1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006, 2007, 2009 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <bits/wordsize.h>
31 #include <sys/param.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
36 #include <stackinfo.h>
42 /* On some systems, no flag bits are given to specify file mapping. */
47 /* The right way to map in the shared library files is MAP_COPY, which
48 makes a virtual copy of the data at the time of the mmap call; this
49 guarantees the mapped pages will be consistent even if the file is
50 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
51 get is MAP_PRIVATE, which copies each page when it is modified; this
52 means if the file is overwritten, we may at some point get some pages
53 from the new version after starting with pages from the old version.
55 To make up for the lack and avoid the overwriting problem,
56 what Linux does have is MAP_DENYWRITE. This prevents anyone
57 from modifying the file while we have it mapped. */
60 # define MAP_COPY (MAP_PRIVATE | MAP_DENYWRITE)
62 # define MAP_COPY MAP_PRIVATE
66 /* Some systems link their relocatable objects for another base address
67 than 0. We want to know the base address for these such that we can
68 subtract this address from the segment addresses during mapping.
69 This results in a more efficient address space usage. Defaults to
70 zero for almost all systems. */
72 # define MAP_BASE_ADDR(l) 0
77 #if BYTE_ORDER == BIG_ENDIAN
78 # define byteorder ELFDATA2MSB
79 #elif BYTE_ORDER == LITTLE_ENDIAN
80 # define byteorder ELFDATA2LSB
82 # error "Unknown BYTE_ORDER " BYTE_ORDER
83 # define byteorder ELFDATANONE
86 #define STRING(x) __STRING (x)
89 /* The fd is not examined when using MAP_ANON. */
93 # define ANONFD _dl_zerofd
96 /* Handle situations where we have a preferred location in memory for
97 the shared objects. */
98 #ifdef ELF_PREFERRED_ADDRESS_DATA
99 ELF_PREFERRED_ADDRESS_DATA
;
101 #ifndef ELF_PREFERRED_ADDRESS
102 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
104 #ifndef ELF_FIXED_ADDRESS
105 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
109 int __stack_prot attribute_hidden attribute_relro
110 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
112 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
119 /* Type for the buffer we put the ELF header and hopefully the program
120 header. This buffer does not really have to be too large. In most
121 cases the program header follows the ELF header directly. If this
122 is not the case all bets are off and we can make the header
123 arbitrarily large and still won't get it read. This means the only
124 question is how large are the ELF and program header combined. The
125 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
126 bytes long. Each program header entry is again 32 and 56 bytes
127 long respectively. I.e., even with a file which has 10 program
128 header entries we only have to read 372B/624B respectively. Add to
129 this a bit of margin for program notes and reading 512B and 832B
130 for 32-bit and 64-bit files respecitvely is enough. If this
131 heuristic should really fail for some file the code in
132 `_dl_map_object_from_fd' knows how to recover. */
137 # define FILEBUF_SIZE 512
139 # define FILEBUF_SIZE 832
141 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
144 /* This is the decomposed LD_LIBRARY_PATH search path. */
145 static struct r_search_path_struct env_path_list attribute_relro
;
147 /* List of the hardware capabilities we might end up using. */
148 static const struct r_strlenpair
*capstr attribute_relro
;
149 static size_t ncapstr attribute_relro
;
150 static size_t max_capstrlen attribute_relro
;
153 /* Get the generated information about the trusted directories. */
154 #include "trusted-dirs.h"
156 static const char system_dirs
[] = SYSTEM_DIRS
;
157 static const size_t system_dirs_len
[] =
161 #define nsystem_dirs_len \
162 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
165 /* Local version of `strdup' function. */
167 local_strdup (const char *s
)
169 size_t len
= strlen (s
) + 1;
170 void *new = malloc (len
);
175 return (char *) memcpy (new, s
, len
);
180 is_dst (const char *start
, const char *name
, const char *str
,
181 int is_path
, int secure
)
184 bool is_curly
= false;
193 while (name
[len
] == str
[len
] && name
[len
] != '\0')
198 if (name
[len
] != '}')
201 /* Point again at the beginning of the name. */
203 /* Skip over closing curly brace and adjust for the --name. */
206 else if (name
[len
] != '\0' && name
[len
] != '/'
207 && (!is_path
|| name
[len
] != ':'))
210 if (__builtin_expect (secure
, 0)
211 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
212 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
220 _dl_dst_count (const char *name
, int is_path
)
222 const char *const start
= name
;
229 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
230 is $ORIGIN alone) and it must always appear first in path. */
232 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
233 INTUSE(__libc_enable_secure
))) != 0
234 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
235 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
238 name
= strchr (name
+ len
, '$');
240 while (name
!= NULL
);
247 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
250 const char *const start
= name
;
251 char *last_elem
, *wp
;
253 /* Now fill the result path. While copying over the string we keep
254 track of the start of the last path element. When we come accross
255 a DST we copy over the value or (if the value is not available)
256 leave the entire path element out. */
257 last_elem
= wp
= result
;
261 if (__builtin_expect (*name
== '$', 0))
263 const char *repl
= NULL
;
267 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
268 INTUSE(__libc_enable_secure
))) != 0)
272 repl
= _dl_get_origin ();
277 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
278 repl
= GLRO(dl_platform
);
279 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
282 if (repl
!= NULL
&& repl
!= (const char *) -1)
284 wp
= __stpcpy (wp
, repl
);
289 /* We cannot use this path element, the value of the
290 replacement is unknown. */
293 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
297 /* No DST we recognize. */
303 if (is_path
&& *name
== ':')
307 while (*name
!= '\0');
315 /* Return copy of argument with all recognized dynamic string tokens
316 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
317 might not be possible to determine the path from which the object
318 belonging to the map is loaded. In this case the path element
319 containing $ORIGIN is left out. */
321 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
323 /* We make two runs over the string. First we determine how large the
324 resulting string is and then we copy it over. Since this is now
325 frequently executed operation we are looking here not for performance
326 but rather for code size. */
331 /* Determine the number of DST elements. */
332 cnt
= DL_DST_COUNT (s
, 1);
334 /* If we do not have to replace anything simply copy the string. */
335 if (__builtin_expect (cnt
, 0) == 0)
336 return local_strdup (s
);
338 /* Determine the length of the substituted string. */
339 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
341 /* Allocate the necessary memory. */
342 result
= (char *) malloc (total
+ 1);
346 return _dl_dst_substitute (l
, s
, result
, 1);
350 /* Add `name' to the list of names for a particular shared object.
