* elf/cache.c: Use <> rather than "" #includes.
[glibc.git] / elf / rtld.c
blob71bcf0ab7149218cc5331f63267b05da22b64c49
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2002, 2003, 2004, 2005 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 #if defined PI_STATIC_AND_HIDDEN && defined HAVE_HIDDEN \
211 && defined HAVE_VISIBILITY_ATTRIBUTE
212 # define DONT_USE_BOOTSTRAP_MAP 1
213 #endif
215 #ifdef DONT_USE_BOOTSTRAP_MAP
216 static ElfW(Addr) _dl_start_final (void *arg);
217 #else
218 struct dl_start_final_info
220 struct link_map l;
221 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
222 hp_timing_t start_time;
223 #endif
225 static ElfW(Addr) _dl_start_final (void *arg,
226 struct dl_start_final_info *info);
227 #endif
229 /* These defined magically in the linker script. */
230 extern char _begin[] attribute_hidden;
231 extern char _etext[] attribute_hidden;
232 extern char _end[] attribute_hidden;
235 #ifdef RTLD_START
236 RTLD_START
237 #else
238 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
239 #endif
241 #ifndef VALIDX
242 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
243 + DT_EXTRANUM + DT_VALTAGIDX (tag))
244 #endif
245 #ifndef ADDRIDX
246 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
247 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
248 #endif
250 /* This is the second half of _dl_start (below). It can be inlined safely
251 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
252 references. When the tools don't permit us to avoid using a GOT entry
253 for _dl_rtld_global (no attribute_hidden support), we must make sure
254 this function is not inlined (see below). */
256 #ifdef DONT_USE_BOOTSTRAP_MAP
257 static inline ElfW(Addr) __attribute__ ((always_inline))
258 _dl_start_final (void *arg)
259 #else
260 static ElfW(Addr) __attribute__ ((noinline))
261 _dl_start_final (void *arg, struct dl_start_final_info *info)
262 #endif
264 ElfW(Addr) start_addr;
266 if (HP_TIMING_AVAIL)
268 /* If it hasn't happen yet record the startup time. */
269 if (! HP_TIMING_INLINE)
270 HP_TIMING_NOW (start_time);
271 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
272 else
273 start_time = info->start_time;
274 #endif
276 /* Initialize the timing functions. */
277 HP_TIMING_DIFF_INIT ();
280 /* Transfer data about ourselves to the permanent link_map structure. */
281 #ifndef DONT_USE_BOOTSTRAP_MAP
282 GL(dl_rtld_map).l_addr = info->l.l_addr;
283 GL(dl_rtld_map).l_ld = info->l.l_ld;
284 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
285 sizeof GL(dl_rtld_map).l_info);
286 GL(dl_rtld_map).l_mach = info->l.l_mach;
287 GL(dl_rtld_map).l_relocated = 1;
288 #endif
289 _dl_setup_hash (&GL(dl_rtld_map));
290 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
291 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
292 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
293 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
294 /* Copy the TLS related data if necessary. */
295 #if USE_TLS && !defined DONT_USE_BOOTSTRAP_MAP
296 # if USE___THREAD
297 assert (info->l.l_tls_modid != 0);
298 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
299 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
300 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
301 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
302 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
303 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
304 GL(dl_rtld_map).l_tls_modid = 1;
305 # else
306 assert (info->l.l_tls_modid == 0);
307 # if NO_TLS_OFFSET != 0
308 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
309 # endif
310 # endif
312 #endif
314 #if HP_TIMING_AVAIL
315 HP_TIMING_NOW (GL(dl_cpuclock_offset));
316 #endif
318 /* Initialize the stack end variable. */
319 __libc_stack_end = __builtin_frame_address (0);
321 /* Call the OS-dependent function to set up life so we can do things like
322 file access. It will call `dl_main' (below) to do all the real work
323 of the dynamic linker, and then unwind our frame and run the user
324 entry point on the same stack we entered on. */
325 start_addr = _dl_sysdep_start (arg, &dl_main);
327 #ifndef HP_TIMING_NONAVAIL
328 hp_timing_t rtld_total_time;
329 if (HP_TIMING_AVAIL)
331 hp_timing_t end_time;
333 /* Get the current time. */
334 HP_TIMING_NOW (end_time);
336 /* Compute the difference. */
337 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
339 #endif
341 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
343 #ifndef HP_TIMING_NONAVAIL
344 print_statistics (&rtld_total_time);
345 #else
346 print_statistics (NULL);
347 #endif
350 return start_addr;
353 static ElfW(Addr) __attribute_used__ internal_function
354 _dl_start (void *arg)
356 #ifdef DONT_USE_BOOTSTRAP_MAP
357 # define bootstrap_map GL(dl_rtld_map)
358 #else
359 struct dl_start_final_info info;
360 # define bootstrap_map info.l
361 #endif
363 /* This #define produces dynamic linking inline functions for
364 bootstrap relocation instead of general-purpose relocation. */
365 #define RTLD_BOOTSTRAP
366 #define RESOLVE_MAP(sym, version, flags) \
367 ((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map)
368 #include "dynamic-link.h"
370 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
371 #ifdef DONT_USE_BOOTSTRAP_MAP
372 HP_TIMING_NOW (start_time);
373 #else
374 HP_TIMING_NOW (info.start_time);
375 #endif
377 /* Partly clean the `bootstrap_map' structure up. Don't use
378 `memset' since it might not be built in or inlined and we cannot
379 make function calls at this point. Use '__builtin_memset' if we
380 know it is available. We do not have to clear the memory if we
381 do not have to use the temporary bootstrap_map. Global variables
382 are initialized to zero by default. */
383 #ifndef DONT_USE_BOOTSTRAP_MAP
384 # ifdef HAVE_BUILTIN_MEMSET
385 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
386 # else
387 for (size_t cnt = 0;
388 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
389 ++cnt)
390 bootstrap_map.l_info[cnt] = 0;
391 # endif
392 #endif
394 /* Figure out the run-time load address of the dynamic linker itself. */
395 bootstrap_map.l_addr = elf_machine_load_address ();
397 /* Read our own dynamic section and fill in the info array. */
398 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
399 elf_get_dynamic_info (&bootstrap_map, NULL);
401 #if defined USE_TLS && NO_TLS_OFFSET != 0
402 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
403 #endif
405 /* Get the dynamic linker's own program header. First we need the ELF
406 file header. The `_begin' symbol created by the linker script points
407 to it. When we have something like GOTOFF relocs, we can use a plain
408 reference to find the runtime address. Without that, we have to rely
409 on the `l_addr' value, which is not the value we want when prelinked. */
410 #if USE___THREAD
411 dtv_t initdtv[3];
412 ElfW(Ehdr) *ehdr
413 # ifdef DONT_USE_BOOTSTRAP_MAP
414 = (ElfW(Ehdr) *) &_begin;
415 # else
416 # error This will not work with prelink.
417 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
418 # endif
419 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
420 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
421 while (cnt-- > 0)
422 if (phdr[cnt].p_type == PT_TLS)
424 void *tlsblock;
425 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
426 char *p;
428 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
429 bootstrap_map.l_tls_align = phdr[cnt].p_align;
430 if (phdr[cnt].p_align == 0)
431 bootstrap_map.l_tls_firstbyte_offset = 0;
432 else
433 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
434 & (phdr[cnt].p_align - 1));
435 assert (bootstrap_map.l_tls_blocksize != 0);
436 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
437 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
438 + phdr[cnt].p_vaddr);
440 /* We can now allocate the initial TLS block. This can happen
441 on the stack. We'll get the final memory later when we
442 know all about the various objects loaded at startup
443 time. */
444 # if TLS_TCB_AT_TP
445 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
446 TLS_INIT_TCB_ALIGN)
447 + TLS_INIT_TCB_SIZE
448 + max_align);
449 # elif TLS_DTV_AT_TP
450 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
451 bootstrap_map.l_tls_align)
452 + bootstrap_map.l_tls_blocksize
453 + max_align);
454 # else
455 /* In case a model with a different layout for the TCB and DTV
456 is defined add another #elif here and in the following #ifs. */
457 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
458 # endif
459 /* Align the TLS block. */
460 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
461 & ~(max_align - 1));
463 /* Initialize the dtv. [0] is the length, [1] the generation
464 counter. */
465 initdtv[0].counter = 1;
466 initdtv[1].counter = 0;
468 /* Initialize the TLS block. */
469 # if TLS_TCB_AT_TP
470 initdtv[2].pointer = tlsblock;
471 # elif TLS_DTV_AT_TP
472 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
473 bootstrap_map.l_tls_align);
474 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
475 # else
476 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
477 # endif
478 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
479 bootstrap_map.l_tls_initimage_size);
480 # ifdef HAVE_BUILTIN_MEMSET
481 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
482 - bootstrap_map.l_tls_initimage_size));
483 # else
485 size_t remaining = (bootstrap_map.l_tls_blocksize
486 - bootstrap_map.l_tls_initimage_size);
487 while (remaining-- > 0)
488 *p++ = '\0';
490 # endif
492 /* Install the pointer to the dtv. */
494 /* Initialize the thread pointer. */
495 # if TLS_TCB_AT_TP
496 bootstrap_map.l_tls_offset
497 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
499 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
500 initdtv);
502 const char *lossage = TLS_INIT_TP ((char *) tlsblock
503 + bootstrap_map.l_tls_offset, 0);
504 # elif TLS_DTV_AT_TP
505 INSTALL_DTV (tlsblock, initdtv);
506 const char *lossage = TLS_INIT_TP (tlsblock, 0);
507 # else
508 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
509 # endif
510 if (__builtin_expect (lossage != NULL, 0))
511 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
512 lossage);
514 /* So far this is module number one. */
515 bootstrap_map.l_tls_modid = 1;
517 /* There can only be one PT_TLS entry. */
518 break;
520 #endif /* USE___THREAD */
522 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
523 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
524 #endif
526 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
528 /* Relocate ourselves so we can do normal function calls and
529 data access using the global offset table. */
531 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
533 bootstrap_map.l_relocated = 1;
535 /* Please note that we don't allow profiling of this object and
536 therefore need not test whether we have to allocate the array
537 for the relocation results (as done in dl-reloc.c). */
539 /* Now life is sane; we can call functions and access global data.
