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| 1 | /* Machine-dependent ELF dynamic relocation inline functions. SH version. |
|---|---|
| 2 | Copyright (C) 1999-2022 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 "SH" |
| 23 | |
| 24 | #include <sys/param.h> |
| 25 | #include <sysdep.h> |
| 26 | #include <assert.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 __attribute__ ((unused)) |
| 32 | elf_machine_matches_host (const Elf32_Ehdr *ehdr) |
| 33 | { |
| 34 | return ehdr->e_machine == EM_SH; |
| 35 | } |
| 36 | |
| 37 | |
| 38 | /* Return the link-time address of _DYNAMIC. Conveniently, this is the |
| 39 | first element of the GOT. This must be inlined in a function which |
| 40 | uses global data. */ |
| 41 | static inline Elf32_Addr __attribute__ ((unused)) |
| 42 | elf_machine_dynamic (void) |
| 43 | { |
| 44 | register Elf32_Addr *got; |
| 45 | asm ("mov r12,%0" :"=r" (got)); |
| 46 | return *got; |
| 47 | } |
| 48 | |
| 49 | |
| 50 | /* Return the run-time load address of the shared object. */ |
| 51 | static inline Elf32_Addr __attribute__ ((unused)) |
| 52 | elf_machine_load_address (void) |
| 53 | { |
| 54 | Elf32_Addr addr; |
| 55 | asm ("mov.l 1f,r0\n\ |
| 56 | mov.l 3f,r2\n\ |
| 57 | add r12,r2\n\ |
| 58 | mov.l @(r0,r12),r0\n\ |
| 59 | bra 2f\n\ |
| 60 | sub r0,r2\n\ |
| 61 | .align 2\n\ |
| 62 | 1: .long _dl_start@GOT\n\ |
| 63 | 3: .long _dl_start@GOTOFF\n\ |
| 64 | 2: mov r2,%0" |
| 65 | : "=r" (addr) : : "r0", "r1", "r2"); |
| 66 | return addr; |
| 67 | } |
| 68 | |
| 69 | |
| 70 | /* Set up the loaded object described by L so its unrelocated PLT |
| 71 | entries will jump to the on-demand fixup code in dl-runtime.c. */ |
| 72 | |
| 73 | static inline int __attribute__ ((unused, always_inline)) |
| 74 | elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[], |
| 75 | int lazy, int profile) |
| 76 | { |
| 77 | Elf32_Addr *got; |
| 78 | extern void _dl_runtime_resolve (Elf32_Word); |
| 79 | extern void _dl_runtime_profile (Elf32_Word); |
| 80 | |
| 81 | if (l->l_info[DT_JMPREL] && lazy) |
| 82 | { |
| 83 | /* The GOT entries for functions in the PLT have not yet been filled |
| 84 | in. Their initial contents will arrange when called to load an |
| 85 | offset into the .rela.plt section and _GLOBAL_OFFSET_TABLE_[1], |
| 86 | and then jump to _GLOBAL_OFFSET_TABLE[2]. */ |
| 87 | got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); |
| 88 | /* If a library is prelinked but we have to relocate anyway, |
| 89 | we have to be able to undo the prelinking of .got.plt. |
| 90 | The prelinker saved us here address of .plt + 36. */ |
| 91 | if (got[1]) |
| 92 | { |
| 93 | l->l_mach.plt = got[1] + l->l_addr; |
| 94 | l->l_mach.gotplt = (Elf32_Addr) &got[3]; |
| 95 | } |
| 96 | got[1] = (Elf32_Addr) l; /* Identify this shared object. */ |
| 97 | |
| 98 | /* The got[2] entry contains the address of a function which gets |
| 99 | called to get the address of a so far unresolved function and |
| 100 | jump to it. The profiling extension of the dynamic linker allows |
| 101 | to intercept the calls to collect information. In this case we |
| 102 | don't store the address in the GOT so that all future calls also |
| 103 | end in this function. */ |
| 104 | if (profile) |
| 105 | { |
