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Add dl-procinfo support for MIPS.
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1 /* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
2 Copyright (C) 1996-2012 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>.
5
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.
10
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.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
20
21 /* FIXME: Profiling of shared libraries is not implemented yet. */
22 #ifndef dl_machine_h
23 #define dl_machine_h
24
25 #define ELF_MACHINE_NAME "MIPS"
26
27 #include <entry.h>
28
29 #ifndef ENTRY_POINT
30 #error ENTRY_POINT needs to be defined for MIPS.
31 #endif
32
33 #include <sgidefs.h>
34 #include <sys/asm.h>
35 #include <dl-tls.h>
36
37 /* The offset of gp from GOT might be system-dependent. It's set by
38 ld. The same value is also */
39 #define OFFSET_GP_GOT 0x7ff0
40
41 #ifndef _RTLD_PROLOGUE
42 # define _RTLD_PROLOGUE(entry) \
43 ".globl\t" __STRING(entry) "\n\t" \
44 ".ent\t" __STRING(entry) "\n\t" \
45 ".type\t" __STRING(entry) ", @function\n" \
46 __STRING(entry) ":\n\t"
47 #endif
48
49 #ifndef _RTLD_EPILOGUE
50 # define _RTLD_EPILOGUE(entry) \
51 ".end\t" __STRING(entry) "\n\t" \
52 ".size\t" __STRING(entry) ", . - " __STRING(entry) "\n\t"
53 #endif
54
55 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
56 This only makes sense on MIPS when using PLTs, so choose the
57 PLT relocation (not encountered when not using PLTs). */
58 #define ELF_MACHINE_JMP_SLOT R_MIPS_JUMP_SLOT
59 #define elf_machine_type_class(type) \
60 ((((type) == ELF_MACHINE_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
61 | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
62
63 #define ELF_MACHINE_PLT_REL 1
64
65 /* Translate a processor specific dynamic tag to the index
66 in l_info array. */
67 #define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
68
69 /* If there is a DT_MIPS_RLD_MAP entry in the dynamic section, fill it in
70 with the run-time address of the r_debug structure */
71 #define ELF_MACHINE_DEBUG_SETUP(l,r) \
72 do { if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
73 *(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
74 (ElfW(Addr)) (r); \
75 } while (0)
76
77 /* Return nonzero iff ELF header is compatible with the running host. */
78 static inline int __attribute_used__
79 elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
80 {
81 #if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32
82 /* Don't link o32 and n32 together. */
83 if (((ehdr->e_flags & EF_MIPS_ABI2) != 0) != (_MIPS_SIM == _ABIN32))
84 return 0;
85 #endif
86
87 switch (ehdr->e_machine)
88 {
89 case EM_MIPS:
90 case EM_MIPS_RS3_LE:
91 return 1;
92 default:
93 return 0;
94 }
95 }
96
97 static inline ElfW(Addr) *
98 elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
99 {
100 /* FIXME: the offset of gp from GOT may be system-dependent. */
101 return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
102 }
103
104 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
105 first element of the GOT. This must be inlined in a function which
106 uses global data. We assume its $gp points to the primary GOT. */
107 static inline ElfW(Addr)
108 elf_machine_dynamic (void)
109 {
110 register ElfW(Addr) gp __asm__ ("$28");
111 return *elf_mips_got_from_gpreg (gp);
112 }
113
114 #define STRINGXP(X) __STRING(X)
115 #define STRINGXV(X) STRINGV_(X)
116 #define STRINGV_(...) # __VA_ARGS__
117
118 /* Return the run-time load address of the shared object. */
119 static inline ElfW(Addr)
120 elf_machine_load_address (void)
121 {
122 ElfW(Addr) addr;
123 asm (" .set noreorder\n"
124 " " STRINGXP (PTR_LA) " %0, 0f\n"
125 " bltzal $0, 0f\n"
126 " nop\n"
127 "0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
128 " .set reorder\n"
129 : "=r" (addr)
130 : /* No inputs */
131 : "$31");
132 return addr;
133 }
134
135 /* The MSB of got[1] of a gnu object is set to identify gnu objects. */
136 #if _MIPS_SIM == _ABI64
137 # define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L
138 #else
