Updated to fedora-glibc-20060710T2206
[glibc.git] / sysdeps / generic / ldsodefs.h
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1 /* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2003, 2004, 2005, 2006 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #ifndef _LDSODEFS_H
21 #define _LDSODEFS_H 1
23 #include <features.h>
25 #include <stdbool.h>
26 #define __need_size_t
27 #define __need_NULL
28 #include <stddef.h>
29 #include <string.h>
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 <bits/libc-lock.h>
39 #include <hp-timing.h>
40 #include <tls.h>
42 __BEGIN_DECLS
44 /* We use this macro to refer to ELF types independent of the native wordsize.
45 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
46 #define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
48 /* All references to the value of l_info[DT_PLTGOT],
49 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
50 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
51 have to be accessed via the D_PTR macro. The macro is needed since for
52 most architectures the entry is already relocated - but for some not
53 and we need to relocate at access time. */
54 #ifdef DL_RO_DYN_SECTION
55 # define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
56 #else
57 # define D_PTR(map, i) (map)->i->d_un.d_ptr
58 #endif
60 /* Result of the lookup functions and how to retrieve the base address. */
61 typedef struct link_map *lookup_t;
62 # define LOOKUP_VALUE(map) map
63 # define LOOKUP_VALUE_ADDRESS(map) ((map) ? (map)->l_addr : 0)
65 /* On some architectures a pointer to a function is not just a pointer
66 to the actual code of the function but rather an architecture
67 specific descriptor. */
68 #ifndef ELF_FUNCTION_PTR_IS_SPECIAL
69 # define DL_SYMBOL_ADDRESS(map, ref) \
70 (void *) (LOOKUP_VALUE_ADDRESS (map) + ref->st_value)
71 # define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
72 # define DL_DT_INIT_ADDRESS(map, start) (start)
73 # define DL_DT_FINI_ADDRESS(map, start) (start)
74 #endif
76 /* On some architectures dladdr can't use st_size of all symbols this way. */
77 #define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
78 ((ADDR) >= (L)->l_addr + (SYM)->st_value \
79 && (((SYM)->st_size == 0 \
80 && (ADDR) == (L)->l_addr + (SYM)->st_value) \
81 || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
82 && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
84 /* Unmap a loaded object, called by _dl_close (). */
85 #ifndef DL_UNMAP_IS_SPECIAL
86 # define DL_UNMAP(map) \
87 __munmap ((void *) (map)->l_map_start, \
88 (map)->l_map_end - (map)->l_map_start)
89 #endif
91 /* By default we do not need special support to initialize DSOs loaded
92 by statically linked binaries. */
93 #ifndef DL_STATIC_INIT
94 # define DL_STATIC_INIT(map)
95 #endif
97 /* Reloc type classes as returned by elf_machine_type_class().
98 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
99 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
100 satisfied by any symbol in the executable. Some architectures do
101 not support copy relocations. In this case we define the macro to
102 zero so that the code for handling them gets automatically optimized
103 out. */
104 #define ELF_RTYPE_CLASS_PLT 1
105 #ifndef DL_NO_COPY_RELOCS
106 # define ELF_RTYPE_CLASS_COPY 2
107 #else
108 # define ELF_RTYPE_CLASS_COPY 0
109 #endif
111 /* ELF uses the PF_x macros to specify the segment permissions, mmap
112 uses PROT_xxx. In most cases the three macros have the values 1, 2,
113 and 3 but not in a matching order. The following macros allows
114 converting from the PF_x values to PROT_xxx values. */
115 #define PF_TO_PROT \
116 ((PROT_READ << (PF_R * 4)) \
117 | (PROT_WRITE << (PF_W * 4)) \
118 | (PROT_EXEC << (PF_X * 4)) \
119 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
120 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
121 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
122 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
125 /* For the version handling we need an array with only names and their
126 hash values. */
127 struct r_found_version
129 const char *name;
130 ElfW(Word) hash;
132 int hidden;
133 const char *filename;
136 /* We want to cache information about the searches for shared objects. */
138 enum r_dir_status { unknown, nonexisting, existing };
140 struct r_search_path_elem
142 /* This link is only used in the `all_dirs' member of `r_search_path'. */
143 struct r_search_path_elem *next;
145 /* Strings saying where the definition came from. */
146 const char *what;
147 const char *where;
149 /* Basename for this search path element. The string must end with
150 a slash character. */
151 const char *dirname;
152 size_t dirnamelen;
154 enum r_dir_status status[0];
157 struct r_strlenpair
159 const char *str;
160 size_t len;
164 /* A data structure for a simple single linked list of strings. */
165 struct libname_list
167 const char *name; /* Name requested (before search). */
