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[glibc.git] / elf / dl-load.c
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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>
38 #include <stap-probe.h>
40 #include <dl-dst.h>
42 /* On some systems, no flag bits are given to specify file mapping. */
43 #ifndef MAP_FILE
44 # define MAP_FILE 0
45 #endif
47 /* The right way to map in the shared library files is MAP_COPY, which
48 makes a virtual copy of the data at the time of the mmap call; this
49 guarantees the mapped pages will be consistent even if the file is
50 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
51 get is MAP_PRIVATE, which copies each page when it is modified; this
52 means if the file is overwritten, we may at some point get some pages
53 from the new version after starting with pages from the old version.
55 To make up for the lack and avoid the overwriting problem,
56 what Linux does have is MAP_DENYWRITE. This prevents anyone
57 from modifying the file while we have it mapped. */
58 #ifndef MAP_COPY
59 # ifdef MAP_DENYWRITE
60 # define MAP_COPY (MAP_PRIVATE | MAP_DENYWRITE)
61 # else
62 # define MAP_COPY MAP_PRIVATE
63 # endif
64 #endif
66 /* Some systems link their relocatable objects for another base address
67 than 0. We want to know the base address for these such that we can
68 subtract this address from the segment addresses during mapping.
69 This results in a more efficient address space usage. Defaults to
70 zero for almost all systems. */
71 #ifndef MAP_BASE_ADDR
72 # define MAP_BASE_ADDR(l) 0
73 #endif
76 #include <endian.h>
77 #if BYTE_ORDER == BIG_ENDIAN
78 # define byteorder ELFDATA2MSB
79 #elif BYTE_ORDER == LITTLE_ENDIAN
80 # define byteorder ELFDATA2LSB
81 #else
82 # error "Unknown BYTE_ORDER " BYTE_ORDER
83 # define byteorder ELFDATANONE
84 #endif
86 #define STRING(x) __STRING (x)
88 /* Handle situations where we have a preferred location in memory for
89 the shared objects. */
90 #ifdef ELF_PREFERRED_ADDRESS_DATA
91 ELF_PREFERRED_ADDRESS_DATA;
92 #endif
93 #ifndef ELF_PREFERRED_ADDRESS
94 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
95 #endif
96 #ifndef ELF_FIXED_ADDRESS
97 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
98 #endif
101 int __stack_prot attribute_hidden attribute_relro
102 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
103 = PROT_GROWSDOWN;
104 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
105 = PROT_GROWSUP;
106 #else
107 = 0;
108 #endif
111 /* Type for the buffer we put the ELF header and hopefully the program
112 header. This buffer does not really have to be too large. In most
113 cases the program header follows the ELF header directly. If this
114 is not the case all bets are off and we can make the header
115 arbitrarily large and still won't get it read. This means the only
116 question is how large are the ELF and program header combined. The
117 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
118 bytes long. Each program header entry is again 32 and 56 bytes
119 long respectively. I.e., even with a file which has 10 program
120 header entries we only have to read 372B/624B respectively. Add to
121 this a bit of margin for program notes and reading 512B and 832B
122 for 32-bit and 64-bit files respecitvely is enough. If this
123 heuristic should really fail for some file the code in
124 `_dl_map_object_from_fd' knows how to recover. */
125 struct filebuf
127 ssize_t len;
128 #if __WORDSIZE == 32
129 # define FILEBUF_SIZE 512
130 #else
131 # define FILEBUF_SIZE 832
132 #endif
133 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
136 /* This is the decomposed LD_LIBRARY_PATH search path. */
137 static struct r_search_path_struct env_path_list attribute_relro;
139 /* List of the hardware capabilities we might end up using. */
140 static const struct r_strlenpair *capstr attribute_relro;
141 static size_t ncapstr attribute_relro;
142 static size_t max_capstrlen attribute_relro;
145 /* Get the generated information about the trusted directories. */
146 #include "trusted-dirs.h"
148 static const char system_dirs[] = SYSTEM_DIRS;
149 static const size_t system_dirs_len[] =
151 SYSTEM_DIRS_LEN
153 #define nsystem_dirs_len \
154 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
157 /* Local version of `strdup' function. */
158 static char *
159 local_strdup (const char *s)
161 size_t len = strlen (s) + 1;
162 void *new = malloc (len);
164 if (new == NULL)
165 return NULL;
167 return (char *) memcpy (new, s, len);
171 static bool
172 is_trusted_path (const char *path, size_t len)
174 const char *trun = system_dirs;
176 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
178 if (len == system_dirs_len[idx] && memcmp (trun, path, len) == 0)
179 /* Found it. */
180 return true;
182 trun += system_dirs_len[idx] + 1;
185 return false;
189 static bool
190 is_trusted_path_normalize (const char *path, size_t len)
192 if (len == 0)
193 return false;
195 if (*path == ':')
197 ++path;
198 --len;
201 char *npath = (char *) alloca (len + 2);
202 char *wnp = npath;
203 while (*path != '\0')
205 if (path[0] == '/')
207 if (path[1] == '.')
209 if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
211 while (wnp > npath && *--wnp != '/')
213 path += 3;
214 continue;
216 else if (path[2] == '/' || path[2] == '\0')
218 path += 2;
219 continue;
223 if (wnp > npath && wnp[-1] == '/')
225 ++path;
226 continue;
230 *wnp++ = *path++;
233 if (wnp == npath || wnp[-1] != '/')
234 *wnp++ = '/';
236 const char *trun = system_dirs;
238 for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
240 if (wnp - npath >= system_dirs_len[idx]
241 && memcmp (trun, npath, system_dirs_len[idx]) == 0)
242 /* Found it. */
243 return true;
245 trun += system_dirs_len[idx] + 1;
248 return false;
252 static size_t
253 is_dst (const char *start, const char *name, const char *str,
254 int is_path, int secure)
256 size_t len;
257 bool is_curly = false;
259 if (name[0] == '{')
261 is_curly = true;
262 ++name;
265 len = 0;
266 while (name[len] == str[len] && name[len] != '\0')
267 ++len;
269 if (is_curly)
271 if (name[len] != '}')
272 return 0;
274 /* Point again at the beginning of the name. */
275 --name;
276 /* Skip over closing curly brace and adjust for the --name. */
277 len += 2;
279 else if (name[len] != '\0' && name[len] != '/'
280 && (!is_path || name[len] != ':'))
281 return 0;
283 if (__builtin_expect (secure, 0)
284 && ((name[len] != '\0' && name[len] != '/'
285 && (!is_path || name[len] != ':'))
286 || (name != start + 1 && (!is_path || name[-2] != ':'))))
287 return 0;
289 return len;
293 size_t
294 _dl_dst_count (const char *name, int is_path)
296 const char *const start = name;
297 size_t cnt = 0;
301 size_t len;
303 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
304 is $ORIGIN alone) and it must always appear first in path. */
305 ++name;
306 if ((len = is_dst (start, name, "ORIGIN", is_path,
307 INTUSE(__libc_enable_secure))) != 0
308 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
309 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
310 ++cnt;
312 name = strchr (name + len, '$');
314 while (name != NULL);
316 return cnt;
320 char *
321 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
322 int is_path)
324 const char *const start = name;
326 /* Now fill the result path. While copying over the string we keep
327 track of the start of the last path element. When we come accross
328 a DST we copy over the value or (if the value is not available)
329 leave the entire path element out. */
330 char *wp = result;
331 char *last_elem = result;
332 bool check_for_trusted = false;
336 if (__builtin_expect (*name == '$', 0))
338 const char *repl = NULL;
339 size_t len;
341 ++name;
342 if ((len = is_dst (start, name, "ORIGIN", is_path,
343 INTUSE(__libc_enable_secure))) != 0)
345 #ifndef SHARED
346 if (l == NULL)
347 repl = _dl_get_origin ();
348 else
349 #endif
350 repl = l->l_origin;
352 check_for_trusted = (INTUSE(__libc_enable_secure)
353 && l->l_type == lt_executable);
355 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
356 repl = GLRO(dl_platform);
357 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
358 repl = DL_DST_LIB;
360 if (repl != NULL && repl != (const char *) -1)
362 wp = __stpcpy (wp, repl);
363 name += len;
365 else if (len > 1)
367 /* We cannot use this path element, the value of the
368 replacement is unknown. */
369 wp = last_elem;
370 name += len;
371 while (*name != '\0' && (!is_path || *name != ':'))
372 ++name;
373 /* Also skip following colon if this is the first rpath
374 element, but keep an empty element at the end. */
375 if (wp == result && is_path && *name == ':' && name[1] != '\0')
376 ++name;
378 else
379 /* No DST we recognize. */
380 *wp++ = '$';
382 else
384 *wp++ = *name++;
385 if (is_path && *name == ':')
387 /* In SUID/SGID programs, after $ORIGIN expansion the
388 normalized path must be rooted in one of the trusted
389 directories. */
390 if (__builtin_expect (check_for_trusted, false)
391 && !is_trusted_path_normalize (last_elem, wp - last_elem))
392 wp = last_elem;
393 else
394 last_elem = wp;
396 check_for_trusted = false;
400 while (*name != '\0');
402 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
403 path must be rooted in one of the trusted directories. */
404 if (__builtin_expect (check_for_trusted, false)
405 && !is_trusted_path_normalize (last_elem, wp - last_elem))
406 wp = last_elem;
408 *wp = '\0';
410 return result;
414 /* Return copy of argument with all recognized dynamic string tokens
415 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
416 might not be possible to determine the path from which the object
417 belonging to the map is loaded. In this case the path element
418 containing $ORIGIN is left out. */
419 static char *
420 expand_dynamic_string_token (struct link_map *l, const char *s, int is_path)
422 /* We make two runs over the string. First we determine how large the
423 resulting string is and then we copy it over. Since this is no
424 frequently executed operation we are looking here not for performance
425 but rather for code size. */
426 size_t cnt;
427 size_t total;
428 char *result;
430 /* Determine the number of DST elements. */
431 cnt = DL_DST_COUNT (s, is_path);
433 /* If we do not have to replace anything simply copy the string. */
434 if (__builtin_expect (cnt, 0) == 0)
435 return local_strdup (s);
437 /* Determine the length of the substituted string. */
438 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
440 /* Allocate the necessary memory. */
441 result = (char *) malloc (total + 1);
442 if (result == NULL)
443 return NULL;
445 return _dl_dst_substitute (l, s, result, is_path);
449 /* Add `name' to the list of names for a particular shared object.