540 Set up to use the operating system facilities, and find out from
541 the operating system's program loader where to find the program
542 header table in core. Put the rest of _dl_start into a separate
543 function, that way the compiler cannot put accesses to the GOT
544 before ELF_DYNAMIC_RELOCATE. */
546 #ifdef DONT_USE_BOOTSTRAP_MAP
547 ElfW(Addr) entry = _dl_start_final (arg);
548 #else
549 ElfW(Addr) entry = _dl_start_final (arg, &info);
550 #endif
552 #ifndef ELF_MACHINE_START_ADDRESS
553 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
554 #endif
556 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
562 /* Now life is peachy; we can do all normal operations.
563 On to the real work. */
565 /* Some helper functions. */
567 /* Arguments to relocate_doit. */
568 struct relocate_args
570 struct link_map *l;
571 int lazy;
574 struct map_args
576 /* Argument to map_doit. */
577 char *str;
578 struct link_map *loader;
579 int is_preloaded;
580 int mode;
581 /* Return value of map_doit. */
582 struct link_map *map;
585 struct dlmopen_args
587 const char *fname;
588 struct link_map *map;
591 struct lookup_args
593 const char *name;
594 struct link_map *map;
595 void *result;
598 /* Arguments to version_check_doit. */
599 struct version_check_args
601 int doexit;
602 int dotrace;
605 static void
606 relocate_doit (void *a)
608 struct relocate_args *args = (struct relocate_args *) a;
610 _dl_relocate_object (args->l, args->l->l_scope, args->lazy, 0);
613 static void
614 map_doit (void *a)
616 struct map_args *args = (struct map_args *) a;
617 args->map = _dl_map_object (args->loader, args->str,
618 args->is_preloaded, lt_library, 0, args->mode,
619 LM_ID_BASE);
622 static void
623 dlmopen_doit (void *a)
625 struct dlmopen_args *args = (struct dlmopen_args *) a;
626 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
627 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
628 __environ);
631 static void
632 lookup_doit (void *a)
634 struct lookup_args *args = (struct lookup_args *) a;
635 const ElfW(Sym) *ref = NULL;
636 args->result = NULL;
637 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
638 args->map->l_local_scope, NULL, 0,
639 DL_LOOKUP_RETURN_NEWEST, NULL);
640 if (ref != NULL)
641 args->result = DL_SYMBOL_ADDRESS (l, ref);
644 static void
645 version_check_doit (void *a)
647 struct version_check_args *args = (struct version_check_args *) a;
648 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
649 args->dotrace) && args->doexit)
650 /* We cannot start the application. Abort now. */
651 _exit (1);
655 static inline struct link_map *
656 find_needed (const char *name)
658 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
659 unsigned int n = scope->r_nlist;
661 while (n-- > 0)
662 if (_dl_name_match_p (name, scope->r_list[n]))
663 return scope->r_list[n];
665 /* Should never happen. */
666 return NULL;
669 static int
670 match_version (const char *string, struct link_map *map)
672 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
673 ElfW(Verdef) *def;
675 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
676 if (map->l_info[VERDEFTAG] == NULL)
677 /* The file has no symbol versioning. */
678 return 0;
680 def = (ElfW(Verdef) *) ((char *) map->l_addr
681 + map->l_info[VERDEFTAG]->d_un.d_ptr);
682 while (1)
684 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
686 /* Compare the version strings. */
687 if (strcmp (string, strtab + aux->vda_name) == 0)
688 /* Bingo! */
689 return 1;
691 /* If no more definitions we failed to find what we want. */
692 if (def->vd_next == 0)
693 break;
695 /* Next definition. */
696 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
699 return 0;
702 #ifdef USE_TLS
703 static bool tls_init_tp_called;
705 static void *
706 init_tls (void)
708 /* Number of elements in the static TLS block. */
709 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
711 /* Do not do this twice. The audit interface might have required
712 the DTV interfaces to be set up early. */
713 if (GL(dl_initial_dtv) != NULL)
714 return NULL;
716 /* Allocate the array which contains the information about the
717 dtv slots. We allocate a few entries more than needed to
718 avoid the need for reallocation. */
719 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
721 /* Allocate. */
722 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
723 calloc (sizeof (struct dtv_slotinfo_list)
724 + nelem * sizeof (struct dtv_slotinfo), 1);
725 /* No need to check the return value. If memory allocation failed
726 the program would have been terminated. */
728 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
729 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
730 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
732 /* Fill in the information from the loaded modules. No namespace
733 but the base one can be filled at this time. */
734 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
735 int i = 0;
736 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
737 l = l->l_next)
738 if (l->l_tls_blocksize != 0)
740 /* This is a module with TLS data. Store the map reference.
741 The generation counter is zero. */
742 slotinfo[i].map = l;
743 /* slotinfo[i].gen = 0; */
744 ++i;
746 assert (i == GL(dl_tls_max_dtv_idx));
748 /* Compute the TLS offsets for the various blocks. */
749 _dl_determine_tlsoffset ();
751 /* Construct the static TLS block and the dtv for the initial
752 thread. For some platforms this will include allocating memory
753 for the thread descriptor. The memory for the TLS block will
754 never be freed. It should be allocated accordingly. The dtv
755 array can be changed if dynamic loading requires it. */
756 void *tcbp = _dl_allocate_tls_storage ();
757 if (tcbp == NULL)
758 _dl_fatal_printf ("\
759 cannot allocate TLS data structures for initial thread");
761 /* Store for detection of the special case by __tls_get_addr
762 so it knows not to pass this dtv to the normal realloc. */
763 GL(dl_initial_dtv) = GET_DTV (tcbp);
765 /* And finally install it for the main thread. If ld.so itself uses
766 TLS we know the thread pointer was initialized earlier. */
767 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
768 if (__builtin_expect (lossage != NULL, 0))
769 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
770 tls_init_tp_called = true;
772 return tcbp;
774 #endif
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 /* The library search path. */
837 static const char *library_path attribute_relro;
838 /* The list preloaded objects. */
839 static const char *preloadlist attribute_relro;
840 /* Nonzero if information about versions has to be printed. */
841 static int version_info attribute_relro;
843 static void
844 dl_main (const ElfW(Phdr) *phdr,
845 ElfW(Word) phnum,
846 ElfW(Addr) *user_entry)
848 const ElfW(Phdr) *ph;
849 enum mode mode;
850 struct link_map *main_map;
851 size_t file_size;
852 char *file;
853 bool has_interp = false;
854 unsigned int i;
855 bool prelinked = false;
856 bool rtld_is_main = false;
857 #ifndef HP_TIMING_NONAVAIL
858 hp_timing_t start;
859 hp_timing_t stop;
860 hp_timing_t diff;
861 #endif
862 #ifdef USE_TLS
863 void *tcbp = NULL;
864 #endif
866 #ifdef _LIBC_REENTRANT
867 /* Explicit initialization since the reloc would just be more work. */
868 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
869 #endif
871 #ifdef USE_TLS
872 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
873 #endif
875 #if defined SHARED && defined _LIBC_REENTRANT \
876 && defined __rtld_lock_default_lock_recursive
877 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
878 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
879 #endif
881 /* The explicit initialization here is cheaper than processing the reloc
882 in the _rtld_local definition's initializer. */
883 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
885 /* Process the environment variable which control the behaviour. */
886 process_envvars (&mode);
888 #ifndef HAVE_INLINED_SYSCALLS
889 /* Set up a flag which tells we are just starting. */
890 INTUSE(_dl_starting_up) = 1;
891 #endif
893 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
895 /* Ho ho. We are not the program interpreter! We are the program
896 itself! This means someone ran ld.so as a command. Well, that
897 might be convenient to do sometimes. We support it by
898 interpreting the args like this:
900 ld.so PROGRAM ARGS...
902 The first argument is the name of a file containing an ELF
903 executable we will load and run with the following arguments.
