1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006, 2007 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <bits/wordsize.h>
31 #include <sys/param.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
36 #include <stackinfo.h>
42 /* On some systems, no flag bits are given to specify file mapping. */
47 /* The right way to map in the shared library files is MAP_COPY, which
48 makes a virtual copy of the data at the time of the mmap call; this
49 guarantees the mapped pages will be consistent even if the file is
50 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
51 get is MAP_PRIVATE, which copies each page when it is modified; this
52 means if the file is overwritten, we may at some point get some pages
53 from the new version after starting with pages from the old version.
55 To make up for the lack and avoid the overwriting problem,
56 what Linux does have is MAP_DENYWRITE. This prevents anyone
57 from modifying the file while we have it mapped. */
60 # define MAP_COPY (MAP_PRIVATE | MAP_DENYWRITE)
62 # define MAP_COPY MAP_PRIVATE
66 /* Some systems link their relocatable objects for another base address
67 than 0. We want to know the base address for these such that we can
68 subtract this address from the segment addresses during mapping.
69 This results in a more efficient address space usage. Defaults to
70 zero for almost all systems. */
72 # define MAP_BASE_ADDR(l) 0
77 #if BYTE_ORDER == BIG_ENDIAN
78 # define byteorder ELFDATA2MSB
79 #elif BYTE_ORDER == LITTLE_ENDIAN
80 # define byteorder ELFDATA2LSB
82 # error "Unknown BYTE_ORDER " BYTE_ORDER
83 # define byteorder ELFDATANONE
86 #define STRING(x) __STRING (x)
89 /* The fd is not examined when using MAP_ANON. */
93 # define ANONFD _dl_zerofd
96 /* Handle situations where we have a preferred location in memory for
97 the shared objects. */
98 #ifdef ELF_PREFERRED_ADDRESS_DATA
99 ELF_PREFERRED_ADDRESS_DATA
;
101 #ifndef ELF_PREFERRED_ADDRESS
102 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
104 #ifndef ELF_FIXED_ADDRESS
105 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
109 int __stack_prot attribute_hidden attribute_relro
110 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
112 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
119 /* Type for the buffer we put the ELF header and hopefully the program
120 header. This buffer does not really have to be too large. In most
121 cases the program header follows the ELF header directly. If this
122 is not the case all bets are off and we can make the header
123 arbitrarily large and still won't get it read. This means the only
124 question is how large are the ELF and program header combined. The
125 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
126 bytes long. Each program header entry is again 32 and 56 bytes
127 long respectively. I.e., even with a file which has 10 program
128 header entries we only have to read 372B/624B respectively. Add to
129 this a bit of margin for program notes and reading 512B and 832B
130 for 32-bit and 64-bit files respecitvely is enough. If this
131 heuristic should really fail for some file the code in
132 `_dl_map_object_from_fd' knows how to recover. */
137 # define FILEBUF_SIZE 512
139 # define FILEBUF_SIZE 832
141 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
144 /* This is the decomposed LD_LIBRARY_PATH search path. */
145 static struct r_search_path_struct env_path_list attribute_relro
;
147 /* List of the hardware capabilities we might end up using. */
148 static const struct r_strlenpair
*capstr attribute_relro
;
149 static size_t ncapstr attribute_relro
;
150 static size_t max_capstrlen attribute_relro
;
153 /* Get the generated information about the trusted directories. */
154 #include "trusted-dirs.h"
156 static const char system_dirs
[] = SYSTEM_DIRS
;
157 static const size_t system_dirs_len
[] =
161 #define nsystem_dirs_len \
162 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
165 /* Local version of `strdup' function. */
167 local_strdup (const char *s
)
169 size_t len
= strlen (s
) + 1;
170 void *new = malloc (len
);
175 return (char *) memcpy (new, s
, len
);
180 is_dst (const char *start
, const char *name
, const char *str
,
181 int is_path
, int secure
)
184 bool is_curly
= false;
193 while (name
[len
] == str
[len
] && name
[len
] != '\0')
198 if (name
[len
] != '}')
201 /* Point again at the beginning of the name. */
203 /* Skip over closing curly brace and adjust for the --name. */
206 else if (name
[len
] != '\0' && name
[len
] != '/'
207 && (!is_path
|| name
[len
] != ':'))
210 if (__builtin_expect (secure
, 0)
211 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
212 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
220 _dl_dst_count (const char *name
, int is_path
)
222 const char *const start
= name
;
229 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
230 is $ORIGIN alone) and it must always appear first in path. */
232 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
233 INTUSE(__libc_enable_secure
))) != 0
234 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
235 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
238 name
= strchr (name
+ len
, '$');
240 while (name
!= NULL
);
247 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
250 const char *const start
= name
;
251 char *last_elem
, *wp
;
253 /* Now fill the result path. While copying over the string we keep
254 track of the start of the last path element. When we come accross
255 a DST we copy over the value or (if the value is not available)
256 leave the entire path element out. */
257 last_elem
= wp
= result
;
261 if (__builtin_expect (*name
== '$', 0))
263 const char *repl
= NULL
;
267 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
268 INTUSE(__libc_enable_secure
))) != 0)
272 repl
= _dl_get_origin ();
277 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
278 repl
= GLRO(dl_platform
);
279 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
282 if (repl
!= NULL
&& repl
!= (const char *) -1)
284 wp
= __stpcpy (wp
, repl
);
289 /* We cannot use this path element, the value of the
290 replacement is unknown. */
293 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
297 /* No DST we recognize. */
303 if (is_path
&& *name
== ':')
307 while (*name
!= '\0');
315 /* Return copy of argument with all recognized dynamic string tokens
316 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
317 might not be possible to determine the path from which the object
318 belonging to the map is loaded. In this case the path element
319 containing $ORIGIN is left out. */
321 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
323 /* We make two runs over the string. First we determine how large the
324 resulting string is and then we copy it over. Since this is now
325 frequently executed operation we are looking here not for performance
326 but rather for code size. */
331 /* Determine the number of DST elements. */
332 cnt
= DL_DST_COUNT (s
, 1);
334 /* If we do not have to replace anything simply copy the string. */
335 if (__builtin_expect (cnt
, 0) == 0)
336 return local_strdup (s
);
338 /* Determine the length of the substituted string. */
339 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
341 /* Allocate the necessary memory. */
342 result
= (char *) malloc (total
+ 1);
346 return _dl_dst_substitute (l
, s
, result
, 1);
350 /* Add `name' to the list of names for a particular shared object.
