1 /* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2013 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, see
17 <http://www.gnu.org/licenses/>. */
33 #include <fpu_control.h>
36 #include <dl-lookupcfg.h>
37 #include <dl-sysdep.h>
38 #include <bits/libc-lock.h>
39 #include <hp-timing.h>
41 #include <kernel-features.h>
45 #define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
46 #define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
47 + DT_EXTRANUM + DT_VALTAGIDX (tag))
48 #define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
49 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
51 /* We use this macro to refer to ELF types independent of the native wordsize.
52 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
53 #define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
55 /* All references to the value of l_info[DT_PLTGOT],
56 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
57 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
58 have to be accessed via the D_PTR macro. The macro is needed since for
59 most architectures the entry is already relocated - but for some not
60 and we need to relocate at access time. */
61 #ifdef DL_RO_DYN_SECTION
62 # define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
64 # define D_PTR(map, i) (map)->i->d_un.d_ptr
67 /* Result of the lookup functions and how to retrieve the base address. */
68 typedef struct link_map
*lookup_t
;
69 #define LOOKUP_VALUE(map) map
70 #define LOOKUP_VALUE_ADDRESS(map) ((map) ? (map)->l_addr : 0)
72 /* On some architectures a pointer to a function is not just a pointer
73 to the actual code of the function but rather an architecture
74 specific descriptor. */
75 #ifndef ELF_FUNCTION_PTR_IS_SPECIAL
76 # define DL_SYMBOL_ADDRESS(map, ref) \
77 (void *) (LOOKUP_VALUE_ADDRESS (map) + ref->st_value)
78 # define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
79 # define DL_CALL_DT_INIT(map, start, argc, argv, env) \
80 ((init_t) (start)) (argc, argv, env)
81 # define DL_CALL_DT_FINI(map, start) ((fini_t) (start)) ()
84 /* On some architectures dladdr can't use st_size of all symbols this way. */
85 #define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
86 ((ADDR) >= (L)->l_addr + (SYM)->st_value \
87 && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
88 && (ADDR) == (L)->l_addr + (SYM)->st_value) \
89 || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
90 && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
92 /* Unmap a loaded object, called by _dl_close (). */
93 #ifndef DL_UNMAP_IS_SPECIAL
94 # define DL_UNMAP(map) \
95 __munmap ((void *) (map)->l_map_start, \
96 (map)->l_map_end - (map)->l_map_start)
99 /* By default we do not need special support to initialize DSOs loaded
100 by statically linked binaries. */
101 #ifndef DL_STATIC_INIT
102 # define DL_STATIC_INIT(map)
105 /* Reloc type classes as returned by elf_machine_type_class().
106 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
107 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
108 satisfied by any symbol in the executable. Some architectures do
109 not support copy relocations. In this case we define the macro to
110 zero so that the code for handling them gets automatically optimized
112 #define ELF_RTYPE_CLASS_PLT 1
113 #ifndef DL_NO_COPY_RELOCS
114 # define ELF_RTYPE_CLASS_COPY 2
116 # define ELF_RTYPE_CLASS_COPY 0
119 /* ELF uses the PF_x macros to specify the segment permissions, mmap
120 uses PROT_xxx. In most cases the three macros have the values 1, 2,
121 and 3 but not in a matching order. The following macros allows
122 converting from the PF_x values to PROT_xxx values. */
124 ((PROT_READ << (PF_R * 4)) \
125 | (PROT_WRITE << (PF_W * 4)) \
126 | (PROT_EXEC << (PF_X * 4)) \
127 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
128 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
129 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
130 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
132 /* The filename itself, or the main program name, if available. */
133 #define DSO_FILENAME(name) ((name)[0] ? (name) \
134 : (rtld_progname ?: "<main program>"))
136 #define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
138 /* For the version handling we need an array with only names and their
140 struct r_found_version
