Update.
[glibc.git] / elf / dl-load.c
blob15fff3c5e1f7317f186d61eac3a014953d8c214e
1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004 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 <dl-osinfo.h>
37 #include <stackinfo.h>
38 #include <caller.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. */
54 #ifndef MAP_COPY
55 # define MAP_COPY MAP_PRIVATE
56 #endif
58 /* We want to prevent people from modifying DSOs which are currently in
59 use. This is what MAP_DENYWRITE is for. */
60 #ifndef MAP_DENYWRITE
61 # define MAP_DENYWRITE 0
62 #endif
64 /* Some systems link their relocatable objects for another base address
65 than 0. We want to know the base address for these such that we can
66 subtract this address from the segment addresses during mapping.
67 This results in a more efficient address space usage. Defaults to
68 zero for almost all systems. */
69 #ifndef MAP_BASE_ADDR
70 # define MAP_BASE_ADDR(l) 0
71 #endif
74 #include <endian.h>
75 #if BYTE_ORDER == BIG_ENDIAN
76 # define byteorder ELFDATA2MSB
77 #elif BYTE_ORDER == LITTLE_ENDIAN
78 # define byteorder ELFDATA2LSB
79 #else
80 # error "Unknown BYTE_ORDER " BYTE_ORDER
81 # define byteorder ELFDATANONE
82 #endif
84 #define STRING(x) __STRING (x)
86 #ifdef MAP_ANON
87 /* The fd is not examined when using MAP_ANON. */
88 # define ANONFD -1
89 #else
90 int _dl_zerofd = -1;
91 # define ANONFD _dl_zerofd
92 #endif
94 /* Handle situations where we have a preferred location in memory for
95 the shared objects. */
96 #ifdef ELF_PREFERRED_ADDRESS_DATA
97 ELF_PREFERRED_ADDRESS_DATA;
98 #endif
99 #ifndef ELF_PREFERRED_ADDRESS
100 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
101 #endif
102 #ifndef ELF_FIXED_ADDRESS
103 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
104 #endif
107 int __stack_prot attribute_hidden attribute_relro
108 = (PROT_READ|PROT_WRITE
109 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
110 |PROT_GROWSDOWN
111 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
112 |PROT_GROWSUP
113 #endif
117 /* Type for the buffer we put the ELF header and hopefully the program
118 header. This buffer does not really have to be too large. In most
119 cases the program header follows the ELF header directly. If this
120 is not the case all bets are off and we can make the header
121 arbitrarily large and still won't get it read. This means the only
122 question is how large are the ELF and program header combined. The
123 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
124 bytes long. Each program header entry is again 32 and 56 bytes
125 long respectively. I.e., even with a file which has 7 program
126 header entries we only have to read 512B. Add to this a bit of
127 margin for program notes and reading 512B and 640B for 32-bit and
128 64-bit files respecitvely is enough. If this heuristic should
129 really fail for some file the code in `_dl_map_object_from_fd'
130 knows how to recover. */
131 struct filebuf
133 ssize_t len;
134 #if __WORDSIZE == 32
135 # define FILEBUF_SIZE 512
136 #else
137 # define FILEBUF_SIZE 640
138 #endif
139 char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
142 /* This is the decomposed LD_LIBRARY_PATH search path. */
143 static struct r_search_path_struct env_path_list attribute_relro;
145 /* List of the hardware capabilities we might end up using. */
146 static const struct r_strlenpair *capstr attribute_relro;
147 static size_t ncapstr attribute_relro;
148 static size_t max_capstrlen attribute_relro;
151 /* Get the generated information about the trusted directories. */
152 #include "trusted-dirs.h"
154 static const char system_dirs[] = SYSTEM_DIRS;
155 static const size_t system_dirs_len[] =
157 SYSTEM_DIRS_LEN
159 #define nsystem_dirs_len \
160 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
163 /* Local version of `strdup' function. */
164 static inline char *
165 local_strdup (const char *s)
167 size_t len = strlen (s) + 1;
168 void *new = malloc (len);
170 if (new == NULL)
171 return NULL;
173 return (char *) memcpy (new, s, len);
177 static size_t
178 is_dst (const char *start, const char *name, const char *str,
179 int is_path, int secure)
181 size_t len;
182 bool is_curly = false;
184 if (name[0] == '{')
186 is_curly = true;
187 ++name;
190 len = 0;
191 while (name[len] == str[len] && name[len] != '\0')
192 ++len;
194 if (is_curly)
196 if (name[len] != '}')
197 return 0;
199 /* Point again at the beginning of the name. */
200 --name;
201 /* Skip over closing curly brace and adjust for the --name. */
202 len += 2;
204 else if (name[len] != '\0' && name[len] != '/'
205 && (!is_path || name[len] != ':'))
206 return 0;
208 if (__builtin_expect (secure, 0)
209 && ((name[len] != '\0' && (!is_path || name[len] != ':'))
210 || (name != start + 1 && (!is_path || name[-2] != ':'))))
211 return 0;
213 return len;
217 size_t
218 _dl_dst_count (const char *name, int is_path)
220 const char *const start = name;
221 size_t cnt = 0;
225 size_t len;
227 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
228 is $ORIGIN alone) and it must always appear first in path. */
229 ++name;
230 if ((len = is_dst (start, name, "ORIGIN", is_path,
231 INTUSE(__libc_enable_secure))) != 0
232 || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0
233 || (len = is_dst (start, name, "LIB", is_path, 0)) != 0)
234 ++cnt;
236 name = strchr (name + len, '$');
238 while (name != NULL);
240 return cnt;
244 char *
245 _dl_dst_substitute (struct link_map *l, const char *name, char *result,
246 int is_path)
248 const char *const start = name;
249 char *last_elem, *wp;
251 /* Now fill the result path. While copying over the string we keep
252 track of the start of the last path element. When we come accross
253 a DST we copy over the value or (if the value is not available)
254 leave the entire path element out. */
255 last_elem = wp = result;
259 if (__builtin_expect (*name == '$', 0))
261 const char *repl = NULL;
262 size_t len;
264 ++name;
265 if ((len = is_dst (start, name, "ORIGIN", is_path,
266 INTUSE(__libc_enable_secure))) != 0)
267 repl = l->l_origin;
268 else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0)
269 repl = GLRO(dl_platform);
270 else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0)
271 repl = DL_DST_LIB;
273 if (repl != NULL && repl != (const char *) -1)
275 wp = __stpcpy (wp, repl);
276 name += len;
278 else if (len > 1)
280 /* We cannot use this path element, the value of the
281 replacement is unknown. */
282 wp = last_elem;
283 name += len;
284 while (*name != '\0' && (!is_path || *name != ':'))
285 ++name;
287 else
288 /* No DST we recognize. */
289 *wp++ = '$';
291 else
293 *wp++ = *name++;
294 if (is_path && *name == ':')
295 last_elem = wp;
298 while (*name != '\0');
300 *wp = '\0';
302 return result;
306 /* Return copy of argument with all recognized dynamic string tokens
307 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
308 might not be possible to determine the path from which the object
309 belonging to the map is loaded. In this case the path element
310 containing $ORIGIN is left out. */
311 static char *
312 expand_dynamic_string_token (struct link_map *l, const char *s)
314 /* We make two runs over the string. First we determine how large the
315 resulting string is and then we copy it over. Since this is now
316 frequently executed operation we are looking here not for performance
317 but rather for code size. */
318 size_t cnt;
319 size_t total;
320 char *result;
322 /* Determine the number of DST elements. */
323 cnt = DL_DST_COUNT (s, 1);
325 /* If we do not have to replace anything simply copy the string. */
326 if (__builtin_expect (cnt, 0) == 0)
327 return local_strdup (s);
329 /* Determine the length of the substituted string. */
330 total = DL_DST_REQUIRED (l, s, strlen (s), cnt);
332 /* Allocate the necessary memory. */
333 result = (char *) malloc (total + 1);
334 if (result == NULL)
335 return NULL;
337 return _dl_dst_substitute (l, s, result, 1);
341 /* Add `name' to the list of names for a particular shared object.
