1/* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2022 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 <dl-fixup-attribute.h>
39#include <libc-lock.h>
40#include <hp-timing.h>
41#include <tls.h>
42#include <list_t.h>
43
44__BEGIN_DECLS
45
46#define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
47#define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
48 + DT_EXTRANUM + DT_VALTAGIDX (tag))
49#define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
50 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
51
52/* Type of GNU hash which the machine uses. */
53#ifndef ELF_MACHINE_GNU_HASH_ADDRIDX
54# define ELF_MACHINE_GNU_HASH_ADDRIDX ADDRIDX (DT_GNU_HASH)
55#endif
56
57/* Calculate the index of a symbol in GNU hash. */
58#ifndef ELF_MACHINE_HASH_SYMIDX
59# define ELF_MACHINE_HASH_SYMIDX(map, hasharr) \
60 ((hasharr) - (map)->l_gnu_chain_zero)
61#endif
62
63/* Setup MIPS xhash. Defined only for MIPS. */
64#ifndef ELF_MACHINE_XHASH_SETUP
65# define ELF_MACHINE_XHASH_SETUP(hash32, symbias, map) \
66 ((void) (hash32), (void) (symbias), (void) (map))
67#endif
68
69/* We use this macro to refer to ELF types independent of the native wordsize.
70 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
71#define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
72
73/* Return true if dynamic section in the shared library L should be
74 relocated. */
75
76static inline bool
77dl_relocate_ld (const struct link_map *l)
78{
79 /* Don't relocate dynamic section if it is readonly */
80 return !(l->l_ld_readonly || DL_RO_DYN_SECTION);
81}
82
83/* All references to the value of l_info[DT_PLTGOT],
84 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
85 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
86 have to be accessed via the D_PTR macro. The macro is needed since for
87 most architectures the entry is already relocated - but for some not
88 and we need to relocate at access time. */
89#define D_PTR(map, i) \
90 ((map)->i->d_un.d_ptr + (dl_relocate_ld (map) ? 0 : (map)->l_addr))
91
92/* Result of the lookup functions and how to retrieve the base address. */
93typedef struct link_map *lookup_t;
94#define LOOKUP_VALUE(map) map
95#define LOOKUP_VALUE_ADDRESS(map, set) ((set) || (map) ? (map)->l_addr : 0)
96
97/* Calculate the address of symbol REF using the base address from map MAP,
98 if non-NULL. Don't check for NULL map if MAP_SET is TRUE. */
99#define SYMBOL_ADDRESS(map, ref, map_set) \
100 ((ref) == NULL ? 0 \
101 : (__glibc_unlikely ((ref)->st_shndx == SHN_ABS) ? 0 \
102 : LOOKUP_VALUE_ADDRESS (map, map_set)) + (ref)->st_value)
103
104/* Type of a constructor function, in DT_INIT, DT_INIT_ARRAY,
105 DT_PREINIT_ARRAY. */
106typedef void (*dl_init_t) (int, char **, char **);
107
108/* On some architectures a pointer to a function is not just a pointer
109 to the actual code of the function but rather an architecture
110 specific descriptor. */
111#ifndef ELF_FUNCTION_PTR_IS_SPECIAL
112# define DL_SYMBOL_ADDRESS(map, ref) \
113 (void *) SYMBOL_ADDRESS (map, ref, false)
114# define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
115# define DL_CALL_DT_INIT(map, start, argc, argv, env) \
116 ((dl_init_t) (start)) (argc, argv, env)
117# define DL_CALL_DT_FINI(map, start) ((fini_t) (start)) ()
118#endif
119
120/* On some architectures dladdr can't use st_size of all symbols this way. */
121#define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
122 ((ADDR) >= (L)->l_addr + (SYM)->st_value \
123 && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
124 && (ADDR) == (L)->l_addr + (SYM)->st_value) \
125 || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
126 && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
127
128/* According to the ELF gABI no STV_HIDDEN or STV_INTERNAL symbols are
129 expected to be present in dynamic symbol tables as they should have
130 been either removed or converted to STB_LOCAL binding by the static
131 linker. However some GNU binutils versions produce such symbols in
132 some cases. To prevent such symbols present in a buggy binary from
133 preempting global symbols we filter them out with this predicate. */
134static __always_inline bool
135dl_symbol_visibility_binds_local_p (const ElfW(Sym) *sym)
136{
137 return (ELFW(ST_VISIBILITY) (sym->st_other) == STV_HIDDEN
138 || ELFW(ST_VISIBILITY) (sym->st_other) == STV_INTERNAL);
139}
140
141/* Unmap a loaded object, called by _dl_close (). */
142#ifndef DL_UNMAP_IS_SPECIAL
143# define DL_UNMAP(map) _dl_unmap_segments (map)
144#endif
145
146/* Reloc type classes as returned by elf_machine_type_class().
147 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
148 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
149 satisfied by any symbol in the executable. Some architectures do
150 not support copy relocations. In this case we define the macro to
151 zero so that the code for handling them gets automatically optimized
152 out. ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA means address of protected
153 data defined in the shared library may be external, i.e., due to copy
154 relocation. */
155#define ELF_RTYPE_CLASS_PLT 1
156#ifndef DL_NO_COPY_RELOCS
157# define ELF_RTYPE_CLASS_COPY 2
158#else
159# define ELF_RTYPE_CLASS_COPY 0
160#endif
161/* If DL_EXTERN_PROTECTED_DATA is defined, address of protected data
162 defined in the shared library may be external, i.e., due to copy
163 relocation. */
164#ifdef DL_EXTERN_PROTECTED_DATA
165# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 4
166#else
167# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 0
168#endif
169
170/* ELF uses the PF_x macros to specify the segment permissions, mmap
171 uses PROT_xxx. In most cases the three macros have the values 1, 2,
172 and 3 but not in a matching order. The following macros allows
173 converting from the PF_x values to PROT_xxx values. */
174#define PF_TO_PROT \
175 ((PROT_READ << (PF_R * 4)) \
176 | (PROT_WRITE << (PF_W * 4)) \
177 | (PROT_EXEC << (PF_X * 4)) \
178 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
179 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
180 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
181 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
182
183/* The filename itself, or the main program name, if available. */
184#define DSO_FILENAME(name) ((name)[0] ? (name) \
185 : (rtld_progname ?: "<main program>"))
186
187#define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
188
189/* For the version handling we need an array with only names and their
190 hash values. */
191struct r_found_version
192 {
193 const char *name;
194 ElfW(Word) hash;
195
196 int hidden;
197 const char *filename;
198 };
199
200/* We want to cache information about the searches for shared objects. */
201
202enum r_dir_status { unknown, nonexisting, existing };
203
204struct r_search_path_elem
205 {
206 /* This link is only used in the `all_dirs' member of `r_search_path'. */
207 struct r_search_path_elem *next;
208
209 /* Strings saying where the definition came from. */
210 const char *what;
211 const char *where;
212
213 /* Basename for this search path element. The string must end with
214 a slash character. */
215 const char *dirname;
216 size_t dirnamelen;
217