450 `name' is expected to have been allocated with malloc and will
451 be freed if the shared object already has this name.
452 Returns false if the object already had this name. */
453 static void
454 internal_function
455 add_name_to_object (struct link_map *l, const char *name)
457 struct libname_list *lnp, *lastp;
458 struct libname_list *newname;
459 size_t name_len;
461 lastp = NULL;
462 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
463 if (strcmp (name, lnp->name) == 0)
464 return;
466 name_len = strlen (name) + 1;
467 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
468 if (newname == NULL)
470 /* No more memory. */
471 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
472 return;
474 /* The object should have a libname set from _dl_new_object. */
475 assert (lastp != NULL);
477 newname->name = memcpy (newname + 1, name, name_len);
478 newname->next = NULL;
479 newname->dont_free = 0;
480 lastp->next = newname;
483 /* Standard search directories. */
484 static struct r_search_path_struct rtld_search_dirs attribute_relro;
486 static size_t max_dirnamelen;
488 static struct r_search_path_elem **
489 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
490 int check_trusted, const char *what, const char *where)
492 char *cp;
493 size_t nelems = 0;
495 while ((cp = __strsep (&rpath, sep)) != NULL)
497 struct r_search_path_elem *dirp;
498 size_t len = strlen (cp);
500 /* `strsep' can pass an empty string. This has to be
501 interpreted as `use the current directory'. */
502 if (len == 0)
504 static const char curwd[] = "./";
505 cp = (char *) curwd;
508 /* Remove trailing slashes (except for "/"). */
509 while (len > 1 && cp[len - 1] == '/')
510 --len;
512 /* Now add one if there is none so far. */
513 if (len > 0 && cp[len - 1] != '/')
514 cp[len++] = '/';
516 /* Make sure we don't use untrusted directories if we run SUID. */
517 if (__builtin_expect (check_trusted, 0) && !is_trusted_path (cp, len))
518 continue;
520 /* See if this directory is already known. */
521 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
522 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
523 break;
525 if (dirp != NULL)
527 /* It is available, see whether it's on our own list. */
528 size_t cnt;
529 for (cnt = 0; cnt < nelems; ++cnt)
530 if (result[cnt] == dirp)
531 break;
533 if (cnt == nelems)
534 result[nelems++] = dirp;
536 else
538 size_t cnt;
539 enum r_dir_status init_val;
540 size_t where_len = where ? strlen (where) + 1 : 0;
542 /* It's a new directory. Create an entry and add it. */
543 dirp = (struct r_search_path_elem *)
544 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
545 + where_len + len + 1);
546 if (dirp == NULL)
547 _dl_signal_error (ENOMEM, NULL, NULL,
548 N_("cannot create cache for search path"));
550 dirp->dirname = ((char *) dirp + sizeof (*dirp)
551 + ncapstr * sizeof (enum r_dir_status));
552 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
553 dirp->dirnamelen = len;
555 if (len > max_dirnamelen)
556 max_dirnamelen = len;
558 /* We have to make sure all the relative directories are
559 never ignored. The current directory might change and
560 all our saved information would be void. */
561 init_val = cp[0] != '/' ? existing : unknown;
562 for (cnt = 0; cnt < ncapstr; ++cnt)
563 dirp->status[cnt] = init_val;
565 dirp->what = what;
566 if (__builtin_expect (where != NULL, 1))
567 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
568 + (ncapstr * sizeof (enum r_dir_status)),
569 where, where_len);
570 else
571 dirp->where = NULL;
573 dirp->next = GL(dl_all_dirs);
574 GL(dl_all_dirs) = dirp;
576 /* Put it in the result array. */
577 result[nelems++] = dirp;
581 /* Terminate the array. */
582 result[nelems] = NULL;
584 return result;
588 static bool
589 internal_function
590 decompose_rpath (struct r_search_path_struct *sps,
591 const char *rpath, struct link_map *l, const char *what)
593 /* Make a copy we can work with. */
594 const char *where = l->l_name;
595 char *copy;
596 char *cp;
597 struct r_search_path_elem **result;
598 size_t nelems;
599 /* Initialize to please the compiler. */
600 const char *errstring = NULL;
602 /* First see whether we must forget the RUNPATH and RPATH from this
603 object. */
604 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
605 && !INTUSE(__libc_enable_secure))
607 const char *inhp = GLRO(dl_inhibit_rpath);
611 const char *wp = where;
613 while (*inhp == *wp && *wp != '\0')
615 ++inhp;
616 ++wp;
619 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
621 /* This object is on the list of objects for which the
622 RUNPATH and RPATH must not be used. */
623 sps->dirs = (void *) -1;
624 return false;
627 while (*inhp != '\0')
628 if (*inhp++ == ':')
629 break;
631 while (*inhp != '\0');
634 /* Make a writable copy. At the same time expand possible dynamic
635 string tokens. */
636 copy = expand_dynamic_string_token (l, rpath, 1);
637 if (copy == NULL)
639 errstring = N_("cannot create RUNPATH/RPATH copy");
640 goto signal_error;
643 /* Ignore empty rpaths. */
644 if (*copy == 0)
646 free (copy);
647 sps->dirs = (struct r_search_path_elem **) -1;
648 return false;
651 /* Count the number of necessary elements in the result array. */
652 nelems = 0;
653 for (cp = copy; *cp != '\0'; ++cp)
654 if (*cp == ':')
655 ++nelems;
657 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
658 number of necessary entries. */
659 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
660 * sizeof (*result));
661 if (result == NULL)
663 free (copy);
664 errstring = N_("cannot create cache for search path");
665 signal_error:
666 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
669 fillin_rpath (copy, result, ":", 0, what, where);
671 /* Free the copied RPATH string. `fillin_rpath' make own copies if
672 necessary. */
673 free (copy);
675 sps->dirs = result;
676 /* The caller will change this value if we haven't used a real malloc. */
677 sps->malloced = 1;
678 return true;
681 /* Make sure cached path information is stored in *SP
682 and return true if there are any paths to search there. */
683 static bool
684 cache_rpath (struct link_map *l,
685 struct r_search_path_struct *sp,
686 int tag,
687 const char *what)
689 if (sp->dirs == (void *) -1)
690 return false;
692 if (sp->dirs != NULL)
693 return true;
695 if (l->l_info[tag] == NULL)