351 `name' is expected to have been allocated with malloc and will
352 be freed if the shared object already has this name.
353 Returns false if the object already had this name. */
356 add_name_to_object (struct link_map
*l
, const char *name
)
358 struct libname_list
*lnp
, *lastp
;
359 struct libname_list
*newname
;
363 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
364 if (strcmp (name
, lnp
->name
) == 0)
367 name_len
= strlen (name
) + 1;
368 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
371 /* No more memory. */
372 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
375 /* The object should have a libname set from _dl_new_object. */
376 assert (lastp
!= NULL
);
378 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
379 newname
->next
= NULL
;
380 newname
->dont_free
= 0;
381 lastp
->next
= newname
;
384 /* Standard search directories. */
385 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
387 static size_t max_dirnamelen
;
389 static struct r_search_path_elem
**
390 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
391 int check_trusted
, const char *what
, const char *where
)
396 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
398 struct r_search_path_elem
*dirp
;
399 size_t len
= strlen (cp
);
401 /* `strsep' can pass an empty string. This has to be
402 interpreted as `use the current directory'. */
405 static const char curwd
[] = "./";
409 /* Remove trailing slashes (except for "/"). */
410 while (len
> 1 && cp
[len
- 1] == '/')
413 /* Now add one if there is none so far. */
414 if (len
> 0 && cp
[len
- 1] != '/')
417 /* Make sure we don't use untrusted directories if we run SUID. */
418 if (__builtin_expect (check_trusted
, 0))
420 const char *trun
= system_dirs
;
424 /* All trusted directories must be complete names. */
427 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
429 if (len
== system_dirs_len
[idx
]
430 && memcmp (trun
, cp
, len
) == 0)
437 trun
+= system_dirs_len
[idx
] + 1;
442 /* Simply drop this directory. */
446 /* See if this directory is already known. */
447 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
448 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
453 /* It is available, see whether it's on our own list. */
455 for (cnt
= 0; cnt
< nelems
; ++cnt
)
456 if (result
[cnt
] == dirp
)
460 result
[nelems
++] = dirp
;
465 enum r_dir_status init_val
;
466 size_t where_len
= where
? strlen (where
) + 1 : 0;
468 /* It's a new directory. Create an entry and add it. */
469 dirp
= (struct r_search_path_elem
*)
470 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
471 + where_len
+ len
+ 1);
473 _dl_signal_error (ENOMEM
, NULL
, NULL
,
474 N_("cannot create cache for search path"));
476 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
477 + ncapstr
* sizeof (enum r_dir_status
));
478 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
479 dirp
->dirnamelen
= len
;
481 if (len
> max_dirnamelen
)
482 max_dirnamelen
= len
;
484 /* We have to make sure all the relative directories are
485 never ignored. The current directory might change and
486 all our saved information would be void. */
487 init_val
= cp
[0] != '/' ? existing
: unknown
;
488 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
489 dirp
->status
[cnt
] = init_val
;
492 if (__builtin_expect (where
!= NULL
, 1))
493 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
494 + (ncapstr
* sizeof (enum r_dir_status
)),
499 dirp
->next
= GL(dl_all_dirs
);
500 GL(dl_all_dirs
) = dirp
;
502 /* Put it in the result array. */
503 result
[nelems
++] = dirp
;
507 /* Terminate the array. */
508 result
[nelems
] = NULL
;
516 decompose_rpath (struct r_search_path_struct
*sps
,
517 const char *rpath
, struct link_map
*l
, const char *what
)
519 /* Make a copy we can work with. */
520 const char *where
= l
->l_name
;
523 struct r_search_path_elem
**result
;
525 /* Initialize to please the compiler. */
526 const char *errstring
= NULL
;
528 /* First see whether we must forget the RUNPATH and RPATH from this
530 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
531 && !INTUSE(__libc_enable_secure
))
533 const char *inhp
= GLRO(dl_inhibit_rpath
);
537 const char *wp
= where
;
539 while (*inhp
== *wp
&& *wp
!= '\0')
545 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
547 /* This object is on the list of objects for which the
548 RUNPATH and RPATH must not be used. */
549 sps
->dirs
= (void *) -1;
553 while (*inhp
!= '\0')
557 while (*inhp
!= '\0');
560 /* Make a writable copy. At the same time expand possible dynamic
562 copy
= expand_dynamic_string_token (l
, rpath
);
565 errstring
= N_("cannot create RUNPATH/RPATH copy");
569 /* Count the number of necessary elements in the result array. */
571 for (cp
= copy
; *cp
!= '\0'; ++cp
)
575 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
576 number of necessary entries. */
577 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
582 errstring
= N_("cannot create cache for search path");
584 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
587 fillin_rpath (copy
, result
, ":", 0, what
, where
);
589 /* Free the copied RPATH string. `fillin_rpath' make own copies if
594 /* The caller will change this value if we haven't used a real malloc. */
599 /* Make sure cached path information is stored in *SP
600 and return true if there are any paths to search there. */
602 cache_rpath (struct link_map
*l
,
603 struct r_search_path_struct
*sp
,
607 if (sp
->dirs
== (void *) -1)
610 if (sp
->dirs
!= NULL
)
613 if (l
->l_info
[tag
] == NULL
)
615 /* There is no path. */
616 sp
->dirs
= (void *) -1;
620 /* Make sure the cache information is available. */
621 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
622 + l
->l_info
[tag
]->d_un
.d_val
),
629 _dl_init_paths (const char *llp
)
633 struct r_search_path_elem
*pelem
, **aelem
;
638 /* Initialize to please the compiler. */
639 const char *errstring
= NULL
;
641 /* Fill in the information about the application's RPATH and the
642 directories addressed by the LD_LIBRARY_PATH environment variable. */
644 /* Get the capabilities. */
645 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
646 &ncapstr
, &max_capstrlen
);
648 /* First set up the rest of the default search directory entries. */
649 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
650 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
651 if (rtld_search_dirs
.dirs
== NULL
)
653 errstring
= N_("cannot create search path array");
655 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
658 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
659 + ncapstr
* sizeof (enum r_dir_status
))
660 / sizeof (struct r_search_path_elem
));
662 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
663 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
664 * round_size
* sizeof (struct r_search_path_elem
));
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
),
719 /* The RPATH is ignored. */
720 l
->l_rpath_dirs
.dirs
= (void *) -1;
724 l
->l_runpath_dirs
.dirs
= (void *) -1;
726 if (l
->l_info
[DT_RPATH
])
728 /* Allocate room for the search path and fill in information
