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)
581 errstring
= N_("cannot create cache for search path");
583 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
586 fillin_rpath (copy
, result
, ":", 0, what
, where
);
588 /* Free the copied RPATH string. `fillin_rpath' make own copies if
593 /* The caller will change this value if we haven't used a real malloc. */
598 /* Make sure cached path information is stored in *SP
599 and return true if there are any paths to search there. */
601 cache_rpath (struct link_map
*l
,
602 struct r_search_path_struct
*sp
,
606 if (sp
->dirs
== (void *) -1)
609 if (sp
->dirs
!= NULL
)
612 if (l
->l_info
[tag
] == NULL
)
614 /* There is no path. */
615 sp
->dirs
= (void *) -1;
619 /* Make sure the cache information is available. */
620 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
621 + l
->l_info
[tag
]->d_un
.d_val
),
628 _dl_init_paths (const char *llp
)
632 struct r_search_path_elem
*pelem
, **aelem
;
637 /* Initialize to please the compiler. */
638 const char *errstring
= NULL
;
640 /* Fill in the information about the application's RPATH and the
641 directories addressed by the LD_LIBRARY_PATH environment variable. */
643 /* Get the capabilities. */
644 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
645 &ncapstr
, &max_capstrlen
);
647 /* First set up the rest of the default search directory entries. */
648 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
649 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
650 if (rtld_search_dirs
.dirs
== NULL
)
652 errstring
= N_("cannot create search path array");
654 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
657 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
658 + ncapstr
* sizeof (enum r_dir_status
))
659 / sizeof (struct r_search_path_elem
));
661 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
662 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
663 * round_size
* sizeof (struct r_search_path_elem
));
664 if (rtld_search_dirs
.dirs
[0] == NULL
)
666 errstring
= N_("cannot create cache for search path");
670 rtld_search_dirs
.malloced
= 0;
671 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
681 pelem
->what
= "system search path";
684 pelem
->dirname
= strp
;
685 pelem
->dirnamelen
= system_dirs_len
[idx
];
686 strp
+= system_dirs_len
[idx
] + 1;
688 /* System paths must be absolute. */
689 assert (pelem
->dirname
[0] == '/');
690 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
691 pelem
->status
[cnt
] = unknown
;
693 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
697 while (idx
< nsystem_dirs_len
);
699 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
703 /* This points to the map of the main object. */
704 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
707 assert (l
->l_type
!= lt_loaded
);
709 if (l
->l_info
[DT_RUNPATH
])
711 /* Allocate room for the search path and fill in information
713 decompose_rpath (&l
->l_runpath_dirs
,
714 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
715 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
718 /* The RPATH is ignored. */
719 l
->l_rpath_dirs
.dirs
= (void *) -1;
723 l
->l_runpath_dirs
.dirs
= (void *) -1;
725 if (l
->l_info
[DT_RPATH
])
727 /* Allocate room for the search path and fill in information
729 decompose_rpath (&l
->l_rpath_dirs
,
730 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
731 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
733 l
->l_rpath_dirs
.malloced
= 0;
736 l
->l_rpath_dirs
.dirs
= (void *) -1;
741 if (llp
!= NULL
&& *llp
!= '\0')
744 const char *cp
= llp
;
749 size_t cnt
= DL_DST_COUNT (llp
, 1);
750 if (__builtin_expect (cnt
== 0, 1))
751 llp_tmp
= strdupa (llp
);
754 /* Determine the length of the substituted string. */
755 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
757 /* Allocate the necessary memory. */
758 llp_tmp
= (char *) alloca (total
+ 1);
759 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
762 llp_tmp
= strdupa (llp
);
765 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
770 if (*cp
== ':' || *cp
== ';')
775 env_path_list
.dirs
= (struct r_search_path_elem
**)
776 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
777 if (env_path_list
.dirs
== NULL
)
779 errstring
= N_("cannot create cache for search path");
783 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
784 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
787 if (env_path_list
.dirs
[0] == NULL
)
789 free (env_path_list
.dirs
);
790 env_path_list
.dirs
= (void *) -1;
793 env_path_list
.malloced
= 0;
796 env_path_list
.dirs
= (void *) -1;
798 /* Remember the last search directory added at startup. */
799 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
804 __attribute__ ((noreturn
, noinline
))
805 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
806 const char *msg
, struct r_debug
*r
)
808 /* The file might already be closed. */
813 /* Remove the stillborn object from the list and free it. */
814 assert (l
->l_next
== NULL
);
815 if (l
->l_prev
== NULL
)
816 /* No other module loaded. This happens only in the static library,
817 or in rtld under --verify. */
818 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
820 l
->l_prev
->l_next
= NULL
;
821 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
828 r
->r_state
= RT_CONSISTENT
;
832 _dl_signal_error (code
, name
, NULL
, msg
);
836 /* Map in the shared object NAME, actually located in REALNAME, and already
839 #ifndef EXTERNAL_MAP_FROM_FD
843 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
844 char *realname
, struct link_map
*loader
, int l_type
,
845 int mode
, void **stack_endp
, Lmid_t nsid
)
847 struct link_map
*l
= NULL
;
848 const ElfW(Ehdr
) *header
;
849 const ElfW(Phdr
) *phdr
;
850 const ElfW(Phdr
) *ph
;
854 /* Initialize to keep the compiler happy. */
855 const char *errstring
= NULL
;
857 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
858 bool make_consistent
= false;
860 /* Get file information. */
861 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
863 errstring
= N_("cannot stat shared object");
867 lose (errval
, fd
, name
, realname
, l
, errstring
,
868 make_consistent
? r
: NULL
);
871 /* Look again to see if the real name matched another already loaded. */
872 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
873 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
875 /* The object is already loaded.
