1/* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _LDSODEFS_H
20#define _LDSODEFS_H 1
21
22#include <features.h>
23
24#include <stdbool.h>
25#define __need_size_t
26#define __need_NULL
27#include <stddef.h>
28#include <string.h>
29#include <stdint.h>
30
31#include <elf.h>
32#include <dlfcn.h>
33#include <fpu_control.h>
34#include <sys/mman.h>
35#include <link.h>
36#include <dl-lookupcfg.h>
37#include <dl-sysdep.h>
38#include <libc-lock.h>
39#include <hp-timing.h>
40#include <tls.h>
41
42__BEGIN_DECLS
43
44#define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
45#define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
46 + DT_EXTRANUM + DT_VALTAGIDX (tag))
47#define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
48 + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
49
50/* We use this macro to refer to ELF types independent of the native wordsize.
51 `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
52#define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
53
54/* All references to the value of l_info[DT_PLTGOT],
55 l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
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)
62#else
63# define D_PTR(map, i) (map)->i->d_un.d_ptr
64#endif
65
66/* Result of the lookup functions and how to retrieve the base address. */
67typedef struct link_map *lookup_t;
68#define LOOKUP_VALUE(map) map
69#define LOOKUP_VALUE_ADDRESS(map) ((map) ? (map)->l_addr : 0)
70
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)) ()
81#endif
82
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))
90
91/* Unmap a loaded object, called by _dl_close (). */
92#ifndef DL_UNMAP_IS_SPECIAL
93# define DL_UNMAP(map) _dl_unmap_segments (map)
94#endif
95
96/* By default we do not need special support to initialize DSOs loaded
97 by statically linked binaries. */
98#ifndef DL_STATIC_INIT
99# define DL_STATIC_INIT(map)
100#endif
101
102/* Reloc type classes as returned by elf_machine_type_class().
103 ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
104 some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
105 satisfied by any symbol in the executable. Some architectures do
106 not support copy relocations. In this case we define the macro to
107 zero so that the code for handling them gets automatically optimized
108 out. ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA means address of protected
109 data defined in the shared library may be external, i.e., due to copy
110 relocation. */
111#define ELF_RTYPE_CLASS_PLT 1
112#ifndef DL_NO_COPY_RELOCS
113# define ELF_RTYPE_CLASS_COPY 2
114#else
115# define ELF_RTYPE_CLASS_COPY 0
116#endif
117/* If DL_EXTERN_PROTECTED_DATA is defined, address of protected data
118 defined in the shared library may be external, i.e., due to copy
119 relocation. */
120#ifdef DL_EXTERN_PROTECTED_DATA
121# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 4
122#else
123# define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 0
124#endif
125
126/* ELF uses the PF_x macros to specify the segment permissions, mmap
127 uses PROT_xxx. In most cases the three macros have the values 1, 2,
128 and 3 but not in a matching order. The following macros allows
129 converting from the PF_x values to PROT_xxx values. */
130#define PF_TO_PROT \
131 ((PROT_READ << (PF_R * 4)) \
132 | (PROT_WRITE << (PF_W * 4)) \
133 | (PROT_EXEC << (PF_X * 4)) \
134 | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
135 | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
136 | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
137 | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
138
139/* The filename itself, or the main program name, if available. */
140#define DSO_FILENAME(name) ((name)[0] ? (name) \
141 : (rtld_progname ?: "<main program>"))
142
143#define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
144
145/* For the version handling we need an array with only names and their
146 hash values. */
147struct r_found_version
148 {
149 const char *name;
150 ElfW(Word) hash;
151
152 int hidden;
153 const char *filename;
154 };
155
156/* We want to cache information about the searches for shared objects. */
157
158enum r_dir_status { unknown, nonexisting, existing };
159
160struct r_search_path_elem
161 {
162 /* This link is only used in the `all_dirs' member of `r_search_path'. */
163 struct r_search_path_elem *next;
164
165 /* Strings saying where the definition came from. */
166 const char *what;
167 const char *where;
168
