1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2005, 2006, 2007, 2009, 2010 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)
88 /* Handle situations where we have a preferred location in memory for
89 the shared objects. */
90 #ifdef ELF_PREFERRED_ADDRESS_DATA
91 ELF_PREFERRED_ADDRESS_DATA
;
93 #ifndef ELF_PREFERRED_ADDRESS
94 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
96 #ifndef ELF_FIXED_ADDRESS
97 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
101 int __stack_prot attribute_hidden attribute_relro
102 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
104 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
111 /* Type for the buffer we put the ELF header and hopefully the program
112 header. This buffer does not really have to be too large. In most
113 cases the program header follows the ELF header directly. If this
114 is not the case all bets are off and we can make the header
115 arbitrarily large and still won't get it read. This means the only
116 question is how large are the ELF and program header combined. The
117 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
118 bytes long. Each program header entry is again 32 and 56 bytes
119 long respectively. I.e., even with a file which has 10 program
120 header entries we only have to read 372B/624B respectively. Add to
121 this a bit of margin for program notes and reading 512B and 832B
122 for 32-bit and 64-bit files respecitvely is enough. If this
123 heuristic should really fail for some file the code in
124 `_dl_map_object_from_fd' knows how to recover. */
129 # define FILEBUF_SIZE 512
131 # define FILEBUF_SIZE 832
133 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
136 /* This is the decomposed LD_LIBRARY_PATH search path. */
137 static struct r_search_path_struct env_path_list attribute_relro
;
139 /* List of the hardware capabilities we might end up using. */
140 static const struct r_strlenpair
*capstr attribute_relro
;
141 static size_t ncapstr attribute_relro
;
142 static size_t max_capstrlen attribute_relro
;
145 /* Get the generated information about the trusted directories. */
146 #include "trusted-dirs.h"
148 static const char system_dirs
[] = SYSTEM_DIRS
;
149 static const size_t system_dirs_len
[] =
153 #define nsystem_dirs_len \
154 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
157 /* Local version of `strdup' function. */
159 local_strdup (const char *s
)
161 size_t len
= strlen (s
) + 1;
162 void *new = malloc (len
);
167 return (char *) memcpy (new, s
, len
);
172 is_dst (const char *start
, const char *name
, const char *str
,
173 int is_path
, int secure
)
176 bool is_curly
= false;
185 while (name
[len
] == str
[len
] && name
[len
] != '\0')
190 if (name
[len
] != '}')
193 /* Point again at the beginning of the name. */
195 /* Skip over closing curly brace and adjust for the --name. */
198 else if (name
[len
] != '\0' && name
[len
] != '/'
199 && (!is_path
|| name
[len
] != ':'))
202 if (__builtin_expect (secure
, 0)
203 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
204 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
212 _dl_dst_count (const char *name
, int is_path
)
214 const char *const start
= name
;
221 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
222 is $ORIGIN alone) and it must always appear first in path. */
224 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
225 INTUSE(__libc_enable_secure
))) != 0
226 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
227 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
230 name
= strchr (name
+ len
, '$');
232 while (name
!= NULL
);
239 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
242 const char *const start
= name
;
243 char *last_elem
, *wp
;
245 /* Now fill the result path. While copying over the string we keep
246 track of the start of the last path element. When we come accross
247 a DST we copy over the value or (if the value is not available)
248 leave the entire path element out. */
249 last_elem
= wp
= result
;
253 if (__builtin_expect (*name
== '$', 0))
255 const char *repl
= NULL
;
259 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
260 INTUSE(__libc_enable_secure
))) != 0)
264 repl
= _dl_get_origin ();
269 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
270 repl
= GLRO(dl_platform
);
271 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
274 if (repl
!= NULL
&& repl
!= (const char *) -1)
276 wp
= __stpcpy (wp
, repl
);
281 /* We cannot use this path element, the value of the
282 replacement is unknown. */
285 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
289 /* No DST we recognize. */
295 if (is_path
&& *name
== ':')
299 while (*name
!= '\0');
307 /* Return copy of argument with all recognized dynamic string tokens
308 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
309 might not be possible to determine the path from which the object
310 belonging to the map is loaded. In this case the path element
311 containing $ORIGIN is left out. */
313 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
315 /* We make two runs over the string. First we determine how large the
316 resulting string is and then we copy it over. Since this is no
317 frequently executed operation we are looking here not for performance
318 but rather for code size. */
323 /* Determine the number of DST elements. */
324 cnt
= DL_DST_COUNT (s
, 1);
326 /* If we do not have to replace anything simply copy the string. */
327 if (__builtin_expect (cnt
, 0) == 0)
328 return local_strdup (s
);
330 /* Determine the length of the substituted string. */
331 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
333 /* Allocate the necessary memory. */
334 result
= (char *) malloc (total
+ 1);
338 return _dl_dst_substitute (l
, s
, result
, 1);
342 /* Add `name' to the list of names for a particular shared object.
343 `name' is expected to have been allocated with malloc and will
344 be freed if the shared object already has this name.
