1 /* Map in a shared object's segments from the file.
2 Copyright (C) 1995-2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <bits/wordsize.h>
31 #include <sys/param.h>
33 #include <sys/types.h>
34 #include "dynamic-link.h"
36 #include <stackinfo.h>
42 /* On some systems, no flag bits are given to specify file mapping. */
47 /* The right way to map in the shared library files is MAP_COPY, which
48 makes a virtual copy of the data at the time of the mmap call; this
49 guarantees the mapped pages will be consistent even if the file is
50 overwritten. Some losing VM systems like Linux's lack MAP_COPY. All we
51 get is MAP_PRIVATE, which copies each page when it is modified; this
52 means if the file is overwritten, we may at some point get some pages
53 from the new version after starting with pages from the old version. */
55 # define MAP_COPY MAP_PRIVATE
58 /* We want to prevent people from modifying DSOs which are currently in
59 use. This is what MAP_DENYWRITE is for. */
61 # define MAP_DENYWRITE 0
64 /* Some systems link their relocatable objects for another base address
65 than 0. We want to know the base address for these such that we can
66 subtract this address from the segment addresses during mapping.
67 This results in a more efficient address space usage. Defaults to
68 zero for almost all systems. */
70 # define MAP_BASE_ADDR(l) 0
75 #if BYTE_ORDER == BIG_ENDIAN
76 # define byteorder ELFDATA2MSB
77 #elif BYTE_ORDER == LITTLE_ENDIAN
78 # define byteorder ELFDATA2LSB
80 # error "Unknown BYTE_ORDER " BYTE_ORDER
81 # define byteorder ELFDATANONE
84 #define STRING(x) __STRING (x)
87 /* The fd is not examined when using MAP_ANON. */
91 # define ANONFD _dl_zerofd
94 /* Handle situations where we have a preferred location in memory for
95 the shared objects. */
96 #ifdef ELF_PREFERRED_ADDRESS_DATA
97 ELF_PREFERRED_ADDRESS_DATA
;
99 #ifndef ELF_PREFERRED_ADDRESS
100 # define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
102 #ifndef ELF_FIXED_ADDRESS
103 # define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)
107 int __stack_prot attribute_hidden attribute_relro
108 #if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
110 #elif _STACK_GROWS_UP && defined PROT_GROWSUP
117 /* Type for the buffer we put the ELF header and hopefully the program
118 header. This buffer does not really have to be too large. In most
119 cases the program header follows the ELF header directly. If this
120 is not the case all bets are off and we can make the header
121 arbitrarily large and still won't get it read. This means the only
122 question is how large are the ELF and program header combined. The
123 ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
124 bytes long. Each program header entry is again 32 and 56 bytes
125 long respectively. I.e., even with a file which has 7 program
126 header entries we only have to read 512B. Add to this a bit of
127 margin for program notes and reading 512B and 640B for 32-bit and
128 64-bit files respecitvely is enough. If this heuristic should
129 really fail for some file the code in `_dl_map_object_from_fd'
130 knows how to recover. */
135 # define FILEBUF_SIZE 512
137 # define FILEBUF_SIZE 640
139 char buf
[FILEBUF_SIZE
] __attribute__ ((aligned (__alignof (ElfW(Ehdr
)))));
142 /* This is the decomposed LD_LIBRARY_PATH search path. */
143 static struct r_search_path_struct env_path_list attribute_relro
;
145 /* List of the hardware capabilities we might end up using. */
146 static const struct r_strlenpair
*capstr attribute_relro
;
147 static size_t ncapstr attribute_relro
;
148 static size_t max_capstrlen attribute_relro
;
151 /* Get the generated information about the trusted directories. */
152 #include "trusted-dirs.h"
154 static const char system_dirs
[] = SYSTEM_DIRS
;
155 static const size_t system_dirs_len
[] =
159 #define nsystem_dirs_len \
160 (sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
163 /* Local version of `strdup' function. */
165 local_strdup (const char *s
)
167 size_t len
= strlen (s
) + 1;
168 void *new = malloc (len
);
173 return (char *) memcpy (new, s
, len
);
178 is_dst (const char *start
, const char *name
, const char *str
,
179 int is_path
, int secure
)
182 bool is_curly
= false;
191 while (name
[len
] == str
[len
] && name
[len
] != '\0')
196 if (name
[len
] != '}')
199 /* Point again at the beginning of the name. */
201 /* Skip over closing curly brace and adjust for the --name. */
204 else if (name
[len
] != '\0' && name
[len
] != '/'
205 && (!is_path
|| name
[len
] != ':'))
208 if (__builtin_expect (secure
, 0)
209 && ((name
[len
] != '\0' && (!is_path
|| name
[len
] != ':'))
210 || (name
!= start
+ 1 && (!is_path
|| name
[-2] != ':'))))
218 _dl_dst_count (const char *name
, int is_path
)
220 const char *const start
= name
;
227 /* $ORIGIN is not expanded for SUID/GUID programs (except if it
228 is $ORIGIN alone) and it must always appear first in path. */
230 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
231 INTUSE(__libc_enable_secure
))) != 0
232 || (len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0
233 || (len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
236 name
= strchr (name
+ len
, '$');
238 while (name
!= NULL
);
245 _dl_dst_substitute (struct link_map
*l
, const char *name
, char *result
,
248 const char *const start
= name
;
249 char *last_elem
, *wp
;
251 /* Now fill the result path. While copying over the string we keep
252 track of the start of the last path element. When we come accross
253 a DST we copy over the value or (if the value is not available)
254 leave the entire path element out. */
255 last_elem
= wp
= result
;
259 if (__builtin_expect (*name
== '$', 0))
261 const char *repl
= NULL
;
265 if ((len
= is_dst (start
, name
, "ORIGIN", is_path
,
266 INTUSE(__libc_enable_secure
))) != 0)
268 else if ((len
= is_dst (start
, name
, "PLATFORM", is_path
, 0)) != 0)
269 repl
= GLRO(dl_platform
);
270 else if ((len
= is_dst (start
, name
, "LIB", is_path
, 0)) != 0)
273 if (repl
!= NULL
&& repl
!= (const char *) -1)
275 wp
= __stpcpy (wp
, repl
);
280 /* We cannot use this path element, the value of the
281 replacement is unknown. */
284 while (*name
!= '\0' && (!is_path
|| *name
!= ':'))
288 /* No DST we recognize. */
294 if (is_path
&& *name
== ':')
298 while (*name
!= '\0');
306 /* Return copy of argument with all recognized dynamic string tokens
307 ($ORIGIN and $PLATFORM for now) replaced. On some platforms it
308 might not be possible to determine the path from which the object
309 belonging to the map is loaded. In this case the path element
310 containing $ORIGIN is left out. */
312 expand_dynamic_string_token (struct link_map
*l
, const char *s
)
314 /* We make two runs over the string. First we determine how large the
315 resulting string is and then we copy it over. Since this is now
316 frequently executed operation we are looking here not for performance
317 but rather for code size. */
322 /* Determine the number of DST elements. */
323 cnt
= DL_DST_COUNT (s
, 1);
325 /* If we do not have to replace anything simply copy the string. */
326 if (__builtin_expect (cnt
, 0) == 0)
327 return local_strdup (s
);
329 /* Determine the length of the substituted string. */
330 total
= DL_DST_REQUIRED (l
, s
, strlen (s
), cnt
);
332 /* Allocate the necessary memory. */
333 result
= (char *) malloc (total
+ 1);
337 return _dl_dst_substitute (l
, s
, result
, 1);
341 /* Add `name' to the list of names for a particular shared object.
342 `name' is expected to have been allocated with malloc and will
343 be freed if the shared object already has this name.