342 `name' is expected to have been allocated with malloc and will
343 be freed if the shared object already has this name.
344 Returns false if the object already had this name. */
345 static void
346 internal_function
347 add_name_to_object (struct link_map *l, const char *name)
349 struct libname_list *lnp, *lastp;
350 struct libname_list *newname;
351 size_t name_len;
353 lastp = NULL;
354 for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
355 if (strcmp (name, lnp->name) == 0)
356 return;
358 name_len = strlen (name) + 1;
359 newname = (struct libname_list *) malloc (sizeof *newname + name_len);
360 if (newname == NULL)
362 /* No more memory. */
363 _dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
364 return;
366 /* The object should have a libname set from _dl_new_object. */
367 assert (lastp != NULL);
369 newname->name = memcpy (newname + 1, name, name_len);
370 newname->next = NULL;
371 newname->dont_free = 0;
372 lastp->next = newname;
375 /* Standard search directories. */
376 static struct r_search_path_struct rtld_search_dirs attribute_relro;
378 static size_t max_dirnamelen;
380 static struct r_search_path_elem **
381 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
382 int check_trusted, const char *what, const char *where)
384 char *cp;
385 size_t nelems = 0;
387 while ((cp = __strsep (&rpath, sep)) != NULL)
389 struct r_search_path_elem *dirp;
390 size_t len = strlen (cp);
392 /* `strsep' can pass an empty string. This has to be
393 interpreted as `use the current directory'. */
394 if (len == 0)
396 static const char curwd[] = "./";
397 cp = (char *) curwd;
400 /* Remove trailing slashes (except for "/"). */
401 while (len > 1 && cp[len - 1] == '/')
402 --len;
404 /* Now add one if there is none so far. */
405 if (len > 0 && cp[len - 1] != '/')
406 cp[len++] = '/';
408 /* Make sure we don't use untrusted directories if we run SUID. */
409 if (__builtin_expect (check_trusted, 0))
411 const char *trun = system_dirs;
412 size_t idx;
413 int unsecure = 1;
415 /* All trusted directories must be complete names. */
416 if (cp[0] == '/')
418 for (idx = 0; idx < nsystem_dirs_len; ++idx)
420 if (len == system_dirs_len[idx]
421 && memcmp (trun, cp, len) == 0)
423 /* Found it. */
424 unsecure = 0;
425 break;
428 trun += system_dirs_len[idx] + 1;
432 if (unsecure)
433 /* Simply drop this directory. */
434 continue;
437 /* See if this directory is already known. */
438 for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
439 if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
440 break;
442 if (dirp != NULL)
444 /* It is available, see whether it's on our own list. */
445 size_t cnt;
446 for (cnt = 0; cnt < nelems; ++cnt)
447 if (result[cnt] == dirp)
448 break;
450 if (cnt == nelems)
451 result[nelems++] = dirp;
453 else
455 size_t cnt;
456 enum r_dir_status init_val;
457 size_t where_len = where ? strlen (where) + 1 : 0;
459 /* It's a new directory. Create an entry and add it. */
460 dirp = (struct r_search_path_elem *)
461 malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
462 + where_len + len + 1);
463 if (dirp == NULL)
464 _dl_signal_error (ENOMEM, NULL, NULL,
465 N_("cannot create cache for search path"));
467 dirp->dirname = ((char *) dirp + sizeof (*dirp)
468 + ncapstr * sizeof (enum r_dir_status));
469 *((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
470 dirp->dirnamelen = len;
472 if (len > max_dirnamelen)
473 max_dirnamelen = len;
475 /* We have to make sure all the relative directories are
476 never ignored. The current directory might change and
477 all our saved information would be void. */
478 init_val = cp[0] != '/' ? existing : unknown;
479 for (cnt = 0; cnt < ncapstr; ++cnt)
480 dirp->status[cnt] = init_val;
482 dirp->what = what;
483 if (__builtin_expect (where != NULL, 1))
484 dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
485 + (ncapstr * sizeof (enum r_dir_status)),
486 where, where_len);
487 else
488 dirp->where = NULL;
490 dirp->next = GL(dl_all_dirs);
491 GL(dl_all_dirs) = dirp;
493 /* Put it in the result array. */
494 result[nelems++] = dirp;
498 /* Terminate the array. */
499 result[nelems] = NULL;
501 return result;
505 static void
506 internal_function
507 decompose_rpath (struct r_search_path_struct *sps,
508 const char *rpath, struct link_map *l, const char *what)
510 /* Make a copy we can work with. */
511 const char *where = l->l_name;
512 char *copy;
513 char *cp;
514 struct r_search_path_elem **result;
515 size_t nelems;
516 /* Initialize to please the compiler. */
517 const char *errstring = NULL;
519 /* First see whether we must forget the RUNPATH and RPATH from this
520 object. */
521 if (__builtin_expect (GLRO(dl_inhibit_rpath) != NULL, 0)
522 && !INTUSE(__libc_enable_secure))
524 const char *inhp = GLRO(dl_inhibit_rpath);
528 const char *wp = where;
530 while (*inhp == *wp && *wp != '\0')
532 ++inhp;
533 ++wp;
536 if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
538 /* This object is on the list of objects for which the
539 RUNPATH and RPATH must not be used. */
540 result = calloc (1, sizeof *result);
541 if (result == NULL)
543 signal_error_cache:
544 errstring = N_("cannot create cache for search path");
545 signal_error:
546 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
549 sps->dirs = result;
550 sps->malloced = 1;
552 return;
555 while (*inhp != '\0')
556 if (*inhp++ == ':')
557 break;
559 while (*inhp != '\0');
562 /* Make a writable copy. At the same time expand possible dynamic
563 string tokens. */
564 copy = expand_dynamic_string_token (l, rpath);
565 if (copy == NULL)
567 errstring = N_("cannot create RUNPATH/RPATH copy");
568 goto signal_error;
571 /* Count the number of necessary elements in the result array. */
572 nelems = 0;
573 for (cp = copy; *cp != '\0'; ++cp)
574 if (*cp == ':')
575 ++nelems;
577 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
578 number of necessary entries. */
579 result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
580 * sizeof (*result));
581 if (result == NULL)
582 goto signal_error_cache;
584 fillin_rpath (copy, result, ":", 0, what, where);
586 /* Free the copied RPATH string. `fillin_rpath' make own copies if
587 necessary. */
588 free (copy);
590 sps->dirs = result;
591 /* The caller will change this value if we haven't used a real malloc. */
