Fix unwind info in x86 memcmp-ssse3.
[glibc.git] / elf / rtld.c
blob3afb997f85bb8a532d36c9a953755314a5bd3ed2
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2006, 2007, 2008, 2009, 2010 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
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h>
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.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>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
44 #include <assert.h>
46 /* Avoid PLT use for our local calls at startup. */
47 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
49 /* GCC has mental blocks about _exit. */
50 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
51 #define _exit exit_internal
53 /* Helper function to handle errors while resolving symbols. */
54 static void print_unresolved (int errcode, const char *objname,
55 const char *errsting);
57 /* Helper function to handle errors when a version is missing. */
58 static void print_missing_version (int errcode, const char *objname,
59 const char *errsting);
61 /* Print the various times we collected. */
62 static void print_statistics (hp_timing_t *total_timep);
64 /* Add audit objects. */
65 static void process_dl_audit (char *str);
67 /* This is a list of all the modes the dynamic loader can be in. */
68 enum mode { normal, list, verify, trace };
70 /* Process all environments variables the dynamic linker must recognize.
71 Since all of them start with `LD_' we are a bit smarter while finding
72 all the entries. */
73 static void process_envvars (enum mode *modep);
75 #ifdef DL_ARGV_NOT_RELRO
76 int _dl_argc attribute_hidden;
77 char **_dl_argv = NULL;
78 /* Nonzero if we were run directly. */
79 unsigned int _dl_skip_args attribute_hidden;
80 #else
81 int _dl_argc attribute_relro attribute_hidden;
82 char **_dl_argv attribute_relro = NULL;
83 unsigned int _dl_skip_args attribute_relro attribute_hidden;
84 #endif
85 INTDEF(_dl_argv)
87 #ifndef THREAD_SET_STACK_GUARD
88 /* Only exported for architectures that don't store the stack guard canary
89 in thread local area. */
90 uintptr_t __stack_chk_guard attribute_relro;
91 #endif
93 /* Only exported for architectures that don't store the pointer guard
94 value in thread local area. */
95 uintptr_t __pointer_chk_guard_local
96 attribute_relro attribute_hidden __attribute__ ((nocommon));
97 #ifndef THREAD_SET_POINTER_GUARD
98 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
99 #endif
102 /* List of auditing DSOs. */
103 static struct audit_list
105 const char *name;
106 struct audit_list *next;
107 } *audit_list;
109 #ifndef HAVE_INLINED_SYSCALLS
110 /* Set nonzero during loading and initialization of executable and
111 libraries, cleared before the executable's entry point runs. This
112 must not be initialized to nonzero, because the unused dynamic
113 linker loaded in for libc.so's "ld.so.1" dep will provide the
114 definition seen by libc.so's initializer; that value must be zero,
115 and will be since that dynamic linker's _dl_start and dl_main will
116 never be called. */
117 int _dl_starting_up = 0;
118 INTVARDEF(_dl_starting_up)
119 #endif
121 /* This is the structure which defines all variables global to ld.so
122 (except those which cannot be added for some reason). */
123 struct rtld_global _rtld_global =
125 /* Default presumption without further information is executable stack. */
126 ._dl_stack_flags = PF_R|PF_W|PF_X,
127 #ifdef _LIBC_REENTRANT
128 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
129 #endif
130 ._dl_nns = 1,
131 ._dl_ns =
133 [LM_ID_BASE] = { ._ns_unique_sym_table
134 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
137 /* If we would use strong_alias here the compiler would see a
138 non-hidden definition. This would undo the effect of the previous
139 declaration. So spell out was strong_alias does plus add the
140 visibility attribute. */
141 extern struct rtld_global _rtld_local
142 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
145 /* This variable is similar to _rtld_local, but all values are
146 read-only after relocation. */
147 struct rtld_global_ro _rtld_global_ro attribute_relro =
149 /* Get architecture specific initializer. */
150 #include <dl-procinfo.c>
151 #ifdef NEED_DL_SYSINFO
152 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
153 #endif
154 ._dl_debug_fd = STDERR_FILENO,
155 ._dl_use_load_bias = -2,
156 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
157 ._dl_hwcap_mask = HWCAP_IMPORTANT,
158 ._dl_lazy = 1,
159 ._dl_fpu_control = _FPU_DEFAULT,
160 ._dl_pointer_guard = 1,
162 /* Function pointers. */
163 ._dl_debug_printf = _dl_debug_printf,
164 ._dl_catch_error = _dl_catch_error,
165 ._dl_signal_error = _dl_signal_error,
166 ._dl_mcount = _dl_mcount_internal,
167 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
168 ._dl_check_caller = _dl_check_caller,
169 ._dl_open = _dl_open,
170 ._dl_close = _dl_close,
171 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
172 #ifdef HAVE_DL_DISCOVER_OSVERSION
173 ._dl_discover_osversion = _dl_discover_osversion
174 #endif
176 /* If we would use strong_alias here the compiler would see a
177 non-hidden definition. This would undo the effect of the previous
178 declaration. So spell out was strong_alias does plus add the
179 visibility attribute. */
180 extern struct rtld_global_ro _rtld_local_ro
181 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
184 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
185 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
187 /* These two variables cannot be moved into .data.rel.ro. */
188 static struct libname_list _dl_rtld_libname;
189 static struct libname_list _dl_rtld_libname2;
191 /* We expect less than a second for relocation. */
192 #ifdef HP_SMALL_TIMING_AVAIL
193 # undef HP_TIMING_AVAIL
194 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
195 #endif
197 /* Variable for statistics. */
198 #ifndef HP_TIMING_NONAVAIL
199 static hp_timing_t relocate_time;
200 static hp_timing_t load_time attribute_relro;
201 static hp_timing_t start_time attribute_relro;
202 #endif
204 /* Additional definitions needed by TLS initialization. */
205 #ifdef TLS_INIT_HELPER
206 TLS_INIT_HELPER
207 #endif
209 /* Helper function for syscall implementation. */
210 #ifdef DL_SYSINFO_IMPLEMENTATION
211 DL_SYSINFO_IMPLEMENTATION
212 #endif
214 /* Before ld.so is relocated we must not access variables which need
215 relocations. This means variables which are exported. Variables
216 declared as static are fine. If we can mark a variable hidden this
217 is fine, too. The latter is important here. We can avoid setting
218 up a temporary link map for ld.so if we can mark _rtld_global as
219 hidden. */
220 #ifdef PI_STATIC_AND_HIDDEN
221 # define DONT_USE_BOOTSTRAP_MAP 1
222 #endif
224 #ifdef DONT_USE_BOOTSTRAP_MAP
225 static ElfW(Addr) _dl_start_final (void *arg);
226 #else
227 struct dl_start_final_info
229 struct link_map l;
230 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
231 hp_timing_t start_time;
232 #endif
234 static ElfW(Addr) _dl_start_final (void *arg,
235 struct dl_start_final_info *info);
236 #endif
238 /* These defined magically in the linker script. */
239 extern char _begin[] attribute_hidden;
240 extern char _etext[] attribute_hidden;
241 extern char _end[] attribute_hidden;
244 #ifdef RTLD_START
245 RTLD_START
246 #else
247 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
248 #endif
250 #ifndef VALIDX
251 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
252 + DT_EXTRANUM + DT_VALTAGIDX (tag))
253 #endif
254 #ifndef ADDRIDX
255 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
256 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
257 #endif
259 /* This is the second half of _dl_start (below). It can be inlined safely
260 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
261 references. When the tools don't permit us to avoid using a GOT entry
262 for _dl_rtld_global (no attribute_hidden support), we must make sure
263 this function is not inlined (see below). */
265 #ifdef DONT_USE_BOOTSTRAP_MAP
266 static inline ElfW(Addr) __attribute__ ((always_inline))
267 _dl_start_final (void *arg)
268 #else
269 static ElfW(Addr) __attribute__ ((noinline))
270 _dl_start_final (void *arg, struct dl_start_final_info *info)
271 #endif
273 ElfW(Addr) start_addr;
275 if (HP_TIMING_AVAIL)
277 /* If it hasn't happen yet record the startup time. */
278 if (! HP_TIMING_INLINE)
279 HP_TIMING_NOW (start_time);
280 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
281 else
282 start_time = info->start_time;
283 #endif
285 /* Initialize the timing functions. */
286 HP_TIMING_DIFF_INIT ();
289 /* Transfer data about ourselves to the permanent link_map structure. */
290 #ifndef DONT_USE_BOOTSTRAP_MAP
291 GL(dl_rtld_map).l_addr = info->l.l_addr;
292 GL(dl_rtld_map).l_ld = info->l.l_ld;
293 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
294 sizeof GL(dl_rtld_map).l_info);
295 GL(dl_rtld_map).l_mach = info->l.l_mach;
296 GL(dl_rtld_map).l_relocated = 1;
297 #endif
298 _dl_setup_hash (&GL(dl_rtld_map));
299 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
300 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
301 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
302 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
303 /* Copy the TLS related data if necessary. */
304 #ifndef DONT_USE_BOOTSTRAP_MAP
305 # if USE___THREAD
306 assert (info->l.l_tls_modid != 0);
307 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
308 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
309 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
310 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
311 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
312 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
313 GL(dl_rtld_map).l_tls_modid = 1;
314 # else
315 # if NO_TLS_OFFSET != 0
316 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
317 # endif
318 # endif
320 #endif
322 #if HP_TIMING_AVAIL
323 HP_TIMING_NOW (GL(dl_cpuclock_offset));
324 #endif
326 /* Initialize the stack end variable. */
327 __libc_stack_end = __builtin_frame_address (0);
329 /* Call the OS-dependent function to set up life so we can do things like
330 file access. It will call `dl_main' (below) to do all the real work
331 of the dynamic linker, and then unwind our frame and run the user
332 entry point on the same stack we entered on. */
333 start_addr = _dl_sysdep_start (arg, &dl_main);
335 #ifndef HP_TIMING_NONAVAIL
336 hp_timing_t rtld_total_time;
337 if (HP_TIMING_AVAIL)
339 hp_timing_t end_time;
341 /* Get the current time. */
342 HP_TIMING_NOW (end_time);
344 /* Compute the difference. */
345 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
347 #endif
349 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
351 #ifndef HP_TIMING_NONAVAIL
352 print_statistics (&rtld_total_time);
353 #else
354 print_statistics (NULL);
355 #endif
358 return start_addr;
361 static ElfW(Addr) __attribute_used__ internal_function
362 _dl_start (void *arg)
364 #ifdef DONT_USE_BOOTSTRAP_MAP
365 # define bootstrap_map GL(dl_rtld_map)
366 #else
367 struct dl_start_final_info info;
368 # define bootstrap_map info.l
369 #endif
371 /* This #define produces dynamic linking inline functions for
372 bootstrap relocation instead of general-purpose relocation.
