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1 /* Run time dynamic linker.
2 Copyright (C) 1995-2010, 2011 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
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.
14
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. */
19
20 #include <errno.h>
21 #include <dlfcn.h>
22 #include <fcntl.h>
23 #include <stdbool.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 #include <sys/mman.h>
28 #include <sys/param.h>
29 #include <sys/stat.h>
30 #include <ldsodefs.h>
31 #include <stdio-common/_itoa.h>
32 #include <entry.h>
33 #include <fpu_control.h>
34 #include <hp-timing.h>
35 #include <bits/libc-lock.h>
36 #include "dynamic-link.h"
37 #include <dl-librecon.h>
38 #include <unsecvars.h>
39 #include <dl-cache.h>
40 #include <dl-osinfo.h>
41 #include <dl-procinfo.h>
42 #include <tls.h>
43 #include <stackinfo.h>
44
45 #include <assert.h>
46
47 /* Avoid PLT use for our local calls at startup. */
48 extern __typeof (__mempcpy) __mempcpy attribute_hidden;
49
50 /* GCC has mental blocks about _exit. */
51 extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
52 #define _exit exit_internal
53
54 /* Helper function to handle errors while resolving symbols. */
55 static void print_unresolved (int errcode, const char *objname,
56 const char *errsting);
57
58 /* Helper function to handle errors when a version is missing. */
59 static void print_missing_version (int errcode, const char *objname,
60 const char *errsting);
61
62 /* Print the various times we collected. */
63 static void print_statistics (hp_timing_t *total_timep);
64
65 /* Add audit objects. */
66 static void process_dl_audit (char *str);
67
68 /* This is a list of all the modes the dynamic loader can be in. */
69 enum mode { normal, list, verify, trace };
70
71 /* Process all environments variables the dynamic linker must recognize.
72 Since all of them start with `LD_' we are a bit smarter while finding
73 all the entries. */
74 static void process_envvars (enum mode *modep);
75
76 #ifdef DL_ARGV_NOT_RELRO
77 int _dl_argc attribute_hidden;
78 char **_dl_argv = NULL;
79 /* Nonzero if we were run directly. */
80 unsigned int _dl_skip_args attribute_hidden;
81 #else
82 int _dl_argc attribute_relro attribute_hidden;
83 char **_dl_argv attribute_relro = NULL;
84 unsigned int _dl_skip_args attribute_relro attribute_hidden;
85 #endif
86 INTDEF(_dl_argv)
87
88 #ifndef THREAD_SET_STACK_GUARD
89 /* Only exported for architectures that don't store the stack guard canary
90 in thread local area. */
91 uintptr_t __stack_chk_guard attribute_relro;
92 #endif
93
94 /* Only exported for architectures that don't store the pointer guard
95 value in thread local area. */
96 uintptr_t __pointer_chk_guard_local
97 attribute_relro attribute_hidden __attribute__ ((nocommon));
98 #ifndef THREAD_SET_POINTER_GUARD
99 strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
100 #endif
101
102
103 /* List of auditing DSOs. */
104 static struct audit_list
105 {
106 const char *name;
107 struct audit_list *next;
108 } *audit_list;
109
110 #ifndef HAVE_INLINED_SYSCALLS
111 /* Set nonzero during loading and initialization of executable and
112 libraries, cleared before the executable's entry point runs. This
113 must not be initialized to nonzero, because the unused dynamic
114 linker loaded in for libc.so's "ld.so.1" dep will provide the
115 definition seen by libc.so's initializer; that value must be zero,
116 and will be since that dynamic linker's _dl_start and dl_main will
117 never be called. */
118 int _dl_starting_up = 0;
119 INTVARDEF(_dl_starting_up)
120 #endif
121
122 /* This is the structure which defines all variables global to ld.so
123 (except those which cannot be added for some reason). */
124 struct rtld_global _rtld_global =
125 {
126 /* Generally the default presumption without further information is an
127 * executable stack but this is not true for all platforms. */
128 ._dl_stack_flags = DEFAULT_STACK_PERMS,
129 #ifdef _LIBC_REENTRANT
130 ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
131 ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
132 #endif
133 ._dl_nns = 1,
134 ._dl_ns =
135 {
136 [LM_ID_BASE] = { ._ns_unique_sym_table
137 = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
138 }
139 };
140 /* If we would use strong_alias here the compiler would see a
141 non-hidden definition. This would undo the effect of the previous
142 declaration. So spell out was strong_alias does plus add the
143 visibility attribute. */
144 extern struct rtld_global _rtld_local
145 __attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
146
147
148 /* This variable is similar to _rtld_local, but all values are
149 read-only after relocation. */
150 struct rtld_global_ro _rtld_global_ro attribute_relro =
151 {
152 /* Get architecture specific initializer. */
153 #include <dl-procinfo.c>
154 #ifdef NEED_DL_SYSINFO
155 ._dl_sysinfo = DL_SYSINFO_DEFAULT,
156 #endif
157 ._dl_debug_fd = STDERR_FILENO,
158 ._dl_use_load_bias = -2,
159 ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
160 ._dl_hwcap_mask = HWCAP_IMPORTANT,
161 ._dl_lazy = 1,
162 ._dl_fpu_control = _FPU_DEFAULT,
163 ._dl_pointer_guard = 1,
164
165 /* Function pointers. */
166 ._dl_debug_printf = _dl_debug_printf,
167 ._dl_catch_error = _dl_catch_error,
168 ._dl_signal_error = _dl_signal_error,
169 ._dl_mcount = _dl_mcount_internal,
170 ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
171 ._dl_check_caller = _dl_check_caller,
172 ._dl_open = _dl_open,
173 ._dl_close = _dl_close,
174 ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
175 #ifdef HAVE_DL_DISCOVER_OSVERSION
176 ._dl_discover_osversion = _dl_discover_osversion
177 #endif
178 };
179 /* If we would use strong_alias here the compiler would see a
180 non-hidden definition. This would undo the effect of the previous
181 declaration. So spell out was strong_alias does plus add the
182 visibility attribute. */
183 extern struct rtld_global_ro _rtld_local_ro
184 __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
185
186
187 static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
188 ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
189
190 /* These two variables cannot be moved into .data.rel.ro. */
191 static struct libname_list _dl_rtld_libname;
192 static struct libname_list _dl_rtld_libname2;
193
194 /* We expect less than a second for relocation. */
195 #ifdef HP_SMALL_TIMING_AVAIL
196 # undef HP_TIMING_AVAIL
197 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
198 #endif
199
200 /* Variable for statistics. */
201 #ifndef HP_TIMING_NONAVAIL
202 static hp_timing_t relocate_time;
203 static hp_timing_t load_time attribute_relro;
204 static hp_timing_t start_time attribute_relro;
205 #endif
206
207 /* Additional definitions needed by TLS initialization. */
208 #ifdef TLS_INIT_HELPER
209 TLS_INIT_HELPER
210 #endif
211
212 /* Helper function for syscall implementation. */
213 #ifdef DL_SYSINFO_IMPLEMENTATION
214 DL_SYSINFO_IMPLEMENTATION
215 #endif
216
217 /* Before ld.so is relocated we must not access variables which need
218 relocations. This means variables which are exported. Variables
219 declared as static are fine. If we can mark a variable hidden this
220 is fine, too. The latter is important here. We can avoid setting
221 up a temporary link map for ld.so if we can mark _rtld_global as
222 hidden. */
223 #ifdef PI_STATIC_AND_HIDDEN
224 # define DONT_USE_BOOTSTRAP_MAP 1
225 #endif
226
227 #ifdef DONT_USE_BOOTSTRAP_MAP
228 static ElfW(Addr) _dl_start_final (void *arg);
229 #else
230 struct dl_start_final_info
231 {
232 struct link_map l;
233 #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
234 hp_timing_t start_time;
235 #endif
236 };
237 static ElfW(Addr) _dl_start_final (void *arg,
238 struct dl_start_final_info *info);
239 #endif
240
241 /* These defined magically in the linker script. */
242 extern char _begin[] attribute_hidden;
243 extern char _etext[] attribute_hidden;
244 extern char _end[] attribute_hidden;
245
246
247 #ifdef RTLD_START
248 RTLD_START
249 #else
250 # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
251 #endif
252
253 #ifndef VALIDX
254 # define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
255 + DT_EXTRANUM + DT_VALTAGIDX (tag))
256 #endif
257 #ifndef ADDRIDX
258 # define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
259 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
260 #endif
261
262 /* This is the second half of _dl_start (below). It can be inlined safely
263 under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
264 references. When the tools don't permit us to avoid using a GOT entry
265 for _dl_rtld_global (no attribute_hidden support), we must make sure
266 this function is not inlined (see below). */
267
268 #ifdef DONT_USE_BOOTSTRAP_MAP
269 static inline ElfW(Addr) __attribute__ ((always_inline))
270 _dl_start_final (void *arg)
271 #else
272 static ElfW(Addr) __attribute__ ((noinline))
273 _dl_start_final (void *arg, struct dl_start_final_info *info)
274 #endif
275 {
276 ElfW(Addr) start_addr;
277
278 if (HP_TIMING_AVAIL)
279 {
280 /* If it hasn't happen yet record the startup time. */
281 if (! HP_TIMING_INLINE)
282 HP_TIMING_NOW (start_time);
283 #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
284 else
285 start_time = info->start_time;
286 #endif
287
288 /* Initialize the timing functions. */
289 HP_TIMING_DIFF_INIT ();
290 }
291
292 /* Transfer data about ourselves to the permanent link_map structure. */
293 #ifndef DONT_USE_BOOTSTRAP_MAP
294 GL(dl_rtld_map).l_addr = info->l.l_addr;
295 GL(dl_rtld_map).l_ld = info->l.l_ld;
296 memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
297 sizeof GL(dl_rtld_map).l_info);
298 GL(dl_rtld_map).l_mach = info->l.l_mach;
299 GL(dl_rtld_map).l_relocated = 1;
300 #endif
301 _dl_setup_hash (&GL(dl_rtld_map));
302 GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
303 GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
304 GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
305 GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
306 /* Copy the TLS related data if necessary. */
307 #ifndef DONT_USE_BOOTSTRAP_MAP
308 # if USE___THREAD
309 assert (info->l.l_tls_modid != 0);
310 GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
311 GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
312 GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
313 GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
314 GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
315 GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
316 GL(dl_rtld_map).l_tls_modid = 1;
317 # else
318 # if NO_TLS_OFFSET != 0
319 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
320 # endif
321 # endif
322
323 #endif
324
325 #if HP_TIMING_AVAIL
326 HP_TIMING_NOW (GL(dl_cpuclock_offset));
327 #endif
328
329 /* Initialize the stack end variable. */
330 __libc_stack_end = __builtin_frame_address (0);
331
332 /* Call the OS-dependent function to set up life so we can do things like
333 file access. It will call `dl_main' (below) to do all the real work
334 of the dynamic linker, and then unwind our frame and run the user
335 entry point on the same stack we entered on. */
336 start_addr = _dl_sysdep_start (arg, &dl_main);
337
338 #ifndef HP_TIMING_NONAVAIL
339 hp_timing_t rtld_total_time;
340 if (HP_TIMING_AVAIL)
341 {
342 hp_timing_t end_time;
343
344 /* Get the current time. */
345 HP_TIMING_NOW (end_time);
346
347 /* Compute the difference. */
348 HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
349 }
350 #endif
351
352 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
353 {
354 #ifndef HP_TIMING_NONAVAIL
355 print_statistics (&rtld_total_time);
356 #else
357 print_statistics (NULL);
358 #endif
359 }
360
361 return start_addr;
362 }
363
364 static ElfW(Addr) __attribute_used__ internal_function
365 _dl_start (void *arg)
366 {
367 #ifdef DONT_USE_BOOTSTRAP_MAP
368 # define bootstrap_map GL(dl_rtld_map)
369 #else
370 struct dl_start_final_info info;
371 # define bootstrap_map info.l
372 #endif
373
374 /* This #define produces dynamic linking inline functions for
375 bootstrap relocation instead of general-purpose relocation.
