rtld.c source code [glibc_src_2.30/elf/rtld.c]

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

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