* sysdeps/powerpc/powerpc64/setjmp-common.S: Make sure pointer guard
[glibc.git] / elf / rtld.c
blob76d129a0a035c3dab1145fbe4ba7e0263bec72e0
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h> /* Check if MAP_ANON is defined. */
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
44 #include <assert.h>
46 /* Avoid PLT use for our local calls at startup. */
47 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
49 /* GCC has mental blocks about _exit. */
50 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
51 #define _exit exit_internal
53 /* Helper function to handle errors while resolving symbols. */
54 static void print_unresolved (int errcode, const char *objname,
55 const char *errsting);
57 /* Helper function to handle errors when a version is missing. */
58 static void print_missing_version (int errcode, const char *objname,
59 const char *errsting);
61 /* Print the various times we collected. */
62 static void print_statistics (hp_timing_t *total_timep);
64 /* Add audit objects. */
65 static void process_dl_audit (char *str);
67 /* This is a list of all the modes the dynamic loader can be in. */
68 enum mode { normal, list, verify, trace };
70 /* Process all environments variables the dynamic linker must recognize.
71 Since all of them start with `LD_' we are a bit smarter while finding
72 all the entries. */
73 static void process_envvars (enum mode *modep);
75 #ifdef DL_ARGV_NOT_RELRO
76 int _dl_argc attribute_hidden;
77 char **_dl_argv = NULL;
78 /* Nonzero if we were run directly. */
79 unsigned int _dl_skip_args attribute_hidden;
80 #else
81 int _dl_argc attribute_relro attribute_hidden;
82 char **_dl_argv attribute_relro = NULL;
83 unsigned int _dl_skip_args attribute_relro attribute_hidden;
84 #endif
85 INTDEF(_dl_argv)
87 #ifndef THREAD_SET_STACK_GUARD
88 /* Only exported for architectures that don't store the stack guard canary
89 in thread local area. */
90 uintptr_t __stack_chk_guard attribute_relro;
91 #endif
93 /* Only exported for architectures that don't store the pointer guard
94 value in thread local area. */
95 uintptr_t __pointer_chk_guard_local
96 attribute_relro attribute_hidden __attribute__ ((nocommon));
97 #ifndef THREAD_SET_POINTER_GUARD
98 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
99 #endif
102 /* List of auditing DSOs. */
103 static struct audit_list
105 const char *name;
106 struct audit_list *next;
107 } *audit_list;
109 #ifndef HAVE_INLINED_SYSCALLS
110 /* Set nonzero during loading and initialization of executable and
111 libraries, cleared before the executable's entry point runs. This
112 must not be initialized to nonzero, because the unused dynamic
113 linker loaded in for libc.so's "ld.so.1" dep will provide the
114 definition seen by libc.so's initializer; that value must be zero,
115 and will be since that dynamic linker's _dl_start and dl_main will
116 never be called. */
117 int _dl_starting_up = 0;
118 INTVARDEF(_dl_starting_up)
119 #endif
121 /* This is the structure which defines all variables global to ld.so
122 (except those which cannot be added for some reason). */
123 struct rtld_global _rtld_global =
125 /* Default presumption without further information is executable stack. */
126 ._dl_stack_flags = PF_R|PF_W|PF_X,
127 #ifdef _LIBC_REENTRANT
128 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER
129 #endif
131 /* If we would use strong_alias here the compiler would see a
132 non-hidden definition. This would undo the effect of the previous
133 declaration. So spell out was strong_alias does plus add the
134 visibility attribute. */
135 extern struct rtld_global _rtld_local
136 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
139 /* This variable is similar to _rtld_local, but all values are
140 read-only after relocation. */
141 struct rtld_global_ro _rtld_global_ro attribute_relro =
143 /* Get architecture specific initializer. */
144 #include <dl-procinfo.c>
145 #ifdef NEED_DL_SYSINFO
146 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
147 #endif
148 ._dl_debug_fd = STDERR_FILENO,
149 ._dl_use_load_bias = -2,
150 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
151 ._dl_hwcap_mask = HWCAP_IMPORTANT,
152 ._dl_lazy = 1,
153 ._dl_fpu_control = _FPU_DEFAULT,
154 ._dl_pointer_guard = 1,
156 /* Function pointers. */
157 ._dl_debug_printf = _dl_debug_printf,
158 ._dl_catch_error = _dl_catch_error,
159 ._dl_signal_error = _dl_signal_error,
160 ._dl_mcount = _dl_mcount_internal,
161 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
162 ._dl_check_caller = _dl_check_caller,
163 ._dl_open = _dl_open,
164 ._dl_close = _dl_close
166 /* If we would use strong_alias here the compiler would see a
167 non-hidden definition. This would undo the effect of the previous
168 declaration. So spell out was strong_alias does plus add the
169 visibility attribute. */
170 extern struct rtld_global_ro _rtld_local_ro
171 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
174 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
175 ElfW(Addr) *user_entry);
177 /* These two variables cannot be moved into .data.rel.ro. */
178 static struct libname_list _dl_rtld_libname;
179 static struct libname_list _dl_rtld_libname2;
181 /* We expect less than a second for relocation. */
182 #ifdef HP_SMALL_TIMING_AVAIL
183 # undef HP_TIMING_AVAIL
184 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
185 #endif
187 /* Variable for statistics. */
188 #ifndef HP_TIMING_NONAVAIL
189 static hp_timing_t relocate_time;
190 static hp_timing_t load_time attribute_relro;
191 static hp_timing_t start_time attribute_relro;
192 #endif
194 /* Additional definitions needed by TLS initialization. */
195 #ifdef TLS_INIT_HELPER
196 TLS_INIT_HELPER
197 #endif
199 /* Helper function for syscall implementation. */
200 #ifdef DL_SYSINFO_IMPLEMENTATION
201 DL_SYSINFO_IMPLEMENTATION
202 #endif
204 /* Before ld.so is relocated we must not access variables which need
205 relocations. This means variables which are exported. Variables
206 declared as static are fine. If we can mark a variable hidden this
207 is fine, too. The latter is important here. We can avoid setting
208 up a temporary link map for ld.so if we can mark _rtld_global as
209 hidden. */
210 #if defined PI_STATIC_AND_HIDDEN && defined HAVE_HIDDEN \
211 && defined HAVE_VISIBILITY_ATTRIBUTE
212 # define DONT_USE_BOOTSTRAP_MAP 1
213 #endif
215 #ifdef DONT_USE_BOOTSTRAP_MAP
216 static ElfW(Addr) _dl_start_final (void *arg);
217 #else
218 struct dl_start_final_info
220 struct link_map l;
221 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
222 hp_timing_t start_time;
223 #endif
225 static ElfW(Addr) _dl_start_final (void *arg,
226 struct dl_start_final_info *info);
227 #endif
229 /* These defined magically in the linker script. */
230 extern char _begin[] attribute_hidden;
231 extern char _etext[] attribute_hidden;
232 extern char _end[] attribute_hidden;
235 #ifdef RTLD_START
236 RTLD_START
237 #else
238 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
239 #endif
241 #ifndef VALIDX
242 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
243 + DT_EXTRANUM + DT_VALTAGIDX (tag))
244 #endif
245 #ifndef ADDRIDX
246 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
247 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
248 #endif
250 /* This is the second half of _dl_start (below). It can be inlined safely
251 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
252 references. When the tools don't permit us to avoid using a GOT entry
253 for _dl_rtld_global (no attribute_hidden support), we must make sure
254 this function is not inlined (see below). */
256 #ifdef DONT_USE_BOOTSTRAP_MAP
257 static inline ElfW(Addr) __attribute__ ((always_inline))
258 _dl_start_final (void *arg)
259 #else
260 static ElfW(Addr) __attribute__ ((noinline))
261 _dl_start_final (void *arg, struct dl_start_final_info *info)
262 #endif
264 ElfW(Addr) start_addr;
266 if (HP_TIMING_AVAIL)
268 /* If it hasn't happen yet record the startup time. */
269 if (! HP_TIMING_INLINE)
270 HP_TIMING_NOW (start_time);
271 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
272 else
273 start_time = info->start_time;
274 #endif
276 /* Initialize the timing functions. */
277 HP_TIMING_DIFF_INIT ();
280 /* Transfer data about ourselves to the permanent link_map structure. */
281 #ifndef DONT_USE_BOOTSTRAP_MAP
282 GL(dl_rtld_map).l_addr = info->l.l_addr;
283 GL(dl_rtld_map).l_ld = info->l.l_ld;
284 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
285 sizeof GL(dl_rtld_map).l_info);
286 GL(dl_rtld_map).l_mach = info->l.l_mach;
287 GL(dl_rtld_map).l_relocated = 1;
288 #endif
289 _dl_setup_hash (&GL(dl_rtld_map));
290 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
291 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
292 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
293 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
294 /* Copy the TLS related data if necessary. */
295 #if USE_TLS && !defined DONT_USE_BOOTSTRAP_MAP
296 # if USE___THREAD
297 assert (info->l.l_tls_modid != 0);
298 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
299 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
300 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
301 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
302 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
303 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
304 GL(dl_rtld_map).l_tls_modid = 1;
305 # else
306 assert (info->l.l_tls_modid == 0);
307 # if NO_TLS_OFFSET != 0
308 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
309 # endif
310 # endif
312 #endif
314 #if HP_TIMING_AVAIL
315 HP_TIMING_NOW (GL(dl_cpuclock_offset));
316 #endif
318 /* Initialize the stack end variable. */
319 __libc_stack_end = __builtin_frame_address (0);
321 /* Call the OS-dependent function to set up life so we can do things like
322 file access. It will call `dl_main' (below) to do all the real work
323 of the dynamic linker, and then unwind our frame and run the user
324 entry point on the same stack we entered on. */
325 start_addr = _dl_sysdep_start (arg, &dl_main);
327 #ifndef HP_TIMING_NONAVAIL
328 hp_timing_t rtld_total_time;
329 if (HP_TIMING_AVAIL)
331 hp_timing_t end_time;
333 /* Get the current time. */
334 HP_TIMING_NOW (end_time);
336 /* Compute the difference. */
337 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
339 #endif
341 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
343 #ifndef HP_TIMING_NONAVAIL
344 print_statistics (&rtld_total_time);
345 #else
346 print_statistics (NULL);
347 #endif
350 return start_addr;
353 static ElfW(Addr) __attribute_used__ internal_function
354 _dl_start (void *arg)
356 #ifdef DONT_USE_BOOTSTRAP_MAP
357 # define bootstrap_map GL(dl_rtld_map)
358 #else
359 struct dl_start_final_info info;
360 # define bootstrap_map info.l
361 #endif
363 /* This #define produces dynamic linking inline functions for
364 bootstrap relocation instead of general-purpose relocation. */
365 #define RTLD_BOOTSTRAP
366 #define RESOLVE_MAP(sym, version, flags) \
367 ((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map)
368 #include "dynamic-link.h"
370 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
371 #ifdef DONT_USE_BOOTSTRAP_MAP
372 HP_TIMING_NOW (start_time);
373 #else
374 HP_TIMING_NOW (info.start_time);
375 #endif
377 /* Partly clean the `bootstrap_map' structure up. Don't use
378 `memset' since it might not be built in or inlined and we cannot
379 make function calls at this point. Use '__builtin_memset' if we
380 know it is available. We do not have to clear the memory if we
381 do not have to use the temporary bootstrap_map. Global variables
382 are initialized to zero by default. */
383 #ifndef DONT_USE_BOOTSTRAP_MAP
384 # ifdef HAVE_BUILTIN_MEMSET
385 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
386 # else
387 for (size_t cnt = 0;
388 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
389 ++cnt)
390 bootstrap_map.l_info[cnt] = 0;
391 # endif
392 #endif
394 /* Figure out the run-time load address of the dynamic linker itself. */
395 bootstrap_map.l_addr = elf_machine_load_address ();
397 /* Read our own dynamic section and fill in the info array. */
398 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
399 elf_get_dynamic_info (&bootstrap_map, NULL);
401 #if defined USE_TLS && NO_TLS_OFFSET != 0
402 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
403 #endif
405 /* Get the dynamic linker's own program header. First we need the ELF
406 file header. The `_begin' symbol created by the linker script points
407 to it. When we have something like GOTOFF relocs, we can use a plain
408 reference to find the runtime address. Without that, we have to rely
409 on the `l_addr' value, which is not the value we want when prelinked. */
410 #if USE___THREAD
411 dtv_t initdtv[3];
412 ElfW(Ehdr) *ehdr
413 # ifdef DONT_USE_BOOTSTRAP_MAP
414 = (ElfW(Ehdr) *) &_begin;
415 # else
416 # error This will not work with prelink.
