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;
791 /* Remember the last search directory added at startup. */
792 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
797 __attribute__ ((noreturn
, noinline
))
798 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
799 const char *msg
, struct r_debug
*r
)
801 /* The file might already be closed. */
806 /* Remove the stillborn object from the list and free it. */
807 assert (l
->l_next
== NULL
);
808 if (l
->l_prev
== NULL
)
809 /* No other module loaded. This happens only in the static library,
810 or in rtld under --verify. */
811 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
813 l
->l_prev
->l_next
= NULL
;
814 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
821 r
->r_state
= RT_CONSISTENT
;
825 _dl_signal_error (code
, name
, NULL
, msg
);
829 /* Map in the shared object NAME, actually located in REALNAME, and already
832 #ifndef EXTERNAL_MAP_FROM_FD
836 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
837 char *realname
, struct link_map
*loader
, int l_type
,
838 int mode
, void **stack_endp
, Lmid_t nsid
)
840 struct link_map
*l
= NULL
;
841 const ElfW(Ehdr
) *header
;
842 const ElfW(Phdr
) *phdr
;
843 const ElfW(Phdr
) *ph
;
847 /* Initialize to keep the compiler happy. */
848 const char *errstring
= NULL
;
850 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
851 bool make_consistent
= false;
853 /* Get file information. */
854 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
856 errstring
= N_("cannot stat shared object");
860 lose (errval
, fd
, name
, realname
, l
, errstring
,
861 make_consistent
? r
: NULL
);
864 /* Look again to see if the real name matched another already loaded. */
865 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
866 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
868 /* The object is already loaded.
869 Just bump its reference count and return it. */
872 /* If the name is not in the list of names for this object add
875 add_name_to_object (l
, name
);
881 /* When loading into a namespace other than the base one we must
882 avoid loading ld.so since there can only be one copy. Ever. */
883 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
884 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
885 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
886 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
888 /* This is indeed ld.so. Create a new link_map which refers to
889 the real one for almost everything. */
890 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
894 /* Refer to the real descriptor. */
895 l
->l_real
= &GL(dl_rtld_map
);
897 /* No need to bump the refcount of the real object, ld.so will
898 never be unloaded. */
905 if (mode
& RTLD_NOLOAD
)
907 /* We are not supposed to load the object unless it is already
908 loaded. So return now. */
913 /* Print debugging message. */
914 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
915 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
917 /* This is the ELF header. We read it in `open_verify'. */
918 header
= (void *) fbp
->buf
;
922 if (_dl_zerofd
== -1)
924 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
925 if (_dl_zerofd
== -1)
928 _dl_signal_error (errno
, NULL
, NULL
,
929 N_("cannot open zero fill device"));
934 /* Signal that we are going to add new objects. */
935 if (r
->r_state
== RT_CONSISTENT
)
938 /* Auditing checkpoint: we are going to add new objects. */
939 if ((mode
& __RTLD_AUDIT
) == 0
940 && __builtin_expect (GLRO(dl_naudit
) > 0, 0))
942 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
943 /* Do not call the functions for any auditing object. */
944 if (head
->l_auditing
== 0)
946 struct audit_ifaces
*afct
= GLRO(dl_audit
);
947 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
949 if (afct
->activity
!= NULL
)
950 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
958 /* Notify the debugger we have added some objects. We need to
959 call _dl_debug_initialize in a static program in case dynamic
960 linking has not been used before. */
963 make_consistent
= true;
966 assert (r
->r_state
== RT_ADD
);
968 /* Enter the new object in the list of loaded objects. */
969 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
970 if (__builtin_expect (l
== NULL
, 0))
975 errstring
= N_("cannot create shared object descriptor");
976 goto call_lose_errno
;
979 /* Extract the remaining details we need from the ELF header
980 and then read in the program header table. */
981 l
->l_entry
= header
->e_entry
;
982 type
= header
->e_type
;
983 l
->l_phnum
= header
->e_phnum
;
985 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
986 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
987 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
990 phdr
= alloca (maplength
);
991 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
992 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
994 errstring
= N_("cannot read file data");
995 goto call_lose_errno
;
999 /* Presumed absent PT_GNU_STACK. */
1000 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
1003 /* Scan the program header table, collecting its load commands. */
1006 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
1009 } loadcmds
[l
->l_phnum
], *c
;
1010 size_t nloadcmds
= 0;
1011 bool has_holes
= false;
1013 /* The struct is initialized to zero so this is not necessary:
1017 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1020 /* These entries tell us where to find things once the file's
1021 segments are mapped in. We record the addresses it says
1022 verbatim, and later correct for the run-time load address. */
1024 l
->l_ld
= (void *) ph
->p_vaddr
;
1025 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1029 l
->l_phdr
= (void *) ph
->p_vaddr
;
1033 /* A load command tells us to map in part of the file.