345 Returns false if the object already had this name. */
348 add_name_to_object (struct link_map
*l
, const char *name
)
350 struct libname_list
*lnp
, *lastp
;
351 struct libname_list
*newname
;
355 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
356 if (strcmp (name
, lnp
->name
) == 0)
359 name_len
= strlen (name
) + 1;
360 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
363 /* No more memory. */
364 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
367 /* The object should have a libname set from _dl_new_object. */
368 assert (lastp
!= NULL
);
370 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
371 newname
->next
= NULL
;
372 newname
->dont_free
= 0;
373 lastp
->next
= newname
;
376 /* Standard search directories. */
377 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
379 static size_t max_dirnamelen
;
381 static struct r_search_path_elem
**
382 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
383 int check_trusted
, const char *what
, const char *where
)
388 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
390 struct r_search_path_elem
*dirp
;
391 size_t len
= strlen (cp
);
393 /* `strsep' can pass an empty string. This has to be
394 interpreted as `use the current directory'. */
397 static const char curwd
[] = "./";
401 /* Remove trailing slashes (except for "/"). */
402 while (len
> 1 && cp
[len
- 1] == '/')
405 /* Now add one if there is none so far. */
406 if (len
> 0 && cp
[len
- 1] != '/')
409 /* Make sure we don't use untrusted directories if we run SUID. */
410 if (__builtin_expect (check_trusted
, 0))
412 const char *trun
= system_dirs
;
416 /* All trusted directories must be complete names. */
419 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
421 if (len
== system_dirs_len
[idx
]
422 && memcmp (trun
, cp
, len
) == 0)
429 trun
+= system_dirs_len
[idx
] + 1;
434 /* Simply drop this directory. */
438 /* See if this directory is already known. */
439 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
440 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
445 /* It is available, see whether it's on our own list. */
447 for (cnt
= 0; cnt
< nelems
; ++cnt
)
448 if (result
[cnt
] == dirp
)
452 result
[nelems
++] = dirp
;
457 enum r_dir_status init_val
;
458 size_t where_len
= where
? strlen (where
) + 1 : 0;
460 /* It's a new directory. Create an entry and add it. */
461 dirp
= (struct r_search_path_elem
*)
462 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
463 + where_len
+ len
+ 1);
465 _dl_signal_error (ENOMEM
, NULL
, NULL
,
466 N_("cannot create cache for search path"));
468 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
469 + ncapstr
* sizeof (enum r_dir_status
));
470 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
471 dirp
->dirnamelen
= len
;
473 if (len
> max_dirnamelen
)
474 max_dirnamelen
= len
;
476 /* We have to make sure all the relative directories are
477 never ignored. The current directory might change and
478 all our saved information would be void. */
479 init_val
= cp
[0] != '/' ? existing
: unknown
;
480 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
481 dirp
->status
[cnt
] = init_val
;
484 if (__builtin_expect (where
!= NULL
, 1))
485 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
486 + (ncapstr
* sizeof (enum r_dir_status
)),
491 dirp
->next
= GL(dl_all_dirs
);
492 GL(dl_all_dirs
) = dirp
;
494 /* Put it in the result array. */
495 result
[nelems
++] = dirp
;
499 /* Terminate the array. */
500 result
[nelems
] = NULL
;
508 decompose_rpath (struct r_search_path_struct
*sps
,
509 const char *rpath
, struct link_map
*l
, const char *what
)
511 /* Make a copy we can work with. */
512 const char *where
= l
->l_name
;
515 struct r_search_path_elem
**result
;
517 /* Initialize to please the compiler. */
518 const char *errstring
= NULL
;
520 /* First see whether we must forget the RUNPATH and RPATH from this
522 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
523 && !INTUSE(__libc_enable_secure
))
525 const char *inhp
= GLRO(dl_inhibit_rpath
);
529 const char *wp
= where
;
531 while (*inhp
== *wp
&& *wp
!= '\0')
537 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
539 /* This object is on the list of objects for which the
540 RUNPATH and RPATH must not be used. */
541 sps
->dirs
= (void *) -1;
545 while (*inhp
!= '\0')
549 while (*inhp
!= '\0');
552 /* Make a writable copy. At the same time expand possible dynamic
554 copy
= expand_dynamic_string_token (l
, rpath
);
557 errstring
= N_("cannot create RUNPATH/RPATH copy");
561 /* Count the number of necessary elements in the result array. */
563 for (cp
= copy
; *cp
!= '\0'; ++cp
)
567 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
568 number of necessary entries. */
569 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
574 errstring
= N_("cannot create cache for search path");
576 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
579 fillin_rpath (copy
, result
, ":", 0, what
, where
);
581 /* Free the copied RPATH string. `fillin_rpath' make own copies if
586 /* The caller will change this value if we haven't used a real malloc. */
591 /* Make sure cached path information is stored in *SP
592 and return true if there are any paths to search there. */
594 cache_rpath (struct link_map
*l
,
595 struct r_search_path_struct
*sp
,
599 if (sp
->dirs
