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>
40 #include <array_length.h>
44 #include <dl-map-segments.h>
45 #include <dl-unmap-segments.h>
46 #include <dl-machine-reject-phdr.h>
47 #include <dl-sysdep-open.h>
51 #if BYTE_ORDER == BIG_ENDIAN
52 # define byteorder ELFDATA2MSB
53 #elif BYTE_ORDER == LITTLE_ENDIAN
54 # define byteorder ELFDATA2LSB
56 # error "Unknown BYTE_ORDER " BYTE_ORDER
57 # define byteorder ELFDATANONE
60 #define STRING(x) __STRING (x)
63 int __stack_prot attribute_hidden attribute_relro
64 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
66 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
73 /* Type for the buffer we put the ELF header and hopefully the program
74 header. This buffer does not really have to be too large. In most
75 cases the program header follows the ELF header directly. If this
76 is not the case all bets are off and we can make the header
77 arbitrarily large and still won't get it read. This means the only
78 question is how large are the ELF and program header combined. The
79 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
80 bytes long. Each program header entry is again 32 and 56 bytes
81 long respectively. I.e., even with a file which has 10 program
82 header entries we only have to read 372B/624B respectively. Add to
83 this a bit of margin for program notes and reading 512B and 832B
84 for 32-bit and 64-bit files respecitvely is enough. If this
85 heuristic should really fail for some file the code in
86 `_dl_map_object_from_fd' knows how to recover. */
91 # define FILEBUF_SIZE 512
93 # define FILEBUF_SIZE 832
95 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
98 /* This is the decomposed LD_LIBRARY_PATH search path. */
99 static struct r_search_path_struct env_path_list attribute_relro
;
101 /* List of the hardware capabilities we might end up using. */
102 static const struct r_strlenpair
*capstr attribute_relro
;
103 static size_t ncapstr attribute_relro
;
104 static size_t max_capstrlen attribute_relro
;
107 /* Get the generated information about the trusted directories. Use
108 an array of concatenated strings to avoid relocations. See
109 gen-trusted-dirs.awk. */
110 #include "trusted-dirs.h"
112 static const char system_dirs
[] = SYSTEM_DIRS
;
113 static const size_t system_dirs_len
[] =
117 #define nsystem_dirs_len array_length (system_dirs_len)
120 is_trusted_path_normalize (const char *path
, size_t len
)
131 char *npath
= (char *) alloca (len
+ 2);
133 while (*path
!= '\0')
139 if (path
[2] == '.' && (path
[3] == '/' || path
[3] == '\0'))
141 while (wnp
> npath
&& *--wnp
!= '/')
146 else if (path
[2] == '/' || path
[2] == '\0')
153 if (wnp
> npath
&& wnp
[-1] == '/')
163 if (wnp
== npath
|| wnp
[-1] != '/')
166 const char *trun
= system_dirs
;
168 for (size_t idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
170 if (wnp
- npath
>= system_dirs_len
[idx
]
171 && memcmp (trun
, npath
, system_dirs_len
[idx
]) == 0)
175 trun
+= system_dirs_len
[idx
] + 1;
183 is_dst (const char *start
, const char *name
, const char *str
,
184 int is_path
, int secure
)
187 bool is_curly
= false;
196 while (name
[len
] == str
[len
] && name
[len
] != '\0')
201 if (name
[len
] != '}')
204 /* Point again at the beginning of the name. */
206 /* Skip over closing curly brace and adjust for the --name. */
209 else if (name
[len
] != '\0' && name
[len
] != '/'
210 && (!is_path
|| name
[len
] != ':'))
213 if (__glibc_unlikely (secure
)
214 && ((name
[len
] != '\0' && name
[len
] != '/'
215 && (!is_path
|| name
[len
] != ':'))
216 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
224 _dl_dst_count (const char *name
, int is_path
)
226 const char *const start
= name
;
233 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
234 is $ORIGIN alone) and it must always appear first in path. */
236 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
237 __libc_enable_secure
)) != 0
238 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
239 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
242 name
= strchr (name
+ len
, '$');
244 while (name
!= NULL
);
251 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
254 const char *const start
= name
;
256 /* Now fill the result path. While copying over the string we keep
257 track of the start of the last path element. When we come across
258 a DST we copy over the value or (if the value is not available)
259 leave the entire path element out. */
261 char *last_elem
= result
;
262 bool check_for_trusted
= false;
266 if (__glibc_unlikely (*name
== '$'))
268 const char *repl
= NULL
;
272 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
273 __libc_enable_secure
)) != 0)
276 check_for_trusted
= (__libc_enable_secure
277 && l
->l_type
== lt_executable
);
279 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
280 repl
= GLRO(dl_platform
);
281 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
284 if (repl
!= NULL
&& repl
!= (const char *) -1)
286 wp
= __stpcpy (wp
, repl
);
291 /* We cannot use this path element, the value of the
292 replacement is unknown. */
295 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
297 /* Also skip following colon if this is the first rpath
298 element, but keep an empty element at the end. */
299 if (wp
== result
&& is_path
&& *name
== ':' && name
[1] != '\0')
303 /* No DST we recognize. */
309 if (is_path
&& *name
== ':')
311 /* In SUID/SGID programs, after $ORIGIN expansion the
312 normalized path must be rooted in one of the trusted
314 if (__glibc_unlikely (check_for_trusted
)
315 && !is_trusted_path_normalize (last_elem
, wp
- last_elem
))
320 check_for_trusted
= false;
324 while (*name
!= '\0');
326 /* In SUID/SGID programs, after $ORIGIN expansion the normalized
327 path must be rooted in one of the trusted directories. */
328 if (__glibc_unlikely (check_for_trusted
)
329 && !is_trusted_path_normalize (last_elem
, wp
- last_elem
))
338 /* Return copy of argument with all recognized dynamic string tokens
339 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
340 might not be possible to determine the path from which the object
341 belonging to the map is loaded. In this case the path element
342 containing $ORIGIN is left out. */
344 expand_dynamic_string_token (struct link_map
*l
, const char *s
, int is_path
)
346 /* We make two runs over the string. First we determine how large the
347 resulting string is and then we copy it over. Since this is no
348 frequently executed operation we are looking here not for performance
349 but rather for code size. */
354 /* Determine the number of DST elements. */
355 cnt
= DL_DST_COUNT (s
, is_path
);
357 /* If we do not have to replace anything simply copy the string. */
358 if (__glibc_likely (cnt
== 0))
361 /* Determine the length of the substituted string. */
362 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
364 /* Allocate the necessary memory. */
365 result
= (char *) malloc (total
+ 1);
369 return _dl_dst_substitute (l
, s
, result
, is_path
);
373 /* Add `name' to the list of names for a particular shared object.