373 Since ld.so must not have any undefined symbols the result
374 is trivial: always the map of ld.so itself. */
375 #define RTLD_BOOTSTRAP
376 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
377 #include "dynamic-link.h"
379 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
380 #ifdef DONT_USE_BOOTSTRAP_MAP
381 HP_TIMING_NOW (start_time);
382 #else
383 HP_TIMING_NOW (info.start_time);
384 #endif
386 /* Partly clean the `bootstrap_map' structure up. Don't use
387 `memset' since it might not be built in or inlined and we cannot
388 make function calls at this point. Use '__builtin_memset' if we
389 know it is available. We do not have to clear the memory if we
390 do not have to use the temporary bootstrap_map. Global variables
391 are initialized to zero by default. */
392 #ifndef DONT_USE_BOOTSTRAP_MAP
393 # ifdef HAVE_BUILTIN_MEMSET
394 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
395 # else
396 for (size_t cnt = 0;
397 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
398 ++cnt)
399 bootstrap_map.l_info[cnt] = 0;
400 # endif
401 # if USE___THREAD
402 bootstrap_map.l_tls_modid = 0;
403 # endif
404 #endif
406 /* Figure out the run-time load address of the dynamic linker itself. */
407 bootstrap_map.l_addr = elf_machine_load_address ();
409 /* Read our own dynamic section and fill in the info array. */
410 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
411 elf_get_dynamic_info (&bootstrap_map, NULL);
413 #if NO_TLS_OFFSET != 0
414 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
415 #endif
417 /* Get the dynamic linker's own program header. First we need the ELF
418 file header. The `_begin' symbol created by the linker script points
419 to it. When we have something like GOTOFF relocs, we can use a plain
420 reference to find the runtime address. Without that, we have to rely
421 on the `l_addr' value, which is not the value we want when prelinked. */
422 #if USE___THREAD
423 dtv_t initdtv[3];
424 ElfW(Ehdr) *ehdr
425 # ifdef DONT_USE_BOOTSTRAP_MAP
426 = (ElfW(Ehdr) *) &_begin;
427 # else
428 # error This will not work with prelink.
429 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
430 # endif
431 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
432 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
433 while (cnt-- > 0)
434 if (phdr[cnt].p_type == PT_TLS)
436 void *tlsblock;
437 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
438 char *p;
440 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
441 bootstrap_map.l_tls_align = phdr[cnt].p_align;
442 if (phdr[cnt].p_align == 0)
443 bootstrap_map.l_tls_firstbyte_offset = 0;
444 else
445 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
446 & (phdr[cnt].p_align - 1));
447 assert (bootstrap_map.l_tls_blocksize != 0);
448 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
449 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
450 + phdr[cnt].p_vaddr);
452 /* We can now allocate the initial TLS block. This can happen
453 on the stack. We'll get the final memory later when we
454 know all about the various objects loaded at startup
455 time. */
456 # if TLS_TCB_AT_TP
457 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
458 TLS_INIT_TCB_ALIGN)
459 + TLS_INIT_TCB_SIZE
460 + max_align);
461 # elif TLS_DTV_AT_TP
462 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
463 bootstrap_map.l_tls_align)
464 + bootstrap_map.l_tls_blocksize
465 + max_align);
466 # else
467 /* In case a model with a different layout for the TCB and DTV
468 is defined add another #elif here and in the following #ifs. */
469 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
470 # endif
471 /* Align the TLS block. */
472 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
473 & ~(max_align - 1));
475 /* Initialize the dtv. [0] is the length, [1] the generation
476 counter. */
477 initdtv[0].counter = 1;
478 initdtv[1].counter = 0;
480 /* Initialize the TLS block. */
481 # if TLS_TCB_AT_TP
482 initdtv[2].pointer = tlsblock;
483 # elif TLS_DTV_AT_TP
484 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
485 bootstrap_map.l_tls_align);
486 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
487 # else
488 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
489 # endif
490 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
491 bootstrap_map.l_tls_initimage_size);
492 # ifdef HAVE_BUILTIN_MEMSET
493 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
494 - bootstrap_map.l_tls_initimage_size));
495 # else
497 size_t remaining = (bootstrap_map.l_tls_blocksize
498 - bootstrap_map.l_tls_initimage_size);
499 while (remaining-- > 0)
500 *p++ = '\0';
502 # endif
504 /* Install the pointer to the dtv. */
506 /* Initialize the thread pointer. */
507 # if TLS_TCB_AT_TP
508 bootstrap_map.l_tls_offset
509 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
511 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
512 initdtv);
514 const char *lossage = TLS_INIT_TP ((char *) tlsblock
515 + bootstrap_map.l_tls_offset, 0);
516 # elif TLS_DTV_AT_TP
517 INSTALL_DTV (tlsblock, initdtv);
518 const char *lossage = TLS_INIT_TP (tlsblock, 0);
519 # else
520 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
521 # endif
522 if (__builtin_expect (lossage != NULL, 0))
523 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
524 lossage);
526 /* So far this is module number one. */
527 bootstrap_map.l_tls_modid = 1;
529 /* There can only be one PT_TLS entry. */
530 break;
532 #endif /* USE___THREAD */
534 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
535 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
536 #endif
538 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
540 /* Relocate ourselves so we can do normal function calls and
541 data access using the global offset table. */
543 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
545 bootstrap_map.l_relocated = 1;
547 /* Please note that we don't allow profiling of this object and
548 therefore need not test whether we have to allocate the array
549 for the relocation results (as done in dl-reloc.c). */
551 /* Now life is sane; we can call functions and access global data.
552 Set up to use the operating system facilities, and find out from
553 the operating system's program loader where to find the program
554 header table in core. Put the rest of _dl_start into a separate
555 function, that way the compiler cannot put accesses to the GOT
556 before ELF_DYNAMIC_RELOCATE. */
558 #ifdef DONT_USE_BOOTSTRAP_MAP
559 ElfW(Addr) entry = _dl_start_final (arg);
560 #else
561 ElfW(Addr) entry = _dl_start_final (arg, &info);
562 #endif
564 #ifndef ELF_MACHINE_START_ADDRESS
565 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
566 #endif
568 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
574 /* Now life is peachy; we can do all normal operations.
575 On to the real work. */
577 /* Some helper functions. */
579 /* Arguments to relocate_doit. */
580 struct relocate_args
582 struct link_map *l;
583 int reloc_mode;
586 struct map_args
588 /* Argument to map_doit. */
589 char *str;
590 struct link_map *loader;
591 int is_preloaded;
592 int mode;
593 /* Return value of map_doit. */
594 struct link_map *map;
597 struct dlmopen_args
599 const char *fname;
600 struct link_map *map;
603 struct lookup_args
605 const char *name;
606 struct link_map *map;
607 void *result;
610 /* Arguments to version_check_doit. */
611 struct version_check_args
613 int doexit;
614 int dotrace;
617 static void
618 relocate_doit (void *a)
620 struct relocate_args *args = (struct relocate_args *) a;
622 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
625 static void
626 map_doit (void *a)
628 struct map_args *args = (struct map_args *) a;
629 args->map = _dl_map_object (args->loader, args->str,
630 args->is_preloaded, lt_library, 0, args->mode,
631 LM_ID_BASE);
634 static void
635 dlmopen_doit (void *a)
637 struct dlmopen_args *args = (struct dlmopen_args *) a;
638 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
639 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
640 __environ);
643 static void
644 lookup_doit (void *a)
646 struct lookup_args *args = (struct lookup_args *) a;
647 const ElfW(Sym) *ref = NULL;
648 args->result = NULL;
649 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
650 args->map->l_local_scope, NULL, 0,
651 DL_LOOKUP_RETURN_NEWEST, NULL);
652 if (ref != NULL)
653 args->result = DL_SYMBOL_ADDRESS (l, ref);
656 static void
657 version_check_doit (void *a)
659 struct version_check_args *args = (struct version_check_args *) a;
660 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
661 args->dotrace) && args->doexit)
662 /* We cannot start the application. Abort now. */
663 _exit (1);
667 static inline struct link_map *
668 find_needed (const char *name)
670 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
671 unsigned int n = scope->r_nlist;
673 while (n-- > 0)
674 if (_dl_name_match_p (name, scope->r_list[n]))
675 return scope->r_list[n];
677 /* Should never happen. */
678 return NULL;
681 static int
682 match_version (const char *string, struct link_map *map)
684 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
685 ElfW(Verdef) *def;
687 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
688 if (map->l_info[VERDEFTAG] == NULL)
689 /* The file has no symbol versioning. */
690 return 0;
692 def = (ElfW(Verdef) *) ((char *) map->l_addr
693 + map->l_info[VERDEFTAG]->d_un.d_ptr);
694 while (1)
696 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
698 /* Compare the version strings. */
699 if (strcmp (string, strtab + aux->vda_name) == 0)
700 /* Bingo! */
701 return 1;
703 /* If no more definitions we failed to find what we want. */
704 if (def->vd_next == 0)
705 break;
707 /* Next definition. */
708 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
711 return 0;
714 static bool tls_init_tp_called;
716 static void *
717 init_tls (void)
719 /* Number of elements in the static TLS block. */
720 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
722 /* Do not do this twice. The audit interface might have required
723 the DTV interfaces to be set up early. */
724 if (GL(dl_initial_dtv) != NULL)
725 return NULL;
727 /* Allocate the array which contains the information about the
728 dtv slots. We allocate a few entries more than needed to
729 avoid the need for reallocation. */
730 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
732 /* Allocate. */
733 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
734 calloc (sizeof (struct dtv_slotinfo_list)
735 + nelem * sizeof (struct dtv_slotinfo), 1);
736 /* No need to check the return value. If memory allocation failed
737 the program would have been terminated. */
739 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
740 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
741 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
743 /* Fill in the information from the loaded modules. No namespace
744 but the base one can be filled at this time. */
745 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
746 int i = 0;
747 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
748 l = l->l_next)
749 if (l->l_tls_blocksize != 0)
751 /* This is a module with TLS data. Store the map reference.