344 Returns false if the object already had this name. */
347 add_name_to_object (struct link_map
*l
, const char *name
)
349 struct libname_list
*lnp
, *lastp
;
350 struct libname_list
*newname
;
354 for (lnp
= l
->l_libname
; lnp
!= NULL
; lastp
= lnp
, lnp
= lnp
->next
)
355 if (strcmp (name
, lnp
->name
) == 0)
358 name_len
= strlen (name
) + 1;
359 newname
= (struct libname_list
*) malloc (sizeof *newname
+ name_len
);
362 /* No more memory. */
363 _dl_signal_error (ENOMEM
, name
, NULL
, N_("cannot allocate name record"));
366 /* The object should have a libname set from _dl_new_object. */
367 assert (lastp
!= NULL
);
369 newname
->name
= memcpy (newname
+ 1, name
, name_len
);
370 newname
->next
= NULL
;
371 newname
->dont_free
= 0;
372 lastp
->next
= newname
;
375 /* Standard search directories. */
376 static struct r_search_path_struct rtld_search_dirs attribute_relro
;
378 static size_t max_dirnamelen
;
380 static struct r_search_path_elem
**
381 fillin_rpath (char *rpath
, struct r_search_path_elem
**result
, const char *sep
,
382 int check_trusted
, const char *what
, const char *where
)
387 while ((cp
= __strsep (&rpath
, sep
)) != NULL
)
389 struct r_search_path_elem
*dirp
;
390 size_t len
= strlen (cp
);
392 /* `strsep' can pass an empty string. This has to be
393 interpreted as `use the current directory'. */
396 static const char curwd
[] = "./";
400 /* Remove trailing slashes (except for "/"). */
401 while (len
> 1 && cp
[len
- 1] == '/')
404 /* Now add one if there is none so far. */
405 if (len
> 0 && cp
[len
- 1] != '/')
408 /* Make sure we don't use untrusted directories if we run SUID. */
409 if (__builtin_expect (check_trusted
, 0))
411 const char *trun
= system_dirs
;
415 /* All trusted directories must be complete names. */
418 for (idx
= 0; idx
< nsystem_dirs_len
; ++idx
)
420 if (len
== system_dirs_len
[idx
]
421 && memcmp (trun
, cp
, len
) == 0)
428 trun
+= system_dirs_len
[idx
] + 1;
433 /* Simply drop this directory. */
437 /* See if this directory is already known. */
438 for (dirp
= GL(dl_all_dirs
); dirp
!= NULL
; dirp
= dirp
->next
)
439 if (dirp
->dirnamelen
== len
&& memcmp (cp
, dirp
->dirname
, len
) == 0)
444 /* It is available, see whether it's on our own list. */
446 for (cnt
= 0; cnt
< nelems
; ++cnt
)
447 if (result
[cnt
] == dirp
)
451 result
[nelems
++] = dirp
;
456 enum r_dir_status init_val
;
457 size_t where_len
= where
? strlen (where
) + 1 : 0;
459 /* It's a new directory. Create an entry and add it. */
460 dirp
= (struct r_search_path_elem
*)
461 malloc (sizeof (*dirp
) + ncapstr
* sizeof (enum r_dir_status
)
462 + where_len
+ len
+ 1);
464 _dl_signal_error (ENOMEM
, NULL
, NULL
,
465 N_("cannot create cache for search path"));
467 dirp
->dirname
= ((char *) dirp
+ sizeof (*dirp
)
468 + ncapstr
* sizeof (enum r_dir_status
));
469 *((char *) __mempcpy ((char *) dirp
->dirname
, cp
, len
)) = '\0';
470 dirp
->dirnamelen
= len
;
472 if (len
> max_dirnamelen
)
473 max_dirnamelen
= len
;
475 /* We have to make sure all the relative directories are
476 never ignored. The current directory might change and
477 all our saved information would be void. */
478 init_val
= cp
[0] != '/' ? existing
: unknown
;
479 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
480 dirp
->status
[cnt
] = init_val
;
483 if (__builtin_expect (where
!= NULL
, 1))
484 dirp
->where
= memcpy ((char *) dirp
+ sizeof (*dirp
) + len
+ 1
485 + (ncapstr
* sizeof (enum r_dir_status
)),
490 dirp
->next
= GL(dl_all_dirs
);
491 GL(dl_all_dirs
) = dirp
;
493 /* Put it in the result array. */
494 result
[nelems
++] = dirp
;
498 /* Terminate the array. */
499 result
[nelems
] = NULL
;
507 decompose_rpath (struct r_search_path_struct
*sps
,
508 const char *rpath
, struct link_map
*l
, const char *what
)
510 /* Make a copy we can work with. */
511 const char *where
= l
->l_name
;
514 struct r_search_path_elem
**result
;
516 /* Initialize to please the compiler. */
517 const char *errstring
= NULL
;
519 /* First see whether we must forget the RUNPATH and RPATH from this
521 if (__builtin_expect (GLRO(dl_inhibit_rpath
) != NULL
, 0)
522 && !INTUSE(__libc_enable_secure
))
524 const char *inhp
= GLRO(dl_inhibit_rpath
);
528 const char *wp
= where
;
530 while (*inhp
== *wp
&& *wp
!= '\0')
536 if (*wp
== '\0' && (*inhp
== '\0' || *inhp
== ':'))
538 /* This object is on the list of objects for which the
539 RUNPATH and RPATH must not be used. */
540 result
= calloc (1, sizeof *result
);
544 errstring
= N_("cannot create cache for search path");
546 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
555 while (*inhp
!= '\0')
559 while (*inhp
!= '\0');
562 /* Make a writable copy. At the same time expand possible dynamic
564 copy
= expand_dynamic_string_token (l
, rpath
);
567 errstring
= N_("cannot create RUNPATH/RPATH copy");
571 /* Count the number of necessary elements in the result array. */
573 for (cp
= copy
; *cp
!= '\0'; ++cp
)
577 /* Allocate room for the result. NELEMS + 1 is an upper limit for the
578 number of necessary entries. */
579 result
= (struct r_search_path_elem
**) malloc ((nelems
+ 1 + 1)
582 goto signal_error_cache
;
584 fillin_rpath (copy
, result
, ":", 0, what
, where
);
586 /* Free the copied RPATH string. `fillin_rpath' make own copies if
591 /* The caller will change this value if we haven't used a real malloc. */
595 /* Make sure cached path information is stored in *SP
596 and return true if there are any paths to search there. */
598 cache_rpath (struct link_map
*l
,
599 struct r_search_path_struct
*sp
,
603 if (sp
->dirs
== (void *) -1)
606 if (sp
->dirs
!= NULL
)
609 if (l
->l_info
[tag
] == NULL
)
611 /* There is no path. */
612 sp
->dirs
= (void *) -1;
616 /* Make sure the cache information is available. */
617 decompose_rpath (sp
, (const char *) (D_PTR (l
, l_info
[DT_STRTAB
])
618 + l
->l_info
[tag
]->d_un
.d_val
),
626 _dl_init_paths (const char *llp
)
630 struct r_search_path_elem
*pelem
, **aelem
;
635 /* Initialize to please the compiler. */
636 const char *errstring
= NULL
;
638 /* Fill in the information about the application's RPATH and the
639 directories addressed by the LD_LIBRARY_PATH environment variable. */
641 /* Get the capabilities. */
642 capstr
= _dl_important_hwcaps (GLRO(dl_platform
), GLRO(dl_platformlen
),
643 &ncapstr
, &max_capstrlen
);
645 /* First set up the rest of the default search directory entries. */
646 aelem
= rtld_search_dirs
.dirs
= (struct r_search_path_elem
**)
647 malloc ((nsystem_dirs_len
+ 1) * sizeof (struct r_search_path_elem
*));
648 if (rtld_search_dirs
.dirs
== NULL
)
650 errstring
= N_("cannot create search path array");
652 _dl_signal_error (ENOMEM
, NULL
, NULL
, errstring
);
655 round_size
= ((2 * sizeof (struct r_search_path_elem
) - 1
656 + ncapstr
* sizeof (enum r_dir_status
))
657 / sizeof (struct r_search_path_elem
));
659 rtld_search_dirs
.dirs
[0] = (struct r_search_path_elem
*)
660 malloc ((sizeof (system_dirs
) / sizeof (system_dirs
[0]))
661 * round_size
* sizeof (struct r_search_path_elem
));
662 if (rtld_search_dirs
.dirs
[0] == NULL
)
664 errstring
= N_("cannot create cache for search path");
668 rtld_search_dirs
.malloced
= 0;
669 pelem
= GL(dl_all_dirs
) = rtld_search_dirs
.dirs
[0];
679 pelem
->what
= "system search path";
682 pelem
->dirname
= strp
;
683 pelem
->dirnamelen
= system_dirs_len
[idx
];
684 strp
+= system_dirs_len
[idx
] + 1;
686 /* System paths must be absolute. */
687 assert (pelem
->dirname
[0] == '/');