417 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
418 # endif
419 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
420 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
421 while (cnt-- > 0)
422 if (phdr[cnt].p_type == PT_TLS)
424 void *tlsblock;
425 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
426 char *p;
428 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
429 bootstrap_map.l_tls_align = phdr[cnt].p_align;
430 if (phdr[cnt].p_align == 0)
431 bootstrap_map.l_tls_firstbyte_offset = 0;
432 else
433 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
434 & (phdr[cnt].p_align - 1));
435 assert (bootstrap_map.l_tls_blocksize != 0);
436 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
437 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
438 + phdr[cnt].p_vaddr);
440 /* We can now allocate the initial TLS block. This can happen
441 on the stack. We'll get the final memory later when we
442 know all about the various objects loaded at startup
443 time. */
444 # if TLS_TCB_AT_TP
445 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
446 TLS_INIT_TCB_ALIGN)
447 + TLS_INIT_TCB_SIZE
448 + max_align);
449 # elif TLS_DTV_AT_TP
450 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
451 bootstrap_map.l_tls_align)
452 + bootstrap_map.l_tls_blocksize
453 + max_align);
454 # else
455 /* In case a model with a different layout for the TCB and DTV
456 is defined add another #elif here and in the following #ifs. */
457 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
458 # endif
459 /* Align the TLS block. */
460 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
461 & ~(max_align - 1));
463 /* Initialize the dtv. [0] is the length, [1] the generation
464 counter. */
465 initdtv[0].counter = 1;
466 initdtv[1].counter = 0;
468 /* Initialize the TLS block. */
469 # if TLS_TCB_AT_TP
470 initdtv[2].pointer = tlsblock;
471 # elif TLS_DTV_AT_TP
472 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
473 bootstrap_map.l_tls_align);
474 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
475 # else
476 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
477 # endif
478 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
479 bootstrap_map.l_tls_initimage_size);
480 # ifdef HAVE_BUILTIN_MEMSET
481 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
482 - bootstrap_map.l_tls_initimage_size));
483 # else
485 size_t remaining = (bootstrap_map.l_tls_blocksize
486 - bootstrap_map.l_tls_initimage_size);
487 while (remaining-- > 0)
488 *p++ = '\0';
490 # endif
492 /* Install the pointer to the dtv. */
494 /* Initialize the thread pointer. */
495 # if TLS_TCB_AT_TP
496 bootstrap_map.l_tls_offset
497 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
499 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
500 initdtv);
502 const char *lossage = TLS_INIT_TP ((char *) tlsblock
503 + bootstrap_map.l_tls_offset, 0);
504 # elif TLS_DTV_AT_TP
505 INSTALL_DTV (tlsblock, initdtv);
506 const char *lossage = TLS_INIT_TP (tlsblock, 0);
507 # else
508 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
509 # endif
510 if (__builtin_expect (lossage != NULL, 0))
511 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
512 lossage);
514 /* So far this is module number one. */
515 bootstrap_map.l_tls_modid = 1;
517 /* There can only be one PT_TLS entry. */
518 break;
520 #endif /* USE___THREAD */
522 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
523 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
524 #endif
526 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
528 /* Relocate ourselves so we can do normal function calls and
529 data access using the global offset table. */
531 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
533 bootstrap_map.l_relocated = 1;
535 /* Please note that we don't allow profiling of this object and
536 therefore need not test whether we have to allocate the array
537 for the relocation results (as done in dl-reloc.c). */
539 /* Now life is sane; we can call functions and access global data.
540 Set up to use the operating system facilities, and find out from
541 the operating system's program loader where to find the program
542 header table in core. Put the rest of _dl_start into a separate
543 function, that way the compiler cannot put accesses to the GOT
544 before ELF_DYNAMIC_RELOCATE. */
546 #ifdef DONT_USE_BOOTSTRAP_MAP
547 ElfW(Addr) entry = _dl_start_final (arg);
548 #else
549 ElfW(Addr) entry = _dl_start_final (arg, &info);
550 #endif
552 #ifndef ELF_MACHINE_START_ADDRESS
553 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
554 #endif
556 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
562 /* Now life is peachy; we can do all normal operations.
563 On to the real work. */
565 /* Some helper functions. */
567 /* Arguments to relocate_doit. */
568 struct relocate_args
570 struct link_map *l;
571 int lazy;
574 struct map_args
576 /* Argument to map_doit. */
577 char *str;
578 struct link_map *loader;
579 int is_preloaded;
580 int mode;
581 /* Return value of map_doit. */
582 struct link_map *map;
585 struct dlmopen_args
587 const char *fname;
588 struct link_map *map;
591 struct lookup_args
593 const char *name;
594 struct link_map *map;
595 void *result;
598 /* Arguments to version_check_doit. */
599 struct version_check_args
601 int doexit;
602 int dotrace;
605 static void
606 relocate_doit (void *a)
608 struct relocate_args *args = (struct relocate_args *) a;
610 _dl_relocate_object (args->l, args->l->l_scope, args->lazy, 0);
613 static void
614 map_doit (void *a)
616 struct map_args *args = (struct map_args *) a;
617 args->map = _dl_map_object (args->loader, args->str,
618 args->is_preloaded, lt_library, 0, args->mode,
619 LM_ID_BASE);
622 static void
623 dlmopen_doit (void *a)
625 struct dlmopen_args *args = (struct dlmopen_args *) a;
626 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
627 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
628 __environ);
631 static void
632 lookup_doit (void *a)
634 struct lookup_args *args = (struct lookup_args *) a;
635 const ElfW(Sym) *ref = NULL;
636 args->result = NULL;
637 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
638 args->map->l_local_scope, NULL, 0,
639 DL_LOOKUP_RETURN_NEWEST, NULL);
640 if (ref != NULL)
641 args->result = DL_SYMBOL_ADDRESS (l, ref);
644 static void
645 version_check_doit (void *a)
647 struct version_check_args *args = (struct version_check_args *) a;
648 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
649 args->dotrace) && args->doexit)
650 /* We cannot start the application. Abort now. */
651 _exit (1);
655 static inline struct link_map *
656 find_needed (const char *name)
658 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
659 unsigned int n = scope->r_nlist;
661 while (n-- > 0)
662 if (_dl_name_match_p (name, scope->r_list[n]))
663 return scope->r_list[n];
665 /* Should never happen. */
666 return NULL;
669 static int
670 match_version (const char *string, struct link_map *map)
672 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
673 ElfW(Verdef) *def;
675 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
676 if (map->l_info[VERDEFTAG] == NULL)
677 /* The file has no symbol versioning. */
678 return 0;
680 def = (ElfW(Verdef) *) ((char *) map->l_addr
681 + map->l_info[VERDEFTAG]->d_un.d_ptr);
682 while (1)
684 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
686 /* Compare the version strings. */
687 if (strcmp (string, strtab + aux->vda_name) == 0)
688 /* Bingo! */
689 return 1;
691 /* If no more definitions we failed to find what we want. */
692 if (def->vd_next == 0)
693 break;
695 /* Next definition. */
696 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
699 return 0;
702 #ifdef USE_TLS
703 static bool tls_init_tp_called;
705 static void *
706 init_tls (void)
708 /* Number of elements in the static TLS block. */
709 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
711 /* Do not do this twice. The audit interface might have required
712 the DTV interfaces to be set up early. */
713 if (GL(dl_initial_dtv) != NULL)
714 return NULL;
716 /* Allocate the array which contains the information about the
717 dtv slots. We allocate a few entries more than needed to
718 avoid the need for reallocation. */
719 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
721 /* Allocate. */
722 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
723 calloc (sizeof (struct dtv_slotinfo_list)
724 + nelem * sizeof (struct dtv_slotinfo), 1);
725 /* No need to check the return value. If memory allocation failed
726 the program would have been terminated. */
728 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
729 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
730 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
732 /* Fill in the information from the loaded modules. No namespace
733 but the base one can be filled at this time. */
734 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
735 int i = 0;
736 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
737 l = l->l_next)
738 if (l->l_tls_blocksize != 0)
740 /* This is a module with TLS data. Store the map reference.
