1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <bits/wordsize.h>
31 #include <sys/param.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
36 #include <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
;
829 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
830 bool make_consistent
= false;
832 /* Get file information. */
833 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
835 errstring
= N_("cannot stat shared object");
841 r
->r_state
= RT_CONSISTENT
;
845 lose (errval
, fd
, name
, realname
, l
, errstring
);
848 /* Look again to see if the real name matched another already loaded. */
849 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
850 if (l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
852 /* The object is already loaded.
853 Just bump its reference count and return it. */
856 /* If the name is not in the list of names for this object add
859 add_name_to_object (l
, name
);
865 /* When loading into a namespace other than the base one we must
866 avoid loading ld.so since there can only be one copy. Ever. */
867 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
868 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
869 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
870 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
872 /* This is indeed ld.so. Create a new link_map which refers to
873 the real one for almost everything. */
874 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
878 /* Refer to the real descriptor. */
879 l
->l_real
= &GL(dl_rtld_map
);
881 /* No need to bump the refcount of the real object, ld.so will
882 never be unloaded. */
889 if (mode
& RTLD_NOLOAD
)
890 /* We are not supposed to load the object unless it is already
891 loaded. So return now. */
894 /* Print debugging message. */
895 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
896 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
898 /* This is the ELF header. We read it in `open_verify'. */
899 header
= (void *) fbp
->buf
;
903 if (_dl_zerofd
== -1)
905 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
906 if (_dl_zerofd
== -1)
909 _dl_signal_error (errno
, NULL
, NULL
,
910 N_("cannot open zero fill device"));
915 /* Signal that we are going to add new objects. */
916 if (r
->r_state
== RT_CONSISTENT
)
919 /* Auditing checkpoint: we are going to add new objects. */
920 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
922 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
923 /* Do not call the functions for any auditing object. */
924 if (head
->l_auditing
== 0)
926 struct audit_ifaces
*afct
= GLRO(dl_audit
);
927 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
929 if (afct
->activity
!= NULL
)
930 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
938 /* Notify the debugger we have added some objects. We need to
939 call _dl_debug_initialize in a static program in case dynamic
940 linking has not been used before. */
943 make_consistent
= true;
946 assert (r
->r_state
== RT_ADD
);
948 /* Enter the new object in the list of loaded objects. */
949 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
950 if (__builtin_expect (l
== NULL
, 0))
955 errstring
= N_("cannot create shared object descriptor");
956 goto call_lose_errno
;
959 /* Extract the remaining details we need from the ELF header
960 and then read in the program header table. */
961 l
->l_entry
= header
->e_entry
;
962 type
= header
->e_type
;
963 l
->l_phnum
= header
->e_phnum
;
965 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
966 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
967 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
970 phdr
= alloca (maplength
);
971 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
972 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
974 errstring
= N_("cannot read file data");
975 goto call_lose_errno
;
979 /* Presumed absent PT_GNU_STACK. */
980 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
983 /* Scan the program header table, collecting its load commands. */
986 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
989 } loadcmds
[l
->l_phnum
], *c
;
990 size_t nloadcmds
= 0;
991 bool has_holes
= false;
993 /* The struct is initialized to zero so this is not necessary:
997 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1000 /* These entries tell us where to find things once the file's
1001 segments are mapped in. We record the addresses it says
1002 verbatim, and later correct for the run-time load address. */
1004 l
->l_ld
= (void *) ph
->p_vaddr
;
1005 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1009 l
->l_phdr
= (void *) ph
->p_vaddr
;
1013 /* A load command tells us to map in part of the file.
