1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2017 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
28 #include <bits/wordsize.h>
30 #include <sys/param.h>
32 #include <sys/types.h>
33 #include "dynamic-link.h"
35 #include <stackinfo.h>
38 #include <stap-probe.h>
39 #include <libc-pointer-arith.h>
43 #include <dl-map-segments.h>
44 #include <dl-unmap-segments.h>
45 #include <dl-machine-reject-phdr.h>
46 #include <dl-sysdep-open.h>
50 #if BYTE_ORDER == BIG_ENDIAN
51 # define byteorder ELFDATA2MSB
52 #elif BYTE_ORDER == LITTLE_ENDIAN
53 # define byteorder ELFDATA2LSB
55 # error "Unknown BYTE_ORDER " BYTE_ORDER
56 # define byteorder ELFDATANONE
59 #define STRING(x) __STRING (x)
62 int __stack_prot attribute_hidden attribute_relro
63 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
65 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
72 /* Type for the buffer we put the ELF header and hopefully the program
73 header. This buffer does not really have to be too large. In most
74 cases the program header follows the ELF header directly. If this
75 is not the case all bets are off and we can make the header
76 arbitrarily large and still won't get it read. This means the only
77 question is how large are the ELF and program header combined. The
78 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
79 bytes long. Each program header entry is again 32 and 56 bytes
80 long respectively. I.e., even with a file which has 10 program
81 header entries we only have to read 372B/624B respectively. Add to
82 this a bit of margin for program notes and reading 512B and 832B
83 for 32-bit and 64-bit files respecitvely is enough. If this
84 heuristic should really fail for some file the code in
85 `_dl_map_object_from_fd' knows how to recover. */
90 # define FILEBUF_SIZE 512
92 # define FILEBUF_SIZE 832
94 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
97 /* This is the decomposed LD_LIBRARY_PATH search path. */
98 static struct r_search_path_struct env_path_list attribute_relro
;
100 /* List of the hardware capabilities we might end up using. */
101 static const struct r_strlenpair
*capstr attribute_relro
;
102 static size_t ncapstr attribute_relro
;
103 static size_t max_capstrlen attribute_relro
;
106 /* Get the generated information about the trusted directories. */
107 #include "trusted-dirs.h"
109 static const char system_dirs
[] = SYSTEM_DIRS
;
110 static const size_t system_dirs_len
[] =
114 #define nsystem_dirs_len \
115 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
119 is_trusted_path (const char *path
, size_t len
)
121 const char *trun
= system_dirs
;
123 for (size_t idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
125 if (len
== system_dirs_len
[idx
] && memcmp (trun
, path
, len
) == 0)
129 trun
+= system_dirs_len
[idx
] + 1;
137 is_trusted_path_normalize (const char *path
, size_t len
)
148 char *npath
= (char *) alloca (len
+ 2);
150 while (*path
!= '\0')
156 if (path
[2] == '.' && (path
[3] == '/' || path
[3] == '\0'))
158 while (wnp
> npath
&& *--wnp
!= '/')
163 else if (path
[2] == '/' || path
[2] == '\0')
170 if (wnp
> npath
&& wnp
[-1] == '/')
180 if (wnp
== npath
|| wnp
[-1] != '/')
183 const char *trun
= system_dirs
;
185 for (size_t idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
187 if (wnp
- npath
>= system_dirs_len
[idx
]
188 && memcmp (trun
, npath
, system_dirs_len
[idx
]) == 0)
192 trun
+= system_dirs_len
[idx
] + 1;
200 is_dst (const char *start
, const char *name
, const char *str
,
201 int is_path
, int secure
)
204 bool is_curly
= false;
213 while (name
[len
] == str
[len
] && name
[len
] != '\0')
218 if (name
[len
] != '}')
221 /* Point again at the beginning of the name. */
223 /* Skip over closing curly brace and adjust for the --name. */
226 else if (name
[len
] != '\0' && name
[len
] != '/'
227 && (!is_path
|| name
[len
] != ':'))
230 if (__glibc_unlikely (secure
)
231 && ((name
[len
] != '\0' && name
[len
] != '/'
232 && (!is_path
|| name
[len
] != ':'))
233 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
241 _dl_dst_count (const char *name
, int is_path
)
243 const char *const start
= name
;
250 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
251 is $ORIGIN alone) and it must always appear first in path. */
253 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
254 __libc_enable_secure
)) != 0
255 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
256 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
259 name
= strchr (name
+ len
, '$');
261 while (name
!= NULL
);
268 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
271 const char *const start
= name
;
273 /* Now fill the result path. While copying over the string we keep
274 track of the start of the last path element. When we come across
275 a DST we copy over the value or (if the value is not available)
276 leave the entire path element out. */
278 char *last_elem
= result
;
279 bool check_for_trusted
= false;
283 if (__glibc_unlikely (*name
== '$'))
285 const char *repl
= NULL
;
289 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
290 __libc_enable_secure
)) != 0)
293 check_for_trusted
= (__libc_enable_secure
294 && l
->l_type
== lt_executable
);
296 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
297 repl
= GLRO(dl_platform
);
298 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
301 if (repl
!= NULL
&& repl
!= (const char *) -1)
303 wp
= __stpcpy (wp
, repl
);
308 /* We cannot use this path element, the value of the
309 replacement is unknown. */
312 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
314 /* Also skip following colon if this is the first rpath
315 element, but keep an empty element at the end. */
316 if (wp
== result
&& is_path
&& *name
== ':' && name
[1] != '\0')
320 /* No DST we recognize. */
326 if (is_path
&& *name
== ':')
328 /* In SUID/SGID programs, after $ORIGIN expansion the
329 normalized path must be rooted in one of the trusted
331 if (__glibc_unlikely (check_for_trusted
)
332 && !is_trusted_path_normalize (last_elem
, wp
- last_elem
))
337 check_for_trusted
= false;
341 while (*name
!= '\0');
343 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
344 path must be rooted in one of the trusted directories. */
345 if (__glibc_unlikely (check_for_trusted
)
346 && !is_trusted_path_normalize (last_elem
, wp
- last_elem
))
355 /* Return copy of argument with all recognized dynamic string tokens
356 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
357 might not be possible to determine the path from which the object
358 belonging to the map is loaded. In this case the path element
359 containing $ORIGIN is left out. */
361 expand_dynamic_string_token (struct link_map
*l
, const char *s
, int is_path
)
363 /* We make two runs over the string. First we determine how large the
364 resulting string is and then we copy it over. Since this is no
365 frequently executed operation we are looking here not for performance
366 but rather for code size. */
371 /* Determine the number of DST elements. */
372 cnt
= DL_DST_COUNT (s
, is_path
);
374 /* If we do not have to replace anything simply copy the string. */
375 if (__glibc_likely (cnt
== 0))
378 /* Determine the length of the substituted string. */
379 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
381 /* Allocate the necessary memory. */
382 result
= (char *) malloc (total
+ 1);
386 return _dl_dst_substitute (l
, s
, result
, is_path
);
390 /* Add `name' to the list of names for a particular shared object.
