More regex memory leak fixes and testcases
[glibc.git] / elf / rtld.c
blob5b7eabcb85df7ad140c5d4cb74fe62e9afde700c
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2006, 2007, 2008, 2009 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h>
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
44 #include <assert.h>
46 /* Avoid PLT use for our local calls at startup. */
47 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
49 /* GCC has mental blocks about _exit. */
50 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
51 #define _exit exit_internal
53 /* Helper function to handle errors while resolving symbols. */
54 static void print_unresolved (int errcode, const char *objname,
55 const char *errsting);
57 /* Helper function to handle errors when a version is missing. */
58 static void print_missing_version (int errcode, const char *objname,
59 const char *errsting);
61 /* Print the various times we collected. */
62 static void print_statistics (hp_timing_t *total_timep);
64 /* Add audit objects. */
65 static void process_dl_audit (char *str);
67 /* This is a list of all the modes the dynamic loader can be in. */
68 enum mode { normal, list, verify, trace };
70 /* Process all environments variables the dynamic linker must recognize.
71 Since all of them start with `LD_' we are a bit smarter while finding
72 all the entries. */
73 static void process_envvars (enum mode *modep);
75 #ifdef DL_ARGV_NOT_RELRO
76 int _dl_argc attribute_hidden;
77 char **_dl_argv = NULL;
78 /* Nonzero if we were run directly. */
79 unsigned int _dl_skip_args attribute_hidden;
80 #else
81 int _dl_argc attribute_relro attribute_hidden;
82 char **_dl_argv attribute_relro = NULL;
83 unsigned int _dl_skip_args attribute_relro attribute_hidden;
84 #endif
85 INTDEF(_dl_argv)
87 #ifndef THREAD_SET_STACK_GUARD
88 /* Only exported for architectures that don't store the stack guard canary
89 in thread local area. */
90 uintptr_t __stack_chk_guard attribute_relro;
91 #endif
93 /* Only exported for architectures that don't store the pointer guard
94 value in thread local area. */
95 uintptr_t __pointer_chk_guard_local
96 attribute_relro attribute_hidden __attribute__ ((nocommon));
97 #ifndef THREAD_SET_POINTER_GUARD
98 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
99 #endif
102 /* List of auditing DSOs. */
103 static struct audit_list
105 const char *name;
106 struct audit_list *next;
107 } *audit_list;
109 #ifndef HAVE_INLINED_SYSCALLS
110 /* Set nonzero during loading and initialization of executable and
111 libraries, cleared before the executable's entry point runs. This
112 must not be initialized to nonzero, because the unused dynamic
113 linker loaded in for libc.so's "ld.so.1" dep will provide the
114 definition seen by libc.so's initializer; that value must be zero,
115 and will be since that dynamic linker's _dl_start and dl_main will
116 never be called. */
117 int _dl_starting_up = 0;
118 INTVARDEF(_dl_starting_up)
119 #endif
121 /* This is the structure which defines all variables global to ld.so
122 (except those which cannot be added for some reason). */
123 struct rtld_global _rtld_global =
125 /* Default presumption without further information is executable stack. */
126 ._dl_stack_flags = PF_R|PF_W|PF_X,
127 #ifdef _LIBC_REENTRANT
128 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
129 #endif
130 ._dl_nns = 1,
131 ._dl_ns =
133 [LM_ID_BASE] = { ._ns_unique_sym_table
134 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
137 /* If we would use strong_alias here the compiler would see a
138 non-hidden definition. This would undo the effect of the previous
139 declaration. So spell out was strong_alias does plus add the
140 visibility attribute. */
141 extern struct rtld_global _rtld_local
142 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
145 /* This variable is similar to _rtld_local, but all values are
146 read-only after relocation. */
147 struct rtld_global_ro _rtld_global_ro attribute_relro =
149 /* Get architecture specific initializer. */
150 #include <dl-procinfo.c>
151 #ifdef NEED_DL_SYSINFO
152 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
153 #endif
154 ._dl_debug_fd = STDERR_FILENO,
155 ._dl_use_load_bias = -2,
156 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
157 ._dl_hwcap_mask = HWCAP_IMPORTANT,
158 ._dl_lazy = 1,
159 ._dl_fpu_control = _FPU_DEFAULT,
160 ._dl_pointer_guard = 1,
162 /* Function pointers. */
163 ._dl_debug_printf = _dl_debug_printf,
164 ._dl_catch_error = _dl_catch_error,
165 ._dl_signal_error = _dl_signal_error,
166 ._dl_mcount = _dl_mcount_internal,
167 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
168 ._dl_check_caller = _dl_check_caller,
169 ._dl_open = _dl_open,
170 ._dl_close = _dl_close,
171 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
172 #ifdef HAVE_DL_DISCOVER_OSVERSION
173 ._dl_discover_osversion = _dl_discover_osversion
174 #endif
176 /* If we would use strong_alias here the compiler would see a
177 non-hidden definition. This would undo the effect of the previous
178 declaration. So spell out was strong_alias does plus add the
179 visibility attribute. */
180 extern struct rtld_global_ro _rtld_local_ro
181 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
184 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
185 ElfW(Addr) *user_entry);
187 /* These two variables cannot be moved into .data.rel.ro. */
188 static struct libname_list _dl_rtld_libname;
189 static struct libname_list _dl_rtld_libname2;
191 /* We expect less than a second for relocation. */
192 #ifdef HP_SMALL_TIMING_AVAIL
193 # undef HP_TIMING_AVAIL
194 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
195 #endif
197 /* Variable for statistics. */
198 #ifndef HP_TIMING_NONAVAIL
199 static hp_timing_t relocate_time;
200 static hp_timing_t load_time attribute_relro;
201 static hp_timing_t start_time attribute_relro;
202 #endif
204 /* Additional definitions needed by TLS initialization. */
205 #ifdef TLS_INIT_HELPER
206 TLS_INIT_HELPER
207 #endif
209 /* Helper function for syscall implementation. */
210 #ifdef DL_SYSINFO_IMPLEMENTATION
211 DL_SYSINFO_IMPLEMENTATION
212 #endif
214 /* Before ld.so is relocated we must not access variables which need
215 relocations. This means variables which are exported. Variables
216 declared as static are fine. If we can mark a variable hidden this
217 is fine, too. The latter is important here. We can avoid setting
218 up a temporary link map for ld.so if we can mark _rtld_global as
219 hidden. */
220 #ifdef PI_STATIC_AND_HIDDEN
221 # define DONT_USE_BOOTSTRAP_MAP 1
222 #endif
224 #ifdef DONT_USE_BOOTSTRAP_MAP
225 static ElfW(Addr) _dl_start_final (void *arg);
226 #else
227 struct dl_start_final_info
229 struct link_map l;
230 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
231 hp_timing_t start_time;
232 #endif
234 static ElfW(Addr) _dl_start_final (void *arg,
235 struct dl_start_final_info *info);
236 #endif
238 /* These defined magically in the linker script. */
239 extern char _begin[] attribute_hidden;
240 extern char _etext[] attribute_hidden;
241 extern char _end[] attribute_hidden;
244 #ifdef RTLD_START
245 RTLD_START
246 #else
247 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
248 #endif
250 #ifndef VALIDX
251 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
252 + DT_EXTRANUM + DT_VALTAGIDX (tag))
253 #endif
254 #ifndef ADDRIDX
255 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
256 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
257 #endif
259 /* This is the second half of _dl_start (below). It can be inlined safely
260 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
261 references. When the tools don't permit us to avoid using a GOT entry
262 for _dl_rtld_global (no attribute_hidden support), we must make sure
263 this function is not inlined (see below). */
265 #ifdef DONT_USE_BOOTSTRAP_MAP
266 static inline ElfW(Addr) __attribute__ ((always_inline))
267 _dl_start_final (void *arg)
268 #else
269 static ElfW(Addr) __attribute__ ((noinline))
270 _dl_start_final (void *arg, struct dl_start_final_info *info)
271 #endif
273 ElfW(Addr) start_addr;
275 if (HP_TIMING_AVAIL)
277 /* If it hasn't happen yet record the startup time. */
278 if (! HP_TIMING_INLINE)
279 HP_TIMING_NOW (start_time);
280 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
281 else
282 start_time = info->start_time;
283 #endif
285 /* Initialize the timing functions. */
286 HP_TIMING_DIFF_INIT ();
289 /* Transfer data about ourselves to the permanent link_map structure. */
290 #ifndef DONT_USE_BOOTSTRAP_MAP
291 GL(dl_rtld_map).l_addr = info->l.l_addr;
292 GL(dl_rtld_map).l_ld = info->l.l_ld;
293 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
294 sizeof GL(dl_rtld_map).l_info);
295 GL(dl_rtld_map).l_mach = info->l.l_mach;
296 GL(dl_rtld_map).l_relocated = 1;
297 #endif
298 _dl_setup_hash (&GL(dl_rtld_map));
299 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
300 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
301 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
302 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
303 /* Copy the TLS related data if necessary. */
304 #ifndef DONT_USE_BOOTSTRAP_MAP
305 # if USE___THREAD
306 assert (info->l.l_tls_modid != 0);
307 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
308 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
309 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
310 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
311 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
312 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
313 GL(dl_rtld_map).l_tls_modid = 1;
314 # else
315 # if NO_TLS_OFFSET != 0
316 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
317 # endif
318 # endif
320 #endif
322 #if HP_TIMING_AVAIL
323 HP_TIMING_NOW (GL(dl_cpuclock_offset));
324 #endif
326 /* Initialize the stack end variable. */
327 __libc_stack_end = __builtin_frame_address (0);
329 /* Call the OS-dependent function to set up life so we can do things like
330 file access. It will call `dl_main' (below) to do all the real work
331 of the dynamic linker, and then unwind our frame and run the user
332 entry point on the same stack we entered on. */
333 start_addr = _dl_sysdep_start (arg, &dl_main);
335 #ifndef HP_TIMING_NONAVAIL
336 hp_timing_t rtld_total_time;
337 if (HP_TIMING_AVAIL)
339 hp_timing_t end_time;
341 /* Get the current time. */
342 HP_TIMING_NOW (end_time);
344 /* Compute the difference. */
345 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
347 #endif
349 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
351 #ifndef HP_TIMING_NONAVAIL
352 print_statistics (&rtld_total_time);
353 #else
354 print_statistics (NULL);
355 #endif
358 return start_addr;
361 static ElfW(Addr) __attribute_used__ internal_function
362 _dl_start (void *arg)
364 #ifdef DONT_USE_BOOTSTRAP_MAP
365 # define bootstrap_map GL(dl_rtld_map)
366 #else
367 struct dl_start_final_info info;
368 # define bootstrap_map info.l
369 #endif
371 /* This #define produces dynamic linking inline functions for
372 bootstrap relocation instead of general-purpose relocation.