374 `name' is expected to have been allocated with malloc and will
375 be freed if the shared object already has this name.
376 Returns false if the object already had this name. */
378 add_name_to_object (struct link_map
*l
, const char *name
)
380 struct libname_list
*lnp
, *lastp
;
381 struct libname_list
*newname
;
385 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
386 if (strcmp (name
, lnp
->name
) == 0)
389 name_len
= strlen (name
) + 1;
390 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
393 /* No more memory. */
394 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
397 /* The object should have a libname set from _dl_new_object. */
398 assert (lastp
!= NULL
);
400 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
401 newname
->next
= NULL
;
402 newname
->dont_free
= 0;
403 lastp
->next
= newname
;
406 /* Standard search directories. */
407 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
409 static size_t max_dirnamelen
;
411 static struct r_search_path_elem
**
412 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
413 const char *what
, const char *where
, struct link_map
*l
)
419 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
421 struct r_search_path_elem
*dirp
;
423 to_free
= cp
= expand_dynamic_string_token (l
, cp
, 1);
425 size_t len
= strlen (cp
);
427 /* `strsep' can pass an empty string. This has to be
428 interpreted as `use the current directory'. */
431 static const char curwd
[] = "./";
435 /* Remove trailing slashes (except for "/"). */
436 while (len
> 1 && cp
[len
- 1] == '/')
439 /* Now add one if there is none so far. */
440 if (len
> 0 && cp
[len
- 1] != '/')
443 /* See if this directory is already known. */
444 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
445 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
450 /* It is available, see whether it's on our own list. */
452 for (cnt
= 0; cnt
< nelems
; ++cnt
)
453 if (result
[cnt
] == dirp
)
457 result
[nelems
++] = dirp
;
462 enum r_dir_status init_val
;
463 size_t where_len
= where
? strlen (where
) + 1 : 0;
465 /* It's a new directory. Create an entry and add it. */
466 dirp
= (struct r_search_path_elem
*)
467 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
468 + where_len
+ len
+ 1);
470 _dl_signal_error (ENOMEM
, NULL
, NULL
,
471 N_("cannot create cache for search path"));
473 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
474 + ncapstr
* sizeof (enum r_dir_status
));
475 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
476 dirp
->dirnamelen
= len
;
478 if (len
> max_dirnamelen
)
479 max_dirnamelen
= len
;
481 /* We have to make sure all the relative directories are
482 never ignored. The current directory might change and
483 all our saved information would be void. */
484 init_val
= cp
[0] != '/' ? existing
: unknown
;
485 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
486 dirp
->status
[cnt
] = init_val
;
489 if (__glibc_likely (where
!= NULL
))
490 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
491 + (ncapstr
* sizeof (enum r_dir_status
)),
496 dirp
->next
= GL(dl_all_dirs
);
497 GL(dl_all_dirs
) = dirp
;
499 /* Put it in the result array. */
500 result
[nelems
++] = dirp
;
505 /* Terminate the array. */
506 result
[nelems
] = NULL
;
513 decompose_rpath (struct r_search_path_struct
*sps
,
514 const char *rpath
, struct link_map
*l
, const char *what
)
516 /* Make a copy we can work with. */
517 const char *where
= l
->l_name
;
520 struct r_search_path_elem
**result
;
522 /* Initialize to please the compiler. */
523 const char *errstring
= NULL
;
525 /* First see whether we must forget the RUNPATH and RPATH from this
527 if (__glibc_unlikely (GLRO(dl_inhibit_rpath
) != NULL
)
528 && !__libc_enable_secure
)
530 const char *inhp
= GLRO(dl_inhibit_rpath
);
534 const char *wp
= where
;
536 while (*inhp
== *wp
&& *wp
!= '\0')
542 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
544 /* This object is on the list of objects for which the
545 RUNPATH and RPATH must not be used. */
546 sps
->dirs
= (void *) -1;
550 while (*inhp
!= '\0')
554 while (*inhp
!= '\0');
557 /* Make a writable copy. */
558 copy
= __strdup (rpath
);
561 errstring
= N_("cannot create RUNPATH/RPATH copy");
565 /* Ignore empty rpaths. */
569 sps
->dirs
= (struct r_search_path_elem
**) -1;
573 /* Count the number of necessary elements in the result array. */
575 for (cp
= copy
; *cp
!= '\0'; ++cp
)
579 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
580 number of necessary entries. */
581 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
586 errstring
= N_("cannot create cache for search path");
588 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
591 fillin_rpath (copy
, result
, ":", what
, where
, l
);
593 /* Free the copied RPATH string. `fillin_rpath' make own copies if
598 /* The caller will change this value if we haven't used a real malloc. */
603 /* Make sure cached path information is stored in *SP
604 and return true if there are any paths to search there. */
606 cache_rpath (struct link_map
*l
,
607 struct r_search_path_struct
*sp
,
611 if (sp
->dirs
== (void *) -1)
614 if (sp
->dirs
!= NULL
)
617 if (l
->l_info
[tag
] == NULL
)
619 /* There is no path. */
620 sp
->dirs
= (void *) -1;
624 /* Make sure the cache information is available. */
625 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
626 + l
->l_info
[tag
]->d_un
.d_val
),
632 _dl_init_paths (const char *llp
)
636 struct r_search_path_elem
*pelem
, **aelem
;
638 struct link_map
__attribute__ ((unused
)) *l
= NULL
;
639 /* Initialize to please the compiler. */
640 const char *errstring
= NULL
;
642 /* Fill in the information about the application's RPATH and the
643 directories addressed by the LD_LIBRARY_PATH environment variable. */
645 /* Get the capabilities. */
646 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
647 &ncapstr
, &max_capstrlen
);
649 /* First set up the rest of the default search directory entries. */
650 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
651 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
652 if (rtld_search_dirs
.dirs
== NULL
)
654 errstring
= N_("cannot create search path array");
656 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
659 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
660 + ncapstr
* sizeof (enum r_dir_status
))
661 / sizeof (struct r_search_path_elem
));
663 rtld_search_dirs
.dirs
[0] = malloc (nsystem_dirs_len
* round_size
664 * sizeof (*rtld_search_dirs
.dirs
[0]));
665 if (rtld_search_dirs
.dirs
[0] == NULL
)
667 errstring
= N_("cannot create cache for search path");
671 rtld_search_dirs
.malloced
= 0;
672 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
682 pelem
->what
= "system search path";
685 pelem
->dirname
= strp
;
686 pelem
->dirnamelen
= system_dirs_len
[idx
];
687 strp
+= system_dirs_len
[idx
] + 1;
689 /* System paths must be absolute. */
690 assert (pelem
->dirname
[0] == '/');
691 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
692 pelem
->status
[cnt
] = unknown
;
694 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
698 while (idx
< nsystem_dirs_len
);
700 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
704 /* This points to the map of the main object. */
705 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
708 assert (l
->l_type
!= lt_loaded
);
710 if (l
->l_info
[DT_RUNPATH
])
712 /* Allocate room for the search path and fill in information
714 decompose_rpath (&l