1034 We record the load commands and process them all later. */
1035 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1038 errstring
= N_("ELF load command alignment not page-aligned");
1041 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1042 & (ph
->p_align
- 1)) != 0, 0))
1045 = N_("ELF load command address/offset not properly aligned");
1049 c
= &loadcmds
[nloadcmds
++];
1050 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1051 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1052 & ~(GLRO(dl_pagesize
) - 1));
1053 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1054 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1055 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1057 /* Determine whether there is a gap between the last segment
1059 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1062 /* Optimize a common case. */
1063 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1064 c
->prot
= (PF_TO_PROT
1065 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1068 if (ph
->p_flags
& PF_R
)
1069 c
->prot
|= PROT_READ
;
1070 if (ph
->p_flags
& PF_W
)
1071 c
->prot
|= PROT_WRITE
;
1072 if (ph
->p_flags
& PF_X
)
1073 c
->prot
|= PROT_EXEC
;
1078 if (ph
->p_memsz
== 0)
1079 /* Nothing to do for an empty segment. */
1082 l
->l_tls_blocksize
= ph
->p_memsz
;
1083 l
->l_tls_align
= ph
->p_align
;
1084 if (ph
->p_align
== 0)
1085 l
->l_tls_firstbyte_offset
= 0;
1087 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1088 l
->l_tls_initimage_size
= ph
->p_filesz
;
1089 /* Since we don't know the load address yet only store the
1090 offset. We will adjust it later. */
1091 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1093 /* If not loading the initial set of shared libraries,
1094 check whether we should permit loading a TLS segment. */
1095 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1096 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1097 not set up TLS data structures, so don't use them now. */
1098 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1100 /* Assign the next available module ID. */
1101 l
->l_tls_modid
= _dl_next_tls_modid ();
1106 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1107 /* We are loading the executable itself when the dynamic linker
1108 was executed directly. The setup will happen later. */
1111 /* In a static binary there is no way to tell if we dynamically
1112 loaded libpthread. */
1113 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1116 /* We have not yet loaded libpthread.
1117 We can do the TLS setup right now! */
1121 /* The first call allocates TLS bookkeeping data structures.
1122 Then we allocate the TCB for the initial thread. */
1123 if (__builtin_expect (_dl_tls_setup (), 0)
1124 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1129 cannot allocate TLS data structures for initial thread");
1133 /* Now we install the TCB in the thread register. */
1134 errstring
= TLS_INIT_TP (tcb
, 0);
1135 if (__builtin_expect (errstring
== NULL
, 1))
1137 /* Now we are all good. */
1138 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1142 /* The kernel is too old or somesuch. */
1144 _dl_deallocate_tls (tcb
, 1);
1148 /* Uh-oh, the binary expects TLS support but we cannot
1151 errstring
= N_("cannot handle TLS data");
1156 stack_flags
= ph
->p_flags
;
1160 l
->l_relro_addr
= ph
->p_vaddr
;
1161 l
->l_relro_size
= ph
->p_memsz
;
1165 if (__builtin_expect (nloadcmds
== 0, 0))
1167 /* This only happens for a bogus object that will be caught with
1168 another error below. But we don't want to go through the
1169 calculations below using NLOADCMDS - 1. */
1170 errstring
= N_("object file has no loadable segments");
1174 /* Now process the load commands and map segments into memory. */
1177 /* Length of the sections to be loaded. */
1178 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1180 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1182 /* This is a position-independent shared object. We can let the
1183 kernel map it anywhere it likes, but we must have space for all
1184 the segments in their specified positions relative to the first.
1185 So we map the first segment without MAP_FIXED, but with its
1186 extent increased to cover all the segments. Then we remove
1187 access from excess portion, and there is known sufficient space
1188 there to remap from the later segments.
