1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006 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 result
= calloc (1, sizeof *result
);
553 errstring
= N_("cannot create cache for search path");
555 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
564 while (*inhp
!= '\0')
568 while (*inhp
!= '\0');
571 /* Make a writable copy. At the same time expand possible dynamic
573 copy
= expand_dynamic_string_token (l
, rpath
);
576 errstring
= N_("cannot create RUNPATH/RPATH copy");
580 /* Count the number of necessary elements in the result array. */
582 for (cp
= copy
; *cp
!= '\0'; ++cp
)
586 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
587 number of necessary entries. */
588 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
591 goto signal_error_cache
;
593 fillin_rpath (copy
, result
, ":", 0, what
, where
);
595 /* Free the copied RPATH string. `fillin_rpath' make own copies if
600 /* The caller will change this value if we haven't used a real malloc. */
604 /* Make sure cached path information is stored in *SP
605 and return true if there are any paths to search there. */
607 cache_rpath (struct link_map
*l
,
608 struct r_search_path_struct
*sp
,
612 if (sp
->dirs
== (void *) -1)
615 if (sp
->dirs
!= NULL
)
618 if (l
->l_info
[tag
] == NULL
)
620 /* There is no path. */
621 sp
->dirs
= (void *) -1;
625 /* Make sure the cache information is available. */
626 decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
627 + l
->l_info
[tag
]->d_un
.d_val
),
635 _dl_init_paths (const char *llp
)
639 struct r_search_path_elem
*pelem
, **aelem
;
644 /* Initialize to please the compiler. */
645 const char *errstring
= NULL
;
647 /* Fill in the information about the application's RPATH and the
648 directories addressed by the LD_LIBRARY_PATH environment variable. */
650 /* Get the capabilities. */
651 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
652 &ncapstr
, &max_capstrlen
);
654 /* First set up the rest of the default search directory entries. */
655 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
656 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
657 if (rtld_search_dirs
.dirs
== NULL
)
659 errstring
= N_("cannot create search path array");
661 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
664 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
665 + ncapstr
* sizeof (enum r_dir_status
))
666 / sizeof (struct r_search_path_elem
));
668 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
669 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
670 * round_size
* sizeof (struct r_search_path_elem
));
671 if (rtld_search_dirs
.dirs
[0] == NULL
)
673 errstring
= N_("cannot create cache for search path");
677 rtld_search_dirs
.malloced
= 0;
678 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
688 pelem
->what
= "system search path";
691 pelem
->dirname
= strp
;
692 pelem
->dirnamelen
= system_dirs_len
[idx
];
693 strp
+= system_dirs_len
[idx
] + 1;
695 /* System paths must be absolute. */
696 assert (pelem
->dirname
[0] == '/');
697 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
698 pelem
->status
[cnt
] = unknown
;
700 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
704 while (idx
< nsystem_dirs_len
);
706 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
710 /* This points to the map of the main object. */
711 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
714 assert (l
->l_type
!= lt_loaded
);
716 if (l
->l_info
[DT_RUNPATH
])
718 /* Allocate room for the search path and fill in information
720 decompose_rpath (&l
->l_runpath_dirs
,
721 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
722 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
725 /* The RPATH is ignored. */
726 l
->l_rpath_dirs
.dirs
= (void *) -1;
730 l
->l_runpath_dirs
.dirs
= (void *) -1;
732 if (l
->l_info
[DT_RPATH
])
734 /* Allocate room for the search path and fill in information
736 decompose_rpath (&l
->l_rpath_dirs
,
737 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
738 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
740 l
->l_rpath_dirs
.malloced
= 0;
743 l
->l_rpath_dirs
.dirs
= (void *) -1;
748 if (llp
!= NULL
&& *llp
!= '\0')
751 const char *cp
= llp
;
752 char *llp_tmp
= strdupa (llp
);
754 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
759 if (*cp
== ':' || *cp
== ';')
764 env_path_list
.dirs
= (struct r_search_path_elem
**)
765 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
766 if (env_path_list
.dirs
== NULL
)
768 errstring
= N_("cannot create cache for search path");
772 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
773 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
776 if (env_path_list
.dirs
[0] == NULL
)
778 free (env_path_list
.dirs
);
779 env_path_list
.dirs
= (void *) -1;
782 env_path_list
.malloced
= 0;
785 env_path_list
.dirs
= (void *) -1;
787 /* Remember the last search directory added at startup. */
788 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
793 __attribute__ ((noreturn
, noinline
))
794 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
795 const char *msg
, struct r_debug
*r
)
797 /* The file might already be closed. */
802 /* Remove the stillborn object from the list and free it. */
803 assert (l
->l_next
== NULL
);
804 if (l
->l_prev
== NULL
)
