1 /* Run time dynamic linker.
2 Copyright (C) 1995-2017 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, see
17 <http://www.gnu.org/licenses/>. */
27 #include <sys/param.h>
32 #include <fpu_control.h>
33 #include <hp-timing.h>
34 #include <libc-lock.h>
35 #include "dynamic-link.h"
36 #include <dl-librecon.h>
37 #include <unsecvars.h>
39 #include <dl-osinfo.h>
40 #include <dl-procinfo.h>
42 #include <stap-probe.h>
43 #include <stackinfo.h>
47 /* Avoid PLT use for our local calls at startup. */
48 extern __typeof (__mempcpy
) __mempcpy attribute_hidden
;
50 /* GCC has mental blocks about _exit. */
51 extern __typeof (_exit
) exit_internal
asm ("_exit") attribute_hidden
;
52 #define _exit exit_internal
54 /* Helper function to handle errors while resolving symbols. */
55 static void print_unresolved (int errcode
, const char *objname
,
56 const char *errsting
);
58 /* Helper function to handle errors when a version is missing. */
59 static void print_missing_version (int errcode
, const char *objname
,
60 const char *errsting
);
62 /* Print the various times we collected. */
63 static void print_statistics (hp_timing_t
*total_timep
);
65 /* Add audit objects. */
66 static void process_dl_audit (char *str
);
68 /* This is a list of all the modes the dynamic loader can be in. */
69 enum mode
{ normal
, list
, verify
, trace
};
71 /* Process all environments variables the dynamic linker must recognize.
72 Since all of them start with `LD_' we are a bit smarter while finding
74 static void process_envvars (enum mode
*modep
);
76 #ifdef DL_ARGV_NOT_RELRO
77 int _dl_argc attribute_hidden
;
78 char **_dl_argv
= NULL
;
79 /* Nonzero if we were run directly. */
80 unsigned int _dl_skip_args attribute_hidden
;
82 int _dl_argc attribute_relro attribute_hidden
;
83 char **_dl_argv attribute_relro
= NULL
;
84 unsigned int _dl_skip_args attribute_relro attribute_hidden
;
86 rtld_hidden_data_def (_dl_argv
)
88 #ifndef THREAD_SET_STACK_GUARD
89 /* Only exported for architectures that don't store the stack guard canary
90 in thread local area. */
91 uintptr_t __stack_chk_guard attribute_relro
;
94 /* Only exported for architectures that don't store the pointer guard
95 value in thread local area. */
96 uintptr_t __pointer_chk_guard_local
97 attribute_relro attribute_hidden
__attribute__ ((nocommon
));
98 #ifndef THREAD_SET_POINTER_GUARD
99 strong_alias (__pointer_chk_guard_local
, __pointer_chk_guard
)
102 /* Length limits for names and paths, to protect the dynamic linker,
103 particularly when __libc_enable_secure is active. */
105 # define SECURE_NAME_LIMIT NAME_MAX
107 # define SECURE_NAME_LIMIT 255
110 # define SECURE_PATH_LIMIT PATH_MAX
112 # define SECURE_PATH_LIMIT 1024
115 /* Check that AT_SECURE=0, or that the passed name does not contain
116 directories and is not overly long. Reject empty names
119 dso_name_valid_for_suid (const char *p
)
121 if (__glibc_unlikely (__libc_enable_secure
))
123 /* Ignore pathnames with directories for AT_SECURE=1
124 programs, and also skip overlong names. */
125 size_t len
= strlen (p
);
126 if (len
>= SECURE_NAME_LIMIT
|| memchr (p
, '/', len
) != NULL
)
132 /* LD_AUDIT variable contents. Must be processed before the
134 const char *audit_list_string
;
136 /* Cyclic list of auditing DSOs. audit_list->next is the first
138 static struct audit_list
141 struct audit_list
*next
;
144 /* Iterator for audit_list_string followed by audit_list. */
145 struct audit_list_iter
147 /* Tail of audit_list_string still needing processing, or NULL. */
148 const char *audit_list_tail
;
150 /* The list element returned in the previous iteration. NULL before
151 the first element. */
152 struct audit_list
*previous
;
154 /* Scratch buffer for returning a name which is part of
155 audit_list_string. */
156 char fname
[SECURE_NAME_LIMIT
];
159 /* Initialize an audit list iterator. */
161 audit_list_iter_init (struct audit_list_iter
*iter
)
163 iter
->audit_list_tail
= audit_list_string
;
164 iter
->previous
= NULL
;
167 /* Iterate through both audit_list_string and audit_list. */
169 audit_list_iter_next (struct audit_list_iter
*iter
)
171 if (iter
->audit_list_tail
!= NULL
)
173 /* First iterate over audit_list_string. */
174 while (*iter
->audit_list_tail
!= '\0')
176 /* Split audit list at colon. */
177 size_t len
= strcspn (iter
->audit_list_tail
, ":");
178 if (len
> 0 && len
< sizeof (iter
->fname
))
180 memcpy (iter
->fname
, iter
->audit_list_tail
, len
);
181 iter
->fname
[len
] = '\0';
184 /* Do not return this name to the caller. */
185 iter
->fname
[0] = '\0';
187 /* Skip over the substring and the following delimiter. */
188 iter
->audit_list_tail
+= len
;
189 if (*iter
->audit_list_tail
== ':')
190 ++iter
->audit_list_tail
;
192 /* If the name is valid, return it. */
193 if (dso_name_valid_for_suid (iter
->fname
))
195 /* Otherwise, wrap around and try the next name. */
197 /* Fall through to the procesing of audit_list. */
200 if (iter
->previous
== NULL
)
202 if (audit_list
== NULL
)
203 /* No pre-parsed audit list. */
205 /* Start of audit list. The first list element is at
206 audit_list->next (cyclic list). */
207 iter
->previous
= audit_list
->next
;
208 return iter
->previous
->name
;
210 if (iter
->previous
== audit_list
)
211 /* Cyclic list wrap-around. */
213 iter
->previous
= iter
->previous
->next
;
214 return iter
->previous
->name
;
217 #ifndef HAVE_INLINED_SYSCALLS
218 /* Set nonzero during loading and initialization of executable and
219 libraries, cleared before the executable's entry point runs. This
220 must not be initialized to nonzero, because the unused dynamic
221 linker loaded in for libc.so's "ld.so.1" dep will provide the
222 definition seen by libc.so's initializer; that value must be zero,
223 and will be since that dynamic linker's _dl_start and dl_main will
225 int _dl_starting_up
= 0;
226 rtld_hidden_def (_dl_starting_up
)
229 /* This is the structure which defines all variables global to ld.so
230 (except those which cannot be added for some reason). */
231 struct rtld_global _rtld_global
=
233 /* Generally the default presumption without further information is an
234 * executable stack but this is not true for all platforms. */
235 ._dl_stack_flags
= DEFAULT_STACK_PERMS
,
236 #ifdef _LIBC_REENTRANT
237 ._dl_load_lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
,
238 ._dl_load_write_lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
,
243 #ifdef _LIBC_REENTRANT
244 [LM_ID_BASE
] = { ._ns_unique_sym_table
245 = { .lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
} }
249 /* If we would use strong_alias here the compiler would see a
250 non-hidden definition. This would undo the effect of the previous
251 declaration. So spell out was strong_alias does plus add the
252 visibility attribute. */
253 extern struct rtld_global _rtld_local
254 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
257 /* This variable is similar to _rtld_local, but all values are
258 read-only after relocation. */
259 struct rtld_global_ro _rtld_global_ro attribute_relro
=
261 /* Get architecture specific initializer. */
262 #include <dl-procinfo.c>
263 #ifdef NEED_DL_SYSINFO
264 ._dl_sysinfo
= DL_SYSINFO_DEFAULT
,
266 ._dl_debug_fd
= STDERR_FILENO
,
267 ._dl_use_load_bias
= -2,
268 ._dl_correct_cache_id
= _DL_CACHE_DEFAULT_ID
,
270 ._dl_hwcap_mask
= HWCAP_IMPORTANT
,
273 ._dl_fpu_control
= _FPU_DEFAULT
,
274 ._dl_pagesize
= EXEC_PAGESIZE
,
275 ._dl_inhibit_cache
= 0,
277 /* Function pointers. */
278 ._dl_debug_printf
= _dl_debug_printf
,
279 ._dl_mcount
= _dl_mcount
,
280 ._dl_lookup_symbol_x
= _dl_lookup_symbol_x
,
281 ._dl_check_caller
= _dl_check_caller
,
282 ._dl_open
= _dl_open
,
283 ._dl_close
= _dl_close
,
284 ._dl_tls_get_addr_soft
= _dl_tls_get_addr_soft
,
285 #ifdef HAVE_DL_DISCOVER_OSVERSION
286 ._dl_discover_osversion
= _dl_discover_osversion
289 /* If we would use strong_alias here the compiler would see a
290 non-hidden definition. This would undo the effect of the previous
291 declaration. So spell out was strong_alias does plus add the
292 visibility attribute. */
293 extern struct rtld_global_ro _rtld_local_ro
294 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
297 static void dl_main (const ElfW(Phdr
) *phdr
, ElfW(Word
) phnum
,
298 ElfW(Addr
) *user_entry
, ElfW(auxv_t
) *auxv
);
300 /* These two variables cannot be moved into .data.rel.ro. */
301 static struct libname_list _dl_rtld_libname
;
302 static struct libname_list _dl_rtld_libname2
;
304 /* Variable for statistics. */
305 #ifndef HP_TIMING_NONAVAIL
306 static hp_timing_t relocate_time
;
307 static hp_timing_t load_time attribute_relro
;
308 static hp_timing_t start_time attribute_relro
;
311 /* Additional definitions needed by TLS initialization. */
312 #ifdef TLS_INIT_HELPER
316 /* Helper function for syscall implementation. */
317 #ifdef DL_SYSINFO_IMPLEMENTATION
318 DL_SYSINFO_IMPLEMENTATION
321 /* Before ld.so is relocated we must not access variables which need
322 relocations. This means variables which are exported. Variables
323 declared as static are fine. If we can mark a variable hidden this
324 is fine, too. The latter is important here. We can avoid setting
325 up a temporary link map for ld.so if we can mark _rtld_global as
327 #ifdef PI_STATIC_AND_HIDDEN
328 # define DONT_USE_BOOTSTRAP_MAP 1
331 #ifdef DONT_USE_BOOTSTRAP_MAP
332 static ElfW(Addr
) _dl_start_final (void *arg
);
334 struct dl_start_final_info
337 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
338 hp_timing_t start_time
;
341 static ElfW(Addr
) _dl_start_final (void *arg
,
342 struct dl_start_final_info
*info
);
345 /* These defined magically in the linker script. */
346 extern char _begin
[] attribute_hidden
;
347 extern char _etext
[] attribute_hidden
;
348 extern char _end
[] attribute_hidden
;
354 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
