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Don't use INTDEF/INTUSE with _dl_argv (bug 14132).
[thirdparty/glibc.git] / sysdeps / generic / ldsodefs.h
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a42195db 1/* Run-time dynamic linker data structures for loaded ELF shared objects.
d4697bc9 2 Copyright (C) 1995-2014 Free Software Foundation, Inc.
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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
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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.
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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
41bdb6e2 13 Lesser General Public License for more details.
a42195db 14
41bdb6e2 15 You should have received a copy of the GNU Lesser General Public
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16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
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18
19#ifndef _LDSODEFS_H
20#define _LDSODEFS_H 1
21
22#include <features.h>
23
3fb55878 24#include <stdbool.h>
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25#define __need_size_t
26#define __need_NULL
27#include <stddef.h>
ef52edfc 28#include <string.h>
e054f494 29#include <stdint.h>
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30
31#include <elf.h>
32#include <dlfcn.h>
5688da55 33#include <fpu_control.h>
d6b5d570 34#include <sys/mman.h>
a42195db 35#include <link.h>
c0282c06 36#include <dl-lookupcfg.h>
ce460d04 37#include <dl-sysdep.h>
c12aa801 38#include <bits/libc-lock.h>
5688da55 39#include <hp-timing.h>
535b764d 40#include <tls.h>
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41
42__BEGIN_DECLS
43
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44#define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
45#define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
46 + DT_EXTRANUM + DT_VALTAGIDX (tag))
47#define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
48 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
49
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50/* We use this macro to refer to ELF types independent of the native wordsize.
51 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
52#define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
53
54/* All references to the value of l_info[DT_PLTGOT],
55 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
88fdf42f 56 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
42ba2c11 57 have to be accessed via the D_PTR macro. The macro is needed since for
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58 most architectures the entry is already relocated - but for some not
59 and we need to relocate at access time. */
a42195db 60#ifdef DL_RO_DYN_SECTION
9dcafc55 61# define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
a42195db 62#else
9dcafc55 63# define D_PTR(map, i) (map)->i->d_un.d_ptr
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64#endif
65
9dcafc55 66/* Result of the lookup functions and how to retrieve the base address. */
c0282c06 67typedef struct link_map *lookup_t;
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68#define LOOKUP_VALUE(map) map
69#define LOOKUP_VALUE_ADDRESS(map) ((map) ? (map)->l_addr : 0)
c0282c06 70
0b3cf801 71/* On some architectures a pointer to a function is not just a pointer
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72 to the actual code of the function but rather an architecture
73 specific descriptor. */
74#ifndef ELF_FUNCTION_PTR_IS_SPECIAL
09bf6406 75# define DL_SYMBOL_ADDRESS(map, ref) \
c0282c06 76 (void *) (LOOKUP_VALUE_ADDRESS (map) + ref->st_value)
09bf6406 77# define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
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78# define DL_CALL_DT_INIT(map, start, argc, argv, env) \
79 ((init_t) (start)) (argc, argv, env)
80# define DL_CALL_DT_FINI(map, start) ((fini_t) (start)) ()
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81#endif
82
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83/* On some architectures dladdr can't use st_size of all symbols this way. */
84#define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
85 ((ADDR) >= (L)->l_addr + (SYM)->st_value \
2ac9ca73 86 && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
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87 && (ADDR) == (L)->l_addr + (SYM)->st_value) \
88 || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
89 && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
90
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91/* Unmap a loaded object, called by _dl_close (). */
92#ifndef DL_UNMAP_IS_SPECIAL
fcccd512 93# define DL_UNMAP(map) _dl_unmap_segments (map)
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94#endif
95
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96/* By default we do not need special support to initialize DSOs loaded
97 by statically linked binaries. */
98#ifndef DL_STATIC_INIT
99# define DL_STATIC_INIT(map)
100#endif
101
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102/* Reloc type classes as returned by elf_machine_type_class().
