1 /* Machine-dependent ELF dynamic relocation inline functions.  x86-64 version.
2    Copyright (C) 2001-2021 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    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef dl_machine_h
20 #define dl_machine_h
21 
22 #define ELF_MACHINE_NAME "x86_64"
23 
24 #include <assert.h>
25 #include <sys/param.h>
26 #include <sysdep.h>
27 #include <tls.h>
28 #include <dl-tlsdesc.h>
29 #include <dl-static-tls.h>
30 #include <dl-machine-rel.h>
31 
32 /* Return nonzero iff ELF header is compatible with the running host.  */
33 static inline int __attribute__ ((unused))
elf_machine_matches_host(const ElfW (Ehdr)* ehdr)34 elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
35 {
36   return ehdr->e_machine == EM_X86_64;
37 }
38 
39 
40 /* Return the run-time load address of the shared object.  */
41 static inline ElfW(Addr) __attribute__ ((unused))
elf_machine_load_address(void)42 elf_machine_load_address (void)
43 {
44   extern const ElfW(Ehdr) __ehdr_start attribute_hidden;
45   return (ElfW(Addr)) &__ehdr_start;
46 }
47 
48 /* Return the link-time address of _DYNAMIC.  */
49 static inline ElfW(Addr) __attribute__ ((unused))
elf_machine_dynamic(void)50 elf_machine_dynamic (void)
51 {
52   extern ElfW(Dyn) _DYNAMIC[] attribute_hidden;
53   return (ElfW(Addr)) _DYNAMIC - elf_machine_load_address ();
54 }
55 
56 /* Set up the loaded object described by L so its unrelocated PLT
57    entries will jump to the on-demand fixup code in dl-runtime.c.  */
58 
59 static inline int __attribute__ ((unused, always_inline))
elf_machine_runtime_setup(struct link_map * l,struct r_scope_elem * scope[],int lazy,int profile)60 elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
61 			   int lazy, int profile)
62 {
63   Elf64_Addr *got;
64   extern void _dl_runtime_resolve_fxsave (ElfW(Word)) attribute_hidden;
65   extern void _dl_runtime_resolve_xsave (ElfW(Word)) attribute_hidden;
66   extern void _dl_runtime_resolve_xsavec (ElfW(Word)) attribute_hidden;
67   extern void _dl_runtime_profile_sse (ElfW(Word)) attribute_hidden;
68   extern void _dl_runtime_profile_avx (ElfW(Word)) attribute_hidden;
69   extern void _dl_runtime_profile_avx512 (ElfW(Word)) attribute_hidden;
70 
71   if (l->l_info[DT_JMPREL] && lazy)
72     {
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 = (Elf64_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])
82 	{
83 	  l->l_mach.plt = got[1] + l->l_addr;
84 	  l->l_mach.gotplt = (ElfW(Addr)) &got[3];
85 	}
86       /* Identify this shared object.  */
87       *(ElfW(Addr) *) (got + 1) = (ElfW(Addr)) l;
88 
89       /* The got[2] entry contains the address of a function which gets
90 	 called to get the address of a so far unresolved function and
91 	 jump to it.  The profiling extension of the dynamic linker allows
92 	 to intercept the calls to collect information.  In this case we
93 	 don't store the address in the GOT so that all future calls also
94 	 end in this function.  */
95       if (__glibc_unlikely (profile))
96 	{
97 	  if (CPU_FEATURE_USABLE (AVX512F))
98 	    *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_avx512;
99 	  else if (CPU_FEATURE_USABLE (AVX))
100 	    *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_avx;
101 	  else
102 	    *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_sse;
103 
104 	  if (GLRO(dl_profile) != NULL
105 	      && _dl_name_match_p (GLRO(dl_profile), l))
106 	    /* This is the object we are looking for.  Say that we really
107 	       want profiling and the timers are started.  */
108 	    GL(dl_profile_map) = l;
109 	}
110       else
111 	{
112 	  /* This function will get called to fix up the GOT entry
113 	     indicated by the offset on the stack, and then jump to
114 	     the resolved address.  */
115 	  if (GLRO(dl_x86_cpu_features).xsave_state_size != 0)
116 	    *(ElfW(Addr) *) (got + 2)
117 	      = (CPU_FEATURE_USABLE (XSAVEC)
118 		 ? (ElfW(Addr)) &_dl_runtime_resolve_xsavec
119 		 : (ElfW(Addr)) &_dl_runtime_resolve_xsave);
120 	  else
121 	    *(ElfW(Addr) *) (got + 2)
122 	      = (ElfW(Addr)) &_dl_runtime_resolve_fxsave;
123 	}
124     }
125 
126   return lazy;
127 }
128 
129 /* Initial entry point code for the dynamic linker.