== (void *) -1)
602 if (sp
->dirs
!= NULL
)
605 if (l
->l_info
[tag
] == NULL
)
607 /* There is no path. */
608 sp
->dirs
= (void *) -1;
612 /* Make sure the cache information is available. */
613 return decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
614 + l
->l_info
[tag
]->d_un
.d_val
),
621 _dl_init_paths (const char *llp
)
625 struct r_search_path_elem
*pelem
, **aelem
;
630 /* Initialize to please the compiler. */
631 const char *errstring
= NULL
;
633 /* Fill in the information about the application's RPATH and the
634 directories addressed by the LD_LIBRARY_PATH environment variable. */
636 /* Get the capabilities. */
637 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
638 &ncapstr
, &max_capstrlen
);
640 /* First set up the rest of the default search directory entries. */
641 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
642 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
643 if (rtld_search_dirs
.dirs
== NULL
)
645 errstring
= N_("cannot create search path array");
647 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
650 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
651 + ncapstr
* sizeof (enum r_dir_status
))
652 / sizeof (struct r_search_path_elem
));
654 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
655 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
656 * round_size
* sizeof (struct r_search_path_elem
));
657 if (rtld_search_dirs
.dirs
[0] == NULL
)
659 errstring
= N_("cannot create cache for search path");
663 rtld_search_dirs
.malloced
= 0;
664 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
674 pelem
->what
= "system search path";
677 pelem
->dirname
= strp
;
678 pelem
->dirnamelen
= system_dirs_len
[idx
];
679 strp
+= system_dirs_len
[idx
] + 1;
681 /* System paths must be absolute. */
682 assert (pelem
->dirname
[0] == '/');
683 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
684 pelem
->status
[cnt
] = unknown
;
686 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
690 while (idx
< nsystem_dirs_len
);
692 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
696 /* This points to the map of the main object. */
697 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
700 assert (l
->l_type
!= lt_loaded
);
702 if (l
->l_info
[DT_RUNPATH
])
704 /* Allocate room for the search path and fill in information
706 decompose_rpath (&l
->l_runpath_dirs
,
707 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
708 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
711 /* The RPATH is ignored. */
712 l
->l_rpath_dirs
.dirs
= (void *) -1;
716 l
->l_runpath_dirs
.dirs
= (void *) -1;
718 if (l
->l_info
[DT_RPATH
])
720 /* Allocate room for the search path and fill in information
722 decompose_rpath (&l
->l_rpath_dirs
,
723 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
724 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
726 l
->l_rpath_dirs
.malloced
= 0;
729 l
->l_rpath_dirs
.dirs
= (void *) -1;
734 if (llp
!= NULL
&& *llp
!= '\0')
737 const char *cp
= llp
;
742 size_t cnt
= DL_DST_COUNT (llp
, 1);
743 if (__builtin_expect (cnt
== 0, 1))
744 llp_tmp
= strdupa (llp
);
747 /* Determine the length of the substituted string. */
748 size_t total
= DL_DST_REQUIRED (l
, llp
, strlen (llp
), cnt
);
750 /* Allocate the necessary memory. */
751 llp_tmp
= (char *) alloca (total
+ 1);
752 llp_tmp
= _dl_dst_substitute (l
, llp
, llp_tmp
, 1);
755 llp_tmp
= strdupa (llp
);
758 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
763 if (*cp
== ':' || *cp
== ';')
768 env_path_list
.dirs
= (struct r_search_path_elem
**)
769 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
770 if (env_path_list
.dirs
== NULL
)
772 errstring
= N_("cannot create cache for search path");
776 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
777 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
780 if (env_path_list
.dirs
[0] == NULL
)
782 free (env_path_list
.dirs
);
783 env_path_list
.dirs
= (void *) -1;
786 env_path_list
.malloced
= 0;
789 env_path_list
.dirs
= (void *) -1;
794 __attribute__ ((noreturn
, noinline
))
795 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
796 const char *msg
, struct r_debug
*r
)
798 /* The file might already be closed. */
806 r
->r_state
= RT_CONSISTENT
;
810 _dl_signal_error (code
, name
, NULL
, msg
);
814 /* Map in the shared object NAME, actually located in REALNAME, and already
817 #ifndef EXTERNAL_MAP_FROM_FD
821 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
822 char *realname
, struct link_map
*loader
, int l_type
,
823 int mode
, void **stack_endp
, Lmid_t nsid
)
825 struct link_map
*l
= NULL
;
826 const ElfW(Ehdr
) *header
;
827 const ElfW(Phdr
) *phdr
;
828 const ElfW(Phdr
) *ph
;
832 /* Initialize to keep the compiler happy. */
833 const char *errstring
= NULL
;
835 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
836 bool make_consistent
= false;
838 /* Get file information. */
839 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
841 errstring
= N_("cannot stat shared object");
845 lose (errval
, fd
, name
, realname
, l
, errstring
,
846 make_consistent
? r
: NULL
);
849 /* Look again to see if the real name matched another already loaded. */
850 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
851 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
853 /* The object is already loaded.