218 enum r_dir_status status[0];
219 };
220
221struct r_strlenpair
222 {
223 const char *str;
224 size_t len;
225 };
226
227
228/* A data structure for a simple single linked list of strings. */
229struct libname_list
230 {
231 const char *name; /* Name requested (before search). */
232 struct libname_list *next; /* Link to next name for this object. */
233 int dont_free; /* Flag whether this element should be freed
234 if the object is not entirely unloaded. */
235 };
236
237
238/* Bit masks for the objects which valid callers can come from to
239 functions with restricted interface. */
240enum allowmask
241 {
242 allow_libc = 1,
243 allow_libdl = 2,
244 allow_libpthread = 4,
245 allow_ldso = 8
246 };
247
248
249/* DSO sort algorithm to use (check dl-sort-maps.c). */
250enum dso_sort_algorithm
251 {
252 dso_sort_algorithm_original,
253 dso_sort_algorithm_dfs
254 };
255
256struct audit_ifaces
257{
258 void (*activity) (uintptr_t *, unsigned int);
259 char *(*objsearch) (const char *, uintptr_t *, unsigned int);
260 unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
261 void (*preinit) (uintptr_t *);
262 union
263 {
264 uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
265 uintptr_t *, unsigned int *, const char *);
266 uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
267 uintptr_t *, unsigned int *, const char *);
268 };
269 union
270 {
271#ifdef ARCH_PLTENTER_MEMBERS
272 ARCH_PLTENTER_MEMBERS;
273#endif
274 };
275 union
276 {
277#ifdef ARCH_PLTEXIT_MEMBERS
278 ARCH_PLTEXIT_MEMBERS;
279#endif
280 };
281 unsigned int (*objclose) (uintptr_t *);
282
283 struct audit_ifaces *next;
284};
285
286
287/* Test whether given NAME matches any of the names of the given object. */
288extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
289 attribute_hidden;
290
291/* Compute next higher prime number. */
292extern unsigned long int _dl_higher_prime_number (unsigned long int n)
293 attribute_hidden;
294
295/* A stripped down strtoul-like implementation. */
296uint64_t _dl_strtoul (const char *, char **) attribute_hidden;
297
298/* Function used as argument for `_dl_receive_error' function. The
299 arguments are the error code, error string, and the objname the
300 error occurred in. */
301typedef void (*receiver_fct) (int, const char *, const char *);
302
303/* Internal functions of the run-time dynamic linker.
304 These can be accessed if you link again the dynamic linker
305 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
306 but are not normally of interest to user programs.
307
308 The `-ldl' library functions in <dlfcn.h> provide a simple
309 user interface to run-time dynamic linking. */
310
311
312#ifndef SHARED
313# define EXTERN extern
314# define GL(name) _##name
315#else
316# define EXTERN
317# if IS_IN (rtld)
318# define GL(name) _rtld_local._##name
319# else
320# define GL(name) _rtld_global._##name
321# endif
322struct rtld_global
323{
324#endif
325 /* Don't change the order of the following elements. 'dl_loaded'
326 must remain the first element. Forever. */
327
328/* Non-shared code has no support for multiple namespaces. */
329#ifdef SHARED
330# define DL_NNS 16
331#else
332# define DL_NNS 1
333#endif
334 EXTERN struct link_namespaces
335 {
336 /* A pointer to the map for the main map. */
337 struct link_map *_ns_loaded;
338 /* Number of object in the _dl_loaded list. */
339 unsigned int _ns_nloaded;
340 /* Direct pointer to the searchlist of the main object. */
341 struct r_scope_elem *_ns_main_searchlist;
342 /* This is zero at program start to signal that the global scope map is
343 allocated by rtld. Later it keeps the size of the map. It might be
344 reset if in _dl_close if the last global object is removed. */
345 unsigned int _ns_global_scope_alloc;
346
347 /* During dlopen, this is the number of objects that still need to
348 be added to the global scope map. It has to be taken into
349 account when resizing the map, for future map additions after
350 recursive dlopen calls from ELF constructors. */
351 unsigned int _ns_global_scope_pending_adds;
352
353 /* Once libc.so has been loaded into the namespace, this points to
354 its link map. */
355 struct link_map *libc_map;
356
357 /* Search table for unique objects. */
358 struct unique_sym_table
359 {
360 __rtld_lock_define_recursive (, lock)
361 struct unique_sym
362 {
363 uint32_t hashval;
364 const char *name;
365 const ElfW(Sym) *sym;
366 const struct link_map *map;
367 } *entries;
368 size_t size;
369 size_t n_elements;
370 void (*free) (void *);
371 } _ns_unique_sym_table;
372 /* Keep track of changes to each namespace' list. */
373 struct r_debug_extended _ns_debug;
374 } _dl_ns[DL_NNS];
375 /* One higher than index of last used namespace. */
376 EXTERN size_t _dl_nns;
377
378 /* During the program run we must not modify the global data of
379 loaded shared object simultanously in two threads. Therefore we
380 protect `_dl_open' and `_dl_close' in dl-close.c.
381
382 This must be a recursive lock since the initializer function of
383 the loaded object might as well require a call to this function.
384 At this time it is not anymore a problem to modify the tables. */
385 __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
386 /* This lock is used to keep __dl_iterate_phdr from inspecting the
387 list of loaded objects while an object is added to or removed
388 from that list. */
389 __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
390 /* This lock protects global and module specific TLS related data.
391 E.g. it is held in dlopen and dlclose when GL(dl_tls_generation),
392 GL(dl_tls_max_dtv_idx) or GL(dl_tls_dtv_slotinfo_list) are
393 accessed and when TLS related relocations are processed for a
394 module. It was introduced to keep pthread_create accessing TLS
395 state that is being set up. */
396 __rtld_lock_define_recursive (EXTERN, _dl_load_tls_lock)
397
398 /* Incremented whenever something may have been added to dl_loaded. */
399 EXTERN unsigned long long _dl_load_adds;
400
401 /* The object to be initialized first. */
402 EXTERN struct link_map *_dl_initfirst;
403
404 /* Map of shared object to be profiled. */
405 EXTERN struct link_map *_dl_profile_map;
406
407 /* Counters for the number of relocations performed. */
408 EXTERN unsigned long int _dl_num_relocations;
409 EXTERN unsigned long int _dl_num_cache_relocations;
410
411 /* List of search directories. */
412 EXTERN struct r_search_path_elem *_dl_all_dirs;
413
414 /* Structure describing the dynamic linker itself. */
415 EXTERN struct link_map _dl_rtld_map;
416#ifdef SHARED
417 /* Used to store the audit information for the link map of the
418 dynamic loader. */
419 struct auditstate _dl_rtld_auditstate[DL_NNS];
420#endif
421
422#if !PTHREAD_IN_LIBC && defined SHARED \
423 && defined __rtld_lock_default_lock_recursive
424 EXTERN void (*_dl_rtld_lock_recursive) (void *);
425 EXTERN void (*_dl_rtld_unlock_recursive) (void *);
426#endif
427
428 /* Get architecture specific definitions. */
429#define PROCINFO_DECL
430#ifndef PROCINFO_CLASS
431# define PROCINFO_CLASS EXTERN
432#endif
433#include <dl-procruntime.c>
434
435#if !PTHREAD_IN_LIBC
436 /* If loading a shared object requires that we make the stack executable
437 when it was not, we do it by calling this function.
