rtld.c source code [glibc/elf/rtld.c]

1	/ Run time dynamic linker.*
2	Copyright (C) 1995-2021 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, see
17	<https://www.gnu.org/licenses/>. /*
18
19	#include <errno.h>
20	#include <dlfcn.h>
21	#include <fcntl.h>
22	#include <stdbool.h>
23	#include <stdlib.h>
24	#include <string.h>
25	#include <unistd.h>
26	#include <sys/mman.h>
27	#include <sys/param.h>
28	#include <sys/stat.h>
29	#include <ldsodefs.h>
30	#include <_itoa.h>
31	#include <entry.h>
32	#include <fpu_control.h>
33	#include <hp-timing.h>
34	#include <libc-lock.h>
35	#include "dynamic-link.h"
36	#include <dl-librecon.h>
37	#include <unsecvars.h>
38	#include <dl-cache.h>
39	#include <dl-osinfo.h>
40	#include <dl-procinfo.h>
41	#include <dl-prop.h>
42	#include <dl-vdso.h>
43	#include <dl-vdso-setup.h>
44	#include <tls.h>
45	#include <stap-probe.h>
46	#include <stackinfo.h>
47	#include <not-cancel.h>
48	#include <array_length.h>
49	#include <libc-early-init.h>
50	#include <dl-main.h>
51	#include <list.h>
52	#include <gnu/lib-names.h>
53	#include <dl-tunables.h>
54
55	#include <assert.h>
56
57	/ Only enables rtld profiling for architectures which provides non generic*
58	hp-timing support. The generic support requires either syscall
59	(clock_gettime), which will incur in extra overhead on loading time.
60	Using vDSO is also an option, but it will require extra support on loader
61	to setup the vDSO pointer before its usage. /*
62	#if HP_TIMING_INLINE
63	# define RLTD_TIMING_DECLARE(var, classifier,...) \
64	classifier hp_timing_t var __VA_ARGS__
65	# define RTLD_TIMING_VAR(var) RLTD_TIMING_DECLARE (var, )
66	# define RTLD_TIMING_SET(var, value) (var) = (value)
67	# define RTLD_TIMING_REF(var) &(var)
68
69	static inline void
70	rtld_timer_start (hp_timing_t *var)
71	{
72	HP_TIMING_NOW (*var);
73	}
74
75	static inline void
76	rtld_timer_stop (hp_timing_t *var, hp_timing_t start)
77	{
78	hp_timing_t stop;
79	HP_TIMING_NOW (stop);
80	HP_TIMING_DIFF (*var, start, stop);
81	}
82
83	static inline void
84	rtld_timer_accum (hp_timing_t *sum, hp_timing_t start)
85	{
86	hp_timing_t stop;
87	rtld_timer_stop (&stop, start);
88	HP_TIMING_ACCUM_NT(*sum, stop);
89	}
90	#else
91	# define RLTD_TIMING_DECLARE(var, classifier...)
92	# define RTLD_TIMING_SET(var, value)
93	# define RTLD_TIMING_VAR(var)
94	# define RTLD_TIMING_REF(var) 0
95	# define rtld_timer_start(var)
96	# define rtld_timer_stop(var, start)
97	# define rtld_timer_accum(sum, start)
98	#endif
99
100	/ Avoid PLT use for our local calls at startup. /
101	extern __typeof (__mempcpy) __mempcpy attribute_hidden;
102
103	/ GCC has mental blocks about _exit. /
104	extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
105	#define _exit exit_internal
106
107	/ Helper function to handle errors while resolving symbols. /
108	static void print_unresolved (int errcode, const char *objname,
109	const char *errsting);
110
111	/ Helper function to handle errors when a version is missing. /
112	static void print_missing_version (int errcode, const char *objname,
113	const char *errsting);
114
115	/ Print the various times we collected. /
116	static void print_statistics (const hp_timing_t *total_timep);
117
118	/ Creates an empty audit list. /
119	static void audit_list_init (struct audit_list *);
120
121	/ Add a string to the end of the audit list, for later parsing. Must*
122	not be called after audit_list_next. /*
123	static void audit_list_add_string (struct audit_list , const* char *);
124
125	/ Add the audit strings from the link map, found in the dynamic*
126	segment at TG (either DT_AUDIT and DT_DEPAUDIT). Must be called
127	before audit_list_next. /*
128	static void audit_list_add_dynamic_tag (struct audit_list *,
129	struct link_map *,
130	unsigned int tag);
131
132	/ Extract the next audit module from the audit list. Only modules*
133	for which dso_name_valid_for_suid is true are returned. Must be
134	called after all the audit_list_add_string,
135	audit_list_add_dynamic_tags calls. /*
136	static const char audit_list_next (struct* audit_list *);
137
138	/ Initialize STATE with the defaults. /*
139	static void dl_main_state_init (struct dl_main_state *state);
140
141	/ Process all environments variables the dynamic linker must recognize.*
142	Since all of them start with `LD_' we are a bit smarter while finding
143	all the entries. /*
144	static void process_envvars (struct dl_main_state *state);
145
146	#ifdef DL_ARGV_NOT_RELRO
147	int _dl_argc attribute_hidden;
148	char **_dl_argv = NULL;
149	/ Nonzero if we were run directly. /
150	unsigned int _dl_skip_args attribute_hidden;
151	#else
152	int _dl_argc attribute_relro attribute_hidden;
153	char **_dl_argv attribute_relro = NULL;
154	unsigned int _dl_skip_args attribute_relro attribute_hidden;
155	#endif
156	rtld_hidden_data_def (_dl_argv)
157
158	#ifndef THREAD_SET_STACK_GUARD
159	/ Only exported for architectures that don't store the stack guard canary*
160	in thread local area. /*
161	uintptr_t __stack_chk_guard attribute_relro;
162	#endif
163
164	/ Only exported for architectures that don't store the pointer guard*
165	value in thread local area. /*
166	uintptr_t __pointer_chk_guard_local
167	attribute_relro attribute_hidden __attribute__ ((nocommon));
168	#ifndef THREAD_SET_POINTER_GUARD
169	strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
170	#endif
171
172	/ Check that AT_SECURE=0, or that the passed name does not contain*
173	directories and is not overly long. Reject empty names
174	unconditionally. /*
175	static bool
176	dso_name_valid_for_suid (const char *p)
177	{
178	if (__glibc_unlikely (__libc_enable_secure))
179	{
180	/ Ignore pathnames with directories for AT_SECURE=1*
181	programs, and also skip overlong names. /*
182	size_t len = strlen (p);
183	if (len >= SECURE_NAME_LIMIT \|\| memchr (p, `'/'`, len) != NULL)
184	return false;
185	}
186	return *p != `'\0'`;
187	}
188
189	static void
190	audit_list_init (struct audit_list *list)
191	{
192	list->length = `0`;
193	list->current_index = `0`;
194	list->current_tail = NULL;
195	}
196
197	static void
198	audit_list_add_string (struct audit_list list, const* char *string)
199	{
200	/ Empty strings do not load anything. /
201	if (*string == `'\0'`)
202	return;
203
204	if (list->length == array_length (list->audit_strings))
205	_dl_fatal_printf ("Fatal glibc error: Too many audit modules requested\n");
206
207	list->audit_strings[list->length++] = string;
208
209	/ Initialize processing of the first string for*
210	audit_list_next. /*
211	if (list->length == `1`)
212	list->current_tail = string;
213	}
214
215	static void
216	audit_list_add_dynamic_tag (struct audit_list list, struct* link_map *main_map,
217	unsigned int tag)
218	{
219	ElfW(Dyn) *info = main_map->l_info[ADDRIDX (tag)];
220	const char strtab = (const* char *) D_PTR (main_map, l_info[DT_STRTAB]);
221	if (info != NULL)
222	audit_list_add_string (list, strtab + info->d_un.d_val);
223	}
224
225	static const char *
226	audit_list_next (struct audit_list *list)
227	{
228	if (list->current_tail == NULL)
229	return NULL;
230
231	while (true)
232	{
233	/ Advance to the next string in audit_strings if the current*
234	string has been exhausted. /*
235	while (*list->current_tail == `'\0'`)
236	{
237	++list->current_index;
238	if (list->current_index == list->length)
239	{
240	list->current_tail = NULL;
241	return NULL;
242	}
243	list->current_tail = list->audit_strings[list->current_index];
244	}
245
246	/ Split the in-string audit list at the next colon colon. /
247	size_t len = strcspn (list->current_tail, ":");
248	if (len > `0` && len < sizeof (list->fname))
249	{
250	memcpy (list->fname, list->current_tail, len);
251	list->fname[len] = `'\0'`;
252	}
253	else
254	/ Mark the name as unusable for dso_name_valid_for_suid. /
255	list->fname[`0`] = `'\0'`;
256
257	/ Skip over the substring and the following delimiter. /
258	list->current_tail += len;
259	if (*list->current_tail == `':'`)
260	++list->current_tail;
261
262	/ If the name is valid, return it. /
263	if (dso_name_valid_for_suid (list->fname))
264	return list->fname;
265
266	/ Otherwise wrap around to find the next list element. . /
267	}
268	}
269
270	/ Count audit modules before they are loaded so GLRO(dl_naudit)*
271	is not yet usable. /*
272	static size_t
273	audit_list_count (struct audit_list *list)
274	{
275	/ Restore the audit_list iterator state at the end. /
276	const char *saved_tail = list->current_tail;
277	size_t naudit = `0`;
278
279	assert (list->current_index == `0`);
280	while (audit_list_next (list) != NULL)
281	naudit++;
282	list->current_tail = saved_tail;
283	list->current_index = `0`;
284	return naudit;
285	}
286
287	static void
288	dl_main_state_init (struct dl_main_state *state)
289	{
290	audit_list_init (&state->audit_list);
291	state->library_path = NULL;
292	state->library_path_source = NULL;
293	state->preloadlist = NULL;
294	state->preloadarg = NULL;
295	state->glibc_hwcaps_prepend = NULL;
296	state->glibc_hwcaps_mask = NULL;
297	state->mode = rtld_mode_normal;
298	state->any_debug = false;
299	state->version_info = false;
300	}
301
302	#ifndef HAVE_INLINED_SYSCALLS
303	/ Set nonzero during loading and initialization of executable and*
304	libraries, cleared before the executable's entry point runs. This
305	must not be initialized to nonzero, because the unused dynamic
306	linker loaded in for libc.so's "ld.so.1" dep will provide the
307	definition seen by libc.so's initializer; that value must be zero,
308	and will be since that dynamic linker's _dl_start and dl_main will
309	never be called. /*
310	int _dl_starting_up = `0`;
311	rtld_hidden_def (_dl_starting_up)
312	#endif
313
314	/ This is the structure which defines all variables global to ld.so*
315	(except those which cannot be added for some reason). /*
316	struct rtld_global _rtld_global =
317	{
318	/ Get architecture specific initializer. /
319	#include <dl-procruntime.c>
320	/ Generally the default presumption without further information is an*
321	* executable stack but this is not true for all platforms. */
322	._dl_stack_flags = DEFAULT_STACK_PERMS,
323	#ifdef _LIBC_REENTRANT
324	._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
325	._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
326	#endif
327	._dl_nns = `1`,
328	._dl_ns =
329	{
330	#ifdef _LIBC_REENTRANT
331	[LM_ID_BASE] = { ._ns_unique_sym_table
332	= { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
333	#endif
334	}
335	};
336	/ If we would use strong_alias here the compiler would see a*
337	non-hidden definition. This would undo the effect of the previous
338	declaration. So spell out what strong_alias does plus add the
339	visibility attribute. /*
340	extern struct rtld_global _rtld_local
341	__attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
342
343
344	/ This variable is similar to _rtld_local, but all values are*
345	read-only after relocation. /*
346	struct rtld_global_ro _rtld_global_ro attribute_relro =
347	{
348	/ Get architecture specific initializer. /
349	#include <dl-procinfo.c>
350	#ifdef NEED_DL_SYSINFO
351	._dl_sysinfo = DL_SYSINFO_DEFAULT,
352	#endif
353	._dl_debug_fd = STDERR_FILENO,
354	._dl_use_load_bias = -`2`,
355	._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
356	#if !HAVE_TUNABLES
357	._dl_hwcap_mask = HWCAP_IMPORTANT,
358	#endif
359	._dl_lazy = `1`,
360	._dl_fpu_control = _FPU_DEFAULT,
361	._dl_pagesize = EXEC_PAGESIZE,
362	._dl_inhibit_cache = `0`,
363
364	/ Function pointers. /
365	._dl_debug_printf = _dl_debug_printf,
366	._dl_mcount = _dl_mcount,
367	._dl_lookup_symbol_x = _dl_lookup_symbol_x,
368	._dl_open = _dl_open,
369	._dl_close = _dl_close,
370	._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
371	#ifdef HAVE_DL_DISCOVER_OSVERSION
372	._dl_discover_osversion = _dl_discover_osversion
373	#endif
374	};
375	/ If we would use strong_alias here the compiler would see a*
376	non-hidden definition. This would undo the effect of the previous
377	declaration. So spell out was strong_alias does plus add the
378	visibility attribute. /*
379	extern struct rtld_global_ro _rtld_local_ro
380	__attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
381
382
383	static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
384	ElfW(Addr) user_entry, ElfW(auxv_t) auxv);
385
386	/ These two variables cannot be moved into .data.rel.ro. /
387	static struct libname_list _dl_rtld_libname;
388	static struct libname_list _dl_rtld_libname2;
389
390	/ Variable for statistics. /
391	RLTD_TIMING_DECLARE (relocate_time, static);
392	RLTD_TIMING_DECLARE (load_time, static, attribute_relro);
393	RLTD_TIMING_DECLARE (start_time, static, attribute_relro);
394
395	/ Additional definitions needed by TLS initialization. /
396	#ifdef TLS_INIT_HELPER
397	TLS_INIT_HELPER
398	#endif
399
400	/ Helper function for syscall implementation. /
401	#ifdef DL_SYSINFO_IMPLEMENTATION
402	DL_SYSINFO_IMPLEMENTATION
403	#endif
404
405	/ Before ld.so is relocated we must not access variables which need*
406	relocations. This means variables which are exported. Variables
407	declared as static are fine. If we can mark a variable hidden this
408	is fine, too. The latter is important here. We can avoid setting
409	up a temporary link map for ld.so if we can mark _rtld_global as
410	hidden. /*
411	#ifdef PI_STATIC_AND_HIDDEN
412	# define DONT_USE_BOOTSTRAP_MAP 1
413	#endif
414
415	#ifdef DONT_USE_BOOTSTRAP_MAP
416	static ElfW(Addr) _dl_start_final (void *arg);
417	#else
418	struct dl_start_final_info
419	{
420	struct link_map l;
421	RTLD_TIMING_VAR (start_time);
422	};
423	static ElfW(Addr) _dl_start_final (void *arg,
424	struct dl_start_final_info *info);
425	#endif
426
427	/ These defined magically in the linker script. /
428	extern char _begin[] attribute_hidden;
429	extern char _etext[] attribute_hidden;
430	extern char _end[] attribute_hidden;
431
432
433	#ifdef RTLD_START
434	RTLD_START
435	#else
436	# error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
437	#endif
438
439	/ This is the second half of _dl_start (below). It can be inlined safely*
440	under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
