Add x86 init-arch to nptl
[glibc.git] / elf / dl-load.c
blob655e38ee4b0d4e1dfe9bedcf2bb1d682f6ddd276
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 == '$', 0))
338 const char *repl = NULL;
339 size_t len;
341 ++name;
342 if ((len = is_dst (start, name, "ORIGIN", is_path,
343 INTUSE(__libc_enable_secure))) != 0)
345 repl = l->l_origin;
346 check_for_trusted = (INTUSE(__libc_enable_secure)
347 && l->l_type == lt_executable);
349 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
350 repl = GLRO(dl_platform);
351 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
352 repl = DL_DST_LIB;
354 if (repl != NULL && repl != (const char *) -1)
356 wp = __stpcpy (wp, repl);
357 name += len;
359 else if (len > 1)
361 /* We cannot use this path element, the value of the
362 replacement is unknown. */
363 wp = last_elem;
364 name += len;
365 while (*name != '\0' && (!is_path || *name != ':'))
366 ++name;
367 /* Also skip following colon if this is the first rpath
368 element, but keep an empty element at the end. */
369 if (wp == result && is_path && *name == ':' && name[1] != '\0')
370 ++name;
372 else
373 /* No DST we recognize. */
374 *wp++ = '$';
376 else
378 *wp++ = *name++;
379 if (is_path && *name == ':')
381 /* In SUID/SGID programs, after $ORIGIN expansion the
382 normalized path must be rooted in one of the trusted
383 directories. */
384 if (__builtin_expect (check_for_trusted, false)
385 && !is_trusted_path_normalize (last_elem, wp - last_elem))
386 wp = last_elem;
387 else
388 last_elem = wp;
390 check_for_trusted = false;
394 while (*name != '\0');
396 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
397 path must be rooted in one of the trusted directories. */
398 if (__builtin_expect (check_for_trusted, false)
399 && !is_trusted_path_normalize (last_elem, wp - last_elem))
400 wp = last_elem;
402 *wp = '\0';
404 return result;
408 /* Return copy of argument with all recognized dynamic string tokens
409 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
410 might not be possible to determine the path from which the object
411 belonging to the map is loaded. In this case the path element
412 containing $ORIGIN is left out. */
413 static char *
414 expand_dynamic_string_token (struct link_map *l, const char *s, int is_path)
416 /* We make two runs over the string. First we determine how large the
417 resulting string is and then we copy it over. Since this is no
418 frequently executed operation we are looking here not for performance
419 but rather for code size. */
420 size_t cnt;
421 size_t total;
422 char *result;
424 /* Determine the number of DST elements. */
425 cnt = DL_DST_COUNT (s, is_path);
427 /* If we do not have to replace anything simply copy the string. */
428 if (__builtin_expect (cnt, 0) == 0)
429 return local_strdup (s);
431 /* Determine the length of the substituted string. */
432 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
434 /* Allocate the necessary memory. */
435 result = (char *) malloc (total + 1);
436 if (result == NULL)
437 return NULL;
439 return _dl_dst_substitute (l, s, result, is_path);
443 /* Add `name' to the list of names for a particular shared object.
444 `name' is expected to have been allocated with malloc and will
445 be freed if the shared object already has this name.
446 Returns false if the object already had this name. */
447 static void
448 internal_function
449 add_name_to_object (struct link_map *l, const char *name)
451 struct libname_list *lnp, *lastp;
452 struct libname_list *newname;
453 size_t name_len;
455 lastp = NULL;
456 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
457 if (strcmp (name, lnp->name) == 0)
458 return;
460 name_len = strlen (name) + 1;
461 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
462 if (newname == NULL)
464 /* No more memory. */
465 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
466 return;
468 /* The object should have a libname set from _dl_new_object. */
469 assert (lastp != NULL);
471 newname->name = memcpy (newname + 1, name, name_len);
472 newname->next = NULL;
473 newname->dont_free = 0;
474 lastp->next = newname;
477 /* Standard search directories. */
478 static struct r_search_path_struct rtld_search_dirs attribute_relro;
480 static size_t max_dirnamelen;
482 static struct r_search_path_elem **
483 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
484 int check_trusted, const char *what, const char *where)
486 char *cp;
487 size_t nelems = 0;
489 while ((cp = __strsep (&rpath, sep)) != NULL)
491 struct r_search_path_elem *dirp;
492 size_t len = strlen (cp);
494 /* `strsep' can pass an empty string. This has to be
495 interpreted as `use the current directory'. */
496 if (len == 0)
498 static const char curwd[] = "./";
499 cp = (char *) curwd;
502 /* Remove trailing slashes (except for "/"). */
503 while (len > 1 && cp[len - 1] == '/')
504 --len;
506 /* Now add one if there is none so far. */
507 if (len > 0 && cp[len - 1] != '/')
508 cp[len++] = '/';
510 /* Make sure we don't use untrusted directories if we run SUID. */
511 if (__builtin_expect (check_trusted, 0) && !is_trusted_path (cp, len))
512 continue;
514 /* See if this directory is already known. */
