Fix invalid free of memory allocated during rtld init
[glibc.git] / elf / dl-load.c
blobdd182c9155acdec8e0398437ebe33c7f327548be
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2013 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");
800 /* During rtld init the memory is allocated by the stub malloc,
801 prevent any attempt to free it by the normal malloc. */
802 l->l_runpath_dirs.malloced = 0;
804 /* The RPATH is ignored. */
805 l->l_rpath_dirs.dirs = (void *) -1;
807 else
809 l->l_runpath_dirs.dirs = (void *) -1;
811 if (l->l_info[DT_RPATH])
813 /* Allocate room for the search path and fill in information
814 from RPATH. */
815 decompose_rpath (&l->l_rpath_dirs,
816 (const void *) (D_PTR (l, l_info[DT_STRTAB])
817 + l->l_info[DT_RPATH]->d_un.d_val),
818 l, "RPATH");
819 /* During rtld init the memory is allocated by the stub
820 malloc, prevent any attempt to free it by the normal
821 malloc. */
822 l->l_rpath_dirs.malloced = 0;
824 else
825 l->l_rpath_dirs.dirs = (void *) -1;
828 #endif /* SHARED */
830 if (llp != NULL && *llp != '\0')
832 size_t nllp;
833 const char *cp = llp;
834 char *llp_tmp;
836 #ifdef SHARED
837 /* Expand DSTs. */
838 size_t cnt = DL_DST_COUNT (llp, 1);
839 if (__builtin_expect (cnt == 0, 1))
840 llp_tmp = strdupa (llp);
841 else
843 /* Determine the length of the substituted string. */
844 size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
846 /* Allocate the necessary memory. */
847 llp_tmp = (char *) alloca (total + 1);
848 llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
850 #else
851 llp_tmp = strdupa (llp);
852 #endif
854 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
855 elements it has. */
856 nllp = 1;
857 while (*cp)
859 if (*cp == ':' || *cp == ';')
860 ++nllp;
861 ++cp;
864 env_path_list.dirs = (struct r_search_path_elem **)
865 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
866 if (env_path_list.dirs == NULL)
868 errstring = N_("cannot create cache for search path");
869 goto signal_error;
872 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
873 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
874 NULL);
876 if (env_path_list.dirs[0] == NULL)
878 free (env_path_list.dirs);
879 env_path_list.dirs = (void *) -1;
882 env_path_list.malloced = 0;
884 else
885 env_path_list.dirs = (void *) -1;
889 static void
890 __attribute__ ((noreturn, noinline))
891 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
892 const char *msg, struct r_debug *r, Lmid_t nsid)
894 /* The file might already be closed. */
895 if (fd != -1)
896 (void) __close (fd);
897 if (l != NULL && l->l_origin != (char *) -1l)
898 free ((char *) l->l_origin);
899 free (l);
900 free (realname);
902 if (r != NULL)
904 r->r_state = RT_CONSISTENT;
905 _dl_debug_state ();
906 LIBC_PROBE (map_failed, 2, nsid, r);
909 _dl_signal_error (code, name, NULL, msg);
913 /* Map in the shared object NAME, actually located in REALNAME, and already
914 opened on FD. */
916 #ifndef EXTERNAL_MAP_FROM_FD
917 static
918 #endif
919 struct link_map *
920 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
921 char *realname, struct link_map *loader, int l_type,
922 int mode, void **stack_endp, Lmid_t nsid)
924 struct link_map *l = NULL;
925 const ElfW(Ehdr) *header;
926 const ElfW(Phdr) *phdr;
927 const ElfW(Phdr) *ph;
928 size_t maplength;
929 int type;
930 struct stat64 st;
931 /* Initialize to keep the compiler happy. */
932 const char *errstring = NULL;
933 int errval = 0;
934 struct r_debug *r = _dl_debug_initialize (0, nsid);
935 bool make_consistent = false;
937 /* Get file information. */
938 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
940 errstring = N_("cannot stat shared object");
941 call_lose_errno:
942 errval = errno;
943 call_lose:
944 lose (errval, fd, name, realname, l, errstring,
945 make_consistent ? r : NULL, nsid);
948 /* Look again to see if the real name matched another already loaded. */
949 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
950 if (l->l_removed == 0 && l->l_ino == st.st_ino && l->l_dev == st.st_dev)
952 /* The object is already loaded.