168 struct libname_list *next; /* Link to next name for this object. */
169 int dont_free; /* Flag whether this element should be freed
170 if the object is not entirely unloaded. */
174 /* Bit masks for the objects which valid callers can come from to
175 functions with restricted interface. */
176 enum allowmask
178 allow_libc = 1,
179 allow_libdl = 2,
180 allow_libpthread = 4,
181 allow_ldso = 8
185 /* Type for list of auditing interfaces. */
186 struct La_i86_regs;
187 struct La_i86_retval;
188 struct La_x86_64_regs;
189 struct La_x86_64_retval;
190 struct La_ppc32_regs;
191 struct La_ppc32_retval;
192 struct La_ppc64_regs;
193 struct La_ppc64_retval;
194 struct La_sh_regs;
195 struct La_sh_retval;
196 struct La_alpha_regs;
197 struct La_alpha_retval;
198 struct La_s390_32_regs;
199 struct La_s390_32_retval;
200 struct La_s390_64_regs;
201 struct La_s390_64_retval;
202 struct La_ia64_regs;
203 struct La_ia64_retval;
204 struct La_sparc32_regs;
205 struct La_sparc32_retval;
206 struct La_sparc64_regs;
207 struct La_sparc64_retval;
209 struct audit_ifaces
211 void (*activity) (uintptr_t *, unsigned int);
212 char *(*objsearch) (const char *, uintptr_t *, unsigned int);
213 unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
214 void (*preinit) (uintptr_t *);
215 union
217 uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
218 uintptr_t *, unsigned int *, const char *);
219 uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
220 uintptr_t *, unsigned int *, const char *);
222 union
224 Elf32_Addr (*i86_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *,
225 uintptr_t *, struct La_i86_regs *,
226 unsigned int *, const char *name,
227 long int *framesizep);
228 Elf64_Addr (*x86_64_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *,
229 uintptr_t *, struct La_x86_64_regs *,
230 unsigned int *, const char *name,
231 long int *framesizep);
232 Elf32_Addr (*ppc32_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *,
233 uintptr_t *, struct La_ppc32_regs *,
234 unsigned int *, const char *name,
235 long int *framesizep);
236 Elf64_Addr (*ppc64_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *,
237 uintptr_t *, struct La_ppc64_regs *,
238 unsigned int *, const char *name,
239 long int *framesizep);
240 uintptr_t (*sh_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *,
241 uintptr_t *, const struct La_sh_regs *,
242 unsigned int *, const char *name,
243 long int *framesizep);
244 Elf64_Addr (*alpha_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *,
245 uintptr_t *, struct La_alpha_regs *,
246 unsigned int *, const char *name,
247 long int *framesizep);
248 Elf32_Addr (*s390_32_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *,
249 uintptr_t *, struct La_s390_32_regs *,
250 unsigned int *, const char *name,
251 long int *framesizep);
252 Elf64_Addr (*s390_64_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *,
253 uintptr_t *, struct La_s390_64_regs *,
254 unsigned int *, const char *name,
255 long int *framesizep);
256 Elf64_Addr (*ia64_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *,
257 uintptr_t *, struct La_ia64_regs *,
258 unsigned int *, const char *name,
259 long int *framesizep);
260 Elf32_Addr (*sparc32_gnu_pltenter) (Elf32_Sym *, unsigned int,
261 uintptr_t *, uintptr_t *,
262 const struct La_sparc32_regs *,
263 unsigned int *, const char *name,
264 long int *framesizep);
265 Elf64_Addr (*sparc64_gnu_pltenter) (Elf64_Sym *, unsigned int,
266 uintptr_t *, uintptr_t *,
267 const struct La_sparc64_regs *,
268 unsigned int *, const char *name,
269 long int *framesizep);
270 #ifdef ARCH_PLTENTER_MEMBERS
271 ARCH_PLTENTER_MEMBERS;
272 #endif
274 union
276 unsigned int (*i86_gnu_pltexit) (Elf32_Sym *, unsigned int, uintptr_t *,
277 uintptr_t *, const struct La_i86_regs *,
278 struct La_i86_retval *, const char *);
279 unsigned int (*x86_64_gnu_pltexit) (Elf64_Sym *, unsigned int, uintptr_t *,
280 uintptr_t *,
281 const struct La_x86_64_regs *,
282 struct La_x86_64_retval *,
283 const char *);
284 unsigned int (*ppc32_gnu_pltexit) (Elf32_Sym *, unsigned int, uintptr_t *,
285 uintptr_t *,
286 const struct La_ppc32_regs *,
287 struct La_ppc32_retval *, const char *);
288 unsigned int (*ppc64_gnu_pltexit) (Elf64_Sym *, unsigned int, uintptr_t *,
289 uintptr_t *,
290 const struct La_ppc64_regs *,
291 struct La_ppc64_retval *, const char *);
292 unsigned int (*sh_gnu_pltexit) (Elf32_Sym *, unsigned int, uintptr_t *,
293 uintptr_t *, const struct La_sh_regs *,
294 struct La_sh_retval *, const char *);
295 unsigned int (*alpha_gnu_pltexit) (Elf64_Sym *, unsigned int, uintptr_t *,
296 uintptr_t *,
297 const struct La_alpha_regs *,
298 struct La_alpha_retval *, const char *);
299 unsigned int (*s390_32_gnu_pltexit) (Elf32_Sym *, unsigned int,
300 uintptr_t *, uintptr_t *,
301 const struct La_s390_32_regs *,
302 struct La_s390_32_retval *,
303 const char *);
304 unsigned int (*s390_64_gnu_pltexit) (Elf64_Sym *, unsigned int,
