Updated to fedora-glibc-20071212T1051
[glibc.git] / elf / rtld.c
blob98817d9fa05538d6810b687cbb01ba5a549e34ca
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2006, 2007 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> /* Check if MAP_ANON is defined. */
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
131 /* If we would use strong_alias here the compiler would see a
132 non-hidden definition. This would undo the effect of the previous
133 declaration. So spell out was strong_alias does plus add the
134 visibility attribute. */
135 extern struct rtld_global _rtld_local
136 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
139 /* This variable is similar to _rtld_local, but all values are
140 read-only after relocation. */
141 struct rtld_global_ro _rtld_global_ro attribute_relro =
143 /* Get architecture specific initializer. */
144 #include <dl-procinfo.c>
145 #ifdef NEED_DL_SYSINFO
146 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
147 #endif
148 ._dl_debug_fd = STDERR_FILENO,
149 ._dl_use_load_bias = -2,
150 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
151 ._dl_hwcap_mask = HWCAP_IMPORTANT,
152 ._dl_lazy = 1,
153 ._dl_fpu_control = _FPU_DEFAULT,
154 ._dl_pointer_guard = 1,
156 /* Function pointers. */
157 ._dl_debug_printf = _dl_debug_printf,
158 ._dl_catch_error = _dl_catch_error,
159 ._dl_signal_error = _dl_signal_error,
160 ._dl_mcount = _dl_mcount_internal,
161 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
162 ._dl_check_caller = _dl_check_caller,
163 ._dl_open = _dl_open,
164 ._dl_close = _dl_close
166 /* If we would use strong_alias here the compiler would see a
167 non-hidden definition. This would undo the effect of the previous
168 declaration. So spell out was strong_alias does plus add the
169 visibility attribute. */
170 extern struct rtld_global_ro _rtld_local_ro
171 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
174 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
175 ElfW(Addr) *user_entry);
177 /* These two variables cannot be moved into .data.rel.ro. */
178 static struct libname_list _dl_rtld_libname;
179 static struct libname_list _dl_rtld_libname2;
181 /* We expect less than a second for relocation. */
182 #ifdef HP_SMALL_TIMING_AVAIL
183 # undef HP_TIMING_AVAIL
184 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
185 #endif
187 /* Variable for statistics. */
188 #ifndef HP_TIMING_NONAVAIL
189 static hp_timing_t relocate_time;
190 static hp_timing_t load_time attribute_relro;
191 static hp_timing_t start_time attribute_relro;
192 #endif
194 /* Additional definitions needed by TLS initialization. */
195 #ifdef TLS_INIT_HELPER
196 TLS_INIT_HELPER
197 #endif
199 /* Helper function for syscall implementation. */
200 #ifdef DL_SYSINFO_IMPLEMENTATION
201 DL_SYSINFO_IMPLEMENTATION
202 #endif
204 /* Before ld.so is relocated we must not access variables which need
205 relocations. This means variables which are exported. Variables
206 declared as static are fine. If we can mark a variable hidden this
207 is fine, too. The latter is important here. We can avoid setting
208 up a temporary link map for ld.so if we can mark _rtld_global as
209 hidden. */
210 #ifdef PI_STATIC_AND_HIDDEN
211 # define DONT_USE_BOOTSTRAP_MAP 1
212 #endif
214 #ifdef DONT_USE_BOOTSTRAP_MAP
215 static ElfW(Addr) _dl_start_final (void *arg);
216 #else
217 struct dl_start_final_info
219 struct link_map l;
220 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
221 hp_timing_t start_time;
222 #endif
224 static ElfW(Addr) _dl_start_final (void *arg,
225 struct dl_start_final_info *info);
226 #endif
228 /* These defined magically in the linker script. */
229 extern char _begin[] attribute_hidden;
230 extern char _etext[] attribute_hidden;
231 extern char _end[] attribute_hidden;
234 #ifdef RTLD_START
235 RTLD_START
236 #else
237 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
238 #endif
240 #ifndef VALIDX
241 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
242 + DT_EXTRANUM + DT_VALTAGIDX (tag))
243 #endif
244 #ifndef ADDRIDX
245 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
246 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
247 #endif
249 /* This is the second half of _dl_start (below). It can be inlined safely
250 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
251 references. When the tools don't permit us to avoid using a GOT entry
252 for _dl_rtld_global (no attribute_hidden support), we must make sure
253 this function is not inlined (see below). */
255 #ifdef DONT_USE_BOOTSTRAP_MAP
256 static inline ElfW(Addr) __attribute__ ((always_inline))
257 _dl_start_final (void *arg)
258 #else
259 static ElfW(Addr) __attribute__ ((noinline))
260 _dl_start_final (void *arg, struct dl_start_final_info *info)
261 #endif
263 ElfW(Addr) start_addr;
265 if (HP_TIMING_AVAIL)
267 /* If it hasn't happen yet record the startup time. */
268 if (! HP_TIMING_INLINE)
269 HP_TIMING_NOW (start_time);
270 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
271 else
272 start_time = info->start_time;
273 #endif
275 /* Initialize the timing functions. */
276 HP_TIMING_DIFF_INIT ();
279 /* Transfer data about ourselves to the permanent link_map structure. */
280 #ifndef DONT_USE_BOOTSTRAP_MAP
281 GL(dl_rtld_map).l_addr = info->l.l_addr;
282 GL(dl_rtld_map).l_ld = info->l.l_ld;
283 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
284 sizeof GL(dl_rtld_map).l_info);
285 GL(dl_rtld_map).l_mach = info->l.l_mach;
286 GL(dl_rtld_map).l_relocated = 1;
287 #endif
288 _dl_setup_hash (&GL(dl_rtld_map));
289 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
290 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
291 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
292 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
293 /* Copy the TLS related data if necessary. */
294 #ifndef DONT_USE_BOOTSTRAP_MAP
295 # if USE___THREAD
296 assert (info->l.l_tls_modid != 0);
297 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
298 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
299 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
300 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
301 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
302 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
303 GL(dl_rtld_map).l_tls_modid = 1;
304 # else
305 # if NO_TLS_OFFSET != 0
306 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
307 # endif
308 # endif
310 #endif
312 #if HP_TIMING_AVAIL
313 HP_TIMING_NOW (GL(dl_cpuclock_offset));
314 #endif
316 /* Initialize the stack end variable. */
317 __libc_stack_end = __builtin_frame_address (0);
319 /* Call the OS-dependent function to set up life so we can do things like
320 file access. It will call `dl_main' (below) to do all the real work
321 of the dynamic linker, and then unwind our frame and run the user
322 entry point on the same stack we entered on. */
323 start_addr = _dl_sysdep_start (arg, &dl_main);
325 #ifndef HP_TIMING_NONAVAIL
326 hp_timing_t rtld_total_time;
327 if (HP_TIMING_AVAIL)
329 hp_timing_t end_time;
331 /* Get the current time. */
332 HP_TIMING_NOW (end_time);
334 /* Compute the difference. */
335 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
337 #endif
339 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
341 #ifndef HP_TIMING_NONAVAIL
342 print_statistics (&rtld_total_time);
343 #else
344 print_statistics (NULL);
345 #endif
348 return start_addr;
351 static ElfW(Addr) __attribute_used__ internal_function
352 _dl_start (void *arg)
354 #ifdef DONT_USE_BOOTSTRAP_MAP
355 # define bootstrap_map GL(dl_rtld_map)
356 #else
357 struct dl_start_final_info info;
358 # define bootstrap_map info.l
359 #endif
361 /* This #define produces dynamic linking inline functions for
362 bootstrap relocation instead of general-purpose relocation.
363 Since ld.so must not have any undefined symbols the result
364 is trivial: always the map of ld.so itself. */
365 #define RTLD_BOOTSTRAP
366 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
367 #include "dynamic-link.h"
369 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
370 #ifdef DONT_USE_BOOTSTRAP_MAP
371 HP_TIMING_NOW (start_time);
372 #else
373 HP_TIMING_NOW (info.start_time);
374 #endif
376 /* Partly clean the `bootstrap_map' structure up. Don't use
377 `memset' since it might not be built in or inlined and we cannot
378 make function calls at this point. Use '__builtin_memset' if we
379 know it is available. We do not have to clear the memory if we
380 do not have to use the temporary bootstrap_map. Global variables
381 are initialized to zero by default. */
382 #ifndef DONT_USE_BOOTSTRAP_MAP
383 # ifdef HAVE_BUILTIN_MEMSET
384 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
385 # else
386 for (size_t cnt = 0;
387 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
388 ++cnt)
389 bootstrap_map.l_info[cnt] = 0;
390 # endif
391 # if USE___THREAD
392 bootstrap_map.l_tls_modid = 0;
393 # endif
394 #endif
396 /* Figure out the run-time load address of the dynamic linker itself. */
397 bootstrap_map.l_addr = elf_machine_load_address ();
399 /* Read our own dynamic section and fill in the info array. */
400 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
401 elf_get_dynamic_info (&bootstrap_map, NULL);
403 #if NO_TLS_OFFSET != 0
404 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
405 #endif
407 /* Get the dynamic linker's own program header. First we need the ELF
408 file header. The `_begin' symbol created by the linker script points
409 to it. When we have something like GOTOFF relocs, we can use a plain
410 reference to find the runtime address. Without that, we have to rely
411 on the `l_addr' value, which is not the value we want when prelinked. */
412 #if USE___THREAD
413 dtv_t initdtv[3];
414 ElfW(Ehdr) *ehdr
415 # ifdef DONT_USE_BOOTSTRAP_MAP
416 = (ElfW(Ehdr) *) &_begin;
417 # else
418 # error This will not work with prelink.
