Don't try to free rpath strings allocated during startup
[glibc.git] / elf / rtld.c
blob5ecc4fe711c0a2d1b8c3d0186917cf7ac3b799be
1 /* Run time dynamic linker.
2 Copyright (C) 1995-2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h>
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
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 ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
130 #endif
131 ._dl_nns = 1,
132 ._dl_ns =
134 [LM_ID_BASE] = { ._ns_unique_sym_table
135 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
138 /* If we would use strong_alias here the compiler would see a
139 non-hidden definition. This would undo the effect of the previous
140 declaration. So spell out was strong_alias does plus add the
141 visibility attribute. */
142 extern struct rtld_global _rtld_local
143 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
146 /* This variable is similar to _rtld_local, but all values are
147 read-only after relocation. */
148 struct rtld_global_ro _rtld_global_ro attribute_relro =
150 /* Get architecture specific initializer. */
151 #include <dl-procinfo.c>
152 #ifdef NEED_DL_SYSINFO
153 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
154 #endif
155 ._dl_debug_fd = STDERR_FILENO,
156 ._dl_use_load_bias = -2,
157 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
158 ._dl_hwcap_mask = HWCAP_IMPORTANT,
159 ._dl_lazy = 1,
160 ._dl_fpu_control = _FPU_DEFAULT,
161 ._dl_pointer_guard = 1,
163 /* Function pointers. */
164 ._dl_debug_printf = _dl_debug_printf,
165 ._dl_catch_error = _dl_catch_error,
166 ._dl_signal_error = _dl_signal_error,
167 ._dl_mcount = _dl_mcount_internal,
168 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
169 ._dl_check_caller = _dl_check_caller,
170 ._dl_open = _dl_open,
171 ._dl_close = _dl_close,
172 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
173 #ifdef HAVE_DL_DISCOVER_OSVERSION
174 ._dl_discover_osversion = _dl_discover_osversion
175 #endif
177 /* If we would use strong_alias here the compiler would see a
178 non-hidden definition. This would undo the effect of the previous
179 declaration. So spell out was strong_alias does plus add the
180 visibility attribute. */
181 extern struct rtld_global_ro _rtld_local_ro
182 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
185 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
186 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
188 /* These two variables cannot be moved into .data.rel.ro. */
189 static struct libname_list _dl_rtld_libname;
190 static struct libname_list _dl_rtld_libname2;
192 /* We expect less than a second for relocation. */
193 #ifdef HP_SMALL_TIMING_AVAIL
194 # undef HP_TIMING_AVAIL
195 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
196 #endif
198 /* Variable for statistics. */
199 #ifndef HP_TIMING_NONAVAIL
200 static hp_timing_t relocate_time;
201 static hp_timing_t load_time attribute_relro;
202 static hp_timing_t start_time attribute_relro;
203 #endif
205 /* Additional definitions needed by TLS initialization. */
206 #ifdef TLS_INIT_HELPER
207 TLS_INIT_HELPER
208 #endif
210 /* Helper function for syscall implementation. */
211 #ifdef DL_SYSINFO_IMPLEMENTATION
212 DL_SYSINFO_IMPLEMENTATION
213 #endif
215 /* Before ld.so is relocated we must not access variables which need
216 relocations. This means variables which are exported. Variables
217 declared as static are fine. If we can mark a variable hidden this
218 is fine, too. The latter is important here. We can avoid setting
219 up a temporary link map for ld.so if we can mark _rtld_global as
220 hidden. */
221 #ifdef PI_STATIC_AND_HIDDEN
222 # define DONT_USE_BOOTSTRAP_MAP 1
223 #endif
225 #ifdef DONT_USE_BOOTSTRAP_MAP
226 static ElfW(Addr) _dl_start_final (void *arg);
227 #else
228 struct dl_start_final_info
230 struct link_map l;
231 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
232 hp_timing_t start_time;
233 #endif
235 static ElfW(Addr) _dl_start_final (void *arg,
236 struct dl_start_final_info *info);
237 #endif
239 /* These defined magically in the linker script. */
240 extern char _begin[] attribute_hidden;
241 extern char _etext[] attribute_hidden;
242 extern char _end[] attribute_hidden;
245 #ifdef RTLD_START
246 RTLD_START
247 #else
248 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
249 #endif
251 #ifndef VALIDX
252 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
253 + DT_EXTRANUM + DT_VALTAGIDX (tag))
254 #endif
255 #ifndef ADDRIDX
256 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
257 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
258 #endif
260 /* This is the second half of _dl_start (below). It can be inlined safely
261 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
262 references. When the tools don't permit us to avoid using a GOT entry
263 for _dl_rtld_global (no attribute_hidden support), we must make sure
264 this function is not inlined (see below). */
266 #ifdef DONT_USE_BOOTSTRAP_MAP
267 static inline ElfW(Addr) __attribute__ ((always_inline))
268 _dl_start_final (void *arg)
269 #else
270 static ElfW(Addr) __attribute__ ((noinline))
271 _dl_start_final (void *arg, struct dl_start_final_info *info)
272 #endif
274 ElfW(Addr) start_addr;
276 if (HP_TIMING_AVAIL)
278 /* If it hasn't happen yet record the startup time. */
279 if (! HP_TIMING_INLINE)
280 HP_TIMING_NOW (start_time);
281 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
282 else
283 start_time = info->start_time;
284 #endif
286 /* Initialize the timing functions. */
287 HP_TIMING_DIFF_INIT ();
290 /* Transfer data about ourselves to the permanent link_map structure. */
291 #ifndef DONT_USE_BOOTSTRAP_MAP
292 GL(dl_rtld_map).l_addr = info->l.l_addr;
293 GL(dl_rtld_map).l_ld = info->l.l_ld;
294 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
295 sizeof GL(dl_rtld_map).l_info);
296 GL(dl_rtld_map).l_mach = info->l.l_mach;
297 GL(dl_rtld_map).l_relocated = 1;
298 #endif
299 _dl_setup_hash (&GL(dl_rtld_map));
300 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
301 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
302 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
303 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
304 /* Copy the TLS related data if necessary. */
305 #ifndef DONT_USE_BOOTSTRAP_MAP
306 # if USE___THREAD
307 assert (info->l.l_tls_modid != 0);
308 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
309 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
310 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
311 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
312 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
313 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
314 GL(dl_rtld_map).l_tls_modid = 1;
315 # else
316 # if NO_TLS_OFFSET != 0
317 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
318 # endif
319 # endif
321 #endif
323 #if HP_TIMING_AVAIL
324 HP_TIMING_NOW (GL(dl_cpuclock_offset));
325 #endif
327 /* Initialize the stack end variable. */
328 __libc_stack_end = __builtin_frame_address (0);
330 /* Call the OS-dependent function to set up life so we can do things like
331 file access. It will call `dl_main' (below) to do all the real work
332 of the dynamic linker, and then unwind our frame and run the user
333 entry point on the same stack we entered on. */
334 start_addr = _dl_sysdep_start (arg, &dl_main);
336 #ifndef HP_TIMING_NONAVAIL
337 hp_timing_t rtld_total_time;
338 if (HP_TIMING_AVAIL)
340 hp_timing_t end_time;
342 /* Get the current time. */
343 HP_TIMING_NOW (end_time);
345 /* Compute the difference. */
346 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
348 #endif
350 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
352 #ifndef HP_TIMING_NONAVAIL
353 print_statistics (&rtld_total_time);
354 #else
355 print_statistics (NULL);
356 #endif
359 return start_addr;
362 static ElfW(Addr) __attribute_used__ internal_function
363 _dl_start (void *arg)
365 #ifdef DONT_USE_BOOTSTRAP_MAP
366 # define bootstrap_map GL(dl_rtld_map)
367 #else
368 struct dl_start_final_info info;
369 # define bootstrap_map info.l
370 #endif
372 /* This #define produces dynamic linking inline functions for
373 bootstrap relocation instead of general-purpose relocation.
374 Since ld.so must not have any undefined symbols the result
375 is trivial: always the map of ld.so itself. */
376 #define RTLD_BOOTSTRAP
377 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
378 #include "dynamic-link.h"
380 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
381 #ifdef DONT_USE_BOOTSTRAP_MAP
382 HP_TIMING_NOW (start_time);
383 #else
384 HP_TIMING_NOW (info.start_time);
385 #endif
387 /* Partly clean the `bootstrap_map' structure up. Don't use
388 `memset' since it might not be built in or inlined and we cannot
389 make function calls at this point. Use '__builtin_memset' if we
390 know it is available. We do not have to clear the memory if we
391 do not have to use the temporary bootstrap_map. Global variables
392 are initialized to zero by default. */
393 #ifndef DONT_USE_BOOTSTRAP_MAP
394 # ifdef HAVE_BUILTIN_MEMSET
395 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
396 # else
397 for (size_t cnt = 0;
398 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
399 ++cnt)
400 bootstrap_map.l_info[cnt] = 0;
401 # endif
402 # if USE___THREAD
403 bootstrap_map.l_tls_modid = 0;
404 # endif
405 #endif
407 /* Figure out the run-time load address of the dynamic linker itself. */
408 bootstrap_map.l_addr = elf_machine_load_address ();
410 /* Read our own dynamic section and fill in the info array. */
411 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
412 elf_get_dynamic_info (&bootstrap_map, NULL);
414 #if NO_TLS_OFFSET != 0
415 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
416 #endif
418 /* Get the dynamic linker's own program header. First we need the ELF
419 file header. The `_begin' symbol created by the linker script points
420 to it. When we have something like GOTOFF relocs, we can use a plain
421 reference to find the runtime address. Without that, we have to rely
422 on the `l_addr' value, which is not the value we want when prelinked. */
423 #if USE___THREAD
424 dtv_t initdtv[3];
425 ElfW(Ehdr) *ehdr
426 # ifdef DONT_USE_BOOTSTRAP_MAP
427 = (ElfW(Ehdr) *) &_begin;
428 # else
429 # error This will not work with prelink.