876 Just bump its reference count and return it. */
879 /* If the name is not in the list of names for this object add
882 add_name_to_object (l
, name
);
888 /* When loading into a namespace other than the base one we must
889 avoid loading ld.so since there can only be one copy. Ever. */
890 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
891 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
892 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
893 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
895 /* This is indeed ld.so. Create a new link_map which refers to
896 the real one for almost everything. */
897 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
901 /* Refer to the real descriptor. */
902 l
->l_real
= &GL(dl_rtld_map
);
904 /* No need to bump the refcount of the real object, ld.so will
905 never be unloaded. */
912 if (mode
& RTLD_NOLOAD
)
913 /* We are not supposed to load the object unless it is already
914 loaded. So return now. */
917 /* Print debugging message. */
918 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
919 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
921 /* This is the ELF header. We read it in `open_verify'. */
922 header
= (void *) fbp
->buf
;
926 if (_dl_zerofd
== -1)
928 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
929 if (_dl_zerofd
== -1)
932 _dl_signal_error (errno
, NULL
, NULL
,
933 N_("cannot open zero fill device"));
938 /* Signal that we are going to add new objects. */
939 if (r
->r_state
== RT_CONSISTENT
)
942 /* Auditing checkpoint: we are going to add new objects. */
943 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
945 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
946 /* Do not call the functions for any auditing object. */
947 if (head
->l_auditing
== 0)
949 struct audit_ifaces
*afct
= GLRO(dl_audit
);
950 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
952 if (afct
->activity
!= NULL
)
953 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
961 /* Notify the debugger we have added some objects. We need to
962 call _dl_debug_initialize in a static program in case dynamic
963 linking has not been used before. */
966 make_consistent
= true;
969 assert (r
->r_state
== RT_ADD
);
971 /* Enter the new object in the list of loaded objects. */
972 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
973 if (__builtin_expect (l
== NULL
, 0))
978 errstring
= N_("cannot create shared object descriptor");
979 goto call_lose_errno
;
982 /* Extract the remaining details we need from the ELF header
983 and then read in the program header table. */
984 l
->l_entry
= header
->e_entry
;
985 type
= header
->e_type
;
986 l
->l_phnum
= header
->e_phnum
;
988 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
989 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
990 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
993 phdr
= alloca (maplength
);
994 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
995 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
997 errstring
= N_("cannot read file data");
998 goto call_lose_errno
;
1002 /* Presumed absent PT_GNU_STACK. */
1003 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
1006 /* Scan the program header table, collecting its load commands. */
1009 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1012 } loadcmds
[l
->l_phnum
], *c
;
1013 size_t nloadcmds
= 0;
1014 bool has_holes
= false;
1016 /* The struct is initialized to zero so this is not necessary:
1020 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1023 /* These entries tell us where to find things once the file's
1024 segments are mapped in. We record the addresses it says
1025 verbatim, and later correct for the run-time load address. */
1027 l
->l_ld
= (void *) ph
->p_vaddr
;
1028 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1032 l
->l_phdr
= (void *) ph
->p_vaddr
;
1036 /* A load command tells us to map in part of the file.
