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[glibc.git] / sysdeps / mips / dl-machine.h
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1 /* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
2 Copyright (C) 1996-2015 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 /* Ensure that the old O32 FP64 ABI is never loaded, it is not supported
103 on linux. */
104 if (ehdr->e_flags & EF_MIPS_FP64)
105 return 0;
107 switch (ehdr->e_machine)
109 case EM_MIPS:
110 case EM_MIPS_RS3_LE:
111 return 1;
112 default:
113 return 0;
117 static inline ElfW(Addr) *
118 elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
120 /* FIXME: the offset of gp from GOT may be system-dependent. */
121 return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
124 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
125 first element of the GOT. This must be inlined in a function which
126 uses global data. We assume its $gp points to the primary GOT. */
127 static inline ElfW(Addr)
128 elf_machine_dynamic (void)
130 register ElfW(Addr) gp __asm__ ("$28");
131 return *elf_mips_got_from_gpreg (gp);
134 #define STRINGXP(X) __STRING(X)
135 #define STRINGXV(X) STRINGV_(X)
136 #define STRINGV_(...) # __VA_ARGS__
138 /* Return the run-time load address of the shared object. */
139 static inline ElfW(Addr)
140 elf_machine_load_address (void)
142 ElfW(Addr) addr;
143 #ifndef __mips16
144 asm (" .set noreorder\n"
145 " " STRINGXP (PTR_LA) " %0, 0f\n"
146 " bltzal $0, 0f\n"
147 " nop\n"
148 "0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
149 " .set reorder\n"
150 : "=r" (addr)
151 : /* No inputs */
152 : "$31");
153 #else
154 ElfW(Addr) tmp;
155 asm (" .set noreorder\n"
156 " move %1,$gp\n"
157 " lw %1,%%got(0f)(%1)\n"
158 "0: .fill 0\n" /* Clear the ISA bit on 0:. */
159 " la %0,0b\n"
160 " addiu %1,%%lo(0b)\n"
161 " subu %0,%1\n"
162 " .set reorder\n"
163 : "=d" (addr), "=d" (tmp)
164 : /* No inputs */);
165 #endif
166 return addr;
169 /* The MSB of got[1] of a gnu object is set to identify gnu objects. */
170 #if _MIPS_SIM == _ABI64
171 # define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L
172 #else
173 # define ELF_MIPS_GNU_GOT1_MASK 0x80000000L
174 #endif
176 /* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope
177 fiddles with global data. */
178 #define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
179 do { \
180 struct link_map *map = &bootstrap_map; \
181 ElfW(Sym) *sym; \
182 ElfW(Addr) *got; \
183 int i, n; \
185 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \
187 if (__builtin_expect (map->l_addr == 0, 1)) \
188 break; \
190 /* got[0] is reserved. got[1] is also reserved for the dynamic object \
191 generated by gnu ld. Skip these reserved entries from \
192 relocation. */ \
193 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
194 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
196 /* Add the run-time displacement to all local got entries. */ \
197 while (i < n) \
198 got[i++] += map->l_addr; \
200 /* Handle global got entries. */ \
201 got += n; \
202 sym = (ElfW(Sym) *) D_PTR(map, l_info[DT_SYMTAB]) \
203 + map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
204 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val \
205 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); \
207 while (i--) \
209 if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_COMMON) \
210 *got = map->l_addr + sym->st_value; \
211 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \
212 && *got != sym->st_value) \
213 *got += map->l_addr; \
214 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION) \
216 if (sym->st_other == 0) \
217 *got += map->l_addr; \
219 else \
220 *got = map->l_addr + sym->st_value; \
222 got++; \
223 sym++; \
225 } while(0)
228 /* Mask identifying addresses reserved for the user program,
229 where the dynamic linker should not map anything. */
230 #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
233 /* Initial entry point code for the dynamic linker.
234 The C function `_dl_start' is the real entry point;
235 its return value is the user program's entry point.
