1 /* Run time dynamic linker.
2 Copyright (C) 1995-2013 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
304 assert (info
->l
.l_tls_modid
!= 0);
305 GL(dl_rtld_map
).l_tls_blocksize
= info
->l
.l_tls_blocksize
;
306 GL(dl_rtld_map
).l_tls_align
= info
->l
.l_tls_align
;
307 GL(dl_rtld_map
).l_tls_firstbyte_offset
= info
->l
.l_tls_firstbyte_offset
;
308 GL(dl_rtld_map
).l_tls_initimage_size
= info
->l
.l_tls_initimage_size
;
309 GL(dl_rtld_map
).l_tls_initimage
= info
->l
.l_tls_initimage
;
310 GL(dl_rtld_map
).l_tls_offset
= info
->l
.l_tls_offset
;
311 GL(dl_rtld_map
).l_tls_modid
= 1;
313 # if NO_TLS_OFFSET != 0
314 GL(dl_rtld_map
).l_tls_offset
= NO_TLS_OFFSET
;
321 HP_TIMING_NOW (GL(dl_cpuclock_offset
));
324 /* Initialize the stack end variable. */
325 __libc_stack_end
= __builtin_frame_address (0);
327 /* Call the OS-dependent function to set up life so we can do things like
328 file access. It will call `dl_main' (below) to do all the real work
329 of the dynamic linker, and then unwind our frame and run the user
330 entry point on the same stack we entered on. */
331 start_addr
= _dl_sysdep_start (arg
, &dl_main
);
333 #ifndef HP_TIMING_NONAVAIL
334 hp_timing_t rtld_total_time
;
337 hp_timing_t end_time
;
339 /* Get the current time. */
340 HP_TIMING_NOW (end_time
);
342 /* Compute the difference. */
343 HP_TIMING_DIFF (rtld_total_time
, start_time
, end_time
);
347 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_STATISTICS
, 0))
349 #ifndef HP_TIMING_NONAVAIL
350 print_statistics (&rtld_total_time
);
352 print_statistics (NULL
);
359 static ElfW(Addr
) __attribute_used__ internal_function
360 _dl_start (void *arg
)
362 #ifdef DONT_USE_BOOTSTRAP_MAP
363 # define bootstrap_map GL(dl_rtld_map)
365 struct dl_start_final_info info
;
366 # define bootstrap_map info.l
369 /* This #define produces dynamic linking inline functions for
370 bootstrap relocation instead of general-purpose relocation.
371 Since ld.so must not have any undefined symbols the result
372 is trivial: always the map of ld.so itself. */
373 #define RTLD_BOOTSTRAP
374 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
375 #include "dynamic-link.h"
377 if (HP_TIMING_INLINE
&& HP_TIMING_AVAIL
)
378 #ifdef DONT_USE_BOOTSTRAP_MAP
379 HP_TIMING_NOW (start_time
);
381 HP_TIMING_NOW (info
.start_time
);
384 /* Partly clean the `bootstrap_map' structure up. Don't use
385 `memset' since it might not be built in or inlined and we cannot
386 make function calls at this point. Use '__builtin_memset' if we
387 know it is available. We do not have to clear the memory if we
388 do not have to use the temporary bootstrap_map. Global variables
389 are initialized to zero by default. */
390 #ifndef DONT_USE_BOOTSTRAP_MAP
391 # ifdef HAVE_BUILTIN_MEMSET
392 __builtin_memset (bootstrap_map
.l_info
, '\0', sizeof (bootstrap_map
.l_info
));
395 cnt
< sizeof (bootstrap_map
.l_info
) / sizeof (bootstrap_map
.l_info
[0]);
397 bootstrap_map
.l_info
[cnt
] = 0;
400 bootstrap_map
.l_tls_modid
= 0;
404 /* Figure out the run-time load address of the dynamic linker itself. */
405 bootstrap_map
.l_addr
= elf_machine_load_address ();
407 /* Read our own dynamic section and fill in the info array. */
408 bootstrap_map
.l_ld
= (void *) bootstrap_map
.l_addr
+ elf_machine_dynamic ();
409 elf_get_dynamic_info (&bootstrap_map
, NULL
);
411 #if NO_TLS_OFFSET != 0
412 bootstrap_map
.l_tls_offset
= NO_TLS_OFFSET
;
415 /* Get the dynamic linker's own program header. First we need the ELF
416 file header. The `_begin' symbol created by the linker script points
417 to it. When we have something like GOTOFF relocs, we can use a plain
418 reference to find the runtime address. Without that, we have to rely
419 on the `l_addr' value, which is not the value we want when prelinked. */
423 # ifdef DONT_USE_BOOTSTRAP_MAP
424 = (ElfW(Ehdr
) *) &_begin
;
426 # error This will not work with prelink.
427 = (ElfW(Ehdr
) *) bootstrap_map
.l_addr
;
429 ElfW(Phdr
) *phdr
= (ElfW(Phdr
) *) ((void *) ehdr
+ ehdr
->e_phoff
);
430 size_t cnt
= ehdr
->e_phnum
; /* PT_TLS is usually the last phdr. */
432 if (phdr
[cnt
].p_type
== PT_TLS
)
435 size_t max_align
= MAX (TLS_INIT_TCB_ALIGN
, phdr
[cnt
].p_align
);
438 bootstrap_map
.l_tls_blocksize
= phdr
[cnt
].p_memsz
;
439 bootstrap_map
.l_tls_align
= phdr
[cnt
].p_align
;
440 if (phdr
[cnt
].p_align
== 0)
441 bootstrap_map
.l_tls_firstbyte_offset
= 0;
443 bootstrap_map
.l_tls_firstbyte_offset
= (phdr
[cnt
].p_vaddr
444 & (phdr
[cnt
].p_align
- 1));
445 assert (bootstrap_map
.l_tls_blocksize
!= 0);
446 bootstrap_map
.l_tls_initimage_size
= phdr
[cnt
].p_filesz
;
447 bootstrap_map
.l_tls_initimage
= (void *) (bootstrap_map
.l_addr
448 + phdr
[cnt
].p_vaddr
);
450 /* We can now allocate the initial TLS block. This can happen
451 on the stack. We'll get the final memory later when we
452 know all about the various objects loaded at startup
455 tlsblock
= alloca (roundup (bootstrap_map
.l_tls_blocksize
,
460 tlsblock
= alloca (roundup (TLS_INIT_TCB_SIZE
,
461 bootstrap_map
.l_tls_align
)
462 + bootstrap_map
.l_tls_blocksize
465 /* In case a model with a different layout for the TCB and DTV
466 is defined add another #elif here and in the following #ifs. */
467 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
469 /* Align the TLS block. */
470 tlsblock
= (void *) (((uintptr_t) tlsblock
+ max_align
- 1)
473 /* Initialize the dtv. [0] is the length, [1] the generation
475 initdtv
[0].counter
= 1;
476 initdtv
[1].counter
= 0;
478 /* Initialize the TLS block. */
480 initdtv
[2].pointer
= tlsblock
;
482 bootstrap_map
.l_tls_offset
= roundup (TLS_INIT_TCB_SIZE
,
483 bootstrap_map
.l_tls_align
);
484 initdtv
[2].pointer
= (char *) tlsblock
+ bootstrap_map
.l_tls_offset
;
486 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
488 p
= __mempcpy (initdtv
[2].pointer
, bootstrap_map
.l_tls_initimage
,
489 bootstrap_map
.l_tls_initimage_size
);
490 # ifdef HAVE_BUILTIN_MEMSET
491 __builtin_memset (p
, '\0', (bootstrap_map
.l_tls_blocksize
492 - bootstrap_map
.l_tls_initimage_size
));
495 size_t remaining
= (bootstrap_map
.l_tls_blocksize
496 - bootstrap_map
.l_tls_initimage_size
);
497 while (remaining
-- > 0)
502 /* Install the pointer to the dtv. */
504 /* Initialize the thread pointer. */
506 bootstrap_map
.l_tls_offset
507 = roundup (bootstrap_map
.l_tls_blocksize
, TLS_INIT_TCB_ALIGN
);
509 INSTALL_DTV ((char *) tlsblock
+ bootstrap_map
.l_tls_offset
,
512 const char *lossage
= TLS_INIT_TP ((char *) tlsblock
513 + bootstrap_map
.l_tls_offset
, 0);
515 INSTALL_DTV (tlsblock
, initdtv
);
516 const char *lossage
= TLS_INIT_TP (tlsblock
, 0);
518 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
520 if (__builtin_expect (lossage
!= NULL
, 0))
521 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
524 /* So far this is module number one. */
525 bootstrap_map
.l_tls_modid
= 1;
527 /* There can only be one PT_TLS entry. */
530 #endif /* USE___THREAD */
532 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
533 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map
.l_info
);
536 if (bootstrap_map
.l_addr
|| ! bootstrap_map
.l_info
[VALIDX(DT_GNU_PRELINKED
)])
538 /* Relocate ourselves so we can do normal function calls and
539 data access using the global offset table. */
541 ELF_DYNAMIC_RELOCATE (&bootstrap_map
, 0, 0, 0);
543 bootstrap_map
.l_relocated
= 1;
545 /* Please note that we don't allow profiling of this object and
546 therefore need not test whether we have to allocate the array
547 for the relocation results (as done in dl-reloc.c). */
549 /* Now life is sane; we can call functions and access global data.
550 Set up to use the operating system facilities, and find out from
551 the operating system's program loader where to find the program
552 header table in core. Put the rest of _dl_start into a separate
553 function, that way the compiler cannot put accesses to the GOT
554 before ELF_DYNAMIC_RELOCATE. */
556 #ifdef DONT_USE_BOOTSTRAP_MAP
557 ElfW(Addr
) entry
= _dl_start_final (arg
);
559 ElfW(Addr
) entry
= _dl_start_final (arg
, &info
);
562 #ifndef ELF_MACHINE_START_ADDRESS
563 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
566 return ELF_MACHINE_START_ADDRESS (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, entry
);
572 /* Now life is peachy; we can do all normal operations.