430 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
431 # endif
432 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
433 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
434 while (cnt-- > 0)
435 if (phdr[cnt].p_type == PT_TLS)
437 void *tlsblock;
438 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
439 char *p;
441 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
442 bootstrap_map.l_tls_align = phdr[cnt].p_align;
443 if (phdr[cnt].p_align == 0)
444 bootstrap_map.l_tls_firstbyte_offset = 0;
445 else
446 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
447 & (phdr[cnt].p_align - 1));
448 assert (bootstrap_map.l_tls_blocksize != 0);
449 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
450 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
451 + phdr[cnt].p_vaddr);
453 /* We can now allocate the initial TLS block. This can happen
454 on the stack. We'll get the final memory later when we
455 know all about the various objects loaded at startup
456 time. */
457 # if TLS_TCB_AT_TP
458 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
459 TLS_INIT_TCB_ALIGN)
460 + TLS_INIT_TCB_SIZE
461 + max_align);
462 # elif TLS_DTV_AT_TP
463 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
464 bootstrap_map.l_tls_align)
465 + bootstrap_map.l_tls_blocksize
466 + max_align);
467 # else
468 /* In case a model with a different layout for the TCB and DTV
469 is defined add another #elif here and in the following #ifs. */
470 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
471 # endif
472 /* Align the TLS block. */
473 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
474 & ~(max_align - 1));
476 /* Initialize the dtv. [0] is the length, [1] the generation
477 counter. */
478 initdtv[0].counter = 1;
479 initdtv[1].counter = 0;
481 /* Initialize the TLS block. */
482 # if TLS_TCB_AT_TP
483 initdtv[2].pointer = tlsblock;
484 # elif TLS_DTV_AT_TP
485 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
486 bootstrap_map.l_tls_align);
487 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
488 # else
489 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
490 # endif
491 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
492 bootstrap_map.l_tls_initimage_size);
493 # ifdef HAVE_BUILTIN_MEMSET
494 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
495 - bootstrap_map.l_tls_initimage_size));
496 # else
498 size_t remaining = (bootstrap_map.l_tls_blocksize
499 - bootstrap_map.l_tls_initimage_size);
500 while (remaining-- > 0)
501 *p++ = '\0';
503 # endif
505 /* Install the pointer to the dtv. */
507 /* Initialize the thread pointer. */
508 # if TLS_TCB_AT_TP
509 bootstrap_map.l_tls_offset
510 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
512 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
513 initdtv);
515 const char *lossage = TLS_INIT_TP ((char *) tlsblock
516 + bootstrap_map.l_tls_offset, 0);
517 # elif TLS_DTV_AT_TP
518 INSTALL_DTV (tlsblock, initdtv);
519 const char *lossage = TLS_INIT_TP (tlsblock, 0);
520 # else
521 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
522 # endif
523 if (__builtin_expect (lossage != NULL, 0))
524 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
525 lossage);
527 /* So far this is module number one. */
528 bootstrap_map.l_tls_modid = 1;
530 /* There can only be one PT_TLS entry. */
531 break;
533 #endif /* USE___THREAD */
535 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
536 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
537 #endif
539 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
541 /* Relocate ourselves so we can do normal function calls and
542 data access using the global offset table. */
544 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
546 bootstrap_map.l_relocated = 1;
548 /* Please note that we don't allow profiling of this object and
549 therefore need not test whether we have to allocate the array
550 for the relocation results (as done in dl-reloc.c). */
552 /* Now life is sane; we can call functions and access global data.
553 Set up to use the operating system facilities, and find out from
554 the operating system's program loader where to find the program
555 header table in core. Put the rest of _dl_start into a separate
556 function, that way the compiler cannot put accesses to the GOT
557 before ELF_DYNAMIC_RELOCATE. */
559 #ifdef DONT_USE_BOOTSTRAP_MAP
560 ElfW(Addr) entry = _dl_start_final (arg);
561 #else
562 ElfW(Addr) entry = _dl_start_final (arg, &info);
563 #endif
565 #ifndef ELF_MACHINE_START_ADDRESS
566 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
567 #endif
569 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
575 /* Now life is peachy; we can do all normal operations.
576 On to the real work. */
578 /* Some helper functions. */
580 /* Arguments to relocate_doit. */
581 struct relocate_args
583 struct link_map *l;
584 int reloc_mode;
587 struct map_args
589 /* Argument to map_doit. */
590 char *str;
591 struct link_map *loader;
592 int is_preloaded;
593 int mode;
594 /* Return value of map_doit. */
595 struct link_map *map;
598 struct dlmopen_args
600 const char *fname;
601 struct link_map *map;
604 struct lookup_args
606 const char *name;
607 struct link_map *map;
608 void *result;
611 /* Arguments to version_check_doit. */
612 struct version_check_args
614 int doexit;
615 int dotrace;
618 static void
619 relocate_doit (void *a)
621 struct relocate_args *args = (struct relocate_args *) a;
623 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
626 static void
627 map_doit (void *a)
629 struct map_args *args = (struct map_args *) a;
630 args->map = _dl_map_object (args->loader, args->str,
631 args->is_preloaded, lt_library, 0, args->mode,
632 LM_ID_BASE);
635 static void
636 dlmopen_doit (void *a)
638 struct dlmopen_args *args = (struct dlmopen_args *) a;
639 args->map = _dl_open (args->fname, RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT,
640 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
641 __environ);
644 static void
645 lookup_doit (void *a)
647 struct lookup_args *args = (struct lookup_args *) a;
648 const ElfW(Sym) *ref = NULL;
649 args->result = NULL;
650 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
651 args->map->l_local_scope, NULL, 0,
652 DL_LOOKUP_RETURN_NEWEST, NULL);
653 if (ref != NULL)
654 args->result = DL_SYMBOL_ADDRESS (l, ref);
657 static void
658 version_check_doit (void *a)
660 struct version_check_args *args = (struct version_check_args *) a;
661 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
662 args->dotrace) && args->doexit)
663 /* We cannot start the application. Abort now. */
664 _exit (1);
668 static inline struct link_map *
669 find_needed (const char *name)
671 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
672 unsigned int n = scope->r_nlist;
674 while (n-- > 0)
675 if (_dl_name_match_p (name, scope->r_list[n]))
676 return scope->r_list[n];
678 /* Should never happen. */
679 return NULL;
682 static int
683 match_version (const char *string, struct link_map *map)
685 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
686 ElfW(Verdef) *def;
688 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
689 if (map->l_info[VERDEFTAG] == NULL)
690 /* The file has no symbol versioning. */
691 return 0;
693 def = (ElfW(Verdef) *) ((char *) map->l_addr
694 + map->l_info[VERDEFTAG]->d_un.d_ptr);
695 while (1)
697 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
699 /* Compare the version strings. */
700 if (strcmp (string, strtab + aux->vda_name) == 0)
701 /* Bingo! */
702 return 1;
704 /* If no more definitions we failed to find what we want. */
705 if (def->vd_next == 0)
706 break;
708 /* Next definition. */
709 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
712 return 0;
715 static bool tls_init_tp_called;
717 static void *
718 init_tls (void)
720 /* Number of elements in the static TLS block. */
721 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
723 /* Do not do this twice. The audit interface might have required
724 the DTV interfaces to be set up early. */
725 if (GL(dl_initial_dtv) != NULL)
726 return NULL;
728 /* Allocate the array which contains the information about the
729 dtv slots. We allocate a few entries more than needed to
730 avoid the need for reallocation. */
731 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
733 /* Allocate. */
734 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
735 calloc (sizeof (struct dtv_slotinfo_list)
736 + nelem * sizeof (struct dtv_slotinfo), 1);
737 /* No need to check the return value. If memory allocation failed
738 the program would have been terminated. */
740 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
741 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
742 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
744 /* Fill in the information from the loaded modules. No namespace
745 but the base one can be filled at this time. */
746 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
747 int i = 0;
748 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
749 l = l->l_next)
750 if (l->l_tls_blocksize != 0)
752 /* This is a module with TLS data. Store the map reference.
753 The generation counter is zero. */
754 slotinfo[i].map = l;
755 /* slotinfo[i].gen = 0; */
756 ++i;
758 assert (i == GL(dl_tls_max_dtv_idx));
760 /* Compute the TLS offsets for the various blocks. */
761 _dl_determine_tlsoffset ();
763 /* Construct the static TLS block and the dtv for the initial
764 thread. For some platforms this will include allocating memory
765 for the thread descriptor. The memory for the TLS block will
766 never be freed. It should be allocated accordingly. The dtv
767 array can be changed if dynamic loading requires it. */
768 void *tcbp = _dl_allocate_tls_storage ();
769 if (tcbp == NULL)
770 _dl_fatal_printf ("\
771 cannot allocate TLS data structures for initial thread");
773 /* Store for detection of the special case by __tls_get_addr
774 so it knows not to pass this dtv to the normal realloc. */
775 GL(dl_initial_dtv) = GET_DTV (tcbp);
777 /* And finally install it for the main thread. If ld.so itself uses
778 TLS we know the thread pointer was initialized earlier. */
779 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
780 if (__builtin_expect (lossage != NULL, 0))
781 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
782 tls_init_tp_called = true;
784 return tcbp;
787 #ifdef _LIBC_REENTRANT
788 /* _dl_error_catch_tsd points to this for the single-threaded case.