438 It returns an errno code or zero on success. */
439 EXTERN int (*_dl_make_stack_executable_hook) (void **);
440#endif
441
442 /* Prevailing state of the stack, PF_X indicating it's executable. */
443 EXTERN ElfW(Word) _dl_stack_flags;
444
445 /* Flag signalling whether there are gaps in the module ID allocation. */
446 EXTERN bool _dl_tls_dtv_gaps;
447 /* Highest dtv index currently needed. */
448 EXTERN size_t _dl_tls_max_dtv_idx;
449 /* Information about the dtv slots. */
450 EXTERN struct dtv_slotinfo_list
451 {
452 size_t len;
453 struct dtv_slotinfo_list *next;
454 struct dtv_slotinfo
455 {
456 size_t gen;
457 struct link_map *map;
458 } slotinfo[];
459 } *_dl_tls_dtv_slotinfo_list;
460 /* Number of modules in the static TLS block. */
461 EXTERN size_t _dl_tls_static_nelem;
462 /* Size actually allocated in the static TLS block. */
463 EXTERN size_t _dl_tls_static_used;
464 /* Remaining amount of static TLS that may be used for optimizing
465 dynamic TLS access (e.g. with TLSDESC). */
466 EXTERN size_t _dl_tls_static_optional;
467
468/* Number of additional entries in the slotinfo array of each slotinfo
469 list element. A large number makes it almost certain take we never
470 have to iterate beyond the first element in the slotinfo list. */
471#define TLS_SLOTINFO_SURPLUS (62)
472
473/* Number of additional slots in the dtv allocated. */
474#define DTV_SURPLUS (14)
475
476 /* Initial dtv of the main thread, not allocated with normal malloc. */
477 EXTERN void *_dl_initial_dtv;
478 /* Generation counter for the dtv. */
479 EXTERN size_t _dl_tls_generation;
480
481#if !PTHREAD_IN_LIBC
482 EXTERN void (*_dl_init_static_tls) (struct link_map *);
483#endif
484
485 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
486 EXTERN struct dl_scope_free_list
487 {
488 size_t count;
489 void *list[50];
490 } *_dl_scope_free_list;
491#if PTHREAD_IN_LIBC
492 /* List of active thread stacks, with memory managed by glibc. */
493 EXTERN list_t _dl_stack_used;
494
495 /* List of thread stacks that were allocated by the application. */
496 EXTERN list_t _dl_stack_user;
497
498 /* List of queued thread stacks. */
499 EXTERN list_t _dl_stack_cache;
500
501 /* Total size of all stacks in the cache (sum over stackblock_size). */
502 EXTERN size_t _dl_stack_cache_actsize;
503
504 /* We need to record what list operations we are going to do so
505 that, in case of an asynchronous interruption due to a fork()
506 call, we can correct for the work. */
507 EXTERN uintptr_t _dl_in_flight_stack;
508
509 /* Mutex protecting the stack lists. */
510 EXTERN int _dl_stack_cache_lock;
511#else
512 /* The total number of thread IDs currently in use, or on the list of
513 available thread IDs. */
514 EXTERN int _dl_pthread_num_threads;
515
516 /* Array of __pthread structures and its lock. */
517 EXTERN struct __pthread **_dl_pthread_threads;
518 __libc_rwlock_define (EXTERN, _dl_pthread_threads_lock)
519#endif
520#ifdef SHARED
521};
522# define __rtld_global_attribute__
523# if IS_IN (rtld)
524# ifdef HAVE_SDATA_SECTION
525# define __rtld_local_attribute__ \
526 __attribute__ ((visibility ("hidden"), section (".sdata")))
527# undef __rtld_global_attribute__
528# define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
529# else
530# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
531# endif
532extern struct rtld_global _rtld_local __rtld_local_attribute__;
533# undef __rtld_local_attribute__
534# endif
535extern struct rtld_global _rtld_global __rtld_global_attribute__;
536# undef __rtld_global_attribute__
537#endif
538
539#ifndef SHARED
540# define GLRO(name) _##name
541#else
542# if IS_IN (rtld)
543# define GLRO(name) _rtld_local_ro._##name
544# else
545# define GLRO(name) _rtld_global_ro._##name
546# endif
547struct rtld_global_ro
548{
549#endif
550
551 /* If nonzero the appropriate debug information is printed. */
552 EXTERN int _dl_debug_mask;
553#define DL_DEBUG_LIBS (1 << 0)
554#define DL_DEBUG_IMPCALLS (1 << 1)
555#define DL_DEBUG_BINDINGS (1 << 2)
556#define DL_DEBUG_SYMBOLS (1 << 3)
557#define DL_DEBUG_VERSIONS (1 << 4)
558#define DL_DEBUG_RELOC (1 << 5)
559#define DL_DEBUG_FILES (1 << 6)
560#define DL_DEBUG_STATISTICS (1 << 7)
561#define DL_DEBUG_UNUSED (1 << 8)
562#define DL_DEBUG_SCOPES (1 << 9)
563/* These two are used only internally. */
564#define DL_DEBUG_HELP (1 << 10)
565#define DL_DEBUG_PRELINK (1 << 11)
566
567 /* OS version. */
568 EXTERN unsigned int _dl_osversion;
569 /* Platform name. */
570 EXTERN const char *_dl_platform;
571 EXTERN size_t _dl_platformlen;
572
573 /* Cached value of `getpagesize ()'. */
574 EXTERN size_t _dl_pagesize;
575
576 /* Cached value of `sysconf (_SC_MINSIGSTKSZ)'. */
577 EXTERN size_t _dl_minsigstacksize;
578
579 /* Do we read from ld.so.cache? */
580 EXTERN int _dl_inhibit_cache;
581
582 /* Copy of the content of `_dl_main_searchlist' at startup time. */
583 EXTERN struct r_scope_elem _dl_initial_searchlist;
584
585 /* CLK_TCK as reported by the kernel. */
586 EXTERN int _dl_clktck;
587
588 /* If nonzero print warnings messages. */
589 EXTERN int _dl_verbose;
590
591 /* File descriptor to write debug messages to. */
592 EXTERN int _dl_debug_fd;
593
594 /* Do we do lazy relocations? */
595 EXTERN int _dl_lazy;
596
597 /* Nonzero if runtime lookups should not update the .got/.plt. */
598 EXTERN int _dl_bind_not;
599
600 /* Nonzero if references should be treated as weak during runtime
601 linking. */
602 EXTERN int _dl_dynamic_weak;
603
604 /* Default floating-point control word. */
605 EXTERN fpu_control_t _dl_fpu_control;
606
607 /* Expected cache ID. */
608 EXTERN int _dl_correct_cache_id;
609
610 /* Mask for hardware capabilities that are available. */
611 EXTERN uint64_t _dl_hwcap;
612
613#if !HAVE_TUNABLES
614 /* Mask for important hardware capabilities we honour. */
615 EXTERN uint64_t _dl_hwcap_mask;
616#endif
617
618#ifdef HAVE_AUX_VECTOR
619 /* Pointer to the auxv list supplied to the program at startup. */
620 EXTERN ElfW(auxv_t) *_dl_auxv;
621#endif
622
623 /* Get architecture specific definitions. */
624#include <dl-procinfo.c>
625
626 /* Names of shared object for which the RPATH should be ignored. */
627 EXTERN const char *_dl_inhibit_rpath;
628
629 /* Location of the binary. */
630 EXTERN const char *_dl_origin_path;
631
632 /* -1 if the dynamic linker should honor library load bias,
633 0 if not, -2 use the default (honor biases for normal
634 binaries, don't honor for PIEs). */
635 EXTERN ElfW(Addr) _dl_use_load_bias;
636
637 /* Size of the static TLS block. */
638 EXTERN size_t _dl_tls_static_size;
639
640 /* Alignment requirement of the static TLS block. */
641 EXTERN size_t _dl_tls_static_align;
642
643 /* Size of surplus space in the static TLS area for dynamically
644 loaded modules with IE-model TLS or for TLSDESC optimization.
