Relocate hppa from ports to libc.
[glibc.git] / elf / rtld.c
blob9d121dc8f5f5cd799a148a0c48df74c0be230b57
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
19 #include <errno.h>
20 #include <dlfcn.h>
21 #include <fcntl.h>
22 #include <stdbool.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <sys/mman.h>
27 #include <sys/param.h>
28 #include <sys/stat.h>
29 #include <ldsodefs.h>
30 #include <_itoa.h>
31 #include <entry.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>
38 #include <dl-cache.h>
39 #include <dl-osinfo.h>
40 #include <dl-procinfo.h>
41 #include <tls.h>
42 #include <stap-probe.h>
43 #include <stackinfo.h>
45 #include <assert.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
73 all the entries. */
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;
81 #else
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;
85 #endif
86 INTDEF(_dl_argv)
88 #ifndef THREAD_SET_STACK_GUARD
89 /* Only exported for architectures that don't store the stack guard canary
90 in thread local area. */
91 uintptr_t __stack_chk_guard attribute_relro;
92 #endif
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)
100 #endif
103 /* List of auditing DSOs. */
104 static struct audit_list
106 const char *name;
107 struct audit_list *next;
108 } *audit_list;
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
117 never be called. */
118 int _dl_starting_up = 0;
119 INTVARDEF(_dl_starting_up)
120 #endif
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,
132 #endif
133 ._dl_nns = 1,
134 ._dl_ns =
136 #ifdef _LIBC_REENTRANT
137 [LM_ID_BASE] = { ._ns_unique_sym_table
138 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
139 #endif
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,
158 #endif
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,
163 ._dl_lazy = 1,
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
181 #endif
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
202 #endif
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;
209 #endif
211 /* Additional definitions needed by TLS initialization. */
212 #ifdef TLS_INIT_HELPER
213 TLS_INIT_HELPER
214 #endif
216 /* Helper function for syscall implementation. */
217 #ifdef DL_SYSINFO_IMPLEMENTATION
218 DL_SYSINFO_IMPLEMENTATION
219 #endif
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
226 hidden. */
227 #ifdef PI_STATIC_AND_HIDDEN
228 # define DONT_USE_BOOTSTRAP_MAP 1
229 #endif
231 #ifdef DONT_USE_BOOTSTRAP_MAP
232 static ElfW(Addr) _dl_start_final (void *arg);
233 #else
234 struct dl_start_final_info
236 struct link_map l;
237 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
238 hp_timing_t start_time;
239 #endif
241 static ElfW(Addr) _dl_start_final (void *arg,
242 struct dl_start_final_info *info);
243 #endif
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;
251 #ifdef RTLD_START
252 RTLD_START
253 #else
254 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
255 #endif
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)
266 #else
267 static ElfW(Addr) __attribute__ ((noinline))
268 _dl_start_final (void *arg, struct dl_start_final_info *info)
269 #endif
271 ElfW(Addr) start_addr;
273 if (HP_TIMING_AVAIL)
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
279 else
280 start_time = info->start_time;
281 #endif
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;
295 #endif
296 _dl_setup_hash (&GL(dl_rtld_map));
297 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
298 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
299 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
300 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
301 /* Copy the TLS related data if necessary. */
302 #ifndef DONT_USE_BOOTSTRAP_MAP
303 # if USE___THREAD
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;
312 # else
313 # if NO_TLS_OFFSET != 0
314 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
315 # endif
316 # endif
318 #endif
320 #if HP_TIMING_AVAIL
321 HP_TIMING_NOW (GL(dl_cpuclock_offset));
322 #endif
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;
335 if (HP_TIMING_AVAIL)
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);
345 #endif
347 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS))
349 #ifndef HP_TIMING_NONAVAIL
350 print_statistics (&rtld_total_time);
351 #else
352 print_statistics (NULL);
353 #endif
356 return start_addr;
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)
364 #else
365 struct dl_start_final_info info;
366 # define bootstrap_map info.l
367 #endif
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);
380 #else
381 HP_TIMING_NOW (info.start_time);
382 #endif
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));
393 # else
394 for (size_t cnt = 0;
395 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
396 ++cnt)
397 bootstrap_map.l_info[cnt] = 0;
398 # endif
399 # if USE___THREAD
400 bootstrap_map.l_tls_modid = 0;
401 # endif
402 #endif
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;
413 #endif
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. */
420 #if USE___THREAD
421 dtv_t initdtv[3];
422 ElfW(Ehdr) *ehdr
423 # ifdef DONT_USE_BOOTSTRAP_MAP
424 = (ElfW(Ehdr) *) &_begin;
425 # else
426 # error This will not work with prelink.
427 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
428 # endif
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. */
431 while (cnt-- > 0)
432 if (phdr[cnt].p_type == PT_TLS)
434 void *tlsblock;
435 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
436 char *p;
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;
442 else
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
453 time. */
454 # if TLS_TCB_AT_TP
455 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
456 TLS_INIT_TCB_ALIGN)
457 + TLS_INIT_TCB_SIZE
458 + max_align);
459 # elif TLS_DTV_AT_TP
460 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
461 bootstrap_map.l_tls_align)
462 + bootstrap_map.l_tls_blocksize
463 + max_align);
464 # else
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"
468 # endif
469 /* Align the TLS block. */
470 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
471 & ~(max_align - 1));
473 /* Initialize the dtv. [0] is the length, [1] the generation
474 counter. */
475 initdtv[0].counter = 1;
476 initdtv[1].counter = 0;
478 /* Initialize the TLS block. */
479 # if TLS_TCB_AT_TP
480 initdtv[2].pointer = tlsblock;
481 # elif TLS_DTV_AT_TP
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;
485 # else
486 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
487 # endif
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));
493 # else
495 size_t remaining = (bootstrap_map.l_tls_blocksize
496 - bootstrap_map.l_tls_initimage_size);
497 while (remaining-- > 0)
498 *p++ = '\0';
500 # endif
502 /* Install the pointer to the dtv. */
504 /* Initialize the thread pointer. */
505 # if TLS_TCB_AT_TP
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,
510 initdtv);
512 const char *lossage = TLS_INIT_TP ((char *) tlsblock
513 + bootstrap_map.l_tls_offset, 0);
514 # elif TLS_DTV_AT_TP
515 INSTALL_DTV (tlsblock, initdtv);
516 const char *lossage = TLS_INIT_TP (tlsblock, 0);
517 # else
518 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
519 # endif
520 if (__glibc_unlikely (lossage != NULL))
521 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
522 lossage);
524 /* So far this is module number one. */
525 bootstrap_map.l_tls_modid = 1;
527 /* There can only be one PT_TLS entry. */
528 break;
530 #endif /* USE___THREAD */
532 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
533 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
534 #endif
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);
558 #else
559 ElfW(Addr) entry = _dl_start_final (arg, &info);
560 #endif
562 #ifndef ELF_MACHINE_START_ADDRESS
563 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
564 #endif
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. */
578 struct relocate_args
580 struct link_map *l;
581 int reloc_mode;
584 struct map_args
586 /* Argument to map_doit. */
587 char *str;
588 struct link_map *loader;
589 int mode;
590 /* Return value of map_doit. */
591 struct link_map *map;
594 struct dlmopen_args
596 const char *fname;
597 struct link_map *map;
600 struct lookup_args
602 const char *name;
603 struct link_map *map;
604 void *result;
607 /* Arguments to version_check_doit. */
608 struct version_check_args
610 int doexit;
611 int dotrace;
614 static void
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);
622 static void
623 map_doit (void *a)
625 struct map_args *args = (struct map_args *) a;
626 int type = (args->mode == __RTLD_OPENEXEC) ? lt_executable : lt_library;
627 args->map = _dl_map_object (args->loader, args->str, type, 0,
628 args->mode, LM_ID_BASE);
631 static void
632 dlmopen_doit (void *a)
634 struct dlmopen_args *args = (struct dlmopen_args *) a;
635 args->map = _dl_open (args->fname,
636 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
637 | __RTLD_SECURE),
638 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
639 __environ);
642 static void
643 lookup_doit (void *a)
645 struct lookup_args *args = (struct lookup_args *) a;
646 const ElfW(Sym) *ref = NULL;
647 args->result = NULL;
648 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
649 args->map->l_local_scope, NULL, 0,
650 DL_LOOKUP_RETURN_NEWEST, NULL);
651 if (ref != NULL)
652 args->result = DL_SYMBOL_ADDRESS (l, ref);
655 static void
656 version_check_doit (void *a)
658 struct version_check_args *args = (struct version_check_args *) a;
659 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
660 args->dotrace) && args->doexit)
661 /* We cannot start the application. Abort now. */
662 _exit (1);
666 static inline struct link_map *
667 find_needed (const char *name)
669 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
670 unsigned int n = scope->r_nlist;
672 while (n-- > 0)
673 if (_dl_name_match_p (name, scope->r_list[n]))
674 return scope->r_list[n];
676 /* Should never happen. */
677 return NULL;
680 static int
681 match_version (const char *string, struct link_map *map)
683 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
684 ElfW(Verdef) *def;
686 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
687 if (map->l_info[VERDEFTAG] == NULL)
688 /* The file has no symbol versioning. */
689 return 0;
691 def = (ElfW(Verdef) *) ((char *) map->l_addr
692 + map->l_info[VERDEFTAG]->d_un.d_ptr);
693 while (1)
695 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
697 /* Compare the version strings. */
698 if (strcmp (string, strtab + aux->vda_name) == 0)
699 /* Bingo! */
700 return 1;
702 /* If no more definitions we failed to find what we want. */
703 if (def->vd_next == 0)
704 break;
706 /* Next definition. */
707 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
710 return 0;
713 static bool tls_init_tp_called;
715 static void *
716 init_tls (void)
718 /* Number of elements in the static TLS block. */
719 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
721 /* Do not do this twice. The audit interface might have required
722 the DTV interfaces to be set up early. */
723 if (GL(dl_initial_dtv) != NULL)
724 return NULL;
726 /* Allocate the array which contains the information about the
727 dtv slots. We allocate a few entries more than needed to
728 avoid the need for reallocation. */
729 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
731 /* Allocate. */
732 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
733 calloc (sizeof (struct dtv_slotinfo_list)
734 + nelem * sizeof (struct dtv_slotinfo), 1);
735 /* No need to check the return value. If memory allocation failed
736 the program would have been terminated. */
738 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
739 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
740 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
742 /* Fill in the information from the loaded modules. No namespace
743 but the base one can be filled at this time. */
744 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
745 int i = 0;
746 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
747 l = l->l_next)
748 if (l->l_tls_blocksize != 0)
750 /* This is a module with TLS data. Store the map reference.
