include/hw/elf_ops.h

   1 static void glue(bswap_ehdr, SZ)(struct elfhdr *ehdr)
   2 {
   3     bswap16s(&ehdr->e_type);                    /* Object file type */
   4     bswap16s(&ehdr->e_machine);         /* Architecture */
   5     bswap32s(&ehdr->e_version);         /* Object file version */
   6     bswapSZs(&ehdr->e_entry);           /* Entry point virtual address */
   7     bswapSZs(&ehdr->e_phoff);           /* Program header table file offset */
   8     bswapSZs(&ehdr->e_shoff);           /* Section header table file offset */
   9     bswap32s(&ehdr->e_flags);           /* Processor-specific flags */
  10     bswap16s(&ehdr->e_ehsize);          /* ELF header size in bytes */
  11     bswap16s(&ehdr->e_phentsize);               /* Program header table entry size */
  12     bswap16s(&ehdr->e_phnum);           /* Program header table entry count */
  13     bswap16s(&ehdr->e_shentsize);               /* Section header table entry size */
  14     bswap16s(&ehdr->e_shnum);           /* Section header table entry count */
  15     bswap16s(&ehdr->e_shstrndx);                /* Section header string table index */
  16 }
  17
  18 static void glue(bswap_phdr, SZ)(struct elf_phdr *phdr)
  19 {
  20     bswap32s(&phdr->p_type);                    /* Segment type */
  21     bswapSZs(&phdr->p_offset);          /* Segment file offset */
  22     bswapSZs(&phdr->p_vaddr);           /* Segment virtual address */
  23     bswapSZs(&phdr->p_paddr);           /* Segment physical address */
  24     bswapSZs(&phdr->p_filesz);          /* Segment size in file */
  25     bswapSZs(&phdr->p_memsz);           /* Segment size in memory */
  26     bswap32s(&phdr->p_flags);           /* Segment flags */
  27     bswapSZs(&phdr->p_align);           /* Segment alignment */
  28 }
  29
  30 static void glue(bswap_shdr, SZ)(struct elf_shdr *shdr)
  31 {
  32     bswap32s(&shdr->sh_name);
  33     bswap32s(&shdr->sh_type);
  34     bswapSZs(&shdr->sh_flags);
  35     bswapSZs(&shdr->sh_addr);
  36     bswapSZs(&shdr->sh_offset);
  37     bswapSZs(&shdr->sh_size);
  38     bswap32s(&shdr->sh_link);
  39     bswap32s(&shdr->sh_info);
  40     bswapSZs(&shdr->sh_addralign);
  41     bswapSZs(&shdr->sh_entsize);
  42 }
  43
  44 static void glue(bswap_sym, SZ)(struct elf_sym *sym)
  45 {
  46     bswap32s(&sym->st_name);
  47     bswapSZs(&sym->st_value);
  48     bswapSZs(&sym->st_size);
  49     bswap16s(&sym->st_shndx);
  50 }
  51
  52 static void glue(bswap_rela, SZ)(struct elf_rela *rela)
  53 {
  54     bswapSZs(&rela->r_offset);
  55     bswapSZs(&rela->r_info);
  56     bswapSZs((elf_word *)&rela->r_addend);
  57 }
  58
  59 static struct elf_shdr *glue(find_section, SZ)(struct elf_shdr *shdr_table,
  60                                                int n, int type)
  61 {
  62     int i;
  63     for(i=0;i<n;i++) {
  64         if (shdr_table[i].sh_type == type)
  65             return shdr_table + i;
  66     }
  67     return NULL;
  68 }
  69
  70 static int glue(symfind, SZ)(const void *s0, const void *s1)
  71 {
  72     hwaddr addr = *(hwaddr *)s0;
  73     struct elf_sym *sym = (struct elf_sym *)s1;
  74     int result = 0;
  75     if (addr < sym->st_value) {
  76         result = -1;
  77     } else if (addr >= sym->st_value + sym->st_size) {
  78         result = 1;
  79     }
  80     return result;
  81 }
  82
  83 static const char *glue(lookup_symbol, SZ)(struct syminfo *s,
  84                                            hwaddr orig_addr)
  85 {
  86     struct elf_sym *syms = glue(s->disas_symtab.elf, SZ);
  87     struct elf_sym *sym;
  88
  89     sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms),
  90                   glue(symfind, SZ));
  91     if (sym != NULL) {
  92         return s->disas_strtab + sym->st_name;
  93     }
  94
  95     return "";
  96 }
  97
