1 /* Machine-dependent ELF dynamic relocation inline functions. Nios II version.
2 Copyright (C) 1995-2017 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 "nios2"
28 /* Return nonzero iff ELF header is compatible with the running host. */
30 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
32 return ehdr
->e_machine
== EM_ALTERA_NIOS2
;
36 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
37 first element of the GOT. */
38 static inline Elf32_Addr
39 elf_machine_dynamic (void)
44 "1: movhi\t%1, %%hiadj(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
45 "addi\t%1, %1, %%lo(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
47 : "=r" (dynamic
), "=r" (tmp
));
52 /* Return the run-time load address of the shared object. */
53 static inline Elf32_Addr
54 elf_machine_load_address (void)
59 "1: movhi\t%1, %%hiadj(1b)\n\t"
60 "addi\t%1, %1, %%lo(1b)\n\t"
62 : "=r" (result
), "=r" (tmp
));
66 /* Set up the loaded object described by L so its unrelocated PLT
67 entries will jump to the on-demand fixup code in dl-runtime.c. */
69 static inline int __attribute__ ((always_inline
))
70 elf_machine_runtime_setup (struct link_map
*l
, int lazy
, int profile
)
72 extern void _dl_runtime_resolve (Elf32_Word
);
74 if (l
->l_info
[DT_JMPREL
] && lazy
)
76 /* The GOT entries for functions in the PLT have not yet been filled
77 in. Their initial contents will arrange when called to load r15 with
78 an offset into the .got section, load r14 with
79 _GLOBAL_OFFSET_TABLE_[1], and then jump to _GLOBAL_OFFSET_TABLE[2].
81 Elf32_Addr
*got
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
82 got
[1] = (Elf32_Addr
) l
; /* Identify this shared object. */
84 /* This function will get called to fix up the GOT entry indicated by
85 the offset on the stack, and then jump to the resolved address. */
86 got
[2] = (Elf32_Addr
) &_dl_runtime_resolve
;
92 /* Initial entry point code for the dynamic linker.