376 Since ld.so must not have any undefined symbols the result
377 is trivial: always the map of ld.so itself. */
378 #define RTLD_BOOTSTRAP
379 #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
380 #include "dynamic-link.h"
381
382 if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
383 #ifdef DONT_USE_BOOTSTRAP_MAP
384 HP_TIMING_NOW (start_time);
385 #else
386 HP_TIMING_NOW (info.start_time);
387 #endif
388
389 /* Partly clean the `bootstrap_map' structure up. Don't use
390 `memset' since it might not be built in or inlined and we cannot
391 make function calls at this point. Use '__builtin_memset' if we
392 know it is available. We do not have to clear the memory if we
393 do not have to use the temporary bootstrap_map. Global variables
394 are initialized to zero by default. */
395 #ifndef DONT_USE_BOOTSTRAP_MAP
396 # ifdef HAVE_BUILTIN_MEMSET
397 __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
398 # else
399 for (size_t cnt = 0;
400 cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
401 ++cnt)
402 bootstrap_map.l_info[cnt] = 0;
403 # endif
404 # if USE___THREAD
405 bootstrap_map.l_tls_modid = 0;
406 # endif
407 #endif
408
409 /* Figure out the run-time load address of the dynamic linker itself. */
410 bootstrap_map.l_addr = elf_machine_load_address ();
411
412 /* Read our own dynamic section and fill in the info array. */
413 bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
414 elf_get_dynamic_info (&bootstrap_map, NULL);
415
416 #if NO_TLS_OFFSET != 0
417 bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
418 #endif
419
420 /* Get the dynamic linker's own program header. First we need the ELF
421 file header. The `_begin' symbol created by the linker script points
422 to it. When we have something like GOTOFF relocs, we can use a plain
423 reference to find the runtime address. Without that, we have to rely
424 on the `l_addr' value, which is not the value we want when prelinked. */
425 #if USE___THREAD
426 dtv_t initdtv[3];
427 ElfW(Ehdr) *ehdr
428 # ifdef DONT_USE_BOOTSTRAP_MAP
429 = (ElfW(Ehdr) *) &_begin;
430 # else
431 # error This will not work with prelink.
432 = (ElfW(Ehdr) *) bootstrap_map.l_addr;
433 # endif
434 ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
435 size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */
436 while (cnt-- > 0)
437 if (phdr[cnt].p_type == PT_TLS)
438 {
439 void *tlsblock;
440 size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
441 char *p;
442
443 bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
444 bootstrap_map.l_tls_align = phdr[cnt].p_align;
445 if (phdr[cnt].p_align == 0)
446 bootstrap_map.l_tls_firstbyte_offset = 0;
447 else
448 bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
449 & (phdr[cnt].p_align - 1));
450 assert (bootstrap_map.l_tls_blocksize != 0);
451 bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
452 bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
453 + phdr[cnt].p_vaddr);
454
455 /* We can now allocate the initial TLS block. This can happen
456 on the stack. We'll get the final memory later when we
457 know all about the various objects loaded at startup
458 time. */
459 # if TLS_TCB_AT_TP
460 tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
461 TLS_INIT_TCB_ALIGN)
462 + TLS_INIT_TCB_SIZE
463 + max_align);
464 # elif TLS_DTV_AT_TP
465 tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
466 bootstrap_map.l_tls_align)
467 + bootstrap_map.l_tls_blocksize
468 + max_align);
469 # else
470 /* In case a model with a different layout for the TCB and DTV
471 is defined add another #elif here and in the following #ifs. */
472 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
473 # endif
474 /* Align the TLS block. */
475 tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
476 & ~(max_align - 1));
477
478 /* Initialize the dtv. [0] is the length, [1] the generation
479 counter. */
480 initdtv[0].counter = 1;
481 initdtv[1].counter = 0;
482
483 /* Initialize the TLS block. */
484 # if TLS_TCB_AT_TP
485 initdtv[2].pointer = tlsblock;
486 # elif TLS_DTV_AT_TP
487 bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
488 bootstrap_map.l_tls_align);
489 initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
490 # else
491 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
492 # endif
493 p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
494 bootstrap_map.l_tls_initimage_size);
495 # ifdef HAVE_BUILTIN_MEMSET
496 __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
497 - bootstrap_map.l_tls_initimage_size));
498 # else
499 {
500 size_t remaining = (bootstrap_map.l_tls_blocksize
501 - bootstrap_map.l_tls_initimage_size);
502 while (remaining-- > 0)
503 *p++ = '\0';
504 }
505 # endif
506
507 /* Install the pointer to the dtv. */
508
509 /* Initialize the thread pointer. */
510 # if TLS_TCB_AT_TP
511 bootstrap_map.l_tls_offset
512 = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
513
514 INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
515 initdtv);
516
517 const char *lossage = TLS_INIT_TP ((char *) tlsblock
518 + bootstrap_map.l_tls_offset, 0);
519 # elif TLS_DTV_AT_TP
520 INSTALL_DTV (tlsblock, initdtv);
521 const char *lossage = TLS_INIT_TP (tlsblock, 0);
522 # else
523 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
524 # endif
525 if (__builtin_expect (lossage != NULL, 0))
526 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
527 lossage);
528
529 /* So far this is module number one. */
530 bootstrap_map.l_tls_modid = 1;
531
532 /* There can only be one PT_TLS entry. */
533 break;
534 }
535 #endif /* USE___THREAD */
536
537 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
538 ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
539 #endif
540
541 if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
542 {
543 /* Relocate ourselves so we can do normal function calls and
544 data access using the global offset table. */
545
546 ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
547 }
548 bootstrap_map.l_relocated = 1;
549
550 /* Please note that we don't allow profiling of this object and
551 therefore need not test whether we have to allocate the array
552 for the relocation results (as done in dl-reloc.c). */
553
554 /* Now life is sane; we can call functions and access global data.
555 Set up to use the operating system facilities, and find out from
556 the operating system's program loader where to find the program
557 header table in core. Put the rest of _dl_start into a separate
558 function, that way the compiler cannot put accesses to the GOT
559 before ELF_DYNAMIC_RELOCATE. */
560 {
561 #ifdef DONT_USE_BOOTSTRAP_MAP
562 ElfW(Addr) entry = _dl_start_final (arg);
563 #else
564 ElfW(Addr) entry = _dl_start_final (arg, &info);
565 #endif
566
567 #ifndef ELF_MACHINE_START_ADDRESS
568 # define ELF_MACHINE_START_ADDRESS(map, start) (start)
569 #endif
570
571 return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
572 }
573 }
574
575
576
577 /* Now life is peachy; we can do all normal operations.
578 On to the real work. */
579
580 /* Some helper functions. */
581
582 /* Arguments to relocate_doit. */
583 struct relocate_args
584 {
585 struct link_map *l;
586 int reloc_mode;
587 };
588
589 struct map_args
590 {
591 /* Argument to map_doit. */
592 char *str;
593 struct link_map *loader;
594 int mode;
595 /* Return value of map_doit. */
596 struct link_map *map;
597 };
598
599 struct dlmopen_args
600 {
601 const char *fname;
602 struct link_map *map;
603 };
604
605 struct lookup_args
606 {
607 const char *name;
608 struct link_map *map;
609 void *result;
610 };
611
612 /* Arguments to version_check_doit. */
613 struct version_check_args
614 {
615 int doexit;
616 int dotrace;
617 };
618
619 static void
620 relocate_doit (void *a)
621 {
622 struct relocate_args *args = (struct relocate_args *) a;
623
624 _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
625 }
626
627 static void
628 map_doit (void *a)
629 {
630 struct map_args *args = (struct map_args *) a;
631 args->map = _dl_map_object (args->loader, args->str, lt_library, 0,
632 args->mode, LM_ID_BASE);
633 }
634
635 static void
636 dlmopen_doit (void *a)
637 {
638 struct dlmopen_args *args = (struct dlmopen_args *) a;
639 args->map = _dl_open (args->fname,
640 (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
641 | __RTLD_SECURE),
642 dl_main, LM_ID_NEWLM, _dl_argc, INTUSE(_dl_argv),
643 __environ);
644 }
645
646 static void
647 lookup_doit (void *a)
648 {
649 struct lookup_args *args = (struct lookup_args *) a;
650 const ElfW(Sym) *ref = NULL;
651 args->result = NULL;
652 lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
653 args->map->l_local_scope, NULL, 0,
654 DL_LOOKUP_RETURN_NEWEST, NULL);
655 if (ref != NULL)
656 args->result = DL_SYMBOL_ADDRESS (l, ref);
657 }
658
659 static void
660 version_check_doit (void *a)
661 {
662 struct version_check_args *args = (struct version_check_args *) a;
663 if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
664 args->dotrace) && args->doexit)
665 /* We cannot start the application. Abort now. */
666 _exit (1);
667 }
668
669
670 static inline struct link_map *
671 find_needed (const char *name)
672 {
673 struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
674 unsigned int n = scope->r_nlist;
675
676 while (n-- > 0)
677 if (_dl_name_match_p (name, scope->r_list[n]))
678 return scope->r_list[n];
679
680 /* Should never happen. */
681 return NULL;
682 }
683
684 static int
685 match_version (const char *string, struct link_map *map)
686 {
687 const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
688 ElfW(Verdef) *def;
689
690 #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
691 if (map->l_info[VERDEFTAG] == NULL)
692 /* The file has no symbol versioning. */
693 return 0;
694
695 def = (ElfW(Verdef) *) ((char *) map->l_addr
696 + map->l_info[VERDEFTAG]->d_un.d_ptr);
697 while (1)
698 {
699 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
700
701 /* Compare the version strings. */
702 if (strcmp (string, strtab + aux->vda_name) == 0)
703 /* Bingo! */
704 return 1;
705
706 /* If no more definitions we failed to find what we want. */
707 if (def->vd_next == 0)
708 break;
709
710 /* Next definition. */
711 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
712 }
713
714 return 0;
715 }
716
717 static bool tls_init_tp_called;
718
719 static void *
720 init_tls (void)
721 {
722 /* Number of elements in the static TLS block. */
723 GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
724
725 /* Do not do this twice. The audit interface might have required
726 the DTV interfaces to be set up early. */
727 if (GL(dl_initial_dtv) != NULL)
728 return NULL;
729
730 /* Allocate the array which contains the information about the
731 dtv slots. We allocate a few entries more than needed to
732 avoid the need for reallocation. */
733 size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
734
735 /* Allocate. */
736 GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
737 calloc (sizeof (struct dtv_slotinfo_list)
738 + nelem * sizeof (struct dtv_slotinfo), 1);
739 /* No need to check the return value. If memory allocation failed
740 the program would have been terminated. */
741
742 struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
743 GL(dl_tls_dtv_slotinfo_list)->len = nelem;
744 GL(dl_tls_dtv_slotinfo_list)->next = NULL;
745
746 /* Fill in the information from the loaded modules. No namespace
747 but the base one can be filled at this time. */
748 assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
749 int i = 0;
750 for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
751 l = l->l_next)
752 if (l->l_tls_blocksize != 0)
753 {
754 /* This is a module with TLS data. Store the map reference.