1190 As a refinement, sometimes we have an address that we would
1191 prefer to map such objects at; but this is only a preference,
1192 the OS can do whatever it likes. */
1194 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1195 c
->mapstart
& GLRO(dl_use_load_bias
))
1196 - MAP_BASE_ADDR (l
));
1198 /* Remember which part of the address space this object uses. */
1199 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1203 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1206 errstring
= N_("failed to map segment from shared object");
1207 goto call_lose_errno
;
1210 l
->l_map_end
= l
->l_map_start
+ maplength
;
1211 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1214 /* Change protection on the excess portion to disallow all access;
1215 the portions we do not remap later will be inaccessible as if
1216 unallocated. Then jump into the normal segment-mapping loop to
1217 handle the portion of the segment past the end of the file
1219 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1220 loadcmds
[nloadcmds
- 1].mapstart
- c
->mapend
,
1223 l
->l_contiguous
= 1;
1228 /* This object is loaded at a fixed address. This must never
1229 happen for objects loaded with dlopen(). */
1230 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1232 errstring
= N_("cannot dynamically load executable");
1236 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1238 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1241 /* Remember which part of the address space this object uses. */
1242 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1243 l
->l_map_end
= l
->l_map_start
+ maplength
;
1244 l
->l_contiguous
= !has_holes
;
1246 while (c
< &loadcmds
[nloadcmds
])
1248 if (c
->mapend
> c
->mapstart
1249 /* Map the segment contents from the file. */
1250 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1251 c
->mapend
- c
->mapstart
, c
->prot
,
1252 MAP_FIXED
|MAP_COPY
|MAP_FILE
,
1258 if (c
->prot
& PROT_EXEC
)
1259 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1262 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1263 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1264 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1265 /* Found the program header in this segment. */
1266 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1268 if (c
->allocend
> c
->dataend
)
1270 /* Extra zero pages should appear at the end of this segment,
1271 after the data mapped from the file. */
1272 ElfW(Addr
) zero
, zeroend
, zeropage
;
1274 zero
= l
->l_addr
+ c
->dataend
;
1275 zeroend
= l
->l_addr
+ c
->allocend
;
1276 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1277 & ~(GLRO(dl_pagesize
) - 1));
1279 if (zeroend
< zeropage
)
1280 /* All the extra data is in the last page of the segment.
1281 We can just zero it. */
1284 if (zeropage
> zero
)
1286 /* Zero the final part of the last page of the segment. */
1287 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1290 if (__mprotect ((caddr_t
) (zero
1291 & ~(GLRO(dl_pagesize
) - 1)),
1292 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1294 errstring
= N_("cannot change memory protections");
1295 goto call_lose_errno
;
1298 memset ((void *) zero
, '\0', zeropage
- zero
);
1299 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1300 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1301 GLRO(dl_pagesize
), c
->prot
);
1304 if (zeroend
> zeropage
)
1306 /* Map the remaining zero pages in from the zero fill FD. */
1308 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1309 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1311 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1313 errstring
= N_("cannot map zero-fill pages");
1314 goto call_lose_errno
;
1325 if (__builtin_expect (type
== ET_DYN
, 0))
1327 errstring
= N_("object file has no dynamic section");
1332 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1334 elf_get_dynamic_info (l
, NULL
);
1336 /* Make sure we are not dlopen'ing an object that has the
1337 DF_1_NOOPEN flag set. */
1338 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1339 && (mode
& __RTLD_DLOPEN
))
1341 /* We are not supposed to load this object. Free all resources. */
1342 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1344 if (!l
->l_libname
->dont_free
)
1345 free (l
->l_libname
);
1347 if (l
->l_phdr_allocated
)
1348 free ((void *) l
->l_phdr
);
1350 errstring
= N_("shared object cannot be dlopen()ed");
1354 if (l
->l_phdr
== NULL
)
1356 /* The program header is not contained in any of the segments.