391 `name' is expected to have been allocated with malloc and will
392 be freed if the shared object already has this name.
393 Returns false if the object already had this name. */
395 add_name_to_object (struct link_map
*l
, const char *name
)
397 struct libname_list
*lnp
, *lastp
;
398 struct libname_list
*newname
;
402 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
403 if (strcmp (name
, lnp
->name
) == 0)
406 name_len
= strlen (name
) + 1;
407 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
410 /* No more memory. */
411 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
414 /* The object should have a libname set from _dl_new_object. */
415 assert (lastp
!= NULL
);
417 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
418 newname
->next
= NULL
;
419 newname
->dont_free
= 0;
420 lastp
->next
= newname
;
423 /* Standard search directories. */
424 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
426 static size_t max_dirnamelen
;
428 static struct r_search_path_elem
**
429 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
430 int check_trusted
, const char *what
, const char *where
,
437 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
439 struct r_search_path_elem
*dirp
;
441 to_free
= cp
= expand_dynamic_string_token (l
, cp
, 1);
443 size_t len
= strlen (cp
);
445 /* `strsep' can pass an empty string. This has to be
446 interpreted as `use the current directory'. */
449 static const char curwd
[] = "./";
453 /* Remove trailing slashes (except for "/"). */
454 while (len
> 1 && cp
[len
- 1] == '/')
457 /* Now add one if there is none so far. */
458 if (len
> 0 && cp
[len
- 1] != '/')
461 /* Make sure we don't use untrusted directories if we run SUID. */
462 if (__glibc_unlikely (check_trusted
) && !is_trusted_path (cp
, len
))
468 /* See if this directory is already known. */
469 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
470 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
475 /* It is available, see whether it's on our own list. */
477 for (cnt
= 0; cnt
< nelems
; ++cnt
)
478 if (result
[cnt
] == dirp
)
482 result
[nelems
++] = dirp
;
487 enum r_dir_status init_val
;
488 size_t where_len
= where
? strlen (where
) + 1 : 0;
490 /* It's a new directory. Create an entry and add it. */
491 dirp
= (struct r_search_path_elem
*)
492 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
493 + where_len
+ len
+ 1);
495 _dl_signal_error (ENOMEM
, NULL
, NULL
,
496 N_("cannot create cache for search path"));
498 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
499 + ncapstr
* sizeof (enum r_dir_status
));
500 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
501 dirp
->dirnamelen
= len
;
503 if (len
> max_dirnamelen
)
504 max_dirnamelen
= len
;
506 /* We have to make sure all the relative directories are
507 never ignored. The current directory might change and
508 all our saved information would be void. */
509 init_val
= cp
[0] != '/' ? existing
: unknown
;
510 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
511 dirp
->status
[cnt
] = init_val
;
514 if (__glibc_likely (where
!= NULL
))
515 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
516 + (ncapstr
* sizeof (enum r_dir_status
)),
521 dirp
->next
= GL(dl_all_dirs
);
522 GL(dl_all_dirs
) = dirp
;
524 /* Put it in the result array. */
525 result
[nelems
++] = dirp
;
530 /* Terminate the array. */
531 result
[nelems
] = NULL
;
538 decompose_rpath (struct r_search_path_struct
*sps
,
539 const char *rpath
, struct link_map
*l
, const char *what
)
541 /* Make a copy we can work with. */
542 const char *where
= l
->l_name
;
545 struct r_search_path_elem
**result
;
547 /* Initialize to please the compiler. */
548 const char *errstring
= NULL
;
550 /* First see whether we must forget the RUNPATH and RPATH from this
552 if (__glibc_unlikely (GLRO(dl_inhibit_rpath
) != NULL
)
553 && !__libc_enable_secure
)
555 const char *inhp
= GLRO(dl_inhibit_rpath
);
559 const char *wp
= where
;
561 while (*inhp
== *wp
&& *wp
!= '\0')
567 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
569 /* This object is on the list of objects for which the
570 RUNPATH and RPATH must not be used. */
571 sps
->dirs
= (void *) -1;
575 while (*inhp
!= '\0')
579 while (*inhp
!= '\0');
582 /* Make a writable copy. */
583 copy
= __strdup (rpath
);
586 errstring
= N_("cannot create RUNPATH/RPATH copy");
590 /* Ignore empty rpaths. */
594 sps
->dirs
= (struct r_search_path_elem
**) -1;
598 /* Count the number of necessary elements in the result array. */
600 for (cp
= copy
; *cp
!= '\0'; ++cp
)
604 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
605 number of necessary entries. */
606 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
611 errstring
= N_("cannot create cache for search path");
613 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
616 fillin_rpath (copy
, result
, ":", 0, what
, where
, l
);
618 /* Free the copied RPATH string. `fillin_rpath' make own copies if
623 /* The caller will change this value if we haven't used a real malloc. */
628 /* Make sure cached path information is stored in *SP
629 and return true if there are any paths to search there. */
631 cache_rpath (struct link_map
*l
,
632 struct r_search_path_struct
*sp
,
636 if (sp
->dirs
== (void *) -1)
639 if (sp
->dirs
!= NULL
)
642 if (l
->l_info
[tag
] == NULL
)
644 /* There is no path. */
645 sp
->dirs
= (void *) -1;
649 /* Make sure the cache information is available. */
650 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
651 + l
->l_info
[tag
]->d_un
.d_val
),
657 _dl_init_paths (const char *llp
