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0001 // SPDX-License-Identifier: GPL-2.0
0002 /* This is included from relocs_32/64.c */
0003 
0004 #define ElfW(type)      _ElfW(ELF_BITS, type)
0005 #define _ElfW(bits, type)   __ElfW(bits, type)
0006 #define __ElfW(bits, type)  Elf##bits##_##type
0007 
0008 #define Elf_Addr        ElfW(Addr)
0009 #define Elf_Ehdr        ElfW(Ehdr)
0010 #define Elf_Phdr        ElfW(Phdr)
0011 #define Elf_Shdr        ElfW(Shdr)
0012 #define Elf_Sym         ElfW(Sym)
0013 
0014 static Elf_Ehdr     ehdr;
0015 static unsigned long    shnum;
0016 static unsigned int shstrndx;
0017 static unsigned int shsymtabndx;
0018 static unsigned int shxsymtabndx;
0019 
0020 static int sym_index(Elf_Sym *sym);
0021 
0022 struct relocs {
0023     uint32_t    *offset;
0024     unsigned long   count;
0025     unsigned long   size;
0026 };
0027 
0028 static struct relocs relocs16;
0029 static struct relocs relocs32;
0030 #if ELF_BITS == 64
0031 static struct relocs relocs32neg;
0032 static struct relocs relocs64;
0033 #define FMT PRIu64
0034 #else
0035 #define FMT PRIu32
0036 #endif
0037 
0038 struct section {
0039     Elf_Shdr       shdr;
0040     struct section *link;
0041     Elf_Sym        *symtab;
0042     Elf32_Word     *xsymtab;
0043     Elf_Rel        *reltab;
0044     char           *strtab;
0045 };
0046 static struct section *secs;
0047 
0048 static const char * const sym_regex_kernel[S_NSYMTYPES] = {
0049 /*
0050  * Following symbols have been audited. There values are constant and do
0051  * not change if bzImage is loaded at a different physical address than
0052  * the address for which it has been compiled. Don't warn user about
0053  * absolute relocations present w.r.t these symbols.
0054  */
0055     [S_ABS] =
0056     "^(xen_irq_disable_direct_reloc$|"
0057     "xen_save_fl_direct_reloc$|"
0058     "VDSO|"
0059     "__crc_)",
0060 
0061 /*
0062  * These symbols are known to be relative, even if the linker marks them
0063  * as absolute (typically defined outside any section in the linker script.)
0064  */
0065     [S_REL] =
0066     "^(__init_(begin|end)|"
0067     "__x86_cpu_dev_(start|end)|"
0068     "(__parainstructions|__alt_instructions)(_end)?|"
0069     "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|"
0070     "__(start|end)_pci_.*|"
0071 #if CONFIG_FW_LOADER
0072     "__(start|end)_builtin_fw|"
0073 #endif
0074     "__(start|stop)___ksymtab(_gpl)?|"
0075     "__(start|stop)___kcrctab(_gpl)?|"
0076     "__(start|stop)___param|"
0077     "__(start|stop)___modver|"
0078     "__(start|stop)___bug_table|"
0079     "__tracedata_(start|end)|"
0080     "__(start|stop)_notes|"
0081     "__end_rodata|"
0082     "__end_rodata_aligned|"
0083     "__initramfs_start|"
0084     "(jiffies|jiffies_64)|"
0085 #if ELF_BITS == 64
0086     "__per_cpu_load|"
0087     "init_per_cpu__.*|"
0088     "__end_rodata_hpage_align|"
0089 #endif
0090     "__vvar_page|"
0091     "_end)$"
0092 };
0093 
0094 
0095 static const char * const sym_regex_realmode[S_NSYMTYPES] = {
0096 /*
0097  * These symbols are known to be relative, even if the linker marks them
0098  * as absolute (typically defined outside any section in the linker script.)
0099  */
0100     [S_REL] =
0101     "^pa_",
0102 
0103 /*
0104  * These are 16-bit segment symbols when compiling 16-bit code.
0105  */
0106     [S_SEG] =
0107     "^real_mode_seg$",
0108 
0109 /*
0110  * These are offsets belonging to segments, as opposed to linear addresses,
0111  * when compiling 16-bit code.
