1 /* Run time dynamic linker.
2 Copyright (C) 1995-2014 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 <bits/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
;
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
)
103 /* List of auditing DSOs. */
104 static struct audit_list
107 struct audit_list
*next
;
110 #ifndef HAVE_INLINED_SYSCALLS
111 /* Set nonzero during loading and initialization of executable and
112 libraries, cleared before the executable's entry point runs. This
113 must not be initialized to nonzero, because the unused dynamic
114 linker loaded in for libc.so's "ld.so.1" dep will provide the
115 definition seen by libc.so's initializer; that value must be zero,
116 and will be since that dynamic linker's _dl_start and dl_main will
118 int _dl_starting_up
= 0;
119 INTVARDEF(_dl_starting_up
)
122 /* This is the structure which defines all variables global to ld.so
123 (except those which cannot be added for some reason). */
124 struct rtld_global _rtld_global
=
126 /* Generally the default presumption without further information is an
127 * executable stack but this is not true for all platforms. */
128 ._dl_stack_flags
= DEFAULT_STACK_PERMS
,
129 #ifdef _LIBC_REENTRANT
130 ._dl_load_lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
,
131 ._dl_load_write_lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
,
136 #ifdef _LIBC_REENTRANT
137 [LM_ID_BASE
] = { ._ns_unique_sym_table
138 = { .lock
= _RTLD_LOCK_RECURSIVE_INITIALIZER
} }
142 /* If we would use strong_alias here the compiler would see a
143 non-hidden definition. This would undo the effect of the previous
144 declaration. So spell out was strong_alias does plus add the
145 visibility attribute. */
146 extern struct rtld_global _rtld_local
147 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
150 /* This variable is similar to _rtld_local, but all values are
151 read-only after relocation. */
152 struct rtld_global_ro _rtld_global_ro attribute_relro
=
154 /* Get architecture specific initializer. */
155 #include <dl-procinfo.c>
156 #ifdef NEED_DL_SYSINFO
157 ._dl_sysinfo
= DL_SYSINFO_DEFAULT
,
159 ._dl_debug_fd
= STDERR_FILENO
,
160 ._dl_use_load_bias
= -2,
161 ._dl_correct_cache_id
= _DL_CACHE_DEFAULT_ID
,
162 ._dl_hwcap_mask
= HWCAP_IMPORTANT
,
164 ._dl_fpu_control
= _FPU_DEFAULT
,
165 ._dl_pointer_guard
= 1,
166 ._dl_pagesize
= EXEC_PAGESIZE
,
167 ._dl_inhibit_cache
= 0,
169 /* Function pointers. */
170 ._dl_debug_printf
= _dl_debug_printf
,
171 ._dl_catch_error
= _dl_catch_error
,
172 ._dl_signal_error
= _dl_signal_error
,
173 ._dl_mcount
= _dl_mcount_internal
,
174 ._dl_lookup_symbol_x
= _dl_lookup_symbol_x
,
175 ._dl_check_caller
= _dl_check_caller
,
176 ._dl_open
= _dl_open
,
177 ._dl_close
= _dl_close
,
178 ._dl_tls_get_addr_soft
= _dl_tls_get_addr_soft
,
179 #ifdef HAVE_DL_DISCOVER_OSVERSION
180 ._dl_discover_osversion
= _dl_discover_osversion
183 /* If we would use strong_alias here the compiler would see a
184 non-hidden definition. This would undo the effect of the previous
185 declaration. So spell out was strong_alias does plus add the
186 visibility attribute. */
187 extern struct rtld_global_ro _rtld_local_ro
188 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
191 static void dl_main (const ElfW(Phdr
) *phdr
, ElfW(Word
) phnum
,
192 ElfW(Addr
) *user_entry
, ElfW(auxv_t
) *auxv
);
194 /* These two variables cannot be moved into .data.rel.ro. */
195 static struct libname_list _dl_rtld_libname
;
196 static struct libname_list _dl_rtld_libname2
;
198 /* We expect less than a second for relocation. */
199 #ifdef HP_SMALL_TIMING_AVAIL
200 # undef HP_TIMING_AVAIL
201 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
204 /* Variable for statistics. */
205 #ifndef HP_TIMING_NONAVAIL
206 static hp_timing_t relocate_time
;
207 static hp_timing_t load_time attribute_relro
;
208 static hp_timing_t start_time attribute_relro
;
211 /* Additional definitions needed by TLS initialization. */
212 #ifdef TLS_INIT_HELPER
216 /* Helper function for syscall implementation. */
217 #ifdef DL_SYSINFO_IMPLEMENTATION
218 DL_SYSINFO_IMPLEMENTATION
221 /* Before ld.so is relocated we must not access variables which need
222 relocations. This means variables which are exported. Variables
223 declared as static are fine. If we can mark a variable hidden this
224 is fine, too. The latter is important here. We can avoid setting
225 up a temporary link map for ld.so if we can mark _rtld_global as
227 #ifdef PI_STATIC_AND_HIDDEN
228 # define DONT_USE_BOOTSTRAP_MAP 1
231 #ifdef DONT_USE_BOOTSTRAP_MAP
232 static ElfW(Addr
) _dl_start_final (void *arg
);
234 struct dl_start_final_info
237 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
238 hp_timing_t start_time
;
241 static ElfW(Addr
) _dl_start_final (void *arg
,
242 struct dl_start_final_info
*info
);
245 /* These defined magically in the linker script. */
246 extern char _begin
[] attribute_hidden
;
247 extern char _etext
[] attribute_hidden
;
248 extern char _end
[] attribute_hidden
;
254 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
257 /* This is the second half of _dl_start (below). It can be inlined safely
258 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
259 references. When the tools don't permit us to avoid using a GOT entry
260 for _dl_rtld_global (no attribute_hidden support), we must make sure
261 this function is not inlined (see below). */
263 #ifdef DONT_USE_BOOTSTRAP_MAP
264 static inline ElfW(Addr
) __attribute__ ((always_inline
))
265 _dl_start_final (void *arg
)
267 static ElfW(Addr
) __attribute__ ((noinline
))
268 _dl_start_final (void *arg
, struct dl_start_final_info
*info
)
271 ElfW(Addr
) start_addr
;
275 /* If it hasn't happen yet record the startup time. */
276 if (! HP_TIMING_INLINE
)
277 HP_TIMING_NOW (start_time
);
278 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
280 start_time
= info
->start_time
;
283 /* Initialize the timing functions. */
284 HP_TIMING_DIFF_INIT ();
287 /* Transfer data about ourselves to the permanent link_map structure. */
288 #ifndef DONT_USE_BOOTSTRAP_MAP
289 GL(dl_rtld_map
).l_addr
= info
->l
.l_addr
;
290 GL(dl_rtld_map
).l_ld
= info
->l
.l_ld
;
291 memcpy (GL(dl_rtld_map
).l_info
, info
->l
.l_info
,
292 sizeof GL(dl_rtld_map
).l_info
);
293 GL(dl_rtld_map
).l_mach
= info
->l
.l_mach
;
294 GL(dl_rtld_map
).l_relocated
= 1;
296 _dl_setup_hash (&GL(dl_rtld_map
));
297 GL(dl_rtld_map
).l_real
= &GL(dl_rtld_map
);
298 GL(dl_rtld_map
).l_map_start
= (ElfW(Addr
)) _begin
;
299 GL(dl_rtld_map
).l_map_end
= (ElfW(Addr
)) _end
;
300 GL(dl_rtld_map
).l_text_end
= (ElfW(Addr
)) _etext
;
301 /* Copy the TLS related data if necessary. */
302 #ifndef DONT_USE_BOOTSTRAP_MAP
303 # if NO_TLS_OFFSET != 0
304 GL(dl_rtld_map
).l_tls_offset
= NO_TLS_OFFSET
;
309 HP_TIMING_NOW (GL(dl_cpuclock_offset
));
312 /* Initialize the stack end variable. */
313 __libc_stack_end
= __builtin_frame_address (0);
315 /* Call the OS-dependent function to set up life so we can do things like
316 file access. It will call `dl_main' (below) to do all the real work
317 of the dynamic linker, and then unwind our frame and run the user
318 entry point on the same stack we entered on. */
319 start_addr
= _dl_sysdep_start (arg
, &dl_main
);
321 #ifndef HP_TIMING_NONAVAIL
322 hp_timing_t rtld_total_time
;
325 hp_timing_t end_time
;
327 /* Get the current time. */
328 HP_TIMING_NOW (end_time
);
330 /* Compute the difference. */
331 HP_TIMING_DIFF (rtld_total_time
, start_time
, end_time
);
335 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_STATISTICS
))
337 #ifndef HP_TIMING_NONAVAIL
338 print_statistics (&rtld_total_time
);
340 print_statistics (NULL
);
347 static ElfW(Addr
) __attribute_used__ internal_function
348 _dl_start (void *arg
)
350 #ifdef DONT_USE_BOOTSTRAP_MAP
351 # define bootstrap_map GL(dl_rtld_map)
353 struct dl_start_final_info info
;
354 # define bootstrap_map info.l
357 /* This #define produces dynamic linking inline functions for
358 bootstrap relocation instead of general-purpose relocation.
359 Since ld.so must not have any undefined symbols the result
360 is trivial: always the map of ld.so itself. */
361 #define RTLD_BOOTSTRAP
362 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
363 #include "dynamic-link.h"
365 if (HP_TIMING_INLINE
&& HP_TIMING_AVAIL
)
366 #ifdef DONT_USE_BOOTSTRAP_MAP
367 HP_TIMING_NOW (start_time
);
369 HP_TIMING_NOW (info
.start_time
);
372 /* Partly clean the `bootstrap_map' structure up. Don't use
373 `memset' since it might not be built in or inlined and we cannot
374 make function calls at this point. Use '__builtin_memset' if we
375 know it is available. We do not have to clear the memory if we
376 do not have to use the temporary bootstrap_map. Global variables
377 are initialized to zero by default. */
378 #ifndef DONT_USE_BOOTSTRAP_MAP
379 # ifdef HAVE_BUILTIN_MEMSET
380 __builtin_memset (bootstrap_map
.l_info
, '\0', sizeof (bootstrap_map
.l_info
));
383 cnt
< sizeof (bootstrap_map
.l_info
) / sizeof (bootstrap_map
.l_info
[0]);
385 bootstrap_map
.l_info
[cnt
] = 0;
389 /* Figure out the run-time load address of the dynamic linker itself. */
390 bootstrap_map
.l_addr
= elf_machine_load_address ();
392 /* Read our own dynamic section and fill in the info array. */
393 bootstrap_map
.l_ld
= (void *) bootstrap_map
.l_addr
+ elf_machine_dynamic ();
394 elf_get_dynamic_info (&bootstrap_map
, NULL
);
396 #if NO_TLS_OFFSET != 0
397 bootstrap_map
.l_tls_offset
= NO_TLS_OFFSET
;
400 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
401 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map
.l_info
);
404 if (bootstrap_map
.l_addr
|| ! bootstrap_map
.l_info
[VALIDX(DT_GNU_PRELINKED
)])
406 /* Relocate ourselves so we can do normal function calls and
407 data access using the global offset table. */
409 ELF_DYNAMIC_RELOCATE (&bootstrap_map
, 0, 0, 0);
411 bootstrap_map
.l_relocated
= 1;
413 /* Please note that we don't allow profiling of this object and
414 therefore need not test whether we have to allocate the array
415 for the relocation results (as done in dl-reloc.c). */
417 /* Now life is sane; we can call functions and access global data.