373 Since ld.so must not have any undefined symbols the result
374 is trivial: always the map of ld.so itself. */
375 #define RTLD_BOOTSTRAP
376 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
377 #include "dynamic-link.h"
379 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
380 #ifdef DONT_USE_BOOTSTRAP_MAP
381 HP_TIMING_NOW (start_time);
382 #else
383 HP_TIMING_NOW (info.start_time);
384 #endif
386 /* Partly clean the `bootstrap_map' structure up. Don't use
387 `memset' since it might not be built in or inlined and we cannot
388 make function calls at this point. Use '__builtin_memset' if we
389 know it is available. We do not have to clear the memory if we
390 do not have to use the temporary bootstrap_map. Global variables
391 are initialized to zero by default. */
392 #ifndef DONT_USE_BOOTSTRAP_MAP
393 # ifdef HAVE_BUILTIN_MEMSET
394 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
395 # else
396 for (size_t cnt = 0;
397 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
398 ++cnt)
399 bootstrap_map.l_info[cnt] = 0;
400 # endif
401 # if USE___THREAD
402 bootstrap_map.l_tls_modid = 0;
403 # endif
404 #endif
406 /* Figure out the run-time load address of the dynamic linker itself. */
407 bootstrap_map.l_addr = elf_machine_load_address ();
409 /* Read our own dynamic section and fill in the info array. */
410 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
411 elf_get_dynamic_info (&bootstrap_map, NULL);
413 #if NO_TLS_OFFSET != 0
414 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
415 #endif
417 /* Get the dynamic linker's own program header. First we need the ELF
418 file header. The `_begin' symbol created by the linker script points
419 to it. When we have something like GOTOFF relocs, we can use a plain
420 reference to find the runtime address. Without that, we have to rely
421 on the `l_addr' value, which is not the value we want when prelinked. */
422 #if USE___THREAD
423 dtv_t initdtv[3];
424 ElfW(Ehdr) *ehdr
425 # ifdef DONT_USE_BOOTSTRAP_MAP
426 = (ElfW(Ehdr) *) &_begin;
427 # else
428 # error This will not work with prelink.
429 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
430 # endif
431 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
432 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
433 while (cnt-- > 0)
434 if (phdr[cnt].p_type == PT_TLS)
436 void *tlsblock;
437 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
438 char *p;
440 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
441 bootstrap_map.l_tls_align = phdr[cnt].p_align;
442 if (phdr[cnt].p_align == 0)
443 bootstrap_map.l_tls_firstbyte_offset = 0;
444 else
445 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
446 & (phdr[cnt].p_align - 1));
447 assert (bootstrap_map.l_tls_blocksize != 0);
448 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
449 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
450 + phdr[cnt].p_vaddr);
452 /* We can now allocate the initial TLS block. This can happen
453 on the stack. We'll get the final memory later when we
454 know all about the various objects loaded at startup
455 time. */
456 # if TLS_TCB_AT_TP
457 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
458 TLS_INIT_TCB_ALIGN)
459 + TLS_INIT_TCB_SIZE
460 + max_align);
461 # elif TLS_DTV_AT_TP
462 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
463 bootstrap_map.l_tls_align)
464 + bootstrap_map.l_tls_blocksize
465 + max_align);
466 # else
467 /* In case a model with a different layout for the TCB and DTV
468 is defined add another #elif here and in the following #ifs. */
469 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
470 # endif
471 /* Align the TLS block. */
472 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
473 & ~(max_align - 1));
475 /* Initialize the dtv. [0] is the length, [1] the generation
476 counter. */
477 initdtv[0].counter = 1;
478 initdtv[1].counter = 0;
480 /* Initialize the TLS block. */
481 # if TLS_TCB_AT_TP
482 initdtv[2].pointer = tlsblock;
483 # elif TLS_DTV_AT_TP
484 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
485 bootstrap_map.l_tls_align);
486 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
487 # else
488 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
489 # endif
490 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
491 bootstrap_map.l_tls_initimage_size);
492 # ifdef HAVE_BUILTIN_MEMSET
493 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
494 - bootstrap_map.l_tls_initimage_size));
495 # else
497 size_t remaining = (bootstrap_map.l_tls_blocksize
498 - bootstrap_map.l_tls_initimage_size);
499 while (remaining-- > 0)
500 *p++ = '\0';
502 # endif
504 /* Install the pointer to the dtv. */
506 /* Initialize the thread pointer. */
507 # if TLS_TCB_AT_TP
508 bootstrap_map.l_tls_offset
509 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
511 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
512 initdtv);
514 const char *lossage = TLS_INIT_TP ((char *) tlsblock
515 + bootstrap_map.l_tls_offset, 0);
516 # elif TLS_DTV_AT_TP
517 INSTALL_DTV (tlsblock, initdtv);
518 const char *lossage = TLS_INIT_TP (tlsblock, 0);
519 # else
520 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
521 # endif
522 if (__builtin_expect (lossage != NULL, 0))
523 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
524 lossage);
526 /* So far this is module number one. */
527 bootstrap_map.l_tls_modid = 1;
529 /* There can only be one PT_TLS entry. */
530 break;
532 #endif /* USE___THREAD */
534 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
535 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
536 #endif
538 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
540 /* Relocate ourselves so we can do normal function calls and
541 data access using the global offset table. */
543 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
545 bootstrap_map.l_relocated = 1;
547 /* Please note that we don't allow profiling of this object and
548 therefore need not test whether we have to allocate the array
549 for the relocation results (as done in dl-reloc.c). */
551 /* Now life is sane; we can call functions and access global data.
552 Set up to use the operating system facilities, and find out from
553 the operating system's program loader where to find the program
554 header table in core. Put the rest of _dl_start into a separate
555 function, that way the compiler cannot put accesses to the GOT
556 before ELF_DYNAMIC_RELOCATE. */
558 #ifdef DONT_USE_BOOTSTRAP_MAP
559 ElfW(Addr) entry = _dl_start_final (arg);
560 #else
561 ElfW(Addr) entry = _dl_start_final (arg, &info);
562 #endif
564 #ifndef ELF_MACHINE_START_ADDRESS
565 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
566 #endif
568 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
574 /* Now life is peachy; we can do all normal operations.