103 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
104 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
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105 satisfied by any symbol in the executable. Some architectures do
106 not support copy relocations. In this case we define the macro to
107 zero so that the code for handling them gets automatically optimized
108 out. */
cf5a372e 109#define ELF_RTYPE_CLASS_PLT 1
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110#ifndef DL_NO_COPY_RELOCS
111# define ELF_RTYPE_CLASS_COPY 2
112#else
113# define ELF_RTYPE_CLASS_COPY 0
114#endif
cf5a372e 115
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116/* ELF uses the PF_x macros to specify the segment permissions, mmap
117 uses PROT_xxx. In most cases the three macros have the values 1, 2,
118 and 3 but not in a matching order. The following macros allows
119 converting from the PF_x values to PROT_xxx values. */
120#define PF_TO_PROT \
121 ((PROT_READ << (PF_R * 4)) \
122 | (PROT_WRITE << (PF_W * 4)) \
123 | (PROT_EXEC << (PF_X * 4)) \
124 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
125 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
126 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
127 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
128
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129/* The filename itself, or the main program name, if available. */
130#define DSO_FILENAME(name) ((name)[0] ? (name) \
131 : (rtld_progname ?: "<main program>"))
132
133#define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
9d63abbc 134
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135/* For the version handling we need an array with only names and their
136 hash values. */
137struct r_found_version
138 {
139 const char *name;
140 ElfW(Word) hash;
141
142 int hidden;
143 const char *filename;
144 };
145
146/* We want to cache information about the searches for shared objects. */
147
148enum r_dir_status { unknown, nonexisting, existing };
149
150struct r_search_path_elem
151 {
152 /* This link is only used in the `all_dirs' member of `r_search_path'. */
153 struct r_search_path_elem *next;
154
155 /* Strings saying where the definition came from. */
156 const char *what;
157 const char *where;
158
159 /* Basename for this search path element. The string must end with
160 a slash character. */
161 const char *dirname;
162 size_t dirnamelen;
163
164 enum r_dir_status status[0];
165 };
166
167struct r_strlenpair
168 {
169 const char *str;
170 size_t len;
171 };
172
173
174/* A data structure for a simple single linked list of strings. */
175struct libname_list
176 {
177 const char *name; /* Name requested (before search). */
178 struct libname_list *next; /* Link to next name for this object. */
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179 int dont_free; /* Flag whether this element should be freed
180 if the object is not entirely unloaded. */
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181 };
182
183
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184/* Bit masks for the objects which valid callers can come from to
185 functions with restricted interface. */
186enum allowmask
187 {
188 allow_libc = 1,
189 allow_libdl = 2,
190 allow_libpthread = 4,
191 allow_ldso = 8
192 };
193
194
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195struct audit_ifaces
196{
197 void (*activity) (uintptr_t *, unsigned int);
198 char *(*objsearch) (const char *, uintptr_t *, unsigned int);
199 unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
200 void (*preinit) (uintptr_t *);
201 union
202 {
203 uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
204 uintptr_t *, unsigned int *, const char *);
205 uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
206 uintptr_t *, unsigned int *, const char *);
207 };
208 union
209 {
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210#ifdef ARCH_PLTENTER_MEMBERS
211 ARCH_PLTENTER_MEMBERS;
212#endif
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213 };
214 union
215 {
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216#ifdef ARCH_PLTEXIT_MEMBERS
217 ARCH_PLTEXIT_MEMBERS;
218#endif
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219 };
220 unsigned int (*objclose) (uintptr_t *);
221
222 struct audit_ifaces *next;
223};
224
225
a42195db 226/* Test whether given NAME matches any of the names of the given object. */
871b9158 227extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
dd272e57 228 internal_function;
a42195db 229
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230/* Compute next higher prime number. */
231extern unsigned long int _dl_higher_prime_number (unsigned long int n)
232 internal_function;
233
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234/* Function used as argument for `_dl_receive_error' function. The
235 arguments are the error code, error string, and the objname the
236 error occurred in. */
237typedef void (*receiver_fct) (int, const char *, const char *);
238\f
239/* Internal functions of the run-time dynamic linker.
240 These can be accessed if you link again the dynamic linker
241 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
242 but are not normally of interest to user programs.
243
244 The `-ldl' library functions in <dlfcn.h> provide a simple
245 user interface to run-time dynamic linking. */
246
247
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248#ifndef SHARED
249# define EXTERN extern
250# define GL(name) _##name
251#else
252# define EXTERN
403e0597 253# ifdef IS_IN_rtld
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254# define GL(name) _rtld_local._##name
255# else
256# define GL(name) _rtld_global._##name
257# endif
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258struct rtld_global
259{
260#endif
261 /* Don't change the order of the following elements. 'dl_loaded'
262 must remain the first element. Forever. */
263
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264/* Non-shared code has no support for multiple namespaces. */
265#ifdef SHARED
266# define DL_NNS 16
267#else
268# define DL_NNS 1
269#endif
270 EXTERN struct link_namespaces
271 {
9dcafc55 272 /* A pointer to the map for the main map. */
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273 struct link_map *_ns_loaded;
274 /* Number of object in the _dl_loaded list. */
275 unsigned int _ns_nloaded;
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276 /* Direct pointer to the searchlist of the main object. */
277 struct r_scope_elem *_ns_main_searchlist;
278 /* This is zero at program start to signal that the global scope map is
279 allocated by rtld. Later it keeps the size of the map. It might be
280 reset if in _dl_close if the last global object is removed. */
281 size_t _ns_global_scope_alloc;
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282 /* Search table for unique objects. */
283 struct unique_sym_table
284 {
bea9b193 285 __rtld_lock_define_recursive (, lock)
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286 struct unique_sym
287 {
288 uint32_t hashval;
289 const char *name;
290 const ElfW(Sym) *sym;
5e4287d1 291 const struct link_map *map;
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292 } *entries;
293 size_t size;
294 size_t n_elements;
295 void (*free) (void *);
296 } _ns_unique_sym_table;
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297 /* Keep track of changes to each namespace' list. */
298 struct r_debug _ns_debug;
c0f62c56 299 } _dl_ns[DL_NNS];
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300 /* One higher than index of last used namespace. */
301 EXTERN size_t _dl_nns;
d6b5d570 302
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303 /* During the program run we must not modify the global data of
304 loaded shared object simultanously in two threads. Therefore we
305 protect `_dl_open' and `_dl_close' in dl-close.c.