805 /* No other module loaded. This happens only in the static library,
806 or in rtld under --verify. */
807 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
809 l
->l_prev
->l_next
= NULL
;
810 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
817 r
->r_state
= RT_CONSISTENT
;
821 _dl_signal_error (code
, name
, NULL
, msg
);
825 /* Map in the shared object NAME, actually located in REALNAME, and already
828 #ifndef EXTERNAL_MAP_FROM_FD
832 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
833 char *realname
, struct link_map
*loader
, int l_type
,
834 int mode
, void **stack_endp
, Lmid_t nsid
)
836 struct link_map
*l
= NULL
;
837 const ElfW(Ehdr
) *header
;
838 const ElfW(Phdr
) *phdr
;
839 const ElfW(Phdr
) *ph
;
843 /* Initialize to keep the compiler happy. */
844 const char *errstring
= NULL
;
846 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
847 bool make_consistent
= false;
849 /* Get file information. */
850 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
852 errstring
= N_("cannot stat shared object");
856 lose (errval
, fd
, name
, realname
, l
, errstring
,
857 make_consistent
? r
: NULL
);
860 /* Look again to see if the real name matched another already loaded. */
861 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
862 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
864 /* The object is already loaded.
865 Just bump its reference count and return it. */
868 /* If the name is not in the list of names for this object add
871 add_name_to_object (l
, name
);
877 /* When loading into a namespace other than the base one we must
878 avoid loading ld.so since there can only be one copy. Ever. */
879 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
880 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
881 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
882 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
884 /* This is indeed ld.so. Create a new link_map which refers to
885 the real one for almost everything. */
886 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
890 /* Refer to the real descriptor. */
891 l
->l_real
= &GL(dl_rtld_map
);
893 /* No need to bump the refcount of the real object, ld.so will
894 never be unloaded. */
901 if (mode
& RTLD_NOLOAD
)
902 /* We are not supposed to load the object unless it is already
903 loaded. So return now. */
906 /* Print debugging message. */
907 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
908 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
910 /* This is the ELF header. We read it in `open_verify'. */
911 header
= (void *) fbp
->buf
;
915 if (_dl_zerofd
== -1)
917 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
918 if (_dl_zerofd
== -1)
921 _dl_signal_error (errno
, NULL
, NULL
,
922 N_("cannot open zero fill device"));
927 /* Signal that we are going to add new objects. */
928 if (r
->r_state
== RT_CONSISTENT
)
931 /* Auditing checkpoint: we are going to add new objects. */
932 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
934 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
935 /* Do not call the functions for any auditing object. */
936 if (head
->l_auditing
== 0)
938 struct audit_ifaces
*afct
= GLRO(dl_audit
);
939 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
941 if (afct
->activity
!= NULL
)
942 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
950 /* Notify the debugger we have added some objects. We need to
951 call _dl_debug_initialize in a static program in case dynamic
952 linking has not been used before. */
955 make_consistent
= true;
958 assert (r
->r_state
== RT_ADD
);
960 /* Enter the new object in the list of loaded objects. */
961 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
962 if (__builtin_expect (l
== NULL
, 0))
967 errstring
= N_("cannot create shared object descriptor");
968 goto call_lose_errno
;
971 /* Extract the remaining details we need from the ELF header
972 and then read in the program header table. */
973 l
->l_entry
= header
->e_entry
;
974 type
= header
->e_type
;
975 l
->l_phnum
= header
->e_phnum
;
977 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
978 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
979 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
982 phdr
= alloca (maplength
);
983 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
984 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
986 errstring
= N_("cannot read file data");
987 goto call_lose_errno
;
991 /* Presumed absent PT_GNU_STACK. */
992 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
995 /* Scan the program header table, collecting its load commands. */
998 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1001 } loadcmds
[l
->l_phnum
], *c
;
1002 size_t nloadcmds
= 0;
1003 bool has_holes
= false;
1005 /* The struct is initialized to zero so this is not necessary:
1009 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1012 /* These entries tell us where to find things once the file's
1013 segments are mapped in. We record the addresses it says
1014 verbatim, and later correct for the run-time load address. */
1016 l
->l_ld
= (void *) ph
->p_vaddr
;
1017 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1021 l
->l_phdr
= (void *) ph
->p_vaddr
;
1025 /* A load command tells us to map in part of the file.