130    The C function `_dl_start' is the real entry point;
131    its return value is the user program's entry point.  */
132 #define RTLD_START asm ("\n\
133 .text\n\
134 	.align 16\n\
135 .globl _start\n\
136 .globl _dl_start_user\n\
137 _start:\n\
138 	movq %rsp, %rdi\n\
139 	call _dl_start\n\
140 _dl_start_user:\n\
141 	# Save the user entry point address in %r12.\n\
142 	movq %rax, %r12\n\
143 	# See if we were run as a command with the executable file\n\
144 	# name as an extra leading argument.\n\
145 	movl _dl_skip_args(%rip), %eax\n\
146 	# Pop the original argument count.\n\
147 	popq %rdx\n\
148 	# Adjust the stack pointer to skip _dl_skip_args words.\n\
149 	leaq (%rsp,%rax,8), %rsp\n\
150 	# Subtract _dl_skip_args from argc.\n\
151 	subl %eax, %edx\n\
152 	# Push argc back on the stack.\n\
153 	pushq %rdx\n\
154 	# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
155 	# argc -> rsi\n\
156 	movq %rdx, %rsi\n\
157 	# Save %rsp value in %r13.\n\
158 	movq %rsp, %r13\n\
159 	# And align stack for the _dl_init call. \n\
160 	andq $-16, %rsp\n\
161 	# _dl_loaded -> rdi\n\
162 	movq _rtld_local(%rip), %rdi\n\
163 	# env -> rcx\n\
164 	leaq 16(%r13,%rdx,8), %rcx\n\
165 	# argv -> rdx\n\
166 	leaq 8(%r13), %rdx\n\
167 	# Clear %rbp to mark outermost frame obviously even for constructors.\n\
168 	xorl %ebp, %ebp\n\
169 	# Call the function to run the initializers.\n\
170 	call _dl_init\n\
171 	# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
172 	leaq _dl_fini(%rip), %rdx\n\
173 	# And make sure %rsp points to argc stored on the stack.\n\
174 	movq %r13, %rsp\n\
175 	# Jump to the user's entry point.\n\
176 	jmp *%r12\n\
177 .previous\n\
178 ");
179 
180 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
181    TLS variable, so undefined references should not be allowed to
182    define the value.
183    ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
184    of the main executable's symbols, as for a COPY reloc.
185    ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA iff TYPE describes relocation may
186    against protected data whose address be external due to copy relocation.
187  */
188 #define elf_machine_type_class(type)					      \
189   ((((type) == R_X86_64_JUMP_SLOT					      \
190      || (type) == R_X86_64_DTPMOD64					      \
191      || (type) == R_X86_64_DTPOFF64					      \
192      || (type) == R_X86_64_TPOFF64					      \
193      || (type) == R_X86_64_TLSDESC)					      \
194     * ELF_RTYPE_CLASS_PLT)						      \
195    | (((type) == R_X86_64_COPY) * ELF_RTYPE_CLASS_COPY)			      \
196    | (((type) == R_X86_64_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
197 
198 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
199 #define ELF_MACHINE_JMP_SLOT	R_X86_64_JUMP_SLOT
200 
201 /* The relative ifunc relocation.  */
202 // XXX This is a work-around for a broken linker.  Remove!