)
661 struct r_search_path_elem
*pelem
, **aelem
;
663 struct link_map
__attribute__ ((unused
)) *l
= NULL
;
664 /* Initialize to please the compiler. */
665 const char *errstring
= NULL
;
667 /* Fill in the information about the application's RPATH and the
668 directories addressed by the LD_LIBRARY_PATH environment variable. */
670 /* Get the capabilities. */
671 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
672 &ncapstr
, &max_capstrlen
);
674 /* First set up the rest of the default search directory entries. */
675 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
676 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
677 if (rtld_search_dirs
.dirs
== NULL
)
679 errstring
= N_("cannot create search path array");
681 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
684 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
685 + ncapstr
* sizeof (enum r_dir_status
))
686 / sizeof (struct r_search_path_elem
));
688 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
689 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
690 * round_size
* sizeof (struct r_search_path_elem
));
691 if (rtld_search_dirs
.dirs
[0] == NULL
)
693 errstring
= N_("cannot create cache for search path");
697 rtld_search_dirs
.malloced
= 0;
698 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
708 pelem
->what
= "system search path";
711 pelem
->dirname
= strp
;
712 pelem
->dirnamelen
= system_dirs_len
[idx
];
713 strp
+= system_dirs_len
[idx
] + 1;
715 /* System paths must be absolute. */
716 assert (pelem
->dirname
[0] == '/');
717 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
718 pelem
->status
[cnt
] = unknown
;
720 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
724 while (idx
< nsystem_dirs_len
);
726 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
730 /* This points to the map of the main object. */
731 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
734 assert (l
->l_type
!= lt_loaded
);
736 if (l
->l_info
[DT_RUNPATH
])
738 /* Allocate room for the search path and fill in information
740 decompose_rpath (&l
->l_runpath_dirs
,
741 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
742 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
744 /* During rtld init the memory is allocated by the stub malloc,
745 prevent any attempt to free it by the normal malloc. */
746 l
->l_runpath_dirs
.malloced
= 0;
748 /* The RPATH is ignored. */
749 l
->l_rpath_dirs
.dirs
= (void *) -1;
753 l
->l_runpath_dirs
.dirs
= (void *) -1;
755 if (l
->l_info
[DT_RPATH
])
757 /* Allocate room for the search path and fill in information
759 decompose_rpath (&l
->l_rpath_dirs
,
760 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
761 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
763 /* During rtld init the memory is allocated by the stub
764 malloc, prevent any attempt to free it by the normal
766 l
->l_rpath_dirs
.malloced
= 0;
769 l
->l_rpath_dirs
.dirs
= (void *) -1;
774 if (llp
!= NULL
&& *llp
!= '\0')
777 const char *cp
= llp
;
782 size_t cnt
= DL_DST_COUNT (llp
, 1);
783 if (__glibc_likely (cnt
== 0))
784 llp_tmp
= strdupa (llp
);
787 /* Determine the length of the substituted string. */
788 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
790 /* Allocate the necessary memory. */
791 llp_tmp
= (char *) alloca (total
+ 1);
792 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
795 llp_tmp
= strdupa (llp
);
798 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
803 if (*cp
== ':' || *cp
== ';')
808 env_path_list
.dirs
= (struct r_search_path_elem
**)
809 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
810 if (env_path_list
.dirs
== NULL
)
812 errstring
= N_("cannot create cache for search path");
816 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
817 __libc_enable_secure
, "LD_LIBRARY_PATH",
820 if (env_path_list
.dirs
[0] == NULL
)
822 free (env_path_list
.dirs
);
823 env_path_list
.dirs
= (void *) -1;
826 env_path_list
.malloced
= 0;
829 env_path_list
.dirs
= (void *) -1;
834 __attribute__ ((noreturn
, noinline
))
835 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
836 const char *msg
, struct r_debug
*r
, Lmid_t nsid
)
838 /* The file might already be closed. */
841 if (l
!= NULL
&& l
->l_origin
!= (char *) -1l)
842 free ((char *) l
->l_origin
);
848 r
->r_state
= RT_CONSISTENT
;
850 LIBC_PROBE (map_failed
, 2, nsid
, r
);
853 _dl_signal_error (code
, name
, NULL
, msg
);
857 /* Map in the shared object NAME, actually located in REALNAME, and already
860 #ifndef EXTERNAL_MAP_FROM_FD
864 _dl_map_object_from_fd (const char *name
, const char *origname
, int fd
,
865 struct filebuf
*fbp
, char *realname
,
866 struct link_map
*loader
, int l_type
, int mode
,
867 void **stack_endp
, Lmid_t nsid
)
869 struct link_map
*l
= NULL
;
870 const ElfW(Ehdr
) *header
;
871 const ElfW(Phdr
) *phdr
;
872 const ElfW(Phdr
) *ph
;
875 /* Initialize to keep the compiler happy. */
876 const char *errstring
= NULL
;
878 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
879 bool make_consistent
= false;
881 /* Get file information. */
883 if (__glibc_unlikely (!_dl_get_file_id (fd
, &id
)))
885 errstring
= N_("cannot stat shared object");
889 lose (errval
, fd
, name
, realname
, l
, errstring
,
890 make_consistent
? r
: NULL
, nsid
);
893 /* Look again to see if the real name matched another already loaded. */
894 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
!= NULL
; l
= l
->l_next
)
895 if (!l
->l_removed
&& _dl_file_id_match_p (&l
->l_file_id
, &id
))
897 /* The object is already loaded.