789 It's reset by the thread library for multithreaded programs. */
790 void ** __attribute__ ((const))
791 _dl_initial_error_catch_tsd (void)
793 static void *data;
794 return &data;
796 #endif
799 static unsigned int
800 do_preload (char *fname, struct link_map *main_map, const char *where)
802 const char *objname;
803 const char *err_str = NULL;
804 struct map_args args;
805 bool malloced;
807 args.str = fname;
808 args.loader = main_map;
809 args.is_preloaded = 1;
810 args.mode = 0;
812 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
814 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
815 if (__builtin_expect (err_str != NULL, 0))
817 _dl_error_printf ("\
818 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
819 fname, where);
820 /* No need to call free, this is still before
821 the libc's malloc is used. */
823 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
824 /* It is no duplicate. */
825 return 1;
827 /* Nothing loaded. */
828 return 0;
831 #if defined SHARED && defined _LIBC_REENTRANT \
832 && defined __rtld_lock_default_lock_recursive
833 static void
834 rtld_lock_default_lock_recursive (void *lock)
836 __rtld_lock_default_lock_recursive (lock);
839 static void
840 rtld_lock_default_unlock_recursive (void *lock)
842 __rtld_lock_default_unlock_recursive (lock);
844 #endif
847 static void
848 security_init (void)
850 /* Set up the stack checker's canary. */
851 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
852 #ifdef THREAD_SET_STACK_GUARD
853 THREAD_SET_STACK_GUARD (stack_chk_guard);
854 #else
855 __stack_chk_guard = stack_chk_guard;
856 #endif
858 /* Set up the pointer guard as well, if necessary. */
859 if (GLRO(dl_pointer_guard))
861 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
862 stack_chk_guard);
863 #ifdef THREAD_SET_POINTER_GUARD
864 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
865 #endif
866 __pointer_chk_guard_local = pointer_chk_guard;
869 /* We do not need the _dl_random value anymore. The less
870 information we leave behind, the better, so clear the
871 variable. */
872 _dl_random = NULL;
876 /* The library search path. */
877 static const char *library_path attribute_relro;
878 /* The list preloaded objects. */
879 static const char *preloadlist attribute_relro;
880 /* Nonzero if information about versions has to be printed. */
881 static int version_info attribute_relro;
883 static void
884 dl_main (const ElfW(Phdr) *phdr,
885 ElfW(Word) phnum,
886 ElfW(Addr) *user_entry,
887 ElfW(auxv_t) *auxv)
889 const ElfW(Phdr) *ph;
890 enum mode mode;
891 struct link_map *main_map;
892 size_t file_size;
893 char *file;
894 bool has_interp = false;
895 unsigned int i;
896 bool prelinked = false;
897 bool rtld_is_main = false;
898 #ifndef HP_TIMING_NONAVAIL
899 hp_timing_t start;
900 hp_timing_t stop;
901 hp_timing_t diff;
902 #endif
903 void *tcbp = NULL;
905 #ifdef _LIBC_REENTRANT
906 /* Explicit initialization since the reloc would just be more work. */
907 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
908 #endif
910 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
912 #if defined SHARED && defined _LIBC_REENTRANT \
913 && defined __rtld_lock_default_lock_recursive
914 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
915 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
916 #endif
918 /* The explicit initialization here is cheaper than processing the reloc
919 in the _rtld_local definition's initializer. */
920 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
922 /* Process the environment variable which control the behaviour. */
923 process_envvars (&mode);
925 #ifndef HAVE_INLINED_SYSCALLS
926 /* Set up a flag which tells we are just starting. */
927 INTUSE(_dl_starting_up) = 1;
928 #endif
930 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
932 /* Ho ho. We are not the program interpreter! We are the program
933 itself! This means someone ran ld.so as a command. Well, that
934 might be convenient to do sometimes. We support it by
935 interpreting the args like this:
937 ld.so PROGRAM ARGS...
939 The first argument is the name of a file containing an ELF
940 executable we will load and run with the following arguments.
941 To simplify life here, PROGRAM is searched for using the
942 normal rules for shared objects, rather than $PATH or anything
943 like that. We just load it and use its entry point; we don't
944 pay attention to its PT_INTERP command (we are the interpreter
945 ourselves). This is an easy way to test a new ld.so before
946 installing it. */
947 rtld_is_main = true;
949 /* Note the place where the dynamic linker actually came from. */
950 GL(dl_rtld_map).l_name = rtld_progname;
952 while (_dl_argc > 1)
953 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
955 mode = list;
956 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
958 ++_dl_skip_args;
959 --_dl_argc;
960 ++INTUSE(_dl_argv);
962 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
964 mode = verify;
966 ++_dl_skip_args;
967 --_dl_argc;
968 ++INTUSE(_dl_argv);
970 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
971 && _dl_argc > 2)
973 library_path = INTUSE(_dl_argv)[2];
975 _dl_skip_args += 2;
976 _dl_argc -= 2;
977 INTUSE(_dl_argv) += 2;
979 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
980 && _dl_argc > 2)
982 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
984 _dl_skip_args += 2;
985 _dl_argc -= 2;
986 INTUSE(_dl_argv) += 2;
988 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
990 process_dl_audit (INTUSE(_dl_argv)[2]);
992 _dl_skip_args += 2;
993 _dl_argc -= 2;
994 INTUSE(_dl_argv) += 2;
996 else
997 break;
999 /* If we have no further argument the program was called incorrectly.
1000 Grant the user some education. */
1001 if (_dl_argc < 2)
1002 _dl_fatal_printf ("\
1003 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1004 You have invoked `ld.so', the helper program for shared library executables.\n\
1005 This program usually lives in the file `/lib/ld.so', and special directives\n\
1006 in executable files using ELF shared libraries tell the system's program\n\
1007 loader to load the helper program from this file. This helper program loads\n\
1008 the shared libraries needed by the program executable, prepares the program\n\
1009 to run, and runs it. You may invoke this helper program directly from the\n\
1010 command line to load and run an ELF executable file; this is like executing\n\
1011 that file itself, but always uses this helper program from the file you\n\
1012 specified, instead of the helper program file specified in the executable\n\
1013 file you run. This is mostly of use for maintainers to test new versions\n\
1014 of this helper program; chances are you did not intend to run this program.\n\
1016 --list list all dependencies and how they are resolved\n\
1017 --verify verify that given object really is a dynamically linked\n\
1018 object we can handle\n\
1019 --library-path PATH use given PATH instead of content of the environment\n\
1020 variable LD_LIBRARY_PATH\n\
1021 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1022 in LIST\n\
1023 --audit LIST use objects named in LIST as auditors\n");
1025 ++_dl_skip_args;
1026 --_dl_argc;
1027 ++INTUSE(_dl_argv);
1029 /* The initialization of _dl_stack_flags done below assumes the
1030 executable's PT_GNU_STACK may have been honored by the kernel, and
1031 so a PT_GNU_STACK with PF_X set means the stack started out with
1032 execute permission. However, this is not really true if the
1033 dynamic linker is the executable the kernel loaded. For this
1034 case, we must reinitialize _dl_stack_flags to match the dynamic
1035 linker itself. If the dynamic linker was built with a
1036 PT_GNU_STACK, then the kernel may have loaded us with a
1037 nonexecutable stack that we will have to make executable when we
1038 load the program below unless it has a PT_GNU_STACK indicating
1039 nonexecutable stack is ok. */
1041 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1042 if (ph->p_type == PT_GNU_STACK)
1044 GL(dl_stack_flags) = ph->p_flags;
1045 break;
1048 if (__builtin_expect (mode, normal) == verify)
1050 const char *objname;
1051 const char *err_str = NULL;
1052 struct map_args args;
1053 bool malloced;
1055 args.str = rtld_progname;
1056 args.loader = NULL;
1057 args.is_preloaded = 0;
1058 args.mode = __RTLD_OPENEXEC;
1059 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1060 &args);
1061 if (__builtin_expect (err_str != NULL, 0))
1062 /* We don't free the returned string, the programs stops
1063 anyway. */
1064 _exit (EXIT_FAILURE);
1066 else
1068 HP_TIMING_NOW (start);
1069 _dl_map_object (NULL, rtld_progname, 0, lt_library, 0,
1070 __RTLD_OPENEXEC, LM_ID_BASE);
1071 HP_TIMING_NOW (stop);
1073 HP_TIMING_DIFF (load_time, start, stop);
1076 /* Now the map for the main executable is available. */
1077 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1079 phdr = main_map->l_phdr;
1080 phnum = main_map->l_phnum;
1081 /* We overwrite here a pointer to a malloc()ed string. But since
1082 the malloc() implementation used at this point is the dummy
1083 implementations which has no real free() function it does not
1084 makes sense to free the old string first. */
1085 main_map->l_name = (char *) "";
1086 *user_entry = main_map->l_entry;
1088 #ifdef HAVE_AUX_VECTOR
1089 /* Adjust the on-stack auxiliary vector so that it looks like the
1090 binary was executed directly. */
1091 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1092 switch (av->a_type)
1094 case AT_PHDR:
1095 av->a_un.a_val = (uintptr_t) phdr;
1096 break;
1097 case AT_PHNUM:
1098 av->a_un.a_val = phnum;
1099 break;
1100 case AT_ENTRY:
1101 av->a_un.a_val = *user_entry;
1102 break;
1104 #endif
1106 else
1108 /* Create a link_map for the executable itself.
1109 This will be what dlopen on "" returns. */
1110 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1111 __RTLD_OPENEXEC, LM_ID_BASE);
1112 assert (main_map != NULL);
1113 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1114 main_map->l_phdr = phdr;
1115 main_map->l_phnum = phnum;
1116 main_map->l_entry = *user_entry;
1118 /* At this point we are in a bit of trouble. We would have to
1119 fill in the values for l_dev and l_ino. But in general we
1120 do not know where the file is. We also do not handle AT_EXECFD
1121 even if it would be passed up.
