1 /* Machine-dependent ELF dynamic relocation inline functions. SPARC version.
2 Copyright (C) 1996-2024 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 <https://www.gnu.org/licenses/>. */
22 #define ELF_MACHINE_NAME "sparc"
25 #include <sys/param.h>
30 #include <elf/dl-hwcaps.h>
31 #include <dl-static-tls.h>
32 #include <dl-machine-rel.h>
34 /* Return nonzero iff ELF header is compatible with the running host. */
36 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
38 if (ehdr
->e_machine
== EM_SPARC
)
40 else if (ehdr
->e_machine
== EM_SPARC32PLUS
)
43 uint64_t hwcap_mask
= TUNABLE_GET (glibc
, cpu
, hwcap_mask
, uint64_t,
45 return GLRO(dl_hwcap
) & hwcap_mask
& HWCAP_SPARC_V9
;
47 return GLRO(dl_hwcap
) & HWCAP_SPARC_V9
;
54 /* We have to do this because elf_machine_{dynamic,load_address} can be
55 invoked from functions that have no GOT references, and thus the compiler
56 has no obligation to load the PIC register. */
57 #define LOAD_PIC_REG(PIC_REG) \
58 do { register Elf32_Addr pc __asm("o7"); \
59 __asm("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t" \
61 "add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n" \
62 "1:\tadd %1, %0, %1" \
63 : "=r" (pc), "=r" (PIC_REG)); \
66 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
67 first element of the GOT. This must be inlined in a function which
69 static inline Elf32_Addr
70 elf_machine_dynamic (void)
72 register Elf32_Addr
*got
asm ("%l7");
79 /* Return the run-time load address of the shared object. */
80 static inline Elf32_Addr
81 elf_machine_load_address (void)
83 register Elf32_Addr
*pc
__asm ("%o7"), *got
__asm ("%l7");
85 __asm ("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t"
87 " add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n\t"
89 "call _GLOBAL_OFFSET_TABLE_\n"
90 "1:\tadd %1, %0, %1\n\t" : "=r" (pc
), "=r" (got
));
92 /* got is now l_addr + _GLOBAL_OFFSET_TABLE_
94 pc[2]*4 is l_addr + _DYNAMIC - (long)pc - 8
95 pc[3]*4 is l_addr + _GLOBAL_OFFSET_TABLE_ - (long)pc - 12 */
96 return (Elf32_Addr
) got
- *got
+ (pc
[2] - pc
[3]) * 4 - 4;
99 /* Set up the loaded object described by L so its unrelocated PLT
100 entries will jump to the on-demand fixup code in dl-runtime.c. */
103 elf_machine_runtime_setup (struct link_map
*l
, struct r_scope_elem
*scope
[],
104 int lazy
, int profile
)
107 extern void _dl_runtime_resolve (Elf32_Word
);
108 extern void _dl_runtime_profile (Elf32_Word
);
110 if (l
->l_info
[DT_JMPREL
] && lazy
)
114 /* The entries for functions in the PLT have not yet been filled in.
115 Their initial contents will arrange when called to set the high 22
116 bits of %g1 with an offset into the .rela.plt section and jump to
117 the beginning of the PLT. */
118 plt
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
120 if (__glibc_unlikely (profile
))
122 rfunc
= (Elf32_Addr
) &_dl_runtime_profile
;
124 if (GLRO(dl_profile
) != NULL
125 && _dl_name_match_p (GLRO(dl_profile
), l
))
126 GL(dl_profile_map
) = l
;
131 rfunc
= (Elf32_Addr
) &_dl_runtime_resolve
;
134 /* The beginning of the PLT does:
136 sethi %hi(_dl_runtime_{resolve,profile}), %g2
137 pltpc: jmpl %g2 + %lo(_dl_runtime_{resolve,profile}), %g2
141 The PC value (pltpc) saved in %g2 by the jmpl points near the
142 location where we store the link_map pointer for this object. */
144 plt
[0] = 0x05000000 | ((rfunc
>> 10) & 0x003fffff);
145 plt
[1] = 0x85c0a000 | (rfunc
& 0x3ff);
146 plt
[2] = OPCODE_NOP
; /* Fill call delay slot. */
147 plt
[3] = (Elf32_Addr
) l
;
153 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
154 PLT entries should not be allowed to define the value.
155 ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
156 of the main executable's symbols, as for a COPY reloc. */
157 #define elf_machine_type_class(type) \
158 ((((type) == R_SPARC_JMP_SLOT \
159 || ((type) >= R_SPARC_TLS_GD_HI22 && (type) <= R_SPARC_TLS_TPOFF64)) \
160 * ELF_RTYPE_CLASS_PLT) \
161 | (((type) == R_SPARC_COPY) * ELF_RTYPE_CLASS_COPY))
163 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
164 #define ELF_MACHINE_JMP_SLOT R_SPARC_JMP_SLOT
166 /* Undo the sub %sp, 6*4, %sp; add %sp, 22*4, %o0 below to get at the
167 value we want in __libc_stack_end. */
168 #define DL_STACK_END(cookie) \
169 ((void *) (((long) (cookie)) - (22 - 6) * 4))
171 /* Initial entry point code for the dynamic linker.