751 The generation counter is zero. */
752 slotinfo[i].map = l;
753 /* slotinfo[i].gen = 0; */
754 ++i;
756 assert (i == GL(dl_tls_max_dtv_idx));
758 /* Compute the TLS offsets for the various blocks. */
759 _dl_determine_tlsoffset ();
761 /* Construct the static TLS block and the dtv for the initial
762 thread. For some platforms this will include allocating memory
763 for the thread descriptor. The memory for the TLS block will
764 never be freed. It should be allocated accordingly. The dtv
765 array can be changed if dynamic loading requires it. */
766 void *tcbp = _dl_allocate_tls_storage ();
767 if (tcbp == NULL)
768 _dl_fatal_printf ("\
769 cannot allocate TLS data structures for initial thread");
771 /* Store for detection of the special case by __tls_get_addr
772 so it knows not to pass this dtv to the normal realloc. */
773 GL(dl_initial_dtv) = GET_DTV (tcbp);
775 /* And finally install it for the main thread. If ld.so itself uses
776 TLS we know the thread pointer was initialized earlier. */
777 const char *lossage
778 #ifdef USE___THREAD
779 = TLS_INIT_TP (tcbp, USE___THREAD);
780 #else
781 = TLS_INIT_TP (tcbp, 0);
782 #endif
783 if (__glibc_unlikely (lossage != NULL))
784 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
785 tls_init_tp_called = true;
787 return tcbp;
790 #ifdef _LIBC_REENTRANT
791 /* _dl_error_catch_tsd points to this for the single-threaded case.
792 It's reset by the thread library for multithreaded programs. */
793 void ** __attribute__ ((const))
794 _dl_initial_error_catch_tsd (void)
796 static void *data;
797 return &data;
799 #endif
802 static unsigned int
803 do_preload (char *fname, struct link_map *main_map, const char *where)
805 const char *objname;
806 const char *err_str = NULL;
807 struct map_args args;
808 bool malloced;
810 args.str = fname;
811 args.loader = main_map;
812 args.mode = __RTLD_SECURE;
814 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
816 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
817 if (__glibc_unlikely (err_str != NULL))
819 _dl_error_printf ("\
820 ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n",
821 fname, where, err_str);
822 /* No need to call free, this is still before
823 the libc's malloc is used. */
825 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
826 /* It is no duplicate. */
827 return 1;
829 /* Nothing loaded. */
830 return 0;
833 #if defined SHARED && defined _LIBC_REENTRANT \
834 && defined __rtld_lock_default_lock_recursive
835 static void
836 rtld_lock_default_lock_recursive (void *lock)
838 __rtld_lock_default_lock_recursive (lock);
841 static void
842 rtld_lock_default_unlock_recursive (void *lock)
844 __rtld_lock_default_unlock_recursive (lock);
846 #endif
849 static void
850 security_init (void)
852 /* Set up the stack checker's canary. */
853 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
854 #ifdef THREAD_SET_STACK_GUARD
855 THREAD_SET_STACK_GUARD (stack_chk_guard);
856 #else
857 __stack_chk_guard = stack_chk_guard;
858 #endif
860 /* Set up the pointer guard as well, if necessary. */
861 if (GLRO(dl_pointer_guard))
863 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
864 stack_chk_guard);
865 #ifdef THREAD_SET_POINTER_GUARD
866 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
867 #endif
868 __pointer_chk_guard_local = pointer_chk_guard;
871 /* We do not need the _dl_random value anymore. The less
872 information we leave behind, the better, so clear the
873 variable. */
874 _dl_random = NULL;
877 #include "setup-vdso.h"
879 /* The library search path. */
880 static const char *library_path attribute_relro;
881 /* The list preloaded objects. */
882 static const char *preloadlist attribute_relro;
883 /* Nonzero if information about versions has to be printed. */
884 static int version_info attribute_relro;
886 static void
887 dl_main (const ElfW(Phdr) *phdr,
888 ElfW(Word) phnum,
889 ElfW(Addr) *user_entry,
890 ElfW(auxv_t) *auxv)
892 const ElfW(Phdr) *ph;
893 enum mode mode;
894 struct link_map *main_map;
895 size_t file_size;
896 char *file;
897 bool has_interp = false;
898 unsigned int i;
899 bool prelinked = false;
900 bool rtld_is_main = false;
901 #ifndef HP_TIMING_NONAVAIL
902 hp_timing_t start;
903 hp_timing_t stop;
904 hp_timing_t diff;
905 #endif
906 void *tcbp = NULL;
908 #ifdef _LIBC_REENTRANT
909 /* Explicit initialization since the reloc would just be more work. */
910 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
911 #endif
913 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
915 #if defined SHARED && defined _LIBC_REENTRANT \
916 && defined __rtld_lock_default_lock_recursive
917 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
918 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
919 #endif
921 /* The explicit initialization here is cheaper than processing the reloc
922 in the _rtld_local definition's initializer. */
923 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
925 /* Process the environment variable which control the behaviour. */
926 process_envvars (&mode);
928 #ifndef HAVE_INLINED_SYSCALLS
929 /* Set up a flag which tells we are just starting. */
930 INTUSE(_dl_starting_up) = 1;
931 #endif
933 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
935 /* Ho ho. We are not the program interpreter! We are the program
936 itself! This means someone ran ld.so as a command. Well, that
937 might be convenient to do sometimes. We support it by
938 interpreting the args like this:
940 ld.so PROGRAM ARGS...
942 The first argument is the name of a file containing an ELF
943 executable we will load and run with the following arguments.
944 To simplify life here, PROGRAM is searched for using the
945 normal rules for shared objects, rather than $PATH or anything
946 like that. We just load it and use its entry point; we don't
947 pay attention to its PT_INTERP command (we are the interpreter
948 ourselves). This is an easy way to test a new ld.so before
949 installing it. */
950 rtld_is_main = true;
952 /* Note the place where the dynamic linker actually came from. */
953 GL(dl_rtld_map).l_name = rtld_progname;
955 while (_dl_argc > 1)
956 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
958 mode = list;
959 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
961 ++_dl_skip_args;
962 --_dl_argc;
963 ++INTUSE(_dl_argv);
965 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
967 mode = verify;
969 ++_dl_skip_args;
970 --_dl_argc;
971 ++INTUSE(_dl_argv);
973 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-cache"))
975 GLRO(dl_inhibit_cache) = 1;
976 ++_dl_skip_args;
977 --_dl_argc;
978 ++INTUSE(_dl_argv);
980 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
981 && _dl_argc > 2)
983 library_path = INTUSE(_dl_argv)[2];
985 _dl_skip_args += 2;
986 _dl_argc -= 2;
987 INTUSE(_dl_argv) += 2;
989 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
990 && _dl_argc > 2)
992 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
994 _dl_skip_args += 2;
995 _dl_argc -= 2;
996 INTUSE(_dl_argv) += 2;
998 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
1000 process_dl_audit (INTUSE(_dl_argv)[2]);
1002 _dl_skip_args += 2;
1003 _dl_argc -= 2;
1004 INTUSE(_dl_argv) += 2;
1006 else
1007 break;
1009 /* If we have no further argument the program was called incorrectly.