0112  */
0113     [S_LIN] =
0114     "^pa_",
0115 };
0116 
0117 static const char * const *sym_regex;
0118 
0119 static regex_t sym_regex_c[S_NSYMTYPES];
0120 static int is_reloc(enum symtype type, const char *sym_name)
0121 {
0122     return sym_regex[type] &&
0123         !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
0124 }
0125 
0126 static void regex_init(int use_real_mode)
0127 {
0128         char errbuf[128];
0129         int err;
0130     int i;
0131 
0132     if (use_real_mode)
0133         sym_regex = sym_regex_realmode;
0134     else
0135         sym_regex = sym_regex_kernel;
0136 
0137     for (i = 0; i < S_NSYMTYPES; i++) {
0138         if (!sym_regex[i])
0139             continue;
0140 
0141         err = regcomp(&sym_regex_c[i], sym_regex[i],
0142                   REG_EXTENDED|REG_NOSUB);
0143 
0144         if (err) {
0145             regerror(err, &sym_regex_c[i], errbuf, sizeof(errbuf));
0146             die("%s", errbuf);
0147         }
0148         }
0149 }
0150 
0151 static const char *sym_type(unsigned type)
0152 {
0153     static const char *type_name[] = {
0154 #define SYM_TYPE(X) [X] = #X
0155         SYM_TYPE(STT_NOTYPE),
0156         SYM_TYPE(STT_OBJECT),
0157         SYM_TYPE(STT_FUNC),
0158         SYM_TYPE(STT_SECTION),
0159         SYM_TYPE(STT_FILE),
0160         SYM_TYPE(STT_COMMON),
0161         SYM_TYPE(STT_TLS),
0162 #undef SYM_TYPE
0163     };
0164     const char *name = "unknown sym type name";
0165     if (type < ARRAY_SIZE(type_name)) {
0166         name = type_name[type];
0167     }
0168     return name;
0169 }
0170 
0171 static const char *sym_bind(unsigned bind)
0172 {
0173     static const char *bind_name[] = {
0174 #define SYM_BIND(X) [X] = #X
0175         SYM_BIND(STB_LOCAL),
0176         SYM_BIND(STB_GLOBAL),
0177         SYM_BIND(STB_WEAK),
0178 #undef SYM_BIND
0179     };
0180     const char *name = "unknown sym bind name";
0181     if (bind < ARRAY_SIZE(bind_name)) {
0182         name = bind_name[bind];
0183     }
0184     return name;
0185 }
0186 
0187 static const char *sym_visibility(unsigned visibility)
0188 {
0189     static const char *visibility_name[] = {
0190 #define SYM_VISIBILITY(X) [X] = #X
0191         SYM_VISIBILITY(STV_DEFAULT),
0192         SYM_VISIBILITY(STV_INTERNAL),
0193         SYM_VISIBILITY(STV_HIDDEN),
0194         SYM_VISIBILITY(STV_PROTECTED),
0195 #undef SYM_VISIBILITY
0196     };
0197     const char *name = "unknown sym visibility name";
0198     if (visibility < ARRAY_SIZE(visibility_name)) {
0199         name = visibility_name[visibility];
0200     }
0201     return name;
0202 }
0203 
0204 static const char *rel_type(unsigned type)
0205 {
0206     static const char *type_name[] = {
0207 #define REL_TYPE(X) [X] = #X
0208 #if ELF_BITS == 64
0209         REL_TYPE(R_X86_64_NONE),
0210         REL_TYPE(R_X86_64_64),
0211         REL_TYPE(R_X86_64_PC64),
0212         REL_TYPE(R_X86_64_PC32),
0213         REL_TYPE(R_X86_64_GOT32),
0214         REL_TYPE(R_X86_64_PLT32),
0215         REL_TYPE(R_X86_64_COPY),
0216         REL_TYPE(R_X86_64_GLOB_DAT),
0217         REL_TYPE(R_X86_64_JUMP_SLOT),
0218         REL_TYPE(R_X86_64_RELATIVE),
0219         REL_TYPE(R_X86_64_GOTPCREL),
0220         REL_TYPE(R_X86_64_32),
0221         REL_TYPE(R_X86_64_32S),
0222         REL_TYPE(R_X86_64_16),
0223         REL_TYPE(R_X86_64_PC16),
0224         REL_TYPE(R_X86_64_8),
0225         REL_TYPE(R_X86_64_PC8),
0226 #else
0227         REL_TYPE(R_386_NONE),
0228         REL_TYPE(R_386_32),
0229         REL_TYPE(R_386_PC32),
0230         REL_TYPE(R_386_GOT32),
0231         REL_TYPE(R_386_PLT32),
0232         REL_TYPE(R_386_COPY),
0233         REL_TYPE(R_386_GLOB_DAT),
0234         REL_TYPE(R_386_JMP_SLOT),
0235         REL_TYPE(R_386_RELATIVE),
0236         REL_TYPE(R_386_GOTOFF),
0237         REL_TYPE(R_386_GOTPC),
0238         REL_TYPE(R_386_8),
0239         REL_TYPE(R_386_PC8),
0240         REL_TYPE(R_386_16),
0241         REL_TYPE(R_386_PC16),
0242 #endif
0243 #undef REL_TYPE
0244     };
0245     const char *name = "unknown type rel type name";
0246     if (type < ARRAY_SIZE(type_name) && type_name[type]) {
0247         name = type_name[type];
0248     }
0249     return name;
0250 }
0251 
0252 static const char *sec_name(unsigned shndx)
0253 {
0254     const char *sec_strtab;
0255     const char *name;
0256     sec_strtab = secs[shstrndx].strtab;
0257     name = "<noname>";
0258     if (shndx < shnum) {
0259         name = sec_strtab + secs[shndx].shdr.sh_name;
0260     }
0261     else if (shndx == SHN_ABS) {
0262         name = "ABSOLUTE";
0263     }
0264     else if (shndx == SHN_COMMON) {
0265         name = "COMMON";
0266     }
0267     return name;
0268 }
0269 
0270 static const char *sym_name(const char *sym_strtab, Elf_Sym *sym)
0271 {
0272     const char *name;
0273     name = "<noname>";
0274     if (sym->st_name) {
0275         name = sym_strtab + sym->st_name;
0276     }
0277     else {
