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1 /* Machine-dependent ELF dynamic relocation inline functions. SPARC version.
2 Copyright (C) 1996-2019 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
22 #define ELF_MACHINE_NAME "sparc"
25 #include <sys/param.h>
30 #include <elf/dl-hwcaps.h>
32 /* Return nonzero iff ELF header is compatible with the running host. */
34 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
36 if (ehdr
->e_machine
== EM_SPARC
)
38 else if (ehdr
->e_machine
== EM_SPARC32PLUS
)
40 #if HAVE_TUNABLES || defined SHARED
41 uint64_t hwcap_mask
= GET_HWCAP_MASK();
42 return GLRO(dl_hwcap
) & hwcap_mask
& HWCAP_SPARC_V9
;
44 return GLRO(dl_hwcap
) & HWCAP_SPARC_V9
;
51 /* We have to do this because elf_machine_{dynamic,load_address} can be
52 invoked from functions that have no GOT references, and thus the compiler
53 has no obligation to load the PIC register. */
54 #define LOAD_PIC_REG(PIC_REG) \
55 do { register Elf32_Addr pc __asm("o7"); \
56 __asm("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t" \
58 "add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n" \
59 "1:\tadd %1, %0, %1" \
60 : "=r" (pc), "=r" (PIC_REG)); \
63 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
64 first element of the GOT. This must be inlined in a function which
66 static inline Elf32_Addr
67 elf_machine_dynamic (void)
69 register Elf32_Addr
*got
asm ("%l7");
76 /* Return the run-time load address of the shared object. */
77 static inline Elf32_Addr
78 elf_machine_load_address (void)
80 register Elf32_Addr
*pc
__asm ("%o7"), *got
__asm ("%l7");
82 __asm ("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t"
84 " add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n\t"
86 "call _GLOBAL_OFFSET_TABLE_\n"
87 "1:\tadd %1, %0, %1\n\t" : "=r" (pc
), "=r" (got
));
89 /* got is now l_addr + _GLOBAL_OFFSET_TABLE_
91 pc[2]*4 is l_addr + _DYNAMIC - (long)pc - 8
92 pc[3]*4 is l_addr + _GLOBAL_OFFSET_TABLE_ - (long)pc - 12 */
93 return (Elf32_Addr
) got
- *got
+ (pc
[2] - pc
[3]) * 4 - 4;
96 /* Set up the loaded object described by L so its unrelocated PLT
97 entries will jump to the on-demand fixup code in dl-runtime.c. */
100 elf_machine_runtime_setup (struct link_map
*l
, int lazy
, int profile
)
103 extern void _dl_runtime_resolve (Elf32_Word
);
104 extern void _dl_runtime_profile (Elf32_Word
);
106 if (l
->l_info
[DT_JMPREL
] && lazy
)
110 /* The entries for functions in the PLT have not yet been filled in.
111 Their initial contents will arrange when called to set the high 22
112 bits of %g1 with an offset into the .rela.plt section and jump to
113 the beginning of the PLT. */
114 plt
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
115 if (__builtin_expect(profile
, 0))
117 rfunc
= (Elf32_Addr
) &_dl_runtime_profile
;
119 if (GLRO(dl_profile
) != NULL
120 && _dl_name_match_p (GLRO(dl_profile
), l
))
121 GL(dl_profile_map
) = l
;
125 rfunc
= (Elf32_Addr
) &_dl_runtime_resolve
;
128 /* The beginning of the PLT does:
130 sethi %hi(_dl_runtime_{resolve,profile}), %g2
131 pltpc: jmpl %g2 + %lo(_dl_runtime_{resolve,profile}), %g2
135 The PC value (pltpc) saved in %g2 by the jmpl points near the
136 location where we store the link_map pointer for this object. */
138 plt
[0] = 0x05000000 | ((rfunc
>> 10) & 0x003fffff);
139 plt
[1] = 0x85c0a000 | (rfunc
& 0x3ff);
140 plt
[2] = OPCODE_NOP
; /* Fill call delay slot. */
141 plt
[3] = (Elf32_Addr
) l
;
142 if (__builtin_expect (l
->l_info
[VALIDX(DT_GNU_PRELINKED
)] != NULL
, 0)
143 || __builtin_expect (l
->l_info
[VALIDX (DT_GNU_LIBLISTSZ
)] != NULL
, 0))
145 /* Need to reinitialize .plt to undo prelinking. */
146 Elf32_Rela
*rela
= (Elf32_Rela
*) D_PTR (l
, l_info
[DT_JMPREL
]);
148 = (Elf32_Rela
*) ((char *) rela
149 + l
->l_info
[DT_PLTRELSZ
]->d_un
.d_val
);
150 #if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
151 /* Note that we don't mask the hwcap here, as the flush is
152 essential to functionality on those cpu's that implement it.
