1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004 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 <dl-osinfo.h>
37 #include <stackinfo.h>
43 /* On some systems, no flag bits are given to specify file mapping. */
48 /* The right way to map in the shared library files is MAP_COPY, which
49 makes a virtual copy of the data at the time of the mmap call; this
50 guarantees the mapped pages will be consistent even if the file is
51 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
52 get is MAP_PRIVATE, which copies each page when it is modified; this
53 means if the file is overwritten, we may at some point get some pages
54 from the new version after starting with pages from the old version. */
56 # define MAP_COPY MAP_PRIVATE
59 /* We want to prevent people from modifying DSOs which are currently in
60 use. This is what MAP_DENYWRITE is for. */
62 # define MAP_DENYWRITE 0
65 /* Some systems link their relocatable objects for another base address
66 than 0. We want to know the base address for these such that we can
67 subtract this address from the segment addresses during mapping.
68 This results in a more efficient address space usage. Defaults to
69 zero for almost all systems. */
71 # define MAP_BASE_ADDR(l) 0
76 #if BYTE_ORDER == BIG_ENDIAN
77 # define byteorder ELFDATA2MSB
78 #elif BYTE_ORDER == LITTLE_ENDIAN
79 # define byteorder ELFDATA2LSB
81 # error "Unknown BYTE_ORDER " BYTE_ORDER
82 # define byteorder ELFDATANONE
85 #define STRING(x) __STRING (x)
88 /* The fd is not examined when using MAP_ANON. */
92 # define ANONFD _dl_zerofd
95 /* Handle situations where we have a preferred location in memory for
96 the shared objects. */
97 #ifdef ELF_PREFERRED_ADDRESS_DATA
98 ELF_PREFERRED_ADDRESS_DATA
;
100 #ifndef ELF_PREFERRED_ADDRESS
101 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
103 #ifndef ELF_FIXED_ADDRESS
104 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
108 int __stack_prot attribute_hidden attribute_relro
109 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
111 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
116 /* Type for the buffer we put the ELF header and hopefully the program
117 header. This buffer does not really have to be too large. In most
118 cases the program header follows the ELF header directly. If this
119 is not the case all bets are off and we can make the header
120 arbitrarily large and still won't get it read. This means the only
121 question is how large are the ELF and program header combined. The
122 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
123 bytes long. Each program header entry is again 32 and 56 bytes
124 long respectively. I.e., even with a file which has 7 program
125 header entries we only have to read 512B. Add to this a bit of
126 margin for program notes and reading 512B and 640B for 32-bit and
127 64-bit files respecitvely is enough. If this heuristic should
128 really fail for some file the code in `_dl_map_object_from_fd'
129 knows how to recover. */
134 # define FILEBUF_SIZE 512
136 # define FILEBUF_SIZE 640
138 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
141 /* This is the decomposed LD_LIBRARY_PATH search path. */
142 static struct r_search_path_struct env_path_list attribute_relro
;
144 /* List of the hardware capabilities we might end up using. */
145 static const struct r_strlenpair
*capstr attribute_relro
;
146 static size_t ncapstr attribute_relro
;
147 static size_t max_capstrlen attribute_relro
;
150 /* Get the generated information about the trusted directories. */
151 #include "trusted-dirs.h"
153 static const char system_dirs
[] = SYSTEM_DIRS
;
154 static const size_t system_dirs_len
[] =
158 #define nsystem_dirs_len \
159 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
162 /* Local version of `strdup' function. */
164 local_strdup (const char *s
)
166 size_t len
= strlen (s
) + 1;
167 void *new = malloc (len
);
172 return (char *) memcpy (new, s
, len
);
177 is_dst (const char *start
, const char *name
, const char *str
,
178 int is_path
, int secure
)
181 bool is_curly
= false;
190 while (name
[len
] == str
[len
] && name
[len
] != '\0')
195 if (name
[len
] != '}')
198 /* Point again at the beginning of the name. */
200 /* Skip over closing curly brace and adjust for the --name. */
203 else if (name
[len
] != '\0' && name
[len
] != '/'
204 && (!is_path
|| name
[len
] != ':'))
207 if (__builtin_expect (secure
, 0)
208 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
209 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
217 _dl_dst_count (const char *name
, int is_path
)
219 const char *const start
= name
;
226 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
227 is $ORIGIN alone) and it must always appear first in path. */
229 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
230 INTUSE(__libc_enable_secure
))) != 0
231 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
232 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
235 name
= strchr (name
+ len
, '$');
237 while (name
!= NULL
);
244 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
247 const char *const start
= name
;
248 char *last_elem
, *wp
;
250 /* Now fill the result path. While copying over the string we keep
251 track of the start of the last path element. When we come accross
252 a DST we copy over the value or (if the value is not available)
253 leave the entire path element out. */
254 last_elem
= wp
= result
;
258 if (__builtin_expect (*name
== '$', 0))
260 const char *repl
= NULL
;
264 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
265 INTUSE(__libc_enable_secure
))) != 0)
267 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
268 repl
= GLRO(dl_platform
);
269 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
272 if (repl
!= NULL
&& repl
!= (const char *) -1)
274 wp
= __stpcpy (wp
, repl
);
279 /* We cannot use this path element, the value of the
280 replacement is unknown. */
283 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
287 /* No DST we recognize. */
293 if (is_path
&& *name
== ':')
297 while (*name
!= '\0');
305 /* Return copy of argument with all recognized dynamic string tokens
306 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
307 might not be possible to determine the path from which the object
308 belonging to the map is loaded. In this case the path element
309 containing $ORIGIN is left out. */
311 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
313 /* We make two runs over the string. First we determine how large the
314 resulting string is and then we copy it over. Since this is now
315 frequently executed operation we are looking here not for performance
316 but rather for code size. */
321 /* Determine the number of DST elements. */
322 cnt
= DL_DST_COUNT (s
, 1);
324 /* If we do not have to replace anything simply copy the string. */
325 if (__builtin_expect (cnt
, 0) == 0)
326 return local_strdup (s
);
328 /* Determine the length of the substituted string. */
329 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
331 /* Allocate the necessary memory. */
332 result
= (char *) malloc (total
+ 1);
336 return _dl_dst_substitute (l
, s
, result
, 1);
340 /* Add `name' to the list of names for a particular shared object.