351 `name' is expected to have been allocated with malloc and will
352 be freed if the shared object already has this name.
353 Returns false if the object already had this name. */
356 add_name_to_object (struct link_map
*l
, const char *name
)
358 struct libname_list
*lnp
, *lastp
;
359 struct libname_list
*newname
;
363 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
364 if (strcmp (name
, lnp
->name
) == 0)
367 name_len
= strlen (name
) + 1;
368 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
371 /* No more memory. */
372 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
375 /* The object should have a libname set from _dl_new_object. */
376 assert (lastp
!= NULL
);
378 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
379 newname
->next
= NULL
;
380 newname
->dont_free
= 0;
381 lastp
->next
= newname
;
384 /* Standard search directories. */
385 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
387 static size_t max_dirnamelen
;
389 static struct r_search_path_elem
**
390 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
391 int check_trusted
, const char *what
, const char *where
)
396 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
398 struct r_search_path_elem
*dirp
;
399 size_t len
= strlen (cp
);
401 /* `strsep' can pass an empty string. This has to be
402 interpreted as `use the current directory'. */
405 static const char curwd
[] = "./";
409 /* Remove trailing slashes (except for "/"). */
410 while (len
> 1 && cp
[len
- 1] == '/')
413 /* Now add one if there is none so far. */
414 if (len
> 0 && cp
[len
- 1] != '/')
417 /* Make sure we don't use untrusted directories if we run SUID. */
418 if (__builtin_expect (check_trusted
, 0))
420 const char *trun
= system_dirs
;
424 /* All trusted directories must be complete names. */
427 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
429 if (len
== system_dirs_len
[idx
]
430 && memcmp (trun
, cp
, len
) == 0)
437 trun
+= system_dirs_len
[idx
] + 1;
442 /* Simply drop this directory. */
446 /* See if this directory is already known. */
447 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
448 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
453 /* It is available, see whether it's on our own list. */
455 for (cnt
= 0; cnt
< nelems
; ++cnt
)
456 if (result
[cnt
] == dirp
)
460 result
[nelems
++] = dirp
;
465 enum r_dir_status init_val
;
466 size_t where_len
= where
? strlen (where
) + 1 : 0;
468 /* It's a new directory. Create an entry and add it. */
469 dirp
= (struct r_search_path_elem
*)
470 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
471 + where_len
+ len
+ 1);
473 _dl_signal_error (ENOMEM
, NULL
, NULL
,
474 N_("cannot create cache for search path"));
476 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
477 + ncapstr
* sizeof (enum r_dir_status
));
478 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
479 dirp
->dirnamelen
= len
;
481 if (len
> max_dirnamelen
)
482 max_dirnamelen
= len
;
484 /* We have to make sure all the relative directories are
485 never ignored. The current directory might change and
486 all our saved information would be void. */
487 init_val
= cp
[0] != '/' ? existing
: unknown
;
488 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
489 dirp
->status
[cnt
] = init_val
;
492 if (__builtin_expect (where
!= NULL
, 1))
493 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
494 + (ncapstr
* sizeof (enum r_dir_status
)),
499 dirp
->next
= GL(dl_all_dirs
);
500 GL(dl_all_dirs
) = dirp
;
502 /* Put it in the result array. */
503 result
[nelems
++] = dirp
;
507 /* Terminate the array. */
508 result
[nelems
] = NULL
;
516 decompose_rpath (struct r_search_path_struct
*sps
,
517 const char *rpath
, struct link_map
*l
, const char *what
)
519 /* Make a copy we can work with. */
520 const char *where
= l
->l_name
;
523 struct r_search_path_elem
**result
;
525 /* Initialize to please the compiler. */
526 const char *errstring
= NULL
;
528 /* First see whether we must forget the RUNPATH and RPATH from this
530 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
531 && !INTUSE(__libc_enable_secure
))
533 const char *inhp
= GLRO(dl_inhibit_rpath
);
537 const char *wp
= where
;
539 while (*inhp
== *wp
&& *wp
!= '\0')
545 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
547 /* This object is on the list of objects for which the
548 RUNPATH and RPATH must not be used. */
549 sps
->dirs
= (void *) -1;
553 while (*inhp
!= '\0')
557 while (*inhp
!= '\0');
560 /* Make a writable copy. At the same time expand possible dynamic
562 copy
= expand_dynamic_string_token (l
, rpath
);
565 errstring
= N_("cannot create RUNPATH/RPATH copy");
569 /* Count the number of necessary elements in the result array. */
571 for (cp
= copy
; *cp
!= '\0'; ++cp
)
575 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
576 number of necessary entries. */
577 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
582 errstring
= N_("cannot create cache for search path");
584 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
587 fillin_rpath (copy
, result
, ":", 0, what
, where
);
589 /* Free the copied RPATH string. `fillin_rpath' make own copies if
594 /* The caller will change this value if we haven't used a real malloc. */
599 /* Make sure cached path information is stored in *SP
600 and return true if there are any paths to search there. */
602 cache_rpath (struct link_map
*l
,
603 struct r_search_path_struct
*sp
,
607 if (sp
->dirs
== (void *) -1)
610 if (sp
->dirs
!= NULL
)
613 if (l
->l_info
[tag
] == NULL
)
615 /* There is no path. */
616 sp
->dirs
= (void *) -1;
620 /* Make sure the cache information is available. */