1010 Grant the user some education. */
1011 if (_dl_argc < 2)
1012 _dl_fatal_printf ("\
1013 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1014 You have invoked `ld.so', the helper program for shared library executables.\n\
1015 This program usually lives in the file `/lib/ld.so', and special directives\n\
1016 in executable files using ELF shared libraries tell the system's program\n\
1017 loader to load the helper program from this file. This helper program loads\n\
1018 the shared libraries needed by the program executable, prepares the program\n\
1019 to run, and runs it. You may invoke this helper program directly from the\n\
1020 command line to load and run an ELF executable file; this is like executing\n\
1021 that file itself, but always uses this helper program from the file you\n\
1022 specified, instead of the helper program file specified in the executable\n\
1023 file you run. This is mostly of use for maintainers to test new versions\n\
1024 of this helper program; chances are you did not intend to run this program.\n\
1026 --list list all dependencies and how they are resolved\n\
1027 --verify verify that given object really is a dynamically linked\n\
1028 object we can handle\n\
1029 --inhibit-cache Do not use " LD_SO_CACHE "\n\
1030 --library-path PATH use given PATH instead of content of the environment\n\
1031 variable LD_LIBRARY_PATH\n\
1032 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1033 in LIST\n\
1034 --audit LIST use objects named in LIST as auditors\n");
1036 ++_dl_skip_args;
1037 --_dl_argc;
1038 ++INTUSE(_dl_argv);
1040 /* The initialization of _dl_stack_flags done below assumes the
1041 executable's PT_GNU_STACK may have been honored by the kernel, and
1042 so a PT_GNU_STACK with PF_X set means the stack started out with
1043 execute permission. However, this is not really true if the
1044 dynamic linker is the executable the kernel loaded. For this
1045 case, we must reinitialize _dl_stack_flags to match the dynamic
1046 linker itself. If the dynamic linker was built with a
1047 PT_GNU_STACK, then the kernel may have loaded us with a
1048 nonexecutable stack that we will have to make executable when we
1049 load the program below unless it has a PT_GNU_STACK indicating
1050 nonexecutable stack is ok. */
1052 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1053 if (ph->p_type == PT_GNU_STACK)
1055 GL(dl_stack_flags) = ph->p_flags;
1056 break;
1059 if (__builtin_expect (mode, normal) == verify)
1061 const char *objname;
1062 const char *err_str = NULL;
1063 struct map_args args;
1064 bool malloced;
1066 args.str = rtld_progname;
1067 args.loader = NULL;
1068 args.mode = __RTLD_OPENEXEC;
1069 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1070 &args);
1071 if (__glibc_unlikely (err_str != NULL))
1072 /* We don't free the returned string, the programs stops
1073 anyway. */
1074 _exit (EXIT_FAILURE);
1076 else
1078 HP_TIMING_NOW (start);
1079 _dl_map_object (NULL, rtld_progname, lt_executable, 0,
1080 __RTLD_OPENEXEC, LM_ID_BASE);
1081 HP_TIMING_NOW (stop);
1083 HP_TIMING_DIFF (load_time, start, stop);
1086 /* Now the map for the main executable is available. */
1087 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1089 if (__builtin_expect (mode, normal) == normal
1090 && GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1091 && main_map->l_info[DT_SONAME] != NULL
1092 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1093 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val,
1094 (const char *) D_PTR (main_map, l_info[DT_STRTAB])
1095 + main_map->l_info[DT_SONAME]->d_un.d_val) == 0)
1096 _dl_fatal_printf ("loader cannot load itself\n");
1098 phdr = main_map->l_phdr;
1099 phnum = main_map->l_phnum;
1100 /* We overwrite here a pointer to a malloc()ed string. But since
1101 the malloc() implementation used at this point is the dummy
1102 implementations which has no real free() function it does not
1103 makes sense to free the old string first. */
1104 main_map->l_name = (char *) "";
1105 *user_entry = main_map->l_entry;
1107 #ifdef HAVE_AUX_VECTOR
1108 /* Adjust the on-stack auxiliary vector so that it looks like the
1109 binary was executed directly. */
1110 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1111 switch (av->a_type)
1113 case AT_PHDR:
1114 av->a_un.a_val = (uintptr_t) phdr;
1115 break;
1116 case AT_PHNUM:
1117 av->a_un.a_val = phnum;
1118 break;
1119 case AT_ENTRY:
1120 av->a_un.a_val = *user_entry;
1121 break;
1122 case AT_EXECFN:
1123 av->a_un.a_val = (uintptr_t) _dl_argv[0];
1124 break;
1126 #endif
1128 else
1130 /* Create a link_map for the executable itself.
1131 This will be what dlopen on "" returns. */
1132 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1133 __RTLD_OPENEXEC, LM_ID_BASE);
1134 assert (main_map != NULL);
1135 main_map->l_phdr = phdr;
1136 main_map->l_phnum = phnum;
1137 main_map->l_entry = *user_entry;
1139 /* Even though the link map is not yet fully initialized we can add
1140 it to the map list since there are no possible users running yet. */
1141 _dl_add_to_namespace_list (main_map, LM_ID_BASE);
1142 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1144 /* At this point we are in a bit of trouble. We would have to
1145 fill in the values for l_dev and l_ino. But in general we
1146 do not know where the file is. We also do not handle AT_EXECFD
1147 even if it would be passed up.
1149 We leave the values here defined to 0. This is normally no
1150 problem as the program code itself is normally no shared
1151 object and therefore cannot be loaded dynamically. Nothing
1152 prevent the use of dynamic binaries and in these situations
1153 we might get problems. We might not be able to find out
1154 whether the object is already loaded. But since there is no
1155 easy way out and because the dynamic binary must also not
1156 have an SONAME we ignore this program for now. If it becomes
1157 a problem we can force people using SONAMEs. */
1159 /* We delay initializing the path structure until we got the dynamic
1160 information for the program. */
1163 main_map->l_map_end = 0;
1164 main_map->l_text_end = 0;
1165 /* Perhaps the executable has no PT_LOAD header entries at all. */
1166 main_map->l_map_start = ~0;
1167 /* And it was opened directly. */
1168 ++main_map->l_direct_opencount;
1170 /* Scan the program header table for the dynamic section. */
1171 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1172 switch (ph->p_type)
1174 case PT_PHDR:
1175 /* Find out the load address. */
1176 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1177 break;
1178 case PT_DYNAMIC:
1179 /* This tells us where to find the dynamic section,
1180 which tells us everything we need to do. */
1181 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1182 break;
1183 case PT_INTERP:
1184 /* This "interpreter segment" was used by the program loader to
1185 find the program interpreter, which is this program itself, the
1186 dynamic linker. We note what name finds us, so that a future
1187 dlopen call or DT_NEEDED entry, for something that wants to link
1188 against the dynamic linker as a shared library, will know that
1189 the shared object is already loaded. */
1190 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1191 + ph->p_vaddr);
1192 /* _dl_rtld_libname.next = NULL; Already zero. */
1193 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1195 /* Ordinarilly, we would get additional names for the loader from
1196 our DT_SONAME. This can't happen if we were actually linked as
1197 a static executable (detect this case when we have no DYNAMIC).