->l_runpath_dirs
,
715 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
716 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
718 /* During rtld init the memory is allocated by the stub malloc,
719 prevent any attempt to free it by the normal malloc. */
720 l
->l_runpath_dirs
.malloced
= 0;
722 /* The RPATH is ignored. */
723 l
->l_rpath_dirs
.dirs
= (void *) -1;
727 l
->l_runpath_dirs
.dirs
= (void *) -1;
729 if (l
->l_info
[DT_RPATH
])
731 /* Allocate room for the search path and fill in information
733 decompose_rpath (&l
->l_rpath_dirs
,
734 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
735 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
737 /* During rtld init the memory is allocated by the stub
738 malloc, prevent any attempt to free it by the normal
740 l
->l_rpath_dirs
.malloced
= 0;
743 l
->l_rpath_dirs
.dirs
= (void *) -1;
748 if (llp
!= NULL
&& *llp
!= '\0')
750 char *llp_tmp
= strdupa (llp
);
752 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
755 for (const char *cp
= llp_tmp
; *cp
!= '\0'; ++cp
)
756 if (*cp
== ':' || *cp
== ';')
759 env_path_list
.dirs
= (struct r_search_path_elem
**)
760 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
761 if (env_path_list
.dirs
== NULL
)
763 errstring
= N_("cannot create cache for search path");
767 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
768 "LD_LIBRARY_PATH", NULL
, l
);
770 if (env_path_list
.dirs
[0] == NULL
)
772 free (env_path_list
.dirs
);
773 env_path_list
.dirs
= (void *) -1;
776 env_path_list
.malloced
= 0;
779 env_path_list
.dirs
= (void *) -1;
784 __attribute__ ((noreturn
, noinline
))
785 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
786 const char *msg
, struct r_debug
*r
, Lmid_t nsid
)
788 /* The file might already be closed. */
791 if (l
!= NULL
&& l
->l_origin
!= (char *) -1l)
792 free ((char *) l
->l_origin
);
798 r
->r_state
= RT_CONSISTENT
;
800 LIBC_PROBE (map_failed
, 2, nsid
, r
);
803 _dl_signal_error (code
, name
, NULL
, msg
);
807 /* Map in the shared object NAME, actually located in REALNAME, and already
810 #ifndef EXTERNAL_MAP_FROM_FD
814 _dl_map_object_from_fd (const char *name
, const char *origname
, int fd
,
815 struct filebuf
*fbp
, char *realname
,
816 struct link_map
*loader
, int l_type
, int mode
,
817 void **stack_endp
, Lmid_t nsid
)
819 struct link_map
*l
= NULL
;
820 const ElfW(Ehdr
) *header
;
821 const ElfW(Phdr
) *phdr
;
822 const ElfW(Phdr
) *ph
;
825 /* Initialize to keep the compiler happy. */
826 const char *errstring
= NULL
;
828 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
829 bool make_consistent
= false;
831 /* Get file information. */
833 if (__glibc_unlikely (!_dl_get_file_id (fd
, &id
)))
835 errstring
= N_("cannot stat shared object");
839 lose (errval
, fd
, name
, realname
, l
, errstring
,
840 make_consistent
? r
: NULL
, nsid
);
843 /* Look again to see if the real name matched another already loaded. */
844 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
!= NULL
; l
= l
->l_next
)
845 if (!l
->l_removed
&& _dl_file_id_match_p (&l
->l_file_id
, &id
))
847 /* The object is already loaded.
848 Just bump its reference count and return it. */
851 /* If the name is not in the list of names for this object add
854 add_name_to_object (l
, name
);
860 /* When loading into a namespace other than the base one we must
861 avoid loading ld.so since there can only be one copy. Ever. */
862 if (__glibc_unlikely (nsid
!= LM_ID_BASE
)
863 && (_dl_file_id_match_p (&id
, &GL(dl_rtld_map
).l_file_id
)
864 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
866 /* This is indeed ld.so. Create a new link_map which refers to
867 the real one for almost everything. */
868 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
872 /* Refer to the real descriptor. */
873 l
->l_real
= &GL(dl_rtld_map
);
875 /* No need to bump the refcount of the real object, ld.so will
876 never be unloaded. */
879 /* Add the map for the mirrored object to the object list. */
880 _dl_add_to_namespace_list (l
, nsid
);
886 if (mode
& RTLD_NOLOAD
)
888 /* We are not supposed to load the object unless it is already
889 loaded. So return now. */
895 /* Print debugging message. */
896 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
897 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
899 /* This is the ELF header. We read it in `open_verify'. */
900 header
= (void *) fbp
->buf
;
904 if (_dl_zerofd
== -1)
906 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
907 if (_dl_zerofd
== -1)
911 _dl_signal_error (errno
, NULL
, NULL
,
912 N_("cannot open zero fill device"));
917 /* Signal that we are going to add new objects. */
918 if (r
->r_state
== RT_CONSISTENT
)
921 /* Auditing checkpoint: we are going to add new objects. */
922 if ((mode
& __RTLD_AUDIT
) == 0
923 && __glibc_unlikely (GLRO(dl_naudit
) > 0))
925 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
926 /* Do not call the functions for any auditing object. */
927 if (head
->l_auditing
== 0)
929 struct audit_ifaces
*afct
= GLRO(dl_audit
);
930 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
932 if (afct
->activity
!= NULL
)
933 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
941 /* Notify the debugger we have added some objects. We need to
942 call _dl_debug_initialize in a static program in case dynamic
943 linking has not been used before. */
946 LIBC_PROBE (map_start
, 2, nsid
, r
);
947 make_consistent
= true;
950 assert (r
->r_state
== RT_ADD
);
952 /* Enter the new object in the list of loaded objects. */
953 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
954 if (__glibc_unlikely (l
== NULL
))
959 errstring
= N_("cannot create shared object descriptor");
960 goto call_lose_errno
;
963 /* Extract the remaining details we need from the ELF header
964 and then read in the program header table. */
965 l
->l_entry
= header
->e_entry
;
966 type
= header
->e_type
;
967 l
->l_phnum
= header
->e_phnum
;
969 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
970 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
971 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
974 phdr
= alloca (maplength
);
975 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
976 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
978 errstring
= N_("cannot read file data");
979 goto call_lose_errno
;
983 /* On most platforms presume that PT_GNU_STACK is absent and the stack is
984 * executable. Other platforms default to a nonexecutable stack and don't
985 * need PT_GNU_STACK to do so. */
986 uint_fast16_t stack_flags
= DEFAULT_STACK_PERMS
;
989 /* Scan the program header table, collecting its load commands. */
990 struct loadcmd loadcmds
[l
->l_phnum
];
991 size_t nloadcmds
= 0;
992 bool has_holes
= false;
994 /* The struct is initialized to zero so this is not necessary:
998 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1001 /* These entries tell us where to find things once the file's
1002 segments are mapped in. We record the addresses it says
1003 verbatim, and later correct for the run-time load address. */
1007 /* Debuginfo only files from "objcopy --only-keep-debug"
1008 contain a PT_DYNAMIC segment with p_filesz == 0. Skip
1009 such a segment to avoid a crash later. */
1010 l
->l_ld
= (void *) ph
->p_vaddr
;
1011 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1016 l
->l_phdr
= (void *) ph
->p_vaddr
;
1020 /* A load command tells us to map in part of the file.