1123 We leave the values here defined to 0. This is normally no
1124 problem as the program code itself is normally no shared
1125 object and therefore cannot be loaded dynamically. Nothing
1126 prevent the use of dynamic binaries and in these situations
1127 we might get problems. We might not be able to find out
1128 whether the object is already loaded. But since there is no
1129 easy way out and because the dynamic binary must also not
1130 have an SONAME we ignore this program for now. If it becomes
1131 a problem we can force people using SONAMEs. */
1133 /* We delay initializing the path structure until we got the dynamic
1134 information for the program. */
1137 main_map->l_map_end = 0;
1138 main_map->l_text_end = 0;
1139 /* Perhaps the executable has no PT_LOAD header entries at all. */
1140 main_map->l_map_start = ~0;
1141 /* And it was opened directly. */
1142 ++main_map->l_direct_opencount;
1144 /* Scan the program header table for the dynamic section. */
1145 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1146 switch (ph->p_type)
1148 case PT_PHDR:
1149 /* Find out the load address. */
1150 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1151 break;
1152 case PT_DYNAMIC:
1153 /* This tells us where to find the dynamic section,
1154 which tells us everything we need to do. */
1155 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1156 break;
1157 case PT_INTERP:
1158 /* This "interpreter segment" was used by the program loader to
1159 find the program interpreter, which is this program itself, the
1160 dynamic linker. We note what name finds us, so that a future
1161 dlopen call or DT_NEEDED entry, for something that wants to link
1162 against the dynamic linker as a shared library, will know that
1163 the shared object is already loaded. */
1164 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1165 + ph->p_vaddr);
1166 /* _dl_rtld_libname.next = NULL; Already zero. */
1167 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1169 /* Ordinarilly, we would get additional names for the loader from
1170 our DT_SONAME. This can't happen if we were actually linked as
1171 a static executable (detect this case when we have no DYNAMIC).
1172 If so, assume the filename component of the interpreter path to
1173 be our SONAME, and add it to our name list. */
1174 if (GL(dl_rtld_map).l_ld == NULL)
1176 const char *p = NULL;
1177 const char *cp = _dl_rtld_libname.name;
1179 /* Find the filename part of the path. */
1180 while (*cp != '\0')
1181 if (*cp++ == '/')
1182 p = cp;
1184 if (p != NULL)
1186 _dl_rtld_libname2.name = p;
1187 /* _dl_rtld_libname2.next = NULL; Already zero. */
1188 _dl_rtld_libname.next = &_dl_rtld_libname2;
1192 has_interp = true;
1193 break;
1194 case PT_LOAD:
1196 ElfW(Addr) mapstart;
1197 ElfW(Addr) allocend;
1199 /* Remember where the main program starts in memory. */
1200 mapstart = (main_map->l_addr
1201 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1202 if (main_map->l_map_start > mapstart)
1203 main_map->l_map_start = mapstart;
1205 /* Also where it ends. */
1206 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1207 if (main_map->l_map_end < allocend)
1208 main_map->l_map_end = allocend;
1209 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1210 main_map->l_text_end = allocend;
1212 break;
1214 case PT_TLS:
1215 if (ph->p_memsz > 0)
1217 /* Note that in the case the dynamic linker we duplicate work
1218 here since we read the PT_TLS entry already in
1219 _dl_start_final. But the result is repeatable so do not
1220 check for this special but unimportant case. */
1221 main_map->l_tls_blocksize = ph->p_memsz;
1222 main_map->l_tls_align = ph->p_align;
1223 if (ph->p_align == 0)
1224 main_map->l_tls_firstbyte_offset = 0;
1225 else
1226 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1227 & (ph->p_align - 1));
1228 main_map->l_tls_initimage_size = ph->p_filesz;
1229 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1231 /* This image gets the ID one. */
1232 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1234 break;
1236 case PT_GNU_STACK:
1237 GL(dl_stack_flags) = ph->p_flags;
1238 break;
1240 case PT_GNU_RELRO:
1241 main_map->l_relro_addr = ph->p_vaddr;
1242 main_map->l_relro_size = ph->p_memsz;
1243 break;
1246 /* Adjust the address of the TLS initialization image in case
1247 the executable is actually an ET_DYN object. */
1248 if (main_map->l_tls_initimage != NULL)
1249 main_map->l_tls_initimage
1250 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1251 if (! main_map->l_map_end)
1252 main_map->l_map_end = ~0;
1253 if (! main_map->l_text_end)
1254 main_map->l_text_end = ~0;
1255 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1257 /* We were invoked directly, so the program might not have a
1258 PT_INTERP. */
1259 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1260 /* _dl_rtld_libname.next = NULL; Already zero. */
1261 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1263 else
1264 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1266 /* If the current libname is different from the SONAME, add the
1267 latter as well. */
1268 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1269 && strcmp (GL(dl_rtld_map).l_libname->name,
1270 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1271 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1273 static struct libname_list newname;
1274 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1275 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1276 newname.next = NULL;
1277 newname.dont_free = 1;
1279 assert (GL(dl_rtld_map).l_libname->next == NULL);
1280 GL(dl_rtld_map).l_libname->next = &newname;
1282 /* The ld.so must be relocated since otherwise loading audit modules
1283 will fail since they reuse the very same ld.so. */
1284 assert (GL(dl_rtld_map).l_relocated);
1286 if (! rtld_is_main)
1288 /* Extract the contents of the dynamic section for easy access. */
1289 elf_get_dynamic_info (main_map, NULL);
1290 /* Set up our cache of pointers into the hash table. */
1291 _dl_setup_hash (main_map);
1294 if (__builtin_expect (mode, normal) == verify)
1296 /* We were called just to verify that this is a dynamic
1297 executable using us as the program interpreter. Exit with an
1298 error if we were not able to load the binary or no interpreter
1299 is specified (i.e., this is no dynamically linked binary. */
1300 if (main_map->l_ld == NULL)
1301 _exit (1);
1303 /* We allow here some platform specific code. */
1304 #ifdef DISTINGUISH_LIB_VERSIONS
1305 DISTINGUISH_LIB_VERSIONS;
1306 #endif
1307 _exit (has_interp ? 0 : 2);
1310 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1311 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1312 /* Set up the data structures for the system-supplied DSO early,
1313 so they can influence _dl_init_paths. */
1314 if (GLRO(dl_sysinfo_dso) != NULL)
1316 /* Do an abridged version of the work _dl_map_object_from_fd would do
1317 to map in the object. It's already mapped and prelinked (and
1318 better be, since it's read-only and so we couldn't relocate it).
1319 We just want our data structures to describe it as if we had just
1320 mapped and relocated it normally. */
1321 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1322 0, LM_ID_BASE);
1323 if (__builtin_expect (l != NULL, 1))
1325 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1327 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1328 + GLRO(dl_sysinfo_dso)->e_phoff);
1329 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1330 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1332 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1333 if (ph->p_type == PT_DYNAMIC)
1335 l->l_ld = (void *) ph->p_vaddr;
1336 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1338 else if (ph->p_type == PT_LOAD)
1340 if (! l->l_addr)
1341 l->l_addr = ph->p_vaddr;
1342 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1343 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1344 if ((ph->p_flags & PF_X)
1345 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1346 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1348 else
1349 /* There must be no TLS segment. */
1350 assert (ph->p_type != PT_TLS);
1352 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1353 l->l_addr = l->l_map_start - l->l_addr;
1354 l->l_map_end += l->l_addr;
1355 l->l_text_end += l->l_addr;
1356 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1357 elf_get_dynamic_info (l, dyn_temp);
1358 _dl_setup_hash (l);
1359 l->l_relocated = 1;
1361 /* Initialize l_local_scope to contain just this map. This allows
1362 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1363 So we create a single entry list pointing to l_real as its only
1364 element */
1365 l->l_local_scope[0]->r_nlist = 1;
1366 l->l_local_scope[0]->r_list = &l->l_real;
1368 /* Now that we have the info handy, use the DSO image's soname
1369 so this object can be looked up by name. Note that we do not
1370 set l_name here. That field gives the file name of the DSO,
1371 and this DSO is not associated with any file. */
1372 if (l->l_info[DT_SONAME] != NULL)
1374 /* Work around a kernel problem. The kernel cannot handle
1375 addresses in the vsyscall DSO pages in writev() calls. */
1376 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1377 + l->l_info[DT_SONAME]->d_un.d_val);
1378 size_t len = strlen (dsoname);
1379 char *copy = malloc (len);
1380 if (copy == NULL)
1381 _dl_fatal_printf ("out of memory\n");
1382 l->l_libname->name = memcpy (copy, dsoname, len);
1385 /* Rearrange the list so this DSO appears after rtld_map. */
1386 assert (l->l_next == NULL);
1387 assert (l->l_prev == main_map);
1388 GL(dl_rtld_map).l_next = l;
1389 l->l_prev = &GL(dl_rtld_map);
1390 first_preload = &l->l_next;
1392 /* We have a prelinked DSO preloaded by the system. */
1393 GLRO(dl_sysinfo_map) = l;
1394 # ifdef NEED_DL_SYSINFO
1395 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1396 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1397 # endif
1400 #endif
1402 #ifdef DL_SYSDEP_OSCHECK
1403 DL_SYSDEP_OSCHECK (dl_fatal);
1404 #endif
1406 /* Initialize the data structures for the search paths for shared
1407 objects. */
1408 _dl_init_paths (library_path);
1410 /* Initialize _r_debug. */
1411 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1412 LM_ID_BASE);
1413 r->r_state = RT_CONSISTENT;
1415 /* Put the link_map for ourselves on the chain so it can be found by
1416 name. Note that at this point the global chain of link maps contains
1417 exactly one element, which is pointed to by dl_loaded. */
1418 if (! GL(dl_rtld_map).l_name)
1419 /* If not invoked directly, the dynamic linker shared object file was
1420 found by the PT_INTERP name. */
1421 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1422 GL(dl_rtld_map).l_type = lt_library;
1423 main_map->l_next = &GL(dl_rtld_map);
1424 GL(dl_rtld_map).l_prev = main_map;
1425 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1426 ++GL(dl_load_adds);
1428 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1429 to not using bias for non-prelinked PIEs and libraries
1430 and using it for executables or prelinked PIEs or libraries. */
1431 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1432 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1434 /* Set up the program header information for the dynamic linker
1435 itself. It is needed in the dl_iterate_phdr() callbacks. */
1436 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1437 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1438 + rtld_ehdr->e_phoff);
1439 GL(dl_rtld_map).l_phdr = rtld_phdr;
1440 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1443 /* PT_GNU_RELRO is usually the last phdr. */
1444 size_t cnt = rtld_ehdr->e_phnum;
1445 while (cnt-- > 0)
1446 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1448 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1449 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1450 break;
