2.13-1
[glibc.git] / elf / rtld.c
blob5e0db1202f8b7e429282ca70f70e061b0a14dc83
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h>
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
43 #include <stackinfo.h>
45 #include <assert.h>
47 /* Avoid PLT use for our local calls at startup. */
48 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
50 /* GCC has mental blocks about _exit. */
51 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
52 #define _exit exit_internal
54 /* Helper function to handle errors while resolving symbols. */
55 static void print_unresolved (int errcode, const char *objname,
56 const char *errsting);
58 /* Helper function to handle errors when a version is missing. */
59 static void print_missing_version (int errcode, const char *objname,
60 const char *errsting);
62 /* Print the various times we collected. */
63 static void print_statistics (hp_timing_t *total_timep);
65 /* Add audit objects. */
66 static void process_dl_audit (char *str);
68 /* This is a list of all the modes the dynamic loader can be in. */
69 enum mode { normal, list, verify, trace };
71 /* Process all environments variables the dynamic linker must recognize.
72 Since all of them start with `LD_' we are a bit smarter while finding
73 all the entries. */
74 static void process_envvars (enum mode *modep);
76 #ifdef DL_ARGV_NOT_RELRO
77 int _dl_argc attribute_hidden;
78 char **_dl_argv = NULL;
79 /* Nonzero if we were run directly. */
80 unsigned int _dl_skip_args attribute_hidden;
81 #else
82 int _dl_argc attribute_relro attribute_hidden;
83 char **_dl_argv attribute_relro = NULL;
84 unsigned int _dl_skip_args attribute_relro attribute_hidden;
85 #endif
86 INTDEF(_dl_argv)
88 #ifndef THREAD_SET_STACK_GUARD
89 /* Only exported for architectures that don't store the stack guard canary
90 in thread local area. */
91 uintptr_t __stack_chk_guard attribute_relro;
92 #endif
94 /* Only exported for architectures that don't store the pointer guard
95 value in thread local area. */
96 uintptr_t __pointer_chk_guard_local
97 attribute_relro attribute_hidden __attribute__ ((nocommon));
98 #ifndef THREAD_SET_POINTER_GUARD
99 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
100 #endif
103 /* List of auditing DSOs. */
104 static struct audit_list
106 const char *name;
107 struct audit_list *next;
108 } *audit_list;
110 /* 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)
120 /* This is the structure which defines all variables global to ld.so
121 (except those which cannot be added for some reason). */
122 struct rtld_global _rtld_global =
124 /* Generally the default presumption without further information is an
125 * executable stack but this is not true for all platforms. */
126 ._dl_stack_flags = DEFAULT_STACK_PERMS,
127 #ifdef _LIBC_REENTRANT
128 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
129 ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
130 #endif
131 ._dl_nns = 1,
132 ._dl_ns =
134 [LM_ID_BASE] = { ._ns_unique_sym_table
135 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
138 /* If we would use strong_alias here the compiler would see a
139 non-hidden definition. This would undo the effect of the previous
140 declaration. So spell out was strong_alias does plus add the
141 visibility attribute. */
142 extern struct rtld_global _rtld_local
143 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
146 /* This variable is similar to _rtld_local, but all values are
147 read-only after relocation. */
148 struct rtld_global_ro _rtld_global_ro attribute_relro =
150 /* Get architecture specific initializer. */
151 #include <dl-procinfo.c>
152 #ifdef NEED_DL_SYSINFO
153 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
154 #endif
155 ._dl_debug_fd = STDERR_FILENO,
156 ._dl_use_load_bias = -2,
157 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
158 ._dl_hwcap_mask = HWCAP_IMPORTANT,
159 ._dl_lazy = 1,
160 ._dl_fpu_control = _FPU_DEFAULT,
161 ._dl_pointer_guard = 1,
163 /* Function pointers. */
164 ._dl_debug_printf = _dl_debug_printf,
165 ._dl_catch_error = _dl_catch_error,
166 ._dl_signal_error = _dl_signal_error,
167 ._dl_mcount = _dl_mcount_internal,
168 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
169 ._dl_check_caller = _dl_check_caller,
170 ._dl_open = _dl_open,
171 ._dl_close = _dl_close,
172 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
173 #ifdef HAVE_DL_DISCOVER_OSVERSION
174 ._dl_discover_osversion = _dl_discover_osversion
175 #endif
177 /* If we would use strong_alias here the compiler would see a
178 non-hidden definition. This would undo the effect of the previous
179 declaration. So spell out was strong_alias does plus add the
180 visibility attribute. */
181 extern struct rtld_global_ro _rtld_local_ro
182 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
185 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
186 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
188 /* These two variables cannot be moved into .data.rel.ro. */
189 static struct libname_list _dl_rtld_libname;
190 static struct libname_list _dl_rtld_libname2;
192 /* We expect less than a second for relocation. */
193 #ifdef HP_SMALL_TIMING_AVAIL
194 # undef HP_TIMING_AVAIL
195 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
196 #endif
198 /* Variable for statistics. */
199 #ifndef HP_TIMING_NONAVAIL
200 static hp_timing_t relocate_time;
201 static hp_timing_t load_time attribute_relro;
202 static hp_timing_t start_time attribute_relro;
203 #endif
205 /* Additional definitions needed by TLS initialization. */
206 #ifdef TLS_INIT_HELPER
207 TLS_INIT_HELPER
208 #endif
210 /* Helper function for syscall implementation. */
211 #ifdef DL_SYSINFO_IMPLEMENTATION
212 DL_SYSINFO_IMPLEMENTATION
213 #endif
215 /* Before ld.so is relocated we must not access variables which need
216 relocations. This means variables which are exported. Variables
217 declared as static are fine. If we can mark a variable hidden this
218 is fine, too. The latter is important here. We can avoid setting
219 up a temporary link map for ld.so if we can mark _rtld_global as
220 hidden. */
221 #ifdef PI_STATIC_AND_HIDDEN
222 # define DONT_USE_BOOTSTRAP_MAP 1
223 #endif
225 #ifdef DONT_USE_BOOTSTRAP_MAP
226 static ElfW(Addr) _dl_start_final (void *arg);
227 #else
228 struct dl_start_final_info
230 struct link_map l;
231 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
232 hp_timing_t start_time;
233 #endif
235 static ElfW(Addr) _dl_start_final (void *arg,
236 struct dl_start_final_info *info);
237 #endif
239 /* These defined magically in the linker script. */
240 extern char _begin[] attribute_hidden;
241 extern char _etext[] attribute_hidden;
242 extern char _end[] attribute_hidden;
245 #ifdef RTLD_START
246 RTLD_START
247 #else
248 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
249 #endif
251 #ifndef VALIDX
252 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
253 + DT_EXTRANUM + DT_VALTAGIDX (tag))
254 #endif
255 #ifndef ADDRIDX
256 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
257 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
258 #endif
260 /* This is the second half of _dl_start (below). It can be inlined safely
261 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
262 references. When the tools don't permit us to avoid using a GOT entry
263 for _dl_rtld_global (no attribute_hidden support), we must make sure
264 this function is not inlined (see below). */
266 #ifdef DONT_USE_BOOTSTRAP_MAP
267 static inline ElfW(Addr) __attribute__ ((always_inline))
268 _dl_start_final (void *arg)
269 #else
270 static ElfW(Addr) __attribute__ ((noinline))
271 _dl_start_final (void *arg, struct dl_start_final_info *info)
272 #endif
274 ElfW(Addr) start_addr;
276 if (HP_TIMING_AVAIL)
278 /* If it hasn't happen yet record the startup time. */
279 if (! HP_TIMING_INLINE)
280 HP_TIMING_NOW (start_time);
281 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
282 else
283 start_time = info->start_time;
284 #endif
286 /* Initialize the timing functions. */
287 HP_TIMING_DIFF_INIT ();
290 /* Transfer data about ourselves to the permanent link_map structure. */
291 #ifndef DONT_USE_BOOTSTRAP_MAP
292 GL(dl_rtld_map).l_addr = info->l.l_addr;
293 GL(dl_rtld_map).l_ld = info->l.l_ld;
294 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
295 sizeof GL(dl_rtld_map).l_info);
296 GL(dl_rtld_map).l_mach = info->l.l_mach;
297 GL(dl_rtld_map).l_relocated = 1;
298 #endif
299 _dl_setup_hash (&GL(dl_rtld_map));
300 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
301 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
302 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
303 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
304 /* Copy the TLS related data if necessary. */
305 #ifndef DONT_USE_BOOTSTRAP_MAP
306 # if USE___THREAD
307 assert (info->l.l_tls_modid != 0);
308 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
309 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
310 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
311 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
312 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
313 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
314 GL(dl_rtld_map).l_tls_modid = 1;
315 # else
316 # if NO_TLS_OFFSET != 0
317 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
318 # endif
319 # endif
321 #endif
323 #if HP_TIMING_AVAIL
324 HP_TIMING_NOW (GL(dl_cpuclock_offset));
325 #endif
327 /* Initialize the stack end variable. */
328 __libc_stack_end = __builtin_frame_address (0);
330 /* Call the OS-dependent function to set up life so we can do things like
331 file access. It will call `dl_main' (below) to do all the real work
332 of the dynamic linker, and then unwind our frame and run the user
333 entry point on the same stack we entered on. */
334 start_addr = _dl_sysdep_start (arg, &dl_main);
336 #ifndef HP_TIMING_NONAVAIL
337 hp_timing_t rtld_total_time;
338 if (HP_TIMING_AVAIL)
340 hp_timing_t end_time;
342 /* Get the current time. */
343 HP_TIMING_NOW (end_time);
345 /* Compute the difference. */
346 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
348 #endif
350 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
352 #ifndef HP_TIMING_NONAVAIL
353 print_statistics (&rtld_total_time);
354 #else
355 print_statistics (NULL);
356 #endif
359 return start_addr;
362 static ElfW(Addr) __attribute_used__ internal_function
363 _dl_start (void *arg)
365 #ifdef DONT_USE_BOOTSTRAP_MAP
366 # define bootstrap_map GL(dl_rtld_map)
367 #else
368 struct dl_start_final_info info;
369 # define bootstrap_map info.l
370 #endif
372 /* This #define produces dynamic linking inline functions for
373 bootstrap relocation instead of general-purpose relocation.