203 #define ELF_MACHINE_IRELATIVE	R_X86_64_IRELATIVE
204 
205 /* We define an initialization function.  This is called very early in
206    _dl_sysdep_start.  */
207 #define DL_PLATFORM_INIT dl_platform_init ()
208 
209 static inline void __attribute__ ((unused))
dl_platform_init(void)210 dl_platform_init (void)
211 {
212 #if IS_IN (rtld)
213   /* _dl_x86_init_cpu_features is a wrapper for init_cpu_features which
214      has been called early from __libc_start_main in static executable.  */
215   _dl_x86_init_cpu_features ();
216 #else
217   if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
218     /* Avoid an empty string which would disturb us.  */
219     GLRO(dl_platform) = NULL;
220 #endif
221 }
222 
223 static inline ElfW(Addr)
elf_machine_fixup_plt(struct link_map * map,lookup_t t,const ElfW (Sym)* refsym,const ElfW (Sym)* sym,const ElfW (Rela)* reloc,ElfW (Addr)* reloc_addr,ElfW (Addr)value)224 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
225 		       const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
226 		       const ElfW(Rela) *reloc,
227 		       ElfW(Addr) *reloc_addr, ElfW(Addr) value)
228 {
229   return *reloc_addr = value;
230 }
231 
232 /* Return the final value of a PLT relocation.  On x86-64 the
233    JUMP_SLOT relocation ignores the addend.  */
234 static inline ElfW(Addr)
elf_machine_plt_value(struct link_map * map,const ElfW (Rela)* reloc,ElfW (Addr)value)235 elf_machine_plt_value (struct link_map *map, const ElfW(Rela) *reloc,
236 		       ElfW(Addr) value)
237 {
238   return value;
239 }
240 
241 
242 /* Names of the architecture-specific auditing callback functions.  */
243 #define ARCH_LA_PLTENTER x86_64_gnu_pltenter
244 #define ARCH_LA_PLTEXIT x86_64_gnu_pltexit
245 
246 #endif /* !dl_machine_h */
247 
248 #ifdef RESOLVE_MAP
249 
250 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
251    MAP is the object containing the reloc.  */
252 
253 static inline void __attribute__((always_inline))
elf_machine_rela(struct link_map * map,struct r_scope_elem * scope[],const ElfW (Rela)* reloc,const ElfW (Sym)* sym,const struct r_found_version * version,void * const reloc_addr_arg,int skip_ifunc)254 elf_machine_rela(struct link_map *map, struct r_scope_elem *scope[],
255 		 const ElfW(Rela) *reloc, const ElfW(Sym) *sym,
256 		 const struct r_found_version *version,
257 		 void *const reloc_addr_arg, int skip_ifunc) {
258   ElfW(Addr) *const reloc_addr = reloc_addr_arg;
259   const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
260 
261 # if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
262   if (__glibc_unlikely (r_type == R_X86_64_RELATIVE))
263     {
264 #  if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
265       /* This is defined in rtld.c, but nowhere in the static libc.a;
266 	 make the reference weak so static programs can still link.
