl_add_to_namespace_list (l, nsid);
980 return l;
982 #endif
984 if (mode & RTLD_NOLOAD)
986 /* We are not supposed to load the object unless it is already
987 loaded. So return now. */
988 free (realname);
989 __close (fd);
990 return NULL;
993 /* Print debugging message. */
994 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
995 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
997 /* This is the ELF header. We read it in `open_verify'. */
998 header = (void *) fbp->buf;
1000 #ifndef MAP_ANON
1001 # define MAP_ANON 0
1002 if (_dl_zerofd == -1)
1004 _dl_zerofd = _dl_sysdep_open_zero_fill ();
1005 if (_dl_zerofd == -1)
1007 free (realname);
1008 __close (fd);
1009 _dl_signal_error (errno, NULL, NULL,
1010 N_("cannot open zero fill device"));
1013 #endif
1015 /* Signal that we are going to add new objects. */
1016 if (r->r_state == RT_CONSISTENT)
1018 #ifdef SHARED
1019 /* Auditing checkpoint: we are going to add new objects. */
1020 if ((mode & __RTLD_AUDIT) == 0
1021 && __builtin_expect (GLRO(dl_naudit) > 0, 0))
1023 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
1024 /* Do not call the functions for any auditing object. */
1025 if (head->l_auditing == 0)
1027 struct audit_ifaces *afct = GLRO(dl_audit);
1028 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1030 if (afct->activity != NULL)
1031 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
1033 afct = afct->next;
1037 #endif
1039 /* Notify the debugger we have added some objects. We need to
1040 call _dl_debug_initialize in a static program in case dynamic
1041 linking has not been used before. */
1042 r->r_state = RT_ADD;
1043 _dl_debug_state ();
1044 make_consistent = true;
1046 else
1047 assert (r->r_state == RT_ADD);
1049 /* Enter the new object in the list of loaded objects. */
1050 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1051 if (__builtin_expect (l == NULL, 0))
1053 #ifdef SHARED
1054 fail_new:
1055 #endif
1056 errstring = N_("cannot create shared object descriptor");
1057 goto call_lose_errno;
1060 /* Extract the remaining details we need from the ELF header
1061 and then read in the program header table. */
1062 l->l_entry = header->e_entry;
1063 type = header->e_type;
1064 l->l_phnum = header->e_phnum;
1066 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1067 if (header->e_phoff + maplength <= (size_t) fbp->len)
1068 phdr = (void *) (fbp->buf + header->e_phoff);
1069 else
1071 phdr = alloca (maplength);
1072 __lseek (fd, header->e_phoff, SEEK_SET);
1073 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1075 errstring = N_("cannot read file data");
1076 goto call_lose_errno;
1080 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1081 * executable. Other platforms default to a nonexecutable stack and don't
1082 * need PT_GNU_STACK to do so. */
1083 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1086 /* Scan the program header table, collecting its load commands. */
1087 struct loadcmd
1089 ElfW(Addr) mapstart, mapend, dataend, allocend;
1090 off_t mapoff;
1091 int prot;
1092 } loadcmds[l->l_phnum], *c;
1093 size_t nloadcmds = 0;
1094 bool has_holes = false;
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 l->l_ld = (void *) ph->p_vaddr;
1108 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1109 break;
1111 case PT_PHDR:
1112 l->l_phdr = (void *) ph->p_vaddr;
1113 break;
1115 case PT_LOAD:
1116 /* A load command tells us to map in part of the file.
1117 We record the load commands and process them all later. */
1118 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
1121 errstring = N_("ELF load command alignment not page-aligned");
1122 goto call_lose;
1124 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
1125 & (ph->p_align - 1)) != 0, 0))
1127 errstring
1128 = N_("ELF load command address/offset not properly aligned");
1129 goto call_lose;
1132 c = &loadcmds[nloadcmds++];
1133 c->mapstart = ph->p_vaddr & ~(GLRO(dl_pagesize) - 1);
1134 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
1135 & ~(GLRO(dl_pagesize) - 1));
1136 c->dataend = ph->p_vaddr + ph->p_filesz;
1137 c->allocend = ph->p_vaddr + ph->p_memsz;
1138 c->mapoff = ph->p_offset & ~(GLRO(dl_pagesize) - 1);
1140 /* Determine whether there is a gap between the last segment
1141 and this one. */
1142 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1143 has_holes = true;
1145 /* Optimize a common case. */
1146 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1147 c->prot = (PF_TO_PROT
1148 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1149 #else
1150 c->prot = 0;
1151 if (ph->p_flags & PF_R)
1152 c->prot |= PROT_READ;
1153 if (ph->p_flags & PF_W)
1154 c->prot |= PROT_WRITE;
1155 if (ph->p_flags & PF_X)
1156 c->prot |= PROT_EXEC;
1157 #endif
1158 break;
1160 case PT_TLS:
1161 if (ph->p_memsz == 0)
1162 /* Nothing to do for an empty segment. */
1163 break;
1165 l->l_tls_blocksize = ph->p_memsz;
1166 l->l_tls_align = ph->p_align;
1167 if (ph->p_align == 0)
1168 l->l_tls_firstbyte_offset = 0;
1169 else
1170 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1171 l->l_tls_initimage_size = ph->p_filesz;
1172 /* Since we don't know the load address yet only store the
1173 offset. We will adjust it later. */
1174 l->l_tls_initimage = (void *) ph->p_vaddr;
1176 /* If not loading the initial set of shared libraries,
1177 check whether we should permit loading a TLS segment. */
1178 if (__builtin_expect (l->l_type == lt_library, 1)
1179 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1180 not set up TLS data structures, so don't use them now. */
1181 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1183 /* Assign the next available module ID. */
1184 l->l_tls_modid = _dl_next_tls_modid ();
1185 break;
1188 #ifdef SHARED
1189 if (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0)
1190 /* We are loading the executable itself when the dynamic linker
1191 was executed directly. The setup will happen later. */
1192 break;
1194 /* In a static binary there is no way to tell if we dynamically
1195 loaded libpthread. */
1196 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1197 #endif
1199 /* We have not yet loaded libpthread.