1026 We record the load commands and process them all later. */
1027 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1030 errstring
= N_("ELF load command alignment not page-aligned");
1033 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1034 & (ph
->p_align
- 1)) != 0, 0))
1037 = N_("ELF load command address/offset not properly aligned");
1041 c
= &loadcmds
[nloadcmds
++];
1042 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1043 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1044 & ~(GLRO(dl_pagesize
) - 1));
1045 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1046 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1047 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1049 /* Determine whether there is a gap between the last segment
1051 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1054 /* Optimize a common case. */
1055 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1056 c
->prot
= (PF_TO_PROT
1057 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1060 if (ph
->p_flags
& PF_R
)
1061 c
->prot
|= PROT_READ
;
1062 if (ph
->p_flags
& PF_W
)
1063 c
->prot
|= PROT_WRITE
;
1064 if (ph
->p_flags
& PF_X
)
1065 c
->prot
|= PROT_EXEC
;
1071 if (ph
->p_memsz
== 0)
1072 /* Nothing to do for an empty segment. */
1075 l
->l_tls_blocksize
= ph
->p_memsz
;
1076 l
->l_tls_align
= ph
->p_align
;
1077 if (ph
->p_align
== 0)
1078 l
->l_tls_firstbyte_offset
= 0;
1080 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1081 l
->l_tls_initimage_size
= ph
->p_filesz
;
1082 /* Since we don't know the load address yet only store the
1083 offset. We will adjust it later. */
1084 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1086 /* If not loading the initial set of shared libraries,
1087 check whether we should permit loading a TLS segment. */
1088 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1089 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1090 not set up TLS data structures, so don't use them now. */
1091 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1093 /* Assign the next available module ID. */
1094 l
->l_tls_modid
= _dl_next_tls_modid ();
1099 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1100 /* We are loading the executable itself when the dynamic linker
1101 was executed directly. The setup will happen later. */
1104 /* In a static binary there is no way to tell if we dynamically
1105 loaded libpthread. */
1106 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1109 /* We have not yet loaded libpthread.
1110 We can do the TLS setup right now! */
1114 /* The first call allocates TLS bookkeeping data structures.
1115 Then we allocate the TCB for the initial thread. */
1116 if (__builtin_expect (_dl_tls_setup (), 0)
1117 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1122 cannot allocate TLS data structures for initial thread");
1126 /* Now we install the TCB in the thread register. */
1127 errstring
= TLS_INIT_TP (tcb
, 0);
1128 if (__builtin_expect (errstring
== NULL
, 1))
1130 /* Now we are all good. */
1131 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1135 /* The kernel is too old or somesuch. */
1137 _dl_deallocate_tls (tcb
, 1);
1142 /* Uh-oh, the binary expects TLS support but we cannot
1145 errstring
= N_("cannot handle TLS data");
1150 stack_flags
= ph
->p_flags
;
1154 l
->l_relro_addr
= ph
->p_vaddr
;
1155 l
->l_relro_size
= ph
->p_memsz
;
1159 if (__builtin_expect (nloadcmds
== 0, 0))
1161 /* This only happens for a bogus object that will be caught with
1162 another error below. But we don't want to go through the
1163 calculations below using NLOADCMDS - 1. */
1164 errstring
= N_("object file has no loadable segments");
1168 /* Now process the load commands and map segments into memory. */
1171 /* Length of the sections to be loaded. */
1172 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1174 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1176 /* This is a position-independent shared object. We can let the
1177 kernel map it anywhere it likes, but we must have space for all
1178 the segments in their specified positions relative to the first.
1179 So we map the first segment without MAP_FIXED, but with its
1180 extent increased to cover all the segments. Then we remove
1181 access from excess portion, and there is known sufficient space
1182 there to remap from the later segments.