755 The generation counter is zero. */
756 slotinfo[i].map = l;
757 /* slotinfo[i].gen = 0; */
758 ++i;
759 }
760 assert (i == GL(dl_tls_max_dtv_idx));
761
762 /* Compute the TLS offsets for the various blocks. */
763 _dl_determine_tlsoffset ();
764
765 /* Construct the static TLS block and the dtv for the initial
766 thread. For some platforms this will include allocating memory
767 for the thread descriptor. The memory for the TLS block will
768 never be freed. It should be allocated accordingly. The dtv
769 array can be changed if dynamic loading requires it. */
770 void *tcbp = _dl_allocate_tls_storage ();
771 if (tcbp == NULL)
772 _dl_fatal_printf ("\
773 cannot allocate TLS data structures for initial thread");
774
775 /* Store for detection of the special case by __tls_get_addr
776 so it knows not to pass this dtv to the normal realloc. */
777 GL(dl_initial_dtv) = GET_DTV (tcbp);
778
779 /* And finally install it for the main thread. If ld.so itself uses
780 TLS we know the thread pointer was initialized earlier. */
781 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
782 if (__builtin_expect (lossage != NULL, 0))
783 _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
784 tls_init_tp_called = true;
785
786 return tcbp;
787 }
788
789 #ifdef _LIBC_REENTRANT
790 /* _dl_error_catch_tsd points to this for the single-threaded case.
791 It's reset by the thread library for multithreaded programs. */
792 void ** __attribute__ ((const))
793 _dl_initial_error_catch_tsd (void)
794 {
795 static void *data;
796 return &data;
797 }
798 #endif
799
800
801 static unsigned int
802 do_preload (char *fname, struct link_map *main_map, const char *where)
803 {
804 const char *objname;
805 const char *err_str = NULL;
806 struct map_args args;
807 bool malloced;
808
809 args.str = fname;
810 args.loader = main_map;
811 args.mode = __RTLD_SECURE;
812
813 unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
814
815 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
816 if (__builtin_expect (err_str != NULL, 0))
817 {
818 _dl_error_printf ("\
819 ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n",
820 fname, where);
821 /* No need to call free, this is still before
822 the libc's malloc is used. */
823 }
824 else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
825 /* It is no duplicate. */
826 return 1;
827
828 /* Nothing loaded. */
829 return 0;
830 }
831
832 #if defined SHARED && defined _LIBC_REENTRANT \
833 && defined __rtld_lock_default_lock_recursive
834 static void
835 rtld_lock_default_lock_recursive (void *lock)
836 {
837 __rtld_lock_default_lock_recursive (lock);
838 }
839
840 static void
841 rtld_lock_default_unlock_recursive (void *lock)
842 {
843 __rtld_lock_default_unlock_recursive (lock);
844 }
845 #endif
846
847
848 static void
849 security_init (void)
850 {
851 /* Set up the stack checker's canary. */
852 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
853 #ifdef THREAD_SET_STACK_GUARD
854 THREAD_SET_STACK_GUARD (stack_chk_guard);
855 #else
856 __stack_chk_guard = stack_chk_guard;
857 #endif
858
859 /* Set up the pointer guard as well, if necessary. */
860 if (GLRO(dl_pointer_guard))
861 {
862 uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,
863 stack_chk_guard);
864 #ifdef THREAD_SET_POINTER_GUARD
865 THREAD_SET_POINTER_GUARD (pointer_chk_guard);
866 #endif
867 __pointer_chk_guard_local = pointer_chk_guard;
868 }
869
870 /* We do not need the _dl_random value anymore. The less
871 information we leave behind, the better, so clear the
872 variable. */
873 _dl_random = NULL;
874 }
875
876
877 /* The library search path. */
878 static const char *library_path attribute_relro;
879 /* The list preloaded objects. */
880 static const char *preloadlist attribute_relro;
881 /* Nonzero if information about versions has to be printed. */
882 static int version_info attribute_relro;
883
884 static void
885 dl_main (const ElfW(Phdr) *phdr,
886 ElfW(Word) phnum,
887 ElfW(Addr) *user_entry,
888 ElfW(auxv_t) *auxv)
889 {
890 const ElfW(Phdr) *ph;
891 enum mode mode;
892 struct link_map *main_map;
893 size_t file_size;
894 char *file;
895 bool has_interp = false;
896 unsigned int i;
897 bool prelinked = false;
898 bool rtld_is_main = false;
899 #ifndef HP_TIMING_NONAVAIL
900 hp_timing_t start;
901 hp_timing_t stop;
902 hp_timing_t diff;
903 #endif
904 void *tcbp = NULL;
905
906 #ifdef _LIBC_REENTRANT
907 /* Explicit initialization since the reloc would just be more work. */
908 GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd;
909 #endif
910
911 GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
912
913 #if defined SHARED && defined _LIBC_REENTRANT \
914 && defined __rtld_lock_default_lock_recursive
915 GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
916 GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
917 #endif
918
919 /* The explicit initialization here is cheaper than processing the reloc
920 in the _rtld_local definition's initializer. */
921 GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
922
923 /* Process the environment variable which control the behaviour. */
924 process_envvars (&mode);
925
926 #ifndef HAVE_INLINED_SYSCALLS
927 /* Set up a flag which tells we are just starting. */
928 INTUSE(_dl_starting_up) = 1;
929 #endif
930
931 if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
932 {
933 /* Ho ho. We are not the program interpreter! We are the program
934 itself! This means someone ran ld.so as a command. Well, that
935 might be convenient to do sometimes. We support it by
936 interpreting the args like this:
937
938 ld.so PROGRAM ARGS...
939
940 The first argument is the name of a file containing an ELF
941 executable we will load and run with the following arguments.
942 To simplify life here, PROGRAM is searched for using the
943 normal rules for shared objects, rather than $PATH or anything
944 like that. We just load it and use its entry point; we don't
945 pay attention to its PT_INTERP command (we are the interpreter
946 ourselves). This is an easy way to test a new ld.so before
947 installing it. */
948 rtld_is_main = true;
949
950 /* Note the place where the dynamic linker actually came from. */
951 GL(dl_rtld_map).l_name = rtld_progname;
952
953 while (_dl_argc > 1)
954 if (! strcmp (INTUSE(_dl_argv)[1], "--list"))
955 {
956 mode = list;
957 GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
958
959 ++_dl_skip_args;
960 --_dl_argc;
961 ++INTUSE(_dl_argv);
962 }
963 else if (! strcmp (INTUSE(_dl_argv)[1], "--verify"))
964 {
965 mode = verify;
966
967 ++_dl_skip_args;
968 --_dl_argc;
969 ++INTUSE(_dl_argv);
970 }
971 else if (! strcmp (INTUSE(_dl_argv)[1], "--library-path")
972 && _dl_argc > 2)
973 {
974 library_path = INTUSE(_dl_argv)[2];
975
976 _dl_skip_args += 2;
977 _dl_argc -= 2;
978 INTUSE(_dl_argv) += 2;
979 }
980 else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath")
981 && _dl_argc > 2)
982 {
983 GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2];
984
985 _dl_skip_args += 2;
986 _dl_argc -= 2;
987 INTUSE(_dl_argv) += 2;
988 }
989 else if (! strcmp (INTUSE(_dl_argv)[1], "--audit") && _dl_argc > 2)
990 {
991 process_dl_audit (INTUSE(_dl_argv)[2]);
992
993 _dl_skip_args += 2;
994 _dl_argc -= 2;
995 INTUSE(_dl_argv) += 2;
996 }
997 else
998 break;
999
1000 /* If we have no further argument the program was called incorrectly.
1001 Grant the user some education. */
1002 if (_dl_argc < 2)
1003 _dl_fatal_printf ("\
1004 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
1005 You have invoked `ld.so', the helper program for shared library executables.\n\
1006 This program usually lives in the file `/lib/ld.so', and special directives\n\
1007 in executable files using ELF shared libraries tell the system's program\n\
1008 loader to load the helper program from this file. This helper program loads\n\
1009 the shared libraries needed by the program executable, prepares the program\n\
1010 to run, and runs it. You may invoke this helper program directly from the\n\
1011 command line to load and run an ELF executable file; this is like executing\n\
1012 that file itself, but always uses this helper program from the file you\n\
1013 specified, instead of the helper program file specified in the executable\n\
1014 file you run. This is mostly of use for maintainers to test new versions\n\
1015 of this helper program; chances are you did not intend to run this program.\n\
1016 \n\
1017 --list list all dependencies and how they are resolved\n\
1018 --verify verify that given object really is a dynamically linked\n\
1019 object we can handle\n\
1020 --library-path PATH use given PATH instead of content of the environment\n\
1021 variable LD_LIBRARY_PATH\n\
1022 --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
1023 in LIST\n\
1024 --audit LIST use objects named in LIST as auditors\n");
1025
1026 ++_dl_skip_args;
1027 --_dl_argc;
1028 ++INTUSE(_dl_argv);
1029
1030 /* The initialization of _dl_stack_flags done below assumes the
1031 executable's PT_GNU_STACK may have been honored by the kernel, and
1032 so a PT_GNU_STACK with PF_X set means the stack started out with
1033 execute permission. However, this is not really true if the
1034 dynamic linker is the executable the kernel loaded. For this
1035 case, we must reinitialize _dl_stack_flags to match the dynamic
1036 linker itself. If the dynamic linker was built with a
1037 PT_GNU_STACK, then the kernel may have loaded us with a
1038 nonexecutable stack that we will have to make executable when we
1039 load the program below unless it has a PT_GNU_STACK indicating
1040 nonexecutable stack is ok. */
1041
1042 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1043 if (ph->p_type == PT_GNU_STACK)
1044 {
1045 GL(dl_stack_flags) = ph->p_flags;
1046 break;
1047 }
1048
1049 if (__builtin_expect (mode, normal) == verify)
1050 {
1051 const char *objname;
1052 const char *err_str = NULL;
1053 struct map_args args;
1054 bool malloced;
1055
1056 args.str = rtld_progname;
1057 args.loader = NULL;
1058 args.mode = __RTLD_OPENEXEC;
1059 (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1060 &args);
1061 if (__builtin_expect (err_str != NULL, 0))
1062 /* We don't free the returned string, the programs stops
1063 anyway. */
1064 _exit (EXIT_FAILURE);
1065 }
1066 else
1067 {
1068 HP_TIMING_NOW (start);
1069 _dl_map_object (NULL, rtld_progname, lt_library, 0,
1070 __RTLD_OPENEXEC, LM_ID_BASE);
1071 HP_TIMING_NOW (stop);
1072
1073 HP_TIMING_DIFF (load_time, start, stop);
1074 }
1075
1076 /* Now the map for the main executable is available. */
1077 main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1078
1079 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1080 && main_map->l_info[DT_SONAME] != NULL
1081 && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1082 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val,
1083 (const char *) D_PTR (main_map, l_info[DT_STRTAB])
1084 + main_map->l_info[DT_SONAME]->d_un.d_val) == 0)
1085 _dl_fatal_printf ("loader cannot load itself\n");
1086
1087 phdr = main_map->l_phdr;
1088 phnum = main_map->l_phnum;
1089 /* We overwrite here a pointer to a malloc()ed string. But since
1090 the malloc() implementation used at this point is the dummy
1091 implementations which has no real free() function it does not
1092 makes sense to free the old string first. */
1093 main_map->l_name = (char *) "";
1094 *user_entry = main_map->l_entry;
1095
1096 #ifdef HAVE_AUX_VECTOR
1097 /* Adjust the on-stack auxiliary vector so that it looks like the
1098 binary was executed directly. */
1099 for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1100 switch (av->a_type)
1101 {
1102 case AT_PHDR:
1103 av->a_un.a_val = (uintptr_t) phdr;
1104 break;
1105 case AT_PHNUM:
1106 av->a_un.a_val = phnum;
1107 break;
1108 case AT_ENTRY:
1109 av->a_un.a_val = *user_entry;
1110 break;
1111 }
1112 #endif
1113 }
1114 else
1115 {
1116 /* Create a link_map for the executable itself.
