1/* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _LDSODEFS_H
20#define _LDSODEFS_H 1
21
22#include <features.h>
23
24#include <stdbool.h>
25#define __need_size_t
26#define __need_NULL
27#include <stddef.h>
28#include <string.h>
29#include <stdint.h>
30
31#include <elf.h>
32#include <dlfcn.h>
33#include <fpu_control.h>
34#include <sys/mman.h>
35#include <link.h>
36#include <dl-lookupcfg.h>
37#include <dl-sysdep.h>
38#include <libc-lock.h>
39#include <hp-timing.h>
40#include <tls.h>
41#include <list_t.h>
42
43__BEGIN_DECLS
44
45#define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
46#define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
47 + DT_EXTRANUM + DT_VALTAGIDX (tag))
48#define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
49 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
50
51/* Type of GNU hash which the machine uses. */
52#ifndef ELF_MACHINE_GNU_HASH_ADDRIDX
53# define ELF_MACHINE_GNU_HASH_ADDRIDX ADDRIDX (DT_GNU_HASH)
54#endif
55
56/* Calculate the index of a symbol in GNU hash. */
57#ifndef ELF_MACHINE_HASH_SYMIDX
58# define ELF_MACHINE_HASH_SYMIDX(map, hasharr) \
59 ((hasharr) - (map)->l_gnu_chain_zero)
60#endif
61
62/* Setup MIPS xhash. Defined only for MIPS. */
63#ifndef ELF_MACHINE_XHASH_SETUP
64# define ELF_MACHINE_XHASH_SETUP(hash32, symbias, map) \
65 ((void) (hash32), (void) (symbias), (void) (map))
66#endif
67
68/* We use this macro to refer to ELF types independent of the native wordsize.
69 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
70#define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
71
72/* All references to the value of l_info[DT_PLTGOT],
73 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
74 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
75 have to be accessed via the D_PTR macro. The macro is needed since for
76 most architectures the entry is already relocated - but for some not
77 and we need to relocate at access time. */
78#ifdef DL_RO_DYN_SECTION
79# define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
80#else
81# define D_PTR(map, i) (map)->i->d_un.d_ptr
82#endif
83
84/* Result of the lookup functions and how to retrieve the base address. */
85typedef struct link_map *lookup_t;
86#define LOOKUP_VALUE(map) map
87#define LOOKUP_VALUE_ADDRESS(map, set) ((set) || (map) ? (map)->l_addr : 0)
88
89/* Calculate the address of symbol REF using the base address from map MAP,
90 if non-NULL. Don't check for NULL map if MAP_SET is TRUE. */
91#define SYMBOL_ADDRESS(map, ref, map_set) \
92 ((ref) == NULL ? 0 \
93 : (__glibc_unlikely ((ref)->st_shndx == SHN_ABS) ? 0 \
94 : LOOKUP_VALUE_ADDRESS (map, map_set)) + (ref)->st_value)
95
96/* Type of a constructor function, in DT_INIT, DT_INIT_ARRAY,
97 DT_PREINIT_ARRAY. */
98typedef void (*dl_init_t) (int, char **, char **);
99
100/* On some architectures a pointer to a function is not just a pointer
101 to the actual code of the function but rather an architecture
102 specific descriptor. */
103#ifndef ELF_FUNCTION_PTR_IS_SPECIAL
104# define DL_SYMBOL_ADDRESS(map, ref) \
105 (void *) SYMBOL_ADDRESS (map, ref, false)
106# define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
107# define DL_CALL_DT_INIT(map, start, argc, argv, env) \
108 ((dl_init_t) (start)) (argc, argv, env)
109# define DL_CALL_DT_FINI(map, start) ((fini_t) (start)) ()
110#endif
111
112/* On some architectures dladdr can't use st_size of all symbols this way. */
113#define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
114 ((ADDR) >= (L)->l_addr + (SYM)->st_value \
115 && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
116 && (ADDR) == (L)->l_addr + (SYM)->st_value) \
117 || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
118 && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
119
120/* According to the ELF gABI no STV_HIDDEN or STV_INTERNAL symbols are
121 expected to be present in dynamic symbol tables as they should have
122 been either removed or converted to STB_LOCAL binding by the static
123 linker. However some GNU binutils versions produce such symbols in
124 some cases. To prevent such symbols present in a buggy binary from
125 preempting global symbols we filter them out with this predicate. */
126static __always_inline bool
127dl_symbol_visibility_binds_local_p (const ElfW(Sym) *sym)
128{
129 return (ELFW(ST_VISIBILITY) (sym->st_other) == STV_HIDDEN
130 || ELFW(ST_VISIBILITY) (sym->st_other) == STV_INTERNAL);
131}
132
133/* Unmap a loaded object, called by _dl_close (). */
134#ifndef DL_UNMAP_IS_SPECIAL
135# define DL_UNMAP(map) _dl_unmap_segments (map)
136#endif
137
138/* Reloc type classes as returned by elf_machine_type_class().