741 The generation counter is zero. */
742 slotinfo[i].map = l;
743 /* slotinfo[i].gen = 0; */
744 ++i;
746 assert (i == GL(dl_tls_max_dtv_idx));
748 /* Compute the TLS offsets for the various blocks. */
749 _dl_determine_tlsoffset ();
751 /* Construct the static TLS block and the dtv for the initial
752 thread. For some platforms this will include allocating memory
753 for the thread descriptor. The memory for the TLS block will
754 never be freed. It should be allocated accordingly. The dtv
755 array can be changed if dynamic loading requires it. */
756 void *tcbp = _dl_allocate_tls_storage ();
757 if (tcbp == NULL)
758 _dl_fatal_printf ("\
759 cannot allocate TLS data structures for initial thread");
761 /* Store for detection of the special case by __tls_get_addr
762 so it knows not to pass this dtv to the normal realloc. */
763 GL(dl_initial_dtv) = GET_DTV (tcbp);
765 /* And finally install it for the main thread. If ld.so itself uses
766 TLS we know the thread pointer was initialized earlier. */
767 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
768 if (__builtin_expect (lossage != NULL, 0))
769 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
770 tls_init_tp_called = true;
772 return tcbp;
774 #endif
776 #ifdef _LIBC_REENTRANT
777 /* _dl_error_catch_tsd points to this for the single-threaded case.
778 It's reset by the thread library for multithreaded programs. */
779 void ** __attribute__ ((const))
780 _dl_initial_error_catch_tsd (void)
782 static void *data;
783 return &data;
785 #endif
788 static unsigned int
789 do_preload (char *fname, struct link_map *main_map, const char *where)
791 const char *objname;
792 const char *err_str = NULL;
793 struct map_args args;
794 bool malloced;
796 args.str = fname;
797 args.loader = main_map;
798 args.is_preloaded = 1;
799 args.mode = 0;
801 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
803 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
804 if (__builtin_expect (err_str != NULL, 0))
806 _dl_error_printf ("\
807 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
808 fname, where);
809 /* No need to call free, this is still before
810 the libc's malloc is used. */
812 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
813 /* It is no duplicate. */
814 return 1;
816 /* Nothing loaded. */
817 return 0;
820 #if defined SHARED && defined _LIBC_REENTRANT \
821 && defined __rtld_lock_default_lock_recursive
822 static void
823 rtld_lock_default_lock_recursive (void *lock)
825 __rtld_lock_default_lock_recursive (lock);
828 static void
829 rtld_lock_default_unlock_recursive (void *lock)
831 __rtld_lock_default_unlock_recursive (lock);
833 #endif
836 /* The library search path. */
837 static const char *library_path attribute_relro;
838 /* The list preloaded objects. */
839 static const char *preloadlist attribute_relro;
840 /* Nonzero if information about versions has to be printed. */
841 static int version_info attribute_relro;
843 static void
844 dl_main (const ElfW(Phdr) *phdr,
845 ElfW(Word) phnum,
846 ElfW(Addr) *user_entry)
848 const ElfW(Phdr) *ph;
849 enum mode mode;
850 struct link_map *main_map;
851 size_t file_size;
852 char *file;
853 bool has_interp = false;
854 unsigned int i;
855 bool prelinked = false;
856 bool rtld_is_main = false;
857 #ifndef HP_TIMING_NONAVAIL
858 hp_timing_t start;
859 hp_timing_t stop;
860 hp_timing_t diff;
861 #endif
862 #ifdef USE_TLS
863 void *tcbp = NULL;
864 #endif
866 #ifdef _LIBC_REENTRANT
867 /* Explicit initialization since the reloc would just be more work. */
868 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
869 #endif
871 #ifdef USE_TLS
872 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
873 #endif
875 #if defined SHARED && defined _LIBC_REENTRANT \
876 && defined __rtld_lock_default_lock_recursive
877 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
878 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
879 #endif
881 /* The explicit initialization here is cheaper than processing the reloc
882 in the _rtld_local definition's initializer. */
883 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
885 /* Process the environment variable which control the behaviour. */
886 process_envvars (&mode);
888 #ifndef HAVE_INLINED_SYSCALLS
889 /* Set up a flag which tells we are just starting. */
890 INTUSE(_dl_starting_up) = 1;
891 #endif
893 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
895 /* Ho ho. We are not the program interpreter! We are the program
896 itself! This means someone ran ld.so as a command. Well, that
897 might be convenient to do sometimes. We support it by
898 interpreting the args like this:
900 ld.so PROGRAM ARGS...
902 The first argument is the name of a file containing an ELF
903 executable we will load and run with the following arguments.
904 To simplify life here, PROGRAM is searched for using the
905 normal rules for shared objects, rather than $PATH or anything
906 like that. We just load it and use its entry point; we don't
907 pay attention to its PT_INTERP command (we are the interpreter
908 ourselves). This is an easy way to test a new ld.so before
909 installing it. */
910 rtld_is_main = true;
912 /* Note the place where the dynamic linker actually came from. */
913 GL(dl_rtld_map).l_name = rtld_progname;
915 while (_dl_argc > 1)
916 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
918 mode = list;
919 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
921 ++_dl_skip_args;
922 --_dl_argc;
923 ++INTUSE(_dl_argv);
925 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
927 mode = verify;
929 ++_dl_skip_args;
930 --_dl_argc;
931 ++INTUSE(_dl_argv);
933 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
934 && _dl_argc > 2)
936 library_path = INTUSE(_dl_argv)[2];
938 _dl_skip_args += 2;
939 _dl_argc -= 2;
940 INTUSE(_dl_argv) += 2;
942 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
943 && _dl_argc > 2)
945 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
947 _dl_skip_args += 2;
948 _dl_argc -= 2;
949 INTUSE(_dl_argv) += 2;
951 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
953 process_dl_audit (INTUSE(_dl_argv)[2]);
955 _dl_skip_args += 2;
956 _dl_argc -= 2;
957 INTUSE(_dl_argv) += 2;
959 else
960 break;
962 /* If we have no further argument the program was called incorrectly.
963 Grant the user some education. */
964 if (_dl_argc < 2)
965 _dl_fatal_printf ("\
966 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
967 You have invoked `ld.so', the helper program for shared library executables.\n\
968 This program usually lives in the file `/lib/ld.so', and special directives\n\
969 in executable files using ELF shared libraries tell the system's program\n\
970 loader to load the helper program from this file. This helper program loads\n\
971 the shared libraries needed by the program executable, prepares the program\n\
972 to run, and runs it. You may invoke this helper program directly from the\n\
973 command line to load and run an ELF executable file; this is like executing\n\
974 that file itself, but always uses this helper program from the file you\n\
975 specified, instead of the helper program file specified in the executable\n\
976 file you run. This is mostly of use for maintainers to test new versions\n\
977 of this helper program; chances are you did not intend to run this program.\n\
979 --list list all dependencies and how they are resolved\n\
980 --verify verify that given object really is a dynamically linked\n\
981 object we can handle\n\
982 --library-path PATH use given PATH instead of content of the environment\n\
983 variable LD_LIBRARY_PATH\n\
984 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
985 in LIST\n");
987 ++_dl_skip_args;
988 --_dl_argc;
989 ++INTUSE(_dl_argv);
991 /* The initialization of _dl_stack_flags done below assumes the
992 executable's PT_GNU_STACK may have been honored by the kernel, and
993 so a PT_GNU_STACK with PF_X set means the stack started out with
994 execute permission. However, this is not really true if the
995 dynamic linker is the executable the kernel loaded. For this
996 case, we must reinitialize _dl_stack_flags to match the dynamic
997 linker itself. If the dynamic linker was built with a
998 PT_GNU_STACK, then the kernel may have loaded us with a
999 nonexecutable stack that we will have to make executable when we
1000 load the program below unless it has a PT_GNU_STACK indicating
1001 nonexecutable stack is ok. */
1003 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1004 if (ph->p_type == PT_GNU_STACK)
1006 GL(dl_stack_flags) = ph->p_flags;
1007 break;
1010 if (__builtin_expect (mode, normal) == verify)
1012 const char *objname;
1013 const char *err_str = NULL;
1014 struct map_args args;
1015 bool malloced;
1017 args.str = rtld_progname;
1018 args.loader = NULL;
1019 args.is_preloaded = 0;
1020 args.mode = __RTLD_OPENEXEC;
1021 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1022 &args);
1023 if (__builtin_expect (err_str != NULL, 0))
1024 /* We don't free the returned string, the programs stops
1025 anyway. */
1026 _exit (EXIT_FAILURE);
1028 else
1030 HP_TIMING_NOW (start);
1031 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1032 __RTLD_OPENEXEC, LM_ID_BASE);
1033 HP_TIMING_NOW (stop);
1035 HP_TIMING_DIFF (load_time, start, stop);
1038 /* Now the map for the main executable is available. */
1039 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1041 phdr = main_map->l_phdr;
1042 phnum = main_map->l_phnum;
1043 /* We overwrite here a pointer to a malloc()ed string. But since
1044 the malloc() implementation used at this point is the dummy
1045 implementations which has no real free() function it does not
1046 makes sense to free the old string first. */
1047 main_map->l_name = (char *) "";
1048 *user_entry = main_map->l_entry;
1050 else
1052 /* Create a link_map for the executable itself.