139 # define ELF_MIPS_GNU_GOT1_MASK 0x80000000L
140 #endif
141
142 /* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope
143 fiddles with global data. */
144 #define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
145 do { \
146 struct link_map *map = &bootstrap_map; \
147 ElfW(Sym) *sym; \
148 ElfW(Addr) *got; \
149 int i, n; \
150 \
151 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \
152 \
153 if (__builtin_expect (map->l_addr == 0, 1)) \
154 break; \
155 \
156 /* got[0] is reserved. got[1] is also reserved for the dynamic object \
157 generated by gnu ld. Skip these reserved entries from \
158 relocation. */ \
159 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
160 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
161 \
162 /* Add the run-time displacement to all local got entries. */ \
163 while (i < n) \
164 got[i++] += map->l_addr; \
165 \
166 /* Handle global got entries. */ \
167 got += n; \
168 sym = (ElfW(Sym) *) D_PTR(map, l_info[DT_SYMTAB]) \
169 + map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
170 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val \
171 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); \
172 \
173 while (i--) \
174 { \
175 if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_COMMON) \
176 *got = map->l_addr + sym->st_value; \
177 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \
178 && *got != sym->st_value) \
179 *got += map->l_addr; \
180 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION) \
181 { \
182 if (sym->st_other == 0) \
183 *got += map->l_addr; \
184 } \
185 else \
186 *got = map->l_addr + sym->st_value; \
187 \
188 got++; \
189 sym++; \
190 } \
191 } while(0)
192
193
194 /* Mask identifying addresses reserved for the user program,
195 where the dynamic linker should not map anything. */
196 #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
197
198
199 /* Initial entry point code for the dynamic linker.
200 The C function `_dl_start' is the real entry point;
201 its return value is the user program's entry point.
202 Note how we have to be careful about two things:
203
204 1) That we allocate a minimal stack of 24 bytes for
205 every function call, the MIPS ABI states that even
206 if all arguments are passed in registers the procedure
207 called can use the 16 byte area pointed to by $sp
208 when it is called to store away the arguments passed
209 to it.
210
211 2) That under Linux the entry is named __start
212 and not just plain _start. */
213
214 #define RTLD_START asm (\
215 ".text\n\
216 " _RTLD_PROLOGUE(ENTRY_POINT) "\
217 " STRINGXV(SETUP_GPX($25)) "\n\
218 " STRINGXV(SETUP_GPX64($18,$25)) "\n\
219 # i386 ABI book says that the first entry of GOT holds\n\
220 # the address of the dynamic structure. Though MIPS ABI\n\
221 # doesn't say nothing about this, I emulate this here.\n\
222 " STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
223 # Subtract OFFSET_GP_GOT\n\
224 " STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
225 move $4, $29\n\
226 " STRINGXP(PTR_SUBIU) " $29, 16\n\
227 \n\
228 " STRINGXP(PTR_LA) " $8, .Lcoff\n\
229 bltzal $8, .Lcoff\n\
230 .Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
231 \n\
232 " STRINGXP(PTR_LA) " $25, _dl_start\n\
233 " STRINGXP(PTR_ADDU) " $25, $8\n\
234 jalr $25\n\
235 \n\
236 " STRINGXP(PTR_ADDIU) " $29, 16\n\
237 # Get the value of label '_dl_start_user' in t9 ($25).\n\
238 " STRINGXP(PTR_LA) " $25, _dl_start_user\n\
239 " _RTLD_EPILOGUE(ENTRY_POINT) "\
240 \n\
241 \n\
242 " _RTLD_PROLOGUE(_dl_start_user) "\
243 " STRINGXP(SETUP_GP) "\n\
244 " STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
245 move $16, $28\n\
246 # Save the user entry point address in a saved register.\n\
247 move $17, $2\n\
248 # See if we were run as a command with the executable file\n\
249 # name as an extra leading argument.\n\
250 lw $2, _dl_skip_args\n\
251 beq $2, $0, 1f\n\
252 # Load the original argument count.\n\
253 " STRINGXP(PTR_L) " $4, 0($29)\n\
254 # Subtract _dl_skip_args from it.\n\
255 subu $4, $2\n\
256 # Adjust the stack pointer to skip _dl_skip_args words.\n\