305 uintptr_t *, uintptr_t *,
306 const struct La_s390_64_regs *,
307 struct La_s390_64_retval *,
308 const char *);
309 unsigned int (*ia64_gnu_pltexit) (Elf64_Sym *, unsigned int, uintptr_t *,
310 uintptr_t *,
311 const struct La_ia64_regs *,
312 struct La_ia64_retval *, const char *);
313 unsigned int (*sparc32_gnu_pltexit) (Elf32_Sym *, unsigned int,
314 uintptr_t *, uintptr_t *,
315 const struct La_sparc32_regs *,
316 struct La_sparc32_retval *,
317 const char *);
318 unsigned int (*sparc64_gnu_pltexit) (Elf64_Sym *, unsigned int,
319 uintptr_t *, uintptr_t *,
320 const struct La_sparc32_regs *,
321 struct La_sparc32_retval *,
322 const char *);
323 #ifdef ARCH_PLTEXIT_MEMBERS
324 ARCH_PLTEXIT_MEMBERS;
325 #endif
327 unsigned int (*objclose) (uintptr_t *);
329 struct audit_ifaces *next;
333 /* Test whether given NAME matches any of the names of the given object. */
334 extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
335 internal_function;
337 /* Function used as argument for `_dl_receive_error' function. The
338 arguments are the error code, error string, and the objname the
339 error occurred in. */
340 typedef void (*receiver_fct) (int, const char *, const char *);
342 /* Internal functions of the run-time dynamic linker.
343 These can be accessed if you link again the dynamic linker
344 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
345 but are not normally of interest to user programs.
347 The `-ldl' library functions in <dlfcn.h> provide a simple
348 user interface to run-time dynamic linking. */
351 #ifndef SHARED
352 # define EXTERN extern
353 # define GL(name) _##name
354 #else
355 # define EXTERN
356 # ifdef IS_IN_rtld
357 # define GL(name) _rtld_local._##name
358 # else
359 # define GL(name) _rtld_global._##name
360 # endif
361 struct rtld_global
363 #endif
364 /* Don't change the order of the following elements. 'dl_loaded'
365 must remain the first element. Forever. */
367 /* Non-shared code has no support for multiple namespaces. */
368 #ifdef SHARED
369 # define DL_NNS 16
370 #else
371 # define DL_NNS 1
372 #endif
373 EXTERN struct link_namespaces
375 /* A pointer to the map for the main map. */
376 struct link_map *_ns_loaded;
377 /* Number of object in the _dl_loaded list. */
378 unsigned int _ns_nloaded;
379 /* Array representing global scope. */
380 struct r_scope_elem *_ns_global_scope[2];
381 /* Direct pointer to the searchlist of the main object. */
382 struct r_scope_elem *_ns_main_searchlist;
383 /* This is zero at program start to signal that the global scope map is
384 allocated by rtld. Later it keeps the size of the map. It might be
385 reset if in _dl_close if the last global object is removed. */
386 size_t _ns_global_scope_alloc;
387 /* Keep track of changes to each namespace' list. */
388 struct r_debug _ns_debug;
389 } _dl_ns[DL_NNS];
391 /* During the program run we must not modify the global data of
392 loaded shared object simultanously in two threads. Therefore we
393 protect `_dl_open' and `_dl_close' in dl-close.c.
395 This must be a recursive lock since the initializer function of
396 the loaded object might as well require a call to this function.
397 At this time it is not anymore a problem to modify the tables. */
398 __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
400 /* Incremented whenever something may have been added to dl_loaded. */
401 EXTERN unsigned long long _dl_load_adds;
403 #ifndef MAP_ANON
404 /* File descriptor referring to the zero-fill device. */
405 EXTERN int _dl_zerofd;
406 #endif
408 /* The object to be initialized first. */
409 EXTERN struct link_map *_dl_initfirst;
411 #if HP_TIMING_AVAIL || HP_SMALL_TIMING_AVAIL
412 /* Start time on CPU clock. */
413 EXTERN hp_timing_t _dl_cpuclock_offset;
414 #endif
416 /* Map of shared object to be profiled. */
417 EXTERN struct link_map *_dl_profile_map;
419 /* Counters for the number of relocations performed. */
420 EXTERN unsigned long int _dl_num_relocations;
421 EXTERN unsigned long int _dl_num_cache_relocations;
423 /* List of search directories. */
424 EXTERN struct r_search_path_elem *_dl_all_dirs;
426 #ifdef _LIBC_REENTRANT
427 EXTERN void **(*_dl_error_catch_tsd) (void) __attribute__ ((const));
428 #endif
430 /* Structure describing the dynamic linker itself. We need to
431 reserve memory for the data the audit libraries need. */
432 EXTERN struct link_map _dl_rtld_map;
433 #ifdef SHARED
434 struct auditstate audit_data[DL_NNS];
435 #endif
437 #if defined SHARED && defined _LIBC_REENTRANT \
438 && defined __rtld_lock_default_lock_recursive
439 EXTERN void (*_dl_rtld_lock_recursive) (void *);
440 EXTERN void (*_dl_rtld_unlock_recursive) (void *);
441 #endif
443 /* Prevailing state of the stack, PF_X indicating it's executable. */
444 EXTERN ElfW(Word) _dl_stack_flags;
446 /* If loading a shared object requires that we make the stack executable
447 when it was not, we do it by calling this function.