146 const char *filename
;
149 /* We want to cache information about the searches for shared objects. */
151 enum r_dir_status
{ unknown
, nonexisting
, existing
};
153 struct r_search_path_elem
155 /* This link is only used in the `all_dirs' member of `r_search_path'. */
156 struct r_search_path_elem
*next
;
158 /* Strings saying where the definition came from. */
162 /* Basename for this search path element. The string must end with
163 a slash character. */
167 enum r_dir_status status
[0];
177 /* A data structure for a simple single linked list of strings. */
180 const char *name
; /* Name requested (before search). */
181 struct libname_list
*next
; /* Link to next name for this object. */
182 int dont_free
; /* Flag whether this element should be freed
183 if the object is not entirely unloaded. */
187 /* Bit masks for the objects which valid callers can come from to
188 functions with restricted interface. */
193 allow_libpthread
= 4,
200 void (*activity
) (uintptr_t *, unsigned int);
201 char *(*objsearch
) (const char *, uintptr_t *, unsigned int);
202 unsigned int (*objopen
) (struct link_map
*, Lmid_t
, uintptr_t *);
203 void (*preinit
) (uintptr_t *);
206 uintptr_t (*symbind32
) (Elf32_Sym
*, unsigned int, uintptr_t *,
207 uintptr_t *, unsigned int *, const char *);
208 uintptr_t (*symbind64
) (Elf64_Sym
*, unsigned int, uintptr_t *,
209 uintptr_t *, unsigned int *, const char *);
213 #ifdef ARCH_PLTENTER_MEMBERS
214 ARCH_PLTENTER_MEMBERS
;
219 #ifdef ARCH_PLTEXIT_MEMBERS
220 ARCH_PLTEXIT_MEMBERS
;
223 unsigned int (*objclose
) (uintptr_t *);
225 struct audit_ifaces
*next
;
229 /* Test whether given NAME matches any of the names of the given object. */
230 extern int _dl_name_match_p (const char *__name
, const struct link_map
*__map
)
233 /* Compute next higher prime number. */
234 extern unsigned long int _dl_higher_prime_number (unsigned long int n
)
237 /* Mask every signal, returning the previous sigmask in OLD. */
238 extern void _dl_mask_all_signals (sigset_t
*old
) internal_function
;
239 /* Undo _dl_mask_all_signals. */
240 extern void _dl_unmask_signals (sigset_t
*old
) internal_function
;
242 /* Function used as argument for `_dl_receive_error' function. The
243 arguments are the error code, error string, and the objname the
244 error occurred in. */
245 typedef void (*receiver_fct
) (int, const char *, const char *);
247 /* Internal functions of the run-time dynamic linker.
248 These can be accessed if you link again the dynamic linker
249 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
250 but are not normally of interest to user programs.
252 The `-ldl' library functions in <dlfcn.h> provide a simple
253 user interface to run-time dynamic linking. */
257 # define EXTERN extern
258 # define GL(name) _##name
262 # define GL(name) _rtld_local._##name
264 # define GL(name) _rtld_global._##name
269 /* Don't change the order of the following elements. 'dl_loaded'
270 must remain the first element. Forever. */
272 /* Non-shared code has no support for multiple namespaces. */
278 EXTERN
struct link_namespaces
280 /* A pointer to the map for the main map. */
281 struct link_map
*_ns_loaded
;
282 /* Number of object in the _dl_loaded list. */
283 unsigned int _ns_nloaded
;
284 /* Direct pointer to the searchlist of the main object. */
285 struct r_scope_elem
*_ns_main_searchlist
;
286 /* This is zero at program start to signal that the global scope map is
287 allocated by rtld. Later it keeps the size of the map. It might be
288 reset if in _dl_close if the last global object is removed. */
289 size_t _ns_global_scope_alloc
;
290 /* Search table for unique objects. */
291 struct unique_sym_table
293 __rtld_lock_define_recursive (, lock
)
298 const ElfW(Sym
) *sym
;
299 const struct link_map
*map
;
303 void (*free
) (void *);
304 } _ns_unique_sym_table
;
305 /* Keep track of changes to each namespace' list. */
306 struct r_debug _ns_debug
;
308 /* One higher than index of last used namespace. */
309 EXTERN
size_t _dl_nns
;
311 /* During the program run we must not modify the global data of
312 loaded shared object simultanously in two threads. Therefore we
313 protect `_dl_open' and `_dl_close' in dl-close.c.
315 This must be a recursive lock since the initializer function of
316 the loaded object might as well require a call to this function.
