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| 1 | /* Machine-dependent ELF dynamic relocation inline functions. m68k version. |
|---|---|
| 2 | Copyright (C) 1996-2022 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 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. |
| 9 | |
| 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. |
| 14 | |
| 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/>. */ |
| 18 | |
| 19 | #ifndef dl_machine_h |
| 20 | #define dl_machine_h |
| 21 | |
| 22 | #define ELF_MACHINE_NAME "m68k" |
| 23 | |
| 24 | #include <sys/param.h> |
| 25 | #include <sysdep.h> |
| 26 | #include <dl-tls.h> |
| 27 | #include <dl-static-tls.h> |
| 28 | #include <dl-machine-rel.h> |
| 29 | |
| 30 | /* Return nonzero iff ELF header is compatible with the running host. */ |
| 31 | static inline int |
| 32 | elf_machine_matches_host (const Elf32_Ehdr *ehdr) |
| 33 | { |
| 34 | return ehdr->e_machine == EM_68K; |
| 35 | } |
| 36 | |
| 37 | |
| 38 | /* Return the link-time address of _DYNAMIC. |
| 39 | This must be inlined in a function which uses global data. */ |
| 40 | static inline Elf32_Addr |
| 41 | elf_machine_dynamic (void) |
| 42 | { |
| 43 | Elf32_Addr addr; |
| 44 | |
| 45 | asm ("move.l _DYNAMIC@GOT.w(%%a5), %0" |
| 46 | : "=a" (addr)); |
| 47 | return addr; |
| 48 | } |
| 49 | |
| 50 | |
| 51 | /* Return the run-time load address of the shared object. */ |
| 52 | static inline Elf32_Addr |
| 53 | elf_machine_load_address (void) |
| 54 | { |
| 55 | Elf32_Addr addr; |
| 56 | #ifdef SHARED |
| 57 | asm (PCREL_OP ("lea", "_dl_start", "%0", "%0", "%%pc") "\n\t" |
| 58 | "sub.l _dl_start@GOT.w(%%a5), %0" |
| 59 | : "=a" (addr)); |
| 60 | #else |
| 61 | asm (PCREL_OP ("lea", "_dl_relocate_static_pie", "%0", "%0", "%%pc") "\n\t" |
| 62 | "sub.l _dl_relocate_static_pie@GOT.w(%%a5), %0" |
| 63 | : "=a" (addr)); |
| 64 | #endif |
| 65 | return addr; |
| 66 | } |
| 67 | |
| 68 | |
| 69 | /* Set up the loaded object described by L so its unrelocated PLT |
| 70 | entries will jump to the on-demand fixup code in dl-runtime.c. */ |
| 71 | |
| 72 | static inline int __attribute__ ((always_inline)) |
| 73 | elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[], |
| 74 | int lazy, int profile) |
| 75 | { |
| 76 | Elf32_Addr *got; |
| 77 | extern void _dl_runtime_resolve (Elf32_Word); |
| 78 | extern void _dl_runtime_profile (Elf32_Word); |
| 79 | |
| 80 | if (l->l_info[DT_JMPREL] && lazy) |
| 81 | { |
| 82 | /* The GOT entries for functions in the PLT have not yet been |
| 83 | filled in. Their initial contents will arrange when called |
| 84 | to push an offset into the .rela.plt section, push |
| 85 | _GLOBAL_OFFSET_TABLE_[1], and then jump to |
| 86 | _GLOBAL_OFFSET_TABLE_[2]. */ |
| 87 | got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); |
| 88 | got[1] = (Elf32_Addr) l; /* Identify this shared object. */ |
| 89 | |
| 90 | /* The got[2] entry contains the address of a function which gets |
| 91 | called to get the address of a so far unresolved function and |
| 92 | jump to it. The profiling extension of the dynamic linker allows |
| 93 | to intercept the calls to collect information. In this case we |
| 94 | don't store the address in the GOT so that all future calls also |
| 95 | end in this function. */ |
| 96 | if (profile) |
| 97 | { |
| 98 | got[2] = (Elf32_Addr) &_dl_runtime_profile; |
| 99 | |
| 100 | if (GLRO(dl_profile) != NULL |
| 101 | && _dl_name_match_p (GLRO(dl_profile), l)) |
| 102 | { |
| 103 | /* This is the object we are looking for. Say that we really |
| 104 | want profiling and the timers are started. */ |
| 105 | GL(dl_profile_map) = l; |
| 106 | } |
| 107 | } |
| 108 | else |
| 109 | /* This function will get called to fix up the GOT entry indicated by |
| 110 | the offset on the stack, and then jump to the resolved address. */ |
| 111 | got[2] = (Elf32_Addr) &_dl_runtime_resolve; |
| 112 | } |
| 113 | |
| 114 | return lazy; |
| 115 | } |
| 116 | |
| 117 | #define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0, long int save_a1 |