1037 We record the load commands and process them all later. */
1038 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1041 errstring
= N_("ELF load command alignment not page-aligned");
1044 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1045 & (ph
->p_align
- 1)) != 0, 0))
1048 = N_("ELF load command address/offset not properly aligned");
1052 c
= &loadcmds
[nloadcmds
++];
1053 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1054 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1055 & ~(GLRO(dl_pagesize
) - 1));
1056 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1057 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1058 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1060 /* Determine whether there is a gap between the last segment
1062 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1065 /* Optimize a common case. */
1066 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1067 c
->prot
= (PF_TO_PROT
1068 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1071 if (ph
->p_flags
& PF_R
)
1072 c
->prot
|= PROT_READ
;
1073 if (ph
->p_flags
& PF_W
)
1074 c
->prot
|= PROT_WRITE
;
1075 if (ph
->p_flags
& PF_X
)
1076 c
->prot
|= PROT_EXEC
;
1081 if (ph
->p_memsz
== 0)
1082 /* Nothing to do for an empty segment. */
1085 l
->l_tls_blocksize
= ph
->p_memsz
;
1086 l
->l_tls_align
= ph
->p_align
;
1087 if (ph
->p_align
== 0)
1088 l
->l_tls_firstbyte_offset
= 0;
1090 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1091 l
->l_tls_initimage_size
= ph
->p_filesz
;
1092 /* Since we don't know the load address yet only store the
1093 offset. We will adjust it later. */
1094 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1096 /* If not loading the initial set of shared libraries,
1097 check whether we should permit loading a TLS segment. */
1098 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1099 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1100 not set up TLS data structures, so don't use them now. */
1101 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1103 /* Assign the next available module ID. */
1104 l
->l_tls_modid
= _dl_next_tls_modid ();
1109 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1110 /* We are loading the executable itself when the dynamic linker
1111 was executed directly. The setup will happen later. */
1114 /* In a static binary there is no way to tell if we dynamically
1115 loaded libpthread. */
1116 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1119 /* We have not yet loaded libpthread.
1120 We can do the TLS setup right now! */
1124 /* The first call allocates TLS bookkeeping data structures.
1125 Then we allocate the TCB for the initial thread. */
1126 if (__builtin_expect (_dl_tls_setup (), 0)
1127 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1132 cannot allocate TLS data structures for initial thread");
1136 /* Now we install the TCB in the thread register. */
1137 errstring
= TLS_INIT_TP (tcb
, 0);
1138 if (__builtin_expect (errstring
== NULL
, 1))
1140 /* Now we are all good. */
1141 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1145 /* The kernel is too old or somesuch. */
1147 _dl_deallocate_tls (tcb
, 1);
1151 /* Uh-oh, the binary expects TLS support but we cannot
1154 errstring
= N_("cannot handle TLS data");
1159 stack_flags
= ph
->p_flags
;
1163 l
->l_relro_addr
= ph
->p_vaddr
;
1164 l
->l_relro_size
= ph
->p_memsz
;
1168 if (__builtin_expect (nloadcmds
== 0, 0))
1170 /* This only happens for a bogus object that will be caught with
1171 another error below. But we don't want to go through the
1172 calculations below using NLOADCMDS - 1. */
1173 errstring
= N_("object file has no loadable segments");
1177 /* Now process the load commands and map segments into memory. */
1180 /* Length of the sections to be loaded. */
1181 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1183 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1185 /* This is a position-independent shared object. We can let the
1186 kernel map it anywhere it likes, but we must have space for all
1187 the segments in their specified positions relative to the first.
1188 So we map the first segment without MAP_FIXED, but with its
1189 extent increased to cover all the segments. Then we remove
1190 access from excess portion, and there is known sufficient space
1191 there to remap from the later segments.