267 	 This declaration cannot be done when compiling rtld.c
268 	 (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the
269 	 common defn for _dl_rtld_map, which is incompatible with a
270 	 weak decl in the same file.  */
271 #   ifndef SHARED
272       weak_extern (GL(dl_rtld_map));
273 #   endif
274       if (map != &GL(dl_rtld_map)) /* Already done in rtld itself.  */
275 #  endif
276 	*reloc_addr = map->l_addr + reloc->r_addend;
277     }
278   else
279 # endif
280 # if !defined RTLD_BOOTSTRAP
281   /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64
282      relocation updates the whole 64-bit entry.  */
283   if (__glibc_unlikely (r_type == R_X86_64_RELATIVE64))
284     *(Elf64_Addr *) reloc_addr = (Elf64_Addr) map->l_addr + reloc->r_addend;
285   else
286 # endif
287   if (__glibc_unlikely (r_type == R_X86_64_NONE))
288     return;
289   else
290     {
291 # ifndef RTLD_BOOTSTRAP
292       const ElfW(Sym) *const refsym = sym;
293 # endif
294       struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version,
295 					      r_type);
296       ElfW(Addr) value = SYMBOL_ADDRESS (sym_map, sym, true);
297 
298       if (sym != NULL
299 	  && __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
300 	  && __glibc_likely (sym->st_shndx != SHN_UNDEF)
301 	  && __glibc_likely (!skip_ifunc))
302 	{
303 # ifndef RTLD_BOOTSTRAP
304 	  if (sym_map != map
305 	      && !sym_map->l_relocated)
306 	    {
307 	      const char *strtab
308 		= (const char *) D_PTR (map, l_info[DT_STRTAB]);
309 	      if (sym_map->l_type == lt_executable)
310 		_dl_fatal_printf ("\
311 %s: IFUNC symbol '%s' referenced in '%s' is defined in the executable \
312 and creates an unsatisfiable circular dependency.\n",
313 				  RTLD_PROGNAME, strtab + refsym->st_name,
314 				  map->l_name);
315 	      else
316 		_dl_error_printf ("\
317 %s: Relink `%s' with `%s' for IFUNC symbol `%s'\n",
318 				  RTLD_PROGNAME, map->l_name,
319 				  sym_map->l_name,
320 				  strtab + refsym->st_name);
321 	    }
322 # endif
323 	  value = ((ElfW(Addr) (*) (void)) value) ();
324 	}
325 
326       switch (r_type)
327 	{
328 # ifndef RTLD_BOOTSTRAP
329 #  ifdef __ILP32__
330 	case R_X86_64_SIZE64:
331 	  /* Set to symbol size plus addend.  */
332 	  *(Elf64_Addr *) (uintptr_t) reloc_addr
333 	    = (Elf64_Addr) sym->st_size + reloc->r_addend;
334 	  break;
335 
336 	case R_X86_64_SIZE32:
337 #  else
338 	case R_X86_64_SIZE64:
339 #  endif
340 	  /* Set to symbol size plus addend.  */
341 	  value = sym->st_size;
342 # endif
343 	  /* Fall through.  */
344 	case R_X86_64_GLOB_DAT:
345 	case R_X86_64_JUMP_SLOT:
346 	  *reloc_addr = value + reloc->r_addend;
347 	  break;
348 
349 # ifndef RESOLVE_CONFLICT_FIND_MAP
350 	case R_X86_64_DTPMOD64:
351 #  ifdef RTLD_BOOTSTRAP
352 	  /* During startup the dynamic linker is always the module
353 	     with index 1.
354 	     XXX If this relocation is necessary move before RESOLVE
355 	     call.  */
356 	  *reloc_addr = 1;
357 #  else
358 	  /* Get the information from the link map returned by the
359 	     resolve function.  */
360 	  if (sym_map != NULL)
361 	    *reloc_addr = sym_map->l_tls_modid;
362 #  endif
363 	  break;
364 	case R_X86_64_DTPOFF64:
365 #  ifndef RTLD_BOOTSTRAP
366 	  /* During relocation all TLS symbols are defined and used.
