1 /* Run time dynamic linker.
2 Copyright (C) 1995-2010, 2011 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
28 #include <sys/param.h>
31 #include <stdio-common/_itoa.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.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 [LM_ID_BASE] = { ._ns_unique_sym_table
137 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
140 /* If we would use strong_alias here the compiler would see a
141 non-hidden definition. This would undo the effect of the previous
142 declaration. So spell out was strong_alias does plus add the
143 visibility attribute. */
144 extern struct rtld_global _rtld_local
145 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
148 /* This variable is similar to _rtld_local, but all values are
149 read-only after relocation. */
150 struct rtld_global_ro _rtld_global_ro attribute_relro =
152 /* Get architecture specific initializer. */
153 #include <dl-procinfo.c>
154 #ifdef NEED_DL_SYSINFO
155 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
157 ._dl_debug_fd = STDERR_FILENO,
158 ._dl_use_load_bias = -2,
159 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
160 ._dl_hwcap_mask = HWCAP_IMPORTANT,
162 ._dl_fpu_control = _FPU_DEFAULT,
163 ._dl_pointer_guard = 1,
165 /* Function pointers. */
166 ._dl_debug_printf = _dl_debug_printf,
167 ._dl_catch_error = _dl_catch_error,
168 ._dl_signal_error = _dl_signal_error,
169 ._dl_mcount = _dl_mcount_internal,
170 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
171 ._dl_check_caller = _dl_check_caller,
172 ._dl_open = _dl_open,
173 ._dl_close = _dl_close,
174 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
175 #ifdef HAVE_DL_DISCOVER_OSVERSION
176 ._dl_discover_osversion = _dl_discover_osversion
179 /* If we would use strong_alias here the compiler would see a
180 non-hidden definition. This would undo the effect of the previous
181 declaration. So spell out was strong_alias does plus add the
182 visibility attribute. */
183 extern struct rtld_global_ro _rtld_local_ro
184 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
187 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
188 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
190 /* These two variables cannot be moved into .data.rel.ro. */
191 static struct libname_list _dl_rtld_libname;
192 static struct libname_list _dl_rtld_libname2;
194 /* We expect less than a second for relocation. */
195 #ifdef HP_SMALL_TIMING_AVAIL
196 # undef HP_TIMING_AVAIL
197 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
200 /* Variable for statistics. */
201 #ifndef HP_TIMING_NONAVAIL
202 static hp_timing_t relocate_time;
203 static hp_timing_t load_time attribute_relro;
204 static hp_timing_t start_time attribute_relro;
207 /* Additional definitions needed by TLS initialization. */
208 #ifdef TLS_INIT_HELPER
212 /* Helper function for syscall implementation. */
213 #ifdef DL_SYSINFO_IMPLEMENTATION
214 DL_SYSINFO_IMPLEMENTATION
217 /* Before ld.so is relocated we must not access variables which need
218 relocations. This means variables which are exported. Variables
219 declared as static are fine. If we can mark a variable hidden this
220 is fine, too. The latter is important here. We can avoid setting
221 up a temporary link map for ld.so if we can mark _rtld_global as
223 #ifdef PI_STATIC_AND_HIDDEN
224 # define DONT_USE_BOOTSTRAP_MAP 1
227 #ifdef DONT_USE_BOOTSTRAP_MAP
228 static ElfW(Addr) _dl_start_final (void *arg);
230 struct dl_start_final_info
233 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
234 hp_timing_t start_time;
237 static ElfW(Addr) _dl_start_final (void *arg,
238 struct dl_start_final_info *info);
241 /* These defined magically in the linker script. */
242 extern char _begin[] attribute_hidden;
243 extern char _etext[] attribute_hidden;
244 extern char _end[] attribute_hidden;
250 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
254 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
255 + DT_EXTRANUM + DT_VALTAGIDX (tag))
258 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
259 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
262 /* This is the second half of _dl_start (below). It can be inlined safely
263 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
264 references. When the tools don't permit us to avoid using a GOT entry
265 for _dl_rtld_global (no attribute_hidden support), we must make sure
266 this function is not inlined (see below). */
268 #ifdef DONT_USE_BOOTSTRAP_MAP
269 static inline ElfW(Addr) __attribute__ ((always_inline))
270 _dl_start_final (void *arg)
272 static ElfW(Addr) __attribute__ ((noinline))
273 _dl_start_final (void *arg, struct dl_start_final_info *info)
276 ElfW(Addr) start_addr;
280 /* If it hasn't happen yet record the startup time. */
281 if (! HP_TIMING_INLINE)
282 HP_TIMING_NOW (start_time);
283 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
285 start_time = info->start_time;
288 /* Initialize the timing functions. */
289 HP_TIMING_DIFF_INIT ();
292 /* Transfer data about ourselves to the permanent link_map structure. */
293 #ifndef DONT_USE_BOOTSTRAP_MAP
294 GL(dl_rtld_map).l_addr = info->l.l_addr;
295 GL(dl_rtld_map).l_ld = info->l.l_ld;
296 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
297 sizeof GL(dl_rtld_map).l_info);
298 GL(dl_rtld_map).l_mach = info->l.l_mach;
299 GL(dl_rtld_map).l_relocated = 1;
301 _dl_setup_hash (&GL(dl_rtld_map));
302 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
303 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
304 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
305 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
306 /* Copy the TLS related data if necessary. */
307 #ifndef DONT_USE_BOOTSTRAP_MAP
309 assert (info->l.l_tls_modid != 0);
310 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
311 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
312 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
313 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
314 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
315 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
316 GL(dl_rtld_map).l_tls_modid = 1;
318 # if NO_TLS_OFFSET != 0
319 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
326 HP_TIMING_NOW (GL(dl_cpuclock_offset));
329 /* Initialize the stack end variable. */
330 __libc_stack_end = __builtin_frame_address (0);
332 /* Call the OS-dependent function to set up life so we can do things like
333 file access. It will call `dl_main' (below) to do all the real work
334 of the dynamic linker, and then unwind our frame and run the user
335 entry point on the same stack we entered on. */
336 start_addr = _dl_sysdep_start (arg, &dl_main);
338 #ifndef HP_TIMING_NONAVAIL
339 hp_timing_t rtld_total_time;
342 hp_timing_t end_time;
344 /* Get the current time. */
345 HP_TIMING_NOW (end_time);
347 /* Compute the difference. */
348 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
352 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
354 #ifndef HP_TIMING_NONAVAIL
355 print_statistics (&rtld_total_time);
357 print_statistics (NULL);
364 static ElfW(Addr) __attribute_used__ internal_function
365 _dl_start (void *arg)
367 #ifdef DONT_USE_BOOTSTRAP_MAP
368 # define bootstrap_map GL(dl_rtld_map)
370 struct dl_start_final_info info;
371 # define bootstrap_map info.l
374 /* This #define produces dynamic linking inline functions for
375 bootstrap relocation instead of general-purpose relocation.
376 Since ld.so must not have any undefined symbols the result
377 is trivial: always the map of ld.so itself. */
378 #define RTLD_BOOTSTRAP
379 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
380 #include "dynamic-link.h"
382 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
383 #ifdef DONT_USE_BOOTSTRAP_MAP
384 HP_TIMING_NOW (start_time);
386 HP_TIMING_NOW (info.start_time);
389 /* Partly clean the `bootstrap_map' structure up. Don't use
390 `memset' since it might not be built in or inlined and we cannot
391 make function calls at this point. Use '__builtin_memset' if we
392 know it is available. We do not have to clear the memory if we
393 do not have to use the temporary bootstrap_map. Global variables
394 are initialized to zero by default. */
395 #ifndef DONT_USE_BOOTSTRAP_MAP
396 # ifdef HAVE_BUILTIN_MEMSET
397 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
400 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
402 bootstrap_map.l_info[cnt] = 0;
405 bootstrap_map.l_tls_modid = 0;
409 /* Figure out the run-time load address of the dynamic linker itself. */
410 bootstrap_map.l_addr = elf_machine_load_address ();
412 /* Read our own dynamic section and fill in the info array. */
413 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
414 elf_get_dynamic_info (&bootstrap_map, NULL);
416 #if NO_TLS_OFFSET != 0
417 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
420 /* Get the dynamic linker's own program header. First we need the ELF
421 file header. The `_begin' symbol created by the linker script points
422 to it. When we have something like GOTOFF relocs, we can use a plain
423 reference to find the runtime address. Without that, we have to rely
424 on the `l_addr' value, which is not the value we want when prelinked. */
428 # ifdef DONT_USE_BOOTSTRAP_MAP
429 = (ElfW(Ehdr) *) &_begin;
431 # error This will not work with prelink.