1014 We record the load commands and process them all later. */
1015 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1018 errstring
= N_("ELF load command alignment not page-aligned");
1021 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1022 & (ph
->p_align
- 1)) != 0, 0))
1025 = N_("ELF load command address/offset not properly aligned");
1029 c
= &loadcmds
[nloadcmds
++];
1030 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1031 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1032 & ~(GLRO(dl_pagesize
) - 1));
1033 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1034 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1035 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1037 /* Determine whether there is a gap between the last segment
1039 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1042 /* Optimize a common case. */
1043 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1044 c
->prot
= (PF_TO_PROT
1045 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1048 if (ph
->p_flags
& PF_R
)
1049 c
->prot
|= PROT_READ
;
1050 if (ph
->p_flags
& PF_W
)
1051 c
->prot
|= PROT_WRITE
;
1052 if (ph
->p_flags
& PF_X
)
1053 c
->prot
|= PROT_EXEC
;
1059 if (ph
->p_memsz
== 0)
1060 /* Nothing to do for an empty segment. */
1063 l
->l_tls_blocksize
= ph
->p_memsz
;
1064 l
->l_tls_align
= ph
->p_align
;
1065 if (ph
->p_align
== 0)
1066 l
->l_tls_firstbyte_offset
= 0;
1068 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1069 l
->l_tls_initimage_size
= ph
->p_filesz
;
1070 /* Since we don't know the load address yet only store the
1071 offset. We will adjust it later. */
1072 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1074 /* If not loading the initial set of shared libraries,
1075 check whether we should permit loading a TLS segment. */
1076 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1077 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1078 not set up TLS data structures, so don't use them now. */
1079 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1081 /* Assign the next available module ID. */
1082 l
->l_tls_modid
= _dl_next_tls_modid ();
1087 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1088 /* We are loading the executable itself when the dynamic linker
1089 was executed directly. The setup will happen later. */
1092 /* In a static binary there is no way to tell if we dynamically
1093 loaded libpthread. */
1094 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1097 /* We have not yet loaded libpthread.
1098 We can do the TLS setup right now! */
1102 /* The first call allocates TLS bookkeeping data structures.
1103 Then we allocate the TCB for the initial thread. */
1104 if (__builtin_expect (_dl_tls_setup (), 0)
1105 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1110 cannot allocate TLS data structures for initial thread");
1114 /* Now we install the TCB in the thread register. */
1115 errstring
= TLS_INIT_TP (tcb
, 0);
1116 if (__builtin_expect (errstring
== NULL
, 1))
1118 /* Now we are all good. */
1119 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1123 /* The kernel is too old or somesuch. */
1125 _dl_deallocate_tls (tcb
, 1);
1130 /* Uh-oh, the binary expects TLS support but we cannot
1133 errstring
= N_("cannot handle TLS data");
1138 stack_flags
= ph
->p_flags
;
1142 l
->l_relro_addr
= ph
->p_vaddr
;
1143 l
->l_relro_size
= ph
->p_memsz
;
1147 if (__builtin_expect (nloadcmds
== 0, 0))
1149 /* This only happens for a bogus object that will be caught with
1150 another error below. But we don't want to go through the
1151 calculations below using NLOADCMDS - 1. */
1152 errstring
= N_("object file has no loadable segments");
1156 /* Now process the load commands and map segments into memory. */
1159 /* Length of the sections to be loaded. */
1160 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1162 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1164 /* This is a position-independent shared object. We can let the
1165 kernel map it anywhere it likes, but we must have space for all
1166 the segments in their specified positions relative to the first.
1167 So we map the first segment without MAP_FIXED, but with its
1168 extent increased to cover all the segments. Then we remove
1169 access from excess portion, and there is known sufficient space
1170 there to remap from the later segments.
1172 As a refinement, sometimes we have an address that we would
1173 prefer to map such objects at; but this is only a preference,
1174 the OS can do whatever it likes. */
1176 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1177 c
->mapstart
& GLRO(dl_use_load_bias
))
1178 - MAP_BASE_ADDR (l
));
1180 /* Remember which part of the address space this object uses. */
1181 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1183 MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1185 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1188 errstring
= N_("failed to map segment from shared object");
1189 goto call_lose_errno
;
1192 l
->l_map_end
= l
->l_map_start
+ maplength
;
1193 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1196 /* Change protection on the excess portion to disallow all access;
1197 the portions we do not remap later will be inaccessible as if
1198 unallocated. Then jump into the normal segment-mapping loop to
1199 handle the portion of the segment past the end of the file
1201 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1202 loadcmds
[nloadcmds
- 1].allocend
- c
->mapend
,
1208 /* This object is loaded at a fixed address. This must never
1209 happen for objects loaded with dlopen(). */
1210 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1212 errstring
= N_("cannot dynamically load executable");
1216 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1218 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1221 /* Remember which part of the address space this object uses. */
1222 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1223 l
->l_map_end
= l
->l_map_start
+ maplength
;
1225 while (c
< &loadcmds
[nloadcmds
])
1227 if (c
->mapend
> c
->mapstart
1228 /* Map the segment contents from the file. */
1229 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1230 c
->mapend
- c
->mapstart
, c
->prot
,
1231 MAP_FIXED
|MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1237 if (c
->prot
& PROT_EXEC
)
1238 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1241 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1242 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1243 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1244 /* Found the program header in this segment. */
1245 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1247 if (c
->allocend
> c
->dataend
)
1249 /* Extra zero pages should appear at the end of this segment,
1250 after the data mapped from the file. */
1251 ElfW(Addr
) zero
, zeroend
, zeropage
;
1253 zero
= l
->l_addr
+ c
->dataend
;
1254 zeroend
= l
->l_addr
+ c
->allocend
;
1255 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1256 & ~(GLRO(dl_pagesize
) - 1));
1258 if (zeroend
< zeropage
)
1259 /* All the extra data is in the last page of the segment.