898 Just bump its reference count and return it. */
901 /* If the name is not in the list of names for this object add
904 add_name_to_object (l
, name
);
910 /* When loading into a namespace other than the base one we must
911 avoid loading ld.so since there can only be one copy. Ever. */
912 if (__glibc_unlikely (nsid
!= LM_ID_BASE
)
913 && (_dl_file_id_match_p (&id
, &GL(dl_rtld_map
).l_file_id
)
914 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
916 /* This is indeed ld.so. Create a new link_map which refers to
917 the real one for almost everything. */
918 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
922 /* Refer to the real descriptor. */
923 l
->l_real
= &GL(dl_rtld_map
);
925 /* No need to bump the refcount of the real object, ld.so will
926 never be unloaded. */
929 /* Add the map for the mirrored object to the object list. */
930 _dl_add_to_namespace_list (l
, nsid
);
936 if (mode
& RTLD_NOLOAD
)
938 /* We are not supposed to load the object unless it is already
939 loaded. So return now. */
945 /* Print debugging message. */
946 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
947 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
949 /* This is the ELF header. We read it in `open_verify'. */
950 header
= (void *) fbp
->buf
;
954 if (_dl_zerofd
== -1)
956 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
957 if (_dl_zerofd
== -1)
961 _dl_signal_error (errno
, NULL
, NULL
,
962 N_("cannot open zero fill device"));
967 /* Signal that we are going to add new objects. */
968 if (r
->r_state
== RT_CONSISTENT
)
971 /* Auditing checkpoint: we are going to add new objects. */
972 if ((mode
& __RTLD_AUDIT
) == 0
973 && __glibc_unlikely (GLRO(dl_naudit
) > 0))
975 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
976 /* Do not call the functions for any auditing object. */
977 if (head
->l_auditing
== 0)
979 struct audit_ifaces
*afct
= GLRO(dl_audit
);
980 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
982 if (afct
->activity
!= NULL
)
983 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
991 /* Notify the debugger we have added some objects. We need to
992 call _dl_debug_initialize in a static program in case dynamic
993 linking has not been used before. */
996 LIBC_PROBE (map_start
, 2, nsid
, r
);
997 make_consistent
= true;
1000 assert (r
->r_state
== RT_ADD
);
1002 /* Enter the new object in the list of loaded objects. */
1003 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
1004 if (__glibc_unlikely (l
== NULL
))
1009 errstring
= N_("cannot create shared object descriptor");
1010 goto call_lose_errno
;
1013 /* Extract the remaining details we need from the ELF header
1014 and then read in the program header table. */
1015 l
->l_entry
= header
->e_entry
;
1016 type
= header
->e_type
;
1017 l
->l_phnum
= header
->e_phnum
;
1019 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
1020 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1021 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
1024 phdr
= alloca (maplength
);
1025 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
1026 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1028 errstring
= N_("cannot read file data");
1029 goto call_lose_errno
;
1033 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
1034 * executable. Other platforms default to a nonexecutable stack and don't
1035 * need PT_GNU_STACK to do so. */
1036 uint_fast16_t stack_flags
= DEFAULT_STACK_PERMS
;
1039 /* Scan the program header table, collecting its load commands. */
1040 struct loadcmd loadcmds
[l
->l_phnum
];
1041 size_t nloadcmds
= 0;
1042 bool has_holes
= false;
1044 /* The struct is initialized to zero so this is not necessary:
1048 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1051 /* These entries tell us where to find things once the file's
1052 segments are mapped in. We record the addresses it says
1053 verbatim, and later correct for the run-time load address. */
1055 l
->l_ld
= (void *) ph
->p_vaddr
;
1056 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1060 l
->l_phdr
= (void *) ph
->p_vaddr
;
1064 /* A load command tells us to map in part of the file.
1065 We record the load commands and process them all later. */
1066 if (__glibc_unlikely ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0))
1068 errstring
= N_("ELF load command alignment not page-aligned");
1071 if (__glibc_unlikely (((ph
->p_vaddr
- ph
->p_offset
)
1072 & (ph
->p_align
- 1)) != 0))
1075 = N_("ELF load command address/offset not properly aligned");
1079 struct loadcmd
*c
= &loadcmds
[nloadcmds
++];
1080 c
->mapstart
= ALIGN_DOWN (ph
->p_vaddr
, GLRO(dl_pagesize
));
1081 c
->mapend
= ALIGN_UP (ph
->p_vaddr
+ ph
->p_filesz
, GLRO(dl_pagesize
));
1082 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1083 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1084 c
->mapoff
= ALIGN_DOWN (ph
->p_offset
, GLRO(dl_pagesize
));
1086 /* Determine whether there is a gap between the last segment
1088 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1091 /* Optimize a common case. */
1092 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1093 c
->prot
= (PF_TO_PROT
1094 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1097 if (ph
->p_flags
& PF_R
)
1098 c
->prot
|= PROT_READ
;
1099 if (ph
->p_flags
& PF_W
)
1100 c
->prot
|= PROT_WRITE
;
1101 if (ph
->p_flags
& PF_X
)
1102 c
->prot
|= PROT_EXEC
;
1107 if (ph
->p_memsz
== 0)
1108 /* Nothing to do for an empty segment. */
1111 l
->l_tls_blocksize
= ph
->p_memsz
;
1112 l
->l_tls_align
= ph
->p_align
;
1113 if (ph
->p_align
== 0)
1114 l
->l_tls_firstbyte_offset
= 0;
1116 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1117 l
->l_tls_initimage_size
= ph
->p_filesz
;
1118 /* Since we don't know the load address yet only store the
1119 offset. We will adjust it later. */
1120 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1122 /* If not loading the initial set of shared libraries,
1123 check whether we should permit loading a TLS segment. */
1124 if (__glibc_likely (l
->l_type
== lt_library
)
1125 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1126 not set up TLS data structures, so don't use them now. */
1127 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list
) != NULL
))
1129 /* Assign the next available module ID. */
1130 l
->l_tls_modid
= _dl_next_tls_modid ();
1135 /* We are loading the executable itself when the dynamic
1136 linker was executed directly. The setup will happen
1137 later. Otherwise, the TLS data structures are already
1138 initialized, and we assigned a TLS modid above. */
1139 assert (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0);
1141 assert (false && "TLS not initialized in static application");
1146 stack_flags
= ph
->p_flags
;
1150 l
->l_relro_addr
= ph
->p_vaddr
;
1151 l
->l_relro_size
= ph
->p_memsz
;
1155 if (__glibc_unlikely (nloadcmds
== 0))
1157 /* This only happens for a bogus object that will be caught with
1158 another error below. But we don't want to go through the
1159 calculations below using NLOADCMDS - 1. */
1160 errstring
= N_("object file has no loadable segments");
1164 if (__glibc_unlikely (type
!= ET_DYN
)
1165 && __glibc_unlikely ((mode
& __RTLD_OPENEXEC
) == 0))
1167 /* This object is loaded at a fixed address. This must never
1168 happen for objects loaded with dlopen. */
1169 errstring
= N_("cannot dynamically load executable");
1173 /* Length of the sections to be loaded. */
1174 maplength
= loadcmds
[nloadcmds
- 1].allocend
- loadcmds
[0].mapstart
;
1176 /* Now process the load commands and map segments into memory.
1177 This is responsible for filling in:
1178 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1180 errstring
= _dl_map_segments (l
, fd
, header
, type
, loadcmds
, nloadcmds
,
1181 maplength
, has_holes
, loader
);
1182 if (__glibc_unlikely (errstring
!= NULL
))
1188 if (__glibc_unlikely (type
== ET_DYN
))
1190 errstring
= N_("object file has no dynamic section");
1195 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1197 elf_get_dynamic_info (l
, NULL
);
1199 /* Make sure we are not dlopen'ing an object that has the
1200 DF_1_NOOPEN flag set. */
1201 if (__glibc_unlikely (l
->l_flags_1
& DF_1_NOOPEN
)
1202 && (mode
& __RTLD_DLOPEN
))
1204 /* We are not supposed to load this object. Free all resources. */
1205 _dl_unmap_segments (l
);
1207 if (!l
->l_libname
->dont_free
)
1208 free (l
->l_libname
);
1210 if (l
->l_phdr_allocated
)
1211 free ((void *) l
->l_phdr
);
1213 errstring
= N_("shared object cannot be dlopen()ed");
1217 if (l
->l_phdr
== NULL
)
1219 /* The program header is not contained in any of the segments.