1021 We record the load commands and process them all later. */
1022 if (__glibc_unlikely ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0))
1024 errstring
= N_("ELF load command alignment not page-aligned");
1027 if (__glibc_unlikely (((ph
->p_vaddr
- ph
->p_offset
)
1028 & (ph
->p_align
- 1)) != 0))
1031 = N_("ELF load command address/offset not properly aligned");
1035 struct loadcmd
*c
= &loadcmds
[nloadcmds
++];
1036 c
->mapstart
= ALIGN_DOWN (ph
->p_vaddr
, GLRO(dl_pagesize
));
1037 c
->mapend
= ALIGN_UP (ph
->p_vaddr
+ ph
->p_filesz
, GLRO(dl_pagesize
));
1038 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1039 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1040 c
->mapoff
= ALIGN_DOWN (ph
->p_offset
, GLRO(dl_pagesize
));
1042 /* Determine whether there is a gap between the last segment
1044 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1047 /* Optimize a common case. */
1048 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1049 c
->prot
= (PF_TO_PROT
1050 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1053 if (ph
->p_flags
& PF_R
)
1054 c
->prot
|= PROT_READ
;
1055 if (ph
->p_flags
& PF_W
)
1056 c
->prot
|= PROT_WRITE
;
1057 if (ph
->p_flags
& PF_X
)
1058 c
->prot
|= PROT_EXEC
;
1063 if (ph
->p_memsz
== 0)
1064 /* Nothing to do for an empty segment. */
1067 l
->l_tls_blocksize
= ph
->p_memsz
;
1068 l
->l_tls_align
= ph
->p_align
;
1069 if (ph
->p_align
== 0)
1070 l
->l_tls_firstbyte_offset
= 0;
1072 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1073 l
->l_tls_initimage_size
= ph
->p_filesz
;
1074 /* Since we don't know the load address yet only store the
1075 offset. We will adjust it later. */
1076 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1078 /* If not loading the initial set of shared libraries,
1079 check whether we should permit loading a TLS segment. */
1080 if (__glibc_likely (l
->l_type
== lt_library
)
1081 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1082 not set up TLS data structures, so don't use them now. */
1083 || __glibc_likely (GL(dl_tls_dtv_slotinfo_list
) != NULL
))
1085 /* Assign the next available module ID. */
1086 l
->l_tls_modid
= _dl_next_tls_modid ();
1091 /* We are loading the executable itself when the dynamic
1092 linker was executed directly. The setup will happen
1093 later. Otherwise, the TLS data structures are already
1094 initialized, and we assigned a TLS modid above. */
1095 assert (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0);
1097 assert (false && "TLS not initialized in static application");
1102 stack_flags
= ph
->p_flags
;
1106 l
->l_relro_addr
= ph
->p_vaddr
;
1107 l
->l_relro_size
= ph
->p_memsz
;
1111 if (__glibc_unlikely (nloadcmds
== 0))
1113 /* This only happens for a bogus object that will be caught with
1114 another error below. But we don't want to go through the
1115 calculations below using NLOADCMDS - 1. */
1116 errstring
= N_("object file has no loadable segments");
1120 if (__glibc_unlikely (type
!= ET_DYN
)
1121 && __glibc_unlikely ((mode
& __RTLD_OPENEXEC
) == 0))
1123 /* This object is loaded at a fixed address. This must never
1124 happen for objects loaded with dlopen. */
1125 errstring
= N_("cannot dynamically load executable");
1129 /* Length of the sections to be loaded. */
1130 maplength
= loadcmds
[nloadcmds
- 1].allocend
- loadcmds
[0].mapstart
;
1132 /* Now process the load commands and map segments into memory.
1133 This is responsible for filling in:
1134 l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
1136 errstring
= _dl_map_segments (l
, fd
, header
, type
, loadcmds
, nloadcmds
,
1137 maplength
, has_holes
, loader
);
1138 if (__glibc_unlikely (errstring
!= NULL
))
1144 if (__glibc_unlikely (type
== ET_DYN
))
1146 errstring
= N_("object file has no dynamic section");
1151 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1153 elf_get_dynamic_info (l
, NULL
);
1155 /* Make sure we are not dlopen'ing an object that has the
1156 DF_1_NOOPEN flag set. */
1157 if (__glibc_unlikely (l
->l_flags_1
& DF_1_NOOPEN
)
1158 && (mode
& __RTLD_DLOPEN
))
1160 /* We are not supposed to load this object. Free all resources. */
1161 _dl_unmap_segments (l
);
1163 if (!l
->l_libname
->dont_free
)
1164 free (l
->l_libname
);
1166 if (l
->l_phdr_allocated
)
1167 free ((void *) l
->l_phdr
);
1169 errstring
= N_("shared object cannot be dlopen()ed");
1173 if (l
->l_phdr
== NULL
)
1175 /* The program header is not contained in any of the segments.