374 Since ld.so must not have any undefined symbols the result
375 is trivial: always the map of ld.so itself. */
376 #define RTLD_BOOTSTRAP
377 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
378 #include "dynamic-link.h"
380 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
381 #ifdef DONT_USE_BOOTSTRAP_MAP
382 HP_TIMING_NOW (start_time);
383 #else
384 HP_TIMING_NOW (info.start_time);
385 #endif
387 /* Partly clean the `bootstrap_map' structure up. Don't use
388 `memset' since it might not be built in or inlined and we cannot
389 make function calls at this point. Use '__builtin_memset' if we
390 know it is available. We do not have to clear the memory if we
391 do not have to use the temporary bootstrap_map. Global variables
392 are initialized to zero by default. */
393 #ifndef DONT_USE_BOOTSTRAP_MAP
394 # ifdef HAVE_BUILTIN_MEMSET
395 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
396 # else
397 for (size_t cnt = 0;
398 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
399 ++cnt)
400 bootstrap_map.l_info[cnt] = 0;
401 # endif
402 # if USE___THREAD
403 bootstrap_map.l_tls_modid = 0;
404 # endif
405 #endif
407 /* Figure out the run-time load address of the dynamic linker itself. */
408 bootstrap_map.l_addr = elf_machine_load_address ();
410 /* Read our own dynamic section and fill in the info array. */
411 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
412 elf_get_dynamic_info (&bootstrap_map, NULL);
414 #if NO_TLS_OFFSET != 0
415 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
416 #endif
418 /* Get the dynamic linker's own program header. First we need the ELF
419 file header. The `_begin' symbol created by the linker script points
420 to it. When we have something like GOTOFF relocs, we can use a plain
421 reference to find the runtime address. Without that, we have to rely
422 on the `l_addr' value, which is not the value we want when prelinked. */
423 #if USE___THREAD
424 dtv_t initdtv[3];
425 ElfW(Ehdr) *ehdr
426 # ifdef DONT_USE_BOOTSTRAP_MAP
427 = (ElfW(Ehdr) *) &_begin;
428 # else
429 # error This will not work with prelink.
430 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
431 # endif
432 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
433 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
434 while (cnt-- > 0)
435 if (phdr[cnt].p_type == PT_TLS)
437 void *tlsblock;
438 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
439 char *p;
441 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
442 bootstrap_map.l_tls_align = phdr[cnt].p_align;
443 if (phdr[cnt].p_align == 0)
444 bootstrap_map.l_tls_firstbyte_offset = 0;
445 else
446 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
447 & (phdr[cnt].p_align - 1));
448 assert (bootstrap_map.l_tls_blocksize != 0);
449 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
450 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
451 + phdr[cnt].p_vaddr);
453 /* We can now allocate the initial TLS block. This can happen
454 on the stack. We'll get the final memory later when we
455 know all about the various objects loaded at startup
456 time. */
457 # if TLS_TCB_AT_TP
458 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
459 TLS_INIT_TCB_ALIGN)
460 + TLS_INIT_TCB_SIZE
461 + max_align);
462 # elif TLS_DTV_AT_TP
463 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
464 bootstrap_map.l_tls_align)
465 + bootstrap_map.l_tls_blocksize
466 + max_align);
467 # else
468 /* In case a model with a different layout for the TCB and DTV
469 is defined add another #elif here and in the following #ifs. */
470 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
471 # endif
472 /* Align the TLS block. */
473 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
474 & ~(max_align - 1));
476 /* Initialize the dtv. [0] is the length, [1] the generation
477 counter. */
478 initdtv[0].counter = 1;
479 initdtv[1].counter = 0;
481 /* Initialize the TLS block. */
482 # if TLS_TCB_AT_TP
483 initdtv[2].pointer = tlsblock;
484 # elif TLS_DTV_AT_TP
485 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
486 bootstrap_map.l_tls_align);
487 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
488 # else
489 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
490 # endif
491 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
492 bootstrap_map.l_tls_initimage_size);
493 # ifdef HAVE_BUILTIN_MEMSET
494 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
495 - bootstrap_map.l_tls_initimage_size));
496 # else
498 size_t remaining = (bootstrap_map.l_tls_blocksize
499 - bootstrap_map.l_tls_initimage_size);
500 while (remaining-- > 0)
501 *p++ = '\0';
503 # endif
505 /* Install the pointer to the dtv. */
507 /* Initialize the thread pointer. */
508 # if TLS_TCB_AT_TP
509 bootstrap_map.l_tls_offset
510 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
512 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
513 initdtv);
515 const char *lossage = TLS_INIT_TP ((char *) tlsblock
516 + bootstrap_map.l_tls_offset, 0);
517 # elif TLS_DTV_AT_TP
518 INSTALL_DTV (tlsblock, initdtv);
519 const char *lossage = TLS_INIT_TP (tlsblock, 0);
520 # else
521 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
522 # endif
523 if (__builtin_expect (lossage != NULL, 0))
524 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
525 lossage);
527 /* So far this is module number one. */
528 bootstrap_map.l_tls_modid = 1;
530 /* There can only be one PT_TLS entry. */
531 break;
533 #endif /* USE___THREAD */
535 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
536 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
537 #endif
539 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
541 /* Relocate ourselves so we can do normal function calls and
542 data access using the global offset table. */
544 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
546 bootstrap_map.l_relocated = 1;
548 /* Please note that we don't allow profiling of this object and
549 therefore need not test whether we have to allocate the array
550 for the relocation results (as done in dl-reloc.c). */
552 /* Now life is sane; we can call functions and access global data.
553 Set up to use the operating system facilities, and find out from
554 the operating system's program loader where to find the program
555 header table in core. Put the rest of _dl_start into a separate
556 function, that way the compiler cannot put accesses to the GOT
557 before ELF_DYNAMIC_RELOCATE. */
559 #ifdef DONT_USE_BOOTSTRAP_MAP
560 ElfW(Addr) entry = _dl_start_final (arg);
561 #else
562 ElfW(Addr) entry = _dl_start_final (arg, &info);
563 #endif
565 #ifndef ELF_MACHINE_START_ADDRESS
566 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
567 #endif
569 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
575 /* Now life is peachy; we can do all normal operations.
576 On to the real work. */
578 /* Some helper functions. */
580 /* Arguments to relocate_doit. */
581 struct relocate_args
583 struct link_map *l;
584 int reloc_mode;
587 struct map_args
589 /* Argument to map_doit. */
590 char *str;
591 struct link_map *loader;
592 int mode;
593 /* Return value of map_doit. */
594 struct link_map *map;
597 struct dlmopen_args
599 const char *fname;
600 struct link_map *map;
603 struct lookup_args
605 const char *name;
606 struct link_map *map;
607 void *result;
610 /* Arguments to version_check_doit. */
611 struct version_check_args
613 int doexit;
614 int dotrace;
617 static void
618 relocate_doit (void *a)
620 struct relocate_args *args = (struct relocate_args *) a;
622 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
625 static void
626 map_doit (void *a)
628 struct map_args *args = (struct map_args *) a;
629 args->map = _dl_map_object (args->loader, args->str, lt_library, 0,
630 args->mode, LM_ID_BASE);
633 static void
634 dlmopen_doit (void *a)
636 struct dlmopen_args *args = (struct dlmopen_args *) a;
637 args->map = _dl_open (args->fname,
638 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
639 | __RTLD_SECURE),
640 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
641 __environ);
644 static void
645 lookup_doit (void *a)
647 struct lookup_args *args = (struct lookup_args *) a;
648 const ElfW(Sym) *ref = NULL;
649 args->result = NULL;
650 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
651 args->map->l_local_scope, NULL, 0,
652 DL_LOOKUP_RETURN_NEWEST, NULL);
653 if (ref != NULL)
654 args->result = DL_SYMBOL_ADDRESS (l, ref);
657 static void
658 version_check_doit (void *a)
660 struct version_check_args *args = (struct version_check_args *) a;
661 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
662 args->dotrace) && args->doexit)
663 /* We cannot start the application. Abort now. */
664 _exit (1);
668 static inline struct link_map *
669 find_needed (const char *name)
671 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
672 unsigned int n = scope->r_nlist;
674 while (n-- > 0)
675 if (_dl_name_match_p (name, scope->r_list[n]))
676 return scope->r_list[n];
678 /* Should never happen. */
679 return NULL;
682 static int
683 match_version (const char *string, struct link_map *map)
685 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
686 ElfW(Verdef) *def;
688 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
689 if (map->l_info[VERDEFTAG] == NULL)
690 /* The file has no symbol versioning. */
691 return 0;
693 def = (ElfW(Verdef) *) ((char *) map->l_addr
694 + map->l_info[VERDEFTAG]->d_un.d_ptr);
695 while (1)
697 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
699 /* Compare the version strings. */
700 if (strcmp (string, strtab + aux->vda_name) == 0)
701 /* Bingo! */
702 return 1;
704 /* If no more definitions we failed to find what we want. */
705 if (def->vd_next == 0)
706 break;
708 /* Next definition. */
709 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
712 return 0;
715 static bool tls_init_tp_called;
717 static void *
718 init_tls (void)
720 /* Number of elements in the static TLS block. */
721 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
723 /* Do not do this twice. The audit interface might have required
724 the DTV interfaces to be set up early. */
725 if (GL(dl_initial_dtv) != NULL)
726 return NULL;
728 /* Allocate the array which contains the information about the
729 dtv slots. We allocate a few entries more than needed to
730 avoid the need for reallocation. */
731 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
733 /* Allocate. */
734 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
735 calloc (sizeof (struct dtv_slotinfo_list)
736 + nelem * sizeof (struct dtv_slotinfo), 1);
737 /* No need to check the return value. If memory allocation failed
738 the program would have been terminated. */
740 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
741 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
742 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
744 /* Fill in the information from the loaded modules. No namespace
745 but the base one can be filled at this time. */
746 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
747 int i = 0;
748 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
749 l = l->l_next)
750 if (l->l_tls_blocksize != 0)
752 /* This is a module with TLS data. Store the map reference.