341 `name' is expected to have been allocated with malloc and will
342 be freed if the shared object already has this name.
343 Returns false if the object already had this name. */
346 add_name_to_object (struct link_map
*l
, const char *name
)
348 struct libname_list
*lnp
, *lastp
;
349 struct libname_list
*newname
;
353 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
354 if (strcmp (name
, lnp
->name
) == 0)
357 name_len
= strlen (name
) + 1;
358 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
361 /* No more memory. */
362 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
365 /* The object should have a libname set from _dl_new_object. */
366 assert (lastp
!= NULL
);
368 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
369 newname
->next
= NULL
;
370 newname
->dont_free
= 0;
371 lastp
->next
= newname
;
374 /* Standard search directories. */
375 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
377 static size_t max_dirnamelen
;
379 static struct r_search_path_elem
**
380 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
381 int check_trusted
, const char *what
, const char *where
)
386 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
388 struct r_search_path_elem
*dirp
;
389 size_t len
= strlen (cp
);
391 /* `strsep' can pass an empty string. This has to be
392 interpreted as `use the current directory'. */
395 static const char curwd
[] = "./";
399 /* Remove trailing slashes (except for "/"). */
400 while (len
> 1 && cp
[len
- 1] == '/')
403 /* Now add one if there is none so far. */
404 if (len
> 0 && cp
[len
- 1] != '/')
407 /* Make sure we don't use untrusted directories if we run SUID. */
408 if (__builtin_expect (check_trusted
, 0))
410 const char *trun
= system_dirs
;
414 /* All trusted directories must be complete names. */
417 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
419 if (len
== system_dirs_len
[idx
]
420 && memcmp (trun
, cp
, len
) == 0)
427 trun
+= system_dirs_len
[idx
] + 1;
432 /* Simply drop this directory. */
436 /* See if this directory is already known. */
437 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
438 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
443 /* It is available, see whether it's on our own list. */
445 for (cnt
= 0; cnt
< nelems
; ++cnt
)
446 if (result
[cnt
] == dirp
)
450 result
[nelems
++] = dirp
;
455 enum r_dir_status init_val
;
456 size_t where_len
= where
? strlen (where
) + 1 : 0;
458 /* It's a new directory. Create an entry and add it. */
459 dirp
= (struct r_search_path_elem
*)
460 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
461 + where_len
+ len
+ 1);
463 _dl_signal_error (ENOMEM
, NULL
, NULL
,
464 N_("cannot create cache for search path"));
466 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
467 + ncapstr
* sizeof (enum r_dir_status
));
468 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
469 dirp
->dirnamelen
= len
;
471 if (len
> max_dirnamelen
)
472 max_dirnamelen
= len
;
474 /* We have to make sure all the relative directories are
475 never ignored. The current directory might change and
476 all our saved information would be void. */
477 init_val
= cp
[0] != '/' ? existing
: unknown
;
478 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
479 dirp
->status
[cnt
] = init_val
;
482 if (__builtin_expect (where
!= NULL
, 1))
483 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
484 + (ncapstr
* sizeof (enum r_dir_status
)),
489 dirp
->next
= GL(dl_all_dirs
);
490 GL(dl_all_dirs
) = dirp
;
492 /* Put it in the result array. */
493 result
[nelems
++] = dirp
;
497 /* Terminate the array. */
498 result
[nelems
] = NULL
;
506 decompose_rpath (struct r_search_path_struct
*sps
,
507 const char *rpath
, struct link_map
*l
, const char *what
)
509 /* Make a copy we can work with. */
510 const char *where
= l
->l_name
;
513 struct r_search_path_elem
**result
;
515 /* Initialize to please the compiler. */
516 const char *errstring
= NULL
;
518 /* First see whether we must forget the RUNPATH and RPATH from this
520 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
521 && !INTUSE(__libc_enable_secure
))
523 const char *inhp
= GLRO(dl_inhibit_rpath
);
527 const char *wp
= where
;
529 while (*inhp
== *wp
&& *wp
!= '\0')
535 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
537 /* This object is on the list of objects for which the
538 RUNPATH and RPATH must not be used. */
539 result
= calloc (1, sizeof *result
);
543 errstring
= N_("cannot create cache for search path");
545 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
554 while (*inhp
!= '\0')
558 while (*inhp
!= '\0');
561 /* Make a writable copy. At the same time expand possible dynamic
563 copy
= expand_dynamic_string_token (l
, rpath
);
566 errstring
= N_("cannot create RUNPATH/RPATH copy");
570 /* Count the number of necessary elements in the result array. */
572 for (cp
= copy
; *cp
!= '\0'; ++cp
)
576 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
577 number of necessary entries. */
578 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
581 goto signal_error_cache
;
583 fillin_rpath (copy
, result
, ":", 0, what
, where
);
585 /* Free the copied RPATH string. `fillin_rpath' make own copies if
590 /* The caller will change this value if we haven't used a real malloc. */
594 /* Make sure cached path information is stored in *SP
595 and return true if there are any paths to search there. */