592 sps->malloced = 1;
595 /* Make sure cached path information is stored in *SP
596 and return true if there are any paths to search there. */
597 static bool
598 cache_rpath (struct link_map *l,
599 struct r_search_path_struct *sp,
600 int tag,
601 const char *what)
603 if (sp->dirs == (void *) -1)
604 return false;
606 if (sp->dirs != NULL)
607 return true;
609 if (l->l_info[tag] == NULL)
611 /* There is no path. */
612 sp->dirs = (void *) -1;
613 return false;
616 /* Make sure the cache information is available. */
617 decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
618 + l->l_info[tag]->d_un.d_val),
619 l, what);
620 return true;
624 void
625 internal_function
626 _dl_init_paths (const char *llp)
628 size_t idx;
629 const char *strp;
630 struct r_search_path_elem *pelem, **aelem;
631 size_t round_size;
632 #ifdef SHARED
633 struct link_map *l;
634 #endif
635 /* Initialize to please the compiler. */
636 const char *errstring = NULL;
638 /* Fill in the information about the application's RPATH and the
639 directories addressed by the LD_LIBRARY_PATH environment variable. */
641 /* Get the capabilities. */
642 capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
643 &ncapstr, &max_capstrlen);
645 /* First set up the rest of the default search directory entries. */
646 aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
647 malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
648 if (rtld_search_dirs.dirs == NULL)
650 errstring = N_("cannot create search path array");
651 signal_error:
652 _dl_signal_error (ENOMEM, NULL, NULL, errstring);
655 round_size = ((2 * sizeof (struct r_search_path_elem) - 1
656 + ncapstr * sizeof (enum r_dir_status))
657 / sizeof (struct r_search_path_elem));
659 rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
660 malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
661 * round_size * sizeof (struct r_search_path_elem));
662 if (rtld_search_dirs.dirs[0] == NULL)
664 errstring = N_("cannot create cache for search path");
665 goto signal_error;
668 rtld_search_dirs.malloced = 0;
669 pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
670 strp = system_dirs;
671 idx = 0;
675 size_t cnt;
677 *aelem++ = pelem;
679 pelem->what = "system search path";
680 pelem->where = NULL;
682 pelem->dirname = strp;
683 pelem->dirnamelen = system_dirs_len[idx];
684 strp += system_dirs_len[idx] + 1;
686 /* System paths must be absolute. */
687 assert (pelem->dirname[0] == '/');
688 for (cnt = 0; cnt < ncapstr; ++cnt)
689 pelem->status[cnt] = unknown;
691 pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
693 pelem += round_size;
695 while (idx < nsystem_dirs_len);
697 max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
698 *aelem = NULL;
700 #ifdef SHARED
701 /* This points to the map of the main object. */
702 l = GL(dl_loaded);
703 if (l != NULL)
705 assert (l->l_type != lt_loaded);
707 if (l->l_info[DT_RUNPATH])
709 /* Allocate room for the search path and fill in information
710 from RUNPATH. */
711 decompose_rpath (&l->l_runpath_dirs,
712 (const void *) (D_PTR (l, l_info[DT_STRTAB])
713 + l->l_info[DT_RUNPATH]->d_un.d_val),
714 l, "RUNPATH");
716 /* The RPATH is ignored. */
717 l->l_rpath_dirs.dirs = (void *) -1;
719 else
721 l->l_runpath_dirs.dirs = (void *) -1;
723 if (l->l_info[DT_RPATH])
725 /* Allocate room for the search path and fill in information
726 from RPATH. */
727 decompose_rpath (&l->l_rpath_dirs,
728 (const void *) (D_PTR (l, l_info[DT_STRTAB])
729 + l->l_info[DT_RPATH]->d_un.d_val),
730 l, "RPATH");
731 l->l_rpath_dirs.malloced = 0;
733 else
734 l->l_rpath_dirs.dirs = (void *) -1;
737 #endif /* SHARED */
739 if (llp != NULL && *llp != '\0')
741 size_t nllp;
742 const char *cp = llp;
743 char *llp_tmp = strdupa (llp);
745 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
746 elements it has. */
747 nllp = 1;
748 while (*cp)
750 if (*cp == ':' || *cp == ';')
751 ++nllp;
752 ++cp;
755 env_path_list.dirs = (struct r_search_path_elem **)
756 malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
757 if (env_path_list.dirs == NULL)
759 errstring = N_("cannot create cache for search path");
760 goto signal_error;
763 (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
764 INTUSE(__libc_enable_secure), "LD_LIBRARY_PATH",
765 NULL);
767 if (env_path_list.dirs[0] == NULL)
769 free (env_path_list.dirs);
770 env_path_list.dirs = (void *) -1;
773 env_path_list.malloced = 0;
775 else
776 env_path_list.dirs = (void *) -1;
778 /* Remember the last search directory added at startup. */
779 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
783 static void
784 __attribute__ ((noreturn, noinline))
785 lose (int code, int fd, const char *name, char *realname, struct link_map *l,
786 const char *msg)
788 /* The file might already be closed. */
789 if (fd != -1)
790 (void) __close (fd);
791 if (l != NULL)
793 /* Remove the stillborn object from the list and free it. */
794 assert (l->l_next == NULL);
795 if (l->l_prev == NULL)
796 /* No other module loaded. This happens only in the static library,
797 or in rtld under --verify. */
798 GL(dl_loaded) = NULL;
799 else
800 l->l_prev->l_next = NULL;
801 --GL(dl_nloaded);
802 free (l);
804 free (realname);
805 _dl_signal_error (code, name, NULL, msg);
809 /* Map in the shared object NAME, actually located in REALNAME, and already
810 opened on FD. */
812 #ifndef EXTERNAL_MAP_FROM_FD
813 static
814 #endif
815 struct link_map *
816 _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
817 char *realname, struct link_map *loader, int l_type,
818 int mode, void **stack_endp)
820 struct link_map *l = NULL;
821 const ElfW(Ehdr) *header;
822 const ElfW(Phdr) *phdr;
823 const ElfW(Phdr) *ph;
824 size_t maplength;
825 int type;
826 struct stat64 st;
827 /* Initialize to keep the compiler happy. */
828 const char *errstring = NULL;
829 int errval = 0;
831 /* Get file information. */
832 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0))
834 errstring = N_("cannot stat shared object");
835 call_lose_errno:
836 errval = errno;
837 call_lose:
838 lose (errval, fd, name, realname, l, errstring);
841 /* Look again to see if the real name matched another already loaded. */
842 for (l = GL(dl_loaded); l; l = l->l_next)
843 if (l->l_ino == st.st_ino && l->l_dev == st.st_dev)
845 /* The object is already loaded.