306
307 This must be a recursive lock since the initializer function of
308 the loaded object might as well require a call to this function.
309 At this time it is not anymore a problem to modify the tables. */
d3c9f895 310 __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
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311 /* This lock is used to keep __dl_iterate_phdr from inspecting the
312 list of loaded objects while an object is added to or removed
313 from that list. */
314 __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
5688da55 315
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316 /* Incremented whenever something may have been added to dl_loaded. */
317 EXTERN unsigned long long _dl_load_adds;
bed12f78 318
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319 /* The object to be initialized first. */
320 EXTERN struct link_map *_dl_initfirst;
321
8c682bb2 322#if HP_SMALL_TIMING_AVAIL
ccdf0cab 323 /* Start time on CPU clock. */
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324 EXTERN hp_timing_t _dl_cpuclock_offset;
325#endif
326
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327 /* Map of shared object to be profiled. */
328 EXTERN struct link_map *_dl_profile_map;
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329
330 /* Counters for the number of relocations performed. */
331 EXTERN unsigned long int _dl_num_relocations;
332 EXTERN unsigned long int _dl_num_cache_relocations;
333
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334 /* List of search directories. */
335 EXTERN struct r_search_path_elem *_dl_all_dirs;
d6b5d570 336
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337#ifdef _LIBC_REENTRANT
338 EXTERN void **(*_dl_error_catch_tsd) (void) __attribute__ ((const));
339#endif
340
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341 /* Structure describing the dynamic linker itself. We need to
342 reserve memory for the data the audit libraries need. */
d6b5d570 343 EXTERN struct link_map _dl_rtld_map;
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344#ifdef SHARED
345 struct auditstate audit_data[DL_NNS];
346#endif
ce460d04 347
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348#if defined SHARED && defined _LIBC_REENTRANT \
349 && defined __rtld_lock_default_lock_recursive
350 EXTERN void (*_dl_rtld_lock_recursive) (void *);
351 EXTERN void (*_dl_rtld_unlock_recursive) (void *);
352#endif
353
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354 /* If loading a shared object requires that we make the stack executable
355 when it was not, we do it by calling this function.
356 It returns an errno code or zero on success. */
d1fc817e 357 EXTERN int (*_dl_make_stack_executable_hook) (void **) internal_function;
ecdeaac0 358
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359 /* Prevailing state of the stack, PF_X indicating it's executable. */
360 EXTERN ElfW(Word) _dl_stack_flags;
361
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362 /* Flag signalling whether there are gaps in the module ID allocation. */
363 EXTERN bool _dl_tls_dtv_gaps;
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364 /* Highest dtv index currently needed. */
365 EXTERN size_t _dl_tls_max_dtv_idx;
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366 /* Information about the dtv slots. */
367 EXTERN struct dtv_slotinfo_list
368 {
369 size_t len;
370 struct dtv_slotinfo_list *next;
371 struct dtv_slotinfo
372 {
373 size_t gen;
374 struct link_map *map;
375 } slotinfo[0];
376 } *_dl_tls_dtv_slotinfo_list;
377 /* Number of modules in the static TLS block. */
378 EXTERN size_t _dl_tls_static_nelem;
379 /* Size of the static TLS block. */
380 EXTERN size_t _dl_tls_static_size;
381 /* Size actually allocated in the static TLS block. */
382 EXTERN size_t _dl_tls_static_used;
383 /* Alignment requirement of the static TLS block. */
384 EXTERN size_t _dl_tls_static_align;
385
386/* Number of additional entries in the slotinfo array of each slotinfo
387 list element. A large number makes it almost certain take we never
388 have to iterate beyond the first element in the slotinfo list. */
11bf311e 389#define TLS_SLOTINFO_SURPLUS (62)
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390
391/* Number of additional slots in the dtv allocated. */
11bf311e 392#define DTV_SURPLUS (14)
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393
394 /* Initial dtv of the main thread, not allocated with normal malloc. */
395 EXTERN void *_dl_initial_dtv;
396 /* Generation counter for the dtv. */
397 EXTERN size_t _dl_tls_generation;
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398
399 EXTERN void (*_dl_init_static_tls) (struct link_map *);
68dc80ca 400
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401 EXTERN void (*_dl_wait_lookup_done) (void);
402
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403 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
404 EXTERN struct dl_scope_free_list
405 {
406 size_t count;
385b4cf4 407 void *list[50];
e4eb675d 408 } *_dl_scope_free_list;
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409#ifdef SHARED
410};
5fe14d96 411# define __rtld_global_attribute__
403e0597 412# ifdef IS_IN_rtld
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413# ifdef HAVE_SDATA_SECTION
414# define __rtld_local_attribute__ \
0d01dace 415 __attribute__ ((visibility ("hidden"), section (".sdata")))
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416# undef __rtld_global_attribute__
417# define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
0d01dace 418# else
11bf311e 419# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
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420# endif
421extern struct rtld_global _rtld_local __rtld_local_attribute__;