419 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
420 # endif
421 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
422 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
423 while (cnt-- > 0)
424 if (phdr[cnt].p_type == PT_TLS)
426 void *tlsblock;
427 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
428 char *p;
430 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
431 bootstrap_map.l_tls_align = phdr[cnt].p_align;
432 if (phdr[cnt].p_align == 0)
433 bootstrap_map.l_tls_firstbyte_offset = 0;
434 else
435 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
436 & (phdr[cnt].p_align - 1));
437 assert (bootstrap_map.l_tls_blocksize != 0);
438 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
439 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
440 + phdr[cnt].p_vaddr);
442 /* We can now allocate the initial TLS block. This can happen
443 on the stack. We'll get the final memory later when we
444 know all about the various objects loaded at startup
445 time. */
446 # if TLS_TCB_AT_TP
447 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
448 TLS_INIT_TCB_ALIGN)
449 + TLS_INIT_TCB_SIZE
450 + max_align);
451 # elif TLS_DTV_AT_TP
452 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
453 bootstrap_map.l_tls_align)
454 + bootstrap_map.l_tls_blocksize
455 + max_align);
456 # else
457 /* In case a model with a different layout for the TCB and DTV
458 is defined add another #elif here and in the following #ifs. */
459 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
460 # endif
461 /* Align the TLS block. */
462 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
463 & ~(max_align - 1));
465 /* Initialize the dtv. [0] is the length, [1] the generation
466 counter. */
467 initdtv[0].counter = 1;
468 initdtv[1].counter = 0;
470 /* Initialize the TLS block. */
471 # if TLS_TCB_AT_TP
472 initdtv[2].pointer = tlsblock;
473 # elif TLS_DTV_AT_TP
474 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
475 bootstrap_map.l_tls_align);
476 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
477 # else
478 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
479 # endif
480 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
481 bootstrap_map.l_tls_initimage_size);
482 # ifdef HAVE_BUILTIN_MEMSET
483 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
484 - bootstrap_map.l_tls_initimage_size));
485 # else
487 size_t remaining = (bootstrap_map.l_tls_blocksize
488 - bootstrap_map.l_tls_initimage_size);
489 while (remaining-- > 0)
490 *p++ = '\0';
492 # endif
494 /* Install the pointer to the dtv. */
496 /* Initialize the thread pointer. */
497 # if TLS_TCB_AT_TP
498 bootstrap_map.l_tls_offset
499 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
501 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
502 initdtv);
504 const char *lossage = TLS_INIT_TP ((char *) tlsblock
505 + bootstrap_map.l_tls_offset, 0);
506 # elif TLS_DTV_AT_TP
507 INSTALL_DTV (tlsblock, initdtv);
508 const char *lossage = TLS_INIT_TP (tlsblock, 0);
509 # else
510 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
511 # endif
512 if (__builtin_expect (lossage != NULL, 0))
513 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
514 lossage);
516 /* So far this is module number one. */
517 bootstrap_map.l_tls_modid = 1;
519 /* There can only be one PT_TLS entry. */
520 break;
522 #endif /* USE___THREAD */
524 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
525 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
526 #endif
528 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
530 /* Relocate ourselves so we can do normal function calls and
531 data access using the global offset table. */
533 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
535 bootstrap_map.l_relocated = 1;
537 /* Please note that we don't allow profiling of this object and
538 therefore need not test whether we have to allocate the array
539 for the relocation results (as done in dl-reloc.c). */
541 /* Now life is sane; we can call functions and access global data.
542 Set up to use the operating system facilities, and find out from
543 the operating system's program loader where to find the program
544 header table in core. Put the rest of _dl_start into a separate
545 function, that way the compiler cannot put accesses to the GOT
546 before ELF_DYNAMIC_RELOCATE. */
548 #ifdef DONT_USE_BOOTSTRAP_MAP
549 ElfW(Addr) entry = _dl_start_final (arg);
550 #else
551 ElfW(Addr) entry = _dl_start_final (arg, &info);
552 #endif
554 #ifndef ELF_MACHINE_START_ADDRESS
555 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
556 #endif
558 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
564 /* Now life is peachy; we can do all normal operations.
565 On to the real work. */
567 /* Some helper functions. */
569 /* Arguments to relocate_doit. */
570 struct relocate_args
572 struct link_map *l;
573 int lazy;
576 struct map_args
578 /* Argument to map_doit. */
579 char *str;
580 struct link_map *loader;
581 int is_preloaded;
582 int mode;
583 /* Return value of map_doit. */
584 struct link_map *map;
587 struct dlmopen_args
589 const char *fname;
590 struct link_map *map;
593 struct lookup_args
595 const char *name;
596 struct link_map *map;
597 void *result;
600 /* Arguments to version_check_doit. */
601 struct version_check_args
603 int doexit;
604 int dotrace;
607 static void
608 relocate_doit (void *a)
610 struct relocate_args *args = (struct relocate_args *) a;
612 _dl_relocate_object (args->l, args->l->l_scope, args->lazy, 0);
615 static void
616 map_doit (void *a)
618 struct map_args *args = (struct map_args *) a;
619 args->map = _dl_map_object (args->loader, args->str,
620 args->is_preloaded, lt_library, 0, args->mode,
621 LM_ID_BASE);
624 static void
625 dlmopen_doit (void *a)
627 struct dlmopen_args *args = (struct dlmopen_args *) a;
628 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
629 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
630 __environ);
633 static void
634 lookup_doit (void *a)
636 struct lookup_args *args = (struct lookup_args *) a;
637 const ElfW(Sym) *ref = NULL;
638 args->result = NULL;
639 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
640 args->map->l_local_scope, NULL, 0,
641 DL_LOOKUP_RETURN_NEWEST, NULL);
642 if (ref != NULL)
643 args->result = DL_SYMBOL_ADDRESS (l, ref);
646 static void
647 version_check_doit (void *a)
649 struct version_check_args *args = (struct version_check_args *) a;
650 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
651 args->dotrace) && args->doexit)
652 /* We cannot start the application. Abort now. */
653 _exit (1);
657 static inline struct link_map *
658 find_needed (const char *name)
660 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
661 unsigned int n = scope->r_nlist;
663 while (n-- > 0)
664 if (_dl_name_match_p (name, scope->r_list[n]))
665 return scope->r_list[n];
667 /* Should never happen. */
668 return NULL;
671 static int
672 match_version (const char *string, struct link_map *map)
674 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
675 ElfW(Verdef) *def;
677 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
678 if (map->l_info[VERDEFTAG] == NULL)
679 /* The file has no symbol versioning. */
680 return 0;
682 def = (ElfW(Verdef) *) ((char *) map->l_addr
683 + map->l_info[VERDEFTAG]->d_un.d_ptr);
684 while (1)
686 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
688 /* Compare the version strings. */
689 if (strcmp (string, strtab + aux->vda_name) == 0)
690 /* Bingo! */
691 return 1;
693 /* If no more definitions we failed to find what we want. */
694 if (def->vd_next == 0)
695 break;
697 /* Next definition. */
698 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
701 return 0;
704 static bool tls_init_tp_called;
706 static void *
707 init_tls (void)
709 /* Number of elements in the static TLS block. */
710 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
712 /* Do not do this twice. The audit interface might have required
713 the DTV interfaces to be set up early. */
714 if (GL(dl_initial_dtv) != NULL)
715 return NULL;
717 /* Allocate the array which contains the information about the
718 dtv slots. We allocate a few entries more than needed to
719 avoid the need for reallocation. */
720 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
722 /* Allocate. */
723 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
724 calloc (sizeof (struct dtv_slotinfo_list)
725 + nelem * sizeof (struct dtv_slotinfo), 1);
726 /* No need to check the return value. If memory allocation failed
727 the program would have been terminated. */
729 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
730 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
731 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
733 /* Fill in the information from the loaded modules. No namespace
734 but the base one can be filled at this time. */
735 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
736 int i = 0;
737 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
738 l = l->l_next)
739 if (l->l_tls_blocksize != 0)
741 /* This is a module with TLS data. Store the map reference.
742 The generation counter is zero. */
743 slotinfo[i].map = l;
744 /* slotinfo[i].gen = 0; */
745 ++i;
747 assert (i == GL(dl_tls_max_dtv_idx));
749 /* Compute the TLS offsets for the various blocks. */
750 _dl_determine_tlsoffset ();
752 /* Construct the static TLS block and the dtv for the initial
753 thread. For some platforms this will include allocating memory
754 for the thread descriptor. The memory for the TLS block will
755 never be freed. It should be allocated accordingly. The dtv
756 array can be changed if dynamic loading requires it. */
757 void *tcbp = _dl_allocate_tls_storage ();
758 if (tcbp == NULL)
759 _dl_fatal_printf ("\
760 cannot allocate TLS data structures for initial thread");
762 /* Store for detection of the special case by __tls_get_addr
763 so it knows not to pass this dtv to the normal realloc. */
764 GL(dl_initial_dtv) = GET_DTV (tcbp);
766 /* And finally install it for the main thread. If ld.so itself uses
767 TLS we know the thread pointer was initialized earlier. */
768 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
769 if (__builtin_expect (lossage != NULL, 0))
770 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
771 tls_init_tp_called = true;
773 return tcbp;
776 #ifdef _LIBC_REENTRANT
777 /* _dl_error_catch_tsd points to this for the single-threaded case.
