* include/string.h: Only redefine strndupa if this is really for
[glibc.git] / elf / rtld.c
blob5e6ee516039d2f05fdc37b9f8f13b44acffcd768
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2002,2003,2004,2005,2006 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h> /* Check if MAP_ANON is defined. */
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
44 #include <assert.h>
46 /* Avoid PLT use for our local calls at startup. */
47 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
49 /* GCC has mental blocks about _exit. */
50 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
51 #define _exit exit_internal
53 /* Helper function to handle errors while resolving symbols. */
54 static void print_unresolved (int errcode, const char *objname,
55 const char *errsting);
57 /* Helper function to handle errors when a version is missing. */
58 static void print_missing_version (int errcode, const char *objname,
59 const char *errsting);
61 /* Print the various times we collected. */
62 static void print_statistics (hp_timing_t *total_timep);
64 /* Add audit objects. */
65 static void process_dl_audit (char *str);
67 /* This is a list of all the modes the dynamic loader can be in. */
68 enum mode { normal, list, verify, trace };
70 /* Process all environments variables the dynamic linker must recognize.
71 Since all of them start with `LD_' we are a bit smarter while finding
72 all the entries. */
73 static void process_envvars (enum mode *modep);
75 #ifdef DL_ARGV_NOT_RELRO
76 int _dl_argc attribute_hidden;
77 char **_dl_argv = NULL;
78 /* Nonzero if we were run directly. */
79 unsigned int _dl_skip_args attribute_hidden;
80 #else
81 int _dl_argc attribute_relro attribute_hidden;
82 char **_dl_argv attribute_relro = NULL;
83 unsigned int _dl_skip_args attribute_relro attribute_hidden;
84 #endif
85 INTDEF(_dl_argv)
87 #ifndef THREAD_SET_STACK_GUARD
88 /* Only exported for architectures that don't store the stack guard canary
89 in thread local area. */
90 uintptr_t __stack_chk_guard attribute_relro;
91 #endif
93 /* Only exported for architectures that don't store the pointer guard
94 value in thread local area. */
95 uintptr_t __pointer_chk_guard_local
96 attribute_relro attribute_hidden __attribute__ ((nocommon));
97 #ifndef THREAD_SET_POINTER_GUARD
98 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
99 #endif
102 /* List of auditing DSOs. */
103 static struct audit_list
105 const char *name;
106 struct audit_list *next;
107 } *audit_list;
109 #ifndef HAVE_INLINED_SYSCALLS
110 /* Set nonzero during loading and initialization of executable and
111 libraries, cleared before the executable's entry point runs. This
112 must not be initialized to nonzero, because the unused dynamic
113 linker loaded in for libc.so's "ld.so.1" dep will provide the
114 definition seen by libc.so's initializer; that value must be zero,
115 and will be since that dynamic linker's _dl_start and dl_main will
116 never be called. */
117 int _dl_starting_up = 0;
118 INTVARDEF(_dl_starting_up)
119 #endif
121 /* This is the structure which defines all variables global to ld.so
122 (except those which cannot be added for some reason). */
123 struct rtld_global _rtld_global =
125 /* Default presumption without further information is executable stack. */
126 ._dl_stack_flags = PF_R|PF_W|PF_X,
127 #ifdef _LIBC_REENTRANT
128 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER
129 #endif
131 /* If we would use strong_alias here the compiler would see a
132 non-hidden definition. This would undo the effect of the previous
133 declaration. So spell out was strong_alias does plus add the
134 visibility attribute. */
135 extern struct rtld_global _rtld_local
136 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
139 /* This variable is similar to _rtld_local, but all values are
140 read-only after relocation. */
141 struct rtld_global_ro _rtld_global_ro attribute_relro =
143 /* Get architecture specific initializer. */
144 #include <dl-procinfo.c>
145 #ifdef NEED_DL_SYSINFO
146 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
147 #endif
148 ._dl_debug_fd = STDERR_FILENO,
149 ._dl_use_load_bias = -2,
150 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
151 ._dl_hwcap_mask = HWCAP_IMPORTANT,
152 ._dl_lazy = 1,
153 ._dl_fpu_control = _FPU_DEFAULT,
154 ._dl_pointer_guard = 1,
156 /* Function pointers. */
157 ._dl_debug_printf = _dl_debug_printf,
158 ._dl_catch_error = _dl_catch_error,
159 ._dl_signal_error = _dl_signal_error,
160 ._dl_mcount = _dl_mcount_internal,
161 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
162 ._dl_check_caller = _dl_check_caller,
163 ._dl_open = _dl_open,
164 ._dl_close = _dl_close
166 /* If we would use strong_alias here the compiler would see a
167 non-hidden definition. This would undo the effect of the previous
168 declaration. So spell out was strong_alias does plus add the
169 visibility attribute. */
170 extern struct rtld_global_ro _rtld_local_ro
171 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
174 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
175 ElfW(Addr) *user_entry);
177 /* These two variables cannot be moved into .data.rel.ro. */
178 static struct libname_list _dl_rtld_libname;
179 static struct libname_list _dl_rtld_libname2;
181 /* We expect less than a second for relocation. */
182 #ifdef HP_SMALL_TIMING_AVAIL
183 # undef HP_TIMING_AVAIL
184 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
185 #endif
187 /* Variable for statistics. */
188 #ifndef HP_TIMING_NONAVAIL
189 static hp_timing_t relocate_time;
190 static hp_timing_t load_time attribute_relro;
191 static hp_timing_t start_time attribute_relro;
192 #endif
194 /* Additional definitions needed by TLS initialization. */
195 #ifdef TLS_INIT_HELPER
196 TLS_INIT_HELPER
197 #endif
199 /* Helper function for syscall implementation. */
200 #ifdef DL_SYSINFO_IMPLEMENTATION
201 DL_SYSINFO_IMPLEMENTATION
202 #endif
204 /* Before ld.so is relocated we must not access variables which need
205 relocations. This means variables which are exported. Variables
206 declared as static are fine. If we can mark a variable hidden this
207 is fine, too. The latter is important here. We can avoid setting
208 up a temporary link map for ld.so if we can mark _rtld_global as
209 hidden. */
210 #ifdef PI_STATIC_AND_HIDDEN
211 # define DONT_USE_BOOTSTRAP_MAP 1
212 #endif
214 #ifdef DONT_USE_BOOTSTRAP_MAP
215 static ElfW(Addr) _dl_start_final (void *arg);
216 #else
217 struct dl_start_final_info
219 struct link_map l;
220 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
221 hp_timing_t start_time;
222 #endif
224 static ElfW(Addr) _dl_start_final (void *arg,
225 struct dl_start_final_info *info);
226 #endif
228 /* These defined magically in the linker script. */
229 extern char _begin[] attribute_hidden;
230 extern char _etext[] attribute_hidden;
231 extern char _end[] attribute_hidden;
234 #ifdef RTLD_START
235 RTLD_START
236 #else
237 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
238 #endif
240 #ifndef VALIDX
241 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
242 + DT_EXTRANUM + DT_VALTAGIDX (tag))
243 #endif
244 #ifndef ADDRIDX
245 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
246 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
247 #endif
249 /* This is the second half of _dl_start (below). It can be inlined safely
250 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
251 references. When the tools don't permit us to avoid using a GOT entry
252 for _dl_rtld_global (no attribute_hidden support), we must make sure
253 this function is not inlined (see below). */
255 #ifdef DONT_USE_BOOTSTRAP_MAP
256 static inline ElfW(Addr) __attribute__ ((always_inline))
257 _dl_start_final (void *arg)
258 #else
259 static ElfW(Addr) __attribute__ ((noinline))
260 _dl_start_final (void *arg, struct dl_start_final_info *info)
261 #endif
263 ElfW(Addr) start_addr;
265 if (HP_TIMING_AVAIL)
267 /* If it hasn't happen yet record the startup time. */
268 if (! HP_TIMING_INLINE)
269 HP_TIMING_NOW (start_time);
270 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
271 else
272 start_time = info->start_time;
273 #endif
275 /* Initialize the timing functions. */
276 HP_TIMING_DIFF_INIT ();
279 /* Transfer data about ourselves to the permanent link_map structure. */
280 #ifndef DONT_USE_BOOTSTRAP_MAP
281 GL(dl_rtld_map).l_addr = info->l.l_addr;
282 GL(dl_rtld_map).l_ld = info->l.l_ld;
283 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
284 sizeof GL(dl_rtld_map).l_info);
285 GL(dl_rtld_map).l_mach = info->l.l_mach;
286 GL(dl_rtld_map).l_relocated = 1;
287 #endif
288 _dl_setup_hash (&GL(dl_rtld_map));
289 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
290 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
291 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
292 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
293 /* Copy the TLS related data if necessary. */
294 #ifndef DONT_USE_BOOTSTRAP_MAP
295 # if USE___THREAD
296 assert (info->l.l_tls_modid != 0);
297 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
298 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
299 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
300 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
301 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
302 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
303 GL(dl_rtld_map).l_tls_modid = 1;
304 # else
305 # if NO_TLS_OFFSET != 0
306 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
307 # endif
308 # endif
310 #endif
312 #if HP_TIMING_AVAIL
313 HP_TIMING_NOW (GL(dl_cpuclock_offset));
314 #endif
316 /* Initialize the stack end variable. */
317 __libc_stack_end = __builtin_frame_address (0);
319 /* Call the OS-dependent function to set up life so we can do things like
320 file access. It will call `dl_main' (below) to do all the real work
321 of the dynamic linker, and then unwind our frame and run the user
322 entry point on the same stack we entered on. */
323 start_addr = _dl_sysdep_start (arg, &dl_main);
325 #ifndef HP_TIMING_NONAVAIL
326 hp_timing_t rtld_total_time;
327 if (HP_TIMING_AVAIL)
329 hp_timing_t end_time;
331 /* Get the current time. */
332 HP_TIMING_NOW (end_time);
334 /* Compute the difference. */
335 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
337 #endif
339 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
341 #ifndef HP_TIMING_NONAVAIL
342 print_statistics (&rtld_total_time);
343 #else
344 print_statistics (NULL);
345 #endif
348 return start_addr;
351 static ElfW(Addr) __attribute_used__ internal_function
352 _dl_start (void *arg)
354 #ifdef DONT_USE_BOOTSTRAP_MAP
355 # define bootstrap_map GL(dl_rtld_map)
356 #else
357 struct dl_start_final_info info;
358 # define bootstrap_map info.l
359 #endif
361 /* This #define produces dynamic linking inline functions for
362 bootstrap relocation instead of general-purpose relocation. */
363 #define RTLD_BOOTSTRAP
364 #define RESOLVE_MAP(sym, version, flags) \
365 ((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map)
366 #include "dynamic-link.h"
368 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
369 #ifdef DONT_USE_BOOTSTRAP_MAP
370 HP_TIMING_NOW (start_time);
371 #else
372 HP_TIMING_NOW (info.start_time);
373 #endif
375 /* Partly clean the `bootstrap_map' structure up. Don't use
376 `memset' since it might not be built in or inlined and we cannot
377 make function calls at this point. Use '__builtin_memset' if we
378 know it is available. We do not have to clear the memory if we
379 do not have to use the temporary bootstrap_map. Global variables
380 are initialized to zero by default. */
381 #ifndef DONT_USE_BOOTSTRAP_MAP
382 # ifdef HAVE_BUILTIN_MEMSET
383 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
384 # else
385 for (size_t cnt = 0;
386 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
387 ++cnt)
388 bootstrap_map.l_info[cnt] = 0;
389 # endif
390 # if USE___THREAD
391 bootstrap_map.l_tls_modid = 0;
392 # endif
393 #endif
395 /* Figure out the run-time load address of the dynamic linker itself. */
396 bootstrap_map.l_addr = elf_machine_load_address ();
398 /* Read our own dynamic section and fill in the info array. */
399 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
400 elf_get_dynamic_info (&bootstrap_map, NULL);
402 #if NO_TLS_OFFSET != 0
403 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
404 #endif
406 /* Get the dynamic linker's own program header. First we need the ELF
407 file header. The `_begin' symbol created by the linker script points
408 to it. When we have something like GOTOFF relocs, we can use a plain
409 reference to find the runtime address. Without that, we have to rely
410 on the `l_addr' value, which is not the value we want when prelinked. */
411 #if USE___THREAD
412 dtv_t initdtv[3];
413 ElfW(Ehdr) *ehdr
414 # ifdef DONT_USE_BOOTSTRAP_MAP
415 = (ElfW(Ehdr) *) &_begin;
416 # else
417 # error This will not work with prelink.