1220 We have to allocate memory ourself and copy it over from out
1222 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1223 * sizeof (ElfW(Phdr
)));
1226 errstring
= N_("cannot allocate memory for program header");
1227 goto call_lose_errno
;
1230 l
->l_phdr
= memcpy (newp
, phdr
,
1231 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1232 l
->l_phdr_allocated
= 1;
1235 /* Adjust the PT_PHDR value by the runtime load address. */
1236 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1238 if (__glibc_unlikely ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
))
1240 if (__glibc_unlikely (__check_caller (RETURN_ADDRESS (0), allow_ldso
) != 0))
1242 errstring
= N_("invalid caller");
1246 /* The stack is presently not executable, but this module
1247 requires that it be executable. We must change the
1248 protection of the variable which contains the flags used in
1249 the mprotect calls. */
1251 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1253 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1254 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1256 struct link_map
*const m
= &GL(dl_rtld_map
);
1257 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1259 & -GLRO(dl_pagesize
));
1260 if (__glibc_likely (p
+ s
<= relro_end
))
1262 /* The variable lies in the region protected by RELRO. */
1263 if (__mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
) < 0)
1265 errstring
= N_("cannot change memory protections");
1266 goto call_lose_errno
;
1268 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1269 __mprotect ((void *) p
, s
, PROT_READ
);
1272 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1276 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1278 #ifdef check_consistency
1279 check_consistency ();
1282 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1286 cannot enable executable stack as shared object requires");
1291 /* Adjust the address of the TLS initialization image. */
1292 if (l
->l_tls_initimage
!= NULL
)
1293 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1295 /* We are done mapping in the file. We no longer need the descriptor. */
1296 if (__glibc_unlikely (__close (fd
) != 0))
1298 errstring
= N_("cannot close file descriptor");
1299 goto call_lose_errno
;
1301 /* Signal that we closed the file. */
1304 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1305 assert (type
!= ET_EXEC
|| l
->l_type
== lt_executable
);
1307 l
->l_entry
+= l
->l_addr
;
1309 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
1310 _dl_debug_printf ("\
1311 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1312 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1313 (int) sizeof (void *) * 2,
1314 (unsigned long int) l
->l_ld
,
1315 (int) sizeof (void *) * 2,
1316 (unsigned long int) l
->l_addr
,
1317 (int) sizeof (void *) * 2, maplength
,
1318 (int) sizeof (void *) * 2,
1319 (unsigned long int) l
->l_entry
,
1320 (int) sizeof (void *) * 2,
1321 (unsigned long int) l
->l_phdr
,
1322 (int) sizeof (void *) * 2, l
->l_phnum
);
1324 /* Set up the symbol hash table. */
1327 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1328 have to do this for the main map. */
1329 if ((mode
& RTLD_DEEPBIND
) == 0
1330 && __glibc_unlikely (l
->l_info
[DT_SYMBOLIC
] != NULL
)
1331 && &l
->l_searchlist
!= l
->l_scope
[0])
1333 /* Create an appropriate searchlist. It contains only this map.
1334 This is the definition of DT_SYMBOLIC in SysVr4. */
1335 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1336 l
->l_symbolic_searchlist
.r_nlist
= 1;
1338 /* Now move the existing entries one back. */
1339 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1340 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1342 /* Now add the new entry. */
1343 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1346 /* Remember whether this object must be initialized first. */
1347 if (l
->l_flags_1
& DF_1_INITFIRST
)
1348 GL(dl_initfirst
) = l
;
1350 /* Finally the file information. */
1354 /* When auditing is used the recorded names might not include the
1355 name by which the DSO is actually known. Add that as well. */
1356 if (__glibc_unlikely (origname
!= NULL
))
1357 add_name_to_object (l
, origname
);
1359 /* Audit modules only exist when linking is dynamic so ORIGNAME
1360 cannot be non-NULL. */
1361 assert (origname
== NULL
);
1364 /* When we profile the SONAME might be needed for something else but
1365 loading. Add it right away. */
1366 if (__glibc_unlikely (GLRO(dl_profile
) != NULL
)
1367 && l
->l_info
[DT_SONAME
] != NULL
)
1368 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1369 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1371 #ifdef DL_AFTER_LOAD
1375 /* Now that the object is fully initialized add it to the object list. */
1376 _dl_add_to_namespace_list (l
, nsid
);
1379 /* Auditing checkpoint: we have a new object. */
1380 if (__glibc_unlikely (GLRO(dl_naudit
) > 0)
1381 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1383 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1384 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1386 if (afct
->objopen
!= NULL
)
1388 l
->l_audit
[cnt
].bindflags
1389 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1391 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1402 /* Print search path. */
1404 print_search_path (struct r_search_path_elem
**list
,
1405 const char *what
, const char *name
)
1407 char buf
[max_dirnamelen
+ max_capstrlen
];
1410 _dl_debug_printf (" search path=");
1412 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1414 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
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] == '/'))
1426 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1434 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1435 DSO_FILENAME (name
));
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.
