S390: Optimize wmemset.
[glibc.git] / sysdeps / i386 / dl-machine.h
blob4a28eb3765d42f7bcfc2732ddeb18c38093e55bf
1 /* Machine-dependent ELF dynamic relocation inline functions. i386 version.
2 Copyright (C) 1995-2015 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/>. */
19 #ifndef dl_machine_h
20 #define dl_machine_h
22 #define ELF_MACHINE_NAME "i386"
24 #include <sys/param.h>
25 #include <sysdep.h>
26 #include <tls.h>
27 #include <dl-tlsdesc.h>
28 #include <cpu-features.c>
30 /* Return nonzero iff ELF header is compatible with the running host. */
31 static inline int __attribute__ ((unused))
32 elf_machine_matches_host (const Elf32_Ehdr *ehdr)
34 return ehdr->e_machine == EM_386;
38 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
39 first element of the GOT, a special entry that is never relocated. */
40 static inline Elf32_Addr __attribute__ ((unused, const))
41 elf_machine_dynamic (void)
43 /* This produces a GOTOFF reloc that resolves to zero at link time, so in
44 fact just loads from the GOT register directly. By doing it without
45 an asm we can let the compiler choose any register. */
46 extern const Elf32_Addr _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
47 return _GLOBAL_OFFSET_TABLE_[0];
50 /* Return the run-time load address of the shared object. */
51 static inline Elf32_Addr __attribute__ ((unused))
52 elf_machine_load_address (void)
54 /* Compute the difference between the runtime address of _DYNAMIC as seen
55 by a GOTOFF reference, and the link-time address found in the special
56 unrelocated first GOT entry. */
57 extern Elf32_Dyn bygotoff[] asm ("_DYNAMIC") attribute_hidden;
58 return (Elf32_Addr) &bygotoff - elf_machine_dynamic ();
61 /* Set up the loaded object described by L so its unrelocated PLT
62 entries will jump to the on-demand fixup code in dl-runtime.c. */
64 static inline int __attribute__ ((unused, always_inline))
65 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
67 Elf32_Addr *got;
68 extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden;
69 extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
71 if (l->l_info[DT_JMPREL] && lazy)
73 /* The GOT entries for functions in the PLT have not yet been filled
74 in. Their initial contents will arrange when called to push an
75 offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
76 and then jump to _GLOBAL_OFFSET_TABLE[2]. */
77 got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
78 /* If a library is prelinked but we have to relocate anyway,
79 we have to be able to undo the prelinking of .got.plt.
80 The prelinker saved us here address of .plt + 0x16. */
81 if (got[1])
83 l->l_mach.plt = got[1] + l->l_addr;
84 l->l_mach.gotplt = (Elf32_Addr) &got[3];
86 got[1] = (Elf32_Addr) l; /* Identify this shared object. */
88 /* The got[2] entry contains the address of a function which gets
89 called to get the address of a so far unresolved function and
90 jump to it. The profiling extension of the dynamic linker allows
91 to intercept the calls to collect information. In this case we
92 don't store the address in the GOT so that all future calls also
93 end in this function. */
94 if (__glibc_unlikely (profile))
96 got[2] = (Elf32_Addr) &_dl_runtime_profile;
98 if (GLRO(dl_profile) != NULL
99 && _dl_name_match_p (GLRO(dl_profile), l))
100 /* This is the object we are looking for. Say that we really
101 want profiling and the timers are started. */
102 GL(dl_profile_map) = l;
104 else
105 /* This function will get called to fix up the GOT entry indicated by
106 the offset on the stack, and then jump to the resolved address. */
107 got[2] = (Elf32_Addr) &_dl_runtime_resolve;
110 return lazy;
113 #ifdef IN_DL_RUNTIME
115 # ifndef PROF
116 /* We add a declaration of this function here so that in dl-runtime.c
117 the ELF_MACHINE_RUNTIME_TRAMPOLINE macro really can pass the parameters
118 in registers.