418 Set up to use the operating system facilities, and find out from
419 the operating system's program loader where to find the program
420 header table in core. Put the rest of _dl_start into a separate
421 function, that way the compiler cannot put accesses to the GOT
422 before ELF_DYNAMIC_RELOCATE. */
424 #ifdef DONT_USE_BOOTSTRAP_MAP
425 ElfW(Addr
) entry
= _dl_start_final (arg
);
427 ElfW(Addr
) entry
= _dl_start_final (arg
, &info
);
430 #ifndef ELF_MACHINE_START_ADDRESS
431 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
434 return ELF_MACHINE_START_ADDRESS (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, entry
);
440 /* Now life is peachy; we can do all normal operations.
441 On to the real work. */
443 /* Some helper functions. */
445 /* Arguments to relocate_doit. */
454 /* Argument to map_doit. */
456 struct link_map
*loader
;
458 /* Return value of map_doit. */
459 struct link_map
*map
;
465 struct link_map
*map
;
471 struct link_map
*map
;
475 /* Arguments to version_check_doit. */
476 struct version_check_args
483 relocate_doit (void *a
)
485 struct relocate_args
*args
= (struct relocate_args
*) a
;
487 _dl_relocate_object (args
->l
, args
->l
->l_scope
, args
->reloc_mode
, 0);
493 struct map_args
*args
= (struct map_args
*) a
;
494 int type
= (args
->mode
== __RTLD_OPENEXEC
) ? lt_executable
: lt_library
;
495 args
->map
= _dl_map_object (args
->loader
, args
->str
, type
, 0,
496 args
->mode
, LM_ID_BASE
);
500 dlmopen_doit (void *a
)
502 struct dlmopen_args
*args
= (struct dlmopen_args
*) a
;
503 args
->map
= _dl_open (args
->fname
,
504 (RTLD_LAZY
| __RTLD_DLOPEN
| __RTLD_AUDIT
506 dl_main
, LM_ID_NEWLM
, _dl_argc
, INTUSE(_dl_argv
),
511 lookup_doit (void *a
)
513 struct lookup_args
*args
= (struct lookup_args
*) a
;
514 const ElfW(Sym
) *ref
= NULL
;
516 lookup_t l
= _dl_lookup_symbol_x (args
->name
, args
->map
, &ref
,
517 args
->map
->l_local_scope
, NULL
, 0,
518 DL_LOOKUP_RETURN_NEWEST
, NULL
);
520 args
->result
= DL_SYMBOL_ADDRESS (l
, ref
);
524 version_check_doit (void *a
)
526 struct version_check_args
*args
= (struct version_check_args
*) a
;
527 if (_dl_check_all_versions (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, 1,
528 args
->dotrace
) && args
->doexit
)
529 /* We cannot start the application. Abort now. */
534 static inline struct link_map
*
535 find_needed (const char *name
)
537 struct r_scope_elem
*scope
= &GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
->l_searchlist
;
538 unsigned int n
= scope
->r_nlist
;
541 if (_dl_name_match_p (name
, scope
->r_list
[n
]))
542 return scope
->r_list
[n
];
544 /* Should never happen. */
549 match_version (const char *string
, struct link_map
*map
)
551 const char *strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
554 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
555 if (map
->l_info
[VERDEFTAG
] == NULL
)
556 /* The file has no symbol versioning. */
559 def
= (ElfW(Verdef
) *) ((char *) map
->l_addr
560 + map
->l_info
[VERDEFTAG
]->d_un
.d_ptr
);
563 ElfW(Verdaux
) *aux
= (ElfW(Verdaux
) *) ((char *) def
+ def
->vd_aux
);
565 /* Compare the version strings. */
566 if (strcmp (string
, strtab
+ aux
->vda_name
) == 0)
570 /* If no more definitions we failed to find what we want. */
571 if (def
->vd_next
== 0)
574 /* Next definition. */
575 def
= (ElfW(Verdef
) *) ((char *) def
+ def
->vd_next
);
581 static bool tls_init_tp_called
;
586 /* Number of elements in the static TLS block. */
587 GL(dl_tls_static_nelem
) = GL(dl_tls_max_dtv_idx
);
589 /* Do not do this twice. The audit interface might have required
590 the DTV interfaces to be set up early. */
591 if (GL(dl_initial_dtv
) != NULL
)
594 /* Allocate the array which contains the information about the
595 dtv slots. We allocate a few entries more than needed to
596 avoid the need for reallocation. */
597 size_t nelem
= GL(dl_tls_max_dtv_idx
) + 1 + TLS_SLOTINFO_SURPLUS
;
600 GL(dl_tls_dtv_slotinfo_list
) = (struct dtv_slotinfo_list
*)
601 calloc (sizeof (struct dtv_slotinfo_list
)
602 + nelem
* sizeof (struct dtv_slotinfo
), 1);
603 /* No need to check the return value. If memory allocation failed
604 the program would have been terminated. */
606 struct dtv_slotinfo
*slotinfo
= GL(dl_tls_dtv_slotinfo_list
)->slotinfo
;
607 GL(dl_tls_dtv_slotinfo_list
)->len
= nelem
;
608 GL(dl_tls_dtv_slotinfo_list
)->next
= NULL
;
610 /* Fill in the information from the loaded modules. No namespace
611 but the base one can be filled at this time. */
612 assert (GL(dl_ns
)[LM_ID_BASE
+ 1]._ns_loaded
== NULL
);
614 for (struct link_map
*l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
; l
!= NULL
;
616 if (l
->l_tls_blocksize
!= 0)
618 /* This is a module with TLS data. Store the map reference.
619 The generation counter is zero. */
621 /* slotinfo[i].gen = 0; */
624 assert (i
== GL(dl_tls_max_dtv_idx
));
626 /* Compute the TLS offsets for the various blocks. */
627 _dl_determine_tlsoffset ();
629 /* Construct the static TLS block and the dtv for the initial
630 thread. For some platforms this will include allocating memory
631 for the thread descriptor. The memory for the TLS block will
632 never be freed. It should be allocated accordingly. The dtv
633 array can be changed if dynamic loading requires it. */
634 void *tcbp
= _dl_allocate_tls_storage ();
637 cannot allocate TLS data structures for initial thread");
639 /* Store for detection of the special case by __tls_get_addr
640 so it knows not to pass this dtv to the normal realloc. */
641 GL(dl_initial_dtv
) = GET_DTV (tcbp
);
643 /* And finally install it for the main thread. */
644 const char *lossage
= TLS_INIT_TP (tcbp
);
645 if (__glibc_unlikely (lossage
!= NULL
))
646 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage
);
647 tls_init_tp_called
= true;
652 #ifdef _LIBC_REENTRANT
653 /* _dl_error_catch_tsd points to this for the single-threaded case.
654 It's reset by the thread library for multithreaded programs. */
655 void ** __attribute__ ((const))
656 _dl_initial_error_catch_tsd (void)
665 do_preload (char *fname
, struct link_map
*main_map
, const char *where
)
668 const char *err_str
= NULL
;
669 struct map_args args
;
673 args
.loader
= main_map
;
674 args
.mode
= __RTLD_SECURE
;
676 unsigned int old_nloaded
= GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
678 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
, &args
);
679 if (__glibc_unlikely (err_str
!= NULL
))
682 ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n",
683 fname
, where
, err_str
);
684 /* No need to call free, this is still before
685 the libc's malloc is used. */
687 else if (GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
!= old_nloaded
)
688 /* It is no duplicate. */
691 /* Nothing loaded. */
695 #if defined SHARED && defined _LIBC_REENTRANT \
696 && defined __rtld_lock_default_lock_recursive
698 rtld_lock_default_lock_recursive (void *lock
)
700 __rtld_lock_default_lock_recursive (lock
);
704 rtld_lock_default_unlock_recursive (void *lock
)
706 __rtld_lock_default_unlock_recursive (lock
);
714 /* Set up the stack checker's canary. */
715 uintptr_t stack_chk_guard
= _dl_setup_stack_chk_guard (_dl_random
);
716 #ifdef THREAD_SET_STACK_GUARD
717 THREAD_SET_STACK_GUARD (stack_chk_guard
);
719 __stack_chk_guard
= stack_chk_guard
;
722 /* Set up the pointer guard as well, if necessary. */
723 if (GLRO(dl_pointer_guard
))
725 uintptr_t pointer_chk_guard
= _dl_setup_pointer_guard (_dl_random
,
727 #ifdef THREAD_SET_POINTER_GUARD
728 THREAD_SET_POINTER_GUARD (pointer_chk_guard
);
730 __pointer_chk_guard_local
= pointer_chk_guard
;
733 /* We do not need the _dl_random value anymore. The less
734 information we leave behind, the better, so clear the
739 #include "setup-vdso.h"
741 /* The library search path. */
742 static const char *library_path attribute_relro
;
743 /* The list preloaded objects. */
744 static const char *preloadlist attribute_relro
;
745 /* Nonzero if information about versions has to be printed. */
746 static int version_info attribute_relro
;
749 dl_main (const ElfW(Phdr
) *phdr
,
751 ElfW(Addr
) *user_entry
,
754 const ElfW(Phdr
) *ph
;
756 struct link_map
*main_map
;
759 bool has_interp
= false;
761 bool prelinked
= false;
762 bool rtld_is_main
= false;
763 #ifndef HP_TIMING_NONAVAIL
770 #ifdef _LIBC_REENTRANT
771 /* Explicit initialization since the reloc would just be more work. */
772 GL(dl_error_catch_tsd
) = &_dl_initial_error_catch_tsd
;
775 GL(dl_init_static_tls
) = &_dl_nothread_init_static_tls
;
777 #if defined SHARED && defined _LIBC_REENTRANT \
778 && defined __rtld_lock_default_lock_recursive
779 GL(dl_rtld_lock_recursive
) = rtld_lock_default_lock_recursive
;
780 GL(dl_rtld_unlock_recursive
) = rtld_lock_default_unlock_recursive
;
783 /* The explicit initialization here is cheaper than processing the reloc
784 in the _rtld_local definition's initializer. */
785 GL(dl_make_stack_executable_hook
) = &_dl_make_stack_executable
;
787 /* Process the environment variable which control the behaviour. */
788 process_envvars (&mode
);
790 #ifndef HAVE_INLINED_SYSCALLS
791 /* Set up a flag which tells we are just starting. */
792 INTUSE(_dl_starting_up
) = 1;
795 if (*user_entry
== (ElfW(Addr
)) ENTRY_POINT
)
797 /* Ho ho. We are not the program interpreter! We are the program
798 itself! This means someone ran ld.so as a command. Well, that
799 might be convenient to do sometimes. We support it by
800 interpreting the args like this:
802 ld.so PROGRAM ARGS...