448 It returns an errno code or zero on success. */
449 EXTERN int (*_dl_make_stack_executable_hook) (void **) internal_function;
451 /* Keep the conditional TLS members at the end so the layout of the
452 structure used by !USE_TLS code matches the prefix of the layout in
453 the USE_TLS rtld. Note that `struct link_map' is conditionally
454 defined as well, so _dl_rtld_map needs to be last before this. */
455 #ifdef USE_TLS
456 /* Highest dtv index currently needed. */
457 EXTERN size_t _dl_tls_max_dtv_idx;
458 /* Flag signalling whether there are gaps in the module ID allocation. */
459 EXTERN bool _dl_tls_dtv_gaps;
460 /* Information about the dtv slots. */
461 EXTERN struct dtv_slotinfo_list
463 size_t len;
464 struct dtv_slotinfo_list *next;
465 struct dtv_slotinfo
467 size_t gen;
468 struct link_map *map;
469 } slotinfo[0];
470 } *_dl_tls_dtv_slotinfo_list;
471 /* Number of modules in the static TLS block. */
472 EXTERN size_t _dl_tls_static_nelem;
473 /* Size of the static TLS block. */
474 EXTERN size_t _dl_tls_static_size;
475 /* Size actually allocated in the static TLS block. */
476 EXTERN size_t _dl_tls_static_used;
477 /* Alignment requirement of the static TLS block. */
478 EXTERN size_t _dl_tls_static_align;
480 /* Number of additional entries in the slotinfo array of each slotinfo
481 list element. A large number makes it almost certain take we never
482 have to iterate beyond the first element in the slotinfo list. */
483 # define TLS_SLOTINFO_SURPLUS (62)
485 /* Number of additional slots in the dtv allocated. */
486 # define DTV_SURPLUS (14)
488 /* Initial dtv of the main thread, not allocated with normal malloc. */
489 EXTERN void *_dl_initial_dtv;
490 /* Generation counter for the dtv. */
491 EXTERN size_t _dl_tls_generation;
493 EXTERN void (*_dl_init_static_tls) (struct link_map *);
494 #endif
496 #ifdef SHARED
498 # define __rtld_global_attribute__
499 # ifdef IS_IN_rtld
500 # ifdef HAVE_VISIBILITY_ATTRIBUTE
501 # ifdef HAVE_SDATA_SECTION
502 # define __rtld_local_attribute__ \
503 __attribute__ ((visibility ("hidden"), section (".sdata")))
504 # undef __rtld_global_attribute__
505 # define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
506 # else
507 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
508 # endif
509 # else
510 # define __rtld_local_attribute__
511 # endif
512 extern struct rtld_global _rtld_local __rtld_local_attribute__;
513 # undef __rtld_local_attribute__
514 # endif
515 extern struct rtld_global _rtld_global __rtld_global_attribute__;
516 # undef __rtld_global_attribute__
517 #endif
519 #ifndef SHARED
520 # define GLRO(name) _##name
521 #else
522 # ifdef IS_IN_rtld
523 # define GLRO(name) _rtld_local_ro._##name
524 # else
525 # define GLRO(name) _rtld_global_ro._##name
526 # endif
527 struct rtld_global_ro
529 #endif
531 /* If nonzero the appropriate debug information is printed. */
532 EXTERN int _dl_debug_mask;
533 #define DL_DEBUG_LIBS (1 << 0)
534 #define DL_DEBUG_IMPCALLS (1 << 1)
535 #define DL_DEBUG_BINDINGS (1 << 2)
536 #define DL_DEBUG_SYMBOLS (1 << 3)
537 #define DL_DEBUG_VERSIONS (1 << 4)
538 #define DL_DEBUG_RELOC (1 << 5)
539 #define DL_DEBUG_FILES (1 << 6)
540 #define DL_DEBUG_STATISTICS (1 << 7)
541 #define DL_DEBUG_UNUSED (1 << 8)
542 /* These two are used only internally. */
543 #define DL_DEBUG_HELP (1 << 9)
544 #define DL_DEBUG_PRELINK (1 << 10)
546 /* Cached value of `getpagesize ()'. */
547 EXTERN size_t _dl_pagesize;
549 /* OS version. */
550 EXTERN unsigned int _dl_osversion;
551 /* Platform name. */
552 EXTERN const char *_dl_platform;
553 EXTERN size_t _dl_platformlen;
555 /* Copy of the content of `_dl_main_searchlist' at startup time. */
556 EXTERN struct r_scope_elem _dl_initial_searchlist;
558 /* CLK_TCK as reported by the kernel. */
559 EXTERN int _dl_clktck;
561 /* If nonzero print warnings messages. */
562 EXTERN int _dl_verbose;
564 /* File descriptor to write debug messages to. */
565 EXTERN int _dl_debug_fd;
567 /* Do we do lazy relocations? */
568 EXTERN int _dl_lazy;
570 /* Nonzero if runtime lookups should not update the .got/.plt. */
571 EXTERN int _dl_bind_not;
573 /* Nonzero if references should be treated as weak during runtime
574 linking. */
