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