1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006, 2007 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <bits/wordsize.h>
31 #include <sys/param.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
36 #include <stackinfo.h>
42 /* On some systems, no flag bits are given to specify file mapping. */
47 /* The right way to map in the shared library files is MAP_COPY, which
48 makes a virtual copy of the data at the time of the mmap call; this
49 guarantees the mapped pages will be consistent even if the file is
50 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
51 get is MAP_PRIVATE, which copies each page when it is modified; this
52 means if the file is overwritten, we may at some point get some pages
53 from the new version after starting with pages from the old version.
55 To make up for the lack and avoid the overwriting problem,
56 what Linux does have is MAP_DENYWRITE. This prevents anyone
57 from modifying the file while we have it mapped. */
60 # define MAP_COPY (MAP_PRIVATE | MAP_DENYWRITE)
62 # define MAP_COPY MAP_PRIVATE
66 /* Some systems link their relocatable objects for another base address
67 than 0. We want to know the base address for these such that we can
68 subtract this address from the segment addresses during mapping.
69 This results in a more efficient address space usage. Defaults to
70 zero for almost all systems. */
72 # define MAP_BASE_ADDR(l) 0
77 #if BYTE_ORDER == BIG_ENDIAN
78 # define byteorder ELFDATA2MSB
79 #elif BYTE_ORDER == LITTLE_ENDIAN
80 # define byteorder ELFDATA2LSB
82 # error "Unknown BYTE_ORDER " BYTE_ORDER
83 # define byteorder ELFDATANONE
86 #define STRING(x) __STRING (x)
89 /* The fd is not examined when using MAP_ANON. */
93 # define ANONFD _dl_zerofd
96 /* Handle situations where we have a preferred location in memory for
97 the shared objects. */
98 #ifdef ELF_PREFERRED_ADDRESS_DATA
99 ELF_PREFERRED_ADDRESS_DATA
;
101 #ifndef ELF_PREFERRED_ADDRESS
102 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
104 #ifndef ELF_FIXED_ADDRESS
105 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
109 int __stack_prot attribute_hidden attribute_relro
110 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
112 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
119 /* Type for the buffer we put the ELF header and hopefully the program
120 header. This buffer does not really have to be too large. In most
121 cases the program header follows the ELF header directly. If this
122 is not the case all bets are off and we can make the header
123 arbitrarily large and still won't get it read. This means the only
124 question is how large are the ELF and program header combined. The
125 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
126 bytes long. Each program header entry is again 32 and 56 bytes
127 long respectively. I.e., even with a file which has 10 program
128 header entries we only have to read 372B/624B respectively. Add to
129 this a bit of margin for program notes and reading 512B and 832B
130 for 32-bit and 64-bit files respecitvely is enough. If this
131 heuristic should really fail for some file the code in
132 `_dl_map_object_from_fd' knows how to recover. */
137 # define FILEBUF_SIZE 512
139 # define FILEBUF_SIZE 832
141 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
144 /* This is the decomposed LD_LIBRARY_PATH search path. */
145 static struct r_search_path_struct env_path_list attribute_relro
;
147 /* List of the hardware capabilities we might end up using. */
148 static const struct r_strlenpair
*capstr attribute_relro
;
149 static size_t ncapstr attribute_relro
;
150 static size_t max_capstrlen attribute_relro
;
153 /* Get the generated information about the trusted directories. */
154 #include "trusted-dirs.h"
156 static const char system_dirs
[] = SYSTEM_DIRS
;
157 static const size_t system_dirs_len
[] =
161 #define nsystem_dirs_len \
162 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
165 /* Local version of `strdup' function. */
167 local_strdup (const char *s
)
169 size_t len
= strlen (s
) + 1;
170 void *new = malloc (len
);
175 return (char *) memcpy (new, s
, len
);
180 is_dst (const char *start
, const char *name
, const char *str
,
181 int is_path
, int secure
)
184 bool is_curly
= false;
193 while (name
[len
] == str
[len
] && name
[len
] != '\0')
198 if (name
[len
] != '}')
201 /* Point again at the beginning of the name. */
203 /* Skip over closing curly brace and adjust for the --name. */
206 else if (name
[len
] != '\0' && name
[len
] != '/'
207 && (!is_path
|| name
[len
] != ':'))
210 if (__builtin_expect (secure
, 0)
211 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
212 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
220 _dl_dst_count (const char *name
, int is_path
)
222 const char *const start
= name
;
229 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
230 is $ORIGIN alone) and it must always appear first in path. */
232 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
233 INTUSE(__libc_enable_secure
))) != 0
234 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
235 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
238 name
= strchr (name
+ len
, '$');
240 while (name
!= NULL
);
247 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
250 const char *const start
= name
;
251 char *last_elem
, *wp
;
253 /* Now fill the result path. While copying over the string we keep
254 track of the start of the last path element. When we come accross
255 a DST we copy over the value or (if the value is not available)
256 leave the entire path element out. */
257 last_elem
= wp
= result
;
261 if (__builtin_expect (*name
== '$', 0))
263 const char *repl
= NULL
;
267 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
268 INTUSE(__libc_enable_secure
))) != 0)
272 repl
= _dl_get_origin ();
277 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
278 repl
= GLRO(dl_platform
);
279 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
282 if (repl
!= NULL
&& repl
!= (const char *) -1)
284 wp
= __stpcpy (wp
, repl
);
289 /* We cannot use this path element, the value of the
290 replacement is unknown. */
293 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
297 /* No DST we recognize. */
303 if (is_path
&& *name
== ':')
307 while (*name
!= '\0');
315 /* Return copy of argument with all recognized dynamic string tokens
316 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
317 might not be possible to determine the path from which the object
318 belonging to the map is loaded. In this case the path element
319 containing $ORIGIN is left out. */
321 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
323 /* We make two runs over the string. First we determine how large the
324 resulting string is and then we copy it over. Since this is now
325 frequently executed operation we are looking here not for performance
326 but rather for code size. */
331 /* Determine the number of DST elements. */
332 cnt
= DL_DST_COUNT (s
, 1);
334 /* If we do not have to replace anything simply copy the string. */
335 if (__builtin_expect (cnt
, 0) == 0)
336 return local_strdup (s
);
338 /* Determine the length of the substituted string. */
339 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
341 /* Allocate the necessary memory. */
342 result
= (char *) malloc (total
+ 1);
346 return _dl_dst_substitute (l
, s
, result
, 1);
350 /* Add `name' to the list of names for a particular shared object.