804 The first argument is the name of a file containing an ELF
805 executable we will load and run with the following arguments.
806 To simplify life here, PROGRAM is searched for using the
807 normal rules for shared objects, rather than $PATH or anything
808 like that. We just load it and use its entry point; we don't
809 pay attention to its PT_INTERP command (we are the interpreter
810 ourselves). This is an easy way to test a new ld.so before
814 /* Note the place where the dynamic linker actually came from. */
815 GL(dl_rtld_map
).l_name
= rtld_progname
;
818 if (! strcmp (INTUSE(_dl_argv
)[1], "--list"))
821 GLRO(dl_lazy
) = -1; /* This means do no dependency analysis. */
827 else if (! strcmp (INTUSE(_dl_argv
)[1], "--verify"))
835 else if (! strcmp (INTUSE(_dl_argv
)[1], "--inhibit-cache"))
837 GLRO(dl_inhibit_cache
) = 1;
842 else if (! strcmp (INTUSE(_dl_argv
)[1], "--library-path")
845 library_path
= INTUSE(_dl_argv
)[2];
849 INTUSE(_dl_argv
) += 2;
851 else if (! strcmp (INTUSE(_dl_argv
)[1], "--inhibit-rpath")
854 GLRO(dl_inhibit_rpath
) = INTUSE(_dl_argv
)[2];
858 INTUSE(_dl_argv
) += 2;
860 else if (! strcmp (INTUSE(_dl_argv
)[1], "--audit") && _dl_argc
> 2)
862 process_dl_audit (INTUSE(_dl_argv
)[2]);
866 INTUSE(_dl_argv
) += 2;
871 /* If we have no further argument the program was called incorrectly.
872 Grant the user some education. */
875 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
876 You have invoked `ld.so', the helper program for shared library executables.\n\
877 This program usually lives in the file `/lib/ld.so', and special directives\n\
878 in executable files using ELF shared libraries tell the system's program\n\
879 loader to load the helper program from this file. This helper program loads\n\
880 the shared libraries needed by the program executable, prepares the program\n\
881 to run, and runs it. You may invoke this helper program directly from the\n\
882 command line to load and run an ELF executable file; this is like executing\n\
883 that file itself, but always uses this helper program from the file you\n\
884 specified, instead of the helper program file specified in the executable\n\
885 file you run. This is mostly of use for maintainers to test new versions\n\
886 of this helper program; chances are you did not intend to run this program.\n\
888 --list list all dependencies and how they are resolved\n\
889 --verify verify that given object really is a dynamically linked\n\
890 object we can handle\n\
891 --inhibit-cache Do not use " LD_SO_CACHE
"\n\
892 --library-path PATH use given PATH instead of content of the environment\n\
893 variable LD_LIBRARY_PATH\n\
894 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
896 --audit LIST use objects named in LIST as auditors\n");
902 /* The initialization of _dl_stack_flags done below assumes the
903 executable's PT_GNU_STACK may have been honored by the kernel, and
904 so a PT_GNU_STACK with PF_X set means the stack started out with
905 execute permission. However, this is not really true if the
906 dynamic linker is the executable the kernel loaded. For this
907 case, we must reinitialize _dl_stack_flags to match the dynamic
908 linker itself. If the dynamic linker was built with a
909 PT_GNU_STACK, then the kernel may have loaded us with a
910 nonexecutable stack that we will have to make executable when we
911 load the program below unless it has a PT_GNU_STACK indicating
912 nonexecutable stack is ok. */
914 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
915 if (ph
->p_type
== PT_GNU_STACK
)
917 GL(dl_stack_flags
) = ph
->p_flags
;
921 if (__builtin_expect (mode
, normal
) == verify
)
924 const char *err_str
= NULL
;
925 struct map_args args
;
928 args
.str
= rtld_progname
;
930 args
.mode
= __RTLD_OPENEXEC
;
931 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
,
933 if (__glibc_unlikely (err_str
!= NULL
))
934 /* We don't free the returned string, the programs stops
936 _exit (EXIT_FAILURE
);
940 HP_TIMING_NOW (start
);
941 _dl_map_object (NULL
, rtld_progname
, lt_executable
, 0,
942 __RTLD_OPENEXEC
, LM_ID_BASE
);
943 HP_TIMING_NOW (stop
);
945 HP_TIMING_DIFF (load_time
, start
, stop
);
948 /* Now the map for the main executable is available. */
949 main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
951 if (__builtin_expect (mode
, normal
) == normal
952 && GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
953 && main_map
->l_info
[DT_SONAME
] != NULL
954 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
955 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
,
956 (const char *) D_PTR (main_map
, l_info
[DT_STRTAB
])
957 + main_map
->l_info
[DT_SONAME
]->d_un
.d_val
) == 0)
958 _dl_fatal_printf ("loader cannot load itself\n");
960 phdr
= main_map
->l_phdr
;
961 phnum
= main_map
->l_phnum
;
962 /* We overwrite here a pointer to a malloc()ed string. But since
963 the malloc() implementation used at this point is the dummy
964 implementations which has no real free() function it does not
965 makes sense to free the old string first. */
966 main_map
->l_name
= (char *) "";
967 *user_entry
= main_map
->l_entry
;
969 #ifdef HAVE_AUX_VECTOR
970 /* Adjust the on-stack auxiliary vector so that it looks like the
971 binary was executed directly. */
972 for (ElfW(auxv_t
) *av
= auxv
; av
->a_type
!= AT_NULL
; av
++)
976 av
->a_un
.a_val
= (uintptr_t) phdr
;
979 av
->a_un
.a_val
= phnum
;
982 av
->a_un
.a_val
= *user_entry
;
985 av
->a_un
.a_val
= (uintptr_t) _dl_argv
[0];
992 /* Create a link_map for the executable itself.
993 This will be what dlopen on "" returns. */
994 main_map
= _dl_new_object ((char *) "", "", lt_executable
, NULL
,
995 __RTLD_OPENEXEC
, LM_ID_BASE
);
996 assert (main_map
!= NULL
);
997 main_map
->l_phdr
= phdr
;
998 main_map
->l_phnum
= phnum
;
999 main_map
->l_entry
= *user_entry
;
1001 /* Even though the link map is not yet fully initialized we can add
1002 it to the map list since there are no possible users running yet. */
1003 _dl_add_to_namespace_list (main_map
, LM_ID_BASE
);
1004 assert (main_map
== GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
);
1006 /* At this point we are in a bit of trouble. We would have to
1007 fill in the values for l_dev and l_ino. But in general we
1008 do not know where the file is. We also do not handle AT_EXECFD
1009 even if it would be passed up.
1011 We leave the values here defined to 0. This is normally no
1012 problem as the program code itself is normally no shared
1013 object and therefore cannot be loaded dynamically. Nothing
1014 prevent the use of dynamic binaries and in these situations
1015 we might get problems. We might not be able to find out
1016 whether the object is already loaded. But since there is no
1017 easy way out and because the dynamic binary must also not
1018 have an SONAME we ignore this program for now. If it becomes
1019 a problem we can force people using SONAMEs. */
1021 /* We delay initializing the path structure until we got the dynamic
1022 information for the program. */
1025 main_map
->l_map_end
= 0;
1026 main_map
->l_text_end
= 0;
1027 /* Perhaps the executable has no PT_LOAD header entries at all. */
1028 main_map
->l_map_start
= ~0;
1029 /* And it was opened directly. */
1030 ++main_map
->l_direct_opencount
;
1032 /* Scan the program header table for the dynamic section. */
1033 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
1037 /* Find out the load address. */
1038 main_map
->l_addr
= (ElfW(Addr
)) phdr
- ph
->p_vaddr
;
1041 /* This tells us where to find the dynamic section,
1042 which tells us everything we need to do. */
1043 main_map
->l_ld
= (void *) main_map
->l_addr
+ ph
->p_vaddr
;
1046 /* This "interpreter segment" was used by the program loader to
1047 find the program interpreter, which is this program itself, the
1048 dynamic linker. We note what name finds us, so that a future
1049 dlopen call or DT_NEEDED entry, for something that wants to link
1050 against the dynamic linker as a shared library, will know that
1051 the shared object is already loaded. */
1052 _dl_rtld_libname
.name
= ((const char *) main_map
->l_addr
1054 /* _dl_rtld_libname.next = NULL; Already zero. */
1055 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1057 /* Ordinarilly, we would get additional names for the loader from
1058 our DT_SONAME. This can't happen if we were actually linked as
1059 a static executable (detect this case when we have no DYNAMIC).