1198 If so, assume the filename component of the interpreter path to
1199 be our SONAME, and add it to our name list. */
1200 if (GL(dl_rtld_map).l_ld == NULL)
1202 const char *p = NULL;
1203 const char *cp = _dl_rtld_libname.name;
1205 /* Find the filename part of the path. */
1206 while (*cp != '\0')
1207 if (*cp++ == '/')
1208 p = cp;
1210 if (p != NULL)
1212 _dl_rtld_libname2.name = p;
1213 /* _dl_rtld_libname2.next = NULL; Already zero. */
1214 _dl_rtld_libname.next = &_dl_rtld_libname2;
1218 has_interp = true;
1219 break;
1220 case PT_LOAD:
1222 ElfW(Addr) mapstart;
1223 ElfW(Addr) allocend;
1225 /* Remember where the main program starts in memory. */
1226 mapstart = (main_map->l_addr
1227 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1228 if (main_map->l_map_start > mapstart)
1229 main_map->l_map_start = mapstart;
1231 /* Also where it ends. */
1232 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1233 if (main_map->l_map_end < allocend)
1234 main_map->l_map_end = allocend;
1235 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1236 main_map->l_text_end = allocend;
1238 break;
1240 case PT_TLS:
1241 if (ph->p_memsz > 0)
1243 /* Note that in the case the dynamic linker we duplicate work
1244 here since we read the PT_TLS entry already in
1245 _dl_start_final. But the result is repeatable so do not
1246 check for this special but unimportant case. */
1247 main_map->l_tls_blocksize = ph->p_memsz;
1248 main_map->l_tls_align = ph->p_align;
1249 if (ph->p_align == 0)
1250 main_map->l_tls_firstbyte_offset = 0;
1251 else
1252 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1253 & (ph->p_align - 1));
1254 main_map->l_tls_initimage_size = ph->p_filesz;
1255 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1257 /* This image gets the ID one. */
1258 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1260 break;
1262 case PT_GNU_STACK:
1263 GL(dl_stack_flags) = ph->p_flags;
1264 break;
1266 case PT_GNU_RELRO:
1267 main_map->l_relro_addr = ph->p_vaddr;
1268 main_map->l_relro_size = ph->p_memsz;
1269 break;
1272 /* Adjust the address of the TLS initialization image in case
1273 the executable is actually an ET_DYN object. */
1274 if (main_map->l_tls_initimage != NULL)
1275 main_map->l_tls_initimage
1276 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1277 if (! main_map->l_map_end)
1278 main_map->l_map_end = ~0;
1279 if (! main_map->l_text_end)
1280 main_map->l_text_end = ~0;
1281 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1283 /* We were invoked directly, so the program might not have a
1284 PT_INTERP. */
1285 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1286 /* _dl_rtld_libname.next = NULL; Already zero. */
1287 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1289 else
1290 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1292 /* If the current libname is different from the SONAME, add the
1293 latter as well. */
1294 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1295 && strcmp (GL(dl_rtld_map).l_libname->name,
1296 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1297 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1299 static struct libname_list newname;
1300 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1301 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1302 newname.next = NULL;
1303 newname.dont_free = 1;
1305 assert (GL(dl_rtld_map).l_libname->next == NULL);
1306 GL(dl_rtld_map).l_libname->next = &newname;
1308 /* The ld.so must be relocated since otherwise loading audit modules
1309 will fail since they reuse the very same ld.so. */
1310 assert (GL(dl_rtld_map).l_relocated);
1312 if (! rtld_is_main)
1314 /* Extract the contents of the dynamic section for easy access. */
1315 elf_get_dynamic_info (main_map, NULL);
1316 /* Set up our cache of pointers into the hash table. */
1317 _dl_setup_hash (main_map);
1320 if (__builtin_expect (mode, normal) == verify)
1322 /* We were called just to verify that this is a dynamic
1323 executable using us as the program interpreter. Exit with an
1324 error if we were not able to load the binary or no interpreter
1325 is specified (i.e., this is no dynamically linked binary. */
1326 if (main_map->l_ld == NULL)
1327 _exit (1);
1329 /* We allow here some platform specific code. */
1330 #ifdef DISTINGUISH_LIB_VERSIONS
1331 DISTINGUISH_LIB_VERSIONS;
1332 #endif
1333 _exit (has_interp ? 0 : 2);
1336 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1337 /* Set up the data structures for the system-supplied DSO early,
1338 so they can influence _dl_init_paths. */
1339 setup_vdso (main_map, &first_preload);
1341 #ifdef DL_SYSDEP_OSCHECK
1342 DL_SYSDEP_OSCHECK (_dl_fatal_printf);
1343 #endif
1345 /* Initialize the data structures for the search paths for shared
1346 objects. */
1347 _dl_init_paths (library_path);
1349 /* Initialize _r_debug. */
1350 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1351 LM_ID_BASE);
1352 r->r_state = RT_CONSISTENT;
1354 /* Put the link_map for ourselves on the chain so it can be found by
1355 name. Note that at this point the global chain of link maps contains
1356 exactly one element, which is pointed to by dl_loaded. */
1357 if (! GL(dl_rtld_map).l_name)
1358 /* If not invoked directly, the dynamic linker shared object file was
1359 found by the PT_INTERP name. */
1360 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1361 GL(dl_rtld_map).l_type = lt_library;
1362 main_map->l_next = &GL(dl_rtld_map);
1363 GL(dl_rtld_map).l_prev = main_map;
1364 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1365 ++GL(dl_load_adds);
1367 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1368 to not using bias for non-prelinked PIEs and libraries
1369 and using it for executables or prelinked PIEs or libraries. */
1370 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1371 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1373 /* Set up the program header information for the dynamic linker
1374 itself. It is needed in the dl_iterate_phdr callbacks. */
1375 const ElfW(Ehdr) *rtld_ehdr;
1377 /* Starting from binutils-2.23, the linker will define the magic symbol
1378 __ehdr_start to point to our own ELF header if it is visible in a
1379 segment that also includes the phdrs. If that's not available, we use
1380 the old method that assumes the beginning of the file is part of the
1381 lowest-addressed PT_LOAD segment. */
1382 #ifdef HAVE_EHDR_START
1383 extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
1384 rtld_ehdr = &__ehdr_start;
1385 #else
1386 rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
1387 #endif
1388 assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr);
1389 assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr)));
1391 const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff;
1393 GL(dl_rtld_map).l_phdr = rtld_phdr;
1394 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1397 /* PT_GNU_RELRO is usually the last phdr. */
1398 size_t cnt = rtld_ehdr->e_phnum;
1399 while (cnt-- > 0)
1400 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1402 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1403 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1404 break;
1407 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1408 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1409 /* Assign a module ID. Do this before loading any audit modules. */
1410 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1412 /* If we have auditing DSOs to load, do it now. */
1413 if (__glibc_unlikely (audit_list != NULL))
1415 /* Iterate over all entries in the list. The order is important. */
1416 struct audit_ifaces *last_audit = NULL;
1417 struct audit_list *al = audit_list->next;
1419 /* Since we start using the auditing DSOs right away we need to
1420 initialize the data structures now. */
1421 tcbp = init_tls ();
1423 /* Initialize security features. We need to do it this early
1424 since otherwise the constructors of the audit libraries will
1425 use different values (especially the pointer guard) and will
1426 fail later on. */
1427 security_init ();
1431 int tls_idx = GL(dl_tls_max_dtv_idx);
1433 /* Now it is time to determine the layout of the static TLS
1434 block and allocate it for the initial thread. Note that we
1435 always allocate the static block, we never defer it even if
1436 no DF_STATIC_TLS bit is set. The reason is that we know
1437 glibc will use the static model. */
1438 struct dlmopen_args dlmargs;
1439 dlmargs.fname = al->name;
1440 dlmargs.map = NULL;
1442 const char *objname;
1443 const char *err_str = NULL;
1444 bool malloced;
1445 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1446 &dlmargs);
1447 if (__glibc_unlikely (err_str != NULL))
1449 not_loaded:
1450 _dl_error_printf ("\
1451 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1452 al->name, err_str);
1453 if (malloced)
1454 free ((char *) err_str);
1456 else
1458 struct lookup_args largs;
1459 largs.name = "la_version";
1460 largs.map = dlmargs.map;
1462 /* Check whether the interface version matches. */
1463 (void) _dl_catch_error (&objname, &err_str, &malloced,
1464 lookup_doit, &largs);
1466 unsigned int (*laversion) (unsigned int);
1467 unsigned int lav;
1468 if (err_str == NULL
1469 && (laversion = largs.result) != NULL
1470 && (lav = laversion (LAV_CURRENT)) > 0
1471 && lav <= LAV_CURRENT)
1473 /* Allocate structure for the callback function pointers.