1453 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1454 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1455 /* Assign a module ID. Do this before loading any audit modules. */
1456 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1458 /* If we have auditing DSOs to load, do it now. */
1459 if (__builtin_expect (audit_list != NULL, 0))
1461 /* Iterate over all entries in the list. The order is important. */
1462 struct audit_ifaces *last_audit = NULL;
1463 struct audit_list *al = audit_list->next;
1465 /* Since we start using the auditing DSOs right away we need to
1466 initialize the data structures now. */
1467 tcbp = init_tls ();
1469 /* Initialize security features. We need to do it this early
1470 since otherwise the constructors of the audit libraries will
1471 use different values (especially the pointer guard) and will
1472 fail later on. */
1473 security_init ();
1477 int tls_idx = GL(dl_tls_max_dtv_idx);
1479 /* Now it is time to determine the layout of the static TLS
1480 block and allocate it for the initial thread. Note that we
1481 always allocate the static block, we never defer it even if
1482 no DF_STATIC_TLS bit is set. The reason is that we know
1483 glibc will use the static model. */
1484 struct dlmopen_args dlmargs;
1485 dlmargs.fname = al->name;
1486 dlmargs.map = NULL;
1488 const char *objname;
1489 const char *err_str = NULL;
1490 bool malloced;
1491 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1492 &dlmargs);
1493 if (__builtin_expect (err_str != NULL, 0))
1495 not_loaded:
1496 _dl_error_printf ("\
1497 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1498 al->name, err_str);
1499 if (malloced)
1500 free ((char *) err_str);
1502 else
1504 struct lookup_args largs;
1505 largs.name = "la_version";
1506 largs.map = dlmargs.map;
1508 /* Check whether the interface version matches. */
1509 (void) _dl_catch_error (&objname, &err_str, &malloced,
1510 lookup_doit, &largs);
1512 unsigned int (*laversion) (unsigned int);
1513 unsigned int lav;
1514 if (err_str == NULL
1515 && (laversion = largs.result) != NULL
1516 && (lav = laversion (LAV_CURRENT)) > 0
1517 && lav <= LAV_CURRENT)
1519 /* Allocate structure for the callback function pointers.
1520 This call can never fail. */
1521 union
1523 struct audit_ifaces ifaces;
1524 #define naudit_ifaces 8
1525 void (*fptr[naudit_ifaces]) (void);
1526 } *newp = malloc (sizeof (*newp));
1528 /* Names of the auditing interfaces. All in one
1529 long string. */
1530 static const char audit_iface_names[] =
1531 "la_activity\0"
1532 "la_objsearch\0"
1533 "la_objopen\0"
1534 "la_preinit\0"
1535 #if __ELF_NATIVE_CLASS == 32
1536 "la_symbind32\0"
1537 #elif __ELF_NATIVE_CLASS == 64
1538 "la_symbind64\0"
1539 #else
1540 # error "__ELF_NATIVE_CLASS must be defined"
1541 #endif
1542 #define STRING(s) __STRING (s)
1543 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1544 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1545 "la_objclose\0";
1546 unsigned int cnt = 0;
1547 const char *cp = audit_iface_names;
1550 largs.name = cp;
1551 (void) _dl_catch_error (&objname, &err_str, &malloced,
1552 lookup_doit, &largs);
1554 /* Store the pointer. */
1555 if (err_str == NULL && largs.result != NULL)
1557 newp->fptr[cnt] = largs.result;
1559 /* The dynamic linker link map is statically
1560 allocated, initialize the data now. */
1561 GL(dl_rtld_map).l_audit[cnt].cookie
1562 = (intptr_t) &GL(dl_rtld_map);
1564 else
1565 newp->fptr[cnt] = NULL;
1566 ++cnt;
1568 cp = (char *) rawmemchr (cp, '\0') + 1;
1570 while (*cp != '\0');
1571 assert (cnt == naudit_ifaces);
1573 /* Now append the new auditing interface to the list. */
1574 newp->ifaces.next = NULL;
1575 if (last_audit == NULL)
1576 last_audit = GLRO(dl_audit) = &newp->ifaces;
1577 else
1578 last_audit = last_audit->next = &newp->ifaces;
1579 ++GLRO(dl_naudit);
1581 /* Mark the DSO as being used for auditing. */
1582 dlmargs.map->l_auditing = 1;
1584 else
1586 /* We cannot use the DSO, it does not have the
1587 appropriate interfaces or it expects something
1588 more recent. */
1589 #ifndef NDEBUG
1590 Lmid_t ns = dlmargs.map->l_ns;
1591 #endif
1592 _dl_close (dlmargs.map);
1594 /* Make sure the namespace has been cleared entirely. */
1595 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1596 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1598 GL(dl_tls_max_dtv_idx) = tls_idx;
1599 goto not_loaded;
1603 al = al->next;
1605 while (al != audit_list->next);
1607 /* If we have any auditing modules, announce that we already
1608 have two objects loaded. */
1609 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1611 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1613 for (unsigned int outer = 0; outer < 2; ++outer)
1615 struct audit_ifaces *afct = GLRO(dl_audit);
1616 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1618 if (afct->objopen != NULL)
1620 ls[outer]->l_audit[cnt].bindflags
1621 = afct->objopen (ls[outer], LM_ID_BASE,
1622 &ls[outer]->l_audit[cnt].cookie);
1624 ls[outer]->l_audit_any_plt
1625 |= ls[outer]->l_audit[cnt].bindflags != 0;
1628 afct = afct->next;
1634 /* Set up debugging before the debugger is notified for the first time. */
1635 #ifdef ELF_MACHINE_DEBUG_SETUP
1636 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1637 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1638 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1639 #else
1640 if (main_map->l_info[DT_DEBUG] != NULL)
1641 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1642 with the run-time address of the r_debug structure */
1643 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1645 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1646 case you run gdb on the dynamic linker directly. */
1647 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1648 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1649 #endif
1651 /* We start adding objects. */
1652 r->r_state = RT_ADD;
1653 _dl_debug_state ();
1655 /* Auditing checkpoint: we are ready to signal that the initial map
1656 is being constructed. */
1657 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1659 struct audit_ifaces *afct = GLRO(dl_audit);
1660 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1662 if (afct->activity != NULL)
1663 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1665 afct = afct->next;
1669 /* We have two ways to specify objects to preload: via environment
1670 variable and via the file /etc/ld.so.preload. The latter can also
1671 be used when security is enabled. */
1672 assert (*first_preload == NULL);
1673 struct link_map **preloads = NULL;
1674 unsigned int npreloads = 0;
1676 if (__builtin_expect (preloadlist != NULL, 0))
1678 /* The LD_PRELOAD environment variable gives list of libraries
1679 separated by white space or colons that are loaded before the
1680 executable's dependencies and prepended to the global scope
1681 list. If the binary is running setuid all elements
1682 containing a '/' are ignored since it is insecure. */
1683 char *list = strdupa (preloadlist);
1684 char *p;
1686 HP_TIMING_NOW (start);
1688 /* Prevent optimizing strsep. Speed is not important here. */
1689 while ((p = (strsep) (&list, " :")) != NULL)
1690 if (p[0] != '\0'
1691 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1692 || strchr (p, '/') == NULL))
1693 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1695 HP_TIMING_NOW (stop);
1696 HP_TIMING_DIFF (diff, start, stop);
1697 HP_TIMING_ACCUM_NT (load_time, diff);
1700 /* There usually is no ld.so.preload file, it should only be used
1701 for emergencies and testing. So the open call etc should usually
1702 fail. Using access() on a non-existing file is faster than using
1703 open(). So we do this first. If it succeeds we do almost twice
1704 the work but this does not matter, since it is not for production
1705 use. */
1706 static const char preload_file[] = "/etc/ld.so.preload";
1707 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1709 /* Read the contents of the file. */
1710 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1711 PROT_READ | PROT_WRITE);
1712 if (__builtin_expect (file != MAP_FAILED, 0))
1714 /* Parse the file. It contains names of libraries to be loaded,
1715 separated by white spaces or `:'. It may also contain
1716 comments introduced by `#'. */
1717 char *problem;
1718 char *runp;
1719 size_t rest;
1721 /* Eliminate comments. */
1722 runp = file;
1723 rest = file_size;
1724 while (rest > 0)
1726 char *comment = memchr (runp, '#', rest);
1727 if (comment == NULL)
1728 break;
1730 rest -= comment - runp;
1732 *comment = ' ';
1733 while (--rest > 0 && *++comment != '\n');
1736 /* We have one problematic case: if we have a name at the end of
1737 the file without a trailing terminating characters, we cannot
1738 place the \0. Handle the case separately. */
1739 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1740 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1742 problem = &file[file_size];
1743 while (problem > file && problem[-1] != ' '
1744 && problem[-1] != '\t'
1745 && problem[-1] != '\n' && problem[-1] != ':')
1746 --problem;
1748 if (problem > file)
1749 problem[-1] = '\0';
1751 else
1753 problem = NULL;
1754 file[file_size - 1] = '\0';
1757 HP_TIMING_NOW (start);
1759 if (file != problem)
1761 char *p;
1762 runp = file;
1763 while ((p = strsep (&runp, ": \t\n")) != NULL)
1764 if (p[0] != '\0')
1765 npreloads += do_preload (p, main_map, preload_file);
1768 if (problem != NULL)
1770 char *p = strndupa (problem, file_size - (problem - file));
1772 npreloads += do_preload (p, main_map, preload_file);
1775 HP_TIMING_NOW (stop);
1776 HP_TIMING_DIFF (diff, start, stop);
1777 HP_TIMING_ACCUM_NT (load_time, diff);
1779 /* We don't need the file anymore. */
1780 __munmap (file, file_size);
1784 if (__builtin_expect (*first_preload != NULL, 0))
1786 /* Set up PRELOADS with a vector of the preloaded libraries. */
1787 struct link_map *l = *first_preload;
1788 preloads = __alloca (npreloads * sizeof preloads[0]);
1789 i = 0;
1792 preloads[i++] = l;
1793 l = l->l_next;
1794 } while (l);
1795 assert (i == npreloads);
1798 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1799 specified some libraries to load, these are inserted before the actual
1800 dependencies in the executable's searchlist for symbol resolution. */
1801 HP_TIMING_NOW (start);
1802 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1803 HP_TIMING_NOW (stop);
1804 HP_TIMING_DIFF (diff, start, stop);
1805 HP_TIMING_ACCUM_NT (load_time, diff);
1807 /* Mark all objects as being in the global scope. */
1808 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1809 main_map->l_searchlist.r_list[--i]->l_global = 1;
1811 /* Remove _dl_rtld_map from the chain. */
1812 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1813 if (GL(dl_rtld_map).l_next != NULL)
1814 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1816 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1817 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1818 break;
1820 bool rtld_multiple_ref = false;
1821 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1823 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1824 put it back in the list of visible objects. We insert it into the
1825 chain in symbol search order because gdb uses the chain's order as
1826 its symbol search order. */
1827 rtld_multiple_ref = true;
1829 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1830 if (__builtin_expect (mode, normal) == normal)
1832 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1833 ? main_map->l_searchlist.r_list[i + 1]
1834 : NULL);
1835 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1836 if (GLRO(dl_sysinfo_map) != NULL
1837 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1838 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1839 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1840 #endif
1842 else
1843 /* In trace mode there might be an invisible object (which we
1844 could not find) after the previous one in the search list.