953 Just bump its reference count and return it. */
954 __close (fd);
956 /* If the name is not in the list of names for this object add
957 it. */
958 free (realname);
959 add_name_to_object (l, name);
961 return l;
964 #ifdef SHARED
965 /* When loading into a namespace other than the base one we must
966 avoid loading ld.so since there can only be one copy. Ever. */
967 if (__builtin_expect (nsid != LM_ID_BASE, 0)
968 && ((st.st_ino == GL(dl_rtld_map).l_ino
969 && st.st_dev == GL(dl_rtld_map).l_dev)
970 || _dl_name_match_p (name, &GL(dl_rtld_map))))
972 /* This is indeed ld.so. Create a new link_map which refers to
973 the real one for almost everything. */
974 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
975 if (l == NULL)
976 goto fail_new;
978 /* Refer to the real descriptor. */
979 l->l_real = &GL(dl_rtld_map);
981 /* No need to bump the refcount of the real object, ld.so will
982 never be unloaded. */
983 __close (fd);
985 /* Add the map for the mirrored object to the object list. */
986 _dl_add_to_namespace_list (l, nsid);
988 return l;
990 #endif
992 if (mode & RTLD_NOLOAD)
994 /* We are not supposed to load the object unless it is already
995 loaded. So return now. */
996 free (realname);
997 __close (fd);
998 return NULL;
1001 /* Print debugging message. */
1002 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1003 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
1005 /* This is the ELF header. We read it in `open_verify'. */
1006 header = (void *) fbp->buf;
1008 #ifndef MAP_ANON
1009 # define MAP_ANON 0
1010 if (_dl_zerofd == -1)
1012 _dl_zerofd = _dl_sysdep_open_zero_fill ();
1013 if (_dl_zerofd == -1)
1015 free (realname);
1016 __close (fd);
1017 _dl_signal_error (errno, NULL, NULL,
1018 N_("cannot open zero fill device"));
1021 #endif
1023 /* Signal that we are going to add new objects. */
1024 if (r->r_state == RT_CONSISTENT)
1026 #ifdef SHARED
1027 /* Auditing checkpoint: we are going to add new objects. */
1028 if ((mode & __RTLD_AUDIT) == 0
1029 && __builtin_expect (GLRO(dl_naudit) > 0, 0))
1031 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
1032 /* Do not call the functions for any auditing object. */
1033 if (head->l_auditing == 0)
1035 struct audit_ifaces *afct = GLRO(dl_audit);
1036 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1038 if (afct->activity != NULL)
1039 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
1041 afct = afct->next;
1045 #endif
1047 /* Notify the debugger we have added some objects. We need to
1048 call _dl_debug_initialize in a static program in case dynamic
1049 linking has not been used before. */
1050 r->r_state = RT_ADD;
1051 _dl_debug_state ();
1052 LIBC_PROBE (map_start, 2, nsid, r);
1053 make_consistent = true;
1055 else
1056 assert (r->r_state == RT_ADD);
1058 /* Enter the new object in the list of loaded objects. */
1059 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
1060 if (__builtin_expect (l == NULL, 0))
1062 #ifdef SHARED
1063 fail_new:
1064 #endif
1065 errstring = N_("cannot create shared object descriptor");
1066 goto call_lose_errno;
1069 /* Extract the remaining details we need from the ELF header
1070 and then read in the program header table. */
1071 l->l_entry = header->e_entry;
1072 type = header->e_type;
1073 l->l_phnum = header->e_phnum;
1075 maplength = header->e_phnum * sizeof (ElfW(Phdr));
1076 if (header->e_phoff + maplength <= (size_t) fbp->len)
1077 phdr = (void *) (fbp->buf + header->e_phoff);
1078 else
1080 phdr = alloca (maplength);
1081 __lseek (fd, header->e_phoff, SEEK_SET);
1082 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1084 errstring = N_("cannot read file data");
1085 goto call_lose_errno;
1089 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1090 * executable. Other platforms default to a nonexecutable stack and don't
1091 * need PT_GNU_STACK to do so. */
1092 uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
1095 /* Scan the program header table, collecting its load commands. */
1096 struct loadcmd
1098 ElfW(Addr) mapstart, mapend, dataend, allocend;
1099 ElfW(Off) mapoff;
1100 int prot;
1101 } loadcmds[l->l_phnum], *c;
1102 size_t nloadcmds = 0;
1103 bool has_holes = false;
1105 /* The struct is initialized to zero so this is not necessary:
1106 l->l_ld = 0;
1107 l->l_phdr = 0;
1108 l->l_addr = 0; */
1109 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1110 switch (ph->p_type)
1112 /* These entries tell us where to find things once the file's
1113 segments are mapped in. We record the addresses it says
1114 verbatim, and later correct for the run-time load address. */
1115 case PT_DYNAMIC:
1116 l->l_ld = (void *) ph->p_vaddr;
1117 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1118 break;
1120 case PT_PHDR:
1121 l->l_phdr = (void *) ph->p_vaddr;
1122 break;
1124 case PT_LOAD:
1125 /* A load command tells us to map in part of the file.
1126 We record the load commands and process them all later. */
1127 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
1130 errstring = N_("ELF load command alignment not page-aligned");
1131 goto call_lose;
1133 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
1134 & (ph->p_align - 1)) != 0, 0))
1136 errstring
1137 = N_("ELF load command address/offset not properly aligned");
1138 goto call_lose;
1141 c = &loadcmds[nloadcmds++];
1142 c->mapstart = ph->p_vaddr & ~(GLRO(dl_pagesize) - 1);
1143 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
1144 & ~(GLRO(dl_pagesize) - 1));
1145 c->dataend = ph->p_vaddr + ph->p_filesz;
1146 c->allocend = ph->p_vaddr + ph->p_memsz;
1147 c->mapoff = ph->p_offset & ~(GLRO(dl_pagesize) - 1);
1149 /* Determine whether there is a gap between the last segment
1150 and this one. */
1151 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1152 has_holes = true;
1154 /* Optimize a common case. */
1155 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1156 c->prot = (PF_TO_PROT
1157 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1158 #else
1159 c->prot = 0;
1160 if (ph->p_flags & PF_R)
1161 c->prot |= PROT_READ;
1162 if (ph->p_flags & PF_W)
1163 c->prot |= PROT_WRITE;
1164 if (ph->p_flags & PF_X)
1165 c->prot |= PROT_EXEC;
1166 #endif
1167 break;
1169 case PT_TLS:
1170 if (ph->p_memsz == 0)
1171 /* Nothing to do for an empty segment. */
1172 break;
1174 l->l_tls_blocksize = ph->p_memsz;
1175 l->l_tls_align = ph->p_align;
1176 if (ph->p_align == 0)
1177 l->l_tls_firstbyte_offset = 0;
1178 else
1179 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1180 l->l_tls_initimage_size = ph->p_filesz;
1181 /* Since we don't know the load address yet only store the
1182 offset. We will adjust it later. */
1183 l->l_tls_initimage = (void *) ph->p_vaddr;
1185 /* If not loading the initial set of shared libraries,
1186 check whether we should permit loading a TLS segment. */
1187 if (__builtin_expect (l->l_type == lt_library, 1)
1188 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1189 not set up TLS data structures, so don't use them now. */
1190 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1192 /* Assign the next available module ID. */
1193 l->l_tls_modid = _dl_next_tls_modid ();
1194 break;
1197 #ifdef SHARED
1198 if (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0)
1199 /* We are loading the executable itself when the dynamic linker
1200 was executed directly. The setup will happen later. */
1201 break;
1203 # ifdef _LIBC_REENTRANT
1204 /* In a static binary there is no way to tell if we dynamically
1205 loaded libpthread. */
1206 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1207 # endif
1208 #endif
1210 /* We have not yet loaded libpthread.