1117 This will be what dlopen on "" returns. */
1118 main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1119 __RTLD_OPENEXEC, LM_ID_BASE);
1120 assert (main_map != NULL);
1121 main_map->l_phdr = phdr;
1122 main_map->l_phnum = phnum;
1123 main_map->l_entry = *user_entry;
1124
1125 /* Even though the link map is not yet fully initialized we can add
1126 it to the map list since there are no possible users running yet. */
1127 _dl_add_to_namespace_list (main_map, LM_ID_BASE);
1128 assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1129
1130 /* At this point we are in a bit of trouble. We would have to
1131 fill in the values for l_dev and l_ino. But in general we
1132 do not know where the file is. We also do not handle AT_EXECFD
1133 even if it would be passed up.
1134
1135 We leave the values here defined to 0. This is normally no
1136 problem as the program code itself is normally no shared
1137 object and therefore cannot be loaded dynamically. Nothing
1138 prevent the use of dynamic binaries and in these situations
1139 we might get problems. We might not be able to find out
1140 whether the object is already loaded. But since there is no
1141 easy way out and because the dynamic binary must also not
1142 have an SONAME we ignore this program for now. If it becomes
1143 a problem we can force people using SONAMEs. */
1144
1145 /* We delay initializing the path structure until we got the dynamic
1146 information for the program. */
1147 }
1148
1149 main_map->l_map_end = 0;
1150 main_map->l_text_end = 0;
1151 /* Perhaps the executable has no PT_LOAD header entries at all. */
1152 main_map->l_map_start = ~0;
1153 /* And it was opened directly. */
1154 ++main_map->l_direct_opencount;
1155
1156 /* Scan the program header table for the dynamic section. */
1157 for (ph = phdr; ph < &phdr[phnum]; ++ph)
1158 switch (ph->p_type)
1159 {
1160 case PT_PHDR:
1161 /* Find out the load address. */
1162 main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1163 break;
1164 case PT_DYNAMIC:
1165 /* This tells us where to find the dynamic section,
1166 which tells us everything we need to do. */
1167 main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1168 break;
1169 case PT_INTERP:
1170 /* This "interpreter segment" was used by the program loader to
1171 find the program interpreter, which is this program itself, the
1172 dynamic linker. We note what name finds us, so that a future
1173 dlopen call or DT_NEEDED entry, for something that wants to link
1174 against the dynamic linker as a shared library, will know that
1175 the shared object is already loaded. */
1176 _dl_rtld_libname.name = ((const char *) main_map->l_addr
1177 + ph->p_vaddr);
1178 /* _dl_rtld_libname.next = NULL; Already zero. */
1179 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1180
1181 /* Ordinarilly, we would get additional names for the loader from
1182 our DT_SONAME. This can't happen if we were actually linked as
1183 a static executable (detect this case when we have no DYNAMIC).
1184 If so, assume the filename component of the interpreter path to
1185 be our SONAME, and add it to our name list. */
1186 if (GL(dl_rtld_map).l_ld == NULL)
1187 {
1188 const char *p = NULL;
1189 const char *cp = _dl_rtld_libname.name;
1190
1191 /* Find the filename part of the path. */
1192 while (*cp != '\0')
1193 if (*cp++ == '/')
1194 p = cp;
1195
1196 if (p != NULL)
1197 {
1198 _dl_rtld_libname2.name = p;
1199 /* _dl_rtld_libname2.next = NULL; Already zero. */
1200 _dl_rtld_libname.next = &_dl_rtld_libname2;
1201 }
1202 }
1203
1204 has_interp = true;
1205 break;
1206 case PT_LOAD:
1207 {
1208 ElfW(Addr) mapstart;
1209 ElfW(Addr) allocend;
1210
1211 /* Remember where the main program starts in memory. */
1212 mapstart = (main_map->l_addr
1213 + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
1214 if (main_map->l_map_start > mapstart)
1215 main_map->l_map_start = mapstart;
1216
1217 /* Also where it ends. */
1218 allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1219 if (main_map->l_map_end < allocend)
1220 main_map->l_map_end = allocend;
1221 if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1222 main_map->l_text_end = allocend;
1223 }
1224 break;
1225
1226 case PT_TLS:
1227 if (ph->p_memsz > 0)
1228 {
1229 /* Note that in the case the dynamic linker we duplicate work
1230 here since we read the PT_TLS entry already in
1231 _dl_start_final. But the result is repeatable so do not
1232 check for this special but unimportant case. */
1233 main_map->l_tls_blocksize = ph->p_memsz;
1234 main_map->l_tls_align = ph->p_align;
1235 if (ph->p_align == 0)
1236 main_map->l_tls_firstbyte_offset = 0;
1237 else
1238 main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1239 & (ph->p_align - 1));
1240 main_map->l_tls_initimage_size = ph->p_filesz;
1241 main_map->l_tls_initimage = (void *) ph->p_vaddr;
1242
1243 /* This image gets the ID one. */
1244 GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
1245 }
1246 break;
1247
1248 case PT_GNU_STACK:
1249 GL(dl_stack_flags) = ph->p_flags;
1250 break;
1251
1252 case PT_GNU_RELRO:
1253 main_map->l_relro_addr = ph->p_vaddr;
1254 main_map->l_relro_size = ph->p_memsz;
1255 break;
1256 }
1257
1258 /* Adjust the address of the TLS initialization image in case
1259 the executable is actually an ET_DYN object. */
1260 if (main_map->l_tls_initimage != NULL)
1261 main_map->l_tls_initimage
1262 = (char *) main_map->l_tls_initimage + main_map->l_addr;
1263 if (! main_map->l_map_end)
1264 main_map->l_map_end = ~0;
1265 if (! main_map->l_text_end)
1266 main_map->l_text_end = ~0;
1267 if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1268 {
1269 /* We were invoked directly, so the program might not have a
1270 PT_INTERP. */
1271 _dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1272 /* _dl_rtld_libname.next = NULL; Already zero. */
1273 GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1274 }
1275 else
1276 assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
1277
1278 /* If the current libname is different from the SONAME, add the
1279 latter as well. */
1280 if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1281 && strcmp (GL(dl_rtld_map).l_libname->name,
1282 (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1283 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
1284 {
1285 static struct libname_list newname;
1286 newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1287 + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1288 newname.next = NULL;
1289 newname.dont_free = 1;
1290
1291 assert (GL(dl_rtld_map).l_libname->next == NULL);
1292 GL(dl_rtld_map).l_libname->next = &newname;
1293 }
1294 /* The ld.so must be relocated since otherwise loading audit modules
1295 will fail since they reuse the very same ld.so. */
1296 assert (GL(dl_rtld_map).l_relocated);
1297
1298 if (! rtld_is_main)
1299 {
1300 /* Extract the contents of the dynamic section for easy access. */
1301 elf_get_dynamic_info (main_map, NULL);
1302 /* Set up our cache of pointers into the hash table. */
1303 _dl_setup_hash (main_map);
1304 }
1305
1306 if (__builtin_expect (mode, normal) == verify)
1307 {
1308 /* We were called just to verify that this is a dynamic
1309 executable using us as the program interpreter. Exit with an
1310 error if we were not able to load the binary or no interpreter
1311 is specified (i.e., this is no dynamically linked binary. */
1312 if (main_map->l_ld == NULL)
1313 _exit (1);
1314
1315 /* We allow here some platform specific code. */
1316 #ifdef DISTINGUISH_LIB_VERSIONS
1317 DISTINGUISH_LIB_VERSIONS;
1318 #endif
1319 _exit (has_interp ? 0 : 2);
1320 }
1321
1322 struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1323 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1324 /* Set up the data structures for the system-supplied DSO early,
1325 so they can influence _dl_init_paths. */
1326 if (GLRO(dl_sysinfo_dso) != NULL)
1327 {
1328 /* Do an abridged version of the work _dl_map_object_from_fd would do
1329 to map in the object. It's already mapped and prelinked (and
1330 better be, since it's read-only and so we couldn't relocate it).
1331 We just want our data structures to describe it as if we had just
1332 mapped and relocated it normally. */
1333 struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
1334 0, LM_ID_BASE);
1335 if (__builtin_expect (l != NULL, 1))
1336 {
1337 static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
1338
1339 l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
1340 + GLRO(dl_sysinfo_dso)->e_phoff);
1341 l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
1342 for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
1343 {
1344 const ElfW(Phdr) *const ph = &l->l_phdr[i];
1345 if (ph->p_type == PT_DYNAMIC)
1346 {
1347 l->l_ld = (void *) ph->p_vaddr;
1348 l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
1349 }
1350 else if (ph->p_type == PT_LOAD)
1351 {
1352 if (! l->l_addr)
1353 l->l_addr = ph->p_vaddr;
1354 if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
1355 l->l_map_end = ph->p_vaddr + ph->p_memsz;
1356 if ((ph->p_flags & PF_X)
1357 && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
1358 l->l_text_end = ph->p_vaddr + ph->p_memsz;
1359 }
1360 else
1361 /* There must be no TLS segment. */
1362 assert (ph->p_type != PT_TLS);
1363 }
1364 l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
1365 l->l_addr = l->l_map_start - l->l_addr;
1366 l->l_map_end += l->l_addr;
1367 l->l_text_end += l->l_addr;
1368 l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
1369 elf_get_dynamic_info (l, dyn_temp);
1370 _dl_setup_hash (l);
1371 l->l_relocated = 1;
1372
1373 /* Initialize l_local_scope to contain just this map. This allows
1374 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
1375 So we create a single entry list pointing to l_real as its only
1376 element */
1377 l->l_local_scope[0]->r_nlist = 1;
1378 l->l_local_scope[0]->r_list = &l->l_real;
1379
1380 /* Now that we have the info handy, use the DSO image's soname
1381 so this object can be looked up by name. Note that we do not
1382 set l_name here. That field gives the file name of the DSO,
1383 and this DSO is not associated with any file. */
1384 if (l->l_info[DT_SONAME] != NULL)
1385 {
1386 /* Work around a kernel problem. The kernel cannot handle
1387 addresses in the vsyscall DSO pages in writev() calls. */
1388 const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
1389 + l->l_info[DT_SONAME]->d_un.d_val);
1390 size_t len = strlen (dsoname);
1391 char *copy = malloc (len);
1392 if (copy == NULL)
1393 _dl_fatal_printf ("out of memory\n");
1394 l->l_libname->name = l->l_name = memcpy (copy, dsoname, len);
1395 }
1396
1397 /* Add the vDSO to the object list. */
1398 _dl_add_to_namespace_list (l, LM_ID_BASE);
1399
1400 /* Rearrange the list so this DSO appears after rtld_map. */
1401 assert (l->l_next == NULL);
1402 assert (l->l_prev == main_map);
1403 GL(dl_rtld_map).l_next = l;
1404 l->l_prev = &GL(dl_rtld_map);
1405 first_preload = &l->l_next;
1406
1407 /* We have a prelinked DSO preloaded by the system. */
1408 GLRO(dl_sysinfo_map) = l;
1409 # ifdef NEED_DL_SYSINFO
1410 if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1411 GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
1412 # endif
1413 }
1414 }
1415 #endif
1416
1417 #ifdef DL_SYSDEP_OSCHECK
1418 DL_SYSDEP_OSCHECK (dl_fatal);
1419 #endif
1420
1421 /* Initialize the data structures for the search paths for shared
1422 objects. */
1423 _dl_init_paths (library_path);
1424
1425 /* Initialize _r_debug. */
1426 struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1427 LM_ID_BASE);
1428 r->r_state = RT_CONSISTENT;
1429
1430 /* Put the link_map for ourselves on the chain so it can be found by
1431 name. Note that at this point the global chain of link maps contains
1432 exactly one element, which is pointed to by dl_loaded. */
1433 if (! GL(dl_rtld_map).l_name)
1434 /* If not invoked directly, the dynamic linker shared object file was
1435 found by the PT_INTERP name. */
1436 GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1437 GL(dl_rtld_map).l_type = lt_library;
1438 main_map->l_next = &GL(dl_rtld_map);
1439 GL(dl_rtld_map).l_prev = main_map;
1440 ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1441 ++GL(dl_load_adds);
1442
1443 /* If LD_USE_LOAD_BIAS env variable has not been seen, default
1444 to not using bias for non-prelinked PIEs and libraries
1445 and using it for executables or prelinked PIEs or libraries. */
1446 if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
1447 GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
1448
1449 /* Set up the program header information for the dynamic linker
1450 itself. It is needed in the dl_iterate_phdr() callbacks. */
1451 ElfW(Ehdr) *rtld_ehdr = (ElfW(Ehdr) *) GL(dl_rtld_map).l_map_start;
1452 ElfW(Phdr) *rtld_phdr = (ElfW(Phdr) *) (GL(dl_rtld_map).l_map_start
1453 + rtld_ehdr->e_phoff);
1454 GL(dl_rtld_map).l_phdr = rtld_phdr;
1455 GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1456
1457