1193 As a refinement, sometimes we have an address that we would
1194 prefer to map such objects at; but this is only a preference,
1195 the OS can do whatever it likes. */
1197 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1198 c
->mapstart
& GLRO(dl_use_load_bias
))
1199 - MAP_BASE_ADDR (l
));
1201 /* Remember which part of the address space this object uses. */
1202 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1206 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1209 errstring
= N_("failed to map segment from shared object");
1210 goto call_lose_errno
;
1213 l
->l_map_end
= l
->l_map_start
+ maplength
;
1214 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1217 /* Change protection on the excess portion to disallow all access;
1218 the portions we do not remap later will be inaccessible as if
1219 unallocated. Then jump into the normal segment-mapping loop to
1220 handle the portion of the segment past the end of the file
1222 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1223 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1226 l
->l_contiguous
= 1;
1231 /* This object is loaded at a fixed address. This must never
1232 happen for objects loaded with dlopen(). */
1233 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1235 errstring
= N_("cannot dynamically load executable");
1239 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1241 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1244 /* Remember which part of the address space this object uses. */
1245 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1246 l
->l_map_end
= l
->l_map_start
+ maplength
;
1247 l
->l_contiguous
= !has_holes
;
1249 while (c
< &loadcmds
[nloadcmds
])
1251 if (c
->mapend
> c
->mapstart
1252 /* Map the segment contents from the file. */
1253 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1254 c
->mapend
- c
->mapstart
, c
->prot
,
1255 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1261 if (c
->prot
& PROT_EXEC
)
1262 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1265 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1266 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1267 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1268 /* Found the program header in this segment. */
1269 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1271 if (c
->allocend
> c
->dataend
)
1273 /* Extra zero pages should appear at the end of this segment,
1274 after the data mapped from the file. */
1275 ElfW(Addr
) zero
, zeroend
, zeropage
;
1277 zero
= l
->l_addr
+ c
->dataend
;
1278 zeroend
= l
->l_addr
+ c
->allocend
;
1279 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1280 & ~(GLRO(dl_pagesize
) - 1));
1282 if (zeroend
< zeropage
)
1283 /* All the extra data is in the last page of the segment.
1284 We can just zero it. */
1287 if (zeropage
> zero
)
1289 /* Zero the final part of the last page of the segment. */
1290 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1293 if (__mprotect ((caddr_t
) (zero
1294 & ~(GLRO(dl_pagesize
) - 1)),
1295 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1297 errstring
= N_("cannot change memory protections");
1298 goto call_lose_errno
;
1301 memset ((void *) zero
, '\0', zeropage
- zero
);
1302 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1303 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1304 GLRO(dl_pagesize
), c
->prot
);
1307 if (zeroend
> zeropage
)
1309 /* Map the remaining zero pages in from the zero fill FD. */
1311 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1312 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1314 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1316 errstring
= N_("cannot map zero-fill pages");
1317 goto call_lose_errno
;
1328 if (__builtin_expect (type
== ET_DYN
, 0))
1330 errstring
= N_("object file has no dynamic section");
1335 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1337 elf_get_dynamic_info (l
, NULL
);
1339 /* Make sure we are not dlopen'ing an object that has the
1340 DF_1_NOOPEN flag set. */
1341 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1342 && (mode
& __RTLD_DLOPEN
))
1344 /* We are not supposed to load this object. Free all resources. */
1345 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1347 if (!l
->l_libname
->dont_free
)
1348 free (l
->l_libname
);
1350 if (l
->l_phdr_allocated
)
1351 free ((void *) l
->l_phdr
);
1353 errstring
= N_("shared object cannot be dlopen()ed");
1357 if (l
->l_phdr
== NULL
)
1359 /* The program header is not contained in any of the segments.
1360 We have to allocate memory ourself and copy it over from out
1362 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1363 * sizeof (ElfW(Phdr
)));
1366 errstring
= N_("cannot allocate memory for program header");
1367 goto call_lose_errno
;
1370 l
->l_phdr
= memcpy (newp
, phdr
,
1371 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1372 l
->l_phdr_allocated
= 1;
1375 /* Adjust the PT_PHDR value by the runtime load address. */
1376 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1378 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1380 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1383 errstring
= N_("invalid caller");
1387 /* The stack is presently not executable, but this module
1388 requires that it be executable. We must change the
1389 protection of the variable which contains the flags used in
1390 the mprotect calls. */
1392 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1394 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1395 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1397 struct link_map
*const m
= &GL(dl_rtld_map
);
1398 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1400 & -GLRO(dl_pagesize
));
1401 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1403 /* The variable lies in the region protected by RELRO. */
1404 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1405 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1406 __mprotect ((void *) p
, s
, PROT_READ
);
1409 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1413 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1415 #ifdef check_consistency
1416 check_consistency ();
1419 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1423 cannot enable executable stack as shared object requires");
1428 /* Adjust the address of the TLS initialization image. */
1429 if (l
->l_tls_initimage
!= NULL
)
1430 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1432 /* We are done mapping in the file. We no longer need the descriptor. */
1433 if (__builtin_expect (__close (fd
) != 0, 0))
1435 errstring
= N_("cannot close file descriptor");
1436 goto call_lose_errno
;
1438 /* Signal that we closed the file. */
1441 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1442 l
->l_type
= lt_executable
;
1444 l
->l_entry
+= l
->l_addr
;
1446 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1447 _dl_debug_printf ("\
1448 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1449 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1450 (int) sizeof (void *) * 2,
1451 (unsigned long int) l
->l_ld
,
1452 (int) sizeof (void *) * 2,
1453 (unsigned long int) l
->l_addr
,
1454 (int) sizeof (void *) * 2, maplength
,
1455 (int) sizeof (void *) * 2,
1456 (unsigned long int) l
->l_entry
,
1457 (int) sizeof (void *) * 2,
1458 (unsigned long int) l
->l_phdr
,
1459 (int) sizeof (void *) * 2, l
->l_phnum
);
1461 /* Set up the symbol hash table. */
1464 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1465 have to do this for the main map. */
1466 if ((mode
& RTLD_DEEPBIND
) == 0
1467 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1468 && &l
->l_searchlist
!= l
->l_scope
[0])
1470 /* Create an appropriate searchlist. It contains only this map.