1060 If so, assume the filename component of the interpreter path to
1061 be our SONAME, and add it to our name list. */
1062 if (GL(dl_rtld_map
).l_ld
== NULL
)
1064 const char *p
= NULL
;
1065 const char *cp
= _dl_rtld_libname
.name
;
1067 /* Find the filename part of the path. */
1074 _dl_rtld_libname2
.name
= p
;
1075 /* _dl_rtld_libname2.next = NULL; Already zero. */
1076 _dl_rtld_libname
.next
= &_dl_rtld_libname2
;
1084 ElfW(Addr
) mapstart
;
1085 ElfW(Addr
) allocend
;
1087 /* Remember where the main program starts in memory. */
1088 mapstart
= (main_map
->l_addr
1089 + (ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1)));
1090 if (main_map
->l_map_start
> mapstart
)
1091 main_map
->l_map_start
= mapstart
;
1093 /* Also where it ends. */
1094 allocend
= main_map
->l_addr
+ ph
->p_vaddr
+ ph
->p_memsz
;
1095 if (main_map
->l_map_end
< allocend
)
1096 main_map
->l_map_end
= allocend
;
1097 if ((ph
->p_flags
& PF_X
) && allocend
> main_map
->l_text_end
)
1098 main_map
->l_text_end
= allocend
;
1103 if (ph
->p_memsz
> 0)
1105 /* Note that in the case the dynamic linker we duplicate work
1106 here since we read the PT_TLS entry already in
1107 _dl_start_final. But the result is repeatable so do not
1108 check for this special but unimportant case. */
1109 main_map
->l_tls_blocksize
= ph
->p_memsz
;
1110 main_map
->l_tls_align
= ph
->p_align
;
1111 if (ph
->p_align
== 0)
1112 main_map
->l_tls_firstbyte_offset
= 0;
1114 main_map
->l_tls_firstbyte_offset
= (ph
->p_vaddr
1115 & (ph
->p_align
- 1));
1116 main_map
->l_tls_initimage_size
= ph
->p_filesz
;
1117 main_map
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1119 /* This image gets the ID one. */
1120 GL(dl_tls_max_dtv_idx
) = main_map
->l_tls_modid
= 1;
1125 GL(dl_stack_flags
) = ph
->p_flags
;
1129 main_map
->l_relro_addr
= ph
->p_vaddr
;
1130 main_map
->l_relro_size
= ph
->p_memsz
;
1134 /* Adjust the address of the TLS initialization image in case
1135 the executable is actually an ET_DYN object. */
1136 if (main_map
->l_tls_initimage
!= NULL
)
1137 main_map
->l_tls_initimage
1138 = (char *) main_map
->l_tls_initimage
+ main_map
->l_addr
;
1139 if (! main_map
->l_map_end
)
1140 main_map
->l_map_end
= ~0;
1141 if (! main_map
->l_text_end
)
1142 main_map
->l_text_end
= ~0;
1143 if (! GL(dl_rtld_map
).l_libname
&& GL(dl_rtld_map
).l_name
)
1145 /* We were invoked directly, so the program might not have a
1147 _dl_rtld_libname
.name
= GL(dl_rtld_map
).l_name
;
1148 /* _dl_rtld_libname.next = NULL; Already zero. */
1149 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1152 assert (GL(dl_rtld_map
).l_libname
); /* How else did we get here? */
1154 /* If the current libname is different from the SONAME, add the
1156 if (GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
1157 && strcmp (GL(dl_rtld_map
).l_libname
->name
,
1158 (const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1159 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
) != 0)
1161 static struct libname_list newname
;
1162 newname
.name
= ((char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1163 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_ptr
);
1164 newname
.next
= NULL
;
1165 newname
.dont_free
= 1;
1167 assert (GL(dl_rtld_map
).l_libname
->next
== NULL
);
1168 GL(dl_rtld_map
).l_libname
->next
= &newname
;
1170 /* The ld.so must be relocated since otherwise loading audit modules
1171 will fail since they reuse the very same ld.so. */
1172 assert (GL(dl_rtld_map
).l_relocated
);
1176 /* Extract the contents of the dynamic section for easy access. */
1177 elf_get_dynamic_info (main_map
, NULL
);
1178 /* Set up our cache of pointers into the hash table. */
1179 _dl_setup_hash (main_map
);
1182 if (__builtin_expect (mode
, normal
) == verify
)
1184 /* We were called just to verify that this is a dynamic
1185 executable using us as the program interpreter. Exit with an
1186 error if we were not able to load the binary or no interpreter
1187 is specified (i.e., this is no dynamically linked binary. */
1188 if (main_map
->l_ld
== NULL
)
1191 /* We allow here some platform specific code. */
1192 #ifdef DISTINGUISH_LIB_VERSIONS
1193 DISTINGUISH_LIB_VERSIONS
;
1195 _exit (has_interp
? 0 : 2);
1198 struct link_map
**first_preload
= &GL(dl_rtld_map
).l_next
;
1199 /* Set up the data structures for the system-supplied DSO early,
1200 so they can influence _dl_init_paths. */
1201 setup_vdso (main_map
, &first_preload
);
1203 #ifdef DL_SYSDEP_OSCHECK
1204 DL_SYSDEP_OSCHECK (_dl_fatal_printf
);
1207 /* Initialize the data structures for the search paths for shared
1209 _dl_init_paths (library_path
);
1211 /* Initialize _r_debug. */
1212 struct r_debug
*r
= _dl_debug_initialize (GL(dl_rtld_map
).l_addr
,
1214 r
->r_state
= RT_CONSISTENT
;
1216 /* Put the link_map for ourselves on the chain so it can be found by
1217 name. Note that at this point the global chain of link maps contains
1218 exactly one element, which is pointed to by dl_loaded. */
1219 if (! GL(dl_rtld_map
).l_name
)
1220 /* If not invoked directly, the dynamic linker shared object file was
1221 found by the PT_INTERP name. */
1222 GL(dl_rtld_map
).l_name
= (char *) GL(dl_rtld_map
).l_libname
->name
;
1223 GL(dl_rtld_map
).l_type
= lt_library
;
1224 main_map
->l_next
= &GL(dl_rtld_map
);
1225 GL(dl_rtld_map
).l_prev
= main_map
;
1226 ++GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
1229 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1230 to not using bias for non-prelinked PIEs and libraries
1231 and using it for executables or prelinked PIEs or libraries. */
1232 if (GLRO(dl_use_load_bias
) == (ElfW(Addr
)) -2)
1233 GLRO(dl_use_load_bias
) = main_map
->l_addr
== 0 ? -1 : 0;
1235 /* Set up the program header information for the dynamic linker
1236 itself. It is needed in the dl_iterate_phdr callbacks. */
1237 const ElfW(Ehdr
) *rtld_ehdr
;
1239 /* Starting from binutils-2.23, the linker will define the magic symbol
1240 __ehdr_start to point to our own ELF header if it is visible in a
1241 segment that also includes the phdrs. If that's not available, we use
1242 the old method that assumes the beginning of the file is part of the
1243 lowest-addressed PT_LOAD segment. */
1244 #ifdef HAVE_EHDR_START
1245 extern const ElfW(Ehdr
) __ehdr_start
__attribute__ ((visibility ("hidden")));
1246 rtld_ehdr
= &__ehdr_start
;
1248 rtld_ehdr
= (void *) GL(dl_rtld_map
).l_map_start
;
1250 assert (rtld_ehdr
->e_ehsize
== sizeof *rtld_ehdr
);
1251 assert (rtld_ehdr
->e_phentsize
== sizeof (ElfW(Phdr
)));
1253 const ElfW(Phdr
) *rtld_phdr
= (const void *) rtld_ehdr
+ rtld_ehdr
->e_phoff
;
1255 GL(dl_rtld_map
).l_phdr
= rtld_phdr
;
1256 GL(dl_rtld_map
).l_phnum
= rtld_ehdr
->e_phnum
;
1259 /* PT_GNU_RELRO is usually the last phdr. */
1260 size_t cnt
= rtld_ehdr
->e_phnum
;
1262 if (rtld_phdr
[cnt
].p_type
== PT_GNU_RELRO
)
1264 GL(dl_rtld_map
).l_relro_addr
= rtld_phdr
[cnt
].p_vaddr
;
1265 GL(dl_rtld_map
).l_relro_size
= rtld_phdr
[cnt
].p_memsz
;
1269 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1270 if (GL(dl_rtld_map
).l_tls_blocksize
!= 0)
1271 /* Assign a module ID. Do this before loading any audit modules. */
1272 GL(dl_rtld_map
).l_tls_modid
= _dl_next_tls_modid ();
1274 /* If we have auditing DSOs to load, do it now. */
1275 if (__glibc_unlikely (audit_list
!= NULL
))
1277 /* Iterate over all entries in the list. The order is important. */
1278 struct audit_ifaces
*last_audit
= NULL
;
1279 struct audit_list
*al
= audit_list
->next
;
1281 /* Since we start using the auditing DSOs right away we need to
1282 initialize the data structures now. */
1285 /* Initialize security features. We need to do it this early
1286 since otherwise the constructors of the audit libraries will
1287 use different values (especially the pointer guard) and will
1293 int tls_idx
= GL(dl_tls_max_dtv_idx
);
1295 /* Now it is time to determine the layout of the static TLS
1296 block and allocate it for the initial thread. Note that we
1297 always allocate the static block, we never defer it even if
1298 no DF_STATIC_TLS bit is set. The reason is that we know
1299 glibc will use the static model. */
1300 struct dlmopen_args dlmargs
;
1301 dlmargs
.fname
= al
->name
;
1304 const char *objname
;
1305 const char *err_str
= NULL
;
1307 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, dlmopen_doit
,
1309 if (__glibc_unlikely (err_str
!= NULL
))
1312 _dl_error_printf ("\
1313 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1316 free ((char *) err_str
);
1320 struct lookup_args largs
;
1321 largs
.name
= "la_version";
1322 largs
.map
= dlmargs
.map
;
1324 /* Check whether the interface version matches. */
1325 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1326 lookup_doit
, &largs
);
1328 unsigned int (*laversion
) (unsigned int);
1331 && (laversion
= largs
.result
) != NULL
1332 && (lav
= laversion (LAV_CURRENT
)) > 0
1333 && lav
<= LAV_CURRENT
)
1335 /* Allocate structure for the callback function pointers.
