Don't crash when dependencies are missing
[glibc.git] / elf / rtld.c
blob174954bf3bae5f97f55d4c1b49f70415f879d8ab
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2010, 2011 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 #ifndef HAVE_INLINED_SYSCALLS
111 /* Set nonzero during loading and initialization of executable and
112 libraries, cleared before the executable's entry point runs. This
113 must not be initialized to nonzero, because the unused dynamic
114 linker loaded in for libc.so's "ld.so.1" dep will provide the
115 definition seen by libc.so's initializer; that value must be zero,
116 and will be since that dynamic linker's _dl_start and dl_main will
117 never be called. */
118 int _dl_starting_up = 0;
119 INTVARDEF(_dl_starting_up)
120 #endif
122 /* This is the structure which defines all variables global to ld.so
123 (except those which cannot be added for some reason). */
124 struct rtld_global _rtld_global =
126 /* Generally the default presumption without further information is an
127 * executable stack but this is not true for all platforms. */
128 ._dl_stack_flags = DEFAULT_STACK_PERMS,
129 #ifdef _LIBC_REENTRANT
130 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
131 ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
132 #endif
133 ._dl_nns = 1,
134 ._dl_ns =
136 [LM_ID_BASE] = { ._ns_unique_sym_table
137 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
140 /* If we would use strong_alias here the compiler would see a
141 non-hidden definition. This would undo the effect of the previous
142 declaration. So spell out was strong_alias does plus add the
143 visibility attribute. */
144 extern struct rtld_global _rtld_local
145 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
148 /* This variable is similar to _rtld_local, but all values are
149 read-only after relocation. */
150 struct rtld_global_ro _rtld_global_ro attribute_relro =
152 /* Get architecture specific initializer. */
153 #include <dl-procinfo.c>
154 #ifdef NEED_DL_SYSINFO
155 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
156 #endif
157 ._dl_debug_fd = STDERR_FILENO,
158 ._dl_use_load_bias = -2,
159 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
160 ._dl_hwcap_mask = HWCAP_IMPORTANT,
161 ._dl_lazy = 1,
162 ._dl_fpu_control = _FPU_DEFAULT,
163 ._dl_pointer_guard = 1,
165 /* Function pointers. */
166 ._dl_debug_printf = _dl_debug_printf,
167 ._dl_catch_error = _dl_catch_error,
168 ._dl_signal_error = _dl_signal_error,
169 ._dl_mcount = _dl_mcount_internal,
170 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
171 ._dl_check_caller = _dl_check_caller,
172 ._dl_open = _dl_open,
173 ._dl_close = _dl_close,
174 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
175 #ifdef HAVE_DL_DISCOVER_OSVERSION
176 ._dl_discover_osversion = _dl_discover_osversion
177 #endif
179 /* If we would use strong_alias here the compiler would see a
180 non-hidden definition. This would undo the effect of the previous
181 declaration. So spell out was strong_alias does plus add the
182 visibility attribute. */
183 extern struct rtld_global_ro _rtld_local_ro
184 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
187 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
188 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
190 /* These two variables cannot be moved into .data.rel.ro. */
191 static struct libname_list _dl_rtld_libname;
192 static struct libname_list _dl_rtld_libname2;
194 /* We expect less than a second for relocation. */
195 #ifdef HP_SMALL_TIMING_AVAIL
196 # undef HP_TIMING_AVAIL
197 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
198 #endif
200 /* Variable for statistics. */
201 #ifndef HP_TIMING_NONAVAIL
202 static hp_timing_t relocate_time;
203 static hp_timing_t load_time attribute_relro;
204 static hp_timing_t start_time attribute_relro;
205 #endif
207 /* Additional definitions needed by TLS initialization. */
208 #ifdef TLS_INIT_HELPER
209 TLS_INIT_HELPER
210 #endif
212 /* Helper function for syscall implementation. */
213 #ifdef DL_SYSINFO_IMPLEMENTATION
214 DL_SYSINFO_IMPLEMENTATION
215 #endif
217 /* Before ld.so is relocated we must not access variables which need
218 relocations. This means variables which are exported. Variables
219 declared as static are fine. If we can mark a variable hidden this
220 is fine, too. The latter is important here. We can avoid setting
221 up a temporary link map for ld.so if we can mark _rtld_global as
222 hidden. */
223 #ifdef PI_STATIC_AND_HIDDEN
224 # define DONT_USE_BOOTSTRAP_MAP 1
225 #endif
227 #ifdef DONT_USE_BOOTSTRAP_MAP
228 static ElfW(Addr) _dl_start_final (void *arg);
229 #else
230 struct dl_start_final_info
232 struct link_map l;
233 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
234 hp_timing_t start_time;
235 #endif
237 static ElfW(Addr) _dl_start_final (void *arg,
238 struct dl_start_final_info *info);
239 #endif
241 /* These defined magically in the linker script. */
242 extern char _begin[] attribute_hidden;
243 extern char _etext[] attribute_hidden;
244 extern char _end[] attribute_hidden;
247 #ifdef RTLD_START
248 RTLD_START
249 #else
250 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
251 #endif
253 #ifndef VALIDX
254 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
255 + DT_EXTRANUM + DT_VALTAGIDX (tag))
256 #endif
257 #ifndef ADDRIDX
258 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
259 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
260 #endif
262 /* This is the second half of _dl_start (below). It can be inlined safely
263 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
264 references. When the tools don't permit us to avoid using a GOT entry
265 for _dl_rtld_global (no attribute_hidden support), we must make sure
266 this function is not inlined (see below). */
268 #ifdef DONT_USE_BOOTSTRAP_MAP
269 static inline ElfW(Addr) __attribute__ ((always_inline))
270 _dl_start_final (void *arg)
271 #else
272 static ElfW(Addr) __attribute__ ((noinline))
273 _dl_start_final (void *arg, struct dl_start_final_info *info)
274 #endif
276 ElfW(Addr) start_addr;
278 if (HP_TIMING_AVAIL)
280 /* If it hasn't happen yet record the startup time. */
281 if (! HP_TIMING_INLINE)
282 HP_TIMING_NOW (start_time);
283 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
284 else
285 start_time = info->start_time;
286 #endif
288 /* Initialize the timing functions. */
289 HP_TIMING_DIFF_INIT ();
292 /* Transfer data about ourselves to the permanent link_map structure. */
293 #ifndef DONT_USE_BOOTSTRAP_MAP
294 GL(dl_rtld_map).l_addr = info->l.l_addr;
295 GL(dl_rtld_map).l_ld = info->l.l_ld;
296 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
297 sizeof GL(dl_rtld_map).l_info);
298 GL(dl_rtld_map).l_mach = info->l.l_mach;
299 GL(dl_rtld_map).l_relocated = 1;
300 #endif
301 _dl_setup_hash (&GL(dl_rtld_map));
302 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
303 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
304 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
305 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
306 /* Copy the TLS related data if necessary. */
307 #ifndef DONT_USE_BOOTSTRAP_MAP
308 # if USE___THREAD
309 assert (info->l.l_tls_modid != 0);
310 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
311 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
312 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
313 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
314 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
315 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
316 GL(dl_rtld_map).l_tls_modid = 1;
317 # else
318 # if NO_TLS_OFFSET != 0
319 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
320 # endif
321 # endif
323 #endif
325 #if HP_TIMING_AVAIL
326 HP_TIMING_NOW (GL(dl_cpuclock_offset));
327 #endif
329 /* Initialize the stack end variable. */
330 __libc_stack_end = __builtin_frame_address (0);
332 /* Call the OS-dependent function to set up life so we can do things like
333 file access. It will call `dl_main' (below) to do all the real work
334 of the dynamic linker, and then unwind our frame and run the user
335 entry point on the same stack we entered on. */
336 start_addr = _dl_sysdep_start (arg, &dl_main);
338 #ifndef HP_TIMING_NONAVAIL
339 hp_timing_t rtld_total_time;
340 if (HP_TIMING_AVAIL)
342 hp_timing_t end_time;
344 /* Get the current time. */
345 HP_TIMING_NOW (end_time);
347 /* Compute the difference. */
348 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
350 #endif
352 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
354 #ifndef HP_TIMING_NONAVAIL
355 print_statistics (&rtld_total_time);
356 #else
357 print_statistics (NULL);
358 #endif
361 return start_addr;
364 static ElfW(Addr) __attribute_used__ internal_function
365 _dl_start (void *arg)
367 #ifdef DONT_USE_BOOTSTRAP_MAP
368 # define bootstrap_map GL(dl_rtld_map)
369 #else
370 struct dl_start_final_info info;
371 # define bootstrap_map info.l
372 #endif
374 /* This #define produces dynamic linking inline functions for
375 bootstrap relocation instead of general-purpose relocation.
376 Since ld.so must not have any undefined symbols the result
377 is trivial: always the map of ld.so itself. */
378 #define RTLD_BOOTSTRAP
379 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
380 #include "dynamic-link.h"
382 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
383 #ifdef DONT_USE_BOOTSTRAP_MAP
384 HP_TIMING_NOW (start_time);
385 #else
386 HP_TIMING_NOW (info.start_time);
387 #endif
389 /* Partly clean the `bootstrap_map' structure up. Don't use
390 `memset' since it might not be built in or inlined and we cannot
391 make function calls at this point. Use '__builtin_memset' if we
392 know it is available. We do not have to clear the memory if we
393 do not have to use the temporary bootstrap_map. Global variables
394 are initialized to zero by default. */
395 #ifndef DONT_USE_BOOTSTRAP_MAP
396 # ifdef HAVE_BUILTIN_MEMSET
397 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
398 # else
399 for (size_t cnt = 0;
400 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
401 ++cnt)
402 bootstrap_map.l_info[cnt] = 0;
403 # endif
404 # if USE___THREAD
405 bootstrap_map.l_tls_modid = 0;
406 # endif
407 #endif
409 /* Figure out the run-time load address of the dynamic linker itself. */
410 bootstrap_map.l_addr = elf_machine_load_address ();
412 /* Read our own dynamic section and fill in the info array. */
413 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
414 elf_get_dynamic_info (&bootstrap_map, NULL);
416 #if NO_TLS_OFFSET != 0
417 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
418 #endif
420 /* Get the dynamic linker's own program header. First we need the ELF
421 file header. The `_begin' symbol created by the linker script points
422 to it. When we have something like GOTOFF relocs, we can use a plain
423 reference to find the runtime address. Without that, we have to rely
424 on the `l_addr' value, which is not the value we want when prelinked. */
425 #if USE___THREAD
426 dtv_t initdtv[3];
427 ElfW(Ehdr) *ehdr
428 # ifdef DONT_USE_BOOTSTRAP_MAP
429 = (ElfW(Ehdr) *) &_begin;
430 # else
431 # error This will not work with prelink.