778 It's reset by the thread library for multithreaded programs. */
779 void ** __attribute__ ((const))
780 _dl_initial_error_catch_tsd (void)
782 static void *data;
783 return &data;
785 #endif
788 static unsigned int
789 do_preload (char *fname, struct link_map *main_map, const char *where)
791 const char *objname;
792 const char *err_str = NULL;
793 struct map_args args;
794 bool malloced;
796 args.str = fname;
797 args.loader = main_map;
798 args.is_preloaded = 1;
799 args.mode = 0;
801 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
803 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
804 if (__builtin_expect (err_str != NULL, 0))
806 _dl_error_printf ("\
807 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
808 fname, where);
809 /* No need to call free, this is still before
810 the libc's malloc is used. */
812 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
813 /* It is no duplicate. */
814 return 1;
816 /* Nothing loaded. */
817 return 0;
820 #if defined SHARED && defined _LIBC_REENTRANT \
821 && defined __rtld_lock_default_lock_recursive
822 static void
823 rtld_lock_default_lock_recursive (void *lock)
825 __rtld_lock_default_lock_recursive (lock);
828 static void
829 rtld_lock_default_unlock_recursive (void *lock)
831 __rtld_lock_default_unlock_recursive (lock);
833 #endif
836 static void
837 security_init (void)
839 /* Set up the stack checker's canary. */
840 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
841 #ifdef THREAD_SET_STACK_GUARD
842 THREAD_SET_STACK_GUARD (stack_chk_guard);
843 #else
844 __stack_chk_guard = stack_chk_guard;
845 #endif
847 /* Set up the pointer guard as well, if necessary. */
848 if (GLRO(dl_pointer_guard))
850 // XXX If it is cheap, we should use a separate value.
851 uintptr_t pointer_chk_guard = stack_chk_guard;
852 #ifndef HP_TIMING_NONAVAIL
853 hp_timing_t now;
854 HP_TIMING_NOW (now);
855 pointer_chk_guard ^= now;
856 #endif
857 #ifdef THREAD_SET_POINTER_GUARD
858 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
859 #endif
860 __pointer_chk_guard_local = pointer_chk_guard;
865 /* The library search path. */
866 static const char *library_path attribute_relro;
867 /* The list preloaded objects. */
868 static const char *preloadlist attribute_relro;
869 /* Nonzero if information about versions has to be printed. */
870 static int version_info attribute_relro;
872 static void
873 dl_main (const ElfW(Phdr) *phdr,
874 ElfW(Word) phnum,
875 ElfW(Addr) *user_entry)
877 const ElfW(Phdr) *ph;
878 enum mode mode;
879 struct link_map *main_map;
880 size_t file_size;
881 char *file;
882 bool has_interp = false;
883 unsigned int i;
884 bool prelinked = false;
885 bool rtld_is_main = false;
886 #ifndef HP_TIMING_NONAVAIL
887 hp_timing_t start;
888 hp_timing_t stop;
889 hp_timing_t diff;
890 #endif
891 void *tcbp = NULL;
893 #ifdef _LIBC_REENTRANT
894 /* Explicit initialization since the reloc would just be more work. */
895 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
896 #endif
898 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
900 #if defined SHARED && defined _LIBC_REENTRANT \
901 && defined __rtld_lock_default_lock_recursive
902 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
903 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
904 #endif
906 /* The explicit initialization here is cheaper than processing the reloc
907 in the _rtld_local definition's initializer. */
908 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
910 /* Process the environment variable which control the behaviour. */
911 process_envvars (&mode);
913 #ifndef HAVE_INLINED_SYSCALLS
914 /* Set up a flag which tells we are just starting. */
915 INTUSE(_dl_starting_up) = 1;
916 #endif
918 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
920 /* Ho ho. We are not the program interpreter! We are the program
921 itself! This means someone ran ld.so as a command. Well, that
922 might be convenient to do sometimes. We support it by
923 interpreting the args like this:
925 ld.so PROGRAM ARGS...
927 The first argument is the name of a file containing an ELF
928 executable we will load and run with the following arguments.
929 To simplify life here, PROGRAM is searched for using the
930 normal rules for shared objects, rather than $PATH or anything
931 like that. We just load it and use its entry point; we don't
932 pay attention to its PT_INTERP command (we are the interpreter
933 ourselves). This is an easy way to test a new ld.so before
934 installing it. */
935 rtld_is_main = true;
937 /* Note the place where the dynamic linker actually came from. */
938 GL(dl_rtld_map).l_name = rtld_progname;
940 while (_dl_argc > 1)
941 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
943 mode = list;
944 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
946 ++_dl_skip_args;
947 --_dl_argc;
948 ++INTUSE(_dl_argv);
950 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
952 mode = verify;
954 ++_dl_skip_args;
955 --_dl_argc;
956 ++INTUSE(_dl_argv);
958 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
959 && _dl_argc > 2)
961 library_path = INTUSE(_dl_argv)[2];
963 _dl_skip_args += 2;
964 _dl_argc -= 2;
965 INTUSE(_dl_argv) += 2;
967 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
968 && _dl_argc > 2)
970 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
972 _dl_skip_args += 2;
973 _dl_argc -= 2;
974 INTUSE(_dl_argv) += 2;
976 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
978 process_dl_audit (INTUSE(_dl_argv)[2]);
980 _dl_skip_args += 2;
981 _dl_argc -= 2;
982 INTUSE(_dl_argv) += 2;
984 else
985 break;
987 /* If we have no further argument the program was called incorrectly.
988 Grant the user some education. */
989 if (_dl_argc < 2)
990 _dl_fatal_printf ("\
991 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
992 You have invoked `ld.so', the helper program for shared library executables.\n\
993 This program usually lives in the file `/lib/ld.so', and special directives\n\
994 in executable files using ELF shared libraries tell the system's program\n\
995 loader to load the helper program from this file. This helper program loads\n\
996 the shared libraries needed by the program executable, prepares the program\n\
997 to run, and runs it. You may invoke this helper program directly from the\n\
998 command line to load and run an ELF executable file; this is like executing\n\
999 that file itself, but always uses this helper program from the file you\n\
1000 specified, instead of the helper program file specified in the executable\n\
1001 file you run. This is mostly of use for maintainers to test new versions\n\
1002 of this helper program; chances are you did not intend to run this program.\n\
1004 --list list all dependencies and how they are resolved\n\
1005 --verify verify that given object really is a dynamically linked\n\
1006 object we can handle\n\
1007 --library-path PATH use given PATH instead of content of the environment\n\
1008 variable LD_LIBRARY_PATH\n\
1009 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1010 in LIST\n");
1012 ++_dl_skip_args;
1013 --_dl_argc;
1014 ++INTUSE(_dl_argv);
1016 /* The initialization of _dl_stack_flags done below assumes the
1017 executable's PT_GNU_STACK may have been honored by the kernel, and
1018 so a PT_GNU_STACK with PF_X set means the stack started out with
1019 execute permission. However, this is not really true if the
1020 dynamic linker is the executable the kernel loaded. For this
1021 case, we must reinitialize _dl_stack_flags to match the dynamic
1022 linker itself. If the dynamic linker was built with a
1023 PT_GNU_STACK, then the kernel may have loaded us with a
1024 nonexecutable stack that we will have to make executable when we
1025 load the program below unless it has a PT_GNU_STACK indicating
1026 nonexecutable stack is ok. */
1028 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1029 if (ph->p_type == PT_GNU_STACK)
1031 GL(dl_stack_flags) = ph->p_flags;
1032 break;
1035 if (__builtin_expect (mode, normal) == verify)
1037 const char *objname;
1038 const char *err_str = NULL;
1039 struct map_args args;
1040 bool malloced;
1042 args.str = rtld_progname;
1043 args.loader = NULL;
1044 args.is_preloaded = 0;
1045 args.mode = __RTLD_OPENEXEC;
1046 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1047 &args);
1048 if (__builtin_expect (err_str != NULL, 0))
1049 /* We don't free the returned string, the programs stops
1050 anyway. */
1051 _exit (EXIT_FAILURE);
1053 else
1055 HP_TIMING_NOW (start);
1056 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1057 __RTLD_OPENEXEC, LM_ID_BASE);
1058 HP_TIMING_NOW (stop);
1060 HP_TIMING_DIFF (load_time, start, stop);
1063 /* Now the map for the main executable is available. */
1064 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1066 phdr = main_map->l_phdr;
1067 phnum = main_map->l_phnum;
1068 /* We overwrite here a pointer to a malloc()ed string. But since
1069 the malloc() implementation used at this point is the dummy
1070 implementations which has no real free() function it does not
1071 makes sense to free the old string first. */
1072 main_map->l_name = (char *) "";
1073 *user_entry = main_map->l_entry;
1075 else
1077 /* Create a link_map for the executable itself.
1078 This will be what dlopen on "" returns. */
1079 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1080 __RTLD_OPENEXEC, LM_ID_BASE);
1081 assert (main_map != NULL);
1082 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1083 main_map->l_phdr = phdr;
1084 main_map->l_phnum = phnum;
1085 main_map->l_entry = *user_entry;
1087 /* At this point we are in a bit of trouble. We would have to
1088 fill in the values for l_dev and l_ino. But in general we
1089 do not know where the file is. We also do not handle AT_EXECFD
1090 even if it would be passed up.