169 /* Basename for this search path element. The string must end with
170 a slash character. */
171 const char *dirname;
172 size_t dirnamelen;
173
174 enum r_dir_status status[0];
175 };
176
177struct r_strlenpair
178 {
179 const char *str;
180 size_t len;
181 };
182
183
184/* A data structure for a simple single linked list of strings. */
185struct libname_list
186 {
187 const char *name; /* Name requested (before search). */
188 struct libname_list *next; /* Link to next name for this object. */
189 int dont_free; /* Flag whether this element should be freed
190 if the object is not entirely unloaded. */
191 };
192
193
194/* Bit masks for the objects which valid callers can come from to
195 functions with restricted interface. */
196enum allowmask
197 {
198 allow_libc = 1,
199 allow_libdl = 2,
200 allow_libpthread = 4,
201 allow_ldso = 8
202 };
203
204
205struct audit_ifaces
206{
207 void (*activity) (uintptr_t *, unsigned int);
208 char *(*objsearch) (const char *, uintptr_t *, unsigned int);
209 unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
210 void (*preinit) (uintptr_t *);
211 union
212 {
213 uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
214 uintptr_t *, unsigned int *, const char *);
215 uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
216 uintptr_t *, unsigned int *, const char *);
217 };
218 union
219 {
220#ifdef ARCH_PLTENTER_MEMBERS
221 ARCH_PLTENTER_MEMBERS;
222#endif
223 };
224 union
225 {
226#ifdef ARCH_PLTEXIT_MEMBERS
227 ARCH_PLTEXIT_MEMBERS;
228#endif
229 };
230 unsigned int (*objclose) (uintptr_t *);
231
232 struct audit_ifaces *next;
233};
234
235
236/* Test whether given NAME matches any of the names of the given object. */
237extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
238 internal_function attribute_hidden;
239
240/* Compute next higher prime number. */
241extern unsigned long int _dl_higher_prime_number (unsigned long int n)
242 internal_function attribute_hidden;
243
244/* Function used as argument for `_dl_receive_error' function. The
245 arguments are the error code, error string, and the objname the
246 error occurred in. */
247typedef void (*receiver_fct) (int, const char *, const char *);
248
249/* Internal functions of the run-time dynamic linker.
250 These can be accessed if you link again the dynamic linker
251 as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
252 but are not normally of interest to user programs.
253
254 The `-ldl' library functions in <dlfcn.h> provide a simple
255 user interface to run-time dynamic linking. */
256
257
258#ifndef SHARED
259# define EXTERN extern
260# define GL(name) _##name
261#else
262# define EXTERN
263# if IS_IN (rtld)
264# define GL(name) _rtld_local._##name
265# else
266# define GL(name) _rtld_global._##name
267# endif
268struct rtld_global
269{
270#endif
271 /* Don't change the order of the following elements. 'dl_loaded'
272 must remain the first element. Forever. */
273
274/* Non-shared code has no support for multiple namespaces. */
275#ifdef SHARED
276# define DL_NNS 16
277#else
278# define DL_NNS 1
279#endif
280 EXTERN struct link_namespaces
281 {
282 /* A pointer to the map for the main map. */
283 struct link_map *_ns_loaded;
284 /* Number of object in the _dl_loaded list. */
285 unsigned int _ns_nloaded;
286 /* Direct pointer to the searchlist of the main object. */
287 struct r_scope_elem *_ns_main_searchlist;
288 /* This is zero at program start to signal that the global scope map is
289 allocated by rtld. Later it keeps the size of the map. It might be
290 reset if in _dl_close if the last global object is removed. */
291 size_t _ns_global_scope_alloc;
292 /* Search table for unique objects. */
293 struct unique_sym_table
294 {
295 __rtld_lock_define_recursive (, lock)
296 struct unique_sym
297 {
298 uint32_t hashval;
299 const char *name;
300 const ElfW(Sym) *sym;
301 const struct link_map *map;
302 } *entries;
303 size_t size;
304 size_t n_elements;
305 void (*free) (void *);
306 } _ns_unique_sym_table;
307 /* Keep track of changes to each namespace' list. */
308 struct r_debug _ns_debug;
309 } _dl_ns[DL_NNS];
310 /* One higher than index of last used namespace. */
311 EXTERN size_t _dl_nns;
312
313 /* During the program run we must not modify the global data of
314 loaded shared object simultanously in two threads. Therefore we
315 protect `_dl_open' and `_dl_close' in dl-close.c.
316
317 This must be a recursive lock since the initializer function of
318 the loaded object might as well require a call to this function.