357 /* This is the second half of _dl_start (below). It can be inlined safely
358 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
359 references. When the tools don't permit us to avoid using a GOT entry
360 for _dl_rtld_global (no attribute_hidden support), we must make sure
361 this function is not inlined (see below). */
363 #ifdef DONT_USE_BOOTSTRAP_MAP
364 static inline ElfW(Addr
) __attribute__ ((always_inline
))
365 _dl_start_final (void *arg
)
367 static ElfW(Addr
) __attribute__ ((noinline
))
368 _dl_start_final (void *arg
, struct dl_start_final_info
*info
)
371 ElfW(Addr
) start_addr
;
373 if (HP_SMALL_TIMING_AVAIL
)
375 /* If it hasn't happen yet record the startup time. */
376 if (! HP_TIMING_INLINE
)
377 HP_TIMING_NOW (start_time
);
378 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
380 start_time
= info
->start_time
;
384 /* Transfer data about ourselves to the permanent link_map structure. */
385 #ifndef DONT_USE_BOOTSTRAP_MAP
386 GL(dl_rtld_map
).l_addr
= info
->l
.l_addr
;
387 GL(dl_rtld_map
).l_ld
= info
->l
.l_ld
;
388 memcpy (GL(dl_rtld_map
).l_info
, info
->l
.l_info
,
389 sizeof GL(dl_rtld_map
).l_info
);
390 GL(dl_rtld_map
).l_mach
= info
->l
.l_mach
;
391 GL(dl_rtld_map
).l_relocated
= 1;
393 _dl_setup_hash (&GL(dl_rtld_map
));
394 GL(dl_rtld_map
).l_real
= &GL(dl_rtld_map
);
395 GL(dl_rtld_map
).l_map_start
= (ElfW(Addr
)) _begin
;
396 GL(dl_rtld_map
).l_map_end
= (ElfW(Addr
)) _end
;
397 GL(dl_rtld_map
).l_text_end
= (ElfW(Addr
)) _etext
;
398 /* Copy the TLS related data if necessary. */
399 #ifndef DONT_USE_BOOTSTRAP_MAP
400 # if NO_TLS_OFFSET != 0
401 GL(dl_rtld_map
).l_tls_offset
= NO_TLS_OFFSET
;
405 HP_TIMING_NOW (GL(dl_cpuclock_offset
));
407 /* Initialize the stack end variable. */
408 __libc_stack_end
= __builtin_frame_address (0);
410 /* Call the OS-dependent function to set up life so we can do things like
411 file access. It will call `dl_main' (below) to do all the real work
412 of the dynamic linker, and then unwind our frame and run the user
413 entry point on the same stack we entered on. */
414 start_addr
= _dl_sysdep_start (arg
, &dl_main
);
416 #ifndef HP_TIMING_NONAVAIL
417 hp_timing_t rtld_total_time
;
418 if (HP_SMALL_TIMING_AVAIL
)
420 hp_timing_t end_time
;
422 /* Get the current time. */
423 HP_TIMING_NOW (end_time
);
425 /* Compute the difference. */
426 HP_TIMING_DIFF (rtld_total_time
, start_time
, end_time
);
430 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_STATISTICS
))
432 #ifndef HP_TIMING_NONAVAIL
433 print_statistics (&rtld_total_time
);
435 print_statistics (NULL
);
442 static ElfW(Addr
) __attribute_used__ internal_function
443 _dl_start (void *arg
)
445 #ifdef DONT_USE_BOOTSTRAP_MAP
446 # define bootstrap_map GL(dl_rtld_map)
448 struct dl_start_final_info info
;
449 # define bootstrap_map info.l
452 /* This #define produces dynamic linking inline functions for
453 bootstrap relocation instead of general-purpose relocation.
454 Since ld.so must not have any undefined symbols the result
455 is trivial: always the map of ld.so itself. */
456 #define RTLD_BOOTSTRAP
457 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
458 #include "dynamic-link.h"
460 if (HP_TIMING_INLINE
&& HP_SMALL_TIMING_AVAIL
)
461 #ifdef DONT_USE_BOOTSTRAP_MAP
462 HP_TIMING_NOW (start_time
);
464 HP_TIMING_NOW (info
.start_time
);
467 /* Partly clean the `bootstrap_map' structure up. Don't use
468 `memset' since it might not be built in or inlined and we cannot
469 make function calls at this point. Use '__builtin_memset' if we
470 know it is available. We do not have to clear the memory if we
471 do not have to use the temporary bootstrap_map. Global variables
472 are initialized to zero by default. */
473 #ifndef DONT_USE_BOOTSTRAP_MAP
474 # ifdef HAVE_BUILTIN_MEMSET
475 __builtin_memset (bootstrap_map
.l_info
, '\0', sizeof (bootstrap_map
.l_info
));
478 cnt
< sizeof (bootstrap_map
.l_info
) / sizeof (bootstrap_map
.l_info
[0]);
480 bootstrap_map
.l_info
[cnt
] = 0;
484 /* Figure out the run-time load address of the dynamic linker itself. */
485 bootstrap_map
.l_addr
= elf_machine_load_address ();
487 /* Read our own dynamic section and fill in the info array. */
488 bootstrap_map
.l_ld
= (void *) bootstrap_map
.l_addr
+ elf_machine_dynamic ();
489 elf_get_dynamic_info (&bootstrap_map
, NULL
);
491 #if NO_TLS_OFFSET != 0
492 bootstrap_map
.l_tls_offset
= NO_TLS_OFFSET
;
495 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
496 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map
.l_info
);
499 if (bootstrap_map
.l_addr
|| ! bootstrap_map
.l_info
[VALIDX(DT_GNU_PRELINKED
)])
501 /* Relocate ourselves so we can do normal function calls and
502 data access using the global offset table. */
504 ELF_DYNAMIC_RELOCATE (&bootstrap_map
, 0, 0, 0);
506 bootstrap_map
.l_relocated
= 1;
508 /* Please note that we don't allow profiling of this object and
509 therefore need not test whether we have to allocate the array
510 for the relocation results (as done in dl-reloc.c). */
512 /* Now life is sane; we can call functions and access global data.
513 Set up to use the operating system facilities, and find out from
514 the operating system's program loader where to find the program
515 header table in core. Put the rest of _dl_start into a separate
516 function, that way the compiler cannot put accesses to the GOT
517 before ELF_DYNAMIC_RELOCATE. */
519 #ifdef DONT_USE_BOOTSTRAP_MAP
520 ElfW(Addr
) entry
= _dl_start_final (arg
);
522 ElfW(Addr
) entry
= _dl_start_final (arg
, &info
);
525 #ifndef ELF_MACHINE_START_ADDRESS
526 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
529 return ELF_MACHINE_START_ADDRESS (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, entry
);
535 /* Now life is peachy; we can do all normal operations.
536 On to the real work. */
538 /* Some helper functions. */
540 /* Arguments to relocate_doit. */
549 /* Argument to map_doit. */
551 struct link_map
*loader
;
553 /* Return value of map_doit. */
554 struct link_map
*map
;
560 struct link_map
*map
;
566 struct link_map
*map
;
570 /* Arguments to version_check_doit. */
571 struct version_check_args
578 relocate_doit (void *a
)
580 struct relocate_args
*args
= (struct relocate_args
*) a
;
582 _dl_relocate_object (args
->l
, args
->l
->l_scope
, args
->reloc_mode
, 0);
588 struct map_args
*args
= (struct map_args
*) a
;
589 int type
= (args
->mode
== __RTLD_OPENEXEC
) ? lt_executable
: lt_library
;
590 args
->map
= _dl_map_object (args
->loader
, args
->str
, type
, 0,
591 args
->mode
, LM_ID_BASE
);
595 dlmopen_doit (void *a
)
597 struct dlmopen_args
*args
= (struct dlmopen_args
*) a
;
598 args
->map
= _dl_open (args
->fname
,
599 (RTLD_LAZY
| __RTLD_DLOPEN
| __RTLD_AUDIT
601 dl_main
, LM_ID_NEWLM
, _dl_argc
, _dl_argv
,
606 lookup_doit (void *a
)
608 struct lookup_args
*args
= (struct lookup_args
*) a
;
609 const ElfW(Sym
) *ref
= NULL
;
611 lookup_t l
= _dl_lookup_symbol_x (args
->name
, args
->map
, &ref
,
612 args
->map
->l_local_scope
, NULL
, 0,
613 DL_LOOKUP_RETURN_NEWEST
, NULL
);
615 args
->result
= DL_SYMBOL_ADDRESS (l
, ref
);
619 version_check_doit (void *a
)
621 struct version_check_args
*args
= (struct version_check_args
*) a
;
622 if (_dl_check_all_versions (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, 1,
623 args
->dotrace
) && args
->doexit
)
624 /* We cannot start the application. Abort now. */
629 static inline struct link_map
*
630 find_needed (const char *name
)
632 struct r_scope_elem
*scope
= &GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
->l_searchlist
;
633 unsigned int n
= scope
->r_nlist
;
636 if (_dl_name_match_p (name
, scope
->r_list
[n
]))
637 return scope
->r_list
[n
];
639 /* Should never happen. */
644 match_version (const char *string
, struct link_map
*map
)
646 const char *strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
649 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
650 if (map
->l_info
[VERDEFTAG
] == NULL
)
651 /* The file has no symbol versioning. */
654 def
= (ElfW(Verdef
) *) ((char *) map
->l_addr
655 + map
->l_info
[VERDEFTAG
]->d_un
.d_ptr
);
658 ElfW(Verdaux
) *aux
= (ElfW(Verdaux
) *) ((char *) def
+ def
->vd_aux
);
660 /* Compare the version strings. */
661 if (strcmp (string
, strtab
+ aux
->vda_name
) == 0)
665 /* If no more definitions we failed to find what we want. */
666 if (def
->vd_next
== 0)
669 /* Next definition. */
670 def
= (ElfW(Verdef
) *) ((char *) def
+ def
->vd_next
);
676 static bool tls_init_tp_called
;
681 /* Number of elements in the static TLS block. */
682 GL(dl_tls_static_nelem
) = GL(dl_tls_max_dtv_idx
);
684 /* Do not do this twice. The audit interface might have required
685 the DTV interfaces to be set up early. */
686 if (GL(dl_initial_dtv
) != NULL
)
689 /* Allocate the array which contains the information about the
690 dtv slots. We allocate a few entries more than needed to
691 avoid the need for reallocation. */
692 size_t nelem
= GL(dl_tls_max_dtv_idx
) + 1 + TLS_SLOTINFO_SURPLUS
;
695 GL(dl_tls_dtv_slotinfo_list
) = (struct dtv_slotinfo_list
*)
696 calloc (sizeof (struct dtv_slotinfo_list
)
697 + nelem
* sizeof (struct dtv_slotinfo
), 1);
698 /* No need to check the return value. If memory allocation failed
699 the program would have been terminated. */
701 struct dtv_slotinfo
*slotinfo
= GL(dl_tls_dtv_slotinfo_list
)->slotinfo
;
702 GL(dl_tls_dtv_slotinfo_list
)->len
= nelem
;
703 GL(dl_tls_dtv_slotinfo_list
)->next
= NULL
;
705 /* Fill in the information from the loaded modules. No namespace
706 but the base one can be filled at this time. */
707 assert (GL(dl_ns
)[LM_ID_BASE
+ 1]._ns_loaded
== NULL
);
709 for (struct link_map
*l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
; l
!= NULL
;
711 if (l
->l_tls_blocksize
!= 0)
713 /* This is a module with TLS data. Store the map reference.