1200 We can do the TLS setup right now! */
1202 void *tcb;
1204 /* The first call allocates TLS bookkeeping data structures.
1205 Then we allocate the TCB for the initial thread. */
1206 if (__builtin_expect (_dl_tls_setup (), 0)
1207 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1210 errval = ENOMEM;
1211 errstring = N_("\
1212 cannot allocate TLS data structures for initial thread");
1213 goto call_lose;
1216 /* Now we install the TCB in the thread register. */
1217 errstring = TLS_INIT_TP (tcb, 0);
1218 if (__builtin_expect (errstring == NULL, 1))
1220 /* Now we are all good. */
1221 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1222 break;
1225 /* The kernel is too old or somesuch. */
1226 errval = 0;
1227 _dl_deallocate_tls (tcb, 1);
1228 goto call_lose;
1231 /* Uh-oh, the binary expects TLS support but we cannot
1232 provide it. */
1233 errval = 0;
1234 errstring = N_("cannot handle TLS data");
1235 goto call_lose;
1236 break;
1238 case PT_GNU_STACK:
1239 stack_flags = ph->p_flags;
1240 break;
1242 case PT_GNU_RELRO:
1243 l->l_relro_addr = ph->p_vaddr;
1244 l->l_relro_size = ph->p_memsz;
1245 break;
1248 if (__builtin_expect (nloadcmds == 0, 0))
1250 /* This only happens for a bogus object that will be caught with
1251 another error below. But we don't want to go through the
1252 calculations below using NLOADCMDS - 1. */
1253 errstring = N_("object file has no loadable segments");
1254 goto call_lose;
1257 /* Now process the load commands and map segments into memory. */
1258 c = loadcmds;
1260 /* Length of the sections to be loaded. */
1261 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1263 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1265 /* This is a position-independent shared object. We can let the
1266 kernel map it anywhere it likes, but we must have space for all
1267 the segments in their specified positions relative to the first.
1268 So we map the first segment without MAP_FIXED, but with its
1269 extent increased to cover all the segments. Then we remove
1270 access from excess portion, and there is known sufficient space
1271 there to remap from the later segments.
1273 As a refinement, sometimes we have an address that we would
1274 prefer to map such objects at; but this is only a preference,
1275 the OS can do whatever it likes. */
1276 ElfW(Addr) mappref;
1277 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1278 c->mapstart & GLRO(dl_use_load_bias))
1279 - MAP_BASE_ADDR (l));
1281 /* Remember which part of the address space this object uses. */
1282 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1283 c->prot,
1284 MAP_COPY|MAP_FILE,
1285 fd, c->mapoff);
1286 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1288 map_error:
1289 errstring = N_("failed to map segment from shared object");
1290 goto call_lose_errno;
1293 l->l_map_end = l->l_map_start + maplength;
1294 l->l_addr = l->l_map_start - c->mapstart;
1296 if (has_holes)
1297 /* Change protection on the excess portion to disallow all access;
1298 the portions we do not remap later will be inaccessible as if
1299 unallocated. Then jump into the normal segment-mapping loop to
1300 handle the portion of the segment past the end of the file
1301 mapping. */
1302 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1303 loadcmds[nloadcmds - 1].mapstart - c->mapend,
1304 PROT_NONE);
1306 l->l_contiguous = 1;
1308 goto postmap;
1311 /* This object is loaded at a fixed address. This must never
1312 happen for objects loaded with dlopen(). */
1313 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1315 errstring = N_("cannot dynamically load executable");
1316 goto call_lose;
1319 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1320 fixed. */
1321 ELF_FIXED_ADDRESS (loader, c->mapstart);
1324 /* Remember which part of the address space this object uses. */
1325 l->l_map_start = c->mapstart + l->l_addr;
1326 l->l_map_end = l->l_map_start + maplength;
1327 l->l_contiguous = !has_holes;
1329 while (c < &loadcmds[nloadcmds])
1331 if (c->mapend > c->mapstart
1332 /* Map the segment contents from the file. */
1333 && (__mmap ((void *) (l->l_addr + c->mapstart),
1334 c->mapend - c->mapstart, c->prot,
1335 MAP_FIXED|MAP_COPY|MAP_FILE,
1336 fd, c->mapoff)
1337 == MAP_FAILED))
1338 goto map_error;
1340 postmap:
1341 if (c->prot & PROT_EXEC)
1342 l->l_text_end = l->l_addr + c->mapend;
1344 if (l->l_phdr == 0
1345 && (ElfW(Off)) c->mapoff <= header->e_phoff
1346 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1347 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1348 /* Found the program header in this segment. */
1349 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1351 if (c->allocend > c->dataend)
1353 /* Extra zero pages should appear at the end of this segment,
1354 after the data mapped from the file. */
1355 ElfW(Addr) zero, zeroend, zeropage;
1357 zero = l->l_addr + c->dataend;
1358 zeroend = l->l_addr + c->allocend;
1359 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1360 & ~(GLRO(dl_pagesize) - 1));
1362 if (zeroend < zeropage)
1363 /* All the extra data is in the last page of the segment.