1053 This will be what dlopen on "" returns. */
1054 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1055 __RTLD_OPENEXEC, LM_ID_BASE);
1056 assert (main_map != NULL);
1057 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1058 main_map->l_phdr = phdr;
1059 main_map->l_phnum = phnum;
1060 main_map->l_entry = *user_entry;
1062 /* At this point we are in a bit of trouble. We would have to
1063 fill in the values for l_dev and l_ino. But in general we
1064 do not know where the file is. We also do not handle AT_EXECFD
1065 even if it would be passed up.
1067 We leave the values here defined to 0. This is normally no
1068 problem as the program code itself is normally no shared
1069 object and therefore cannot be loaded dynamically. Nothing
1070 prevent the use of dynamic binaries and in these situations
1071 we might get problems. We might not be able to find out
1072 whether the object is already loaded. But since there is no
1073 easy way out and because the dynamic binary must also not
1074 have an SONAME we ignore this program for now. If it becomes
1075 a problem we can force people using SONAMEs. */
1077 /* We delay initializing the path structure until we got the dynamic
1078 information for the program. */
1081 main_map->l_map_end = 0;
1082 main_map->l_text_end = 0;
1083 /* Perhaps the executable has no PT_LOAD header entries at all. */
1084 main_map->l_map_start = ~0;
1085 /* And it was opened directly. */
1086 ++main_map->l_direct_opencount;
1088 /* Scan the program header table for the dynamic section. */
1089 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1090 switch (ph->p_type)
1092 case PT_PHDR:
1093 /* Find out the load address. */
1094 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1095 break;
1096 case PT_DYNAMIC:
1097 /* This tells us where to find the dynamic section,
1098 which tells us everything we need to do. */
1099 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1100 break;
1101 case PT_INTERP:
1102 /* This "interpreter segment" was used by the program loader to
1103 find the program interpreter, which is this program itself, the
1104 dynamic linker. We note what name finds us, so that a future
1105 dlopen call or DT_NEEDED entry, for something that wants to link
1106 against the dynamic linker as a shared library, will know that
1107 the shared object is already loaded. */
1108 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1109 + ph->p_vaddr);
1110 /* _dl_rtld_libname.next = NULL; Already zero. */
1111 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1113 /* Ordinarilly, we would get additional names for the loader from
1114 our DT_SONAME. This can't happen if we were actually linked as
1115 a static executable (detect this case when we have no DYNAMIC).
1116 If so, assume the filename component of the interpreter path to
1117 be our SONAME, and add it to our name list. */
1118 if (GL(dl_rtld_map).l_ld == NULL)
1120 const char *p = NULL;
1121 const char *cp = _dl_rtld_libname.name;
1123 /* Find the filename part of the path. */
1124 while (*cp != '\0')
1125 if (*cp++ == '/')
1126 p = cp;
1128 if (p != NULL)
1130 _dl_rtld_libname2.name = p;
1131 /* _dl_rtld_libname2.next = NULL; Already zero. */
1132 _dl_rtld_libname.next = &_dl_rtld_libname2;
1136 has_interp = true;
1137 break;
1138 case PT_LOAD:
1140 ElfW(Addr) mapstart;
1141 ElfW(Addr) allocend;
1143 /* Remember where the main program starts in memory. */
1144 mapstart = (main_map->l_addr + (ph->p_vaddr & ~(ph->p_align - 1)));
1145 if (main_map->l_map_start > mapstart)
1146 main_map->l_map_start = mapstart;
1148 /* Also where it ends. */
1149 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1150 if (main_map->l_map_end < allocend)
1151 main_map->l_map_end = allocend;
1152 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1153 main_map->l_text_end = allocend;
1155 break;
1157 case PT_TLS:
1158 #ifdef USE_TLS
1159 if (ph->p_memsz > 0)
1161 /* Note that in the case the dynamic linker we duplicate work
1162 here since we read the PT_TLS entry already in
1163 _dl_start_final. But the result is repeatable so do not
1164 check for this special but unimportant case. */
1165 main_map->l_tls_blocksize = ph->p_memsz;
1166 main_map->l_tls_align = ph->p_align;
1167 if (ph->p_align == 0)
1168 main_map->l_tls_firstbyte_offset = 0;
1169 else
1170 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1171 & (ph->p_align - 1));
1172 main_map->l_tls_initimage_size = ph->p_filesz;
1173 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1175 /* This image gets the ID one. */
1176 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1178 #else
1179 _dl_fatal_printf ("\
1180 ld.so does not support TLS, but program uses it!\n");
1181 #endif
1182 break;
1184 case PT_GNU_STACK:
1185 GL(dl_stack_flags) = ph->p_flags;
1186 break;
1188 case PT_GNU_RELRO:
1189 main_map->l_relro_addr = ph->p_vaddr;
1190 main_map->l_relro_size = ph->p_memsz;
1191 break;
1193 #ifdef USE_TLS
1194 /* Adjust the address of the TLS initialization image in case
1195 the executable is actually an ET_DYN object. */
1196 if (main_map->l_tls_initimage != NULL)
1197 main_map->l_tls_initimage
1198 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1199 #endif
1200 if (! main_map->l_map_end)
1201 main_map->l_map_end = ~0;
1202 if (! main_map->l_text_end)
1203 main_map->l_text_end = ~0;
1204 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1206 /* We were invoked directly, so the program might not have a
1207 PT_INTERP. */
1208 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1209 /* _dl_rtld_libname.next = NULL; Already zero. */
1210 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1212 else
1213 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1215 /* If the current libname is different from the SONAME, add the
1216 latter as well. */
1217 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1218 && strcmp (GL(dl_rtld_map).l_libname->name,
1219 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1220 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1222 static struct libname_list newname;
1223 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1224 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1225 newname.next = NULL;
1226 newname.dont_free = 1;
1228 assert (GL(dl_rtld_map).l_libname->next == NULL);
1229 GL(dl_rtld_map).l_libname->next = &newname;
1231 /* The ld.so must be relocated since otherwise loading audit modules
1232 will fail since they reuse the very same ld.so. */
1233 assert (GL(dl_rtld_map).l_relocated);
1235 if (! rtld_is_main)
1237 /* Extract the contents of the dynamic section for easy access. */
1238 elf_get_dynamic_info (main_map, NULL);
1239 /* Set up our cache of pointers into the hash table. */
1240 _dl_setup_hash (main_map);
1243 if (__builtin_expect (mode, normal) == verify)
1245 /* We were called just to verify that this is a dynamic
1246 executable using us as the program interpreter. Exit with an
1247 error if we were not able to load the binary or no interpreter
1248 is specified (i.e., this is no dynamically linked binary. */
1249 if (main_map->l_ld == NULL)
1250 _exit (1);
1252 /* We allow here some platform specific code. */
1253 #ifdef DISTINGUISH_LIB_VERSIONS
1254 DISTINGUISH_LIB_VERSIONS;
1255 #endif
1256 _exit (has_interp ? 0 : 2);
1259 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1260 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1261 /* Set up the data structures for the system-supplied DSO early,
1262 so they can influence _dl_init_paths. */
1263 if (GLRO(dl_sysinfo_dso) != NULL)
1265 /* Do an abridged version of the work _dl_map_object_from_fd would do
1266 to map in the object. It's already mapped and prelinked (and
1267 better be, since it's read-only and so we couldn't relocate it).