120 We cannot use this scheme for profiling because the _mcount call
121 destroys the passed register information. */
122 #define ARCH_FIXUP_ATTRIBUTE __attribute__ ((regparm (3), stdcall, unused))
124 extern ElfW(Addr) _dl_fixup (struct link_map *l,
125 ElfW(Word) reloc_offset)
126 ARCH_FIXUP_ATTRIBUTE;
127 extern ElfW(Addr) _dl_profile_fixup (struct link_map *l,
128 ElfW(Word) reloc_offset,
129 ElfW(Addr) retaddr, void *regs,
130 long int *framesizep)
131 ARCH_FIXUP_ATTRIBUTE;
132 # endif
134 #endif
136 /* Mask identifying addresses reserved for the user program,
137 where the dynamic linker should not map anything. */
138 #define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
140 /* Initial entry point code for the dynamic linker.
141 The C function `_dl_start' is the real entry point;
142 its return value is the user program's entry point. */
144 #define RTLD_START asm ("\n\
145 .text\n\
146 .align 16\n\
147 0: movl (%esp), %ebx\n\
148 ret\n\
149 .align 16\n\
150 .globl _start\n\
151 .globl _dl_start_user\n\
152 _start:\n\
153 # Note that _dl_start gets the parameter in %eax.\n\
154 movl %esp, %eax\n\
155 call _dl_start\n\
156 _dl_start_user:\n\
157 # Save the user entry point address in %edi.\n\
158 movl %eax, %edi\n\
159 # Point %ebx at the GOT.\n\
160 call 0b\n\
161 addl $_GLOBAL_OFFSET_TABLE_, %ebx\n\
162 # See if we were run as a command with the executable file\n\
163 # name as an extra leading argument.\n\
164 movl _dl_skip_args@GOTOFF(%ebx), %eax\n\
165 # Pop the original argument count.\n\
166 popl %edx\n\
167 # Adjust the stack pointer to skip _dl_skip_args words.\n\
168 leal (%esp,%eax,4), %esp\n\
169 # Subtract _dl_skip_args from argc.\n\
170 subl %eax, %edx\n\
171 # Push argc back on the stack.\n\
172 push %edx\n\
173 # The special initializer gets called with the stack just\n\
174 # as the application's entry point will see it; it can\n\
175 # switch stacks if it moves these contents over.\n\
176 " RTLD_START_SPECIAL_INIT "\n\
177 # Load the parameters again.\n\
178 # (eax, edx, ecx, *--esp) = (_dl_loaded, argc, argv, envp)\n\
179 movl _rtld_local@GOTOFF(%ebx), %eax\n\
180 leal 8(%esp,%edx,4), %esi\n\
181 leal 4(%esp), %ecx\n\
182 movl %esp, %ebp\n\
183 # Make sure _dl_init is run with 16 byte aligned stack.\n\
184 andl $-16, %esp\n\
185 pushl %eax\n\
186 pushl %eax\n\
187 pushl %ebp\n\
188 pushl %esi\n\
189 # Clear %ebp, so that even constructors have terminated backchain.\n\
190 xorl %ebp, %ebp\n\
191 # Call the function to run the initializers.\n\
192 call _dl_init\n\
193 # Pass our finalizer function to the user in %edx, as per ELF ABI.\n\
194 leal _dl_fini@GOTOFF(%ebx), %edx\n\
195 # Restore %esp _start expects.\n\
196 movl (%esp), %esp\n\
197 # Jump to the user's entry point.\n\
198 jmp *%edi\n\
199 .previous\n\
202 #ifndef RTLD_START_SPECIAL_INIT
203 # define RTLD_START_SPECIAL_INIT /* nothing */
204 #endif
206 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
207 TLS variable, so undefined references should not be allowed to
208 define the value.
209 ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
210 of the main executable's symbols, as for a COPY reloc.
211 ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA iff TYPE describes relocation may
212 against protected data whose address be external due to copy relocation.
214 # define elf_machine_type_class(type) \
215 ((((type) == R_386_JMP_SLOT || (type) == R_386_TLS_DTPMOD32 \
216 || (type) == R_386_TLS_DTPOFF32 || (type) == R_386_TLS_TPOFF32 \
217 || (type) == R_386_TLS_TPOFF || (type) == R_386_TLS_DESC) \
218 * ELF_RTYPE_CLASS_PLT) \
219 | (((type) == R_386_COPY) * ELF_RTYPE_CLASS_COPY) \
220 | (((type) == R_386_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
222 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
223 #define ELF_MACHINE_JMP_SLOT R_386_JMP_SLOT
225 /* The i386 never uses Elf32_Rela relocations for the dynamic linker.