575 On to the real work. */
577 /* Some helper functions. */
579 /* Arguments to relocate_doit. */
580 struct relocate_args
582 struct link_map *l;
583 int reloc_mode;
586 struct map_args
588 /* Argument to map_doit. */
589 char *str;
590 struct link_map *loader;
591 int mode;
592 /* Return value of map_doit. */
593 struct link_map *map;
596 struct dlmopen_args
598 const char *fname;
599 struct link_map *map;
602 struct lookup_args
604 const char *name;
605 struct link_map *map;
606 void *result;
609 /* Arguments to version_check_doit. */
610 struct version_check_args
612 int doexit;
613 int dotrace;
616 static void
617 relocate_doit (void *a)
619 struct relocate_args *args = (struct relocate_args *) a;
621 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
624 static void
625 map_doit (void *a)
627 struct map_args *args = (struct map_args *) a;
628 args->map = _dl_map_object (args->loader, args->str, lt_library, 0,
629 args->mode, LM_ID_BASE);
632 static void
633 dlmopen_doit (void *a)
635 struct dlmopen_args *args = (struct dlmopen_args *) a;
636 args->map = _dl_open (args->fname,
637 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
638 | __RTLD_SECURE),
639 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
640 __environ);
643 static void
644 lookup_doit (void *a)
646 struct lookup_args *args = (struct lookup_args *) a;
647 const ElfW(Sym) *ref = NULL;
648 args->result = NULL;
649 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
650 args->map->l_local_scope, NULL, 0,
651 DL_LOOKUP_RETURN_NEWEST, NULL);
652 if (ref != NULL)
653 args->result = DL_SYMBOL_ADDRESS (l, ref);
656 static void
657 version_check_doit (void *a)
659 struct version_check_args *args = (struct version_check_args *) a;
660 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
661 args->dotrace) && args->doexit)
662 /* We cannot start the application. Abort now. */
663 _exit (1);
667 static inline struct link_map *
668 find_needed (const char *name)
670 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
671 unsigned int n = scope->r_nlist;
673 while (n-- > 0)
674 if (_dl_name_match_p (name, scope->r_list[n]))
675 return scope->r_list[n];
677 /* Should never happen. */
678 return NULL;
681 static int
682 match_version (const char *string, struct link_map *map)
684 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
685 ElfW(Verdef) *def;
687 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
688 if (map->l_info[VERDEFTAG] == NULL)
689 /* The file has no symbol versioning. */
690 return 0;
692 def = (ElfW(Verdef) *) ((char *) map->l_addr
693 + map->l_info[VERDEFTAG]->d_un.d_ptr);
694 while (1)
696 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
698 /* Compare the version strings. */
699 if (strcmp (string, strtab + aux->vda_name) == 0)
700 /* Bingo! */
701 return 1;
703 /* If no more definitions we failed to find what we want. */
704 if (def->vd_next == 0)
705 break;
707 /* Next definition. */
708 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
711 return 0;
714 static bool tls_init_tp_called;
716 static void *
717 init_tls (void)
719 /* Number of elements in the static TLS block. */
720 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
722 /* Do not do this twice. The audit interface might have required
723 the DTV interfaces to be set up early. */
724 if (GL(dl_initial_dtv) != NULL)
725 return NULL;
727 /* Allocate the array which contains the information about the
728 dtv slots. We allocate a few entries more than needed to
729 avoid the need for reallocation. */
730 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
732 /* Allocate. */
733 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
734 calloc (sizeof (struct dtv_slotinfo_list)
735 + nelem * sizeof (struct dtv_slotinfo), 1);
736 /* No need to check the return value. If memory allocation failed
737 the program would have been terminated. */
739 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
740 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
741 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
743 /* Fill in the information from the loaded modules. No namespace
744 but the base one can be filled at this time. */
745 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
746 int i = 0;
747 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
748 l = l->l_next)
749 if (l->l_tls_blocksize != 0)
751 /* This is a module with TLS data. Store the map reference.
752 The generation counter is zero. */
753 slotinfo[i].map = l;
754 /* slotinfo[i].gen = 0; */
755 ++i;
757 assert (i == GL(dl_tls_max_dtv_idx));
759 /* Compute the TLS offsets for the various blocks. */
760 _dl_determine_tlsoffset ();
762 /* Construct the static TLS block and the dtv for the initial
763 thread. For some platforms this will include allocating memory
764 for the thread descriptor. The memory for the TLS block will
765 never be freed. It should be allocated accordingly. The dtv
766 array can be changed if dynamic loading requires it. */
767 void *tcbp = _dl_allocate_tls_storage ();
768 if (tcbp == NULL)
769 _dl_fatal_printf ("\
770 cannot allocate TLS data structures for initial thread");
772 /* Store for detection of the special case by __tls_get_addr
773 so it knows not to pass this dtv to the normal realloc. */
774 GL(dl_initial_dtv) = GET_DTV (tcbp);
776 /* And finally install it for the main thread. If ld.so itself uses
777 TLS we know the thread pointer was initialized earlier. */
778 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
779 if (__builtin_expect (lossage != NULL, 0))
780 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
781 tls_init_tp_called = true;
783 return tcbp;
786 #ifdef _LIBC_REENTRANT
787 /* _dl_error_catch_tsd points to this for the single-threaded case.
788 It's reset by the thread library for multithreaded programs. */
789 void ** __attribute__ ((const))
790 _dl_initial_error_catch_tsd (void)
792 static void *data;
793 return &data;
795 #endif
798 static unsigned int
799 do_preload (char *fname, struct link_map *main_map, const char *where)
801 const char *objname;
802 const char *err_str = NULL;
803 struct map_args args;
804 bool malloced;
806 args.str = fname;
807 args.loader = main_map;
808 args.mode = __RTLD_SECURE;
810 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
812 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
813 if (__builtin_expect (err_str != NULL, 0))
815 _dl_error_printf ("\
816 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
817 fname, where);
818 /* No need to call free, this is still before
819 the libc's malloc is used. */
821 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
822 /* It is no duplicate. */
823 return 1;
825 /* Nothing loaded. */
826 return 0;
829 #if defined SHARED && defined _LIBC_REENTRANT \
830 && defined __rtld_lock_default_lock_recursive
831 static void
832 rtld_lock_default_lock_recursive (void *lock)
834 __rtld_lock_default_lock_recursive (lock);
837 static void
838 rtld_lock_default_unlock_recursive (void *lock)
840 __rtld_lock_default_unlock_recursive (lock);
842 #endif
845 static void
846 security_init (void)
848 /* Set up the stack checker's canary. */
849 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
850 #ifdef THREAD_SET_STACK_GUARD
851 THREAD_SET_STACK_GUARD (stack_chk_guard);
852 #else
853 __stack_chk_guard = stack_chk_guard;
854 #endif
856 /* Set up the pointer guard as well, if necessary. */
857 if (GLRO(dl_pointer_guard))
859 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
860 stack_chk_guard);
861 #ifdef THREAD_SET_POINTER_GUARD
862 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
863 #endif
864 __pointer_chk_guard_local = pointer_chk_guard;
867 /* We do not need the _dl_random value anymore. The less
868 information we leave behind, the better, so clear the
869 variable. */
870 _dl_random = NULL;
874 /* The library search path. */
875 static const char *library_path attribute_relro;
876 /* The list preloaded objects. */
877 static const char *preloadlist attribute_relro;
878 /* Nonzero if information about versions has to be printed. */
879 static int version_info attribute_relro;
881 static void
882 dl_main (const ElfW(Phdr) *phdr,
883 ElfW(Word) phnum,
884 ElfW(Addr) *user_entry)
886 const ElfW(Phdr) *ph;
887 enum mode mode;
888 struct link_map *main_map;
889 size_t file_size;
890 char *file;
891 bool has_interp = false;
892 unsigned int i;
893 bool prelinked = false;
894 bool rtld_is_main = false;
895 #ifndef HP_TIMING_NONAVAIL
896 hp_timing_t start;
897 hp_timing_t stop;
898 hp_timing_t diff;
899 #endif
900 void *tcbp = NULL;
902 #ifdef _LIBC_REENTRANT
903 /* Explicit initialization since the reloc would just be more work. */
904 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
905 #endif
907 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
909 #if defined SHARED && defined _LIBC_REENTRANT \
910 && defined __rtld_lock_default_lock_recursive
911 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
912 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
913 #endif
915 /* The explicit initialization here is cheaper than processing the reloc
916 in the _rtld_local definition's initializer. */
917 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
919 /* Process the environment variable which control the behaviour. */
920 process_envvars (&mode);
922 #ifndef HAVE_INLINED_SYSCALLS
923 /* Set up a flag which tells we are just starting. */
924 INTUSE(_dl_starting_up) = 1;
925 #endif
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 else
1086 /* Create a link_map for the executable itself.
1087 This will be what dlopen on "" returns. */
1088 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1089 __RTLD_OPENEXEC, LM_ID_BASE);
1090 assert (main_map != NULL);
1091 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1092 main_map->l_phdr = phdr;
1093 main_map->l_phnum = phnum;
1094 main_map->l_entry = *user_entry;
1096 /* At this point we are in a bit of trouble. We would have to
1097 fill in the values for l_dev and l_ino. But in general we
1098 do not know where the file is. We also do not handle AT_EXECFD
1099 even if it would be passed up.
1101 We leave the values here defined to 0. This is normally no
1102 problem as the program code itself is normally no shared
1103 object and therefore cannot be loaded dynamically. Nothing
1104 prevent the use of dynamic binaries and in these situations
1105 we might get problems. We might not be able to find out
1106 whether the object is already loaded. But since there is no
1107 easy way out and because the dynamic binary must also not
1108 have an SONAME we ignore this program for now. If it becomes
1109 a problem we can force people using SONAMEs. */
1111 /* We delay initializing the path structure until we got the dynamic
1112 information for the program. */
1115 main_map->l_map_end = 0;
1116 main_map->l_text_end = 0;
1117 /* Perhaps the executable has no PT_LOAD header entries at all. */
1118 main_map->l_map_start = ~0;
1119 /* And it was opened directly. */
1120 ++main_map->l_direct_opencount;
1122 /* Scan the program header table for the dynamic section. */
1123 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1124 switch (ph->p_type)
1126 case PT_PHDR:
1127 /* Find out the load address. */
1128 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1129 break;
1130 case PT_DYNAMIC:
1131 /* This tells us where to find the dynamic section,
1132 which tells us everything we need to do. */
1133 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1134 break;
1135 case PT_INTERP:
1136 /* This "interpreter segment" was used by the program loader to
1137 find the program interpreter, which is this program itself, the
1138 dynamic linker. We note what name finds us, so that a future
1139 dlopen call or DT_NEEDED entry, for something that wants to link
1140 against the dynamic linker as a shared library, will know that
1141 the shared object is already loaded. */
1142 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1143 + ph->p_vaddr);
1144 /* _dl_rtld_libname.next = NULL; Already zero. */
1145 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1147 /* Ordinarilly, we would get additional names for the loader from
1148 our DT_SONAME. This can't happen if we were actually linked as
1149 a static executable (detect this case when we have no DYNAMIC).