257 sll $2, " STRINGXP (PTRLOG) "\n\
258 " STRINGXP(PTR_ADDU) " $29, $2\n\
259 # Save back the modified argument count.\n\
260 " STRINGXP(PTR_S) " $4, 0($29)\n\
261 1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
262 " STRINGXP(PTR_L) " $4, _rtld_local\n\
263 " STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
264 " STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
265 sll $7, $5, " STRINGXP (PTRLOG) "\n\
266 " STRINGXP(PTR_ADDU) " $7, $7, $6\n\
267 " STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
268 # Make sure the stack pointer is aligned for _dl_init_internal.\n\
269 and $2, $29, -2 * " STRINGXP(SZREG) "\n\
270 " STRINGXP(PTR_S) " $29, -" STRINGXP(SZREG) "($2)\n\
271 " STRINGXP(PTR_SUBIU) " $29, $2, 32\n\
272 " STRINGXP(SAVE_GP(16)) "\n\
273 # Call the function to run the initializers.\n\
274 jal _dl_init_internal\n\
275 # Restore the stack pointer for _start.\n\
276 " STRINGXP(PTR_L) " $29, 32-" STRINGXP(SZREG) "($29)\n\
277 # Pass our finalizer function to the user in $2 as per ELF ABI.\n\
278 " STRINGXP(PTR_LA) " $2, _dl_fini\n\
279 # Jump to the user entry point.\n\
280 move $25, $17\n\
281 jr $25\n\t"\
282 _RTLD_EPILOGUE(_dl_start_user)\
283 ".previous"\
284 );
285
286 /* Names of the architecture-specific auditing callback functions. */
287 # if _MIPS_SIM == _ABIO32
288 # define ARCH_LA_PLTENTER mips_o32_gnu_pltenter
289 # define ARCH_LA_PLTEXIT mips_o32_gnu_pltexit
290 # elif _MIPS_SIM == _ABIN32
291 # define ARCH_LA_PLTENTER mips_n32_gnu_pltenter
292 # define ARCH_LA_PLTEXIT mips_n32_gnu_pltexit
293 # else
294 # define ARCH_LA_PLTENTER mips_n64_gnu_pltenter
295 # define ARCH_LA_PLTEXIT mips_n64_gnu_pltexit
296 # endif
297
298 /* We define an initialization function. This is called very early in
299 _dl_sysdep_start. */
300 #define DL_PLATFORM_INIT dl_platform_init ()
301
302 static inline void __attribute__ ((unused))
303 dl_platform_init (void)
304 {
305 if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
306 /* Avoid an empty string which would disturb us. */
307 GLRO(dl_platform) = NULL;
308 }
309
310 /* For a non-writable PLT, rewrite the .got.plt entry at RELOC_ADDR to
311 point at the symbol with address VALUE. For a writable PLT, rewrite
312 the corresponding PLT entry instead. */
313 static inline ElfW(Addr)
314 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
315 const ElfW(Rel) *reloc,
316 ElfW(Addr) *reloc_addr, ElfW(Addr) value)
317 {
318 return *reloc_addr = value;
319 }
320
321 static inline ElfW(Addr)
322 elf_machine_plt_value (struct link_map *map, const ElfW(Rel) *reloc,
323 ElfW(Addr) value)
324 {
325 return value;
326 }
327
328 #endif /* !dl_machine_h */
329
330 #ifdef RESOLVE_MAP
331
332 /* Perform a relocation described by R_INFO at the location pointed to
333 by RELOC_ADDR. SYM is the relocation symbol specified by R_INFO and
334 MAP is the object containing the reloc. */
335
336 auto inline void
337 __attribute__ ((always_inline))
338 elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
339 const ElfW(Sym) *sym, const struct r_found_version *version,
340 void *reloc_addr, ElfW(Addr) r_addend, int inplace_p)
341 {
342 const unsigned long int r_type = ELFW(R_TYPE) (r_info);
343 ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;
344
345 #if !defined RTLD_BOOTSTRAP && !defined SHARED
346 /* This is defined in rtld.c, but nowhere in the static libc.a;
347 make the reference weak so static programs can still link. This
348 declaration cannot be done when compiling rtld.c (i.e. #ifdef
349 RTLD_BOOTSTRAP) because rtld.c contains the common defn for
350 _dl_rtld_map, which is incompatible with a weak decl in the same
351 file. */
352 weak_extern (GL(dl_rtld_map));
353 #endif
354
355 switch (r_type)
356 {
357 #if !defined (RTLD_BOOTSTRAP)
358 # if _MIPS_SIM == _ABI64
359 case R_MIPS_TLS_DTPMOD64:
360 case R_MIPS_TLS_DTPREL64:
361 case R_MIPS_TLS_TPREL64:
362 # else
363 case R_MIPS_TLS_DTPMOD32:
364 case R_MIPS_TLS_DTPREL32:
365 case R_MIPS_TLS_TPREL32:
366 # endif
367 {
368 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
369
370 switch (r_type)
371 {