1357 We have to allocate memory ourself and copy it over from out
1359 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1360 * sizeof (ElfW(Phdr
)));
1363 errstring
= N_("cannot allocate memory for program header");
1364 goto call_lose_errno
;
1367 l
->l_phdr
= memcpy (newp
, phdr
,
1368 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1369 l
->l_phdr_allocated
= 1;
1372 /* Adjust the PT_PHDR value by the runtime load address. */
1373 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1375 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1377 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0), allow_ldso
),
1380 errstring
= N_("invalid caller");
1384 /* The stack is presently not executable, but this module
1385 requires that it be executable. We must change the
1386 protection of the variable which contains the flags used in
1387 the mprotect calls. */
1389 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1391 const uintptr_t p
= (uintptr_t) &__stack_prot
& -GLRO(dl_pagesize
);
1392 const size_t s
= (uintptr_t) (&__stack_prot
+ 1) - p
;
1394 struct link_map
*const m
= &GL(dl_rtld_map
);
1395 const uintptr_t relro_end
= ((m
->l_addr
+ m
->l_relro_addr
1397 & -GLRO(dl_pagesize
));
1398 if (__builtin_expect (p
+ s
<= relro_end
, 1))
1400 /* The variable lies in the region protected by RELRO. */
1401 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1402 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1403 __mprotect ((void *) p
, s
, PROT_READ
);
1406 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1410 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1412 #ifdef check_consistency
1413 check_consistency ();
1416 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1420 cannot enable executable stack as shared object requires");
1425 /* Adjust the address of the TLS initialization image. */
1426 if (l
->l_tls_initimage
!= NULL
)
1427 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1429 /* We are done mapping in the file. We no longer need the descriptor. */
1430 if (__builtin_expect (__close (fd
) != 0, 0))
1432 errstring
= N_("cannot close file descriptor");
1433 goto call_lose_errno
;
1435 /* Signal that we closed the file. */
1438 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1439 l
->l_type
= lt_executable
;
1441 l
->l_entry
+= l
->l_addr
;
1443 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1444 _dl_debug_printf ("\
1445 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1446 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1447 (int) sizeof (void *) * 2,
1448 (unsigned long int) l
->l_ld
,
1449 (int) sizeof (void *) * 2,
1450 (unsigned long int) l
->l_addr
,
1451 (int) sizeof (void *) * 2, maplength
,
1452 (int) sizeof (void *) * 2,
1453 (unsigned long int) l
->l_entry
,
1454 (int) sizeof (void *) * 2,
1455 (unsigned long int) l
->l_phdr
,
1456 (int) sizeof (void *) * 2, l
->l_phnum
);
1458 /* Set up the symbol hash table. */
1461 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1462 have to do this for the main map. */
1463 if ((mode
& RTLD_DEEPBIND
) == 0
1464 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1465 && &l
->l_searchlist
!= l
->l_scope
[0])
1467 /* Create an appropriate searchlist. It contains only this map.
1468 This is the definition of DT_SYMBOLIC in SysVr4. */
1469 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1470 l
->l_symbolic_searchlist
.r_nlist
= 1;
1472 /* Now move the existing entries one back. */
1473 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1474 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1476 /* Now add the new entry. */
1477 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1480 /* Remember whether this object must be initialized first. */
1481 if (l
->l_flags_1
& DF_1_INITFIRST
)
1482 GL(dl_initfirst
) = l
;
1484 /* Finally the file information. */
1485 l
->l_dev
= st
.st_dev
;
1486 l
->l_ino
= st
.st_ino
;
1488 /* When we profile the SONAME might be needed for something else but
1489 loading. Add it right away. */
1490 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1491 && l
->l_info
[DT_SONAME
] != NULL
)
1492 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1493 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1496 /* Auditing checkpoint: we have a new object. */
1497 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1498 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1500 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1501 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1503 if (afct
->objopen
!= NULL
)
1505 l
->l_audit
[cnt
].bindflags
1506 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1508 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1519 /* Print search path. */
1521 print_search_path (struct r_search_path_elem
**list
,
1522 const char *what
, const char *name
)
1524 char buf
[max_dirnamelen
+ max_capstrlen
];
1527 _dl_debug_printf (" search path=");
1529 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1531 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1534 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1535 if ((*list
)->status
[cnt
] != nonexisting
)
1537 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1538 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1543 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1551 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1552 name
[0] ? name
: rtld_progname
);
1554 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1557 /* Open a file and verify it is an ELF file for this architecture. We
1558 ignore only ELF files for other architectures. Non-ELF files and
1559 ELF files with different header information cause fatal errors since
1560 this could mean there is something wrong in the installation and the
1561 user might want to know about this. */