351 `name' is expected to have been allocated with malloc and will
352 be freed if the shared object already has this name.
353 Returns false if the object already had this name. */
356 add_name_to_object (struct link_map
*l
, const char *name
)
358 struct libname_list
*lnp
, *lastp
;
359 struct libname_list
*newname
;
363 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
364 if (strcmp (name
, lnp
->name
) == 0)
367 name_len
= strlen (name
) + 1;
368 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
371 /* No more memory. */
372 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
375 /* The object should have a libname set from _dl_new_object. */
376 assert (lastp
!= NULL
);
378 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
379 newname
->next
= NULL
;
380 newname
->dont_free
= 0;
381 lastp
->next
= newname
;
384 /* Standard search directories. */
385 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
387 static size_t max_dirnamelen
;
389 static struct r_search_path_elem
**
390 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
391 int check_trusted
, const char *what
, const char *where
)
396 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
398 struct r_search_path_elem
*dirp
;
399 size_t len
= strlen (cp
);
401 /* `strsep' can pass an empty string. This has to be
402 interpreted as `use the current directory'. */
405 static const char curwd
[] = "./";
409 /* Remove trailing slashes (except for "/"). */
410 while (len
> 1 && cp
[len
- 1] == '/')
413 /* Now add one if there is none so far. */
414 if (len
> 0 && cp
[len
- 1] != '/')
417 /* Make sure we don't use untrusted directories if we run SUID. */
418 if (__builtin_expect (check_trusted
, 0))
420 const char *trun
= system_dirs
;
424 /* All trusted directories must be complete names. */
427 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
429 if (len
== system_dirs_len
[idx
]
430 && memcmp (trun
, cp
, len
) == 0)
437 trun
+= system_dirs_len
[idx
] + 1;
442 /* Simply drop this directory. */
446 /* See if this directory is already known. */
447 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
448 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
453 /* It is available, see whether it's on our own list. */
455 for (cnt
= 0; cnt
< nelems
; ++cnt
)
456 if (result
[cnt
] == dirp
)
460 result
[nelems
++] = dirp
;
465 enum r_dir_status init_val
;
466 size_t where_len
= where
? strlen (where
) + 1 : 0;
468 /* It's a new directory. Create an entry and add it. */
469 dirp
= (struct r_search_path_elem
*)
470 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
471 + where_len
+ len
+ 1);
473 _dl_signal_error (ENOMEM
, NULL
, NULL
,
474 N_("cannot create cache for search path"));
476 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
477 + ncapstr
* sizeof (enum r_dir_status
));
478 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
479 dirp
->dirnamelen
= len
;
481 if (len
> max_dirnamelen
)
482 max_dirnamelen
= len
;
484 /* We have to make sure all the relative directories are
485 never ignored. The current directory might change and
486 all our saved information would be void. */
487 init_val
= cp
[0] != '/' ? existing
: unknown
;
488 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
489 dirp
->status
[cnt
] = init_val
;
492 if (__builtin_expect (where
!= NULL
, 1))
493 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
494 + (ncapstr
* sizeof (enum r_dir_status
)),
499 dirp
->next
= GL(dl_all_dirs
);
500 GL(dl_all_dirs
) = dirp
;
502 /* Put it in the result array. */
503 result
[nelems
++] = dirp
;
507 /* Terminate the array. */
508 result
[nelems
] = NULL
;
516 decompose_rpath (struct r_search_path_struct
*sps
,
517 const char *rpath
, struct link_map
*l
, const char *what
)
519 /* Make a copy we can work with. */
520 const char *where
= l
->l_name
;
523 struct r_search_path_elem
**result
;
525 /* Initialize to please the compiler. */
526 const char *errstring
= NULL
;
528 /* First see whether we must forget the RUNPATH and RPATH from this
530 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
531 && !INTUSE(__libc_enable_secure
))
533 const char *inhp
= GLRO(dl_inhibit_rpath
);
537 const char *wp
= where
;
539 while (*inhp
== *wp
&& *wp
!= '\0')
545 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
547 /* This object is on the list of objects for which the
548 RUNPATH and RPATH must not be used. */
549 sps
->dirs
= (void *) -1;
553 while (*inhp
!= '\0')
557 while (*inhp
!= '\0');
560 /* Make a writable copy. At the same time expand possible dynamic
562 copy
= expand_dynamic_string_token (l
, rpath
);
565 errstring
= N_("cannot create RUNPATH/RPATH copy");
569 /* Count the number of necessary elements in the result array. */
571 for (cp
= copy
; *cp
!= '\0'; ++cp
)
575 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
576 number of necessary entries. */
577 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
582 errstring
= N_("cannot create cache for search path");
584 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
587 fillin_rpath (copy
, result
, ":", 0, what
, where
);
589 /* Free the copied RPATH string. `fillin_rpath' make own copies if
594 /* The caller will change this value if we haven't used a real malloc. */
599 /* Make sure cached path information is stored in *SP
600 and return true if there are any paths to search there. */
602 cache_rpath (struct link_map
*l
,
603 struct r_search_path_struct
*sp
,
607 if (sp
->dirs
== (void *) -1)
610 if (sp
->dirs
!= NULL
)
613 if (l
->l_info
[tag
] == NULL
)
615 /* There is no path. */
616 sp
->dirs
= (void *) -1;
620 /* Make sure the cache information is available. */