573 On to the real work. */
575 /* Some helper functions. */
577 /* Arguments to relocate_doit. */
586 /* Argument to map_doit. */
588 struct link_map
*loader
;
590 /* Return value of map_doit. */
591 struct link_map
*map
;
597 struct link_map
*map
;
603 struct link_map
*map
;
607 /* Arguments to version_check_doit. */
608 struct version_check_args
615 relocate_doit (void *a
)
617 struct relocate_args
*args
= (struct relocate_args
*) a
;
619 _dl_relocate_object (args
->l
, args
->l
->l_scope
, args
->reloc_mode
, 0);
625 struct map_args
*args
= (struct map_args
*) a
;
626 args
->map
= _dl_map_object (args
->loader
, args
->str
, lt_library
, 0,
627 args
->mode
, LM_ID_BASE
);
631 dlmopen_doit (void *a
)
633 struct dlmopen_args
*args
= (struct dlmopen_args
*) a
;
634 args
->map
= _dl_open (args
->fname
,
635 (RTLD_LAZY
| __RTLD_DLOPEN
| __RTLD_AUDIT
637 dl_main
, LM_ID_NEWLM
, _dl_argc
, INTUSE(_dl_argv
),
642 lookup_doit (void *a
)
644 struct lookup_args
*args
= (struct lookup_args
*) a
;
645 const ElfW(Sym
) *ref
= NULL
;
647 lookup_t l
= _dl_lookup_symbol_x (args
->name
, args
->map
, &ref
,
648 args
->map
->l_local_scope
, NULL
, 0,
649 DL_LOOKUP_RETURN_NEWEST
, NULL
);
651 args
->result
= DL_SYMBOL_ADDRESS (l
, ref
);
655 version_check_doit (void *a
)
657 struct version_check_args
*args
= (struct version_check_args
*) a
;
658 if (_dl_check_all_versions (GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
, 1,
659 args
->dotrace
) && args
->doexit
)
660 /* We cannot start the application. Abort now. */
665 static inline struct link_map
*
666 find_needed (const char *name
)
668 struct r_scope_elem
*scope
= &GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
->l_searchlist
;
669 unsigned int n
= scope
->r_nlist
;
672 if (_dl_name_match_p (name
, scope
->r_list
[n
]))
673 return scope
->r_list
[n
];
675 /* Should never happen. */
680 match_version (const char *string
, struct link_map
*map
)
682 const char *strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
685 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
686 if (map
->l_info
[VERDEFTAG
] == NULL
)
687 /* The file has no symbol versioning. */
690 def
= (ElfW(Verdef
) *) ((char *) map
->l_addr
691 + map
->l_info
[VERDEFTAG
]->d_un
.d_ptr
);
694 ElfW(Verdaux
) *aux
= (ElfW(Verdaux
) *) ((char *) def
+ def
->vd_aux
);
696 /* Compare the version strings. */
697 if (strcmp (string
, strtab
+ aux
->vda_name
) == 0)
701 /* If no more definitions we failed to find what we want. */
702 if (def
->vd_next
== 0)
705 /* Next definition. */
706 def
= (ElfW(Verdef
) *) ((char *) def
+ def
->vd_next
);
712 static bool tls_init_tp_called
;
717 /* Number of elements in the static TLS block. */
718 GL(dl_tls_static_nelem
) = GL(dl_tls_max_dtv_idx
);
720 /* Do not do this twice. The audit interface might have required
721 the DTV interfaces to be set up early. */
722 if (GL(dl_initial_dtv
) != NULL
)
725 /* Allocate the array which contains the information about the
726 dtv slots. We allocate a few entries more than needed to
727 avoid the need for reallocation. */
728 size_t nelem
= GL(dl_tls_max_dtv_idx
) + 1 + TLS_SLOTINFO_SURPLUS
;
731 GL(dl_tls_dtv_slotinfo_list
) = (struct dtv_slotinfo_list
*)
732 calloc (sizeof (struct dtv_slotinfo_list
)
733 + nelem
* sizeof (struct dtv_slotinfo
), 1);
734 /* No need to check the return value. If memory allocation failed
735 the program would have been terminated. */
737 struct dtv_slotinfo
*slotinfo
= GL(dl_tls_dtv_slotinfo_list
)->slotinfo
;
738 GL(dl_tls_dtv_slotinfo_list
)->len
= nelem
;
739 GL(dl_tls_dtv_slotinfo_list
)->next
= NULL
;
741 /* Fill in the information from the loaded modules. No namespace
742 but the base one can be filled at this time. */
743 assert (GL(dl_ns
)[LM_ID_BASE
+ 1]._ns_loaded
== NULL
);
745 for (struct link_map
*l
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
; l
!= NULL
;
747 if (l
->l_tls_blocksize
!= 0)
749 /* This is a module with TLS data. Store the map reference.
750 The generation counter is zero. */
752 /* slotinfo[i].gen = 0; */
755 assert (i
== GL(dl_tls_max_dtv_idx
));
757 /* Compute the TLS offsets for the various blocks. */
758 _dl_determine_tlsoffset ();
760 /* Construct the static TLS block and the dtv for the initial
761 thread. For some platforms this will include allocating memory
762 for the thread descriptor. The memory for the TLS block will
763 never be freed. It should be allocated accordingly. The dtv
764 array can be changed if dynamic loading requires it. */
765 void *tcbp
= _dl_allocate_tls_storage ();
768 cannot allocate TLS data structures for initial thread");
770 /* Store for detection of the special case by __tls_get_addr
771 so it knows not to pass this dtv to the normal realloc. */
772 GL(dl_initial_dtv
) = GET_DTV (tcbp
);
774 /* And finally install it for the main thread. If ld.so itself uses
775 TLS we know the thread pointer was initialized earlier. */
778 = TLS_INIT_TP (tcbp
, USE___THREAD
);
780 = TLS_INIT_TP (tcbp
, 0);
782 if (__builtin_expect (lossage
!= NULL
, 0))
783 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage
);
784 tls_init_tp_called
= true;
789 #ifdef _LIBC_REENTRANT
790 /* _dl_error_catch_tsd points to this for the single-threaded case.
791 It's reset by the thread library for multithreaded programs. */
792 void ** __attribute__ ((const))
793 _dl_initial_error_catch_tsd (void)
802 do_preload (char *fname
, struct link_map
*main_map
, const char *where
)
805 const char *err_str
= NULL
;
806 struct map_args args
;
810 args
.loader
= main_map
;
811 args
.mode
= __RTLD_SECURE
;
813 unsigned int old_nloaded
= GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
815 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
, &args
);
816 if (__builtin_expect (err_str
!= NULL
, 0))
819 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
821 /* No need to call free, this is still before
822 the libc's malloc is used. */
824 else if (GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
!= old_nloaded
)
825 /* It is no duplicate. */
828 /* Nothing loaded. */
832 #if defined SHARED && defined _LIBC_REENTRANT \
833 && defined __rtld_lock_default_lock_recursive
835 rtld_lock_default_lock_recursive (void *lock
)
837 __rtld_lock_default_lock_recursive (lock
);
841 rtld_lock_default_unlock_recursive (void *lock
)
843 __rtld_lock_default_unlock_recursive (lock
);
851 /* Set up the stack checker's canary. */
852 uintptr_t stack_chk_guard
= _dl_setup_stack_chk_guard (_dl_random
);
853 #ifdef THREAD_SET_STACK_GUARD
854 THREAD_SET_STACK_GUARD (stack_chk_guard
);
856 __stack_chk_guard
= stack_chk_guard
;
859 /* Set up the pointer guard as well, if necessary. */
860 if (GLRO(dl_pointer_guard
))
862 uintptr_t pointer_chk_guard
= _dl_setup_pointer_guard (_dl_random
,
864 #ifdef THREAD_SET_POINTER_GUARD
865 THREAD_SET_POINTER_GUARD (pointer_chk_guard
);
867 __pointer_chk_guard_local
= pointer_chk_guard
;
870 /* We do not need the _dl_random value anymore. The less
871 information we leave behind, the better, so clear the
876 #include "setup-vdso.h"
878 /* The library search path. */
879 static const char *library_path attribute_relro
;
880 /* The list preloaded objects. */
881 static const char *preloadlist attribute_relro
;
882 /* Nonzero if information about versions has to be printed. */
883 static int version_info attribute_relro
;
886 dl_main (const ElfW(Phdr
) *phdr
,
888 ElfW(Addr
) *user_entry
,
891 const ElfW(Phdr
) *ph
;
893 struct link_map
*main_map
;
896 bool has_interp
= false;
898 bool prelinked
= false;
899 bool rtld_is_main
= false;
900 #ifndef HP_TIMING_NONAVAIL
907 #ifdef _LIBC_REENTRANT
908 /* Explicit initialization since the reloc would just be more work. */
909 GL(dl_error_catch_tsd
) = &_dl_initial_error_catch_tsd
;
912 GL(dl_init_static_tls
) = &_dl_nothread_init_static_tls
;
914 #if defined SHARED && defined _LIBC_REENTRANT \
915 && defined __rtld_lock_default_lock_recursive
916 GL(dl_rtld_lock_recursive
) = rtld_lock_default_lock_recursive
;
917 GL(dl_rtld_unlock_recursive
) = rtld_lock_default_unlock_recursive
;
920 /* The explicit initialization here is cheaper than processing the reloc
921 in the _rtld_local definition's initializer. */
922 GL(dl_make_stack_executable_hook
) = &_dl_make_stack_executable
;
924 /* Process the environment variable which control the behaviour. */
925 process_envvars (&mode
);
927 #ifndef HAVE_INLINED_SYSCALLS
928 /* Set up a flag which tells we are just starting. */
929 INTUSE(_dl_starting_up
) = 1;
932 if (*user_entry
== (ElfW(Addr
)) ENTRY_POINT
)
934 /* Ho ho. We are not the program interpreter! We are the program
935 itself! This means someone ran ld.so as a command. Well, that
936 might be convenient to do sometimes. We support it by
937 interpreting the args like this:
939 ld.so PROGRAM ARGS...
941 The first argument is the name of a file containing an ELF
942 executable we will load and run with the following arguments.
