1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004, 2005 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
== '$', 0))
263 const char *repl
= NULL
;
267 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
268 INTUSE(__libc_enable_secure
))) != 0)
270 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
271 repl
= GLRO(dl_platform
);
272 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
275 if (repl
!= NULL
&& repl
!= (const char *) -1)
277 wp
= __stpcpy (wp
, repl
);
282 /* We cannot use this path element, the value of the
283 replacement is unknown. */
286 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
290 /* No DST we recognize. */
296 if (is_path
&& *name
== ':')
300 while (*name
!= '\0');
308 /* Return copy of argument with all recognized dynamic string tokens
309 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
310 might not be possible to determine the path from which the object
311 belonging to the map is loaded. In this case the path element
312 containing $ORIGIN is left out. */
314 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
316 /* We make two runs over the string. First we determine how large the
317 resulting string is and then we copy it over. Since this is now
318 frequently executed operation we are looking here not for performance
319 but rather for code size. */
324 /* Determine the number of DST elements. */
325 cnt
= DL_DST_COUNT (s
, 1);
327 /* If we do not have to replace anything simply copy the string. */
328 if (__builtin_expect (cnt
, 0) == 0)
329 return local_strdup (s
);
331 /* Determine the length of the substituted string. */
332 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
334 /* Allocate the necessary memory. */
335 result
= (char *) malloc (total
+ 1);
339 return _dl_dst_substitute (l
, s
, result
, 1);
343 /* Add `name' to the list of names for a particular shared object.
344 `name' is expected to have been allocated with malloc and will
345 be freed if the shared object already has this name.
346 Returns false if the object already had this name. */
349 add_name_to_object (struct link_map
*l
, const char *name
)
351 struct libname_list
*lnp
, *lastp
;
352 struct libname_list
*newname
;
356 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
357 if (strcmp (name
, lnp
->name
) == 0)
360 name_len
= strlen (name
) + 1;
361 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
364 /* No more memory. */
365 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
368 /* The object should have a libname set from _dl_new_object. */
369 assert (lastp
!= NULL
);
371 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
372 newname
->next
= NULL
;
373 newname
->dont_free
= 0;
374 lastp
->next
= newname
;
377 /* Standard search directories. */
378 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
380 static size_t max_dirnamelen
;
382 static struct r_search_path_elem
**
383 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
384 int check_trusted
, const char *what
, const char *where
)
389 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
391 struct r_search_path_elem
*dirp
;
392 size_t len
= strlen (cp
);
394 /* `strsep' can pass an empty string. This has to be
395 interpreted as `use the current directory'. */
398 static const char curwd
[] = "./";
402 /* Remove trailing slashes (except for "/"). */
403 while (len
> 1 && cp
[len
- 1] == '/')
406 /* Now add one if there is none so far. */
407 if (len
> 0 && cp
[len
- 1] != '/')
410 /* Make sure we don't use untrusted directories if we run SUID. */
411 if (__builtin_expect (check_trusted
, 0))
413 const char *trun
= system_dirs
;
417 /* All trusted directories must be complete names. */
420 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
422 if (len
== system_dirs_len
[idx
]
423 && memcmp (trun
, cp
, len
) == 0)
430 trun
+= system_dirs_len
[idx
] + 1;
435 /* Simply drop this directory. */
439 /* See if this directory is already known. */
440 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
441 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
446 /* It is available, see whether it's on our own list. */
448 for (cnt
= 0; cnt
< nelems
; ++cnt
)
449 if (result
[cnt
] == dirp
)
453 result
[nelems
++] = dirp
;
458 enum r_dir_status init_val
;
459 size_t where_len
= where
? strlen (where
) + 1 : 0;
461 /* It's a new directory. Create an entry and add it. */
462 dirp
= (struct r_search_path_elem
*)
463 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
464 + where_len
+ len
+ 1);
466 _dl_signal_error (ENOMEM
, NULL
, NULL
,
467 N_("cannot create cache for search path"));
469 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
470 + ncapstr
* sizeof (enum r_dir_status
));
471 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
472 dirp
->dirnamelen
= len
;
474 if (len
> max_dirnamelen
)
475 max_dirnamelen
= len
;
477 /* We have to make sure all the relative directories are
478 never ignored. The current directory might change and
479 all our saved information would be void. */
480 init_val
= cp
[0] != '/' ? existing
: unknown
;
481 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
482 dirp
->status
[cnt
] = init_val
;
485 if (__builtin_expect (where
!= NULL
, 1))
486 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
487 + (ncapstr
* sizeof (enum r_dir_status
)),
492 dirp
->next
= GL(dl_all_dirs
);
493 GL(dl_all_dirs
) = dirp
;
495 /* Put it in the result array. */
496 result
[nelems
++] = dirp
;
500 /* Terminate the array. */
501 result
[nelems
] = NULL
;
509 decompose_rpath (struct r_search_path_struct
*sps
,
510 const char *rpath
, struct link_map
*l
, const char *what
)
512 /* Make a copy we can work with. */
513 const char *where
= l
->l_name
;
516 struct r_search_path_elem
**result
;
518 /* Initialize to please the compiler. */
519 const char *errstring
= NULL
;
521 /* First see whether we must forget the RUNPATH and RPATH from this
523 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
524 && !INTUSE(__libc_enable_secure
))
526 const char *inhp
= GLRO(dl_inhibit_rpath
);
530 const char *wp
= where
;
532 while (*inhp
== *wp
&& *wp
!= '\0')
538 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
540 /* This object is on the list of objects for which the
541 RUNPATH and RPATH must not be used. */
542 result
= calloc (1, sizeof *result
);
546 errstring
= N_("cannot create cache for search path");