317 At this time it is not anymore a problem to modify the tables. */
318 __rtld_lock_define_recursive (EXTERN
, _dl_load_lock
)
319 /* This lock is used to keep __dl_iterate_phdr from inspecting the
320 list of loaded objects while an object is added to or removed
322 __rtld_lock_define_recursive (EXTERN
, _dl_load_write_lock
)
324 /* Incremented whenever something may have been added to dl_loaded. */
325 EXTERN
unsigned long long _dl_load_adds
;
327 /* The object to be initialized first. */
328 EXTERN
struct link_map
*_dl_initfirst
;
330 #if HP_TIMING_AVAIL || HP_SMALL_TIMING_AVAIL
331 /* Start time on CPU clock. */
332 EXTERN hp_timing_t _dl_cpuclock_offset
;
335 /* Map of shared object to be profiled. */
336 EXTERN
struct link_map
*_dl_profile_map
;
338 /* Counters for the number of relocations performed. */
339 EXTERN
unsigned long int _dl_num_relocations
;
340 EXTERN
unsigned long int _dl_num_cache_relocations
;
342 /* List of search directories. */
343 EXTERN
struct r_search_path_elem
*_dl_all_dirs
;
345 #ifdef _LIBC_REENTRANT
346 EXTERN
void **(*_dl_error_catch_tsd
) (void) __attribute__ ((const));
349 /* Structure describing the dynamic linker itself. We need to
350 reserve memory for the data the audit libraries need. */
351 EXTERN
struct link_map _dl_rtld_map
;
353 struct auditstate audit_data
[DL_NNS
];
356 #if defined SHARED && defined _LIBC_REENTRANT \
357 && defined __rtld_lock_default_lock_recursive
358 EXTERN
void (*_dl_rtld_lock_recursive
) (void *);
359 EXTERN
void (*_dl_rtld_unlock_recursive
) (void *);
362 /* If loading a shared object requires that we make the stack executable
363 when it was not, we do it by calling this function.
364 It returns an errno code or zero on success. */
365 EXTERN
int (*_dl_make_stack_executable_hook
) (void **) internal_function
;
367 /* Prevailing state of the stack, PF_X indicating it's executable. */
368 EXTERN
ElfW(Word
) _dl_stack_flags
;
370 /* Flag signalling whether there are gaps in the module ID allocation. */
371 EXTERN
bool _dl_tls_dtv_gaps
;
372 /* Highest dtv index currently needed. */
373 EXTERN
size_t _dl_tls_max_dtv_idx
;
374 /* Information about the dtv slots. */
375 EXTERN
struct dtv_slotinfo_list
378 struct dtv_slotinfo_list
*next
;
382 struct link_map
*map
;
384 } *_dl_tls_dtv_slotinfo_list
;
385 /* Number of modules in the static TLS block. */
386 EXTERN
size_t _dl_tls_static_nelem
;
387 /* Size of the static TLS block. */
388 EXTERN
size_t _dl_tls_static_size
;
389 /* Size actually allocated in the static TLS block. */
390 EXTERN
size_t _dl_tls_static_used
;
391 /* Alignment requirement of the static TLS block. */
392 EXTERN
size_t _dl_tls_static_align
;
394 /* Number of additional entries in the slotinfo array of each slotinfo
395 list element. A large number makes it almost certain take we never
396 have to iterate beyond the first element in the slotinfo list. */
397 #define TLS_SLOTINFO_SURPLUS (62)
399 /* Number of additional slots in the dtv allocated. */
400 #define DTV_SURPLUS (14)
402 /* Initial dtv of the main thread, not allocated with normal malloc. */
403 EXTERN
void *_dl_initial_dtv
;
404 /* Generation counter for the dtv. */
405 EXTERN
size_t _dl_tls_generation
;
407 EXTERN
void (*_dl_init_static_tls
) (struct link_map
*);
409 EXTERN
void (*_dl_wait_lookup_done
) (void);
411 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
412 EXTERN
struct dl_scope_free_list
416 } *_dl_scope_free_list
;
419 # define __rtld_global_attribute__
421 # ifdef HAVE_SDATA_SECTION
422 # define __rtld_local_attribute__ \
423 __attribute__ ((visibility ("hidden"), section (".sdata")))
424 # undef __rtld_global_attribute__
425 # define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
427 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
429 extern struct rtld_global _rtld_local __rtld_local_attribute__
;
430 # undef __rtld_local_attribute__
432 extern struct rtld_global _rtld_global __rtld_global_attribute__
;
433 # undef __rtld_global_attribute__
437 # define GLRO(name) _##name
440 # define GLRO(name) _rtld_local_ro._##name
