commit: a66ab9b88abf14b353a0720791e055bd901d1c6f Author: Anthony G. Basile <blueness <AT> gentoo <DOT> org> AuthorDate: Sat Jan 3 23:20:03 2015 +0000 Commit: Anthony G. Basile <blueness <AT> gentoo <DOT> org> CommitDate: Sat Jan 3 23:20:03 2015 +0000 URL: http://sources.gentoo.org/gitweb/?p=proj/elfix.git;a=commit;h=a66ab9b8
misc/elf-abi: read arch:abi:endian from an ELF, bug #534206 --- misc/elf-abi/.gitignore | 2 + misc/elf-abi/Makefile | 18 +++ misc/elf-abi/elf-abi.c | 314 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 334 insertions(+) diff --git a/misc/elf-abi/.gitignore b/misc/elf-abi/.gitignore new file mode 100644 index 0000000..7ec9e50 --- /dev/null +++ b/misc/elf-abi/.gitignore @@ -0,0 +1,2 @@ +elf-abi +!Makefile diff --git a/misc/elf-abi/Makefile b/misc/elf-abi/Makefile new file mode 100644 index 0000000..8a75d55 --- /dev/null +++ b/misc/elf-abi/Makefile @@ -0,0 +1,18 @@ +CFLAGS ?= -O2 -pipe -g +CFLAGS += -Wall +PWD = $$(pwd) + +all: elf-abi + +elf-abi: elf-abi.c + $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) -o $@ $< $(LDLIBS) + +PREFIX = /usr +BINDIR = $(PREFIX)/bin +install: elf-abi + install -m 755 -D elf-abi $(DESTDIR)$(BINDIR)/$< + +clean: + rm -f *.o *~ elf-abi + +.PHONY: all clean install diff --git a/misc/elf-abi/elf-abi.c b/misc/elf-abi/elf-abi.c new file mode 100644 index 0000000..589d458 --- /dev/null +++ b/misc/elf-abi/elf-abi.c @@ -0,0 +1,314 @@ +/* Copyright 2015 Gentoo Foundation + * Distributed under the terms of the GNU General Public License v2 + * + * Compute a multilib ABI identifier, as discussed here: + * + * https://bugs.gentoo.org/show_bug.cgi?id=534206 + * + * Supported identifiers: + * + * alpha_32 + * arm_{oabi32,32,64} + * hppa_32,64 + * ia_64 + * m68k_32 + * mips_{n32,n64,o32} + * ppc_{32,64} + * s390_32 + * sh_32 + * sparc_{32,64} + * x86_{32,x32,64} + * + * NOTES: + * + * * The ABIs referenced by some of the above *_32 and *_64 identifiers + * may be imaginary, but they are listed anyway, since the goal is to + * establish a naming convention that is as consistent and uniform as + * possible. + * + * * The Elf header's e_ident[EI_OSABI] byte is completely ignored, + * since OS-independence is one of the goals. The assumption is that, + * for given installation, we are only interested in tracking multilib + * ABIs for a single OS. + * + * REFERENCE: + * + * http://www.sco.com/developers/gabi/2000-07-17/ch4.eheader.html + * + * + * Copyright 2015 Anthony G. Basile - <bluen...@gentoo.org> + * Copyright 2015 Zac Medico - <zmed...@gentoo.org> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <err.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <fcntl.h> +#include <endian.h> + +/* We steal this from <elf.h> but don't include it so as to not increase our dependancies. */ +#define ELFMAG "\177ELF" + +#define ELFCLASS32 1 /* 32-bit objects */ +#define ELFCLASS64 2 /* 64-bit objects */ +#define ELFDATA2LSB 1 /* 2's complement, little endian */ +#define ELFDATA2MSB 2 /* 2's complement, big endian */ + +#define EM_SPARC 2 /* SUN SPARC */ +#define EM_386 3 /* Intel 80386 */ +#define EM_68K 4 /* Motorola m68k family */ +#define EM_MIPS 8 /* MIPS R3000 big-endian */ +#define EM_MIPS_RS3_LE 10 /* MIPS R3000 little-endian */ +#define EM_PARISC 15 /* HPPA */ +#define EM_SPARC32PLUS 18 /* Sun's "v8plus" */ +#define EM_PPC 20 /* PowerPC */ +#define EM_PPC64 21 /* PowerPC 64-bit */ +#define EM_S390 22 /* IBM S390 */ +#define EM_ARM 40 /* ARM */ +#define EM_FAKE_ALPHA 41 /* Digital Alpha */ +#define EM_SH 42 /* Hitachi SH */ +#define EM_SPARCV9 43 /* SPARC v9 64-bit */ +#define EM_IA_64 50 /* Intel Merced */ +#define EM_X86_64 62 /* AMD x86-64 architecture */ +#define EM_AARCH64 183 /* ARM AARCH64 */ +#define EM_ALPHA 0x9026 + +#define EF_MIPS_ABI2 32 +#define EF_MIPS_ABI_ON32 64 +/* +E_MIPS_ABI_O32 = 0x00001000 +E_MIPS_ABI_O64 = 0x00002000 +E_MIPS_ABI_EABI32 = 0x00003000 +E_MIPS_ABI_EABI64 = 0x00004000 +*/ + +#define EF_ARM_NEW_ABI 0x80 +#define EF_ARM_OLD_ABI 0x100 + + +/* +def compute_suffix_mips(elf_header): + name = None + mips_abi = elf_header.e_flags & EF_MIPS_ABI + if mips_abi: + if mips_abi == E_MIPS_ABI_O32: + name = "o32" + elif mips_abi == E_MIPS_ABI_O64: + name = "o64" + elif mips_abi == E_MIPS_ABI_EABI32: + name = "eabi32" + elif mips_abi == E_MIPS_ABI_EABI64: + name = "eabi64" + + elif elf_header.e_flags & EF_MIPS_ABI2: + name = "n32" + elif elf_header.ei_class == ELFCLASS64: + name = "n64" + + return name + +def compute_multilib_id(elf_header): + prefix = machine_prefix_map.get(elf_header.e_machine) + suffix = None + + if prefix == "mips": + suffix = compute_suffix_mips(elf_header) + elif elf_header.ei_class == ELFCLASS64: + suffix = "64" + elif elf_header.ei_class == ELFCLASS32: + if elf_header.e_machine == EM_X86_64: + suffix = "x32" + else: + suffix = "32" + + if prefix is None or suffix is None: + multilib_id = None + else: + multilib_id = "%s_%s" % (prefix, suffix) + + return multilib_id +*/ + + +#define bswap_16(x) ((uint16_t)((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))) + +/* +#define bswap_32(x) \ + ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \ + (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24)) +*/ + +#define MAX_IDENT 32 + +int +main(int argc, char* argv[]) +{ + char ident[MAX_IDENT]; /* The Gentoo standard arch_abi identifier. */ + char *arch; /* The Gentoo architecture identifier. */ + int fd; + struct stat s; + char magic[4]; /* magic number at the begining of the file */ + uint8_t ei_class, width; /* width = 8 bytes for 32-bits, 16 bytes for 64-bits. */ + uint8_t ei_data, endian; /* endian = 0 for little, 1 for big endian. */ + uint16_t e_machine; /* Size is Elf32_Half or Elf64_Half. Both are 2 bytes. */ + uint32_t e_flags; /* Size is Elf32_Word or Elf64_Word. Both are 4 bytes. */ + uint64_t e_flags_offset; /* Wide enough for either 32 or 64 bits. */ + + /* Is the second parameter a regular file? */ + if (argc != 2) + errx(1, "Usage: %s <file>", argv[0]); + if (stat(argv[1], &s) == -1) + errx(1, "%s does not exist", argv[1]); + if (!S_ISREG(s.st_mode)) + errx(1, "%s is not a regular file", argv[1]); + + /* Can we read it and is it an ELF object? */ + if ((fd = open(argv[1], O_RDONLY)) == -1) + err(1, "failed to open %s", argv[1]); + if (read(fd, magic, 4) == -1) + err(1, "read() magic failed"); + if (strncmp(magic, ELFMAG, 4) != 0) + errx(1, "%s is not an ELF object", argv[1]); + + + /* 32 or 64 bits? */ + if (read(fd, &ei_class, 1) == -1) + err(1, "read() ei_class failed"); + switch (ei_class) { + case ELFCLASS32: + width = 4; + printf("32 bit\n"); + break; + case ELFCLASS64: + width = 8; + printf("64 bit\n"); + break; + default: + width = 0; + printf("Unknown bit\n"); + } + + /* Little or Big Endian */ + if (read(fd, &ei_data, 1) == -1) + err(1, "read() ei_data failed"); + switch (ei_data) { + case ELFDATA2LSB: + endian = 0; + printf("Little Endian\n"); + break; + case ELFDATA2MSB: + endian = 1; + printf("Big Endian\n"); + break; + default: + endian = -1; + printf("Unknown Endian\n"); + } + + /* seek to e_macine = 16 bytes (e_ident[])) + 2 bytes (e_type which is Elf32_Half/Elf64_Half) */ + if (lseek(fd, 18, SEEK_SET) == -1) + err(1, "lseek() e_machine failed"); + + /* What is the arch? */ + if (read(fd, &e_machine, 2) == -1) + err(1, "read() e_machine failed"); + //if (endian == 0) + // e_machine = bswap_16(e_machine); + printf("Machine =%d\n", e_machine); + + switch(e_machine) { + case EM_ALPHA: + case EM_FAKE_ALPHA: + arch = "alpha"; + break; + case EM_X86_64: + arch = "amd64"; + break; + case EM_ARM: + arch = "arm"; + break; + case EM_AARCH64: + arch = "arm64"; + break; + case EM_68K: + arch = "m68k"; + break; + case EM_MIPS_RS3_LE: + case EM_MIPS: + arch = "mips"; + break; + case EM_IA_64: + arch = "ia64"; + break; + case EM_PARISC: + arch = "hppa"; + break; + case EM_PPC: + arch = "ppc"; + break; + case EM_PPC64: + arch = "ppc64"; + break; + case EM_S390: + arch = "s390"; + break; + case EM_SH: + arch = "sh"; + break; + case EM_SPARC32PLUS: + case EM_SPARCV9: + case EM_SPARC: + arch = "sparc"; + break; + case EM_386: + arch = "x86"; + break; + default: + arch = "unknown"; + } + + printf("%s\n", arch); + + + /* + e_data_offset = + if (lseek(fd, 18, SEEK_SET) == -1) + err(1, "lseek() e_machine failed"); + if (read(fd, &e_flags, 2) == -1) + err(1, "read() e_machine failed"); + */ + + memset(ident, 0, MAX_IDENT); + + close(fd); + exit(EXIT_SUCCESS); +} + +/* + # E_ENTRY + 3 * sizeof(uintN) + e_flags_offset = E_ENTRY + 3 * width // 8 + f.seek(e_flags_offset) + e_flags = uint32(f.read(4)) + + return _elf_header(ei_class, ei_data, e_machine, e_flags) + + multilib_id = compute_multilib_id(elf_header) +*/
