1 /* Machine-dependent ELF dynamic relocation inline functions. m68k version.
2 Copyright (C) 1996-2001, 2002, 2003, 2004, 2005 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, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 #define ELF_MACHINE_NAME "m68k"
25 #include <sys/param.h>
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_68K;
36 /* Return the link-time address of _DYNAMIC.
37 This must be inlined in a function which uses global data. */
38 static inline Elf32_Addr
39 elf_machine_dynamic (void)
43 asm ("move.l _DYNAMIC@GOT.w(%%a5), %0"
49 /* Return the run-time load address of the shared object. */
50 static inline Elf32_Addr
51 elf_machine_load_address (void)
54 asm (PCREL_OP ("lea", "_dl_start", "%0", "%0", "%%pc") "\n\t"
55 "sub.l _dl_start@GOT.w(%%a5), %0"
61 /* Set up the loaded object described by L so its unrelocated PLT
62 entries will jump to the on-demand fixup code in dl-runtime.c. */
64 static inline int __attribute__ ((always_inline))
65 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
68 extern void _dl_runtime_resolve (Elf32_Word);
69 extern void _dl_runtime_profile (Elf32_Word);
71 if (l->l_info[DT_JMPREL] && lazy)
73 /* The GOT entries for functions in the PLT have not yet been
74 filled in. Their initial contents will arrange when called
75 to push an offset into the .rela.plt section, push
76 _GLOBAL_OFFSET_TABLE_[1], and then jump to
77 _GLOBAL_OFFSET_TABLE_[2]. */
78 got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
79 got[1] = (Elf32_Addr) l; /* Identify this shared object. */
81 /* The got[2] entry contains the address of a function which gets
82 called to get the address of a so far unresolved function and
83 jump to it. The profiling extension of the dynamic linker allows
84 to intercept the calls to collect information. In this case we
85 don't store the address in the GOT so that all future calls also
86 end in this function. */
89 got[2] = (Elf32_Addr) &_dl_runtime_profile;
91 if (GLRO(dl_profile) != NULL
92 && _dl_name_match_p (GLRO(dl_profile), l))
94 /* This is the object we are looking for. Say that we really
95 want profiling and the timers are started. */
96 GL(dl_profile_map) = l;
100 /* This function will get called to fix up the GOT entry indicated by
101 the offset on the stack, and then jump to the resolved address. */
102 got[2] = (Elf32_Addr) &_dl_runtime_resolve;
108 #define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0, long int save_a1
111 /* Mask identifying addresses reserved for the user program,
112 where the dynamic linker should not map anything. */
113 #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
115 /* Initial entry point code for the dynamic linker.
116 The C function `_dl_start' is the real entry point;
117 its return value is the user program's entry point. */
119 #define RTLD_START asm ("\
122 .type _start,@function\n\
124 move.l %sp, -(%sp)\n\
129 .globl _dl_start_user\n\
130 .type _dl_start_user,@function\n\
132 | Save the user entry point address in %a4.\n\
134 | See if we were run as a command with the executable file\n\
135 | name as an extra leading argument.\n\
136 " PCREL_OP ("move.l", "_dl_skip_args", "%d0", "%d0", "%pc") "\n\
137 | Pop the original argument count\n\
138 move.l (%sp)+, %d1\n\
139 | Subtract _dl_skip_args from it.\n\
141 | Adjust the stack pointer to skip _dl_skip_args words.\n\
142 lea (%sp, %d0*4), %sp\n\
143 | Push back the modified argument count.\n\
144 move.l %d1, -(%sp)\n\
145 # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
148 move.l %d1, -(%sp)\n\
149 " PCREL_OP ("move.l", "_rtld_local", "-(%sp)", "%d0", "%pc") "\n\
150 jbsr _dl_init_internal@PLTPC\n\
153 | Pass our finalizer function to the user in %a1.\n\
154 " PCREL_OP ("lea", "_dl_fini", "%a1", "%a1", "%pc") "\n\
155 | Initialize %fp with the stack pointer.\n\
157 | Jump to the user's entry point.\n\
159 .size _dl_start_user, . - _dl_start_user\n\
162 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
163 PLT entries should not be allowed to define the value.
164 ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
165 of the main executable's symbols, as for a COPY reloc. */
166 #define elf_machine_type_class(type) \
167 ((((type) == R_68K_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
168 | (((type) == R_68K_COPY) * ELF_RTYPE_CLASS_COPY))
170 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
171 #define ELF_MACHINE_JMP_SLOT R_68K_JMP_SLOT
173 /* The m68k never uses Elf32_Rel relocations. */
174 #define ELF_MACHINE_NO_REL 1
176 static inline Elf32_Addr
177 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
178 const Elf32_Rela *reloc,
179 Elf32_Addr *reloc_addr, Elf32_Addr value)
181 return *reloc_addr = value;
184 /* Return the final value of a plt relocation. On the m68k the JMP_SLOT
185 relocation ignores the addend. */
186 static inline Elf32_Addr
187 elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
193 /* Names of the architecture-specific auditing callback functions. */
194 #define ARCH_LA_PLTENTER m68k_gnu_pltenter
195 #define ARCH_LA_PLTEXIT m68k_gnu_pltexit
197 #endif /* !dl_machine_h */
201 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
202 MAP is the object containing the reloc. */
204 auto inline void __attribute__ ((unused, always_inline))
205 elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
206 const Elf32_Sym *sym, const struct r_found_version *version,
207 void *const reloc_addr_arg)
209 Elf32_Addr *const reloc_addr = reloc_addr_arg;
210 const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
212 if (__builtin_expect (r_type == R_68K_RELATIVE, 0))
213 *reloc_addr = map->l_addr + reloc->r_addend;
216 const Elf32_Sym *const refsym = sym;
217 struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
218 Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
224 /* This can happen in trace mode if an object could not be
227 if (sym->st_size > refsym->st_size
228 || (sym->st_size < refsym->st_size && GLRO(dl_verbose)))
232 strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
234 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
235 rtld_progname ?: "<program name unknown>",
236 strtab + refsym->st_name);
238 memcpy (reloc_addr_arg, (void *) value,
239 MIN (sym->st_size, refsym->st_size));
246 *(char *) reloc_addr = value + reloc->r_addend;
249 *(short *) reloc_addr = value + reloc->r_addend;
252 *reloc_addr = value + reloc->r_addend;
256 = value + reloc->r_addend - (Elf32_Addr) reloc_addr;
259 *(short *) reloc_addr
260 = value + reloc->r_addend - (Elf32_Addr) reloc_addr;
263 *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr;
265 case R_68K_NONE: /* Alright, Wilbur. */
268 _dl_reloc_bad_type (map, r_type, 0);
274 auto inline void __attribute__ ((unused, always_inline))
275 elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
276 void *const reloc_addr_arg)
278 Elf32_Addr *const reloc_addr = reloc_addr_arg;
279 *reloc_addr = l_addr + reloc->r_addend;
282 auto inline void __attribute__ ((unused, always_inline))
283 elf_machine_lazy_rel (struct link_map *map,
284 Elf32_Addr l_addr, const Elf32_Rela *reloc)
286 Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
287 if (ELF32_R_TYPE (reloc->r_info) == R_68K_JMP_SLOT)
288 *reloc_addr += l_addr;
290 _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
293 #endif /* RESOLVE_MAP */