367 	     Therefore the offset is already correct.  */
368 	  if (sym != NULL)
369 	    {
370 	      value = sym->st_value + reloc->r_addend;
371 #   ifdef __ILP32__
372 	      /* This relocation type computes a signed offset that is
373 		 usually negative.  The symbol and addend values are 32
374 		 bits but the GOT entry is 64 bits wide and the whole
375 		 64-bit entry is used as a signed quantity, so we need
376 		 to sign-extend the computed value to 64 bits.  */
377 	      *(Elf64_Sxword *) reloc_addr = (Elf64_Sxword) (Elf32_Sword) value;
378 #   else
379 	      *reloc_addr = value;
380 #   endif
381 	    }
382 #  endif
383 	  break;
384 	case R_X86_64_TLSDESC:
385 	  {
386 	    struct tlsdesc volatile *td =
387 	      (struct tlsdesc volatile *)reloc_addr;
388 
389 #  ifndef RTLD_BOOTSTRAP
390 	    if (! sym)
391 	      {
392 		td->arg = (void*)reloc->r_addend;
393 		td->entry = _dl_tlsdesc_undefweak;
394 	      }
395 	    else
396 #  endif
397 	      {
398 #  ifndef RTLD_BOOTSTRAP
399 #   ifndef SHARED
400 		CHECK_STATIC_TLS (map, sym_map);
401 #   else
402 		if (!TRY_STATIC_TLS (map, sym_map))
403 		  {
404 		    td->arg = _dl_make_tlsdesc_dynamic
405 		      (sym_map, sym->st_value + reloc->r_addend);
406 		    td->entry = _dl_tlsdesc_dynamic;
407 		  }
408 		else
409 #   endif
410 #  endif
411 		  {
412 		    td->arg = (void*)(sym->st_value - sym_map->l_tls_offset
413 				      + reloc->r_addend);
414 		    td->entry = _dl_tlsdesc_return;
415 		  }
416 	      }
417 	    break;
418 	  }
419 	case R_X86_64_TPOFF64:
420 	  /* The offset is negative, forward from the thread pointer.  */
421 #  ifndef RTLD_BOOTSTRAP
422 	  if (sym != NULL)
423 #  endif
424 	    {
425 #  ifndef RTLD_BOOTSTRAP
426 	      CHECK_STATIC_TLS (map, sym_map);
427 #  endif
428 	      /* We know the offset of the object the symbol is contained in.
429 		 It is a negative value which will be added to the
430 		 thread pointer.  */
431 	      value = (sym->st_value + reloc->r_addend
432 		       - sym_map->l_tls_offset);
433 #  ifdef __ILP32__
434 	      /* The symbol and addend values are 32 bits but the GOT
435 		 entry is 64 bits wide and the whole 64-bit entry is used
436 		 as a signed quantity, so we need to sign-extend the
437 		 computed value to 64 bits.  */
438 	      *(Elf64_Sxword *) reloc_addr = (Elf64_Sxword) (Elf32_Sword) value;
439 #  else
440 	      *reloc_addr = value;
441 #  endif
442 	    }
443 	  break;
444 # endif
445 
446 # ifndef RTLD_BOOTSTRAP
447 	case R_X86_64_64:
448 	  /* value + r_addend may be > 0xffffffff and R_X86_64_64
449 	     relocation updates the whole 64-bit entry.  */
450 	  *(Elf64_Addr *) reloc_addr = (Elf64_Addr) value + reloc->r_addend;
451 	  break;
452 #  ifndef __ILP32__
453 	case R_X86_64_SIZE32:
454 	  /* Set to symbol size plus addend.  */
455 	  value = sym->st_size;
456 #  endif
457 	  /* Fall through.  */
458 	case R_X86_64_32:
459 	  value += reloc->r_addend;
460 	  *(unsigned int *) reloc_addr = value;
461 
462 	  const char *fmt;
463 	  if (__glibc_unlikely (value > UINT_MAX))
464 	    {
465 	      const char *strtab;
466 
467 	      fmt = "\
468 %s: Symbol `%s' causes overflow in R_X86_64_32 relocation\n";
469 #  ifndef RESOLVE_CONFLICT_FIND_MAP
470 	    print_err:
471 #  endif
472 	      strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
473 
474 	      _dl_error_printf (fmt, RTLD_PROGNAME, strtab + refsym->st_name);
475 	    }
476 	  break;
477 #  ifndef RESOLVE_CONFLICT_FIND_MAP
478 	  /* Not needed for dl-conflict.c.  */
479 	case R_X86_64_PC32:
480 	  value += reloc->r_addend - (ElfW(Addr)) reloc_addr;
481 	  *(unsigned int *) reloc_addr = value;
482 	  if (__glibc_unlikely (value != (int) value))
483 	    {
484 	      fmt = "\
485 %s: Symbol `%s' causes overflow in R_X86_64_PC32 relocation\n";