730 decompose_rpath (&l
->l_rpath_dirs
,
731 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
732 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
734 l
->l_rpath_dirs
.malloced
= 0;
737 l
->l_rpath_dirs
.dirs
= (void *) -1;
742 if (llp
!= NULL
&& *llp
!= '\0')
745 const char *cp
= llp
;
750 size_t cnt
= DL_DST_COUNT (llp
, 1);
751 if (__builtin_expect (cnt
== 0, 1))
752 llp_tmp
= strdupa (llp
);
755 /* Determine the length of the substituted string. */
756 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
758 /* Allocate the necessary memory. */
759 llp_tmp
= (char *) alloca (total
+ 1);
760 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
763 llp_tmp
= strdupa (llp
);
766 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
771 if (*cp
== ':' || *cp
== ';')
776 env_path_list
.dirs
= (struct r_search_path_elem
**)
777 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
778 if (env_path_list
.dirs
== NULL
)
780 errstring
= N_("cannot create cache for search path");
784 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
785 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
788 if (env_path_list
.dirs
[0] == NULL
)
790 free (env_path_list
.dirs
);
791 env_path_list
.dirs
= (void *) -1;
794 env_path_list
.malloced
= 0;
797 env_path_list
.dirs
= (void *) -1;
799 /* Remember the last search directory added at startup. */
800 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
805 __attribute__ ((noreturn
, noinline
))
806 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
807 const char *msg
, struct r_debug
*r
)
809 /* The file might already be closed. */
814 /* Remove the stillborn object from the list and free it. */
815 assert (l
->l_next
== NULL
);
816 if (l
->l_prev
== NULL
)
817 /* No other module loaded. This happens only in the static library,
818 or in rtld under --verify. */
819 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
821 l
->l_prev
->l_next
= NULL
;
822 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
829 r
->r_state
= RT_CONSISTENT
;
833 _dl_signal_error (code
, name
, NULL
, msg
);
837 /* Map in the shared object NAME, actually located in REALNAME, and already
840 #ifndef EXTERNAL_MAP_FROM_FD
844 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
845 char *realname
, struct link_map
*loader
, int l_type
,
846 int mode
, void **stack_endp
, Lmid_t nsid
)
848 struct link_map
*l
= NULL
;
849 const ElfW(Ehdr
) *header
;
850 const ElfW(Phdr
) *phdr
;
851 const ElfW(Phdr
) *ph
;
855 /* Initialize to keep the compiler happy. */
856 const char *errstring
= NULL
;
858 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
859 bool make_consistent
= false;
861 /* Get file information. */
862 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
864 errstring
= N_("cannot stat shared object");
868 lose (errval
, fd
, name
, realname
, l
, errstring
,
869 make_consistent
? r
: NULL
);
872 /* Look again to see if the real name matched another already loaded. */
873 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
874 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
876 /* The object is already loaded.
877 Just bump its reference count and return it. */
880 /* If the name is not in the list of names for this object add
883 add_name_to_object (l
, name
);
889 /* When loading into a namespace other than the base one we must
890 avoid loading ld.so since there can only be one copy. Ever. */
891 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
892 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
893 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
894 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
896 /* This is indeed ld.so. Create a new link_map which refers to
897 the real one for almost everything. */
898 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
902 /* Refer to the real descriptor. */
903 l
->l_real
= &GL(dl_rtld_map
);
905 /* No need to bump the refcount of the real object, ld.so will
906 never be unloaded. */
913 if (mode
& RTLD_NOLOAD
)
914 /* We are not supposed to load the object unless it is already
915 loaded. So return now. */
918 /* Print debugging message. */
919 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
920 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
922 /* This is the ELF header. We read it in `open_verify'. */
923 header
= (void *) fbp
->buf
;
927 if (_dl_zerofd
== -1)
929 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
930 if (_dl_zerofd
== -1)
933 _dl_signal_error (errno
, NULL
, NULL
,
934 N_("cannot open zero fill device"));
939 /* Signal that we are going to add new objects. */
940 if (r
->r_state
== RT_CONSISTENT
)
943 /* Auditing checkpoint: we are going to add new objects. */
944 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
946 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
947 /* Do not call the functions for any auditing object. */
948 if (head
->l_auditing
== 0)
950 struct audit_ifaces
*afct
= GLRO(dl_audit
);
951 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
953 if (afct
->activity
!= NULL
)
954 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
962 /* Notify the debugger we have added some objects. We need to
963 call _dl_debug_initialize in a static program in case dynamic
964 linking has not been used before. */
967 make_consistent
= true;
970 assert (r
->r_state
== RT_ADD
);
972 /* Enter the new object in the list of loaded objects. */
973 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
974 if (__builtin_expect (l
== NULL
, 0))
979 errstring
= N_("cannot create shared object descriptor");
980 goto call_lose_errno
;
983 /* Extract the remaining details we need from the ELF header
984 and then read in the program header table. */
985 l
->l_entry
= header
->e_entry
;
986 type
= header
->e_type
;
987 l
->l_phnum
= header
->e_phnum
;
989 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
990 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
991 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
994 phdr
= alloca (maplength
);
995 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
996 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
998 errstring
= N_("cannot read file data");
999 goto call_lose_errno
;
1003 /* Presumed absent PT_GNU_STACK. */
1004 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
1007 /* Scan the program header table, collecting its load commands. */
1010 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1013 } loadcmds
[l
->l_phnum
], *c
;
1014 size_t nloadcmds
= 0;
1015 bool has_holes
= false;
1017 /* The struct is initialized to zero so this is not necessary:
1021 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1024 /* These entries tell us where to find things once the file's
1025 segments are mapped in. We record the addresses it says
1026 verbatim, and later correct for the run-time load address. */
1028 l
->l_ld
= (void *) ph
->p_vaddr
;
1029 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1033 l
->l_phdr
= (void *) ph
->p_vaddr
;
1037 /* A load command tells us to map in part of the file.