021723ab 422# undef __rtld_local_attribute__
0d01dace 423# endif
5fe14d96 424extern struct rtld_global _rtld_global __rtld_global_attribute__;
021723ab 425# undef __rtld_global_attribute__
d6b5d570 426#endif
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427
428#ifndef SHARED
429# define GLRO(name) _##name
430#else
431# ifdef IS_IN_rtld
432# define GLRO(name) _rtld_local_ro._##name
433# else
434# define GLRO(name) _rtld_global_ro._##name
435# endif
436struct rtld_global_ro
437{
438#endif
439
440 /* If nonzero the appropriate debug information is printed. */
441 EXTERN int _dl_debug_mask;
442#define DL_DEBUG_LIBS (1 << 0)
443#define DL_DEBUG_IMPCALLS (1 << 1)
444#define DL_DEBUG_BINDINGS (1 << 2)
445#define DL_DEBUG_SYMBOLS (1 << 3)
446#define DL_DEBUG_VERSIONS (1 << 4)
447#define DL_DEBUG_RELOC (1 << 5)
448#define DL_DEBUG_FILES (1 << 6)
449#define DL_DEBUG_STATISTICS (1 << 7)
7a11603d 450#define DL_DEBUG_UNUSED (1 << 8)
73d7af4f 451#define DL_DEBUG_SCOPES (1 << 9)
20c37dfd 452/* These two are used only internally. */
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453#define DL_DEBUG_HELP (1 << 10)
454#define DL_DEBUG_PRELINK (1 << 11)
20c37dfd 455
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456 /* OS version. */
457 EXTERN unsigned int _dl_osversion;
458 /* Platform name. */
459 EXTERN const char *_dl_platform;
460 EXTERN size_t _dl_platformlen;
461
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462 /* Cached value of `getpagesize ()'. */
463 EXTERN size_t _dl_pagesize;
464
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465 /* Do we read from ld.so.cache? */
466 EXTERN int _dl_inhibit_cache;
467
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468 /* Copy of the content of `_dl_main_searchlist' at startup time. */
469 EXTERN struct r_scope_elem _dl_initial_searchlist;
470
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471 /* CLK_TCK as reported by the kernel. */
472 EXTERN int _dl_clktck;
473
474 /* If nonzero print warnings messages. */
475 EXTERN int _dl_verbose;
476
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477 /* File descriptor to write debug messages to. */
478 EXTERN int _dl_debug_fd;
479
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480 /* Do we do lazy relocations? */
481 EXTERN int _dl_lazy;
482
483 /* Nonzero if runtime lookups should not update the .got/.plt. */
484 EXTERN int _dl_bind_not;
485
486 /* Nonzero if references should be treated as weak during runtime
487 linking. */
488 EXTERN int _dl_dynamic_weak;
489
490 /* Default floating-point control word. */
491 EXTERN fpu_control_t _dl_fpu_control;
492
493 /* Expected cache ID. */
494 EXTERN int _dl_correct_cache_id;
495
496 /* Mask for hardware capabilities that are available. */
404a4e2f 497 EXTERN uint64_t _dl_hwcap;
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498
499 /* Mask for important hardware capabilities we honour. */
404a4e2f 500 EXTERN uint64_t _dl_hwcap_mask;
20c37dfd 501
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502 /* Pointer to the auxv list supplied to the program at startup. */
503 EXTERN ElfW(auxv_t) *_dl_auxv;
504
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505 /* Get architecture specific definitions. */
506#define PROCINFO_DECL
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507#ifndef PROCINFO_CLASS
508# define PROCINFO_CLASS EXTERN
509#endif
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510#include <dl-procinfo.c>
511
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512 /* Names of shared object for which the RPATH should be ignored. */
513 EXTERN const char *_dl_inhibit_rpath;
514
515 /* Location of the binary. */
516 EXTERN const char *_dl_origin_path;
517
518 /* -1 if the dynamic linker should honor library load bias,
519 0 if not, -2 use the default (honor biases for normal
520 binaries, don't honor for PIEs). */
521 EXTERN ElfW(Addr) _dl_use_load_bias;
522
523 /* Name of the shared object to be profiled (if any). */
524 EXTERN const char *_dl_profile;
525 /* Filename of the output file. */
526 EXTERN const char *_dl_profile_output;
527 /* Name of the object we want to trace the prelinking. */
528 EXTERN const char *_dl_trace_prelink;
529 /* Map of shared object to be prelink traced. */
530 EXTERN struct link_map *_dl_trace_prelink_map;
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531
532 /* All search directories defined at startup. */
533 EXTERN struct r_search_path_elem *_dl_init_all_dirs;
534
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535#ifdef NEED_DL_SYSINFO
536 /* Syscall handling improvements. This is very specific to x86. */
537 EXTERN uintptr_t _dl_sysinfo;
30e32d23 538#endif
20c37dfd 539
7775448e 540#ifdef NEED_DL_SYSINFO_DSO
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541 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
542 This points to its ELF header. */
543 EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
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544
545 /* At startup time we set up the normal DSO data structure for it,
546 and this points to it. */
547 EXTERN struct link_map *_dl_sysinfo_map;
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548#endif
549
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550 /* Mask for more hardware capabilities that are available on some
551 platforms. */
552 EXTERN uint64_t _dl_hwcap2;
553
20c37dfd 554#ifdef SHARED
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555 /* We add a function table to _rtld_global which is then used to
556 call the function instead of going through the PLT. The result
557 is that we can avoid exporting the functions and we do not jump
558 PLT relocations in libc.so. */
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559 void (*_dl_debug_printf) (const char *, ...)