441	references. When the tools don't permit us to avoid using a GOT entry
442	for _dl_rtld_global (no attribute_hidden support), we must make sure
443	this function is not inlined (see below). /*
444
445	#ifdef DONT_USE_BOOTSTRAP_MAP
446	static inline ElfW(Addr) __attribute__ ((always_inline))
447	_dl_start_final (void *arg)
448	#else
449	static ElfW(Addr) __attribute__ ((noinline))
450	_dl_start_final (void arg, struct* dl_start_final_info *info)
451	#endif
452	{
453	ElfW(Addr) start_addr;
454
455	/ If it hasn't happen yet record the startup time. /
456	rtld_timer_start (&start_time);
457	#if !defined DONT_USE_BOOTSTRAP_MAP
458	RTLD_TIMING_SET (start_time, info->start_time);
459	#endif
460
461	/ Transfer data about ourselves to the permanent link_map structure. /
462	#ifndef DONT_USE_BOOTSTRAP_MAP
463	GL(dl_rtld_map).l_addr = info->l.l_addr;
464	GL(dl_rtld_map).l_ld = info->l.l_ld;
465	memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
466	sizeof GL(dl_rtld_map).l_info);
467	GL(dl_rtld_map).l_mach = info->l.l_mach;
468	GL(dl_rtld_map).l_relocated = `1`;
469	#endif
470	_dl_setup_hash (&GL(dl_rtld_map));
471	GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
472	GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
473	GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
474	GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
475	/ Copy the TLS related data if necessary. /
476	#ifndef DONT_USE_BOOTSTRAP_MAP
477	# if NO_TLS_OFFSET != 0
478	GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
479	# endif
480	#endif
481
482	/ Initialize the stack end variable. /
483	__libc_stack_end = __builtin_frame_address (`0`);
484
485	/ Call the OS-dependent function to set up life so we can do things like*
486	file access. It will call `dl_main' (below) to do all the real work
487	of the dynamic linker, and then unwind our frame and run the user
488	entry point on the same stack we entered on. /*
489	start_addr = _dl_sysdep_start (arg, &dl_main);
490
491	if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS))
492	{
493	RTLD_TIMING_VAR (rtld_total_time);
494	rtld_timer_stop (&rtld_total_time, start_time);
495	print_statistics (RTLD_TIMING_REF(rtld_total_time));
496	}
497
498	return start_addr;
499	}
500
501	static ElfW(Addr) __attribute_used__
502	_dl_start (void *arg)
503	{
504	#ifdef DONT_USE_BOOTSTRAP_MAP
505	# define bootstrap_map GL(dl_rtld_map)
506	#else
507	struct dl_start_final_info info;
508	# define bootstrap_map info.l
509	#endif
510
511	/ This #define produces dynamic linking inline functions for*
512	bootstrap relocation instead of general-purpose relocation.
513	Since ld.so must not have any undefined symbols the result
514	is trivial: always the map of ld.so itself. /*
515	#define RTLD_BOOTSTRAP
516	#define BOOTSTRAP_MAP (&bootstrap_map)
517	#define RESOLVE_MAP(sym, version, flags) BOOTSTRAP_MAP
518	#include "dynamic-link.h"
519
520	#ifdef DONT_USE_BOOTSTRAP_MAP
521	rtld_timer_start (&start_time);
522	#else
523	rtld_timer_start (&info.start_time);
524	#endif
525
526	/ Partly clean the `bootstrap_map' structure up. Don't use*
527	`memset' since it might not be built in or inlined and we cannot
528	make function calls at this point. Use '__builtin_memset' if we
529	know it is available. We do not have to clear the memory if we
530	do not have to use the temporary bootstrap_map. Global variables
531	are initialized to zero by default. /*
532	#ifndef DONT_USE_BOOTSTRAP_MAP
533	# ifdef HAVE_BUILTIN_MEMSET
534	__builtin_memset (bootstrap_map.l_info, `'\0'`, sizeof (bootstrap_map.l_info));
535	# else
536	for (size_t cnt = `0`;
537	cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[`0`]);
538	++cnt)
539	bootstrap_map.l_info[cnt] = `0`;
540	# endif
541	#endif
542
543	/ Figure out the run-time load address of the dynamic linker itself. /
544	bootstrap_map.l_addr = elf_machine_load_address ();
545
546	/ Read our own dynamic section and fill in the info array. /
547	bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
548	elf_get_dynamic_info (&bootstrap_map, NULL);
549
550	#if NO_TLS_OFFSET != 0
551	bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
552	#endif
553
554	#ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
555	ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
556	#endif
557
558	if (bootstrap_map.l_addr \|\| ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
559	{
560	/ Relocate ourselves so we can do normal function calls and*
561	data access using the global offset table. /*
562
563	ELF_DYNAMIC_RELOCATE (&bootstrap_map, `0`, `0`, `0`);
564	}
565	bootstrap_map.l_relocated = `1`;
566
567	/ Please note that we don't allow profiling of this object and*
568	therefore need not test whether we have to allocate the array
569	for the relocation results (as done in dl-reloc.c). /*
570
571	/ Now life is sane; we can call functions and access global data.*
572	Set up to use the operating system facilities, and find out from
573	the operating system's program loader where to find the program
574	header table in core. Put the rest of _dl_start into a separate
575	function, that way the compiler cannot put accesses to the GOT
576	before ELF_DYNAMIC_RELOCATE. /*
577
578	__rtld_malloc_init_stubs ();
579
580	{
581	#ifdef DONT_USE_BOOTSTRAP_MAP
582	ElfW(Addr) entry = _dl_start_final (arg);
583	#else
584	ElfW(Addr) entry = _dl_start_final (arg, &info);
585	#endif
586
587	#ifndef ELF_MACHINE_START_ADDRESS
588	# define ELF_MACHINE_START_ADDRESS(map, start) (start)
589	#endif
590
591	return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
592	}
593	}
594
595
596
597	/ Now life is peachy; we can do all normal operations.*
598	On to the real work. /*
599
600	/ Some helper functions. /
601
602	/ Arguments to relocate_doit. /
603	struct relocate_args
604	{
605	struct link_map *l;
606	int reloc_mode;
607	};
608
609	struct map_args
610	{
611	/ Argument to map_doit. /
612	const char *str;
613	struct link_map *loader;
614	int mode;
615	/ Return value of map_doit. /
616	struct link_map *map;
617	};
618
619	struct dlmopen_args
620	{
621	const char *fname;
622	struct link_map *map;
623	};
624
625	struct lookup_args
626	{
627	const char *name;
628	struct link_map *map;
629	void *result;
630	};
631
632	/ Arguments to version_check_doit. /
633	struct version_check_args
634	{
635	int doexit;
636	int dotrace;
637	};
638
639	static void
640	relocate_doit (void *a)
641	{
642	struct relocate_args args = (struct* relocate_args *) a;
643
644	_dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, `0`);
645	}
646
647	static void
648	map_doit (void *a)
649	{
650	struct map_args args = (struct* map_args *) a;
651	int type = (args->mode == __RTLD_OPENEXEC) ? lt_executable : lt_library;
652	args->map = _dl_map_object (args->loader, args->str, type, `0`,
653	args->mode, LM_ID_BASE);
654	}
655
656	static void
657	dlmopen_doit (void *a)
658	{
659	struct dlmopen_args args = (struct* dlmopen_args *) a;
660	args->map = _dl_open (args->fname,
661	(RTLD_LAZY \| __RTLD_DLOPEN \| __RTLD_AUDIT
662	\| __RTLD_SECURE),
663	dl_main, LM_ID_NEWLM, _dl_argc, _dl_argv,
664	__environ);
665	}
666
667	static void
668	lookup_doit (void *a)
669	{
670	struct lookup_args args = (struct* lookup_args *) a;
671	const ElfW(Sym) *ref = NULL;
672	args->result = NULL;
673	lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
674	args->map->l_local_scope, NULL, `0`,
675	DL_LOOKUP_RETURN_NEWEST, NULL);
676	if (ref != NULL)
677	args->result = DL_SYMBOL_ADDRESS (l, ref);
678	}
679
680	static void
681	version_check_doit (void *a)
682	{
683	struct version_check_args args = (struct* version_check_args *) a;
684	if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, `1`,
685	args->dotrace) && args->doexit)
686	/ We cannot start the application. Abort now. /
687	_exit (`1`);
688	}
689
690
691	static inline struct link_map *
692	find_needed (const char *name)
693	{
694	struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
695	unsigned int n = scope->r_nlist;
696
697	while (n-- > `0`)
698	if (_dl_name_match_p (name, scope->r_list[n]))
699	return scope->r_list[n];
700
701	/ Should never happen. /
702	return NULL;
703	}
704
705	static int
706	match_version (const char string, struct* link_map *map)
707	{
708	const char strtab = (const* void *) D_PTR (map, l_info[DT_STRTAB]);
709	ElfW(Verdef) *def;
710
711	#define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
712	if (map->l_info[VERDEFTAG] == NULL)
713	/ The file has no symbol versioning. /
714	return `0`;
715
716	def = (ElfW(Verdef) ) ((char* *) map->l_addr
717	+ map->l_info[VERDEFTAG]->d_un.d_ptr);
718	while (`1`)
719	{
720	ElfW(Verdaux) aux = (ElfW(Verdaux) ) ((char *) def + def->vd_aux);
721
722	/ Compare the version strings. /
723	if (strcmp (string, strtab + aux->vda_name) == `0`)
724	/ Bingo! /
725	return `1`;
726
727	/ If no more definitions we failed to find what we want. /
728	if (def->vd_next == `0`)
729	break;
730
731	/ Next definition. /
732	def = (ElfW(Verdef) ) ((char* *) def + def->vd_next);
733	}
734
735	return `0`;
736	}
737
738	static bool tls_init_tp_called;
739
740	static void *
741	init_tls (size_t naudit)
742	{
743	/ Number of elements in the static TLS block. /
744	GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
745
746	/ Do not do this twice. The audit interface might have required*
747	the DTV interfaces to be set up early. /*
748	if (GL(dl_initial_dtv) != NULL)
749	return NULL;
750
751	/ Allocate the array which contains the information about the*
752	dtv slots. We allocate a few entries more than needed to
753	avoid the need for reallocation. /*
754	size_t nelem = GL(dl_tls_max_dtv_idx) + `1` + TLS_SLOTINFO_SURPLUS;
755
756	/ Allocate. /
757	GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
758	calloc (sizeof (struct dtv_slotinfo_list)
759	+ nelem * sizeof (struct dtv_slotinfo), `1`);
760	/ No need to check the return value. If memory allocation failed*
761	the program would have been terminated. /*
762
763	struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
764	GL(dl_tls_dtv_slotinfo_list)->len = nelem;
765	GL(dl_tls_dtv_slotinfo_list)->next = NULL;
766
767	/ Fill in the information from the loaded modules. No namespace*
768	but the base one can be filled at this time. /*
769	assert (GL(dl_ns)[LM_ID_BASE + `1`]._ns_loaded == NULL);
770	int i = `0`;
771	for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
772	l = l->l_next)
773	if (l->l_tls_blocksize != `0`)
774	{
775	/ This is a module with TLS data. Store the map reference.*
776	The generation counter is zero. /*
777	slotinfo[i].map = l;
778	/ slotinfo[i].gen = 0; /
779	++i;
780	}
781	assert (i == GL(dl_tls_max_dtv_idx));
782
783	/ Calculate the size of the static TLS surplus. /
784	_dl_tls_static_surplus_init (naudit);
785
786	/ Compute the TLS offsets for the various blocks. /
787	_dl_determine_tlsoffset ();
788
789	/ Construct the static TLS block and the dtv for the initial*
790	thread. For some platforms this will include allocating memory
791	for the thread descriptor. The memory for the TLS block will
792	never be freed. It should be allocated accordingly. The dtv
793	array can be changed if dynamic loading requires it. /*
794	void *tcbp = _dl_allocate_tls_storage ();
795	if (tcbp == NULL)
796	_dl_fatal_printf ("\
797	cannot allocate TLS data structures for initial thread\n");
798
799	/ Store for detection of the special case by __tls_get_addr*
800	so it knows not to pass this dtv to the normal realloc. /*
801	GL(dl_initial_dtv) = GET_DTV (tcbp);
802
803	/ And finally install it for the main thread. /
804	const char *lossage = TLS_INIT_TP (tcbp);
805	if (__glibc_unlikely (lossage != NULL))
806	_dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
807	#if THREAD_GSCOPE_IN_TCB
808	list_add (&THREAD_SELF->list, &GL (dl_stack_user));
809	#endif
810	tls_init_tp_called = true;
811
812	return tcbp;
813	}
814
815	static unsigned int
816	do_preload (const char fname, struct* link_map main_map, const* char *where)
817	{
818	const char *objname;
819	const char *err_str = NULL;
820	struct map_args args;
821	bool malloced;
822
823	args.str = fname;
824	args.loader = main_map;
825	args.mode = __RTLD_SECURE;
826
827	unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
828
829	(void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
830	if (__glibc_unlikely (err_str != NULL))
831	{
832	_dl_error_printf ("\
833	ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n",
834	fname, where, err_str);
835	/ No need to call free, this is still before*
836	the libc's malloc is used. /*
837	}
838	else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
839	/ It is no duplicate. /
840	return `1`;
841
842	/ Nothing loaded. /
843	return `0`;
844	}
845
846	#if defined SHARED && defined _LIBC_REENTRANT \
847	&& defined __rtld_lock_default_lock_recursive
848	static void
849	rtld_lock_default_lock_recursive (void *lock)
850	{
851	__rtld_lock_default_lock_recursive (lock);
852	}
853
854	static void
855	rtld_lock_default_unlock_recursive (void *lock)
856	{
857	__rtld_lock_default_unlock_recursive (lock);
858	}
859	#endif
860
861
862	static void
863	security_init (void)
864	{
865	/ Set up the stack checker's canary. /
866	uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
867	#ifdef THREAD_SET_STACK_GUARD
868	THREAD_SET_STACK_GUARD (stack_chk_guard);
869	#else
870	__stack_chk_guard = stack_chk_guard;
871	#endif
872
873	/ Set up the pointer guard as well, if necessary. /
874	uintptr_t pointer_chk_guard
875	= _dl_setup_pointer_guard (_dl_random, stack_chk_guard);
876	#ifdef THREAD_SET_POINTER_GUARD
877	THREAD_SET_POINTER_GUARD (pointer_chk_guard);
878	#endif
879	__pointer_chk_guard_local = pointer_chk_guard;
880
881	/ We do not need the _dl_random value anymore. The less*
882	information we leave behind, the better, so clear the
883	variable. /*
884	_dl_random = NULL;
885	}
886
887	#include <setup-vdso.h>
888
889	/ The LD_PRELOAD environment variable gives list of libraries*
890	separated by white space or colons that are loaded before the
891	executable's dependencies and prepended to the global scope list.