319 At this time it is not anymore a problem to modify the tables. */
320 __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
321 /* This lock is used to keep __dl_iterate_phdr from inspecting the
322 list of loaded objects while an object is added to or removed
323 from that list. */
324 __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
325
326 /* Incremented whenever something may have been added to dl_loaded. */
327 EXTERN unsigned long long _dl_load_adds;
328
329 /* The object to be initialized first. */
330 EXTERN struct link_map *_dl_initfirst;
331
332#if HP_SMALL_TIMING_AVAIL
333 /* Start time on CPU clock. */
334 EXTERN hp_timing_t _dl_cpuclock_offset;
335#endif
336
337 /* Map of shared object to be profiled. */
338 EXTERN struct link_map *_dl_profile_map;
339
340 /* Counters for the number of relocations performed. */
341 EXTERN unsigned long int _dl_num_relocations;
342 EXTERN unsigned long int _dl_num_cache_relocations;
343
344 /* List of search directories. */
345 EXTERN struct r_search_path_elem *_dl_all_dirs;
346
347#ifdef _LIBC_REENTRANT
348 EXTERN void **(*_dl_error_catch_tsd) (void) __attribute__ ((const));
349#endif
350
351 /* Structure describing the dynamic linker itself. We need to
352 reserve memory for the data the audit libraries need. */
353 EXTERN struct link_map _dl_rtld_map;
354#ifdef SHARED
355 struct auditstate audit_data[DL_NNS];
356#endif
357
358#if defined SHARED && defined _LIBC_REENTRANT \
359 && defined __rtld_lock_default_lock_recursive
360 EXTERN void (*_dl_rtld_lock_recursive) (void *);
361 EXTERN void (*_dl_rtld_unlock_recursive) (void *);
362#endif
363
364 /* If loading a shared object requires that we make the stack executable
365 when it was not, we do it by calling this function.
366 It returns an errno code or zero on success. */
367 EXTERN int (*_dl_make_stack_executable_hook) (void **) internal_function;
368
369 /* Prevailing state of the stack, PF_X indicating it's executable. */
370 EXTERN ElfW(Word) _dl_stack_flags;
371
372 /* Flag signalling whether there are gaps in the module ID allocation. */
373 EXTERN bool _dl_tls_dtv_gaps;
374 /* Highest dtv index currently needed. */
375 EXTERN size_t _dl_tls_max_dtv_idx;
376 /* Information about the dtv slots. */
377 EXTERN struct dtv_slotinfo_list
378 {
379 size_t len;
380 struct dtv_slotinfo_list *next;
381 struct dtv_slotinfo
382 {
383 size_t gen;
384 struct link_map *map;
385 } slotinfo[0];
386 } *_dl_tls_dtv_slotinfo_list;
387 /* Number of modules in the static TLS block. */
388 EXTERN size_t _dl_tls_static_nelem;
389 /* Size of the static TLS block. */
390 EXTERN size_t _dl_tls_static_size;
391 /* Size actually allocated in the static TLS block. */
392 EXTERN size_t _dl_tls_static_used;
393 /* Alignment requirement of the static TLS block. */
394 EXTERN size_t _dl_tls_static_align;
395
396/* Number of additional entries in the slotinfo array of each slotinfo
397 list element. A large number makes it almost certain take we never
398 have to iterate beyond the first element in the slotinfo list. */
399#define TLS_SLOTINFO_SURPLUS (62)
400
401/* Number of additional slots in the dtv allocated. */
402#define DTV_SURPLUS (14)
403
404 /* Initial dtv of the main thread, not allocated with normal malloc. */
405 EXTERN void *_dl_initial_dtv;
406 /* Generation counter for the dtv. */
407 EXTERN size_t _dl_tls_generation;
408
409 EXTERN void (*_dl_init_static_tls) (struct link_map *);
410
411 EXTERN void (*_dl_wait_lookup_done) (void);
412
413 /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
414 EXTERN struct dl_scope_free_list
415 {
416 size_t count;
417 void *list[50];
418 } *_dl_scope_free_list;
419#ifdef SHARED
420};
421# define __rtld_global_attribute__
422# if IS_IN (rtld)
423# ifdef HAVE_SDATA_SECTION
424# define __rtld_local_attribute__ \
425 __attribute__ ((visibility ("hidden"), section (".sdata")))
426# undef __rtld_global_attribute__
427# define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
428# else
429# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
430# endif
431extern struct rtld_global _rtld_local __rtld_local_attribute__;
432# undef __rtld_local_attribute__
433# endif
434extern struct rtld_global _rtld_global __rtld_global_attribute__;
435# undef __rtld_global_attribute__
436#endif