560 __attribute__ ((__format__ (__printf__, 1, 2)));
561 int (internal_function *_dl_catch_error) (const char **, const char **,
6dffebd8 562 bool *, void (*) (void *), void *);
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563 void (internal_function *_dl_signal_error) (int, const char *, const char *,
564 const char *);
154d10bd 565 void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
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566 lookup_t (internal_function *_dl_lookup_symbol_x) (const char *,
567 struct link_map *,
568 const ElfW(Sym) **,
569 struct r_scope_elem *[],
570 const struct r_found_version *,
571 int, int,
572 struct link_map *);
eec8b6ca 573 int (*_dl_check_caller) (const void *, enum allowmask);
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574 void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
575 Lmid_t nsid, int argc, char *argv[], char *env[]);
576 void (*_dl_close) (void *map);
93025f93 577 void *(*_dl_tls_get_addr_soft) (struct link_map *);
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578#ifdef HAVE_DL_DISCOVER_OSVERSION
579 int (*_dl_discover_osversion) (void);
580#endif
154d10bd 581
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582 /* List of auditing interfaces. */
583 struct audit_ifaces *_dl_audit;
584 unsigned int _dl_naudit;
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585
586 /* 0 if internal pointer values should not be guarded, 1 if they should. */
587 EXTERN int _dl_pointer_guard;
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588};
589# define __rtld_global_attribute__
590# ifdef IS_IN_rtld
11bf311e 591# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
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592extern struct rtld_global_ro _rtld_local_ro
593 attribute_relro __rtld_local_attribute__;
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594extern struct rtld_global_ro _rtld_global_ro
595 attribute_relro __rtld_global_attribute__;
021723ab 596# undef __rtld_local_attribute__
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597# else
598/* We cheat a bit here. We declare the variable as as const even
599 though it is at startup. */
600extern const struct rtld_global_ro _rtld_global_ro
601 attribute_relro __rtld_global_attribute__;
602# endif
021723ab 603# undef __rtld_global_attribute__
20c37dfd 604#endif
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605#undef EXTERN
606
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607#ifndef SHARED
608/* dl-support.c defines these and initializes them early on. */
dc0a0263 609extern const ElfW(Phdr) *_dl_phdr;
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610extern size_t _dl_phnum;
611#endif
612
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613#ifdef IS_IN_rtld
614/* This is the initial value of GL(dl_error_catch_tsd).
615 A non-TLS libpthread will change it. */
616extern void **_dl_initial_error_catch_tsd (void) __attribute__ ((const))
617 attribute_hidden;
618#endif
619
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620/* This is the initial value of GL(dl_make_stack_executable_hook).
621 A threads library can change it. */
d1fc817e 622extern int _dl_make_stack_executable (void **stack_endp) internal_function;
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623rtld_hidden_proto (_dl_make_stack_executable)
624
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625/* Variable pointing to the end of the stack (or close to it). This value
626 must be constant over the runtime of the application. Some programs
627 might use the variable which results in copy relocations on some
628 platforms. But this does not matter, ld.so can always use the local
629 copy. */
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630extern void *__libc_stack_end
631#ifndef LIBC_STACK_END_NOT_RELRO
632 attribute_relro
633#endif
634 ;
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635rtld_hidden_proto (__libc_stack_end)
636
d6b5d570 637/* Parameters passed to the dynamic linker. */
392a6b52 638extern int _dl_argc attribute_hidden attribute_relro;
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639extern char **_dl_argv
640#ifndef DL_ARGV_NOT_RELRO
641 attribute_relro
642#endif
643 ;
4243cbea 644rtld_hidden_proto (_dl_argv)
403e0597 645#ifdef IS_IN_rtld
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646extern unsigned int _dl_skip_args attribute_hidden
647# ifndef DL_ARGV_NOT_RELRO
648 attribute_relro
649# endif
650 ;
651extern unsigned int _dl_skip_args_internal attribute_hidden
652# ifndef DL_ARGV_NOT_RELRO
653 attribute_relro
654# endif
655 ;
e6caf4e1 656#endif
4243cbea 657#define rtld_progname _dl_argv[0]
d6b5d570 658
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659/* Flag set at startup and cleared when the last initializer has run. */
660extern int _dl_starting_up;
661weak_extern (_dl_starting_up)
b5b9cfc4 662#ifdef IS_IN_rtld
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663extern int _dl_starting_up_internal attribute_hidden;
664#endif
f55727ca 665
965cb60a 666/* Random data provided by the kernel. */
d09580b1 667extern void *_dl_random attribute_hidden attribute_relro;
965cb60a 668
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669/* OS-dependent function to open the zero-fill device. */
670extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
671
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672
673/* Write message on the debug file descriptor. The parameters are
674 interpreted as for a `printf' call. All the lines start with a
675 tag showing the PID. */
676extern void _dl_debug_printf (const char *fmt, ...)