1184 As a refinement, sometimes we have an address that we would
1185 prefer to map such objects at; but this is only a preference,
1186 the OS can do whatever it likes. */
1188 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1189 c
->mapstart
& GLRO(dl_use_load_bias
))
1190 - MAP_BASE_ADDR (l
));
1192 /* Remember which part of the address space this object uses. */
1193 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1197 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1200 errstring
= N_("failed to map segment from shared object");
1201 goto call_lose_errno
;
1204 l
->l_map_end
= l
->l_map_start
+ maplength
;
1205 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1208 /* Change protection on the excess portion to disallow all access;
1209 the portions we do not remap later will be inaccessible as if
1210 unallocated. Then jump into the normal segment-mapping loop to
1211 handle the portion of the segment past the end of the file
1213 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1214 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1220 /* This object is loaded at a fixed address. This must never
1221 happen for objects loaded with dlopen(). */
1222 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1224 errstring
= N_("cannot dynamically load executable");
1228 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1230 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1233 /* Remember which part of the address space this object uses. */
1234 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1235 l
->l_map_end
= l
->l_map_start
+ maplength
;
1237 while (c
< &loadcmds
[nloadcmds
])
1239 if (c
->mapend
> c
->mapstart
1240 /* Map the segment contents from the file. */
1241 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1242 c
->mapend
- c
->mapstart
, c
->prot
,
1243 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1249 if (c
->prot
& PROT_EXEC
)
1250 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1253 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1254 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1255 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1256 /* Found the program header in this segment. */
1257 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1259 if (c
->allocend
> c
->dataend
)
1261 /* Extra zero pages should appear at the end of this segment,
1262 after the data mapped from the file. */
1263 ElfW(Addr
) zero
, zeroend
, zeropage
;
1265 zero
= l
->l_addr
+ c
->dataend
;
1266 zeroend
= l
->l_addr
+ c
->allocend
;
1267 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1268 & ~(GLRO(dl_pagesize
) - 1));
1270 if (zeroend
< zeropage
)
1271 /* All the extra data is in the last page of the segment.
1272 We can just zero it. */
1275 if (zeropage
> zero
)
1277 /* Zero the final part of the last page of the segment. */
1278 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1281 if (__mprotect ((caddr_t
) (zero
1282 & ~(GLRO(dl_pagesize
) - 1)),
1283 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1285 errstring
= N_("cannot change memory protections");
1286 goto call_lose_errno
;
1289 memset ((void *) zero
, '\0', zeropage
- zero
);
1290 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1291 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1292 GLRO(dl_pagesize
), c
->prot
);
1295 if (zeroend
> zeropage
)
1297 /* Map the remaining zero pages in from the zero fill FD. */
1299 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1300 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1302 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1304 errstring
= N_("cannot map zero-fill pages");
1305 goto call_lose_errno
;
1316 if (__builtin_expect (type
== ET_DYN
, 0))
1318 errstring
= N_("object file has no dynamic section");
1323 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1325 elf_get_dynamic_info (l
, NULL
);
1327 /* Make sure we are not dlopen'ing an object that has the
1328 DF_1_NOOPEN flag set. */
1329 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1330 && (mode
& __RTLD_DLOPEN
))
1332 /* We are not supposed to load this object. Free all resources. */
1333 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1335 if (!l
->l_libname
->dont_free
)
1336 free (l
->l_libname
);
1338 if (l
->l_phdr_allocated
)
1339 free ((void *) l
->l_phdr
);
1341 errstring
= N_("shared object cannot be dlopen()ed");
1345 if (l
->l_phdr
== NULL
)
1347 /* The program header is not contained in any of the segments.
1348 We have to allocate memory ourself and copy it over from out
1350 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1351 * sizeof (ElfW(Phdr
)));
1354 errstring
= N_("cannot allocate memory for program header");
1355 goto call_lose_errno
;
1358 l
->l_phdr
= memcpy (newp
, phdr
,
1359 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1360 l
->l_phdr_allocated
= 1;
1363 /* Adjust the PT_PHDR value by the runtime load address. */
1364 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1366 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1368 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1371 errstring
= N_("invalid caller");
1375 /* The stack is presently not executable, but this module
1376 requires that it be executable. We must change the
1377 protection of the variable which contains the flags used in
1378 the mprotect calls. */
1379 #if defined HAVE_Z_RELRO && defined SHARED
1380 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1382 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1383 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1385 struct link_map
*const m
= &GL(dl_rtld_map
);
1386 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1388 & -GLRO(dl_pagesize
));
1389 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1391 /* The variable lies in the region protected by RELRO. */
1392 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1393 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1394 __mprotect ((void *) p
, s
, PROT_READ
);
1397 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1401 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1403 #ifdef check_consistency
1404 check_consistency ();
1407 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1411 cannot enable executable stack as shared object requires");
1417 /* Adjust the address of the TLS initialization image. */
1418 if (l
->l_tls_initimage
!= NULL
)
1419 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1422 /* We are done mapping in the file. We no longer need the descriptor. */
1423 if (__builtin_expect (__close (fd
) != 0, 0))
1425 errstring
= N_("cannot close file descriptor");
1426 goto call_lose_errno
;
1428 /* Signal that we closed the file. */
1431 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1432 l
->l_type
= lt_executable
;
1434 l
->l_entry
+= l
->l_addr
;
1436 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1437 _dl_debug_printf ("\
1438 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1439 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1440 (int) sizeof (void *) * 2,
1441 (unsigned long int) l
->l_ld
,
1442 (int) sizeof (void *) * 2,
1443 (unsigned long int) l
->l_addr
,
1444 (int) sizeof (void *) * 2, maplength
,
1445 (int) sizeof (void *) * 2,
1446 (unsigned long int) l
->l_entry
,
1447 (int) sizeof (void *) * 2,
1448 (unsigned long int) l
->l_phdr
,
1449 (int) sizeof (void *) * 2, l
->l_phnum
);
1451 /* Set up the symbol hash table. */
1454 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1455 have to do this for the main map. */
1456 if ((mode
& RTLD_DEEPBIND
) == 0
1457 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1458 && &l
->l_searchlist
!= l
->l_scope
[0])
1460 /* Create an appropriate searchlist. It contains only this map.