418 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
419 # endif
420 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
421 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
422 while (cnt-- > 0)
423 if (phdr[cnt].p_type == PT_TLS)
425 void *tlsblock;
426 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
427 char *p;
429 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
430 bootstrap_map.l_tls_align = phdr[cnt].p_align;
431 if (phdr[cnt].p_align == 0)
432 bootstrap_map.l_tls_firstbyte_offset = 0;
433 else
434 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
435 & (phdr[cnt].p_align - 1));
436 assert (bootstrap_map.l_tls_blocksize != 0);
437 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
438 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
439 + phdr[cnt].p_vaddr);
441 /* We can now allocate the initial TLS block. This can happen
442 on the stack. We'll get the final memory later when we
443 know all about the various objects loaded at startup
444 time. */
445 # if TLS_TCB_AT_TP
446 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
447 TLS_INIT_TCB_ALIGN)
448 + TLS_INIT_TCB_SIZE
449 + max_align);
450 # elif TLS_DTV_AT_TP
451 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
452 bootstrap_map.l_tls_align)
453 + bootstrap_map.l_tls_blocksize
454 + max_align);
455 # else
456 /* In case a model with a different layout for the TCB and DTV
457 is defined add another #elif here and in the following #ifs. */
458 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
459 # endif
460 /* Align the TLS block. */
461 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
462 & ~(max_align - 1));
464 /* Initialize the dtv. [0] is the length, [1] the generation
465 counter. */
466 initdtv[0].counter = 1;
467 initdtv[1].counter = 0;
469 /* Initialize the TLS block. */
470 # if TLS_TCB_AT_TP
471 initdtv[2].pointer = tlsblock;
472 # elif TLS_DTV_AT_TP
473 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
474 bootstrap_map.l_tls_align);
475 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
476 # else
477 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
478 # endif
479 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
480 bootstrap_map.l_tls_initimage_size);
481 # ifdef HAVE_BUILTIN_MEMSET
482 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
483 - bootstrap_map.l_tls_initimage_size));
484 # else
486 size_t remaining = (bootstrap_map.l_tls_blocksize
487 - bootstrap_map.l_tls_initimage_size);
488 while (remaining-- > 0)
489 *p++ = '\0';
491 # endif
493 /* Install the pointer to the dtv. */
495 /* Initialize the thread pointer. */
496 # if TLS_TCB_AT_TP
497 bootstrap_map.l_tls_offset
498 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
500 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
501 initdtv);
503 const char *lossage = TLS_INIT_TP ((char *) tlsblock
504 + bootstrap_map.l_tls_offset, 0);
505 # elif TLS_DTV_AT_TP
506 INSTALL_DTV (tlsblock, initdtv);
507 const char *lossage = TLS_INIT_TP (tlsblock, 0);
508 # else
509 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
510 # endif
511 if (__builtin_expect (lossage != NULL, 0))
512 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
513 lossage);
515 /* So far this is module number one. */
516 bootstrap_map.l_tls_modid = 1;
518 /* There can only be one PT_TLS entry. */
519 break;
521 #endif /* USE___THREAD */
523 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
524 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
525 #endif
527 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
529 /* Relocate ourselves so we can do normal function calls and
530 data access using the global offset table. */
532 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
534 bootstrap_map.l_relocated = 1;
536 /* Please note that we don't allow profiling of this object and
537 therefore need not test whether we have to allocate the array
538 for the relocation results (as done in dl-reloc.c). */
540 /* Now life is sane; we can call functions and access global data.
541 Set up to use the operating system facilities, and find out from
542 the operating system's program loader where to find the program
543 header table in core. Put the rest of _dl_start into a separate
544 function, that way the compiler cannot put accesses to the GOT
545 before ELF_DYNAMIC_RELOCATE. */
547 #ifdef DONT_USE_BOOTSTRAP_MAP
548 ElfW(Addr) entry = _dl_start_final (arg);
549 #else
550 ElfW(Addr) entry = _dl_start_final (arg, &info);
551 #endif
553 #ifndef ELF_MACHINE_START_ADDRESS
554 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
555 #endif
557 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
563 /* Now life is peachy; we can do all normal operations.
564 On to the real work. */
566 /* Some helper functions. */
568 /* Arguments to relocate_doit. */
569 struct relocate_args
571 struct link_map *l;
572 int lazy;
575 struct map_args
577 /* Argument to map_doit. */
578 char *str;
579 struct link_map *loader;
580 int is_preloaded;
581 int mode;
582 /* Return value of map_doit. */
583 struct link_map *map;
586 struct dlmopen_args
588 const char *fname;
589 struct link_map *map;
592 struct lookup_args
594 const char *name;
595 struct link_map *map;
596 void *result;
599 /* Arguments to version_check_doit. */
600 struct version_check_args
602 int doexit;
603 int dotrace;
606 static void
607 relocate_doit (void *a)
609 struct relocate_args *args = (struct relocate_args *) a;
611 _dl_relocate_object (args->l, args->l->l_scope, args->lazy, 0);
614 static void
615 map_doit (void *a)
617 struct map_args *args = (struct map_args *) a;
618 args->map = _dl_map_object (args->loader, args->str,
619 args->is_preloaded, lt_library, 0, args->mode,
620 LM_ID_BASE);
623 static void
624 dlmopen_doit (void *a)
626 struct dlmopen_args *args = (struct dlmopen_args *) a;
627 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
628 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
629 __environ);
632 static void
633 lookup_doit (void *a)
635 struct lookup_args *args = (struct lookup_args *) a;
636 const ElfW(Sym) *ref = NULL;
637 args->result = NULL;
638 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
639 args->map->l_local_scope, NULL, 0,
640 DL_LOOKUP_RETURN_NEWEST, NULL);
641 if (ref != NULL)
642 args->result = DL_SYMBOL_ADDRESS (l, ref);
645 static void
646 version_check_doit (void *a)
648 struct version_check_args *args = (struct version_check_args *) a;
649 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
650 args->dotrace) && args->doexit)
651 /* We cannot start the application. Abort now. */
652 _exit (1);
656 static inline struct link_map *
657 find_needed (const char *name)
659 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
660 unsigned int n = scope->r_nlist;
662 while (n-- > 0)
663 if (_dl_name_match_p (name, scope->r_list[n]))
664 return scope->r_list[n];
666 /* Should never happen. */
667 return NULL;
670 static int
671 match_version (const char *string, struct link_map *map)
673 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
674 ElfW(Verdef) *def;
676 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
677 if (map->l_info[VERDEFTAG] == NULL)
678 /* The file has no symbol versioning. */
679 return 0;
681 def = (ElfW(Verdef) *) ((char *) map->l_addr
682 + map->l_info[VERDEFTAG]->d_un.d_ptr);
683 while (1)
685 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
687 /* Compare the version strings. */
688 if (strcmp (string, strtab + aux->vda_name) == 0)
689 /* Bingo! */
690 return 1;
692 /* If no more definitions we failed to find what we want. */
693 if (def->vd_next == 0)
694 break;
696 /* Next definition. */
697 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
700 return 0;
703 static bool tls_init_tp_called;
705 static void *
706 init_tls (void)
708 /* Number of elements in the static TLS block. */
709 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
711 /* Do not do this twice. The audit interface might have required
712 the DTV interfaces to be set up early. */
713 if (GL(dl_initial_dtv) != NULL)
714 return NULL;
716 /* Allocate the array which contains the information about the
717 dtv slots. We allocate a few entries more than needed to
718 avoid the need for reallocation. */
719 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
721 /* Allocate. */
722 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
723 calloc (sizeof (struct dtv_slotinfo_list)
724 + nelem * sizeof (struct dtv_slotinfo), 1);
725 /* No need to check the return value. If memory allocation failed
726 the program would have been terminated. */
728 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
729 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
730 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
732 /* Fill in the information from the loaded modules. No namespace
733 but the base one can be filled at this time. */
734 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
735 int i = 0;
736 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
737 l = l->l_next)
738 if (l->l_tls_blocksize != 0)
740 /* This is a module with TLS data. Store the map reference.