1038 We record the load commands and process them all later. */
1039 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1042 errstring
= N_("ELF load command alignment not page-aligned");
1045 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1046 & (ph
->p_align
- 1)) != 0, 0))
1049 = N_("ELF load command address/offset not properly aligned");
1053 c
= &loadcmds
[nloadcmds
++];
1054 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1055 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1056 & ~(GLRO(dl_pagesize
) - 1));
1057 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1058 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1059 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1061 /* Determine whether there is a gap between the last segment
1063 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1066 /* Optimize a common case. */
1067 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1068 c
->prot
= (PF_TO_PROT
1069 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1072 if (ph
->p_flags
& PF_R
)
1073 c
->prot
|= PROT_READ
;
1074 if (ph
->p_flags
& PF_W
)
1075 c
->prot
|= PROT_WRITE
;
1076 if (ph
->p_flags
& PF_X
)
1077 c
->prot
|= PROT_EXEC
;
1082 if (ph
->p_memsz
== 0)
1083 /* Nothing to do for an empty segment. */
1086 l
->l_tls_blocksize
= ph
->p_memsz
;
1087 l
->l_tls_align
= ph
->p_align
;
1088 if (ph
->p_align
== 0)
1089 l
->l_tls_firstbyte_offset
= 0;
1091 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1092 l
->l_tls_initimage_size
= ph
->p_filesz
;
1093 /* Since we don't know the load address yet only store the
1094 offset. We will adjust it later. */
1095 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1097 /* If not loading the initial set of shared libraries,
1098 check whether we should permit loading a TLS segment. */
1099 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1100 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1101 not set up TLS data structures, so don't use them now. */
1102 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1104 /* Assign the next available module ID. */
1105 l
->l_tls_modid
= _dl_next_tls_modid ();
1110 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1111 /* We are loading the executable itself when the dynamic linker
1112 was executed directly. The setup will happen later. */
1115 /* In a static binary there is no way to tell if we dynamically
1116 loaded libpthread. */
1117 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1120 /* We have not yet loaded libpthread.
1121 We can do the TLS setup right now! */
1125 /* The first call allocates TLS bookkeeping data structures.
1126 Then we allocate the TCB for the initial thread. */
1127 if (__builtin_expect (_dl_tls_setup (), 0)
1128 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1133 cannot allocate TLS data structures for initial thread");
1137 /* Now we install the TCB in the thread register. */
1138 errstring
= TLS_INIT_TP (tcb
, 0);
1139 if (__builtin_expect (errstring
== NULL
, 1))
1141 /* Now we are all good. */
1142 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1146 /* The kernel is too old or somesuch. */
1148 _dl_deallocate_tls (tcb
, 1);
1152 /* Uh-oh, the binary expects TLS support but we cannot
1155 errstring
= N_("cannot handle TLS data");
1160 stack_flags
= ph
->p_flags
;
1164 l
->l_relro_addr
= ph
->p_vaddr
;
1165 l
->l_relro_size
= ph
->p_memsz
;
1169 if (__builtin_expect (nloadcmds
== 0, 0))
1171 /* This only happens for a bogus object that will be caught with
1172 another error below. But we don't want to go through the
1173 calculations below using NLOADCMDS - 1. */
1174 errstring
= N_("object file has no loadable segments");
1178 /* Now process the load commands and map segments into memory. */
1181 /* Length of the sections to be loaded. */
1182 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1184 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1186 /* This is a position-independent shared object. We can let the
1187 kernel map it anywhere it likes, but we must have space for all
1188 the segments in their specified positions relative to the first.
1189 So we map the first segment without MAP_FIXED, but with its
1190 extent increased to cover all the segments. Then we remove
1191 access from excess portion, and there is known sufficient space
1192 there to remap from the later segments.