1563 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1564 int whatcode
, bool *found_other_class
, bool free_name
)
1566 /* This is the expected ELF header. */
1567 #define ELF32_CLASS ELFCLASS32
1568 #define ELF64_CLASS ELFCLASS64
1569 #ifndef VALID_ELF_HEADER
1570 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1571 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1572 # define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
1573 #elif defined MORE_ELF_HEADER_DATA
1574 MORE_ELF_HEADER_DATA
;
1576 static const unsigned char expected
[EI_PAD
] =
1578 [EI_MAG0
] = ELFMAG0
,
1579 [EI_MAG1
] = ELFMAG1
,
1580 [EI_MAG2
] = ELFMAG2
,
1581 [EI_MAG3
] = ELFMAG3
,
1582 [EI_CLASS
] = ELFW(CLASS
),
1583 [EI_DATA
] = byteorder
,
1584 [EI_VERSION
] = EV_CURRENT
,
1585 [EI_OSABI
] = ELFOSABI_SYSV
,
1590 ElfW(Word
) vendorlen
;
1594 } expected_note
= { 4, 16, 1, "GNU" };
1595 /* Initialize it to make the compiler happy. */
1596 const char *errstring
= NULL
;
1600 /* Give the auditing libraries a chance. */
1601 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1602 && loader
->l_auditing
== 0)
1604 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1605 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1607 if (afct
->objsearch
!= NULL
)
1609 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1612 /* Ignore the path. */
1621 /* Open the file. We always open files read-only. */
1622 int fd
= __open (name
, O_RDONLY
);
1626 ElfW(Phdr
) *phdr
, *ph
;
1627 ElfW(Word
) *abi_note
;
1628 unsigned int osversion
;
1631 /* We successfully openened the file. Now verify it is a file
1634 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1636 /* This is where the ELF header is loaded. */
1637 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1638 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1640 /* Now run the tests. */
1641 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1644 errstring
= (errval
== 0
1645 ? N_("file too short") : N_("cannot read file data"));
1649 char *realname
= (char *) name
;
1650 name
= strdupa (realname
);
1653 lose (errval
, fd
, name
, NULL
, NULL
, errstring
, NULL
);
1656 /* See whether the ELF header is what we expect. */
1657 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1659 || !VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1660 ehdr
->e_ident
[EI_ABIVERSION
]),
1663 /* Something is wrong. */
1664 const Elf32_Word
*magp
= (const void *) ehdr
->e_ident
;
1666 #if BYTE_ORDER == LITTLE_ENDIAN
1667 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1668 (ELFMAG1
<< (EI_MAG1
* 8)) |
1669 (ELFMAG2
<< (EI_MAG2
* 8)) |
1670 (ELFMAG3
<< (EI_MAG3
* 8)))
1672 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1673 (ELFMAG1
<< (EI_MAG2
* 8)) |
1674 (ELFMAG2
<< (EI_MAG1
* 8)) |
1675 (ELFMAG3
<< (EI_MAG0
* 8)))
1678 errstring
= N_("invalid ELF header");
1679 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1681 /* This is not a fatal error. On architectures where
1682 32-bit and 64-bit binaries can be run this might
1684 *found_other_class
= true;
1687 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1689 if (BYTE_ORDER
== BIG_ENDIAN
)
1690 errstring
= N_("ELF file data encoding not big-endian");
1692 errstring
= N_("ELF file data encoding not little-endian");
1694 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1696 = N_("ELF file version ident does not match current one");
1697 /* XXX We should be able so set system specific versions which are
1699 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1700 errstring
= N_("ELF file OS ABI invalid");
1701 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_OSABI
],
1702 ehdr
->e_ident
[EI_ABIVERSION
]))
1703 errstring
= N_("ELF file ABI version invalid");
1705 /* Otherwise we don't know what went wrong. */
1706 errstring
= N_("internal error");
1711 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1713 errstring
= N_("ELF file version does not match current one");
1716 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1718 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1719 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1721 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1724 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1725 != sizeof (ElfW(Phdr
)))
1727 errstring
= N_("ELF file's phentsize not the expected size");
1731 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1732 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1733 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1736 phdr
= alloca (maplength
);
1737 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1738 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1742 errstring
= N_("cannot read file data");
1747 /* Check .note.ABI-tag if present. */
1748 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1749 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
>= 32 && ph
->p_align
>= 4)
1751 ElfW(Addr
) size
= ph
->p_filesz
;
1753 if (ph
->p_offset
+ size
<= (size_t) fbp
->len
)
1754 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1757 abi_note
= alloca (size
);
1758 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1759 if (__libc_read (fd
, (void *) abi_note
, size
) != size
)
1763 while (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1765 #define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
1766 ElfW(Addr
) note_size
= 3 * sizeof (ElfW(Word
))
1767 + ROUND (abi_note
[0])
1768 + ROUND (abi_note
[1]);
1770 if (size
- 32 < note_size
)
1776 abi_note
= (void *) abi_note
+ note_size
;
1782 osversion
= (abi_note
[5] & 0xff) * 65536
1783 + (abi_note
[6] & 0xff) * 256
1784 + (abi_note
[7] & 0xff);
1785 if (abi_note
[4] != __ABI_TAG_OS
1786 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1790 __set_errno (ENOENT
);
1801 /* Try to open NAME in one of the directories in *DIRSP.