753 The generation counter is zero. */
754 slotinfo[i].map = l;
755 /* slotinfo[i].gen = 0; */
756 ++i;
758 assert (i == GL(dl_tls_max_dtv_idx));
760 /* Compute the TLS offsets for the various blocks. */
761 _dl_determine_tlsoffset ();
763 /* Construct the static TLS block and the dtv for the initial
764 thread. For some platforms this will include allocating memory
765 for the thread descriptor. The memory for the TLS block will
766 never be freed. It should be allocated accordingly. The dtv
767 array can be changed if dynamic loading requires it. */
768 void *tcbp = _dl_allocate_tls_storage ();
769 if (tcbp == NULL)
770 _dl_fatal_printf ("\
771 cannot allocate TLS data structures for initial thread");
773 /* Store for detection of the special case by __tls_get_addr
774 so it knows not to pass this dtv to the normal realloc. */
775 GL(dl_initial_dtv) = GET_DTV (tcbp);
777 /* And finally install it for the main thread. If ld.so itself uses
778 TLS we know the thread pointer was initialized earlier. */
779 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
780 if (__builtin_expect (lossage != NULL, 0))
781 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
782 tls_init_tp_called = true;
784 return tcbp;
787 #ifdef _LIBC_REENTRANT
788 /* _dl_error_catch_tsd points to this for the single-threaded case.
789 It's reset by the thread library for multithreaded programs. */
790 void ** __attribute__ ((const))
791 _dl_initial_error_catch_tsd (void)
793 static void *data;
794 return &data;
796 #endif
799 static unsigned int
800 do_preload (char *fname, struct link_map *main_map, const char *where)
802 const char *objname;
803 const char *err_str = NULL;
804 struct map_args args;
805 bool malloced;
807 args.str = fname;
808 args.loader = main_map;
809 args.mode = __RTLD_SECURE;
811 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
813 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
814 if (__builtin_expect (err_str != NULL, 0))
816 _dl_error_printf ("\
817 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
818 fname, where);
819 /* No need to call free, this is still before
820 the libc's malloc is used. */
822 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
823 /* It is no duplicate. */
824 return 1;
826 /* Nothing loaded. */
827 return 0;
830 #if defined SHARED && defined _LIBC_REENTRANT \
831 && defined __rtld_lock_default_lock_recursive
832 static void
833 rtld_lock_default_lock_recursive (void *lock)
835 __rtld_lock_default_lock_recursive (lock);
838 static void
839 rtld_lock_default_unlock_recursive (void *lock)
841 __rtld_lock_default_unlock_recursive (lock);
843 #endif
846 static void
847 security_init (void)
849 /* Set up the stack checker's canary. */
850 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
851 #ifdef THREAD_SET_STACK_GUARD
852 THREAD_SET_STACK_GUARD (stack_chk_guard);
853 #else
854 __stack_chk_guard = stack_chk_guard;
855 #endif
857 /* Set up the pointer guard as well, if necessary. */
858 if (GLRO(dl_pointer_guard))
860 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
861 stack_chk_guard);
862 #ifdef THREAD_SET_POINTER_GUARD
863 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
864 #endif
865 __pointer_chk_guard_local = pointer_chk_guard;
868 /* We do not need the _dl_random value anymore. The less
869 information we leave behind, the better, so clear the
870 variable. */
871 _dl_random = NULL;
875 /* The library search path. */
876 static const char *library_path attribute_relro;
877 /* The list preloaded objects. */
878 static const char *preloadlist attribute_relro;
879 /* Nonzero if information about versions has to be printed. */
880 static int version_info attribute_relro;
882 static void
883 dl_main (const ElfW(Phdr) *phdr,
884 ElfW(Word) phnum,
885 ElfW(Addr) *user_entry,
886 ElfW(auxv_t) *auxv)
888 const ElfW(Phdr) *ph;
889 enum mode mode;
890 struct link_map *main_map;
891 size_t file_size;
892 char *file;
893 bool has_interp = false;
894 unsigned int i;
895 bool prelinked = false;
896 bool rtld_is_main = false;
897 #ifndef HP_TIMING_NONAVAIL
898 hp_timing_t start;
899 hp_timing_t stop;
900 hp_timing_t diff;
901 #endif
902 void *tcbp = NULL;
904 #ifdef _LIBC_REENTRANT
905 /* Explicit initialization since the reloc would just be more work. */
906 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
907 #endif
909 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
911 #if defined SHARED && defined _LIBC_REENTRANT \
912 && defined __rtld_lock_default_lock_recursive
913 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
914 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
915 #endif
917 /* The explicit initialization here is cheaper than processing the reloc
918 in the _rtld_local definition's initializer. */
919 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
921 /* Process the environment variable which control the behaviour. */
922 process_envvars (&mode);
924 /* Set up a flag which tells we are just starting. */
925 INTUSE(_dl_starting_up) = 1;
927 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
929 /* Ho ho. We are not the program interpreter! We are the program
930 itself! This means someone ran ld.so as a command. Well, that
931 might be convenient to do sometimes. We support it by
932 interpreting the args like this:
934 ld.so PROGRAM ARGS...
936 The first argument is the name of a file containing an ELF
937 executable we will load and run with the following arguments.
938 To simplify life here, PROGRAM is searched for using the
939 normal rules for shared objects, rather than $PATH or anything
940 like that. We just load it and use its entry point; we don't
941 pay attention to its PT_INTERP command (we are the interpreter
942 ourselves). This is an easy way to test a new ld.so before
943 installing it. */
944 rtld_is_main = true;
946 /* Note the place where the dynamic linker actually came from. */
947 GL(dl_rtld_map).l_name = rtld_progname;
949 while (_dl_argc > 1)
950 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
952 mode = list;
953 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
955 ++_dl_skip_args;
956 --_dl_argc;
957 ++INTUSE(_dl_argv);
959 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
961 mode = verify;
963 ++_dl_skip_args;
964 --_dl_argc;
965 ++INTUSE(_dl_argv);
967 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
968 && _dl_argc > 2)
970 library_path = 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], "--inhibit-rpath")
977 && _dl_argc > 2)
979 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
981 _dl_skip_args += 2;
982 _dl_argc -= 2;
983 INTUSE(_dl_argv) += 2;
985 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
987 process_dl_audit (INTUSE(_dl_argv)[2]);
989 _dl_skip_args += 2;
990 _dl_argc -= 2;
991 INTUSE(_dl_argv) += 2;
993 else
994 break;
996 /* If we have no further argument the program was called incorrectly.
997 Grant the user some education. */
998 if (_dl_argc < 2)
999 _dl_fatal_printf ("\
1000 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1001 You have invoked `ld.so', the helper program for shared library executables.\n\
1002 This program usually lives in the file `/lib/ld.so', and special directives\n\
1003 in executable files using ELF shared libraries tell the system's program\n\
1004 loader to load the helper program from this file. This helper program loads\n\
1005 the shared libraries needed by the program executable, prepares the program\n\
1006 to run, and runs it. You may invoke this helper program directly from the\n\
1007 command line to load and run an ELF executable file; this is like executing\n\
1008 that file itself, but always uses this helper program from the file you\n\
1009 specified, instead of the helper program file specified in the executable\n\
1010 file you run. This is mostly of use for maintainers to test new versions\n\
1011 of this helper program; chances are you did not intend to run this program.\n\
1013 --list list all dependencies and how they are resolved\n\
1014 --verify verify that given object really is a dynamically linked\n\
1015 object we can handle\n\
1016 --library-path PATH use given PATH instead of content of the environment\n\
1017 variable LD_LIBRARY_PATH\n\
1018 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1019 in LIST\n\
1020 --audit LIST use objects named in LIST as auditors\n");
1022 ++_dl_skip_args;
1023 --_dl_argc;
1024 ++INTUSE(_dl_argv);
1026 /* The initialization of _dl_stack_flags done below assumes the
1027 executable's PT_GNU_STACK may have been honored by the kernel, and
1028 so a PT_GNU_STACK with PF_X set means the stack started out with
1029 execute permission. However, this is not really true if the
1030 dynamic linker is the executable the kernel loaded. For this
1031 case, we must reinitialize _dl_stack_flags to match the dynamic
1032 linker itself. If the dynamic linker was built with a
1033 PT_GNU_STACK, then the kernel may have loaded us with a
1034 nonexecutable stack that we will have to make executable when we
1035 load the program below unless it has a PT_GNU_STACK indicating
1036 nonexecutable stack is ok. */
1038 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1039 if (ph->p_type == PT_GNU_STACK)
1041 GL(dl_stack_flags) = ph->p_flags;
1042 break;
1045 if (__builtin_expect (mode, normal) == verify)
1047 const char *objname;
1048 const char *err_str = NULL;
1049 struct map_args args;
1050 bool malloced;
1052 args.str = rtld_progname;
1053 args.loader = NULL;
1054 args.mode = __RTLD_OPENEXEC;
1055 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1056 &args);
1057 if (__builtin_expect (err_str != NULL, 0))
1058 /* We don't free the returned string, the programs stops
1059 anyway. */
1060 _exit (EXIT_FAILURE);
1062 else
1064 HP_TIMING_NOW (start);
1065 _dl_map_object (NULL, rtld_progname, lt_library, 0,
1066 __RTLD_OPENEXEC, LM_ID_BASE);
1067 HP_TIMING_NOW (stop);
1069 HP_TIMING_DIFF (load_time, start, stop);
1072 /* Now the map for the main executable is available. */
1073 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1075 phdr = main_map->l_phdr;
1076 phnum = main_map->l_phnum;
1077 /* We overwrite here a pointer to a malloc()ed string. But since
1078 the malloc() implementation used at this point is the dummy
1079 implementations which has no real free() function it does not
1080 makes sense to free the old string first. */
1081 main_map->l_name = (char *) "";
1082 *user_entry = main_map->l_entry;
1084 #ifdef HAVE_AUX_VECTOR
1085 /* Adjust the on-stack auxiliary vector so that it looks like the
1086 binary was executed directly. */
1087 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1088 switch (av->a_type)
1090 case AT_PHDR:
1091 av->a_un.a_val = (uintptr_t) phdr;
1092 break;
1093 case AT_PHNUM:
1094 av->a_un.a_val = phnum;
1095 break;
1096 case AT_ENTRY:
1097 av->a_un.a_val = *user_entry;
1098 break;
1100 #endif
1102 else
1104 /* Create a link_map for the executable itself.