153 For sparcv9 we can assume flush is present. */
154 const int do_flush
= GLRO(dl_hwcap
) & HWCAP_SPARC_FLUSH
;
156 const int do_flush
= 1;
159 /* prelink must ensure there are no R_SPARC_NONE relocs left
161 while (rela
< relaend
)
163 *(unsigned int *) (rela
->r_offset
+ l
->l_addr
)
164 = OPCODE_SETHI_G1
| (rela
->r_offset
+ l
->l_addr
166 *(unsigned int *) (rela
->r_offset
+ l
->l_addr
+ 4)
167 = OPCODE_BA
| ((((Elf32_Addr
) plt
168 - rela
->r_offset
- l
->l_addr
- 4) >> 2)
172 __asm
__volatile ("flush %0" : : "r" (rela
->r_offset
174 __asm
__volatile ("flush %0+4" : : "r" (rela
->r_offset
185 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
186 PLT entries should not be allowed to define the value.
187 ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
188 of the main executable's symbols, as for a COPY reloc. */
189 #define elf_machine_type_class(type) \
190 ((((type) == R_SPARC_JMP_SLOT \
191 || ((type) >= R_SPARC_TLS_GD_HI22 && (type) <= R_SPARC_TLS_TPOFF64)) \
192 * ELF_RTYPE_CLASS_PLT) \
193 | (((type) == R_SPARC_COPY) * ELF_RTYPE_CLASS_COPY))
195 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
196 #define ELF_MACHINE_JMP_SLOT R_SPARC_JMP_SLOT
198 /* The SPARC never uses Elf32_Rel relocations. */
199 #define ELF_MACHINE_NO_REL 1
200 #define ELF_MACHINE_NO_RELA 0
202 /* Undo the sub %sp, 6*4, %sp; add %sp, 22*4, %o0 below to get at the
203 value we want in __libc_stack_end. */
204 #define DL_STACK_END(cookie) \
205 ((void *) (((long) (cookie)) - (22 - 6) * 4))
207 /* Initial entry point code for the dynamic linker.
208 The C function `_dl_start' is the real entry point;
209 its return value is the user program's entry point. */
211 #define RTLD_GOT_ADDRESS(pic_reg, reg, symbol) \
212 "sethi %gdop_hix22(" #symbol "), " #reg "\n\t" \
213 "xor " #reg ", %gdop_lox10(" #symbol "), " #reg "\n\t" \
214 "ld [" #pic_reg " + " #reg "], " #reg ", %gdop(" #symbol ")"
216 #define RTLD_START __asm__ ("\
219 .type _start, @function\n\
222 /* Allocate space for functions to drop their arguments. */\n\
224 /* Pass pointer to argument block to _dl_start. */\n\
226 add %sp, 22*4, %o0\n\
228 .globl _dl_start_user\n\
229 .type _dl_start_user, @function\n\
231 /* Load the PIC register. */\n\
233 sethi %hi(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
234 2: or %l7, %lo(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
236 /* Save the user entry point address in %l0 */\n\
238 /* See if we were run as a command with the executable file name as an\n\
239 extra leading argument. If so, adjust the contents of the stack. */\n\
240 " RTLD_GOT_ADDRESS(%l7, %g2, _dl_skip_args) "\n\
244 ld [%sp+22*4], %i5 /* load argc */\n\
245 /* Find out how far to shift. */\n\
246 " RTLD_GOT_ADDRESS(%l7, %l3, _dl_argv) "\n\
250 st %i5, [%sp+22*4]\n\
252 add %sp, 23*4, %i1\n\
255 /* Copy down argv */\n\
262 /* Copy down env */\n\
269 /* Copy down auxiliary table. */\n\
278 /* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp. */\n\
279 3: " RTLD_GOT_ADDRESS(%l7, %o0, _rtld_local) "\n\
280 add %sp, 23*4, %o2\n\
287 /* Pass our finalizer function to the user in %g1. */\n\
288 " RTLD_GOT_ADDRESS(%l7, %g1, _dl_fini) "\n\
289 /* Jump to the user's entry point and deallocate the extra stack we got. */\n\
292 .size _dl_start_user, . - _dl_start_user\n\
295 static inline Elf32_Addr
296 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
297 const ElfW(Sym
) *refsym
, const ElfW(Sym
) *sym
,
298 const Elf32_Rela
*reloc
,
299 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
302 /* Sparc v9 can assume flush is always present. */
303 const int do_flush
= 1;
305 /* Note that we don't mask the hwcap here, as the flush is essential to
306 functionality on those cpu's that implement it. */
307 const int do_flush
= GLRO(dl_hwcap
) & HWCAP_SPARC_FLUSH
;
309 return sparc_fixup_plt (reloc
, reloc_addr
, value
, 1, do_flush
);
312 /* Return the final value of a plt relocation. */
313 static inline Elf32_Addr