1364 We can just zero it. */
1365 zeropage = zeroend;
1367 if (zeropage > zero)
1369 /* Zero the final part of the last page of the segment. */
1370 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1372 /* Dag nab it. */
1373 if (__mprotect ((caddr_t) (zero
1374 & ~(GLRO(dl_pagesize) - 1)),
1375 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1377 errstring = N_("cannot change memory protections");
1378 goto call_lose_errno;
1381 memset ((void *) zero, '\0', zeropage - zero);
1382 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1383 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1384 GLRO(dl_pagesize), c->prot);
1387 if (zeroend > zeropage)
1389 /* Map the remaining zero pages in from the zero fill FD. */
1390 caddr_t mapat;
1391 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1392 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1393 -1, 0);
1394 if (__builtin_expect (mapat == MAP_FAILED, 0))
1396 errstring = N_("cannot map zero-fill pages");
1397 goto call_lose_errno;
1402 ++c;
1406 if (l->l_ld == 0)
1408 if (__builtin_expect (type == ET_DYN, 0))
1410 errstring = N_("object file has no dynamic section");
1411 goto call_lose;
1414 else
1415 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1417 elf_get_dynamic_info (l, NULL);
1419 /* Make sure we are not dlopen'ing an object that has the
1420 DF_1_NOOPEN flag set. */
1421 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1422 && (mode & __RTLD_DLOPEN))
1424 /* We are not supposed to load this object. Free all resources. */
1425 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1427 if (!l->l_libname->dont_free)
1428 free (l->l_libname);
1430 if (l->l_phdr_allocated)
1431 free ((void *) l->l_phdr);
1433 errstring = N_("shared object cannot be dlopen()ed");
1434 goto call_lose;
1437 if (l->l_phdr == NULL)
1439 /* The program header is not contained in any of the segments.
1440 We have to allocate memory ourself and copy it over from out
1441 temporary place. */
1442 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1443 * sizeof (ElfW(Phdr)));
1444 if (newp == NULL)
1446 errstring = N_("cannot allocate memory for program header");
1447 goto call_lose_errno;
1450 l->l_phdr = memcpy (newp, phdr,
1451 (header->e_phnum * sizeof (ElfW(Phdr))));
1452 l->l_phdr_allocated = 1;
1454 else
1455 /* Adjust the PT_PHDR value by the runtime load address. */
1456 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1458 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1460 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso),
1461 0) != 0)
1463 errstring = N_("invalid caller");
1464 goto call_lose;
1467 /* The stack is presently not executable, but this module
1468 requires that it be executable. We must change the
1469 protection of the variable which contains the flags used in
1470 the mprotect calls. */
1471 #ifdef SHARED
1472 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1474 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1475 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1477 struct link_map *const m = &GL(dl_rtld_map);
1478 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1479 + m->l_relro_size)
1480 & -GLRO(dl_pagesize));
1481 if (__builtin_expect (p + s <= relro_end, 1))
1483 /* The variable lies in the region protected by RELRO. */
1484 __mprotect ((void *) p, s, PROT_READ|PROT_WRITE);
1485 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1486 __mprotect ((void *) p, s, PROT_READ);
1488 else
1489 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1491 else
1492 #endif
1493 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1495 #ifdef check_consistency
1496 check_consistency ();
1497 #endif
1499 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1500 if (errval)
1502 errstring = N_("\
1503 cannot enable executable stack as shared object requires");
1504 goto call_lose;
1508 /* Adjust the address of the TLS initialization image. */
1509 if (l->l_tls_initimage != NULL)
1510 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1512 /* We are done mapping in the file. We no longer need the descriptor. */
1513 if (__builtin_expect (__close (fd) != 0, 0))
1515 errstring = N_("cannot close file descriptor");
1516 goto call_lose_errno;
1518 /* Signal that we closed the file. */
1519 fd = -1;
1521 if (l->l_type == lt_library && type == ET_EXEC)
1522 l->l_type = lt_executable;
1524 l->l_entry += l->l_addr;
1526 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1527 _dl_debug_printf ("\
1528 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1529 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1530 (int) sizeof (void *) * 2,
1531 (unsigned long int) l->l_ld,
1532 (int) sizeof (void *) * 2,
1533 (unsigned long int) l->l_addr,
1534 (int) sizeof (void *) * 2, maplength,
1535 (int) sizeof (void *) * 2,
1536 (unsigned long int) l->l_entry,
1537 (int) sizeof (void *) * 2,
1538 (unsigned long int) l->l_phdr,
1539 (int) sizeof (void *) * 2, l->l_phnum);
1541 /* Set up the symbol hash table. */
1542 _dl_setup_hash (l);
1544 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1545 have to do this for the main map. */
1546 if ((mode & RTLD_DEEPBIND) == 0
1547 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1548 && &l->l_searchlist != l->l_scope[0])
1550 /* Create an appropriate searchlist. It contains only this map.