432 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
434 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
435 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
437 if (phdr[cnt].p_type == PT_TLS)
440 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
443 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
444 bootstrap_map.l_tls_align = phdr[cnt].p_align;
445 if (phdr[cnt].p_align == 0)
446 bootstrap_map.l_tls_firstbyte_offset = 0;
448 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
449 & (phdr[cnt].p_align - 1));
450 assert (bootstrap_map.l_tls_blocksize != 0);
451 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
452 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
453 + phdr[cnt].p_vaddr);
455 /* We can now allocate the initial TLS block. This can happen
456 on the stack. We'll get the final memory later when we
457 know all about the various objects loaded at startup
460 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
465 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
466 bootstrap_map.l_tls_align)
467 + bootstrap_map.l_tls_blocksize
470 /* In case a model with a different layout for the TCB and DTV
471 is defined add another #elif here and in the following #ifs. */
472 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
474 /* Align the TLS block. */
475 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
478 /* Initialize the dtv. [0] is the length, [1] the generation
480 initdtv[0].counter = 1;
481 initdtv[1].counter = 0;
483 /* Initialize the TLS block. */
485 initdtv[2].pointer = tlsblock;
487 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
488 bootstrap_map.l_tls_align);
489 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
491 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
493 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
494 bootstrap_map.l_tls_initimage_size);
495 # ifdef HAVE_BUILTIN_MEMSET
496 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
497 - bootstrap_map.l_tls_initimage_size));
500 size_t remaining = (bootstrap_map.l_tls_blocksize
501 - bootstrap_map.l_tls_initimage_size);
502 while (remaining-- > 0)
507 /* Install the pointer to the dtv. */
509 /* Initialize the thread pointer. */
511 bootstrap_map.l_tls_offset
512 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
514 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
517 const char *lossage = TLS_INIT_TP ((char *) tlsblock
518 + bootstrap_map.l_tls_offset, 0);
520 INSTALL_DTV (tlsblock, initdtv);
521 const char *lossage = TLS_INIT_TP (tlsblock, 0);
523 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
525 if (__builtin_expect (lossage != NULL, 0))
526 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
529 /* So far this is module number one. */
530 bootstrap_map.l_tls_modid = 1;
532 /* There can only be one PT_TLS entry. */
535 #endif /* USE___THREAD */
537 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
538 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
541 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
543 /* Relocate ourselves so we can do normal function calls and
544 data access using the global offset table. */
546 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
548 bootstrap_map.l_relocated = 1;
550 /* Please note that we don't allow profiling of this object and
551 therefore need not test whether we have to allocate the array
552 for the relocation results (as done in dl-reloc.c). */
554 /* Now life is sane; we can call functions and access global data.
555 Set up to use the operating system facilities, and find out from
556 the operating system's program loader where to find the program
557 header table in core. Put the rest of _dl_start into a separate
558 function, that way the compiler cannot put accesses to the GOT
559 before ELF_DYNAMIC_RELOCATE. */
561 #ifdef DONT_USE_BOOTSTRAP_MAP
562 ElfW(Addr) entry = _dl_start_final (arg);
564 ElfW(Addr) entry = _dl_start_final (arg, &info);
567 #ifndef ELF_MACHINE_START_ADDRESS
568 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
571 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
577 /* Now life is peachy; we can do all normal operations.
578 On to the real work. */
580 /* Some helper functions. */
582 /* Arguments to relocate_doit. */
591 /* Argument to map_doit. */
593 struct link_map *loader;
595 /* Return value of map_doit. */
596 struct link_map *map;
602 struct link_map *map;
608 struct link_map *map;
612 /* Arguments to version_check_doit. */
613 struct version_check_args
620 relocate_doit (void *a)
622 struct relocate_args *args = (struct relocate_args *) a;
624 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
630 struct map_args *args = (struct map_args *) a;
631 args->map = _dl_map_object (args->loader, args->str, lt_library, 0,
632 args->mode, LM_ID_BASE);
636 dlmopen_doit (void *a)
638 struct dlmopen_args *args = (struct dlmopen_args *) a;
639 args->map = _dl_open (args->fname,
640 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
642 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
647 lookup_doit (void *a)
649 struct lookup_args *args = (struct lookup_args *) a;
650 const ElfW(Sym) *ref = NULL;
652 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
653 args->map->l_local_scope, NULL, 0,
654 DL_LOOKUP_RETURN_NEWEST, NULL);
656 args->result = DL_SYMBOL_ADDRESS (l, ref);
660 version_check_doit (void *a)
662 struct version_check_args *args = (struct version_check_args *) a;
663 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
664 args->dotrace) && args->doexit)
665 /* We cannot start the application. Abort now. */
670 static inline struct link_map *
671 find_needed (const char *name)
673 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
674 unsigned int n = scope->r_nlist;
677 if (_dl_name_match_p (name, scope->r_list[n]))
678 return scope->r_list[n];
680 /* Should never happen. */
685 match_version (const char *string, struct link_map *map)
687 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
690 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
691 if (map->l_info[VERDEFTAG] == NULL)
692 /* The file has no symbol versioning. */
695 def = (ElfW(Verdef) *) ((char *) map->l_addr
696 + map->l_info[VERDEFTAG]->d_un.d_ptr);
699 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
701 /* Compare the version strings. */
702 if (strcmp (string, strtab + aux->vda_name) == 0)
706 /* If no more definitions we failed to find what we want. */
707 if (def->vd_next == 0)
710 /* Next definition. */
711 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
717 static bool tls_init_tp_called;
722 /* Number of elements in the static TLS block. */
723 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
725 /* Do not do this twice. The audit interface might have required
726 the DTV interfaces to be set up early. */
727 if (GL(dl_initial_dtv) != NULL)
730 /* Allocate the array which contains the information about the
731 dtv slots. We allocate a few entries more than needed to
732 avoid the need for reallocation. */
733 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
736 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
737 calloc (sizeof (struct dtv_slotinfo_list)
738 + nelem * sizeof (struct dtv_slotinfo), 1);
739 /* No need to check the return value. If memory allocation failed
740 the program would have been terminated. */
742 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
743 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
744 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
746 /* Fill in the information from the loaded modules. No namespace
747 but the base one can be filled at this time. */
748 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
750 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
752 if (l->l_tls_blocksize != 0)
754 /* This is a module with TLS data. Store the map reference.
