diff options
Diffstat (limited to 'arch/x86/tools/relocs.c')
| -rw-r--r-- | arch/x86/tools/relocs.c | 673 |
1 files changed, 354 insertions, 319 deletions
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index f7bab68a4b83..e5a2b9a912d1 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* This is included from relocs_32/64.c */ #define ElfW(type) _ElfW(ELF_BITS, type) @@ -10,28 +11,46 @@ #define Elf_Shdr ElfW(Shdr) #define Elf_Sym ElfW(Sym) -static Elf_Ehdr ehdr; +static Elf_Ehdr ehdr; +static unsigned long shnum; +static unsigned int shstrndx; +static unsigned int shsymtabndx; +static unsigned int shxsymtabndx; + +static int sym_index(Elf_Sym *sym); struct relocs { - uint32_t *offset; - unsigned long count; - unsigned long size; + uint32_t *offset; + unsigned long count; + unsigned long size; }; -static struct relocs relocs16; -static struct relocs relocs32; -static struct relocs relocs64; +static struct relocs relocs16; +static struct relocs relocs32; + +#if ELF_BITS == 64 +static struct relocs relocs64; +# define FMT PRIu64 + +#ifndef R_X86_64_REX_GOTPCRELX +# define R_X86_64_REX_GOTPCRELX 42 +#endif + +#else +# define FMT PRIu32 +#endif struct section { - Elf_Shdr shdr; - struct section *link; - Elf_Sym *symtab; - Elf_Rel *reltab; - char *strtab; + Elf_Shdr shdr; + struct section *link; + Elf_Sym *symtab; + Elf32_Word *xsymtab; + Elf_Rel *reltab; + char *strtab; }; -static struct section *secs; +static struct section *secs; -static const char * const sym_regex_kernel[S_NSYMTYPES] = { +static const char * const sym_regex_kernel[S_NSYMTYPES] = { /* * Following symbols have been audited. There values are constant and do * not change if bzImage is loaded at a different physical address than @@ -41,7 +60,9 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = { [S_ABS] = "^(xen_irq_disable_direct_reloc$|" "xen_save_fl_direct_reloc$|" + "xen_elfnote_.+_offset$|" "VDSO|" + "__kcfi_typeid_|" "__crc_)", /* @@ -51,25 +72,25 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = { [S_REL] = "^(__init_(begin|end)|" "__x86_cpu_dev_(start|end)|" - "(__parainstructions|__alt_instructions)(|_end)|" - "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|" + "__alt_instructions(_end)?|" + "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|" "__(start|end)_pci_.*|" +#if CONFIG_FW_LOADER "__(start|end)_builtin_fw|" - "__(start|stop)___ksymtab(|_gpl|_unused|_unused_gpl|_gpl_future)|" - "__(start|stop)___kcrctab(|_gpl|_unused|_unused_gpl|_gpl_future)|" +#endif + "__(start|stop)___ksymtab(_gpl)?|" + "__(start|stop)___kcrctab(_gpl)?|" "__(start|stop)___param|" "__(start|stop)___modver|" "__(start|stop)___bug_table|" "__tracedata_(start|end)|" "__(start|stop)_notes|" "__end_rodata|" + "__end_rodata_aligned|" "__initramfs_start|" "(jiffies|jiffies_64)|" #if ELF_BITS == 64 - "__per_cpu_load|" - "init_per_cpu__.*|" "__end_rodata_hpage_align|" - "__vvar_page|" #endif "_end)$" }; @@ -97,13 +118,13 @@ static const char * const sym_regex_realmode[S_NSYMTYPES] = { "^pa_", }; -static const char * const *sym_regex; +static const char * const *sym_regex; + +static regex_t sym_regex_c[S_NSYMTYPES]; -static regex_t sym_regex_c[S_NSYMTYPES]; static int is_reloc(enum symtype type, const char *sym_name) { - return sym_regex[type] && - !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0); + return sym_regex[type] && !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0); } static void regex_init(int use_real_mode) @@ -121,11 +142,10 @@ static void regex_init(int use_real_mode) if (!sym_regex[i]) continue; - err = regcomp(&sym_regex_c[i], sym_regex[i], - REG_EXTENDED|REG_NOSUB); + err = regcomp(&sym_regex_c[i], sym_regex[i], REG_EXTENDED|REG_NOSUB); if (err) { - regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf); + regerror(err, &sym_regex_c[i], errbuf, sizeof(errbuf)); die("%s", errbuf); } } @@ -145,9 +165,10 @@ static const char *sym_type(unsigned type) #undef SYM_TYPE }; const char *name = "unknown sym type name"; - if (type < ARRAY_SIZE(type_name)) { + + if (type < ARRAY_SIZE(type_name)) name = type_name[type]; - } + return name; } @@ -161,9 +182,10 @@ static const char *sym_bind(unsigned bind) #undef SYM_BIND }; const char *name = "unknown sym bind name"; - if (bind < ARRAY_SIZE(bind_name)) { + + if (bind < ARRAY_SIZE(bind_name)) name = bind_name[bind]; - } + return name; } @@ -178,9 +200,10 @@ static const char *sym_visibility(unsigned visibility) #undef SYM_VISIBILITY }; const char *name = "unknown sym visibility name"; - if (visibility < ARRAY_SIZE(visibility_name)) { + + if (visibility < ARRAY_SIZE(visibility_name)) name = visibility_name[visibility]; - } + return name; } @@ -191,6 +214,7 @@ static const char *rel_type(unsigned type) #if ELF_BITS == 64 REL_TYPE(R_X86_64_NONE), REL_TYPE(R_X86_64_64), + REL_TYPE(R_X86_64_PC64), REL_TYPE(R_X86_64_PC32), REL_TYPE(R_X86_64_GOT32), REL_TYPE(R_X86_64_PLT32), @@ -205,6 +229,7 @@ static const char *rel_type(unsigned type) REL_TYPE(R_X86_64_PC16), REL_TYPE(R_X86_64_8), REL_TYPE(R_X86_64_PC8), + REL_TYPE(R_X86_64_REX_GOTPCRELX), #else REL_TYPE(R_386_NONE), REL_TYPE(R_386_32), @@ -225,9 +250,10 @@ static const char *rel_type(unsigned type) #undef REL_TYPE }; const char *name = "unknown type rel type name"; - if (type < ARRAY_SIZE(type_name) && type_name[type]) { + + if (type < ARRAY_SIZE(type_name) && type_name[type]) name = type_name[type]; - } + return name; } @@ -235,17 +261,16 @@ static const char *sec_name(unsigned shndx) { const char *sec_strtab; const char *name; - sec_strtab = secs[ehdr.e_shstrndx].strtab; + sec_strtab = secs[shstrndx].strtab; name = "<noname>"; - if (shndx < ehdr.e_shnum) { + + if (shndx < shnum) name = sec_strtab + secs[shndx].shdr.sh_name; - } - else if (shndx == SHN_ABS) { + else if (shndx == SHN_ABS) name = "ABSOLUTE"; - } - else if (shndx == SHN_COMMON) { + else if (shndx == SHN_COMMON) name = "COMMON"; - } + return name; } @@ -253,51 +278,25 @@ static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) { const char *name; name = "<noname>"; - if (sym->st_name) { - name = sym_strtab + sym->st_name; - } - else { - name = sec_name(sym->st_shndx); - } - return name; -} - -static Elf_Sym *sym_lookup(const char *symname) -{ - int i; - for (i = 0; i < ehdr.e_shnum; i++) { - struct section *sec = &secs[i]; - long nsyms; - char *strtab; - Elf_Sym *symtab; - Elf_Sym *sym; - if (sec->shdr.sh_type != SHT_SYMTAB) - continue; - - nsyms = sec->shdr.sh_size/sizeof(Elf_Sym); - symtab = sec->symtab; - strtab = sec->link->strtab; + if (sym->st_name) + name = sym_strtab + sym->st_name; + else + name = sec_name(sym_index(sym)); - for (sym = symtab; --nsyms >= 0; sym++) { - if (!sym->st_name) - continue; - if (strcmp(symname, strtab + sym->st_name) == 0) - return sym; - } - } - return 0; + 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 le16_to_cpu(val) (val) +# define le32_to_cpu(val) (val) +# define le64_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) -#define le64_to_cpu(val) bswap_64(val) +# define le16_to_cpu(val) bswap_16(val) +# define le32_to_cpu(val) bswap_32(val) +# define le64_to_cpu(val) bswap_64(val) #endif static uint16_t elf16_to_cpu(uint16_t val) @@ -318,33 +317,45 @@ static uint64_t elf64_to_cpu(uint64_t val) { return le64_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) +# 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) +# 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 int sym_index(Elf_Sym *sym) +{ + Elf_Sym *symtab = secs[shsymtabndx].symtab; + Elf32_Word *xsymtab = secs[shxsymtabndx].xsymtab; + unsigned long offset; + int index; + + if (sym->st_shndx != SHN_XINDEX) + return sym->st_shndx; + + /* calculate offset of sym from head of table. */ + offset = (unsigned long)sym - (unsigned long)symtab; + index = offset / sizeof(*sym); + + return elf32_to_cpu(xsymtab[index]); +} + 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) { + 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) { + if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) die("Not a %d bit executable\n", ELF_BITS); - } - if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { + if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) die("Not a LSB ELF executable\n"); - } - if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) { + 