892	(If the binary is running setuid all elements containing a '/' are
893	ignored since it is insecure.) Return the number of preloads
894	performed. Ditto for --preload command argument. /*
895	unsigned int
896	handle_preload_list (const char preloadlist, struct* link_map *main_map,
897	const char *where)
898	{
899	unsigned int npreloads = `0`;
900	const char *p = preloadlist;
901	char fname[SECURE_PATH_LIMIT];
902
903	while (*p != `'\0'`)
904	{
905	/ Split preload list at space/colon. /
906	size_t len = strcspn (p, " :");
907	if (len > `0` && len < sizeof (fname))
908	{
909	memcpy (fname, p, len);
910	fname[len] = `'\0'`;
911	}
912	else
913	fname[`0`] = `'\0'`;
914
915	/ Skip over the substring and the following delimiter. /
916	p += len;
917	if (*p != `'\0'`)
918	++p;
919
920	if (dso_name_valid_for_suid (fname))
921	npreloads += do_preload (fname, main_map, where);
922	}
923	return npreloads;
924	}
925
926	/ Called if the audit DSO cannot be used: if it does not have the*
927	appropriate interfaces, or it expects a more recent version library
928	version than what the dynamic linker provides. /*
929	static void
930	unload_audit_module (struct link_map map, int* original_tls_idx)
931	{
932	#ifndef NDEBUG
933	Lmid_t ns = map->l_ns;
934	#endif
935	_dl_close (map);
936
937	/ Make sure the namespace has been cleared entirely. /
938	assert (GL(dl_ns)[ns]._ns_loaded == NULL);
939	assert (GL(dl_ns)[ns]._ns_nloaded == `0`);
940
941	GL(dl_tls_max_dtv_idx) = original_tls_idx;
942	}
943
944	/ Called to print an error message if loading of an audit module*
945	failed. /*
946	static void
947	report_audit_module_load_error (const char name, const* char *err_str,
948	bool malloced)
949	{
950	_dl_error_printf ("\
951	ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
952	name, err_str);
953	if (malloced)
954	free ((char *) err_str);
955	}
956
957	/ Load one audit module. /
958	static void
959	load_audit_module (const char name, struct* audit_ifaces **last_audit)
960	{
961	int original_tls_idx = GL(dl_tls_max_dtv_idx);
962
963	struct dlmopen_args dlmargs;
964	dlmargs.fname = name;
965	dlmargs.map = NULL;
966
967	const char *objname;
968	const char *err_str = NULL;
969	bool malloced;
970	_dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, &dlmargs);
971	if (__glibc_unlikely (err_str != NULL))
972	{
973	report_audit_module_load_error (name, err_str, malloced);
974	return;
975	}
976
977	struct lookup_args largs;
978	largs.name = "la_version";
979	largs.map = dlmargs.map;
980	_dl_catch_error (&objname, &err_str, &malloced, lookup_doit, &largs);
981	if (__glibc_likely (err_str != NULL))
982	{
983	unload_audit_module (dlmargs.map, original_tls_idx);
984	report_audit_module_load_error (name, err_str, malloced);
985	return;
986	}
987
988	unsigned int (laversion) (unsigned* int) = largs.result;
989
990	/ A null symbol indicates that something is very wrong with the*
991	loaded object because defined symbols are supposed to have a
992	valid, non-null address. /*
993	assert (laversion != NULL);
994
995	unsigned int lav = laversion (LAV_CURRENT);
996	if (lav == `0`)
997	{
998	/ Only print an error message if debugging because this can*
999	happen deliberately. /*
1000	if (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
1001	_dl_debug_printf ("\
1002	file=%s [%lu]; audit interface function la_version returned zero; ignored.\n",
1003	dlmargs.map->l_name, dlmargs.map->l_ns);
1004	unload_audit_module (dlmargs.map, original_tls_idx);
1005	return;
1006	}
1007
1008	if (lav > LAV_CURRENT)
1009	{
1010	_dl_debug_printf ("\
1011	ERROR: audit interface '%s' requires version %d (maximum supported version %d); ignored.\n",
1012	name, lav, LAV_CURRENT);
1013	unload_audit_module (dlmargs.map, original_tls_idx);
1014	return;
1015	}
1016
1017	enum { naudit_ifaces = `8` };
1018	union
1019	{
1020	struct audit_ifaces ifaces;
1021	void (fptr[naudit_ifaces]) (void*);
1022	} newp = malloc (sizeof* (*newp));
1023	if (newp == NULL)
1024	_dl_fatal_printf ("Out of memory while loading audit modules\n");
1025
1026	/ Names of the auditing interfaces. All in one*
1027	long string. /*
1028	static const char audit_iface_names[] =
1029	"la_activity\0"
1030	"la_objsearch\0"
1031	"la_objopen\0"
1032	"la_preinit\0"
1033	#if __ELF_NATIVE_CLASS == 32
1034	"la_symbind32\0"
1035	#elif __ELF_NATIVE_CLASS == 64
1036	"la_symbind64\0"
1037	#else
1038	# error "__ELF_NATIVE_CLASS must be defined"
1039	#endif
1040	#define STRING(s) __STRING (s)
1041	"la_" STRING (ARCH_LA_PLTENTER) "\0"
1042	"la_" STRING (ARCH_LA_PLTEXIT) "\0"
1043	"la_objclose\0";
1044	unsigned int cnt = `0`;
1045	const char *cp = audit_iface_names;
1046	do
1047	{
1048	largs.name = cp;
1049	_dl_catch_error (&objname, &err_str, &malloced, lookup_doit, &largs);
1050
1051	/ Store the pointer. /
1052	if (err_str == NULL && largs.result != NULL)
1053	newp->fptr[cnt] = largs.result;
1054	else
1055	newp->fptr[cnt] = NULL;
1056	++cnt;
1057
1058	cp = rawmemchr (cp, `'\0'`) + `1`;
1059	}
1060	while (*cp != `'\0'`);
1061	assert (cnt == naudit_ifaces);
1062
1063	/ Now append the new auditing interface to the list. /
1064	newp->ifaces.next = NULL;
1065	if (*last_audit == NULL)
1066	*last_audit = GLRO(dl_audit) = &newp->ifaces;
1067	else
1068	last_audit = (last_audit)->next = &newp->ifaces;
1069
1070	/ The dynamic linker link map is statically allocated, so the*
1071	cookie in _dl_new_object has not happened. /*
1072	link_map_audit_state (&GL (dl_rtld_map), GLRO (dl_naudit))->cookie
1073	= (intptr_t) &GL (dl_rtld_map);
1074
1075	++GLRO(dl_naudit);
1076
1077	/ Mark the DSO as being used for auditing. /
1078	dlmargs.map->l_auditing = `1`;
1079	}
1080
1081	/ Notify the the audit modules that the object MAP has already been*
1082	loaded. /*
1083	static void
1084	notify_audit_modules_of_loaded_object (struct link_map *map)
1085	{
1086	struct audit_ifaces *afct = GLRO(dl_audit);
1087	for (unsigned int cnt = `0`; cnt < GLRO(dl_naudit); ++cnt)
1088	{
1089	if (afct->objopen != NULL)
1090	{
1091	struct auditstate *state = link_map_audit_state (map, cnt);
1092	state->bindflags = afct->objopen (map, LM_ID_BASE, &state->cookie);
1093	map->l_audit_any_plt \|= state->bindflags != `0`;
1094	}
1095
1096	afct = afct->next;
1097	}
1098	}
1099
1100	/ Load all audit modules. /
1101	static void
1102	load_audit_modules (struct link_map main_map, struct* audit_list *audit_list)
1103	{
1104	struct audit_ifaces *last_audit = NULL;
1105
1106	while (true)
1107	{
1108	const char *name = audit_list_next (audit_list);
1109	if (name == NULL)
1110	break;
1111	load_audit_module (name, &last_audit);
1112	}
1113
1114	/ Notify audit modules of the initially loaded modules (the main*
1115	program and the dynamic linker itself). /*
1116	if (GLRO(dl_naudit) > `0`)
1117	{
1118	notify_audit_modules_of_loaded_object (main_map);
1119	notify_audit_modules_of_loaded_object (&GL(dl_rtld_map));
1120	}
1121	}
1122
1123	static void
1124	dl_main (const ElfW(Phdr) *phdr,
1125	ElfW(Word) phnum,
1126	ElfW(Addr) *user_entry,
1127	ElfW(auxv_t) *auxv)
1128	{
1129	const ElfW(Phdr) *ph;
1130	struct link_map *main_map;
1131	size_t file_size;
1132	char *file;
1133	bool has_interp = false;
1134	unsigned int i;
1135	bool prelinked = false;
1136	bool rtld_is_main = false;
1137	void *tcbp = NULL;
1138
1139	struct dl_main_state state;
1140	dl_main_state_init (&state);
1141
1142	GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
1143
1144	#if defined SHARED && defined _LIBC_REENTRANT \
1145	&& defined __rtld_lock_default_lock_recursive
1146	GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
1147	GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
1148	#endif
1149
1150	#if THREAD_GSCOPE_IN_TCB
1151	INIT_LIST_HEAD (&GL (dl_stack_used));
1152	INIT_LIST_HEAD (&GL (dl_stack_user));
1153	#endif
1154
1155	/ The explicit initialization here is cheaper than processing the reloc*
1156	in the _rtld_local definition's initializer. /*
1157	GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
1158
1159	/ Process the environment variable which control the behaviour. /
1160	process_envvars (&state);
1161
1162	#ifndef HAVE_INLINED_SYSCALLS
1163	/ Set up a flag which tells we are just starting. /
1164	_dl_starting_up = `1`;
1165	#endif
1166
1167	const char *ld_so_name = _dl_argv[`0`];
1168	if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
1169	{
1170	/ Ho ho. We are not the program interpreter! We are the program*
1171	itself! This means someone ran ld.so as a command. Well, that
1172	might be convenient to do sometimes. We support it by
1173	interpreting the args like this:
1174
1175	ld.so PROGRAM ARGS...
1176
1177	The first argument is the name of a file containing an ELF
1178	executable we will load and run with the following arguments.