437
438#ifndef SHARED
439# define GLRO(name) _##name
440#else
441# if IS_IN (rtld)
442# define GLRO(name) _rtld_local_ro._##name
443# else
444# define GLRO(name) _rtld_global_ro._##name
445# endif
446struct rtld_global_ro
447{
448#endif
449
450 /* If nonzero the appropriate debug information is printed. */
451 EXTERN int _dl_debug_mask;
452#define DL_DEBUG_LIBS (1 << 0)
453#define DL_DEBUG_IMPCALLS (1 << 1)
454#define DL_DEBUG_BINDINGS (1 << 2)
455#define DL_DEBUG_SYMBOLS (1 << 3)
456#define DL_DEBUG_VERSIONS (1 << 4)
457#define DL_DEBUG_RELOC (1 << 5)
458#define DL_DEBUG_FILES (1 << 6)
459#define DL_DEBUG_STATISTICS (1 << 7)
460#define DL_DEBUG_UNUSED (1 << 8)
461#define DL_DEBUG_SCOPES (1 << 9)
462/* These two are used only internally. */
463#define DL_DEBUG_HELP (1 << 10)
464#define DL_DEBUG_PRELINK (1 << 11)
465
466 /* OS version. */
467 EXTERN unsigned int _dl_osversion;
468 /* Platform name. */
469 EXTERN const char *_dl_platform;
470 EXTERN size_t _dl_platformlen;
471
472 /* Cached value of `getpagesize ()'. */
473 EXTERN size_t _dl_pagesize;
474
475 /* Do we read from ld.so.cache? */
476 EXTERN int _dl_inhibit_cache;
477
478 /* Copy of the content of `_dl_main_searchlist' at startup time. */
479 EXTERN struct r_scope_elem _dl_initial_searchlist;
480
481 /* CLK_TCK as reported by the kernel. */
482 EXTERN int _dl_clktck;
483
484 /* If nonzero print warnings messages. */
485 EXTERN int _dl_verbose;
486
487 /* File descriptor to write debug messages to. */
488 EXTERN int _dl_debug_fd;
489
490 /* Do we do lazy relocations? */
491 EXTERN int _dl_lazy;
492
493 /* Nonzero if runtime lookups should not update the .got/.plt. */
494 EXTERN int _dl_bind_not;
495
496 /* Nonzero if references should be treated as weak during runtime
497 linking. */
498 EXTERN int _dl_dynamic_weak;
499
500 /* Default floating-point control word. */
501 EXTERN fpu_control_t _dl_fpu_control;
502
503 /* Expected cache ID. */
504 EXTERN int _dl_correct_cache_id;
505
506 /* Mask for hardware capabilities that are available. */
507 EXTERN uint64_t _dl_hwcap;
508
509 /* Mask for important hardware capabilities we honour. */
510 EXTERN uint64_t _dl_hwcap_mask;
511
512 /* Pointer to the auxv list supplied to the program at startup. */
513 EXTERN ElfW(auxv_t) *_dl_auxv;
514
515 /* Get architecture specific definitions. */
516#define PROCINFO_DECL
517#ifndef PROCINFO_CLASS
518# define PROCINFO_CLASS EXTERN
519#endif
520#include <dl-procinfo.c>
521
522 /* Names of shared object for which the RPATH should be ignored. */
523 EXTERN const char *_dl_inhibit_rpath;
524
525 /* Location of the binary. */
526 EXTERN const char *_dl_origin_path;
527
528 /* -1 if the dynamic linker should honor library load bias,
529 0 if not, -2 use the default (honor biases for normal
530 binaries, don't honor for PIEs). */
531 EXTERN ElfW(Addr) _dl_use_load_bias;
532
533 /* Name of the shared object to be profiled (if any). */
534 EXTERN const char *_dl_profile;
535 /* Filename of the output file. */
536 EXTERN const char *_dl_profile_output;
537 /* Name of the object we want to trace the prelinking. */
538 EXTERN const char *_dl_trace_prelink;
539 /* Map of shared object to be prelink traced. */
540 EXTERN struct link_map *_dl_trace_prelink_map;
541
542 /* All search directories defined at startup. */
543 EXTERN struct r_search_path_elem *_dl_init_all_dirs;
544
545#ifdef NEED_DL_SYSINFO
546 /* Syscall handling improvements. This is very specific to x86. */
547 EXTERN uintptr_t _dl_sysinfo;
548#endif
549
550#ifdef NEED_DL_SYSINFO_DSO
551 /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
552 This points to its ELF header. */
553 EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
554
555 /* At startup time we set up the normal DSO data structure for it,
556 and this points to it. */
557 EXTERN struct link_map *_dl_sysinfo_map;
558#endif
559
560 /* Mask for more hardware capabilities that are available on some
561 platforms. */
562 EXTERN uint64_t _dl_hwcap2;
563
564#ifdef SHARED
565 /* We add a function table to _rtld_global which is then used to
566 call the function instead of going through the PLT. The result
567 is that we can avoid exporting the functions and we do not jump
568 PLT relocations in libc.so. */
569 void (*_dl_debug_printf) (const char *, ...)