688 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
689 pelem
->status
[cnt
] = unknown
;
691 pelem
->next
= (++idx
== nsystem_dirs_len
? NULL
: (pelem
+ round_size
));
695 while (idx
< nsystem_dirs_len
);
697 max_dirnamelen
= SYSTEM_DIRS_MAX_LEN
;
701 /* This points to the map of the main object. */
702 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
705 assert (l
->l_type
!= lt_loaded
);
707 if (l
->l_info
[DT_RUNPATH
])
709 /* Allocate room for the search path and fill in information
711 decompose_rpath (&l
->l_runpath_dirs
,
712 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
713 + l
->l_info
[DT_RUNPATH
]->d_un
.d_val
),
716 /* The RPATH is ignored. */
717 l
->l_rpath_dirs
.dirs
= (void *) -1;
721 l
->l_runpath_dirs
.dirs
= (void *) -1;
723 if (l
->l_info
[DT_RPATH
])
725 /* Allocate room for the search path and fill in information
727 decompose_rpath (&l
->l_rpath_dirs
,
728 (const void *) (D_PTR (l
, l_info
[DT_STRTAB
])
729 + l
->l_info
[DT_RPATH
]->d_un
.d_val
),
731 l
->l_rpath_dirs
.malloced
= 0;
734 l
->l_rpath_dirs
.dirs
= (void *) -1;
739 if (llp
!= NULL
&& *llp
!= '\0')
742 const char *cp
= llp
;
743 char *llp_tmp
= strdupa (llp
);
745 /* Decompose the LD_LIBRARY_PATH contents. First determine how many
750 if (*cp
== ':' || *cp
== ';')
755 env_path_list
.dirs
= (struct r_search_path_elem
**)
756 malloc ((nllp
+ 1) * sizeof (struct r_search_path_elem
*));
757 if (env_path_list
.dirs
== NULL
)
759 errstring
= N_("cannot create cache for search path");
763 (void) fillin_rpath (llp_tmp
, env_path_list
.dirs
, ":;",
764 INTUSE(__libc_enable_secure
), "LD_LIBRARY_PATH",
767 if (env_path_list
.dirs
[0] == NULL
)
769 free (env_path_list
.dirs
);
770 env_path_list
.dirs
= (void *) -1;
773 env_path_list
.malloced
= 0;
776 env_path_list
.dirs
= (void *) -1;
778 /* Remember the last search directory added at startup. */
779 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
784 __attribute__ ((noreturn
, noinline
))
785 lose (int code
, int fd
, const char *name
, char *realname
, struct link_map
*l
,
788 /* The file might already be closed. */
793 /* Remove the stillborn object from the list and free it. */
794 assert (l
->l_next
== NULL
);
795 if (l
->l_prev
== NULL
)
796 /* No other module loaded. This happens only in the static library,
797 or in rtld under --verify. */
798 GL(dl_ns
)[l
->l_ns
]._ns_loaded
= NULL
;
800 l
->l_prev
->l_next
= NULL
;
801 --GL(dl_ns
)[l
->l_ns
]._ns_nloaded
;
805 _dl_signal_error (code
, name
, NULL
, msg
);
809 /* Map in the shared object NAME, actually located in REALNAME, and already
812 #ifndef EXTERNAL_MAP_FROM_FD
816 _dl_map_object_from_fd (const char *name
, int fd
, struct filebuf
*fbp
,
817 char *realname
, struct link_map
*loader
, int l_type
,
818 int mode
, void **stack_endp
, Lmid_t nsid
)
820 struct link_map
*l
= NULL
;
821 const ElfW(Ehdr
) *header
;
822 const ElfW(Phdr
) *phdr
;
823 const ElfW(Phdr
) *ph
;
827 /* Initialize to keep the compiler happy. */
828 const char *errstring
= NULL
;
830 struct r_debug
*r
= _dl_debug_initialize (0, nsid
);
831 bool make_consistent
= false;
833 /* Get file information. */
834 if (__builtin_expect (__fxstat64 (_STAT_VER
, fd
, &st
) < 0, 0))
836 errstring
= N_("cannot stat shared object");
842 r
->r_state
= RT_CONSISTENT
;
846 lose (errval
, fd
, name
, realname
, l
, errstring
);
849 /* Look again to see if the real name matched another already loaded. */
850 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
851 if (l
->l_removed
== 0 && l
->l_ino
== st
.st_ino
&& l
->l_dev
== st
.st_dev
)
853 /* The object is already loaded.
854 Just bump its reference count and return it. */
857 /* If the name is not in the list of names for this object add
860 add_name_to_object (l
, name
);
866 /* When loading into a namespace other than the base one we must
867 avoid loading ld.so since there can only be one copy. Ever. */
868 if (__builtin_expect (nsid
!= LM_ID_BASE
, 0)
869 && ((st
.st_ino
== GL(dl_rtld_map
).l_ino
870 && st
.st_dev
== GL(dl_rtld_map
).l_dev
)
871 || _dl_name_match_p (name
, &GL(dl_rtld_map
))))
873 /* This is indeed ld.so. Create a new link_map which refers to
874 the real one for almost everything. */
875 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
879 /* Refer to the real descriptor. */
880 l
->l_real
= &GL(dl_rtld_map
);
882 /* No need to bump the refcount of the real object, ld.so will
883 never be unloaded. */
890 if (mode
& RTLD_NOLOAD
)
891 /* We are not supposed to load the object unless it is already
892 loaded. So return now. */
895 /* Print debugging message. */
896 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
897 _dl_debug_printf ("file=%s [%lu]; generating link map\n", name
, nsid
);
899 /* This is the ELF header. We read it in `open_verify'. */
900 header
= (void *) fbp
->buf
;
904 if (_dl_zerofd
== -1)
906 _dl_zerofd
= _dl_sysdep_open_zero_fill ();
907 if (_dl_zerofd
== -1)
910 _dl_signal_error (errno
, NULL
, NULL
,
911 N_("cannot open zero fill device"));
916 /* Signal that we are going to add new objects. */
917 if (r
->r_state
== RT_CONSISTENT
)
920 /* Auditing checkpoint: we are going to add new objects. */
921 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
923 struct link_map
*head
= GL(dl_ns
)[nsid
]._ns_loaded
;
924 /* Do not call the functions for any auditing object. */
925 if (head
->l_auditing
== 0)
927 struct audit_ifaces
*afct
= GLRO(dl_audit
);
928 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
930 if (afct
->activity
!= NULL
)
931 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
939 /* Notify the debugger we have added some objects. We need to
940 call _dl_debug_initialize in a static program in case dynamic
941 linking has not been used before. */
944 make_consistent
= true;
947 assert (r
->r_state
== RT_ADD
);
949 /* Enter the new object in the list of loaded objects. */
950 l
= _dl_new_object (realname
, name
, l_type
, loader
, mode
, nsid
);
951 if (__builtin_expect (l
== NULL
, 0))
956 errstring
= N_("cannot create shared object descriptor");
957 goto call_lose_errno
;
960 /* Extract the remaining details we need from the ELF header
961 and then read in the program header table. */
962 l
->l_entry
= header
->e_entry
;
963 type
= header
->e_type
;
964 l
->l_phnum
= header
->e_phnum
;
966 maplength
= header
->e_phnum
* sizeof (ElfW(Phdr
));
967 if (header
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
968 phdr
= (void *) (fbp
->buf
+ header
->e_phoff
);
971 phdr
= alloca (maplength
);
972 __lseek (fd
, header
->e_phoff
, SEEK_SET
);
973 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
975 errstring
= N_("cannot read file data");
976 goto call_lose_errno
;
980 /* Presumed absent PT_GNU_STACK. */
981 uint_fast16_t stack_flags
= PF_R
|PF_W
|PF_X
;
984 /* Scan the program header table, collecting its load commands. */
987 ElfW(Addr
) mapstart
, mapend
, dataend
, allocend
;
990 } loadcmds
[l
->l_phnum
], *c
;
991 size_t nloadcmds
= 0;
992 bool has_holes
= false;
994 /* The struct is initialized to zero so this is not necessary:
998 for (ph
= phdr
; ph
< &phdr
[l
->l_phnum
]; ++ph
)
1001 /* These entries tell us where to find things once the file's
1002 segments are mapped in. We record the addresses it says
1003 verbatim, and later correct for the run-time load address. */
1005 l
->l_ld
= (void *) ph
->p_vaddr
;
1006 l
->l_ldnum
= ph
->p_memsz
/ sizeof (ElfW(Dyn
));
1010 l
->l_phdr
= (void *) ph
->p_vaddr
;
1014 /* A load command tells us to map in part of the file.