904 To simplify life here, PROGRAM is searched for using the
905 normal rules for shared objects, rather than $PATH or anything
906 like that. We just load it and use its entry point; we don't
907 pay attention to its PT_INTERP command (we are the interpreter
908 ourselves). This is an easy way to test a new ld.so before
909 installing it. */
910 rtld_is_main = true;
912 /* Note the place where the dynamic linker actually came from. */
913 GL(dl_rtld_map).l_name = rtld_progname;
915 while (_dl_argc > 1)
916 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
918 mode = list;
919 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
921 ++_dl_skip_args;
922 --_dl_argc;
923 ++INTUSE(_dl_argv);
925 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
927 mode = verify;
929 ++_dl_skip_args;
930 --_dl_argc;
931 ++INTUSE(_dl_argv);
933 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
934 && _dl_argc > 2)
936 library_path = INTUSE(_dl_argv)[2];
938 _dl_skip_args += 2;
939 _dl_argc -= 2;
940 INTUSE(_dl_argv) += 2;
942 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
943 && _dl_argc > 2)
945 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
947 _dl_skip_args += 2;
948 _dl_argc -= 2;
949 INTUSE(_dl_argv) += 2;
951 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
953 process_dl_audit (INTUSE(_dl_argv)[2]);
955 _dl_skip_args += 2;
956 _dl_argc -= 2;
957 INTUSE(_dl_argv) += 2;
959 else
960 break;
962 /* If we have no further argument the program was called incorrectly.
963 Grant the user some education. */
964 if (_dl_argc < 2)
965 _dl_fatal_printf ("\
966 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
967 You have invoked `ld.so', the helper program for shared library executables.\n\
968 This program usually lives in the file `/lib/ld.so', and special directives\n\
969 in executable files using ELF shared libraries tell the system's program\n\
970 loader to load the helper program from this file. This helper program loads\n\
971 the shared libraries needed by the program executable, prepares the program\n\
972 to run, and runs it. You may invoke this helper program directly from the\n\
973 command line to load and run an ELF executable file; this is like executing\n\
974 that file itself, but always uses this helper program from the file you\n\
975 specified, instead of the helper program file specified in the executable\n\
976 file you run. This is mostly of use for maintainers to test new versions\n\
977 of this helper program; chances are you did not intend to run this program.\n\
979 --list list all dependencies and how they are resolved\n\
980 --verify verify that given object really is a dynamically linked\n\
981 object we can handle\n\
982 --library-path PATH use given PATH instead of content of the environment\n\
983 variable LD_LIBRARY_PATH\n\
984 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
985 in LIST\n");
987 ++_dl_skip_args;
988 --_dl_argc;
989 ++INTUSE(_dl_argv);
991 /* The initialization of _dl_stack_flags done below assumes the
992 executable's PT_GNU_STACK may have been honored by the kernel, and
993 so a PT_GNU_STACK with PF_X set means the stack started out with
994 execute permission. However, this is not really true if the
995 dynamic linker is the executable the kernel loaded. For this
996 case, we must reinitialize _dl_stack_flags to match the dynamic
997 linker itself. If the dynamic linker was built with a
998 PT_GNU_STACK, then the kernel may have loaded us with a
999 nonexecutable stack that we will have to make executable when we
1000 load the program below unless it has a PT_GNU_STACK indicating
1001 nonexecutable stack is ok. */
1003 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1004 if (ph->p_type == PT_GNU_STACK)
1006 GL(dl_stack_flags) = ph->p_flags;
1007 break;
1010 if (__builtin_expect (mode, normal) == verify)
1012 const char *objname;
1013 const char *err_str = NULL;
1014 struct map_args args;
1015 bool malloced;
1017 args.str = rtld_progname;
1018 args.loader = NULL;
1019 args.is_preloaded = 0;
1020 args.mode = __RTLD_OPENEXEC;
1021 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1022 &args);
1023 if (__builtin_expect (err_str != NULL, 0))
1024 /* We don't free the returned string, the programs stops
1025 anyway. */
1026 _exit (EXIT_FAILURE);
1028 else
1030 HP_TIMING_NOW (start);
1031 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1032 __RTLD_OPENEXEC, LM_ID_BASE);
1033 HP_TIMING_NOW (stop);
1035 HP_TIMING_DIFF (load_time, start, stop);
1038 /* Now the map for the main executable is available. */
1039 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1041 phdr = main_map->l_phdr;
1042 phnum = main_map->l_phnum;
1043 /* We overwrite here a pointer to a malloc()ed string. But since
1044 the malloc() implementation used at this point is the dummy
1045 implementations which has no real free() function it does not
1046 makes sense to free the old string first. */
1047 main_map->l_name = (char *) "";
1048 *user_entry = main_map->l_entry;
1050 else
1052 /* Create a link_map for the executable itself.
1053 This will be what dlopen on "" returns. */
1054 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1055 __RTLD_OPENEXEC, LM_ID_BASE);
1056 assert (main_map != NULL);
1057 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1058 main_map->l_phdr = phdr;
1059 main_map->l_phnum = phnum;
1060 main_map->l_entry = *user_entry;
1062 /* At this point we are in a bit of trouble. We would have to
1063 fill in the values for l_dev and l_ino. But in general we
1064 do not know where the file is. We also do not handle AT_EXECFD
1065 even if it would be passed up.
1067 We leave the values here defined to 0. This is normally no
1068 problem as the program code itself is normally no shared
1069 object and therefore cannot be loaded dynamically. Nothing
1070 prevent the use of dynamic binaries and in these situations
1071 we might get problems. We might not be able to find out
1072 whether the object is already loaded. But since there is no
1073 easy way out and because the dynamic binary must also not
1074 have an SONAME we ignore this program for now. If it becomes
1075 a problem we can force people using SONAMEs. */
1077 /* We delay initializing the path structure until we got the dynamic
1078 information for the program. */
1081 main_map->l_map_end = 0;
1082 main_map->l_text_end = 0;
1083 /* Perhaps the executable has no PT_LOAD header entries at all. */
1084 main_map->l_map_start = ~0;
1085 /* And it was opened directly. */
1086 ++main_map->l_direct_opencount;
1088 /* Scan the program header table for the dynamic section. */
1089 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1090 switch (ph->p_type)
1092 case PT_PHDR:
1093 /* Find out the load address. */
1094 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1095 break;
1096 case PT_DYNAMIC:
1097 /* This tells us where to find the dynamic section,
1098 which tells us everything we need to do. */
1099 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1100 break;
1101 case PT_INTERP:
1102 /* This "interpreter segment" was used by the program loader to
1103 find the program interpreter, which is this program itself, the
1104 dynamic linker. We note what name finds us, so that a future
1105 dlopen call or DT_NEEDED entry, for something that wants to link
1106 against the dynamic linker as a shared library, will know that
1107 the shared object is already loaded. */
1108 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1109 + ph->p_vaddr);
1110 /* _dl_rtld_libname.next = NULL; Already zero. */
1111 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1113 /* Ordinarilly, we would get additional names for the loader from
1114 our DT_SONAME. This can't happen if we were actually linked as
1115 a static executable (detect this case when we have no DYNAMIC).