  98 static int glue(symcmp, SZ)(const void *s0, const void *s1)
  99 {
 100     struct elf_sym *sym0 = (struct elf_sym *)s0;
 101     struct elf_sym *sym1 = (struct elf_sym *)s1;
 102     return (sym0->st_value < sym1->st_value)
 103         ? -1
 104         : ((sym0->st_value > sym1->st_value) ? 1 : 0);
 105 }
 106
 107 static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
 108                                   int clear_lsb, symbol_fn_t sym_cb)
 109 {
 110     struct elf_shdr *symtab, *strtab, *shdr_table = NULL;
 111     struct elf_sym *syms = NULL;
 112     struct syminfo *s;
 113     int nsyms, i;
 114     char *str = NULL;
 115
 116     shdr_table = load_at(fd, ehdr->e_shoff,
 117                          sizeof(struct elf_shdr) * ehdr->e_shnum);
 118     if (!shdr_table)
 119         return -1;
 120
 121     if (must_swab) {
 122         for (i = 0; i < ehdr->e_shnum; i++) {
 123             glue(bswap_shdr, SZ)(shdr_table + i);
 124         }
 125     }
 126
 127     symtab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_SYMTAB);
 128     if (!symtab)
 129         goto fail;
 130     syms = load_at(fd, symtab->sh_offset, symtab->sh_size);
 131     if (!syms)
 132         goto fail;
 133
 134     nsyms = symtab->sh_size / sizeof(struct elf_sym);
 135
 136     /* String table */
 137     if (symtab->sh_link >= ehdr->e_shnum) {
 138         goto fail;
 139     }
 140     strtab = &shdr_table[symtab->sh_link];
 141
 142     str = load_at(fd, strtab->sh_offset, strtab->sh_size);
 143     if (!str) {
 144         goto fail;
 145     }
 146
 147     i = 0;
 148     while (i < nsyms) {
 149         if (must_swab) {
 150             glue(bswap_sym, SZ)(&syms[i]);
 151         }
 152         if (sym_cb) {
 153             sym_cb(str + syms[i].st_name, syms[i].st_info,
 154                    syms[i].st_value, syms[i].st_size);
 155         }
 156         /* We are only interested in function symbols.
 157            Throw everything else away.  */
 158         if (syms[i].st_shndx == SHN_UNDEF ||
 159                 syms[i].st_shndx >= SHN_LORESERVE ||
 160                 ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) {
 161             nsyms--;
 162             if (i < nsyms) {
 163                 syms[i] = syms[nsyms];
 164             }
 165             continue;
 166         }
 167         if (clear_lsb) {
 168             /* The bottom address bit marks a Thumb or MIPS16 symbol.  */
 169             syms[i].st_value &= ~(glue(glue(Elf, SZ), _Addr))1;
 170         }
 171         i++;
 172     }
 173     syms = g_realloc(syms, nsyms * sizeof(*syms));
 174
 175     qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
 176     for (i = 0; i < nsyms - 1; i++) {
 177         if (syms[i].st_size == 0) {
 178             syms[i].st_size = syms[i + 1].st_value - syms[i].st_value;
 179         }
 180     }
 181
 182     /* Commit */
 183     s = g_malloc0(sizeof(*s));
 184     s->lookup_symbol = glue(lookup_symbol, SZ);
 185     glue(s->disas_symtab.elf, SZ) = syms;
 186     s->disas_num_syms = nsyms;
 187     s->disas_strtab = str;
 188     s->next = syminfos;
 189     syminfos = s;
 190     g_free(shdr_table);
 191     return 0;
 192  fail:
 193     g_free(syms);
 194     g_free(str);
 195     g_free(shdr_table);
 196     return -1;
 197 }
 198
 199 static int glue(elf_reloc, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
 200                                uint64_t (*translate_fn)(void *, uint64_t),
 201                                void *translate_opaque, uint8_t *data,
 202                                struct elf_phdr *ph, int elf_machine)
 203 {
 204     struct elf_shdr *reltab, *shdr_table = NULL;
 205     struct elf_rela *rels = NULL;
 206     int nrels, i, ret = -1;
 207     elf_word wordval;
 208     void *addr;
 209
 210     shdr_table = load_at(fd, ehdr->e_shoff,