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); @@ -360,27 +371,41 @@ static void read_ehdr(FILE *fp) 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)) { + shnum = ehdr.e_shnum; + shstrndx = 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) { + if (ehdr.e_machine != ELF_MACHINE) die("Not for %s\n", ELF_MACHINE_NAME); - } - if (ehdr.e_version != EV_CURRENT) { + 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)) { + 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)) { + if (ehdr.e_shentsize != sizeof(Elf_Shdr)) die("Bad section header entry\n"); + + + if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) { + Elf_Shdr shdr; + + if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) + die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno)); + + if (fread(&shdr, sizeof(shdr), 1, fp) != 1) + die("Cannot read initial ELF section header: %s\n", strerror(errno)); + + if (shnum == SHN_UNDEF) + shnum = elf_xword_to_cpu(shdr.sh_size); + + if (shstrndx == SHN_XINDEX) + shstrndx = elf_word_to_cpu(shdr.sh_link); } - if (ehdr.e_shstrndx >= ehdr.e_shnum) { + + if (shstrndx >= shnum) die("String table index out of bounds\n"); - } } static void read_shdrs(FILE *fp) @@ -388,20 +413,19 @@ 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++) { + secs = calloc(shnum, sizeof(struct section)); + if (!secs) + die("Unable to allocate %ld section headers\n", shnum); + + if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) + die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno)); + + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; - if (fread(&shdr, sizeof shdr, 1, fp) != 1) - die("Cannot read ELF section headers %d/%d: %s\n", - i, ehdr.e_shnum, strerror(errno)); + + if (fread(&shdr, sizeof(shdr), 1, fp) != 1) + die("Cannot read ELF section headers %d/%ld: %s\n", i, 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); @@ -412,7 +436,7 @@ static void read_shdrs(FILE *fp) 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) + if (sec->shdr.sh_link < shnum) sec->link = &secs[sec->shdr.sh_link]; } @@ -421,56 +445,74 @@ static void read_shdrs(FILE *fp) static void read_strtabs(FILE *fp) { int i; - for (i = 0; i < ehdr.e_shnum; i++) { + + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; - if (sec->shdr.sh_type != SHT_STRTAB) { + + 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)); - } + if (!sec->strtab) + die("malloc of %" FMT " bytes for strtab failed\n", sec->shdr.sh_size); + + if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) + die("Seek to %" FMT " 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++) { + int i, j; + + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; - if (sec->shdr.sh_type != SHT_SYMTAB) { + int num_syms; + + switch (sec->shdr.sh_type) { + case SHT_SYMTAB_SHNDX: + sec->xsymtab = malloc(sec->shdr.sh_size); + if (!sec->xsymtab) + die("malloc of %" FMT " bytes for xsymtab failed\n", sec->shdr.sh_size); + + if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) + die("Seek to %" FMT " failed: %s\n", sec->shdr.sh_offset, strerror(errno)); + + if (fread(sec->xsymtab, 1, sec->shdr.sh_size, fp) != sec->shdr.sh_size) + die("Cannot read extended symbol table: %s\n", strerror(errno)); + + shxsymtabndx = i; + continue; + + case SHT_SYMTAB: + num_syms = sec->shdr.sh_size / sizeof(Elf_Sym); + + sec->symtab = malloc(sec->shdr.sh_size); + if (!sec->symtab) + die("malloc of %" FMT " bytes for symtab failed\n", sec->shdr.sh_size); + + if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) + die("Seek to %" FMT " 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 < num_syms; 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); + } + shsymtabndx = i; + continue; + + default: 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); } } } @@ -478,28 +520,27 @@ static void read_symtabs(FILE *fp) static void read_relocs(FILE *fp) { - int i,j; - for (i = 0; i < ehdr.e_shnum; i++) { + int i, j; + + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; - if (sec->shdr.sh_type != SHT_REL_TYPE) { + + 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)); - } + if (!sec->reltab) + die("malloc of %" FMT " bytes for relocs