714 The generation counter is zero. */
716 /* slotinfo[i].gen = 0; */
719 assert (i
== GL(dl_tls_max_dtv_idx
));
721 /* Compute the TLS offsets for the various blocks. */
722 _dl_determine_tlsoffset ();
724 /* Construct the static TLS block and the dtv for the initial
725 thread. For some platforms this will include allocating memory
726 for the thread descriptor. The memory for the TLS block will
727 never be freed. It should be allocated accordingly. The dtv
728 array can be changed if dynamic loading requires it. */
729 void *tcbp
= _dl_allocate_tls_storage ();
732 cannot allocate TLS data structures for initial thread");
734 /* Store for detection of the special case by __tls_get_addr
735 so it knows not to pass this dtv to the normal realloc. */
736 GL(dl_initial_dtv
) = GET_DTV (tcbp
);
738 /* And finally install it for the main thread. */
739 const char *lossage
= TLS_INIT_TP (tcbp
);
740 if (__glibc_unlikely (lossage
!= NULL
))
741 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage
);
742 tls_init_tp_called
= true;
748 do_preload (const char *fname
, struct link_map
*main_map
, const char *where
)
751 const char *err_str
= NULL
;
752 struct map_args args
;
756 args
.loader
= main_map
;
757 args
.mode
= __RTLD_SECURE
;
759 unsigned int old_nloaded
= GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
761 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
, &args
);
762 if (__glibc_unlikely (err_str
!= NULL
))
765 ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n",
766 fname
, where
, err_str
);
767 /* No need to call free, this is still before
768 the libc's malloc is used. */
770 else if (GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
!= old_nloaded
)
771 /* It is no duplicate. */
774 /* Nothing loaded. */
778 #if defined SHARED && defined _LIBC_REENTRANT \
779 && defined __rtld_lock_default_lock_recursive
781 rtld_lock_default_lock_recursive (void *lock
)
783 __rtld_lock_default_lock_recursive (lock
);
787 rtld_lock_default_unlock_recursive (void *lock
)
789 __rtld_lock_default_unlock_recursive (lock
);
797 /* Set up the stack checker's canary. */
798 uintptr_t stack_chk_guard
= _dl_setup_stack_chk_guard (_dl_random
);
799 #ifdef THREAD_SET_STACK_GUARD
800 THREAD_SET_STACK_GUARD (stack_chk_guard
);
802 __stack_chk_guard
= stack_chk_guard
;
805 /* Set up the pointer guard as well, if necessary. */
806 uintptr_t pointer_chk_guard
807 = _dl_setup_pointer_guard (_dl_random
, stack_chk_guard
);
808 #ifdef THREAD_SET_POINTER_GUARD
809 THREAD_SET_POINTER_GUARD (pointer_chk_guard
);
811 __pointer_chk_guard_local
= pointer_chk_guard
;
813 /* We do not need the _dl_random value anymore. The less
814 information we leave behind, the better, so clear the
819 #include "setup-vdso.h"
821 /* The library search path. */
822 static const char *library_path attribute_relro
;
823 /* The list preloaded objects. */
824 static const char *preloadlist attribute_relro
;
825 /* Nonzero if information about versions has to be printed. */
826 static int version_info attribute_relro
;
828 /* The LD_PRELOAD environment variable gives list of libraries
829 separated by white space or colons that are loaded before the
830 executable's dependencies and prepended to the global scope list.
831 (If the binary is running setuid all elements containing a '/' are
832 ignored since it is insecure.) Return the number of preloads
835 handle_ld_preload (const char *preloadlist
, struct link_map
*main_map
)
837 unsigned int npreloads
= 0;
838 const char *p
= preloadlist
;
839 char fname
[SECURE_PATH_LIMIT
];
843 /* Split preload list at space/colon. */
844 size_t len
= strcspn (p
, " :");
845 if (len
> 0 && len
< sizeof (fname
))
847 memcpy (fname
, p
, len
);
853 /* Skip over the substring and the following delimiter. */
858 if (dso_name_valid_for_suid (fname
))
859 npreloads
+= do_preload (fname
, main_map
, "LD_PRELOAD");
865 dl_main (const ElfW(Phdr
) *phdr
,
867 ElfW(Addr
) *user_entry
,
870 const ElfW(Phdr
) *ph
;
872 struct link_map
*main_map
;
875 bool has_interp
= false;
877 bool prelinked
= false;
878 bool rtld_is_main
= false;
879 #ifndef HP_TIMING_NONAVAIL
886 GL(dl_init_static_tls
) = &_dl_nothread_init_static_tls
;
888 #if defined SHARED && defined _LIBC_REENTRANT \
889 && defined __rtld_lock_default_lock_recursive
890 GL(dl_rtld_lock_recursive
) = rtld_lock_default_lock_recursive
;
891 GL(dl_rtld_unlock_recursive
) = rtld_lock_default_unlock_recursive
;
894 /* The explicit initialization here is cheaper than processing the reloc
895 in the _rtld_local definition's initializer. */
896 GL(dl_make_stack_executable_hook
) = &_dl_make_stack_executable
;
898 /* Process the environment variable which control the behaviour. */
899 process_envvars (&mode
);
901 #ifndef HAVE_INLINED_SYSCALLS
902 /* Set up a flag which tells we are just starting. */
906 if (*user_entry
== (ElfW(Addr
)) ENTRY_POINT
)
908 /* Ho ho. We are not the program interpreter! We are the program
909 itself! This means someone ran ld.so as a command. Well, that
910 might be convenient to do sometimes. We support it by
911 interpreting the args like this:
913 ld.so PROGRAM ARGS...
915 The first argument is the name of a file containing an ELF
916 executable we will load and run with the following arguments.
917 To simplify life here, PROGRAM is searched for using the
918 normal rules for shared objects, rather than $PATH or anything
919 like that. We just load it and use its entry point; we don't
920 pay attention to its PT_INTERP command (we are the interpreter
921 ourselves). This is an easy way to test a new ld.so before
925 /* Note the place where the dynamic linker actually came from. */
926 GL(dl_rtld_map
).l_name
= rtld_progname
;
929 if (! strcmp (_dl_argv
[1], "--list"))
932 GLRO(dl_lazy
) = -1; /* This means do no dependency analysis. */
938 else if (! strcmp (_dl_argv
[1], "--verify"))
946 else if (! strcmp (_dl_argv
[1], "--inhibit-cache"))
948 GLRO(dl_inhibit_cache
) = 1;
953 else if (! strcmp (_dl_argv
[1], "--library-path")
956 library_path
= _dl_argv
[2];
962 else if (! strcmp (_dl_argv
[1], "--inhibit-rpath")
965 GLRO(dl_inhibit_rpath
) = _dl_argv
[2];
971 else if (! strcmp (_dl_argv
[1], "--audit") && _dl_argc
> 2)
973 process_dl_audit (_dl_argv
[2]);
982 /* If we have no further argument the program was called incorrectly.
983 Grant the user some education. */
986 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
987 You have invoked `ld.so', the helper program for shared library executables.\n\
988 This program usually lives in the file `/lib/ld.so', and special directives\n\
989 in executable files using ELF shared libraries tell the system's program\n\
990 loader to load the helper program from this file. This helper program loads\n\
991 the shared libraries needed by the program executable, prepares the program\n\
992 to run, and runs it. You may invoke this helper program directly from the\n\
993 command line to load and run an ELF executable file; this is like executing\n\
994 that file itself, but always uses this helper program from the file you\n\
995 specified, instead of the helper program file specified in the executable\n\
996 file you run. This is mostly of use for maintainers to test new versions\n\
997 of this helper program; chances are you did not intend to run this program.\n\
999 --list list all dependencies and how they are resolved\n\
1000 --verify verify that given object really is a dynamically linked\n\
1001 object we can handle\n\
1002 --inhibit-cache Do not use " LD_SO_CACHE
"\n\
1003 --library-path PATH use given PATH instead of content of the environment\n\
1004 variable LD_LIBRARY_PATH\n\
1005 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1007 --audit LIST use objects named in LIST as auditors\n");
1013 /* The initialization of _dl_stack_flags done below assumes the
1014 executable's PT_GNU_STACK may have been honored by the kernel, and
1015 so a PT_GNU_STACK with PF_X set means the stack started out with
1016 execute permission. However, this is not really true if the
1017 dynamic linker is the executable the kernel loaded. For this
1018 case, we must reinitialize _dl_stack_flags to match the dynamic
1019 linker itself. If the dynamic linker was built with a
1020 PT_GNU_STACK, then the kernel may have loaded us with a
1021 nonexecutable stack that we will have to make executable when we
1022 load the program below unless it has a PT_GNU_STACK indicating
1023 nonexecutable stack is ok. */
1025 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
1026 if (ph
->p_type
== PT_GNU_STACK
)
1028 GL(dl_stack_flags
) = ph
->p_flags
;
1032 if (__builtin_expect (mode
, normal
) == verify
)
1034 const char *objname
;
1035 const char *err_str
= NULL
;
1036 struct map_args args
;
1039 args
.str
= rtld_progname
;
1041 args
.mode
= __RTLD_OPENEXEC
;
1042 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
,
1044 if (__glibc_unlikely (err_str
!= NULL
))
1045 /* We don't free the returned string, the programs stops
1047 _exit (EXIT_FAILURE
);
1051 HP_TIMING_NOW (start
);
1052 _dl_map_object (NULL
, rtld_progname
, lt_executable
, 0,
1053 __RTLD_OPENEXEC
, LM_ID_BASE
);
1054 HP_TIMING_NOW (stop
);
1056 HP_TIMING_DIFF (load_time
, start
, stop
);
1059 /* Now the map for the main executable is available. */
1060 main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1062 if (__builtin_expect (mode
, normal
) == normal
1063 && GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
1064 && main_map
->l_info
[DT_SONAME
] != NULL
1065 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1066 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
,
1067 (const char *) D_PTR (main_map
, l_info
[DT_STRTAB
])
1068 + main_map
->l_info
[DT_SONAME
]->d_un
.d_val
) == 0)
1069 _dl_fatal_printf ("loader cannot load itself\n");
1071 phdr
= main_map
->l_phdr
;
1072 phnum
= main_map
->l_phnum
;
1073 /* We overwrite here a pointer to a malloc()ed string. But since
1074 the malloc() implementation used at this point is the dummy
1075 implementations which has no real free() function it does not
1076 makes sense to free the old string first. */
1077 main_map
->l_name
= (char *) "";
1078 *user_entry
= main_map
->l_entry
;
1080 #ifdef HAVE_AUX_VECTOR
1081 /* Adjust the on-stack auxiliary vector so that it looks like the
1082 binary was executed directly. */
1083 for (ElfW(auxv_t
) *av
= auxv
; av
->a_type
!= AT_NULL
; av
++)
1087 av
->a_un
.a_val
= (uintptr_t) phdr
;
1090 av
->a_un
.a_val
= phnum
;
1093 av
->a_un
.a_val
= *user_entry
;
1096 av
->a_un
.a_val
= (uintptr_t) _dl_argv
[0];
1103 /* Create a link_map for the executable itself.