 211                          sizeof(struct elf_shdr) * ehdr->e_shnum);
 212     if (!shdr_table) {
 213         return -1;
 214     }
 215     if (must_swab) {
 216         for (i = 0; i < ehdr->e_shnum; i++) {
 217             glue(bswap_shdr, SZ)(&shdr_table[i]);
 218         }
 219     }
 220
 221     reltab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_RELA);
 222     if (!reltab) {
 223         goto fail;
 224     }
 225     rels = load_at(fd, reltab->sh_offset, reltab->sh_size);
 226     if (!rels) {
 227         goto fail;
 228     }
 229     nrels = reltab->sh_size / sizeof(struct elf_rela);
 230
 231     for (i = 0; i < nrels; i++) {
 232         if (must_swab) {
 233             glue(bswap_rela, SZ)(&rels[i]);
 234         }
 235         if (rels[i].r_offset < ph->p_vaddr ||
 236             rels[i].r_offset >= ph->p_vaddr + ph->p_filesz) {
 237             continue;
 238         }
 239         addr = &data[rels[i].r_offset - ph->p_vaddr];
 240         switch (elf_machine) {
 241         case EM_S390:
 242             switch (rels[i].r_info) {
 243             case R_390_RELATIVE:
 244                 wordval = *(elf_word *)addr;
 245                 if (must_swab) {
 246                     bswapSZs(&wordval);
 247                 }
 248                 wordval = translate_fn(translate_opaque, wordval);
 249                 if (must_swab) {
 250                     bswapSZs(&wordval);
 251                 }
 252                 *(elf_word *)addr = wordval;
 253                 break;
 254             default:
 255                 fprintf(stderr, "Unsupported relocation type %i!\n",
 256                         (int)rels[i].r_info);
 257             }
 258         }
 259     }
 260
 261     ret = 0;
 262 fail:
 263     g_free(rels);
 264     g_free(shdr_table);
 265     return ret;
 266 }
 267
 268 static int glue(load_elf, SZ)(const char *name, int fd,
 269                               uint64_t (*elf_note_fn)(void *, void *, bool),
 270                               uint64_t (*translate_fn)(void *, uint64_t),
 271                               void *translate_opaque,
 272                               int must_swab, uint64_t *pentry,
 273                               uint64_t *lowaddr, uint64_t *highaddr,
 274                               int elf_machine, int clear_lsb, int data_swab,
 275                               AddressSpace *as, bool load_rom,
 276                               symbol_fn_t sym_cb)
 277 {
 278     struct elfhdr ehdr;
 279     struct elf_phdr *phdr = NULL, *ph;
 280     int size, i, total_size;
 281     elf_word mem_size, file_size;
 282     uint64_t addr, low = (uint64_t)-1, high = 0;
 283     uint8_t *data = NULL;
 284     char label[128];
 285     int ret = ELF_LOAD_FAILED;
 286
 287     if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
 288         goto fail;
 289     if (must_swab) {
 290         glue(bswap_ehdr, SZ)(&ehdr);
 291     }
 292
 293     if (elf_machine <= EM_NONE) {
 294         /* The caller didn't specify an ARCH, we can figure it out */
 295         elf_machine = ehdr.e_machine;
 296     }
 297
 298     switch (elf_machine) {
 299         case EM_PPC64:
 300             if (ehdr.e_machine != EM_PPC64) {
 301                 if (ehdr.e_machine != EM_PPC) {
 302                     ret = ELF_LOAD_WRONG_ARCH;
 303                     goto fail;
 304                 }
 305             }
 306             break;
 307         case EM_X86_64:
 308             if (ehdr.e_machine != EM_X86_64) {
 309                 if (ehdr.e_machine != EM_386) {
 310                     ret = ELF_LOAD_WRONG_ARCH;
 311                     goto fail;
 312                 }
 313             }
 314             break;
 315         case EM_MICROBLAZE:
 316             if (ehdr.e_machine != EM_MICROBLAZE) {