1211 We can do the TLS setup right now! */
1213 void *tcb;
1215 /* The first call allocates TLS bookkeeping data structures.
1216 Then we allocate the TCB for the initial thread. */
1217 if (__builtin_expect (_dl_tls_setup (), 0)
1218 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1221 errval = ENOMEM;
1222 errstring = N_("\
1223 cannot allocate TLS data structures for initial thread");
1224 goto call_lose;
1227 /* Now we install the TCB in the thread register. */
1228 errstring = TLS_INIT_TP (tcb, 0);
1229 if (__builtin_expect (errstring == NULL, 1))
1231 /* Now we are all good. */
1232 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1233 break;
1236 /* The kernel is too old or somesuch. */
1237 errval = 0;
1238 _dl_deallocate_tls (tcb, 1);
1239 goto call_lose;
1242 /* Uh-oh, the binary expects TLS support but we cannot
1243 provide it. */
1244 errval = 0;
1245 errstring = N_("cannot handle TLS data");
1246 goto call_lose;
1247 break;
1249 case PT_GNU_STACK:
1250 stack_flags = ph->p_flags;
1251 break;
1253 case PT_GNU_RELRO:
1254 l->l_relro_addr = ph->p_vaddr;
1255 l->l_relro_size = ph->p_memsz;
1256 break;
1259 if (__builtin_expect (nloadcmds == 0, 0))
1261 /* This only happens for a bogus object that will be caught with
1262 another error below. But we don't want to go through the
1263 calculations below using NLOADCMDS - 1. */
1264 errstring = N_("object file has no loadable segments");
1265 goto call_lose;
1268 /* Now process the load commands and map segments into memory. */
1269 c = loadcmds;
1271 /* Length of the sections to be loaded. */
1272 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1274 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1276 /* This is a position-independent shared object. We can let the
1277 kernel map it anywhere it likes, but we must have space for all
1278 the segments in their specified positions relative to the first.
1279 So we map the first segment without MAP_FIXED, but with its
1280 extent increased to cover all the segments. Then we remove
1281 access from excess portion, and there is known sufficient space
1282 there to remap from the later segments.
1284 As a refinement, sometimes we have an address that we would
1285 prefer to map such objects at; but this is only a preference,
1286 the OS can do whatever it likes. */
1287 ElfW(Addr) mappref;
1288 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1289 c->mapstart & GLRO(dl_use_load_bias))
1290 - MAP_BASE_ADDR (l));
1292 /* Remember which part of the address space this object uses. */
1293 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1294 c->prot,
1295 MAP_COPY|MAP_FILE,
1296 fd, c->mapoff);
1297 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1299 map_error:
1300 errstring = N_("failed to map segment from shared object");
1301 goto call_lose_errno;
1304 l->l_map_end = l->l_map_start + maplength;
1305 l->l_addr = l->l_map_start - c->mapstart;
1307 if (has_holes)
1308 /* Change protection on the excess portion to disallow all access;
1309 the portions we do not remap later will be inaccessible as if
1310 unallocated. Then jump into the normal segment-mapping loop to
1311 handle the portion of the segment past the end of the file
1312 mapping. */
1313 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1314 loadcmds[nloadcmds - 1].mapstart - c->mapend,
1315 PROT_NONE);
1317 l->l_contiguous = 1;
1319 goto postmap;
1322 /* This object is loaded at a fixed address. This must never
1323 happen for objects loaded with dlopen(). */
1324 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1326 errstring = N_("cannot dynamically load executable");
1327 goto call_lose;
1330 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1331 fixed. */
1332 ELF_FIXED_ADDRESS (loader, c->mapstart);
1335 /* Remember which part of the address space this object uses. */
1336 l->l_map_start = c->mapstart + l->l_addr;
1337 l->l_map_end = l->l_map_start + maplength;
1338 l->l_contiguous = !has_holes;
1340 while (c < &loadcmds[nloadcmds])
1342 if (c->mapend > c->mapstart
1343 /* Map the segment contents from the file. */
1344 && (__mmap ((void *) (l->l_addr + c->mapstart),
1345 c->mapend - c->mapstart, c->prot,
1346 MAP_FIXED|MAP_COPY|MAP_FILE,
1347 fd, c->mapoff)
1348 == MAP_FAILED))
1349 goto map_error;
1351 postmap:
1352 if (c->prot & PROT_EXEC)
1353 l->l_text_end = l->l_addr + c->mapend;
1355 if (l->l_phdr == 0
1356 && c->mapoff <= header->e_phoff
1357 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1358 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1359 /* Found the program header in this segment. */
1360 l->l_phdr = (void *) (uintptr_t) (c->mapstart + header->e_phoff
1361 - c->mapoff);
1363 if (c->allocend > c->dataend)
1365 /* Extra zero pages should appear at the end of this segment,
1366 after the data mapped from the file. */
1367 ElfW(Addr) zero, zeroend, zeropage;
1369 zero = l->l_addr + c->dataend;
1370 zeroend = l->l_addr + c->allocend;
1371 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1372 & ~(GLRO(dl_pagesize) - 1));
1374 if (zeroend < zeropage)
1375 /* All the extra data is in the last page of the segment.