1116 If so, assume the filename component of the interpreter path to
1117 be our SONAME, and add it to our name list. */
1118 if (GL(dl_rtld_map).l_ld == NULL)
1120 const char *p = NULL;
1121 const char *cp = _dl_rtld_libname.name;
1123 /* Find the filename part of the path. */
1124 while (*cp != '\0')
1125 if (*cp++ == '/')
1126 p = cp;
1128 if (p != NULL)
1130 _dl_rtld_libname2.name = p;
1131 /* _dl_rtld_libname2.next = NULL; Already zero. */
1132 _dl_rtld_libname.next = &_dl_rtld_libname2;
1136 has_interp = true;
1137 break;
1138 case PT_LOAD:
1140 ElfW(Addr) mapstart;
1141 ElfW(Addr) allocend;
1143 /* Remember where the main program starts in memory. */
1144 mapstart = (main_map->l_addr + (ph->p_vaddr & ~(ph->p_align - 1)));
1145 if (main_map->l_map_start > mapstart)
1146 main_map->l_map_start = mapstart;
1148 /* Also where it ends. */
1149 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1150 if (main_map->l_map_end < allocend)
1151 main_map->l_map_end = allocend;
1152 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1153 main_map->l_text_end = allocend;
1155 break;
1157 case PT_TLS:
1158 #ifdef USE_TLS
1159 if (ph->p_memsz > 0)
1161 /* Note that in the case the dynamic linker we duplicate work
1162 here since we read the PT_TLS entry already in
1163 _dl_start_final. But the result is repeatable so do not
1164 check for this special but unimportant case. */
1165 main_map->l_tls_blocksize = ph->p_memsz;
1166 main_map->l_tls_align = ph->p_align;
1167 if (ph->p_align == 0)
1168 main_map->l_tls_firstbyte_offset = 0;
1169 else
1170 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1171 & (ph->p_align - 1));
1172 main_map->l_tls_initimage_size = ph->p_filesz;
1173 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1175 /* This image gets the ID one. */
1176 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1178 #else
1179 _dl_fatal_printf ("\
1180 ld.so does not support TLS, but program uses it!\n");
1181 #endif
1182 break;
1184 case PT_GNU_STACK:
1185 GL(dl_stack_flags) = ph->p_flags;
1186 break;
1188 case PT_GNU_RELRO:
1189 main_map->l_relro_addr = ph->p_vaddr;
1190 main_map->l_relro_size = ph->p_memsz;
1191 break;
1193 #ifdef USE_TLS
1194 /* Adjust the address of the TLS initialization image in case
1195 the executable is actually an ET_DYN object. */
1196 if (main_map->l_tls_initimage != NULL)
1197 main_map->l_tls_initimage
1198 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1199 #endif
1200 if (! main_map->l_map_end)
1201 main_map->l_map_end = ~0;
1202 if (! main_map->l_text_end)
1203 main_map->l_text_end = ~0;
1204 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1206 /* We were invoked directly, so the program might not have a
1207 PT_INTERP. */
1208 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1209 /* _dl_rtld_libname.next = NULL; Already zero. */
1210 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1212 else
1213 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1215 /* If the current libname is different from the SONAME, add the
1216 latter as well. */
1217 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1218 && strcmp (GL(dl_rtld_map).l_libname->name,
1219 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1220 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1222 static struct libname_list newname;
1223 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1224 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1225 newname.next = NULL;
1226 newname.dont_free = 1;
1228 assert (GL(dl_rtld_map).l_libname->next == NULL);
1229 GL(dl_rtld_map).l_libname->next = &newname;
1231 /* The ld.so must be relocated since otherwise loading audit modules
1232 will fail since they reuse the very same ld.so. */
1233 assert (GL(dl_rtld_map).l_relocated);
1235 if (! rtld_is_main)
1237 /* Extract the contents of the dynamic section for easy access. */
1238 elf_get_dynamic_info (main_map, NULL);
1239 /* Set up our cache of pointers into the hash table. */
1240 _dl_setup_hash (main_map);
1243 if (__builtin_expect (mode, normal) == verify)
1245 /* We were called just to verify that this is a dynamic
1246 executable using us as the program interpreter. Exit with an
1247 error if we were not able to load the binary or no interpreter
1248 is specified (i.e., this is no dynamically linked binary. */
1249 if (main_map->l_ld == NULL)
1250 _exit (1);
1252 /* We allow here some platform specific code. */
1253 #ifdef DISTINGUISH_LIB_VERSIONS
1254 DISTINGUISH_LIB_VERSIONS;
1255 #endif
1256 _exit (has_interp ? 0 : 2);
1259 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1260 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1261 /* Set up the data structures for the system-supplied DSO early,
1262 so they can influence _dl_init_paths. */
1263 if (GLRO(dl_sysinfo_dso) != NULL)
1265 /* Do an abridged version of the work _dl_map_object_from_fd would do
1266 to map in the object. It's already mapped and prelinked (and
1267 better be, since it's read-only and so we couldn't relocate it).
1268 We just want our data structures to describe it as if we had just
1269 mapped and relocated it normally. */
1270 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1271 0, LM_ID_BASE);
1272 if (__builtin_expect (l != NULL, 1))
1274 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1276 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1277 + GLRO(dl_sysinfo_dso)->e_phoff);
1278 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1279 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1281 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1282 if (ph->p_type == PT_DYNAMIC)
1284 l->l_ld = (void *) ph->p_vaddr;
1285 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1287 else if (ph->p_type == PT_LOAD)
1289 if (! l->l_addr)
1290 l->l_addr = ph->p_vaddr;
1291 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1292 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1293 if ((ph->p_flags & PF_X)
1294 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1295 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1297 else
1298 /* There must be no TLS segment. */
1299 assert (ph->p_type != PT_TLS);
1301 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1302 l->l_addr = l->l_map_start - l->l_addr;
1303 l->l_map_end += l->l_addr;
1304 l->l_text_end += l->l_addr;
1305 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1306 elf_get_dynamic_info (l, dyn_temp);
1307 _dl_setup_hash (l);
1308 l->l_relocated = 1;
1310 /* Now that we have the info handy, use the DSO image's soname
1311 so this object can be looked up by name. Note that we do not
1312 set l_name here. That field gives the file name of the DSO,
1313 and this DSO is not associated with any file. */
1314 if (l->l_info[DT_SONAME] != NULL)
1316 /* Work around a kernel problem. The kernel cannot handle
1317 addresses in the vsyscall DSO pages in writev() calls. */
1318 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1319 + l->l_info[DT_SONAME]->d_un.d_val);
1320 size_t len = strlen (dsoname);
1321 char *copy = malloc (len);
1322 if (copy == NULL)
1323 _dl_fatal_printf ("out of memory\n");
1324 l->l_libname->name = memcpy (copy, dsoname, len);
1327 /* Rearrange the list so this DSO appears after rtld_map. */
1328 assert (l->l_next == NULL);
1329 assert (l->l_prev == main_map);
1330 GL(dl_rtld_map).l_next = l;
1331 l->l_prev = &GL(dl_rtld_map);
1332 first_preload = &l->l_next;
1334 /* We have a prelinked DSO preloaded by the system. */
1335 GLRO(dl_sysinfo_map) = l;
1336 # ifdef NEED_DL_SYSINFO
1337 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1338 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1339 # endif
1342 #endif
1344 #ifdef DL_SYSDEP_OSCHECK
1345 DL_SYSDEP_OSCHECK (dl_fatal);
1346 #endif
1348 /* Initialize the data structures for the search paths for shared
1349 objects. */
1350 _dl_init_paths (library_path);
1352 /* Initialize _r_debug. */
1353 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1354 LM_ID_BASE);
1355 r->r_state = RT_CONSISTENT;
1357 /* Put the link_map for ourselves on the chain so it can be found by
1358 name. Note that at this point the global chain of link maps contains
1359 exactly one element, which is pointed to by dl_loaded. */
1360 if (! GL(dl_rtld_map).l_name)
1361 /* If not invoked directly, the dynamic linker shared object file was
1362 found by the PT_INTERP name. */
1363 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1364 GL(dl_rtld_map).l_type = lt_library;
1365 main_map->l_next = &GL(dl_rtld_map);
1366 GL(dl_rtld_map).l_prev = main_map;
1367 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1368 ++GL(dl_load_adds);
1370 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1371 to not using bias for non-prelinked PIEs and libraries
1372 and using it for executables or prelinked PIEs or libraries. */
1373 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1374 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1376 /* Set up the program header information for the dynamic linker
1377 itself. It is needed in the dl_iterate_phdr() callbacks. */
1378 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1379 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1380 + rtld_ehdr->e_phoff);
1381 GL(dl_rtld_map).l_phdr = rtld_phdr;
1382 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1385 /* PT_GNU_RELRO is usually the last phdr. */
1386 size_t cnt = rtld_ehdr->e_phnum;
1387 while (cnt-- > 0)
1388 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1390 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1391 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1392 break;
1395 #ifdef USE_TLS
1396 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1397 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1398 /* Assign a module ID. Do this before loading any audit modules. */
1399 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1400 #endif
1402 /* If we have auditing DSOs to load, do it now. */
1403 if (__builtin_expect (audit_list != NULL, 0))
1405 /* Iterate over all entries in the list. The order is important. */
1406 struct audit_ifaces *last_audit = NULL;
1407 struct audit_list *al = audit_list->next;
1410 #ifdef USE_TLS
1411 int tls_idx = GL(dl_tls_max_dtv_idx);
1413 /* Now it is time to determine the layout of the static TLS
1414 block and allocate it for the initial thread. Note that we
1415 always allocate the static block, we never defer it even if
1416 no DF_STATIC_TLS bit is set. The reason is that we know
1417 glibc will use the static model. */
1419 /* Since we start using the auditing DSOs right away we need to
1420 initialize the data structures now. */
1421 tcbp = init_tls ();
1422 #endif
1423 struct dlmopen_args dlmargs;
1424 dlmargs.fname = al->name;
1425 dlmargs.map = NULL;
1427 const char *objname;
1428 const char *err_str = NULL;
1429 bool malloced;
1430 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1431 &dlmargs);
1432 if (__builtin_expect (err_str != NULL, 0))
1434 not_loaded:
1435 _dl_error_printf ("\
1436 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1437 al->name, err_str);
1438 if (malloced)
1439 free ((char *) err_str);
1441 else
1443 struct lookup_args largs;
1444 largs.name = "la_version";
1445 largs.map = dlmargs.map;
1447 /* Check whether the interface version matches. */
1448 (void) _dl_catch_error (&objname, &err_str, &malloced,
1449 lookup_doit, &largs);
1451 unsigned int (*laversion) (unsigned int);
1452 unsigned int lav;
1453 if (err_str == NULL
1454 && (laversion = largs.result) != NULL
1455 && (lav = laversion (LAV_CURRENT)) > 0
1456 && lav <= LAV_CURRENT)
1458 /* Allocate structure for the callback function pointers.