1268 We just want our data structures to describe it as if we had just
1269 mapped and relocated it normally. */
1270 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1271 0, LM_ID_BASE);
1272 if (__builtin_expect (l != NULL, 1))
1274 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1276 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1277 + GLRO(dl_sysinfo_dso)->e_phoff);
1278 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1279 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1281 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1282 if (ph->p_type == PT_DYNAMIC)
1284 l->l_ld = (void *) ph->p_vaddr;
1285 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1287 else if (ph->p_type == PT_LOAD)
1289 if (! l->l_addr)
1290 l->l_addr = ph->p_vaddr;
1291 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1292 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1293 if ((ph->p_flags & PF_X)
1294 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1295 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1297 else
1298 /* There must be no TLS segment. */
1299 assert (ph->p_type != PT_TLS);
1301 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1302 l->l_addr = l->l_map_start - l->l_addr;
1303 l->l_map_end += l->l_addr;
1304 l->l_text_end += l->l_addr;
1305 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1306 elf_get_dynamic_info (l, dyn_temp);
1307 _dl_setup_hash (l);
1308 l->l_relocated = 1;
1310 /* Initialize l_local_scope to contain just this map. This allows
1311 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1312 So we create a single entry list pointing to l_real as its only
1313 element */
1314 l->l_local_scope[0]->r_nlist = 1;
1315 l->l_local_scope[0]->r_list = &l->l_real;
1317 /* Now that we have the info handy, use the DSO image's soname
1318 so this object can be looked up by name. Note that we do not
1319 set l_name here. That field gives the file name of the DSO,
1320 and this DSO is not associated with any file. */
1321 if (l->l_info[DT_SONAME] != NULL)
1323 /* Work around a kernel problem. The kernel cannot handle
1324 addresses in the vsyscall DSO pages in writev() calls. */
1325 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1326 + l->l_info[DT_SONAME]->d_un.d_val);
1327 size_t len = strlen (dsoname);
1328 char *copy = malloc (len);
1329 if (copy == NULL)
1330 _dl_fatal_printf ("out of memory\n");
1331 l->l_libname->name = memcpy (copy, dsoname, len);
1334 /* Rearrange the list so this DSO appears after rtld_map. */
1335 assert (l->l_next == NULL);
1336 assert (l->l_prev == main_map);
1337 GL(dl_rtld_map).l_next = l;
1338 l->l_prev = &GL(dl_rtld_map);
1339 first_preload = &l->l_next;
1341 /* We have a prelinked DSO preloaded by the system. */
1342 GLRO(dl_sysinfo_map) = l;
1343 # ifdef NEED_DL_SYSINFO
1344 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1345 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1346 # endif
1349 #endif
1351 #ifdef DL_SYSDEP_OSCHECK
1352 DL_SYSDEP_OSCHECK (dl_fatal);
1353 #endif
1355 /* Initialize the data structures for the search paths for shared
1356 objects. */
1357 _dl_init_paths (library_path);
1359 /* Initialize _r_debug. */
1360 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1361 LM_ID_BASE);
1362 r->r_state = RT_CONSISTENT;
1364 /* Put the link_map for ourselves on the chain so it can be found by
1365 name. Note that at this point the global chain of link maps contains
1366 exactly one element, which is pointed to by dl_loaded. */
1367 if (! GL(dl_rtld_map).l_name)
1368 /* If not invoked directly, the dynamic linker shared object file was
1369 found by the PT_INTERP name. */
1370 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1371 GL(dl_rtld_map).l_type = lt_library;
1372 main_map->l_next = &GL(dl_rtld_map);
1373 GL(dl_rtld_map).l_prev = main_map;
1374 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1375 ++GL(dl_load_adds);
1377 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1378 to not using bias for non-prelinked PIEs and libraries
1379 and using it for executables or prelinked PIEs or libraries. */
1380 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1381 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1383 /* Set up the program header information for the dynamic linker
1384 itself. It is needed in the dl_iterate_phdr() callbacks. */
1385 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1386 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1387 + rtld_ehdr->e_phoff);
1388 GL(dl_rtld_map).l_phdr = rtld_phdr;
1389 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1392 /* PT_GNU_RELRO is usually the last phdr. */
1393 size_t cnt = rtld_ehdr->e_phnum;
1394 while (cnt-- > 0)
1395 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1397 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1398 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1399 break;
1402 #ifdef USE_TLS
1403 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1404 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1405 /* Assign a module ID. Do this before loading any audit modules. */
1406 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1407 #endif
1409 /* If we have auditing DSOs to load, do it now. */
1410 if (__builtin_expect (audit_list != NULL, 0))
1412 /* Iterate over all entries in the list. The order is important. */
1413 struct audit_ifaces *last_audit = NULL;
1414 struct audit_list *al = audit_list->next;
1417 #ifdef USE_TLS
1418 int tls_idx = GL(dl_tls_max_dtv_idx);
1420 /* Now it is time to determine the layout of the static TLS
1421 block and allocate it for the initial thread. Note that we
1422 always allocate the static block, we never defer it even if
1423 no DF_STATIC_TLS bit is set. The reason is that we know
1424 glibc will use the static model. */
1426 /* Since we start using the auditing DSOs right away we need to
1427 initialize the data structures now. */
1428 tcbp = init_tls ();
1429 #endif
1430 struct dlmopen_args dlmargs;
1431 dlmargs.fname = al->name;
1432 dlmargs.map = NULL;
1434 const char *objname;
1435 const char *err_str = NULL;
1436 bool malloced;
1437 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1438 &dlmargs);
1439 if (__builtin_expect (err_str != NULL, 0))
1441 not_loaded:
1442 _dl_error_printf ("\
1443 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1444 al->name, err_str);
1445 if (malloced)
1446 free ((char *) err_str);
1448 else
1450 struct lookup_args largs;
1451 largs.name = "la_version";
1452 largs.map = dlmargs.map;
1454 /* Check whether the interface version matches. */
1455 (void) _dl_catch_error (&objname, &err_str, &malloced,
1456 lookup_doit, &largs);
1458 unsigned int (*laversion) (unsigned int);
1459 unsigned int lav;
1460 if (err_str == NULL
1461 && (laversion = largs.result) != NULL
1462 && (lav = laversion (LAV_CURRENT)) > 0
1463 && lav <= LAV_CURRENT)
1465 /* Allocate structure for the callback function pointers.
1466 This call can never fail. */
1467 union
1469 struct audit_ifaces ifaces;
1470 #define naudit_ifaces 8
1471 void (*fptr[naudit_ifaces]) (void);
1472 } *newp = malloc (sizeof (*newp));
1474 /* Names of the auditing interfaces. All in one
1475 long string. */
1476 static const char audit_iface_names[] =
1477 "la_activity\0"
1478 "la_objsearch\0"
1479 "la_objopen\0"
1480 "la_preinit\0"
1481 #if __ELF_NATIVE_CLASS == 32
1482 "la_symbind32\0"
1483 #elif __ELF_NATIVE_CLASS == 64
1484 "la_symbind64\0"
1485 #else
1486 # error "__ELF_NATIVE_CLASS must be defined"
1487 #endif
1488 #define STRING(s) __STRING (s)
1489 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1490 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1491 "la_objclose\0";
1492 unsigned int cnt = 0;
1493 const char *cp = audit_iface_names;
1496 largs.name = cp;
1497 (void) _dl_catch_error (&objname, &err_str, &malloced,
1498 lookup_doit, &largs);
1500 /* Store the pointer. */
1501 if (err_str == NULL && largs.result != NULL)
1503 newp->fptr[cnt] = largs.result;
1505 /* The dynamic linker link map is statically
1506 allocated, initialize the data now. */
1507 GL(dl_rtld_map).l_audit[cnt].cookie
1508 = (intptr_t) &GL(dl_rtld_map);
1510 else
1511 newp->fptr[cnt] = NULL;
1512 ++cnt;
1514 cp = (char *) rawmemchr (cp, '\0') + 1;
1516 while (*cp != '\0');
1517 assert (cnt == naudit_ifaces);
1519 /* Now append the new auditing interface to the list. */
1520 newp->ifaces.next = NULL;
1521 if (last_audit == NULL)
1522 last_audit = GLRO(dl_audit) = &newp->ifaces;
1523 else
1524 last_audit = last_audit->next = &newp->ifaces;
1525 ++GLRO(dl_naudit);
1527 /* Mark the DSO as being used for auditing. */
1528 dlmargs.map->l_auditing = 1;
1530 else
1532 /* We cannot use the DSO, it does not have the
1533 appropriate interfaces or it expects something
1534 more recent. */
1535 #ifndef NDEBUG
1536 Lmid_t ns = dlmargs.map->l_ns;
1537 #endif
1538 _dl_close (dlmargs.map);
1540 /* Make sure the namespace has been cleared entirely. */
1541 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1542 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1544 #ifdef USE_TLS
1545 GL(dl_tls_max_dtv_idx) = tls_idx;
1546 #endif
1547 goto not_loaded;
1551 al = al->next;
1553 while (al != audit_list->next);
1555 /* If we have any auditing modules, announce that we already
1556 have two objects loaded. */
1557 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1559 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1561 for (unsigned int outer = 0; outer < 2; ++outer)
1563 struct audit_ifaces *afct = GLRO(dl_audit);
1564 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1566 if (afct->objopen != NULL)
1568 ls[outer]->l_audit[cnt].bindflags
1569 = afct->objopen (ls[outer], LM_ID_BASE,
1570 &ls[outer]->l_audit[cnt].cookie);
1572 ls[outer]->l_audit_any_plt
1573 |= ls[outer]->l_audit[cnt].bindflags != 0;
1576 afct = afct->next;
1582 /* Set up debugging before the debugger is notified for the first time. */
1583 #ifdef ELF_MACHINE_DEBUG_SETUP
1584 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1585 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1586 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1587 #else
1588 if (main_map->l_info[DT_DEBUG] != NULL)
1589 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1590 with the run-time address of the r_debug structure */
1591 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1593 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1594 case you run gdb on the dynamic linker directly. */
1595 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1596 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1597 #endif
1599 /* We start adding objects. */
1600 r->r_state = RT_ADD;
1601 _dl_debug_state ();
1603 /* Auditing checkpoint: we are ready to signal that the initial map
1604 is being constructed. */
1605 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1607 struct audit_ifaces *afct = GLRO(dl_audit);
1608 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1610 if (afct->activity != NULL)
1611 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1613 afct = afct->next;
1617 /* We have two ways to specify objects to preload: via environment
1618 variable and via the file /etc/ld.so.preload. The latter can also
1619 be used when security is enabled. */
1620 assert (*first_preload == NULL);
1621 struct link_map **preloads = NULL;
1622 unsigned int npreloads = 0;
1624 if (__builtin_expect (preloadlist != NULL, 0))
1626 /* The LD_PRELOAD environment variable gives list of libraries
1627 separated by white space or colons that are loaded before the
1628 executable's dependencies and prepended to the global scope
1629 list. If the binary is running setuid all elements
1630 containing a '/' are ignored since it is insecure. */
1631 char *list = strdupa (preloadlist);
1632 char *p;
1634 HP_TIMING_NOW (start);
1636 /* Prevent optimizing strsep. Speed is not important here. */
1637 while ((p = (strsep) (&list, " :")) != NULL)
1638 if (p[0] != '\0'
1639 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1640 || strchr (p, '/') == NULL))
1641 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1643 HP_TIMING_NOW (stop);
1644 HP_TIMING_DIFF (diff, start, stop);
1645 HP_TIMING_ACCUM_NT (load_time, diff);
1648 /* There usually is no ld.so.preload file, it should only be used
1649 for emergencies and testing. So the open call etc should usually
1650 fail. Using access() on a non-existing file is faster than using
1651 open(). So we do this first. If it succeeds we do almost twice
1652 the work but this does not matter, since it is not for production
1653 use. */
1654 static const char preload_file[] = "/etc/ld.so.preload";
1655 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1657 /* Read the contents of the file. */
1658 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1659 PROT_READ | PROT_WRITE);
1660 if (__builtin_expect (file != MAP_FAILED, 0))
1662 /* Parse the file. It contains names of libraries to be loaded,
1663 separated by white spaces or `:'. It may also contain
1664 comments introduced by `#'. */
1665 char *problem;
1666 char *runp;
1667 size_t rest;
1669 /* Eliminate comments. */
1670 runp = file;
1671 rest = file_size;
1672 while (rest > 0)
1674 char *comment = memchr (runp, '#', rest);
1675 if (comment == NULL)
1676 break;
1678 rest -= comment - runp;
1680 *comment = ' ';
1681 while (--rest > 0 && *++comment != '\n');
1684 /* We have one problematic case: if we have a name at the end of
1685 the file without a trailing terminating characters, we cannot
1686 place the \0. Handle the case separately. */
1687 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1688 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1690 problem = &file[file_size];
1691 while (problem > file && problem[-1] != ' '
1692 && problem[-1] != '\t'
1693 && problem[-1] != '\n' && problem[-1] != ':')
1694 --problem;
1696 if (problem > file)
1697 problem[-1] = '\0';
1699 else
1701 problem = NULL;
1702 file[file_size - 1] = '\0';
1705 HP_TIMING_NOW (start);
1707 if (file != problem)
1709 char *p;
1710 runp = file;
1711 while ((p = strsep (&runp, ": \t\n")) != NULL)
1712 if (p[0] != '\0')
1713 npreloads += do_preload (p, main_map, preload_file);
1716 if (problem != NULL)
1718 char *p = strndupa (problem, file_size - (problem - file));
1720 npreloads += do_preload (p, main_map, preload_file);
1723 HP_TIMING_NOW (stop);
1724 HP_TIMING_DIFF (diff, start, stop);
1725 HP_TIMING_ACCUM_NT (load_time, diff);
1727 /* We don't need the file anymore. */
1728 __munmap (file, file_size);
1732 if (__builtin_expect (*first_preload != NULL, 0))
1734 /* Set up PRELOADS with a vector of the preloaded libraries. */
1735 struct link_map *l = *first_preload;
1736 preloads = __alloca (npreloads * sizeof preloads[0]);
1737 i = 0;
1740 preloads[i++] = l;
1741 l = l->l_next;
1742 } while (l);
1743 assert (i == npreloads);
1746 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1747 specified some libraries to load, these are inserted before the actual
1748 dependencies in the executable's searchlist for symbol resolution. */
1749 HP_TIMING_NOW (start);
1750 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1751 HP_TIMING_NOW (stop);
1752 HP_TIMING_DIFF (diff, start, stop);
1753 HP_TIMING_ACCUM_NT (load_time, diff);
1755 /* Mark all objects as being in the global scope. */
1756 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1757 main_map->l_searchlist.r_list[--i]->l_global = 1;
1759 #ifndef MAP_ANON
1760 /* We are done mapping things, so close the zero-fill descriptor. */
1761 __close (_dl_zerofd);
1762 _dl_zerofd = -1;
1763 #endif
1765 /* Remove _dl_rtld_map from the chain. */
1766 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1767 if (GL(dl_rtld_map).l_next != NULL)
1768 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1770 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1771 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1772 break;
1774 bool rtld_multiple_ref = false;
1775 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1777 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1778 put it back in the list of visible objects. We insert it into the
1779 chain in symbol search order because gdb uses the chain's order as
1780 its symbol search order. */
1781 rtld_multiple_ref = true;
1783 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1784 if (__builtin_expect (mode, normal) == normal)
1786 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1787 ? main_map->l_searchlist.r_list[i + 1]
1788 : NULL);
1789 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1790 if (GLRO(dl_sysinfo_map) != NULL
1791 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1792 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1793 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1794 #endif
1796 else
1797 /* In trace mode there might be an invisible object (which we
1798 could not find) after the previous one in the search list.