943 To simplify life here, PROGRAM is searched for using the
944 normal rules for shared objects, rather than $PATH or anything
945 like that. We just load it and use its entry point; we don't
946 pay attention to its PT_INTERP command (we are the interpreter
947 ourselves). This is an easy way to test a new ld.so before
951 /* Note the place where the dynamic linker actually came from. */
952 GL(dl_rtld_map
).l_name
= rtld_progname
;
955 if (! strcmp (INTUSE(_dl_argv
)[1], "--list"))
958 GLRO(dl_lazy
) = -1; /* This means do no dependency analysis. */
964 else if (! strcmp (INTUSE(_dl_argv
)[1], "--verify"))
972 else if (! strcmp (INTUSE(_dl_argv
)[1], "--inhibit-cache"))
974 GLRO(dl_inhibit_cache
) = 1;
979 else if (! strcmp (INTUSE(_dl_argv
)[1], "--library-path")
982 library_path
= INTUSE(_dl_argv
)[2];
986 INTUSE(_dl_argv
) += 2;
988 else if (! strcmp (INTUSE(_dl_argv
)[1], "--inhibit-rpath")
991 GLRO(dl_inhibit_rpath
) = INTUSE(_dl_argv
)[2];
995 INTUSE(_dl_argv
) += 2;
997 else if (! strcmp (INTUSE(_dl_argv
)[1], "--audit") && _dl_argc
> 2)
999 process_dl_audit (INTUSE(_dl_argv
)[2]);
1003 INTUSE(_dl_argv
) += 2;
1008 /* If we have no further argument the program was called incorrectly.
1009 Grant the user some education. */
1011 _dl_fatal_printf ("\
1012 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1013 You have invoked `ld.so', the helper program for shared library executables.\n\
1014 This program usually lives in the file `/lib/ld.so', and special directives\n\
1015 in executable files using ELF shared libraries tell the system's program\n\
1016 loader to load the helper program from this file. This helper program loads\n\
1017 the shared libraries needed by the program executable, prepares the program\n\
1018 to run, and runs it. You may invoke this helper program directly from the\n\
1019 command line to load and run an ELF executable file; this is like executing\n\
1020 that file itself, but always uses this helper program from the file you\n\
1021 specified, instead of the helper program file specified in the executable\n\
1022 file you run. This is mostly of use for maintainers to test new versions\n\
1023 of this helper program; chances are you did not intend to run this program.\n\
1025 --list list all dependencies and how they are resolved\n\
1026 --verify verify that given object really is a dynamically linked\n\
1027 object we can handle\n\
1028 --inhibit-cache Do not use " LD_SO_CACHE
"\n\
1029 --library-path PATH use given PATH instead of content of the environment\n\
1030 variable LD_LIBRARY_PATH\n\
1031 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1033 --audit LIST use objects named in LIST as auditors\n");
1039 /* The initialization of _dl_stack_flags done below assumes the
1040 executable's PT_GNU_STACK may have been honored by the kernel, and
1041 so a PT_GNU_STACK with PF_X set means the stack started out with
1042 execute permission. However, this is not really true if the
1043 dynamic linker is the executable the kernel loaded. For this
1044 case, we must reinitialize _dl_stack_flags to match the dynamic
1045 linker itself. If the dynamic linker was built with a
1046 PT_GNU_STACK, then the kernel may have loaded us with a
1047 nonexecutable stack that we will have to make executable when we
1048 load the program below unless it has a PT_GNU_STACK indicating
1049 nonexecutable stack is ok. */
1051 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
1052 if (ph
->p_type
== PT_GNU_STACK
)
1054 GL(dl_stack_flags
) = ph
->p_flags
;
1058 if (__builtin_expect (mode
, normal
) == verify
)
1060 const char *objname
;
1061 const char *err_str
= NULL
;
1062 struct map_args args
;
1065 args
.str
= rtld_progname
;
1067 args
.mode
= __RTLD_OPENEXEC
;
1068 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, map_doit
,
1070 if (__builtin_expect (err_str
!= NULL
, 0))
1071 /* We don't free the returned string, the programs stops
1073 _exit (EXIT_FAILURE
);
1077 HP_TIMING_NOW (start
);
1078 _dl_map_object (NULL
, rtld_progname
, lt_library
, 0,
1079 __RTLD_OPENEXEC
, LM_ID_BASE
);
1080 HP_TIMING_NOW (stop
);
1082 HP_TIMING_DIFF (load_time
, start
, stop
);
1085 /* Now the map for the main executable is available. */
1086 main_map
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
1088 if (__builtin_expect (mode
, normal
) == normal
1089 && GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
1090 && main_map
->l_info
[DT_SONAME
] != NULL
1091 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1092 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
,
1093 (const char *) D_PTR (main_map
, l_info
[DT_STRTAB
])
1094 + main_map
->l_info
[DT_SONAME
]->d_un
.d_val
) == 0)
1095 _dl_fatal_printf ("loader cannot load itself\n");
1097 phdr
= main_map
->l_phdr
;
1098 phnum
= main_map
->l_phnum
;
1099 /* We overwrite here a pointer to a malloc()ed string. But since
1100 the malloc() implementation used at this point is the dummy
1101 implementations which has no real free() function it does not
1102 makes sense to free the old string first. */
1103 main_map
->l_name
= (char *) "";
1104 *user_entry
= main_map
->l_entry
;
1106 #ifdef HAVE_AUX_VECTOR
1107 /* Adjust the on-stack auxiliary vector so that it looks like the
1108 binary was executed directly. */
1109 for (ElfW(auxv_t
) *av
= auxv
; av
->a_type
!= AT_NULL
; av
++)
1113 av
->a_un
.a_val
= (uintptr_t) phdr
;
1116 av
->a_un
.a_val
= phnum
;
1119 av
->a_un
.a_val
= *user_entry
;
1126 /* Create a link_map for the executable itself.
1127 This will be what dlopen on "" returns. */
1128 main_map
= _dl_new_object ((char *) "", "", lt_executable
, NULL
,
1129 __RTLD_OPENEXEC
, LM_ID_BASE
);
1130 assert (main_map
!= NULL
);
1131 main_map
->l_phdr
= phdr
;
1132 main_map
->l_phnum
= phnum
;
1133 main_map
->l_entry
= *user_entry
;
1135 /* Even though the link map is not yet fully initialized we can add
1136 it to the map list since there are no possible users running yet. */
1137 _dl_add_to_namespace_list (main_map
, LM_ID_BASE
);
1138 assert (main_map
== GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
);
1140 /* At this point we are in a bit of trouble. We would have to
1141 fill in the values for l_dev and l_ino. But in general we
1142 do not know where the file is. We also do not handle AT_EXECFD
1143 even if it would be passed up.
1145 We leave the values here defined to 0. This is normally no
1146 problem as the program code itself is normally no shared
1147 object and therefore cannot be loaded dynamically. Nothing
1148 prevent the use of dynamic binaries and in these situations
1149 we might get problems. We might not be able to find out
1150 whether the object is already loaded. But since there is no
1151 easy way out and because the dynamic binary must also not
1152 have an SONAME we ignore this program for now. If it becomes
1153 a problem we can force people using SONAMEs. */
1155 /* We delay initializing the path structure until we got the dynamic
1156 information for the program. */
1159 main_map
->l_map_end
= 0;
1160 main_map
->l_text_end
= 0;
1161 /* Perhaps the executable has no PT_LOAD header entries at all. */
1162 main_map
->l_map_start
= ~0;
1163 /* And it was opened directly. */
1164 ++main_map
->l_direct_opencount
;
1166 /* Scan the program header table for the dynamic section. */
1167 for (ph
= phdr
; ph
< &phdr
[phnum
]; ++ph
)
1171 /* Find out the load address. */
1172 main_map
->l_addr
= (ElfW(Addr
)) phdr
- ph
->p_vaddr
;
1175 /* This tells us where to find the dynamic section,
1176 which tells us everything we need to do. */
1177 main_map
->l_ld
= (void *) main_map
->l_addr
+ ph
->p_vaddr
;
1180 /* This "interpreter segment" was used by the program loader to
1181 find the program interpreter, which is this program itself, the
1182 dynamic linker. We note what name finds us, so that a future
1183 dlopen call or DT_NEEDED entry, for something that wants to link
1184 against the dynamic linker as a shared library, will know that
1185 the shared object is already loaded. */
1186 _dl_rtld_libname
.name
= ((const char *) main_map
->l_addr
1188 /* _dl_rtld_libname.next = NULL; Already zero. */
1189 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1191 /* Ordinarilly, we would get additional names for the loader from
1192 our DT_SONAME. This can't happen if we were actually linked as
1193 a static executable (detect this case when we have no DYNAMIC).