372 case R_MIPS_TLS_DTPMOD64:
373 case R_MIPS_TLS_DTPMOD32:
374 if (sym_map)
375 *addr_field = sym_map->l_tls_modid;
376 break;
377
378 case R_MIPS_TLS_DTPREL64:
379 case R_MIPS_TLS_DTPREL32:
380 if (sym)
381 {
382 if (inplace_p)
383 r_addend = *addr_field;
384 *addr_field = r_addend + TLS_DTPREL_VALUE (sym);
385 }
386 break;
387
388 case R_MIPS_TLS_TPREL32:
389 case R_MIPS_TLS_TPREL64:
390 if (sym)
391 {
392 CHECK_STATIC_TLS (map, sym_map);
393 if (inplace_p)
394 r_addend = *addr_field;
395 *addr_field = r_addend + TLS_TPREL_VALUE (sym_map, sym);
396 }
397 break;
398 }
399
400 break;
401 }
402 #endif
403
404 #if _MIPS_SIM == _ABI64
405 case (R_MIPS_64 << 8) | R_MIPS_REL32:
406 #else
407 case R_MIPS_REL32:
408 #endif
409 {
410 int symidx = ELFW(R_SYM) (r_info);
411 ElfW(Addr) reloc_value;
412
413 if (inplace_p)
414 /* Support relocations on mis-aligned offsets. */
415 __builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
416 else
417 reloc_value = r_addend;
418
419 if (symidx)
420 {
421 const ElfW(Word) gotsym
422 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
423
424 if ((ElfW(Word))symidx < gotsym)
425 {
426 /* This wouldn't work for a symbol imported from other
427 libraries for which there's no GOT entry, but MIPS
428 requires every symbol referenced in a dynamic
429 relocation to have a GOT entry in the primary GOT,
430 so we only get here for locally-defined symbols.
431 For section symbols, we should *NOT* be adding
432 sym->st_value (per the definition of the meaning of
433 S in reloc expressions in the ELF64 MIPS ABI),
434 since it should have already been added to
435 reloc_value by the linker, but older versions of
436 GNU ld didn't add it, and newer versions don't emit
437 useless relocations to section symbols any more, so
438 it is safe to keep on adding sym->st_value, even
439 though it's not ABI compliant. Some day we should
440 bite the bullet and stop doing this. */
441 #ifndef RTLD_BOOTSTRAP
442 if (map != &GL(dl_rtld_map))
443 #endif
444 reloc_value += sym->st_value + map->l_addr;
445 }
446 else
447 {
448 #ifndef RTLD_BOOTSTRAP
449 const ElfW(Addr) *got
450 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
451 const ElfW(Word) local_gotno
452 = (const ElfW(Word))
453 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
454
455 reloc_value += got[symidx + local_gotno - gotsym];
456 #endif
457 }
458 }
459 else
460 #ifndef RTLD_BOOTSTRAP
461 if (map != &GL(dl_rtld_map))
462 #endif
463 reloc_value += map->l_addr;
464
465 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
466 }
467 break;
468 #ifndef RTLD_BOOTSTRAP
469 #if _MIPS_SIM == _ABI64
470 case (R_MIPS_64 << 8) | R_MIPS_GLOB_DAT:
471 #else
472 case R_MIPS_GLOB_DAT:
473 #endif
474 {
475 int symidx = ELFW(R_SYM) (r_info);
476 const ElfW(Word) gotsym
477 = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
478
479 if (__builtin_expect ((ElfW(Word)) symidx >= gotsym, 1))
480 {
481 const ElfW(Addr) *got
482 = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
483 const ElfW(Word) local_gotno
484 = ((const ElfW(Word))
485 map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val);
486
487 ElfW(Addr) reloc_value = got[symidx + local_gotno - gotsym];
488 __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
489 }
490 }
491 break;
492 #endif
493 case R_MIPS_NONE: /* Alright, Wilbur. */
494 break;
495
496 case R_MIPS_JUMP_SLOT:
497 {
498 struct link_map *sym_map;
499 ElfW(Addr) value;
500
501 /* The addend for a jump slot relocation must always be zero:
502 calls via the PLT always branch to the symbol's address and
503 not to the address plus a non-zero offset. */
504 if (r_addend != 0)
505 _dl_signal_error (0, map->l_name, NULL,
506 "found jump slot relocation with non-zero addend");
507
508 sym_map = RESOLVE_MAP (&sym, version, r_type);
509 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
510 *addr_field = value;
511
512 break;
513 }
514
515 case R_MIPS_COPY:
516 {
517 const ElfW(Sym) *const refsym = sym;
518 struct link_map *sym_map;
519 ElfW(Addr) value;
520
521 /* Calculate the address of the symbol. */