621 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
622 + l
->l_info
[tag
]->d_un
.d_val
),
629 _dl_init_paths (const char *llp
)
633 struct r_search_path_elem
*pelem
, **aelem
;
638 /* Initialize to please the compiler. */
639 const char *errstring
= NULL
;
641 /* Fill in the information about the application's RPATH and the
642 directories addressed by the LD_LIBRARY_PATH environment variable. */
644 /* Get the capabilities. */
645 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
646 &ncapstr
, &max_capstrlen
);
648 /* First set up the rest of the default search directory entries. */
649 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
650 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
651 if (rtld_search_dirs
.dirs
== NULL
)
653 errstring
= N_("cannot create search path array");
655 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
658 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
659 + ncapstr
* sizeof (enum r_dir_status
))
660 / sizeof (struct r_search_path_elem
));
662 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
663 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
664 * round_size
* sizeof (struct r_search_path_elem
));
665 if (rtld_search_dirs
.dirs
[0] == NULL
)
667 errstring
= N_("cannot create cache for search path");
671 rtld_search_dirs
.malloced
= 0;
672 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
682 pelem
->what
= "system search path";
685 pelem
->dirname
= strp
;
686 pelem
->dirnamelen
= system_dirs_len
[idx
];
687 strp
+= system_dirs_len
[idx
] + 1;
689 /* System paths must be absolute. */
690 assert (pelem
->dirname
[0] == '/');
691 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
692 pelem
->status
[cnt
] = unknown
;
694 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
698 while (idx
< nsystem_dirs_len
);
700 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
704 /* This points to the map of the main object. */
705 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
708 assert (l
->l_type
!= lt_loaded
);
710 if (l
->l_info
[DT_RUNPATH
])
712 /* Allocate room for the search path and fill in information
714 decompose_rpath (&l
->l_runpath_dirs
,
715 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
716 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
719 /* The RPATH is ignored. */
720 l
->l_rpath_dirs
.dirs
= (void *) -1;
724 l
->l_runpath_dirs
.dirs
= (void *) -1;
726 if (l
->l_info
[DT_RPATH
])
728 /* Allocate room for the search path and fill in information
730 decompose_rpath (&l
->l_rpath_dirs
,
731 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
732 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
734 l
->l_rpath_dirs
.malloced
= 0;
737 l
->l_rpath_dirs
.dirs
= (void *) -1;
742 if (llp
!= NULL
&& *llp
!= '\0')
745 const char *cp
= llp
;
750 size_t cnt
= DL_DST_COUNT (llp
, 1);
751 if (__builtin_expect (cnt
== 0, 1))
752 llp_tmp
= strdupa (llp
);
755 /* Determine the length of the substituted string. */
756 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
758 /* Allocate the necessary memory. */
759 llp_tmp
= (char *) alloca (total
+ 1);
760 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
763 llp_tmp
= strdupa (llp
);
766 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
771 if (*cp
== ':' || *cp
== ';')
776 env_path_list
.dirs
= (struct r_search_path_elem
**)
777 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
778 if (env_path_list
.dirs
== NULL
)
780 errstring
= N_("cannot create cache for search path");
784 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
785 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
788 if (env_path_list
.dirs
[0] == NULL
)
790 free (env_path_list
.dirs
);
791 env_path_list
.dirs
= (void *) -1;
794 env_path_list
.malloced
= 0;
797 env_path_list
.dirs
= (void *) -1;
799 /* Remember the last search directory added at startup. */
800 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
805 __attribute__ ((noreturn
, noinline
))
806 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
807 const char *msg
, struct r_debug
*r
)
809 /* The file might already be closed. */
814 /* Remove the stillborn object from the list and free it. */
815 assert (l
->l_next
== NULL
);
816 if (l
->l_prev
== NULL
)
817 /* No other module loaded. This happens only in the static library,
818 or in rtld under --verify. */
819 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
821 l
->l_prev
->l_next
= NULL
;
822 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
829 r
->r_state
= RT_CONSISTENT
;
833 _dl_signal_error (code
, name
, NULL
, msg
);
837 /* Map in the shared object NAME, actually located in REALNAME, and already
840 #ifndef EXTERNAL_MAP_FROM_FD
844 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
845 char *realname
, struct link_map
*loader
, int l_type
,
846 int mode
, void **stack_endp
, Lmid_t nsid
)
848 struct link_map
*l
= NULL
;
849 const ElfW(Ehdr
) *header
;
850 const ElfW(Phdr
) *phdr
;
851 const ElfW(Phdr
) *ph
;
855 /* Initialize to keep the compiler happy. */
856 const char *errstring
= NULL
;
858 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
859 bool make_consistent
= false;
861 /* Get file information. */
862 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
864 errstring
= N_("cannot stat shared object");
868 lose (errval
, fd
, name
, realname
, l
, errstring
,
869 make_consistent
? r
: NULL
);
873 /* Look again to see if the real name matched another already loaded. */
874 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
875 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
877 /* The object is already loaded.