1104 This will be what dlopen on "" returns. */
1105 main_map
= _dl_new_object ((char *) "", "", lt_executable
, NULL
,
1106 __RTLD_OPENEXEC
, LM_ID_BASE
);
1107 assert (main_map
!= NULL
);
1108 main_map
->l_phdr
= phdr
;
1109 main_map
->l_phnum
= phnum
;
1110 main_map
->l_entry
= *user_entry
;
1112 /* Even though the link map is not yet fully initialized we can add
1113 it to the map list since there are no possible users running yet. */
1114 _dl_add_to_namespace_list (main_map
, LM_ID_BASE
);
1115 assert (main_map
== GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
);
1117 /* At this point we are in a bit of trouble. We would have to
1118 fill in the values for l_dev and l_ino. But in general we
1119 do not know where the file is. We also do not handle AT_EXECFD
1120 even if it would be passed up.
1122 We leave the values here defined to 0. This is normally no
1123 problem as the program code itself is normally no shared
1124 object and therefore cannot be loaded dynamically. Nothing
1125 prevent the use of dynamic binaries and in these situations
1126 we might get problems. We might not be able to find out
1127 whether the object is already loaded. But since there is no
1128 easy way out and because the dynamic binary must also not
1129 have an SONAME we ignore this program for now. If it becomes
1130 a problem we can force people using SONAMEs. */
1132 /* We delay initializing the path structure until we got the dynamic
1133 information for the program. */
1136 main_map
->l_map_end
= 0;
1137 main_map
->l_text_end
= 0;
1138 /* Perhaps the executable has no PT_LOAD header entries at all. */
1139 main_map
->l_map_start
= ~0;
1140 /* And it was opened directly. */
1141 ++main_map
->l_direct_opencount
;
1143 /* Scan the program header table for the dynamic section. */
1144 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
1148 /* Find out the load address. */
1149 main_map
->l_addr
= (ElfW(Addr
)) phdr
- ph
->p_vaddr
;
1152 /* This tells us where to find the dynamic section,
1153 which tells us everything we need to do. */
1154 main_map
->l_ld
= (void *) main_map
->l_addr
+ ph
->p_vaddr
;
1157 /* This "interpreter segment" was used by the program loader to
1158 find the program interpreter, which is this program itself, the
1159 dynamic linker. We note what name finds us, so that a future
1160 dlopen call or DT_NEEDED entry, for something that wants to link
1161 against the dynamic linker as a shared library, will know that
1162 the shared object is already loaded. */
1163 _dl_rtld_libname
.name
= ((const char *) main_map
->l_addr
1165 /* _dl_rtld_libname.next = NULL; Already zero. */
1166 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1168 /* Ordinarilly, we would get additional names for the loader from
1169 our DT_SONAME. This can't happen if we were actually linked as
1170 a static executable (detect this case when we have no DYNAMIC).
1171 If so, assume the filename component of the interpreter path to
1172 be our SONAME, and add it to our name list. */
1173 if (GL(dl_rtld_map
).l_ld
== NULL
)
1175 const char *p
= NULL
;
1176 const char *cp
= _dl_rtld_libname
.name
;
1178 /* Find the filename part of the path. */
1185 _dl_rtld_libname2
.name
= p
;
1186 /* _dl_rtld_libname2.next = NULL; Already zero. */
1187 _dl_rtld_libname
.next
= &_dl_rtld_libname2
;
1195 ElfW(Addr
) mapstart
;
1196 ElfW(Addr
) allocend
;
1198 /* Remember where the main program starts in memory. */
1199 mapstart
= (main_map
->l_addr
1200 + (ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1)));
1201 if (main_map
->l_map_start
> mapstart
)
1202 main_map
->l_map_start
= mapstart
;
1204 /* Also where it ends. */
1205 allocend
= main_map
->l_addr
+ ph
->p_vaddr
+ ph
->p_memsz
;
1206 if (main_map
->l_map_end
< allocend
)
1207 main_map
->l_map_end
= allocend
;
1208 if ((ph
->p_flags
& PF_X
) && allocend
> main_map
->l_text_end
)
1209 main_map
->l_text_end
= allocend
;
1214 if (ph
->p_memsz
> 0)
1216 /* Note that in the case the dynamic linker we duplicate work
1217 here since we read the PT_TLS entry already in
1218 _dl_start_final. But the result is repeatable so do not
1219 check for this special but unimportant case. */
1220 main_map
->l_tls_blocksize
= ph
->p_memsz
;
1221 main_map
->l_tls_align
= ph
->p_align
;
1222 if (ph
->p_align
== 0)
1223 main_map
->l_tls_firstbyte_offset
= 0;
1225 main_map
->l_tls_firstbyte_offset
= (ph
->p_vaddr
1226 & (ph
->p_align
- 1));
1227 main_map
->l_tls_initimage_size
= ph
->p_filesz
;
1228 main_map
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1230 /* This image gets the ID one. */
1231 GL(dl_tls_max_dtv_idx
) = main_map
->l_tls_modid
= 1;
1236 GL(dl_stack_flags
) = ph
->p_flags
;
1240 main_map
->l_relro_addr
= ph
->p_vaddr
;
1241 main_map
->l_relro_size
= ph
->p_memsz
;
1245 /* Adjust the address of the TLS initialization image in case
1246 the executable is actually an ET_DYN object. */
1247 if (main_map
->l_tls_initimage
!= NULL
)
1248 main_map
->l_tls_initimage
1249 = (char *) main_map
->l_tls_initimage
+ main_map
->l_addr
;
1250 if (! main_map
->l_map_end
)
1251 main_map
->l_map_end
= ~0;
1252 if (! main_map
->l_text_end
)
1253 main_map
->l_text_end
= ~0;
1254 if (! GL(dl_rtld_map
).l_libname
&& GL(dl_rtld_map
).l_name
)
1256 /* We were invoked directly, so the program might not have a
1258 _dl_rtld_libname
.name
= GL(dl_rtld_map
).l_name
;
1259 /* _dl_rtld_libname.next = NULL; Already zero. */
1260 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1263 assert (GL(dl_rtld_map
).l_libname
); /* How else did we get here? */
1265 /* If the current libname is different from the SONAME, add the
1267 if (GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
1268 && strcmp (GL(dl_rtld_map
).l_libname
->name
,
1269 (const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1270 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
) != 0)
1272 static struct libname_list newname
;
1273 newname
.name
= ((char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1274 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_ptr
);
1275 newname
.next
= NULL
;
1276 newname
.dont_free
= 1;
1278 assert (GL(dl_rtld_map
).l_libname
->next
== NULL
);
1279 GL(dl_rtld_map
).l_libname
->next
= &newname
;
1281 /* The ld.so must be relocated since otherwise loading audit modules
1282 will fail since they reuse the very same ld.so. */
1283 assert (GL(dl_rtld_map
).l_relocated
);
1287 /* Extract the contents of the dynamic section for easy access. */
1288 elf_get_dynamic_info (main_map
, NULL
);
1289 /* Set up our cache of pointers into the hash table. */
1290 _dl_setup_hash (main_map
);
1293 if (__builtin_expect (mode
, normal
) == verify
)
1295 /* We were called just to verify that this is a dynamic
1296 executable using us as the program interpreter. Exit with an
1297 error if we were not able to load the binary or no interpreter
1298 is specified (i.e., this is no dynamically linked binary. */
1299 if (main_map
->l_ld
== NULL
)
1302 /* We allow here some platform specific code. */
1303 #ifdef DISTINGUISH_LIB_VERSIONS
1304 DISTINGUISH_LIB_VERSIONS
;
1306 _exit (has_interp
? 0 : 2);
1309 struct link_map
**first_preload
= &GL(dl_rtld_map
).l_next
;
1310 /* Set up the data structures for the system-supplied DSO early,
1311 so they can influence _dl_init_paths. */
1312 setup_vdso (main_map
, &first_preload
);
1314 #ifdef DL_SYSDEP_OSCHECK
1315 DL_SYSDEP_OSCHECK (_dl_fatal_printf
);
1318 /* Initialize the data structures for the search paths for shared
1320 _dl_init_paths (library_path
);
1322 /* Initialize _r_debug. */
1323 struct r_debug
*r
= _dl_debug_initialize (GL(dl_rtld_map
).l_addr
,
1325 r
->r_state
= RT_CONSISTENT
;
1327 /* Put the link_map for ourselves on the chain so it can be found by
1328 name. Note that at this point the global chain of link maps contains
1329 exactly one element, which is pointed to by dl_loaded. */
1330 if (! GL(dl_rtld_map
).l_name
)
1331 /* If not invoked directly, the dynamic linker shared object file was
1332 found by the PT_INTERP name. */
1333 GL(dl_rtld_map
).l_name
= (char *) GL(dl_rtld_map
).l_libname
->name
;
1334 GL(dl_rtld_map
).l_type
= lt_library
;
1335 main_map
->l_next
= &GL(dl_rtld_map
);
1336 GL(dl_rtld_map
).l_prev
= main_map
;
1337 ++GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
1340 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1341 to not using bias for non-prelinked PIEs and libraries
1342 and using it for executables or prelinked PIEs or libraries. */
1343 if (GLRO(dl_use_load_bias
) == (ElfW(Addr
)) -2)
1344 GLRO(dl_use_load_bias
) = main_map
->l_addr
== 0 ? -1 : 0;
1346 /* Set up the program header information for the dynamic linker
1347 itself. It is needed in the dl_iterate_phdr callbacks. */
1348 const ElfW(Ehdr
) *rtld_ehdr
;
1350 /* Starting from binutils-2.23, the linker will define the magic symbol
1351 __ehdr_start to point to our own ELF header if it is visible in a
1352 segment that also includes the phdrs. If that's not available, we use
1353 the old method that assumes the beginning of the file is part of the
1354 lowest-addressed PT_LOAD segment. */
1355 #ifdef HAVE_EHDR_START
1356 extern const ElfW(Ehdr
) __ehdr_start
__attribute__ ((visibility ("hidden")));
1357 rtld_ehdr
= &__ehdr_start
;
1359 rtld_ehdr
= (void *) GL(dl_rtld_map
).l_map_start
;
1361 assert (rtld_ehdr
->e_ehsize
== sizeof *rtld_ehdr
);
1362 assert (rtld_ehdr
->e_phentsize
== sizeof (ElfW(Phdr
)));
1364 const ElfW(Phdr
) *rtld_phdr
= (const void *) rtld_ehdr
+ rtld_ehdr
->e_phoff
;
1366 GL(dl_rtld_map
).l_phdr
= rtld_phdr
;
1367 GL(dl_rtld_map
).l_phnum
= rtld_ehdr
->e_phnum
;
1370 /* PT_GNU_RELRO is usually the last phdr. */
1371 size_t cnt
= rtld_ehdr
->e_phnum
;
1373 if (rtld_phdr
[cnt
].p_type
== PT_GNU_RELRO
)
1375 GL(dl_rtld_map
).l_relro_addr
= rtld_phdr
[cnt
].p_vaddr
;
1376 GL(dl_rtld_map
).l_relro_size
= rtld_phdr
[cnt
].p_memsz
;
1380 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1381 if (GL(dl_rtld_map
).l_tls_blocksize
!= 0)
1382 /* Assign a module ID. Do this before loading any audit modules. */
1383 GL(dl_rtld_map
).l_tls_modid
= _dl_next_tls_modid ();
1385 /* If we have auditing DSOs to load, do it now. */
1386 bool need_security_init
= true;
1387 if (__glibc_unlikely (audit_list
!= NULL
)
1388 || __glibc_unlikely (audit_list_string
!= NULL
))
1390 struct audit_ifaces
*last_audit
= NULL
;
1391 struct audit_list_iter al_iter
;
1392 audit_list_iter_init (&al_iter
);
1394 /* Since we start using the auditing DSOs right away we need to
1395 initialize the data structures now. */
1398 /* Initialize security features. We need to do it this early
1399 since otherwise the constructors of the audit libraries will
1400 use different values (especially the pointer guard) and will
1403 need_security_init
= false;
1407 const char *name
= audit_list_iter_next (&al_iter
);
1411 int tls_idx
= GL(dl_tls_max_dtv_idx
);
1413 /* Now it is time to determine the layout of the static TLS
1414 block and allocate it for the initial thread. Note that we
1415 always allocate the static block, we never defer it even if
1416 no DF_STATIC_TLS bit is set. The reason is that we know
1417 glibc will use the static model. */
1418 struct dlmopen_args dlmargs
;
1419 dlmargs
.fname
= name
;
1422 const char *objname
;
1423 const char *err_str
= NULL
;
1425 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, dlmopen_doit
,
1427 if (__glibc_unlikely (err_str
!= NULL
))
1430 _dl_error_printf ("\
1431 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1434 free ((char *) err_str
);
1438 struct lookup_args largs
;
1439 largs
.name
= "la_version";
1440 largs
.map
= dlmargs
.map
;
1442 /* Check whether the interface version matches. */
1443 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1444 lookup_doit
, &largs
);
1446 unsigned int (*laversion
) (unsigned int);
1449 && (laversion
= largs
.result
) != NULL
1450 && (lav
= laversion (LAV_CURRENT
)) > 0
1451 && lav
<= LAV_CURRENT
)
1453 /* Allocate structure for the callback function pointers.