548 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
557 while (*inhp
!= '\0')
561 while (*inhp
!= '\0');
564 /* Make a writable copy. At the same time expand possible dynamic
566 copy
= expand_dynamic_string_token (l
, rpath
);
569 errstring
= N_("cannot create RUNPATH/RPATH copy");
573 /* Count the number of necessary elements in the result array. */
575 for (cp
= copy
; *cp
!= '\0'; ++cp
)
579 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
580 number of necessary entries. */
581 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
584 goto signal_error_cache
;
586 fillin_rpath (copy
, result
, ":", 0, what
, where
);
588 /* Free the copied RPATH string. `fillin_rpath' make own copies if
593 /* The caller will change this value if we haven't used a real malloc. */
597 /* Make sure cached path information is stored in *SP
598 and return true if there are any paths to search there. */
600 cache_rpath (struct link_map
*l
,
601 struct r_search_path_struct
*sp
,
605 if (sp
->dirs
== (void *) -1)
608 if (sp
->dirs
!= NULL
)
611 if (l
->l_info
[tag
] == NULL
)
613 /* There is no path. */
614 sp
->dirs
= (void *) -1;
618 /* Make sure the cache information is available. */
619 decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
620 + l
->l_info
[tag
]->d_un
.d_val
),
628 _dl_init_paths (const char *llp
)
632 struct r_search_path_elem
*pelem
, **aelem
;
637 /* Initialize to please the compiler. */
638 const char *errstring
= NULL
;
640 /* Fill in the information about the application's RPATH and the
641 directories addressed by the LD_LIBRARY_PATH environment variable. */
643 /* Get the capabilities. */
644 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
645 &ncapstr
, &max_capstrlen
);
647 /* First set up the rest of the default search directory entries. */
648 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
649 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
650 if (rtld_search_dirs
.dirs
== NULL
)
652 errstring
= N_("cannot create search path array");
654 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
657 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
658 + ncapstr
* sizeof (enum r_dir_status
))
659 / sizeof (struct r_search_path_elem
));
661 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
662 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
663 * round_size
* sizeof (struct r_search_path_elem
));
664 if (rtld_search_dirs
.dirs
[0] == NULL
)
666 errstring
= N_("cannot create cache for search path");
670 rtld_search_dirs
.malloced
= 0;
671 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
681 pelem
->what
= "system search path";
684 pelem
->dirname
= strp
;
685 pelem
->dirnamelen
= system_dirs_len
[idx
];
686 strp
+= system_dirs_len
[idx
] + 1;
688 /* System paths must be absolute. */
689 assert (pelem
->dirname
[0] == '/');
690 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
691 pelem
->status
[cnt
] = unknown
;
693 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
697 while (idx
< nsystem_dirs_len
);
699 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
703 /* This points to the map of the main object. */
704 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
707 assert (l
->l_type
!= lt_loaded
);
709 if (l
->l_info
[DT_RUNPATH
])
711 /* Allocate room for the search path and fill in information
713 decompose_rpath (&l
->l_runpath_dirs
,
714 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
715 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
718 /* The RPATH is ignored. */
719 l
->l_rpath_dirs
.dirs
= (void *) -1;
723 l
->l_runpath_dirs
.dirs
= (void *) -1;
725 if (l
->l_info
[DT_RPATH
])
727 /* Allocate room for the search path and fill in information
729 decompose_rpath (&l
->l_rpath_dirs
,
730 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
731 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
733 l
->l_rpath_dirs
.malloced
= 0;
736 l
->l_rpath_dirs
.dirs
= (void *) -1;
741 if (llp
!= NULL
&& *llp
!= '\0')
744 const char *cp
= llp
;
745 char *llp_tmp
= strdupa (llp
);
747 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
752 if (*cp
== ':' || *cp
== ';')
757 env_path_list
.dirs
= (struct r_search_path_elem
**)
758 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
759 if (env_path_list
.dirs
== NULL
)
761 errstring
= N_("cannot create cache for search path");
765 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
766 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
769 if (env_path_list
.dirs
[0] == NULL
)
771 free (env_path_list
.dirs
);
772 env_path_list
.dirs
= (void *) -1;
775 env_path_list
.malloced
= 0;
778 env_path_list
.dirs
= (void *) -1;
780 /* Remember the last search directory added at startup. */
781 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
786 __attribute__ ((noreturn
, noinline
))
787 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
790 /* The file might already be closed. */
795 /* Remove the stillborn object from the list and free it. */
796 assert (l
->l_next
== NULL
);
797 if (l
->l_prev
== NULL
)
798 /* No other module loaded. This happens only in the static library,
799 or in rtld under --verify. */
800 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
802 l
->l_prev
->l_next
= NULL
;
803 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
807 _dl_signal_error (code
, name
, NULL
, msg
);
811 /* Map in the shared object NAME, actually located in REALNAME, and already
814 #ifndef EXTERNAL_MAP_FROM_FD
818 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
819 char *realname
, struct link_map
*loader
, int l_type
,
820 int mode
, void **stack_endp
, Lmid_t nsid
)
822 struct link_map
*l
= NULL
;
823 const ElfW(Ehdr
) *header
;
824 const ElfW(Phdr
) *phdr
;
825 const ElfW(Phdr
) *ph
;
829 /* Initialize to keep the compiler happy. */
830 const char *errstring
= NULL
;
832 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
833 bool make_consistent
= false;
835 /* Get file information. */
836 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
838 errstring
= N_("cannot stat shared object");
844 r
->r_state
= RT_CONSISTENT
;
848 lose (errval
, fd
, name
, realname
, l
, errstring
);
851 /* Look again to see if the real name matched another already loaded. */
852 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
853 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
855 /* The object is already loaded.