1105 This will be what dlopen on "" returns. */
1106 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1107 __RTLD_OPENEXEC, LM_ID_BASE);
1108 assert (main_map != NULL);
1109 main_map->l_phdr = phdr;
1110 main_map->l_phnum = phnum;
1111 main_map->l_entry = *user_entry;
1113 /* Even though the link map is not yet fully initialized we can add
1114 it to the map list since there are no possible users running yet. */
1115 _dl_add_to_namespace_list (main_map, LM_ID_BASE);
1116 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1118 /* At this point we are in a bit of trouble. We would have to
1119 fill in the values for l_dev and l_ino. But in general we
1120 do not know where the file is. We also do not handle AT_EXECFD
1121 even if it would be passed up.
1123 We leave the values here defined to 0. This is normally no
1124 problem as the program code itself is normally no shared
1125 object and therefore cannot be loaded dynamically. Nothing
1126 prevent the use of dynamic binaries and in these situations
1127 we might get problems. We might not be able to find out
1128 whether the object is already loaded. But since there is no
1129 easy way out and because the dynamic binary must also not
1130 have an SONAME we ignore this program for now. If it becomes
1131 a problem we can force people using SONAMEs. */
1133 /* We delay initializing the path structure until we got the dynamic
1134 information for the program. */
1137 main_map->l_map_end = 0;
1138 main_map->l_text_end = 0;
1139 /* Perhaps the executable has no PT_LOAD header entries at all. */
1140 main_map->l_map_start = ~0;
1141 /* And it was opened directly. */
1142 ++main_map->l_direct_opencount;
1144 /* Scan the program header table for the dynamic section. */
1145 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1146 switch (ph->p_type)
1148 case PT_PHDR:
1149 /* Find out the load address. */
1150 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1151 break;
1152 case PT_DYNAMIC:
1153 /* This tells us where to find the dynamic section,
1154 which tells us everything we need to do. */
1155 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1156 break;
1157 case PT_INTERP:
1158 /* This "interpreter segment" was used by the program loader to
1159 find the program interpreter, which is this program itself, the
1160 dynamic linker. We note what name finds us, so that a future
1161 dlopen call or DT_NEEDED entry, for something that wants to link
1162 against the dynamic linker as a shared library, will know that
1163 the shared object is already loaded. */
1164 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1165 + ph->p_vaddr);
1166 /* _dl_rtld_libname.next = NULL; Already zero. */
1167 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1169 /* Ordinarilly, we would get additional names for the loader from
1170 our DT_SONAME. This can't happen if we were actually linked as
1171 a static executable (detect this case when we have no DYNAMIC).
1172 If so, assume the filename component of the interpreter path to
1173 be our SONAME, and add it to our name list. */
1174 if (GL(dl_rtld_map).l_ld == NULL)
1176 const char *p = NULL;
1177 const char *cp = _dl_rtld_libname.name;
1179 /* Find the filename part of the path. */
1180 while (*cp != '\0')
1181 if (*cp++ == '/')
1182 p = cp;
1184 if (p != NULL)
1186 _dl_rtld_libname2.name = p;
1187 /* _dl_rtld_libname2.next = NULL; Already zero. */
1188 _dl_rtld_libname.next = &_dl_rtld_libname2;
1192 has_interp = true;
1193 break;
1194 case PT_LOAD:
1196 ElfW(Addr) mapstart;
1197 ElfW(Addr) allocend;
1199 /* Remember where the main program starts in memory. */
1200 mapstart = (main_map->l_addr
1201 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1202 if (main_map->l_map_start > mapstart)
1203 main_map->l_map_start = mapstart;
1205 /* Also where it ends. */
1206 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1207 if (main_map->l_map_end < allocend)
1208 main_map->l_map_end = allocend;
1209 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1210 main_map->l_text_end = allocend;
1212 break;
1214 case PT_TLS:
1215 if (ph->p_memsz > 0)
1217 /* Note that in the case the dynamic linker we duplicate work
1218 here since we read the PT_TLS entry already in
1219 _dl_start_final. But the result is repeatable so do not
1220 check for this special but unimportant case. */
1221 main_map->l_tls_blocksize = ph->p_memsz;
1222 main_map->l_tls_align = ph->p_align;
1223 if (ph->p_align == 0)
1224 main_map->l_tls_firstbyte_offset = 0;
1225 else
1226 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1227 & (ph->p_align - 1));
1228 main_map->l_tls_initimage_size = ph->p_filesz;
1229 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1231 /* This image gets the ID one. */
1232 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1234 break;
1236 case PT_GNU_STACK:
1237 GL(dl_stack_flags) = ph->p_flags;
1238 break;
1240 case PT_GNU_RELRO:
1241 main_map->l_relro_addr = ph->p_vaddr;
1242 main_map->l_relro_size = ph->p_memsz;
1243 break;
1246 /* Adjust the address of the TLS initialization image in case
1247 the executable is actually an ET_DYN object. */
1248 if (main_map->l_tls_initimage != NULL)
1249 main_map->l_tls_initimage
1250 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1251 if (! main_map->l_map_end)
1252 main_map->l_map_end = ~0;
1253 if (! main_map->l_text_end)
1254 main_map->l_text_end = ~0;
1255 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1257 /* We were invoked directly, so the program might not have a
1258 PT_INTERP. */
1259 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1260 /* _dl_rtld_libname.next = NULL; Already zero. */
1261 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1263 else
1264 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1266 /* If the current libname is different from the SONAME, add the
1267 latter as well. */
1268 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1269 && strcmp (GL(dl_rtld_map).l_libname->name,
1270 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1271 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1273 static struct libname_list newname;
1274 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1275 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1276 newname.next = NULL;
1277 newname.dont_free = 1;
1279 assert (GL(dl_rtld_map).l_libname->next == NULL);
1280 GL(dl_rtld_map).l_libname->next = &newname;
1282 /* The ld.so must be relocated since otherwise loading audit modules
1283 will fail since they reuse the very same ld.so. */
1284 assert (GL(dl_rtld_map).l_relocated);
1286 if (! rtld_is_main)
1288 /* Extract the contents of the dynamic section for easy access. */
1289 elf_get_dynamic_info (main_map, NULL);
1290 /* Set up our cache of pointers into the hash table. */
1291 _dl_setup_hash (main_map);
1294 if (__builtin_expect (mode, normal) == verify)
1296 /* We were called just to verify that this is a dynamic
1297 executable using us as the program interpreter. Exit with an
1298 error if we were not able to load the binary or no interpreter
1299 is specified (i.e., this is no dynamically linked binary. */
1300 if (main_map->l_ld == NULL)
1301 _exit (1);
1303 /* We allow here some platform specific code. */
1304 #ifdef DISTINGUISH_LIB_VERSIONS
1305 DISTINGUISH_LIB_VERSIONS;
1306 #endif
1307 _exit (has_interp ? 0 : 2);
1310 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1311 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1312 /* Set up the data structures for the system-supplied DSO early,
1313 so they can influence _dl_init_paths. */
1314 if (GLRO(dl_sysinfo_dso) != NULL)
1316 /* Do an abridged version of the work _dl_map_object_from_fd would do
1317 to map in the object. It's already mapped and prelinked (and
1318 better be, since it's read-only and so we couldn't relocate it).