597 cache_rpath (struct link_map
*l
,
598 struct r_search_path_struct
*sp
,
602 if (sp
->dirs
== (void *) -1)
605 if (sp
->dirs
!= NULL
)
608 if (l
->l_info
[tag
] == NULL
)
610 /* There is no path. */
611 sp
->dirs
= (void *) -1;
615 /* Make sure the cache information is available. */
616 decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
617 + l
->l_info
[tag
]->d_un
.d_val
),
625 _dl_init_paths (const char *llp
)
629 struct r_search_path_elem
*pelem
, **aelem
;
634 /* Initialize to please the compiler. */
635 const char *errstring
= NULL
;
637 /* Fill in the information about the application's RPATH and the
638 directories addressed by the LD_LIBRARY_PATH environment variable. */
640 /* Get the capabilities. */
641 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
642 &ncapstr
, &max_capstrlen
);
644 /* First set up the rest of the default search directory entries. */
645 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
646 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
647 if (rtld_search_dirs
.dirs
== NULL
)
649 errstring
= N_("cannot create search path array");
651 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
654 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
655 + ncapstr
* sizeof (enum r_dir_status
))
656 / sizeof (struct r_search_path_elem
));
658 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
659 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
660 * round_size
* sizeof (struct r_search_path_elem
));
661 if (rtld_search_dirs
.dirs
[0] == NULL
)
663 errstring
= N_("cannot create cache for search path");
667 rtld_search_dirs
.malloced
= 0;
668 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
678 pelem
->what
= "system search path";
681 pelem
->dirname
= strp
;
682 pelem
->dirnamelen
= system_dirs_len
[idx
];
683 strp
+= system_dirs_len
[idx
] + 1;
685 /* System paths must be absolute. */
686 assert (pelem
->dirname
[0] == '/');
687 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
688 pelem
->status
[cnt
] = unknown
;
690 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
694 while (idx
< nsystem_dirs_len
);
696 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
700 /* This points to the map of the main object. */
701 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
704 assert (l
->l_type
!= lt_loaded
);
706 if (l
->l_info
[DT_RUNPATH
])
708 /* Allocate room for the search path and fill in information
710 decompose_rpath (&l
->l_runpath_dirs
,
711 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
712 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
715 /* The RPATH is ignored. */
716 l
->l_rpath_dirs
.dirs
= (void *) -1;
720 l
->l_runpath_dirs
.dirs
= (void *) -1;
722 if (l
->l_info
[DT_RPATH
])
724 /* Allocate room for the search path and fill in information
726 decompose_rpath (&l
->l_rpath_dirs
,
727 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
728 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
730 l
->l_rpath_dirs
.malloced
= 0;
733 l
->l_rpath_dirs
.dirs
= (void *) -1;
738 if (llp
!= NULL
&& *llp
!= '\0')
741 const char *cp
= llp
;
742 char *llp_tmp
= strdupa (llp
);
744 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
749 if (*cp
== ':' || *cp
== ';')
754 env_path_list
.dirs
= (struct r_search_path_elem
**)
755 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
756 if (env_path_list
.dirs
== NULL
)
758 errstring
= N_("cannot create cache for search path");
762 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
763 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
766 if (env_path_list
.dirs
[0] == NULL
)
768 free (env_path_list
.dirs
);
769 env_path_list
.dirs
= (void *) -1;
772 env_path_list
.malloced
= 0;
775 env_path_list
.dirs
= (void *) -1;
777 /* Remember the last search directory added at startup. */
778 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
783 __attribute__ ((noreturn
, noinline
))
784 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
787 /* The file might already be closed. */
792 /* Remove the stillborn object from the list and free it. */
793 assert (l
->l_next
== NULL
);
794 if (l
->l_prev
== NULL
)
795 /* No other module loaded. This happens only in the static library,
796 or in rtld under --verify. */
797 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
799 l
->l_prev
->l_next
= NULL
;
800 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
804 _dl_signal_error (code
, name
, NULL
, msg
);
808 /* Map in the shared object NAME, actually located in REALNAME, and already
811 #ifndef EXTERNAL_MAP_FROM_FD
815 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
816 char *realname
, struct link_map
*loader
, int l_type
,
817 int mode
, void **stack_endp
, Lmid_t nsid
)
819 struct link_map
*l
= NULL
;
820 const ElfW(Ehdr
) *header
;
821 const ElfW(Phdr
) *phdr
;
822 const ElfW(Phdr
) *ph
;
826 /* Initialize to keep the compiler happy. */
827 const char *errstring
= NULL
;
830 /* Get file information. */
831 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
833 errstring
= N_("cannot stat shared object");
837 lose (errval
, fd
, name
, realname
, l
, errstring
);
840 /* Look again to see if the real name matched another already loaded. */
841 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
842 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
844 /* The object is already loaded.