1799 In this case it doesn't matter much where we put the
1800 interpreter object, so we just initialize the list pointer so
1801 that the assertion below holds. */
1802 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1804 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1805 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1806 if (GL(dl_rtld_map).l_next != NULL)
1808 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1809 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1813 /* Now let us see whether all libraries are available in the
1814 versions we need. */
1816 struct version_check_args args;
1817 args.doexit = mode == normal;
1818 args.dotrace = mode == trace;
1819 _dl_receive_error (print_missing_version, version_check_doit, &args);
1822 #ifdef USE_TLS
1823 /* We do not initialize any of the TLS functionality unless any of the
1824 initial modules uses TLS. This makes dynamic loading of modules with
1825 TLS impossible, but to support it requires either eagerly doing setup
1826 now or lazily doing it later. Doing it now makes us incompatible with
1827 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1828 used. Trying to do it lazily is too hairy to try when there could be
1829 multiple threads (from a non-TLS-using libpthread). */
1830 bool was_tls_init_tp_called = tls_init_tp_called;
1831 if (tcbp == NULL)
1832 tcbp = init_tls ();
1833 #endif
1835 /* Set up the stack checker's canary. */
1836 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
1837 #ifdef THREAD_SET_STACK_GUARD
1838 THREAD_SET_STACK_GUARD (stack_chk_guard);
1839 #else
1840 __stack_chk_guard = stack_chk_guard;
1841 #endif
1843 /* Set up the pointer guard as well, if necessary. */
1844 if (GLRO(dl_pointer_guard))
1846 // XXX If it is cheap, we should use a separate value.
1847 uintptr_t pointer_chk_guard = stack_chk_guard;
1848 #ifndef HP_TIMING_NONAVAIL
1849 hp_timing_t now;
1850 HP_TIMING_NOW (now);
1851 pointer_chk_guard ^= now;
1852 #endif
1853 #ifdef THREAD_SET_POINTER_GUARD
1854 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
1855 #endif
1856 __pointer_chk_guard_local = pointer_chk_guard;
1859 if (__builtin_expect (mode, normal) != normal)
1861 /* We were run just to list the shared libraries. It is
1862 important that we do this before real relocation, because the
1863 functions we call below for output may no longer work properly
1864 after relocation. */
1865 struct link_map *l;
1867 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1869 struct r_scope_elem *scope = &main_map->l_searchlist;
1871 for (i = 0; i < scope->r_nlist; i++)
1873 l = scope->r_list [i];
1874 if (l->l_faked)
1876 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1877 continue;
1879 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1880 GLRO(dl_trace_prelink_map) = l;
1881 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1882 l->l_libname->name[0] ? l->l_libname->name
1883 : rtld_progname ?: "<main program>",
1884 l->l_name[0] ? l->l_name
1885 : rtld_progname ?: "<main program>",
1886 (int) sizeof l->l_map_start * 2,
1887 (size_t) l->l_map_start,
1888 (int) sizeof l->l_addr * 2,
1889 (size_t) l->l_addr);
1890 #ifdef USE_TLS
1891 if (l->l_tls_modid)
1892 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1893 (int) sizeof l->l_tls_offset * 2,
1894 (size_t) l->l_tls_offset);
1895 else
1896 #endif
1897 _dl_printf ("\n");
1900 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1902 /* Look through the dependencies of the main executable
1903 and determine which of them is not actually
1904 required. */
1905 struct link_map *l = main_map;
1907 /* Relocate the main executable. */
1908 struct relocate_args args = { .l = l, .lazy = GLRO(dl_lazy) };
1909 _dl_receive_error (print_unresolved, relocate_doit, &args);
1911 /* This loop depends on the dependencies of the executable to
1912 correspond in number and order to the DT_NEEDED entries. */
1913 ElfW(Dyn) *dyn = main_map->l_ld;
1914 bool first = true;
1915 while (dyn->d_tag != DT_NULL)
1917 if (dyn->d_tag == DT_NEEDED)
1919 l = l->l_next;
1921 if (!l->l_used)
1923 if (first)
1925 _dl_printf ("Unused direct dependencies:\n");
1926 first = false;
1929 _dl_printf ("\t%s\n", l->l_name);
1933 ++dyn;
1936 _exit (first != true);
1938 else if (! main_map->l_info[DT_NEEDED])
1939 _dl_printf ("\tstatically linked\n");
1940 else
1942 for (l = main_map->l_next; l; l = l->l_next)
1943 if (l->l_faked)
1944 /* The library was not found. */
1945 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1946 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1947 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1948 (int) sizeof l->l_map_start * 2,
1949 (size_t) l->l_map_start);
1950 else
1951 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1952 l->l_name, (int) sizeof l->l_map_start * 2,
1953 (size_t) l->l_map_start);
1956 if (__builtin_expect (mode, trace) != trace)
1957 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1959 const ElfW(Sym) *ref = NULL;
1960 ElfW(Addr) loadbase;
1961 lookup_t result;
1963 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1964 &ref, main_map->l_scope, NULL,
1965 ELF_RTYPE_CLASS_PLT,
1966 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1968 loadbase = LOOKUP_VALUE_ADDRESS (result);
1970 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1971 INTUSE(_dl_argv)[i],
1972 (int) sizeof ref->st_value * 2,
1973 (size_t) ref->st_value,
1974 (int) sizeof loadbase * 2, (size_t) loadbase);
1976 else
1978 /* If LD_WARN is set, warn about undefined symbols. */
1979 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
1981 /* We have to do symbol dependency testing. */
1982 struct relocate_args args;
1983 struct link_map *l;
1985 args.lazy = GLRO(dl_lazy);
1987 l = main_map;
1988 while (l->l_next != NULL)
1989 l = l->l_next;
1992 if (l != &GL(dl_rtld_map) && ! l->l_faked)
1994 args.l = l;
1995 _dl_receive_error (print_unresolved, relocate_doit,
1996 &args);
1998 l = l->l_prev;
2000 while (l != NULL);
2002 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2003 && rtld_multiple_ref)
2005 /* Mark the link map as not yet relocated again. */
2006 GL(dl_rtld_map).l_relocated = 0;
2007 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope,
2008 0, 0);
2011 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2012 if (version_info)
2014 /* Print more information. This means here, print information
2015 about the versions needed. */
2016 int first = 1;
2017 struct link_map *map;
2019 for (map = main_map; map != NULL; map = map->l_next)
2021 const char *strtab;
2022 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2023 ElfW(Verneed) *ent;
2025 if (dyn == NULL)
2026 continue;
2028 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2029 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2031 if (first)
2033 _dl_printf ("\n\tVersion information:\n");
2034 first = 0;
2037 _dl_printf ("\t%s:\n",
2038 map->l_name[0] ? map->l_name : rtld_progname);
2040 while (1)
2042 ElfW(Vernaux) *aux;
2043 struct link_map *needed;
2045 needed = find_needed (strtab + ent->vn_file);
2046 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2048 while (1)
2050 const char *fname = NULL;
2052 if (needed != NULL
2053 && match_version (strtab + aux->vna_name,
2054 needed))
2055 fname = needed->l_name;
2057 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2058 strtab + ent->vn_file,
2059 strtab + aux->vna_name,
2060 aux->vna_flags & VER_FLG_WEAK
2061 ? "[WEAK] " : "",
2062 fname ?: "not found");
2064 if (aux->vna_next == 0)
2065 /* No more symbols. */
2066 break;
2068 /* Next symbol. */
2069 aux = (ElfW(Vernaux) *) ((char *) aux
2070 + aux->vna_next);
2073 if (ent->vn_next == 0)
2074 /* No more dependencies. */
2075 break;
2077 /* Next dependency. */
2078 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2084 _exit (0);
2087 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2088 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0))
2090 ElfW(Lib) *liblist, *liblistend;
2091 struct link_map **r_list, **r_listend, *l;
2092 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2094 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2095 liblist = (ElfW(Lib) *)
2096 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2097 liblistend = (ElfW(Lib) *)
2098 ((char *) liblist +
2099 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2100 r_list = main_map->l_searchlist.r_list;
2101 r_listend = r_list + main_map->l_searchlist.r_nlist;
2103 for (; r_list < r_listend && liblist < liblistend; r_list++)
2105 l = *r_list;
2107 if (l == main_map)
2108 continue;
2110 /* If the library is not mapped where it should, fail. */
2111 if (l->l_addr)
2112 break;
2114 /* Next, check if checksum matches. */
2115 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2116 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2117 != liblist->l_checksum)
2118 break;
2120 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2121 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2122 != liblist->l_time_stamp)
2123 break;
2125 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2126 break;
2128 ++liblist;
2132 if (r_list == r_listend && liblist == liblistend)
2133 prelinked = true;
2135 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2136 _dl_debug_printf ("\nprelink checking: %s\n",
2137 prelinked ? "ok" : "failed");
2141 /* Now set up the variable which helps the assembler startup code. */
2142 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2143 GL(dl_ns)[LM_ID_BASE]._ns_global_scope[0] = &main_map->l_searchlist;
2145 /* Save the information about the original global scope list since
2146 we need it in the memory handling later. */
2147 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2149 if (prelinked)
2151 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2153 ElfW(Rela) *conflict, *conflictend;
2154 #ifndef HP_TIMING_NONAVAIL
2155 hp_timing_t start;
2156 hp_timing_t stop;
2157 #endif
2159 HP_TIMING_NOW (start);
2160 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2161 conflict = (ElfW(Rela) *)