621 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
622 + l
->l_info
[tag
]->d_un
.d_val
),
629 _dl_init_paths (const char *llp
)
633 struct r_search_path_elem
*pelem
, **aelem
;
638 /* Initialize to please the compiler. */
639 const char *errstring
= NULL
;
641 /* Fill in the information about the application's RPATH and the
642 directories addressed by the LD_LIBRARY_PATH environment variable. */
644 /* Get the capabilities. */
645 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
646 &ncapstr
, &max_capstrlen
);
648 /* First set up the rest of the default search directory entries. */
649 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
650 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
651 if (rtld_search_dirs
.dirs
== NULL
)
653 errstring
= N_("cannot create search path array");
655 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
658 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
659 + ncapstr
* sizeof (enum r_dir_status
))
660 / sizeof (struct r_search_path_elem
));
662 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
663 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
664 * round_size
* sizeof (struct r_search_path_elem
));
665 if (rtld_search_dirs
.dirs
[0] == NULL
)
667 errstring
= N_("cannot create cache for search path");
671 rtld_search_dirs
.malloced
= 0;
672 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
682 pelem
->what
= "system search path";
685 pelem
->dirname
= strp
;
686 pelem
->dirnamelen
= system_dirs_len
[idx
];
687 strp
+= system_dirs_len
[idx
] + 1;
689 /* System paths must be absolute. */
690 assert (pelem
->dirname
[0] == '/');
691 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
692 pelem
->status
[cnt
] = unknown
;
694 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
698 while (idx
< nsystem_dirs_len
);
700 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
704 /* This points to the map of the main object. */
705 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
708 assert (l
->l_type
!= lt_loaded
);
710 if (l
->l_info
[DT_RUNPATH
])
712 /* Allocate room for the search path and fill in information
714 decompose_rpath (&l
->l_runpath_dirs
,
715 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
716 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
719 /* The RPATH is ignored. */
720 l
->l_rpath_dirs
.dirs
= (void *) -1;
724 l
->l_runpath_dirs
.dirs
= (void *) -1;
726 if (l
->l_info
[DT_RPATH
])
728 /* Allocate room for the search path and fill in information
730 decompose_rpath (&l
->l_rpath_dirs
,
731 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
732 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
734 l
->l_rpath_dirs
.malloced
= 0;
737 l
->l_rpath_dirs
.dirs
= (void *) -1;
742 if (llp
!= NULL
&& *llp
!= '\0')
745 const char *cp
= llp
;
750 size_t cnt
= DL_DST_COUNT (llp
, 1);
751 if (__builtin_expect (cnt
== 0, 1))
752 llp_tmp
= strdupa (llp
);
755 /* Determine the length of the substituted string. */
756 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
758 /* Allocate the necessary memory. */
759 llp_tmp
= (char *) alloca (total
+ 1);
760 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
763 llp_tmp
= strdupa (llp
);
766 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
771 if (*cp
== ':' || *cp
== ';')
776 env_path_list
.dirs
= (struct r_search_path_elem
**)
777 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
778 if (env_path_list
.dirs
== NULL
)
780 errstring
= N_("cannot create cache for search path");
784 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
785 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
788 if (env_path_list
.dirs
[0] == NULL
)
790 free (env_path_list
.dirs
);
791 env_path_list
.dirs
= (void *) -1;
794 env_path_list
.malloced
= 0;
797 env_path_list
.dirs
= (void *) -1;
799 /* Remember the last search directory added at startup. */
800 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
805 __attribute__ ((noreturn
, noinline
))
806 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
807 const char *msg
, struct r_debug
*r
)
809 /* The file might already be closed. */
814 /* Remove the stillborn object from the list and free it. */
815 assert (l
->l_next
== NULL
);
816 if (l
->l_prev
== NULL
)
817 /* No other module loaded. This happens only in the static library,
818 or in rtld under --verify. */
819 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
821 l
->l_prev
->l_next
= NULL
;
822 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
829 r
->r_state
= RT_CONSISTENT
;
833 _dl_signal_error (code
, name
, NULL
, msg
);
837 /* Map in the shared object NAME, actually located in REALNAME, and already
840 #ifndef EXTERNAL_MAP_FROM_FD
844 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
845 char *realname
, struct link_map
*loader
, int l_type
,
846 int mode
, void **stack_endp
, Lmid_t nsid
)
848 struct link_map
*l
= NULL
;
849 const ElfW(Ehdr
) *header
;
850 const ElfW(Phdr
) *phdr
;
851 const ElfW(Phdr
) *ph
;
855 /* Initialize to keep the compiler happy. */
856 const char *errstring
= NULL
;
858 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
859 bool make_consistent
= false;
861 /* Get file information. */
862 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
864 errstring
= N_("cannot stat shared object");
868 lose (errval
, fd
, name
, realname
, l
, errstring
,
869 make_consistent
? r
: NULL
);
872 /* Look again to see if the real name matched another already loaded. */
873 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
874 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
876 /* The object is already loaded.