570 __attribute__ ((__format__ (__printf__, 1, 2)));
571 int (internal_function *_dl_catch_error) (const char **, const char **,
572 bool *, void (*) (void *), void *);
573 void (internal_function *_dl_signal_error) (int, const char *, const char *,
574 const char *);
575 void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
576 lookup_t (internal_function *_dl_lookup_symbol_x) (const char *,
577 struct link_map *,
578 const ElfW(Sym) **,
579 struct r_scope_elem *[],
580 const struct r_found_version *,
581 int, int,
582 struct link_map *);
583 int (*_dl_check_caller) (const void *, enum allowmask);
584 void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
585 Lmid_t nsid, int argc, char *argv[], char *env[]);
586 void (*_dl_close) (void *map);
587 void *(*_dl_tls_get_addr_soft) (struct link_map *);
588#ifdef HAVE_DL_DISCOVER_OSVERSION
589 int (*_dl_discover_osversion) (void);
590#endif
591
592 /* List of auditing interfaces. */
593 struct audit_ifaces *_dl_audit;
594 unsigned int _dl_naudit;
595};
596# define __rtld_global_attribute__
597# if IS_IN (rtld)
598# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
599extern struct rtld_global_ro _rtld_local_ro
600 attribute_relro __rtld_local_attribute__;
601extern struct rtld_global_ro _rtld_global_ro
602 attribute_relro __rtld_global_attribute__;
603# undef __rtld_local_attribute__
604# else
605/* We cheat a bit here. We declare the variable as as const even
606 though it is at startup. */
607extern const struct rtld_global_ro _rtld_global_ro
608 attribute_relro __rtld_global_attribute__;
609# endif
610# undef __rtld_global_attribute__
611#endif
612#undef EXTERN
613
614#ifndef SHARED
615/* dl-support.c defines these and initializes them early on. */
616extern const ElfW(Phdr) *_dl_phdr;
617extern size_t _dl_phnum;
618#endif
619
620#if IS_IN (rtld)
621/* This is the initial value of GL(dl_error_catch_tsd).
622 A non-TLS libpthread will change it. */
623extern void **_dl_initial_error_catch_tsd (void) __attribute__ ((const))
624 attribute_hidden;
625#endif
626
627/* This is the initial value of GL(dl_make_stack_executable_hook).
628 A threads library can change it. */
629extern int _dl_make_stack_executable (void **stack_endp) internal_function;
630rtld_hidden_proto (_dl_make_stack_executable)
631
632/* Variable pointing to the end of the stack (or close to it). This value
633 must be constant over the runtime of the application. Some programs
634 might use the variable which results in copy relocations on some
635 platforms. But this does not matter, ld.so can always use the local
636 copy. */
637extern void *__libc_stack_end
638#ifndef LIBC_STACK_END_NOT_RELRO
639 attribute_relro
640#endif
641 ;
642rtld_hidden_proto (__libc_stack_end)
643
644/* Parameters passed to the dynamic linker. */
645extern int _dl_argc attribute_hidden attribute_relro;
646extern char **_dl_argv
647#ifndef DL_ARGV_NOT_RELRO
648 attribute_relro
649#endif
650 ;
651rtld_hidden_proto (_dl_argv)
652#if IS_IN (rtld)
653extern unsigned int _dl_skip_args attribute_hidden
654# ifndef DL_ARGV_NOT_RELRO
655 attribute_relro
656# endif
657 ;
658extern unsigned int _dl_skip_args_internal attribute_hidden
659# ifndef DL_ARGV_NOT_RELRO
660 attribute_relro
661# endif
662 ;
663#endif
664#define rtld_progname _dl_argv[0]
665
666/* Flag set at startup and cleared when the last initializer has run. */
667extern int _dl_starting_up;
668weak_extern (_dl_starting_up)
669rtld_hidden_proto (_dl_starting_up)
670
671/* Random data provided by the kernel. */
672extern void *_dl_random attribute_hidden attribute_relro;
673
674/* OS-dependent function to open the zero-fill device. */
675extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
676
677
678/* Write message on the debug file descriptor. The parameters are
679 interpreted as for a `printf' call. All the lines start with a
680 tag showing the PID. */
681extern void _dl_debug_printf (const char *fmt, ...)
682 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
683
684/* Write message on the debug file descriptor. The parameters are
685 interpreted as for a `printf' call. All the lines buf the first
686 start with a tag showing the PID. */
687extern void _dl_debug_printf_c (const char *fmt, ...)
688 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
689
690
691/* Write a message on the specified descriptor FD. The parameters are
692 interpreted as for a `printf' call. */
693extern void _dl_dprintf (int fd, const char *fmt, ...)
