Simplify strncat.
[glibc.git] / sysdeps / mips / dl-machine.h
blob5000d2a300ba32486689dc7b4d036b3aaf6b1abe
1 /* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
2 Copyright (C) 1996-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library. If not, see
18 <http://www.gnu.org/licenses/>. */
20 /* FIXME: Profiling of shared libraries is not implemented yet. */
21 #ifndef dl_machine_h
22 #define dl_machine_h
24 #define ELF_MACHINE_NAME "MIPS"
26 #include <entry.h>
28 #ifndef ENTRY_POINT
29 #error ENTRY_POINT needs to be defined for MIPS.
30 #endif
32 #include <sgidefs.h>
33 #include <sys/asm.h>
34 #include <dl-tls.h>
36 /* The offset of gp from GOT might be system-dependent. It's set by
37 ld. The same value is also */
38 #define OFFSET_GP_GOT 0x7ff0
40 #ifndef _RTLD_PROLOGUE
41 # define _RTLD_PROLOGUE(entry) \
42 ".globl\t" __STRING(entry) "\n\t" \
43 ".ent\t" __STRING(entry) "\n\t" \
44 ".type\t" __STRING(entry) ", @function\n" \
45 __STRING(entry) ":\n\t"
46 #endif
48 #ifndef _RTLD_EPILOGUE
49 # define _RTLD_EPILOGUE(entry) \
50 ".end\t" __STRING(entry) "\n\t" \
51 ".size\t" __STRING(entry) ", . - " __STRING(entry) "\n\t"
52 #endif
54 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
55 This only makes sense on MIPS when using PLTs, so choose the
56 PLT relocation (not encountered when not using PLTs). */
57 #define ELF_MACHINE_JMP_SLOT R_MIPS_JUMP_SLOT
58 #define elf_machine_type_class(type) \
59 ((((type) == ELF_MACHINE_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
60 | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
62 #define ELF_MACHINE_PLT_REL 1
63 #define ELF_MACHINE_NO_REL 0
64 #define ELF_MACHINE_NO_RELA 0
66 /* Translate a processor specific dynamic tag to the index
67 in l_info array. */
68 #define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
70 /* If there is a DT_MIPS_RLD_MAP entry in the dynamic section, fill it in
71 with the run-time address of the r_debug structure */
72 #define ELF_MACHINE_DEBUG_SETUP(l,r) \
73 do { if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
74 *(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
75 (ElfW(Addr)) (r); \
76 } while (0)
78 #if ((defined __mips_nan2008 && !defined HAVE_MIPS_NAN2008) \
79 || (!defined __mips_nan2008 && defined HAVE_MIPS_NAN2008))
80 # error "Configuration inconsistency: __mips_nan2008 != HAVE_MIPS_NAN2008, overridden CFLAGS?"
81 #endif
82 #ifdef __mips_nan2008
83 # define ELF_MACHINE_NAN2008 EF_MIPS_NAN2008
84 #else
85 # define ELF_MACHINE_NAN2008 0
86 #endif
88 /* Return nonzero iff ELF header is compatible with the running host. */
89 static inline int __attribute_used__
90 elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
92 #if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32
93 /* Don't link o32 and n32 together. */
94 if (((ehdr->e_flags & EF_MIPS_ABI2) != 0) != (_MIPS_SIM == _ABIN32))
95 return 0;
96 #endif
98 /* Don't link 2008-NaN and legacy-NaN objects together. */
99 if ((ehdr->e_flags & EF_MIPS_NAN2008) != ELF_MACHINE_NAN2008)
100 return 0;
102 switch (ehdr->e_machine)
104 case EM_MIPS:
105 case EM_MIPS_RS3_LE:
106 return 1;
107 default:
108 return 0;
112 static inline ElfW(Addr) *
113 elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
115 /* FIXME: the offset of gp from GOT may be system-dependent. */
116 return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
119 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
120 first element of the GOT. This must be inlined in a function which
