1 /* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2017 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 <libc-lock.h>
39 #include <hp-timing.h>
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))
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)
54 /* All references to the value of l_info[DT_PLTGOT],
55 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
56 l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
57 have to be accessed via the D_PTR macro. The macro is needed since for
58 most architectures the entry is already relocated - but for some not
59 and we need to relocate at access time. */
60 #ifdef DL_RO_DYN_SECTION
61 # define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
63 # define D_PTR(map, i) (map)->i->d_un.d_ptr
66 /* Result of the lookup functions and how to retrieve the base address. */
67 typedef struct link_map
*lookup_t
;
68 #define LOOKUP_VALUE(map) map
69 #define LOOKUP_VALUE_ADDRESS(map) ((map) ? (map)->l_addr : 0)
71 /* On some architectures a pointer to a function is not just a pointer
72 to the actual code of the function but rather an architecture
73 specific descriptor. */
74 #ifndef ELF_FUNCTION_PTR_IS_SPECIAL
75 # define DL_SYMBOL_ADDRESS(map, ref) \
76 (void *) (LOOKUP_VALUE_ADDRESS (map) + ref->st_value)
77 # define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
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)) ()
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 \
86 && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
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))
91 /* According to the ELF gABI no STV_HIDDEN or STV_INTERNAL symbols are
92 expected to be present in dynamic symbol tables as they should have
93 been either removed or converted to STB_LOCAL binding by the static
94 linker. However some GNU binutils versions produce such symbols in
95 some cases. To prevent such symbols present in a buggy binary from
96 preempting global symbols we filter them out with this predicate. */
97 static __always_inline
bool
98 dl_symbol_visibility_binds_local_p (const ElfW(Sym
) *sym
)
100 return (ELFW(ST_VISIBILITY
) (sym
->st_other
) == STV_HIDDEN
101 || ELFW(ST_VISIBILITY
) (sym
->st_other
) == STV_INTERNAL
);
104 /* Unmap a loaded object, called by _dl_close (). */
105 #ifndef DL_UNMAP_IS_SPECIAL
106 # define DL_UNMAP(map) _dl_unmap_segments (map)
109 /* By default we do not need special support to initialize DSOs loaded
110 by statically linked binaries. */
111 #ifndef DL_STATIC_INIT
112 # define DL_STATIC_INIT(map)
115 /* Reloc type classes as returned by elf_machine_type_class().
116 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
117 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
118 satisfied by any symbol in the executable. Some architectures do
119 not support copy relocations. In this case we define the macro to
120 zero so that the code for handling them gets automatically optimized
121 out. ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA means address of protected
122 data defined in the shared library may be external, i.e., due to copy
124 #define ELF_RTYPE_CLASS_PLT 1
125 #ifndef DL_NO_COPY_RELOCS
126 # define ELF_RTYPE_CLASS_COPY 2
128 # define ELF_RTYPE_CLASS_COPY 0
130 /* If DL_EXTERN_PROTECTED_DATA is defined, address of protected data
131 defined in the shared library may be external, i.e., due to copy
133 #ifdef DL_EXTERN_PROTECTED_DATA
134 # define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 4
136 # define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 0
139 /* ELF uses the PF_x macros to specify the segment permissions, mmap
140 uses PROT_xxx. In most cases the three macros have the values 1, 2,
141 and 3 but not in a matching order. The following macros allows
142 converting from the PF_x values to PROT_xxx values. */
144 ((PROT_READ << (PF_R * 4)) \
145 | (PROT_WRITE << (PF_W * 4)) \
146 | (PROT_EXEC << (PF_X * 4)) \
147 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
148 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
149 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
150 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
152 /* The filename itself, or the main program name, if available. */
153 #define DSO_FILENAME(name) ((name)[0] ? (name) \
154 : (rtld_progname ?: "<main program>"))
156 #define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