1092 We leave the values here defined to 0. This is normally no
1093 problem as the program code itself is normally no shared
1094 object and therefore cannot be loaded dynamically. Nothing
1095 prevent the use of dynamic binaries and in these situations
1096 we might get problems. We might not be able to find out
1097 whether the object is already loaded. But since there is no
1098 easy way out and because the dynamic binary must also not
1099 have an SONAME we ignore this program for now. If it becomes
1100 a problem we can force people using SONAMEs. */
1102 /* We delay initializing the path structure until we got the dynamic
1103 information for the program. */
1106 main_map->l_map_end = 0;
1107 main_map->l_text_end = 0;
1108 /* Perhaps the executable has no PT_LOAD header entries at all. */
1109 main_map->l_map_start = ~0;
1110 /* And it was opened directly. */
1111 ++main_map->l_direct_opencount;
1113 /* Scan the program header table for the dynamic section. */
1114 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1115 switch (ph->p_type)
1117 case PT_PHDR:
1118 /* Find out the load address. */
1119 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1120 break;
1121 case PT_DYNAMIC:
1122 /* This tells us where to find the dynamic section,
1123 which tells us everything we need to do. */
1124 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1125 break;
1126 case PT_INTERP:
1127 /* This "interpreter segment" was used by the program loader to
1128 find the program interpreter, which is this program itself, the
1129 dynamic linker. We note what name finds us, so that a future
1130 dlopen call or DT_NEEDED entry, for something that wants to link
1131 against the dynamic linker as a shared library, will know that
1132 the shared object is already loaded. */
1133 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1134 + ph->p_vaddr);
1135 /* _dl_rtld_libname.next = NULL; Already zero. */
1136 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1138 /* Ordinarilly, we would get additional names for the loader from
1139 our DT_SONAME. This can't happen if we were actually linked as
1140 a static executable (detect this case when we have no DYNAMIC).
1141 If so, assume the filename component of the interpreter path to
1142 be our SONAME, and add it to our name list. */
1143 if (GL(dl_rtld_map).l_ld == NULL)
1145 const char *p = NULL;
1146 const char *cp = _dl_rtld_libname.name;
1148 /* Find the filename part of the path. */
1149 while (*cp != '\0')
1150 if (*cp++ == '/')
1151 p = cp;
1153 if (p != NULL)
1155 _dl_rtld_libname2.name = p;
1156 /* _dl_rtld_libname2.next = NULL; Already zero. */
1157 _dl_rtld_libname.next = &_dl_rtld_libname2;
1161 has_interp = true;
1162 break;
1163 case PT_LOAD:
1165 ElfW(Addr) mapstart;
1166 ElfW(Addr) allocend;
1168 /* Remember where the main program starts in memory. */
1169 mapstart = (main_map->l_addr
1170 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1171 if (main_map->l_map_start > mapstart)
1172 main_map->l_map_start = mapstart;
1174 /* Also where it ends. */
1175 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1176 if (main_map->l_map_end < allocend)
1177 main_map->l_map_end = allocend;
1178 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1179 main_map->l_text_end = allocend;
1181 break;
1183 case PT_TLS:
1184 if (ph->p_memsz > 0)
1186 /* Note that in the case the dynamic linker we duplicate work
1187 here since we read the PT_TLS entry already in
1188 _dl_start_final. But the result is repeatable so do not
1189 check for this special but unimportant case. */
1190 main_map->l_tls_blocksize = ph->p_memsz;
1191 main_map->l_tls_align = ph->p_align;
1192 if (ph->p_align == 0)
1193 main_map->l_tls_firstbyte_offset = 0;
1194 else
1195 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1196 & (ph->p_align - 1));
1197 main_map->l_tls_initimage_size = ph->p_filesz;
1198 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1200 /* This image gets the ID one. */
1201 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1203 break;
1205 case PT_GNU_STACK:
1206 GL(dl_stack_flags) = ph->p_flags;
1207 break;
1209 case PT_GNU_RELRO:
1210 main_map->l_relro_addr = ph->p_vaddr;
1211 main_map->l_relro_size = ph->p_memsz;
1212 break;
1215 /* Adjust the address of the TLS initialization image in case
1216 the executable is actually an ET_DYN object. */
1217 if (main_map->l_tls_initimage != NULL)
1218 main_map->l_tls_initimage
1219 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1220 if (! main_map->l_map_end)
1221 main_map->l_map_end = ~0;
1222 if (! main_map->l_text_end)
1223 main_map->l_text_end = ~0;
1224 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1226 /* We were invoked directly, so the program might not have a
1227 PT_INTERP. */
1228 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1229 /* _dl_rtld_libname.next = NULL; Already zero. */
1230 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1232 else
1233 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1235 /* If the current libname is different from the SONAME, add the
1236 latter as well. */
1237 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1238 && strcmp (GL(dl_rtld_map).l_libname->name,
1239 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1240 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1242 static struct libname_list newname;
1243 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1244 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1245 newname.next = NULL;
1246 newname.dont_free = 1;
1248 assert (GL(dl_rtld_map).l_libname->next == NULL);
1249 GL(dl_rtld_map).l_libname->next = &newname;
1251 /* The ld.so must be relocated since otherwise loading audit modules
1252 will fail since they reuse the very same ld.so. */
1253 assert (GL(dl_rtld_map).l_relocated);
1255 if (! rtld_is_main)
1257 /* Extract the contents of the dynamic section for easy access. */
1258 elf_get_dynamic_info (main_map, NULL);
1259 /* Set up our cache of pointers into the hash table. */
1260 _dl_setup_hash (main_map);
1263 if (__builtin_expect (mode, normal) == verify)
1265 /* We were called just to verify that this is a dynamic
1266 executable using us as the program interpreter. Exit with an
1267 error if we were not able to load the binary or no interpreter
1268 is specified (i.e., this is no dynamically linked binary. */
1269 if (main_map->l_ld == NULL)
1270 _exit (1);
1272 /* We allow here some platform specific code. */
1273 #ifdef DISTINGUISH_LIB_VERSIONS
1274 DISTINGUISH_LIB_VERSIONS;
1275 #endif
1276 _exit (has_interp ? 0 : 2);
1279 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1280 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1281 /* Set up the data structures for the system-supplied DSO early,
1282 so they can influence _dl_init_paths. */
1283 if (GLRO(dl_sysinfo_dso) != NULL)
1285 /* Do an abridged version of the work _dl_map_object_from_fd would do
1286 to map in the object. It's already mapped and prelinked (and
1287 better be, since it's read-only and so we couldn't relocate it).
1288 We just want our data structures to describe it as if we had just
1289 mapped and relocated it normally. */
1290 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1291 0, LM_ID_BASE);
1292 if (__builtin_expect (l != NULL, 1))
1294 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1296 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1297 + GLRO(dl_sysinfo_dso)->e_phoff);
1298 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1299 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1301 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1302 if (ph->p_type == PT_DYNAMIC)
1304 l->l_ld = (void *) ph->p_vaddr;
1305 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1307 else if (ph->p_type == PT_LOAD)
1309 if (! l->l_addr)
1310 l->l_addr = ph->p_vaddr;
1311 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1312 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1313 if ((ph->p_flags & PF_X)
1314 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1315 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1317 else
1318 /* There must be no TLS segment. */
1319 assert (ph->p_type != PT_TLS);
1321 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1322 l->l_addr = l->l_map_start - l->l_addr;
1323 l->l_map_end += l->l_addr;
1324 l->l_text_end += l->l_addr;
1325 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1326 elf_get_dynamic_info (l, dyn_temp);
1327 _dl_setup_hash (l);
1328 l->l_relocated = 1;
1330 /* Initialize l_local_scope to contain just this map. This allows
1331 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1332 So we create a single entry list pointing to l_real as its only
1333 element */
1334 l->l_local_scope[0]->r_nlist = 1;
1335 l->l_local_scope[0]->r_list = &l->l_real;
1337 /* Now that we have the info handy, use the DSO image's soname
1338 so this object can be looked up by name. Note that we do not
1339 set l_name here. That field gives the file name of the DSO,
1340 and this DSO is not associated with any file. */
1341 if (l->l_info[DT_SONAME] != NULL)
1343 /* Work around a kernel problem. The kernel cannot handle
1344 addresses in the vsyscall DSO pages in writev() calls. */
1345 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1346 + l->l_info[DT_SONAME]->d_un.d_val);
1347 size_t len = strlen (dsoname);
1348 char *copy = malloc (len);
1349 if (copy == NULL)
1350 _dl_fatal_printf ("out of memory\n");
1351 l->l_libname->name = memcpy (copy, dsoname, len);
1354 /* Rearrange the list so this DSO appears after rtld_map. */
1355 assert (l->l_next == NULL);
1356 assert (l->l_prev == main_map);
1357 GL(dl_rtld_map).l_next = l;
1358 l->l_prev = &GL(dl_rtld_map);
1359 first_preload = &l->l_next;
1361 /* We have a prelinked DSO preloaded by the system. */
1362 GLRO(dl_sysinfo_map) = l;
1363 # ifdef NEED_DL_SYSINFO
1364 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1365 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1366 # endif
1369 #endif
1371 #ifdef DL_SYSDEP_OSCHECK
1372 DL_SYSDEP_OSCHECK (dl_fatal);
1373 #endif
1375 /* Initialize the data structures for the search paths for shared
1376 objects. */
1377 _dl_init_paths (library_path);
1379 /* Initialize _r_debug. */
1380 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1381 LM_ID_BASE);
1382 r->r_state = RT_CONSISTENT;
1384 /* Put the link_map for ourselves on the chain so it can be found by
1385 name. Note that at this point the global chain of link maps contains
1386 exactly one element, which is pointed to by dl_loaded. */
1387 if (! GL(dl_rtld_map).l_name)
1388 /* If not invoked directly, the dynamic linker shared object file was