442 # define GLRO(name) _rtld_global_ro._##name
444 struct rtld_global_ro
448 /* If nonzero the appropriate debug information is printed. */
449 EXTERN
int _dl_debug_mask
;
450 #define DL_DEBUG_LIBS (1 << 0)
451 #define DL_DEBUG_IMPCALLS (1 << 1)
452 #define DL_DEBUG_BINDINGS (1 << 2)
453 #define DL_DEBUG_SYMBOLS (1 << 3)
454 #define DL_DEBUG_VERSIONS (1 << 4)
455 #define DL_DEBUG_RELOC (1 << 5)
456 #define DL_DEBUG_FILES (1 << 6)
457 #define DL_DEBUG_STATISTICS (1 << 7)
458 #define DL_DEBUG_UNUSED (1 << 8)
459 #define DL_DEBUG_SCOPES (1 << 9)
460 /* These two are used only internally. */
461 #define DL_DEBUG_HELP (1 << 10)
462 #define DL_DEBUG_PRELINK (1 << 11)
465 EXTERN
unsigned int _dl_osversion
;
467 EXTERN
const char *_dl_platform
;
468 EXTERN
size_t _dl_platformlen
;
470 /* Cached value of `getpagesize ()'. */
471 EXTERN
size_t _dl_pagesize
;
473 /* Do we read from ld.so.cache? */
474 EXTERN
int _dl_inhibit_cache
;
476 /* Copy of the content of `_dl_main_searchlist' at startup time. */
477 EXTERN
struct r_scope_elem _dl_initial_searchlist
;
479 /* CLK_TCK as reported by the kernel. */
480 EXTERN
int _dl_clktck
;
482 /* If nonzero print warnings messages. */
483 EXTERN
int _dl_verbose
;
485 /* File descriptor to write debug messages to. */
486 EXTERN
int _dl_debug_fd
;
488 /* Do we do lazy relocations? */
491 /* Nonzero if runtime lookups should not update the .got/.plt. */
492 EXTERN
int _dl_bind_not
;
494 /* Nonzero if references should be treated as weak during runtime
496 EXTERN
int _dl_dynamic_weak
;
498 /* Default floating-point control word. */
499 EXTERN fpu_control_t _dl_fpu_control
;
501 /* Expected cache ID. */
502 EXTERN
int _dl_correct_cache_id
;
504 /* Mask for hardware capabilities that are available. */
505 EXTERN
uint64_t _dl_hwcap
;
507 /* Mask for important hardware capabilities we honour. */
508 EXTERN
uint64_t _dl_hwcap_mask
;
510 /* Pointer to the auxv list supplied to the program at startup. */
511 EXTERN
ElfW(auxv_t
) *_dl_auxv
;
513 /* Get architecture specific definitions. */
514 #define PROCINFO_DECL
515 #ifndef PROCINFO_CLASS
516 # define PROCINFO_CLASS EXTERN
518 #include <dl-procinfo.c>
520 /* Names of shared object for which the RPATH should be ignored. */
521 EXTERN
const char *_dl_inhibit_rpath
;
523 /* Location of the binary. */
524 EXTERN
const char *_dl_origin_path
;
526 /* -1 if the dynamic linker should honor library load bias,
527 0 if not, -2 use the default (honor biases for normal
528 binaries, don't honor for PIEs). */
529 EXTERN
ElfW(Addr
) _dl_use_load_bias
;
531 /* Name of the shared object to be profiled (if any). */
532 EXTERN
const char *_dl_profile
;
533 /* Filename of the output file. */
534 EXTERN
const char *_dl_profile_output
;
535 /* Name of the object we want to trace the prelinking. */
536 EXTERN
const char *_dl_trace_prelink
;
537 /* Map of shared object to be prelink traced. */
538 EXTERN
struct link_map
*_dl_trace_prelink_map
;
540 /* All search directories defined at startup. */
541 EXTERN
struct r_search_path_elem
*_dl_init_all_dirs
;
543 #if HP_TIMING_AVAIL || HP_SMALL_TIMING_AVAIL
544 /* Overhead of a high-precision timing measurement. */
545 EXTERN hp_timing_t _dl_hp_timing_overhead
;
548 #ifdef NEED_DL_SYSINFO
549 /* Syscall handling improvements. This is very specific to x86. */
550 EXTERN
uintptr_t _dl_sysinfo
;
553 #ifdef NEED_DL_SYSINFO_DSO
554 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
555 This points to its ELF header. */
556 EXTERN
const ElfW(Ehdr
) *_dl_sysinfo_dso
;
558 /* At startup time we set up the normal DSO data structure for it,
559 and this points to it. */
560 EXTERN
struct link_map
*_dl_sysinfo_map
;
563 /* Mask for more hardware capabilities that are available on some
565 EXTERN
uint64_t _dl_hwcap2
;
568 /* We add a function table to _rtld_global which is then used to
569 call the function instead of going through the PLT. The result
570 is that we can avoid exporting the functions and we do not jump
571 PLT relocations in libc.so. */
572 void (*_dl_debug_printf
) (const char *, ...)