0278         name = sec_name(sym_index(sym));
0279     }
0280     return name;
0281 }
0282 
0283 static Elf_Sym *sym_lookup(const char *symname)
0284 {
0285     int i;
0286     for (i = 0; i < shnum; i++) {
0287         struct section *sec = &secs[i];
0288         long nsyms;
0289         char *strtab;
0290         Elf_Sym *symtab;
0291         Elf_Sym *sym;
0292 
0293         if (sec->shdr.sh_type != SHT_SYMTAB)
0294             continue;
0295 
0296         nsyms = sec->shdr.sh_size/sizeof(Elf_Sym);
0297         symtab = sec->symtab;
0298         strtab = sec->link->strtab;
0299 
0300         for (sym = symtab; --nsyms >= 0; sym++) {
0301             if (!sym->st_name)
0302                 continue;
0303             if (strcmp(symname, strtab + sym->st_name) == 0)
0304                 return sym;
0305         }
0306     }
0307     return 0;
0308 }
0309 
0310 #if BYTE_ORDER == LITTLE_ENDIAN
0311 #define le16_to_cpu(val) (val)
0312 #define le32_to_cpu(val) (val)
0313 #define le64_to_cpu(val) (val)
0314 #endif
0315 #if BYTE_ORDER == BIG_ENDIAN
0316 #define le16_to_cpu(val) bswap_16(val)
0317 #define le32_to_cpu(val) bswap_32(val)
0318 #define le64_to_cpu(val) bswap_64(val)
0319 #endif
0320 
0321 static uint16_t elf16_to_cpu(uint16_t val)
0322 {
0323     return le16_to_cpu(val);
0324 }
0325 
0326 static uint32_t elf32_to_cpu(uint32_t val)
0327 {
0328     return le32_to_cpu(val);
0329 }
0330 
0331 #define elf_half_to_cpu(x)  elf16_to_cpu(x)
0332 #define elf_word_to_cpu(x)  elf32_to_cpu(x)
0333 
0334 #if ELF_BITS == 64
0335 static uint64_t elf64_to_cpu(uint64_t val)
0336 {
0337         return le64_to_cpu(val);
0338 }
0339 #define elf_addr_to_cpu(x)  elf64_to_cpu(x)
0340 #define elf_off_to_cpu(x)   elf64_to_cpu(x)
0341 #define elf_xword_to_cpu(x) elf64_to_cpu(x)
0342 #else
0343 #define elf_addr_to_cpu(x)  elf32_to_cpu(x)
0344 #define elf_off_to_cpu(x)   elf32_to_cpu(x)
0345 #define elf_xword_to_cpu(x) elf32_to_cpu(x)
0346 #endif
0347 
0348 static int sym_index(Elf_Sym *sym)
0349 {
0350     Elf_Sym *symtab = secs[shsymtabndx].symtab;
0351     Elf32_Word *xsymtab = secs[shxsymtabndx].xsymtab;
0352     unsigned long offset;
0353     int index;
0354 
0355     if (sym->st_shndx != SHN_XINDEX)
0356         return sym->st_shndx;
0357 
0358     /* calculate offset of sym from head of table. */
0359     offset = (unsigned long)sym - (unsigned long)symtab;
0360     index = offset / sizeof(*sym);
0361 
0362     return elf32_to_cpu(xsymtab[index]);
0363 }
0364 
0365 static void read_ehdr(FILE *fp)
0366 {
0367     if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
0368         die("Cannot read ELF header: %s\n",
0369             strerror(errno));
0370     }
0371     if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
0372         die("No ELF magic\n");
0373     }
0374     if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) {
0375         die("Not a %d bit executable\n", ELF_BITS);
0376     }
0377     if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
0378         die("Not a LSB ELF executable\n");
0379     }
0380     if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
0381         die("Unknown ELF version\n");
0382     }
0383     /* Convert the fields to native endian */
0384     ehdr.e_type      = elf_half_to_cpu(ehdr.e_type);
0385     ehdr.e_machine   = elf_half_to_cpu(ehdr.e_machine);
0386     ehdr.e_version   = elf_word_to_cpu(ehdr.e_version);
0387     ehdr.e_entry     = elf_addr_to_cpu(ehdr.e_entry);
0388     ehdr.e_phoff     = elf_off_to_cpu(ehdr.e_phoff);
0389     ehdr.e_shoff     = elf_off_to_cpu(ehdr.e_shoff);
0390     ehdr.e_flags     = elf_word_to_cpu(ehdr.e_flags);
0391     ehdr.e_ehsize    = elf_half_to_cpu(ehdr.e_ehsize);
0392     ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize);
0393     ehdr.e_phnum     = elf_half_to_cpu(ehdr.e_phnum);
0394     ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize);
0395     ehdr.e_shnum     = elf_half_to_cpu(ehdr.e_shnum);
0396     ehdr.e_shstrndx  = elf_half_to_cpu(ehdr.e_shstrndx);
0397 
0398     shnum = ehdr.e_shnum;
0399     shstrndx = ehdr.e_shstrndx;
0400 
0401     if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN))
0402         die("Unsupported ELF header type\n");
0403     if (ehdr.e_machine != ELF_MACHINE)
0404         die("Not for %s\n", ELF_MACHINE_NAME);
0405     if (ehdr.e_version != EV_CURRENT)
0406         die("Unknown ELF version\n");
0407     if (ehdr.e_ehsize != sizeof(Elf_Ehdr))
0408         die("Bad Elf header size\n");
0409     if (ehdr.e_phentsize != sizeof(Elf_Phdr))
0410         die("Bad program header entry\n");
0411     if (ehdr.e_shentsize != sizeof(Elf_Shdr))
0412         die("Bad section header entry\n");
0413 
0414 
0415     if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) {
0416         Elf_Shdr shdr;
0417 
0418         if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0)
0419             die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno));
0420 