1471 This is the definition of DT_SYMBOLIC in SysVr4. */
1472 l
->l_symbolic_searchlist
.r_list
=
1473 (struct link_map
**) malloc (sizeof (struct link_map
*));
1475 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1477 errstring
= N_("cannot create searchlist");
1478 goto call_lose_errno
;
1481 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1482 l
->l_symbolic_searchlist
.r_nlist
= 1;
1484 /* Now move the existing entries one back. */
1485 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1486 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1488 /* Now add the new entry. */
1489 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1492 /* Remember whether this object must be initialized first. */
1493 if (l
->l_flags_1
& DF_1_INITFIRST
)
1494 GL(dl_initfirst
) = l
;
1496 /* Finally the file information. */
1497 l
->l_dev
= st
.st_dev
;
1498 l
->l_ino
= st
.st_ino
;
1500 /* When we profile the SONAME might be needed for something else but
1501 loading. Add it right away. */
1502 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1503 && l
->l_info
[DT_SONAME
] != NULL
)
1504 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1505 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1508 /* Auditing checkpoint: we have a new object. */
1509 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1510 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1512 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1513 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1515 if (afct
->objopen
!= NULL
)
1517 l
->l_audit
[cnt
].bindflags
1518 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1520 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1531 /* Print search path. */
1533 print_search_path (struct r_search_path_elem
**list
,
1534 const char *what
, const char *name
)
1536 char buf
[max_dirnamelen
+ max_capstrlen
];
1539 _dl_debug_printf (" search path=");
1541 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1543 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1546 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1547 if ((*list
)->status
[cnt
] != nonexisting
)
1549 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1550 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1555 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1563 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1564 name
[0] ? name
: rtld_progname
);
1566 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1569 /* Open a file and verify it is an ELF file for this architecture. We
1570 ignore only ELF files for other architectures. Non-ELF files and
1571 ELF files with different header information cause fatal errors since
1572 this could mean there is something wrong in the installation and the
1573 user might want to know about this. */
1575 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1576 int whatcode
, bool *found_other_class
, bool free_name
)
1578 /* This is the expected ELF header. */
1579 #define ELF32_CLASS ELFCLASS32
1580 #define ELF64_CLASS ELFCLASS64
1581 #ifndef VALID_ELF_HEADER
1582 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1583 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1584 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1586 static const unsigned char expected
[EI_PAD
] =
1588 [EI_MAG0
] = ELFMAG0
,
1589 [EI_MAG1
] = ELFMAG1
,
1590 [EI_MAG2
] = ELFMAG2
,
1591 [EI_MAG3
] = ELFMAG3
,
1592 [EI_CLASS
] = ELFW(CLASS
),
1593 [EI_DATA
] = byteorder
,
1594 [EI_VERSION
] = EV_CURRENT
,
1595 [EI_OSABI
] = ELFOSABI_SYSV
,
1600 ElfW(Word
) vendorlen
;
1604 } expected_note
= { 4, 16, 1, "GNU" };
1605 /* Initialize it to make the compiler happy. */
1606 const char *errstring
= NULL
;
1610 /* Give the auditing libraries a chance. */
1611 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1612 && loader
->l_auditing
== 0)
1614 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1615 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1617 if (afct
->objsearch
!= NULL
)
1619 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1622 /* Ignore the path. */
1631 /* Open the file. We always open files read-only. */
1632 int fd
= __open (name
, O_RDONLY
);
1636 ElfW(Phdr
) *phdr
, *ph
;
1637 ElfW(Word
) *abi_note
;
1638 unsigned int osversion
;
1641 /* We successfully openened the file. Now verify it is a file
1644 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1646 /* This is where the ELF header is loaded. */
1647 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1648 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1650 /* Now run the tests. */
1651 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1654 errstring
= (errval
== 0
1655 ? N_("file too short") : N_("cannot read file data"));
1659 char *realname
= (char *) name
;
1660 name
= strdupa (realname
);
1663 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1666 /* See whether the ELF header is what we expect. */
1667 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1670 /* Something is wrong. */
1671 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1672 #if BYTE_ORDER == LITTLE_ENDIAN
1673 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1674 (ELFMAG1
<< (EI_MAG1
* 8)) |
1675 (ELFMAG2
<< (EI_MAG2
* 8)) |
1676 (ELFMAG3
<< (EI_MAG3
* 8)))
1678 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1679 (ELFMAG1
<< (EI_MAG2
* 8)) |
1680 (ELFMAG2
<< (EI_MAG1
* 8)) |
1681 (ELFMAG3
<< (EI_MAG0
* 8)))
1684 errstring