139 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
140 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
141 satisfied by any symbol in the executable. Some architectures do
142 not support copy relocations. In this case we define the macro to
143 zero so that the code for handling them gets automatically optimized
144 out. ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA means address of protected
145 data defined in the shared library may be external, i.e., due to copy
146 relocation. */
147#define ELF_RTYPE_CLASS_PLT 1
148#ifndef DL_NO_COPY_RELOCS
149# define ELF_RTYPE_CLASS_COPY 2
150#else
151# define ELF_RTYPE_CLASS_COPY 0
152#endif
153/* If DL_EXTERN_PROTECTED_DATA is defined, address of protected data
154 defined in the shared library may be external, i.e., due to copy
155 relocation. */
156#ifdef DL_EXTERN_PROTECTED_DATA
157# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 4
158#else
159# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 0
160#endif
161
162/* ELF uses the PF_x macros to specify the segment permissions, mmap
163 uses PROT_xxx. In most cases the three macros have the values 1, 2,
164 and 3 but not in a matching order. The following macros allows
165 converting from the PF_x values to PROT_xxx values. */
166#define PF_TO_PROT \
167 ((PROT_READ << (PF_R * 4)) \
168 | (PROT_WRITE << (PF_W * 4)) \
169 | (PROT_EXEC << (PF_X * 4)) \
170 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
171 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
172 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
173 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
174
175/* The filename itself, or the main program name, if available. */
176#define DSO_FILENAME(name) ((name)[0] ? (name) \
177 : (rtld_progname ?: "<main program>"))
178
179#define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
180
181/* For the version handling we need an array with only names and their
182 hash values. */
183struct r_found_version
184 {
185 const char *name;
186 ElfW(Word) hash;
187
188 int hidden;
189 const char *filename;
190 };
191
192/* We want to cache information about the searches for shared objects. */
193
194enum r_dir_status { unknown, nonexisting, existing };
195
196struct r_search_path_elem
197 {
198 /* This link is only used in the `all_dirs' member of `r_search_path'. */
199 struct r_search_path_elem *next;
200
201 /* Strings saying where the definition came from. */
202 const char *what;
203 const char *where;
204
205 /* Basename for this search path element. The string must end with
206 a slash character. */
207 const char *dirname;
208 size_t dirnamelen;
209
210 enum r_dir_status status[0];
211 };
212
213struct r_strlenpair
214 {
215 const char *str;
216 size_t len;
217 };
218
219
220/* A data structure for a simple single linked list of strings. */
221struct libname_list
222 {
223 const char *name; /* Name requested (before search). */
224 struct libname_list *next; /* Link to next name for this object. */
225 int dont_free; /* Flag whether this element should be freed
226 if the object is not entirely unloaded. */
227 };
228
229
230/* Bit masks for the objects which valid callers can come from to
231 functions with restricted interface. */
232enum allowmask
233 {
234 allow_libc = 1,
235 allow_libdl = 2,
236 allow_libpthread = 4,
237 allow_ldso = 8
238 };
239
240
241struct audit_ifaces
242{
243 void (*activity) (uintptr_t *, unsigned int);
244 char *(*objsearch) (const char *, uintptr_t *, unsigned int);
245 unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
246 void (*preinit) (uintptr_t *);
247 union
248 {
249 uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
250 uintptr_t *, unsigned int *, const char *);
251 uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
252 uintptr_t *, unsigned int *, const char *);
253 };
254 union
255 {
256#ifdef ARCH_PLTENTER_MEMBERS
257 ARCH_PLTENTER_MEMBERS;
258#endif
259 };
260 union
261 {
262#ifdef ARCH_PLTEXIT_MEMBERS
263 ARCH_PLTEXIT_MEMBERS;
264#endif
265 };
266 unsigned int (*objclose) (uintptr_t *);
267
268 struct audit_ifaces *next;
269};
270
271
272/* Test whether given NAME matches any of the names of the given object. */
273extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
274 attribute_hidden;
275
276/* Compute next higher prime number. */
277extern unsigned long int _dl_higher_prime_number (unsigned long int n)
278 attribute_hidden;
279
280/* A stripped down strtoul-like implementation. */
281uint64_t _dl_strtoul (const char *, char **) attribute_hidden;
282
283/* Function used as argument for `_dl_receive_error' function. The
284 arguments are the error code, error string, and the objname the
285 error occurred in. */
286typedef void (*receiver_fct) (int, const char *, const char *);
287
288/* Internal functions of the run-time dynamic linker.
289 These can be accessed if you link again the dynamic linker
290 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
291 but are not normally of interest to user programs.
292
293 The `-ldl' library functions in <dlfcn.h> provide a simple
294 user interface to run-time dynamic linking. */
295
296
297#ifndef SHARED
298# define EXTERN extern
299# define GL(name) _##name
300#else
301# define EXTERN
302# if IS_IN (rtld)
303# define GL(name) _rtld_local._##name
304# else
305# define GL(name) _rtld_global._##name
306# endif
307struct rtld_global
308{
309#endif
310 /* Don't change the order of the following elements. 'dl_loaded'
311 must remain the first element. Forever. */
312
313/* Non-shared code has no support for multiple namespaces. */
314#ifdef SHARED
315# define DL_NNS 16
316#else
317# define DL_NNS 1
318#endif
319 EXTERN struct link_namespaces
320 {
321 /* A pointer to the map for the main map. */
322 struct link_map *_ns_loaded;
323 /* Number of object in the _dl_loaded list. */
324 unsigned int _ns_nloaded;
325 /* Direct pointer to the searchlist of the main object. */
326 struct r_scope_elem *_ns_main_searchlist;
327 /* This is zero at program start to signal that the global scope map is
328 allocated by rtld. Later it keeps the size of the map. It might be
329 reset if in _dl_close if the last global object is removed. */
330 unsigned int _ns_global_scope_alloc;
331
332 /* During dlopen, this is the number of objects that still need to
333 be added to the global scope map. It has to be taken into
334 account when resizing the map, for future map additions after
335 recursive dlopen calls from ELF constructors. */
336 unsigned int _ns_global_scope_pending_adds;
337
338 /* Once libc.so has been loaded into the namespace, this points to
339 its link map. */
340 struct link_map *libc_map;
341
342 /* Search table for unique objects. */
343 struct unique_sym_table
344 {
345 __rtld_lock_define_recursive (, lock)
346 struct unique_sym
347 {
348 uint32_t hashval;
349 const char *name;
350 const ElfW(Sym) *sym;
351 const struct link_map *map;
352 } *entries;
353 size_t size;
354 size_t n_elements;
355 void (*free) (void *);
356 } _ns_unique_sym_table;
357 /* Keep track of changes to each namespace' list. */
358 struct r_debug _ns_debug;
359 } _dl_ns[DL_NNS];
360 /* One higher than index of last used namespace. */
361 EXTERN size_t _dl_nns;
362
363 /* During the program run we must not modify the global data of
364 loaded shared object simultanously in two threads. Therefore we
365 protect `_dl_open' and `_dl_close' in dl-close.c.
366
367 This must be a recursive lock since the initializer function of
368 the loaded object might as well require a call to this function.
369 At this time it is not anymore a problem to modify the tables. */
370 __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
371 /* This lock is used to keep __dl_iterate_phdr from inspecting the
372 list of loaded objects while an object is added to or removed
373 from that list. */
374 __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
375
376 /* Incremented whenever something may have been added to dl_loaded. */
377 EXTERN unsigned long long _dl_load_adds;
378
379 /* The object to be initialized first. */
380 EXTERN struct link_map *_dl_initfirst;
381
382 /* Map of shared object to be profiled. */
383 EXTERN struct link_map *_dl_profile_map;
384
385 /* Counters for the number of relocations performed. */
386 EXTERN unsigned long int _dl_num_relocations;
387 EXTERN unsigned long int _dl_num_cache_relocations;
388
389 /* List of search directories. */
390 EXTERN struct r_search_path_elem *_dl_all_dirs;
391
392 /* Structure describing the dynamic linker itself. */
393 EXTERN struct link_map _dl_rtld_map;
394#ifdef SHARED
395 /* Used to store the audit information for the link map of the
396 dynamic loader. */
397 struct auditstate _dl_rtld_auditstate[DL_NNS];
398#endif
399
400#if !PTHREAD_IN_LIBC && defined SHARED \
401 && defined __rtld_lock_default_lock_recursive
402 EXTERN void (*_dl_rtld_lock_recursive) (void *);
403 EXTERN void (*_dl_rtld_unlock_recursive) (void *);
404#endif
405
406 /* Get architecture specific definitions. */
407#define PROCINFO_DECL
408#ifndef PROCINFO_CLASS
409# define PROCINFO_CLASS EXTERN
410#endif
411#include <dl-procruntime.c>
412
413#if !PTHREAD_IN_LIBC
414 /* If loading a shared object requires that we make the stack executable
415 when it was not, we do it by calling this function.