755 The generation counter is zero. */
757 /* slotinfo[i].gen = 0; */
760 assert (i == GL(dl_tls_max_dtv_idx));
762 /* Compute the TLS offsets for the various blocks. */
763 _dl_determine_tlsoffset ();
765 /* Construct the static TLS block and the dtv for the initial
766 thread. For some platforms this will include allocating memory
767 for the thread descriptor. The memory for the TLS block will
768 never be freed. It should be allocated accordingly. The dtv
769 array can be changed if dynamic loading requires it. */
770 void *tcbp = _dl_allocate_tls_storage ();
773 cannot allocate TLS data structures for initial thread");
775 /* Store for detection of the special case by __tls_get_addr
776 so it knows not to pass this dtv to the normal realloc. */
777 GL(dl_initial_dtv) = GET_DTV (tcbp);
779 /* And finally install it for the main thread. If ld.so itself uses
780 TLS we know the thread pointer was initialized earlier. */
781 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
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
877 /* The library search path. */
878 static const char *library_path attribute_relro;
879 /* The list preloaded objects. */
880 static const char *preloadlist attribute_relro;
881 /* Nonzero if information about versions has to be printed. */
882 static int version_info attribute_relro;
885 dl_main (const ElfW(Phdr) *phdr,
887 ElfW(Addr) *user_entry,
890 const ElfW(Phdr) *ph;
892 struct link_map *main_map;
895 bool has_interp = false;
897 bool prelinked = false;
898 bool rtld_is_main = false;
899 #ifndef HP_TIMING_NONAVAIL
906 #ifdef _LIBC_REENTRANT
907 /* Explicit initialization since the reloc would just be more work. */
908 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
911 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
913 #if defined SHARED && defined _LIBC_REENTRANT \
914 && defined __rtld_lock_default_lock_recursive
915 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
916 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
919 /* The explicit initialization here is cheaper than processing the reloc
920 in the _rtld_local definition's initializer. */
921 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
923 /* Process the environment variable which control the behaviour. */
924 process_envvars (&mode);
926 #ifndef HAVE_INLINED_SYSCALLS
927 /* Set up a flag which tells we are just starting. */
928 INTUSE(_dl_starting_up) = 1;
931 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
933 /* Ho ho. We are not the program interpreter! We are the program
934 itself! This means someone ran ld.so as a command. Well, that
935 might be convenient to do sometimes. We support it by
936 interpreting the args like this:
938 ld.so PROGRAM ARGS...
940 The first argument is the name of a file containing an ELF
941 executable we will load and run with the following arguments.
942 To simplify life here, PROGRAM is searched for using the
943 normal rules for shared objects, rather than $PATH or anything
944 like that. We just load it and use its entry point; we don't
945 pay attention to its PT_INTERP command (we are the interpreter
946 ourselves). This is an easy way to test a new ld.so before
950 /* Note the place where the dynamic linker actually came from. */
951 GL(dl_rtld_map).l_name = rtld_progname;
954 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
957 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
963 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
971 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
974 library_path = INTUSE(_dl_argv)[2];
978 INTUSE(_dl_argv) += 2;
980 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
983 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
987 INTUSE(_dl_argv) += 2;
989 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
991 process_dl_audit (INTUSE(_dl_argv)[2]);
995 INTUSE(_dl_argv) += 2;
1000 /* If we have no further argument the program was called incorrectly.
1001 Grant the user some education. */
1003 _dl_fatal_printf ("\
1004 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1005 You have invoked `ld.so', the helper program for shared library executables.\n\
1006 This program usually lives in the file `/lib/ld.so', and special directives\n\
1007 in executable files using ELF shared libraries tell the system's program\n\
1008 loader to load the helper program from this file. This helper program loads\n\
1009 the shared libraries needed by the program executable, prepares the program\n\
1010 to run, and runs it. You may invoke this helper program directly from the\n\
1011 command line to load and run an ELF executable file; this is like executing\n\
1012 that file itself, but always uses this helper program from the file you\n\
1013 specified, instead of the helper program file specified in the executable\n\
1014 file you run. This is mostly of use for maintainers to test new versions\n\
1015 of this helper program; chances are you did not intend to run this program.\n\
1017 --list list all dependencies and how they are resolved\n\
1018 --verify verify that given object really is a dynamically linked\n\
1019 object we can handle\n\
1020 --library-path PATH use given PATH instead of content of the environment\n\
1021 variable LD_LIBRARY_PATH\n\
1022 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1024 --audit LIST use objects named in LIST as auditors\n");
1030 /* The initialization of _dl_stack_flags done below assumes the
1031 executable's PT_GNU_STACK may have been honored by the kernel, and
1032 so a PT_GNU_STACK with PF_X set means the stack started out with
1033 execute permission. However, this is not really true if the
1034 dynamic linker is the executable the kernel loaded. For this
1035 case, we must reinitialize _dl_stack_flags to match the dynamic
1036 linker itself. If the dynamic linker was built with a
1037 PT_GNU_STACK, then the kernel may have loaded us with a
1038 nonexecutable stack that we will have to make executable when we
1039 load the program below unless it has a PT_GNU_STACK indicating
1040 nonexecutable stack is ok. */
1042 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1043 if (ph->p_type == PT_GNU_STACK)
1045 GL(dl_stack_flags) = ph->p_flags;
1049 if (__builtin_expect (mode, normal) == verify)
1051 const char *objname;
1052 const char *err_str = NULL;
1053 struct map_args args;
1056 args.str = rtld_progname;
1058 args.mode = __RTLD_OPENEXEC;
1059 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1061 if (__builtin_expect (err_str != NULL, 0))
1062 /* We don't free the returned string, the programs stops
1064 _exit (EXIT_FAILURE);
1068 HP_TIMING_NOW (start);
1069 _dl_map_object (NULL, rtld_progname, lt_library, 0,
1070 __RTLD_OPENEXEC, LM_ID_BASE);
1071 HP_TIMING_NOW (stop);
1073 HP_TIMING_DIFF (load_time, start, stop);
1076 /* Now the map for the main executable is available. */
1077 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1079 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1080 && main_map->l_info[DT_SONAME] != NULL
1081 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1082 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val,
1083 (const char *) D_PTR (main_map, l_info[DT_STRTAB])
1084 + main_map->l_info[DT_SONAME]->d_un.d_val) == 0)
1085 _dl_fatal_printf ("loader cannot load itself\n");
1087 phdr = main_map->l_phdr;
1088 phnum = main_map->l_phnum;
1089 /* We overwrite here a pointer to a malloc()ed string. But since
1090 the malloc() implementation used at this point is the dummy
1091 implementations which has no real free() function it does not
1092 makes sense to free the old string first. */
1093 main_map->l_name = (char *) "";
1094 *user_entry = main_map->l_entry;
1096 #ifdef HAVE_AUX_VECTOR
1097 /* Adjust the on-stack auxiliary vector so that it looks like the
1098 binary was executed directly. */
1099 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1103 av->a_un.a_val = (uintptr_t) phdr;
1106 av->a_un.a_val = phnum;
1109 av->a_un.a_val = *user_entry;
1116 /* Create a link_map for the executable itself.
1117 This will be what dlopen on "" returns. */
1118 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1119 __RTLD_OPENEXEC, LM_ID_BASE);
1120 assert (main_map != NULL);
1121 main_map->l_phdr = phdr;
1122 main_map->l_phnum = phnum;
1123 main_map->l_entry = *user_entry;
1125 /* Even though the link map is not yet fully initialized we can add
1126 it to the map list since there are no possible users running yet. */
1127 _dl_add_to_namespace_list (main_map, LM_ID_BASE);
1128 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1130 /* At this point we are in a bit of trouble. We would have to
1131 fill in the values for l_dev and l_ino. But in general we
1132 do not know where the file is. We also do not handle AT_EXECFD
1133 even if it would be passed up.
1135 We leave the values here defined to 0. This is normally no
1136 problem as the program code itself is normally no shared
1137 object and therefore cannot be loaded dynamically. Nothing
1138 prevent the use of dynamic binaries and in these situations
1139 we might get problems. We might not be able to find out
1140 whether the object is already loaded. But since there is no
1141 easy way out and because the dynamic binary must also not
1142 have an SONAME we ignore this program for now. If it becomes
1143 a problem we can force people using SONAMEs. */
1145 /* We delay initializing the path structure until we got the dynamic
1146 information for the program. */
1149 main_map->l_map_end = 0;
1150 main_map->l_text_end = 0;
1151 /* Perhaps the executable has no PT_LOAD header entries at all. */
1152 main_map->l_map_start = ~0;
1153 /* And it was opened directly. */
1154 ++main_map->l_direct_opencount;
1156 /* Scan the program header table for the dynamic section. */
1157 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1161 /* Find out the load address. */
1162 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1165 /* This tells us where to find the dynamic section,
1166 which tells us everything we need to do. */
1167 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1170 /* This "interpreter segment" was used by the program loader to
1171 find the program interpreter, which is this program itself, the
1172 dynamic linker. We note what name finds us, so that a future
1173 dlopen call or DT_NEEDED entry, for something that wants to link
1174 against the dynamic linker as a shared library, will know that
1175 the shared object is already loaded. */
1176 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1178 /* _dl_rtld_libname.next = NULL; Already zero. */
1179 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1181 /* Ordinarilly, we would get additional names for the loader from
1182 our DT_SONAME. This can't happen if we were actually linked as
1183 a static executable (detect this case when we have no DYNAMIC).