432 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
433 # endif
434 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
435 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
436 while (cnt-- > 0)
437 if (phdr[cnt].p_type == PT_TLS)
439 void *tlsblock;
440 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
441 char *p;
443 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
444 bootstrap_map.l_tls_align = phdr[cnt].p_align;
445 if (phdr[cnt].p_align == 0)
446 bootstrap_map.l_tls_firstbyte_offset = 0;
447 else
448 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
449 & (phdr[cnt].p_align - 1));
450 assert (bootstrap_map.l_tls_blocksize != 0);
451 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
452 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
453 + phdr[cnt].p_vaddr);
455 /* We can now allocate the initial TLS block. This can happen
456 on the stack. We'll get the final memory later when we
457 know all about the various objects loaded at startup
458 time. */
459 # if TLS_TCB_AT_TP
460 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
461 TLS_INIT_TCB_ALIGN)
462 + TLS_INIT_TCB_SIZE
463 + max_align);
464 # elif TLS_DTV_AT_TP
465 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
466 bootstrap_map.l_tls_align)
467 + bootstrap_map.l_tls_blocksize
468 + max_align);
469 # else
470 /* In case a model with a different layout for the TCB and DTV
471 is defined add another #elif here and in the following #ifs. */
472 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
473 # endif
474 /* Align the TLS block. */
475 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
476 & ~(max_align - 1));
478 /* Initialize the dtv. [0] is the length, [1] the generation
479 counter. */
480 initdtv[0].counter = 1;
481 initdtv[1].counter = 0;
483 /* Initialize the TLS block. */
484 # if TLS_TCB_AT_TP
485 initdtv[2].pointer = tlsblock;
486 # elif TLS_DTV_AT_TP
487 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
488 bootstrap_map.l_tls_align);
489 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
490 # else
491 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
492 # endif
493 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
494 bootstrap_map.l_tls_initimage_size);
495 # ifdef HAVE_BUILTIN_MEMSET
496 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
497 - bootstrap_map.l_tls_initimage_size));
498 # else
500 size_t remaining = (bootstrap_map.l_tls_blocksize
501 - bootstrap_map.l_tls_initimage_size);
502 while (remaining-- > 0)
503 *p++ = '\0';
505 # endif
507 /* Install the pointer to the dtv. */
509 /* Initialize the thread pointer. */
510 # if TLS_TCB_AT_TP
511 bootstrap_map.l_tls_offset
512 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
514 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
515 initdtv);
517 const char *lossage = TLS_INIT_TP ((char *) tlsblock
518 + bootstrap_map.l_tls_offset, 0);
519 # elif TLS_DTV_AT_TP
520 INSTALL_DTV (tlsblock, initdtv);
521 const char *lossage = TLS_INIT_TP (tlsblock, 0);
522 # else
523 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
524 # endif
525 if (__builtin_expect (lossage != NULL, 0))
526 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
527 lossage);
529 /* So far this is module number one. */
530 bootstrap_map.l_tls_modid = 1;
532 /* There can only be one PT_TLS entry. */
533 break;
535 #endif /* USE___THREAD */
537 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
538 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
539 #endif
541 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
543 /* Relocate ourselves so we can do normal function calls and
544 data access using the global offset table. */
546 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
548 bootstrap_map.l_relocated = 1;
550 /* Please note that we don't allow profiling of this object and
551 therefore need not test whether we have to allocate the array
552 for the relocation results (as done in dl-reloc.c). */
554 /* Now life is sane; we can call functions and access global data.
555 Set up to use the operating system facilities, and find out from
556 the operating system's program loader where to find the program
557 header table in core. Put the rest of _dl_start into a separate
558 function, that way the compiler cannot put accesses to the GOT
559 before ELF_DYNAMIC_RELOCATE. */
561 #ifdef DONT_USE_BOOTSTRAP_MAP
562 ElfW(Addr) entry = _dl_start_final (arg);
563 #else
564 ElfW(Addr) entry = _dl_start_final (arg, &info);
565 #endif
567 #ifndef ELF_MACHINE_START_ADDRESS
568 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
569 #endif
571 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
577 /* Now life is peachy; we can do all normal operations.
578 On to the real work. */
580 /* Some helper functions. */
582 /* Arguments to relocate_doit. */
583 struct relocate_args
585 struct link_map *l;
586 int reloc_mode;
589 struct map_args
591 /* Argument to map_doit. */
592 char *str;
593 struct link_map *loader;
594 int mode;
595 /* Return value of map_doit. */
596 struct link_map *map;
599 struct dlmopen_args
601 const char *fname;
602 struct link_map *map;
605 struct lookup_args
607 const char *name;
608 struct link_map *map;
609 void *result;
612 /* Arguments to version_check_doit. */
613 struct version_check_args
615 int doexit;
616 int dotrace;
619 static void
620 relocate_doit (void *a)
622 struct relocate_args *args = (struct relocate_args *) a;
624 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
627 static void
628 map_doit (void *a)
630 struct map_args *args = (struct map_args *) a;
631 args->map = _dl_map_object (args->loader, args->str, lt_library, 0,
632 args->mode, LM_ID_BASE);
635 static void
636 dlmopen_doit (void *a)
638 struct dlmopen_args *args = (struct dlmopen_args *) a;
639 args->map = _dl_open (args->fname,
640 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
641 | __RTLD_SECURE),
642 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
643 __environ);
646 static void
647 lookup_doit (void *a)
649 struct lookup_args *args = (struct lookup_args *) a;
650 const ElfW(Sym) *ref = NULL;
651 args->result = NULL;
652 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
653 args->map->l_local_scope, NULL, 0,
654 DL_LOOKUP_RETURN_NEWEST, NULL);
655 if (ref != NULL)
656 args->result = DL_SYMBOL_ADDRESS (l, ref);
659 static void
660 version_check_doit (void *a)
662 struct version_check_args *args = (struct version_check_args *) a;
663 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
664 args->dotrace) && args->doexit)
665 /* We cannot start the application. Abort now. */
666 _exit (1);
670 static inline struct link_map *
671 find_needed (const char *name)
673 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
674 unsigned int n = scope->r_nlist;
676 while (n-- > 0)
677 if (_dl_name_match_p (name, scope->r_list[n]))
678 return scope->r_list[n];
680 /* Should never happen. */
681 return NULL;
684 static int
685 match_version (const char *string, struct link_map *map)
687 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
688 ElfW(Verdef) *def;
690 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
691 if (map->l_info[VERDEFTAG] == NULL)
692 /* The file has no symbol versioning. */
693 return 0;
695 def = (ElfW(Verdef) *) ((char *) map->l_addr
696 + map->l_info[VERDEFTAG]->d_un.d_ptr);
697 while (1)
699 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
701 /* Compare the version strings. */
702 if (strcmp (string, strtab + aux->vda_name) == 0)
703 /* Bingo! */
704 return 1;
706 /* If no more definitions we failed to find what we want. */
707 if (def->vd_next == 0)
708 break;
710 /* Next definition. */
711 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
714 return 0;
717 static bool tls_init_tp_called;
719 static void *
720 init_tls (void)
722 /* Number of elements in the static TLS block. */
723 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
725 /* Do not do this twice. The audit interface might have required
726 the DTV interfaces to be set up early. */
727 if (GL(dl_initial_dtv) != NULL)
728 return NULL;
730 /* Allocate the array which contains the information about the
731 dtv slots. We allocate a few entries more than needed to
732 avoid the need for reallocation. */
733 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
735 /* Allocate. */
736 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
737 calloc (sizeof (struct dtv_slotinfo_list)
738 + nelem * sizeof (struct dtv_slotinfo), 1);
739 /* No need to check the return value. If memory allocation failed
740 the program would have been terminated. */
742 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
743 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
744 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
746 /* Fill in the information from the loaded modules. No namespace
747 but the base one can be filled at this time. */
748 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
749 int i = 0;
750 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
751 l = l->l_next)
752 if (l->l_tls_blocksize != 0)
754 /* This is a module with TLS data. Store the map reference.
755 The generation counter is zero. */
756 slotinfo[i].map = l;
757 /* slotinfo[i].gen = 0; */
758 ++i;
760 assert (i == GL(dl_tls_max_dtv_idx));
762 /* Compute the TLS offsets for the various blocks. */
763 _dl_determine_tlsoffset ();
765 /* Construct the static TLS block and the dtv for the initial
766 thread. For some platforms this will include allocating memory
767 for the thread descriptor. The memory for the TLS block will
768 never be freed. It should be allocated accordingly. The dtv
769 array can be changed if dynamic loading requires it. */
770 void *tcbp = _dl_allocate_tls_storage ();
771 if (tcbp == NULL)
772 _dl_fatal_printf ("\
773 cannot allocate TLS data structures for initial thread");
775 /* Store for detection of the special case by __tls_get_addr
776 so it knows not to pass this dtv to the normal realloc. */
777 GL(dl_initial_dtv) = GET_DTV (tcbp);
779 /* And finally install it for the main thread. If ld.so itself uses
780 TLS we know the thread pointer was initialized earlier. */
781 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
782 if (__builtin_expect (lossage != NULL, 0))
783 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
784 tls_init_tp_called = true;
786 return tcbp;
789 #ifdef _LIBC_REENTRANT
790 /* _dl_error_catch_tsd points to this for the single-threaded case.