416 It returns an errno code or zero on success. */
417 EXTERN int (*_dl_make_stack_executable_hook) (void **);
418#endif
419
420 /* Prevailing state of the stack, PF_X indicating it's executable. */
421 EXTERN ElfW(Word) _dl_stack_flags;
422
423 /* Flag signalling whether there are gaps in the module ID allocation. */
424 EXTERN bool _dl_tls_dtv_gaps;
425 /* Highest dtv index currently needed. */
426 EXTERN size_t _dl_tls_max_dtv_idx;
427 /* Information about the dtv slots. */
428 EXTERN struct dtv_slotinfo_list
429 {
430 size_t len;
431 struct dtv_slotinfo_list *next;
432 struct dtv_slotinfo
433 {
434 size_t gen;
435 struct link_map *map;
436 } slotinfo[];
437 } *_dl_tls_dtv_slotinfo_list;
438 /* Number of modules in the static TLS block. */
439 EXTERN size_t _dl_tls_static_nelem;
440 /* Size actually allocated in the static TLS block. */
441 EXTERN size_t _dl_tls_static_used;
442 /* Remaining amount of static TLS that may be used for optimizing
443 dynamic TLS access (e.g. with TLSDESC). */
444 EXTERN size_t _dl_tls_static_optional;
445
446/* Number of additional entries in the slotinfo array of each slotinfo
447 list element. A large number makes it almost certain take we never
448 have to iterate beyond the first element in the slotinfo list. */
449#define TLS_SLOTINFO_SURPLUS (62)
450
451/* Number of additional slots in the dtv allocated. */
452#define DTV_SURPLUS (14)
453
454 /* Initial dtv of the main thread, not allocated with normal malloc. */
455 EXTERN void *_dl_initial_dtv;
456 /* Generation counter for the dtv. */
457 EXTERN size_t _dl_tls_generation;
458
459#if !THREAD_GSCOPE_IN_TCB
460 EXTERN void (*_dl_init_static_tls) (struct link_map *);
461#endif
462
463 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
464 EXTERN struct dl_scope_free_list
465 {
466 size_t count;
467 void *list[50];
468 } *_dl_scope_free_list;
469#if THREAD_GSCOPE_IN_TCB
470 /* List of active thread stacks, with memory managed by glibc. */
471 EXTERN list_t _dl_stack_used;
472
473 /* List of thread stacks that were allocated by the application. */
474 EXTERN list_t _dl_stack_user;
475
476 /* List of queued thread stacks. */
477 EXTERN list_t _dl_stack_cache;
478
479 /* Total size of all stacks in the cache (sum over stackblock_size). */
480 EXTERN size_t _dl_stack_cache_actsize;
481
482 /* We need to record what list operations we are going to do so
483 that, in case of an asynchronous interruption due to a fork()
484 call, we can correct for the work. */
485 EXTERN uintptr_t _dl_in_flight_stack;
486
487 /* Mutex protecting the stack lists. */
488 EXTERN int _dl_stack_cache_lock;
489#else
490 EXTERN int _dl_thread_gscope_count;
491#endif
492#ifdef SHARED
493};
494# define __rtld_global_attribute__
495# if IS_IN (rtld)
496# ifdef HAVE_SDATA_SECTION
497# define __rtld_local_attribute__ \
498 __attribute__ ((visibility ("hidden"), section (".sdata")))
499# undef __rtld_global_attribute__
500# define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
501# else
502# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
503# endif
504extern struct rtld_global _rtld_local __rtld_local_attribute__;
505# undef __rtld_local_attribute__
506# endif
507extern struct rtld_global _rtld_global __rtld_global_attribute__;
508# undef __rtld_global_attribute__
509#endif
510
511#ifndef SHARED
512# define GLRO(name) _##name
513#else
514# if IS_IN (rtld)
515# define GLRO(name) _rtld_local_ro._##name
516# else
517# define GLRO(name) _rtld_global_ro._##name
518# endif
519struct rtld_global_ro
520{
521#endif
522
523 /* If nonzero the appropriate debug information is printed. */
524 EXTERN int _dl_debug_mask;
525#define DL_DEBUG_LIBS (1 << 0)
526#define DL_DEBUG_IMPCALLS (1 << 1)
527#define DL_DEBUG_BINDINGS (1 << 2)
528#define DL_DEBUG_SYMBOLS (1 << 3)
529#define DL_DEBUG_VERSIONS (1 << 4)
530#define DL_DEBUG_RELOC (1 << 5)
531#define DL_DEBUG_FILES (1 << 6)
532#define DL_DEBUG_STATISTICS (1 << 7)
533#define DL_DEBUG_UNUSED (1 << 8)
534#define DL_DEBUG_SCOPES (1 << 9)
535/* These two are used only internally. */
536#define DL_DEBUG_HELP (1 << 10)
537#define DL_DEBUG_PRELINK (1 << 11)
538
539 /* OS version. */
540 EXTERN unsigned int _dl_osversion;
541 /* Platform name. */
542 EXTERN const char *_dl_platform;
543 EXTERN size_t _dl_platformlen;
544
545 /* Cached value of `getpagesize ()'. */
546 EXTERN size_t _dl_pagesize;
547
548 /* Cached value of `sysconf (_SC_MINSIGSTKSZ)'. */
549 EXTERN size_t _dl_minsigstacksize;
550
551 /* Do we read from ld.so.cache? */
552 EXTERN int _dl_inhibit_cache;
553
554 /* Copy of the content of `_dl_main_searchlist' at startup time. */
555 EXTERN struct r_scope_elem _dl_initial_searchlist;
556
557 /* CLK_TCK as reported by the kernel. */
558 EXTERN int _dl_clktck;
559
560 /* If nonzero print warnings messages. */
561 EXTERN int _dl_verbose;
562
563 /* File descriptor to write debug messages to. */
564 EXTERN int _dl_debug_fd;
565
566 /* Do we do lazy relocations? */
567 EXTERN int _dl_lazy;
568
569 /* Nonzero if runtime lookups should not update the .got/.plt. */
570 EXTERN int _dl_bind_not;
571
572 /* Nonzero if references should be treated as weak during runtime
573 linking. */
574 EXTERN int _dl_dynamic_weak;
575
576 /* Default floating-point control word. */
577 EXTERN fpu_control_t _dl_fpu_control;
578
579 /* Expected cache ID. */
580 EXTERN int _dl_correct_cache_id;
581
582 /* Mask for hardware capabilities that are available. */
583 EXTERN uint64_t _dl_hwcap;
584
585#if !HAVE_TUNABLES
586 /* Mask for important hardware capabilities we honour. */
587 EXTERN uint64_t _dl_hwcap_mask;
588#endif
589
590#ifdef HAVE_AUX_VECTOR
591 /* Pointer to the auxv list supplied to the program at startup. */
592 EXTERN ElfW(auxv_t) *_dl_auxv;
593#endif
594
595 /* Get architecture specific definitions. */
596#include <dl-procinfo.c>
597
598 /* Names of shared object for which the RPATH should be ignored. */
599 EXTERN const char *_dl_inhibit_rpath;
600
601 /* Location of the binary. */
602 EXTERN const char *_dl_origin_path;
603
604 /* -1 if the dynamic linker should honor library load bias,
605 0 if not, -2 use the default (honor biases for normal
606 binaries, don't honor for PIEs). */
607 EXTERN ElfW(Addr) _dl_use_load_bias;
608
609 /* Size of the static TLS block. */
610 EXTERN size_t _dl_tls_static_size;
611
612 /* Alignment requirement of the static TLS block. */
613 EXTERN size_t _dl_tls_static_align;
614
615 /* Size of surplus space in the static TLS area for dynamically
616 loaded modules with IE-model TLS or for TLSDESC optimization.