1461 This is the definition of DT_SYMBOLIC in SysVr4. */
1462 l
->l_symbolic_searchlist
.r_list
=
1463 (struct link_map
**) malloc (sizeof (struct link_map
*));
1465 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1467 errstring
= N_("cannot create searchlist");
1468 goto call_lose_errno
;
1471 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1472 l
->l_symbolic_searchlist
.r_nlist
= 1;
1474 /* Now move the existing entries one back. */
1475 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1476 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1478 /* Now add the new entry. */
1479 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1482 /* Remember whether this object must be initialized first. */
1483 if (l
->l_flags_1
& DF_1_INITFIRST
)
1484 GL(dl_initfirst
) = l
;
1486 /* Finally the file information. */
1487 l
->l_dev
= st
.st_dev
;
1488 l
->l_ino
= st
.st_ino
;
1490 /* When we profile the SONAME might be needed for something else but
1491 loading. Add it right away. */
1492 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1493 && l
->l_info
[DT_SONAME
] != NULL
)
1494 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1495 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1498 /* Auditing checkpoint: we have a new object. */
1499 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1500 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1502 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1503 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1505 if (afct
->objopen
!= NULL
)
1507 l
->l_audit
[cnt
].bindflags
1508 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1510 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1521 /* Print search path. */
1523 print_search_path (struct r_search_path_elem
**list
,
1524 const char *what
, const char *name
)
1526 char buf
[max_dirnamelen
+ max_capstrlen
];
1529 _dl_debug_printf (" search path=");
1531 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1533 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1536 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1537 if ((*list
)->status
[cnt
] != nonexisting
)
1539 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1540 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1545 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1553 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1554 name
[0] ? name
: rtld_progname
);
1556 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1559 /* Open a file and verify it is an ELF file for this architecture. We
1560 ignore only ELF files for other architectures. Non-ELF files and
1561 ELF files with different header information cause fatal errors since
1562 this could mean there is something wrong in the installation and the
1563 user might want to know about this. */
1565 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1566 int whatcode
, bool *found_other_class
, bool free_name
)
1568 /* This is the expected ELF header. */
1569 #define ELF32_CLASS ELFCLASS32
1570 #define ELF64_CLASS ELFCLASS64
1571 #ifndef VALID_ELF_HEADER
1572 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1573 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1574 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1576 static const unsigned char expected
[EI_PAD
] =
1578 [EI_MAG0
] = ELFMAG0
,
1579 [EI_MAG1
] = ELFMAG1
,
1580 [EI_MAG2
] = ELFMAG2
,
1581 [EI_MAG3
] = ELFMAG3
,
1582 [EI_CLASS
] = ELFW(CLASS
),
1583 [EI_DATA
] = byteorder
,
1584 [EI_VERSION
] = EV_CURRENT
,
1585 [EI_OSABI
] = ELFOSABI_SYSV
,
1590 ElfW(Word
) vendorlen
;
1594 } expected_note
= { 4, 16, 1, "GNU" };
1595 /* Initialize it to make the compiler happy. */
1596 const char *errstring
= NULL
;
1600 /* Give the auditing libraries a chance. */
1601 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1602 && loader
->l_auditing
== 0)
1604 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1605 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1607 if (afct
->objsearch
!= NULL
)
1609 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1612 /* Ignore the path. */
1621 /* Open the file. We always open files read-only. */
1622 int fd
= __open (name
, O_RDONLY
);
1626 ElfW(Phdr
) *phdr
, *ph
;
1627 ElfW(Word
) *abi_note
, abi_note_buf
[8];
1628 unsigned int osversion
;
1631 /* We successfully openened the file. Now verify it is a file
1634 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1636 /* This is where the ELF header is loaded. */
1637 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1638 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1640 /* Now run the tests. */
1641 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1644 errstring
= (errval
== 0
1645 ? N_("file too short") : N_("cannot read file data"));
1649 char *realname
= (char *) name
;
1650 name
= strdupa (realname
);
1653 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1656 /* See whether the ELF header is what we expect. */
1657 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1660 /* Something is wrong. */
1661 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1662 #if BYTE_ORDER == LITTLE_ENDIAN
1663 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1664 (ELFMAG1
<< (EI_MAG1
* 8)) |
1665 (ELFMAG2
<< (EI_MAG2
* 8)) |
1666 (ELFMAG3
<< (EI_MAG3
* 8)))