877 Just bump its reference count and return it. */
880 /* If the name is not in the list of names for this object add
883 add_name_to_object (l
, name
);
889 /* When loading into a namespace other than the base one we must
890 avoid loading ld.so since there can only be one copy. Ever. */
891 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
892 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
893 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
894 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
896 /* This is indeed ld.so. Create a new link_map which refers to
897 the real one for almost everything. */
898 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
902 /* Refer to the real descriptor. */
903 l
->l_real
= &GL(dl_rtld_map
);
905 /* No need to bump the refcount of the real object, ld.so will
906 never be unloaded. */
913 if (mode
& RTLD_NOLOAD
)
914 /* We are not supposed to load the object unless it is already
915 loaded. So return now. */
918 /* Print debugging message. */
919 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
920 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
922 /* This is the ELF header. We read it in `open_verify'. */
923 header
= (void *) fbp
->buf
;
927 if (_dl_zerofd
== -1)
929 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
930 if (_dl_zerofd
== -1)
933 _dl_signal_error (errno
, NULL
, NULL
,
934 N_("cannot open zero fill device"));
939 /* Signal that we are going to add new objects. */
940 if (r
->r_state
== RT_CONSISTENT
)
943 /* Auditing checkpoint: we are going to add new objects. */
944 if ((mode
& __RTLD_AUDIT
) == 0
945 && __builtin_expect (GLRO(dl_naudit
) > 0, 0))
947 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
948 /* Do not call the functions for any auditing object. */
949 if (head
->l_auditing
== 0)
951 struct audit_ifaces
*afct
= GLRO(dl_audit
);
952 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
954 if (afct
->activity
!= NULL
)
955 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
963 /* Notify the debugger we have added some objects. We need to
964 call _dl_debug_initialize in a static program in case dynamic
965 linking has not been used before. */
968 make_consistent
= true;
971 assert (r
->r_state
== RT_ADD
);
973 /* Enter the new object in the list of loaded objects. */
974 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
975 if (__builtin_expect (l
== NULL
, 0))
980 errstring
= N_("cannot create shared object descriptor");
981 goto call_lose_errno
;
984 /* Extract the remaining details we need from the ELF header
985 and then read in the program header table. */
986 l
->l_entry
= header
->e_entry
;
987 type
= header
->e_type
;
988 l
->l_phnum
= header
->e_phnum
;
990 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
991 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
992 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
995 phdr
= alloca (maplength
);
996 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
997 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
999 errstring
= N_("cannot read file data");
1000 goto call_lose_errno
;
1004 /* Presumed absent PT_GNU_STACK. */
1005 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
1008 /* Scan the program header table, collecting its load commands. */
1011 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1014 } loadcmds
[l
->l_phnum
], *c
;
1015 size_t nloadcmds
= 0;
1016 bool has_holes
= false;
1018 /* The struct is initialized to zero so this is not necessary:
1022 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1025 /* These entries tell us where to find things once the file's
1026 segments are mapped in. We record the addresses it says
1027 verbatim, and later correct for the run-time load address. */
1029 l
->l_ld
= (void *) ph
->p_vaddr
;
1030 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1034 l
->l_phdr
= (void *) ph
->p_vaddr
;
1038 /* A load command tells us to map in part of the file.
1039 We record the load commands and process them all later. */
1040 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1043 errstring
= N_("ELF load command alignment not page-aligned");
1046 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1047 & (ph
->p_align
- 1)) != 0, 0))
1050 = N_("ELF load command address/offset not properly aligned");
1054 c
= &loadcmds
[nloadcmds
++];
1055 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1056 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1057 & ~(GLRO(dl_pagesize
) - 1));
1058 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1059 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1060 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1062 /* Determine whether there is a gap between the last segment
1064 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1067 /* Optimize a common case. */
1068 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1069 c
->prot
= (PF_TO_PROT
1070 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1073 if (ph
->p_flags
& PF_R
)
1074 c
->prot
|= PROT_READ
;
1075 if (ph
->p_flags
& PF_W
)
1076 c
->prot
|= PROT_WRITE
;
1077 if (ph
->p_flags
& PF_X
)
1078 c
->prot
|= PROT_EXEC
;
1083 if (ph
->p_memsz
== 0)
1084 /* Nothing to do for an empty segment. */
1087 l
->l_tls_blocksize
= ph
->p_memsz
;
1088 l
->l_tls_align
= ph
->p_align
;
1089 if (ph
->p_align
== 0)
1090 l
->l_tls_firstbyte_offset
= 0;
1092 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1093 l
->l_tls_initimage_size
= ph
->p_filesz
;
1094 /* Since we don't know the load address yet only store the
1095 offset. We will adjust it later. */
1096 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1098 /* If not loading the initial set of shared libraries,
1099 check whether we should permit loading a TLS segment. */
1100 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1101 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1102 not set up TLS data structures, so don't use them now. */
1103 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1105 /* Assign the next available module ID. */
1106 l
->l_tls_modid
= _dl_next_tls_modid ();
1111 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1112 /* We are loading the executable itself when the dynamic linker
1113 was executed directly. The setup will happen later. */
1116 /* In a static binary there is no way to tell if we dynamically
1117 loaded libpthread. */
1118 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1121 /* We have not yet loaded libpthread.
1122 We can do the TLS setup right now! */
1126 /* The first call allocates TLS bookkeeping data structures.
1127 Then we allocate the TCB for the initial thread. */
1128 if (__builtin_expect (_dl_tls_setup (), 0)
1129 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1134 cannot allocate TLS data structures for initial thread");
1138 /* Now we install the TCB in the thread register. */
1139 errstring
= TLS_INIT_TP (tcb
, 0);
1140 if (__builtin_expect (errstring
== NULL
, 1))
1142 /* Now we are all good. */
1143 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1147 /* The kernel is too old or somesuch. */
1149 _dl_deallocate_tls (tcb
, 1);
1153 /* Uh-oh, the binary expects TLS support but we cannot
1156 errstring
= N_("cannot handle TLS data");
1161 stack_flags
= ph
->p_flags
;
1165 l
->l_relro_addr
= ph
->p_vaddr
;
1166 l
->l_relro_size
= ph
->p_memsz
;
1170 if (__builtin_expect (nloadcmds
== 0, 0))
1172 /* This only happens for a bogus object that will be caught with
1173 another error below. But we don't want to go through the
1174 calculations below using NLOADCMDS - 1. */
1175 errstring
= N_("object file has no loadable segments");
1179 /* Now process the load commands and map segments into memory. */
1182 /* Length of the sections to be loaded. */
1183 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1185 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1187 /* This is a position-independent shared object. We can let the
1188 kernel map it anywhere it likes, but we must have space for all
1189 the segments in their specified positions relative to the first.
1190 So we map the first segment without MAP_FIXED, but with its
1191 extent increased to cover all the segments. Then we remove
1192 access from excess portion, and there is known sufficient space
1193 there to remap from the later segments.