845 Just bump its reference count and return it. */
848 /* If the name is not in the list of names for this object add
851 add_name_to_object (l
, name
);
857 /* When loading into a namespace other than the base one we must
858 avoid loading ld.so since there can only be one copy. Ever. */
859 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
860 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
861 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
862 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
864 /* This is indeed ld.so. Create a new link_map which refers to
865 the real one for almost everything. */
866 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
870 /* Refer to the real descriptor. */
871 l
->l_real
= &GL(dl_rtld_map
);
873 /* No need to bump the refcount of the real object, ld.so will
874 never be unloaded. */
881 if (mode
& RTLD_NOLOAD
)
882 /* We are not supposed to load the object unless it is already
883 loaded. So return now. */
886 /* Print debugging message. */
887 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
888 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
890 /* This is the ELF header. We read it in `open_verify'. */
891 header
= (void *) fbp
->buf
;
895 if (_dl_zerofd
== -1)
897 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
898 if (_dl_zerofd
== -1)
901 _dl_signal_error (errno
, NULL
, NULL
,
902 N_("cannot open zero fill device"));
907 /* Enter the new object in the list of loaded objects. */
908 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
909 if (__builtin_expect (l
== NULL
, 0))
914 errstring
= N_("cannot create shared object descriptor");
915 goto call_lose_errno
;
918 /* Extract the remaining details we need from the ELF header
919 and then read in the program header table. */
920 l
->l_entry
= header
->e_entry
;
921 type
= header
->e_type
;
922 l
->l_phnum
= header
->e_phnum
;
924 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
925 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
926 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
929 phdr
= alloca (maplength
);
930 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
931 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
933 errstring
= N_("cannot read file data");
934 goto call_lose_errno
;
938 /* Presumed absent PT_GNU_STACK. */
939 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
942 /* Scan the program header table, collecting its load commands. */
945 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
948 } loadcmds
[l
->l_phnum
], *c
;
949 size_t nloadcmds
= 0;
950 bool has_holes
= false;
952 /* The struct is initialized to zero so this is not necessary:
956 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
959 /* These entries tell us where to find things once the file's
960 segments are mapped in. We record the addresses it says
961 verbatim, and later correct for the run-time load address. */
963 l
->l_ld
= (void *) ph
->p_vaddr
;
964 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
968 l
->l_phdr
= (void *) ph
->p_vaddr
;
972 /* A load command tells us to map in part of the file.
973 We record the load commands and process them all later. */
974 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
977 errstring
= N_("ELF load command alignment not page-aligned");
980 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
981 & (ph
->p_align
- 1)) != 0, 0))
984 = N_("ELF load command address/offset not properly aligned");
988 c
= &loadcmds
[nloadcmds
++];
989 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
990 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
991 & ~(GLRO(dl_pagesize
) - 1));
992 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
993 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
994 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
996 /* Determine whether there is a gap between the last segment
998 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1001 /* Optimize a common case. */
1002 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1003 c
->prot
= (PF_TO_PROT
1004 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1007 if (ph
->p_flags
& PF_R
)
1008 c
->prot
|= PROT_READ
;
1009 if (ph
->p_flags
& PF_W
)
1010 c
->prot
|= PROT_WRITE
;
1011 if (ph
->p_flags
& PF_X
)
1012 c
->prot
|= PROT_EXEC
;
1018 if (ph
->p_memsz
== 0)
1019 /* Nothing to do for an empty segment. */
1022 l
->l_tls_blocksize
= ph
->p_memsz
;
1023 l
->l_tls_align
= ph
->p_align
;
1024 if (ph
->p_align
== 0)
1025 l
->l_tls_firstbyte_offset
= 0;
1027 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1028 l
->l_tls_initimage_size
= ph
->p_filesz
;
1029 /* Since we don't know the load address yet only store the
1030 offset. We will adjust it later. */
1031 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1033 /* If not loading the initial set of shared libraries,
1034 check whether we should permit loading a TLS segment. */
1035 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1036 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1037 not set up TLS data structures, so don't use them now. */
1038 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1040 /* Assign the next available module ID. */
1041 l
->l_tls_modid
= _dl_next_tls_modid ();
1046 if (l
->l_prev
== NULL
)
1047 /* We are loading the executable itself when the dynamic linker
1048 was executed directly. The setup will happen later. */
1051 /* In a static binary there is no way to tell if we dynamically
1052 loaded libpthread. */
1053 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1056 /* We have not yet loaded libpthread.
1057 We can do the TLS setup right now! */
1061 /* The first call allocates TLS bookkeeping data structures.
1062 Then we allocate the TCB for the initial thread. */
1063 if (__builtin_expect (_dl_tls_setup (), 0)
1064 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1069 cannot allocate TLS data structures for initial thread");
1073 /* Now we install the TCB in the thread register. */
1074 errstring
= TLS_INIT_TP (tcb
, 0);
1075 if (__builtin_expect (errstring
== NULL
, 1))
1077 /* Now we are all good. */
1078 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1082 /* The kernel is too old or somesuch. */
1084 _dl_deallocate_tls (tcb
, 1);
1089 /* Uh-oh, the binary expects TLS support but we cannot
1092 errstring
= N_("cannot handle TLS data");
1097 stack_flags
= ph
->p_flags
;
1101 l
->l_relro_addr
= ph
->p_vaddr
;
1102 l
->l_relro_size
= ph
->p_memsz
;
1106 if (__builtin_expect (nloadcmds
== 0, 0))
1108 /* This only happens for a bogus object that will be caught with
1109 another error below. But we don't want to go through the
1110 calculations below using NLOADCMDS - 1. */
1111 errstring
= N_("object file has no loadable segments");
1115 /* Now process the load commands and map segments into memory. */
1118 /* Length of the sections to be loaded. */
1119 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1121 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1123 /* This is a position-independent shared object. We can let the
1124 kernel map it anywhere it likes, but we must have space for all
1125 the segments in their specified positions relative to the first.