697 /* There is no path. */
698 sp->dirs = (void *) -1;
699 return false;
702 /* Make sure the cache information is available. */
703 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
704 + l->l_info[tag]->d_un.d_val),
705 l, what);
709 void
710 internal_function
711 _dl_init_paths (const char *llp)
713 size_t idx;
714 const char *strp;
715 struct r_search_path_elem *pelem, **aelem;
716 size_t round_size;
717 #ifdef SHARED
718 struct link_map *l;
719 #endif
720 /* Initialize to please the compiler. */
721 const char *errstring = NULL;
723 /* Fill in the information about the application's RPATH and the
724 directories addressed by the LD_LIBRARY_PATH environment variable. */
726 /* Get the capabilities. */
727 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
728 &ncapstr, &max_capstrlen);
730 /* First set up the rest of the default search directory entries. */
731 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
732 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
733 if (rtld_search_dirs.dirs == NULL)
735 errstring = N_("cannot create search path array");
736 signal_error:
737 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
740 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
741 + ncapstr * sizeof (enum r_dir_status))
742 / sizeof (struct r_search_path_elem));
744 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
745 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
746 * round_size * sizeof (struct r_search_path_elem));
747 if (rtld_search_dirs.dirs[0] == NULL)
749 errstring = N_("cannot create cache for search path");
750 goto signal_error;
753 rtld_search_dirs.malloced = 0;
754 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
755 strp = system_dirs;
756 idx = 0;
760 size_t cnt;
762 *aelem++ = pelem;
764 pelem->what = "system search path";
765 pelem->where = NULL;
767 pelem->dirname = strp;
768 pelem->dirnamelen = system_dirs_len[idx];
769 strp += system_dirs_len[idx] + 1;
771 /* System paths must be absolute. */
772 assert (pelem->dirname[0] == '/');
773 for (cnt = 0; cnt < ncapstr; ++cnt)
774 pelem->status[cnt] = unknown;
776 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
778 pelem += round_size;
780 while (idx < nsystem_dirs_len);
782 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
783 *aelem = NULL;
785 #ifdef SHARED
786 /* This points to the map of the main object. */
787 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
788 if (l != NULL)
790 assert (l->l_type != lt_loaded);
792 if (l->l_info[DT_RUNPATH])
794 /* Allocate room for the search path and fill in information
795 from RUNPATH. */
796 decompose_rpath (&l->l_runpath_dirs,
797 (const void *) (D_PTR (l, l_info[DT_STRTAB])
798 + l->l_info[DT_RUNPATH]->d_un.d_val),
799 l, "RUNPATH");
801 /* The RPATH is ignored. */
802 l->l_rpath_dirs.dirs = (void *) -1;
804 else
806 l->l_runpath_dirs.dirs = (void *) -1;
808 if (l->l_info[DT_RPATH])
810 /* Allocate room for the search path and fill in information
811 from RPATH. */
812 decompose_rpath (&l->l_rpath_dirs,
813 (const void *) (D_PTR (l, l_info[DT_STRTAB])
814 + l->l_info[DT_RPATH]->d_un.d_val),
815 l, "RPATH");
816 l->l_rpath_dirs.malloced = 0;
818 else
819 l->l_rpath_dirs.dirs = (void *) -1;
822 #endif /* SHARED */
824 if (llp != NULL && *llp != '\0')
826 size_t nllp;
827 const char *cp = llp;
828 char *llp_tmp;
830 #ifdef SHARED
831 /* Expand DSTs. */
832 size_t cnt = DL_DST_COUNT (llp, 1);
833 if (__builtin_expect (cnt == 0, 1))
834 llp_tmp = strdupa (llp);
835 else
837 /* Determine the length of the substituted string. */
838 size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
840 /* Allocate the necessary memory. */
841 llp_tmp = (char *) alloca (total + 1);
842 llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
844 #else
845 llp_tmp = strdupa (llp);
846 #endif
848 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
849 elements it has. */
850 nllp = 1;
851 while (*cp)
853 if (*cp == ':' || *cp == ';')
854 ++nllp;
855 ++cp;
858 env_path_list.dirs = (struct r_search_path_elem **)
859 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
860 if (env_path_list.dirs == NULL)
862 errstring = N_("cannot create cache for search path");
863 goto signal_error;
866 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
867 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
868 NULL);
870 if (env_path_list.dirs[0] == NULL)
872 free (env_path_list.dirs);
873 env_path_list.dirs = (void *) -1;
876 env_path_list.malloced = 0;
878 else
879 env_path_list.dirs = (void *) -1;
883 static void
884 __attribute__ ((noreturn, noinline))
885 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
886 const char *msg, struct r_debug *r, Lmid_t nsid)
888 /* The file might already be closed. */
889 if (fd != -1)
890 (void) __close (fd);
891 if (l != NULL && l->l_origin != (char *) -1l)
892 free ((char *) l->l_origin);
893 free (l);
894 free (realname);
896 if (r != NULL)
898 r->r_state = RT_CONSISTENT;
899 _dl_debug_state ();
900 LIBC_PROBE (map_failed, 2, nsid, r);
903 _dl_signal_error (code, name, NULL, msg);
907 /* Map in the shared object NAME, actually located in REALNAME, and already
908 opened on FD. */
910 #ifndef EXTERNAL_MAP_FROM_FD
911 static
912 #endif
913 struct link_map *
914 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
915 char *realname, struct link_map *loader, int l_type,
916 int mode, void **stack_endp, Lmid_t nsid)
918 struct link_map *l = NULL;
919 const ElfW(Ehdr) *header;
920 const ElfW(Phdr) *phdr;
921 const ElfW(Phdr) *ph;
922 size_t maplength;
923 int type;
924 struct stat64 st;
925 /* Initialize to keep the compiler happy. */
926 const char *errstring = NULL;
927 int errval = 0;
928 struct r_debug *r = _dl_debug_initialize (0, nsid);
929 bool make_consistent = false;
931 /* Get file information. */
932 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
934 errstring = N_("cannot stat shared object");
935 call_lose_errno:
936 errval = errno;
937 call_lose:
938 lose (errval, fd, name, realname, l, errstring,
939 make_consistent ? r : NULL, nsid);
942 /* Look again to see if the real name matched another already loaded. */
943 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
944 if (l->l_removed == 0 && l->l_ino == st.st_ino && l->l_dev == st.st_dev)
946 /* The object is already loaded.