1260 We can just zero it. */
1263 if (zeropage
> zero
)
1265 /* Zero the final part of the last page of the segment. */
1266 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1269 if (__mprotect ((caddr_t
) (zero
1270 & ~(GLRO(dl_pagesize
) - 1)),
1271 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1273 errstring
= N_("cannot change memory protections");
1274 goto call_lose_errno
;
1277 memset ((void *) zero
, '\0', zeropage
- zero
);
1278 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1279 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1280 GLRO(dl_pagesize
), c
->prot
);
1283 if (zeroend
> zeropage
)
1285 /* Map the remaining zero pages in from the zero fill FD. */
1287 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1288 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1290 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1292 errstring
= N_("cannot map zero-fill pages");
1293 goto call_lose_errno
;
1304 if (__builtin_expect (type
== ET_DYN
, 0))
1306 errstring
= N_("object file has no dynamic section");
1311 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1313 elf_get_dynamic_info (l
, NULL
);
1315 /* Make sure we are not dlopen'ing an object that has the
1316 DF_1_NOOPEN flag set. */
1317 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1318 && (mode
& __RTLD_DLOPEN
))
1320 /* We are not supposed to load this object. Free all resources. */
1321 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1323 if (!l
->l_libname
->dont_free
)
1324 free (l
->l_libname
);
1326 if (l
->l_phdr_allocated
)
1327 free ((void *) l
->l_phdr
);
1329 errstring
= N_("shared object cannot be dlopen()ed");
1333 if (l
->l_phdr
== NULL
)
1335 /* The program header is not contained in any of the segments.
1336 We have to allocate memory ourself and copy it over from out
1338 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1339 * sizeof (ElfW(Phdr
)));
1342 errstring
= N_("cannot allocate memory for program header");
1343 goto call_lose_errno
;
1346 l
->l_phdr
= memcpy (newp
, phdr
,
1347 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1348 l
->l_phdr_allocated
= 1;
1351 /* Adjust the PT_PHDR value by the runtime load address. */
1352 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1354 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1356 /* The stack is presently not executable, but this module
1357 requires that it be executable. We must change the
1358 protection of the variable which contains the flags used in
1359 the mprotect calls. */
1361 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1363 uintptr_t p
= ((uintptr_t) &__stack_prot
) & ~(GLRO(dl_pagesize
) - 1);
1364 size_t s
= (uintptr_t) &__stack_prot
- p
+ sizeof (int);
1366 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1367 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0),
1370 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1371 __mprotect ((void *) p
, s
, PROT_READ
);
1375 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1377 #ifdef check_consistency
1378 check_consistency ();
1381 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1385 cannot enable executable stack as shared object requires");
1391 /* Adjust the address of the TLS initialization image. */
1392 if (l
->l_tls_initimage
!= NULL
)
1393 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1396 /* We are done mapping in the file. We no longer need the descriptor. */
1397 if (__builtin_expect (__close (fd
) != 0, 0))
1399 errstring
= N_("cannot close file descriptor");
1400 goto call_lose_errno
;
1402 /* Signal that we closed the file. */
1405 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1406 l
->l_type
= lt_executable
;
1408 l
->l_entry
+= l
->l_addr
;
1410 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1411 _dl_debug_printf ("\
1412 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1413 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1414 (int) sizeof (void *) * 2,
1415 (unsigned long int) l
->l_ld
,
1416 (int) sizeof (void *) * 2,
1417 (unsigned long int) l
->l_addr
,
1418 (int) sizeof (void *) * 2, maplength
,
1419 (int) sizeof (void *) * 2,
1420 (unsigned long int) l
->l_entry
,
1421 (int) sizeof (void *) * 2,
1422 (unsigned long int) l
->l_phdr
,
1423 (int) sizeof (void *) * 2, l
->l_phnum
);
1425 /* Set up the symbol hash table. */
1428 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1429 have to do this for the main map. */
1430 if ((mode
& RTLD_DEEPBIND
) == 0
1431 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1432 && &l
->l_searchlist
!= l
->l_scope
[0])
1434 /* Create an appropriate searchlist. It contains only this map.