617 See comments in elf/dl-tls.c where it is initialized. */
618 EXTERN size_t _dl_tls_static_surplus;
619
620 /* Name of the shared object to be profiled (if any). */
621 EXTERN const char *_dl_profile;
622 /* Filename of the output file. */
623 EXTERN const char *_dl_profile_output;
624 /* Name of the object we want to trace the prelinking. */
625 EXTERN const char *_dl_trace_prelink;
626 /* Map of shared object to be prelink traced. */
627 EXTERN struct link_map *_dl_trace_prelink_map;
628
629 /* All search directories defined at startup. This is assigned a
630 non-NULL pointer by the ld.so startup code (after initialization
631 to NULL), so this can also serve as an indicator whether a copy
632 of ld.so is initialized and active. See the rtld_active function
633 below. */
634 EXTERN struct r_search_path_elem *_dl_init_all_dirs;
635
636#ifdef NEED_DL_SYSINFO
637 /* Syscall handling improvements. This is very specific to x86. */
638 EXTERN uintptr_t _dl_sysinfo;
639#endif
640
641#ifdef NEED_DL_SYSINFO_DSO
642 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
643 This points to its ELF header. */
644 EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
645
646 /* At startup time we set up the normal DSO data structure for it,
647 and this points to it. */
648 EXTERN struct link_map *_dl_sysinfo_map;
649
650# define PROCINFO_DECL
651# ifndef PROCINFO_CLASS
652# define PROCINFO_CLASS EXTERN
653# endif
654# include <dl-vdso-setup.c>
655#endif
656
657 /* Mask for more hardware capabilities that are available on some
658 platforms. */
659 EXTERN uint64_t _dl_hwcap2;
660
661#ifdef SHARED
662 /* We add a function table to _rtld_global which is then used to
663 call the function instead of going through the PLT. The result
664 is that we can avoid exporting the functions and we do not jump
665 PLT relocations in libc.so. */
666 void (*_dl_debug_printf) (const char *, ...)
667 __attribute__ ((__format__ (__printf__, 1, 2)));
668 void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
669 lookup_t (*_dl_lookup_symbol_x) (const char *, struct link_map *,
670 const ElfW(Sym) **, struct r_scope_elem *[],
671 const struct r_found_version *, int, int,
672 struct link_map *);
673 void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
674 Lmid_t nsid, int argc, char *argv[], char *env[]);
675 void (*_dl_close) (void *map);
676 /* libdl in a secondary namespace (after dlopen) must use
677 _dl_catch_error from the main namespace, so it has to be
678 exported in some way. */
679 int (*_dl_catch_error) (const char **objname, const char **errstring,
680 bool *mallocedp, void (*operate) (void *),
681 void *args);
682 /* libdl in a secondary namespace must use free from the base
683 namespace. */
684 void (*_dl_error_free) (void *);
685 void *(*_dl_tls_get_addr_soft) (struct link_map *);
686#ifdef HAVE_DL_DISCOVER_OSVERSION
687 int (*_dl_discover_osversion) (void);
688#endif
689
690 /* Dynamic linker operations used after static dlopen. */
691 const struct dlfcn_hook *_dl_dlfcn_hook;
692
693 /* List of auditing interfaces. */
694 struct audit_ifaces *_dl_audit;
695 unsigned int _dl_naudit;
696};
697# define __rtld_global_attribute__
698# if IS_IN (rtld)
699# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
700extern struct rtld_global_ro _rtld_local_ro
701 attribute_relro __rtld_local_attribute__;
702extern struct rtld_global_ro _rtld_global_ro
703 attribute_relro __rtld_global_attribute__;
704# undef __rtld_local_attribute__
705# else
706/* We cheat a bit here. We declare the variable as as const even
707 though it is at startup. */
708extern const struct rtld_global_ro _rtld_global_ro
709 attribute_relro __rtld_global_attribute__;
710# endif
711# undef __rtld_global_attribute__
712#endif
713#undef EXTERN
714
715#ifndef SHARED
716/* dl-support.c defines these and initializes them early on. */
717extern const ElfW(Phdr) *_dl_phdr;
718extern size_t _dl_phnum;
719#endif
720
721#if PTHREAD_IN_LIBC
722/* This function changes the permissions of all stacks (not just those
723 of the main stack). */
724int _dl_make_stacks_executable (void **stack_endp) attribute_hidden;
725#else
726/* This is the initial value of GL(dl_make_stack_executable_hook).
