blob: 7a0fe8dbe40f85cd682e698ba8401954275dbd11 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001/* Run-time dynamic linker data structures for loaded ELF shared objects.
2 Copyright (C) 1995-2015 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 <bits/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;
239
240/* Compute next higher prime number. */
241extern unsigned long int _dl_higher_prime_number (unsigned long int n)
242 internal_function;
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 /* 0 if internal pointer values should not be guarded, 1 if they should. */
597 EXTERN int _dl_pointer_guard;
598};
599# define __rtld_global_attribute__
600# if IS_IN (rtld)
601# define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
602extern struct rtld_global_ro _rtld_local_ro
603 attribute_relro __rtld_local_attribute__;
604extern struct rtld_global_ro _rtld_global_ro
605 attribute_relro __rtld_global_attribute__;
606# undef __rtld_local_attribute__
607# else
608/* We cheat a bit here. We declare the variable as as const even
609 though it is at startup. */
610extern const struct rtld_global_ro _rtld_global_ro
611 attribute_relro __rtld_global_attribute__;
612# endif
613# undef __rtld_global_attribute__
614#endif
615#undef EXTERN
616
617#ifndef SHARED
618/* dl-support.c defines these and initializes them early on. */
619extern const ElfW(Phdr) *_dl_phdr;
620extern size_t _dl_phnum;
621#endif
622
623#if IS_IN (rtld)
624/* This is the initial value of GL(dl_error_catch_tsd).
625 A non-TLS libpthread will change it. */
626extern void **_dl_initial_error_catch_tsd (void) __attribute__ ((const))
627 attribute_hidden;
628#endif
629
630/* This is the initial value of GL(dl_make_stack_executable_hook).
631 A threads library can change it. */
632extern int _dl_make_stack_executable (void **stack_endp) internal_function;
633rtld_hidden_proto (_dl_make_stack_executable)
634
635/* Variable pointing to the end of the stack (or close to it). This value
636 must be constant over the runtime of the application. Some programs
637 might use the variable which results in copy relocations on some
638 platforms. But this does not matter, ld.so can always use the local
639 copy. */
640extern void *__libc_stack_end
641#ifndef LIBC_STACK_END_NOT_RELRO
642 attribute_relro
643#endif
644 ;
645rtld_hidden_proto (__libc_stack_end)
646
647/* Parameters passed to the dynamic linker. */
648extern int _dl_argc attribute_hidden attribute_relro;
649extern char **_dl_argv
650#ifndef DL_ARGV_NOT_RELRO
651 attribute_relro
652#endif
653 ;
654rtld_hidden_proto (_dl_argv)
655#if IS_IN (rtld)
656extern unsigned int _dl_skip_args attribute_hidden
657# ifndef DL_ARGV_NOT_RELRO
658 attribute_relro
659# endif
660 ;
661extern unsigned int _dl_skip_args_internal attribute_hidden
662# ifndef DL_ARGV_NOT_RELRO
663 attribute_relro
664# endif
665 ;
666#endif
667#define rtld_progname _dl_argv[0]
668
669/* Flag set at startup and cleared when the last initializer has run. */
670extern int _dl_starting_up;
671weak_extern (_dl_starting_up)
672rtld_hidden_proto (_dl_starting_up)
673
674/* Random data provided by the kernel. */
675extern void *_dl_random attribute_hidden attribute_relro;
676
677/* OS-dependent function to open the zero-fill device. */
678extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
679
680
681/* Write message on the debug file descriptor. The parameters are
682 interpreted as for a `printf' call. All the lines start with a
683 tag showing the PID. */
684extern void _dl_debug_printf (const char *fmt, ...)
685 __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
686
687/* Write message on the debug file descriptor. The parameters are
688 interpreted as for a `printf' call. All the lines buf the first
689 start with a tag showing the PID. */
690extern void _dl_debug_printf_c (const char *fmt, ...)
691 __attribute__ ((__format__ (__printf__, 1, 2)));
692
693
694/* Write a message on the specified descriptor FD. The parameters are
695 interpreted as for a `printf' call. */
696extern void _dl_dprintf (int fd, const char *fmt, ...)