1551 This is the definition of DT_SYMBOLIC in SysVr4. */
1552 l->l_symbolic_searchlist.r_list[0] = l;
1553 l->l_symbolic_searchlist.r_nlist = 1;
1555 /* Now move the existing entries one back. */
1556 memmove (&l->l_scope[1], &l->l_scope[0],
1557 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1559 /* Now add the new entry. */
1560 l->l_scope[0] = &l->l_symbolic_searchlist;
1563 /* Remember whether this object must be initialized first. */
1564 if (l->l_flags_1 & DF_1_INITFIRST)
1565 GL(dl_initfirst) = l;
1567 /* Finally the file information. */
1568 l->l_dev = st.st_dev;
1569 l->l_ino = st.st_ino;
1571 /* When we profile the SONAME might be needed for something else but
1572 loading. Add it right away. */
1573 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1574 && l->l_info[DT_SONAME] != NULL)
1575 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1576 + l->l_info[DT_SONAME]->d_un.d_val));
1578 /* Now that the object is fully initialized add it to the object list. */
1579 _dl_add_to_namespace_list (l, nsid);
1581 #ifdef SHARED
1582 /* Auditing checkpoint: we have a new object. */
1583 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
1584 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1586 struct audit_ifaces *afct = GLRO(dl_audit);
1587 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1589 if (afct->objopen != NULL)
1591 l->l_audit[cnt].bindflags
1592 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1594 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1597 afct = afct->next;
1600 #endif
1602 return l;
1605 /* Print search path. */
1606 static void
1607 print_search_path (struct r_search_path_elem **list,
1608 const char *what, const char *name)
1610 char buf[max_dirnamelen + max_capstrlen];
1611 int first = 1;
1613 _dl_debug_printf (" search path=");
1615 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1617 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1618 size_t cnt;
1620 for (cnt = 0; cnt < ncapstr; ++cnt)
1621 if ((*list)->status[cnt] != nonexisting)
1623 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1624 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1625 cp[0] = '\0';
1626 else
1627 cp[-1] = '\0';
1629 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1630 first = 0;
1633 ++list;
1636 if (name != NULL)
1637 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1638 name[0] ? name : rtld_progname);
1639 else
1640 _dl_debug_printf_c ("\t\t(%s)\n", what);
1643 /* Open a file and verify it is an ELF file for this architecture. We
1644 ignore only ELF files for other architectures. Non-ELF files and
1645 ELF files with different header information cause fatal errors since
1646 this could mean there is something wrong in the installation and the
1647 user might want to know about this. */
1648 static int
1649 open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
1650 int whatcode, bool *found_other_class, bool free_name)
1652 /* This is the expected ELF header. */
1653 #define ELF32_CLASS ELFCLASS32
1654 #define ELF64_CLASS ELFCLASS64
1655 #ifndef VALID_ELF_HEADER
1656 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1657 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1658 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1659 #elif defined MORE_ELF_HEADER_DATA
1660 MORE_ELF_HEADER_DATA;
1661 #endif
1662 static const unsigned char expected[EI_NIDENT] =
1664 [EI_MAG0] = ELFMAG0,
1665 [EI_MAG1] = ELFMAG1,
1666 [EI_MAG2] = ELFMAG2,
1667 [EI_MAG3] = ELFMAG3,
1668 [EI_CLASS] = ELFW(CLASS),
1669 [EI_DATA] = byteorder,
1670 [EI_VERSION] = EV_CURRENT,
1671 [EI_OSABI] = ELFOSABI_SYSV,
1672 [EI_ABIVERSION] = 0
1674 static const struct
1676 ElfW(Word) vendorlen;
1677 ElfW(Word) datalen;
1678 ElfW(Word) type;
1679 char vendor[4];
1680 } expected_note = { 4, 16, 1, "GNU" };
1681 /* Initialize it to make the compiler happy. */
1682 const char *errstring = NULL;
1683 int errval = 0;
1685 #ifdef SHARED
1686 /* Give the auditing libraries a chance. */
1687 if (__builtin_expect (GLRO(dl_naudit) > 0, 0) && whatcode != 0
1688 && loader->l_auditing == 0)
1690 struct audit_ifaces *afct = GLRO(dl_audit);
1691 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1693 if (afct->objsearch != NULL)
1695 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1696 whatcode);
1697 if (name == NULL)
1698 /* Ignore the path. */
1699 return -1;
1702 afct = afct->next;
1705 #endif
1707 /* Open the file. We always open files read-only. */
1708 int fd = __open (name, O_RDONLY | O_CLOEXEC);
1709 if (fd != -1)
1711 ElfW(Ehdr) *ehdr;
1712 ElfW(Phdr) *phdr, *ph;
1713 ElfW(Word) *abi_note;
1714 unsigned int osversion;
1715 size_t maplength;
1717 /* We successfully openened the file. Now verify it is a file
1718 we can use. */
1719 __set_errno (0);