1015 We record the load commands and process them all later. */
1016 if (__builtin_expect ((ph
->p_align
& (GLRO(dl_pagesize
) - 1)) != 0,
1019 errstring
= N_("ELF load command alignment not page-aligned");
1022 if (__builtin_expect (((ph
->p_vaddr
- ph
->p_offset
)
1023 & (ph
->p_align
- 1)) != 0, 0))
1026 = N_("ELF load command address/offset not properly aligned");
1030 c
= &loadcmds
[nloadcmds
++];
1031 c
->mapstart
= ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1);
1032 c
->mapend
= ((ph
->p_vaddr
+ ph
->p_filesz
+ GLRO(dl_pagesize
) - 1)
1033 & ~(GLRO(dl_pagesize
) - 1));
1034 c
->dataend
= ph
->p_vaddr
+ ph
->p_filesz
;
1035 c
->allocend
= ph
->p_vaddr
+ ph
->p_memsz
;
1036 c
->mapoff
= ph
->p_offset
& ~(GLRO(dl_pagesize
) - 1);
1038 /* Determine whether there is a gap between the last segment
1040 if (nloadcmds
> 1 && c
[-1].mapend
!= c
->mapstart
)
1043 /* Optimize a common case. */
1044 #if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
1045 c
->prot
= (PF_TO_PROT
1046 >> ((ph
->p_flags
& (PF_R
| PF_W
| PF_X
)) * 4)) & 0xf;
1049 if (ph
->p_flags
& PF_R
)
1050 c
->prot
|= PROT_READ
;
1051 if (ph
->p_flags
& PF_W
)
1052 c
->prot
|= PROT_WRITE
;
1053 if (ph
->p_flags
& PF_X
)
1054 c
->prot
|= PROT_EXEC
;
1060 if (ph
->p_memsz
== 0)
1061 /* Nothing to do for an empty segment. */
1064 l
->l_tls_blocksize
= ph
->p_memsz
;
1065 l
->l_tls_align
= ph
->p_align
;
1066 if (ph
->p_align
== 0)
1067 l
->l_tls_firstbyte_offset
= 0;
1069 l
->l_tls_firstbyte_offset
= ph
->p_vaddr
& (ph
->p_align
- 1);
1070 l
->l_tls_initimage_size
= ph
->p_filesz
;
1071 /* Since we don't know the load address yet only store the
1072 offset. We will adjust it later. */
1073 l
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1075 /* If not loading the initial set of shared libraries,
1076 check whether we should permit loading a TLS segment. */
1077 if (__builtin_expect (l
->l_type
== lt_library
, 1)
1078 /* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
1079 not set up TLS data structures, so don't use them now. */
1080 || __builtin_expect (GL(dl_tls_dtv_slotinfo_list
) != NULL
, 1))
1082 /* Assign the next available module ID. */
1083 l
->l_tls_modid
= _dl_next_tls_modid ();
1088 if (l
->l_prev
== NULL
|| (mode
& __RTLD_AUDIT
) != 0)
1089 /* We are loading the executable itself when the dynamic linker
1090 was executed directly. The setup will happen later. */
1093 /* In a static binary there is no way to tell if we dynamically
1094 loaded libpthread. */
1095 if (GL(dl_error_catch_tsd
) == &_dl_initial_error_catch_tsd
)
1098 /* We have not yet loaded libpthread.
1099 We can do the TLS setup right now! */
1103 /* The first call allocates TLS bookkeeping data structures.
1104 Then we allocate the TCB for the initial thread. */
1105 if (__builtin_expect (_dl_tls_setup (), 0)
1106 || __builtin_expect ((tcb
= _dl_allocate_tls (NULL
)) == NULL
,
1111 cannot allocate TLS data structures for initial thread");
1115 /* Now we install the TCB in the thread register. */
1116 errstring
= TLS_INIT_TP (tcb
, 0);
1117 if (__builtin_expect (errstring
== NULL
, 1))
1119 /* Now we are all good. */
1120 l
->l_tls_modid
= ++GL(dl_tls_max_dtv_idx
);
1124 /* The kernel is too old or somesuch. */
1126 _dl_deallocate_tls (tcb
, 1);
1131 /* Uh-oh, the binary expects TLS support but we cannot
1134 errstring
= N_("cannot handle TLS data");
1139 stack_flags
= ph
->p_flags
;
1143 l
->l_relro_addr
= ph
->p_vaddr
;
1144 l
->l_relro_size
= ph
->p_memsz
;
1148 if (__builtin_expect (nloadcmds
== 0, 0))
1150 /* This only happens for a bogus object that will be caught with
1151 another error below. But we don't want to go through the
1152 calculations below using NLOADCMDS - 1. */
1153 errstring
= N_("object file has no loadable segments");
1157 /* Now process the load commands and map segments into memory. */
1160 /* Length of the sections to be loaded. */
1161 maplength
= loadcmds
[nloadcmds
- 1].allocend
- c
->mapstart
;
1163 if (__builtin_expect (type
, ET_DYN
) == ET_DYN
)
1165 /* This is a position-independent shared object. We can let the
1166 kernel map it anywhere it likes, but we must have space for all
1167 the segments in their specified positions relative to the first.
1168 So we map the first segment without MAP_FIXED, but with its
1169 extent increased to cover all the segments. Then we remove
1170 access from excess portion, and there is known sufficient space
1171 there to remap from the later segments.
1173 As a refinement, sometimes we have an address that we would
1174 prefer to map such objects at; but this is only a preference,
1175 the OS can do whatever it likes. */
1177 mappref
= (ELF_PREFERRED_ADDRESS (loader
, maplength
,
1178 c
->mapstart
& GLRO(dl_use_load_bias
))
1179 - MAP_BASE_ADDR (l
));
1181 /* Remember which part of the address space this object uses. */
1182 l
->l_map_start
= (ElfW(Addr
)) __mmap ((void *) mappref
, maplength
,
1184 MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1186 if (__builtin_expect ((void *) l
->l_map_start
== MAP_FAILED
, 0))
1189 errstring
= N_("failed to map segment from shared object");
1190 goto call_lose_errno
;
1193 l
->l_map_end
= l
->l_map_start
+ maplength
;
1194 l
->l_addr
= l
->l_map_start
- c
->mapstart
;
1197 /* Change protection on the excess portion to disallow all access;
1198 the portions we do not remap later will be inaccessible as if
1199 unallocated. Then jump into the normal segment-mapping loop to
1200 handle the portion of the segment past the end of the file
1202 __mprotect ((caddr_t
) (l
->l_addr
+ c
->mapend
),
1203 loadcmds
[nloadcmds
- 1].allocend
- c
->mapend
,
1209 /* This object is loaded at a fixed address. This must never
1210 happen for objects loaded with dlopen(). */
1211 if (__builtin_expect ((mode
& __RTLD_OPENEXEC
) == 0, 0))
1213 errstring
= N_("cannot dynamically load executable");
1217 /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
1219 ELF_FIXED_ADDRESS (loader
, c
->mapstart
);
1222 /* Remember which part of the address space this object uses. */
1223 l
->l_map_start
= c
->mapstart
+ l
->l_addr
;
1224 l
->l_map_end
= l
->l_map_start
+ maplength
;
1226 while (c
< &loadcmds
[nloadcmds
])
1228 if (c
->mapend
> c
->mapstart
1229 /* Map the segment contents from the file. */
1230 && (__mmap ((void *) (l
->l_addr
+ c
->mapstart
),
1231 c
->mapend
- c
->mapstart
, c
->prot
,
1232 MAP_FIXED
|MAP_COPY
|MAP_FILE
|MAP_DENYWRITE
,
1238 if (c
->prot
& PROT_EXEC
)
1239 l
->l_text_end
= l
->l_addr
+ c
->mapend
;
1242 && (ElfW(Off
)) c
->mapoff
<= header
->e_phoff
1243 && ((size_t) (c
->mapend
- c
->mapstart
+ c
->mapoff
)
1244 >= header
->e_phoff
+ header
->e_phnum
* sizeof (ElfW(Phdr
))))
1245 /* Found the program header in this segment. */
1246 l
->l_phdr
= (void *) (c
->mapstart
+ header
->e_phoff
- c
->mapoff
);
1248 if (c
->allocend
> c
->dataend
)
1250 /* Extra zero pages should appear at the end of this segment,
1251 after the data mapped from the file. */
1252 ElfW(Addr
) zero
, zeroend
, zeropage
;
1254 zero
= l
->l_addr
+ c
->dataend
;
1255 zeroend
= l
->l_addr
+ c
->allocend
;
1256 zeropage
= ((zero
+ GLRO(dl_pagesize
) - 1)
1257 & ~(GLRO(dl_pagesize
) - 1));
1259 if (zeroend
< zeropage
)
1260 /* All the extra data is in the last page of the segment.