0421         if (fread(&shdr, sizeof(shdr), 1, fp) != 1)
0422             die("Cannot read initial ELF section header: %s\n", strerror(errno));
0423 
0424         if (shnum == SHN_UNDEF)
0425             shnum = elf_xword_to_cpu(shdr.sh_size);
0426 
0427         if (shstrndx == SHN_XINDEX)
0428             shstrndx = elf_word_to_cpu(shdr.sh_link);
0429     }
0430 
0431     if (shstrndx >= shnum)
0432         die("String table index out of bounds\n");
0433 }
0434 
0435 static void read_shdrs(FILE *fp)
0436 {
0437     int i;
0438     Elf_Shdr shdr;
0439 
0440     secs = calloc(shnum, sizeof(struct section));
0441     if (!secs) {
0442         die("Unable to allocate %ld section headers\n",
0443             shnum);
0444     }
0445     if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
0446         die("Seek to %" FMT " failed: %s\n",
0447             ehdr.e_shoff, strerror(errno));
0448     }
0449     for (i = 0; i < shnum; i++) {
0450         struct section *sec = &secs[i];
0451         if (fread(&shdr, sizeof(shdr), 1, fp) != 1)
0452             die("Cannot read ELF section headers %d/%ld: %s\n",
0453                 i, shnum, strerror(errno));
0454         sec->shdr.sh_name      = elf_word_to_cpu(shdr.sh_name);
0455         sec->shdr.sh_type      = elf_word_to_cpu(shdr.sh_type);
0456         sec->shdr.sh_flags     = elf_xword_to_cpu(shdr.sh_flags);
0457         sec->shdr.sh_addr      = elf_addr_to_cpu(shdr.sh_addr);
0458         sec->shdr.sh_offset    = elf_off_to_cpu(shdr.sh_offset);
0459         sec->shdr.sh_size      = elf_xword_to_cpu(shdr.sh_size);
0460         sec->shdr.sh_link      = elf_word_to_cpu(shdr.sh_link);
0461         sec->shdr.sh_info      = elf_word_to_cpu(shdr.sh_info);
0462         sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
0463         sec->shdr.sh_entsize   = elf_xword_to_cpu(shdr.sh_entsize);
0464         if (sec->shdr.sh_link < shnum)
0465             sec->link = &secs[sec->shdr.sh_link];
0466     }
0467 
0468 }
0469 
0470 static void read_strtabs(FILE *fp)
0471 {
0472     int i;
0473     for (i = 0; i < shnum; i++) {
0474         struct section *sec = &secs[i];
0475         if (sec->shdr.sh_type != SHT_STRTAB) {
0476             continue;
0477         }
0478         sec->strtab = malloc(sec->shdr.sh_size);
0479         if (!sec->strtab) {
0480             die("malloc of %" FMT " bytes for strtab failed\n",
0481                 sec->shdr.sh_size);
0482         }
0483         if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
0484             die("Seek to %" FMT " failed: %s\n",
0485                 sec->shdr.sh_offset, strerror(errno));
0486         }
0487         if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
0488             != sec->shdr.sh_size) {
0489             die("Cannot read symbol table: %s\n",
0490                 strerror(errno));
0491         }
0492     }
0493 }
0494 
0495 static void read_symtabs(FILE *fp)
0496 {
0497     int i,j;
0498 
0499     for (i = 0; i < shnum; i++) {
0500         struct section *sec = &secs[i];
0501         int num_syms;
0502 
0503         switch (sec->shdr.sh_type) {
0504         case SHT_SYMTAB_SHNDX:
0505             sec->xsymtab = malloc(sec->shdr.sh_size);
0506             if (!sec->xsymtab) {
0507                 die("malloc of %" FMT " bytes for xsymtab failed\n",
0508                     sec->shdr.sh_size);
0509             }
0510             if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
0511                 die("Seek to %" FMT " failed: %s\n",
0512                     sec->shdr.sh_offset, strerror(errno));
0513             }
0514             if (fread(sec->xsymtab, 1, sec->shdr.sh_size, fp)
0515                 != sec->shdr.sh_size) {
0516                 die("Cannot read extended symbol table: %s\n",
0517                     strerror(errno));
0518             }
0519             shxsymtabndx = i;
0520             continue;
0521 
0522         case SHT_SYMTAB:
0523             num_syms = sec->shdr.sh_size / sizeof(Elf_Sym);
0524 
0525             sec->symtab = malloc(sec->shdr.sh_size);
0526             if (!sec->symtab) {
0527                 die("malloc of %" FMT " bytes for symtab failed\n",
0528                     sec->shdr.sh_size);
0529             }
0530             if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
0531                 die("Seek to %" FMT " failed: %s\n",
0532                     sec->shdr.sh_offset, strerror(errno));
0533             }
0534             if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
0535                 != sec->shdr.sh_size) {
0536                 die("Cannot read symbol table: %s\n",
0537                     strerror(errno));
0538             }
0539             for (j = 0; j < num_syms; j++) {
0540                 Elf_Sym *sym = &sec->symtab[j];
0541 
0542                 sym->st_name  = elf_word_to_cpu(sym->st_name);
0543                 sym->st_value = elf_addr_to_cpu(sym->st_value);
0544                 sym->st_size  = elf_xword_to_cpu(sym->st_size);