1802 Return the fd, or -1. If successful, fill in *REALNAME
1803 with the malloc'd full directory name. If it turns out
1804 that none of the directories in *DIRSP exists, *DIRSP is
1805 replaced with (void *) -1, and the old value is free()d
1806 if MAY_FREE_DIRS is true. */
1809 open_path (const char *name
, size_t namelen
, int preloaded
,
1810 struct r_search_path_struct
*sps
, char **realname
,
1811 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
,
1812 bool *found_other_class
)
1814 struct r_search_path_elem
**dirs
= sps
->dirs
;
1817 const char *current_what
= NULL
;
1820 if (__builtin_expect (dirs
== NULL
, 0))
1821 /* We're called before _dl_init_paths when loading the main executable
1822 given on the command line when rtld is run directly. */
1825 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1828 struct r_search_path_elem
*this_dir
= *dirs
;
1835 /* If we are debugging the search for libraries print the path
1836 now if it hasn't happened now. */
1837 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1838 && current_what
!= this_dir
->what
)
1840 current_what
= this_dir
->what
;
1841 print_search_path (dirs
, current_what
, this_dir
->where
);
1844 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1845 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1847 /* Skip this directory if we know it does not exist. */
1848 if (this_dir
->status
[cnt
] == nonexisting
)
1852 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1857 /* Print name we try if this is wanted. */
1858 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1859 _dl_debug_printf (" trying file=%s\n", buf
);
1861 fd
= open_verify (buf
, fbp
, loader
, whatcode
, found_other_class
,
1863 if (this_dir
->status
[cnt
] == unknown
)
1866 this_dir
->status
[cnt
] = existing
;
1867 /* Do not update the directory information when loading
1868 auditing code. We must try to disturb the program as
1869 little as possible. */
1870 else if (loader
== NULL
1871 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_auditing
== 0)
1873 /* We failed to open machine dependent library. Let's
1874 test whether there is any directory at all. */
1877 buf
[buflen
- namelen
- 1] = '\0';
1879 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1880 || ! S_ISDIR (st
.st_mode
))
1881 /* The directory does not exist or it is no directory. */
1882 this_dir
->status
[cnt
] = nonexisting
;
1884 this_dir
->status
[cnt
] = existing
;
1888 /* Remember whether we found any existing directory. */
1889 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1891 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1892 && INTUSE(__libc_enable_secure
))
1894 /* This is an extra security effort to make sure nobody can
1895 preload broken shared objects which are in the trusted
1896 directories and so exploit the bugs. */
1899 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1900 || (st
.st_mode
& S_ISUID
) == 0)
1902 /* The shared object cannot be tested for being SUID
1903 or this bit is not set. In this case we must not
1907 /* We simply ignore the file, signal this by setting
1908 the error value which would have been set by `open'. */
1916 *realname
= (char *) malloc (buflen
);
1917 if (*realname
!= NULL
)
1919 memcpy (*realname
, buf
, buflen
);
1924 /* No memory for the name, we certainly won't be able
1925 to load and link it. */
1930 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1931 /* The file exists and is readable, but something went wrong. */
1934 /* Remember whether we found anything. */
1937 while (*++dirs
!= NULL
);
1939 /* Remove the whole path if none of the directories exists. */
1940 if (__builtin_expect (! any
, 0))
1942 /* Paths which were allocated using the minimal malloc() in ld.so
1943 must not be freed using the general free() in libc. */
1947 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1949 if (sps
!= &rtld_search_dirs
)
1950 sps
->dirs
= (void *) -1;
1956 /* Map in the shared object file NAME. */
1960 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1961 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1970 assert (nsid