645 See comments in elf/dl-tls.c where it is initialized. */
646 EXTERN size_t _dl_tls_static_surplus;
647
648 /* Name of the shared object to be profiled (if any). */
649 EXTERN const char *_dl_profile;
650 /* Filename of the output file. */
651 EXTERN const char *_dl_profile_output;
652 /* Name of the object we want to trace the prelinking. */
653 EXTERN const char *_dl_trace_prelink;
654 /* Map of shared object to be prelink traced. */
655 EXTERN struct link_map *_dl_trace_prelink_map;
656
657 /* All search directories defined at startup. This is assigned a
658 non-NULL pointer by the ld.so startup code (after initialization
659 to NULL), so this can also serve as an indicator whether a copy
660 of ld.so is initialized and active. See the rtld_active function
661 below. */
662 EXTERN struct r_search_path_elem *_dl_init_all_dirs;
663
664#ifdef NEED_DL_SYSINFO
665 /* Syscall handling improvements. This is very specific to x86. */
666 EXTERN uintptr_t _dl_sysinfo;
667#endif
668
669#ifdef NEED_DL_SYSINFO_DSO
670 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
671 This points to its ELF header. */
672 EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
673
674 /* At startup time we set up the normal DSO data structure for it,
675 and this points to it. */
676 EXTERN struct link_map *_dl_sysinfo_map;
677
678# define PROCINFO_DECL
679# ifndef PROCINFO_CLASS
680# define PROCINFO_CLASS EXTERN
681# endif
682# include <dl-vdso-setup.c>
683#endif
684
685 /* Mask for more hardware capabilities that are available on some
686 platforms. */
687 EXTERN uint64_t _dl_hwcap2;
688
689 EXTERN enum dso_sort_algorithm _dl_dso_sort_algo;
690
691#ifdef SHARED
692 /* We add a function table to _rtld_global which is then used to
693 call the function instead of going through the PLT. The result
694 is that we can avoid exporting the functions and we do not jump
695 PLT relocations in libc.so. */
696 void (*_dl_debug_printf) (const char *, ...)
697 __attribute__ ((__format__ (__printf__, 1, 2)));
698 void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
699 lookup_t (*_dl_lookup_symbol_x) (const char *, struct link_map *,
700 const ElfW(Sym) **, struct r_scope_elem *[],
701 const struct r_found_version *, int, int,
702 struct link_map *);
703 void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
704 Lmid_t nsid, int argc, char *argv[], char *env[]);
705 void (*_dl_close) (void *map);
706 /* libdl in a secondary namespace (after dlopen) must use
707 _dl_catch_error from the main namespace, so it has to be
708 exported in some way. */
709 int (*_dl_catch_error) (const char **objname, const char **errstring,
710 bool *mallocedp, void (*operate) (void *),
711 void *args);
712 /* libdl in a secondary namespace must use free from the base
713 namespace. */
714 void (*_dl_error_free) (void *);
715 void *(*_dl_tls_get_addr_soft) (struct link_map *);
716
717 /* Called from __libc_shared to deallocate malloc'ed memory. */
718 void (*_dl_libc_freeres) (void);
719
720 /* Implementation of _dl_find_object. The public entry point is in
721 libc, and this is patched by __rtld_static_init to support static
722 dlopen. */
723 int (*_dl_find_object) (void *, struct dl_find_object *);
724
725#ifdef HAVE_DL_DISCOVER_OSVERSION
726 int (*_dl_discover_osversion) (void);
727#endif
728
729 /* Dynamic linker operations used after static dlopen. */
730 const struct dlfcn_hook *_dl_dlfcn_hook;
731
732 /* List of auditing interfaces. */
733 struct audit_ifaces *_dl_audit;
734 unsigned int _dl_naudit;
735};
736# define __rtld_global_attribute__
737# if IS_IN (rtld)
738# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
739extern struct rtld_global_ro _rtld_local_ro
740 attribute_relro __rtld_local_attribute__;
741extern struct rtld_global_ro _rtld_global_ro
742 attribute_relro __rtld_global_attribute__;
743# undef __rtld_local_attribute__
744# else
745/* We cheat a bit here. We declare the variable as as const even
746 though it is at startup. */
747extern const struct rtld_global_ro _rtld_global_ro
748 attribute_relro __rtld_global_attribute__;
749# endif
750# undef __rtld_global_attribute__
751#endif
752#undef EXTERN
753
754#ifndef SHARED
755/* dl-support.c defines these and initializes them early on. */
756extern const ElfW(Phdr) *_dl_phdr;
757extern size_t _dl_phnum;
758#endif
759
760#if PTHREAD_IN_LIBC
761/* This function changes the permissions of all stacks (not just those
762 of the main stack). */
763int _dl_make_stacks_executable (void **stack_endp) attribute_hidden;
764#else
765/* This is the initial value of GL(dl_make_stack_executable_hook).
766 A threads library can change it. The ld.so implementation changes
767 the permissions of the main stack only. */
768extern int _dl_make_stack_executable (void **stack_endp);
769rtld_hidden_proto (_dl_make_stack_executable)
770#endif
771
772/* Variable pointing to the end of the stack (or close to it). This value
773 must be constant over the runtime of the application. Some programs
774 might use the variable which results in copy relocations on some
775 platforms. But this does not matter, ld.so can always use the local
776 copy. */
777extern void *__libc_stack_end
778#ifndef LIBC_STACK_END_NOT_RELRO
779 attribute_relro
780#endif
781 ;
782rtld_hidden_proto (__libc_stack_end)
783
784/* Parameters passed to the dynamic linker. */
785extern int _dl_argc attribute_hidden attribute_relro;
786extern char **_dl_argv
787#ifndef DL_ARGV_NOT_RELRO
788 attribute_relro
789#endif
790 ;
791rtld_hidden_proto (_dl_argv)
792#if IS_IN (rtld)
793extern unsigned int _dl_skip_args attribute_hidden
794# ifndef DL_ARGV_NOT_RELRO
795 attribute_relro
796# endif
797 ;
798extern unsigned int _dl_skip_args_internal attribute_hidden
799# ifndef DL_ARGV_NOT_RELRO
800 attribute_relro
801# endif
802 ;
803#endif
804#define rtld_progname _dl_argv[0]
805
806/* Flag set at startup and cleared when the last initializer has run. */
807extern int _dl_starting_up;
808weak_extern (_dl_starting_up)
809rtld_hidden_proto (_dl_starting_up)
810
811/* Random data provided by the kernel. */
812extern void *_dl_random attribute_hidden attribute_relro;
813
814/* Write message on the debug file descriptor. The parameters are
815 interpreted as for a `printf' call. All the lines start with a
816 tag showing the PID. */
817extern void _dl_debug_printf (const char *fmt, ...)