575 EXTERN int _dl_dynamic_weak;
577 /* Default floating-point control word. */
578 EXTERN fpu_control_t _dl_fpu_control;
580 /* Expected cache ID. */
581 EXTERN int _dl_correct_cache_id;
583 /* 0 if internal pointer values should not be guarded, 1 if they should. */
584 EXTERN int _dl_pointer_guard;
586 /* Mask for hardware capabilities that are available. */
587 EXTERN uint64_t _dl_hwcap;
589 /* Mask for important hardware capabilities we honour. */
590 EXTERN uint64_t _dl_hwcap_mask;
592 /* Get architecture specific definitions. */
593 #define PROCINFO_DECL
594 #ifndef PROCINFO_CLASS
595 # define PROCINFO_CLASS EXTERN
596 #endif
597 #include <dl-procinfo.c>
599 /* Names of shared object for which the RPATH should be ignored. */
600 EXTERN const char *_dl_inhibit_rpath;
602 /* Location of the binary. */
603 EXTERN const char *_dl_origin_path;
605 /* -1 if the dynamic linker should honor library load bias,
606 0 if not, -2 use the default (honor biases for normal
607 binaries, don't honor for PIEs). */
608 EXTERN ElfW(Addr) _dl_use_load_bias;
610 /* Name of the shared object to be profiled (if any). */
611 EXTERN const char *_dl_profile;
612 /* Filename of the output file. */
613 EXTERN const char *_dl_profile_output;
614 /* Name of the object we want to trace the prelinking. */
615 EXTERN const char *_dl_trace_prelink;
616 /* Map of shared object to be prelink traced. */
617 EXTERN struct link_map *_dl_trace_prelink_map;
619 /* All search directories defined at startup. */
620 EXTERN struct r_search_path_elem *_dl_init_all_dirs;
622 #if HP_TIMING_AVAIL || HP_SMALL_TIMING_AVAIL
623 /* Overhead of a high-precision timing measurement. */
624 EXTERN hp_timing_t _dl_hp_timing_overhead;
625 #endif
627 #ifdef NEED_DL_SYSINFO
628 /* Syscall handling improvements. This is very specific to x86. */
629 EXTERN uintptr_t _dl_sysinfo;
630 #endif
632 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
633 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
634 This points to its ELF header. */
635 EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
637 /* At startup time we set up the normal DSO data structure for it,
638 and this points to it. */
639 EXTERN struct link_map *_dl_sysinfo_map;
640 #endif
642 #ifdef SHARED
643 /* We add a function table to _rtld_global which is then used to
644 call the function instead of going through the PLT. The result
645 is that we can avoid exporting the functions and we do not jump
646 PLT relocations in libc.so. */
647 void (*_dl_debug_printf) (const char *, ...)
648 __attribute__ ((__format__ (__printf__, 1, 2)));
649 int (internal_function *_dl_catch_error) (const char **, const char **,
650 bool *, void (*) (void *), void *);
651 void (internal_function *_dl_signal_error) (int, const char *, const char *,
652 const char *);
653 void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
654 lookup_t (internal_function *_dl_lookup_symbol_x) (const char *,
655 struct link_map *,
656 const ElfW(Sym) **,
657 struct r_scope_elem *[],
658 const struct r_found_version *,
659 int, int,
660 struct link_map *);
661 int (*_dl_check_caller) (const void *, enum allowmask);
662 void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
663 Lmid_t nsid, int argc, char *argv[], char *env[]);
664 void (*_dl_close) (void *map);
666 /* List of auditing interfaces. */
667 struct audit_ifaces *_dl_audit;
668 unsigned int _dl_naudit;
670 # define __rtld_global_attribute__
671 # ifdef IS_IN_rtld
672 # ifdef HAVE_VISIBILITY_ATTRIBUTE
673 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
674 # else
675 # define __rtld_local_attribute__
676 # endif
677 extern struct rtld_global_ro _rtld_local_ro
678 attribute_relro __rtld_local_attribute__;
679 extern struct rtld_global_ro _rtld_global_ro
680 attribute_relro __rtld_global_attribute__;
681 # undef __rtld_local_attribute__
682 # else
683 /* We cheat a bit here. We declare the variable as as const even
684 though it is at startup. */
685 extern const struct rtld_global_ro _rtld_global_ro
686 attribute_relro __rtld_global_attribute__;
687 # endif
688 # undef __rtld_global_attribute__
689 #endif
690 #undef EXTERN
692 #ifdef IS_IN_rtld
693 /* This is the initial value of GL(dl_error_catch_tsd).