121 uses global data. We assume its $gp points to the primary GOT. */
122 static inline ElfW(Addr)
123 elf_machine_dynamic (void)
125 register ElfW(Addr) gp __asm__ ("$28");
126 return *elf_mips_got_from_gpreg (gp);
129 #define STRINGXP(X) __STRING(X)
130 #define STRINGXV(X) STRINGV_(X)
131 #define STRINGV_(...) # __VA_ARGS__
133 /* Return the run-time load address of the shared object. */
134 static inline ElfW(Addr)
135 elf_machine_load_address (void)
137 ElfW(Addr) addr;
138 #ifndef __mips16
139 asm (" .set noreorder\n"
140 " " STRINGXP (PTR_LA) " %0, 0f\n"
141 " bltzal $0, 0f\n"
142 " nop\n"
143 "0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
144 " .set reorder\n"
145 : "=r" (addr)
146 : /* No inputs */
147 : "$31");
148 #else
149 ElfW(Addr) tmp;
150 asm (" .set noreorder\n"
151 " move %1,$gp\n"
152 " lw %1,%%got(0f)(%1)\n"
153 "0: .fill 0\n" /* Clear the ISA bit on 0:. */
154 " la %0,0b\n"
155 " addiu %1,%%lo(0b)\n"
156 " subu %0,%1\n"
157 " .set reorder\n"
158 : "=d" (addr), "=d" (tmp)
159 : /* No inputs */);
160 #endif
161 return addr;
164 /* The MSB of got[1] of a gnu object is set to identify gnu objects. */
165 #if _MIPS_SIM == _ABI64
166 # define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L
167 #else
168 # define ELF_MIPS_GNU_GOT1_MASK 0x80000000L
169 #endif
171 /* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope
172 fiddles with global data. */
173 #define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
174 do { \
175 struct link_map *map = &bootstrap_map; \
176 ElfW(Sym) *sym; \
177 ElfW(Addr) *got; \
178 int i, n; \
180 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \
182 if (__builtin_expect (map->l_addr == 0, 1)) \
183 break; \
185 /* got[0] is reserved. got[1] is also reserved for the dynamic object \
186 generated by gnu ld. Skip these reserved entries from \
187 relocation. */ \
188 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
189 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
191 /* Add the run-time displacement to all local got entries. */ \
192 while (i < n) \
193 got[i++] += map->l_addr; \
195 /* Handle global got entries. */ \
196 got += n; \
197 sym = (ElfW(Sym) *) D_PTR(map, l_info[DT_SYMTAB]) \
198 + map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
199 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val \
200 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); \
202 while (i--) \
204 if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_COMMON) \
205 *got = map->l_addr + sym->st_value; \
206 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \
207 && *got != sym->st_value) \
208 *got += map->l_addr; \
209 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION) \
211 if (sym->st_other == 0) \
212 *got += map->l_addr; \
214 else \
215 *got = map->l_addr + sym->st_value; \
217 got++; \
218 sym++; \
220 } while(0)
223 /* Mask identifying addresses reserved for the user program,
224 where the dynamic linker should not map anything. */
225 #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
228 /* Initial entry point code for the dynamic linker.
229 The C function `_dl_start' is the real entry point;
230 its return value is the user program's entry point.
231 Note how we have to be careful about two things:
233 1) That we allocate a minimal stack of 24 bytes for
234 every function call, the MIPS ABI states that even
235 if all arguments are passed in registers the procedure
236 called can use the 16 byte area pointed to by $sp
237 when it is called to store away the arguments passed
238 to it.