741 The generation counter is zero. */
742 slotinfo[i].map = l;
743 /* slotinfo[i].gen = 0; */
744 ++i;
746 assert (i == GL(dl_tls_max_dtv_idx));
748 /* Compute the TLS offsets for the various blocks. */
749 _dl_determine_tlsoffset ();
751 /* Construct the static TLS block and the dtv for the initial
752 thread. For some platforms this will include allocating memory
753 for the thread descriptor. The memory for the TLS block will
754 never be freed. It should be allocated accordingly. The dtv
755 array can be changed if dynamic loading requires it. */
756 void *tcbp = _dl_allocate_tls_storage ();
757 if (tcbp == NULL)
758 _dl_fatal_printf ("\
759 cannot allocate TLS data structures for initial thread");
761 /* Store for detection of the special case by __tls_get_addr
762 so it knows not to pass this dtv to the normal realloc. */
763 GL(dl_initial_dtv) = GET_DTV (tcbp);
765 /* And finally install it for the main thread. If ld.so itself uses
766 TLS we know the thread pointer was initialized earlier. */
767 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
768 if (__builtin_expect (lossage != NULL, 0))
769 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
770 tls_init_tp_called = true;
772 return tcbp;
775 #ifdef _LIBC_REENTRANT
776 /* _dl_error_catch_tsd points to this for the single-threaded case.
777 It's reset by the thread library for multithreaded programs. */
778 void ** __attribute__ ((const))
779 _dl_initial_error_catch_tsd (void)
781 static void *data;
782 return &data;
784 #endif
787 static unsigned int
788 do_preload (char *fname, struct link_map *main_map, const char *where)
790 const char *objname;
791 const char *err_str = NULL;
792 struct map_args args;
793 bool malloced;
795 args.str = fname;
796 args.loader = main_map;
797 args.is_preloaded = 1;
798 args.mode = 0;
800 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
802 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
803 if (__builtin_expect (err_str != NULL, 0))
805 _dl_error_printf ("\
806 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
807 fname, where);
808 /* No need to call free, this is still before
809 the libc's malloc is used. */
811 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
812 /* It is no duplicate. */
813 return 1;
815 /* Nothing loaded. */
816 return 0;
819 #if defined SHARED && defined _LIBC_REENTRANT \
820 && defined __rtld_lock_default_lock_recursive
821 static void
822 rtld_lock_default_lock_recursive (void *lock)
824 __rtld_lock_default_lock_recursive (lock);
827 static void
828 rtld_lock_default_unlock_recursive (void *lock)
830 __rtld_lock_default_unlock_recursive (lock);
832 #endif
835 /* The library search path. */
836 static const char *library_path attribute_relro;
837 /* The list preloaded objects. */
838 static const char *preloadlist attribute_relro;
839 /* Nonzero if information about versions has to be printed. */
840 static int version_info attribute_relro;
842 static void
843 dl_main (const ElfW(Phdr) *phdr,
844 ElfW(Word) phnum,
845 ElfW(Addr) *user_entry)
847 const ElfW(Phdr) *ph;
848 enum mode mode;
849 struct link_map *main_map;
850 size_t file_size;
851 char *file;
852 bool has_interp = false;
853 unsigned int i;
854 bool prelinked = false;
855 bool rtld_is_main = false;
856 #ifndef HP_TIMING_NONAVAIL
857 hp_timing_t start;
858 hp_timing_t stop;
859 hp_timing_t diff;
860 #endif
861 void *tcbp = NULL;
863 #ifdef _LIBC_REENTRANT
864 /* Explicit initialization since the reloc would just be more work. */
865 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
866 #endif
868 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
870 #if defined SHARED && defined _LIBC_REENTRANT \
871 && defined __rtld_lock_default_lock_recursive
872 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
873 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
874 #endif
876 /* The explicit initialization here is cheaper than processing the reloc
877 in the _rtld_local definition's initializer. */
878 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
880 /* Process the environment variable which control the behaviour. */
881 process_envvars (&mode);
883 #ifndef HAVE_INLINED_SYSCALLS
884 /* Set up a flag which tells we are just starting. */
885 INTUSE(_dl_starting_up) = 1;
886 #endif
888 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
890 /* Ho ho. We are not the program interpreter! We are the program
891 itself! This means someone ran ld.so as a command. Well, that
892 might be convenient to do sometimes. We support it by
893 interpreting the args like this:
895 ld.so PROGRAM ARGS...
897 The first argument is the name of a file containing an ELF
898 executable we will load and run with the following arguments.
899 To simplify life here, PROGRAM is searched for using the
900 normal rules for shared objects, rather than $PATH or anything
901 like that. We just load it and use its entry point; we don't
902 pay attention to its PT_INTERP command (we are the interpreter
903 ourselves). This is an easy way to test a new ld.so before
904 installing it. */
905 rtld_is_main = true;
907 /* Note the place where the dynamic linker actually came from. */
908 GL(dl_rtld_map).l_name = rtld_progname;
910 while (_dl_argc > 1)
911 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
913 mode = list;
914 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
916 ++_dl_skip_args;
917 --_dl_argc;
918 ++INTUSE(_dl_argv);
920 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
922 mode = verify;
924 ++_dl_skip_args;
925 --_dl_argc;
926 ++INTUSE(_dl_argv);
928 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
929 && _dl_argc > 2)
931 library_path = INTUSE(_dl_argv)[2];
933 _dl_skip_args += 2;
934 _dl_argc -= 2;
935 INTUSE(_dl_argv) += 2;
937 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
938 && _dl_argc > 2)
940 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
942 _dl_skip_args += 2;
943 _dl_argc -= 2;
944 INTUSE(_dl_argv) += 2;
946 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
948 process_dl_audit (INTUSE(_dl_argv)[2]);
950 _dl_skip_args += 2;
951 _dl_argc -= 2;
952 INTUSE(_dl_argv) += 2;
954 else
955 break;
957 /* If we have no further argument the program was called incorrectly.
958 Grant the user some education. */
959 if (_dl_argc < 2)
960 _dl_fatal_printf ("\
961 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
962 You have invoked `ld.so', the helper program for shared library executables.\n\
963 This program usually lives in the file `/lib/ld.so', and special directives\n\
964 in executable files using ELF shared libraries tell the system's program\n\
965 loader to load the helper program from this file. This helper program loads\n\
966 the shared libraries needed by the program executable, prepares the program\n\
967 to run, and runs it. You may invoke this helper program directly from the\n\
968 command line to load and run an ELF executable file; this is like executing\n\
969 that file itself, but always uses this helper program from the file you\n\
970 specified, instead of the helper program file specified in the executable\n\
971 file you run. This is mostly of use for maintainers to test new versions\n\
972 of this helper program; chances are you did not intend to run this program.\n\
974 --list list all dependencies and how they are resolved\n\
975 --verify verify that given object really is a dynamically linked\n\
976 object we can handle\n\
977 --library-path PATH use given PATH instead of content of the environment\n\
978 variable LD_LIBRARY_PATH\n\
979 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
980 in LIST\n");
982 ++_dl_skip_args;
983 --_dl_argc;
984 ++INTUSE(_dl_argv);
986 /* The initialization of _dl_stack_flags done below assumes the
987 executable's PT_GNU_STACK may have been honored by the kernel, and
988 so a PT_GNU_STACK with PF_X set means the stack started out with
989 execute permission. However, this is not really true if the
990 dynamic linker is the executable the kernel loaded. For this
991 case, we must reinitialize _dl_stack_flags to match the dynamic
992 linker itself. If the dynamic linker was built with a
993 PT_GNU_STACK, then the kernel may have loaded us with a
994 nonexecutable stack that we will have to make executable when we
995 load the program below unless it has a PT_GNU_STACK indicating
996 nonexecutable stack is ok. */
998 for (ph = phdr; ph < &phdr[phnum]; ++ph)
999 if (ph->p_type == PT_GNU_STACK)
1001 GL(dl_stack_flags) = ph->p_flags;
1002 break;
1005 if (__builtin_expect (mode, normal) == verify)
1007 const char *objname;
1008 const char *err_str = NULL;
1009 struct map_args args;
1010 bool malloced;
1012 args.str = rtld_progname;
1013 args.loader = NULL;
1014 args.is_preloaded = 0;
1015 args.mode = __RTLD_OPENEXEC;
1016 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1017 &args);
1018 if (__builtin_expect (err_str != NULL, 0))
1019 /* We don't free the returned string, the programs stops
1020 anyway. */
1021 _exit (EXIT_FAILURE);
1023 else
1025 HP_TIMING_NOW (start);
1026 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1027 __RTLD_OPENEXEC, LM_ID_BASE);
1028 HP_TIMING_NOW (stop);
1030 HP_TIMING_DIFF (load_time, start, stop);
1033 /* Now the map for the main executable is available. */
1034 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1036 phdr = main_map->l_phdr;
1037 phnum = main_map->l_phnum;
1038 /* We overwrite here a pointer to a malloc()ed string. But since
1039 the malloc() implementation used at this point is the dummy
1040 implementations which has no real free() function it does not
1041 makes sense to free the old string first. */
1042 main_map->l_name = (char *) "";
1043 *user_entry = main_map->l_entry;
1045 else
1047 /* Create a link_map for the executable itself.