694 A non-TLS libpthread will change it. */
695 extern void **_dl_initial_error_catch_tsd (void) __attribute__ ((const))
696 attribute_hidden;
697 #endif
699 /* This is the initial value of GL(dl_make_stack_executable_hook).
700 A threads library can change it. */
701 extern int _dl_make_stack_executable (void **stack_endp) internal_function;
702 rtld_hidden_proto (_dl_make_stack_executable)
704 /* Variable pointing to the end of the stack (or close to it). This value
705 must be constant over the runtime of the application. Some programs
706 might use the variable which results in copy relocations on some
707 platforms. But this does not matter, ld.so can always use the local
708 copy. */
709 extern void *__libc_stack_end attribute_relro;
710 rtld_hidden_proto (__libc_stack_end)
712 /* Parameters passed to the dynamic linker. */
713 extern int _dl_argc attribute_hidden attribute_relro;
714 extern char **_dl_argv
715 #ifndef DL_ARGV_NOT_RELRO
716 attribute_relro
717 #endif
719 #ifdef IS_IN_rtld
720 extern char **_dl_argv_internal attribute_hidden
721 # ifndef DL_ARGV_NOT_RELRO
722 attribute_relro
723 # endif
725 # define rtld_progname (INTUSE(_dl_argv)[0])
726 #else
727 # define rtld_progname _dl_argv[0]
728 #endif
730 /* Flag set at startup and cleared when the last initializer has run. */
731 extern int _dl_starting_up;
732 weak_extern (_dl_starting_up)
733 #ifdef IS_IN_rtld
734 extern int _dl_starting_up_internal attribute_hidden;
735 #endif
737 /* OS-dependent function to open the zero-fill device. */
738 extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
741 /* Write message on the debug file descriptor. The parameters are
742 interpreted as for a `printf' call. All the lines start with a
743 tag showing the PID. */
744 extern void _dl_debug_printf (const char *fmt, ...)
745 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
747 /* Write message on the debug file descriptor. The parameters are
748 interpreted as for a `printf' call. All the lines buf the first
749 start with a tag showing the PID. */
750 extern void _dl_debug_printf_c (const char *fmt, ...)
751 __attribute__ ((__format__ (__printf__, 1, 2)));
754 /* Write a message on the specified descriptor FD. The parameters are
755 interpreted as for a `printf' call. */
756 extern void _dl_dprintf (int fd, const char *fmt, ...)
757 __attribute__ ((__format__ (__printf__, 2, 3)))
758 attribute_hidden;
760 /* Write a message on the specified descriptor standard output. The
761 parameters are interpreted as for a `printf' call. */
762 #define _dl_printf(fmt, args...) \
763 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
765 /* Write a message on the specified descriptor standard error. The
766 parameters are interpreted as for a `printf' call. */
767 #define _dl_error_printf(fmt, args...) \
768 _dl_dprintf (STDERR_FILENO, fmt, ##args)
770 /* Write a message on the specified descriptor standard error and exit
771 the program. The parameters are interpreted as for a `printf' call. */
772 #define _dl_fatal_printf(fmt, args...) \
773 do \
775 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
776 _exit (127); \
778 while (1)
781 /* This function is called by all the internal dynamic linker functions
782 when they encounter an error. ERRCODE is either an `errno' code or
783 zero; OBJECT is the name of the problematical shared object, or null if
784 it is a general problem; ERRSTRING is a string describing the specific
785 problem. */
786 extern void _dl_signal_error (int errcode, const char *object,
787 const char *occurred, const char *errstring)
788 internal_function __attribute__ ((__noreturn__)) attribute_hidden;
790 /* Like _dl_signal_error, but may return when called in the context of
791 _dl_receive_error. */
792 extern void _dl_signal_cerror (int errcode, const char *object,
793 const char *occation, const char *errstring)
794 internal_function;
796 /* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
797 `_dl_catch_error' the operation is resumed after the OPERATE
798 function returns.
799 ARGS is passed as argument to OPERATE. */
800 extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
801 void *args)
802 internal_function;
805 /* Open the shared object NAME and map in its segments.
806 LOADER's DT_RPATH is used in searching for NAME.
807 If the object is already opened, returns its existing map.
808 For preloaded shared objects PRELOADED is set to a non-zero
809 value to allow additional security checks. */
810 extern struct link_map *_dl_map_object (struct link_map *loader,
811 const char *name, int preloaded,
812 int type, int trace_mode, int mode,
813 Lmid_t nsid)
814 internal_function attribute_hidden;
816 /* Call _dl_map_object on the dependencies of MAP, and set up
817 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
818 loaded objects that will be inserted into MAP->l_searchlist after MAP
819 but before its dependencies. */
820 extern void _dl_map_object_deps (struct link_map *map,
821 struct link_map **preloads,
822 unsigned int npreloads, int trace_mode,
823 int open_mode)
824 internal_function attribute_hidden;
826 /* Cache the locations of MAP's hash table. */
827 extern void _dl_setup_hash (struct link_map *map)
828 internal_function attribute_hidden;
831 /* Collect the directories in the search path for LOADER's dependencies.