854 Just bump its reference count and return it. */
857 /* If the name is not in the list of names for this object add
860 add_name_to_object (l
, name
);
866 /* When loading into a namespace other than the base one we must
867 avoid loading ld.so since there can only be one copy. Ever. */
868 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
869 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
870 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
871 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
873 /* This is indeed ld.so. Create a new link_map which refers to
874 the real one for almost everything. */
875 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
879 /* Refer to the real descriptor. */
880 l
->l_real
= &GL(dl_rtld_map
);
882 /* No need to bump the refcount of the real object, ld.so will
883 never be unloaded. */
886 /* Add the map for the mirrored object to the object list. */
887 _dl_add_to_namespace_list (l
, nsid
);
893 if (mode
& RTLD_NOLOAD
)
895 /* We are not supposed to load the object unless it is already
896 loaded. So return now. */
901 /* Print debugging message. */
902 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
903 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
905 /* This is the ELF header. We read it in `open_verify'. */
906 header
= (void *) fbp
->buf
;
910 if (_dl_zerofd
== -1)
912 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
913 if (_dl_zerofd
== -1)
916 _dl_signal_error (errno
, NULL
, NULL
,
917 N_("cannot open zero fill device"));
922 /* Signal that we are going to add new objects. */
923 if (r
->r_state
== RT_CONSISTENT
)
926 /* Auditing checkpoint: we are going to add new objects. */
927 if ((mode
& __RTLD_AUDIT
) == 0
928 && __builtin_expect (GLRO(dl_naudit
) > 0, 0))
930 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
931 /* Do not call the functions for any auditing object. */
932 if (head
->l_auditing
== 0)
934 struct audit_ifaces
*afct
= GLRO(dl_audit
);
935 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
937 if (afct
->activity
!= NULL
)
938 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
946 /* Notify the debugger we have added some objects. We need to
947 call _dl_debug_initialize in a static program in case dynamic
948 linking has not been used before. */
951 make_consistent
= true;
954 assert (r
->r_state
== RT_ADD
);
956 /* Enter the new object in the list of loaded objects. */
957 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
958 if (__builtin_expect (l
== NULL
, 0))
963 errstring
= N_("cannot create shared object descriptor");
964 goto call_lose_errno
;
967 /* Extract the remaining details we need from the ELF header
968 and then read in the program header table. */
969 l
->l_entry
= header
->e_entry
;
970 type
= header
->e_type
;
971 l
->l_phnum
= header
->e_phnum
;
973 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
974 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
975 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
978 phdr
= alloca (maplength
);
979 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
980 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
982 errstring
= N_("cannot read file data");
983 goto call_lose_errno
;
987 /* Presumed absent PT_GNU_STACK. */
988 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
991 /* Scan the program header table, collecting its load commands. */
994 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
997 } loadcmds
[l
->l_phnum
], *c
;
998 size_t nloadcmds
= 0;
999 bool has_holes
= false;
1001 /* The struct is initialized to zero so this is not necessary:
1005 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1008 /* These entries tell us where to find things once the file's
1009 segments are mapped in. We record the addresses it says
1010 verbatim, and later correct for the run-time load address. */
1012 l
->l_ld
= (void *) ph
->p_vaddr
;
1013 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1017 l
->l_phdr
= (void *) ph
->p_vaddr
;
1021 /* A load command tells us to map in part of the file.
1022 We record the load commands and process them all later. */
1023 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1026 errstring
= N_("ELF load command alignment not page-aligned");
1029 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1030 & (ph
->p_align
- 1)) != 0, 0))
1033 = N_("ELF load command address/offset not properly aligned");
1037 c
= &loadcmds
[nloadcmds
++];
1038 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1039 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1040 & ~(GLRO(dl_pagesize
) - 1));
1041 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1042 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1043 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1045 /* Determine whether there is a gap between the last segment
1047 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1050 /* Optimize a common case. */
1051 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1052 c
->prot
= (PF_TO_PROT
1053 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1056 if (ph
->p_flags
& PF_R
)
1057 c
->prot
|= PROT_READ
;
1058 if (ph
->p_flags
& PF_W
)
1059 c
->prot
|= PROT_WRITE
;
1060 if (ph
->p_flags
& PF_X
)
1061 c
->prot
|= PROT_EXEC
;
1066 if (ph
->p_memsz
== 0)
1067 /* Nothing to do for an empty segment. */
1070 l
->l_tls_blocksize
= ph
->p_memsz
;
1071 l
->l_tls_align
= ph
->p_align
;
1072 if (ph
->p_align
== 0)
1073 l
->l_tls_firstbyte_offset
= 0;
1075 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1076 l
->l_tls_initimage_size
= ph
->p_filesz
;
1077 /* Since we don't know the load address yet only store the
1078 offset. We will adjust it later. */
1079 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1081 /* If not loading the initial set of shared libraries,
1082 check whether we should permit loading a TLS segment. */
1083 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1084 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1085 not set up TLS data structures, so don't use them now. */
1086 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1088 /* Assign the next available module ID. */
1089 l
->l_tls_modid
= _dl_next_tls_modid ();
1094 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1095 /* We are loading the executable itself when the dynamic linker
1096 was executed directly. The setup will happen later. */
1099 /* In a static binary there is no way to tell if we dynamically
1100 loaded libpthread. */
1101 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1104 /* We have not yet loaded libpthread.
1105 We can do the TLS setup right now! */
1109 /* The first call allocates TLS bookkeeping data structures.
1110 Then we allocate the TCB for the initial thread. */
1111 if (__builtin_expect (_dl_tls_setup (), 0)
1112 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1117 cannot allocate TLS data structures for initial thread");
1121 /* Now we install the TCB in the thread register. */
1122 errstring
= TLS_INIT_TP (tcb
, 0);
1123 if (__builtin_expect (errstring
== NULL
, 1))
1125 /* Now we are all good. */
1126 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1130 /* The kernel is too old or somesuch. */
1132 _dl_deallocate_tls (tcb
, 1);
1136 /* Uh-oh, the binary expects TLS support but we cannot
1139 errstring
= N_("cannot handle TLS data");
1144 stack_flags
= ph
->p_flags
;
1148 l
->l_relro_addr
= ph
->p_vaddr
;
1149 l
->l_relro_size
= ph
->p_memsz
;
1153 if (__builtin_expect (nloadcmds
== 0, 0))
1155 /* This only happens for a bogus object that will be caught with
1156 another error below. But we don't want to go through the
1157 calculations below using NLOADCMDS - 1. */
1158 errstring
= N_("object file has no loadable segments");
1162 /* Now process the load commands and map segments into memory. */
1165 /* Length of the sections to be loaded. */
1166 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1168 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1170 /* This is a position-independent shared object. We can let the
1171 kernel map it anywhere it likes, but we must have space for all
1172 the segments in their specified positions relative to the first.