1184 If so, assume the filename component of the interpreter path to
1185 be our SONAME, and add it to our name list. */
1186 if (GL(dl_rtld_map).l_ld == NULL)
1188 const char *p = NULL;
1189 const char *cp = _dl_rtld_libname.name;
1191 /* Find the filename part of the path. */
1198 _dl_rtld_libname2.name = p;
1199 /* _dl_rtld_libname2.next = NULL; Already zero. */
1200 _dl_rtld_libname.next = &_dl_rtld_libname2;
1208 ElfW(Addr) mapstart;
1209 ElfW(Addr) allocend;
1211 /* Remember where the main program starts in memory. */
1212 mapstart = (main_map->l_addr
1213 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1214 if (main_map->l_map_start > mapstart)
1215 main_map->l_map_start = mapstart;
1217 /* Also where it ends. */
1218 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1219 if (main_map->l_map_end < allocend)
1220 main_map->l_map_end = allocend;
1221 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1222 main_map->l_text_end = allocend;
1227 if (ph->p_memsz > 0)
1229 /* Note that in the case the dynamic linker we duplicate work
1230 here since we read the PT_TLS entry already in
1231 _dl_start_final. But the result is repeatable so do not
1232 check for this special but unimportant case. */
1233 main_map->l_tls_blocksize = ph->p_memsz;
1234 main_map->l_tls_align = ph->p_align;
1235 if (ph->p_align == 0)
1236 main_map->l_tls_firstbyte_offset = 0;
1238 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1239 & (ph->p_align - 1));
1240 main_map->l_tls_initimage_size = ph->p_filesz;
1241 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1243 /* This image gets the ID one. */
1244 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1249 GL(dl_stack_flags) = ph->p_flags;
1253 main_map->l_relro_addr = ph->p_vaddr;
1254 main_map->l_relro_size = ph->p_memsz;
1258 /* Adjust the address of the TLS initialization image in case
1259 the executable is actually an ET_DYN object. */
1260 if (main_map->l_tls_initimage != NULL)
1261 main_map->l_tls_initimage
1262 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1263 if (! main_map->l_map_end)
1264 main_map->l_map_end = ~0;
1265 if (! main_map->l_text_end)
1266 main_map->l_text_end = ~0;
1267 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1269 /* We were invoked directly, so the program might not have a
1271 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1272 /* _dl_rtld_libname.next = NULL; Already zero. */
1273 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1276 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1278 /* If the current libname is different from the SONAME, add the
1280 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1281 && strcmp (GL(dl_rtld_map).l_libname->name,
1282 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1283 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1285 static struct libname_list newname;
1286 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1287 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1288 newname.next = NULL;
1289 newname.dont_free = 1;
1291 assert (GL(dl_rtld_map).l_libname->next == NULL);
1292 GL(dl_rtld_map).l_libname->next = &newname;
1294 /* The ld.so must be relocated since otherwise loading audit modules
1295 will fail since they reuse the very same ld.so. */
1296 assert (GL(dl_rtld_map).l_relocated);
1300 /* Extract the contents of the dynamic section for easy access. */
1301 elf_get_dynamic_info (main_map, NULL);
1302 /* Set up our cache of pointers into the hash table. */
1303 _dl_setup_hash (main_map);
1306 if (__builtin_expect (mode, normal) == verify)
1308 /* We were called just to verify that this is a dynamic
1309 executable using us as the program interpreter. Exit with an
1310 error if we were not able to load the binary or no interpreter
1311 is specified (i.e., this is no dynamically linked binary. */
1312 if (main_map->l_ld == NULL)
1315 /* We allow here some platform specific code. */
1316 #ifdef DISTINGUISH_LIB_VERSIONS
1317 DISTINGUISH_LIB_VERSIONS;
1319 _exit (has_interp ? 0 : 2);
1322 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1323 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1324 /* Set up the data structures for the system-supplied DSO early,
1325 so they can influence _dl_init_paths. */
1326 if (GLRO(dl_sysinfo_dso) != NULL)
1328 /* Do an abridged version of the work _dl_map_object_from_fd would do
1329 to map in the object. It's already mapped and prelinked (and
1330 better be, since it's read-only and so we couldn't relocate it).
1331 We just want our data structures to describe it as if we had just
1332 mapped and relocated it normally. */
1333 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1335 if (__builtin_expect (l != NULL, 1))
1337 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1339 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1340 + GLRO(dl_sysinfo_dso)->e_phoff);
1341 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1342 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1344 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1345 if (ph->p_type == PT_DYNAMIC)
1347 l->l_ld = (void *) ph->p_vaddr;
1348 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1350 else if (ph->p_type == PT_LOAD)
1353 l->l_addr = ph->p_vaddr;
1354 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1355 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1356 if ((ph->p_flags & PF_X)
1357 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1358 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1361 /* There must be no TLS segment. */
1362 assert (ph->p_type != PT_TLS);
1364 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1365 l->l_addr = l->l_map_start - l->l_addr;
1366 l->l_map_end += l->l_addr;
1367 l->l_text_end += l->l_addr;
1368 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1369 elf_get_dynamic_info (l, dyn_temp);
1373 /* Initialize l_local_scope to contain just this map. This allows
1374 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1375 So we create a single entry list pointing to l_real as its only
1377 l->l_local_scope[0]->r_nlist = 1;
1378 l->l_local_scope[0]->r_list = &l->l_real;
1380 /* Now that we have the info handy, use the DSO image's soname
1381 so this object can be looked up by name. Note that we do not
1382 set l_name here. That field gives the file name of the DSO,
1383 and this DSO is not associated with any file. */
1384 if (l->l_info[DT_SONAME] != NULL)
1386 /* Work around a kernel problem. The kernel cannot handle
1387 addresses in the vsyscall DSO pages in writev() calls. */
1388 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1389 + l->l_info[DT_SONAME]->d_un.d_val);
1390 size_t len = strlen (dsoname);
1391 char *copy = malloc (len);
1393 _dl_fatal_printf ("out of memory\n");
1394 l->l_libname->name = l->l_name = memcpy (copy, dsoname, len);
1397 /* Add the vDSO to the object list. */
1398 _dl_add_to_namespace_list (l, LM_ID_BASE);
1400 /* Rearrange the list so this DSO appears after rtld_map. */
1401 assert (l->l_next == NULL);
1402 assert (l->l_prev == main_map);
1403 GL(dl_rtld_map).l_next = l;
1404 l->l_prev = &GL(dl_rtld_map);
1405 first_preload = &l->l_next;
1407 /* We have a prelinked DSO preloaded by the system. */
1408 GLRO(dl_sysinfo_map) = l;
1409 # ifdef NEED_DL_SYSINFO
1410 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1411 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1417 #ifdef DL_SYSDEP_OSCHECK
1418 DL_SYSDEP_OSCHECK (dl_fatal);
1421 /* Initialize the data structures for the search paths for shared
1423 _dl_init_paths (library_path);
1425 /* Initialize _r_debug. */
1426 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1428 r->r_state = RT_CONSISTENT;
1430 /* Put the link_map for ourselves on the chain so it can be found by
1431 name. Note that at this point the global chain of link maps contains
1432 exactly one element, which is pointed to by dl_loaded. */
1433 if (! GL(dl_rtld_map).l_name)
1434 /* If not invoked directly, the dynamic linker shared object file was
1435 found by the PT_INTERP name. */
1436 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1437 GL(dl_rtld_map).l_type = lt_library;
1438 main_map->l_next = &GL(dl_rtld_map);
1439 GL(dl_rtld_map).l_prev = main_map;
1440 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1443 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1444 to not using bias for non-prelinked PIEs and libraries
1445 and using it for executables or prelinked PIEs or libraries. */
1446 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1447 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1449 /* Set up the program header information for the dynamic linker
1450 itself. It is needed in the dl_iterate_phdr() callbacks. */
1451 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1452 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1453 + rtld_ehdr->e_phoff);
1454 GL(dl_rtld_map).l_phdr = rtld_phdr;
1455 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1458 /* PT_GNU_RELRO is usually the last phdr. */
1459 size_t cnt = rtld_ehdr->e_phnum;
1461 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1463 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1464 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1468 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1469 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1470 /* Assign a module ID. Do this before loading any audit modules. */
1471 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1473 /* If we have auditing DSOs to load, do it now. */
1474 if (__builtin_expect (audit_list != NULL, 0))
1476 /* Iterate over all entries in the list. The order is important. */
1477 struct audit_ifaces *last_audit = NULL;
1478 struct audit_list *al = audit_list->next;
1480 /* Since we start using the auditing DSOs right away we need to
1481 initialize the data structures now. */
1484 /* Initialize security features. We need to do it this early
1485 since otherwise the constructors of the audit libraries will
1486 use different values (especially the pointer guard) and will
1492 int tls_idx = GL(dl_tls_max_dtv_idx);
1494 /* Now it is time to determine the layout of the static TLS
1495 block and allocate it for the initial thread. Note that we
1496 always allocate the static block, we never defer it even if
1497 no DF_STATIC_TLS bit is set. The reason is that we know
1498 glibc will use the static model. */
1499 struct dlmopen_args dlmargs;
1500 dlmargs.fname = al->name;
1503 const char *objname;
1504 const char *err_str = NULL;
1506 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1508 if (__builtin_expect (err_str != NULL, 0))
1511 _dl_error_printf ("\
1512 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1515 free ((char *) err_str);
1519 struct lookup_args largs;
1520 largs.name = "la_version";
1521 largs.map = dlmargs.map;
1523 /* Check whether the interface version matches. */
1524 (void) _dl_catch_error (&objname, &err_str, &malloced,
1525 lookup_doit, &largs);
1527 unsigned int (*laversion) (unsigned int);
1530 && (laversion = largs.result) != NULL
1531 && (lav = laversion (LAV_CURRENT)) > 0
1532 && lav <= LAV_CURRENT)
1534 /* Allocate structure for the callback function pointers.