1194 If so, assume the filename component of the interpreter path to
1195 be our SONAME, and add it to our name list. */
1196 if (GL(dl_rtld_map
).l_ld
== NULL
)
1198 const char *p
= NULL
;
1199 const char *cp
= _dl_rtld_libname
.name
;
1201 /* Find the filename part of the path. */
1208 _dl_rtld_libname2
.name
= p
;
1209 /* _dl_rtld_libname2.next = NULL; Already zero. */
1210 _dl_rtld_libname
.next
= &_dl_rtld_libname2
;
1218 ElfW(Addr
) mapstart
;
1219 ElfW(Addr
) allocend
;
1221 /* Remember where the main program starts in memory. */
1222 mapstart
= (main_map
->l_addr
1223 + (ph
->p_vaddr
& ~(GLRO(dl_pagesize
) - 1)));
1224 if (main_map
->l_map_start
> mapstart
)
1225 main_map
->l_map_start
= mapstart
;
1227 /* Also where it ends. */
1228 allocend
= main_map
->l_addr
+ ph
->p_vaddr
+ ph
->p_memsz
;
1229 if (main_map
->l_map_end
< allocend
)
1230 main_map
->l_map_end
= allocend
;
1231 if ((ph
->p_flags
& PF_X
) && allocend
> main_map
->l_text_end
)
1232 main_map
->l_text_end
= allocend
;
1237 if (ph
->p_memsz
> 0)
1239 /* Note that in the case the dynamic linker we duplicate work
1240 here since we read the PT_TLS entry already in
1241 _dl_start_final. But the result is repeatable so do not
1242 check for this special but unimportant case. */
1243 main_map
->l_tls_blocksize
= ph
->p_memsz
;
1244 main_map
->l_tls_align
= ph
->p_align
;
1245 if (ph
->p_align
== 0)
1246 main_map
->l_tls_firstbyte_offset
= 0;
1248 main_map
->l_tls_firstbyte_offset
= (ph
->p_vaddr
1249 & (ph
->p_align
- 1));
1250 main_map
->l_tls_initimage_size
= ph
->p_filesz
;
1251 main_map
->l_tls_initimage
= (void *) ph
->p_vaddr
;
1253 /* This image gets the ID one. */
1254 GL(dl_tls_max_dtv_idx
) = main_map
->l_tls_modid
= 1;
1259 GL(dl_stack_flags
) = ph
->p_flags
;
1263 main_map
->l_relro_addr
= ph
->p_vaddr
;
1264 main_map
->l_relro_size
= ph
->p_memsz
;
1268 /* Adjust the address of the TLS initialization image in case
1269 the executable is actually an ET_DYN object. */
1270 if (main_map
->l_tls_initimage
!= NULL
)
1271 main_map
->l_tls_initimage
1272 = (char *) main_map
->l_tls_initimage
+ main_map
->l_addr
;
1273 if (! main_map
->l_map_end
)
1274 main_map
->l_map_end
= ~0;
1275 if (! main_map
->l_text_end
)
1276 main_map
->l_text_end
= ~0;
1277 if (! GL(dl_rtld_map
).l_libname
&& GL(dl_rtld_map
).l_name
)
1279 /* We were invoked directly, so the program might not have a
1281 _dl_rtld_libname
.name
= GL(dl_rtld_map
).l_name
;
1282 /* _dl_rtld_libname.next = NULL; Already zero. */
1283 GL(dl_rtld_map
).l_libname
= &_dl_rtld_libname
;
1286 assert (GL(dl_rtld_map
).l_libname
); /* How else did we get here? */
1288 /* If the current libname is different from the SONAME, add the
1290 if (GL(dl_rtld_map
).l_info
[DT_SONAME
] != NULL
1291 && strcmp (GL(dl_rtld_map
).l_libname
->name
,
1292 (const char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1293 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_val
) != 0)
1295 static struct libname_list newname
;
1296 newname
.name
= ((char *) D_PTR (&GL(dl_rtld_map
), l_info
[DT_STRTAB
])
1297 + GL(dl_rtld_map
).l_info
[DT_SONAME
]->d_un
.d_ptr
);
1298 newname
.next
= NULL
;
1299 newname
.dont_free
= 1;
1301 assert (GL(dl_rtld_map
).l_libname
->next
== NULL
);
1302 GL(dl_rtld_map
).l_libname
->next
= &newname
;
1304 /* The ld.so must be relocated since otherwise loading audit modules
1305 will fail since they reuse the very same ld.so. */
1306 assert (GL(dl_rtld_map
).l_relocated
);
1310 /* Extract the contents of the dynamic section for easy access. */
1311 elf_get_dynamic_info (main_map
, NULL
);
1312 /* Set up our cache of pointers into the hash table. */
1313 _dl_setup_hash (main_map
);
1316 if (__builtin_expect (mode
, normal
) == verify
)
1318 /* We were called just to verify that this is a dynamic
1319 executable using us as the program interpreter. Exit with an
1320 error if we were not able to load the binary or no interpreter
1321 is specified (i.e., this is no dynamically linked binary. */
1322 if (main_map
->l_ld
== NULL
)
1325 /* We allow here some platform specific code. */
1326 #ifdef DISTINGUISH_LIB_VERSIONS
1327 DISTINGUISH_LIB_VERSIONS
;
1329 _exit (has_interp
? 0 : 2);
1332 struct link_map
**first_preload
= &GL(dl_rtld_map
).l_next
;
1333 /* Set up the data structures for the system-supplied DSO early,
1334 so they can influence _dl_init_paths. */
1335 setup_vdso (main_map
, &first_preload
);
1337 #ifdef DL_SYSDEP_OSCHECK
1338 DL_SYSDEP_OSCHECK (_dl_fatal_printf
);
1341 /* Initialize the data structures for the search paths for shared
1343 _dl_init_paths (library_path
);
1345 /* Initialize _r_debug. */
1346 struct r_debug
*r
= _dl_debug_initialize (GL(dl_rtld_map
).l_addr
,
1348 r
->r_state
= RT_CONSISTENT
;
1350 /* Put the link_map for ourselves on the chain so it can be found by
1351 name. Note that at this point the global chain of link maps contains
1352 exactly one element, which is pointed to by dl_loaded. */
1353 if (! GL(dl_rtld_map
).l_name
)
1354 /* If not invoked directly, the dynamic linker shared object file was
1355 found by the PT_INTERP name. */
1356 GL(dl_rtld_map
).l_name
= (char *) GL(dl_rtld_map
).l_libname
->name
;
1357 GL(dl_rtld_map
).l_type
= lt_library
;
1358 main_map
->l_next
= &GL(dl_rtld_map
);
1359 GL(dl_rtld_map
).l_prev
= main_map
;
1360 ++GL(dl_ns
)[LM_ID_BASE
]._ns_nloaded
;
1363 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1364 to not using bias for non-prelinked PIEs and libraries
1365 and using it for executables or prelinked PIEs or libraries. */
1366 if (GLRO(dl_use_load_bias
) == (ElfW(Addr
)) -2)
1367 GLRO(dl_use_load_bias
) = main_map
->l_addr
== 0 ? -1 : 0;
1369 /* Set up the program header information for the dynamic linker
1370 itself. It is needed in the dl_iterate_phdr() callbacks. */
1371 ElfW(Ehdr
) *rtld_ehdr
= (ElfW(Ehdr
) *) GL(dl_rtld_map
).l_map_start
;
1372 ElfW(Phdr
) *rtld_phdr
= (ElfW(Phdr
) *) (GL(dl_rtld_map
).l_map_start
1373 + rtld_ehdr
->e_phoff
);
1374 GL(dl_rtld_map
).l_phdr
= rtld_phdr
;
1375 GL(dl_rtld_map
).l_phnum
= rtld_ehdr
->e_phnum
;
1378 /* PT_GNU_RELRO is usually the last phdr. */
1379 size_t cnt
= rtld_ehdr
->e_phnum
;
1381 if (rtld_phdr
[cnt
].p_type
== PT_GNU_RELRO
)
1383 GL(dl_rtld_map
).l_relro_addr
= rtld_phdr
[cnt
].p_vaddr
;
1384 GL(dl_rtld_map
).l_relro_size
= rtld_phdr
[cnt
].p_memsz
;
1388 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1389 if (GL(dl_rtld_map
).l_tls_blocksize
!= 0)
1390 /* Assign a module ID. Do this before loading any audit modules. */
1391 GL(dl_rtld_map
).l_tls_modid
= _dl_next_tls_modid ();
1393 /* If we have auditing DSOs to load, do it now. */
1394 if (__builtin_expect (audit_list
!= NULL
, 0))
1396 /* Iterate over all entries in the list. The order is important. */
1397 struct audit_ifaces
*last_audit
= NULL
;
1398 struct audit_list
*al
= audit_list
->next
;
1400 /* Since we start using the auditing DSOs right away we need to
1401 initialize the data structures now. */
1404 /* Initialize security features. We need to do it this early
1405 since otherwise the constructors of the audit libraries will
1406 use different values (especially the pointer guard) and will
1412 int tls_idx
= GL(dl_tls_max_dtv_idx
);
1414 /* Now it is time to determine the layout of the static TLS
1415 block and allocate it for the initial thread. Note that we
1416 always allocate the static block, we never defer it even if
1417 no DF_STATIC_TLS bit is set. The reason is that we know
1418 glibc will use the static model. */
1419 struct dlmopen_args dlmargs
;
1420 dlmargs
.fname
= al
->name
;
1423 const char *objname
;
1424 const char *err_str
= NULL
;
1426 (void) _dl_catch_error (&objname
, &err_str
, &malloced
, dlmopen_doit
,
1428 if (__builtin_expect (err_str
!= NULL
, 0))
1431 _dl_error_printf ("\
1432 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1435 free ((char *) err_str
);
1439 struct lookup_args largs
;
1440 largs
.name
= "la_version";
1441 largs
.map
= dlmargs
.map
;
1443 /* Check whether the interface version matches. */
1444 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1445 lookup_doit
, &largs
);
1447 unsigned int (*laversion
) (unsigned int);
1450 && (laversion
= largs
.result
) != NULL
1451 && (lav
= laversion (LAV_CURRENT
)) > 0
1452 && lav
<= LAV_CURRENT
)
1454 /* Allocate structure for the callback function pointers.