172 The C function `_dl_start' is the real entry point;
173 its return value is the user program's entry point. */
175 #define RTLD_GOT_ADDRESS(pic_reg, reg, symbol) \
176 "sethi %gdop_hix22(" #symbol "), " #reg "\n\t" \
177 "xor " #reg ", %gdop_lox10(" #symbol "), " #reg "\n\t" \
178 "ld [" #pic_reg " + " #reg "], " #reg ", %gdop(" #symbol ")"
180 #define RTLD_START __asm__ ("\
183 .type _start, @function\n\
186 /* Allocate space for functions to drop their arguments. */\n\
188 /* Pass pointer to argument block to _dl_start. */\n\
190 add %sp, 22*4, %o0\n\
192 .globl _dl_start_user\n\
193 .type _dl_start_user, @function\n\
195 /* Load the PIC register. */\n\
197 sethi %hi(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
198 2: or %l7, %lo(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
200 /* Save the user entry point address in %l0 */\n\
202 ld [%sp+22*4], %i5 /* load argc */\n\
203 /* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp. */\n\
204 " RTLD_GOT_ADDRESS(%l7, %o0, _rtld_local) "\n\
205 add %sp, 23*4, %o2\n\
212 /* Pass our finalizer function to the user in %g1. */\n\
213 " RTLD_GOT_ADDRESS(%l7, %g1, _dl_fini) "\n\
214 /* Jump to the user's entry point and deallocate the extra stack we got. */\n\
217 .size _dl_start_user, . - _dl_start_user\n\
220 static inline Elf32_Addr
221 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
222 const ElfW(Sym
) *refsym
, const ElfW(Sym
) *sym
,
223 const Elf32_Rela
*reloc
,
224 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
227 /* Sparc v9 can assume flush is always present. */
228 const int do_flush
= 1;
230 /* Note that we don't mask the hwcap here, as the flush is essential to
231 functionality on those cpu's that implement it. */
232 const int do_flush
= GLRO(dl_hwcap
) & HWCAP_SPARC_FLUSH
;
234 return sparc_fixup_plt (reloc
, reloc_addr
, value
, 1, do_flush
);
237 /* Return the final value of a plt relocation. */
238 static inline Elf32_Addr
239 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
242 return value
+ reloc
->r_addend
;
245 #endif /* dl_machine_h */
247 #define ARCH_LA_PLTENTER sparc32_gnu_pltenter
248 #define ARCH_LA_PLTEXIT sparc32_gnu_pltexit
252 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
253 MAP is the object containing the reloc. */
256 __attribute__ ((always_inline
))
257 elf_machine_rela (struct link_map
*map
, struct r_scope_elem
*scope
[],
258 const Elf32_Rela
*reloc
, const Elf32_Sym
*sym
,
259 const struct r_found_version
*version
,
260 void *const reloc_addr_arg
, int skip_ifunc
)
262 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
263 #if !defined RTLD_BOOTSTRAP
264 const Elf32_Sym
*const refsym
= sym
;
267 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
268 struct link_map
*sym_map
= NULL
;
270 if (__glibc_unlikely (r_type
== R_SPARC_NONE
))
273 if (__glibc_unlikely (r_type
== R_SPARC_SIZE32
))
275 *reloc_addr
= sym
->st_size
+ reloc
->r_addend
;
279 #if !defined RTLD_BOOTSTRAP
280 if (__glibc_unlikely (r_type
== R_SPARC_RELATIVE
))
282 *reloc_addr
+= map
->l_addr
+ reloc
->r_addend
;
287 if (__builtin_expect (ELF32_ST_BIND (sym
->st_info
) == STB_LOCAL
, 0)
288 && sym
->st_shndx
!= SHN_UNDEF
)
295 sym_map
= RESOLVE_MAP (map
, scope
, &sym
, version
, r_type
);
296 value
= SYMBOL_ADDRESS (sym_map
, sym
, true);
299 value
+= reloc
->r_addend
; /* Assume copy relocs have zero addend. */
302 && __builtin_expect (ELFW(ST_TYPE
) (sym
->st_info
) == STT_GNU_IFUNC
, 0)
303 && __builtin_expect (sym
->st_shndx
!= SHN_UNDEF
, 1)
304 && __builtin_expect (!skip_ifunc
, 1))
306 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
311 #if !defined RTLD_BOOTSTRAP
314 /* This can happen in trace mode if an object could not be
317 if (sym
->st_size
> refsym
->st_size
318 || (GLRO(dl_verbose
) && sym
->st_size
< refsym
->st_size
))
322 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
324 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
325 RTLD_PROGNAME
, strtab
+ refsym
->st_name
);
327 memcpy (reloc_addr_arg
, (void *) value
,
328 MIN (sym
->st_size
, refsym
->st_size
));
331 case R_SPARC_GLOB_DAT
:
335 case R_SPARC_IRELATIVE
:
336 if (__glibc_likely (!skip_ifunc
))
337 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
340 case R_SPARC_JMP_IREL
:
341 if (__glibc_likely (!skip_ifunc
))
342 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
344 case R_SPARC_JMP_SLOT
:
346 #if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
347 /* Note that we don't mask the hwcap here, as the flush is
348 essential to functionality on those cpu's that implement
349 it. For sparcv9 we can assume flush is present. */
350 const int do_flush
= GLRO(dl_hwcap
) & HWCAP_SPARC_FLUSH
;
352 /* Unfortunately, this is necessary, so that we can ensure
353 ld.so will not execute corrupt PLT entry instructions. */
354 const int do_flush
= 1;
356 /* At this point we don't need to bother with thread safety,
357 so we can optimize the first instruction of .plt out. */
358 sparc_fixup_plt (reloc
, reloc_addr
, value
, 0, do_flush
);
361 case R_SPARC_TLS_DTPMOD32
:
362 /* Get the information from the link map returned by the
365 *reloc_addr
= sym_map
->l_tls_modid
;
367 case R_SPARC_TLS_DTPOFF32
:
368 /* During relocation all TLS symbols are defined and used.