1179	To simplify life here, PROGRAM is searched for using the
1180	normal rules for shared objects, rather than $PATH or anything
1181	like that. We just load it and use its entry point; we don't
1182	pay attention to its PT_INTERP command (we are the interpreter
1183	ourselves). This is an easy way to test a new ld.so before
1184	installing it. /*
1185	rtld_is_main = true;
1186
1187	char *argv0 = NULL;
1188
1189	/ Note the place where the dynamic linker actually came from. /
1190	GL(dl_rtld_map).l_name = rtld_progname;
1191
1192	while (_dl_argc > `1`)
1193	if (! strcmp (_dl_argv[`1`], "--list"))
1194	{
1195	if (state.mode != rtld_mode_help)
1196	{
1197	state.mode = rtld_mode_list;
1198	/ This means do no dependency analysis. /
1199	GLRO(dl_lazy) = -`1`;
1200	}
1201
1202	++_dl_skip_args;
1203	--_dl_argc;
1204	++_dl_argv;
1205	}
1206	else if (! strcmp (_dl_argv[`1`], "--verify"))
1207	{
1208	if (state.mode != rtld_mode_help)
1209	state.mode = rtld_mode_verify;
1210
1211	++_dl_skip_args;
1212	--_dl_argc;
1213	++_dl_argv;
1214	}
1215	else if (! strcmp (_dl_argv[`1`], "--inhibit-cache"))
1216	{
1217	GLRO(dl_inhibit_cache) = `1`;
1218	++_dl_skip_args;
1219	--_dl_argc;
1220	++_dl_argv;
1221	}
1222	else if (! strcmp (_dl_argv[`1`], "--library-path")
1223	&& _dl_argc > `2`)
1224	{
1225	state.library_path = _dl_argv[`2`];
1226	state.library_path_source = "--library-path";
1227
1228	_dl_skip_args += `2`;
1229	_dl_argc -= `2`;
1230	_dl_argv += `2`;
1231	}
1232	else if (! strcmp (_dl_argv[`1`], "--inhibit-rpath")
1233	&& _dl_argc > `2`)
1234	{
1235	GLRO(dl_inhibit_rpath) = _dl_argv[`2`];
1236
1237	_dl_skip_args += `2`;
1238	_dl_argc -= `2`;
1239	_dl_argv += `2`;
1240	}
1241	else if (! strcmp (_dl_argv[`1`], "--audit") && _dl_argc > `2`)
1242	{
1243	audit_list_add_string (&state.audit_list, _dl_argv[`2`]);
1244
1245	_dl_skip_args += `2`;
1246	_dl_argc -= `2`;
1247	_dl_argv += `2`;
1248	}
1249	else if (! strcmp (_dl_argv[`1`], "--preload") && _dl_argc > `2`)
1250	{
1251	state.preloadarg = _dl_argv[`2`];
1252	_dl_skip_args += `2`;
1253	_dl_argc -= `2`;
1254	_dl_argv += `2`;
1255	}
1256	else if (! strcmp (_dl_argv[`1`], "--argv0") && _dl_argc > `2`)
1257	{
1258	argv0 = _dl_argv[`2`];
1259
1260	_dl_skip_args += `2`;
1261	_dl_argc -= `2`;
1262	_dl_argv += `2`;
1263	}
1264	else if (strcmp (_dl_argv[`1`], "--glibc-hwcaps-prepend") == `0`
1265	&& _dl_argc > `2`)
1266	{
1267	state.glibc_hwcaps_prepend = _dl_argv[`2`];
1268	_dl_skip_args += `2`;
1269	_dl_argc -= `2`;
1270	_dl_argv += `2`;
1271	}
1272	else if (strcmp (_dl_argv[`1`], "--glibc-hwcaps-mask") == `0`
1273	&& _dl_argc > `2`)
1274	{
1275	state.glibc_hwcaps_mask = _dl_argv[`2`];
1276	_dl_skip_args += `2`;
1277	_dl_argc -= `2`;
1278	_dl_argv += `2`;
1279	}
1280	#if HAVE_TUNABLES
1281	else if (! strcmp (_dl_argv[`1`], "--list-tunables"))
1282	{
1283	state.mode = rtld_mode_list_tunables;
1284
1285	++_dl_skip_args;
1286	--_dl_argc;
1287	++_dl_argv;
1288	}
1289	#endif
1290	else if (strcmp (_dl_argv[`1`], "--help") == `0`)
1291	{
1292	state.mode = rtld_mode_help;
1293	--_dl_argc;
1294	++_dl_argv;
1295	}
1296	else if (strcmp (_dl_argv[`1`], "--version") == `0`)
1297	_dl_version ();
1298	else if (_dl_argv[`1`][`0`] == `'-'` && _dl_argv[`1`][`1`] == `'-'`)
1299	{
1300	if (_dl_argv[`1`][`1`] == `'\0'`)
1301	/ End of option list. /
1302	break;
1303	else
1304	/ Unrecognized option. /
1305	_dl_usage (ld_so_name, _dl_argv[`1`]);
1306	}
1307	else
1308	break;
1309
1310	#if HAVE_TUNABLES
1311	if (__glibc_unlikely (state.mode == rtld_mode_list_tunables))
1312	{
1313	__tunables_print ();
1314	_exit (`0`);
1315	}
1316	#endif
1317
1318	/ If we have no further argument the program was called incorrectly.*
1319	Grant the user some education. /*
1320	if (_dl_argc < `2`)
1321	{
1322	if (state.mode == rtld_mode_help)
1323	/ --help without an executable is not an error. /
1324	_dl_help (ld_so_name, &state);
1325	else
1326	_dl_usage (ld_so_name, NULL);
1327	}
1328
1329	++_dl_skip_args;
1330	--_dl_argc;
1331	++_dl_argv;
1332
1333	/ The initialization of _dl_stack_flags done below assumes the*
1334	executable's PT_GNU_STACK may have been honored by the kernel, and
1335	so a PT_GNU_STACK with PF_X set means the stack started out with
1336	execute permission. However, this is not really true if the
1337	dynamic linker is the executable the kernel loaded. For this
1338	case, we must reinitialize _dl_stack_flags to match the dynamic
1339	linker itself. If the dynamic linker was built with a
1340	PT_GNU_STACK, then the kernel may have loaded us with a
1341	nonexecutable stack that we will have to make executable when we
1342	load the program below unless it has a PT_GNU_STACK indicating
1343	nonexecutable stack is ok. /*
1344
1345	for (ph = phdr; ph < &phdr[phnum]; ++ph)
1346	if (ph->p_type == PT_GNU_STACK)
1347	{
1348	GL(dl_stack_flags) = ph->p_flags;
1349	break;
1350	}
1351
1352	if (__glibc_unlikely (state.mode == rtld_mode_verify
1353	\|\| state.mode == rtld_mode_help))
1354	{
1355	const char *objname;
1356	const char *err_str = NULL;
1357	struct map_args args;
1358	bool malloced;
1359
1360	args.str = rtld_progname;
1361	args.loader = NULL;
1362	args.mode = __RTLD_OPENEXEC;
1363	(void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
1364	&args);
1365	if (__glibc_unlikely (err_str != NULL))
1366	{
1367	/ We don't free the returned string, the programs stops*
1368	anyway. /*
1369	if (state.mode == rtld_mode_help)
1370	/ Mask the failure to load the main object. The help*
1371	message contains less information in this case. /*
1372	_dl_help (ld_so_name, &state);
1373	else
1374	_exit (EXIT_FAILURE);
1375	}
1376	}
1377	else
1378	{
1379	RTLD_TIMING_VAR (start);
1380	rtld_timer_start (&start);
1381	_dl_map_object (NULL, rtld_progname, lt_executable, `0`,
1382	__RTLD_OPENEXEC, LM_ID_BASE);
1383	rtld_timer_stop (&load_time, start);
1384	}
1385
1386	/ Now the map for the main executable is available. /
1387	main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
1388
1389	if (__glibc_likely (state.mode == rtld_mode_normal)
1390	&& GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1391	&& main_map->l_info[DT_SONAME] != NULL
1392	&& strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1393	+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val,
1394	(const char *) D_PTR (main_map, l_info[DT_STRTAB])
1395	+ main_map->l_info[DT_SONAME]->d_un.d_val) == `0`)
1396	_dl_fatal_printf ("loader cannot load itself\n");
1397
1398	phdr = main_map->l_phdr;
1399	phnum = main_map->l_phnum;
1400	/ We overwrite here a pointer to a malloc()ed string. But since*
1401	the malloc() implementation used at this point is the dummy
1402	implementations which has no real free() function it does not
1403	makes sense to free the old string first. /*
1404	main_map->l_name = (char *) "";
1405	*user_entry = main_map->l_entry;
1406
1407	#ifdef HAVE_AUX_VECTOR
1408	/ Adjust the on-stack auxiliary vector so that it looks like the*
1409	binary was executed directly. /*
1410	for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
1411	switch (av->a_type)
1412	{
1413	case AT_PHDR:
1414	av->a_un.a_val = (uintptr_t) phdr;
1415	break;
1416	case AT_PHNUM:
1417	av->a_un.a_val = phnum;
1418	break;
1419	case AT_ENTRY:
1420	av->a_un.a_val = *user_entry;
1421	break;
1422	case AT_EXECFN:
1423	av->a_un.a_val = (uintptr_t) _dl_argv[`0`];
1424	break;
1425	}
1426	#endif
1427
1428	/ Set the argv[0] string now that we've processed the executable. /
1429	if (argv0 != NULL)
1430	_dl_argv[`0`] = argv0;
1431	}
1432	else
1433	{
1434	/ Create a link_map for the executable itself.*
1435	This will be what dlopen on "" returns. /*
1436	main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
1437	__RTLD_OPENEXEC, LM_ID_BASE);
1438	assert (main_map != NULL);
1439	main_map->l_phdr = phdr;
1440	main_map->l_phnum = phnum;
1441	main_map->l_entry = *user_entry;
1442
1443	/ Even though the link map is not yet fully initialized we can add*
1444	it to the map list since there are no possible users running yet. /*
1445	_dl_add_to_namespace_list (main_map, LM_ID_BASE);
1446	assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
1447
1448	/ At this point we are in a bit of trouble. We would have to*
1449	fill in the values for l_dev and l_ino. But in general we
1450	do not know where the file is. We also do not handle AT_EXECFD
1451	even if it would be passed up.
1452
1453	We leave the values here defined to 0. This is normally no
1454	problem as the program code itself is normally no shared
1455	object and therefore cannot be loaded dynamically. Nothing
1456	prevent the use of dynamic binaries and in these situations
1457	we might get problems. We might not be able to find out
1458	whether the object is already loaded. But since there is no
1459	easy way out and because the dynamic binary must also not
1460	have an SONAME we ignore this program for now. If it becomes
1461	a problem we can force people using SONAMEs. /*
1462
1463	/ We delay initializing the path structure until we got the dynamic*
1464	information for the program. /*
1465	}
1466
1467	main_map->l_map_end = `0`;
1468	main_map->l_text_end = `0`;
1469	/ Perhaps the executable has no PT_LOAD header entries at all. /
1470	main_map->l_map_start = ~`0`;
1471	/ And it was opened directly. /
1472	++main_map->l_direct_opencount;
1473
1474	/ Scan the program header table for the dynamic section. /
1475	for (ph = phdr; ph < &phdr[phnum]; ++ph)
1476	switch (ph->p_type)
1477	{
1478	case PT_PHDR:
1479	/ Find out the load address. /
1480	main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
1481	break;
1482	case PT_DYNAMIC:
1483	/ This tells us where to find the dynamic section,*
1484	which tells us everything we need to do. /*
1485	main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
1486	break;
1487	case PT_INTERP:
1488	/ This "interpreter segment" was used by the program loader to*
1489	find the program interpreter, which is this program itself, the
1490	dynamic linker. We note what name finds us, so that a future
1491	dlopen call or DT_NEEDED entry, for something that wants to link
1492	against the dynamic linker as a shared library, will know that
1493	the shared object is already loaded. /*
1494	_dl_rtld_libname.name = ((const char *) main_map->l_addr
1495	+ ph->p_vaddr);
1496	/ _dl_rtld_libname.next = NULL; Already zero. /
1497	GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1498
1499	/ Ordinarilly, we would get additional names for the loader from*
1500	our DT_SONAME. This can't happen if we were actually linked as
1501	a static executable (detect this case when we have no DYNAMIC).
