diff options
Diffstat (limited to 'arch/i386/boot/compressed/relocs.c')
| -rw-r--r-- | arch/i386/boot/compressed/relocs.c | 631 |
1 files changed, 0 insertions, 631 deletions
diff --git a/arch/i386/boot/compressed/relocs.c b/arch/i386/boot/compressed/relocs.c deleted file mode 100644 index 2d77ee7..0000000 --- a/arch/i386/boot/compressed/relocs.c +++ /dev/null @@ -1,631 +0,0 @@ -#include <stdio.h> -#include <stdarg.h> -#include <stdlib.h> -#include <stdint.h> -#include <string.h> -#include <errno.h> -#include <unistd.h> -#include <elf.h> -#include <byteswap.h> -#define USE_BSD -#include <endian.h> - -#define MAX_SHDRS 100 -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) -static Elf32_Ehdr ehdr; -static Elf32_Shdr shdr[MAX_SHDRS]; -static Elf32_Sym *symtab[MAX_SHDRS]; -static Elf32_Rel *reltab[MAX_SHDRS]; -static char *strtab[MAX_SHDRS]; -static unsigned long reloc_count, reloc_idx; -static unsigned long *relocs; - -/* - * Following symbols have been audited. There values are constant and do - * not change if bzImage is loaded at a different physical address than - * the address for which it has been compiled. Don't warn user about - * absolute relocations present w.r.t these symbols. - */ -static const char* safe_abs_relocs[] = { - "__kernel_vsyscall", - "__kernel_rt_sigreturn", - "__kernel_sigreturn", - "SYSENTER_RETURN", - "VDSO_NOTE_MASK", - "xen_irq_disable_direct_reloc", - "xen_save_fl_direct_reloc", -}; - -static int is_safe_abs_reloc(const char* sym_name) -{ - int i, array_size; - - array_size = sizeof(safe_abs_relocs)/sizeof(char*); - - for(i = 0; i < array_size; i++) { - if (!strcmp(sym_name, safe_abs_relocs[i])) - /* Match found */ - return 1; - } - if (strncmp(sym_name, "__crc_", 6) == 0) - return 1; - return 0; -} - -static void die(char *fmt, ...) -{ - va_list ap; - va_start(ap, fmt); - vfprintf(stderr, fmt, ap); - va_end(ap); - exit(1); -} - -static const char *sym_type(unsigned type) -{ - static const char *type_name[] = { -#define SYM_TYPE(X) [X] = #X - SYM_TYPE(STT_NOTYPE), - SYM_TYPE(STT_OBJECT), - SYM_TYPE(STT_FUNC), - SYM_TYPE(STT_SECTION), - SYM_TYPE(STT_FILE), - SYM_TYPE(STT_COMMON), - SYM_TYPE(STT_TLS), -#undef SYM_TYPE - }; - const char *name = "unknown sym type name"; - if (type < ARRAY_SIZE(type_name)) { - name = type_name[type]; - } - return name; -} - -static const char *sym_bind(unsigned bind) -{ - static const char *bind_name[] = { -#define SYM_BIND(X) [X] = #X - SYM_BIND(STB_LOCAL), - SYM_BIND(STB_GLOBAL), - SYM_BIND(STB_WEAK), -#undef SYM_BIND - }; - const char *name = "unknown sym bind name"; - if (bind < ARRAY_SIZE(bind_name)) { - name = bind_name[bind]; - } - return name; -} - -static const char *sym_visibility(unsigned visibility) -{ - static const char *visibility_name[] = { -#define SYM_VISIBILITY(X) [X] = #X - SYM_VISIBILITY(STV_DEFAULT), - SYM_VISIBILITY(STV_INTERNAL), - SYM_VISIBILITY(STV_HIDDEN), - SYM_VISIBILITY(STV_PROTECTED), -#undef SYM_VISIBILITY - }; - const char *name = "unknown sym visibility name"; - if (visibility < ARRAY_SIZE(visibility_name)) { - name = visibility_name[visibility]; - } - return name; -} - -static const char *rel_type(unsigned type) -{ - static const char *type_name[] = { -#define REL_TYPE(X) [X] = #X - REL_TYPE(R_386_NONE), - REL_TYPE(R_386_32), - REL_TYPE(R_386_PC32), - REL_TYPE(R_386_GOT32), - REL_TYPE(R_386_PLT32), - REL_TYPE(R_386_COPY), - REL_TYPE(R_386_GLOB_DAT), - REL_TYPE(R_386_JMP_SLOT), - REL_TYPE(R_386_RELATIVE), - REL_TYPE(R_386_GOTOFF), - REL_TYPE(R_386_GOTPC), -#undef REL_TYPE - }; - const char *name = "unknown type rel type name"; - if (type < ARRAY_SIZE(type_name)) { - name = type_name[type]; - } - return name; -} - -static const char *sec_name(unsigned shndx) -{ - const char *sec_strtab; - const char *name; - sec_strtab = strtab[ehdr.e_shstrndx]; - name = "<noname>"; - if (shndx < ehdr.e_shnum) { - name = sec_strtab + shdr[shndx].sh_name; - } - else if (shndx == SHN_ABS) { - name = "ABSOLUTE"; - } - else if (shndx == SHN_COMMON) { - name = "COMMON"; - } - return name; -} - -static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym) -{ - const char *name; - name = "<noname>"; - if (sym->st_name) { - name = sym_strtab + sym->st_name; - } - else { - name = sec_name(shdr[sym->st_shndx].sh_name); - } - return name; -} - - - -#if BYTE_ORDER == LITTLE_ENDIAN -#define le16_to_cpu(val) (val) -#define le32_to_cpu(val) (val) -#endif -#if BYTE_ORDER == BIG_ENDIAN -#define le16_to_cpu(val) bswap_16(val) -#define le32_to_cpu(val) bswap_32(val) -#endif - -static uint16_t elf16_to_cpu(uint16_t val) -{ - return le16_to_cpu(val); -} - -static uint32_t elf32_to_cpu(uint32_t val) -{ - return le32_to_cpu(val); -} - -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, 4) != 0) { - die("No ELF magic\n"); - } - if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) { - die("Not a 32 bit executable\n"); - } - if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { - die("Not a LSB ELF executable\n"); - } - if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) { - die("Unknown ELF version\n"); - } - /* Convert the fields to native endian */ - ehdr.e_type = elf16_to_cpu(ehdr.e_type); - ehdr.e_machine = elf16_to_cpu(ehdr.e_machine); - ehdr.e_version = elf32_to_cpu(ehdr.e_version); - ehdr.e_entry = elf32_to_cpu(ehdr.e_entry); - ehdr.e_phoff = elf32_to_cpu(ehdr.e_phoff); - ehdr.e_shoff = elf32_to_cpu(ehdr.e_shoff); - ehdr.e_flags = elf32_to_cpu(ehdr.e_flags); - ehdr.e_ehsize = elf16_to_cpu(ehdr.e_ehsize); - ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize); - ehdr.e_phnum = elf16_to_cpu(ehdr.e_phnum); - ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize); - ehdr.e_shnum = elf16_to_cpu(ehdr.e_shnum); - ehdr.e_shstrndx = elf16_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 != EM_386) { - die("Not for x86\n"); - } - if (ehdr.e_version != EV_CURRENT) { - die("Unknown ELF version\n"); - } - if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) { - die("Bad Elf header size\n"); - } - if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) { - die("Bad program header entry\n"); - } - if (ehdr.e_shentsize != sizeof(Elf32_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; - if (ehdr.e_shnum > MAX_SHDRS) { - die("%d section headers supported: %d\n", - ehdr.e_shnum, MAX_SHDRS); - } - if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { - die("Seek to %d failed: %s\n", - ehdr.e_shoff, strerror(errno)); - } - if (fread(&shdr, sizeof(shdr[0]), ehdr.e_shnum, fp) != ehdr.e_shnum) { - die("Cannot read ELF section headers: %s\n", - strerror(errno)); - } - for(i = 0; i < ehdr.e_shnum; i++) { - shdr[i].sh_name = elf32_to_cpu(shdr[i].sh_name); - shdr[i].sh_type = elf32_to_cpu(shdr[i].sh_type); - shdr[i].sh_flags = elf32_to_cpu(shdr[i].sh_flags); - shdr[i].sh_addr = elf32_to_cpu(shdr[i].sh_addr); - shdr[i].sh_offset = elf32_to_cpu(shdr[i].sh_offset); - shdr[i].sh_size = elf32_to_cpu(shdr[i].sh_size); - shdr[i].sh_link = elf32_to_cpu(shdr[i].sh_link); - shdr[i].sh_info = elf32_to_cpu(shdr[i].sh_info); - shdr[i].sh_addralign = elf32_to_cpu(shdr[i].sh_addralign); - shdr[i].sh_entsize = elf32_to_cpu(shdr[i].sh_entsize); - } - -} - -static void read_strtabs(FILE *fp) -{ - int i; - for(i = 0; i < ehdr.e_shnum; i++) { - if (shdr[i].sh_type != SHT_STRTAB) { - continue; - } - strtab[i] = malloc(shdr[i].sh_size); - if (!strtab[i]) { - die("malloc of %d bytes for strtab failed\n", - shdr[i].sh_size); - } - if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { - die("Seek to %d failed: %s\n", - shdr[i].sh_offset, strerror(errno)); - } - if (fread(strtab[i], 1, shdr[i].sh_size, fp) != shdr[i].