1720 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1722 /* This is where the ELF header is loaded. */
1723 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1724 ehdr = (ElfW(Ehdr) *) fbp->buf;
1726 /* Now run the tests. */
1727 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1729 errval = errno;
1730 errstring = (errval == 0
1731 ? N_("file too short") : N_("cannot read file data"));
1732 call_lose:
1733 if (free_name)
1735 char *realname = (char *) name;
1736 name = strdupa (realname);
1737 free (realname);
1739 lose (errval, fd, name, NULL, NULL, errstring, NULL);
1742 /* See whether the ELF header is what we expect. */
1743 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1744 EI_ABIVERSION)
1745 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1746 ehdr->e_ident[EI_ABIVERSION])
1747 || memcmp (&ehdr->e_ident[EI_PAD],
1748 &expected[EI_PAD],
1749 EI_NIDENT - EI_PAD) != 0,
1752 /* Something is wrong. */
1753 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1754 if (*magp !=
1755 #if BYTE_ORDER == LITTLE_ENDIAN
1756 ((ELFMAG0 << (EI_MAG0 * 8)) |
1757 (ELFMAG1 << (EI_MAG1 * 8)) |
1758 (ELFMAG2 << (EI_MAG2 * 8)) |
1759 (ELFMAG3 << (EI_MAG3 * 8)))
1760 #else
1761 ((ELFMAG0 << (EI_MAG3 * 8)) |
1762 (ELFMAG1 << (EI_MAG2 * 8)) |
1763 (ELFMAG2 << (EI_MAG1 * 8)) |
1764 (ELFMAG3 << (EI_MAG0 * 8)))
1765 #endif
1767 errstring = N_("invalid ELF header");
1768 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1770 /* This is not a fatal error. On architectures where
1771 32-bit and 64-bit binaries can be run this might
1772 happen. */
1773 *found_other_class = true;
1774 goto close_and_out;
1776 else if (ehdr->e_ident[EI_DATA] != byteorder)
1778 if (BYTE_ORDER == BIG_ENDIAN)
1779 errstring = N_("ELF file data encoding not big-endian");
1780 else
1781 errstring = N_("ELF file data encoding not little-endian");
1783 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1784 errstring
1785 = N_("ELF file version ident does not match current one");
1786 /* XXX We should be able so set system specific versions which are
1787 allowed here. */
1788 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1789 errstring = N_("ELF file OS ABI invalid");
1790 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1791 ehdr->e_ident[EI_ABIVERSION]))
1792 errstring = N_("ELF file ABI version invalid");
1793 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1794 EI_NIDENT - EI_PAD) != 0)
1795 errstring = N_("nonzero padding in e_ident");
1796 else
1797 /* Otherwise we don't know what went wrong. */
1798 errstring = N_("internal error");
1800 goto call_lose;
1803 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1805 errstring = N_("ELF file version does not match current one");
1806 goto call_lose;
1808 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1809 goto close_and_out;
1810 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1811 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1813 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1814 goto call_lose;
1816 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1817 != sizeof (ElfW(Phdr)))
1819 errstring = N_("ELF file's phentsize not the expected size");
1820 goto call_lose;
1823 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1824 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1825 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1826 else
1828 phdr = alloca (maplength);
1829 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1830 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1832 read_error:
1833 errval = errno;
1834 errstring = N_("cannot read file data");
1835 goto call_lose;
1839 /* Check .note.ABI-tag if present. */
1840 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1841 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1843 ElfW(Addr) size = ph->p_filesz;
1845 if (ph->p_offset + size <= (size_t) fbp->len)
1846 abi_note = (void *) (fbp->buf + ph->p_offset);
1847 else
1849 abi_note = alloca (size);
1850 __lseek (fd, ph->p_offset, SEEK_SET);
1851 if (__libc_read (fd, (void *) abi_note, size) != size)
1852 goto read_error;
1855 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1857 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1858 ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
1859 + ROUND (abi_note[0])
1860 + ROUND (abi_note[1]);
1862 if (size - 32 < note_size)
1864 size = 0;
1865 break;
1867 size -= note_size;
1868 abi_note = (void *) abi_note + note_size;
1871 if (size == 0)
1872 continue;
1874 osversion = (abi_note[5] & 0xff) * 65536
1875 + (abi_note[6] & 0xff) * 256
1876 + (abi_note[7] & 0xff);
1877 if (abi_note[4] != __ABI_TAG_OS
1878 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1880 close_and_out:
1881 __close (fd);
1882 __set_errno (ENOENT);
1883 fd = -1;
1886 break;
1890 return fd;
1893 /* Try to open NAME in one of the directories in *DIRSP.