314 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
317 return value
+ reloc
->r_addend
;
320 #endif /* dl_machine_h */
322 #define ARCH_LA_PLTENTER sparc32_gnu_pltenter
323 #define ARCH_LA_PLTEXIT sparc32_gnu_pltexit
327 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
328 MAP is the object containing the reloc. */
331 __attribute__ ((always_inline
))
332 elf_machine_rela (struct link_map
*map
, const Elf32_Rela
*reloc
,
333 const Elf32_Sym
*sym
, const struct r_found_version
*version
,
334 void *const reloc_addr_arg
, int skip_ifunc
)
336 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
337 #if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
338 const Elf32_Sym
*const refsym
= sym
;
341 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
342 #if !defined RESOLVE_CONFLICT_FIND_MAP
343 struct link_map
*sym_map
= NULL
;
346 #if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
347 /* This is defined in rtld.c, but nowhere in the static libc.a; make the
348 reference weak so static programs can still link. This declaration
349 cannot be done when compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP)
350 because rtld.c contains the common defn for _dl_rtld_map, which is
351 incompatible with a weak decl in the same file. */
352 weak_extern (_dl_rtld_map
);
355 if (__glibc_unlikely (r_type
== R_SPARC_NONE
))
358 if (__glibc_unlikely (r_type
== R_SPARC_SIZE32
))
360 *reloc_addr
= sym
->st_size
+ reloc
->r_addend
;
364 #if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
365 if (__glibc_unlikely (r_type
== R_SPARC_RELATIVE
))
367 # if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
368 if (map
!= &_dl_rtld_map
) /* Already done in rtld itself. */
370 *reloc_addr
+= map
->l_addr
+ reloc
->r_addend
;
375 #ifndef RESOLVE_CONFLICT_FIND_MAP
376 if (__builtin_expect (ELF32_ST_BIND (sym
->st_info
) == STB_LOCAL
, 0)
377 && sym
->st_shndx
!= SHN_UNDEF
)
384 sym_map
= RESOLVE_MAP (&sym
, version
, r_type
);
385 value
= SYMBOL_ADDRESS (sym_map
, sym
, true);
391 value
+= reloc
->r_addend
; /* Assume copy relocs have zero addend. */
394 && __builtin_expect (ELFW(ST_TYPE
) (sym
->st_info
) == STT_GNU_IFUNC
, 0)
395 && __builtin_expect (sym
->st_shndx
!= SHN_UNDEF
, 1)
396 && __builtin_expect (!skip_ifunc
, 1))
398 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
403 #if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
406 /* This can happen in trace mode if an object could not be
409 if (sym
->st_size
> refsym
->st_size
410 || (GLRO(dl_verbose
) && sym
->st_size
< refsym
->st_size
))
414 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
416 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
417 RTLD_PROGNAME
, strtab
+ refsym
->st_name
);
419 memcpy (reloc_addr_arg
, (void *) value
,
420 MIN (sym
->st_size
, refsym
->st_size
));
423 case R_SPARC_GLOB_DAT
:
427 case R_SPARC_IRELATIVE
:
428 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
431 case R_SPARC_JMP_IREL
:
432 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
434 case R_SPARC_JMP_SLOT
:
436 #if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
437 /* Note that we don't mask the hwcap here, as the flush is
438 essential to functionality on those cpu's that implement
439 it. For sparcv9 we can assume flush is present. */
440 const int do_flush
= GLRO(dl_hwcap
) & HWCAP_SPARC_FLUSH
;
442 /* Unfortunately, this is necessary, so that we can ensure
443 ld.so will not execute corrupt PLT entry instructions. */
444 const int do_flush
= 1;
446 /* At this point we don't need to bother with thread safety,
447 so we can optimize the first instruction of .plt out. */
448 sparc_fixup_plt (reloc
, reloc_addr
, value
, 0, do_flush
);
451 #ifndef RESOLVE_CONFLICT_FIND_MAP
452 case R_SPARC_TLS_DTPMOD32
:
453 /* Get the information from the link map returned by the
456 *reloc_addr
= sym_map
->l_tls_modid
;
458 case R_SPARC_TLS_DTPOFF32
:
459 /* During relocation all TLS symbols are defined and used.