947 Just bump its reference count and return it. */
948 __close (fd);
950 /* If the name is not in the list of names for this object add
951 it. */
952 free (realname);
953 add_name_to_object (l, name);
955 return l;
958 #ifdef SHARED
959 /* When loading into a namespace other than the base one we must
960 avoid loading ld.so since there can only be one copy. Ever. */
961 if (__builtin_expect (nsid != LM_ID_BASE, 0)
962 && ((st.st_ino == GL(dl_rtld_map).l_ino
963 && st.st_dev == GL(dl_rtld_map).l_dev)
964 || _dl_name_match_p (name, &GL(dl_rtld_map))))
966 /* This is indeed ld.so. Create a new link_map which refers to
967 the real one for almost everything. */
968 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
969 if (l == NULL)
970 goto fail_new;
972 /* Refer to the real descriptor. */
973 l->l_real = &GL(dl_rtld_map);
975 /* No need to bump the refcount of the real object, ld.so will
976 never be unloaded. */
977 __close (fd);
979 /* Add the map for the mirrored object to the object list. */
980 _dl_add_to_namespace_list (l, nsid);
982 return l;
984 #endif
986 if (mode & RTLD_NOLOAD)
988 /* We are not supposed to load the object unless it is already
989 loaded. So return now. */
990 free (realname);
991 __close (fd);
992 return NULL;
995 /* Print debugging message. */
996 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
997 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
999 /* This is the ELF header. We read it in `open_verify'. */
1000 header = (void *) fbp->buf;
1002 #ifndef MAP_ANON
1003 # define MAP_ANON 0
1004 if (_dl_zerofd == -1)
1006 _dl_zerofd = _dl_sysdep_open_zero_fill ();
1007 if (_dl_zerofd == -1)
1009 free (realname);
1010 __close (fd);
1011 _dl_signal_error (errno, NULL, NULL,
1012 N_("cannot open zero fill device"));
1015 #endif
1017 /* Signal that we are going to add new objects. */
1018 if (r->r_state == RT_CONSISTENT)
1020 #ifdef SHARED
1021 /* Auditing checkpoint: we are going to add new objects. */
1022 if ((mode & __RTLD_AUDIT) == 0
1023 && __builtin_expect (GLRO(dl_naudit) > 0, 0))
1025 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
1026 /* Do not call the functions for any auditing object. */
1027 if (head->l_auditing == 0)
1029 struct audit_ifaces *afct = GLRO(dl_audit);
1030 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1032 if (afct->activity != NULL)
1033 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
1035 afct = afct->next;
1039 #endif
1041 /* Notify the debugger we have added some objects. We need to
1042 call _dl_debug_initialize in a static program in case dynamic
1043 linking has not been used before. */
1044 r->r_state = RT_ADD;
1045 _dl_debug_state ();
1046 LIBC_PROBE (map_start, 2, nsid, r);
1047 make_consistent = true;
1049 else
1050 assert (r->r_state == RT_ADD);
1052 /* Enter the new object in the list of loaded objects. */
1053 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1054 if (__builtin_expect (l == NULL, 0))
1056 #ifdef SHARED
1057 fail_new:
1058 #endif
1059 errstring = N_("cannot create shared object descriptor");
1060 goto call_lose_errno;
1063 /* Extract the remaining details we need from the ELF header
1064 and then read in the program header table. */
1065 l->l_entry = header->e_entry;
1066 type = header->e_type;
1067 l->l_phnum = header->e_phnum;
1069 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1070 if (header->e_phoff + maplength <= (size_t) fbp->len)
1071 phdr = (void *) (fbp->buf + header->e_phoff);
1072 else
1074 phdr = alloca (maplength);
1075 __lseek (fd, header->e_phoff, SEEK_SET);
1076 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1078 errstring = N_("cannot read file data");
1079 goto call_lose_errno;
1083 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1084 * executable. Other platforms default to a nonexecutable stack and don't
1085 * need PT_GNU_STACK to do so. */
1086 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1089 /* Scan the program header table, collecting its load commands. */
1090 struct loadcmd
1092 ElfW(Addr) mapstart, mapend, dataend, allocend;
1093 off_t mapoff;
1094 int prot;
1095 } loadcmds[l->l_phnum], *c;
1096 size_t nloadcmds = 0;
1097 bool has_holes = false;
1099 /* The struct is initialized to zero so this is not necessary:
1100 l->l_ld = 0;
1101 l->l_phdr = 0;
1102 l->l_addr = 0; */
1103 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1104 switch (ph->p_type)
1106 /* These entries tell us where to find things once the file's
1107 segments are mapped in. We record the addresses it says
1108 verbatim, and later correct for the run-time load address. */
1109 case PT_DYNAMIC:
1110 l->l_ld = (void *) ph->p_vaddr;
1111 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1112 break;
1114 case PT_PHDR:
1115 l->l_phdr = (void *) ph->p_vaddr;
1116 break;
1118 case PT_LOAD:
1119 /* A load command tells us to map in part of the file.
1120 We record the load commands and process them all later. */
1121 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
1124 errstring = N_("ELF load command alignment not page-aligned");
1125 goto call_lose;
1127 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
1128 & (ph->p_align - 1)) != 0, 0))
1130 errstring
1131 = N_("ELF load command address/offset not properly aligned");
1132 goto call_lose;
1135 c = &loadcmds[nloadcmds++];
1136 c->mapstart = ph->p_vaddr & ~(GLRO(dl_pagesize) - 1);
1137 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
1138 & ~(GLRO(dl_pagesize) - 1));
1139 c->dataend = ph->p_vaddr + ph->p_filesz;
1140 c->allocend = ph->p_vaddr + ph->p_memsz;
1141 c->mapoff = ph->p_offset & ~(GLRO(dl_pagesize) - 1);
1143 /* Determine whether there is a gap between the last segment
1144 and this one. */
1145 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1146 has_holes = true;
1148 /* Optimize a common case. */
1149 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1150 c->prot = (PF_TO_PROT
1151 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1152 #else
1153 c->prot = 0;
1154 if (ph->p_flags & PF_R)
1155 c->prot |= PROT_READ;
1156 if (ph->p_flags & PF_W)
1157 c->prot |= PROT_WRITE;
1158 if (ph->p_flags & PF_X)
1159 c->prot |= PROT_EXEC;
1160 #endif
1161 break;
1163 case PT_TLS:
1164 if (ph->p_memsz == 0)
1165 /* Nothing to do for an empty segment. */
1166 break;
1168 l->l_tls_blocksize = ph->p_memsz;
1169 l->l_tls_align = ph->p_align;
1170 if (ph->p_align == 0)
1171 l->l_tls_firstbyte_offset = 0;
1172 else
1173 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1174 l->l_tls_initimage_size = ph->p_filesz;
1175 /* Since we don't know the load address yet only store the
1176 offset. We will adjust it later. */
1177 l->l_tls_initimage = (void *) ph->p_vaddr;
1179 /* If not loading the initial set of shared libraries,
1180 check whether we should permit loading a TLS segment. */
1181 if (__builtin_expect (l->l_type == lt_library, 1)
1182 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1183 not set up TLS data structures, so don't use them now. */
1184 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1186 /* Assign the next available module ID. */
1187 l->l_tls_modid = _dl_next_tls_modid ();
1188 break;
1191 #ifdef SHARED
1192 if (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0)
1193 /* We are loading the executable itself when the dynamic linker
1194 was executed directly. The setup will happen later. */
1195 break;
1197 # ifdef _LIBC_REENTRANT
1198 /* In a static binary there is no way to tell if we dynamically
1199 loaded libpthread. */
1200 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1201 # endif
1202 #endif
1204 /* We have not yet loaded libpthread.
1205 We can do the TLS setup right now! */
1207 void *tcb;
1209 /* The first call allocates TLS bookkeeping data structures.
1210 Then we allocate the TCB for the initial thread. */
1211 if (__builtin_expect (_dl_tls_setup (), 0)
1212 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1215 errval = ENOMEM;
1216 errstring = N_("\
1217 cannot allocate TLS data structures for initial thread");
1218 goto call_lose;
1221 /* Now we install the TCB in the thread register. */
1222 errstring = TLS_INIT_TP (tcb, 0);
1223 if (__builtin_expect (errstring == NULL, 1))
1225 /* Now we are all good. */
1226 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1227 break;
1230 /* The kernel is too old or somesuch. */
1231 errval = 0;
1232 _dl_deallocate_tls (tcb, 1);
1233 goto call_lose;
1236 /* Uh-oh, the binary expects TLS support but we cannot
1237 provide it. */
1238 errval = 0;
1239 errstring = N_("cannot handle TLS data");
1240 goto call_lose;
1241 break;
1243 case PT_GNU_STACK:
1244 stack_flags = ph->p_flags;
1245 break;
1247 case PT_GNU_RELRO:
1248 l->l_relro_addr = ph->p_vaddr;
1249 l->l_relro_size = ph->p_memsz;
1250 break;
1253 if (__builtin_expect (nloadcmds == 0, 0))
1255 /* This only happens for a bogus object that will be caught with
1256 another error below. But we don't want to go through the
1257 calculations below using NLOADCMDS - 1. */
1258 errstring = N_("object file has no loadable segments");
1259 goto call_lose;
1262 /* Now process the load commands and map segments into memory. */
1263 c = loadcmds;
1265 /* Length of the sections to be loaded. */
1266 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1268 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1270 /* This is a position-independent shared object. We can let the
1271 kernel map it anywhere it likes, but we must have space for all
1272 the segments in their specified positions relative to the first.