236 Note how we have to be careful about two things:
238 1) That we allocate a minimal stack of 24 bytes for
239 every function call, the MIPS ABI states that even
240 if all arguments are passed in registers the procedure
241 called can use the 16 byte area pointed to by $sp
242 when it is called to store away the arguments passed
243 to it.
245 2) That under Unix the entry is named __start
246 and not just plain _start. */
248 #ifndef __mips16
249 # define RTLD_START asm (\
250 ".text\n\
251 " _RTLD_PROLOGUE(ENTRY_POINT) "\
252 " STRINGXV(SETUP_GPX($25)) "\n\
253 " STRINGXV(SETUP_GPX64($18,$25)) "\n\
254 # i386 ABI book says that the first entry of GOT holds\n\
255 # the address of the dynamic structure. Though MIPS ABI\n\
256 # doesn't say nothing about this, I emulate this here.\n\
257 " STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
258 # Subtract OFFSET_GP_GOT\n\
259 " STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
260 move $4, $29\n\
261 " STRINGXP(PTR_SUBIU) " $29, 16\n\
263 " STRINGXP(PTR_LA) " $8, .Lcoff\n\
264 bltzal $8, .Lcoff\n\
265 .Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
267 " STRINGXP(PTR_LA) " $25, _dl_start\n\
268 " STRINGXP(PTR_ADDU) " $25, $8\n\
269 jalr $25\n\
271 " STRINGXP(PTR_ADDIU) " $29, 16\n\
272 # Get the value of label '_dl_start_user' in t9 ($25).\n\
273 " STRINGXP(PTR_LA) " $25, _dl_start_user\n\
274 " _RTLD_EPILOGUE(ENTRY_POINT) "\
277 " _RTLD_PROLOGUE(_dl_start_user) "\
278 " STRINGXP(SETUP_GP) "\n\
279 " STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
280 move $16, $28\n\
281 # Save the user entry point address in a saved register.\n\
282 move $17, $2\n\
283 # See if we were run as a command with the executable file\n\
284 # name as an extra leading argument.\n\
285 lw $2, _dl_skip_args\n\
286 beq $2, $0, 1f\n\
287 # Load the original argument count.\n\
288 " STRINGXP(PTR_L) " $4, 0($29)\n\
289 # Subtract _dl_skip_args from it.\n\
290 subu $4, $2\n\
291 # Adjust the stack pointer to skip _dl_skip_args words.\n\
292 sll $2, " STRINGXP (PTRLOG) "\n\
293 " STRINGXP(PTR_ADDU) " $29, $2\n\
294 # Save back the modified argument count.\n\
295 " STRINGXP(PTR_S) " $4, 0($29)\n\
296 1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
297 " STRINGXP(PTR_L) " $4, _rtld_local\n\
298 " STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
299 " STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
300 sll $7, $5, " STRINGXP (PTRLOG) "\n\
301 " STRINGXP(PTR_ADDU) " $7, $7, $6\n\
302 " STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
303 # Make sure the stack pointer is aligned for _dl_init.\n\
304 and $2, $29, -2 * " STRINGXP(SZREG) "\n\
305 move $8, $29\n\
306 " STRINGXP(PTR_SUBIU) " $29, $2, 32\n\
307 " STRINGXP(PTR_S) " $8, (32 - " STRINGXP(SZREG) ")($29)\n\
308 " STRINGXP(SAVE_GP(16)) "\n\
309 # Call the function to run the initializers.\n\
310 jal _dl_init\n\
311 # Restore the stack pointer for _start.\n\
312 " STRINGXP(PTR_L) " $29, (32 - " STRINGXP(SZREG) ")($29)\n\
313 # Pass our finalizer function to the user in $2 as per ELF ABI.\n\
314 " STRINGXP(PTR_LA) " $2, _dl_fini\n\
315 # Jump to the user entry point.\n\
316 move $25, $17\n\
317 jr $25\n\t"\
318 _RTLD_EPILOGUE(_dl_start_user)\
319 ".previous"\
322 #else /* __mips16 */
323 /* MIPS16 version. We currently only support O32 under MIPS16; the proper
324 assembly preprocessor abstractions will need to be added if other ABIs
325 are to be supported. */
327 # define RTLD_START asm (\
328 ".text\n\
329 .set mips16\n\