522 sym_map = RESOLVE_MAP (&sym, version, r_type);
523 value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
524
525 if (__builtin_expect (sym == NULL, 0))
526 /* This can happen in trace mode if an object could not be
527 found. */
528 break;
529 if (__builtin_expect (sym->st_size > refsym->st_size, 0)
530 || (__builtin_expect (sym->st_size < refsym->st_size, 0)
531 && GLRO(dl_verbose)))
532 {
533 const char *strtab;
534
535 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
536 _dl_error_printf ("\
537 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
538 rtld_progname ?: "<program name unknown>",
539 strtab + refsym->st_name);
540 }
541 memcpy (reloc_addr, (void *) value,
542 MIN (sym->st_size, refsym->st_size));
543 break;
544 }
545
546 #if _MIPS_SIM == _ABI64
547 case R_MIPS_64:
548 /* For full compliance with the ELF64 ABI, one must precede the
549 _REL32/_64 pair of relocations with a _64 relocation, such
550 that the in-place addend is read as a 64-bit value. IRIX
551 didn't pick up on this requirement, so we treat the
552 _REL32/_64 relocation as a 64-bit relocation even if it's by
553 itself. For ABI compliance, we ignore such _64 dummy
554 relocations. For RELA, this may be simply removed, since
555 it's totally unnecessary. */
556 if (ELFW(R_SYM) (r_info) == 0)
557 break;
558 /* Fall through. */
559 #endif
560 default:
561 _dl_reloc_bad_type (map, r_type, 0);
562 break;
563 }
564 }
565
566 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
567 MAP is the object containing the reloc. */
568
569 auto inline void
570 __attribute__ ((always_inline))
571 elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
572 const ElfW(Sym) *sym, const struct r_found_version *version,
573 void *const reloc_addr, int skip_ifunc)
574 {
575 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1);
576 }
577
578 auto inline void
579 __attribute__((always_inline))
580 elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
581 void *const reloc_addr)
582 {
583 /* XXX Nothing to do. There is no relative relocation, right? */
584 }
585
586 auto inline void
587 __attribute__((always_inline))
588 elf_machine_lazy_rel (struct link_map *map,
589 ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
590 int skip_ifunc)
591 {
592 ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
593 const unsigned int r_type = ELFW(R_TYPE) (reloc->r_info);
594 /* Check for unexpected PLT reloc type. */
595 if (__builtin_expect (r_type == R_MIPS_JUMP_SLOT, 1))
596 {
597 if (__builtin_expect (map->l_mach.plt, 0) == 0)
598 {
599 /* Nothing is required here since we only support lazy
600 relocation in executables. */
601 }
602 else
603 *reloc_addr = map->l_mach.plt;
604 }
605 else
606 _dl_reloc_bad_type (map, r_type, 1);
607 }
608
609 auto inline void
610 __attribute__ ((always_inline))
611 elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
612 const ElfW(Sym) *sym, const struct r_found_version *version,
613 void *const reloc_addr, int skip_ifunc)
614 {
615 elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr,
616 reloc->r_addend, 0);
617 }
618
619 auto inline void
620 __attribute__((always_inline))
621 elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
622 void *const reloc_addr)
623 {
624 }
625
626 #ifndef RTLD_BOOTSTRAP
627 /* Relocate GOT. */
628 auto inline void
629 __attribute__((always_inline))
630 elf_machine_got_rel (struct link_map *map, int lazy)
631 {
632 ElfW(Addr) *got;
633 ElfW(Sym) *sym;
634 const ElfW(Half) *vernum;
635 int i, n, symidx;
636
637 #define RESOLVE_GOTSYM(sym,vernum,sym_index,reloc) \
638 ({ \
639 const ElfW(Sym) *ref = sym; \
640 const struct r_found_version *version \
641 = vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
642 struct link_map *sym_map; \
643 sym_map = RESOLVE_MAP (&ref, version, reloc); \
644 ref ? sym_map->l_addr + ref->st_value : 0; \
645 })
646
647 if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
648 vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
649 else
650 vernum = NULL;
651
652 got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
653
654 n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