| 106 | got[2] = (Elf32_Addr) &_dl_runtime_profile; |
| 107 | /* Say that we really want profiling and the timers are started. */ |
| 108 | if (GLRO(dl_profile) != NULL |
| 109 | && _dl_name_match_p (GLRO(dl_profile), l)) |
| 110 | GL(dl_profile_map) = l; |
| 111 | } |
| 112 | else |
| 113 | /* This function will get called to fix up the GOT entry indicated by |
| 114 | the offset on the stack, and then jump to the resolved address. */ |
| 115 | got[2] = (Elf32_Addr) &_dl_runtime_resolve; |
| 116 | } |
| 117 | return lazy; |
| 118 | } |
| 119 | |
| 120 | #define ELF_MACHINE_RUNTIME_FIXUP_ARGS int plt_type |
| 121 | #define ELF_MACHINE_RUNTIME_FIXUP_PARAMS plt_type |
| 122 | |
| 123 | /* Mask identifying addresses reserved for the user program, |
| 124 | where the dynamic linker should not map anything. */ |
| 125 | #define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL |
| 126 | |
| 127 | /* Initial entry point code for the dynamic linker. |
| 128 | The C function `_dl_start' is the real entry point; |
| 129 | its return value is the user program's entry point. */ |
| 130 | |
| 131 | #define RTLD_START asm ("\ |
| 132 | .text\n\ |
| 133 | .globl _start\n\ |
| 134 | .globl _dl_start_user\n\ |
| 135 | _start:\n\ |
| 136 | mov r15,r4\n\ |
| 137 | mov.l .L_dl_start,r1\n\ |
| 138 | mova .L_dl_start,r0\n\ |
| 139 | add r1,r0\n\ |
| 140 | jsr @r0\n\ |
| 141 | nop\n\ |
| 142 | _dl_start_user:\n\ |
| 143 | ! Save the user entry point address in r8.\n\ |
| 144 | mov r0,r8\n\ |
| 145 | ! Point r12 at the GOT.\n\ |
| 146 | mov.l 1f,r12\n\ |
| 147 | mova 1f,r0\n\ |
| 148 | bra 2f\n\ |
| 149 | add r0,r12\n\ |
| 150 | .align 2\n\ |
| 151 | 1: .long _GLOBAL_OFFSET_TABLE_\n\ |
| 152 | 2: ! See if we were run as a command with the executable file\n\ |
| 153 | ! name as an extra leading argument.\n\ |
| 154 | mov.l .L_dl_skip_args,r0\n\ |
| 155 | mov.l @(r0,r12),r0\n\ |
| 156 | mov.l @r0,r0\n\ |
| 157 | ! Get the original argument count.\n\ |
| 158 | mov.l @r15,r5\n\ |
| 159 | ! Subtract _dl_skip_args from it.\n\ |
| 160 | sub r0,r5\n\ |
| 161 | ! Adjust the stack pointer to skip _dl_skip_args words.\n\ |
| 162 | shll2 r0\n\ |
| 163 | add r0,r15\n\ |
| 164 | ! Store back the modified argument count.\n\ |
| 165 | mov.l r5,@r15\n\ |
| 166 | ! Compute argv address and envp.\n\ |
| 167 | mov r15,r6\n\ |
| 168 | add #4,r6\n\ |
| 169 | mov r5,r7\n\ |
| 170 | shll2 r7\n\ |
| 171 | add r15,r7\n\ |
| 172 | add #8,r7\n\ |
| 173 | mov.l .L_dl_loaded,r0\n\ |
| 174 | mov.l @(r0,r12),r0\n\ |
| 175 | mov.l @r0,r4\n\ |
| 176 | ! Call _dl_init.\n\ |
| 177 | mov.l .L_dl_init,r1\n\ |
| 178 | mova .L_dl_init,r0\n\ |
| 179 | add r1,r0\n\ |
| 180 | jsr @r0\n\ |
| 181 | nop\n\ |
| 182 | 1: ! Pass our finalizer function to the user in r4, as per ELF ABI.\n\ |
| 183 | mov.l .L_dl_fini,r0\n\ |
| 184 | mov.l @(r0,r12),r4\n\ |
| 185 | ! Jump to the user's entry point.\n\ |
| 186 | jmp @r8\n\ |
| 187 | nop\n\ |
| 188 | .align 2\n\ |
| 189 | .L_dl_start:\n\ |
| 190 | .long _dl_start@PLT\n\ |
| 191 | .L_dl_skip_args:\n\ |
| 192 | .long _dl_skip_args@GOT\n\ |
| 193 | .L_dl_init:\n\ |
| 194 | .long _dl_init@PLT\n\ |
| 195 | .L_dl_loaded:\n\ |
| 196 | .long _rtld_local@GOT\n\ |
| 197 | .L_dl_fini:\n\ |
| 198 | .long _dl_fini@GOT\n\ |
| 199 | .type __fpscr_values,@object\n\ |