1435 This is the definition of DT_SYMBOLIC in SysVr4. */
1436 l
->l_symbolic_searchlist
.r_list
=
1437 (struct link_map
**) malloc (sizeof (struct link_map
*));
1439 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1441 errstring
= N_("cannot create searchlist");
1442 goto call_lose_errno
;
1445 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1446 l
->l_symbolic_searchlist
.r_nlist
= 1;
1448 /* Now move the existing entries one back. */
1449 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1450 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1452 /* Now add the new entry. */
1453 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1456 /* Remember whether this object must be initialized first. */
1457 if (l
->l_flags_1
& DF_1_INITFIRST
)
1458 GL(dl_initfirst
) = l
;
1460 /* Finally the file information. */
1461 l
->l_dev
= st
.st_dev
;
1462 l
->l_ino
= st
.st_ino
;
1464 /* When we profile the SONAME might be needed for something else but
1465 loading. Add it right away. */
1466 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1467 && l
->l_info
[DT_SONAME
] != NULL
)
1468 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1469 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1472 /* Auditing checkpoint: we have a new object. */
1473 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1474 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1476 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1477 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1479 if (afct
->objopen
!= NULL
)
1481 l
->l_audit
[cnt
].bindflags
1482 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1484 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1495 /* Print search path. */
1497 print_search_path (struct r_search_path_elem
**list
,
1498 const char *what
, const char *name
)
1500 char buf
[max_dirnamelen
+ max_capstrlen
];
1503 _dl_debug_printf (" search path=");
1505 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1507 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1510 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1511 if ((*list
)->status
[cnt
] != nonexisting
)
1513 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1514 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1519 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1527 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1528 name
[0] ? name
: rtld_progname
);
1530 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1533 /* Open a file and verify it is an ELF file for this architecture. We
1534 ignore only ELF files for other architectures. Non-ELF files and
1535 ELF files with different header information cause fatal errors since
1536 this could mean there is something wrong in the installation and the
1537 user might want to know about this. */
1539 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1542 /* This is the expected ELF header. */
1543 #define ELF32_CLASS ELFCLASS32
1544 #define ELF64_CLASS ELFCLASS64
1545 #ifndef VALID_ELF_HEADER
1546 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1547 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1548 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1550 static const unsigned char expected
[EI_PAD
] =
1552 [EI_MAG0
] = ELFMAG0
,
1553 [EI_MAG1
] = ELFMAG1
,
1554 [EI_MAG2
] = ELFMAG2
,
1555 [EI_MAG3
] = ELFMAG3
,
1556 [EI_CLASS
] = ELFW(CLASS
),
1557 [EI_DATA
] = byteorder
,
1558 [EI_VERSION
] = EV_CURRENT
,
1559 [EI_OSABI
] = ELFOSABI_SYSV
,
1564 ElfW(Word
) vendorlen
;
1568 } expected_note
= { 4, 16, 1, "GNU" };
1569 /* Initialize it to make the compiler happy. */
1570 const char *errstring
= NULL
;
1574 /* Give the auditing libraries a chance. */
1575 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1576 && loader
->l_auditing
== 0)
1578 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1579 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1581 if (afct
->objsearch
!= NULL
)
1583 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1586 /* Ignore the path. */
1595 /* Open the file. We always open files read-only. */
1596 int fd
= __open (name
, O_RDONLY
);
1600 ElfW(Phdr
) *phdr
, *ph
;
1601 ElfW(Word
) *abi_note
, abi_note_buf
[8];
1602 unsigned int osversion
;
1605 /* We successfully openened the file. Now verify it is a file
1608 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1610 /* This is where the ELF header is loaded. */
1611 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1612 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1614 /* Now run the tests. */
1615 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1618 errstring
= (errval
== 0
1619 ? N_("file too short") : N_("cannot read file data"));
1621 lose (errval
, fd
, name
, NULL
, NULL
, errstring
);
1624 /* See whether the ELF header is what we expect. */
1625 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1628 /* Something is wrong. */
1629 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1630 #if BYTE_ORDER == LITTLE_ENDIAN
1631 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1632 (ELFMAG1