1454 This call can never fail. */
1457 struct audit_ifaces ifaces
;
1458 #define naudit_ifaces 8
1459 void (*fptr
[naudit_ifaces
]) (void);
1460 } *newp
= malloc (sizeof (*newp
));
1462 /* Names of the auditing interfaces. All in one
1464 static const char audit_iface_names
[] =
1469 #if __ELF_NATIVE_CLASS == 32
1471 #elif __ELF_NATIVE_CLASS == 64
1474 # error "__ELF_NATIVE_CLASS must be defined"
1476 #define STRING(s) __STRING (s)
1477 "la_" STRING (ARCH_LA_PLTENTER
) "\0"
1478 "la_" STRING (ARCH_LA_PLTEXIT
) "\0"
1480 unsigned int cnt
= 0;
1481 const char *cp
= audit_iface_names
;
1485 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1486 lookup_doit
, &largs
);
1488 /* Store the pointer. */
1489 if (err_str
== NULL
&& largs
.result
!= NULL
)
1491 newp
->fptr
[cnt
] = largs
.result
;
1493 /* The dynamic linker link map is statically
1494 allocated, initialize the data now. */
1495 GL(dl_rtld_map
).l_audit
[cnt
].cookie
1496 = (intptr_t) &GL(dl_rtld_map
);
1499 newp
->fptr
[cnt
] = NULL
;
1502 cp
= (char *) rawmemchr (cp
, '\0') + 1;
1504 while (*cp
!= '\0');
1505 assert (cnt
== naudit_ifaces
);
1507 /* Now append the new auditing interface to the list. */
1508 newp
->ifaces
.next
= NULL
;
1509 if (last_audit
== NULL
)
1510 last_audit
= GLRO(dl_audit
) = &newp
->ifaces
;
1512 last_audit
= last_audit
->next
= &newp
->ifaces
;
1515 /* Mark the DSO as being used for auditing. */
1516 dlmargs
.map
->l_auditing
= 1;
1520 /* We cannot use the DSO, it does not have the
1521 appropriate interfaces or it expects something
1524 Lmid_t ns
= dlmargs
.map
->l_ns
;
1526 _dl_close (dlmargs
.map
);
1528 /* Make sure the namespace has been cleared entirely. */
1529 assert (GL(dl_ns
)[ns
]._ns_loaded
== NULL
);
1530 assert (GL(dl_ns
)[ns
]._ns_nloaded
== 0);
1532 GL(dl_tls_max_dtv_idx
) = tls_idx
;
1538 /* If we have any auditing modules, announce that we already
1539 have two objects loaded. */
1540 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
1542 struct link_map
*ls
[2] = { main_map
, &GL(dl_rtld_map
) };
1544 for (unsigned int outer
= 0; outer
< 2; ++outer
)
1546 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1547 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1549 if (afct
->objopen
!= NULL
)
1551 ls
[outer
]->l_audit
[cnt
].bindflags
1552 = afct
->objopen (ls
[outer
], LM_ID_BASE
,
1553 &ls
[outer
]->l_audit
[cnt
].cookie
);
1555 ls
[outer
]->l_audit_any_plt
1556 |= ls
[outer
]->l_audit
[cnt
].bindflags
!= 0;
1565 /* Keep track of the currently loaded modules to count how many
1566 non-audit modules which use TLS are loaded. */
1567 size_t count_modids
= _dl_count_modids ();
1569 /* Set up debugging before the debugger is notified for the first time. */
1570 #ifdef ELF_MACHINE_DEBUG_SETUP
1571 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1572 ELF_MACHINE_DEBUG_SETUP (main_map
, r
);
1573 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map
), r
);
1575 if (main_map
->l_info
[DT_DEBUG
] != NULL
)
1576 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1577 with the run-time address of the r_debug structure */
1578 main_map
->l_info
[DT_DEBUG
]->d_un
.d_ptr
= (ElfW(Addr
)) r
;
1580 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1581 case you run gdb on the dynamic linker directly. */
1582 if (GL(dl_rtld_map
).l_info
[DT_DEBUG
] != NULL
)
1583 GL(dl_rtld_map
).l_info
[DT_DEBUG
]->d_un
.d_ptr
= (ElfW(Addr
)) r
;
1586 /* We start adding objects. */
1587 r
->r_state
= RT_ADD
;
1589 LIBC_PROBE (init_start
, 2, LM_ID_BASE
, r
);
1591 /* Auditing checkpoint: we are ready to signal that the initial map
1592 is being constructed. */
1593 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
1595 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1596 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1598 if (afct
->activity
!= NULL
)
1599 afct
->activity (&main_map
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
1605 /* We have two ways to specify objects to preload: via environment
1606 variable and via the file /etc/ld.so.preload. The latter can also
1607 be used when security is enabled. */
1608 assert (*first_preload
== NULL
);
1609 struct link_map
**preloads
= NULL
;
1610 unsigned int npreloads
= 0;
1612 if (__glibc_unlikely (preloadlist
!= NULL
))
1614 HP_TIMING_NOW (start
);
1615 npreloads
+= handle_ld_preload (preloadlist
, main_map
);
1616 HP_TIMING_NOW (stop
);
1617 HP_TIMING_DIFF (diff
, start
, stop
);
1618 HP_TIMING_ACCUM_NT (load_time
, diff
);
1621 /* There usually is no ld.so.preload file, it should only be used
1622 for emergencies and testing. So the open call etc should usually
1623 fail. Using access() on a non-existing file is faster than using
1624 open(). So we do this first. If it succeeds we do almost twice
1625 the work but this does not matter, since it is not for production
1627 static const char preload_file
[] = "/etc/ld.so.preload";
1628 if (__glibc_unlikely (__access (preload_file
, R_OK
) == 0))
1630 /* Read the contents of the file. */
1631 file
= _dl_sysdep_read_whole_file (preload_file
, &file_size
,
1632 PROT_READ
| PROT_WRITE
);
1633 if (__glibc_unlikely (file
!= MAP_FAILED
))
1635 /* Parse the file. It contains names of libraries to be loaded,
1636 separated by white spaces or `:'. It may also contain
1637 comments introduced by `#'. */
1642 /* Eliminate comments. */
1647 char *comment
= memchr (runp
, '#', rest
);
1648 if (comment
== NULL
)
1651 rest
-= comment
- runp
;
1654 while (--rest
> 0 && *++comment
!= '\n');
1657 /* We have one problematic case: if we have a name at the end of
1658 the file without a trailing terminating characters, we cannot
1659 place the \0. Handle the case separately. */
1660 if (file
[file_size
- 1] != ' ' && file
[file_size
- 1] != '\t'
1661 && file
[file_size
- 1] != '\n' && file
[file_size
- 1] != ':')
1663 problem
= &file
[file_size
];
1664 while (problem
> file
&& problem
[-1] != ' '
1665 && problem
[-1] != '\t'
1666 && problem
[-1] != '\n' && problem
[-1] != ':')
1675 file
[file_size
- 1] = '\0';
1678 HP_TIMING_NOW (start
);
1680 if (file
!= problem
)
1684 while ((p
= strsep (&runp
, ": \t\n")) != NULL
)
1686 npreloads
+= do_preload (p
, main_map
, preload_file
);
1689 if (problem
!= NULL
)
1691 char *p
= strndupa (problem
, file_size
- (problem
- file
));
1693 npreloads
+= do_preload (p
, main_map
, preload_file
);
1696 HP_TIMING_NOW (stop
);
1697 HP_TIMING_DIFF (diff
, start
, stop
);
1698 HP_TIMING_ACCUM_NT (load_time
, diff
);
1700 /* We don't need the file anymore. */
1701 __munmap (file
, file_size
);
1705 if (__glibc_unlikely (*first_preload
!= NULL
))
1707 /* Set up PRELOADS with a vector of the preloaded libraries. */
1708 struct link_map
*l
= *first_preload
;
1709 preloads
= __alloca (npreloads
* sizeof preloads
[0]);
1716 assert (i
== npreloads
);
1719 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1720 specified some libraries to load, these are inserted before the actual
1721 dependencies in the executable's searchlist for symbol resolution. */
1722 HP_TIMING_NOW (start
);
1723 _dl_map_object_deps (main_map
, preloads
, npreloads
, mode
== trace
, 0);
1724 HP_TIMING_NOW (stop
);
1725 HP_TIMING_DIFF (diff
, start
, stop
);
1726 HP_TIMING_ACCUM_NT (load_time
, diff
);
1728 /* Mark all objects as being in the global scope. */
1729 for (i
= main_map
->l_searchlist
.r_nlist
; i
> 0; )
1730 main_map
->l_searchlist
.r_list
[--i
]->l_global
= 1;
1732 /* Remove _dl_rtld_map from the chain. */
1733 GL(dl_rtld_map
).l_prev
->l_next
= GL(dl_rtld_map
).l_next
;
1734 if (GL(dl_rtld_map
).l_next
!= NULL
)
1735 GL(dl_rtld_map
).l_next
->l_prev
= GL(dl_rtld_map
).l_prev
;
1737 for (i
= 1; i
< main_map
->l_searchlist
.r_nlist
; ++i
)
1738 if (main_map
->l_searchlist
.r_list
[i
] == &GL(dl_rtld_map
))
1741 bool rtld_multiple_ref
= false;
1742 if (__glibc_likely (i
< main_map
->l_searchlist
.r_nlist
))
1744 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1745 put it back in the list of visible objects. We insert it into the
1746 chain in symbol search order because gdb uses the chain's order as
1747 its symbol search order. */
1748 rtld_multiple_ref
= true;
1750 GL(dl_rtld_map
).l_prev
= main_map
->l_searchlist
.r_list
[i
- 1];
1751 if (__builtin_expect (mode
, normal
) == normal
)
1753 GL(dl_rtld_map
).l_next
= (i
+ 1 < main_map
->l_searchlist
.r_nlist
1754 ? main_map
->l_searchlist
.r_list
[i
+ 1]
1756 #ifdef NEED_DL_SYSINFO_DSO
1757 if (GLRO(dl_sysinfo_map
) != NULL
1758 && GL(dl_rtld_map
).l_prev
->l_next
== GLRO(dl_sysinfo_map
)
1759 && GL(dl_rtld_map
).l_next
!= GLRO(dl_sysinfo_map
))
1760 GL(dl_rtld_map
).l_prev
= GLRO(dl_sysinfo_map
);
1764 /* In trace mode there might be an invisible object (which we
1765 could not find) after the previous one in the search list.