1261 We can just zero it. */
1264 if (zeropage
> zero
)
1266 /* Zero the final part of the last page of the segment. */
1267 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1270 if (__mprotect ((caddr_t
) (zero
1271 & ~(GLRO(dl_pagesize
) - 1)),
1272 GLRO(dl_pagesize
), c
->prot
|PROT_WRITE
) < 0)
1274 errstring
= N_("cannot change memory protections");
1275 goto call_lose_errno
;
1278 memset ((void *) zero
, '\0', zeropage
- zero
);
1279 if (__builtin_expect ((c
->prot
& PROT_WRITE
) == 0, 0))
1280 __mprotect ((caddr_t
) (zero
& ~(GLRO(dl_pagesize
) - 1)),
1281 GLRO(dl_pagesize
), c
->prot
);
1284 if (zeroend
> zeropage
)
1286 /* Map the remaining zero pages in from the zero fill FD. */
1288 mapat
= __mmap ((caddr_t
) zeropage
, zeroend
- zeropage
,
1289 c
->prot
, MAP_ANON
|MAP_PRIVATE
|MAP_FIXED
,
1291 if (__builtin_expect (mapat
== MAP_FAILED
, 0))
1293 errstring
= N_("cannot map zero-fill pages");
1294 goto call_lose_errno
;
1305 if (__builtin_expect (type
== ET_DYN
, 0))
1307 errstring
= N_("object file has no dynamic section");
1312 l
->l_ld
= (ElfW(Dyn
) *) ((ElfW(Addr
)) l
->l_ld
+ l
->l_addr
);
1314 elf_get_dynamic_info (l
, NULL
);
1316 /* Make sure we are not dlopen'ing an object that has the
1317 DF_1_NOOPEN flag set. */
1318 if (__builtin_expect (l
->l_flags_1
& DF_1_NOOPEN
, 0)
1319 && (mode
& __RTLD_DLOPEN
))
1321 /* We are not supposed to load this object. Free all resources. */
1322 __munmap ((void *) l
->l_map_start
, l
->l_map_end
- l
->l_map_start
);
1324 if (!l
->l_libname
->dont_free
)
1325 free (l
->l_libname
);
1327 if (l
->l_phdr_allocated
)
1328 free ((void *) l
->l_phdr
);
1330 errstring
= N_("shared object cannot be dlopen()ed");
1334 if (l
->l_phdr
== NULL
)
1336 /* The program header is not contained in any of the segments.
1337 We have to allocate memory ourself and copy it over from out
1339 ElfW(Phdr
) *newp
= (ElfW(Phdr
) *) malloc (header
->e_phnum
1340 * sizeof (ElfW(Phdr
)));
1343 errstring
= N_("cannot allocate memory for program header");
1344 goto call_lose_errno
;
1347 l
->l_phdr
= memcpy (newp
, phdr
,
1348 (header
->e_phnum
* sizeof (ElfW(Phdr
))));
1349 l
->l_phdr_allocated
= 1;
1352 /* Adjust the PT_PHDR value by the runtime load address. */
1353 l
->l_phdr
= (ElfW(Phdr
) *) ((ElfW(Addr
)) l
->l_phdr
+ l
->l_addr
);
1355 if (__builtin_expect ((stack_flags
&~ GL(dl_stack_flags
)) & PF_X
, 0))
1357 /* The stack is presently not executable, but this module
1358 requires that it be executable. We must change the
1359 protection of the variable which contains the flags used in
1360 the mprotect calls. */
1362 if ((mode
& (__RTLD_DLOPEN
| __RTLD_AUDIT
)) == __RTLD_DLOPEN
)
1364 uintptr_t p
= ((uintptr_t) &__stack_prot
) & ~(GLRO(dl_pagesize
) - 1);
1365 size_t s
= (uintptr_t) &__stack_prot
- p
+ sizeof (int);
1367 __mprotect ((void *) p
, s
, PROT_READ
|PROT_WRITE
);
1368 if (__builtin_expect (__check_caller (RETURN_ADDRESS (0),
1371 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1372 __mprotect ((void *) p
, s
, PROT_READ
);
1376 __stack_prot
|= PROT_READ
|PROT_WRITE
|PROT_EXEC
;
1378 #ifdef check_consistency
1379 check_consistency ();
1382 errval
= (*GL(dl_make_stack_executable_hook
)) (stack_endp
);
1386 cannot enable executable stack as shared object requires");
1392 /* Adjust the address of the TLS initialization image. */
1393 if (l
->l_tls_initimage
!= NULL
)
1394 l
->l_tls_initimage
= (char *) l
->l_tls_initimage
+ l
->l_addr
;
1397 /* We are done mapping in the file. We no longer need the descriptor. */
1398 if (__builtin_expect (__close (fd
) != 0, 0))
1400 errstring
= N_("cannot close file descriptor");
1401 goto call_lose_errno
;
1403 /* Signal that we closed the file. */
1406 if (l
->l_type
== lt_library
&& type
== ET_EXEC
)
1407 l
->l_type
= lt_executable
;
1409 l
->l_entry
+= l
->l_addr
;
1411 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
1412 _dl_debug_printf ("\
1413 dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
1414 entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
1415 (int) sizeof (void *) * 2,
1416 (unsigned long int) l
->l_ld
,
1417 (int) sizeof (void *) * 2,
1418 (unsigned long int) l
->l_addr
,
1419 (int) sizeof (void *) * 2, maplength
,
1420 (int) sizeof (void *) * 2,
1421 (unsigned long int) l
->l_entry
,
1422 (int) sizeof (void *) * 2,
1423 (unsigned long int) l
->l_phdr
,
1424 (int) sizeof (void *) * 2, l
->l_phnum
);
1426 /* Set up the symbol hash table. */
1429 /* If this object has DT_SYMBOLIC set modify now its scope. We don't
1430 have to do this for the main map. */
1431 if ((mode
& RTLD_DEEPBIND
) == 0
1432 && __builtin_expect (l
->l_info
[DT_SYMBOLIC
] != NULL
, 0)
1433 && &l
->l_searchlist
!= l
->l_scope
[0])
1435 /* Create an appropriate searchlist. It contains only this map.