1459 This call can never fail. */
1460 union
1462 struct audit_ifaces ifaces;
1463 #define naudit_ifaces 8
1464 void (*fptr[naudit_ifaces]) (void);
1465 } *newp = malloc (sizeof (*newp));
1467 /* Names of the auditing interfaces. All in one
1468 long string. */
1469 static const char audit_iface_names[] =
1470 "la_activity\0"
1471 "la_objsearch\0"
1472 "la_objopen\0"
1473 "la_preinit\0"
1474 #if __ELF_NATIVE_CLASS == 32
1475 "la_symbind32\0"
1476 #elif __ELF_NATIVE_CLASS == 64
1477 "la_symbind64\0"
1478 #else
1479 # error "__ELF_NATIVE_CLASS must be defined"
1480 #endif
1481 #define STRING(s) __STRING (s)
1482 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1483 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1484 "la_objclose\0";
1485 unsigned int cnt = 0;
1486 const char *cp = audit_iface_names;
1489 largs.name = cp;
1490 (void) _dl_catch_error (&objname, &err_str, &malloced,
1491 lookup_doit, &largs);
1493 /* Store the pointer. */
1494 if (err_str == NULL && largs.result != NULL)
1496 newp->fptr[cnt] = largs.result;
1498 /* The dynamic linker link map is statically
1499 allocated, initialize the data now. */
1500 GL(dl_rtld_map).l_audit[cnt].cookie
1501 = (intptr_t) &GL(dl_rtld_map);
1503 else
1504 newp->fptr[cnt] = NULL;
1505 ++cnt;
1507 cp = (char *) rawmemchr (cp, '\0') + 1;
1509 while (*cp != '\0');
1510 assert (cnt == naudit_ifaces);
1512 /* Now append the new auditing interface to the list. */
1513 newp->ifaces.next = NULL;
1514 if (last_audit == NULL)
1515 last_audit = GLRO(dl_audit) = &newp->ifaces;
1516 else
1517 last_audit = last_audit->next = &newp->ifaces;
1518 ++GLRO(dl_naudit);
1520 /* Mark the DSO as being used for auditing. */
1521 dlmargs.map->l_auditing = 1;
1523 else
1525 /* We cannot use the DSO, it does not have the
1526 appropriate interfaces or it expects something
1527 more recent. */
1528 #ifndef NDEBUG
1529 Lmid_t ns = dlmargs.map->l_ns;
1530 #endif
1531 _dl_close (dlmargs.map);
1533 /* Make sure the namespace has been cleared entirely. */
1534 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1535 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1537 #ifdef USE_TLS
1538 GL(dl_tls_max_dtv_idx) = tls_idx;
1539 #endif
1540 goto not_loaded;
1544 al = al->next;
1546 while (al != audit_list->next);
1548 /* If we have any auditing modules, announce that we already
1549 have two objects loaded. */
1550 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1552 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1554 for (unsigned int outer = 0; outer < 2; ++outer)
1556 struct audit_ifaces *afct = GLRO(dl_audit);
1557 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1559 if (afct->objopen != NULL)
1561 ls[outer]->l_audit[cnt].bindflags
1562 = afct->objopen (ls[outer], LM_ID_BASE,
1563 &ls[outer]->l_audit[cnt].cookie);
1565 ls[outer]->l_audit_any_plt
1566 |= ls[outer]->l_audit[cnt].bindflags != 0;
1569 afct = afct->next;
1575 /* Set up debugging before the debugger is notified for the first time. */
1576 #ifdef ELF_MACHINE_DEBUG_SETUP
1577 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1578 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1579 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1580 #else
1581 if (main_map->l_info[DT_DEBUG] != NULL)
1582 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1583 with the run-time address of the r_debug structure */
1584 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1586 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1587 case you run gdb on the dynamic linker directly. */
1588 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1589 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1590 #endif
1592 /* We start adding objects. */
1593 r->r_state = RT_ADD;
1594 _dl_debug_state ();
1596 /* Auditing checkpoint: we are ready to signal that the initial map
1597 is being constructed. */
1598 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1600 struct audit_ifaces *afct = GLRO(dl_audit);
1601 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1603 if (afct->activity != NULL)
1604 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1606 afct = afct->next;
1610 /* We have two ways to specify objects to preload: via environment
1611 variable and via the file /etc/ld.so.preload. The latter can also
1612 be used when security is enabled. */
1613 assert (*first_preload == NULL);
1614 struct link_map **preloads = NULL;
1615 unsigned int npreloads = 0;
1617 if (__builtin_expect (preloadlist != NULL, 0))
1619 /* The LD_PRELOAD environment variable gives list of libraries
1620 separated by white space or colons that are loaded before the
1621 executable's dependencies and prepended to the global scope
1622 list. If the binary is running setuid all elements
1623 containing a '/' are ignored since it is insecure. */
1624 char *list = strdupa (preloadlist);
1625 char *p;
1627 HP_TIMING_NOW (start);
1629 /* Prevent optimizing strsep. Speed is not important here. */
1630 while ((p = (strsep) (&list, " :")) != NULL)
1631 if (p[0] != '\0'
1632 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1633 || strchr (p, '/') == NULL))
1634 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1636 HP_TIMING_NOW (stop);
1637 HP_TIMING_DIFF (diff, start, stop);
1638 HP_TIMING_ACCUM_NT (load_time, diff);
1641 /* There usually is no ld.so.preload file, it should only be used
1642 for emergencies and testing. So the open call etc should usually
1643 fail. Using access() on a non-existing file is faster than using
1644 open(). So we do this first. If it succeeds we do almost twice
1645 the work but this does not matter, since it is not for production
1646 use. */
1647 static const char preload_file[] = "/etc/ld.so.preload";
1648 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1650 /* Read the contents of the file. */
1651 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1652 PROT_READ | PROT_WRITE);
1653 if (__builtin_expect (file != MAP_FAILED, 0))
1655 /* Parse the file. It contains names of libraries to be loaded,
1656 separated by white spaces or `:'. It may also contain
1657 comments introduced by `#'. */
1658 char *problem;
1659 char *runp;
1660 size_t rest;
1662 /* Eliminate comments. */
1663 runp = file;
1664 rest = file_size;
1665 while (rest > 0)
1667 char *comment = memchr (runp, '#', rest);
1668 if (comment == NULL)
1669 break;
1671 rest -= comment - runp;
1673 *comment = ' ';
1674 while (--rest > 0 && *++comment != '\n');
1677 /* We have one problematic case: if we have a name at the end of
1678 the file without a trailing terminating characters, we cannot
1679 place the \0. Handle the case separately. */
1680 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1681 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1683 problem = &file[file_size];
1684 while (problem > file && problem[-1] != ' '
1685 && problem[-1] != '\t'
1686 && problem[-1] != '\n' && problem[-1] != ':')
1687 --problem;
1689 if (problem > file)
1690 problem[-1] = '\0';
1692 else
1694 problem = NULL;
1695 file[file_size - 1] = '\0';
1698 HP_TIMING_NOW (start);
1700 if (file != problem)
1702 char *p;
1703 runp = file;
1704 while ((p = strsep (&runp, ": \t\n")) != NULL)
1705 if (p[0] != '\0')
1706 npreloads += do_preload (p, main_map, preload_file);
1709 if (problem != NULL)
1711 char *p = strndupa (problem, file_size - (problem - file));
1713 npreloads += do_preload (p, main_map, preload_file);
1716 HP_TIMING_NOW (stop);
1717 HP_TIMING_DIFF (diff, start, stop);
1718 HP_TIMING_ACCUM_NT (load_time, diff);
1720 /* We don't need the file anymore. */
1721 __munmap (file, file_size);
1725 if (__builtin_expect (*first_preload != NULL, 0))
1727 /* Set up PRELOADS with a vector of the preloaded libraries. */
1728 struct link_map *l = *first_preload;
1729 preloads = __alloca (npreloads * sizeof preloads[0]);
1730 i = 0;
1733 preloads[i++] = l;
1734 l = l->l_next;
1735 } while (l);
1736 assert (i == npreloads);
1739 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1740 specified some libraries to load, these are inserted before the actual
1741 dependencies in the executable's searchlist for symbol resolution. */
1742 HP_TIMING_NOW (start);
1743 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1744 HP_TIMING_NOW (stop);
1745 HP_TIMING_DIFF (diff, start, stop);
1746 HP_TIMING_ACCUM_NT (load_time, diff);
1748 /* Mark all objects as being in the global scope. */
1749 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1750 main_map->l_searchlist.r_list[--i]->l_global = 1;
1752 #ifndef MAP_ANON
1753 /* We are done mapping things, so close the zero-fill descriptor. */
1754 __close (_dl_zerofd);
1755 _dl_zerofd = -1;
1756 #endif
1758 /* Remove _dl_rtld_map from the chain. */
1759 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1760 if (GL(dl_rtld_map).l_next != NULL)
1761 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1763 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1764 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1765 break;
1767 bool rtld_multiple_ref = false;
1768 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1770 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1771 put it back in the list of visible objects. We insert it into the
1772 chain in symbol search order because gdb uses the chain's order as
1773 its symbol search order. */
1774 rtld_multiple_ref = true;
1776 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1777 if (__builtin_expect (mode, normal) == normal)
1779 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1780 ? main_map->l_searchlist.r_list[i + 1]
1781 : NULL);
1782 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1783 if (GLRO(dl_sysinfo_map) != NULL
1784 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1785 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1786 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1787 #endif
1789 else
1790 /* In trace mode there might be an invisible object (which we
1791 could not find) after the previous one in the search list.