1766 In this case it doesn't matter much where we put the
1767 interpreter object, so we just initialize the list pointer so
1768 that the assertion below holds. */
1769 GL(dl_rtld_map
).l_next
= GL(dl_rtld_map
).l_prev
->l_next
;
1771 assert (GL(dl_rtld_map
).l_prev
->l_next
== GL(dl_rtld_map
).l_next
);
1772 GL(dl_rtld_map
).l_prev
->l_next
= &GL(dl_rtld_map
);
1773 if (GL(dl_rtld_map
).l_next
!= NULL
)
1775 assert (GL(dl_rtld_map
).l_next
->l_prev
== GL(dl_rtld_map
).l_prev
);
1776 GL(dl_rtld_map
).l_next
->l_prev
= &GL(dl_rtld_map
);
1780 /* Now let us see whether all libraries are available in the
1781 versions we need. */
1783 struct version_check_args args
;
1784 args
.doexit
= mode
== normal
;
1785 args
.dotrace
= mode
== trace
;
1786 _dl_receive_error (print_missing_version
, version_check_doit
, &args
);
1789 /* We do not initialize any of the TLS functionality unless any of the
1790 initial modules uses TLS. This makes dynamic loading of modules with
1791 TLS impossible, but to support it requires either eagerly doing setup
1792 now or lazily doing it later. Doing it now makes us incompatible with
1793 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1794 used. Trying to do it lazily is too hairy to try when there could be
1795 multiple threads (from a non-TLS-using libpthread). */
1796 bool was_tls_init_tp_called
= tls_init_tp_called
;
1800 if (__glibc_likely (need_security_init
))
1801 /* Initialize security features. But only if we have not done it
1805 if (__builtin_expect (mode
, normal
) != normal
)
1807 /* We were run just to list the shared libraries. It is
1808 important that we do this before real relocation, because the
1809 functions we call below for output may no longer work properly
1810 after relocation. */
1813 if (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1815 struct r_scope_elem
*scope
= &main_map
->l_searchlist
;
1817 for (i
= 0; i
< scope
->r_nlist
; i
++)
1819 l
= scope
->r_list
[i
];
1822 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1825 if (_dl_name_match_p (GLRO(dl_trace_prelink
), l
))
1826 GLRO(dl_trace_prelink_map
) = l
;
1827 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1828 DSO_FILENAME (l
->l_libname
->name
),
1829 DSO_FILENAME (l
->l_name
),
1830 (int) sizeof l
->l_map_start
* 2,
1831 (size_t) l
->l_map_start
,
1832 (int) sizeof l
->l_addr
* 2,
1833 (size_t) l
->l_addr
);
1836 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l
->l_tls_modid
,
1837 (int) sizeof l
->l_tls_offset
* 2,
1838 (size_t) l
->l_tls_offset
);
1843 else if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
1845 /* Look through the dependencies of the main executable
1846 and determine which of them is not actually
1848 struct link_map
*l
= main_map
;
1850 /* Relocate the main executable. */
1851 struct relocate_args args
= { .l
= l
,
1852 .reloc_mode
= ((GLRO(dl_lazy
)
1854 | __RTLD_NOIFUNC
) };
1855 _dl_receive_error (print_unresolved
, relocate_doit
, &args
);
1857 /* This loop depends on the dependencies of the executable to
1858 correspond in number and order to the DT_NEEDED entries. */
1859 ElfW(Dyn
) *dyn
= main_map
->l_ld
;
1861 while (dyn
->d_tag
!= DT_NULL
)
1863 if (dyn
->d_tag
== DT_NEEDED
)
1866 #ifdef NEED_DL_SYSINFO_DSO
1867 /* Skip the VDSO since it's not part of the list
1868 of objects we brought in via DT_NEEDED entries. */
1869 if (l
== GLRO(dl_sysinfo_map
))
1876 _dl_printf ("Unused direct dependencies:\n");
1880 _dl_printf ("\t%s\n", l
->l_name
);
1887 _exit (first
!= true);
1889 else if (! main_map
->l_info
[DT_NEEDED
])
1890 _dl_printf ("\tstatically linked\n");
1893 for (l
= main_map
->l_next
; l
; l
= l
->l_next
)
1895 /* The library was not found. */
1896 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1897 else if (strcmp (l
->l_libname
->name
, l
->l_name
) == 0)
1898 _dl_printf ("\t%s (0x%0*Zx)\n", l
->l_libname
->name
,
1899 (int) sizeof l
->l_map_start
* 2,
1900 (size_t) l
->l_map_start
);
1902 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l
->l_libname
->name
,
1903 l
->l_name
, (int) sizeof l
->l_map_start
* 2,
1904 (size_t) l
->l_map_start
);
1907 if (__builtin_expect (mode
, trace
) != trace
)
1908 for (i
= 1; i
< (unsigned int) _dl_argc
; ++i
)
1910 const ElfW(Sym
) *ref
= NULL
;
1911 ElfW(Addr
) loadbase
;
1914 result
= _dl_lookup_symbol_x (_dl_argv
[i
], main_map
,
1915 &ref
, main_map
->l_scope
,
1916 NULL
, ELF_RTYPE_CLASS_PLT
,
1917 DL_LOOKUP_ADD_DEPENDENCY
, NULL
);
1919 loadbase
= LOOKUP_VALUE_ADDRESS (result
);
1921 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1923 (int) sizeof ref
->st_value
* 2,
1924 (size_t) ref
->st_value
,
1925 (int) sizeof loadbase
* 2, (size_t) loadbase
);
1929 /* If LD_WARN is set, warn about undefined symbols. */
1930 if (GLRO(dl_lazy
) >= 0 && GLRO(dl_verbose
))
1932 /* We have to do symbol dependency testing. */
1933 struct relocate_args args
;
1936 args
.reloc_mode
= ((GLRO(dl_lazy
) ? RTLD_LAZY
: 0)
1939 i
= main_map
->l_searchlist
.r_nlist
;
1942 struct link_map
*l
= main_map
->l_initfini
[i
];
1943 if (l
!= &GL(dl_rtld_map
) && ! l
->l_faked
)
1946 _dl_receive_error (print_unresolved
, relocate_doit
,
1951 if ((GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1952 && rtld_multiple_ref
)
1954 /* Mark the link map as not yet relocated again. */
1955 GL(dl_rtld_map
).l_relocated
= 0;
1956 _dl_relocate_object (&GL(dl_rtld_map
),
1957 main_map
->l_scope
, __RTLD_NOIFUNC
, 0);
1960 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
1963 /* Print more information. This means here, print information
1964 about the versions needed. */
1966 struct link_map
*map
;
1968 for (map
= main_map
; map
!= NULL
; map
= map
->l_next
)
1971 ElfW(Dyn
) *dyn
= map
->l_info
[VERNEEDTAG
];
1977 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
1978 ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
1982 _dl_printf ("\n\tVersion information:\n");
1986 _dl_printf ("\t%s:\n", DSO_FILENAME (map
->l_name
));
1991 struct link_map
*needed
;
1993 needed
= find_needed (strtab
+ ent
->vn_file
);
1994 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
1998 const char *fname
= NULL
;
2001 && match_version (strtab
+ aux
->vna_name
,
2003 fname
= needed
->l_name
;
2005 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2006 strtab
+ ent
->vn_file
,
2007 strtab
+ aux
->vna_name
,
2008 aux
->vna_flags
& VER_FLG_WEAK
2010 fname
?: "not found");
2012 if (aux
->vna_next
== 0)
2013 /* No more symbols. */
2017 aux
= (ElfW(Vernaux
) *) ((char *) aux
2021 if (ent
->vn_next
== 0)
2022 /* No more dependencies. */
2025 /* Next dependency. */
2026 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
2035 if (main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]
2036 && ! __builtin_expect (GLRO(dl_profile
) != NULL
, 0)
2037 && ! __builtin_expect (GLRO(dl_dynamic_weak
), 0))
2039 ElfW(Lib
) *liblist
, *liblistend
;
2040 struct link_map
**r_list
, **r_listend
, *l
;
2041 const char *strtab
= (const void *) D_PTR (main_map
, l_info
[DT_STRTAB
]);
2043 assert (main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)] != NULL
);
2044 liblist
= (ElfW(Lib
) *)
2045 main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]->d_un
.d_ptr
;
2046 liblistend
= (ElfW(Lib
) *)
2048 main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)]->d_un
.d_val
);
2049 r_list
= main_map
->l_searchlist
.r_list
;
2050 r_listend
= r_list
+ main_map
->l_searchlist
.r_nlist
;
2052 for (; r_list
< r_listend
&& liblist
< liblistend
; r_list
++)
2059 /* If the library is not mapped where it should, fail. */
2063 /* Next, check if checksum matches. */
2064 if (l
->l_info
[VALIDX(DT_CHECKSUM
)] == NULL
2065 || l
->l_info
[VALIDX(DT_CHECKSUM
)]->d_un
.d_val
2066 != liblist
->l_checksum
)
2069 if (l
->l_info
[VALIDX(DT_GNU_PRELINKED
)] == NULL
2070 || l
->l_info
[VALIDX(DT_GNU_PRELINKED
)]->d_un
.d_val
2071 != liblist
->l_time_stamp
)
2074 if (! _dl_name_match_p (strtab
+ liblist
->l_name
, l
))
2081 if (r_list
== r_listend
&& liblist
== liblistend
)
2084 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
2085 _dl_debug_printf ("\nprelink checking: %s\n",
2086 prelinked
? "ok" : "failed");
2090 /* Now set up the variable which helps the assembler startup code. */
2091 GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
= &main_map
->l_searchlist
;
2093 /* Save the information about the original global scope list since
2094 we need it in the memory handling later. */
2095 GLRO(dl_initial_searchlist
) = *GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
;
2097 /* Remember the last search directory added at startup, now that
2098 malloc will no longer be the one from dl-minimal.c. */
2099 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
2101 /* Print scope information. */
2102 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_SCOPES
))
2104 _dl_debug_printf ("\nInitial object scopes\n");
2106 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2107 _dl_show_scope (l
, 0);
2112 if (main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)] != NULL
)
2114 ElfW(Rela
) *conflict
, *conflictend
;
2115 #ifndef HP_TIMING_NONAVAIL
2120 HP_TIMING_NOW (start
);
2121 assert (main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)] != NULL
);
2122 conflict
= (ElfW(Rela
) *)
2123 main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)]->d_un
.d_ptr
;
2124 conflictend
= (ElfW(Rela
) *)
2126 + main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)]->d_un
.d_val
);
2127 _dl_resolve_conflicts (main_map
, conflict
, conflictend
);
2128 HP_TIMING_NOW (stop
);