1474 This call can never fail. */
1475 union
1477 struct audit_ifaces ifaces;
1478 #define naudit_ifaces 8
1479 void (*fptr[naudit_ifaces]) (void);
1480 } *newp = malloc (sizeof (*newp));
1482 /* Names of the auditing interfaces. All in one
1483 long string. */
1484 static const char audit_iface_names[] =
1485 "la_activity\0"
1486 "la_objsearch\0"
1487 "la_objopen\0"
1488 "la_preinit\0"
1489 #if __ELF_NATIVE_CLASS == 32
1490 "la_symbind32\0"
1491 #elif __ELF_NATIVE_CLASS == 64
1492 "la_symbind64\0"
1493 #else
1494 # error "__ELF_NATIVE_CLASS must be defined"
1495 #endif
1496 #define STRING(s) __STRING (s)
1497 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1498 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1499 "la_objclose\0";
1500 unsigned int cnt = 0;
1501 const char *cp = audit_iface_names;
1504 largs.name = cp;
1505 (void) _dl_catch_error (&objname, &err_str, &malloced,
1506 lookup_doit, &largs);
1508 /* Store the pointer. */
1509 if (err_str == NULL && largs.result != NULL)
1511 newp->fptr[cnt] = largs.result;
1513 /* The dynamic linker link map is statically
1514 allocated, initialize the data now. */
1515 GL(dl_rtld_map).l_audit[cnt].cookie
1516 = (intptr_t) &GL(dl_rtld_map);
1518 else
1519 newp->fptr[cnt] = NULL;
1520 ++cnt;
1522 cp = (char *) rawmemchr (cp, '\0') + 1;
1524 while (*cp != '\0');
1525 assert (cnt == naudit_ifaces);
1527 /* Now append the new auditing interface to the list. */
1528 newp->ifaces.next = NULL;
1529 if (last_audit == NULL)
1530 last_audit = GLRO(dl_audit) = &newp->ifaces;
1531 else
1532 last_audit = last_audit->next = &newp->ifaces;
1533 ++GLRO(dl_naudit);
1535 /* Mark the DSO as being used for auditing. */
1536 dlmargs.map->l_auditing = 1;
1538 else
1540 /* We cannot use the DSO, it does not have the
1541 appropriate interfaces or it expects something
1542 more recent. */
1543 #ifndef NDEBUG
1544 Lmid_t ns = dlmargs.map->l_ns;
1545 #endif
1546 _dl_close (dlmargs.map);
1548 /* Make sure the namespace has been cleared entirely. */
1549 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1550 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1552 GL(dl_tls_max_dtv_idx) = tls_idx;
1553 goto not_loaded;
1557 al = al->next;
1559 while (al != audit_list->next);
1561 /* If we have any auditing modules, announce that we already
1562 have two objects loaded. */
1563 if (__glibc_unlikely (GLRO(dl_naudit) > 0))
1565 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1567 for (unsigned int outer = 0; outer < 2; ++outer)
1569 struct audit_ifaces *afct = GLRO(dl_audit);
1570 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1572 if (afct->objopen != NULL)
1574 ls[outer]->l_audit[cnt].bindflags
1575 = afct->objopen (ls[outer], LM_ID_BASE,
1576 &ls[outer]->l_audit[cnt].cookie);
1578 ls[outer]->l_audit_any_plt
1579 |= ls[outer]->l_audit[cnt].bindflags != 0;
1582 afct = afct->next;
1588 /* Keep track of the currently loaded modules to count how many
1589 non-audit modules which use TLS are loaded. */
1590 size_t count_modids = _dl_count_modids ();
1592 /* Set up debugging before the debugger is notified for the first time. */
1593 #ifdef ELF_MACHINE_DEBUG_SETUP
1594 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1595 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1596 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1597 #else
1598 if (main_map->l_info[DT_DEBUG] != NULL)
1599 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1600 with the run-time address of the r_debug structure */
1601 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1603 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1604 case you run gdb on the dynamic linker directly. */
1605 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1606 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1607 #endif
1609 /* We start adding objects. */
1610 r->r_state = RT_ADD;
1611 _dl_debug_state ();
1612 LIBC_PROBE (init_start, 2, LM_ID_BASE, r);
1614 /* Auditing checkpoint: we are ready to signal that the initial map
1615 is being constructed. */
1616 if (__glibc_unlikely (GLRO(dl_naudit) > 0))
1618 struct audit_ifaces *afct = GLRO(dl_audit);
1619 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1621 if (afct->activity != NULL)
1622 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1624 afct = afct->next;
1628 /* We have two ways to specify objects to preload: via environment
1629 variable and via the file /etc/ld.so.preload. The latter can also
1630 be used when security is enabled. */
1631 assert (*first_preload == NULL);
1632 struct link_map **preloads = NULL;
1633 unsigned int npreloads = 0;
1635 if (__glibc_unlikely (preloadlist != NULL))
1637 /* The LD_PRELOAD environment variable gives list of libraries
1638 separated by white space or colons that are loaded before the
1639 executable's dependencies and prepended to the global scope
1640 list. If the binary is running setuid all elements
1641 containing a '/' are ignored since it is insecure. */
1642 char *list = strdupa (preloadlist);
1643 char *p;
1645 HP_TIMING_NOW (start);
1647 /* Prevent optimizing strsep. Speed is not important here. */
1648 while ((p = (strsep) (&list, " :")) != NULL)
1649 if (p[0] != '\0'
1650 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1651 || strchr (p, '/') == NULL))
1652 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1654 HP_TIMING_NOW (stop);
1655 HP_TIMING_DIFF (diff, start, stop);
1656 HP_TIMING_ACCUM_NT (load_time, diff);
1659 /* There usually is no ld.so.preload file, it should only be used
1660 for emergencies and testing. So the open call etc should usually
1661 fail. Using access() on a non-existing file is faster than using
1662 open(). So we do this first. If it succeeds we do almost twice
1663 the work but this does not matter, since it is not for production
1664 use. */
1665 static const char preload_file[] = "/etc/ld.so.preload";
1666 if (__glibc_unlikely (__access (preload_file, R_OK) == 0))
1668 /* Read the contents of the file. */
1669 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1670 PROT_READ | PROT_WRITE);
1671 if (__glibc_unlikely (file != MAP_FAILED))
1673 /* Parse the file. It contains names of libraries to be loaded,
1674 separated by white spaces or `:'. It may also contain
1675 comments introduced by `#'. */
1676 char *problem;
1677 char *runp;
1678 size_t rest;
1680 /* Eliminate comments. */
1681 runp = file;
1682 rest = file_size;
1683 while (rest > 0)
1685 char *comment = memchr (runp, '#', rest);
1686 if (comment == NULL)
1687 break;
1689 rest -= comment - runp;
1691 *comment = ' ';
1692 while (--rest > 0 && *++comment != '\n');
1695 /* We have one problematic case: if we have a name at the end of
1696 the file without a trailing terminating characters, we cannot
1697 place the \0. Handle the case separately. */
1698 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1699 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1701 problem = &file[file_size];
1702 while (problem > file && problem[-1] != ' '
1703 && problem[-1] != '\t'
1704 && problem[-1] != '\n' && problem[-1] != ':')
1705 --problem;
1707 if (problem > file)
1708 problem[-1] = '\0';
1710 else
1712 problem = NULL;
1713 file[file_size - 1] = '\0';
1716 HP_TIMING_NOW (start);
1718 if (file != problem)
1720 char *p;
1721 runp = file;
1722 while ((p = strsep (&runp, ": \t\n")) != NULL)
1723 if (p[0] != '\0')
1724 npreloads += do_preload (p, main_map, preload_file);
1727 if (problem != NULL)
1729 char *p = strndupa (problem, file_size - (problem - file));
1731 npreloads += do_preload (p, main_map, preload_file);
1734 HP_TIMING_NOW (stop);
1735 HP_TIMING_DIFF (diff, start, stop);
1736 HP_TIMING_ACCUM_NT (load_time, diff);
1738 /* We don't need the file anymore. */
1739 __munmap (file, file_size);
1743 if (__glibc_unlikely (*first_preload != NULL))
1745 /* Set up PRELOADS with a vector of the preloaded libraries. */
1746 struct link_map *l = *first_preload;
1747 preloads = __alloca (npreloads * sizeof preloads[0]);
1748 i = 0;
1751 preloads[i++] = l;
1752 l = l->l_next;
1753 } while (l);
1754 assert (i == npreloads);
1757 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1758 specified some libraries to load, these are inserted before the actual
1759 dependencies in the executable's searchlist for symbol resolution. */
1760 HP_TIMING_NOW (start);
1761 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1762 HP_TIMING_NOW (stop);
1763 HP_TIMING_DIFF (diff, start, stop);
1764 HP_TIMING_ACCUM_NT (load_time, diff);
1766 /* Mark all objects as being in the global scope. */
1767 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1768 main_map->l_searchlist.r_list[--i]->l_global = 1;
1770 /* Remove _dl_rtld_map from the chain. */
1771 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1772 if (GL(dl_rtld_map).l_next != NULL)
1773 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1775 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1776 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1777 break;
1779 bool rtld_multiple_ref = false;
1780 if (__glibc_likely (i < main_map->l_searchlist.r_nlist))
1782 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1783 put it back in the list of visible objects. We insert it into the
1784 chain in symbol search order because gdb uses the chain's order as
1785 its symbol search order. */
1786 rtld_multiple_ref = true;
1788 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1789 if (__builtin_expect (mode, normal) == normal)
1791 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1792 ? main_map->l_searchlist.r_list[i + 1]
1793 : NULL);
1794 #ifdef NEED_DL_SYSINFO_DSO
1795 if (GLRO(dl_sysinfo_map) != NULL
1796 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1797 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1798 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1799 #endif
1801 else
1802 /* In trace mode there might be an invisible object (which we
1803 could not find) after the previous one in the search list.