878 Just bump its reference count and return it. */
881 /* If the name is not in the list of names for this object add
884 add_name_to_object (l
, name
);
891 /* When loading into a namespace other than the base one we must
892 avoid loading ld.so since there can only be one copy. Ever. */
893 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
894 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
895 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
896 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
898 /* This is indeed ld.so. Create a new link_map which refers to
899 the real one for almost everything. */
900 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
904 /* Refer to the real descriptor. */
905 l
->l_real
= &GL(dl_rtld_map
);
907 /* No need to bump the refcount of the real object, ld.so will
908 never be unloaded. */
915 if (mode
& RTLD_NOLOAD
)
916 /* We are not supposed to load the object unless it is already
917 loaded. So return now. */
920 /* Print debugging message. */
921 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
922 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
924 /* This is the ELF header. We read it in `open_verify'. */
925 header
= (void *) fbp
->buf
;
929 if (_dl_zerofd
== -1)
931 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
932 if (_dl_zerofd
== -1)
935 _dl_signal_error (errno
, NULL
, NULL
,
936 N_("cannot open zero fill device"));
941 /* Signal that we are going to add new objects. */
942 if (r
->r_state
== RT_CONSISTENT
)
945 /* Auditing checkpoint: we are going to add new objects. */
946 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
948 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
949 /* Do not call the functions for any auditing object. */
950 if (head
->l_auditing
== 0)
952 struct audit_ifaces
*afct
= GLRO(dl_audit
);
953 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
955 if (afct
->activity
!= NULL
)
956 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
964 /* Notify the debugger we have added some objects. We need to
965 call _dl_debug_initialize in a static program in case dynamic
966 linking has not been used before. */
969 make_consistent
= true;
972 assert (r
->r_state
== RT_ADD
);
974 /* Enter the new object in the list of loaded objects. */
975 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
976 if (__builtin_expect (l
== NULL
, 0))
981 errstring
= N_("cannot create shared object descriptor");
982 goto call_lose_errno
;
985 /* Extract the remaining details we need from the ELF header
986 and then read in the program header table. */
987 l
->l_entry
= header
->e_entry
;
988 type
= header
->e_type
;
989 l
->l_phnum
= header
->e_phnum
;
991 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
992 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
993 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
996 phdr
= alloca (maplength
);
997 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
998 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1000 errstring
= N_("cannot read file data");
1001 goto call_lose_errno
;
1005 /* Presumed absent PT_GNU_STACK. */
1006 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
1009 /* Scan the program header table, collecting its load commands. */
1012 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1015 } loadcmds
[l
->l_phnum
], *c
;
1016 size_t nloadcmds
= 0;
1017 bool has_holes
= false;
1019 /* The struct is initialized to zero so this is not necessary:
1023 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1026 /* These entries tell us where to find things once the file's
1027 segments are mapped in. We record the addresses it says
1028 verbatim, and later correct for the run-time load address. */
1030 l
->l_ld
= (void *) ph
->p_vaddr
;
1031 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1035 l
->l_phdr
= (void *) ph
->p_vaddr
;
1039 /* A load command tells us to map in part of the file.
1040 We record the load commands and process them all later. */
1041 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1044 errstring
= N_("ELF load command alignment not page-aligned");
1047 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1048 & (ph
->p_align
- 1)) != 0, 0))
1051 = N_("ELF load command address/offset not properly aligned");
1055 c
= &loadcmds
[nloadcmds
++];
1056 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1057 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1058 & ~(GLRO(dl_pagesize
) - 1));
1059 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1060 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1061 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1063 /* Determine whether there is a gap between the last segment
1065 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1068 /* Optimize a common case. */
1069 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1070 c
->prot
= (PF_TO_PROT
1071 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1074 if (ph
->p_flags
& PF_R
)
1075 c
->prot
|= PROT_READ
;
1076 if (ph
->p_flags
& PF_W
)
1077 c
->prot
|= PROT_WRITE
;
1078 if (ph
->p_flags
& PF_X
)
1079 c
->prot
|= PROT_EXEC
;
1084 if (ph
->p_memsz
== 0)
1085 /* Nothing to do for an empty segment. */
1088 l
->l_tls_blocksize
= ph
->p_memsz
;
1089 l
->l_tls_align
= ph
->p_align
;
1090 if (ph
->p_align
== 0)
1091 l
->l_tls_firstbyte_offset
= 0;
1093 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1094 l
->l_tls_initimage_size
= ph
->p_filesz
;
1095 /* Since we don't know the load address yet only store the
1096 offset. We will adjust it later. */
1097 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1099 /* If not loading the initial set of shared libraries,
1100 check whether we should permit loading a TLS segment. */
1101 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1102 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1103 not set up TLS data structures, so don't use them now. */
1104 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1106 /* Assign the next available module ID. */
1107 l
->l_tls_modid
= _dl_next_tls_modid ();
1112 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1113 /* We are loading the executable itself when the dynamic linker
1114 was executed directly. The setup will happen later. */
1117 /* In a static binary there is no way to tell if we dynamically
1118 loaded libpthread. */
1119 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1122 /* We have not yet loaded libpthread.
1123 We can do the TLS setup right now! */
1127 /* The first call allocates TLS bookkeeping data structures.
1128 Then we allocate the TCB for the initial thread. */
1129 if (__builtin_expect (_dl_tls_setup (), 0)
1130 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1135 cannot allocate TLS data structures for initial thread");
1139 /* Now we install the TCB in the thread register. */
1140 errstring
= TLS_INIT_TP (tcb
, 0);
1141 if (__builtin_expect (errstring
== NULL
, 1))
1143 /* Now we are all good. */
1144 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1148 /* The kernel is too old or somesuch. */
1150 _dl_deallocate_tls (tcb
, 1);
1154 /* Uh-oh, the binary expects TLS support but we cannot
1157 errstring
= N_("cannot handle TLS data");
1162 stack_flags
= ph
->p_flags
;
1166 l
->l_relro_addr
= ph
->p_vaddr
;
1167 l
->l_relro_size
= ph
->p_memsz
;
1171 if (__builtin_expect (nloadcmds
== 0, 0))
1173 /* This only happens for a bogus object that will be caught with
1174 another error below. But we don't want to go through the
1175 calculations below using NLOADCMDS - 1. */
1176 errstring
= N_("object file has no loadable segments");
1180 /* Now process the load commands and map segments into memory. */
1183 /* Length of the sections to be loaded. */
1184 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1186 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1188 /* This is a position-independent shared object. We can let the
1189 kernel map it anywhere it likes, but we must have space for all
1190 the segments in their specified positions relative to the first.
1191 So we map the first segment without MAP_FIXED, but with its
1192 extent increased to cover all the segments. Then we remove
1193 access from excess portion, and there is known sufficient space
1194 there to remap from the later segments.