330 " _RTLD_PROLOGUE (ENTRY_POINT) "\
331 # Construct GP value in $3.\n\
332 li $3, %hi(_gp_disp)\n\
333 addiu $4, $pc, %lo(_gp_disp)\n\
334 sll $3, 16\n\
335 addu $3, $4\n\
336 move $28, $3\n\
337 lw $4, %got(_DYNAMIC)($3)\n\
338 sw $4, -0x7ff0($3)\n\
339 move $4, $sp\n\
340 addiu $sp, -16\n\
341 # _dl_start() is sufficiently near to use pc-relative\n\
342 # load address.\n\
343 la $3, _dl_start\n\
344 move $25, $3\n\
345 jalr $3\n\
346 addiu $sp, 16\n\
347 " _RTLD_EPILOGUE (ENTRY_POINT) "\
350 " _RTLD_PROLOGUE (_dl_start_user) "\
351 li $16, %hi(_gp_disp)\n\
352 addiu $4, $pc, %lo(_gp_disp)\n\
353 sll $16, 16\n\
354 addu $16, $4\n\
355 move $17, $2\n\
356 move $28, $16\n\
357 lw $4, %got(_dl_skip_args)($16)\n\
358 lw $4, 0($4)\n\
359 beqz $4, 1f\n\
360 # Load the original argument count.\n\
361 lw $5, 0($sp)\n\
362 # Subtract _dl_skip_args from it.\n\
363 subu $5, $4\n\
364 # Adjust the stack pointer to skip _dl_skip_args words.\n\
365 sll $4, " STRINGXP (PTRLOG) "\n\
366 move $6, $sp\n\
367 addu $6, $4\n\
368 move $sp, $6\n\
369 # Save back the modified argument count.\n\
370 sw $5, 0($sp)\n\
371 1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
372 lw $4, %got(_rtld_local)($16)\n\
373 lw $4, 0($4)\n\
374 lw $5, 0($sp)\n\
375 addiu $6, $sp, " STRINGXP (PTRSIZE) "\n\
376 sll $7, $5, " STRINGXP (PTRLOG) "\n\
377 addu $7, $6\n\
378 addu $7, " STRINGXP (PTRSIZE) "\n\
379 # Make sure the stack pointer is aligned for _dl_init.\n\
380 li $2, 2 * " STRINGXP (SZREG) "\n\
381 neg $2, $2\n\
382 move $3, $sp\n\
383 and $2, $3\n\
384 sw $3, -" STRINGXP (SZREG) "($2)\n\
385 addiu $2, -32\n\
386 move $sp, $2\n\
387 sw $16, 16($sp)\n\
388 # Call the function to run the initializers.\n\
389 lw $2, %call16(_dl_init)($16)\n\
390 move $25, $2\n\
391 jalr $2\n\
392 # Restore the stack pointer for _start.\n\
393 lw $2, 32-" STRINGXP (SZREG) "($sp)\n\
394 move $sp, $2\n\
395 move $28, $16\n\
396 # Pass our finalizer function to the user in $2 as per ELF ABI.\n\
397 lw $2, %call16(_dl_fini)($16)\n\
398 # Jump to the user entry point.\n\
399 move $25, $17\n\
400 jr $17\n\t"\
401 _RTLD_EPILOGUE (_dl_start_user)\
402 ".previous"\
405 #endif /* __mips16 */
407 /* Names of the architecture-specific auditing callback functions. */
408 # if _MIPS_SIM == _ABIO32
409 # define ARCH_LA_PLTENTER mips_o32_gnu_pltenter
410 # define ARCH_LA_PLTEXIT mips_o32_gnu_pltexit
411 # elif _MIPS_SIM == _ABIN32
412 # define ARCH_LA_PLTENTER mips_n32_gnu_pltenter
413 # define ARCH_LA_PLTEXIT mips_n32_gnu_pltexit
414 # else
415 # define ARCH_LA_PLTENTER mips_n64_gnu_pltenter
416 # define ARCH_LA_PLTEXIT mips_n64_gnu_pltexit
417 # endif
419 /* We define an initialization function. This is called very early in
420 _dl_sysdep_start. */
421 #define DL_PLATFORM_INIT dl_platform_init ()
423 static inline void __attribute__ ((unused))
424 dl_platform_init (void)
426 if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
427 /* Avoid an empty string which would disturb us. */
428 GLRO(dl_platform) = NULL;
431 /* For a non-writable PLT, rewrite the .got.plt entry at RELOC_ADDR to
432 point at the symbol with address VALUE. For a writable PLT, rewrite
433 the corresponding PLT entry instead. */
434 static inline ElfW(Addr)
435 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
436 const ElfW(Rel) *reloc,
437 ElfW(Addr) *reloc_addr, ElfW(Addr) value)
439 return *reloc_addr = value;
442 static inline ElfW(Addr)
443 elf_machine_plt_value (struct link_map *map, const ElfW(Rel) *reloc,
444 ElfW(Addr) value)