818 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
819
820/* Write message on the debug file descriptor. The parameters are
821 interpreted as for a `printf' call. All the lines buf the first
822 start with a tag showing the PID. */
823extern void _dl_debug_printf_c (const char *fmt, ...)
824 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
825
826
827/* Write a message on the specified descriptor FD. The parameters are
828 interpreted as for a `printf' call. */
829#if IS_IN (rtld) || !defined (SHARED)
830extern void _dl_dprintf (int fd, const char *fmt, ...)
831 __attribute__ ((__format__ (__printf__, 2, 3)))
832 attribute_hidden;
833#else
834__attribute__ ((always_inline, __format__ (__printf__, 2, 3)))
835static inline void
836_dl_dprintf (int fd, const char *fmt, ...)
837{
838 /* Use local declaration to avoid includign <stdio.h>. */
839 extern int __dprintf(int fd, const char *format, ...) attribute_hidden;
840 __dprintf (fd, fmt, __builtin_va_arg_pack ());
841}
842#endif
843
844/* Write LENGTH bytes at BUFFER to FD, like write. Returns the number
845 of bytes written on success, or a negative error constant on
846 failure. */
847ssize_t _dl_write (int fd, const void *buffer, size_t length)
848 attribute_hidden;
849
850/* Write a message on the specified descriptor standard output. The
851 parameters are interpreted as for a `printf' call. */
852void _dl_printf (const char *fmt, ...)
853 attribute_hidden __attribute__ ((__format__ (__printf__, 1, 2)));
854
855/* Write a message on the specified descriptor standard error. The
856 parameters are interpreted as for a `printf' call. */
857void _dl_error_printf (const char *fmt, ...)
858 attribute_hidden __attribute__ ((__format__ (__printf__, 1, 2)));
859
860/* Write a message on the specified descriptor standard error and exit
861 the program. The parameters are interpreted as for a `printf' call. */
862void _dl_fatal_printf (const char *fmt, ...)
863 __attribute__ ((__format__ (__printf__, 1, 2), __noreturn__));
864rtld_hidden_proto (_dl_fatal_printf)
865
866/* An exception raised by the _dl_signal_error function family and
867 caught by _dl_catch_error function family. Exceptions themselves
868 are copied as part of the raise operation, but the strings are
869 not. */
870struct dl_exception
871{
872 const char *objname;
873 const char *errstring;
874
875 /* This buffer typically stores both objname and errstring
876 above. */
877 char *message_buffer;
878};
879
880/* Creates a new exception. This calls malloc; if allocation fails,
881 dummy values are inserted. OBJECT is the name of the problematical
882 shared object, or null if its a general problem. ERRSTRING is a
883 string describing the specific problem. */
884void _dl_exception_create (struct dl_exception *, const char *object,
885 const char *errstring)
886 __attribute__ ((nonnull (1, 3)));
887rtld_hidden_proto (_dl_exception_create)
888
889/* Used internally to implement dlerror message freeing. See
890 include/dlfcn.h and dlfcn/dlerror.c. */
891void _dl_error_free (void *ptr) attribute_hidden;
892
893/* Like _dl_exception_create, but create errstring from a format
894 string FMT. Currently, only "%s" and "%%" are supported as format
895 directives. */
896void _dl_exception_create_format (struct dl_exception *, const char *objname,
897 const char *fmt, ...)
898 __attribute__ ((nonnull (1, 3), format (printf, 3, 4)));
899rtld_hidden_proto (_dl_exception_create_format)
900
901/* Deallocate the exception, freeing allocated buffers (if
902 possible). */
903void _dl_exception_free (struct dl_exception *)
904 __attribute__ ((nonnull (1)));
905rtld_hidden_proto (_dl_exception_free)
906
907/* This function is called by all the internal dynamic linker
908 functions when they encounter an error. ERRCODE is either an
909 `errno' code or zero; it specifies the return value of
910 _dl_catch_error. OCCASION is included in the error message if the
911 process is terminated immediately. */
912void _dl_signal_exception (int errcode, struct dl_exception *,
913 const char *occasion)
914 __attribute__ ((__noreturn__));
915libc_hidden_proto (_dl_signal_exception)
916
917/* Like _dl_signal_exception, but creates the exception first. */
918extern void _dl_signal_error (int errcode, const char *object,
919 const char *occasion, const char *errstring)
920 __attribute__ ((__noreturn__));
921libc_hidden_proto (_dl_signal_error)
922
923/* Like _dl_signal_exception, but may return when called in the
924 context of _dl_receive_error. This is only used during ld.so
925 bootstrap. In static and profiled builds, this is equivalent to
926 _dl_signal_exception. */
927#if IS_IN (rtld)
928extern void _dl_signal_cexception (int errcode, struct dl_exception *,
929 const char *occasion) attribute_hidden;
930#else
931__attribute__ ((always_inline))
932static inline void
933_dl_signal_cexception (int errcode, struct dl_exception *exception,
934 const char *occasion)
935{
936 _dl_signal_exception (errcode, exception, occasion);
937}
938#endif
939
940/* See _dl_signal_cexception above. */
941#if IS_IN (rtld)
942extern void _dl_signal_cerror (int errcode, const char *object,
943 const char *occasion, const char *errstring)
944 attribute_hidden;
945#else
946__attribute__ ((always_inline))
947static inline void
948_dl_signal_cerror (int errcode, const char *object,
949 const char *occasion, const char *errstring)
950{
951 _dl_signal_error (errcode, object, occasion, errstring);
952}
953#endif
954
955/* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
956 `_dl_catch_error' the operation is resumed after the OPERATE
957 function returns.
958 ARGS is passed as argument to OPERATE. */
959extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
960 void *args) attribute_hidden;
961
962/* Call OPERATE, catching errors from `_dl_signal_error' and related
963 functions. If there is no error, *ERRSTRING is set to null. If
964 there is an error, *ERRSTRING is set to a string constructed from
965 the strings passed to _dl_signal_error, and the error code passed
966 is the return value and *OBJNAME is set to the object name which
967 experienced the problems. ERRSTRING if nonzero points to a
968 malloc'ed string which the caller has to free after use. ARGS is
969 passed as argument to OPERATE. MALLOCEDP is set to true only if
970 the returned string is allocated using the libc's malloc. */
971extern int _dl_catch_error (const char **objname, const char **errstring,
972 bool *mallocedp, void (*operate) (void *),
973 void *args);
974libc_hidden_proto (_dl_catch_error)
975
976/* Used for initializing GLRO (_dl_catch_error). */
977extern __typeof__ (_dl_catch_error) _rtld_catch_error attribute_hidden;
978
979/* Call OPERATE (ARGS). If no error occurs, set *EXCEPTION to zero.