791 It's reset by the thread library for multithreaded programs. */
792 void ** __attribute__ ((const))
793 _dl_initial_error_catch_tsd (void)
795 static void *data;
796 return &data;
798 #endif
801 static unsigned int
802 do_preload (char *fname, struct link_map *main_map, const char *where)
804 const char *objname;
805 const char *err_str = NULL;
806 struct map_args args;
807 bool malloced;
809 args.str = fname;
810 args.loader = main_map;
811 args.mode = __RTLD_SECURE;
813 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
815 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
816 if (__builtin_expect (err_str != NULL, 0))
818 _dl_error_printf ("\
819 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
820 fname, where);
821 /* No need to call free, this is still before
822 the libc's malloc is used. */
824 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
825 /* It is no duplicate. */
826 return 1;
828 /* Nothing loaded. */
829 return 0;
832 #if defined SHARED && defined _LIBC_REENTRANT \
833 && defined __rtld_lock_default_lock_recursive
834 static void
835 rtld_lock_default_lock_recursive (void *lock)
837 __rtld_lock_default_lock_recursive (lock);
840 static void
841 rtld_lock_default_unlock_recursive (void *lock)
843 __rtld_lock_default_unlock_recursive (lock);
845 #endif
848 static void
849 security_init (void)
851 /* Set up the stack checker's canary. */
852 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
853 #ifdef THREAD_SET_STACK_GUARD
854 THREAD_SET_STACK_GUARD (stack_chk_guard);
855 #else
856 __stack_chk_guard = stack_chk_guard;
857 #endif
859 /* Set up the pointer guard as well, if necessary. */
860 if (GLRO(dl_pointer_guard))
862 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
863 stack_chk_guard);
864 #ifdef THREAD_SET_POINTER_GUARD
865 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
866 #endif
867 __pointer_chk_guard_local = pointer_chk_guard;
870 /* We do not need the _dl_random value anymore. The less
871 information we leave behind, the better, so clear the
872 variable. */
873 _dl_random = NULL;
877 /* The library search path. */
878 static const char *library_path attribute_relro;
879 /* The list preloaded objects. */
880 static const char *preloadlist attribute_relro;
881 /* Nonzero if information about versions has to be printed. */
882 static int version_info attribute_relro;
884 static void
885 dl_main (const ElfW(Phdr) *phdr,
886 ElfW(Word) phnum,
887 ElfW(Addr) *user_entry,
888 ElfW(auxv_t) *auxv)
890 const ElfW(Phdr) *ph;
891 enum mode mode;
892 struct link_map *main_map;
893 size_t file_size;
894 char *file;
895 bool has_interp = false;
896 unsigned int i;
897 bool prelinked = false;
898 bool rtld_is_main = false;
899 #ifndef HP_TIMING_NONAVAIL
900 hp_timing_t start;
901 hp_timing_t stop;
902 hp_timing_t diff;
903 #endif
904 void *tcbp = NULL;
906 #ifdef _LIBC_REENTRANT
907 /* Explicit initialization since the reloc would just be more work. */
908 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
909 #endif
911 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
913 #if defined SHARED && defined _LIBC_REENTRANT \
914 && defined __rtld_lock_default_lock_recursive
915 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
916 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
917 #endif
919 /* The explicit initialization here is cheaper than processing the reloc
920 in the _rtld_local definition's initializer. */
921 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
923 /* Process the environment variable which control the behaviour. */
924 process_envvars (&mode);
926 #ifndef HAVE_INLINED_SYSCALLS
927 /* Set up a flag which tells we are just starting. */
928 INTUSE(_dl_starting_up) = 1;
929 #endif
931 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
933 /* Ho ho. We are not the program interpreter! We are the program
934 itself! This means someone ran ld.so as a command. Well, that
935 might be convenient to do sometimes. We support it by
936 interpreting the args like this:
938 ld.so PROGRAM ARGS...
940 The first argument is the name of a file containing an ELF
941 executable we will load and run with the following arguments.
942 To simplify life here, PROGRAM is searched for using the
943 normal rules for shared objects, rather than $PATH or anything
944 like that. We just load it and use its entry point; we don't
945 pay attention to its PT_INTERP command (we are the interpreter
946 ourselves). This is an easy way to test a new ld.so before
947 installing it. */
948 rtld_is_main = true;
950 /* Note the place where the dynamic linker actually came from. */
951 GL(dl_rtld_map).l_name = rtld_progname;
953 while (_dl_argc > 1)
954 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
956 mode = list;
957 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
959 ++_dl_skip_args;
960 --_dl_argc;
961 ++INTUSE(_dl_argv);
963 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
965 mode = verify;
967 ++_dl_skip_args;
968 --_dl_argc;
969 ++INTUSE(_dl_argv);
971 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
972 && _dl_argc > 2)
974 library_path = INTUSE(_dl_argv)[2];
976 _dl_skip_args += 2;
977 _dl_argc -= 2;
978 INTUSE(_dl_argv) += 2;
980 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
981 && _dl_argc > 2)
983 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
985 _dl_skip_args += 2;
986 _dl_argc -= 2;
987 INTUSE(_dl_argv) += 2;
989 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
991 process_dl_audit (INTUSE(_dl_argv)[2]);
993 _dl_skip_args += 2;
994 _dl_argc -= 2;
995 INTUSE(_dl_argv) += 2;
997 else
998 break;
1000 /* If we have no further argument the program was called incorrectly.
1001 Grant the user some education. */
1002 if (_dl_argc < 2)
1003 _dl_fatal_printf ("\
1004 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1005 You have invoked `ld.so', the helper program for shared library executables.\n\
1006 This program usually lives in the file `/lib/ld.so', and special directives\n\
1007 in executable files using ELF shared libraries tell the system's program\n\
1008 loader to load the helper program from this file. This helper program loads\n\
1009 the shared libraries needed by the program executable, prepares the program\n\
1010 to run, and runs it. You may invoke this helper program directly from the\n\
1011 command line to load and run an ELF executable file; this is like executing\n\
1012 that file itself, but always uses this helper program from the file you\n\
1013 specified, instead of the helper program file specified in the executable\n\
1014 file you run. This is mostly of use for maintainers to test new versions\n\
1015 of this helper program; chances are you did not intend to run this program.\n\
1017 --list list all dependencies and how they are resolved\n\
1018 --verify verify that given object really is a dynamically linked\n\
1019 object we can handle\n\
1020 --library-path PATH use given PATH instead of content of the environment\n\
1021 variable LD_LIBRARY_PATH\n\
1022 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1023 in LIST\n\
1024 --audit LIST use objects named in LIST as auditors\n");
1026 ++_dl_skip_args;
1027 --_dl_argc;
1028 ++INTUSE(_dl_argv);
1030 /* The initialization of _dl_stack_flags done below assumes the
1031 executable's PT_GNU_STACK may have been honored by the kernel, and
1032 so a PT_GNU_STACK with PF_X set means the stack started out with
1033 execute permission. However, this is not really true if the
1034 dynamic linker is the executable the kernel loaded. For this
1035 case, we must reinitialize _dl_stack_flags to match the dynamic
1036 linker itself. If the dynamic linker was built with a
1037 PT_GNU_STACK, then the kernel may have loaded us with a
1038 nonexecutable stack that we will have to make executable when we
1039 load the program below unless it has a PT_GNU_STACK indicating
1040 nonexecutable stack is ok. */
1042 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1043 if (ph->p_type == PT_GNU_STACK)
1045 GL(dl_stack_flags) = ph->p_flags;
1046 break;
1049 if (__builtin_expect (mode, normal) == verify)
1051 const char *objname;
1052 const char *err_str = NULL;
1053 struct map_args args;
1054 bool malloced;
1056 args.str = rtld_progname;
1057 args.loader = NULL;
1058 args.mode = __RTLD_OPENEXEC;
1059 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1060 &args);
1061 if (__builtin_expect (err_str != NULL, 0))
1062 /* We don't free the returned string, the programs stops
1063 anyway. */
1064 _exit (EXIT_FAILURE);
1066 else
1068 HP_TIMING_NOW (start);
1069 _dl_map_object (NULL, rtld_progname, lt_library, 0,
1070 __RTLD_OPENEXEC, LM_ID_BASE);
1071 HP_TIMING_NOW (stop);
1073 HP_TIMING_DIFF (load_time, start, stop);
1076 /* Now the map for the main executable is available. */
1077 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1079 phdr = main_map->l_phdr;
1080 phnum = main_map->l_phnum;
1081 /* We overwrite here a pointer to a malloc()ed string. But since
1082 the malloc() implementation used at this point is the dummy
1083 implementations which has no real free() function it does not
1084 makes sense to free the old string first. */
1085 main_map->l_name = (char *) "";
1086 *user_entry = main_map->l_entry;
1088 #ifdef HAVE_AUX_VECTOR
1089 /* Adjust the on-stack auxiliary vector so that it looks like the
1090 binary was executed directly. */
1091 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1092 switch (av->a_type)
1094 case AT_PHDR:
1095 av->a_un.a_val = (uintptr_t) phdr;
1096 break;
1097 case AT_PHNUM:
1098 av->a_un.a_val = phnum;
1099 break;
1100 case AT_ENTRY:
1101 av->a_un.a_val = *user_entry;
1102 break;
1104 #endif
1106 else
1108 /* Create a link_map for the executable itself.