846 Just bump its reference count and return it. */
847 __close (fd);
849 /* If the name is not in the list of names for this object add
850 it. */
851 free (realname);
852 add_name_to_object (l, name);
854 return l;
857 if (mode & RTLD_NOLOAD)
858 /* We are not supposed to load the object unless it is already
859 loaded. So return now. */
860 return NULL;
862 /* Print debugging message. */
863 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
864 _dl_debug_printf ("file=%s; generating link map\n", name);
866 /* This is the ELF header. We read it in `open_verify'. */
867 header = (void *) fbp->buf;
869 #ifndef MAP_ANON
870 # define MAP_ANON 0
871 if (_dl_zerofd == -1)
873 _dl_zerofd = _dl_sysdep_open_zero_fill ();
874 if (_dl_zerofd == -1)
876 __close (fd);
877 _dl_signal_error (errno, NULL, NULL,
878 N_("cannot open zero fill device"));
881 #endif
883 /* Enter the new object in the list of loaded objects. */
884 l = _dl_new_object (realname, name, l_type, loader, mode);
885 if (__builtin_expect (! l, 0))
887 errstring = N_("cannot create shared object descriptor");
888 goto call_lose_errno;
891 /* Extract the remaining details we need from the ELF header
892 and then read in the program header table. */
893 l->l_entry = header->e_entry;
894 type = header->e_type;
895 l->l_phnum = header->e_phnum;
897 maplength = header->e_phnum * sizeof (ElfW(Phdr));
898 if (header->e_phoff + maplength <= (size_t) fbp->len)
899 phdr = (void *) (fbp->buf + header->e_phoff);
900 else
902 phdr = alloca (maplength);
903 __lseek (fd, header->e_phoff, SEEK_SET);
904 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
906 errstring = N_("cannot read file data");
907 goto call_lose_errno;
911 /* Presumed absent PT_GNU_STACK. */
912 uint_fast16_t stack_flags = PF_R|PF_W|PF_X;
915 /* Scan the program header table, collecting its load commands. */
916 struct loadcmd
918 ElfW(Addr) mapstart, mapend, dataend, allocend;
919 off_t mapoff;
920 int prot;
921 } loadcmds[l->l_phnum], *c;
922 size_t nloadcmds = 0;
923 bool has_holes = false;
925 /* The struct is initialized to zero so this is not necessary:
926 l->l_ld = 0;
927 l->l_phdr = 0;
928 l->l_addr = 0; */
929 for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
930 switch (ph->p_type)
932 /* These entries tell us where to find things once the file's
933 segments are mapped in. We record the addresses it says
934 verbatim, and later correct for the run-time load address. */
935 case PT_DYNAMIC:
936 l->l_ld = (void *) ph->p_vaddr;
937 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
938 break;
940 case PT_PHDR:
941 l->l_phdr = (void *) ph->p_vaddr;
942 break;
944 case PT_LOAD:
945 /* A load command tells us to map in part of the file.
946 We record the load commands and process them all later. */
947 if (__builtin_expect ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0,
950 errstring = N_("ELF load command alignment not page-aligned");
951 goto call_lose;
953 if (__builtin_expect (((ph->p_vaddr - ph->p_offset)
954 & (ph->p_align - 1)) != 0, 0))
956 errstring
957 = N_("ELF load command address/offset not properly aligned");
958 goto call_lose;
961 c = &loadcmds[nloadcmds++];
962 c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
963 c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
964 & ~(GLRO(dl_pagesize) - 1));
965 c->dataend = ph->p_vaddr + ph->p_filesz;
966 c->allocend = ph->p_vaddr + ph->p_memsz;
967 c->mapoff = ph->p_offset & ~(ph->p_align - 1);
969 /* Determine whether there is a gap between the last segment
970 and this one. */
971 if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
972 has_holes = true;
974 /* Optimize a common case. */
975 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
976 c->prot = (PF_TO_PROT
977 >> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
978 #else
979 c->prot = 0;
980 if (ph->p_flags & PF_R)
981 c->prot |= PROT_READ;
982 if (ph->p_flags & PF_W)
983 c->prot |= PROT_WRITE;
984 if (ph->p_flags & PF_X)
985 c->prot |= PROT_EXEC;
986 #endif
987 break;
989 case PT_TLS:
990 #ifdef USE_TLS
991 if (ph->p_memsz == 0)
992 /* Nothing to do for an empty segment. */
993 break;
995 l->l_tls_blocksize = ph->p_memsz;
996 l->l_tls_align = ph->p_align;
997 if (ph->p_align == 0)
998 l->l_tls_firstbyte_offset = 0;
999 else
1000 l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
1001 l->l_tls_initimage_size = ph->p_filesz;
1002 /* Since we don't know the load address yet only store the
1003 offset. We will adjust it later. */
1004 l->l_tls_initimage = (void *) ph->p_vaddr;
1006 /* If not loading the initial set of shared libraries,
1007 check whether we should permit loading a TLS segment. */
1008 if (__builtin_expect (l->l_type == lt_library, 1)
1009 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1010 not set up TLS data structures, so don't use them now. */
1011 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list) != NULL, 1))
1013 /* Assign the next available module ID. */
1014 l->l_tls_modid = _dl_next_tls_modid ();
1015 break;
1018 # ifdef SHARED
1019 if (l->l_prev == NULL)
1020 /* We are loading the executable itself when the dynamic linker
1021 was executed directly. The setup will happen later. */
1022 break;
1024 /* In a static binary there is no way to tell if we dynamically
1025 loaded libpthread. */
1026 if (GL(dl_error_catch_tsd) == &_dl_initial_error_catch_tsd)
1027 # endif
1029 /* We have not yet loaded libpthread.
1030 We can do the TLS setup right now! */
1032 void *tcb;
1034 /* The first call allocates TLS bookkeeping data structures.
1035 Then we allocate the TCB for the initial thread. */
1036 if (__builtin_expect (_dl_tls_setup (), 0)
1037 || __builtin_expect ((tcb = _dl_allocate_tls (NULL)) == NULL,
1040 errval = ENOMEM;
1041 errstring = N_("\
1042 cannot allocate TLS data structures for initial thread");
1043 goto call_lose;
1046 /* Now we install the TCB in the thread register. */
1047 errstring = TLS_INIT_TP (tcb, 0);
1048 if (__builtin_expect (errstring == NULL, 1))
1050 /* Now we are all good. */
1051 l->l_tls_modid = ++GL(dl_tls_max_dtv_idx);
1052 break;
1055 /* The kernel is too old or somesuch. */
1056 errval = 0;
1057 _dl_deallocate_tls (tcb, 1);
1058 goto call_lose;
1060 #endif
1062 /* Uh-oh, the binary expects TLS support but we cannot
1063 provide it. */
1064 errval = 0;
1065 errstring = N_("cannot handle TLS data");
1066 goto call_lose;
1067 break;
1069 case PT_GNU_STACK:
1070 stack_flags = ph->p_flags;
1071 break;
1073 case PT_GNU_RELRO:
1074 l->l_relro_addr = ph->p_vaddr;
1075 l->l_relro_size = ph->p_memsz;
1076 break;
1079 if (__builtin_expect (nloadcmds == 0, 0))
1081 /* This only happens for a bogus object that will be caught with
1082 another error below. But we don't want to go through the
1083 calculations below using NLOADCMDS - 1. */
1084 errstring = N_("object file has no loadable segments");
1085 goto call_lose;
1088 /* Now process the load commands and map segments into memory. */
1089 c = loadcmds;
1091 /* Length of the sections to be loaded. */
1092 maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;
1094 if (__builtin_expect (type, ET_DYN) == ET_DYN)
1096 /* This is a position-independent shared object. We can let the
1097 kernel map it anywhere it likes, but we must have space for all
1098 the segments in their specified positions relative to the first.
1099 So we map the first segment without MAP_FIXED, but with its
1100 extent increased to cover all the segments. Then we remove
1101 access from excess portion, and there is known sufficient space
1102 there to remap from the later segments.