1319 We just want our data structures to describe it as if we had just
1320 mapped and relocated it normally. */
1321 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1322 0, LM_ID_BASE);
1323 if (__builtin_expect (l != NULL, 1))
1325 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1327 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1328 + GLRO(dl_sysinfo_dso)->e_phoff);
1329 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1330 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1332 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1333 if (ph->p_type == PT_DYNAMIC)
1335 l->l_ld = (void *) ph->p_vaddr;
1336 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1338 else if (ph->p_type == PT_LOAD)
1340 if (! l->l_addr)
1341 l->l_addr = ph->p_vaddr;
1342 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1343 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1344 if ((ph->p_flags & PF_X)
1345 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1346 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1348 else
1349 /* There must be no TLS segment. */
1350 assert (ph->p_type != PT_TLS);
1352 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1353 l->l_addr = l->l_map_start - l->l_addr;
1354 l->l_map_end += l->l_addr;
1355 l->l_text_end += l->l_addr;
1356 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1357 elf_get_dynamic_info (l, dyn_temp);
1358 _dl_setup_hash (l);
1359 l->l_relocated = 1;
1361 /* Initialize l_local_scope to contain just this map. This allows
1362 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1363 So we create a single entry list pointing to l_real as its only
1364 element */
1365 l->l_local_scope[0]->r_nlist = 1;
1366 l->l_local_scope[0]->r_list = &l->l_real;
1368 /* Now that we have the info handy, use the DSO image's soname
1369 so this object can be looked up by name. Note that we do not
1370 set l_name here. That field gives the file name of the DSO,
1371 and this DSO is not associated with any file. */
1372 if (l->l_info[DT_SONAME] != NULL)
1374 /* Work around a kernel problem. The kernel cannot handle
1375 addresses in the vsyscall DSO pages in writev() calls. */
1376 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1377 + l->l_info[DT_SONAME]->d_un.d_val);
1378 size_t len = strlen (dsoname);
1379 char *copy = malloc (len);
1380 if (copy == NULL)
1381 _dl_fatal_printf ("out of memory\n");
1382 l->l_libname->name = memcpy (copy, dsoname, len);
1385 /* Add the vDSO to the object list. */
1386 _dl_add_to_namespace_list (l, LM_ID_BASE);
1388 /* Rearrange the list so this DSO appears after rtld_map. */
1389 assert (l->l_next == NULL);
1390 assert (l->l_prev == main_map);
1391 GL(dl_rtld_map).l_next = l;
1392 l->l_prev = &GL(dl_rtld_map);
1393 first_preload = &l->l_next;
1395 /* We have a prelinked DSO preloaded by the system. */
1396 GLRO(dl_sysinfo_map) = l;
1397 # ifdef NEED_DL_SYSINFO
1398 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1399 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1400 # endif
1403 #endif
1405 #ifdef DL_SYSDEP_OSCHECK
1406 DL_SYSDEP_OSCHECK (dl_fatal);
1407 #endif
1409 /* Initialize the data structures for the search paths for shared
1410 objects. */
1411 _dl_init_paths (library_path);
1413 /* Initialize _r_debug. */
1414 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1415 LM_ID_BASE);
1416 r->r_state = RT_CONSISTENT;
1418 /* Put the link_map for ourselves on the chain so it can be found by
1419 name. Note that at this point the global chain of link maps contains
1420 exactly one element, which is pointed to by dl_loaded. */
1421 if (! GL(dl_rtld_map).l_name)
1422 /* If not invoked directly, the dynamic linker shared object file was
1423 found by the PT_INTERP name. */
1424 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1425 GL(dl_rtld_map).l_type = lt_library;
1426 main_map->l_next = &GL(dl_rtld_map);
1427 GL(dl_rtld_map).l_prev = main_map;
1428 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1429 ++GL(dl_load_adds);
1431 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1432 to not using bias for non-prelinked PIEs and libraries
1433 and using it for executables or prelinked PIEs or libraries. */
1434 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1435 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1437 /* Set up the program header information for the dynamic linker
1438 itself. It is needed in the dl_iterate_phdr() callbacks. */
1439 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1440 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1441 + rtld_ehdr->e_phoff);
1442 GL(dl_rtld_map).l_phdr = rtld_phdr;
1443 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1446 /* PT_GNU_RELRO is usually the last phdr. */
1447 size_t cnt = rtld_ehdr->e_phnum;
1448 while (cnt-- > 0)
1449 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1451 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1452 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1453 break;
1456 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1457 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1458 /* Assign a module ID. Do this before loading any audit modules. */
1459 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1461 /* If we have auditing DSOs to load, do it now. */
1462 if (__builtin_expect (audit_list != NULL, 0))
1464 /* Iterate over all entries in the list. The order is important. */
1465 struct audit_ifaces *last_audit = NULL;
1466 struct audit_list *al = audit_list->next;
1468 /* Since we start using the auditing DSOs right away we need to
1469 initialize the data structures now. */
1470 tcbp = init_tls ();
1472 /* Initialize security features. We need to do it this early
1473 since otherwise the constructors of the audit libraries will
1474 use different values (especially the pointer guard) and will
1475 fail later on. */
1476 security_init ();
1480 int tls_idx = GL(dl_tls_max_dtv_idx);
1482 /* Now it is time to determine the layout of the static TLS
1483 block and allocate it for the initial thread. Note that we
1484 always allocate the static block, we never defer it even if
1485 no DF_STATIC_TLS bit is set. The reason is that we know
1486 glibc will use the static model. */
1487 struct dlmopen_args dlmargs;
1488 dlmargs.fname = al->name;
1489 dlmargs.map = NULL;
1491 const char *objname;
1492 const char *err_str = NULL;
1493 bool malloced;
1494 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1495 &dlmargs);
1496 if (__builtin_expect (err_str != NULL, 0))
1498 not_loaded:
1499 _dl_error_printf ("\
1500 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1501 al->name, err_str);
1502 if (malloced)
1503 free ((char *) err_str);
1505 else
1507 struct lookup_args largs;
1508 largs.name = "la_version";
1509 largs.map = dlmargs.map;
1511 /* Check whether the interface version matches. */
1512 (void) _dl_catch_error (&objname, &err_str, &malloced,
1513 lookup_doit, &largs);
1515 unsigned int (*laversion) (unsigned int);
1516 unsigned int lav;
1517 if (err_str == NULL
1518 && (laversion = largs.result) != NULL
1519 && (lav = laversion (LAV_CURRENT)) > 0
1520 && lav <= LAV_CURRENT)
1522 /* Allocate structure for the callback function pointers.
1523 This call can never fail. */
1524 union
1526 struct audit_ifaces ifaces;
1527 #define naudit_ifaces 8
1528 void (*fptr[naudit_ifaces]) (void);
1529 } *newp = malloc (sizeof (*newp));
1531 /* Names of the auditing interfaces. All in one
1532 long string. */
1533 static const char audit_iface_names[] =
1534 "la_activity\0"
1535 "la_objsearch\0"
1536 "la_objopen\0"
1537 "la_preinit\0"
1538 #if __ELF_NATIVE_CLASS == 32
1539 "la_symbind32\0"
1540 #elif __ELF_NATIVE_CLASS == 64
1541 "la_symbind64\0"
1542 #else
1543 # error "__ELF_NATIVE_CLASS must be defined"
1544 #endif
1545 #define STRING(s) __STRING (s)
1546 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1547 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1548 "la_objclose\0";
1549 unsigned int cnt = 0;
1550 const char *cp = audit_iface_names;
1553 largs.name = cp;
1554 (void) _dl_catch_error (&objname, &err_str, &malloced,
1555 lookup_doit, &largs);
1557 /* Store the pointer. */
1558 if (err_str == NULL && largs.result != NULL)
1560 newp->fptr[cnt] = largs.result;
1562 /* The dynamic linker link map is statically
1563 allocated, initialize the data now. */
1564 GL(dl_rtld_map).l_audit[cnt].cookie
1565 = (intptr_t) &GL(dl_rtld_map);
1567 else
1568 newp->fptr[cnt] = NULL;
1569 ++cnt;
1571 cp = (char *) rawmemchr (cp, '\0') + 1;
1573 while (*cp != '\0');
1574 assert (cnt == naudit_ifaces);
1576 /* Now append the new auditing interface to the list. */
1577 newp->ifaces.next = NULL;
1578 if (last_audit == NULL)
1579 last_audit = GLRO(dl_audit) = &newp->ifaces;
1580 else
1581 last_audit = last_audit->next = &newp->ifaces;
1582 ++GLRO(dl_naudit);
1584 /* Mark the DSO as being used for auditing. */
1585 dlmargs.map->l_auditing = 1;
1587 else
1589 /* We cannot use the DSO, it does not have the
1590 appropriate interfaces or it expects something
1591 more recent. */
1592 #ifndef NDEBUG
1593 Lmid_t ns = dlmargs.map->l_ns;
1594 #endif
1595 _dl_close (dlmargs.map);
1597 /* Make sure the namespace has been cleared entirely. */
1598 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1599 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1601 GL(dl_tls_max_dtv_idx) = tls_idx;
1602 goto not_loaded;
1606 al = al->next;
1608 while (al != audit_list->next);
1610 /* If we have any auditing modules, announce that we already
1611 have two objects loaded. */
1612 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1614 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1616 for (unsigned int outer = 0; outer < 2; ++outer)
1618 struct audit_ifaces *afct = GLRO(dl_audit);
1619 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1621 if (afct->objopen != NULL)
1623 ls[outer]->l_audit[cnt].bindflags
1624 = afct->objopen (ls[outer], LM_ID_BASE,
1625 &ls[outer]->l_audit[cnt].cookie);
1627 ls[outer]->l_audit_any_plt
1628 |= ls[outer]->l_audit[cnt].bindflags != 0;
1631 afct = afct->next;
1637 /* Set up debugging before the debugger is notified for the first time. */
1638 #ifdef ELF_MACHINE_DEBUG_SETUP
1639 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1640 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1641 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1642 #else
1643 if (main_map->l_info[DT_DEBUG] != NULL)
1644 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1645 with the run-time address of the r_debug structure */
1646 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1648 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1649 case you run gdb on the dynamic linker directly. */
1650 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1651 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1652 #endif
1654 /* We start adding objects. */
1655 r->r_state = RT_ADD;
1656 _dl_debug_state ();
1658 /* Auditing checkpoint: we are ready to signal that the initial map
1659 is being constructed. */
1660 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1662 struct audit_ifaces *afct = GLRO(dl_audit);
1663 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1665 if (afct->activity != NULL)
1666 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1668 afct = afct->next;
1672 /* We have two ways to specify objects to preload: via environment
1673 variable and via the file /etc/ld.so.preload. The latter can also
1674 be used when security is enabled. */
1675 assert (*first_preload == NULL);
1676 struct link_map **preloads = NULL;
1677 unsigned int npreloads = 0;
1679 if (__builtin_expect (preloadlist != NULL, 0))
1681 /* The LD_PRELOAD environment variable gives list of libraries
1682 separated by white space or colons that are loaded before the
1683 executable's dependencies and prepended to the global scope
1684 list. If the binary is running setuid all elements
1685 containing a '/' are ignored since it is insecure. */
1686 char *list = strdupa (preloadlist);
1687 char *p;
1689 HP_TIMING_NOW (start);
1691 /* Prevent optimizing strsep. Speed is not important here. */
1692 while ((p = (strsep) (&list, " :")) != NULL)
1693 if (p[0] != '\0'