1150 If so, assume the filename component of the interpreter path to
1151 be our SONAME, and add it to our name list. */
1152 if (GL(dl_rtld_map).l_ld == NULL)
1154 const char *p = NULL;
1155 const char *cp = _dl_rtld_libname.name;
1157 /* Find the filename part of the path. */
1158 while (*cp != '\0')
1159 if (*cp++ == '/')
1160 p = cp;
1162 if (p != NULL)
1164 _dl_rtld_libname2.name = p;
1165 /* _dl_rtld_libname2.next = NULL; Already zero. */
1166 _dl_rtld_libname.next = &_dl_rtld_libname2;
1170 has_interp = true;
1171 break;
1172 case PT_LOAD:
1174 ElfW(Addr) mapstart;
1175 ElfW(Addr) allocend;
1177 /* Remember where the main program starts in memory. */
1178 mapstart = (main_map->l_addr
1179 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1180 if (main_map->l_map_start > mapstart)
1181 main_map->l_map_start = mapstart;
1183 /* Also where it ends. */
1184 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1185 if (main_map->l_map_end < allocend)
1186 main_map->l_map_end = allocend;
1187 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1188 main_map->l_text_end = allocend;
1190 break;
1192 case PT_TLS:
1193 if (ph->p_memsz > 0)
1195 /* Note that in the case the dynamic linker we duplicate work
1196 here since we read the PT_TLS entry already in
1197 _dl_start_final. But the result is repeatable so do not
1198 check for this special but unimportant case. */
1199 main_map->l_tls_blocksize = ph->p_memsz;
1200 main_map->l_tls_align = ph->p_align;
1201 if (ph->p_align == 0)
1202 main_map->l_tls_firstbyte_offset = 0;
1203 else
1204 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1205 & (ph->p_align - 1));
1206 main_map->l_tls_initimage_size = ph->p_filesz;
1207 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1209 /* This image gets the ID one. */
1210 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1212 break;
1214 case PT_GNU_STACK:
1215 GL(dl_stack_flags) = ph->p_flags;
1216 break;
1218 case PT_GNU_RELRO:
1219 main_map->l_relro_addr = ph->p_vaddr;
1220 main_map->l_relro_size = ph->p_memsz;
1221 break;
1224 /* Adjust the address of the TLS initialization image in case
1225 the executable is actually an ET_DYN object. */
1226 if (main_map->l_tls_initimage != NULL)
1227 main_map->l_tls_initimage
1228 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1229 if (! main_map->l_map_end)
1230 main_map->l_map_end = ~0;
1231 if (! main_map->l_text_end)
1232 main_map->l_text_end = ~0;
1233 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1235 /* We were invoked directly, so the program might not have a
1236 PT_INTERP. */
1237 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1238 /* _dl_rtld_libname.next = NULL; Already zero. */
1239 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1241 else
1242 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1244 /* If the current libname is different from the SONAME, add the
1245 latter as well. */
1246 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1247 && strcmp (GL(dl_rtld_map).l_libname->name,
1248 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1249 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1251 static struct libname_list newname;
1252 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1253 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1254 newname.next = NULL;
1255 newname.dont_free = 1;
1257 assert (GL(dl_rtld_map).l_libname->next == NULL);
1258 GL(dl_rtld_map).l_libname->next = &newname;
1260 /* The ld.so must be relocated since otherwise loading audit modules
1261 will fail since they reuse the very same ld.so. */
1262 assert (GL(dl_rtld_map).l_relocated);
1264 if (! rtld_is_main)
1266 /* Extract the contents of the dynamic section for easy access. */
1267 elf_get_dynamic_info (main_map, NULL);
1268 /* Set up our cache of pointers into the hash table. */
1269 _dl_setup_hash (main_map);
1272 if (__builtin_expect (mode, normal) == verify)
1274 /* We were called just to verify that this is a dynamic
1275 executable using us as the program interpreter. Exit with an
1276 error if we were not able to load the binary or no interpreter
1277 is specified (i.e., this is no dynamically linked binary. */
1278 if (main_map->l_ld == NULL)
1279 _exit (1);
1281 /* We allow here some platform specific code. */
1282 #ifdef DISTINGUISH_LIB_VERSIONS
1283 DISTINGUISH_LIB_VERSIONS;
1284 #endif
1285 _exit (has_interp ? 0 : 2);
1288 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1289 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1290 /* Set up the data structures for the system-supplied DSO early,
1291 so they can influence _dl_init_paths. */
1292 if (GLRO(dl_sysinfo_dso) != NULL)
1294 /* Do an abridged version of the work _dl_map_object_from_fd would do
1295 to map in the object. It's already mapped and prelinked (and
1296 better be, since it's read-only and so we couldn't relocate it).
1297 We just want our data structures to describe it as if we had just
1298 mapped and relocated it normally. */
1299 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1300 0, LM_ID_BASE);
1301 if (__builtin_expect (l != NULL, 1))
1303 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1305 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1306 + GLRO(dl_sysinfo_dso)->e_phoff);
1307 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1308 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1310 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1311 if (ph->p_type == PT_DYNAMIC)
1313 l->l_ld = (void *) ph->p_vaddr;
1314 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1316 else if (ph->p_type == PT_LOAD)
1318 if (! l->l_addr)
1319 l->l_addr = ph->p_vaddr;
1320 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1321 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1322 if ((ph->p_flags & PF_X)
1323 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1324 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1326 else
1327 /* There must be no TLS segment. */
1328 assert (ph->p_type != PT_TLS);
1330 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1331 l->l_addr = l->l_map_start - l->l_addr;
1332 l->l_map_end += l->l_addr;
1333 l->l_text_end += l->l_addr;
1334 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1335 elf_get_dynamic_info (l, dyn_temp);
1336 _dl_setup_hash (l);
1337 l->l_relocated = 1;
1339 /* Initialize l_local_scope to contain just this map. This allows
1340 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1341 So we create a single entry list pointing to l_real as its only
1342 element */
1343 l->l_local_scope[0]->r_nlist = 1;
1344 l->l_local_scope[0]->r_list = &l->l_real;
1346 /* Now that we have the info handy, use the DSO image's soname
1347 so this object can be looked up by name. Note that we do not
1348 set l_name here. That field gives the file name of the DSO,
1349 and this DSO is not associated with any file. */
1350 if (l->l_info[DT_SONAME] != NULL)
1352 /* Work around a kernel problem. The kernel cannot handle
1353 addresses in the vsyscall DSO pages in writev() calls. */
1354 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1355 + l->l_info[DT_SONAME]->d_un.d_val);
1356 size_t len = strlen (dsoname);
1357 char *copy = malloc (len);
1358 if (copy == NULL)
1359 _dl_fatal_printf ("out of memory\n");
1360 l->l_libname->name = memcpy (copy, dsoname, len);
1363 /* Rearrange the list so this DSO appears after rtld_map. */
1364 assert (l->l_next == NULL);
1365 assert (l->l_prev == main_map);
1366 GL(dl_rtld_map).l_next = l;
1367 l->l_prev = &GL(dl_rtld_map);
1368 first_preload = &l->l_next;
1370 /* We have a prelinked DSO preloaded by the system. */
1371 GLRO(dl_sysinfo_map) = l;
1372 # ifdef NEED_DL_SYSINFO
1373 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1374 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1375 # endif
1378 #endif
1380 #ifdef DL_SYSDEP_OSCHECK
1381 DL_SYSDEP_OSCHECK (dl_fatal);
1382 #endif
1384 /* Initialize the data structures for the search paths for shared
1385 objects. */
1386 _dl_init_paths (library_path);
1388 /* Initialize _r_debug. */
1389 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1390 LM_ID_BASE);
1391 r->r_state = RT_CONSISTENT;
1393 /* Put the link_map for ourselves on the chain so it can be found by
1394 name. Note that at this point the global chain of link maps contains
1395 exactly one element, which is pointed to by dl_loaded. */
1396 if (! GL(dl_rtld_map).l_name)
1397 /* If not invoked directly, the dynamic linker shared object file was
1398 found by the PT_INTERP name. */
1399 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1400 GL(dl_rtld_map).l_type = lt_library;
1401 main_map->l_next = &GL(dl_rtld_map);
1402 GL(dl_rtld_map).l_prev = main_map;
1403 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1404 ++GL(dl_load_adds);
1406 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1407 to not using bias for non-prelinked PIEs and libraries
1408 and using it for executables or prelinked PIEs or libraries. */
1409 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1410 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1412 /* Set up the program header information for the dynamic linker
1413 itself. It is needed in the dl_iterate_phdr() callbacks. */
1414 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1415 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1416 + rtld_ehdr->e_phoff);
1417 GL(dl_rtld_map).l_phdr = rtld_phdr;
1418 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1421 /* PT_GNU_RELRO is usually the last phdr. */
1422 size_t cnt = rtld_ehdr->e_phnum;
1423 while (cnt-- > 0)
1424 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1426 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1427 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1428 break;
1431 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1432 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1433 /* Assign a module ID. Do this before loading any audit modules. */
1434 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1436 /* If we have auditing DSOs to load, do it now. */
1437 if (__builtin_expect (audit_list != NULL, 0))
1439 /* Iterate over all entries in the list. The order is important. */
1440 struct audit_ifaces *last_audit = NULL;
1441 struct audit_list *al = audit_list->next;
1443 /* Since we start using the auditing DSOs right away we need to
1444 initialize the data structures now. */
1445 tcbp = init_tls ();
1447 /* Initialize security features. We need to do it this early
1448 since otherwise the constructors of the audit libraries will
1449 use different values (especially the pointer guard) and will
1450 fail later on. */
1451 security_init ();
1455 int tls_idx = GL(dl_tls_max_dtv_idx);
1457 /* Now it is time to determine the layout of the static TLS
1458 block and allocate it for the initial thread. Note that we
1459 always allocate the static block, we never defer it even if
1460 no DF_STATIC_TLS bit is set. The reason is that we know
1461 glibc will use the static model. */
1462 struct dlmopen_args dlmargs;
1463 dlmargs.fname = al->name;
1464 dlmargs.map = NULL;
1466 const char *objname;
1467 const char *err_str = NULL;
1468 bool malloced;
1469 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1470 &dlmargs);
1471 if (__builtin_expect (err_str != NULL, 0))
1473 not_loaded:
1474 _dl_error_printf ("\
1475 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1476 al->name, err_str);
1477 if (malloced)
1478 free ((char *) err_str);
1480 else
1482 struct lookup_args largs;
1483 largs.name = "la_version";
1484 largs.map = dlmargs.map;
1486 /* Check whether the interface version matches. */
1487 (void) _dl_catch_error (&objname, &err_str, &malloced,
1488 lookup_doit, &largs);
1490 unsigned int (*laversion) (unsigned int);
1491 unsigned int lav;
1492 if (err_str == NULL
1493 && (laversion = largs.result) != NULL
1494 && (lav = laversion (LAV_CURRENT)) > 0
1495 && lav <= LAV_CURRENT)
1497 /* Allocate structure for the callback function pointers.