154d10bd 677 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
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678
679/* Write message on the debug file descriptor. The parameters are
680 interpreted as for a `printf' call. All the lines buf the first
681 start with a tag showing the PID. */
682extern void _dl_debug_printf_c (const char *fmt, ...)
683 __attribute__ ((__format__ (__printf__, 1, 2)));
684
685
686/* Write a message on the specified descriptor FD. The parameters are
687 interpreted as for a `printf' call. */
688extern void _dl_dprintf (int fd, const char *fmt, ...)
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689 __attribute__ ((__format__ (__printf__, 2, 3)))
690 attribute_hidden;
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691
692/* Write a message on the specified descriptor standard output. The
693 parameters are interpreted as for a `printf' call. */
694#define _dl_printf(fmt, args...) \
695 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
696
697/* Write a message on the specified descriptor standard error. The
698 parameters are interpreted as for a `printf' call. */
699#define _dl_error_printf(fmt, args...) \
700 _dl_dprintf (STDERR_FILENO, fmt, ##args)
701
702/* Write a message on the specified descriptor standard error and exit
703 the program. The parameters are interpreted as for a `printf' call. */
704#define _dl_fatal_printf(fmt, args...) \
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705 do \
706 { \
b5ba0659 707 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
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708 _exit (127); \
709 } \
710 while (1)
711
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712
713/* This function is called by all the internal dynamic linker functions
714 when they encounter an error. ERRCODE is either an `errno' code or
715 zero; OBJECT is the name of the problematical shared object, or null if
716 it is a general problem; ERRSTRING is a string describing the specific
717 problem. */
8e17ea58 718extern void _dl_signal_error (int errcode, const char *object,
407fe3bb 719 const char *occurred, const char *errstring)
6ce3881d 720 internal_function __attribute__ ((__noreturn__)) attribute_hidden;
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721
722/* Like _dl_signal_error, but may return when called in the context of
723 _dl_receive_error. */
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724extern void _dl_signal_cerror (int errcode, const char *object,
725 const char *occation, const char *errstring)
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726 internal_function;
727
728/* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
729 `_dl_catch_error' the operation is resumed after the OPERATE
730 function returns.
731 ARGS is passed as argument to OPERATE. */
732extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
733 void *args)
734 internal_function;
735
736
737/* Open the shared object NAME and map in its segments.
738 LOADER's DT_RPATH is used in searching for NAME.
8e9f92e9 739 If the object is already opened, returns its existing map. */
a42195db 740extern struct link_map *_dl_map_object (struct link_map *loader,
8e9f92e9 741 const char *name,
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742 int type, int trace_mode, int mode,
743 Lmid_t nsid)
6ce3881d 744 internal_function attribute_hidden;
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745
746/* Call _dl_map_object on the dependencies of MAP, and set up
747 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
748 loaded objects that will be inserted into MAP->l_searchlist after MAP
749 but before its dependencies. */
750extern void _dl_map_object_deps (struct link_map *map,
751 struct link_map **preloads,
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752 unsigned int npreloads, int trace_mode,
753 int open_mode)
6ce3881d 754 internal_function attribute_hidden;
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755
756/* Cache the locations of MAP's hash table. */
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757extern void _dl_setup_hash (struct link_map *map)
758 internal_function attribute_hidden;
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759
760
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761/* Collect the directories in the search path for LOADER's dependencies.
762 The data structure is defined in <dlfcn.h>. If COUNTING is true,
763 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
764 by a previous call with COUNTING set, and SI must point to SI->dls_size
765 bytes to be used in filling in the result. */
766extern void _dl_rtld_di_serinfo (struct link_map *loader,
767 Dl_serinfo *si, bool counting)
768 internal_function;
769
770
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771/* Search loaded objects' symbol tables for a definition of the symbol
772 referred to by UNDEF. *SYM is the symbol table entry containing the
773 reference; it is replaced with the defining symbol, and the base load
774 address of the defining object is returned. SYMBOL_SCOPE is a
775 null-terminated list of object scopes to search; each object's
776 l_searchlist (i.e. the segment of the dependency tree starting at that
777 object) is searched in turn. REFERENCE_NAME should name the object
778 containing the reference; it is used in error messages.