752 The generation counter is zero. */
753 slotinfo[i].map = l;
754 /* slotinfo[i].gen = 0; */
755 ++i;
757 assert (i == GL(dl_tls_max_dtv_idx));
759 /* Compute the TLS offsets for the various blocks. */
760 _dl_determine_tlsoffset ();
762 /* Construct the static TLS block and the dtv for the initial
763 thread. For some platforms this will include allocating memory
764 for the thread descriptor. The memory for the TLS block will
765 never be freed. It should be allocated accordingly. The dtv
766 array can be changed if dynamic loading requires it. */
767 void *tcbp = _dl_allocate_tls_storage ();
768 if (tcbp == NULL)
769 _dl_fatal_printf ("\
770 cannot allocate TLS data structures for initial thread");
772 /* Store for detection of the special case by __tls_get_addr
773 so it knows not to pass this dtv to the normal realloc. */
774 GL(dl_initial_dtv) = GET_DTV (tcbp);
776 /* And finally install it for the main thread. If ld.so itself uses
777 TLS we know the thread pointer was initialized earlier. */
778 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
779 if (__builtin_expect (lossage != NULL, 0))
780 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
781 tls_init_tp_called = true;
783 return tcbp;
786 #ifdef _LIBC_REENTRANT
787 /* _dl_error_catch_tsd points to this for the single-threaded case.
788 It's reset by the thread library for multithreaded programs. */
789 void ** __attribute__ ((const))
790 _dl_initial_error_catch_tsd (void)
792 static void *data;
793 return &data;
795 #endif
798 static unsigned int
799 do_preload (char *fname, struct link_map *main_map, const char *where)
801 const char *objname;
802 const char *err_str = NULL;
803 struct map_args args;
804 bool malloced;
806 args.str = fname;
807 args.loader = main_map;
808 args.is_preloaded = 1;
809 args.mode = 0;
811 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
813 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
814 if (__builtin_expect (err_str != NULL, 0))
816 _dl_error_printf ("\
817 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
818 fname, where);
819 /* No need to call free, this is still before
820 the libc's malloc is used. */
822 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
823 /* It is no duplicate. */
824 return 1;
826 /* Nothing loaded. */
827 return 0;
830 #if defined SHARED && defined _LIBC_REENTRANT \
831 && defined __rtld_lock_default_lock_recursive
832 static void
833 rtld_lock_default_lock_recursive (void *lock)
835 __rtld_lock_default_lock_recursive (lock);
838 static void
839 rtld_lock_default_unlock_recursive (void *lock)
841 __rtld_lock_default_unlock_recursive (lock);
843 #endif
846 static void
847 security_init (void)
849 /* Set up the stack checker's canary. */
850 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
851 #ifdef THREAD_SET_STACK_GUARD
852 THREAD_SET_STACK_GUARD (stack_chk_guard);
853 #else
854 __stack_chk_guard = stack_chk_guard;
855 #endif
857 /* Set up the pointer guard as well, if necessary. */
858 if (GLRO(dl_pointer_guard))
860 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
861 stack_chk_guard);
862 #ifdef THREAD_SET_POINTER_GUARD
863 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
864 #endif
865 __pointer_chk_guard_local = pointer_chk_guard;
868 /* We do not need the _dl_random value anymore. The less
869 information we leave behind, the better, so clear the
870 variable. */
871 _dl_random = NULL;
875 /* The library search path. */
876 static const char *library_path attribute_relro;
877 /* The list preloaded objects. */
878 static const char *preloadlist attribute_relro;
879 /* Nonzero if information about versions has to be printed. */
880 static int version_info attribute_relro;
882 static void
883 dl_main (const ElfW(Phdr) *phdr,
884 ElfW(Word) phnum,
885 ElfW(Addr) *user_entry,
886 ElfW(auxv_t) *auxv)
888 const ElfW(Phdr) *ph;
889 enum mode mode;
890 struct link_map *main_map;
891 size_t file_size;
892 char *file;
893 bool has_interp = false;
894 unsigned int i;
895 bool prelinked = false;
896 bool rtld_is_main = false;
897 #ifndef HP_TIMING_NONAVAIL
898 hp_timing_t start;
899 hp_timing_t stop;
900 hp_timing_t diff;
901 #endif
902 void *tcbp = NULL;
904 #ifdef _LIBC_REENTRANT
905 /* Explicit initialization since the reloc would just be more work. */
906 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
907 #endif
909 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
911 #if defined SHARED && defined _LIBC_REENTRANT \
912 && defined __rtld_lock_default_lock_recursive
913 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
914 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
915 #endif
917 /* The explicit initialization here is cheaper than processing the reloc
918 in the _rtld_local definition's initializer. */
919 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
921 /* Process the environment variable which control the behaviour. */
922 process_envvars (&mode);
924 #ifndef HAVE_INLINED_SYSCALLS
925 /* Set up a flag which tells we are just starting. */
926 INTUSE(_dl_starting_up) = 1;
927 #endif
929 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
931 ElfW(auxv_t) *av;
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
947 installing it. */
948 rtld_is_main = true;
950 /* Note the place where the dynamic linker actually came from. */
951 GL(dl_rtld_map).l_name = rtld_progname;
953 while (_dl_argc > 1)
954 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
956 mode = list;
957 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
959 ++_dl_skip_args;
960 --_dl_argc;
961 ++INTUSE(_dl_argv);
963 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
965 mode = verify;
967 ++_dl_skip_args;
968 --_dl_argc;
969 ++INTUSE(_dl_argv);
971 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
972 && _dl_argc > 2)
974 library_path = INTUSE(_dl_argv)[2];
976 _dl_skip_args += 2;
977 _dl_argc -= 2;
978 INTUSE(_dl_argv) += 2;
980 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
981 && _dl_argc > 2)
983 GLRO(dl_inhibit_rpath) = 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], "--audit") && _dl_argc > 2)
991 process_dl_audit (INTUSE(_dl_argv)[2]);
993 _dl_skip_args += 2;
994 _dl_argc -= 2;
995 INTUSE(_dl_argv) += 2;
997 else
998 break;
1000 /* If we have no further argument the program was called incorrectly.
1001 Grant the user some education. */
1002 if (_dl_argc < 2)
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\
1023 in LIST\n\
1024 --audit LIST use objects named in LIST as auditors\n");
1026 ++_dl_skip_args;
1027 --_dl_argc;
1028 ++INTUSE(_dl_argv);
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;
1046 break;
1049 if (__builtin_expect (mode, normal) == verify)
1051 const char *objname;
1052 const char *err_str = NULL;
1053 struct map_args args;
1054 bool malloced;
1056 args.str = rtld_progname;
1057 args.loader = NULL;
1058 args.is_preloaded = 0;
1059 args.mode = __RTLD_OPENEXEC;
1060 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1061 &args);
1062 if (__builtin_expect (err_str != NULL, 0))
1063 /* We don't free the returned string, the programs stops
1064 anyway. */
1065 _exit (EXIT_FAILURE);
1067 else
1069 HP_TIMING_NOW (start);
1070 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1071 __RTLD_OPENEXEC, LM_ID_BASE);
1072 HP_TIMING_NOW (stop);
1074 HP_TIMING_DIFF (load_time, start, stop);
1077 /* Now the map for the main executable is available. */
1078 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1080 phdr = main_map->l_phdr;
1081 phnum = main_map->l_phnum;
1082 /* We overwrite here a pointer to a malloc()ed string. But since
1083 the malloc() implementation used at this point is the dummy
1084 implementations which has no real free() function it does not
1085 makes sense to free the old string first. */
1086 main_map->l_name = (char *) "";
1087 *user_entry = main_map->l_entry;
1089 /* Adjust the on-stack auxiliary vector so that it looks like the
1090 binary was executed directly. */
1091 for (av = auxv; av->a_type != AT_NULL; av++)
1092 switch (av->a_type)
1094 case AT_PHDR:
1095 av->a_un.a_val = phdr;
1096 break;
1097 case AT_PHNUM:
1098 av->a_un.a_val = phnum;
1099 break;
1100 case AT_ENTRY:
1101 av->a_un.a_val = *user_entry;
1102 break;
1105 else
1107 /* Create a link_map for the executable itself.
1108 This will be what dlopen on "" returns. */
1109 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1110 __RTLD_OPENEXEC, LM_ID_BASE);
1111 assert (main_map != NULL);
1112 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1113 main_map->l_phdr = phdr;
1114 main_map->l_phnum = phnum;
1115 main_map->l_entry = *user_entry;
1117 /* At this point we are in a bit of trouble. We would have to
1118 fill in the values for l_dev and l_ino. But in general we
1119 do not know where the file is. We also do not handle AT_EXECFD
1120 even if it would be passed up.