1336 This call can never fail. */
1339 struct audit_ifaces ifaces
;
1340 #define naudit_ifaces 8
1341 void (*fptr
[naudit_ifaces
]) (void);
1342 } *newp
= malloc (sizeof (*newp
));
1344 /* Names of the auditing interfaces. All in one
1346 static const char audit_iface_names
[] =
1351 #if __ELF_NATIVE_CLASS == 32
1353 #elif __ELF_NATIVE_CLASS == 64
1356 # error "__ELF_NATIVE_CLASS must be defined"
1358 #define STRING(s) __STRING (s)
1359 "la_" STRING (ARCH_LA_PLTENTER
) "\0"
1360 "la_" STRING (ARCH_LA_PLTEXIT
) "\0"
1362 unsigned int cnt
= 0;
1363 const char *cp
= audit_iface_names
;
1367 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1368 lookup_doit
, &largs
);
1370 /* Store the pointer. */
1371 if (err_str
== NULL
&& largs
.result
!= NULL
)
1373 newp
->fptr
[cnt
] = largs
.result
;
1375 /* The dynamic linker link map is statically
1376 allocated, initialize the data now. */
1377 GL(dl_rtld_map
).l_audit
[cnt
].cookie
1378 = (intptr_t) &GL(dl_rtld_map
);
1381 newp
->fptr
[cnt
] = NULL
;
1384 cp
= (char *) rawmemchr (cp
, '\0') + 1;
1386 while (*cp
!= '\0');
1387 assert (cnt
== naudit_ifaces
);
1389 /* Now append the new auditing interface to the list. */
1390 newp
->ifaces
.next
= NULL
;
1391 if (last_audit
== NULL
)
1392 last_audit
= GLRO(dl_audit
) = &newp
->ifaces
;
1394 last_audit
= last_audit
->next
= &newp
->ifaces
;
1397 /* Mark the DSO as being used for auditing. */
1398 dlmargs
.map
->l_auditing
= 1;
1402 /* We cannot use the DSO, it does not have the
1403 appropriate interfaces or it expects something
1406 Lmid_t ns
= dlmargs
.map
->l_ns
;
1408 _dl_close (dlmargs
.map
);
1410 /* Make sure the namespace has been cleared entirely. */
1411 assert (GL(dl_ns
)[ns
]._ns_loaded
== NULL
);
1412 assert (GL(dl_ns
)[ns
]._ns_nloaded
== 0);
1414 GL(dl_tls_max_dtv_idx
) = tls_idx
;
1421 while (al
!= audit_list
->next
);
1423 /* If we have any auditing modules, announce that we already
1424 have two objects loaded. */
1425 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
1427 struct link_map
*ls
[2] = { main_map
, &GL(dl_rtld_map
) };
1429 for (unsigned int outer
= 0; outer
< 2; ++outer
)
1431 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1432 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1434 if (afct
->objopen
!= NULL
)
1436 ls
[outer
]->l_audit
[cnt
].bindflags
1437 = afct
->objopen (ls
[outer
], LM_ID_BASE
,
1438 &ls
[outer
]->l_audit
[cnt
].cookie
);
1440 ls
[outer
]->l_audit_any_plt
1441 |= ls
[outer
]->l_audit
[cnt
].bindflags
!= 0;
1450 /* Keep track of the currently loaded modules to count how many
1451 non-audit modules which use TLS are loaded. */
1452 size_t count_modids
= _dl_count_modids ();
1454 /* Set up debugging before the debugger is notified for the first time. */
1455 #ifdef ELF_MACHINE_DEBUG_SETUP
1456 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1457 ELF_MACHINE_DEBUG_SETUP (main_map
, r
);
1458 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map
), r
);
1460 if (main_map
->l_info
[DT_DEBUG
] != NULL
)
1461 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1462 with the run-time address of the r_debug structure */
1463 main_map
->l_info
[DT_DEBUG
]->d_un
.d_ptr
= (ElfW(Addr
)) r
;
1465 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1466 case you run gdb on the dynamic linker directly. */
1467 if (GL(dl_rtld_map
).l_info
[DT_DEBUG
] != NULL
)
1468 GL(dl_rtld_map
).l_info
[DT_DEBUG
]->d_un
.d_ptr
= (ElfW(Addr
)) r
;
1471 /* We start adding objects. */
1472 r
->r_state
= RT_ADD
;
1474 LIBC_PROBE (init_start
, 2, LM_ID_BASE
, r
);
1476 /* Auditing checkpoint: we are ready to signal that the initial map
1477 is being constructed. */
1478 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
1480 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1481 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1483 if (afct
->activity
!= NULL
)
1484 afct
->activity (&main_map
->l_audit
[cnt
].cookie
, LA_ACT_ADD
);
1490 /* We have two ways to specify objects to preload: via environment
1491 variable and via the file /etc/ld.so.preload. The latter can also
1492 be used when security is enabled. */
1493 assert (*first_preload
== NULL
);
1494 struct link_map
**preloads
= NULL
;
1495 unsigned int npreloads
= 0;
1497 if (__glibc_unlikely (preloadlist
!= NULL
))
1499 /* The LD_PRELOAD environment variable gives list of libraries
1500 separated by white space or colons that are loaded before the
1501 executable's dependencies and prepended to the global scope
1502 list. If the binary is running setuid all elements
1503 containing a '/' are ignored since it is insecure. */
1504 char *list
= strdupa (preloadlist
);
1507 HP_TIMING_NOW (start
);
1509 /* Prevent optimizing strsep. Speed is not important here. */
1510 while ((p
= (strsep
) (&list
, " :")) != NULL
)
1512 && (__builtin_expect (! INTUSE(__libc_enable_secure
), 1)
1513 || strchr (p
, '/') == NULL
))
1514 npreloads
+= do_preload (p
, main_map
, "LD_PRELOAD");
1516 HP_TIMING_NOW (stop
);
1517 HP_TIMING_DIFF (diff
, start
, stop
);
1518 HP_TIMING_ACCUM_NT (load_time
, diff
);
1521 /* There usually is no ld.so.preload file, it should only be used
1522 for emergencies and testing. So the open call etc should usually
1523 fail. Using access() on a non-existing file is faster than using
1524 open(). So we do this first. If it succeeds we do almost twice
1525 the work but this does not matter, since it is not for production
1527 static const char preload_file
[] = "/etc/ld.so.preload";
1528 if (__glibc_unlikely (__access (preload_file
, R_OK
) == 0))
1530 /* Read the contents of the file. */
1531 file
= _dl_sysdep_read_whole_file (preload_file
, &file_size
,
1532 PROT_READ
| PROT_WRITE
);
1533 if (__glibc_unlikely (file
!= MAP_FAILED
))
1535 /* Parse the file. It contains names of libraries to be loaded,
1536 separated by white spaces or `:'. It may also contain
1537 comments introduced by `#'. */
1542 /* Eliminate comments. */
1547 char *comment
= memchr (runp
, '#', rest
);
1548 if (comment
== NULL
)
1551 rest
-= comment
- runp
;
1554 while (--rest
> 0 && *++comment
!= '\n');
1557 /* We have one problematic case: if we have a name at the end of
1558 the file without a trailing terminating characters, we cannot
1559 place the \0. Handle the case separately. */
1560 if (file
[file_size
- 1] != ' ' && file
[file_size
- 1] != '\t'
1561 && file
[file_size
- 1] != '\n' && file
[file_size
- 1] != ':')
1563 problem
= &file
[file_size
];
1564 while (problem
> file
&& problem
[-1] != ' '
1565 && problem
[-1] != '\t'
1566 && problem
[-1] != '\n' && problem
[-1] != ':')
1575 file
[file_size
- 1] = '\0';
1578 HP_TIMING_NOW (start
);
1580 if (file
!= problem
)
1584 while ((p
= strsep (&runp
, ": \t\n")) != NULL
)
1586 npreloads
+= do_preload (p
, main_map
, preload_file
);
1589 if (problem
!= NULL
)
1591 char *p
= strndupa (problem
, file_size
- (problem
- file
));
1593 npreloads
+= do_preload (p
, main_map
, preload_file
);
1596 HP_TIMING_NOW (stop
);
1597 HP_TIMING_DIFF (diff
, start
, stop
);
1598 HP_TIMING_ACCUM_NT (load_time
, diff
);
1600 /* We don't need the file anymore. */
1601 __munmap (file
, file_size
);
1605 if (__glibc_unlikely (*first_preload
!= NULL
))
1607 /* Set up PRELOADS with a vector of the preloaded libraries. */
1608 struct link_map
*l
= *first_preload
;
1609 preloads
= __alloca (npreloads
* sizeof preloads
[0]);
1616 assert (i
== npreloads
);
1619 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1620 specified some libraries to load, these are inserted before the actual
1621 dependencies in the executable's searchlist for symbol resolution. */
1622 HP_TIMING_NOW (start
);
1623 _dl_map_object_deps (main_map
, preloads
, npreloads
, mode
== trace
, 0);
1624 HP_TIMING_NOW (stop
);
1625 HP_TIMING_DIFF (diff
, start
, stop
);
1626 HP_TIMING_ACCUM_NT (load_time
, diff
);
1628 /* Mark all objects as being in the global scope. */
1629 for (i
= main_map
->l_searchlist
.r_nlist
; i
> 0; )
1630 main_map
->l_searchlist
.r_list
[--i
]->l_global
= 1;
1632 /* Remove _dl_rtld_map from the chain. */
1633 GL(dl_rtld_map
).l_prev
->l_next
= GL(dl_rtld_map
).l_next
;
1634 if (GL(dl_rtld_map
).l_next
!= NULL
)
1635 GL(dl_rtld_map
).l_next
->l_prev
= GL(dl_rtld_map
).l_prev
;
1637 for (i
= 1; i
< main_map
->l_searchlist
.r_nlist
; ++i
)
1638 if (main_map
->l_searchlist
.r_list
[i
] == &GL(dl_rtld_map
))
1641 bool rtld_multiple_ref
= false;
1642 if (__glibc_likely (i
< main_map
->l_searchlist
.r_nlist
))
1644 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1645 put it back in the list of visible objects. We insert it into the
1646 chain in symbol search order because gdb uses the chain's order as
1647 its symbol search order. */
1648 rtld_multiple_ref
= true;
1650 GL(dl_rtld_map
).l_prev
= main_map
->l_searchlist
.r_list
[i
- 1];
1651 if (__builtin_expect (mode
, normal
) == normal
)
1653 GL(dl_rtld_map
).l_next
= (i
+ 1 < main_map
->l_searchlist
.r_nlist
1654 ? main_map
->l_searchlist
.r_list
[i
+ 1]
1656 #ifdef NEED_DL_SYSINFO_DSO
1657 if (GLRO(dl_sysinfo_map
) != NULL
1658 && GL(dl_rtld_map
).l_prev
->l_next
== GLRO(dl_sysinfo_map
)
1659 && GL(dl_rtld_map
).l_next
!= GLRO(dl_sysinfo_map
))
1660 GL(dl_rtld_map
).l_prev
= GLRO(dl_sysinfo_map
);
1664 /* In trace mode there might be an invisible object (which we
1665 could not find) after the previous one in the search list.