0545                 sym->st_shndx = elf_half_to_cpu(sym->st_shndx);
0546             }
0547             shsymtabndx = i;
0548             continue;
0549 
0550         default:
0551             continue;
0552         }
0553     }
0554 }
0555 
0556 
0557 static void read_relocs(FILE *fp)
0558 {
0559     int i,j;
0560     for (i = 0; i < shnum; i++) {
0561         struct section *sec = &secs[i];
0562         if (sec->shdr.sh_type != SHT_REL_TYPE) {
0563             continue;
0564         }
0565         sec->reltab = malloc(sec->shdr.sh_size);
0566         if (!sec->reltab) {
0567             die("malloc of %" FMT " bytes for relocs failed\n",
0568                 sec->shdr.sh_size);
0569         }
0570         if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
0571             die("Seek to %" FMT " failed: %s\n",
0572                 sec->shdr.sh_offset, strerror(errno));
0573         }
0574         if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
0575             != sec->shdr.sh_size) {
0576             die("Cannot read symbol table: %s\n",
0577                 strerror(errno));
0578         }
0579         for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
0580             Elf_Rel *rel = &sec->reltab[j];
0581             rel->r_offset = elf_addr_to_cpu(rel->r_offset);
0582             rel->r_info   = elf_xword_to_cpu(rel->r_info);
0583 #if (SHT_REL_TYPE == SHT_RELA)
0584             rel->r_addend = elf_xword_to_cpu(rel->r_addend);
0585 #endif
0586         }
0587     }
0588 }
0589 
0590 
0591 static void print_absolute_symbols(void)
0592 {
0593     int i;
0594     const char *format;
0595 
0596     if (ELF_BITS == 64)
0597         format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n";
0598     else
0599         format = "%5d %08"PRIx32"  %5"PRId32" %10s %10s %12s %s\n";
0600 
0601     printf("Absolute symbols\n");
0602     printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
0603     for (i = 0; i < shnum; i++) {
0604         struct section *sec = &secs[i];
0605         char *sym_strtab;
0606         int j;
0607 
0608         if (sec->shdr.sh_type != SHT_SYMTAB) {
0609             continue;
0610         }
0611         sym_strtab = sec->link->strtab;
0612         for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) {
0613             Elf_Sym *sym;
0614             const char *name;
0615             sym = &sec->symtab[j];
0616             name = sym_name(sym_strtab, sym);
0617             if (sym->st_shndx != SHN_ABS) {
0618                 continue;
0619             }
0620             printf(format,
0621                 j, sym->st_value, sym->st_size,
0622                 sym_type(ELF_ST_TYPE(sym->st_info)),
0623                 sym_bind(ELF_ST_BIND(sym->st_info)),
0624                 sym_visibility(ELF_ST_VISIBILITY(sym->st_other)),
0625                 name);
0626         }
0627     }
0628     printf("\n");
0629 }
0630 
0631 static void print_absolute_relocs(void)
0632 {
0633     int i, printed = 0;
0634     const char *format;
0635 
0636     if (ELF_BITS == 64)
0637         format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64"  %s\n";
0638     else
0639         format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32"  %s\n";
0640 
0641     for (i = 0; i < shnum; i++) {
0642         struct section *sec = &secs[i];
0643         struct section *sec_applies, *sec_symtab;
0644         char *sym_strtab;
0645         Elf_Sym *sh_symtab;
0646         int j;
0647         if (sec->shdr.sh_type != SHT_REL_TYPE) {
0648             continue;
0649         }
0650         sec_symtab  = sec->link;
0651         sec_applies = &secs[sec->shdr.sh_info];
0652         if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
0653             continue;
0654         }
0655         sh_symtab  = sec_symtab->symtab;
0656         sym_strtab = sec_symtab->link->strtab;
0657         for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
0658             Elf_Rel *rel;
0659             Elf_Sym *sym;
0660             const char *name;
0661             rel = &sec->reltab[j];
0662             sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
0663             name = sym_name(sym_strtab, sym);
0664             if (sym->st_shndx != SHN_ABS) {
0665                 continue;
0666             }
0667 
0668             /* Absolute symbols are not relocated if bzImage is
0669              * loaded at a non-compiled address. Display a warning
0670              * to user at compile time about the absolute
0671              * relocations present.
0672              *
0673              * User need to audit the code to make sure
0674              * some symbols which should have been section
0675              * relative have not become absolute because of some
0676              * linker optimization or wrong programming usage.
0677              *
0678              * Before warning check if this absolute symbol
0679              * relocation is harmless.