573 __attribute__ ((__format__ (__printf__
, 1, 2)));
574 int (internal_function
*_dl_catch_error
) (const char **, const char **,
575 bool *, void (*) (void *), void *);
576 void (internal_function
*_dl_signal_error
) (int, const char *, const char *,
578 void (*_dl_mcount
) (ElfW(Addr
) frompc
, ElfW(Addr
) selfpc
);
579 lookup_t (internal_function
*_dl_lookup_symbol_x
) (const char *,
582 struct r_scope_elem
*[],
583 const struct r_found_version
*,
586 int (*_dl_check_caller
) (const void *, enum allowmask
);
587 void *(*_dl_open
) (const char *file
, int mode
, const void *caller_dlopen
,
588 Lmid_t nsid
, int argc
, char *argv
[], char *env
[]);
589 void (*_dl_close
) (void *map
);
590 void *(*_dl_tls_get_addr_soft
) (struct link_map
*);
591 #ifdef HAVE_DL_DISCOVER_OSVERSION
592 int (*_dl_discover_osversion
) (void);
595 /* List of auditing interfaces. */
596 struct audit_ifaces
*_dl_audit
;
597 unsigned int _dl_naudit
;
599 /* 0 if internal pointer values should not be guarded, 1 if they should. */
600 EXTERN
int _dl_pointer_guard
;
602 # define __rtld_global_attribute__
604 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
605 extern struct rtld_global_ro _rtld_local_ro
606 attribute_relro __rtld_local_attribute__
;
607 extern struct rtld_global_ro _rtld_global_ro
608 attribute_relro __rtld_global_attribute__
;
609 # undef __rtld_local_attribute__
611 /* We cheat a bit here. We declare the variable as as const even
612 though it is at startup. */
613 extern const struct rtld_global_ro _rtld_global_ro
614 attribute_relro __rtld_global_attribute__
;
616 # undef __rtld_global_attribute__
621 /* dl-support.c defines these and initializes them early on. */
622 extern const ElfW(Phdr
) *_dl_phdr
;
623 extern size_t _dl_phnum
;
627 /* This is the initial value of GL(dl_error_catch_tsd).
628 A non-TLS libpthread will change it. */
629 extern void **_dl_initial_error_catch_tsd (void) __attribute__ ((const))
633 /* This is the initial value of GL(dl_make_stack_executable_hook).
634 A threads library can change it. */
635 extern int _dl_make_stack_executable (void **stack_endp
) internal_function
;
636 rtld_hidden_proto (_dl_make_stack_executable
)
638 /* Variable pointing to the end of the stack (or close to it). This value
639 must be constant over the runtime of the application. Some programs
640 might use the variable which results in copy relocations on some
641 platforms. But this does not matter, ld.so can always use the local
643 extern void *__libc_stack_end
644 #ifndef LIBC_STACK_END_NOT_RELRO
648 rtld_hidden_proto (__libc_stack_end
)
650 /* Parameters passed to the dynamic linker. */
651 extern int _dl_argc attribute_hidden attribute_relro
;
652 extern char **_dl_argv
653 #ifndef DL_ARGV_NOT_RELRO
658 extern unsigned int _dl_skip_args attribute_hidden
659 # ifndef DL_ARGV_NOT_RELRO
663 extern unsigned int _dl_skip_args_internal attribute_hidden
664 # ifndef DL_ARGV_NOT_RELRO
668 extern char **_dl_argv_internal attribute_hidden
669 # ifndef DL_ARGV_NOT_RELRO
673 # define rtld_progname (INTUSE(_dl_argv)[0])
675 # define rtld_progname _dl_argv[0]
678 /* Flag set at startup and cleared when the last initializer has run. */
679 extern int _dl_starting_up
;
680 weak_extern (_dl_starting_up
)
682 extern int _dl_starting_up_internal attribute_hidden
;
685 /* Random data provided by the kernel. */
686 extern void *_dl_random attribute_hidden attribute_relro
;
688 /* OS-dependent function to open the zero-fill device. */
689 extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
692 /* Write message on the debug file descriptor. The parameters are
693 interpreted as for a `printf' call. All the lines start with a
694 tag showing the PID. */
695 extern void _dl_debug_printf (const char *fmt
, ...)
696 __attribute__ ((__format__ (__printf__
, 1, 2))) attribute_hidden
;
698 /* Write message on the debug file descriptor. The parameters are
699 interpreted as for a `printf' call. All the lines buf the first
700 start with a tag showing the PID. */
701 extern void _dl_debug_printf_c (const char *fmt
, ...)
702 __attribute__ ((__format__ (__printf__
, 1, 2)));
705 /* Write a message on the specified descriptor FD. The parameters are
706 interpreted as for a `printf' call. */
707 extern void _dl_dprintf (int fd
, const char *fmt
, ...)