cf5a372e 779 TYPE_CLASS describes the type of symbol we are looking for. */
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780enum
781 {
782 /* If necessary add dependency between user and provider object. */
783 DL_LOOKUP_ADD_DEPENDENCY = 1,
784 /* Return most recent version instead of default version for
785 unversioned lookup. */
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786 DL_LOOKUP_RETURN_NEWEST = 2,
787 /* Set if dl_lookup* called with GSCOPE lock held. */
788 DL_LOOKUP_GSCOPE_LOCK = 4,
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789 };
790
a42195db 791/* Lookup versioned symbol. */
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792extern lookup_t _dl_lookup_symbol_x (const char *undef,
793 struct link_map *undef_map,
794 const ElfW(Sym) **sym,
795 struct r_scope_elem *symbol_scope[],
796 const struct r_found_version *version,
4e35ef2c 797 int type_class, int flags,
021723ab 798 struct link_map *skip_map)
6ce3881d 799 internal_function attribute_hidden;
a42195db 800
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801
802/* Look up symbol NAME in MAP's scope and return its run-time address. */
803extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name)
804 internal_function;
805
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806/* Add the new link_map NEW to the end of the namespace list. */
807extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
808 internal_function attribute_hidden;
809
810/* Allocate a `struct link_map' for a new object being loaded. */
a42195db 811extern struct link_map *_dl_new_object (char *realname, const char *libname,
1fc07491 812 int type, struct link_map *loader,
c0f62c56 813 int mode, Lmid_t nsid)
6ce3881d 814 internal_function attribute_hidden;
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815
816/* Relocate the given object (if it hasn't already been).
817 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
2ca285b0 818 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
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819extern void _dl_relocate_object (struct link_map *map,
820 struct r_scope_elem *scope[],
2ca285b0 821 int reloc_mode, int consider_profiling)
6ce3881d 822 attribute_hidden;
a42195db 823
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824/* Protect PT_GNU_RELRO area. */
825extern void _dl_protect_relro (struct link_map *map)
826 internal_function attribute_hidden;
827
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828/* Call _dl_signal_error with a message about an unhandled reloc type.
829 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
830 PLT is nonzero if this was a PLT reloc; it just affects the message. */
831extern void _dl_reloc_bad_type (struct link_map *map,
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832 unsigned int type, int plt)
833 internal_function __attribute__ ((__noreturn__));
a42195db 834
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835/* Resolve conflicts if prelinking. */
836extern void _dl_resolve_conflicts (struct link_map *l,
837 ElfW(Rela) *conflict,
838 ElfW(Rela) *conflictend);
839
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840/* Check the version dependencies of all objects available through
841 MAP. If VERBOSE print some more diagnostics. */
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842extern int _dl_check_all_versions (struct link_map *map, int verbose,
843 int trace_mode)
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844 internal_function;
845
846/* Check the version dependencies for MAP. If VERBOSE print some more
847 diagnostics. */
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848extern int _dl_check_map_versions (struct link_map *map, int verbose,
849 int trace_mode)
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850 internal_function;
851
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852/* Initialize the object in SCOPE by calling the constructors with
853 ARGC, ARGV, and ENV as the parameters. */
854extern void _dl_init (struct link_map *main_map, int argc, char **argv,
154d10bd 855 char **env) internal_function attribute_hidden;
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856
857/* Call the finalizer functions of all shared objects whose
858 initializer functions have completed. */
859extern void _dl_fini (void) internal_function;
860
c3381f3e 861/* Sort array MAPS according to dependencies of the contained objects. */
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862extern void _dl_sort_fini (struct link_map **maps, size_t nmaps, char *used,
863 Lmid_t ns)
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864 internal_function;
865
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866/* The dynamic linker calls this function before and having changing
867 any shared object mappings. The `r_state' member of `struct r_debug'
868 says what change is taking place. This function's address is
869 the value of the `r_brk' member. */
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870extern void _dl_debug_state (void);
871rtld_hidden_proto (_dl_debug_state)
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872
873/* Initialize `struct r_debug' if it has not already been done. The
874 argument is the run-time load address of the dynamic linker, to be put
875 in the `r_ldbase' member. Returns the address of the structure. */
29f97654 876extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
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877 internal_function;
878
879/* Initialize the basic data structure for the search paths. */
880extern void _dl_init_paths (const char *library_path) internal_function;
881
882/* Gather the information needed to install the profiling tables and start
883 the timers. */
53bfdc1c 884extern void _dl_start_profile (void) internal_function attribute_hidden;
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885
886/* The actual functions used to keep book on the calls. */
887extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
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888extern void _dl_mcount_internal (ElfW(Addr) frompc, ElfW(Addr) selfpc)
889 attribute_hidden;
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890
891/* This function is simply a wrapper around the _dl_mcount function
892 which does not require a FROMPC parameter since this is the
893 calling function. */
894extern void _dl_mcount_wrapper (void *selfpc);
895
896/* Show the members of the auxiliary array passed up from the kernel. */
897extern void _dl_show_auxv (void) internal_function;
898
899/* Return all environment variables starting with `LD_', one after the
900 other. */
901extern char *_dl_next_ld_env_entry (char ***position) internal_function;
902
903/* Return an array with the names of the important hardware capabilities. */
904extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform,
905 size_t paltform_len,
906 size_t *sz,
907 size_t *max_capstrlen)
908 internal_function;
909
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910/* Look up NAME in ld.so.cache and return the file name stored there,
911 or null if none is found. */
912extern const char *_dl_load_cache_lookup (const char *name)
913 internal_function;
914
915/* If the system does not support MAP_COPY we cannot leave the file open
916 all the time since this would create problems when the file is replaced.