727 A threads library can change it. The ld.so implementation changes
728 the permissions of the main stack only. */
729extern int _dl_make_stack_executable (void **stack_endp);
730rtld_hidden_proto (_dl_make_stack_executable)
731#endif
732
733/* Variable pointing to the end of the stack (or close to it). This value
734 must be constant over the runtime of the application. Some programs
735 might use the variable which results in copy relocations on some
736 platforms. But this does not matter, ld.so can always use the local
737 copy. */
738extern void *__libc_stack_end
739#ifndef LIBC_STACK_END_NOT_RELRO
740 attribute_relro
741#endif
742 ;
743rtld_hidden_proto (__libc_stack_end)
744
745/* Parameters passed to the dynamic linker. */
746extern int _dl_argc attribute_hidden attribute_relro;
747extern char **_dl_argv
748#ifndef DL_ARGV_NOT_RELRO
749 attribute_relro
750#endif
751 ;
752rtld_hidden_proto (_dl_argv)
753#if IS_IN (rtld)
754extern unsigned int _dl_skip_args attribute_hidden
755# ifndef DL_ARGV_NOT_RELRO
756 attribute_relro
757# endif
758 ;
759extern unsigned int _dl_skip_args_internal attribute_hidden
760# ifndef DL_ARGV_NOT_RELRO
761 attribute_relro
762# endif
763 ;
764#endif
765#define rtld_progname _dl_argv[0]
766
767/* Flag set at startup and cleared when the last initializer has run. */
768extern int _dl_starting_up;
769weak_extern (_dl_starting_up)
770rtld_hidden_proto (_dl_starting_up)
771
772/* Random data provided by the kernel. */
773extern void *_dl_random attribute_hidden attribute_relro;
774
775/* Write message on the debug file descriptor. The parameters are
776 interpreted as for a `printf' call. All the lines start with a
777 tag showing the PID. */
778extern void _dl_debug_printf (const char *fmt, ...)
779 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
780
781/* Write message on the debug file descriptor. The parameters are
782 interpreted as for a `printf' call. All the lines buf the first
783 start with a tag showing the PID. */
784extern void _dl_debug_printf_c (const char *fmt, ...)
785 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
786
787
788/* Write a message on the specified descriptor FD. The parameters are
789 interpreted as for a `printf' call. */
790#if IS_IN (rtld) || !defined (SHARED)
791extern void _dl_dprintf (int fd, const char *fmt, ...)
792 __attribute__ ((__format__ (__printf__, 2, 3)))
793 attribute_hidden;
794#else
795__attribute__ ((always_inline, __format__ (__printf__, 2, 3)))
796static inline void
797_dl_dprintf (int fd, const char *fmt, ...)
798{
799 /* Use local declaration to avoid includign <stdio.h>. */
800 extern int __dprintf(int fd, const char *format, ...) attribute_hidden;
801 __dprintf (fd, fmt, __builtin_va_arg_pack ());
802}
803#endif
804
805/* Write LENGTH bytes at BUFFER to FD, like write. Returns the number
806 of bytes written on success, or a negative error constant on
807 failure. */
808ssize_t _dl_write (int fd, const void *buffer, size_t length)
809 attribute_hidden;
810
811/* Write a message on the specified descriptor standard output. The
812 parameters are interpreted as for a `printf' call. */
813void _dl_printf (const char *fmt, ...)
814 attribute_hidden __attribute__ ((__format__ (__printf__, 1, 2)));
815
816/* Write a message on the specified descriptor standard error. The
817 parameters are interpreted as for a `printf' call. */
818void _dl_error_printf (const char *fmt, ...)
819 attribute_hidden __attribute__ ((__format__ (__printf__, 1, 2)));
820
821/* Write a message on the specified descriptor standard error and exit
822 the program. The parameters are interpreted as for a `printf' call. */
823void _dl_fatal_printf (const char *fmt, ...)
824 __attribute__ ((__format__ (__printf__, 1, 2), __noreturn__));
825rtld_hidden_proto (_dl_fatal_printf)
826
827/* An exception raised by the _dl_signal_error function family and
828 caught by _dl_catch_error function family. Exceptions themselves
829 are copied as part of the raise operation, but the strings are
830 not. */
831struct dl_exception
832{
833 const char *objname;
834 const char *errstring;
835
836 /* This buffer typically stores both objname and errstring
837 above. */
838 char *message_buffer;
839};
840
841/* Creates a new exception. This calls malloc; if allocation fails,
842 dummy values are inserted. OBJECT is the name of the problematical
843 shared object, or null if its a general problem. ERRSTRING is a
844 string describing the specific problem. */
845void _dl_exception_create (struct dl_exception *, const char *object,
846 const char *errstring)
847 __attribute__ ((nonnull (1, 3)));
848rtld_hidden_proto (_dl_exception_create)
849
850/* Used internally to implement dlerror message freeing. See
851 include/dlfcn.h and dlfcn/dlerror.c. */
852void _dl_error_free (void *ptr) attribute_hidden;
853
854/* Like _dl_exception_create, but create errstring from a format
855 string FMT. Currently, only "%s" and "%%" are supported as format
856 directives. */
857void _dl_exception_create_format (struct dl_exception *, const char *objname,
858 const char *fmt, ...)
859 __attribute__ ((nonnull (1, 3), format (printf, 3, 4)));
860rtld_hidden_proto (_dl_exception_create_format)
861
862/* Deallocate the exception, freeing allocated buffers (if
863 possible). */
864void _dl_exception_free (struct dl_exception *)
865 __attribute__ ((nonnull (1)));
866rtld_hidden_proto (_dl_exception_free)
867
868/* This function is called by all the internal dynamic linker
869 functions when they encounter an error. ERRCODE is either an
870 `errno' code or zero; it specifies the return value of
871 _dl_catch_error. OCCASION is included in the error message if the
872 process is terminated immediately. */
873void _dl_signal_exception (int errcode, struct dl_exception *,
874 const char *occasion)
875 __attribute__ ((__noreturn__));
876libc_hidden_proto (_dl_signal_exception)
877
878/* Like _dl_signal_exception, but creates the exception first. */
879extern void _dl_signal_error (int errcode, const char *object,
880 const char *occasion, const char *errstring)
881 __attribute__ ((__noreturn__));
882libc_hidden_proto (_dl_signal_error)
883
884/* Like _dl_signal_exception, but may return when called in the
885 context of _dl_receive_error. This is only used during ld.so
886 bootstrap. In static and profiled builds, this is equivalent to
887 _dl_signal_exception. */
888#if IS_IN (rtld)
889extern void _dl_signal_cexception (int errcode, struct dl_exception *,
890 const char *occasion) attribute_hidden;
891#else
892__attribute__ ((always_inline))
893static inline void
894_dl_signal_cexception (int errcode, struct dl_exception *exception,
895 const char *occasion)
896{
897 _dl_signal_exception (errcode, exception, occasion);
898}
899#endif
900
901/* See _dl_signal_cexception above. */
902#if IS_IN (rtld)
903extern void _dl_signal_cerror (int errcode, const char *object,
904 const char *occasion, const char *errstring)
905 attribute_hidden;
906#else
907__attribute__ ((always_inline))
908static inline void
909_dl_signal_cerror (int errcode, const char *object,
910 const char *occasion, const char *errstring)
911{
912 _dl_signal_error (errcode, object, occasion, errstring);
913}
914#endif
915
916/* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
917 `_dl_catch_error' the operation is resumed after the OPERATE
918 function returns.