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++) { - if (shdr[i].sh_type != SHT_SYMTAB) { - continue; - } - symtab[i] = malloc(shdr[i].sh_size); - if (!symtab[i]) { - die("malloc of %d bytes for symtab failed\n", - shdr[i].sh_size); - } - if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { - die("Seek to %d failed: %s\n", - shdr[i].sh_offset, strerror(errno)); - } - if (fread(symtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) { - die("Cannot read symbol table: %s\n", - strerror(errno)); - } - for(j = 0; j < shdr[i].sh_size/sizeof(symtab[i][0]); j++) { - symtab[i][j].st_name = elf32_to_cpu(symtab[i][j].st_name); - symtab[i][j].st_value = elf32_to_cpu(symtab[i][j].st_value); - symtab[i][j].st_size = elf32_to_cpu(symtab[i][j].st_size); - symtab[i][j].st_shndx = elf16_to_cpu(symtab[i][j].st_shndx); - } - } -} - - -static void read_relocs(FILE *fp) -{ - int i,j; - for(i = 0; i < ehdr.e_shnum; i++) { - if (shdr[i].sh_type != SHT_REL) { - continue; - } - reltab[i] = malloc(shdr[i].sh_size); - if (!reltab[i]) { - die("malloc of %d bytes for relocs failed\n", - shdr[i].sh_size); - } - if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { - die("Seek to %d failed: %s\n", - shdr[i].sh_offset, strerror(errno)); - } - if (fread(reltab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) { - die("Cannot read symbol table: %s\n", - strerror(errno)); - } - for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { - reltab[i][j].r_offset = elf32_to_cpu(reltab[i][j].r_offset); - reltab[i][j].r_info = elf32_to_cpu(reltab[i][j].r_info); - } - } -} - - -static void print_absolute_symbols(void) -{ - int i; - printf("Absolute symbols\n"); - printf(" Num: Value Size Type Bind Visibility Name\n"); - for(i = 0; i < ehdr.e_shnum; i++) { - char *sym_strtab; - Elf32_Sym *sh_symtab; - int j; - if (shdr[i].sh_type != SHT_SYMTAB) { - continue; - } - sh_symtab = symtab[i]; - sym_strtab = strtab[shdr[i].sh_link]; - for(j = 0; j < shdr[i].sh_size/sizeof(symtab[0][0]); j++) { - Elf32_Sym *sym; - const char *name; - sym = &symtab[i][j]; - name = sym_name(sym_strtab, sym); - if (sym->st_shndx != SHN_ABS) { - continue; - } - printf("%5d %08x %5d %10s %10s %12s %s\n", - j, sym->st_value, sym->st_size, - sym_type(ELF32_ST_TYPE(sym->st_info)), - sym_bind(ELF32_ST_BIND(sym->st_info)), - sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)), - name); - } - } - printf("\n"); -} - -static void print_absolute_relocs(void) -{ - int i, printed = 0; - - for(i = 0; i < ehdr.e_shnum; i++) { - char *sym_strtab; - Elf32_Sym *sh_symtab; - unsigned sec_applies, sec_symtab; - int j; - if (shdr[i].sh_type != SHT_REL) { - continue; - } - sec_symtab = shdr[i].sh_link; - sec_applies = shdr[i].sh_info; - if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) { - continue; - } - sh_symtab = symtab[sec_symtab]; - sym_strtab = strtab[shdr[sec_symtab].sh_link]; - for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { - Elf32_Rel *rel; - Elf32_Sym *sym; - const char *name; - rel = &reltab[i][j]; - sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; - name = sym_name(sym_strtab, sym); - if (sym->st_shndx != SHN_ABS) { - continue; - } - - /* Absolute symbols are not relocated if bzImage is - * loaded at a non-compiled address. Display a warning - * to user at compile time about the absolute - * relocations present. - * - * User need to audit the code to make sure - * some symbols which should have been section - * relative have not become absolute because of some - * linker optimization or wrong programming usage. - * - * Before warning check if this absolute symbol - * relocation is harmless. - */ - if (is_safe_abs_reloc(name)) - continue; - - if (!printed) { - printf("WARNING: Absolute relocations" - " present\n"); - printf("Offset Info Type Sym.Value " - "Sym.Name\n"); - printed = 1; - } - - printf("%08x %08x %10s %08x %s\n", - rel->r_offset, - rel->r_info, - rel_type(ELF32_R_TYPE(rel->r_info)), - sym->st_value, - name); - } - } - - if (printed) - printf("\n"); -} - -static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) -{ - int i; - /* Walk through the relocations */ - for(i = 0; i < ehdr.e_shnum; i++) { - char *sym_strtab; - Elf32_Sym *sh_symtab; - unsigned sec_applies, sec_symtab; - int j; - if (shdr[i].sh_type != SHT_REL) { - continue; - } - sec_symtab = shdr[i].sh_link; - sec_applies = shdr[i].sh_info; - if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) { - continue; - } - sh_symtab = symtab[sec_symtab]; - sym_strtab = strtab[shdr[sec_symtab].sh_link]; - for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { - Elf32_Rel *rel; - Elf32_Sym *sym; - unsigned r_type; - rel = &reltab[i][j]; - sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; - r_type = ELF32_R_TYPE(rel->r_info); - /* Don't visit relocations to absolute symbols */ - if (sym->st_shndx == SHN_ABS) { - continue; - } - if (r_type == R_386_PC32) { - /* PC relative relocations don't need to be adjusted */ - } - else if (r_type == R_386_32) { - /* Visit relocations that need to be adjusted */ - visit(rel, sym); - } - else { - die("Unsupported relocation type: %d\n", r_type); - } - } - } -} - -static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym) -{ - reloc_count += 1; -} - -static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym) -{ - /* Remember the address that needs to be adjusted. */ - relocs[reloc_idx++] = rel->r_offset; -} - -static int cmp_relocs(const void *va, const void *vb) -{ - const unsigned long *a, *b; - a = va; b = vb; - return (*a == *b)? 0 : (*a > *b)? 1 : -1; -} - -static void emit_relocs(int as_text) -{ - int i; - /* Count how many relocations I have and allocate space for them. */ - reloc_count = 0; - walk_relocs(count_reloc); - relocs = malloc(reloc_count * sizeof(relocs[0])); - if (!relocs) { - die("malloc of %d entries for relocs failed\n", - reloc_count); - } - /* Collect up the relocations */ - reloc_idx = 0; - walk_relocs(collect_reloc); - - /* Order the relocations for more efficient processing */ - qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs); - - /* 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"); - for(i = 0; i < reloc_count; i++) { - printf("\t .long 0x%08lx\n", relocs[i]); - } - printf("\n"); - } - else { - unsigned char buf[4]; - buf[0] = buf[1] = buf[2] = buf[3] = 0; - /* Print a stop */ - printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]); - /* Now print each relocation */ - for(i = 0; i < reloc_count; i++) { - buf[0] = (relocs[i] >> 0) & 0xff; - buf[1] = (relocs[i] >> 8) & 0xff; - buf[2] = (relocs[i] >> 16) & 0xff; - buf[3] = (relocs[i] >> 24) & 0xff; - printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]); - } - } -} - -static void usage(void) -{ - die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n"); -} - -int main(int argc, char **argv) -{ - int show_absolute_syms, show_absolute_relocs; - int as_text; - const char *fname; - FILE *fp; - int i; - - show_absolute_syms = 0; - show_absolute_relocs = 0; - as_text = 0; - fname = NULL; - for(i = 1; i < argc; i++) { - char *arg = argv[i]; - if (*arg == '-') { - if (strcmp(argv[1], "--abs-syms") == 0) { - show_absolute_syms = 1; - continue; - } - - if (strcmp(argv[1], "--abs-relocs") == 0) { - show_absolute_relocs = 1; - continue; - } - else if (strcmp(argv[1], "--text") == 0) { - as_text = 1; - continue; - } - } - else if (!fname) { - fname = arg; - continue; - } - usage(); - } - if (!fname) { - usage(); - } - fp = fopen(fname, "r"); - if (!fp) { - die("Cannot open %s: %s\n", - fname, strerror(errno)); - } - read_ehdr(fp); - read_shdrs(fp); - read_strtabs(fp); - read_symtabs(fp); - read_relocs(fp); - if (show_absolute_syms) { - print_absolute_symbols(); - return 0; - } - if (show_absolute_relocs) { - print_absolute_relocs(); - return 0; - } - emit_relocs(as_text); - return 0; -} |