1389 found by the PT_INTERP name. */
1390 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1391 GL(dl_rtld_map).l_type = lt_library;
1392 main_map->l_next = &GL(dl_rtld_map);
1393 GL(dl_rtld_map).l_prev = main_map;
1394 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1395 ++GL(dl_load_adds);
1397 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1398 to not using bias for non-prelinked PIEs and libraries
1399 and using it for executables or prelinked PIEs or libraries. */
1400 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1401 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1403 /* Set up the program header information for the dynamic linker
1404 itself. It is needed in the dl_iterate_phdr() callbacks. */
1405 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1406 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1407 + rtld_ehdr->e_phoff);
1408 GL(dl_rtld_map).l_phdr = rtld_phdr;
1409 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1412 /* PT_GNU_RELRO is usually the last phdr. */
1413 size_t cnt = rtld_ehdr->e_phnum;
1414 while (cnt-- > 0)
1415 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1417 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1418 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1419 break;
1422 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1423 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1424 /* Assign a module ID. Do this before loading any audit modules. */
1425 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1427 /* If we have auditing DSOs to load, do it now. */
1428 if (__builtin_expect (audit_list != NULL, 0))
1430 /* Iterate over all entries in the list. The order is important. */
1431 struct audit_ifaces *last_audit = NULL;
1432 struct audit_list *al = audit_list->next;
1434 /* Since we start using the auditing DSOs right away we need to
1435 initialize the data structures now. */
1436 tcbp = init_tls ();
1438 /* Initialize security features. We need to do it this early
1439 since otherwise the constructors of the audit libraries will
1440 use different values (especially the pointer guard) and will
1441 fail later on. */
1442 security_init ();
1446 int tls_idx = GL(dl_tls_max_dtv_idx);
1448 /* Now it is time to determine the layout of the static TLS
1449 block and allocate it for the initial thread. Note that we
1450 always allocate the static block, we never defer it even if
1451 no DF_STATIC_TLS bit is set. The reason is that we know
1452 glibc will use the static model. */
1453 struct dlmopen_args dlmargs;
1454 dlmargs.fname = al->name;
1455 dlmargs.map = NULL;
1457 const char *objname;
1458 const char *err_str = NULL;
1459 bool malloced;
1460 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1461 &dlmargs);
1462 if (__builtin_expect (err_str != NULL, 0))
1464 not_loaded:
1465 _dl_error_printf ("\
1466 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1467 al->name, err_str);
1468 if (malloced)
1469 free ((char *) err_str);
1471 else
1473 struct lookup_args largs;
1474 largs.name = "la_version";
1475 largs.map = dlmargs.map;
1477 /* Check whether the interface version matches. */
1478 (void) _dl_catch_error (&objname, &err_str, &malloced,
1479 lookup_doit, &largs);
1481 unsigned int (*laversion) (unsigned int);
1482 unsigned int lav;
1483 if (err_str == NULL
1484 && (laversion = largs.result) != NULL
1485 && (lav = laversion (LAV_CURRENT)) > 0
1486 && lav <= LAV_CURRENT)
1488 /* Allocate structure for the callback function pointers.
1489 This call can never fail. */
1490 union
1492 struct audit_ifaces ifaces;
1493 #define naudit_ifaces 8
1494 void (*fptr[naudit_ifaces]) (void);
1495 } *newp = malloc (sizeof (*newp));
1497 /* Names of the auditing interfaces. All in one
1498 long string. */
1499 static const char audit_iface_names[] =
1500 "la_activity\0"
1501 "la_objsearch\0"
1502 "la_objopen\0"
1503 "la_preinit\0"
1504 #if __ELF_NATIVE_CLASS == 32
1505 "la_symbind32\0"
1506 #elif __ELF_NATIVE_CLASS == 64
1507 "la_symbind64\0"
1508 #else
1509 # error "__ELF_NATIVE_CLASS must be defined"
1510 #endif
1511 #define STRING(s) __STRING (s)
1512 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1513 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1514 "la_objclose\0";
1515 unsigned int cnt = 0;
1516 const char *cp = audit_iface_names;
1519 largs.name = cp;
1520 (void) _dl_catch_error (&objname, &err_str, &malloced,
1521 lookup_doit, &largs);
1523 /* Store the pointer. */
1524 if (err_str == NULL && largs.result != NULL)
1526 newp->fptr[cnt] = largs.result;
1528 /* The dynamic linker link map is statically
1529 allocated, initialize the data now. */
1530 GL(dl_rtld_map).l_audit[cnt].cookie
1531 = (intptr_t) &GL(dl_rtld_map);
1533 else
1534 newp->fptr[cnt] = NULL;
1535 ++cnt;
1537 cp = (char *) rawmemchr (cp, '\0') + 1;
1539 while (*cp != '\0');
1540 assert (cnt == naudit_ifaces);
1542 /* Now append the new auditing interface to the list. */
1543 newp->ifaces.next = NULL;
1544 if (last_audit == NULL)
1545 last_audit = GLRO(dl_audit) = &newp->ifaces;
1546 else
1547 last_audit = last_audit->next = &newp->ifaces;
1548 ++GLRO(dl_naudit);
1550 /* Mark the DSO as being used for auditing. */
1551 dlmargs.map->l_auditing = 1;
1553 else
1555 /* We cannot use the DSO, it does not have the
1556 appropriate interfaces or it expects something
1557 more recent. */
1558 #ifndef NDEBUG
1559 Lmid_t ns = dlmargs.map->l_ns;
1560 #endif
1561 _dl_close (dlmargs.map);
1563 /* Make sure the namespace has been cleared entirely. */
1564 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1565 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1567 GL(dl_tls_max_dtv_idx) = tls_idx;
1568 goto not_loaded;
1572 al = al->next;
1574 while (al != audit_list->next);
1576 /* If we have any auditing modules, announce that we already
1577 have two objects loaded. */
1578 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1580 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1582 for (unsigned int outer = 0; outer < 2; ++outer)
1584 struct audit_ifaces *afct = GLRO(dl_audit);
1585 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1587 if (afct->objopen != NULL)
1589 ls[outer]->l_audit[cnt].bindflags
1590 = afct->objopen (ls[outer], LM_ID_BASE,
1591 &ls[outer]->l_audit[cnt].cookie);
1593 ls[outer]->l_audit_any_plt
1594 |= ls[outer]->l_audit[cnt].bindflags != 0;
1597 afct = afct->next;
1603 /* Set up debugging before the debugger is notified for the first time. */
1604 #ifdef ELF_MACHINE_DEBUG_SETUP
1605 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1606 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1607 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1608 #else
1609 if (main_map->l_info[DT_DEBUG] != NULL)
1610 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1611 with the run-time address of the r_debug structure */
1612 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1614 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1615 case you run gdb on the dynamic linker directly. */
1616 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1617 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1618 #endif
1620 /* We start adding objects. */
1621 r->r_state = RT_ADD;
1622 _dl_debug_state ();
1624 /* Auditing checkpoint: we are ready to signal that the initial map
1625 is being constructed. */
1626 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1628 struct audit_ifaces *afct = GLRO(dl_audit);
1629 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1631 if (afct->activity != NULL)
1632 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1634 afct = afct->next;
1638 /* We have two ways to specify objects to preload: via environment
1639 variable and via the file /etc/ld.so.preload. The latter can also
1640 be used when security is enabled. */
1641 assert (*first_preload == NULL);
1642 struct link_map **preloads = NULL;
1643 unsigned int npreloads = 0;
1645 if (__builtin_expect (preloadlist != NULL, 0))
1647 /* The LD_PRELOAD environment variable gives list of libraries
1648 separated by white space or colons that are loaded before the
1649 executable's dependencies and prepended to the global scope
1650 list. If the binary is running setuid all elements
1651 containing a '/' are ignored since it is insecure. */
1652 char *list = strdupa (preloadlist);
1653 char *p;
1655 HP_TIMING_NOW (start);
1657 /* Prevent optimizing strsep. Speed is not important here. */
1658 while ((p = (strsep) (&list, " :")) != NULL)
1659 if (p[0] != '\0'
1660 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1661 || strchr (p, '/') == NULL))
1662 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1664 HP_TIMING_NOW (stop);
1665 HP_TIMING_DIFF (diff, start, stop);
1666 HP_TIMING_ACCUM_NT (load_time, diff);
1669 /* There usually is no ld.so.preload file, it should only be used
1670 for emergencies and testing. So the open call etc should usually
1671 fail. Using access() on a non-existing file is faster than using
1672 open(). So we do this first. If it succeeds we do almost twice
1673 the work but this does not matter, since it is not for production
1674 use. */
1675 static const char preload_file[] = "/etc/ld.so.preload";
1676 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1678 /* Read the contents of the file. */
1679 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1680 PROT_READ | PROT_WRITE);
1681 if (__builtin_expect (file != MAP_FAILED, 0))
1683 /* Parse the file. It contains names of libraries to be loaded,
1684 separated by white spaces or `:'. It may also contain
1685 comments introduced by `#'. */
1686 char *problem;
1687 char *runp;
1688 size_t rest;
1690 /* Eliminate comments. */
1691 runp = file;
1692 rest = file_size;
1693 while (rest > 0)
1695 char *comment = memchr (runp, '#', rest);
1696 if (comment == NULL)
1697 break;
1699 rest -= comment - runp;
1701 *comment = ' ';
1702 while (--rest > 0 && *++comment != '\n');
1705 /* We have one problematic case: if we have a name at the end of
1706 the file without a trailing terminating characters, we cannot
1707 place the \0. Handle the case separately. */
1708 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1709 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1711 problem = &file[file_size];
1712 while (problem > file && problem[-1] != ' '
1713 && problem[-1] != '\t'
1714 && problem[-1] != '\n' && problem[-1] != ':')
1715 --problem;
1717 if (problem > file)
1718 problem[-1] = '\0';
1720 else
1722 problem = NULL;
1723 file[file_size - 1] = '\0';
1726 HP_TIMING_NOW (start);
1728 if (file != problem)
1730 char *p;
1731 runp = file;
1732 while ((p = strsep (&runp, ": \t\n")) != NULL)
1733 if (p[0] != '\0')