1894 Return the fd, or -1. If successful, fill in *REALNAME
1895 with the malloc'd full directory name. If it turns out
1896 that none of the directories in *DIRSP exists, *DIRSP is
1897 replaced with (void *) -1, and the old value is free()d
1898 if MAY_FREE_DIRS is true. */
1900 static int
1901 open_path (const char *name, size_t namelen, int secure,
1902 struct r_search_path_struct *sps, char **realname,
1903 struct filebuf *fbp, struct link_map *loader, int whatcode,
1904 bool *found_other_class)
1906 struct r_search_path_elem **dirs = sps->dirs;
1907 char *buf;
1908 int fd = -1;
1909 const char *current_what = NULL;
1910 int any = 0;
1912 if (__builtin_expect (dirs == NULL, 0))
1913 /* We're called before _dl_init_paths when loading the main executable
1914 given on the command line when rtld is run directly. */
1915 return -1;
1917 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1920 struct r_search_path_elem *this_dir = *dirs;
1921 size_t buflen = 0;
1922 size_t cnt;
1923 char *edp;
1924 int here_any = 0;
1925 int err;
1927 /* If we are debugging the search for libraries print the path
1928 now if it hasn't happened now. */
1929 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1930 && current_what != this_dir->what)
1932 current_what = this_dir->what;
1933 print_search_path (dirs, current_what, this_dir->where);
1936 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1937 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1939 /* Skip this directory if we know it does not exist. */
1940 if (this_dir->status[cnt] == nonexisting)
1941 continue;
1943 buflen =
1944 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1945 capstr[cnt].len),
1946 name, namelen)
1947 - buf);
1949 /* Print name we try if this is wanted. */
1950 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1951 _dl_debug_printf (" trying file=%s\n", buf);
1953 fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
1954 false);
1955 if (this_dir->status[cnt] == unknown)
1957 if (fd != -1)
1958 this_dir->status[cnt] = existing;
1959 /* Do not update the directory information when loading
1960 auditing code. We must try to disturb the program as
1961 little as possible. */
1962 else if (loader == NULL
1963 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1965 /* We failed to open machine dependent library. Let's
1966 test whether there is any directory at all. */
1967 struct stat64 st;
1969 buf[buflen - namelen - 1] = '\0';
1971 if (__xstat64 (_STAT_VER, buf, &st) != 0
1972 || ! S_ISDIR (st.st_mode))
1973 /* The directory does not exist or it is no directory. */
1974 this_dir->status[cnt] = nonexisting;
1975 else
1976 this_dir->status[cnt] = existing;
1980 /* Remember whether we found any existing directory. */
1981 here_any |= this_dir->status[cnt] != nonexisting;
1983 if (fd != -1 && __builtin_expect (secure, 0)
1984 && INTUSE(__libc_enable_secure))
1986 /* This is an extra security effort to make sure nobody can
1987 preload broken shared objects which are in the trusted
1988 directories and so exploit the bugs. */
1989 struct stat64 st;
1991 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1992 || (st.st_mode & S_ISUID) == 0)
1994 /* The shared object cannot be tested for being SUID
1995 or this bit is not set. In this case we must not
1996 use this object. */
1997 __close (fd);
1998 fd = -1;
1999 /* We simply ignore the file, signal this by setting
2000 the error value which would have been set by `open'. */
2001 errno = ENOENT;
2006 if (fd != -1)
2008 *realname = (char *) malloc (buflen);
2009 if (*realname != NULL)
2011 memcpy (*realname, buf, buflen);
2012 return fd;
2014 else
2016 /* No memory for the name, we certainly won't be able
2017 to load and link it. */
2018 __close (fd);
2019 return -1;
2022 if (here_any && (err = errno) != ENOENT && err != EACCES)
2023 /* The file exists and is readable, but something went wrong. */
2024 return -1;
2026 /* Remember whether we found anything. */
2027 any |= here_any;
2029 while (*++dirs != NULL);
2031 /* Remove the whole path if none of the directories exists. */
2032 if (__builtin_expect (! any, 0))
2034 /* Paths which were allocated using the minimal malloc() in ld.so
2035 must not be freed using the general free() in libc. */
2036 if (sps->malloced)
2037 free (sps->dirs);
2039 /* rtld_search_dirs is attribute_relro, therefore avoid writing
2040 into it. */
2041 if (sps != &rtld_search_dirs)
2042 sps->dirs = (void *) -1;
2045 return -1;
2048 /* Map in the shared object file NAME. */
2050 struct link_map *
2051 internal_function
2052 _dl_map_object (struct link_map *loader, const char *name,
2053 int type, int trace_mode, int mode, Lmid_t nsid)
2055 int fd;
2056 char *realname;