1194 As a refinement, sometimes we have an address that we would
1195 prefer to map such objects at; but this is only a preference,
1196 the OS can do whatever it likes. */
1198 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1199 c
->mapstart
& GLRO(dl_use_load_bias
))
1200 - MAP_BASE_ADDR (l
));
1202 /* Remember which part of the address space this object uses. */
1203 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1207 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1210 errstring
= N_("failed to map segment from shared object");
1211 goto call_lose_errno
;
1214 l
->l_map_end
= l
->l_map_start
+ maplength
;
1215 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1218 /* Change protection on the excess portion to disallow all access;
1219 the portions we do not remap later will be inaccessible as if
1220 unallocated. Then jump into the normal segment-mapping loop to
1221 handle the portion of the segment past the end of the file
1223 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1224 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1227 l
->l_contiguous
= 1;
1232 /* This object is loaded at a fixed address. This must never
1233 happen for objects loaded with dlopen(). */
1234 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1236 errstring
= N_("cannot dynamically load executable");
1240 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1242 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1245 /* Remember which part of the address space this object uses. */
1246 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1247 l
->l_map_end
= l
->l_map_start
+ maplength
;
1248 l
->l_contiguous
= !has_holes
;
1250 while (c
< &loadcmds
[nloadcmds
])
1252 if (c
->mapend
> c
->mapstart
1253 /* Map the segment contents from the file. */
1254 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1255 c
->mapend
- c
->mapstart
, c
->prot
,
1256 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1262 if (c
->prot
& PROT_EXEC
)
1263 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1266 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1267 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1268 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1269 /* Found the program header in this segment. */
1270 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1272 if (c
->allocend
> c
->dataend
)
1274 /* Extra zero pages should appear at the end of this segment,
1275 after the data mapped from the file. */
1276 ElfW(Addr
) zero
, zeroend
, zeropage
;
1278 zero
= l
->l_addr
+ c
->dataend
;
1279 zeroend
= l
->l_addr
+ c
->allocend
;
1280 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1281 & ~(GLRO(dl_pagesize
) - 1));
1283 if (zeroend
< zeropage
)
1284 /* All the extra data is in the last page of the segment.
1285 We can just zero it. */
1288 if (zeropage
> zero
)
1290 /* Zero the final part of the last page of the segment. */
1291 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1294 if (__mprotect ((caddr_t
) (zero
1295 & ~(GLRO(dl_pagesize
) - 1)),
1296 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1298 errstring
= N_("cannot change memory protections");
1299 goto call_lose_errno
;
1302 memset ((void *) zero
, '\0', zeropage
- zero
);
1303 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1304 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1305 GLRO(dl_pagesize
), c
->prot
);
1308 if (zeroend
> zeropage
)
1310 /* Map the remaining zero pages in from the zero fill FD. */
1312 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1313 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1315 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1317 errstring
= N_("cannot map zero-fill pages");
1318 goto call_lose_errno
;
1329 if (__builtin_expect (type
== ET_DYN
, 0))
1331 errstring
= N_("object file has no dynamic section");
1336 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1338 elf_get_dynamic_info (l
, NULL
);
1340 /* Make sure we are not dlopen'ing an object that has the
1341 DF_1_NOOPEN flag set. */
1342 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1343 && (mode
& __RTLD_DLOPEN
))
1345 /* We are not supposed to load this object. Free all resources. */
1346 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1348 if (!l
->l_libname
->dont_free
)
1349 free (l
->l_libname
);
1351 if (l
->l_phdr_allocated
)
1352 free ((void *) l
->l_phdr
);
1354 errstring
= N_("shared object cannot be dlopen()ed");
1358 if (l
->l_phdr
== NULL
)
1360 /* The program header is not contained in any of the segments.
1361 We have to allocate memory ourself and copy it over from out
1363 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1364 * sizeof (ElfW(Phdr
)));
1367 errstring
= N_("cannot allocate memory for program header");
1368 goto call_lose_errno
;
1371 l
->l_phdr
= memcpy (newp
, phdr
,
1372 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1373 l
->l_phdr_allocated
= 1;
1376 /* Adjust the PT_PHDR value by the runtime load address. */
1377 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1379 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1381 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1384 errstring
= N_("invalid caller");
1388 /* The stack is presently not executable, but this module
1389 requires that it be executable. We must change the
1390 protection of the variable which contains the flags used in
1391 the mprotect calls. */
1393 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1395 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1396 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1398 struct link_map
*const m
= &GL(dl_rtld_map
);
1399 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1401 & -GLRO(dl_pagesize
));
1402 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1404 /* The variable lies in the region protected by RELRO. */
1405 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1406 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1407 __mprotect ((void *) p
, s
, PROT_READ
);
1410 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1414 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1416 #ifdef check_consistency
1417 check_consistency ();
1420 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1424 cannot enable executable stack as shared object requires");
1429 /* Adjust the address of the TLS initialization image. */
1430 if (l
->l_tls_initimage
!= NULL
)
1431 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1433 /* We are done mapping in the file. We no longer need the descriptor. */
1434 if (__builtin_expect (__close (fd
) != 0, 0))
1436 errstring
= N_("cannot close file descriptor");
1437 goto call_lose_errno
;
1439 /* Signal that we closed the file. */
1442 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1443 l
->l_type
= lt_executable
;
1445 l
->l_entry
+= l
->l_addr
;
1447 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1448 _dl_debug_printf ("\
1449 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1450 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1451 (int) sizeof (void *) * 2,
1452 (unsigned long int) l
->l_ld
,
1453 (int) sizeof (void *) * 2,
1454 (unsigned long int) l
->l_addr
,
1455 (int) sizeof (void *) * 2, maplength
,
1456 (int) sizeof (void *) * 2,
1457 (unsigned long int) l
->l_entry
,
1458 (int) sizeof (void *) * 2,
1459 (unsigned long int) l
->l_phdr
,
1460 (int) sizeof (void *) * 2, l
->l_phnum
);
1462 /* Set up the symbol hash table. */
1465 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1466 have to do this for the main map. */
1467 if ((mode
& RTLD_DEEPBIND
) == 0
1468 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1469 && &l
->l_searchlist
!= l
->l_scope
[0])
1471 /* Create an appropriate searchlist. It contains only this map.