1498 This call can never fail. */
1499 union
1501 struct audit_ifaces ifaces;
1502 #define naudit_ifaces 8
1503 void (*fptr[naudit_ifaces]) (void);
1504 } *newp = malloc (sizeof (*newp));
1506 /* Names of the auditing interfaces. All in one
1507 long string. */
1508 static const char audit_iface_names[] =
1509 "la_activity\0"
1510 "la_objsearch\0"
1511 "la_objopen\0"
1512 "la_preinit\0"
1513 #if __ELF_NATIVE_CLASS == 32
1514 "la_symbind32\0"
1515 #elif __ELF_NATIVE_CLASS == 64
1516 "la_symbind64\0"
1517 #else
1518 # error "__ELF_NATIVE_CLASS must be defined"
1519 #endif
1520 #define STRING(s) __STRING (s)
1521 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1522 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1523 "la_objclose\0";
1524 unsigned int cnt = 0;
1525 const char *cp = audit_iface_names;
1528 largs.name = cp;
1529 (void) _dl_catch_error (&objname, &err_str, &malloced,
1530 lookup_doit, &largs);
1532 /* Store the pointer. */
1533 if (err_str == NULL && largs.result != NULL)
1535 newp->fptr[cnt] = largs.result;
1537 /* The dynamic linker link map is statically
1538 allocated, initialize the data now. */
1539 GL(dl_rtld_map).l_audit[cnt].cookie
1540 = (intptr_t) &GL(dl_rtld_map);
1542 else
1543 newp->fptr[cnt] = NULL;
1544 ++cnt;
1546 cp = (char *) rawmemchr (cp, '\0') + 1;
1548 while (*cp != '\0');
1549 assert (cnt == naudit_ifaces);
1551 /* Now append the new auditing interface to the list. */
1552 newp->ifaces.next = NULL;
1553 if (last_audit == NULL)
1554 last_audit = GLRO(dl_audit) = &newp->ifaces;
1555 else
1556 last_audit = last_audit->next = &newp->ifaces;
1557 ++GLRO(dl_naudit);
1559 /* Mark the DSO as being used for auditing. */
1560 dlmargs.map->l_auditing = 1;
1562 else
1564 /* We cannot use the DSO, it does not have the
1565 appropriate interfaces or it expects something
1566 more recent. */
1567 #ifndef NDEBUG
1568 Lmid_t ns = dlmargs.map->l_ns;
1569 #endif
1570 _dl_close (dlmargs.map);
1572 /* Make sure the namespace has been cleared entirely. */
1573 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1574 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1576 GL(dl_tls_max_dtv_idx) = tls_idx;
1577 goto not_loaded;
1581 al = al->next;
1583 while (al != audit_list->next);
1585 /* If we have any auditing modules, announce that we already
1586 have two objects loaded. */
1587 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1589 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1591 for (unsigned int outer = 0; outer < 2; ++outer)
1593 struct audit_ifaces *afct = GLRO(dl_audit);
1594 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1596 if (afct->objopen != NULL)
1598 ls[outer]->l_audit[cnt].bindflags
1599 = afct->objopen (ls[outer], LM_ID_BASE,
1600 &ls[outer]->l_audit[cnt].cookie);
1602 ls[outer]->l_audit_any_plt
1603 |= ls[outer]->l_audit[cnt].bindflags != 0;
1606 afct = afct->next;
1612 /* Set up debugging before the debugger is notified for the first time. */
1613 #ifdef ELF_MACHINE_DEBUG_SETUP
1614 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1615 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1616 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1617 #else
1618 if (main_map->l_info[DT_DEBUG] != NULL)
1619 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1620 with the run-time address of the r_debug structure */
1621 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1623 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1624 case you run gdb on the dynamic linker directly. */
1625 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1626 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1627 #endif
1629 /* We start adding objects. */
1630 r->r_state = RT_ADD;
1631 _dl_debug_state ();
1633 /* Auditing checkpoint: we are ready to signal that the initial map
1634 is being constructed. */
1635 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1637 struct audit_ifaces *afct = GLRO(dl_audit);
1638 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1640 if (afct->activity != NULL)
1641 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1643 afct = afct->next;
1647 /* We have two ways to specify objects to preload: via environment
1648 variable and via the file /etc/ld.so.preload. The latter can also
1649 be used when security is enabled. */
1650 assert (*first_preload == NULL);
1651 struct link_map **preloads = NULL;
1652 unsigned int npreloads = 0;
1654 if (__builtin_expect (preloadlist != NULL, 0))
1656 /* The LD_PRELOAD environment variable gives list of libraries
1657 separated by white space or colons that are loaded before the
1658 executable's dependencies and prepended to the global scope
1659 list. If the binary is running setuid all elements
1660 containing a '/' are ignored since it is insecure. */
1661 char *list = strdupa (preloadlist);
1662 char *p;
1664 HP_TIMING_NOW (start);
1666 /* Prevent optimizing strsep. Speed is not important here. */
1667 while ((p = (strsep) (&list, " :")) != NULL)
1668 if (p[0] != '\0'
1669 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1670 || strchr (p, '/') == NULL))
1671 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1673 HP_TIMING_NOW (stop);
1674 HP_TIMING_DIFF (diff, start, stop);
1675 HP_TIMING_ACCUM_NT (load_time, diff);
1678 /* There usually is no ld.so.preload file, it should only be used
1679 for emergencies and testing. So the open call etc should usually
1680 fail. Using access() on a non-existing file is faster than using
1681 open(). So we do this first. If it succeeds we do almost twice
1682 the work but this does not matter, since it is not for production
1683 use. */
1684 static const char preload_file[] = "/etc/ld.so.preload";
1685 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1687 /* Read the contents of the file. */
1688 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1689 PROT_READ | PROT_WRITE);
1690 if (__builtin_expect (file != MAP_FAILED, 0))
1692 /* Parse the file. It contains names of libraries to be loaded,
1693 separated by white spaces or `:'. It may also contain
1694 comments introduced by `#'. */
1695 char *problem;
1696 char *runp;
1697 size_t rest;
1699 /* Eliminate comments. */
1700 runp = file;
1701 rest = file_size;
1702 while (rest > 0)
1704 char *comment = memchr (runp, '#', rest);
1705 if (comment == NULL)
1706 break;
1708 rest -= comment - runp;
1710 *comment = ' ';
1711 while (--rest > 0 && *++comment != '\n');
1714 /* We have one problematic case: if we have a name at the end of
1715 the file without a trailing terminating characters, we cannot
1716 place the \0. Handle the case separately. */
1717 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1718 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1720 problem = &file[file_size];
1721 while (problem > file && problem[-1] != ' '
1722 && problem[-1] != '\t'
1723 && problem[-1] != '\n' && problem[-1] != ':')
1724 --problem;
1726 if (problem > file)
1727 problem[-1] = '\0';
1729 else
1731 problem = NULL;
1732 file[file_size - 1] = '\0';
1735 HP_TIMING_NOW (start);
1737 if (file != problem)
1739 char *p;
1740 runp = file;
1741 while ((p = strsep (&runp, ": \t\n")) != NULL)
1742 if (p[0] != '\0')
1743 npreloads += do_preload (p, main_map, preload_file);
1746 if (problem != NULL)
1748 char *p = strndupa (problem, file_size - (problem - file));
1750 npreloads += do_preload (p, main_map, preload_file);
1753 HP_TIMING_NOW (stop);
1754 HP_TIMING_DIFF (diff, start, stop);
1755 HP_TIMING_ACCUM_NT (load_time, diff);
1757 /* We don't need the file anymore. */
1758 __munmap (file, file_size);
1762 if (__builtin_expect (*first_preload != NULL, 0))
1764 /* Set up PRELOADS with a vector of the preloaded libraries. */
1765 struct link_map *l = *first_preload;
1766 preloads = __alloca (npreloads * sizeof preloads[0]);
1767 i = 0;
1770 preloads[i++] = l;
1771 l = l->l_next;
1772 } while (l);
1773 assert (i == npreloads);
1776 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1777 specified some libraries to load, these are inserted before the actual
1778 dependencies in the executable's searchlist for symbol resolution. */
1779 HP_TIMING_NOW (start);
1780 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1781 HP_TIMING_NOW (stop);
1782 HP_TIMING_DIFF (diff, start, stop);
1783 HP_TIMING_ACCUM_NT (load_time, diff);
1785 /* Mark all objects as being in the global scope. */
1786 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1787 main_map->l_searchlist.r_list[--i]->l_global = 1;
1789 /* Remove _dl_rtld_map from the chain. */
1790 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1791 if (GL(dl_rtld_map).l_next != NULL)
1792 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1794 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1795 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1796 break;
1798 bool rtld_multiple_ref = false;
1799 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1801 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1802 put it back in the list of visible objects. We insert it into the
1803 chain in symbol search order because gdb uses the chain's order as
1804 its symbol search order. */
1805 rtld_multiple_ref = true;
1807 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1808 if (__builtin_expect (mode, normal) == normal)
1810 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1811 ? main_map->l_searchlist.r_list[i + 1]
1812 : NULL);
1813 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1814 if (GLRO(dl_sysinfo_map) != NULL
1815 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1816 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1817 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1818 #endif
1820 else
1821 /* In trace mode there might be an invisible object (which we
1822 could not find) after the previous one in the search list.