1694 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1695 || strchr (p, '/') == NULL))
1696 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1698 HP_TIMING_NOW (stop);
1699 HP_TIMING_DIFF (diff, start, stop);
1700 HP_TIMING_ACCUM_NT (load_time, diff);
1703 /* There usually is no ld.so.preload file, it should only be used
1704 for emergencies and testing. So the open call etc should usually
1705 fail. Using access() on a non-existing file is faster than using
1706 open(). So we do this first. If it succeeds we do almost twice
1707 the work but this does not matter, since it is not for production
1708 use. */
1709 static const char preload_file[] = "/etc/ld.so.preload";
1710 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1712 /* Read the contents of the file. */
1713 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1714 PROT_READ | PROT_WRITE);
1715 if (__builtin_expect (file != MAP_FAILED, 0))
1717 /* Parse the file. It contains names of libraries to be loaded,
1718 separated by white spaces or `:'. It may also contain
1719 comments introduced by `#'. */
1720 char *problem;
1721 char *runp;
1722 size_t rest;
1724 /* Eliminate comments. */
1725 runp = file;
1726 rest = file_size;
1727 while (rest > 0)
1729 char *comment = memchr (runp, '#', rest);
1730 if (comment == NULL)
1731 break;
1733 rest -= comment - runp;
1735 *comment = ' ';
1736 while (--rest > 0 && *++comment != '\n');
1739 /* We have one problematic case: if we have a name at the end of
1740 the file without a trailing terminating characters, we cannot
1741 place the \0. Handle the case separately. */
1742 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1743 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1745 problem = &file[file_size];
1746 while (problem > file && problem[-1] != ' '
1747 && problem[-1] != '\t'
1748 && problem[-1] != '\n' && problem[-1] != ':')
1749 --problem;
1751 if (problem > file)
1752 problem[-1] = '\0';
1754 else
1756 problem = NULL;
1757 file[file_size - 1] = '\0';
1760 HP_TIMING_NOW (start);
1762 if (file != problem)
1764 char *p;
1765 runp = file;
1766 while ((p = strsep (&runp, ": \t\n")) != NULL)
1767 if (p[0] != '\0')
1768 npreloads += do_preload (p, main_map, preload_file);
1771 if (problem != NULL)
1773 char *p = strndupa (problem, file_size - (problem - file));
1775 npreloads += do_preload (p, main_map, preload_file);
1778 HP_TIMING_NOW (stop);
1779 HP_TIMING_DIFF (diff, start, stop);
1780 HP_TIMING_ACCUM_NT (load_time, diff);
1782 /* We don't need the file anymore. */
1783 __munmap (file, file_size);
1787 if (__builtin_expect (*first_preload != NULL, 0))
1789 /* Set up PRELOADS with a vector of the preloaded libraries. */
1790 struct link_map *l = *first_preload;
1791 preloads = __alloca (npreloads * sizeof preloads[0]);
1792 i = 0;
1795 preloads[i++] = l;
1796 l = l->l_next;
1797 } while (l);
1798 assert (i == npreloads);
1801 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1802 specified some libraries to load, these are inserted before the actual
1803 dependencies in the executable's searchlist for symbol resolution. */
1804 HP_TIMING_NOW (start);
1805 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1806 HP_TIMING_NOW (stop);
1807 HP_TIMING_DIFF (diff, start, stop);
1808 HP_TIMING_ACCUM_NT (load_time, diff);
1810 /* Mark all objects as being in the global scope. */
1811 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1812 main_map->l_searchlist.r_list[--i]->l_global = 1;
1814 /* Remove _dl_rtld_map from the chain. */
1815 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1816 if (GL(dl_rtld_map).l_next != NULL)
1817 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1819 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1820 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1821 break;
1823 bool rtld_multiple_ref = false;
1824 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1826 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1827 put it back in the list of visible objects. We insert it into the
1828 chain in symbol search order because gdb uses the chain's order as
1829 its symbol search order. */
1830 rtld_multiple_ref = true;
1832 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1833 if (__builtin_expect (mode, normal) == normal)
1835 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1836 ? main_map->l_searchlist.r_list[i + 1]
1837 : NULL);
1838 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1839 if (GLRO(dl_sysinfo_map) != NULL
1840 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1841 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1842 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1843 #endif
1845 else
1846 /* In trace mode there might be an invisible object (which we
1847 could not find) after the previous one in the search list.
1848 In this case it doesn't matter much where we put the
1849 interpreter object, so we just initialize the list pointer so
1850 that the assertion below holds. */
1851 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1853 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1854 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1855 if (GL(dl_rtld_map).l_next != NULL)
1857 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1858 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1862 /* Now let us see whether all libraries are available in the
1863 versions we need. */
1865 struct version_check_args args;
1866 args.doexit = mode == normal;
1867 args.dotrace = mode == trace;
1868 _dl_receive_error (print_missing_version, version_check_doit, &args);
1871 /* We do not initialize any of the TLS functionality unless any of the
1872 initial modules uses TLS. This makes dynamic loading of modules with
1873 TLS impossible, but to support it requires either eagerly doing setup
1874 now or lazily doing it later. Doing it now makes us incompatible with
1875 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1876 used. Trying to do it lazily is too hairy to try when there could be
1877 multiple threads (from a non-TLS-using libpthread). */
1878 bool was_tls_init_tp_called = tls_init_tp_called;
1879 if (tcbp == NULL)
1880 tcbp = init_tls ();
1882 if (__builtin_expect (audit_list == NULL, 1))
1883 /* Initialize security features. But only if we have not done it
1884 earlier. */
1885 security_init ();
1887 if (__builtin_expect (mode, normal) != normal)
1889 /* We were run just to list the shared libraries. It is
1890 important that we do this before real relocation, because the
1891 functions we call below for output may no longer work properly
1892 after relocation. */
1893 struct link_map *l;
1895 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1897 struct r_scope_elem *scope = &main_map->l_searchlist;
1899 for (i = 0; i < scope->r_nlist; i++)
1901 l = scope->r_list [i];
1902 if (l->l_faked)
1904 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1905 continue;
1907 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1908 GLRO(dl_trace_prelink_map) = l;
1909 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1910 l->l_libname->name[0] ? l->l_libname->name
1911 : rtld_progname ?: "<main program>",
1912 l->l_name[0] ? l->l_name
1913 : rtld_progname ?: "<main program>",
1914 (int) sizeof l->l_map_start * 2,
1915 (size_t) l->l_map_start,
1916 (int) sizeof l->l_addr * 2,
1917 (size_t) l->l_addr);
1919 if (l->l_tls_modid)
1920 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1921 (int) sizeof l->l_tls_offset * 2,
1922 (size_t) l->l_tls_offset);
1923 else
1924 _dl_printf ("\n");
1927 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1929 /* Look through the dependencies of the main executable
1930 and determine which of them is not actually
1931 required. */
1932 struct link_map *l = main_map;
1934 /* Relocate the main executable. */
1935 struct relocate_args args = { .l = l,
1936 .reloc_mode = (GLRO(dl_lazy)
1937 ? RTLD_LAZY : 0) };
1938 _dl_receive_error (print_unresolved, relocate_doit, &args);
1940 /* This loop depends on the dependencies of the executable to
1941 correspond in number and order to the DT_NEEDED entries. */
1942 ElfW(Dyn) *dyn = main_map->l_ld;
1943 bool first = true;
1944 while (dyn->d_tag != DT_NULL)
1946 if (dyn->d_tag == DT_NEEDED)
1948 l = l->l_next;
1950 if (!l->l_used)
1952 if (first)
1954 _dl_printf ("Unused direct dependencies:\n");
1955 first = false;
1958 _dl_printf ("\t%s\n", l->l_name);
1962 ++dyn;
1965 _exit (first != true);
1967 else if (! main_map->l_info[DT_NEEDED])
1968 _dl_printf ("\tstatically linked\n");
1969 else
1971 for (l = main_map->l_next; l; l = l->l_next)
1972 if (l->l_faked)
1973 /* The library was not found. */
1974 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1975 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1976 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1977 (int) sizeof l->l_map_start * 2,
1978 (size_t) l->l_map_start);
1979 else
1980 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1981 l->l_name, (int) sizeof l->l_map_start * 2,
1982 (size_t) l->l_map_start);
1985 if (__builtin_expect (mode, trace) != trace)
1986 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1988 const ElfW(Sym) *ref = NULL;
1989 ElfW(Addr) loadbase;
1990 lookup_t result;
1992 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1993 &ref, main_map->l_scope,
1994 NULL, ELF_RTYPE_CLASS_PLT,
1995 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1997 loadbase = LOOKUP_VALUE_ADDRESS (result);
1999 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
2000 INTUSE(_dl_argv)[i],
2001 (int) sizeof ref->st_value * 2,
2002 (size_t) ref->st_value,
2003 (int) sizeof loadbase * 2, (size_t) loadbase);
2005 else
2007 /* If LD_WARN is set, warn about undefined symbols. */
2008 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2010 /* We have to do symbol dependency testing. */
2011 struct relocate_args args;
2012 struct link_map *l;
2014 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2016 l = main_map;
2017 while (l->l_next != NULL)
2018 l = l->l_next;
2021 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2023 args.l = l;
2024 _dl_receive_error (print_unresolved, relocate_doit,
2025 &args);
2027 l = l->l_prev;
2029 while (l != NULL);
2031 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2032 && rtld_multiple_ref)
2034 /* Mark the link map as not yet relocated again. */
2035 GL(dl_rtld_map).l_relocated = 0;
2036 _dl_relocate_object (&GL(dl_rtld_map),
2037 main_map->l_scope, 0, 0);
2040 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2041 if (version_info)
2043 /* Print more information. This means here, print information
2044 about the versions needed. */
2045 int first = 1;
2046 struct link_map *map;
2048 for (map = main_map; map != NULL; map = map->l_next)
2050 const char *strtab;
2051 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2052 ElfW(Verneed) *ent;
2054 if (dyn == NULL)
2055 continue;
2057 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2058 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2060 if (first)
2062 _dl_printf ("\n\tVersion information:\n");
2063 first = 0;
2066 _dl_printf ("\t%s:\n",
2067 map->l_name[0] ? map->l_name : rtld_progname);
2069 while (1)
2071 ElfW(Vernaux) *aux;
2072 struct link_map *needed;
2074 needed = find_needed (strtab + ent->vn_file);
2075 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2077 while (1)
2079 const char *fname = NULL;
2081 if (needed != NULL
2082 && match_version (strtab + aux->vna_name,
2083 needed))
2084 fname = needed->l_name;
2086 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2087 strtab + ent->vn_file,
2088 strtab + aux->vna_name,
2089 aux->vna_flags & VER_FLG_WEAK
2090 ? "[WEAK] " : "",
2091 fname ?: "not found");
2093 if (aux->vna_next == 0)
2094 /* No more symbols. */
2095 break;
2097 /* Next symbol. */
2098 aux = (ElfW(Vernaux) *) ((char *) aux
2099 + aux->vna_next);
2102 if (ent->vn_next == 0)
2103 /* No more dependencies. */
2104 break;
2106 /* Next dependency. */
2107 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2113 _exit (0);
2116 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2117 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2118 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2120 ElfW(Lib) *liblist, *liblistend;
2121 struct link_map **r_list, **r_listend, *l;