856 Just bump its reference count and return it. */
859 /* If the name is not in the list of names for this object add
862 add_name_to_object (l
, name
);
868 /* When loading into a namespace other than the base one we must
869 avoid loading ld.so since there can only be one copy. Ever. */
870 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
871 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
872 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
873 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
875 /* This is indeed ld.so. Create a new link_map which refers to
876 the real one for almost everything. */
877 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
881 /* Refer to the real descriptor. */
882 l
->l_real
= &GL(dl_rtld_map
);
884 /* No need to bump the refcount of the real object, ld.so will
885 never be unloaded. */
892 if (mode
& RTLD_NOLOAD
)
893 /* We are not supposed to load the object unless it is already
894 loaded. So return now. */
897 /* Print debugging message. */
898 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
899 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
901 /* This is the ELF header. We read it in `open_verify'. */
902 header
= (void *) fbp
->buf
;
906 if (_dl_zerofd
== -1)
908 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
909 if (_dl_zerofd
== -1)
912 _dl_signal_error (errno
, NULL
, NULL
,
913 N_("cannot open zero fill device"));
918 /* Signal that we are going to add new objects. */
919 if (r
->r_state
== RT_CONSISTENT
)
922 /* Auditing checkpoint: we are going to add new objects. */
923 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
925 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
926 /* Do not call the functions for any auditing object. */
927 if (head
->l_auditing
== 0)
929 struct audit_ifaces
*afct
= GLRO(dl_audit
);
930 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
932 if (afct
->activity
!= NULL
)
933 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
941 /* Notify the debugger we have added some objects. We need to
942 call _dl_debug_initialize in a static program in case dynamic
943 linking has not been used before. */
946 make_consistent
= true;
949 assert (r
->r_state
== RT_ADD
);
951 /* Enter the new object in the list of loaded objects. */
952 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
953 if (__builtin_expect (l
== NULL
, 0))
958 errstring
= N_("cannot create shared object descriptor");
959 goto call_lose_errno
;
962 /* Extract the remaining details we need from the ELF header
963 and then read in the program header table. */
964 l
->l_entry
= header
->e_entry
;
965 type
= header
->e_type
;
966 l
->l_phnum
= header
->e_phnum
;
968 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
969 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
970 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
973 phdr
= alloca (maplength
);
974 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
975 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
977 errstring
= N_("cannot read file data");
978 goto call_lose_errno
;
982 /* Presumed absent PT_GNU_STACK. */
983 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
986 /* Scan the program header table, collecting its load commands. */
989 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
992 } loadcmds
[l
->l_phnum
], *c
;
993 size_t nloadcmds
= 0;
994 bool has_holes
= false;
996 /* The struct is initialized to zero so this is not necessary:
1000 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1003 /* These entries tell us where to find things once the file's
1004 segments are mapped in. We record the addresses it says
1005 verbatim, and later correct for the run-time load address. */
1007 l
->l_ld
= (void *) ph
->p_vaddr
;
1008 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1012 l
->l_phdr
= (void *) ph
->p_vaddr
;
1016 /* A load command tells us to map in part of the file.
1017 We record the load commands and process them all later. */
1018 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1021 errstring
= N_("ELF load command alignment not page-aligned");
1024 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1025 & (ph
->p_align
- 1)) != 0, 0))
1028 = N_("ELF load command address/offset not properly aligned");
1032 c
= &loadcmds
[nloadcmds
++];
1033 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1034 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1035 & ~(GLRO(dl_pagesize
) - 1));
1036 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1037 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1038 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1040 /* Determine whether there is a gap between the last segment
1042 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1045 /* Optimize a common case. */
1046 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1047 c
->prot
= (PF_TO_PROT
1048 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1051 if (ph
->p_flags
& PF_R
)
1052 c
->prot
|= PROT_READ
;
1053 if (ph
->p_flags
& PF_W
)
1054 c
->prot
|= PROT_WRITE
;
1055 if (ph
->p_flags
& PF_X
)
1056 c
->prot
|= PROT_EXEC
;
1062 if (ph
->p_memsz
== 0)
1063 /* Nothing to do for an empty segment. */
1066 l
->l_tls_blocksize
= ph
->p_memsz
;
1067 l
->l_tls_align
= ph
->p_align
;
1068 if (ph
->p_align
== 0)
1069 l
->l_tls_firstbyte_offset
= 0;
1071 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1072 l
->l_tls_initimage_size
= ph
->p_filesz
;
1073 /* Since we don't know the load address yet only store the
1074 offset. We will adjust it later. */
1075 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1077 /* If not loading the initial set of shared libraries,
1078 check whether we should permit loading a TLS segment. */
1079 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1080 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1081 not set up TLS data structures, so don't use them now. */
1082 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1084 /* Assign the next available module ID. */
1085 l
->l_tls_modid
= _dl_next_tls_modid ();
1090 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1091 /* We are loading the executable itself when the dynamic linker
1092 was executed directly. The setup will happen later. */
1095 /* In a static binary there is no way to tell if we dynamically
1096 loaded libpthread. */
1097 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1100 /* We have not yet loaded libpthread.