1126 So we map the first segment without MAP_FIXED, but with its
1127 extent increased to cover all the segments. Then we remove
1128 access from excess portion, and there is known sufficient space
1129 there to remap from the later segments.
1131 As a refinement, sometimes we have an address that we would
1132 prefer to map such objects at; but this is only a preference,
1133 the OS can do whatever it likes. */
1135 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1136 c
->mapstart
& GLRO(dl_use_load_bias
))
1137 - MAP_BASE_ADDR (l
));
1139 /* Remember which part of the address space this object uses. */
1140 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1142 MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1144 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1147 errstring
= N_("failed to map segment from shared object");
1148 goto call_lose_errno
;
1151 l
->l_map_end
= l
->l_map_start
+ maplength
;
1152 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1155 /* Change protection on the excess portion to disallow all access;
1156 the portions we do not remap later will be inaccessible as if
1157 unallocated. Then jump into the normal segment-mapping loop to
1158 handle the portion of the segment past the end of the file
1160 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1161 loadcmds
[nloadcmds
- 1].allocend
- c
->mapend
,
1167 /* This object is loaded at a fixed address. This must never
1168 happen for objects loaded with dlopen(). */
1169 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1171 errstring
= N_("cannot dynamically load executable");
1175 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1177 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1180 /* Remember which part of the address space this object uses. */
1181 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1182 l
->l_map_end
= l
->l_map_start
+ maplength
;
1184 while (c
< &loadcmds
[nloadcmds
])
1186 if (c
->mapend
> c
->mapstart
1187 /* Map the segment contents from the file. */
1188 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1189 c
->mapend
- c
->mapstart
, c
->prot
,
1190 MAP_FIXED
|MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1196 if (c
->prot
& PROT_EXEC
)
1197 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1200 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1201 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1202 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1203 /* Found the program header in this segment. */
1204 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1206 if (c
->allocend
> c
->dataend
)
1208 /* Extra zero pages should appear at the end of this segment,
1209 after the data mapped from the file. */
1210 ElfW(Addr
) zero
, zeroend
, zeropage
;
1212 zero
= l
->l_addr
+ c
->dataend
;
1213 zeroend
= l
->l_addr
+ c
->allocend
;
1214 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1215 & ~(GLRO(dl_pagesize
) - 1));
1217 if (zeroend
< zeropage
)
1218 /* All the extra data is in the last page of the segment.
1219 We can just zero it. */
1222 if (zeropage
> zero
)
1224 /* Zero the final part of the last page of the segment. */
1225 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1228 if (__mprotect ((caddr_t
) (zero
1229 & ~(GLRO(dl_pagesize
) - 1)),
1230 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1232 errstring
= N_("cannot change memory protections");
1233 goto call_lose_errno
;
1236 memset ((void *) zero
, '\0', zeropage
- zero
);
1237 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1238 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1239 GLRO(dl_pagesize
), c
->prot
);
1242 if (zeroend
> zeropage
)
1244 /* Map the remaining zero pages in from the zero fill FD. */
1246 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1247 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1249 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1251 errstring
= N_("cannot map zero-fill pages");
1252 goto call_lose_errno
;
1263 if (__builtin_expect (type
== ET_DYN
, 0))
1265 errstring
= N_("object file has no dynamic section");
1270 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1272 elf_get_dynamic_info (l
, NULL
);
1274 /* Make sure we are not dlopen'ing an object that has the
1275 DF_1_NOOPEN flag set. */
1276 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1277 && (mode
& __RTLD_DLOPEN
))
1279 /* We are not supposed to load this object. Free all resources. */
1280 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1282 if (!l
->l_libname
->dont_free
)
1283 free (l
->l_libname
);
1285 if (l
->l_phdr_allocated
)
1286 free ((void *) l
->l_phdr
);
1288 errstring
= N_("shared object cannot be dlopen()ed");
1292 if (l
->l_phdr
== NULL
)
1294 /* The program header is not contained in any of the segments.
1295 We have to allocate memory ourself and copy it over from out
1297 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1298 * sizeof (ElfW(Phdr
)));
1301 errstring
= N_("cannot allocate memory for program header");
1302 goto call_lose_errno
;
1305 l
->l_phdr
= memcpy (newp
, phdr
,
1306 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1307 l
->l_phdr_allocated
= 1;
1310 /* Adjust the PT_PHDR value by the runtime load address. */
1311 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1313 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1315 /* The stack is presently not executable, but this module
1316 requires that it be executable. We must change the
1317 protection of the variable which contains the flags used in
1318 the mprotect calls. */
1320 if (mode
& __RTLD_DLOPEN
)
1322 uintptr_t p
= ((uintptr_t) &__stack_prot
) & ~(GLRO(dl_pagesize
) - 1);
1323 size_t s
= (uintptr_t) &__stack_prot
- p
+ sizeof (int);
1325 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1326 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0),
1327 allow_ldso
|allow_libc
) == 0,
1329 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1330 __mprotect ((void *) p
, s
, PROT_READ
);
1334 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1336 #ifdef check_consistency
1337 check_consistency ();
1340 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1344 cannot enable executable stack as shared object requires");
1350 /* Adjust the address of the TLS initialization image. */
1351 if (l
->l_tls_initimage
!= NULL
)
1352 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1355 /* We are done mapping in the file. We no longer need the descriptor. */
1356 if (__builtin_expect (__close (fd
) != 0, 0))
1358 errstring
= N_("cannot close file descriptor");
1359 goto call_lose_errno
;
1361 /* Signal that we closed the file. */
1364 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1365 l
->l_type
= lt_executable
;
1367 l
->l_entry
+= l
->l_addr
;
1369 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1370 _dl_debug_printf ("\
1371 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1372 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1373 (int) sizeof (void *) * 2,
1374 (unsigned long int) l
->l_ld
,
1375 (int) sizeof (void *) * 2,
1376 (unsigned long int) l
->l_addr
,
1377 (int) sizeof (void *) * 2, maplength
,
1378 (int) sizeof (void *) * 2,
1379 (unsigned long int) l
->l_entry
,
1380 (int) sizeof (void *) * 2,
1381 (unsigned long int) l
->l_phdr
,
1382 (int) sizeof (void *) * 2, l
->l_phnum
);
1384 /* Set up the symbol hash table. */
1387 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1388 have to do this for the main map. */
1389 if ((mode
& RTLD_DEEPBIND
) == 0
1390 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1391 && &l
->l_searchlist
!= l
->l_scope
[0])
1393 /* Create an appropriate searchlist. It contains only this map.