1502	If so, assume the filename component of the interpreter path to
1503	be our SONAME, and add it to our name list. /*
1504	if (GL(dl_rtld_map).l_ld == NULL)
1505	{
1506	const char *p = NULL;
1507	const char *cp = _dl_rtld_libname.name;
1508
1509	/ Find the filename part of the path. /
1510	while (*cp != `'\0'`)
1511	if (*cp++ == `'/'`)
1512	p = cp;
1513
1514	if (p != NULL)
1515	{
1516	_dl_rtld_libname2.name = p;
1517	/ _dl_rtld_libname2.next = NULL; Already zero. /
1518	_dl_rtld_libname.next = &_dl_rtld_libname2;
1519	}
1520	}
1521
1522	has_interp = true;
1523	break;
1524	case PT_LOAD:
1525	{
1526	ElfW(Addr) mapstart;
1527	ElfW(Addr) allocend;
1528
1529	/ Remember where the main program starts in memory. /
1530	mapstart = (main_map->l_addr
1531	+ (ph->p_vaddr & ~(GLRO(dl_pagesize) - `1`)));
1532	if (main_map->l_map_start > mapstart)
1533	main_map->l_map_start = mapstart;
1534
1535	/ Also where it ends. /
1536	allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
1537	if (main_map->l_map_end < allocend)
1538	main_map->l_map_end = allocend;
1539	if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
1540	main_map->l_text_end = allocend;
1541	}
1542	break;
1543
1544	case PT_TLS:
1545	if (ph->p_memsz > `0`)
1546	{
1547	/ Note that in the case the dynamic linker we duplicate work*
1548	here since we read the PT_TLS entry already in
1549	_dl_start_final. But the result is repeatable so do not
1550	check for this special but unimportant case. /*
1551	main_map->l_tls_blocksize = ph->p_memsz;
1552	main_map->l_tls_align = ph->p_align;
1553	if (ph->p_align == `0`)
1554	main_map->l_tls_firstbyte_offset = `0`;
1555	else
1556	main_map->l_tls_firstbyte_offset = (ph->p_vaddr
1557	& (ph->p_align - `1`));
1558	main_map->l_tls_initimage_size = ph->p_filesz;
1559	main_map->l_tls_initimage = (void *) ph->p_vaddr;
1560
1561	/ This image gets the ID one. /
1562	GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = `1`;
1563	}
1564	break;
1565
1566	case PT_GNU_STACK:
1567	GL(dl_stack_flags) = ph->p_flags;
1568	break;
1569
1570	case PT_GNU_RELRO:
1571	main_map->l_relro_addr = ph->p_vaddr;
1572	main_map->l_relro_size = ph->p_memsz;
1573	break;
1574	}
1575	/ Process program headers again, but scan them backwards so*
1576	that PT_NOTE can be skipped if PT_GNU_PROPERTY exits. /*
1577	for (ph = &phdr[phnum]; ph != phdr; --ph)
1578	switch (ph[-`1`].p_type)
1579	{
1580	case PT_NOTE:
1581	_dl_process_pt_note (main_map, -`1`, &ph[-`1`]);
1582	break;
1583	case PT_GNU_PROPERTY:
1584	_dl_process_pt_gnu_property (main_map, -`1`, &ph[-`1`]);
1585	break;
1586	}
1587
1588	/ Adjust the address of the TLS initialization image in case*
1589	the executable is actually an ET_DYN object. /*
1590	if (main_map->l_tls_initimage != NULL)
1591	main_map->l_tls_initimage
1592	= (char *) main_map->l_tls_initimage + main_map->l_addr;
1593	if (! main_map->l_map_end)
1594	main_map->l_map_end = ~`0`;
1595	if (! main_map->l_text_end)
1596	main_map->l_text_end = ~`0`;
1597	if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
1598	{
1599	/ We were invoked directly, so the program might not have a*
1600	PT_INTERP. /*
1601	_dl_rtld_libname.name = GL(dl_rtld_map).l_name;
1602	/ _dl_rtld_libname.next = NULL; Already zero. /
1603	GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
1604	}
1605	else
1606	assert (GL(dl_rtld_map).l_libname); / How else did we get here? /
1607
1608	/ If the current libname is different from the SONAME, add the*
1609	latter as well. /*
1610	if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
1611	&& strcmp (GL(dl_rtld_map).l_libname->name,
1612	(const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1613	+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != `0`)
1614	{
1615	static struct libname_list newname;
1616	newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
1617	+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
1618	newname.next = NULL;
1619	newname.dont_free = `1`;
1620
1621	assert (GL(dl_rtld_map).l_libname->next == NULL);
1622	GL(dl_rtld_map).l_libname->next = &newname;
1623	}
1624	/ The ld.so must be relocated since otherwise loading audit modules*
1625	will fail since they reuse the very same ld.so. /*
1626	assert (GL(dl_rtld_map).l_relocated);
1627
1628	if (! rtld_is_main)
1629	{
1630	/ Extract the contents of the dynamic section for easy access. /
1631	elf_get_dynamic_info (main_map, NULL);
1632
1633	/ If the main map is libc.so, update the base namespace to*
1634	refer to this map. If libc.so is loaded later, this happens
1635	in _dl_map_object_from_fd. /*
1636	if (main_map->l_info[DT_SONAME] != NULL
1637	&& (strcmp (((const char *) D_PTR (main_map, l_info[DT_STRTAB])
1638	+ main_map->l_info[DT_SONAME]->d_un.d_val), LIBC_SO)
1639	== `0`))
1640	GL(dl_ns)[LM_ID_BASE].libc_map = main_map;
1641
1642	/ Set up our cache of pointers into the hash table. /
1643	_dl_setup_hash (main_map);
1644	}
1645
1646	if (__glibc_unlikely (state.mode == rtld_mode_verify))
1647	{
1648	/ We were called just to verify that this is a dynamic*
1649	executable using us as the program interpreter. Exit with an
1650	error if we were not able to load the binary or no interpreter
1651	is specified (i.e., this is no dynamically linked binary. /*
1652	if (main_map->l_ld == NULL)
1653	_exit (`1`);
1654
1655	/ We allow here some platform specific code. /
1656	#ifdef DISTINGUISH_LIB_VERSIONS
1657	DISTINGUISH_LIB_VERSIONS;
1658	#endif
1659	_exit (has_interp ? `0` : `2`);
1660	}
1661
1662	struct link_map **first_preload = &GL(dl_rtld_map).l_next;
1663	/ Set up the data structures for the system-supplied DSO early,*
1664	so they can influence _dl_init_paths. /*
1665	setup_vdso (main_map, &first_preload);
1666
1667	/ With vDSO setup we can initialize the function pointers. /
1668	setup_vdso_pointers ();
1669
1670	#ifdef DL_SYSDEP_OSCHECK
1671	DL_SYSDEP_OSCHECK (_dl_fatal_printf);
1672	#endif
1673
1674	/ Initialize the data structures for the search paths for shared*
1675	objects. /*
1676	call_init_paths (&state);
1677
1678	/ Initialize _r_debug. /
1679	struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
1680	LM_ID_BASE);
1681	r->r_state = RT_CONSISTENT;
1682
1683	/ Put the link_map for ourselves on the chain so it can be found by*
1684	name. Note that at this point the global chain of link maps contains
1685	exactly one element, which is pointed to by dl_loaded. /*
1686	if (! GL(dl_rtld_map).l_name)
1687	/ If not invoked directly, the dynamic linker shared object file was*
1688	found by the PT_INTERP name. /*
1689	GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
1690	GL(dl_rtld_map).l_type = lt_library;
1691	main_map->l_next = &GL(dl_rtld_map);
1692	GL(dl_rtld_map).l_prev = main_map;
1693	++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
1694	++GL(dl_load_adds);
1695
1696	/ If LD_USE_LOAD_BIAS env variable has not been seen, default*
1697	to not using bias for non-prelinked PIEs and libraries
1698	and using it for executables or prelinked PIEs or libraries. /*
1699	if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -`2`)
1700	GLRO(dl_use_load_bias) = main_map->l_addr == `0` ? -`1` : `0`;
1701
1702	/ Set up the program header information for the dynamic linker*
1703	itself. It is needed in the dl_iterate_phdr callbacks. /*
1704	const ElfW(Ehdr) *rtld_ehdr;
1705
1706	/ Starting from binutils-2.23, the linker will define the magic symbol*
1707	__ehdr_start to point to our own ELF header if it is visible in a
1708	segment that also includes the phdrs. If that's not available, we use
1709	the old method that assumes the beginning of the file is part of the
1710	lowest-addressed PT_LOAD segment. /*
1711	#ifdef HAVE_EHDR_START
1712	extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
1713	rtld_ehdr = &__ehdr_start;
1714	#else
1715	rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
1716	#endif
1717	assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr);
1718	assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr)));
1719
1720	const ElfW(Phdr) rtld_phdr = (const* void *) rtld_ehdr + rtld_ehdr->e_phoff;
1721
1722	GL(dl_rtld_map).l_phdr = rtld_phdr;
1723	GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
1724
1725
1726	/ PT_GNU_RELRO is usually the last phdr. /
1727	size_t cnt = rtld_ehdr->e_phnum;
1728	while (cnt-- > `0`)
1729	if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
1730	{
1731	GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
1732	GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
1733	break;
1734	}
1735
1736	/ Add the dynamic linker to the TLS list if it also uses TLS. /
1737	if (GL(dl_rtld_map).l_tls_blocksize != `0`)
1738	/ Assign a module ID. Do this before loading any audit modules. /
1739	GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
1740
1741	audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_AUDIT);
1742	audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_DEPAUDIT);
1743
1744	/ At this point, all data has been obtained that is included in the*
1745	--help output. /*
1746	if (__glibc_unlikely (state.mode == rtld_mode_help))
1747	_dl_help (ld_so_name, &state);
1748
1749	/ If we have auditing DSOs to load, do it now. /
1750	bool need_security_init = true;
1751	if (state.audit_list.length > `0`)
1752	{
1753	size_t naudit = audit_list_count (&state.audit_list);
1754
1755	/ Since we start using the auditing DSOs right away we need to*
1756	initialize the data structures now. /*
1757	tcbp = init_tls (naudit);
1758
1759	/ Initialize security features. We need to do it this early*
1760	since otherwise the constructors of the audit libraries will
1761	use different values (especially the pointer guard) and will
1762	fail later on. /*
1763	security_init ();
1764	need_security_init = false;
1765
1766	load_audit_modules (main_map, &state.audit_list);
1767
1768	/ The count based on audit strings may overestimate the number*
1769	of audit modules that got loaded, but not underestimate. /*
1770	assert (GLRO(dl_naudit) <= naudit);
1771	}
1772
1773	/ Keep track of the currently loaded modules to count how many*
1774	non-audit modules which use TLS are loaded. /*
1775	size_t count_modids = _dl_count_modids ();
1776
1777	/ Set up debugging before the debugger is notified for the first time. /
1778	#ifdef ELF_MACHINE_DEBUG_SETUP
1779	/ Some machines (e.g. MIPS) don't use DT_DEBUG in this way. /
1780	ELF_MACHINE_DEBUG_SETUP (main_map, r);
1781	ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
1782	#else
1783	if (main_map->l_info[DT_DEBUG] != NULL)
1784	/ There is a DT_DEBUG entry in the dynamic section. Fill it in*
1785	with the run-time address of the r_debug structure /*
1786	main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1787
1788	/ Fill in the pointer in the dynamic linker's own dynamic section, in*
1789	case you run gdb on the dynamic linker directly. /*
1790	if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
1791	GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
1792	#endif
1793
1794	/ We start adding objects. /
1795	r->r_state = RT_ADD;
1796	_dl_debug_state ();
1797	LIBC_PROBE (init_start, `2`, LM_ID_BASE, r);
1798
1799	/ Auditing checkpoint: we are ready to signal that the initial map*
1800	is being constructed. /*
1801	if (__glibc_unlikely (GLRO(dl_naudit) > `0`))
1802	{
1803	struct audit_ifaces *afct = GLRO(dl_audit);
1804	for (unsigned int cnt = `0`; cnt < GLRO(dl_naudit); ++cnt)
1805	{
1806	if (afct->activity != NULL)
1807	afct->activity (&link_map_audit_state (main_map, cnt)->cookie,
1808	LA_ACT_ADD);
1809
1810	afct = afct->next;
1811	}
1812	}
1813
1814	/ We have two ways to specify objects to preload: via environment*
1815	variable and via the file /etc/ld.so.preload. The latter can also
1816	be used when security is enabled. /*
1817	assert (*first_preload == NULL);
1818	struct link_map **preloads = NULL;
1819	unsigned int npreloads = `0`;
1820
1821	if (__glibc_unlikely (state.preloadlist != NULL))
1822	{
1823	RTLD_TIMING_VAR (start);
1824	rtld_timer_start (&start);
1825	npreloads += handle_preload_list (state.preloadlist, main_map,
1826	"LD_PRELOAD");
1827	rtld_timer_accum (&load_time, start);
1828	}
1829
1830	if (__glibc_unlikely (state.preloadarg != NULL))
1831	{
1832	RTLD_TIMING_VAR (start);
1833	rtld_timer_start (&start);
1834	npreloads += handle_preload_list (state.preloadarg, main_map,
1835	"--preload");
1836	rtld_timer_accum (&load_time, start);
1837	}
1838
1839	/ There usually is no ld.so.preload file, it should only be used*
1840	for emergencies and testing. So the open call etc should usually
1841	fail. Using access() on a non-existing file is faster than using
1842	open(). So we do this first. If it succeeds we do almost twice
1843	the work but this does not matter, since it is not for production
1844	use. /*
1845	static const char preload_file[] = "/etc/ld.so.preload";
1846	if (__glibc_unlikely (__access (preload_file, R_OK) == `0`))
1847	{
1848	/ Read the contents of the file. /
1849	file = _dl_sysdep_read_whole_file (preload_file, &file_size,
1850	PROT_READ \| PROT_WRITE);
1851	if (__glibc_unlikely (file != MAP_FAILED))
1852	{
1853	/ Parse the file. It contains names of libraries to be loaded,*
1854	separated by white spaces or `:'. It may also contain
1855	comments introduced by `#'. /*
1856	char *problem;
1857	char *runp;
1858	size_t rest;
1859
1860	/ Eliminate comments. /
1861	runp = file;
1862	rest = file_size;
1863	while (rest > `0`)
1864	{
1865	char *comment = memchr (runp, `'#'`, rest);
1866	if (comment == NULL)
1867	break;
1868
1869	rest -= comment - runp;
1870	do
1871	*comment = `' '`;
1872	while (--rest > `0` && *++comment != `'\n'`);
1873	}
1874
1875	/ We have one problematic case: if we have a name at the end of*
1876	the file without a trailing terminating characters, we cannot
1877	place the \0. Handle the case separately. /*
1878	if (file[file_size - `1`] != `' '` && file[file_size - `1`] != `'\t'`
1879	&& file[file_size - `1`] != `'\n'` && file[file_size - `1`] != `':'`)
1880	{
1881	problem = &file[file_size];
1882	while (problem > file && problem[-`1`] != `' '`
1883	&& problem[-`1`] != `'\t'`
1884	&& problem[-`1`] != `'\n'` && problem[-`1`] != `':'`)
1885	--problem;
1886
1887	if (problem > file)
1888	problem[-`1`] = `'\0'`;
1889	}
1890	else
1891	{
1892	problem = NULL;
1893	file[file_size - `1`] = `'\0'`;
1894	}
1895
1896	RTLD_TIMING_VAR (start);
1897	rtld_timer_start (&start);
1898
1899	if (file != problem)
1900	{
1901	char *p;
1902	runp = file;
1903	while ((p = strsep (&runp, ": \t\n")) != NULL)
1904	if (p[`0`] != `'\0'`)
1905	npreloads += do_preload (p, main_map, preload_file);
1906	}
1907
1908	if (problem != NULL)
1909	{
1910	char *p = strndupa (problem, file_size - (problem - file));
1911
1912	npreloads += do_preload (p, main_map, preload_file);
1913	}
1914
1915	rtld_timer_accum (&load_time, start);
1916
1917	/ We don't need the file anymore. /
1918	__munmap (file, file_size);
1919	}
1920	}
1921
1922	if (__glibc_unlikely (*first_preload != NULL))
1923	{
1924	/ Set up PRELOADS with a vector of the preloaded libraries. /
1925	struct link_map l = first_preload;
1926	preloads = __alloca (npreloads * sizeof preloads[`0`]);
1927	i = `0`;
1928	do
1929	{
1930	preloads[i++] = l;
1931	l = l->l_next;
1932	} while (l);
1933	assert (i == npreloads);
1934	}
1935
1936	/ Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD*
1937	specified some libraries to load, these are inserted before the actual
1938	dependencies in the executable's searchlist for symbol resolution. /*
1939	{
1940	RTLD_TIMING_VAR (start);
1941	rtld_timer_start (&start);
1942	_dl_map_object_deps (main_map, preloads, npreloads,
1943	state.mode == rtld_mode_trace, `0`);
1944	rtld_timer_accum (&load_time, start);
1945	}
1946
1947	/ Mark all objects as being in the global scope. /
1948	for (i = main_map->l_searchlist.r_nlist; i > `0`; )
1949	main_map->l_searchlist.r_list[--i]->l_global = `1`;
1950
1951	/ Remove _dl_rtld_map from the chain. /
1952	GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
1953	if (GL(dl_rtld_map).l_next != NULL)
1954	GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
1955
1956	for (i = `1`; i < main_map->l_searchlist.r_nlist; ++i)
1957	if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
1958	break;
1959
1960	bool rtld_multiple_ref = false;
1961	if (__glibc_likely (i < main_map->l_searchlist.r_nlist))
1962	{
1963	/ Some DT_NEEDED entry referred to the interpreter object itself, so*
1964	put it back in the list of visible objects. We insert it into the
1965	chain in symbol search order because gdb uses the chain's order as
1966	its symbol search order. /*
1967	rtld_multiple_ref = true;
1968
1969	GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - `1`];
1970	if (__glibc_likely (state.mode == rtld_mode_normal))
1971	{
1972	GL(dl_rtld_map).l_next = (i + `1` < main_map->l_searchlist.r_nlist
1973	? main_map->l_searchlist.r_list[i + `1`]
1974	: NULL);
1975	#ifdef NEED_DL_SYSINFO_DSO
1976	if (GLRO(dl_sysinfo_map) != NULL
1977	&& GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
1978	&& GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
1979	GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
1980	#endif
1981	}
1982	else
1983	/ In trace mode there might be an invisible object (which we*
1984	could not find) after the previous one in the search list.