1273 So we map the first segment without MAP_FIXED, but with its
1274 extent increased to cover all the segments. Then we remove
1275 access from excess portion, and there is known sufficient space
1276 there to remap from the later segments.
1278 As a refinement, sometimes we have an address that we would
1279 prefer to map such objects at; but this is only a preference,
1280 the OS can do whatever it likes. */
1281 ElfW(Addr) mappref;
1282 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1283 c->mapstart & GLRO(dl_use_load_bias))
1284 - MAP_BASE_ADDR (l));
1286 /* Remember which part of the address space this object uses. */
1287 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1288 c->prot,
1289 MAP_COPY|MAP_FILE,
1290 fd, c->mapoff);
1291 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1293 map_error:
1294 errstring = N_("failed to map segment from shared object");
1295 goto call_lose_errno;
1298 l->l_map_end = l->l_map_start + maplength;
1299 l->l_addr = l->l_map_start - c->mapstart;
1301 if (has_holes)
1302 /* Change protection on the excess portion to disallow all access;
1303 the portions we do not remap later will be inaccessible as if
1304 unallocated. Then jump into the normal segment-mapping loop to
1305 handle the portion of the segment past the end of the file
1306 mapping. */
1307 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1308 loadcmds[nloadcmds - 1].mapstart - c->mapend,
1309 PROT_NONE);
1311 l->l_contiguous = 1;
1313 goto postmap;
1316 /* This object is loaded at a fixed address. This must never
1317 happen for objects loaded with dlopen(). */
1318 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1320 errstring = N_("cannot dynamically load executable");
1321 goto call_lose;
1324 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1325 fixed. */
1326 ELF_FIXED_ADDRESS (loader, c->mapstart);
1329 /* Remember which part of the address space this object uses. */
1330 l->l_map_start = c->mapstart + l->l_addr;
1331 l->l_map_end = l->l_map_start + maplength;
1332 l->l_contiguous = !has_holes;
1334 while (c < &loadcmds[nloadcmds])
1336 if (c->mapend > c->mapstart
1337 /* Map the segment contents from the file. */
1338 && (__mmap ((void *) (l->l_addr + c->mapstart),
1339 c->mapend - c->mapstart, c->prot,
1340 MAP_FIXED|MAP_COPY|MAP_FILE,
1341 fd, c->mapoff)
1342 == MAP_FAILED))
1343 goto map_error;
1345 postmap:
1346 if (c->prot & PROT_EXEC)
1347 l->l_text_end = l->l_addr + c->mapend;
1349 if (l->l_phdr == 0
1350 && (ElfW(Off)) c->mapoff <= header->e_phoff
1351 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1352 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1353 /* Found the program header in this segment. */
1354 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1356 if (c->allocend > c->dataend)
1358 /* Extra zero pages should appear at the end of this segment,
1359 after the data mapped from the file. */
1360 ElfW(Addr) zero, zeroend, zeropage;
1362 zero = l->l_addr + c->dataend;
1363 zeroend = l->l_addr + c->allocend;
1364 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1365 & ~(GLRO(dl_pagesize) - 1));
1367 if (zeroend < zeropage)
1368 /* All the extra data is in the last page of the segment.
1369 We can just zero it. */
1370 zeropage = zeroend;
1372 if (zeropage > zero)
1374 /* Zero the final part of the last page of the segment. */
1375 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1377 /* Dag nab it. */
1378 if (__mprotect ((caddr_t) (zero
1379 & ~(GLRO(dl_pagesize) - 1)),
1380 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1382 errstring = N_("cannot change memory protections");
1383 goto call_lose_errno;
1386 memset ((void *) zero, '\0', zeropage - zero);
1387 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1388 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1389 GLRO(dl_pagesize), c->prot);
1392 if (zeroend > zeropage)
1394 /* Map the remaining zero pages in from the zero fill FD. */
1395 caddr_t mapat;
1396 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1397 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1398 -1, 0);
1399 if (__builtin_expect (mapat == MAP_FAILED, 0))
1401 errstring = N_("cannot map zero-fill pages");
1402 goto call_lose_errno;
1407 ++c;
1411 if (l->l_ld == 0)
1413 if (__builtin_expect (type == ET_DYN, 0))
1415 errstring = N_("object file has no dynamic section");
1416 goto call_lose;
1419 else
1420 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1422 elf_get_dynamic_info (l, NULL);
1424 /* Make sure we are not dlopen'ing an object that has the
1425 DF_1_NOOPEN flag set. */
1426 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1427 && (mode & __RTLD_DLOPEN))
1429 /* We are not supposed to load this object. Free all resources. */
1430 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1432 if (!l->l_libname->dont_free)
1433 free (l->l_libname);
1435 if (l->l_phdr_allocated)
1436 free ((void *) l->l_phdr);
1438 errstring = N_("shared object cannot be dlopen()ed");
1439 goto call_lose;
1442 if (l->l_phdr == NULL)
1444 /* The program header is not contained in any of the segments.
1445 We have to allocate memory ourself and copy it over from out
1446 temporary place. */
1447 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1448 * sizeof (ElfW(Phdr)));
1449 if (newp == NULL)
1451 errstring = N_("cannot allocate memory for program header");
1452 goto call_lose_errno;
1455 l->l_phdr = memcpy (newp, phdr,
1456 (header->e_phnum * sizeof (ElfW(Phdr))));
1457 l->l_phdr_allocated = 1;
1459 else
1460 /* Adjust the PT_PHDR value by the runtime load address. */
1461 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1463 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1465 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso),
1466 0) != 0)
1468 errstring = N_("invalid caller");
1469 goto call_lose;
1472 /* The stack is presently not executable, but this module
1473 requires that it be executable. We must change the
1474 protection of the variable which contains the flags used in
1475 the mprotect calls. */
1476 #ifdef SHARED
1477 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1479 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1480 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1482 struct link_map *const m = &GL(dl_rtld_map);
1483 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1484 + m->l_relro_size)
1485 & -GLRO(dl_pagesize));
1486 if (__builtin_expect (p + s <= relro_end, 1))
1488 /* The variable lies in the region protected by RELRO. */
1489 __mprotect ((void *) p, s, PROT_READ|PROT_WRITE);
1490 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1491 __mprotect ((void *) p, s, PROT_READ);
1493 else
1494 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1496 else
1497 #endif
1498 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1500 #ifdef check_consistency
1501 check_consistency ();
1502 #endif
1504 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1505 if (errval)
1507 errstring = N_("\
1508 cannot enable executable stack as shared object requires");
1509 goto call_lose;
1513 /* Adjust the address of the TLS initialization image. */
1514 if (l->l_tls_initimage != NULL)
1515 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1517 /* We are done mapping in the file. We no longer need the descriptor. */
1518 if (__builtin_expect (__close (fd) != 0, 0))
1520 errstring = N_("cannot close file descriptor");
1521 goto call_lose_errno;
1523 /* Signal that we closed the file. */
1524 fd = -1;
1526 if (l->l_type == lt_library && type == ET_EXEC)
1527 l->l_type = lt_executable;
1529 l->l_entry += l->l_addr;
1531 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1532 _dl_debug_printf ("\
1533 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1534 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1535 (int) sizeof (void *) * 2,
1536 (unsigned long int) l->l_ld,
1537 (int) sizeof (void *) * 2,
1538 (unsigned long int) l->l_addr,
1539 (int) sizeof (void *) * 2, maplength,
1540 (int) sizeof (void *) * 2,
1541 (unsigned long int) l->l_entry,
1542 (int) sizeof (void *) * 2,
1543 (unsigned long int) l->l_phdr,
1544 (int) sizeof (void *) * 2, l->l_phnum);
1546 /* Set up the symbol hash table. */
1547 _dl_setup_hash (l);
1549 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1550 have to do this for the main map. */
1551 if ((mode & RTLD_DEEPBIND) == 0
1552 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1553 && &l->l_searchlist != l->l_scope[0])
1555 /* Create an appropriate searchlist. It contains only this map.