1823 In this case it doesn't matter much where we put the
1824 interpreter object, so we just initialize the list pointer so
1825 that the assertion below holds. */
1826 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1828 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1829 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1830 if (GL(dl_rtld_map).l_next != NULL)
1832 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1833 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1837 /* Now let us see whether all libraries are available in the
1838 versions we need. */
1840 struct version_check_args args;
1841 args.doexit = mode == normal;
1842 args.dotrace = mode == trace;
1843 _dl_receive_error (print_missing_version, version_check_doit, &args);
1846 /* We do not initialize any of the TLS functionality unless any of the
1847 initial modules uses TLS. This makes dynamic loading of modules with
1848 TLS impossible, but to support it requires either eagerly doing setup
1849 now or lazily doing it later. Doing it now makes us incompatible with
1850 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1851 used. Trying to do it lazily is too hairy to try when there could be
1852 multiple threads (from a non-TLS-using libpthread). */
1853 bool was_tls_init_tp_called = tls_init_tp_called;
1854 if (tcbp == NULL)
1855 tcbp = init_tls ();
1857 if (__builtin_expect (audit_list == NULL, 1))
1858 /* Initialize security features. But only if we have not done it
1859 earlier. */
1860 security_init ();
1862 if (__builtin_expect (mode, normal) != normal)
1864 /* We were run just to list the shared libraries. It is
1865 important that we do this before real relocation, because the
1866 functions we call below for output may no longer work properly
1867 after relocation. */
1868 struct link_map *l;
1870 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1872 struct r_scope_elem *scope = &main_map->l_searchlist;
1874 for (i = 0; i < scope->r_nlist; i++)
1876 l = scope->r_list [i];
1877 if (l->l_faked)
1879 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1880 continue;
1882 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1883 GLRO(dl_trace_prelink_map) = l;
1884 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1885 l->l_libname->name[0] ? l->l_libname->name
1886 : rtld_progname ?: "<main program>",
1887 l->l_name[0] ? l->l_name
1888 : rtld_progname ?: "<main program>",
1889 (int) sizeof l->l_map_start * 2,
1890 (size_t) l->l_map_start,
1891 (int) sizeof l->l_addr * 2,
1892 (size_t) l->l_addr);
1894 if (l->l_tls_modid)
1895 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1896 (int) sizeof l->l_tls_offset * 2,
1897 (size_t) l->l_tls_offset);
1898 else
1899 _dl_printf ("\n");
1902 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1904 /* Look through the dependencies of the main executable
1905 and determine which of them is not actually
1906 required. */
1907 struct link_map *l = main_map;
1909 /* Relocate the main executable. */
1910 struct relocate_args args = { .l = l,
1911 .reloc_mode = (GLRO(dl_lazy)
1912 ? RTLD_LAZY : 0) };
1913 _dl_receive_error (print_unresolved, relocate_doit, &args);
1915 /* This loop depends on the dependencies of the executable to
1916 correspond in number and order to the DT_NEEDED entries. */
1917 ElfW(Dyn) *dyn = main_map->l_ld;
1918 bool first = true;
1919 while (dyn->d_tag != DT_NULL)
1921 if (dyn->d_tag == DT_NEEDED)
1923 l = l->l_next;
1925 if (!l->l_used)
1927 if (first)
1929 _dl_printf ("Unused direct dependencies:\n");
1930 first = false;
1933 _dl_printf ("\t%s\n", l->l_name);
1937 ++dyn;
1940 _exit (first != true);
1942 else if (! main_map->l_info[DT_NEEDED])
1943 _dl_printf ("\tstatically linked\n");
1944 else
1946 for (l = main_map->l_next; l; l = l->l_next)
1947 if (l->l_faked)
1948 /* The library was not found. */
1949 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1950 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1951 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1952 (int) sizeof l->l_map_start * 2,
1953 (size_t) l->l_map_start);
1954 else
1955 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1956 l->l_name, (int) sizeof l->l_map_start * 2,
1957 (size_t) l->l_map_start);
1960 if (__builtin_expect (mode, trace) != trace)
1961 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1963 const ElfW(Sym) *ref = NULL;
1964 ElfW(Addr) loadbase;
1965 lookup_t result;
1967 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1968 &ref, main_map->l_scope,
1969 NULL, ELF_RTYPE_CLASS_PLT,
1970 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1972 loadbase = LOOKUP_VALUE_ADDRESS (result);
1974 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1975 INTUSE(_dl_argv)[i],
1976 (int) sizeof ref->st_value * 2,
1977 (size_t) ref->st_value,
1978 (int) sizeof loadbase * 2, (size_t) loadbase);
1980 else
1982 /* If LD_WARN is set, warn about undefined symbols. */
1983 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1985 /* We have to do symbol dependency testing. */
1986 struct relocate_args args;
1987 struct link_map *l;
1989 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
1991 l = main_map;
1992 while (l->l_next != NULL)
1993 l = l->l_next;
1996 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1998 args.l = l;
1999 _dl_receive_error (print_unresolved, relocate_doit,
2000 &args);
2002 l = l->l_prev;
2004 while (l != NULL);
2006 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2007 && rtld_multiple_ref)
2009 /* Mark the link map as not yet relocated again. */
2010 GL(dl_rtld_map).l_relocated = 0;
2011 _dl_relocate_object (&GL(dl_rtld_map),
2012 main_map->l_scope, 0, 0);
2015 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2016 if (version_info)
2018 /* Print more information. This means here, print information
2019 about the versions needed. */
2020 int first = 1;
2021 struct link_map *map;
2023 for (map = main_map; map != NULL; map = map->l_next)
2025 const char *strtab;
2026 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2027 ElfW(Verneed) *ent;
2029 if (dyn == NULL)
2030 continue;
2032 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2033 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2035 if (first)
2037 _dl_printf ("\n\tVersion information:\n");
2038 first = 0;
2041 _dl_printf ("\t%s:\n",
2042 map->l_name[0] ? map->l_name : rtld_progname);
2044 while (1)
2046 ElfW(Vernaux) *aux;
2047 struct link_map *needed;
2049 needed = find_needed (strtab + ent->vn_file);
2050 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2052 while (1)
2054 const char *fname = NULL;
2056 if (needed != NULL
2057 && match_version (strtab + aux->vna_name,
2058 needed))
2059 fname = needed->l_name;
2061 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2062 strtab + ent->vn_file,
2063 strtab + aux->vna_name,
2064 aux->vna_flags & VER_FLG_WEAK
2065 ? "[WEAK] " : "",
2066 fname ?: "not found");
2068 if (aux->vna_next == 0)
2069 /* No more symbols. */
2070 break;
2072 /* Next symbol. */
2073 aux = (ElfW(Vernaux) *) ((char *) aux
2074 + aux->vna_next);
2077 if (ent->vn_next == 0)
2078 /* No more dependencies. */
2079 break;
2081 /* Next dependency. */
2082 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2088 _exit (0);
2091 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2092 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2093 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2095 ElfW(Lib) *liblist, *liblistend;
2096 struct link_map **r_list, **r_listend, *l;
2097 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2099 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2100 liblist = (ElfW(Lib) *)
2101 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2102 liblistend = (ElfW(Lib) *)
2103 ((char *) liblist +
2104 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2105 r_list = main_map->l_searchlist.r_list;
2106 r_listend = r_list + main_map->l_searchlist.r_nlist;
2108 for (; r_list < r_listend && liblist < liblistend; r_list++)
2110 l = *r_list;
2112 if (l == main_map)
2113 continue;
2115 /* If the library is not mapped where it should, fail. */
2116 if (l->l_addr)
2117 break;
2119 /* Next, check if checksum matches. */
2120 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2121 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2122 != liblist->l_checksum)
2123 break;
2125 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2126 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2127 != liblist->l_time_stamp)
2128 break;
2130 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2131 break;
2133 ++liblist;
2137 if (r_list == r_listend && liblist == liblistend)
2138 prelinked = true;
2140 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2141 _dl_debug_printf ("\nprelink checking: %s\n",
2142 prelinked ? "ok" : "failed");
2146 /* Now set up the variable which helps the assembler startup code. */
2147 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2149 /* Save the information about the original global scope list since
2150 we need it in the memory handling later. */
2151 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2153 if (prelinked)
2155 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2157 ElfW(Rela) *conflict, *conflictend;
2158 #ifndef HP_TIMING_NONAVAIL
2159 hp_timing_t start;
2160 hp_timing_t stop;
2161 #endif
2163 HP_TIMING_NOW (start);
2164 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2165 conflict = (ElfW(Rela) *)
2166 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2167 conflictend = (ElfW(Rela) *)
2168 ((char *) conflict
2169 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2170 _dl_resolve_conflicts (main_map, conflict, conflictend);
2171 HP_TIMING_NOW (stop);
2172 HP_TIMING_DIFF (relocate_time, start, stop);