1104 As a refinement, sometimes we have an address that we would
1105 prefer to map such objects at; but this is only a preference,
1106 the OS can do whatever it likes. */
1107 ElfW(Addr) mappref;
1108 mappref = (ELF_PREFERRED_ADDRESS (loader, maplength,
1109 c->mapstart & GLRO(dl_use_load_bias))
1110 - MAP_BASE_ADDR (l));
1112 /* Remember which part of the address space this object uses. */
1113 l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength,
1114 c->prot,
1115 MAP_COPY|MAP_FILE|MAP_DENYWRITE,
1116 fd, c->mapoff);
1117 if (__builtin_expect ((void *) l->l_map_start == MAP_FAILED, 0))
1119 map_error:
1120 errstring = N_("failed to map segment from shared object");
1121 goto call_lose_errno;
1124 l->l_map_end = l->l_map_start + maplength;
1125 l->l_addr = l->l_map_start - c->mapstart;
1127 if (has_holes)
1128 /* Change protection on the excess portion to disallow all access;
1129 the portions we do not remap later will be inaccessible as if
1130 unallocated. Then jump into the normal segment-mapping loop to
1131 handle the portion of the segment past the end of the file
1132 mapping. */
1133 __mprotect ((caddr_t) (l->l_addr + c->mapend),
1134 loadcmds[nloadcmds - 1].allocend - c->mapend,
1135 PROT_NONE);
1137 goto postmap;
1140 /* This object is loaded at a fixed address. This must never
1141 happen for objects loaded with dlopen(). */
1142 if (__builtin_expect ((mode & __RTLD_OPENEXEC) == 0, 0))
1144 errstring = N_("cannot dynamically load executable");
1145 goto call_lose;
1148 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1149 fixed. */
1150 ELF_FIXED_ADDRESS (loader, c->mapstart);
1153 /* Remember which part of the address space this object uses. */
1154 l->l_map_start = c->mapstart + l->l_addr;
1155 l->l_map_end = l->l_map_start + maplength;
1157 while (c < &loadcmds[nloadcmds])
1159 if (c->mapend > c->mapstart
1160 /* Map the segment contents from the file. */
1161 && (__mmap ((void *) (l->l_addr + c->mapstart),
1162 c->mapend - c->mapstart, c->prot,
1163 MAP_FIXED|MAP_COPY|MAP_FILE|MAP_DENYWRITE,
1164 fd, c->mapoff)
1165 == MAP_FAILED))
1166 goto map_error;
1168 postmap:
1169 if (c->prot & PROT_EXEC)
1170 l->l_text_end = l->l_addr + c->mapend;
1172 if (l->l_phdr == 0
1173 && (ElfW(Off)) c->mapoff <= header->e_phoff
1174 && ((size_t) (c->mapend - c->mapstart + c->mapoff)
1175 >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
1176 /* Found the program header in this segment. */
1177 l->l_phdr = (void *) (c->mapstart + header->e_phoff - c->mapoff);
1179 if (c->allocend > c->dataend)
1181 /* Extra zero pages should appear at the end of this segment,
1182 after the data mapped from the file. */
1183 ElfW(Addr) zero, zeroend, zeropage;
1185 zero = l->l_addr + c->dataend;
1186 zeroend = l->l_addr + c->allocend;
1187 zeropage = ((zero + GLRO(dl_pagesize) - 1)
1188 & ~(GLRO(dl_pagesize) - 1));
1190 if (zeroend < zeropage)
1191 /* All the extra data is in the last page of the segment.
1192 We can just zero it. */
1193 zeropage = zeroend;
1195 if (zeropage > zero)
1197 /* Zero the final part of the last page of the segment. */
1198 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1200 /* Dag nab it. */
1201 if (__mprotect ((caddr_t) (zero
1202 & ~(GLRO(dl_pagesize) - 1)),
1203 GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0)
1205 errstring = N_("cannot change memory protections");
1206 goto call_lose_errno;
1209 memset ((void *) zero, '\0', zeropage - zero);
1210 if (__builtin_expect ((c->prot & PROT_WRITE) == 0, 0))
1211 __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)),
1212 GLRO(dl_pagesize), c->prot);
1215 if (zeroend > zeropage)
1217 /* Map the remaining zero pages in from the zero fill FD. */
1218 caddr_t mapat;
1219 mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,
1220 c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
1221 ANONFD, 0);
1222 if (__builtin_expect (mapat == MAP_FAILED, 0))
1224 errstring = N_("cannot map zero-fill pages");
1225 goto call_lose_errno;
1230 ++c;
1234 if (l->l_ld == 0)
1236 if (__builtin_expect (type == ET_DYN, 0))
1238 errstring = N_("object file has no dynamic section");
1239 goto call_lose;
1242 else
1243 l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1245 elf_get_dynamic_info (l, NULL);
1247 /* Make sure we are not dlopen'ing an object that has the
1248 DF_1_NOOPEN flag set. */
1249 if (__builtin_expect (l->l_flags_1 & DF_1_NOOPEN, 0)
1250 && (mode & __RTLD_DLOPEN))
1252 /* We are not supposed to load this object. Free all resources. */
1253 __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
1255 if (!l->l_libname->dont_free)
1256 free (l->l_libname);
1258 if (l->l_phdr_allocated)
1259 free ((void *) l->l_phdr);
1261 errstring = N_("shared object cannot be dlopen()ed");
1262 goto call_lose;
1265 if (l->l_phdr == NULL)
1267 /* The program header is not contained in any of the segments.
1268 We have to allocate memory ourself and copy it over from out
1269 temporary place. */
1270 ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
1271 * sizeof (ElfW(Phdr)));
1272 if (newp == NULL)
1274 errstring = N_("cannot allocate memory for program header");
1275 goto call_lose_errno;
1278 l->l_phdr = memcpy (newp, phdr,
1279 (header->e_phnum * sizeof (ElfW(Phdr))));
1280 l->l_phdr_allocated = 1;
1282 else
1283 /* Adjust the PT_PHDR value by the runtime load address. */
1284 l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
1286 if (__builtin_expect ((stack_flags &~ GL(dl_stack_flags)) & PF_X, 0))
1288 /* The stack is presently not executable, but this module
1289 requires that it be executable. We must change the
1290 protection of the variable which contains the flags used in
1291 the mprotect calls. */
1292 #ifdef HAVE_Z_RELRO
1293 if (mode & __RTLD_DLOPEN)
1295 uintptr_t p = ((uintptr_t) &__stack_prot) & ~(GLRO(dl_pagesize) - 1);
1296 size_t s = (uintptr_t) &__stack_prot - p + sizeof (int);
1298 __mprotect ((void *) p, s, PROT_READ|PROT_WRITE);
1299 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0),
1300 allow_ldso|allow_libc) == 0,
1302 __stack_prot |= PROT_EXEC;
1303 __mprotect ((void *) p, s, PROT_READ);
1305 else
1306 #endif
1307 __stack_prot |= PROT_EXEC;
1309 errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
1310 if (errval)
1312 errstring = N_("\
1313 cannot enable executable stack as shared object requires");
1314 goto call_lose;
1318 #ifdef USE_TLS
1319 /* Adjust the address of the TLS initialization image. */
1320 if (l->l_tls_initimage != NULL)
1321 l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
1322 #endif
1324 /* We are done mapping in the file. We no longer need the descriptor. */
1325 if (__builtin_expect (__close (fd) != 0, 0))
1327 errstring = N_("cannot close file descriptor");
1328 goto call_lose_errno;
1330 /* Signal that we closed the file. */
1331 fd = -1;
1333 if (l->l_type == lt_library && type == ET_EXEC)
1334 l->l_type = lt_executable;
1336 l->l_entry += l->l_addr;
1338 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
1339 _dl_debug_printf ("\
1340 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1341 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1342 (int) sizeof (void *) * 2,
1343 (unsigned long int) l->l_ld,
1344 (int) sizeof (void *) * 2,
1345 (unsigned long int) l->l_addr,
1346 (int) sizeof (void *) * 2, maplength,
1347 (int) sizeof (void *) * 2,
1348 (unsigned long int) l->l_entry,
1349 (int) sizeof (void *) * 2,
1350 (unsigned long int) l->l_phdr,
1351 (int) sizeof (void *) * 2, l->l_phnum);
1353 /* Set up the symbol hash table. */
1354 _dl_setup_hash (l);
1356 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1357 have to do this for the main map. */
1358 if ((mode & RTLD_DEEPBIND) == 0
1359 && __builtin_expect (l->l_info[DT_SYMBOLIC] != NULL, 0)
1360 && &l->l_searchlist != l->l_scope[0])
1362 /* Create an appropriate searchlist. It contains only this map.
