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[glibc.git] / elf / dl-load.c
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1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006, 2007, 2009, 2010 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, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <elf.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <libintl.h>
24 #include <stdbool.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 #include <ldsodefs.h>
29 #include <bits/wordsize.h>
30 #include <sys/mman.h>
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
35 #include <abi-tag.h>
36 #include <stackinfo.h>
37 #include <caller.h>
38 #include <sysdep.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 size_t
172 is_dst (const char *start, const char *name, const char *str,
173 int is_path, int secure)
175 size_t len;
176 bool is_curly = false;
178 if (name[0] == '{')
180 is_curly = true;
181 ++name;
184 len = 0;
185 while (name[len] == str[len] && name[len] != '\0')
186 ++len;
188 if (is_curly)
190 if (name[len] != '}')
191 return 0;
193 /* Point again at the beginning of the name. */
194 --name;
195 /* Skip over closing curly brace and adjust for the --name. */
196 len += 2;
198 else if (name[len] != '\0' && name[len] != '/'
199 && (!is_path || name[len] != ':'))
200 return 0;
202 if (__builtin_expect (secure, 0)
203 && ((name[len] != '\0' && (!is_path || name[len] != ':'))
204 || (name != start + 1 && (!is_path || name[-2] != ':'))))
205 return 0;
207 return len;
211 size_t
212 _dl_dst_count (const char *name, int is_path)
214 const char *const start = name;
215 size_t cnt = 0;
219 size_t len;
221 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
222 is $ORIGIN alone) and it must always appear first in path. */
223 ++name;
224 if ((len = is_dst (start, name, "ORIGIN", is_path,
225 INTUSE(__libc_enable_secure))) != 0
226 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
227 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
228 ++cnt;
230 name = strchr (name + len, '$');
232 while (name != NULL);
234 return cnt;
238 char *
239 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
240 int is_path)
242 const char *const start = name;
243 char *last_elem, *wp;
245 /* Now fill the result path. While copying over the string we keep
246 track of the start of the last path element. When we come accross
247 a DST we copy over the value or (if the value is not available)
248 leave the entire path element out. */
249 last_elem = wp = result;
253 if (__builtin_expect (*name == '$', 0))
255 const char *repl = NULL;
256 size_t len;
258 ++name;
259 if ((len = is_dst (start, name, "ORIGIN", is_path,
260 INTUSE(__libc_enable_secure))) != 0)
262 #ifndef SHARED
263 if (l == NULL)
264 repl = _dl_get_origin ();
265 else
266 #endif
267 repl = l->l_origin;
269 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
270 repl = GLRO(dl_platform);
271 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
272 repl = DL_DST_LIB;
274 if (repl != NULL && repl != (const char *) -1)
276 wp = __stpcpy (wp, repl);
277 name += len;
279 else if (len > 1)
281 /* We cannot use this path element, the value of the
282 replacement is unknown. */
283 wp = last_elem;
284 name += len;
285 while (*name != '\0' && (!is_path || *name != ':'))
286 ++name;
288 else
289 /* No DST we recognize. */
290 *wp++ = '$';
292 else
294 *wp++ = *name++;
295 if (is_path && *name == ':')
296 last_elem = wp;
299 while (*name != '\0');
301 *wp = '\0';
303 return result;
307 /* Return copy of argument with all recognized dynamic string tokens
308 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
309 might not be possible to determine the path from which the object
310 belonging to the map is loaded. In this case the path element
311 containing $ORIGIN is left out. */
312 static char *
313 expand_dynamic_string_token (struct link_map *l, const char *s)
315 /* We make two runs over the string. First we determine how large the
316 resulting string is and then we copy it over. Since this is no
317 frequently executed operation we are looking here not for performance
318 but rather for code size. */
319 size_t cnt;
320 size_t total;
321 char *result;
323 /* Determine the number of DST elements. */
324 cnt = DL_DST_COUNT (s, 1);
326 /* If we do not have to replace anything simply copy the string. */
327 if (__builtin_expect (cnt, 0) == 0)
328 return local_strdup (s);
330 /* Determine the length of the substituted string. */
331 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
333 /* Allocate the necessary memory. */
334 result = (char *) malloc (total + 1);
335 if (result == NULL)
336 return NULL;
338 return _dl_dst_substitute (l, s, result, 1);
342 /* Add `name' to the list of names for a particular shared object.
343 `name' is expected to have been allocated with malloc and will
344 be freed if the shared object already has this name.
345 Returns false if the object already had this name. */
346 static void
347 internal_function
348 add_name_to_object (struct link_map *l, const char *name)
350 struct libname_list *lnp, *lastp;
351 struct libname_list *newname;
352 size_t name_len;
354 lastp = NULL;
355 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
356 if (strcmp (name, lnp->name) == 0)
357 return;
359 name_len = strlen (name) + 1;
360 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
361 if (newname == NULL)
363 /* No more memory. */
364 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
365 return;
367 /* The object should have a libname set from _dl_new_object. */
368 assert (lastp != NULL);
370 newname->name = memcpy (newname + 1, name, name_len);
371 newname->next = NULL;
372 newname->dont_free = 0;
373 lastp->next = newname;
376 /* Standard search directories. */
377 static struct r_search_path_struct rtld_search_dirs attribute_relro;
379 static size_t max_dirnamelen;
381 static struct r_search_path_elem **
382 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
383 int check_trusted, const char *what, const char *where)
385 char *cp;
386 size_t nelems = 0;
388 while ((cp = __strsep (&rpath, sep)) != NULL)
390 struct r_search_path_elem *dirp;
391 size_t len = strlen (cp);
393 /* `strsep' can pass an empty string. This has to be
394 interpreted as `use the current directory'. */
395 if (len == 0)
397 static const char curwd[] = "./";
398 cp = (char *) curwd;
401 /* Remove trailing slashes (except for "/"). */
402 while (len > 1 && cp[len - 1] == '/')
403 --len;
405 /* Now add one if there is none so far. */
406 if (len > 0 && cp[len - 1] != '/')
407 cp[len++] = '/';
409 /* Make sure we don't use untrusted directories if we run SUID. */
410 if (__builtin_expect (check_trusted, 0))
412 const char *trun = system_dirs;
413 size_t idx;
414 int unsecure = 1;
416 /* All trusted directories must be complete names. */
417 if (cp[0] == '/')
419 for (idx = 0; idx < nsystem_dirs_len; ++idx)
421 if (len == system_dirs_len[idx]
422 && memcmp (trun, cp, len) == 0)
424 /* Found it. */
425 unsecure = 0;
426 break;
429 trun += system_dirs_len[idx] + 1;
433 if (unsecure)
434 /* Simply drop this directory. */
435 continue;
438 /* See if this directory is already known. */
439 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
440 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
441 break;
443 if (dirp != NULL)
445 /* It is available, see whether it's on our own list. */
446 size_t cnt;
447 for (cnt = 0; cnt < nelems; ++cnt)
448 if (result[cnt] == dirp)
449 break;