1472 This is the definition of DT_SYMBOLIC in SysVr4. */
1473 l
->l_symbolic_searchlist
.r_list
=
1474 (struct link_map
**) malloc (sizeof (struct link_map
*));
1476 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1478 errstring
= N_("cannot create searchlist");
1479 goto call_lose_errno
;
1482 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1483 l
->l_symbolic_searchlist
.r_nlist
= 1;
1485 /* Now move the existing entries one back. */
1486 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1487 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1489 /* Now add the new entry. */
1490 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1493 /* Remember whether this object must be initialized first. */
1494 if (l
->l_flags_1
& DF_1_INITFIRST
)
1495 GL(dl_initfirst
) = l
;
1497 /* Finally the file information. */
1498 l
->l_dev
= st
.st_dev
;
1499 l
->l_ino
= st
.st_ino
;
1501 /* When we profile the SONAME might be needed for something else but
1502 loading. Add it right away. */
1503 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1504 && l
->l_info
[DT_SONAME
] != NULL
)
1505 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1506 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1509 /* Auditing checkpoint: we have a new object. */
1510 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1511 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1513 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1514 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1516 if (afct
->objopen
!= NULL
)
1518 l
->l_audit
[cnt
].bindflags
1519 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1521 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1532 /* Print search path. */
1534 print_search_path (struct r_search_path_elem
**list
,
1535 const char *what
, const char *name
)
1537 char buf
[max_dirnamelen
+ max_capstrlen
];
1540 _dl_debug_printf (" search path=");
1542 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1544 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1547 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1548 if ((*list
)->status
[cnt
] != nonexisting
)
1550 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1551 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1556 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1564 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1565 name
[0] ? name
: rtld_progname
);
1567 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1570 /* Open a file and verify it is an ELF file for this architecture. We
1571 ignore only ELF files for other architectures. Non-ELF files and
1572 ELF files with different header information cause fatal errors since
1573 this could mean there is something wrong in the installation and the
1574 user might want to know about this. */
1576 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1577 int whatcode
, bool *found_other_class
, bool free_name
)
1579 /* This is the expected ELF header. */
1580 #define ELF32_CLASS ELFCLASS32
1581 #define ELF64_CLASS ELFCLASS64
1582 #ifndef VALID_ELF_HEADER
1583 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1584 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1585 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1587 static const unsigned char expected
[EI_PAD
] =
1589 [EI_MAG0
] = ELFMAG0
,
1590 [EI_MAG1
] = ELFMAG1
,
1591 [EI_MAG2
] = ELFMAG2
,
1592 [EI_MAG3
] = ELFMAG3
,
1593 [EI_CLASS
] = ELFW(CLASS
),
1594 [EI_DATA
] = byteorder
,
1595 [EI_VERSION
] = EV_CURRENT
,
1596 [EI_OSABI
] = ELFOSABI_SYSV
,
1601 ElfW(Word
) vendorlen
;
1605 } expected_note
= { 4, 16, 1, "GNU" };
1606 /* Initialize it to make the compiler happy. */
1607 const char *errstring
= NULL
;
1611 /* Give the auditing libraries a chance. */
1612 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1613 && loader
->l_auditing
== 0)
1615 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1616 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1618 if (afct
->objsearch
!= NULL
)
1620 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1623 /* Ignore the path. */
1632 /* Open the file. We always open files read-only. */
1633 int fd
= __open (name
, O_RDONLY
);
1637 ElfW(Phdr
) *phdr
, *ph
;
1638 ElfW(Word
) *abi_note
;
1639 unsigned int osversion
;
1642 /* We successfully openened the file. Now verify it is a file
1645 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1647 /* This is where the ELF header is loaded. */
1648 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1649 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1651 /* Now run the tests. */
1652 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1655 errstring
= (errval
== 0
1656 ? N_("file too short") : N_("cannot read file data"));
1660 char *realname
= (char *) name
;
1661 name
= strdupa (realname
);
1664 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1667 /* See whether the ELF header is what we expect. */
1668 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1671 /* Something is wrong. */
1672 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1673 #if BYTE_ORDER == LITTLE_ENDIAN
1674 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1675 (ELFMAG1
<< (EI_MAG1
* 8)) |
1676 (ELFMAG2
<< (EI_MAG2
* 8)) |
1677 (ELFMAG3
<< (EI_MAG3
* 8)))
1679 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1680 (ELFMAG1
<< (EI_MAG2
* 8)) |
1681 (ELFMAG2
<< (EI_MAG1
* 8)) |
1682 (ELFMAG3
<< (EI_MAG0
* 8)))
1685 errstring
= N_("invalid ELF header");
1686 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1688 /* This is not a fatal error. On architectures where
1689 32-bit and 64-bit binaries can be run this might
1691 *found_other_class
= true;
1694 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1696 if (BYTE_ORDER
== BIG_ENDIAN
)
1697 errstring
= N_("ELF file data encoding not big-endian");
1699 errstring
= N_("ELF file data encoding not little-endian");
1701 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1703 = N_("ELF file version ident does not match current one");
1704 /* XXX We should be able so set system specific versions which are
1706 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1707 errstring
= N_("ELF file OS ABI invalid");
1708 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1709 errstring
= N_("ELF file ABI version invalid");
1711 /* Otherwise we don't know what went wrong. */
1712 errstring
= N_("internal error");
1717 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1719 errstring
= N_("ELF file version does not match current one");
1722 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1724 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1725 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1727 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1730 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1731 != sizeof (ElfW(Phdr
)))
1733 errstring
= N_("ELF file's phentsize not the expected size");
1737 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1738 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1739 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1742 phdr
= alloca (maplength
);
1743 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1744 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1748 errstring
= N_("cannot read file data");
1753 /* Check .note.ABI-tag if present. */
1754 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1755 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1757 ElfW(Addr
) size
= ph
->p_filesz
;
1759 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1760 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1763 abi_note
= alloca (size
);
1764 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1765 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1769 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1771 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1772 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1773 + ROUND (abi_note
[0])
1774 + ROUND (abi_note
[1]);
1776 if (size
- 32 < note_size
)
1782 abi_note
= (void *) abi_note
+ note_size
;
1788 osversion
= (abi_note
[5] & 0xff) * 65536
1789 + (abi_note
[6] & 0xff) * 256
1790 + (abi_note
[7] & 0xff);
1791 if (abi_note
[4] != __ABI_TAG_OS
1792 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1796 __set_errno (ENOENT
);
1807 /* Try to open NAME in one of the directories in *DIRSP.