1734 npreloads += do_preload (p, main_map, preload_file);
1737 if (problem != NULL)
1739 char *p = strndupa (problem, file_size - (problem - file));
1741 npreloads += do_preload (p, main_map, preload_file);
1744 HP_TIMING_NOW (stop);
1745 HP_TIMING_DIFF (diff, start, stop);
1746 HP_TIMING_ACCUM_NT (load_time, diff);
1748 /* We don't need the file anymore. */
1749 __munmap (file, file_size);
1753 if (__builtin_expect (*first_preload != NULL, 0))
1755 /* Set up PRELOADS with a vector of the preloaded libraries. */
1756 struct link_map *l = *first_preload;
1757 preloads = __alloca (npreloads * sizeof preloads[0]);
1758 i = 0;
1761 preloads[i++] = l;
1762 l = l->l_next;
1763 } while (l);
1764 assert (i == npreloads);
1767 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1768 specified some libraries to load, these are inserted before the actual
1769 dependencies in the executable's searchlist for symbol resolution. */
1770 HP_TIMING_NOW (start);
1771 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1772 HP_TIMING_NOW (stop);
1773 HP_TIMING_DIFF (diff, start, stop);
1774 HP_TIMING_ACCUM_NT (load_time, diff);
1776 /* Mark all objects as being in the global scope. */
1777 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1778 main_map->l_searchlist.r_list[--i]->l_global = 1;
1780 #ifndef MAP_ANON
1781 /* We are done mapping things, so close the zero-fill descriptor. */
1782 __close (_dl_zerofd);
1783 _dl_zerofd = -1;
1784 #endif
1786 /* Remove _dl_rtld_map from the chain. */
1787 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1788 if (GL(dl_rtld_map).l_next != NULL)
1789 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1791 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1792 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1793 break;
1795 bool rtld_multiple_ref = false;
1796 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1798 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1799 put it back in the list of visible objects. We insert it into the
1800 chain in symbol search order because gdb uses the chain's order as
1801 its symbol search order. */
1802 rtld_multiple_ref = true;
1804 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1805 if (__builtin_expect (mode, normal) == normal)
1807 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1808 ? main_map->l_searchlist.r_list[i + 1]
1809 : NULL);
1810 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1811 if (GLRO(dl_sysinfo_map) != NULL
1812 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1813 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1814 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1815 #endif
1817 else
1818 /* In trace mode there might be an invisible object (which we
1819 could not find) after the previous one in the search list.
1820 In this case it doesn't matter much where we put the
1821 interpreter object, so we just initialize the list pointer so
1822 that the assertion below holds. */
1823 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1825 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1826 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1827 if (GL(dl_rtld_map).l_next != NULL)
1829 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1830 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1834 /* Now let us see whether all libraries are available in the
1835 versions we need. */
1837 struct version_check_args args;
1838 args.doexit = mode == normal;
1839 args.dotrace = mode == trace;
1840 _dl_receive_error (print_missing_version, version_check_doit, &args);
1843 /* We do not initialize any of the TLS functionality unless any of the
1844 initial modules uses TLS. This makes dynamic loading of modules with
1845 TLS impossible, but to support it requires either eagerly doing setup
1846 now or lazily doing it later. Doing it now makes us incompatible with
1847 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1848 used. Trying to do it lazily is too hairy to try when there could be
1849 multiple threads (from a non-TLS-using libpthread). */
1850 bool was_tls_init_tp_called = tls_init_tp_called;
1851 if (tcbp == NULL)
1852 tcbp = init_tls ();
1854 if (__builtin_expect (audit_list == NULL, 1))
1855 /* Initialize security features. But only if we have not done it
1856 earlier. */
1857 security_init ();
1859 if (__builtin_expect (mode, normal) != normal)
1861 /* We were run just to list the shared libraries. It is
1862 important that we do this before real relocation, because the
1863 functions we call below for output may no longer work properly
1864 after relocation. */
1865 struct link_map *l;
1867 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1869 struct r_scope_elem *scope = &main_map->l_searchlist;
1871 for (i = 0; i < scope->r_nlist; i++)
1873 l = scope->r_list [i];
1874 if (l->l_faked)
1876 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1877 continue;
1879 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1880 GLRO(dl_trace_prelink_map) = l;
1881 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1882 l->l_libname->name[0] ? l->l_libname->name
1883 : rtld_progname ?: "<main program>",
1884 l->l_name[0] ? l->l_name
1885 : rtld_progname ?: "<main program>",
1886 (int) sizeof l->l_map_start * 2,
1887 (size_t) l->l_map_start,
1888 (int) sizeof l->l_addr * 2,
1889 (size_t) l->l_addr);
1891 if (l->l_tls_modid)
1892 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1893 (int) sizeof l->l_tls_offset * 2,
1894 (size_t) l->l_tls_offset);
1895 else
1896 _dl_printf ("\n");
1899 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1901 /* Look through the dependencies of the main executable
1902 and determine which of them is not actually
1903 required. */
1904 struct link_map *l = main_map;
1906 /* Relocate the main executable. */
1907 struct relocate_args args = { .l = l, .lazy = GLRO(dl_lazy) };
1908 _dl_receive_error (print_unresolved, relocate_doit, &args);
1910 /* This loop depends on the dependencies of the executable to
1911 correspond in number and order to the DT_NEEDED entries. */
1912 ElfW(Dyn) *dyn = main_map->l_ld;
1913 bool first = true;
1914 while (dyn->d_tag != DT_NULL)
1916 if (dyn->d_tag == DT_NEEDED)
1918 l = l->l_next;
1920 if (!l->l_used)
1922 if (first)
1924 _dl_printf ("Unused direct dependencies:\n");
1925 first = false;
1928 _dl_printf ("\t%s\n", l->l_name);
1932 ++dyn;
1935 _exit (first != true);
1937 else if (! main_map->l_info[DT_NEEDED])
1938 _dl_printf ("\tstatically linked\n");
1939 else
1941 for (l = main_map->l_next; l; l = l->l_next)
1942 if (l->l_faked)
1943 /* The library was not found. */
1944 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1945 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1946 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1947 (int) sizeof l->l_map_start * 2,
1948 (size_t) l->l_map_start);
1949 else
1950 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1951 l->l_name, (int) sizeof l->l_map_start * 2,
1952 (size_t) l->l_map_start);
1955 if (__builtin_expect (mode, trace) != trace)
1956 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1958 const ElfW(Sym) *ref = NULL;
1959 ElfW(Addr) loadbase;
1960 lookup_t result;
1962 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1963 &ref, main_map->l_scope,
1964 NULL, ELF_RTYPE_CLASS_PLT,
1965 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1967 loadbase = LOOKUP_VALUE_ADDRESS (result);
1969 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1970 INTUSE(_dl_argv)[i],
1971 (int) sizeof ref->st_value * 2,
1972 (size_t) ref->st_value,
1973 (int) sizeof loadbase * 2, (size_t) loadbase);
1975 else
1977 /* If LD_WARN is set, warn about undefined symbols. */
1978 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1980 /* We have to do symbol dependency testing. */
1981 struct relocate_args args;
1982 struct link_map *l;
1984 args.lazy = GLRO(dl_lazy);
1986 l = main_map;
1987 while (l->l_next != NULL)
1988 l = l->l_next;
1991 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1993 args.l = l;
1994 _dl_receive_error (print_unresolved, relocate_doit,
1995 &args);
1997 l = l->l_prev;
1999 while (l != NULL);
2001 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2002 && rtld_multiple_ref)
2004 /* Mark the link map as not yet relocated again. */
2005 GL(dl_rtld_map).l_relocated = 0;
2006 _dl_relocate_object (&GL(dl_rtld_map),
2007 main_map->l_scope, 0, 0);
2010 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2011 if (version_info)
2013 /* Print more information. This means here, print information
2014 about the versions needed. */
2015 int first = 1;
2016 struct link_map *map;
2018 for (map = main_map; map != NULL; map = map->l_next)
2020 const char *strtab;
2021 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2022 ElfW(Verneed) *ent;
2024 if (dyn == NULL)
2025 continue;
2027 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2028 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2030 if (first)
2032 _dl_printf ("\n\tVersion information:\n");
2033 first = 0;
2036 _dl_printf ("\t%s:\n",
2037 map->l_name[0] ? map->l_name : rtld_progname);
2039 while (1)
2041 ElfW(Vernaux) *aux;
2042 struct link_map *needed;
2044 needed = find_needed (strtab + ent->vn_file);
2045 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2047 while (1)
2049 const char *fname = NULL;
2051 if (needed != NULL
2052 && match_version (strtab + aux->vna_name,
2053 needed))
2054 fname = needed->l_name;
2056 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2057 strtab + ent->vn_file,
2058 strtab + aux->vna_name,
2059 aux->vna_flags & VER_FLG_WEAK
2060 ? "[WEAK] " : "",
2061 fname ?: "not found");
2063 if (aux->vna_next == 0)
2064 /* No more symbols. */
2065 break;
2067 /* Next symbol. */
2068 aux = (ElfW(Vernaux) *) ((char *) aux
2069 + aux->vna_next);
2072 if (ent->vn_next == 0)
2073 /* No more dependencies. */
2074 break;
2076 /* Next dependency. */
2077 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2083 _exit (0);
2086 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2087 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2088 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2090 ElfW(Lib) *liblist, *liblistend;
2091 struct link_map **r_list, **r_listend, *l;
2092 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2094 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2095 liblist = (ElfW(Lib) *)
2096 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2097 liblistend = (ElfW(Lib) *)
2098 ((char *) liblist +
2099 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2100 r_list = main_map->l_searchlist.r_list;
2101 r_listend = r_list + main_map->l_searchlist.r_nlist;