1556 This is the definition of DT_SYMBOLIC in SysVr4. */
1557 l->l_symbolic_searchlist.r_list[0] = l;
1558 l->l_symbolic_searchlist.r_nlist = 1;
1560 /* Now move the existing entries one back. */
1561 memmove (&l->l_scope[1], &l->l_scope[0],
1562 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1564 /* Now add the new entry. */
1565 l->l_scope[0] = &l->l_symbolic_searchlist;
1568 /* Remember whether this object must be initialized first. */
1569 if (l->l_flags_1 & DF_1_INITFIRST)
1570 GL(dl_initfirst) = l;
1572 /* Finally the file information. */
1573 l->l_dev = st.st_dev;
1574 l->l_ino = st.st_ino;
1576 /* When we profile the SONAME might be needed for something else but
1577 loading. Add it right away. */
1578 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1579 && l->l_info[DT_SONAME] != NULL)
1580 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1581 + l->l_info[DT_SONAME]->d_un.d_val));
1583 /* Now that the object is fully initialized add it to the object list. */
1584 _dl_add_to_namespace_list (l, nsid);
1586 #ifdef SHARED
1587 /* Auditing checkpoint: we have a new object. */
1588 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
1589 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1591 struct audit_ifaces *afct = GLRO(dl_audit);
1592 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1594 if (afct->objopen != NULL)
1596 l->l_audit[cnt].bindflags
1597 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1599 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1602 afct = afct->next;
1605 #endif
1607 return l;
1610 /* Print search path. */
1611 static void
1612 print_search_path (struct r_search_path_elem **list,
1613 const char *what, const char *name)
1615 char buf[max_dirnamelen + max_capstrlen];
1616 int first = 1;
1618 _dl_debug_printf (" search path=");
1620 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1622 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1623 size_t cnt;
1625 for (cnt = 0; cnt < ncapstr; ++cnt)
1626 if ((*list)->status[cnt] != nonexisting)
1628 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1629 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1630 cp[0] = '\0';
1631 else
1632 cp[-1] = '\0';
1634 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1635 first = 0;
1638 ++list;
1641 if (name != NULL)
1642 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1643 name[0] ? name : rtld_progname);
1644 else
1645 _dl_debug_printf_c ("\t\t(%s)\n", what);
1648 /* Open a file and verify it is an ELF file for this architecture. We
1649 ignore only ELF files for other architectures. Non-ELF files and
1650 ELF files with different header information cause fatal errors since
1651 this could mean there is something wrong in the installation and the
1652 user might want to know about this. */
1653 static int
1654 open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
1655 int whatcode, bool *found_other_class, bool free_name)
1657 /* This is the expected ELF header. */
1658 #define ELF32_CLASS ELFCLASS32
1659 #define ELF64_CLASS ELFCLASS64
1660 #ifndef VALID_ELF_HEADER
1661 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1662 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1663 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1664 #elif defined MORE_ELF_HEADER_DATA
1665 MORE_ELF_HEADER_DATA;
1666 #endif
1667 static const unsigned char expected[EI_NIDENT] =
1669 [EI_MAG0] = ELFMAG0,
1670 [EI_MAG1] = ELFMAG1,
1671 [EI_MAG2] = ELFMAG2,
1672 [EI_MAG3] = ELFMAG3,
1673 [EI_CLASS] = ELFW(CLASS),
1674 [EI_DATA] = byteorder,
1675 [EI_VERSION] = EV_CURRENT,
1676 [EI_OSABI] = ELFOSABI_SYSV,
1677 [EI_ABIVERSION] = 0
1679 static const struct
1681 ElfW(Word) vendorlen;
1682 ElfW(Word) datalen;
1683 ElfW(Word) type;
1684 char vendor[4];
1685 } expected_note = { 4, 16, 1, "GNU" };
1686 /* Initialize it to make the compiler happy. */
1687 const char *errstring = NULL;
1688 int errval = 0;
1690 #ifdef SHARED
1691 /* Give the auditing libraries a chance. */
1692 if (__builtin_expect (GLRO(dl_naudit) > 0, 0) && whatcode != 0
1693 && loader->l_auditing == 0)
1695 struct audit_ifaces *afct = GLRO(dl_audit);
1696 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1698 if (afct->objsearch != NULL)
1700 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1701 whatcode);
1702 if (name == NULL)
1703 /* Ignore the path. */
1704 return -1;
1707 afct = afct->next;
1710 #endif
1712 /* Open the file. We always open files read-only. */
1713 int fd = __open (name, O_RDONLY | O_CLOEXEC);
1714 if (fd != -1)
1716 ElfW(Ehdr) *ehdr;
1717 ElfW(Phdr) *phdr, *ph;
1718 ElfW(Word) *abi_note;
1719 unsigned int osversion;
1720 size_t maplength;
1722 /* We successfully openened the file. Now verify it is a file
1723 we can use. */
1724 __set_errno (0);
1725 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1727 /* This is where the ELF header is loaded. */
1728 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1729 ehdr = (ElfW(Ehdr) *) fbp->buf;
1731 /* Now run the tests. */
1732 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1734 errval = errno;
1735 errstring = (errval == 0
1736 ? N_("file too short") : N_("cannot read file data"));
1737 call_lose:
1738 if (free_name)
1740 char *realname = (char *) name;
1741 name = strdupa (realname);
1742 free (realname);
1744 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1747 /* See whether the ELF header is what we expect. */
1748 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1749 EI_ABIVERSION)
1750 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1751 ehdr->e_ident[EI_ABIVERSION])
1752 || memcmp (&ehdr->e_ident[EI_PAD],
1753 &expected[EI_PAD],
1754 EI_NIDENT - EI_PAD) != 0,
1757 /* Something is wrong. */
1758 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1759 if (*magp !=
1760 #if BYTE_ORDER == LITTLE_ENDIAN
1761 ((ELFMAG0 << (EI_MAG0 * 8)) |
1762 (ELFMAG1 << (EI_MAG1 * 8)) |
1763 (ELFMAG2 << (EI_MAG2 * 8)) |
1764 (ELFMAG3 << (EI_MAG3 * 8)))
1765 #else
1766 ((ELFMAG0 << (EI_MAG3 * 8)) |
1767 (ELFMAG1 << (EI_MAG2 * 8)) |
1768 (ELFMAG2 << (EI_MAG1 * 8)) |
1769 (ELFMAG3 << (EI_MAG0 * 8)))
1770 #endif
1772 errstring = N_("invalid ELF header");
1773 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1775 /* This is not a fatal error. On architectures where
1776 32-bit and 64-bit binaries can be run this might
1777 happen. */
1778 *found_other_class = true;
1779 goto close_and_out;
1781 else if (ehdr->e_ident[EI_DATA] != byteorder)
1783 if (BYTE_ORDER == BIG_ENDIAN)
1784 errstring = N_("ELF file data encoding not big-endian");
1785 else
1786 errstring = N_("ELF file data encoding not little-endian");
1788 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1789 errstring
1790 = N_("ELF file version ident does not match current one");
1791 /* XXX We should be able so set system specific versions which are
1792 allowed here. */
1793 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1794 errstring = N_("ELF file OS ABI invalid");
1795 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1796 ehdr->e_ident[EI_ABIVERSION]))
1797 errstring = N_("ELF file ABI version invalid");
1798 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1799 EI_NIDENT - EI_PAD) != 0)
1800 errstring = N_("nonzero padding in e_ident");
1801 else
1802 /* Otherwise we don't know what went wrong. */
1803 errstring = N_("internal error");
1805 goto call_lose;
1808 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1810 errstring = N_("ELF file version does not match current one");
1811 goto call_lose;
1813 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1814 goto close_and_out;
1815 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1816 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1818 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1819 goto call_lose;
1821 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1822 != sizeof (ElfW(Phdr)))
1824 errstring = N_("ELF file's phentsize not the expected size");
1825 goto call_lose;
1828 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1829 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1830 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1831 else
1833 phdr = alloca (maplength);
1834 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1835 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1837 read_error:
1838 errval = errno;
1839 errstring = N_("cannot read file data");
1840 goto call_lose;
1844 /* Check .note.ABI-tag if present. */
1845 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1846 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1848 ElfW(Addr) size = ph->p_filesz;
1850 if (ph->p_offset + size <= (size_t) fbp->len)
1851 abi_note = (void *) (fbp->buf + ph->p_offset);
1852 else
1854 abi_note = alloca (size);
1855 __lseek (fd, ph->p_offset, SEEK_SET);
1856 if (__libc_read (fd, (void *) abi_note, size) != size)
1857 goto read_error;
1860 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1862 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1863 ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
1864 + ROUND (abi_note[0])
1865 + ROUND (abi_note[1]);
1867 if (size - 32 < note_size)
1869 size = 0;
1870 break;
1872 size -= note_size;
1873 abi_note = (void *) abi_note + note_size;
1876 if (size == 0)
1877 continue;
1879 osversion = (abi_note[5] & 0xff) * 65536
1880 + (abi_note[6] & 0xff) * 256
1881 + (abi_note[7] & 0xff);
1882 if (abi_note[4] != __ABI_TAG_OS
1883 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1885 close_and_out:
1886 __close (fd);
1887 __set_errno (ENOENT);
1888 fd = -1;
1891 break;
1895 return fd;
1898 /* Try to open NAME in one of the directories in *DIRSP.