158 /* For the version handling we need an array with only names and their
160 struct r_found_version
166 const char *filename
;
169 /* We want to cache information about the searches for shared objects. */
171 enum r_dir_status
{ unknown
, nonexisting
, existing
};
173 struct r_search_path_elem
175 /* This link is only used in the `all_dirs' member of `r_search_path'. */
176 struct r_search_path_elem
*next
;
178 /* Strings saying where the definition came from. */
182 /* Basename for this search path element. The string must end with
183 a slash character. */
187 enum r_dir_status status
[0];
197 /* A data structure for a simple single linked list of strings. */
200 const char *name
; /* Name requested (before search). */
201 struct libname_list
*next
; /* Link to next name for this object. */
202 int dont_free
; /* Flag whether this element should be freed
203 if the object is not entirely unloaded. */
207 /* Bit masks for the objects which valid callers can come from to
208 functions with restricted interface. */
213 allow_libpthread
= 4,
220 void (*activity
) (uintptr_t *, unsigned int);
221 char *(*objsearch
) (const char *, uintptr_t *, unsigned int);
222 unsigned int (*objopen
) (struct link_map
*, Lmid_t
, uintptr_t *);
223 void (*preinit
) (uintptr_t *);
226 uintptr_t (*symbind32
) (Elf32_Sym
*, unsigned int, uintptr_t *,
227 uintptr_t *, unsigned int *, const char *);
228 uintptr_t (*symbind64
) (Elf64_Sym
*, unsigned int, uintptr_t *,
229 uintptr_t *, unsigned int *, const char *);
233 #ifdef ARCH_PLTENTER_MEMBERS
234 ARCH_PLTENTER_MEMBERS
;
239 #ifdef ARCH_PLTEXIT_MEMBERS
240 ARCH_PLTEXIT_MEMBERS
;
243 unsigned int (*objclose
) (uintptr_t *);
245 struct audit_ifaces
*next
;
249 /* Test whether given NAME matches any of the names of the given object. */
250 extern int _dl_name_match_p (const char *__name
, const struct link_map
*__map
)
251 internal_function attribute_hidden
;
253 /* Compute next higher prime number. */
254 extern unsigned long int _dl_higher_prime_number (unsigned long int n
)
255 internal_function attribute_hidden
;
257 /* A stripped down strtoul-like implementation. */
258 uint64_t internal_function
_dl_strtoul (const char *, char **)
259 internal_function attribute_hidden
;
261 /* Function used as argument for `_dl_receive_error' function. The
262 arguments are the error code, error string, and the objname the
263 error occurred in. */
264 typedef void (*receiver_fct
) (int, const char *, const char *);
266 /* Internal functions of the run-time dynamic linker.
267 These can be accessed if you link again the dynamic linker
268 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
269 but are not normally of interest to user programs.
271 The `-ldl' library functions in <dlfcn.h> provide a simple
272 user interface to run-time dynamic linking. */
276 # define EXTERN extern
277 # define GL(name) _##name
281 # define GL(name) _rtld_local._##name
283 # define GL(name) _rtld_global._##name
288 /* Don't change the order of the following elements. 'dl_loaded'
289 must remain the first element. Forever. */
291 /* Non-shared code has no support for multiple namespaces. */
297 EXTERN
struct link_namespaces
299 /* A pointer to the map for the main map. */
300 struct link_map
*_ns_loaded
;
301 /* Number of object in the _dl_loaded list. */
302 unsigned int _ns_nloaded
;
303 /* Direct pointer to the searchlist of the main object. */
304 struct r_scope_elem
*_ns_main_searchlist
;
305 /* This is zero at program start to signal that the global scope map is
306 allocated by rtld. Later it keeps the size of the map. It might be
307 reset if in _dl_close if the last global object is removed. */
308 size_t _ns_global_scope_alloc
;
309 /* Search table for unique objects. */
310 struct unique_sym_table
312 __rtld_lock_define_recursive (, lock
)
317 const ElfW(Sym
) *sym
;
318 const struct link_map
*map
;
322 void (*free
) (void *);
323 } _ns_unique_sym_table
;
324 /* Keep track of changes to each namespace' list. */
325 struct r_debug _ns_debug
;
327 /* One higher than index of last used namespace. */
328 EXTERN
size_t _dl_nns
;
330 /* During the program run we must not modify the global data of
331 loaded shared object simultanously in two threads. Therefore we
332 protect `_dl_open' and `_dl_close' in dl-close.c.
334 This must be a recursive lock since the initializer function of
335 the loaded object might as well require a call to this function.