1196 As a refinement, sometimes we have an address that we would
1197 prefer to map such objects at; but this is only a preference,
1198 the OS can do whatever it likes. */
1200 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1201 c
->mapstart
& GLRO(dl_use_load_bias
))
1202 - MAP_BASE_ADDR (l
));
1204 /* Remember which part of the address space this object uses. */
1205 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1209 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1212 errstring
= N_("failed to map segment from shared object");
1213 goto call_lose_errno
;
1216 l
->l_map_end
= l
->l_map_start
+ maplength
;
1217 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1220 /* Change protection on the excess portion to disallow all access;
1221 the portions we do not remap later will be inaccessible as if
1222 unallocated. Then jump into the normal segment-mapping loop to
1223 handle the portion of the segment past the end of the file
1225 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1226 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1229 l
->l_contiguous
= 1;
1234 /* This object is loaded at a fixed address. This must never
1235 happen for objects loaded with dlopen(). */
1236 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1238 errstring
= N_("cannot dynamically load executable");
1242 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1244 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1247 /* Remember which part of the address space this object uses. */
1248 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1249 l
->l_map_end
= l
->l_map_start
+ maplength
;
1250 l
->l_contiguous
= !has_holes
;
1252 while (c
< &loadcmds
[nloadcmds
])
1254 if (c
->mapend
> c
->mapstart
1255 /* Map the segment contents from the file. */
1256 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1257 c
->mapend
- c
->mapstart
, c
->prot
,
1258 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1264 if (c
->prot
& PROT_EXEC
)
1265 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1268 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1269 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1270 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1271 /* Found the program header in this segment. */
1272 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1274 if (c
->allocend
> c
->dataend
)
1276 /* Extra zero pages should appear at the end of this segment,
1277 after the data mapped from the file. */
1278 ElfW(Addr
) zero
, zeroend
, zeropage
;
1280 zero
= l
->l_addr
+ c
->dataend
;
1281 zeroend
= l
->l_addr
+ c
->allocend
;
1282 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1283 & ~(GLRO(dl_pagesize
) - 1));
1285 if (zeroend
< zeropage
)
1286 /* All the extra data is in the last page of the segment.
1287 We can just zero it. */
1290 if (zeropage
> zero
)
1292 /* Zero the final part of the last page of the segment. */
1293 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1296 if (__mprotect ((caddr_t
) (zero
1297 & ~(GLRO(dl_pagesize
) - 1)),
1298 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1300 errstring
= N_("cannot change memory protections");
1301 goto call_lose_errno
;
1304 memset ((void *) zero
, '\0', zeropage
- zero
);
1305 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1306 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1307 GLRO(dl_pagesize
), c
->prot
);
1310 if (zeroend
> zeropage
)
1312 /* Map the remaining zero pages in from the zero fill FD. */
1314 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1315 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1317 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1319 errstring
= N_("cannot map zero-fill pages");
1320 goto call_lose_errno
;
1331 if (__builtin_expect (type
== ET_DYN
, 0))
1333 errstring
= N_("object file has no dynamic section");
1338 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1340 elf_get_dynamic_info (l
, NULL
);
1342 /* Make sure we are not dlopen'ing an object that has the
1343 DF_1_NOOPEN flag set. */
1344 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1345 && (mode
& __RTLD_DLOPEN
))
1347 /* We are not supposed to load this object. Free all resources. */
1348 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1350 if (!l
->l_libname
->dont_free
)
1351 free (l
->l_libname
);
1353 if (l
->l_phdr_allocated
)
1354 free ((void *) l
->l_phdr
);
1356 errstring
= N_("shared object cannot be dlopen()ed");
1360 if (l
->l_phdr
== NULL
)
1362 /* The program header is not contained in any of the segments.
1363 We have to allocate memory ourself and copy it over from out
1365 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1366 * sizeof (ElfW(Phdr
)));
1369 errstring
= N_("cannot allocate memory for program header");
1370 goto call_lose_errno
;
1373 l
->l_phdr
= memcpy (newp
, phdr
,
1374 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1375 l
->l_phdr_allocated
= 1;
1378 /* Adjust the PT_PHDR value by the runtime load address. */
1379 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1381 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1383 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1386 errstring
= N_("invalid caller");
1390 /* The stack is presently not executable, but this module
1391 requires that it be executable. We must change the
1392 protection of the variable which contains the flags used in
1393 the mprotect calls. */
1395 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1397 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1398 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1400 struct link_map
*const m
= &GL(dl_rtld_map
);
1401 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1403 & -GLRO(dl_pagesize
));
1404 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1406 /* The variable lies in the region protected by RELRO. */
1407 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1408 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1409 __mprotect ((void *) p
, s
, PROT_READ
);
1412 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1416 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1418 #ifdef check_consistency
1419 check_consistency ();
1422 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1426 cannot enable executable stack as shared object requires");
1431 /* Adjust the address of the TLS initialization image. */
1432 if (l
->l_tls_initimage
!= NULL
)
1433 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1435 /* We are done mapping in the file. We no longer need the descriptor. */
1436 if (__builtin_expect (__close (fd
) != 0, 0))
1438 errstring
= N_("cannot close file descriptor");
1439 goto call_lose_errno
;
1441 /* Signal that we closed the file. */
1444 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1445 l
->l_type
= lt_executable
;
1447 l
->l_entry
+= l
->l_addr
;
1449 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1450 _dl_debug_printf ("\
1451 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1452 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1453 (int) sizeof (void *) * 2,
1454 (unsigned long int) l
->l_ld
,
1455 (int) sizeof (void *) * 2,
1456 (unsigned long int) l
->l_addr
,
1457 (int) sizeof (void *) * 2, maplength
,
1458 (int) sizeof (void *) * 2,
1459 (unsigned long int) l
->l_entry
,
1460 (int) sizeof (void *) * 2,
1461 (unsigned long int) l
->l_phdr
,
1462 (int) sizeof (void *) * 2, l
->l_phnum
);
1464 /* Set up the symbol hash table. */
1467 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1468 have to do this for the main map. */
1469 if ((mode
& RTLD_DEEPBIND
) == 0
1470 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1471 && &l
->l_searchlist
!= l
->l_scope
[0])
1473 /* Create an appropriate searchlist. It contains only this map.