1804 In this case it doesn't matter much where we put the
1805 interpreter object, so we just initialize the list pointer so
1806 that the assertion below holds. */
1807 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1809 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1810 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1811 if (GL(dl_rtld_map).l_next != NULL)
1813 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1814 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1818 /* Now let us see whether all libraries are available in the
1819 versions we need. */
1821 struct version_check_args args;
1822 args.doexit = mode == normal;
1823 args.dotrace = mode == trace;
1824 _dl_receive_error (print_missing_version, version_check_doit, &args);
1827 /* We do not initialize any of the TLS functionality unless any of the
1828 initial modules uses TLS. This makes dynamic loading of modules with
1829 TLS impossible, but to support it requires either eagerly doing setup
1830 now or lazily doing it later. Doing it now makes us incompatible with
1831 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1832 used. Trying to do it lazily is too hairy to try when there could be
1833 multiple threads (from a non-TLS-using libpthread). */
1834 bool was_tls_init_tp_called = tls_init_tp_called;
1835 if (tcbp == NULL)
1836 tcbp = init_tls ();
1838 if (__glibc_likely (audit_list == NULL))
1839 /* Initialize security features. But only if we have not done it
1840 earlier. */
1841 security_init ();
1843 if (__builtin_expect (mode, normal) != normal)
1845 /* We were run just to list the shared libraries. It is
1846 important that we do this before real relocation, because the
1847 functions we call below for output may no longer work properly
1848 after relocation. */
1849 struct link_map *l;
1851 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1853 struct r_scope_elem *scope = &main_map->l_searchlist;
1855 for (i = 0; i < scope->r_nlist; i++)
1857 l = scope->r_list [i];
1858 if (l->l_faked)
1860 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1861 continue;
1863 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1864 GLRO(dl_trace_prelink_map) = l;
1865 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1866 DSO_FILENAME (l->l_libname->name),
1867 DSO_FILENAME (l->l_name),
1868 (int) sizeof l->l_map_start * 2,
1869 (size_t) l->l_map_start,
1870 (int) sizeof l->l_addr * 2,
1871 (size_t) l->l_addr);
1873 if (l->l_tls_modid)
1874 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1875 (int) sizeof l->l_tls_offset * 2,
1876 (size_t) l->l_tls_offset);
1877 else
1878 _dl_printf ("\n");
1881 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1883 /* Look through the dependencies of the main executable
1884 and determine which of them is not actually
1885 required. */
1886 struct link_map *l = main_map;
1888 /* Relocate the main executable. */
1889 struct relocate_args args = { .l = l,
1890 .reloc_mode = ((GLRO(dl_lazy)
1891 ? RTLD_LAZY : 0)
1892 | __RTLD_NOIFUNC) };
1893 _dl_receive_error (print_unresolved, relocate_doit, &args);
1895 /* This loop depends on the dependencies of the executable to
1896 correspond in number and order to the DT_NEEDED entries. */
1897 ElfW(Dyn) *dyn = main_map->l_ld;
1898 bool first = true;
1899 while (dyn->d_tag != DT_NULL)
1901 if (dyn->d_tag == DT_NEEDED)
1903 l = l->l_next;
1904 #ifdef NEED_DL_SYSINFO_DSO
1905 /* Skip the VDSO since it's not part of the list
1906 of objects we brought in via DT_NEEDED entries. */
1907 if (l == GLRO(dl_sysinfo_map))
1908 l = l->l_next;
1909 #endif
1910 if (!l->l_used)
1912 if (first)
1914 _dl_printf ("Unused direct dependencies:\n");
1915 first = false;
1918 _dl_printf ("\t%s\n", l->l_name);
1922 ++dyn;
1925 _exit (first != true);
1927 else if (! main_map->l_info[DT_NEEDED])
1928 _dl_printf ("\tstatically linked\n");
1929 else
1931 for (l = main_map->l_next; l; l = l->l_next)
1932 if (l->l_faked)
1933 /* The library was not found. */
1934 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1935 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1936 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1937 (int) sizeof l->l_map_start * 2,
1938 (size_t) l->l_map_start);
1939 else
1940 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1941 l->l_name, (int) sizeof l->l_map_start * 2,
1942 (size_t) l->l_map_start);
1945 if (__builtin_expect (mode, trace) != trace)
1946 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1948 const ElfW(Sym) *ref = NULL;
1949 ElfW(Addr) loadbase;
1950 lookup_t result;
1952 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1953 &ref, main_map->l_scope,
1954 NULL, ELF_RTYPE_CLASS_PLT,
1955 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1957 loadbase = LOOKUP_VALUE_ADDRESS (result);
1959 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1960 INTUSE(_dl_argv)[i],
1961 (int) sizeof ref->st_value * 2,
1962 (size_t) ref->st_value,
1963 (int) sizeof loadbase * 2, (size_t) loadbase);
1965 else
1967 /* If LD_WARN is set, warn about undefined symbols. */
1968 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1970 /* We have to do symbol dependency testing. */
1971 struct relocate_args args;
1972 unsigned int i;
1974 args.reloc_mode = ((GLRO(dl_lazy) ? RTLD_LAZY : 0)
1975 | __RTLD_NOIFUNC);
1977 i = main_map->l_searchlist.r_nlist;
1978 while (i-- > 0)
1980 struct link_map *l = main_map->l_initfini[i];
1981 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1983 args.l = l;
1984 _dl_receive_error (print_unresolved, relocate_doit,
1985 &args);
1989 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1990 && rtld_multiple_ref)
1992 /* Mark the link map as not yet relocated again. */
1993 GL(dl_rtld_map).l_relocated = 0;
1994 _dl_relocate_object (&GL(dl_rtld_map),
1995 main_map->l_scope, __RTLD_NOIFUNC, 0);
1998 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
1999 if (version_info)
2001 /* Print more information. This means here, print information
2002 about the versions needed. */
2003 int first = 1;
2004 struct link_map *map;
2006 for (map = main_map; map != NULL; map = map->l_next)
2008 const char *strtab;
2009 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2010 ElfW(Verneed) *ent;
2012 if (dyn == NULL)
2013 continue;
2015 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2016 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2018 if (first)
2020 _dl_printf ("\n\tVersion information:\n");
2021 first = 0;
2024 _dl_printf ("\t%s:\n", DSO_FILENAME (map->l_name));
2026 while (1)
2028 ElfW(Vernaux) *aux;
2029 struct link_map *needed;
2031 needed = find_needed (strtab + ent->vn_file);
2032 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2034 while (1)
2036 const char *fname = NULL;
2038 if (needed != NULL
2039 && match_version (strtab + aux->vna_name,
2040 needed))
2041 fname = needed->l_name;
2043 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2044 strtab + ent->vn_file,
2045 strtab + aux->vna_name,
2046 aux->vna_flags & VER_FLG_WEAK
2047 ? "[WEAK] " : "",
2048 fname ?: "not found");
2050 if (aux->vna_next == 0)
2051 /* No more symbols. */
2052 break;
2054 /* Next symbol. */
2055 aux = (ElfW(Vernaux) *) ((char *) aux
2056 + aux->vna_next);
2059 if (ent->vn_next == 0)
2060 /* No more dependencies. */
2061 break;
2063 /* Next dependency. */
2064 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2070 _exit (0);
2073 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2074 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2075 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2077 ElfW(Lib) *liblist, *liblistend;
2078 struct link_map **r_list, **r_listend, *l;
2079 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2081 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2082 liblist = (ElfW(Lib) *)
2083 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2084 liblistend = (ElfW(Lib) *)
2085 ((char *) liblist +
2086 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2087 r_list = main_map->l_searchlist.r_list;
2088 r_listend = r_list + main_map->l_searchlist.r_nlist;
2090 for (; r_list < r_listend && liblist < liblistend; r_list++)
2092 l = *r_list;
2094 if (l == main_map)
2095 continue;
2097 /* If the library is not mapped where it should, fail. */
2098 if (l->l_addr)
2099 break;
2101 /* Next, check if checksum matches. */
2102 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2103 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2104 != liblist->l_checksum)
2105 break;
2107 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2108 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2109 != liblist->l_time_stamp)
2110 break;
2112 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2113 break;
2115 ++liblist;
2119 if (r_list == r_listend && liblist == liblistend)
2120 prelinked = true;
2122 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2123 _dl_debug_printf ("\nprelink checking: %s\n",
2124 prelinked ? "ok" : "failed");
2128 /* Now set up the variable which helps the assembler startup code. */
2129 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2131 /* Save the information about the original global scope list since
2132 we need it in the memory handling later. */
2133 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2135 /* Remember the last search directory added at startup, now that
2136 malloc will no longer be the one from dl-minimal.c. */
2137 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2139 /* Print scope information. */
2140 if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
2142 _dl_debug_printf ("\nInitial object scopes\n");
2144 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2145 _dl_show_scope (l, 0);
2148 if (prelinked)
2150 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2152 ElfW(Rela) *conflict, *conflictend;
2153 #ifndef HP_TIMING_NONAVAIL
2154 hp_timing_t start;
2155 hp_timing_t stop;
2156 #endif
2158 HP_TIMING_NOW (start);
2159 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2160 conflict = (ElfW(Rela) *)
2161 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2162 conflictend = (ElfW(Rela) *)
2163 ((char *) conflict
2164 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2165 _dl_resolve_conflicts (main_map, conflict, conflictend);
2166 HP_TIMING_NOW (stop);
2167 HP_TIMING_DIFF (relocate_time, start, stop);
2171 /* Mark all the objects so we know they have been already relocated. */