1446 If FD is not -1, then the file is already open and FD refers to it.
1447 In that case, FD is consumed for both successful and error returns. */
1449 open_verify (const char *name
, int fd
,
1450 struct filebuf
*fbp
, struct link_map
*loader
,
1451 int whatcode
, int mode
, bool *found_other_class
, bool free_name
)
1453 /* This is the expected ELF header. */
1454 #define ELF32_CLASS ELFCLASS32
1455 #define ELF64_CLASS ELFCLASS64
1456 #ifndef VALID_ELF_HEADER
1457 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1458 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1459 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1460 #elif defined MORE_ELF_HEADER_DATA
1461 MORE_ELF_HEADER_DATA
;
1463 static const unsigned char expected
[EI_NIDENT
] =
1465 [EI_MAG0
] = ELFMAG0
,
1466 [EI_MAG1
] = ELFMAG1
,
1467 [EI_MAG2
] = ELFMAG2
,
1468 [EI_MAG3
] = ELFMAG3
,
1469 [EI_CLASS
] = ELFW(CLASS
),
1470 [EI_DATA
] = byteorder
,
1471 [EI_VERSION
] = EV_CURRENT
,
1472 [EI_OSABI
] = ELFOSABI_SYSV
,
1477 ElfW(Word
) vendorlen
;
1481 } expected_note
= { 4, 16, 1, "GNU" };
1482 /* Initialize it to make the compiler happy. */
1483 const char *errstring
= NULL
;
1487 /* Give the auditing libraries a chance. */
1488 if (__glibc_unlikely (GLRO(dl_naudit
) > 0) && whatcode
!= 0
1489 && loader
->l_auditing
== 0)
1491 const char *original_name
= name
;
1492 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1493 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1495 if (afct
->objsearch
!= NULL
)
1497 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1500 /* Ignore the path. */
1507 if (fd
!= -1 && name
!= original_name
&& strcmp (name
, original_name
))
1509 /* An audit library changed what we're supposed to open,
1510 so FD no longer matches it. */
1518 /* Open the file. We always open files read-only. */
1519 fd
= __open (name
, O_RDONLY
| O_CLOEXEC
);
1524 ElfW(Phdr
) *phdr
, *ph
;
1525 ElfW(Word
) *abi_note
;
1526 unsigned int osversion
;
1529 /* We successfully opened the file. Now verify it is a file
1533 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1534 /* Read in the header. */
1537 ssize_t retlen
= __libc_read (fd
, fbp
->buf
+ fbp
->len
,
1538 sizeof (fbp
->buf
) - fbp
->len
);
1543 while (__glibc_unlikely (fbp
->len
< sizeof (ElfW(Ehdr
))));
1545 /* This is where the ELF header is loaded. */
1546 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1548 /* Now run the tests. */
1549 if (__glibc_unlikely (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
))))
1552 errstring
= (errval
== 0
1553 ? N_("file too short") : N_("cannot read file data"));
1557 char *realname
= (char *) name
;
1558 name
= strdupa (realname
);
1561 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
, 0);
1564 /* See whether the ELF header is what we expect. */
1565 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1567 || !VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1568 ehdr
->e_ident
[EI_ABIVERSION
])
1569 || memcmp (&ehdr
->e_ident
[EI_PAD
],
1571 EI_NIDENT
- EI_PAD
) != 0))
1573 /* Something is wrong. */
1574 const Elf32_Word
*magp
= (const void *) ehdr
->e_ident
;
1576 #if BYTE_ORDER == LITTLE_ENDIAN
1577 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1578 (ELFMAG1
<< (EI_MAG1
* 8)) |
1579 (ELFMAG2
<< (EI_MAG2
* 8)) |
1580 (ELFMAG3
<< (EI_MAG3
* 8)))
1582 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1583 (ELFMAG1
<< (EI_MAG2
* 8)) |
1584 (ELFMAG2
<< (EI_MAG1
* 8)) |
1585 (ELFMAG3
<< (EI_MAG0
* 8)))
1588 errstring
= N_("invalid ELF header");
1589 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1591 /* This is not a fatal error. On architectures where
1592 32-bit and 64-bit binaries can be run this might
1594 *found_other_class
= true;
1597 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1599 if (BYTE_ORDER
== BIG_ENDIAN
)
1600 errstring
= N_("ELF file data encoding not big-endian");
1602 errstring
= N_("ELF file data encoding not little-endian");
1604 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1606 = N_("ELF file version ident does not match current one");
1607 /* XXX We should be able so set system specific versions which are
1609 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1610 errstring
= N_("ELF file OS ABI invalid");
1611 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1612 ehdr
->e_ident
[EI_ABIVERSION
]))
1613 errstring
= N_("ELF file ABI version invalid");
1614 else if (memcmp (&ehdr
->e_ident
[EI_PAD
], &expected
[EI_PAD
],
1615 EI_NIDENT
- EI_PAD
) != 0)
1616 errstring
= N_("nonzero padding in e_ident");
1618 /* Otherwise we don't know what went wrong. */
1619 errstring
= N_("internal error");
1624 if (__glibc_unlikely (ehdr
->e_version
!= EV_CURRENT
))
1626 errstring
= N_("ELF file version does not match current one");
1629 if (! __glibc_likely (elf_machine_matches_host (ehdr
)))
1631 else if (__glibc_unlikely (ehdr
->e_type
!= ET_DYN
1632 && ehdr
->e_type
!= ET_EXEC
))
1634 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1637 else if (__glibc_unlikely (ehdr
->e_type
== ET_EXEC
1638 && (mode
& __RTLD_OPENEXEC
) == 0))
1640 /* BZ #16634. It is an error to dlopen ET_EXEC (unless
1641 __RTLD_OPENEXEC is explicitly set). We return error here
1642 so that code in _dl_map_object_from_fd does not try to set
1643 l_tls_modid for this module. */
1645 errstring
= N_("cannot dynamically load executable");
1648 else if (__glibc_unlikely (ehdr
->e_phentsize
!= sizeof (ElfW(Phdr
))))
1650 errstring
= N_("ELF file's phentsize not the expected size");
1654 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1655 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1656 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1659 phdr
= alloca (maplength
);
1660 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1661 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1665 errstring
= N_("cannot read file data");
1670 if (__glibc_unlikely (elf_machine_reject_phdr_p
1671 (phdr
, ehdr
->e_phnum
, fbp
->buf
, fbp
->len
,
1675 /* Check .note.ABI-tag if present. */
1676 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1677 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1679 ElfW(Addr
) size
= ph
->p_filesz
;
1681 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1682 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1685 abi_note
= alloca (size
);
1686 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1687 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1691 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1693 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1694 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1695 + ROUND (abi_note
[0])
1696 + ROUND (abi_note
[1]);
1698 if (size
- 32 < note_size
)
1704 abi_note
= (void *) abi_note
+ note_size
;
1710 osversion
= (abi_note
[5] & 0xff) * 65536
1711 + (abi_note
[6] & 0xff) * 256
1712 + (abi_note
[7] & 0xff);
1713 if (abi_note
[4] != __ABI_TAG_OS
1714 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1718 __set_errno (ENOENT
);
1729 /* Try to open NAME in one of the directories in *DIRSP.