1455 This call can never fail. */
1458 struct audit_ifaces ifaces
;
1459 #define naudit_ifaces 8
1460 void (*fptr
[naudit_ifaces
]) (void);
1461 } *newp
= malloc (sizeof (*newp
));
1463 /* Names of the auditing interfaces. All in one
1465 static const char audit_iface_names
[] =
1470 #if __ELF_NATIVE_CLASS == 32
1472 #elif __ELF_NATIVE_CLASS == 64
1475 # error "__ELF_NATIVE_CLASS must be defined"
1477 #define STRING(s) __STRING (s)
1478 "la_" STRING (ARCH_LA_PLTENTER
) "\0"
1479 "la_" STRING (ARCH_LA_PLTEXIT
) "\0"
1481 unsigned int cnt
= 0;
1482 const char *cp
= audit_iface_names
;
1486 (void) _dl_catch_error (&objname
, &err_str
, &malloced
,
1487 lookup_doit
, &largs
);
1489 /* Store the pointer. */
1490 if (err_str
== NULL
&& largs
.result
!= NULL
)
1492 newp
->fptr
[cnt
] = largs
.result
;
1494 /* The dynamic linker link map is statically
1495 allocated, initialize the data now. */
1496 GL(dl_rtld_map
).l_audit
[cnt
].cookie
1497 = (intptr_t) &GL(dl_rtld_map
);
1500 newp
->fptr
[cnt
] = NULL
;
1503 cp
= (char *) rawmemchr (cp
, '\0') + 1;
1505 while (*cp
!= '\0');
1506 assert (cnt
== naudit_ifaces
);
1508 /* Now append the new auditing interface to the list. */
1509 newp
->ifaces
.next
= NULL
;
1510 if (last_audit
== NULL
)
1511 last_audit
= GLRO(dl_audit
) = &newp
->ifaces
;
1513 last_audit
= last_audit
->next
= &newp
->ifaces
;
1516 /* Mark the DSO as being used for auditing. */
1517 dlmargs
.map
->l_auditing
= 1;
1521 /* We cannot use the DSO, it does not have the
1522 appropriate interfaces or it expects something
1525 Lmid_t ns
= dlmargs
.map
->l_ns
;
1527 _dl_close (dlmargs
.map
);
1529 /* Make sure the namespace has been cleared entirely. */
1530 assert (GL(dl_ns
)[ns
]._ns_loaded
== NULL
);
1531 assert (GL(dl_ns
)[ns
]._ns_nloaded
== 0);
1533 GL(dl_tls_max_dtv_idx
) = tls_idx
;
1540 while (al
!= audit_list
->next
);
1542 /* If we have any auditing modules, announce that we already
1543 have two objects loaded. */
1544 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
1546 struct link_map
*ls
[2] = { main_map
, &GL(dl_rtld_map
) };
1548 for (unsigned int outer
= 0; outer
< 2; ++outer
)
1550 struct audit_ifaces
*afct
= GLRO(dl_audit
);
1551 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
1553 if (afct
->objopen
!= NULL
)
1555 ls
[outer
]->l_audit
[cnt
].bindflags
1556 = afct
->objopen (ls
[outer
], LM_ID_BASE
,
1557 &ls
[outer
]->l_audit
[cnt
].cookie
);
1559 ls
[outer
]->l_audit_any_plt
1560 |= ls
[outer
]->l_audit
[cnt
].bindflags
!= 0;
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 (__builtin_expect (GLRO(dl_naudit
) > 0, 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 (__builtin_expect (preloadlist
!= NULL
, 0))
1614 /* The LD_PRELOAD environment variable gives list of libraries
1615 separated by white space or colons that are loaded before the
1616 executable's dependencies and prepended to the global scope
1617 list. If the binary is running setuid all elements
1618 containing a '/' are ignored since it is insecure. */
1619 char *list
= strdupa (preloadlist
);
1622 HP_TIMING_NOW (start
);
1624 /* Prevent optimizing strsep. Speed is not important here. */
1625 while ((p
= (strsep
) (&list
, " :")) != NULL
)
1627 && (__builtin_expect (! INTUSE(__libc_enable_secure
), 1)
1628 || strchr (p
, '/') == NULL
))
1629 npreloads
+= do_preload (p
, main_map
, "LD_PRELOAD");
1631 HP_TIMING_NOW (stop
);
1632 HP_TIMING_DIFF (diff
, start
, stop
);
1633 HP_TIMING_ACCUM_NT (load_time
, diff
);
1636 /* There usually is no ld.so.preload file, it should only be used
1637 for emergencies and testing. So the open call etc should usually
1638 fail. Using access() on a non-existing file is faster than using
1639 open(). So we do this first. If it succeeds we do almost twice
1640 the work but this does not matter, since it is not for production
1642 static const char preload_file
[] = "/etc/ld.so.preload";
1643 if (__builtin_expect (__access (preload_file
, R_OK
) == 0, 0))
1645 /* Read the contents of the file. */
1646 file
= _dl_sysdep_read_whole_file (preload_file
, &file_size
,
1647 PROT_READ
| PROT_WRITE
);
1648 if (__builtin_expect (file
!= MAP_FAILED
, 0))
1650 /* Parse the file. It contains names of libraries to be loaded,
1651 separated by white spaces or `:'. It may also contain
1652 comments introduced by `#'. */
1657 /* Eliminate comments. */
1662 char *comment
= memchr (runp
, '#', rest
);
1663 if (comment
== NULL
)
1666 rest
-= comment
- runp
;
1669 while (--rest
> 0 && *++comment
!= '\n');
1672 /* We have one problematic case: if we have a name at the end of
1673 the file without a trailing terminating characters, we cannot
1674 place the \0. Handle the case separately. */
1675 if (file
[file_size
- 1] != ' ' && file
[file_size
- 1] != '\t'
1676 && file
[file_size
- 1] != '\n' && file
[file_size
- 1] != ':')
1678 problem
= &file
[file_size
];
1679 while (problem
> file
&& problem
[-1] != ' '
1680 && problem
[-1] != '\t'
1681 && problem
[-1] != '\n' && problem
[-1] != ':')
1690 file
[file_size
- 1] = '\0';
1693 HP_TIMING_NOW (start
);
1695 if (file
!= problem
)
1699 while ((p
= strsep (&runp
, ": \t\n")) != NULL
)
1701 npreloads
+= do_preload (p
, main_map
, preload_file
);
1704 if (problem
!= NULL
)
1706 char *p
= strndupa (problem
, file_size
- (problem
- file
));
1708 npreloads
+= do_preload (p
, main_map
, preload_file
);
1711 HP_TIMING_NOW (stop
);
1712 HP_TIMING_DIFF (diff
, start
, stop
);
1713 HP_TIMING_ACCUM_NT (load_time
, diff
);
1715 /* We don't need the file anymore. */
1716 __munmap (file
, file_size
);
1720 if (__builtin_expect (*first_preload
!= NULL
, 0))
1722 /* Set up PRELOADS with a vector of the preloaded libraries. */
1723 struct link_map
*l
= *first_preload
;
1724 preloads
= __alloca (npreloads
* sizeof preloads
[0]);
1731 assert (i
== npreloads
);
1734 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1735 specified some libraries to load, these are inserted before the actual
1736 dependencies in the executable's searchlist for symbol resolution. */
1737 HP_TIMING_NOW (start
);
1738 _dl_map_object_deps (main_map
, preloads
, npreloads
, mode
== trace
, 0);
1739 HP_TIMING_NOW (stop
);
1740 HP_TIMING_DIFF (diff
, start
, stop
);
1741 HP_TIMING_ACCUM_NT (load_time
, diff
);
1743 /* Mark all objects as being in the global scope. */
1744 for (i
= main_map
->l_searchlist
.r_nlist
; i
> 0; )
1745 main_map
->l_searchlist
.r_list
[--i
]->l_global
= 1;
1747 /* Remove _dl_rtld_map from the chain. */
1748 GL(dl_rtld_map
).l_prev
->l_next
= GL(dl_rtld_map
).l_next
;
1749 if (GL(dl_rtld_map
).l_next
!= NULL
)
1750 GL(dl_rtld_map
).l_next
->l_prev
= GL(dl_rtld_map
).l_prev
;
1752 for (i
= 1; i
< main_map
->l_searchlist
.r_nlist
; ++i
)
1753 if (main_map
->l_searchlist
.r_list
[i
] == &GL(dl_rtld_map
))
1756 bool rtld_multiple_ref
= false;
1757 if (__builtin_expect (i
< main_map
->l_searchlist
.r_nlist
, 1))
1759 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1760 put it back in the list of visible objects. We insert it into the
1761 chain in symbol search order because gdb uses the chain's order as
1762 its symbol search order. */
1763 rtld_multiple_ref
= true;
1765 GL(dl_rtld_map
).l_prev
= main_map
->l_searchlist
.r_list
[i
- 1];
1766 if (__builtin_expect (mode
, normal
) == normal
)
1768 GL(dl_rtld_map
).l_next
= (i
+ 1 < main_map
->l_searchlist
.r_nlist
1769 ? main_map
->l_searchlist
.r_list
[i
+ 1]
1771 #ifdef NEED_DL_SYSINFO_DSO
1772 if (GLRO(dl_sysinfo_map
) != NULL
1773 && GL(dl_rtld_map
).l_prev
->l_next
== GLRO(dl_sysinfo_map
)
1774 && GL(dl_rtld_map
).l_next
!= GLRO(dl_sysinfo_map
))
1775 GL(dl_rtld_map
).l_prev
= GLRO(dl_sysinfo_map
);
1779 /* In trace mode there might be an invisible object (which we
1780 could not find) after the previous one in the search list.