93 The C function `_dl_start' is the real entry point;
94 its return value is the user program's entry point. */
96 #define RTLD_START asm ("\
99 .type _start, %function\n\
101 /* At start time, all the args are on the stack. */\n\
104 /* Start the calculation of the GOT pointer. */\n\
106 1: movhi r8, %hiadj(_gp_got - 1b)\n\
107 addi r8, r8, %lo(_gp_got - 1b)\n\
109 /* Figure out where _dl_start will need to return to. */\n\
110 movhi ra, %hiadj(2f - 1b)\n\
111 addi ra, ra, %lo(2f - 1b)\n\
114 /* Finish the calculation of the GOT pointer. */\n\
119 /* Save the returned user entry point. */\n\
122 /* Initialize gp. */\n\
123 ldw r4, %got(_rtld_local)(r22)\n\
125 ldw r8, %call(_dl_nios2_get_gp_value)(r22)\n\
129 /* Find the number of arguments to skip. */\n\
130 ldw r8, %got(_dl_skip_args)(r22)\n\
133 /* Find the main_map from the GOT. */\n\
134 ldw r4, %got(_rtld_local)(r22)\n\
142 /* Find the first unskipped argument. */\n\
148 /* Shuffle argv down. */\n\
155 /* Shuffle envp down. */\n\
163 /* Shuffle auxv down. */\n\
172 /* Update _dl_argv. */\n\
173 ldw r2, %got(_dl_argv)(r22)\n\
176 /* Call _dl_init through the PLT. */\n\
177 ldw r8, %call(_dl_init)(r22)\n\
180 /* Find the finalization function. */\n\
181 ldw r4, %got(_dl_fini)(r22)\n\
183 /* Jump to the user's entry point. */\n\
187 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
188 PLT entries should not be allowed to define the value.
189 ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
190 of the main executable's symbols, as for a COPY reloc. */
191 #define elf_machine_type_class(type) \
192 ((((type) == R_NIOS2_JUMP_SLOT \
193 || (type) == R_NIOS2_TLS_DTPMOD \
194 || (type) == R_NIOS2_TLS_DTPREL \
195 || (type) == R_NIOS2_TLS_TPREL) * ELF_RTYPE_CLASS_PLT) \
196 | (((type) == R_NIOS2_COPY) * ELF_RTYPE_CLASS_COPY) \
197 | (((type) == R_NIOS2_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
199 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
200 #define ELF_MACHINE_JMP_SLOT R_NIOS2_JUMP_SLOT
202 /* The Nios II never uses Elf32_Rel relocations. */
203 #define ELF_MACHINE_NO_REL 1
204 #define ELF_MACHINE_NO_RELA 0
206 /* Fixup a PLT entry to bounce directly to the function at VALUE. */
208 static inline Elf32_Addr
209 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
210 const ElfW(Sym
) *refsym
, const ElfW(Sym
) *sym
,
211 const Elf32_Rela
*reloc
,
212 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
214 return *reloc_addr
= value
;
217 /* Return the final value of a plt relocation. */
218 static inline Elf32_Addr
219 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
225 /* Names of the architecture-specific auditing callback functions. */
226 #define ARCH_LA_PLTENTER nios2_gnu_pltenter
227 #define ARCH_LA_PLTEXIT nios2_gnu_pltexit
229 #endif /* dl_machine_h */
233 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
234 LOADADDR is the load address of the object; INFO is an array indexed
235 by DT_* of the .dynamic section info. */
237 auto inline void __attribute__ ((always_inline
))
238 elf_machine_rela (struct link_map
*map
, const ElfW(Rela
) *reloc
,
239 const ElfW(Sym
) *sym
, const struct r_found_version
*version
,
240 void *const reloc_addr_arg
, int skip_ifunc
)
242 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
243 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
245 if (__glibc_unlikely (r_type
== R_NIOS2_RELATIVE
))
246 *reloc_addr
= map
->l_addr
+ reloc
->r_addend
;
247 else if (__glibc_unlikely (r_type
== R_NIOS2_NONE
))
251 const Elf32_Sym
*const refsym
= sym
;
252 struct link_map
*sym_map
= RESOLVE_MAP (&sym
, version
, r_type
);
253 Elf32_Addr value
= sym
== NULL
? 0 : sym_map
->l_addr
+ sym
->st_value
;
259 /* This can happen in trace mode if an object could not be
262 if (sym
->st_size
> refsym
->st_size
263 || (sym
->st_size
< refsym
->st_size
&& GLRO(dl_verbose
)))
267 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
269 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
270 rtld_progname
?: "<program name unknown>",
271 strtab
+ refsym
->st_name
);
273 memcpy (reloc_addr_arg
, (void *) value
,
274 MIN (sym
->st_size
, refsym
->st_size
));
276 case R_NIOS2_GLOB_DAT
:
277 case R_NIOS2_JUMP_SLOT
:
278 # ifdef RTLD_BOOTSTRAP
279 /* Fix weak undefined references. */
280 if (sym
!= NULL
&& sym
->st_value
== 0)
286 #ifndef RTLD_BOOTSTRAP
287 case R_NIOS2_TLS_DTPMOD
:
288 /* Get the information from the link map returned by the
291 *reloc_addr
= sym_map
->l_tls_modid
;
294 case R_NIOS2_TLS_DTPREL
:
295 *reloc_addr
= reloc
->r_addend
+ TLS_DTPREL_VALUE(sym
);
298 case R_NIOS2_TLS_TPREL
:
301 CHECK_STATIC_TLS (map
, sym_map
);
302 *reloc_addr
= reloc
->r_addend
+ TLS_TPREL_VALUE(sym_map
, sym
);
306 case R_NIOS2_BFD_RELOC_32
:
307 *reloc_addr
= value
+ reloc
->r_addend
;
311 _dl_reloc_bad_type (map
, r_type
, 0);
317 auto inline void __attribute__((always_inline
))
318 elf_machine_rela_relative (ElfW(Addr
) l_addr
, const ElfW(Rela
) *reloc
,
319 void *const reloc_addr_arg
)
321 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
322 *reloc_addr
= l_addr
+ reloc
->r_addend
;
325 auto inline void __attribute__((always_inline
))
326 elf_machine_lazy_rel (struct link_map
*map
,
327 ElfW(Addr
) l_addr
, const ElfW(Rela
) *reloc
,
330 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
331 if (ELF32_R_TYPE (reloc
->r_info
) == R_NIOS2_JUMP_SLOT
)
332 *reloc_addr
+= l_addr
;
334 _dl_reloc_bad_type (map
, ELF32_R_TYPE (reloc
->r_info
), 1);
337 #endif /* RESOLVE_MAP */