336 At this time it is not anymore a problem to modify the tables. */
337 __rtld_lock_define_recursive (EXTERN
, _dl_load_lock
)
338 /* This lock is used to keep __dl_iterate_phdr from inspecting the
339 list of loaded objects while an object is added to or removed
341 __rtld_lock_define_recursive (EXTERN
, _dl_load_write_lock
)
343 /* Incremented whenever something may have been added to dl_loaded. */
344 EXTERN
unsigned long long _dl_load_adds
;
346 /* The object to be initialized first. */
347 EXTERN
struct link_map
*_dl_initfirst
;
349 #if HP_SMALL_TIMING_AVAIL
350 /* Start time on CPU clock. */
351 EXTERN hp_timing_t _dl_cpuclock_offset
;
354 /* Map of shared object to be profiled. */
355 EXTERN
struct link_map
*_dl_profile_map
;
357 /* Counters for the number of relocations performed. */
358 EXTERN
unsigned long int _dl_num_relocations
;
359 EXTERN
unsigned long int _dl_num_cache_relocations
;
361 /* List of search directories. */
362 EXTERN
struct r_search_path_elem
*_dl_all_dirs
;
364 /* Structure describing the dynamic linker itself. We need to
365 reserve memory for the data the audit libraries need. */
366 EXTERN
struct link_map _dl_rtld_map
;
368 struct auditstate audit_data
[DL_NNS
];
371 #if defined SHARED && defined _LIBC_REENTRANT \
372 && defined __rtld_lock_default_lock_recursive
373 EXTERN
void (*_dl_rtld_lock_recursive
) (void *);
374 EXTERN
void (*_dl_rtld_unlock_recursive
) (void *);
377 /* If loading a shared object requires that we make the stack executable
378 when it was not, we do it by calling this function.
379 It returns an errno code or zero on success. */
380 EXTERN
int (*_dl_make_stack_executable_hook
) (void **) internal_function
;
382 /* Prevailing state of the stack, PF_X indicating it's executable. */
383 EXTERN
ElfW(Word
) _dl_stack_flags
;
385 /* Flag signalling whether there are gaps in the module ID allocation. */
386 EXTERN
bool _dl_tls_dtv_gaps
;
387 /* Highest dtv index currently needed. */
388 EXTERN
size_t _dl_tls_max_dtv_idx
;
389 /* Information about the dtv slots. */
390 EXTERN
struct dtv_slotinfo_list
393 struct dtv_slotinfo_list
*next
;
397 struct link_map
*map
;
399 } *_dl_tls_dtv_slotinfo_list
;
400 /* Number of modules in the static TLS block. */
401 EXTERN
size_t _dl_tls_static_nelem
;
402 /* Size of the static TLS block. */
403 EXTERN
size_t _dl_tls_static_size
;
404 /* Size actually allocated in the static TLS block. */
405 EXTERN
size_t _dl_tls_static_used
;
406 /* Alignment requirement of the static TLS block. */
407 EXTERN
size_t _dl_tls_static_align
;
409 /* Number of additional entries in the slotinfo array of each slotinfo
410 list element. A large number makes it almost certain take we never
411 have to iterate beyond the first element in the slotinfo list. */
412 #define TLS_SLOTINFO_SURPLUS (62)
414 /* Number of additional slots in the dtv allocated. */
415 #define DTV_SURPLUS (14)
417 /* Initial dtv of the main thread, not allocated with normal malloc. */
418 EXTERN
void *_dl_initial_dtv
;
419 /* Generation counter for the dtv. */
420 EXTERN
size_t _dl_tls_generation
;
422 EXTERN
void (*_dl_init_static_tls
) (struct link_map
*);
424 EXTERN
void (*_dl_wait_lookup_done
) (void);
426 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
427 EXTERN
struct dl_scope_free_list
431 } *_dl_scope_free_list
;
434 # define __rtld_global_attribute__
436 # ifdef HAVE_SDATA_SECTION
437 # define __rtld_local_attribute__ \
438 __attribute__ ((visibility ("hidden"), section (".sdata")))
439 # undef __rtld_global_attribute__
440 # define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
442 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
444 extern struct rtld_global _rtld_local __rtld_local_attribute__
;
445 # undef __rtld_local_attribute__
447 extern struct rtld_global _rtld_global __rtld_global_attribute__
;
448 # undef __rtld_global_attribute__
452 # define GLRO(name) _##name
455 # define GLRO(name) _rtld_local_ro._##name