0680              */
0681             if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
0682                 continue;
0683 
0684             if (!printed) {
0685                 printf("WARNING: Absolute relocations"
0686                     " present\n");
0687                 printf("Offset     Info     Type     Sym.Value "
0688                     "Sym.Name\n");
0689                 printed = 1;
0690             }
0691 
0692             printf(format,
0693                 rel->r_offset,
0694                 rel->r_info,
0695                 rel_type(ELF_R_TYPE(rel->r_info)),
0696                 sym->st_value,
0697                 name);
0698         }
0699     }
0700 
0701     if (printed)
0702         printf("\n");
0703 }
0704 
0705 static void add_reloc(struct relocs *r, uint32_t offset)
0706 {
0707     if (r->count == r->size) {
0708         unsigned long newsize = r->size + 50000;
0709         void *mem = realloc(r->offset, newsize * sizeof(r->offset[0]));
0710 
0711         if (!mem)
0712             die("realloc of %ld entries for relocs failed\n",
0713                                 newsize);
0714         r->offset = mem;
0715         r->size = newsize;
0716     }
0717     r->offset[r->count++] = offset;
0718 }
0719 
0720 static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
0721             Elf_Sym *sym, const char *symname))
0722 {
0723     int i;
0724     /* Walk through the relocations */
0725     for (i = 0; i < shnum; i++) {
0726         char *sym_strtab;
0727         Elf_Sym *sh_symtab;
0728         struct section *sec_applies, *sec_symtab;
0729         int j;
0730         struct section *sec = &secs[i];
0731 
0732         if (sec->shdr.sh_type != SHT_REL_TYPE) {
0733             continue;
0734         }
0735         sec_symtab  = sec->link;
0736         sec_applies = &secs[sec->shdr.sh_info];
0737         if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
0738             continue;
0739         }
0740         sh_symtab = sec_symtab->symtab;
0741         sym_strtab = sec_symtab->link->strtab;
0742         for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
0743             Elf_Rel *rel = &sec->reltab[j];
0744             Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
0745             const char *symname = sym_name(sym_strtab, sym);
0746 
0747             process(sec, rel, sym, symname);
0748         }
0749     }
0750 }
0751 
0752 /*
0753  * The .data..percpu section is a special case for x86_64 SMP kernels.
0754  * It is used to initialize the actual per_cpu areas and to provide
0755  * definitions for the per_cpu variables that correspond to their offsets
0756  * within the percpu area. Since the values of all of the symbols need
0757  * to be offsets from the start of the per_cpu area the virtual address
0758  * (sh_addr) of .data..percpu is 0 in SMP kernels.
0759  *
0760  * This means that:
0761  *
0762  *  Relocations that reference symbols in the per_cpu area do not
0763  *  need further relocation (since the value is an offset relative
0764  *  to the start of the per_cpu area that does not change).
0765  *
0766  *  Relocations that apply to the per_cpu area need to have their
0767  *  offset adjusted by by the value of __per_cpu_load to make them
0768  *  point to the correct place in the loaded image (because the
0769  *  virtual address of .data..percpu is 0).
0770  *
0771  * For non SMP kernels .data..percpu is linked as part of the normal
0772  * kernel data and does not require special treatment.
0773  *
0774  */
0775 static int per_cpu_shndx    = -1;
0776 static Elf_Addr per_cpu_load_addr;
0777 
0778 static void percpu_init(void)
0779 {
0780     int i;
0781     for (i = 0; i < shnum; i++) {
0782         ElfW(Sym) *sym;
0783         if (strcmp(sec_name(i), ".data..percpu"))
0784             continue;
0785 
0786         if (secs[i].shdr.sh_addr != 0)  /* non SMP kernel */
0787             return;
0788 
0789         sym = sym_lookup("__per_cpu_load");
0790         if (!sym)
0791             die("can't find __per_cpu_load\n");
0792 
0793         per_cpu_shndx = i;
0794         per_cpu_load_addr = sym->st_value;
0795         return;
0796     }
0797 }
0798 
0799 #if ELF_BITS == 64
0800 
0801 /*
0802  * Check to see if a symbol lies in the .data..percpu section.
0803  *
0804  * The linker incorrectly associates some symbols with the
0805  * .data..percpu section so we also need to check the symbol
0806  * name to make sure that we classify the symbol correctly.
0807  *
0808  * The GNU linker incorrectly associates:
0809  *  __init_begin
0810  *  __per_cpu_load
0811  *
0812  * The "gold" linker incorrectly associates:
0813  *  init_per_cpu__fixed_percpu_data
0814  *  init_per_cpu__gdt_page
0815  */
0816 static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
0817 {
0818     int shndx = sym_index(sym);
0819 
0820     return (shndx == per_cpu_shndx) &&
0821         strcmp(symname, "__init_begin") &&
0822         strcmp(symname, "__per_cpu_load") &&
0823         strncmp(symname, "init_per_cpu_", 13);
0824 }
0825 
0826 
0827 static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
0828               const char *symname)
0829 {
0830     unsigned r_type = ELF64_R_TYPE(rel->r_info);
0831     ElfW(Addr) offset = rel->r_offset;
0832     int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
0833 
0834     if (sym->st_shndx == SHN_UNDEF)
0835         return 0;
0836 
0837     /*
0838      * Adjust the offset if this reloc applies to the percpu section.
0839      */
0840     if (sec->shdr.sh_info == per_cpu_shndx)
0841         offset += per_cpu_load_addr;
0842 
0843     switch (r_type) {
0844     case R_X86_64_NONE:
0845         /* NONE can be ignored. */
0846         break;
0847 
0848     case R_X86_64_PC32:
0849     case R_X86_64_PLT32:
0850         /*
0851          * PC relative relocations don't need to be adjusted unless
0852          * referencing a percpu symbol.