1668 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1669 (ELFMAG1
<< (EI_MAG2
* 8)) |
1670 (ELFMAG2
<< (EI_MAG1
* 8)) |
1671 (ELFMAG3
<< (EI_MAG0
* 8)))
1674 errstring
= N_("invalid ELF header");
1675 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1677 /* This is not a fatal error. On architectures where
1678 32-bit and 64-bit binaries can be run this might
1680 *found_other_class
= true;
1683 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1685 if (BYTE_ORDER
== BIG_ENDIAN
)
1686 errstring
= N_("ELF file data encoding not big-endian");
1688 errstring
= N_("ELF file data encoding not little-endian");
1690 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1692 = N_("ELF file version ident does not match current one");
1693 /* XXX We should be able so set system specific versions which are
1695 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1696 errstring
= N_("ELF file OS ABI invalid");
1697 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1698 errstring
= N_("ELF file ABI version invalid");
1700 /* Otherwise we don't know what went wrong. */
1701 errstring
= N_("internal error");
1706 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1708 errstring
= N_("ELF file version does not match current one");
1711 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1713 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1714 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1716 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1719 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1720 != sizeof (ElfW(Phdr
)))
1722 errstring
= N_("ELF file's phentsize not the expected size");
1726 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1727 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1728 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1731 phdr
= alloca (maplength
);
1732 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1733 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1737 errstring
= N_("cannot read file data");
1742 /* Check .note.ABI-tag if present. */
1743 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1744 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
== 32 && ph
->p_align
>= 4)
1746 if (ph
->p_offset
+ 32 <= (size_t) fbp
->len
)
1747 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1750 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1751 if (__libc_read (fd
, (void *) abi_note_buf
, 32) != 32)
1754 abi_note
= abi_note_buf
;
1757 if (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1760 osversion
= (abi_note
[5] & 0xff) * 65536
1761 + (abi_note
[6] & 0xff) * 256
1762 + (abi_note
[7] & 0xff);
1763 if (abi_note
[4] != __ABI_TAG_OS
1764 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1768 __set_errno (ENOENT
);
1779 /* Try to open NAME in one of the directories in *DIRSP.
1780 Return the fd, or -1. If successful, fill in *REALNAME
1781 with the malloc'd full directory name. If it turns out
1782 that none of the directories in *DIRSP exists, *DIRSP is
1783 replaced with (void *) -1, and the old value is free()d
1784 if MAY_FREE_DIRS is true. */
1787 open_path (const char *name
, size_t namelen
, int preloaded
,
1788 struct r_search_path_struct
*sps
, char **realname
,
1789 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1790 bool *found_other_class
)
1792 struct r_search_path_elem
**dirs
= sps
->dirs
;
1795 const char *current_what
= NULL
;
1798 if (__builtin_expect (dirs
== NULL
, 0))
1799 /* We're called before _dl_init_paths when loading the main executable
1800 given on the command line when rtld is run directly. */
1803 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1806 struct r_search_path_elem
*this_dir
= *dirs
;
1813 /* If we are debugging the search for libraries print the path
1814 now if it hasn't happened now. */
1815 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1816 && current_what
!= this_dir
->what
)
1818 current_what
= this_dir
->what
;
1819 print_search_path (dirs
, current_what
, this_dir
->where
);
1822 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1823 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1825 /* Skip this directory if we know it does not exist. */
1826 if (this_dir
->status
[cnt
] == nonexisting
)
1830 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1835 /* Print name we try if this is wanted. */
1836 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1837 _dl_debug_printf (" trying file=%s\n", buf
);
1839 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1841 if (this_dir
->status
[cnt
] == unknown
)
1844 this_dir
->status
[cnt
] = existing
;
1845 /* Do not update the directory information when loading
1846 auditing code. We must try to disturb the program as
1847 little as possible. */
1848 else if (loader
== NULL
1849 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_audit
== 0)
1851 /* We failed to open machine dependent library. Let's
1852 test whether there is any directory at all. */
1855 buf
[buflen
- namelen
- 1] = '\0';
1857 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1858 || ! S_ISDIR (st
.st_mode
))
1859 /* The directory does not exist or it is no directory. */
1860 this_dir
->status
[cnt
] = nonexisting
;
1862 this_dir
->status
[cnt
] = existing
;
1866 /* Remember whether we found any existing directory. */