226 Prelinked libraries may use Elf32_Rela though. */
227 #define ELF_MACHINE_PLT_REL 1
229 /* We define an initialization functions. This is called very early in
230 _dl_sysdep_start. */
231 #define DL_PLATFORM_INIT dl_platform_init ()
233 static inline void __attribute__ ((unused))
234 dl_platform_init (void)
236 if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
237 /* Avoid an empty string which would disturb us. */
238 GLRO(dl_platform) = NULL;
240 init_cpu_features (&GLRO(dl_x86_cpu_features));
243 static inline Elf32_Addr
244 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
245 const Elf32_Rel *reloc,
246 Elf32_Addr *reloc_addr, Elf32_Addr value)
248 return *reloc_addr = value;
251 /* Return the final value of a plt relocation. */
252 static inline Elf32_Addr
253 elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc,
254 Elf32_Addr value)
256 return value;
260 /* Names of the architecture-specific auditing callback functions. */
261 #define ARCH_LA_PLTENTER i86_gnu_pltenter
262 #define ARCH_LA_PLTEXIT i86_gnu_pltexit
264 #endif /* !dl_machine_h */
266 /* The i386 never uses Elf32_Rela relocations for the dynamic linker.
267 Prelinked libraries may use Elf32_Rela though. */
268 #define ELF_MACHINE_NO_RELA defined RTLD_BOOTSTRAP
269 #define ELF_MACHINE_NO_REL 0
271 #ifdef RESOLVE_MAP
273 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
274 MAP is the object containing the reloc. */
276 auto inline void
277 __attribute ((always_inline))
278 elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
279 const Elf32_Sym *sym, const struct r_found_version *version,
280 void *const reloc_addr_arg, int skip_ifunc)
282 Elf32_Addr *const reloc_addr = reloc_addr_arg;
283 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
285 # if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
286 if (__glibc_unlikely (r_type == R_386_RELATIVE))
288 # if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
289 /* This is defined in rtld.c, but nowhere in the static libc.a;
290 make the reference weak so static programs can still link.
291 This declaration cannot be done when compiling rtld.c
292 (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the
293 common defn for _dl_rtld_map, which is incompatible with a
294 weak decl in the same file. */
295 # ifndef SHARED
296 weak_extern (_dl_rtld_map);
297 # endif
298 if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */
299 # endif
300 *reloc_addr += map->l_addr;
302 # ifndef RTLD_BOOTSTRAP
303 else if (__glibc_unlikely (r_type == R_386_NONE))
304 return;
305 # endif
306 else
307 # endif /* !RTLD_BOOTSTRAP and have no -z combreloc */
309 # ifndef RTLD_BOOTSTRAP
310 const Elf32_Sym *const refsym = sym;
311 # endif
312 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
313 Elf32_Addr value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
315 if (sym != NULL
316 && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
318 && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
319 && __builtin_expect (!skip_ifunc, 1))
320 value = ((Elf32_Addr (*) (void)) value) ();
322 switch (r_type)
324 # ifndef RTLD_BOOTSTRAP
325 case R_386_SIZE32:
326 /* Set to symbol size plus addend. */
327 *reloc_addr += sym->st_size;
328 break;
329 # endif
330 case R_386_GLOB_DAT:
331 case R_386_JMP_SLOT:
332 *reloc_addr = value;
333 break;
335 case R_386_TLS_DTPMOD32:
336 # ifdef RTLD_BOOTSTRAP
337 /* During startup the dynamic linker is always the module
338 with index 1.
339 XXX If this relocation is necessary move before RESOLVE
340 call. */
341 *reloc_addr = 1;
342 # else
343 /* Get the information from the link map returned by the
344 resolv function. */
345 if (sym_map != NULL)
346 *reloc_addr = sym_map->l_tls_modid;
347 # endif
348 break;
349 case R_386_TLS_DTPOFF32:
350 # ifndef RTLD_BOOTSTRAP
351 /* During relocation all TLS symbols are defined and used.