1376 We can just zero it. */
1377 zeropage = zeroend;
1379 if (zeropage > zero)
1381 /* Zero the final part of the last page of the segment. */
1382 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1384 /* Dag nab it. */
1385 if (__mprotect ((caddr_t) (zero
1386 & ~(GLRO(dl_pagesize) - 1)),
1387 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1389 errstring = N_("cannot change memory protections");
1390 goto call_lose_errno;
1393 memset ((void *) zero, '\0', zeropage - zero);
1394 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1395 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1396 GLRO(dl_pagesize), c->prot);
1399 if (zeroend > zeropage)
1401 /* Map the remaining zero pages in from the zero fill FD. */
1402 caddr_t mapat;
1403 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1404 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1405 -1, 0);
1406 if (__builtin_expect (mapat == MAP_FAILED, 0))
1408 errstring = N_("cannot map zero-fill pages");
1409 goto call_lose_errno;
1414 ++c;
1418 if (l->l_ld == 0)
1420 if (__builtin_expect (type == ET_DYN, 0))
1422 errstring = N_("object file has no dynamic section");
1423 goto call_lose;
1426 else
1427 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1429 elf_get_dynamic_info (l, NULL);
1431 /* Make sure we are not dlopen'ing an object that has the
1432 DF_1_NOOPEN flag set. */
1433 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1434 && (mode & __RTLD_DLOPEN))
1436 /* We are not supposed to load this object. Free all resources. */
1437 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1439 if (!l->l_libname->dont_free)
1440 free (l->l_libname);
1442 if (l->l_phdr_allocated)
1443 free ((void *) l->l_phdr);
1445 errstring = N_("shared object cannot be dlopen()ed");
1446 goto call_lose;
1449 if (l->l_phdr == NULL)
1451 /* The program header is not contained in any of the segments.
1452 We have to allocate memory ourself and copy it over from out
1453 temporary place. */
1454 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1455 * sizeof (ElfW(Phdr)));
1456 if (newp == NULL)
1458 errstring = N_("cannot allocate memory for program header");
1459 goto call_lose_errno;
1462 l->l_phdr = memcpy (newp, phdr,
1463 (header->e_phnum * sizeof (ElfW(Phdr))));
1464 l->l_phdr_allocated = 1;
1466 else
1467 /* Adjust the PT_PHDR value by the runtime load address. */
1468 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1470 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1472 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso),
1473 0) != 0)
1475 errstring = N_("invalid caller");
1476 goto call_lose;
1479 /* The stack is presently not executable, but this module
1480 requires that it be executable. We must change the
1481 protection of the variable which contains the flags used in
1482 the mprotect calls. */
1483 #ifdef SHARED
1484 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1486 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1487 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1489 struct link_map *const m = &GL(dl_rtld_map);
1490 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1491 + m->l_relro_size)
1492 & -GLRO(dl_pagesize));
1493 if (__builtin_expect (p + s <= relro_end, 1))
1495 /* The variable lies in the region protected by RELRO. */
1496 __mprotect ((void *) p, s, PROT_READ|PROT_WRITE);
1497 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1498 __mprotect ((void *) p, s, PROT_READ);
1500 else
1501 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1503 else
1504 #endif
1505 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1507 #ifdef check_consistency
1508 check_consistency ();
1509 #endif
1511 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1512 if (errval)
1514 errstring = N_("\
1515 cannot enable executable stack as shared object requires");
1516 goto call_lose;
1520 /* Adjust the address of the TLS initialization image. */
1521 if (l->l_tls_initimage != NULL)
1522 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1524 /* We are done mapping in the file. We no longer need the descriptor. */
1525 if (__builtin_expect (__close (fd) != 0, 0))
1527 errstring = N_("cannot close file descriptor");
1528 goto call_lose_errno;
1530 /* Signal that we closed the file. */
1531 fd = -1;
1533 if (l->l_type == lt_library && type == ET_EXEC)
1534 l->l_type = lt_executable;
1536 l->l_entry += l->l_addr;
1538 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1539 _dl_debug_printf ("\
1540 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1541 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1542 (int) sizeof (void *) * 2,
1543 (unsigned long int) l->l_ld,
1544 (int) sizeof (void *) * 2,
1545 (unsigned long int) l->l_addr,
1546 (int) sizeof (void *) * 2, maplength,
1547 (int) sizeof (void *) * 2,
1548 (unsigned long int) l->l_entry,
1549 (int) sizeof (void *) * 2,
1550 (unsigned long int) l->l_phdr,
1551 (int) sizeof (void *) * 2, l->l_phnum);
1553 /* Set up the symbol hash table. */
1554 _dl_setup_hash (l);
1556 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1557 have to do this for the main map. */
1558 if ((mode & RTLD_DEEPBIND) == 0
1559 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1560 && &l->l_searchlist != l->l_scope[0])
1562 /* Create an appropriate searchlist. It contains only this map.