457 # define GLRO(name) _rtld_global_ro._##name
459 struct rtld_global_ro
463 /* If nonzero the appropriate debug information is printed. */
464 EXTERN
int _dl_debug_mask
;
465 #define DL_DEBUG_LIBS (1 << 0)
466 #define DL_DEBUG_IMPCALLS (1 << 1)
467 #define DL_DEBUG_BINDINGS (1 << 2)
468 #define DL_DEBUG_SYMBOLS (1 << 3)
469 #define DL_DEBUG_VERSIONS (1 << 4)
470 #define DL_DEBUG_RELOC (1 << 5)
471 #define DL_DEBUG_FILES (1 << 6)
472 #define DL_DEBUG_STATISTICS (1 << 7)
473 #define DL_DEBUG_UNUSED (1 << 8)
474 #define DL_DEBUG_SCOPES (1 << 9)
475 /* These two are used only internally. */
476 #define DL_DEBUG_HELP (1 << 10)
477 #define DL_DEBUG_PRELINK (1 << 11)
480 EXTERN
unsigned int _dl_osversion
;
482 EXTERN
const char *_dl_platform
;
483 EXTERN
size_t _dl_platformlen
;
485 /* Cached value of `getpagesize ()'. */
486 EXTERN
size_t _dl_pagesize
;
488 /* Do we read from ld.so.cache? */
489 EXTERN
int _dl_inhibit_cache
;
491 /* Copy of the content of `_dl_main_searchlist' at startup time. */
492 EXTERN
struct r_scope_elem _dl_initial_searchlist
;
494 /* CLK_TCK as reported by the kernel. */
495 EXTERN
int _dl_clktck
;
497 /* If nonzero print warnings messages. */
498 EXTERN
int _dl_verbose
;
500 /* File descriptor to write debug messages to. */
501 EXTERN
int _dl_debug_fd
;
503 /* Do we do lazy relocations? */
506 /* Nonzero if runtime lookups should not update the .got/.plt. */
507 EXTERN
int _dl_bind_not
;
509 /* Nonzero if references should be treated as weak during runtime
511 EXTERN
int _dl_dynamic_weak
;
513 /* Default floating-point control word. */
514 EXTERN fpu_control_t _dl_fpu_control
;
516 /* Expected cache ID. */
517 EXTERN
int _dl_correct_cache_id
;
519 /* Mask for hardware capabilities that are available. */
520 EXTERN
uint64_t _dl_hwcap
;
523 /* Mask for important hardware capabilities we honour. */
524 EXTERN
uint64_t _dl_hwcap_mask
;
527 #ifdef HAVE_AUX_VECTOR
528 /* Pointer to the auxv list supplied to the program at startup. */
529 EXTERN
ElfW(auxv_t
) *_dl_auxv
;
532 /* Get architecture specific definitions. */
533 #define PROCINFO_DECL
534 #ifndef PROCINFO_CLASS
535 # define PROCINFO_CLASS EXTERN
537 #include <dl-procinfo.c>
539 /* Names of shared object for which the RPATH should be ignored. */
540 EXTERN
const char *_dl_inhibit_rpath
;
542 /* Location of the binary. */
543 EXTERN
const char *_dl_origin_path
;
545 /* -1 if the dynamic linker should honor library load bias,
546 0 if not, -2 use the default (honor biases for normal
547 binaries, don't honor for PIEs). */
548 EXTERN
ElfW(Addr
) _dl_use_load_bias
;
550 /* Name of the shared object to be profiled (if any). */
551 EXTERN
const char *_dl_profile
;
552 /* Filename of the output file. */
553 EXTERN
const char *_dl_profile_output
;
554 /* Name of the object we want to trace the prelinking. */
555 EXTERN
const char *_dl_trace_prelink
;
556 /* Map of shared object to be prelink traced. */
557 EXTERN
struct link_map
*_dl_trace_prelink_map
;
559 /* All search directories defined at startup. */
560 EXTERN
struct r_search_path_elem
*_dl_init_all_dirs
;
562 #ifdef NEED_DL_SYSINFO
563 /* Syscall handling improvements. This is very specific to x86. */
564 EXTERN
uintptr_t _dl_sysinfo
;
567 #ifdef NEED_DL_SYSINFO_DSO
568 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
569 This points to its ELF header. */
570 EXTERN
const ElfW(Ehdr
) *_dl_sysinfo_dso
;
572 /* At startup time we set up the normal DSO data structure for it,
573 and this points to it. */
574 EXTERN
struct link_map
*_dl_sysinfo_map
;
577 /* Mask for more hardware capabilities that are available on some
579 EXTERN
uint64_t _dl_hwcap2
;
582 /* We add a function table to _rtld_global which is then used to
583 call the function instead of going through the PLT. The result
584 is that we can avoid exporting the functions and we do not jump
585 PLT relocations in libc.so. */
586 void (*_dl_debug_printf
) (const char *, ...)