= N_("invalid ELF header");
1685 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1687 /* This is not a fatal error. On architectures where
1688 32-bit and 64-bit binaries can be run this might
1690 *found_other_class
= true;
1693 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1695 if (BYTE_ORDER
== BIG_ENDIAN
)
1696 errstring
= N_("ELF file data encoding not big-endian");
1698 errstring
= N_("ELF file data encoding not little-endian");
1700 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1702 = N_("ELF file version ident does not match current one");
1703 /* XXX We should be able so set system specific versions which are
1705 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1706 errstring
= N_("ELF file OS ABI invalid");
1707 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1708 errstring
= N_("ELF file ABI version invalid");
1710 /* Otherwise we don't know what went wrong. */
1711 errstring
= N_("internal error");
1716 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1718 errstring
= N_("ELF file version does not match current one");
1721 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1723 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1724 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1726 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1729 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1730 != sizeof (ElfW(Phdr
)))
1732 errstring
= N_("ELF file's phentsize not the expected size");
1736 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1737 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1738 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1741 phdr
= alloca (maplength
);
1742 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1743 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1747 errstring
= N_("cannot read file data");
1752 /* Check .note.ABI-tag if present. */
1753 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1754 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1756 ElfW(Addr
) size
= ph
->p_filesz
;
1758 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1759 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1762 abi_note
= alloca (size
);
1763 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1764 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1768 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1770 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1771 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1772 + ROUND (abi_note
[0])
1773 + ROUND (abi_note
[1]);
1775 if (size
- 32 < note_size
)
1781 abi_note
= (void *) abi_note
+ note_size
;
1787 osversion
= (abi_note
[5] & 0xff) * 65536
1788 + (abi_note
[6] & 0xff) * 256
1789 + (abi_note
[7] & 0xff);
1790 if (abi_note
[4] != __ABI_TAG_OS
1791 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1795 __set_errno (ENOENT
);
1806 /* Try to open NAME in one of the directories in *DIRSP.
1807 Return the fd, or -1. If successful, fill in *REALNAME
1808 with the malloc'd full directory name. If it turns out
1809 that none of the directories in *DIRSP exists, *DIRSP is
1810 replaced with (void *) -1, and the old value is free()d
1811 if MAY_FREE_DIRS is true. */
1814 open_path (const char *name
, size_t namelen
, int preloaded
,
1815 struct r_search_path_struct
*sps
, char **realname
,
1816 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1817 bool *found_other_class
)
1819 struct r_search_path_elem
**dirs
= sps
->dirs
;
1822 const char *current_what
= NULL
;
1825 if (__builtin_expect (dirs
== NULL
, 0))
1826 /* We're called before _dl_init_paths when loading the main executable
1827 given on the command line when rtld is run directly. */
1830 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1833 struct r_search_path_elem
*this_dir
= *dirs
;
1840 /* If we are debugging the search for libraries print the path
1841 now if it hasn't happened now. */
1842 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1843 && current_what
!= this_dir
->what
)
1845 current_what
= this_dir
->what
;
1846 print_search_path (dirs
, current_what
, this_dir
->where
);
1849 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1850 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1852 /* Skip this directory if we know it does not exist. */
1853 if (this_dir
->status
[cnt
] == nonexisting
)
1857 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1862 /* Print name we try if this is wanted. */
1863 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1864 _dl_debug_printf (" trying file=%s\n", buf
);
1866 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1868 if (this_dir
->status
[cnt
] == unknown
)
1871 this_dir
->status
[cnt
] = existing
;
1872 /* Do not update the directory information when loading
1873 auditing code. We must try to disturb the program as
1874 little as possible. */
1875 else if (loader
== NULL
1876 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1878 /* We failed to open machine dependent library. Let's
1879 test whether there is any directory at all. */
1882 buf
[buflen
- namelen
- 1] = '\0';
1884 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1885 || ! S_ISDIR (st
.st_mode
))
1886 /* The directory does not exist or it is no directory. */
1887 this_dir
->status
[cnt
] = nonexisting
;
1889 this_dir
->status
[cnt
] = existing
;
1893 /* Remember whether we found any existing directory. */
1894 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1896 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1897 && INTUSE(__libc_enable_secure