1048 This will be what dlopen on "" returns. */
1049 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1050 __RTLD_OPENEXEC, LM_ID_BASE);
1051 assert (main_map != NULL);
1052 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1053 main_map->l_phdr = phdr;
1054 main_map->l_phnum = phnum;
1055 main_map->l_entry = *user_entry;
1057 /* At this point we are in a bit of trouble. We would have to
1058 fill in the values for l_dev and l_ino. But in general we
1059 do not know where the file is. We also do not handle AT_EXECFD
1060 even if it would be passed up.
1062 We leave the values here defined to 0. This is normally no
1063 problem as the program code itself is normally no shared
1064 object and therefore cannot be loaded dynamically. Nothing
1065 prevent the use of dynamic binaries and in these situations
1066 we might get problems. We might not be able to find out
1067 whether the object is already loaded. But since there is no
1068 easy way out and because the dynamic binary must also not
1069 have an SONAME we ignore this program for now. If it becomes
1070 a problem we can force people using SONAMEs. */
1072 /* We delay initializing the path structure until we got the dynamic
1073 information for the program. */
1076 main_map->l_map_end = 0;
1077 main_map->l_text_end = 0;
1078 /* Perhaps the executable has no PT_LOAD header entries at all. */
1079 main_map->l_map_start = ~0;
1080 /* And it was opened directly. */
1081 ++main_map->l_direct_opencount;
1083 /* Scan the program header table for the dynamic section. */
1084 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1085 switch (ph->p_type)
1087 case PT_PHDR:
1088 /* Find out the load address. */
1089 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1090 break;
1091 case PT_DYNAMIC:
1092 /* This tells us where to find the dynamic section,
1093 which tells us everything we need to do. */
1094 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1095 break;
1096 case PT_INTERP:
1097 /* This "interpreter segment" was used by the program loader to
1098 find the program interpreter, which is this program itself, the
1099 dynamic linker. We note what name finds us, so that a future
1100 dlopen call or DT_NEEDED entry, for something that wants to link
1101 against the dynamic linker as a shared library, will know that
1102 the shared object is already loaded. */
1103 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1104 + ph->p_vaddr);
1105 /* _dl_rtld_libname.next = NULL; Already zero. */
1106 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1108 /* Ordinarilly, we would get additional names for the loader from
1109 our DT_SONAME. This can't happen if we were actually linked as
1110 a static executable (detect this case when we have no DYNAMIC).
1111 If so, assume the filename component of the interpreter path to
1112 be our SONAME, and add it to our name list. */
1113 if (GL(dl_rtld_map).l_ld == NULL)
1115 const char *p = NULL;
1116 const char *cp = _dl_rtld_libname.name;
1118 /* Find the filename part of the path. */
1119 while (*cp != '\0')
1120 if (*cp++ == '/')
1121 p = cp;
1123 if (p != NULL)
1125 _dl_rtld_libname2.name = p;
1126 /* _dl_rtld_libname2.next = NULL; Already zero. */
1127 _dl_rtld_libname.next = &_dl_rtld_libname2;
1131 has_interp = true;
1132 break;
1133 case PT_LOAD:
1135 ElfW(Addr) mapstart;
1136 ElfW(Addr) allocend;
1138 /* Remember where the main program starts in memory. */
1139 mapstart = (main_map->l_addr + (ph->p_vaddr & ~(ph->p_align - 1)));
1140 if (main_map->l_map_start > mapstart)
1141 main_map->l_map_start = mapstart;
1143 /* Also where it ends. */
1144 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1145 if (main_map->l_map_end < allocend)
1146 main_map->l_map_end = allocend;
1147 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1148 main_map->l_text_end = allocend;
1150 break;
1152 case PT_TLS:
1153 if (ph->p_memsz > 0)
1155 /* Note that in the case the dynamic linker we duplicate work
1156 here since we read the PT_TLS entry already in
1157 _dl_start_final. But the result is repeatable so do not
1158 check for this special but unimportant case. */
1159 main_map->l_tls_blocksize = ph->p_memsz;
1160 main_map->l_tls_align = ph->p_align;
1161 if (ph->p_align == 0)
1162 main_map->l_tls_firstbyte_offset = 0;
1163 else
1164 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1165 & (ph->p_align - 1));
1166 main_map->l_tls_initimage_size = ph->p_filesz;
1167 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1169 /* This image gets the ID one. */
1170 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1172 break;
1174 case PT_GNU_STACK:
1175 GL(dl_stack_flags) = ph->p_flags;
1176 break;
1178 case PT_GNU_RELRO:
1179 main_map->l_relro_addr = ph->p_vaddr;
1180 main_map->l_relro_size = ph->p_memsz;
1181 break;
1184 /* Adjust the address of the TLS initialization image in case
1185 the executable is actually an ET_DYN object. */
1186 if (main_map->l_tls_initimage != NULL)
1187 main_map->l_tls_initimage
1188 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1189 if (! main_map->l_map_end)
1190 main_map->l_map_end = ~0;
1191 if (! main_map->l_text_end)
1192 main_map->l_text_end = ~0;
1193 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1195 /* We were invoked directly, so the program might not have a
1196 PT_INTERP. */
1197 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1198 /* _dl_rtld_libname.next = NULL; Already zero. */
1199 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1201 else
1202 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1204 /* If the current libname is different from the SONAME, add the
1205 latter as well. */
1206 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1207 && strcmp (GL(dl_rtld_map).l_libname->name,
1208 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1209 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1211 static struct libname_list newname;
1212 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1213 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1214 newname.next = NULL;
1215 newname.dont_free = 1;
1217 assert (GL(dl_rtld_map).l_libname->next == NULL);
1218 GL(dl_rtld_map).l_libname->next = &newname;
1220 /* The ld.so must be relocated since otherwise loading audit modules
1221 will fail since they reuse the very same ld.so. */
1222 assert (GL(dl_rtld_map).l_relocated);
1224 if (! rtld_is_main)
1226 /* Extract the contents of the dynamic section for easy access. */
1227 elf_get_dynamic_info (main_map, NULL);
1228 /* Set up our cache of pointers into the hash table. */
1229 _dl_setup_hash (main_map);
1232 if (__builtin_expect (mode, normal) == verify)
1234 /* We were called just to verify that this is a dynamic
1235 executable using us as the program interpreter. Exit with an
1236 error if we were not able to load the binary or no interpreter
1237 is specified (i.e., this is no dynamically linked binary. */
1238 if (main_map->l_ld == NULL)
1239 _exit (1);
1241 /* We allow here some platform specific code. */
1242 #ifdef DISTINGUISH_LIB_VERSIONS
1243 DISTINGUISH_LIB_VERSIONS;
1244 #endif
1245 _exit (has_interp ? 0 : 2);
1248 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1249 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1250 /* Set up the data structures for the system-supplied DSO early,
1251 so they can influence _dl_init_paths. */
1252 if (GLRO(dl_sysinfo_dso) != NULL)
1254 /* Do an abridged version of the work _dl_map_object_from_fd would do
1255 to map in the object. It's already mapped and prelinked (and
1256 better be, since it's read-only and so we couldn't relocate it).
1257 We just want our data structures to describe it as if we had just
1258 mapped and relocated it normally. */
1259 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1260 0, LM_ID_BASE);
1261 if (__builtin_expect (l != NULL, 1))
1263 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1265 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1266 + GLRO(dl_sysinfo_dso)->e_phoff);
1267 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1268 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1270 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1271 if (ph->p_type == PT_DYNAMIC)
1273 l->l_ld = (void *) ph->p_vaddr;
1274 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1276 else if (ph->p_type == PT_LOAD)
1278 if (! l->l_addr)
1279 l->l_addr = ph->p_vaddr;
1280 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1281 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1282 if ((ph->p_flags & PF_X)
1283 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1284 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1286 else
1287 /* There must be no TLS segment. */
1288 assert (ph->p_type != PT_TLS);
1290 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1291 l->l_addr = l->l_map_start - l->l_addr;
1292 l->l_map_end += l->l_addr;
1293 l->l_text_end += l->l_addr;
1294 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1295 elf_get_dynamic_info (l, dyn_temp);
1296 _dl_setup_hash (l);
1297 l->l_relocated = 1;
1299 /* Initialize l_local_scope to contain just this map. This allows
1300 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1301 So we create a single entry list pointing to l_real as its only
1302 element */
1303 l->l_local_scope[0]->r_nlist = 1;
1304 l->l_local_scope[0]->r_list = &l->l_real;
1306 /* Now that we have the info handy, use the DSO image's soname
1307 so this object can be looked up by name. Note that we do not
1308 set l_name here. That field gives the file name of the DSO,
1309 and this DSO is not associated with any file. */
1310 if (l->l_info[DT_SONAME] != NULL)
1312 /* Work around a kernel problem. The kernel cannot handle
1313 addresses in the vsyscall DSO pages in writev() calls. */
1314 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1315 + l->l_info[DT_SONAME]->d_un.d_val);
1316 size_t len = strlen (dsoname);
1317 char *copy = malloc (len);
1318 if (copy == NULL)
1319 _dl_fatal_printf ("out of memory\n");
1320 l->l_libname->name = memcpy (copy, dsoname, len);
1323 /* Rearrange the list so this DSO appears after rtld_map. */
1324 assert (l->l_next == NULL);
1325 assert (l->l_prev == main_map);
1326 GL(dl_rtld_map).l_next = l;
1327 l->l_prev = &GL(dl_rtld_map);
1328 first_preload = &l->l_next;
1330 /* We have a prelinked DSO preloaded by the system. */
1331 GLRO(dl_sysinfo_map) = l;
1332 # ifdef NEED_DL_SYSINFO
1333 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1334 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1335 # endif
1338 #endif
1340 #ifdef DL_SYSDEP_OSCHECK
1341 DL_SYSDEP_OSCHECK (dl_fatal);
1342 #endif
1344 /* Initialize the data structures for the search paths for shared
1345 objects. */
1346 _dl_init_paths (library_path);
1348 /* Initialize _r_debug. */
1349 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1350 LM_ID_BASE);
1351 r->r_state = RT_CONSISTENT;
1353 /* Put the link_map for ourselves on the chain so it can be found by
1354 name. Note that at this point the global chain of link maps contains
1355 exactly one element, which is pointed to by dl_loaded. */
1356 if (! GL(dl_rtld_map).l_name)
1357 /* If not invoked directly, the dynamic linker shared object file was
1358 found by the PT_INTERP name. */
1359 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1360 GL(dl_rtld_map).l_type = lt_library;
1361 main_map->l_next = &GL(dl_rtld_map);
1362 GL(dl_rtld_map).l_prev = main_map;
1363 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1364 ++GL(dl_load_adds);
1366 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1367 to not using bias for non-prelinked PIEs and libraries
1368 and using it for executables or prelinked PIEs or libraries. */
1369 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1370 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1372 /* Set up the program header information for the dynamic linker
1373 itself. It is needed in the dl_iterate_phdr() callbacks. */
1374 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1375 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1376 + rtld_ehdr->e_phoff);
1377 GL(dl_rtld_map).l_phdr = rtld_phdr;
1378 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1381 /* PT_GNU_RELRO is usually the last phdr. */