697 __attribute__ ((__format__ (__printf__, 2, 3)))
698 attribute_hidden;
699
700/* Write a message on the specified descriptor standard output. The
701 parameters are interpreted as for a `printf' call. */
702#define _dl_printf(fmt, args...) \
703 _dl_dprintf (STDOUT_FILENO, fmt, ##args)
704
705/* Write a message on the specified descriptor standard error. The
706 parameters are interpreted as for a `printf' call. */
707#define _dl_error_printf(fmt, args...) \
708 _dl_dprintf (STDERR_FILENO, fmt, ##args)
709
710/* Write a message on the specified descriptor standard error and exit
711 the program. The parameters are interpreted as for a `printf' call. */
712#define _dl_fatal_printf(fmt, args...) \
713 do \
714 { \
715 _dl_dprintf (STDERR_FILENO, fmt, ##args); \
716 _exit (127); \
717 } \
718 while (1)
719
720
721/* This function is called by all the internal dynamic linker functions
722 when they encounter an error. ERRCODE is either an `errno' code or
723 zero; OBJECT is the name of the problematical shared object, or null if
724 it is a general problem; ERRSTRING is a string describing the specific
725 problem. */
726extern void _dl_signal_error (int errcode, const char *object,
727 const char *occurred, const char *errstring)
728 internal_function __attribute__ ((__noreturn__)) attribute_hidden;
729
730/* Like _dl_signal_error, but may return when called in the context of
731 _dl_receive_error. */
732extern void _dl_signal_cerror (int errcode, const char *object,
733 const char *occation, const char *errstring)
734 internal_function;
735
736/* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
737 `_dl_catch_error' the operation is resumed after the OPERATE
738 function returns.
739 ARGS is passed as argument to OPERATE. */
740extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
741 void *args)
742 internal_function;
743
744
745/* Open the shared object NAME and map in its segments.
746 LOADER's DT_RPATH is used in searching for NAME.
747 If the object is already opened, returns its existing map. */
748extern struct link_map *_dl_map_object (struct link_map *loader,
749 const char *name,
750 int type, int trace_mode, int mode,
751 Lmid_t nsid)
752 internal_function attribute_hidden;
753
754/* Call _dl_map_object on the dependencies of MAP, and set up
755 MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
756 loaded objects that will be inserted into MAP->l_searchlist after MAP
757 but before its dependencies. */
758extern void _dl_map_object_deps (struct link_map *map,
759 struct link_map **preloads,
760 unsigned int npreloads, int trace_mode,
761 int open_mode)
762 internal_function attribute_hidden;
763
764/* Cache the locations of MAP's hash table. */
765extern void _dl_setup_hash (struct link_map *map)
766 internal_function attribute_hidden;
767
768
769/* Collect the directories in the search path for LOADER's dependencies.
770 The data structure is defined in <dlfcn.h>. If COUNTING is true,
771 SI->dls_cnt and SI->dls_size are set; if false, those must be as set
772 by a previous call with COUNTING set, and SI must point to SI->dls_size
773 bytes to be used in filling in the result. */
774extern void _dl_rtld_di_serinfo (struct link_map *loader,
775 Dl_serinfo *si, bool counting)
776 internal_function;
777
778
779/* Search loaded objects' symbol tables for a definition of the symbol
780 referred to by UNDEF. *SYM is the symbol table entry containing the
781 reference; it is replaced with the defining symbol, and the base load
782 address of the defining object is returned. SYMBOL_SCOPE is a
783 null-terminated list of object scopes to search; each object's
784 l_searchlist (i.e. the segment of the dependency tree starting at that
785 object) is searched in turn. REFERENCE_NAME should name the object
786 containing the reference; it is used in error messages.
787 TYPE_CLASS describes the type of symbol we are looking for. */
788enum
789 {
790 /* If necessary add dependency between user and provider object. */
791 DL_LOOKUP_ADD_DEPENDENCY = 1,
792 /* Return most recent version instead of default version for
793 unversioned lookup. */
794 DL_LOOKUP_RETURN_NEWEST = 2,
795 /* Set if dl_lookup* called with GSCOPE lock held. */
796 DL_LOOKUP_GSCOPE_LOCK = 4,
797 };
798
799/* Lookup versioned symbol. */
800extern lookup_t _dl_lookup_symbol_x (const char *undef,
801 struct link_map *undef_map,
802 const ElfW(Sym) **sym,
803 struct r_scope_elem *symbol_scope[],
804 const struct r_found_version *version,
805 int type_class, int flags,
806 struct link_map *skip_map)
807 internal_function attribute_hidden;
808
809
810/* Look up symbol NAME in MAP's scope and return its run-time address. */
811extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name)
812 internal_function;
813
814/* Add the new link_map NEW to the end of the namespace list. */
815extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
816 internal_function attribute_hidden;
817
818/* Allocate a `struct link_map' for a new object being loaded. */
819extern struct link_map *_dl_new_object (char *realname, const char *libname,
820 int type, struct link_map *loader,
821 int mode, Lmid_t nsid)
822 internal_function attribute_hidden;
823
824/* Relocate the given object (if it hasn't already been).