2176 /* Mark all the objects so we know they have been already relocated. */
2177 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2179 l->l_relocated = 1;
2180 if (l->l_relro_size)
2181 _dl_protect_relro (l);
2183 /* Add object to slot information data if necessasy. */
2184 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2185 _dl_add_to_slotinfo (l);
2188 else
2190 /* Now we have all the objects loaded. Relocate them all except for
2191 the dynamic linker itself. We do this in reverse order so that copy
2192 relocs of earlier objects overwrite the data written by later
2193 objects. We do not re-relocate the dynamic linker itself in this
2194 loop because that could result in the GOT entries for functions we
2195 call being changed, and that would break us. It is safe to relocate
2196 the dynamic linker out of order because it has no copy relocs (we
2197 know that because it is self-contained). */
2199 int consider_profiling = GLRO(dl_profile) != NULL;
2200 #ifndef HP_TIMING_NONAVAIL
2201 hp_timing_t start;
2202 hp_timing_t stop;
2203 #endif
2205 /* If we are profiling we also must do lazy reloaction. */
2206 GLRO(dl_lazy) |= consider_profiling;
2208 struct link_map *l = main_map;
2209 while (l->l_next)
2210 l = l->l_next;
2212 HP_TIMING_NOW (start);
2215 /* While we are at it, help the memory handling a bit. We have to
2216 mark some data structures as allocated with the fake malloc()
2217 implementation in ld.so. */
2218 struct libname_list *lnp = l->l_libname->next;
2220 while (__builtin_expect (lnp != NULL, 0))
2222 lnp->dont_free = 1;
2223 lnp = lnp->next;
2226 if (l != &GL(dl_rtld_map))
2227 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2228 consider_profiling);
2230 /* Add object to slot information data if necessasy. */
2231 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2232 _dl_add_to_slotinfo (l);
2234 l = l->l_prev;
2236 while (l);
2237 HP_TIMING_NOW (stop);
2239 HP_TIMING_DIFF (relocate_time, start, stop);
2241 /* Now enable profiling if needed. Like the previous call,
2242 this has to go here because the calls it makes should use the
2243 rtld versions of the functions (particularly calloc()), but it
2244 needs to have _dl_profile_map set up by the relocator. */
2245 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2246 /* We must prepare the profiling. */
2247 _dl_start_profile ();
2250 #ifndef NONTLS_INIT_TP
2251 # define NONTLS_INIT_TP do { } while (0)
2252 #endif
2254 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2255 ++GL(dl_tls_generation);
2257 /* Now that we have completed relocation, the initializer data
2258 for the TLS blocks has its final values and we can copy them
2259 into the main thread's TLS area, which we allocated above. */
2260 _dl_allocate_tls_init (tcbp);
2262 /* And finally install it for the main thread. If ld.so itself uses
2263 TLS we know the thread pointer was initialized earlier. */
2264 if (! tls_init_tp_called)
2266 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2267 if (__builtin_expect (lossage != NULL, 0))
2268 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2269 lossage);
2272 if (! prelinked && rtld_multiple_ref)
2274 /* There was an explicit ref to the dynamic linker as a shared lib.
2275 Re-relocate ourselves with user-controlled symbol definitions.
2277 We must do this after TLS initialization in case after this
2278 re-relocation, we might call a user-supplied function
2279 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2281 #ifndef HP_TIMING_NONAVAIL
2282 hp_timing_t start;
2283 hp_timing_t stop;
2284 hp_timing_t add;
2285 #endif
2287 HP_TIMING_NOW (start);
2288 /* Mark the link map as not yet relocated again. */
2289 GL(dl_rtld_map).l_relocated = 0;
2290 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2291 HP_TIMING_NOW (stop);
2292 HP_TIMING_DIFF (add, start, stop);
2293 HP_TIMING_ACCUM_NT (relocate_time, add);
2296 /* Do any necessary cleanups for the startup OS interface code.
2297 We do these now so that no calls are made after rtld re-relocation
2298 which might be resolved to different functions than we expect.
2299 We cannot do this before relocating the other objects because
2300 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2301 _dl_sysdep_start_cleanup ();
2303 #ifdef SHARED
2304 /* Auditing checkpoint: we have added all objects. */
2305 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2307 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2308 /* Do not call the functions for any auditing object. */
2309 if (head->l_auditing == 0)
2311 struct audit_ifaces *afct = GLRO(dl_audit);
2312 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2314 if (afct->activity != NULL)
2315 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2317 afct = afct->next;
2321 #endif
2323 /* Notify the debugger all new objects are now ready to go. We must re-get
2324 the address since by now the variable might be in another object. */
2325 r = _dl_debug_initialize (0, LM_ID_BASE);
2326 r->r_state = RT_CONSISTENT;
2327 _dl_debug_state ();
2329 #ifndef MAP_COPY
2330 /* We must munmap() the cache file. */
2331 _dl_unload_cache ();
2332 #endif
2334 /* Once we return, _dl_sysdep_start will invoke
2335 the DT_INIT functions and then *USER_ENTRY. */
2338 /* This is a little helper function for resolving symbols while
2339 tracing the binary. */
2340 static void
2341 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2342 const char *errstring)
2344 if (objname[0] == '\0')
2345 objname = rtld_progname ?: "<main program>";
2346 _dl_error_printf ("%s (%s)\n", errstring, objname);
2349 /* This is a little helper function for resolving symbols while
2350 tracing the binary. */
2351 static void
2352 print_missing_version (int errcode __attribute__ ((unused)),
2353 const char *objname, const char *errstring)
2355 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2356 objname, errstring);
2359 /* Nonzero if any of the debugging options is enabled. */
2360 static int any_debug attribute_relro;
2362 /* Process the string given as the parameter which explains which debugging
2363 options are enabled. */
2364 static void
2365 process_dl_debug (const char *dl_debug)
2367 /* When adding new entries make sure that the maximal length of a name
2368 is correctly handled in the LD_DEBUG_HELP code below. */
2369 static const struct
2371 unsigned char len;
2372 const char name[10];
2373 const char helptext[41];
2374 unsigned short int mask;
2375 } debopts[] =
2377 #define LEN_AND_STR(str) sizeof (str) - 1, str
2378 { LEN_AND_STR ("libs"), "display library search paths",
2379 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2380 { LEN_AND_STR ("reloc"), "display relocation processing",
2381 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2382 { LEN_AND_STR ("files"), "display progress for input file",
2383 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2384 { LEN_AND_STR ("symbols"), "display symbol table processing",
2385 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2386 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2387 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2388 { LEN_AND_STR ("versions"), "display version dependencies",
2389 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2390 { LEN_AND_STR ("all"), "all previous options combined",
2391 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2392 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2393 { LEN_AND_STR ("statistics"), "display relocation statistics",
2394 DL_DEBUG_STATISTICS },
2395 { LEN_AND_STR ("unused"), "determined unused DSOs",
2396 DL_DEBUG_UNUSED },
2397 { LEN_AND_STR ("help"), "display this help message and exit",
2398 DL_DEBUG_HELP },
2400 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2402 /* Skip separating white spaces and commas. */
2403 while (*dl_debug != '\0')
2405 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2407 size_t cnt;
2408 size_t len = 1;
2410 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2411 && dl_debug[len] != ',' && dl_debug[len] != ':')
2412 ++len;
2414 for (cnt = 0; cnt < ndebopts; ++cnt)
2415 if (debopts[cnt].len == len
2416 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2418 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2419 any_debug = 1;
2420 break;
2423 if (cnt == ndebopts)
2425 /* Display a warning and skip everything until next
2426 separator. */
2427 char *copy = strndupa (dl_debug, len);
2428 _dl_error_printf ("\
2429 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2432 dl_debug += len;
2433 continue;
2436 ++dl_debug;
2439 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2441 size_t cnt;
2443 _dl_printf ("\
2444 Valid options for the LD_DEBUG environment variable are:\n\n");
2446 for (cnt = 0; cnt < ndebopts; ++cnt)
2447 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2448 " " + debopts[cnt].len - 3,
2449 debopts[cnt].helptext);
2451 _dl_printf ("\n\
2452 To direct the debugging output into a file instead of standard output\n\
2453 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2454 _exit (0);
2458 static void
2459 process_dl_audit (char *str)
2461 /* The parameter is a colon separated list of DSO names. */
2462 char *p;
2464 while ((p = (strsep) (&str, ":")) != NULL)
2465 if (p[0] != '\0'
2466 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2467 || strchr (p, '/') == NULL))
2469 /* This is using the local malloc, not the system malloc. The
2470 memory can never be freed. */
2471 struct audit_list *newp = malloc (sizeof (*newp));
2472 newp->name = p;
2474 if (audit_list == NULL)
2475 audit_list = newp->next = newp;
2476 else
2478 newp->next = audit_list->next;
2479 audit_list = audit_list->next = newp;
2484 /* Process all environments variables the dynamic linker must recognize.