1563 This is the definition of DT_SYMBOLIC in SysVr4. */
1564 l->l_symbolic_searchlist.r_list[0] = l;
1565 l->l_symbolic_searchlist.r_nlist = 1;
1567 /* Now move the existing entries one back. */
1568 memmove (&l->l_scope[1], &l->l_scope[0],
1569 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1571 /* Now add the new entry. */
1572 l->l_scope[0] = &l->l_symbolic_searchlist;
1575 /* Remember whether this object must be initialized first. */
1576 if (l->l_flags_1 & DF_1_INITFIRST)
1577 GL(dl_initfirst) = l;
1579 /* Finally the file information. */
1580 l->l_dev = st.st_dev;
1581 l->l_ino = st.st_ino;
1583 /* When we profile the SONAME might be needed for something else but
1584 loading. Add it right away. */
1585 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1586 && l->l_info[DT_SONAME] != NULL)
1587 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1588 + l->l_info[DT_SONAME]->d_un.d_val));
1590 #ifdef DL_AFTER_LOAD
1591 DL_AFTER_LOAD (l);
1592 #endif
1594 /* Now that the object is fully initialized add it to the object list. */
1595 _dl_add_to_namespace_list (l, nsid);
1597 #ifdef SHARED
1598 /* Auditing checkpoint: we have a new object. */
1599 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
1600 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1602 struct audit_ifaces *afct = GLRO(dl_audit);
1603 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1605 if (afct->objopen != NULL)
1607 l->l_audit[cnt].bindflags
1608 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1610 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1613 afct = afct->next;
1616 #endif
1618 return l;
1621 /* Print search path. */
1622 static void
1623 print_search_path (struct r_search_path_elem **list,
1624 const char *what, const char *name)
1626 char buf[max_dirnamelen + max_capstrlen];
1627 int first = 1;
1629 _dl_debug_printf (" search path=");
1631 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1633 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1634 size_t cnt;
1636 for (cnt = 0; cnt < ncapstr; ++cnt)
1637 if ((*list)->status[cnt] != nonexisting)
1639 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1640 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1641 cp[0] = '\0';
1642 else
1643 cp[-1] = '\0';
1645 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1646 first = 0;
1649 ++list;
1652 if (name != NULL)
1653 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1654 name[0] ? name : rtld_progname);
1655 else
1656 _dl_debug_printf_c ("\t\t(%s)\n", what);
1659 /* Open a file and verify it is an ELF file for this architecture. We
1660 ignore only ELF files for other architectures. Non-ELF files and
1661 ELF files with different header information cause fatal errors since
1662 this could mean there is something wrong in the installation and the
1663 user might want to know about this. */
1664 static int
1665 open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
1666 int whatcode, bool *found_other_class, bool free_name)
1668 /* This is the expected ELF header. */
1669 #define ELF32_CLASS ELFCLASS32
1670 #define ELF64_CLASS ELFCLASS64
1671 #ifndef VALID_ELF_HEADER
1672 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1673 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1674 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1675 #elif defined MORE_ELF_HEADER_DATA
1676 MORE_ELF_HEADER_DATA;
1677 #endif
1678 static const unsigned char expected[EI_NIDENT] =
1680 [EI_MAG0] = ELFMAG0,
1681 [EI_MAG1] = ELFMAG1,
1682 [EI_MAG2] = ELFMAG2,
1683 [EI_MAG3] = ELFMAG3,
1684 [EI_CLASS] = ELFW(CLASS),
1685 [EI_DATA] = byteorder,
1686 [EI_VERSION] = EV_CURRENT,
1687 [EI_OSABI] = ELFOSABI_SYSV,
1688 [EI_ABIVERSION] = 0
1690 static const struct
1692 ElfW(Word) vendorlen;
1693 ElfW(Word) datalen;
1694 ElfW(Word) type;
1695 char vendor[4];
1696 } expected_note = { 4, 16, 1, "GNU" };
1697 /* Initialize it to make the compiler happy. */
1698 const char *errstring = NULL;
1699 int errval = 0;
1701 #ifdef SHARED
1702 /* Give the auditing libraries a chance. */
1703 if (__builtin_expect (GLRO(dl_naudit) > 0, 0) && whatcode != 0
1704 && loader->l_auditing == 0)
1706 struct audit_ifaces *afct = GLRO(dl_audit);
1707 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1709 if (afct->objsearch != NULL)
1711 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1712 whatcode);
1713 if (name == NULL)
1714 /* Ignore the path. */
1715 return -1;
1718 afct = afct->next;
1721 #endif
1723 /* Open the file. We always open files read-only. */
1724 int fd = __open (name, O_RDONLY | O_CLOEXEC);
1725 if (fd != -1)
1727 ElfW(Ehdr) *ehdr;
1728 ElfW(Phdr) *phdr, *ph;
1729 ElfW(Word) *abi_note;
1730 unsigned int osversion;
1731 size_t maplength;
1733 /* We successfully openened the file. Now verify it is a file
1734 we can use. */
1735 __set_errno (0);
1736 fbp->len = 0;
1737 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1738 /* Read in the header. */
1741 ssize_t retlen = __libc_read (fd, fbp->buf + fbp->len,
1742 sizeof (fbp->buf) - fbp->len);
1743 if (retlen <= 0)
1744 break;
1745 fbp->len += retlen;
1747 while (__builtin_expect (fbp->len < sizeof (ElfW(Ehdr)), 0));
1749 /* This is where the ELF header is loaded. */
1750 ehdr = (ElfW(Ehdr) *) fbp->buf;
1752 /* Now run the tests. */
1753 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1755 errval = errno;
1756 errstring = (errval == 0
1757 ? N_("file too short") : N_("cannot read file data"));
1758 call_lose:
1759 if (free_name)
1761 char *realname = (char *) name;
1762 name = strdupa (realname);
1763 free (realname);
1765 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1768 /* See whether the ELF header is what we expect. */
1769 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1770 EI_ABIVERSION)
1771 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1772 ehdr->e_ident[EI_ABIVERSION])
1773 || memcmp (&ehdr->e_ident[EI_PAD],
1774 &expected[EI_PAD],
1775 EI_NIDENT - EI_PAD) != 0,
1778 /* Something is wrong. */
1779 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1780 if (*magp !=
1781 #if BYTE_ORDER == LITTLE_ENDIAN
1782 ((ELFMAG0 << (EI_MAG0 * 8)) |
1783 (ELFMAG1 << (EI_MAG1 * 8)) |
1784 (ELFMAG2 << (EI_MAG2 * 8)) |
1785 (ELFMAG3 << (EI_MAG3 * 8)))
1786 #else
1787 ((ELFMAG0 << (EI_MAG3 * 8)) |
1788 (ELFMAG1 << (EI_MAG2 * 8)) |
1789 (ELFMAG2 << (EI_MAG1 * 8)) |
1790 (ELFMAG3 << (EI_MAG0 * 8)))
1791 #endif
1793 errstring = N_("invalid ELF header");