1101 We can do the TLS setup right now! */
1105 /* The first call allocates TLS bookkeeping data structures.
1106 Then we allocate the TCB for the initial thread. */
1107 if (__builtin_expect (_dl_tls_setup (), 0)
1108 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1113 cannot allocate TLS data structures for initial thread");
1117 /* Now we install the TCB in the thread register. */
1118 errstring
= TLS_INIT_TP (tcb
, 0);
1119 if (__builtin_expect (errstring
== NULL
, 1))
1121 /* Now we are all good. */
1122 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1126 /* The kernel is too old or somesuch. */
1128 _dl_deallocate_tls (tcb
, 1);
1133 /* Uh-oh, the binary expects TLS support but we cannot
1136 errstring
= N_("cannot handle TLS data");
1141 stack_flags
= ph
->p_flags
;
1145 l
->l_relro_addr
= ph
->p_vaddr
;
1146 l
->l_relro_size
= ph
->p_memsz
;
1150 if (__builtin_expect (nloadcmds
== 0, 0))
1152 /* This only happens for a bogus object that will be caught with
1153 another error below. But we don't want to go through the
1154 calculations below using NLOADCMDS - 1. */
1155 errstring
= N_("object file has no loadable segments");
1159 /* Now process the load commands and map segments into memory. */
1162 /* Length of the sections to be loaded. */
1163 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1165 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1167 /* This is a position-independent shared object. We can let the
1168 kernel map it anywhere it likes, but we must have space for all
1169 the segments in their specified positions relative to the first.
1170 So we map the first segment without MAP_FIXED, but with its
1171 extent increased to cover all the segments. Then we remove
1172 access from excess portion, and there is known sufficient space
1173 there to remap from the later segments.
1175 As a refinement, sometimes we have an address that we would
1176 prefer to map such objects at; but this is only a preference,
1177 the OS can do whatever it likes. */
1179 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1180 c
->mapstart
& GLRO(dl_use_load_bias
))
1181 - MAP_BASE_ADDR (l
));
1183 /* Remember which part of the address space this object uses. */
1184 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1188 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1191 errstring
= N_("failed to map segment from shared object");
1192 goto call_lose_errno
;
1195 l
->l_map_end
= l
->l_map_start
+ maplength
;
1196 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1199 /* Change protection on the excess portion to disallow all access;
1200 the portions we do not remap later will be inaccessible as if
1201 unallocated. Then jump into the normal segment-mapping loop to
1202 handle the portion of the segment past the end of the file
1204 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1205 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1211 /* This object is loaded at a fixed address. This must never
1212 happen for objects loaded with dlopen(). */
1213 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1215 errstring
= N_("cannot dynamically load executable");
1219 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1221 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1224 /* Remember which part of the address space this object uses. */
1225 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1226 l
->l_map_end
= l
->l_map_start
+ maplength
;
1228 while (c
< &loadcmds
[nloadcmds
])
1230 if (c
->mapend
> c
->mapstart
1231 /* Map the segment contents from the file. */
1232 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1233 c
->mapend
- c
->mapstart
, c
->prot
,
1234 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1240 if (c
->prot
& PROT_EXEC
)
1241 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1244 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1245 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1246 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1247 /* Found the program header in this segment. */
1248 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1250 if (c
->allocend
> c
->dataend
)
1252 /* Extra zero pages should appear at the end of this segment,
1253 after the data mapped from the file. */
1254 ElfW(Addr
) zero
, zeroend
, zeropage
;
1256 zero
= l
->l_addr
+ c
->dataend
;
1257 zeroend
= l
->l_addr
+ c
->allocend
;
1258 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1259 & ~(GLRO(dl_pagesize
) - 1));
1261 if (zeroend
< zeropage
)
1262 /* All the extra data is in the last page of the segment.