1535 This call can never fail. */
1538 struct audit_ifaces ifaces;
1539 #define naudit_ifaces 8
1540 void (*fptr[naudit_ifaces]) (void);
1541 } *newp = malloc (sizeof (*newp));
1543 /* Names of the auditing interfaces. All in one
1545 static const char audit_iface_names[] =
1550 #if __ELF_NATIVE_CLASS == 32
1552 #elif __ELF_NATIVE_CLASS == 64
1555 # error "__ELF_NATIVE_CLASS must be defined"
1557 #define STRING(s) __STRING (s)
1558 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1559 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1561 unsigned int cnt = 0;
1562 const char *cp = audit_iface_names;
1566 (void) _dl_catch_error (&objname, &err_str, &malloced,
1567 lookup_doit, &largs);
1569 /* Store the pointer. */
1570 if (err_str == NULL && largs.result != NULL)
1572 newp->fptr[cnt] = largs.result;
1574 /* The dynamic linker link map is statically
1575 allocated, initialize the data now. */
1576 GL(dl_rtld_map).l_audit[cnt].cookie
1577 = (intptr_t) &GL(dl_rtld_map);
1580 newp->fptr[cnt] = NULL;
1583 cp = (char *) rawmemchr (cp, '\0') + 1;
1585 while (*cp != '\0');
1586 assert (cnt == naudit_ifaces);
1588 /* Now append the new auditing interface to the list. */
1589 newp->ifaces.next = NULL;
1590 if (last_audit == NULL)
1591 last_audit = GLRO(dl_audit) = &newp->ifaces;
1593 last_audit = last_audit->next = &newp->ifaces;
1596 /* Mark the DSO as being used for auditing. */
1597 dlmargs.map->l_auditing = 1;
1601 /* We cannot use the DSO, it does not have the
1602 appropriate interfaces or it expects something
1605 Lmid_t ns = dlmargs.map->l_ns;
1607 _dl_close (dlmargs.map);
1609 /* Make sure the namespace has been cleared entirely. */
1610 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1611 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1613 GL(dl_tls_max_dtv_idx) = tls_idx;
1620 while (al != audit_list->next);
1622 /* If we have any auditing modules, announce that we already
1623 have two objects loaded. */
1624 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1626 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1628 for (unsigned int outer = 0; outer < 2; ++outer)
1630 struct audit_ifaces *afct = GLRO(dl_audit);
1631 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1633 if (afct->objopen != NULL)
1635 ls[outer]->l_audit[cnt].bindflags
1636 = afct->objopen (ls[outer], LM_ID_BASE,
1637 &ls[outer]->l_audit[cnt].cookie);
1639 ls[outer]->l_audit_any_plt
1640 |= ls[outer]->l_audit[cnt].bindflags != 0;
1649 /* Set up debugging before the debugger is notified for the first time. */
1650 #ifdef ELF_MACHINE_DEBUG_SETUP
1651 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1652 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1653 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1655 if (main_map->l_info[DT_DEBUG] != NULL)
1656 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1657 with the run-time address of the r_debug structure */
1658 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1660 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1661 case you run gdb on the dynamic linker directly. */
1662 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1663 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1666 /* We start adding objects. */
1667 r->r_state = RT_ADD;
1670 /* Auditing checkpoint: we are ready to signal that the initial map
1671 is being constructed. */
1672 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1674 struct audit_ifaces *afct = GLRO(dl_audit);
1675 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1677 if (afct->activity != NULL)
1678 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1684 /* We have two ways to specify objects to preload: via environment
1685 variable and via the file /etc/ld.so.preload. The latter can also
1686 be used when security is enabled. */
1687 assert (*first_preload == NULL);
1688 struct link_map **preloads = NULL;
1689 unsigned int npreloads = 0;
1691 if (__builtin_expect (preloadlist != NULL, 0))
1693 /* The LD_PRELOAD environment variable gives list of libraries
1694 separated by white space or colons that are loaded before the
1695 executable's dependencies and prepended to the global scope
1696 list. If the binary is running setuid all elements
1697 containing a '/' are ignored since it is insecure. */
1698 char *list = strdupa (preloadlist);
1701 HP_TIMING_NOW (start);
1703 /* Prevent optimizing strsep. Speed is not important here. */
1704 while ((p = (strsep) (&list, " :")) != NULL)
1706 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1707 || strchr (p, '/') == NULL))
1708 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1710 HP_TIMING_NOW (stop);
1711 HP_TIMING_DIFF (diff, start, stop);
1712 HP_TIMING_ACCUM_NT (load_time, diff);
1715 /* There usually is no ld.so.preload file, it should only be used
1716 for emergencies and testing. So the open call etc should usually
1717 fail. Using access() on a non-existing file is faster than using
1718 open(). So we do this first. If it succeeds we do almost twice
1719 the work but this does not matter, since it is not for production
1721 static const char preload_file[] = "/etc/ld.so.preload";
1722 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1724 /* Read the contents of the file. */
1725 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1726 PROT_READ | PROT_WRITE);
1727 if (__builtin_expect (file != MAP_FAILED, 0))
1729 /* Parse the file. It contains names of libraries to be loaded,
1730 separated by white spaces or `:'. It may also contain
1731 comments introduced by `#'. */
1736 /* Eliminate comments. */
1741 char *comment = memchr (runp, '#', rest);
1742 if (comment == NULL)
1745 rest -= comment - runp;
1748 while (--rest > 0 && *++comment != '\n');
1751 /* We have one problematic case: if we have a name at the end of
1752 the file without a trailing terminating characters, we cannot
1753 place the \0. Handle the case separately. */
1754 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1755 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1757 problem = &file[file_size];
1758 while (problem > file && problem[-1] != ' '
1759 && problem[-1] != '\t'
1760 && problem[-1] != '\n' && problem[-1] != ':')
1769 file[file_size - 1] = '\0';
1772 HP_TIMING_NOW (start);
1774 if (file != problem)
1778 while ((p = strsep (&runp, ": \t\n")) != NULL)
1780 npreloads += do_preload (p, main_map, preload_file);
1783 if (problem != NULL)
1785 char *p = strndupa (problem, file_size - (problem - file));
1787 npreloads += do_preload (p, main_map, preload_file);
1790 HP_TIMING_NOW (stop);
1791 HP_TIMING_DIFF (diff, start, stop);
1792 HP_TIMING_ACCUM_NT (load_time, diff);
1794 /* We don't need the file anymore. */
1795 __munmap (file, file_size);
1799 if (__builtin_expect (*first_preload != NULL, 0))
1801 /* Set up PRELOADS with a vector of the preloaded libraries. */
1802 struct link_map *l = *first_preload;
1803 preloads = __alloca (npreloads * sizeof preloads[0]);
1810 assert (i == npreloads);
1813 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1814 specified some libraries to load, these are inserted before the actual
1815 dependencies in the executable's searchlist for symbol resolution. */
1816 HP_TIMING_NOW (start);
1817 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1818 HP_TIMING_NOW (stop);
1819 HP_TIMING_DIFF (diff, start, stop);
1820 HP_TIMING_ACCUM_NT (load_time, diff);
1822 /* Mark all objects as being in the global scope. */
1823 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1824 main_map->l_searchlist.r_list[--i]->l_global = 1;
1826 /* Remove _dl_rtld_map from the chain. */
1827 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1828 if (GL(dl_rtld_map).l_next != NULL)
1829 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1831 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1832 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1835 bool rtld_multiple_ref = false;
1836 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1838 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1839 put it back in the list of visible objects. We insert it into the
1840 chain in symbol search order because gdb uses the chain's order as
1841 its symbol search order. */
1842 rtld_multiple_ref = true;
1844 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1845 if (__builtin_expect (mode, normal) == normal)
1847 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1848 ? main_map->l_searchlist.r_list[i + 1]
1850 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1851 if (GLRO(dl_sysinfo_map) != NULL
1852 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1853 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1854 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1858 /* In trace mode there might be an invisible object (which we
1859 could not find) after the previous one in the search list.