2103 for (; r_list < r_listend && liblist < liblistend; r_list++)
2105 l = *r_list;
2107 if (l == main_map)
2108 continue;
2110 /* If the library is not mapped where it should, fail. */
2111 if (l->l_addr)
2112 break;
2114 /* Next, check if checksum matches. */
2115 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2116 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2117 != liblist->l_checksum)
2118 break;
2120 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2121 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2122 != liblist->l_time_stamp)
2123 break;
2125 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2126 break;
2128 ++liblist;
2132 if (r_list == r_listend && liblist == liblistend)
2133 prelinked = true;
2135 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2136 _dl_debug_printf ("\nprelink checking: %s\n",
2137 prelinked ? "ok" : "failed");
2141 /* Now set up the variable which helps the assembler startup code. */
2142 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2144 /* Save the information about the original global scope list since
2145 we need it in the memory handling later. */
2146 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
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 _dl_sysdep_start_cleanup ();
2185 else
2187 /* Now we have all the objects loaded. Relocate them all except for
2188 the dynamic linker itself. We do this in reverse order so that copy
2189 relocs of earlier objects overwrite the data written by later
2190 objects. We do not re-relocate the dynamic linker itself in this
2191 loop because that could result in the GOT entries for functions we
2192 call being changed, and that would break us. It is safe to relocate
2193 the dynamic linker out of order because it has no copy relocs (we
2194 know that because it is self-contained). */
2196 int consider_profiling = GLRO(dl_profile) != NULL;
2197 #ifndef HP_TIMING_NONAVAIL
2198 hp_timing_t start;
2199 hp_timing_t stop;
2200 #endif
2202 /* If we are profiling we also must do lazy reloaction. */
2203 GLRO(dl_lazy) |= consider_profiling;
2205 struct link_map *l = main_map;
2206 while (l->l_next)
2207 l = l->l_next;
2209 HP_TIMING_NOW (start);
2212 /* While we are at it, help the memory handling a bit. We have to
2213 mark some data structures as allocated with the fake malloc()
2214 implementation in ld.so. */
2215 struct libname_list *lnp = l->l_libname->next;
2217 while (__builtin_expect (lnp != NULL, 0))
2219 lnp->dont_free = 1;
2220 lnp = lnp->next;
2223 if (l != &GL(dl_rtld_map))
2224 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy),
2225 consider_profiling);
2227 /* Add object to slot information data if necessasy. */
2228 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2229 _dl_add_to_slotinfo (l);
2231 l = l->l_prev;
2233 while (l);
2234 HP_TIMING_NOW (stop);
2236 HP_TIMING_DIFF (relocate_time, start, stop);
2238 /* Do any necessary cleanups for the startup OS interface code.
2239 We do these now so that no calls are made after rtld re-relocation
2240 which might be resolved to different functions than we expect.
2241 We cannot do this before relocating the other objects because
2242 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2243 _dl_sysdep_start_cleanup ();
2245 /* Now enable profiling if needed. Like the previous call,
2246 this has to go here because the calls it makes should use the
2247 rtld versions of the functions (particularly calloc()), but it
2248 needs to have _dl_profile_map set up by the relocator. */
2249 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2250 /* We must prepare the profiling. */
2251 _dl_start_profile ();
2254 #ifndef NONTLS_INIT_TP
2255 # define NONTLS_INIT_TP do { } while (0)
2256 #endif
2258 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2259 ++GL(dl_tls_generation);
2261 /* Now that we have completed relocation, the initializer data
2262 for the TLS blocks has its final values and we can copy them
2263 into the main thread's TLS area, which we allocated above. */
2264 _dl_allocate_tls_init (tcbp);
2266 /* And finally install it for the main thread. If ld.so itself uses
2267 TLS we know the thread pointer was initialized earlier. */
2268 if (! tls_init_tp_called)
2270 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2271 if (__builtin_expect (lossage != NULL, 0))
2272 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2273 lossage);
2276 if (! prelinked && rtld_multiple_ref)
2278 /* There was an explicit ref to the dynamic linker as a shared lib.
2279 Re-relocate ourselves with user-controlled symbol definitions.
2281 We must do this after TLS initialization in case after this
2282 re-relocation, we might call a user-supplied function
2283 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2285 #ifndef HP_TIMING_NONAVAIL
2286 hp_timing_t start;
2287 hp_timing_t stop;
2288 hp_timing_t add;
2289 #endif
2291 HP_TIMING_NOW (start);
2292 /* Mark the link map as not yet relocated again. */
2293 GL(dl_rtld_map).l_relocated = 0;
2294 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2295 HP_TIMING_NOW (stop);
2296 HP_TIMING_DIFF (add, start, stop);
2297 HP_TIMING_ACCUM_NT (relocate_time, add);
2300 #ifdef SHARED
2301 /* Auditing checkpoint: we have added all objects. */
2302 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2304 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2305 /* Do not call the functions for any auditing object. */
2306 if (head->l_auditing == 0)
2308 struct audit_ifaces *afct = GLRO(dl_audit);
2309 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2311 if (afct->activity != NULL)
2312 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2314 afct = afct->next;
2318 #endif
2320 /* Notify the debugger all new objects are now ready to go. We must re-get
2321 the address since by now the variable might be in another object. */
2322 r = _dl_debug_initialize (0, LM_ID_BASE);
2323 r->r_state = RT_CONSISTENT;
2324 _dl_debug_state ();
2326 #ifndef MAP_COPY
2327 /* We must munmap() the cache file. */
2328 _dl_unload_cache ();
2329 #endif
2331 /* Once we return, _dl_sysdep_start will invoke
2332 the DT_INIT functions and then *USER_ENTRY. */
2335 /* This is a little helper function for resolving symbols while
2336 tracing the binary. */
2337 static void
2338 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2339 const char *errstring)
2341 if (objname[0] == '\0')
2342 objname = rtld_progname ?: "<main program>";
2343 _dl_error_printf ("%s (%s)\n", errstring, objname);
2346 /* This is a little helper function for resolving symbols while
2347 tracing the binary. */
2348 static void
2349 print_missing_version (int errcode __attribute__ ((unused)),
2350 const char *objname, const char *errstring)
2352 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2353 objname, errstring);
2356 /* Nonzero if any of the debugging options is enabled. */
2357 static int any_debug attribute_relro;
2359 /* Process the string given as the parameter which explains which debugging
2360 options are enabled. */
2361 static void
2362 process_dl_debug (const char *dl_debug)
2364 /* When adding new entries make sure that the maximal length of a name
2365 is correctly handled in the LD_DEBUG_HELP code below. */
2366 static const struct
2368 unsigned char len;
2369 const char name[10];
2370 const char helptext[41];
2371 unsigned short int mask;
2372 } debopts[] =
2374 #define LEN_AND_STR(str) sizeof (str) - 1, str
2375 { LEN_AND_STR ("libs"), "display library search paths",
2376 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2377 { LEN_AND_STR ("reloc"), "display relocation processing",
2378 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2379 { LEN_AND_STR ("files"), "display progress for input file",
2380 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2381 { LEN_AND_STR ("symbols"), "display symbol table processing",
2382 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2383 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2384 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2385 { LEN_AND_STR ("versions"), "display version dependencies",
2386 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2387 { LEN_AND_STR ("all"), "all previous options combined",
2388 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2389 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2390 { LEN_AND_STR ("statistics"), "display relocation statistics",
2391 DL_DEBUG_STATISTICS },
2392 { LEN_AND_STR ("unused"), "determined unused DSOs",
2393 DL_DEBUG_UNUSED },
2394 { LEN_AND_STR ("help"), "display this help message and exit",
2395 DL_DEBUG_HELP },
2397 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2399 /* Skip separating white spaces and commas. */
2400 while (*dl_debug != '\0')
2402 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2404 size_t cnt;
2405 size_t len = 1;
2407 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2408 && dl_debug[len] != ',' && dl_debug[len] != ':')
2409 ++len;
2411 for (cnt = 0; cnt < ndebopts; ++cnt)
2412 if (debopts[cnt].len == len
2413 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2415 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2416 any_debug = 1;
2417 break;
2420 if (cnt == ndebopts)
2422 /* Display a warning and skip everything until next
2423 separator. */
2424 char *copy = strndupa (dl_debug, len);
2425 _dl_error_printf ("\
2426 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2429 dl_debug += len;
2430 continue;
2433 ++dl_debug;
2436 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2438 size_t cnt;
2440 _dl_printf ("\
2441 Valid options for the LD_DEBUG environment variable are:\n\n");
2443 for (cnt = 0; cnt < ndebopts; ++cnt)
2444 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2445 " " + debopts[cnt].len - 3,
2446 debopts[cnt].helptext);
2448 _dl_printf ("\n\
2449 To direct the debugging output into a file instead of standard output\n\
2450 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2451 _exit (0);
2455 static void
2456 process_dl_audit (char *str)
2458 /* The parameter is a colon separated list of DSO names. */
2459 char *p;
2461 while ((p = (strsep) (&str, ":")) != NULL)
2462 if (p[0] != '\0'
2463 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2464 || strchr (p, '/') == NULL))
2466 /* This is using the local malloc, not the system malloc. The
2467 memory can never be freed. */
2468 struct audit_list *newp = malloc (sizeof (*newp));
2469 newp->name = p;
2471 if (audit_list == NULL)
2472 audit_list = newp->next = newp;
2473 else
2475 newp->next = audit_list->next;
2476 audit_list = audit_list->next = newp;
2481 /* Process all environments variables the dynamic linker must recognize.