240 2) That under Unix the entry is named __start
241 and not just plain _start. */
243 #ifndef __mips16
244 # define RTLD_START asm (\
245 ".text\n\
246 " _RTLD_PROLOGUE(ENTRY_POINT) "\
247 " STRINGXV(SETUP_GPX($25)) "\n\
248 " STRINGXV(SETUP_GPX64($18,$25)) "\n\
249 # i386 ABI book says that the first entry of GOT holds\n\
250 # the address of the dynamic structure. Though MIPS ABI\n\
251 # doesn't say nothing about this, I emulate this here.\n\
252 " STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
253 # Subtract OFFSET_GP_GOT\n\
254 " STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
255 move $4, $29\n\
256 " STRINGXP(PTR_SUBIU) " $29, 16\n\
258 " STRINGXP(PTR_LA) " $8, .Lcoff\n\
259 bltzal $8, .Lcoff\n\
260 .Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
262 " STRINGXP(PTR_LA) " $25, _dl_start\n\
263 " STRINGXP(PTR_ADDU) " $25, $8\n\
264 jalr $25\n\
266 " STRINGXP(PTR_ADDIU) " $29, 16\n\
267 # Get the value of label '_dl_start_user' in t9 ($25).\n\
268 " STRINGXP(PTR_LA) " $25, _dl_start_user\n\
269 " _RTLD_EPILOGUE(ENTRY_POINT) "\
272 " _RTLD_PROLOGUE(_dl_start_user) "\
273 " STRINGXP(SETUP_GP) "\n\
274 " STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
275 move $16, $28\n\
276 # Save the user entry point address in a saved register.\n\
277 move $17, $2\n\
278 # See if we were run as a command with the executable file\n\
279 # name as an extra leading argument.\n\
280 lw $2, _dl_skip_args\n\
281 beq $2, $0, 1f\n\
282 # Load the original argument count.\n\
283 " STRINGXP(PTR_L) " $4, 0($29)\n\
284 # Subtract _dl_skip_args from it.\n\
285 subu $4, $2\n\
286 # Adjust the stack pointer to skip _dl_skip_args words.\n\
287 sll $2, " STRINGXP (PTRLOG) "\n\
288 " STRINGXP(PTR_ADDU) " $29, $2\n\
289 # Save back the modified argument count.\n\
290 " STRINGXP(PTR_S) " $4, 0($29)\n\
291 1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
292 " STRINGXP(PTR_L) " $4, _rtld_local\n\
293 " STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
294 " STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
295 sll $7, $5, " STRINGXP (PTRLOG) "\n\
296 " STRINGXP(PTR_ADDU) " $7, $7, $6\n\
297 " STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
298 # Make sure the stack pointer is aligned for _dl_init.\n\
299 and $2, $29, -2 * " STRINGXP(SZREG) "\n\
300 move $8, $29\n\
301 " STRINGXP(PTR_SUBIU) " $29, $2, 32\n\
302 " STRINGXP(PTR_S) " $8, (32 - " STRINGXP(SZREG) ")($29)\n\
303 " STRINGXP(SAVE_GP(16)) "\n\
304 # Call the function to run the initializers.\n\
305 jal _dl_init\n\
306 # Restore the stack pointer for _start.\n\
307 " STRINGXP(PTR_L) " $29, (32 - " STRINGXP(SZREG) ")($29)\n\
308 # Pass our finalizer function to the user in $2 as per ELF ABI.\n\
309 " STRINGXP(PTR_LA) " $2, _dl_fini\n\
310 # Jump to the user entry point.\n\
311 move $25, $17\n\
312 jr $25\n\t"\
313 _RTLD_EPILOGUE(_dl_start_user)\
314 ".previous"\
317 #else /* __mips16 */
318 /* MIPS16 version. We currently only support O32 under MIPS16; the proper
319 assembly preprocessor abstractions will need to be added if other ABIs
320 are to be supported. */
322 # define RTLD_START asm (\
323 ".text\n\
324 .set mips16\n\
325 " _RTLD_PROLOGUE (ENTRY_POINT) "\
326 # Construct GP value in $3.\n\
327 li $3, %hi(_gp_disp)\n\
328 addiu $4, $pc, %lo(_gp_disp)\n\
329 sll $3, 16\n\
330 addu $3, $4\n\
331 move $28, $3\n\
332 lw $4, %got(_DYNAMIC)($3)\n\
333 sw $4, -0x7ff0($3)\n\
334 move $4, $sp\n\
335 addiu $sp, -16\n\