2057 char *name_copy;
2058 struct link_map *l;
2059 struct filebuf fb;
2061 assert (nsid >= 0);
2062 assert (nsid < GL(dl_nns));
2064 /* Look for this name among those already loaded. */
2065 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
2067 /* If the requested name matches the soname of a loaded object,
2068 use that object. Elide this check for names that have not
2069 yet been opened. */
2070 if (__builtin_expect (l->l_faked, 0) != 0
2071 || __builtin_expect (l->l_removed, 0) != 0)
2072 continue;
2073 if (!_dl_name_match_p (name, l))
2075 const char *soname;
2077 if (__builtin_expect (l->l_soname_added, 1)
2078 || l->l_info[DT_SONAME] == NULL)
2079 continue;
2081 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
2082 + l->l_info[DT_SONAME]->d_un.d_val);
2083 if (strcmp (name, soname) != 0)
2084 continue;
2086 /* We have a match on a new name -- cache it. */
2087 add_name_to_object (l, soname);
2088 l->l_soname_added = 1;
2091 /* We have a match. */
2092 return l;
2095 /* Display information if we are debugging. */
2096 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
2097 && loader != NULL)
2098 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
2099 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
2100 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
2101 name, nsid, loader->l_name[0]
2102 ? loader->l_name : rtld_progname, loader->l_ns);
2104 #ifdef SHARED
2105 /* Give the auditing libraries a chance to change the name before we
2106 try anything. */
2107 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
2108 && (loader == NULL || loader->l_auditing == 0))
2110 struct audit_ifaces *afct = GLRO(dl_audit);
2111 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2113 if (afct->objsearch != NULL)
2115 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
2116 LA_SER_ORIG);
2117 if (name == NULL)
2119 /* Do not try anything further. */
2120 fd = -1;
2121 goto no_file;
2125 afct = afct->next;
2128 #endif
2130 /* Will be true if we found a DSO which is of the other ELF class. */
2131 bool found_other_class = false;
2133 if (strchr (name, '/') == NULL)
2135 /* Search for NAME in several places. */
2137 size_t namelen = strlen (name) + 1;
2139 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2140 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2142 fd = -1;
2144 /* When the object has the RUNPATH information we don't use any
2145 RPATHs. */
2146 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2148 /* This is the executable's map (if there is one). Make sure that
2149 we do not look at it twice. */
2150 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2151 bool did_main_map = false;
2153 /* First try the DT_RPATH of the dependent object that caused NAME
2154 to be loaded. Then that object's dependent, and on up. */
2155 for (l = loader; l; l = l->l_loader)
2156 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2158 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2159 &l->l_rpath_dirs,
2160 &realname, &fb, loader, LA_SER_RUNPATH,
2161 &found_other_class);
2162 if (fd != -1)
2163 break;
2165 did_main_map |= l == main_map;
2168 /* If dynamically linked, try the DT_RPATH of the executable
2169 itself. NB: we do this for lookups in any namespace. */
2170 if (fd == -1 && !did_main_map
2171 && main_map != NULL && main_map->l_type != lt_loaded
2172 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2173 "RPATH"))
2174 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2175 &main_map->l_rpath_dirs,
2176 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2177 &found_other_class);
2180 /* Try the LD_LIBRARY_PATH environment variable. */
2181 if (fd == -1 && env_path_list.dirs != (void *) -1)
2182 fd = open_path (name, namelen, mode & __RTLD_SECURE, &env_path_list,
2183 &realname, &fb,
2184 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2185 LA_SER_LIBPATH, &found_other_class);
2187 /* Look at the RUNPATH information for this binary. */
2188 if (fd == -1 && loader != NULL
2189 && cache_rpath (loader, &loader->l_runpath_dirs,
2190 DT_RUNPATH, "RUNPATH"))
2191 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2192 &loader->l_runpath_dirs, &realname, &fb, loader,
2193 LA_SER_RUNPATH, &found_other_class);
2195 if (fd == -1
2196 && (__builtin_expect (! (mode & __RTLD_SECURE), 1)
2197 || ! INTUSE(__libc_enable_secure))
2198 && __builtin_expect (GLRO(dl_inhibit_cache) == 0, 1))
2200 /* Check the list of libraries in the file /etc/ld.so.cache,
2201 for compatibility with Linux's ldconfig program. */
2202 const char *cached = _dl_load_cache_lookup (name);
2204 if (cached != NULL)
2206 #ifdef SHARED
2207 // XXX Correct to unconditionally default to namespace 0?