980 Otherwise, store a copy of the raised exception in *EXCEPTION,
981 which has to be freed by _dl_exception_free. As a special case, if
982 EXCEPTION is null, call OPERATE (ARGS) with exception handling
983 disabled (so that exceptions are fatal). */
984int _dl_catch_exception (struct dl_exception *exception,
985 void (*operate) (void *), void *args);
986libc_hidden_proto (_dl_catch_exception)
987
988/* Open the shared object NAME and map in its segments.
989 LOADER's DT_RPATH is used in searching for NAME.
990 If the object is already opened, returns its existing map. */
991extern struct link_map *_dl_map_object (struct link_map *loader,
992 const char *name,
993 int type, int trace_mode, int mode,
994 Lmid_t nsid) attribute_hidden;
995
996/* Call _dl_map_object on the dependencies of MAP, and set up
997 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
998 loaded objects that will be inserted into MAP->l_searchlist after MAP
999 but before its dependencies. */
1000extern void _dl_map_object_deps (struct link_map *map,
1001 struct link_map **preloads,
1002 unsigned int npreloads, int trace_mode,
1003 int open_mode)
1004 attribute_hidden;
1005
1006/* Cache the locations of MAP's hash table. */
1007extern void _dl_setup_hash (struct link_map *map) attribute_hidden;
1008
1009
1010/* Collect the directories in the search path for LOADER's dependencies.
1011 The data structure is defined in <dlfcn.h>. If COUNTING is true,
1012 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
1013 by a previous call with COUNTING set, and SI must point to SI->dls_size
1014 bytes to be used in filling in the result. */
1015extern void _dl_rtld_di_serinfo (struct link_map *loader,
1016 Dl_serinfo *si, bool counting);
1017
1018/* Process PT_GNU_PROPERTY program header PH in module L after
1019 PT_LOAD segments are mapped from file FD. */
1020void _dl_process_pt_gnu_property (struct link_map *l, int fd,
1021 const ElfW(Phdr) *ph);
1022
1023
1024/* Search loaded objects' symbol tables for a definition of the symbol
1025 referred to by UNDEF. *SYM is the symbol table entry containing the
1026 reference; it is replaced with the defining symbol, and the base load
1027 address of the defining object is returned. SYMBOL_SCOPE is a
1028 null-terminated list of object scopes to search; each object's
1029 l_searchlist (i.e. the segment of the dependency tree starting at that
1030 object) is searched in turn. REFERENCE_NAME should name the object
1031 containing the reference; it is used in error messages.
1032 TYPE_CLASS describes the type of symbol we are looking for. */
1033enum
1034 {
1035 /* If necessary add dependency between user and provider object. */
1036 DL_LOOKUP_ADD_DEPENDENCY = 1,
1037 /* Return most recent version instead of default version for
1038 unversioned lookup. */
1039 DL_LOOKUP_RETURN_NEWEST = 2,
1040 /* Set if dl_lookup* called with GSCOPE lock held. */
1041 DL_LOOKUP_GSCOPE_LOCK = 4,
1042 /* Set if dl_lookup is called for non-lazy relocation processing
1043 from _dl_relocate_object in elf/dl-reloc.c. */
1044 DL_LOOKUP_FOR_RELOCATE = 8,
1045 };
1046
1047/* Lookup versioned symbol. */
1048extern lookup_t _dl_lookup_symbol_x (const char *undef,
1049 struct link_map *undef_map,
1050 const ElfW(Sym) **sym,
1051 struct r_scope_elem *symbol_scope[],
1052 const struct r_found_version *version,
1053 int type_class, int flags,
1054 struct link_map *skip_map)
1055 attribute_hidden;
1056
1057
1058/* Restricted version of _dl_lookup_symbol_x. Searches MAP (and only
1059 MAP) for the symbol UNDEF_NAME, with GNU hash NEW_HASH (computed
1060 with dl_new_hash), symbol version VERSION, and symbol version hash
1061 VERSION_HASH (computed with _dl_elf_hash). Returns a pointer to
1062 the symbol table entry in MAP on success, or NULL on failure. MAP
1063 must have symbol versioning information, or otherwise the result is
1064 undefined. */
1065const ElfW(Sym) *_dl_lookup_direct (struct link_map *map,
1066 const char *undef_name,
1067 uint32_t new_hash,
1068 const char *version,
1069 uint32_t version_hash) attribute_hidden;
1070
1071/* Add the new link_map NEW to the end of the namespace list. */
1072extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
1073 attribute_hidden;
1074
1075/* Allocate a `struct link_map' for a new object being loaded. */
1076extern struct link_map *_dl_new_object (char *realname, const char *libname,
1077 int type, struct link_map *loader,
1078 int mode, Lmid_t nsid)
1079 attribute_hidden;
1080
1081/* Relocate the given object (if it hasn't already been).
1082 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
1083 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
1084extern void _dl_relocate_object (struct link_map *map,
1085 struct r_scope_elem *scope[],
1086 int reloc_mode, int consider_profiling)
1087 attribute_hidden;
1088
1089/* Protect PT_GNU_RELRO area. */
1090extern void _dl_protect_relro (struct link_map *map) attribute_hidden;
1091
1092/* Call _dl_signal_error with a message about an unhandled reloc type.
1093 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
1094 PLT is nonzero if this was a PLT reloc; it just affects the message. */
1095extern void _dl_reloc_bad_type (struct link_map *map,
1096 unsigned int type, int plt)
1097 attribute_hidden __attribute__ ((__noreturn__));
1098
1099/* Resolve conflicts if prelinking. */
1100extern void _dl_resolve_conflicts (struct link_map *l,
1101 ElfW(Rela) *conflict,
1102 ElfW(Rela) *conflictend)
1103 attribute_hidden;
1104
1105/* Check the version dependencies of all objects available through
1106 MAP. If VERBOSE print some more diagnostics. */
1107extern int _dl_check_all_versions (struct link_map *map, int verbose,
1108 int trace_mode) attribute_hidden;
1109
1110/* Check the version dependencies for MAP. If VERBOSE print some more
1111 diagnostics. */
1112extern int _dl_check_map_versions (struct link_map *map, int verbose,
1113 int trace_mode) attribute_hidden;
1114
1115/* Initialize the object in SCOPE by calling the constructors with
1116 ARGC, ARGV, and ENV as the parameters. */
1117extern void _dl_init (struct link_map *main_map, int argc, char **argv,
1118 char **env) attribute_hidden;
1119
1120/* Call the finalizer functions of all shared objects whose
1121 initializer functions have completed. */
1122extern void _dl_fini (void) attribute_hidden;
1123
1124/* Sort array MAPS according to dependencies of the contained objects. */
1125extern void _dl_sort_maps (struct link_map **maps, unsigned int nmaps,
1126 unsigned int skip, bool for_fini) attribute_hidden;
1127
1128/* The dynamic linker calls this function before and having changing
1129 any shared object mappings. The `r_state' member of `struct r_debug'
1130 says what change is taking place. This function's address is
1131 the value of the `r_brk' member. */
1132extern void _dl_debug_state (void);
1133rtld_hidden_proto (_dl_debug_state)
1134
1135/* Initialize `struct r_debug_extended' for the namespace NS. LDBASE
1136 is the run-time load address of the dynamic linker, to be put in the
1137 `r_ldbase' member. Return the address of the structure. */
1138extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
1139 attribute_hidden;
1140
1141/* Update the `r_map' member and return the address of `struct r_debug'
1142 of the namespace NS. */
1143extern struct r_debug *_dl_debug_update (Lmid_t ns) attribute_hidden;
1144
1145/* Initialize the basic data structure for the search paths. SOURCE
1146 is either "LD_LIBRARY_PATH" or "--library-path".