1458 /* PT_GNU_RELRO is usually the last phdr. */
1459 size_t cnt = rtld_ehdr->e_phnum;
1460 while (cnt-- > 0)
1461 if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1462 {
1463 GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1464 GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1465 break;
1466 }
1467
1468 /* Add the dynamic linker to the TLS list if it also uses TLS. */
1469 if (GL(dl_rtld_map).l_tls_blocksize != 0)
1470 /* Assign a module ID. Do this before loading any audit modules. */
1471 GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1472
1473 /* If we have auditing DSOs to load, do it now. */
1474 if (__builtin_expect (audit_list != NULL, 0))
1475 {
1476 /* Iterate over all entries in the list. The order is important. */
1477 struct audit_ifaces *last_audit = NULL;
1478 struct audit_list *al = audit_list->next;
1479
1480 /* Since we start using the auditing DSOs right away we need to
1481 initialize the data structures now. */
1482 tcbp = init_tls ();
1483
1484 /* Initialize security features. We need to do it this early
1485 since otherwise the constructors of the audit libraries will
1486 use different values (especially the pointer guard) and will
1487 fail later on. */
1488 security_init ();
1489
1490 do
1491 {
1492 int tls_idx = GL(dl_tls_max_dtv_idx);
1493
1494 /* Now it is time to determine the layout of the static TLS
1495 block and allocate it for the initial thread. Note that we
1496 always allocate the static block, we never defer it even if
1497 no DF_STATIC_TLS bit is set. The reason is that we know
1498 glibc will use the static model. */
1499 struct dlmopen_args dlmargs;
1500 dlmargs.fname = al->name;
1501 dlmargs.map = NULL;
1502
1503 const char *objname;
1504 const char *err_str = NULL;
1505 bool malloced;
1506 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
1507 &dlmargs);
1508 if (__builtin_expect (err_str != NULL, 0))
1509 {
1510 not_loaded:
1511 _dl_error_printf ("\
1512 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
1513 al->name, err_str);
1514 if (malloced)
1515 free ((char *) err_str);
1516 }
1517 else
1518 {
1519 struct lookup_args largs;
1520 largs.name = "la_version";
1521 largs.map = dlmargs.map;
1522
1523 /* Check whether the interface version matches. */
1524 (void) _dl_catch_error (&objname, &err_str, &malloced,
1525 lookup_doit, &largs);
1526
1527 unsigned int (*laversion) (unsigned int);
1528 unsigned int lav;
1529 if (err_str == NULL
1530 && (laversion = largs.result) != NULL
1531 && (lav = laversion (LAV_CURRENT)) > 0
1532 && lav <= LAV_CURRENT)
1533 {
1534 /* Allocate structure for the callback function pointers.
1535 This call can never fail. */
1536 union
1537 {
1538 struct audit_ifaces ifaces;
1539 #define naudit_ifaces 8
1540 void (*fptr[naudit_ifaces]) (void);
1541 } *newp = malloc (sizeof (*newp));
1542
1543 /* Names of the auditing interfaces. All in one
1544 long string. */
1545 static const char audit_iface_names[] =
1546 "la_activity\0"
1547 "la_objsearch\0"
1548 "la_objopen\0"
1549 "la_preinit\0"
1550 #if __ELF_NATIVE_CLASS == 32
1551 "la_symbind32\0"
1552 #elif __ELF_NATIVE_CLASS == 64
1553 "la_symbind64\0"
1554 #else
1555 # error "__ELF_NATIVE_CLASS must be defined"
1556 #endif
1557 #define STRING(s) __STRING (s)
1558 "la_" STRING (ARCH_LA_PLTENTER) "\0"
1559 "la_" STRING (ARCH_LA_PLTEXIT) "\0"
1560 "la_objclose\0";
1561 unsigned int cnt = 0;
1562 const char *cp = audit_iface_names;
1563 do
1564 {
1565 largs.name = cp;
1566 (void) _dl_catch_error (&objname, &err_str, &malloced,
1567 lookup_doit, &largs);
1568
1569 /* Store the pointer. */
1570 if (err_str == NULL && largs.result != NULL)
1571 {
1572 newp->fptr[cnt] = largs.result;
1573
1574 /* The dynamic linker link map is statically
1575 allocated, initialize the data now. */
1576 GL(dl_rtld_map).l_audit[cnt].cookie
1577 = (intptr_t) &GL(dl_rtld_map);
1578 }
1579 else
1580 newp->fptr[cnt] = NULL;
1581 ++cnt;
1582
1583 cp = (char *) rawmemchr (cp, '\0') + 1;
1584 }
1585 while (*cp != '\0');
1586 assert (cnt == naudit_ifaces);
1587
1588 /* Now append the new auditing interface to the list. */
1589 newp->ifaces.next = NULL;
1590 if (last_audit == NULL)
1591 last_audit = GLRO(dl_audit) = &newp->ifaces;
1592 else
1593 last_audit = last_audit->next = &newp->ifaces;
1594 ++GLRO(dl_naudit);
1595
1596 /* Mark the DSO as being used for auditing. */
1597 dlmargs.map->l_auditing = 1;
1598 }
1599 else
1600 {
1601 /* We cannot use the DSO, it does not have the
1602 appropriate interfaces or it expects something
1603 more recent. */
1604 #ifndef NDEBUG
1605 Lmid_t ns = dlmargs.map->l_ns;
1606 #endif
1607 _dl_close (dlmargs.map);
1608
1609 /* Make sure the namespace has been cleared entirely. */
1610 assert (GL(dl_ns)[ns]._ns_loaded == NULL);
1611 assert (GL(dl_ns)[ns]._ns_nloaded == 0);
1612
1613 GL(dl_tls_max_dtv_idx) = tls_idx;
1614 goto not_loaded;
1615 }
1616 }
1617
1618 al = al->next;
1619 }
1620 while (al != audit_list->next);
1621
1622 /* If we have any auditing modules, announce that we already
1623 have two objects loaded. */
1624 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1625 {
1626 struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
1627
1628 for (unsigned int outer = 0; outer < 2; ++outer)
1629 {
1630 struct audit_ifaces *afct = GLRO(dl_audit);
1631 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1632 {
1633 if (afct->objopen != NULL)
1634 {
1635 ls[outer]->l_audit[cnt].bindflags
1636 = afct->objopen (ls[outer], LM_ID_BASE,
1637 &ls[outer]->l_audit[cnt].cookie);
1638
1639 ls[outer]->l_audit_any_plt
1640 |= ls[outer]->l_audit[cnt].bindflags != 0;
1641 }
1642
1643 afct = afct->next;
1644 }
1645 }
1646 }
1647 }
1648
1649 /* Set up debugging before the debugger is notified for the first time. */
1650 #ifdef ELF_MACHINE_DEBUG_SETUP
1651 /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
1652 ELF_MACHINE_DEBUG_SETUP (main_map, r);
1653 ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1654 #else
1655 if (main_map->l_info[DT_DEBUG] != NULL)
1656 /* There is a DT_DEBUG entry in the dynamic section. Fill it in
1657 with the run-time address of the r_debug structure */
1658 main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1659
1660 /* Fill in the pointer in the dynamic linker's own dynamic section, in
1661 case you run gdb on the dynamic linker directly. */
1662 if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1663 GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1664 #endif
1665
1666 /* We start adding objects. */
1667 r->r_state = RT_ADD;
1668 _dl_debug_state ();
1669
1670 /* Auditing checkpoint: we are ready to signal that the initial map
1671 is being constructed. */
1672 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
1673 {
1674 struct audit_ifaces *afct = GLRO(dl_audit);
1675 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
1676 {
1677 if (afct->activity != NULL)
1678 afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
1679
1680 afct = afct->next;
1681 }
1682 }
1683
1684 /* We have two ways to specify objects to preload: via environment
1685 variable and via the file /etc/ld.so.preload. The latter can also
1686 be used when security is enabled. */
1687 assert (*first_preload == NULL);
1688 struct link_map **preloads = NULL;
1689 unsigned int npreloads = 0;
1690
1691 if (__builtin_expect (preloadlist != NULL, 0))
1692 {
1693 /* The LD_PRELOAD environment variable gives list of libraries
1694 separated by white space or colons that are loaded before the
1695 executable's dependencies and prepended to the global scope
1696 list. If the binary is running setuid all elements
1697 containing a '/' are ignored since it is insecure. */
1698 char *list = strdupa (preloadlist);
1699 char *p;
1700
1701 HP_TIMING_NOW (start);
1702
1703 /* Prevent optimizing strsep. Speed is not important here. */
1704 while ((p = (strsep) (&list, " :")) != NULL)
1705 if (p[0] != '\0'
1706 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
1707 || strchr (p, '/') == NULL))
1708 npreloads += do_preload (p, main_map, "LD_PRELOAD");
1709
1710 HP_TIMING_NOW (stop);
1711 HP_TIMING_DIFF (diff, start, stop);
1712 HP_TIMING_ACCUM_NT (load_time, diff);
1713 }
1714
1715 /* There usually is no ld.so.preload file, it should only be used
1716 for emergencies and testing. So the open call etc should usually
1717 fail. Using access() on a non-existing file is faster than using
1718 open(). So we do this first. If it succeeds we do almost twice
1719 the work but this does not matter, since it is not for production
1720 use. */
1721 static const char preload_file[] = "/etc/ld.so.preload";
1722 if (__builtin_expect (__access (preload_file, R_OK) == 0, 0))
1723 {
1724 /* Read the contents of the file. */
1725 file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1726 PROT_READ | PROT_WRITE);
1727 if (__builtin_expect (file != MAP_FAILED, 0))
1728 {
1729 /* Parse the file. It contains names of libraries to be loaded,
1730 separated by white spaces or `:'. It may also contain
1731 comments introduced by `#'. */
1732 char *problem;
1733 char *runp;
1734 size_t rest;
1735
1736 /* Eliminate comments. */
1737 runp = file;
1738 rest = file_size;
1739 while (rest > 0)
1740 {
1741 char *comment = memchr (runp, '#', rest);
1742 if (comment == NULL)
1743 break;
1744
1745 rest -= comment - runp;
1746 do
1747 *comment = ' ';
1748 while (--rest > 0 && *++comment != '\n');
1749 }
1750
1751 /* We have one problematic case: if we have a name at the end of
1752 the file without a trailing terminating characters, we cannot
1753 place the \0. Handle the case separately. */
1754 if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
1755 && file[file_size - 1] != '\n' && file[file_size - 1] != ':')
1756 {
1757 problem = &file[file_size];
1758 while (problem > file && problem[-1] != ' '
1759 && problem[-1] != '\t'
1760 && problem[-1] != '\n' && problem[-1] != ':')
1761 --problem;
1762
1763 if (problem > file)
1764 problem[-1] = '\0';
1765 }
1766 else
1767 {
1768 problem = NULL;
1769 file[file_size - 1] = '\0';
1770 }
1771
1772 HP_TIMING_NOW (start);
1773
1774 if (file != problem)
1775 {
1776 char *p;
1777 runp = file;
1778 while ((p = strsep (&runp, ": \t\n")) != NULL)
1779 if (p[0] != '\0')
1780 npreloads += do_preload (p, main_map, preload_file);
1781 }
1782
1783 if (problem != NULL)
1784 {
1785 char *p = strndupa (problem, file_size - (problem - file));
1786
1787 npreloads += do_preload (p, main_map, preload_file);
1788 }
1789
1790 HP_TIMING_NOW (stop);
1791 HP_TIMING_DIFF (diff, start, stop);
1792 HP_TIMING_ACCUM_NT (load_time, diff);
1793
1794 /* We don't need the file anymore. */
1795 __munmap (file, file_size);
1796 }
1797 }
1798
1799 if (__builtin_expect (*first_preload != NULL, 0))
1800 {
1801 /* Set up PRELOADS with a vector of the preloaded libraries. */
1802 struct link_map *l = *first_preload;
1803 preloads = __alloca (npreloads * sizeof preloads[0]);
1804 i = 0;
1805 do
1806 {
1807 preloads[i++] = l;
1808 l = l->l_next;
1809 } while (l);
1810 assert (i == npreloads);
1811 }
1812
1813 /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
1814 specified some libraries to load, these are inserted before the actual
1815 dependencies in the executable's searchlist for symbol resolution. */
1816 HP_TIMING_NOW (start);
1817 _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
1818 HP_TIMING_NOW (stop);
1819 HP_TIMING_DIFF (diff, start, stop);
1820 HP_TIMING_ACCUM_NT (load_time, diff);
1821
1822 /* Mark all objects as being in the global scope. */
1823 for (i = main_map->l_searchlist.r_nlist; i > 0; )
1824 main_map->l_searchlist.r_list[--i]->l_global = 1;
1825
1826 /* Remove _dl_rtld_map from the chain. */
1827 GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1828 if (GL(dl_rtld_map).l_next != NULL)
1829 GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1830
1831 for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
1832 if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1833 break;
1834
1835 bool rtld_multiple_ref = false;
1836 if (__builtin_expect (i < main_map->l_searchlist.r_nlist, 1))
1837 {
1838 /* Some DT_NEEDED entry referred to the interpreter object itself, so
1839 put it back in the list of visible objects. We insert it into the
1840 chain in symbol search order because gdb uses the chain's order as
1841 its symbol search order. */
1842 rtld_multiple_ref = true;
1843
1844 GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
1845 if (__builtin_expect (mode, normal) == normal)
1846 {
1847 GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
1848 ? main_map->l_searchlist.r_list[i + 1]
1849 : NULL);
1850 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
1851 if (GLRO(dl_sysinfo_map) != NULL
1852 && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1853 && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1854 GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1855 #endif
1856 }
1857 else
1858 /* In trace mode there might be an invisible object (which we
1859 could not find) after the previous one in the search list.