825 SCOPE is passed to _dl_lookup_symbol in symbol lookups.
826 If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
827extern void _dl_relocate_object (struct link_map *map,
828 struct r_scope_elem *scope[],
829 int reloc_mode, int consider_profiling)
830 attribute_hidden;
831
832/* Protect PT_GNU_RELRO area. */
833extern void _dl_protect_relro (struct link_map *map)
834 internal_function attribute_hidden;
835
836/* Call _dl_signal_error with a message about an unhandled reloc type.
837 TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
838 PLT is nonzero if this was a PLT reloc; it just affects the message. */
839extern void _dl_reloc_bad_type (struct link_map *map,
840 unsigned int type, int plt)
841 internal_function __attribute__ ((__noreturn__));
842
843/* Resolve conflicts if prelinking. */
844extern void _dl_resolve_conflicts (struct link_map *l,
845 ElfW(Rela) *conflict,
846 ElfW(Rela) *conflictend);
847
848/* Check the version dependencies of all objects available through
849 MAP. If VERBOSE print some more diagnostics. */
850extern int _dl_check_all_versions (struct link_map *map, int verbose,
851 int trace_mode)
852 internal_function;
853
854/* Check the version dependencies for MAP. If VERBOSE print some more
855 diagnostics. */
856extern int _dl_check_map_versions (struct link_map *map, int verbose,
857 int trace_mode)
858 internal_function;
859
860/* Initialize the object in SCOPE by calling the constructors with
861 ARGC, ARGV, and ENV as the parameters. */
862extern void _dl_init (struct link_map *main_map, int argc, char **argv,
863 char **env) internal_function attribute_hidden;
864
865/* Call the finalizer functions of all shared objects whose
866 initializer functions have completed. */
867extern void _dl_fini (void) internal_function;
868
869/* Sort array MAPS according to dependencies of the contained objects. */
870extern void _dl_sort_fini (struct link_map **maps, size_t nmaps, char *used,
871 Lmid_t ns)
872 internal_function;
873
874/* The dynamic linker calls this function before and having changing
875 any shared object mappings. The `r_state' member of `struct r_debug'
876 says what change is taking place. This function's address is
877 the value of the `r_brk' member. */
878extern void _dl_debug_state (void);
879rtld_hidden_proto (_dl_debug_state)
880
881/* Initialize `struct r_debug' if it has not already been done. The
882 argument is the run-time load address of the dynamic linker, to be put
883 in the `r_ldbase' member. Returns the address of the structure. */
884extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
885 internal_function;
886
887/* Initialize the basic data structure for the search paths. */
888extern void _dl_init_paths (const char *library_path) internal_function;
889
890/* Gather the information needed to install the profiling tables and start
891 the timers. */
892extern void _dl_start_profile (void) internal_function attribute_hidden;
893
894/* The actual functions used to keep book on the calls. */
895extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
896rtld_hidden_proto (_dl_mcount)
897
898/* This function is simply a wrapper around the _dl_mcount function
899 which does not require a FROMPC parameter since this is the
900 calling function. */
901extern void _dl_mcount_wrapper (void *selfpc);
902
903/* Show the members of the auxiliary array passed up from the kernel. */
904extern void _dl_show_auxv (void) internal_function;
905
906/* Return all environment variables starting with `LD_', one after the
907 other. */
908extern char *_dl_next_ld_env_entry (char ***position) internal_function;
909
910/* Return an array with the names of the important hardware capabilities. */
911extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform,
912 size_t paltform_len,
913 size_t *sz,
914 size_t *max_capstrlen)
915 internal_function;
916
917/* Look up NAME in ld.so.cache and return the file name stored there,
918 or null if none is found. Caller must free returned string. */
919extern char *_dl_load_cache_lookup (const char *name)
920 internal_function;
921
922/* If the system does not support MAP_COPY we cannot leave the file open
923 all the time since this would create problems when the file is replaced.