919 ARGS is passed as argument to OPERATE. */
920extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
921 void *args) attribute_hidden;
922
923/* Call OPERATE, catching errors from `_dl_signal_error' and related
924 functions. If there is no error, *ERRSTRING is set to null. If
925 there is an error, *ERRSTRING is set to a string constructed from
926 the strings passed to _dl_signal_error, and the error code passed
927 is the return value and *OBJNAME is set to the object name which
928 experienced the problems. ERRSTRING if nonzero points to a
929 malloc'ed string which the caller has to free after use. ARGS is
930 passed as argument to OPERATE. MALLOCEDP is set to true only if
931 the returned string is allocated using the libc's malloc. */
932extern int _dl_catch_error (const char **objname, const char **errstring,
933 bool *mallocedp, void (*operate) (void *),
934 void *args);
935libc_hidden_proto (_dl_catch_error)
936
937/* Used for initializing GLRO (_dl_catch_error). */
938extern __typeof__ (_dl_catch_error) _rtld_catch_error attribute_hidden;
939
940/* Call OPERATE (ARGS). If no error occurs, set *EXCEPTION to zero.
941 Otherwise, store a copy of the raised exception in *EXCEPTION,
942 which has to be freed by _dl_exception_free. As a special case, if
943 EXCEPTION is null, call OPERATE (ARGS) with exception handling
944 disabled (so that exceptions are fatal). */
945int _dl_catch_exception (struct dl_exception *exception,
946 void (*operate) (void *), void *args);
947libc_hidden_proto (_dl_catch_exception)
948
949/* Open the shared object NAME and map in its segments.
950 LOADER's DT_RPATH is used in searching for NAME.
951 If the object is already opened, returns its existing map. */
952extern struct link_map *_dl_map_object (struct link_map *loader,
953 const char *name,
954 int type, int trace_mode, int mode,
955 Lmid_t nsid) attribute_hidden;
956
957/* Call _dl_map_object on the dependencies of MAP, and set up
958 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
959 loaded objects that will be inserted into MAP->l_searchlist after MAP
960 but before its dependencies. */
961extern void _dl_map_object_deps (struct link_map *map,
962 struct link_map **preloads,
963 unsigned int npreloads, int trace_mode,
964 int open_mode)
965 attribute_hidden;
966
967/* Cache the locations of MAP's hash table. */
968extern void _dl_setup_hash (struct link_map *map) attribute_hidden;
969
970
971/* Collect the directories in the search path for LOADER's dependencies.
972 The data structure is defined in <dlfcn.h>. If COUNTING is true,
973 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
974 by a previous call with COUNTING set, and SI must point to SI->dls_size
975 bytes to be used in filling in the result. */
976extern void _dl_rtld_di_serinfo (struct link_map *loader,
977 Dl_serinfo *si, bool counting);
978
979/* Process PT_GNU_PROPERTY program header PH in module L after
980 PT_LOAD segments are mapped from file FD. */
981void _dl_process_pt_gnu_property (struct link_map *l, int fd,
982 const ElfW(Phdr) *ph);
983
984
985/* Search loaded objects' symbol tables for a definition of the symbol
986 referred to by UNDEF. *SYM is the symbol table entry containing the
987 reference; it is replaced with the defining symbol, and the base load
988 address of the defining object is returned. SYMBOL_SCOPE is a
989 null-terminated list of object scopes to search; each object's
990 l_searchlist (i.e. the segment of the dependency tree starting at that
991 object) is searched in turn. REFERENCE_NAME should name the object
992 containing the reference; it is used in error messages.
993 TYPE_CLASS describes the type of symbol we are looking for. */
994enum
995 {
996 /* If necessary add dependency between user and provider object. */
997 DL_LOOKUP_ADD_DEPENDENCY = 1,
998 /* Return most recent version instead of default version for
999 unversioned lookup. */
1000 DL_LOOKUP_RETURN_NEWEST = 2,
1001 /* Set if dl_lookup* called with GSCOPE lock held. */
1002 DL_LOOKUP_GSCOPE_LOCK = 4,
1003 /* Set if dl_lookup is called for non-lazy relocation processing
1004 from _dl_relocate_object in elf/dl-reloc.c. */
1005 DL_LOOKUP_FOR_RELOCATE = 8,
1006 };
1007
1008/* Lookup versioned symbol. */
1009extern lookup_t _dl_lookup_symbol_x (const char *undef,
1010 struct link_map *undef_map,
1011 const ElfW(Sym) **sym,
1012 struct r_scope_elem *symbol_scope[],
1013 const struct r_found_version *version,
1014 int type_class, int flags,
1015 struct link_map *skip_map)
1016 attribute_hidden;
1017
1018
1019/* Restricted version of _dl_lookup_symbol_x. Searches MAP (and only
1020 MAP) for the symbol UNDEF_NAME, with GNU hash NEW_HASH (computed
1021 with dl_new_hash), symbol version VERSION, and symbol version hash
1022 VERSION_HASH (computed with _dl_elf_hash). Returns a pointer to
1023 the symbol table entry in MAP on success, or NULL on failure. MAP
1024 must have symbol versioning information, or otherwise the result is
1025 undefined. */
1026const ElfW(Sym) *_dl_lookup_direct (struct link_map *map,
1027 const char *undef_name,
1028 uint32_t new_hash,
1029 const char *version,
1030 uint32_t version_hash) attribute_hidden;
1031
1032/* Add the new link_map NEW to the end of the namespace list. */
1033extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
1034 attribute_hidden;
1035
1036/* Allocate a `struct link_map' for a new object being loaded. */
1037extern struct link_map *_dl_new_object (char *realname, const char *libname,
1038 int type, struct link_map *loader,
1039 int mode, Lmid_t nsid)
1040 attribute_hidden;
1041
1042/* Relocate the given object (if it hasn't already been).
1043 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
1044 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
1045extern void _dl_relocate_object (struct link_map *map,
1046 struct r_scope_elem *scope[],
1047 int reloc_mode, int consider_profiling)
1048 attribute_hidden;
1049
1050/* Protect PT_GNU_RELRO area. */
1051extern void _dl_protect_relro (struct link_map *map) attribute_hidden;
1052
1053/* Call _dl_signal_error with a message about an unhandled reloc type.