1263 We can just zero it. */
1266 if (zeropage
> zero
)
1268 /* Zero the final part of the last page of the segment. */
1269 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1272 if (__mprotect ((caddr_t
) (zero
1273 & ~(GLRO(dl_pagesize
) - 1)),
1274 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1276 errstring
= N_("cannot change memory protections");
1277 goto call_lose_errno
;
1280 memset ((void *) zero
, '\0', zeropage
- zero
);
1281 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1282 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1283 GLRO(dl_pagesize
), c
->prot
);
1286 if (zeroend
> zeropage
)
1288 /* Map the remaining zero pages in from the zero fill FD. */
1290 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1291 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1293 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1295 errstring
= N_("cannot map zero-fill pages");
1296 goto call_lose_errno
;
1307 if (__builtin_expect (type
== ET_DYN
, 0))
1309 errstring
= N_("object file has no dynamic section");
1314 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1316 elf_get_dynamic_info (l
, NULL
);
1318 /* Make sure we are not dlopen'ing an object that has the
1319 DF_1_NOOPEN flag set. */
1320 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1321 && (mode
& __RTLD_DLOPEN
))
1323 /* We are not supposed to load this object. Free all resources. */
1324 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1326 if (!l
->l_libname
->dont_free
)
1327 free (l
->l_libname
);
1329 if (l
->l_phdr_allocated
)
1330 free ((void *) l
->l_phdr
);
1332 errstring
= N_("shared object cannot be dlopen()ed");
1336 if (l
->l_phdr
== NULL
)
1338 /* The program header is not contained in any of the segments.
1339 We have to allocate memory ourself and copy it over from out
1341 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1342 * sizeof (ElfW(Phdr
)));
1345 errstring
= N_("cannot allocate memory for program header");
1346 goto call_lose_errno
;
1349 l
->l_phdr
= memcpy (newp
, phdr
,
1350 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1351 l
->l_phdr_allocated
= 1;
1354 /* Adjust the PT_PHDR value by the runtime load address. */
1355 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1357 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1359 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1362 errstring
= N_("invalid caller");
1366 /* The stack is presently not executable, but this module
1367 requires that it be executable. We must change the
1368 protection of the variable which contains the flags used in
1369 the mprotect calls. */
1370 #if defined HAVE_Z_RELRO && defined SHARED
1371 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1373 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1374 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1376 struct link_map
*const m
= &GL(dl_rtld_map
);
1377 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1379 & -GLRO(dl_pagesize
));
1380 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1382 /* The variable lies in the region protected by RELRO. */
1383 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1384 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1385 __mprotect ((void *) p
, s
, PROT_READ
);
1388 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1392 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1394 #ifdef check_consistency
1395 check_consistency ();
1398 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1402 cannot enable executable stack as shared object requires");
1408 /* Adjust the address of the TLS initialization image. */
1409 if (l
->l_tls_initimage
!= NULL
)
1410 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1413 /* We are done mapping in the file. We no longer need the descriptor. */
1414 if (__builtin_expect (__close (fd
) != 0, 0))
1416 errstring
= N_("cannot close file descriptor");
1417 goto call_lose_errno
;
1419 /* Signal that we closed the file. */
1422 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1423 l
->l_type
= lt_executable
;
1425 l
->l_entry
+= l
->l_addr
;
1427 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1428 _dl_debug_printf ("\
1429 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1430 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1431 (int) sizeof (void *) * 2,
1432 (unsigned long int) l
->l_ld
,
1433 (int) sizeof (void *) * 2,
1434 (unsigned long int) l
->l_addr
,
1435 (int) sizeof (void *) * 2, maplength
,
1436 (int) sizeof (void *) * 2,
1437 (unsigned long int) l
->l_entry
,
1438 (int) sizeof (void *) * 2,
1439 (unsigned long int) l
->l_phdr
,
1440 (int) sizeof (void *) * 2, l
->l_phnum
);
1442 /* Set up the symbol hash table. */
1445 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1446 have to do this for the main map. */
1447 if ((mode
& RTLD_DEEPBIND
) == 0
1448 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1449 && &l
->l_searchlist
!= l
->l_scope
[0])
1451 /* Create an appropriate searchlist. It contains only this map.
1452 This is the definition of DT_SYMBOLIC in SysVr4. */
1453 l
->l_symbolic_searchlist
.r_list
=
1454 (struct link_map
**) malloc (sizeof (struct link_map
*));
1456 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1458 errstring
= N_("cannot create searchlist");
1459 goto call_lose_errno
;
1462 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1463 l
->l_symbolic_searchlist
.r_nlist
= 1;
1465 /* Now move the existing entries one back. */
1466 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1467 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1469 /* Now add the new entry. */
1470 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1473 /* Remember whether this object must be initialized first. */
1474 if (l
->l_flags_1
& DF_1_INITFIRST
)
1475 GL(dl_initfirst
) = l
;
1477 /* Finally the file information. */
1478 l
->l_dev
= st
.st_dev
;
1479 l
->l_ino
= st
.st_ino
;
1481 /* When we profile the SONAME might be needed for something else but
1482 loading. Add it right away. */
1483 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1484 && l
->l_info
[DT_SONAME
] != NULL
)
1485 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1486 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1489 /* Auditing checkpoint: we have a new object. */
1490 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1491 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1493 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1494 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1496 if (afct