1176 We have to allocate memory ourself and copy it over from out
1178 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1179 * sizeof (ElfW(Phdr
)));
1182 errstring
= N_("cannot allocate memory for program header");
1183 goto call_lose_errno
;
1186 l
->l_phdr
= memcpy (newp
, phdr
,
1187 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1188 l
->l_phdr_allocated
= 1;
1191 /* Adjust the PT_PHDR value by the runtime load address. */
1192 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1194 if (__glibc_unlikely ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
))
1196 if (__glibc_unlikely (__check_caller (RETURN_ADDRESS (0), allow_ldso
) != 0))
1198 errstring
= N_("invalid caller");
1202 /* The stack is presently not executable, but this module
1203 requires that it be executable. We must change the
1204 protection of the variable which contains the flags used in
1205 the mprotect calls. */
1207 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1209 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1210 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1212 struct link_map
*const m
= &GL(dl_rtld_map
);
1213 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1215 & -GLRO(dl_pagesize
));
1216 if (__glibc_likely (p
+ s
<= relro_end
))
1218 /* The variable lies in the region protected by RELRO. */
1219 if (__mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
) < 0)
1221 errstring
= N_("cannot change memory protections");
1222 goto call_lose_errno
;
1224 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1225 __mprotect ((void *) p
, s
, PROT_READ
);
1228 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1232 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1234 #ifdef check_consistency
1235 check_consistency ();
1238 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1242 cannot enable executable stack as shared object requires");
1247 /* Adjust the address of the TLS initialization image. */
1248 if (l
->l_tls_initimage
!= NULL
)
1249 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1251 /* We are done mapping in the file. We no longer need the descriptor. */
1252 if (__glibc_unlikely (__close (fd
) != 0))
1254 errstring
= N_("cannot close file descriptor");
1255 goto call_lose_errno
;
1257 /* Signal that we closed the file. */
1260 /* If this is ET_EXEC, we should have loaded it as lt_executable. */
1261 assert (type
!= ET_EXEC
|| l
->l_type
== lt_executable
);
1263 l
->l_entry
+= l
->l_addr
;
1265 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
1266 _dl_debug_printf ("\
1267 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1268 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1269 (int) sizeof (void *) * 2,
1270 (unsigned long int) l
->l_ld
,
1271 (int) sizeof (void *) * 2,
1272 (unsigned long int) l
->l_addr
,
1273 (int) sizeof (void *) * 2, maplength
,
1274 (int) sizeof (void *) * 2,
1275 (unsigned long int) l
->l_entry
,
1276 (int) sizeof (void *) * 2,
1277 (unsigned long int) l
->l_phdr
,
1278 (int) sizeof (void *) * 2, l
->l_phnum
);
1280 /* Set up the symbol hash table. */
1283 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1284 have to do this for the main map. */
1285 if ((mode
& RTLD_DEEPBIND
) == 0
1286 && __glibc_unlikely (l
->l_info
[DT_SYMBOLIC
] != NULL
)
1287 && &l
->l_searchlist
!= l
->l_scope
[0])
1289 /* Create an appropriate searchlist. It contains only this map.
1290 This is the definition of DT_SYMBOLIC in SysVr4. */
1291 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1292 l
->l_symbolic_searchlist
.r_nlist
= 1;
1294 /* Now move the existing entries one back. */
1295 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1296 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1298 /* Now add the new entry. */
1299 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1302 /* Remember whether this object must be initialized first. */
1303 if (l
->l_flags_1
& DF_1_INITFIRST
)
1304 GL(dl_initfirst
) = l
;
1306 /* Finally the file information. */
1310 /* When auditing is used the recorded names might not include the
1311 name by which the DSO is actually known. Add that as well. */
1312 if (__glibc_unlikely (origname
!= NULL
))
1313 add_name_to_object (l
, origname
);
1315 /* Audit modules only exist when linking is dynamic so ORIGNAME
1316 cannot be non-NULL. */
1317 assert (origname
== NULL
);
1320 /* When we profile the SONAME might be needed for something else but
1321 loading. Add it right away. */
1322 if (__glibc_unlikely (GLRO(dl_profile
) != NULL
)
1323 && l
->l_info
[DT_SONAME
] != NULL
)
1324 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1325 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1327 #ifdef DL_AFTER_LOAD
1331 /* Now that the object is fully initialized add it to the object list. */
1332 _dl_add_to_namespace_list (l
, nsid
);
1335 /* Auditing checkpoint: we have a new object. */
1336 if (__glibc_unlikely (GLRO(dl_naudit
) > 0)
1337 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1339 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1340 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1342 if (afct
->objopen
!= NULL
)
1344 l
->l_audit
[cnt
].bindflags
1345 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1347 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1358 /* Print search path. */
1360 print_search_path (struct r_search_path_elem
**list
,
1361 const char *what
, const char *name
)
1363 char buf
[max_dirnamelen
+ max_capstrlen
];
1366 _dl_debug_printf (" search path=");
1368 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1370 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1373 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1374 if ((*list
)->status
[cnt
] != nonexisting
)
1376 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1377 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1382 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1390 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1391 DSO_FILENAME (name
));
1393 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1396 /* Open a file and verify it is an ELF file for this architecture. We
1397 ignore only ELF files for other architectures. Non-ELF files and
1398 ELF files with different header information cause fatal errors since
1399 this could mean there is something wrong in the installation and the
1400 user might want to know about this.