1792 In this case it doesn't matter much where we put the
1793 interpreter object, so we just initialize the list pointer so
1794 that the assertion below holds. */
1795 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1797 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1798 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1799 if (GL(dl_rtld_map).l_next != NULL)
1801 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1802 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1806 /* Now let us see whether all libraries are available in the
1807 versions we need. */
1809 struct version_check_args args;
1810 args.doexit = mode == normal;
1811 args.dotrace = mode == trace;
1812 _dl_receive_error (print_missing_version, version_check_doit, &args);
1815 #ifdef USE_TLS
1816 /* We do not initialize any of the TLS functionality unless any of the
1817 initial modules uses TLS. This makes dynamic loading of modules with
1818 TLS impossible, but to support it requires either eagerly doing setup
1819 now or lazily doing it later. Doing it now makes us incompatible with
1820 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1821 used. Trying to do it lazily is too hairy to try when there could be
1822 multiple threads (from a non-TLS-using libpthread). */
1823 bool was_tls_init_tp_called = tls_init_tp_called;
1824 if (tcbp == NULL)
1825 tcbp = init_tls ();
1826 #endif
1828 /* Set up the stack checker's canary. */
1829 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
1830 #ifdef THREAD_SET_STACK_GUARD
1831 THREAD_SET_STACK_GUARD (stack_chk_guard);
1832 #else
1833 __stack_chk_guard = stack_chk_guard;
1834 #endif
1836 /* Set up the pointer guard as well, if necessary. */
1837 if (GLRO(dl_pointer_guard))
1839 // XXX If it is cheap, we should use a separate value.
1840 uintptr_t pointer_chk_guard = stack_chk_guard;
1841 #ifndef HP_TIMING_NONAVAIL
1842 hp_timing_t now;
1843 HP_TIMING_NOW (now);
1844 pointer_chk_guard ^= now;
1845 #endif
1846 #ifdef THREAD_SET_POINTER_GUARD
1847 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
1848 #endif
1849 __pointer_chk_guard_local = pointer_chk_guard;
1852 if (__builtin_expect (mode, normal) != normal)
1854 /* We were run just to list the shared libraries. It is
1855 important that we do this before real relocation, because the
1856 functions we call below for output may no longer work properly
1857 after relocation. */
1858 struct link_map *l;
1860 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1862 struct r_scope_elem *scope = &main_map->l_searchlist;
1864 for (i = 0; i < scope->r_nlist; i++)
1866 l = scope->r_list [i];
1867 if (l->l_faked)
1869 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1870 continue;
1872 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1873 GLRO(dl_trace_prelink_map) = l;
1874 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1875 l->l_libname->name[0] ? l->l_libname->name
1876 : rtld_progname ?: "<main program>",
1877 l->l_name[0] ? l->l_name
1878 : rtld_progname ?: "<main program>",
1879 (int) sizeof l->l_map_start * 2,
1880 (size_t) l->l_map_start,
1881 (int) sizeof l->l_addr * 2,
1882 (size_t) l->l_addr);
1883 #ifdef USE_TLS
1884 if (l->l_tls_modid)
1885 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1886 (int) sizeof l->l_tls_offset * 2,
1887 (size_t) l->l_tls_offset);
1888 else
1889 #endif
1890 _dl_printf ("\n");
1893 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1895 /* Look through the dependencies of the main executable
1896 and determine which of them is not actually
1897 required. */
1898 struct link_map *l = main_map;
1900 /* Relocate the main executable. */
1901 struct relocate_args args = { .l = l, .lazy = GLRO(dl_lazy) };
1902 _dl_receive_error (print_unresolved, relocate_doit, &args);
1904 /* This loop depends on the dependencies of the executable to
1905 correspond in number and order to the DT_NEEDED entries. */
1906 ElfW(Dyn) *dyn = main_map->l_ld;
1907 bool first = true;
1908 while (dyn->d_tag != DT_NULL)
1910 if (dyn->d_tag == DT_NEEDED)
1912 l = l->l_next;
1914 if (!l->l_used)
1916 if (first)
1918 _dl_printf ("Unused direct dependencies:\n");
1919 first = false;
1922 _dl_printf ("\t%s\n", l->l_name);
1926 ++dyn;
1929 _exit (first != true);
1931 else if (! main_map->l_info[DT_NEEDED])
1932 _dl_printf ("\tstatically linked\n");
1933 else
1935 for (l = main_map->l_next; l; l = l->l_next)
1936 if (l->l_faked)
1937 /* The library was not found. */
1938 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1939 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1940 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1941 (int) sizeof l->l_map_start * 2,
1942 (size_t) l->l_map_start);
1943 else
1944 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1945 l->l_name, (int) sizeof l->l_map_start * 2,
1946 (size_t) l->l_map_start);
1949 if (__builtin_expect (mode, trace) != trace)
1950 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1952 const ElfW(Sym) *ref = NULL;
1953 ElfW(Addr) loadbase;
1954 lookup_t result;
1956 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1957 &ref, main_map->l_scope, NULL,
1958 ELF_RTYPE_CLASS_PLT,
1959 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1961 loadbase = LOOKUP_VALUE_ADDRESS (result);
1963 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1964 INTUSE(_dl_argv)[i],
1965 (int) sizeof ref->st_value * 2,
1966 (size_t) ref->st_value,
1967 (int) sizeof loadbase * 2, (size_t) loadbase);
1969 else
1971 /* If LD_WARN is set, warn about undefined symbols. */
1972 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1974 /* We have to do symbol dependency testing. */
1975 struct relocate_args args;
1976 struct link_map *l;
1978 args.lazy = GLRO(dl_lazy);
1980 l = main_map;
1981 while (l->l_next != NULL)
1982 l = l->l_next;
1985 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1987 args.l = l;
1988 _dl_receive_error (print_unresolved, relocate_doit,
1989 &args);
1991 l = l->l_prev;
1993 while (l != NULL);
1995 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1996 && rtld_multiple_ref)
1998 /* Mark the link map as not yet relocated again. */
1999 GL(dl_rtld_map).l_relocated = 0;
2000 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope,
2001 0, 0);
2004 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2005 if (version_info)
2007 /* Print more information. This means here, print information
2008 about the versions needed. */
2009 int first = 1;
2010 struct link_map *map;
2012 for (map = main_map; map != NULL; map = map->l_next)
2014 const char *strtab;
2015 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2016 ElfW(Verneed) *ent;
2018 if (dyn == NULL)
2019 continue;
2021 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2022 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2024 if (first)
2026 _dl_printf ("\n\tVersion information:\n");
2027 first = 0;
2030 _dl_printf ("\t%s:\n",
2031 map->l_name[0] ? map->l_name : rtld_progname);
2033 while (1)
2035 ElfW(Vernaux) *aux;
2036 struct link_map *needed;
2038 needed = find_needed (strtab + ent->vn_file);
2039 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2041 while (1)
2043 const char *fname = NULL;
2045 if (needed != NULL
2046 && match_version (strtab + aux->vna_name,
2047 needed))
2048 fname = needed->l_name;
2050 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2051 strtab + ent->vn_file,
2052 strtab + aux->vna_name,
2053 aux->vna_flags & VER_FLG_WEAK
2054 ? "[WEAK] " : "",
2055 fname ?: "not found");
2057 if (aux->vna_next == 0)
2058 /* No more symbols. */
2059 break;
2061 /* Next symbol. */
2062 aux = (ElfW(Vernaux) *) ((char *) aux
2063 + aux->vna_next);
2066 if (ent->vn_next == 0)
2067 /* No more dependencies. */
2068 break;
2070 /* Next dependency. */
2071 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2077 _exit (0);
2080 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2081 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0))
2083 ElfW(Lib) *liblist, *liblistend;
2084 struct link_map **r_list, **r_listend, *l;
2085 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2087 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2088 liblist = (ElfW(Lib) *)
2089 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2090 liblistend = (ElfW(Lib) *)
2091 ((char *) liblist +
2092 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2093 r_list = main_map->l_searchlist.r_list;
2094 r_listend = r_list + main_map->l_searchlist.r_nlist;
2096 for (; r_list < r_listend && liblist < liblistend; r_list++)
2098 l = *r_list;
2100 if (l == main_map)
2101 continue;
2103 /* If the library is not mapped where it should, fail. */
2104 if (l->l_addr)
2105 break;
2107 /* Next, check if checksum matches. */
2108 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2109 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2110 != liblist->l_checksum)
2111 break;
2113 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2114 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2115 != liblist->l_time_stamp)
2116 break;
2118 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2119 break;
2121 ++liblist;
2125 if (r_list == r_listend && liblist == liblistend)
2126 prelinked = true;
2128 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2129 _dl_debug_printf ("\nprelink checking: %s\n",
2130 prelinked ? "ok" : "failed");
2134 /* Now set up the variable which helps the assembler startup code. */
2135 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2136 GL(dl_ns)[LM_ID_BASE]._ns_global_scope[0] = &main_map->l_searchlist;
2138 /* Save the information about the original global scope list since
2139 we need it in the memory handling later. */
2140 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2142 if (prelinked)
2144 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2146 ElfW(Rela) *conflict, *conflictend;
2147 #ifndef HP_TIMING_NONAVAIL
2148 hp_timing_t start;
2149 hp_timing_t stop;
2150 #endif
2152 HP_TIMING_NOW (start);