1173 So we map the first segment without MAP_FIXED, but with its
1174 extent increased to cover all the segments. Then we remove
1175 access from excess portion, and there is known sufficient space
1176 there to remap from the later segments.
1178 As a refinement, sometimes we have an address that we would
1179 prefer to map such objects at; but this is only a preference,
1180 the OS can do whatever it likes. */
1182 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1183 c
->mapstart
& GLRO(dl_use_load_bias
))
1184 - MAP_BASE_ADDR (l
));
1186 /* Remember which part of the address space this object uses. */
1187 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1191 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1194 errstring
= N_("failed to map segment from shared object");
1195 goto call_lose_errno
;
1198 l
->l_map_end
= l
->l_map_start
+ maplength
;
1199 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1202 /* Change protection on the excess portion to disallow all access;
1203 the portions we do not remap later will be inaccessible as if
1204 unallocated. Then jump into the normal segment-mapping loop to
1205 handle the portion of the segment past the end of the file
1207 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1208 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1211 l
->l_contiguous
= 1;
1216 /* This object is loaded at a fixed address. This must never
1217 happen for objects loaded with dlopen(). */
1218 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1220 errstring
= N_("cannot dynamically load executable");
1224 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1226 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1229 /* Remember which part of the address space this object uses. */
1230 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1231 l
->l_map_end
= l
->l_map_start
+ maplength
;
1232 l
->l_contiguous
= !has_holes
;
1234 while (c
< &loadcmds
[nloadcmds
])
1236 if (c
->mapend
> c
->mapstart
1237 /* Map the segment contents from the file. */
1238 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1239 c
->mapend
- c
->mapstart
, c
->prot
,
1240 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1246 if (c
->prot
& PROT_EXEC
)
1247 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1250 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1251 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1252 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1253 /* Found the program header in this segment. */
1254 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1256 if (c
->allocend
> c
->dataend
)
1258 /* Extra zero pages should appear at the end of this segment,
1259 after the data mapped from the file. */
1260 ElfW(Addr
) zero
, zeroend
, zeropage
;
1262 zero
= l
->l_addr
+ c
->dataend
;
1263 zeroend
= l
->l_addr
+ c
->allocend
;
1264 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1265 & ~(GLRO(dl_pagesize
) - 1));
1267 if (zeroend
< zeropage
)
1268 /* All the extra data is in the last page of the segment.
1269 We can just zero it. */
1272 if (zeropage
> zero
)
1274 /* Zero the final part of the last page of the segment. */
1275 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1278 if (__mprotect ((caddr_t
) (zero
1279 & ~(GLRO(dl_pagesize
) - 1)),
1280 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1282 errstring
= N_("cannot change memory protections");
1283 goto call_lose_errno
;
1286 memset ((void *) zero
, '\0', zeropage
- zero
);
1287 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1288 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1289 GLRO(dl_pagesize
), c
->prot
);
1292 if (zeroend
> zeropage
)
1294 /* Map the remaining zero pages in from the zero fill FD. */
1296 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1297 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1299 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1301 errstring
= N_("cannot map zero-fill pages");
1302 goto call_lose_errno
;
1313 if (__builtin_expect (type
== ET_DYN
, 0))
1315 errstring
= N_("object file has no dynamic section");
1320 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1322 elf_get_dynamic_info (l
, NULL
);
1324 /* Make sure we are not dlopen'ing an object that has the
1325 DF_1_NOOPEN flag set. */
1326 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1327 && (mode
& __RTLD_DLOPEN
))
1329 /* We are not supposed to load this object. Free all resources. */
1330 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1332 if (!l
->l_libname
->dont_free
)
1333 free (l
->l_libname
);
1335 if (l
->l_phdr_allocated
)
1336 free ((void *) l
->l_phdr
);
1338 errstring
= N_("shared object cannot be dlopen()ed");
1342 if (l
->l_phdr
== NULL
)
1344 /* The program header is not contained in any of the segments.
1345 We have to allocate memory ourself and copy it over from out
1347 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1348 * sizeof (ElfW(Phdr
)));
1351 errstring
= N_("cannot allocate memory for program header");
1352 goto call_lose_errno
;
1355 l
->l_phdr
= memcpy (newp
, phdr
,
1356 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1357 l
->l_phdr_allocated
= 1;
1360 /* Adjust the PT_PHDR value by the runtime load address. */
1361 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1363 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1365 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1368 errstring
= N_("invalid caller");
1372 /* The stack is presently not executable, but this module
1373 requires that it be executable. We must change the
1374 protection of the variable which contains the flags used in
1375 the mprotect calls. */
1377 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1379 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1380 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1382 struct link_map
*const m
= &GL(dl_rtld_map
);
1383 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1385 & -GLRO(dl_pagesize
));
1386 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1388 /* The variable lies in the region protected by RELRO. */
1389 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1390 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1391 __mprotect ((void *) p
, s
, PROT_READ
);
1394 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1398 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1400 #ifdef check_consistency
1401 check_consistency ();
1404 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1408 cannot enable executable stack as shared object requires");
1413 /* Adjust the address of the TLS initialization image. */
1414 if (l
->l_tls_initimage
!= NULL
)
1415 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1417 /* We are done mapping in the file. We no longer need the descriptor. */
1418 if (__builtin_expect (__close (fd
) != 0, 0))
1420 errstring
= N_("cannot close file descriptor");
1421 goto call_lose_errno
;
1423 /* Signal that we closed the file. */
1426 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1427 l
->l_type
= lt_executable
;
1429 l
->l_entry
+= l
->l_addr
;
1431 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1432 _dl_debug_printf ("\
1433 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1434 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1435 (int) sizeof (void *) * 2,
1436 (unsigned long int) l
->l_ld
,
1437 (int) sizeof (void *) * 2,
1438 (unsigned long int) l
->l_addr
,
1439 (int) sizeof (void *) * 2, maplength
,
1440 (int) sizeof (void *) * 2,
1441 (unsigned long int) l
->l_entry
,
1442 (int) sizeof (void *) * 2,
1443 (unsigned long int) l
->l_phdr
,
1444 (int) sizeof (void *) * 2, l
->l_phnum
);
1446 /* Set up the symbol hash table. */
1449 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1450 have to do this for the main map. */
1451 if ((mode
& RTLD_DEEPBIND
) == 0
1452 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1453 && &l
->l_searchlist
!= l
->l_scope
[0])
1455 /* Create an appropriate searchlist. It contains only this map.
