Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Matt Redfearn | 3504 | 99.94% | 1 | 33.33% |
Greg Kroah-Hartman | 1 | 0.03% | 1 | 33.33% |
Alexey Dobriyan | 1 | 0.03% | 1 | 33.33% |
Total | 3506 | 3 |
// SPDX-License-Identifier: GPL-2.0 /* This is included from relocs_32/64.c */ #define ElfW(type) _ElfW(ELF_BITS, type) #define _ElfW(bits, type) __ElfW(bits, type) #define __ElfW(bits, type) Elf##bits##_##type #define Elf_Addr ElfW(Addr) #define Elf_Ehdr ElfW(Ehdr) #define Elf_Phdr ElfW(Phdr) #define Elf_Shdr ElfW(Shdr) #define Elf_Sym ElfW(Sym) static Elf_Ehdr ehdr; struct relocs { uint32_t *offset; unsigned long count; unsigned long size; }; static struct relocs relocs; struct section { Elf_Shdr shdr; struct section *link; Elf_Sym *symtab; Elf_Rel *reltab; char *strtab; long shdr_offset; }; static struct section *secs; static const char * const regex_sym_kernel = { /* Symbols matching these regex's should never be relocated */ "^(__crc_)", }; static regex_t sym_regex_c; static int regex_skip_reloc(const char *sym_name) { return !regexec(&sym_regex_c, sym_name, 0, NULL, 0); } static void regex_init(void) { char errbuf[128]; int err; err = regcomp(&sym_regex_c, regex_sym_kernel, REG_EXTENDED|REG_NOSUB); if (err) { regerror(err, &sym_regex_c, errbuf, sizeof(errbuf)); die("%s", errbuf); } } static const char *rel_type(unsigned type) { static const char * const type_name[] = { #define REL_TYPE(X)[X] = #X REL_TYPE(R_MIPS_NONE), REL_TYPE(R_MIPS_16), REL_TYPE(R_MIPS_32), REL_TYPE(R_MIPS_REL32), REL_TYPE(R_MIPS_26), REL_TYPE(R_MIPS_HI16), REL_TYPE(R_MIPS_LO16), REL_TYPE(R_MIPS_GPREL16), REL_TYPE(R_MIPS_LITERAL), REL_TYPE(R_MIPS_GOT16), REL_TYPE(R_MIPS_PC16), REL_TYPE(R_MIPS_CALL16), REL_TYPE(R_MIPS_GPREL32), REL_TYPE(R_MIPS_64), REL_TYPE(R_MIPS_HIGHER), REL_TYPE(R_MIPS_HIGHEST), REL_TYPE(R_MIPS_PC21_S2), REL_TYPE(R_MIPS_PC26_S2), #undef REL_TYPE }; const char *name = "unknown type rel type name"; if (type < ARRAY_SIZE(type_name) && type_name[type]) name = type_name[type]; return name; } static const char *sec_name(unsigned shndx) { const char *sec_strtab; const char *name; sec_strtab = secs[ehdr.e_shstrndx].strtab; if (shndx < ehdr.e_shnum) name = sec_strtab + secs[shndx].shdr.sh_name; else if (shndx == SHN_ABS) name = "ABSOLUTE"; else if (shndx == SHN_COMMON) name = "COMMON"; else name = "<noname>"; return name; } static struct section *sec_lookup(const char *secname) { int i; for (i = 0; i < ehdr.e_shnum; i++) if (strcmp(secname, sec_name(i)) == 0) return &secs[i]; return NULL; } static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) { const char *name; if (sym->st_name) name = sym_strtab + sym->st_name; else name = sec_name(sym->st_shndx); return name; } #if BYTE_ORDER == LITTLE_ENDIAN #define le16_to_cpu(val) (val) #define le32_to_cpu(val) (val) #define le64_to_cpu(val) (val) #define be16_to_cpu(val) bswap_16(val) #define be32_to_cpu(val) bswap_32(val) #define be64_to_cpu(val) bswap_64(val) #define cpu_to_le16(val) (val) #define cpu_to_le32(val) (val) #define cpu_to_le64(val) (val) #define cpu_to_be16(val) bswap_16(val) #define cpu_to_be32(val) bswap_32(val) #define cpu_to_be64(val) bswap_64(val) #endif #if BYTE_ORDER == BIG_ENDIAN #define le16_to_cpu(val) bswap_16(val) #define le32_to_cpu(val) bswap_32(val) #define le64_to_cpu(val) bswap_64(val) #define be16_to_cpu(val) (val) #define be32_to_cpu(val) (val) #define be64_to_cpu(val) (val) #define cpu_to_le16(val) bswap_16(val) #define cpu_to_le32(val) bswap_32(val) #define cpu_to_le64(val) bswap_64(val) #define cpu_to_be16(val) (val) #define cpu_to_be32(val) (val) #define cpu_to_be64(val) (val) #endif static uint16_t elf16_to_cpu(uint16_t val) { if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) return le16_to_cpu(val); else return be16_to_cpu(val); } static uint32_t elf32_to_cpu(uint32_t val) { if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) return le32_to_cpu(val); else return be32_to_cpu(val); } static uint32_t cpu_to_elf32(uint32_t val) { if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) return cpu_to_le32(val); else return cpu_to_be32(val); } #define