587 __attribute__ ((__format__ (__printf__
, 1, 2)));
588 void (*_dl_mcount
) (ElfW(Addr
) frompc
, ElfW(Addr
) selfpc
);
589 lookup_t (internal_function
*_dl_lookup_symbol_x
) (const char *,
592 struct r_scope_elem
*[],
593 const struct r_found_version
*,
596 int (*_dl_check_caller
) (const void *, enum allowmask
);
597 void *(*_dl_open
) (const char *file
, int mode
, const void *caller_dlopen
,
598 Lmid_t nsid
, int argc
, char *argv
[], char *env
[]);
599 void (*_dl_close
) (void *map
);
600 void *(*_dl_tls_get_addr_soft
) (struct link_map
*);
601 #ifdef HAVE_DL_DISCOVER_OSVERSION
602 int (*_dl_discover_osversion
) (void);
605 /* List of auditing interfaces. */
606 struct audit_ifaces
*_dl_audit
;
607 unsigned int _dl_naudit
;
609 # define __rtld_global_attribute__
611 # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
612 extern struct rtld_global_ro _rtld_local_ro
613 attribute_relro __rtld_local_attribute__
;
614 extern struct rtld_global_ro _rtld_global_ro
615 attribute_relro __rtld_global_attribute__
;
616 # undef __rtld_local_attribute__
618 /* We cheat a bit here. We declare the variable as as const even
619 though it is at startup. */
620 extern const struct rtld_global_ro _rtld_global_ro
621 attribute_relro __rtld_global_attribute__
;
623 # undef __rtld_global_attribute__
628 /* dl-support.c defines these and initializes them early on. */
629 extern const ElfW(Phdr
) *_dl_phdr
;
630 extern size_t _dl_phnum
;
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
657 rtld_hidden_proto (_dl_argv
)
659 extern unsigned int _dl_skip_args attribute_hidden
660 # ifndef DL_ARGV_NOT_RELRO
664 extern unsigned int _dl_skip_args_internal attribute_hidden
665 # ifndef DL_ARGV_NOT_RELRO
670 #define rtld_progname _dl_argv[0]
672 /* Flag set at startup and cleared when the last initializer has run. */
673 extern int _dl_starting_up
;
674 weak_extern (_dl_starting_up
)
675 rtld_hidden_proto (_dl_starting_up
)
677 /* Random data provided by the kernel. */
678 extern void *_dl_random attribute_hidden attribute_relro
;
680 /* OS-dependent function to open the zero-fill device. */
681 extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
684 /* Write message on the debug file descriptor. The parameters are
685 interpreted as for a `printf' call. All the lines start with a
686 tag showing the PID. */
687 extern void _dl_debug_printf (const char *fmt
, ...)
688 __attribute__ ((__format__ (__printf__
, 1, 2))) attribute_hidden
;
690 /* Write message on the debug file descriptor. The parameters are
691 interpreted as for a `printf' call. All the lines buf the first
692 start with a tag showing the PID. */
693 extern void _dl_debug_printf_c (const char *fmt
, ...)
694 __attribute__ ((__format__ (__printf__
, 1, 2))) attribute_hidden
;
697 /* Write a message on the specified descriptor FD. The parameters are
698 interpreted as for a `printf' call. */
699 #if IS_IN (rtld) || !defined (SHARED)
700 extern void _dl_dprintf (int fd
, const char *fmt
, ...)
701 __attribute__ ((__format__ (__printf__
, 2, 3)))
704 __attribute__ ((always_inline
, __format__ (__printf__
, 2, 3)))
706 _dl_dprintf (int fd
, const char *fmt
, ...)
708 /* Use local declaration to avoid includign <stdio.h>. */
709 extern int __dprintf(int fd
, const char *format
, ...) attribute_hidden
;
710 __dprintf (fd
, fmt
, __builtin_va_arg_pack ());
714 /* Write a message on the specified descriptor standard output. The
715 parameters are interpreted as for a `printf' call. */
716 #define _dl_printf(fmt, args...) \
717 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
719 /* Write a message on the specified descriptor standard error. The
720 parameters are interpreted as for a `printf' call. */
721 #define _dl_error_printf(fmt, args...) \
722 _dl_dprintf (STDERR_FILENO, fmt, ##args)
724 /* Write a message on the specified descriptor standard error and exit
725 the program. The parameters are interpreted as for a `printf' call. */
726 #define _dl_fatal_printf(fmt, args...) \
729 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
735 /* This function is called by all the internal dynamic linker functions
736 when they encounter an error. ERRCODE is either an `errno' code or
737 zero; OBJECT is the name of the problematical shared object, or null if
738 it is a general problem; ERRSTRING is a string describing the specific
740 extern void _dl_signal_error (int errcode
, const char *object
,
741 const char *occurred
, const char *errstring
)
742 internal_function
__attribute__ ((__noreturn__
));
743 libc_hidden_proto (_dl_signal_error
)
745 /* Like _dl_signal_error, but may return when called in the context of
746 _dl_receive_error. This is only used during ld.so bootstrap. In
747 static and profiled builds, this is equivalent to
750 extern void _dl_signal_cerror (int errcode
, const char *object
,
751 const char *occation
, const char *errstring
)
752 internal_function attribute_hidden
;
754 __attribute__ ((always_inline
))
756 _dl_signal_cerror (int errcode
, const char *object
,
757 const char *occation
, const char *errstring
)
759 _dl_signal_error (errcode
, object
, occation
, errstring
);
763 /* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
764 `_dl_catch_error' the operation is resumed after the OPERATE
766 ARGS is passed as argument to OPERATE. */
767 extern void _dl_receive_error (receiver_fct fct
, void (*operate
) (void *),
769 internal_function attribute_hidden
;
771 /* Call OPERATE, catching errors from `dl_signal_error'. If there is no
772 error, *ERRSTRING is set to null. If there is an error, *ERRSTRING is
773 set to a string constructed from the strings passed to _dl_signal_error,
774 and the error code passed is the return value and *OBJNAME is set to
775 the object name which experienced the problems. ERRSTRING if nonzero
776 points to a malloc'ed string which the caller has to free after use.