2485 Since all of them start with `LD_' we are a bit smarter while finding
2486 all the entries. */
2487 extern char **_environ attribute_hidden;
2490 static void
2491 process_envvars (enum mode *modep)
2493 char **runp = _environ;
2494 char *envline;
2495 enum mode mode = normal;
2496 char *debug_output = NULL;
2498 /* This is the default place for profiling data file. */
2499 GLRO(dl_profile_output)
2500 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2502 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2504 size_t len = 0;
2506 while (envline[len] != '\0' && envline[len] != '=')
2507 ++len;
2509 if (envline[len] != '=')
2510 /* This is a "LD_" variable at the end of the string without
2511 a '=' character. Ignore it since otherwise we will access
2512 invalid memory below. */
2513 continue;
2515 switch (len)
2517 case 4:
2518 /* Warning level, verbose or not. */
2519 if (memcmp (envline, "WARN", 4) == 0)
2520 GLRO(dl_verbose) = envline[5] != '\0';
2521 break;
2523 case 5:
2524 /* Debugging of the dynamic linker? */
2525 if (memcmp (envline, "DEBUG", 5) == 0)
2527 process_dl_debug (&envline[6]);
2528 break;
2530 if (memcmp (envline, "AUDIT", 5) == 0)
2531 process_dl_audit (&envline[6]);
2532 break;
2534 case 7:
2535 /* Print information about versions. */
2536 if (memcmp (envline, "VERBOSE", 7) == 0)
2538 version_info = envline[8] != '\0';
2539 break;
2542 /* List of objects to be preloaded. */
2543 if (memcmp (envline, "PRELOAD", 7) == 0)
2545 preloadlist = &envline[8];
2546 break;
2549 /* Which shared object shall be profiled. */
2550 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2551 GLRO(dl_profile) = &envline[8];
2552 break;
2554 case 8:
2555 /* Do we bind early? */
2556 if (memcmp (envline, "BIND_NOW", 8) == 0)
2558 GLRO(dl_lazy) = envline[9] == '\0';
2559 break;
2561 if (memcmp (envline, "BIND_NOT", 8) == 0)
2562 GLRO(dl_bind_not) = envline[9] != '\0';
2563 break;
2565 case 9:
2566 /* Test whether we want to see the content of the auxiliary
2567 array passed up from the kernel. */
2568 if (!INTUSE(__libc_enable_secure)
2569 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2570 _dl_show_auxv ();
2571 break;
2573 case 10:
2574 /* Mask for the important hardware capabilities. */
2575 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2576 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2577 0, 0);
2578 break;
2580 case 11:
2581 /* Path where the binary is found. */
2582 if (!INTUSE(__libc_enable_secure)
2583 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2584 GLRO(dl_origin_path) = &envline[12];
2585 break;
2587 case 12:
2588 /* The library search path. */
2589 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2591 library_path = &envline[13];
2592 break;
2595 /* Where to place the profiling data file. */
2596 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2598 debug_output = &envline[13];
2599 break;
2602 if (!INTUSE(__libc_enable_secure)
2603 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2604 GLRO(dl_dynamic_weak) = 1;
2605 break;
2607 case 13:
2608 /* We might have some extra environment variable with length 13
2609 to handle. */
2610 #ifdef EXTRA_LD_ENVVARS_13
2611 EXTRA_LD_ENVVARS_13
2612 #endif
2613 if (!INTUSE(__libc_enable_secure)
2614 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2616 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2617 break;
2620 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2621 GLRO(dl_pointer_guard) = envline[14] != '0';
2622 break;
2624 case 14:
2625 /* Where to place the profiling data file. */
2626 if (!INTUSE(__libc_enable_secure)
2627 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2628 && envline[15] != '\0')
2629 GLRO(dl_profile_output) = &envline[15];
2630 break;
2632 case 16:
2633 /* The mode of the dynamic linker can be set. */
2634 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2636 mode = trace;
2637 GLRO(dl_verbose) = 1;
2638 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2639 GLRO(dl_trace_prelink) = &envline[17];
2641 break;
2643 case 20:
2644 /* The mode of the dynamic linker can be set. */
2645 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2646 mode = trace;
2647 break;
2649 /* We might have some extra environment variable to handle. This
2650 is tricky due to the pre-processing of the length of the name
2651 in the switch statement here. The code here assumes that added
2652 environment variables have a different length. */
2653 #ifdef EXTRA_LD_ENVVARS
2654 EXTRA_LD_ENVVARS
2655 #endif
2659 /* The caller wants this information. */
2660 *modep = mode;
2662 /* Extra security for SUID binaries. Remove all dangerous environment
2663 variables. */
2664 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2666 static const char unsecure_envvars[] =
2667 #ifdef EXTRA_UNSECURE_ENVVARS
2668 EXTRA_UNSECURE_ENVVARS
2669 #endif
2670 UNSECURE_ENVVARS;
2671 const char *nextp;
2673 nextp = unsecure_envvars;
2676 unsetenv (nextp);
2677 /* We could use rawmemchr but this need not be fast. */
2678 nextp = (char *) (strchr) (nextp, '\0') + 1;
2680 while (*nextp != '\0');
2682 if (__access ("/etc/suid-debug", F_OK) != 0)
2684 unsetenv ("MALLOC_CHECK_");
2685 GLRO(dl_debug_mask) = 0;
2688 if (mode != normal)
2689 _exit (5);
2691 /* If we have to run the dynamic linker in debugging mode and the
2692 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2693 messages to this file. */
2694 else if (any_debug && debug_output != NULL)
2696 #ifdef O_NOFOLLOW
2697 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2698 #else
2699 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2700 #endif
2701 size_t name_len = strlen (debug_output);
2702 char buf[name_len + 12];
2703 char *startp;
2705 buf[name_len + 11] = '\0';
2706 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2707 *--startp = '.';
2708 startp = memcpy (startp - name_len, debug_output, name_len);
2710 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2711 if (GLRO(dl_debug_fd) == -1)
2712 /* We use standard output if opening the file failed. */
2713 GLRO(dl_debug_fd) = STDOUT_FILENO;
2718 /* Print the various times we collected. */
2719 static void
2720 __attribute ((noinline))
2721 print_statistics (hp_timing_t *rtld_total_timep)
2723 #ifndef HP_TIMING_NONAVAIL
2724 char buf[200];
2725 char *cp;
2726 char *wp;
2728 /* Total time rtld used. */
2729 if (HP_TIMING_AVAIL)
2731 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2732 _dl_debug_printf ("\nruntime linker statistics:\n"
2733 " total startup time in dynamic loader: %s\n", buf);
2735 /* Print relocation statistics. */
2736 char pbuf[30];
2737 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2738 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2739 pbuf + sizeof (pbuf), 10, 0);
2740 wp = pbuf;
2741 switch (pbuf + sizeof (pbuf) - cp)
2743 case 3:
2744 *wp++ = *cp++;
2745 case 2:
2746 *wp++ = *cp++;
2747 case 1:
2748 *wp++ = '.';
2749 *wp++ = *cp++;
2751 *wp = '\0';
2752 _dl_debug_printf ("\
2753 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2755 #endif
2757 unsigned long int num_relative_relocations = 0;
2758 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2760 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2761 continue;
2763 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2765 for (unsigned int i = 0; i < scope->r_nlist; i++)
2767 struct link_map *l = scope->r_list [i];
2769 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2770 num_relative_relocations
2771 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2772 #ifndef ELF_MACHINE_REL_RELATIVE
2773 /* Relative relocations are processed on these architectures if
2774 library is loaded to different address than p_vaddr or
2775 if not prelinked. */
2776 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2777 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2778 #else
2779 /* On e.g. IA-64 or Alpha, relative relocations are processed
2780 only if library is loaded to different address than p_vaddr. */
2781 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2782 #endif
2783 num_relative_relocations
2784 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2788 _dl_debug_printf (" number of relocations: %lu\n"
2789 " number of relocations from cache: %lu\n"
2790 " number of relative relocations: %lu\n",
2791 GL(dl_num_relocations),
2792 GL(dl_num_cache_relocations),
2793 num_relative_relocations);
2795 #ifndef HP_TIMING_NONAVAIL
2796 /* Time spend while loading the object and the dependencies. */
2797 if (HP_TIMING_AVAIL)
2799 char pbuf[30];
2800 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2801 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2802 pbuf + sizeof (pbuf), 10, 0);
2803 wp = pbuf;
2804 switch (pbuf + sizeof (pbuf) - cp)
2806 case 3:
2807 *wp++ = *cp++;
2808 case 2:
2809 *wp++ = *cp++;
2810 case 1:
2811 *wp++ = '.';
2812 *wp++ = *cp++;
2814 *wp = '\0';
2815 _dl_debug_printf ("\
2816 time needed to load objects: %s (%s%%)\n",
2817 buf, pbuf);
2819 #endif