1845 In this case it doesn't matter much where we put the
1846 interpreter object, so we just initialize the list pointer so
1847 that the assertion below holds. */
1848 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1850 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1851 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1852 if (GL(dl_rtld_map).l_next != NULL)
1854 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1855 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1859 /* Now let us see whether all libraries are available in the
1860 versions we need. */
1862 struct version_check_args args;
1863 args.doexit = mode == normal;
1864 args.dotrace = mode == trace;
1865 _dl_receive_error (print_missing_version, version_check_doit, &args);
1868 /* We do not initialize any of the TLS functionality unless any of the
1869 initial modules uses TLS. This makes dynamic loading of modules with
1870 TLS impossible, but to support it requires either eagerly doing setup
1871 now or lazily doing it later. Doing it now makes us incompatible with
1872 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1873 used. Trying to do it lazily is too hairy to try when there could be
1874 multiple threads (from a non-TLS-using libpthread). */
1875 bool was_tls_init_tp_called = tls_init_tp_called;
1876 if (tcbp == NULL)
1877 tcbp = init_tls ();
1879 if (__builtin_expect (audit_list == NULL, 1))
1880 /* Initialize security features. But only if we have not done it
1881 earlier. */
1882 security_init ();
1884 if (__builtin_expect (mode, normal) != normal)
1886 /* We were run just to list the shared libraries. It is
1887 important that we do this before real relocation, because the
1888 functions we call below for output may no longer work properly
1889 after relocation. */
1890 struct link_map *l;
1892 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1894 struct r_scope_elem *scope = &main_map->l_searchlist;
1896 for (i = 0; i < scope->r_nlist; i++)
1898 l = scope->r_list [i];
1899 if (l->l_faked)
1901 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1902 continue;
1904 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1905 GLRO(dl_trace_prelink_map) = l;
1906 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1907 l->l_libname->name[0] ? l->l_libname->name
1908 : rtld_progname ?: "<main program>",
1909 l->l_name[0] ? l->l_name
1910 : rtld_progname ?: "<main program>",
1911 (int) sizeof l->l_map_start * 2,
1912 (size_t) l->l_map_start,
1913 (int) sizeof l->l_addr * 2,
1914 (size_t) l->l_addr);
1916 if (l->l_tls_modid)
1917 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1918 (int) sizeof l->l_tls_offset * 2,
1919 (size_t) l->l_tls_offset);
1920 else
1921 _dl_printf ("\n");
1924 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1926 /* Look through the dependencies of the main executable
1927 and determine which of them is not actually
1928 required. */
1929 struct link_map *l = main_map;
1931 /* Relocate the main executable. */
1932 struct relocate_args args = { .l = l,
1933 .reloc_mode = (GLRO(dl_lazy)
1934 ? RTLD_LAZY : 0) };
1935 _dl_receive_error (print_unresolved, relocate_doit, &args);
1937 /* This loop depends on the dependencies of the executable to
1938 correspond in number and order to the DT_NEEDED entries. */
1939 ElfW(Dyn) *dyn = main_map->l_ld;
1940 bool first = true;
1941 while (dyn->d_tag != DT_NULL)
1943 if (dyn->d_tag == DT_NEEDED)
1945 l = l->l_next;
1947 if (!l->l_used)
1949 if (first)
1951 _dl_printf ("Unused direct dependencies:\n");
1952 first = false;
1955 _dl_printf ("\t%s\n", l->l_name);
1959 ++dyn;
1962 _exit (first != true);
1964 else if (! main_map->l_info[DT_NEEDED])
1965 _dl_printf ("\tstatically linked\n");
1966 else
1968 for (l = main_map->l_next; l; l = l->l_next)
1969 if (l->l_faked)
1970 /* The library was not found. */
1971 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1972 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1973 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1974 (int) sizeof l->l_map_start * 2,
1975 (size_t) l->l_map_start);
1976 else
1977 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1978 l->l_name, (int) sizeof l->l_map_start * 2,
1979 (size_t) l->l_map_start);
1982 if (__builtin_expect (mode, trace) != trace)
1983 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1985 const ElfW(Sym) *ref = NULL;
1986 ElfW(Addr) loadbase;
1987 lookup_t result;
1989 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
1990 &ref, main_map->l_scope,
1991 NULL, ELF_RTYPE_CLASS_PLT,
1992 DL_LOOKUP_ADD_DEPENDENCY, NULL);
1994 loadbase = LOOKUP_VALUE_ADDRESS (result);
1996 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
1997 INTUSE(_dl_argv)[i],
1998 (int) sizeof ref->st_value * 2,
1999 (size_t) ref->st_value,
2000 (int) sizeof loadbase * 2, (size_t) loadbase);
2002 else
2004 /* If LD_WARN is set, warn about undefined symbols. */
2005 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2007 /* We have to do symbol dependency testing. */
2008 struct relocate_args args;
2009 struct link_map *l;
2011 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2013 l = main_map;
2014 while (l->l_next != NULL)
2015 l = l->l_next;
2018 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2020 args.l = l;
2021 _dl_receive_error (print_unresolved, relocate_doit,
2022 &args);
2024 l = l->l_prev;
2026 while (l != NULL);
2028 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2029 && rtld_multiple_ref)
2031 /* Mark the link map as not yet relocated again. */
2032 GL(dl_rtld_map).l_relocated = 0;
2033 _dl_relocate_object (&GL(dl_rtld_map),
2034 main_map->l_scope, 0, 0);
2037 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2038 if (version_info)
2040 /* Print more information. This means here, print information
2041 about the versions needed. */
2042 int first = 1;
2043 struct link_map *map;
2045 for (map = main_map; map != NULL; map = map->l_next)
2047 const char *strtab;
2048 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2049 ElfW(Verneed) *ent;
2051 if (dyn == NULL)
2052 continue;
2054 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2055 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2057 if (first)
2059 _dl_printf ("\n\tVersion information:\n");
2060 first = 0;
2063 _dl_printf ("\t%s:\n",
2064 map->l_name[0] ? map->l_name : rtld_progname);
2066 while (1)
2068 ElfW(Vernaux) *aux;
2069 struct link_map *needed;
2071 needed = find_needed (strtab + ent->vn_file);
2072 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2074 while (1)
2076 const char *fname = NULL;
2078 if (needed != NULL
2079 && match_version (strtab + aux->vna_name,
2080 needed))
2081 fname = needed->l_name;
2083 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2084 strtab + ent->vn_file,
2085 strtab + aux->vna_name,
2086 aux->vna_flags & VER_FLG_WEAK
2087 ? "[WEAK] " : "",
2088 fname ?: "not found");
2090 if (aux->vna_next == 0)
2091 /* No more symbols. */
2092 break;
2094 /* Next symbol. */
2095 aux = (ElfW(Vernaux) *) ((char *) aux
2096 + aux->vna_next);
2099 if (ent->vn_next == 0)
2100 /* No more dependencies. */
2101 break;
2103 /* Next dependency. */
2104 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2110 _exit (0);
2113 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2114 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2115 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2117 ElfW(Lib) *liblist, *liblistend;
2118 struct link_map **r_list, **r_listend, *l;
2119 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2121 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2122 liblist = (ElfW(Lib) *)
2123 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2124 liblistend = (ElfW(Lib) *)
2125 ((char *) liblist +
2126 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2127 r_list = main_map->l_searchlist.r_list;
2128 r_listend = r_list + main_map->l_searchlist.r_nlist;
2130 for (; r_list < r_listend && liblist < liblistend; r_list++)
2132 l = *r_list;
2134 if (l == main_map)
2135 continue;
2137 /* If the library is not mapped where it should, fail. */
2138 if (l->l_addr)
2139 break;
2141 /* Next, check if checksum matches. */
2142 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2143 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2144 != liblist->l_checksum)
2145 break;
2147 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2148 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2149 != liblist->l_time_stamp)
2150 break;
2152 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2153 break;
2155 ++liblist;
2159 if (r_list == r_listend && liblist == liblistend)
2160 prelinked = true;
2162 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2163 _dl_debug_printf ("\nprelink checking: %s\n",
2164 prelinked ? "ok" : "failed");
2168 /* Now set up the variable which helps the assembler startup code. */
2169 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2171 /* Save the information about the original global scope list since
2172 we need it in the memory handling later. */
2173 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2175 if (prelinked)
2177 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2179 ElfW(Rela) *conflict, *conflictend;
2180 #ifndef HP_TIMING_NONAVAIL
2181 hp_timing_t start;
2182 hp_timing_t stop;
2183 #endif
2185 HP_TIMING_NOW (start);
2186 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2187 conflict = (ElfW(Rela) *)
2188 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2189 conflictend = (ElfW(Rela) *)
2190 ((char *) conflict
2191 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2192 _dl_resolve_conflicts (main_map, conflict, conflictend);
2193 HP_TIMING_NOW (stop);
2194 HP_TIMING_DIFF (relocate_time, start, stop);
2198 /* Mark all the objects so we know they have been already relocated. */