369 Therefore the offset is already correct. */
370 *reloc_addr
= (sym
== NULL
? 0 : sym
->st_value
) + reloc
->r_addend
;
372 case R_SPARC_TLS_TPOFF32
:
373 /* The offset is negative, forward from the thread pointer. */
374 /* We know the offset of object the symbol is contained in.
375 It is a negative value which will be added to the
379 CHECK_STATIC_TLS (map
, sym_map
);
380 *reloc_addr
= sym
->st_value
- sym_map
->l_tls_offset
384 #ifndef RTLD_BOOTSTRAP
385 case R_SPARC_TLS_LE_HIX22
:
386 case R_SPARC_TLS_LE_LOX10
:
389 CHECK_STATIC_TLS (map
, sym_map
);
390 value
= sym
->st_value
- sym_map
->l_tls_offset
392 if (r_type
== R_SPARC_TLS_LE_HIX22
)
393 *reloc_addr
= (*reloc_addr
& 0xffc00000) | ((~value
) >> 10);
395 *reloc_addr
= (*reloc_addr
& 0xffffe000) | (value
& 0x3ff)
400 #ifndef RTLD_BOOTSTRAP
402 *(char *) reloc_addr
= value
;
405 *(short *) reloc_addr
= value
;
408 *(char *) reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
411 *(short *) reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
414 *reloc_addr
= (value
- (Elf32_Addr
) reloc_addr
);
417 *reloc_addr
= (*reloc_addr
& ~0x3ff) | (value
& 0x3ff);
419 case R_SPARC_WDISP30
:
420 *reloc_addr
= ((*reloc_addr
& 0xc0000000)
421 | ((value
- (unsigned int) reloc_addr
) >> 2));
424 *reloc_addr
= (*reloc_addr
& 0xffc00000) | (value
>> 10);
427 ((unsigned char *) reloc_addr_arg
) [0] = value
>> 8;
428 ((unsigned char *) reloc_addr_arg
) [1] = value
;
431 ((unsigned char *) reloc_addr_arg
) [0] = value
>> 24;
432 ((unsigned char *) reloc_addr_arg
) [1] = value
>> 16;
433 ((unsigned char *) reloc_addr_arg
) [2] = value
>> 8;
434 ((unsigned char *) reloc_addr_arg
) [3] = value
;
437 #if !defined RTLD_BOOTSTRAP || defined _NDEBUG
439 _dl_reloc_bad_type (map
, r_type
, 0);
446 __attribute__ ((always_inline
))
447 elf_machine_rela_relative (Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
448 void *const reloc_addr_arg
)
450 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
451 *reloc_addr
+= l_addr
+ reloc
->r_addend
;
455 __attribute__ ((always_inline
))
456 elf_machine_lazy_rel (struct link_map
*map
, struct r_scope_elem
*scope
[],
457 Elf32_Addr l_addr
, const Elf32_Rela
*reloc
,
460 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
461 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
463 if (__glibc_likely (r_type
== R_SPARC_JMP_SLOT
))
465 else if (r_type
== R_SPARC_JMP_IREL
)
467 Elf32_Addr value
= map
->l_addr
+ reloc
->r_addend
;
468 if (__glibc_likely (!skip_ifunc
))
469 value
= ((Elf32_Addr (*) (int)) value
) (GLRO(dl_hwcap
));
470 sparc_fixup_plt (reloc
, reloc_addr
, value
, 1, 1);
472 else if (r_type
== R_SPARC_NONE
)
475 _dl_reloc_bad_type (map
, r_type
, 1);
478 #endif /* RESOLVE_MAP */