))
1899 /* This is an extra security effort to make sure nobody can
1900 preload broken shared objects which are in the trusted
1901 directories and so exploit the bugs. */
1904 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1905 || (st
.st_mode
& S_ISUID
) == 0)
1907 /* The shared object cannot be tested for being SUID
1908 or this bit is not set. In this case we must not
1912 /* We simply ignore the file, signal this by setting
1913 the error value which would have been set by `open'. */
1921 *realname
= (char *) malloc (buflen
);
1922 if (*realname
!= NULL
)
1924 memcpy (*realname
, buf
, buflen
);
1929 /* No memory for the name, we certainly won't be able
1930 to load and link it. */
1935 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1936 /* The file exists and is readable, but something went wrong. */
1939 /* Remember whether we found anything. */
1942 while (*++dirs
!= NULL
);
1944 /* Remove the whole path if none of the directories exists. */
1945 if (__builtin_expect (! any
, 0))
1947 /* Paths which were allocated using the minimal malloc() in ld.so
1948 must not be freed using the general free() in libc. */
1952 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1954 if (sps
!= &rtld_search_dirs
)
1955 sps
->dirs
= (void *) -1;
1961 /* Map in the shared object file NAME. */
1965 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1966 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1975 assert (nsid
< DL_NNS
);
1977 /* Look for this name among those already loaded. */
1978 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1980 /* If the requested name matches the soname of a loaded object,
1981 use that object. Elide this check for names that have not
1983 if (__builtin_expect (l
->l_faked
, 0) != 0
1984 || __builtin_expect (l
->l_removed
, 0) != 0)
1986 if (!_dl_name_match_p (name
, l
))
1990 if (__builtin_expect (l
->l_soname_added
, 1)
1991 || l
->l_info
[DT_SONAME
] == NULL
)
1994 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1995 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1996 if (strcmp (name
, soname
) != 0)
1999 /* We have a match on a new name -- cache it. */
2000 add_name_to_object (l
, soname
);
2001 l
->l_soname_added
= 1;
2004 /* We have a match. */
2008 /* Display information if we are debugging. */
2009 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2011 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2013 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2016 /* Give the auditing libraries a chance to change the name before we
2018 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2019 && (loader
== NULL
|| loader
->l_auditing
== 0))
2021 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2022 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2024 if (afct
->objsearch
!= NULL
)
2026 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2030 /* Do not try anything further. */
2041 /* Will be true if we found a DSO which is of the other ELF class. */
2042 bool found_other_class
= false;
2044 if (strchr (name
, '/') == NULL
)
2046 /* Search for NAME in several places. */
2048 size_t namelen
= strlen (name
) + 1;
2050 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2051 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2055 /* When the object has the RUNPATH information we don't use any
2057 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2059 /* This is the executable's map (if there is one). Make sure that
2060 we do not look at it twice. */
2061 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2062 bool did_main_map
= false;
2064 /* First try the DT_RPATH of the dependent object that caused NAME
2065 to be loaded. Then that object's dependent, and on up. */
2066 for (l
= loader
; l
; l
= l
->l_loader
)
2067 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2069 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2070 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2071 &found_other_class
);
2075 did_main_map
|= l
== main_map
;
2078 /* If dynamically linked, try the DT_RPATH of the executable
2079 itself. NB: we do this for lookups in any namespace. */
2080 if (fd
== -1 && !did_main_map
2081 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2082 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2084 fd
= open_path (name
, namelen
, preloaded
, &main_map
->l_rpath_dirs
,
2085 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2086 &found_other_class
);
2089 /* Try the LD_LIBRARY_PATH environment variable. */
2090 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2091 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2093 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2094 LA_SER_LIBPATH
, &found_other_class
);
2096 /* Look at the RUNPATH information for this binary. */
2097 if (fd
== -1 && loader
!= NULL
2098 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2099 DT_RUNPATH
, "RUNPATH"))
2100 fd
= open_path (name
, namelen
, preloaded
,
2101 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2102 LA_SER_RUNPATH
, &found_other_class
);
2105 && (__builtin_expect (! preloaded
, 1)
2106 || ! INTUSE(__libc_enable_secure
)))
2108 /* Check the list of libraries in the file /etc/ld.so.cache,
2109 for compatibility with Linux's ldconfig program. */
2110 const char *cached
= _dl_load_cache_lookup (name
);
2115 // XXX Correct to unconditionally default to namespace 0?