1363 This is the definition of DT_SYMBOLIC in SysVr4. */
1364 l->l_symbolic_searchlist.r_list =
1365 (struct link_map **) malloc (sizeof (struct link_map *));
1367 if (l->l_symbolic_searchlist.r_list == NULL)
1369 errstring = N_("cannot create searchlist");
1370 goto call_lose_errno;
1373 l->l_symbolic_searchlist.r_list[0] = l;
1374 l->l_symbolic_searchlist.r_nlist = 1;
1376 /* Now move the existing entries one back. */
1377 memmove (&l->l_scope[1], &l->l_scope[0],
1378 (l->l_scope_max - 1) * sizeof (l->l_scope[0]));
1380 /* Now add the new entry. */
1381 l->l_scope[0] = &l->l_symbolic_searchlist;
1384 /* Remember whether this object must be initialized first. */
1385 if (l->l_flags_1 & DF_1_INITFIRST)
1386 GL(dl_initfirst) = l;
1388 /* Finally the file information. */
1389 l->l_dev = st.st_dev;
1390 l->l_ino = st.st_ino;
1392 /* When we profile the SONAME might be needed for something else but
1393 loading. Add it right away. */
1394 if (__builtin_expect (GLRO(dl_profile) != NULL, 0)
1395 && l->l_info[DT_SONAME] != NULL)
1396 add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
1397 + l->l_info[DT_SONAME]->d_un.d_val));
1399 return l;
1402 /* Print search path. */
1403 static void
1404 print_search_path (struct r_search_path_elem **list,
1405 const char *what, const char *name)
1407 char buf[max_dirnamelen + max_capstrlen];
1408 int first = 1;
1410 _dl_debug_printf (" search path=");
1412 while (*list != NULL && (*list)->what == what) /* Yes, ==. */
1414 char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
1415 size_t cnt;
1417 for (cnt = 0; cnt < ncapstr; ++cnt)
1418 if ((*list)->status[cnt] != nonexisting)
1420 char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
1421 if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
1422 cp[0] = '\0';
1423 else
1424 cp[-1] = '\0';
1426 _dl_debug_printf_c (first ? "%s" : ":%s", buf);
1427 first = 0;
1430 ++list;
1433 if (name != NULL)
1434 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
1435 name[0] ? name : rtld_progname);
1436 else
1437 _dl_debug_printf_c ("\t\t(%s)\n", what);
1440 /* Open a file and verify it is an ELF file for this architecture. We
1441 ignore only ELF files for other architectures. Non-ELF files and
1442 ELF files with different header information cause fatal errors since
1443 this could mean there is something wrong in the installation and the
1444 user might want to know about this. */
1445 static int
1446 open_verify (const char *name, struct filebuf *fbp)
1448 /* This is the expected ELF header. */
1449 #define ELF32_CLASS ELFCLASS32
1450 #define ELF64_CLASS ELFCLASS64
1451 #ifndef VALID_ELF_HEADER
1452 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1453 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1454 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1455 #endif
1456 static const unsigned char expected[EI_PAD] =
1458 [EI_MAG0] = ELFMAG0,
1459 [EI_MAG1] = ELFMAG1,
1460 [EI_MAG2] = ELFMAG2,
1461 [EI_MAG3] = ELFMAG3,
1462 [EI_CLASS] = ELFW(CLASS),
1463 [EI_DATA] = byteorder,
1464 [EI_VERSION] = EV_CURRENT,
1465 [EI_OSABI] = ELFOSABI_SYSV,
1466 [EI_ABIVERSION] = 0
1468 static const struct
1470 ElfW(Word) vendorlen;
1471 ElfW(Word) datalen;
1472 ElfW(Word) type;
1473 char vendor[4];
1474 } expected_note = { 4, 16, 1, "GNU" };
1475 int fd;
1476 /* Initialize it to make the compiler happy. */
1477 const char *errstring = NULL;
1478 int errval = 0;
1480 /* Open the file. We always open files read-only. */
1481 fd = __open (name, O_RDONLY);
1482 if (fd != -1)
1484 ElfW(Ehdr) *ehdr;
1485 ElfW(Phdr) *phdr, *ph;
1486 ElfW(Word) *abi_note, abi_note_buf[8];
1487 unsigned int osversion;
1488 size_t maplength;
1490 /* We successfully openened the file. Now verify it is a file
1491 we can use. */
1492 __set_errno (0);
1493 fbp->len = __libc_read (fd, fbp->buf, sizeof (fbp->buf));
1495 /* This is where the ELF header is loaded. */
1496 assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
1497 ehdr = (ElfW(Ehdr) *) fbp->buf;
1499 /* Now run the tests. */
1500 if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0))
1502 errval = errno;
1503 errstring = (errval == 0
1504 ? N_("file too short") : N_("cannot read file data"));
1505 call_lose:
1506 lose (errval, fd, name, NULL, NULL, errstring);
1509 /* See whether the ELF header is what we expect. */
1510 if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
1511 EI_PAD), 0))
1513 /* Something is wrong. */
1514 if (*(Elf32_Word *) &ehdr->e_ident !=
1515 #if BYTE_ORDER == LITTLE_ENDIAN
1516 ((ELFMAG0 << (EI_MAG0 * 8)) |
1517 (ELFMAG1 << (EI_MAG1 * 8)) |
1518 (ELFMAG2 << (EI_MAG2 * 8)) |
1519 (ELFMAG3 << (EI_MAG3 * 8)))
1520 #else
1521 ((ELFMAG0 << (EI_MAG3 * 8)) |
1522 (ELFMAG1 << (EI_MAG2 * 8)) |
1523 (ELFMAG2 << (EI_MAG1 * 8)) |
1524 (ELFMAG3 << (EI_MAG0 * 8)))
1525 #endif
1527 errstring = N_("invalid ELF header");
1528 else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
1529 /* This is not a fatal error. On architectures where
1530 32-bit and 64-bit binaries can be run this might
1531 happen. */
1532 goto close_and_out;
1533 else if (ehdr->e_ident[EI_DATA] != byteorder)
1535 if (BYTE_ORDER == BIG_ENDIAN)
1536 errstring = N_("ELF file data encoding not big-endian");
1537 else
1538 errstring = N_("ELF file data encoding not little-endian");
1540 else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
1541 errstring
1542 = N_("ELF file version ident does not match current one");
1543 /* XXX We should be able so set system specific versions which are
1544 allowed here. */
1545 else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
1546 errstring = N_("ELF file OS ABI invalid");
1547 else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION]))
1548 errstring = N_("ELF file ABI version invalid");
1549 else
1550 /* Otherwise we don't know what went wrong. */
1551 errstring = N_("internal error");
1553 goto call_lose;
1556 if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT)
1558 errstring = N_("ELF file version does not match current one");
1559 goto call_lose;
1561 if (! __builtin_expect (elf_machine_matches_host (ehdr), 1))
1562 goto close_and_out;
1563 else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN
1564 && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC)
1566 errstring = N_("only ET_DYN and ET_EXEC can be loaded");
1567 goto call_lose;
1569 else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
1570 != sizeof (ElfW(Phdr)))
1572 errstring = N_("ELF file's phentsize not the expected size");
1573 goto call_lose;
1576 maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
1577 if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
1578 phdr = (void *) (fbp->buf + ehdr->e_phoff);
1579 else
1581 phdr = alloca (maplength);
1582 __lseek (fd, ehdr->e_phoff, SEEK_SET);
1583 if ((size_t) __libc_read (fd, (void *) phdr, maplength) != maplength)
1585 read_error:
1586 errval = errno;
1587 errstring = N_("cannot read file data");
1588 goto call_lose;
1592 /* Check .note.ABI-tag if present. */
1593 for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
1594 if (ph->p_type == PT_NOTE && ph->p_filesz == 32 && ph->p_align >= 4)
1596 if (ph->p_offset + 32 <= (size_t) fbp->len)
1597 abi_note = (void *) (fbp->buf + ph->p_offset);
1598 else
1600 __lseek (fd, ph->p_offset, SEEK_SET);
1601 if (__libc_read (fd, (void *) abi_note_buf, 32) != 32)
1602 goto read_error;
1604 abi_note = abi_note_buf;
1607 if (memcmp (abi_note, &expected_note, sizeof (expected_note)))
1608 continue;
1610 osversion = (abi_note[5] & 0xff) * 65536
1611 + (abi_note[6] & 0xff) * 256
1612 + (abi_note[7] & 0xff);
1613 if (abi_note[4] != __ABI_TAG_OS
1614 || (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
1616 close_and_out:
1617 __close (fd);
1618 __set_errno (ENOENT);
1619 fd = -1;
1622 break;
1626 return fd;
1629 /* Try to open NAME in one of the directories in *DIRSP.