1730 Return the fd, or -1. If successful, fill in *REALNAME
1731 with the malloc'd full directory name. If it turns out
1732 that none of the directories in *DIRSP exists, *DIRSP is
1733 replaced with (void *) -1, and the old value is free()d
1734 if MAY_FREE_DIRS is true. */
1737 open_path (const char *name
, size_t namelen
, int mode
,
1738 struct r_search_path_struct
*sps
, char **realname
,
1739 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1740 bool *found_other_class
)
1742 struct r_search_path_elem
**dirs
= sps
->dirs
;
1745 const char *current_what
= NULL
;
1748 if (__glibc_unlikely (dirs
== NULL
))
1749 /* We're called before _dl_init_paths when loading the main executable
1750 given on the command line when rtld is run directly. */
1753 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1756 struct r_search_path_elem
*this_dir
= *dirs
;
1763 /* If we are debugging the search for libraries print the path
1764 now if it hasn't happened now. */
1765 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
)
1766 && current_what
!= this_dir
->what
)
1768 current_what
= this_dir
->what
;
1769 print_search_path (dirs
, current_what
, this_dir
->where
);
1772 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1773 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1775 /* Skip this directory if we know it does not exist. */
1776 if (this_dir
->status
[cnt
] == nonexisting
)
1780 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1785 /* Print name we try if this is wanted. */
1786 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
1787 _dl_debug_printf (" trying file=%s\n", buf
);
1789 fd
= open_verify (buf
, -1, fbp
, loader
, whatcode
, mode
,
1790 found_other_class
, false);
1791 if (this_dir
->status
[cnt
] == unknown
)
1794 this_dir
->status
[cnt
] = existing
;
1795 /* Do not update the directory information when loading
1796 auditing code. We must try to disturb the program as
1797 little as possible. */
1798 else if (loader
== NULL
1799 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1801 /* We failed to open machine dependent library. Let's
1802 test whether there is any directory at all. */
1805 buf
[buflen
- namelen
- 1] = '\0';
1807 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1808 || ! S_ISDIR (st
.st_mode
))
1809 /* The directory does not exist or it is no directory. */
1810 this_dir
->status
[cnt
] = nonexisting
;
1812 this_dir
->status
[cnt
] = existing
;
1816 /* Remember whether we found any existing directory. */
1817 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1819 if (fd
!= -1 && __glibc_unlikely (mode
& __RTLD_SECURE
)
1820 && __libc_enable_secure
)
1822 /* This is an extra security effort to make sure nobody can
1823 preload broken shared objects which are in the trusted
1824 directories and so exploit the bugs. */
1827 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1828 || (st
.st_mode
& S_ISUID
) == 0)
1830 /* The shared object cannot be tested for being SUID
1831 or this bit is not set. In this case we must not
1835 /* We simply ignore the file, signal this by setting
1836 the error value which would have been set by `open'. */
1844 *realname
= (char *) malloc (buflen
);
1845 if (*realname
!= NULL
)
1847 memcpy (*realname
, buf
, buflen
);
1852 /* No memory for the name, we certainly won't be able
1853 to load and link it. */
1858 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1859 /* The file exists and is readable, but something went wrong. */
1862 /* Remember whether we found anything. */
1865 while (*++dirs
!= NULL
);
1867 /* Remove the whole path if none of the directories exists. */
1868 if (__glibc_unlikely (! any
))
1870 /* Paths which were allocated using the minimal malloc() in ld.so
1871 must not be freed using the general free() in libc. */
1875 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1876 avoid writing into it. */
1877 if (sps
!= &rtld_search_dirs
&& sps
!= &env_path_list
)
1878 sps
->dirs
= (void *) -1;
1884 /* Map in the shared object file NAME. */
1887 _dl_map_object (struct link_map
*loader
, const char *name
,
1888 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1891 const char *origname
= NULL
;
1898 assert (nsid
< GL(dl_nns
));
1900 /* Look for this name among those already loaded. */
1901 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1903 /* If the requested name matches the soname of a loaded object,
1904 use that object. Elide this check for names that have not
1906 if (__glibc_unlikely ((l
->l_faked
| l
->l_removed
) != 0))
1908 if (!_dl_name_match_p (name
, l
))
1912 if (__glibc_likely (l
->l_soname_added
)
1913 || l
->l_info
[DT_SONAME
] == NULL
)
1916 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1917 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1918 if (strcmp (name
, soname
) != 0)
1921 /* We have a match on a new name -- cache it. */
1922 add_name_to_object (l
, soname
);
1923 l
->l_soname_added
= 1;
1926 /* We have a match. */
1930 /* Display information if we are debugging. */
1931 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
)
1933 _dl_debug_printf ((mode
& __RTLD_CALLMAP
) == 0
1934 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1935 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1936 name
, nsid
, DSO_FILENAME (loader
->l_name
), loader
->l_ns
);
1939 /* Give the auditing libraries a chance to change the name before we
1941 if (__glibc_unlikely (GLRO(dl_naudit
) > 0)
1942 && (loader
== NULL
|| loader
->l_auditing
== 0))
1944 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1945 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1947 if (afct
->objsearch
!= NULL
)
1949 const char *before
= name
;
1950 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1954 /* Do not try anything further. */
1958 if (before
!= name
&& strcmp (before
, name
) != 0)
1960 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
1961 _dl_debug_printf ("audit changed filename %s -> %s\n",
1964 if (origname
== NULL
)
1974 /* Will be true if we found a DSO which is of the other ELF class. */
1975 bool found_other_class
= false;
1977 if (strchr (name
, '/') == NULL
)
1979 /* Search for NAME in several places. */
1981 size_t namelen
= strlen (name
) + 1;
1983 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
1984 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
1988 /* When the object has the RUNPATH information we don't use any
1990 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
1992 /* This is the executable's map (if there is one). Make sure that
1993 we do not look at it twice. */
1994 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1995 bool did_main_map
= false;
1997 /* First try the DT_RPATH of the dependent object that caused NAME
1998 to be loaded. Then that object's dependent, and on up. */
1999 for (l
= loader
; l
; l
= l
->l_loader
)
2000 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2002 fd
= open_path (name
, namelen
, mode
,
2004 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2005 &found_other_class
);
2009 did_main_map
|= l
== main_map
;
2012 /* If dynamically linked, try the DT_RPATH of the executable
2013 itself. NB: we do this for lookups in any namespace. */
2014 if (fd
== -1 && !did_main_map
2015 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2016 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2018 fd
= open_path (name
, namelen
, mode
,
2019 &main_map
->l_rpath_dirs
,
2020 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2021 &found_other_class
);
2024 /* Try the LD_LIBRARY_PATH environment variable. */
2025 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2026 fd
= open_path (name
, namelen
, mode
, &env_path_list
,
2028 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2029 LA_SER_LIBPATH
, &found_other_class
);
2031 /* Look at the RUNPATH information for this binary. */
2032 if (fd
== -1 && loader
!= NULL
2033 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2034 DT_RUNPATH
, "RUNPATH"))
2035 fd
= open_path (name
, namelen
, mode
,
2036 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2037 LA_SER_RUNPATH
, &found_other_class
);
2041 realname
= _dl_sysdep_open_object (name
, namelen
, &fd
);
2042 if (realname
!= NULL
)
2044 fd
= open_verify (realname
, fd
,
2045 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2046 LA_SER_CONFIG
, mode
, &found_other_class
,
2055 && (__glibc_likely ((mode
& __RTLD_SECURE
) == 0)
2056 || ! __libc_enable_secure
)
2057 && __glibc_likely (GLRO(dl_inhibit_cache
) == 0))
2059 /* Check the list of libraries in the file /etc/ld.so.cache,
2060 for compatibility with Linux's ldconfig program. */
2061 char *cached
= _dl_load_cache_lookup (name
);
2065 // XXX Correct to unconditionally default to namespace 0?