->objopen
!= NULL
)
1498 l
->l_audit
[cnt
].bindflags
1499 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1501 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1512 /* Print search path. */
1514 print_search_path (struct r_search_path_elem
**list
,
1515 const char *what
, const char *name
)
1517 char buf
[max_dirnamelen
+ max_capstrlen
];
1520 _dl_debug_printf (" search path=");
1522 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1524 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1527 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1528 if ((*list
)->status
[cnt
] != nonexisting
)
1530 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1531 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1536 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1544 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1545 name
[0] ? name
: rtld_progname
);
1547 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1550 /* Open a file and verify it is an ELF file for this architecture. We
1551 ignore only ELF files for other architectures. Non-ELF files and
1552 ELF files with different header information cause fatal errors since
1553 this could mean there is something wrong in the installation and the
1554 user might want to know about this. */
1556 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1557 int whatcode
, bool *found_other_class
)
1559 /* This is the expected ELF header. */
1560 #define ELF32_CLASS ELFCLASS32
1561 #define ELF64_CLASS ELFCLASS64
1562 #ifndef VALID_ELF_HEADER
1563 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1564 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1565 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1567 static const unsigned char expected
[EI_PAD
] =
1569 [EI_MAG0
] = ELFMAG0
,
1570 [EI_MAG1
] = ELFMAG1
,
1571 [EI_MAG2
] = ELFMAG2
,
1572 [EI_MAG3
] = ELFMAG3
,
1573 [EI_CLASS
] = ELFW(CLASS
),
1574 [EI_DATA
] = byteorder
,
1575 [EI_VERSION
] = EV_CURRENT
,
1576 [EI_OSABI
] = ELFOSABI_SYSV
,
1581 ElfW(Word
) vendorlen
;
1585 } expected_note
= { 4, 16, 1, "GNU" };
1586 /* Initialize it to make the compiler happy. */
1587 const char *errstring
= NULL
;
1591 /* Give the auditing libraries a chance. */
1592 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1593 && loader
->l_auditing
== 0)
1595 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1596 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1598 if (afct
->objsearch
!= NULL
)
1600 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1603 /* Ignore the path. */
1612 /* Open the file. We always open files read-only. */
1613 int fd
= __open (name
, O_RDONLY
);
1617 ElfW(Phdr
) *phdr
, *ph
;
1618 ElfW(Word
) *abi_note
, abi_note_buf
[8];
1619 unsigned int osversion
;
1622 /* We successfully openened the file. Now verify it is a file
1625 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1627 /* This is where the ELF header is loaded. */
1628 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1629 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1631 /* Now run the tests. */
1632 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1635 errstring
= (errval
== 0
1636 ? N_("file too short") : N_("cannot read file data"));
1638 lose (errval
, fd
, name
, NULL
, NULL
, errstring
);
1641 /* See whether the ELF header is what we expect. */
1642 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1645 /* Something is wrong. */
1646 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1647 #if BYTE_ORDER == LITTLE_ENDIAN
1648 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1649 (ELFMAG1
<< (EI_MAG1
* 8)) |
1650 (ELFMAG2
<< (EI_MAG2
* 8)) |
1651 (ELFMAG3
<< (EI_MAG3
* 8)))
1653 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1654 (ELFMAG1
<< (EI_MAG2
* 8)) |
1655 (ELFMAG2
<< (EI_MAG1
* 8)) |
1656 (ELFMAG3
<< (EI_MAG0
* 8)))
1659 errstring
= N_("invalid ELF header");
1660 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1662 /* This is not a fatal error. On architectures where
1663 32-bit and 64-bit binaries can be run this might
1665 *found_other_class
= true;
1668 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1670 if (BYTE_ORDER
== BIG_ENDIAN
)
1671 errstring
= N_("ELF file data encoding not big-endian");
1673 errstring
= N_("ELF file data encoding not little-endian");
1675 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1677 = N_("ELF file version ident does not match current one");
1678 /* XXX We should be able so set system specific versions which are
1680 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1681 errstring
= N_("ELF file OS ABI invalid");
1682 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1683 errstring
= N_("ELF file ABI version invalid");
1685 /* Otherwise we don't know what went wrong. */
1686 errstring
= N_("internal error");
1691 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1693 errstring
= N_("ELF file version does not match current one");
1696 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1698 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1699 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1701 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1704 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1705 != sizeof (ElfW(Phdr
)))
1707 errstring
= N_("ELF file's phentsize not the expected size");
1711 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1712 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1713 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1716 phdr
= alloca (maplength
);
1717 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1718 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1722 errstring
= N_("cannot read file data");
1727 /* Check .note.ABI-tag if present. */
1728 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1729 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
== 32 && ph
->p_align
>= 4)
1731 if (ph
->p_offset
+ 32 <= (size_t) fbp
->len
)
1732 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1735 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1736 if (__libc_read (fd
, (void *) abi_note_buf
, 32) != 32)
1739 abi_note
= abi_note_buf
;
1742 if (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1745 osversion
= (abi_note
[5] & 0xff) * 65536
1746 + (abi_note
[6] & 0xff) * 256
1747 + (abi_note
[7] & 0xff);
1748 if (abi_note
[4] != __ABI_TAG_OS
1749 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1753 __set_errno (ENOENT
);
1764 /* Try to open NAME in one of the directories in *DIRSP.