1147 GLIBC_HWCAPS_PREPEND adds additional glibc-hwcaps subdirectories to
1148 search. GLIBC_HWCAPS_MASK is used to filter the built-in
1149 subdirectories if not NULL. */
1150extern void _dl_init_paths (const char *library_path, const char *source,
1151 const char *glibc_hwcaps_prepend,
1152 const char *glibc_hwcaps_mask)
1153 attribute_hidden;
1154
1155/* Gather the information needed to install the profiling tables and start
1156 the timers. */
1157extern void _dl_start_profile (void) attribute_hidden;
1158
1159/* The actual functions used to keep book on the calls. */
1160extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
1161rtld_hidden_proto (_dl_mcount)
1162
1163/* This function is simply a wrapper around the _dl_mcount function
1164 which does not require a FROMPC parameter since this is the
1165 calling function. */
1166extern void _dl_mcount_wrapper (void *selfpc);
1167
1168/* Show the members of the auxiliary array passed up from the kernel. */
1169extern void _dl_show_auxv (void) attribute_hidden;
1170
1171/* Return all environment variables starting with `LD_', one after the
1172 other. */
1173extern char *_dl_next_ld_env_entry (char ***position) attribute_hidden;
1174
1175/* Return an array with the names of the important hardware
1176 capabilities. PREPEND is a colon-separated list of glibc-hwcaps
1177 directories to search first. MASK is a colon-separated list used
1178 to filter the built-in glibc-hwcaps subdirectories. The length of
1179 the array is written to *SZ, and the maximum of all strings length
1180 is written to *MAX_CAPSTRLEN. */
1181const struct r_strlenpair *_dl_important_hwcaps (const char *prepend,
1182 const char *mask,
1183 size_t *sz,
1184 size_t *max_capstrlen)
1185 attribute_hidden;
1186
1187/* Look up NAME in ld.so.cache and return the file name stored there,
1188 or null if none is found. Caller must free returned string. */
1189extern char *_dl_load_cache_lookup (const char *name) attribute_hidden;
1190
1191/* If the system does not support MAP_COPY we cannot leave the file open
1192 all the time since this would create problems when the file is replaced.
1193 Therefore we provide this function to close the file and open it again
1194 once needed. */
1195extern void _dl_unload_cache (void) attribute_hidden;
1196
1197/* System-dependent function to read a file's whole contents in the
1198 most convenient manner available. *SIZEP gets the size of the
1199 file. On error MAP_FAILED is returned. */
1200extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
1201 int prot) attribute_hidden;
1202
1203/* System-specific function to do initial startup for the dynamic linker.
1204 After this, file access calls and getenv must work. This is responsible
1205 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
1206 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
1207extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
1208 void (*dl_main) (const ElfW(Phdr) *phdr,
1209 ElfW(Word) phnum,
1210 ElfW(Addr) *user_entry,
1211 ElfW(auxv_t) *auxv))
1212 attribute_hidden;
1213
1214extern void _dl_sysdep_start_cleanup (void) attribute_hidden;
1215
1216
1217/* Determine next available module ID and set the L l_tls_modid. */
1218extern void _dl_assign_tls_modid (struct link_map *l) attribute_hidden;
1219
1220/* Count the modules with TLS segments. */
1221extern size_t _dl_count_modids (void) attribute_hidden;
1222
1223/* Calculate offset of the TLS blocks in the static TLS block. */
1224extern void _dl_determine_tlsoffset (void) attribute_hidden;
1225
1226/* Calculate the size of the static TLS surplus, when the given
1227 number of audit modules are loaded. */
1228void _dl_tls_static_surplus_init (size_t naudit) attribute_hidden;
1229
1230/* This function is called very early from dl_main to set up TLS and
1231 other thread-related data structures. */
1232void __tls_pre_init_tp (void) attribute_hidden;
1233
1234/* This function is called after processor-specific initialization of
1235 the TCB and thread pointer via TLS_INIT_TP, to complete very early
1236 initialization of the thread library. */
1237void __tls_init_tp (void) attribute_hidden;
1238
1239#ifndef SHARED
1240/* Set up the TCB for statically linked applications. This is called
1241 early during startup because we always use TLS (for errno and the
1242 stack protector, among other things). */
1243void __libc_setup_tls (void);
1244
1245# if ENABLE_STATIC_PIE
1246/* Relocate static executable with PIE. */
1247extern void _dl_relocate_static_pie (void) attribute_hidden;
1248
1249/* Get a pointer to _dl_main_map. */
1250extern struct link_map * _dl_get_dl_main_map (void)
1251 __attribute__ ((visibility ("hidden")));
1252# else
1253# define _dl_relocate_static_pie()
1254# endif
1255#endif
1256
1257/* Initialize the DSO sort algorithm to use. */
1258#if !HAVE_TUNABLES
1259static inline void
1260__always_inline
1261_dl_sort_maps_init (void)
1262{
1263 /* This is optimized out if tunables are not enabled. */
1264}
1265#else
1266extern void _dl_sort_maps_init (void) attribute_hidden;
1267#endif
1268
1269/* Initialization of libpthread for statically linked applications.