2122 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2124 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2125 liblist = (ElfW(Lib) *)
2126 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2127 liblistend = (ElfW(Lib) *)
2128 ((char *) liblist +
2129 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2130 r_list = main_map->l_searchlist.r_list;
2131 r_listend = r_list + main_map->l_searchlist.r_nlist;
2133 for (; r_list < r_listend && liblist < liblistend; r_list++)
2135 l = *r_list;
2137 if (l == main_map)
2138 continue;
2140 /* If the library is not mapped where it should, fail. */
2141 if (l->l_addr)
2142 break;
2144 /* Next, check if checksum matches. */
2145 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2146 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2147 != liblist->l_checksum)
2148 break;
2150 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2151 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2152 != liblist->l_time_stamp)
2153 break;
2155 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2156 break;
2158 ++liblist;
2162 if (r_list == r_listend && liblist == liblistend)
2163 prelinked = true;
2165 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2166 _dl_debug_printf ("\nprelink checking: %s\n",
2167 prelinked ? "ok" : "failed");
2171 /* Now set up the variable which helps the assembler startup code. */
2172 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2174 /* Save the information about the original global scope list since
2175 we need it in the memory handling later. */
2176 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2178 /* Remember the last search directory added at startup, now that
2179 malloc will no longer be the one from dl-minimal.c. */
2180 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2182 if (prelinked)
2184 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2186 ElfW(Rela) *conflict, *conflictend;
2187 #ifndef HP_TIMING_NONAVAIL
2188 hp_timing_t start;
2189 hp_timing_t stop;
2190 #endif
2192 HP_TIMING_NOW (start);
2193 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2194 conflict = (ElfW(Rela) *)
2195 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2196 conflictend = (ElfW(Rela) *)
2197 ((char *) conflict
2198 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2199 _dl_resolve_conflicts (main_map, conflict, conflictend);
2200 HP_TIMING_NOW (stop);
2201 HP_TIMING_DIFF (relocate_time, start, stop);
2205 /* Mark all the objects so we know they have been already relocated. */
2206 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2208 l->l_relocated = 1;
2209 if (l->l_relro_size)
2210 _dl_protect_relro (l);
2212 /* Add object to slot information data if necessasy. */
2213 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2214 _dl_add_to_slotinfo (l);
2217 else
2219 /* Now we have all the objects loaded. Relocate them all except for
2220 the dynamic linker itself. We do this in reverse order so that copy
2221 relocs of earlier objects overwrite the data written by later
2222 objects. We do not re-relocate the dynamic linker itself in this
2223 loop because that could result in the GOT entries for functions we
2224 call being changed, and that would break us. It is safe to relocate
2225 the dynamic linker out of order because it has no copy relocs (we
2226 know that because it is self-contained). */
2228 int consider_profiling = GLRO(dl_profile) != NULL;
2229 #ifndef HP_TIMING_NONAVAIL
2230 hp_timing_t start;
2231 hp_timing_t stop;
2232 #endif
2234 /* If we are profiling we also must do lazy reloaction. */
2235 GLRO(dl_lazy) |= consider_profiling;
2237 struct link_map *l = main_map;
2238 while (l->l_next)
2239 l = l->l_next;
2241 HP_TIMING_NOW (start);
2244 /* While we are at it, help the memory handling a bit. We have to
2245 mark some data structures as allocated with the fake malloc()
2246 implementation in ld.so. */
2247 struct libname_list *lnp = l->l_libname->next;
2249 while (__builtin_expect (lnp != NULL, 0))
2251 lnp->dont_free = 1;
2252 lnp = lnp->next;
2254 l->l_free_initfini = 0;
2256 if (l != &GL(dl_rtld_map))
2257 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2258 consider_profiling);
2260 /* Add object to slot information data if necessasy. */
2261 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2262 _dl_add_to_slotinfo (l);
2264 l = l->l_prev;
2266 while (l);
2267 HP_TIMING_NOW (stop);
2269 HP_TIMING_DIFF (relocate_time, start, stop);
2271 /* Now enable profiling if needed. Like the previous call,
2272 this has to go here because the calls it makes should use the
2273 rtld versions of the functions (particularly calloc()), but it
2274 needs to have _dl_profile_map set up by the relocator. */
2275 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2276 /* We must prepare the profiling. */
2277 _dl_start_profile ();
2280 #ifndef NONTLS_INIT_TP
2281 # define NONTLS_INIT_TP do { } while (0)
2282 #endif
2284 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2285 ++GL(dl_tls_generation);
2287 /* Now that we have completed relocation, the initializer data
2288 for the TLS blocks has its final values and we can copy them
2289 into the main thread's TLS area, which we allocated above. */
2290 _dl_allocate_tls_init (tcbp);
2292 /* And finally install it for the main thread. If ld.so itself uses
2293 TLS we know the thread pointer was initialized earlier. */
2294 if (! tls_init_tp_called)
2296 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2297 if (__builtin_expect (lossage != NULL, 0))
2298 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2299 lossage);
2302 if (! prelinked && rtld_multiple_ref)
2304 /* There was an explicit ref to the dynamic linker as a shared lib.
2305 Re-relocate ourselves with user-controlled symbol definitions.
2307 We must do this after TLS initialization in case after this
2308 re-relocation, we might call a user-supplied function
2309 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2311 #ifndef HP_TIMING_NONAVAIL
2312 hp_timing_t start;
2313 hp_timing_t stop;
2314 hp_timing_t add;
2315 #endif
2317 HP_TIMING_NOW (start);
2318 /* Mark the link map as not yet relocated again. */
2319 GL(dl_rtld_map).l_relocated = 0;
2320 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2321 HP_TIMING_NOW (stop);
2322 HP_TIMING_DIFF (add, start, stop);
2323 HP_TIMING_ACCUM_NT (relocate_time, add);
2326 /* Do any necessary cleanups for the startup OS interface code.
2327 We do these now so that no calls are made after rtld re-relocation
2328 which might be resolved to different functions than we expect.
2329 We cannot do this before relocating the other objects because
2330 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2331 _dl_sysdep_start_cleanup ();
2333 #ifdef SHARED
2334 /* Auditing checkpoint: we have added all objects. */
2335 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2337 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2338 /* Do not call the functions for any auditing object. */
2339 if (head->l_auditing == 0)
2341 struct audit_ifaces *afct = GLRO(dl_audit);
2342 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2344 if (afct->activity != NULL)
2345 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2347 afct = afct->next;
2351 #endif
2353 /* Notify the debugger all new objects are now ready to go. We must re-get
2354 the address since by now the variable might be in another object. */
2355 r = _dl_debug_initialize (0, LM_ID_BASE);
2356 r->r_state = RT_CONSISTENT;
2357 _dl_debug_state ();
2359 #ifndef MAP_COPY
2360 /* We must munmap() the cache file. */
2361 _dl_unload_cache ();
2362 #endif
2364 /* Once we return, _dl_sysdep_start will invoke
2365 the DT_INIT functions and then *USER_ENTRY. */
2368 /* This is a little helper function for resolving symbols while
2369 tracing the binary. */
2370 static void
2371 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2372 const char *errstring)
2374 if (objname[0] == '\0')
2375 objname = rtld_progname ?: "<main program>";
2376 _dl_error_printf ("%s (%s)\n", errstring, objname);
2379 /* This is a little helper function for resolving symbols while
2380 tracing the binary. */
2381 static void
2382 print_missing_version (int errcode __attribute__ ((unused)),
2383 const char *objname, const char *errstring)
2385 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2386 objname, errstring);
2389 /* Nonzero if any of the debugging options is enabled. */
2390 static int any_debug attribute_relro;
2392 /* Process the string given as the parameter which explains which debugging
2393 options are enabled. */
2394 static void
2395 process_dl_debug (const char *dl_debug)
2397 /* When adding new entries make sure that the maximal length of a name
2398 is correctly handled in the LD_DEBUG_HELP code below. */
2399 static const struct
2401 unsigned char len;
2402 const char name[10];
2403 const char helptext[41];
2404 unsigned short int mask;
2405 } debopts[] =
2407 #define LEN_AND_STR(str) sizeof (str) - 1, str
2408 { LEN_AND_STR ("libs"), "display library search paths",
2409 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2410 { LEN_AND_STR ("reloc"), "display relocation processing",
2411 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2412 { LEN_AND_STR ("files"), "display progress for input file",
2413 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2414 { LEN_AND_STR ("symbols"), "display symbol table processing",
2415 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2416 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2417 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2418 { LEN_AND_STR ("versions"), "display version dependencies",
2419 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2420 { LEN_AND_STR ("all"), "all previous options combined",
2421 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2422 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2423 { LEN_AND_STR ("statistics"), "display relocation statistics",
2424 DL_DEBUG_STATISTICS },
2425 { LEN_AND_STR ("unused"), "determined unused DSOs",
2426 DL_DEBUG_UNUSED },
2427 { LEN_AND_STR ("help"), "display this help message and exit",
2428 DL_DEBUG_HELP },
2430 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2432 /* Skip separating white spaces and commas. */
2433 while (*dl_debug != '\0')
2435 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2437 size_t cnt;
2438 size_t len = 1;
2440 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2441 && dl_debug[len] != ',' && dl_debug[len] != ':')
2442 ++len;
2444 for (cnt = 0; cnt < ndebopts; ++cnt)
2445 if (debopts[cnt].len == len
2446 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2448 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2449 any_debug = 1;
2450 break;
2453 if (cnt == ndebopts)
2455 /* Display a warning and skip everything until next
2456 separator. */
2457 char *copy = strndupa (dl_debug, len);
2458 _dl_error_printf ("\
2459 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2462 dl_debug += len;
2463 continue;
2466 ++dl_debug;
2469 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2471 size_t cnt;
2473 _dl_printf ("\
2474 Valid options for the LD_DEBUG environment variable are:\n\n");
2476 for (cnt = 0; cnt < ndebopts; ++cnt)
2477 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2478 " " + debopts[cnt].len - 3,
2479 debopts[cnt].helptext);
2481 _dl_printf ("\n\
2482 To direct the debugging output into a file instead of standard output\n\
2483 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2484 _exit (0);
2488 static void
2489 process_dl_audit (char *str)
2491 /* The parameter is a colon separated list of DSO names. */
2492 char *p;
2494 while ((p = (strsep) (&str, ":")) != NULL)
2495 if (p[0] != '\0'
2496 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2497 || strchr (p, '/') == NULL))
2499 /* This is using the local malloc, not the system malloc. The
2500 memory can never be freed. */
2501 struct audit_list *newp = malloc (sizeof (*newp));
2502 newp->name = p;
2504 if (audit_list == NULL)
2505 audit_list = newp->next = newp;
2506 else
2508 newp->next = audit_list->next;
2509 audit_list = audit_list->next = newp;
2514 /* Process all environments variables the dynamic linker must recognize.