1456 This is the definition of DT_SYMBOLIC in SysVr4. */
1457 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1458 l
->l_symbolic_searchlist
.r_nlist
= 1;
1460 /* Now move the existing entries one back. */
1461 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1462 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1464 /* Now add the new entry. */
1465 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1468 /* Remember whether this object must be initialized first. */
1469 if (l
->l_flags_1
& DF_1_INITFIRST
)
1470 GL(dl_initfirst
) = l
;
1472 /* Finally the file information. */
1473 l
->l_dev
= st
.st_dev
;
1474 l
->l_ino
= st
.st_ino
;
1476 /* When we profile the SONAME might be needed for something else but
1477 loading. Add it right away. */
1478 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1479 && l
->l_info
[DT_SONAME
] != NULL
)
1480 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1481 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1483 /* Now that the object is fully initialized add it to the object list. */
1484 _dl_add_to_namespace_list (l
, nsid
);
1487 /* Auditing checkpoint: we have a new object. */
1488 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1489 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1491 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1492 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1494 if (afct
->objopen
!= NULL
)
1496 l
->l_audit
[cnt
].bindflags
1497 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1499 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1510 /* Print search path. */
1512 print_search_path (struct r_search_path_elem
**list
,
1513 const char *what
, const char *name
)
1515 char buf
[max_dirnamelen
+ max_capstrlen
];
1518 _dl_debug_printf (" search path=");
1520 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1522 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1525 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1526 if ((*list
)->status
[cnt
] != nonexisting
)
1528 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1529 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1534 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1542 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1543 name
[0] ? name
: rtld_progname
);
1545 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1548 /* Open a file and verify it is an ELF file for this architecture. We
1549 ignore only ELF files for other architectures. Non-ELF files and
1550 ELF files with different header information cause fatal errors since
1551 this could mean there is something wrong in the installation and the
1552 user might want to know about this. */
1554 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1555 int whatcode
, bool *found_other_class
, bool free_name
)
1557 /* This is the expected ELF header. */
1558 #define ELF32_CLASS ELFCLASS32
1559 #define ELF64_CLASS ELFCLASS64
1560 #ifndef VALID_ELF_HEADER
1561 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1562 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1563 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1564 #elif defined MORE_ELF_HEADER_DATA
1565 MORE_ELF_HEADER_DATA
;
1567 static const unsigned char expected
[EI_NIDENT
] =
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
;
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"));
1640 char *realname
= (char *) name
;
1641 name
= strdupa (realname
);
1644 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1647 /* See whether the ELF header is what we expect. */
1648 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1650 || !VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1651 ehdr
->e_ident
[EI_ABIVERSION
])
1652 || memcmp (&ehdr
->e_ident
[EI_PAD
],
1654 EI_NIDENT
- EI_PAD
) != 0,
1657 /* Something is wrong. */
1658 const Elf32_Word
*magp
= (const void *) ehdr
->e_ident
;
1660 #if BYTE_ORDER == LITTLE_ENDIAN
1661 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1662 (ELFMAG1
<< (EI_MAG1
* 8)) |
1663 (ELFMAG2
<< (EI_MAG2
* 8)) |
1664 (ELFMAG3
<< (EI_MAG3
* 8)))
1666 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1667 (ELFMAG1
<< (EI_MAG2
* 8)) |
1668 (ELFMAG2
<< (EI_MAG1
* 8)) |
1669 (ELFMAG3
<< (EI_MAG0
* 8)))
1672 errstring
= N_("invalid ELF header");
1673 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1675 /* This is not a fatal error. On architectures where
1676 32-bit and 64-bit binaries can be run this might
1678 *found_other_class
= true;
1681 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1683 if (BYTE_ORDER
== BIG_ENDIAN
)
1684 errstring
= N_("ELF file data encoding not big-endian");
1686 errstring
= N_("ELF file data encoding not little-endian");
1688 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1690 = N_("ELF file version ident does not match current one");
1691 /* XXX We should be able so set system specific versions which are
1693 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1694 errstring
= N_("ELF file OS ABI invalid");
1695 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1696 ehdr
->e_ident
[EI_ABIVERSION
]))
1697 errstring
= N_("ELF file ABI version invalid");
1698 else if (memcmp (&ehdr
->e_ident
[EI_PAD
], &expected
[EI_PAD
],
1699 EI_NIDENT
- EI_PAD
) != 0)
1700 errstring
= N_("nonzero padding in e_ident");
1702 /* Otherwise we don't know what went wrong. */
1703 errstring
= N_("internal error");
1708 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1710 errstring
= N_("ELF file version does not match current one");
1713 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1715 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1716 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1718 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1721 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1722 != sizeof (ElfW(Phdr
)))
1724 errstring
= N_("ELF file's phentsize not the expected size");
1728 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1729 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1730 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1733 phdr
= alloca (maplength
);
1734 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1735 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1739 errstring
= N_("cannot read file data");
1744 /* Check .note.ABI-tag if present. */
1745 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1746 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1748 ElfW(Addr
) size
= ph
->p_filesz
;
1750 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1751 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1754 abi_note
= alloca (size
);
1755 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1756 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1760 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1762 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1763 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1764 + ROUND (abi_note
[0])
1765 + ROUND (abi_note
[1]);
1767 if (size
- 32 < note_size
)
1773 abi_note
= (void *) abi_note
+ note_size
;
1779 osversion
= (abi_note
[5] & 0xff) * 65536
1780 + (abi_note
[6] & 0xff) * 256
1781 + (abi_note
[7] & 0xff);
1782 if (abi_note
[4] != __ABI_TAG_OS
1783 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1787 __set_errno (ENOENT
);
1798 /* Try to open NAME in one of the directories in *DIRSP.