 317                 if (ehdr.e_machine != EM_MICROBLAZE_OLD) {
 318                     ret = ELF_LOAD_WRONG_ARCH;
 319                     goto fail;
 320                 }
 321             }
 322             break;
 323         case EM_MOXIE:
 324             if (ehdr.e_machine != EM_MOXIE) {
 325                 if (ehdr.e_machine != EM_MOXIE_OLD) {
 326                     ret = ELF_LOAD_WRONG_ARCH;
 327                     goto fail;
 328                 }
 329             }
 330             break;
 331         case EM_MIPS:
 332         case EM_NANOMIPS:
 333             if ((ehdr.e_machine != EM_MIPS) &&
 334                 (ehdr.e_machine != EM_NANOMIPS)) {
 335                 ret = ELF_LOAD_WRONG_ARCH;
 336                 goto fail;
 337             }
 338             break;
 339         default:
 340             if (elf_machine != ehdr.e_machine) {
 341                 ret = ELF_LOAD_WRONG_ARCH;
 342                 goto fail;
 343             }
 344     }
 345
 346     if (pentry)
 347         *pentry = (uint64_t)(elf_sword)ehdr.e_entry;
 348
 349     glue(load_symbols, SZ)(&ehdr, fd, must_swab, clear_lsb, sym_cb);
 350
 351     size = ehdr.e_phnum * sizeof(phdr[0]);
 352     if (lseek(fd, ehdr.e_phoff, SEEK_SET) != ehdr.e_phoff) {
 353         goto fail;
 354     }
 355     phdr = g_malloc0(size);
 356     if (!phdr)
 357         goto fail;
 358     if (read(fd, phdr, size) != size)
 359         goto fail;
 360     if (must_swab) {
 361         for(i = 0; i < ehdr.e_phnum; i++) {
 362             ph = &phdr[i];
 363             glue(bswap_phdr, SZ)(ph);
 364         }
 365     }
 366
 367     total_size = 0;
 368     for(i = 0; i < ehdr.e_phnum; i++) {
 369         ph = &phdr[i];
 370         if (ph->p_type == PT_LOAD) {
 371             mem_size = ph->p_memsz; /* Size of the ROM */
 372             file_size = ph->p_filesz; /* Size of the allocated data */
 373             data = g_malloc0(file_size);
 374             if (ph->p_filesz > 0) {
 375                 if (lseek(fd, ph->p_offset, SEEK_SET) < 0) {
 376                     goto fail;
 377                 }
 378                 if (read(fd, data, file_size) != file_size) {
 379                     goto fail;
 380                 }
 381             }
 382
 383             /* The ELF spec is somewhat vague about the purpose of the
 384              * physical address field. One common use in the embedded world
 385              * is that physical address field specifies the load address
 386              * and the virtual address field specifies the execution address.
 387              * Segments are packed into ROM or flash, and the relocation
 388              * and zero-initialization of data is done at runtime. This
 389              * means that the memsz header represents the runtime size of the
 390              * segment, but the filesz represents the loadtime size. If
 391              * we try to honour the memsz value for an ELF file like this
 392              * we will end up with overlapping segments (which the
 393              * loader.c code will later reject).
 394              * We support ELF files using this scheme by by checking whether
 395              * paddr + memsz for this segment would overlap with any other
 396              * segment. If so, then we assume it's using this scheme and
 397              * truncate the loaded segment to the filesz size.
 398              * If the segment considered as being memsz size doesn't overlap
 399              * then we use memsz for the segment length, to handle ELF files
 400              * which assume that the loader will do the zero-initialization.
 401              */
 402             if (mem_size > file_size) {
 403                 /* If this segment's zero-init portion overlaps another
 404                  * segment's data or zero-init portion, then truncate this one.