708 __attribute__ ((__format__ (__printf__
, 2, 3)))
711 /* Write a message on the specified descriptor standard output. The
712 parameters are interpreted as for a `printf' call. */
713 #define _dl_printf(fmt, args...) \
714 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
716 /* Write a message on the specified descriptor standard error. The
717 parameters are interpreted as for a `printf' call. */
718 #define _dl_error_printf(fmt, args...) \
719 _dl_dprintf (STDERR_FILENO, fmt, ##args)
721 /* Write a message on the specified descriptor standard error and exit
722 the program. The parameters are interpreted as for a `printf' call. */
723 #define _dl_fatal_printf(fmt, args...) \
726 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
732 /* This function is called by all the internal dynamic linker functions
733 when they encounter an error. ERRCODE is either an `errno' code or
734 zero; OBJECT is the name of the problematical shared object, or null if
735 it is a general problem; ERRSTRING is a string describing the specific
737 extern void _dl_signal_error (int errcode
, const char *object
,
738 const char *occurred
, const char *errstring
)
739 internal_function
__attribute__ ((__noreturn__
)) attribute_hidden
;
741 /* Like _dl_signal_error, but may return when called in the context of
742 _dl_receive_error. */
743 extern void _dl_signal_cerror (int errcode
, const char *object
,
744 const char *occation
, const char *errstring
)
747 /* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
748 `_dl_catch_error' the operation is resumed after the OPERATE
750 ARGS is passed as argument to OPERATE. */
751 extern void _dl_receive_error (receiver_fct fct
, void (*operate
) (void *),
756 /* Open the shared object NAME and map in its segments.
757 LOADER's DT_RPATH is used in searching for NAME.
758 If the object is already opened, returns its existing map. */
759 extern struct link_map
*_dl_map_object (struct link_map
*loader
,
761 int type
, int trace_mode
, int mode
,
763 internal_function attribute_hidden
;
765 /* Call _dl_map_object on the dependencies of MAP, and set up
766 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
767 loaded objects that will be inserted into MAP->l_searchlist after MAP
768 but before its dependencies. */
769 extern void _dl_map_object_deps (struct link_map
*map
,
770 struct link_map
**preloads
,
771 unsigned int npreloads
, int trace_mode
,
773 internal_function attribute_hidden
;
775 /* Cache the locations of MAP's hash table. */
776 extern void _dl_setup_hash (struct link_map
*map
)
777 internal_function attribute_hidden
;
780 /* Collect the directories in the search path for LOADER's dependencies.
781 The data structure is defined in <dlfcn.h>. If COUNTING is true,
782 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
783 by a previous call with COUNTING set, and SI must point to SI->dls_size
784 bytes to be used in filling in the result. */
785 extern void _dl_rtld_di_serinfo (struct link_map
*loader
,
786 Dl_serinfo
*si
, bool counting
)
790 /* Search loaded objects' symbol tables for a definition of the symbol
791 referred to by UNDEF. *SYM is the symbol table entry containing the
792 reference; it is replaced with the defining symbol, and the base load
793 address of the defining object is returned. SYMBOL_SCOPE is a
794 null-terminated list of object scopes to search; each object's
795 l_searchlist (i.e. the segment of the dependency tree starting at that
796 object) is searched in turn. REFERENCE_NAME should name the object
797 containing the reference; it is used in error messages.
798 TYPE_CLASS describes the type of symbol we are looking for. */
801 /* If necessary add dependency between user and provider object. */
802 DL_LOOKUP_ADD_DEPENDENCY
= 1,
803 /* Return most recent version instead of default version for
804 unversioned lookup. */
805 DL_LOOKUP_RETURN_NEWEST
= 2,
806 /* Set if dl_lookup* called with GSCOPE lock held. */
807 DL_LOOKUP_GSCOPE_LOCK
= 4,
810 /* Lookup versioned symbol. */
811 extern lookup_t
_dl_lookup_symbol_x (const char *undef
,
812 struct link_map
*undef_map
,
813 const ElfW(Sym
) **sym
,
814 struct r_scope_elem
*symbol_scope
[],
815 const struct r_found_version
*version
,
816 int type_class
, int flags
,
817 struct link_map
*skip_map
)
818 internal_function attribute_hidden
;
821 /* Look up symbol NAME in MAP's scope and return its run-time address. */
822 extern ElfW(Addr
) _dl_symbol_value (struct link_map
*map
, const char *name
)
825 /* Add the new link_map NEW to the end of the namespace list. */
826 extern void _dl_add_to_namespace_list (struct link_map
*new, Lmid_t nsid
)
827 internal_function attribute_hidden
;
829 /* Allocate a `struct link_map' for a new object being loaded. */
830 extern struct link_map
*_dl_new_object (char *realname
, const char *libname
,
831 int type
, struct link_map
*loader
,
832 int mode
, Lmid_t nsid
)
833 internal_function attribute_hidden
;
835 /* Relocate the given object (if it hasn't already been).