446 return value;
449 /* The semantics of zero/non-zero values of undefined symbols differs
450 depending on whether the non-PIC ABI is in use. Under the non-PIC
451 ABI, a non-zero value indicates that there is an address reference
452 to the symbol and thus it must always be resolved (except when
453 resolving a jump slot relocation) to the PLT entry whose address is
454 provided as the symbol's value; a zero value indicates that this
455 canonical-address behaviour is not required. Yet under the classic
456 MIPS psABI, a zero value indicates that there is an address
457 reference to the function and the dynamic linker must resolve the
458 symbol immediately upon loading. To avoid conflict, symbols for
459 which the dynamic linker must assume the non-PIC ABI semantics are
460 marked with the STO_MIPS_PLT flag. */
461 #define ELF_MACHINE_SYM_NO_MATCH(sym) \
462 ((sym)->st_shndx == SHN_UNDEF && !((sym)->st_other & STO_MIPS_PLT))
464 #endif /* !dl_machine_h */
466 #ifdef RESOLVE_MAP
468 /* Perform a relocation described by R_INFO at the location pointed to
469 by RELOC_ADDR. SYM is the relocation symbol specified by R_INFO and
470 MAP is the object containing the reloc. */
472 auto inline void
473 __attribute__ ((always_inline))
474 elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
475 const ElfW(Sym) *sym, const struct r_found_version *version,
476 void *reloc_addr, ElfW(Addr) r_addend, int inplace_p)
478 const unsigned long int r_type = ELFW(R_TYPE) (r_info);
479 ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;
481 #if !defined RTLD_BOOTSTRAP && !defined SHARED
482 /* This is defined in rtld.c, but nowhere in the static libc.a;
483 make the reference weak so static programs can still link. This
484 declaration cannot be done when compiling rtld.c (i.e. #ifdef
485 RTLD_BOOTSTRAP) because rtld.c contains the common defn for
486 _dl_rtld_map, which is incompatible with a weak decl in the same
487 file. */
488 weak_extern (GL(dl_rtld_map));
489 #endif
491 switch (r_type)
493 #if !defined (RTLD_BOOTSTRAP)
494 # if _MIPS_SIM == _ABI64
495 case R_MIPS_TLS_DTPMOD64:
496 case R_MIPS_TLS_DTPREL64:
497 case R_MIPS_TLS_TPREL64:
498 # else
499 case R_MIPS_TLS_DTPMOD32:
500 case R_MIPS_TLS_DTPREL32:
501 case R_MIPS_TLS_TPREL32:
502 # endif
504 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
506 switch (r_type)
508 case R_MIPS_TLS_DTPMOD64:
509 case R_MIPS_TLS_DTPMOD32:
510 if (sym_map)
511 *addr_field = sym_map->l_tls_modid;
512 break;
514 case R_MIPS_TLS_DTPREL64:
515 case R_MIPS_TLS_DTPREL32:
516 if (sym)
518 if (inplace_p)
519 r_addend = *addr_field;
520 *addr_field = r_addend + TLS_DTPREL_VALUE (sym);
522 break;
524 case R_MIPS_TLS_TPREL32:
525 case R_MIPS_TLS_TPREL64:
526 if (sym)
528 CHECK_STATIC_TLS (map, sym_map);
529 if (inplace_p)
530 r_addend = *addr_field;
531 *addr_field = r_addend + TLS_TPREL_VALUE (sym_map, sym);
533 break;
536 break;
538 #endif
540 #if _MIPS_SIM == _ABI64
541 case (R_MIPS_64 << 8) | R_MIPS_REL32:
542 #else
543 case R_MIPS_REL32:
544 #endif
546 int symidx = ELFW(R_SYM) (r_info);
547 ElfW(Addr) reloc_value;
549 if (inplace_p)
550 /* Support relocations on mis-aligned offsets. */
551 __builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
552 else
553 reloc_value = r_addend;
555 if (symidx)
557 const ElfW(Word) gotsym
558 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
560 if ((ElfW(Word))symidx < gotsym)
562 /* This wouldn't work for a symbol imported from other
563 libraries for which there's no GOT entry, but MIPS