1382 size_t cnt = rtld_ehdr->e_phnum;
1383 while (cnt-- > 0)
1384 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1386 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1387 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1388 break;
1391 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1392 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1393 /* Assign a module ID. Do this before loading any audit modules. */
1394 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1396 /* If we have auditing DSOs to load, do it now. */
1397 if (__builtin_expect (audit_list != NULL, 0))
1399 /* Iterate over all entries in the list. The order is important. */
1400 struct audit_ifaces *last_audit = NULL;
1401 struct audit_list *al = audit_list->next;
1404 int tls_idx = GL(dl_tls_max_dtv_idx);
1406 /* Now it is time to determine the layout of the static TLS
1407 block and allocate it for the initial thread. Note that we
1408 always allocate the static block, we never defer it even if
1409 no DF_STATIC_TLS bit is set. The reason is that we know
1410 glibc will use the static model. */
1412 /* Since we start using the auditing DSOs right away we need to
1413 initialize the data structures now. */
1414 tcbp = init_tls ();
1416 struct dlmopen_args dlmargs;
1417 dlmargs.fname = al->name;
1418 dlmargs.map = NULL;
1420 const char *objname;
1421 const char *err_str = NULL;
1422 bool malloced;
1423 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1424 &dlmargs);
1425 if (__builtin_expect (err_str != NULL, 0))
1427 not_loaded:
1428 _dl_error_printf ("\
1429 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1430 al->name, err_str);
1431 if (malloced)
1432 free ((char *) err_str);
1434 else
1436 struct lookup_args largs;
1437 largs.name = "la_version";
1438 largs.map = dlmargs.map;
1440 /* Check whether the interface version matches. */
1441 (void) _dl_catch_error (&objname, &err_str, &malloced,
1442 lookup_doit, &largs);
1444 unsigned int (*laversion) (unsigned int);
1445 unsigned int lav;
1446 if (err_str == NULL
1447 && (laversion = largs.result) != NULL
1448 && (lav = laversion (LAV_CURRENT)) > 0
1449 && lav <= LAV_CURRENT)
1451 /* Allocate structure for the callback function pointers.
1452 This call can never fail. */
1453 union
1455 struct audit_ifaces ifaces;
1456 #define naudit_ifaces 8
1457 void (*fptr[naudit_ifaces]) (void);
1458 } *newp = malloc (sizeof (*newp));
1460 /* Names of the auditing interfaces. All in one
1461 long string. */
1462 static const char audit_iface_names[] =
1463 "la_activity\0"
1464 "la_objsearch\0"
1465 "la_objopen\0"
1466 "la_preinit\0"
1467 #if __ELF_NATIVE_CLASS == 32
1468 "la_symbind32\0"
1469 #elif __ELF_NATIVE_CLASS == 64
1470 "la_symbind64\0"
1471 #else
1472 # error "__ELF_NATIVE_CLASS must be defined"
1473 #endif
1474 #define STRING(s) __STRING (s)
1475 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1476 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1477 "la_objclose\0";
1478 unsigned int cnt = 0;
1479 const char *cp = audit_iface_names;
1482 largs.name = cp;
1483 (void) _dl_catch_error (&objname, &err_str, &malloced,
1484 lookup_doit, &largs);
1486 /* Store the pointer. */
1487 if (err_str == NULL && largs.result != NULL)
1489 newp->fptr[cnt] = largs.result;
1491 /* The dynamic linker link map is statically
1492 allocated, initialize the data now. */
1493 GL(dl_rtld_map).l_audit[cnt].cookie
1494 = (intptr_t) &GL(dl_rtld_map);
1496 else
1497 newp->fptr[cnt] = NULL;
1498 ++cnt;
1500 cp = (char *) rawmemchr (cp, '\0') + 1;
1502 while (*cp != '\0');
1503 assert (cnt == naudit_ifaces);
1505 /* Now append the new auditing interface to the list. */
1506 newp->ifaces.next = NULL;
1507 if (last_audit == NULL)
1508 last_audit = GLRO(dl_audit) = &newp->ifaces;
1509 else
1510 last_audit = last_audit->next = &newp->ifaces;
1511 ++GLRO(dl_naudit);
1513 /* Mark the DSO as being used for auditing. */
1514 dlmargs.map->l_auditing = 1;
1516 else
1518 /* We cannot use the DSO, it does not have the
1519 appropriate interfaces or it expects something
1520 more recent. */
1521 #ifndef NDEBUG
1522 Lmid_t ns = dlmargs.map->l_ns;
1523 #endif
1524 _dl_close (dlmargs.map);
1526 /* Make sure the namespace has been cleared entirely. */
1527 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1528 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1530 GL(dl_tls_max_dtv_idx) = tls_idx;
1531 goto not_loaded;
1535 al = al->next;
1537 while (al != audit_list->next);
1539 /* If we have any auditing modules, announce that we already
1540 have two objects loaded. */
1541 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1543 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1545 for (unsigned int outer = 0; outer < 2; ++outer)
1547 struct audit_ifaces *afct = GLRO(dl_audit);
1548 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1550 if (afct->objopen != NULL)
1552 ls[outer]->l_audit[cnt].bindflags
1553 = afct->objopen (ls[outer], LM_ID_BASE,
1554 &ls[outer]->l_audit[cnt].cookie);
1556 ls[outer]->l_audit_any_plt
1557 |= ls[outer]->l_audit[cnt].bindflags != 0;
1560 afct = afct->next;
1566 /* Set up debugging before the debugger is notified for the first time. */
1567 #ifdef ELF_MACHINE_DEBUG_SETUP
1568 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1569 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1570 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1571 #else
1572 if (main_map->l_info[DT_DEBUG] != NULL)
1573 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1574 with the run-time address of the r_debug structure */
1575 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1577 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1578 case you run gdb on the dynamic linker directly. */
1579 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1580 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1581 #endif
1583 /* We start adding objects. */
1584 r->r_state = RT_ADD;
1585 _dl_debug_state ();
1587 /* Auditing checkpoint: we are ready to signal that the initial map
1588 is being constructed. */
1589 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1591 struct audit_ifaces *afct = GLRO(dl_audit);
1592 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1594 if (afct->activity != NULL)
1595 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1597 afct = afct->next;
1601 /* We have two ways to specify objects to preload: via environment
1602 variable and via the file /etc/ld.so.preload. The latter can also
1603 be used when security is enabled. */
1604 assert (*first_preload == NULL);
1605 struct link_map **preloads = NULL;
1606 unsigned int npreloads = 0;
1608 if (__builtin_expect (preloadlist != NULL, 0))
1610 /* The LD_PRELOAD environment variable gives list of libraries
1611 separated by white space or colons that are loaded before the
1612 executable's dependencies and prepended to the global scope
1613 list. If the binary is running setuid all elements
1614 containing a '/' are ignored since it is insecure. */
1615 char *list = strdupa (preloadlist);
1616 char *p;
1618 HP_TIMING_NOW (start);
1620 /* Prevent optimizing strsep. Speed is not important here. */
1621 while ((p = (strsep) (&list, " :")) != NULL)
1622 if (p[0] != '\0'
1623 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1624 || strchr (p, '/') == NULL))
1625 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1627 HP_TIMING_NOW (stop);
1628 HP_TIMING_DIFF (diff, start, stop);
1629 HP_TIMING_ACCUM_NT (load_time, diff);
1632 /* There usually is no ld.so.preload file, it should only be used
1633 for emergencies and testing. So the open call etc should usually
1634 fail. Using access() on a non-existing file is faster than using
1635 open(). So we do this first. If it succeeds we do almost twice
1636 the work but this does not matter, since it is not for production
1637 use. */
1638 static const char preload_file[] = "/etc/ld.so.preload";
1639 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1641 /* Read the contents of the file. */
1642 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1643 PROT_READ | PROT_WRITE);
1644 if (__builtin_expect (file != MAP_FAILED, 0))
1646 /* Parse the file. It contains names of libraries to be loaded,
1647 separated by white spaces or `:'. It may also contain
1648 comments introduced by `#'. */
1649 char *problem;
1650 char *runp;
1651 size_t rest;
1653 /* Eliminate comments. */
1654 runp = file;
1655 rest = file_size;
1656 while (rest > 0)
1658 char *comment = memchr (runp, '#', rest);
1659 if (comment == NULL)
1660 break;
1662 rest -= comment - runp;
1664 *comment = ' ';
1665 while (--rest > 0 && *++comment != '\n');
1668 /* We have one problematic case: if we have a name at the end of
1669 the file without a trailing terminating characters, we cannot
1670 place the \0. Handle the case separately. */
1671 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1672 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1674 problem = &file[file_size];
1675 while (problem > file && problem[-1] != ' '
1676 && problem[-1] != '\t'
1677 && problem[-1] != '\n' && problem[-1] != ':')
1678 --problem;
1680 if (problem > file)
1681 problem[-1] = '\0';
1683 else
1685 problem = NULL;
1686 file[file_size - 1] = '\0';
1689 HP_TIMING_NOW (start);
1691 if (file != problem)
1693 char *p;
1694 runp = file;
1695 while ((p = strsep (&runp, ": \t\n")) != NULL)
1696 if (p[0] != '\0')
1697 npreloads += do_preload (p, main_map, preload_file);
1700 if (problem != NULL)
1702 char *p = strndupa (problem, file_size - (problem - file));
1704 npreloads += do_preload (p, main_map, preload_file);
1707 HP_TIMING_NOW (stop);
1708 HP_TIMING_DIFF (diff, start, stop);
1709 HP_TIMING_ACCUM_NT (load_time, diff);
1711 /* We don't need the file anymore. */
1712 __munmap (file, file_size);
1716 if (__builtin_expect (*first_preload != NULL, 0))
1718 /* Set up PRELOADS with a vector of the preloaded libraries. */
1719 struct link_map *l = *first_preload;
1720 preloads = __alloca (npreloads * sizeof preloads[0]);
1721 i = 0;
1724 preloads[i++] = l;
1725 l = l->l_next;
1726 } while (l);
1727 assert (i == npreloads);
1730 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1731 specified some libraries to load, these are inserted before the actual
1732 dependencies in the executable's searchlist for symbol resolution. */
1733 HP_TIMING_NOW (start);
1734 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1735 HP_TIMING_NOW (stop);
1736 HP_TIMING_DIFF (diff, start, stop);
1737 HP_TIMING_ACCUM_NT (load_time, diff);
1739 /* Mark all objects as being in the global scope. */
1740 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1741 main_map->l_searchlist.r_list[--i]->l_global = 1;
1743 #ifndef MAP_ANON
1744 /* We are done mapping things, so close the zero-fill descriptor. */
1745 __close (_dl_zerofd);
1746 _dl_zerofd = -1;
1747 #endif
1749 /* Remove _dl_rtld_map from the chain. */
1750 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1751 if (GL(dl_rtld_map).l_next != NULL)
1752 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1754 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1755 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1756 break;
1758 bool rtld_multiple_ref = false;
1759 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1761 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1762 put it back in the list of visible objects. We insert it into the
1763 chain in symbol search order because gdb uses the chain's order as
1764 its symbol search order. */
1765 rtld_multiple_ref = true;
1767 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1768 if (__builtin_expect (mode, normal) == normal)
1770 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1771 ? main_map->l_searchlist.r_list[i + 1]
1772 : NULL);
1773 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1774 if (GLRO(dl_sysinfo_map) != NULL
1775 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1776 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1777 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1778 #endif
1780 else
1781 /* In trace mode there might be an invisible object (which we
1782 could not find) after the previous one in the search list.