836 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
837 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
838 extern void _dl_relocate_object (struct link_map
*map
,
839 struct r_scope_elem
*scope
[],
840 int reloc_mode
, int consider_profiling
)
843 /* Protect PT_GNU_RELRO area. */
844 extern void _dl_protect_relro (struct link_map
*map
)
845 internal_function attribute_hidden
;
847 /* Call _dl_signal_error with a message about an unhandled reloc type.
848 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
849 PLT is nonzero if this was a PLT reloc; it just affects the message. */
850 extern void _dl_reloc_bad_type (struct link_map
*map
,
851 unsigned int type
, int plt
)
852 internal_function
__attribute__ ((__noreturn__
));
854 /* Resolve conflicts if prelinking. */
855 extern void _dl_resolve_conflicts (struct link_map
*l
,
856 ElfW(Rela
) *conflict
,
857 ElfW(Rela
) *conflictend
);
859 /* Check the version dependencies of all objects available through
860 MAP. If VERBOSE print some more diagnostics. */
861 extern int _dl_check_all_versions (struct link_map
*map
, int verbose
,
865 /* Check the version dependencies for MAP. If VERBOSE print some more
867 extern int _dl_check_map_versions (struct link_map
*map
, int verbose
,
871 /* Initialize the object in SCOPE by calling the constructors with
872 ARGC, ARGV, and ENV as the parameters. */
873 extern void _dl_init (struct link_map
*main_map
, int argc
, char **argv
,
874 char **env
) internal_function attribute_hidden
;
876 /* Call the finalizer functions of all shared objects whose
877 initializer functions have completed. */
878 extern void _dl_fini (void) internal_function
;
880 /* Sort array MAPS according to dependencies of the contained objects. */
881 extern void _dl_sort_fini (struct link_map
**maps
, size_t nmaps
, char *used
,
885 /* The dynamic linker calls this function before and having changing
886 any shared object mappings. The `r_state' member of `struct r_debug'
887 says what change is taking place. This function's address is
888 the value of the `r_brk' member. */
889 extern void _dl_debug_state (void);
890 rtld_hidden_proto (_dl_debug_state
)
892 /* Initialize `struct r_debug' if it has not already been done. The
893 argument is the run-time load address of the dynamic linker, to be put
894 in the `r_ldbase' member. Returns the address of the structure. */
895 extern struct r_debug
*_dl_debug_initialize (ElfW(Addr
) ldbase
, Lmid_t ns
)
898 /* Initialize the basic data structure for the search paths. */
899 extern void _dl_init_paths (const char *library_path
) internal_function
;
901 /* Gather the information needed to install the profiling tables and start
903 extern void _dl_start_profile (void) internal_function attribute_hidden
;
905 /* The actual functions used to keep book on the calls. */
906 extern void _dl_mcount (ElfW(Addr
) frompc
, ElfW(Addr
) selfpc
);
907 extern void _dl_mcount_internal (ElfW(Addr
) frompc
, ElfW(Addr
) selfpc
)
910 /* This function is simply a wrapper around the _dl_mcount function
911 which does not require a FROMPC parameter since this is the
913 extern void _dl_mcount_wrapper (void *selfpc
);
915 /* Show the members of the auxiliary array passed up from the kernel. */
916 extern void _dl_show_auxv (void) internal_function
;
918 /* Return all environment variables starting with `LD_', one after the
920 extern char *_dl_next_ld_env_entry (char ***position
) internal_function
;
922 /* Return an array with the names of the important hardware capabilities. */
923 extern const struct r_strlenpair
*_dl_important_hwcaps (const char *platform
,
926 size_t *max_capstrlen
)
929 /* Look up NAME in ld.so.cache and return the file name stored there,
930 or null if none is found. */
931 extern const char *_dl_load_cache_lookup (const char *name
)
934 /* If the system does not support MAP_COPY we cannot leave the file open
935 all the time since this would create problems when the file is replaced.
936 Therefore we provide this function to close the file and open it again
938 extern void _dl_unload_cache (void) attribute_hidden
;
940 /* System-dependent function to read a file's whole contents in the
941 most convenient manner available. *SIZEP gets the size of the
942 file. On error MAP_FAILED is returned. */
943 extern void *_dl_sysdep_read_whole_file (const char *file
, size_t *sizep
,
945 internal_function attribute_hidden
;
947 /* System-specific function to do initial startup for the dynamic linker.