564 requires every symbol referenced in a dynamic
565 relocation to have a GOT entry in the primary GOT,
566 so we only get here for locally-defined symbols.
567 For section symbols, we should *NOT* be adding
568 sym->st_value (per the definition of the meaning of
569 S in reloc expressions in the ELF64 MIPS ABI),
570 since it should have already been added to
571 reloc_value by the linker, but older versions of
572 GNU ld didn't add it, and newer versions don't emit
573 useless relocations to section symbols any more, so
574 it is safe to keep on adding sym->st_value, even
575 though it's not ABI compliant. Some day we should
576 bite the bullet and stop doing this. */
577 #ifndef RTLD_BOOTSTRAP
578 if (map != &GL(dl_rtld_map))
579 #endif
580 reloc_value += sym->st_value + map->l_addr;
582 else
584 #ifndef RTLD_BOOTSTRAP
585 const ElfW(Addr) *got
586 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
587 const ElfW(Word) local_gotno
588 = (const ElfW(Word))
589 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
591 reloc_value += got[symidx + local_gotno - gotsym];
592 #endif
595 else
596 #ifndef RTLD_BOOTSTRAP
597 if (map != &GL(dl_rtld_map))
598 #endif
599 reloc_value += map->l_addr;
601 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
603 break;
604 #ifndef RTLD_BOOTSTRAP
605 #if _MIPS_SIM == _ABI64
606 case (R_MIPS_64 << 8) | R_MIPS_GLOB_DAT:
607 #else
608 case R_MIPS_GLOB_DAT:
609 #endif
611 int symidx = ELFW(R_SYM) (r_info);
612 const ElfW(Word) gotsym
613 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
615 if (__builtin_expect ((ElfW(Word)) symidx >= gotsym, 1))
617 const ElfW(Addr) *got
618 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
619 const ElfW(Word) local_gotno
620 = ((const ElfW(Word))
621 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val);
623 ElfW(Addr) reloc_value = got[symidx + local_gotno - gotsym];
624 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
627 break;
628 #endif
629 case R_MIPS_NONE: /* Alright, Wilbur. */
630 break;
632 case R_MIPS_JUMP_SLOT:
634 struct link_map *sym_map;
635 ElfW(Addr) value;
637 /* The addend for a jump slot relocation must always be zero:
638 calls via the PLT always branch to the symbol's address and
639 not to the address plus a non-zero offset. */
640 if (r_addend != 0)
641 _dl_signal_error (0, map->l_name, NULL,
642 "found jump slot relocation with non-zero addend");
644 sym_map = RESOLVE_MAP (&sym, version, r_type);
645 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
646 *addr_field = value;
648 break;
651 case R_MIPS_COPY:
653 const ElfW(Sym) *const refsym = sym;
654 struct link_map *sym_map;
655 ElfW(Addr) value;
657 /* Calculate the address of the symbol. */
658 sym_map = RESOLVE_MAP (&sym, version, r_type);
659 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
661 if (__builtin_expect (sym == NULL, 0))
662 /* This can happen in trace mode if an object could not be
663 found. */
664 break;
665 if (__builtin_expect (sym->st_size > refsym->st_size, 0)
666 || (__builtin_expect (sym->st_size < refsym->st_size, 0)
667 && GLRO(dl_verbose)))
669 const char *strtab;
671 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
672 _dl_error_printf ("\
673 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
674 RTLD_PROGNAME, strtab + refsym->st_name);
676 memcpy (reloc_addr, (void *) value,
677 MIN (sym->st_size, refsym->st_size));
678 break;
681 #if _MIPS_SIM == _ABI64
682 case R_MIPS_64:
683 /* For full compliance with the ELF64 ABI, one must precede the