917 Therefore we provide this function to close the file and open it again
918 once needed. */
154d10bd 919extern void _dl_unload_cache (void) attribute_hidden;
48896b9d 920
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921/* System-dependent function to read a file's whole contents in the
922 most convenient manner available. *SIZEP gets the size of the
923 file. On error MAP_FAILED is returned. */
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924extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
925 int prot)
6ce3881d 926 internal_function attribute_hidden;
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927
928/* System-specific function to do initial startup for the dynamic linker.
929 After this, file access calls and getenv must work. This is responsible
930 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
931 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
932extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
933 void (*dl_main) (const ElfW(Phdr) *phdr,
934 ElfW(Word) phnum,
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935 ElfW(Addr) *user_entry,
936 ElfW(auxv_t) *auxv))
6ce3881d 937 attribute_hidden;
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938
939extern void _dl_sysdep_start_cleanup (void)
6ce3881d 940 internal_function attribute_hidden;
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941
942
3fb55878 943/* Determine next available module ID. */
68dc80ca 944extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden;
3fb55878 945
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946/* Count the modules with TLS segments. */
947extern size_t _dl_count_modids (void) internal_function attribute_hidden;
948
3fb55878 949/* Calculate offset of the TLS blocks in the static TLS block. */
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950extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden;
951
952/* Set up the data structures for TLS, when they were not set up at startup.
953 Returns nonzero on malloc failure.
954 This is called from _dl_map_object_from_fd or by libpthread. */
955extern int _dl_tls_setup (void) internal_function;
956rtld_hidden_proto (_dl_tls_setup)
3fb55878 957
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958/* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
959extern void *_dl_allocate_tls (void *mem) internal_function;
733f25e6 960rtld_hidden_proto (_dl_allocate_tls)
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961
962/* Get size and alignment requirements of the static TLS block. */
963extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp)
964 internal_function;
a816b435 965
adc12574 966extern void _dl_allocate_static_tls (struct link_map *map)
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967 internal_function attribute_hidden;
968
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969/* These are internal entry points to the two halves of _dl_allocate_tls,
970 only used within rtld.c itself at startup time. */
971extern void *_dl_allocate_tls_storage (void)
68dc80ca 972 internal_function attribute_hidden;
209a8ca3 973extern void *_dl_allocate_tls_init (void *) internal_function;
68dc80ca 974rtld_hidden_proto (_dl_allocate_tls_init)
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975
976/* Deallocate memory allocated with _dl_allocate_tls. */
9a1eb38e 977extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb) internal_function;
733f25e6 978rtld_hidden_proto (_dl_deallocate_tls)
3fb55878 979
adc12574 980extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
adc12574 981
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982/* Find origin of the executable. */
983extern const char *_dl_get_origin (void) attribute_hidden;
984
985/* Count DSTs. */
986extern size_t _dl_dst_count (const char *name, int is_path) attribute_hidden;
987
988/* Substitute DST values. */
989extern char *_dl_dst_substitute (struct link_map *l, const char *name,
990 char *result, int is_path) attribute_hidden;
991
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992/* Check validity of the caller. */
993extern int _dl_check_caller (const void *caller, enum allowmask mask)
994 attribute_hidden;
995
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996/* Open the shared object NAME, relocate it, and run its initializer if it
997 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
998 the object is already opened, returns its existing map. */
999extern void *_dl_open (const char *name, int mode, const void *caller,
1000 Lmid_t nsid, int argc, char *argv[], char *env[])
1001 attribute_hidden;
1002
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1003/* Free or queue for freeing scope OLD. If other threads might be
1004 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1005 old scope, OLD can't be freed until no thread is using it. */
385b4cf4 1006extern int _dl_scope_free (void *) attribute_hidden;
e4eb675d 1007
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1008/* Add module to slot information data. */
1009extern void _dl_add_to_slotinfo (struct link_map *l) attribute_hidden;
1010
1011/* Update slot information data for at least the generation of the
1012 module with the given index. */
1013extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid);
1014
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1015/* Look up the module's TLS block as for __tls_get_addr,
1016 but never touch anything. Return null if it's not allocated yet. */
93025f93 1017extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
d78efd9f 1018
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1019extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
1020 internal_function attribute_hidden;
d78efd9f 1021
73d7af4f 1022/* Show show of an object. */
174baab3 1023extern void _dl_show_scope (struct link_map *new, int from);
73d7af4f 1024
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1025extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr)
1026 internal_function;
1027rtld_hidden_proto (_dl_find_dso_for_object)
1028
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1029/* Initialization which is normally done by the dynamic linker. */
1030extern void _dl_non_dynamic_init (void) internal_function;
1031
1032/* Used by static binaries to check the auxiliary vector. */
1033extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function;
1034
1035
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1036__END_DECLS
1037
1038#endif /* ldsodefs.h */