451 if (cnt == nelems)
452 result[nelems++] = dirp;
454 else
456 size_t cnt;
457 enum r_dir_status init_val;
458 size_t where_len = where ? strlen (where) + 1 : 0;
460 /* It's a new directory. Create an entry and add it. */
461 dirp = (struct r_search_path_elem *)
462 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
463 + where_len + len + 1);
464 if (dirp == NULL)
465 _dl_signal_error (ENOMEM, NULL, NULL,
466 N_("cannot create cache for search path"));
468 dirp->dirname = ((char *) dirp + sizeof (*dirp)
469 + ncapstr * sizeof (enum r_dir_status));
470 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
471 dirp->dirnamelen = len;
473 if (len > max_dirnamelen)
474 max_dirnamelen = len;
476 /* We have to make sure all the relative directories are
477 never ignored. The current directory might change and
478 all our saved information would be void. */
479 init_val = cp[0] != '/' ? existing : unknown;
480 for (cnt = 0; cnt < ncapstr; ++cnt)
481 dirp->status[cnt] = init_val;
483 dirp->what = what;
484 if (__builtin_expect (where != NULL, 1))
485 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
486 + (ncapstr * sizeof (enum r_dir_status)),
487 where, where_len);
488 else
489 dirp->where = NULL;
491 dirp->next = GL(dl_all_dirs);
492 GL(dl_all_dirs) = dirp;
494 /* Put it in the result array. */
495 result[nelems++] = dirp;
499 /* Terminate the array. */
500 result[nelems] = NULL;
502 return result;
506 static bool
507 internal_function
508 decompose_rpath (struct r_search_path_struct *sps,
509 const char *rpath, struct link_map *l, const char *what)
511 /* Make a copy we can work with. */
512 const char *where = l->l_name;
513 char *copy;
514 char *cp;
515 struct r_search_path_elem **result;
516 size_t nelems;
517 /* Initialize to please the compiler. */
518 const char *errstring = NULL;
520 /* First see whether we must forget the RUNPATH and RPATH from this
521 object. */
522 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
523 && !INTUSE(__libc_enable_secure))
525 const char *inhp = GLRO(dl_inhibit_rpath);
529 const char *wp = where;
531 while (*inhp == *wp && *wp != '\0')
533 ++inhp;
534 ++wp;
537 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
539 /* This object is on the list of objects for which the
540 RUNPATH and RPATH must not be used. */
541 sps->dirs = (void *) -1;
542 return false;
545 while (*inhp != '\0')
546 if (*inhp++ == ':')
547 break;
549 while (*inhp != '\0');
552 /* Make a writable copy. At the same time expand possible dynamic
553 string tokens. */
554 copy = expand_dynamic_string_token (l, rpath);
555 if (copy == NULL)
557 errstring = N_("cannot create RUNPATH/RPATH copy");
558 goto signal_error;
561 /* Count the number of necessary elements in the result array. */
562 nelems = 0;
563 for (cp = copy; *cp != '\0'; ++cp)
564 if (*cp == ':')
565 ++nelems;
567 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
568 number of necessary entries. */
569 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
570 * sizeof (*result));
571 if (result == NULL)
573 free (copy);
574 errstring = N_("cannot create cache for search path");
575 signal_error:
576 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
579 fillin_rpath (copy, result, ":", 0, what, where);
581 /* Free the copied RPATH string. `fillin_rpath' make own copies if
582 necessary. */
583 free (copy);
585 sps->dirs = result;
586 /* The caller will change this value if we haven't used a real malloc. */
587 sps->malloced = 1;
588 return true;
591 /* Make sure cached path information is stored in *SP
592 and return true if there are any paths to search there. */
593 static bool
594 cache_rpath (struct link_map *l,
595 struct r_search_path_struct *sp,
596 int tag,
597 const char *what)
599 if (sp->dirs == (void *) -1)
600 return false;
602 if (sp->dirs != NULL)
603 return true;
605 if (l->l_info[tag] == NULL)
607 /* There is no path. */
608 sp->dirs = (void *) -1;
609 return false;
612 /* Make sure the cache information is available. */
613 return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
614 + l->l_info[tag]->d_un.d_val),
615 l, what);
619 void
620 internal_function
621 _dl_init_paths (const char *llp)
623 size_t idx;
624 const char *strp;
625 struct r_search_path_elem *pelem, **aelem;
626 size_t round_size;
627 #ifdef SHARED
628 struct link_map *l;
629 #endif
630 /* Initialize to please the compiler. */
631 const char *errstring = NULL;
633 /* Fill in the information about the application's RPATH and the
634 directories addressed by the LD_LIBRARY_PATH environment variable. */
636 /* Get the capabilities. */
637 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
638 &ncapstr, &max_capstrlen);
640 /* First set up the rest of the default search directory entries. */
641 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
642 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
643 if (rtld_search_dirs.dirs == NULL)
645 errstring = N_("cannot create search path array");
646 signal_error:
647 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
650 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
651 + ncapstr * sizeof (enum r_dir_status))
652 / sizeof (struct r_search_path_elem));
654 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
655 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
656 * round_size * sizeof (struct r_search_path_elem));
657 if (rtld_search_dirs.dirs[0] == NULL)
659 errstring = N_("cannot create cache for search path");
660 goto signal_error;
663 rtld_search_dirs.malloced = 0;
664 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
665 strp = system_dirs;
666 idx = 0;
670 size_t cnt;
672 *aelem++ = pelem;
674 pelem->what = "system search path";
675 pelem->where = NULL;
677 pelem->dirname = strp;
678 pelem->dirnamelen = system_dirs_len[idx];
679 strp += system_dirs_len[idx] + 1;
681 /* System paths must be absolute. */
682 assert (pelem->dirname[0] == '/');
683 for (cnt = 0; cnt < ncapstr; ++cnt)
684 pelem->status[cnt] = unknown;
686 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
688 pelem += round_size;
690 while (idx < nsystem_dirs_len);
692 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
693 *aelem = NULL;
695 #ifdef SHARED
696 /* This points to the map of the main object. */
697 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
698 if (l != NULL)
700 assert (l->l_type != lt_loaded);
702 if (l->l_info[DT_RUNPATH])
704 /* Allocate room for the search path and fill in information
705 from RUNPATH. */
706 decompose_rpath (&l->l_runpath_dirs,
707 (const void *) (D_PTR (l, l_info[DT_STRTAB])
708 + l->l_info[DT_RUNPATH]->d_un.d_val),
709 l, "RUNPATH");
711 /* The RPATH is ignored. */
712 l->l_rpath_dirs.dirs = (void *) -1;
714 else
716 l->l_runpath_dirs.dirs = (void *) -1;
718 if (l->l_info[DT_RPATH])
720 /* Allocate room for the search path and fill in information
721 from RPATH. */
722 decompose_rpath (&l->l_rpath_dirs,
723 (const void *) (D_PTR (l, l_info[DT_STRTAB])
724 + l->l_info[DT_RPATH]->d_un.d_val),
725 l, "RPATH");
726 l->l_rpath_dirs.malloced = 0;
728 else
729 l->l_rpath_dirs.dirs = (void *) -1;
732 #endif /* SHARED */
734 if (llp != NULL && *llp != '\0')
736 size_t nllp;
737 const char *cp = llp;
738 char *llp_tmp;
740 #ifdef SHARED
741 /* Expand DSTs. */
742 size_t cnt = DL_DST_COUNT (llp, 1);
743 if (__builtin_expect (cnt == 0, 1))
744 llp_tmp = strdupa (llp);
745 else
747 /* Determine the length of the substituted string. */
748 size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