1899 Return the fd, or -1. If successful, fill in *REALNAME
1900 with the malloc'd full directory name. If it turns out
1901 that none of the directories in *DIRSP exists, *DIRSP is
1902 replaced with (void *) -1, and the old value is free()d
1903 if MAY_FREE_DIRS is true. */
1905 static int
1906 open_path (const char *name, size_t namelen, int secure,
1907 struct r_search_path_struct *sps, char **realname,
1908 struct filebuf *fbp, struct link_map *loader, int whatcode,
1909 bool *found_other_class)
1911 struct r_search_path_elem **dirs = sps->dirs;
1912 char *buf;
1913 int fd = -1;
1914 const char *current_what = NULL;
1915 int any = 0;
1917 if (__builtin_expect (dirs == NULL, 0))
1918 /* We're called before _dl_init_paths when loading the main executable
1919 given on the command line when rtld is run directly. */
1920 return -1;
1922 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1925 struct r_search_path_elem *this_dir = *dirs;
1926 size_t buflen = 0;
1927 size_t cnt;
1928 char *edp;
1929 int here_any = 0;
1930 int err;
1932 /* If we are debugging the search for libraries print the path
1933 now if it hasn't happened now. */
1934 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1935 && current_what != this_dir->what)
1937 current_what = this_dir->what;
1938 print_search_path (dirs, current_what, this_dir->where);
1941 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1942 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1944 /* Skip this directory if we know it does not exist. */
1945 if (this_dir->status[cnt] == nonexisting)
1946 continue;
1948 buflen =
1949 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1950 capstr[cnt].len),
1951 name, namelen)
1952 - buf);
1954 /* Print name we try if this is wanted. */
1955 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1956 _dl_debug_printf (" trying file=%s\n", buf);
1958 fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
1959 false);
1960 if (this_dir->status[cnt] == unknown)
1962 if (fd != -1)
1963 this_dir->status[cnt] = existing;
1964 /* Do not update the directory information when loading
1965 auditing code. We must try to disturb the program as
1966 little as possible. */
1967 else if (loader == NULL
1968 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1970 /* We failed to open machine dependent library. Let's
1971 test whether there is any directory at all. */
1972 struct stat64 st;
1974 buf[buflen - namelen - 1] = '\0';
1976 if (__xstat64 (_STAT_VER, buf, &st) != 0
1977 || ! S_ISDIR (st.st_mode))
1978 /* The directory does not exist or it is no directory. */
1979 this_dir->status[cnt] = nonexisting;
1980 else
1981 this_dir->status[cnt] = existing;
1985 /* Remember whether we found any existing directory. */
1986 here_any |= this_dir->status[cnt] != nonexisting;
1988 if (fd != -1 && __builtin_expect (secure, 0)
1989 && INTUSE(__libc_enable_secure))
1991 /* This is an extra security effort to make sure nobody can
1992 preload broken shared objects which are in the trusted
1993 directories and so exploit the bugs. */
1994 struct stat64 st;
1996 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1997 || (st.st_mode & S_ISUID) == 0)
1999 /* The shared object cannot be tested for being SUID
2000 or this bit is not set. In this case we must not
2001 use this object. */
2002 __close (fd);
2003 fd = -1;
2004 /* We simply ignore the file, signal this by setting
2005 the error value which would have been set by `open'. */
2006 errno = ENOENT;
2011 if (fd != -1)
2013 *realname = (char *) malloc (buflen);
2014 if (*realname != NULL)
2016 memcpy (*realname, buf, buflen);
2017 return fd;
2019 else
2021 /* No memory for the name, we certainly won't be able
2022 to load and link it. */
2023 __close (fd);
2024 return -1;
2027 if (here_any && (err = errno) != ENOENT && err != EACCES)
2028 /* The file exists and is readable, but something went wrong. */
2029 return -1;
2031 /* Remember whether we found anything. */
2032 any |= here_any;
2034 while (*++dirs != NULL);
2036 /* Remove the whole path if none of the directories exists. */
2037 if (__builtin_expect (! any, 0))
2039 /* Paths which were allocated using the minimal malloc() in ld.so
2040 must not be freed using the general free() in libc. */
2041 if (sps->malloced)
2042 free (sps->dirs);
2044 /* rtld_search_dirs is attribute_relro, therefore avoid writing
2045 into it. */
2046 if (sps != &rtld_search_dirs)
2047 sps->dirs = (void *) -1;
2050 return -1;
2053 /* Map in the shared object file NAME. */
2055 struct link_map *
2056 internal_function
2057 _dl_map_object (struct link_map *loader, const char *name,
2058 int type, int trace_mode, int mode, Lmid_t nsid)
2060 int fd;
2061 char *realname;
2062 char *name_copy;
2063 struct link_map *l;
2064 struct filebuf fb;
2066 assert (nsid >= 0);
2067 assert (nsid < GL(dl_nns));
2069 /* Look for this name among those already loaded. */
2070 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
2072 /* If the requested name matches the soname of a loaded object,
2073 use that object. Elide this check for names that have not
2074 yet been opened. */
2075 if (__builtin_expect (l->l_faked, 0) != 0
2076 || __builtin_expect (l->l_removed, 0) != 0)
2077 continue;
2078 if (!_dl_name_match_p (name, l))
2080 const char *soname;
2082 if (__builtin_expect (l->l_soname_added, 1)
2083 || l->l_info[DT_SONAME] == NULL)
2084 continue;
2086 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
2087 + l->l_info[DT_SONAME]->d_un.d_val);
2088 if (strcmp (name, soname) != 0)
2089 continue;
2091 /* We have a match on a new name -- cache it. */
2092 add_name_to_object (l, soname);
2093 l->l_soname_added = 1;
2096 /* We have a match. */
2097 return l;
2100 /* Display information if we are debugging. */
2101 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
2102 && loader != NULL)
2103 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
2104 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
2105 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
2106 name, nsid, loader->l_name[0]
2107 ? loader->l_name : rtld_progname, loader->l_ns);
2109 #ifdef SHARED
2110 /* Give the auditing libraries a chance to change the name before we
2111 try anything. */
2112 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
2113 && (loader == NULL || loader->l_auditing == 0))
2115 struct audit_ifaces *afct = GLRO(dl_audit);
2116 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2118 if (afct->objsearch != NULL)
2120 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
2121 LA_SER_ORIG);
2122 if (name == NULL)
2124 /* Do not try anything further. */
2125 fd = -1;
2126 goto no_file;
2130 afct = afct->next;
2133 #endif
2135 /* Will be true if we found a DSO which is of the other ELF class. */
2136 bool found_other_class = false;
2138 if (strchr (name, '/') == NULL)
2140 /* Search for NAME in several places. */
2142 size_t namelen = strlen (name) + 1;
2144 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2145 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2147 fd = -1;
2149 /* When the object has the RUNPATH information we don't use any
2150 RPATHs. */
2151 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2153 /* This is the executable's map (if there is one). Make sure that
2154 we do not look at it twice. */
2155 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2156 bool did_main_map = false;
2158 /* First try the DT_RPATH of the dependent object that caused NAME
2159 to be loaded. Then that object's dependent, and on up. */
2160 for (l = loader; l; l = l->l_loader)
2161 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2163 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2164 &l->l_rpath_dirs,
2165 &realname, &fb, loader, LA_SER_RUNPATH,
2166 &found_other_class);
2167 if (fd != -1)
2168 break;
2170 did_main_map |= l == main_map;
2173 /* If dynamically linked, try the DT_RPATH of the executable
2174 itself. NB: we do this for lookups in any namespace. */
2175 if (fd == -1 && !did_main_map
2176 && main_map != NULL && main_map->l_type != lt_loaded
2177 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2178 "RPATH"))
2179 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2180 &main_map->l_rpath_dirs,
2181 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2182 &found_other_class);
2185 /* Try the LD_LIBRARY_PATH environment variable. */
2186 if (fd == -1 && env_path_list.dirs != (void *) -1)
2187 fd = open_path (name, namelen, mode & __RTLD_SECURE, &env_path_list,
2188 &realname, &fb,
2189 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2190 LA_SER_LIBPATH, &found_other_class);
2192 /* Look at the RUNPATH information for this binary. */
2193 if (fd == -1 && loader != NULL
2194 && cache_rpath (loader, &loader->l_runpath_dirs,
2195 DT_RUNPATH, "RUNPATH"))
2196 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2197 &loader->l_runpath_dirs, &realname, &fb, loader,
2198 LA_SER_RUNPATH, &found_other_class);
2200 if (fd == -1
2201 && (__builtin_expect (! (mode & __RTLD_SECURE), 1)
2202 || ! INTUSE(__libc_enable_secure))
2203 && __builtin_expect (GLRO(dl_inhibit_cache) == 0, 1))
2205 /* Check the list of libraries in the file /etc/ld.so.cache,
2206 for compatibility with Linux's ldconfig program. */
2207 const char *cached = _dl_load_cache_lookup (name);
2209 if (cached != NULL)
2211 #ifdef SHARED
2212 // XXX Correct to unconditionally default to namespace 0?