1109 This will be what dlopen on "" returns. */
1110 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1111 __RTLD_OPENEXEC, LM_ID_BASE);
1112 assert (main_map != NULL);
1113 main_map->l_phdr = phdr;
1114 main_map->l_phnum = phnum;
1115 main_map->l_entry = *user_entry;
1117 /* Even though the link map is not yet fully initialized we can add
1118 it to the map list since there are no possible users running yet. */
1119 _dl_add_to_namespace_list (main_map, LM_ID_BASE);
1120 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1122 /* At this point we are in a bit of trouble. We would have to
1123 fill in the values for l_dev and l_ino. But in general we
1124 do not know where the file is. We also do not handle AT_EXECFD
1125 even if it would be passed up.
1127 We leave the values here defined to 0. This is normally no
1128 problem as the program code itself is normally no shared
1129 object and therefore cannot be loaded dynamically. Nothing
1130 prevent the use of dynamic binaries and in these situations
1131 we might get problems. We might not be able to find out
1132 whether the object is already loaded. But since there is no
1133 easy way out and because the dynamic binary must also not
1134 have an SONAME we ignore this program for now. If it becomes
1135 a problem we can force people using SONAMEs. */
1137 /* We delay initializing the path structure until we got the dynamic
1138 information for the program. */
1141 main_map->l_map_end = 0;
1142 main_map->l_text_end = 0;
1143 /* Perhaps the executable has no PT_LOAD header entries at all. */
1144 main_map->l_map_start = ~0;
1145 /* And it was opened directly. */
1146 ++main_map->l_direct_opencount;
1148 /* Scan the program header table for the dynamic section. */
1149 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1150 switch (ph->p_type)
1152 case PT_PHDR:
1153 /* Find out the load address. */
1154 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1155 break;
1156 case PT_DYNAMIC:
1157 /* This tells us where to find the dynamic section,
1158 which tells us everything we need to do. */
1159 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1160 break;
1161 case PT_INTERP:
1162 /* This "interpreter segment" was used by the program loader to
1163 find the program interpreter, which is this program itself, the
1164 dynamic linker. We note what name finds us, so that a future
1165 dlopen call or DT_NEEDED entry, for something that wants to link
1166 against the dynamic linker as a shared library, will know that
1167 the shared object is already loaded. */
1168 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1169 + ph->p_vaddr);
1170 /* _dl_rtld_libname.next = NULL; Already zero. */
1171 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1173 /* Ordinarilly, we would get additional names for the loader from
1174 our DT_SONAME. This can't happen if we were actually linked as
1175 a static executable (detect this case when we have no DYNAMIC).
1176 If so, assume the filename component of the interpreter path to
1177 be our SONAME, and add it to our name list. */
1178 if (GL(dl_rtld_map).l_ld == NULL)
1180 const char *p = NULL;
1181 const char *cp = _dl_rtld_libname.name;
1183 /* Find the filename part of the path. */
1184 while (*cp != '\0')
1185 if (*cp++ == '/')
1186 p = cp;
1188 if (p != NULL)
1190 _dl_rtld_libname2.name = p;
1191 /* _dl_rtld_libname2.next = NULL; Already zero. */
1192 _dl_rtld_libname.next = &_dl_rtld_libname2;
1196 has_interp = true;
1197 break;
1198 case PT_LOAD:
1200 ElfW(Addr) mapstart;
1201 ElfW(Addr) allocend;
1203 /* Remember where the main program starts in memory. */
1204 mapstart = (main_map->l_addr
1205 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1206 if (main_map->l_map_start > mapstart)
1207 main_map->l_map_start = mapstart;
1209 /* Also where it ends. */
1210 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1211 if (main_map->l_map_end < allocend)
1212 main_map->l_map_end = allocend;
1213 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1214 main_map->l_text_end = allocend;
1216 break;
1218 case PT_TLS:
1219 if (ph->p_memsz > 0)
1221 /* Note that in the case the dynamic linker we duplicate work
1222 here since we read the PT_TLS entry already in
1223 _dl_start_final. But the result is repeatable so do not
1224 check for this special but unimportant case. */
1225 main_map->l_tls_blocksize = ph->p_memsz;
1226 main_map->l_tls_align = ph->p_align;
1227 if (ph->p_align == 0)
1228 main_map->l_tls_firstbyte_offset = 0;
1229 else
1230 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1231 & (ph->p_align - 1));
1232 main_map->l_tls_initimage_size = ph->p_filesz;
1233 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1235 /* This image gets the ID one. */
1236 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1238 break;
1240 case PT_GNU_STACK:
1241 GL(dl_stack_flags) = ph->p_flags;
1242 break;
1244 case PT_GNU_RELRO:
1245 main_map->l_relro_addr = ph->p_vaddr;
1246 main_map->l_relro_size = ph->p_memsz;
1247 break;
1250 /* Adjust the address of the TLS initialization image in case
1251 the executable is actually an ET_DYN object. */
1252 if (main_map->l_tls_initimage != NULL)
1253 main_map->l_tls_initimage
1254 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1255 if (! main_map->l_map_end)
1256 main_map->l_map_end = ~0;
1257 if (! main_map->l_text_end)
1258 main_map->l_text_end = ~0;
1259 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1261 /* We were invoked directly, so the program might not have a
1262 PT_INTERP. */
1263 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1264 /* _dl_rtld_libname.next = NULL; Already zero. */
1265 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1267 else
1268 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1270 /* If the current libname is different from the SONAME, add the
1271 latter as well. */
1272 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1273 && strcmp (GL(dl_rtld_map).l_libname->name,
1274 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1275 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1277 static struct libname_list newname;
1278 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1279 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1280 newname.next = NULL;
1281 newname.dont_free = 1;
1283 assert (GL(dl_rtld_map).l_libname->next == NULL);
1284 GL(dl_rtld_map).l_libname->next = &newname;
1286 /* The ld.so must be relocated since otherwise loading audit modules
1287 will fail since they reuse the very same ld.so. */
1288 assert (GL(dl_rtld_map).l_relocated);
1290 if (! rtld_is_main)
1292 /* Extract the contents of the dynamic section for easy access. */
1293 elf_get_dynamic_info (main_map, NULL);
1294 /* Set up our cache of pointers into the hash table. */
1295 _dl_setup_hash (main_map);
1298 if (__builtin_expect (mode, normal) == verify)
1300 /* We were called just to verify that this is a dynamic
1301 executable using us as the program interpreter. Exit with an
1302 error if we were not able to load the binary or no interpreter
1303 is specified (i.e., this is no dynamically linked binary. */
1304 if (main_map->l_ld == NULL)
1305 _exit (1);
1307 /* We allow here some platform specific code. */
1308 #ifdef DISTINGUISH_LIB_VERSIONS
1309 DISTINGUISH_LIB_VERSIONS;
1310 #endif
1311 _exit (has_interp ? 0 : 2);
1314 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1315 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1316 /* Set up the data structures for the system-supplied DSO early,
1317 so they can influence _dl_init_paths. */
1318 if (GLRO(dl_sysinfo_dso) != NULL)
1320 /* Do an abridged version of the work _dl_map_object_from_fd would do
1321 to map in the object. It's already mapped and prelinked (and
1322 better be, since it's read-only and so we couldn't relocate it).
1323 We just want our data structures to describe it as if we had just
1324 mapped and relocated it normally. */
1325 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1326 0, LM_ID_BASE);
1327 if (__builtin_expect (l != NULL, 1))
1329 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1331 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1332 + GLRO(dl_sysinfo_dso)->e_phoff);
1333 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1334 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1336 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1337 if (ph->p_type == PT_DYNAMIC)
1339 l->l_ld = (void *) ph->p_vaddr;
1340 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1342 else if (ph->p_type == PT_LOAD)
1344 if (! l->l_addr)
1345 l->l_addr = ph->p_vaddr;
1346 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1347 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1348 if ((ph->p_flags & PF_X)
1349 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1350 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1352 else
1353 /* There must be no TLS segment. */
1354 assert (ph->p_type != PT_TLS);
1356 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1357 l->l_addr = l->l_map_start - l->l_addr;
1358 l->l_map_end += l->l_addr;
1359 l->l_text_end += l->l_addr;
1360 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1361 elf_get_dynamic_info (l, dyn_temp);
1362 _dl_setup_hash (l);
1363 l->l_relocated = 1;
1365 /* Initialize l_local_scope to contain just this map. This allows
1366 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1367 So we create a single entry list pointing to l_real as its only
1368 element */
1369 l->l_local_scope[0]->r_nlist = 1;
1370 l->l_local_scope[0]->r_list = &l->l_real;
1372 /* Now that we have the info handy, use the DSO image's soname
1373 so this object can be looked up by name. Note that we do not
1374 set l_name here. That field gives the file name of the DSO,
1375 and this DSO is not associated with any file. */
1376 if (l->l_info[DT_SONAME] != NULL)
1378 /* Work around a kernel problem. The kernel cannot handle
1379 addresses in the vsyscall DSO pages in writev() calls. */
1380 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1381 + l->l_info[DT_SONAME]->d_un.d_val);
1382 size_t len = strlen (dsoname);
1383 char *copy = malloc (len);
1384 if (copy == NULL)
1385 _dl_fatal_printf ("out of memory\n");
1386 l->l_libname->name = memcpy (copy, dsoname, len);
1389 /* Add the vDSO to the object list. */
1390 _dl_add_to_namespace_list (l, LM_ID_BASE);
1392 /* Rearrange the list so this DSO appears after rtld_map. */
1393 assert (l->l_next == NULL);
1394 assert (l->l_prev == main_map);
1395 GL(dl_rtld_map).l_next = l;
1396 l->l_prev = &GL(dl_rtld_map);
1397 first_preload = &l->l_next;
1399 /* We have a prelinked DSO preloaded by the system. */
1400 GLRO(dl_sysinfo_map) = l;
1401 # ifdef NEED_DL_SYSINFO
1402 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1403 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1404 # endif
1407 #endif
1409 #ifdef DL_SYSDEP_OSCHECK
1410 DL_SYSDEP_OSCHECK (dl_fatal);
1411 #endif
1413 /* Initialize the data structures for the search paths for shared
1414 objects. */
1415 _dl_init_paths (library_path);
1417 /* Initialize _r_debug. */
1418 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1419 LM_ID_BASE);
1420 r->r_state = RT_CONSISTENT;
1422 /* Put the link_map for ourselves on the chain so it can be found by
1423 name. Note that at this point the global chain of link maps contains
1424 exactly one element, which is pointed to by dl_loaded. */
1425 if (! GL(dl_rtld_map).l_name)
1426 /* If not invoked directly, the dynamic linker shared object file was
1427 found by the PT_INTERP name. */
1428 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1429 GL(dl_rtld_map).l_type = lt_library;
1430 main_map->l_next = &GL(dl_rtld_map);
1431 GL(dl_rtld_map).l_prev = main_map;
1432 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1433 ++GL(dl_load_adds);
1435 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1436 to not using bias for non-prelinked PIEs and libraries
1437 and using it for executables or prelinked PIEs or libraries. */
1438 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1439 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1441 /* Set up the program header information for the dynamic linker
1442 itself. It is needed in the dl_iterate_phdr() callbacks. */
1443 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1444 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1445 + rtld_ehdr->e_phoff);