1666 In this case it doesn't matter much where we put the
1667 interpreter object, so we just initialize the list pointer so
1668 that the assertion below holds. */
1669 GL(dl_rtld_map
).l_next
= GL(dl_rtld_map
).l_prev
->l_next
;
1671 assert (GL(dl_rtld_map
).l_prev
->l_next
== GL(dl_rtld_map
).l_next
);
1672 GL(dl_rtld_map
).l_prev
->l_next
= &GL(dl_rtld_map
);
1673 if (GL(dl_rtld_map
).l_next
!= NULL
)
1675 assert (GL(dl_rtld_map
).l_next
->l_prev
== GL(dl_rtld_map
).l_prev
);
1676 GL(dl_rtld_map
).l_next
->l_prev
= &GL(dl_rtld_map
);
1680 /* Now let us see whether all libraries are available in the
1681 versions we need. */
1683 struct version_check_args args
;
1684 args
.doexit
= mode
== normal
;
1685 args
.dotrace
= mode
== trace
;
1686 _dl_receive_error (print_missing_version
, version_check_doit
, &args
);
1689 /* We do not initialize any of the TLS functionality unless any of the
1690 initial modules uses TLS. This makes dynamic loading of modules with
1691 TLS impossible, but to support it requires either eagerly doing setup
1692 now or lazily doing it later. Doing it now makes us incompatible with
1693 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1694 used. Trying to do it lazily is too hairy to try when there could be
1695 multiple threads (from a non-TLS-using libpthread). */
1696 bool was_tls_init_tp_called
= tls_init_tp_called
;
1700 if (__glibc_likely (audit_list
== NULL
))
1701 /* Initialize security features. But only if we have not done it
1705 if (__builtin_expect (mode
, normal
) != normal
)
1707 /* We were run just to list the shared libraries. It is
1708 important that we do this before real relocation, because the
1709 functions we call below for output may no longer work properly
1710 after relocation. */
1713 if (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1715 struct r_scope_elem
*scope
= &main_map
->l_searchlist
;
1717 for (i
= 0; i
< scope
->r_nlist
; i
++)
1719 l
= scope
->r_list
[i
];
1722 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1725 if (_dl_name_match_p (GLRO(dl_trace_prelink
), l
))
1726 GLRO(dl_trace_prelink_map
) = l
;
1727 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1728 DSO_FILENAME (l
->l_libname
->name
),
1729 DSO_FILENAME (l
->l_name
),
1730 (int) sizeof l
->l_map_start
* 2,
1731 (size_t) l
->l_map_start
,
1732 (int) sizeof l
->l_addr
* 2,
1733 (size_t) l
->l_addr
);
1736 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l
->l_tls_modid
,
1737 (int) sizeof l
->l_tls_offset
* 2,
1738 (size_t) l
->l_tls_offset
);
1743 else if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
1745 /* Look through the dependencies of the main executable
1746 and determine which of them is not actually
1748 struct link_map
*l
= main_map
;
1750 /* Relocate the main executable. */
1751 struct relocate_args args
= { .l
= l
,
1752 .reloc_mode
= ((GLRO(dl_lazy
)
1754 | __RTLD_NOIFUNC
) };
1755 _dl_receive_error (print_unresolved
, relocate_doit
, &args
);
1757 /* This loop depends on the dependencies of the executable to
1758 correspond in number and order to the DT_NEEDED entries. */
1759 ElfW(Dyn
) *dyn
= main_map
->l_ld
;
1761 while (dyn
->d_tag
!= DT_NULL
)
1763 if (dyn
->d_tag
== DT_NEEDED
)
1766 #ifdef NEED_DL_SYSINFO_DSO
1767 /* Skip the VDSO since it's not part of the list
1768 of objects we brought in via DT_NEEDED entries. */
1769 if (l
== GLRO(dl_sysinfo_map
))
1776 _dl_printf ("Unused direct dependencies:\n");
1780 _dl_printf ("\t%s\n", l
->l_name
);
1787 _exit (first
!= true);
1789 else if (! main_map
->l_info
[DT_NEEDED
])
1790 _dl_printf ("\tstatically linked\n");
1793 for (l
= main_map
->l_next
; l
; l
= l
->l_next
)
1795 /* The library was not found. */
1796 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1797 else if (strcmp (l
->l_libname
->name
, l
->l_name
) == 0)
1798 _dl_printf ("\t%s (0x%0*Zx)\n", l
->l_libname
->name
,
1799 (int) sizeof l
->l_map_start
* 2,
1800 (size_t) l
->l_map_start
);
1802 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l
->l_libname
->name
,
1803 l
->l_name
, (int) sizeof l
->l_map_start
* 2,
1804 (size_t) l
->l_map_start
);
1807 if (__builtin_expect (mode
, trace
) != trace
)
1808 for (i
= 1; i
< (unsigned int) _dl_argc
; ++i
)
1810 const ElfW(Sym
) *ref
= NULL
;
1811 ElfW(Addr
) loadbase
;
1814 result
= _dl_lookup_symbol_x (INTUSE(_dl_argv
)[i
], main_map
,
1815 &ref
, main_map
->l_scope
,
1816 NULL
, ELF_RTYPE_CLASS_PLT
,
1817 DL_LOOKUP_ADD_DEPENDENCY
, NULL
);
1819 loadbase
= LOOKUP_VALUE_ADDRESS (result
);
1821 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1822 INTUSE(_dl_argv
)[i
],
1823 (int) sizeof ref
->st_value
* 2,
1824 (size_t) ref
->st_value
,
1825 (int) sizeof loadbase
* 2, (size_t) loadbase
);
1829 /* If LD_WARN is set, warn about undefined symbols. */
1830 if (GLRO(dl_lazy
) >= 0 && GLRO(dl_verbose
))
1832 /* We have to do symbol dependency testing. */
1833 struct relocate_args args
;
1836 args
.reloc_mode
= ((GLRO(dl_lazy
) ? RTLD_LAZY
: 0)
1839 i
= main_map
->l_searchlist
.r_nlist
;
1842 struct link_map
*l
= main_map
->l_initfini
[i
];
1843 if (l
!= &GL(dl_rtld_map
) && ! l
->l_faked
)
1846 _dl_receive_error (print_unresolved
, relocate_doit
,
1851 if ((GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1852 && rtld_multiple_ref
)
1854 /* Mark the link map as not yet relocated again. */
1855 GL(dl_rtld_map
).l_relocated
= 0;
1856 _dl_relocate_object (&GL(dl_rtld_map
),
1857 main_map
->l_scope
, __RTLD_NOIFUNC
, 0);
1860 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
1863 /* Print more information. This means here, print information
1864 about the versions needed. */
1866 struct link_map
*map
;
1868 for (map
= main_map
; map
!= NULL
; map
= map
->l_next
)
1871 ElfW(Dyn
) *dyn
= map
->l_info
[VERNEEDTAG
];
1877 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
1878 ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
1882 _dl_printf ("\n\tVersion information:\n");
1886 _dl_printf ("\t%s:\n", DSO_FILENAME (map
->l_name
));
1891 struct link_map
*needed
;
1893 needed
= find_needed (strtab
+ ent
->vn_file
);
1894 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
1898 const char *fname
= NULL
;
1901 && match_version (strtab
+ aux
->vna_name
,
1903 fname
= needed
->l_name
;
1905 _dl_printf ("\t\t%s (%s) %s=> %s\n",
1906 strtab
+ ent
->vn_file
,
1907 strtab
+ aux
->vna_name
,
1908 aux
->vna_flags
& VER_FLG_WEAK
1910 fname
?: "not found");
1912 if (aux
->vna_next
== 0)
1913 /* No more symbols. */
1917 aux
= (ElfW(Vernaux
) *) ((char *) aux
1921 if (ent
->vn_next
== 0)
1922 /* No more dependencies. */
1925 /* Next dependency. */
1926 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
1935 if (main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]
1936 && ! __builtin_expect (GLRO(dl_profile
) != NULL
, 0)
1937 && ! __builtin_expect (GLRO(dl_dynamic_weak
), 0))
1939 ElfW(Lib
) *liblist
, *liblistend
;
1940 struct link_map
**r_list
, **r_listend
, *l
;
1941 const char *strtab
= (const void *) D_PTR (main_map
, l_info
[DT_STRTAB
]);
1943 assert (main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)] != NULL
);
1944 liblist
= (ElfW(Lib
) *)
1945 main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]->d_un
.d_ptr
;
1946 liblistend
= (ElfW(Lib
) *)
1948 main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)]->d_un
.d_val
);
1949 r_list
= main_map
->l_searchlist
.r_list
;
1950 r_listend
= r_list
+ main_map
->l_searchlist
.r_nlist
;
1952 for (; r_list
< r_listend
&& liblist
< liblistend
; r_list
++)
1959 /* If the library is not mapped where it should, fail. */
1963 /* Next, check if checksum matches. */
1964 if (l
->l_info
[VALIDX(DT_CHECKSUM
)] == NULL
1965 || l
->l_info
[VALIDX(DT_CHECKSUM
)]->d_un
.d_val
1966 != liblist
->l_checksum
)
1969 if (l
->l_info
[VALIDX(DT_GNU_PRELINKED
)] == NULL
1970 || l
->l_info
[VALIDX(DT_GNU_PRELINKED
)]->d_un
.d_val
1971 != liblist
->l_time_stamp
)
1974 if (! _dl_name_match_p (strtab
+ liblist
->l_name
, l
))
1981 if (r_list
== r_listend
&& liblist
== liblistend
)
1984 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
))
1985 _dl_debug_printf ("\nprelink checking: %s\n",
1986 prelinked
? "ok" : "failed");
1990 /* Now set up the variable which helps the assembler startup code. */
1991 GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
= &main_map
->l_searchlist
;
1993 /* Save the information about the original global scope list since
1994 we need it in the memory handling later. */
1995 GLRO(dl_initial_searchlist
) = *GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
;
1997 /* Remember the last search directory added at startup, now that
1998 malloc will no longer be the one from dl-minimal.c. */
1999 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
2001 /* Print scope information. */
2002 if (__glibc_unlikely (GLRO(dl_debug_mask
) & DL_DEBUG_SCOPES
))
2004 _dl_debug_printf ("\nInitial object scopes\n");
2006 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2007 _dl_show_scope (l
, 0);
2012 if (main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)] != NULL
)
2014 ElfW(Rela
) *conflict
, *conflictend
;
2015 #ifndef HP_TIMING_NONAVAIL
2020 HP_TIMING_NOW (start
);
2021 assert (main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)] != NULL
);
2022 conflict
= (ElfW(Rela
) *)
2023 main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)]->d_un
.d_ptr
;
2024 conflictend
= (ElfW(Rela
) *)
2026 + main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)]->d_un
.d_val
);
2027 _dl_resolve_conflicts (main_map
, conflict
, conflictend
);
2028 HP_TIMING_NOW (stop
);