1799 Return the fd, or -1. If successful, fill in *REALNAME
1800 with the malloc'd full directory name. If it turns out
1801 that none of the directories in *DIRSP exists, *DIRSP is
1802 replaced with (void *) -1, and the old value is free()d
1803 if MAY_FREE_DIRS is true. */
1806 open_path (const char *name
, size_t namelen
, int secure
,
1807 struct r_search_path_struct
*sps
, char **realname
,
1808 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1809 bool *found_other_class
)
1811 struct r_search_path_elem
**dirs
= sps
->dirs
;
1814 const char *current_what
= NULL
;
1817 if (__builtin_expect (dirs
== NULL
, 0))
1818 /* We're called before _dl_init_paths when loading the main executable
1819 given on the command line when rtld is run directly. */
1822 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1825 struct r_search_path_elem
*this_dir
= *dirs
;
1832 /* If we are debugging the search for libraries print the path
1833 now if it hasn't happened now. */
1834 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1835 && current_what
!= this_dir
->what
)
1837 current_what
= this_dir
->what
;
1838 print_search_path (dirs
, current_what
, this_dir
->where
);
1841 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1842 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1844 /* Skip this directory if we know it does not exist. */
1845 if (this_dir
->status
[cnt
] == nonexisting
)
1849 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1854 /* Print name we try if this is wanted. */
1855 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1856 _dl_debug_printf (" trying file=%s\n", buf
);
1858 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1860 if (this_dir
->status
[cnt
] == unknown
)
1863 this_dir
->status
[cnt
] = existing
;
1864 /* Do not update the directory information when loading
1865 auditing code. We must try to disturb the program as
1866 little as possible. */
1867 else if (loader
== NULL
1868 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1870 /* We failed to open machine dependent library. Let's
1871 test whether there is any directory at all. */
1874 buf
[buflen
- namelen
- 1] = '\0';
1876 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1877 || ! S_ISDIR (st
.st_mode
))
1878 /* The directory does not exist or it is no directory. */
1879 this_dir
->status
[cnt
] = nonexisting
;
1881 this_dir
->status
[cnt
] = existing
;
1885 /* Remember whether we found any existing directory. */
1886 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1888 if (fd
!= -1 && __builtin_expect (secure
, 0)
1889 && INTUSE(__libc_enable_secure
))
1891 /* This is an extra security effort to make sure nobody can
1892 preload broken shared objects which are in the trusted
1893 directories and so exploit the bugs. */
1896 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1897 || (st
.st_mode
& S_ISUID
) == 0)
1899 /* The shared object cannot be tested for being SUID
1900 or this bit is not set. In this case we must not
1904 /* We simply ignore the file, signal this by setting
1905 the error value which would have been set by `open'. */
1913 *realname
= (char *) malloc (buflen
);
1914 if (*realname
!= NULL
)
1916 memcpy (*realname
, buf
, buflen
);
1921 /* No memory for the name, we certainly won't be able
1922 to load and link it. */
1927 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1928 /* The file exists and is readable, but something went wrong. */
1931 /* Remember whether we found anything. */
1934 while (*++dirs
!= NULL
);
1936 /* Remove the whole path if none of the directories exists. */
1937 if (__builtin_expect (! any
, 0))
1939 /* Paths which were allocated using the minimal malloc() in ld.so
1940 must not be freed using the general free() in libc. */
1944 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1946 if (sps
!= &rtld_search_dirs
)
1947 sps
->dirs
= (void *) -1;
1953 /* Map in the shared object file NAME. */
1957 _dl_map_object (struct link_map
*loader
, const char *name
,
1958 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1967 assert (nsid
< GL(dl_nns
));
1969 /* Look for this name among those already loaded. */
1970 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1972 /* If the requested name matches the soname of a loaded object,
1973 use that object. Elide this check for names that have not
1975 if (__builtin_expect (l
->l_faked
, 0) != 0
1976 || __builtin_expect (l
->l_removed
, 0) != 0)
1978 if (!_dl_name_match_p (name
, l
))
1982 if (__builtin_expect (l
->l_soname_added
, 1)
1983 || l
->l_info
[DT_SONAME
] == NULL
)
1986 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1987 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1988 if (strcmp (name
, soname
) != 0)
1991 /* We have a match on a new name -- cache it. */
1992 add_name_to_object (l
, soname
);
1993 l
->l_soname_added
= 1;
1996 /* We have a match. */
2000 /* Display information if we are debugging. */
2001 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2003 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2005 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2008 /* Give the auditing libraries a chance to change the name before we
2010 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2011 && (loader
== NULL
|| loader
->l_auditing
== 0))
2013 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2014 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2016 if (afct