655 /* The dynamic linker's local got entries have already been relocated. */
656 if (map != &GL(dl_rtld_map))
657 {
658 /* got[0] is reserved. got[1] is also reserved for the dynamic object
659 generated by gnu ld. Skip these reserved entries from relocation. */
660 i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
661
662 /* Add the run-time displacement to all local got entries if
663 needed. */
664 if (__builtin_expect (map->l_addr != 0, 0))
665 {
666 while (i < n)
667 got[i++] += map->l_addr;
668 }
669 }
670
671 /* Handle global got entries. */
672 got += n;
673 /* Keep track of the symbol index. */
674 symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
675 sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx;
676 i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
677 - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
678
679 /* This loop doesn't handle Quickstart. */
680 while (i--)
681 {
682 if (sym->st_shndx == SHN_UNDEF)
683 {
684 if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC && sym->st_value
685 && !(sym->st_other & STO_MIPS_PLT))
686 {
687 if (lazy)
688 *got = sym->st_value + map->l_addr;
689 else
690 /* This is a lazy-binding stub, so we don't need the
691 canonical address. */
692 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
693 }
694 else
695 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
696 }
697 else if (sym->st_shndx == SHN_COMMON)
698 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
699 else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
700 && *got != sym->st_value)
701 {
702 if (lazy)
703 *got += map->l_addr;
704 else
705 /* This is a lazy-binding stub, so we don't need the
706 canonical address. */
707 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
708 }
709 else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
710 {
711 if (sym->st_other == 0)
712 *got += map->l_addr;
713 }
714 else
715 *got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
716
717 ++got;
718 ++sym;
719 ++symidx;
720 }
721
722 #undef RESOLVE_GOTSYM
723 }
724 #endif
725
726 /* Set up the loaded object described by L so its stub function
727 will jump to the on-demand fixup code __dl_runtime_resolve. */
728
729 auto inline int
730 __attribute__((always_inline))
731 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
732 {
733 # ifndef RTLD_BOOTSTRAP
734 ElfW(Addr) *got;
735 extern void _dl_runtime_resolve (ElfW(Word));
736 extern void _dl_runtime_pltresolve (void);
737 extern int _dl_mips_gnu_objects;
738
739 if (lazy)
740 {
741 /* The GOT entries for functions have not yet been filled in.
742 Their initial contents will arrange when called to put an
743 offset into the .dynsym section in t8, the return address
744 in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
745 got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
746
747 /* This function will get called to fix up the GOT entry indicated by
748 the register t8, and then jump to the resolved address. */
749 got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
750
751 /* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
752 of got[1] of a gnu object is set to identify gnu objects.
753 Where we can store l for non gnu objects? XXX */
754 if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
755 got[1] = ((ElfW(Addr)) l | ELF_MIPS_GNU_GOT1_MASK);
756 else
757 _dl_mips_gnu_objects = 0;
758 }
759
760 /* Relocate global offset table. */
761 elf_machine_got_rel (l, lazy);
762
763 /* If using PLTs, fill in the first two entries of .got.plt. */
764 if (l->l_info[DT_JMPREL] && lazy)
765 {
766 ElfW(Addr) *gotplt;
767 gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_MIPS (PLTGOT)]);
768 /* If a library is prelinked but we have to relocate anyway,
769 we have to be able to undo the prelinking of .got.plt.
770 The prelinker saved the address of .plt for us here. */
771 if (gotplt[1])
772 l->l_mach.plt = gotplt[1] + l->l_addr;
773 gotplt[0] = (ElfW(Addr)) &_dl_runtime_pltresolve;
774 gotplt[1] = (ElfW(Addr)) l;
775 }
776
777 # endif
778 return lazy;
779 }
780
781 #endif /* RESOLVE_MAP */