1394 This is the definition of DT_SYMBOLIC in SysVr4. */
1395 l
->l_symbolic_searchlist
.r_list
=
1396 (struct link_map
**) malloc (sizeof (struct link_map
*));
1398 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1400 errstring
= N_("cannot create searchlist");
1401 goto call_lose_errno
;
1404 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1405 l
->l_symbolic_searchlist
.r_nlist
= 1;
1407 /* Now move the existing entries one back. */
1408 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1409 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1411 /* Now add the new entry. */
1412 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1415 /* Remember whether this object must be initialized first. */
1416 if (l
->l_flags_1
& DF_1_INITFIRST
)
1417 GL(dl_initfirst
) = l
;
1419 /* Finally the file information. */
1420 l
->l_dev
= st
.st_dev
;
1421 l
->l_ino
= st
.st_ino
;
1423 /* When we profile the SONAME might be needed for something else but
1424 loading. Add it right away. */
1425 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1426 && l
->l_info
[DT_SONAME
] != NULL
)
1427 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1428 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1433 /* Print search path. */
1435 print_search_path (struct r_search_path_elem
**list
,
1436 const char *what
, const char *name
)
1438 char buf
[max_dirnamelen
+ max_capstrlen
];
1441 _dl_debug_printf (" search path=");
1443 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1445 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1448 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1449 if ((*list
)->status
[cnt
] != nonexisting
)
1451 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1452 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1457 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1465 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1466 name
[0] ? name
: rtld_progname
);
1468 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1471 /* Open a file and verify it is an ELF file for this architecture. We
1472 ignore only ELF files for other architectures. Non-ELF files and
1473 ELF files with different header information cause fatal errors since
1474 this could mean there is something wrong in the installation and the
1475 user might want to know about this. */
1477 open_verify (const char *name
, struct filebuf
*fbp
)
1479 /* This is the expected ELF header. */
1480 #define ELF32_CLASS ELFCLASS32
1481 #define ELF64_CLASS ELFCLASS64
1482 #ifndef VALID_ELF_HEADER
1483 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1484 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1485 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1487 static const unsigned char expected
[EI_PAD
] =
1489 [EI_MAG0
] = ELFMAG0
,
1490 [EI_MAG1
] = ELFMAG1
,
1491 [EI_MAG2
] = ELFMAG2
,
1492 [EI_MAG3
] = ELFMAG3
,
1493 [EI_CLASS
] = ELFW(CLASS
),
1494 [EI_DATA
] = byteorder
,
1495 [EI_VERSION
] = EV_CURRENT
,
1496 [EI_OSABI
] = ELFOSABI_SYSV
,
1501 ElfW(Word
) vendorlen
;
1505 } expected_note
= { 4, 16, 1, "GNU" };
1507 /* Initialize it to make the compiler happy. */
1508 const char *errstring
= NULL
;
1511 /* Open the file. We always open files read-only. */
1512 fd
= __open (name
, O_RDONLY
);
1516 ElfW(Phdr
) *phdr
, *ph
;
1517 ElfW(Word
) *abi_note
, abi_note_buf
[8];
1518 unsigned int osversion
;
1521 /* We successfully openened the file. Now verify it is a file
1524 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1526 /* This is where the ELF header is loaded. */
1527 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1528 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1530 /* Now run the tests. */
1531 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1534 errstring
= (errval
== 0
1535 ? N_("file too short") : N_("cannot read file data"));
1537 lose (errval
, fd
, name
, NULL
, NULL
, errstring
);
1540 /* See whether the ELF header is what we expect. */
1541 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1544 /* Something is wrong. */
1545 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1546 #if BYTE_ORDER == LITTLE_ENDIAN
1547 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1548 (ELFMAG1
<< (EI_MAG1
* 8)) |
1549 (ELFMAG2
<< (EI_MAG2
* 8)) |
1550 (ELFMAG3
<< (EI_MAG3
* 8)))
1552 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1553 (ELFMAG1
<< (EI_MAG2
* 8)) |
1554 (ELFMAG2
<< (EI_MAG1
* 8)) |
1555 (ELFMAG3
<< (EI_MAG0
* 8)))
1558 errstring
= N_("invalid ELF header");
1559 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1560 /* This is not a fatal error. On architectures where
1561 32-bit and 64-bit binaries can be run this might
1564 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1566 if (BYTE_ORDER
== BIG_ENDIAN
)
1567 errstring
= N_("ELF file data encoding not big-endian");
1569 errstring
= N_("ELF file data encoding not little-endian");
1571 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1573 = N_("ELF file version ident does not match current one");
1574 /* XXX We should be able so set system specific versions which are
1576 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1577 errstring
= N_("ELF file OS ABI invalid");
1578 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1579 errstring
= N_("ELF file ABI version invalid");
1581 /* Otherwise we don't know what went wrong. */
1582 errstring
= N_("internal error");
1587 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1589 errstring
= N_("ELF file version does not match current one");
1592 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1594 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1595 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1597 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1600 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1601 != sizeof (ElfW(Phdr
)))
1603 errstring
= N_("ELF file's phentsize not the expected size");
1607 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1608 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1609 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1612 phdr
= alloca (maplength
);
1613 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1614 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1618 errstring
= N_("cannot read file data");
1623 /* Check .note.ABI-tag if present. */
1624 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1625 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
== 32 && ph
->p_align
>= 4)
1627 if (ph
->p_offset
+ 32 <= (size_t) fbp
->len
)
1628 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1631 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1632 if (__libc_read (fd
, (void *) abi_note_buf
, 32) != 32)
1635 abi_note
= abi_note_buf
;
1638 if (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1641 osversion
= (abi_note
[5] & 0xff) * 65536
1642 + (abi_note
[6] & 0xff) * 256
1643 + (abi_note
[7] & 0xff);
1644 if (abi_note
[4] != __ABI_TAG_OS
1645 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1649 __set_errno (ENOENT
);
1660 /* Try to open NAME in one of the directories in *DIRSP.