515 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
516 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
517 break;
519 if (dirp != NULL)
521 /* It is available, see whether it's on our own list. */
522 size_t cnt;
523 for (cnt = 0; cnt < nelems; ++cnt)
524 if (result[cnt] == dirp)
525 break;
527 if (cnt == nelems)
528 result[nelems++] = dirp;
530 else
532 size_t cnt;
533 enum r_dir_status init_val;
534 size_t where_len = where ? strlen (where) + 1 : 0;
536 /* It's a new directory. Create an entry and add it. */
537 dirp = (struct r_search_path_elem *)
538 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
539 + where_len + len + 1);
540 if (dirp == NULL)
541 _dl_signal_error (ENOMEM, NULL, NULL,
542 N_("cannot create cache for search path"));
544 dirp->dirname = ((char *) dirp + sizeof (*dirp)
545 + ncapstr * sizeof (enum r_dir_status));
546 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
547 dirp->dirnamelen = len;
549 if (len > max_dirnamelen)
550 max_dirnamelen = len;
552 /* We have to make sure all the relative directories are
553 never ignored. The current directory might change and
554 all our saved information would be void. */
555 init_val = cp[0] != '/' ? existing : unknown;
556 for (cnt = 0; cnt < ncapstr; ++cnt)
557 dirp->status[cnt] = init_val;
559 dirp->what = what;
560 if (__builtin_expect (where != NULL, 1))
561 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
562 + (ncapstr * sizeof (enum r_dir_status)),
563 where, where_len);
564 else
565 dirp->where = NULL;
567 dirp->next = GL(dl_all_dirs);
568 GL(dl_all_dirs) = dirp;
570 /* Put it in the result array. */
571 result[nelems++] = dirp;
575 /* Terminate the array. */
576 result[nelems] = NULL;
578 return result;
582 static bool
583 internal_function
584 decompose_rpath (struct r_search_path_struct *sps,
585 const char *rpath, struct link_map *l, const char *what)
587 /* Make a copy we can work with. */
588 const char *where = l->l_name;
589 char *copy;
590 char *cp;
591 struct r_search_path_elem **result;
592 size_t nelems;
593 /* Initialize to please the compiler. */
594 const char *errstring = NULL;
596 /* First see whether we must forget the RUNPATH and RPATH from this
597 object. */
598 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
599 && !INTUSE(__libc_enable_secure))
601 const char *inhp = GLRO(dl_inhibit_rpath);
605 const char *wp = where;
607 while (*inhp == *wp && *wp != '\0')
609 ++inhp;
610 ++wp;
613 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
615 /* This object is on the list of objects for which the
616 RUNPATH and RPATH must not be used. */
617 sps->dirs = (void *) -1;
618 return false;
621 while (*inhp != '\0')
622 if (*inhp++ == ':')
623 break;
625 while (*inhp != '\0');
628 /* Make a writable copy. At the same time expand possible dynamic
629 string tokens. */
630 copy = expand_dynamic_string_token (l, rpath, 1);
631 if (copy == NULL)
633 errstring = N_("cannot create RUNPATH/RPATH copy");
634 goto signal_error;
637 /* Ignore empty rpaths. */
638 if (*copy == 0)
640 free (copy);
641 sps->dirs = (struct r_search_path_elem **) -1;
642 return false;
645 /* Count the number of necessary elements in the result array. */
646 nelems = 0;
647 for (cp = copy; *cp != '\0'; ++cp)
648 if (*cp == ':')
649 ++nelems;
651 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
652 number of necessary entries. */
653 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
654 * sizeof (*result));
655 if (result == NULL)
657 free (copy);
658 errstring = N_("cannot create cache for search path");
659 signal_error:
660 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
663 fillin_rpath (copy, result, ":", 0, what, where);
665 /* Free the copied RPATH string. `fillin_rpath' make own copies if
666 necessary. */
667 free (copy);
669 sps->dirs = result;
670 /* The caller will change this value if we haven't used a real malloc. */
671 sps->malloced = 1;
672 return true;
675 /* Make sure cached path information is stored in *SP
676 and return true if there are any paths to search there. */
677 static bool
678 cache_rpath (struct link_map *l,
679 struct r_search_path_struct *sp,
680 int tag,
681 const char *what)
683 if (sp->dirs == (void *) -1)
684 return false;
686 if (sp->dirs != NULL)
687 return true;
689 if (l->l_info[tag] == NULL)
691 /* There is no path. */
692 sp->dirs = (void *) -1;
693 return false;
696 /* Make sure the cache information is available. */
697 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
698 + l->l_info[tag]->d_un.d_val),
699 l, what);
703 void
704 internal_function
705 _dl_init_paths (const char *llp)
707 size_t idx;
708 const char *strp;
709 struct r_search_path_elem *pelem, **aelem;
710 size_t round_size;
711 #ifdef SHARED
712 struct link_map *l;
713 #endif
714 /* Initialize to please the compiler. */
715 const char *errstring = NULL;
717 /* Fill in the information about the application's RPATH and the
718 directories addressed by the LD_LIBRARY_PATH environment variable. */
720 /* Get the capabilities. */
721 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
722 &ncapstr, &max_capstrlen);