1860 In this case it doesn't matter much where we put the
1861 interpreter object, so we just initialize the list pointer so
1862 that the assertion below holds. */
1863 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1865 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1866 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1867 if (GL(dl_rtld_map).l_next != NULL)
1869 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1870 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1874 /* Now let us see whether all libraries are available in the
1875 versions we need. */
1877 struct version_check_args args;
1878 args.doexit = mode == normal;
1879 args.dotrace = mode == trace;
1880 _dl_receive_error (print_missing_version, version_check_doit, &args);
1883 /* We do not initialize any of the TLS functionality unless any of the
1884 initial modules uses TLS. This makes dynamic loading of modules with
1885 TLS impossible, but to support it requires either eagerly doing setup
1886 now or lazily doing it later. Doing it now makes us incompatible with
1887 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1888 used. Trying to do it lazily is too hairy to try when there could be
1889 multiple threads (from a non-TLS-using libpthread). */
1890 bool was_tls_init_tp_called = tls_init_tp_called;
1894 if (__builtin_expect (audit_list == NULL, 1))
1895 /* Initialize security features. But only if we have not done it
1899 if (__builtin_expect (mode, normal) != normal)
1901 /* We were run just to list the shared libraries. It is
1902 important that we do this before real relocation, because the
1903 functions we call below for output may no longer work properly
1904 after relocation. */
1907 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1909 struct r_scope_elem *scope = &main_map->l_searchlist;
1911 for (i = 0; i < scope->r_nlist; i++)
1913 l = scope->r_list [i];
1916 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1919 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1920 GLRO(dl_trace_prelink_map) = l;
1921 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1922 l->l_libname->name[0] ? l->l_libname->name
1923 : rtld_progname ?: "<main program>",
1924 l->l_name[0] ? l->l_name
1925 : rtld_progname ?: "<main program>",
1926 (int) sizeof l->l_map_start * 2,
1927 (size_t) l->l_map_start,
1928 (int) sizeof l->l_addr * 2,
1929 (size_t) l->l_addr);
1932 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1933 (int) sizeof l->l_tls_offset * 2,
1934 (size_t) l->l_tls_offset);
1939 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1941 /* Look through the dependencies of the main executable
1942 and determine which of them is not actually
1944 struct link_map *l = main_map;
1946 /* Relocate the main executable. */
1947 struct relocate_args args = { .l = l,
1948 .reloc_mode = (GLRO(dl_lazy)
1950 _dl_receive_error (print_unresolved, relocate_doit, &args);
1952 /* This loop depends on the dependencies of the executable to
1953 correspond in number and order to the DT_NEEDED entries. */
1954 ElfW(Dyn) *dyn = main_map->l_ld;
1956 while (dyn->d_tag != DT_NULL)
1958 if (dyn->d_tag == DT_NEEDED)
1966 _dl_printf ("Unused direct dependencies:\n");
1970 _dl_printf ("\t%s\n", l->l_name);
1977 _exit (first != true);
1979 else if (! main_map->l_info[DT_NEEDED])
1980 _dl_printf ("\tstatically linked\n");
1983 for (l = main_map->l_next; l; l = l->l_next)
1985 /* The library was not found. */
1986 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1987 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1988 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1989 (int) sizeof l->l_map_start * 2,
1990 (size_t) l->l_map_start);
1992 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1993 l->l_name, (int) sizeof l->l_map_start * 2,
1994 (size_t) l->l_map_start);
1997 if (__builtin_expect (mode, trace) != trace)
1998 for (i = 1; i < (unsigned int) _dl_argc; ++i)
2000 const ElfW(Sym) *ref = NULL;
2001 ElfW(Addr) loadbase;
2004 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
2005 &ref, main_map->l_scope,
2006 NULL, ELF_RTYPE_CLASS_PLT,
2007 DL_LOOKUP_ADD_DEPENDENCY, NULL);
2009 loadbase = LOOKUP_VALUE_ADDRESS (result);
2011 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
2012 INTUSE(_dl_argv)[i],
2013 (int) sizeof ref->st_value * 2,
2014 (size_t) ref->st_value,
2015 (int) sizeof loadbase * 2, (size_t) loadbase);
2019 /* If LD_WARN is set, warn about undefined symbols. */
2020 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2022 /* We have to do symbol dependency testing. */
2023 struct relocate_args args;
2026 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2029 while (l->l_next != NULL)
2033 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2036 _dl_receive_error (print_unresolved, relocate_doit,
2043 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2044 && rtld_multiple_ref)
2046 /* Mark the link map as not yet relocated again. */
2047 GL(dl_rtld_map).l_relocated = 0;
2048 _dl_relocate_object (&GL(dl_rtld_map),
2049 main_map->l_scope, 0, 0);
2052 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2055 /* Print more information. This means here, print information
2056 about the versions needed. */
2058 struct link_map *map;
2060 for (map = main_map; map != NULL; map = map->l_next)
2063 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2069 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2070 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2074 _dl_printf ("\n\tVersion information:\n");
2078 _dl_printf ("\t%s:\n",
2079 map->l_name[0] ? map->l_name : rtld_progname);
2084 struct link_map *needed;
2086 needed = find_needed (strtab + ent->vn_file);
2087 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2091 const char *fname = NULL;
2094 && match_version (strtab + aux->vna_name,
2096 fname = needed->l_name;
2098 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2099 strtab + ent->vn_file,
2100 strtab + aux->vna_name,
2101 aux->vna_flags & VER_FLG_WEAK
2103 fname ?: "not found");
2105 if (aux->vna_next == 0)
2106 /* No more symbols. */
2110 aux = (ElfW(Vernaux) *) ((char *) aux
2114 if (ent->vn_next == 0)
2115 /* No more dependencies. */
2118 /* Next dependency. */
2119 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2128 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2129 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2130 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2132 ElfW(Lib) *liblist, *liblistend;
2133 struct link_map **r_list, **r_listend, *l;
2134 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2136 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2137 liblist = (ElfW(Lib) *)
2138 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2139 liblistend = (ElfW(Lib) *)
2141 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2142 r_list = main_map->l_searchlist.r_list;
2143 r_listend = r_list + main_map->l_searchlist.r_nlist;
2145 for (; r_list < r_listend && liblist < liblistend; r_list++)
2152 /* If the library is not mapped where it should, fail. */
2156 /* Next, check if checksum matches. */
2157 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2158 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2159 != liblist->l_checksum)
2162 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2163 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2164 != liblist->l_time_stamp)
2167 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2174 if (r_list == r_listend && liblist == liblistend)
2177 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2178 _dl_debug_printf ("\nprelink checking: %s\n",
2179 prelinked ? "ok" : "failed");
2183 /* Now set up the variable which helps the assembler startup code. */
2184 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2186 /* Save the information about the original global scope list since
2187 we need it in the memory handling later. */
2188 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2190 /* Remember the last search directory added at startup, now that
2191 malloc will no longer be the one from dl-minimal.c. */
2192 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2194 /* Print scope information. */
2195 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES, 0))
2197 _dl_debug_printf ("\nInitial object scopes\n");
2199 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2205 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2207 ElfW(Rela) *conflict, *conflictend;
2208 #ifndef HP_TIMING_NONAVAIL
2213 HP_TIMING_NOW (start);
2214 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2215 conflict = (ElfW(Rela) *)
2216 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2217 conflictend = (ElfW(Rela) *)
2219 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2220 _dl_resolve_conflicts (main_map, conflict, conflictend);
2221 HP_TIMING_NOW (stop);
2222 HP_TIMING_DIFF (relocate_time, start, stop);
2226 /* Mark all the objects so we know they have been already relocated. */