1867 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1869 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1870 && INTUSE(__libc_enable_secure
))
1872 /* This is an extra security effort to make sure nobody can
1873 preload broken shared objects which are in the trusted
1874 directories and so exploit the bugs. */
1877 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1878 || (st
.st_mode
& S_ISUID
) == 0)
1880 /* The shared object cannot be tested for being SUID
1881 or this bit is not set. In this case we must not
1885 /* We simply ignore the file, signal this by setting
1886 the error value which would have been set by `open'. */
1894 *realname
= (char *) malloc (buflen
);
1895 if (*realname
!= NULL
)
1897 memcpy (*realname
, buf
, buflen
);
1902 /* No memory for the name, we certainly won't be able
1903 to load and link it. */
1908 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1909 /* The file exists and is readable, but something went wrong. */
1912 /* Remember whether we found anything. */
1915 while (*++dirs
!= NULL
);
1917 /* Remove the whole path if none of the directories exists. */
1918 if (__builtin_expect (! any
, 0))
1920 /* Paths which were allocated using the minimal malloc() in ld.so
1921 must not be freed using the general free() in libc. */
1925 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1927 if (sps
!= &rtld_search_dirs
)
1929 sps
->dirs
= (void *) -1;
1935 /* Map in the shared object file NAME. */
1939 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1940 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1949 assert (nsid
< DL_NNS
);
1951 /* Look for this name among those already loaded. */
1952 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1954 /* If the requested name matches the soname of a loaded object,
1955 use that object. Elide this check for names that have not
1957 if (__builtin_expect (l
->l_faked
, 0) != 0
1958 || __builtin_expect (l
->l_removed
, 0) != 0)
1960 if (!_dl_name_match_p (name
, l
))
1964 if (__builtin_expect (l
->l_soname_added
, 1)
1965 || l
->l_info
[DT_SONAME
] == NULL
)
1968 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1969 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1970 if (strcmp (name
, soname
) != 0)
1973 /* We have a match on a new name -- cache it. */
1974 add_name_to_object (l
, soname
);
1975 l
->l_soname_added
= 1;
1978 /* We have a match. */
1982 /* Display information if we are debugging. */
1983 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
1985 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
1987 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
1990 /* Give the auditing libraries a chance to change the name before we
1992 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1993 && (loader
== NULL
|| loader
->l_auditing
== 0))
1995 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1996 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1998 if (afct
->objsearch
!= NULL
)
2000 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2004 /* Do not try anything further. */
2015 /* Will be true if we found a DSO which is of the other ELF class. */
2016 bool found_other_class
= false;
2018 if (strchr (name
, '/') == NULL
)
2020 /* Search for NAME in several places. */
2022 size_t namelen
= strlen (name
) + 1;
2024 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2025 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2029 /* When the object has the RUNPATH information we don't use any
2031 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2033 /* First try the DT_RPATH of the dependent object that caused NAME
2034 to be loaded. Then that object's dependent, and on up. */
2035 for (l
= loader
; fd
== -1 && l
; l
= l
->l_loader
)
2036 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2037 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2038 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2039 &found_other_class
);
2041 /* If dynamically linked, try the DT_RPATH of the executable
2042 itself. NB: we do this for lookups in any namespace. */
2045 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2046 if (l
&& l
->l_type
!= lt_loaded
&& l
!= loader
2047 && cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2048 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2049 &realname
, &fb
, loader
?: l
, LA_SER_RUNPATH
,
2050 &found_other_class
);
2054 /* Try the LD_LIBRARY_PATH environment variable. */
2055 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2056 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2058 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2059 LA_SER_LIBPATH
, &found_other_class
);
2061 /* Look at the RUNPATH information for this binary. */
2062 if (fd
== -1 && loader
!= NULL
2063 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2064 DT_RUNPATH
, "RUNPATH"))
2065 fd
= open_path (name
, namelen
, preloaded
,
2066 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2067 LA_SER_RUNPATH
, &found_other_class
);
2070 && (__builtin_expect (! preloaded
, 1)
2071 || ! INTUSE(__libc_enable_secure
)))
2073 /* Check the list of libraries in the file /etc/ld.so.cache,
2074 for compatibility with Linux's ldconfig program. */
2075 const char *cached
= _dl_load_cache_lookup (name
);
2080 // XXX Correct to unconditionally default to namespace 0?