724 /* First set up the rest of the default search directory entries. */
725 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
726 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
727 if (rtld_search_dirs.dirs == NULL)
729 errstring = N_("cannot create search path array");
730 signal_error:
731 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
734 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
735 + ncapstr * sizeof (enum r_dir_status))
736 / sizeof (struct r_search_path_elem));
738 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
739 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
740 * round_size * sizeof (struct r_search_path_elem));
741 if (rtld_search_dirs.dirs[0] == NULL)
743 errstring = N_("cannot create cache for search path");
744 goto signal_error;
747 rtld_search_dirs.malloced = 0;
748 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
749 strp = system_dirs;
750 idx = 0;
754 size_t cnt;
756 *aelem++ = pelem;
758 pelem->what = "system search path";
759 pelem->where = NULL;
761 pelem->dirname = strp;
762 pelem->dirnamelen = system_dirs_len[idx];
763 strp += system_dirs_len[idx] + 1;
765 /* System paths must be absolute. */
766 assert (pelem->dirname[0] == '/');
767 for (cnt = 0; cnt < ncapstr; ++cnt)
768 pelem->status[cnt] = unknown;
770 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
772 pelem += round_size;
774 while (idx < nsystem_dirs_len);
776 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
777 *aelem = NULL;
779 #ifdef SHARED
780 /* This points to the map of the main object. */
781 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
782 if (l != NULL)
784 assert (l->l_type != lt_loaded);
786 if (l->l_info[DT_RUNPATH])
788 /* Allocate room for the search path and fill in information
789 from RUNPATH. */
790 decompose_rpath (&l->l_runpath_dirs,
791 (const void *) (D_PTR (l, l_info[DT_STRTAB])
792 + l->l_info[DT_RUNPATH]->d_un.d_val),
793 l, "RUNPATH");
794 /* During rtld init the memory is allocated by the stub malloc,
795 prevent any attempt to free it by the normal malloc. */
796 l->l_runpath_dirs.malloced = 0;
798 /* The RPATH is ignored. */
799 l->l_rpath_dirs.dirs = (void *) -1;
801 else
803 l->l_runpath_dirs.dirs = (void *) -1;
805 if (l->l_info[DT_RPATH])
807 /* Allocate room for the search path and fill in information
808 from RPATH. */
809 decompose_rpath (&l->l_rpath_dirs,
810 (const void *) (D_PTR (l, l_info[DT_STRTAB])
811 + l->l_info[DT_RPATH]->d_un.d_val),
812 l, "RPATH");
813 /* During rtld init the memory is allocated by the stub
814 malloc, prevent any attempt to free it by the normal
815 malloc. */
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 ElfW(Off) 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 && 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 *) (uintptr_t) (c->mapstart + header->e_phoff
1355 - c->mapoff);
1357 if (c->allocend > c->dataend)
1359 /* Extra zero pages should appear at the end of this segment,
1360 after the data mapped from the file. */
1361 ElfW(Addr) zero, zeroend, zeropage;
1363 zero = l->l_addr + c->dataend;
1364 zeroend = l->l_addr + c->allocend;
1365 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1366 & ~(GLRO(dl_pagesize) - 1));
1368 if (zeroend < zeropage)
1369 /* All the extra data is in the last page of the segment.
1370 We can just zero it. */
1371 zeropage = zeroend;
1373 if (zeropage > zero)
1375 /* Zero the final part of the last page of the segment. */
1376 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1378 /* Dag nab it. */
1379 if (__mprotect ((caddr_t) (zero
1380 & ~(GLRO(dl_pagesize) - 1)),
1381 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1383 errstring = N_("cannot change memory protections");
1384 goto call_lose_errno;
1387 memset ((void *) zero, '\0', zeropage - zero);
1388 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1389 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1390 GLRO(dl_pagesize), c->prot);
1393 if (zeroend > zeropage)
1395 /* Map the remaining zero pages in from the zero fill FD. */
1396 caddr_t mapat;
1397 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1398 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1399 -1, 0);
1400 if (__builtin_expect (mapat == MAP_FAILED, 0))
1402 errstring = N_("cannot map zero-fill pages");
1403 goto call_lose_errno;
1408 ++c;
1412 if (l->l_ld == 0)
1414 if (__builtin_expect (type == ET_DYN, 0))
1416 errstring = N_("object file has no dynamic section");
1417 goto call_lose;
1420 else
1421 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1423 elf_get_dynamic_info (l, NULL);
1425 /* Make sure we are not dlopen'ing an object that has the
1426 DF_1_NOOPEN flag set. */
1427 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1428 && (mode & __RTLD_DLOPEN))
1430 /* We are not supposed to load this object. Free all resources. */
1431 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1433 if (!l->l_libname->dont_free)
1434 free (l->l_libname);
1436 if (l->l_phdr_allocated)
1437 free ((void *) l->l_phdr);
1439 errstring = N_("shared object cannot be dlopen()ed");
1440 goto call_lose;
1443 if (l->l_phdr == NULL)
1445 /* The program header is not contained in any of the segments.