2227 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2230 if (l->l_relro_size)
2231 _dl_protect_relro (l);
2233 /* Add object to slot information data if necessasy. */
2234 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2235 _dl_add_to_slotinfo (l);
2240 /* Now we have all the objects loaded. Relocate them all except for
2241 the dynamic linker itself. We do this in reverse order so that copy
2242 relocs of earlier objects overwrite the data written by later
2243 objects. We do not re-relocate the dynamic linker itself in this
2244 loop because that could result in the GOT entries for functions we
2245 call being changed, and that would break us. It is safe to relocate
2246 the dynamic linker out of order because it has no copy relocs (we
2247 know that because it is self-contained). */
2249 int consider_profiling = GLRO(dl_profile) != NULL;
2250 #ifndef HP_TIMING_NONAVAIL
2255 /* If we are profiling we also must do lazy reloaction. */
2256 GLRO(dl_lazy) |= consider_profiling;
2258 struct link_map *l = main_map;
2262 HP_TIMING_NOW (start);
2265 /* While we are at it, help the memory handling a bit. We have to
2266 mark some data structures as allocated with the fake malloc()
2267 implementation in ld.so. */
2268 struct libname_list *lnp = l->l_libname->next;
2270 while (__builtin_expect (lnp != NULL, 0))
2276 if (l != &GL(dl_rtld_map))
2277 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2278 consider_profiling);
2280 /* Add object to slot information data if necessasy. */
2281 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2282 _dl_add_to_slotinfo (l);
2287 HP_TIMING_NOW (stop);
2289 HP_TIMING_DIFF (relocate_time, start, stop);
2291 /* Now enable profiling if needed. Like the previous call,
2292 this has to go here because the calls it makes should use the
2293 rtld versions of the functions (particularly calloc()), but it
2294 needs to have _dl_profile_map set up by the relocator. */
2295 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2296 /* We must prepare the profiling. */
2297 _dl_start_profile ();
2300 #ifndef NONTLS_INIT_TP
2301 # define NONTLS_INIT_TP do { } while (0)
2304 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2305 ++GL(dl_tls_generation);
2307 /* Now that we have completed relocation, the initializer data
2308 for the TLS blocks has its final values and we can copy them
2309 into the main thread's TLS area, which we allocated above. */
2310 _dl_allocate_tls_init (tcbp);
2312 /* And finally install it for the main thread. If ld.so itself uses
2313 TLS we know the thread pointer was initialized earlier. */
2314 if (! tls_init_tp_called)
2316 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2317 if (__builtin_expect (lossage != NULL, 0))
2318 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2322 /* Make sure no new search directories have been added. */
2323 assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
2325 if (! prelinked && rtld_multiple_ref)
2327 /* There was an explicit ref to the dynamic linker as a shared lib.
2328 Re-relocate ourselves with user-controlled symbol definitions.
2330 We must do this after TLS initialization in case after this
2331 re-relocation, we might call a user-supplied function
2332 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2334 #ifndef HP_TIMING_NONAVAIL
2340 HP_TIMING_NOW (start);
2341 /* Mark the link map as not yet relocated again. */
2342 GL(dl_rtld_map).l_relocated = 0;
2343 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2344 HP_TIMING_NOW (stop);
2345 HP_TIMING_DIFF (add, start, stop);
2346 HP_TIMING_ACCUM_NT (relocate_time, add);
2349 /* Do any necessary cleanups for the startup OS interface code.
2350 We do these now so that no calls are made after rtld re-relocation
2351 which might be resolved to different functions than we expect.
2352 We cannot do this before relocating the other objects because
2353 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2354 _dl_sysdep_start_cleanup ();
2357 /* Auditing checkpoint: we have added all objects. */
2358 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2360 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2361 /* Do not call the functions for any auditing object. */
2362 if (head->l_auditing == 0)
2364 struct audit_ifaces *afct = GLRO(dl_audit);
2365 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2367 if (afct->activity != NULL)
2368 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2376 /* Notify the debugger all new objects are now ready to go. We must re-get
2377 the address since by now the variable might be in another object. */
2378 r = _dl_debug_initialize (0, LM_ID_BASE);
2379 r->r_state = RT_CONSISTENT;
2383 /* We must munmap() the cache file. */
2384 _dl_unload_cache ();
2387 /* Once we return, _dl_sysdep_start will invoke
2388 the DT_INIT functions and then *USER_ENTRY. */
2391 /* This is a little helper function for resolving symbols while
2392 tracing the binary. */
2394 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2395 const char *errstring)
2397 if (objname[0] == '\0')
2398 objname = rtld_progname ?: "<main program>";
2399 _dl_error_printf ("%s (%s)\n", errstring, objname);
2402 /* This is a little helper function for resolving symbols while
2403 tracing the binary. */
2405 print_missing_version (int errcode __attribute__ ((unused)),
2406 const char *objname, const char *errstring)
2408 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2409 objname, errstring);
2412 /* Nonzero if any of the debugging options is enabled. */
2413 static int any_debug attribute_relro;
2415 /* Process the string given as the parameter which explains which debugging
2416 options are enabled. */
2418 process_dl_debug (const char *dl_debug)
2420 /* When adding new entries make sure that the maximal length of a name
2421 is correctly handled in the LD_DEBUG_HELP code below. */
2425 const char name[10];
2426 const char helptext[41];
2427 unsigned short int mask;
2430 #define LEN_AND_STR(str) sizeof (str) - 1, str
2431 { LEN_AND_STR ("libs"), "display library search paths",
2432 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2433 { LEN_AND_STR ("reloc"), "display relocation processing",
2434 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2435 { LEN_AND_STR ("files"), "display progress for input file",
2436 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2437 { LEN_AND_STR ("symbols"), "display symbol table processing",
2438 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2439 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2440 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2441 { LEN_AND_STR ("versions"), "display version dependencies",
2442 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2443 { LEN_AND_STR ("scopes"), "display scope information",
2445 { LEN_AND_STR ("all"), "all previous options combined",
2446 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2447 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS
2448 | DL_DEBUG_SCOPES },
2449 { LEN_AND_STR ("statistics"), "display relocation statistics",
2450 DL_DEBUG_STATISTICS },
2451 { LEN_AND_STR ("unused"), "determined unused DSOs",
2453 { LEN_AND_STR ("help"), "display this help message and exit",
2456 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2458 /* Skip separating white spaces and commas. */
2459 while (*dl_debug != '\0')
2461 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2466 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2467 && dl_debug[len] != ',' && dl_debug[len] != ':')
2470 for (cnt = 0; cnt < ndebopts; ++cnt)
2471 if (debopts[cnt].len == len
2472 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2474 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2479 if (cnt == ndebopts)
2481 /* Display a warning and skip everything until next
2483 char *copy = strndupa (dl_debug, len);
2484 _dl_error_printf ("\
2485 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2495 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2500 Valid options for the LD_DEBUG environment variable are:\n\n");
2502 for (cnt = 0; cnt < ndebopts; ++cnt)
2503 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2504 " " + debopts[cnt].len - 3,
2505 debopts[cnt].helptext);
2508 To direct the debugging output into a file instead of standard output\n\
2509 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2515 process_dl_audit (char *str)
2517 /* The parameter is a colon separated list of DSO names. */
2520 while ((p = (strsep) (&str, ":")) != NULL)
2522 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2523 || strchr (p, '/') == NULL))
2525 /* This is using the local malloc, not the system malloc. The
2526 memory can never be freed. */
2527 struct audit_list *newp = malloc (sizeof (*newp));
2530 if (audit_list == NULL)
2531 audit_list = newp->next = newp;
2534 newp->next = audit_list->next;
2535 audit_list = audit_list->next = newp;
2540 /* Process all environments variables the dynamic linker must recognize.