1985	In this case it doesn't matter much where we put the
1986	interpreter object, so we just initialize the list pointer so
1987	that the assertion below holds. /*
1988	GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
1989
1990	assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
1991	GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
1992	if (GL(dl_rtld_map).l_next != NULL)
1993	{
1994	assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
1995	GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
1996	}
1997	}
1998
1999	/ Now let us see whether all libraries are available in the*
2000	versions we need. /*
2001	{
2002	struct version_check_args args;
2003	args.doexit = state.mode == rtld_mode_normal;
2004	args.dotrace = state.mode == rtld_mode_trace;
2005	_dl_receive_error (print_missing_version, version_check_doit, &args);
2006	}
2007
2008	/ We do not initialize any of the TLS functionality unless any of the*
2009	initial modules uses TLS. This makes dynamic loading of modules with
2010	TLS impossible, but to support it requires either eagerly doing setup
2011	now or lazily doing it later. Doing it now makes us incompatible with
2012	an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
2013	used. Trying to do it lazily is too hairy to try when there could be
2014	multiple threads (from a non-TLS-using libpthread). /*
2015	bool was_tls_init_tp_called = tls_init_tp_called;
2016	if (tcbp == NULL)
2017	tcbp = init_tls (`0`);
2018
2019	if (__glibc_likely (need_security_init))
2020	/ Initialize security features. But only if we have not done it*
2021	earlier. /*
2022	security_init ();
2023
2024	if (__glibc_unlikely (state.mode != rtld_mode_normal))
2025	{
2026	/ We were run just to list the shared libraries. It is*
2027	important that we do this before real relocation, because the
2028	functions we call below for output may no longer work properly
2029	after relocation. /*
2030	struct link_map *l;
2031
2032	if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2033	{
2034	struct r_scope_elem *scope = &main_map->l_searchlist;
2035
2036	for (i = `0`; i < scope->r_nlist; i++)
2037	{
2038	l = scope->r_list [i];
2039	if (l->l_faked)
2040	{
2041	_dl_printf ("\t%s => not found\n", l->l_libname->name);
2042	continue;
2043	}
2044	if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
2045	GLRO(dl_trace_prelink_map) = l;
2046	_dl_printf ("\t%s => %s (0x%0Zx, 0x%0Zx)",
2047	DSO_FILENAME (l->l_libname->name),
2048	DSO_FILENAME (l->l_name),
2049	(int) sizeof l->l_map_start * `2`,
2050	(size_t) l->l_map_start,
2051	(int) sizeof l->l_addr * `2`,
2052	(size_t) l->l_addr);
2053
2054	if (l->l_tls_modid)
2055	_dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
2056	(int) sizeof l->l_tls_offset * `2`,
2057	(size_t) l->l_tls_offset);
2058	else
2059	_dl_printf ("\n");
2060	}
2061	}
2062	else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
2063	{
2064	/ Look through the dependencies of the main executable*
2065	and determine which of them is not actually
2066	required. /*
2067	struct link_map *l = main_map;
2068
2069	/ Relocate the main executable. /
2070	struct relocate_args args = { .l = l,
2071	.reloc_mode = ((GLRO(dl_lazy)
2072	? RTLD_LAZY : `0`)
2073	\| __RTLD_NOIFUNC) };
2074	_dl_receive_error (print_unresolved, relocate_doit, &args);
2075
2076	/ This loop depends on the dependencies of the executable to*
2077	correspond in number and order to the DT_NEEDED entries. /*
2078	ElfW(Dyn) *dyn = main_map->l_ld;
2079	bool first = true;
2080	while (dyn->d_tag != DT_NULL)
2081	{
2082	if (dyn->d_tag == DT_NEEDED)
2083	{
2084	l = l->l_next;
2085	#ifdef NEED_DL_SYSINFO_DSO
2086	/ Skip the VDSO since it's not part of the list*
2087	of objects we brought in via DT_NEEDED entries. /*
2088	if (l == GLRO(dl_sysinfo_map))
2089	l = l->l_next;
2090	#endif
2091	if (!l->l_used)
2092	{
2093	if (first)
2094	{
2095	_dl_printf ("Unused direct dependencies:\n");
2096	first = false;
2097	}
2098
2099	_dl_printf ("\t%s\n", l->l_name);
2100	}
2101	}
2102
2103	++dyn;
2104	}
2105
2106	_exit (first != true);
2107	}
2108	else if (! main_map->l_info[DT_NEEDED])
2109	_dl_printf ("\tstatically linked\n");
2110	else
2111	{
2112	for (l = main_map->l_next; l; l = l->l_next)
2113	if (l->l_faked)
2114	/ The library was not found. /
2115	_dl_printf ("\t%s => not found\n", l->l_libname->name);
2116	else if (strcmp (l->l_libname->name, l->l_name) == `0`)
2117	_dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
2118	(int) sizeof l->l_map_start * `2`,
2119	(size_t) l->l_map_start);
2120	else
2121	_dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
2122	l->l_name, (int) sizeof l->l_map_start * `2`,
2123	(size_t) l->l_map_start);
2124	}
2125
2126	if (__glibc_unlikely (state.mode != rtld_mode_trace))
2127	for (i = `1`; i < (unsigned int) _dl_argc; ++i)
2128	{
2129	const ElfW(Sym) *ref = NULL;
2130	ElfW(Addr) loadbase;
2131	lookup_t result;
2132
2133	result = _dl_lookup_symbol_x (_dl_argv[i], main_map,
2134	&ref, main_map->l_scope,
2135	NULL, ELF_RTYPE_CLASS_PLT,
2136	DL_LOOKUP_ADD_DEPENDENCY, NULL);
2137
2138	loadbase = LOOKUP_VALUE_ADDRESS (result, false);
2139
2140	_dl_printf ("%s found at 0x%0Zd in object at 0x%0Zd\n",
2141	_dl_argv[i],
2142	(int) sizeof ref->st_value * `2`,
2143	(size_t) ref->st_value,
2144	(int) sizeof loadbase * `2`, (size_t) loadbase);
2145	}
2146	else
2147	{
2148	/ If LD_WARN is set, warn about undefined symbols. /
2149	if (GLRO(dl_lazy) >= `0` && GLRO(dl_verbose))
2150	{
2151	/ We have to do symbol dependency testing. /
2152	struct relocate_args args;
2153	unsigned int i;
2154
2155	args.reloc_mode = ((GLRO(dl_lazy) ? RTLD_LAZY : `0`)
2156	\| __RTLD_NOIFUNC);
2157
2158	i = main_map->l_searchlist.r_nlist;
2159	while (i-- > `0`)
2160	{
2161	struct link_map *l = main_map->l_initfini[i];
2162	if (l != &GL(dl_rtld_map) && ! l->l_faked)
2163	{
2164	args.l = l;
2165	_dl_receive_error (print_unresolved, relocate_doit,
2166	&args);
2167	}
2168	}
2169
2170	if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
2171	&& rtld_multiple_ref)
2172	{
2173	/ Mark the link map as not yet relocated again. /
2174	GL(dl_rtld_map).l_relocated = `0`;
2175	_dl_relocate_object (&GL(dl_rtld_map),
2176	main_map->l_scope, __RTLD_NOIFUNC, `0`);
2177	}
2178	}
2179	#define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
2180	if (state.version_info)
2181	{
2182	/ Print more information. This means here, print information*
2183	about the versions needed. /*
2184	int first = `1`;
2185	struct link_map *map;
2186
2187	for (map = main_map; map != NULL; map = map->l_next)
2188	{
2189	const char *strtab;
2190	ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
2191	ElfW(Verneed) *ent;
2192
2193	if (dyn == NULL)
2194	continue;
2195
2196	strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
2197	ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
2198
2199	if (first)
2200	{
2201	_dl_printf ("\n\tVersion information:\n");
2202	first = `0`;
2203	}
2204
2205	_dl_printf ("\t%s:\n", DSO_FILENAME (map->l_name));
2206
2207	while (`1`)
2208	{
2209	ElfW(Vernaux) *aux;
2210	struct link_map *needed;
2211
2212	needed = find_needed (strtab + ent->vn_file);
2213	aux = (ElfW(Vernaux) ) ((char* *) ent + ent->vn_aux);
2214
2215	while (`1`)
2216	{
2217	const char *fname = NULL;
2218
2219	if (needed != NULL
2220	&& match_version (strtab + aux->vna_name,
2221	needed))
2222	fname = needed->l_name;
2223
2224	_dl_printf ("\t\t%s (%s) %s=> %s\n",
2225	strtab + ent->vn_file,
2226	strtab + aux->vna_name,
2227	aux->vna_flags & VER_FLG_WEAK
2228	? "[WEAK] " : "",
2229	fname ?: "not found");
2230
2231	if (aux->vna_next == `0`)
2232	/ No more symbols. /
2233	break;
2234
2235	/ Next symbol. /
2236	aux = (ElfW(Vernaux) ) ((char* *) aux
2237	+ aux->vna_next);
2238	}
2239
2240	if (ent->vn_next == `0`)
2241	/ No more dependencies. /
2242	break;
2243
2244	/ Next dependency. /
2245	ent = (ElfW(Verneed) ) ((char* *) ent + ent->vn_next);
2246	}
2247	}
2248	}
2249	}
2250
2251	_exit (`0`);
2252	}
2253
2254	if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
2255	&& ! __builtin_expect (GLRO(dl_profile) != NULL, `0`)
2256	&& ! __builtin_expect (GLRO(dl_dynamic_weak), `0`))
2257	{
2258	ElfW(Lib) liblist, liblistend;
2259	struct link_map r_list, r_listend, *l;
2260	const char strtab = (const* void *) D_PTR (main_map, l_info[DT_STRTAB]);
2261
2262	assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
2263	liblist = (ElfW(Lib) *)
2264	main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
2265	liblistend = (ElfW(Lib) *)
2266	((char *) liblist
2267	+ main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
2268	r_list = main_map->l_searchlist.r_list;
2269	r_listend = r_list + main_map->l_searchlist.r_nlist;
2270
2271	for (; r_list < r_listend && liblist < liblistend; r_list++)
2272	{
2273	l = *r_list;
2274
2275	if (l == main_map)
2276	continue;
2277
2278	/ If the library is not mapped where it should, fail. /
2279	if (l->l_addr)
2280	break;
2281
2282	/ Next, check if checksum matches. /
2283	if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
2284	\|\| l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
2285	!= liblist->l_checksum)
2286	break;
2287
2288	if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
2289	\|\| l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
2290	!= liblist->l_time_stamp)
2291	break;
2292
2293	if (! _dl_name_match_p (strtab + liblist->l_name, l))
2294	break;
2295
2296	++liblist;
2297	}
2298
2299
2300	if (r_list == r_listend && liblist == liblistend)
2301	prelinked = true;
2302
2303	if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
2304	_dl_debug_printf ("\nprelink checking: %s\n",
2305	prelinked ? "ok" : "failed");
2306	}
2307
2308
2309	/ Now set up the variable which helps the assembler startup code. /
2310	GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
2311
2312	/ Save the information about the original global scope list since*
2313	we need it in the memory handling later. /*
2314	GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
2315
2316	/ Remember the last search directory added at startup, now that*
2317	malloc will no longer be the one from dl-minimal.c. As a side
2318	effect, this marks ld.so as initialized, so that the rtld_active
2319	function returns true from now on. /*
2320	GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
2321
2322	/ Print scope information. /
2323	if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
2324	{
2325	_dl_debug_printf ("\nInitial object scopes\n");
2326
2327	for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2328	_dl_show_scope (l, `0`);
2329	}
2330
2331	_rtld_main_check (main_map, _dl_argv[`0`]);
2332
2333	if (prelinked)
2334	{
2335	if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
2336	{
2337	ElfW(Rela) conflict, conflictend;
2338
2339	RTLD_TIMING_VAR (start);
2340	rtld_timer_start (&start);