1860 In this case it doesn't matter much where we put the
1861 interpreter object, so we just initialize the list pointer so
1862 that the assertion below holds. */
1863 GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1864
1865 assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1866 GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1867 if (GL(dl_rtld_map).l_next != NULL)
1868 {
1869 assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1870 GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1871 }
1872 }
1873
1874 /* Now let us see whether all libraries are available in the
1875 versions we need. */
1876 {
1877 struct version_check_args args;
1878 args.doexit = mode == normal;
1879 args.dotrace = mode == trace;
1880 _dl_receive_error (print_missing_version, version_check_doit, &args);
1881 }
1882
1883 /* We do not initialize any of the TLS functionality unless any of the
1884 initial modules uses TLS. This makes dynamic loading of modules with
1885 TLS impossible, but to support it requires either eagerly doing setup
1886 now or lazily doing it later. Doing it now makes us incompatible with
1887 an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1888 used. Trying to do it lazily is too hairy to try when there could be
1889 multiple threads (from a non-TLS-using libpthread). */
1890 bool was_tls_init_tp_called = tls_init_tp_called;
1891 if (tcbp == NULL)
1892 tcbp = init_tls ();
1893
1894 if (__builtin_expect (audit_list == NULL, 1))
1895 /* Initialize security features. But only if we have not done it
1896 earlier. */
1897 security_init ();
1898
1899 if (__builtin_expect (mode, normal) != normal)
1900 {
1901 /* We were run just to list the shared libraries. It is
1902 important that we do this before real relocation, because the
1903 functions we call below for output may no longer work properly
1904 after relocation. */
1905 struct link_map *l;
1906
1907 if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
1908 {
1909 struct r_scope_elem *scope = &main_map->l_searchlist;
1910
1911 for (i = 0; i < scope->r_nlist; i++)
1912 {
1913 l = scope->r_list [i];
1914 if (l->l_faked)
1915 {
1916 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1917 continue;
1918 }
1919 if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
1920 GLRO(dl_trace_prelink_map) = l;
1921 _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
1922 l->l_libname->name[0] ? l->l_libname->name
1923 : rtld_progname ?: "<main program>",
1924 l->l_name[0] ? l->l_name
1925 : rtld_progname ?: "<main program>",
1926 (int) sizeof l->l_map_start * 2,
1927 (size_t) l->l_map_start,
1928 (int) sizeof l->l_addr * 2,
1929 (size_t) l->l_addr);
1930
1931 if (l->l_tls_modid)
1932 _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
1933 (int) sizeof l->l_tls_offset * 2,
1934 (size_t) l->l_tls_offset);
1935 else
1936 _dl_printf ("\n");
1937 }
1938 }
1939 else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
1940 {
1941 /* Look through the dependencies of the main executable
1942 and determine which of them is not actually
1943 required. */
1944 struct link_map *l = main_map;
1945
1946 /* Relocate the main executable. */
1947 struct relocate_args args = { .l = l,
1948 .reloc_mode = (GLRO(dl_lazy)
1949 ? RTLD_LAZY : 0) };
1950 _dl_receive_error (print_unresolved, relocate_doit, &args);
1951
1952 /* This loop depends on the dependencies of the executable to
1953 correspond in number and order to the DT_NEEDED entries. */
1954 ElfW(Dyn) *dyn = main_map->l_ld;
1955 bool first = true;
1956 while (dyn->d_tag != DT_NULL)
1957 {
1958 if (dyn->d_tag == DT_NEEDED)
1959 {
1960 l = l->l_next;
1961
1962 if (!l->l_used)
1963 {
1964 if (first)
1965 {
1966 _dl_printf ("Unused direct dependencies:\n");
1967 first = false;
1968 }
1969
1970 _dl_printf ("\t%s\n", l->l_name);
1971 }
1972 }
1973
1974 ++dyn;
1975 }
1976
1977 _exit (first != true);
1978 }
1979 else if (! main_map->l_info[DT_NEEDED])
1980 _dl_printf ("\tstatically linked\n");
1981 else
1982 {
1983 for (l = main_map->l_next; l; l = l->l_next)
1984 if (l->l_faked)
1985 /* The library was not found. */
1986 _dl_printf ("\t%s => not found\n", l->l_libname->name);
1987 else if (strcmp (l->l_libname->name, l->l_name) == 0)
1988 _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
1989 (int) sizeof l->l_map_start * 2,
1990 (size_t) l->l_map_start);
1991 else
1992 _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
1993 l->l_name, (int) sizeof l->l_map_start * 2,
1994 (size_t) l->l_map_start);
1995 }
1996
1997 if (__builtin_expect (mode, trace) != trace)
1998 for (i = 1; i < (unsigned int) _dl_argc; ++i)
1999 {
2000 const ElfW(Sym) *ref = NULL;
2001 ElfW(Addr) loadbase;
2002 lookup_t result;
2003
2004 result = _dl_lookup_symbol_x (INTUSE(_dl_argv)[i], main_map,
2005 &ref, main_map->l_scope,
2006 NULL, ELF_RTYPE_CLASS_PLT,
2007 DL_LOOKUP_ADD_DEPENDENCY, NULL);
2008
2009 loadbase = LOOKUP_VALUE_ADDRESS (result);
2010
2011 _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
2012 INTUSE(_dl_argv)[i],
2013 (int) sizeof ref->st_value * 2,
2014 (size_t) ref->st_value,
2015 (int) sizeof loadbase * 2, (size_t) loadbase);
2016 }
2017 else
2018 {
2019 /* If LD_WARN is set, warn about undefined symbols. */
2020 if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
2021 {
2022 /* We have to do symbol dependency testing. */
2023 struct relocate_args args;
2024 struct link_map *l;
2025
2026 args.reloc_mode = GLRO(dl_lazy) ? RTLD_LAZY : 0;
2027
2028 l = main_map;
2029 while (l->l_next != NULL)
2030 l = l->l_next;
2031 do
2032 {
2033 if (l != &GL(dl_rtld_map) && ! l->l_faked)
2034 {
2035 args.l = l;
2036 _dl_receive_error (print_unresolved, relocate_doit,
2037 &args);
2038 }
2039 l = l->l_prev;
2040 }
2041 while (l != NULL);
2042
2043 if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2044 && rtld_multiple_ref)
2045 {
2046 /* Mark the link map as not yet relocated again. */
2047 GL(dl_rtld_map).l_relocated = 0;
2048 _dl_relocate_object (&GL(dl_rtld_map),
2049 main_map->l_scope, 0, 0);
2050 }
2051 }
2052 #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2053 if (version_info)
2054 {
2055 /* Print more information. This means here, print information
2056 about the versions needed. */
2057 int first = 1;
2058 struct link_map *map;
2059
2060 for (map = main_map; map != NULL; map = map->l_next)
2061 {
2062 const char *strtab;
2063 ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2064 ElfW(Verneed) *ent;
2065
2066 if (dyn == NULL)
2067 continue;
2068
2069 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2070 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2071
2072 if (first)
2073 {
2074 _dl_printf ("\n\tVersion information:\n");
2075 first = 0;
2076 }
2077
2078 _dl_printf ("\t%s:\n",
2079 map->l_name[0] ? map->l_name : rtld_progname);
2080
2081 while (1)
2082 {
2083 ElfW(Vernaux) *aux;
2084 struct link_map *needed;
2085
2086 needed = find_needed (strtab + ent->vn_file);
2087 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
2088
2089 while (1)
2090 {
2091 const char *fname = NULL;
2092
2093 if (needed != NULL
2094 && match_version (strtab + aux->vna_name,
2095 needed))
2096 fname = needed->l_name;
2097
2098 _dl_printf ("\t\t%s (%s) %s=> %s\n",
2099 strtab + ent->vn_file,
2100 strtab + aux->vna_name,
2101 aux->vna_flags & VER_FLG_WEAK
2102 ? "[WEAK] " : "",
2103 fname ?: "not found");
2104
2105 if (aux->vna_next == 0)
2106 /* No more symbols. */
2107 break;
2108
2109 /* Next symbol. */
2110 aux = (ElfW(Vernaux) *) ((char *) aux
2111 + aux->vna_next);
2112 }
2113
2114 if (ent->vn_next == 0)
2115 /* No more dependencies. */
2116 break;
2117
2118 /* Next dependency. */
2119 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
2120 }
2121 }
2122 }
2123 }
2124
2125 _exit (0);
2126 }
2127
2128 if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2129 && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
2130 && ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
2131 {
2132 ElfW(Lib) *liblist, *liblistend;
2133 struct link_map **r_list, **r_listend, *l;
2134 const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
2135
2136 assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2137 liblist = (ElfW(Lib) *)
2138 main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2139 liblistend = (ElfW(Lib) *)
2140 ((char *) liblist +
2141 main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2142 r_list = main_map->l_searchlist.r_list;
2143 r_listend = r_list + main_map->l_searchlist.r_nlist;
2144
2145 for (; r_list < r_listend && liblist < liblistend; r_list++)
2146 {
2147 l = *r_list;
2148
2149 if (l == main_map)
2150 continue;
2151
2152 /* If the library is not mapped where it should, fail. */
2153 if (l->l_addr)
2154 break;
2155
2156 /* Next, check if checksum matches. */
2157 if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2158 || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2159 != liblist->l_checksum)
2160 break;
2161
2162 if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2163 || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2164 != liblist->l_time_stamp)
2165 break;
2166
2167 if (! _dl_name_match_p (strtab + liblist->l_name, l))
2168 break;
2169
2170 ++liblist;
2171 }
2172
2173
2174 if (r_list == r_listend && liblist == liblistend)
2175 prelinked = true;
2176
2177 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))
2178 _dl_debug_printf ("\nprelink checking: %s\n",
2179 prelinked ? "ok" : "failed");
2180 }
2181
2182
2183 /* Now set up the variable which helps the assembler startup code. */
2184 GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2185
2186 /* Save the information about the original global scope list since
2187 we need it in the memory handling later. */
2188 GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2189
2190 /* Remember the last search directory added at startup, now that
2191 malloc will no longer be the one from dl-minimal.c. */
2192 GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2193
2194 /* Print scope information. */
2195 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES, 0))
2196 {
2197 _dl_debug_printf ("\nInitial object scopes\n");
2198
2199 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2200 _dl_show_scope (l, 0);
2201 }
2202
2203 if (prelinked)
2204 {
2205 if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2206 {
2207 ElfW(Rela) *conflict, *conflictend;
2208 #ifndef HP_TIMING_NONAVAIL
2209 hp_timing_t start;
2210 hp_timing_t stop;
2211 #endif
2212
2213 HP_TIMING_NOW (start);
2214 assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2215 conflict = (ElfW(Rela) *)
2216 main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2217 conflictend = (ElfW(Rela) *)
2218 ((char *) conflict
2219 + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2220 _dl_resolve_conflicts (main_map, conflict, conflictend);