0853          *
0854          * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
0855          */
0856         if (is_percpu_sym(sym, symname))
0857             add_reloc(&relocs32neg, offset);
0858         break;
0859 
0860     case R_X86_64_PC64:
0861         /*
0862          * Only used by jump labels
0863          */
0864         if (is_percpu_sym(sym, symname))
0865             die("Invalid R_X86_64_PC64 relocation against per-CPU symbol %s\n",
0866                 symname);
0867         break;
0868 
0869     case R_X86_64_32:
0870     case R_X86_64_32S:
0871     case R_X86_64_64:
0872         /*
0873          * References to the percpu area don't need to be adjusted.
0874          */
0875         if (is_percpu_sym(sym, symname))
0876             break;
0877 
0878         if (shn_abs) {
0879             /*
0880              * Whitelisted absolute symbols do not require
0881              * relocation.
0882              */
0883             if (is_reloc(S_ABS, symname))
0884                 break;
0885 
0886             die("Invalid absolute %s relocation: %s\n",
0887                 rel_type(r_type), symname);
0888             break;
0889         }
0890 
0891         /*
0892          * Relocation offsets for 64 bit kernels are output
0893          * as 32 bits and sign extended back to 64 bits when
0894          * the relocations are processed.
0895          * Make sure that the offset will fit.
0896          */
0897         if ((int32_t)offset != (int64_t)offset)
0898             die("Relocation offset doesn't fit in 32 bits\n");
0899 
0900         if (r_type == R_X86_64_64)
0901             add_reloc(&relocs64, offset);
0902         else
0903             add_reloc(&relocs32, offset);
0904         break;
0905 
0906     default:
0907         die("Unsupported relocation type: %s (%d)\n",
0908             rel_type(r_type), r_type);
0909         break;
0910     }
0911 
0912     return 0;
0913 }
0914 
0915 #else
0916 
0917 static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
0918               const char *symname)
0919 {
0920     unsigned r_type = ELF32_R_TYPE(rel->r_info);
0921     int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
0922 
0923     switch (r_type) {
0924     case R_386_NONE:
0925     case R_386_PC32:
0926     case R_386_PC16:
0927     case R_386_PC8:
0928     case R_386_PLT32:
0929         /*
0930          * NONE can be ignored and PC relative relocations don't need
0931          * to be adjusted. Because sym must be defined, R_386_PLT32 can
0932          * be treated the same way as R_386_PC32.
0933          */
0934         break;
0935 
0936     case R_386_32:
0937         if (shn_abs) {
0938             /*
0939              * Whitelisted absolute symbols do not require
0940              * relocation.
0941              */
0942             if (is_reloc(S_ABS, symname))
0943                 break;
0944 
0945             die("Invalid absolute %s relocation: %s\n",
0946                 rel_type(r_type), symname);
0947             break;
0948         }
0949 
0950         add_reloc(&relocs32, rel->r_offset);
0951         break;
0952 
0953     default:
0954         die("Unsupported relocation type: %s (%d)\n",
0955             rel_type(r_type), r_type);
0956         break;
0957     }
0958 
0959     return 0;
0960 }
0961 
0962 static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
0963              const char *symname)
0964 {
0965     unsigned r_type = ELF32_R_TYPE(rel->r_info);
0966     int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
0967 
0968     switch (r_type) {
0969     case R_386_NONE:
0970     case R_386_PC32:
0971     case R_386_PC16:
0972     case R_386_PC8:
0973     case R_386_PLT32:
0974         /*
0975          * NONE can be ignored and PC relative relocations don't need
0976          * to be adjusted. Because sym must be defined, R_386_PLT32 can
0977          * be treated the same way as R_386_PC32.
0978          */
0979         break;
0980 
0981     case R_386_16:
0982         if (shn_abs) {
0983             /*
0984              * Whitelisted absolute symbols do not require
0985              * relocation.
0986              */
0987             if (is_reloc(S_ABS, symname))
0988                 break;
0989 
0990             if (is_reloc(S_SEG, symname)) {
0991                 add_reloc(&relocs16, rel->r_offset);
0992                 break;
0993             }
0994         } else {
0995             if (!is_reloc(S_LIN, symname))
0996                 break;
0997         }
0998         die("Invalid %s %s relocation: %s\n",
0999             shn_abs ? "absolute" : "relative",
1000             rel_type(r_type), symname);
1001         break;
1002 
1003     case R_386_32:
1004         if (shn_abs) {
1005             /*
1006              * Whitelisted absolute symbols do not require
1007              * relocation.