2341
2342	assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
2343	conflict = (ElfW(Rela) *)
2344	main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
2345	conflictend = (ElfW(Rela) *)
2346	((char *) conflict
2347	+ main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
2348	_dl_resolve_conflicts (main_map, conflict, conflictend);
2349
2350	rtld_timer_stop (&relocate_time, start);
2351	}
2352
2353	/ The library defining malloc has already been relocated due to*
2354	prelinking. Resolve the malloc symbols for the dynamic
2355	loader. /*
2356	__rtld_malloc_init_real (main_map);
2357
2358	/ Mark all the objects so we know they have been already relocated. /
2359	for (struct link_map *l = main_map; l != NULL; l = l->l_next)
2360	{
2361	l->l_relocated = `1`;
2362	if (l->l_relro_size)
2363	_dl_protect_relro (l);
2364
2365	/ Add object to slot information data if necessasy. /
2366	if (l->l_tls_blocksize != `0` && tls_init_tp_called)
2367	_dl_add_to_slotinfo (l, true);
2368	}
2369	}
2370	else
2371	{
2372	/ Now we have all the objects loaded. Relocate them all except for*
2373	the dynamic linker itself. We do this in reverse order so that copy
2374	relocs of earlier objects overwrite the data written by later
2375	objects. We do not re-relocate the dynamic linker itself in this
2376	loop because that could result in the GOT entries for functions we
2377	call being changed, and that would break us. It is safe to relocate
2378	the dynamic linker out of order because it has no copy relocs (we
2379	know that because it is self-contained). /*
2380
2381	int consider_profiling = GLRO(dl_profile) != NULL;
2382
2383	/ If we are profiling we also must do lazy reloaction. /
2384	GLRO(dl_lazy) \|= consider_profiling;
2385
2386	RTLD_TIMING_VAR (start);
2387	rtld_timer_start (&start);
2388	unsigned i = main_map->l_searchlist.r_nlist;
2389	while (i-- > `0`)
2390	{
2391	struct link_map *l = main_map->l_initfini[i];
2392
2393	/ While we are at it, help the memory handling a bit. We have to*
2394	mark some data structures as allocated with the fake malloc()
2395	implementation in ld.so. /*
2396	struct libname_list *lnp = l->l_libname->next;
2397
2398	while (__builtin_expect (lnp != NULL, `0`))
2399	{
2400	lnp->dont_free = `1`;
2401	lnp = lnp->next;
2402	}
2403	/ Also allocated with the fake malloc(). /
2404	l->l_free_initfini = `0`;
2405
2406	if (l != &GL(dl_rtld_map))
2407	_dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : `0`,
2408	consider_profiling);
2409
2410	/ Add object to slot information data if necessasy. /
2411	if (l->l_tls_blocksize != `0` && tls_init_tp_called)
2412	_dl_add_to_slotinfo (l, true);
2413	}
2414	rtld_timer_stop (&relocate_time, start);
2415
2416	/ Now enable profiling if needed. Like the previous call,*
2417	this has to go here because the calls it makes should use the
2418	rtld versions of the functions (particularly calloc()), but it
2419	needs to have _dl_profile_map set up by the relocator. /*
2420	if (__glibc_unlikely (GL(dl_profile_map) != NULL))
2421	/ We must prepare the profiling. /
2422	_dl_start_profile ();
2423	}
2424
2425	if ((!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > `0`)
2426	\|\| count_modids != _dl_count_modids ())
2427	++GL(dl_tls_generation);
2428
2429	/ Now that we have completed relocation, the initializer data*
2430	for the TLS blocks has its final values and we can copy them
2431	into the main thread's TLS area, which we allocated above.
2432	Note: thread-local variables must only be accessed after completing
2433	the next step. /*
2434	_dl_allocate_tls_init (tcbp);
2435
2436	/ And finally install it for the main thread. /
2437	if (! tls_init_tp_called)
2438	{
2439	const char *lossage = TLS_INIT_TP (tcbp);
2440	if (__glibc_unlikely (lossage != NULL))
2441	_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
2442	lossage);
2443	#if THREAD_GSCOPE_IN_TCB
2444	list_add (&THREAD_SELF->list, &GL (dl_stack_user));
2445	#endif
2446	}
2447
2448	/ Make sure no new search directories have been added. /
2449	assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
2450
2451	if (! prelinked && rtld_multiple_ref)
2452	{
2453	/ There was an explicit ref to the dynamic linker as a shared lib.*
2454	Re-relocate ourselves with user-controlled symbol definitions.
2455
2456	We must do this after TLS initialization in case after this
2457	re-relocation, we might call a user-supplied function
2458	(e.g. calloc from _dl_relocate_object) that uses TLS data. /*
2459
2460	/ The malloc implementation has been relocated, so resolving*
2461	its symbols (and potentially calling IFUNC resolvers) is safe
2462	at this point. /*
2463	__rtld_malloc_init_real (main_map);
2464
2465	RTLD_TIMING_VAR (start);
2466	rtld_timer_start (&start);
2467
2468	/ Mark the link map as not yet relocated again. /
2469	GL(dl_rtld_map).l_relocated = `0`;
2470	_dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, `0`, `0`);
2471
2472	rtld_timer_accum (&relocate_time, start);
2473	}
2474
2475	/ Relocation is complete. Perform early libc initialization. This*
2476	is the initial libc, even if audit modules have been loaded with
2477	other libcs. /*
2478	_dl_call_libc_early_init (GL(dl_ns)[LM_ID_BASE].libc_map, true);
2479
2480	/ Do any necessary cleanups for the startup OS interface code.*
2481	We do these now so that no calls are made after rtld re-relocation
2482	which might be resolved to different functions than we expect.
2483	We cannot do this before relocating the other objects because
2484	_dl_relocate_object might need to call `mprotect' for DT_TEXTREL. /*
2485	_dl_sysdep_start_cleanup ();
2486
2487	#ifdef SHARED
2488	/ Auditing checkpoint: we have added all objects. /
2489	if (__glibc_unlikely (GLRO(dl_naudit) > `0`))
2490	{
2491	struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
2492	/ Do not call the functions for any auditing object. /
2493	if (head->l_auditing == `0`)
2494	{
2495	struct audit_ifaces *afct = GLRO(dl_audit);
2496	for (unsigned int cnt = `0`; cnt < GLRO(dl_naudit); ++cnt)
2497	{
2498	if (afct->activity != NULL)
2499	afct->activity (&link_map_audit_state (head, cnt)->cookie,
2500	LA_ACT_CONSISTENT);
2501
2502	afct = afct->next;
2503	}
2504	}
2505	}
2506	#endif
2507
2508	/ Notify the debugger all new objects are now ready to go. We must re-get*
2509	the address since by now the variable might be in another object. /*
2510	r = _dl_debug_initialize (`0`, LM_ID_BASE);
2511	r->r_state = RT_CONSISTENT;
2512	_dl_debug_state ();
2513	LIBC_PROBE (init_complete, `2`, LM_ID_BASE, r);
2514
2515	#if defined USE_LDCONFIG && !defined MAP_COPY
2516	/ We must munmap() the cache file. /
2517	_dl_unload_cache ();
2518	#endif
2519
2520	/ Once we return, _dl_sysdep_start will invoke*
2521	the DT_INIT functions and then USER_ENTRY. /
2522	}
2523
2524	/ This is a little helper function for resolving symbols while*
2525	tracing the binary. /*
2526	static void
2527	print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
2528	const char *errstring)
2529	{
2530	if (objname[`0`] == `'\0'`)
2531	objname = RTLD_PROGNAME;
2532	_dl_error_printf ("%s (%s)\n", errstring, objname);
2533	}
2534
2535	/ This is a little helper function for resolving symbols while*
2536	tracing the binary. /*
2537	static void
2538	print_missing_version (int errcode __attribute__ ((unused)),
2539	const char objname, const* char *errstring)
2540	{
2541	_dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME,
2542	objname, errstring);
2543	}
2544
2545	/ Process the string given as the parameter which explains which debugging*
2546	options are enabled. /*
2547	static void
2548	process_dl_debug (struct dl_main_state state, const* char *dl_debug)
2549	{
2550	/ When adding new entries make sure that the maximal length of a name*
2551	is correctly handled in the LD_DEBUG_HELP code below. /*
2552	static const struct
2553	{
2554	unsigned char len;
2555	const char name[`10`];
2556	const char helptext[`41`];
2557	unsigned short int mask;
2558	} debopts[] =
2559	{
2560	#define LEN_AND_STR(str) sizeof (str) - 1, str
2561	{ LEN_AND_STR ("libs"), "display library search paths",
2562	DL_DEBUG_LIBS \| DL_DEBUG_IMPCALLS },
2563	{ LEN_AND_STR ("reloc"), "display relocation processing",
2564	DL_DEBUG_RELOC \| DL_DEBUG_IMPCALLS },
2565	{ LEN_AND_STR ("files"), "display progress for input file",
2566	DL_DEBUG_FILES \| DL_DEBUG_IMPCALLS },
2567	{ LEN_AND_STR ("symbols"), "display symbol table processing",
2568	DL_DEBUG_SYMBOLS \| DL_DEBUG_IMPCALLS },
2569	{ LEN_AND_STR ("bindings"), "display information about symbol binding",
2570	DL_DEBUG_BINDINGS \| DL_DEBUG_IMPCALLS },
2571	{ LEN_AND_STR ("versions"), "display version dependencies",
2572	DL_DEBUG_VERSIONS \| DL_DEBUG_IMPCALLS },
2573	{ LEN_AND_STR ("scopes"), "display scope information",
2574	DL_DEBUG_SCOPES },
2575	{ LEN_AND_STR ("all"), "all previous options combined",
2576	DL_DEBUG_LIBS \| DL_DEBUG_RELOC \| DL_DEBUG_FILES \| DL_DEBUG_SYMBOLS
2577	\| DL_DEBUG_BINDINGS \| DL_DEBUG_VERSIONS \| DL_DEBUG_IMPCALLS
2578	\| DL_DEBUG_SCOPES },
2579	{ LEN_AND_STR ("statistics"), "display relocation statistics",
2580	DL_DEBUG_STATISTICS },
2581	{ LEN_AND_STR ("unused"), "determined unused DSOs",
2582	DL_DEBUG_UNUSED },
2583	{ LEN_AND_STR ("help"), "display this help message and exit",
2584	DL_DEBUG_HELP },
2585	};
2586	#define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
2587
2588	/ Skip separating white spaces and commas. /
2589	while (*dl_debug != `'\0'`)
2590	{
2591	if (dl_debug != `' '` && dl_debug != `','` && *dl_debug != `':'`)
2592	{
2593	size_t cnt;
2594	size_t len = `1`;
2595
2596	while (dl_debug[len] != `'\0'` && dl_debug[len] != `' '`
2597	&& dl_debug[len] != `','` && dl_debug[len] != `':'`)
2598	++len;
2599
2600	for (cnt = `0`; cnt < ndebopts; ++cnt)
2601	if (debopts[cnt].len == len
2602	&& memcmp (dl_debug, debopts[cnt].name, len) == `0`)
2603	{
2604	GLRO(dl_debug_mask) \|= debopts[cnt].mask;
2605	state->any_debug = true;
2606	break;
2607	}
2608
2609	if (cnt == ndebopts)
2610	{
2611	/ Display a warning and skip everything until next*
2612	separator. /*
2613	char *copy = strndupa (dl_debug, len);
2614	_dl_error_printf ("\
2615	warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
2616	}
2617
2618	dl_debug += len;
2619	continue;
2620	}
2621
2622	++dl_debug;
2623	}
2624
2625	if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
2626	{
2627	/ In order to get an accurate picture of whether a particular*
2628	DT_NEEDED entry is actually used we have to process both
2629	the PLT and non-PLT relocation entries. /*
2630	GLRO(dl_lazy) = `0`;
2631	}
2632
2633	if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
2634	{
2635	size_t cnt;
2636
2637	_dl_printf ("\
2638	Valid options for the LD_DEBUG environment variable are:\n\n");
2639
2640	for (cnt = `0`; cnt < ndebopts; ++cnt)