336 # _dl_start() is sufficiently near to use pc-relative\n\
337 # load address.\n\
338 la $3, _dl_start\n\
339 move $25, $3\n\
340 jalr $3\n\
341 addiu $sp, 16\n\
342 " _RTLD_EPILOGUE (ENTRY_POINT) "\
345 " _RTLD_PROLOGUE (_dl_start_user) "\
346 li $16, %hi(_gp_disp)\n\
347 addiu $4, $pc, %lo(_gp_disp)\n\
348 sll $16, 16\n\
349 addu $16, $4\n\
350 move $17, $2\n\
351 move $28, $16\n\
352 lw $4, %got(_dl_skip_args)($16)\n\
353 lw $4, 0($4)\n\
354 beqz $4, 1f\n\
355 # Load the original argument count.\n\
356 lw $5, 0($sp)\n\
357 # Subtract _dl_skip_args from it.\n\
358 subu $5, $4\n\
359 # Adjust the stack pointer to skip _dl_skip_args words.\n\
360 sll $4, " STRINGXP (PTRLOG) "\n\
361 move $6, $sp\n\
362 addu $6, $4\n\
363 move $sp, $6\n\
364 # Save back the modified argument count.\n\
365 sw $5, 0($sp)\n\
366 1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
367 lw $4, %got(_rtld_local)($16)\n\
368 lw $4, 0($4)\n\
369 lw $5, 0($sp)\n\
370 addiu $6, $sp, " STRINGXP (PTRSIZE) "\n\
371 sll $7, $5, " STRINGXP (PTRLOG) "\n\
372 addu $7, $6\n\
373 addu $7, " STRINGXP (PTRSIZE) "\n\
374 # Make sure the stack pointer is aligned for _dl_init.\n\
375 li $2, 2 * " STRINGXP (SZREG) "\n\
376 neg $2, $2\n\
377 move $3, $sp\n\
378 and $2, $3\n\
379 sw $3, -" STRINGXP (SZREG) "($2)\n\
380 addiu $2, -32\n\
381 move $sp, $2\n\
382 sw $16, 16($sp)\n\
383 # Call the function to run the initializers.\n\
384 lw $2, %call16(_dl_init)($16)\n\
385 move $25, $2\n\
386 jalr $2\n\
387 # Restore the stack pointer for _start.\n\
388 lw $2, 32-" STRINGXP (SZREG) "($sp)\n\
389 move $sp, $2\n\
390 move $28, $16\n\
391 # Pass our finalizer function to the user in $2 as per ELF ABI.\n\
392 lw $2, %call16(_dl_fini)($16)\n\
393 # Jump to the user entry point.\n\
394 move $25, $17\n\
395 jr $17\n\t"\
396 _RTLD_EPILOGUE (_dl_start_user)\
397 ".previous"\
400 #endif /* __mips16 */
402 /* Names of the architecture-specific auditing callback functions. */
403 # if _MIPS_SIM == _ABIO32
404 # define ARCH_LA_PLTENTER mips_o32_gnu_pltenter
405 # define ARCH_LA_PLTEXIT mips_o32_gnu_pltexit
406 # elif _MIPS_SIM == _ABIN32
407 # define ARCH_LA_PLTENTER mips_n32_gnu_pltenter
408 # define ARCH_LA_PLTEXIT mips_n32_gnu_pltexit
409 # else
410 # define ARCH_LA_PLTENTER mips_n64_gnu_pltenter
411 # define ARCH_LA_PLTEXIT mips_n64_gnu_pltexit
412 # endif
414 /* We define an initialization function. This is called very early in
415 _dl_sysdep_start. */
416 #define DL_PLATFORM_INIT dl_platform_init ()
418 static inline void __attribute__ ((unused))
419 dl_platform_init (void)
421 if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
422 /* Avoid an empty string which would disturb us. */
423 GLRO(dl_platform) = NULL;
426 /* For a non-writable PLT, rewrite the .got.plt entry at RELOC_ADDR to
427 point at the symbol with address VALUE. For a writable PLT, rewrite
428 the corresponding PLT entry instead. */
429 static inline ElfW(Addr)
430 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
431 const ElfW(Rel) *reloc,
432 ElfW(Addr) *reloc_addr, ElfW(Addr) value)
434 return *reloc_addr = value;
437 static inline ElfW(Addr)
438 elf_machine_plt_value (struct link_map *map, const ElfW(Rel) *reloc,
439 ElfW(Addr) value)
441 return value;
444 /* The semantics of zero/non-zero values of undefined symbols differs
445 depending on whether the non-PIC ABI is in use. Under the non-PIC
446 ABI, a non-zero value indicates that there is an address reference