1781 In this case it doesn't matter much where we put the
1782 interpreter object, so we just initialize the list pointer so
1783 that the assertion below holds. */
1784 GL(dl_rtld_map
).l_next
= GL(dl_rtld_map
).l_prev
->l_next
;
1786 assert (GL(dl_rtld_map
).l_prev
->l_next
== GL(dl_rtld_map
).l_next
);
1787 GL(dl_rtld_map
).l_prev
->l_next
= &GL(dl_rtld_map
);
1788 if (GL(dl_rtld_map
).l_next
!= NULL
)
1790 assert (GL(dl_rtld_map
).l_next
->l_prev
== GL(dl_rtld_map
).l_prev
);
1791 GL(dl_rtld_map
).l_next
->l_prev
= &GL(dl_rtld_map
);
1795 /* Now let us see whether all libraries are available in the
1796 versions we need. */
1798 struct version_check_args args
;
1799 args
.doexit
= mode
== normal
;
1800 args
.dotrace
= mode
== trace
;
1801 _dl_receive_error (print_missing_version
, version_check_doit
, &args
);
1804 /* We do not initialize any of the TLS functionality unless any of the
1805 initial modules uses TLS. This makes dynamic loading of modules with
1806 TLS impossible, but to support it requires either eagerly doing setup
1807 now or lazily doing it later. Doing it now makes us incompatible with
1808 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1809 used. Trying to do it lazily is too hairy to try when there could be
1810 multiple threads (from a non-TLS-using libpthread). */
1811 bool was_tls_init_tp_called
= tls_init_tp_called
;
1815 if (__builtin_expect (audit_list
== NULL
, 1))
1816 /* Initialize security features. But only if we have not done it
1820 if (__builtin_expect (mode
, normal
) != normal
)
1822 /* We were run just to list the shared libraries. It is
1823 important that we do this before real relocation, because the
1824 functions we call below for output may no longer work properly
1825 after relocation. */
1828 if (GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1830 struct r_scope_elem
*scope
= &main_map
->l_searchlist
;
1832 for (i
= 0; i
< scope
->r_nlist
; i
++)
1834 l
= scope
->r_list
[i
];
1837 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1840 if (_dl_name_match_p (GLRO(dl_trace_prelink
), l
))
1841 GLRO(dl_trace_prelink_map
) = l
;
1842 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1843 DSO_FILENAME (l
->l_libname
->name
),
1844 DSO_FILENAME (l
->l_name
),
1845 (int) sizeof l
->l_map_start
* 2,
1846 (size_t) l
->l_map_start
,
1847 (int) sizeof l
->l_addr
* 2,
1848 (size_t) l
->l_addr
);
1851 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l
->l_tls_modid
,
1852 (int) sizeof l
->l_tls_offset
* 2,
1853 (size_t) l
->l_tls_offset
);
1858 else if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
1860 /* Look through the dependencies of the main executable
1861 and determine which of them is not actually
1863 struct link_map
*l
= main_map
;
1865 /* Relocate the main executable. */
1866 struct relocate_args args
= { .l
= l
,
1867 .reloc_mode
= ((GLRO(dl_lazy
)
1869 | __RTLD_NOIFUNC
) };
1870 _dl_receive_error (print_unresolved
, relocate_doit
, &args
);
1872 /* This loop depends on the dependencies of the executable to
1873 correspond in number and order to the DT_NEEDED entries. */
1874 ElfW(Dyn
) *dyn
= main_map
->l_ld
;
1876 while (dyn
->d_tag
!= DT_NULL
)
1878 if (dyn
->d_tag
== DT_NEEDED
)
1881 #ifdef NEED_DL_SYSINFO_DSO
1882 /* Skip the VDSO since it's not part of the list
1883 of objects we brought in via DT_NEEDED entries. */
1884 if (l
== GLRO(dl_sysinfo_map
))
1891 _dl_printf ("Unused direct dependencies:\n");
1895 _dl_printf ("\t%s\n", l
->l_name
);
1902 _exit (first
!= true);
1904 else if (! main_map
->l_info
[DT_NEEDED
])
1905 _dl_printf ("\tstatically linked\n");
1908 for (l
= main_map
->l_next
; l
; l
= l
->l_next
)
1910 /* The library was not found. */
1911 _dl_printf ("\t%s => not found\n", l
->l_libname
->name
);
1912 else if (strcmp (l
->l_libname
->name
, l
->l_name
) == 0)
1913 _dl_printf ("\t%s (0x%0*Zx)\n", l
->l_libname
->name
,
1914 (int) sizeof l
->l_map_start
* 2,
1915 (size_t) l
->l_map_start
);
1917 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l
->l_libname
->name
,
1918 l
->l_name
, (int) sizeof l
->l_map_start
* 2,
1919 (size_t) l
->l_map_start
);
1922 if (__builtin_expect (mode
, trace
) != trace
)
1923 for (i
= 1; i
< (unsigned int) _dl_argc
; ++i
)
1925 const ElfW(Sym
) *ref
= NULL
;
1926 ElfW(Addr
) loadbase
;
1929 result
= _dl_lookup_symbol_x (INTUSE(_dl_argv
)[i
], main_map
,
1930 &ref
, main_map
->l_scope
,
1931 NULL
, ELF_RTYPE_CLASS_PLT
,
1932 DL_LOOKUP_ADD_DEPENDENCY
, NULL
);
1934 loadbase
= LOOKUP_VALUE_ADDRESS (result
);
1936 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1937 INTUSE(_dl_argv
)[i
],
1938 (int) sizeof ref
->st_value
* 2,
1939 (size_t) ref
->st_value
,
1940 (int) sizeof loadbase
* 2, (size_t) loadbase
);
1944 /* If LD_WARN is set, warn about undefined symbols. */
1945 if (GLRO(dl_lazy
) >= 0 && GLRO(dl_verbose
))
1947 /* We have to do symbol dependency testing. */
1948 struct relocate_args args
;
1951 args
.reloc_mode
= ((GLRO(dl_lazy
) ? RTLD_LAZY
: 0)
1954 i
= main_map
->l_searchlist
.r_nlist
;
1957 struct link_map
*l
= main_map
->l_initfini
[i
];
1958 if (l
!= &GL(dl_rtld_map
) && ! l
->l_faked
)
1961 _dl_receive_error (print_unresolved
, relocate_doit
,
1966 if ((GLRO(dl_debug_mask
) & DL_DEBUG_PRELINK
)
1967 && rtld_multiple_ref
)
1969 /* Mark the link map as not yet relocated again. */
1970 GL(dl_rtld_map
).l_relocated
= 0;
1971 _dl_relocate_object (&GL(dl_rtld_map
),
1972 main_map
->l_scope
, __RTLD_NOIFUNC
, 0);
1975 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
1978 /* Print more information. This means here, print information
1979 about the versions needed. */
1981 struct link_map
*map
;
1983 for (map
= main_map
; map
!= NULL
; map
= map
->l_next
)
1986 ElfW(Dyn
) *dyn
= map
->l_info
[VERNEEDTAG
];
1992 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
1993 ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
1997 _dl_printf ("\n\tVersion information:\n");
2001 _dl_printf ("\t%s:\n", DSO_FILENAME (map
->l_name
));
2006 struct link_map
*needed
;
2008 needed
= find_needed (strtab
+ ent
->vn_file
);
2009 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
2013 const char *fname
= NULL
;
2016 && match_version (strtab
+ aux
->vna_name
,
2018 fname
= needed
->l_name
;
2020 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2021 strtab
+ ent
->vn_file
,
2022 strtab
+ aux
->vna_name
,
2023 aux
->vna_flags
& VER_FLG_WEAK
2025 fname
?: "not found");
2027 if (aux
->vna_next
== 0)
2028 /* No more symbols. */
2032 aux
= (ElfW(Vernaux
) *) ((char *) aux
2036 if (ent
->vn_next
== 0)
2037 /* No more dependencies. */
2040 /* Next dependency. */
2041 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
2050 if (main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]
2051 && ! __builtin_expect (GLRO(dl_profile
) != NULL
, 0)
2052 && ! __builtin_expect (GLRO(dl_dynamic_weak
), 0))
2054 ElfW(Lib
) *liblist
, *liblistend
;
2055 struct link_map
**r_list
, **r_listend
, *l
;
2056 const char *strtab
= (const void *) D_PTR (main_map
, l_info
[DT_STRTAB
]);
2058 assert (main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)] != NULL
);
2059 liblist
= (ElfW(Lib
) *)
2060 main_map
->l_info
[ADDRIDX (DT_GNU_LIBLIST
)]->d_un
.d_ptr
;
2061 liblistend
= (ElfW(Lib
) *)
2063 main_map
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)]->d_un
.d_val
);
2064 r_list
= main_map
->l_searchlist
.r_list
;
2065 r_listend
= r_list
+ main_map
->l_searchlist
.r_nlist
;
2067 for (; r_list
< r_listend
&& liblist
< liblistend
; r_list
++)
2074 /* If the library is not mapped where it should, fail. */
2078 /* Next, check if checksum matches. */
2079 if (l
->l_info
[VALIDX(DT_CHECKSUM
)] == NULL
2080 || l
->l_info
[VALIDX(DT_CHECKSUM
)]->d_un
.d_val
2081 != liblist
->l_checksum
)
2084 if (l
->l_info
[VALIDX(DT_GNU_PRELINKED
)] == NULL
2085 || l
->l_info
[VALIDX(DT_GNU_PRELINKED
)]->d_un
.d_val
2086 != liblist
->l_time_stamp
)
2089 if (! _dl_name_match_p (strtab
+ liblist
->l_name
, l
))
2096 if (r_list
== r_listend
&& liblist
== liblistend
)
2099 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_LIBS
, 0))
2100 _dl_debug_printf ("\nprelink checking: %s\n",
2101 prelinked
? "ok" : "failed");
2105 /* Now set up the variable which helps the assembler startup code. */
2106 GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
= &main_map
->l_searchlist
;
2108 /* Save the information about the original global scope list since
2109 we need it in the memory handling later. */
2110 GLRO(dl_initial_searchlist
) = *GL(dl_ns
)[LM_ID_BASE
]._ns_main_searchlist
;
2112 /* Remember the last search directory added at startup, now that
2113 malloc will no longer be the one from dl-minimal.c. */
2114 GLRO(dl_init_all_dirs
) = GL(dl_all_dirs
);
2116 /* Print scope information. */
2117 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_SCOPES
, 0))
2119 _dl_debug_printf ("\nInitial object scopes\n");
2121 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2122 _dl_show_scope (l
, 0);
2127 if (main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)] != NULL
)
2129 ElfW(Rela
) *conflict
, *conflictend
;
2130 #ifndef HP_TIMING_NONAVAIL
2135 HP_TIMING_NOW (start
);
2136 assert (main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)] != NULL
);
2137 conflict
= (ElfW(Rela
) *)
2138 main_map
->l_info
[ADDRIDX (DT_GNU_CONFLICT
)]->d_un
.d_ptr
;
2139 conflictend
= (ElfW(Rela
) *)
2141 + main_map
->l_info
[VALIDX (DT_GNU_CONFLICTSZ
)]->d_un
.d_val
);
2142 _dl_resolve_conflicts (main_map
, conflict
, conflictend
);
2143 HP_TIMING_NOW (stop
);
2144 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2148 /* Mark all the objects so we know they have been already relocated. */
2149 for (struct link_map
*l
= main_map
; l
!= NULL
; l
= l
->l_next
)
2152 if (l
->l_relro_size
)
2153 _dl_protect_relro (l
);
2155 /* Add object to slot information data if necessasy. */
2156 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2157 _dl_add_to_slotinfo (l
);
2162 /* Now we have all the objects loaded. Relocate them all except for
2163 the dynamic linker itself. We do this in reverse order so that copy
2164 relocs of earlier objects overwrite the data written by later
2165 objects. We do not re-relocate the dynamic linker itself in this
2166 loop because that could result in the GOT entries for functions we
2167 call being changed, and that would break us. It is safe to relocate
2168 the dynamic linker out of order because it has no copy relocs (we
2169 know that because it is self-contained). */
2171 int consider_profiling
= GLRO(dl_profile
) != NULL
;
2172 #ifndef HP_TIMING_NONAVAIL
2177 /* If we are profiling we also must do lazy reloaction. */
2178 GLRO(dl_lazy
) |= consider_profiling
;
2180 HP_TIMING_NOW (start
);
2181 unsigned i
= main_map
->l_searchlist
.r_nlist
;
2184 struct link_map
*l
= main_map
->l_initfini
[i
];
2186 /* While we are at it, help the memory handling a bit. We have to
2187 mark some data structures as allocated with the fake malloc()
2188 implementation in ld.so. */
2189 struct libname_list
*lnp
= l
->l_libname
->next
;
2191 while (__builtin_expect (lnp
!= NULL
, 0))
2196 /* Also allocated with the fake malloc(). */
2197 l
->l_free_initfini
= 0;
2199 if (l
!= &GL(dl_rtld_map
))
2200 _dl_relocate_object (l
, l
->l_scope
, GLRO(dl_lazy
) ? RTLD_LAZY
: 0,
2201 consider_profiling
);
2203 /* Add object to slot information data if necessasy. */
2204 if (l
->l_tls_blocksize
!= 0 && tls_init_tp_called
)
2205 _dl_add_to_slotinfo (l
);
2207 HP_TIMING_NOW (stop
);
2209 HP_TIMING_DIFF (relocate_time
, start
, stop
);
2211 /* Now enable profiling if needed. Like the previous call,
2212 this has to go here because the calls it makes should use the
2213 rtld versions of the functions (particularly calloc()), but it
2214 needs to have _dl_profile_map set up by the relocator. */
2215 if (__builtin_expect (GL(dl_profile_map
) != NULL
, 0))
2216 /* We must prepare the profiling. */
2217 _dl_start_profile ();
2220 #ifndef NONTLS_INIT_TP
2221 # define NONTLS_INIT_TP do { } while (0)
2224 if (!was_tls_init_tp_called
&& GL(dl_tls_max_dtv_idx
) > 0)
2225 ++GL(dl_tls_generation
);
2227 /* Now that we have completed relocation, the initializer data
2228 for the TLS blocks has its final values and we can copy them
2229 into the main thread's TLS area, which we allocated above. */
2230 _dl_allocate_tls_init (tcbp
);
2232 /* And finally install it for the main thread. If ld.so itself uses
2233 TLS we know the thread pointer was initialized earlier. */
2234 if (! tls_init_tp_called
)
2238 = TLS_INIT_TP (tcbp
, USE___THREAD
);
2240 = TLS_INIT_TP (tcbp
, 0);
2242 if (__builtin_expect (lossage
!= NULL
, 0))
2243 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2247 /* Make sure no new search directories have been added. */
2248 assert (GLRO(dl_init_all_dirs
) == GL(dl_all_dirs
));
2250 if (! prelinked
&& rtld_multiple_ref
)
2252 /* There was an explicit ref to the dynamic linker as a shared lib.