1054 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
1055 PLT is nonzero if this was a PLT reloc; it just affects the message. */
1056extern void _dl_reloc_bad_type (struct link_map *map,
1057 unsigned int type, int plt)
1058 attribute_hidden __attribute__ ((__noreturn__));
1059
1060/* Resolve conflicts if prelinking. */
1061extern void _dl_resolve_conflicts (struct link_map *l,
1062 ElfW(Rela) *conflict,
1063 ElfW(Rela) *conflictend)
1064 attribute_hidden;
1065
1066/* Check the version dependencies of all objects available through
1067 MAP. If VERBOSE print some more diagnostics. */
1068extern int _dl_check_all_versions (struct link_map *map, int verbose,
1069 int trace_mode) attribute_hidden;
1070
1071/* Check the version dependencies for MAP. If VERBOSE print some more
1072 diagnostics. */
1073extern int _dl_check_map_versions (struct link_map *map, int verbose,
1074 int trace_mode) attribute_hidden;
1075
1076/* Initialize the object in SCOPE by calling the constructors with
1077 ARGC, ARGV, and ENV as the parameters. */
1078extern void _dl_init (struct link_map *main_map, int argc, char **argv,
1079 char **env) attribute_hidden;
1080
1081/* Call the finalizer functions of all shared objects whose
1082 initializer functions have completed. */
1083extern void _dl_fini (void) attribute_hidden;
1084
1085/* Sort array MAPS according to dependencies of the contained objects. */
1086extern void _dl_sort_maps (struct link_map **maps, unsigned int nmaps,
1087 char *used, bool for_fini) attribute_hidden;
1088
1089/* The dynamic linker calls this function before and having changing
1090 any shared object mappings. The `r_state' member of `struct r_debug'
1091 says what change is taking place. This function's address is
1092 the value of the `r_brk' member. */
1093extern void _dl_debug_state (void);
1094rtld_hidden_proto (_dl_debug_state)
1095
1096/* Initialize `struct r_debug' if it has not already been done. The
1097 argument is the run-time load address of the dynamic linker, to be put
1098 in the `r_ldbase' member. Returns the address of the structure. */
1099extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
1100 attribute_hidden;
1101
1102/* Initialize the basic data structure for the search paths. SOURCE
1103 is either "LD_LIBRARY_PATH" or "--library-path".
1104 GLIBC_HWCAPS_PREPEND adds additional glibc-hwcaps subdirectories to
1105 search. GLIBC_HWCAPS_MASK is used to filter the built-in
1106 subdirectories if not NULL. */
1107extern void _dl_init_paths (const char *library_path, const char *source,
1108 const char *glibc_hwcaps_prepend,
1109 const char *glibc_hwcaps_mask)
1110 attribute_hidden;
1111
1112/* Gather the information needed to install the profiling tables and start
1113 the timers. */
1114extern void _dl_start_profile (void) attribute_hidden;
1115
1116/* The actual functions used to keep book on the calls. */
1117extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
1118rtld_hidden_proto (_dl_mcount)
1119
1120/* This function is simply a wrapper around the _dl_mcount function
1121 which does not require a FROMPC parameter since this is the
1122 calling function. */
1123extern void _dl_mcount_wrapper (void *selfpc);
1124
1125/* Show the members of the auxiliary array passed up from the kernel. */
1126extern void _dl_show_auxv (void) attribute_hidden;
1127
1128/* Return all environment variables starting with `LD_', one after the
1129 other. */
1130extern char *_dl_next_ld_env_entry (char ***position) attribute_hidden;
1131
1132/* Return an array with the names of the important hardware
1133 capabilities. PREPEND is a colon-separated list of glibc-hwcaps
1134 directories to search first. MASK is a colon-separated list used
1135 to filter the built-in glibc-hwcaps subdirectories. The length of
1136 the array is written to *SZ, and the maximum of all strings length
1137 is written to *MAX_CAPSTRLEN. */
1138const struct r_strlenpair *_dl_important_hwcaps (const char *prepend,
1139 const char *mask,
1140 size_t *sz,
1141 size_t *max_capstrlen)
1142 attribute_hidden;
1143
1144/* Look up NAME in ld.so.cache and return the file name stored there,
1145 or null if none is found. Caller must free returned string. */
1146extern char *_dl_load_cache_lookup (const char *name) attribute_hidden;
1147
1148/* If the system does not support MAP_COPY we cannot leave the file open
1149 all the time since this would create problems when the file is replaced.
1150 Therefore we provide this function to close the file and open it again
1151 once needed. */
1152extern void _dl_unload_cache (void) attribute_hidden;
1153
1154/* System-dependent function to read a file's whole contents in the
1155 most convenient manner available. *SIZEP gets the size of the
1156 file. On error MAP_FAILED is returned. */
1157extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
1158 int prot) attribute_hidden;
1159
1160/* System-specific function to do initial startup for the dynamic linker.
1161 After this, file access calls and getenv must work. This is responsible
1162 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
1163 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
1164extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
1165 void (*dl_main) (const ElfW(Phdr) *phdr,
1166 ElfW(Word) phnum,
1167 ElfW(Addr) *user_entry,
1168 ElfW(auxv_t) *auxv))
1169 attribute_hidden;
1170
1171extern void _dl_sysdep_start_cleanup (void) attribute_hidden;
1172
1173
1174/* Determine next available module ID and set the L l_tls_modid. */
1175extern void _dl_assign_tls_modid (struct link_map *l) attribute_hidden;
1176
1177/* Count the modules with TLS segments. */
1178extern size_t _dl_count_modids (void) attribute_hidden;
1179
1180/* Calculate offset of the TLS blocks in the static TLS block. */
1181extern void _dl_determine_tlsoffset (void) attribute_hidden;
1182
1183/* Calculate the size of the static TLS surplus, when the given
1184 number of audit modules are loaded. */
1185void _dl_tls_static_surplus_init (size_t naudit) attribute_hidden;
1186
1187/* This function is called very early from dl_main to set up TLS and
1188 other thread-related data structures. */
1189void __tls_pre_init_tp (void) attribute_hidden;
1190
1191/* This function is called after processor-specific initialization of
1192 the TCB and thread pointer via TLS_INIT_TP, to complete very early
1193 initialization of the thread library. */
1194void __tls_init_tp (void) attribute_hidden;
1195
1196#ifndef SHARED
1197/* Set up the TCB for statically linked applications. This is called
1198 early during startup because we always use TLS (for errno and the
1199 stack protector, among other things). */
1200void __libc_setup_tls (void);
1201
1202# if ENABLE_STATIC_PIE
1203/* Relocate static executable with PIE. */
1204extern void _dl_relocate_static_pie (void) attribute_hidden;
1205
1206/* Get a pointer to _dl_main_map. */
1207extern struct link_map * _dl_get_dl_main_map (void)
1208 __attribute__ ((visibility ("hidden")));
1209# else
1210# define _dl_relocate_static_pie()
1211# endif
1212#endif
1213
1214/* Initialization of libpthread for statically linked applications.