1195 As a refinement, sometimes we have an address that we would
1196 prefer to map such objects at; but this is only a preference,
1197 the OS can do whatever it likes. */
1199 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1200 c
->mapstart
& GLRO(dl_use_load_bias
))
1201 - MAP_BASE_ADDR (l
));
1203 /* Remember which part of the address space this object uses. */
1204 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1208 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1211 errstring
= N_("failed to map segment from shared object");
1212 goto call_lose_errno
;
1215 l
->l_map_end
= l
->l_map_start
+ maplength
;
1216 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1219 /* Change protection on the excess portion to disallow all access;
1220 the portions we do not remap later will be inaccessible as if
1221 unallocated. Then jump into the normal segment-mapping loop to
1222 handle the portion of the segment past the end of the file
1224 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1225 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1228 l
->l_contiguous
= 1;
1233 /* This object is loaded at a fixed address. This must never
1234 happen for objects loaded with dlopen(). */
1235 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1237 errstring
= N_("cannot dynamically load executable");
1241 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1243 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1246 /* Remember which part of the address space this object uses. */
1247 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1248 l
->l_map_end
= l
->l_map_start
+ maplength
;
1249 l
->l_contiguous
= !has_holes
;
1251 while (c
< &loadcmds
[nloadcmds
])
1253 if (c
->mapend
> c
->mapstart
1254 /* Map the segment contents from the file. */
1255 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1256 c
->mapend
- c
->mapstart
, c
->prot
,
1257 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1263 if (c
->prot
& PROT_EXEC
)
1264 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1267 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1268 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1269 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1270 /* Found the program header in this segment. */
1271 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1273 if (c
->allocend
> c
->dataend
)
1275 /* Extra zero pages should appear at the end of this segment,
1276 after the data mapped from the file. */
1277 ElfW(Addr
) zero
, zeroend
, zeropage
;
1279 zero
= l
->l_addr
+ c
->dataend
;
1280 zeroend
= l
->l_addr
+ c
->allocend
;
1281 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1282 & ~(GLRO(dl_pagesize
) - 1));
1284 if (zeroend
< zeropage
)
1285 /* All the extra data is in the last page of the segment.
1286 We can just zero it. */
1289 if (zeropage
> zero
)
1291 /* Zero the final part of the last page of the segment. */
1292 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1295 if (__mprotect ((caddr_t
) (zero
1296 & ~(GLRO(dl_pagesize
) - 1)),
1297 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1299 errstring
= N_("cannot change memory protections");
1300 goto call_lose_errno
;
1303 memset ((void *) zero
, '\0', zeropage
- zero
);
1304 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1305 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1306 GLRO(dl_pagesize
), c
->prot
);
1309 if (zeroend
> zeropage
)
1311 /* Map the remaining zero pages in from the zero fill FD. */
1313 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1314 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1316 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1318 errstring
= N_("cannot map zero-fill pages");
1319 goto call_lose_errno
;
1330 if (__builtin_expect (type
== ET_DYN
, 0))
1332 errstring
= N_("object file has no dynamic section");
1337 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1339 elf_get_dynamic_info (l
, NULL
);
1341 /* Make sure we are not dlopen'ing an object that has the
1342 DF_1_NOOPEN flag set. */
1343 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1344 && (mode
& __RTLD_DLOPEN
))
1346 /* We are not supposed to load this object. Free all resources. */
1347 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1349 if (!l
->l_libname
->dont_free
)
1350 free (l
->l_libname
);
1352 if (l
->l_phdr_allocated
)
1353 free ((void *) l
->l_phdr
);
1355 errstring
= N_("shared object cannot be dlopen()ed");
1359 if (l
->l_phdr
== NULL
)
1361 /* The program header is not contained in any of the segments.
1362 We have to allocate memory ourself and copy it over from out
1364 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1365 * sizeof (ElfW(Phdr
)));
1368 errstring
= N_("cannot allocate memory for program header");
1369 goto call_lose_errno
;
1372 l
->l_phdr
= memcpy (newp
, phdr
,
1373 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1374 l
->l_phdr_allocated
= 1;
1377 /* Adjust the PT_PHDR value by the runtime load address. */
1378 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1380 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1382 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1385 errstring
= N_("invalid caller");
1389 /* The stack is presently not executable, but this module
1390 requires that it be executable. We must change the
1391 protection of the variable which contains the flags used in
1392 the mprotect calls. */
1394 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1396 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1397 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1399 struct link_map
*const m
= &GL(dl_rtld_map
);
1400 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1402 & -GLRO(dl_pagesize
));
1403 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1405 /* The variable lies in the region protected by RELRO. */
1406 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1407 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1408 __mprotect ((void *) p
, s
, PROT_READ
);
1411 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1415 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1417 #ifdef check_consistency
1418 check_consistency ();
1421 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1425 cannot enable executable stack as shared object requires");
1430 /* Adjust the address of the TLS initialization image. */
1431 if (l
->l_tls_initimage
!= NULL
)
1432 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1434 /* We are done mapping in the file. We no longer need the descriptor. */
1435 if (__builtin_expect (__close (fd
) != 0, 0))
1437 errstring
= N_("cannot close file descriptor");
1438 goto call_lose_errno
;
1440 /* Signal that we closed the file. */
1443 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1444 l
->l_type
= lt_executable
;
1446 l
->l_entry
+= l
->l_addr
;
1448 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1449 _dl_debug_printf ("\
1450 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1451 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1452 (int) sizeof (void *) * 2,
1453 (unsigned long int) l
->l_ld
,
1454 (int) sizeof (void *) * 2,
1455 (unsigned long int) l
->l_addr
,
1456 (int) sizeof (void *) * 2, maplength
,
1457 (int) sizeof (void *) * 2,
1458 (unsigned long int) l
->l_entry
,
1459 (int) sizeof (void *) * 2,
1460 (unsigned long int) l
->l_phdr
,
1461 (int) sizeof (void *) * 2, l
->l_phnum
);
1463 /* Set up the symbol hash table. */
1466 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1467 have to do this for the main map. */
1468 if ((mode
& RTLD_DEEPBIND
) == 0
1469 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1470 && &l
->l_searchlist
!= l
->l_scope
[0])
1472 /* Create an appropriate searchlist. It contains only this map.