777 ARGS is passed as argument to OPERATE. MALLOCEDP is set to true only
778 if the returned string is allocated using the libc's malloc. */
779 extern int _dl_catch_error (const char **objname
, const char **errstring
,
780 bool *mallocedp
, void (*operate
) (void *),
783 libc_hidden_proto (_dl_catch_error
)
785 /* Open the shared object NAME and map in its segments.
786 LOADER's DT_RPATH is used in searching for NAME.
787 If the object is already opened, returns its existing map. */
788 extern struct link_map
*_dl_map_object (struct link_map
*loader
,
790 int type
, int trace_mode
, int mode
,
792 internal_function attribute_hidden
;
794 /* Call _dl_map_object on the dependencies of MAP, and set up
795 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
796 loaded objects that will be inserted into MAP->l_searchlist after MAP
797 but before its dependencies. */
798 extern void _dl_map_object_deps (struct link_map
*map
,
799 struct link_map
**preloads
,
800 unsigned int npreloads
, int trace_mode
,
802 internal_function attribute_hidden
;
804 /* Cache the locations of MAP's hash table. */
805 extern void _dl_setup_hash (struct link_map
*map
)
806 internal_function attribute_hidden
;
809 /* Collect the directories in the search path for LOADER's dependencies.
810 The data structure is defined in <dlfcn.h>. If COUNTING is true,
811 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
812 by a previous call with COUNTING set, and SI must point to SI->dls_size
813 bytes to be used in filling in the result. */
814 extern void _dl_rtld_di_serinfo (struct link_map
*loader
,
815 Dl_serinfo
*si
, bool counting
)
819 /* Search loaded objects' symbol tables for a definition of the symbol
820 referred to by UNDEF. *SYM is the symbol table entry containing the
821 reference; it is replaced with the defining symbol, and the base load
822 address of the defining object is returned. SYMBOL_SCOPE is a
823 null-terminated list of object scopes to search; each object's
824 l_searchlist (i.e. the segment of the dependency tree starting at that
825 object) is searched in turn. REFERENCE_NAME should name the object
826 containing the reference; it is used in error messages.
827 TYPE_CLASS describes the type of symbol we are looking for. */
830 /* If necessary add dependency between user and provider object. */
831 DL_LOOKUP_ADD_DEPENDENCY
= 1,
832 /* Return most recent version instead of default version for
833 unversioned lookup. */
834 DL_LOOKUP_RETURN_NEWEST
= 2,
835 /* Set if dl_lookup* called with GSCOPE lock held. */
836 DL_LOOKUP_GSCOPE_LOCK
= 4,
839 /* Lookup versioned symbol. */
840 extern lookup_t
_dl_lookup_symbol_x (const char *undef
,
841 struct link_map
*undef_map
,
842 const ElfW(Sym
) **sym
,
843 struct r_scope_elem
*symbol_scope
[],
844 const struct r_found_version
*version
,
845 int type_class
, int flags
,
846 struct link_map
*skip_map
)
847 internal_function attribute_hidden
;
850 /* Look up symbol NAME in MAP's scope and return its run-time address. */
851 extern ElfW(Addr
) _dl_symbol_value (struct link_map
*map
, const char *name
)
854 /* Add the new link_map NEW to the end of the namespace list. */
855 extern void _dl_add_to_namespace_list (struct link_map
*new, Lmid_t nsid
)
856 internal_function attribute_hidden
;
858 /* Allocate a `struct link_map' for a new object being loaded. */
859 extern struct link_map
*_dl_new_object (char *realname
, const char *libname
,
860 int type
, struct link_map
*loader
,
861 int mode
, Lmid_t nsid
)
862 internal_function attribute_hidden
;
864 /* Relocate the given object (if it hasn't already been).