1270 If libpthread is not linked in, this is an empty function. */
1271void __pthread_initialize_minimal (void) weak_function;
1272
1273/* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
1274extern void *_dl_allocate_tls (void *mem);
1275rtld_hidden_proto (_dl_allocate_tls)
1276
1277/* Get size and alignment requirements of the static TLS block. */
1278extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp);
1279
1280extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
1281
1282/* These are internal entry points to the two halves of _dl_allocate_tls,
1283 only used within rtld.c itself at startup time. */
1284extern void *_dl_allocate_tls_storage (void) attribute_hidden;
1285extern void *_dl_allocate_tls_init (void *, bool);
1286rtld_hidden_proto (_dl_allocate_tls_init)
1287
1288/* Deallocate memory allocated with _dl_allocate_tls. */
1289extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb);
1290rtld_hidden_proto (_dl_deallocate_tls)
1291
1292extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
1293
1294/* Find origin of the executable. */
1295extern const char *_dl_get_origin (void) attribute_hidden;
1296
1297/* Count DSTs. */
1298extern size_t _dl_dst_count (const char *name) attribute_hidden;
1299
1300/* Substitute DST values. */
1301extern char *_dl_dst_substitute (struct link_map *l, const char *name,
1302 char *result) attribute_hidden;
1303
1304/* Open the shared object NAME, relocate it, and run its initializer if it
1305 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1306 the object is already opened, returns its existing map. */
1307extern void *_dl_open (const char *name, int mode, const void *caller,
1308 Lmid_t nsid, int argc, char *argv[], char *env[])
1309 attribute_hidden;
1310
1311/* Free or queue for freeing scope OLD. If other threads might be
1312 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1313 old scope, OLD can't be freed until no thread is using it. */
1314extern int _dl_scope_free (void *) attribute_hidden;
1315
1316
1317/* Add module to slot information data. If DO_ADD is false, only the
1318 required memory is allocated. Must be called with GL
1319 (dl_load_tls_lock) acquired. If the function has already been called
1320 for the link map L with !do_add, then this function will not raise
1321 an exception, otherwise it is possible that it encounters a memory
1322 allocation failure. */
1323extern void _dl_add_to_slotinfo (struct link_map *l, bool do_add)
1324 attribute_hidden;
1325
1326/* Update slot information data for at least the generation of the
1327 module with the given index. */
1328extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid)
1329 attribute_hidden;
1330
1331/* Look up the module's TLS block as for __tls_get_addr,
1332 but never touch anything. Return null if it's not allocated yet. */
1333extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
1334
1335extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
1336 attribute_hidden;
1337
1338/* Show show of an object. */
1339extern void _dl_show_scope (struct link_map *new, int from)
1340 attribute_hidden;
1341
1342extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr);
1343rtld_hidden_proto (_dl_find_dso_for_object)
1344
1345/* Initialization which is normally done by the dynamic linker. */
1346extern void _dl_non_dynamic_init (void)
1347 attribute_hidden;
1348
1349/* Used by static binaries to check the auxiliary vector. */
1350extern void _dl_aux_init (ElfW(auxv_t) *av)
1351 attribute_hidden;
1352
1353/* Initialize the static TLS space for the link map in all existing
1354 threads. */
1355#if PTHREAD_IN_LIBC
1356void _dl_init_static_tls (struct link_map *map) attribute_hidden;
1357#endif
1358static inline void
1359dl_init_static_tls (struct link_map *map)
1360{
1361#if PTHREAD_IN_LIBC
1362 /* The stack list is available to ld.so, so the initialization can
1363 be handled within ld.so directly. */
1364 _dl_init_static_tls (map);
1365#else
1366 GL (dl_init_static_tls) (map);
1367#endif
1368}
1369
1370#ifndef SHARED
1371/* Called before relocating ld.so during static dlopen. This can be
1372 used to partly initialize the dormant ld.so copy in the static
1373 dlopen namespace. */
1374void __rtld_static_init (struct link_map *map) attribute_hidden;
1375#endif
1376
1377/* Return true if the ld.so copy in this namespace is actually active
1378 and working. If false, the dl_open/dlfcn hooks have to be used to
1379 call into the outer dynamic linker (which happens after static
1380 dlopen). */
1381#ifdef SHARED
1382static inline bool
1383rtld_active (void)
1384{
1385 /* The default-initialized variable does not have a non-zero
1386 dl_init_all_dirs member, so this allows us to recognize an
1387 initialized and active ld.so copy. */
1388 return GLRO(dl_init_all_dirs) != NULL;
1389}
1390
1391static inline struct auditstate *
1392link_map_audit_state (struct link_map *l, size_t index)
1393{
1394 if (l == &GL (dl_rtld_map))
1395 /* The auditstate array is stored separately. */
1396 return &GL (dl_rtld_auditstate) [index];
1397 else
1398 {
1399 /* The auditstate array follows the link map in memory. */
1400 struct auditstate *base = (struct auditstate *) (l + 1);
1401 return &base[index];
1402 }
1403}
1404
1405/* Call the la_objsearch from the audit modules from the link map L. If
1406 ORIGNAME is non NULL, it is updated with the revious name prior calling
1407 la_objsearch. */
1408const char *_dl_audit_objsearch (const char *name, struct link_map *l,
1409 unsigned int code)
1410 attribute_hidden;
1411
1412/* Call the la_activity from the audit modules from the link map L and issues
1413 the ACTION argument. */
1414void _dl_audit_activity_map (struct link_map *l, int action)
1415 attribute_hidden;
1416
1417/* Call the la_activity from the audit modules from the link map from the
1418 namespace NSID and issues the ACTION argument. */
1419void _dl_audit_activity_nsid (Lmid_t nsid, int action)
1420 attribute_hidden;
1421
1422/* Call the la_objopen from the audit modules for the link_map L on the
1423 namespace identification NSID. */
1424void _dl_audit_objopen (struct link_map *l, Lmid_t nsid)
1425 attribute_hidden;
1426
1427/* Call the la_objclose from the audit modules for the link_map L. */
1428void _dl_audit_objclose (struct link_map *l)
1429 attribute_hidden;
1430
1431/* Call the la_preinit from the audit modules for the link_map L. */
1432void _dl_audit_preinit (struct link_map *l);
1433
1434/* Call the la_symbind{32,64} from the audit modules for the link_map L. If
1435 RELOC_RESULT is NULL it assumes the symbol to be bind-now and will set
1436 the flags with LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT prior calling
1437 la_symbind{32,64}. */
1438void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
1439 const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,
1440 lookup_t result)
1441 attribute_hidden;
1442/* Same as _dl_audit_symbind, but also sets LA_SYMB_DLSYM flag. */
1443void _dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref,
1444 void **value, lookup_t result);
1445rtld_hidden_proto (_dl_audit_symbind_alt)
1446void _dl_audit_pltenter (struct link_map *l, struct reloc_result *reloc_result,
1447 DL_FIXUP_VALUE_TYPE *value, void *regs,
1448 long int *framesize)
1449 attribute_hidden;
1450void DL_ARCH_FIXUP_ATTRIBUTE _dl_audit_pltexit (struct link_map *l,
1451 ElfW(Word) reloc_arg,
1452 const void *inregs,
1453 void *outregs)
1454 attribute_hidden;
1455#endif /* SHARED */
1456
1457#if PTHREAD_IN_LIBC && defined SHARED
1458/* Recursive locking implementation for use within the dynamic loader.
1459 Used to define the __rtld_lock_lock_recursive and
1460 __rtld_lock_unlock_recursive via <libc-lock.h>. Initialized to a
1461 no-op dummy implementation early. Similar
1462 to GL (dl_rtld_lock_recursive) and GL (dl_rtld_unlock_recursive)
1463 in !PTHREAD_IN_LIBC builds. */
1464extern int (*___rtld_mutex_lock) (pthread_mutex_t *) attribute_hidden;
1465extern int (*___rtld_mutex_unlock) (pthread_mutex_t *lock) attribute_hidden;
1466
1467/* Called after libc has been loaded, but before RELRO is activated.
1468 Used to initialize the function pointers to the actual
1469 implementations. */
1470void __rtld_mutex_init (void) attribute_hidden;
1471#else /* !PTHREAD_IN_LIBC */
1472static inline void
1473__rtld_mutex_init (void)
1474{
1475 /* The initialization happens later (!PTHREAD_IN_LIBC) or is not
1476 needed at all (!SHARED). */
1477}
1478#endif /* !PTHREAD_IN_LIBC */
1479
1480/* Implementation of GL (dl_libc_freeres). */
1481void __rtld_libc_freeres (void) attribute_hidden;
1482
1483void __thread_gscope_wait (void) attribute_hidden;
1484# define THREAD_GSCOPE_WAIT() __thread_gscope_wait ()
1485
1486__END_DECLS
1487
1488#endif /* ldsodefs.h */
1489