352 Therefore the offset is already correct. */
353 if (sym != NULL)
354 *reloc_addr = sym->st_value;
355 # endif
356 break;
357 case R_386_TLS_DESC:
359 struct tlsdesc volatile *td =
360 (struct tlsdesc volatile *)reloc_addr;
362 # ifndef RTLD_BOOTSTRAP
363 if (! sym)
364 td->entry = _dl_tlsdesc_undefweak;
365 else
366 # endif
368 # ifndef RTLD_BOOTSTRAP
369 # ifndef SHARED
370 CHECK_STATIC_TLS (map, sym_map);
371 # else
372 if (!TRY_STATIC_TLS (map, sym_map))
374 td->arg = _dl_make_tlsdesc_dynamic
375 (sym_map, sym->st_value + (ElfW(Word))td->arg);
376 td->entry = _dl_tlsdesc_dynamic;
378 else
379 # endif
380 # endif
382 td->arg = (void*)(sym->st_value - sym_map->l_tls_offset
383 + (ElfW(Word))td->arg);
384 td->entry = _dl_tlsdesc_return;
387 break;
389 case R_386_TLS_TPOFF32:
390 /* The offset is positive, backward from the thread pointer. */
391 # ifdef RTLD_BOOTSTRAP
392 *reloc_addr += map->l_tls_offset - sym->st_value;
393 # else
394 /* We know the offset of object the symbol is contained in.
395 It is a positive value which will be subtracted from the
396 thread pointer. To get the variable position in the TLS
397 block we subtract the offset from that of the TLS block. */
398 if (sym != NULL)
400 CHECK_STATIC_TLS (map, sym_map);
401 *reloc_addr += sym_map->l_tls_offset - sym->st_value;
403 # endif
404 break;
405 case R_386_TLS_TPOFF:
406 /* The offset is negative, forward from the thread pointer. */
407 # ifdef RTLD_BOOTSTRAP
408 *reloc_addr += sym->st_value - map->l_tls_offset;
409 # else
410 /* We know the offset of object the symbol is contained in.
411 It is a negative value which will be added to the
412 thread pointer. */
413 if (sym != NULL)
415 CHECK_STATIC_TLS (map, sym_map);
416 *reloc_addr += sym->st_value - sym_map->l_tls_offset;
418 # endif
419 break;
421 # ifndef RTLD_BOOTSTRAP
422 case R_386_32:
423 *reloc_addr += value;
424 break;
425 case R_386_PC32:
426 *reloc_addr += (value - (Elf32_Addr) reloc_addr);
427 break;
428 case R_386_COPY:
429 if (sym == NULL)
430 /* This can happen in trace mode if an object could not be
431 found. */
432 break;
433 if (__builtin_expect (sym->st_size > refsym->st_size, 0)
434 || (__builtin_expect (sym->st_size < refsym->st_size, 0)
435 && GLRO(dl_verbose)))
437 const char *strtab;
439 strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
440 _dl_error_printf ("\
441 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
442 RTLD_PROGNAME, strtab + refsym->st_name);
444 memcpy (reloc_addr_arg, (void *) value,
445 MIN (sym->st_size, refsym->st_size));
446 break;
447 case R_386_IRELATIVE:
448 value = map->l_addr + *reloc_addr;
449 value = ((Elf32_Addr (*) (void)) value) ();
450 *reloc_addr = value;
451 break;
452 default:
453 _dl_reloc_bad_type (map, r_type, 0);
454 break;
455 # endif /* !RTLD_BOOTSTRAP */
460 # ifndef RTLD_BOOTSTRAP
461 auto inline void
462 __attribute__ ((always_inline))
463 elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
464 const Elf32_Sym *sym, const struct r_found_version *version,
465 void *const reloc_addr_arg, int skip_ifunc)
467 Elf32_Addr *const reloc_addr = reloc_addr_arg;
468 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
470 if (ELF32_R_TYPE (reloc->r_info) == R_386_RELATIVE)
471 *reloc_addr = map->l_addr + reloc->r_addend;
472 else if (r_type != R_386_NONE)
474 # ifndef RESOLVE_CONFLICT_FIND_MAP
475 const Elf32_Sym *const refsym = sym;
476 # endif
477 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
478 Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
480 if (sym != NULL
481 && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
482 && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
483 && __builtin_expect (!skip_ifunc, 1))
484 value = ((Elf32_Addr (*) (void)) value) ();
486 switch (ELF32_R_TYPE (reloc->r_info))
488 case R_386_SIZE32:
489 /* Set to symbol size plus addend. */
490 value = sym->st_size;
491 case R_386_GLOB_DAT:
492 case R_386_JMP_SLOT:
493 case R_386_32:
494 *reloc_addr = value + reloc->r_addend;
495 break;
496 # ifndef RESOLVE_CONFLICT_FIND_MAP
497 /* Not needed for dl-conflict.c. */
498 case R_386_PC32:
499 *reloc_addr = (value + reloc->r_addend - (Elf32_Addr) reloc_addr);
500 break;
502 case R_386_TLS_DTPMOD32:
503 /* Get the information from the link map returned by the
504 resolv function. */
505 if (sym_map != NULL)
506 *reloc_addr = sym_map->l_tls_modid;
507 break;
508 case R_386_TLS_DTPOFF32:
509 /* During relocation all TLS symbols are defined and used.