2153 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2154 conflict = (ElfW(Rela) *)
2155 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2156 conflictend = (ElfW(Rela) *)
2157 ((char *) conflict
2158 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2159 _dl_resolve_conflicts (main_map, conflict, conflictend);
2160 HP_TIMING_NOW (stop);
2161 HP_TIMING_DIFF (relocate_time, start, stop);
2165 /* Mark all the objects so we know they have been already relocated. */
2166 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2168 l->l_relocated = 1;
2169 if (l->l_relro_size)
2170 _dl_protect_relro (l);
2172 #ifdef USE_TLS
2173 /* Add object to slot information data if necessasy. */
2174 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2175 _dl_add_to_slotinfo (l);
2176 #endif
2179 _dl_sysdep_start_cleanup ();
2181 else
2183 /* Now we have all the objects loaded. Relocate them all except for
2184 the dynamic linker itself. We do this in reverse order so that copy
2185 relocs of earlier objects overwrite the data written by later
2186 objects. We do not re-relocate the dynamic linker itself in this
2187 loop because that could result in the GOT entries for functions we
2188 call being changed, and that would break us. It is safe to relocate
2189 the dynamic linker out of order because it has no copy relocs (we
2190 know that because it is self-contained). */
2192 int consider_profiling = GLRO(dl_profile) != NULL;
2193 #ifndef HP_TIMING_NONAVAIL
2194 hp_timing_t start;
2195 hp_timing_t stop;
2196 hp_timing_t add;
2197 #endif
2199 /* If we are profiling we also must do lazy reloaction. */
2200 GLRO(dl_lazy) |= consider_profiling;
2202 struct link_map *l = main_map;
2203 while (l->l_next)
2204 l = l->l_next;
2206 HP_TIMING_NOW (start);
2209 /* While we are at it, help the memory handling a bit. We have to
2210 mark some data structures as allocated with the fake malloc()
2211 implementation in ld.so. */
2212 struct libname_list *lnp = l->l_libname->next;
2214 while (__builtin_expect (lnp != NULL, 0))
2216 lnp->dont_free = 1;
2217 lnp = lnp->next;
2220 if (l != &GL(dl_rtld_map))
2221 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy),
2222 consider_profiling);
2224 #ifdef USE_TLS
2225 /* Add object to slot information data if necessasy. */
2226 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2227 _dl_add_to_slotinfo (l);
2228 #endif
2230 l = l->l_prev;
2232 while (l);
2233 HP_TIMING_NOW (stop);
2235 HP_TIMING_DIFF (relocate_time, start, stop);
2237 /* Do any necessary cleanups for the startup OS interface code.
2238 We do these now so that no calls are made after rtld re-relocation
2239 which might be resolved to different functions than we expect.
2240 We cannot do this before relocating the other objects because
2241 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2242 _dl_sysdep_start_cleanup ();
2244 /* Now enable profiling if needed. Like the previous call,
2245 this has to go here because the calls it makes should use the
2246 rtld versions of the functions (particularly calloc()), but it
2247 needs to have _dl_profile_map set up by the relocator. */
2248 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2249 /* We must prepare the profiling. */
2250 _dl_start_profile ();
2252 if (rtld_multiple_ref)
2254 /* There was an explicit ref to the dynamic linker as a shared lib.
2255 Re-relocate ourselves with user-controlled symbol definitions. */
2256 HP_TIMING_NOW (start);
2257 /* Mark the link map as not yet relocated again. */
2258 GL(dl_rtld_map).l_relocated = 0;
2259 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2260 HP_TIMING_NOW (stop);
2261 HP_TIMING_DIFF (add, start, stop);
2262 HP_TIMING_ACCUM_NT (relocate_time, add);
2266 #ifndef NONTLS_INIT_TP
2267 # define NONTLS_INIT_TP do { } while (0)
2268 #endif
2270 #ifdef USE_TLS
2271 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2272 ++GL(dl_tls_generation);
2274 /* Now that we have completed relocation, the initializer data
2275 for the TLS blocks has its final values and we can copy them
2276 into the main thread's TLS area, which we allocated above. */
2277 _dl_allocate_tls_init (tcbp);
2279 /* And finally install it for the main thread. If ld.so itself uses
2280 TLS we know the thread pointer was initialized earlier. */
2281 if (! tls_init_tp_called)
2283 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2284 if (__builtin_expect (lossage != NULL, 0))
2285 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2286 lossage);
2288 #else
2289 NONTLS_INIT_TP;
2290 #endif
2292 #ifdef SHARED
2293 /* Auditing checkpoint: we have added all objects. */
2294 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2296 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2297 /* Do not call the functions for any auditing object. */
2298 if (head->l_auditing == 0)
2300 struct audit_ifaces *afct = GLRO(dl_audit);
2301 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2303 if (afct->activity != NULL)
2304 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2306 afct = afct->next;
2310 #endif
2312 /* Notify the debugger all new objects are now ready to go. We must re-get
2313 the address since by now the variable might be in another object. */
2314 r = _dl_debug_initialize (0, LM_ID_BASE);
2315 r->r_state = RT_CONSISTENT;
2316 _dl_debug_state ();
2318 #ifndef MAP_COPY
2319 /* We must munmap() the cache file. */
2320 _dl_unload_cache ();
2321 #endif
2323 /* Once we return, _dl_sysdep_start will invoke
2324 the DT_INIT functions and then *USER_ENTRY. */
2327 /* This is a little helper function for resolving symbols while
2328 tracing the binary. */
2329 static void
2330 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2331 const char *errstring)
2333 if (objname[0] == '\0')
2334 objname = rtld_progname ?: "<main program>";
2335 _dl_error_printf ("%s (%s)\n", errstring, objname);
2338 /* This is a little helper function for resolving symbols while
2339 tracing the binary. */
2340 static void
2341 print_missing_version (int errcode __attribute__ ((unused)),
2342 const char *objname, const char *errstring)
2344 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2345 objname, errstring);
2348 /* Nonzero if any of the debugging options is enabled. */
2349 static int any_debug attribute_relro;
2351 /* Process the string given as the parameter which explains which debugging
2352 options are enabled. */
2353 static void
2354 process_dl_debug (const char *dl_debug)
2356 /* When adding new entries make sure that the maximal length of a name
2357 is correctly handled in the LD_DEBUG_HELP code below. */
2358 static const struct
2360 unsigned char len;
2361 const char name[10];
2362 const char helptext[41];
2363 unsigned short int mask;
2364 } debopts[] =
2366 #define LEN_AND_STR(str) sizeof (str) - 1, str
2367 { LEN_AND_STR ("libs"), "display library search paths",
2368 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2369 { LEN_AND_STR ("reloc"), "display relocation processing",
2370 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2371 { LEN_AND_STR ("files"), "display progress for input file",
2372 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2373 { LEN_AND_STR ("symbols"), "display symbol table processing",
2374 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2375 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2376 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2377 { LEN_AND_STR ("versions"), "display version dependencies",
2378 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2379 { LEN_AND_STR ("all"), "all previous options combined",
2380 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2381 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2382 { LEN_AND_STR ("statistics"), "display relocation statistics",
2383 DL_DEBUG_STATISTICS },
2384 { LEN_AND_STR ("unused"), "determined unused DSOs",
2385 DL_DEBUG_UNUSED },
2386 { LEN_AND_STR ("help"), "display this help message and exit",
2387 DL_DEBUG_HELP },
2389 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2391 /* Skip separating white spaces and commas. */
2392 while (*dl_debug != '\0')
2394 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2396 size_t cnt;
2397 size_t len = 1;
2399 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2400 && dl_debug[len] != ',' && dl_debug[len] != ':')
2401 ++len;
2403 for (cnt = 0; cnt < ndebopts; ++cnt)
2404 if (debopts[cnt].len == len
2405 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2407 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2408 any_debug = 1;
2409 break;
2412 if (cnt == ndebopts)
2414 /* Display a warning and skip everything until next
2415 separator. */
2416 char *copy = strndupa (dl_debug, len);
2417 _dl_error_printf ("\
2418 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2421 dl_debug += len;
2422 continue;
2425 ++dl_debug;
2428 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2430 size_t cnt;
2432 _dl_printf ("\
2433 Valid options for the LD_DEBUG environment variable are:\n\n");
2435 for (cnt = 0; cnt < ndebopts; ++cnt)
2436 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2437 " " + debopts[cnt].len - 3,
2438 debopts[cnt].helptext);
2440 _dl_printf ("\n\
2441 To direct the debugging output into a file instead of standard output\n\
2442 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2443 _exit (0);
2447 static void
2448 process_dl_audit (char *str)
2450 /* The parameter is a colon separated list of DSO names. */
2451 char *p;
2453 while ((p = (strsep) (&str, ":")) != NULL)
2454 if (p[0] != '\0'
2455 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2456 || strchr (p, '/') == NULL))
2458 /* This is using the local malloc, not the system malloc. The
2459 memory can never be freed. */
2460 struct audit_list *newp = malloc (sizeof (*newp));
2461 newp->name = p;
2463 if (audit_list == NULL)
2464 audit_list = newp->next = newp;
2465 else
2467 newp->next = audit_list->next;
2468 audit_list = audit_list->next = newp;
2473 /* Process all environments variables the dynamic linker must recognize.