1474 This is the definition of DT_SYMBOLIC in SysVr4. */
1475 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1476 l
->l_symbolic_searchlist
.r_nlist
= 1;
1478 /* Now move the existing entries one back. */
1479 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1480 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1482 /* Now add the new entry. */
1483 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1486 /* Remember whether this object must be initialized first. */
1487 if (l
->l_flags_1
& DF_1_INITFIRST
)
1488 GL(dl_initfirst
) = l
;
1490 /* Finally the file information. */
1491 l
->l_dev
= st
.st_dev
;
1492 l
->l_ino
= st
.st_ino
;
1494 /* When we profile the SONAME might be needed for something else but
1495 loading. Add it right away. */
1496 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1497 && l
->l_info
[DT_SONAME
] != NULL
)
1498 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1499 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1502 /* Auditing checkpoint: we have a new object. */
1503 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1504 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1506 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1507 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1509 if (afct
->objopen
!= NULL
)
1511 l
->l_audit
[cnt
].bindflags
1512 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1514 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1525 /* Print search path. */
1527 print_search_path (struct r_search_path_elem
**list
,
1528 const char *what
, const char *name
)
1530 char buf
[max_dirnamelen
+ max_capstrlen
];
1533 _dl_debug_printf (" search path=");
1535 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1537 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1540 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1541 if ((*list
)->status
[cnt
] != nonexisting
)
1543 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1544 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1549 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1557 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1558 name
[0] ? name
: rtld_progname
);
1560 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1563 /* Open a file and verify it is an ELF file for this architecture. We
1564 ignore only ELF files for other architectures. Non-ELF files and
1565 ELF files with different header information cause fatal errors since
1566 this could mean there is something wrong in the installation and the
1567 user might want to know about this. */
1569 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1570 int whatcode
, bool *found_other_class
, bool free_name
)
1572 /* This is the expected ELF header. */
1573 #define ELF32_CLASS ELFCLASS32
1574 #define ELF64_CLASS ELFCLASS64
1575 #ifndef VALID_ELF_HEADER
1576 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1577 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1578 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1580 static const unsigned char expected
[EI_PAD
] =
1582 [EI_MAG0
] = ELFMAG0
,
1583 [EI_MAG1
] = ELFMAG1
,
1584 [EI_MAG2
] = ELFMAG2
,
1585 [EI_MAG3
] = ELFMAG3
,
1586 [EI_CLASS
] = ELFW(CLASS
),
1587 [EI_DATA
] = byteorder
,
1588 [EI_VERSION
] = EV_CURRENT
,
1589 [EI_OSABI
] = ELFOSABI_SYSV
,
1594 ElfW(Word
) vendorlen
;
1598 } expected_note
= { 4, 16, 1, "GNU" };
1599 /* Initialize it to make the compiler happy. */
1600 const char *errstring
= NULL
;
1604 /* Give the auditing libraries a chance. */
1605 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1606 && loader
->l_auditing
== 0)
1608 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1609 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1611 if (afct
->objsearch
!= NULL
)
1613 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1616 /* Ignore the path. */
1625 /* Open the file. We always open files read-only. */
1626 int fd
= __open (name
, O_RDONLY
);
1630 ElfW(Phdr
) *phdr
, *ph
;
1631 ElfW(Word
) *abi_note
;
1632 unsigned int osversion
;
1635 /* We successfully openened the file. Now verify it is a file
1638 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1640 /* This is where the ELF header is loaded. */
1641 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1642 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1644 /* Now run the tests. */
1645 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1648 errstring
= (errval
== 0
1649 ? N_("file too short") : N_("cannot read file data"));
1653 char *realname
= (char *) name
;
1654 name
= strdupa (realname
);
1657 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1660 /* Skip these checks for now */
1662 /* See whether the ELF header is what we expect. */
1663 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1666 /* Something is wrong. */
1667 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1668 #if BYTE_ORDER == LITTLE_ENDIAN
1669 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1670 (ELFMAG1
<< (EI_MAG1
* 8)) |
1671 (ELFMAG2
<< (EI_MAG2
* 8)) |
1672 (ELFMAG3
<< (EI_MAG3
* 8)))
1674 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1675 (ELFMAG1
<< (EI_MAG2
* 8)) |
1676 (ELFMAG2
<< (EI_MAG1
* 8)) |
1677 (ELFMAG3
<< (EI_MAG0
* 8)))
1680 errstring
= N_("invalid ELF header");
1681 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1683 /* This is not a fatal error. On architectures where
1684 32-bit and 64-bit binaries can be run this might
1686 *found_other_class
= true;
1689 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1691 if (BYTE_ORDER
== BIG_ENDIAN
)
1692 errstring
= N_("ELF file data encoding not big-endian");
1694 errstring
= N_("ELF file data encoding not little-endian");
1696 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1698 = N_("ELF file version ident does not match current one");
1699 /* XXX We should be able so set system specific versions which are
1701 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1702 errstring
= N_("ELF file OS ABI invalid");
1703 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1704 errstring
= N_("ELF file ABI version invalid");
1706 /* Otherwise we don't know what went wrong. */
1707 errstring
= N_("internal error");
1713 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1715 errstring
= N_("ELF file version does not match current one");
1718 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1720 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1721 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1723 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1726 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1727 != sizeof (ElfW(Phdr
)))
1729 errstring
= N_("ELF file's phentsize not the expected size");
1733 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1734 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1735 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1738 phdr
= alloca (maplength
);
1739 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1740 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1744 errstring
= N_("cannot read file data");
1749 /* Check .note.ABI-tag if present. */
1750 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1751 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1753 ElfW(Addr
) size
= ph
->p_filesz
;
1755 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1756 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1759 abi_note
= alloca (size
);
1760 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1761 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1765 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1767 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1768 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1769 + ROUND (abi_note
[0])
1770 + ROUND (abi_note
[1]);
1772 if (size
- 32 < note_size
)
1778 abi_note
= (void *) abi_note
+ note_size
;
1784 osversion
= (abi_note
[5] & 0xff) * 65536
1785 + (abi_note
[6] & 0xff) * 256
1786 + (abi_note
[7] & 0xff);
1787 if (abi_note
[4] != __ABI_TAG_OS
1788 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1792 __set_errno (ENOENT
);
1803 /* Try to open NAME in one of the directories in *DIRSP.