1446 We have to allocate memory ourself and copy it over from out
1447 temporary place. */
1448 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1449 * sizeof (ElfW(Phdr)));
1450 if (newp == NULL)
1452 errstring = N_("cannot allocate memory for program header");
1453 goto call_lose_errno;
1456 l->l_phdr = memcpy (newp, phdr,
1457 (header->e_phnum * sizeof (ElfW(Phdr))));
1458 l->l_phdr_allocated = 1;
1460 else
1461 /* Adjust the PT_PHDR value by the runtime load address. */
1462 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1464 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1466 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso),
1467 0) != 0)
1469 errstring = N_("invalid caller");
1470 goto call_lose;
1473 /* The stack is presently not executable, but this module
1474 requires that it be executable. We must change the
1475 protection of the variable which contains the flags used in
1476 the mprotect calls. */
1477 #ifdef SHARED
1478 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1480 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1481 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1483 struct link_map *const m = &GL(dl_rtld_map);
1484 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1485 + m->l_relro_size)
1486 & -GLRO(dl_pagesize));
1487 if (__builtin_expect (p + s <= relro_end, 1))
1489 /* The variable lies in the region protected by RELRO. */
1490 if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
1492 errstring = N_("cannot change memory protections");
1493 goto call_lose_errno;
1495 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1496 __mprotect ((void *) p, s, PROT_READ);
1498 else
1499 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1501 else
1502 #endif
1503 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1505 #ifdef check_consistency
1506 check_consistency ();
1507 #endif
1509 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1510 if (errval)
1512 errstring = N_("\
1513 cannot enable executable stack as shared object requires");
1514 goto call_lose;
1518 /* Adjust the address of the TLS initialization image. */
1519 if (l->l_tls_initimage != NULL)
1520 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1522 /* We are done mapping in the file. We no longer need the descriptor. */
1523 if (__builtin_expect (__close (fd) != 0, 0))
1525 errstring = N_("cannot close file descriptor");
1526 goto call_lose_errno;
1528 /* Signal that we closed the file. */
1529 fd = -1;
1531 if (l->l_type == lt_library && type == ET_EXEC)
1532 l->l_type = lt_executable;
1534 l->l_entry += l->l_addr;
1536 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1537 _dl_debug_printf ("\
1538 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1539 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1540 (int) sizeof (void *) * 2,
1541 (unsigned long int) l->l_ld,
1542 (int) sizeof (void *) * 2,
1543 (unsigned long int) l->l_addr,
1544 (int) sizeof (void *) * 2, maplength,
1545 (int) sizeof (void *) * 2,
1546 (unsigned long int) l->l_entry,
1547 (int) sizeof (void *) * 2,
1548 (unsigned long int) l->l_phdr,
1549 (int) sizeof (void *) * 2, l->l_phnum);
1551 /* Set up the symbol hash table. */
1552 _dl_setup_hash (l);
1554 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1555 have to do this for the main map. */
1556 if ((mode & RTLD_DEEPBIND) == 0
1557 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1558 && &l->l_searchlist != l->l_scope[0])
1560 /* Create an appropriate searchlist. It contains only this map.
1561 This is the definition of DT_SYMBOLIC in SysVr4. */
1562 l->l_symbolic_searchlist.r_list[0] = l;
1563 l->l_symbolic_searchlist.r_nlist = 1;
1565 /* Now move the existing entries one back. */
1566 memmove (&l->l_scope[1], &l->l_scope[0],
1567 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1569 /* Now add the new entry. */
1570 l->l_scope[0] = &l->l_symbolic_searchlist;
1573 /* Remember whether this object must be initialized first. */
1574 if (l->l_flags_1 & DF_1_INITFIRST)
1575 GL(dl_initfirst) = l;
1577 /* Finally the file information. */
1578 l->l_dev = st.st_dev;
1579 l->l_ino = st.st_ino;
1581 /* When we profile the SONAME might be needed for something else but
1582 loading. Add it right away. */
1583 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1584 && l->l_info[DT_SONAME] != NULL)
1585 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1586 + l->l_info[DT_SONAME]->d_un.d_val));
1588 #ifdef DL_AFTER_LOAD
1589 DL_AFTER_LOAD (l);
1590 #endif
1592 /* Now that the object is fully initialized add it to the object list. */
1593 _dl_add_to_namespace_list (l, nsid);
1595 #ifdef SHARED
1596 /* Auditing checkpoint: we have a new object. */
1597 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
1598 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1600 struct audit_ifaces *afct = GLRO(dl_audit);
1601 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1603 if (afct->objopen != NULL)
1605 l->l_audit[cnt].bindflags
1606 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1608 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1611 afct = afct->next;
1614 #endif
1616 return l;
1619 /* Print search path. */
1620 static void
1621 print_search_path (struct r_search_path_elem **list,
1622 const char *what, const char *name)
1624 char buf[max_dirnamelen + max_capstrlen];
1625 int first = 1;
1627 _dl_debug_printf (" search path=");
1629 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1631 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1632 size_t cnt;
1634 for (cnt = 0; cnt < ncapstr; ++cnt)
1635 if ((*list)->status[cnt] != nonexisting)
1637 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1638 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1639 cp[0] = '\0';
1640 else
1641 cp[-1] = '\0';
1643 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1644 first = 0;
1647 ++list;
1650 if (name != NULL)
1651 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1652 DSO_FILENAME (name));
1653 else
1654 _dl_debug_printf_c ("\t\t(%s)\n", what);
1657 /* Open a file and verify it is an ELF file for this architecture. We
1658 ignore only ELF files for other architectures. Non-ELF files and
1659 ELF files with different header information cause fatal errors since
1660 this could mean there is something wrong in the installation and the
1661 user might want to know about this. */
1662 static int
1663 open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
1664 int whatcode, bool *found_other_class, bool free_name)
1666 /* This is the expected ELF header. */
1667 #define ELF32_CLASS ELFCLASS32
1668 #define ELF64_CLASS ELFCLASS64
1669 #ifndef VALID_ELF_HEADER