<< (EI_MAG1
* 8)) |
1633 (ELFMAG2
<< (EI_MAG2
* 8)) |
1634 (ELFMAG3
<< (EI_MAG3
* 8)))
1636 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1637 (ELFMAG1
<< (EI_MAG2
* 8)) |
1638 (ELFMAG2
<< (EI_MAG1
* 8)) |
1639 (ELFMAG3
<< (EI_MAG0
* 8)))
1642 errstring
= N_("invalid ELF header");
1643 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1644 /* This is not a fatal error. On architectures where
1645 32-bit and 64-bit binaries can be run this might
1648 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1650 if (BYTE_ORDER
== BIG_ENDIAN
)
1651 errstring
= N_("ELF file data encoding not big-endian");
1653 errstring
= N_("ELF file data encoding not little-endian");
1655 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1657 = N_("ELF file version ident does not match current one");
1658 /* XXX We should be able so set system specific versions which are
1660 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1661 errstring
= N_("ELF file OS ABI invalid");
1662 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1663 errstring
= N_("ELF file ABI version invalid");
1665 /* Otherwise we don't know what went wrong. */
1666 errstring
= N_("internal error");
1671 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1673 errstring
= N_("ELF file version does not match current one");
1676 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1678 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1679 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1681 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1684 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1685 != sizeof (ElfW(Phdr
)))
1687 errstring
= N_("ELF file's phentsize not the expected size");
1691 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1692 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1693 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1696 phdr
= alloca (maplength
);
1697 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1698 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1702 errstring
= N_("cannot read file data");
1707 /* Check .note.ABI-tag if present. */
1708 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1709 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
== 32 && ph
->p_align
>= 4)
1711 if (ph
->p_offset
+ 32 <= (size_t) fbp
->len
)
1712 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1715 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1716 if (__libc_read (fd
, (void *) abi_note_buf
, 32) != 32)
1719 abi_note
= abi_note_buf
;
1722 if (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1725 osversion
= (abi_note
[5] & 0xff) * 65536
1726 + (abi_note
[6] & 0xff) * 256
1727 + (abi_note
[7] & 0xff);
1728 if (abi_note
[4] != __ABI_TAG_OS
1729 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1733 __set_errno (ENOENT
);
1744 /* Try to open NAME in one of the directories in *DIRSP.
1745 Return the fd, or -1. If successful, fill in *REALNAME
1746 with the malloc'd full directory name. If it turns out
1747 that none of the directories in *DIRSP exists, *DIRSP is
1748 replaced with (void *) -1, and the old value is free()d
1749 if MAY_FREE_DIRS is true. */
1752 open_path (const char *name
, size_t namelen
, int preloaded
,
1753 struct r_search_path_struct
*sps
, char **realname
,
1754 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
)
1756 struct r_search_path_elem
**dirs
= sps
->dirs
;
1759 const char *current_what
= NULL
;
1762 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1765 struct r_search_path_elem
*this_dir
= *dirs
;
1772 /* If we are debugging the search for libraries print the path
1773 now if it hasn't happened now. */
1774 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1775 && current_what
!= this_dir
->what
)
1777 current_what
= this_dir
->what
;
1778 print_search_path (dirs
, current_what
, this_dir
->where
);
1781 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1782 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1784 /* Skip this directory if we know it does not exist. */
1785 if (this_dir
->status
[cnt
] == nonexisting
)
1789 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1794 /* Print name we try if this is wanted. */
1795 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1796 _dl_debug_printf (" trying file=%s\n", buf
);
1798 fd
= open_verify (buf
, fbp
, loader
, whatcode
);
1799 if (this_dir
->status
[cnt
] == unknown
)
1802 this_dir
->status
[cnt
] = existing
;
1803 /* Do not update the directory information when loading
1804 auditing code. We must try to disturb the program as
1805 little as possible. */
1806 else if (loader
== NULL
1807 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_audit
== 0)
1809 /* We failed to open machine dependent library. Let's
1810 test whether there is any directory at all. */
1813 buf
[buflen
- namelen
- 1] = '\0';
1815 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1816 || ! S_ISDIR (st
.st_mode
))
1817 /* The directory does not exist or it is no directory. */
1818 this_dir
->status
[cnt
] = nonexisting
;
1820 this_dir
->status
[cnt
] = existing
;