1630 Return the fd, or -1. If successful, fill in *REALNAME
1631 with the malloc'd full directory name. If it turns out
1632 that none of the directories in *DIRSP exists, *DIRSP is
1633 replaced with (void *) -1, and the old value is free()d
1634 if MAY_FREE_DIRS is true. */
1636 static int
1637 open_path (const char *name, size_t namelen, int preloaded,
1638 struct r_search_path_struct *sps, char **realname,
1639 struct filebuf *fbp)
1641 struct r_search_path_elem **dirs = sps->dirs;
1642 char *buf;
1643 int fd = -1;
1644 const char *current_what = NULL;
1645 int any = 0;
1647 buf = alloca (max_dirnamelen + max_capstrlen + namelen);
1650 struct r_search_path_elem *this_dir = *dirs;
1651 size_t buflen = 0;
1652 size_t cnt;
1653 char *edp;
1654 int here_any = 0;
1655 int err;
1657 /* If we are debugging the search for libraries print the path
1658 now if it hasn't happened now. */
1659 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)
1660 && current_what != this_dir->what)
1662 current_what = this_dir->what;
1663 print_search_path (dirs, current_what, this_dir->where);
1666 edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
1667 for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
1669 /* Skip this directory if we know it does not exist. */
1670 if (this_dir->status[cnt] == nonexisting)
1671 continue;
1673 buflen =
1674 ((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
1675 capstr[cnt].len),
1676 name, namelen)
1677 - buf);
1679 /* Print name we try if this is wanted. */
1680 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1681 _dl_debug_printf (" trying file=%s\n", buf);
1683 fd = open_verify (buf, fbp);
1684 if (this_dir->status[cnt] == unknown)
1686 if (fd != -1)
1687 this_dir->status[cnt] = existing;
1688 else
1690 /* We failed to open machine dependent library. Let's
1691 test whether there is any directory at all. */
1692 struct stat64 st;
1694 buf[buflen - namelen - 1] = '\0';
1696 if (__xstat64 (_STAT_VER, buf, &st) != 0
1697 || ! S_ISDIR (st.st_mode))
1698 /* The directory does not exist or it is no directory. */
1699 this_dir->status[cnt] = nonexisting;
1700 else
1701 this_dir->status[cnt] = existing;
1705 /* Remember whether we found any existing directory. */
1706 here_any |= this_dir->status[cnt] == existing;
1708 if (fd != -1 && __builtin_expect (preloaded, 0)
1709 && INTUSE(__libc_enable_secure))
1711 /* This is an extra security effort to make sure nobody can
1712 preload broken shared objects which are in the trusted
1713 directories and so exploit the bugs. */
1714 struct stat64 st;
1716 if (__fxstat64 (_STAT_VER, fd, &st) != 0
1717 || (st.st_mode & S_ISUID) == 0)
1719 /* The shared object cannot be tested for being SUID
1720 or this bit is not set. In this case we must not
1721 use this object. */
1722 __close (fd);
1723 fd = -1;
1724 /* We simply ignore the file, signal this by setting
1725 the error value which would have been set by `open'. */
1726 errno = ENOENT;
1731 if (fd != -1)
1733 *realname = (char *) malloc (buflen);
1734 if (*realname != NULL)
1736 memcpy (*realname, buf, buflen);
1737 return fd;
1739 else
1741 /* No memory for the name, we certainly won't be able
1742 to load and link it. */
1743 __close (fd);
1744 return -1;
1747 if (here_any && (err = errno) != ENOENT && err != EACCES)
1748 /* The file exists and is readable, but something went wrong. */
1749 return -1;
1751 /* Remember whether we found anything. */
1752 any |= here_any;
1754 while (*++dirs != NULL);
1756 /* Remove the whole path if none of the directories exists. */
1757 if (__builtin_expect (! any, 0))
1759 /* Paths which were allocated using the minimal malloc() in ld.so
1760 must not be freed using the general free() in libc. */
1761 if (sps->malloced)
1762 free (sps->dirs);
1763 sps->dirs = (void *) -1;
1766 return -1;
1769 /* Map in the shared object file NAME. */
1771 struct link_map *
1772 internal_function
1773 _dl_map_object (struct link_map *loader, const char *name, int preloaded,
1774 int type, int trace_mode, int mode)
1776 int fd;
1777 char *realname;
1778 char *name_copy;
1779 struct link_map *l;
1780 struct filebuf fb;
1782 /* Look for this name among those already loaded. */
1783 for (l = GL(dl_loaded); l; l = l->l_next)
1785 /* If the requested name matches the soname of a loaded object,
1786 use that object. Elide this check for names that have not
1787 yet been opened. */
1788 if (__builtin_expect (l->l_faked, 0) != 0)
1789 continue;
1790 if (!_dl_name_match_p (name, l))
1792 const char *soname;
1794 if (__builtin_expect (l->l_soname_added, 1)
1795 || l->l_info[DT_SONAME] == NULL)
1796 continue;
1798 soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
1799 + l->l_info[DT_SONAME]->d_un.d_val);
1800 if (strcmp (name, soname) != 0)
1801 continue;
1803 /* We have a match on a new name -- cache it. */
1804 add_name_to_object (l, soname);
1805 l->l_soname_added = 1;
1808 /* We have a match. */
1809 return l;
1812 /* Display information if we are debugging. */
1813 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
1814 && loader != NULL)
1815 _dl_debug_printf ("\nfile=%s; needed by %s\n", name,
1816 loader->l_name[0]
1817 ? loader->l_name : rtld_progname);
1819 if (strchr (name, '/') == NULL)
1821 /* Search for NAME in several places. */
1823 size_t namelen = strlen (name) + 1;
1825 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1826 _dl_debug_printf ("find library=%s; searching\n", name);
1828 fd = -1;
1830 /* When the object has the RUNPATH information we don't use any
1831 RPATHs. */
1832 if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
1834 /* First try the DT_RPATH of the dependent object that caused NAME
1835 to be loaded. Then that object's dependent, and on up. */
1836 for (l = loader; fd == -1 && l; l = l->l_loader)
1837 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
1838 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1839 &realname, &fb);
1841 /* If dynamically linked, try the DT_RPATH of the executable
1842 itself. */
1843 l = GL(dl_loaded);
1844 if (fd == -1 && l && l->l_type != lt_loaded && l != loader
1845 && l->l_rpath_dirs.dirs != (void *) -1)