750 /* Allocate the necessary memory. */
751 llp_tmp = (char *) alloca (total + 1);
752 llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
754 #else
755 llp_tmp = strdupa (llp);
756 #endif
758 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
759 elements it has. */
760 nllp = 1;
761 while (*cp)
763 if (*cp == ':' || *cp == ';')
764 ++nllp;
765 ++cp;
768 env_path_list.dirs = (struct r_search_path_elem **)
769 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
770 if (env_path_list.dirs == NULL)
772 errstring = N_("cannot create cache for search path");
773 goto signal_error;
776 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
777 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
778 NULL);
780 if (env_path_list.dirs[0] == NULL)
782 free (env_path_list.dirs);
783 env_path_list.dirs = (void *) -1;
786 env_path_list.malloced = 0;
788 else
789 env_path_list.dirs = (void *) -1;
791 /* Remember the last search directory added at startup. */
792 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
796 static void
797 __attribute__ ((noreturn, noinline))
798 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
799 const char *msg, struct r_debug *r)
801 /* The file might already be closed. */
802 if (fd != -1)
803 (void) __close (fd);
804 if (l != NULL)
806 /* Remove the stillborn object from the list and free it. */
807 assert (l->l_next == NULL);
808 if (l->l_prev == NULL)
809 /* No other module loaded. This happens only in the static library,
810 or in rtld under --verify. */
811 GL(dl_ns)[l->l_ns]._ns_loaded = NULL;
812 else
813 l->l_prev->l_next = NULL;
814 --GL(dl_ns)[l->l_ns]._ns_nloaded;
815 free (l);
817 free (realname);
819 if (r != NULL)
821 r->r_state = RT_CONSISTENT;
822 _dl_debug_state ();
825 _dl_signal_error (code, name, NULL, msg);
829 /* Map in the shared object NAME, actually located in REALNAME, and already
830 opened on FD. */
832 #ifndef EXTERNAL_MAP_FROM_FD
833 static
834 #endif
835 struct link_map *
836 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
837 char *realname, struct link_map *loader, int l_type,
838 int mode, void **stack_endp, Lmid_t nsid)
840 struct link_map *l = NULL;
841 const ElfW(Ehdr) *header;
842 const ElfW(Phdr) *phdr;
843 const ElfW(Phdr) *ph;
844 size_t maplength;
845 int type;
846 struct stat64 st;
847 /* Initialize to keep the compiler happy. */
848 const char *errstring = NULL;
849 int errval = 0;
850 struct r_debug *r = _dl_debug_initialize (0, nsid);
851 bool make_consistent = false;
853 /* Get file information. */
854 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
856 errstring = N_("cannot stat shared object");
857 call_lose_errno:
858 errval = errno;
859 call_lose:
860 lose (errval, fd, name, realname, l, errstring,
861 make_consistent ? r : NULL);
864 /* Look again to see if the real name matched another already loaded. */
865 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
866 if (l->l_removed == 0 && l->l_ino == st.st_ino && l->l_dev == st.st_dev)
868 /* The object is already loaded.
869 Just bump its reference count and return it. */
870 __close (fd);
872 /* If the name is not in the list of names for this object add
873 it. */
874 free (realname);
875 add_name_to_object (l, name);
877 return l;
880 #ifdef SHARED
881 /* When loading into a namespace other than the base one we must
882 avoid loading ld.so since there can only be one copy. Ever. */
883 if (__builtin_expect (nsid != LM_ID_BASE, 0)
884 && ((st.st_ino == GL(dl_rtld_map).l_ino
885 && st.st_dev == GL(dl_rtld_map).l_dev)
886 || _dl_name_match_p (name, &GL(dl_rtld_map))))
888 /* This is indeed ld.so. Create a new link_map which refers to
889 the real one for almost everything. */
890 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
891 if (l == NULL)
892 goto fail_new;
894 /* Refer to the real descriptor. */
895 l->l_real = &GL(dl_rtld_map);
897 /* No need to bump the refcount of the real object, ld.so will
898 never be unloaded. */
899 __close (fd);
901 return l;
903 #endif
905 if (mode & RTLD_NOLOAD)
907 /* We are not supposed to load the object unless it is already
908 loaded. So return now. */
909 __close (fd);
910 return NULL;
913 /* Print debugging message. */
914 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
915 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
917 /* This is the ELF header. We read it in `open_verify'. */
918 header = (void *) fbp->buf;
920 #ifndef MAP_ANON
921 # define MAP_ANON 0
922 if (_dl_zerofd == -1)
924 _dl_zerofd = _dl_sysdep_open_zero_fill ();
925 if (_dl_zerofd == -1)
927 __close (fd);
928 _dl_signal_error (errno, NULL, NULL,
929 N_("cannot open zero fill device"));
932 #endif
934 /* Signal that we are going to add new objects. */
935 if (r->r_state == RT_CONSISTENT)
937 #ifdef SHARED
938 /* Auditing checkpoint: we are going to add new objects. */
939 if ((mode & __RTLD_AUDIT) == 0
940 && __builtin_expect (GLRO(dl_naudit) > 0, 0))
942 struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
943 /* Do not call the functions for any auditing object. */
944 if (head->l_auditing == 0)
946 struct audit_ifaces *afct = GLRO(dl_audit);
947 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
949 if (afct->activity != NULL)
950 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
952 afct = afct->next;
956 #endif
958 /* Notify the debugger we have added some objects. We need to
959 call _dl_debug_initialize in a static program in case dynamic
960 linking has not been used before. */
961 r->r_state = RT_ADD;
962 _dl_debug_state ();
963 make_consistent = true;
965 else
966 assert (r->r_state == RT_ADD);
968 /* Enter the new object in the list of loaded objects. */
969 l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
970 if (__builtin_expect (l == NULL, 0))
972 #ifdef SHARED
973 fail_new:
974 #endif
975 errstring = N_("cannot create shared object descriptor");
976 goto call_lose_errno;
979 /* Extract the remaining details we need from the ELF header
980 and then read in the program header table. */
981 l->l_entry = header->e_entry;
982 type = header->e_type;
983 l->l_phnum = header->e_phnum;
985 maplength = header->e_phnum * sizeof (ElfW(Phdr));
986 if (header->e_phoff + maplength <= (size_t) fbp->len)
987 phdr = (void *) (fbp->buf + header->e_phoff);
988 else
990 phdr = alloca (maplength);
991 __lseek (fd, header->e_phoff, SEEK_SET);
992 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
994 errstring = N_("cannot read file data");
995 goto call_lose_errno;
999 /* Presumed absent PT_GNU_STACK. */
1000 uint_fast16_t stack_flags = PF_R|PF_W|PF_X;
1003 /* Scan the program header table, collecting its load commands. */
1004 struct loadcmd
1006 ElfW(Addr) mapstart, mapend, dataend, allocend;
1007 off_t mapoff;
1008 int prot;
1009 } loadcmds[l->l_phnum], *c;
1010 size_t nloadcmds = 0;
1011 bool has_holes = false;
1013 /* The struct is initialized to zero so this is not necessary:
1014 l->l_ld = 0;
1015 l->l_phdr = 0;
1016 l->l_addr = 0; */
1017 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
1018 switch (ph->p_type)
1020 /* These entries tell us where to find things once the file's
1021 segments are mapped in. We record the addresses it says
1022 verbatim, and later correct for the run-time load address. */
1023 case PT_DYNAMIC:
1024 l->l_ld = (void *) ph->p_vaddr;
1025 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1026 break;
1028 case PT_PHDR:
1029 l->l_phdr = (void *) ph->p_vaddr;
1030 break;
1032 case PT_LOAD:
1033 /* A load command tells us to map in part of the file.