1661 Return the fd, or -1. If successful, fill in *REALNAME
1662 with the malloc'd full directory name. If it turns out
1663 that none of the directories in *DIRSP exists, *DIRSP is
1664 replaced with (void *) -1, and the old value is free()d
1665 if MAY_FREE_DIRS is true. */
1668 open_path (const char *name
, size_t namelen
, int preloaded
,
1669 struct r_search_path_struct
*sps
, char **realname
,
1670 struct filebuf
*fbp
)
1672 struct r_search_path_elem
**dirs
= sps
->dirs
;
1675 const char *current_what
= NULL
;
1678 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1681 struct r_search_path_elem
*this_dir
= *dirs
;
1688 /* If we are debugging the search for libraries print the path
1689 now if it hasn't happened now. */
1690 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1691 && current_what
!= this_dir
->what
)
1693 current_what
= this_dir
->what
;
1694 print_search_path (dirs
, current_what
, this_dir
->where
);
1697 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1698 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1700 /* Skip this directory if we know it does not exist. */
1701 if (this_dir
->status
[cnt
] == nonexisting
)
1705 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1710 /* Print name we try if this is wanted. */
1711 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1712 _dl_debug_printf (" trying file=%s\n", buf
);
1714 fd
= open_verify (buf
, fbp
);
1715 if (this_dir
->status
[cnt
] == unknown
)
1718 this_dir
->status
[cnt
] = existing
;
1721 /* We failed to open machine dependent library. Let's
1722 test whether there is any directory at all. */
1725 buf
[buflen
- namelen
- 1] = '\0';
1727 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1728 || ! S_ISDIR (st
.st_mode
))
1729 /* The directory does not exist or it is no directory. */
1730 this_dir
->status
[cnt
] = nonexisting
;
1732 this_dir
->status
[cnt
] = existing
;
1736 /* Remember whether we found any existing directory. */
1737 here_any
|= this_dir
->status
[cnt
] == existing
;
1739 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1740 && INTUSE(__libc_enable_secure
))
1742 /* This is an extra security effort to make sure nobody can
1743 preload broken shared objects which are in the trusted
1744 directories and so exploit the bugs. */
1747 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1748 || (st
.st_mode
& S_ISUID
) == 0)
1750 /* The shared object cannot be tested for being SUID
1751 or this bit is not set. In this case we must not
1755 /* We simply ignore the file, signal this by setting
1756 the error value which would have been set by `open'. */
1764 *realname
= (char *) malloc (buflen
);
1765 if (*realname
!= NULL
)
1767 memcpy (*realname
, buf
, buflen
);
1772 /* No memory for the name, we certainly won't be able
1773 to load and link it. */
1778 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1779 /* The file exists and is readable, but something went wrong. */
1782 /* Remember whether we found anything. */
1785 while (*++dirs
!= NULL
);
1787 /* Remove the whole path if none of the directories exists. */
1788 if (__builtin_expect (! any
, 0))
1790 /* Paths which were allocated using the minimal malloc() in ld.so
1791 must not be freed using the general free() in libc. */
1795 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1797 if (sps
!= &rtld_search_dirs
)
1799 sps
->dirs
= (void *) -1;
1805 /* Map in the shared object file NAME. */
1809 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1810 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1819 assert (nsid
< DL_NNS
);
1821 /* Look for this name among those already loaded. */
1822 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1824 /* If the requested name matches the soname of a loaded object,
1825 use that object. Elide this check for names that have not
1827 if (__builtin_expect (l
->l_faked
, 0) != 0
1828 || __builtin_expect (l
->l_removed
, 0) != 0)
1830 if (!_dl_name_match_p (name
, l
))
1834 if (__builtin_expect (l
->l_soname_added
, 1)
1835 || l
->l_info
[DT_SONAME
] == NULL
)
1838 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1839 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1840 if (strcmp (name
, soname
) != 0)
1843 /* We have a match on a new name -- cache it. */
1844 add_name_to_object (l
, soname
);
1845 l
->l_soname_added
= 1;
1848 /* We have a match. */
1852 /* Display information if we are debugging. */
1853 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
1855 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
1857 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
1859 if (strchr (name
, '/') == NULL
)
1861 /* Search for NAME in several places. */
1863 size_t namelen
= strlen (name
) + 1;
1865 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1866 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
1870 /* When the object has the RUNPATH information we don't use any
1872 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
1874 /* First try the DT_RPATH of the dependent object that caused NAME
1875 to be loaded. Then that object's dependent, and on up. */
1876 for (l
= loader
; fd
== -1 && l
; l
= l
->l_loader
)
1877 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
1878 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
1881 /* If dynamically linked, try the DT_RPATH of the executable
1882 itself. NB: we do this for lookups in any namespace. */
1885 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1886 if (l
&& l
->l_type
!= lt_loaded
&& l
!= loader
1887 && cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
1888 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
1893 /* Try the LD_LIBRARY_PATH environment variable. */
1894 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
1895 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
1898 /* Look at the RUNPATH information for this binary. */
1899 if (fd
== -1 && loader
!= NULL
1900 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
1901 DT_RUNPATH
, "RUNPATH"))
1902 fd
= open_path (name
, namelen
, preloaded
,
1903 &loader
->l_runpath_dirs
, &realname
, &fb
);
1906 && (__builtin_expect (! preloaded
, 1)
1907 || ! INTUSE(__libc_enable_secure
)))
1909 /* Check the list of libraries in the file /etc/ld.so.cache,
1910 for compatibility with Linux's ldconfig program. */
1911 const char *cached
= _dl_load_cache_lookup (name
);
1916 // XXX Correct to unconditionally default to namespace 0?