684 _REL32/_64 pair of relocations with a _64 relocation, such
685 that the in-place addend is read as a 64-bit value. IRIX
686 didn't pick up on this requirement, so we treat the
687 _REL32/_64 relocation as a 64-bit relocation even if it's by
688 itself. For ABI compliance, we ignore such _64 dummy
689 relocations. For RELA, this may be simply removed, since
690 it's totally unnecessary. */
691 if (ELFW(R_SYM) (r_info) == 0)
692 break;
693 /* Fall through. */
694 #endif
695 default:
696 _dl_reloc_bad_type (map, r_type, 0);
697 break;
701 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
702 MAP is the object containing the reloc. */
704 auto inline void
705 __attribute__ ((always_inline))
706 elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
707 const ElfW(Sym) *sym, const struct r_found_version *version,
708 void *const reloc_addr, int skip_ifunc)
710 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1);
713 auto inline void
714 __attribute__((always_inline))
715 elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
716 void *const reloc_addr)
718 /* XXX Nothing to do. There is no relative relocation, right? */
721 auto inline void
722 __attribute__((always_inline))
723 elf_machine_lazy_rel (struct link_map *map,
724 ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
725 int skip_ifunc)
727 ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
728 const unsigned int r_type = ELFW(R_TYPE) (reloc->r_info);
729 /* Check for unexpected PLT reloc type. */
730 if (__builtin_expect (r_type == R_MIPS_JUMP_SLOT, 1))
732 if (__builtin_expect (map->l_mach.plt, 0) == 0)
734 /* Nothing is required here since we only support lazy
735 relocation in executables. */
737 else
738 *reloc_addr = map->l_mach.plt;
740 else
741 _dl_reloc_bad_type (map, r_type, 1);
744 auto inline void
745 __attribute__ ((always_inline))
746 elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
747 const ElfW(Sym) *sym, const struct r_found_version *version,
748 void *const reloc_addr, int skip_ifunc)
750 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr,
751 reloc->r_addend, 0);
754 auto inline void
755 __attribute__((always_inline))
756 elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
757 void *const reloc_addr)
761 #ifndef RTLD_BOOTSTRAP
762 /* Relocate GOT. */
763 auto inline void
764 __attribute__((always_inline))
765 elf_machine_got_rel (struct link_map *map, int lazy)
767 ElfW(Addr) *got;
768 ElfW(Sym) *sym;
769 const ElfW(Half) *vernum;
770 int i, n, symidx;
772 #define RESOLVE_GOTSYM(sym,vernum,sym_index,reloc) \
773 ({ \
774 const ElfW(Sym) *ref = sym; \
775 const struct r_found_version *version __attribute__ ((unused)) \
776 = vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
777 struct link_map *sym_map; \
778 sym_map = RESOLVE_MAP (&ref, version, reloc); \
779 ref ? sym_map->l_addr + ref->st_value : 0; \
782 if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
783 vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
784 else
785 vernum = NULL;
787 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
789 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
790 /* The dynamic linker's local got entries have already been relocated. */
791 if (map != &GL(dl_rtld_map))
793 /* got[0] is reserved. got[1] is also reserved for the dynamic object
794 generated by gnu ld. Skip these reserved entries from relocation. */
795 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
797 /* Add the run-time displacement to all local got entries if