1034 We record the load commands and process them all later. */
1035 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
1038 errstring = N_("ELF load command alignment not page-aligned");
1039 goto call_lose;
1041 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
1042 & (ph->p_align - 1)) != 0, 0))
1044 errstring
1045 = N_("ELF load command address/offset not properly aligned");
1046 goto call_lose;
1049 c = &loadcmds[nloadcmds++];
1050 c->mapstart = ph->p_vaddr & ~(GLRO(dl_pagesize) - 1);
1051 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
1052 & ~(GLRO(dl_pagesize) - 1));
1053 c->dataend = ph->p_vaddr + ph->p_filesz;
1054 c->allocend = ph->p_vaddr + ph->p_memsz;
1055 c->mapoff = ph->p_offset & ~(GLRO(dl_pagesize) - 1);
1057 /* Determine whether there is a gap between the last segment
1058 and this one. */
1059 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
1060 has_holes = true;
1062 /* Optimize a common case. */
1063 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1064 c->prot = (PF_TO_PROT
1065 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
1066 #else
1067 c->prot = 0;
1068 if (ph->p_flags & PF_R)
1069 c->prot |= PROT_READ;
1070 if (ph->p_flags & PF_W)
1071 c->prot |= PROT_WRITE;
1072 if (ph->p_flags & PF_X)
1073 c->prot |= PROT_EXEC;
1074 #endif
1075 break;
1077 case PT_TLS:
1078 if (ph->p_memsz == 0)
1079 /* Nothing to do for an empty segment. */
1080 break;
1082 l->l_tls_blocksize = ph->p_memsz;
1083 l->l_tls_align = ph->p_align;
1084 if (ph->p_align == 0)
1085 l->l_tls_firstbyte_offset = 0;
1086 else
1087 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1088 l->l_tls_initimage_size = ph->p_filesz;
1089 /* Since we don't know the load address yet only store the
1090 offset. We will adjust it later. */
1091 l->l_tls_initimage = (void *) ph->p_vaddr;
1093 /* If not loading the initial set of shared libraries,
1094 check whether we should permit loading a TLS segment. */
1095 if (__builtin_expect (l->l_type == lt_library, 1)
1096 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1097 not set up TLS data structures, so don't use them now. */
1098 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1100 /* Assign the next available module ID. */
1101 l->l_tls_modid = _dl_next_tls_modid ();
1102 break;
1105 #ifdef SHARED
1106 if (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0)
1107 /* We are loading the executable itself when the dynamic linker
1108 was executed directly. The setup will happen later. */
1109 break;
1111 /* In a static binary there is no way to tell if we dynamically
1112 loaded libpthread. */
1113 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1114 #endif
1116 /* We have not yet loaded libpthread.
1117 We can do the TLS setup right now! */
1119 void *tcb;
1121 /* The first call allocates TLS bookkeeping data structures.
1122 Then we allocate the TCB for the initial thread. */
1123 if (__builtin_expect (_dl_tls_setup (), 0)
1124 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1127 errval = ENOMEM;
1128 errstring = N_("\
1129 cannot allocate TLS data structures for initial thread");
1130 goto call_lose;
1133 /* Now we install the TCB in the thread register. */
1134 errstring = TLS_INIT_TP (tcb, 0);
1135 if (__builtin_expect (errstring == NULL, 1))
1137 /* Now we are all good. */
1138 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1139 break;
1142 /* The kernel is too old or somesuch. */
1143 errval = 0;
1144 _dl_deallocate_tls (tcb, 1);
1145 goto call_lose;
1148 /* Uh-oh, the binary expects TLS support but we cannot
1149 provide it. */
1150 errval = 0;
1151 errstring = N_("cannot handle TLS data");
1152 goto call_lose;
1153 break;
1155 case PT_GNU_STACK:
1156 stack_flags = ph->p_flags;
1157 break;
1159 case PT_GNU_RELRO:
1160 l->l_relro_addr = ph->p_vaddr;
1161 l->l_relro_size = ph->p_memsz;
1162 break;
1165 if (__builtin_expect (nloadcmds == 0, 0))
1167 /* This only happens for a bogus object that will be caught with
1168 another error below. But we don't want to go through the
1169 calculations below using NLOADCMDS - 1. */
1170 errstring = N_("object file has no loadable segments");
1171 goto call_lose;
1174 /* Now process the load commands and map segments into memory. */
1175 c = loadcmds;
1177 /* Length of the sections to be loaded. */
1178 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1180 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1182 /* This is a position-independent shared object. We can let the
1183 kernel map it anywhere it likes, but we must have space for all
1184 the segments in their specified positions relative to the first.
1185 So we map the first segment without MAP_FIXED, but with its
1186 extent increased to cover all the segments. Then we remove
1187 access from excess portion, and there is known sufficient space
1188 there to remap from the later segments.
1190 As a refinement, sometimes we have an address that we would
1191 prefer to map such objects at; but this is only a preference,
1192 the OS can do whatever it likes. */
1193 ElfW(Addr) mappref;
1194 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1195 c->mapstart & GLRO(dl_use_load_bias))
1196 - MAP_BASE_ADDR (l));
1198 /* Remember which part of the address space this object uses. */
1199 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1200 c->prot,
1201 MAP_COPY|MAP_FILE,
1202 fd, c->mapoff);
1203 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1205 map_error:
1206 errstring = N_("failed to map segment from shared object");
1207 goto call_lose_errno;
1210 l->l_map_end = l->l_map_start + maplength;
1211 l->l_addr = l->l_map_start - c->mapstart;
1213 if (has_holes)
1214 /* Change protection on the excess portion to disallow all access;
1215 the portions we do not remap later will be inaccessible as if
1216 unallocated. Then jump into the normal segment-mapping loop to
1217 handle the portion of the segment past the end of the file
1218 mapping. */
1219 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1220 loadcmds[nloadcmds - 1].mapstart - c->mapend,
1221 PROT_NONE);
1223 l->l_contiguous = 1;
1225 goto postmap;
1228 /* This object is loaded at a fixed address. This must never
1229 happen for objects loaded with dlopen(). */
1230 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1232 errstring = N_("cannot dynamically load executable");
1233 goto call_lose;
1236 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1237 fixed. */
1238 ELF_FIXED_ADDRESS (loader, c->mapstart);
1241 /* Remember which part of the address space this object uses. */
1242 l->l_map_start = c->mapstart + l->l_addr;
1243 l->l_map_end = l->l_map_start + maplength;
1244 l->l_contiguous = !has_holes;
1246 while (c < &loadcmds[nloadcmds])
1248 if (c->mapend > c->mapstart
1249 /* Map the segment contents from the file. */
1250 && (__mmap ((void *) (l->l_addr + c->mapstart),
1251 c->mapend - c->mapstart, c->prot,
1252 MAP_FIXED|MAP_COPY|MAP_FILE,
1253 fd, c->mapoff)
1254 == MAP_FAILED))
1255 goto map_error;
1257 postmap:
1258 if (c->prot & PROT_EXEC)
1259 l->l_text_end = l->l_addr + c->mapend;
1261 if (l->l_phdr == 0
1262 && (ElfW(Off)) c->mapoff <= header->e_phoff
1263 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1264 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1265 /* Found the program header in this segment. */
1266 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1268 if (c->allocend > c->dataend)
1270 /* Extra zero pages should appear at the end of this segment,
1271 after the data mapped from the file. */
1272 ElfW(Addr) zero, zeroend, zeropage;
1274 zero = l->l_addr + c->dataend;
1275 zeroend = l->l_addr + c->allocend;
1276 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1277 & ~(GLRO(dl_pagesize) - 1));
1279 if (zeroend < zeropage)
1280 /* All the extra data is in the last page of the segment.