1670 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1671 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1672 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1673 #elif defined MORE_ELF_HEADER_DATA
1674 MORE_ELF_HEADER_DATA;
1675 #endif
1676 static const unsigned char expected[EI_NIDENT] =
1678 [EI_MAG0] = ELFMAG0,
1679 [EI_MAG1] = ELFMAG1,
1680 [EI_MAG2] = ELFMAG2,
1681 [EI_MAG3] = ELFMAG3,
1682 [EI_CLASS] = ELFW(CLASS),
1683 [EI_DATA] = byteorder,
1684 [EI_VERSION] = EV_CURRENT,
1685 [EI_OSABI] = ELFOSABI_SYSV,
1686 [EI_ABIVERSION] = 0
1688 static const struct
1690 ElfW(Word) vendorlen;
1691 ElfW(Word) datalen;
1692 ElfW(Word) type;
1693 char vendor[4];
1694 } expected_note = { 4, 16, 1, "GNU" };
1695 /* Initialize it to make the compiler happy. */
1696 const char *errstring = NULL;
1697 int errval = 0;
1699 #ifdef SHARED
1700 /* Give the auditing libraries a chance. */
1701 if (__builtin_expect (GLRO(dl_naudit) > 0, 0) && whatcode != 0
1702 && loader->l_auditing == 0)
1704 struct audit_ifaces *afct = GLRO(dl_audit);
1705 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1707 if (afct->objsearch != NULL)
1709 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1710 whatcode);
1711 if (name == NULL)
1712 /* Ignore the path. */
1713 return -1;
1716 afct = afct->next;
1719 #endif
1721 /* Open the file. We always open files read-only. */
1722 int fd = __open (name, O_RDONLY | O_CLOEXEC);
1723 if (fd != -1)
1725 ElfW(Ehdr) *ehdr;
1726 ElfW(Phdr) *phdr, *ph;
1727 ElfW(Word) *abi_note;
1728 unsigned int osversion;
1729 size_t maplength;
1731 /* We successfully openened the file. Now verify it is a file
1732 we can use. */
1733 __set_errno (0);
1734 fbp->len = 0;
1735 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1736 /* Read in the header. */
1739 ssize_t retlen = __libc_read (fd, fbp->buf + fbp->len,
1740 sizeof (fbp->buf) - fbp->len);
1741 if (retlen <= 0)
1742 break;
1743 fbp->len += retlen;
1745 while (__builtin_expect (fbp->len < sizeof (ElfW(Ehdr)), 0));
1747 /* This is where the ELF header is loaded. */
1748 ehdr = (ElfW(Ehdr) *) fbp->buf;
1750 /* Now run the tests. */
1751 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1753 errval = errno;
1754 errstring = (errval == 0
1755 ? N_("file too short") : N_("cannot read file data"));
1756 call_lose:
1757 if (free_name)
1759 char *realname = (char *) name;
1760 name = strdupa (realname);
1761 free (realname);
1763 lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
1766 /* See whether the ELF header is what we expect. */
1767 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1768 EI_ABIVERSION)
1769 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1770 ehdr->e_ident[EI_ABIVERSION])
1771 || memcmp (&ehdr->e_ident[EI_PAD],
1772 &expected[EI_PAD],
1773 EI_NIDENT - EI_PAD) != 0,
1776 /* Something is wrong. */
1777 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1778 if (*magp !=
1779 #if BYTE_ORDER == LITTLE_ENDIAN
1780 ((ELFMAG0 << (EI_MAG0 * 8)) |
1781 (ELFMAG1 << (EI_MAG1 * 8)) |
1782 (ELFMAG2 << (EI_MAG2 * 8)) |
1783 (ELFMAG3 << (EI_MAG3 * 8)))
1784 #else
1785 ((ELFMAG0 << (EI_MAG3 * 8)) |
1786 (ELFMAG1 << (EI_MAG2 * 8)) |
1787 (ELFMAG2 << (EI_MAG1 * 8)) |
1788 (ELFMAG3 << (EI_MAG0 * 8)))
1789 #endif
1791 errstring = N_("invalid ELF header");
1792 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1794 /* This is not a fatal error. On architectures where
1795 32-bit and 64-bit binaries can be run this might
1796 happen. */
1797 *found_other_class = true;
1798 goto close_and_out;
1800 else if (ehdr->e_ident[EI_DATA] != byteorder)
1802 if (BYTE_ORDER == BIG_ENDIAN)
1803 errstring = N_("ELF file data encoding not big-endian");
1804 else
1805 errstring = N_("ELF file data encoding not little-endian");
1807 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1808 errstring
1809 = N_("ELF file version ident does not match current one");
1810 /* XXX We should be able so set system specific versions which are
1811 allowed here. */
1812 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1813 errstring = N_("ELF file OS ABI invalid");
1814 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1815 ehdr->e_ident[EI_ABIVERSION]))
1816 errstring = N_("ELF file ABI version invalid");
1817 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1818 EI_NIDENT - EI_PAD) != 0)
1819 errstring = N_("nonzero padding in e_ident");
1820 else
1821 /* Otherwise we don't know what went wrong. */
1822 errstring = N_("internal error");
1824 goto call_lose;
1827 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1829 errstring = N_("ELF file version does not match current one");
1830 goto call_lose;
1832 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1833 goto close_and_out;
1834 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1835 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1837 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1838 goto call_lose;
1840 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1841 != sizeof (ElfW(Phdr)))
1843 errstring = N_("ELF file's phentsize not the expected size");
1844 goto call_lose;
1847 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1848 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1849 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1850 else
1852 phdr = alloca (maplength);
1853 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1854 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1856 read_error:
1857 errval = errno;
1858 errstring = N_("cannot read file data");
1859 goto call_lose;
1863 /* Check .note.ABI-tag if present. */
1864 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1865 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1867 ElfW(Addr) size = ph->p_filesz;
1869 if (ph->p_offset + size <= (size_t) fbp->len)
1870 abi_note = (void *) (fbp->buf + ph->p_offset);
1871 else
1873 abi_note = alloca (size);
1874 __lseek (fd, ph->p_offset, SEEK_SET);
1875 if (__libc_read (fd, (void *) abi_note, size) != size)
1876 goto read_error;
1879 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1881 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1882 ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
1883 + ROUND (abi_note[0])
1884 + ROUND (abi_note[1]);
1886 if (size - 32 < note_size)
1888 size = 0;
1889 break;
1891 size -= note_size;
1892 abi_note = (void *) abi_note + note_size;
1895 if (size == 0)
1896 continue;
1898 osversion = (abi_note[5] & 0xff) * 65536
1899 + (abi_note[6] & 0xff) * 256
1900 + (abi_note[7] & 0xff);
1901 if (abi_note[4] != __ABI_TAG_OS
1902 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1904 close_and_out:
1905 __close (fd);
1906 __set_errno (ENOENT);
1907 fd = -1;
1910 break;
1914 return fd;
1917 /* Try to open NAME in one of the directories in *DIRSP.