1436 This is the definition of DT_SYMBOLIC in SysVr4. */
1437 l
->l_symbolic_searchlist
.r_list
=
1438 (struct link_map
**) malloc (sizeof (struct link_map
*));
1440 if (l
->l_symbolic_searchlist
.r_list
== NULL
)
1442 errstring
= N_("cannot create searchlist");
1443 goto call_lose_errno
;
1446 l
->l_symbolic_searchlist
.r_list
[0] = l
;
1447 l
->l_symbolic_searchlist
.r_nlist
= 1;
1449 /* Now move the existing entries one back. */
1450 memmove (&l
->l_scope
[1], &l
->l_scope
[0],
1451 (l
->l_scope_max
- 1) * sizeof (l
->l_scope
[0]));
1453 /* Now add the new entry. */
1454 l
->l_scope
[0] = &l
->l_symbolic_searchlist
;
1457 /* Remember whether this object must be initialized first. */
1458 if (l
->l_flags_1
& DF_1_INITFIRST
)
1459 GL(dl_initfirst
) = l
;
1461 /* Finally the file information. */
1462 l
->l_dev
= st
.st_dev
;
1463 l
->l_ino
= st
.st_ino
;
1465 /* When we profile the SONAME might be needed for something else but
1466 loading. Add it right away. */
1467 if (__builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1468 && l
->l_info
[DT_SONAME
] != NULL
)
1469 add_name_to_object (l
, ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1470 + l
->l_info
[DT_SONAME
]->d_un
.d_val
));
1473 /* Auditing checkpoint: we have a new object. */
1474 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1475 && !GL(dl_ns
)[l
->l_ns
]._ns_loaded
->l_auditing
)
1477 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1478 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1480 if (afct
->objopen
!= NULL
)
1482 l
->l_audit
[cnt
].bindflags
1483 = afct
->objopen (l
, nsid
, &l
->l_audit
[cnt
].cookie
);
1485 l
->l_audit_any_plt
|= l
->l_audit
[cnt
].bindflags
!= 0;
1496 /* Print search path. */
1498 print_search_path (struct r_search_path_elem
**list
,
1499 const char *what
, const char *name
)
1501 char buf
[max_dirnamelen
+ max_capstrlen
];
1504 _dl_debug_printf (" search path=");
1506 while (*list
!= NULL
&& (*list
)->what
== what
) /* Yes, ==. */
1508 char *endp
= __mempcpy (buf
, (*list
)->dirname
, (*list
)->dirnamelen
);
1511 for (cnt
= 0; cnt
< ncapstr
; ++cnt
)
1512 if ((*list
)->status
[cnt
] != nonexisting
)
1514 char *cp
= __mempcpy (endp
, capstr
[cnt
].str
, capstr
[cnt
].len
);
1515 if (cp
== buf
|| (cp
== buf
+ 1 && buf
[0] == '/'))
1520 _dl_debug_printf_c (first
? "%s" : ":%s", buf
);
1528 _dl_debug_printf_c ("\t\t(%s from file %s)\n", what
,
1529 name
[0] ? name
: rtld_progname
);
1531 _dl_debug_printf_c ("\t\t(%s)\n", what
);
1534 /* Open a file and verify it is an ELF file for this architecture. We
1535 ignore only ELF files for other architectures. Non-ELF files and
1536 ELF files with different header information cause fatal errors since
1537 this could mean there is something wrong in the installation and the
1538 user might want to know about this. */
1540 open_verify (const char *name
, struct filebuf
*fbp
, struct link_map
*loader
,
1543 /* This is the expected ELF header. */
1544 #define ELF32_CLASS ELFCLASS32
1545 #define ELF64_CLASS ELFCLASS64
1546 #ifndef VALID_ELF_HEADER
1547 # define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
1548 # define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
1549 # define VALID_ELF_ABIVERSION(ver) (ver == 0)
1551 static const unsigned char expected
[EI_PAD
] =
1553 [EI_MAG0
] = ELFMAG0
,
1554 [EI_MAG1
] = ELFMAG1
,
1555 [EI_MAG2
] = ELFMAG2
,
1556 [EI_MAG3
] = ELFMAG3
,
1557 [EI_CLASS
] = ELFW(CLASS
),
1558 [EI_DATA
] = byteorder
,
1559 [EI_VERSION
] = EV_CURRENT
,
1560 [EI_OSABI
] = ELFOSABI_SYSV
,
1565 ElfW(Word
) vendorlen
;
1569 } expected_note
= { 4, 16, 1, "GNU" };
1570 /* Initialize it to make the compiler happy. */
1571 const char *errstring
= NULL
;
1575 /* Give the auditing libraries a chance. */
1576 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0) && whatcode
!= 0
1577 && loader
->l_auditing
== 0)
1579 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1580 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1582 if (afct
->objsearch
!= NULL
)
1584 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1587 /* Ignore the path. */
1596 /* Open the file. We always open files read-only. */
1597 int fd
= __open (name
, O_RDONLY
);
1601 ElfW(Phdr
) *phdr
, *ph
;
1602 ElfW(Word
) *abi_note
, abi_note_buf
[8];
1603 unsigned int osversion
;
1606 /* We successfully openened the file. Now verify it is a file
1609 fbp
->len
= __libc_read (fd
, fbp
->buf
, sizeof (fbp
->buf
));
1611 /* This is where the ELF header is loaded. */
1612 assert (sizeof (fbp
->buf
) > sizeof (ElfW(Ehdr
)));
1613 ehdr
= (ElfW(Ehdr
) *) fbp
->buf
;
1615 /* Now run the tests. */
1616 if (__builtin_expect (fbp
->len
< (ssize_t
) sizeof (ElfW(Ehdr
)), 0))
1619 errstring
= (errval
== 0
1620 ? N_("file too short") : N_("cannot read file data"));
1622 lose (errval
, fd
, name
, NULL
, NULL
, errstring
);
1625 /* See whether the ELF header is what we expect. */
1626 if (__builtin_expect (! VALID_ELF_HEADER (ehdr
->e_ident
, expected
,
1629 /* Something is wrong. */
1630 if (*(Elf32_Word
*) &ehdr
->e_ident
!=
1631 #if BYTE_ORDER == LITTLE_ENDIAN
1632 ((ELFMAG0
<< (EI_MAG0
* 8)) |
1633 (ELFMAG1
<< (EI_MAG1
* 8)) |
1634 (ELFMAG2
<< (EI_MAG2
* 8)) |
1635 (ELFMAG3
<< (EI_MAG3
* 8)))
1637 ((ELFMAG0
<< (EI_MAG3
* 8)) |
1638 (ELFMAG1
<< (EI_MAG2
* 8)) |
1639 (ELFMAG2
<< (EI_MAG1
* 8)) |
1640 (ELFMAG3
<< (EI_MAG0
* 8)))
1643 errstring
= N_("invalid ELF header");
1644 else if (ehdr
->e_ident
[EI_CLASS
] != ELFW(CLASS
))
1645 /* This is not a fatal error. On architectures where
1646 32-bit and 64-bit binaries can be run this might
1649 else if (ehdr
->e_ident
[EI_DATA
] != byteorder
)
1651 if (BYTE_ORDER
== BIG_ENDIAN
)
1652 errstring
= N_("ELF file data encoding not big-endian");
1654 errstring
= N_("ELF file data encoding not little-endian");
1656 else if (ehdr
->e_ident
[EI_VERSION
] != EV_CURRENT
)
1658 = N_("ELF file version ident does not match current one");
1659 /* XXX We should be able so set system specific versions which are
1661 else if (!VALID_ELF_OSABI (ehdr
->e_ident
[EI_OSABI
]))
1662 errstring
= N_("ELF file OS ABI invalid");
1663 else if (!VALID_ELF_ABIVERSION (ehdr
->e_ident
[EI_ABIVERSION
]))
1664 errstring
= N_("ELF file ABI version invalid");
1666 /* Otherwise we don't know what went wrong. */
1667 errstring
= N_("internal error");
1672 if (__builtin_expect (ehdr
->e_version
, EV_CURRENT
) != EV_CURRENT
)
1674 errstring
= N_("ELF file version does not match current one");
1677 if (! __builtin_expect (elf_machine_matches_host (ehdr
), 1))
1679 else if (__builtin_expect (ehdr
->e_type
, ET_DYN
) != ET_DYN
1680 && __builtin_expect (ehdr
->e_type
, ET_EXEC
) != ET_EXEC
)
1682 errstring
= N_("only ET_DYN and ET_EXEC can be loaded");
1685 else if (__builtin_expect (ehdr
->e_phentsize
, sizeof (ElfW(Phdr
)))
1686 != sizeof (ElfW(Phdr
)))
1688 errstring
= N_("ELF file's phentsize not the expected size");
1692 maplength
= ehdr
->e_phnum
* sizeof (ElfW(Phdr
));
1693 if (ehdr
->e_phoff
+ maplength
<= (size_t) fbp
->len
)
1694 phdr
= (void *) (fbp
->buf
+ ehdr
->e_phoff
);
1697 phdr
= alloca (maplength
);
1698 __lseek (fd
, ehdr
->e_phoff
, SEEK_SET
);
1699 if ((size_t) __libc_read (fd
, (void *) phdr
, maplength
) != maplength
)
1703 errstring
= N_("cannot read file data");
1708 /* Check .note.ABI-tag if present. */
1709 for (ph
= phdr
; ph
< &phdr
[ehdr
->e_phnum
]; ++ph
)
1710 if (ph
->p_type
== PT_NOTE
&& ph
->p_filesz
== 32 && ph
->p_align
>= 4)
1712 if (ph
->p_offset
+ 32 <= (size_t) fbp
->len
)
1713 abi_note
= (void *) (fbp
->buf
+ ph
->p_offset
);
1716 __lseek (fd
, ph
->p_offset
, SEEK_SET
);
1717 if (__libc_read (fd
, (void *) abi_note_buf
, 32) != 32)
1720 abi_note
= abi_note_buf
;
1723 if (memcmp (abi_note
, &expected_note
, sizeof (expected_note
)))
1726 osversion
= (abi_note
[5] & 0xff) * 65536
1727 + (abi_note
[6] & 0xff) * 256
1728 + (abi_note
[7] & 0xff);
1729 if (abi_note
[4] != __ABI_TAG_OS
1730 || (GLRO(dl_osversion
) && GLRO(dl_osversion
) < osversion
))
1734 __set_errno (ENOENT
);
1745 /* Try to open NAME in one of the directories in *DIRSP.