1122 We leave the values here defined to 0. This is normally no
1123 problem as the program code itself is normally no shared
1124 object and therefore cannot be loaded dynamically. Nothing
1125 prevent the use of dynamic binaries and in these situations
1126 we might get problems. We might not be able to find out
1127 whether the object is already loaded. But since there is no
1128 easy way out and because the dynamic binary must also not
1129 have an SONAME we ignore this program for now. If it becomes
1130 a problem we can force people using SONAMEs. */
1132 /* We delay initializing the path structure until we got the dynamic
1133 information for the program. */
1136 main_map->l_map_end = 0;
1137 main_map->l_text_end = 0;
1138 /* Perhaps the executable has no PT_LOAD header entries at all. */
1139 main_map->l_map_start = ~0;
1140 /* And it was opened directly. */
1141 ++main_map->l_direct_opencount;
1143 /* Scan the program header table for the dynamic section. */
1144 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1145 switch (ph->p_type)
1147 case PT_PHDR:
1148 /* Find out the load address. */
1149 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1150 break;
1151 case PT_DYNAMIC:
1152 /* This tells us where to find the dynamic section,
1153 which tells us everything we need to do. */
1154 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1155 break;
1156 case PT_INTERP:
1157 /* This "interpreter segment" was used by the program loader to
1158 find the program interpreter, which is this program itself, the
1159 dynamic linker. We note what name finds us, so that a future
1160 dlopen call or DT_NEEDED entry, for something that wants to link
1161 against the dynamic linker as a shared library, will know that
1162 the shared object is already loaded. */
1163 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1164 + ph->p_vaddr);
1165 /* _dl_rtld_libname.next = NULL; Already zero. */
1166 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1168 /* Ordinarilly, we would get additional names for the loader from
1169 our DT_SONAME. This can't happen if we were actually linked as
1170 a static executable (detect this case when we have no DYNAMIC).
1171 If so, assume the filename component of the interpreter path to
1172 be our SONAME, and add it to our name list. */
1173 if (GL(dl_rtld_map).l_ld == NULL)
1175 const char *p = NULL;
1176 const char *cp = _dl_rtld_libname.name;
1178 /* Find the filename part of the path. */
1179 while (*cp != '\0')
1180 if (*cp++ == '/')
1181 p = cp;
1183 if (p != NULL)
1185 _dl_rtld_libname2.name = p;
1186 /* _dl_rtld_libname2.next = NULL; Already zero. */
1187 _dl_rtld_libname.next = &_dl_rtld_libname2;
1191 has_interp = true;
1192 break;
1193 case PT_LOAD:
1195 ElfW(Addr) mapstart;
1196 ElfW(Addr) allocend;
1198 /* Remember where the main program starts in memory. */
1199 mapstart = (main_map->l_addr
1200 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1201 if (main_map->l_map_start > mapstart)
1202 main_map->l_map_start = mapstart;
1204 /* Also where it ends. */
1205 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1206 if (main_map->l_map_end < allocend)
1207 main_map->l_map_end = allocend;
1208 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1209 main_map->l_text_end = allocend;
1211 break;
1213 case PT_TLS:
1214 if (ph->p_memsz > 0)
1216 /* Note that in the case the dynamic linker we duplicate work
1217 here since we read the PT_TLS entry already in
1218 _dl_start_final. But the result is repeatable so do not
1219 check for this special but unimportant case. */
1220 main_map->l_tls_blocksize = ph->p_memsz;
1221 main_map->l_tls_align = ph->p_align;
1222 if (ph->p_align == 0)
1223 main_map->l_tls_firstbyte_offset = 0;
1224 else
1225 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1226 & (ph->p_align - 1));
1227 main_map->l_tls_initimage_size = ph->p_filesz;
1228 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1230 /* This image gets the ID one. */
1231 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1233 break;
1235 case PT_GNU_STACK:
1236 GL(dl_stack_flags) = ph->p_flags;
1237 break;
1239 case PT_GNU_RELRO:
1240 main_map->l_relro_addr = ph->p_vaddr;
1241 main_map->l_relro_size = ph->p_memsz;
1242 break;
1245 /* Adjust the address of the TLS initialization image in case
1246 the executable is actually an ET_DYN object. */
1247 if (main_map->l_tls_initimage != NULL)
1248 main_map->l_tls_initimage
1249 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1250 if (! main_map->l_map_end)
1251 main_map->l_map_end = ~0;
1252 if (! main_map->l_text_end)
1253 main_map->l_text_end = ~0;
1254 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1256 /* We were invoked directly, so the program might not have a
1257 PT_INTERP. */
1258 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1259 /* _dl_rtld_libname.next = NULL; Already zero. */
1260 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1262 else
1263 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1265 /* If the current libname is different from the SONAME, add the
1266 latter as well. */
1267 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1268 && strcmp (GL(dl_rtld_map).l_libname->name,
1269 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1270 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1272 static struct libname_list newname;
1273 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1274 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1275 newname.next = NULL;
1276 newname.dont_free = 1;
1278 assert (GL(dl_rtld_map).l_libname->next == NULL);
1279 GL(dl_rtld_map).l_libname->next = &newname;
1281 /* The ld.so must be relocated since otherwise loading audit modules
1282 will fail since they reuse the very same ld.so. */
1283 assert (GL(dl_rtld_map).l_relocated);
1285 if (! rtld_is_main)
1287 /* Extract the contents of the dynamic section for easy access. */
1288 elf_get_dynamic_info (main_map, NULL);
1289 /* Set up our cache of pointers into the hash table. */
1290 _dl_setup_hash (main_map);
1293 if (__builtin_expect (mode, normal) == verify)
1295 /* We were called just to verify that this is a dynamic
1296 executable using us as the program interpreter. Exit with an
1297 error if we were not able to load the binary or no interpreter
1298 is specified (i.e., this is no dynamically linked binary. */
1299 if (main_map->l_ld == NULL)
1300 _exit (1);
1302 /* We allow here some platform specific code. */
1303 #ifdef DISTINGUISH_LIB_VERSIONS
1304 DISTINGUISH_LIB_VERSIONS;
1305 #endif
1306 _exit (has_interp ? 0 : 2);
1309 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1310 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1311 /* Set up the data structures for the system-supplied DSO early,
1312 so they can influence _dl_init_paths. */
1313 if (GLRO(dl_sysinfo_dso) != NULL)
1315 /* Do an abridged version of the work _dl_map_object_from_fd would do
1316 to map in the object. It's already mapped and prelinked (and
1317 better be, since it's read-only and so we couldn't relocate it).
1318 We just want our data structures to describe it as if we had just
1319 mapped and relocated it normally. */
1320 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1321 0, LM_ID_BASE);
1322 if (__builtin_expect (l != NULL, 1))
1324 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1326 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1327 + GLRO(dl_sysinfo_dso)->e_phoff);
1328 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1329 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1331 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1332 if (ph->p_type == PT_DYNAMIC)
1334 l->l_ld = (void *) ph->p_vaddr;
1335 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1337 else if (ph->p_type == PT_LOAD)
1339 if (! l->l_addr)
1340 l->l_addr = ph->p_vaddr;
1341 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1342 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1343 if ((ph->p_flags & PF_X)
1344 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1345 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1347 else
1348 /* There must be no TLS segment. */
1349 assert (ph->p_type != PT_TLS);
1351 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1352 l->l_addr = l->l_map_start - l->l_addr;
1353 l->l_map_end += l->l_addr;
1354 l->l_text_end += l->l_addr;
1355 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1356 elf_get_dynamic_info (l, dyn_temp);
1357 _dl_setup_hash (l);
1358 l->l_relocated = 1;
1360 /* Initialize l_local_scope to contain just this map. This allows
1361 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1362 So we create a single entry list pointing to l_real as its only
1363 element */
1364 l->l_local_scope[0]->r_nlist = 1;
1365 l->l_local_scope[0]->r_list = &l->l_real;
1367 /* Now that we have the info handy, use the DSO image's soname
1368 so this object can be looked up by name. Note that we do not
1369 set l_name here. That field gives the file name of the DSO,
1370 and this DSO is not associated with any file. */
1371 if (l->l_info[DT_SONAME] != NULL)
1373 /* Work around a kernel problem. The kernel cannot handle
1374 addresses in the vsyscall DSO pages in writev() calls. */
1375 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1376 + l->l_info[DT_SONAME]->d_un.d_val);
1377 size_t len = strlen (dsoname);
1378 char *copy = malloc (len);
1379 if (copy == NULL)
1380 _dl_fatal_printf ("out of memory\n");
1381 l->l_libname->name = memcpy (copy, dsoname, len);
1384 /* Rearrange the list so this DSO appears after rtld_map. */
1385 assert (l->l_next == NULL);
1386 assert (l->l_prev == main_map);
1387 GL(dl_rtld_map).l_next = l;
1388 l->l_prev = &GL(dl_rtld_map);
1389 first_preload = &l->l_next;
1391 /* We have a prelinked DSO preloaded by the system. */
1392 GLRO(dl_sysinfo_map) = l;
1393 # ifdef NEED_DL_SYSINFO
1394 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1395 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1396 # endif
1399 #endif
1401 #ifdef DL_SYSDEP_OSCHECK
1402 DL_SYSDEP_OSCHECK (dl_fatal);
1403 #endif
1405 /* Initialize the data structures for the search paths for shared
1406 objects. */
1407 _dl_init_paths (library_path);
1409 /* Initialize _r_debug. */
1410 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1411 LM_ID_BASE);
1412 r->r_state = RT_CONSISTENT;
1414 /* Put the link_map for ourselves on the chain so it can be found by
1415 name. Note that at this point the global chain of link maps contains
1416 exactly one element, which is pointed to by dl_loaded. */
1417 if (! GL(dl_rtld_map).l_name)
1418 /* If not invoked directly, the dynamic linker shared object file was
1419 found by the PT_INTERP name. */
1420 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1421 GL(dl_rtld_map).l_type = lt_library;
1422 main_map->l_next = &GL(dl_rtld_map);
1423 GL(dl_rtld_map).l_prev = main_map;
1424 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1425 ++GL(dl_load_adds);
1427 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1428 to not using bias for non-prelinked PIEs and libraries
1429 and using it for executables or prelinked PIEs or libraries. */
1430 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1431 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1433 /* Set up the program header information for the dynamic linker
1434 itself. It is needed in the dl_iterate_phdr() callbacks. */
1435 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1436 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1437 + rtld_ehdr->e_phoff);
1438 GL(dl_rtld_map).l_phdr = rtld_phdr;
1439 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1442 /* PT_GNU_RELRO is usually the last phdr. */
1443 size_t cnt = rtld_ehdr->e_phnum;
1444 while (cnt-- > 0)
1445 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1447 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1448 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1449 break;