2116 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2121 /* If the loader has the DF_1_NODEFLIB flag set we must not
2122 use a cache entry from any of these directories. */
2125 /* 'l' is always != NULL for dynamically linked objects. */
2128 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2130 const char *dirp
= system_dirs
;
2131 unsigned int cnt
= 0;
2135 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2137 /* The prefix matches. Don't use the entry. */
2142 dirp
+= system_dirs_len
[cnt
] + 1;
2145 while (cnt
< nsystem_dirs_len
);
2150 fd
= open_verify (cached
,
2151 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2152 LA_SER_CONFIG
, &found_other_class
, false);
2153 if (__builtin_expect (fd
!= -1, 1))
2155 realname
= local_strdup (cached
);
2156 if (realname
== NULL
)
2166 /* Finally, try the default path. */
2168 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2169 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2170 && rtld_search_dirs
.dirs
!= (void *) -1)
2171 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2172 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2174 /* Add another newline when we are tracing the library loading. */
2175 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2176 _dl_debug_printf ("\n");
2180 /* The path may contain dynamic string tokens. */
2182 ? expand_dynamic_string_token (loader
, name
)
2183 : local_strdup (name
));
2184 if (realname
== NULL
)
2188 fd
= open_verify (realname
, &fb
,
2189 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2190 &found_other_class
, true);
2191 if (__builtin_expect (fd
, 0) == -1)
2199 /* In case the LOADER information has only been provided to get to
2200 the appropriate RUNPATH/RPATH information we do not need it
2202 if (mode
& __RTLD_CALLMAP
)
2205 if (__builtin_expect (fd
, 0) == -1)
2208 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2210 /* We haven't found an appropriate library. But since we
2211 are only interested in the list of libraries this isn't
2212 so severe. Fake an entry with all the information we
2214 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2216 /* Enter the new object in the list of loaded objects. */
2217 if ((name_copy
= local_strdup (name
)) == NULL
2218 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2219 mode
, nsid
)) == NULL
)
2222 _dl_signal_error (ENOMEM
, name
, NULL
,
2223 N_("cannot create shared object descriptor"));
2225 /* Signal that this is a faked entry. */
2227 /* Since the descriptor is initialized with zero we do not
2229 l->l_reserved = 0; */
2230 l
->l_buckets
= &dummy_bucket
;
2236 else if (found_other_class
)
2237 _dl_signal_error (0, name
, NULL
,
2238 ELFW(CLASS
) == ELFCLASS32
2239 ? N_("wrong ELF class: ELFCLASS64")
2240 : N_("wrong ELF class: ELFCLASS32"));
2242 _dl_signal_error (errno
, name
, NULL
,
2243 N_("cannot open shared object file"));
2246 void *stack_end
= __libc_stack_end
;
2247 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2254 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2262 unsigned int idx
= 0;
2263 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2264 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2265 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2267 if (sps
->dirs
!= (void *) -1)
2269 struct r_search_path_elem
**dirs
= sps
->dirs
;
2272 const struct r_search_path_elem
*const r
= *dirs
++;
2276 si
->dls_size
+= r
->dirnamelen
;
2280 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2281 sp
->dls_name
= allocptr
;
2282 allocptr
= __mempcpy (allocptr
,
2283 r
->dirname
, r
->dirnamelen
- 1);
2285 sp
->dls_flags
= flags
;
2288 while (*dirs
!= NULL
);
2292 /* When the object has the RUNPATH information we don't use any RPATHs. */
2293 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2295 /* First try the DT_RPATH of the dependent object that caused NAME
2296 to be loaded. Then that object's dependent, and on up. */
2298 struct link_map
*l
= loader
;
2301 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2302 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2307 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2308 if (loader
->l_ns
== LM_ID_BASE
)
2310 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2311 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2312 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2313 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2317 /* Try the LD_LIBRARY_PATH environment variable. */
2318 add_path (&env_path_list
, XXX_ENV
);
2320 /* Look at the RUNPATH information for this binary. */
2321 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2322 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2325 Here is where ld.so.cache gets checked, but we don't have
2326 a way to indicate that in the results for Dl_serinfo. */
2328 /* Finally, try the default path. */
2329 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2330 add_path (&rtld_search_dirs
, XXX_default
);
2333 /* Count the struct size before the string area, which we didn't
2334 know before we completed dls_cnt. */
2335 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;