1808 Return the fd, or -1. If successful, fill in *REALNAME
1809 with the malloc'd full directory name. If it turns out
1810 that none of the directories in *DIRSP exists, *DIRSP is
1811 replaced with (void *) -1, and the old value is free()d
1812 if MAY_FREE_DIRS is true. */
1815 open_path (const char *name
, size_t namelen
, int preloaded
,
1816 struct r_search_path_struct
*sps
, char **realname
,
1817 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1818 bool *found_other_class
)
1820 struct r_search_path_elem
**dirs
= sps
->dirs
;
1823 const char *current_what
= NULL
;
1826 if (__builtin_expect (dirs
== NULL
, 0))
1827 /* We're called before _dl_init_paths when loading the main executable
1828 given on the command line when rtld is run directly. */
1831 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1834 struct r_search_path_elem
*this_dir
= *dirs
;
1841 /* If we are debugging the search for libraries print the path
1842 now if it hasn't happened now. */
1843 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1844 && current_what
!= this_dir
->what
)
1846 current_what
= this_dir
->what
;
1847 print_search_path (dirs
, current_what
, this_dir
->where
);
1850 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1851 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1853 /* Skip this directory if we know it does not exist. */
1854 if (this_dir
->status
[cnt
] == nonexisting
)
1858 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1863 /* Print name we try if this is wanted. */
1864 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1865 _dl_debug_printf (" trying file=%s\n", buf
);
1867 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1869 if (this_dir
->status
[cnt
] == unknown
)
1872 this_dir
->status
[cnt
] = existing
;
1873 /* Do not update the directory information when loading
1874 auditing code. We must try to disturb the program as
1875 little as possible. */
1876 else if (loader
== NULL
1877 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1879 /* We failed to open machine dependent library. Let's
1880 test whether there is any directory at all. */
1883 buf
[buflen
- namelen
- 1] = '\0';
1885 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1886 || ! S_ISDIR (st
.st_mode
))
1887 /* The directory does not exist or it is no directory. */
1888 this_dir
->status
[cnt
] = nonexisting
;
1890 this_dir
->status
[cnt
] = existing
;
1894 /* Remember whether we found any existing directory. */
1895 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1897 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1898 && INTUSE(__libc_enable_secure
))
1900 /* This is an extra security effort to make sure nobody can
1901 preload broken shared objects which are in the trusted
1902 directories and so exploit the bugs. */
1905 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1906 || (st
.st_mode
& S_ISUID
) == 0)
1908 /* The shared object cannot be tested for being SUID
1909 or this bit is not set. In this case we must not
1913 /* We simply ignore the file, signal this by setting
1914 the error value which would have been set by `open'. */
1922 *realname
= (char *) malloc (buflen
);
1923 if (*realname
!= NULL
)
1925 memcpy (*realname
, buf
, buflen
);
1930 /* No memory for the name, we certainly won't be able
1931 to load and link it. */
1936 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1937 /* The file exists and is readable, but something went wrong. */
1940 /* Remember whether we found anything. */
1943 while (*++dirs
!= NULL
);
1945 /* Remove the whole path if none of the directories exists. */
1946 if (__builtin_expect (! any
, 0))
1948 /* Paths which were allocated using the minimal malloc() in ld.so
1949 must not be freed using the general free() in libc. */
1953 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1955 if (sps
!= &rtld_search_dirs
)
1956 sps
->dirs
= (void *) -1;
1962 /* Map in the shared object file NAME. */
1966 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1967 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1976 assert (nsid
< DL_NNS
);
1978 /* Look for this name among those already loaded. */
1979 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1981 /* If the requested name matches the soname of a loaded object,
1982 use that object. Elide this check for names that have not
1984 if (__builtin_expect (l
->l_faked
, 0) != 0
1985 || __builtin_expect (l
->l_removed
, 0) != 0)
1987 if (!_dl_name_match_p (name
, l
))
1991 if (__builtin_expect (l
->l_soname_added
, 1)
1992 || l
->l_info
[DT_SONAME
] == NULL
)
1995 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1996 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1997 if (strcmp (name
, soname
) != 0)
2000 /* We have a match on a new name -- cache it. */
2001 add_name_to_object (l
, soname
);
2002 l
->l_soname_added
= 1;
2005 /* We have a match. */
2009 /* Display information if we are debugging. */
2010 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2012 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2014 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2017 /* Give the auditing libraries a chance to change the name before we
2019 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2020 && (loader
== NULL
|| loader
->l_auditing
== 0))
2022 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2023 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2025 if (afct
->objsearch
!= NULL
)
2027 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2031 /* Do not try anything further. */
2042 /* Will be true if we found a DSO which is of the other ELF class. */
2043 bool found_other_class
= false;
2045 if (strchr (name
, '/') == NULL
)
2047 /* Search for NAME in several places. */
2049 size_t namelen
= strlen (name
) + 1;
2051 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2052 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2056 /* When the object has the RUNPATH information we don't use any
2058 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2060 /* This is the executable's map (if there is one). Make sure that
2061 we do not look at it twice. */
2062 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2063 bool did_main_map
= false;
2065 /* First try the DT_RPATH of the dependent object that caused NAME
2066 to be loaded. Then that object's dependent, and on up. */
2067 for (l
= loader
; l
; l
= l
->l_loader
)
2068 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2070 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2071 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2072 &found_other_class
);
2076 did_main_map
|= l
== main_map
;
2079 /* If dynamically linked, try the DT_RPATH of the executable
2080 itself. NB: we do this for lookups in any namespace. */
2081 if (fd
== -1 && !did_main_map
2082 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2083 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2085 fd
= open_path (name
, namelen
, preloaded
, &main_map
->l_rpath_dirs
,
2086 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2087 &found_other_class
);
2090 /* Try the LD_LIBRARY_PATH environment variable. */
2091 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2092 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2094 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2095 LA_SER_LIBPATH
, &found_other_class
);
2097 /* Look at the RUNPATH information for this binary. */
2098 if (fd
== -1 && loader
!= NULL
2099 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2100 DT_RUNPATH
, "RUNPATH"))
2101 fd
= open_path (name
, namelen
, preloaded
,
2102 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2103 LA_SER_RUNPATH
, &found_other_class
);
2106 && (__builtin_expect (! preloaded
, 1)
2107 || ! INTUSE(__libc_enable_secure
)))
2109 /* Check the list of libraries in the file /etc/ld.so.cache,
2110 for compatibility with Linux's ldconfig program. */
2111 const char *cached
= _dl_load_cache_lookup (name
);
2116 // XXX Correct to unconditionally default to namespace 0?