1452 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1453 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1454 /* Assign a module ID. Do this before loading any audit modules. */
1455 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1457 /* If we have auditing DSOs to load, do it now. */
1458 if (__builtin_expect (audit_list != NULL, 0))
1460 /* Iterate over all entries in the list. The order is important. */
1461 struct audit_ifaces *last_audit = NULL;
1462 struct audit_list *al = audit_list->next;
1464 /* Since we start using the auditing DSOs right away we need to
1465 initialize the data structures now. */
1466 tcbp = init_tls ();
1468 /* Initialize security features. We need to do it this early
1469 since otherwise the constructors of the audit libraries will
1470 use different values (especially the pointer guard) and will
1471 fail later on. */
1472 security_init ();
1476 int tls_idx = GL(dl_tls_max_dtv_idx);
1478 /* Now it is time to determine the layout of the static TLS
1479 block and allocate it for the initial thread. Note that we
1480 always allocate the static block, we never defer it even if
1481 no DF_STATIC_TLS bit is set. The reason is that we know
1482 glibc will use the static model. */
1483 struct dlmopen_args dlmargs;
1484 dlmargs.fname = al->name;
1485 dlmargs.map = NULL;
1487 const char *objname;
1488 const char *err_str = NULL;
1489 bool malloced;
1490 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1491 &dlmargs);
1492 if (__builtin_expect (err_str != NULL, 0))
1494 not_loaded:
1495 _dl_error_printf ("\
1496 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1497 al->name, err_str);
1498 if (malloced)
1499 free ((char *) err_str);
1501 else
1503 struct lookup_args largs;
1504 largs.name = "la_version";
1505 largs.map = dlmargs.map;
1507 /* Check whether the interface version matches. */
1508 (void) _dl_catch_error (&objname, &err_str, &malloced,
1509 lookup_doit, &largs);
1511 unsigned int (*laversion) (unsigned int);
1512 unsigned int lav;
1513 if (err_str == NULL
1514 && (laversion = largs.result) != NULL
1515 && (lav = laversion (LAV_CURRENT)) > 0
1516 && lav <= LAV_CURRENT)
1518 /* Allocate structure for the callback function pointers.
1519 This call can never fail. */
1520 union
1522 struct audit_ifaces ifaces;
1523 #define naudit_ifaces 8
1524 void (*fptr[naudit_ifaces]) (void);
1525 } *newp = malloc (sizeof (*newp));
1527 /* Names of the auditing interfaces. All in one
1528 long string. */
1529 static const char audit_iface_names[] =
1530 "la_activity\0"
1531 "la_objsearch\0"
1532 "la_objopen\0"
1533 "la_preinit\0"
1534 #if __ELF_NATIVE_CLASS == 32
1535 "la_symbind32\0"
1536 #elif __ELF_NATIVE_CLASS == 64
1537 "la_symbind64\0"
1538 #else
1539 # error "__ELF_NATIVE_CLASS must be defined"
1540 #endif
1541 #define STRING(s) __STRING (s)
1542 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1543 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1544 "la_objclose\0";
1545 unsigned int cnt = 0;
1546 const char *cp = audit_iface_names;
1549 largs.name = cp;
1550 (void) _dl_catch_error (&objname, &err_str, &malloced,
1551 lookup_doit, &largs);
1553 /* Store the pointer. */
1554 if (err_str == NULL && largs.result != NULL)
1556 newp->fptr[cnt] = largs.result;
1558 /* The dynamic linker link map is statically
1559 allocated, initialize the data now. */
1560 GL(dl_rtld_map).l_audit[cnt].cookie
1561 = (intptr_t) &GL(dl_rtld_map);
1563 else
1564 newp->fptr[cnt] = NULL;
1565 ++cnt;
1567 cp = (char *) rawmemchr (cp, '\0') + 1;
1569 while (*cp != '\0');
1570 assert (cnt == naudit_ifaces);
1572 /* Now append the new auditing interface to the list. */
1573 newp->ifaces.next = NULL;
1574 if (last_audit == NULL)
1575 last_audit = GLRO(dl_audit) = &newp->ifaces;
1576 else
1577 last_audit = last_audit->next = &newp->ifaces;
1578 ++GLRO(dl_naudit);
1580 /* Mark the DSO as being used for auditing. */
1581 dlmargs.map->l_auditing = 1;
1583 else
1585 /* We cannot use the DSO, it does not have the
1586 appropriate interfaces or it expects something
1587 more recent. */
1588 #ifndef NDEBUG
1589 Lmid_t ns = dlmargs.map->l_ns;
1590 #endif
1591 _dl_close (dlmargs.map);
1593 /* Make sure the namespace has been cleared entirely. */
1594 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1595 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1597 GL(dl_tls_max_dtv_idx) = tls_idx;
1598 goto not_loaded;
1602 al = al->next;
1604 while (al != audit_list->next);
1606 /* If we have any auditing modules, announce that we already
1607 have two objects loaded. */
1608 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1610 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1612 for (unsigned int outer = 0; outer < 2; ++outer)
1614 struct audit_ifaces *afct = GLRO(dl_audit);
1615 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1617 if (afct->objopen != NULL)
1619 ls[outer]->l_audit[cnt].bindflags
1620 = afct->objopen (ls[outer], LM_ID_BASE,
1621 &ls[outer]->l_audit[cnt].cookie);
1623 ls[outer]->l_audit_any_plt
1624 |= ls[outer]->l_audit[cnt].bindflags != 0;
1627 afct = afct->next;
1633 /* Set up debugging before the debugger is notified for the first time. */
1634 #ifdef ELF_MACHINE_DEBUG_SETUP
1635 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1636 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1637 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1638 #else
1639 if (main_map->l_info[DT_DEBUG] != NULL)
1640 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1641 with the run-time address of the r_debug structure */
1642 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1644 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1645 case you run gdb on the dynamic linker directly. */
1646 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1647 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1648 #endif
1650 /* We start adding objects. */
1651 r->r_state = RT_ADD;
1652 _dl_debug_state ();
1654 /* Auditing checkpoint: we are ready to signal that the initial map
1655 is being constructed. */
1656 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1658 struct audit_ifaces *afct = GLRO(dl_audit);
1659 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1661 if (afct->activity != NULL)
1662 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1664 afct = afct->next;
1668 /* We have two ways to specify objects to preload: via environment
1669 variable and via the file /etc/ld.so.preload. The latter can also
1670 be used when security is enabled. */
1671 assert (*first_preload == NULL);
1672 struct link_map **preloads = NULL;
1673 unsigned int npreloads = 0;
1675 if (__builtin_expect (preloadlist != NULL, 0))
1677 /* The LD_PRELOAD environment variable gives list of libraries
1678 separated by white space or colons that are loaded before the
1679 executable's dependencies and prepended to the global scope
1680 list. If the binary is running setuid all elements
1681 containing a '/' are ignored since it is insecure. */
1682 char *list = strdupa (preloadlist);
1683 char *p;
1685 HP_TIMING_NOW (start);
1687 /* Prevent optimizing strsep. Speed is not important here. */
1688 while ((p = (strsep) (&list, " :")) != NULL)
1689 if (p[0] != '\0'
1690 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1691 || strchr (p, '/') == NULL))
1692 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1694 HP_TIMING_NOW (stop);
1695 HP_TIMING_DIFF (diff, start, stop);
1696 HP_TIMING_ACCUM_NT (load_time, diff);
1699 /* There usually is no ld.so.preload file, it should only be used
1700 for emergencies and testing. So the open call etc should usually
1701 fail. Using access() on a non-existing file is faster than using
1702 open(). So we do this first. If it succeeds we do almost twice
1703 the work but this does not matter, since it is not for production
1704 use. */
1705 static const char preload_file[] = "/etc/ld.so.preload";
1706 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1708 /* Read the contents of the file. */
1709 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1710 PROT_READ | PROT_WRITE);
1711 if (__builtin_expect (file != MAP_FAILED, 0))
1713 /* Parse the file. It contains names of libraries to be loaded,
1714 separated by white spaces or `:'. It may also contain
1715 comments introduced by `#'. */
1716 char *problem;
1717 char *runp;
1718 size_t rest;
1720 /* Eliminate comments. */
1721 runp = file;
1722 rest = file_size;
1723 while (rest > 0)
1725 char *comment = memchr (runp, '#', rest);
1726 if (comment == NULL)
1727 break;
1729 rest -= comment - runp;
1731 *comment = ' ';
1732 while (--rest > 0 && *++comment != '\n');
1735 /* We have one problematic case: if we have a name at the end of
1736 the file without a trailing terminating characters, we cannot
1737 place the \0. Handle the case separately. */
1738 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1739 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1741 problem = &file[file_size];
1742 while (problem > file && problem[-1] != ' '
1743 && problem[-1] != '\t'
1744 && problem[-1] != '\n' && problem[-1] != ':')
1745 --problem;
1747 if (problem > file)
1748 problem[-1] = '\0';
1750 else
1752 problem = NULL;
1753 file[file_size - 1] = '\0';
1756 HP_TIMING_NOW (start);
1758 if (file != problem)
1760 char *p;
1761 runp = file;
1762 while ((p = strsep (&runp, ": \t\n")) != NULL)
1763 if (p[0] != '\0')
1764 npreloads += do_preload (p, main_map, preload_file);
1767 if (problem != NULL)
1769 char *p = strndupa (problem, file_size - (problem - file));
1771 npreloads += do_preload (p, main_map, preload_file);
1774 HP_TIMING_NOW (stop);
1775 HP_TIMING_DIFF (diff, start, stop);
1776 HP_TIMING_ACCUM_NT (load_time, diff);
1778 /* We don't need the file anymore. */
1779 __munmap (file, file_size);
1783 if (__builtin_expect (*first_preload != NULL, 0))
1785 /* Set up PRELOADS with a vector of the preloaded libraries. */
1786 struct link_map *l = *first_preload;
1787 preloads = __alloca (npreloads * sizeof preloads[0]);
1788 i = 0;
1791 preloads[i++] = l;
1792 l = l->l_next;
1793 } while (l);
1794 assert (i == npreloads);
1797 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1798 specified some libraries to load, these are inserted before the actual
1799 dependencies in the executable's searchlist for symbol resolution. */
1800 HP_TIMING_NOW (start);
1801 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1802 HP_TIMING_NOW (stop);
1803 HP_TIMING_DIFF (diff, start, stop);
1804 HP_TIMING_ACCUM_NT (load_time, diff);
1806 /* Mark all objects as being in the global scope. */
1807 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1808 main_map->l_searchlist.r_list[--i]->l_global = 1;
1810 /* Remove _dl_rtld_map from the chain. */
1811 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1812 if (GL(dl_rtld_map).l_next != NULL)
1813 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1815 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1816 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1817 break;
1819 bool rtld_multiple_ref = false;
1820 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1822 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1823 put it back in the list of visible objects. We insert it into the
1824 chain in symbol search order because gdb uses the chain's order as
1825 its symbol search order. */
1826 rtld_multiple_ref = true;
1828 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1829 if (__builtin_expect (mode, normal) == normal)
1831 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1832 ? main_map->l_searchlist.r_list[i + 1]
1833 : NULL);
1834 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1835 if (GLRO(dl_sysinfo_map) != NULL
1836 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1837 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1838 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1839 #endif
1841 else
1842 /* In trace mode there might be an invisible object (which we
1843 could not find) after the previous one in the search list.