1402 If FD is not -1, then the file is already open and FD refers to it.
1403 In that case, FD is consumed for both successful and error returns. */
1405 open_verify (const char *name
, int fd
,
1406 struct filebuf
*fbp
, struct link_map
*loader
,
1407 int whatcode
, int mode
, bool *found_other_class
, bool free_name
)
1409 /* This is the expected ELF header. */
1410 #define ELF32_CLASS ELFCLASS32
1411 #define ELF64_CLASS ELFCLASS64
1412 #ifndef VALID_ELF_HEADER
1413 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1414 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1415 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1416 #elif defined MORE_ELF_HEADER_DATA
1417 MORE_ELF_HEADER_DATA
;
1419 static const unsigned char expected
[EI_NIDENT
] =
1421 [EI_MAG0
] = ELFMAG0
,
1422 [EI_MAG1
] = ELFMAG1
,
1423 [EI_MAG2
] = ELFMAG2
,
1424 [EI_MAG3
] = ELFMAG3
,
1425 [EI_CLASS
] = ELFW(CLASS
),
1426 [EI_DATA
] = byteorder
,
1427 [EI_VERSION
] = EV_CURRENT
,
1428 [EI_OSABI
] = ELFOSABI_SYSV
,
1433 ElfW(Word
) vendorlen
;
1437 } expected_note
= { 4, 16, 1, "GNU" };
1438 /* Initialize it to make the compiler happy. */
1439 const char *errstring
= NULL
;
1443 /* Give the auditing libraries a chance. */
1444 if (__glibc_unlikely (GLRO(dl_naudit
) > 0) && whatcode
!= 0
1445 && loader
->l_auditing
== 0)
1447 const char *original_name
= name
;
1448 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1449 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1451 if (afct
->objsearch
!= NULL
)
1453 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1456 /* Ignore the path. */
1463 if (fd
!= -1 && name
!= original_name
&& strcmp (name
, original_name
))
1465 /* An audit library changed what we're supposed to open,
1466 so FD no longer matches it. */
1474 /* Open the file. We always open files read-only. */
1475 fd
= __open (name
, O_RDONLY
| O_CLOEXEC
);
1480 ElfW(Phdr
) *phdr
, *ph
;
1481 ElfW(Word
) *abi_note
;
1482 unsigned int osversion
;
1485 /* We successfully opened the file. Now verify it is a file
1489 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1490 /* Read in the header. */
1493 ssize_t retlen
= __libc_read (fd
, fbp
->buf
+ fbp
->len
,
1494 sizeof (fbp
->buf
) - fbp
->len
);
1499 while (__glibc_unlikely (fbp
->len
< sizeof (ElfW(Ehdr
))));
1501 /* This is where the ELF header is loaded. */
1502 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1504 /* Now run the tests. */
1505 if (__glibc_unlikely (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
))))
1508 errstring
= (errval
== 0
1509 ? N_("file too short") : N_("cannot read file data"));
1513 char *realname
= (char *) name
;
1514 name
= strdupa (realname
);
1517 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
, 0);
1520 /* See whether the ELF header is what we expect. */
1521 if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1523 || !VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1524 ehdr
->e_ident
[EI_ABIVERSION
])
1525 || memcmp (&ehdr
->e_ident
[EI_PAD
],
1527 EI_NIDENT
- EI_PAD
) != 0))
1529 /* Something is wrong. */
1530 const Elf32_Word
*magp
= (const void *) ehdr
->e_ident
;
1532 #if BYTE_ORDER == LITTLE_ENDIAN
1533 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1534 (ELFMAG1
<< (EI_MAG1
* 8)) |
1535 (ELFMAG2
<< (EI_MAG2
* 8)) |
1536 (ELFMAG3
<< (EI_MAG3
* 8)))
1538 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1539 (ELFMAG1
<< (EI_MAG2
* 8)) |
1540 (ELFMAG2
<< (EI_MAG1
* 8)) |
1541 (ELFMAG3
<< (EI_MAG0
* 8)))
1544 errstring
= N_("invalid ELF header");
1545 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1547 /* This is not a fatal error. On architectures where
1548 32-bit and 64-bit binaries can be run this might
1550 *found_other_class
= true;
1553 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1555 if (BYTE_ORDER
== BIG_ENDIAN
)
1556 errstring
= N_("ELF file data encoding not big-endian");
1558 errstring
= N_("ELF file data encoding not little-endian");
1560 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1562 = N_("ELF file version ident does not match current one");
1563 /* XXX We should be able so set system specific versions which are
1565 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1566 errstring
= N_("ELF file OS ABI invalid");
1567 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1568 ehdr
->e_ident
[EI_ABIVERSION
]))
1569 errstring
= N_("ELF file ABI version invalid");
1570 else if (memcmp (&ehdr
->e_ident
[EI_PAD
], &expected
[EI_PAD
],
1571 EI_NIDENT
- EI_PAD
) != 0)
1572 errstring
= N_("nonzero padding in e_ident");
1574 /* Otherwise we don't know what went wrong. */
1575 errstring
= N_("internal error");
1580 if (__glibc_unlikely (ehdr
->e_version
!= EV_CURRENT
))
1582 errstring
= N_("ELF file version does not match current one");
1585 if (! __glibc_likely (elf_machine_matches_host (ehdr
)))
1587 else if (__glibc_unlikely (ehdr
->e_type
!= ET_DYN
1588 && ehdr
->e_type
!= ET_EXEC
))
1590 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1593 else if (__glibc_unlikely (ehdr
->e_type
== ET_EXEC
1594 && (mode
& __RTLD_OPENEXEC
) == 0))
1596 /* BZ #16634. It is an error to dlopen ET_EXEC (unless
1597 __RTLD_OPENEXEC is explicitly set). We return error here
1598 so that code in _dl_map_object_from_fd does not try to set
1599 l_tls_modid for this module. */
1601 errstring
= N_("cannot dynamically load executable");
1604 else if (__glibc_unlikely (ehdr
->e_phentsize
!= sizeof (ElfW(Phdr
))))
1606 errstring
= N_("ELF file's phentsize not the expected size");
1610 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1611 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1612 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1615 phdr
= alloca (maplength
);
1616 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1617 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1621 errstring
= N_("cannot read file data");
1626 if (__glibc_unlikely (elf_machine_reject_phdr_p
1627 (phdr
, ehdr
->e_phnum
, fbp
->buf
, fbp
->len
,
1631 /* Check .note.ABI-tag if present. */
1632 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1633 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1635 ElfW(Addr
) size
= ph
->p_filesz
;
1636 /* NB: Some PT_NOTE segment may have alignment value of 0
1637 or 1. gABI specifies that PT_NOTE segments should be
1638 aligned to 4 bytes in 32-bit objects and to 8 bytes in
1639 64-bit objects. As a Linux extension, we also support
1640 4 byte alignment in 64-bit objects. If p_align is less
1641 than 4, we treate alignment as 4 bytes since some note
1642 segments have 0 or 1 byte alignment. */
1643 ElfW(Addr
) align
= ph
->p_align
;
1646 else if (align
!= 4 && align
!= 8)
1649 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1650 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1653 abi_note
= alloca (size
);
1654 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1655 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1659 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1661 ElfW(Addr
) note_size
1662 = ELF_NOTE_NEXT_OFFSET (abi_note
[0], abi_note
[1],
1665 if (size
- 32 < note_size
)
1671 abi_note
= (void *) abi_note
+ note_size
;
1677 osversion
= (abi_note
[5] & 0xff) * 65536
1678 + (abi_note
[6] & 0xff) * 256
1679 + (abi_note
[7] & 0xff);
1680 if (abi_note
[4] != __ABI_TAG_OS
1681 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1685 __set_errno (ENOENT
);
1696 /* Try to open NAME in one of the directories in *DIRSP.