1783 In this case it doesn't matter much where we put the
1784 interpreter object, so we just initialize the list pointer so
1785 that the assertion below holds. */
1786 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1788 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1789 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1790 if (GL(dl_rtld_map).l_next != NULL)
1792 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1793 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1797 /* Now let us see whether all libraries are available in the
1798 versions we need. */
1800 struct version_check_args args;
1801 args.doexit = mode == normal;
1802 args.dotrace = mode == trace;
1803 _dl_receive_error (print_missing_version, version_check_doit, &args);
1806 /* We do not initialize any of the TLS functionality unless any of the
1807 initial modules uses TLS. This makes dynamic loading of modules with
1808 TLS impossible, but to support it requires either eagerly doing setup
1809 now or lazily doing it later. Doing it now makes us incompatible with
1810 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1811 used. Trying to do it lazily is too hairy to try when there could be
1812 multiple threads (from a non-TLS-using libpthread). */
1813 bool was_tls_init_tp_called = tls_init_tp_called;
1814 if (tcbp == NULL)
1815 tcbp = init_tls ();
1817 /* Set up the stack checker's canary. */
1818 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
1819 #ifdef THREAD_SET_STACK_GUARD
1820 THREAD_SET_STACK_GUARD (stack_chk_guard);
1821 #else
1822 __stack_chk_guard = stack_chk_guard;
1823 #endif
1825 /* Set up the pointer guard as well, if necessary. */
1826 if (GLRO(dl_pointer_guard))
1828 // XXX If it is cheap, we should use a separate value.
1829 uintptr_t pointer_chk_guard = stack_chk_guard;
1830 #ifndef HP_TIMING_NONAVAIL
1831 hp_timing_t now;
1832 HP_TIMING_NOW (now);
1833 pointer_chk_guard ^= now;
1834 #endif
1835 #ifdef THREAD_SET_POINTER_GUARD
1836 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
1837 #endif
1838 __pointer_chk_guard_local = pointer_chk_guard;
1841 if (__builtin_expect (mode, normal) != normal)
1843 /* We were run just to list the shared libraries. It is
1844 important that we do this before real relocation, because the
1845 functions we call below for output may no longer work properly
1846 after relocation. */
1847 struct link_map *l;
1849 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1851 struct r_scope_elem *scope = &main_map->l_searchlist;
1853 for (i = 0; i < scope->r_nlist; i++)
1855 l = scope->r_list [i];
1856 if (l->l_faked)
1858 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1859 continue;
1861 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1862 GLRO(dl_trace_prelink_map) = l;
1863 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1864 l->l_libname->name[0] ? l->l_libname->name
1865 : rtld_progname ?: "<main program>",
1866 l->l_name[0] ? l->l_name
1867 : rtld_progname ?: "<main program>",
1868 (int) sizeof l->l_map_start * 2,
1869 (size_t) l->l_map_start,
1870 (int) sizeof l->l_addr * 2,
1871 (size_t) l->l_addr);
1873 if (l->l_tls_modid)
1874 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1875 (int) sizeof l->l_tls_offset * 2,
1876 (size_t) l->l_tls_offset);
1877 else
1878 _dl_printf ("\n");
1881 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1883 /* Look through the dependencies of the main executable
1884 and determine which of them is not actually
1885 required. */
1886 struct link_map *l = main_map;
1888 /* Relocate the main executable. */
1889 struct relocate_args args = { .l = l, .lazy = GLRO(dl_lazy) };
1890 _dl_receive_error (print_unresolved, relocate_doit, &args);
1892 /* This loop depends on the dependencies of the executable to
1893 correspond in number and order to the DT_NEEDED entries. */
1894 ElfW(Dyn) *dyn = main_map->l_ld;
1895 bool first = true;
1896 while (dyn->d_tag != DT_NULL)
1898 if (dyn->d_tag == DT_NEEDED)
1900 l = l->l_next;
1902 if (!l->l_used)
1904 if (first)
1906 _dl_printf ("Unused direct dependencies:\n");
1907 first = false;
1910 _dl_printf ("\t%s\n", l->l_name);
1914 ++dyn;
1917 _exit (first != true);
1919 else if (! main_map->l_info[DT_NEEDED])
1920 _dl_printf ("\tstatically linked\n");
1921 else
1923 for (l = main_map->l_next; l; l = l->l_next)
1924 if (l->l_faked)
1925 /* The library was not found. */
1926 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1927 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1928 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1929 (int) sizeof l->l_map_start * 2,
1930 (size_t) l->l_map_start);
1931 else
1932 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1933 l->l_name, (int) sizeof l->l_map_start * 2,
1934 (size_t) l->l_map_start);
1937 if (__builtin_expect (mode, trace) != trace)
1938 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1940 const ElfW(Sym) *ref = NULL;
1941 ElfW(Addr) loadbase;
1942 lookup_t result;
1944 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1945 &ref, main_map->l_scope,
1946 NULL, ELF_RTYPE_CLASS_PLT,
1947 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1949 loadbase = LOOKUP_VALUE_ADDRESS (result);
1951 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1952 INTUSE(_dl_argv)[i],
1953 (int) sizeof ref->st_value * 2,
1954 (size_t) ref->st_value,
1955 (int) sizeof loadbase * 2, (size_t) loadbase);
1957 else
1959 /* If LD_WARN is set, warn about undefined symbols. */
1960 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1962 /* We have to do symbol dependency testing. */
1963 struct relocate_args args;
1964 struct link_map *l;
1966 args.lazy = GLRO(dl_lazy);
1968 l = main_map;
1969 while (l->l_next != NULL)
1970 l = l->l_next;
1973 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1975 args.l = l;
1976 _dl_receive_error (print_unresolved, relocate_doit,
1977 &args);
1979 l = l->l_prev;
1981 while (l != NULL);
1983 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1984 && rtld_multiple_ref)
1986 /* Mark the link map as not yet relocated again. */
1987 GL(dl_rtld_map).l_relocated = 0;
1988 _dl_relocate_object (&GL(dl_rtld_map),
1989 main_map->l_scope, 0, 0);
1992 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
1993 if (version_info)
1995 /* Print more information. This means here, print information
1996 about the versions needed. */
1997 int first = 1;
1998 struct link_map *map;
2000 for (map = main_map; map != NULL; map = map->l_next)
2002 const char *strtab;
2003 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2004 ElfW(Verneed) *ent;
2006 if (dyn == NULL)
2007 continue;
2009 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2010 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2012 if (first)
2014 _dl_printf ("\n\tVersion information:\n");
2015 first = 0;
2018 _dl_printf ("\t%s:\n",
2019 map->l_name[0] ? map->l_name : rtld_progname);
2021 while (1)
2023 ElfW(Vernaux) *aux;
2024 struct link_map *needed;
2026 needed = find_needed (strtab + ent->vn_file);
2027 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2029 while (1)
2031 const char *fname = NULL;
2033 if (needed != NULL
2034 && match_version (strtab + aux->vna_name,
2035 needed))
2036 fname = needed->l_name;
2038 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2039 strtab + ent->vn_file,
2040 strtab + aux->vna_name,
2041 aux->vna_flags & VER_FLG_WEAK
2042 ? "[WEAK] " : "",
2043 fname ?: "not found");
2045 if (aux->vna_next == 0)
2046 /* No more symbols. */
2047 break;
2049 /* Next symbol. */
2050 aux = (ElfW(Vernaux) *) ((char *) aux
2051 + aux->vna_next);
2054 if (ent->vn_next == 0)
2055 /* No more dependencies. */
2056 break;
2058 /* Next dependency. */
2059 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2065 _exit (0);
2068 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2069 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2070 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2072 ElfW(Lib) *liblist, *liblistend;
2073 struct link_map **r_list, **r_listend, *l;
2074 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2076 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2077 liblist = (ElfW(Lib) *)
2078 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2079 liblistend = (ElfW(Lib) *)
2080 ((char *) liblist +
2081 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2082 r_list = main_map->l_searchlist.r_list;
2083 r_listend = r_list + main_map->l_searchlist.r_nlist;
2085 for (; r_list < r_listend && liblist < liblistend; r_list++)
2087 l = *r_list;
2089 if (l == main_map)
2090 continue;
2092 /* If the library is not mapped where it should, fail. */
2093 if (l->l_addr)
2094 break;
2096 /* Next, check if checksum matches. */
2097 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2098 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2099 != liblist->l_checksum)
2100 break;
2102 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2103 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2104 != liblist->l_time_stamp)
2105 break;
2107 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2108 break;
2110 ++liblist;
2114 if (r_list == r_listend && liblist == liblistend)
2115 prelinked = true;
2117 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2118 _dl_debug_printf ("\nprelink checking: %s\n",
2119 prelinked ? "ok" : "failed");
2123 /* Now set up the variable which helps the assembler startup code. */
2124 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2126 /* Save the information about the original global scope list since
2127 we need it in the memory handling later. */
2128 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2130 if (prelinked)
2132 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2134 ElfW(Rela) *conflict, *conflictend;
2135 #ifndef HP_TIMING_NONAVAIL
2136 hp_timing_t start;
2137 hp_timing_t stop;
2138 #endif
2140 HP_TIMING_NOW (start);
2141 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2142 conflict = (ElfW(Rela) *)
2143 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2144 conflictend = (ElfW(Rela) *)