1794 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1796 /* This is not a fatal error. On architectures where
1797 32-bit and 64-bit binaries can be run this might
1798 happen. */
1799 *found_other_class = true;
1800 goto close_and_out;
1802 else if (ehdr->e_ident[EI_DATA] != byteorder)
1804 if (BYTE_ORDER == BIG_ENDIAN)
1805 errstring = N_("ELF file data encoding not big-endian");
1806 else
1807 errstring = N_("ELF file data encoding not little-endian");
1809 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1810 errstring
1811 = N_("ELF file version ident does not match current one");
1812 /* XXX We should be able so set system specific versions which are
1813 allowed here. */
1814 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1815 errstring = N_("ELF file OS ABI invalid");
1816 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1817 ehdr->e_ident[EI_ABIVERSION]))
1818 errstring = N_("ELF file ABI version invalid");
1819 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1820 EI_NIDENT - EI_PAD) != 0)
1821 errstring = N_("nonzero padding in e_ident");
1822 else
1823 /* Otherwise we don't know what went wrong. */
1824 errstring = N_("internal error");
1826 goto call_lose;
1829 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1831 errstring = N_("ELF file version does not match current one");
1832 goto call_lose;
1834 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1835 goto close_and_out;
1836 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1837 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1839 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1840 goto call_lose;
1842 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1843 != sizeof (ElfW(Phdr)))
1845 errstring = N_("ELF file's phentsize not the expected size");
1846 goto call_lose;
1849 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1850 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1851 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1852 else
1854 phdr = alloca (maplength);
1855 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1856 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1858 read_error:
1859 errval = errno;
1860 errstring = N_("cannot read file data");
1861 goto call_lose;
1865 /* Check .note.ABI-tag if present. */
1866 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1867 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1869 ElfW(Addr) size = ph->p_filesz;
1871 if (ph->p_offset + size <= (size_t) fbp->len)
1872 abi_note = (void *) (fbp->buf + ph->p_offset);
1873 else
1875 abi_note = alloca (size);
1876 __lseek (fd, ph->p_offset, SEEK_SET);
1877 if (__libc_read (fd, (void *) abi_note, size) != size)
1878 goto read_error;
1881 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1883 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1884 ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
1885 + ROUND (abi_note[0])
1886 + ROUND (abi_note[1]);
1888 if (size - 32 < note_size)
1890 size = 0;
1891 break;
1893 size -= note_size;
1894 abi_note = (void *) abi_note + note_size;
1897 if (size == 0)
1898 continue;
1900 osversion = (abi_note[5] & 0xff) * 65536
1901 + (abi_note[6] & 0xff) * 256
1902 + (abi_note[7] & 0xff);
1903 if (abi_note[4] != __ABI_TAG_OS
1904 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1906 close_and_out:
1907 __close (fd);
1908 __set_errno (ENOENT);
1909 fd = -1;
1912 break;
1916 return fd;
1919 /* Try to open NAME in one of the directories in *DIRSP.
1920 Return the fd, or -1. If successful, fill in *REALNAME
1921 with the malloc'd full directory name. If it turns out
1922 that none of the directories in *DIRSP exists, *DIRSP is
1923 replaced with (void *) -1, and the old value is free()d
1924 if MAY_FREE_DIRS is true. */
1926 static int
1927 open_path (const char *name, size_t namelen, int secure,
1928 struct r_search_path_struct *sps, char **realname,
1929 struct filebuf *fbp, struct link_map *loader, int whatcode,
1930 bool *found_other_class)
1932 struct r_search_path_elem **dirs = sps->dirs;
1933 char *buf;
1934 int fd = -1;
1935 const char *current_what = NULL;
1936 int any = 0;
1938 if (__builtin_expect (dirs == NULL, 0))
1939 /* We're called before _dl_init_paths when loading the main executable
1940 given on the command line when rtld is run directly. */
1941 return -1;
1943 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1946 struct r_search_path_elem *this_dir = *dirs;
1947 size_t buflen = 0;
1948 size_t cnt;
1949 char *edp;
1950 int here_any = 0;
1951 int err;
1953 /* If we are debugging the search for libraries print the path
1954 now if it hasn't happened now. */
1955 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1956 && current_what != this_dir->what)
1958 current_what = this_dir->what;
1959 print_search_path (dirs, current_what, this_dir->where);
1962 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1963 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1965 /* Skip this directory if we know it does not exist. */
1966 if (this_dir->status[cnt] == nonexisting)
1967 continue;
1969 buflen =
1970 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1971 capstr[cnt].len),
1972 name, namelen)
1973 - buf);
1975 /* Print name we try if this is wanted. */
1976 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1977 _dl_debug_printf (" trying file=%s\n", buf);
1979 fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
1980 false);
1981 if (this_dir->status[cnt] == unknown)
1983 if (fd != -1)
1984 this_dir->status[cnt] = existing;
1985 /* Do not update the directory information when loading
1986 auditing code. We must try to disturb the program as
1987 little as possible. */
1988 else if (loader == NULL
1989 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1991 /* We failed to open machine dependent library. Let's
1992 test whether there is any directory at all. */
1993 struct stat64 st;
1995 buf[buflen - namelen - 1] = '\0';
1997 if (__xstat64 (_STAT_VER, buf, &st) != 0
1998 || ! S_ISDIR (st.st_mode))
1999 /* The directory does not exist or it is no directory. */
2000 this_dir->status[cnt] = nonexisting;
2001 else
2002 this_dir->status[cnt] = existing;
2006 /* Remember whether we found any existing directory. */
2007 here_any |= this_dir->status[cnt] != nonexisting;
2009 if (fd != -1 && __builtin_expect (secure, 0)
2010 && INTUSE(__libc_enable_secure))
2012 /* This is an extra security effort to make sure nobody can