 405                  * Invalid ELF files where the segments overlap even when
 406                  * only file_size bytes are loaded will be rejected by
 407                  * the ROM overlap check in loader.c, so we don't try to
 408                  * explicitly detect those here.
 409                  */
 410                 int j;
 411                 elf_word zero_start = ph->p_paddr + file_size;
 412                 elf_word zero_end = ph->p_paddr + mem_size;
 413
 414                 for (j = 0; j < ehdr.e_phnum; j++) {
 415                     struct elf_phdr *jph = &phdr[j];
 416
 417                     if (i != j && jph->p_type == PT_LOAD) {
 418                         elf_word other_start = jph->p_paddr;
 419                         elf_word other_end = jph->p_paddr + jph->p_memsz;
 420
 421                         if (!(other_start >= zero_end ||
 422                               zero_start >= other_end)) {
 423                             mem_size = file_size;
 424                             break;
 425                         }
 426                     }
 427                 }
 428             }
 429
 430             /* address_offset is hack for kernel images that are
 431                linked at the wrong physical address.  */
 432             if (translate_fn) {
 433                 addr = translate_fn(translate_opaque, ph->p_paddr);
 434                 glue(elf_reloc, SZ)(&ehdr, fd, must_swab,  translate_fn,
 435                                     translate_opaque, data, ph, elf_machine);
 436             } else {
 437                 addr = ph->p_paddr;
 438             }
 439
 440             if (data_swab) {
 441                 int j;
 442                 for (j = 0; j < file_size; j += (1 << data_swab)) {
 443                     uint8_t *dp = data + j;
 444                     switch (data_swab) {
 445                     case (1):
 446                         *(uint16_t *)dp = bswap16(*(uint16_t *)dp);
 447                         break;
 448                     case (2):
 449                         *(uint32_t *)dp = bswap32(*(uint32_t *)dp);
 450                         break;
 451                     case (3):
 452                         *(uint64_t *)dp = bswap64(*(uint64_t *)dp);
 453                         break;
 454                     default:
 455                         g_assert_not_reached();
 456                     }
 457                 }
 458             }
 459
 460             /* the entry pointer in the ELF header is a virtual
 461              * address, if the text segments paddr and vaddr differ
 462              * we need to adjust the entry */
 463             if (pentry && !translate_fn &&
 464                     ph->p_vaddr != ph->p_paddr &&
 465                     ehdr.e_entry >= ph->p_vaddr &&
 466                     ehdr.e_entry < ph->p_vaddr + ph->p_filesz &&
 467                     ph->p_flags & PF_X) {
 468                 *pentry = ehdr.e_entry - ph->p_vaddr + ph->p_paddr;
 469             }
 470
 471             if (mem_size == 0) {
 472                 /* Some ELF files really do have segments of zero size;
 473                  * just ignore them rather than trying to create empty
 474                  * ROM blobs, because the zero-length blob can falsely
 475                  * trigger the overlapping-ROM-blobs check.
 476                  */
 477                 g_free(data);
 478             } else {
 479                 if (load_rom) {
 480                     snprintf(label, sizeof(label), "phdr #%d: %s", i, name);
 481
 482                     /* rom_add_elf_program() seize the ownership of 'data' */
 483                     rom_add_elf_program(label, data, file_size, mem_size,
 484                                         addr, as);
 485                 } else {
 486                     address_space_write(as ? as : &address_space_memory,
 487                                         addr, MEMTXATTRS_UNSPECIFIED,
 488                                         data, file_size);
 489                     g_free(data);
 490                 }
 491             }
 492
 493             total_size += mem_size;
 494             if (addr < low)
 495                 low = addr;
 496             if ((addr + mem_size) > high)
 497                 high = addr + mem_size;
 498
 499             data = NULL;
 500         }
 501     }
 502
 503     g_free(phdr);
 504     if (lowaddr)
 505         *lowaddr = (uint64_t)(elf_sword)low;
 506     if (highaddr)
 507         *highaddr = (uint64_t)(elf_sword)high;
 508     return total_size;
 509  fail:
 510     g_free(data);
 511     g_free(phdr);
 512     return ret;
 513 }