| 200 | .global __fpscr_values\n\ |
| 201 | __fpscr_values:\n\ |
| 202 | .long 0\n\ |
| 203 | .long 0x80000\n\ |
| 204 | .weak __fpscr_values\n\ |
| 205 | .previous\n\ |
| 206 | "); |
| 207 | |
| 208 | /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or |
| 209 | TLS variable, so undefined references should not be allowed to |
| 210 | define the value. |
| 211 | ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one |
| 212 | of the main executable's symbols, as for a COPY reloc. */ |
| 213 | #define elf_machine_type_class(type) \ |
| 214 | ((((type) == R_SH_JMP_SLOT || (type) == R_SH_TLS_DTPMOD32 \ |
| 215 | || (type) == R_SH_TLS_DTPOFF32 || (type) == R_SH_TLS_TPOFF32) \ |
| 216 | * ELF_RTYPE_CLASS_PLT) \ |
| 217 | | (((type) == R_SH_COPY) * ELF_RTYPE_CLASS_COPY)) |
| 218 | |
| 219 | /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ |
| 220 | #define ELF_MACHINE_JMP_SLOT R_SH_JMP_SLOT |
| 221 | |
| 222 | /* We define an initialization functions. This is called very early in |
| 223 | _dl_sysdep_start. */ |
| 224 | #define DL_PLATFORM_INIT dl_platform_init () |
| 225 | |
| 226 | static inline void __attribute__ ((unused)) |
| 227 | dl_platform_init (void) |
| 228 | { |
| 229 | if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0') |
| 230 | /* Avoid an empty string which would disturb us. */ |
| 231 | GLRO(dl_platform) = NULL; |
| 232 | } |
| 233 | |
| 234 | static inline Elf32_Addr |
| 235 | elf_machine_fixup_plt (struct link_map *map, lookup_t t, |
| 236 | const ElfW(Sym) *refsym, const ElfW(Sym) *sym, |
| 237 | const Elf32_Rela *reloc, |
| 238 | Elf32_Addr *reloc_addr, Elf32_Addr value) |
| 239 | { |
| 240 | return *reloc_addr = value; |
| 241 | } |
| 242 | |
| 243 | /* Return the final value of a plt relocation. */ |
| 244 | static inline Elf32_Addr |
| 245 | elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc, |
| 246 | Elf32_Addr value) |
| 247 | { |
| 248 | return value + reloc->r_addend; |
| 249 | } |
| 250 | |
| 251 | #define ARCH_LA_PLTENTER sh_gnu_pltenter |
| 252 | #define ARCH_LA_PLTEXIT sh_gnu_pltexit |
| 253 | |
| 254 | #endif /* !dl_machine_h */ |
| 255 | |
| 256 | #ifdef RESOLVE_MAP |
| 257 | |
| 258 | /* Perform the relocation specified by RELOC and SYM (which is fully resolved). |
| 259 | MAP is the object containing the reloc. */ |
| 260 | |
| 261 | static inline void |
| 262 | __attribute ((always_inline)) |
| 263 | elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], |
| 264 | const Elf32_Rela *reloc, const Elf32_Sym *sym, |
| 265 | const struct r_found_version *version, |
| 266 | void *const reloc_addr_arg, int skip_ifunc) |
| 267 | { |
| 268 | Elf32_Addr *const reloc_addr = reloc_addr_arg; |
| 269 | const unsigned int r_type = ELF32_R_TYPE (reloc->r_info); |
| 270 | Elf32_Addr value; |
| 271 | |
| 272 | #define COPY_UNALIGNED_WORD(swp, twp, align) \ |
| 273 | { \ |
| 274 | void *__s = (swp), *__t = (twp); \ |
| 275 | unsigned char *__s1 = __s, *__t1 = __t; \ |
| 276 | unsigned short *__s2 = __s, *__t2 = __t; \ |
| 277 | unsigned long *__s4 = __s, *__t4 = __t; \ |
| 278 | switch ((align)) \ |
| 279 | { \ |
| 280 | case 0: \ |
| 281 | *__t4 = *__s4; \ |
| 282 | break; \ |
| 283 | case 2: \ |
| 284 | *__t2++ = *__s2++; \ |
| 285 | *__t2 = *__s2; \ |