< GL(dl_nns
));
1972 /* Look for this name among those already loaded. */
1973 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1975 /* If the requested name matches the soname of a loaded object,
1976 use that object. Elide this check for names that have not
1978 if (__builtin_expect (l
->l_faked
, 0) != 0
1979 || __builtin_expect (l
->l_removed
, 0) != 0)
1981 if (!_dl_name_match_p (name
, l
))
1985 if (__builtin_expect (l
->l_soname_added
, 1)
1986 || l
->l_info
[DT_SONAME
] == NULL
)
1989 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1990 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1991 if (strcmp (name
, soname
) != 0)
1994 /* We have a match on a new name -- cache it. */
1995 add_name_to_object (l
, soname
);
1996 l
->l_soname_added
= 1;
1999 /* We have a match. */
2003 /* Display information if we are debugging. */
2004 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
2006 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
2008 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
2011 /* Give the auditing libraries a chance to change the name before we
2013 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
2014 && (loader
== NULL
|| loader
->l_auditing
== 0))
2016 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2017 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2019 if (afct
->objsearch
!= NULL
)
2021 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
2025 /* Do not try anything further. */
2036 /* Will be true if we found a DSO which is of the other ELF class. */
2037 bool found_other_class
= false;
2039 if (strchr (name
, '/') == NULL
)
2041 /* Search for NAME in several places. */
2043 size_t namelen
= strlen (name
) + 1;
2045 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2046 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
2050 /* When the object has the RUNPATH information we don't use any
2052 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
2054 /* This is the executable's map (if there is one). Make sure that
2055 we do not look at it twice. */
2056 struct link_map
*main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2057 bool did_main_map
= false;
2059 /* First try the DT_RPATH of the dependent object that caused NAME
2060 to be loaded. Then that object's dependent, and on up. */
2061 for (l
= loader
; l
; l
= l
->l_loader
)
2062 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2064 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2065 &realname
, &fb
, loader
, LA_SER_RUNPATH
,
2066 &found_other_class
);
2070 did_main_map
|= l
== main_map
;
2073 /* If dynamically linked, try the DT_RPATH of the executable
2074 itself. NB: we do this for lookups in any namespace. */
2075 if (fd
== -1 && !did_main_map
2076 && main_map
!= NULL
&& main_map
->l_type
!= lt_loaded
2077 && cache_rpath (main_map
, &main_map
->l_rpath_dirs
, DT_RPATH
,
2079 fd
= open_path (name
, namelen
, preloaded
, &main_map
->l_rpath_dirs
,
2080 &realname
, &fb
, loader
?: main_map
, LA_SER_RUNPATH
,
2081 &found_other_class
);
2084 /* Try the LD_LIBRARY_PATH environment variable. */
2085 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2086 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2088 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2089 LA_SER_LIBPATH
, &found_other_class
);
2091 /* Look at the RUNPATH information for this binary. */
2092 if (fd
== -1 && loader
!= NULL
2093 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2094 DT_RUNPATH
, "RUNPATH"))
2095 fd
= open_path (name
, namelen
, preloaded
,
2096 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2097 LA_SER_RUNPATH
, &found_other_class
);
2100 && (__builtin_expect (! preloaded
, 1)
2101 || ! INTUSE(__libc_enable_secure
)))
2103 /* Check the list of libraries in the file /etc/ld.so.cache,
2104 for compatibility with Linux's ldconfig program. */
2105 const char *cached
= _dl_load_cache_lookup (name
);
2110 // XXX Correct to unconditionally default to namespace 0?