1281 We can just zero it. */
1282 zeropage = zeroend;
1284 if (zeropage > zero)
1286 /* Zero the final part of the last page of the segment. */
1287 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1289 /* Dag nab it. */
1290 if (__mprotect ((caddr_t) (zero
1291 & ~(GLRO(dl_pagesize) - 1)),
1292 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1294 errstring = N_("cannot change memory protections");
1295 goto call_lose_errno;
1298 memset ((void *) zero, '\0', zeropage - zero);
1299 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1300 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1301 GLRO(dl_pagesize), c->prot);
1304 if (zeroend > zeropage)
1306 /* Map the remaining zero pages in from the zero fill FD. */
1307 caddr_t mapat;
1308 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1309 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1310 -1, 0);
1311 if (__builtin_expect (mapat == MAP_FAILED, 0))
1313 errstring = N_("cannot map zero-fill pages");
1314 goto call_lose_errno;
1319 ++c;
1323 if (l->l_ld == 0)
1325 if (__builtin_expect (type == ET_DYN, 0))
1327 errstring = N_("object file has no dynamic section");
1328 goto call_lose;
1331 else
1332 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1334 elf_get_dynamic_info (l, NULL);
1336 /* Make sure we are not dlopen'ing an object that has the
1337 DF_1_NOOPEN flag set. */
1338 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1339 && (mode & __RTLD_DLOPEN))
1341 /* We are not supposed to load this object. Free all resources. */
1342 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1344 if (!l->l_libname->dont_free)
1345 free (l->l_libname);
1347 if (l->l_phdr_allocated)
1348 free ((void *) l->l_phdr);
1350 errstring = N_("shared object cannot be dlopen()ed");
1351 goto call_lose;
1354 if (l->l_phdr == NULL)
1356 /* The program header is not contained in any of the segments.
1357 We have to allocate memory ourself and copy it over from out
1358 temporary place. */
1359 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1360 * sizeof (ElfW(Phdr)));
1361 if (newp == NULL)
1363 errstring = N_("cannot allocate memory for program header");
1364 goto call_lose_errno;
1367 l->l_phdr = memcpy (newp, phdr,
1368 (header->e_phnum * sizeof (ElfW(Phdr))));
1369 l->l_phdr_allocated = 1;
1371 else
1372 /* Adjust the PT_PHDR value by the runtime load address. */
1373 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1375 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1377 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso),
1378 0) != 0)
1380 errstring = N_("invalid caller");
1381 goto call_lose;
1384 /* The stack is presently not executable, but this module
1385 requires that it be executable. We must change the
1386 protection of the variable which contains the flags used in
1387 the mprotect calls. */
1388 #ifdef SHARED
1389 if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
1391 const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
1392 const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
1394 struct link_map *const m = &GL(dl_rtld_map);
1395 const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
1396 + m->l_relro_size)
1397 & -GLRO(dl_pagesize));
1398 if (__builtin_expect (p + s <= relro_end, 1))
1400 /* The variable lies in the region protected by RELRO. */
1401 __mprotect ((void *) p, s, PROT_READ|PROT_WRITE);
1402 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1403 __mprotect ((void *) p, s, PROT_READ);
1405 else
1406 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1408 else
1409 #endif
1410 __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
1412 #ifdef check_consistency
1413 check_consistency ();
1414 #endif
1416 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1417 if (errval)
1419 errstring = N_("\
1420 cannot enable executable stack as shared object requires");
1421 goto call_lose;
1425 /* Adjust the address of the TLS initialization image. */
1426 if (l->l_tls_initimage != NULL)
1427 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1429 /* We are done mapping in the file. We no longer need the descriptor. */
1430 if (__builtin_expect (__close (fd) != 0, 0))
1432 errstring = N_("cannot close file descriptor");
1433 goto call_lose_errno;
1435 /* Signal that we closed the file. */
1436 fd = -1;
1438 if (l->l_type == lt_library && type == ET_EXEC)
1439 l->l_type = lt_executable;
1441 l->l_entry += l->l_addr;
1443 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1444 _dl_debug_printf ("\
1445 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1446 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1447 (int) sizeof (void *) * 2,
1448 (unsigned long int) l->l_ld,
1449 (int) sizeof (void *) * 2,
1450 (unsigned long int) l->l_addr,
1451 (int) sizeof (void *) * 2, maplength,
1452 (int) sizeof (void *) * 2,
1453 (unsigned long int) l->l_entry,
1454 (int) sizeof (void *) * 2,
1455 (unsigned long int) l->l_phdr,
1456 (int) sizeof (void *) * 2, l->l_phnum);
1458 /* Set up the symbol hash table. */
1459 _dl_setup_hash (l);
1461 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1462 have to do this for the main map. */
1463 if ((mode & RTLD_DEEPBIND) == 0
1464 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1465 && &l->l_searchlist != l->l_scope[0])
1467 /* Create an appropriate searchlist. It contains only this map.