1917 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1922 /* If the loader has the DF_1_NODEFLIB flag set we must not
1923 use a cache entry from any of these directories. */
1926 /* 'l' is always != NULL for dynamically linked objects. */
1929 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
1931 const char *dirp
= system_dirs
;
1932 unsigned int cnt
= 0;
1936 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
1938 /* The prefix matches. Don't use the entry. */
1943 dirp
+= system_dirs_len
[cnt
] + 1;
1946 while (cnt
< nsystem_dirs_len
);
1951 fd
= open_verify (cached
, &fb
);
1952 if (__builtin_expect (fd
!= -1, 1))
1954 realname
= local_strdup (cached
);
1955 if (realname
== NULL
)
1965 /* Finally, try the default path. */
1967 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
1968 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
1969 && rtld_search_dirs
.dirs
!= (void *) -1)
1970 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
1973 /* Add another newline when we are tracing the library loading. */
1974 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1975 _dl_debug_printf ("\n");
1979 /* The path may contain dynamic string tokens. */
1981 ? expand_dynamic_string_token (loader
, name
)
1982 : local_strdup (name
));
1983 if (realname
== NULL
)
1987 fd
= open_verify (realname
, &fb
);
1988 if (__builtin_expect (fd
, 0) == -1)
1993 /* In case the LOADER information has only been provided to get to
1994 the appropriate RUNPATH/RPATH information we do not need it
1996 if (mode
& __RTLD_CALLMAP
)
1999 if (__builtin_expect (fd
, 0) == -1)
2002 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2004 /* We haven't found an appropriate library. But since we
2005 are only interested in the list of libraries this isn't
2006 so severe. Fake an entry with all the information we
2008 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2010 /* Enter the new object in the list of loaded objects. */
2011 if ((name_copy
= local_strdup (name
)) == NULL
2012 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2013 mode
, nsid
)) == NULL
)
2014 _dl_signal_error (ENOMEM
, name
, NULL
,
2015 N_("cannot create shared object descriptor"));
2016 /* Signal that this is a faked entry. */
2018 /* Since the descriptor is initialized with zero we do not
2020 l->l_reserved = 0; */
2021 l
->l_buckets
= &dummy_bucket
;
2028 _dl_signal_error (errno
, name
, NULL
,
2029 N_("cannot open shared object file"));
2032 void *stack_end
= __libc_stack_end
;
2033 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2040 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2048 unsigned int idx
= 0;
2049 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2050 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2051 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2053 if (sps
->dirs
!= (void *) -1)
2055 struct r_search_path_elem
**dirs
= sps
->dirs
;
2058 const struct r_search_path_elem
*const r
= *dirs
++;
2062 si
->dls_size
+= r
->dirnamelen
;
2066 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2067 sp
->dls_name
= allocptr
;
2068 allocptr
= __mempcpy (allocptr
,
2069 r
->dirname
, r
->dirnamelen
- 1);
2071 sp
->dls_flags
= flags
;
2074 while (*dirs
!= NULL
);
2078 /* When the object has the RUNPATH information we don't use any RPATHs. */
2079 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2081 /* First try the DT_RPATH of the dependent object that caused NAME
2082 to be loaded. Then that object's dependent, and on up. */
2084 struct link_map
*l
= loader
;
2087 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2088 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2093 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2094 if (loader
->l_ns
== LM_ID_BASE
)
2096 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2097 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2098 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2099 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2103 /* Try the LD_LIBRARY_PATH environment variable. */
2104 add_path (&env_path_list
, XXX_ENV
);
2106 /* Look at the RUNPATH information for this binary. */
2107 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2108 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2111 Here is where ld.so.cache gets checked, but we don't have
2112 a way to indicate that in the results for Dl_serinfo. */
2114 /* Finally, try the default path. */
2115 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2116 add_path (&rtld_search_dirs
, XXX_default
);
2119 /* Count the struct size before the string area, which we didn't
2120 know before we completed dls_cnt. */
2121 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;