2111 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2116 /* If the loader has the DF_1_NODEFLIB flag set we must not
2117 use a cache entry from any of these directories. */
2120 /* 'l' is always != NULL for dynamically linked objects. */
2123 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2125 const char *dirp
= system_dirs
;
2126 unsigned int cnt
= 0;
2130 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2132 /* The prefix matches. Don't use the entry. */
2137 dirp
+= system_dirs_len
[cnt
] + 1;
2140 while (cnt
< nsystem_dirs_len
);
2145 fd
= open_verify (cached
,
2146 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2147 LA_SER_CONFIG
, &found_other_class
, false);
2148 if (__builtin_expect (fd
!= -1, 1))
2150 realname
= local_strdup (cached
);
2151 if (realname
== NULL
)
2161 /* Finally, try the default path. */
2163 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2164 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2165 && rtld_search_dirs
.dirs
!= (void *) -1)
2166 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2167 &realname
, &fb
, l
, LA_SER_DEFAULT
, &found_other_class
);
2169 /* Add another newline when we are tracing the library loading. */
2170 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2171 _dl_debug_printf ("\n");
2175 /* The path may contain dynamic string tokens. */
2177 ? expand_dynamic_string_token (loader
, name
)
2178 : local_strdup (name
));
2179 if (realname
== NULL
)
2183 fd
= open_verify (realname
, &fb
,
2184 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0,
2185 &found_other_class
, true);
2186 if (__builtin_expect (fd
, 0) == -1)
2194 /* In case the LOADER information has only been provided to get to
2195 the appropriate RUNPATH/RPATH information we do not need it
2197 if (mode
& __RTLD_CALLMAP
)
2200 if (__builtin_expect (fd
, 0) == -1)
2203 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2205 /* We haven't found an appropriate library. But since we
2206 are only interested in the list of libraries this isn't
2207 so severe. Fake an entry with all the information we
2209 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2211 /* Enter the new object in the list of loaded objects. */
2212 if ((name_copy
= local_strdup (name
)) == NULL
2213 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2214 mode
, nsid
)) == NULL
)
2217 _dl_signal_error (ENOMEM
, name
, NULL
,
2218 N_("cannot create shared object descriptor"));
2220 /* Signal that this is a faked entry. */
2222 /* Since the descriptor is initialized with zero we do not
2224 l->l_reserved = 0; */
2225 l
->l_buckets
= &dummy_bucket
;
2231 else if (found_other_class
)
2232 _dl_signal_error (0, name
, NULL
,
2233 ELFW(CLASS
) == ELFCLASS32
2234 ? N_("wrong ELF class: ELFCLASS64")
2235 : N_("wrong ELF class: ELFCLASS32"));
2237 _dl_signal_error (errno
, name
, NULL
,
2238 N_("cannot open shared object file"));
2241 void *stack_end
= __libc_stack_end
;
2242 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2249 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2257 unsigned int idx
= 0;
2258 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2259 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2260 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2262 if (sps
->dirs
!= (void *) -1)
2264 struct r_search_path_elem
**dirs
= sps
->dirs
;
2267 const struct r_search_path_elem
*const r
= *dirs
++;
2271 si
->dls_size
+= MAX (2, r
->dirnamelen
);
2275 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2276 sp
->dls_name
= allocptr
;
2277 if (r
->dirnamelen
< 2)
2278 *allocptr
++ = r
->dirnamelen
? '/' : '.';
2280 allocptr
= __mempcpy (allocptr
,
2281 r
->dirname
, r
->dirnamelen
- 1);
2283 sp
->dls_flags
= flags
;
2286 while (*dirs
!= NULL
);
2290 /* When the object has the RUNPATH information we don't use any RPATHs. */
2291 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2293 /* First try the DT_RPATH of the dependent object that caused NAME
2294 to be loaded. Then that object's dependent, and on up. */
2296 struct link_map
*l
= loader
;
2299 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2300 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2305 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2306 if (loader
->l_ns
== LM_ID_BASE
)
2308 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2309 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2310 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2311 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2315 /* Try the LD_LIBRARY_PATH environment variable. */
2316 add_path (&env_path_list
, XXX_ENV
);
2318 /* Look at the RUNPATH information for this binary. */
2319 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2320 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2323 Here is where ld.so.cache gets checked, but we don't have
2324 a way to indicate that in the results for Dl_serinfo. */
2326 /* Finally, try the default path. */
2327 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2328 add_path (&rtld_search_dirs
, XXX_default
);
2331 /* Count the struct size before the string area, which we didn't
2332 know before we completed dls_cnt. */
2333 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;