1468 This is the definition of DT_SYMBOLIC in SysVr4. */
1469 l->l_symbolic_searchlist.r_list[0] = l;
1470 l->l_symbolic_searchlist.r_nlist = 1;
1472 /* Now move the existing entries one back. */
1473 memmove (&l->l_scope[1], &l->l_scope[0],
1474 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1476 /* Now add the new entry. */
1477 l->l_scope[0] = &l->l_symbolic_searchlist;
1480 /* Remember whether this object must be initialized first. */
1481 if (l->l_flags_1 & DF_1_INITFIRST)
1482 GL(dl_initfirst) = l;
1484 /* Finally the file information. */
1485 l->l_dev = st.st_dev;
1486 l->l_ino = st.st_ino;
1488 /* When we profile the SONAME might be needed for something else but
1489 loading. Add it right away. */
1490 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1491 && l->l_info[DT_SONAME] != NULL)
1492 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1493 + l->l_info[DT_SONAME]->d_un.d_val));
1495 #ifdef SHARED
1496 /* Auditing checkpoint: we have a new object. */
1497 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
1498 && !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
1500 struct audit_ifaces *afct = GLRO(dl_audit);
1501 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1503 if (afct->objopen != NULL)
1505 l->l_audit[cnt].bindflags
1506 = afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
1508 l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
1511 afct = afct->next;
1514 #endif
1516 return l;
1519 /* Print search path. */
1520 static void
1521 print_search_path (struct r_search_path_elem **list,
1522 const char *what, const char *name)
1524 char buf[max_dirnamelen + max_capstrlen];
1525 int first = 1;
1527 _dl_debug_printf (" search path=");
1529 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1531 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1532 size_t cnt;
1534 for (cnt = 0; cnt < ncapstr; ++cnt)
1535 if ((*list)->status[cnt] != nonexisting)
1537 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1538 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1539 cp[0] = '\0';
1540 else
1541 cp[-1] = '\0';
1543 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1544 first = 0;
1547 ++list;
1550 if (name != NULL)
1551 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1552 name[0] ? name : rtld_progname);
1553 else
1554 _dl_debug_printf_c ("\t\t(%s)\n", what);
1557 /* Open a file and verify it is an ELF file for this architecture. We
1558 ignore only ELF files for other architectures. Non-ELF files and
1559 ELF files with different header information cause fatal errors since
1560 this could mean there is something wrong in the installation and the
1561 user might want to know about this. */
1562 static int
1563 open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
1564 int whatcode, bool *found_other_class, bool free_name)
1566 /* This is the expected ELF header. */
1567 #define ELF32_CLASS ELFCLASS32
1568 #define ELF64_CLASS ELFCLASS64
1569 #ifndef VALID_ELF_HEADER
1570 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1571 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1572 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1573 #elif defined MORE_ELF_HEADER_DATA
1574 MORE_ELF_HEADER_DATA;
1575 #endif
1576 static const unsigned char expected[EI_NIDENT] =
1578 [EI_MAG0] = ELFMAG0,
1579 [EI_MAG1] = ELFMAG1,
1580 [EI_MAG2] = ELFMAG2,
1581 [EI_MAG3] = ELFMAG3,
1582 [EI_CLASS] = ELFW(CLASS),
1583 [EI_DATA] = byteorder,
1584 [EI_VERSION] = EV_CURRENT,
1585 [EI_OSABI] = ELFOSABI_SYSV,
1586 [EI_ABIVERSION] = 0
1588 static const struct
1590 ElfW(Word) vendorlen;
1591 ElfW(Word) datalen;
1592 ElfW(Word) type;
1593 char vendor[4];
1594 } expected_note = { 4, 16, 1, "GNU" };
1595 /* Initialize it to make the compiler happy. */
1596 const char *errstring = NULL;
1597 int errval = 0;
1599 #ifdef SHARED
1600 /* Give the auditing libraries a chance. */
1601 if (__builtin_expect (GLRO(dl_naudit) > 0, 0) && whatcode != 0
1602 && loader->l_auditing == 0)
1604 struct audit_ifaces *afct = GLRO(dl_audit);
1605 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1607 if (afct->objsearch != NULL)
1609 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
1610 whatcode);
1611 if (name == NULL)
1612 /* Ignore the path. */
1613 return -1;
1616 afct = afct->next;
1619 #endif
1621 /* Open the file. We always open files read-only. */
1622 int fd = __open (name, O_RDONLY);
1623 if (fd != -1)
1625 ElfW(Ehdr) *ehdr;
1626 ElfW(Phdr) *phdr, *ph;
1627 ElfW(Word) *abi_note;
1628 unsigned int osversion;
1629 size_t maplength;
1631 /* We successfully openened the file. Now verify it is a file
1632 we can use. */
1633 __set_errno (0);
1634 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1636 /* This is where the ELF header is loaded. */
1637 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1638 ehdr = (ElfW(Ehdr) *) fbp->buf;
1640 /* Now run the tests. */
1641 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1643 errval = errno;
1644 errstring = (errval == 0
1645 ? N_("file too short") : N_("cannot read file data"));
1646 call_lose:
1647 if (free_name)
1649 char *realname = (char *) name;
1650 name = strdupa (realname);
1651 free (realname);
1653 lose (errval, fd, name, NULL, NULL, errstring, NULL);
1656 /* See whether the ELF header is what we expect. */
1657 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1658 EI_ABIVERSION)
1659 || !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1660 ehdr->e_ident[EI_ABIVERSION])
1661 || memcmp (&ehdr->e_ident[EI_PAD],
1662 &expected[EI_PAD],
1663 EI_NIDENT - EI_PAD) != 0,
1666 /* Something is wrong. */
1667 const Elf32_Word *magp = (const void *) ehdr->e_ident;
1668 if (*magp !=
1669 #if BYTE_ORDER == LITTLE_ENDIAN
1670 ((ELFMAG0 << (EI_MAG0 * 8)) |
1671 (ELFMAG1 << (EI_MAG1 * 8)) |
1672 (ELFMAG2 << (EI_MAG2 * 8)) |
1673 (ELFMAG3 << (EI_MAG3 * 8)))
1674 #else
1675 ((ELFMAG0 << (EI_MAG3 * 8)) |
1676 (ELFMAG1 << (EI_MAG2 * 8)) |
1677 (ELFMAG2 << (EI_MAG1 * 8)) |
1678 (ELFMAG3 << (EI_MAG0 * 8)))
1679 #endif
1681 errstring = N_("invalid ELF header");
1682 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1684 /* This is not a fatal error. On architectures where
1685 32-bit and 64-bit binaries can be run this might
1686 happen. */
1687 *found_other_class = true;
1688 goto close_and_out;
1690 else if (ehdr->e_ident[EI_DATA] != byteorder)
1692 if (BYTE_ORDER == BIG_ENDIAN)
1693 errstring = N_("ELF file data encoding not big-endian");
1694 else
1695 errstring = N_("ELF file data encoding not little-endian");
1697 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1698 errstring
1699 = N_("ELF file version ident does not match current one");
1700 /* XXX We should be able so set system specific versions which are
1701 allowed here. */
1702 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1703 errstring = N_("ELF file OS ABI invalid");
1704 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
1705 ehdr->e_ident[EI_ABIVERSION]))
1706 errstring = N_("ELF file ABI version invalid");
1707 else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
1708 EI_NIDENT - EI_PAD) != 0)
1709 errstring = N_("nonzero padding in e_ident");
1710 else
1711 /* Otherwise we don't know what went wrong. */
1712 errstring = N_("internal error");
1714 goto call_lose;
1717 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1719 errstring = N_("ELF file version does not match current one");
1720 goto call_lose;
1722 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1723 goto close_and_out;
1724 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1725 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1727 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1728 goto call_lose;
1730 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1731 != sizeof (ElfW(Phdr)))
1733 errstring = N_("ELF file's phentsize not the expected size");
1734 goto call_lose;
1737 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1738 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1739 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1740 else
1742 phdr = alloca (maplength);
1743 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1744 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1746 read_error:
1747 errval = errno;
1748 errstring = N_("cannot read file data");
1749 goto call_lose;
1753 /* Check .note.ABI-tag if present. */
1754 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1755 if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
1757 ElfW(Addr) size = ph->p_filesz;
1759 if (ph->p_offset + size <= (size_t) fbp->len)
1760 abi_note = (void *) (fbp->buf + ph->p_offset);
1761 else
1763 abi_note = alloca (size);
1764 __lseek (fd, ph->p_offset, SEEK_SET);
1765 if (__libc_read (fd, (void *) abi_note, size) != size)
1766 goto read_error;
1769 while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1771 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1772 ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
1773 + ROUND (abi_note[0])
1774 + ROUND (abi_note[1]);
1776 if (size - 32 < note_size)
1778 size = 0;
1779 break;
1781 size -= note_size;
1782 abi_note = (void *) abi_note + note_size;
1785 if (size == 0)
1786 continue;
1788 osversion = (abi_note[5] & 0xff) * 65536
1789 + (abi_note[6] & 0xff) * 256
1790 + (abi_note[7] & 0xff);
1791 if (abi_note[4] != __ABI_TAG_OS
1792 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1794 close_and_out:
1795 __close (fd);
1796 __set_errno (ENOENT);
1797 fd = -1;
1800 break;
1804 return fd;
1807 /* Try to open NAME in one of the directories in *DIRSP.