486 	      goto print_err;
487 	    }
488 	  break;
489 	case R_X86_64_COPY:
490 	  if (sym == NULL)
491 	    /* This can happen in trace mode if an object could not be
492 	       found.  */
493 	    break;
494 	  memcpy (reloc_addr_arg, (void *) value,
495 		  MIN (sym->st_size, refsym->st_size));
496 	  if (__glibc_unlikely (sym->st_size > refsym->st_size)
497 	      || (__glibc_unlikely (sym->st_size < refsym->st_size)
498 		  && GLRO(dl_verbose)))
499 	    {
500 	      fmt = "\
501 %s: Symbol `%s' has different size in shared object, consider re-linking\n";
502 	      goto print_err;
503 	    }
504 	  break;
505 #  endif
506 	case R_X86_64_IRELATIVE:
507 	  value = map->l_addr + reloc->r_addend;
508 	  if (__glibc_likely (!skip_ifunc))
509 	    value = ((ElfW(Addr) (*) (void)) value) ();
510 	  *reloc_addr = value;
511 	  break;
512 	default:
513 	  _dl_reloc_bad_type (map, r_type, 0);
514 	  break;
515 # endif
516 	}
517     }
518 }
519 
520 static inline void
521 __attribute ((always_inline))
elf_machine_rela_relative(ElfW (Addr)l_addr,const ElfW (Rela)* reloc,void * const reloc_addr_arg)522 elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
523 			   void *const reloc_addr_arg)
524 {
525   ElfW(Addr) *const reloc_addr = reloc_addr_arg;
526 #if !defined RTLD_BOOTSTRAP
527   /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64
528      relocation updates the whole 64-bit entry.  */
529   if (__glibc_unlikely (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE64))
530     *(Elf64_Addr *) reloc_addr = (Elf64_Addr) l_addr + reloc->r_addend;
531   else
532 #endif
533     {
534       assert (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE);
535       *reloc_addr = l_addr + reloc->r_addend;
536     }
537 }
538 
539 static inline void
540 __attribute ((always_inline))
elf_machine_lazy_rel(struct link_map * map,struct r_scope_elem * scope[],ElfW (Addr)l_addr,const ElfW (Rela)* reloc,int skip_ifunc)541 elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
542 		      ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
543 		      int skip_ifunc)
544 {
545   ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
546   const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
547 
548   /* Check for unexpected PLT reloc type.  */
549   if (__glibc_likely (r_type == R_X86_64_JUMP_SLOT))
550     {
551       /* Prelink has been deprecated.  */
552       if (__glibc_likely (map->l_mach.plt == 0))
553 	*reloc_addr += l_addr;
554       else
555 	*reloc_addr =
556 	  map->l_mach.plt
557 	  + (((ElfW(Addr)) reloc_addr) - map->l_mach.gotplt) * 2;
558     }
559   else if (__glibc_likely (r_type == R_X86_64_TLSDESC))
560     {
561       const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info);
562       const ElfW (Sym) *symtab = (const void *)D_PTR (map, l_info[DT_SYMTAB]);
563       const ElfW (Sym) *sym = &symtab[symndx];
564       const struct r_found_version *version = NULL;
565 
566       if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
567 	{
568 	  const ElfW (Half) *vernum =
569 	    (const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
570 	  version = &map->l_versions[vernum[symndx] & 0x7fff];
571 	}
572 
573       /* Always initialize TLS descriptors completely at load time, in
574 	 case static TLS is allocated for it that requires locking.  */
575       elf_machine_rela (map, scope, reloc, sym, version, reloc_addr, skip_ifunc);
576     }
577   else if (__glibc_unlikely (r_type == R_X86_64_IRELATIVE))
578     {
579       ElfW(Addr) value = map->l_addr + reloc->r_addend;
580       if (__glibc_likely (!skip_ifunc))
581 	value = ((ElfW(Addr) (*) (void)) value) ();
582       *reloc_addr = value;
583     }
584   else
585     _dl_reloc_bad_type (map, r_type, 1);
586 }
587 
588 #endif /* RESOLVE_MAP */
589