1844 In this case it doesn't matter much where we put the
1845 interpreter object, so we just initialize the list pointer so
1846 that the assertion below holds. */
1847 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1849 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1850 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1851 if (GL(dl_rtld_map).l_next != NULL)
1853 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1854 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1858 /* Now let us see whether all libraries are available in the
1859 versions we need. */
1861 struct version_check_args args;
1862 args.doexit = mode == normal;
1863 args.dotrace = mode == trace;
1864 _dl_receive_error (print_missing_version, version_check_doit, &args);
1867 /* We do not initialize any of the TLS functionality unless any of the
1868 initial modules uses TLS. This makes dynamic loading of modules with
1869 TLS impossible, but to support it requires either eagerly doing setup
1870 now or lazily doing it later. Doing it now makes us incompatible with
1871 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1872 used. Trying to do it lazily is too hairy to try when there could be
1873 multiple threads (from a non-TLS-using libpthread). */
1874 bool was_tls_init_tp_called = tls_init_tp_called;
1875 if (tcbp == NULL)
1876 tcbp = init_tls ();
1878 if (__builtin_expect (audit_list == NULL, 1))
1879 /* Initialize security features. But only if we have not done it
1880 earlier. */
1881 security_init ();
1883 if (__builtin_expect (mode, normal) != normal)
1885 /* We were run just to list the shared libraries. It is
1886 important that we do this before real relocation, because the
1887 functions we call below for output may no longer work properly
1888 after relocation. */
1889 struct link_map *l;
1891 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1893 struct r_scope_elem *scope = &main_map->l_searchlist;
1895 for (i = 0; i < scope->r_nlist; i++)
1897 l = scope->r_list [i];
1898 if (l->l_faked)
1900 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1901 continue;
1903 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1904 GLRO(dl_trace_prelink_map) = l;
1905 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1906 l->l_libname->name[0] ? l->l_libname->name
1907 : rtld_progname ?: "<main program>",
1908 l->l_name[0] ? l->l_name
1909 : rtld_progname ?: "<main program>",
1910 (int) sizeof l->l_map_start * 2,
1911 (size_t) l->l_map_start,
1912 (int) sizeof l->l_addr * 2,
1913 (size_t) l->l_addr);
1915 if (l->l_tls_modid)
1916 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1917 (int) sizeof l->l_tls_offset * 2,
1918 (size_t) l->l_tls_offset);
1919 else
1920 _dl_printf ("\n");
1923 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1925 /* Look through the dependencies of the main executable
1926 and determine which of them is not actually
1927 required. */
1928 struct link_map *l = main_map;
1930 /* Relocate the main executable. */
1931 struct relocate_args args = { .l = l,
1932 .reloc_mode = (GLRO(dl_lazy)
1933 ? RTLD_LAZY : 0) };
1934 _dl_receive_error (print_unresolved, relocate_doit, &args);
1936 /* This loop depends on the dependencies of the executable to
1937 correspond in number and order to the DT_NEEDED entries. */
1938 ElfW(Dyn) *dyn = main_map->l_ld;
1939 bool first = true;
1940 while (dyn->d_tag != DT_NULL)
1942 if (dyn->d_tag == DT_NEEDED)
1944 l = l->l_next;
1946 if (!l->l_used)
1948 if (first)
1950 _dl_printf ("Unused direct dependencies:\n");
1951 first = false;
1954 _dl_printf ("\t%s\n", l->l_name);
1958 ++dyn;
1961 _exit (first != true);
1963 else if (! main_map->l_info[DT_NEEDED])
1964 _dl_printf ("\tstatically linked\n");
1965 else
1967 for (l = main_map->l_next; l; l = l->l_next)
1968 if (l->l_faked)
1969 /* The library was not found. */
1970 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1971 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1972 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1973 (int) sizeof l->l_map_start * 2,
1974 (size_t) l->l_map_start);
1975 else
1976 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1977 l->l_name, (int) sizeof l->l_map_start * 2,
1978 (size_t) l->l_map_start);
1981 if (__builtin_expect (mode, trace) != trace)
1982 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1984 const ElfW(Sym) *ref = NULL;
1985 ElfW(Addr) loadbase;
1986 lookup_t result;
1988 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1989 &ref, main_map->l_scope,
1990 NULL, ELF_RTYPE_CLASS_PLT,
1991 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1993 loadbase = LOOKUP_VALUE_ADDRESS (result);
1995 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1996 INTUSE(_dl_argv)[i],
1997 (int) sizeof ref->st_value * 2,
1998 (size_t) ref->st_value,
1999 (int) sizeof loadbase * 2, (size_t) loadbase);
2001 else
2003 /* If LD_WARN is set, warn about undefined symbols. */
2004 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2006 /* We have to do symbol dependency testing. */
2007 struct relocate_args args;
2008 struct link_map *l;
2010 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2012 l = main_map;
2013 while (l->l_next != NULL)
2014 l = l->l_next;
2017 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2019 args.l = l;
2020 _dl_receive_error (print_unresolved, relocate_doit,
2021 &args);
2023 l = l->l_prev;
2025 while (l != NULL);
2027 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2028 && rtld_multiple_ref)
2030 /* Mark the link map as not yet relocated again. */
2031 GL(dl_rtld_map).l_relocated = 0;
2032 _dl_relocate_object (&GL(dl_rtld_map),
2033 main_map->l_scope, 0, 0);
2036 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2037 if (version_info)
2039 /* Print more information. This means here, print information
2040 about the versions needed. */
2041 int first = 1;
2042 struct link_map *map;
2044 for (map = main_map; map != NULL; map = map->l_next)
2046 const char *strtab;
2047 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2048 ElfW(Verneed) *ent;
2050 if (dyn == NULL)
2051 continue;
2053 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2054 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2056 if (first)
2058 _dl_printf ("\n\tVersion information:\n");
2059 first = 0;
2062 _dl_printf ("\t%s:\n",
2063 map->l_name[0] ? map->l_name : rtld_progname);
2065 while (1)
2067 ElfW(Vernaux) *aux;
2068 struct link_map *needed;
2070 needed = find_needed (strtab + ent->vn_file);
2071 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2073 while (1)
2075 const char *fname = NULL;
2077 if (needed != NULL
2078 && match_version (strtab + aux->vna_name,
2079 needed))
2080 fname = needed->l_name;
2082 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2083 strtab + ent->vn_file,
2084 strtab + aux->vna_name,
2085 aux->vna_flags & VER_FLG_WEAK
2086 ? "[WEAK] " : "",
2087 fname ?: "not found");
2089 if (aux->vna_next == 0)
2090 /* No more symbols. */
2091 break;
2093 /* Next symbol. */
2094 aux = (ElfW(Vernaux) *) ((char *) aux
2095 + aux->vna_next);
2098 if (ent->vn_next == 0)
2099 /* No more dependencies. */
2100 break;
2102 /* Next dependency. */
2103 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2109 _exit (0);
2112 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2113 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2114 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2116 ElfW(Lib) *liblist, *liblistend;
2117 struct link_map **r_list, **r_listend, *l;
2118 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2120 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2121 liblist = (ElfW(Lib) *)
2122 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2123 liblistend = (ElfW(Lib) *)
2124 ((char *) liblist +
2125 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2126 r_list = main_map->l_searchlist.r_list;
2127 r_listend = r_list + main_map->l_searchlist.r_nlist;
2129 for (; r_list < r_listend && liblist < liblistend; r_list++)
2131 l = *r_list;
2133 if (l == main_map)
2134 continue;
2136 /* If the library is not mapped where it should, fail. */
2137 if (l->l_addr)
2138 break;
2140 /* Next, check if checksum matches. */
2141 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2142 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2143 != liblist->l_checksum)
2144 break;
2146 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2147 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2148 != liblist->l_time_stamp)
2149 break;
2151 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2152 break;
2154 ++liblist;
2158 if (r_list == r_listend && liblist == liblistend)
2159 prelinked = true;
2161 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2162 _dl_debug_printf ("\nprelink checking: %s\n",
2163 prelinked ? "ok" : "failed");
2167 /* Now set up the variable which helps the assembler startup code. */
2168 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2170 /* Save the information about the original global scope list since
2171 we need it in the memory handling later. */
2172 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2174 if (prelinked)
2176 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2178 ElfW(Rela) *conflict, *conflictend;
2179 #ifndef HP_TIMING_NONAVAIL
2180 hp_timing_t start;
2181 hp_timing_t stop;
2182 #endif
2184 HP_TIMING_NOW (start);
2185 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2186 conflict = (ElfW(Rela) *)
2187 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2188 conflictend = (ElfW(Rela) *)
2189 ((char *) conflict
2190 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2191 _dl_resolve_conflicts (main_map, conflict, conflictend);
2192 HP_TIMING_NOW (stop);
2193 HP_TIMING_DIFF (relocate_time, start, stop);