| 118 | #define ELF_MACHINE_RUNTIME_FIXUP_PARAMS save_a0, save_a1 |
| 119 | |
| 120 | |
| 121 | /* Mask identifying addresses reserved for the user program, |
| 122 | where the dynamic linker should not map anything. */ |
| 123 | #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL |
| 124 | |
| 125 | /* Initial entry point code for the dynamic linker. |
| 126 | The C function `_dl_start' is the real entry point; |
| 127 | its return value is the user program's entry point. */ |
| 128 | |
| 129 | #define RTLD_START asm ("\ |
| 130 | .text\n\ |
| 131 | .globl _start\n\ |
| 132 | .type _start,@function\n\ |
| 133 | _start:\n\ |
| 134 | sub.l %fp, %fp\n\ |
| 135 | move.l %sp, -(%sp)\n\ |
| 136 | jbsr _dl_start\n\ |
| 137 | addq.l #4, %sp\n\ |
| 138 | /* FALLTHRU */\n\ |
| 139 | \n\ |
| 140 | .globl _dl_start_user\n\ |
| 141 | .type _dl_start_user,@function\n\ |
| 142 | _dl_start_user:\n\ |
| 143 | | Save the user entry point address in %a4.\n\ |
| 144 | move.l %d0, %a4\n\ |
| 145 | | See if we were run as a command with the executable file\n\ |
| 146 | | name as an extra leading argument.\n\ |
| 147 | " PCREL_OP ("move.l", "_dl_skip_args", "%d0", "%d0", "%pc") "\n\ |
| 148 | | Pop the original argument count\n\ |
| 149 | move.l (%sp)+, %d1\n\ |
| 150 | | Subtract _dl_skip_args from it.\n\ |
| 151 | sub.l %d0, %d1\n\ |
| 152 | | Adjust the stack pointer to skip _dl_skip_args words.\n\ |
| 153 | lea (%sp, %d0*4), %sp\n\ |
| 154 | | Push back the modified argument count.\n\ |
| 155 | move.l %d1, -(%sp)\n\ |
| 156 | # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\ |
| 157 | pea 8(%sp, %d1*4)\n\ |
| 158 | pea 8(%sp)\n\ |
| 159 | move.l %d1, -(%sp)\n\ |
| 160 | " PCREL_OP ("move.l", "_rtld_local", "-(%sp)", "%d0", "%pc") "\n\ |
| 161 | jbsr _dl_init\n\ |
| 162 | addq.l #8, %sp\n\ |
| 163 | addq.l #8, %sp\n\ |
| 164 | | Pass our finalizer function to the user in %a1.\n\ |
| 165 | " PCREL_OP ("lea", "_dl_fini", "%a1", "%a1", "%pc") "\n\ |
| 166 | | Initialize %fp with the stack pointer.\n\ |
| 167 | move.l %sp, %fp\n\ |
| 168 | | Jump to the user's entry point.\n\ |
| 169 | jmp (%a4)\n\ |
| 170 | .size _dl_start_user, . - _dl_start_user\n\ |
| 171 | .previous"); |
| 172 | |
| 173 | /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or |
| 174 | TLS variable, so undefined references should not be allowed to |
| 175 | define the value. |
| 176 | ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one |
| 177 | of the main executable's symbols, as for a COPY reloc. */ |
| 178 | #define elf_machine_type_class(type) \ |
| 179 | ((((type) == R_68K_JMP_SLOT \ |
| 180 | || (type) == R_68K_TLS_DTPMOD32 \ |
| 181 | || (type) == R_68K_TLS_DTPREL32 \ |
| 182 | || (type) == R_68K_TLS_TPREL32) * ELF_RTYPE_CLASS_PLT) \ |
| 183 | | (((type) == R_68K_COPY) * ELF_RTYPE_CLASS_COPY)) |
| 184 | |
| 185 | /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ |
| 186 | #define ELF_MACHINE_JMP_SLOT R_68K_JMP_SLOT |
| 187 | |
| 188 | static inline Elf32_Addr |
| 189 | elf_machine_fixup_plt (struct link_map *map, lookup_t t, |
| 190 | const ElfW(Sym) *refsym, const ElfW(Sym) *sym, |
| 191 | const Elf32_Rela *reloc, |
| 192 | Elf32_Addr *reloc_addr, Elf32_Addr value) |
| 193 | { |
| 194 | return *reloc_addr = value; |
| 195 | } |
| 196 | |
| 197 | /* Return the final value of a plt relocation. On the m68k the JMP_SLOT |
| 198 | relocation ignores the addend. */ |
| 199 | static inline Elf32_Addr |
| 200 | elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc, |
| 201 | Elf32_Addr value) |
| 202 | { |
| 203 | return value; |
| 204 | } |
| 205 | |
| 206 | /* Names of the architecture-specific auditing callback functions. */ |
| 207 | #define ARCH_LA_PLTENTER m68k_gnu_pltenter |
| 208 | #define ARCH_LA_PLTEXIT m68k_gnu_pltexit |
| 209 | |
| 210 | #endif /* !dl_machine_h */ |
| 211 | |
| 212 | #ifdef RESOLVE_MAP |
| 213 | |
| 214 | /* Perform the relocation specified by RELOC and SYM (which is fully resolved). |
| 215 | MAP is the object containing the reloc. */ |
| 216 | |
| 217 | static inline void __attribute__ ((unused, always_inline)) |