798 needed. */
799 if (__builtin_expect (map->l_addr != 0, 0))
801 while (i < n)
802 got[i++] += map->l_addr;
806 /* Handle global got entries. */
807 got += n;
808 /* Keep track of the symbol index. */
809 symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
810 sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx;
811 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
812 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
814 /* This loop doesn't handle Quickstart. */
815 while (i--)
817 if (sym->st_shndx == SHN_UNDEF)
819 if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC && sym->st_value
820 && !(sym->st_other & STO_MIPS_PLT))
822 if (lazy)
823 *got = sym->st_value + map->l_addr;
824 else
825 /* This is a lazy-binding stub, so we don't need the
826 canonical address. */
827 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
829 else
830 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
832 else if (sym->st_shndx == SHN_COMMON)
833 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
834 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
835 && *got != sym->st_value)
837 if (lazy)
838 *got += map->l_addr;
839 else
840 /* This is a lazy-binding stub, so we don't need the
841 canonical address. */
842 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
844 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
846 if (sym->st_other == 0)
847 *got += map->l_addr;
849 else
850 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
852 ++got;
853 ++sym;
854 ++symidx;
857 #undef RESOLVE_GOTSYM
859 #endif
861 /* Set up the loaded object described by L so its stub function
862 will jump to the on-demand fixup code __dl_runtime_resolve. */
864 auto inline int
865 __attribute__((always_inline))
866 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
868 # ifndef RTLD_BOOTSTRAP
869 ElfW(Addr) *got;
870 extern void _dl_runtime_resolve (ElfW(Word));
871 extern void _dl_runtime_pltresolve (void);
872 extern int _dl_mips_gnu_objects;
874 if (lazy)
876 /* The GOT entries for functions have not yet been filled in.
877 Their initial contents will arrange when called to put an
878 offset into the .dynsym section in t8, the return address
879 in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
880 got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
882 /* This function will get called to fix up the GOT entry indicated by
883 the register t8, and then jump to the resolved address. */
884 got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
886 /* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
887 of got[1] of a gnu object is set to identify gnu objects.
888 Where we can store l for non gnu objects? XXX */
889 if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
890 got[1] = ((ElfW(Addr)) l | ELF_MIPS_GNU_GOT1_MASK);
891 else
892 _dl_mips_gnu_objects = 0;
895 /* Relocate global offset table. */
896 elf_machine_got_rel (l, lazy);
898 /* If using PLTs, fill in the first two entries of .got.plt. */
899 if (l->l_info[DT_JMPREL] && lazy)
901 ElfW(Addr) *gotplt;
902 gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_MIPS (PLTGOT)]);
903 /* If a library is prelinked but we have to relocate anyway,
904 we have to be able to undo the prelinking of .got.plt.
905 The prelinker saved the address of .plt for us here. */
906 if (gotplt[1])
907 l->l_mach.plt = gotplt[1] + l->l_addr;
908 gotplt[0] = (ElfW(Addr)) &_dl_runtime_pltresolve;
909 gotplt[1] = (ElfW(Addr)) l;
912 # endif
913 return lazy;
916 #endif /* RESOLVE_MAP */