2641	_dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
2642	" " + debopts[cnt].len - `3`,
2643	debopts[cnt].helptext);
2644
2645	_dl_printf ("\n\
2646	To direct the debugging output into a file instead of standard output\n\
2647	a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
2648	_exit (`0`);
2649	}
2650	}
2651
2652	/ Process all environments variables the dynamic linker must recognize.*
2653	Since all of them start with `LD_' we are a bit smarter while finding
2654	all the entries. /*
2655	extern char **_environ attribute_hidden;
2656
2657
2658	static void
2659	process_envvars (struct dl_main_state *state)
2660	{
2661	char **runp = _environ;
2662	char *envline;
2663	char *debug_output = NULL;
2664
2665	/ This is the default place for profiling data file. /
2666	GLRO(dl_profile_output)
2667	= &"/var/tmp\0/var/profile"[__libc_enable_secure ? `9` : `0`];
2668
2669	while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
2670	{
2671	size_t len = `0`;
2672
2673	while (envline[len] != `'\0'` && envline[len] != `'='`)
2674	++len;
2675
2676	if (envline[len] != `'='`)
2677	/ This is a "LD_" variable at the end of the string without*
2678	a '=' character. Ignore it since otherwise we will access
2679	invalid memory below. /*
2680	continue;
2681
2682	switch (len)
2683	{
2684	case `4`:
2685	/ Warning level, verbose or not. /
2686	if (memcmp (envline, "WARN", `4`) == `0`)
2687	GLRO(dl_verbose) = envline[`5`] != `'\0'`;
2688	break;
2689
2690	case `5`:
2691	/ Debugging of the dynamic linker? /
2692	if (memcmp (envline, "DEBUG", `5`) == `0`)
2693	{
2694	process_dl_debug (state, &envline[`6`]);
2695	break;
2696	}
2697	if (memcmp (envline, "AUDIT", `5`) == `0`)
2698	audit_list_add_string (&state->audit_list, &envline[`6`]);
2699	break;
2700
2701	case `7`:
2702	/ Print information about versions. /
2703	if (memcmp (envline, "VERBOSE", `7`) == `0`)
2704	{
2705	state->version_info = envline[`8`] != `'\0'`;
2706	break;
2707	}
2708
2709	/ List of objects to be preloaded. /
2710	if (memcmp (envline, "PRELOAD", `7`) == `0`)
2711	{
2712	state->preloadlist = &envline[`8`];
2713	break;
2714	}
2715
2716	/ Which shared object shall be profiled. /
2717	if (memcmp (envline, "PROFILE", `7`) == `0` && envline[`8`] != `'\0'`)
2718	GLRO(dl_profile) = &envline[`8`];
2719	break;
2720
2721	case `8`:
2722	/ Do we bind early? /
2723	if (memcmp (envline, "BIND_NOW", `8`) == `0`)
2724	{
2725	GLRO(dl_lazy) = envline[`9`] == `'\0'`;
2726	break;
2727	}
2728	if (memcmp (envline, "BIND_NOT", `8`) == `0`)
2729	GLRO(dl_bind_not) = envline[`9`] != `'\0'`;
2730	break;
2731
2732	case `9`:
2733	/ Test whether we want to see the content of the auxiliary*
2734	array passed up from the kernel. /*
2735	if (!__libc_enable_secure
2736	&& memcmp (envline, "SHOW_AUXV", `9`) == `0`)
2737	_dl_show_auxv ();
2738	break;
2739
2740	#if !HAVE_TUNABLES
2741	case `10`:
2742	/ Mask for the important hardware capabilities. /
2743	if (!__libc_enable_secure
2744	&& memcmp (envline, "HWCAP_MASK", `10`) == `0`)
2745	GLRO(dl_hwcap_mask) = _dl_strtoul (&envline[`11`], NULL);
2746	break;
2747	#endif
2748
2749	case `11`:
2750	/ Path where the binary is found. /
2751	if (!__libc_enable_secure
2752	&& memcmp (envline, "ORIGIN_PATH", `11`) == `0`)
2753	GLRO(dl_origin_path) = &envline[`12`];
2754	break;
2755
2756	case `12`:
2757	/ The library search path. /
2758	if (!__libc_enable_secure
2759	&& memcmp (envline, "LIBRARY_PATH", `12`) == `0`)
2760	{
2761	state->library_path = &envline[`13`];
2762	state->library_path_source = "LD_LIBRARY_PATH";
2763	break;
2764	}
2765
2766	/ Where to place the profiling data file. /
2767	if (memcmp (envline, "DEBUG_OUTPUT", `12`) == `0`)
2768	{
2769	debug_output = &envline[`13`];
2770	break;
2771	}
2772
2773	if (!__libc_enable_secure
2774	&& memcmp (envline, "DYNAMIC_WEAK", `12`) == `0`)
2775	GLRO(dl_dynamic_weak) = `1`;
2776	break;
2777
2778	case `13`:
2779	/ We might have some extra environment variable with length 13*
2780	to handle. /*
2781	#ifdef EXTRA_LD_ENVVARS_13
2782	EXTRA_LD_ENVVARS_13
2783	#endif
2784	if (!__libc_enable_secure
2785	&& memcmp (envline, "USE_LOAD_BIAS", `13`) == `0`)
2786	{
2787	GLRO(dl_use_load_bias) = envline[`14`] == `'1'` ? -`1` : `0`;
2788	break;
2789	}
2790	break;
2791
2792	case `14`:
2793	/ Where to place the profiling data file. /
2794	if (!__libc_enable_secure
2795	&& memcmp (envline, "PROFILE_OUTPUT", `14`) == `0`
2796	&& envline[`15`] != `'\0'`)
2797	GLRO(dl_profile_output) = &envline[`15`];
2798	break;
2799
2800	case `16`:
2801	/ The mode of the dynamic linker can be set. /
2802	if (memcmp (envline, "TRACE_PRELINKING", `16`) == `0`)
2803	{
2804	state->mode = rtld_mode_trace;
2805	GLRO(dl_verbose) = `1`;
2806	GLRO(dl_debug_mask) \|= DL_DEBUG_PRELINK;
2807	GLRO(dl_trace_prelink) = &envline[`17`];
2808	}
2809	break;
2810
2811	case `20`:
2812	/ The mode of the dynamic linker can be set. /
2813	if (memcmp (envline, "TRACE_LOADED_OBJECTS", `20`) == `0`)
2814	state->mode = rtld_mode_trace;
2815	break;
2816
2817	/ We might have some extra environment variable to handle. This*
2818	is tricky due to the pre-processing of the length of the name
2819	in the switch statement here. The code here assumes that added
2820	environment variables have a different length. /*
2821	#ifdef EXTRA_LD_ENVVARS
2822	EXTRA_LD_ENVVARS
2823	#endif
2824	}
2825	}
2826
2827	/ Extra security for SUID binaries. Remove all dangerous environment*
2828	variables. /*
2829	if (__builtin_expect (__libc_enable_secure, `0`))
2830	{
2831	static const char unsecure_envvars[] =
2832	#ifdef EXTRA_UNSECURE_ENVVARS
2833	EXTRA_UNSECURE_ENVVARS
2834	#endif
2835	UNSECURE_ENVVARS;
2836	const char *nextp;
2837
2838	nextp = unsecure_envvars;
2839	do
2840	{
2841	unsetenv (nextp);
2842	/ We could use rawmemchr but this need not be fast. /
2843	nextp = (char *) (strchr) (nextp, `'\0'`) + `1`;
2844	}
2845	while (*nextp != `'\0'`);
2846
2847	if (__access ("/etc/suid-debug", F_OK) != `0`)
2848	{
2849	#if !HAVE_TUNABLES
2850	unsetenv ("MALLOC_CHECK_");
2851	#endif
2852	GLRO(dl_debug_mask) = `0`;
2853	}
2854
2855	if (state->mode != rtld_mode_normal)
2856	_exit (`5`);
2857	}
2858	/ If we have to run the dynamic linker in debugging mode and the*
2859	LD_DEBUG_OUTPUT environment variable is given, we write the debug
2860	messages to this file. /*
2861	else if (state->any_debug && debug_output != NULL)
2862	{
2863	const int flags = O_WRONLY \| O_APPEND \| O_CREAT \| O_NOFOLLOW;
2864	size_t name_len = strlen (debug_output);
2865	char buf[name_len + `12`];
2866	char *startp;
2867
2868	buf[name_len + `11`] = `'\0'`;
2869	startp = _itoa (__getpid (), &buf[name_len + `11`], `10`, `0`);
2870	*--startp = `'.'`;
2871	startp = memcpy (startp - name_len, debug_output, name_len);
2872
2873	GLRO(dl_debug_fd) = __open64_nocancel (startp, flags, DEFFILEMODE);
2874	if (GLRO(dl_debug_fd) == -`1`)
2875	/ We use standard output if opening the file failed. /
2876	GLRO(dl_debug_fd) = STDOUT_FILENO;
2877	}
2878	}
2879
2880	#if HP_TIMING_INLINE
2881	static void
2882	print_statistics_item (const char *title, hp_timing_t time,
2883	hp_timing_t total)
2884	{
2885	char cycles[HP_TIMING_PRINT_SIZE];
2886	HP_TIMING_PRINT (cycles, sizeof (cycles), time);
2887
2888	char relative[`3` * sizeof (hp_timing_t) + `2`];
2889	char cp = _itoa ((`1000ULL` time) / total, relative + sizeof (relative),
2890	`10`, `0`);
2891	/ Sets the decimal point. /
2892	char *wp = relative;
2893	switch (relative + sizeof (relative) - cp)
2894	{
2895	case `3`:
2896	wp++ = cp++;
2897	/ Fall through. /
2898	case `2`:
2899	wp++ = cp++;
2900	/ Fall through. /
2901	case `1`:
2902	*wp++ = `'.'`;
2903	wp++ = cp++;
2904	}
2905	*wp = `'\0'`;
2906	_dl_debug_printf ("%s: %s cycles (%s%%)\n", title, cycles, relative);
2907	}
2908	#endif
2909
2910	/ Print the various times we collected. /
2911	static void
2912	__attribute ((noinline))
2913	print_statistics (const hp_timing_t *rtld_total_timep)
2914	{
2915	#if HP_TIMING_INLINE
2916	{
2917	char cycles[HP_TIMING_PRINT_SIZE];
2918	HP_TIMING_PRINT (cycles, sizeof (cycles), *rtld_total_timep);
2919	_dl_debug_printf ("\nruntime linker statistics:\n"
2920	" total startup time in dynamic loader: %s cycles\n",
2921	cycles);
2922	print_statistics_item (" time needed for relocation",
2923	relocate_time, *rtld_total_timep);
2924	}
2925	#endif
2926
2927	unsigned long int num_relative_relocations = `0`;
2928	for (Lmid_t ns = `0`; ns < GL(dl_nns); ++ns)
2929	{
2930	if (GL(dl_ns)[ns]._ns_loaded == NULL)
2931	continue;
2932
2933	struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
2934
2935	for (unsigned int i = `0`; i < scope->r_nlist; i++)
2936	{
2937	struct link_map *l = scope->r_list [i];
2938
2939	if (l->l_addr != `0` && l->l_info[VERSYMIDX (DT_RELCOUNT)])
2940	num_relative_relocations
2941	+= l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
2942	#ifndef ELF_MACHINE_REL_RELATIVE
2943	/ Relative relocations are processed on these architectures if*
2944	library is loaded to different address than p_vaddr or
2945	if not prelinked. /*
2946	if ((l->l_addr != `0` \|\| !l->l_info[VALIDX(DT_GNU_PRELINKED)])
2947	&& l->l_info[VERSYMIDX (DT_RELACOUNT)])
2948	#else
2949	/ On e.g. IA-64 or Alpha, relative relocations are processed*
2950	only if library is loaded to different address than p_vaddr. /*
2951	if (l->l_addr != `0` && l->l_info[VERSYMIDX (DT_RELACOUNT)])
2952	#endif
2953	num_relative_relocations
2954	+= l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
2955	}
2956	}
2957
2958	_dl_debug_printf (" number of relocations: %lu\n"
2959	" number of relocations from cache: %lu\n"
2960	" number of relative relocations: %lu\n",
2961	GL(dl_num_relocations),
2962	GL(dl_num_cache_relocations),
2963	num_relative_relocations);
2964
2965	#if HP_TIMING_INLINE
2966	print_statistics_item (" time needed to load objects",
2967	load_time, *rtld_total_timep);
2968	#endif
2969	}
2970

Definitions

rtld_timer_start
rtld_timer_stop
rtld_timer_accum
_dl_argc
_dl_argv
_dl_skip_args
__pointer_chk_guard_local
dso_name_valid_for_suid
audit_list_init
audit_list_add_string
audit_list_add_dynamic_tag
audit_list_next
audit_list_count
dl_main_state_init
_rtld_global
_rtld_local
_rtld_global_ro
_rtld_local_ro
_dl_rtld_libname
_dl_rtld_libname2
relocate_time
load_time
start_time
_dl_start_final
_dl_start
relocate_args
map_args
dlmopen_args
lookup_args
version_check_args
relocate_doit
map_doit
dlmopen_doit
lookup_doit
version_check_doit
find_needed
match_version
tls_init_tp_called
init_tls
do_preload
rtld_lock_default_lock_recursive
rtld_lock_default_unlock_recursive
security_init
handle_preload_list
unload_audit_module
report_audit_module_load_error
load_audit_module
notify_audit_modules_of_loaded_object
load_audit_modules
dl_main
print_unresolved
print_missing_version
process_dl_debug
process_envvars
print_statistics_item

Browse the source code of glibc/elf/rtld.c

Definitions