2253 Re-relocate ourselves with user-controlled symbol definitions.
2255 We must do this after TLS initialization in case after this
2256 re-relocation, we might call a user-supplied function
2257 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2259 #ifndef HP_TIMING_NONAVAIL
2265 HP_TIMING_NOW (start
);
2266 /* Mark the link map as not yet relocated again. */
2267 GL(dl_rtld_map
).l_relocated
= 0;
2268 _dl_relocate_object (&GL(dl_rtld_map
), main_map
->l_scope
, 0, 0);
2269 HP_TIMING_NOW (stop
);
2270 HP_TIMING_DIFF (add
, start
, stop
);
2271 HP_TIMING_ACCUM_NT (relocate_time
, add
);
2274 /* Do any necessary cleanups for the startup OS interface code.
2275 We do these now so that no calls are made after rtld re-relocation
2276 which might be resolved to different functions than we expect.
2277 We cannot do this before relocating the other objects because
2278 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2279 _dl_sysdep_start_cleanup ();
2282 /* Auditing checkpoint: we have added all objects. */
2283 if (__builtin_expect (GLRO(dl_naudit
) > 0, 0))
2285 struct link_map
*head
= GL(dl_ns
)[LM_ID_BASE
]._ns_loaded
;
2286 /* Do not call the functions for any auditing object. */
2287 if (head
->l_auditing
== 0)
2289 struct audit_ifaces
*afct
= GLRO(dl_audit
);
2290 for (unsigned int cnt
= 0; cnt
< GLRO(dl_naudit
); ++cnt
)
2292 if (afct
->activity
!= NULL
)
2293 afct
->activity (&head
->l_audit
[cnt
].cookie
, LA_ACT_CONSISTENT
);
2301 /* Notify the debugger all new objects are now ready to go. We must re-get
2302 the address since by now the variable might be in another object. */
2303 r
= _dl_debug_initialize (0, LM_ID_BASE
);
2304 r
->r_state
= RT_CONSISTENT
;
2306 LIBC_PROBE (init_complete
, 2, LM_ID_BASE
, r
);
2308 #if defined USE_LDCONFIG && !defined MAP_COPY
2309 /* We must munmap() the cache file. */
2310 _dl_unload_cache ();
2313 /* Once we return, _dl_sysdep_start will invoke
2314 the DT_INIT functions and then *USER_ENTRY. */
2317 /* This is a little helper function for resolving symbols while
2318 tracing the binary. */
2320 print_unresolved (int errcode
__attribute__ ((unused
)), const char *objname
,
2321 const char *errstring
)
2323 if (objname
[0] == '\0')
2324 objname
= RTLD_PROGNAME
;
2325 _dl_error_printf ("%s (%s)\n", errstring
, objname
);
2328 /* This is a little helper function for resolving symbols while
2329 tracing the binary. */
2331 print_missing_version (int errcode
__attribute__ ((unused
)),
2332 const char *objname
, const char *errstring
)
2334 _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME
,
2335 objname
, errstring
);
2338 /* Nonzero if any of the debugging options is enabled. */
2339 static int any_debug attribute_relro
;
2341 /* Process the string given as the parameter which explains which debugging
2342 options are enabled. */
2344 process_dl_debug (const char *dl_debug
)
2346 /* When adding new entries make sure that the maximal length of a name
2347 is correctly handled in the LD_DEBUG_HELP code below. */
2351 const char name
[10];
2352 const char helptext
[41];
2353 unsigned short int mask
;
2356 #define LEN_AND_STR(str) sizeof (str) - 1, str
2357 { LEN_AND_STR ("libs"), "display library search paths",
2358 DL_DEBUG_LIBS
| DL_DEBUG_IMPCALLS
},
2359 { LEN_AND_STR ("reloc"), "display relocation processing",
2360 DL_DEBUG_RELOC
| DL_DEBUG_IMPCALLS
},
2361 { LEN_AND_STR ("files"), "display progress for input file",
2362 DL_DEBUG_FILES
| DL_DEBUG_IMPCALLS
},
2363 { LEN_AND_STR ("symbols"), "display symbol table processing",
2364 DL_DEBUG_SYMBOLS
| DL_DEBUG_IMPCALLS
},
2365 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2366 DL_DEBUG_BINDINGS
| DL_DEBUG_IMPCALLS
},
2367 { LEN_AND_STR ("versions"), "display version dependencies",
2368 DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
},
2369 { LEN_AND_STR ("scopes"), "display scope information",
2371 { LEN_AND_STR ("all"), "all previous options combined",
2372 DL_DEBUG_LIBS
| DL_DEBUG_RELOC
| DL_DEBUG_FILES
| DL_DEBUG_SYMBOLS
2373 | DL_DEBUG_BINDINGS
| DL_DEBUG_VERSIONS
| DL_DEBUG_IMPCALLS
2374 | DL_DEBUG_SCOPES
},
2375 { LEN_AND_STR ("statistics"), "display relocation statistics",
2376 DL_DEBUG_STATISTICS
},
2377 { LEN_AND_STR ("unused"), "determined unused DSOs",
2379 { LEN_AND_STR ("help"), "display this help message and exit",
2382 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2384 /* Skip separating white spaces and commas. */
2385 while (*dl_debug
!= '\0')
2387 if (*dl_debug
!= ' ' && *dl_debug
!= ',' && *dl_debug
!= ':')
2392 while (dl_debug
[len
] != '\0' && dl_debug
[len
] != ' '
2393 && dl_debug
[len
] != ',' && dl_debug
[len
] != ':')
2396 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2397 if (debopts
[cnt
].len
== len
2398 && memcmp (dl_debug
, debopts
[cnt
].name
, len
) == 0)
2400 GLRO(dl_debug_mask
) |= debopts
[cnt
].mask
;
2405 if (cnt
== ndebopts
)
2407 /* Display a warning and skip everything until next
2409 char *copy
= strndupa (dl_debug
, len
);
2410 _dl_error_printf ("\
2411 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy
);
2421 if (GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
)
2423 /* In order to get an accurate picture of whether a particular
2424 DT_NEEDED entry is actually used we have to process both
2425 the PLT and non-PLT relocation entries. */
2429 if (GLRO(dl_debug_mask
) & DL_DEBUG_HELP
)
2434 Valid options for the LD_DEBUG environment variable are:\n\n");
2436 for (cnt
= 0; cnt
< ndebopts
; ++cnt
)
2437 _dl_printf (" %.*s%s%s\n", debopts
[cnt
].len
, debopts
[cnt
].name
,
2438 " " + debopts
[cnt
].len
- 3,
2439 debopts
[cnt
].helptext
);
2442 To direct the debugging output into a file instead of standard output\n\
2443 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2449 process_dl_audit (char *str
)
2451 /* The parameter is a colon separated list of DSO names. */
2454 while ((p
= (strsep
) (&str
, ":")) != NULL
)
2456 && (__builtin_expect (! INTUSE(__libc_enable_secure
), 1)
2457 || strchr (p
, '/') == NULL
))
2459 /* This is using the local malloc, not the system malloc. The
2460 memory can never be freed. */
2461 struct audit_list
*newp
= malloc (sizeof (*newp
));
2464 if (audit_list
== NULL
)
2465 audit_list
= newp
->next
= newp
;
2468 newp
->next
= audit_list
->next
;
2469 audit_list
= audit_list
->next
= newp
;
2474 /* Process all environments variables the dynamic linker must recognize.