948 After this, file access calls and getenv must work. This is responsible
949 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
950 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
951 extern ElfW(Addr
) _dl_sysdep_start (void **start_argptr
,
952 void (*dl_main
) (const ElfW(Phdr
) *phdr
,
954 ElfW(Addr
) *user_entry
,
958 extern void _dl_sysdep_start_cleanup (void)
959 internal_function attribute_hidden
;
962 /* Determine next available module ID. */
963 extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden
;
965 /* Calculate offset of the TLS blocks in the static TLS block. */
966 extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden
;
968 /* Set up the data structures for TLS, when they were not set up at startup.
969 Returns nonzero on malloc failure.
970 This is called from _dl_map_object_from_fd or by libpthread. */
971 extern int _dl_tls_setup (void) internal_function
;
972 rtld_hidden_proto (_dl_tls_setup
)
974 /* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
975 extern void *_dl_allocate_tls (void *mem
) internal_function
;
976 rtld_hidden_proto (_dl_allocate_tls
)
978 /* Get size and alignment requirements of the static TLS block. */
979 extern void _dl_get_tls_static_info (size_t *sizep
, size_t *alignp
)
982 extern void _dl_allocate_static_tls (struct link_map
*map
)
983 internal_function attribute_hidden
;
985 /* These are internal entry points to the two halves of _dl_allocate_tls,
986 only used within rtld.c itself at startup time. */
987 extern void *_dl_allocate_tls_storage (void)
988 internal_function attribute_hidden
;
989 extern void *_dl_allocate_tls_init (void *) internal_function
;
990 rtld_hidden_proto (_dl_allocate_tls_init
)
992 /* Remove all allocated dynamic TLS regions from a DTV
993 for reuse by new thread. */
994 extern void _dl_clear_dtv (dtv_t
*dtv
) internal_function
;
995 rtld_hidden_proto (_dl_clear_dtv
)
997 /* Deallocate memory allocated with _dl_allocate_tls. */
998 extern void _dl_deallocate_tls (void *tcb
, bool dealloc_tcb
) internal_function
;
999 rtld_hidden_proto (_dl_deallocate_tls
)
1001 extern void _dl_nothread_init_static_tls (struct link_map
*) attribute_hidden
;
1003 /* Find origin of the executable. */
1004 extern const char *_dl_get_origin (void) attribute_hidden
;
1007 extern size_t _dl_dst_count (const char *name
, int is_path
) attribute_hidden
;
1009 /* Substitute DST values. */
1010 extern char *_dl_dst_substitute (struct link_map
*l
, const char *name
,
1011 char *result
, int is_path
) attribute_hidden
;
1013 /* Check validity of the caller. */
1014 extern int _dl_check_caller (const void *caller
, enum allowmask mask
)
1017 /* Open the shared object NAME, relocate it, and run its initializer if it
1018 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1019 the object is already opened, returns its existing map. */
1020 extern void *_dl_open (const char *name
, int mode
, const void *caller
,
1021 Lmid_t nsid
, int argc
, char *argv
[], char *env
[])
1024 /* Free or queue for freeing scope OLD. If other threads might be
1025 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1026 old scope, OLD can't be freed until no thread is using it. */
1027 extern int _dl_scope_free (void *) attribute_hidden
;
1029 /* Add module to slot information data. */
1030 extern void _dl_add_to_slotinfo (struct link_map
*l
) attribute_hidden
;
1032 /* Update slot information data for at least the generation of the
1033 module with the given index. */
1034 extern struct link_map
*_dl_update_slotinfo (unsigned long int req_modid
);
1036 /* Look up the module's TLS block as for __tls_get_addr,
1037 but never touch anything. Return null if it's not allocated yet. */
1038 extern void *_dl_tls_get_addr_soft (struct link_map
*l
) attribute_hidden
;
1040 extern int _dl_addr_inside_object (struct link_map
*l
, const ElfW(Addr
) addr
)
1041 internal_function attribute_hidden
;
1043 /* Show show of an object. */
1044 extern void _dl_show_scope (struct link_map
*new, int from
);
1046 extern struct link_map
*_dl_find_dso_for_object (const ElfW(Addr
) addr
)
1048 rtld_hidden_proto (_dl_find_dso_for_object
)
1050 /* Initialization which is normally done by the dynamic linker. */
1051 extern void _dl_non_dynamic_init (void) internal_function
;
1053 /* Used by static binaries to check the auxiliary vector. */
1054 extern void _dl_aux_init (ElfW(auxv_t
) *av
) internal_function
;
1059 #endif /* ldsodefs.h */