2029 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2033 /* Mark all the objects so we know they have been already relocated. */
2034 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2037 if (l
->l_relro_size
)
2038 _dl_protect_relro (l
);
2040 /* Add object to slot information data if necessasy. */
2041 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2042 _dl_add_to_slotinfo (l
);
2047 /* Now we have all the objects loaded. Relocate them all except for
2048 the dynamic linker itself. We do this in reverse order so that copy
2049 relocs of earlier objects overwrite the data written by later
2050 objects. We do not re-relocate the dynamic linker itself in this
2051 loop because that could result in the GOT entries for functions we
2052 call being changed, and that would break us. It is safe to relocate
2053 the dynamic linker out of order because it has no copy relocs (we
2054 know that because it is self-contained). */
2056 int consider_profiling
= GLRO(dl_profile
) != NULL
;
2057 #ifndef HP_TIMING_NONAVAIL
2062 /* If we are profiling we also must do lazy reloaction. */
2063 GLRO(dl_lazy
) |= consider_profiling
;
2065 HP_TIMING_NOW (start
);
2066 unsigned i
= main_map
->l_searchlist
.r_nlist
;
2069 struct link_map
*l
= main_map
->l_initfini
[i
];
2071 /* While we are at it, help the memory handling a bit. We have to
2072 mark some data structures as allocated with the fake malloc()
2073 implementation in ld.so. */
2074 struct libname_list
*lnp
= l
->l_libname
->next
;
2076 while (__builtin_expect (lnp
!= NULL
, 0))
2081 /* Also allocated with the fake malloc(). */
2082 l
->l_free_initfini
= 0;
2084 if (l
!= &GL(dl_rtld_map
))
2085 _dl_relocate_object (l
, l
->l_scope
, GLRO(dl_lazy
) ? RTLD_LAZY
: 0,
2086 consider_profiling
);
2088 /* Add object to slot information data if necessasy. */
2089 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2090 _dl_add_to_slotinfo (l
);
2092 HP_TIMING_NOW (stop
);
2094 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2096 /* Now enable profiling if needed. Like the previous call,
2097 this has to go here because the calls it makes should use the
2098 rtld versions of the functions (particularly calloc()), but it
2099 needs to have _dl_profile_map set up by the relocator. */
2100 if (__glibc_unlikely (GL(dl_profile_map
) != NULL
))
2101 /* We must prepare the profiling. */
2102 _dl_start_profile ();
2105 if ((!was_tls_init_tp_called
&& GL(dl_tls_max_dtv_idx
) > 0)
2106 || count_modids
!= _dl_count_modids ())
2107 ++GL(dl_tls_generation
);
2109 /* Now that we have completed relocation, the initializer data
2110 for the TLS blocks has its final values and we can copy them
2111 into the main thread's TLS area, which we allocated above. */
2112 _dl_allocate_tls_init (tcbp
);
2114 /* And finally install it for the main thread. */
2115 if (! tls_init_tp_called
)
2117 const char *lossage
= TLS_INIT_TP (tcbp
);
2118 if (__glibc_unlikely (lossage
!= NULL
))
2119 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2123 /* Make sure no new search directories have been added. */
2124 assert (GLRO(dl_init_all_dirs
) == GL(dl_all_dirs
));
2126 if (! prelinked
&& rtld_multiple_ref
)
2128 /* There was an explicit ref to the dynamic linker as a shared lib.
2129 Re-relocate ourselves with user-controlled symbol definitions.
2131 We must do this after TLS initialization in case after this
2132 re-relocation, we might call a user-supplied function
2133 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2135 #ifndef HP_TIMING_NONAVAIL
2141 HP_TIMING_NOW (start
);
2142 /* Mark the link map as not yet relocated again. */
2143 GL(dl_rtld_map
).l_relocated
= 0;
2144 _dl_relocate_object (&GL(dl_rtld_map
), main_map
->l_scope
, 0, 0);
2145 HP_TIMING_NOW (stop
);
2146 HP_TIMING_DIFF (add
, start
, stop
);
2147 HP_TIMING_ACCUM_NT (relocate_time
, add
);
2150 /* Do any necessary cleanups for the startup OS interface code.
2151 We do these now so that no calls are made after rtld re-relocation
2152 which might be resolved to different functions than we expect.
2153 We cannot do this before relocating the other objects because
2154 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2155 _dl_sysdep_start_cleanup ();
2158 /* Auditing checkpoint: we have added all objects. */
2159 if (__glibc_unlikely (GLRO(dl_naudit
) > 0))
2161 struct link_map
*head
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2162 /* Do not call the functions for any auditing object. */
2163 if (head
->l_auditing
== 0)
2165 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2166 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2168 if (afct
->activity
!= NULL
)
2169 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_CONSISTENT
);
2177 /* Notify the debugger all new objects are now ready to go. We must re-get
2178 the address since by now the variable might be in another object. */
2179 r
= _dl_debug_initialize (0, LM_ID_BASE
);
2180 r
->r_state
= RT_CONSISTENT
;
2182 LIBC_PROBE (init_complete
, 2, LM_ID_BASE
, r
);
2184 #if defined USE_LDCONFIG && !defined MAP_COPY
2185 /* We must munmap() the cache file. */
2186 _dl_unload_cache ();
2189 /* Once we return, _dl_sysdep_start will invoke
2190 the DT_INIT functions and then *USER_ENTRY. */
2193 /* This is a little helper function for resolving symbols while
2194 tracing the binary. */
2196 print_unresolved (int errcode
__attribute__ ((unused
)), const char *objname
,
2197 const char *errstring
)
2199 if (objname
[0] == '\0')
2200 objname
= RTLD_PROGNAME
;
2201 _dl_error_printf ("%s (%s)\n", errstring
, objname
);
2204 /* This is a little helper function for resolving symbols while
2205 tracing the binary. */
2207 print_missing_version (int errcode
__attribute__ ((unused
)),
2208 const char *objname
, const char *errstring
)
2210 _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME
,
2211 objname
, errstring
);
2214 /* Nonzero if any of the debugging options is enabled. */
2215 static int any_debug attribute_relro
;
2217 /* Process the string given as the parameter which explains which debugging
2218 options are enabled. */
2220 process_dl_debug (const char *dl_debug
)
2222 /* When adding new entries make sure that the maximal length of a name
2223 is correctly handled in the LD_DEBUG_HELP code below. */
2227 const char name
[10];
2228 const char helptext
[41];
2229 unsigned short int mask
;
2232 #define LEN_AND_STR(str) sizeof (str) - 1, str
2233 { LEN_AND_STR ("libs"), "display library search paths",
2234 DL_DEBUG_LIBS
| DL_DEBUG_IMPCALLS
},
2235 { LEN_AND_STR ("reloc"), "display relocation processing",
2236 DL_DEBUG_RELOC
| DL_DEBUG_IMPCALLS
},
2237 { LEN_AND_STR ("files"), "display progress for input file",
2238 DL_DEBUG_FILES
| DL_DEBUG_IMPCALLS
},
2239 { LEN_AND_STR ("symbols"), "display symbol table processing",
2240 DL_DEBUG_SYMBOLS
| DL_DEBUG_IMPCALLS
},
2241 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2242 DL_DEBUG_BINDINGS
| DL_DEBUG_IMPCALLS
},
2243 { LEN_AND_STR ("versions"), "display version dependencies",
2244 DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
},
2245 { LEN_AND_STR ("scopes"), "display scope information",
2247 { LEN_AND_STR ("all"), "all previous options combined",
2248 DL_DEBUG_LIBS
| DL_DEBUG_RELOC
| DL_DEBUG_FILES
| DL_DEBUG_SYMBOLS
2249 | DL_DEBUG_BINDINGS
| DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
2250 | DL_DEBUG_SCOPES
},
2251 { LEN_AND_STR ("statistics"), "display relocation statistics",
2252 DL_DEBUG_STATISTICS
},
2253 { LEN_AND_STR ("unused"), "determined unused DSOs",
2255 { LEN_AND_STR ("help"), "display this help message and exit",
2258 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2260 /* Skip separating white spaces and commas. */
2261 while (*dl_debug
!= '\0')
2263 if (*dl_debug
!= ' ' && *dl_debug
!= ',' && *dl_debug
!= ':')
2268 while (dl_debug
[len
] != '\0' && dl_debug
[len
] != ' '
2269 && dl_debug
[len
] != ',' && dl_debug
[len
] != ':')
2272 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2273 if (debopts
[cnt
].len
== len
2274 && memcmp (dl_debug
, debopts
[cnt
].name
, len
) == 0)
2276 GLRO(dl_debug_mask
) |= debopts
[cnt
].mask
;
2281 if (cnt
== ndebopts
)
2283 /* Display a warning and skip everything until next
2285 char *copy
= strndupa (dl_debug
, len
);
2286 _dl_error_printf ("\
2287 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy
);
2297 if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
2299 /* In order to get an accurate picture of whether a particular
2300 DT_NEEDED entry is actually used we have to process both
2301 the PLT and non-PLT relocation entries. */
2305 if (GLRO(dl_debug_mask
) & DL_DEBUG_HELP
)
2310 Valid options for the LD_DEBUG environment variable are:\n\n");
2312 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2313 _dl_printf (" %.*s%s%s\n", debopts
[cnt
].len
, debopts
[cnt
].name
,
2314 " " + debopts
[cnt
].len
- 3,
2315 debopts
[cnt
].helptext
);
2318 To direct the debugging output into a file instead of standard output\n\
2319 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2325 process_dl_audit (char *str
)
2327 /* The parameter is a colon separated list of DSO names. */
2330 while ((p
= (strsep
) (&str
, ":")) != NULL
)
2332 && (__builtin_expect (! INTUSE(__libc_enable_secure
), 1)
2333 || strchr (p
, '/') == NULL
))
2335 /* This is using the local malloc, not the system malloc. The
2336 memory can never be freed. */
2337 struct audit_list
*newp
= malloc (sizeof (*newp
));
2340 if (audit_list
== NULL
)
2341 audit_list
= newp
->next
= newp
;
2344 newp
->next
= audit_list
->next
;
2345 audit_list
= audit_list
->next
= newp
;
2350 /* Process all environments variables the dynamic linker must recognize.