1808 Return the fd, or -1. If successful, fill in *REALNAME
1809 with the malloc'd full directory name. If it turns out
1810 that none of the directories in *DIRSP exists, *DIRSP is
1811 replaced with (void *) -1, and the old value is free()d
1812 if MAY_FREE_DIRS is true. */
1814 static int
1815 open_path (const char *name, size_t namelen, int preloaded,
1816 struct r_search_path_struct *sps, char **realname,
1817 struct filebuf *fbp, struct link_map *loader, int whatcode,
1818 bool *found_other_class)
1820 struct r_search_path_elem **dirs = sps->dirs;
1821 char *buf;
1822 int fd = -1;
1823 const char *current_what = NULL;
1824 int any = 0;
1826 if (__builtin_expect (dirs == NULL, 0))
1827 /* We're called before _dl_init_paths when loading the main executable
1828 given on the command line when rtld is run directly. */
1829 return -1;
1831 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1834 struct r_search_path_elem *this_dir = *dirs;
1835 size_t buflen = 0;
1836 size_t cnt;
1837 char *edp;
1838 int here_any = 0;
1839 int err;
1841 /* If we are debugging the search for libraries print the path
1842 now if it hasn't happened now. */
1843 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1844 && current_what != this_dir->what)
1846 current_what = this_dir->what;
1847 print_search_path (dirs, current_what, this_dir->where);
1850 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1851 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1853 /* Skip this directory if we know it does not exist. */
1854 if (this_dir->status[cnt] == nonexisting)
1855 continue;
1857 buflen =
1858 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1859 capstr[cnt].len),
1860 name, namelen)
1861 - buf);
1863 /* Print name we try if this is wanted. */
1864 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1865 _dl_debug_printf (" trying file=%s\n", buf);
1867 fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
1868 false);
1869 if (this_dir->status[cnt] == unknown)
1871 if (fd != -1)
1872 this_dir->status[cnt] = existing;
1873 /* Do not update the directory information when loading
1874 auditing code. We must try to disturb the program as
1875 little as possible. */
1876 else if (loader == NULL
1877 || GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
1879 /* We failed to open machine dependent library. Let's
1880 test whether there is any directory at all. */
1881 struct stat64 st;
1883 buf[buflen - namelen - 1] = '\0';
1885 if (__xstat64 (_STAT_VER, buf, &st) != 0
1886 || ! S_ISDIR (st.st_mode))
1887 /* The directory does not exist or it is no directory. */
1888 this_dir->status[cnt] = nonexisting;
1889 else
1890 this_dir->status[cnt] = existing;
1894 /* Remember whether we found any existing directory. */
1895 here_any |= this_dir->status[cnt] != nonexisting;
1897 if (fd != -1 && __builtin_expect (preloaded, 0)
1898 && INTUSE(__libc_enable_secure))
1900 /* This is an extra security effort to make sure nobody can
1901 preload broken shared objects which are in the trusted
1902 directories and so exploit the bugs. */
1903 struct stat64 st;
1905 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1906 || (st.st_mode & S_ISUID) == 0)
1908 /* The shared object cannot be tested for being SUID
1909 or this bit is not set. In this case we must not
1910 use this object. */
1911 __close (fd);
1912 fd = -1;
1913 /* We simply ignore the file, signal this by setting
1914 the error value which would have been set by `open'. */
1915 errno = ENOENT;
1920 if (fd != -1)
1922 *realname = (char *) malloc (buflen);
1923 if (*realname != NULL)
1925 memcpy (*realname, buf, buflen);
1926 return fd;
1928 else
1930 /* No memory for the name, we certainly won't be able
1931 to load and link it. */
1932 __close (fd);
1933 return -1;
1936 if (here_any && (err = errno) != ENOENT && err != EACCES)
1937 /* The file exists and is readable, but something went wrong. */
1938 return -1;
1940 /* Remember whether we found anything. */
1941 any |= here_any;
1943 while (*++dirs != NULL);
1945 /* Remove the whole path if none of the directories exists. */
1946 if (__builtin_expect (! any, 0))
1948 /* Paths which were allocated using the minimal malloc() in ld.so
1949 must not be freed using the general free() in libc. */
1950 if (sps->malloced)
1951 free (sps->dirs);
1953 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1954 into it. */
1955 if (sps != &rtld_search_dirs)
1956 sps->dirs = (void *) -1;
1959 return -1;
1962 /* Map in the shared object file NAME. */
1964 struct link_map *
1965 internal_function
1966 _dl_map_object (struct link_map *loader, const char *name, int preloaded,
1967 int type, int trace_mode, int mode, Lmid_t nsid)
1969 int fd;
1970 char *realname;
1971 char *name_copy;
1972 struct link_map *l;
1973 struct filebuf fb;
1975 assert (nsid >= 0);
1976 assert (nsid < GL(dl_nns));
1978 /* Look for this name among those already loaded. */
1979 for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
1981 /* If the requested name matches the soname of a loaded object,
1982 use that object. Elide this check for names that have not
1983 yet been opened. */
1984 if (__builtin_expect (l->l_faked, 0) != 0
1985 || __builtin_expect (l->l_removed, 0) != 0)
1986 continue;
1987 if (!_dl_name_match_p (name, l))
1989 const char *soname;
1991 if (__builtin_expect (l->l_soname_added, 1)
1992 || l->l_info[DT_SONAME] == NULL)
1993 continue;
1995 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1996 + l->l_info[DT_SONAME]->d_un.d_val);
1997 if (strcmp (name, soname) != 0)
1998 continue;
2000 /* We have a match on a new name -- cache it. */
2001 add_name_to_object (l, soname);
2002 l->l_soname_added = 1;
2005 /* We have a match. */
2006 return l;
2009 /* Display information if we are debugging. */
2010 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
2011 && loader != NULL)
2012 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name, nsid,
2013 loader->l_name[0]
2014 ? loader->l_name : rtld_progname, loader->l_ns);
2016 #ifdef SHARED
2017 /* Give the auditing libraries a chance to change the name before we
2018 try anything. */
2019 if (__builtin_expect (GLRO(dl_naudit) > 0, 0)
2020 && (loader == NULL || loader->l_auditing == 0))
2022 struct audit_ifaces *afct = GLRO(dl_audit);
2023 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2025 if (afct->objsearch != NULL)
2027 name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
2028 LA_SER_ORIG);
2029 if (name == NULL)
2031 /* Do not try anything further. */
2032 fd = -1;
2033 goto no_file;
2037 afct = afct->next;
2040 #endif
2042 /* Will be true if we found a DSO which is of the other ELF class. */
2043 bool found_other_class = false;
2045 if (strchr (name, '/') == NULL)
2047 /* Search for NAME in several places. */
2049 size_t namelen = strlen (name) + 1;
2051 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2052 _dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
2054 fd = -1;
2056 /* When the object has the RUNPATH information we don't use any
2057 RPATHs. */
2058 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
2060 /* This is the executable's map (if there is one). Make sure that
2061 we do not look at it twice. */
2062 struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2063 bool did_main_map = false;
2065 /* First try the DT_RPATH of the dependent object that caused NAME
2066 to be loaded. Then that object's dependent, and on up. */
2067 for (l = loader; l; l = l->l_loader)
2068 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2070 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
2071 &realname, &fb, loader, LA_SER_RUNPATH,
2072 &found_other_class);
2073 if (fd != -1)
2074 break;
2076 did_main_map |= l == main_map;
2079 /* If dynamically linked, try the DT_RPATH of the executable
2080 itself. NB: we do this for lookups in any namespace. */
2081 if (fd == -1 && !did_main_map
2082 && main_map != NULL && main_map->l_type != lt_loaded
2083 && cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
2084 "RPATH"))
2085 fd = open_path (name, namelen, preloaded, &main_map->l_rpath_dirs,
2086 &realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
2087 &found_other_class);
2090 /* Try the LD_LIBRARY_PATH environment variable. */
2091 if (fd == -1 && env_path_list.dirs != (void *) -1)
2092 fd = open_path (name, namelen, preloaded, &env_path_list,
2093 &realname, &fb,
2094 loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
2095 LA_SER_LIBPATH, &found_other_class);
2097 /* Look at the RUNPATH information for this binary. */
2098 if (fd == -1 && loader != NULL
2099 && cache_rpath (loader, &loader->l_runpath_dirs,
2100 DT_RUNPATH, "RUNPATH"))
2101 fd = open_path (name, namelen, preloaded,
2102 &loader->l_runpath_dirs, &realname, &fb, loader,
2103 LA_SER_RUNPATH, &found_other_class);
2105 if (fd == -1
2106 && (__builtin_expect (! preloaded, 1)
2107 || ! INTUSE(__libc_enable_secure)))
2109 /* Check the list of libraries in the file /etc/ld.so.cache,
2110 for compatibility with Linux's ldconfig program. */
2111 const char *cached = _dl_load_cache_lookup (name);
2113 if (cached != NULL)
2115 #ifdef SHARED
2116 // XXX Correct to unconditionally default to namespace 0?