2067 ?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
2073 /* If the loader has the DF_1_NODEFLIB flag set we must not
2074 use a cache entry from any of these directories. */
2075 if (__glibc_unlikely (l
->l_flags_1
& DF_1_NODEFLIB
))
2077 const char *dirp
= system_dirs
;
2078 unsigned int cnt
= 0;
2082 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2084 /* The prefix matches. Don't use the entry. */
2090 dirp
+= system_dirs_len
[cnt
] + 1;
2093 while (cnt
< nsystem_dirs_len
);
2098 fd
= open_verify (cached
, -1,
2099 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2100 LA_SER_CONFIG
, mode
, &found_other_class
,
2102 if (__glibc_likely (fd
!= -1))
2111 /* Finally, try the default path. */
2113 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2114 || __glibc_likely (!(l
->l_flags_1
& DF_1_NODEFLIB
)))
2115 && rtld_search_dirs
.dirs
!= (void *) -1)
2116 fd
= open_path (name
, namelen
, mode
, &rtld_search_dirs
,
2117 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2119 /* Add another newline when we are tracing the library loading. */
2120 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
2121 _dl_debug_printf ("\n");
2125 /* The path may contain dynamic string tokens. */
2127 ? expand_dynamic_string_token (loader
, name
, 0)
2129 if (realname
== NULL
)
2133 fd
= open_verify (realname
, -1, &fb
,
2134 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0, mode
,
2135 &found_other_class
, true);
2136 if (__glibc_unlikely (fd
== -1))
2144 /* In case the LOADER information has only been provided to get to
2145 the appropriate RUNPATH/RPATH information we do not need it
2147 if (mode
& __RTLD_CALLMAP
)
2150 if (__glibc_unlikely (fd
== -1))
2153 && __glibc_likely ((GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
) == 0))
2155 /* We haven't found an appropriate library. But since we
2156 are only interested in the list of libraries this isn't
2157 so severe. Fake an entry with all the information we
2159 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2161 /* Allocate a new object map. */
2162 if ((name_copy
= __strdup (name
)) == NULL
2163 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2164 mode
, nsid
)) == NULL
)
2167 _dl_signal_error (ENOMEM
, name
, NULL
,
2168 N_("cannot create shared object descriptor"));
2170 /* Signal that this is a faked entry. */
2172 /* Since the descriptor is initialized with zero we do not
2174 l->l_reserved = 0; */
2175 l
->l_buckets
= &dummy_bucket
;
2179 /* Enter the object in the object list. */
2180 _dl_add_to_namespace_list (l
, nsid
);
2184 else if (found_other_class
)
2185 _dl_signal_error (0, name
, NULL
,
2186 ELFW(CLASS
) == ELFCLASS32
2187 ? N_("wrong ELF class: ELFCLASS64")
2188 : N_("wrong ELF class: ELFCLASS32"));
2190 _dl_signal_error (errno
, name
, NULL
,
2191 N_("cannot open shared object file"));
2194 void *stack_end
= __libc_stack_end
;
2195 return _dl_map_object_from_fd (name
, origname
, fd
, &fb
, realname
, loader
,
2196 type
, mode
, &stack_end
, nsid
);
2199 struct add_path_state
2208 add_path (struct add_path_state
*p
, const struct r_search_path_struct
*sps
,
2211 if (sps
->dirs
!= (void *) -1)
2213 struct r_search_path_elem
**dirs
= sps
->dirs
;
2216 const struct r_search_path_elem
*const r
= *dirs
++;
2220 p
->si
->dls_size
+= MAX (2, r
->dirnamelen
);
2224 Dl_serpath
*const sp
= &p
->si
->dls_serpath
[p
->idx
++];
2225 sp
->dls_name
= p
->allocptr
;
2226 if (r
->dirnamelen
< 2)
2227 *p
->allocptr
++ = r
->dirnamelen
? '/' : '.';
2229 p
->allocptr
= __mempcpy (p
->allocptr
,
2230 r
->dirname
, r
->dirnamelen
- 1);
2231 *p
->allocptr
++ = '\0';
2232 sp
->dls_flags
= flags
;
2235 while (*dirs
!= NULL
);
2240 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2248 struct add_path_state p
=
2250 .counting
= counting
,
2253 .allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
]
2256 # define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2258 /* When the object has the RUNPATH information we don't use any RPATHs. */
2259 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2261 /* First try the DT_RPATH of the dependent object that caused NAME
2262 to be loaded. Then that object's dependent, and on up. */
2264 struct link_map
*l
= loader
;
2267 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2268 add_path (&p
, &l
->l_rpath_dirs
, XXX_RPATH
);
2273 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2274 if (loader
->l_ns
== LM_ID_BASE
)
2276 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2277 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2278 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2279 add_path (&p
, &l
->l_rpath_dirs
, XXX_RPATH
);
2283 /* Try the LD_LIBRARY_PATH environment variable. */
2284 add_path (&p
, &env_path_list
, XXX_ENV
);
2286 /* Look at the RUNPATH information for this binary. */
2287 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2288 add_path (&p
, &loader
->l_runpath_dirs
, XXX_RUNPATH
);
2291 Here is where ld.so.cache gets checked, but we don't have
2292 a way to indicate that in the results for Dl_serinfo. */
2294 /* Finally, try the default path. */
2295 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2296 add_path (&p
, &rtld_search_dirs
, XXX_default
);
2299 /* Count the struct size before the string area, which we didn't
2300 know before we completed dls_cnt. */
2301 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;