510 Therefore the offset is already correct. */
511 *reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
512 break;
513 case R_386_TLS_DESC:
515 struct tlsdesc volatile *td =
516 (struct tlsdesc volatile *)reloc_addr;
518 # ifndef RTLD_BOOTSTRAP
519 if (!sym)
521 td->arg = (void*)reloc->r_addend;
522 td->entry = _dl_tlsdesc_undefweak;
524 else
525 # endif
527 # ifndef RTLD_BOOTSTRAP
528 # ifndef SHARED
529 CHECK_STATIC_TLS (map, sym_map);
530 # else
531 if (!TRY_STATIC_TLS (map, sym_map))
533 td->arg = _dl_make_tlsdesc_dynamic
534 (sym_map, sym->st_value + reloc->r_addend);
535 td->entry = _dl_tlsdesc_dynamic;
537 else
538 # endif
539 # endif
541 td->arg = (void*)(sym->st_value - sym_map->l_tls_offset
542 + reloc->r_addend);
543 td->entry = _dl_tlsdesc_return;
547 break;
548 case R_386_TLS_TPOFF32:
549 /* The offset is positive, backward from the thread pointer. */
550 /* We know the offset of object the symbol is contained in.
551 It is a positive value which will be subtracted from the
552 thread pointer. To get the variable position in the TLS
553 block we subtract the offset from that of the TLS block. */
554 if (sym != NULL)
556 CHECK_STATIC_TLS (map, sym_map);
557 *reloc_addr = sym_map->l_tls_offset - sym->st_value
558 + reloc->r_addend;
560 break;
561 case R_386_TLS_TPOFF:
562 /* The offset is negative, forward from the thread pointer. */
563 /* We know the offset of object the symbol is contained in.
564 It is a negative value which will be added to the
565 thread pointer. */
566 if (sym != NULL)
568 CHECK_STATIC_TLS (map, sym_map);
569 *reloc_addr = sym->st_value - sym_map->l_tls_offset
570 + reloc->r_addend;
572 break;
573 case R_386_COPY:
574 if (sym == NULL)
575 /* This can happen in trace mode if an object could not be
576 found. */
577 break;
578 if (__builtin_expect (sym->st_size > refsym->st_size, 0)
579 || (__builtin_expect (sym->st_size < refsym->st_size, 0)
580 && GLRO(dl_verbose)))
582 const char *strtab;
584 strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
585 _dl_error_printf ("\
586 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
587 RTLD_PROGNAME, strtab + refsym->st_name);
589 memcpy (reloc_addr_arg, (void *) value,
590 MIN (sym->st_size, refsym->st_size));
591 break;
592 # endif /* !RESOLVE_CONFLICT_FIND_MAP */
593 case R_386_IRELATIVE:
594 value = map->l_addr + reloc->r_addend;
595 value = ((Elf32_Addr (*) (void)) value) ();
596 *reloc_addr = value;
597 break;
598 default:
599 /* We add these checks in the version to relocate ld.so only
600 if we are still debugging. */
601 _dl_reloc_bad_type (map, r_type, 0);
602 break;
606 # endif /* !RTLD_BOOTSTRAP */
608 auto inline void
609 __attribute ((always_inline))
610 elf_machine_rel_relative (Elf32_Addr l_addr, const Elf32_Rel *reloc,
611 void *const reloc_addr_arg)
613 Elf32_Addr *const reloc_addr = reloc_addr_arg;
614 assert (ELF32_R_TYPE (reloc->r_info) == R_386_RELATIVE);
615 *reloc_addr += l_addr;
618 # ifndef RTLD_BOOTSTRAP
619 auto inline void
620 __attribute__ ((always_inline))
621 elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
622 void *const reloc_addr_arg)
624 Elf32_Addr *const reloc_addr = reloc_addr_arg;
625 *reloc_addr = l_addr + reloc->r_addend;
627 # endif /* !RTLD_BOOTSTRAP */
629 auto inline void
630 __attribute__ ((always_inline))