1473 This is the definition of DT_SYMBOLIC in SysVr4. */
1474 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1475 l
->l_symbolic_searchlist
.r_nlist
= 1;
1477 /* Now move the existing entries one back. */
1478 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1479 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1481 /* Now add the new entry. */
1482 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1485 /* Remember whether this object must be initialized first. */
1486 if (l
->l_flags_1
& DF_1_INITFIRST
)
1487 GL(dl_initfirst
) = l
;
1489 /* Finally the file information. */
1490 l
->l_dev
= st
.st_dev
;
1491 l
->l_ino
= st
.st_ino
;
1493 /* When we profile the SONAME might be needed for something else but
1494 loading. Add it right away. */
1495 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1496 && l
->l_info
[DT_SONAME
] != NULL
)
1497 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1498 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1501 /* Auditing checkpoint: we have a new object. */
1502 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1503 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1505 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1506 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1508 if (afct
->objopen
!= NULL
)
1510 l
->l_audit
[cnt
].bindflags
1511 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1513 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1524 /* Print search path. */
1526 print_search_path (struct r_search_path_elem
**list
,
1527 const char *what
, const char *name
)
1529 char buf
[max_dirnamelen
+ max_capstrlen
];
1532 _dl_debug_printf (" search path=");
1534 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1536 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1539 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1540 if ((*list
)->status
[cnt
] != nonexisting
)
1542 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1543 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1548 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1556 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1557 name
[0] ? name
: rtld_progname
);
1559 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1562 /* Open a file and verify it is an ELF file for this architecture. We
1563 ignore only ELF files for other architectures. Non-ELF files and
1564 ELF files with different header information cause fatal errors since
1565 this could mean there is something wrong in the installation and the
1566 user might want to know about this. */
1568 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1569 int whatcode
, bool *found_other_class
, bool free_name
)
1571 /* This is the expected ELF header. */
1572 #define ELF32_CLASS ELFCLASS32
1573 #define ELF64_CLASS ELFCLASS64
1574 #ifndef VALID_ELF_HEADER
1575 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1576 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1577 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1578 #elif defined MORE_ELF_HEADER_DATA
1579 MORE_ELF_HEADER_DATA
;
1581 static const unsigned char expected
[EI_PAD
] =
1583 [EI_MAG0
] = ELFMAG0
,
1584 [EI_MAG1
] = ELFMAG1
,
1585 [EI_MAG2
] = ELFMAG2
,
1586 [EI_MAG3
] = ELFMAG3
,
1587 [EI_CLASS
] = ELFW(CLASS
),
1588 [EI_DATA
] = byteorder
,
1589 [EI_VERSION
] = EV_CURRENT
,
1590 [EI_OSABI
] = ELFOSABI_SYSV
,
1595 ElfW(Word
) vendorlen
;
1599 } expected_note
= { 4, 16, 1, "GNU" };
1600 /* Initialize it to make the compiler happy. */
1601 const char *errstring
= NULL
;
1605 /* Give the auditing libraries a chance. */
1606 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1607 && loader
->l_auditing
== 0)
1609 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1610 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1612 if (afct
->objsearch
!= NULL
)
1614 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1617 /* Ignore the path. */
1626 /* Open the file. We always open files read-only. */
1627 int fd
= __open (name
, O_RDONLY
);
1631 ElfW(Phdr
) *phdr
, *ph
;
1632 ElfW(Word
) *abi_note
;
1633 unsigned int osversion
;
1636 /* We successfully openened the file. Now verify it is a file
1639 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1641 /* This is where the ELF header is loaded. */
1642 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1643 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1645 /* Now run the tests. */
1646 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1649 errstring
= (errval
== 0
1650 ? N_("file too short") : N_("cannot read file data"));
1654 char *realname
= (char *) name
;
1655 name
= strdupa (realname
);
1658 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1661 /* See whether the ELF header is what we expect. */
1662 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1665 /* Something is wrong. */
1666 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1667 #if BYTE_ORDER == LITTLE_ENDIAN
1668 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1669 (ELFMAG1
<< (EI_MAG1
* 8)) |
1670 (ELFMAG2
<< (EI_MAG2
* 8)) |
1671 (ELFMAG3
<< (EI_MAG3
* 8)))
1673 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1674 (ELFMAG1
<< (EI_MAG2
* 8)) |
1675 (ELFMAG2
<< (EI_MAG1
* 8)) |
1676 (ELFMAG3
<< (EI_MAG0
* 8)))
1679 errstring
= N_("invalid ELF header");
1680 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1682 /* This is not a fatal error. On architectures where
1683 32-bit and 64-bit binaries can be run this might
1685 *found_other_class
= true;
1688 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1690 if (BYTE_ORDER
== BIG_ENDIAN
)
1691 errstring
= N_("ELF file data encoding not big-endian");
1693 errstring
= N_("ELF file data encoding not little-endian");
1695 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1697 = N_("ELF file version ident does not match current one");
1698 /* XXX We should be able so set system specific versions which are
1700 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1701 errstring
= N_("ELF file OS ABI invalid");
1702 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1703 errstring
= N_("ELF file ABI version invalid");
1705 /* Otherwise we don't know what went wrong. */
1706 errstring
= N_("internal error");
1711 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1713 errstring
= N_("ELF file version does not match current one");
1716 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1718 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1719 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1721 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1724 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1725 != sizeof (ElfW(Phdr
)))
1727 errstring
= N_("ELF file's phentsize not the expected size");
1731 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1732 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1733 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1736 phdr
= alloca (maplength
);
1737 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1738 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1742 errstring
= N_("cannot read file data");
1747 /* Check .note.ABI-tag if present. */
1748 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1749 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1751 ElfW(Addr
) size
= ph
->p_filesz
;
1753 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1754 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1757 abi_note
= alloca (size
);
1758 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1759 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1763 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1765 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1766 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1767 + ROUND (abi_note
[0])
1768 + ROUND (abi_note
[1]);
1770 if (size
- 32 < note_size
)
1776 abi_note
= (void *) abi_note
+ note_size
;
1782 osversion
= (abi_note
[5] & 0xff) * 65536
1783 + (abi_note
[6] & 0xff) * 256
1784 + (abi_note
[7] & 0xff);
1785 if (abi_note
[4] != __ABI_TAG_OS
1786 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1790 __set_errno (ENOENT
);
1801 /* Try to open NAME in one of the directories in *DIRSP.