failed\n", sec->shdr.sh_size); + + if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) + die("Seek to %" FMT " 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); rel->r_info = elf_xword_to_cpu(rel->r_info); #if (SHT_REL_TYPE == SHT_RELA) @@ -522,23 +563,27 @@ static void print_absolute_symbols(void) printf("Absolute symbols\n"); printf(" Num: Value Size Type Bind Visibility Name\n"); - for (i = 0; i < ehdr.e_shnum; i++) { + + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; char *sym_strtab; int j; - if (sec->shdr.sh_type != SHT_SYMTAB) { + if (sec->shdr.sh_type != SHT_SYMTAB) continue; - } + sym_strtab = sec->link->strtab; + for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) { Elf_Sym *sym; const char *name; + sym = &sec->symtab[j]; name = sym_name(sym_strtab, sym); - if (sym->st_shndx != SHN_ABS) { + + if (sym->st_shndx != SHN_ABS) continue; - } + printf(format, j, sym->st_value, sym->st_size, sym_type(ELF_ST_TYPE(sym->st_info)), @@ -560,32 +605,43 @@ static void print_absolute_relocs(void) else format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32" %s\n"; - for (i = 0; i < ehdr.e_shnum; i++) { + for (i = 0; i < shnum; i++) { struct section *sec = &secs[i]; struct section *sec_applies, *sec_symtab; char *sym_strtab; Elf_Sym *sh_symtab; int j; - if (sec->shdr.sh_type != SHT_REL_TYPE) { + + 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)) { + if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) continue; - } + + /* + * Do not perform relocations in .notes section; any + * values there are meant for pre-boot consumption (e.g. + * startup_xen). + */ + if (sec_applies->shdr.sh_type == SHT_NOTE) + 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; Elf_Sym *sym; const char *name; + rel = &sec->reltab[j]; sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; name = sym_name(sym_strtab, sym); - if (sym->st_shndx != SHN_ABS) { + + if (sym->st_shndx != SHN_ABS) continue; - } /* Absolute symbols are not relocated if bzImage is * loaded at a non-compiled address. Display a warning @@ -604,10 +660,8 @@ static void print_absolute_relocs(void) continue; if (!printed) { - printf("WARNING: Absolute relocations" - " present\n"); - printf("Offset Info Type Sym.Value " - "Sym.Name\n"); + printf("WARNING: Absolute relocations present\n"); + printf("Offset Info Type Sym.Value Sym.Name\n"); printed = 1; } @@ -631,8 +685,8 @@ static void add_reloc(struct relocs *r, uint32_t offset) void *mem = realloc(r->offset, newsize * sizeof(r->offset[0])); if (!mem) - die("realloc of %ld entries for relocs failed\n", - newsize); + die("realloc of %ld entries for relocs failed\n", newsize); + r->offset = mem; r->size = newsize; } @@ -643,24 +697,34 @@ 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++) { + for (i = 0; i < 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) { + 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)) { + if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) continue; - } + + /* + * Do not perform relocations in .notes sections; any + * values there are meant for pre-boot consumption (e.g. + * startup_xen). + */ + if (sec_applies->shdr.sh_type == SHT_NOTE) + 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)]; @@ -671,69 +735,8 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, } } -/* - * The .data..percpu section is a special case for x86_64 SMP kernels. - * It is used to initialize the actual per_cpu areas and to provide - * definitions for the per_cpu variables that correspond to their offsets - * within the percpu area. Since the values of all of the symbols need - * to be offsets from the start of the per_cpu area the virtual address - * (sh_addr) of .data..percpu is 0 in SMP kernels. - * - * This means that: - * - * Relocations that reference symbols in the per_cpu area do not - * need further relocation (since the value is an offset relative - * to the start of the per_cpu area that does not change). - * - * Relocations that apply to the per_cpu area need to have their - * offset adjusted by by the value of __per_cpu_load to make them - * point to the correct place in the loaded image (because the - * virtual address of .data..percpu is 0). - * - * For non SMP kernels .data..percpu is linked as part of the normal - * kernel data and does not require special treatment. - * - */ -static int per_cpu_shndx = -1; -Elf_Addr per_cpu_load_addr; - -static void percpu_init(void) -{ - int i; - for (i = 0; i < ehdr.e_shnum; i++) { - ElfW(Sym) *sym; - if (strcmp(sec_name(i), ".data..percpu")) - continue; - - if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */ - return; - - sym = sym_lookup("__per_cpu_load"); - if (!sym) - die("can't find __per_cpu_load\n"); - - per_cpu_shndx = i; - per_cpu_load_addr = sym->st_value; - return; - } -} - #if ELF_BITS == 64 -/* - * Check to see if a symbol lies in the .data..percpu section. - * For some as yet not understood reason the "__init_begin" - * symbol which immediately preceeds the .data..percpu section - * also shows up as it it were part of it so we do an explict - * check for that symbol name and ignore it. - */ -static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) -{ - return (sym->st_shndx == per_cpu_shndx) && - strcmp(symname, "__init_begin"); -} - - static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, const char *symname) { @@ -744,30 +747,30 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, if (sym->st_shndx == SHN_UNDEF) return 0; - /* - * Adjust the offset if this reloc applies to the percpu section. - */ - if (sec->shdr.sh_info == per_cpu_shndx) - offset += per_cpu_load_addr; - switch (r_type) { case R_X86_64_NONE: + /* NONE can be ignored. */ + break; + case R_X86_64_PC32: + case R_X86_64_PLT32: + case R_X86_64_REX_GOTPCRELX: /* - * NONE can be ignored and PC relative relocations don't - * need to be adjusted. + * PC relative relocations don't need to be adjusted. + * + * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32. */ break; - case R_X86_64_32: - case R_X86_64_32S: - case R_X86_64_64: + case R_X86_64_PC64: /* - * References to the percpu area don't need to be adjusted. + * Only used by jump labels */ - if (is_percpu_sym(sym, symname)) - break; + break; + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_64: if (shn_abs) { /* * Whitelisted absolute symbols do not require @@ -776,8 +779,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, if (is_reloc(S_ABS, symname)) break; - die("Invalid absolute %s relocation: %s\n", - rel_type(r_type), symname); + die("Invalid absolute %s relocation: %s\n", rel_type(r_type), symname); break; } @@ -797,8 +799,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, break; default: - die("Unsupported relocation type: %s (%d)\n", - rel_type(r_type), r_type); + die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type); break; } @@ -818,9 +819,11 @@ static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, case R_386_PC32: case R_386_PC16: case R_386_PC8: + case R_386_PLT32: /* - * NONE can be ignored and PC relative relocations don't - * need to be adjusted. + * NONE can be ignored and PC relative relocations don't need + * to be adjusted. Because sym must be defined, R_386_PLT32 can + * be treated the same way as R_386_PC32. */ break; @@ -833,8 +836,7 @@ static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, if (is_reloc(S_ABS, symname)) break; - die("Invalid absolute %s relocation: %s\n", - rel_type(r_type), symname); + die("Invalid absolute %s relocation: %s\n", rel_type(r_type), symname); break; } @@ -842,16 +844,14 @@ static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, break; default: - die("Unsupported relocation type: %s (%d)\n", - rel_type(r_type), r_type); + die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type); break; } return 0; } -static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, - const char *symname) +static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname) { unsigned r_type = ELF32_R_TYPE(rel->r_info); int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); @@ -861,9 +861,11 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, case R_386_PC32: case R_386_PC16: case R_386_PC8: + case R_386_PLT32: /* - * NONE can be ignored and PC relative relocations don't - * need to be adjusted. + * NONE