Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756459Ab3DLUOe (ORCPT ); Fri, 12 Apr 2013 16:14:34 -0400 Received: from smtp.outflux.net ([198.145.64.163]:46723 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756048Ab3DLUO2 (ORCPT ); Fri, 12 Apr 2013 16:14:28 -0400 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: kernel-hardening@lists.openwall.com, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Jarkko Sakkinen , Matthew Garrett , Matt Fleming , Eric Northup , Dan Rosenberg , Julien Tinnes , Will Drewry , Kees Cook Subject: [PATCH 1/6] x86: relocs: generalize Elf structure names Date: Fri, 12 Apr 2013 13:13:42 -0700 Message-Id: <1365797627-20874-2-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1365797627-20874-1-git-send-email-keescook@chromium.org> References: <1365797627-20874-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12621 Lines: 366 In preparation for making the reloc tool operate on 64-bit relocations, generalize the structure names for easy recompilation via #defines. Based on work by Neill Clift and Michael Davidson. Signed-off-by: Kees Cook --- arch/x86/tools/relocs.c | 170 +++++++++++++++++++++++++++-------------------- 1 file changed, 99 insertions(+), 71 deletions(-) diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index 79d67bd..fd28ef7 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -12,20 +12,42 @@ #include #include +#define ElfW(type) _ElfW(ELF_BITS, type) +#define _ElfW(bits, type) __ElfW(bits, type) +#define __ElfW(bits, type) Elf##bits##_##type + +#define ELF_BITS 32 +#define ELF_MACHINE EM_386 +#define ELF_MACHINE_NAME "i386" +#define SHT_REL_TYPE SHT_REL + +#define ELF_CLASS ELFCLASS32 +#define ELF_R_SYM(val) ELF32_R_SYM(val) +#define ELF_R_TYPE(val) ELF32_R_TYPE(val) +#define ELF_ST_TYPE(o) ELF32_ST_TYPE(o) +#define ELF_ST_BIND(o) ELF32_ST_BIND(o) +#define ELF_ST_VISIBILITY(o) ELF32_ST_VISIBILITY(o) + +#define Elf_Rel ElfW(Rel) +#define Elf_Ehdr ElfW(Ehdr) +#define Elf_Phdr ElfW(Phdr) +#define Elf_Shdr ElfW(Shdr) +#define Elf_Sym ElfW(Sym) + static void die(char *fmt, ...); #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) -static Elf32_Ehdr ehdr; +static Elf_Ehdr ehdr; static unsigned long reloc_count, reloc_idx; static unsigned long *relocs; static unsigned long reloc16_count, reloc16_idx; static unsigned long *relocs16; struct section { - Elf32_Shdr shdr; + Elf_Shdr shdr; struct section *link; - Elf32_Sym *symtab; - Elf32_Rel *reltab; + Elf_Sym *symtab; + Elf_Rel *reltab; char *strtab; }; static struct section *secs; @@ -240,7 +262,7 @@ static const char *sec_name(unsigned shndx) return name; } -static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym) +static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) { const char *name; name = ""; @@ -274,6 +296,12 @@ static uint32_t elf32_to_cpu(uint32_t val) return le32_to_cpu(val); } +#define elf_half_to_cpu(x) elf16_to_cpu(x) +#define elf_word_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) + static void read_ehdr(FILE *fp) { if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) { @@ -283,8 +311,8 @@ static void read_ehdr(FILE *fp) if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 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_CLASS] != ELF_CLASS) { + die("Not a %d bit executable\n", ELF_BITS); } if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { die("Not a LSB ELF executable\n"); @@ -293,36 +321,36 @@ static void read_ehdr(FILE *fp) 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); + 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 != EM_386) { - die("Not for x86\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(Elf32_Ehdr)) { + if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) { die("Bad Elf header size\n"); } - if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) { + if (ehdr.e_phentsize != sizeof(Elf_Phdr)) { die("Bad program header entry\n"); } - if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) { + if (ehdr.e_shentsize != sizeof(Elf_Shdr)) { die("Bad section header entry\n"); } if (ehdr.e_shstrndx >= ehdr.e_shnum) { @@ -333,7 +361,7 @@ static void read_ehdr(FILE *fp) static void read_shdrs(FILE *fp) { int i; - Elf32_Shdr shdr; + Elf_Shdr shdr; secs = calloc(ehdr.e_shnum, sizeof(struct section)); if (!secs) { @@ -349,16 +377,16 @@ static void read_shdrs(FILE *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 = elf32_to_cpu(shdr.sh_name); - sec->shdr.sh_type = elf32_to_cpu(shdr.sh_type); - sec->shdr.sh_flags = elf32_to_cpu(shdr.sh_flags); - sec->shdr.sh_addr = elf32_to_cpu(shdr.sh_addr); - sec->shdr.sh_offset = elf32_to_cpu(shdr.sh_offset); - sec->shdr.sh_size = elf32_to_cpu(shdr.sh_size); - sec->shdr.sh_link = elf32_to_cpu(shdr.sh_link); - sec->shdr.sh_info = elf32_to_cpu(shdr.sh_info); - sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign); - sec->shdr.sh_entsize = elf32_to_cpu(shdr.sh_entsize); + 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]; } @@ -412,12 +440,12 @@ static void read_symtabs(FILE *fp) die("Cannot read symbol table: %s\n", strerror(errno)); } - for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) { - Elf32_Sym *sym = &sec->symtab[j]; - sym->st_name = elf32_to_cpu(sym->st_name); - sym->st_value = elf32_to_cpu(sym->st_value); - sym->st_size = elf32_to_cpu(sym->st_size); - sym->st_shndx = elf16_to_cpu(sym->st_shndx); + 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); } } } @@ -428,7 +456,7 @@ static void read_relocs(FILE *fp) int i,j; for (i = 0; i < ehdr.e_shnum; i++) { struct section *sec = &secs[i]; - if (sec->shdr.sh_type != SHT_REL) { + if (sec->shdr.sh_type != SHT_REL_TYPE) { continue; } sec->reltab = malloc(sec->shdr.sh_size); @@ -445,10 +473,10 @@ static void read_relocs(FILE *fp) die("Cannot read symbol table: %s\n", strerror(errno)); } - for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) { - Elf32_Rel *rel = &sec->reltab[j]; - rel->r_offset = elf32_to_cpu(rel->r_offset); - rel->r_info = elf32_to_cpu(rel->r_info); + 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); } } } @@ -468,8 +496,8 @@ static void print_absolute_symbols(void) continue; } sym_strtab = sec->link->strtab; - for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) { - Elf32_Sym *sym; + 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); @@ -478,9 +506,9 @@ static void print_absolute_symbols(void) } 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)), + sym_type(ELF_ST_TYPE(sym->st_info)), + sym_bind(ELF_ST_BIND(sym->st_info)), + sym_visibility(ELF_ST_VISIBILITY(sym->st_other)), name); } } @@ -495,9 +523,9 @@ static void print_absolute_relocs(void) struct section *sec = &secs[i]; struct section *sec_applies, *sec_symtab; char *sym_strtab; - Elf32_Sym *sh_symtab; + Elf_Sym *sh_symtab; int j; - if (sec->shdr.sh_type != SHT_REL) { + if (sec->shdr.sh_type != SHT_REL_TYPE) { continue; } sec_symtab = sec->link; @@ -507,12 +535,12 @@ static void print_absolute_relocs(void) } sh_symtab = sec_symtab->symtab; sym_strtab = sec_symtab->link->strtab; - for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) { - Elf32_Rel *rel; - Elf32_Sym *sym; + 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[ELF32_R_SYM(rel->r_info)]; + sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; name = sym_name(sym_strtab, sym); if (sym->st_shndx != SHN_ABS) { continue; @@ -545,7 +573,7 @@ static void print_absolute_relocs(void) printf("%08x %08x %10s %08x %s\n", rel->r_offset, rel->r_info, - rel_type(ELF32_R_TYPE(rel->r_info)), + rel_type(ELF_R_TYPE(rel->r_info)), sym->st_value, name); } @@ -555,19 +583,19 @@ static void print_absolute_relocs(void) printf("\n"); } -static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym), +static void walk_relocs(void (*visit)(Elf_Rel *rel, Elf_Sym *sym), int use_real_mode) { int i; /* Walk through the relocations */ for (i = 0; i < ehdr.e_shnum; i++) { char *sym_strtab; - Elf32_Sym *sh_symtab; + Elf_Sym *sh_symtab; struct section *sec_applies, *sec_symtab; int j; struct section *sec = &secs[i]; - if (sec->shdr.sh_type != SHT_REL) { + if (sec->shdr.sh_type != SHT_REL_TYPE) { continue; } sec_symtab = sec->link; @@ -577,16 +605,16 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym), } sh_symtab = sec_symtab->symtab; sym_strtab = sec_symtab->link->strtab; - for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) { - Elf32_Rel *rel; - Elf32_Sym *sym; + for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { + Elf_Rel *rel; + Elf_Sym *sym; unsigned r_type; const char *symname; int shn_abs; rel = &sec->reltab[j]; - sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; - r_type = ELF32_R_TYPE(rel->r_info); + sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; + r_type = ELF_R_TYPE(rel->r_info); shn_abs = sym->st_shndx == SHN_ABS; @@ -647,18 +675,18 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym), } } -static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym) +static void count_reloc(Elf_Rel *rel, Elf_Sym *sym) { - if (ELF32_R_TYPE(rel->r_info) == R_386_16) + if (ELF_R_TYPE(rel->r_info) == R_386_16) reloc16_count++; else reloc_count++; } -static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym) +static void collect_reloc(Elf_Rel *rel, Elf_Sym *sym) { /* Remember the address that needs to be adjusted. */ - if (ELF32_R_TYPE(rel->r_info) == R_386_16) + if (ELF_R_TYPE(rel->r_info) == R_386_16) relocs16[reloc16_idx++] = rel->r_offset; else relocs[reloc_idx++] = rel->r_offset; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/