1746 Return the fd, or -1. If successful, fill in *REALNAME
1747 with the malloc'd full directory name. If it turns out
1748 that none of the directories in *DIRSP exists, *DIRSP is
1749 replaced with (void *) -1, and the old value is free()d
1750 if MAY_FREE_DIRS is true. */
1753 open_path (const char *name
, size_t namelen
, int preloaded
,
1754 struct r_search_path_struct
*sps
, char **realname
,
1755 struct filebuf
*fbp
, struct link_map
*loader
, int whatcode
)
1757 struct r_search_path_elem
**dirs
= sps
->dirs
;
1760 const char *current_what
= NULL
;
1763 if (__builtin_expect (dirs
== NULL
, 0))
1764 /* We're called before _dl_init_paths when loading the main executable
1765 given on the command line when rtld is run directly. */
1768 buf
= alloca (max_dirnamelen
+ max_capstrlen
+ namelen
);
1771 struct r_search_path_elem
*this_dir
= *dirs
;
1778 /* If we are debugging the search for libraries print the path
1779 now if it hasn't happened now. */
1780 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0)
1781 && current_what
!= this_dir
->what
)
1783 current_what
= this_dir
->what
;
1784 print_search_path (dirs
, current_what
, this_dir
->where
);
1787 edp
= (char *) __mempcpy (buf
, this_dir
->dirname
, this_dir
->dirnamelen
);
1788 for (cnt
= 0; fd
== -1 && cnt
< ncapstr
; ++cnt
)
1790 /* Skip this directory if we know it does not exist. */
1791 if (this_dir
->status
[cnt
] == nonexisting
)
1795 ((char *) __mempcpy (__mempcpy (edp
, capstr
[cnt
].str
,
1800 /* Print name we try if this is wanted. */
1801 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1802 _dl_debug_printf (" trying file=%s\n", buf
);
1804 fd
= open_verify (buf
, fbp
, loader
, whatcode
);
1805 if (this_dir
->status
[cnt
] == unknown
)
1808 this_dir
->status
[cnt
] = existing
;
1809 /* Do not update the directory information when loading
1810 auditing code. We must try to disturb the program as
1811 little as possible. */
1812 else if (loader
== NULL
1813 || GL(dl_ns
)[loader
->l_ns
]._ns_loaded
->l_audit
== 0)
1815 /* We failed to open machine dependent library. Let's
1816 test whether there is any directory at all. */
1819 buf
[buflen
- namelen
- 1] = '\0';
1821 if (__xstat64 (_STAT_VER
, buf
, &st
) != 0
1822 || ! S_ISDIR (st
.st_mode
))
1823 /* The directory does not exist or it is no directory. */
1824 this_dir
->status
[cnt
] = nonexisting
;
1826 this_dir
->status
[cnt
] = existing
;
1830 /* Remember whether we found any existing directory. */
1831 here_any
|= this_dir
->status
[cnt
] != nonexisting
;
1833 if (fd
!= -1 && __builtin_expect (preloaded
, 0)
1834 && INTUSE(__libc_enable_secure
))
1836 /* This is an extra security effort to make sure nobody can
1837 preload broken shared objects which are in the trusted
1838 directories and so exploit the bugs. */
1841 if (__fxstat64 (_STAT_VER
, fd
, &st
) != 0
1842 || (st
.st_mode
& S_ISUID
) == 0)
1844 /* The shared object cannot be tested for being SUID
1845 or this bit is not set. In this case we must not
1849 /* We simply ignore the file, signal this by setting
1850 the error value which would have been set by `open'. */
1858 *realname
= (char *) malloc (buflen
);
1859 if (*realname
!= NULL
)
1861 memcpy (*realname
, buf
, buflen
);
1866 /* No memory for the name, we certainly won't be able
1867 to load and link it. */
1872 if (here_any
&& (err
= errno
) != ENOENT
&& err
!= EACCES
)
1873 /* The file exists and is readable, but something went wrong. */
1876 /* Remember whether we found anything. */
1879 while (*++dirs
!= NULL
);
1881 /* Remove the whole path if none of the directories exists. */
1882 if (__builtin_expect (! any
, 0))
1884 /* Paths which were allocated using the minimal malloc() in ld.so
1885 must not be freed using the general free() in libc. */
1889 /* rtld_search_dirs is attribute_relro, therefore avoid writing
1891 if (sps
!= &rtld_search_dirs
)
1893 sps
->dirs
= (void *) -1;
1899 /* Map in the shared object file NAME. */
1903 _dl_map_object (struct link_map
*loader
, const char *name
, int preloaded
,
1904 int type
, int trace_mode
, int mode
, Lmid_t nsid
)
1913 assert (nsid
< DL_NNS
);
1915 /* Look for this name among those already loaded. */
1916 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
; l
= l
->l_next
)
1918 /* If the requested name matches the soname of a loaded object,
1919 use that object. Elide this check for names that have not
1921 if (__builtin_expect (l
->l_faked
, 0) != 0
1922 || __builtin_expect (l
->l_removed
, 0) != 0)
1924 if (!_dl_name_match_p (name
, l
))
1928 if (__builtin_expect (l
->l_soname_added
, 1)
1929 || l
->l_info
[DT_SONAME
] == NULL
)
1932 soname
= ((const char *) D_PTR (l
, l_info
[DT_STRTAB
])
1933 + l
->l_info
[DT_SONAME
]->d_un
.d_val
);
1934 if (strcmp (name
, soname
) != 0)
1937 /* We have a match on a new name -- cache it. */
1938 add_name_to_object (l
, soname
);
1939 l
->l_soname_added
= 1;
1942 /* We have a match. */
1946 /* Display information if we are debugging. */
1947 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
1949 _dl_debug_printf ("\nfile=%s [%lu]; needed by %s [%lu]\n", name
, nsid
,
1951 ? loader
->l_name
: rtld_progname
, loader
->l_ns
);
1954 /* Give the auditing libraries a chance to change the name before we
1956 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0)
1957 && (loader
== NULL
|| loader
->l_auditing
== 0))
1959 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1960 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1962 if (afct
->objsearch
!= NULL
)
1964 name
= afct
->objsearch (name
, &loader
->l_audit
[cnt
].cookie
,
1968 /* Do not try anything further. */
1979 if (strchr (name
, '/') == NULL
)
1981 /* Search for NAME in several places. */
1983 size_t namelen
= strlen (name
) + 1;
1985 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
1986 _dl_debug_printf ("find library=%s [%lu]; searching\n", name
, nsid
);
1990 /* When the object has the RUNPATH information we don't use any
1992 if (loader
== NULL
|| loader
->l_info
[DT_RUNPATH
] == NULL
)
1994 /* First try the DT_RPATH of the dependent object that caused NAME
1995 to be loaded. Then that object's dependent, and on up. */
1996 for (l
= loader
; fd
== -1 && l
; l
= l
->l_loader
)
1997 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
1998 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
1999 &realname
, &fb
, loader
, LA_SER_RUNPATH
);
2001 /* If dynamically linked, try the DT_RPATH of the executable
2002 itself. NB: we do this for lookups in any namespace. */
2005 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2006 if (l
&& l
->l_type
!= lt_loaded
&& l
!= loader
2007 && cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2008 fd
= open_path (name
, namelen
, preloaded
, &l
->l_rpath_dirs
,
2009 &realname
, &fb
, loader
?: l
, LA_SER_RUNPATH
);
2013 /* Try the LD_LIBRARY_PATH environment variable. */
2014 if (fd
== -1 && env_path_list
.dirs
!= (void *) -1)
2015 fd
= open_path (name
, namelen
, preloaded
, &env_path_list
,
2017 loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
,
2020 /* Look at the RUNPATH information for this binary. */
2021 if (fd
== -1 && loader
!= NULL
2022 && cache_rpath (loader
, &loader
->l_runpath_dirs
,
2023 DT_RUNPATH
, "RUNPATH"))
2024 fd
= open_path (name
, namelen
, preloaded
,
2025 &loader
->l_runpath_dirs
, &realname
, &fb
, loader
,
2029 && (__builtin_expect (! preloaded
, 1)
2030 || ! INTUSE(__libc_enable_secure
)))
2032 /* Check the list of libraries in the file /etc/ld.so.cache,
2033 for compatibility with Linux's ldconfig program. */
2034 const char *cached
= _dl_load_cache_lookup (name
);
2039 // XXX Correct to unconditionally default to namespace 0?