| 218 | elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], |
| 219 | const Elf32_Rela *reloc, const Elf32_Sym *sym, |
| 220 | const struct r_found_version *version, |
| 221 | void *const reloc_addr_arg, int skip_ifunc) |
| 222 | { |
| 223 | Elf32_Addr *const reloc_addr = reloc_addr_arg; |
| 224 | const unsigned int r_type = ELF32_R_TYPE (reloc->r_info); |
| 225 | |
| 226 | if (__builtin_expect (r_type == R_68K_RELATIVE, 0)) |
| 227 | *reloc_addr = map->l_addr + reloc->r_addend; |
| 228 | else |
| 229 | { |
| 230 | const Elf32_Sym *const refsym = sym; |
| 231 | struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version, |
| 232 | r_type); |
| 233 | Elf32_Addr value = SYMBOL_ADDRESS (sym_map, sym, true); |
| 234 | |
| 235 | switch (r_type) |
| 236 | { |
| 237 | case R_68K_GLOB_DAT: |
| 238 | case R_68K_JMP_SLOT: |
| 239 | *reloc_addr = value; |
| 240 | break; |
| 241 | #ifndef RTLD_BOOTSTRAP |
| 242 | case R_68K_COPY: |
| 243 | if (sym == NULL) |
| 244 | /* This can happen in trace mode if an object could not be |
| 245 | found. */ |
| 246 | break; |
| 247 | if (sym->st_size > refsym->st_size |
| 248 | || (sym->st_size < refsym->st_size && GLRO(dl_verbose))) |
| 249 | { |
| 250 | const char *strtab; |
| 251 | |
| 252 | strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
| 253 | _dl_error_printf ("\ |
| 254 | %s: Symbol `%s' has different size in shared object, consider re-linking\n", |
| 255 | RTLD_PROGNAME, strtab + refsym->st_name); |
| 256 | } |
| 257 | memcpy (reloc_addr_arg, (void *) value, |
| 258 | MIN (sym->st_size, refsym->st_size)); |
| 259 | break; |
| 260 | case R_68K_8: |
| 261 | *(char *) reloc_addr = value + reloc->r_addend; |
| 262 | break; |
| 263 | case R_68K_16: |
| 264 | *(short *) reloc_addr = value + reloc->r_addend; |
| 265 | break; |
| 266 | case R_68K_32: |
| 267 | *reloc_addr = value + reloc->r_addend; |
| 268 | break; |
| 269 | case R_68K_PC8: |
| 270 | *(char *) reloc_addr |
| 271 | = value + reloc->r_addend - (Elf32_Addr) reloc_addr; |
| 272 | break; |
| 273 | case R_68K_PC16: |
| 274 | *(short *) reloc_addr |
| 275 | = value + reloc->r_addend - (Elf32_Addr) reloc_addr; |
| 276 | break; |
| 277 | case R_68K_PC32: |
| 278 | *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr; |
| 279 | break; |
| 280 | case R_68K_TLS_DTPMOD32: |
| 281 | /* Get the information from the link map returned by the |
| 282 | resolv function. */ |
| 283 | if (sym_map != NULL) |
| 284 | *reloc_addr = sym_map->l_tls_modid; |
| 285 | break; |
| 286 | case R_68K_TLS_DTPREL32: |
| 287 | if (sym != NULL) |
| 288 | *reloc_addr = TLS_DTPREL_VALUE (sym, reloc); |
| 289 | break; |
| 290 | case R_68K_TLS_TPREL32: |
| 291 | if (sym != NULL) |
| 292 | { |
| 293 | CHECK_STATIC_TLS (map, sym_map); |
| 294 | *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc); |
| 295 | } |
| 296 | break; |
| 297 | case R_68K_NONE: /* Alright, Wilbur. */ |
| 298 | break; |
| 299 | #endif /* !RTLD_BOOTSTRAP */ |
| 300 | default: |
| 301 | _dl_reloc_bad_type (map, r_type, 0); |
| 302 | break; |
| 303 | } |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | static inline void __attribute__ ((unused, always_inline)) |
| 308 | elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc, |
| 309 | void *const reloc_addr_arg) |
| 310 | { |
| 311 | Elf32_Addr *const reloc_addr = reloc_addr_arg; |
| 312 | *reloc_addr = l_addr + reloc->r_addend; |
| 313 | } |
| 314 | |
| 315 | static inline void __attribute__ ((unused, always_inline)) |
| 316 | elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[], |
| 317 | Elf32_Addr l_addr, const Elf32_Rela *reloc, |
| 318 | int skip_ifunc) |
| 319 | { |
| 320 | Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); |
| 321 | if (ELF32_R_TYPE (reloc->r_info) == R_68K_JMP_SLOT) |
| 322 | *reloc_addr += l_addr; |
| 323 | else |
| 324 | _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1); |
| 325 | } |
| 326 | |
| 327 | #endif /* RESOLVE_MAP */ |
| 328 |
Warning: This file is not a C or C++ file. It does not have highlighting.