2199 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2201 l->l_relocated = 1;
2202 if (l->l_relro_size)
2203 _dl_protect_relro (l);
2205 /* Add object to slot information data if necessasy. */
2206 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2207 _dl_add_to_slotinfo (l);
2210 else
2212 /* Now we have all the objects loaded. Relocate them all except for
2213 the dynamic linker itself. We do this in reverse order so that copy
2214 relocs of earlier objects overwrite the data written by later
2215 objects. We do not re-relocate the dynamic linker itself in this
2216 loop because that could result in the GOT entries for functions we
2217 call being changed, and that would break us. It is safe to relocate
2218 the dynamic linker out of order because it has no copy relocs (we
2219 know that because it is self-contained). */
2221 int consider_profiling = GLRO(dl_profile) != NULL;
2222 #ifndef HP_TIMING_NONAVAIL
2223 hp_timing_t start;
2224 hp_timing_t stop;
2225 #endif
2227 /* If we are profiling we also must do lazy reloaction. */
2228 GLRO(dl_lazy) |= consider_profiling;
2230 struct link_map *l = main_map;
2231 while (l->l_next)
2232 l = l->l_next;
2234 HP_TIMING_NOW (start);
2237 /* While we are at it, help the memory handling a bit. We have to
2238 mark some data structures as allocated with the fake malloc()
2239 implementation in ld.so. */
2240 struct libname_list *lnp = l->l_libname->next;
2242 while (__builtin_expect (lnp != NULL, 0))
2244 lnp->dont_free = 1;
2245 lnp = lnp->next;
2248 if (l != &GL(dl_rtld_map))
2249 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2250 consider_profiling);
2252 /* Add object to slot information data if necessasy. */
2253 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2254 _dl_add_to_slotinfo (l);
2256 l = l->l_prev;
2258 while (l);
2259 HP_TIMING_NOW (stop);
2261 HP_TIMING_DIFF (relocate_time, start, stop);
2263 /* Now enable profiling if needed. Like the previous call,
2264 this has to go here because the calls it makes should use the
2265 rtld versions of the functions (particularly calloc()), but it
2266 needs to have _dl_profile_map set up by the relocator. */
2267 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2268 /* We must prepare the profiling. */
2269 _dl_start_profile ();
2272 #ifndef NONTLS_INIT_TP
2273 # define NONTLS_INIT_TP do { } while (0)
2274 #endif
2276 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2277 ++GL(dl_tls_generation);
2279 /* Now that we have completed relocation, the initializer data
2280 for the TLS blocks has its final values and we can copy them
2281 into the main thread's TLS area, which we allocated above. */
2282 _dl_allocate_tls_init (tcbp);
2284 /* And finally install it for the main thread. If ld.so itself uses
2285 TLS we know the thread pointer was initialized earlier. */
2286 if (! tls_init_tp_called)
2288 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2289 if (__builtin_expect (lossage != NULL, 0))
2290 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2291 lossage);
2294 /* Remember the last search directory added at startup, now that
2295 malloc will no longer be the one from dl-minimal.c. */
2296 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2298 if (! prelinked && rtld_multiple_ref)
2300 /* There was an explicit ref to the dynamic linker as a shared lib.
2301 Re-relocate ourselves with user-controlled symbol definitions.
2303 We must do this after TLS initialization in case after this
2304 re-relocation, we might call a user-supplied function
2305 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2307 #ifndef HP_TIMING_NONAVAIL
2308 hp_timing_t start;
2309 hp_timing_t stop;
2310 hp_timing_t add;
2311 #endif
2313 HP_TIMING_NOW (start);
2314 /* Mark the link map as not yet relocated again. */
2315 GL(dl_rtld_map).l_relocated = 0;
2316 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2317 HP_TIMING_NOW (stop);
2318 HP_TIMING_DIFF (add, start, stop);
2319 HP_TIMING_ACCUM_NT (relocate_time, add);
2322 /* Do any necessary cleanups for the startup OS interface code.
2323 We do these now so that no calls are made after rtld re-relocation
2324 which might be resolved to different functions than we expect.
2325 We cannot do this before relocating the other objects because
2326 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2327 _dl_sysdep_start_cleanup ();
2329 #ifdef SHARED
2330 /* Auditing checkpoint: we have added all objects. */
2331 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2333 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2334 /* Do not call the functions for any auditing object. */
2335 if (head->l_auditing == 0)
2337 struct audit_ifaces *afct = GLRO(dl_audit);
2338 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2340 if (afct->activity != NULL)
2341 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2343 afct = afct->next;
2347 #endif
2349 /* Notify the debugger all new objects are now ready to go. We must re-get
2350 the address since by now the variable might be in another object. */
2351 r = _dl_debug_initialize (0, LM_ID_BASE);
2352 r->r_state = RT_CONSISTENT;
2353 _dl_debug_state ();
2355 #ifndef MAP_COPY
2356 /* We must munmap() the cache file. */
2357 _dl_unload_cache ();
2358 #endif
2360 /* Once we return, _dl_sysdep_start will invoke
2361 the DT_INIT functions and then *USER_ENTRY. */
2364 /* This is a little helper function for resolving symbols while
2365 tracing the binary. */
2366 static void
2367 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2368 const char *errstring)
2370 if (objname[0] == '\0')
2371 objname = rtld_progname ?: "<main program>";
2372 _dl_error_printf ("%s (%s)\n", errstring, objname);
2375 /* This is a little helper function for resolving symbols while
2376 tracing the binary. */
2377 static void
2378 print_missing_version (int errcode __attribute__ ((unused)),
2379 const char *objname, const char *errstring)
2381 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2382 objname, errstring);
2385 /* Nonzero if any of the debugging options is enabled. */
2386 static int any_debug attribute_relro;
2388 /* Process the string given as the parameter which explains which debugging
2389 options are enabled. */
2390 static void
2391 process_dl_debug (const char *dl_debug)
2393 /* When adding new entries make sure that the maximal length of a name
2394 is correctly handled in the LD_DEBUG_HELP code below. */
2395 static const struct
2397 unsigned char len;
2398 const char name[10];
2399 const char helptext[41];
2400 unsigned short int mask;
2401 } debopts[] =
2403 #define LEN_AND_STR(str) sizeof (str) - 1, str
2404 { LEN_AND_STR ("libs"), "display library search paths",
2405 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2406 { LEN_AND_STR ("reloc"), "display relocation processing",
2407 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2408 { LEN_AND_STR ("files"), "display progress for input file",
2409 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2410 { LEN_AND_STR ("symbols"), "display symbol table processing",
2411 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2412 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2413 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2414 { LEN_AND_STR ("versions"), "display version dependencies",
2415 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2416 { LEN_AND_STR ("all"), "all previous options combined",
2417 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2418 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2419 { LEN_AND_STR ("statistics"), "display relocation statistics",
2420 DL_DEBUG_STATISTICS },
2421 { LEN_AND_STR ("unused"), "determined unused DSOs",
2422 DL_DEBUG_UNUSED },
2423 { LEN_AND_STR ("help"), "display this help message and exit",
2424 DL_DEBUG_HELP },
2426 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2428 /* Skip separating white spaces and commas. */
2429 while (*dl_debug != '\0')
2431 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2433 size_t cnt;
2434 size_t len = 1;
2436 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2437 && dl_debug[len] != ',' && dl_debug[len] != ':')
2438 ++len;
2440 for (cnt = 0; cnt < ndebopts; ++cnt)
2441 if (debopts[cnt].len == len
2442 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2444 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2445 any_debug = 1;
2446 break;
2449 if (cnt == ndebopts)
2451 /* Display a warning and skip everything until next
2452 separator. */
2453 char *copy = strndupa (dl_debug, len);
2454 _dl_error_printf ("\
2455 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2458 dl_debug += len;
2459 continue;
2462 ++dl_debug;
2465 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2467 size_t cnt;
2469 _dl_printf ("\
2470 Valid options for the LD_DEBUG environment variable are:\n\n");
2472 for (cnt = 0; cnt < ndebopts; ++cnt)
2473 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2474 " " + debopts[cnt].len - 3,
2475 debopts[cnt].helptext);
2477 _dl_printf ("\n\
2478 To direct the debugging output into a file instead of standard output\n\
2479 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2480 _exit (0);
2484 static void
2485 process_dl_audit (char *str)
2487 /* The parameter is a colon separated list of DSO names. */
2488 char *p;
2490 while ((p = (strsep) (&str, ":")) != NULL)
2491 if (p[0] != '\0'
2492 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2493 || strchr (p, '/') == NULL))
2495 /* This is using the local malloc, not the system malloc. The
2496 memory can never be freed. */
2497 struct audit_list *newp = malloc (sizeof (*newp));
2498 newp->name = p;
2500 if (audit_list == NULL)
2501 audit_list = newp->next = newp;
2502 else
2504 newp->next = audit_list->next;
2505 audit_list = audit_list->next = newp;
2510 /* Process all environments variables the dynamic linker must recognize.