2040 l
= loader
?: GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2045 /* If the loader has the DF_1_NODEFLIB flag set we must not
2046 use a cache entry from any of these directories. */
2049 /* 'l' is always != NULL for dynamically linked objects. */
2052 __builtin_expect (l
->l_flags_1
& DF_1_NODEFLIB
, 0))
2054 const char *dirp
= system_dirs
;
2055 unsigned int cnt
= 0;
2059 if (memcmp (cached
, dirp
, system_dirs_len
[cnt
]) == 0)
2061 /* The prefix matches. Don't use the entry. */
2066 dirp
+= system_dirs_len
[cnt
] + 1;
2069 while (cnt
< nsystem_dirs_len
);
2074 fd
= open_verify (cached
,
2075 &fb
, loader
?: GL(dl_ns
)[nsid
]._ns_loaded
,
2077 if (__builtin_expect (fd
!= -1, 1))
2079 realname
= local_strdup (cached
);
2080 if (realname
== NULL
)
2090 /* Finally, try the default path. */
2092 && ((l
= loader
?: GL(dl_ns
)[nsid
]._ns_loaded
) == NULL
2093 || __builtin_expect (!(l
->l_flags_1
& DF_1_NODEFLIB
), 1))
2094 && rtld_search_dirs
.dirs
!= (void *) -1)
2095 fd
= open_path (name
, namelen
, preloaded
, &rtld_search_dirs
,
2096 &realname
, &fb
, l
, LA_SER_DEFAULT
);
2098 /* Add another newline when we are tracing the library loading. */
2099 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2100 _dl_debug_printf ("\n");
2104 /* The path may contain dynamic string tokens. */
2106 ? expand_dynamic_string_token (loader
, name
)
2107 : local_strdup (name
));
2108 if (realname
== NULL
)
2112 fd
= open_verify (realname
, &fb
,
2113 loader
?: GL(dl_ns
)[nsid
]._ns_loaded
, 0);
2114 if (__builtin_expect (fd
, 0) == -1)
2122 /* In case the LOADER information has only been provided to get to
2123 the appropriate RUNPATH/RPATH information we do not need it
2125 if (mode
& __RTLD_CALLMAP
)
2128 if (__builtin_expect (fd
, 0) == -1)
2131 && __builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
, 0) == 0)
2133 /* We haven't found an appropriate library. But since we
2134 are only interested in the list of libraries this isn't
2135 so severe. Fake an entry with all the information we
2137 static const Elf_Symndx dummy_bucket
= STN_UNDEF
;
2139 /* Enter the new object in the list of loaded objects. */
2140 if ((name_copy
= local_strdup (name
)) == NULL
2141 || (l
= _dl_new_object (name_copy
, name
, type
, loader
,
2142 mode
, nsid
)) == NULL
)
2143 _dl_signal_error (ENOMEM
, name
, NULL
,
2144 N_("cannot create shared object descriptor"));
2145 /* Signal that this is a faked entry. */
2147 /* Since the descriptor is initialized with zero we do not
2149 l->l_reserved = 0; */
2150 l
->l_buckets
= &dummy_bucket
;
2157 _dl_signal_error (errno
, name
, NULL
,
2158 N_("cannot open shared object file"));
2161 void *stack_end
= __libc_stack_end
;
2162 return _dl_map_object_from_fd (name
, fd
, &fb
, realname
, loader
, type
, mode
,
2169 _dl_rtld_di_serinfo (struct link_map
*loader
, Dl_serinfo
*si
, bool counting
)
2177 unsigned int idx
= 0;
2178 char *allocptr
= (char *) &si
->dls_serpath
[si
->dls_cnt
];
2179 void add_path (const struct r_search_path_struct
*sps
, unsigned int flags
)
2180 # define add_path(sps, flags) add_path(sps, 0) /* XXX */
2182 if (sps
->dirs
!= (void *) -1)
2184 struct r_search_path_elem
**dirs
= sps
->dirs
;
2187 const struct r_search_path_elem
*const r
= *dirs
++;
2191 si
->dls_size
+= r
->dirnamelen
;
2195 Dl_serpath
*const sp
= &si
->dls_serpath
[idx
++];
2196 sp
->dls_name
= allocptr
;
2197 allocptr
= __mempcpy (allocptr
,
2198 r
->dirname
, r
->dirnamelen
- 1);
2200 sp
->dls_flags
= flags
;
2203 while (*dirs
!= NULL
);
2207 /* When the object has the RUNPATH information we don't use any RPATHs. */
2208 if (loader
->l_info
[DT_RUNPATH
] == NULL
)
2210 /* First try the DT_RPATH of the dependent object that caused NAME
2211 to be loaded. Then that object's dependent, and on up. */
2213 struct link_map
*l
= loader
;
2216 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2217 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2222 /* If dynamically linked, try the DT_RPATH of the executable itself. */
2223 if (loader
->l_ns
== LM_ID_BASE
)
2225 l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2226 if (l
!= NULL
&& l
->l_type
!= lt_loaded
&& l
!= loader
)
2227 if (cache_rpath (l
, &l
->l_rpath_dirs
, DT_RPATH
, "RPATH"))
2228 add_path (&l
->l_rpath_dirs
, XXX_RPATH
);
2232 /* Try the LD_LIBRARY_PATH environment variable. */
2233 add_path (&env_path_list
, XXX_ENV
);
2235 /* Look at the RUNPATH information for this binary. */
2236 if (cache_rpath (loader
, &loader
->l_runpath_dirs
, DT_RUNPATH
, "RUNPATH"))
2237 add_path (&loader
->l_runpath_dirs
, XXX_RUNPATH
);
2240 Here is where ld.so.cache gets checked, but we don't have
2241 a way to indicate that in the results for Dl_serinfo. */
2243 /* Finally, try the default path. */
2244 if (!(loader
->l_flags_1
& DF_1_NODEFLIB
))
2245 add_path (&rtld_search_dirs
, XXX_default
);
2248 /* Count the struct size before the string area, which we didn't
2249 know before we completed dls_cnt. */
2250 si
->dls_size
+= (char *) &si
->dls_serpath
[si
->dls_cnt
] - (char *) si
;