1446 GL(dl_rtld_map).l_phdr = rtld_phdr;
1447 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1450 /* PT_GNU_RELRO is usually the last phdr. */
1451 size_t cnt = rtld_ehdr->e_phnum;
1452 while (cnt-- > 0)
1453 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1455 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1456 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1457 break;
1460 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1461 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1462 /* Assign a module ID. Do this before loading any audit modules. */
1463 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1465 /* If we have auditing DSOs to load, do it now. */
1466 if (__builtin_expect (audit_list != NULL, 0))
1468 /* Iterate over all entries in the list. The order is important. */
1469 struct audit_ifaces *last_audit = NULL;
1470 struct audit_list *al = audit_list->next;
1472 /* Since we start using the auditing DSOs right away we need to
1473 initialize the data structures now. */
1474 tcbp = init_tls ();
1476 /* Initialize security features. We need to do it this early
1477 since otherwise the constructors of the audit libraries will
1478 use different values (especially the pointer guard) and will
1479 fail later on. */
1480 security_init ();
1484 int tls_idx = GL(dl_tls_max_dtv_idx);
1486 /* Now it is time to determine the layout of the static TLS
1487 block and allocate it for the initial thread. Note that we
1488 always allocate the static block, we never defer it even if
1489 no DF_STATIC_TLS bit is set. The reason is that we know
1490 glibc will use the static model. */
1491 struct dlmopen_args dlmargs;
1492 dlmargs.fname = al->name;
1493 dlmargs.map = NULL;
1495 const char *objname;
1496 const char *err_str = NULL;
1497 bool malloced;
1498 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1499 &dlmargs);
1500 if (__builtin_expect (err_str != NULL, 0))
1502 not_loaded:
1503 _dl_error_printf ("\
1504 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1505 al->name, err_str);
1506 if (malloced)
1507 free ((char *) err_str);
1509 else
1511 struct lookup_args largs;
1512 largs.name = "la_version";
1513 largs.map = dlmargs.map;
1515 /* Check whether the interface version matches. */
1516 (void) _dl_catch_error (&objname, &err_str, &malloced,
1517 lookup_doit, &largs);
1519 unsigned int (*laversion) (unsigned int);
1520 unsigned int lav;
1521 if (err_str == NULL
1522 && (laversion = largs.result) != NULL
1523 && (lav = laversion (LAV_CURRENT)) > 0
1524 && lav <= LAV_CURRENT)
1526 /* Allocate structure for the callback function pointers.
1527 This call can never fail. */
1528 union
1530 struct audit_ifaces ifaces;
1531 #define naudit_ifaces 8
1532 void (*fptr[naudit_ifaces]) (void);
1533 } *newp = malloc (sizeof (*newp));
1535 /* Names of the auditing interfaces. All in one
1536 long string. */
1537 static const char audit_iface_names[] =
1538 "la_activity\0"
1539 "la_objsearch\0"
1540 "la_objopen\0"
1541 "la_preinit\0"
1542 #if __ELF_NATIVE_CLASS == 32
1543 "la_symbind32\0"
1544 #elif __ELF_NATIVE_CLASS == 64
1545 "la_symbind64\0"
1546 #else
1547 # error "__ELF_NATIVE_CLASS must be defined"
1548 #endif
1549 #define STRING(s) __STRING (s)
1550 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1551 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1552 "la_objclose\0";
1553 unsigned int cnt = 0;
1554 const char *cp = audit_iface_names;
1557 largs.name = cp;
1558 (void) _dl_catch_error (&objname, &err_str, &malloced,
1559 lookup_doit, &largs);
1561 /* Store the pointer. */
1562 if (err_str == NULL && largs.result != NULL)
1564 newp->fptr[cnt] = largs.result;
1566 /* The dynamic linker link map is statically
1567 allocated, initialize the data now. */
1568 GL(dl_rtld_map).l_audit[cnt].cookie
1569 = (intptr_t) &GL(dl_rtld_map);
1571 else
1572 newp->fptr[cnt] = NULL;
1573 ++cnt;
1575 cp = (char *) rawmemchr (cp, '\0') + 1;
1577 while (*cp != '\0');
1578 assert (cnt == naudit_ifaces);
1580 /* Now append the new auditing interface to the list. */
1581 newp->ifaces.next = NULL;
1582 if (last_audit == NULL)
1583 last_audit = GLRO(dl_audit) = &newp->ifaces;
1584 else
1585 last_audit = last_audit->next = &newp->ifaces;
1586 ++GLRO(dl_naudit);
1588 /* Mark the DSO as being used for auditing. */
1589 dlmargs.map->l_auditing = 1;
1591 else
1593 /* We cannot use the DSO, it does not have the
1594 appropriate interfaces or it expects something
1595 more recent. */
1596 #ifndef NDEBUG
1597 Lmid_t ns = dlmargs.map->l_ns;
1598 #endif
1599 _dl_close (dlmargs.map);
1601 /* Make sure the namespace has been cleared entirely. */
1602 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1603 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1605 GL(dl_tls_max_dtv_idx) = tls_idx;
1606 goto not_loaded;
1610 al = al->next;
1612 while (al != audit_list->next);
1614 /* If we have any auditing modules, announce that we already
1615 have two objects loaded. */
1616 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1618 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1620 for (unsigned int outer = 0; outer < 2; ++outer)
1622 struct audit_ifaces *afct = GLRO(dl_audit);
1623 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1625 if (afct->objopen != NULL)
1627 ls[outer]->l_audit[cnt].bindflags
1628 = afct->objopen (ls[outer], LM_ID_BASE,
1629 &ls[outer]->l_audit[cnt].cookie);
1631 ls[outer]->l_audit_any_plt
1632 |= ls[outer]->l_audit[cnt].bindflags != 0;
1635 afct = afct->next;
1641 /* Set up debugging before the debugger is notified for the first time. */
1642 #ifdef ELF_MACHINE_DEBUG_SETUP
1643 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1644 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1645 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1646 #else
1647 if (main_map->l_info[DT_DEBUG] != NULL)
1648 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1649 with the run-time address of the r_debug structure */
1650 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1652 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1653 case you run gdb on the dynamic linker directly. */
1654 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1655 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1656 #endif
1658 /* We start adding objects. */
1659 r->r_state = RT_ADD;
1660 _dl_debug_state ();
1662 /* Auditing checkpoint: we are ready to signal that the initial map
1663 is being constructed. */
1664 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1666 struct audit_ifaces *afct = GLRO(dl_audit);
1667 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1669 if (afct->activity != NULL)
1670 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1672 afct = afct->next;
1676 /* We have two ways to specify objects to preload: via environment
1677 variable and via the file /etc/ld.so.preload. The latter can also
1678 be used when security is enabled. */
1679 assert (*first_preload == NULL);
1680 struct link_map **preloads = NULL;
1681 unsigned int npreloads = 0;
1683 if (__builtin_expect (preloadlist != NULL, 0))
1685 /* The LD_PRELOAD environment variable gives list of libraries
1686 separated by white space or colons that are loaded before the
1687 executable's dependencies and prepended to the global scope
1688 list. If the binary is running setuid all elements
1689 containing a '/' are ignored since it is insecure. */
1690 char *list = strdupa (preloadlist);
1691 char *p;
1693 HP_TIMING_NOW (start);
1695 /* Prevent optimizing strsep. Speed is not important here. */
1696 while ((p = (strsep) (&list, " :")) != NULL)
1697 if (p[0] != '\0'
1698 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1699 || strchr (p, '/') == NULL))
1700 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1702 HP_TIMING_NOW (stop);
1703 HP_TIMING_DIFF (diff, start, stop);
1704 HP_TIMING_ACCUM_NT (load_time, diff);
1707 /* There usually is no ld.so.preload file, it should only be used
1708 for emergencies and testing. So the open call etc should usually
1709 fail. Using access() on a non-existing file is faster than using
1710 open(). So we do this first. If it succeeds we do almost twice
1711 the work but this does not matter, since it is not for production
1712 use. */
1713 static const char preload_file[] = "/etc/ld.so.preload";
1714 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1716 /* Read the contents of the file. */
1717 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1718 PROT_READ | PROT_WRITE);
1719 if (__builtin_expect (file != MAP_FAILED, 0))
1721 /* Parse the file. It contains names of libraries to be loaded,
1722 separated by white spaces or `:'. It may also contain
1723 comments introduced by `#'. */
1724 char *problem;
1725 char *runp;
1726 size_t rest;
1728 /* Eliminate comments. */
1729 runp = file;
1730 rest = file_size;
1731 while (rest > 0)
1733 char *comment = memchr (runp, '#', rest);
1734 if (comment == NULL)
1735 break;
1737 rest -= comment - runp;
1739 *comment = ' ';
1740 while (--rest > 0 && *++comment != '\n');
1743 /* We have one problematic case: if we have a name at the end of
1744 the file without a trailing terminating characters, we cannot
1745 place the \0. Handle the case separately. */
1746 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1747 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1749 problem = &file[file_size];
1750 while (problem > file && problem[-1] != ' '
1751 && problem[-1] != '\t'
1752 && problem[-1] != '\n' && problem[-1] != ':')
1753 --problem;
1755 if (problem > file)
1756 problem[-1] = '\0';
1758 else
1760 problem = NULL;
1761 file[file_size - 1] = '\0';
1764 HP_TIMING_NOW (start);
1766 if (file != problem)
1768 char *p;
1769 runp = file;
1770 while ((p = strsep (&runp, ": \t\n")) != NULL)
1771 if (p[0] != '\0')
1772 npreloads += do_preload (p, main_map, preload_file);
1775 if (problem != NULL)
1777 char *p = strndupa (problem, file_size - (problem - file));
1779 npreloads += do_preload (p, main_map, preload_file);
1782 HP_TIMING_NOW (stop);
1783 HP_TIMING_DIFF (diff, start, stop);
1784 HP_TIMING_ACCUM_NT (load_time, diff);
1786 /* We don't need the file anymore. */
1787 __munmap (file, file_size);
1791 if (__builtin_expect (*first_preload != NULL, 0))
1793 /* Set up PRELOADS with a vector of the preloaded libraries. */
1794 struct link_map *l = *first_preload;
1795 preloads = __alloca (npreloads * sizeof preloads[0]);
1796 i = 0;
1799 preloads[i++] = l;
1800 l = l->l_next;
1801 } while (l);
1802 assert (i == npreloads);
1805 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1806 specified some libraries to load, these are inserted before the actual
1807 dependencies in the executable's searchlist for symbol resolution. */
1808 HP_TIMING_NOW (start);
1809 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1810 HP_TIMING_NOW (stop);
1811 HP_TIMING_DIFF (diff, start, stop);
1812 HP_TIMING_ACCUM_NT (load_time, diff);
1814 /* Mark all objects as being in the global scope. */
1815 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1816 main_map->l_searchlist.r_list[--i]->l_global = 1;
1818 /* Remove _dl_rtld_map from the chain. */
1819 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1820 if (GL(dl_rtld_map).l_next != NULL)
1821 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1823 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1824 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1825 break;
1827 bool rtld_multiple_ref = false;
1828 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1830 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1831 put it back in the list of visible objects. We insert it into the
1832 chain in symbol search order because gdb uses the chain's order as
1833 its symbol search order. */
1834 rtld_multiple_ref = true;
1836 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1837 if (__builtin_expect (mode, normal) == normal)
1839 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1840 ? main_map->l_searchlist.r_list[i + 1]
1841 : NULL);
1842 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1843 if (GLRO(dl_sysinfo_map) != NULL
1844 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1845 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1846 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1847 #endif
1849 else
1850 /* In trace mode there might be an invisible object (which we
1851 could not find) after the previous one in the search list.