2172 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2174 l->l_relocated = 1;
2175 if (l->l_relro_size)
2176 _dl_protect_relro (l);
2178 /* Add object to slot information data if necessasy. */
2179 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2180 _dl_add_to_slotinfo (l);
2183 else
2185 /* Now we have all the objects loaded. Relocate them all except for
2186 the dynamic linker itself. We do this in reverse order so that copy
2187 relocs of earlier objects overwrite the data written by later
2188 objects. We do not re-relocate the dynamic linker itself in this
2189 loop because that could result in the GOT entries for functions we
2190 call being changed, and that would break us. It is safe to relocate
2191 the dynamic linker out of order because it has no copy relocs (we
2192 know that because it is self-contained). */
2194 int consider_profiling = GLRO(dl_profile) != NULL;
2195 #ifndef HP_TIMING_NONAVAIL
2196 hp_timing_t start;
2197 hp_timing_t stop;
2198 #endif
2200 /* If we are profiling we also must do lazy reloaction. */
2201 GLRO(dl_lazy) |= consider_profiling;
2203 HP_TIMING_NOW (start);
2204 unsigned i = main_map->l_searchlist.r_nlist;
2205 while (i-- > 0)
2207 struct link_map *l = main_map->l_initfini[i];
2209 /* While we are at it, help the memory handling a bit. We have to
2210 mark some data structures as allocated with the fake malloc()
2211 implementation in ld.so. */
2212 struct libname_list *lnp = l->l_libname->next;
2214 while (__builtin_expect (lnp != NULL, 0))
2216 lnp->dont_free = 1;
2217 lnp = lnp->next;
2219 /* Also allocated with the fake malloc(). */
2220 l->l_free_initfini = 0;
2222 if (l != &GL(dl_rtld_map))
2223 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2224 consider_profiling);
2226 /* Add object to slot information data if necessasy. */
2227 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2228 _dl_add_to_slotinfo (l);
2230 HP_TIMING_NOW (stop);
2232 HP_TIMING_DIFF (relocate_time, start, stop);
2234 /* Now enable profiling if needed. Like the previous call,
2235 this has to go here because the calls it makes should use the
2236 rtld versions of the functions (particularly calloc()), but it
2237 needs to have _dl_profile_map set up by the relocator. */
2238 if (__glibc_unlikely (GL(dl_profile_map) != NULL))
2239 /* We must prepare the profiling. */
2240 _dl_start_profile ();
2243 if ((!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2244 || count_modids != _dl_count_modids ())
2245 ++GL(dl_tls_generation);
2247 /* Now that we have completed relocation, the initializer data
2248 for the TLS blocks has its final values and we can copy them
2249 into the main thread's TLS area, which we allocated above. */
2250 _dl_allocate_tls_init (tcbp);
2252 /* And finally install it for the main thread. If ld.so itself uses
2253 TLS we know the thread pointer was initialized earlier. */
2254 if (! tls_init_tp_called)
2256 const char *lossage
2257 #ifdef USE___THREAD
2258 = TLS_INIT_TP (tcbp, USE___THREAD);
2259 #else
2260 = TLS_INIT_TP (tcbp, 0);
2261 #endif
2262 if (__glibc_unlikely (lossage != NULL))
2263 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2264 lossage);
2267 /* Make sure no new search directories have been added. */
2268 assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
2270 if (! prelinked && rtld_multiple_ref)
2272 /* There was an explicit ref to the dynamic linker as a shared lib.
2273 Re-relocate ourselves with user-controlled symbol definitions.
2275 We must do this after TLS initialization in case after this
2276 re-relocation, we might call a user-supplied function
2277 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2279 #ifndef HP_TIMING_NONAVAIL
2280 hp_timing_t start;
2281 hp_timing_t stop;
2282 hp_timing_t add;
2283 #endif
2285 HP_TIMING_NOW (start);
2286 /* Mark the link map as not yet relocated again. */
2287 GL(dl_rtld_map).l_relocated = 0;
2288 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2289 HP_TIMING_NOW (stop);
2290 HP_TIMING_DIFF (add, start, stop);
2291 HP_TIMING_ACCUM_NT (relocate_time, add);
2294 /* Do any necessary cleanups for the startup OS interface code.
2295 We do these now so that no calls are made after rtld re-relocation
2296 which might be resolved to different functions than we expect.
2297 We cannot do this before relocating the other objects because
2298 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2299 _dl_sysdep_start_cleanup ();
2301 #ifdef SHARED
2302 /* Auditing checkpoint: we have added all objects. */
2303 if (__glibc_unlikely (GLRO(dl_naudit) > 0))
2305 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2306 /* Do not call the functions for any auditing object. */
2307 if (head->l_auditing == 0)
2309 struct audit_ifaces *afct = GLRO(dl_audit);
2310 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2312 if (afct->activity != NULL)
2313 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2315 afct = afct->next;
2319 #endif
2321 /* Notify the debugger all new objects are now ready to go. We must re-get
2322 the address since by now the variable might be in another object. */
2323 r = _dl_debug_initialize (0, LM_ID_BASE);
2324 r->r_state = RT_CONSISTENT;
2325 _dl_debug_state ();
2326 LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
2328 #if defined USE_LDCONFIG && !defined MAP_COPY
2329 /* We must munmap() the cache file. */
2330 _dl_unload_cache ();
2331 #endif
2333 /* Once we return, _dl_sysdep_start will invoke
2334 the DT_INIT functions and then *USER_ENTRY. */
2337 /* This is a little helper function for resolving symbols while
2338 tracing the binary. */
2339 static void
2340 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2341 const char *errstring)
2343 if (objname[0] == '\0')
2344 objname = RTLD_PROGNAME;
2345 _dl_error_printf ("%s (%s)\n", errstring, objname);
2348 /* This is a little helper function for resolving symbols while
2349 tracing the binary. */
2350 static void
2351 print_missing_version (int errcode __attribute__ ((unused)),
2352 const char *objname, const char *errstring)
2354 _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME,
2355 objname, errstring);
2358 /* Nonzero if any of the debugging options is enabled. */
2359 static int any_debug attribute_relro;
2361 /* Process the string given as the parameter which explains which debugging
2362 options are enabled. */
2363 static void
2364 process_dl_debug (const char *dl_debug)
2366 /* When adding new entries make sure that the maximal length of a name
2367 is correctly handled in the LD_DEBUG_HELP code below. */
2368 static const struct
2370 unsigned char len;
2371 const char name[10];
2372 const char helptext[41];
2373 unsigned short int mask;
2374 } debopts[] =
2376 #define LEN_AND_STR(str) sizeof (str) - 1, str
2377 { LEN_AND_STR ("libs"), "display library search paths",
2378 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2379 { LEN_AND_STR ("reloc"), "display relocation processing",
2380 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2381 { LEN_AND_STR ("files"), "display progress for input file",
2382 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2383 { LEN_AND_STR ("symbols"), "display symbol table processing",
2384 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2385 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2386 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2387 { LEN_AND_STR ("versions"), "display version dependencies",
2388 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2389 { LEN_AND_STR ("scopes"), "display scope information",
2390 DL_DEBUG_SCOPES },
2391 { LEN_AND_STR ("all"), "all previous options combined",
2392 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2393 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS
2394 | DL_DEBUG_SCOPES },
2395 { LEN_AND_STR ("statistics"), "display relocation statistics",
2396 DL_DEBUG_STATISTICS },
2397 { LEN_AND_STR ("unused"), "determined unused DSOs",
2398 DL_DEBUG_UNUSED },
2399 { LEN_AND_STR ("help"), "display this help message and exit",
2400 DL_DEBUG_HELP },
2402 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2404 /* Skip separating white spaces and commas. */
2405 while (*dl_debug != '\0')
2407 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2409 size_t cnt;
2410 size_t len = 1;
2412 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2413 && dl_debug[len] != ',' && dl_debug[len] != ':')
2414 ++len;
2416 for (cnt = 0; cnt < ndebopts; ++cnt)
2417 if (debopts[cnt].len == len
2418 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2420 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2421 any_debug = 1;
2422 break;
2425 if (cnt == ndebopts)
2427 /* Display a warning and skip everything until next
2428 separator. */
2429 char *copy = strndupa (dl_debug, len);
2430 _dl_error_printf ("\
2431 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2434 dl_debug += len;
2435 continue;
2438 ++dl_debug;
2441 if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
2443 /* In order to get an accurate picture of whether a particular
2444 DT_NEEDED entry is actually used we have to process both
2445 the PLT and non-PLT relocation entries. */
2446 GLRO(dl_lazy) = 0;
2449 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2451 size_t cnt;
2453 _dl_printf ("\
2454 Valid options for the LD_DEBUG environment variable are:\n\n");
2456 for (cnt = 0; cnt < ndebopts; ++cnt)
2457 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2458 " " + debopts[cnt].len - 3,
2459 debopts[cnt].helptext);
2461 _dl_printf ("\n\
2462 To direct the debugging output into a file instead of standard output\n\
2463 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2464 _exit (0);
2468 static void
2469 process_dl_audit (char *str)
2471 /* The parameter is a colon separated list of DSO names. */
2472 char *p;
2474 while ((p = (strsep) (&str, ":")) != NULL)
2475 if (p[0] != '\0'
2476 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2477 || strchr (p, '/') == NULL))
2479 /* This is using the local malloc, not the system malloc. The
2480 memory can never be freed. */
2481 struct audit_list *newp = malloc (sizeof (*newp));
2482 newp->name = p;
2484 if (audit_list == NULL)
2485 audit_list = newp->next = newp;
2486 else
2488 newp->next = audit_list->next;
2489 audit_list = audit_list->next = newp;
2494 /* Process all environments variables the dynamic linker must recognize.