2129 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2133 /* Mark all the objects so we know they have been already relocated. */
2134 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2137 if (l
->l_relro_size
)
2138 _dl_protect_relro (l
);
2140 /* Add object to slot information data if necessasy. */
2141 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2142 _dl_add_to_slotinfo (l
);
2147 /* Now we have all the objects loaded. Relocate them all except for
2148 the dynamic linker itself. We do this in reverse order so that copy
2149 relocs of earlier objects overwrite the data written by later
2150 objects. We do not re-relocate the dynamic linker itself in this
2151 loop because that could result in the GOT entries for functions we
2152 call being changed, and that would break us. It is safe to relocate
2153 the dynamic linker out of order because it has no copy relocs (we
2154 know that because it is self-contained). */
2156 int consider_profiling
= GLRO(dl_profile
) != NULL
;
2157 #ifndef HP_TIMING_NONAVAIL
2162 /* If we are profiling we also must do lazy reloaction. */
2163 GLRO(dl_lazy
) |= consider_profiling
;
2165 HP_TIMING_NOW (start
);
2166 unsigned i
= main_map
->l_searchlist
.r_nlist
;
2169 struct link_map
*l
= main_map
->l_initfini
[i
];
2171 /* While we are at it, help the memory handling a bit. We have to
2172 mark some data structures as allocated with the fake malloc()
2173 implementation in ld.so. */
2174 struct libname_list
*lnp
= l
->l_libname
->next
;
2176 while (__builtin_expect (lnp
!= NULL
, 0))
2181 /* Also allocated with the fake malloc(). */
2182 l
->l_free_initfini
= 0;
2184 if (l
!= &GL(dl_rtld_map
))
2185 _dl_relocate_object (l
, l
->l_scope
, GLRO(dl_lazy
) ? RTLD_LAZY
: 0,
2186 consider_profiling
);
2188 /* Add object to slot information data if necessasy. */
2189 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2190 _dl_add_to_slotinfo (l
);
2192 HP_TIMING_NOW (stop
);
2194 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2196 /* Now enable profiling if needed. Like the previous call,
2197 this has to go here because the calls it makes should use the
2198 rtld versions of the functions (particularly calloc()), but it
2199 needs to have _dl_profile_map set up by the relocator. */
2200 if (__glibc_unlikely (GL(dl_profile_map
) != NULL
))
2201 /* We must prepare the profiling. */
2202 _dl_start_profile ();
2205 if ((!was_tls_init_tp_called
&& GL(dl_tls_max_dtv_idx
) > 0)
2206 || count_modids
!= _dl_count_modids ())
2207 ++GL(dl_tls_generation
);
2209 /* Now that we have completed relocation, the initializer data
2210 for the TLS blocks has its final values and we can copy them
2211 into the main thread's TLS area, which we allocated above. */
2212 _dl_allocate_tls_init (tcbp
);
2214 /* And finally install it for the main thread. */
2215 if (! tls_init_tp_called
)
2217 const char *lossage
= TLS_INIT_TP (tcbp
);
2218 if (__glibc_unlikely (lossage
!= NULL
))
2219 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2223 /* Make sure no new search directories have been added. */
2224 assert (GLRO(dl_init_all_dirs
) == GL(dl_all_dirs
));
2226 if (! prelinked
&& rtld_multiple_ref
)
2228 /* There was an explicit ref to the dynamic linker as a shared lib.
2229 Re-relocate ourselves with user-controlled symbol definitions.
2231 We must do this after TLS initialization in case after this
2232 re-relocation, we might call a user-supplied function
2233 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2235 #ifndef HP_TIMING_NONAVAIL
2241 HP_TIMING_NOW (start
);
2242 /* Mark the link map as not yet relocated again. */
2243 GL(dl_rtld_map
).l_relocated
= 0;
2244 _dl_relocate_object (&GL(dl_rtld_map
), main_map
->l_scope
, 0, 0);
2245 HP_TIMING_NOW (stop
);
2246 HP_TIMING_DIFF (add
, start
, stop
);
2247 HP_TIMING_ACCUM_NT (relocate_time
, add
);
2250 /* Do any necessary cleanups for the startup OS interface code.
2251 We do these now so that no calls are made after rtld re-relocation
2252 which might be resolved to different functions than we expect.
2253 We cannot do this before relocating the other objects because
2254 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2255 _dl_sysdep_start_cleanup ();
2258 /* Auditing checkpoint: we have added all objects. */
2259 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
2261 struct link_map
*head
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2262 /* Do not call the functions for any auditing object. */
2263 if (head
->l_auditing
== 0)
2265 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2266 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2268 if (afct
->activity
!= NULL
)
2269 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_CONSISTENT
);
2277 /* Notify the debugger all new objects are now ready to go. We must re-get
2278 the address since by now the variable might be in another object. */
2279 r
= _dl_debug_initialize (0, LM_ID_BASE
);
2280 r
->r_state
= RT_CONSISTENT
;
2282 LIBC_PROBE (init_complete
, 2, LM_ID_BASE
, r
);
2284 #if defined USE_LDCONFIG && !defined MAP_COPY
2285 /* We must munmap() the cache file. */
2286 _dl_unload_cache ();
2289 /* Once we return, _dl_sysdep_start will invoke
2290 the DT_INIT functions and then *USER_ENTRY. */
2293 /* This is a little helper function for resolving symbols while
2294 tracing the binary. */
2296 print_unresolved (int errcode
__attribute__ ((unused
)), const char *objname
,
2297 const char *errstring
)
2299 if (objname
[0] == '\0')
2300 objname
= RTLD_PROGNAME
;
2301 _dl_error_printf ("%s (%s)\n", errstring
, objname
);
2304 /* This is a little helper function for resolving symbols while
2305 tracing the binary. */
2307 print_missing_version (int errcode
__attribute__ ((unused
)),
2308 const char *objname
, const char *errstring
)
2310 _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME
,
2311 objname
, errstring
);
2314 /* Nonzero if any of the debugging options is enabled. */
2315 static int any_debug attribute_relro
;
2317 /* Process the string given as the parameter which explains which debugging
2318 options are enabled. */
2320 process_dl_debug (const char *dl_debug
)
2322 /* When adding new entries make sure that the maximal length of a name
2323 is correctly handled in the LD_DEBUG_HELP code below. */
2327 const char name
[10];
2328 const char helptext
[41];
2329 unsigned short int mask
;
2332 #define LEN_AND_STR(str) sizeof (str) - 1, str
2333 { LEN_AND_STR ("libs"), "display library search paths",
2334 DL_DEBUG_LIBS
| DL_DEBUG_IMPCALLS
},
2335 { LEN_AND_STR ("reloc"), "display relocation processing",
2336 DL_DEBUG_RELOC
| DL_DEBUG_IMPCALLS
},
2337 { LEN_AND_STR ("files"), "display progress for input file",
2338 DL_DEBUG_FILES
| DL_DEBUG_IMPCALLS
},
2339 { LEN_AND_STR ("symbols"), "display symbol table processing",
2340 DL_DEBUG_SYMBOLS
| DL_DEBUG_IMPCALLS
},
2341 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2342 DL_DEBUG_BINDINGS
| DL_DEBUG_IMPCALLS
},
2343 { LEN_AND_STR ("versions"), "display version dependencies",
2344 DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
},
2345 { LEN_AND_STR ("scopes"), "display scope information",
2347 { LEN_AND_STR ("all"), "all previous options combined",
2348 DL_DEBUG_LIBS
| DL_DEBUG_RELOC
| DL_DEBUG_FILES
| DL_DEBUG_SYMBOLS
2349 | DL_DEBUG_BINDINGS
| DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
2350 | DL_DEBUG_SCOPES
},
2351 { LEN_AND_STR ("statistics"), "display relocation statistics",
2352 DL_DEBUG_STATISTICS
},
2353 { LEN_AND_STR ("unused"), "determined unused DSOs",
2355 { LEN_AND_STR ("help"), "display this help message and exit",
2358 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2360 /* Skip separating white spaces and commas. */
2361 while (*dl_debug
!= '\0')
2363 if (*dl_debug
!= ' ' && *dl_debug
!= ',' && *dl_debug
!= ':')
2368 while (dl_debug
[len
] != '\0' && dl_debug
[len
] != ' '
2369 && dl_debug
[len
] != ',' && dl_debug
[len
] != ':')
2372 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2373 if (debopts
[cnt
].len
== len
2374 && memcmp (dl_debug
, debopts
[cnt
].name
, len
) == 0)
2376 GLRO(dl_debug_mask
) |= debopts
[cnt
].mask
;
2381 if (cnt
== ndebopts
)
2383 /* Display a warning and skip everything until next
2385 char *copy
= strndupa (dl_debug
, len
);
2386 _dl_error_printf ("\
2387 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy
);
2397 if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
2399 /* In order to get an accurate picture of whether a particular
2400 DT_NEEDED entry is actually used we have to process both
2401 the PLT and non-PLT relocation entries. */
2405 if (GLRO(dl_debug_mask
) & DL_DEBUG_HELP
)
2410 Valid options for the LD_DEBUG environment variable are:\n\n");
2412 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2413 _dl_printf (" %.*s%s%s\n", debopts
[cnt
].len
, debopts
[cnt
].name
,
2414 " " + debopts
[cnt
].len
- 3,
2415 debopts
[cnt
].helptext
);
2418 To direct the debugging output into a file instead of standard output\n\
2419 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2425 process_dl_audit (char *str
)
2427 /* The parameter is a colon separated list of DSO names. */
2430 while ((p
= (strsep
) (&str
, ":")) != NULL
)
2431 if (dso_name_valid_for_suid (p
))
2433 /* This is using the local malloc, not the system malloc. The
2434 memory can never be freed. */
2435 struct audit_list
*newp
= malloc (sizeof (*newp
));
2438 if (audit_list
== NULL
)
2439 audit_list
= newp
->next
= newp
;
2442 newp
->next
= audit_list
->next
;
2443 audit_list
= audit_list
->next
= newp
;
2448 /* Process all environments variables the dynamic linker must recognize.