1802 Return the fd, or -1. If successful, fill in *REALNAME
1803 with the malloc'd full directory name. If it turns out
1804 that none of the directories in *DIRSP exists, *DIRSP is
1805 replaced with (void *) -1, and the old value is free()d
1806 if MAY_FREE_DIRS is true. */
1809 open_path (const char *name
, size_t namelen
, int preloaded
,
1810 struct r_search_path_struct
*sps
, char **realname
,
1811 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1812 bool *found_other_class
)
1814 struct r_search_path_elem
**dirs
= sps
->dirs
;
1817 const char *current_what
= NULL
;
1820 if (__builtin_expect (dirs
== NULL
, 0))
1821 /* We're called before _dl_init_paths when loading the main executable
1822 given on the command line when rtld is run directly. */
1825 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1828 struct r_search_path_elem
*this_dir
= *dirs
;
1835 /* If we are debugging the search for libraries print the path
1836 now if it hasn't happened now. */
1837 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1838 && current_what
!= this_dir
->what
)
1840 current_what
= this_dir
->what
;
1841 print_search_path (dirs
, current_what
, this_dir
->where
);
1844 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1845 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1847 /* Skip this directory if we know it does not exist. */
1848 if (this_dir
->status
[cnt
] == nonexisting
)
1852 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1857 /* Print name we try if this is wanted. */
1858 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1859 _dl_debug_printf (" trying file=%s\n", buf
);
1861 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1863 if (this_dir
->status
[cnt
] == unknown
)
1866 this_dir
->status
[cnt
] = existing
;
1867 /* Do not update the directory information when loading
1868 auditing code. We must try to disturb the program as
1869 little as possible. */
1870 else if (loader
== NULL
1871 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1873 /* We failed to open machine dependent library. Let's
1874 test whether there is any directory at all. */
1877 buf
[buflen
- namelen
- 1] = '\0';
1879 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1880 || ! S_ISDIR (st
.st_mode
))
1881 /* The directory does not exist or it is no directory. */
1882 this_dir
->status
[cnt
] = nonexisting
;
1884 this_dir
->status
[cnt
] = existing
;
1888 /* Remember whether we found any existing directory. */
1889 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1891 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1892 && INTUSE(__libc_enable_secure
))
1894 /* This is an extra security effort to make sure nobody can
1895 preload broken shared objects which are in the trusted
1896 directories and so exploit the bugs. */
1899 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1900 || (st
.st_mode
& S_ISUID
) == 0)
1902 /* The shared object cannot be tested for being SUID
1903 or this bit is not set. In this case we must not
1907 /* We simply ignore the file, signal this by setting
1908 the error value which would have been set by `open'. */
1916 *realname
= (char *) malloc (buflen
);
1917 if (*realname
!= NULL
)
1919 memcpy (*realname
, buf
, buflen
);
1924 /* No memory for the name, we certainly won't be able
1925 to load and link it. */
1930 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1931 /* The file exists and is readable, but something went wrong. */
1934 /* Remember whether we found anything. */
1937 while (*++dirs
!= NULL
);
1939 /* Remove the whole path if none of the directories exists. */
1940 if (__builtin_expect (! any
, 0))
1942 /* Paths which were allocated using the minimal malloc() in ld.so
1943 must not be freed using the general free() in libc. */
1947 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1949 if (sps
!= &rtld_search_dirs
)
1950 sps
->dirs
= (void *) -1;
1956 /* Map in the shared object file NAME. */
1960 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1961 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1970 assert (nsid
< DL_NNS
);
1972 /* Look for this name among those already loaded. */
1973 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1975 /* If the requested name matches the soname of a loaded object,
1976 use that object. Elide this check for names that have not
1978 if (__builtin_expect (l
->l_faked
, 0) != 0
1979 || __builtin_expect (l
->l_removed
, 0) != 0)
1981 if (!_dl_name_match_p (name
, l
))
1985 if (__builtin_expect (l
->l_soname_added
, 1)
1986 || l
->l_info
[DT_SONAME
] == NULL
)
1989 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1990 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1991 if (strcmp (name
, soname
) != 0)
1994 /* We have a match on a new name -- cache it. */
1995 add_name_to_object (l
, soname
);
1996 l
->l_soname_added
= 1;
1999 /* We have a match. */
2003 /* Display information if we are debugging. */
2004 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2006 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2008 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2011 /* Give the auditing libraries a chance to change the name before we
2013 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2014 && (loader
== NULL
|| loader
->l_auditing
== 0))
2016 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2017 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2019 if (afct
->objsearch
!= NULL
)
2021 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2025 /* Do not try anything further. */
2036 /* Will be true if we found a DSO which is of the other ELF class. */
2037 bool found_other_class
= false;
2039 if (strchr (name
, '/') == NULL
)
2041 /* Search for NAME in several places. */
2043 size_t namelen
= strlen (name
) + 1;
2045 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2046 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2050 /* When the object has the RUNPATH information we don't use any
2052 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2054 /* This is the executable's map (if there is one). Make sure that
2055 we do not look at it twice. */
2056 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2057 bool did_main_map
= false;
2059 /* First try the DT_RPATH of the dependent object that caused NAME
2060 to be loaded. Then that object's dependent, and on up. */
2061 for (l
= loader
; l
; l
= l
->l_loader
)
2062 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2064 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2065 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2066 &found_other_class
);
2070 did_main_map
|= l
== main_map
;
2073 /* If dynamically linked, try the DT_RPATH of the executable
2074 itself. NB: we do this for lookups in any namespace. */
2075 if (fd
== -1 && !did_main_map
2076 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2077 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2079 fd
= open_path (name
, namelen
, preloaded
, &main_map
->l_rpath_dirs
,
2080 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2081 &found_other_class
);
2084 /* Try the LD_LIBRARY_PATH environment variable. */
2085 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2086 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2088 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2089 LA_SER_LIBPATH
, &found_other_class
);
2091 /* Look at the RUNPATH information for this binary. */
2092 if (fd
== -1 && loader
!= NULL
2093 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2094 DT_RUNPATH
, "RUNPATH"))
2095 fd
= open_path (name
, namelen
, preloaded
,
2096 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2097 LA_SER_RUNPATH
, &found_other_class
);
2100 && (__builtin_expect (! preloaded
, 1)
2101 || ! INTUSE(__libc_enable_secure
)))
2103 /* Check the list of libraries in the file /etc/ld.so.cache,
2104 for compatibility with Linux's ldconfig program. */
2105 const char *cached
= _dl_load_cache_lookup (name
);
2110 // XXX Correct to unconditionally default to namespace 0?