2013 preload broken shared objects which are in the trusted
2014 directories and so exploit the bugs. */
2015 struct stat64 st;
2017 if (__fxstat64 (_STAT_VER, fd, &st) != 0
2018 || (st.st_mode & S_ISUID) == 0)
2020 /* The shared object cannot be tested for being SUID
2021 or this bit is not set. In this case we must not
2022 use this object. */
2023 __close (fd);
2024 fd = -1;
2025 /* We simply ignore the file, signal this by setting
2026 the error value which would have been set by `open'. */
2027 errno = ENOENT;
2032 if (fd != -1)
2034 *realname = (char *) malloc (buflen);
2035 if (*realname != NULL)
2037 memcpy (*realname, buf, buflen);
2038 return fd;
2040 else
2042 /* No memory for the name, we certainly won't be able
2043 to load and link it. */
2044 __close (fd);
2045 return -1;
2048 if (here_any && (err = errno) != ENOENT && err != EACCES)
2049 /* The file exists and is readable, but something went wrong. */
2050 return -1;
2052 /* Remember whether we found anything. */
2053 any |= here_any;
2055 while (*++dirs != NULL);
2057 /* Remove the whole path if none of the directories exists. */
2058 if (__builtin_expect (! any, 0))
2060 /* Paths which were allocated using the minimal malloc() in ld.so
2061 must not be freed using the general free() in libc. */
2062 if (sps->malloced)
2063 free (sps->dirs);
2065 /* rtld_search_dirs is attribute_relro, therefore avoid writing
2066 into it. */
2067 if (sps != &rtld_search_dirs)
2068 sps->dirs = (void *) -1;
2071 return -1;
2074 /* Map in the shared object file NAME. */
2076 struct link_map *
2077 internal_function
2078 _dl_map_object (struct link_map *loader, const char *name,
2079 int type, int trace_mode, int mode, Lmid_t nsid)
2081 int fd;
2082 char *realname;
2083 char *name_copy;
2084 struct link_map *l;
2085 struct filebuf fb;
2087 assert (nsid >= 0);
2088 assert (nsid < GL(dl_nns));
2090 /* Look for this name among those already loaded. */
2091 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
2093 /* If the requested name matches the soname of a loaded object,
2094 use that object. Elide this check for names that have not
2095 yet been opened. */
2096 if (__builtin_expect (l->l_faked, 0) != 0
2097 || __builtin_expect (l->l_removed, 0) != 0)
2098 continue;
2099 if (!_dl_name_match_p (name, l))
2101 const char *soname;
2103 if (__builtin_expect (l->l_soname_added, 1)
2104 || l->l_info[DT_SONAME] == NULL)
2105 continue;
2107 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
2108 + l->l_info[DT_SONAME]->d_un.d_val);
2109 if (strcmp (name, soname) != 0)
2110 continue;
2112 /* We have a match on a new name -- cache it. */
2113 add_name_to_object (l, soname);
2114 l->l_soname_added = 1;
2117 /* We have a match. */
2118 return l;
2121 /* Display information if we are debugging. */
2122 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
2123 && loader != NULL)
2124 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
2125 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
2126 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
2127 name, nsid, loader->l_name[0]
2128 ? loader->l_name : rtld_progname, loader->l_ns);
2130 #ifdef SHARED
2131 /* Give the auditing libraries a chance to change the name before we
2132 try anything. */
2133 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
2134 && (loader == NULL || loader->l_auditing == 0))
2136 struct audit_ifaces *afct = GLRO(dl_audit);
2137 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2139 if (afct->objsearch != NULL)
2141 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
2142 LA_SER_ORIG);
2143 if (name == NULL)
2145 /* Do not try anything further. */
2146 fd = -1;
2147 goto no_file;
2151 afct = afct->next;
2154 #endif
2156 /* Will be true if we found a DSO which is of the other ELF class. */
2157 bool found_other_class = false;
2159 if (strchr (name, '/') == NULL)
2161 /* Search for NAME in several places. */
2163 size_t namelen = strlen (name) + 1;
2165 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2166 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2168 fd = -1;
2170 /* When the object has the RUNPATH information we don't use any
2171 RPATHs. */
2172 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2174 /* This is the executable's map (if there is one). Make sure that
2175 we do not look at it twice. */
2176 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2177 bool did_main_map = false;
2179 /* First try the DT_RPATH of the dependent object that caused NAME
2180 to be loaded. Then that object's dependent, and on up. */
2181 for (l = loader; l; l = l->l_loader)
2182 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2184 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2185 &l->l_rpath_dirs,
2186 &realname, &fb, loader, LA_SER_RUNPATH,
2187 &found_other_class);
2188 if (fd != -1)
2189 break;
2191 did_main_map |= l == main_map;
2194 /* If dynamically linked, try the DT_RPATH of the executable
2195 itself. NB: we do this for lookups in any namespace. */
2196 if (fd == -1 && !did_main_map
2197 && main_map != NULL && main_map->l_type != lt_loaded
2198 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2199 "RPATH"))
2200 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2201 &main_map->l_rpath_dirs,
2202 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2203 &found_other_class);
2206 /* Try the LD_LIBRARY_PATH environment variable. */
2207 if (fd == -1 && env_path_list.dirs != (void *) -1)
2208 fd = open_path (name, namelen, mode & __RTLD_SECURE, &env_path_list,
2209 &realname, &fb,
2210 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2211 LA_SER_LIBPATH, &found_other_class);
2213 /* Look at the RUNPATH information for this binary. */
2214 if (fd == -1 && loader != NULL
2215 && cache_rpath (loader, &loader->l_runpath_dirs,
2216 DT_RUNPATH, "RUNPATH"))
2217 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2218 &loader->l_runpath_dirs, &realname, &fb, loader,
2219 LA_SER_RUNPATH, &found_other_class);
2221 #ifdef USE_LDCONFIG
2222 if (fd == -1
2223 && (__builtin_expect (! (mode & __RTLD_SECURE), 1)
2224 || ! INTUSE(__libc_enable_secure))
2225 && __builtin_expect (GLRO(dl_inhibit_cache) == 0, 1))
2227 /* Check the list of libraries in the file /etc/ld.so.cache,
2228 for compatibility with Linux's ldconfig program. */
2229 const char *cached = _dl_load_cache_lookup (name);
2231 if (cached != NULL)
2233 # ifdef SHARED
2234 // XXX Correct to unconditionally default to namespace 0?