2145 ((char *) conflict
2146 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2147 _dl_resolve_conflicts (main_map, conflict, conflictend);
2148 HP_TIMING_NOW (stop);
2149 HP_TIMING_DIFF (relocate_time, start, stop);
2153 /* Mark all the objects so we know they have been already relocated. */
2154 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2156 l->l_relocated = 1;
2157 if (l->l_relro_size)
2158 _dl_protect_relro (l);
2160 /* Add object to slot information data if necessasy. */
2161 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2162 _dl_add_to_slotinfo (l);
2165 _dl_sysdep_start_cleanup ();
2167 else
2169 /* Now we have all the objects loaded. Relocate them all except for
2170 the dynamic linker itself. We do this in reverse order so that copy
2171 relocs of earlier objects overwrite the data written by later
2172 objects. We do not re-relocate the dynamic linker itself in this
2173 loop because that could result in the GOT entries for functions we
2174 call being changed, and that would break us. It is safe to relocate
2175 the dynamic linker out of order because it has no copy relocs (we
2176 know that because it is self-contained). */
2178 int consider_profiling = GLRO(dl_profile) != NULL;
2179 #ifndef HP_TIMING_NONAVAIL
2180 hp_timing_t start;
2181 hp_timing_t stop;
2182 #endif
2184 /* If we are profiling we also must do lazy reloaction. */
2185 GLRO(dl_lazy) |= consider_profiling;
2187 struct link_map *l = main_map;
2188 while (l->l_next)
2189 l = l->l_next;
2191 HP_TIMING_NOW (start);
2194 /* While we are at it, help the memory handling a bit. We have to
2195 mark some data structures as allocated with the fake malloc()
2196 implementation in ld.so. */
2197 struct libname_list *lnp = l->l_libname->next;
2199 while (__builtin_expect (lnp != NULL, 0))
2201 lnp->dont_free = 1;
2202 lnp = lnp->next;
2205 if (l != &GL(dl_rtld_map))
2206 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy),
2207 consider_profiling);
2209 /* Add object to slot information data if necessasy. */
2210 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2211 _dl_add_to_slotinfo (l);
2213 l = l->l_prev;
2215 while (l);
2216 HP_TIMING_NOW (stop);
2218 HP_TIMING_DIFF (relocate_time, start, stop);
2220 /* Do any necessary cleanups for the startup OS interface code.
2221 We do these now so that no calls are made after rtld re-relocation
2222 which might be resolved to different functions than we expect.
2223 We cannot do this before relocating the other objects because
2224 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2225 _dl_sysdep_start_cleanup ();
2227 /* Now enable profiling if needed. Like the previous call,
2228 this has to go here because the calls it makes should use the
2229 rtld versions of the functions (particularly calloc()), but it
2230 needs to have _dl_profile_map set up by the relocator. */
2231 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2232 /* We must prepare the profiling. */
2233 _dl_start_profile ();
2236 #ifndef NONTLS_INIT_TP
2237 # define NONTLS_INIT_TP do { } while (0)
2238 #endif
2240 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2241 ++GL(dl_tls_generation);
2243 /* Now that we have completed relocation, the initializer data
2244 for the TLS blocks has its final values and we can copy them
2245 into the main thread's TLS area, which we allocated above. */
2246 _dl_allocate_tls_init (tcbp);
2248 /* And finally install it for the main thread. If ld.so itself uses
2249 TLS we know the thread pointer was initialized earlier. */
2250 if (! tls_init_tp_called)
2252 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2253 if (__builtin_expect (lossage != NULL, 0))
2254 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2255 lossage);
2258 if (! prelinked && rtld_multiple_ref)
2260 /* There was an explicit ref to the dynamic linker as a shared lib.
2261 Re-relocate ourselves with user-controlled symbol definitions.
2263 We must do this after TLS initialization in case after this
2264 re-relocation, we might call a user-supplied function
2265 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2267 #ifndef HP_TIMING_NONAVAIL
2268 hp_timing_t start;
2269 hp_timing_t stop;
2270 hp_timing_t add;
2271 #endif
2273 HP_TIMING_NOW (start);
2274 /* Mark the link map as not yet relocated again. */
2275 GL(dl_rtld_map).l_relocated = 0;
2276 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2277 HP_TIMING_NOW (stop);
2278 HP_TIMING_DIFF (add, start, stop);
2279 HP_TIMING_ACCUM_NT (relocate_time, add);
2282 #ifdef SHARED
2283 /* Auditing checkpoint: we have added all objects. */
2284 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2286 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2287 /* Do not call the functions for any auditing object. */
2288 if (head->l_auditing == 0)
2290 struct audit_ifaces *afct = GLRO(dl_audit);
2291 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2293 if (afct->activity != NULL)
2294 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2296 afct = afct->next;
2300 #endif
2302 /* Notify the debugger all new objects are now ready to go. We must re-get
2303 the address since by now the variable might be in another object. */
2304 r = _dl_debug_initialize (0, LM_ID_BASE);
2305 r->r_state = RT_CONSISTENT;
2306 _dl_debug_state ();
2308 #ifndef MAP_COPY
2309 /* We must munmap() the cache file. */
2310 _dl_unload_cache ();
2311 #endif
2313 /* Once we return, _dl_sysdep_start will invoke
2314 the DT_INIT functions and then *USER_ENTRY. */
2317 /* This is a little helper function for resolving symbols while
2318 tracing the binary. */
2319 static void
2320 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2321 const char *errstring)
2323 if (objname[0] == '\0')
2324 objname = rtld_progname ?: "<main program>";
2325 _dl_error_printf ("%s (%s)\n", errstring, objname);
2328 /* This is a little helper function for resolving symbols while
2329 tracing the binary. */
2330 static void
2331 print_missing_version (int errcode __attribute__ ((unused)),
2332 const char *objname, const char *errstring)
2334 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2335 objname, errstring);
2338 /* Nonzero if any of the debugging options is enabled. */
2339 static int any_debug attribute_relro;
2341 /* Process the string given as the parameter which explains which debugging
2342 options are enabled. */
2343 static void
2344 process_dl_debug (const char *dl_debug)
2346 /* When adding new entries make sure that the maximal length of a name
2347 is correctly handled in the LD_DEBUG_HELP code below. */
2348 static const struct
2350 unsigned char len;
2351 const char name[10];
2352 const char helptext[41];
2353 unsigned short int mask;
2354 } debopts[] =
2356 #define LEN_AND_STR(str) sizeof (str) - 1, str
2357 { LEN_AND_STR ("libs"), "display library search paths",
2358 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2359 { LEN_AND_STR ("reloc"), "display relocation processing",
2360 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2361 { LEN_AND_STR ("files"), "display progress for input file",
2362 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2363 { LEN_AND_STR ("symbols"), "display symbol table processing",
2364 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2365 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2366 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2367 { LEN_AND_STR ("versions"), "display version dependencies",
2368 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2369 { LEN_AND_STR ("all"), "all previous options combined",
2370 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2371 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2372 { LEN_AND_STR ("statistics"), "display relocation statistics",
2373 DL_DEBUG_STATISTICS },
2374 { LEN_AND_STR ("unused"), "determined unused DSOs",
2375 DL_DEBUG_UNUSED },
2376 { LEN_AND_STR ("help"), "display this help message and exit",
2377 DL_DEBUG_HELP },
2379 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2381 /* Skip separating white spaces and commas. */
2382 while (*dl_debug != '\0')
2384 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2386 size_t cnt;
2387 size_t len = 1;
2389 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2390 && dl_debug[len] != ',' && dl_debug[len] != ':')
2391 ++len;
2393 for (cnt = 0; cnt < ndebopts; ++cnt)
2394 if (debopts[cnt].len == len
2395 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2397 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2398 any_debug = 1;
2399 break;
2402 if (cnt == ndebopts)
2404 /* Display a warning and skip everything until next
2405 separator. */
2406 char *copy = strndupa (dl_debug, len);
2407 _dl_error_printf ("\
2408 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2411 dl_debug += len;
2412 continue;
2415 ++dl_debug;
2418 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2420 size_t cnt;
2422 _dl_printf ("\
2423 Valid options for the LD_DEBUG environment variable are:\n\n");
2425 for (cnt = 0; cnt < ndebopts; ++cnt)
2426 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2427 " " + debopts[cnt].len - 3,
2428 debopts[cnt].helptext);
2430 _dl_printf ("\n\
2431 To direct the debugging output into a file instead of standard output\n\
2432 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2433 _exit (0);
2437 static void
2438 process_dl_audit (char *str)
2440 /* The parameter is a colon separated list of DSO names. */
2441 char *p;
2443 while ((p = (strsep) (&str, ":")) != NULL)
2444 if (p[0] != '\0'
2445 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2446 || strchr (p, '/') == NULL))
2448 /* This is using the local malloc, not the system malloc. The
2449 memory can never be freed. */
2450 struct audit_list *newp = malloc (sizeof (*newp));
2451 newp->name = p;
2453 if (audit_list == NULL)
2454 audit_list = newp->next = newp;
2455 else
2457 newp->next = audit_list->next;
2458 audit_list = audit_list->next = newp;
2463 /* Process all environments variables the dynamic linker must recognize.