832 The data structure is defined in <dlfcn.h>. If COUNTING is true,
833 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
834 by a previous call with COUNTING set, and SI must point to SI->dls_size
835 bytes to be used in filling in the result. */
836 extern void _dl_rtld_di_serinfo (struct link_map *loader,
837 Dl_serinfo *si, bool counting)
838 internal_function;
841 /* Search loaded objects' symbol tables for a definition of the symbol
842 referred to by UNDEF. *SYM is the symbol table entry containing the
843 reference; it is replaced with the defining symbol, and the base load
844 address of the defining object is returned. SYMBOL_SCOPE is a
845 null-terminated list of object scopes to search; each object's
846 l_searchlist (i.e. the segment of the dependency tree starting at that
847 object) is searched in turn. REFERENCE_NAME should name the object
848 containing the reference; it is used in error messages.
849 TYPE_CLASS describes the type of symbol we are looking for. */
850 enum
852 /* If necessary add dependency between user and provider object. */
853 DL_LOOKUP_ADD_DEPENDENCY = 1,
854 /* Return most recent version instead of default version for
855 unversioned lookup. */
856 DL_LOOKUP_RETURN_NEWEST = 2
859 /* Lookup versioned symbol. */
860 extern lookup_t _dl_lookup_symbol_x (const char *undef,
861 struct link_map *undef_map,
862 const ElfW(Sym) **sym,
863 struct r_scope_elem *symbol_scope[],
864 const struct r_found_version *version,
865 int type_class, int explicit,
866 struct link_map *skip_map)
867 internal_function attribute_hidden;
870 /* Look up symbol NAME in MAP's scope and return its run-time address. */
871 extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name)
872 internal_function;
874 /* Allocate a `struct link_map' for a new object being loaded,
875 and enter it into the _dl_main_map list. */
876 extern struct link_map *_dl_new_object (char *realname, const char *libname,
877 int type, struct link_map *loader,
878 int mode, Lmid_t nsid)
879 internal_function attribute_hidden;
881 /* Relocate the given object (if it hasn't already been).
882 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
883 If LAZY is nonzero, don't relocate its PLT. */
884 extern void _dl_relocate_object (struct link_map *map,
885 struct r_scope_elem *scope[],
886 int lazy, int consider_profiling)
887 attribute_hidden;
889 /* Protect PT_GNU_RELRO area. */
890 extern void _dl_protect_relro (struct link_map *map)
891 internal_function attribute_hidden;
893 /* Call _dl_signal_error with a message about an unhandled reloc type.
894 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
895 PLT is nonzero if this was a PLT reloc; it just affects the message. */
896 extern void _dl_reloc_bad_type (struct link_map *map,
897 unsigned int type, int plt)
898 internal_function __attribute__ ((__noreturn__));
900 /* Resolve conflicts if prelinking. */
901 extern void _dl_resolve_conflicts (struct link_map *l,
902 ElfW(Rela) *conflict,
903 ElfW(Rela) *conflictend);
905 /* Check the version dependencies of all objects available through
906 MAP. If VERBOSE print some more diagnostics. */
907 extern int _dl_check_all_versions (struct link_map *map, int verbose,
908 int trace_mode)
909 internal_function;
911 /* Check the version dependencies for MAP. If VERBOSE print some more
912 diagnostics. */
913 extern int _dl_check_map_versions (struct link_map *map, int verbose,
914 int trace_mode)
915 internal_function;
917 /* Initialize the object in SCOPE by calling the constructors with
918 ARGC, ARGV, and ENV as the parameters. */
919 extern void _dl_init (struct link_map *main_map, int argc, char **argv,
920 char **env) internal_function attribute_hidden;
922 /* Call the finalizer functions of all shared objects whose
923 initializer functions have completed. */
924 extern void _dl_fini (void) internal_function;
926 /* Sort array MAPS according to dependencies of the contained objects. */
927 extern void _dl_sort_fini (struct link_map *l, struct link_map **maps,
928 size_t nmaps, char *used, Lmid_t ns)
929 internal_function;
931 /* The dynamic linker calls this function before and having changing
932 any shared object mappings. The `r_state' member of `struct r_debug'
933 says what change is taking place. This function's address is
934 the value of the `r_brk' member. */
935 extern void _dl_debug_state (void);
936 rtld_hidden_proto (_dl_debug_state)
938 /* Initialize `struct r_debug' if it has not already been done. The
939 argument is the run-time load address of the dynamic linker, to be put
940 in the `r_ldbase' member. Returns the address of the structure. */
941 extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
942 internal_function;
944 /* Initialize the basic data structure for the search paths. */
945 extern void _dl_init_paths (const char *library_path) internal_function;
947 /* Gather the information needed to install the profiling tables and start
948 the timers. */
949 extern void _dl_start_profile (void) internal_function attribute_hidden;
951 /* The actual functions used to keep book on the calls. */
952 extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
953 extern void _dl_mcount_internal (ElfW(Addr) frompc, ElfW(Addr) selfpc)
954 attribute_hidden;
956 /* This function is simply a wrapper around the _dl_mcount function
957 which does not require a FROMPC parameter since this is the
958 calling function. */
959 extern void _dl_mcount_wrapper (void *selfpc);
961 /* Show the members of the auxiliary array passed up from the kernel. */
962 extern void _dl_show_auxv (void) internal_function;
964 /* Return all environment variables starting with `LD_', one after the
965 other. */
966 extern char *_dl_next_ld_env_entry (char ***position) internal_function;
968 /* Return an array with the names of the important hardware capabilities. */
969 extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform,
970 size_t paltform_len,
971 size_t *sz,
972 size_t *max_capstrlen)
973 internal_function;
975 /* Look up NAME in ld.so.cache and return the file name stored there,
976 or null if none is found. */
977 extern const char *_dl_load_cache_lookup (const char *name)
978 internal_function;
980 /* If the system does not support MAP_COPY we cannot leave the file open
981 all the time since this would create problems when the file is replaced.