447 to the symbol and thus it must always be resolved (except when
448 resolving a jump slot relocation) to the PLT entry whose address is
449 provided as the symbol's value; a zero value indicates that this
450 canonical-address behaviour is not required. Yet under the classic
451 MIPS psABI, a zero value indicates that there is an address
452 reference to the function and the dynamic linker must resolve the
453 symbol immediately upon loading. To avoid conflict, symbols for
454 which the dynamic linker must assume the non-PIC ABI semantics are
455 marked with the STO_MIPS_PLT flag. */
456 #define ELF_MACHINE_SYM_NO_MATCH(sym) \
457 ((sym)->st_shndx == SHN_UNDEF && !((sym)->st_other & STO_MIPS_PLT))
459 #endif /* !dl_machine_h */
461 #ifdef RESOLVE_MAP
463 /* Perform a relocation described by R_INFO at the location pointed to
464 by RELOC_ADDR. SYM is the relocation symbol specified by R_INFO and
465 MAP is the object containing the reloc. */
467 auto inline void
468 __attribute__ ((always_inline))
469 elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
470 const ElfW(Sym) *sym, const struct r_found_version *version,
471 void *reloc_addr, ElfW(Addr) r_addend, int inplace_p)
473 const unsigned long int r_type = ELFW(R_TYPE) (r_info);
474 ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;
476 #if !defined RTLD_BOOTSTRAP && !defined SHARED
477 /* This is defined in rtld.c, but nowhere in the static libc.a;
478 make the reference weak so static programs can still link. This
479 declaration cannot be done when compiling rtld.c (i.e. #ifdef
480 RTLD_BOOTSTRAP) because rtld.c contains the common defn for
481 _dl_rtld_map, which is incompatible with a weak decl in the same
482 file. */
483 weak_extern (GL(dl_rtld_map));
484 #endif
486 switch (r_type)
488 #if !defined (RTLD_BOOTSTRAP)
489 # if _MIPS_SIM == _ABI64
490 case R_MIPS_TLS_DTPMOD64:
491 case R_MIPS_TLS_DTPREL64:
492 case R_MIPS_TLS_TPREL64:
493 # else
494 case R_MIPS_TLS_DTPMOD32:
495 case R_MIPS_TLS_DTPREL32:
496 case R_MIPS_TLS_TPREL32:
497 # endif
499 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
501 switch (r_type)
503 case R_MIPS_TLS_DTPMOD64:
504 case R_MIPS_TLS_DTPMOD32:
505 if (sym_map)
506 *addr_field = sym_map->l_tls_modid;
507 break;
509 case R_MIPS_TLS_DTPREL64:
510 case R_MIPS_TLS_DTPREL32:
511 if (sym)
513 if (inplace_p)
514 r_addend = *addr_field;
515 *addr_field = r_addend + TLS_DTPREL_VALUE (sym);
517 break;
519 case R_MIPS_TLS_TPREL32:
520 case R_MIPS_TLS_TPREL64:
521 if (sym)
523 CHECK_STATIC_TLS (map, sym_map);
524 if (inplace_p)
525 r_addend = *addr_field;
526 *addr_field = r_addend + TLS_TPREL_VALUE (sym_map, sym);
528 break;
531 break;
533 #endif
535 #if _MIPS_SIM == _ABI64
536 case (R_MIPS_64 << 8) | R_MIPS_REL32:
537 #else
538 case R_MIPS_REL32:
539 #endif
541 int symidx = ELFW(R_SYM) (r_info);
542 ElfW(Addr) reloc_value;
544 if (inplace_p)
545 /* Support relocations on mis-aligned offsets. */
546 __builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
547 else
548 reloc_value = r_addend;
550 if (symidx)
552 const ElfW(Word) gotsym
553 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
555 if ((ElfW(Word))symidx < gotsym)
557 /* This wouldn't work for a symbol imported from other
558 libraries for which there's no GOT entry, but MIPS
559 requires every symbol referenced in a dynamic
560 relocation to have a GOT entry in the primary GOT,
561 so we only get here for locally-defined symbols.