2162 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2163 conflictend = (ElfW(Rela) *)
2164 ((char *) conflict
2165 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2166 _dl_resolve_conflicts (main_map, conflict, conflictend);
2167 HP_TIMING_NOW (stop);
2168 HP_TIMING_DIFF (relocate_time, start, stop);
2172 /* Mark all the objects so we know they have been already relocated. */
2173 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2175 l->l_relocated = 1;
2176 if (l->l_relro_size)
2177 _dl_protect_relro (l);
2179 #ifdef USE_TLS
2180 /* Add object to slot information data if necessasy. */
2181 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2182 _dl_add_to_slotinfo (l);
2183 #endif
2186 _dl_sysdep_start_cleanup ();
2188 else
2190 /* Now we have all the objects loaded. Relocate them all except for
2191 the dynamic linker itself. We do this in reverse order so that copy
2192 relocs of earlier objects overwrite the data written by later
2193 objects. We do not re-relocate the dynamic linker itself in this
2194 loop because that could result in the GOT entries for functions we
2195 call being changed, and that would break us. It is safe to relocate
2196 the dynamic linker out of order because it has no copy relocs (we
2197 know that because it is self-contained). */
2199 int consider_profiling = GLRO(dl_profile) != NULL;
2200 #ifndef HP_TIMING_NONAVAIL
2201 hp_timing_t start;
2202 hp_timing_t stop;
2203 hp_timing_t add;
2204 #endif
2206 /* If we are profiling we also must do lazy reloaction. */
2207 GLRO(dl_lazy) |= consider_profiling;
2209 struct link_map *l = main_map;
2210 while (l->l_next)
2211 l = l->l_next;
2213 HP_TIMING_NOW (start);
2216 /* While we are at it, help the memory handling a bit. We have to
2217 mark some data structures as allocated with the fake malloc()
2218 implementation in ld.so. */
2219 struct libname_list *lnp = l->l_libname->next;
2221 while (__builtin_expect (lnp != NULL, 0))
2223 lnp->dont_free = 1;
2224 lnp = lnp->next;
2227 if (l != &GL(dl_rtld_map))
2228 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy),
2229 consider_profiling);
2231 #ifdef USE_TLS
2232 /* Add object to slot information data if necessasy. */
2233 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2234 _dl_add_to_slotinfo (l);
2235 #endif
2237 l = l->l_prev;
2239 while (l);
2240 HP_TIMING_NOW (stop);
2242 HP_TIMING_DIFF (relocate_time, start, stop);
2244 /* Do any necessary cleanups for the startup OS interface code.
2245 We do these now so that no calls are made after rtld re-relocation
2246 which might be resolved to different functions than we expect.
2247 We cannot do this before relocating the other objects because
2248 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2249 _dl_sysdep_start_cleanup ();
2251 /* Now enable profiling if needed. Like the previous call,
2252 this has to go here because the calls it makes should use the
2253 rtld versions of the functions (particularly calloc()), but it
2254 needs to have _dl_profile_map set up by the relocator. */
2255 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2256 /* We must prepare the profiling. */
2257 _dl_start_profile ();
2259 if (rtld_multiple_ref)
2261 /* There was an explicit ref to the dynamic linker as a shared lib.
2262 Re-relocate ourselves with user-controlled symbol definitions. */
2263 HP_TIMING_NOW (start);
2264 /* Mark the link map as not yet relocated again. */
2265 GL(dl_rtld_map).l_relocated = 0;
2266 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2267 HP_TIMING_NOW (stop);
2268 HP_TIMING_DIFF (add, start, stop);
2269 HP_TIMING_ACCUM_NT (relocate_time, add);
2273 #ifndef NONTLS_INIT_TP
2274 # define NONTLS_INIT_TP do { } while (0)
2275 #endif
2277 #ifdef USE_TLS
2278 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2279 ++GL(dl_tls_generation);
2281 /* Now that we have completed relocation, the initializer data
2282 for the TLS blocks has its final values and we can copy them
2283 into the main thread's TLS area, which we allocated above. */
2284 _dl_allocate_tls_init (tcbp);
2286 /* And finally install it for the main thread. If ld.so itself uses
2287 TLS we know the thread pointer was initialized earlier. */
2288 if (! tls_init_tp_called)
2290 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2291 if (__builtin_expect (lossage != NULL, 0))
2292 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2293 lossage);
2295 #else
2296 NONTLS_INIT_TP;
2297 #endif
2299 #ifdef SHARED
2300 /* Auditing checkpoint: we have added all objects. */
2301 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2303 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2304 /* Do not call the functions for any auditing object. */
2305 if (head->l_auditing == 0)
2307 struct audit_ifaces *afct = GLRO(dl_audit);
2308 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2310 if (afct->activity != NULL)
2311 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2313 afct = afct->next;
2317 #endif
2319 /* Notify the debugger all new objects are now ready to go. We must re-get
2320 the address since by now the variable might be in another object. */
2321 r = _dl_debug_initialize (0, LM_ID_BASE);
2322 r->r_state = RT_CONSISTENT;
2323 _dl_debug_state ();
2325 #ifndef MAP_COPY
2326 /* We must munmap() the cache file. */
2327 _dl_unload_cache ();
2328 #endif
2330 /* Once we return, _dl_sysdep_start will invoke
2331 the DT_INIT functions and then *USER_ENTRY. */
2334 /* This is a little helper function for resolving symbols while
2335 tracing the binary. */
2336 static void
2337 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2338 const char *errstring)
2340 if (objname[0] == '\0')
2341 objname = rtld_progname ?: "<main program>";
2342 _dl_error_printf ("%s (%s)\n", errstring, objname);
2345 /* This is a little helper function for resolving symbols while
2346 tracing the binary. */
2347 static void
2348 print_missing_version (int errcode __attribute__ ((unused)),
2349 const char *objname, const char *errstring)
2351 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2352 objname, errstring);
2355 /* Nonzero if any of the debugging options is enabled. */
2356 static int any_debug attribute_relro;
2358 /* Process the string given as the parameter which explains which debugging
2359 options are enabled. */
2360 static void
2361 process_dl_debug (const char *dl_debug)
2363 /* When adding new entries make sure that the maximal length of a name
2364 is correctly handled in the LD_DEBUG_HELP code below. */
2365 static const struct
2367 unsigned char len;
2368 const char name[10];
2369 const char helptext[41];
2370 unsigned short int mask;
2371 } debopts[] =
2373 #define LEN_AND_STR(str) sizeof (str) - 1, str
2374 { LEN_AND_STR ("libs"), "display library search paths",
2375 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2376 { LEN_AND_STR ("reloc"), "display relocation processing",
2377 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2378 { LEN_AND_STR ("files"), "display progress for input file",
2379 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2380 { LEN_AND_STR ("symbols"), "display symbol table processing",
2381 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2382 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2383 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2384 { LEN_AND_STR ("versions"), "display version dependencies",
2385 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2386 { LEN_AND_STR ("all"), "all previous options combined",
2387 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2388 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2389 { LEN_AND_STR ("statistics"), "display relocation statistics",
2390 DL_DEBUG_STATISTICS },
2391 { LEN_AND_STR ("unused"), "determined unused DSOs",
2392 DL_DEBUG_UNUSED },
2393 { LEN_AND_STR ("help"), "display this help message and exit",
2394 DL_DEBUG_HELP },
2396 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2398 /* Skip separating white spaces and commas. */
2399 while (*dl_debug != '\0')
2401 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2403 size_t cnt;
2404 size_t len = 1;
2406 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2407 && dl_debug[len] != ',' && dl_debug[len] != ':')
2408 ++len;
2410 for (cnt = 0; cnt < ndebopts; ++cnt)
2411 if (debopts[cnt].len == len
2412 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2414 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2415 any_debug = 1;
2416 break;
2419 if (cnt == ndebopts)
2421 /* Display a warning and skip everything until next
2422 separator. */
2423 char *copy = strndupa (dl_debug, len);
2424 _dl_error_printf ("\
2425 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2428 dl_debug += len;
2429 continue;
2432 ++dl_debug;
2435 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2437 size_t cnt;
2439 _dl_printf ("\
2440 Valid options for the LD_DEBUG environment variable are:\n\n");
2442 for (cnt = 0; cnt < ndebopts; ++cnt)
2443 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2444 " " + debopts[cnt].len - 3,
2445 debopts[cnt].helptext);
2447 _dl_printf ("\n\
2448 To direct the debugging output into a file instead of standard output\n\
2449 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2450 _exit (0);
2454 static void
2455 process_dl_audit (char *str)
2457 /* The parameter is a colon separated list of DSO names. */
2458 char *p;
2460 while ((p = (strsep) (&str, ":")) != NULL)
2461 if (p[0] != '\0'
2462 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2463 || strchr (p, '/') == NULL))
2465 /* This is using the local malloc, not the system malloc. The
2466 memory can never be freed. */
2467 struct audit_list *newp = malloc (sizeof (*newp));
2468 newp->name = p;
2470 if (audit_list == NULL)
2471 audit_list = newp->next = newp;
2472 else
2474 newp->next = audit_list->next;
2475 audit_list = audit_list->next = newp;
2480 /* Process all environments variables the dynamic linker must recognize.