1918 Return the fd, or -1. If successful, fill in *REALNAME
1919 with the malloc'd full directory name. If it turns out
1920 that none of the directories in *DIRSP exists, *DIRSP is
1921 replaced with (void *) -1, and the old value is free()d
1922 if MAY_FREE_DIRS is true. */
1924 static int
1925 open_path (const char *name, size_t namelen, int secure,
1926 struct r_search_path_struct *sps, char **realname,
1927 struct filebuf *fbp, struct link_map *loader, int whatcode,
1928 bool *found_other_class)
1930 struct r_search_path_elem **dirs = sps->dirs;
1931 char *buf;
1932 int fd = -1;
1933 const char *current_what = NULL;
1934 int any = 0;
1936 if (__builtin_expect (dirs == NULL, 0))
1937 /* We're called before _dl_init_paths when loading the main executable
1938 given on the command line when rtld is run directly. */
1939 return -1;
1941 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1944 struct r_search_path_elem *this_dir = *dirs;
1945 size_t buflen = 0;
1946 size_t cnt;
1947 char *edp;
1948 int here_any = 0;
1949 int err;
1951 /* If we are debugging the search for libraries print the path
1952 now if it hasn't happened now. */
1953 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1954 && current_what != this_dir->what)
1956 current_what = this_dir->what;
1957 print_search_path (dirs, current_what, this_dir->where);
1960 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1961 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1963 /* Skip this directory if we know it does not exist. */
1964 if (this_dir->status[cnt] == nonexisting)
1965 continue;
1967 buflen =
1968 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1969 capstr[cnt].len),
1970 name, namelen)
1971 - buf);
1973 /* Print name we try if this is wanted. */
1974 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1975 _dl_debug_printf (" trying file=%s\n", buf);
1977 fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
1978 false);
1979 if (this_dir->status[cnt] == unknown)
1981 if (fd != -1)
1982 this_dir->status[cnt] = existing;
1983 /* Do not update the directory information when loading
1984 auditing code. We must try to disturb the program as
1985 little as possible. */
1986 else if (loader == NULL
1987 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1989 /* We failed to open machine dependent library. Let's
1990 test whether there is any directory at all. */
1991 struct stat64 st;
1993 buf[buflen - namelen - 1] = '\0';
1995 if (__xstat64 (_STAT_VER, buf, &st) != 0
1996 || ! S_ISDIR (st.st_mode))
1997 /* The directory does not exist or it is no directory. */
1998 this_dir->status[cnt] = nonexisting;
1999 else
2000 this_dir->status[cnt] = existing;
2004 /* Remember whether we found any existing directory. */
2005 here_any |= this_dir->status[cnt] != nonexisting;
2007 if (fd != -1 && __builtin_expect (secure, 0)
2008 && INTUSE(__libc_enable_secure))
2010 /* This is an extra security effort to make sure nobody can
2011 preload broken shared objects which are in the trusted
2012 directories and so exploit the bugs. */
2013 struct stat64 st;
2015 if (__fxstat64 (_STAT_VER, fd, &st) != 0
2016 || (st.st_mode & S_ISUID) == 0)
2018 /* The shared object cannot be tested for being SUID
2019 or this bit is not set. In this case we must not
2020 use this object. */
2021 __close (fd);
2022 fd = -1;
2023 /* We simply ignore the file, signal this by setting
2024 the error value which would have been set by `open'. */
2025 errno = ENOENT;
2030 if (fd != -1)
2032 *realname = (char *) malloc (buflen);
2033 if (*realname != NULL)
2035 memcpy (*realname, buf, buflen);
2036 return fd;
2038 else
2040 /* No memory for the name, we certainly won't be able
2041 to load and link it. */
2042 __close (fd);
2043 return -1;
2046 if (here_any && (err = errno) != ENOENT && err != EACCES)
2047 /* The file exists and is readable, but something went wrong. */
2048 return -1;
2050 /* Remember whether we found anything. */
2051 any |= here_any;
2053 while (*++dirs != NULL);
2055 /* Remove the whole path if none of the directories exists. */
2056 if (__builtin_expect (! any, 0))
2058 /* Paths which were allocated using the minimal malloc() in ld.so
2059 must not be freed using the general free() in libc. */
2060 if (sps->malloced)
2061 free (sps->dirs);
2063 /* rtld_search_dirs is attribute_relro, therefore avoid writing
2064 into it. */
2065 if (sps != &rtld_search_dirs)
2066 sps->dirs = (void *) -1;
2069 return -1;
2072 /* Map in the shared object file NAME. */
2074 struct link_map *
2075 internal_function
2076 _dl_map_object (struct link_map *loader, const char *name,
2077 int type, int trace_mode, int mode, Lmid_t nsid)
2079 int fd;
2080 char *realname;