460 Therefore the offset is already correct. */
461 *reloc_addr
= (sym
== NULL
? 0 : sym
->st_value
) + reloc
->r_addend
;
463 case R_SPARC_TLS_TPOFF32
:
464 /* The offset is negative, forward from the thread pointer. */
465 /* We know the offset of object the symbol is contained in.
466 It is a negative value which will be added to the
470 CHECK_STATIC_TLS (map
, sym_map
);
471 *reloc_addr
= sym
->st_value
- sym_map
->l_tls_offset
475 # ifndef RTLD_BOOTSTRAP
476 case R_SPARC_TLS_LE_HIX22
:
477 case R_SPARC_TLS_LE_LOX10
:
480 CHECK_STATIC_TLS (map
, sym_map
);
481 value
= sym
->st_value
- sym_map
->l_tls_offset
483 if (r_type
== R_SPARC_TLS_LE_HIX22
)
484 *reloc_addr
= (*reloc_addr
& 0xffc00000) | ((~value
) >> 10);
486 *reloc_addr
= (*reloc_addr
& 0xffffe000) | (value
& 0x3ff)
492 #ifndef RTLD_BOOTSTRAP
494 *(char *) reloc_addr
= value
;
497 *(short *) reloc_addr
= value
;
500 *(char *) reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
503 *(short *) reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
506 *reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
509 *reloc_addr
= (*reloc_addr
& ~0x3ff) | (value
& 0x3ff);
511 case R_SPARC_WDISP30
:
512 *reloc_addr
= ((*reloc_addr
& 0xc0000000)
513 | ((value
- (unsigned int) reloc_addr
) >> 2));
516 *reloc_addr
= (*reloc_addr
& 0xffc00000) | (value
>> 10);
519 ((unsigned char *) reloc_addr_arg
) [0] = value
>> 8;
520 ((unsigned char *) reloc_addr_arg
) [1] = value
;
523 ((unsigned char *) reloc_addr_arg
) [0] = value
>> 24;
524 ((unsigned char *) reloc_addr_arg
) [1] = value
>> 16;
525 ((unsigned char *) reloc_addr_arg
) [2] = value
>> 8;
526 ((unsigned char *) reloc_addr_arg
) [3] = value
;
529 #if !defined RTLD_BOOTSTRAP || defined _NDEBUG
531 _dl_reloc_bad_type (map
, r_type
, 0);
538 __attribute__ ((always_inline
))
539 elf_machine_rela_relative (Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
540 void *const reloc_addr_arg
)
542 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
543 *reloc_addr
+= l_addr
+ reloc
->r_addend
;
547 __attribute__ ((always_inline
))
548 elf_machine_lazy_rel (struct link_map
*map
,
549 Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
552 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
553 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
555 if (__glibc_likely (r_type
== R_SPARC_JMP_SLOT
))
557 else if (r_type
== R_SPARC_JMP_IREL
)
559 Elf32_Addr value
= map
->l_addr
+ reloc
->r_addend
;
560 if (__glibc_likely (!skip_ifunc
))
561 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
562 sparc_fixup_plt (reloc
, reloc_addr
, value
, 1, 1);
564 else if (r_type
== R_SPARC_NONE
)
567 _dl_reloc_bad_type (map
, r_type
, 1);
570 #endif /* RESOLVE_MAP */