2474 Since all of them start with `LD_' we are a bit smarter while finding
2475 all the entries. */
2476 extern char **_environ attribute_hidden;
2479 static void
2480 process_envvars (enum mode *modep)
2482 char **runp = _environ;
2483 char *envline;
2484 enum mode mode = normal;
2485 char *debug_output = NULL;
2487 /* This is the default place for profiling data file. */
2488 GLRO(dl_profile_output)
2489 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2491 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2493 size_t len = 0;
2495 while (envline[len] != '\0' && envline[len] != '=')
2496 ++len;
2498 if (envline[len] != '=')
2499 /* This is a "LD_" variable at the end of the string without
2500 a '=' character. Ignore it since otherwise we will access
2501 invalid memory below. */
2502 continue;
2504 switch (len)
2506 case 4:
2507 /* Warning level, verbose or not. */
2508 if (memcmp (envline, "WARN", 4) == 0)
2509 GLRO(dl_verbose) = envline[5] != '\0';
2510 break;
2512 case 5:
2513 /* Debugging of the dynamic linker? */
2514 if (memcmp (envline, "DEBUG", 5) == 0)
2516 process_dl_debug (&envline[6]);
2517 break;
2519 if (memcmp (envline, "AUDIT", 5) == 0)
2520 process_dl_audit (&envline[6]);
2521 break;
2523 case 7:
2524 /* Print information about versions. */
2525 if (memcmp (envline, "VERBOSE", 7) == 0)
2527 version_info = envline[8] != '\0';
2528 break;
2531 /* List of objects to be preloaded. */
2532 if (memcmp (envline, "PRELOAD", 7) == 0)
2534 preloadlist = &envline[8];
2535 break;
2538 /* Which shared object shall be profiled. */
2539 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2540 GLRO(dl_profile) = &envline[8];
2541 break;
2543 case 8:
2544 /* Do we bind early? */
2545 if (memcmp (envline, "BIND_NOW", 8) == 0)
2547 GLRO(dl_lazy) = envline[9] == '\0';
2548 break;
2550 if (memcmp (envline, "BIND_NOT", 8) == 0)
2551 GLRO(dl_bind_not) = envline[9] != '\0';
2552 break;
2554 case 9:
2555 /* Test whether we want to see the content of the auxiliary
2556 array passed up from the kernel. */
2557 if (!INTUSE(__libc_enable_secure)
2558 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2559 _dl_show_auxv ();
2560 break;
2562 case 10:
2563 /* Mask for the important hardware capabilities. */
2564 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2565 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2566 0, 0);
2567 break;
2569 case 11:
2570 /* Path where the binary is found. */
2571 if (!INTUSE(__libc_enable_secure)
2572 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2573 GLRO(dl_origin_path) = &envline[12];
2574 break;
2576 case 12:
2577 /* The library search path. */
2578 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2580 library_path = &envline[13];
2581 break;
2584 /* Where to place the profiling data file. */
2585 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2587 debug_output = &envline[13];
2588 break;
2591 if (!INTUSE(__libc_enable_secure)
2592 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2593 GLRO(dl_dynamic_weak) = 1;
2594 break;
2596 case 13:
2597 /* We might have some extra environment variable with length 13
2598 to handle. */
2599 #ifdef EXTRA_LD_ENVVARS_13
2600 EXTRA_LD_ENVVARS_13
2601 #endif
2602 if (!INTUSE(__libc_enable_secure)
2603 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2605 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2606 break;
2609 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2610 GLRO(dl_pointer_guard) = envline[14] == '0';
2611 break;
2613 case 14:
2614 /* Where to place the profiling data file. */
2615 if (!INTUSE(__libc_enable_secure)
2616 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2617 && envline[15] != '\0')
2618 GLRO(dl_profile_output) = &envline[15];
2619 break;
2621 case 16:
2622 /* The mode of the dynamic linker can be set. */
2623 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2625 mode = trace;
2626 GLRO(dl_verbose) = 1;
2627 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2628 GLRO(dl_trace_prelink) = &envline[17];
2630 break;
2632 case 20:
2633 /* The mode of the dynamic linker can be set. */
2634 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2635 mode = trace;
2636 break;
2638 /* We might have some extra environment variable to handle. This
2639 is tricky due to the pre-processing of the length of the name
2640 in the switch statement here. The code here assumes that added
2641 environment variables have a different length. */
2642 #ifdef EXTRA_LD_ENVVARS
2643 EXTRA_LD_ENVVARS
2644 #endif
2648 /* The caller wants this information. */
2649 *modep = mode;
2651 /* Extra security for SUID binaries. Remove all dangerous environment
2652 variables. */
2653 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2655 static const char unsecure_envvars[] =
2656 #ifdef EXTRA_UNSECURE_ENVVARS
2657 EXTRA_UNSECURE_ENVVARS
2658 #endif
2659 UNSECURE_ENVVARS;
2660 const char *nextp;
2662 nextp = unsecure_envvars;
2665 unsetenv (nextp);
2666 /* We could use rawmemchr but this need not be fast. */
2667 nextp = (char *) (strchr) (nextp, '\0') + 1;
2669 while (*nextp != '\0');
2671 if (__access ("/etc/suid-debug", F_OK) != 0)
2673 unsetenv ("MALLOC_CHECK_");
2674 GLRO(dl_debug_mask) = 0;
2677 if (mode != normal)
2678 _exit (5);
2680 /* If we have to run the dynamic linker in debugging mode and the
2681 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2682 messages to this file. */
2683 else if (any_debug && debug_output != NULL)
2685 #ifdef O_NOFOLLOW
2686 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2687 #else
2688 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2689 #endif
2690 size_t name_len = strlen (debug_output);
2691 char buf[name_len + 12];
2692 char *startp;
2694 buf[name_len + 11] = '\0';
2695 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2696 *--startp = '.';
2697 startp = memcpy (startp - name_len, debug_output, name_len);
2699 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2700 if (GLRO(dl_debug_fd) == -1)
2701 /* We use standard output if opening the file failed. */
2702 GLRO(dl_debug_fd) = STDOUT_FILENO;
2707 /* Print the various times we collected. */
2708 static void
2709 __attribute ((noinline))
2710 print_statistics (hp_timing_t *rtld_total_timep)
2712 #ifndef HP_TIMING_NONAVAIL
2713 char buf[200];
2714 char *cp;
2715 char *wp;
2717 /* Total time rtld used. */
2718 if (HP_TIMING_AVAIL)
2720 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2721 _dl_debug_printf ("\nruntime linker statistics:\n"
2722 " total startup time in dynamic loader: %s\n", buf);
2724 /* Print relocation statistics. */
2725 char pbuf[30];
2726 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2727 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2728 pbuf + sizeof (pbuf), 10, 0);
2729 wp = pbuf;
2730 switch (pbuf + sizeof (pbuf) - cp)
2732 case 3:
2733 *wp++ = *cp++;
2734 case 2:
2735 *wp++ = *cp++;
2736 case 1:
2737 *wp++ = '.';
2738 *wp++ = *cp++;
2740 *wp = '\0';
2741 _dl_debug_printf ("\
2742 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2744 #endif
2746 unsigned long int num_relative_relocations = 0;
2747 for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
2749 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2750 continue;
2752 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2754 for (unsigned int i = 0; i < scope->r_nlist; i++)
2756 struct link_map *l = scope->r_list [i];
2758 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2759 num_relative_relocations
2760 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2761 #ifndef ELF_MACHINE_REL_RELATIVE
2762 /* Relative relocations are processed on these architectures if
2763 library is loaded to different address than p_vaddr or
2764 if not prelinked. */
2765 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2766 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2767 #else
2768 /* On e.g. IA-64 or Alpha, relative relocations are processed
2769 only if library is loaded to different address than p_vaddr. */
2770 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2771 #endif
2772 num_relative_relocations
2773 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2777 _dl_debug_printf (" number of relocations: %lu\n"
2778 " number of relocations from cache: %lu\n"
2779 " number of relative relocations: %lu\n",
2780 GL(dl_num_relocations),
2781 GL(dl_num_cache_relocations),
2782 num_relative_relocations);
2784 #ifndef HP_TIMING_NONAVAIL
2785 /* Time spend while loading the object and the dependencies. */
2786 if (HP_TIMING_AVAIL)
2788 char pbuf[30];
2789 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2790 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2791 pbuf + sizeof (pbuf), 10, 0);
2792 wp = pbuf;
2793 switch (pbuf + sizeof (pbuf) - cp)
2795 case 3:
2796 *wp++ = *cp++;
2797 case 2:
2798 *wp++ = *cp++;
2799 case 1:
2800 *wp++ = '.';
2801 *wp++ = *cp++;
2803 *wp = '\0';
2804 _dl_debug_printf ("\
2805 time needed to load objects: %s (%s%%)\n",
2806 buf, pbuf);
2808 #endif