can be ignored and PC relative relocations don't need + * to be adjusted. Because sym must be defined, R_386_PLT32 can + * be treated the same way as R_386_PC32. */ break; @@ -884,9 +886,7 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, if (!is_reloc(S_LIN, symname)) break; } - die("Invalid %s %s relocation: %s\n", - shn_abs ? "absolute" : "relative", - rel_type(r_type), symname); + die("Invalid %s %s relocation: %s\n", shn_abs ? "absolute" : "relative", rel_type(r_type), symname); break; case R_386_32: @@ -907,14 +907,11 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, add_reloc(&relocs32, rel->r_offset); break; } - die("Invalid %s %s relocation: %s\n", - shn_abs ? "absolute" : "relative", - rel_type(r_type), symname); + die("Invalid %s %s relocation: %s\n", shn_abs ? "absolute" : "relative", rel_type(r_type), symname); break; default: - die("Unsupported relocation type: %s (%d)\n", - rel_type(r_type), r_type); + die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type); break; } @@ -926,13 +923,17 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, static int cmp_relocs(const void *va, const void *vb) { const uint32_t *a, *b; - a = va; b = vb; + + a = va; + b = vb; + return (*a == *b)? 0 : (*a > *b)? 1 : -1; } static void sort_relocs(struct relocs *r) { - qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); + if (r->count) + qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); } static int write32(uint32_t v, FILE *f) @@ -940,6 +941,7 @@ static int write32(uint32_t v, FILE *f) unsigned char buf[4]; put_unaligned_le32(v, buf); + return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; } @@ -952,8 +954,7 @@ static void emit_relocs(int as_text, int use_real_mode) { int i; int (*write_reloc)(uint32_t, FILE *) = write32; - int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, - const char *symname); + int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname); #if ELF_BITS == 64 if (!use_real_mode) @@ -974,9 +975,12 @@ static void emit_relocs(int as_text, int use_real_mode) die("Segment relocations found but --realmode not specified\n"); /* Order the relocations for more efficient processing */ - sort_relocs(&relocs16); sort_relocs(&relocs32); +#if ELF_BITS == 64 sort_relocs(&relocs64); +#else + sort_relocs(&relocs16); +#endif /* Print the relocations */ if (as_text) { @@ -997,14 +1001,14 @@ static void emit_relocs(int as_text, int use_real_mode) for (i = 0; i < relocs32.count; i++) write_reloc(relocs32.offset[i], stdout); } else { - if (ELF_BITS == 64) { - /* Print a stop */ - write_reloc(0, stdout); +#if ELF_BITS == 64 + /* Print a stop */ + write_reloc(0, stdout); - /* Now print each relocation */ - for (i = 0; i < relocs64.count; i++) - write_reloc(relocs64.offset[i], stdout); - } + /* Now print each relocation */ + for (i = 0; i < relocs64.count; i++) + write_reloc(relocs64.offset[i], stdout); +#endif /* Print a stop */ write_reloc(0, stdout); @@ -1015,6 +1019,30 @@ static void emit_relocs(int as_text, int use_real_mode) } } +/* + * 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("%s\t%s\t%s\t%s\n", + sec_name(sec->shdr.sh_info), + rel_type(ELF_R_TYPE(rel->r_info)), + symname, + sec_name(sym_index(sym))); + + return 0; +} + +static void print_reloc_info(void) +{ + printf("reloc section\treloc type\tsymbol\tsymbol section\n"); + walk_relocs(do_reloc_info); +} + #if ELF_BITS == 64 # define process process_64 #else @@ -1022,7 +1050,8 @@ static void emit_relocs(int as_text, int use_real_mode) #endif void process(FILE *fp, int use_real_mode, int as_text, - int show_absolute_syms, int show_absolute_relocs) + int show_absolute_syms, int show_absolute_relocs, + int show_reloc_info) { regex_init(use_real_mode); read_ehdr(fp); @@ -1030,15 +1059,21 @@ void process(FILE *fp, int use_real_mode, int as_text, read_strtabs(fp); read_symtabs(fp); read_relocs(fp); - if (ELF_BITS == 64) - percpu_init(); + if (show_absolute_syms) { print_absolute_symbols(); return; } + if (show_absolute_relocs) { print_absolute_relocs(); return; } + + if (show_reloc_info) { + print_reloc_info(); + return; + } + emit_relocs(as_text, use_real_mode); } |