2235 l = (loader
2236 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2237 ?: &GL(dl_rtld_map));
2238 # else
2239 l = loader;
2240 # endif
2242 /* If the loader has the DF_1_NODEFLIB flag set we must not
2243 use a cache entry from any of these directories. */
2244 if (
2245 # ifndef SHARED
2246 /* 'l' is always != NULL for dynamically linked objects. */
2247 l != NULL &&
2248 # endif
2249 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
2251 const char *dirp = system_dirs;
2252 unsigned int cnt = 0;
2256 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2258 /* The prefix matches. Don't use the entry. */
2259 cached = NULL;
2260 break;
2263 dirp += system_dirs_len[cnt] + 1;
2264 ++cnt;
2266 while (cnt < nsystem_dirs_len);
2269 if (cached != NULL)
2271 fd = open_verify (cached,
2272 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2273 LA_SER_CONFIG, &found_other_class, false);
2274 if (__builtin_expect (fd != -1, 1))
2276 realname = local_strdup (cached);
2277 if (realname == NULL)
2279 __close (fd);
2280 fd = -1;
2286 #endif
2288 /* Finally, try the default path. */
2289 if (fd == -1
2290 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2291 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
2292 && rtld_search_dirs.dirs != (void *) -1)
2293 fd = open_path (name, namelen, mode & __RTLD_SECURE, &rtld_search_dirs,
2294 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2296 /* Add another newline when we are tracing the library loading. */
2297 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2298 _dl_debug_printf ("\n");
2300 else
2302 /* The path may contain dynamic string tokens. */
2303 realname = (loader
2304 ? expand_dynamic_string_token (loader, name, 0)
2305 : local_strdup (name));
2306 if (realname == NULL)
2307 fd = -1;
2308 else
2310 fd = open_verify (realname, &fb,
2311 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
2312 &found_other_class, true);
2313 if (__builtin_expect (fd, 0) == -1)
2314 free (realname);
2318 #ifdef SHARED
2319 no_file:
2320 #endif
2321 /* In case the LOADER information has only been provided to get to
2322 the appropriate RUNPATH/RPATH information we do not need it
2323 anymore. */
2324 if (mode & __RTLD_CALLMAP)
2325 loader = NULL;
2327 if (__builtin_expect (fd, 0) == -1)
2329 if (trace_mode
2330 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
2332 /* We haven't found an appropriate library. But since we
2333 are only interested in the list of libraries this isn't
2334 so severe. Fake an entry with all the information we
2335 have. */
2336 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2338 /* Allocate a new object map. */
2339 if ((name_copy = local_strdup (name)) == NULL
2340 || (l = _dl_new_object (name_copy, name, type, loader,
2341 mode, nsid)) == NULL)
2343 free (name_copy);
2344 _dl_signal_error (ENOMEM, name, NULL,
2345 N_("cannot create shared object descriptor"));
2347 /* Signal that this is a faked entry. */
2348 l->l_faked = 1;
2349 /* Since the descriptor is initialized with zero we do not
2350 have do this here.
2351 l->l_reserved = 0; */
2352 l->l_buckets = &dummy_bucket;
2353 l->l_nbuckets = 1;
2354 l->l_relocated = 1;
2356 /* Enter the object in the object list. */
2357 _dl_add_to_namespace_list (l, nsid);
2359 return l;
2361 else if (found_other_class)
2362 _dl_signal_error (0, name, NULL,
2363 ELFW(CLASS) == ELFCLASS32
2364 ? N_("wrong ELF class: ELFCLASS64")
2365 : N_("wrong ELF class: ELFCLASS32"));
2366 else
2367 _dl_signal_error (errno, name, NULL,
2368 N_("cannot open shared object file"));
2371 void *stack_end = __libc_stack_end;
2372 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
2373 &stack_end, nsid);
2377 void
2378 internal_function
2379 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2381 if (counting)
2383 si->dls_cnt = 0;
2384 si->dls_size = 0;
2387 unsigned int idx = 0;
2388 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2389 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2390 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2392 if (sps->dirs != (void *) -1)
2394 struct r_search_path_elem **dirs = sps->dirs;
2397 const struct r_search_path_elem *const r = *dirs++;
2398 if (counting)
2400 si->dls_cnt++;
2401 si->dls_size += MAX (2, r->dirnamelen);
2403 else
2405 Dl_serpath *const sp = &si->dls_serpath[idx++];
2406 sp->dls_name = allocptr;
2407 if (r->dirnamelen < 2)
2408 *allocptr++ = r->dirnamelen ? '/' : '.';
2409 else
2410 allocptr = __mempcpy (allocptr,
2411 r->dirname, r->dirnamelen - 1);
2412 *allocptr++ = '\0';
2413 sp->dls_flags = flags;
2416 while (*dirs != NULL);
2420 /* When the object has the RUNPATH information we don't use any RPATHs. */
2421 if (loader->l_info[DT_RUNPATH] == NULL)
2423 /* First try the DT_RPATH of the dependent object that caused NAME
2424 to be loaded. Then that object's dependent, and on up. */
2426 struct link_map *l = loader;
2429 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2430 add_path (&l->l_rpath_dirs, XXX_RPATH);
2431 l = l->l_loader;
2433 while (l != NULL);
2435 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2436 if (loader->l_ns == LM_ID_BASE)
2438 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2439 if (l != NULL && l->l_type != lt_loaded && l != loader)
2440 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2441 add_path (&l->l_rpath_dirs, XXX_RPATH);
2445 /* Try the LD_LIBRARY_PATH environment variable. */
2446 add_path (&env_path_list, XXX_ENV);
2448 /* Look at the RUNPATH information for this binary. */
2449 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2450 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2452 /* XXX
2453 Here is where ld.so.cache gets checked, but we don't have
2454 a way to indicate that in the results for Dl_serinfo. */
2456 /* Finally, try the default path. */
2457 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2458 add_path (&rtld_search_dirs, XXX_default);
2460 if (counting)
2461 /* Count the struct size before the string area, which we didn't
2462 know before we completed dls_cnt. */
2463 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;