2449 Since all of them start with `LD_' we are a bit smarter while finding
2451 extern char **_environ attribute_hidden
;
2455 process_envvars (enum mode
*modep
)
2457 char **runp
= _environ
;
2459 enum mode mode
= normal
;
2460 char *debug_output
= NULL
;
2462 /* This is the default place for profiling data file. */
2463 GLRO(dl_profile_output
)
2464 = &"/var/tmp\0/var/profile"[__libc_enable_secure
? 9 : 0];
2466 while ((envline
= _dl_next_ld_env_entry (&runp
)) != NULL
)
2470 while (envline
[len
] != '\0' && envline
[len
] != '=')
2473 if (envline
[len
] != '=')
2474 /* This is a "LD_" variable at the end of the string without
2475 a '=' character. Ignore it since otherwise we will access
2476 invalid memory below. */
2482 /* Warning level, verbose or not. */
2483 if (memcmp (envline
, "WARN", 4) == 0)
2484 GLRO(dl_verbose
) = envline
[5] != '\0';
2488 /* Debugging of the dynamic linker? */
2489 if (memcmp (envline
, "DEBUG", 5) == 0)
2491 process_dl_debug (&envline
[6]);
2494 if (memcmp (envline
, "AUDIT", 5) == 0)
2495 audit_list_string
= &envline
[6];
2499 /* Print information about versions. */
2500 if (memcmp (envline
, "VERBOSE", 7) == 0)
2502 version_info
= envline
[8] != '\0';
2506 /* List of objects to be preloaded. */
2507 if (memcmp (envline
, "PRELOAD", 7) == 0)
2509 preloadlist
= &envline
[8];
2513 /* Which shared object shall be profiled. */
2514 if (memcmp (envline
, "PROFILE", 7) == 0 && envline
[8] != '\0')
2515 GLRO(dl_profile
) = &envline
[8];
2519 /* Do we bind early? */
2520 if (memcmp (envline
, "BIND_NOW", 8) == 0)
2522 GLRO(dl_lazy
) = envline
[9] == '\0';
2525 if (memcmp (envline
, "BIND_NOT", 8) == 0)
2526 GLRO(dl_bind_not
) = envline
[9] != '\0';
2530 /* Test whether we want to see the content of the auxiliary
2531 array passed up from the kernel. */
2532 if (!__libc_enable_secure
2533 && memcmp (envline
, "SHOW_AUXV", 9) == 0)
2539 /* Mask for the important hardware capabilities. */
2540 if (!__libc_enable_secure
2541 && memcmp (envline
, "HWCAP_MASK", 10) == 0)
2542 GLRO(dl_hwcap_mask
) = _dl_strtoul (&envline
[11], NULL
);
2547 /* Path where the binary is found. */
2548 if (!__libc_enable_secure
2549 && memcmp (envline
, "ORIGIN_PATH", 11) == 0)
2550 GLRO(dl_origin_path
) = &envline
[12];
2554 /* The library search path. */
2555 if (!__libc_enable_secure
2556 && memcmp (envline
, "LIBRARY_PATH", 12) == 0)
2558 library_path
= &envline
[13];
2562 /* Where to place the profiling data file. */
2563 if (memcmp (envline
, "DEBUG_OUTPUT", 12) == 0)
2565 debug_output
= &envline
[13];
2569 if (!__libc_enable_secure
2570 && memcmp (envline
, "DYNAMIC_WEAK", 12) == 0)
2571 GLRO(dl_dynamic_weak
) = 1;
2575 /* We might have some extra environment variable with length 13
2577 #ifdef EXTRA_LD_ENVVARS_13
2580 if (!__libc_enable_secure
2581 && memcmp (envline
, "USE_LOAD_BIAS", 13) == 0)
2583 GLRO(dl_use_load_bias
) = envline
[14] == '1' ? -1 : 0;
2589 /* Where to place the profiling data file. */
2590 if (!__libc_enable_secure
2591 && memcmp (envline
, "PROFILE_OUTPUT", 14) == 0
2592 && envline
[15] != '\0')
2593 GLRO(dl_profile_output
) = &envline
[15];
2597 /* The mode of the dynamic linker can be set. */
2598 if (memcmp (envline
, "TRACE_PRELINKING", 16) == 0)
2601 GLRO(dl_verbose
) = 1;
2602 GLRO(dl_debug_mask
) |= DL_DEBUG_PRELINK
;
2603 GLRO(dl_trace_prelink
) = &envline
[17];
2608 /* The mode of the dynamic linker can be set. */
2609 if (memcmp (envline
, "TRACE_LOADED_OBJECTS", 20) == 0)
2613 /* We might have some extra environment variable to handle. This
2614 is tricky due to the pre-processing of the length of the name
2615 in the switch statement here. The code here assumes that added
2616 environment variables have a different length. */
2617 #ifdef EXTRA_LD_ENVVARS
2623 /* The caller wants this information. */
2626 /* Extra security for SUID binaries. Remove all dangerous environment
2628 if (__builtin_expect (__libc_enable_secure
, 0))
2630 static const char unsecure_envvars
[] =
2631 #ifdef EXTRA_UNSECURE_ENVVARS
2632 EXTRA_UNSECURE_ENVVARS
2637 nextp
= unsecure_envvars
;
2641 /* We could use rawmemchr but this need not be fast. */
2642 nextp
= (char *) (strchr
) (nextp
, '\0') + 1;
2644 while (*nextp
!= '\0');
2646 if (__access ("/etc/suid-debug", F_OK
) != 0)
2649 unsetenv ("MALLOC_CHECK_");
2651 GLRO(dl_debug_mask
) = 0;
2657 /* If we have to run the dynamic linker in debugging mode and the
2658 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2659 messages to this file. */
2660 else if (any_debug
&& debug_output
!= NULL
)
2662 const int flags
= O_WRONLY
| O_APPEND
| O_CREAT
| O_NOFOLLOW
;
2663 size_t name_len
= strlen (debug_output
);
2664 char buf
[name_len
+ 12];
2667 buf
[name_len
+ 11] = '\0';
2668 startp
= _itoa (__getpid (), &buf
[name_len
+ 11], 10, 0);
2670 startp
= memcpy (startp
- name_len
, debug_output
, name_len
);
2672 GLRO(dl_debug_fd
) = __open (startp
, flags
, DEFFILEMODE
);
2673 if (GLRO(dl_debug_fd
) == -1)
2674 /* We use standard output if opening the file failed. */
2675 GLRO(dl_debug_fd
) = STDOUT_FILENO
;
2680 /* Print the various times we collected. */
2682 __attribute ((noinline
))
2683 print_statistics (hp_timing_t
*rtld_total_timep
)
2685 #ifndef HP_TIMING_NONAVAIL
2690 /* Total time rtld used. */
2691 if (HP_SMALL_TIMING_AVAIL
)
2693 HP_TIMING_PRINT (buf
, sizeof (buf
), *rtld_total_timep
);
2694 _dl_debug_printf ("\nruntime linker statistics:\n"
2695 " total startup time in dynamic loader: %s\n", buf
);
2697 /* Print relocation statistics. */
2699 HP_TIMING_PRINT (buf
, sizeof (buf
), relocate_time
);
2700 cp
= _itoa ((1000ULL * relocate_time
) / *rtld_total_timep
,
2701 pbuf
+ sizeof (pbuf
), 10, 0);
2703 switch (pbuf
+ sizeof (pbuf
) - cp
)
2714 _dl_debug_printf ("\
2715 time needed for relocation: %s (%s%%)\n", buf
, pbuf
);
2719 unsigned long int num_relative_relocations
= 0;
2720 for (Lmid_t ns
= 0; ns
< GL(dl_nns
); ++ns
)
2722 if (GL(dl_ns
)[ns
]._ns_loaded
== NULL
)
2725 struct r_scope_elem
*scope
= &GL(dl_ns
)[ns
]._ns_loaded
->l_searchlist
;
2727 for (unsigned int i
= 0; i
< scope
->r_nlist
; i
++)
2729 struct link_map
*l
= scope
->r_list
[i
];
2731 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELCOUNT
)])
2732 num_relative_relocations
2733 += l
->l_info
[VERSYMIDX (DT_RELCOUNT
)]->d_un
.d_val
;
2734 #ifndef ELF_MACHINE_REL_RELATIVE
2735 /* Relative relocations are processed on these architectures if
2736 library is loaded to different address than p_vaddr or
2737 if not prelinked. */
2738 if ((l
->l_addr
!= 0 || !l
->l_info
[VALIDX(DT_GNU_PRELINKED
)])
2739 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2741 /* On e.g. IA-64 or Alpha, relative relocations are processed
2742 only if library is loaded to different address than p_vaddr. */
2743 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2745 num_relative_relocations
2746 += l
->l_info
[VERSYMIDX (DT_RELACOUNT
)]->d_un
.d_val
;
2750 _dl_debug_printf (" number of relocations: %lu\n"
2751 " number of relocations from cache: %lu\n"
2752 " number of relative relocations: %lu\n",
2753 GL(dl_num_relocations
),
2754 GL(dl_num_cache_relocations
),
2755 num_relative_relocations
);
2757 #ifndef HP_TIMING_NONAVAIL
2758 /* Time spend while loading the object and the dependencies. */
2759 if (HP_SMALL_TIMING_AVAIL
)
2762 HP_TIMING_PRINT (buf
, sizeof (buf
), load_time
);
2763 cp
= _itoa ((1000ULL * load_time
) / *rtld_total_timep
,
2764 pbuf
+ sizeof (pbuf
), 10, 0);
2766 switch (pbuf
+ sizeof (pbuf
) - cp
)
2777 _dl_debug_printf ("\
2778 time needed to load objects: %s (%s%%)\n",