1852 In this case it doesn't matter much where we put the
1853 interpreter object, so we just initialize the list pointer so
1854 that the assertion below holds. */
1855 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1857 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1858 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1859 if (GL(dl_rtld_map).l_next != NULL)
1861 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1862 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1866 /* Now let us see whether all libraries are available in the
1867 versions we need. */
1869 struct version_check_args args;
1870 args.doexit = mode == normal;
1871 args.dotrace = mode == trace;
1872 _dl_receive_error (print_missing_version, version_check_doit, &args);
1875 /* We do not initialize any of the TLS functionality unless any of the
1876 initial modules uses TLS. This makes dynamic loading of modules with
1877 TLS impossible, but to support it requires either eagerly doing setup
1878 now or lazily doing it later. Doing it now makes us incompatible with
1879 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1880 used. Trying to do it lazily is too hairy to try when there could be
1881 multiple threads (from a non-TLS-using libpthread). */
1882 bool was_tls_init_tp_called = tls_init_tp_called;
1883 if (tcbp == NULL)
1884 tcbp = init_tls ();
1886 if (__builtin_expect (audit_list == NULL, 1))
1887 /* Initialize security features. But only if we have not done it
1888 earlier. */
1889 security_init ();
1891 if (__builtin_expect (mode, normal) != normal)
1893 /* We were run just to list the shared libraries. It is
1894 important that we do this before real relocation, because the
1895 functions we call below for output may no longer work properly
1896 after relocation. */
1897 struct link_map *l;
1899 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1901 struct r_scope_elem *scope = &main_map->l_searchlist;
1903 for (i = 0; i < scope->r_nlist; i++)
1905 l = scope->r_list [i];
1906 if (l->l_faked)
1908 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1909 continue;
1911 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1912 GLRO(dl_trace_prelink_map) = l;
1913 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1914 l->l_libname->name[0] ? l->l_libname->name
1915 : rtld_progname ?: "<main program>",
1916 l->l_name[0] ? l->l_name
1917 : rtld_progname ?: "<main program>",
1918 (int) sizeof l->l_map_start * 2,
1919 (size_t) l->l_map_start,
1920 (int) sizeof l->l_addr * 2,
1921 (size_t) l->l_addr);
1923 if (l->l_tls_modid)
1924 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1925 (int) sizeof l->l_tls_offset * 2,
1926 (size_t) l->l_tls_offset);
1927 else
1928 _dl_printf ("\n");
1931 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1933 /* Look through the dependencies of the main executable
1934 and determine which of them is not actually
1935 required. */
1936 struct link_map *l = main_map;
1938 /* Relocate the main executable. */
1939 struct relocate_args args = { .l = l,
1940 .reloc_mode = (GLRO(dl_lazy)
1941 ? RTLD_LAZY : 0) };
1942 _dl_receive_error (print_unresolved, relocate_doit, &args);
1944 /* This loop depends on the dependencies of the executable to
1945 correspond in number and order to the DT_NEEDED entries. */
1946 ElfW(Dyn) *dyn = main_map->l_ld;
1947 bool first = true;
1948 while (dyn->d_tag != DT_NULL)
1950 if (dyn->d_tag == DT_NEEDED)
1952 l = l->l_next;
1954 if (!l->l_used)
1956 if (first)
1958 _dl_printf ("Unused direct dependencies:\n");
1959 first = false;
1962 _dl_printf ("\t%s\n", l->l_name);
1966 ++dyn;
1969 _exit (first != true);
1971 else if (! main_map->l_info[DT_NEEDED])
1972 _dl_printf ("\tstatically linked\n");
1973 else
1975 for (l = main_map->l_next; l; l = l->l_next)
1976 if (l->l_faked)
1977 /* The library was not found. */
1978 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1979 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1980 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1981 (int) sizeof l->l_map_start * 2,
1982 (size_t) l->l_map_start);
1983 else
1984 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1985 l->l_name, (int) sizeof l->l_map_start * 2,
1986 (size_t) l->l_map_start);
1989 if (__builtin_expect (mode, trace) != trace)
1990 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1992 const ElfW(Sym) *ref = NULL;
1993 ElfW(Addr) loadbase;
1994 lookup_t result;
1996 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1997 &ref, main_map->l_scope,
1998 NULL, ELF_RTYPE_CLASS_PLT,
1999 DL_LOOKUP_ADD_DEPENDENCY, NULL);
2001 loadbase = LOOKUP_VALUE_ADDRESS (result);
2003 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
2004 INTUSE(_dl_argv)[i],
2005 (int) sizeof ref->st_value * 2,
2006 (size_t) ref->st_value,
2007 (int) sizeof loadbase * 2, (size_t) loadbase);
2009 else
2011 /* If LD_WARN is set, warn about undefined symbols. */
2012 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2014 /* We have to do symbol dependency testing. */
2015 struct relocate_args args;
2016 struct link_map *l;
2018 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2020 l = main_map;
2021 while (l->l_next != NULL)
2022 l = l->l_next;
2025 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2027 args.l = l;
2028 _dl_receive_error (print_unresolved, relocate_doit,
2029 &args);
2031 l = l->l_prev;
2033 while (l != NULL);
2035 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2036 && rtld_multiple_ref)
2038 /* Mark the link map as not yet relocated again. */
2039 GL(dl_rtld_map).l_relocated = 0;
2040 _dl_relocate_object (&GL(dl_rtld_map),
2041 main_map->l_scope, 0, 0);
2044 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2045 if (version_info)
2047 /* Print more information. This means here, print information
2048 about the versions needed. */
2049 int first = 1;
2050 struct link_map *map;
2052 for (map = main_map; map != NULL; map = map->l_next)
2054 const char *strtab;
2055 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2056 ElfW(Verneed) *ent;
2058 if (dyn == NULL)
2059 continue;
2061 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2062 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2064 if (first)
2066 _dl_printf ("\n\tVersion information:\n");
2067 first = 0;
2070 _dl_printf ("\t%s:\n",
2071 map->l_name[0] ? map->l_name : rtld_progname);
2073 while (1)
2075 ElfW(Vernaux) *aux;
2076 struct link_map *needed;
2078 needed = find_needed (strtab + ent->vn_file);
2079 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2081 while (1)
2083 const char *fname = NULL;
2085 if (needed != NULL
2086 && match_version (strtab + aux->vna_name,
2087 needed))
2088 fname = needed->l_name;
2090 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2091 strtab + ent->vn_file,
2092 strtab + aux->vna_name,
2093 aux->vna_flags & VER_FLG_WEAK
2094 ? "[WEAK] " : "",
2095 fname ?: "not found");
2097 if (aux->vna_next == 0)
2098 /* No more symbols. */
2099 break;
2101 /* Next symbol. */
2102 aux = (ElfW(Vernaux) *) ((char *) aux
2103 + aux->vna_next);
2106 if (ent->vn_next == 0)
2107 /* No more dependencies. */
2108 break;
2110 /* Next dependency. */
2111 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2117 _exit (0);
2120 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2121 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2122 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2124 ElfW(Lib) *liblist, *liblistend;
2125 struct link_map **r_list, **r_listend, *l;
2126 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2128 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2129 liblist = (ElfW(Lib) *)
2130 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2131 liblistend = (ElfW(Lib) *)
2132 ((char *) liblist +
2133 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2134 r_list = main_map->l_searchlist.r_list;
2135 r_listend = r_list + main_map->l_searchlist.r_nlist;
2137 for (; r_list < r_listend && liblist < liblistend; r_list++)
2139 l = *r_list;
2141 if (l == main_map)
2142 continue;
2144 /* If the library is not mapped where it should, fail. */
2145 if (l->l_addr)
2146 break;
2148 /* Next, check if checksum matches. */
2149 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2150 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2151 != liblist->l_checksum)
2152 break;
2154 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2155 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2156 != liblist->l_time_stamp)
2157 break;
2159 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2160 break;
2162 ++liblist;
2166 if (r_list == r_listend && liblist == liblistend)
2167 prelinked = true;
2169 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2170 _dl_debug_printf ("\nprelink checking: %s\n",
2171 prelinked ? "ok" : "failed");
2175 /* Now set up the variable which helps the assembler startup code. */
2176 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2178 /* Save the information about the original global scope list since
2179 we need it in the memory handling later. */
2180 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2182 /* Remember the last search directory added at startup, now that
2183 malloc will no longer be the one from dl-minimal.c. */
2184 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2186 if (prelinked)
2188 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2190 ElfW(Rela) *conflict, *conflictend;
2191 #ifndef HP_TIMING_NONAVAIL
2192 hp_timing_t start;
2193 hp_timing_t stop;
2194 #endif
2196 HP_TIMING_NOW (start);
2197 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2198 conflict = (ElfW(Rela) *)
2199 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2200 conflictend = (ElfW(Rela) *)
2201 ((char *) conflict
2202 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2203 _dl_resolve_conflicts (main_map, conflict, conflictend);
2204 HP_TIMING_NOW (stop);
2205 HP_TIMING_DIFF (relocate_time, start, stop);