694 __attribute__ ((__format__ (__printf__, 2, 3)))
695 attribute_hidden;
696
697/* Write a message on the specified descriptor standard output. The
698 parameters are interpreted as for a `printf' call. */
699#define _dl_printf(fmt, args...) \
700 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
701
702/* Write a message on the specified descriptor standard error. The
703 parameters are interpreted as for a `printf' call. */
704#define _dl_error_printf(fmt, args...) \
705 _dl_dprintf (STDERR_FILENO, fmt, ##args)
706
707/* Write a message on the specified descriptor standard error and exit
708 the program. The parameters are interpreted as for a `printf' call. */
709#define _dl_fatal_printf(fmt, args...) \
710 do \
711 { \
712 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
713 _exit (127); \
714 } \
715 while (1)
716
717
718/* This function is called by all the internal dynamic linker functions
719 when they encounter an error. ERRCODE is either an `errno' code or
720 zero; OBJECT is the name of the problematical shared object, or null if
721 it is a general problem; ERRSTRING is a string describing the specific
722 problem. */
723extern void _dl_signal_error (int errcode, const char *object,
724 const char *occurred, const char *errstring)
725 internal_function __attribute__ ((__noreturn__)) attribute_hidden;
726
727/* Like _dl_signal_error, but may return when called in the context of
728 _dl_receive_error. */
729extern void _dl_signal_cerror (int errcode, const char *object,
730 const char *occation, const char *errstring)
731 internal_function attribute_hidden;
732
733/* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
734 `_dl_catch_error' the operation is resumed after the OPERATE
735 function returns.
736 ARGS is passed as argument to OPERATE. */
737extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
738 void *args)
739 internal_function attribute_hidden;
740
741/* Call OPERATE, catching errors from `dl_signal_error'. If there is no
742 error, *ERRSTRING is set to null. If there is an error, *ERRSTRING is
743 set to a string constructed from the strings passed to _dl_signal_error,
744 and the error code passed is the return value and *OBJNAME is set to
745 the object name which experienced the problems. ERRSTRING if nonzero
746 points to a malloc'ed string which the caller has to free after use.
747 ARGS is passed as argument to OPERATE. MALLOCEDP is set to true only
748 if the returned string is allocated using the libc's malloc. */
749extern int _dl_catch_error (const char **objname, const char **errstring,
750 bool *mallocedp, void (*operate) (void *),
751 void *args)
752 internal_function attribute_hidden;
753
754/* Open the shared object NAME and map in its segments.
755 LOADER's DT_RPATH is used in searching for NAME.
756 If the object is already opened, returns its existing map. */
757extern struct link_map *_dl_map_object (struct link_map *loader,
758 const char *name,
759 int type, int trace_mode, int mode,
760 Lmid_t nsid)
761 internal_function attribute_hidden;
762
763/* Call _dl_map_object on the dependencies of MAP, and set up
764 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
765 loaded objects that will be inserted into MAP->l_searchlist after MAP
766 but before its dependencies. */
767extern void _dl_map_object_deps (struct link_map *map,
768 struct link_map **preloads,
769 unsigned int npreloads, int trace_mode,
770 int open_mode)
771 internal_function attribute_hidden;
772
773/* Cache the locations of MAP's hash table. */
774extern void _dl_setup_hash (struct link_map *map)
775 internal_function attribute_hidden;
776
777
778/* Collect the directories in the search path for LOADER's dependencies.
779 The data structure is defined in <dlfcn.h>. If COUNTING is true,
780 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
781 by a previous call with COUNTING set, and SI must point to SI->dls_size
782 bytes to be used in filling in the result. */
783extern void _dl_rtld_di_serinfo (struct link_map *loader,
784 Dl_serinfo *si, bool counting)
785 internal_function;
786
787
788/* Search loaded objects' symbol tables for a definition of the symbol
789 referred to by UNDEF. *SYM is the symbol table entry containing the
790 reference; it is replaced with the defining symbol, and the base load
791 address of the defining object is returned. SYMBOL_SCOPE is a
792 null-terminated list of object scopes to search; each object's
793 l_searchlist (i.e. the segment of the dependency tree starting at that
794 object) is searched in turn. REFERENCE_NAME should name the object
795 containing the reference; it is used in error messages.