1824 /* Remember whether we found any existing directory. */
1825 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1827 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1828 && INTUSE(__libc_enable_secure
))
1830 /* This is an extra security effort to make sure nobody can
1831 preload broken shared objects which are in the trusted
1832 directories and so exploit the bugs. */
1835 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1836 || (st
.st_mode
& S_ISUID
) == 0)
1838 /* The shared object cannot be tested for being SUID
1839 or this bit is not set. In this case we must not
1843 /* We simply ignore the file, signal this by setting
1844 the error value which would have been set by `open'. */
1852 *realname
= (char *) malloc (buflen
);
1853 if (*realname
!= NULL
)
1855 memcpy (*realname
, buf
, buflen
);
1860 /* No memory for the name, we certainly won't be able
1861 to load and link it. */
1866 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1867 /* The file exists and is readable, but something went wrong. */
1870 /* Remember whether we found anything. */
1873 while (*++dirs
!= NULL
);
1875 /* Remove the whole path if none of the directories exists. */
1876 if (__builtin_expect (! any
, 0))
1878 /* Paths which were allocated using the minimal malloc() in ld.so
1879 must not be freed using the general free() in libc. */
1883 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1885 if (sps
!= &rtld_search_dirs
)
1887 sps
->dirs
= (void *) -1;
1893 /* Map in the shared object file NAME. */
1897 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1898 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1907 assert (nsid
< DL_NNS
);
1909 /* Look for this name among those already loaded. */
1910 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1912 /* If the requested name matches the soname of a loaded object,
1913 use that object. Elide this check for names that have not
1915 if (__builtin_expect (l
->l_faked
, 0) != 0)
1917 if (!_dl_name_match_p (name
, l
))
1921 if (__builtin_expect (l
->l_soname_added
, 1)
1922 || l
->l_info
[DT_SONAME
] == NULL
)
1925 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1926 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1927 if (strcmp (name
, soname
) != 0)
1930 /* We have a match on a new name -- cache it. */
1931 add_name_to_object (l
, soname
);
1932 l
->l_soname_added
= 1;
1935 /* We have a match. */
1939 /* Display information if we are debugging. */
1940 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
1942 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
1944 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
1947 /* Give the auditing libraries a chance to change the name before we
1949 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1950 && (loader
== NULL
|| loader
->l_auditing
== 0))
1952 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1953 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1955 if (afct
->objsearch
!= NULL
)
1957 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1961 /* Do not try anything further. */
1972 if (strchr (name
, '/') == NULL
)
1974 /* Search for NAME in several places. */
1976 size_t namelen
= strlen (name
) + 1;
1978 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1979 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
1983 /* When the object has the RUNPATH information we don't use any
1985 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
1987 /* First try the DT_RPATH of the dependent object that caused NAME
1988 to be loaded. Then that object's dependent, and on up. */
1989 for (l
= loader
; fd
== -1 && l
; l
= l
->l_loader
)
1990 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
1991 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
1992 &realname
, &fb
, loader
, LA_SER_RUNPATH
);
1994 /* If dynamically linked, try the DT_RPATH of the executable
1995 itself. NB: we do this for lookups in any namespace. */
1998 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1999 if (l
&& l
->l_type
!= lt_loaded
&& l
!= loader
2000 && cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2001 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2002 &realname
, &fb
, loader
?: l
, LA_SER_RUNPATH
);
2006 /* Try the LD_LIBRARY_PATH environment variable. */
2007 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2008 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2010 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2013 /* Look at the RUNPATH information for this binary. */
2014 if (fd
== -1 && loader
!= NULL
2015 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2016 DT_RUNPATH
, "RUNPATH"))
2017 fd
= open_path (name
, namelen
, preloaded
,
2018 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2022 && (__builtin_expect (! preloaded
, 1)
2023 || ! INTUSE(__libc_enable_secure
)))
2025 /* Check the list of libraries in the file /etc/ld.so.cache,
2026 for compatibility with Linux's ldconfig program. */
2027 const char *cached
= _dl_load_cache_lookup (name
);
2032 // XXX Correct to unconditionally default to namespace 0?