2495 Since all of them start with `LD_' we are a bit smarter while finding
2496 all the entries. */
2497 extern char **_environ attribute_hidden;
2500 static void
2501 process_envvars (enum mode *modep)
2503 char **runp = _environ;
2504 char *envline;
2505 enum mode mode = normal;
2506 char *debug_output = NULL;
2508 /* This is the default place for profiling data file. */
2509 GLRO(dl_profile_output)
2510 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2512 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2514 size_t len = 0;
2516 while (envline[len] != '\0' && envline[len] != '=')
2517 ++len;
2519 if (envline[len] != '=')
2520 /* This is a "LD_" variable at the end of the string without
2521 a '=' character. Ignore it since otherwise we will access
2522 invalid memory below. */
2523 continue;
2525 switch (len)
2527 case 4:
2528 /* Warning level, verbose or not. */
2529 if (memcmp (envline, "WARN", 4) == 0)
2530 GLRO(dl_verbose) = envline[5] != '\0';
2531 break;
2533 case 5:
2534 /* Debugging of the dynamic linker? */
2535 if (memcmp (envline, "DEBUG", 5) == 0)
2537 process_dl_debug (&envline[6]);
2538 break;
2540 if (memcmp (envline, "AUDIT", 5) == 0)
2541 process_dl_audit (&envline[6]);
2542 break;
2544 case 7:
2545 /* Print information about versions. */
2546 if (memcmp (envline, "VERBOSE", 7) == 0)
2548 version_info = envline[8] != '\0';
2549 break;
2552 /* List of objects to be preloaded. */
2553 if (memcmp (envline, "PRELOAD", 7) == 0)
2555 preloadlist = &envline[8];
2556 break;
2559 /* Which shared object shall be profiled. */
2560 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2561 GLRO(dl_profile) = &envline[8];
2562 break;
2564 case 8:
2565 /* Do we bind early? */
2566 if (memcmp (envline, "BIND_NOW", 8) == 0)
2568 GLRO(dl_lazy) = envline[9] == '\0';
2569 break;
2571 if (memcmp (envline, "BIND_NOT", 8) == 0)
2572 GLRO(dl_bind_not) = envline[9] != '\0';
2573 break;
2575 case 9:
2576 /* Test whether we want to see the content of the auxiliary
2577 array passed up from the kernel. */
2578 if (!INTUSE(__libc_enable_secure)
2579 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2580 _dl_show_auxv ();
2581 break;
2583 case 10:
2584 /* Mask for the important hardware capabilities. */
2585 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2586 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2587 0, 0);
2588 break;
2590 case 11:
2591 /* Path where the binary is found. */
2592 if (!INTUSE(__libc_enable_secure)
2593 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2594 GLRO(dl_origin_path) = &envline[12];
2595 break;
2597 case 12:
2598 /* The library search path. */
2599 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2601 library_path = &envline[13];
2602 break;
2605 /* Where to place the profiling data file. */
2606 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2608 debug_output = &envline[13];
2609 break;
2612 if (!INTUSE(__libc_enable_secure)
2613 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2614 GLRO(dl_dynamic_weak) = 1;
2615 break;
2617 case 13:
2618 /* We might have some extra environment variable with length 13
2619 to handle. */
2620 #ifdef EXTRA_LD_ENVVARS_13
2621 EXTRA_LD_ENVVARS_13
2622 #endif
2623 if (!INTUSE(__libc_enable_secure)
2624 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2626 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2627 break;
2630 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2631 GLRO(dl_pointer_guard) = envline[14] != '0';
2632 break;
2634 case 14:
2635 /* Where to place the profiling data file. */
2636 if (!INTUSE(__libc_enable_secure)
2637 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2638 && envline[15] != '\0')
2639 GLRO(dl_profile_output) = &envline[15];
2640 break;
2642 case 16:
2643 /* The mode of the dynamic linker can be set. */
2644 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2646 mode = trace;
2647 GLRO(dl_verbose) = 1;
2648 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2649 GLRO(dl_trace_prelink) = &envline[17];
2651 break;
2653 case 20:
2654 /* The mode of the dynamic linker can be set. */
2655 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2656 mode = trace;
2657 break;
2659 /* We might have some extra environment variable to handle. This
2660 is tricky due to the pre-processing of the length of the name
2661 in the switch statement here. The code here assumes that added
2662 environment variables have a different length. */
2663 #ifdef EXTRA_LD_ENVVARS
2664 EXTRA_LD_ENVVARS
2665 #endif
2669 /* The caller wants this information. */
2670 *modep = mode;
2672 /* Extra security for SUID binaries. Remove all dangerous environment
2673 variables. */
2674 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2676 static const char unsecure_envvars[] =
2677 #ifdef EXTRA_UNSECURE_ENVVARS
2678 EXTRA_UNSECURE_ENVVARS
2679 #endif
2680 UNSECURE_ENVVARS;
2681 const char *nextp;
2683 nextp = unsecure_envvars;
2686 unsetenv (nextp);
2687 /* We could use rawmemchr but this need not be fast. */
2688 nextp = (char *) (strchr) (nextp, '\0') + 1;
2690 while (*nextp != '\0');
2692 if (__access ("/etc/suid-debug", F_OK) != 0)
2694 unsetenv ("MALLOC_CHECK_");
2695 GLRO(dl_debug_mask) = 0;
2698 if (mode != normal)
2699 _exit (5);
2701 /* If we have to run the dynamic linker in debugging mode and the
2702 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2703 messages to this file. */
2704 else if (any_debug && debug_output != NULL)
2706 #ifdef O_NOFOLLOW
2707 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2708 #else
2709 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2710 #endif
2711 size_t name_len = strlen (debug_output);
2712 char buf[name_len + 12];
2713 char *startp;
2715 buf[name_len + 11] = '\0';
2716 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2717 *--startp = '.';
2718 startp = memcpy (startp - name_len, debug_output, name_len);
2720 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2721 if (GLRO(dl_debug_fd) == -1)
2722 /* We use standard output if opening the file failed. */
2723 GLRO(dl_debug_fd) = STDOUT_FILENO;
2728 /* Print the various times we collected. */
2729 static void
2730 __attribute ((noinline))
2731 print_statistics (hp_timing_t *rtld_total_timep)
2733 #ifndef HP_TIMING_NONAVAIL
2734 char buf[200];
2735 char *cp;
2736 char *wp;
2738 /* Total time rtld used. */
2739 if (HP_TIMING_AVAIL)
2741 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2742 _dl_debug_printf ("\nruntime linker statistics:\n"
2743 " total startup time in dynamic loader: %s\n", buf);
2745 /* Print relocation statistics. */
2746 char pbuf[30];
2747 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2748 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2749 pbuf + sizeof (pbuf), 10, 0);
2750 wp = pbuf;
2751 switch (pbuf + sizeof (pbuf) - cp)
2753 case 3:
2754 *wp++ = *cp++;
2755 case 2:
2756 *wp++ = *cp++;
2757 case 1:
2758 *wp++ = '.';
2759 *wp++ = *cp++;
2761 *wp = '\0';
2762 _dl_debug_printf ("\
2763 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2765 #endif
2767 unsigned long int num_relative_relocations = 0;
2768 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2770 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2771 continue;
2773 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2775 for (unsigned int i = 0; i < scope->r_nlist; i++)
2777 struct link_map *l = scope->r_list [i];
2779 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2780 num_relative_relocations
2781 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2782 #ifndef ELF_MACHINE_REL_RELATIVE
2783 /* Relative relocations are processed on these architectures if
2784 library is loaded to different address than p_vaddr or
2785 if not prelinked. */
2786 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2787 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2788 #else
2789 /* On e.g. IA-64 or Alpha, relative relocations are processed
2790 only if library is loaded to different address than p_vaddr. */
2791 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2792 #endif
2793 num_relative_relocations
2794 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2798 _dl_debug_printf (" number of relocations: %lu\n"
2799 " number of relocations from cache: %lu\n"
2800 " number of relative relocations: %lu\n",
2801 GL(dl_num_relocations),
2802 GL(dl_num_cache_relocations),
2803 num_relative_relocations);
2805 #ifndef HP_TIMING_NONAVAIL
2806 /* Time spend while loading the object and the dependencies. */
2807 if (HP_TIMING_AVAIL)
2809 char pbuf[30];
2810 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2811 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2812 pbuf + sizeof (pbuf), 10, 0);
2813 wp = pbuf;
2814 switch (pbuf + sizeof (pbuf) - cp)
2816 case 3:
2817 *wp++ = *cp++;
2818 case 2:
2819 *wp++ = *cp++;
2820 case 1:
2821 *wp++ = '.';
2822 *wp++ = *cp++;
2824 *wp = '\0';
2825 _dl_debug_printf ("\
2826 time needed to load objects: %s (%s%%)\n",
2827 buf, pbuf);
2829 #endif