796 TYPE_CLASS describes the type of symbol we are looking for. */
797enum
798 {
799 /* If necessary add dependency between user and provider object. */
800 DL_LOOKUP_ADD_DEPENDENCY = 1,
801 /* Return most recent version instead of default version for
802 unversioned lookup. */
803 DL_LOOKUP_RETURN_NEWEST = 2,
804 /* Set if dl_lookup* called with GSCOPE lock held. */
805 DL_LOOKUP_GSCOPE_LOCK = 4,
806 };
807
808/* Lookup versioned symbol. */
809extern lookup_t _dl_lookup_symbol_x (const char *undef,
810 struct link_map *undef_map,
811 const ElfW(Sym) **sym,
812 struct r_scope_elem *symbol_scope[],
813 const struct r_found_version *version,
814 int type_class, int flags,
815 struct link_map *skip_map)
816 internal_function attribute_hidden;
817
818
819/* Look up symbol NAME in MAP's scope and return its run-time address. */
820extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name)
821 internal_function;
822
823/* Add the new link_map NEW to the end of the namespace list. */
824extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
825 internal_function attribute_hidden;
826
827/* Allocate a `struct link_map' for a new object being loaded. */
828extern struct link_map *_dl_new_object (char *realname, const char *libname,
829 int type, struct link_map *loader,
830 int mode, Lmid_t nsid)
831 internal_function attribute_hidden;
832
833/* Relocate the given object (if it hasn't already been).
834 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
835 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
836extern void _dl_relocate_object (struct link_map *map,
837 struct r_scope_elem *scope[],
838 int reloc_mode, int consider_profiling)
839 attribute_hidden;
840
841/* Protect PT_GNU_RELRO area. */
842extern void _dl_protect_relro (struct link_map *map)
843 internal_function attribute_hidden;
844
845/* Call _dl_signal_error with a message about an unhandled reloc type.
846 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
847 PLT is nonzero if this was a PLT reloc; it just affects the message. */
848extern void _dl_reloc_bad_type (struct link_map *map,
849 unsigned int type, int plt)
850 internal_function attribute_hidden __attribute__ ((__noreturn__));
851
852/* Resolve conflicts if prelinking. */
853extern void _dl_resolve_conflicts (struct link_map *l,
854 ElfW(Rela) *conflict,
855 ElfW(Rela) *conflictend)
856 attribute_hidden;
857
858/* Check the version dependencies of all objects available through
859 MAP. If VERBOSE print some more diagnostics. */
860extern int _dl_check_all_versions (struct link_map *map, int verbose,
861 int trace_mode)
862 internal_function attribute_hidden;
863
864/* Check the version dependencies for MAP. If VERBOSE print some more
865 diagnostics. */
866extern int _dl_check_map_versions (struct link_map *map, int verbose,
867 int trace_mode)
868 internal_function attribute_hidden;
869
870/* Initialize the object in SCOPE by calling the constructors with
871 ARGC, ARGV, and ENV as the parameters. */
872extern void _dl_init (struct link_map *main_map, int argc, char **argv,
873 char **env) internal_function attribute_hidden;
874
875/* Call the finalizer functions of all shared objects whose
876 initializer functions have completed. */
877extern void _dl_fini (void) internal_function;
878
879/* Sort array MAPS according to dependencies of the contained objects. */
880extern void _dl_sort_fini (struct link_map **maps, size_t nmaps, char *used,
881 Lmid_t ns)
882 internal_function attribute_hidden;
883
884/* The dynamic linker calls this function before and having changing
885 any shared object mappings. The `r_state' member of `struct r_debug'
886 says what change is taking place. This function's address is
887 the value of the `r_brk' member. */
888extern void _dl_debug_state (void);
889rtld_hidden_proto (_dl_debug_state)
890
891/* Initialize `struct r_debug' if it has not already been done. The
892 argument is the run-time load address of the dynamic linker, to be put
893 in the `r_ldbase' member. Returns the address of the structure. */
894extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
895 internal_function attribute_hidden;
896
897/* Initialize the basic data structure for the search paths. */
898extern void _dl_init_paths (const char *library_path)
899 internal_function attribute_hidden;
900
901/* Gather the information needed to install the profiling tables and start
902 the timers. */
903extern void _dl_start_profile (void) internal_function attribute_hidden;
904
905/* The actual functions used to keep book on the calls. */
906extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
907rtld_hidden_proto (_dl_mcount)
908
909/* This function is simply a wrapper around the _dl_mcount function
910 which does not require a FROMPC parameter since this is the
911 calling function. */
912extern void _dl_mcount_wrapper (void *selfpc);
913
914/* Show the members of the auxiliary array passed up from the kernel. */
915extern void _dl_show_auxv (void)
916 internal_function attribute_hidden;
917
918/* Return all environment variables starting with `LD_', one after the
919 other. */
920extern char *_dl_next_ld_env_entry (char ***position)
921 internal_function attribute_hidden;
922
923/* Return an array with the names of the important hardware capabilities. */
924extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform,
925 size_t paltform_len,
926 size_t *sz,
927 size_t *max_capstrlen)
928 internal_function attribute_hidden;
929
930/* Look up NAME in ld.so.cache and return the file name stored there,
931 or null if none is found. Caller must free returned string. */
932extern char *_dl_load_cache_lookup (const char *name)
933 internal_function attribute_hidden;
934
935/* If the system does not support MAP_COPY we cannot leave the file open
936 all the time since this would create problems when the file is replaced.