| 286 | break; \ |
| 287 | default: \ |
| 288 | *__t1++ = *__s1++; \ |
| 289 | *__t1++ = *__s1++; \ |
| 290 | *__t1++ = *__s1++; \ |
| 291 | *__t1 = *__s1; \ |
| 292 | break; \ |
| 293 | } \ |
| 294 | } |
| 295 | |
| 296 | if (__glibc_unlikely (r_type == R_SH_RELATIVE)) |
| 297 | { |
| 298 | #ifndef RTLD_BOOTSTRAP |
| 299 | if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */ |
| 300 | #endif |
| 301 | { |
| 302 | if (reloc->r_addend) |
| 303 | value = map->l_addr + reloc->r_addend; |
| 304 | else |
| 305 | { |
| 306 | COPY_UNALIGNED_WORD (reloc_addr_arg, &value, |
| 307 | (int) reloc_addr_arg & 3); |
| 308 | value += map->l_addr; |
| 309 | } |
| 310 | COPY_UNALIGNED_WORD (&value, reloc_addr_arg, |
| 311 | (int) reloc_addr_arg & 3); |
| 312 | } |
| 313 | } |
| 314 | #ifndef RTLD_BOOTSTRAP |
| 315 | else if (__glibc_unlikely (r_type == R_SH_NONE)) |
| 316 | return; |
| 317 | #endif |
| 318 | else |
| 319 | { |
| 320 | const Elf32_Sym *const refsym = sym; |
| 321 | struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version, |
| 322 | r_type); |
| 323 | |
| 324 | value = SYMBOL_ADDRESS (sym_map, sym, true); |
| 325 | value += reloc->r_addend; |
| 326 | |
| 327 | switch (r_type) |
| 328 | { |
| 329 | case R_SH_COPY: |
| 330 | if (sym == NULL) |
| 331 | /* This can happen in trace mode if an object could not be |
| 332 | found. */ |
| 333 | break; |
| 334 | if (sym->st_size > refsym->st_size |
| 335 | || (sym->st_size < refsym->st_size && GLRO(dl_verbose))) |
| 336 | { |
| 337 | const char *strtab; |
| 338 | |
| 339 | strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]); |
| 340 | _dl_error_printf ("\ |
| 341 | %s: Symbol `%s' has different size in shared object, consider re-linking\n", |
| 342 | RTLD_PROGNAME, strtab + refsym->st_name); |
| 343 | } |
| 344 | memcpy (reloc_addr_arg, (void *) value, |
| 345 | MIN (sym->st_size, refsym->st_size)); |
| 346 | break; |
| 347 | case R_SH_GLOB_DAT: |
| 348 | case R_SH_JMP_SLOT: |
| 349 | /* These addresses are always aligned. */ |
| 350 | *reloc_addr = value; |
| 351 | break; |
| 352 | /* XXX Remove TLS relocations which are not needed. */ |
| 353 | case R_SH_TLS_DTPMOD32: |
| 354 | #ifdef RTLD_BOOTSTRAP |
| 355 | /* During startup the dynamic linker is always the module |
| 356 | with index 1. |
| 357 | XXX If this relocation is necessary move before RESOLVE |
| 358 | call. */ |
| 359 | *reloc_addr = 1; |
| 360 | #else |
| 361 | /* Get the information from the link map returned by the |
| 362 | resolv function. */ |
| 363 | if (sym_map != NULL) |
| 364 | *reloc_addr = sym_map->l_tls_modid; |
| 365 | #endif |
| 366 | break; |
| 367 | case R_SH_TLS_DTPOFF32: |
| 368 | #ifndef RTLD_BOOTSTRAP |
| 369 | /* During relocation all TLS symbols are defined and used. |
| 370 | Therefore the offset is already correct. */ |
| 371 | if (sym != NULL) |
| 372 | *reloc_addr = sym->st_value; |
| 373 | #endif |
| 374 | break; |
| 375 | case R_SH_TLS_TPOFF32: |
| 376 | /* The offset is positive, afterward from the thread pointer. */ |
| 377 | #ifdef RTLD_BOOTSTRAP |
| 378 | *reloc_addr = map->l_tls_offset + sym->st_value + reloc->r_addend; |
| 379 | #else |
| 380 | /* We know the offset of object the symbol is contained in. |
| 381 | It is a positive value which will be added to the thread |