1765 Return the fd, or -1. If successful, fill in *REALNAME
1766 with the malloc'd full directory name. If it turns out
1767 that none of the directories in *DIRSP exists, *DIRSP is
1768 replaced with (void *) -1, and the old value is free()d
1769 if MAY_FREE_DIRS is true. */
1772 open_path (const char *name
, size_t namelen
, int preloaded
,
1773 struct r_search_path_struct
*sps
, char **realname
,
1774 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1775 bool *found_other_class
)
1777 struct r_search_path_elem
**dirs
= sps
->dirs
;
1780 const char *current_what
= NULL
;
1783 if (__builtin_expect (dirs
== NULL
, 0))
1784 /* We're called before _dl_init_paths when loading the main executable
1785 given on the command line when rtld is run directly. */
1788 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1791 struct r_search_path_elem
*this_dir
= *dirs
;
1798 /* If we are debugging the search for libraries print the path
1799 now if it hasn't happened now. */
1800 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1801 && current_what
!= this_dir
->what
)
1803 current_what
= this_dir
->what
;
1804 print_search_path (dirs
, current_what
, this_dir
->where
);
1807 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1808 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1810 /* Skip this directory if we know it does not exist. */
1811 if (this_dir
->status
[cnt
] == nonexisting
)
1815 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1820 /* Print name we try if this is wanted. */
1821 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1822 _dl_debug_printf (" trying file=%s\n", buf
);
1824 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
);
1825 if (this_dir
->status
[cnt
] == unknown
)
1828 this_dir
->status
[cnt
] = existing
;
1829 /* Do not update the directory information when loading
1830 auditing code. We must try to disturb the program as
1831 little as possible. */
1832 else if (loader
== NULL
1833 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_audit
== 0)
1835 /* We failed to open machine dependent library. Let's
1836 test whether there is any directory at all. */
1839 buf
[buflen
- namelen
- 1] = '\0';
1841 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1842 || ! S_ISDIR (st
.st_mode
))
1843 /* The directory does not exist or it is no directory. */
1844 this_dir
->status
[cnt
] = nonexisting
;
1846 this_dir
->status
[cnt
] = existing
;
1850 /* Remember whether we found any existing directory. */
1851 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1853 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1854 && INTUSE(__libc_enable_secure
))
1856 /* This is an extra security effort to make sure nobody can
1857 preload broken shared objects which are in the trusted
1858 directories and so exploit the bugs. */
1861 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1862 || (st
.st_mode
& S_ISUID
) == 0)
1864 /* The shared object cannot be tested for being SUID
1865 or this bit is not set. In this case we must not
1869 /* We simply ignore the file, signal this by setting
1870 the error value which would have been set by `open'. */
1878 *realname
= (char *) malloc (buflen
);
1879 if (*realname
!= NULL
)
1881 memcpy (*realname
, buf
, buflen
);
1886 /* No memory for the name, we certainly won't be able
1887 to load and link it. */
1892 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1893 /* The file exists and is readable, but something went wrong. */
1896 /* Remember whether we found anything. */
1899 while (*++dirs
!= NULL
);
1901 /* Remove the whole path if none of the directories exists. */
1902 if (__builtin_expect (! any
, 0))
1904 /* Paths which were allocated using the minimal malloc() in ld.so
1905 must not be freed using the general free() in libc. */
1909 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1911 if (sps
!= &rtld_search_dirs
)
1913 sps
->dirs
= (void *) -1;
1919 /* Map in the shared object file NAME. */
1923 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1924 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1933 assert (nsid
< DL_NNS
);
1935 /* Look for this name among those already loaded. */
1936 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1938 /* If the requested name matches the soname of a loaded object,
1939 use that object. Elide this check for names that have not
1941 if (__builtin_expect (l
->l_faked
, 0) != 0
1942 || __builtin_expect (l
->l_removed
, 0) != 0)
1944 if (!_dl_name_match_p (name
, l
))
1948 if (__builtin_expect (l
->l_soname_added
, 1)
1949 || l
->l_info
[DT_SONAME
] == NULL
)
1952 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1953 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1954 if (strcmp (name
, soname
) != 0)
1957 /* We have a match on a new name -- cache it. */
1958 add_name_to_object (l
, soname
);
1959 l
->l_soname_added
= 1;
1962 /* We have a match. */
1966 /* Display information if we are debugging. */
1967 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
1969 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
1971 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
1974 /* Give the auditing libraries a chance to change the name before we
1976 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1977 && (loader
== NULL
|| loader
->l_auditing
== 0))
1979 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1980 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1982 if (afct
->objsearch
!= NULL
)
1984 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1988 /* Do not try anything further. */
1999 /* Will be true if we found a DSO which is of the other ELF class. */
2000 bool found_other_class
= false;
2002 if (strchr (name
, '/') == NULL
)
2004 /* Search for NAME in several places. */
2006 size_t namelen
= strlen (name
) + 1;
2008 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2009 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2013 /* When the object has the RUNPATH information we don't use any
2015 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2017 /* First try the DT_RPATH of the dependent object that caused NAME
2018 to be loaded. Then that object's dependent, and on up. */
2019 for (l
= loader
; fd
== -1 && l
; l
= l
->l_loader
)
2020 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2021 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2022 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2023 &found_other_class
);
2025 /* If dynamically linked, try the DT_RPATH of the executable
2026 itself. NB: we do this for lookups in any namespace. */
2029 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2030 if (l
&& l
->l_type
!= lt_loaded
&& l
!= loader
2031 && cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2032 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2033 &realname
, &fb
, loader
?: l
, LA_SER_RUNPATH
,
2034 &found_other_class
);
2038 /* Try the LD_LIBRARY_PATH environment variable. */
2039 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2040 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2042 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2043 LA_SER_LIBPATH
, &found_other_class
);
2045 /* Look at the RUNPATH information for this binary. */
2046 if (fd
== -1 && loader
!= NULL
2047 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2048 DT_RUNPATH
, "RUNPATH"))
2049 fd
= open_path (name
, namelen
, preloaded
,
2050 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2051 LA_SER_RUNPATH
, &found_other_class
);
2054 && (__builtin_expect (! preloaded
, 1)
2055 || ! INTUSE(__libc_enable_secure
)))
2057 /* Check the list of libraries in the file /etc/ld.so.cache,
2058 for compatibility with Linux's ldconfig program. */
2059 const char *cached
= _dl_load_cache_lookup (name
);
2064 // XXX Correct to unconditionally default to namespace 0?