2033 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2038 /* If the loader has the DF_1_NODEFLIB flag set we must not
2039 use a cache entry from any of these directories. */
2042 /* 'l' is always != NULL for dynamically linked objects. */
2045 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2047 const char *dirp
= system_dirs
;
2048 unsigned int cnt
= 0;
2052 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2054 /* The prefix matches. Don't use the entry. */
2059 dirp
+= system_dirs_len
[cnt
] + 1;
2062 while (cnt
< nsystem_dirs_len
);
2067 fd
= open_verify (cached
,
2068 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2070 if (__builtin_expect (fd
!= -1, 1))
2072 realname
= local_strdup (cached
);
2073 if (realname
== NULL
)
2083 /* Finally, try the default path. */
2085 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2086 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2087 && rtld_search_dirs
.dirs
!= (void *) -1)
2088 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2089 &realname
, &fb
, l
, LA_SER_DEFAULT
);
2091 /* Add another newline when we are tracing the library loading. */
2092 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2093 _dl_debug_printf ("\n");
2097 /* The path may contain dynamic string tokens. */
2099 ? expand_dynamic_string_token (loader
, name
)
2100 : local_strdup (name
));
2101 if (realname
== NULL
)
2105 fd
= open_verify (realname
, &fb
,
2106 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0);
2107 if (__builtin_expect (fd
, 0) == -1)
2115 /* In case the LOADER information has only been provided to get to
2116 the appropriate RUNPATH/RPATH information we do not need it
2118 if (mode
& __RTLD_CALLMAP
)
2121 if (__builtin_expect (fd
, 0) == -1)
2124 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2126 /* We haven't found an appropriate library. But since we
2127 are only interested in the list of libraries this isn't
2128 so severe. Fake an entry with all the information we
2130 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2132 /* Enter the new object in the list of loaded objects. */
2133 if ((name_copy
= local_strdup (name
)) == NULL
2134 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2135 mode
, nsid
)) == NULL
)
2136 _dl_signal_error (ENOMEM
, name
, NULL
,
2137 N_("cannot create shared object descriptor"));
2138 /* Signal that this is a faked entry. */
2140 /* Since the descriptor is initialized with zero we do not
2142 l->l_reserved = 0; */
2143 l
->l_buckets
= &dummy_bucket
;
2150 _dl_signal_error (errno
, name
, NULL
,
2151 N_("cannot open shared object file"));
2154 void *stack_end
= __libc_stack_end
;
2155 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2162 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2170 unsigned int idx
= 0;
2171 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2172 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2173 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2175 if (sps
->dirs
!= (void *) -1)
2177 struct r_search_path_elem
**dirs
= sps
->dirs
;
2180 const struct r_search_path_elem
*const r
= *dirs
++;
2184 si
->dls_size
+= r
->dirnamelen
;
2188 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2189 sp
->dls_name
= allocptr
;
2190 allocptr
= __mempcpy (allocptr
,
2191 r
->dirname
, r
->dirnamelen
- 1);
2193 sp
->dls_flags
= flags
;
2196 while (*dirs
!= NULL
);
2200 /* When the object has the RUNPATH information we don't use any RPATHs. */
2201 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2203 /* First try the DT_RPATH of the dependent object that caused NAME
2204 to be loaded. Then that object's dependent, and on up. */
2206 struct link_map
*l
= loader
;
2209 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2210 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2215 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2216 if (loader
->l_ns
== LM_ID_BASE
)
2218 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2219 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2220 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2221 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2225 /* Try the LD_LIBRARY_PATH environment variable. */
2226 add_path (&env_path_list
, XXX_ENV
);
2228 /* Look at the RUNPATH information for this binary. */
2229 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2230 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2233 Here is where ld.so.cache gets checked, but we don't have
2234 a way to indicate that in the results for Dl_serinfo. */
2236 /* Finally, try the default path. */
2237 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2238 add_path (&rtld_search_dirs
, XXX_default
);
2241 /* Count the struct size before the string area, which we didn't
2242 know before we completed dls_cnt. */
2243 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;