2481 Since all of them start with `LD_' we are a bit smarter while finding
2482 all the entries. */
2483 extern char **_environ attribute_hidden;
2486 static void
2487 process_envvars (enum mode *modep)
2489 char **runp = _environ;
2490 char *envline;
2491 enum mode mode = normal;
2492 char *debug_output = NULL;
2494 /* This is the default place for profiling data file. */
2495 GLRO(dl_profile_output)
2496 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2498 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2500 size_t len = 0;
2502 while (envline[len] != '\0' && envline[len] != '=')
2503 ++len;
2505 if (envline[len] != '=')
2506 /* This is a "LD_" variable at the end of the string without
2507 a '=' character. Ignore it since otherwise we will access
2508 invalid memory below. */
2509 continue;
2511 switch (len)
2513 case 4:
2514 /* Warning level, verbose or not. */
2515 if (memcmp (envline, "WARN", 4) == 0)
2516 GLRO(dl_verbose) = envline[5] != '\0';
2517 break;
2519 case 5:
2520 /* Debugging of the dynamic linker? */
2521 if (memcmp (envline, "DEBUG", 5) == 0)
2523 process_dl_debug (&envline[6]);
2524 break;
2526 if (memcmp (envline, "AUDIT", 5) == 0)
2527 process_dl_audit (&envline[6]);
2528 break;
2530 case 7:
2531 /* Print information about versions. */
2532 if (memcmp (envline, "VERBOSE", 7) == 0)
2534 version_info = envline[8] != '\0';
2535 break;
2538 /* List of objects to be preloaded. */
2539 if (memcmp (envline, "PRELOAD", 7) == 0)
2541 preloadlist = &envline[8];
2542 break;
2545 /* Which shared object shall be profiled. */
2546 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2547 GLRO(dl_profile) = &envline[8];
2548 break;
2550 case 8:
2551 /* Do we bind early? */
2552 if (memcmp (envline, "BIND_NOW", 8) == 0)
2554 GLRO(dl_lazy) = envline[9] == '\0';
2555 break;
2557 if (memcmp (envline, "BIND_NOT", 8) == 0)
2558 GLRO(dl_bind_not) = envline[9] != '\0';
2559 break;
2561 case 9:
2562 /* Test whether we want to see the content of the auxiliary
2563 array passed up from the kernel. */
2564 if (!INTUSE(__libc_enable_secure)
2565 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2566 _dl_show_auxv ();
2567 break;
2569 case 10:
2570 /* Mask for the important hardware capabilities. */
2571 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2572 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2573 0, 0);
2574 break;
2576 case 11:
2577 /* Path where the binary is found. */
2578 if (!INTUSE(__libc_enable_secure)
2579 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2580 GLRO(dl_origin_path) = &envline[12];
2581 break;
2583 case 12:
2584 /* The library search path. */
2585 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2587 library_path = &envline[13];
2588 break;
2591 /* Where to place the profiling data file. */
2592 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2594 debug_output = &envline[13];
2595 break;
2598 if (!INTUSE(__libc_enable_secure)
2599 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2600 GLRO(dl_dynamic_weak) = 1;
2601 break;
2603 case 13:
2604 /* We might have some extra environment variable with length 13
2605 to handle. */
2606 #ifdef EXTRA_LD_ENVVARS_13
2607 EXTRA_LD_ENVVARS_13
2608 #endif
2609 if (!INTUSE(__libc_enable_secure)
2610 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2612 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2613 break;
2616 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2617 GLRO(dl_pointer_guard) = envline[14] == '0';
2618 break;
2620 case 14:
2621 /* Where to place the profiling data file. */
2622 if (!INTUSE(__libc_enable_secure)
2623 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2624 && envline[15] != '\0')
2625 GLRO(dl_profile_output) = &envline[15];
2626 break;
2628 case 16:
2629 /* The mode of the dynamic linker can be set. */
2630 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2632 mode = trace;
2633 GLRO(dl_verbose) = 1;
2634 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2635 GLRO(dl_trace_prelink) = &envline[17];
2637 break;
2639 case 20:
2640 /* The mode of the dynamic linker can be set. */
2641 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2642 mode = trace;
2643 break;
2645 /* We might have some extra environment variable to handle. This
2646 is tricky due to the pre-processing of the length of the name
2647 in the switch statement here. The code here assumes that added
2648 environment variables have a different length. */
2649 #ifdef EXTRA_LD_ENVVARS
2650 EXTRA_LD_ENVVARS
2651 #endif
2655 /* The caller wants this information. */
2656 *modep = mode;
2658 /* Extra security for SUID binaries. Remove all dangerous environment
2659 variables. */
2660 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2662 static const char unsecure_envvars[] =
2663 #ifdef EXTRA_UNSECURE_ENVVARS
2664 EXTRA_UNSECURE_ENVVARS
2665 #endif
2666 UNSECURE_ENVVARS;
2667 const char *nextp;
2669 nextp = unsecure_envvars;
2672 unsetenv (nextp);
2673 /* We could use rawmemchr but this need not be fast. */
2674 nextp = (char *) (strchr) (nextp, '\0') + 1;
2676 while (*nextp != '\0');
2678 if (__access ("/etc/suid-debug", F_OK) != 0)
2680 unsetenv ("MALLOC_CHECK_");
2681 GLRO(dl_debug_mask) = 0;
2684 if (mode != normal)
2685 _exit (5);
2687 /* If we have to run the dynamic linker in debugging mode and the
2688 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2689 messages to this file. */
2690 else if (any_debug && debug_output != NULL)
2692 #ifdef O_NOFOLLOW
2693 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2694 #else
2695 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2696 #endif
2697 size_t name_len = strlen (debug_output);
2698 char buf[name_len + 12];
2699 char *startp;
2701 buf[name_len + 11] = '\0';
2702 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2703 *--startp = '.';
2704 startp = memcpy (startp - name_len, debug_output, name_len);
2706 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2707 if (GLRO(dl_debug_fd) == -1)
2708 /* We use standard output if opening the file failed. */
2709 GLRO(dl_debug_fd) = STDOUT_FILENO;
2714 /* Print the various times we collected. */
2715 static void
2716 __attribute ((noinline))
2717 print_statistics (hp_timing_t *rtld_total_timep)
2719 #ifndef HP_TIMING_NONAVAIL
2720 char buf[200];
2721 char *cp;
2722 char *wp;
2724 /* Total time rtld used. */
2725 if (HP_TIMING_AVAIL)
2727 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2728 _dl_debug_printf ("\nruntime linker statistics:\n"
2729 " total startup time in dynamic loader: %s\n", buf);
2731 /* Print relocation statistics. */
2732 char pbuf[30];
2733 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2734 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2735 pbuf + sizeof (pbuf), 10, 0);
2736 wp = pbuf;
2737 switch (pbuf + sizeof (pbuf) - cp)
2739 case 3:
2740 *wp++ = *cp++;
2741 case 2:
2742 *wp++ = *cp++;
2743 case 1:
2744 *wp++ = '.';
2745 *wp++ = *cp++;
2747 *wp = '\0';
2748 _dl_debug_printf ("\
2749 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2751 #endif
2753 unsigned long int num_relative_relocations = 0;
2754 for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
2756 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2757 continue;
2759 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2761 for (unsigned int i = 0; i < scope->r_nlist; i++)
2763 struct link_map *l = scope->r_list [i];
2765 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2766 num_relative_relocations
2767 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2768 #ifndef ELF_MACHINE_REL_RELATIVE
2769 /* Relative relocations are processed on these architectures if
2770 library is loaded to different address than p_vaddr or
2771 if not prelinked. */
2772 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2773 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2774 #else
2775 /* On e.g. IA-64 or Alpha, relative relocations are processed
2776 only if library is loaded to different address than p_vaddr. */
2777 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2778 #endif
2779 num_relative_relocations
2780 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2784 _dl_debug_printf (" number of relocations: %lu\n"
2785 " number of relocations from cache: %lu\n"
2786 " number of relative relocations: %lu\n",
2787 GL(dl_num_relocations),
2788 GL(dl_num_cache_relocations),
2789 num_relative_relocations);
2791 #ifndef HP_TIMING_NONAVAIL
2792 /* Time spend while loading the object and the dependencies. */
2793 if (HP_TIMING_AVAIL)
2795 char pbuf[30];
2796 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2797 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2798 pbuf + sizeof (pbuf), 10, 0);
2799 wp = pbuf;
2800 switch (pbuf + sizeof (pbuf) - cp)
2802 case 3:
2803 *wp++ = *cp++;
2804 case 2:
2805 *wp++ = *cp++;
2806 case 1:
2807 *wp++ = '.';
2808 *wp++ = *cp++;
2810 *wp = '\0';
2811 _dl_debug_printf ("\
2812 time needed to load objects: %s (%s%%)\n",
2813 buf, pbuf);
2815 #endif