elf_half_to_cpu(x) elf16_to_cpu(x) #define elf_word_to_cpu(x) elf32_to_cpu(x) #if ELF_BITS == 64 static uint64_t elf64_to_cpu(uint64_t val) { if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) return le64_to_cpu(val); else return be64_to_cpu(val); } #define elf_addr_to_cpu(x) elf64_to_cpu(x) #define elf_off_to_cpu(x) elf64_to_cpu(x) #define elf_xword_to_cpu(x) elf64_to_cpu(x) #else #define elf_addr_to_cpu(x) elf32_to_cpu(x) #define elf_off_to_cpu(x) elf32_to_cpu(x) #define elf_xword_to_cpu(x) elf32_to_cpu(x) #endif static void read_ehdr(FILE *fp) { if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) die("Cannot read ELF header: %s\n", strerror(errno)); if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) die("No ELF magic\n"); if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) die("Not a %d bit executable\n", ELF_BITS); if ((ehdr.e_ident[EI_DATA] != ELFDATA2LSB) && (ehdr.e_ident[EI_DATA] != ELFDATA2MSB)) die("Unknown ELF Endianness\n"); if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) die("Unknown ELF version\n"); /* Convert the fields to native endian */ ehdr.e_type = elf_half_to_cpu(ehdr.e_type); ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine); ehdr.e_version = elf_word_to_cpu(ehdr.e_version); ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry); ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff); ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff); ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags); ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize); ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize); ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum); ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize); ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum); ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx); if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) die("Unsupported ELF header type\n"); if (ehdr.e_machine != ELF_MACHINE) die("Not for %s\n", ELF_MACHINE_NAME); if (ehdr.e_version != EV_CURRENT) die("Unknown ELF version\n"); if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) die("Bad ELF header size\n"); if (ehdr.e_phentsize != sizeof(Elf_Phdr)) die("Bad program header entry\n"); if (ehdr.e_shentsize != sizeof(Elf_Shdr)) die("Bad section header entry\n"); if (ehdr.e_shstrndx >= ehdr.e_shnum) die("String table index out of bounds\n"); } static void read_shdrs(FILE *fp) { int i; Elf_Shdr shdr; secs = calloc(ehdr.e_shnum, sizeof(struct section)); if (!secs) die("Unable to allocate %d section headers\n", ehdr.e_shnum); if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) die("Seek to %d failed: %s\n", ehdr.e_shoff, strerror(errno)); for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; sec->shdr_offset = ftell(fp); if (fread(&shdr, sizeof(shdr), 1, fp) != 1) die("Cannot read ELF section headers %d/%d: %s\n", i, ehdr.e_shnum, strerror(errno)); sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name); sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type); sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags); sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr); sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset); sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size); sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link); sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info); sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign); sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize); if (sec->shdr.sh_link < ehdr.e_shnum) sec->link = &secs[sec->shdr.sh_link]; } } static void read_strtabs(FILE *fp) { int i; for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; if (sec->shdr.sh_type != SHT_STRTAB) continue; sec->strtab = malloc(sec->shdr.sh_size); if (!sec->strtab) die("malloc of %d bytes for strtab failed\n", sec->shdr.sh_size); if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) die("Seek to %d failed: %s\n", sec->shdr.sh_offset, strerror(errno)); if (fread(sec->strtab, 1, sec->shdr.sh_size, fp) != sec->shdr.sh_size) die("Cannot read symbol table: %s\n", strerror(errno)); } } static void read_symtabs(FILE *fp) { int i, j; for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; if (sec->shdr.sh_type != SHT_SYMTAB) continue; sec->symtab = malloc(sec->shdr.sh_size); if (!sec->symtab) die("malloc of %d bytes for symtab failed\n", sec->shdr.sh_size); if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) die("Seek to %d failed: %s\n", sec->shdr.sh_offset, strerror(errno)); if (fread(sec->symtab, 1, sec->shdr.sh_size, fp) != sec->shdr.sh_size) die("Cannot read symbol table: %s\n", strerror(errno)); for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) { Elf_Sym *sym = &sec->symtab[j]; sym->st_name = elf_word_to_cpu(sym->st_name); sym->st_value = elf_addr_to_cpu(sym->st_value); sym->st_size = elf_xword_to_cpu(sym->st_size); sym->st_shndx = elf_half_to_cpu(sym->st_shndx); } } } static void read_relocs(FILE *fp) { static unsigned long base; int i, j; if (!base) { struct section *sec = sec_lookup(".text"); if (!sec) die("Could not find .text section\n"); base = sec->shdr.sh_addr; } for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; if (sec->shdr.sh_type != SHT_REL_TYPE) continue; sec->reltab = malloc(sec->shdr.sh_size); if (!sec->reltab) die("malloc of %d bytes for relocs failed\n", sec->shdr.sh_size); if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) die("Seek to %d failed: %s\n", sec->shdr.sh_offset, strerror(errno)); if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) != sec->shdr.sh_size) die("Cannot read symbol table: %s\n", strerror(errno)); for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { Elf_Rel *rel = &sec->reltab[j]; rel->r_offset = elf_addr_to_cpu(rel->r_offset); /* Set offset into kernel image */ rel->r_offset -= base; #if (ELF_BITS == 32) rel->r_info = elf_xword_to_cpu(rel->r_info); #else /* Convert MIPS64 RELA format - only the symbol * index needs converting to native endianness */ rel->r_info = rel->r_info; ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info)); #endif #if (SHT_REL_TYPE == SHT_RELA) rel->r_addend = elf_xword_to_cpu(rel->r_addend); #endif } } } static void remove_relocs(FILE *fp) { int i; Elf_Shdr shdr; for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; if (sec->shdr.sh_type != SHT_REL_TYPE) continue; if (fseek(fp, sec->shdr_offset, SEEK_SET) < 0) die("Seek to %d failed: %s\n", sec->shdr_offset, strerror(errno)); if (fread(&shdr, sizeof(shdr), 1, fp) != 1) die("Cannot read ELF section headers %d/%d: %s\n", i, ehdr.e_shnum, strerror(errno)); /* Set relocation section size to 0, effectively removing it. * This is necessary due to lack of support for relocations * in objcopy when creating 32bit elf from 64bit elf. */ shdr.sh_size = 0; if (fseek(fp, sec->shdr_offset, SEEK_SET) < 0) die("Seek to %d failed: %s\n", sec->shdr_offset, strerror(errno)); if (fwrite(&shdr, sizeof(shdr), 1, fp) != 1) die("Cannot write ELF section headers %d/%d: %s\n", i, ehdr.e_shnum, strerror(errno)); } } static void add_reloc(struct relocs *r, uint32_t offset, unsigned type) { /* Relocation representation in binary table: * |76543210|76543210|76543210|76543210| * | Type | offset from _text >> 2 | */ offset >>= 2; if (offset > 0x00FFFFFF) die("Kernel image exceeds maximum size for relocation!\n"); offset = (offset & 0x00FFFFFF) | ((type & 0xFF) << 24); if (r->count == r->size) { unsigned long newsize = r->size + 50000; void *mem = realloc(r->offset, newsize * sizeof(r->offset[0])); if (!mem) die("realloc failed\n"); r->offset = mem; r->size = newsize; } r->offset[r->count++] = offset; } static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname)) { int i; /* Walk through the relocations */ for (i = 0; i < ehdr.e_shnum; i++) { char *sym_strtab; Elf_Sym *sh_symtab; struct section *sec_applies, *sec_symtab; int j; struct section *sec = &secs[i]; if (sec->shdr.sh_type != SHT_REL_TYPE) continue; sec_symtab = sec->link; sec_applies = &secs[sec->shdr.sh_info]; if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) continue; sh_symtab = sec_symtab->symtab; sym_strtab = sec_symtab->link->strtab; for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { Elf_Rel *rel = &sec->reltab[j]; Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; const char *symname = sym_name(sym_strtab, sym); process(sec, rel, sym, symname); } } } static int do_reloc(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname) { unsigned r_type = ELF_R_TYPE(rel->r_info); unsigned bind = ELF_ST_BIND(sym->st_info); if ((bind == STB_WEAK) && (sym->st_value == 0)) { /* Don't relocate weak symbols without a target */ return 0; } if (regex_skip_reloc(symname)) return 0; switch (r_type) { case R_MIPS_NONE: case R_MIPS_REL32: case R_MIPS_PC16: case R_MIPS_PC21_S2: case R_MIPS_PC26_S2: /* * NONE can be ignored and PC relative relocations don't * need to be adjusted. */ case R_MIPS_HIGHEST: case R_MIPS_HIGHER: /* We support relocating within the same 4Gb segment only, * thus leaving the top 32bits unchanged */ case R_MIPS_LO16: /* We support relocating by 64k jumps only * thus leaving the bottom 16bits unchanged */ break; case R_MIPS_64: case R_MIPS_32: case R_MIPS_26: case R_MIPS_HI16: add_reloc(&relocs, rel->r_offset, r_type); break; default: die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type); break; } return 0; } static int write_reloc_as_bin(uint32_t v, FILE *f) { unsigned char buf[4]; v = cpu_to_elf32(v); memcpy(buf, &v, sizeof(uint32_t)); return fwrite(buf, 1, 4, f); } static int write_reloc_as_text(uint32_t v, FILE *f) { int res; res = fprintf(f, "\t.long 0x%08"PRIx32"\n", v); if (res < 0) return res; else return sizeof(uint32_t); } static void emit_relocs(int as_text, int as_bin, FILE *outf) { int i; int (*write_reloc)(uint32_t, FILE *) = write_reloc_as_bin; int size = 0; int size_reserved; struct section *sec_reloc; sec_reloc = sec_lookup(".data.reloc"); if (!sec_reloc) die("Could not find relocation section\n"); size_reserved = sec_reloc->shdr.sh_size; /* Collect up the relocations */ walk_relocs(do_reloc); /* Print the relocations */ if (as_text) { /* Print the relocations in a form suitable that * gas will like. */ printf(".section \".data.reloc\",\"a\"\n"); printf(".balign 4\n"); /* Output text to stdout */ write_reloc = write_reloc_as_text; outf = stdout; } else if (as_bin) { /* Output raw binary to stdout */ outf = stdout; } else { /* Seek to offset of the relocation section. * Each relocation is then written into the * vmlinux kernel image. */ if (fseek(outf, sec_reloc->shdr.sh_offset, SEEK_SET) < 0) { die("Seek to %d failed: %s\n", sec_reloc->shdr.sh_offset, strerror(errno)); } } for (i = 0; i < relocs.count; i++) size += write_reloc(relocs.offset[i], outf); /* Print a stop, but only if we've actually written some relocs */ if (size) size += write_reloc(0, outf); if (size > size_reserved) /* Die, but suggest a value for CONFIG_RELOCATION_TABLE_SIZE * which will fix this problem and allow a bit of headroom * if more kernel features are enabled */ die("Relocations overflow available space!\n" \ "Please adjust CONFIG_RELOCATION_TABLE_SIZE " \ "to at least 0x%08x\n", (size + 0x1000) & ~0xFFF); } /* * As an aid to debugging problems with different linkers * print summary information about the relocs. * Since different linkers tend to emit the sections in * different orders we use the section names in the output. */ static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, const char *symname) { printf("%16s 0x%08x %16s %40s %16s\n", sec_name(sec->shdr.sh_info), (unsigned int)rel->r_offset, rel_type(ELF_R_TYPE(rel->r_info)), symname, sec_name(sym->st_shndx)); return 0; } static void print_reloc_info(void) { printf("%16s %10s %16s %40s %16s\n", "reloc section", "offset", "reloc type", "symbol", "symbol section"); walk_relocs(do_reloc_info); } #if ELF_BITS == 64 # define process process_64 #else # define process process_32 #endif void process(FILE *fp, int as_text, int as_bin, int show_reloc_info, int keep_relocs) { regex_init(); read_ehdr(fp); read_shdrs(fp); read_strtabs(fp); read_symtabs(fp); read_relocs(fp); if (show_reloc_info) { print_reloc_info(); return; } emit_relocs(as_text, as_bin, fp); if (!keep_relocs) remove_relocs(fp); }
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