2221 HP_TIMING_NOW (stop);
2222 HP_TIMING_DIFF (relocate_time, start, stop);
2223 }
2224
2225
2226 /* Mark all the objects so we know they have been already relocated. */
2227 for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2228 {
2229 l->l_relocated = 1;
2230 if (l->l_relro_size)
2231 _dl_protect_relro (l);
2232
2233 /* Add object to slot information data if necessasy. */
2234 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2235 _dl_add_to_slotinfo (l);
2236 }
2237 }
2238 else
2239 {
2240 /* Now we have all the objects loaded. Relocate them all except for
2241 the dynamic linker itself. We do this in reverse order so that copy
2242 relocs of earlier objects overwrite the data written by later
2243 objects. We do not re-relocate the dynamic linker itself in this
2244 loop because that could result in the GOT entries for functions we
2245 call being changed, and that would break us. It is safe to relocate
2246 the dynamic linker out of order because it has no copy relocs (we
2247 know that because it is self-contained). */
2248
2249 int consider_profiling = GLRO(dl_profile) != NULL;
2250 #ifndef HP_TIMING_NONAVAIL
2251 hp_timing_t start;
2252 hp_timing_t stop;
2253 #endif
2254
2255 /* If we are profiling we also must do lazy reloaction. */
2256 GLRO(dl_lazy) |= consider_profiling;
2257
2258 HP_TIMING_NOW (start);
2259 unsigned i = main_map->l_searchlist.r_nlist;
2260 while (i-- > 0)
2261 {
2262 struct link_map *l = main_map->l_initfini[i];
2263
2264 /* While we are at it, help the memory handling a bit. We have to
2265 mark some data structures as allocated with the fake malloc()
2266 implementation in ld.so. */
2267 struct libname_list *lnp = l->l_libname->next;
2268
2269 while (__builtin_expect (lnp != NULL, 0))
2270 {
2271 lnp->dont_free = 1;
2272 lnp = lnp->next;
2273 }
2274
2275 if (l != &GL(dl_rtld_map))
2276 _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
2277 consider_profiling);
2278
2279 /* Add object to slot information data if necessasy. */
2280 if (l->l_tls_blocksize != 0 && tls_init_tp_called)
2281 _dl_add_to_slotinfo (l);
2282 }
2283 HP_TIMING_NOW (stop);
2284
2285 HP_TIMING_DIFF (relocate_time, start, stop);
2286
2287 /* Now enable profiling if needed. Like the previous call,
2288 this has to go here because the calls it makes should use the
2289 rtld versions of the functions (particularly calloc()), but it
2290 needs to have _dl_profile_map set up by the relocator. */
2291 if (__builtin_expect (GL(dl_profile_map) != NULL, 0))
2292 /* We must prepare the profiling. */
2293 _dl_start_profile ();
2294 }
2295
2296 #ifndef NONTLS_INIT_TP
2297 # define NONTLS_INIT_TP do { } while (0)
2298 #endif
2299
2300 if (!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
2301 ++GL(dl_tls_generation);
2302
2303 /* Now that we have completed relocation, the initializer data
2304 for the TLS blocks has its final values and we can copy them
2305 into the main thread's TLS area, which we allocated above. */
2306 _dl_allocate_tls_init (tcbp);
2307
2308 /* And finally install it for the main thread. If ld.so itself uses
2309 TLS we know the thread pointer was initialized earlier. */
2310 if (! tls_init_tp_called)
2311 {
2312 const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
2313 if (__builtin_expect (lossage != NULL, 0))
2314 _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2315 lossage);
2316 }
2317
2318 /* Make sure no new search directories have been added. */
2319 assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
2320
2321 if (! prelinked && rtld_multiple_ref)
2322 {
2323 /* There was an explicit ref to the dynamic linker as a shared lib.
2324 Re-relocate ourselves with user-controlled symbol definitions.
2325
2326 We must do this after TLS initialization in case after this
2327 re-relocation, we might call a user-supplied function
2328 (e.g. calloc from _dl_relocate_object) that uses TLS data. */
2329
2330 #ifndef HP_TIMING_NONAVAIL
2331 hp_timing_t start;
2332 hp_timing_t stop;
2333 hp_timing_t add;
2334 #endif
2335
2336 HP_TIMING_NOW (start);
2337 /* Mark the link map as not yet relocated again. */
2338 GL(dl_rtld_map).l_relocated = 0;
2339 _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
2340 HP_TIMING_NOW (stop);
2341 HP_TIMING_DIFF (add, start, stop);
2342 HP_TIMING_ACCUM_NT (relocate_time, add);
2343 }
2344
2345 /* Do any necessary cleanups for the startup OS interface code.
2346 We do these now so that no calls are made after rtld re-relocation
2347 which might be resolved to different functions than we expect.
2348 We cannot do this before relocating the other objects because
2349 _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
2350 _dl_sysdep_start_cleanup ();
2351
2352 #ifdef SHARED
2353 /* Auditing checkpoint: we have added all objects. */
2354 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
2355 {
2356 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2357 /* Do not call the functions for any auditing object. */
2358 if (head->l_auditing == 0)
2359 {
2360 struct audit_ifaces *afct = GLRO(dl_audit);
2361 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
2362 {
2363 if (afct->activity != NULL)
2364 afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
2365
2366 afct = afct->next;
2367 }
2368 }
2369 }
2370 #endif
2371
2372 /* Notify the debugger all new objects are now ready to go. We must re-get
2373 the address since by now the variable might be in another object. */
2374 r = _dl_debug_initialize (0, LM_ID_BASE);
2375 r->r_state = RT_CONSISTENT;
2376 _dl_debug_state ();
2377
2378 #ifndef MAP_COPY
2379 /* We must munmap() the cache file. */
2380 _dl_unload_cache ();
2381 #endif
2382
2383 /* Once we return, _dl_sysdep_start will invoke
2384 the DT_INIT functions and then *USER_ENTRY. */
2385 }
2386 \f
2387 /* This is a little helper function for resolving symbols while
2388 tracing the binary. */
2389 static void
2390 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2391 const char *errstring)
2392 {
2393 if (objname[0] == '\0')
2394 objname = rtld_progname ?: "<main program>";
2395 _dl_error_printf ("%s (%s)\n", errstring, objname);
2396 }
2397 \f
2398 /* This is a little helper function for resolving symbols while
2399 tracing the binary. */
2400 static void
2401 print_missing_version (int errcode __attribute__ ((unused)),
2402 const char *objname, const char *errstring)
2403 {
2404 _dl_error_printf ("%s: %s: %s\n", rtld_progname ?: "<program name unknown>",
2405 objname, errstring);
2406 }
2407 \f
2408 /* Nonzero if any of the debugging options is enabled. */
2409 static int any_debug attribute_relro;
2410
2411 /* Process the string given as the parameter which explains which debugging
2412 options are enabled. */
2413 static void
2414 process_dl_debug (const char *dl_debug)
2415 {
2416 /* When adding new entries make sure that the maximal length of a name
2417 is correctly handled in the LD_DEBUG_HELP code below. */
2418 static const struct
2419 {
2420 unsigned char len;
2421 const char name[10];
2422 const char helptext[41];
2423 unsigned short int mask;
2424 } debopts[] =
2425 {
2426 #define LEN_AND_STR(str) sizeof (str) - 1, str
2427 { LEN_AND_STR ("libs"), "display library search paths",
2428 DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
2429 { LEN_AND_STR ("reloc"), "display relocation processing",
2430 DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
2431 { LEN_AND_STR ("files"), "display progress for input file",
2432 DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
2433 { LEN_AND_STR ("symbols"), "display symbol table processing",
2434 DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
2435 { LEN_AND_STR ("bindings"), "display information about symbol binding",
2436 DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
2437 { LEN_AND_STR ("versions"), "display version dependencies",
2438 DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
2439 { LEN_AND_STR ("scopes"), "display scope information",
2440 DL_DEBUG_SCOPES },
2441 { LEN_AND_STR ("all"), "all previous options combined",
2442 DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
2443 | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS
2444 | DL_DEBUG_SCOPES },
2445 { LEN_AND_STR ("statistics"), "display relocation statistics",
2446 DL_DEBUG_STATISTICS },
2447 { LEN_AND_STR ("unused"), "determined unused DSOs",
2448 DL_DEBUG_UNUSED },
2449 { LEN_AND_STR ("help"), "display this help message and exit",
2450 DL_DEBUG_HELP },
2451 };
2452 #define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2453
2454 /* Skip separating white spaces and commas. */
2455 while (*dl_debug != '\0')
2456 {
2457 if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
2458 {
2459 size_t cnt;
2460 size_t len = 1;
2461
2462 while (dl_debug[len] != '\0' && dl_debug[len] != ' '
2463 && dl_debug[len] != ',' && dl_debug[len] != ':')
2464 ++len;
2465
2466 for (cnt = 0; cnt < ndebopts; ++cnt)
2467 if (debopts[cnt].len == len
2468 && memcmp (dl_debug, debopts[cnt].name, len) == 0)
2469 {
2470 GLRO(dl_debug_mask) |= debopts[cnt].mask;
2471 any_debug = 1;
2472 break;
2473 }
2474
2475 if (cnt == ndebopts)
2476 {
2477 /* Display a warning and skip everything until next
2478 separator. */
2479 char *copy = strndupa (dl_debug, len);
2480 _dl_error_printf ("\
2481 warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2482 }
2483
2484 dl_debug += len;
2485 continue;
2486 }
2487
2488 ++dl_debug;
2489 }
2490
2491 if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2492 {
2493 size_t cnt;
2494
2495 _dl_printf ("\
2496 Valid options for the LD_DEBUG environment variable are:\n\n");
2497
2498 for (cnt = 0; cnt < ndebopts; ++cnt)
2499 _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2500 " " + debopts[cnt].len - 3,
2501 debopts[cnt].helptext);
2502
2503 _dl_printf ("\n\
2504 To direct the debugging output into a file instead of standard output\n\
2505 a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2506 _exit (0);
2507 }
2508 }
2509 \f
2510 static void
2511 process_dl_audit (char *str)
2512 {
2513 /* The parameter is a colon separated list of DSO names. */
2514 char *p;
2515
2516 while ((p = (strsep) (&str, ":")) != NULL)
2517 if (p[0] != '\0'
2518 && (__builtin_expect (! INTUSE(__libc_enable_secure), 1)
2519 || strchr (p, '/') == NULL))
2520 {
2521 /* This is using the local malloc, not the system malloc. The
2522 memory can never be freed. */
2523 struct audit_list *newp = malloc (sizeof (*newp));
2524 newp->name = p;
2525
2526 if (audit_list == NULL)
2527 audit_list = newp->next = newp;
2528 else
2529 {
2530 newp->next = audit_list->next;
2531 audit_list = audit_list->next = newp;
2532 }
2533 }
2534 }
2535 \f
2536 /* Process all environments variables the dynamic linker must recognize.