2464 Since all of them start with `LD_' we are a bit smarter while finding
2465 all the entries. */
2466 extern char **_environ attribute_hidden;
2469 static void
2470 process_envvars (enum mode *modep)
2472 char **runp = _environ;
2473 char *envline;
2474 enum mode mode = normal;
2475 char *debug_output = NULL;
2477 /* This is the default place for profiling data file. */
2478 GLRO(dl_profile_output)
2479 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2481 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2483 size_t len = 0;
2485 while (envline[len] != '\0' && envline[len] != '=')
2486 ++len;
2488 if (envline[len] != '=')
2489 /* This is a "LD_" variable at the end of the string without
2490 a '=' character. Ignore it since otherwise we will access
2491 invalid memory below. */
2492 continue;
2494 switch (len)
2496 case 4:
2497 /* Warning level, verbose or not. */
2498 if (memcmp (envline, "WARN", 4) == 0)
2499 GLRO(dl_verbose) = envline[5] != '\0';
2500 break;
2502 case 5:
2503 /* Debugging of the dynamic linker? */
2504 if (memcmp (envline, "DEBUG", 5) == 0)
2506 process_dl_debug (&envline[6]);
2507 break;
2509 if (memcmp (envline, "AUDIT", 5) == 0)
2510 process_dl_audit (&envline[6]);
2511 break;
2513 case 7:
2514 /* Print information about versions. */
2515 if (memcmp (envline, "VERBOSE", 7) == 0)
2517 version_info = envline[8] != '\0';
2518 break;
2521 /* List of objects to be preloaded. */
2522 if (memcmp (envline, "PRELOAD", 7) == 0)
2524 preloadlist = &envline[8];
2525 break;
2528 /* Which shared object shall be profiled. */
2529 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2530 GLRO(dl_profile) = &envline[8];
2531 break;
2533 case 8:
2534 /* Do we bind early? */
2535 if (memcmp (envline, "BIND_NOW", 8) == 0)
2537 GLRO(dl_lazy) = envline[9] == '\0';
2538 break;
2540 if (memcmp (envline, "BIND_NOT", 8) == 0)
2541 GLRO(dl_bind_not) = envline[9] != '\0';
2542 break;
2544 case 9:
2545 /* Test whether we want to see the content of the auxiliary
2546 array passed up from the kernel. */
2547 if (!INTUSE(__libc_enable_secure)
2548 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2549 _dl_show_auxv ();
2550 break;
2552 case 10:
2553 /* Mask for the important hardware capabilities. */
2554 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2555 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2556 0, 0);
2557 break;
2559 case 11:
2560 /* Path where the binary is found. */
2561 if (!INTUSE(__libc_enable_secure)
2562 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2563 GLRO(dl_origin_path) = &envline[12];
2564 break;
2566 case 12:
2567 /* The library search path. */
2568 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2570 library_path = &envline[13];
2571 break;
2574 /* Where to place the profiling data file. */
2575 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2577 debug_output = &envline[13];
2578 break;
2581 if (!INTUSE(__libc_enable_secure)
2582 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2583 GLRO(dl_dynamic_weak) = 1;
2584 break;
2586 case 13:
2587 /* We might have some extra environment variable with length 13
2588 to handle. */
2589 #ifdef EXTRA_LD_ENVVARS_13
2590 EXTRA_LD_ENVVARS_13
2591 #endif
2592 if (!INTUSE(__libc_enable_secure)
2593 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2595 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2596 break;
2599 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2600 GLRO(dl_pointer_guard) = envline[14] != '0';
2601 break;
2603 case 14:
2604 /* Where to place the profiling data file. */
2605 if (!INTUSE(__libc_enable_secure)
2606 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2607 && envline[15] != '\0')
2608 GLRO(dl_profile_output) = &envline[15];
2609 break;
2611 case 16:
2612 /* The mode of the dynamic linker can be set. */
2613 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2615 mode = trace;
2616 GLRO(dl_verbose) = 1;
2617 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2618 GLRO(dl_trace_prelink) = &envline[17];
2620 break;
2622 case 20:
2623 /* The mode of the dynamic linker can be set. */
2624 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2625 mode = trace;
2626 break;
2628 /* We might have some extra environment variable to handle. This
2629 is tricky due to the pre-processing of the length of the name
2630 in the switch statement here. The code here assumes that added
2631 environment variables have a different length. */
2632 #ifdef EXTRA_LD_ENVVARS
2633 EXTRA_LD_ENVVARS
2634 #endif
2638 /* The caller wants this information. */
2639 *modep = mode;
2641 /* Extra security for SUID binaries. Remove all dangerous environment
2642 variables. */
2643 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2645 static const char unsecure_envvars[] =
2646 #ifdef EXTRA_UNSECURE_ENVVARS
2647 EXTRA_UNSECURE_ENVVARS
2648 #endif
2649 UNSECURE_ENVVARS;
2650 const char *nextp;
2652 nextp = unsecure_envvars;
2655 unsetenv (nextp);
2656 /* We could use rawmemchr but this need not be fast. */
2657 nextp = (char *) (strchr) (nextp, '\0') + 1;
2659 while (*nextp != '\0');
2661 if (__access ("/etc/suid-debug", F_OK) != 0)
2663 unsetenv ("MALLOC_CHECK_");
2664 GLRO(dl_debug_mask) = 0;
2667 if (mode != normal)
2668 _exit (5);
2670 /* If we have to run the dynamic linker in debugging mode and the
2671 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2672 messages to this file. */
2673 else if (any_debug && debug_output != NULL)
2675 #ifdef O_NOFOLLOW
2676 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2677 #else
2678 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2679 #endif
2680 size_t name_len = strlen (debug_output);
2681 char buf[name_len + 12];
2682 char *startp;
2684 buf[name_len + 11] = '\0';
2685 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2686 *--startp = '.';
2687 startp = memcpy (startp - name_len, debug_output, name_len);
2689 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2690 if (GLRO(dl_debug_fd) == -1)
2691 /* We use standard output if opening the file failed. */
2692 GLRO(dl_debug_fd) = STDOUT_FILENO;
2697 /* Print the various times we collected. */
2698 static void
2699 __attribute ((noinline))
2700 print_statistics (hp_timing_t *rtld_total_timep)
2702 #ifndef HP_TIMING_NONAVAIL
2703 char buf[200];
2704 char *cp;
2705 char *wp;
2707 /* Total time rtld used. */
2708 if (HP_TIMING_AVAIL)
2710 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2711 _dl_debug_printf ("\nruntime linker statistics:\n"
2712 " total startup time in dynamic loader: %s\n", buf);
2714 /* Print relocation statistics. */
2715 char pbuf[30];
2716 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2717 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2718 pbuf + sizeof (pbuf), 10, 0);
2719 wp = pbuf;
2720 switch (pbuf + sizeof (pbuf) - cp)
2722 case 3:
2723 *wp++ = *cp++;
2724 case 2:
2725 *wp++ = *cp++;
2726 case 1:
2727 *wp++ = '.';
2728 *wp++ = *cp++;
2730 *wp = '\0';
2731 _dl_debug_printf ("\
2732 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2734 #endif
2736 unsigned long int num_relative_relocations = 0;
2737 for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
2739 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2740 continue;
2742 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2744 for (unsigned int i = 0; i < scope->r_nlist; i++)
2746 struct link_map *l = scope->r_list [i];
2748 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2749 num_relative_relocations
2750 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2751 #ifndef ELF_MACHINE_REL_RELATIVE
2752 /* Relative relocations are processed on these architectures if
2753 library is loaded to different address than p_vaddr or
2754 if not prelinked. */
2755 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2756 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2757 #else
2758 /* On e.g. IA-64 or Alpha, relative relocations are processed
2759 only if library is loaded to different address than p_vaddr. */
2760 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2761 #endif
2762 num_relative_relocations
2763 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2767 _dl_debug_printf (" number of relocations: %lu\n"
2768 " number of relocations from cache: %lu\n"
2769 " number of relative relocations: %lu\n",
2770 GL(dl_num_relocations),
2771 GL(dl_num_cache_relocations),
2772 num_relative_relocations);
2774 #ifndef HP_TIMING_NONAVAIL
2775 /* Time spend while loading the object and the dependencies. */
2776 if (HP_TIMING_AVAIL)
2778 char pbuf[30];
2779 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2780 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2781 pbuf + sizeof (pbuf), 10, 0);
2782 wp = pbuf;
2783 switch (pbuf + sizeof (pbuf) - cp)
2785 case 3:
2786 *wp++ = *cp++;
2787 case 2:
2788 *wp++ = *cp++;
2789 case 1:
2790 *wp++ = '.';
2791 *wp++ = *cp++;
2793 *wp = '\0';
2794 _dl_debug_printf ("\
2795 time needed to load objects: %s (%s%%)\n",
2796 buf, pbuf);
2798 #endif