2117 l = loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2118 #else
2119 l = loader;
2120 #endif
2122 /* If the loader has the DF_1_NODEFLIB flag set we must not
2123 use a cache entry from any of these directories. */
2124 if (
2125 #ifndef SHARED
2126 /* 'l' is always != NULL for dynamically linked objects. */
2127 l != NULL &&
2128 #endif
2129 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
2131 const char *dirp = system_dirs;
2132 unsigned int cnt = 0;
2136 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
2138 /* The prefix matches. Don't use the entry. */
2139 cached = NULL;
2140 break;
2143 dirp += system_dirs_len[cnt] + 1;
2144 ++cnt;
2146 while (cnt < nsystem_dirs_len);
2149 if (cached != NULL)
2151 fd = open_verify (cached,
2152 &fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
2153 LA_SER_CONFIG, &found_other_class, false);
2154 if (__builtin_expect (fd != -1, 1))
2156 realname = local_strdup (cached);
2157 if (realname == NULL)
2159 __close (fd);
2160 fd = -1;
2167 /* Finally, try the default path. */
2168 if (fd == -1
2169 && ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
2170 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
2171 && rtld_search_dirs.dirs != (void *) -1)
2172 fd = open_path (name, namelen, preloaded, &rtld_search_dirs,
2173 &realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
2175 /* Add another newline when we are tracing the library loading. */
2176 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2177 _dl_debug_printf ("\n");
2179 else
2181 /* The path may contain dynamic string tokens. */
2182 realname = (loader
2183 ? expand_dynamic_string_token (loader, name)
2184 : local_strdup (name));
2185 if (realname == NULL)
2186 fd = -1;
2187 else
2189 fd = open_verify (realname, &fb,
2190 loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
2191 &found_other_class, true);
2192 if (__builtin_expect (fd, 0) == -1)
2193 free (realname);
2197 #ifdef SHARED
2198 no_file:
2199 #endif
2200 /* In case the LOADER information has only been provided to get to
2201 the appropriate RUNPATH/RPATH information we do not need it
2202 anymore. */
2203 if (mode & __RTLD_CALLMAP)
2204 loader = NULL;
2206 if (__builtin_expect (fd, 0) == -1)
2208 if (trace_mode
2209 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
2211 /* We haven't found an appropriate library. But since we
2212 are only interested in the list of libraries this isn't
2213 so severe. Fake an entry with all the information we
2214 have. */
2215 static const Elf_Symndx dummy_bucket = STN_UNDEF;
2217 /* Enter the new object in the list of loaded objects. */
2218 if ((name_copy = local_strdup (name)) == NULL
2219 || (l = _dl_new_object (name_copy, name, type, loader,
2220 mode, nsid)) == NULL)
2222 free (name_copy);
2223 _dl_signal_error (ENOMEM, name, NULL,
2224 N_("cannot create shared object descriptor"));
2226 /* Signal that this is a faked entry. */
2227 l->l_faked = 1;
2228 /* Since the descriptor is initialized with zero we do not
2229 have do this here.
2230 l->l_reserved = 0; */
2231 l->l_buckets = &dummy_bucket;
2232 l->l_nbuckets = 1;
2233 l->l_relocated = 1;
2235 return l;
2237 else if (found_other_class)
2238 _dl_signal_error (0, name, NULL,
2239 ELFW(CLASS) == ELFCLASS32
2240 ? N_("wrong ELF class: ELFCLASS64")
2241 : N_("wrong ELF class: ELFCLASS32"));
2242 else
2243 _dl_signal_error (errno, name, NULL,
2244 N_("cannot open shared object file"));
2247 void *stack_end = __libc_stack_end;
2248 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
2249 &stack_end, nsid);
2253 void
2254 internal_function
2255 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
2257 if (counting)
2259 si->dls_cnt = 0;
2260 si->dls_size = 0;
2263 unsigned int idx = 0;
2264 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2265 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2266 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2268 if (sps->dirs != (void *) -1)
2270 struct r_search_path_elem **dirs = sps->dirs;
2273 const struct r_search_path_elem *const r = *dirs++;
2274 if (counting)
2276 si->dls_cnt++;
2277 si->dls_size += MAX (2, r->dirnamelen);
2279 else
2281 Dl_serpath *const sp = &si->dls_serpath[idx++];
2282 sp->dls_name = allocptr;
2283 if (r->dirnamelen < 2)
2284 *allocptr++ = r->dirnamelen ? '/' : '.';
2285 else
2286 allocptr = __mempcpy (allocptr,
2287 r->dirname, r->dirnamelen - 1);
2288 *allocptr++ = '\0';
2289 sp->dls_flags = flags;
2292 while (*dirs != NULL);
2296 /* When the object has the RUNPATH information we don't use any RPATHs. */
2297 if (loader->l_info[DT_RUNPATH] == NULL)
2299 /* First try the DT_RPATH of the dependent object that caused NAME
2300 to be loaded. Then that object's dependent, and on up. */
2302 struct link_map *l = loader;
2305 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2306 add_path (&l->l_rpath_dirs, XXX_RPATH);
2307 l = l->l_loader;
2309 while (l != NULL);
2311 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2312 if (loader->l_ns == LM_ID_BASE)
2314 l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2315 if (l != NULL && l->l_type != lt_loaded && l != loader)
2316 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2317 add_path (&l->l_rpath_dirs, XXX_RPATH);
2321 /* Try the LD_LIBRARY_PATH environment variable. */
2322 add_path (&env_path_list, XXX_ENV);
2324 /* Look at the RUNPATH information for this binary. */
2325 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2326 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2328 /* XXX
2329 Here is where ld.so.cache gets checked, but we don't have
2330 a way to indicate that in the results for Dl_serinfo. */
2332 /* Finally, try the default path. */
2333 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2334 add_path (&rtld_search_dirs, XXX_default);
2336 if (counting)
2337 /* Count the struct size before the string area, which we didn't
2338 know before we completed dls_cnt. */
2339 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;