1804 Return the fd, or -1. If successful, fill in *REALNAME
1805 with the malloc'd full directory name. If it turns out
1806 that none of the directories in *DIRSP exists, *DIRSP is
1807 replaced with (void *) -1, and the old value is free()d
1808 if MAY_FREE_DIRS is true. */
1811 open_path (const char *name
, size_t namelen
, int preloaded
,
1812 struct r_search_path_struct
*sps
, char **realname
,
1813 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1814 bool *found_other_class
)
1816 struct r_search_path_elem
**dirs
= sps
->dirs
;
1819 const char *current_what
= NULL
;
1822 if (__builtin_expect (dirs
== NULL
, 0))
1823 /* We're called before _dl_init_paths when loading the main executable
1824 given on the command line when rtld is run directly. */
1827 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1830 struct r_search_path_elem
*this_dir
= *dirs
;
1837 /* If we are debugging the search for libraries print the path
1838 now if it hasn't happened now. */
1839 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1840 && current_what
!= this_dir
->what
)
1842 current_what
= this_dir
->what
;
1843 print_search_path (dirs
, current_what
, this_dir
->where
);
1846 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1847 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1849 /* Skip this directory if we know it does not exist. */
1850 if (this_dir
->status
[cnt
] == nonexisting
)
1854 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1859 /* Print name we try if this is wanted. */
1860 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1861 _dl_debug_printf (" trying file=%s\n", buf
);
1863 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1865 if (this_dir
->status
[cnt
] == unknown
)
1868 this_dir
->status
[cnt
] = existing
;
1869 /* Do not update the directory information when loading
1870 auditing code. We must try to disturb the program as
1871 little as possible. */
1872 else if (loader
== NULL
1873 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1875 /* We failed to open machine dependent library. Let's
1876 test whether there is any directory at all. */
1879 buf
[buflen
- namelen
- 1] = '\0';
1881 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1882 || ! S_ISDIR (st
.st_mode
))
1883 /* The directory does not exist or it is no directory. */
1884 this_dir
->status
[cnt
] = nonexisting
;
1886 this_dir
->status
[cnt
] = existing
;
1890 /* Remember whether we found any existing directory. */
1891 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1893 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1894 && INTUSE(__libc_enable_secure
))
1896 /* This is an extra security effort to make sure nobody can
1897 preload broken shared objects which are in the trusted
1898 directories and so exploit the bugs. */
1901 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1902 || (st
.st_mode
& S_ISUID
) == 0)
1904 /* The shared object cannot be tested for being SUID
1905 or this bit is not set. In this case we must not
1909 /* We simply ignore the file, signal this by setting
1910 the error value which would have been set by `open'. */
1918 *realname
= (char *) malloc (buflen
);
1919 if (*realname
!= NULL
)
1921 memcpy (*realname
, buf
, buflen
);
1926 /* No memory for the name, we certainly won't be able
1927 to load and link it. */
1932 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1933 /* The file exists and is readable, but something went wrong. */
1936 /* Remember whether we found anything. */
1939 while (*++dirs
!= NULL
);
1941 /* Remove the whole path if none of the directories exists. */
1942 if (__builtin_expect (! any
, 0))
1944 /* Paths which were allocated using the minimal malloc() in ld.so
1945 must not be freed using the general free() in libc. */
1949 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1951 if (sps
!= &rtld_search_dirs
)
1952 sps
->dirs
= (void *) -1;
1958 /* Map in the shared object file NAME. */
1962 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1963 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1972 assert (nsid
< DL_NNS
);
1974 /* Look for this name among those already loaded. */
1975 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1977 /* If the requested name matches the soname of a loaded object,
1978 use that object. Elide this check for names that have not
1980 if (__builtin_expect (l
->l_faked
, 0) != 0
1981 || __builtin_expect (l
->l_removed
, 0) != 0)
1983 if (!_dl_name_match_p (name
, l
))
1987 if (__builtin_expect (l
->l_soname_added
, 1)
1988 || l
->l_info
[DT_SONAME
] == NULL
)
1991 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1992 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1993 if (strcmp (name
, soname
) != 0)
1996 /* We have a match on a new name -- cache it. */
1997 add_name_to_object (l
, soname
);
1998 l
->l_soname_added
= 1;
2001 /* We have a match. */
2005 /* Display information if we are debugging. */
2006 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2008 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2010 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2013 /* Give the auditing libraries a chance to change the name before we
2015 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2016 && (loader
== NULL
|| loader
->l_auditing
== 0))
2018 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2019 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2021 if (afct
->objsearch
!= NULL
)
2023 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2027 /* Do not try anything further. */
2038 /* Will be true if we found a DSO which is of the other ELF class. */
2039 bool found_other_class
= false;
2041 if (strchr (name
, '/') == NULL
)
2043 /* Search for NAME in several places. */
2045 size_t namelen
= strlen (name
) + 1;
2047 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2048 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2052 /* When the object has the RUNPATH information we don't use any
2054 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2056 /* This is the executable's map (if there is one). Make sure that
2057 we do not look at it twice. */
2058 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2059 bool did_main_map
= false;
2061 /* First try the DT_RPATH of the dependent object that caused NAME
2062 to be loaded. Then that object's dependent, and on up. */
2063 for (l
= loader
; l
; l
= l
->l_loader
)
2064 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2066 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2067 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2068 &found_other_class
);
2072 did_main_map
|= l
== main_map
;
2075 /* If dynamically linked, try the DT_RPATH of the executable
2076 itself. NB: we do this for lookups in any namespace. */
2077 if (fd
== -1 && !did_main_map
2078 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2079 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2081 fd
= open_path (name
, namelen
, preloaded
, &main_map
->l_rpath_dirs
,
2082 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2083 &found_other_class
);
2086 /* Try the LD_LIBRARY_PATH environment variable. */
2087 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2088 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2090 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2091 LA_SER_LIBPATH
, &found_other_class
);
2093 /* Look at the RUNPATH information for this binary. */
2094 if (fd
== -1 && loader
!= NULL
2095 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2096 DT_RUNPATH
, "RUNPATH"))
2097 fd
= open_path (name
, namelen
, preloaded
,
2098 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2099 LA_SER_RUNPATH
, &found_other_class
);
2102 && (__builtin_expect (! preloaded
, 1)
2103 || ! INTUSE(__libc_enable_secure
)))
2105 /* Check the list of libraries in the file /etc/ld.so.cache,
2106 for compatibility with Linux's ldconfig program. */
2107 const char *cached
= _dl_load_cache_lookup (name
);
2112 // XXX Correct to unconditionally default to namespace 0?