| 382 | pointer. To get the variable position in the TLS block |
| 383 | we add the offset from that of the TLS block. */ |
| 384 | if (sym != NULL) |
| 385 | { |
| 386 | CHECK_STATIC_TLS (map, sym_map); |
| 387 | *reloc_addr = sym_map->l_tls_offset + sym->st_value |
| 388 | + reloc->r_addend; |
| 389 | } |
| 390 | #endif |
| 391 | break; |
| 392 | case R_SH_DIR32: |
| 393 | { |
| 394 | #if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP |
| 395 | /* This is defined in rtld.c, but nowhere in the static |
| 396 | libc.a; make the reference weak so static programs can |
| 397 | still link. This declaration cannot be done when |
| 398 | compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP) because |
| 399 | rtld.c contains the common defn for _dl_rtld_map, which |
| 400 | is incompatible with a weak decl in the same file. */ |
| 401 | # ifndef SHARED |
| 402 | weak_extern (_dl_rtld_map); |
| 403 | # endif |
| 404 | if (map == &GL(dl_rtld_map)) |
| 405 | /* Undo the relocation done here during bootstrapping. |
| 406 | Now we will relocate it anew, possibly using a |
| 407 | binding found in the user program or a loaded library |
| 408 | rather than the dynamic linker's built-in definitions |
| 409 | used while loading those libraries. */ |
| 410 | value -= SYMBOL_ADDRESS (map, refsym, true) + reloc->r_addend; |
| 411 | #endif |
| 412 | COPY_UNALIGNED_WORD (&value, reloc_addr_arg, |
| 413 | (int) reloc_addr_arg & 3); |
| 414 | break; |
| 415 | } |
| 416 | case R_SH_REL32: |
| 417 | value = (value - (Elf32_Addr) reloc_addr); |
| 418 | COPY_UNALIGNED_WORD (&value, reloc_addr_arg, |
| 419 | (int) reloc_addr_arg & 3); |
| 420 | break; |
| 421 | default: |
| 422 | _dl_reloc_bad_type (map, r_type, 0); |
| 423 | break; |
| 424 | } |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | static inline void |
| 429 | __attribute__ ((always_inline)) |
| 430 | elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc, |
| 431 | void *const reloc_addr_arg) |
| 432 | { |
| 433 | Elf32_Addr value; |
| 434 | |
| 435 | if (reloc->r_addend) |
| 436 | value = l_addr + reloc->r_addend; |
| 437 | else |
| 438 | { |
| 439 | COPY_UNALIGNED_WORD (reloc_addr_arg, &value, (int) reloc_addr_arg & 3); |
| 440 | value += l_addr; |
| 441 | } |
| 442 | COPY_UNALIGNED_WORD (&value, reloc_addr_arg, (int) reloc_addr_arg & 3); |
| 443 | |
| 444 | #undef COPY_UNALIGNED_WORD |
| 445 | } |
| 446 | |
| 447 | static inline void |
| 448 | __attribute__ ((always_inline)) |
| 449 | elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[], |
| 450 | Elf32_Addr l_addr, const Elf32_Rela *reloc, |
| 451 | int skip_ifunc) |
| 452 | { |
| 453 | Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); |
| 454 | /* Check for unexpected PLT reloc type. */ |
| 455 | if (ELF32_R_TYPE (reloc->r_info) == R_SH_JMP_SLOT) |
| 456 | { |
| 457 | if (__builtin_expect (map->l_mach.plt, 0) == 0) |
| 458 | *reloc_addr += l_addr; |
| 459 | else |
| 460 | *reloc_addr = |
| 461 | map->l_mach.plt |
| 462 | + (((Elf32_Addr) reloc_addr) - map->l_mach.gotplt) * 7; |
| 463 | } |
| 464 | else |
| 465 | _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1); |
| 466 | } |
| 467 | |
| 468 | #endif /* RESOLVE_MAP */ |
| 469 |
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