2209 /* Mark all the objects so we know they have been already relocated. */
2210 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2212 l->l_relocated = 1;
2213 if (l->l_relro_size)
2214 _dl_protect_relro (l);
2216 /* Add object to slot information data if necessasy. */
2217 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2218 _dl_add_to_slotinfo (l);
2221 else
2223 /* Now we have all the objects loaded. Relocate them all except for
2224 the dynamic linker itself. We do this in reverse order so that copy
2225 relocs of earlier objects overwrite the data written by later
2226 objects. We do not re-relocate the dynamic linker itself in this
2227 loop because that could result in the GOT entries for functions we
2228 call being changed, and that would break us. It is safe to relocate
2229 the dynamic linker out of order because it has no copy relocs (we
2230 know that because it is self-contained). */
2232 int consider_profiling = GLRO(dl_profile) != NULL;
2233 #ifndef HP_TIMING_NONAVAIL
2234 hp_timing_t start;
2235 hp_timing_t stop;
2236 #endif
2238 /* If we are profiling we also must do lazy reloaction. */
2239 GLRO(dl_lazy) |= consider_profiling;
2241 struct link_map *l = main_map;
2242 while (l->l_next)
2243 l = l->l_next;
2245 HP_TIMING_NOW (start);
2248 /* While we are at it, help the memory handling a bit. We have to
2249 mark some data structures as allocated with the fake malloc()
2250 implementation in ld.so. */
2251 struct libname_list *lnp = l->l_libname->next;
2253 while (__builtin_expect (lnp != NULL, 0))
2255 lnp->dont_free = 1;
2256 lnp = lnp->next;
2259 if (l != &GL(dl_rtld_map))
2260 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2261 consider_profiling);
2263 /* Add object to slot information data if necessasy. */
2264 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2265 _dl_add_to_slotinfo (l);
2267 l = l->l_prev;
2269 while (l);
2270 HP_TIMING_NOW (stop);
2272 HP_TIMING_DIFF (relocate_time, start, stop);
2274 /* Now enable profiling if needed. Like the previous call,
2275 this has to go here because the calls it makes should use the
2276 rtld versions of the functions (particularly calloc()), but it
2277 needs to have _dl_profile_map set up by the relocator. */
2278 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2279 /* We must prepare the profiling. */
2280 _dl_start_profile ();
2283 #ifndef NONTLS_INIT_TP
2284 # define NONTLS_INIT_TP do { } while (0)
2285 #endif
2287 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2288 ++GL(dl_tls_generation);
2290 /* Now that we have completed relocation, the initializer data
2291 for the TLS blocks has its final values and we can copy them
2292 into the main thread's TLS area, which we allocated above. */
2293 _dl_allocate_tls_init (tcbp);
2295 /* And finally install it for the main thread. If ld.so itself uses
2296 TLS we know the thread pointer was initialized earlier. */
2297 if (! tls_init_tp_called)
2299 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2300 if (__builtin_expect (lossage != NULL, 0))
2301 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2302 lossage);
2305 /* Make sure no new search directories have been added. */
2306 assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
2308 if (! prelinked && rtld_multiple_ref)
2310 /* There was an explicit ref to the dynamic linker as a shared lib.
2311 Re-relocate ourselves with user-controlled symbol definitions.
2313 We must do this after TLS initialization in case after this
2314 re-relocation, we might call a user-supplied function
2315 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2317 #ifndef HP_TIMING_NONAVAIL
2318 hp_timing_t start;
2319 hp_timing_t stop;
2320 hp_timing_t add;
2321 #endif
2323 HP_TIMING_NOW (start);
2324 /* Mark the link map as not yet relocated again. */
2325 GL(dl_rtld_map).l_relocated = 0;
2326 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2327 HP_TIMING_NOW (stop);
2328 HP_TIMING_DIFF (add, start, stop);
2329 HP_TIMING_ACCUM_NT (relocate_time, add);
2332 /* Do any necessary cleanups for the startup OS interface code.
2333 We do these now so that no calls are made after rtld re-relocation
2334 which might be resolved to different functions than we expect.
2335 We cannot do this before relocating the other objects because
2336 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2337 _dl_sysdep_start_cleanup ();
2339 #ifdef SHARED
2340 /* Auditing checkpoint: we have added all objects. */
2341 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2343 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2344 /* Do not call the functions for any auditing object. */
2345 if (head->l_auditing == 0)
2347 struct audit_ifaces *afct = GLRO(dl_audit);
2348 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2350 if (afct->activity != NULL)
2351 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2353 afct = afct->next;
2357 #endif
2359 /* Notify the debugger all new objects are now ready to go. We must re-get
2360 the address since by now the variable might be in another object. */
2361 r = _dl_debug_initialize (0, LM_ID_BASE);
2362 r->r_state = RT_CONSISTENT;
2363 _dl_debug_state ();
2365 #ifndef MAP_COPY
2366 /* We must munmap() the cache file. */
2367 _dl_unload_cache ();
2368 #endif
2370 /* Once we return, _dl_sysdep_start will invoke
2371 the DT_INIT functions and then *USER_ENTRY. */
2374 /* This is a little helper function for resolving symbols while
2375 tracing the binary. */
2376 static void
2377 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2378 const char *errstring)
2380 if (objname[0] == '\0')
2381 objname = rtld_progname ?: "<main program>";
2382 _dl_error_printf ("%s (%s)\n", errstring, objname);
2385 /* This is a little helper function for resolving symbols while
2386 tracing the binary. */
2387 static void
2388 print_missing_version (int errcode __attribute__ ((unused)),
2389 const char *objname, const char *errstring)
2391 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2392 objname, errstring);
2395 /* Nonzero if any of the debugging options is enabled. */
2396 static int any_debug attribute_relro;
2398 /* Process the string given as the parameter which explains which debugging
2399 options are enabled. */
2400 static void
2401 process_dl_debug (const char *dl_debug)
2403 /* When adding new entries make sure that the maximal length of a name
2404 is correctly handled in the LD_DEBUG_HELP code below. */
2405 static const struct
2407 unsigned char len;
2408 const char name[10];
2409 const char helptext[41];
2410 unsigned short int mask;
2411 } debopts[] =
2413 #define LEN_AND_STR(str) sizeof (str) - 1, str
2414 { LEN_AND_STR ("libs"), "display library search paths",
2415 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2416 { LEN_AND_STR ("reloc"), "display relocation processing",
2417 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2418 { LEN_AND_STR ("files"), "display progress for input file",
2419 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2420 { LEN_AND_STR ("symbols"), "display symbol table processing",
2421 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2422 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2423 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2424 { LEN_AND_STR ("versions"), "display version dependencies",
2425 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2426 { LEN_AND_STR ("all"), "all previous options combined",
2427 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2428 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2429 { LEN_AND_STR ("statistics"), "display relocation statistics",
2430 DL_DEBUG_STATISTICS },
2431 { LEN_AND_STR ("unused"), "determined unused DSOs",
2432 DL_DEBUG_UNUSED },
2433 { LEN_AND_STR ("help"), "display this help message and exit",
2434 DL_DEBUG_HELP },
2436 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2438 /* Skip separating white spaces and commas. */
2439 while (*dl_debug != '\0')
2441 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2443 size_t cnt;
2444 size_t len = 1;
2446 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2447 && dl_debug[len] != ',' && dl_debug[len] != ':')
2448 ++len;
2450 for (cnt = 0; cnt < ndebopts; ++cnt)
2451 if (debopts[cnt].len == len
2452 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2454 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2455 any_debug = 1;
2456 break;
2459 if (cnt == ndebopts)
2461 /* Display a warning and skip everything until next
2462 separator. */
2463 char *copy = strndupa (dl_debug, len);
2464 _dl_error_printf ("\
2465 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2468 dl_debug += len;
2469 continue;
2472 ++dl_debug;
2475 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2477 size_t cnt;
2479 _dl_printf ("\
2480 Valid options for the LD_DEBUG environment variable are:\n\n");
2482 for (cnt = 0; cnt < ndebopts; ++cnt)
2483 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2484 " " + debopts[cnt].len - 3,
2485 debopts[cnt].helptext);
2487 _dl_printf ("\n\
2488 To direct the debugging output into a file instead of standard output\n\
2489 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2490 _exit (0);
2494 static void
2495 process_dl_audit (char *str)
2497 /* The parameter is a colon separated list of DSO names. */
2498 char *p;
2500 while ((p = (strsep) (&str, ":")) != NULL)
2501 if (p[0] != '\0'
2502 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2503 || strchr (p, '/') == NULL))
2505 /* This is using the local malloc, not the system malloc. The
2506 memory can never be freed. */
2507 struct audit_list *newp = malloc (sizeof (*newp));
2508 newp->name = p;
2510 if (audit_list == NULL)
2511 audit_list = newp->next = newp;
2512 else
2514 newp->next = audit_list->next;
2515 audit_list = audit_list->next = newp;
2520 /* Process all environments variables the dynamic linker must recognize.