2081 char *name_copy;
2082 struct link_map *l;
2083 struct filebuf fb;
2085 assert (nsid >= 0);
2086 assert (nsid < GL(dl_nns));
2088 /* Look for this name among those already loaded. */
2089 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
2091 /* If the requested name matches the soname of a loaded object,
2092 use that object. Elide this check for names that have not
2093 yet been opened. */
2094 if (__builtin_expect (l->l_faked, 0) != 0
2095 || __builtin_expect (l->l_removed, 0) != 0)
2096 continue;
2097 if (!_dl_name_match_p (name, l))
2099 const char *soname;
2101 if (__builtin_expect (l->l_soname_added, 1)
2102 || l->l_info[DT_SONAME] == NULL)
2103 continue;
2105 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
2106 + l->l_info[DT_SONAME]->d_un.d_val);
2107 if (strcmp (name, soname) != 0)
2108 continue;
2110 /* We have a match on a new name -- cache it. */
2111 add_name_to_object (l, soname);
2112 l->l_soname_added = 1;
2115 /* We have a match. */
2116 return l;
2119 /* Display information if we are debugging. */
2120 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
2121 && loader != NULL)
2122 _dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
2123 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
2124 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
2125 name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
2127 #ifdef SHARED
2128 /* Give the auditing libraries a chance to change the name before we
2129 try anything. */
2130 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
2131 && (loader == NULL || loader->l_auditing == 0))
2133 struct audit_ifaces *afct = GLRO(dl_audit);
2134 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2136 if (afct->objsearch != NULL)
2138 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
2139 LA_SER_ORIG);
2140 if (name == NULL)
2142 /* Do not try anything further. */
2143 fd = -1;
2144 goto no_file;
2148 afct = afct->next;
2151 #endif
2153 /* Will be true if we found a DSO which is of the other ELF class. */
2154 bool found_other_class = false;
2156 if (strchr (name, '/') == NULL)
2158 /* Search for NAME in several places. */
2160 size_t namelen = strlen (name) + 1;
2162 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2163 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2165 fd = -1;
2167 /* When the object has the RUNPATH information we don't use any
2168 RPATHs. */
2169 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2171 /* This is the executable's map (if there is one). Make sure that
2172 we do not look at it twice. */
2173 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2174 bool did_main_map = false;
2176 /* First try the DT_RPATH of the dependent object that caused NAME
2177 to be loaded. Then that object's dependent, and on up. */
2178 for (l = loader; l; l = l->l_loader)
2179 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2181 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2182 &l->l_rpath_dirs,
2183 &realname, &fb, loader, LA_SER_RUNPATH,
2184 &found_other_class);
2185 if (fd != -1)
2186 break;
2188 did_main_map |= l == main_map;
2191 /* If dynamically linked, try the DT_RPATH of the executable
2192 itself. NB: we do this for lookups in any namespace. */
2193 if (fd == -1 && !did_main_map
2194 && main_map != NULL && main_map->l_type != lt_loaded
2195 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2196 "RPATH"))
2197 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2198 &main_map->l_rpath_dirs,
2199 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2200 &found_other_class);
2203 /* Try the LD_LIBRARY_PATH environment variable. */
2204 if (fd == -1 && env_path_list.dirs != (void *) -1)
2205 fd = open_path (name, namelen, mode & __RTLD_SECURE, &env_path_list,
2206 &realname, &fb,
2207 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2208 LA_SER_LIBPATH, &found_other_class);
2210 /* Look at the RUNPATH information for this binary. */
2211 if (fd == -1 && loader != NULL
2212 && cache_rpath (loader, &loader->l_runpath_dirs,
2213 DT_RUNPATH, "RUNPATH"))
2214 fd = open_path (name, namelen, mode & __RTLD_SECURE,
2215 &loader->l_runpath_dirs, &realname, &fb, loader,
2216 LA_SER_RUNPATH, &found_other_class);
2218 #ifdef USE_LDCONFIG
2219 if (fd == -1
2220 && (__builtin_expect (! (mode & __RTLD_SECURE), 1)
2221 || ! INTUSE(__libc_enable_secure))
2222 && __builtin_expect (GLRO(dl_inhibit_cache) == 0, 1))
2224 /* Check the list of libraries in the file /etc/ld.so.cache,
2225 for compatibility with Linux's ldconfig program. */
2226 const char *cached = _dl_load_cache_lookup (name);
2228 if (cached != NULL)
2230 # ifdef SHARED
2231 // XXX Correct to unconditionally default to namespace 0?