2541 Since all of them start with `LD_' we are a bit smarter while finding
2543 extern char **_environ attribute_hidden;
2547 process_envvars (enum mode *modep)
2549 char **runp = _environ;
2551 enum mode mode = normal;
2552 char *debug_output = NULL;
2554 /* This is the default place for profiling data file. */
2555 GLRO(dl_profile_output)
2556 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2558 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2562 while (envline[len] != '\0' && envline[len] != '=')
2565 if (envline[len] != '=')
2566 /* This is a "LD_" variable at the end of the string without
2567 a '=' character. Ignore it since otherwise we will access
2568 invalid memory below. */
2574 /* Warning level, verbose or not. */
2575 if (memcmp (envline, "WARN", 4) == 0)
2576 GLRO(dl_verbose) = envline[5] != '\0';
2580 /* Debugging of the dynamic linker? */
2581 if (memcmp (envline, "DEBUG", 5) == 0)
2583 process_dl_debug (&envline[6]);
2586 if (memcmp (envline, "AUDIT", 5) == 0)
2587 process_dl_audit (&envline[6]);
2591 /* Print information about versions. */
2592 if (memcmp (envline, "VERBOSE", 7) == 0)
2594 version_info = envline[8] != '\0';
2598 /* List of objects to be preloaded. */
2599 if (memcmp (envline, "PRELOAD", 7) == 0)
2601 preloadlist = &envline[8];
2605 /* Which shared object shall be profiled. */
2606 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2607 GLRO(dl_profile) = &envline[8];
2611 /* Do we bind early? */
2612 if (memcmp (envline, "BIND_NOW", 8) == 0)
2614 GLRO(dl_lazy) = envline[9] == '\0';
2617 if (memcmp (envline, "BIND_NOT", 8) == 0)
2618 GLRO(dl_bind_not) = envline[9] != '\0';
2622 /* Test whether we want to see the content of the auxiliary
2623 array passed up from the kernel. */
2624 if (!INTUSE(__libc_enable_secure)
2625 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2630 /* Mask for the important hardware capabilities. */
2631 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2632 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2637 /* Path where the binary is found. */
2638 if (!INTUSE(__libc_enable_secure)
2639 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2640 GLRO(dl_origin_path) = &envline[12];
2644 /* The library search path. */
2645 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2647 library_path = &envline[13];
2651 /* Where to place the profiling data file. */
2652 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2654 debug_output = &envline[13];
2658 if (!INTUSE(__libc_enable_secure)
2659 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2660 GLRO(dl_dynamic_weak) = 1;
2664 /* We might have some extra environment variable with length 13
2666 #ifdef EXTRA_LD_ENVVARS_13
2669 if (!INTUSE(__libc_enable_secure)
2670 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2672 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2676 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2677 GLRO(dl_pointer_guard) = envline[14] != '0';
2681 /* Where to place the profiling data file. */
2682 if (!INTUSE(__libc_enable_secure)
2683 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2684 && envline[15] != '\0')
2685 GLRO(dl_profile_output) = &envline[15];
2689 /* The mode of the dynamic linker can be set. */
2690 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2693 GLRO(dl_verbose) = 1;
2694 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2695 GLRO(dl_trace_prelink) = &envline[17];
2700 /* The mode of the dynamic linker can be set. */
2701 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2705 /* We might have some extra environment variable to handle. This
2706 is tricky due to the pre-processing of the length of the name
2707 in the switch statement here. The code here assumes that added
2708 environment variables have a different length. */
2709 #ifdef EXTRA_LD_ENVVARS
2715 /* The caller wants this information. */
2718 /* Extra security for SUID binaries. Remove all dangerous environment
2720 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2722 static const char unsecure_envvars[] =
2723 #ifdef EXTRA_UNSECURE_ENVVARS
2724 EXTRA_UNSECURE_ENVVARS
2729 nextp = unsecure_envvars;
2733 /* We could use rawmemchr but this need not be fast. */
2734 nextp = (char *) (strchr) (nextp, '\0') + 1;
2736 while (*nextp != '\0');
2738 if (__access ("/etc/suid-debug", F_OK) != 0)
2740 unsetenv ("MALLOC_CHECK_");
2741 GLRO(dl_debug_mask) = 0;
2747 /* If we have to run the dynamic linker in debugging mode and the
2748 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2749 messages to this file. */
2750 else if (any_debug && debug_output != NULL)
2753 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2755 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2757 size_t name_len = strlen (debug_output);
2758 char buf[name_len + 12];
2761 buf[name_len + 11] = '\0';
2762 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2764 startp = memcpy (startp - name_len, debug_output, name_len);
2766 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2767 if (GLRO(dl_debug_fd) == -1)
2768 /* We use standard output if opening the file failed. */
2769 GLRO(dl_debug_fd) = STDOUT_FILENO;
2774 /* Print the various times we collected. */
2776 __attribute ((noinline))
2777 print_statistics (hp_timing_t *rtld_total_timep)
2779 #ifndef HP_TIMING_NONAVAIL
2784 /* Total time rtld used. */
2785 if (HP_TIMING_AVAIL)
2787 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2788 _dl_debug_printf ("\nruntime linker statistics:\n"
2789 " total startup time in dynamic loader: %s\n", buf);
2791 /* Print relocation statistics. */
2793 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2794 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2795 pbuf + sizeof (pbuf), 10, 0);
2797 switch (pbuf + sizeof (pbuf) - cp)
2808 _dl_debug_printf ("\
2809 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2813 unsigned long int num_relative_relocations = 0;
2814 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2816 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2819 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2821 for (unsigned int i = 0; i < scope->r_nlist; i++)
2823 struct link_map *l = scope->r_list [i];
2825 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2826 num_relative_relocations
2827 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2828 #ifndef ELF_MACHINE_REL_RELATIVE
2829 /* Relative relocations are processed on these architectures if
2830 library is loaded to different address than p_vaddr or
2831 if not prelinked. */
2832 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2833 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2835 /* On e.g. IA-64 or Alpha, relative relocations are processed
2836 only if library is loaded to different address than p_vaddr. */
2837 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2839 num_relative_relocations
2840 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2844 _dl_debug_printf (" number of relocations: %lu\n"
2845 " number of relocations from cache: %lu\n"
2846 " number of relative relocations: %lu\n",
2847 GL(dl_num_relocations),
2848 GL(dl_num_cache_relocations),
2849 num_relative_relocations);
2851 #ifndef HP_TIMING_NONAVAIL
2852 /* Time spend while loading the object and the dependencies. */
2853 if (HP_TIMING_AVAIL)
2856 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2857 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2858 pbuf + sizeof (pbuf), 10, 0);
2860 switch (pbuf + sizeof (pbuf) - cp)
2871 _dl_debug_printf ("\
2872 time needed to load objects: %s (%s%%)\n",