2521 Since all of them start with `LD_' we are a bit smarter while finding
2522 all the entries. */
2523 extern char **_environ attribute_hidden;
2526 static void
2527 process_envvars (enum mode *modep)
2529 char **runp = _environ;
2530 char *envline;
2531 enum mode mode = normal;
2532 char *debug_output = NULL;
2534 /* This is the default place for profiling data file. */
2535 GLRO(dl_profile_output)
2536 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2538 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2540 size_t len = 0;
2542 while (envline[len] != '\0' && envline[len] != '=')
2543 ++len;
2545 if (envline[len] != '=')
2546 /* This is a "LD_" variable at the end of the string without
2547 a '=' character. Ignore it since otherwise we will access
2548 invalid memory below. */
2549 continue;
2551 switch (len)
2553 case 4:
2554 /* Warning level, verbose or not. */
2555 if (memcmp (envline, "WARN", 4) == 0)
2556 GLRO(dl_verbose) = envline[5] != '\0';
2557 break;
2559 case 5:
2560 /* Debugging of the dynamic linker? */
2561 if (memcmp (envline, "DEBUG", 5) == 0)
2563 process_dl_debug (&envline[6]);
2564 break;
2566 if (memcmp (envline, "AUDIT", 5) == 0)
2567 process_dl_audit (&envline[6]);
2568 break;
2570 case 7:
2571 /* Print information about versions. */
2572 if (memcmp (envline, "VERBOSE", 7) == 0)
2574 version_info = envline[8] != '\0';
2575 break;
2578 /* List of objects to be preloaded. */
2579 if (memcmp (envline, "PRELOAD", 7) == 0)
2581 preloadlist = &envline[8];
2582 break;
2585 /* Which shared object shall be profiled. */
2586 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2587 GLRO(dl_profile) = &envline[8];
2588 break;
2590 case 8:
2591 /* Do we bind early? */
2592 if (memcmp (envline, "BIND_NOW", 8) == 0)
2594 GLRO(dl_lazy) = envline[9] == '\0';
2595 break;
2597 if (memcmp (envline, "BIND_NOT", 8) == 0)
2598 GLRO(dl_bind_not) = envline[9] != '\0';
2599 break;
2601 case 9:
2602 /* Test whether we want to see the content of the auxiliary
2603 array passed up from the kernel. */
2604 if (!INTUSE(__libc_enable_secure)
2605 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2606 _dl_show_auxv ();
2607 break;
2609 case 10:
2610 /* Mask for the important hardware capabilities. */
2611 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2612 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2613 0, 0);
2614 break;
2616 case 11:
2617 /* Path where the binary is found. */
2618 if (!INTUSE(__libc_enable_secure)
2619 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2620 GLRO(dl_origin_path) = &envline[12];
2621 break;
2623 case 12:
2624 /* The library search path. */
2625 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2627 library_path = &envline[13];
2628 break;
2631 /* Where to place the profiling data file. */
2632 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2634 debug_output = &envline[13];
2635 break;
2638 if (!INTUSE(__libc_enable_secure)
2639 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2640 GLRO(dl_dynamic_weak) = 1;
2641 break;
2643 case 13:
2644 /* We might have some extra environment variable with length 13
2645 to handle. */
2646 #ifdef EXTRA_LD_ENVVARS_13
2647 EXTRA_LD_ENVVARS_13
2648 #endif
2649 if (!INTUSE(__libc_enable_secure)
2650 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2652 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2653 break;
2656 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2657 GLRO(dl_pointer_guard) = envline[14] != '0';
2658 break;
2660 case 14:
2661 /* Where to place the profiling data file. */
2662 if (!INTUSE(__libc_enable_secure)
2663 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2664 && envline[15] != '\0')
2665 GLRO(dl_profile_output) = &envline[15];
2666 break;
2668 case 16:
2669 /* The mode of the dynamic linker can be set. */
2670 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2672 mode = trace;
2673 GLRO(dl_verbose) = 1;
2674 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2675 GLRO(dl_trace_prelink) = &envline[17];
2677 break;
2679 case 20:
2680 /* The mode of the dynamic linker can be set. */
2681 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2682 mode = trace;
2683 break;
2685 /* We might have some extra environment variable to handle. This
2686 is tricky due to the pre-processing of the length of the name
2687 in the switch statement here. The code here assumes that added
2688 environment variables have a different length. */
2689 #ifdef EXTRA_LD_ENVVARS
2690 EXTRA_LD_ENVVARS
2691 #endif
2695 /* The caller wants this information. */
2696 *modep = mode;
2698 /* Extra security for SUID binaries. Remove all dangerous environment
2699 variables. */
2700 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2702 static const char unsecure_envvars[] =
2703 #ifdef EXTRA_UNSECURE_ENVVARS
2704 EXTRA_UNSECURE_ENVVARS
2705 #endif
2706 UNSECURE_ENVVARS;
2707 const char *nextp;
2709 nextp = unsecure_envvars;
2712 unsetenv (nextp);
2713 /* We could use rawmemchr but this need not be fast. */
2714 nextp = (char *) (strchr) (nextp, '\0') + 1;
2716 while (*nextp != '\0');
2718 if (__access ("/etc/suid-debug", F_OK) != 0)
2720 unsetenv ("MALLOC_CHECK_");
2721 GLRO(dl_debug_mask) = 0;
2724 if (mode != normal)
2725 _exit (5);
2727 /* If we have to run the dynamic linker in debugging mode and the
2728 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2729 messages to this file. */
2730 else if (any_debug && debug_output != NULL)
2732 #ifdef O_NOFOLLOW
2733 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2734 #else
2735 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2736 #endif
2737 size_t name_len = strlen (debug_output);
2738 char buf[name_len + 12];
2739 char *startp;
2741 buf[name_len + 11] = '\0';
2742 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2743 *--startp = '.';
2744 startp = memcpy (startp - name_len, debug_output, name_len);
2746 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2747 if (GLRO(dl_debug_fd) == -1)
2748 /* We use standard output if opening the file failed. */
2749 GLRO(dl_debug_fd) = STDOUT_FILENO;
2754 /* Print the various times we collected. */
2755 static void
2756 __attribute ((noinline))
2757 print_statistics (hp_timing_t *rtld_total_timep)
2759 #ifndef HP_TIMING_NONAVAIL
2760 char buf[200];
2761 char *cp;
2762 char *wp;
2764 /* Total time rtld used. */
2765 if (HP_TIMING_AVAIL)
2767 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2768 _dl_debug_printf ("\nruntime linker statistics:\n"
2769 " total startup time in dynamic loader: %s\n", buf);
2771 /* Print relocation statistics. */
2772 char pbuf[30];
2773 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2774 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2775 pbuf + sizeof (pbuf), 10, 0);
2776 wp = pbuf;
2777 switch (pbuf + sizeof (pbuf) - cp)
2779 case 3:
2780 *wp++ = *cp++;
2781 case 2:
2782 *wp++ = *cp++;
2783 case 1:
2784 *wp++ = '.';
2785 *wp++ = *cp++;
2787 *wp = '\0';
2788 _dl_debug_printf ("\
2789 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2791 #endif
2793 unsigned long int num_relative_relocations = 0;
2794 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2796 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2797 continue;
2799 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2801 for (unsigned int i = 0; i < scope->r_nlist; i++)
2803 struct link_map *l = scope->r_list [i];
2805 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2806 num_relative_relocations
2807 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2808 #ifndef ELF_MACHINE_REL_RELATIVE
2809 /* Relative relocations are processed on these architectures if
2810 library is loaded to different address than p_vaddr or
2811 if not prelinked. */
2812 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2813 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2814 #else
2815 /* On e.g. IA-64 or Alpha, relative relocations are processed
2816 only if library is loaded to different address than p_vaddr. */
2817 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2818 #endif
2819 num_relative_relocations
2820 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2824 _dl_debug_printf (" number of relocations: %lu\n"
2825 " number of relocations from cache: %lu\n"
2826 " number of relative relocations: %lu\n",
2827 GL(dl_num_relocations),
2828 GL(dl_num_cache_relocations),
2829 num_relative_relocations);
2831 #ifndef HP_TIMING_NONAVAIL
2832 /* Time spend while loading the object and the dependencies. */
2833 if (HP_TIMING_AVAIL)
2835 char pbuf[30];
2836 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2837 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2838 pbuf + sizeof (pbuf), 10, 0);
2839 wp = pbuf;
2840 switch (pbuf + sizeof (pbuf) - cp)
2842 case 3:
2843 *wp++ = *cp++;
2844 case 2:
2845 *wp++ = *cp++;
2846 case 1:
2847 *wp++ = '.';
2848 *wp++ = *cp++;
2850 *wp = '\0';
2851 _dl_debug_printf ("\
2852 time needed to load objects: %s (%s%%)\n",
2853 buf, pbuf);
2855 #endif