982 Therefore we provide this function to close the file and open it again
983 once needed. */
984 extern void _dl_unload_cache (void) attribute_hidden;
986 /* System-dependent function to read a file's whole contents in the
987 most convenient manner available. *SIZEP gets the size of the
988 file. On error MAP_FAILED is returned. */
989 extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
990 int prot)
991 internal_function attribute_hidden;
993 /* System-specific function to do initial startup for the dynamic linker.
994 After this, file access calls and getenv must work. This is responsible
995 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
996 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
997 extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
998 void (*dl_main) (const ElfW(Phdr) *phdr,
999 ElfW(Word) phnum,
1000 ElfW(Addr) *user_entry))
1001 attribute_hidden;
1003 extern void _dl_sysdep_start_cleanup (void)
1004 internal_function attribute_hidden;
1007 /* Determine next available module ID. */
1008 extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden;
1010 /* Calculate offset of the TLS blocks in the static TLS block. */
1011 extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden;
1013 /* Set up the data structures for TLS, when they were not set up at startup.
1014 Returns nonzero on malloc failure.
1015 This is called from _dl_map_object_from_fd or by libpthread. */
1016 extern int _dl_tls_setup (void) internal_function;
1017 rtld_hidden_proto (_dl_tls_setup)
1019 /* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
1020 extern void *_dl_allocate_tls (void *mem) internal_function;
1021 rtld_hidden_proto (_dl_allocate_tls)
1023 /* Get size and alignment requirements of the static TLS block. */
1024 extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp)
1025 internal_function;
1027 extern void _dl_allocate_static_tls (struct link_map *map)
1028 internal_function attribute_hidden;
1030 /* These are internal entry points to the two halves of _dl_allocate_tls,
1031 only used within rtld.c itself at startup time. */
1032 extern void *_dl_allocate_tls_storage (void)
1033 internal_function attribute_hidden;
1034 extern void *_dl_allocate_tls_init (void *) internal_function;
1035 rtld_hidden_proto (_dl_allocate_tls_init)
1037 /* Deallocate memory allocated with _dl_allocate_tls. */
1038 extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb) internal_function;
1039 rtld_hidden_proto (_dl_deallocate_tls)
1041 #if defined USE_TLS
1042 extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
1043 #endif
1045 /* Find origin of the executable. */
1046 extern const char *_dl_get_origin (void) attribute_hidden;
1048 /* Count DSTs. */
1049 extern size_t _dl_dst_count (const char *name, int is_path) attribute_hidden;
1051 /* Substitute DST values. */
1052 extern char *_dl_dst_substitute (struct link_map *l, const char *name,
1053 char *result, int is_path) attribute_hidden;
1055 /* Check validity of the caller. */
1056 extern int _dl_check_caller (const void *caller, enum allowmask mask)
1057 attribute_hidden;
1059 /* Open the shared object NAME, relocate it, and run its initializer if it
1060 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1061 the object is already opened, returns its existing map. */
1062 extern void *_dl_open (const char *name, int mode, const void *caller,
1063 Lmid_t nsid, int argc, char *argv[], char *env[])
1064 attribute_hidden;
1066 /* Add module to slot information data. */
1067 extern void _dl_add_to_slotinfo (struct link_map *l) attribute_hidden;
1069 /* Update slot information data for at least the generation of the
1070 module with the given index. */
1071 extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid);
1073 /* Look up the module's TLS block as for __tls_get_addr,
1074 but never touch anything. Return null if it's not allocated yet. */
1075 extern void *_dl_tls_get_addr_soft (struct link_map *l) internal_function;
1078 __END_DECLS
1080 #endif /* ldsodefs.h */