2537 Since all of them start with `LD_' we are a bit smarter while finding
2538 all the entries. */
2539 extern char **_environ attribute_hidden;
2540
2541
2542 static void
2543 process_envvars (enum mode *modep)
2544 {
2545 char **runp = _environ;
2546 char *envline;
2547 enum mode mode = normal;
2548 char *debug_output = NULL;
2549
2550 /* This is the default place for profiling data file. */
2551 GLRO(dl_profile_output)
2552 = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0];
2553
2554 while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2555 {
2556 size_t len = 0;
2557
2558 while (envline[len] != '\0' && envline[len] != '=')
2559 ++len;
2560
2561 if (envline[len] != '=')
2562 /* This is a "LD_" variable at the end of the string without
2563 a '=' character. Ignore it since otherwise we will access
2564 invalid memory below. */
2565 continue;
2566
2567 switch (len)
2568 {
2569 case 4:
2570 /* Warning level, verbose or not. */
2571 if (memcmp (envline, "WARN", 4) == 0)
2572 GLRO(dl_verbose) = envline[5] != '\0';
2573 break;
2574
2575 case 5:
2576 /* Debugging of the dynamic linker? */
2577 if (memcmp (envline, "DEBUG", 5) == 0)
2578 {
2579 process_dl_debug (&envline[6]);
2580 break;
2581 }
2582 if (memcmp (envline, "AUDIT", 5) == 0)
2583 process_dl_audit (&envline[6]);
2584 break;
2585
2586 case 7:
2587 /* Print information about versions. */
2588 if (memcmp (envline, "VERBOSE", 7) == 0)
2589 {
2590 version_info = envline[8] != '\0';
2591 break;
2592 }
2593
2594 /* List of objects to be preloaded. */
2595 if (memcmp (envline, "PRELOAD", 7) == 0)
2596 {
2597 preloadlist = &envline[8];
2598 break;
2599 }
2600
2601 /* Which shared object shall be profiled. */
2602 if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
2603 GLRO(dl_profile) = &envline[8];
2604 break;
2605
2606 case 8:
2607 /* Do we bind early? */
2608 if (memcmp (envline, "BIND_NOW", 8) == 0)
2609 {
2610 GLRO(dl_lazy) = envline[9] == '\0';
2611 break;
2612 }
2613 if (memcmp (envline, "BIND_NOT", 8) == 0)
2614 GLRO(dl_bind_not) = envline[9] != '\0';
2615 break;
2616
2617 case 9:
2618 /* Test whether we want to see the content of the auxiliary
2619 array passed up from the kernel. */
2620 if (!INTUSE(__libc_enable_secure)
2621 && memcmp (envline, "SHOW_AUXV", 9) == 0)
2622 _dl_show_auxv ();
2623 break;
2624
2625 case 10:
2626 /* Mask for the important hardware capabilities. */
2627 if (memcmp (envline, "HWCAP_MASK", 10) == 0)
2628 GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
2629 0, 0);
2630 break;
2631
2632 case 11:
2633 /* Path where the binary is found. */
2634 if (!INTUSE(__libc_enable_secure)
2635 && memcmp (envline, "ORIGIN_PATH", 11) == 0)
2636 GLRO(dl_origin_path) = &envline[12];
2637 break;
2638
2639 case 12:
2640 /* The library search path. */
2641 if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
2642 {
2643 library_path = &envline[13];
2644 break;
2645 }
2646
2647 /* Where to place the profiling data file. */
2648 if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
2649 {
2650 debug_output = &envline[13];
2651 break;
2652 }
2653
2654 if (!INTUSE(__libc_enable_secure)
2655 && memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
2656 GLRO(dl_dynamic_weak) = 1;
2657 break;
2658
2659 case 13:
2660 /* We might have some extra environment variable with length 13
2661 to handle. */
2662 #ifdef EXTRA_LD_ENVVARS_13
2663 EXTRA_LD_ENVVARS_13
2664 #endif
2665 if (!INTUSE(__libc_enable_secure)
2666 && memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
2667 {
2668 GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
2669 break;
2670 }
2671
2672 if (memcmp (envline, "POINTER_GUARD", 13) == 0)
2673 GLRO(dl_pointer_guard) = envline[14] != '0';
2674 break;
2675
2676 case 14:
2677 /* Where to place the profiling data file. */
2678 if (!INTUSE(__libc_enable_secure)
2679 && memcmp (envline, "PROFILE_OUTPUT", 14) == 0
2680 && envline[15] != '\0')
2681 GLRO(dl_profile_output) = &envline[15];
2682 break;
2683
2684 case 16:
2685 /* The mode of the dynamic linker can be set. */
2686 if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
2687 {
2688 mode = trace;
2689 GLRO(dl_verbose) = 1;
2690 GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
2691 GLRO(dl_trace_prelink) = &envline[17];
2692 }
2693 break;
2694
2695 case 20:
2696 /* The mode of the dynamic linker can be set. */
2697 if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
2698 mode = trace;
2699 break;
2700
2701 /* We might have some extra environment variable to handle. This
2702 is tricky due to the pre-processing of the length of the name
2703 in the switch statement here. The code here assumes that added
2704 environment variables have a different length. */
2705 #ifdef EXTRA_LD_ENVVARS
2706 EXTRA_LD_ENVVARS
2707 #endif
2708 }
2709 }
2710
2711 /* The caller wants this information. */
2712 *modep = mode;
2713
2714 /* Extra security for SUID binaries. Remove all dangerous environment
2715 variables. */
2716 if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
2717 {
2718 static const char unsecure_envvars[] =
2719 #ifdef EXTRA_UNSECURE_ENVVARS
2720 EXTRA_UNSECURE_ENVVARS
2721 #endif
2722 UNSECURE_ENVVARS;
2723 const char *nextp;
2724
2725 nextp = unsecure_envvars;
2726 do
2727 {
2728 unsetenv (nextp);
2729 /* We could use rawmemchr but this need not be fast. */
2730 nextp = (char *) (strchr) (nextp, '\0') + 1;
2731 }
2732 while (*nextp != '\0');
2733
2734 if (__access ("/etc/suid-debug", F_OK) != 0)
2735 {
2736 unsetenv ("MALLOC_CHECK_");
2737 GLRO(dl_debug_mask) = 0;
2738 }
2739
2740 if (mode != normal)
2741 _exit (5);
2742 }
2743 /* If we have to run the dynamic linker in debugging mode and the
2744 LD_DEBUG_OUTPUT environment variable is given, we write the debug
2745 messages to this file. */
2746 else if (any_debug && debug_output != NULL)
2747 {
2748 #ifdef O_NOFOLLOW
2749 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
2750 #else
2751 const int flags = O_WRONLY | O_APPEND | O_CREAT;
2752 #endif
2753 size_t name_len = strlen (debug_output);
2754 char buf[name_len + 12];
2755 char *startp;
2756
2757 buf[name_len + 11] = '\0';
2758 startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
2759 *--startp = '.';
2760 startp = memcpy (startp - name_len, debug_output, name_len);
2761
2762 GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE);
2763 if (GLRO(dl_debug_fd) == -1)
2764 /* We use standard output if opening the file failed. */
2765 GLRO(dl_debug_fd) = STDOUT_FILENO;
2766 }
2767 }
2768
2769
2770 /* Print the various times we collected. */
2771 static void
2772 __attribute ((noinline))
2773 print_statistics (hp_timing_t *rtld_total_timep)
2774 {
2775 #ifndef HP_TIMING_NONAVAIL
2776 char buf[200];
2777 char *cp;
2778 char *wp;
2779
2780 /* Total time rtld used. */
2781 if (HP_TIMING_AVAIL)
2782 {
2783 HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
2784 _dl_debug_printf ("\nruntime linker statistics:\n"
2785 " total startup time in dynamic loader: %s\n", buf);
2786
2787 /* Print relocation statistics. */
2788 char pbuf[30];
2789 HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
2790 cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
2791 pbuf + sizeof (pbuf), 10, 0);
2792 wp = pbuf;
2793 switch (pbuf + sizeof (pbuf) - cp)
2794 {
2795 case 3:
2796 *wp++ = *cp++;
2797 case 2:
2798 *wp++ = *cp++;
2799 case 1:
2800 *wp++ = '.';
2801 *wp++ = *cp++;
2802 }
2803 *wp = '\0';
2804 _dl_debug_printf ("\
2805 time needed for relocation: %s (%s%%)\n", buf, pbuf);
2806 }
2807 #endif
2808
2809 unsigned long int num_relative_relocations = 0;
2810 for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
2811 {
2812 if (GL(dl_ns)[ns]._ns_loaded == NULL)
2813 continue;
2814
2815 struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2816
2817 for (unsigned int i = 0; i < scope->r_nlist; i++)
2818 {
2819 struct link_map *l = scope->r_list [i];
2820
2821 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2822 num_relative_relocations
2823 += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2824 #ifndef ELF_MACHINE_REL_RELATIVE
2825 /* Relative relocations are processed on these architectures if
2826 library is loaded to different address than p_vaddr or
2827 if not prelinked. */
2828 if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2829 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2830 #else
2831 /* On e.g. IA-64 or Alpha, relative relocations are processed
2832 only if library is loaded to different address than p_vaddr. */
2833 if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2834 #endif
2835 num_relative_relocations
2836 += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2837 }
2838 }
2839
2840 _dl_debug_printf (" number of relocations: %lu\n"
2841 " number of relocations from cache: %lu\n"
2842 " number of relative relocations: %lu\n",
2843 GL(dl_num_relocations),
2844 GL(dl_num_cache_relocations),
2845 num_relative_relocations);
2846
2847 #ifndef HP_TIMING_NONAVAIL
2848 /* Time spend while loading the object and the dependencies. */
2849 if (HP_TIMING_AVAIL)
2850 {
2851 char pbuf[30];
2852 HP_TIMING_PRINT (buf, sizeof (buf), load_time);
2853 cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
2854 pbuf + sizeof (pbuf), 10, 0);
2855 wp = pbuf;
2856 switch (pbuf + sizeof (pbuf) - cp)
2857 {
2858 case 3:
2859 *wp++ = *cp++;
2860 case 2:
2861 *wp++ = *cp++;
2862 case 1:
2863 *wp++ = '.';
2864 *wp++ = *cp++;
2865 }
2866 *wp = '\0';
2867 _dl_debug_printf ("\
2868 time needed to load objects: %s (%s%%)\n",
2869 buf, pbuf);
2870 }
2871 #endif
2872 }