1215 If libpthread is not linked in, this is an empty function. */
1216void __pthread_initialize_minimal (void) weak_function;
1217
1218/* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
1219extern void *_dl_allocate_tls (void *mem);
1220rtld_hidden_proto (_dl_allocate_tls)
1221
1222/* Get size and alignment requirements of the static TLS block. */
1223extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp);
1224
1225extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
1226
1227/* These are internal entry points to the two halves of _dl_allocate_tls,
1228 only used within rtld.c itself at startup time. */
1229extern void *_dl_allocate_tls_storage (void) attribute_hidden;
1230extern void *_dl_allocate_tls_init (void *);
1231rtld_hidden_proto (_dl_allocate_tls_init)
1232
1233/* Deallocate memory allocated with _dl_allocate_tls. */
1234extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb);
1235rtld_hidden_proto (_dl_deallocate_tls)
1236
1237extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
1238
1239/* Find origin of the executable. */
1240extern const char *_dl_get_origin (void) attribute_hidden;
1241
1242/* Count DSTs. */
1243extern size_t _dl_dst_count (const char *name) attribute_hidden;
1244
1245/* Substitute DST values. */
1246extern char *_dl_dst_substitute (struct link_map *l, const char *name,
1247 char *result) attribute_hidden;
1248
1249/* Open the shared object NAME, relocate it, and run its initializer if it
1250 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1251 the object is already opened, returns its existing map. */
1252extern void *_dl_open (const char *name, int mode, const void *caller,
1253 Lmid_t nsid, int argc, char *argv[], char *env[])
1254 attribute_hidden;
1255
1256/* Free or queue for freeing scope OLD. If other threads might be
1257 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1258 old scope, OLD can't be freed until no thread is using it. */
1259extern int _dl_scope_free (void *) attribute_hidden;
1260
1261
1262/* Add module to slot information data. If DO_ADD is false, only the
1263 required memory is allocated. Must be called with GL
1264 (dl_load_lock) acquired. If the function has already been called
1265 for the link map L with !do_add, then this function will not raise
1266 an exception, otherwise it is possible that it encounters a memory
1267 allocation failure. */
1268extern void _dl_add_to_slotinfo (struct link_map *l, bool do_add)
1269 attribute_hidden;
1270
1271/* Update slot information data for at least the generation of the
1272 module with the given index. */
1273extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid)
1274 attribute_hidden;
1275
1276/* Look up the module's TLS block as for __tls_get_addr,
1277 but never touch anything. Return null if it's not allocated yet. */
1278extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
1279
1280extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
1281 attribute_hidden;
1282
1283/* Show show of an object. */
1284extern void _dl_show_scope (struct link_map *new, int from)
1285 attribute_hidden;
1286
1287extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr);
1288rtld_hidden_proto (_dl_find_dso_for_object)
1289
1290/* Initialization which is normally done by the dynamic linker. */
1291extern void _dl_non_dynamic_init (void)
1292 attribute_hidden;
1293
1294/* Used by static binaries to check the auxiliary vector. */
1295extern void _dl_aux_init (ElfW(auxv_t) *av)
1296 attribute_hidden;
1297
1298/* Initialize the static TLS space for the link map in all existing
1299 threads. */
1300#if THREAD_GSCOPE_IN_TCB
1301void _dl_init_static_tls (struct link_map *map) attribute_hidden;
1302#endif
1303static inline void
1304dl_init_static_tls (struct link_map *map)
1305{
1306#if THREAD_GSCOPE_IN_TCB
1307 /* The stack list is available to ld.so, so the initialization can
1308 be handled within ld.so directly. */
1309 _dl_init_static_tls (map);
1310#else
1311 GL (dl_init_static_tls) (map);
1312#endif
1313}
1314
1315#ifndef SHARED
1316/* Called before relocating ld.so during static dlopen. This can be
1317 used to partly initialize the dormant ld.so copy in the static
1318 dlopen namespace. */
1319void __rtld_static_init (struct link_map *map) attribute_hidden;
1320#endif
1321
1322/* Return true if the ld.so copy in this namespace is actually active
1323 and working. If false, the dl_open/dlfcn hooks have to be used to
1324 call into the outer dynamic linker (which happens after static
1325 dlopen). */
1326#ifdef SHARED
1327static inline bool
1328rtld_active (void)
1329{
1330 /* The default-initialized variable does not have a non-zero
1331 dl_init_all_dirs member, so this allows us to recognize an
1332 initialized and active ld.so copy. */
1333 return GLRO(dl_init_all_dirs) != NULL;
1334}
1335
1336static inline struct auditstate *
1337link_map_audit_state (struct link_map *l, size_t index)
1338{
1339 if (l == &GL (dl_rtld_map))
1340 /* The auditstate array is stored separately. */
1341 return &GL (dl_rtld_auditstate) [index];
1342 else
1343 {
1344 /* The auditstate array follows the link map in memory. */
1345 struct auditstate *base = (struct auditstate *) (l + 1);
1346 return &base[index];
1347 }
1348}
1349#endif /* SHARED */
1350
1351#if PTHREAD_IN_LIBC && defined SHARED
1352/* Recursive locking implementation for use within the dynamic loader.
1353 Used to define the __rtld_lock_lock_recursive and
1354 __rtld_lock_unlock_recursive via <libc-lock.h>. Initialized to a
1355 no-op dummy implementation early. Similar
1356 to GL (dl_rtld_lock_recursive) and GL (dl_rtld_unlock_recursive)
1357 in !PTHREAD_IN_LIBC builds. */
1358extern int (*___rtld_mutex_lock) (pthread_mutex_t *) attribute_hidden;
1359extern int (*___rtld_mutex_unlock) (pthread_mutex_t *lock) attribute_hidden;
1360
1361/* Called after libc has been loaded, but before RELRO is activated.
1362 Used to initialize the function pointers to the actual
1363 implementations. */
1364void __rtld_mutex_init (void) attribute_hidden;
1365#else /* !PTHREAD_IN_LIBC */
1366static inline void
1367__rtld_mutex_init (void)
1368{
1369 /* The initialization happens later (!PTHREAD_IN_LIBC) or is not
1370 needed at all (!SHARED). */
1371}
1372#endif /* !PTHREAD_IN_LIBC */
1373
1374#if THREAD_GSCOPE_IN_TCB
1375void __thread_gscope_wait (void) attribute_hidden;
1376# define THREAD_GSCOPE_WAIT() __thread_gscope_wait ()
1377#endif
1378
1379__END_DECLS
1380
1381#endif /* ldsodefs.h */
1382