2208 l = (loader
2209 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2210 ?: &GL(dl_rtld_map));
2211 #else
2212 l = loader;
2213 #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 (
2218 #ifndef SHARED
2219 /* 'l' is always != NULL for dynamically linked objects. */
2220 l != NULL &&
2221 #endif
2222 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
2224 const char *dirp = system_dirs;
2225 unsigned int cnt = 0;
2229 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2231 /* The prefix matches. Don't use the entry. */
2232 cached = NULL;
2233 break;
2236 dirp += system_dirs_len[cnt] + 1;
2237 ++cnt;
2239 while (cnt < nsystem_dirs_len);
2242 if (cached != NULL)
2244 fd = open_verify (cached,
2245 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2246 LA_SER_CONFIG, &found_other_class, false);
2247 if (__builtin_expect (fd != -1, 1))
2249 realname = local_strdup (cached);
2250 if (realname == NULL)
2252 __close (fd);
2253 fd = -1;
2260 /* Finally, try the default path. */
2261 if (fd == -1
2262 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2263 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
2264 && rtld_search_dirs.dirs != (void *) -1)
2265 fd = open_path (name, namelen, mode & __RTLD_SECURE, &rtld_search_dirs,
2266 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2268 /* Add another newline when we are tracing the library loading. */
2269 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2270 _dl_debug_printf ("\n");
2272 else
2274 /* The path may contain dynamic string tokens. */
2275 realname = (loader
2276 ? expand_dynamic_string_token (loader, name, 0)
2277 : local_strdup (name));
2278 if (realname == NULL)
2279 fd = -1;
2280 else
2282 fd = open_verify (realname, &fb,
2283 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
2284 &found_other_class, true);
2285 if (__builtin_expect (fd, 0) == -1)
2286 free (realname);
2290 #ifdef SHARED
2291 no_file:
2292 #endif
2293 /* In case the LOADER information has only been provided to get to
2294 the appropriate RUNPATH/RPATH information we do not need it
2295 anymore. */
2296 if (mode & __RTLD_CALLMAP)
2297 loader = NULL;
2299 if (__builtin_expect (fd, 0) == -1)
2301 if (trace_mode
2302 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
2304 /* We haven't found an appropriate library. But since we
2305 are only interested in the list of libraries this isn't
2306 so severe. Fake an entry with all the information we
2307 have. */
2308 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2310 /* Allocate a new object map. */
2311 if ((name_copy = local_strdup (name)) == NULL
2312 || (l = _dl_new_object (name_copy, name, type, loader,
2313 mode, nsid)) == NULL)
2315 free (name_copy);
2316 _dl_signal_error (ENOMEM, name, NULL,
2317 N_("cannot create shared object descriptor"));
2319 /* Signal that this is a faked entry. */
2320 l->l_faked = 1;
2321 /* Since the descriptor is initialized with zero we do not
2322 have do this here.
2323 l->l_reserved = 0; */
2324 l->l_buckets = &dummy_bucket;
2325 l->l_nbuckets = 1;
2326 l->l_relocated = 1;
2328 /* Enter the object in the object list. */
2329 _dl_add_to_namespace_list (l, nsid);
2331 return l;
2333 else if (found_other_class)
2334 _dl_signal_error (0, name, NULL,
2335 ELFW(CLASS) == ELFCLASS32
2336 ? N_("wrong ELF class: ELFCLASS64")
2337 : N_("wrong ELF class: ELFCLASS32"));
2338 else
2339 _dl_signal_error (errno, name, NULL,
2340 N_("cannot open shared object file"));
2343 void *stack_end = __libc_stack_end;
2344 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
2345 &stack_end, nsid);
2349 void
2350 internal_function
2351 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2353 if (counting)
2355 si->dls_cnt = 0;
2356 si->dls_size = 0;
2359 unsigned int idx = 0;
2360 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2361 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2362 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2364 if (sps->dirs != (void *) -1)
2366 struct r_search_path_elem **dirs = sps->dirs;
2369 const struct r_search_path_elem *const r = *dirs++;
2370 if (counting)
2372 si->dls_cnt++;
2373 si->dls_size += MAX (2, r->dirnamelen);
2375 else
2377 Dl_serpath *const sp = &si->dls_serpath[idx++];
2378 sp->dls_name = allocptr;
2379 if (r->dirnamelen < 2)
2380 *allocptr++ = r->dirnamelen ? '/' : '.';
2381 else
2382 allocptr = __mempcpy (allocptr,
2383 r->dirname, r->dirnamelen - 1);
2384 *allocptr++ = '\0';
2385 sp->dls_flags = flags;
2388 while (*dirs != NULL);
2392 /* When the object has the RUNPATH information we don't use any RPATHs. */
2393 if (loader->l_info[DT_RUNPATH] == NULL)
2395 /* First try the DT_RPATH of the dependent object that caused NAME
2396 to be loaded. Then that object's dependent, and on up. */
2398 struct link_map *l = loader;
2401 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2402 add_path (&l->l_rpath_dirs, XXX_RPATH);
2403 l = l->l_loader;
2405 while (l != NULL);
2407 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2408 if (loader->l_ns == LM_ID_BASE)
2410 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2411 if (l != NULL && l->l_type != lt_loaded && l != loader)
2412 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2413 add_path (&l->l_rpath_dirs, XXX_RPATH);
2417 /* Try the LD_LIBRARY_PATH environment variable. */
2418 add_path (&env_path_list, XXX_ENV);
2420 /* Look at the RUNPATH information for this binary. */
2421 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2422 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2424 /* XXX
2425 Here is where ld.so.cache gets checked, but we don't have
2426 a way to indicate that in the results for Dl_serinfo. */
2428 /* Finally, try the default path. */
2429 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2430 add_path (&rtld_search_dirs, XXX_default);
2432 if (counting)
2433 /* Count the struct size before the string area, which we didn't
2434 know before we completed dls_cnt. */
2435 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;