2197 /* Mark all the objects so we know they have been already relocated. */
2198 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2200 l->l_relocated = 1;
2201 if (l->l_relro_size)
2202 _dl_protect_relro (l);
2204 /* Add object to slot information data if necessasy. */
2205 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2206 _dl_add_to_slotinfo (l);
2209 else
2211 /* Now we have all the objects loaded. Relocate them all except for
2212 the dynamic linker itself. We do this in reverse order so that copy
2213 relocs of earlier objects overwrite the data written by later
2214 objects. We do not re-relocate the dynamic linker itself in this
2215 loop because that could result in the GOT entries for functions we
2216 call being changed, and that would break us. It is safe to relocate
2217 the dynamic linker out of order because it has no copy relocs (we
2218 know that because it is self-contained). */
2220 int consider_profiling = GLRO(dl_profile) != NULL;
2221 #ifndef HP_TIMING_NONAVAIL
2222 hp_timing_t start;
2223 hp_timing_t stop;
2224 #endif
2226 /* If we are profiling we also must do lazy reloaction. */
2227 GLRO(dl_lazy) |= consider_profiling;
2229 struct link_map *l = main_map;
2230 while (l->l_next)
2231 l = l->l_next;
2233 HP_TIMING_NOW (start);
2236 /* While we are at it, help the memory handling a bit. We have to
2237 mark some data structures as allocated with the fake malloc()
2238 implementation in ld.so. */
2239 struct libname_list *lnp = l->l_libname->next;
2241 while (__builtin_expect (lnp != NULL, 0))
2243 lnp->dont_free = 1;
2244 lnp = lnp->next;
2247 if (l != &GL(dl_rtld_map))
2248 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2249 consider_profiling);
2251 /* Add object to slot information data if necessasy. */
2252 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2253 _dl_add_to_slotinfo (l);
2255 l = l->l_prev;
2257 while (l);
2258 HP_TIMING_NOW (stop);
2260 HP_TIMING_DIFF (relocate_time, start, stop);
2262 /* Now enable profiling if needed. Like the previous call,
2263 this has to go here because the calls it makes should use the
2264 rtld versions of the functions (particularly calloc()), but it
2265 needs to have _dl_profile_map set up by the relocator. */
2266 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2267 /* We must prepare the profiling. */
2268 _dl_start_profile ();
2271 #ifndef NONTLS_INIT_TP
2272 # define NONTLS_INIT_TP do { } while (0)
2273 #endif
2275 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2276 ++GL(dl_tls_generation);
2278 /* Now that we have completed relocation, the initializer data
2279 for the TLS blocks has its final values and we can copy them
2280 into the main thread's TLS area, which we allocated above. */
2281 _dl_allocate_tls_init (tcbp);
2283 /* And finally install it for the main thread. If ld.so itself uses
2284 TLS we know the thread pointer was initialized earlier. */
2285 if (! tls_init_tp_called)
2287 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2288 if (__builtin_expect (lossage != NULL, 0))
2289 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2290 lossage);
2293 if (! prelinked && rtld_multiple_ref)
2295 /* There was an explicit ref to the dynamic linker as a shared lib.
2296 Re-relocate ourselves with user-controlled symbol definitions.
2298 We must do this after TLS initialization in case after this
2299 re-relocation, we might call a user-supplied function
2300 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2302 #ifndef HP_TIMING_NONAVAIL
2303 hp_timing_t start;
2304 hp_timing_t stop;
2305 hp_timing_t add;
2306 #endif
2308 HP_TIMING_NOW (start);
2309 /* Mark the link map as not yet relocated again. */
2310 GL(dl_rtld_map).l_relocated = 0;
2311 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2312 HP_TIMING_NOW (stop);
2313 HP_TIMING_DIFF (add, start, stop);
2314 HP_TIMING_ACCUM_NT (relocate_time, add);
2317 /* Do any necessary cleanups for the startup OS interface code.
2318 We do these now so that no calls are made after rtld re-relocation
2319 which might be resolved to different functions than we expect.
2320 We cannot do this before relocating the other objects because
2321 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2322 _dl_sysdep_start_cleanup ();
2324 #ifdef SHARED
2325 /* Auditing checkpoint: we have added all objects. */
2326 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2328 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2329 /* Do not call the functions for any auditing object. */
2330 if (head->l_auditing == 0)
2332 struct audit_ifaces *afct = GLRO(dl_audit);
2333 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2335 if (afct->activity != NULL)
2336 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2338 afct = afct->next;
2342 #endif
2344 /* Notify the debugger all new objects are now ready to go. We must re-get
2345 the address since by now the variable might be in another object. */
2346 r = _dl_debug_initialize (0, LM_ID_BASE);
2347 r->r_state = RT_CONSISTENT;
2348 _dl_debug_state ();
2350 #ifndef MAP_COPY
2351 /* We must munmap() the cache file. */
2352 _dl_unload_cache ();
2353 #endif
2355 /* Once we return, _dl_sysdep_start will invoke
2356 the DT_INIT functions and then *USER_ENTRY. */
2359 /* This is a little helper function for resolving symbols while
2360 tracing the binary. */
2361 static void
2362 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2363 const char *errstring)
2365 if (objname[0] == '\0')
2366 objname = rtld_progname ?: "<main program>";
2367 _dl_error_printf ("%s (%s)\n", errstring, objname);
2370 /* This is a little helper function for resolving symbols while
2371 tracing the binary. */
2372 static void
2373 print_missing_version (int errcode __attribute__ ((unused)),
2374 const char *objname, const char *errstring)
2376 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2377 objname, errstring);
2380 /* Nonzero if any of the debugging options is enabled. */
2381 static int any_debug attribute_relro;
2383 /* Process the string given as the parameter which explains which debugging
2384 options are enabled. */
2385 static void
2386 process_dl_debug (const char *dl_debug)
2388 /* When adding new entries make sure that the maximal length of a name
2389 is correctly handled in the LD_DEBUG_HELP code below. */
2390 static const struct
2392 unsigned char len;
2393 const char name[10];
2394 const char helptext[41];
2395 unsigned short int mask;
2396 } debopts[] =
2398 #define LEN_AND_STR(str) sizeof (str) - 1, str
2399 { LEN_AND_STR ("libs"), "display library search paths",
2400 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2401 { LEN_AND_STR ("reloc"), "display relocation processing",
2402 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2403 { LEN_AND_STR ("files"), "display progress for input file",
2404 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2405 { LEN_AND_STR ("symbols"), "display symbol table processing",
2406 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2407 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2408 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2409 { LEN_AND_STR ("versions"), "display version dependencies",
2410 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2411 { LEN_AND_STR ("all"), "all previous options combined",
2412 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2413 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2414 { LEN_AND_STR ("statistics"), "display relocation statistics",
2415 DL_DEBUG_STATISTICS },
2416 { LEN_AND_STR ("unused"), "determined unused DSOs",
2417 DL_DEBUG_UNUSED },
2418 { LEN_AND_STR ("help"), "display this help message and exit",
2419 DL_DEBUG_HELP },
2421 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2423 /* Skip separating white spaces and commas. */
2424 while (*dl_debug != '\0')
2426 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2428 size_t cnt;
2429 size_t len = 1;
2431 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2432 && dl_debug[len] != ',' && dl_debug[len] != ':')
2433 ++len;
2435 for (cnt = 0; cnt < ndebopts; ++cnt)
2436 if (debopts[cnt].len == len
2437 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2439 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2440 any_debug = 1;
2441 break;
2444 if (cnt == ndebopts)
2446 /* Display a warning and skip everything until next
2447 separator. */
2448 char *copy = strndupa (dl_debug, len);
2449 _dl_error_printf ("\
2450 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2453 dl_debug += len;
2454 continue;
2457 ++dl_debug;
2460 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2462 size_t cnt;
2464 _dl_printf ("\
2465 Valid options for the LD_DEBUG environment variable are:\n\n");
2467 for (cnt = 0; cnt < ndebopts; ++cnt)
2468 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2469 " " + debopts[cnt].len - 3,
2470 debopts[cnt].helptext);
2472 _dl_printf ("\n\
2473 To direct the debugging output into a file instead of standard output\n\
2474 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2475 _exit (0);
2479 static void
2480 process_dl_audit (char *str)
2482 /* The parameter is a colon separated list of DSO names. */
2483 char *p;
2485 while ((p = (strsep) (&str, ":")) != NULL)
2486 if (p[0] != '\0'
2487 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2488 || strchr (p, '/') == NULL))
2490 /* This is using the local malloc, not the system malloc. The
2491 memory can never be freed. */
2492 struct audit_list *newp = malloc (sizeof (*newp));
2493 newp->name = p;
2495 if (audit_list == NULL)
2496 audit_list = newp->next = newp;
2497 else
2499 newp->next = audit_list->next;
2500 audit_list = audit_list->next = newp;
2505 /* Process all environments variables the dynamic linker must recognize.