2213 l = (loader
2214 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2215 ?: &GL(dl_rtld_map));
2216 #else
2217 l = loader;
2218 #endif
2220 /* If the loader has the DF_1_NODEFLIB flag set we must not
2221 use a cache entry from any of these directories. */
2222 if (
2223 #ifndef SHARED
2224 /* 'l' is always != NULL for dynamically linked objects. */
2225 l != NULL &&
2226 #endif
2227 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
2229 const char *dirp = system_dirs;
2230 unsigned int cnt = 0;
2234 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2236 /* The prefix matches. Don't use the entry. */
2237 cached = NULL;
2238 break;
2241 dirp += system_dirs_len[cnt] + 1;
2242 ++cnt;
2244 while (cnt < nsystem_dirs_len);
2247 if (cached != NULL)
2249 fd = open_verify (cached,
2250 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2251 LA_SER_CONFIG, &found_other_class, false);
2252 if (__builtin_expect (fd != -1, 1))
2254 realname = local_strdup (cached);
2255 if (realname == NULL)
2257 __close (fd);
2258 fd = -1;
2265 /* Finally, try the default path. */
2266 if (fd == -1
2267 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2268 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
2269 && rtld_search_dirs.dirs != (void *) -1)
2270 fd = open_path (name, namelen, mode & __RTLD_SECURE, &rtld_search_dirs,
2271 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2273 /* Add another newline when we are tracing the library loading. */
2274 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2275 _dl_debug_printf ("\n");
2277 else
2279 /* The path may contain dynamic string tokens. */
2280 realname = (loader
2281 ? expand_dynamic_string_token (loader, name, 0)
2282 : local_strdup (name));
2283 if (realname == NULL)
2284 fd = -1;
2285 else
2287 fd = open_verify (realname, &fb,
2288 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
2289 &found_other_class, true);
2290 if (__builtin_expect (fd, 0) == -1)
2291 free (realname);
2295 #ifdef SHARED
2296 no_file:
2297 #endif
2298 /* In case the LOADER information has only been provided to get to
2299 the appropriate RUNPATH/RPATH information we do not need it
2300 anymore. */
2301 if (mode & __RTLD_CALLMAP)
2302 loader = NULL;
2304 if (__builtin_expect (fd, 0) == -1)
2306 if (trace_mode
2307 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
2309 /* We haven't found an appropriate library. But since we
2310 are only interested in the list of libraries this isn't
2311 so severe. Fake an entry with all the information we
2312 have. */
2313 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2315 /* Allocate a new object map. */
2316 if ((name_copy = local_strdup (name)) == NULL
2317 || (l = _dl_new_object (name_copy, name, type, loader,
2318 mode, nsid)) == NULL)
2320 free (name_copy);
2321 _dl_signal_error (ENOMEM, name, NULL,
2322 N_("cannot create shared object descriptor"));
2324 /* Signal that this is a faked entry. */
2325 l->l_faked = 1;
2326 /* Since the descriptor is initialized with zero we do not
2327 have do this here.
2328 l->l_reserved = 0; */
2329 l->l_buckets = &dummy_bucket;
2330 l->l_nbuckets = 1;
2331 l->l_relocated = 1;
2333 /* Enter the object in the object list. */
2334 _dl_add_to_namespace_list (l, nsid);
2336 return l;
2338 else if (found_other_class)
2339 _dl_signal_error (0, name, NULL,
2340 ELFW(CLASS) == ELFCLASS32
2341 ? N_("wrong ELF class: ELFCLASS64")
2342 : N_("wrong ELF class: ELFCLASS32"));
2343 else
2344 _dl_signal_error (errno, name, NULL,
2345 N_("cannot open shared object file"));
2348 void *stack_end = __libc_stack_end;
2349 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
2350 &stack_end, nsid);
2354 void
2355 internal_function
2356 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2358 if (counting)
2360 si->dls_cnt = 0;
2361 si->dls_size = 0;
2364 unsigned int idx = 0;
2365 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2366 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2367 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2369 if (sps->dirs != (void *) -1)
2371 struct r_search_path_elem **dirs = sps->dirs;
2374 const struct r_search_path_elem *const r = *dirs++;
2375 if (counting)
2377 si->dls_cnt++;
2378 si->dls_size += MAX (2, r->dirnamelen);
2380 else
2382 Dl_serpath *const sp = &si->dls_serpath[idx++];
2383 sp->dls_name = allocptr;
2384 if (r->dirnamelen < 2)
2385 *allocptr++ = r->dirnamelen ? '/' : '.';
2386 else
2387 allocptr = __mempcpy (allocptr,
2388 r->dirname, r->dirnamelen - 1);
2389 *allocptr++ = '\0';
2390 sp->dls_flags = flags;
2393 while (*dirs != NULL);
2397 /* When the object has the RUNPATH information we don't use any RPATHs. */
2398 if (loader->l_info[DT_RUNPATH] == NULL)
2400 /* First try the DT_RPATH of the dependent object that caused NAME
2401 to be loaded. Then that object's dependent, and on up. */
2403 struct link_map *l = loader;
2406 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2407 add_path (&l->l_rpath_dirs, XXX_RPATH);
2408 l = l->l_loader;
2410 while (l != NULL);
2412 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2413 if (loader->l_ns == LM_ID_BASE)
2415 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2416 if (l != NULL && l->l_type != lt_loaded && l != loader)
2417 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2418 add_path (&l->l_rpath_dirs, XXX_RPATH);
2422 /* Try the LD_LIBRARY_PATH environment variable. */
2423 add_path (&env_path_list, XXX_ENV);
2425 /* Look at the RUNPATH information for this binary. */
2426 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2427 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2429 /* XXX
2430 Here is where ld.so.cache gets checked, but we don't have
2431 a way to indicate that in the results for Dl_serinfo. */
2433 /* Finally, try the default path. */
2434 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2435 add_path (&rtld_search_dirs, XXX_default);
2437 if (counting)
2438 /* Count the struct size before the string area, which we didn't
2439 know before we completed dls_cnt. */
2440 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;