2117 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2122 /* If the loader has the DF_1_NODEFLIB flag set we must not
2123 use a cache entry from any of these directories. */
2126 /* 'l' is always != NULL for dynamically linked objects. */
2129 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2131 const char *dirp
= system_dirs
;
2132 unsigned int cnt
= 0;
2136 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2138 /* The prefix matches. Don't use the entry. */
2143 dirp
+= system_dirs_len
[cnt
] + 1;
2146 while (cnt
< nsystem_dirs_len
);
2151 fd
= open_verify (cached
,
2152 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2153 LA_SER_CONFIG
, &found_other_class
, false);
2154 if (__builtin_expect (fd
!= -1, 1))
2156 realname
= local_strdup (cached
);
2157 if (realname
== NULL
)
2167 /* Finally, try the default path. */
2169 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2170 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2171 && rtld_search_dirs
.dirs
!= (void *) -1)
2172 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2173 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2175 /* Add another newline when we are tracing the library loading. */
2176 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2177 _dl_debug_printf ("\n");
2181 /* The path may contain dynamic string tokens. */
2183 ? expand_dynamic_string_token (loader
, name
)
2184 : local_strdup (name
));
2185 if (realname
== NULL
)
2189 fd
= open_verify (realname
, &fb
,
2190 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2191 &found_other_class
, true);
2192 if (__builtin_expect (fd
, 0) == -1)
2200 /* In case the LOADER information has only been provided to get to
2201 the appropriate RUNPATH/RPATH information we do not need it
2203 if (mode
& __RTLD_CALLMAP
)
2206 if (__builtin_expect (fd
, 0) == -1)
2209 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2211 /* We haven't found an appropriate library. But since we
2212 are only interested in the list of libraries this isn't
2213 so severe. Fake an entry with all the information we
2215 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2217 /* Enter the new object in the list of loaded objects. */
2218 if ((name_copy
= local_strdup (name
)) == NULL
2219 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2220 mode
, nsid
)) == NULL
)
2223 _dl_signal_error (ENOMEM
, name
, NULL
,
2224 N_("cannot create shared object descriptor"));
2226 /* Signal that this is a faked entry. */
2228 /* Since the descriptor is initialized with zero we do not
2230 l->l_reserved = 0; */
2231 l
->l_buckets
= &dummy_bucket
;
2237 else if (found_other_class
)
2238 _dl_signal_error (0, name
, NULL
,
2239 ELFW(CLASS
) == ELFCLASS32
2240 ? N_("wrong ELF class: ELFCLASS64")
2241 : N_("wrong ELF class: ELFCLASS32"));
2243 _dl_signal_error (errno
, name
, NULL
,
2244 N_("cannot open shared object file"));
2247 void *stack_end
= __libc_stack_end
;
2248 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2255 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2263 unsigned int idx
= 0;
2264 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2265 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2266 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2268 if (sps
->dirs
!= (void *) -1)
2270 struct r_search_path_elem
**dirs
= sps
->dirs
;
2273 const struct r_search_path_elem
*const r
= *dirs
++;
2277 si
->dls_size
+= MAX (2, r
->dirnamelen
);
2281 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2282 sp
->dls_name
= allocptr
;
2283 if (r
->dirnamelen
< 2)
2284 *allocptr
++ = r
->dirnamelen
? '/' : '.';
2286 allocptr
= __mempcpy (allocptr
,
2287 r
->dirname
, r
->dirnamelen
- 1);
2289 sp
->dls_flags
= flags
;
2292 while (*dirs
!= NULL
);
2296 /* When the object has the RUNPATH information we don't use any RPATHs. */
2297 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2299 /* First try the DT_RPATH of the dependent object that caused NAME
2300 to be loaded. Then that object's dependent, and on up. */
2302 struct link_map
*l
= loader
;
2305 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2306 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2311 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2312 if (loader
->l_ns
== LM_ID_BASE
)
2314 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2315 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2316 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2317 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2321 /* Try the LD_LIBRARY_PATH environment variable. */
2322 add_path (&env_path_list
, XXX_ENV
);
2324 /* Look at the RUNPATH information for this binary. */
2325 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2326 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2329 Here is where ld.so.cache gets checked, but we don't have
2330 a way to indicate that in the results for Dl_serinfo. */
2332 /* Finally, try the default path. */
2333 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2334 add_path (&rtld_search_dirs
, XXX_default
);
2337 /* Count the struct size before the string area, which we didn't
2338 know before we completed dls_cnt. */
2339 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;