2482 Since all of them start with `LD_' we are a bit smarter while finding
2483 all the entries. */
2484 extern char **_environ attribute_hidden;
2487 static void
2488 process_envvars (enum mode *modep)
2490 char **runp = _environ;
2491 char *envline;
2492 enum mode mode = normal;
2493 char *debug_output = NULL;
2495 /* This is the default place for profiling data file. */
2496 GLRO(dl_profile_output)
2497 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2499 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2501 size_t len = 0;
2503 while (envline[len] != '\0' && envline[len] != '=')
2504 ++len;
2506 if (envline[len] != '=')
2507 /* This is a "LD_" variable at the end of the string without
2508 a '=' character. Ignore it since otherwise we will access
2509 invalid memory below. */
2510 continue;
2512 switch (len)
2514 case 4:
2515 /* Warning level, verbose or not. */
2516 if (memcmp (envline, "WARN", 4) == 0)
2517 GLRO(dl_verbose) = envline[5] != '\0';
2518 break;
2520 case 5:
2521 /* Debugging of the dynamic linker? */
2522 if (memcmp (envline, "DEBUG", 5) == 0)
2524 process_dl_debug (&envline[6]);
2525 break;
2527 if (memcmp (envline, "AUDIT", 5) == 0)
2528 process_dl_audit (&envline[6]);
2529 break;
2531 case 7:
2532 /* Print information about versions. */
2533 if (memcmp (envline, "VERBOSE", 7) == 0)
2535 version_info = envline[8] != '\0';
2536 break;
2539 /* List of objects to be preloaded. */
2540 if (memcmp (envline, "PRELOAD", 7) == 0)
2542 preloadlist = &envline[8];
2543 break;
2546 /* Which shared object shall be profiled. */
2547 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2548 GLRO(dl_profile) = &envline[8];
2549 break;
2551 case 8:
2552 /* Do we bind early? */
2553 if (memcmp (envline, "BIND_NOW", 8) == 0)
2555 GLRO(dl_lazy) = envline[9] == '\0';
2556 break;
2558 if (memcmp (envline, "BIND_NOT", 8) == 0)
2559 GLRO(dl_bind_not) = envline[9] != '\0';
2560 break;
2562 case 9:
2563 /* Test whether we want to see the content of the auxiliary
2564 array passed up from the kernel. */
2565 if (!INTUSE(__libc_enable_secure)
2566 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2567 _dl_show_auxv ();
2568 break;
2570 case 10:
2571 /* Mask for the important hardware capabilities. */
2572 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2573 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2574 0, 0);
2575 break;
2577 case 11:
2578 /* Path where the binary is found. */
2579 if (!INTUSE(__libc_enable_secure)
2580 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2581 GLRO(dl_origin_path) = &envline[12];
2582 break;
2584 case 12:
2585 /* The library search path. */
2586 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2588 library_path = &envline[13];
2589 break;
2592 /* Where to place the profiling data file. */
2593 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2595 debug_output = &envline[13];
2596 break;
2599 if (!INTUSE(__libc_enable_secure)
2600 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2601 GLRO(dl_dynamic_weak) = 1;
2602 break;
2604 case 13:
2605 /* We might have some extra environment variable with length 13
2606 to handle. */
2607 #ifdef EXTRA_LD_ENVVARS_13
2608 EXTRA_LD_ENVVARS_13
2609 #endif
2610 if (!INTUSE(__libc_enable_secure)
2611 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2613 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2614 break;
2617 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2618 GLRO(dl_pointer_guard) = envline[14] != '0';
2619 break;
2621 case 14:
2622 /* Where to place the profiling data file. */
2623 if (!INTUSE(__libc_enable_secure)
2624 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2625 && envline[15] != '\0')
2626 GLRO(dl_profile_output) = &envline[15];
2627 break;
2629 case 16:
2630 /* The mode of the dynamic linker can be set. */
2631 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2633 mode = trace;
2634 GLRO(dl_verbose) = 1;
2635 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2636 GLRO(dl_trace_prelink) = &envline[17];
2638 break;
2640 case 20:
2641 /* The mode of the dynamic linker can be set. */
2642 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2643 mode = trace;
2644 break;
2646 /* We might have some extra environment variable to handle. This
2647 is tricky due to the pre-processing of the length of the name
2648 in the switch statement here. The code here assumes that added
2649 environment variables have a different length. */
2650 #ifdef EXTRA_LD_ENVVARS
2651 EXTRA_LD_ENVVARS
2652 #endif
2656 /* The caller wants this information. */
2657 *modep = mode;
2659 /* Extra security for SUID binaries. Remove all dangerous environment
2660 variables. */
2661 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2663 static const char unsecure_envvars[] =
2664 #ifdef EXTRA_UNSECURE_ENVVARS
2665 EXTRA_UNSECURE_ENVVARS
2666 #endif
2667 UNSECURE_ENVVARS;
2668 const char *nextp;
2670 nextp = unsecure_envvars;
2673 unsetenv (nextp);
2674 /* We could use rawmemchr but this need not be fast. */
2675 nextp = (char *) (strchr) (nextp, '\0') + 1;
2677 while (*nextp != '\0');
2679 if (__access ("/etc/suid-debug", F_OK) != 0)
2681 unsetenv ("MALLOC_CHECK_");
2682 GLRO(dl_debug_mask) = 0;
2685 if (mode != normal)
2686 _exit (5);
2688 /* If we have to run the dynamic linker in debugging mode and the
2689 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2690 messages to this file. */
2691 else if (any_debug && debug_output != NULL)
2693 #ifdef O_NOFOLLOW
2694 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2695 #else
2696 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2697 #endif
2698 size_t name_len = strlen (debug_output);
2699 char buf[name_len + 12];
2700 char *startp;
2702 buf[name_len + 11] = '\0';
2703 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2704 *--startp = '.';
2705 startp = memcpy (startp - name_len, debug_output, name_len);
2707 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2708 if (GLRO(dl_debug_fd) == -1)
2709 /* We use standard output if opening the file failed. */
2710 GLRO(dl_debug_fd) = STDOUT_FILENO;
2715 /* Print the various times we collected. */
2716 static void
2717 __attribute ((noinline))
2718 print_statistics (hp_timing_t *rtld_total_timep)
2720 #ifndef HP_TIMING_NONAVAIL
2721 char buf[200];
2722 char *cp;
2723 char *wp;
2725 /* Total time rtld used. */
2726 if (HP_TIMING_AVAIL)
2728 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2729 _dl_debug_printf ("\nruntime linker statistics:\n"
2730 " total startup time in dynamic loader: %s\n", buf);
2732 /* Print relocation statistics. */
2733 char pbuf[30];
2734 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2735 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2736 pbuf + sizeof (pbuf), 10, 0);
2737 wp = pbuf;
2738 switch (pbuf + sizeof (pbuf) - cp)
2740 case 3:
2741 *wp++ = *cp++;
2742 case 2:
2743 *wp++ = *cp++;
2744 case 1:
2745 *wp++ = '.';
2746 *wp++ = *cp++;
2748 *wp = '\0';
2749 _dl_debug_printf ("\
2750 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2752 #endif
2754 unsigned long int num_relative_relocations = 0;
2755 for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
2757 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2758 continue;
2760 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2762 for (unsigned int i = 0; i < scope->r_nlist; i++)
2764 struct link_map *l = scope->r_list [i];
2766 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2767 num_relative_relocations
2768 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2769 #ifndef ELF_MACHINE_REL_RELATIVE
2770 /* Relative relocations are processed on these architectures if
2771 library is loaded to different address than p_vaddr or
2772 if not prelinked. */
2773 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2774 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2775 #else
2776 /* On e.g. IA-64 or Alpha, relative relocations are processed
2777 only if library is loaded to different address than p_vaddr. */
2778 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2779 #endif
2780 num_relative_relocations
2781 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2785 _dl_debug_printf (" number of relocations: %lu\n"
2786 " number of relocations from cache: %lu\n"
2787 " number of relative relocations: %lu\n",
2788 GL(dl_num_relocations),
2789 GL(dl_num_cache_relocations),
2790 num_relative_relocations);
2792 #ifndef HP_TIMING_NONAVAIL
2793 /* Time spend while loading the object and the dependencies. */
2794 if (HP_TIMING_AVAIL)
2796 char pbuf[30];
2797 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2798 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2799 pbuf + sizeof (pbuf), 10, 0);
2800 wp = pbuf;
2801 switch (pbuf + sizeof (pbuf) - cp)
2803 case 3:
2804 *wp++ = *cp++;
2805 case 2:
2806 *wp++ = *cp++;
2807 case 1:
2808 *wp++ = '.';
2809 *wp++ = *cp++;
2811 *wp = '\0';
2812 _dl_debug_printf ("\
2813 time needed to load objects: %s (%s%%)\n",
2814 buf, pbuf);
2816 #endif