1697 Return the fd, or -1. If successful, fill in *REALNAME
1698 with the malloc'd full directory name. If it turns out
1699 that none of the directories in *DIRSP exists, *DIRSP is
1700 replaced with (void *) -1, and the old value is free()d
1701 if MAY_FREE_DIRS is true. */
1704 open_path (const char *name
, size_t namelen
, int mode
,
1705 struct r_search_path_struct
*sps
, char **realname
,
1706 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1707 bool *found_other_class
)
1709 struct r_search_path_elem
**dirs
= sps
->dirs
;
1712 const char *current_what
= NULL
;
1715 if (__glibc_unlikely (dirs
== NULL
))
1716 /* We're called before _dl_init_paths when loading the main executable
1717 given on the command line when rtld is run directly. */
1720 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1723 struct r_search_path_elem
*this_dir
= *dirs
;
1730 /* If we are debugging the search for libraries print the path
1731 now if it hasn't happened now. */
1732 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
)
1733 && current_what
!= this_dir
->what
)
1735 current_what
= this_dir
->what
;
1736 print_search_path (dirs
, current_what
, this_dir
->where
);
1739 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1740 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1742 /* Skip this directory if we know it does not exist. */
1743 if (this_dir
->status
[cnt
] == nonexisting
)
1747 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1752 /* Print name we try if this is wanted. */
1753 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
1754 _dl_debug_printf (" trying file=%s\n", buf
);
1756 fd
= open_verify (buf
, -1, fbp
, loader
, whatcode
, mode
,
1757 found_other_class
, false);
1758 if (this_dir
->status
[cnt
] == unknown
)
1761 this_dir
->status
[cnt
] = existing
;
1762 /* Do not update the directory information when loading
1763 auditing code. We must try to disturb the program as
1764 little as possible. */
1765 else if (loader
== NULL
1766 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1768 /* We failed to open machine dependent library. Let's
1769 test whether there is any directory at all. */
1772 buf
[buflen
- namelen
- 1] = '\0';
1774 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1775 || ! S_ISDIR (st
.st_mode
))
1776 /* The directory does not exist or it is no directory. */
1777 this_dir
->status
[cnt
] = nonexisting
;
1779 this_dir
->status
[cnt
] = existing
;
1783 /* Remember whether we found any existing directory. */
1784 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1786 if (fd
!= -1 && __glibc_unlikely (mode
& __RTLD_SECURE
)
1787 && __libc_enable_secure
)
1789 /* This is an extra security effort to make sure nobody can
1790 preload broken shared objects which are in the trusted
1791 directories and so exploit the bugs. */
1794 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1795 || (st
.st_mode
& S_ISUID
) == 0)
1797 /* The shared object cannot be tested for being SUID
1798 or this bit is not set. In this case we must not
1802 /* We simply ignore the file, signal this by setting
1803 the error value which would have been set by `open'. */
1811 *realname
= (char *) malloc (buflen
);
1812 if (*realname
!= NULL
)
1814 memcpy (*realname
, buf
, buflen
);
1819 /* No memory for the name, we certainly won't be able
1820 to load and link it. */
1825 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1826 /* The file exists and is readable, but something went wrong. */
1829 /* Remember whether we found anything. */
1832 while (*++dirs
!= NULL
);
1834 /* Remove the whole path if none of the directories exists. */
1835 if (__glibc_unlikely (! any
))
1837 /* Paths which were allocated using the minimal malloc() in ld.so
1838 must not be freed using the general free() in libc. */
1842 /* rtld_search_dirs and env_path_list are attribute_relro, therefore
1843 avoid writing into it. */
1844 if (sps
!= &rtld_search_dirs
&& sps
!= &env_path_list
)
1845 sps
->dirs
= (void *) -1;
1851 /* Map in the shared object file NAME. */
1854 _dl_map_object (struct link_map
*loader
, const char *name
,
1855 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1858 const char *origname
= NULL
;
1865 assert (nsid
< GL(dl_nns
));
1867 /* Look for this name among those already loaded. */
1868 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1870 /* If the requested name matches the soname of a loaded object,
1871 use that object. Elide this check for names that have not
1873 if (__glibc_unlikely ((l
->l_faked
| l
->l_removed
) != 0))
1875 if (!_dl_name_match_p (name
, l
))
1879 if (__glibc_likely (l
->l_soname_added
)
1880 || l
->l_info
[DT_SONAME
] == NULL
)
1883 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1884 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1885 if (strcmp (name
, soname
) != 0)
1888 /* We have a match on a new name -- cache it. */
1889 add_name_to_object (l
, soname
);
1890 l
->l_soname_added
= 1;
1893 /* We have a match. */
1897 /* Display information if we are debugging. */
1898 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
)
1900 _dl_debug_printf ((mode
& __RTLD_CALLMAP
) == 0
1901 ? "\nfile=%s [%lu]; needed by %s [%lu]\n"
1902 : "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
1903 name
, nsid
, DSO_FILENAME (loader
->l_name
), loader
->l_ns
);
1906 /* Give the auditing libraries a chance to change the name before we
1908 if (__glibc_unlikely (GLRO(dl_naudit
) > 0)
1909 && (loader
== NULL
|| loader
->l_auditing
== 0))
1911 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1912 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1914 if (afct
->objsearch
!= NULL
)
1916 const char *before
= name
;
1917 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1921 /* Do not try anything further. */
1925 if (before
!= name
&& strcmp (before
, name
) != 0)
1927 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
))
1928 _dl_debug_printf ("audit changed filename %s -> %s\n",
1931 if (origname
== NULL
)
1941 /* Will be true if we found a DSO which is of the other ELF class. */
1942 bool found_other_class
= false;
1944 if (strchr (name
, '/') == NULL
)
1946 /* Search for NAME in several places. */
1948 size_t namelen
= strlen (name
) + 1;
1950 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
1951 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
1955 /* When the object has the RUNPATH information we don't use any
1957 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
1959 /* This is the executable's map (if there is one). Make sure that
1960 we do not look at it twice. */
1961 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1962 bool did_main_map
= false;
1964 /* First try the DT_RPATH of the dependent object that caused NAME
1965 to be loaded. Then that object's dependent, and on up. */
1966 for (l
= loader
; l
; l
= l
->l_loader
)
1967 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
1969 fd
= open_path (name
, namelen
, mode
,
1971 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
1972 &found_other_class
);
1976 did_main_map
|= l
== main_map
;
1979 /* If dynamically linked, try the DT_RPATH of the executable
1980 itself. NB: we do this for lookups in any namespace. */
1981 if (fd
== -1 && !did_main_map
1982 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
1983 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
1985 fd
= open_path (name
, namelen
, mode
,
1986 &main_map
->l_rpath_dirs
,
1987 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
1988 &found_other_class
);
1991 /* Try the LD_LIBRARY_PATH environment variable. */
1992 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
1993 fd
= open_path (name
, namelen
, mode
, &env_path_list
,
1995 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
1996 LA_SER_LIBPATH
, &found_other_class
);
1998 /* Look at the RUNPATH information for this binary. */
1999 if (fd
== -1 && loader
!= NULL
2000 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2001 DT_RUNPATH
, "RUNPATH"))
2002 fd
= open_path (name
, namelen
, mode
,
2003 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2004 LA_SER_RUNPATH
, &found_other_class
);
2008 realname
= _dl_sysdep_open_object (name
, namelen
, &fd
);
2009 if (realname
!= NULL
)
2011 fd
= open_verify (realname
, fd
,
2012 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2013 LA_SER_CONFIG
, mode
, &found_other_class
,
2022 && (__glibc_likely ((mode
& __RTLD_SECURE
) == 0)
2023 || ! __libc_enable_secure
)
2024 && __glibc_likely (GLRO(dl_inhibit_cache
) == 0))
2026 /* Check the list of libraries in the file /etc/ld.so.cache,
2027 for compatibility with Linux's ldconfig program. */
2028 char *cached
= _dl_load_cache_lookup (name
);
2032 // XXX Correct to unconditionally default to namespace 0?