2081 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2086 /* If the loader has the DF_1_NODEFLIB flag set we must not
2087 use a cache entry from any of these directories. */
2090 /* 'l' is always != NULL for dynamically linked objects. */
2093 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2095 const char *dirp
= system_dirs
;
2096 unsigned int cnt
= 0;
2100 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2102 /* The prefix matches. Don't use the entry. */
2107 dirp
+= system_dirs_len
[cnt
] + 1;
2110 while (cnt
< nsystem_dirs_len
);
2115 fd
= open_verify (cached
,
2116 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2117 LA_SER_CONFIG
, &found_other_class
, false);
2118 if (__builtin_expect (fd
!= -1, 1))
2120 realname
= local_strdup (cached
);
2121 if (realname
== NULL
)
2131 /* Finally, try the default path. */
2133 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2134 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2135 && rtld_search_dirs
.dirs
!= (void *) -1)
2136 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2137 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2139 /* Add another newline when we are tracing the library loading. */
2140 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2141 _dl_debug_printf ("\n");
2145 /* The path may contain dynamic string tokens. */
2147 ? expand_dynamic_string_token (loader
, name
)
2148 : local_strdup (name
));
2149 if (realname
== NULL
)
2153 fd
= open_verify (realname
, &fb
,
2154 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2155 &found_other_class
, true);
2156 if (__builtin_expect (fd
, 0) == -1)
2164 /* In case the LOADER information has only been provided to get to
2165 the appropriate RUNPATH/RPATH information we do not need it
2167 if (mode
& __RTLD_CALLMAP
)
2170 if (__builtin_expect (fd
, 0) == -1)
2173 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2175 /* We haven't found an appropriate library. But since we
2176 are only interested in the list of libraries this isn't
2177 so severe. Fake an entry with all the information we
2179 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2181 /* Enter the new object in the list of loaded objects. */
2182 if ((name_copy
= local_strdup (name
)) == NULL
2183 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2184 mode
, nsid
)) == NULL
)
2187 _dl_signal_error (ENOMEM
, name
, NULL
,
2188 N_("cannot create shared object descriptor"));
2190 /* Signal that this is a faked entry. */
2192 /* Since the descriptor is initialized with zero we do not
2194 l->l_reserved = 0; */
2195 l
->l_buckets
= &dummy_bucket
;
2201 else if (found_other_class
)
2202 _dl_signal_error (0, name
, NULL
,
2203 ELFW(CLASS
) == ELFCLASS32
2204 ? N_("wrong ELF class: ELFCLASS64")
2205 : N_("wrong ELF class: ELFCLASS32"));
2207 _dl_signal_error (errno
, name
, NULL
,
2208 N_("cannot open shared object file"));
2211 void *stack_end
= __libc_stack_end
;
2212 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2219 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2227 unsigned int idx
= 0;
2228 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2229 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2230 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2232 if (sps
->dirs
!= (void *) -1)
2234 struct r_search_path_elem
**dirs
= sps
->dirs
;
2237 const struct r_search_path_elem
*const r
= *dirs
++;
2241 si
->dls_size
+= r
->dirnamelen
;
2245 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2246 sp
->dls_name
= allocptr
;
2247 allocptr
= __mempcpy (allocptr
,
2248 r
->dirname
, r
->dirnamelen
- 1);
2250 sp
->dls_flags
= flags
;
2253 while (*dirs
!= NULL
);
2257 /* When the object has the RUNPATH information we don't use any RPATHs. */
2258 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2260 /* First try the DT_RPATH of the dependent object that caused NAME
2261 to be loaded. Then that object's dependent, and on up. */
2263 struct link_map
*l
= loader
;
2266 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2267 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2272 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2273 if (loader
->l_ns
== LM_ID_BASE
)
2275 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2276 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2277 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2278 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2282 /* Try the LD_LIBRARY_PATH environment variable. */
2283 add_path (&env_path_list
, XXX_ENV
);
2285 /* Look at the RUNPATH information for this binary. */
2286 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2287 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2290 Here is where ld.so.cache gets checked, but we don't have
2291 a way to indicate that in the results for Dl_serinfo. */
2293 /* Finally, try the default path. */
2294 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2295 add_path (&rtld_search_dirs
, XXX_default
);
2298 /* Count the struct size before the string area, which we didn't
2299 know before we completed dls_cnt. */
2300 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;