2511 Since all of them start with `LD_' we are a bit smarter while finding
2512 all the entries. */
2513 extern char **_environ attribute_hidden;
2516 static void
2517 process_envvars (enum mode *modep)
2519 char **runp = _environ;
2520 char *envline;
2521 enum mode mode = normal;
2522 char *debug_output = NULL;
2524 /* This is the default place for profiling data file. */
2525 GLRO(dl_profile_output)
2526 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2528 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2530 size_t len = 0;
2532 while (envline[len] != '\0' && envline[len] != '=')
2533 ++len;
2535 if (envline[len] != '=')
2536 /* This is a "LD_" variable at the end of the string without
2537 a '=' character. Ignore it since otherwise we will access
2538 invalid memory below. */
2539 continue;
2541 switch (len)
2543 case 4:
2544 /* Warning level, verbose or not. */
2545 if (memcmp (envline, "WARN", 4) == 0)
2546 GLRO(dl_verbose) = envline[5] != '\0';
2547 break;
2549 case 5:
2550 /* Debugging of the dynamic linker? */
2551 if (memcmp (envline, "DEBUG", 5) == 0)
2553 process_dl_debug (&envline[6]);
2554 break;
2556 if (memcmp (envline, "AUDIT", 5) == 0)
2557 process_dl_audit (&envline[6]);
2558 break;
2560 case 7:
2561 /* Print information about versions. */
2562 if (memcmp (envline, "VERBOSE", 7) == 0)
2564 version_info = envline[8] != '\0';
2565 break;
2568 /* List of objects to be preloaded. */
2569 if (memcmp (envline, "PRELOAD", 7) == 0)
2571 preloadlist = &envline[8];
2572 break;
2575 /* Which shared object shall be profiled. */
2576 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2577 GLRO(dl_profile) = &envline[8];
2578 break;
2580 case 8:
2581 /* Do we bind early? */
2582 if (memcmp (envline, "BIND_NOW", 8) == 0)
2584 GLRO(dl_lazy) = envline[9] == '\0';
2585 break;
2587 if (memcmp (envline, "BIND_NOT", 8) == 0)
2588 GLRO(dl_bind_not) = envline[9] != '\0';
2589 break;
2591 case 9:
2592 /* Test whether we want to see the content of the auxiliary
2593 array passed up from the kernel. */
2594 if (!INTUSE(__libc_enable_secure)
2595 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2596 _dl_show_auxv ();
2597 break;
2599 case 10:
2600 /* Mask for the important hardware capabilities. */
2601 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2602 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2603 0, 0);
2604 break;
2606 case 11:
2607 /* Path where the binary is found. */
2608 if (!INTUSE(__libc_enable_secure)
2609 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2610 GLRO(dl_origin_path) = &envline[12];
2611 break;
2613 case 12:
2614 /* The library search path. */
2615 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2617 library_path = &envline[13];
2618 break;
2621 /* Where to place the profiling data file. */
2622 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2624 debug_output = &envline[13];
2625 break;
2628 if (!INTUSE(__libc_enable_secure)
2629 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2630 GLRO(dl_dynamic_weak) = 1;
2631 break;
2633 case 13:
2634 /* We might have some extra environment variable with length 13
2635 to handle. */
2636 #ifdef EXTRA_LD_ENVVARS_13
2637 EXTRA_LD_ENVVARS_13
2638 #endif
2639 if (!INTUSE(__libc_enable_secure)
2640 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2642 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2643 break;
2646 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2647 GLRO(dl_pointer_guard) = envline[14] != '0';
2648 break;
2650 case 14:
2651 /* Where to place the profiling data file. */
2652 if (!INTUSE(__libc_enable_secure)
2653 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2654 && envline[15] != '\0')
2655 GLRO(dl_profile_output) = &envline[15];
2656 break;
2658 case 16:
2659 /* The mode of the dynamic linker can be set. */
2660 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2662 mode = trace;
2663 GLRO(dl_verbose) = 1;
2664 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2665 GLRO(dl_trace_prelink) = &envline[17];
2667 break;
2669 case 20:
2670 /* The mode of the dynamic linker can be set. */
2671 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2672 mode = trace;
2673 break;
2675 /* We might have some extra environment variable to handle. This
2676 is tricky due to the pre-processing of the length of the name
2677 in the switch statement here. The code here assumes that added
2678 environment variables have a different length. */
2679 #ifdef EXTRA_LD_ENVVARS
2680 EXTRA_LD_ENVVARS
2681 #endif
2685 /* The caller wants this information. */
2686 *modep = mode;
2688 /* Extra security for SUID binaries. Remove all dangerous environment
2689 variables. */
2690 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2692 static const char unsecure_envvars[] =
2693 #ifdef EXTRA_UNSECURE_ENVVARS
2694 EXTRA_UNSECURE_ENVVARS
2695 #endif
2696 UNSECURE_ENVVARS;
2697 const char *nextp;
2699 nextp = unsecure_envvars;
2702 unsetenv (nextp);
2703 /* We could use rawmemchr but this need not be fast. */
2704 nextp = (char *) (strchr) (nextp, '\0') + 1;
2706 while (*nextp != '\0');
2708 if (__access ("/etc/suid-debug", F_OK) != 0)
2710 unsetenv ("MALLOC_CHECK_");
2711 GLRO(dl_debug_mask) = 0;
2714 if (mode != normal)
2715 _exit (5);
2717 /* If we have to run the dynamic linker in debugging mode and the
2718 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2719 messages to this file. */
2720 else if (any_debug && debug_output != NULL)
2722 #ifdef O_NOFOLLOW
2723 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2724 #else
2725 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2726 #endif
2727 size_t name_len = strlen (debug_output);
2728 char buf[name_len + 12];
2729 char *startp;
2731 buf[name_len + 11] = '\0';
2732 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2733 *--startp = '.';
2734 startp = memcpy (startp - name_len, debug_output, name_len);
2736 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2737 if (GLRO(dl_debug_fd) == -1)
2738 /* We use standard output if opening the file failed. */
2739 GLRO(dl_debug_fd) = STDOUT_FILENO;
2744 /* Print the various times we collected. */
2745 static void
2746 __attribute ((noinline))
2747 print_statistics (hp_timing_t *rtld_total_timep)
2749 #ifndef HP_TIMING_NONAVAIL
2750 char buf[200];
2751 char *cp;
2752 char *wp;
2754 /* Total time rtld used. */
2755 if (HP_TIMING_AVAIL)
2757 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2758 _dl_debug_printf ("\nruntime linker statistics:\n"
2759 " total startup time in dynamic loader: %s\n", buf);
2761 /* Print relocation statistics. */
2762 char pbuf[30];
2763 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2764 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2765 pbuf + sizeof (pbuf), 10, 0);
2766 wp = pbuf;
2767 switch (pbuf + sizeof (pbuf) - cp)
2769 case 3:
2770 *wp++ = *cp++;
2771 case 2:
2772 *wp++ = *cp++;
2773 case 1:
2774 *wp++ = '.';
2775 *wp++ = *cp++;
2777 *wp = '\0';
2778 _dl_debug_printf ("\
2779 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2781 #endif
2783 unsigned long int num_relative_relocations = 0;
2784 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2786 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2787 continue;
2789 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2791 for (unsigned int i = 0; i < scope->r_nlist; i++)
2793 struct link_map *l = scope->r_list [i];
2795 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2796 num_relative_relocations
2797 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2798 #ifndef ELF_MACHINE_REL_RELATIVE
2799 /* Relative relocations are processed on these architectures if
2800 library is loaded to different address than p_vaddr or
2801 if not prelinked. */
2802 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2803 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2804 #else
2805 /* On e.g. IA-64 or Alpha, relative relocations are processed
2806 only if library is loaded to different address than p_vaddr. */
2807 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2808 #endif
2809 num_relative_relocations
2810 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2814 _dl_debug_printf (" number of relocations: %lu\n"
2815 " number of relocations from cache: %lu\n"
2816 " number of relative relocations: %lu\n",
2817 GL(dl_num_relocations),
2818 GL(dl_num_cache_relocations),
2819 num_relative_relocations);
2821 #ifndef HP_TIMING_NONAVAIL
2822 /* Time spend while loading the object and the dependencies. */
2823 if (HP_TIMING_AVAIL)
2825 char pbuf[30];
2826 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2827 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2828 pbuf + sizeof (pbuf), 10, 0);
2829 wp = pbuf;
2830 switch (pbuf + sizeof (pbuf) - cp)
2832 case 3:
2833 *wp++ = *cp++;
2834 case 2:
2835 *wp++ = *cp++;
2836 case 1:
2837 *wp++ = '.';
2838 *wp++ = *cp++;
2840 *wp = '\0';
2841 _dl_debug_printf ("\
2842 time needed to load objects: %s (%s%%)\n",
2843 buf, pbuf);
2845 #endif