2111 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2116 /* If the loader has the DF_1_NODEFLIB flag set we must not
2117 use a cache entry from any of these directories. */
2120 /* 'l' is always != NULL for dynamically linked objects. */
2123 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2125 const char *dirp
= system_dirs
;
2126 unsigned int cnt
= 0;
2130 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2132 /* The prefix matches. Don't use the entry. */
2137 dirp
+= system_dirs_len
[cnt
] + 1;
2140 while (cnt
< nsystem_dirs_len
);
2145 fd
= open_verify (cached
,
2146 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2147 LA_SER_CONFIG
, &found_other_class
, false);
2148 if (__builtin_expect (fd
!= -1, 1))
2150 realname
= local_strdup (cached
);
2151 if (realname
== NULL
)
2161 /* Finally, try the default path. */
2163 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2164 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2165 && rtld_search_dirs
.dirs
!= (void *) -1)
2166 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2167 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2169 /* Add another newline when we are tracing the library loading. */
2170 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2171 _dl_debug_printf ("\n");
2175 /* The path may contain dynamic string tokens. */
2177 ? expand_dynamic_string_token (loader
, name
)
2178 : local_strdup (name
));
2179 if (realname
== NULL
)
2183 fd
= open_verify (realname
, &fb
,
2184 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2185 &found_other_class
, true);
2186 if (__builtin_expect (fd
, 0) == -1)
2194 /* In case the LOADER information has only been provided to get to
2195 the appropriate RUNPATH/RPATH information we do not need it
2197 if (mode
& __RTLD_CALLMAP
)
2200 if (__builtin_expect (fd
, 0) == -1)
2203 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2205 /* We haven't found an appropriate library. But since we
2206 are only interested in the list of libraries this isn't
2207 so severe. Fake an entry with all the information we
2209 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2211 /* Enter the new object in the list of loaded objects. */
2212 if ((name_copy
= local_strdup (name
)) == NULL
2213 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2214 mode
, nsid
)) == NULL
)
2217 _dl_signal_error (ENOMEM
, name
, NULL
,
2218 N_("cannot create shared object descriptor"));
2220 /* Signal that this is a faked entry. */
2222 /* Since the descriptor is initialized with zero we do not
2224 l->l_reserved = 0; */
2225 l
->l_buckets
= &dummy_bucket
;
2231 else if (found_other_class
)
2232 _dl_signal_error (0, name
, NULL
,
2233 ELFW(CLASS
) == ELFCLASS32
2234 ? N_("wrong ELF class: ELFCLASS64")
2235 : N_("wrong ELF class: ELFCLASS32"));
2237 _dl_signal_error (errno
, name
, NULL
,
2238 N_("cannot open shared object file"));
2241 void *stack_end
= __libc_stack_end
;
2242 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2249 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2257 unsigned int idx
= 0;
2258 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2259 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2260 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2262 if (sps
->dirs
!= (void *) -1)
2264 struct r_search_path_elem
**dirs
= sps
->dirs
;
2267 const struct r_search_path_elem
*const r
= *dirs
++;
2271 si
->dls_size
+= MAX (2, r
->dirnamelen
);
2275 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2276 sp
->dls_name
= allocptr
;
2277 if (r
->dirnamelen
< 2)
2278 *allocptr
++ = r
->dirnamelen
? '/' : '.';
2280 allocptr
= __mempcpy (allocptr
,
2281 r
->dirname
, r
->dirnamelen
- 1);
2283 sp
->dls_flags
= flags
;
2286 while (*dirs
!= NULL
);
2290 /* When the object has the RUNPATH information we don't use any RPATHs. */
2291 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2293 /* First try the DT_RPATH of the dependent object that caused NAME
2294 to be loaded. Then that object's dependent, and on up. */
2296 struct link_map
*l
= loader
;
2299 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2300 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2305 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2306 if (loader
->l_ns
== LM_ID_BASE
)
2308 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2309 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2310 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2311 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2315 /* Try the LD_LIBRARY_PATH environment variable. */
2316 add_path (&env_path_list
, XXX_ENV
);
2318 /* Look at the RUNPATH information for this binary. */
2319 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2320 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2323 Here is where ld.so.cache gets checked, but we don't have
2324 a way to indicate that in the results for Dl_serinfo. */
2326 /* Finally, try the default path. */
2327 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2328 add_path (&rtld_search_dirs
, XXX_default
);
2331 /* Count the struct size before the string area, which we didn't
2332 know before we completed dls_cnt. */
2333 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;