562 For section symbols, we should *NOT* be adding
563 sym->st_value (per the definition of the meaning of
564 S in reloc expressions in the ELF64 MIPS ABI),
565 since it should have already been added to
566 reloc_value by the linker, but older versions of
567 GNU ld didn't add it, and newer versions don't emit
568 useless relocations to section symbols any more, so
569 it is safe to keep on adding sym->st_value, even
570 though it's not ABI compliant. Some day we should
571 bite the bullet and stop doing this. */
572 #ifndef RTLD_BOOTSTRAP
573 if (map != &GL(dl_rtld_map))
574 #endif
575 reloc_value += sym->st_value + map->l_addr;
577 else
579 #ifndef RTLD_BOOTSTRAP
580 const ElfW(Addr) *got
581 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
582 const ElfW(Word) local_gotno
583 = (const ElfW(Word))
584 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
586 reloc_value += got[symidx + local_gotno - gotsym];
587 #endif
590 else
591 #ifndef RTLD_BOOTSTRAP
592 if (map != &GL(dl_rtld_map))
593 #endif
594 reloc_value += map->l_addr;
596 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
598 break;
599 #ifndef RTLD_BOOTSTRAP
600 #if _MIPS_SIM == _ABI64
601 case (R_MIPS_64 << 8) | R_MIPS_GLOB_DAT:
602 #else
603 case R_MIPS_GLOB_DAT:
604 #endif
606 int symidx = ELFW(R_SYM) (r_info);
607 const ElfW(Word) gotsym
608 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
610 if (__builtin_expect ((ElfW(Word)) symidx >= gotsym, 1))
612 const ElfW(Addr) *got
613 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
614 const ElfW(Word) local_gotno
615 = ((const ElfW(Word))
616 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val);
618 ElfW(Addr) reloc_value = got[symidx + local_gotno - gotsym];
619 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
622 break;
623 #endif
624 case R_MIPS_NONE: /* Alright, Wilbur. */
625 break;
627 case R_MIPS_JUMP_SLOT:
629 struct link_map *sym_map;
630 ElfW(Addr) value;
632 /* The addend for a jump slot relocation must always be zero:
633 calls via the PLT always branch to the symbol's address and
634 not to the address plus a non-zero offset. */
635 if (r_addend != 0)
636 _dl_signal_error (0, map->l_name, NULL,
637 "found jump slot relocation with non-zero addend");
639 sym_map = RESOLVE_MAP (&sym, version, r_type);
640 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
641 *addr_field = value;
643 break;
646 case R_MIPS_COPY:
648 const ElfW(Sym) *const refsym = sym;
649 struct link_map *sym_map;
650 ElfW(Addr) value;
652 /* Calculate the address of the symbol. */
653 sym_map = RESOLVE_MAP (&sym, version, r_type);
654 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
656 if (__builtin_expect (sym == NULL, 0))
657 /* This can happen in trace mode if an object could not be
658 found. */
659 break;
660 if (__builtin_expect (sym->st_size > refsym->st_size, 0)
661 || (__builtin_expect (sym->st_size < refsym->st_size, 0)
662 && GLRO(dl_verbose)))
664 const char *strtab;
666 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
667 _dl_error_printf ("\
668 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
669 RTLD_PROGNAME, strtab + refsym->st_name);
671 memcpy (reloc_addr, (void *) value,
672 MIN (sym->st_size, refsym->st_size));
673 break;
676 #if _MIPS_SIM == _ABI64
677 case R_MIPS_64:
678 /* For full compliance with the ELF64 ABI, one must precede the
679 _REL32/_64 pair of relocations with a _64 relocation, such
680 that the in-place addend is read as a 64-bit value. IRIX
681 didn't pick up on this requirement, so we treat the
682 _REL32/_64 relocation as a 64-bit relocation even if it's by
683 itself. For ABI compliance, we ignore such _64 dummy
684 relocations. For RELA, this may be simply removed, since
685 it's totally unnecessary. */
686 if (ELFW(R_SYM) (r_info) == 0)
687 break;
688 /* Fall through. */
689 #endif
690 default:
691 _dl_reloc_bad_type (map, r_type, 0);
692 break;
696 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
697 MAP is the object containing the reloc. */
699 auto inline void
700 __attribute__ ((always_inline))
701 elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
702 const ElfW(Sym) *sym, const struct r_found_version *version,
703 void *const reloc_addr, int skip_ifunc)
705 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1);
708 auto inline void
709 __attribute__((always_inline))
710 elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
711 void *const reloc_addr)
713 /* XXX Nothing to do. There is no relative relocation, right? */
716 auto inline void
717 __attribute__((always_inline))
718 elf_machine_lazy_rel (struct link_map *map,
719 ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
720 int skip_ifunc)
722 ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
723 const unsigned int r_type = ELFW(R_TYPE) (reloc->r_info);
724 /* Check for unexpected PLT reloc type. */
725 if (__builtin_expect (r_type == R_MIPS_JUMP_SLOT, 1))
727 if (__builtin_expect (map->l_mach.plt, 0) == 0)
729 /* Nothing is required here since we only support lazy
730 relocation in executables. */
732 else
733 *reloc_addr = map->l_mach.plt;
735 else
736 _dl_reloc_bad_type (map, r_type, 1);
739 auto inline void