1008              */
1009             if (is_reloc(S_ABS, symname))
1010                 break;
1011 
1012             if (is_reloc(S_REL, symname)) {
1013                 add_reloc(&relocs32, rel->r_offset);
1014                 break;
1015             }
1016         } else {
1017             if (is_reloc(S_LIN, symname))
1018                 add_reloc(&relocs32, rel->r_offset);
1019             break;
1020         }
1021         die("Invalid %s %s relocation: %s\n",
1022             shn_abs ? "absolute" : "relative",
1023             rel_type(r_type), symname);
1024         break;
1025 
1026     default:
1027         die("Unsupported relocation type: %s (%d)\n",
1028             rel_type(r_type), r_type);
1029         break;
1030     }
1031 
1032     return 0;
1033 }
1034 
1035 #endif
1036 
1037 static int cmp_relocs(const void *va, const void *vb)
1038 {
1039     const uint32_t *a, *b;
1040     a = va; b = vb;
1041     return (*a == *b)? 0 : (*a > *b)? 1 : -1;
1042 }
1043 
1044 static void sort_relocs(struct relocs *r)
1045 {
1046     qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
1047 }
1048 
1049 static int write32(uint32_t v, FILE *f)
1050 {
1051     unsigned char buf[4];
1052 
1053     put_unaligned_le32(v, buf);
1054     return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
1055 }
1056 
1057 static int write32_as_text(uint32_t v, FILE *f)
1058 {
1059     return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1;
1060 }
1061 
1062 static void emit_relocs(int as_text, int use_real_mode)
1063 {
1064     int i;
1065     int (*write_reloc)(uint32_t, FILE *) = write32;
1066     int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
1067             const char *symname);
1068 
1069 #if ELF_BITS == 64
1070     if (!use_real_mode)
1071         do_reloc = do_reloc64;
1072     else
1073         die("--realmode not valid for a 64-bit ELF file");
1074 #else
1075     if (!use_real_mode)
1076         do_reloc = do_reloc32;
1077     else
1078         do_reloc = do_reloc_real;
1079 #endif
1080 
1081     /* Collect up the relocations */
1082     walk_relocs(do_reloc);
1083 
1084     if (relocs16.count && !use_real_mode)
1085         die("Segment relocations found but --realmode not specified\n");
1086 
1087     /* Order the relocations for more efficient processing */
1088     sort_relocs(&relocs32);
1089 #if ELF_BITS == 64
1090     sort_relocs(&relocs32neg);
1091     sort_relocs(&relocs64);
1092 #else
1093     sort_relocs(&relocs16);
1094 #endif
1095 
1096     /* Print the relocations */
1097     if (as_text) {
1098         /* Print the relocations in a form suitable that
1099          * gas will like.
1100          */
1101         printf(".section \".data.reloc\",\"a\"\n");
1102         printf(".balign 4\n");
1103         write_reloc = write32_as_text;
1104     }
1105 
1106     if (use_real_mode) {
1107         write_reloc(relocs16.count, stdout);
1108         for (i = 0; i < relocs16.count; i++)
1109             write_reloc(relocs16.offset[i], stdout);
1110 
1111         write_reloc(relocs32.count, stdout);
1112         for (i = 0; i < relocs32.count; i++)
1113             write_reloc(relocs32.offset[i], stdout);
1114     } else {
1115 #if ELF_BITS == 64
1116         /* Print a stop */
1117         write_reloc(0, stdout);
1118 
1119         /* Now print each relocation */
1120         for (i = 0; i < relocs64.count; i++)
1121             write_reloc(relocs64.offset[i], stdout);
1122 
1123         /* Print a stop */
1124         write_reloc(0, stdout);
1125 
1126         /* Now print each inverse 32-bit relocation */
1127         for (i = 0; i < relocs32neg.count; i++)
1128             write_reloc(relocs32neg.offset[i], stdout);
1129 #endif
1130 
1131         /* Print a stop */
1132         write_reloc(0, stdout);
1133 
1134         /* Now print each relocation */
1135         for (i = 0; i < relocs32.count; i++)
1136             write_reloc(relocs32.offset[i], stdout);
1137     }
1138 }
1139 
1140 /*
1141  * As an aid to debugging problems with different linkers
1142  * print summary information about the relocs.
1143  * Since different linkers tend to emit the sections in
1144  * different orders we use the section names in the output.
1145  */
1146 static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
1147                 const char *symname)
1148 {
1149     printf("%s\t%s\t%s\t%s\n",
1150         sec_name(sec->shdr.sh_info),
1151         rel_type(ELF_R_TYPE(rel->r_info)),
1152         symname,
1153         sec_name(sym_index(sym)));
1154     return 0;
1155 }
1156 
1157 static void print_reloc_info(void)
1158 {
1159     printf("reloc section\treloc type\tsymbol\tsymbol section\n");
1160     walk_relocs(do_reloc_info);
1161 }
1162 
1163 #if ELF_BITS == 64
1164 # define process process_64
1165 #else
1166 # define process process_32
1167 #endif
1168 
1169 void process(FILE *fp, int use_real_mode, int as_text,
1170          int show_absolute_syms, int show_absolute_relocs,
1171          int show_reloc_info)
1172 {
1173     regex_init(use_real_mode);
1174     read_ehdr(fp);
1175     read_shdrs(fp);
1176     read_strtabs(fp);
1177     read_symtabs(fp);
1178     read_relocs(fp);
1179     if (ELF_BITS == 64)
1180         percpu_init();
1181     if (show_absolute_syms) {
1182         print_absolute_symbols();
1183         return;
1184     }
1185     if (show_absolute_relocs) {
1186         print_absolute_relocs();
1187         return;
1188     }
1189     if (show_reloc_info) {
1190         print_reloc_info();
1191         return;
1192     }
1193     emit_relocs(as_text, use_real_mode);
1194 }
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