2065 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2070 /* If the loader has the DF_1_NODEFLIB flag set we must not
2071 use a cache entry from any of these directories. */
2074 /* 'l' is always != NULL for dynamically linked objects. */
2077 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2079 const char *dirp
= system_dirs
;
2080 unsigned int cnt
= 0;
2084 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2086 /* The prefix matches. Don't use the entry. */
2091 dirp
+= system_dirs_len
[cnt
] + 1;
2094 while (cnt
< nsystem_dirs_len
);
2099 fd
= open_verify (cached
,
2100 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2101 LA_SER_CONFIG
, &found_other_class
);
2102 if (__builtin_expect (fd
!= -1, 1))
2104 realname
= local_strdup (cached
);
2105 if (realname
== NULL
)
2115 /* Finally, try the default path. */
2117 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2118 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2119 && rtld_search_dirs
.dirs
!= (void *) -1)
2120 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2121 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2123 /* Add another newline when we are tracing the library loading. */
2124 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2125 _dl_debug_printf ("\n");
2129 /* The path may contain dynamic string tokens. */
2131 ? expand_dynamic_string_token (loader
, name
)
2132 : local_strdup (name
));
2133 if (realname
== NULL
)
2137 fd
= open_verify (realname
, &fb
,
2138 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2139 &found_other_class
);
2140 if (__builtin_expect (fd
, 0) == -1)
2148 /* In case the LOADER information has only been provided to get to
2149 the appropriate RUNPATH/RPATH information we do not need it
2151 if (mode
& __RTLD_CALLMAP
)
2154 if (__builtin_expect (fd
, 0) == -1)
2157 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2159 /* We haven't found an appropriate library. But since we
2160 are only interested in the list of libraries this isn't
2161 so severe. Fake an entry with all the information we
2163 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2165 /* Enter the new object in the list of loaded objects. */
2166 if ((name_copy
= local_strdup (name
)) == NULL
2167 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2168 mode
, nsid
)) == NULL
)
2169 _dl_signal_error (ENOMEM
, name
, NULL
,
2170 N_("cannot create shared object descriptor"));
2171 /* Signal that this is a faked entry. */
2173 /* Since the descriptor is initialized with zero we do not
2175 l->l_reserved = 0; */
2176 l
->l_buckets
= &dummy_bucket
;
2182 else if (found_other_class
)
2183 _dl_signal_error (0, name
, NULL
,
2184 ELFW(CLASS
) == ELFCLASS32
2185 ? N_("wrong ELF class: ELFCLASS64")
2186 : N_("wrong ELF class: ELFCLASS32"));
2188 _dl_signal_error (errno
, name
, NULL
,
2189 N_("cannot open shared object file"));
2192 void *stack_end
= __libc_stack_end
;
2193 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2200 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2208 unsigned int idx
= 0;
2209 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2210 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2211 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2213 if (sps
->dirs
!= (void *) -1)
2215 struct r_search_path_elem
**dirs
= sps
->dirs
;
2218 const struct r_search_path_elem
*const r
= *dirs
++;
2222 si
->dls_size
+= r
->dirnamelen
;
2226 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2227 sp
->dls_name
= allocptr
;
2228 allocptr
= __mempcpy (allocptr
,
2229 r
->dirname
, r
->dirnamelen
- 1);
2231 sp
->dls_flags
= flags
;
2234 while (*dirs
!= NULL
);
2238 /* When the object has the RUNPATH information we don't use any RPATHs. */
2239 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2241 /* First try the DT_RPATH of the dependent object that caused NAME
2242 to be loaded. Then that object's dependent, and on up. */
2244 struct link_map
*l
= loader
;
2247 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2248 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2253 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2254 if (loader
->l_ns
== LM_ID_BASE
)
2256 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2257 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2258 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2259 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2263 /* Try the LD_LIBRARY_PATH environment variable. */
2264 add_path (&env_path_list
, XXX_ENV
);
2266 /* Look at the RUNPATH information for this binary. */
2267 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2268 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2271 Here is where ld.so.cache gets checked, but we don't have
2272 a way to indicate that in the results for Dl_serinfo. */
2274 /* Finally, try the default path. */
2275 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2276 add_path (&rtld_search_dirs
, XXX_default
);
2279 /* Count the struct size before the string area, which we didn't
2280 know before we completed dls_cnt. */
2281 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;