740 __attribute__ ((always_inline))
741 elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
742 const ElfW(Sym) *sym, const struct r_found_version *version,
743 void *const reloc_addr, int skip_ifunc)
745 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr,
746 reloc->r_addend, 0);
749 auto inline void
750 __attribute__((always_inline))
751 elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
752 void *const reloc_addr)
756 #ifndef RTLD_BOOTSTRAP
757 /* Relocate GOT. */
758 auto inline void
759 __attribute__((always_inline))
760 elf_machine_got_rel (struct link_map *map, int lazy)
762 ElfW(Addr) *got;
763 ElfW(Sym) *sym;
764 const ElfW(Half) *vernum;
765 int i, n, symidx;
767 #define RESOLVE_GOTSYM(sym,vernum,sym_index,reloc) \
768 ({ \
769 const ElfW(Sym) *ref = sym; \
770 const struct r_found_version *version __attribute__ ((unused)) \
771 = vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
772 struct link_map *sym_map; \
773 sym_map = RESOLVE_MAP (&ref, version, reloc); \
774 ref ? sym_map->l_addr + ref->st_value : 0; \
777 if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
778 vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
779 else
780 vernum = NULL;
782 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
784 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
785 /* The dynamic linker's local got entries have already been relocated. */
786 if (map != &GL(dl_rtld_map))
788 /* got[0] is reserved. got[1] is also reserved for the dynamic object
789 generated by gnu ld. Skip these reserved entries from relocation. */
790 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
792 /* Add the run-time displacement to all local got entries if
793 needed. */
794 if (__builtin_expect (map->l_addr != 0, 0))
796 while (i < n)
797 got[i++] += map->l_addr;
801 /* Handle global got entries. */
802 got += n;
803 /* Keep track of the symbol index. */
804 symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
805 sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx;
806 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
807 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
809 /* This loop doesn't handle Quickstart. */
810 while (i--)
812 if (sym->st_shndx == SHN_UNDEF)
814 if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC && sym->st_value
815 && !(sym->st_other & STO_MIPS_PLT))
817 if (lazy)
818 *got = sym->st_value + map->l_addr;
819 else
820 /* This is a lazy-binding stub, so we don't need the
821 canonical address. */
822 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
824 else
825 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
827 else if (sym->st_shndx == SHN_COMMON)
828 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
829 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
830 && *got != sym->st_value)
832 if (lazy)
833 *got += map->l_addr;
834 else
835 /* This is a lazy-binding stub, so we don't need the
836 canonical address. */
837 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
839 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
841 if (sym->st_other == 0)
842 *got += map->l_addr;
844 else
845 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
847 ++got;
848 ++sym;
849 ++symidx;
852 #undef RESOLVE_GOTSYM
854 #endif
856 /* Set up the loaded object described by L so its stub function
857 will jump to the on-demand fixup code __dl_runtime_resolve. */
859 auto inline int
860 __attribute__((always_inline))
861 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
863 # ifndef RTLD_BOOTSTRAP
864 ElfW(Addr) *got;
865 extern void _dl_runtime_resolve (ElfW(Word));
866 extern void _dl_runtime_pltresolve (void);
867 extern int _dl_mips_gnu_objects;
869 if (lazy)
871 /* The GOT entries for functions have not yet been filled in.
872 Their initial contents will arrange when called to put an
873 offset into the .dynsym section in t8, the return address
874 in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
875 got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
877 /* This function will get called to fix up the GOT entry indicated by
878 the register t8, and then jump to the resolved address. */
879 got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
881 /* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
882 of got[1] of a gnu object is set to identify gnu objects.
883 Where we can store l for non gnu objects? XXX */
884 if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
885 got[1] = ((ElfW(Addr)) l | ELF_MIPS_GNU_GOT1_MASK);
886 else
887 _dl_mips_gnu_objects = 0;
890 /* Relocate global offset table. */
891 elf_machine_got_rel (l, lazy);
893 /* If using PLTs, fill in the first two entries of .got.plt. */
894 if (l->l_info[DT_JMPREL] && lazy)
896 ElfW(Addr) *gotplt;
897 gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_MIPS (PLTGOT)]);
898 /* If a library is prelinked but we have to relocate anyway,
899 we have to be able to undo the prelinking of .got.plt.
900 The prelinker saved the address of .plt for us here. */
901 if (gotplt[1])
902 l->l_mach.plt = gotplt[1] + l->l_addr;
903 gotplt[0] = (ElfW(Addr)) &_dl_runtime_pltresolve;
904 gotplt[1] = (ElfW(Addr)) l;
907 # endif
908 return lazy;
911 #endif /* RESOLVE_MAP */