631 elf_machine_lazy_rel (struct link_map *map,
632 Elf32_Addr l_addr, const Elf32_Rel *reloc,
633 int skip_ifunc)
635 Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
636 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
637 /* Check for unexpected PLT reloc type. */
638 if (__glibc_likely (r_type == R_386_JMP_SLOT))
640 if (__builtin_expect (map->l_mach.plt, 0) == 0)
641 *reloc_addr += l_addr;
642 else
643 *reloc_addr = (map->l_mach.plt
644 + (((Elf32_Addr) reloc_addr) - map->l_mach.gotplt) * 4);
646 else if (__glibc_likely (r_type == R_386_TLS_DESC))
648 struct tlsdesc volatile * __attribute__((__unused__)) td =
649 (struct tlsdesc volatile *)reloc_addr;
651 /* Handle relocations that reference the local *ABS* in a simple
652 way, so as to preserve a potential addend. */
653 if (ELF32_R_SYM (reloc->r_info) == 0)
654 td->entry = _dl_tlsdesc_resolve_abs_plus_addend;
655 /* Given a known-zero addend, we can store a pointer to the
656 reloc in the arg position. */
657 else if (td->arg == 0)
659 td->arg = (void*)reloc;
660 td->entry = _dl_tlsdesc_resolve_rel;
662 else
664 /* We could handle non-*ABS* relocations with non-zero addends
665 by allocating dynamically an arg to hold a pointer to the
666 reloc, but that sounds pointless. */
667 const Elf32_Rel *const r = reloc;
668 /* The code below was borrowed from elf_dynamic_do_rel(). */
669 const ElfW(Sym) *const symtab =
670 (const void *) D_PTR (map, l_info[DT_SYMTAB]);
672 # ifdef RTLD_BOOTSTRAP
673 /* The dynamic linker always uses versioning. */
674 assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL);
675 # else
676 if (map->l_info[VERSYMIDX (DT_VERSYM)])
677 # endif
679 const ElfW(Half) *const version =
680 (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
681 ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
682 elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
683 &map->l_versions[ndx],
684 (void *) (l_addr + r->r_offset), skip_ifunc);
686 # ifndef RTLD_BOOTSTRAP
687 else
688 elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
689 (void *) (l_addr + r->r_offset), skip_ifunc);
690 # endif
693 else if (__glibc_unlikely (r_type == R_386_IRELATIVE))
695 Elf32_Addr value = map->l_addr + *reloc_addr;
696 if (__glibc_likely (!skip_ifunc))
697 value = ((Elf32_Addr (*) (void)) value) ();
698 *reloc_addr = value;
700 else
701 _dl_reloc_bad_type (map, r_type, 1);
704 # ifndef RTLD_BOOTSTRAP
706 auto inline void
707 __attribute__ ((always_inline))
708 elf_machine_lazy_rela (struct link_map *map,
709 Elf32_Addr l_addr, const Elf32_Rela *reloc,
710 int skip_ifunc)
712 Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
713 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
714 if (__glibc_likely (r_type == R_386_JMP_SLOT))
716 else if (__glibc_likely (r_type == R_386_TLS_DESC))
718 struct tlsdesc volatile * __attribute__((__unused__)) td =
719 (struct tlsdesc volatile *)reloc_addr;
721 td->arg = (void*)reloc;
722 td->entry = _dl_tlsdesc_resolve_rela;
724 else if (__glibc_unlikely (r_type == R_386_IRELATIVE))
726 Elf32_Addr value = map->l_addr + reloc->r_addend;
727 if (__glibc_likely (!skip_ifunc))
728 value = ((Elf32_Addr (*) (void)) value) ();
729 *reloc_addr = value;
731 else
732 _dl_reloc_bad_type (map, r_type, 1);
735 # endif /* !RTLD_BOOTSTRAP */
737 #endif /* RESOLVE_MAP */