924 Therefore we provide this function to close the file and open it again
925 once needed. */
926extern void _dl_unload_cache (void) attribute_hidden;
927
928/* System-dependent function to read a file's whole contents in the
929 most convenient manner available. *SIZEP gets the size of the
930 file. On error MAP_FAILED is returned. */
931extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
932 int prot)
933 internal_function attribute_hidden;
934
935/* System-specific function to do initial startup for the dynamic linker.
936 After this, file access calls and getenv must work. This is responsible
937 for setting __libc_enable_secure if we need to be secure (e.g. setuid),
938 and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
939extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
940 void (*dl_main) (const ElfW(Phdr) *phdr,
941 ElfW(Word) phnum,
942 ElfW(Addr) *user_entry,
943 ElfW(auxv_t) *auxv))
944 attribute_hidden;
945
946extern void _dl_sysdep_start_cleanup (void)
947 internal_function attribute_hidden;
948
949
950/* Determine next available module ID. */
951extern size_t _dl_next_tls_modid (void) internal_function attribute_hidden;
952
953/* Count the modules with TLS segments. */
954extern size_t _dl_count_modids (void) internal_function attribute_hidden;
955
956/* Calculate offset of the TLS blocks in the static TLS block. */
957extern void _dl_determine_tlsoffset (void) internal_function attribute_hidden;
958
959/* Set up the data structures for TLS, when they were not set up at startup.
960 Returns nonzero on malloc failure.
961 This is called from _dl_map_object_from_fd or by libpthread. */
962extern int _dl_tls_setup (void) internal_function;
963rtld_hidden_proto (_dl_tls_setup)
964
965/* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
966extern void *_dl_allocate_tls (void *mem) internal_function;
967rtld_hidden_proto (_dl_allocate_tls)
968
969/* Get size and alignment requirements of the static TLS block. */
970extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp)
971 internal_function;
972
973extern void _dl_allocate_static_tls (struct link_map *map)
974 internal_function attribute_hidden;
975
976/* These are internal entry points to the two halves of _dl_allocate_tls,
977 only used within rtld.c itself at startup time. */
978extern void *_dl_allocate_tls_storage (void)
979 internal_function attribute_hidden;
980extern void *_dl_allocate_tls_init (void *) internal_function;
981rtld_hidden_proto (_dl_allocate_tls_init)
982
983/* Deallocate memory allocated with _dl_allocate_tls. */
984extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb) internal_function;
985rtld_hidden_proto (_dl_deallocate_tls)
986
987extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
988
989/* Find origin of the executable. */
990extern const char *_dl_get_origin (void) attribute_hidden;
991
992/* Count DSTs. */
993extern size_t _dl_dst_count (const char *name, int is_path) attribute_hidden;
994
995/* Substitute DST values. */
996extern char *_dl_dst_substitute (struct link_map *l, const char *name,
997 char *result, int is_path) attribute_hidden;
998
999/* Check validity of the caller. */
1000extern int _dl_check_caller (const void *caller, enum allowmask mask)
1001 attribute_hidden;
1002
1003/* Open the shared object NAME, relocate it, and run its initializer if it
1004 hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
1005 the object is already opened, returns its existing map. */
1006extern void *_dl_open (const char *name, int mode, const void *caller,
1007 Lmid_t nsid, int argc, char *argv[], char *env[])
1008 attribute_hidden;
1009
1010/* Free or queue for freeing scope OLD. If other threads might be
1011 in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
1012 old scope, OLD can't be freed until no thread is using it. */
1013extern int _dl_scope_free (void *) attribute_hidden;
1014
1015/* Add module to slot information data. */
1016extern void _dl_add_to_slotinfo (struct link_map *l) attribute_hidden;
1017
1018/* Update slot information data for at least the generation of the
1019 module with the given index. */
1020extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid);
1021
1022/* Look up the module's TLS block as for __tls_get_addr,
1023 but never touch anything. Return null if it's not allocated yet. */
1024extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
1025
1026extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
1027 internal_function attribute_hidden;
1028
1029/* Show show of an object. */
1030extern void _dl_show_scope (struct link_map *new, int from);
1031
1032extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr)
1033 internal_function;
1034rtld_hidden_proto (_dl_find_dso_for_object)
1035
1036/* Initialization which is normally done by the dynamic linker. */
1037extern void _dl_non_dynamic_init (void) internal_function;
1038
1039/* Used by static binaries to check the auxiliary vector. */
1040extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function;
1041
1042
1043__END_DECLS
1044
1045#endif /* ldsodefs.h */