2351 Since all of them start with `LD_' we are a bit smarter while finding
2353 extern char **_environ attribute_hidden
;
2357 process_envvars (enum mode
*modep
)
2359 char **runp
= _environ
;
2361 enum mode mode
= normal
;
2362 char *debug_output
= NULL
;
2364 /* This is the default place for profiling data file. */
2365 GLRO(dl_profile_output
)
2366 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure
) ? 9 : 0];
2368 while ((envline
= _dl_next_ld_env_entry (&runp
)) != NULL
)
2372 while (envline
[len
] != '\0' && envline
[len
] != '=')
2375 if (envline
[len
] != '=')
2376 /* This is a "LD_" variable at the end of the string without
2377 a '=' character. Ignore it since otherwise we will access
2378 invalid memory below. */
2384 /* Warning level, verbose or not. */
2385 if (memcmp (envline
, "WARN", 4) == 0)
2386 GLRO(dl_verbose
) = envline
[5] != '\0';
2390 /* Debugging of the dynamic linker? */
2391 if (memcmp (envline
, "DEBUG", 5) == 0)
2393 process_dl_debug (&envline
[6]);
2396 if (memcmp (envline
, "AUDIT", 5) == 0)
2397 process_dl_audit (&envline
[6]);
2401 /* Print information about versions. */
2402 if (memcmp (envline
, "VERBOSE", 7) == 0)
2404 version_info
= envline
[8] != '\0';
2408 /* List of objects to be preloaded. */
2409 if (memcmp (envline
, "PRELOAD", 7) == 0)
2411 preloadlist
= &envline
[8];
2415 /* Which shared object shall be profiled. */
2416 if (memcmp (envline
, "PROFILE", 7) == 0 && envline
[8] != '\0')
2417 GLRO(dl_profile
) = &envline
[8];
2421 /* Do we bind early? */
2422 if (memcmp (envline
, "BIND_NOW", 8) == 0)
2424 GLRO(dl_lazy
) = envline
[9] == '\0';
2427 if (memcmp (envline
, "BIND_NOT", 8) == 0)
2428 GLRO(dl_bind_not
) = envline
[9] != '\0';
2432 /* Test whether we want to see the content of the auxiliary
2433 array passed up from the kernel. */
2434 if (!INTUSE(__libc_enable_secure
)
2435 && memcmp (envline
, "SHOW_AUXV", 9) == 0)
2440 /* Mask for the important hardware capabilities. */
2441 if (memcmp (envline
, "HWCAP_MASK", 10) == 0)
2442 GLRO(dl_hwcap_mask
) = __strtoul_internal (&envline
[11], NULL
,
2447 /* Path where the binary is found. */
2448 if (!INTUSE(__libc_enable_secure
)
2449 && memcmp (envline
, "ORIGIN_PATH", 11) == 0)
2450 GLRO(dl_origin_path
) = &envline
[12];
2454 /* The library search path. */
2455 if (memcmp (envline
, "LIBRARY_PATH", 12) == 0)
2457 library_path
= &envline
[13];
2461 /* Where to place the profiling data file. */
2462 if (memcmp (envline
, "DEBUG_OUTPUT", 12) == 0)
2464 debug_output
= &envline
[13];
2468 if (!INTUSE(__libc_enable_secure
)
2469 && memcmp (envline
, "DYNAMIC_WEAK", 12) == 0)
2470 GLRO(dl_dynamic_weak
) = 1;
2474 /* We might have some extra environment variable with length 13
2476 #ifdef EXTRA_LD_ENVVARS_13
2479 if (!INTUSE(__libc_enable_secure
)
2480 && memcmp (envline
, "USE_LOAD_BIAS", 13) == 0)
2482 GLRO(dl_use_load_bias
) = envline
[14] == '1' ? -1 : 0;
2486 if (memcmp (envline
, "POINTER_GUARD", 13) == 0)
2487 GLRO(dl_pointer_guard
) = envline
[14] != '0';
2491 /* Where to place the profiling data file. */
2492 if (!INTUSE(__libc_enable_secure
)
2493 && memcmp (envline
, "PROFILE_OUTPUT", 14) == 0
2494 && envline
[15] != '\0')
2495 GLRO(dl_profile_output
) = &envline
[15];
2499 /* The mode of the dynamic linker can be set. */
2500 if (memcmp (envline
, "TRACE_PRELINKING", 16) == 0)
2503 GLRO(dl_verbose
) = 1;
2504 GLRO(dl_debug_mask
) |= DL_DEBUG_PRELINK
;
2505 GLRO(dl_trace_prelink
) = &envline
[17];
2510 /* The mode of the dynamic linker can be set. */
2511 if (memcmp (envline
, "TRACE_LOADED_OBJECTS", 20) == 0)
2515 /* We might have some extra environment variable to handle. This
2516 is tricky due to the pre-processing of the length of the name
2517 in the switch statement here. The code here assumes that added
2518 environment variables have a different length. */
2519 #ifdef EXTRA_LD_ENVVARS
2525 /* The caller wants this information. */
2528 /* Extra security for SUID binaries. Remove all dangerous environment
2530 if (__builtin_expect (INTUSE(__libc_enable_secure
), 0))
2532 static const char unsecure_envvars
[] =
2533 #ifdef EXTRA_UNSECURE_ENVVARS
2534 EXTRA_UNSECURE_ENVVARS
2539 nextp
= unsecure_envvars
;
2543 /* We could use rawmemchr but this need not be fast. */
2544 nextp
= (char *) (strchr
) (nextp
, '\0') + 1;
2546 while (*nextp
!= '\0');
2548 if (__access ("/etc/suid-debug", F_OK
) != 0)
2550 unsetenv ("MALLOC_CHECK_");
2551 GLRO(dl_debug_mask
) = 0;
2557 /* If we have to run the dynamic linker in debugging mode and the
2558 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2559 messages to this file. */
2560 else if (any_debug
&& debug_output
!= NULL
)
2563 const int flags
= O_WRONLY
| O_APPEND
| O_CREAT
| O_NOFOLLOW
;
2565 const int flags
= O_WRONLY
| O_APPEND
| O_CREAT
;
2567 size_t name_len
= strlen (debug_output
);
2568 char buf
[name_len
+ 12];
2571 buf
[name_len
+ 11] = '\0';
2572 startp
= _itoa (__getpid (), &buf
[name_len
+ 11], 10, 0);
2574 startp
= memcpy (startp
- name_len
, debug_output
, name_len
);
2576 GLRO(dl_debug_fd
) = __open (startp
, flags
, DEFFILEMODE
);
2577 if (GLRO(dl_debug_fd
) == -1)
2578 /* We use standard output if opening the file failed. */
2579 GLRO(dl_debug_fd
) = STDOUT_FILENO
;
2584 /* Print the various times we collected. */
2586 __attribute ((noinline
))
2587 print_statistics (hp_timing_t
*rtld_total_timep
)
2589 #ifndef HP_TIMING_NONAVAIL
2594 /* Total time rtld used. */
2595 if (HP_TIMING_AVAIL
)
2597 HP_TIMING_PRINT (buf
, sizeof (buf
), *rtld_total_timep
);
2598 _dl_debug_printf ("\nruntime linker statistics:\n"
2599 " total startup time in dynamic loader: %s\n", buf
);
2601 /* Print relocation statistics. */
2603 HP_TIMING_PRINT (buf
, sizeof (buf
), relocate_time
);
2604 cp
= _itoa ((1000ULL * relocate_time
) / *rtld_total_timep
,
2605 pbuf
+ sizeof (pbuf
), 10, 0);
2607 switch (pbuf
+ sizeof (pbuf
) - cp
)
2618 _dl_debug_printf ("\
2619 time needed for relocation: %s (%s%%)\n", buf
, pbuf
);
2623 unsigned long int num_relative_relocations
= 0;
2624 for (Lmid_t ns
= 0; ns
< GL(dl_nns
); ++ns
)
2626 if (GL(dl_ns
)[ns
]._ns_loaded
== NULL
)
2629 struct r_scope_elem
*scope
= &GL(dl_ns
)[ns
]._ns_loaded
->l_searchlist
;
2631 for (unsigned int i
= 0; i
< scope
->r_nlist
; i
++)
2633 struct link_map
*l
= scope
->r_list
[i
];
2635 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELCOUNT
)])
2636 num_relative_relocations
2637 += l
->l_info
[VERSYMIDX (DT_RELCOUNT
)]->d_un
.d_val
;
2638 #ifndef ELF_MACHINE_REL_RELATIVE
2639 /* Relative relocations are processed on these architectures if
2640 library is loaded to different address than p_vaddr or
2641 if not prelinked. */
2642 if ((l
->l_addr
!= 0 || !l
->l_info
[VALIDX(DT_GNU_PRELINKED
)])
2643 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2645 /* On e.g. IA-64 or Alpha, relative relocations are processed
2646 only if library is loaded to different address than p_vaddr. */
2647 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2649 num_relative_relocations
2650 += l
->l_info
[VERSYMIDX (DT_RELACOUNT
)]->d_un
.d_val
;
2654 _dl_debug_printf (" number of relocations: %lu\n"
2655 " number of relocations from cache: %lu\n"
2656 " number of relative relocations: %lu\n",
2657 GL(dl_num_relocations
),
2658 GL(dl_num_cache_relocations
),
2659 num_relative_relocations
);
2661 #ifndef HP_TIMING_NONAVAIL
2662 /* Time spend while loading the object and the dependencies. */
2663 if (HP_TIMING_AVAIL
)
2666 HP_TIMING_PRINT (buf
, sizeof (buf
), load_time
);
2667 cp
= _itoa ((1000ULL * load_time
) / *rtld_total_timep
,
2668 pbuf
+ sizeof (pbuf
), 10, 0);
2670 switch (pbuf
+ sizeof (pbuf
) - cp
)
2681 _dl_debug_printf ("\
2682 time needed to load objects: %s (%s%%)\n",