865 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
866 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
867 extern void _dl_relocate_object (struct link_map
*map
,
868 struct r_scope_elem
*scope
[],
869 int reloc_mode
, int consider_profiling
)
872 /* Protect PT_GNU_RELRO area. */
873 extern void _dl_protect_relro (struct link_map
*map
)
874 internal_function attribute_hidden
;
876 /* Call _dl_signal_error with a message about an unhandled reloc type.
877 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
878 PLT is nonzero if this was a PLT reloc; it just affects the message. */
879 extern void _dl_reloc_bad_type (struct link_map
*map
,
880 unsigned int type
, int plt
)
881 internal_function attribute_hidden
__attribute__ ((__noreturn__
));
883 /* Resolve conflicts if prelinking. */
884 extern void _dl_resolve_conflicts (struct link_map
*l
,
885 ElfW(Rela
) *conflict
,
886 ElfW(Rela
) *conflictend
)
889 /* Check the version dependencies of all objects available through
890 MAP. If VERBOSE print some more diagnostics. */
891 extern int _dl_check_all_versions (struct link_map
*map
, int verbose
,
893 internal_function attribute_hidden
;
895 /* Check the version dependencies for MAP. If VERBOSE print some more
897 extern int _dl_check_map_versions (struct link_map
*map
, int verbose
,
899 internal_function attribute_hidden
;
901 /* Initialize the object in SCOPE by calling the constructors with
902 ARGC, ARGV, and ENV as the parameters. */
903 extern void _dl_init (struct link_map
*main_map
, int argc
, char **argv
,
904 char **env
) internal_function attribute_hidden
;
906 /* Call the finalizer functions of all shared objects whose
907 initializer functions have completed. */
908 extern void _dl_fini (void) internal_function
;
910 /* Sort array MAPS according to dependencies of the contained objects. */
911 extern void _dl_sort_fini (struct link_map
**maps
, size_t nmaps
, char *used
,
913 internal_function attribute_hidden
;
915 /* The dynamic linker calls this function before and having changing
916 any shared object mappings. The `r_state' member of `struct r_debug'
917 says what change is taking place. This function's address is
918 the value of the `r_brk' member. */
919 extern void _dl_debug_state (void);
920 rtld_hidden_proto (_dl_debug_state
)
922 /* Initialize `struct r_debug' if it has not already been done. The
923 argument is the run-time load address of the dynamic linker, to be put
924 in the `r_ldbase' member. Returns the address of the structure. */
925 extern struct r_debug
*_dl_debug_initialize (ElfW(Addr
) ldbase
, Lmid_t ns
)
926 internal_function attribute_hidden
;
928 /* Initialize the basic data structure for the search paths. */
929 extern void _dl_init_paths (const char *library_path
)
930 internal_function attribute_hidden
;
932 /* Gather the information needed to install the profiling tables and start
934 extern void _dl_start_profile (void) internal_function attribute_hidden
;
936 /* The actual functions used to keep book on the calls. */
937 extern void _dl_mcount (ElfW(Addr
) frompc
, ElfW(Addr
) selfpc
);
938 rtld_hidden_proto (_dl_mcount
)
940 /* This function is simply a wrapper around the _dl_mcount function
941 which does not require a FROMPC parameter since this is the
943 extern void _dl_mcount_wrapper (void *selfpc
);
945 /* Show the members of the auxiliary array passed up from the kernel. */
946 extern void _dl_show_auxv (void)
947 internal_function attribute_hidden
;
949 /* Return all environment variables starting with `LD_', one after the
951 extern char *_dl_next_ld_env_entry (char ***position
)
952 internal_function attribute_hidden
;
954 /* Return an array with the names of the important hardware capabilities. */
955 extern const struct r_strlenpair
*_dl_important_hwcaps (const char *platform
,
958 size_t *max_capstrlen
)
959 internal_function attribute_hidden
;
961 /* Look up NAME in ld.so.cache and return the file name stored there,
962 or null if none is found. Caller must free returned string. */
963 extern char *_dl_load_cache_lookup (const char *name
)
964 internal_function attribute_hidden
;
966 /* If the system does not support MAP_COPY we cannot leave the file open
967 all the time since this would create problems when the file is replaced.
968 Therefore we provide this function to close the file and open it again
970 extern void _dl_unload_cache (void) attribute_hidden
;
972 /* System-dependent function to read a file's whole contents in the
973 most convenient manner available. *SIZEP gets the size of the
974 file. On error MAP_FAILED is returned. */
975 extern void *_dl_sysdep_read_whole_file (const char *file
, size_t *sizep
,
977 internal_function attribute_hidden
;
979 /* System-specific function to do initial startup for the dynamic linker.