2515 Since all of them start with `LD_' we are a bit smarter while finding
2516 all the entries. */
2517 extern char **_environ attribute_hidden;
2520 static void
2521 process_envvars (enum mode *modep)
2523 char **runp = _environ;
2524 char *envline;
2525 enum mode mode = normal;
2526 char *debug_output = NULL;
2528 /* This is the default place for profiling data file. */
2529 GLRO(dl_profile_output)
2530 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2532 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2534 size_t len = 0;
2536 while (envline[len] != '\0' && envline[len] != '=')
2537 ++len;
2539 if (envline[len] != '=')
2540 /* This is a "LD_" variable at the end of the string without
2541 a '=' character. Ignore it since otherwise we will access
2542 invalid memory below. */
2543 continue;
2545 switch (len)
2547 case 4:
2548 /* Warning level, verbose or not. */
2549 if (memcmp (envline, "WARN", 4) == 0)
2550 GLRO(dl_verbose) = envline[5] != '\0';
2551 break;
2553 case 5:
2554 /* Debugging of the dynamic linker? */
2555 if (memcmp (envline, "DEBUG", 5) == 0)
2557 process_dl_debug (&envline[6]);
2558 break;
2560 if (memcmp (envline, "AUDIT", 5) == 0)
2561 process_dl_audit (&envline[6]);
2562 break;
2564 case 7:
2565 /* Print information about versions. */
2566 if (memcmp (envline, "VERBOSE", 7) == 0)
2568 version_info = envline[8] != '\0';
2569 break;
2572 /* List of objects to be preloaded. */
2573 if (memcmp (envline, "PRELOAD", 7) == 0)
2575 preloadlist = &envline[8];
2576 break;
2579 /* Which shared object shall be profiled. */
2580 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2581 GLRO(dl_profile) = &envline[8];
2582 break;
2584 case 8:
2585 /* Do we bind early? */
2586 if (memcmp (envline, "BIND_NOW", 8) == 0)
2588 GLRO(dl_lazy) = envline[9] == '\0';
2589 break;
2591 if (memcmp (envline, "BIND_NOT", 8) == 0)
2592 GLRO(dl_bind_not) = envline[9] != '\0';
2593 break;
2595 case 9:
2596 /* Test whether we want to see the content of the auxiliary
2597 array passed up from the kernel. */
2598 if (!INTUSE(__libc_enable_secure)
2599 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2600 _dl_show_auxv ();
2601 break;
2603 case 10:
2604 /* Mask for the important hardware capabilities. */
2605 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2606 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2607 0, 0);
2608 break;
2610 case 11:
2611 /* Path where the binary is found. */
2612 if (!INTUSE(__libc_enable_secure)
2613 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2614 GLRO(dl_origin_path) = &envline[12];
2615 break;
2617 case 12:
2618 /* The library search path. */
2619 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2621 library_path = &envline[13];
2622 break;
2625 /* Where to place the profiling data file. */
2626 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2628 debug_output = &envline[13];
2629 break;
2632 if (!INTUSE(__libc_enable_secure)
2633 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2634 GLRO(dl_dynamic_weak) = 1;
2635 break;
2637 case 13:
2638 /* We might have some extra environment variable with length 13
2639 to handle. */
2640 #ifdef EXTRA_LD_ENVVARS_13
2641 EXTRA_LD_ENVVARS_13
2642 #endif
2643 if (!INTUSE(__libc_enable_secure)
2644 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2646 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2647 break;
2650 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2651 GLRO(dl_pointer_guard) = envline[14] != '0';
2652 break;
2654 case 14:
2655 /* Where to place the profiling data file. */
2656 if (!INTUSE(__libc_enable_secure)
2657 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2658 && envline[15] != '\0')
2659 GLRO(dl_profile_output) = &envline[15];
2660 break;
2662 case 16:
2663 /* The mode of the dynamic linker can be set. */
2664 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2666 mode = trace;
2667 GLRO(dl_verbose) = 1;
2668 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2669 GLRO(dl_trace_prelink) = &envline[17];
2671 break;
2673 case 20:
2674 /* The mode of the dynamic linker can be set. */
2675 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2676 mode = trace;
2677 break;
2679 /* We might have some extra environment variable to handle. This
2680 is tricky due to the pre-processing of the length of the name
2681 in the switch statement here. The code here assumes that added
2682 environment variables have a different length. */
2683 #ifdef EXTRA_LD_ENVVARS
2684 EXTRA_LD_ENVVARS
2685 #endif
2689 /* The caller wants this information. */
2690 *modep = mode;
2692 /* Extra security for SUID binaries. Remove all dangerous environment
2693 variables. */
2694 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2696 static const char unsecure_envvars[] =
2697 #ifdef EXTRA_UNSECURE_ENVVARS
2698 EXTRA_UNSECURE_ENVVARS
2699 #endif
2700 UNSECURE_ENVVARS;
2701 const char *nextp;
2703 nextp = unsecure_envvars;
2706 unsetenv (nextp);
2707 /* We could use rawmemchr but this need not be fast. */
2708 nextp = (char *) (strchr) (nextp, '\0') + 1;
2710 while (*nextp != '\0');
2712 if (__access ("/etc/suid-debug", F_OK) != 0)
2714 unsetenv ("MALLOC_CHECK_");
2715 GLRO(dl_debug_mask) = 0;
2718 if (mode != normal)
2719 _exit (5);
2721 /* If we have to run the dynamic linker in debugging mode and the
2722 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2723 messages to this file. */
2724 else if (any_debug && debug_output != NULL)
2726 #ifdef O_NOFOLLOW
2727 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2728 #else
2729 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2730 #endif
2731 size_t name_len = strlen (debug_output);
2732 char buf[name_len + 12];
2733 char *startp;
2735 buf[name_len + 11] = '\0';
2736 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2737 *--startp = '.';
2738 startp = memcpy (startp - name_len, debug_output, name_len);
2740 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2741 if (GLRO(dl_debug_fd) == -1)
2742 /* We use standard output if opening the file failed. */
2743 GLRO(dl_debug_fd) = STDOUT_FILENO;
2748 /* Print the various times we collected. */
2749 static void
2750 __attribute ((noinline))
2751 print_statistics (hp_timing_t *rtld_total_timep)
2753 #ifndef HP_TIMING_NONAVAIL
2754 char buf[200];
2755 char *cp;
2756 char *wp;
2758 /* Total time rtld used. */
2759 if (HP_TIMING_AVAIL)
2761 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2762 _dl_debug_printf ("\nruntime linker statistics:\n"
2763 " total startup time in dynamic loader: %s\n", buf);
2765 /* Print relocation statistics. */
2766 char pbuf[30];
2767 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2768 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2769 pbuf + sizeof (pbuf), 10, 0);
2770 wp = pbuf;
2771 switch (pbuf + sizeof (pbuf) - cp)
2773 case 3:
2774 *wp++ = *cp++;
2775 case 2:
2776 *wp++ = *cp++;
2777 case 1:
2778 *wp++ = '.';
2779 *wp++ = *cp++;
2781 *wp = '\0';
2782 _dl_debug_printf ("\
2783 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2785 #endif
2787 unsigned long int num_relative_relocations = 0;
2788 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2790 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2791 continue;
2793 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2795 for (unsigned int i = 0; i < scope->r_nlist; i++)
2797 struct link_map *l = scope->r_list [i];
2799 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2800 num_relative_relocations
2801 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2802 #ifndef ELF_MACHINE_REL_RELATIVE
2803 /* Relative relocations are processed on these architectures if
2804 library is loaded to different address than p_vaddr or
2805 if not prelinked. */
2806 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2807 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2808 #else
2809 /* On e.g. IA-64 or Alpha, relative relocations are processed
2810 only if library is loaded to different address than p_vaddr. */
2811 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2812 #endif
2813 num_relative_relocations
2814 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2818 _dl_debug_printf (" number of relocations: %lu\n"
2819 " number of relocations from cache: %lu\n"
2820 " number of relative relocations: %lu\n",
2821 GL(dl_num_relocations),
2822 GL(dl_num_cache_relocations),
2823 num_relative_relocations);
2825 #ifndef HP_TIMING_NONAVAIL
2826 /* Time spend while loading the object and the dependencies. */
2827 if (HP_TIMING_AVAIL)
2829 char pbuf[30];
2830 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2831 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2832 pbuf + sizeof (pbuf), 10, 0);
2833 wp = pbuf;
2834 switch (pbuf + sizeof (pbuf) - cp)
2836 case 3:
2837 *wp++ = *cp++;
2838 case 2:
2839 *wp++ = *cp++;
2840 case 1:
2841 *wp++ = '.';
2842 *wp++ = *cp++;
2844 *wp = '\0';
2845 _dl_debug_printf ("\
2846 time needed to load objects: %s (%s%%)\n",
2847 buf, pbuf);
2849 #endif