2475 Since all of them start with `LD_' we are a bit smarter while finding
2477 extern char **_environ attribute_hidden
;
2481 process_envvars (enum mode
*modep
)
2483 char **runp
= _environ
;
2485 enum mode mode
= normal
;
2486 char *debug_output
= NULL
;
2488 /* This is the default place for profiling data file. */
2489 GLRO(dl_profile_output
)
2490 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure
) ? 9 : 0];
2492 while ((envline
= _dl_next_ld_env_entry (&runp
)) != NULL
)
2496 while (envline
[len
] != '\0' && envline
[len
] != '=')
2499 if (envline
[len
] != '=')
2500 /* This is a "LD_" variable at the end of the string without
2501 a '=' character. Ignore it since otherwise we will access
2502 invalid memory below. */
2508 /* Warning level, verbose or not. */
2509 if (memcmp (envline
, "WARN", 4) == 0)
2510 GLRO(dl_verbose
) = envline
[5] != '\0';
2514 /* Debugging of the dynamic linker? */
2515 if (memcmp (envline
, "DEBUG", 5) == 0)
2517 process_dl_debug (&envline
[6]);
2520 if (memcmp (envline
, "AUDIT", 5) == 0)
2521 process_dl_audit (&envline
[6]);
2525 /* Print information about versions. */
2526 if (memcmp (envline
, "VERBOSE", 7) == 0)
2528 version_info
= envline
[8] != '\0';
2532 /* List of objects to be preloaded. */
2533 if (memcmp (envline
, "PRELOAD", 7) == 0)
2535 preloadlist
= &envline
[8];
2539 /* Which shared object shall be profiled. */
2540 if (memcmp (envline
, "PROFILE", 7) == 0 && envline
[8] != '\0')
2541 GLRO(dl_profile
) = &envline
[8];
2545 /* Do we bind early? */
2546 if (memcmp (envline
, "BIND_NOW", 8) == 0)
2548 GLRO(dl_lazy
) = envline
[9] == '\0';
2551 if (memcmp (envline
, "BIND_NOT", 8) == 0)
2552 GLRO(dl_bind_not
) = envline
[9] != '\0';
2556 /* Test whether we want to see the content of the auxiliary
2557 array passed up from the kernel. */
2558 if (!INTUSE(__libc_enable_secure
)
2559 && memcmp (envline
, "SHOW_AUXV", 9) == 0)
2564 /* Mask for the important hardware capabilities. */
2565 if (memcmp (envline
, "HWCAP_MASK", 10) == 0)
2566 GLRO(dl_hwcap_mask
) = __strtoul_internal (&envline
[11], NULL
,
2571 /* Path where the binary is found. */
2572 if (!INTUSE(__libc_enable_secure
)
2573 && memcmp (envline
, "ORIGIN_PATH", 11) == 0)
2574 GLRO(dl_origin_path
) = &envline
[12];
2578 /* The library search path. */
2579 if (memcmp (envline
, "LIBRARY_PATH", 12) == 0)
2581 library_path
= &envline
[13];
2585 /* Where to place the profiling data file. */
2586 if (memcmp (envline
, "DEBUG_OUTPUT", 12) == 0)
2588 debug_output
= &envline
[13];
2592 if (!INTUSE(__libc_enable_secure
)
2593 && memcmp (envline
, "DYNAMIC_WEAK", 12) == 0)
2594 GLRO(dl_dynamic_weak
) = 1;
2598 /* We might have some extra environment variable with length 13
2600 #ifdef EXTRA_LD_ENVVARS_13
2603 if (!INTUSE(__libc_enable_secure
)
2604 && memcmp (envline
, "USE_LOAD_BIAS", 13) == 0)
2606 GLRO(dl_use_load_bias
) = envline
[14] == '1' ? -1 : 0;
2610 if (memcmp (envline
, "POINTER_GUARD", 13) == 0)
2611 GLRO(dl_pointer_guard
) = envline
[14] != '0';
2615 /* Where to place the profiling data file. */
2616 if (!INTUSE(__libc_enable_secure
)
2617 && memcmp (envline
, "PROFILE_OUTPUT", 14) == 0
2618 && envline
[15] != '\0')
2619 GLRO(dl_profile_output
) = &envline
[15];
2623 /* The mode of the dynamic linker can be set. */
2624 if (memcmp (envline
, "TRACE_PRELINKING", 16) == 0)
2627 GLRO(dl_verbose
) = 1;
2628 GLRO(dl_debug_mask
) |= DL_DEBUG_PRELINK
;
2629 GLRO(dl_trace_prelink
) = &envline
[17];
2634 /* The mode of the dynamic linker can be set. */
2635 if (memcmp (envline
, "TRACE_LOADED_OBJECTS", 20) == 0)
2639 /* We might have some extra environment variable to handle. This
2640 is tricky due to the pre-processing of the length of the name
2641 in the switch statement here. The code here assumes that added
2642 environment variables have a different length. */
2643 #ifdef EXTRA_LD_ENVVARS
2649 /* The caller wants this information. */
2652 /* Extra security for SUID binaries. Remove all dangerous environment
2654 if (__builtin_expect (INTUSE(__libc_enable_secure
), 0))
2656 static const char unsecure_envvars
[] =
2657 #ifdef EXTRA_UNSECURE_ENVVARS
2658 EXTRA_UNSECURE_ENVVARS
2663 nextp
= unsecure_envvars
;
2667 /* We could use rawmemchr but this need not be fast. */
2668 nextp
= (char *) (strchr
) (nextp
, '\0') + 1;
2670 while (*nextp
!= '\0');
2672 if (__access ("/etc/suid-debug", F_OK
) != 0)
2674 unsetenv ("MALLOC_CHECK_");
2675 GLRO(dl_debug_mask
) = 0;
2681 /* If we have to run the dynamic linker in debugging mode and the
2682 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2683 messages to this file. */
2684 else if (any_debug
&& debug_output
!= NULL
)
2687 const int flags
= O_WRONLY
| O_APPEND
| O_CREAT
| O_NOFOLLOW
;
2689 const int flags
= O_WRONLY
| O_APPEND
| O_CREAT
;
2691 size_t name_len
= strlen (debug_output
);
2692 char buf
[name_len
+ 12];
2695 buf
[name_len
+ 11] = '\0';
2696 startp
= _itoa (__getpid (), &buf
[name_len
+ 11], 10, 0);
2698 startp
= memcpy (startp
- name_len
, debug_output
, name_len
);
2700 GLRO(dl_debug_fd
) = __open (startp
, flags
, DEFFILEMODE
);
2701 if (GLRO(dl_debug_fd
) == -1)
2702 /* We use standard output if opening the file failed. */
2703 GLRO(dl_debug_fd
) = STDOUT_FILENO
;
2708 /* Print the various times we collected. */
2710 __attribute ((noinline
))
2711 print_statistics (hp_timing_t
*rtld_total_timep
)
2713 #ifndef HP_TIMING_NONAVAIL
2718 /* Total time rtld used. */
2719 if (HP_TIMING_AVAIL
)
2721 HP_TIMING_PRINT (buf
, sizeof (buf
), *rtld_total_timep
);
2722 _dl_debug_printf ("\nruntime linker statistics:\n"
2723 " total startup time in dynamic loader: %s\n", buf
);
2725 /* Print relocation statistics. */
2727 HP_TIMING_PRINT (buf
, sizeof (buf
), relocate_time
);
2728 cp
= _itoa ((1000ULL * relocate_time
) / *rtld_total_timep
,
2729 pbuf
+ sizeof (pbuf
), 10, 0);
2731 switch (pbuf
+ sizeof (pbuf
) - cp
)
2742 _dl_debug_printf ("\
2743 time needed for relocation: %s (%s%%)\n", buf
, pbuf
);
2747 unsigned long int num_relative_relocations
= 0;
2748 for (Lmid_t ns
= 0; ns
< GL(dl_nns
); ++ns
)
2750 if (GL(dl_ns
)[ns
]._ns_loaded
== NULL
)
2753 struct r_scope_elem
*scope
= &GL(dl_ns
)[ns
]._ns_loaded
->l_searchlist
;
2755 for (unsigned int i
= 0; i
< scope
->r_nlist
; i
++)
2757 struct link_map
*l
= scope
->r_list
[i
];
2759 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELCOUNT
)])
2760 num_relative_relocations
2761 += l
->l_info
[VERSYMIDX (DT_RELCOUNT
)]->d_un
.d_val
;
2762 #ifndef ELF_MACHINE_REL_RELATIVE
2763 /* Relative relocations are processed on these architectures if
2764 library is loaded to different address than p_vaddr or
2765 if not prelinked. */
2766 if ((l
->l_addr
!= 0 || !l
->l_info
[VALIDX(DT_GNU_PRELINKED
)])
2767 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2769 /* On e.g. IA-64 or Alpha, relative relocations are processed
2770 only if library is loaded to different address than p_vaddr. */
2771 if (l
->l_addr
!= 0 && l
->l_info
[VERSYMIDX (DT_RELACOUNT
)])
2773 num_relative_relocations
2774 += l
->l_info
[VERSYMIDX (DT_RELACOUNT
)]->d_un
.d_val
;
2778 _dl_debug_printf (" number of relocations: %lu\n"
2779 " number of relocations from cache: %lu\n"
2780 " number of relative relocations: %lu\n",
2781 GL(dl_num_relocations
),
2782 GL(dl_num_cache_relocations
),
2783 num_relative_relocations
);
2785 #ifndef HP_TIMING_NONAVAIL
2786 /* Time spend while loading the object and the dependencies. */
2787 if (HP_TIMING_AVAIL
)
2790 HP_TIMING_PRINT (buf
, sizeof (buf
), load_time
);
2791 cp
= _itoa ((1000ULL * load_time
) / *rtld_total_timep
,
2792 pbuf
+ sizeof (pbuf
), 10, 0);
2794 switch (pbuf
+ sizeof (pbuf
) - cp
)
2805 _dl_debug_printf ("\
2806 time needed to load objects: %s (%s%%)\n",