2034 ?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
2040 /* If the loader has the DF_1_NODEFLIB flag set we must not
2041 use a cache entry from any of these directories. */
2042 if (__glibc_unlikely (l
->l_flags_1
& DF_1_NODEFLIB
))
2044 const char *dirp
= system_dirs
;
2045 unsigned int cnt
= 0;
2049 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2051 /* The prefix matches. Don't use the entry. */
2057 dirp
+= system_dirs_len
[cnt
] + 1;
2060 while (cnt
< nsystem_dirs_len
);
2065 fd
= open_verify (cached
, -1,
2066 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2067 LA_SER_CONFIG
, mode
, &found_other_class
,
2069 if (__glibc_likely (fd
!= -1))
2078 /* Finally, try the default path. */
2080 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2081 || __glibc_likely (!(l
->l_flags_1
& DF_1_NODEFLIB
)))
2082 && rtld_search_dirs
.dirs
!= (void *) -1)
2083 fd
= open_path (name
, namelen
, mode
, &rtld_search_dirs
,
2084 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2086 /* Add another newline when we are tracing the library loading. */
2087 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
2088 _dl_debug_printf ("\n");
2092 /* The path may contain dynamic string tokens. */
2094 ? expand_dynamic_string_token (loader
, name
, 0)
2096 if (realname
== NULL
)
2100 fd
= open_verify (realname
, -1, &fb
,
2101 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0, mode
,
2102 &found_other_class
, true);
2103 if (__glibc_unlikely (fd
== -1))
2111 /* In case the LOADER information has only been provided to get to
2112 the appropriate RUNPATH/RPATH information we do not need it
2114 if (mode
& __RTLD_CALLMAP
)
2117 if (__glibc_unlikely (fd
== -1))
2120 && __glibc_likely ((GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
) == 0))
2122 /* We haven't found an appropriate library. But since we
2123 are only interested in the list of libraries this isn't
2124 so severe. Fake an entry with all the information we
2126 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2128 /* Allocate a new object map. */
2129 if ((name_copy
= __strdup (name
)) == NULL
2130 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2131 mode
, nsid
)) == NULL
)
2134 _dl_signal_error (ENOMEM
, name
, NULL
,
2135 N_("cannot create shared object descriptor"));
2137 /* Signal that this is a faked entry. */
2139 /* Since the descriptor is initialized with zero we do not
2141 l->l_reserved = 0; */
2142 l
->l_buckets
= &dummy_bucket
;
2146 /* Enter the object in the object list. */
2147 _dl_add_to_namespace_list (l
, nsid
);
2151 else if (found_other_class
)
2152 _dl_signal_error (0, name
, NULL
,
2153 ELFW(CLASS
) == ELFCLASS32
2154 ? N_("wrong ELF class: ELFCLASS64")
2155 : N_("wrong ELF class: ELFCLASS32"));
2157 _dl_signal_error (errno
, name
, NULL
,
2158 N_("cannot open shared object file"));
2161 void *stack_end
= __libc_stack_end
;
2162 return _dl_map_object_from_fd (name
, origname
, fd
, &fb
, realname
, loader
,
2163 type
, mode
, &stack_end
, nsid
);
2166 struct add_path_state
2175 add_path (struct add_path_state
*p
, const struct r_search_path_struct
*sps
,
2178 if (sps
->dirs
!= (void *) -1)
2180 struct r_search_path_elem
**dirs
= sps
->dirs
;
2183 const struct r_search_path_elem
*const r
= *dirs
++;
2187 p
->si
->dls_size
+= MAX (2, r
->dirnamelen
);
2191 Dl_serpath
*const sp
= &p
->si
->dls_serpath
[p
->idx
++];
2192 sp
->dls_name
= p
->allocptr
;
2193 if (r
->dirnamelen
< 2)
2194 *p
->allocptr
++ = r
->dirnamelen
? '/' : '.';
2196 p
->allocptr
= __mempcpy (p
->allocptr
,
2197 r
->dirname
, r
->dirnamelen
- 1);
2198 *p
->allocptr
++ = '\0';
2199 sp
->dls_flags
= flags
;
2202 while (*dirs
!= NULL
);
2207 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2215 struct add_path_state p
=
2217 .counting
= counting
,
2220 .allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
]
2223 # define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
2225 /* When the object has the RUNPATH information we don't use any RPATHs. */
2226 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2228 /* First try the DT_RPATH of the dependent object that caused NAME
2229 to be loaded. Then that object's dependent, and on up. */
2231 struct link_map
*l
= loader
;
2234 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2235 add_path (&p
, &l
->l_rpath_dirs
, XXX_RPATH
);
2240 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2241 if (loader
->l_ns
== LM_ID_BASE
)
2243 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2244 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2245 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2246 add_path (&p
, &l
->l_rpath_dirs
, XXX_RPATH
);
2250 /* Try the LD_LIBRARY_PATH environment variable. */
2251 add_path (&p
, &env_path_list
, XXX_ENV
);
2253 /* Look at the RUNPATH information for this binary. */
2254 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2255 add_path (&p
, &loader
->l_runpath_dirs
, XXX_RUNPATH
);
2258 Here is where ld.so.cache gets checked, but we don't have
2259 a way to indicate that in the results for Dl_serinfo. */
2261 /* Finally, try the default path. */
2262 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2263 add_path (&p
, &rtld_search_dirs
, XXX_default
);
2266 /* Count the struct size before the string area, which we didn't
2267 know before we completed dls_cnt. */
2268 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;