2113 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2118 /* If the loader has the DF_1_NODEFLIB flag set we must not
2119 use a cache entry from any of these directories. */
2122 /* 'l' is always != NULL for dynamically linked objects. */
2125 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2127 const char *dirp
= system_dirs
;
2128 unsigned int cnt
= 0;
2132 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2134 /* The prefix matches. Don't use the entry. */
2139 dirp
+= system_dirs_len
[cnt
] + 1;
2142 while (cnt
< nsystem_dirs_len
);
2147 fd
= open_verify (cached
,
2148 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2149 LA_SER_CONFIG
, &found_other_class
, false);
2150 if (__builtin_expect (fd
!= -1, 1))
2152 realname
= local_strdup (cached
);
2153 if (realname
== NULL
)
2163 /* Finally, try the default path. */
2165 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2166 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2167 && rtld_search_dirs
.dirs
!= (void *) -1)
2168 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2169 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2171 /* Add another newline when we are tracing the library loading. */
2172 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2173 _dl_debug_printf ("\n");
2177 /* The path may contain dynamic string tokens. */
2179 ? expand_dynamic_string_token (loader
, name
)
2180 : local_strdup (name
));
2181 if (realname
== NULL
)
2185 fd
= open_verify (realname
, &fb
,
2186 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2187 &found_other_class
, true);
2188 if (__builtin_expect (fd
, 0) == -1)
2196 /* In case the LOADER information has only been provided to get to
2197 the appropriate RUNPATH/RPATH information we do not need it
2199 if (mode
& __RTLD_CALLMAP
)
2202 if (__builtin_expect (fd
, 0) == -1)
2205 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2207 /* We haven't found an appropriate library. But since we
2208 are only interested in the list of libraries this isn't
2209 so severe. Fake an entry with all the information we
2211 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2213 /* Enter the new object in the list of loaded objects. */
2214 if ((name_copy
= local_strdup (name
)) == NULL
2215 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2216 mode
, nsid
)) == NULL
)
2219 _dl_signal_error (ENOMEM
, name
, NULL
,
2220 N_("cannot create shared object descriptor"));
2222 /* Signal that this is a faked entry. */
2224 /* Since the descriptor is initialized with zero we do not
2226 l->l_reserved = 0; */
2227 l
->l_buckets
= &dummy_bucket
;
2233 else if (found_other_class
)
2234 _dl_signal_error (0, name
, NULL
,
2235 ELFW(CLASS
) == ELFCLASS32
2236 ? N_("wrong ELF class: ELFCLASS64")
2237 : N_("wrong ELF class: ELFCLASS32"));
2239 _dl_signal_error (errno
, name
, NULL
,
2240 N_("cannot open shared object file"));
2243 void *stack_end
= __libc_stack_end
;
2244 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2251 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2259 unsigned int idx
= 0;
2260 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2261 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2262 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2264 if (sps
->dirs
!= (void *) -1)
2266 struct r_search_path_elem
**dirs
= sps
->dirs
;
2269 const struct r_search_path_elem
*const r
= *dirs
++;
2273 si
->dls_size
+= MAX (2, r
->dirnamelen
);
2277 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2278 sp
->dls_name
= allocptr
;
2279 if (r
->dirnamelen
< 2)
2280 *allocptr
++ = r
->dirnamelen
? '/' : '.';
2282 allocptr
= __mempcpy (allocptr
,
2283 r
->dirname
, r
->dirnamelen
- 1);
2285 sp
->dls_flags
= flags
;
2288 while (*dirs
!= NULL
);
2292 /* When the object has the RUNPATH information we don't use any RPATHs. */
2293 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2295 /* First try the DT_RPATH of the dependent object that caused NAME
2296 to be loaded. Then that object's dependent, and on up. */
2298 struct link_map
*l
= loader
;
2301 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2302 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2307 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2308 if (loader
->l_ns
== LM_ID_BASE
)
2310 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2311 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2312 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2313 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2317 /* Try the LD_LIBRARY_PATH environment variable. */
2318 add_path (&env_path_list
, XXX_ENV
);
2320 /* Look at the RUNPATH information for this binary. */
2321 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2322 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2325 Here is where ld.so.cache gets checked, but we don't have
2326 a way to indicate that in the results for Dl_serinfo. */
2328 /* Finally, try the default path. */
2329 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2330 add_path (&rtld_search_dirs
, XXX_default
);
2333 /* Count the struct size before the string area, which we didn't
2334 know before we completed dls_cnt. */
2335 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;