2232 l = (loader
2233 ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
2234 ?: &GL(dl_rtld_map));
2235 # else
2236 l = loader;
2237 # endif
2239 /* If the loader has the DF_1_NODEFLIB flag set we must not
2240 use a cache entry from any of these directories. */
2241 if (
2242 # ifndef SHARED
2243 /* 'l' is always != NULL for dynamically linked objects. */
2244 l != NULL &&
2245 # endif
2246 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
2248 const char *dirp = system_dirs;
2249 unsigned int cnt = 0;
2253 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2255 /* The prefix matches. Don't use the entry. */
2256 cached = NULL;
2257 break;
2260 dirp += system_dirs_len[cnt] + 1;
2261 ++cnt;
2263 while (cnt < nsystem_dirs_len);
2266 if (cached != NULL)
2268 fd = open_verify (cached,
2269 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2270 LA_SER_CONFIG, &found_other_class, false);
2271 if (__builtin_expect (fd != -1, 1))
2273 realname = local_strdup (cached);
2274 if (realname == NULL)
2276 __close (fd);
2277 fd = -1;
2283 #endif
2285 /* Finally, try the default path. */
2286 if (fd == -1
2287 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2288 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
2289 && rtld_search_dirs.dirs != (void *) -1)
2290 fd = open_path (name, namelen, mode & __RTLD_SECURE, &rtld_search_dirs,
2291 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2293 /* Add another newline when we are tracing the library loading. */
2294 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2295 _dl_debug_printf ("\n");
2297 else
2299 /* The path may contain dynamic string tokens. */
2300 realname = (loader
2301 ? expand_dynamic_string_token (loader, name, 0)
2302 : local_strdup (name));
2303 if (realname == NULL)
2304 fd = -1;
2305 else
2307 fd = open_verify (realname, &fb,
2308 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
2309 &found_other_class, true);
2310 if (__builtin_expect (fd, 0) == -1)
2311 free (realname);
2315 #ifdef SHARED
2316 no_file:
2317 #endif
2318 /* In case the LOADER information has only been provided to get to
2319 the appropriate RUNPATH/RPATH information we do not need it
2320 anymore. */
2321 if (mode & __RTLD_CALLMAP)
2322 loader = NULL;
2324 if (__builtin_expect (fd, 0) == -1)
2326 if (trace_mode
2327 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
2329 /* We haven't found an appropriate library. But since we
2330 are only interested in the list of libraries this isn't
2331 so severe. Fake an entry with all the information we
2332 have. */
2333 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2335 /* Allocate a new object map. */
2336 if ((name_copy = local_strdup (name)) == NULL
2337 || (l = _dl_new_object (name_copy, name, type, loader,
2338 mode, nsid)) == NULL)
2340 free (name_copy);
2341 _dl_signal_error (ENOMEM, name, NULL,
2342 N_("cannot create shared object descriptor"));
2344 /* Signal that this is a faked entry. */
2345 l->l_faked = 1;
2346 /* Since the descriptor is initialized with zero we do not
2347 have do this here.
2348 l->l_reserved = 0; */
2349 l->l_buckets = &dummy_bucket;
2350 l->l_nbuckets = 1;
2351 l->l_relocated = 1;
2353 /* Enter the object in the object list. */
2354 _dl_add_to_namespace_list (l, nsid);
2356 return l;
2358 else if (found_other_class)
2359 _dl_signal_error (0, name, NULL,
2360 ELFW(CLASS) == ELFCLASS32
2361 ? N_("wrong ELF class: ELFCLASS64")
2362 : N_("wrong ELF class: ELFCLASS32"));
2363 else
2364 _dl_signal_error (errno, name, NULL,
2365 N_("cannot open shared object file"));
2368 void *stack_end = __libc_stack_end;
2369 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
2370 &stack_end, nsid);
2374 void
2375 internal_function
2376 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2378 if (counting)
2380 si->dls_cnt = 0;
2381 si->dls_size = 0;
2384 unsigned int idx = 0;
2385 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2386 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2387 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2389 if (sps->dirs != (void *) -1)
2391 struct r_search_path_elem **dirs = sps->dirs;
2394 const struct r_search_path_elem *const r = *dirs++;
2395 if (counting)
2397 si->dls_cnt++;
2398 si->dls_size += MAX (2, r->dirnamelen);
2400 else
2402 Dl_serpath *const sp = &si->dls_serpath[idx++];
2403 sp->dls_name = allocptr;
2404 if (r->dirnamelen < 2)
2405 *allocptr++ = r->dirnamelen ? '/' : '.';
2406 else
2407 allocptr = __mempcpy (allocptr,
2408 r->dirname, r->dirnamelen - 1);
2409 *allocptr++ = '\0';
2410 sp->dls_flags = flags;
2413 while (*dirs != NULL);
2417 /* When the object has the RUNPATH information we don't use any RPATHs. */
2418 if (loader->l_info[DT_RUNPATH] == NULL)
2420 /* First try the DT_RPATH of the dependent object that caused NAME
2421 to be loaded. Then that object's dependent, and on up. */
2423 struct link_map *l = loader;
2426 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2427 add_path (&l->l_rpath_dirs, XXX_RPATH);
2428 l = l->l_loader;
2430 while (l != NULL);
2432 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2433 if (loader->l_ns == LM_ID_BASE)
2435 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2436 if (l != NULL && l->l_type != lt_loaded && l != loader)
2437 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2438 add_path (&l->l_rpath_dirs, XXX_RPATH);
2442 /* Try the LD_LIBRARY_PATH environment variable. */
2443 add_path (&env_path_list, XXX_ENV);
2445 /* Look at the RUNPATH information for this binary. */
2446 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2447 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2449 /* XXX
2450 Here is where ld.so.cache gets checked, but we don't have
2451 a way to indicate that in the results for Dl_serinfo. */
2453 /* Finally, try the default path. */
2454 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2455 add_path (&rtld_search_dirs, XXX_default);
2457 if (counting)
2458 /* Count the struct size before the string area, which we didn't
2459 know before we completed dls_cnt. */
2460 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;