2506 Since all of them start with `LD_' we are a bit smarter while finding
2507 all the entries. */
2508 extern char **_environ attribute_hidden;
2511 static void
2512 process_envvars (enum mode *modep)
2514 char **runp = _environ;
2515 char *envline;
2516 enum mode mode = normal;
2517 char *debug_output = NULL;
2519 /* This is the default place for profiling data file. */
2520 GLRO(dl_profile_output)
2521 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2523 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2525 size_t len = 0;
2527 while (envline[len] != '\0' && envline[len] != '=')
2528 ++len;
2530 if (envline[len] != '=')
2531 /* This is a "LD_" variable at the end of the string without
2532 a '=' character. Ignore it since otherwise we will access
2533 invalid memory below. */
2534 continue;
2536 switch (len)
2538 case 4:
2539 /* Warning level, verbose or not. */
2540 if (memcmp (envline, "WARN", 4) == 0)
2541 GLRO(dl_verbose) = envline[5] != '\0';
2542 break;
2544 case 5:
2545 /* Debugging of the dynamic linker? */
2546 if (memcmp (envline, "DEBUG", 5) == 0)
2548 process_dl_debug (&envline[6]);
2549 break;
2551 if (memcmp (envline, "AUDIT", 5) == 0)
2552 process_dl_audit (&envline[6]);
2553 break;
2555 case 7:
2556 /* Print information about versions. */
2557 if (memcmp (envline, "VERBOSE", 7) == 0)
2559 version_info = envline[8] != '\0';
2560 break;
2563 /* List of objects to be preloaded. */
2564 if (memcmp (envline, "PRELOAD", 7) == 0)
2566 preloadlist = &envline[8];
2567 break;
2570 /* Which shared object shall be profiled. */
2571 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2572 GLRO(dl_profile) = &envline[8];
2573 break;
2575 case 8:
2576 /* Do we bind early? */
2577 if (memcmp (envline, "BIND_NOW", 8) == 0)
2579 GLRO(dl_lazy) = envline[9] == '\0';
2580 break;
2582 if (memcmp (envline, "BIND_NOT", 8) == 0)
2583 GLRO(dl_bind_not) = envline[9] != '\0';
2584 break;
2586 case 9:
2587 /* Test whether we want to see the content of the auxiliary
2588 array passed up from the kernel. */
2589 if (!INTUSE(__libc_enable_secure)
2590 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2591 _dl_show_auxv ();
2592 break;
2594 case 10:
2595 /* Mask for the important hardware capabilities. */
2596 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2597 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2598 0, 0);
2599 break;
2601 case 11:
2602 /* Path where the binary is found. */
2603 if (!INTUSE(__libc_enable_secure)
2604 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2605 GLRO(dl_origin_path) = &envline[12];
2606 break;
2608 case 12:
2609 /* The library search path. */
2610 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2612 library_path = &envline[13];
2613 break;
2616 /* Where to place the profiling data file. */
2617 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2619 debug_output = &envline[13];
2620 break;
2623 if (!INTUSE(__libc_enable_secure)
2624 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2625 GLRO(dl_dynamic_weak) = 1;
2626 break;
2628 case 13:
2629 /* We might have some extra environment variable with length 13
2630 to handle. */
2631 #ifdef EXTRA_LD_ENVVARS_13
2632 EXTRA_LD_ENVVARS_13
2633 #endif
2634 if (!INTUSE(__libc_enable_secure)
2635 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2637 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2638 break;
2641 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2642 GLRO(dl_pointer_guard) = envline[14] != '0';
2643 break;
2645 case 14:
2646 /* Where to place the profiling data file. */
2647 if (!INTUSE(__libc_enable_secure)
2648 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2649 && envline[15] != '\0')
2650 GLRO(dl_profile_output) = &envline[15];
2651 break;
2653 case 16:
2654 /* The mode of the dynamic linker can be set. */
2655 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2657 mode = trace;
2658 GLRO(dl_verbose) = 1;
2659 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2660 GLRO(dl_trace_prelink) = &envline[17];
2662 break;
2664 case 20:
2665 /* The mode of the dynamic linker can be set. */
2666 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2667 mode = trace;
2668 break;
2670 /* We might have some extra environment variable to handle. This
2671 is tricky due to the pre-processing of the length of the name
2672 in the switch statement here. The code here assumes that added
2673 environment variables have a different length. */
2674 #ifdef EXTRA_LD_ENVVARS
2675 EXTRA_LD_ENVVARS
2676 #endif
2680 /* The caller wants this information. */
2681 *modep = mode;
2683 /* Extra security for SUID binaries. Remove all dangerous environment
2684 variables. */
2685 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2687 static const char unsecure_envvars[] =
2688 #ifdef EXTRA_UNSECURE_ENVVARS
2689 EXTRA_UNSECURE_ENVVARS
2690 #endif
2691 UNSECURE_ENVVARS;
2692 const char *nextp;
2694 nextp = unsecure_envvars;
2697 unsetenv (nextp);
2698 /* We could use rawmemchr but this need not be fast. */
2699 nextp = (char *) (strchr) (nextp, '\0') + 1;
2701 while (*nextp != '\0');
2703 if (__access ("/etc/suid-debug", F_OK) != 0)
2705 unsetenv ("MALLOC_CHECK_");
2706 GLRO(dl_debug_mask) = 0;
2709 if (mode != normal)
2710 _exit (5);
2712 /* If we have to run the dynamic linker in debugging mode and the
2713 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2714 messages to this file. */
2715 else if (any_debug && debug_output != NULL)
2717 #ifdef O_NOFOLLOW
2718 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2719 #else
2720 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2721 #endif
2722 size_t name_len = strlen (debug_output);
2723 char buf[name_len + 12];
2724 char *startp;
2726 buf[name_len + 11] = '\0';
2727 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2728 *--startp = '.';
2729 startp = memcpy (startp - name_len, debug_output, name_len);
2731 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2732 if (GLRO(dl_debug_fd) == -1)
2733 /* We use standard output if opening the file failed. */
2734 GLRO(dl_debug_fd) = STDOUT_FILENO;
2739 /* Print the various times we collected. */
2740 static void
2741 __attribute ((noinline))
2742 print_statistics (hp_timing_t *rtld_total_timep)
2744 #ifndef HP_TIMING_NONAVAIL
2745 char buf[200];
2746 char *cp;
2747 char *wp;
2749 /* Total time rtld used. */
2750 if (HP_TIMING_AVAIL)
2752 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2753 _dl_debug_printf ("\nruntime linker statistics:\n"
2754 " total startup time in dynamic loader: %s\n", buf);
2756 /* Print relocation statistics. */
2757 char pbuf[30];
2758 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2759 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2760 pbuf + sizeof (pbuf), 10, 0);
2761 wp = pbuf;
2762 switch (pbuf + sizeof (pbuf) - cp)
2764 case 3:
2765 *wp++ = *cp++;
2766 case 2:
2767 *wp++ = *cp++;
2768 case 1:
2769 *wp++ = '.';
2770 *wp++ = *cp++;
2772 *wp = '\0';
2773 _dl_debug_printf ("\
2774 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2776 #endif
2778 unsigned long int num_relative_relocations = 0;
2779 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2781 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2782 continue;
2784 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2786 for (unsigned int i = 0; i < scope->r_nlist; i++)
2788 struct link_map *l = scope->r_list [i];
2790 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2791 num_relative_relocations
2792 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2793 #ifndef ELF_MACHINE_REL_RELATIVE
2794 /* Relative relocations are processed on these architectures if
2795 library is loaded to different address than p_vaddr or
2796 if not prelinked. */
2797 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2798 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2799 #else
2800 /* On e.g. IA-64 or Alpha, relative relocations are processed
2801 only if library is loaded to different address than p_vaddr. */
2802 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2803 #endif
2804 num_relative_relocations
2805 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2809 _dl_debug_printf (" number of relocations: %lu\n"
2810 " number of relocations from cache: %lu\n"
2811 " number of relative relocations: %lu\n",
2812 GL(dl_num_relocations),
2813 GL(dl_num_cache_relocations),
2814 num_relative_relocations);
2816 #ifndef HP_TIMING_NONAVAIL
2817 /* Time spend while loading the object and the dependencies. */
2818 if (HP_TIMING_AVAIL)
2820 char pbuf[30];
2821 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2822 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2823 pbuf + sizeof (pbuf), 10, 0);
2824 wp = pbuf;
2825 switch (pbuf + sizeof (pbuf) - cp)
2827 case 3:
2828 *wp++ = *cp++;
2829 case 2:
2830 *wp++ = *cp++;
2831 case 1:
2832 *wp++ = '.';
2833 *wp++ = *cp++;
2835 *wp = '\0';
2836 _dl_debug_printf ("\
2837 time needed to load objects: %s (%s%%)\n",
2838 buf, pbuf);
2840 #endif