980 After this, file access calls and getenv must work. This is responsible
981 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
982 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
983 extern ElfW(Addr
) _dl_sysdep_start (void **start_argptr
,
984 void (*dl_main
) (const ElfW(Phdr
) *phdr
,
986 ElfW(Addr
) *user_entry
,
990 extern void _dl_sysdep_start_cleanup (void)
991 internal_function attribute_hidden
;
994 /* Determine next available module ID. */
995 extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden
;
997 /* Count the modules with TLS segments. */
998 extern size_t _dl_count_modids (void) internal_function attribute_hidden
;
1000 /* Calculate offset of the TLS blocks in the static TLS block. */
1001 extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden
;
1004 /* Set up the TCB for statically linked applications. This is called
1005 early during startup because we always use TLS (for errno and the
1006 stack protector, among other things). */
1007 void __libc_setup_tls (void);
1009 /* Initialization of libpthread for statically linked applications.
1010 If libpthread is not linked in, this is an empty function. */
1011 void __pthread_initialize_minimal (void) weak_function
;
1014 /* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
1015 extern void *_dl_allocate_tls (void *mem
) internal_function
;
1016 rtld_hidden_proto (_dl_allocate_tls
)
1018 /* Get size and alignment requirements of the static TLS block. */
1019 extern void _dl_get_tls_static_info (size_t *sizep
, size_t *alignp
)
1022 extern void _dl_allocate_static_tls (struct link_map
*map
)
1023 internal_function attribute_hidden
;
1025 /* These are internal entry points to the two halves of _dl_allocate_tls,
1026 only used within rtld.c itself at startup time. */
1027 extern void *_dl_allocate_tls_storage (void)
1028 internal_function attribute_hidden
;
1029 extern void *_dl_allocate_tls_init (void *) internal_function
;
1030 rtld_hidden_proto (_dl_allocate_tls_init
)
1032 /* Deallocate memory allocated with _dl_allocate_tls. */
1033 extern void _dl_deallocate_tls (void *tcb
, bool dealloc_tcb
) internal_function
;
1034 rtld_hidden_proto (_dl_deallocate_tls
)
1036 extern void _dl_nothread_init_static_tls (struct link_map
*) attribute_hidden
;
1038 /* Find origin of the executable. */
1039 extern const char *_dl_get_origin (void) attribute_hidden
;
1042 extern size_t _dl_dst_count (const char *name
, int is_path
) attribute_hidden
;
1044 /* Substitute DST values. */
1045 extern char *_dl_dst_substitute (struct link_map
*l
, const char *name
,
1046 char *result
, int is_path
) attribute_hidden
;
1048 /* Check validity of the caller. */
1049 extern int _dl_check_caller (const void *caller
, enum allowmask mask
)
1052 /* Open the shared object NAME, relocate it, and run its initializer if it
1053 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1054 the object is already opened, returns its existing map. */
1055 extern void *_dl_open (const char *name
, int mode
, const void *caller
,
1056 Lmid_t nsid
, int argc
, char *argv
[], char *env
[])
1059 /* Free or queue for freeing scope OLD. If other threads might be
1060 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1061 old scope, OLD can't be freed until no thread is using it. */
1062 extern int _dl_scope_free (void *) attribute_hidden
;
1064 /* Add module to slot information data. */
1065 extern void _dl_add_to_slotinfo (struct link_map
*l
) attribute_hidden
;
1067 /* Update slot information data for at least the generation of the
1068 module with the given index. */
1069 extern struct link_map
*_dl_update_slotinfo (unsigned long int req_modid
)
1072 /* Look up the module's TLS block as for __tls_get_addr,
1073 but never touch anything. Return null if it's not allocated yet. */
1074 extern void *_dl_tls_get_addr_soft (struct link_map
*l
) attribute_hidden
;
1076 extern int _dl_addr_inside_object (struct link_map
*l
, const ElfW(Addr
) addr
)
1077 internal_function attribute_hidden
;
1079 /* Show show of an object. */
1080 extern void _dl_show_scope (struct link_map
*new, int from
)
1083 extern struct link_map
*_dl_find_dso_for_object (const ElfW(Addr
) addr
)
1085 rtld_hidden_proto (_dl_find_dso_for_object
)
1087 /* Initialization which is normally done by the dynamic linker. */
1088 extern void _dl_non_dynamic_init (void) internal_function
;
1090 /* Used by static binaries to check the auxiliary vector. */
1091 extern void _dl_aux_init (ElfW(auxv_t
) *av
) internal_function
;
1096 #endif /* ldsodefs.h */