937 Therefore we provide this function to close the file and open it again
938 once needed. */
939extern void _dl_unload_cache (void) attribute_hidden;
940
941/* System-dependent function to read a file's whole contents in the
942 most convenient manner available. *SIZEP gets the size of the
943 file. On error MAP_FAILED is returned. */
944extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
945 int prot)
946 internal_function attribute_hidden;
947
948/* System-specific function to do initial startup for the dynamic linker.
949 After this, file access calls and getenv must work. This is responsible
950 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
951 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
952extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
953 void (*dl_main) (const ElfW(Phdr) *phdr,
954 ElfW(Word) phnum,
955 ElfW(Addr) *user_entry,
956 ElfW(auxv_t) *auxv))
957 attribute_hidden;
958
959extern void _dl_sysdep_start_cleanup (void)
960 internal_function attribute_hidden;
961
962
963/* Determine next available module ID. */
964extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden;
965
966/* Count the modules with TLS segments. */
967extern size_t _dl_count_modids (void) internal_function attribute_hidden;
968
969/* Calculate offset of the TLS blocks in the static TLS block. */
970extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden;
971
972/* Set up the data structures for TLS, when they were not set up at startup.
973 Returns nonzero on malloc failure.
974 This is called from _dl_map_object_from_fd or by libpthread. */
975extern int _dl_tls_setup (void) internal_function;
976rtld_hidden_proto (_dl_tls_setup)
977
978/* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
979extern void *_dl_allocate_tls (void *mem) internal_function;
980rtld_hidden_proto (_dl_allocate_tls)
981
982/* Get size and alignment requirements of the static TLS block. */
983extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp)
984 internal_function;
985
986extern void _dl_allocate_static_tls (struct link_map *map)
987 internal_function attribute_hidden;
988
989/* These are internal entry points to the two halves of _dl_allocate_tls,
990 only used within rtld.c itself at startup time. */
991extern void *_dl_allocate_tls_storage (void)
992 internal_function attribute_hidden;
993extern void *_dl_allocate_tls_init (void *) internal_function;
994rtld_hidden_proto (_dl_allocate_tls_init)
995
996/* Deallocate memory allocated with _dl_allocate_tls. */
997extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb) internal_function;
998rtld_hidden_proto (_dl_deallocate_tls)
999
1000extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
1001
1002/* Find origin of the executable. */
1003extern const char *_dl_get_origin (void) attribute_hidden;
1004
1005/* Count DSTs. */
1006extern size_t _dl_dst_count (const char *name, int is_path) attribute_hidden;
1007
1008/* Substitute DST values. */
1009extern char *_dl_dst_substitute (struct link_map *l, const char *name,
1010 char *result, int is_path) attribute_hidden;
1011
1012/* Check validity of the caller. */
1013extern int _dl_check_caller (const void *caller, enum allowmask mask)
1014 attribute_hidden;
1015
1016/* Open the shared object NAME, relocate it, and run its initializer if it
1017 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1018 the object is already opened, returns its existing map. */
1019extern void *_dl_open (const char *name, int mode, const void *caller,
1020 Lmid_t nsid, int argc, char *argv[], char *env[])
1021 attribute_hidden;
1022
1023/* Free or queue for freeing scope OLD. If other threads might be
1024 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1025 old scope, OLD can't be freed until no thread is using it. */
1026extern int _dl_scope_free (void *) attribute_hidden;
1027
1028/* Add module to slot information data. */
1029extern void _dl_add_to_slotinfo (struct link_map *l) attribute_hidden;
1030
1031/* Update slot information data for at least the generation of the
1032 module with the given index. */
1033extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid)
1034 attribute_hidden;
1035
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. */
1038extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
1039
1040extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
1041 internal_function attribute_hidden;
1042
1043/* Show show of an object. */
1044extern void _dl_show_scope (struct link_map *new, int from)
1045 attribute_hidden;
1046
1047extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr)
1048 internal_function;
1049rtld_hidden_proto (_dl_find_dso_for_object)
1050
1051/* Initialization which is normally done by the dynamic linker. */
1052extern void _dl_non_dynamic_init (void) internal_function;
1053
1054/* Used by static binaries to check the auxiliary vector. */
1055extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function;
1056
1057
1058__END_DECLS
1059
1060#endif /* ldsodefs.h */
1061