->objsearch
!= NULL
)
2018 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2022 /* Do not try anything further. */
2033 /* Will be true if we found a DSO which is of the other ELF class. */
2034 bool found_other_class
= false;
2036 if (strchr (name
, '/') == NULL
)
2038 /* Search for NAME in several places. */
2040 size_t namelen
= strlen (name
) + 1;
2042 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2043 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2047 /* When the object has the RUNPATH information we don't use any
2049 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2051 /* This is the executable's map (if there is one). Make sure that
2052 we do not look at it twice. */
2053 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2054 bool did_main_map
= false;
2056 /* First try the DT_RPATH of the dependent object that caused NAME
2057 to be loaded. Then that object's dependent, and on up. */
2058 for (l
= loader
; l
; l
= l
->l_loader
)
2059 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2061 fd
= open_path (name
, namelen
, mode
& __RTLD_SECURE
,
2063 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2064 &found_other_class
);
2068 did_main_map
|= l
== main_map
;
2071 /* If dynamically linked, try the DT_RPATH of the executable
2072 itself. NB: we do this for lookups in any namespace. */
2073 if (fd
== -1 && !did_main_map
2074 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2075 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2077 fd
= open_path (name
, namelen
, mode
& __RTLD_SECURE
,
2078 &main_map
->l_rpath_dirs
,
2079 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2080 &found_other_class
);
2083 /* Try the LD_LIBRARY_PATH environment variable. */
2084 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2085 fd
= open_path (name
, namelen
, mode
& __RTLD_SECURE
, &env_path_list
,
2087 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2088 LA_SER_LIBPATH
, &found_other_class
);
2090 /* Look at the RUNPATH information for this binary. */
2091 if (fd
== -1 && loader
!= NULL
2092 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2093 DT_RUNPATH
, "RUNPATH"))
2094 fd
= open_path (name
, namelen
, mode
& __RTLD_SECURE
,
2095 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2096 LA_SER_RUNPATH
, &found_other_class
);
2099 && (__builtin_expect (! (mode
& __RTLD_SECURE
), 1)
2100 || ! INTUSE(__libc_enable_secure
)))
2102 /* Check the list of libraries in the file /etc/ld.so.cache,
2103 for compatibility with Linux's ldconfig program. */
2104 const char *cached
= _dl_load_cache_lookup (name
);
2109 // XXX Correct to unconditionally default to namespace 0?
2110 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2115 /* If the loader has the DF_1_NODEFLIB flag set we must not
2116 use a cache entry from any of these directories. */
2119 /* 'l' is always != NULL for dynamically linked objects. */
2122 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2124 const char *dirp
= system_dirs
;
2125 unsigned int cnt
= 0;
2129 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2131 /* The prefix matches. Don't use the entry. */
2136 dirp
+= system_dirs_len
[cnt
] + 1;
2139 while (cnt
< nsystem_dirs_len
);
2144 fd
= open_verify (cached
,
2145 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2146 LA_SER_CONFIG
, &found_other_class
, false);
2147 if (__builtin_expect (fd
!= -1, 1))
2149 realname
= local_strdup (cached
);
2150 if (realname
== NULL
)
2160 /* Finally, try the default path. */
2162 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2163 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2164 && rtld_search_dirs
.dirs
!= (void *) -1)
2165 fd
= open_path (name
, namelen
, mode
& __RTLD_SECURE
, &rtld_search_dirs
,
2166 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2168 /* Add another newline when we are tracing the library loading. */
2169 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2170 _dl_debug_printf ("\n");
2174 /* The path may contain dynamic string tokens. */
2176 ? expand_dynamic_string_token (loader
, name
)
2177 : local_strdup (name
));
2178 if (realname
== NULL
)
2182 fd
= open_verify (realname
, &fb
,
2183 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2184 &found_other_class
, true);
2185 if (__builtin_expect (fd
, 0) == -1)
2193 /* In case the LOADER information has only been provided to get to
2194 the appropriate RUNPATH/RPATH information we do not need it
2196 if (mode
& __RTLD_CALLMAP
)
2199 if (__builtin_expect (fd
, 0) == -1)
2202 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2204 /* We haven't found an appropriate library. But since we
2205 are only interested in the list of libraries this isn't
2206 so severe. Fake an entry with all the information we
2208 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2210 /* Allocate a new object map. */
2211 if ((name_copy
= local_strdup (name
)) == NULL
2212 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2213 mode
, nsid
)) == NULL
)
2216 _dl_signal_error (ENOMEM
, name
, NULL
,
2217 N_("cannot create shared object descriptor"));
2219 /* Signal that this is a faked entry. */
2221 /* Since the descriptor is initialized with zero we do not
2223 l->l_reserved = 0; */
2224 l
->l_buckets
= &dummy_bucket
;
2228 /* Enter the object in the object list. */
2229 _dl_add_to_namespace_list (l
, nsid
);
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
;