1846 fd = open_path (name, namelen, preloaded, &l->l_rpath_dirs,
1847 &realname, &fb);
1850 /* Try the LD_LIBRARY_PATH environment variable. */
1851 if (fd == -1 && env_path_list.dirs != (void *) -1)
1852 fd = open_path (name, namelen, preloaded, &env_path_list,
1853 &realname, &fb);
1855 /* Look at the RUNPATH information for this binary. */
1856 if (fd == -1 && loader != NULL
1857 && cache_rpath (loader, &loader->l_runpath_dirs,
1858 DT_RUNPATH, "RUNPATH"))
1859 fd = open_path (name, namelen, preloaded,
1860 &loader->l_runpath_dirs, &realname, &fb);
1862 if (fd == -1
1863 && (__builtin_expect (! preloaded, 1)
1864 || ! INTUSE(__libc_enable_secure)))
1866 /* Check the list of libraries in the file /etc/ld.so.cache,
1867 for compatibility with Linux's ldconfig program. */
1868 const char *cached = _dl_load_cache_lookup (name);
1870 if (cached != NULL)
1872 #ifdef SHARED
1873 l = loader ?: GL(dl_loaded);
1874 #else
1875 l = loader;
1876 #endif
1878 /* If the loader has the DF_1_NODEFLIB flag set we must not
1879 use a cache entry from any of these directories. */
1880 if (
1881 #ifndef SHARED
1882 /* 'l' is always != NULL for dynamically linked objects. */
1883 l != NULL &&
1884 #endif
1885 __builtin_expect (l->l_flags_1 & DF_1_NODEFLIB, 0))
1887 const char *dirp = system_dirs;
1888 unsigned int cnt = 0;
1892 if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
1894 /* The prefix matches. Don't use the entry. */
1895 cached = NULL;
1896 break;
1899 dirp += system_dirs_len[cnt] + 1;
1900 ++cnt;
1902 while (cnt < nsystem_dirs_len);
1905 if (cached != NULL)
1907 fd = open_verify (cached, &fb);
1908 if (__builtin_expect (fd != -1, 1))
1910 realname = local_strdup (cached);
1911 if (realname == NULL)
1913 __close (fd);
1914 fd = -1;
1921 /* Finally, try the default path. */
1922 if (fd == -1
1923 && ((l = loader ?: GL(dl_loaded)) == NULL
1924 || __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
1925 && rtld_search_dirs.dirs != (void *) -1)
1926 fd = open_path (name, namelen, preloaded, &rtld_search_dirs,
1927 &realname, &fb);
1929 /* Add another newline when we are tracing the library loading. */
1930 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
1931 _dl_debug_printf ("\n");
1933 else
1935 /* The path may contain dynamic string tokens. */
1936 realname = (loader
1937 ? expand_dynamic_string_token (loader, name)
1938 : local_strdup (name));
1939 if (realname == NULL)
1940 fd = -1;
1941 else
1943 fd = open_verify (realname, &fb);
1944 if (__builtin_expect (fd, 0) == -1)
1945 free (realname);
1949 /* In case the LOADER information has only been provided to get to
1950 the appropriate RUNPATH/RPATH information we do not need it
1951 anymore. */
1952 if (mode & __RTLD_CALLMAP)
1953 loader = NULL;
1955 if (__builtin_expect (fd, 0) == -1)
1957 if (trace_mode
1958 && __builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) == 0)
1960 /* We haven't found an appropriate library. But since we
1961 are only interested in the list of libraries this isn't
1962 so severe. Fake an entry with all the information we
1963 have. */
1964 static const Elf_Symndx dummy_bucket = STN_UNDEF;
1966 /* Enter the new object in the list of loaded objects. */
1967 if ((name_copy = local_strdup (name)) == NULL
1968 || (l = _dl_new_object (name_copy, name, type, loader,
1969 mode)) == NULL)
1970 _dl_signal_error (ENOMEM, name, NULL,
1971 N_("cannot create shared object descriptor"));
1972 /* Signal that this is a faked entry. */
1973 l->l_faked = 1;
1974 /* Since the descriptor is initialized with zero we do not
1975 have do this here.
1976 l->l_reserved = 0; */
1977 l->l_buckets = &dummy_bucket;
1978 l->l_nbuckets = 1;
1979 l->l_relocated = 1;
1981 return l;
1983 else
1984 _dl_signal_error (errno, name, NULL,
1985 N_("cannot open shared object file"));
1988 void *stack_end = __libc_stack_end;
1989 return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
1990 &stack_end);
1994 void
1995 internal_function
1996 _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
1998 if (counting)
2000 si->dls_cnt = 0;
2001 si->dls_size = 0;
2004 unsigned int idx = 0;
2005 char *allocptr = (char *) &si->dls_serpath[si->dls_cnt];
2006 void add_path (const struct r_search_path_struct *sps, unsigned int flags)
2007 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2009 if (sps->dirs != (void *) -1)
2011 struct r_search_path_elem **dirs = sps->dirs;
2014 const struct r_search_path_elem *const r = *dirs++;
2015 if (counting)
2017 si->dls_cnt++;
2018 si->dls_size += r->dirnamelen;
2020 else
2022 Dl_serpath *const sp = &si->dls_serpath[idx++];
2023 sp->dls_name = allocptr;
2024 allocptr = __mempcpy (allocptr,
2025 r->dirname, r->dirnamelen - 1);
2026 *allocptr++ = '\0';
2027 sp->dls_flags = flags;
2030 while (*dirs != NULL);
2034 /* When the object has the RUNPATH information we don't use any RPATHs. */
2035 if (loader->l_info[DT_RUNPATH] == NULL)
2037 /* First try the DT_RPATH of the dependent object that caused NAME
2038 to be loaded. Then that object's dependent, and on up. */
2040 struct link_map *l = loader;
2043 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2044 add_path (&l->l_rpath_dirs, XXX_RPATH);
2045 l = l->l_loader;
2047 while (l != NULL);
2049 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2050 l = GL(dl_loaded);
2051 if (l != NULL && l->l_type != lt_loaded && l != loader)
2052 if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
2053 add_path (&l->l_rpath_dirs, XXX_RPATH);
2056 /* Try the LD_LIBRARY_PATH environment variable. */
2057 add_path (&env_path_list, XXX_ENV);
2059 /* Look at the RUNPATH information for this binary. */
2060 if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
2061 add_path (&loader->l_runpath_dirs, XXX_RUNPATH);
2063 /* XXX
2064 Here is where ld.so.cache gets checked, but we don't have
2065 a way to indicate that in the results for Dl_serinfo. */
2067 /* Finally, try the default path. */
2068 if (!(loader->l_flags_1 & DF_1_NODEFLIB))
2069 add_path (&rtld_search_dirs, XXX_default);
2071 if (counting)
2072 /* Count the struct size before the string area, which we didn't
2073 know before we completed dls_cnt. */
2074 si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;